Title of Invention	PLASTIC-METAL COMBINATION AND FUEL INJECTION VALVE WITH A PLASTIC-METAL COMBINATION
Abstract	Abstract PLASTIC-METAL COMBINATION AND FUEL INJECTION VALVE WITH A PLASTIC-METAL COMBINATION The invention relates to a fuel injection valve, especially for fuel injection systems of internal combustion engines. Said valve is characterized by a magnetic circuit comprising a core (2), a solenoid (1), an armature (27), and a mobile valve needle (19) having a valve closing element (21) that interacts with a stationary valve seat (30), said valve seat (30) being formed on a valve seat element (29), and a valve seat support (16) into which the valve seat element (29) is introduced. The outer periphery of at least one metal component of the fuel injection valve has a serrated structure (63a-f) for establishing a solid connection to a corresponding plastic component. The connecting piece (51), the valve seat support (16), the coil body (3) and a connecting tube (23) of the valve needle (19) can be made of plastic. The fuel injection valve is especially suitable for use in fuel injection systems of mixture-compressing spark ignition engines.

Title of Invention

PLASTIC-METAL COMBINATION AND FUEL INJECTION VALVE WITH A PLASTIC-METAL COMBINATION

Abstract

Abstract PLASTIC-METAL COMBINATION AND FUEL INJECTION VALVE WITH A PLASTIC-METAL COMBINATION The invention relates to a fuel injection valve, especially for fuel injection systems of internal combustion engines. Said valve is characterized by a magnetic circuit comprising a core (2), a solenoid (1), an armature (27), and a mobile valve needle (19) having a valve closing element (21) that interacts with a stationary valve seat (30), said valve seat (30) being formed on a valve seat element (29), and a valve seat support (16) into which the valve seat element (29) is introduced. The outer periphery of at least one metal component of the fuel injection valve has a serrated structure (63a-f) for establishing a solid connection to a corresponding plastic component. The connecting piece (51), the valve seat support (16), the coil body (3) and a connecting tube (23) of the valve needle (19) can be made of plastic. The fuel injection valve is especially suitable for use in fuel injection systems of mixture-compressing spark ignition engines.

Full Text	Plastic-metal combination and fuel injection valve with a Plastic-Metal combination State of art of technology The invention emanates from a plastic-metal combination according to generic description of claim 1 and from a fuel injection valve with a plastic-metal combination as per the generic description of claim 8. In figure 1, a known fuel injection valve from the state of art of technology illustrated, which has a classical three-part structure of an inner metallic flow guide part and at the same time housing components. This inner valve tube is formed from a rotating field forming inlet nipple / neck, a non-magnetic intermediate part and a valve seat carrier accepting a valve seating, an axially movable valve needle is provided in the valve seating carrier which includes an anchor and a ball shaped valve closing body as well as a connecting tube jointing the anchor with the valve closing body. The three individual components of the valve needle are firmly jointed with one another with the use of a material to material jointing process, especially welding. Already such a magnetically actuated valve in form of a fuel injection valve is known from patent document DE 40 08 675 A1. The inner valve tube forms the base frame of the entire injection valve and has in its entirety from the three individual components, a significant support function. The non-magnetic intermediate part is jointed through weld seams both leak-proof and firmly with the inlet nipple/neck as well as with the valve seating carrier. The windings of a magnet spool are located in a spool carrier made of plastic, which in turn surrounds in the circumferential direction a part of the inlet nipple serving as the rotating field, and also the intermediate part. An axially movable valve needle is provided in the valve seating carrier, which includes a sleeve / bushing shaped anchor and a ball shaped valve closing body as well as a connecting tube jointing the anchor with the valve closing body. The connecting tube is jointed firmly with the anchor and also with the valve closing body with the use of weld seams. The valve closing body acts in conjunction with a valve seating surface of a metallic valve seating body running in a truncated cone shape. The valve seating body is connected firmly with the valve seating carrier with a weld seam. A further electro-magnetically operated valve in form of a fuel injection valve is known from patent document DE 195 03 224 A1. The fuel injection valve has a ball shaped valve closing body acting in conjunction with the valve seating, which is incorporated on a closing body carrier in the shape of a plastic tube, while at the opposite end of the valve closing body, an anchor is fastened to the plastic tube. These components together form an axially movable valve needle. The bottom end of the plastic tube is designed in a cage-shape, where it is held in the bulged recess of the valve closing body in a positive fit with the use of snap on connection. The plastic tube is designed in the area of the bottom recess spring elastically, because the retainer jaws must overlap the valve closing body. The ball shaped valve closing body can be manufactured from steel, a ceramic or a plastic. The valve closing body works in cooperation with a valve seating surface of a metallic valve seating body running with a truncated cone shape. The valve seating body is connected firmly with the valve seating carrier with the use of weld seam. Advantages of the invention The invention based plastic metal combination with the characteristics of claim 1 has the advantage that they can be easily and cost competitively produced and nevertheless, an automatic assembly is guaranteed. The plastic metal press joints can be securely and reliably produced thereby that in the overlapping areas of the components to be respectively jointed saw-teeth-similar structures are optimally designed at least on the metallic component. The saw teeth-similar structure of the metallic component penetrates into the plastic of the corresponding component and deforms it elastically whereby a relaxation of the plastic happens in the saw teeth similar structure. The invention based design guarantees a high security against loosening of the joints through tightening against the assembly direction, and offers additionally a very high torsion security, which is especially desirable if both the corresponding components must be jointed in a specific rotation position with one another. A tension build¬up during the assembly / mounting is also excluded. Advantageous further designs and improvements of the plastic-metal-combination mentioned under claim 1 are possible through the measures listed under the sub-claims. The invention based fuel injection valve with the characteristic properties of claim 8 has the advantage that a simple and cost-effective manufacture can be realized, and automatic assembly of several individual components and thereby the entire valve is also realizable, since material to material jointing process, such as welding, which has the disadvantage of a heat distortion, and complex positive jointing techniques can be dispensed with. Advantageous press joints between a metallic component partner and a plastic component partner can be especially applied, which are easily, securely and reliably obtainable. The invention based arrangement as also the advantage of a reduction of the solid-borne sound and thereby noise development in contrast to the known solutions. The plastic-metal pressed joint can be securely and reliably manufactured if in the overlapping areas of the components to be jointed, saw teeth similar structures are provided at least on the metallic component. The saw teeth similar structure of the metallic component penetrates into the plastic of the corresponding component, and deforms it elastically where upon a relaxation of the plastic in the saw teeth similar structure is obtained. Advantageous further designs and improvements of the fuel injection valve indicated in the claim 8 are possible through the measures listed in the sub¬claims. It is especially advantageous to produce from a plastic, the connection necks, the valve seating carrier and the valve needle, besides the spool body and the electrical connecting socket, which are then respectively jointed with the metallic components of the fuel injection valve. In this manner, the weight of the fuel injection valve can be reduced. Arising from the reduced weight of these components, the advantage of a better dynamic of the valve and a reduced noise development can also be realized. It is advantageous also to design on the saw teeth similar structure an additional profile area. This profile area is designed as a knurl, which is formed by several parallel, perpendicular or slanted fins, grooves distributed over the circumference. Using this profile area it is advantageous ensured that the metal component is fixed with a positive fit and absolutely torsion proof in the sleeve shaped plastic component. The profile area can be provided on both ends of the saw teeth similar structure of the metallic component. Drawing Design examples of the invention are illustrated in the drawing in a simplified fashion, and explained in the following description. Fig 1 shows a fuel injection valve in a known design as per the state of art of technology. Fig 2 a design example of an invention based fuel injection valve with a number of fixed plastic metal-combinations between two respective components of the fuel injection valve. Fig 3 a first additional design of a plastic-metal combination in a detailed view. Fig 4 a second additional design example of a plastic-metal combination, and Fig 5 a third additional design example of a plastic-metal combination. Description of the design example For a better understanding of the invention, a fuel injection valve is shown in a known design as per the state of art of technology in Figure 1. The electro magnetically actuated valve in form of an injection valve for fuel injection systems of carburetion remote-ignited combustion engines illustrated as an example in figure 1, has a core 2 surrounded by a magnet spool 1 and serving as fuel inlet nipple and rotating field, which for example here is designed in a tube shape, and has over its total length a constant outer diameter. A spool body 3 graduated in radial direction seats a winding / spooling of the magnet spool 1 and facilitates in conjunction with core 2 a contact assembly of the injection valve in the area of the magnet spool 1. A tube shaped metallic non-magnetic intermediate part 12 is connected leak-proof with a bottom core end 9 of the core 2 concentrically to a valve longitudinal axis 10, and partially surrounds the core end 9 axlally. Graduated spool body 3 overlaps partially the core 2 and the intermediate part 12 at least partially axially with a graduated step 15 of larger diameter. Downstream of the spool body 3 and of the intermediate part 12 a tube-shaped valve seating carrier 16, which is jointed firmly with the intermediate part 12, extends itself. In the valve seating carrier 16 a longitudinal bore 17 runs, which is designed concentrically to the valve longitudinal axis 10. In the longitudinal bore 17, a tube shaped valve needle 19 is arranged, which at its downstream end 20 is connected, for example through welding, with a ball shaped valve closing body 21, on circumference of which for example, 5 flattening 22 are visualized for the fuel to flow by. The valve needle 19 represents the movable actuation component of the fuel injection valve. An actuation of the injection valve happens in a known fashion electromagnetically. The electromagnetic circuit with the magnet spool 1, the core 2 and an anchor 27 serves the purpose of axial movement of the valve needle 19, and thus for opening against the spring force of a resetting spring 25 or closing of the injection valve. The anchor 27 Is connected with the opposite end of the valve wheel 19 to the valve closing body 21 through a weld seam 28, and is directed to the core 2. In the downstream opposite end of the valve seating carrier 16 to the core 2, a cylinder shaped metallic valve seating body 29, which has a fixed valve seating 13, is mounted in the longitudinal bore 17 in a leak-proof manner through welding. For guiding the valve closing body 21 during the axial movement of the valve needle 19, with the anchor 27 along the valve longitudinal axis 10, a guide opening 32 of the valve seating body 29 is made use of. The ball shaped valve closing body 21 acts in conjunction with the valve seating of the valve seating body 29 which in the flow direction narrows in a truncated cone shape. On its front side opposite to the valve closing body 21, the valve seating body 29 is concentrically and firmly jointed with a spray hole disc 34 designed for example in a pot shape. In the bottom part of the spray hole disc 34 at least one eject-spray opening 39, formed through eroding or punching runs; for example normally four such openings are provided. The depth of insertion of the valve seating body 29 with the pot shaped spray-hole disc 34, determines the setting of the stroke of the valve needle 19. In this context, an end position of the valve needle 19 is specified under non-excited magnet spool 1 through the placement of the valve closing body 21 and the valve seating of the valve seating body 29, while the other end position of the valve needle 19 is obtained under excited magnet spool 1 through the placement of the anchor 27 on the core end 9. An adjusting bushing / sleeve, which is formed for example from rolled spring steel sheet, shoved in a flow bore 46 of the core 2 running concentrically to the valve longitudinal axis 10, serves to adjust the initial spring tension of the resetting spring 25, which in turn supports itself with its opposite side on the valve needle 19, abutting the adjusting sleeve 48. The injection valve is enveloped largely with a plastic extrusion coat 50. An electrical connection socket 52 for example is also covered by the plastic extrusion coat 50. A fuel filter 51 protrudes in the flow bore 46 of core 2 towards its feed side end 55, and takes care of filtering out such fuel particles which could cause in the injection valve blockages or damages on account of their sides. In figure 2 a design example of an invention based fuel injection valve is shown. The fuel injection valve is designed with a simple and light structure / assembly. For this purpose, several components of the fuel injection valve are fabricated for example from a plastic or from a ceramic material, resulting in a mass reduction of the fuel injection valve. While in the known fuel injection valve as per figure 1, the plastic extrusion coat 50 is designed with the connecting plug 52 as well as the spool body 3 made of plastic, in the invention based design example, the components valve seating carrier 16 and valve needle 19 are also for example made of a plastic material. Therefore, one cannot speak of plastic extrusion coating of the fuel injection valve in a classical sense, because several components forming the valve housing are directly made of plastic material. The connecting neck 51 made of plastic forms for example the inflow channel of the fuel injection valve and seeks the fuel filter 61. The spool body 3 is so designed that the electrical connecting plug 52 forms part of it as a single component. The valve needle 19 in the design shown consists of three individual components, which together constitute the valve needle 19. The anchor 27, designed as rotary component, is the first individual component, while the ball shaped valve closing body 21 represents a second individual component of the valve needle 19. The connecting tube 23 jointing the anchor 27 with the valve closing body 21 represents a closing body carrier. The connecting tube 23 for example fabricated through plastic injection moulding and has an inner longitudinal opening / passage from which several cross openings branch out. The cross openings can optimally be equipped with a filter fabric 80 made of plastic or metal, which in the injection mouding process of the connecting tube 23 will be incorporated as an inlay component. On the bottom end facing the valve closing body 21 the anchor 27 has a saw¬teeth similar structure 23a with a "Christmas tree profile". This structure 23a corresponds with an upper expanded end of the connecting tube 23 made of plastic. For establishing a fixed connection between the anchor 27 and the connecting tube 23, the anchor 27 is pressed with its structure 63a in the connecting tube 23, that is in a manner that the structure 63a gets fixed firmly, securely and torsion-free at the end of the connecting tube 23. For seating the valve closing body 21, the connecting tube 23 is provided with a bulged or dome shaped recess 78. The dome shaped seating surface of the recess 78 ideally has a marginally smaller diameter than the diameter of the ball shaped valve closing body 21, as a result of which after the placement of the valve closing body 21 under marginal contact 4 a force-fit joint is established between the connecting tub 23 and the valve closing body 21. The valve closing body 21 is drawn through the connecting tube 23 during the flow of the magnet spool 1 securely reliably and reproducibly from the valve seating 30 of the valve seating body 29, even though the valve closing body 21 is held "loose" on the connecting tube 23. A ceramic material for example Si3N4 offers itself as a material for the valve closing body 21 designed as a whole ball. All the same, the valve closing body 21 can also be made of metallic or ceramic or plastic material. Comparable with the saw teeth similar structure 63a provided on the anchor 27 with a "Christmas tree profile", other saw teeth similar structures 63 can be thought of for establishing secure joints between fuel injection valve components made of metal and plastic. The core 2 on its two axial ends each has saw teeth similar structure 63b, 63c, which ensure that under pressed core 2 a secure and reliable jointing to the connection necks 51 made of plastic are guaranteed, and also to the spool body 3 made of plastic. Through the pressing of the core 2 in the connecting neck 51 and the spool body 3, the saw teeth similar structure 63b, 63c of the metallic component core 2 penetrate in the plastic of the corresponding joining partners, and the plastic consequentially get relaxed so that a secure and reliable firm joint is guaranteed between these components. Two other saw teeth similar structures 63d, 63 e are visualized with "Christmas tree profile" or a metallic magnetically conducting intermediate part 13, ,which is located under the spool body 3 in axial extension area of the anchor 27. This ring shaped intermediate component 13 is designed for example in profile as T-shape, where two sides of the T-profile have the structures 63d, 63e, and thus ensure a firm secure connection with the spool body 3 and with the valve seating carrier 16. The third radial side of the T-profile of the intermediate part 13 directed towards the outer is connected with a magnet pot 14, representing an external magnet component, through which the magnetic circuit is closed. At least in a certain overlapping area of the intermediate part 13 and spool body 3 or valve seat carrier 16, the inner walls of the spool body 3 and of the valve seating carrier 16 are formed with a somewhat offset, largely even surface. These surfaces pf the spool body 3 and of the valve seat carrier 16 correspond with the saw teeth similar structures 63d, 63e on the intermediate part 13. The intermediate part 13 Is pressed in these components for establishing firm jointings with the spool body 3 and the valve seat carrier 16, in such a manner that the structure 63d, 63e firmly hooks itself securely, firmly and torsion free on the surfaces of the spool body 3 and of the valve seating carrier 16. Through corresponding attachments 64, 65 on the spool body and the valve seating carrier 16, the depth of pressing of the intermediate part 13 in these components can be specified. The guide of the axially movable anchor 27 happens in the inner opening 66 of the intermediate part 13. In the bottom end of the plastic valve seat carrier 16, the valve seating body 29 is placed, made of a metal- or ceramic- material. The ceramic material Si3N4 offers itself has material for the valve seating body 29. Such a material has only one third of the weight of a comparably large component made of steel, as it is customarily used. Even the valve seating body 29 on its outer circumference, is designed with a saw teeth similar structure 63f, which can be defined as "Christmas tree profile". For establishing a firm jointing between the valve seating body 29 and the valve seat carrier 16, the valve seating body 29 is pressed with its structure 63f in the valve seating carrier 16 such that the structure 63f gets fixed securely, firmly and torsion-free at the bottom end of the valve seating carrier 16. The saw teeth similar structure 63f of the valve seating body 29 penetrates in to the plastic of the valve seating carrier 16 reforming it elastically and thereby bringing about a relaxation of the plastic in the saw teeth similar structure 63f. In figures 3, 4 and 5, three other examples of a plastic metal combination are shown in detailed views. These connection areas can be proposed at any position in the fuel injection valve, to which components made of plastic and metal correspond with one another to bring about a solid jointing. Additionally to the plastic-metal compounds referred to already in figure 2, which exemplify themselves exclusively through their saw teeth similar structure 63, the plastic-metal compounds illustrated in figures 3 and 4, have an additional profile area 70. This profile area 70 is designed as a knurl, which is formed through several parallel, perpendicular or sloped grooves or flutes, distributed over the circumference. With the use of this profile area 70, it is ensured that in metal components get fixed in the sleeve shaped plastic components with a form-fit and absolutely torsion-free. The profile area 70 can be provided at both ends of the saw teeth similar structure 63 of the metal components, as is made clear by figures 3 and 4. in figure 5, an alternative design example of a plastic-metal-combination Is shown in detail. The saw teeth similar structure 63 is always interrupted again through cylindrical segments 73. Such a structure 63 with segments 73 lying in between can also be provided additionally with a profile area 70. The shape of tooth of the saw teeth similar structure 63 can be designed as going towards the peak, inclined and perpendicular with a bend or bulge or in combination thereof. The saw teeth similar structure 63 is formed by several teeth which are designed successively. Especially 2 to 15 revolving teeth are proposed in a structure 63. The structure 63 can be designed with a sharp edge or with a smooth flow towards the respective cylindrical section 73. (Figure 5) The excitable actuator of the fuel injection valve has electro magnetic circuit with magnet spool 1, the core 2 intermediate part 13, magnet pot 14 and anchor 27 can for example, also be designed as piezo-electric or magneto-strictive drive. Patent Claims 1. Plastic-metal-combination between a metallic component and a component made of plastic, where the metallic component correspond with the component made of plastic for forming a secure and firm jointing, and that metallic component is pressed in the component made of plastic, is thereby characterized that at least on the metallic component in an area overlapping with the component made of plastic, a saw teeth similar structure is proposed. 2. Metal-plastic-combination as per claim 1 is thereby characterized that several successive revolving teeth formed in structure (63). 3. Metal-plastic-combination according to claim 2 is thereby characterized that 2-15 revolving teeth form the structure (63). 4. Metal-plastic-combination as per one of the above claims is thereby characterized that an additional profiled area (70) is designed on the saw teeth similar structure (63) 5. Metal-plastic-combination as per claim 4 is thereby characterized that the profiled area (70) is designed as knurl, formed through a number of parallel perpendicular or inclined grooves and flutes distributed over the circumference on at least on one end of the structure (63). 6. Metal-plastic-combination as per one of the above claims is thereby characterized that the saw teeth structure (63) is interrupted between the teeth through cylindrical section / segments (73). 7. Metal-plastic-combination as per one of the above claims is thereby characterized that the shape of the teeth of the saw teeth like structure (63) is formed as directly flowing to the peak, slanted and perpendicular with a bend or bulge or in combination thereof. 8. Fuel injection valve, especially for fuel injection systems of combustion engines, with a valve longitudinal axis (10), with an excitable actuator (1,2, 13, 14, 27) with a movable actuating component (19) which has a valve closing body (21), which works together with a fixed valve seating (30) where the valve seating (30) is formed on the valve seating body (29), is thereby characterized that at least one metallic component of the fuel injection valve on its outer circumference has a saw-teeth like structure (63a-f) for establishing a fixed joint with a corresponding component made of plastic. 9. Fuel injection valve, according to claim 8 is thereby characterized that at least one of the components connecting necks (51) valve seating carrier (16) spool body (3) and connecting tube (23) of the valve needle (19) is made of plastic. 10. Fuel injection valve, according to claim 9, is thereby characterized that the corresponding metallic component is pressed with the structure (63a-f) in the respective component made of plastic for firm jointing. 11. Fuel injection valve, according to claims 8 to 10 is thereby characterized that the excitable Actuator is an electro magnetic circuit, which encompasses a magnet spool (1) a core (2) and an anchor (27) where the core (2) is equipped with at least a saw teeth like structure (63b, 63c), with which a firm jointing with a connecting neck (51) and /or with a spool body (3) can be established. 12. Fuel injection valve, according to claim 11 is thereby characterized that the anchor 27 has a saw teeth like structure (63a) with which a connecting tube (23) of the valve needle (19) corresponds on a firm jointing. 13. Fuel injection valve according to claim 11 is thereby characterized that a metallic intermediate part (13) is proposed in proximity to the magnetic spool 1 for closing the magnetic circuit, where the intermediate part (13) is provided at least with a saw teeth like structure (63d, 63e), using which a firm jointing can be established with the spool body (3) and /or with a valve seating carrier (16). 14. Fuel injection valve, according to claim 13 is thereby characterized that the intermediate part (13) is designed in T-shape in profile, and has at least on one of the sides the saw teen like structure (63d, 63c). 15. Fuel injection valve, according to one of the claims 8 to 14, is thereby characterized that the valve seating body (29) is equipped with a saw teeth like structure (63f), with which a solid connection with the valve seating carrier (16) can be established 16. Fuel injection valve, according to claims 8 to 15 is thereby characterized that several successively revolving teeth form the structure (63a-f). 17. Fuel injection valve, according to claims 8 to 16 is thereby characterized that an additional profiled area (70) is formed on the saw teeth like structure (63a-f), which is especially designed as a knurl. 18. Fuel injection valve, according to claims 8 to 17 is thereby characterized saw teeth like structure (63a-f) is formed as directly flowing to the peak, slanted and perpendicular with a bend or bulge or in combination thereof.

Full Text

Plastic-metal combination and fuel injection valve with a Plastic-Metal combination
State of art of technology
The invention emanates from a plastic-metal combination according to generic description of claim 1 and from a fuel injection valve with a plastic-metal combination as per the generic description of claim 8.
In figure 1, a known fuel injection valve from the state of art of technology illustrated, which has a classical three-part structure of an inner metallic flow guide part and at the same time housing components. This inner valve tube is formed from a rotating field forming inlet nipple / neck, a non-magnetic intermediate part and a valve seat carrier accepting a valve seating, an axially movable valve needle is provided in the valve seating carrier which includes an anchor and a ball shaped valve closing body as well as a connecting tube jointing the anchor with the valve closing body. The three individual components of the valve needle are firmly jointed with one another with the use of a material to material jointing process, especially welding.
Already such a magnetically actuated valve in form of a fuel injection valve is known from patent document DE 40 08 675 A1. The inner valve tube forms the base frame of the entire injection valve and has in its entirety from the three individual components, a significant support function. The non-magnetic intermediate part is jointed through weld seams both leak-proof and firmly with the inlet nipple/neck as well as with the valve seating carrier. The windings of a magnet spool are located in a spool carrier made of plastic, which in turn surrounds in the circumferential direction a part of the inlet nipple serving as the rotating field, and also the intermediate part. An axially movable valve needle is provided in the valve seating carrier, which includes a sleeve / bushing shaped anchor and a ball shaped valve closing body as well as a connecting tube jointing the anchor with the valve closing body. The connecting tube is jointed firmly with the anchor and also with the valve closing body with the use of weld seams. The valve closing body acts in conjunction with a valve seating surface of a metallic valve seating body running in a truncated cone shape. The valve seating body is connected firmly with the valve seating carrier with a weld seam.
A further electro-magnetically operated valve in form of a fuel injection valve is known from patent document DE 195 03 224 A1. The fuel injection valve has a ball shaped valve closing body acting in conjunction with the valve seating, which is incorporated on a closing body carrier in the shape of a plastic tube, while at

the opposite end of the valve closing body, an anchor is fastened to the plastic tube. These components together form an axially movable valve needle. The bottom end of the plastic tube is designed in a cage-shape, where it is held in the bulged recess of the valve closing body in a positive fit with the use of snap on connection. The plastic tube is designed in the area of the bottom recess spring elastically, because the retainer jaws must overlap the valve closing body. The ball shaped valve closing body can be manufactured from steel, a ceramic or a plastic. The valve closing body works in cooperation with a valve seating surface of a metallic valve seating body running with a truncated cone shape. The valve seating body is connected firmly with the valve seating carrier with the use of weld seam.
Advantages of the invention
The invention based plastic metal combination with the characteristics of claim 1 has the advantage that they can be easily and cost competitively produced and nevertheless, an automatic assembly is guaranteed. The plastic metal press joints can be securely and reliably produced thereby that in the overlapping areas of the components to be respectively jointed saw-teeth-similar structures are optimally designed at least on the metallic component. The saw teeth-similar structure of the metallic component penetrates into the plastic of the corresponding component and deforms it elastically whereby a relaxation of the plastic happens in the saw teeth similar structure. The invention based design guarantees a high security against loosening of the joints through tightening against the assembly direction, and offers additionally a very high torsion security, which is especially desirable if both the corresponding components must be jointed in a specific rotation position with one another. A tension build¬up during the assembly / mounting is also excluded.
Advantageous further designs and improvements of the plastic-metal-combination mentioned under claim 1 are possible through the measures listed under the sub-claims.
The invention based fuel injection valve with the characteristic properties of claim 8 has the advantage that a simple and cost-effective manufacture can be realized, and automatic assembly of several individual components and thereby the entire valve is also realizable, since material to material jointing process, such as welding, which has the disadvantage of a heat distortion, and complex positive jointing techniques can be dispensed with. Advantageous press joints between a metallic component partner and a plastic component partner can be especially applied, which are easily, securely and reliably obtainable. The invention based arrangement as also the advantage of a reduction of the solid-borne sound and thereby noise development in contrast to the known solutions.

The plastic-metal pressed joint can be securely and reliably manufactured if in the overlapping areas of the components to be jointed, saw teeth similar structures are provided at least on the metallic component. The saw teeth similar structure of the metallic component penetrates into the plastic of the corresponding component, and deforms it elastically where upon a relaxation of the plastic in the saw teeth similar structure is obtained.
Advantageous further designs and improvements of the fuel injection valve indicated in the claim 8 are possible through the measures listed in the sub¬claims.
It is especially advantageous to produce from a plastic, the connection necks, the valve seating carrier and the valve needle, besides the spool body and the electrical connecting socket, which are then respectively jointed with the metallic components of the fuel injection valve. In this manner, the weight of the fuel injection valve can be reduced. Arising from the reduced weight of these components, the advantage of a better dynamic of the valve and a reduced noise development can also be realized.
It is advantageous also to design on the saw teeth similar structure an additional profile area. This profile area is designed as a knurl, which is formed by several parallel, perpendicular or slanted fins, grooves distributed over the circumference. Using this profile area it is advantageous ensured that the metal component is fixed with a positive fit and absolutely torsion proof in the sleeve shaped plastic component. The profile area can be provided on both ends of the saw teeth similar structure of the metallic component.
Drawing
Design examples of the invention are illustrated in the drawing in a simplified fashion, and explained in the following description.
Fig 1 shows a fuel injection valve in a known design as per the state of art of technology.
Fig 2 a design example of an invention based fuel injection valve with a number of fixed plastic metal-combinations between two respective components of the fuel injection valve.
Fig 3 a first additional design of a plastic-metal combination in a detailed view.
Fig 4 a second additional design example of a plastic-metal combination, and
Fig 5 a third additional design example of a plastic-metal combination.

Description of the design example
For a better understanding of the invention, a fuel injection valve is shown in a known design as per the state of art of technology in Figure 1. The electro magnetically actuated valve in form of an injection valve for fuel injection systems of carburetion remote-ignited combustion engines illustrated as an example in figure 1, has a core 2 surrounded by a magnet spool 1 and serving as fuel inlet nipple and rotating field, which for example here is designed in a tube shape, and has over its total length a constant outer diameter. A spool body 3 graduated in radial direction seats a winding / spooling of the magnet spool 1 and facilitates in conjunction with core 2 a contact assembly of the injection valve in the area of the magnet spool 1.
A tube shaped metallic non-magnetic intermediate part 12 is connected leak-proof with a bottom core end 9 of the core 2 concentrically to a valve longitudinal axis 10, and partially surrounds the core end 9 axlally. Graduated spool body 3 overlaps partially the core 2 and the intermediate part 12 at least partially axially with a graduated step 15 of larger diameter. Downstream of the spool body 3 and of the intermediate part 12 a tube-shaped valve seating carrier 16, which is jointed firmly with the intermediate part 12, extends itself. In the valve seating carrier 16 a longitudinal bore 17 runs, which is designed concentrically to the valve longitudinal axis 10. In the longitudinal bore 17, a tube shaped valve needle 19 is arranged, which at its downstream end 20 is connected, for example through welding, with a ball shaped valve closing body 21, on circumference of which for example, 5 flattening 22 are visualized for the fuel to flow by. The valve needle 19 represents the movable actuation component of the fuel injection valve.
An actuation of the injection valve happens in a known fashion electromagnetically. The electromagnetic circuit with the magnet spool 1, the core 2 and an anchor 27 serves the purpose of axial movement of the valve needle 19, and thus for opening against the spring force of a resetting spring 25 or closing of the injection valve. The anchor 27 Is connected with the opposite end of the valve wheel 19 to the valve closing body 21 through a weld seam 28, and is directed to the core 2. In the downstream opposite end of the valve seating carrier 16 to the core 2, a cylinder shaped metallic valve seating body 29, which has a fixed valve seating 13, is mounted in the longitudinal bore 17 in a leak-proof manner through welding.
For guiding the valve closing body 21 during the axial movement of the valve needle 19, with the anchor 27 along the valve longitudinal axis 10, a guide opening 32 of the valve seating body 29 is made use of. The ball shaped valve closing body 21 acts in conjunction with the valve seating of the valve seating body 29 which in the flow direction narrows in a truncated cone shape. On its front side opposite to the valve closing body 21, the valve seating body 29 is

concentrically and firmly jointed with a spray hole disc 34 designed for example in a pot shape. In the bottom part of the spray hole disc 34 at least one eject-spray opening 39, formed through eroding or punching runs; for example normally four such openings are provided.
The depth of insertion of the valve seating body 29 with the pot shaped spray-hole disc 34, determines the setting of the stroke of the valve needle 19. In this context, an end position of the valve needle 19 is specified under non-excited magnet spool 1 through the placement of the valve closing body 21 and the valve seating of the valve seating body 29, while the other end position of the valve needle 19 is obtained under excited magnet spool 1 through the placement of the anchor 27 on the core end 9.
An adjusting bushing / sleeve, which is formed for example from rolled spring steel sheet, shoved in a flow bore 46 of the core 2 running concentrically to the valve longitudinal axis 10, serves to adjust the initial spring tension of the resetting spring 25, which in turn supports itself with its opposite side on the valve needle 19, abutting the adjusting sleeve 48. The injection valve is enveloped largely with a plastic extrusion coat 50. An electrical connection socket 52 for example is also covered by the plastic extrusion coat 50. A fuel filter 51 protrudes in the flow bore 46 of core 2 towards its feed side end 55, and takes care of filtering out such fuel particles which could cause in the injection valve blockages or damages on account of their sides.
In figure 2 a design example of an invention based fuel injection valve is shown. The fuel injection valve is designed with a simple and light structure / assembly. For this purpose, several components of the fuel injection valve are fabricated for example from a plastic or from a ceramic material, resulting in a mass reduction of the fuel injection valve. While in the known fuel injection valve as per figure 1, the plastic extrusion coat 50 is designed with the connecting plug 52 as well as the spool body 3 made of plastic, in the invention based design example, the components valve seating carrier 16 and valve needle 19 are also for example made of a plastic material. Therefore, one cannot speak of plastic extrusion coating of the fuel injection valve in a classical sense, because several components forming the valve housing are directly made of plastic material. The connecting neck 51 made of plastic forms for example the inflow channel of the fuel injection valve and seeks the fuel filter 61. The spool body 3 is so designed that the electrical connecting plug 52 forms part of it as a single component.
The valve needle 19 in the design shown consists of three individual components, which together constitute the valve needle 19. The anchor 27, designed as rotary component, is the first individual component, while the ball shaped valve closing body 21 represents a second individual component of the valve needle 19. The connecting tube 23 jointing the anchor 27 with the valve closing body 21 represents a closing body carrier. The connecting tube 23 for example fabricated through plastic injection moulding and has an inner

longitudinal opening / passage from which several cross openings branch out. The cross openings can optimally be equipped with a filter fabric 80 made of plastic or metal, which in the injection mouding process of the connecting tube 23 will be incorporated as an inlay component.
On the bottom end facing the valve closing body 21 the anchor 27 has a saw¬teeth similar structure 23a with a "Christmas tree profile". This structure 23a corresponds with an upper expanded end of the connecting tube 23 made of plastic.
For establishing a fixed connection between the anchor 27 and the connecting tube 23, the anchor 27 is pressed with its structure 63a in the connecting tube 23, that is in a manner that the structure 63a gets fixed firmly, securely and torsion-free at the end of the connecting tube 23. For seating the valve closing body 21, the connecting tube 23 is provided with a bulged or dome shaped recess 78. The dome shaped seating surface of the recess 78 ideally has a marginally smaller diameter than the diameter of the ball shaped valve closing body 21, as a result of which after the placement of the valve closing body 21 under marginal contact 4 a force-fit joint is established between the connecting tub 23 and the valve closing body 21. The valve closing body 21 is drawn through the connecting tube 23 during the flow of the magnet spool 1 securely reliably and reproducibly from the valve seating 30 of the valve seating body 29, even though the valve closing body 21 is held "loose" on the connecting tube 23. A ceramic material for example Si3N4 offers itself as a material for the valve closing body 21 designed as a whole ball. All the same, the valve closing body 21 can also be made of metallic or ceramic or plastic material.
Comparable with the saw teeth similar structure 63a provided on the anchor 27 with a "Christmas tree profile", other saw teeth similar structures 63 can be thought of for establishing secure joints between fuel injection valve components made of metal and plastic. The core 2 on its two axial ends each has saw teeth similar structure 63b, 63c, which ensure that under pressed core 2 a secure and reliable jointing to the connection necks 51 made of plastic are guaranteed, and also to the spool body 3 made of plastic. Through the pressing of the core 2 in the connecting neck 51 and the spool body 3, the saw teeth similar structure 63b, 63c of the metallic component core 2 penetrate in the plastic of the corresponding joining partners, and the plastic consequentially get relaxed so that a secure and reliable firm joint is guaranteed between these components.
Two other saw teeth similar structures 63d, 63 e are visualized with "Christmas tree profile" or a metallic magnetically conducting intermediate part 13, ,which is located under the spool body 3 in axial extension area of the anchor 27. This ring shaped intermediate component 13 is designed for example in profile as T-shape, where two sides of the T-profile have the structures 63d, 63e, and thus ensure a firm secure connection with the spool body 3 and with the valve seating carrier 16. The third radial side of the T-profile of the intermediate part 13

directed towards the outer is connected with a magnet pot 14, representing an external magnet component, through which the magnetic circuit is closed.
At least in a certain overlapping area of the intermediate part 13 and spool body 3 or valve seat carrier 16, the inner walls of the spool body 3 and of the valve seating carrier 16 are formed with a somewhat offset, largely even surface. These surfaces pf the spool body 3 and of the valve seat carrier 16 correspond with the saw teeth similar structures 63d, 63e on the intermediate part 13. The intermediate part 13 Is pressed in these components for establishing firm jointings with the spool body 3 and the valve seat carrier 16, in such a manner that the structure 63d, 63e firmly hooks itself securely, firmly and torsion free on the surfaces of the spool body 3 and of the valve seating carrier 16. Through corresponding attachments 64, 65 on the spool body and the valve seating carrier 16, the depth of pressing of the intermediate part 13 in these components can be specified. The guide of the axially movable anchor 27 happens in the inner opening 66 of the intermediate part 13.
In the bottom end of the plastic valve seat carrier 16, the valve seating body 29 is placed, made of a metal- or ceramic- material. The ceramic material Si3N4 offers itself has material for the valve seating body 29. Such a material has only one third of the weight of a comparably large component made of steel, as it is customarily used. Even the valve seating body 29 on its outer circumference, is designed with a saw teeth similar structure 63f, which can be defined as "Christmas tree profile". For establishing a firm jointing between the valve seating body 29 and the valve seat carrier 16, the valve seating body 29 is pressed with its structure 63f in the valve seating carrier 16 such that the structure 63f gets fixed securely, firmly and torsion-free at the bottom end of the valve seating carrier 16. The saw teeth similar structure 63f of the valve seating body 29 penetrates in to the plastic of the valve seating carrier 16 reforming it elastically and thereby bringing about a relaxation of the plastic in the saw teeth similar structure 63f.
In figures 3, 4 and 5, three other examples of a plastic metal combination are shown in detailed views. These connection areas can be proposed at any position in the fuel injection valve, to which components made of plastic and metal correspond with one another to bring about a solid jointing. Additionally to the plastic-metal compounds referred to already in figure 2, which exemplify themselves exclusively through their saw teeth similar structure 63, the plastic-metal compounds illustrated in figures 3 and 4, have an additional profile area 70. This profile area 70 is designed as a knurl, which is formed through several parallel, perpendicular or sloped grooves or flutes, distributed over the circumference. With the use of this profile area 70, it is ensured that in metal components get fixed in the sleeve shaped plastic components with a form-fit and absolutely torsion-free. The profile area 70 can be provided at both ends of the saw teeth similar structure 63 of the metal components, as is made clear by figures 3 and 4.

in figure 5, an alternative design example of a plastic-metal-combination Is shown in detail. The saw teeth similar structure 63 is always interrupted again through cylindrical segments 73. Such a structure 63 with segments 73 lying in between can also be provided additionally with a profile area 70.
The shape of tooth of the saw teeth similar structure 63 can be designed as going towards the peak, inclined and perpendicular with a bend or bulge or in combination thereof. The saw teeth similar structure 63 is formed by several teeth which are designed successively. Especially 2 to 15 revolving teeth are proposed in a structure 63.
The structure 63 can be designed with a sharp edge or with a smooth flow towards the respective cylindrical section 73. (Figure 5)
The excitable actuator of the fuel injection valve has electro magnetic circuit with magnet spool 1, the core 2 intermediate part 13, magnet pot 14 and anchor 27 can for example, also be designed as piezo-electric or magneto-strictive drive.

Patent Claims
1. Plastic-metal-combination between a metallic component and a component made of plastic, where the metallic component correspond with the component made of plastic for forming a secure and firm jointing, and that metallic component is pressed in the component made of plastic, is thereby characterized that at least on the metallic component in an area overlapping with the component made of plastic, a saw teeth similar structure is proposed.
2. Metal-plastic-combination as per claim 1 is thereby characterized that several successive revolving teeth formed in structure (63).
3. Metal-plastic-combination according to claim 2 is thereby characterized that 2-15 revolving teeth form the structure (63).
4. Metal-plastic-combination as per one of the above claims is thereby characterized that an additional profiled area (70) is designed on the saw teeth similar structure (63)
5. Metal-plastic-combination as per claim 4 is thereby characterized that the profiled area (70) is designed as knurl, formed through a number of parallel perpendicular or inclined grooves and flutes distributed over the circumference on at least on one end of the structure (63).
6. Metal-plastic-combination as per one of the above claims is thereby characterized that the saw teeth structure (63) is interrupted between the teeth through cylindrical section / segments (73).
7. Metal-plastic-combination as per one of the above claims is thereby characterized that the shape of the teeth of the saw teeth like structure (63) is formed as directly flowing to the peak, slanted and perpendicular with a bend or bulge or in combination thereof.
8. Fuel injection valve, especially for fuel injection systems of combustion engines, with a valve longitudinal axis (10), with an excitable actuator (1,2, 13, 14, 27) with a movable actuating component (19) which has a valve closing body (21), which works together with a fixed valve seating (30) where the valve seating (30) is formed on the valve seating body (29), is thereby characterized that at least one metallic component of the fuel injection valve on its outer circumference has a saw-teeth like structure (63a-f) for establishing a fixed joint with a corresponding component made of plastic.

9. Fuel injection valve, according to claim 8 is thereby characterized that at
least one of the components connecting necks (51) valve seating carrier
(16) spool body (3) and connecting tube (23) of the valve needle (19) is
made of plastic.
10. Fuel injection valve, according to claim 9, is thereby characterized that the
corresponding metallic component is pressed with the structure (63a-f) in
the respective component made of plastic for firm jointing.
11. Fuel injection valve, according to claims 8 to 10 is thereby characterized
that the excitable Actuator is an electro magnetic circuit, which
encompasses a magnet spool (1) a core (2) and an anchor (27) where the
core (2) is equipped with at least a saw teeth like structure (63b, 63c), with
which a firm jointing with a connecting neck (51) and /or with a spool body
(3) can be established.
12. Fuel injection valve, according to claim 11 is thereby characterized that the anchor 27 has a saw teeth like structure (63a) with which a connecting tube (23) of the valve needle (19) corresponds on a firm jointing.
13. Fuel injection valve according to claim 11 is thereby characterized that a metallic intermediate part (13) is proposed in proximity to the magnetic spool 1 for closing the magnetic circuit, where the intermediate part (13) is provided at least with a saw teeth like structure (63d, 63e), using which a firm jointing can be established with the spool body (3) and /or with a valve seating carrier (16).
14. Fuel injection valve, according to claim 13 is thereby characterized that
the intermediate part (13) is designed in T-shape in profile, and has at
least on one of the sides the saw teen like structure (63d, 63c).
15. Fuel injection valve, according to one of the claims 8 to 14, is thereby
characterized that the valve seating body (29) is equipped with a saw
teeth like structure (63f), with which a solid connection with the valve
seating carrier (16) can be established
16. Fuel injection valve, according to claims 8 to 15 is thereby characterized
that several successively revolving teeth form the structure (63a-f).
17. Fuel injection valve, according to claims 8 to 16 is thereby characterized
that an additional profiled area (70) is formed on the saw teeth like
structure (63a-f), which is especially designed as a knurl.
18. Fuel injection valve, according to claims 8 to 17 is thereby characterized
saw teeth like structure (63a-f) is formed as directly flowing to the peak,
slanted and perpendicular with a bend or bulge or in combination thereof.

Documents:

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Patent Number

268685

Indian Patent Application Number

3149/CHENP/2008

PG Journal Number

37/2015

Publication Date

11-Sep-2015

Grant Date

11-Sep-2015

Date of Filing

23-Jun-2008

Name of Patentee

Robert Bosch GmbH

Applicant Address

POSTFACH 30 02 20, 70442 STUTTGART

Inventors:

#	Inventor's Name	Inventor's Address
1	REITER, FERDINAND,	BURGWEG 1, 71706 MARKGROENINGEN

PCT International Classification Number

F02M61/16

PCT International Application Number

PCT/EP06/67909

PCT International Filing date

2006-10-30

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102005061408.6	2005-12-22	Germany