JP4217453B2 - Fuel injection valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection valve, particularly a fuel injection valve for directly injecting fuel into a fuel chamber of an air-fuel mixture compression type spark ignition type internal combustion engine, a mover cooperating with a magnet coil, the mover and a sleeve And a valve closing body that forms a seal seat together with the valve seat surface, and is further provided between the sleeve and the mover. The present invention relates to a type in which a front stroke spring is arranged and a stopper ring that functions as a mover stopper is arranged on the downstream side of the mover.
[0002]
[Prior art]
A fuel injection valve for a fuel injection device of an internal combustion engine is already known on the basis of DE 198449210, this known fuel injection valve being returned in the upward stroke direction by a magnet coil. A mover that can be loaded against the spring and a valve needle coupled to the valve closure. The mover is coupled to the valve needle and restricts the movement of the mover in the upward stroke direction. The mover is coupled to the valve needle and moves the mover in the direction opposite to the upward stroke direction. It is movable between the second stopper to be limited. A buffer spring in the form of a disc spring is disposed between the second stopper and the mover.
[0003]
The disadvantages of the known fuel injection valve based on the German patent specification DE 198449210 are as follows. That is, with this known fuel injection valve, on the one hand, the labor and costs associated with manufacturing and assembly are increased or increased by at least one additional component. On the other hand, there is a risk that the mover may be displaced or caught during operation of the fuel injection valve due to, for example, an oblique insertion of a disc spring or a manufacturing error caused during manufacturing. As a result, a strong variation in the free movement distance of the mover or the height of the previous stroke gap occurs. The uncompensated wear phenomenon thereby causes malfunctions during operation of the fuel injector.
[0004]
[Patent Document 1]
German Patent Publication No. 198449210 [0005]
[Problems to be solved by the invention]
The object of the present invention is therefore to improve the function of the fuel injection valve by improving the fuel injection valve of the type mentioned at the beginning and compensating for the wear phenomenon in the fuel injection valve in a simple manner. is there.
[0006]
[Means for Solving the Problems]
In order to solve this problem, in the configuration of the present invention, the end surface of the stopper ring directed to the mover and / or the mover, the corresponding surface corresponding to the end surface and / or the sleeve of the stopper ring is directed to the mover. At least one notch for reducing the effective stopper area of the end face is formed on the end face and / or the corresponding surface of the mover corresponding to the end face.
[0007]
【The invention's effect】
The fuel injection valve according to the present invention configured as described above has the following advantages over the known one. That is, in the fuel injection valve according to the present invention, the end face of the sleeve and the stopper ring in the area of the mover can be reduced as desired, thereby affecting the wear phenomenon that occurs on these end faces, and in this case in particular the fuel Since the wear phenomenon in the other members of the injection valve can be compensated, the stroke of the valve needle is kept constant.
[0008]
Another advantageous configuration of the fuel injection valve according to the invention is described in claim 2 and below.
[0009]
In a particularly advantageous configuration of the invention, the member in question is provided in a simple manner with radial notches or ring-like notches, whereby the area of the end face can be varied arbitrarily.
[0010]
In this case, the number, size, and arrangement of the notches in the radial direction are arbitrary.
[0011]
The notches can be produced in a simple and inexpensive manner, for example by milling.
[0012]
A simple formation and production of the ring-shaped notch is particularly advantageously possible in the same working process during the production of the component, for example by turning.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0014]
Before the detailed description of the preferred embodiment of the fuel injection valve 1 according to the invention shown in FIGS. 2 to 5, the fuel injection will first be made with reference to FIG. The main components of the valve 1 will be briefly described.
[0015]
The fuel injection valve 1 is configured in the form of a fuel injection valve for a fuel injection device of an air-fuel mixture compression type spark ignition type internal combustion engine. The fuel injection valve 1 is particularly suitable for directly injecting fuel into a combustion chamber (not shown) of an internal combustion engine.
[0016]
The fuel injection valve 1 includes a nozzle body 2, and a valve needle 3 is disposed in the nozzle body 2. The valve needle 3 is operatively connected to a valve closing body 4, and this valve closing body 4 cooperates with a valve seat surface 6 arranged on the valve seat body 5 to form a seal seat. In the illustrated embodiment, the fuel injection valve 1 is a fuel injection valve 1 that opens inward, and this fuel injection valve 1 has one injection opening 7. The nozzle body 2 is sealed against the outer pole 9 of the magnet coil 10 by a seal member 8. The magnet coil 10 is encapsulated in a coil casing 11 and is wound around a coil holder 12, and the coil holder 12 is in contact with the inner pole 13 of the magnet coil 10. The inner pole 13 and the outer pole 9 are separated from each other by a gap 26 and supported by a coupling member 29. The magnet coil 10 is excited by a current that can be supplied via a conductor 19 and an electrical contact 17. The insertion contact 17 is surrounded by a plastic peripheral wall 18 that can be injection-molded on the inner pole 13.
[0017]
The valve needle 3 is guided in a valve needle guide 14, and the valve needle guide 14 is formed in a disc shape. A pair of stopper rings 15 function as stroke adjustments and as lower mover stoppers. A mover 20 is disposed on the other side of the stopper ring 15. The mover 20 is coupled to the valve needle 3 via a sleeve 21 in a frictional force coupling manner. A return spring 23 is supported on the sleeve 21, and this return spring 23 is preloaded by a sleeve 24 in the illustrated configuration of the fuel injection valve 1. A front stroke spring 22 is arranged between the mover 20 and the sleeve 21, and the front stroke spring 22 has a smaller spring constant than the return spring 23, and is related to the front stroke gap 34. , Allowing pre-acceleration of the mover 20 over the free movement distance of the mover before the valve needle 3 is attracted.
[0018]
The sleeve 21 and the stopper ring 15 preferably have a surface structure pattern, which is formed, for example, in the form of various types of cutouts 31, whereby the mover 20 of the sleeve 21 is formed. The end surface 32 on the outflow side directed to the end surface and the end surface 33 on the supply side of the stopper ring 15 facing the mover 20 can be formed as follows, that is, due to the operation of the fuel injection valve 1. Thus, it is possible to control the wear occurring at the end faces 32 and 33 so that the wear phenomenon is compensated for in the other members of the fuel injection valve 1 and thus does not cause a change in the stroke of the valve needle 3. This makes it possible to avoid malfunctions during sustained operation, for example due to very large static and / or dynamic flow rates due to a very large stroke of the valve needle 3. The cutout 31 can alternatively or additionally be realized on the corresponding surface 38 or the corresponding surface 39 of the mover 20.
[0019]
Next, the treatment according to the present invention will be described in detail with reference to FIGS.
[0020]
Fuel passages 30 a to 30 c extend in the valve needle guide 14, the mover 20, and the valve seat body 5. The fuel is supplied through the central fuel supply unit 16 and is filtered by the filter element 25. The fuel injection valve 1 is sealed against a fuel distribution conduit (not shown) by a seal member 28.
[0021]
In the rest state of the fuel injection valve 1, the mover 20 is loaded in a direction opposite to the upward stroke direction by the return spring 23 via the sleeve 21 in the valve needle 3, so that the valve closing body 4 is in sealing contact with the valve seat 6. Kept in a state. The mover 20 is placed on the stopper ring 15. When the magnet coil 10 is excited, the magnet coil 10 forms a magnetic field. The magnetic field first moves the mover 20 in the upward stroke direction against the spring force of the front stroke spring 22, and then the force of the return spring 23. Move in the upward direction against The stroke of the mover 20 is in this case divided into a previous stroke which serves to close the previous stroke gap 74 and an open stroke which is determined by the working gap 27 between the inner pole 13 and the mover 20 in the resting state. Has been. After carrying out the previous stroke, the mover 20 entrains the sleeve 21 welded to the valve needle 3 and, consequently, the valve needle 3 in the upward stroke direction. The valve closing body 4 operatively connected to the valve needle 3 is lifted from the valve seat surface 6, whereby fuel is injected.
[0022]
When the coil current is interrupted, the mover 20 drops from the inner pole 13 toward the sleeve 21 due to the pressure of the return spring 23 after the magnetic field is sufficiently extinguished, so that the valve needle 3 is in the upward stroke direction. Exercise in the opposite direction. As a result, the valve closing body 4 is placed on the valve seat surface 6 and the fuel injection valve 1 is closed. The mover 20 is placed on the stopper ring 15.
[0023]
FIG. 2 is an enlarged sectional view showing the section indicated by II in FIG. 1 of the fuel injection valve 1 according to the present invention. The same reference numerals are used for the same members in all drawings.
[0024]
As already described with reference to FIG. 1, the lower mover stopper is formed by the stopper ring 15 inserted into the notch 35 of the fuel injection valve 1. The stopper ring 15 has a notch 31, which is provided in the stopper ring 15 in the radial direction in the illustrated embodiment, thereby forming a zinnenartig surface structure pattern. ing. The area of the end face 33 of the stopper ring 15 facing the movable element 20 is thereby reduced compared to the entire stopper ring 15. The wear phenomenon at the end face 33 caused by the contact of the mover 20 with the stopper ring 15 when the fuel injection valve 1 is closed acts to reduce the stroke.
[0025]
The sleeve 21 shown without the front stroke spring 22 for the sake of clarity in FIG. 2 also has a notch 31 extending radially in the end face 32 directed towards the mover 20. Similarly, the notch 31 forms a sawtooth surface structure pattern. This similarly reduces the area of the end face 32 that can come into contact with the mover 20. When the fuel injection valve 1 is opened, the wear phenomenon that occurs when the mover 20 comes into contact with the sleeve 21 after performing the previous stroke similarly acts to reduce the stroke.
[0026]
The wear phenomenon of both parts thus acts in the same direction, i.e. to reduce the stroke and thus to reduce the switching time. However, the wear phenomenon also occurs in other members of the fuel injection valve 1, particularly in the seal seat and the inner pole 13, and this wear phenomenon acts to increase the stroke, so the wear phenomena in both directions cancel each other. I can meet each other.
[0027]
The process change is compensated in particular by: That is, in this case, the wear phenomenon that occurs at the seal seat and the mover stopper on the upper side of the inner pole 13 and unacceptably increases the stroke of the valve needle 3 is caused by the mover stopper on the lower side of the stopper ring 15 after the previous stroke. Compensated by a controllable wear phenomenon in the sleeve 21. This is because the latter wear phenomenon reduces the stroke of the valve needle 3. When the surface structures of the end faces 32, 33 are configured to compensate for the wear phenomenon as desired, the wear phenomenon no longer has the effect of changing the stroke as a whole.
[0028]
In this case, changing the components, i.e. the stopper ring 15 and the sleeve 21 so that the determined wear effect can occur, causes the wear phenomenon in the seal seat to be a complicated deformation of the valve seat body 5 or the valve seat surface 6. It is significantly easier to compensate than The influence on the wear resistance strength of the movable element abutting surface of the inner pole 13 with which the movable element 20 abuts after performing the opening stroke is also only difficult due to the given nature of the hydraulic pressure. Not possible.
[0029]
FIG. 3A shows the sleeve of the fuel injection valve constructed as in the present invention, indicated by reference numeral 21 in FIG.
[0030]
As already described with reference to FIG. 2, the sleeve 21 has the notch 31 on the end surface 32 on the outflow side facing the movable element 20. In the illustrated embodiment, four notches 31 are provided. The retaining function of the sleeve 21 for the front stroke spring 22 is not impaired by the notch 31. This is because the front stroke spring 22 is contracted between the mover 20 and the collar 36.
[0031]
FIG. 3B shows a plan view of the sleeve 21 shown in FIG. 3A as viewed from above. In this case, the notches 31 are provided on the end face 32 of the sleeve 21 at equal angular intervals of about 90 °, thereby creating a sawtooth-like surface structure pattern. The surface of the end face 32 is reduced by the area value lowered at the notch 31. In order to control the wear phenomenon as desired, a greater or lesser number of notches 31 with a larger or smaller angular extension (Winkelausdehnung) can be provided at a greater or smaller distance from each other. Is possible.
[0032]
FIG. 4A shows a first embodiment of the stopper ring indicated by reference numeral 15 in FIG. 2 of the fuel injection valve 1 configured as in the present invention.
[0033]
Similar to the sleeve 21 already described, the first embodiment of the stopper ring 15 according to the invention shown in FIG. 4A has a plurality of notches 31 which reduce the area of the stopper ring 15. In the first embodiment, twelve notches 31 are provided in this case, and these notches 31 are obtained from the plan view of FIG. 4b which is a top view of the stopper ring 15 shown in FIG. 4A. As can be seen, they are arranged at a constant angular spacing of about 30 ° from each other.
[0034]
In order to control the wear phenomenon as desired, in this embodiment as well, a greater or lesser number of notches 31 with a greater or lesser angular extension are spaced apart from each other by a greater or lesser distance. Can be provided.
[0035]
FIGS. 5A and 5b show a sectional view and a plan view of a second embodiment of the stopper ring indicated by reference numeral 15 in FIG. 2 of the fuel injection valve 1 configured as in the present invention. Yes.
[0036]
Unlike the first embodiment shown in FIGS. 4A and 4b, the stopper ring 15 does not have a plurality of notches 31 extending radially here, but a single ring-like notch 37. The notch 37 is formed in a region outside the stopper ring 15 in the radial direction. The mode of action of the ring-shaped notch 37 corresponds to the mode of action of the notch 31 extending in the radial direction. This is because the area of the end face 33 directed to the mover 20 is reduced as well.
[0037]
In order to influence the wear phenomenon, the ring-shaped notch 37 can be configured to be wider or narrower in the radial direction.
[0038]
The second embodiment stands out especially in this case due to its simple manufacturability, for example by turning or milling.
[0039]
The ring-shaped notch 37 can also be applied to the sleeve 21 in which such a notch can be similarly provided in the radially outer region.
[0040]
The present invention is not limited to the illustrated embodiment, and may be of any structural type of fuel injector 1 for other shaped movers 20 such as, for example, plunger and flat movers. Can also be used.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing one embodiment of a fuel injection valve according to the present invention.
FIG. 2 is an enlarged view of a region II of the fuel injection valve according to the present invention shown in FIG. 1 in a slightly modified structure.
FIG. 3A is a view showing a sleeve indicated by reference numeral 21 in FIG. 2 of a fuel injection valve according to the present invention;
FIG. 3B is a plan view showing the sleeve shown in FIG. 3A.
4A is a view showing a stopper ring indicated by reference numeral 15 in FIG. 2 of a fuel injection valve according to the present invention. FIG.
4B is a plan view showing the stopper ring shown in FIG. 4A. FIG.
FIG. 5A is a view showing a second embodiment of the stopper ring indicated by reference numeral 15 in FIG. 2 of the fuel injection valve according to the present invention.
FIG. 5B is a plan view showing the stopper ring shown in FIG. 5A.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel injection valve, 2 Nozzle body, 3 Valve needle, 4 Valve closing body, 5 Valve seat body, 6 Valve seat surface, 7 Injection opening, 8 Seal member, 9 Outer pole, 10 Magnet coil, 11 Coil casing, 12 Coil Holder, 13 Inner pole, 14 Valve needle guide, 15 Stopper ring, 16 Fuel supply part, 17 Insertion contact, 20 Movable element, 21 Sleeve, 22 Front stroke spring, 23 Return spring, 24 Sleeve, 26 Gap, 27 Working gap 28, sealing member, 29 coupling member, 30a-30c fuel passage, 31 notch, 32, 33 end face, 34 front stroke gap, 35 notch, 36 collar, 37 notch, 38, 39 corresponding surface

Claims (9)

A fuel injection valve (1), a mover (20) cooperating with a magnet coil (10), and a valve needle (3) operatively coupled to the mover (20) via a sleeve (21) The valve needle (3) is provided with a valve closing body (4) that forms a seal seat together with the valve seat surface (6), and further includes a sleeve (21) and a mover (20 ) Is provided with a front stroke spring (22), and a stopper ring (15) acting as a mover stopper for restricting movement of the mover (20) in the valve closing direction is provided downstream of the mover (20). In the type arranged on the side,
A stopper ring (15), the armature end face directed towards the (20) (33) or movable element (20), the corresponding surface corresponding to the end face (33) (38), said end face (33) or A fuel injection valve characterized in that at least one notch (31; 37) is formed which reduces the effective stop area of the corresponding surface (38) .   2. The fuel injection valve according to claim 1, wherein a plurality of notches (31) are provided. 3. The fuel injection valve according to claim 2, wherein the notch (31) is provided in the end face ( 33) in the radial direction.   The fuel injection valve according to any one of claims 1 to 3, wherein the radial cutouts (31) are provided on the end face (32; 33) at equal angular intervals.   5. The fuel injection valve according to claim 1, wherein the radial notch (31) uses an equal angular region.   The fuel injection valve according to claim 1, wherein the notch (37) is formed in a ring shape. The fuel injection valve according to claim 6, wherein the ring-shaped notch (37) is formed in a radially outer region of the end face ( 33).   The fuel injection valve according to claim 6 or 7, wherein the ring-shaped notch (37) is formed by turning.   9. The fuel injection valve according to claim 1, wherein the notch (31; 37) is formed by milling.

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