JPH02190684A - Solenoid valve, especially fuel injection valve for fuel injector - Google Patents

Abstract

PURPOSE: To quicken the speed of a valve opening/closing operation by engaging a compression spring with a valve closure element directly or via a corresponding spring receiver so as to operate the same. CONSTITUTION: One end of a compression spring 26 is supported by the support surface 25 of a valve closure element 23, this spring 26 applies a spring load directed to a valve seat surface 18 on the valve closure element 23, the contact end 27 of the spring 26 is engaged with a spring receiver 28, and the spring receiver 17 is fixed in the through-hole 11 of a nozzle holder 10 after the spring force of the spring 26 is adjusted. Also, a flow passage hole 29 and a center hole 30 which penetrate axially are formed in the spring receiver 28, and fuel is passed with almost no restriction of the holes. A connecting member 33 is inserted into the holder hole 32 of the valve clossure element 23 and connected so as to be immobile, and the connecting element 33 is put through the spring 26 and the spring receiver 28 to be connected to an armature 35. Thus, since the spring force of the spring 26 is not applied on the connecting element 33, the cross-section of the connecting element 33 is made small, its mass is reduced, the mass of a valve movable portion composed of the valve closure element 23, the connecting element 33 and the armature is reduced, and a valve operation is quickened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solenoid valve, in particular a fuel injection valve for a fuel injection device of a mixture compression-spark ignition internal combustion engine, which is surrounded by a valve casing and an excitation coil. The valve has a core provided in the nozzle body, a valve seat surface provided in the nozzle body, and a valve closing body cooperating with the valve seat surface, the valve closing body being coupled to the mover via an elongated coupling body. It relates to a spring-loaded version in the direction of the seat by a compression spring surrounding the combination. Electromagnetic valves of this type are known in which the armature is connected via a connection formed as a rod to a ball that serves as a valve closing body. (
DE-0583000622), a compression spring acts on this armature in the direction of closing the valve and presses the coupling body, so that the coupling body is prevented from bending laterally. It must be manufactured to a relatively large cross section. Furthermore, in this case, it is ensured that the coupling body does not easily bend laterally, resulting in locking due to tilting of the armature and the valve closing body, thereby impairing the opening and closing operation of the valve. There must be. However, in known valves, the coupling body is manufactured with a large cross section in order to avoid bending of the coupling body, which results in a relatively large mass of the movable parts of the valve. However, solenoid valves as fuel injection valves for electronically controlled fuel injection systems must have as large a linear function range as possible for the fuel injection quantity in order to meet the technical demands imposed today. In other words, the linear ratio of the valve opening timing from the maximum injection amount to the minimum injection amount must be made as large as possible, in short, it must be configured so that it exceeds 1 oll. This problem can only be solved if a magnetic circuit with high efficiency is used and the movable parts of the valve, namely the valve armature, coupling body and valve closing body, are constructed in such a way that they have as little mass as possible. This is a problem. Fuel injection valves are already known in which a compression spring surrounds a tubular assembly (D
H-OS No. 2141264). In this case, however, one end of the spring is supported by a guide block that guides the coupling body, and the other end engages the coupling body approximately one third of its total length and acts in the valve closing direction. For this reason, the connecting part between the spring end and the valve closing body still has a very large wall thickness, taking into account the spring load of the compression spring acting on it, so that in this known valve The mass of the moving parts of the valve has not yet been sufficiently reduced.

In contrast, the valve of the present invention having the features set forth in claim 1 has the following advantages. That is,
Since the compression spring directly engages and acts on the valve closing body, it is possible to reduce the cross section of the coupling body, and thus
The mass of the moving parts of the valve is reduced, which allows for rapid switching of the valve to open and close, thereby extending the linear operating range of the valve and reducing valve noise.

A further advantageous development of the valve according to claim 1 is achieved by the measures set forth in the subclaims, in which the above-mentioned configuration of the invention is characterized by a simple assembly and inspection, which is advantageous in terms of manufacturing technology of the valve. It can be improved and changed.

According to a particularly advantageous embodiment of the invention, the compression spring engages with its abutment end facing away from the valve closing body in a spring support which is mounted axially movably on the compression spring. As a result, the force of the compression spring in the valve closing direction can be adjusted in a simple manner by moving the spring receiver.

According to a further advantageous embodiment of the invention, an adjusting pin is displaceably mounted in the valve housing, the adjusting pin having a non-magnetic stop pin at its armature-side end; The pin has a stop protrusion towards the armature which forms a residual gap. With this configuration, the travel distance of the valve closing body can be adjusted to a desired length by axial movement of the adjustment pin without changing the residual gap.

According to a further advantageous embodiment of the invention, at least one flow hole passing through the wall of the nozzle holder is provided, through which the regulating device can be introduced. , the adjustment device allows the spring receiver to be moved in the axial direction for adjusting the spring force of the compression spring. According to this configuration, when the valve is finally assembled,
The spring force of the compression spring can be adjusted to produce the required closing force and the spring receiver can be fixed in the moved position.

According to a further advantageous embodiment, the corresponding spring retainer of the compression spring is pivotably mounted on a bearing surface of the valve closing body that is remote from the valve seat surface.

According to another advantageous embodiment, the armature is configured in the form of a bowl and is fastened to the coupling body, in which case the armature is mounted on the inside of its cylindrical annular wall opposite to the valve closing body side. A blind hole is formed on the side, and a coupling body enters into the blind hole with a large play, and the end of the coupling body on the opposite side from the valve closing body side is connected to the excitation coil. It serves as a tension surface during excitation. According to such a configuration, the stopper surface can be made small, which not only makes it possible to reduce the adhesion effect based on the so-called liquid force between the surfaces in contact with each other, but also makes it possible to reduce the adhesion effect when the excitation coil is energized. Impact loads on the mover can be prevented. This is because the armature itself no longer rests against any stop in the end position of its operation due to the arrangement described above.

According to a particularly advantageous embodiment of the invention, a non-magnetic stop pin is fixedly inserted on the coupling side in an adjusting pin which is movably mounted in the valve housing, and in which the excitation coil When energized, the coupled bodies come into contact with their coupled body end faces.

The invention will now be explained with reference to the illustrated embodiment.

Mixture compression - fuel injection system of spark ignition internal combustion engine,
The fuel injection valve exemplarily illustrated in FIG. 1 has a bowl-shaped valve casing l made of ferromagnetic material, in which an excitation coil 3 is arranged in a coil holder 2. There is. The excitation coil 3 is supplied with electricity from an electrical plug connection 4, which is connected to the bottom 9 of the valve casing l.
It is embedded in a plastic ring 5 which partially surrounds the. The coil holder 2 is located inside the coil chamber 6,
It is fitted onto a core 7 which projects from the bottom 9 of the valve housing l into the coil chamber 6 and which extends concentrically with respect to the longitudinal valve axis 8. At its open end, the valve housing I partially surrounds the nozzle holder 10 and is tightly connected thereto. The nozzle holder 10 has a through hole 11. In the through hole 11 of the nozzle holder 10, on the side opposite to the valve casing side, a nozzle body 12 having a step 13 is fitted and tightly connected to the nozzle holder 10, for example by brazing or welding. . The nozzle body 12 projects radially from the nozzle holder 10 with an abutment edge 14, on the upper side of which is provided an abutment edge 14 and a retaining ring 15, which is also fixedly connected to the nozzle holder. A packing ring 16 is arranged between them.

The nozzle body 12 has a conical valve seat surface 18 on the side of the through hole 11 of the nozzle holder IO, which in the first embodiment converges towards the bottom 19 of the valve' in the nozzle body 12. The bottom part 19 has one or more metering holes 20 which extend radially and tangentially at an angle to the longitudinal valve axis 8. . Metering hole 2
The fuel injection flow coming out from the bottom part 1 of the nozzle body 12
9 toward the wall of the air-fuel mixture preparation hole 21. Valve seat surface 18
In the closed state of the valve, the valve closing body 23 is in direct contact, and this valve closing body can have any suitable shape; There is a spherical section from the abutting part, followed by a truncated conical section, and then a cylindrical section, which is connected to the flange 24 and the support surface on the opposite side of the valve seat surface 18. It has 25. One end of a compression spring 26 is supported on the support surface 25 of the valve closing body 23 surrounding the collar 24,
This spring applies a spring load to the valve closing body 23 toward the valve seat surface 18 , and the abutting end 27 of the compression spring 26 on the side opposite to the valve closing body 23 is attached to the spring receiver 28 . This spring receiver is movably arranged in the through hole 11 of the nozzle holder 10. In this case the valve closing body 23
In order to adjust the closing force of the compression spring 26 against
The spring receiver 28 described above can be press-fitted into the through hole 11, for example, or it is also possible to provide a male thread on the outer periphery of the spring receiver 28 and screw it into the female thread of the through hole 11. After adjusting the spring force of the compression spring 26 lfJ, the spring receiver 28
is fixed in the through hole 11, for example, by caulking, brazing, welding, or the like. By doing so, the spring force of the compression spring 26 can be finely adjusted by the spring receiver 28 movably supported within the through hole 11. A flow hole 29 and a center hole 30 are formed in the spring receiver 28, passing through the spring receiver 28 in the axial direction, and the fuel can pass through these holes with almost no restriction. Valve closing body 23
An elongated coupling body 33 is inserted into the holding hole 32 and is fixedly coupled. This elongate connection can be made as a rod or tube (FIG. 2) and extends into the nozzle holder 10 with play in the center bore 30 of the compression spring 26 and spring receiver 28. The coupling body 33 passes through the compression spring 26 and the spring receiver 28 on the side opposite to the valve closing body 23 side, ends in the holding hole 34 of the movable element 35, and is immovably coupled to the movable element 35. There is. The bowl-shaped armature 35 is directed towards the core 7 and is guided in the radial direction by a guide hole 36 in the nozzle holder 10, which guide hole 36 forms, for example, a step into the through-hole 11. connected.

A flow hole 37 is provided in the mover 35 to allow fuel to pass along the inside and outside of the mover 35, and
A guide hole 3 is provided within the movable element 35 within the nozzle holder 10.
Flow grooves 38 are provided which are open towards 6 and allow fuel to flow from the outer layer of the mover 35 to the through hole 11.

The valve casing 1 has in the bottom part 9 and in the core 7 an adjusting hole 40 passing axially through these parts, in which an adjusting pin 41 made of a magnetically permeable material is movably supported. The adjustment pin 41 has a blind hole 42 at its end on the movable element 35 side, which is open toward the movable element 35, and a stopper pin 4 made of a non-magnetic material is inserted into this blind hole.
3 is fixed in place. A stopper protrusion 45 protrudes from an end surface 44 of the stopper pin 43 on the movable element 35 side, and its axial length defines a so-called residual gap. This is because the armature rests against the stop projection when the excitation coil 3 is in the energized state. At least a portion of the stopper protrusion 45 must be located outside the pin end surface 46 of the adjustment pin 41 when the stopper pin 43 is pressed into place. The axial distance between the armature 35 and the stop projection 45 when the excitation coil 3 is not energized represents the stroke of the armature or valve closing body 23;
By means of an axial movement of the adjustment pin 41, the above-mentioned stroke can therefore be adapted to the particular valve requirements without changing the residual gap. After adjusting the stroke, the adjusting pin 41 is fixed in the adjusting hole 40, for example by caulking or similar means.

The adjustment pin 41 is in this case operated through a stepped adjustment hole 49 in the plastic ring 5. After the adjustment process is completed, the adjustment hole 49 is easily closed by the locking cap 50.

This locking cap 50 is made of an elastic material,
During assembly, the plastic ring 5 is locked into the corresponding locking opening. The locking cap 50 is provided with an adjustment hole 49 and a ventilation hole 51 communicating with the atmosphere.

The fuel injection valve is supplied with fuel through an inlet hole 53 which penetrates the tubular wall of the valve housing 1 and opens into the coil chamber δ. The supply of fuel to the inlet hole 53 is performed by a fuel pressure source, for example a fuel feed pump. An annular groove 54 is formed between the wall of the coil chamber 6 and the outer circumferential surface of the coil holder 2, through which the fuel can flow downwards and then radially into the flow groove 3.
8 and from there to the through hole 11, reaching the valve seat surface, from where it is injected via the metering hole 20 when the valve is opened. The inflow opening 53 can be surrounded by a filter body 55 which is seated in the valve housing l and whose filter area surrounds the opening of the inflow opening 53 .

The filter body 55 also has a packing ring 56 between the filter body 55 and the plastic ring 5.
It also serves to maintain the axial position relative to the valve casing l.

of the movable element 35. Stopper protrusion 45 of stopper pin 43
A stop disk 58 is fitted on the side, which, like the stop pin 43, is made of as hard a material as possible.

In a second embodiment of the valve according to the invention, partially illustrated in FIG. 2, identical and identically functioning parts are designated with the same reference numerals. In this case, the embodiment shown in FIG. 2 differs from the embodiment shown in FIG.
It is guided and fixed inside. Furthermore, in the embodiment shown in FIG. 2, a fuel supply hole 53 is located in the nozzle holder 10, and a guide hole 36 and a flow groove 38 are formed in the valve casing l.

In the embodiment of FIG. 3, parts that are the same as those of the previous embodiments and have the same functions are designated by the same reference numerals. In contrast to the previous embodiments, the embodiment according to FIG. 3 differs in this case in that the nozzle body 12 extends with a tubular extension 61 in the direction of the valve housing l or the nozzle holder 10. The tubular extension 61 of the nozzle body 12 has a fixing hole 62, one end of which transitions into the valve seat surface 18 and the other end of which is open to the nozzle holder 10.
The tubular extension flls 61 extends into the through hole ll of the valve housing l or the nozzle holder 10 and is fixedly connected thereto. A spring holder 28 is movably mounted in the fixing hole 62 of the tubular extension 61, which spring holder 28 can be made from sheet metal in accordance with the embodiment according to FIG. can be fixed in the fixing hole 62 after adjusting the spring force of the compression spring 26. In this embodiment, therefore, the valve closing body connected to the coupling body 33 and the armature 35 can be inserted in a simple manner into the nozzle body 12, in which case the compression spring 26 and the spring receiver 28
can be inserted onto the coupling body 33 in advance. The spring receiver 28 is then moved within the fixing hole 62 until the desired spring force of the compression spring 26 is achieved. After this, the spring receiver 28 is fixed to the tubular extension 61.

In the embodiment of FIG. 4, parts which are identical to the previous embodiments and which have the same function are designated by the same reference numerals.In this case, in contrast to the embodiment of FIGS. 1 and 2, the adjusting pin 41 is simply It is mounted movably only in an adjustment bore 40 in the bottom 9 of the valve housing l. In this case, the adjusting pin 41 by itself fulfills the function of the core completely. The excitation coil 3 together with the coil holder 2 directly surrounds this adjusting pin 41 . The cylindrical wall of the valve housing l has at least one flow hole 64 serving as an outlet hole, which flow hole is surrounded from the outside by a filter body 55 and on the inside, the coil holder 2 is It is connected to the surrounding annular groove 54.

The cylindrical annular wall of the bowl-shaped mover 35 faces toward the #1 node pin 41 and has a blind hole 65 formed inside, into which the combined body 33 is inserted with a large play. ing. The end surface 66 of this combined body 33 is connected to the stopper pin 43.
It directly faces the stopper protrusion 45 and ends near the movable end face 67, so that when the excitation coil is excited and the combined end face 66 abuts the stopper protrusion 45, the pin end face 46 and A sufficiently large residual gap is formed between the movable element end face 67 and the movable element end face 67. For this purpose, it can be provided that the coupling end face 66 lies inside or outside the blind hole 65 or in the plane of the armature end face 67. The fastening of the armature 35 to the coupling body 33 can be carried out by forcing the material of the armature into the illustrated annular groove of the coupling body 33.

The through hole 11 of the nozzle body 12 is stepped, and the diameter immediately adjacent to the movable element 35 is smaller than the diameter adjacent to the spring receiver 35.

The guiding of the armature 35, however, takes place by means of a guide disk 68, which is arranged, for example, in a snap-in hole 69 in the end of the nozzle holder IO on the side of the valve housing I and is secured by a caulking s70. Mover 35
moves in a guide hole 71 of the guide disk 68, which can have a longitudinal groove (not shown), so that the through hole 11 in the nozzle holder 10 and the valve casing l
A fuel passage is formed between the inner annular groove 54 and the inner annular groove 54 .

A flow hole 73 is provided in the wall of the nozzle holder IO, which serves as a fuel inlet hole, and which serves as a fuel inlet hole.
8 opens into the through hole 11 on the side opposite to the valve closing body 23 side. , in this embodiment, the compression spring 26 is directly connected to the valve closing body 2
3, but rests on a corresponding spring support 74, which is pivotably mounted on a bearing surface 75 of the valve closing body 23 opposite the valve seat surface 18. For this purpose, the mutually contacting surfaces of the corresponding spring receiver 74 and the bearing surface 75 can be made in a suitable shape, for example spherical. In order to adjust the spring force of the compression spring 26 to the required spring force, an adjusting device 76 in the form of a pin is inserted into the flow hole 73 provided in the nozzle holder 10 and as shown in the right hand part of FIG. Then, one of the spring receivers 28 can be engaged with the end face 77 and the spring receiver 28 can be moved to a point where the desired spring force of the compression spring 26 can be changed. However, as shown in the left half of FIG.
8 may be provided, and an adjusting device 76 configured in the shape of a hook for adjusting and moving the spring receiver 28 may be engaged in the engaging groove 78 . In this embodiment, the adjusting device 76 is then withdrawn again from the flow hole 73 and the spring receiver 28 is removed, for example by swiveling the wall material of the nozzle holder 10 radially into the groove of the spring receiver 28. Can be fixed. Although not shown in the drawings, it is also possible to manufacture the through hole 11 as a female threaded hole and to manufacture the lever spring receiver 28 with a male thread so that the same axial displacement can be changed by rotating the spring receiver 28. .

All embodiments have the same advantages as follows.

That is, the compression spring 26 does not exert its spring force on the coupling body 33, so that the cross section of the coupling body 33 as a rod or tube can be made significantly smaller than in known valves, so that The mass of the combined body 33 can be reduced. Due to the fact that the mass of the combination body 33 can be reduced according to the invention, the valve closing body 23, the combination body 3
The mass of the movable part of the valve consisting of the valve 3 and the mover 35 is also reduced, resulting in extremely rapid opening and closing operations of the valve and reduced valve noise.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a first embodiment of a valve constructed according to the present invention, and FIGS. 2 and 3 are partial views showing second and third embodiments of a valve constructed according to the present invention. FIG. 4 is a diagram showing a fourth embodiment of a valve constructed according to the present invention. l... Valve casing, 2... Coil holder, 3...
・Exciting coil, 4...Plug-in connection part, 5...Plastic ring, 6...Coil chamber, 7...Core, 8...
・Valve vertical axis, 9...bottom, 10...nozzle holder,
11... Through hole, 12... Nozzle body, 13...
Stepped portion, 14...Abutting edge, 15...Retaining ring, 1
6...Packing ring, 18...Valve seat surface, 19...
・Bottom, 20... metering hole, 21... mixture adjustment hole,
23... Valve closing body 24... Tsuba, 25... Support surface,
26... Compression spring, 27... Contact end, 28...
Spring receiver, 29...; Flow hole, 30... Center hole, 3
2... Holding hole, 33... Combined body, 34... Holding hole, 35... Mover, 36... Guide hole, 37... Flow hole, 38... Flow groove , 40...adjustment hole, 41...
- Adjustment pin, 42... Blind hole, 43... Stopper pin, 44... End face, 45... Stopper protrusion, 46.
... End face, 49 ... Adjustment hole, 50 ... Locking cap, 51 ... Ventilation hole, 53 ... Inflow hole, 54 ... Annular groove, 55 ... Filter body, 56 ...・Patsukin ring, 58...Stopper disc, 60...Color 6
DESCRIPTION OF SYMBOLS 1... Tubular addition part, 62... Fixing hole, 64... Flow hole, 65... Blind hole, 66... Combined body end surface, 67...
...Mover end face, 68...Guide disk, 69...
Fitting hole, 70... caulking part, 71... guide hole,
73...Flow hole, 74...Corresponding spring receiver, 75...
・Supporting surface 76... Adjustment device, 77... Spring receiver is end face, 78... Engagement groove

Claims (16)

[Claims] 1. A solenoid valve having a valve casing, a core surrounded by an excitation coil, a valve seat surface provided in a nozzle body, and a valve closing body cooperating with the valve seat surface, the valve closing body In the type in which the body is connected to the mover via an elongated coupling body and is spring-loaded in the direction of the valve seat surface by a compression spring surrounding said coupling body, the compression spring (2
A solenoid valve characterized in that 6) acts by engaging the valve/closing body (23) directly or via a corresponding spring support (74). 2. A compression spring (26) is connected to the valve closing body (26) of the compression spring (26).
23), the abutting end opposite to the side 23) engages and acts on a spring receiver (28) which is movably supported in the axial direction of the compression spring (26). The solenoid valve described in item 1. 3. 3. Solenoid valve according to claim 2, characterized in that the spring receiver (28) is seated in a through hole (11) of a nozzle holder (10) connected to the nozzle body (12). 4. 3. Solenoid valve according to claim 2, characterized in that the spring receiver (28) is supported upstream of the valve seat surface (18) in the through hole (62) of the nozzle body (12). 5. 3. Solenoid valve according to claim 2, characterized in that the spring catch (28) is made from sheet metal. 6. 3. Solenoid valve according to claim 2, characterized in that the spring receiver (28) has a center bore (30) into which the elongated coupling body (33) is inserted with play. 7. 3. Solenoid valve according to claim 1, characterized in that the elongate connection (33) is constructed as a rod. 8. 3. Solenoid valve according to claim 1, characterized in that the elongate connection (33) is constructed as a tube. 9. 2. Solenoid valve according to claim 1, characterized in that the armature (35) has a bowl-shaped design. 10. the valve casing (1) has an adjustment hole (40);
A magnetically permeable adjustment pin (41) is movably supported in the adjustment hole, and the adjustment pin has a blind hole (42) at the end on the movable element (35) side. A stopper protrusion (forming a residual gap) in which a non-magnetic stopper pin (43) is immovably fitted and protrudes toward the movable element (35) and outside the blind hole (42). 45)
The electromagnetic valve according to claim 1, characterized in that it has a. 11. At least one flow hole (73) is provided in the wall of the nozzle body (10) through which a regulating device (76) can be introduced, the adjusting device (76) passing through the wall of the nozzle body (10).
3. Solenoid valve according to claim 2, characterized in that by means of 6) the spring receiver (28) is axially movable in order to adjust the spring force of the compression spring (26). 12. Claim 1: The counter spring support (74) is pivotably mounted on a bearing surface (75) of the valve closing body (23) opposite the valve seat surface (18). Solenoid valve. 13. A blind hole (65) in which the cylindrical annular wall of the bowl-shaped mover (35) opens on the side opposite to the valve closing body (23) side.
is formed inside the hole, and a coupling body (33) enters the hole with a large play, and the valve closing body (33) of the coupling body enters the hole with a large play.
10. Solenoid valve according to claim 9, characterized in that the coupling end face (66) opposite to the side 23) serves as a stop surface when the excitation coil (3) is energized. 14. The valve casing (1) has an adjustment hole (40) in which a magnetically permeable adjustment pin (41) is movably supported, with a bag at its armature-side end. Hole (
42), and a non-magnetic stopper pin (
14 . 14 . 14 . 14 . 14 . 14 . solenoid valve. 15. 15. The electromagnetic valve according to claim 14, wherein the stopper pin (43) projects from the blind hole (42) toward the coupling body (33). 16. The stopper pin (43) is on the joint body (33) side,
A stopper protrusion (45) protruding to the outside of the blind hole (42)
The electromagnetic valve according to claim 15, characterized in that it has a.