JPS6111449A - Electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE:To restrict a degree of freedom of movement of a movable iron core, and improve fuel metering accuracy and stability of fuel atomization and injection amount every injection stage, by supporting the movable iron core to a support member and driving the movable iron core about a fulcrum member. CONSTITUTION:Fuel supplied to an inlet 11 is introduced through a strainer 12, pipe 13, passage 27 in a fixed iron core 4, hole 19 in a movable iron core 15, etc. to a valve chamber 14. When an electromagnetic coil 5 is excited to attract and lift the movable iron core 15 to a coil assembly 6 with rotation about a ball 32, a ball valve 16 is separated from a valve seat 22, and accordingly fuel in the valve chamber 14 is injected from an injection hole 23 to an engine. The amount of fuel to be injected may be controlled according to operational conditions of the engine by controlling a time for supplying current to the electromagnetic coil 5 according to the operational conditions of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electromagnetic fuel injection valve used, for example, in a fuel supply system for an internal combustion engine for an automobile.

(Prior Art) Electromagnetic fuel injection valves used in conventional fuel supply systems for automobile internal combustion engines include needle valve types and ball valve types.

The basic configuration and operation of the electromagnetic fuel injection valves described above are the same, and when the electromagnetic coil provided inside the housing is energized, the fixed iron core is energized, and the spring provided between it and the fixed iron core is energized. Against this, the movable core is attracted toward the fixed core. When the movable core is driven, the valve body, which is integrally provided with the movable core, is separated from the valve seat and opens the nozzle hole.

Further, the vicinity of the valve body is filled with fuel pumped by a fuel pump, and as the above-mentioned valve body is removed from the valve seat, fuel is injected from the nozzle hole.

(Problem that cannot be solved by the invention) With the above configuration, especially in the ball valve type, the shape of the movable iron core is a flat disk shape, and a reliable guiding mechanism for the flat movable iron core is not provided. As a result, the degree of freedom of movement of the flat movable iron core was large, and as shown in FIG. 2, the operation of the flat movable iron core was repeated in a state where the operating stroke was not stable each time. As a result, as shown in Figure 3, the measurement accuracy of the injection amount,
There was a problem that the stability deteriorated each time the spray was applied.

In addition, Nippondenso Technical Report, Reference number 26-118 states that the ball is placed between the flat movable iron core and the fixed iron core, but even in this electromagnetic fuel injection valve, the flat movable iron core has freedom of movement. The problem is large, and the above problems cannot be fully solved.

Therefore, an object of the present invention is to provide an electromagnetic fuel injection valve that solves the above problems.

(Means for Solving the Problems) In order to solve the above problems, the electromagnetic fuel injection valve of the present invention includes a fulcrum member in the valve chamber into which fuel is supplied and driven by the movable iron core. A holding member that holds the fulcrum member is provided, an end portion of the movable iron core is supported by the fulcrum member, and the movable iron core is driven using the fulcrum portion as a fulcrum.

(Example) A first embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, 1 is a housing, and a body 2 and a sleeve 3 are attached to an opening at one end of the housing 1. As shown in FIG. A coil assembly 6 consisting of a fixed iron core 4 and an electromagnetic coil 5 is inserted into the housing 1.
A ring 28 is provided between the coil assembly 6 and the body 2. Therefore, the coil assembly 6, ring 28, body 2, and sleeve 3 are arranged in this order along the axial direction, and are fixed to the housing 1 by constricting the opening edge of the housing 1.

The coil assembly 6 is provided concentrically with the housing 1, and houses the electromagnetic coil 5 in a space surrounded by the inner and outer walls of the fixed iron core 4. The electromagnetic coil 5 is supplied with a pulse voltage as shown in FIG. 3fa) from a control device (not shown) via a connector 8.

Note that the fixed core 4 has a flange-like projection 9 formed at its end.
A section 1 in which the flanged projection 9 is formed on the inner circumferential surface of the housing 1
0 and the ring 28.

A fuel inlet 11 is opened at the other end of the housing l, and this inlet 11 communicates with a valve 13 via a strainer 12. The valve 3 is connected to the central axis 2 of the housing 1 and the fixed iron core 4, and is tightened and engaged with the housing 1 after adjusting its position. The pipe 13 is communicated with a valve chamber 14 . That is, a double valve chamber 14 is formed between the coil assembly 6 and the ring 28, and within this valve chamber 14 is a flat disk-shaped movable iron core 15 made of permalloy or the like with good magnetic properties. A ball valve body 16 integrally connected to the movable core 15 is housed in a movable manner. The movable iron core 15 faces the tip end surface of the coil assembly 6 so as to be able to move toward and away from it.

Further, a holding member 31 is provided along the ring 28 in a part of the two bodies of the valve chamber 14, and a ball 3 serving as a fulcrum member is provided between the holding member 31 and the end of the movable iron core 15.
2 is disposed, and the movable iron core 15 is driven using this ball 32 as a so-called hinge fulcrum.

Incidentally, a spherical fitting hole is provided in both the holding member 31 and the end portion of the movable core 15 where the ball 32 is disposed. Also, the frame is always connected to the coil assembly 6 by the spring 17 passed between the pipe 13 and the movable iron core 15.
It is pressed and biased in a direction away from the body 2, that is, toward the body 2 side. Note that the pressing force of the spring 17 is the same as that of the pipe 1.
Adjustment can be made by changing the mounting position of item 3.

In addition, the movable iron core 15 is moved by the spring 17 to the body 2.
In the state in which the movable core 15 is pressed to the side, the end portion of the movable core 15 contacts and is supported by the ball 32 on the holding member 31, so that it is oriented obliquely in FIG. In this state, the end of the movable core 15 in contact with the ball 32 and the portion facing the coil assembly 6 are provided with the movable core 15.
In order to prevent the ball 32 from falling off between the end of the movable core 15 and the holding member 31 during the drive of the movable core 15, when the movable core 15 is driven, the movable core is A predetermined gap is provided so that the end of the coil assembly 6 which is in contact with the ball 32 of the coil assembly 6 does not come into contact with the coil assembly 6 and impede the drive. Note that the ball 32 may be fixed to either the end of the movable core 15 or the holding member 31 in order to prevent the ball 32 from falling off.

When an excitation current is supplied to the electromagnetic coil 5, the movable iron core 15 is attracted to the coil assembly 6 using the ball 32 as a fulcrum against the spring force of the spring 17 due to the electromagnetic attraction force, and when no excitation current is supplied, Spring 17
The movable iron core 15, that is, the ball valve body 16 is pressed toward the body 2 by the spring force. When the movable iron core 15 is attracted to the coil assembly 6, the pipe 13 and the valve chamber 14
A fuel passage 27 and a hole I9 are formed in the fixed core 4 and the movable core 15, respectively. The body 2 is formed with a conical valve seat 22 on which the ball valve element 16 approaches and separates, and this valve seat 22
A nozzle hole 23, which is an injection passage, is provided in the center of the nozzle. Due to the spring force of the spring 17, the movable iron core 1
5 is pressed against the body 2 side, the ball valve body 1
6 is seated on the valve seat 22 to close the nozzle hole 23, and an excitation current is supplied to the electromagnetic coil 5, so that the movable iron core 1
5 is suction driven, the ball valve body 16 separates from the valve seat 22 and opens the nozzle hole 23.

To explain the operation of the fuel injection valve configured in this way, the fuel sent by the fuel pump (not shown) is preliminarily adjusted to 2°C with respect to atmospheric pressure by the pressure regulating valve (not shown).
The pressure is regulated to a low pressure of ~3kg/vhs2 and the inlet port 11
be guided by. The fuel supplied to the inlet 11 is guided to the valve chamber 14 via the strainer 12, the vibrator 13, the passage 27 of the fixed core 4, the hole 19 of the movable core 15, and so on.

That is, the valve chamber 14 is always filled with fuel. The electromagnetic coil 5 is excited and the movable iron core 15 is connected to the coil assembly 6.
When the ball valve body 16 is sucked and lifted using the ball 32 as a fulcrum, the ball valve body 16 separates from the valve seat 22, so that the fuel in the valve chamber 14 is injected from the nozzle hole 23 to the engine (not shown).

Therefore, by controlling the time during which the electromagnetic coil 5 is energized according to the operating conditions of the engine, the amount of fuel injection can be adjusted to the amount corresponding to the operating conditions of the engine.

In this embodiment, the movable iron core 15 is connected to the ball 3.
2 as a fulcrum, the degree of freedom of movement of the movable core 15 is restricted, and the movable core 15 is driven in a constant and stable operating stroke, and as a result, the ball valve body 16
Since the position of the valve 22 relative to the valve seat 22 is stable, the measurement accuracy of the injection amount, the spray in each fuel injection, and the injection amount are stabilized.

Next, a second embodiment of the present invention will be described using FIG. 4.

In this embodiment, an acute-angled conical protrusion 33 is formed on a portion of the holding member 31 facing the movable iron core 15, and this protrusion 33 is used as a fulcrum member. A recess into which the protrusion 33 fits loosely is provided in a portion of the movable core 15 that abuts and is supported by the protrusion 33 . A predetermined gap is provided between the movable iron core 15 and the coil assembly 6, which is determined in the same manner as in the first embodiment. Note that the other configurations are the same as in the first embodiment.

The operation of the fuel injection valve having the above configuration is similar to that of the first embodiment, and in this embodiment, when the electromagnetic coil 5 is excited, the movable iron core 15 uses the protrusion 33 as a fulcrum to resist the spring force of the spring 17. The ball valve body 16 is moved away from the valve seat 22 and the fuel in the valve chamber 14 is injected from the injection hole 23 into the engine.

Therefore, by controlling the time during which the electromagnetic coil 5 is energized according to the operating conditions of the engine, the amount of fuel injection can be adjusted to the amount corresponding to the operating conditions of the engine.

In this embodiment, the movable iron core 15 is connected to the protrusion 33.
Since it is driven with the fulcrum at Since the position of the valve 22 relative to the valve seat 22 is stable, the measurement accuracy of the injection amount, the spray in each fuel injection, and the injection amount are stabilized.

Next, a third embodiment of the present invention will be described using FIG. 5.

In this embodiment, a holding member 3 is attached to the end of the movable iron core 15.
A ball 32a made of a non-magnetic material is provided in a recess between the movable iron core 1 and the coil assembly 6 and is in contact with both. Further, the holding member 31 is provided with a spherical recess that fits into the spherical surface of the ball 32a. and,
This ball 32a acts as a fulcrum member, and the electromagnetic coil 5
is excited, the fixed core 15 is attracted against the spring force of the spring 17, but at this time, the ball 32a
rotates between 6 and 31 while contacting both the coil assembly 6 and the holding member 31. In other words, the ball 32a functions like a fulcrum for a hinge. In addition, ball 3
To facilitate rotation of ball 32a, four spherical portions may be provided on the coil assembly 6 side to fit with the spherical surface of ball 32a.

Further, the other configurations are the same as in each of the above-described embodiments.

As described above, the movable iron core 15 is connected to the coil assembly 6.
When the ball valve body 16 is sucked and lifted using the ball 32a as a fulcrum, the ball valve body 16 separates from the valve seat 22, so that the fuel in the valve chamber 14 is injected from the injection hole 23 to the engine. Therefore,
By controlling the time during which the electromagnetic coil 5 is energized according to the operating conditions of the engine, the amount of fuel injection can be adjusted to the amount corresponding to the operating conditions of the engine.

In this embodiment, the movable iron core 15 is connected to the ball 3.
Since the movable iron core 15 is driven using the fulcrum 2a as a fulcrum, the degree of freedom of movement of the movable iron core 15 is restricted, and the movement is performed in a constant and stable operation stroke, resulting in a stable difference in the distance between the ball valve body 16 and the valve seat 22. Therefore, the measurement accuracy of the injection amount, lIJ at each fuel injection! This will stabilize the amount of fog and injection.

(Effects of the Invention) As described above, according to the present invention, the movable core is supported by the support member and the movable core is driven using the fulcrum member as a fulcrum, so the degree of freedom of movement of the movable core is regulated. Stable operation is possible, and injection amount measurement accuracy and stability of spray and injection amount each time are greatly improved. Therefore, it is possible to reduce fluctuations in rotational speed when the engine is idling and to reduce variations in air-fuel ratio between cylinders, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the first embodiment of the present invention, FIG. 2 is a sectional view showing the movement of the flat movable iron core of a conventional ball valve type electromagnetic fuel injection valve, and FIG. 3 +Il+ is an electromagnetic The energization pulse applied to the type fuel injection valve, Fig. 3 (bl is shown in Fig. 3 (
A diagram showing the lift state of the flat movable iron core when the energization pulse shown in a) is applied to the conventional electromagnetic fuel injection valve shown in FIG. 2, and FIG. 4 shows a second embodiment of the present invention. 5 is a sectional view showing a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Housing, 2... Body, 4... Fixed core, 5... Electromagnetic coil, 6... Coil assembly, 14
... Valve chamber, 15... Movable iron core, 16... Ball valve body, 17... Spring, 22... Valve seat, 23...
- Nozzle hole, 31... Holding member, 32.32a... Ball, 33... Conical projection.

Claims (1)

[Claims] A housing, a coil assembly including an electromagnetic coil and a fixed iron core fixed inside the housing, a valve chamber formed in the housing into which fuel is supplied and injected, and fuel injected from this chamber. a body in which an injection passage and a valve seat are formed; a valve body for opening and closing the valve seat; a spring for pressing the valve body against the valve seat; An electromagnetic fuel injection valve comprising a movable core that is attracted and driven by a three-dimensional fixed core in an excited state to separate the valve body from the valve seat, comprising: a fulcrum member in the valve chamber; a holding member that holds the fulcrum member; An electromagnetic fuel injection valve characterized in that an end portion of the movable iron core is supported by the fulcrum member, and the movable iron core is driven using the fulcrum member as a fulcrum.