| Title of Invention | FUEL INJECTION VALVE |
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| Abstract | Abstract FUEL INJECTION VALVE 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 the valve seat element (29) has a serrated structure (63f) for establishing a solid connection to the valve seat support (16). The fuel injection valve is especially suitable for use in fuel injection systems of mixture-compressing spark ignition engines. |
| Full Text | Fuel injection valve State of art of technology The invention relates to a fuel injection valve as per the generic description of the main claim. A known fuel injection valve from the state of art of technology is illustrated in figure 1, which has a classical three-part assembly of an inner metallic flow guiding part and at the same time housing parts. 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 bail 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 me use or 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 fuel injection valve with the characteristic properties of the main claim has the advantage that a simple and cost competitive manufacture and automatic assembly of the valve, especially of the valve seating body, can be realized, because one could dispense with material-to-material jointing processes such as welding having the disadvantage of a heat distortion as well as expensive form-fit jointing techniques. What is more especially advantageous press joints between a metallic component partner and a non-metallic component partner can be applied, which can be implemented in a simple secure and reliable-manner. The invention based arrangement /configuration has in addition the advantage of a reduction of the solid borne sound and therewith the noise development in contrast to the known solutions. Advantageous further designs and improvements of the fuel injection valve indicated in the main claim 1 are possible through the measures listed under the sub-claims. Especially advantageously the valve seating body can be fastened through pressing-in in the valve seating carrier. The valve seating body is advantageously produced from a ceramic material, as a result of which the weight of the fuel injection valve can be reduced. For reduction of the weight of the fuel injection valve, the valve seating carrier is made of plastic. Resulting from the reduced weight of these components, the advantage of a better dynamic of the valve and a reduced noise can be reaped. The plastic-ceramic pressed joints can be securely and reliably manufactured if in the overlapping areas of the valve seating body and valve seating carrier, saw teeth similar structures are designed optimally. The saw teeth similar stnjcture of the ceramic-component valve seating body penetrates into the plastic of the valve seating carrier, and subsequently the plastic relaxes. 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 Fig 3 a valve seating body in invention based design Fig 4 a top view on the valve seating body as per figure 3. Description of the design examples 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 electna 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 through welding with a bottom core end 9 of the core 2 concentrically to a vaive longitudinal axis 10, and partially surrounds the core end 9 axially, 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 dosing 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 roiled 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 extnjsion coat 50. A fuel filter 61 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 63a with a "Christmas tree profile". This structure 63a 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-in core 2 a secure and reliable jointing to the connection necks 51 made of plastic as well as to the spool body 3 made of plastic is guaranteed. Two other saw teeth similar structures 63d, 63e with "Christmas tree profile" are proposed on a metallic, magnetically conducting intermediate part 13, which is located underneath the spool body 3 in axial extension area of the anchor 27. This ring-shaped intermediate part 13 is designed for example in profile T-shape, where two sides of the key profile have the structures 63d, 63e and thereby take care of a fixed and secure jointing with the spool body 3 and the valve seating carrier 16. The third radial outward directed side of the T-profile of the intermediate part 13 is connected with a magnet pot 14 representing an outer magnet component, through which the magnet circuit is closed. According to the invention, the valve seating body 29, which is made of ceramic material, is placed in the bottom end of the valve seating carrier 16 made of plastic. The ceramic material Si3N4 offers itself as 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-in 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 ceramic valve seating body 29 penetrates into the plastic of the valve seating carrier 16 and thereby bringing about a relaxation of the plastic. In figure 3, a valve seating body 29 as individual component is shown in enlarged illustration. Different design possibilities of the saw teeth similar structure 63f are commonly illustrated in figure 3. It can be seen from figure 3 that the tooth form of the structure 63f can be designed as going towards the peak, (Za), inclined and perpendicular with a bend (Zb) or bulged (Zc) or in combination thereof. Figure 4 is a top view on the valve seating body 29 as per figure 3. From the top view it is clear that the guide opening 32 for the axially movable valve needle 19 with the valve closing body 21 can be interrupted several times. To that extent, the guide opening 32 forms only individual guide segments which altematingly are designed with larger diameter flow grooves 33 on the circumference. Through the flow grooves 33 the fuel can be conducted in direction of the valve seating 13 unhindered. Even only one flow groove 33 can be intended. The excitable actuator of the fuel injection valve as electromagnetic circuit with magnet spool 1 core 2, the intermediate part 13, the magnet pot 14 and the anchor 27 can for example be designed even as piezo-electric or magneto- strictive drive. Claims 1. Fuel injection valve especially fuel injection systems or combustion engines, with a valve longitudinal axis 10, with an excitable actuator (1,2,13,14,27) with a movable actuation part (19), having a valve closing body (21) which works together with a fixed valve seating (30) where the valve seating (30) is formed on a valve seating body (29), and with a valve seating carrier (16) in which the valve seating body (29) is located, is thereby characterized that the valve seating body (29) has on its outer circumference, a saw tooth similar structure (63f) for establishing a firm jointing with the valve seating carrier (16). 2. Fuel injection valve according to claim 1 is thereby characterized that the valve seating body (29) is made of a ceramic material, especially Si3n4. 3. Fuel injection valve according to claim 1 or 2 is thereby characterized that the valve seating carrier (16) is made of a plastic. 4. Fuel injection valve according to one of the above claims is thereby characterized that the valve seating body (29) can be located in the valve seating carrier (16) through pressing-in. 5. Fuel injection valve according to one of the above claims is thereby characterized that the shape of the tooth of the structure (63f) is designed directly flowing towards the peak (Za), flowing inclined and perpendicular with bend (Zb) or flowing bulged (Zc) or in combination thereof. 6. Fuel injection valve according to one of the above mentioned claims is thereby characterized that in the valve seating body (29) a guide opening (32) is visualized for the valve closing body (21), which has at least one interruption as flow-groove (33). 7. Fuel injection valve according to one of the above claims is thereby characterized that the valve closing body (21) is made of a metallic or ceramic material. 8. Fuel injection valve is thereby characterized that connecting tube (23) as part of a valve needle (19) represents an individual component made of plastic, where the connecting tube (23) joins an anchor (27) with valve closing body (21). 9. Fuel injection valve according to claim 8 is thereby characterized that on the anchor (27) a saw teeth similar structure (62a) is intended, which is pressed into the connection tub (23) for establishing a solid connection with the connecting tube (23). O.Fuel injection valve according to one of the above claims is thereby characterized that the valve closing body (21) is held on the connecting tube (23) of the valve needle (19) loose and free of additional material. |
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| Patent Number | 272195 | ||||||||
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| Indian Patent Application Number | 3170/CHENP/2008 | ||||||||
| PG Journal Number | 14/2016 | ||||||||
| Publication Date | 01-Apr-2016 | ||||||||
| Grant Date | 21-Mar-2016 | ||||||||
| Date of Filing | 23-Jun-2008 | ||||||||
| Name of Patentee | ROBERT BOSCH GMBH | ||||||||
| Applicant Address | POSTFACH 30 02 20, 70042 STUTGART | ||||||||
Inventors:
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| PCT International Classification Number | F02M61/18 | ||||||||
| PCT International Application Number | PCT/EP06/68216 | ||||||||
| PCT International Filing date | 2006-11-08 | ||||||||
PCT Conventions:
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