Title of Invention	A METAL CATALYST PRODUCED BY LAYING A THIN FLAT SHEET AND A THIN CORRUGATED SHEET ON EACH OTHER
Abstract	The invention provide a metal catalyst in which the mounting strength in mounting a honeycomb core body to an outer tube is enhanced, the brazing range is 'shortened to reduce the brazing cost, and vibration-proofness is enhanced. Thin flat sheets 63. ..and thin corrugated sheets 64. ..are laid on each other, are wound into a rolled form, and the flat sheets 63' ..and the corrugated sheets 64. ..are brazed to each other to form a honeycomb core body 65 having a multiplicity of cancellous passages, the outside surfaces 65a. ..of the honeycomb core body 65 are covered by an outer tube 61, and they are brazed to each other to obtain a metal catalyst 30. In the metal catalyst, the range of brazing between the flat sheet 63. ..and the corrugated sheets 64. ..is set to be shorter than the range of brazing between the honeycomb core body 65 and the outer tube 61.

Title of Invention

A METAL CATALYST PRODUCED BY LAYING A THIN FLAT SHEET AND A THIN CORRUGATED SHEET ON EACH OTHER

Abstract

The invention provide a metal catalyst in which the mounting strength in mounting a honeycomb core body to an outer tube is enhanced, the brazing range is 'shortened to reduce the brazing cost, and vibration-proofness is enhanced. Thin flat sheets 63. ..and thin corrugated sheets 64. ..are laid on each other, are wound into a rolled form, and the flat sheets 63' ..and the corrugated sheets 64. ..are brazed to each other to form a honeycomb core body 65 having a multiplicity of cancellous passages, the outside surfaces 65a. ..of the honeycomb core body 65 are covered by an outer tube 61, and they are brazed to each other to obtain a metal catalyst 30. In the metal catalyst, the range of brazing between the flat sheet 63. ..and the corrugated sheets 64. ..is set to be shorter than the range of brazing between the honeycomb core body 65 and the outer tube 61.

Full Text	[Name of Document] Specification [Title of the Invention] METAL CATALYST [Technical Field] [0001] The present invention relates to an improvement in a brazing structure for a metal catalyst including a honeycomb core body having a flat sheet and a corrugated sheet laid on each other, and an outer tube covering the outside surface of the honeycomb core body. [Background Art] [0002] Conventionally, a metal catalyst has been proposed in which a flat sheet and a corrugated sheet are laid on each other and are brazed to each other to form a honeycomb core body, and the honeycomb core body and an outer tube are brazed to each other (see, for example, Patent Document 1). [Patent Document 1] Japanese Patent Laid-Open No. Hei 9-267044 (Fig. 1) [0003] Fig. 1 in Patent Document 1 shows vertical sectional views of a metal support for a catalyst device, in which Fig. 1(A) is a vertical sectional view containing the axis, and Fig. 1(B) is a schematic vertical sectional view showing the relationships between the members constituting Fig. 1(A). The metal support 10 (hereinafter referred to as the metal catalyst 10) (the symbols used in the patent document are used here) is composed of a honeycomb body 4 obtained by winding an alternately laid stack of a corrugated sheet member 1 and a flat sheet member 2 into a rolled form, with brazing materials 3a and 3b therebetween, and an outer tube 5 provided on the outer periphery of the honeycomb body 4, with a brazing material 3a therebetween. Then, the interposed brazing materials 3a and 3b are melted, to fuse the members to each other. The brazing materials 3a and 3b are disposed in a brazing region 3, in order to relax the thermal stresses generated in the honeycomb body 4. [0004] However, the length of brazing between the flat sheet member 2 and the corrugated sheet member 1 constituting the honeycomb body 4 is equal to the length of brazing between the honeycomb body 4 and the outer tube 5. Therefore, when the length of brazing between the flat sheet member 2 and the corrugated sheet member 1 is shortened, the length of brazing between the honeycomb body 4 and the outer tube 5 is also shortened, resulting in an insufficient mounting strength of the honeycomb body 4. [Disclosure of the Invention] [Problems to be Solved by the Invention] [0005] In recent years, attendant on enhancement of the performance such as output of motorcycles, there has been an increasing demand for enhancement of the mounting strength of a metal catalyst. On the other hand, a further reduction in cost is also expected. In view of this, it is an object of the present invention to provide a metal catalyst in which the mounting strength in mounting a honeycomb core body to an outer tube is enhanced, the range of brazing is shortened so as to reduce the brazing cost, and vibration-proofness is enhanced. [Means for Solving the Problems] [0006] The invention as set forth in claim 1 resides in a metal catalyst produced by laying a thin flat sheet and a thin corrugated sheet on each other, winding the laid-on sheets into a rolled form, brazing the flat sheet and the corrugated sheet to each other to form a honeycomb core body having a multiplicity of cancellous passages, covering the outside surface of the honeycomb core body with an outer tube, and brazing the honeycomb core body and the outer tube to each other, characterized in that the range of brazing between the flat sheet and the corrugated sheet is shorter than the range of brazing between the honeycomb core body and the outer tube. [0007] The invention as set forth in claim 2 is characterized in that the position of brazing between the flat sheet and the corrugated sheet is deviated to the outlet side with respect to a flow of an exhaust gas. [0008] The invention as set forth in claim 3 is characterized in that the length of brazing between the flat sheet and the corrugated sheet is 10 to 50% based on the length of the honeycomb core body. [0009] The invention as set forth in claim 4 is characterized in that a metal catalyst as set forth in claim 1, 2 or 3 is mounted to a separator partitioning the inside of a muffler in such a manner that the position of brazing between the flat sheet and the corrugated sheet overlaps with the separator. [Effects of the Invention] [0010] In the invention as set forth in claim 1, the range of brazing between the flat sheet and the corrugated sheet is set shorter than the range of brazing between the honeycomb core body and the outer tube, which makes it possible to reduce the amount of brazing between the flat sheet and the corrugated sheet and to reduce the cost and weight of the metal catalyst. In addition, the configuration in which the range of brazing between the flat sheet and the corrugated sheet is shorter than the range of brazing between the honeycomb core body and the outer tube means that the range of brazing between the honeycomb core body and the outer tube is set long. As a result, the mounting strength in mounting the honeycomb core body to the outer tube can be enhanced. [0011] Further, since the setting of the range of brazing between the flat sheet and the corrugated sheet to be short provides a reduction in thermal stress, it is easy to secure a predetermined strength between the flat sheet and the corrugated sheet. Since the mounting strength in mounting the honeycomb core body to the outer tube is enhanced while securing a predetermined strength between the flat sheet and the corrugated sheet, the vibration-proofness of the metal catalyst can be enhanced. Therefore, according to claim 1, it is possible to provide a metal catalyst in which the mounting strength in mounting the honeycomb core body to the outer tube is enhanced, the range of brazing is shortened so as to reduce the brazing cost, and the vibration-proofness is enhanced. [0012] In the invention as set forth in claim 2, in view of the fact that temperature is higher in the vicinity of an inlet of the metal catalyst than on the outlet side and material strength in the vicinity of the inlet is therefore lowered, the position of brazing between the flat sheet and the corrugated sheet is deviated to the outlet side with respect to the flow of an exhaust gas. With the brazing position between the flat sheet and the corrugated sheet thus deviated to the outlet side with respect to the flow of the exhaust gas, the durability of the brazed portions between the flat sheet and the corrugated sheet can be enhanced. [0013] In the invention as set forth in claim 3, the length of brazing between the flat sheet and the corrugated sheet is set in the range of 10 to 50% based on the length of the honeycomb core body. When the length of brazing between the flat sheet and the corrugated sheet is less than 10% based on the length of the honeycomb core body, the strength of the honeycomb core body is lowered, and the vibration-proof ness thereof is lowered. [0014] On the other hand, when the length of brazing between the flat sheet and the corrugated sheet is more than 5 0% based on the length of the honeycomb core body, this structure leads to increases in the cost and weight of the honeycomb core body. In addition, thermal stress is increased. [0015] Therefore, the length of brazing between the flat sheet and the corrugated sheet is set in the range of 10 to 50% based on the length of the honeycomb core body. As a result, increases in the cost and weight of the honeycomb core body can be obviated while maintaining the vibration-proofness of the honeycomb core body. [0016] In the invention as set forth in claim 4, the metal catalyst is mounted to the separator partitioning the inside of the muffler in such a manner that the position of brazing between the flat sheet and the corrugated sheet overlaps with the separator. Therefore, the brazed portions of the separator and of the metal catalyst can be matched to each other. [0017] When the brazed portions of the separator and the metal catalyst can be matched to each other, the brazed portions of the metal catalyst can be reinforced by the separator. With the brazed portions of the metal catalyst thus reinforced by the separator, it becomes possible to enhance the strength of the metal catalyst and to further enhance the vibration-proofness. [Best Mode for Carrying out the Invention] [0018] A best mode for carrying out the present invention will be described below, based on the accompanying drawings. In the following description, "front (forward)", "rear (rearward)", "left", "right", "upper (upward)" and "lower (downward)" indicate the sides or directions as viewed with reference to the muffler, and Fr denotes the front side, Rr denotes the rear side, L denotes the left side, R denotes the right side, T denotes the upper (top) side, and B denotes the lower (bottom) side. Incidentally, the drawings are to be looked at according to the posture of the symbols. [0019] Fig. 1 is a sectional view of a muffler fitted with a metal catalyst according to the present invention. The muffler 10 is composed of: a hollow cylindrical body outer 11; a body inner 17 which forms a front chamber 14, a middle chamber 15, and a rear chamber 16 in the body outer 11 by a first separator 12 disposed on the inside of the body outer 11 so as to partition the inside of the body outer 11 and a second separator 13 disposed on the rear side of the first separator 12, is disposed on the rear side of the second separator 13 and of which one end 17a is held by a circumferential shoulder portion 13a of the second separator 13; an annular ring member 21 which holds the other end 17b of the body inner 17 and which is disposed on the inside of the body outer 11; an inlet pipe 25 which includes a cap inner 22 and a cap rear member 23 provided on the rear side of the ring member 21 to close the rear side of the rear chamber 16, and a cap front member 24 for closing the front side of the front chamber 14, penetrates the first separator 12 and the second separator 13, extends from the front side of the front chamber 14 to the rear side of the rear chamber 16, and leads an exhaust gas into the rear chamber 16; a second joint member 26 connected to the inlet pipe 25 and operative to change the direction of the exhaust gas by about 180 degrees; a second tapered pipe 31 connected to the second joint member 26 to make connection between the second joint member 26 and the metal catalyst 30; the metal catalyst 3 0 disposed in connection with the second tapered pipe 31 and penetrating the second separator 13; a first tapered pipe 33 connected to the metal catalyst 3 0 to make connection between the metal catalyst 3 0 and a first joint member 32; the first joint member 32 connected to the first tapered pipe 33 and operative to change the direction of the exhaust gas by about 180 degrees; a first intermediate pipe 34 connected to the first joint member 32 and operative to lead the exhaust gas into the rear chamber 16; a second intermediate pipe 3 5 disposed to penetrate the second separator 13 and the first separator 12 and operative to lead the exhaust gas from the rear chamber 16 into the front chamber 14; a third intermediate pipe 36 disposed to penetrate the first separator 12 and operative to lead the exhaust gas from the front chamber 14 into the middle chamber 15; and an outlet pipe 37 penetrating the second separator 13, the cap inner 22 and the cap rear portion 23 and operative to lead the exhaust gas to the exterior of the muffler. [0020] Connected portions of the metal catalyst 3 0 and the first tapered pipe 33 are welded, connected portions of the first tapered pipe 33 and the first joint member 32 are welded, and connected portions of the metal catalyst 30 and the second tapered pipe 31 are welded, whereby these component parts are mutually fixed. Symbol 41 denotes a first stay member, and a weld nut 42 is attached to the first stay member 41. [0021] Specifically, the muffler 10 is a member in which the inside of the body outer 11 is partitioned by the first and second separators 12 and 13 into the three chambers, i.e., the front chamber 14, the middle chamber 15, and the rear chamber 16, the metal catalyst 30 is interposed in a part of the pipe leading the exhaust gas, the metal catalyst 30 is mounted to the second separator 13 partitioning the inside of the muffler 10, intermediate pipes 34, 35, the inlet pipe 25 and the outlet pipe 37 are mounted to the second separator 13, and the first tapered pipe 33, the first to third intermediate pipes 34, 35, 36 and the inlet pipe 25 are mounted to the first separator 12. [0022] Incidentally, the body inner 17 and the cap inner 22 are formed of punching steel plates. Formed glass wool materials 43 and 44 are placed in the space between the body outer 11 and the body inner 17 and in the space between the cap inner 22 and the cap rear member 23, so as to enhance the silencing effect. [0023] Fig. 2 is a sectional view along line 2-2 of Fig. 1, and shows that a plurality of holes 45 to 49 are opened in the first separator 12, and the pipes are mounted in the holes 45 to 49. The first intermediate pipe 34, the inlet pipe 25, the first tapered pipe 33, the third intermediate pipe 36, and the second intermediate pipe 35, in this order from the left to the right in the figure, are mounted to pass respectively through the holes 4 5 to 4 9 opened in the first separator 12 partitioning the inside of the body outer 11, and the surroundings of these pipes 25, 33 to 36 and the first separator 12 are fixed by welding. The welding range is a part of the periphery of each of the pipes. [0024] Incidentally, symbol 51 denotes a second stay member provided at the outer periphery of the body outer 11, and a weld nut 52 is attached to the second stay member 51. [0025] Fig. 3 is a sectional view along line 3-3 of Fig. 1, and shows that a plurality of holes 55 to 59 are opened in the second separator 13, and the pipes are mounted in the holes 55 to 59. The holes 55 to 59 are burring holes 55 to 59 formed by burring to be provided with flange portions 55a to 59a. The second separator 13 is different from the first separator 12, shown in the precedent figure, in some of the positions and/or sizes of the holes opened for mounting the pipes. [0026] The outlet pipe 37, the first intermediate pipe 34, the inlet pipe 25, the outer tube 61 of the metal catalyst 30, and the second intermediate pipe 35, in this order from the right to the left in the figure, are mounted to pass through the burring holes 55 to 59 opened in the second separator 13 partitioning the inside of the body outer 11. [0027] Thus, the pipes connecting between the front chamber 14 (see Fig. 1), the middle chamber 15 and the rear chamber 16 are fixed by welding to the first separator 12, and are supported by the burring holes 55 to 59 opened in the second separator 13. Therefore, as the temperature rises and falls, the pipes can be elongated and contracted in the longitudinal direction (front-rear direction), with support portions 62 • • • ( • • • indicates plurality, here and hereinafter) of the first separator 12 as reference points. [0028] To be more specific, due to the presence of the support portions 62 • • • of the first separator 12 (see Fig. 2), the pipes can be elongated and contracted to the front side and the rear side of the first separator 12, so that no thermal stress in the longitudinal direction is generated in the pipes. As a result, the durability of the muffler 10 can be enhanced, since no thermal stress in the longitudinal direction is generated in the pipes. [0029] Returning to Fig. l, the path of the exhaust gas passing through the muffler 10 will be described. First, the exhaust gas enters via the inlet pipe 25 on the front side, is changed in its direction by about 180 degrees by the second joint member 26, passes through the second tapered pipe 31 and through the metal catalyst 30 to be thereby cleaned, then passes through the first tapered pipe 33, is changed in its direction by about 180 degrees by the first joint member 32, and passes through the first intermediate pipe 34, to be led into the rear chamber 16. [0030] Next, the exhaust gas led into the rear chamber 16 passes through the second intermediate pipe 35, to be led into the front chamber 14. The exhaust gas led into the front chamber 14 passes through the third intermediate pipe 36, to be led into the middle chamber 15. Finally, the exhaust gas led into the middle chamber 15 passes through the outlet pipe 37, to be discharged to the rear side. [0031] Fig. 4 is a sectional view for illustrating the structure in the longitudinal direction of the metal catalyst according to the present invention, showing the metal catalyst 30 as taken out of the muffler 10. The metal catalyst 30 has a structure in which a flat sheet 63 and a corrugated sheet 64 are laid on each other, the laid-on sheets are wound into a rolled form and brazed to form a honeycomb core body 65, and an outer tube 61 is fitted on the outside of the honeycomb core body 65. In the figure, LI denotes the length of the outer tube, L2 denotes the length of the honeycomb core body 65, and L3 denotes the brazing length in brazing the honeycomb body 6 5 to the outer tube 61. In this embodiment, the length of L3 is equal to the length of L2. L4 denotes the brazing length in mutually fixing the flat sheet 63 and the corrugated sheet 64 in the honeycomb core body 65, and arrow 66 indicates the flow direction of the exhaust gas. The structure of the honeycomb core body 65 composed of the flat sheet 63 and the corrugated sheet 64 will be described referring to the following drawing. [0032] In the figure, the position of brazing between the flat sheet 63 and the corrugated sheet 64 was deviated to the outlet side with respect to the flow of the exhaust gas. Temperature is higher in the vicinity of the inlet of the metal catalyst 3 0 than on the outlet side, and the material strength in the vicinity of the inlet is lowered. In view of this, the position of brazing between the flat sheet 63 and the corrugated sheet 64 was provided at a position deviated to the outlet side with respect to the flow of the exhaust gas. With the brazing position between the flat sheet 63 and the corrugated sheet 64 thus deviated to the outlet side with respect to the flow of the exhaust gas, the durability of the brazed portions between the flat sheet 63 and the corrugated sheet 64 can be enhanced. [0033] In addition, the brazing range L4 between the flat sheet 63 and the corrugated sheet 64 was set to be shorter than the brazing range L2 between the honeycomb core body 65 and the outer tube 61. Specifically, the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 is set to be 10 to 50% based on the length L2 of the honeycomb core body 65. When the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 is less than 10% of the length L2 of the honeycomb core body 65, the vibration-proofness of the honeycomb core body 65 is lowered. [0034] On the other hand, when the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 is more than 50% of the length L2 of the honeycomb core body 65, it leads to increases in the cost and weight of the honeycomb core body 65. In addition, thermal stress is increased. [0035] Therefore, the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 was set in the range of 10 to 50% based on the length L2 of the honeycomb core body 65. As a result, it is possible to obviate increases in the cost and weight of the honeycomb core body 65 while maintaining the vibration-proofness of the honeycomb core body 6 5. [0036] Fig. 5 is a view along arrow 5 of Fig. 4, illustrating the structure in the radial direction of the metal catalyst. As has been described above, the metal catalyst 3 0 is composed of the honeycomb core body 65 in which the thin flat sheet 63 and the thin corrugated sheet 64 are laid on each other alternately and in a concentric manner to form a multi-layer structure, and the outer tube 61 fitted onto the outside surfaces 65a • • * of the honeycomb core body 65, i.e., the outer tube 61 is fitted on the outside surfaces 65a • • • of the honeycomb core body 65 composed of the flat sheets 63 • • * and the corrugated sheets 64 • • ■ . [0037] Specifically, the metal catalyst 30 has a configuration in which the thin flat sheets 63 • • # and the thin corrugated sheets 64 • • • are laid on each other, the laid-on sheets are wound into a rolled form, the flat sheets 63 • • • and the corrugated sheets 64 • • • are brazed to each other to form the honeycomb core body 65 having a multiplicity of cancellous passages, and the outside surfaces 65a • • • of the honeycomb core body 65 is covered by the outer tube 61, followed by brazing them to each other. [0038] Fig. 6 is an enlarged view of part 6 of Fig. 5, showing that brazed portions 71 • * * are located in the areas where apex portions 72 • • • of the corrugated sheets 64 • • • make contact with the flat sheet 63 when the thin flat sheets 63 • • • and the thin corrugated sheets 64 • • • are laid on each other and wound into a rolled form, and in the areas where the apex portions 72 * • • of the corrugated sheet 64 • • • constituting the outside surface 65a of the honeycomb core body 65 make contact with the outer tube 61. [0039] Returning to Fig. 1, the layout relationship between the brazed portions of the metal catalyst 30 and the second separator 13 in the longitudinal direction will be described. The metal catalyst 3 0 is mounted to the second separator 13 partitioning the inside of the muffler 10, and is characterized in that it is mounted to the second separator 13 in such a manner that the brazing positions 75 between the flat sheets 63 • • • and the corrugated sheets 64 * • • overlap with the second separator 13. [0040] Since the metal catalyst 3 0 is mounted to the second separator 13 in such a manner that the brazing positions 75 between the flat sheet 63 • • • and the corrugated sheets 64 • • * overlap with the second separator 13, the brazed portions of the second separator 13 and of the metal catalyst 30 can be matched to each other. [0041] When the positions of the brazed portions of the second separator 13 and of the metal catalyst 3 0 can be matched to each other, the brazed portions of the metal catalyst 3 0 can be reinforced by the second separator 13. With the brazed portions of the metal catalyst 30 reinforced by the second separator 13, it is possible to enhance the strength of the metal catalyst 3 0 and to further enhance the vibration-proofness. [0042] The functions of the present invention will be described. The metal catalyst 30 has a configuration in which the thin flat sheet 63 and the thin corrugated sheet 64 are stacked in a multi-layer form and wound into a rolled form, the flat sheet 63 and the corrugated sheet 64 are brazed to each other to form the honeycomb core body 65, the honeycomb core body 65 is covered with the outer tube 61, and they are brazed to each other. [0043] Since the range of brazing between the flat sheets 63 • • * and the corrugated sheets 64 • • • constituting the honeycomb core body 65 is set shorter than the range of brazing between the honeycomb core body 65 and the outer tube 61, the amount of brazing between the flat sheets 63 • • • and the corrugated sheets 64 can be reduced, whereby the cost and weight of the metal catalyst 30 can be reduced. In addition, the configuration in which the range of brazing between the flat sheets 63 • • • and the corrugated sheets 64 • • • is set shorter than the range of brazing between the honeycomb core body 65 and the outer tube 61 means that the range of brazing between the honeycomb core body 65 and the outer tube 61 is set long. As a result, the mounting strength in mounting the honeycomb core body 65 to the outer tube 61 can be enhanced. [0044] Furthermore, since thermal stress is decreased by setting the brazing range between the flat sheets 63 • • • and the corrugated sheets 64 • • • to be short, it is made easy to secure a predetermined strength between the flat sheets 63 • • • and the corrugated sheets 64 * • • . [0045] Since the mounting strength in mounting the honeycomb core body 65 to the outer tube 61 is enhanced while securing a predetermined strength between the flat sheets 63 • • • and the corrugated sheets 64 • • • , the vibration-proofness of the metal catalyst 30 can be further enhanced. Therefore, it is possible to provide a metal catalyst in which the mounting strength in mounting the honeycomb core body 65 to the outer tube 61 is enhanced, the brazing range is shortened to reduce the brazing cost, and vibration-proofness is enhanced. [0046] Fig. 7 is a view showing another embodiment of Fig. 4. The metal catalyst 30 is a member in which the outer tube 61 is fitted onto the honeycomb core body 65 composed of the flat sheets 63 • • # and the corrugated sheets 64 * # • . Symbol LI denotes the length of the outer tube, L2 denotes the length of the honeycomb core body 65, L3 denotes the length of brazing of the honeycomb core body 65 to the outer tube 61, and L4 denotes the brazing length inside the honeycomb core body 65. [0047] Fig. 7 is largely different from Fig. 4 in that the brazing length L4 inside the honeycomb core body 65 is set shorter than the length L3 of the honeycomb core body 65, and this configuration is preferable for such cases as a case where it is desired to set the length LI of the outer tube 61 of the metal catalyst 3 0 to be large. [0048] Incidentally, in claim 1, the position of brazing between the flat sheet and the corrugated sheet may be provided at a position not deviated to the outlet side with respect to the flow of the exhaust gas. [Industrial Applicability] [0049] The present invention is preferable for a motorcycle. [Brief Description of the Drawings] [0050] [Fig. 1] Fig. 1 is a sectional view of a muffler fitted with a metal catalyst according to the present invention. [Fig. 2] Fig. 2 is a sectional view along line 2-2 of Fig. 1. [Fig. 3] Fig. 3 is a sectional view along line 3-3 of Fig. 1. [Fig. 4] Fig. 4 is a sectional view for illustrating the structure in the longitudinal direction of the metal catalyst according to the present invention. [Fig. 5] Fig. 5 is a view along arrow 5 of Fig. 4. [Fig. 6] Fig. 6 is an enlarged view of part 6 of Fig. 5. [Fig. 7] Fig. 7 is a view showing another embodiment of Fig. 4. [Description of Reference Symbols] [0051] 10: muffler; 12: first separator; 30: metal catalyst; 61: outer tube; 63: flat sheet; 64: corrugated sheet; 65: honeycomb core body; 65a: outside surface of honeycomb core body. [Name of Document] Claims [Claim 1] A metal catalyst produced by laying a thin flat sheet and a thin corrugated sheet on each other, winding said laid-on sheets into a rolled form, brazing said flat sheet and said corrugated sheet to each other to form a honeycomb core body having a multiplicity of cancellous passages, covering the outside surface of said honeycomb core body with an outer tube, and brazing said honeycomb core body and said outer tube to each other, wherein the range of brazing between said flat sheet and said corrugated sheet is shorter than the range of brazing between said honeycomb core body and said outer tube. [Claim 2] The metal catalyst as set forth in claim 1, wherein the position of brazing between said flat sheet and said corrugated sheet is deviated to the outlet side with respect to a flow of an exhaust gas. [Claim 3] The metal catalyst as set forth in claim 1 or 2, wherein the length of brazing between said flat sheet and said corrugated sheet is 10 to 50% based on the length of said honeycomb core body. [Claim 4] The metal catalyst wherein a metal catalyst as set forth in claim 1, 2 or 3 is mounted to a separator partitioning the inside of a muffler in such a manner that the position of brazing between said flat sheet and said corrugated sheet overlaps with said separator. [Name of Document] Claims [Claim 1] A metal catalyst produced by laying a thin flat sheet and a thin corrugated sheet on each other, winding said laid-on sheets into a rolled form, brazing said flat sheet and said corrugated sheet to each other to form a honeycomb core body having a multiplicity of cancellous passages, covering the outside surface of said honeycomb core body with an outer tube, and brazing said honeycomb core body and said outer tube to each other, wherein the range of brazing between said flat sheet and said corrugated sheet is shorter than the range of brazing between said honeycomb core body and said outer tube. [Claim 2] The metal catalyst as set forth in claim 1, wherein the position of brazing between said flat sheet and said corrugated sheet is deviated to the outlet side with respect to a flow of an exhaust gas. [Claim 3] The metal catalyst as set forth in claim 1 or 2, wherein the length of brazing between said flat sheet and said corrugated sheet is 10 to 50% based on the length of said honeycomb core body. [Claim 4] The metal catalyst wherein a metal catalyst as set forth in claim 1, 2 or 3 is mounted to a separator partitioning the inside of a muffler in such a manner that the position of brazing between said flat sheet and said corrugated sheet overlaps with said separator.

Full Text

[Name of Document] Specification [Title of the Invention]
METAL CATALYST [Technical Field] [0001]
The present invention relates to an improvement in a brazing structure for a metal catalyst including a honeycomb core body having a flat sheet and a corrugated sheet laid on each other, and an outer tube covering the outside surface of the honeycomb core body. [Background Art] [0002]
Conventionally, a metal catalyst has been proposed in which a flat sheet and a corrugated sheet are laid on each other and are brazed to each other to form a honeycomb core body, and the honeycomb core body and an outer tube are brazed to each other (see, for example, Patent Document 1).
[Patent Document 1]
Japanese Patent Laid-Open No. Hei 9-267044 (Fig. 1) [0003]
Fig. 1 in Patent Document 1 shows vertical sectional views of a metal support for a catalyst device, in which Fig. 1(A) is a vertical sectional view

containing the axis, and Fig. 1(B) is a schematic vertical sectional view showing the relationships between the members constituting Fig. 1(A).
The metal support 10 (hereinafter referred to as the metal catalyst 10) (the symbols used in the patent document are used here) is composed of a honeycomb body 4 obtained by winding an alternately laid stack of a corrugated sheet member 1 and a flat sheet member 2 into a rolled form, with brazing materials 3a and 3b therebetween, and an outer tube 5 provided on the outer periphery of the honeycomb body 4, with a brazing material 3a therebetween. Then, the interposed brazing materials 3a and 3b are melted, to fuse the members to each other. The brazing materials 3a and 3b are disposed in a brazing region 3, in order to relax the thermal stresses generated in the honeycomb body 4. [0004]
However, the length of brazing between the flat sheet member 2 and the corrugated sheet member 1 constituting the honeycomb body 4 is equal to the length of brazing between the honeycomb body 4 and the outer tube 5. Therefore, when the length of brazing between the flat sheet member 2 and the corrugated sheet member 1 is shortened, the length of brazing between the honeycomb

body 4 and the outer tube 5 is also shortened, resulting in an insufficient mounting strength of the honeycomb body 4.
[Disclosure of the Invention] [Problems to be Solved by the Invention] [0005]
In recent years, attendant on enhancement of the performance such as output of motorcycles, there has been an increasing demand for enhancement of the mounting strength of a metal catalyst. On the other hand, a further reduction in cost is also expected.
In view of this, it is an object of the present invention to provide a metal catalyst in which the mounting strength in mounting a honeycomb core body to an outer tube is enhanced, the range of brazing is shortened so as to reduce the brazing cost, and vibration-proofness is enhanced.
[Means for Solving the Problems] [0006]
The invention as set forth in claim 1 resides in a metal catalyst produced by laying a thin flat sheet and a thin corrugated sheet on each other, winding the laid-on sheets into a rolled form, brazing the flat sheet and the corrugated sheet to each other to form a honeycomb core

body having a multiplicity of cancellous passages, covering the outside surface of the honeycomb core body with an outer tube, and brazing the honeycomb core body and the outer tube to each other, characterized in that the range of brazing between the flat sheet and the corrugated sheet is shorter than the range of brazing between the honeycomb core body and the outer tube. [0007]
The invention as set forth in claim 2 is
characterized in that the position of brazing between the flat sheet and the corrugated sheet is deviated to the outlet side with respect to a flow of an exhaust gas. [0008]
The invention as set forth in claim 3 is characterized in that the length of brazing between the flat sheet and the corrugated sheet is 10 to 50% based on the length of the honeycomb core body. [0009]
The invention as set forth in claim 4 is characterized in that a metal catalyst as set forth in claim 1, 2 or 3 is mounted to a separator partitioning the inside of a muffler in such a manner that the position of brazing between the flat sheet and the corrugated sheet overlaps with the separator.

[Effects of the Invention] [0010]
In the invention as set forth in claim 1, the range of brazing between the flat sheet and the corrugated sheet is set shorter than the range of brazing between the honeycomb core body and the outer tube, which makes it possible to reduce the amount of brazing between the flat sheet and the corrugated sheet and to reduce the cost and weight of the metal catalyst.
In addition, the configuration in which the range of brazing between the flat sheet and the corrugated sheet is shorter than the range of brazing between the honeycomb core body and the outer tube means that the range of brazing between the honeycomb core body and the outer tube is set long.
As a result, the mounting strength in mounting the honeycomb core body to the outer tube can be enhanced. [0011]
Further, since the setting of the range of brazing between the flat sheet and the corrugated sheet to be short provides a reduction in thermal stress, it is easy to secure a predetermined strength between the flat sheet and the corrugated sheet.
Since the mounting strength in mounting the

honeycomb core body to the outer tube is enhanced while securing a predetermined strength between the flat sheet and the corrugated sheet, the vibration-proofness of the metal catalyst can be enhanced.
Therefore, according to claim 1, it is possible to provide a metal catalyst in which the mounting strength in mounting the honeycomb core body to the outer tube is enhanced, the range of brazing is shortened so as to reduce the brazing cost, and the vibration-proofness is enhanced. [0012]
In the invention as set forth in claim 2, in view of the fact that temperature is higher in the vicinity of an inlet of the metal catalyst than on the outlet side and material strength in the vicinity of the inlet is therefore lowered, the position of brazing between the flat sheet and the corrugated sheet is deviated to the outlet side with respect to the flow of an exhaust gas. With the brazing position between the flat sheet and the corrugated sheet thus deviated to the outlet side with respect to the flow of the exhaust gas, the durability of the brazed portions between the flat sheet and the corrugated sheet can be enhanced. [0013]

In the invention as set forth in claim 3, the length of brazing between the flat sheet and the corrugated sheet is set in the range of 10 to 50% based on the length of the honeycomb core body.
When the length of brazing between the flat sheet and the corrugated sheet is less than 10% based on the length of the honeycomb core body, the strength of the honeycomb core body is lowered, and the vibration-proof ness thereof is lowered. [0014]
On the other hand, when the length of brazing between the flat sheet and the corrugated sheet is more than 5 0% based on the length of the honeycomb core body, this structure leads to increases in the cost and weight of the honeycomb core body. In addition, thermal stress is increased. [0015]
Therefore, the length of brazing between the flat sheet and the corrugated sheet is set in the range of 10 to 50% based on the length of the honeycomb core body.
As a result, increases in the cost and weight of the honeycomb core body can be obviated while maintaining the vibration-proofness of the honeycomb core body. [0016]

In the invention as set forth in claim 4, the metal catalyst is mounted to the separator partitioning the inside of the muffler in such a manner that the position of brazing between the flat sheet and the corrugated sheet overlaps with the separator. Therefore, the brazed portions of the separator and of the metal catalyst can be matched to each other. [0017]
When the brazed portions of the separator and the metal catalyst can be matched to each other, the brazed portions of the metal catalyst can be reinforced by the separator.
With the brazed portions of the metal catalyst thus reinforced by the separator, it becomes possible to enhance the strength of the metal catalyst and to further enhance the vibration-proofness. [Best Mode for Carrying out the Invention] [0018]
A best mode for carrying out the present invention will be described below, based on the accompanying drawings.
In the following description, "front (forward)", "rear (rearward)", "left", "right", "upper (upward)" and "lower (downward)" indicate the sides or directions as

viewed with reference to the muffler, and Fr denotes the front side, Rr denotes the rear side, L denotes the left side, R denotes the right side, T denotes the upper (top) side, and B denotes the lower (bottom) side. Incidentally, the drawings are to be looked at according to the posture of the symbols. [0019]
Fig. 1 is a sectional view of a muffler fitted with a metal catalyst according to the present invention. The muffler 10 is composed of: a hollow cylindrical body outer 11; a body inner 17 which forms a front chamber 14, a middle chamber 15, and a rear chamber 16 in the body outer 11 by a first separator 12 disposed on the inside of the body outer 11 so as to partition the inside of the body outer 11 and a second separator 13 disposed on the rear side of the first separator 12, is disposed on the rear side of the second separator 13 and of which one end 17a is held by a circumferential shoulder portion 13a of the second separator 13; an annular ring member 21 which holds the other end 17b of the body inner 17 and which is disposed on the inside of the body outer 11; an inlet pipe 25 which includes a cap inner 22 and a cap rear member 23 provided on the rear side of the ring member 21 to close the rear side of the rear chamber 16, and a cap

front member 24 for closing the front side of the front chamber 14, penetrates the first separator 12 and the second separator 13, extends from the front side of the front chamber 14 to the rear side of the rear chamber 16, and leads an exhaust gas into the rear chamber 16; a second joint member 26 connected to the inlet pipe 25 and operative to change the direction of the exhaust gas by about 180 degrees; a second tapered pipe 31 connected to the second joint member 26 to make connection between the second joint member 26 and the metal catalyst 30; the metal catalyst 3 0 disposed in connection with the second tapered pipe 31 and penetrating the second separator 13; a first tapered pipe 33 connected to the metal catalyst 3 0 to make connection between the metal catalyst 3 0 and a first joint member 32; the first joint member 32 connected to the first tapered pipe 33 and operative to change the direction of the exhaust gas by about 180 degrees; a first intermediate pipe 34 connected to the first joint member 32 and operative to lead the exhaust gas into the rear chamber 16; a second intermediate pipe 3 5 disposed to penetrate the second separator 13 and the first separator 12 and operative to lead the exhaust gas from the rear chamber 16 into the front chamber 14; a third intermediate pipe 36 disposed to penetrate the

first separator 12 and operative to lead the exhaust gas from the front chamber 14 into the middle chamber 15; and an outlet pipe 37 penetrating the second separator 13, the cap inner 22 and the cap rear portion 23 and operative to lead the exhaust gas to the exterior of the muffler. [0020]
Connected portions of the metal catalyst 3 0 and the first tapered pipe 33 are welded, connected portions of the first tapered pipe 33 and the first joint member 32 are welded, and connected portions of the metal catalyst 30 and the second tapered pipe 31 are welded, whereby these component parts are mutually fixed.
Symbol 41 denotes a first stay member, and a weld nut 42 is attached to the first stay member 41. [0021]
Specifically, the muffler 10 is a member in which the inside of the body outer 11 is partitioned by the first and second separators 12 and 13 into the three chambers, i.e., the front chamber 14, the middle chamber 15, and the rear chamber 16, the metal catalyst 30 is interposed in a part of the pipe leading the exhaust gas, the metal catalyst 30 is mounted to the second separator 13 partitioning the inside of the muffler 10,

intermediate pipes 34, 35, the inlet pipe 25 and the outlet pipe 37 are mounted to the second separator 13, and the first tapered pipe 33, the first to third intermediate pipes 34, 35, 36 and the inlet pipe 25 are mounted to the first separator 12. [0022]
Incidentally, the body inner 17 and the cap inner 22 are formed of punching steel plates. Formed glass wool materials 43 and 44 are placed in the space between the body outer 11 and the body inner 17 and in the space between the cap inner 22 and the cap rear member 23, so as to enhance the silencing effect. [0023]
Fig. 2 is a sectional view along line 2-2 of Fig. 1, and shows that a plurality of holes 45 to 49 are opened in the first separator 12, and the pipes are mounted in the holes 45 to 49.
The first intermediate pipe 34, the inlet pipe 25, the first tapered pipe 33, the third intermediate pipe 36, and the second intermediate pipe 35, in this order from the left to the right in the figure, are mounted to pass respectively through the holes 4 5 to 4 9 opened in the first separator 12 partitioning the inside of the body outer 11, and the surroundings of these pipes 25, 33

to 36 and the first separator 12 are fixed by welding. The welding range is a part of the periphery of each of the pipes. [0024]
Incidentally, symbol 51 denotes a second stay member provided at the outer periphery of the body outer 11, and a weld nut 52 is attached to the second stay member 51. [0025]
Fig. 3 is a sectional view along line 3-3 of Fig. 1, and shows that a plurality of holes 55 to 59 are opened in the second separator 13, and the pipes are mounted in the holes 55 to 59. The holes 55 to 59 are burring holes 55 to 59 formed by burring to be provided with flange portions 55a to 59a. The second separator 13 is different from the first separator 12, shown in the precedent figure, in some of the positions and/or sizes of the holes opened for mounting the pipes. [0026]
The outlet pipe 37, the first intermediate pipe 34, the inlet pipe 25, the outer tube 61 of the metal catalyst 30, and the second intermediate pipe 35, in this order from the right to the left in the figure, are mounted to pass through the burring holes 55 to 59 opened

in the second separator 13 partitioning the inside of the body outer 11.
[0027]
Thus, the pipes connecting between the front chamber 14 (see Fig. 1), the middle chamber 15 and the rear chamber 16 are fixed by welding to the first separator 12, and are supported by the burring holes 55 to 59 opened in the second separator 13. Therefore, as the temperature rises and falls, the pipes can be elongated and contracted in the longitudinal direction
(front-rear direction), with support portions 62 • • • ( •
• • indicates plurality, here and hereinafter) of the first separator 12 as reference points.
[0028]
To be more specific, due to the presence of the
support portions 62 • • • of the first separator 12 (see Fig. 2), the pipes can be elongated and contracted to the front side and the rear side of the first separator 12, so that no thermal stress in the longitudinal direction is generated in the pipes.
As a result, the durability of the muffler 10 can be enhanced, since no thermal stress in the longitudinal direction is generated in the pipes. [0029]

Returning to Fig. l, the path of the exhaust gas passing through the muffler 10 will be described.
First, the exhaust gas enters via the inlet pipe 25 on the front side, is changed in its direction by about 180 degrees by the second joint member 26, passes through the second tapered pipe 31 and through the metal catalyst 30 to be thereby cleaned, then passes through the first tapered pipe 33, is changed in its direction by about 180 degrees by the first joint member 32, and passes through the first intermediate pipe 34, to be led into the rear chamber 16. [0030]
Next, the exhaust gas led into the rear chamber 16 passes through the second intermediate pipe 35, to be led into the front chamber 14. The exhaust gas led into the front chamber 14 passes through the third intermediate pipe 36, to be led into the middle chamber 15.
Finally, the exhaust gas led into the middle chamber 15 passes through the outlet pipe 37, to be discharged to the rear side. [0031]
Fig. 4 is a sectional view for illustrating the structure in the longitudinal direction of the metal catalyst according to the present invention, showing the

metal catalyst 30 as taken out of the muffler 10. The metal catalyst 30 has a structure in which a flat sheet 63 and a corrugated sheet 64 are laid on each other, the laid-on sheets are wound into a rolled form and brazed to form a honeycomb core body 65, and an outer tube 61 is fitted on the outside of the honeycomb core body 65. In the figure, LI denotes the length of the outer tube, L2 denotes the length of the honeycomb core body 65, and L3 denotes the brazing length in brazing the honeycomb body 6 5 to the outer tube 61. In this embodiment, the length of L3 is equal to the length of L2. L4 denotes the brazing length in mutually fixing the flat sheet 63 and the corrugated sheet 64 in the honeycomb core body 65, and arrow 66 indicates the flow direction of the exhaust gas.
The structure of the honeycomb core body 65 composed of the flat sheet 63 and the corrugated sheet 64 will be described referring to the following drawing. [0032]
In the figure, the position of brazing between the flat sheet 63 and the corrugated sheet 64 was deviated to the outlet side with respect to the flow of the exhaust gas. Temperature is higher in the vicinity of the inlet of the metal catalyst 3 0 than on the outlet side, and the

material strength in the vicinity of the inlet is lowered. In view of this, the position of brazing between the flat sheet 63 and the corrugated sheet 64 was provided at a position deviated to the outlet side with respect to the flow of the exhaust gas. With the brazing position between the flat sheet 63 and the corrugated sheet 64 thus deviated to the outlet side with respect to the flow of the exhaust gas, the durability of the brazed portions between the flat sheet 63 and the corrugated sheet 64 can be enhanced. [0033]
In addition, the brazing range L4 between the flat sheet 63 and the corrugated sheet 64 was set to be shorter than the brazing range L2 between the honeycomb core body 65 and the outer tube 61.
Specifically, the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 is set to be 10 to 50% based on the length L2 of the honeycomb core body 65.
When the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 is less than 10% of the length L2 of the honeycomb core body 65, the vibration-proofness of the honeycomb core body 65 is lowered. [0034]

On the other hand, when the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 is more than 50% of the length L2 of the honeycomb core body 65, it leads to increases in the cost and weight of the honeycomb core body 65. In addition, thermal stress is increased. [0035]
Therefore, the brazing length L4 between the flat sheet 63 and the corrugated sheet 64 was set in the range of 10 to 50% based on the length L2 of the honeycomb core body 65.
As a result, it is possible to obviate increases in the cost and weight of the honeycomb core body 65 while maintaining the vibration-proofness of the honeycomb core body 6 5. [0036]
Fig. 5 is a view along arrow 5 of Fig. 4,
illustrating the structure in the radial direction of the metal catalyst. As has been described above, the metal catalyst 3 0 is composed of the honeycomb core body 65 in which the thin flat sheet 63 and the thin corrugated sheet 64 are laid on each other alternately and in a concentric manner to form a multi-layer structure, and the outer tube 61 fitted onto the outside surfaces 65a • •

* of the honeycomb core body 65, i.e., the outer tube 61
is fitted on the outside surfaces 65a • • • of the
honeycomb core body 65 composed of the flat sheets 63 • •
* and the corrugated sheets 64 • • ■ .
[0037]
Specifically, the metal catalyst 30 has a configuration in which the thin flat sheets 63 • • # and the thin corrugated sheets 64 • • • are laid on each other, the laid-on sheets are wound into a rolled form, the flat
sheets 63 • • • and the corrugated sheets 64 • • • are brazed to each other to form the honeycomb core body 65 having a multiplicity of cancellous passages, and the
outside surfaces 65a • • • of the honeycomb core body 65 is covered by the outer tube 61, followed by brazing them to each other. [0038]
Fig. 6 is an enlarged view of part 6 of Fig. 5, showing that brazed portions 71 • * * are located in the areas where apex portions 72 • • • of the corrugated sheets 64 • • • make contact with the flat sheet 63 when the thin flat sheets 63 • • • and the thin corrugated sheets 64 • • • are laid on each other and wound into a rolled form, and
in the areas where the apex portions 72 * • • of the corrugated sheet 64 • • • constituting the outside surface

65a of the honeycomb core body 65 make contact with the outer tube 61. [0039]
Returning to Fig. 1, the layout relationship between the brazed portions of the metal catalyst 30 and the second separator 13 in the longitudinal direction will be described.
The metal catalyst 3 0 is mounted to the second separator 13 partitioning the inside of the muffler 10, and is characterized in that it is mounted to the second separator 13 in such a manner that the brazing positions 75 between the flat sheets 63 • • • and the corrugated sheets 64 * • • overlap with the second separator 13. [0040]
Since the metal catalyst 3 0 is mounted to the second separator 13 in such a manner that the brazing positions 75 between the flat sheet 63 • • • and the corrugated sheets 64 • • * overlap with the second separator 13, the brazed portions of the second separator
13 and of the metal catalyst 30 can be matched to each other. [0041]
When the positions of the brazed portions of the second separator 13 and of the metal catalyst 3 0 can be

matched to each other, the brazed portions of the metal catalyst 3 0 can be reinforced by the second separator 13.
With the brazed portions of the metal catalyst 30 reinforced by the second separator 13, it is possible to enhance the strength of the metal catalyst 3 0 and to further enhance the vibration-proofness. [0042]
The functions of the present invention will be described.
The metal catalyst 30 has a configuration in which the thin flat sheet 63 and the thin corrugated sheet 64 are stacked in a multi-layer form and wound into a rolled form, the flat sheet 63 and the corrugated sheet 64 are brazed to each other to form the honeycomb core body 65, the honeycomb core body 65 is covered with the outer tube 61, and they are brazed to each other. [0043]
Since the range of brazing between the flat sheets
63 • • * and the corrugated sheets 64 • • • constituting the honeycomb core body 65 is set shorter than the range of brazing between the honeycomb core body 65 and the outer tube 61, the amount of brazing between the flat sheets 63
• • • and the corrugated sheets 64 can be reduced, whereby the cost and weight of the metal catalyst 30 can be

reduced.
In addition, the configuration in which the range of brazing between the flat sheets 63 • • • and the corrugated sheets 64 • • • is set shorter than the range of brazing between the honeycomb core body 65 and the outer tube 61 means that the range of brazing between the honeycomb core body 65 and the outer tube 61 is set long.
As a result, the mounting strength in mounting the honeycomb core body 65 to the outer tube 61 can be enhanced. [0044]
Furthermore, since thermal stress is decreased by setting the brazing range between the flat sheets 63 • • • and the corrugated sheets 64 • • • to be short, it is made easy to secure a predetermined strength between the flat
sheets 63 • • • and the corrugated sheets 64 * • • . [0045]
Since the mounting strength in mounting the honeycomb core body 65 to the outer tube 61 is enhanced while securing a predetermined strength between the flat
sheets 63 • • • and the corrugated sheets 64 • • • , the vibration-proofness of the metal catalyst 30 can be further enhanced.
Therefore, it is possible to provide a metal

catalyst in which the mounting strength in mounting the honeycomb core body 65 to the outer tube 61 is enhanced, the brazing range is shortened to reduce the brazing cost, and vibration-proofness is enhanced. [0046]
Fig. 7 is a view showing another embodiment of Fig. 4.
The metal catalyst 30 is a member in which the outer tube 61 is fitted onto the honeycomb core body 65 composed of the flat sheets 63 • • # and the corrugated sheets 64 * # • . Symbol LI denotes the length of the outer tube, L2 denotes the length of the honeycomb core body 65, L3 denotes the length of brazing of the honeycomb core body 65 to the outer tube 61, and L4 denotes the brazing length inside the honeycomb core body 65.
[0047]
Fig. 7 is largely different from Fig. 4 in that the brazing length L4 inside the honeycomb core body 65 is set shorter than the length L3 of the honeycomb core body 65, and this configuration is preferable for such cases as a case where it is desired to set the length LI of the outer tube 61 of the metal catalyst 3 0 to be large.
[0048]
Incidentally, in claim 1, the position of brazing

between the flat sheet and the corrugated sheet may be provided at a position not deviated to the outlet side with respect to the flow of the exhaust gas. [Industrial Applicability] [0049]
The present invention is preferable for a motorcycle.
[Brief Description of the Drawings] [0050] [Fig. 1]
Fig. 1 is a sectional view of a muffler fitted with a metal catalyst according to the present invention. [Fig. 2]
Fig. 2 is a sectional view along line 2-2 of Fig. 1. [Fig. 3]
Fig. 3 is a sectional view along line 3-3 of Fig. 1. [Fig. 4]
Fig. 4 is a sectional view for illustrating the structure in the longitudinal direction of the metal catalyst according to the present invention. [Fig. 5]
Fig. 5 is a view along arrow 5 of Fig. 4.

[Fig. 6]
Fig. 6 is an enlarged view of part 6 of Fig. 5. [Fig. 7]
Fig. 7 is a view showing another embodiment of Fig. 4.
[Description of Reference Symbols] [0051]
10: muffler; 12: first separator; 30: metal catalyst; 61: outer tube; 63: flat sheet; 64: corrugated sheet; 65: honeycomb core body; 65a: outside surface of honeycomb core body.

[Name of Document] Claims [Claim 1]
A metal catalyst produced by laying a thin flat sheet and a thin corrugated sheet on each other, winding said laid-on sheets into a rolled form, brazing said flat sheet and said corrugated sheet to each other to form a honeycomb core body having a multiplicity of cancellous passages, covering the outside surface of said honeycomb core body with an outer tube, and brazing said honeycomb core body and said outer tube to each other, wherein
the range of brazing between said flat sheet and said corrugated sheet is shorter than the range of brazing between said honeycomb core body and said outer tube. [Claim 2]
The metal catalyst as set forth in claim 1, wherein the position of brazing between said flat sheet and said corrugated sheet is deviated to the outlet side with respect to a flow of an exhaust gas. [Claim 3]
The metal catalyst as set forth in claim 1 or 2, wherein the length of brazing between said flat sheet and said corrugated sheet is 10 to 50% based on the length of said honeycomb core body.

[Claim 4]
The metal catalyst wherein a metal catalyst as set forth in claim 1, 2 or 3 is mounted to a separator partitioning the inside of a muffler in such a manner that the position of brazing between said flat sheet and said corrugated sheet overlaps with said separator.

[Name of Document] Claims [Claim 1]
A metal catalyst produced by laying a thin flat sheet and a thin corrugated sheet on each other, winding said laid-on sheets into a rolled form, brazing said flat sheet and said corrugated sheet to each other to form a honeycomb core body having a multiplicity of cancellous passages, covering the outside surface of said honeycomb core body with an outer tube, and brazing said honeycomb core body and said outer tube to each other, wherein
the range of brazing between said flat sheet and said corrugated sheet is shorter than the range of brazing between said honeycomb core body and said outer tube. [Claim 2]
The metal catalyst as set forth in claim 1, wherein the position of brazing between said flat sheet and said corrugated sheet is deviated to the outlet side with respect to a flow of an exhaust gas. [Claim 3]
The metal catalyst as set forth in claim 1 or 2, wherein the length of brazing between said flat sheet and said corrugated sheet is 10 to 50% based on the length of said honeycomb core body.

[Claim 4]
The metal catalyst wherein a metal catalyst as set forth in claim 1, 2 or 3 is mounted to a separator partitioning the inside of a muffler in such a manner that the position of brazing between said flat sheet and said corrugated sheet overlaps with said separator.

Documents:

258-che-2006-abstract.pdf

258-che-2006-claims.pdf

258-che-2006-correspondence-others.pdf

258-che-2006-description(complete).pdf

258-che-2006-drawings.pdf

258-che-2006-fig-5.jpg

258-che-2006-form1.pdf

258-che-2006-form3.pdf

258-che-2006-form5.pdf

258-che-2006-prioritydocument.pdf

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Patent Number

234078

Indian Patent Application Number

258/CHE/2006

PG Journal Number

22/2009

Publication Date

29-May-2009

Grant Date

05-May-2009

Date of Filing

17-Feb-2006

Name of Patentee

HONDA MOTOR CO., LTD

Applicant Address

1-1 MINAMIAOYAMA 2-CHOME, MINATO-KU TOKYO,

Inventors:

#	Inventor's Name	Inventor's Address
1	OKUBO, KATSUNORI	C/O KABYSHIKI KAISHA HOND AGIJUTSU KENYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA,
2	ODAGIRI HIROSHI	C/O KABYSHIKI KAISHA HOND AGIJUTSU KENYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA,

PCT International Classification Number

B01J 27/18

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2005-044363	2005-02-21	Japan