Indian Patents. 214059:A LOUVER OF A COVER

Title of Invention	A LOUVER OF A COVER
Abstract	A louver mounted in a cover which covers an object to be cooled is to be provided so as to effectively prevent the entry of a foreign matter into the cover and permit cooling air to be introduced smoothly into the cover. Fins 84 are formed in a shape such that the spacing between outer ends of adjacent fins is narrower than the spacing between inner ends of adjacent fins.

Full Text	FORM 2 THE PATENTS ACT, 1970 [39 OF 1970] & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See Section 10; rule 13] "A LOUVER OF A COVER" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan The following specification particularly describes the nature of the invention and the manner in which it is to be performed:- ORIGINAL 348/MUM/2000 GRANTED 25-4-2005 [Detailed Description of the Invention] [0001] [Technical Field of the Invention] The present invention relates to an improvement of a louver of a cover which covers an object to be cooled, as well as an improvement of a mold assembly for molding a cover of a synthetic resin having the louver. [0002] [Prior Art] A cover which covers a heat radiating portion of an engine mounted on a motorcycle and which is provided with a louver, is disclosed in Japanese Registered Utility Model Application No. 2573000. [0003] [Problem to be Solved by the Invention] The louver is for uniforming the flow of cooling air into a cover, for suppressing leak to the exterior of a noise generated in the cover, and for preventing the entry of a foreign matter into the cover. In the above conventional louver, in order to attain such effects, a plurality of fins are provided in the cover so as to be arranged within a cooling air intake port and so as to be inclined rectilinearly in an air flowing direction of an air flow passage formed between adjacent fins. [0004] For effectively preventing the entry of a foreign matter into the cover it is desirable that the spacing between outer ends of adjacent fins be narrow. In the above conventional louver, however, if the spacing between outer ends of adjacent fins is set narrow, the flow area of an air flow passage between adjacent fins becomes smaller throughout the overall length in the air flowing direction, so that the flow resistance of cooling air flowing through the air flow passage becomes large. [0005] The present invention has been accomplished in view of the above-mentioned circumstances and it is an object of the invention to provide a louver of a cover capable of effectively preventing the entry of a foreign matter into the cover and capable of introducing cooling air smoothly into the cover [0006] [Means for Solving the Problem] For achieving the above-mentioned object, according to the invention according to claim 1 there is provided a louver of a cover, having a plurality of fins which divide a cooling air inlet port into a plurality of air flow passages, the fins being provided in the cover in an arrangement such that a straight line connecting between an outer end center and an inner end center of each air flow passage is inclined relative to a center line of the air intake port, the cover having the cooling air intake port and covering an object to be cooled, the cooling air intake port being open toward the object to be cooled, characterized in that the fins are formed in a shape such that the spacing between outer ends of adjacent fins is narrower than the spacing between inner ends of adjacent fins. [0007] According to this configuration, the entry of a foreign matter into the cover can be prevented effectively by setting the spacing between outer ends of adjacent fins relatively narrow. Besides, since the spacing between inner ends of adjacent fins is relatively wide, the flow area of the air flow passage between adjacent fins does not become small throughout the overall length of each air flow passage although it becomes small in part of the outer end side of each fin, whereby cooling air can be introduced smoothly into the cover while uniforming its flow in each air flow passage and while preventing a great increase in flow resistance of the cooling air. [0008] According to the invention according to claim 2, in combination with the invention according to claim 1, there is provided a louver of a cover wherein the fins are formed of a synthetic resin and integral with the cover and each comprise a main fin portion which extends inclinedly relative to the center line of the cooling air intake port and whose outer end is flush with and contiguous to an outer-end peripheral edge portion of the cooling air intake port and a projecting portion which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion and which projects toward the fin adjacent thereto. According to this configuration, by merely increasing the wall thickness on the outer end side of each fin partially it is possible to obtain the fin shape described in claim 1 and hence possible to prevent a partial increase in weight of the fins, or the covers. [0009] According to the invention according to claim 3 there is provided a mold assembly for molding the cover having the louver described in claim 2, comprising a first mold having a first molding portion for forming an outer side face and an outer end face of the main fin portion and an outer surface and a tip end face of the projecting portion and a second mold having a second molding portion for forming an inner side face and an inner end face of the main fin portion and an inner surface of the projecting portion. According to this mold assembly, by setting a parting face of the first and second molds inwards relative to the outer end position of the fins, it is possible to prevent the formation of burr or a sharp edge at the outer end portion of each fin and thereby improve the appearance and commercial value of the cover. Further, by forming an inner surface of the projecting portion at the front end of the second molding portion of the second mold, the spacing between adjacent fins can be narrowed while ensuring a required front end width of each of the first and second molding portions, thus also permitting the improvement in the commercial value of the cover. [Mode for carrying out the Invention] A mode for carrying out the invention will be described below by way of an embodiment thereof illustrated in the accompanying drawings, Accordingly, the present invention relates to a louver of a cover, having a plurality of fins which divide a cooling air inlet port into a plurality of air flow passages, said fins being provided in the cover in an arrangement such that a straight line (L) connecting between an outer end center and an inner end center of each said air flow passage is inclined relative to a center line (C) of said air intake port, said cover having said cooling air intake port and covering an object to be cooled, said cooling air intake port being open toward the object to be cooled, characterized in that said fins are formed in a shape such that the spacing between outer ends of adjacent said fins is narrower than the spacing between inner ends of adjacent said fins. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Fig. 1 is an entire side view of a scooter type motorcycle; Fig. 2 is an enlarged view of a principal portion of Fig. 1; Fig. 3 is a sectional view taken on line 3-3 in Fig. 2; Fig. 4 is a view as seen in the arrowed direction 4-4 in Fig. 3; Fig. 5 is a sectional view taken on line 5-5 in Fig. 4; Fig. 6 is a side view of a cover; Fig. 7 is a sectional view taken on line 7-7 in Fig. 6; Fig. 8 is a sectional view taken on line 8-8 in Fig. 6; and Fig. 9 is a sectional view showing a part of a mold assembly. [0011] Figs. 1 to 9 illustrate an embodiment of the present invention, of which Fig. 1 is an entire side view of a scooter type motorcycle, Fig. 2 is an enlarged view of a principal portion of Fig. 1, Fig. 3 is a sectional view taken on line 3-3 in Fig. 2, Fig. 4 is a view as seen in the arrowed direction 4-4 in Fig. 3, Fig. 5 is a sectional view taken on line 5-5 in Fig. 4, Fig. 6 is a side view of a cover, Fig. 7 is a sectional view taken on line 7-7 in Fig. 6, Fig. 8 is a sectional view taken on line 8-8 in Fig. 6, and Fig. 9 is a sectional view showing a part of a mold assembly. [0012] First in Figs. 1 and 2, in a scooter type motorcycle V provided with a front wheel wf which is steered by a steering handle 11 and a rear wheel wr which is driven by a swing type power unit P, a body frame F is divided into three, that is, a front frame 12, a center frame 13, and a rear frame 14. The front frame 12 is an aluminum alloy cast frame integrally provided with a head pipe 121, a down tube 122, and a step floor support portion 123. The power unit P is supported by the center frame 13 vertically swingably through a pivot 15. The center frame 13 is an aluminum cast frame and is connected to a rear end of the front frame 12. The rear frame 14, which extends backwardly upward, is constituted of an annular pipe, with a fuel tank 16 being supported on an upper surface of the rear frame 14 . A helmet case 17 is supported on an upper surface of the center frame 13. The helmet case 17 and the fuel tank 16 are covered so that they can be opened and closed with a cover 19 which has a seat integrally. [0013] The power unit P comprises a water-cooled type single cylinder 4-cycle engine E disposed toward the vehicular front side and a belt type continuously variable transmission T extending from the left side of the engine E toward the back of the vehicle body, the engine E and the transmission T being coupled together integrally. An upper surface of a rear portion of the belt type continuously variable transmission T is connected to a rear end of the center frame 13 via a rear cushion 20. An air cleaner 21 is supported on an upper surface of the transmission T, and muffler 22 is supported on the right-hand side of the transmission T. Further, a main stand 23 capable of standing up and falling down is supported on - a lower surface of the engine E. [0014] As shown in Figs. 3 and 4, the engine E is provided with a first engine block 32 and a second engine block 33 which are divided from each other by a parting face 30 extending vertically along a crank shaft 31. The first engine block 32 constitutes a cylinder block 321 and a crank case half 322, while the second engine block 33 constitutes the other half of the crank case. A cylinder head 34 is connected to a front end of the first engine block 32, and a head cover 35 is connected to a front end of the cylinder head 34 . A generator cover 36 is connected to the right side faces of the first and second engine blocks 32, 33. [0015] The belt type continuously variable transmission T is provided with a right-hand casing 37 and a left-hand casing 38 which are coupled together. The right side face of a front portion of the right-hand casing 37 is connected to the left side face of the first and second engine blocks 32, 33. Further, a reduction mechanism casing 39 is connected to the right side face of a rear portion of the right-hand casing 37 . [0016] The first engine block 32 is provided with a cylinder 41, into which is fitted a piston 42 capable of sliding. The piston 42 is connected to the crank shaft 31 via a connecting rod 43. A cam shaft 44 is supported rotatably in the cylinder head 34, and take and exhaust valves (not shown) provided in the cylinder head 34 are operated for opening and closing motions by the cam shaft 44. A timing chain 45 is received in a chain passage 40 formed in the first engine block 32 and it is entrained on both a driving sprocket 46 mounted on the crank shaft 31 and a driven sprocket 47 mounted on the cam shaft 44. In this configuration, the camshaft 44 rotates once each time the crank shaft 31 rotates twice. [0017] A driving pulley 54 is mounted on a left end of the crank shaft 31 which projects into the right- and left-hand casings 37, 38. The driving pulley 54 is provided with a stationary pulley half 55 fixed to the crank shaft 31 and a movable pulley half 56 capable of moving toward and away from the stationary pulley half 55. The movable pulley half 56 is urged toward the stationary pulley half 55 by virtue of a centrifugal weight 57 which moves radially outwards in response to an increase in the number of revolutions of the crank shaft 31. [0018] A driven pulley 59 on an output shaft 58 supported between the rear portion of the right-hand casing 37 and the reduction mechanism casing 39 is provided with a stationary pulley half 60 supported relatively rotatably with respect to the output shaft 58 and a movable pulley half 61 capable moving toward and away from the stationary pulley half 60. The movable pulley half 61 is urged toward the stationary pulley half 60 by means of a spring 62. A starting clutch 63 is provided between the stationary pulley half 60 and the output shaft 58. Further, an endless V belt 64 is entrained on both the driving pulley 54 and the driven pulley 59. [0019] An intermediate shaft 65 and an axle 66 both parallel to the output shaft 58 are supported between the right-hand casing 37 and the reduction mechanism casing 39, and a reduction gear train 67 is mounted among the output shaft 58, intermediate shaft 65 and axle 66. Further, the rear wheel Wr is mounted on a right-hand end of the axle 66 which projects rightwards through the reduction mechanism casing 39. [0020] A rotational power of the crank shaft 31 is transmitted to the driving pulley 54 , from which it is further transmitted to the rear wheel Wr via the V belt 64, driven pulley 59, starting clutch 63, and reduction gear train 67. [0021] When the engine E rotates at a low speed, the centrifugal force acting on the centrifugal weight 57 of the driving pulley is small, so that the groove width between the stationary pulley half 60 and the movable pulley half 61 is decreased by the spring 62 on the driven pulley 59, and the change gear ratio is LOW. As the number of revolutions of the crank shaft 31 increases in this state, the centrifugal force acting on the centrifugal weight 57 increases and the groove width between the stationary pulley half 55 and the movable pulley half 56 of the driving pulley 54 decreases, with consequent increase in the groove width between the stationary pulley half 60 and the movable pulley half 61 of the driven pulley 59. Therefore, the change gear ratio varies continuously from LOW to TOP. [0022] An AC generator 68, which is disposed on the right-hand side of the crank shaft 31, is covered with the generator cover 36, and a radiator 69 as an object to be cooled is disposed on the right-hand side of the generator cover 36 Between the AC generator 68 and the radiator 69 is disposed a cooling fan 70 which is fixed to a right-hand end of the crank shaft 31. A thermostat case 72 with a thermostat 71 incorporated therein is connected to the right side face of the cylinder head 34, and a cooling water pump 73, which is mounted on a right-hand end of the cam shaft 44, is received in a space surrounded by the cylinder head 34 and the thermostat case 72. [0023] As is apparent from Fig. 4, a front lower portion of the radiator 69 and the thermostat case 72 are connected together through a cooling water pipe 74, and the thermostat case 72 and the first engine block 32 are connected together through a cooling water pipe 75. Further, a water pouring pipe 77, which is connected to a rear upper portion of the radiator 69, is secured removably to a rear fender 76 which covers the rear wheel Wr from above. The water pouring pipe 77 and the cylinder head 34 are connected together through a cooling water pipe 78. [0024] In a completed state of warming-up of the engine E, the cooling water discharged from the cooling water pump 73 which is driven by the cam shaft 44 is fed to a water jacket formed in the first engine block 32 and cylinder head 34 through the thermostat case 72 and cooling water pipe 75. The cooling water cools the engine E while passing through the water jacket and is thereafter fed to the radiator 69 through the cooling water pipe 78. The cooling water whose temperature has dropped during passage through the radiator 69 is returned to the cooling water pump 73 through the cooling water pipe 74 and the thermostat 71. On the other hand, when the cooling water temperature is low during warming-up of the engine E, the thermostat 71 operates and the cooling water circulates through the interior of the engine E without passing through the radiator, so that the temperature thereof rises quickly. [0025] Referring also to Figs. 5 to 8, the cooling fan 70 fixed onto the crank shaft 31 and the radiator 69 disposed outside the cooling fan are covered with a synthetic resin cover 80 which is secured to the generator cover 36. The cover 80 is disposed at the most projecting position on the right-hand side of the scooter type motorcycle and a bank angle a to the right-hand side of the motorcycle is restricted by the cover 80 . Therefore, a lower side wall 80a of the cover 80 is inclined upwardly outwards. A lower portion 69a of the radiator 69 is also inclined correspondingly to the lower side wall 80a. [0026] For uniforming the flow of cooling air to be introduced into the cover 80, for suppressing leakage to the exterior of a noise generated in the cover 80, and for preventing the entry of a foreign matter into the cover, a louver 81 which introduces cooling air from the exterior to the radiator 69 is provided in the cover- The louver 81 comprises a plurality of fins 84 which are integral with the cover 80 and which divide a cooling air intake port 82 into a plurality of air flow passages 83, the cooling air intake port 82 being formed in the cover 80 so as to be open toward the radiator 69. [0027] The cooling air intake port 82 is formed in an elliptic shape which is long in the longitudinal direction of the motorcycle for obtaining the foregoing bank angle a . The cooling air intake port 82 is disposed at a position offset to the upper portion side of the cover,80 so that a center line C of the cooling air intake port lies above the axis of the crank shaft 31. [0028] The fins 84 are formed in the cooling air intake port 82 so as to extend long in the longitudinal direction of the motorcycle and at nearly equal intervals in the vertical direction. Besides, the fins 84 are formed in such a manner that a straight line L connecting between an outer end center and an inner end center of an air flow passage formed between adjacent fins 84 is inclined relative to the center line C of the cooling air intake port 82. In this embodiment, the straight line L is inclined relative to the center line C so that the outer end center of each air flow passage 83 lies below the inner end center of the same passage. [0029] The fins 84 each comprise a main fin portion 84a which extends inclinedly relative to the center line C of the cooling air intake port 82 and whose outer end is flush with and contiguous to an outer-end peripheral edge portion of the cooling air intake port (82) and a proj ecting portion 84b which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion 84a and which projects toward the fin 84 adjacent thereto Since each fin 84 has such a shape, the spacing between the outer ends of adjacent fins 84 becomes narrower than the spacing between the inner ends of adjacent fins 84. [0030] The fins 84 are integrally connected together through a plurality of reinforcing portions 85 extending vertically. An outer end position of the reinforcing portions 85 is set equal to an inner surface position of the projecting portion 84b. [0031] The air introduced into the cover 80 from the louver 81 is sucked by the cooling fan 70 and passes through the radiator 69 to cool the cooling water present in the radiator, then is discharged to the exterior from an air discharge port 86 formed below the cover 80. [0032] As shown clearly in Fig. 5, the cooling fan 70 is fixed onto an end portion of the crank shaft 31 extending through a through hole 87 which is formed in an end wall 36a of the generator cover 36. An annular clearance communicating with the interior of the cover 80 is formed between an inner surface of the through hole 87 and an outer surface of the crank shaft 31. Therefore, when a negative pressure is developed between the cooling fan 70 and the end wall 36a while the cooling fan is in operation, a negative pressure is developed also in the generator cover 36, so the entry of dust or water is likely to occur through the joined interface between the first and second engine blocks 32, 33 . In view of this point the cooling fan 70 is formed so as to be opposed to the end wall 36a of the generator cover 36 over a relatively long distance, thereby minimizing the development of a negative pressure in the clearance 88 between the cooling fan 70 and the end wall 36a. [0033] In Fig. 9, a mold assembly for molding the cover 80 according to the present invention is provided with first and second molds 91, 92 capable of moving toward and away from each other. The first mold 91 is provided with a first molding portion 91a for forming an outer side face and an outer end face of the main fin portion 84a of each fin 84 and also for forming an outer surface and a front end face of the projecting portion 84b. The second mold 92 is provided with a second molding portion 92a for forming an inner side face and an inner end face of the main fin portion 84a and also for forming an inner surface of the projecting portion 84b. [0034] The operation of this embodiment will now be described. The plural fins 84 which constitute the louver 81 of the cover 80 are formed in a shape such that the spacing between outer ends of adjacent fins 84 is narrower than the spacing between inner ends of adjacent fins 84. Thus, by setting the spacing between the outer ends of adjacent fins 84 relatively narrow it is possible to effectively prevent the entry of a foreign matter into the cover 80. Besides, since the spacing between the inner ends of adjacent fins 84 is relatively wide, the flow area of each air flow passage 83 formed between adjacent fins 84 does not become small throughout the overall length of the air flow passage 83 although it becomes small partially on the outer end side of each fin 84, and cooling air can be introduced smoothly into the cover 80 while its flow is uniformed by each air flow passage 83 and while avoiding a great increase in flow resistance of the cooling air flowing through the air flow passage, thus making it possible to cool the radiator 69 effectively. [0035] Moreover, the fins 84 each comprise the main fin portion 84 extending inclinedly relative to the center line C of the cooling air intake port 82 and whose outer end is flush with and contiguous to the outer.end peripheral edge portion of the cooling air intake port 82 and the projecting portion 84b which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion 84 and which projects toward the fin 84 adjacent thereto. The spacing between the outer ends of adjacent fins 84 is made narrower than the spacing between the inner ends of adjacent fins by merely partially increasing the wall thickness on the outer end side of each fin 84. Therefore, it is possible to avoid a great increase in weight of the fins 84, or the cover 80. [0036] Besides, since each fin 84 is inclined outwardly downwards in the cover 80 which is disposed in the lower portion of the motorcycle, it is possible to hide the interior of the cover 80 surely from the eyes of a person present on the right-hand side of the motorcycle and thus possible to improve the commercial value of the cover. [0037] Further, the mold assembly for molding the cover 80 comprises the first mold 91 having the first molding portion 91a for forming the outer side face and outer end face of the main fin portion 84a and also for forming the outer surface and front end face of the projecting portion 84b and the second mold 92 having the second molding portion 92a for forming the inner side face and inner end face of the main fin portion 84a and also for forming the inner surface of the projecting portion 84b. The parting face of the first and second molds 91, 92 is set inside the outer end position of each fin 84 to prevent the formation of burr or a sharp edge at the outer end portion of the fin 84, thereby making it possible to improve the appearance and commercial value of the cover 80. [0038) Further, since the inner surface of the projecting portion 84b is formed by the front end of the second molding portion 92a of the second mold 92, it is possible to narrow the spacing between adjacent fins 84 while ensuring a front end width W2 of the second molding portion 92a and a front end width Wl of the first molding portion 91a. Also in this case it is possible to improve the commercial value of the cover 80. [0039] Although an embodiment of the present invention has been described above in detail, the present invention is not limited to the above embodiment, but various design modifications may be made without departing from the scope of the invention described in the claims. [0040] For example, although in the above embodiment the present invention is applied to the cover 80 which covers the radiator 69, the invention is applicable widely to louvers provided in covers which cover objects to be cooled. [0041] (Effect of the Invention] As set forth above, according to the invention according to claim 1, not only the entry of a foreign matter into the cover can be prevented effectively, but also cooling air can be introduced smoothly into the cover while uniforming the flow of cooling air in each air flow passage and while avoiding a great increase in flow resistance of the cooling air flow through each air flow passage. [0042] According to the invention according to claim 2, the fin shape recited in claim 2 can be obtained merely by partially increasing the wall thickness on the outer end side of each fin, thus making it possible to avoid a great increase in weight of the fins, or the cover. [0043] Further, according to the invention according to claim 3, by setting the parking face of the first and second molds inside the outer end position of each fin, it is possible to prevent the formation of burr and a sharp edge at the outer end portion of each fin and thereby improve the appearance and commercial value of the cover. Since the inner surface of the projecting portion of each fin is formed by the front end of the second molding portion of the second mold, it is possible to narrow the spacing between adjacent fins while ensuring the front end widths of the first and second molding portion and hence also possible to improve the commercial value of the cover. [Explanation of Reference Numerals) 69 . . . radiator as an object to be cooled 80 . . . cover 81 . . . louver 82 ... cooling air intake port 83 ... air flow passage 84 ... fin 84a . . . main fin portion 84b . . . projecting portion 91 . . . first mold 91a . . . first molding portion 92 . . . second mold 92a . . . second molding portion C ... center line L ... straight line We claim: 1. A louver of a cover, having a plurality of fins (84) which divide a cooling air inlet port (82) into a plurality of air flow passages (83), said fins (84) being provided in the cover (80) in an arrangement such that a straight line (L) connecting between an outer end center and an inner end center of each said air flow passage (83) is inclined relative to a center line (C) of said air intake port (82), said cover (80) having said cooling air intake port (82) and covering an object (69) to be cooled, said cooling air intake port (82) being open toward the object (69) to be cooled, characterized in that said fins (84) are formed in a shape such that the spacing between outer ends of adjacent said fins (84) is narrower than the spacing between inner ends of adjacent said fins (84). 2. A louver of a cover as claimed in claim 1, wherein said fins (84) are formed of a synthetic resin and integral with the cover (80) and each comprise a main fin portion (84a) which extends inclinedly relative to the center line (C) of the cooling air intake port (82) and whose outer end is flush with and contiguous to an outer-end peripheral edge portion of the cooling air intake port (82) and a projecting portion (84b) which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion (84a) and which projects toward the fin (84) adjacent thereto. 3. A louver of a cover substantially as hereinbefore described with reference to and illustrated in the accompanying drawings. Dated this the 12th day of April, 2000 (RANJNA MEHTA-DUTT) OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANTS

Full Text

FORM 2
THE PATENTS ACT, 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See Section 10; rule 13]
"A LOUVER OF A COVER"
HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan
The following specification particularly describes the nature of the invention and the manner in which it is to be performed:-

ORIGINAL
348/MUM/2000

GRANTED
25-4-2005

[Detailed Description of the Invention]
[0001]
[Technical Field of the Invention]
The present invention relates to an improvement of a louver of a cover which covers an object to be cooled, as well as an improvement of a mold assembly for molding a cover of a synthetic resin having the louver.
[0002]
[Prior Art]
A cover which covers a heat radiating portion of an engine mounted on a motorcycle and which is provided with a louver, is disclosed in Japanese Registered Utility Model Application No. 2573000. [0003] [Problem to be Solved by the Invention]
The louver is for uniforming the flow of cooling air into a cover, for suppressing leak to the exterior of a noise

generated in the cover, and for preventing the entry of a foreign matter into the cover. In the above conventional louver, in order to attain such effects, a plurality of fins are provided in the cover so as to be arranged within a cooling air intake port and so as to be inclined rectilinearly in an air flowing direction of an air flow passage formed between adjacent fins. [0004]
For effectively preventing the entry of a foreign matter into the cover it is desirable that the spacing between outer ends of adjacent fins be narrow. In the above conventional louver, however, if the spacing between outer ends of adjacent fins is set narrow, the flow area of an air flow passage between adjacent fins becomes smaller throughout the overall length in the air flowing direction, so that the flow resistance of cooling air flowing through the air flow passage becomes large. [0005]
The present invention has been accomplished in view of the above-mentioned circumstances and it is an object of the invention to provide a louver of a cover capable of effectively preventing the entry of a foreign matter into the cover and capable of introducing cooling air smoothly into the cover [0006] [Means for Solving the Problem]
For achieving the above-mentioned object, according to the invention according to claim 1 there is provided a louver of a cover, having a plurality of fins which divide a cooling

air inlet port into a plurality of air flow passages, the fins being provided in the cover in an arrangement such that a straight line connecting between an outer end center and an inner end center of each air flow passage is inclined relative to a center line of the air intake port, the cover having the cooling air intake port and covering an object to be cooled, the cooling air intake port being open toward the object to be cooled, characterized in that the fins are formed in a shape such that the spacing between outer ends of adjacent fins is narrower than the spacing between inner ends of adjacent fins. [0007]
According to this configuration, the entry of a foreign matter into the cover can be prevented effectively by setting the spacing between outer ends of adjacent fins relatively narrow. Besides, since the spacing between inner ends of adjacent fins is relatively wide, the flow area of the air flow passage between adjacent fins does not become small throughout the overall length of each air flow passage although it becomes small in part of the outer end side of each fin, whereby cooling air can be introduced smoothly into the cover while uniforming its flow in each air flow passage and while preventing a great increase in flow resistance of the cooling air. [0008]
According to the invention according to claim 2, in combination with the invention according to claim 1, there is provided a louver of a cover wherein the fins are formed

of a synthetic resin and integral with the cover and each comprise a main fin portion which extends inclinedly relative to the center line of the cooling air intake port and whose outer end is flush with and contiguous to an outer-end peripheral edge portion of the cooling air intake port and a projecting portion which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion and which projects toward the fin adjacent thereto. According to this configuration, by merely increasing the wall thickness on the outer end side of each fin partially it is possible to obtain the fin shape described in claim 1 and hence possible to prevent a partial increase in weight of the fins, or the covers. [0009]
According to the invention according to claim 3 there is provided a mold assembly for molding the cover having the louver described in claim 2, comprising a first mold having a first molding portion for forming an outer side face and an outer end face of the main fin portion and an outer surface and a tip end face of the projecting portion and a second mold having a second molding portion for forming an inner side face and an inner end face of the main fin portion and an inner surface of the projecting portion. According to this mold assembly, by setting a parting face of the first and second molds inwards relative to the outer end position of the fins, it is possible to prevent the formation of burr or a sharp edge at the outer end portion of each fin and thereby improve

the appearance and commercial value of the cover. Further, by forming an inner surface of the projecting portion at the front end of the second molding portion of the second mold, the spacing between adjacent fins can be narrowed while ensuring a required front end width of each of the first and second molding portions, thus also permitting the improvement in the commercial value of the cover.
[Mode for carrying out the Invention]
A mode for carrying out the invention will be described below by way of an embodiment thereof illustrated in the accompanying drawings,
Accordingly, the present invention relates to a louver of a cover, having a plurality of fins which divide a cooling air inlet port into a plurality of air flow passages, said fins being provided in the cover in an arrangement such that a straight line (L) connecting between an outer end center and an inner end center of each said air flow passage is inclined relative to a center line (C) of said air intake port, said cover having said cooling air intake port and covering an object to be cooled, said cooling air intake port being open toward the object to be cooled, characterized in that said fins are formed in a shape such that the spacing between outer ends of adjacent said fins is narrower than the spacing between inner ends of adjacent said fins.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 is an entire side view of a scooter type motorcycle;
Fig. 2 is an enlarged view of a principal portion of Fig. 1;
Fig. 3 is a sectional view taken on line 3-3 in Fig. 2;
Fig. 4 is a view as seen in the arrowed direction 4-4 in Fig. 3;
Fig. 5 is a sectional view taken on line 5-5 in Fig. 4;
Fig. 6 is a side view of a cover;
Fig. 7 is a sectional view taken on line 7-7 in Fig. 6;
Fig. 8 is a sectional view taken on line 8-8 in Fig. 6; and
Fig. 9 is a sectional view showing a part of a mold assembly.

[0011]
Figs. 1 to 9 illustrate an embodiment of the present invention, of which Fig. 1 is an entire side view of a scooter type motorcycle, Fig. 2 is an enlarged view of a principal portion of Fig. 1, Fig. 3 is a sectional view taken on line 3-3 in Fig. 2, Fig. 4 is a view as seen in the arrowed direction 4-4 in Fig. 3, Fig. 5 is a sectional view taken on line 5-5 in Fig. 4, Fig. 6 is a side view of a cover, Fig. 7 is a sectional view taken on line 7-7 in Fig. 6, Fig. 8 is a sectional view taken on line 8-8 in Fig. 6, and Fig. 9 is a sectional view showing a part of a mold assembly. [0012]
First in Figs. 1 and 2, in a scooter type motorcycle V provided with a front wheel wf which is steered by a steering handle 11 and a rear wheel wr which is driven by a swing type

power unit P, a body frame F is divided into three, that is, a front frame 12, a center frame 13, and a rear frame 14. The front frame 12 is an aluminum alloy cast frame integrally provided with a head pipe 121, a down tube 122, and a step floor support portion 123. The power unit P is supported by the center frame 13 vertically swingably through a pivot 15. The center frame 13 is an aluminum cast frame and is connected to a rear end of the front frame 12. The rear frame 14, which extends backwardly upward, is constituted of an annular pipe, with a fuel tank 16 being supported on an upper surface of the rear frame 14 . A helmet case 17 is supported on an upper surface of the center frame 13. The helmet case 17 and the fuel tank 16 are covered so that they can be opened and closed with a cover 19 which has a seat integrally. [0013]
The power unit P comprises a water-cooled type single cylinder 4-cycle engine E disposed toward the vehicular front side and a belt type continuously variable transmission T extending from the left side of the engine E toward the back of the vehicle body, the engine E and the transmission T being coupled together integrally. An upper surface of a rear portion of the belt type continuously variable transmission T is connected to a rear end of the center frame 13 via a rear cushion 20. An air cleaner 21 is supported on an upper surface of the transmission T, and muffler 22 is supported on the right-hand side of the transmission T. Further, a main stand 23 capable of standing up and falling down is supported on

- a lower surface of the engine E. [0014]
As shown in Figs. 3 and 4, the engine E is provided with a first engine block 32 and a second engine block 33 which are divided from each other by a parting face 30 extending vertically along a crank shaft 31. The first engine block 32 constitutes a cylinder block 321 and a crank case half 322, while the second engine block 33 constitutes the other half of the crank case. A cylinder head 34 is connected to a front end of the first engine block 32, and a head cover 35 is connected to a front end of the cylinder head 34 . A generator cover 36 is connected to the right side faces of the first and second engine blocks 32, 33. [0015]
The belt type continuously variable transmission T is provided with a right-hand casing 37 and a left-hand casing 38 which are coupled together. The right side face of a front portion of the right-hand casing 37 is connected to the left side face of the first and second engine blocks 32, 33. Further, a reduction mechanism casing 39 is connected to the right side face of a rear portion of the right-hand casing 37 . [0016]
The first engine block 32 is provided with a cylinder 41, into which is fitted a piston 42 capable of sliding. The piston 42 is connected to the crank shaft 31 via a connecting rod 43. A cam shaft 44 is supported rotatably in the cylinder

head 34, and take and exhaust valves (not shown) provided in the cylinder head 34 are operated for opening and closing motions by the cam shaft 44. A timing chain 45 is received in a chain passage 40 formed in the first engine block 32 and it is entrained on both a driving sprocket 46 mounted on the crank shaft 31 and a driven sprocket 47 mounted on the cam shaft 44. In this configuration, the camshaft 44 rotates once each time the crank shaft 31 rotates twice. [0017]
A driving pulley 54 is mounted on a left end of the crank shaft 31 which projects into the right- and left-hand casings 37, 38. The driving pulley 54 is provided with a stationary pulley half 55 fixed to the crank shaft 31 and a movable pulley half 56 capable of moving toward and away from the stationary pulley half 55. The movable pulley half 56 is urged toward the stationary pulley half 55 by virtue of a centrifugal weight 57 which moves radially outwards in response to an increase in the number of revolutions of the crank shaft 31. [0018]
A driven pulley 59 on an output shaft 58 supported between the rear portion of the right-hand casing 37 and the reduction mechanism casing 39 is provided with a stationary pulley half 60 supported relatively rotatably with respect to the output shaft 58 and a movable pulley half 61 capable moving toward and away from the stationary pulley half 60. The movable pulley half 61 is urged toward the stationary pulley half 60 by means of a spring 62. A starting clutch 63 is provided

between the stationary pulley half 60 and the output shaft 58. Further, an endless V belt 64 is entrained on both the driving pulley 54 and the driven pulley 59. [0019]
An intermediate shaft 65 and an axle 66 both parallel to the output shaft 58 are supported between the right-hand casing 37 and the reduction mechanism casing 39, and a reduction gear train 67 is mounted among the output shaft 58, intermediate shaft 65 and axle 66. Further, the rear wheel Wr is mounted on a right-hand end of the axle 66 which projects rightwards through the reduction mechanism casing 39. [0020]
A rotational power of the crank shaft 31 is transmitted to the driving pulley 54 , from which it is further transmitted to the rear wheel Wr via the V belt 64, driven pulley 59, starting clutch 63, and reduction gear train 67. [0021]
When the engine E rotates at a low speed, the centrifugal force acting on the centrifugal weight 57 of the driving pulley is small, so that the groove width between the stationary pulley half 60 and the movable pulley half 61 is decreased by the spring 62 on the driven pulley 59, and the change gear ratio is LOW. As the number of revolutions of the crank shaft 31 increases in this state, the centrifugal force acting on the centrifugal weight 57 increases and the groove width between the stationary pulley half 55 and the movable pulley half 56 of the driving pulley 54 decreases, with consequent

increase in the groove width between the stationary pulley half 60 and the movable pulley half 61 of the driven pulley 59. Therefore, the change gear ratio varies continuously from LOW to TOP. [0022]
An AC generator 68, which is disposed on the right-hand side of the crank shaft 31, is covered with the generator cover 36, and a radiator 69 as an object to be cooled is disposed on the right-hand side of the generator cover 36 Between the AC generator 68 and the radiator 69 is disposed a cooling fan 70 which is fixed to a right-hand end of the crank shaft 31. A thermostat case 72 with a thermostat 71 incorporated therein is connected to the right side face of the cylinder head 34, and a cooling water pump 73, which is mounted on a right-hand end of the cam shaft 44, is received in a space surrounded by the cylinder head 34 and the thermostat case 72. [0023]
As is apparent from Fig. 4, a front lower portion of the radiator 69 and the thermostat case 72 are connected together through a cooling water pipe 74, and the thermostat case 72 and the first engine block 32 are connected together through a cooling water pipe 75. Further, a water pouring pipe 77, which is connected to a rear upper portion of the radiator 69, is secured removably to a rear fender 76 which covers the rear wheel Wr from above. The water pouring pipe 77 and the cylinder head 34 are connected together through a cooling water pipe 78.

[0024]
In a completed state of warming-up of the engine E, the cooling water discharged from the cooling water pump 73 which is driven by the cam shaft 44 is fed to a water jacket formed in the first engine block 32 and cylinder head 34 through the thermostat case 72 and cooling water pipe 75. The cooling water cools the engine E while passing through the water jacket and is thereafter fed to the radiator 69 through the cooling water pipe 78. The cooling water whose temperature has dropped during passage through the radiator 69 is returned to the cooling water pump 73 through the cooling water pipe 74 and the thermostat 71. On the other hand, when the cooling water temperature is low during warming-up of the engine E, the thermostat 71 operates and the cooling water circulates through the interior of the engine E without passing through the radiator, so that the temperature thereof rises quickly. [0025]
Referring also to Figs. 5 to 8, the cooling fan 70 fixed onto the crank shaft 31 and the radiator 69 disposed outside the cooling fan are covered with a synthetic resin cover 80 which is secured to the generator cover 36. The cover 80 is disposed at the most projecting position on the right-hand side of the scooter type motorcycle and a bank angle a to the right-hand side of the motorcycle is restricted by the cover 80 .
Therefore, a lower side wall 80a of the cover 80 is inclined upwardly outwards. A lower portion 69a of the radiator 69 is

also inclined correspondingly to the lower side wall 80a. [0026]
For uniforming the flow of cooling air to be introduced into the cover 80, for suppressing leakage to the exterior of a noise generated in the cover 80, and for preventing the entry of a foreign matter into the cover, a louver 81 which introduces cooling air from the exterior to the radiator 69 is provided in the cover- The louver 81 comprises a plurality of fins 84 which are integral with the cover 80 and which divide a cooling air intake port 82 into a plurality of air flow passages 83, the cooling air intake port 82 being formed in the cover 80 so as to be open toward the radiator 69. [0027]
The cooling air intake port 82 is formed in an elliptic shape which is long in the longitudinal direction of the
motorcycle for obtaining the foregoing bank angle a . The cooling air intake port 82 is disposed at a position offset to the upper portion side of the cover,80 so that a center line C of the cooling air intake port lies above the axis of the crank shaft 31. [0028]
The fins 84 are formed in the cooling air intake port 82 so as to extend long in the longitudinal direction of the motorcycle and at nearly equal intervals in the vertical direction. Besides, the fins 84 are formed in such a manner that a straight line L connecting between an outer end center and an inner end center of an air flow passage formed between

adjacent fins 84 is inclined relative to the center line C of the cooling air intake port 82. In this embodiment, the straight line L is inclined relative to the center line C so that the outer end center of each air flow passage 83 lies below the inner end center of the same passage. [0029]
The fins 84 each comprise a main fin portion 84a which extends inclinedly relative to the center line C of the cooling air intake port 82 and whose outer end is flush with and contiguous to an outer-end peripheral edge portion of the cooling air intake port (82) and a proj ecting portion 84b which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion 84a and which projects toward the fin 84 adjacent thereto Since each fin 84 has such a shape, the spacing between the outer ends of adjacent fins 84 becomes narrower than the spacing between the inner ends of adjacent fins 84. [0030]
The fins 84 are integrally connected together through a plurality of reinforcing portions 85 extending vertically. An outer end position of the reinforcing portions 85 is set equal to an inner surface position of the projecting portion 84b. [0031]
The air introduced into the cover 80 from the louver 81 is sucked by the cooling fan 70 and passes through the radiator 69 to cool the cooling water present in the radiator, then

is discharged to the exterior from an air discharge port 86
formed below the cover 80.
[0032]
As shown clearly in Fig. 5, the cooling fan 70 is fixed onto an end portion of the crank shaft 31 extending through a through hole 87 which is formed in an end wall 36a of the generator cover 36. An annular clearance communicating with the interior of the cover 80 is formed between an inner surface of the through hole 87 and an outer surface of the crank shaft 31. Therefore, when a negative pressure is developed between the cooling fan 70 and the end wall 36a while the cooling fan is in operation, a negative pressure is developed also in the generator cover 36, so the entry of dust or water is likely to occur through the joined interface between the first and second engine blocks 32, 33 . In view of this point the cooling fan 70 is formed so as to be opposed to the end wall 36a of the generator cover 36 over a relatively long distance, thereby minimizing the development of a negative pressure in the clearance 88 between the cooling fan 70 and the end wall 36a. [0033]
In Fig. 9, a mold assembly for molding the cover 80 according to the present invention is provided with first and second molds 91, 92 capable of moving toward and away from each other. The first mold 91 is provided with a first molding portion 91a for forming an outer side face and an outer end face of the main fin portion 84a of each fin 84 and also for

forming an outer surface and a front end face of the projecting portion 84b. The second mold 92 is provided with a second molding portion 92a for forming an inner side face and an inner end face of the main fin portion 84a and also for forming an inner surface of the projecting portion 84b. [0034]
The operation of this embodiment will now be described. The plural fins 84 which constitute the louver 81 of the cover 80 are formed in a shape such that the spacing between outer ends of adjacent fins 84 is narrower than the spacing between inner ends of adjacent fins 84. Thus, by setting the spacing between the outer ends of adjacent fins 84 relatively narrow it is possible to effectively prevent the entry of a foreign matter into the cover 80. Besides, since the spacing between the inner ends of adjacent fins 84 is relatively wide, the flow area of each air flow passage 83 formed between adjacent fins 84 does not become small throughout the overall length of the air flow passage 83 although it becomes small partially on the outer end side of each fin 84, and cooling air can be introduced smoothly into the cover 80 while its flow is uniformed by each air flow passage 83 and while avoiding a great increase in flow resistance of the cooling air flowing through the air flow passage, thus making it possible to cool the radiator 69 effectively. [0035]
Moreover, the fins 84 each comprise the main fin portion 84 extending inclinedly relative to the center line C of the

cooling air intake port 82 and whose outer end is flush with and contiguous to the outer.end peripheral edge portion of the cooling air intake port 82 and the projecting portion 84b which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion 84 and which projects toward the fin 84 adjacent thereto. The spacing between the outer ends of adjacent fins 84 is made narrower than the spacing between the inner ends of adjacent fins by merely partially increasing the wall thickness on the outer end side of each fin 84. Therefore, it is possible to avoid a great increase in weight of the fins 84, or the cover 80. [0036]
Besides, since each fin 84 is inclined outwardly downwards in the cover 80 which is disposed in the lower portion of the motorcycle, it is possible to hide the interior of the cover 80 surely from the eyes of a person present on the right-hand side of the motorcycle and thus possible to improve the commercial value of the cover. [0037]
Further, the mold assembly for molding the cover 80 comprises the first mold 91 having the first molding portion 91a for forming the outer side face and outer end face of the main fin portion 84a and also for forming the outer surface and front end face of the projecting portion 84b and the second mold 92 having the second molding portion 92a for forming the inner side face and inner end face of the main fin portion 84a and also for forming the inner surface of the projecting

portion 84b. The parting face of the first and second molds 91, 92 is set inside the outer end position of each fin 84 to prevent the formation of burr or a sharp edge at the outer end portion of the fin 84, thereby making it possible to improve the appearance and commercial value of the cover 80. [0038)
Further, since the inner surface of the projecting portion 84b is formed by the front end of the second molding portion 92a of the second mold 92, it is possible to narrow the spacing between adjacent fins 84 while ensuring a front end width W2 of the second molding portion 92a and a front end width Wl of the first molding portion 91a. Also in this case it is possible to improve the commercial value of the cover 80. [0039]
Although an embodiment of the present invention has been described above in detail, the present invention is not limited to the above embodiment, but various design modifications may be made without departing from the scope of the invention described in the claims. [0040]
For example, although in the above embodiment the present invention is applied to the cover 80 which covers the radiator 69, the invention is applicable widely to louvers provided in covers which cover objects to be cooled. [0041] (Effect of the Invention]

As set forth above, according to the invention according to claim 1, not only the entry of a foreign matter into the cover can be prevented effectively, but also cooling air can be introduced smoothly into the cover while uniforming the flow of cooling air in each air flow passage and while avoiding a great increase in flow resistance of the cooling air flow through each air flow passage. [0042]
According to the invention according to claim 2, the fin shape recited in claim 2 can be obtained merely by partially increasing the wall thickness on the outer end side of each fin, thus making it possible to avoid a great increase in weight of the fins, or the cover. [0043]
Further, according to the invention according to claim 3, by setting the parking face of the first and second molds inside the outer end position of each fin, it is possible to prevent the formation of burr and a sharp edge at the outer end portion of each fin and thereby improve the appearance and commercial value of the cover. Since the inner surface of the projecting portion of each fin is formed by the front end of the second molding portion of the second mold, it is possible to narrow the spacing between adjacent fins while ensuring the front end widths of the first and second molding portion and hence also possible to improve the commercial value of the cover.

[Explanation of Reference Numerals)
69 . . . radiator as an object to be cooled 80 . . . cover 81 . . . louver 82 ... cooling air intake port 83 ... air flow passage 84 ... fin 84a . . . main fin portion 84b . . . projecting portion 91 . . . first mold 91a . . . first molding portion 92 . . . second mold 92a . . . second molding portion C ... center line L ... straight line

We claim:
1. A louver of a cover, having a plurality of fins (84) which divide a cooling
air inlet port (82) into a plurality of air flow passages (83), said fins (84)
being provided in the cover (80) in an arrangement such that a straight
line (L) connecting between an outer end center and an inner end center
of each said air flow passage (83) is inclined relative
to a center line (C) of said air intake port (82), said cover (80) having said cooling air intake port (82) and covering an object (69) to be cooled, said cooling air intake port (82) being open toward the object (69) to be cooled, characterized in that said fins (84) are formed in a shape such that the spacing between outer ends of adjacent said fins (84) is narrower than the spacing between inner ends of adjacent said fins (84).
2. A louver of a cover as claimed in claim 1, wherein said fins (84) are formed of a synthetic resin and integral with the cover (80) and each comprise a main fin portion (84a) which extends inclinedly relative to the center line (C) of the cooling air intake port (82) and whose outer end is flush with and contiguous to an outer-end peripheral edge portion of the cooling air intake port (82) and a projecting portion (84b) which is flush with and contiguous at an obtuse angle to the outer end of the main fin portion (84a) and which projects toward the fin (84) adjacent thereto.
3. A louver of a cover substantially as hereinbefore described with reference to and illustrated in the accompanying drawings.
Dated this the 12th day of April, 2000
(RANJNA MEHTA-DUTT)
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANTS

Documents:

« Previous Patent

Next Patent »

Patent Number

214059

Indian Patent Application Number

348/MUM/2000

PG Journal Number

13/2008

Publication Date

28-Mar-2008

Grant Date

25-Jan-2008

Date of Filing

12-Apr-2000

Name of Patentee

HONDA GIKEN KOGYO KABUSHIKI KAISHA

Applicant Address

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

Inventors:

#	Inventor's Name	Inventor's Address
1	YOSHITAKA NUKADA	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN

PCT International Classification Number

F01P5/06

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	JEO-11-151422	1999-05-31	Japan