JPS62150069A - Solenoid type fuel injection valve - Google Patents

Abstract

PURPOSE:To make it possible to maintain a valve opening action time and a valve closing action time constant by forming a spherical surface on either one of contact surfaces of a fixed side stopper or a movable side stopper and by making the fixed side stopper slidable when it contacts the movable side stopper. CONSTITUTION:A valve body 11 is moved up by electromagnetic attraction of a stator 8 and an armature 9 and its lift amount is restricted by the contact of a movable side stopper 13 against a fixed side stopper 12 and a valve part 110 moves off a sear 35 to inject fuel present in a fuel collection groove 350 out of an injection hole 30. Here, since the lower end contact surface of the fixed side stopper 12 is conical and the contact surface of the movable side stopper 13 is spherical, they come into a circular contact with each other, and the fixed side stopper 12, due to impact forces of the contact, immediately inches while sliding along the movable side stopper 13, and is again pressed against an inner wall of a body 3 with a conical ring spring 14. Thus, it is made possible to maintain a valve opening action time and a valve closing action time constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic fuel injection valve that injects fuel into an internal combustion engine under electronic control.

[Conventional technology]

A conventional fuel injection valve of this type has a configuration as shown in FIG.

In the electromagnetic fuel injection valve l, a housing 2 with both ends open and a body 3 with an injection hole 30 formed at the end have a stepped cylindrical shape, and both are integrated by bending the lower end of the housing 2. are connected to each other. The body 3 has a large diameter portion 31 that is connected to the inner small diameter portion 21 of the housing 2.
The small diameter portion 32 of the body protrudes from the lower end of the housing 2, and a sleeve 4 having a sleeve 40 communicating with the injection hole 30 is fixed to the outer periphery of the body 3.

A coil 5 disposed in the inner large diameter portion 22 of the housing 2 is connected to a computer 7 via a terminal 6. A cylindrical stator 8 is disposed inside the coil 5, and an armature 9 disposed opposite the stator 8 is biased in a direction away from the stator 8 by a spring IO provided inside the stator 8. Armature 9 is valve body work 1
, and forms a gap with the inner wall of the intermediate portion 23 between the inner large-diameter portion 22 and the small-diameter portion 21 of the housing 2 .

A horseshoe-shaped stationary stopper 12 through which the valve body 1) passes through the central portion is fitted between the end wall surface of the internal small diameter portion 21 of the housing 2 and the end of the body 3. There is. On the other hand, a flap-shaped movable stopper 13 is integrally formed on the valve body 1).

Note that the fixed side stopper 12 and the movable side stopper 1
The contact surface of No. 3 is a flat surface.

The operation of the above configuration will be explained.

Now, when an electric signal is supplied from the computer 7, the coil 5 generates electromagnetic force. Then, the armature 9 is integrated with the valve body 1) and is attracted toward the stator 8 against the pressing force of the spring 10. The valve body 1) slides smoothly inside the body 3 to open the injection hole 3o at the end of the body 3. At this time, the amount of lift of the valve body 1) is regulated by the movable stopper 13 coming into contact with the fixed stopper 12.

However, such an electromagnetic fuel injection valve has a problem in that the fixed stopper 12 and the movable stopper 13 do not abut in parallel. This is because the machining accuracy and assembly accuracy when installing the stopper 13 cannot be sufficiently increased, and the pressing force of the spring 10 and the suction force due to electromagnetic force are completely aligned with the axial direction of the valve body 1). This is because it is not possible.

As mentioned above, the fixed side stopper 12 and the movable side stopper 1
If 3 and 3 do not make plane contact, that is, if either one contacts the other at the corner, the following problem will occur.

Generally, when the movable stopper 13 comes into contact with the fixed stopper 12, the fuel present between the opposing surfaces is compressed, so that a buffering force is generated based on the viscous force of the fuel.

On the other hand, even when the stoppers 12 and 13 are separated, adhesion force due to the viscous force of the fuel is generated.

The above-mentioned buffering force and adhesion force are
It is proportional to the area facing each other and inversely proportional to the cube of the gap length. Therefore, when the stoppers 12 and 13 come into contact at the corners as described above, the opposing area is small and the gap length is large, so the buffering force becomes very small and the stoppers 12 and 13 collide violently. Therefore, the contact portion is subject to significant wear. Further, when the stoppers 12, 13 are separated due to the return of the valve body 1), the return is quickly carried out because the adhesion force is small, in other words, the valve closing operation time can be shortened.

However, as the wear of the corners progresses, the opposing area increases, the gap length decreases, and the buffering force and adhesion force increase. Therefore, the resistance force when the stoppers 12 and 13 are separated increases, and the valve closing operation time becomes longer.

When both stoppers 12 and 13 come into contact at the corners in this way,
As it is used, the initially set valve closing operation time gradually increases, resulting in a drawback that the amount of injection from the injection hole 30 fluctuates.

In order to eliminate the above-mentioned drawbacks, Japanese Patent Application Laid-Open No. 58-70049 proposes that even if the fixed stopper 12 and the movable stopper 13 face each other in non-parallel positions, they will not touch each other. The movable stopper 13 slides as soon as the valve starts, and in order to keep both the stoppers 12 and 13 always in parallel contact, a spring member is interposed so that the movable stopper can swing freely relative to the valve body. The structure is such that it is attached to a movable part.

[Problem that the invention seeks to solve]

However, in the electric Tff type fuel injection valve having the structure according to Japanese Patent Application Laid-Open No. 58-70049, the abutment surfaces between the movable stopper and the fixed stopper still have a flat planar shape. Here, as mentioned above, the buffering force and adhesion force due to the viscous force of the fuel existing between both stoppers is proportional to the opposing area of both stoppers, and varies inversely proportional to the cube of the gap length. It is desirable that the same planes of both stoppers come into contact with each other each time the valve is actuated.

Nevertheless, with the above configuration, it is possible to avoid the contact of the corners, but from the time the movable stopper starts touching the fixed stopper until it becomes parallel to the fixed stopper, the movable stopper has no contact with the fixed stopper. It swings on the valve body while rubbing the contact surface and another adjustment surface. In this way, the movable stopper must rub two surfaces before it becomes parallel to the fixed stopper, and therefore, it was not possible to completely abut both surfaces in the case of Shun. Furthermore, the time required for complete contact each time was likely to vary.

Due to this time difference, the valve opening time is not constant each time, and the movable stopper swings or rotates on the valve body, so if the valve is used repeatedly,
As the positions of the opposing surfaces shift relative to each other during abutting, the wear condition of the abutting surfaces and the opposing areas during abutting change, causing the adhesion force to fluctuate and, therefore, the valve closing operation time to change as well. A situation arose.

For example, in particular, No.
If the fixed side stopper and the movable side stopper are both horseshoe-shaped as in the embodiment shown in Figures 8 to 8, the movable side stopper will swing or rotate around the valve body, and the notch of the fixed side stopper will move around the valve body. Since the stoppers often overlap with each other in the notch, the opposing areas of the two stoppers vary greatly.

In this way, if the contact between the two stoppers is made surface-to-surface, it is not only difficult to achieve a state of contact in which the two surfaces are completely parallel, but also as described in Japanese Patent Laid-Open No. 58
-Even if it is possible to achieve perfectly parallel contact according to No. 70049, as mentioned above, when the two surfaces are in contact, the valve opening and closing operation times will fluctuate, causing the fuel injection amount to change. There is. In addition, the structure was complicated because the spherical surfaces were used for fine adjustment by abutting the two surfaces, and the excellent abutting properties of the spherical surfaces were only indirectly utilized.

The present invention has been made in view of the above-mentioned conventional problems, and eliminates the conventional surface-to-surface contact between the two stoppers and maintains a stable contact state even after long-term use of the valve. It is an object of the present invention to provide a fuel injection valve that can easily achieve a contact that can be maintained.

[Means for solving problems]

In order to solve the above problems, the present invention provides an electromagnetic fuel injection valve including: a movable part having a valve part for metering fuel and a movable stopper; a fixed part fixed in a housing; a movable-side stopper provided on the moving part; a fixed-side stopper provided on the fixed part and regulating the lift ffi of the movable part due to contact with the movable-side stopper; the fixed-side stopper and the fixed part; a spring member interposed between the fixed side stopper and the movable side stopper, a spherical surface being formed in the abutting portion of either the fixed side stopper or the movable side stopper, and when the fixed side stopper abuts the movable side stopper. The structure is characterized in that the tz can be freely moved.

[Effect]

With the above configuration, the movable part lifts,
When the movable stopper abuts the fixed stopper, the fixed stopper provided on the fixed part via the spring member slides on the surface of the movable stopper via the spherical surface and comes into contact with the movable stopper. A part of the inner periphery on the spherical surface becomes a contact line, and the above-mentioned problem caused by instability caused by contact between the surfaces can be solved.

[Example] Hereinafter, an example according to the present invention will be described, but only the main parts will be explained and other configurations similar to the conventional one will be omitted.

A first embodiment will be explained using FIG. 1.

In the electromagnetic fuel injection valve 1, a body 3 serving as a fixed portion is fixed by bending the lower opening end of a housing 2 made of a magnetic material. This body 3 has a stepped cylindrical shape, and is fixed to the inner small diameter portion 21 together with a spacer 24 sandwiched between the upper end surface of the large diameter portion 31 and the upper end wall surface of the inner small diameter portion 21 of the housing 2. The body small diameter portion 32 projects outward from the lower end of the housing 2. Furthermore, a cylindrical guide 33 is fixed to the inner wall surface of the body 3, and its upper end is in contact with the spacer 24.

At the bottom of the guide 33, a bolt-shaped fixed stopper 12 having a notch in the axial direction and having a large diameter part and a small diameter part is pressed against the lower end surface of the guide 33 via a disc spring 14 as a spring member. There is. The disc spring 14 has one end in contact with the upper surface of a central portion 34 where the inner diameter of the body 3 is narrowed in a stepped manner, and the other end in contact with the lower part of the large diameter portion of the stationary stopper 12. Note that the pressing force of the disc spring 14 is set to be stronger than the return force of the spring IO against the armature 9. Further, a contact surface having a conical side surface shape with an apex in the axial upstream direction is formed at the lower end portion of the fixed stopper 12 on the small diameter side so as to come into contact with the spherical body of the valve body 1). This fixed side stopper 12 is connected to the device spring 14.
The inside of the body 3 can be swung against the pressing force of the body 3.
It forms a gap with the internal wall surface of.

A sheet 35 is placed in the space formed by the lower surface of the central portion 34 of the body 3 and the inner side surface of the tip.
It is fixed by bending the lower end. A conical recess that tapers toward the downstream direction of the jet is formed in the upper part of the sheet 35, and an injection hole 30 that communicates the apex of the conical shape with the outside of the sheet 35 is formed.

The valve body 1), which is integrally connected to the armature 9 and constitutes a movable part, penetrates through the spacer 24, the guide 33 inside the body 3, and the fixed stopper 12 through gap spaces.

The upper hemisphere of the spherical body at the end of the valve body 1) comes into contact with the contact surface of the lower end of the fixed stopper 12 when the coil 5 is energized, thereby regulating the lift amount of the valve body 1). The lower hemispherical portion of the movable stopper 13, which is normally in contact with the conical surface of the concave portion of the seat 35 due to the pressing force of the spring 10, is connected to the seat 35 when the coil 5 is energized, so that the injection hole 30 This is a valve part 1) 0 that opens the valve and adjusts the amount of fuel.

Further, a gap is formed between the armature 9 and the internal intermediate portion 23 of the housing 2, and the seat 35 is provided with the valve portion 1)0.
A fuel reservoir groove 350 is formed between the two.

With the above configuration, the electromagnetic fuel injection valve 1 operates as follows.

Due to the electromagnetic attraction force generated between the stator 8 and the armature 9, the valve body 1) is integrated with the armature 9.
moves in the direction of the stator 8, the movable stopper 1
3 comes into contact with the stationary stopper 12, thereby regulating the lift l of the valve body 1). At this time, under normal conditions, there is a gap between the outer peripheral surface of the armature 9 and the internal intermediate portion 23, a gap space formed by the valve body 1) with the spacer 24, the guide 33, and the fixed stopper 12, and the fuel reservoir groove 3.
The fuel accumulated in the valve part 50 is injected to the outside through the injection hole 30, which is opened when the valve part 1)0 separates from the seat 35.

By the way, as mentioned above, the lower end abutting surface of the fixed side stopper 12 described in (■) has a conical side surface shape, and the abutting surface of the movable side stopper 13 has a spherical shape, so both stoppers 12
．． The abutment by 13 will be made by the circumference.

Furthermore, even if the two strokes 47 and 12.13 start contacting each other in a state that is not completely stable due to errors due to processing precision as described above, the collision force of the movable stopper 13 causes the fixed stopper 12 to contact the movable stopper 13. Although it is not in sliding contact, it instantaneously moves slightly using the gap between the inner wall surface of the body 3 and the contact portion with the housing 2 as a fulcrum, and is again pressed against the inner wall surface of the body 3 by the disc spring 14. Therefore, the valve opening operation time is constant.

Furthermore, since the contact between the stoppers 12 and 13 is achieved by contact between a spherical surface and a conical surface, a complete contact state can be achieved very easily compared to the conventional contact between two surfaces. Therefore, the mtM adjustment mechanism using the disc spring 14 when the contact is incomplete is also much simpler than before.

Further, since the line of contact is circumferential, the adhesion force caused by the viscous force of the fuel is always constant, and the valve closing operation time does not vary, so stable fuel supply is possible.

Further, in this example, the movable stopper 13 is provided below the center of gravity of the valve body 1). As mentioned above, valve body 1
) is integrally connected with the armature 9 at its upper part, and is pressed together with the armature 9 against the seat 35 by a spring 10 when the valve is closed. Furthermore, while the valve is open, the armature 9 is attracted by the stator 8 and is lifted together. That is, the valve body 1) is operated by a force applied from the armature 9 to the upper part of the valve body 1). Therefore, it can be said that the position of the stopper that restricts the lift of the valve body 1) should be placed as far away from the armature 9 as possible, that is, if it is placed as low as possible in the figure, finer adjustment can be made with a small amount of force. From the above points as well, this embodiment is excellent.

Next, the main part of the second embodiment of the present invention will be explained using FIG. 2.

The body 3 serving as a fixed portion protrudes to the outside of the housing 2 similarly to the first embodiment. A conical recess and an injection hole 30 similar to those formed in the seat 35 in the first embodiment are formed at the lower end of the body 3.

This fixed side stopper 120 has a shape in which the small diameter part of the fixed side stopper 12 according to the first embodiment is elongated in the axial direction, and the small diameter lower end has a conical side surface shape with an apex in the upstream direction of the axis. A contact surface is formed. A lower portion of the large diameter portion of the stationary stopper 120 is coupled to the upper surface of the upper end opening of the body 3 via the disc spring 14 . This stationary stopper 120 is pressed against the housing 2 by the device spring 14, and has a fuel hole 121 in its large diameter portion for passing fuel downstream.

Further, the fixed stopper 120 forms a gap with the inner wall of the body 3.

A spherical body similar to that of the first embodiment is integrally formed at the end of the valve body 1) integrally connected to the armature 9, the upper hemisphere of which is the movable stopper 13, and the lower hemisphere of which is separated from the body 3. Valve part 1) which adjusts the amount of fuel and opens the injection hole 30 by
It is 0.

The electromagnetic fuel injection valve constructed according to the second embodiment operates in the same manner as the first embodiment. However, the fixed side stopper 120
When the disc spring 1 moves slightly using the abutment part with the housing 2 as a fulcrum, the distance between this abutment surface and the abutment parts of the movable stopper 13 and the fixed stopper 12 is longer than that in the first embodiment.
Assuming that the pressing force of 4 is the same, the movement of this fixed-side stopper 120 will be lighter than the movement of the fixed-side stopper 120 of the first embodiment.

FIG. 3 shows only the main parts of the third embodiment, and shows the valve body 1.
), the shape of the end of the movable stopper 13 and the valve part 1)0
The structure is slightly different from the above. This embodiment also achieves the same operation as the first and second embodiments.

In the above three embodiments, the movable stopper is formed with a spherical surface, but the fixed stopper may be formed with a spherical surface.

Furthermore, the position of the movable stopper need not be set closer to the injection hole than the center of gravity of the valve body.

Further, the spring member is not limited to a disc spring.

Further, the fixed part is not limited to the body, and for example, the guide in the first embodiment may be used as the fixed part and a spring member may be attached thereto.

[Effects of the Invention] As described hereinafter, the electromagnetic fuel injection valve according to the present invention includes: a movable part including a valve part for metering fuel and a movable stopper; a fixed part fixed to a housing; a movable-side stopper provided on the movable portion; a fixed-side stopper provided on the fixed portion that regulates the lift ffi of the movable portion through contact with the movable-side stopper; the fixed-side stopper and the fixed portion; a spring member interposed between the fixed side stopper and the movable side stopper, a spherical surface is formed in the abutting portion of either the fixed side stopper or the movable side stopper, and the fixed side stopper is configured to be in contact with the movable side stopper. By adopting a structure characterized by being able to swing freely when in contact, the following effects can be obtained.

When the movable part is lifted, the movable side stopper comes into contact with the fixed side stopper, but the fixed side stopper provided on the fixed member via the spring member is moved by the movable side stopper due to the spherical surface. sliding contact. At this time, the contact is
Since the circumference is used as the line of contact, contact is easy and can be stabilized instantly. In addition, there is almost no error in the time required for complete contact each time, and even if the positions of the two stoppers shift, there is no change in the facing area as in contact between surfaces, and the same shape is always maintained. It is possible to maintain contact with the contact line.

Therefore, the machining accuracy and assembly accuracy when installing the stopper may be poor, or the pressing force of the spring that presses the armature and the suction force that attracts the armature may be inconsistent with the axial direction of the movable part. Even if you don't have it,
It is possible to maintain a constant valve opening and closing operation time due to fluctuations in the buffering force and adhesion force caused by the viscous force of the fuel, so problems such as the fuel injection amount fluctuating over time can be avoided. This eliminates the problem, and the exhaust gas performance and fuel efficiency remain unchanged.

Furthermore, by using the spherical surface as a direct contact surface, the mechanism is much simpler than the conventional structure in which the spherical surface is used for fine adjustment of flat contact, and is easy to manufacture and inexpensive. It is possible to provide an electromagnetic fuel injection valve.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an electromagnetic fuel injection valve according to a first embodiment of the present invention, FIG. 2 is a sectional view of essential parts of an electromagnetic fuel injection valve according to a second embodiment, and FIG. 3 is a sectional view of a third embodiment of an electromagnetic fuel injection valve. FIG. 4 is a sectional view of a conventional electromagnetic fuel injection valve. 1... Electromagnetic fuel injection valve, 2... Housing, 3...
...Body as a fixed part, 5...Coil, 9°...
・Armature, 1)... Valve body as a moving part, 12
...Fixed side stopper, 13...Movable side stopper, 1
4... Disc spring as a spring member, 1) 0... Valve part. Compiled by Takashi Okabe, Patent Attorney Agent 1 Figure 2 Figure 1) 0 hits Figure 3 Figure 4

Claims (3)

[Claims] (1) A coil disposed inside the cylindrical housing, an armature operated by the electromagnetic force of this coil, and a valve part and a movable stopper that are integrally connected to this armature and measure fuel. a movable part having a movable part, a fixed part fixed in the housing, a movable-side stopper provided on the movable part, and a movable-side stopper provided on the fixed part that lifts the movable part by contacting with the movable-side stopper. A fixed side stopper for regulating the amount, and a spring member interposed between the fixed side stopper and the fixed part, and a spherical surface is provided on the abutting part of either the fixed side stopper or the movable side stopper. An electromagnetic fuel injection valve characterized in that the fixed stopper is swingable when in contact with the movable stopper. (2) the spherical surface is formed on the movable stopper, and a conical surface that comes into contact with the spherical surface is formed on the fixed stopper;
The electromagnetic fuel injection valve according to claim 1, which regulates the amount of lift of the movable part. (3) The electromagnetic fuel injection valve according to claim 1 or 2, wherein the movable side stopper is formed at a position closer to the injection hole than the center of gravity of the movable part.