JPS62255569A - Fuel injection valve - Google Patents

Abstract

PURPOSE:To permit the regulation of a moving amount of a needle valve while fuel is injected by providing a regulating unit at the opening end of a valve case for regulating a distance between stoppers on a moving side and a stopper on a fixed side. CONSTITUTION:First and second stoppers serving as stoppers on a moving side are made abutment against a spacer 12 serving as a stopper on a fixed side for keeping an operating stroke h of a needle valve 14 constant. When an amount of fuel injection is to be regulated, a screw 18 serving as a regulating unit is move upwardly and downwardly while fuel is injected for thereby determining the position of a valve case 17 with respect to a body 13 so as to regulate the operating stroke h. At the time, the urging force of a regulating spring 87 permits the valve case to move together with the screw 18 and and the spring 67 permits the needle valve 14 to move together with the valve case 17. When a position of the valve case 17 corresponding to a prescribed injection amount is reached, the screw 18 is fixed to the opening lower edge 13b of the body 13 by spot welding.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection valve that meters and supplies fuel to an internal combustion engine.

[Conventional technology]

Among conventional fuel injection valves, the needle valve inserted into the valve case body moves axially outward, and the valve end leaves the opening edge of the valve case body to the outside to inject fuel to the outside. In this case, the amount of fuel injected into the gap between the outer periphery of the needle valve and the internal wall of the valve case is determined by the area of this gap and the opening area between the valve end and the opening edge due to the amount of movement of the needle valve. Here, the amount of movement of the needle valve is regulated by a movable stopper provided on the needle valve coming into contact with a portion of the valve case body. The amount of movement is adjusted by changing the length of the abutting portion of the valve case body and the opening edge. In reality, the fitting member constituting the intermediate portion of the valve case body is replaced every time the injection quantity is measured, and the length of the valve case body is determined by the thickness of the fitting member that achieves a predetermined injection quantity.

[Problem that the invention seeks to solve]

However, with this method, fuel injection must be stopped and the needle valve must be removed each time several members of different thicknesses are attached and detached, and such work is difficult to perform when considering the efficiency of the assembly process. However, the efficiency was extremely poor, and as this member was repeatedly attached and detached, the injection amount changed slightly, making it impossible to make correct adjustments.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection valve in which the amount of movement of a needle valve can be adjusted during fuel injection, thereby significantly improving work efficiency and metering volume.

[Means for solving problems]

Therefore, in the present invention, a valve case body disposed within a body, a needle valve whose distal valve end part is spaced outward from the opening edge of the valve case body and injects fuel, and a stopper on the movable side of the needle valve are provided. The fuel injection valve has a fixed side stopper that is in contact with the body and is provided on the body, and an adjustment section that is provided on the opening edge and adjusts the axial distance between the movable side stopper and the fixed side stopper.

[Effect]

Thereby, the distance between the movable stopper and the fixed stopper is adjusted by the adjustment section. This adjustment portion is provided at the edge of the opening, which means that the amount of movement of the needle valve can be easily adjusted without removing or attaching the needle valve.

〔Example〕

FIG. 1 shows a fuel injection valve according to an embodiment of the present invention, in which a tubular iron pipe 1 through which fuel is supplied is formed at its upper end, and a filter 2 and an adjustment pipe 3 are fixed to the fuel passage inside the pipe. has been done. A movable core 4 is provided at a position facing and away from the lower end of the iron vibrator 1, and this movable core 4 is urged downward by a spring 34 provided between it and the adjust pipe 3. This movable core 4 has first and second pipes 51 connected to the iron pipe 1.
and 52 and is slidable in the axial direction.

This pipe 51.5 is used to move this movable core 4.
A coil 7 wound around a bobbin 6 is arranged on the outside of the coil 2.
These are covered from the outside with a cylindrical cover 8. The upper part of the cover 8, the first pipe 51 and the iron pipe 1
An injection-molded resin connector 9 is formed on the outer periphery of the coil 7, and the coil 7 generates an electromagnetic force by an electric signal supplied from a connector pin 9a of the connector 9. Then, the second pipe 52 is tightened at the lower end of the cover 8.
A magnetic pipe 11 is formed on the inner wall of the substantially cylindrical housing 10 facing the lower end of the movable core 4 with an air gap of size l, and this magnetic pipe 11 is moved by the electromagnetic force. The movable core 4 is sucked downward.

At the lower part of the magnetic pipe 11 on the inner wall of the housing 10, there is provided a spacer 12 as a stationary stopper with a hole formed in the center, and a substantially cylindrical body 13 is provided at the lower part of the spacer 12, and the body 13 is connected to the housing. 10 through the first O-ring 13a for maintaining liquid tightness at the lower end of the housing 10, the magnetic pipe 11 spacer 12 and body 13 are integrated and fixed to the inner wall of the housing 10. be done.

A fuel passage hole 4a is formed in the movable core 4 in the axial direction, and a pressure piece 4b is fitted into the downward widening portion of the passage hole 4a, and this pressure piece 4b is in constant contact with the needle valve 14. There is. The needle valve 14 is provided with a movable stop within the magnetic pipe 11, consisting of a first and a second stop 15,16. Here, needle valve 1
4 is a hollow valve case body 1 fixed to the body 13 via a second O-ring 17a for maintaining liquid tightness below the movable stopper after the position within the body 13 is determined.
7 in the axial direction.

As shown in FIG. 2, which is an enlarged view of the movable stopper, a spring 67 is provided between the stepped portion on the outer periphery of the valve case body 17 and the lower surface of the second stopper 16. The second stopper 16 is pressed upward. This pressing force is larger than the downward urging force of the spring 34. The second stopper 16 is provided between the spacer 12 and the above! The outer periphery of the needle valve 14 is rotatable through an operating stroke h smaller than that of the first stopper 15. A convex spherical surface 16a is formed on the upper part of the needle valve 14, and the convex tapered surface 15a of the lower part of the first stopper 15 contacts the concave tapered surface 15a of the first stopper 15. are in contact with each other. The upper portion of the first stopper 15 is locked to the stepped portion 140 of the needle valve 14 by the pressing force of the spring 67.

Referring again to FIG. 1, a fuel hole 17b is provided in the side wall of the valve case body 17 to allow fuel to flow in from the inner circumference of the body 13, and this fuel is allowed to reach the gap between the inner circumference and the inner circumference of the valve case body 17. Therefore, a narrow inflow portion 14a is formed on the outer periphery of the needle valve 14. The needle valve 14 is formed with a metering part 14b connected to the downstream side of the inflow part 14a and having a slightly larger diameter than the inflow part 14a. A valve end portion 14c is formed. A downwardly tapered valve seat is formed at the opening edge 17c at the tip of the valve case body 17, and is seated from the outside by the valve end 14c.

After flowing through the iron vibrator 1, the fuel supplied to the fuel injection valve passes through the passage hole 4a of the movable core 4, and passes from the outer periphery of the needle valve 14 and the first and second stoppers 15, 16 to the hole of the spacer 12. , flows through the fuel hole 17b from between the valve case body 17 and the body 13, reaches the outer periphery of the metering portion 14b from the outer periphery of the inflow portion 14a, and flows through the opening edge 17c of the valve end portion 14c.
The inside of the valve case 17 is filled by the seating.

Now, when an electric signal is supplied from the connector pin 9a of this fuel injection valve and the coil 7 is excited, an attractive force is generated between the movable core 4 and the magnetic pipe 11 due to the electromagnetic force of the coil 7, and this attractive force is applied to the spring. 34 and the spring 67, the movable core 4 is attracted and moved by the magnetic pipe 11, and the pressing piece 4b pushes the rear end of the needle valve 14 to overcome the operating stroke h and the second stopper 16 is moved. It collides with the spacer 12. Even if this contact is not completely parallel due to processing errors of the needle valve 14, the second stopper 16 rotates around the needle valve 14 due to this collision force, and furthermore, the second stopper 16 rotates around the needle valve 14 due to the collision force. Spherical surface 16a and the first
While maintaining or correcting the parallel state achieved by the tapered surface 15a of the stopper 15, stable contact can be constantly repeated, and bouncing during valve closing and uneven wear of the stopper can be prevented. Also, the injection amount of this injection valve is
This is determined by the size of the diameter of the metering portion 14b and the area of the nozzle opening of the valve end 14C that corresponds to the operating stroke h of the needle valve 14. In this way, the movable stopper becomes the fixed stopper. By always making stable contact, the operating stroke h of the needle valve 14 is always constant.

Note that this h is adjusted by determining the axial fixing position of the valve case body 17 with respect to the body 13. An adjustment spring 87 is provided between the stepped portion of the valve case body 17 formed on the outside of the spring 67 and the lower end of the spacer 12. It is energizing. In addition, the opening lower end 1 of the body 13 projects downward from the opening of the housing 10.
A thread is formed on the inner wall of 3b, and a screw 18 serving as an adjustment portion having a tapered surface in a hollow portion is provided on this inner wall to widen the injection. When adjusting the injection amount, JM is applied to the coil 7 to determine the position of the valve case body 17 with respect to the body 13, and the screw 18 is moved up and down while injecting fuel. At this time, the valve case body 17 also moves along with the screw 18 due to the biasing force of the adjustment spring 87, and the needle valve 14 also moves along with the valve case body 17 due to the spring 67. When the specified injection amount is reached, tighten the screw 18 to the body 13.
It is fixed to the opening lower end 13b by spot welding. That is, the tension can be increased or decreased by moving the screw 18 up or down.

With this configuration, the operating stroke h of the needle valve 14 can be adjusted while checking the fuel injection amount, so this adjustment can be performed easily and with high precision.

In this embodiment, the screw 18 is fixed to the body 13 by spot welding, but an adhesive or the like may be used as the fixing means.

Moreover, the metering part 14a is not used for metering the fuel, and the fuel hole 1
The size of 7b may be reduced to provide a metering function, or metering may be performed simply by adjusting the operating stroke h of the needle valve 14 using the adjustment section 18.

Further, the spacer 12 and the body 13 may be configured as one member.

[Effects of the Invention] According to the present invention, it is possible to adjust the amount of movement of the needle valve that determines the amount of fuel to be injected using the adjustment section provided at the opening edge at the tip of the valve case body.

Therefore, the fuel injection amount can be adjusted without removing or attaching the needle valve, resulting in a fuel injection valve with greatly improved working efficiency and metering accuracy.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a fuel injection valve according to the present invention, and FIG. 2 is an enlarged view of the movable side stopper and its vicinity. 12... Spacer forming a fixed side stopper, 13...
Body, 14... Needle valve, 14c... Valve end,
15.16... First stopper and second stopper forming the movable side stopper, 17... Valve case body, 17c...
・Opening edge, 18...Screw forming the adjustment part. Representative Patent Attorney Takashi Okabe Figure 1 Figure 2

Claims (2)

[Claims] (1) Fuel flows into the gap between a hollow valve case body disposed in a substantially cylindrical body and a wall surface of the hollow part that is inserted through the hollow part of the valve case body so as to be movable in the axial direction. Also, a needle valve having a valve end provided at the tip thereof and injecting the fuel by leaving the opening edge of the tip of the valve case body to the outside, and a needle valve provided on the needle valve to restrict movement of the needle valve. a movable-side stopper that is provided on the body and that the movable-side stopper abuts; and a fixed-side stopper that is provided on the opening edge of the valve case body and that has an axial distance between the movable-side stopper and the fixed-side stopper. A fuel injection valve characterized in that it has an adjustment section for adjusting. (2) The fuel injection valve according to claim 1, wherein the adjustment portion is a hollow screw. (3) The fuel injection valve according to claim 1 or 2, wherein the movable stopper is rotatably provided around the outer periphery of the needle valve.