JPH0326867A - Fuel injection valve - Google Patents

Abstract

PURPOSE:To prevent the generation of error in fuel metering and prevent fuel leak and reduce the production cost by forming a plunger and a valve into spherical form and fixing them integrally by a joint. CONSTITUTION:A plunger 5A and a valve 7 are formed into spherical form, and fixed integrally by a joint 16. With this constitution, even if the center of the inner wall surface of a yoke 3 for slide-supporting the plunger 5A and the core of the inner wall surface of a nozzle 6 for slide-supporting the valve 7 deflect, automatic center adjustment in movable manners in the vertical direction along the inner wall surfaces is permitted, since the plunger 5A and the valve 7 connected by the joint 16 are formed into spherical form, and the vertical operation is not obstructed. Therefore, the error in metering fuel due to the operation disorder of the plunger 5A and the valve 7 and the generation of troubles such as fuel leak due to the sealing disorder are prevented. Further, the cost in working parts such as the yoke 3 and the nozzle 7 and the assembly cost of the body can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection valve, and particularly to a high performance and inexpensive fuel injection valve.

[Prior art] A conventional fuel injection valve will be explained using drawings.

FIG. 4 is a sectional view showing a conventional injection valve. As shown in this figure, the fuel injection valve 1 includes a core 2, a coil 4, a yoke 3, a plunger 5 that is slidably supported on the inner wall surface of the yoke 3, and a nozzle 6. A valve 7, a swirl orifice 8, and a swirl orifice 8, which are slidably supported on the inner wall surface of the plunger 5 and are integrally attached to the plunger 5. L7■ consisting of an orifice 9 provided on the opposite side of the plunger, the valve 7, and the nozzle 6.
A twisted pair consisting of the seat surface of the valve 7 formed in
It has L chicks. In other words, this fuel injection valve 1. A cylindrical plunger 5 and a spherical valve 7, which are integrated, are connected to a yoke 3 on one side (plunger 5).
The nozzle 6 is slidably supported by the inner wall surface of the nozzle 6 on the other (valve 7) side. In other words, it is constructed such that the cylindrical body slides on the inner wall surface of the cylindrical body and the spherical body slides on the other inner wall surface of the integral part made up of a cylindrical body and a spherical body.

In the fuel injection valve 1 configured as described above, when the coil 4 is energized, the plunger 5 is attracted toward the core 2 side, so that the valve 7 also moves toward the core 2 side.

When the valve 7 moves to the core 2 side in this way, the valve 7
is separated from the seat surface of the nozzle 6, a gap is formed there, and fuel flows in from the filter 10 and the fuel passage 1,
After passing through the gap, the fuel reaches the fuel guide hole 8a opened in the swirl orifice 8. A plurality of fuel guide holes 8a are formed so as to have a certain angle with respect to the horizontal direction and to contact the rod-shaped member 12a disposed in the thin chamber l2, so that the fuel can flow through the fuel guide holes 8a. Pivoting motion is provided by hole 8a. Further, this fuel is atomized in the thin chamber 12, the spray angle is optimized, and the fuel is injected from the orifice 9 in the form of a mist.

Note that related fuel injection valves of this type include, for example, Japanese Patent Application Laid-Open No. 60-35169.

[Problems to be Solved by the Invention] In the above prior art, the cylindrical plunger 5 and the spherical valve 7 are integrated, and one side (the plunger 5) is connected to the inner wall surface of the yoke 3 on the other side (the valve 7). On the 7) side, the nozzle 6 is slidably supported by the inner wall surface of the nozzle 6, so that the core of the inner wall surface of the yoke 3 that slides and supports the plunger 5 and the nozzle that slides and supports the valve 7. 6
Even if there is a misalignment between the center of the inner wall surface of
If there is misalignment between the plunger 5 and the valve 7, it will interfere with the vertical movement of the plunger 5 and the valve 7, which are integrated, and cause an error in the fuel measurement by the fuel metering section, or The seal on the seat surface became unreliable, causing problems such as fuel leakage. In order to prevent these problems, ■Drilling holes to ensure the coaxiality of the sliding support inner wall surface of the plunger 5 based on the outer diameter of the yoke 3, and ■Drilling the valve 7 based on the outer diameter of the nozzle 6. High-precision drilling ensures coaxiality of the sliding support inner wall surface, ■ High-precision plunger 5 and valve 7 are integrally molded. ■There was a problem in that the yoke 3, plunger 5, and nozzle 6 had to be assembled with high precision, resulting in a significant increase in production costs.The present invention solves the problems of the prior art described above. The purpose is to provide a fuel injection valve that does not cause errors in fuel metering, does not cause fuel leakage, and is inexpensive to manufacture. [Means for Solving Problem 1l] In order to solve the above problems, the structure of the fuel injection valve according to the present invention includes a magnetic circuit, a fuel injection circuit, and a fuel metering section, and The circuit includes a core, a coil, a yoke, and a plunger that slides on the inner wall of the yoke.
The fuel injection circuit includes a nozzle, a valve that slides on the inner wall surface of the nozzle and is connected or integrated with the plunger, and an orifice provided on the side opposite to the plunger of the valve. The fuel metering section is made up of the valve and a seat surface of the valve formed on the nozzle, and by energizing the coil, the plunger is attracted toward the core and the valve is connected to the valve. In the fuel injection valve, a gap is formed between the plunger and the valve, and the fuel injected into the upstream side of the gap can be injected from the orifice via the gap. The shapes of the plunger and the valve are made spherical, and they are fixed together by a joint, or the plunger and the valve are connected by a joint that allows relative rotation between the two, or the plunger part and the valve part are made spherical in shape. These are formed into a single piece in the shape of a "balloon" that envelops both of the spherical surfaces.

[Function] By making the plunger and the valve into separate spheres and fixing them by a joint, or by making them into one piece, even if the inner wall surface of the yoke that slidingly supports the plunger and the valve are Even if the coaxiality and concentricity of the inner wall surface of the nozzle that is being slidably supported is not ensured, since the plunger and valve are spherical, their vertical movement will not be hindered. Therefore, errors in fuel metering will not occur, and problems such as deterioration of valve seat performance will be avoided.

Furthermore, even if the plunger and the valve are connected by a joint that allows relative rotation between the two, the inner wall surface of the yoke that slides and supports the plunger and the valve may Even if the coaxiality and concentricity of the inner wall surface of the nozzle being slidably supported is not ensured, the plunger and the valve are rotatable relative to the joint, so their vertical movement is not hindered.

〔Example] Hereinafter, the present invention will be explained by examples.

FIG. 1 is a sectional view showing a fuel injection valve according to a first embodiment of the present invention. The outline of this fuel injection valve will be explained using Fig. 1.
This has a magnetic circuit, a fuel injection circuit, and a fuel metering section, and the magnetic circuit includes a core 2, a coil 4, a yoke 3, and the yoke 3. The fuel injection circuit includes a plunger 5A (details will be described later) that slides on the inner wall surface of the nozzle 6, and the plunger 5A that slides on the inner wall surface of the nozzle 6.
A valve 7 (details will be described later) integrated with A, and an orifice 9 provided on the anti-plunger side of this valve. and a sheet surface 6a of the coil 4.
By energizing the plunger 5A, the plunger 5A is drawn toward the core, a gap is formed between the valve 7 and the seat surface 6a, and the fuel press-fitted into the upstream side of this gap is passed through the gap. The fuel injection valve IA is capable of injecting fuel from the orifice 9, and the plunger 5A and valve 7 are spherical in shape and are integrally fixed by a joint 16. This will be explained in detail below. This fuel injection valve IA has a magnetic circuit composed of a core 2, a yoke 3, a coil 4, a plunger 5A, etc., and a nozzle 6.
A fuel injection circuit is constituted by a valve 7 disposed inside, a swirl orifice 8 and an orifice 9 formed in the nozzle 6, and the like. A valve 7 is connected to the plunger 5A through a joint 16. A bobbin ↓5 is fitted around the outer periphery of the core 2, and a coil 4 is wound around this bobbin 15. A terminal 20 and a lead wire 19 are wired inside the coupler 21 attached to the flange 22, and this lead wire 19 is connected to the coil 4.
Therefore, when the terminal 20 is energized, the plunger 5
A is attracted to the core 2 side, and the valve 7 also moves upward,
It hits stopper 14. Therefore, a gap is formed between the valve 7, which was pressed against the lower seat surface 6a by the spring t8, and the seat surface 6a before energization, and the fuel is supplied to the fuel supply sealed by the O-rings 17a and 17b. From the gallery (not shown), it passes through the filter 10, is press-fitted into the main body via the supply port 3a provided in the yoke 3, and further flows to the fuel passage 11 and swirl orifice 8, and flows through the gap. It passes through and is injected from orifice 9. An O-ring 17c is arranged between the core 2 and the yoke 3 to prevent fuel leakage.

Further, this fuel injection valve IA is attached to the fuel gallery using the attachment hole 23 of the flange 22. With this structure, even if the center of the inner wall surface of the yoke 3 that slides and supports the plunger 5A is misaligned with the center of the inner wall surface of the nozzle 6 that slides and supports the valve 7, the plunger 5A and the valve 7 connected to the plunger 5A by the joint 16 are both spherical, so the plunger 5A and the valve 7 are self-aligned so that they can move up and down along their respective inner wall surfaces. can be used without interfering with its vertical movement.

According to the embodiment described above, problems such as fuel measurement errors due to malfunction of the plunger 5A and valve 7, and fuel leakage due to seal failure do not occur. In addition, the concentricity of the center of the inner wall surface of the yoke 3 that slides and supports the plunger 5A and the center of the inner wall surface of the nozzle 6 that slides and supports the valve 7, and the degree of coaxiality of each are determined with high accuracy. Since there is no need to secure the yoke 3, the nozzle 7, etc., and the assembly cost of the main body, it is possible to reduce the cost.

Other embodiments will be explained below. The second @ is a sectional view showing a fuel injection valve according to a second embodiment of the present invention. In this 21i1, the same parts as those in FIG. 1 are denoted by the same numbers.

This fuel injection valve IB is different from the embodiment shown in FIG. 1 in the plunger and valve configurations, and the plunger portion 5a and valve portion 7a are spherical in shape. These are made into a plunger valve 25 that is a "gourd"-shaped integral part that envelops both of the spherical surfaces.

With this structure, the core of the inner wall surface of the yoke 3 that slides and supports the upper spherical plunger portion 5a of the plunger valve 25 and the nozzle 6 that slides and supports the lower spherical valve portion 7a. Even if the inner wall surface is misaligned, the vertical movement of the plunger valve 25 is not hindered.

According to this embodiment, problems such as fuel metering errors due to malfunction of the plunger valve 25 and fuel leakage due to seal failures do not occur. Also, plunger valve 2
The inner wall surface of the yoke 3 slidingly supports the upper spherical surface of the yoke 5,
There is no need to maintain concentricity and coaxiality with the inner wall surface of the nozzle 6, which slides and supports the lower spherical surface, through high-precision machining and assembly, which has the effect of reducing manufacturing costs. Furthermore, since the plunger portion 5a and the valve portion 7a are directly joined without using a joint, there is an advantage that the plunger valve 25 can be made smaller and the overall length of the fuel injection valve 1B can be shortened. .

FIG. 3 is a sectional view showing a fuel injection valve according to a third embodiment of the present invention.

In FIG. 3, the same parts as in FIG. 1 are denoted by the same numbers.

Similar to the first embodiment, this fuel injection valve IC is constructed by connecting a plazoja 5B and a valve 7B with a joint 16B. only part of the spherical surface,
Plunger 5B is a cylindrical body. The plunger 5B is connected to the joint 16B and the pin 19a.
The valve 7B is held rotatably in the rotational direction with the pin 19a as the rotation axis, and the valve 7B is similarly held by the pin 19b disposed perpendicularly to the pin 19a.
It is held rotatably in the direction of rotation with the axis of rotation. With this configuration, the plunger 5B and the valve 7
Because B is rotatable with respect to the joint 16b. The core of the inner wall surface of the yoke 3 that slides and supports the plunger 5B,
The valve 7B can be moved up and down regardless of the degree of concentricity with the center of the inner wall surface of the nozzle 6 that supports the valve 7B in a sliding manner. Therefore, the vertical movement of the plunger 5B and the valve 7B is not hindered.

According to the embodiment described above, problems such as fuel measurement errors due to malfunctions of the plunger 5B and valve 7B, and fuel leakage due to seal failures do not occur. In addition, there is no need for high accuracy in parts processing and assembly.
It also has the effect of lowering manufacturing costs. C. Effects of the Invention] As described above in detail, according to the present invention. It is possible to provide a fuel injection valve that does not cause errors in fuel metering, does not cause fuel leakage, and is inexpensive to manufacture.

[Brief explanation of drawings]

1 to 3 are cross-sectional views showing fuel injection valves according to first to third embodiments of the present invention, and FIG. 4 is a cross-sectional view showing a conventional fuel injection valve. LA, IB, Ic...Fuel injection valve, 2...Core. 3.
...Yoke, 4...Coil, 5A, 5B...Plunger, 5a...Plunger part, 6...Nozzle, 6
a... Seat surface, 7, 7B... Valve, 7a...
Valve part. 9. Orifice, ↓6, 16B...Joint, 25...Plunge valve.

Claims (1)

[Scope of Claims] 1. It has a magnetic circuit, a fuel injection circuit, and a fuel metering part, and the magnetic circuit has a core, a coil, a yoke, and a plunger that slides on the inner wall surface of the yoke, The fuel injection circuit includes a nozzle, a valve that slides on the inner wall surface of the nozzle and is connected or integrated with the plunger, and an orifice provided on the side opposite to the plunger of the valve, and the fuel metering section includes , consisting of the valve and a seat surface of the valve formed on the nozzle, and by energizing the coil, the plunger is attracted toward the core and the gap between the valve and the seat surface is In the fuel injection valve, the plunger and the valve are spherical in shape, and the fuel injected into the upstream side of the gap can be injected from the orifice through the gap. , a fuel injection valve characterized in that these are integrally fixed by a joint. 2. It has a magnetic circuit, a fuel injection circuit, and a fuel metering part, the magnetic circuit has a core, a coil, a yoke, and a plunger that slides on the inner wall surface of the yoke, and the fuel injection circuit has: a nozzle, a valve that slides on the inner wall surface of the nozzle and is connected or integrated with the plunger, and an orifice provided on the side opposite to the plunger of the valve; a seat surface of the valve formed on a nozzle, and by energizing the coil, the plunger is attracted toward the core and a gap is formed between the valve and the seat surface; In the fuel injection valve, the fuel press-fitted into the upstream side of the gap can be injected from the orifice via the gap, and the plunger and the valve are capable of relative rotation therebetween. A fuel injection valve characterized by being connected by a joint. 3. It has a magnetic circuit, a fuel injection circuit, and a fuel metering section. The magnetic circuit includes a core, a coil, a yoke, and a plunger that slides on the inner wall surface of the yoke, and the fuel injection circuit includes a nozzle, slides on the inner wall surface of the nozzle, and is connected or integrated with the plunger. and an orifice provided on the opposite side of the valve to the plunger, the fuel metering section comprising the valve and a seat surface of the valve formed in the nozzle, and the coil By energizing the plunger, the plunger is attracted toward the core, a gap is formed between the valve and the seat surface, and the fuel press-fitted into the upstream side of this gap is passed through the gap to the In a fuel injection valve capable of injecting fuel from an orifice, the plunger portion and the valve portion are spherical in shape, and these are formed into a single piece in the shape of a “balloon” that envelops both spherical surfaces. Characteristic fuel injection valve.