JP2003254189A - Solenoid fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid fuel injection valve capable of performing the opening and closing motions sufficiently. <P>SOLUTION: The solenoid fuel injection valve includes a needle member N which is installed in a vessel H to be fed with the fuel and is moved in the +Z direction by the attracting forces FL and FS generated by an electromagnetic means, and thereby the size of a fuel passage PS consisting of a gap bounded by the inner surface IS of the vessel H and the outer surface of the needle member N is changed, wherein the electromagnetic means is furnished with a first magnetic circuit M1 and a second magnetic circuit M2 whose attracting forces FL and FS are controllable independently of each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electromagnetic fuel injection valve.

[0002]

2. Description of the Related Art A conventional electromagnetic fuel injection valve is described in, for example, Japanese Patent Application Laid-Open No. 2004-242242. The electromagnetic fuel injection valve described in the publication is configured such that the needle member provided in the container into which the fuel is introduced is moved in the longitudinal direction of the needle member by the suction force of the electromagnetic means, so that the inner surface of the container and the needle member are The size of the fuel passage defined by the gap between the outer surface and the outer surface is changed. After passing through the fuel passage, the fuel is emitted from the injection hole.

[Patent Document 1] JP-A-8-210217

[0003]

However, the conventional electromagnetic fuel injection valve has a problem that the suction force of the electromagnetic means is not appropriate and the opening / closing operation cannot be performed sufficiently. The present invention is
The present invention has been made in view of such a problem, and an object thereof is to provide an electromagnetic fuel injection valve capable of performing a sufficient opening / closing operation.

[0004]

In order to solve the above-mentioned problems, an electromagnetic fuel injection valve according to the present invention has a needle member provided in a container into which fuel is introduced by a suction force of the electromagnetic means. In the electromagnetic fuel injection valve in which the size of the fuel passage defined by the gap between the inner surface of the container and the outer surface of the needle member changes by moving in the longitudinal direction of the It is characterized by comprising controllable first and second magnetic circuits.

According to the electromagnetic fuel injection valve of the present invention, since the first and second magnetic circuits in which the suction force can be controlled independently of each other are used, the suction force can be set appropriately and a sufficient opening / closing operation can be performed. You can In particular, if the first magnetic circuit and the second magnetic circuit simultaneously generate an attractive force in a predetermined period, the attractive force can be increased and a sufficient opening / closing operation can be performed.

Further, by arranging the first and second magnetic circuits along the longitudinal direction of the needle member, the suction force is increased without increasing the size in the direction (radial direction) orthogonal to the longitudinal direction. Can be made.

Each of the first and second magnetic circuits has a pair of magnetic bodies that face each other with a gap therebetween and attract each other. At least one of the pair of magnetic bodies constitutes an electromagnet, and each of the pair of magnetic bodies has a needle. It is preferable that the member is arranged between the container and the needle member so that the member moves along the longitudinal direction by the attraction force of the magnetic body pair, and the magnetic circuit can be arranged compactly.

Further, if the first stroke length of the needle member formed by the first magnetic circuit is shorter than the second stroke length of the needle member formed by the second magnetic circuit, in other words, if the stroke length is different, the fuel is The size of the passage can be changed according to the stroke length, and precise fuel injection control can be performed.

In such a case, it is preferable that the size of the air gap of the first magnetic circuit when the attraction force is not generated is smaller than the size of the air gap of the second magnetic circuit when the attraction force is not generated. The smaller the gap, the stronger the suction force. At the moment when the size of the fuel passage is expanded from zero, a suction force relatively larger than the suction force thereafter is required. At the moment when the size of the fuel passage is expanded from zero, it is preferable to generate the attractive force at least in the first magnetic circuit having the shorter needle member stroke length.

Therefore, if the suction force on the first magnetic circuit side is increased by reducing the size of the air gap, the size of the fuel passage can be smoothly expanded.
Once the fuel passage is formed, the needle member can be moved with a relatively small force, so that the second stroke length that is longer than the first stroke length can be set, and the precise Fuel injection control becomes possible.

Further, in the electronic fuel injection valve of the present invention, when the needle member moves in the direction of the suction force for the first stroke length or more, the first and first biases the needle member in the direction against the suction force. The second elastic means may be provided so that the first elastic means applies a force to the needle member in the same direction as the suction force when the needle member moves in the suction force direction by less than the first stroke length. Preferably, when the needle member returns (when the needle member moves in the direction opposite to the suction force by the urging force of the elastic means), the needle member can be moved by the resultant force of the first and second elastic means, and Since the first elastic means does not resist the suction force when the suction force is applied, the needle member can be moved at high speed.

If the moving speed of the needle member when returning is too fast, the needle member bounces when it comes into contact with the inner surface of the container, and so-called secondary injection occurs. Such secondary injection is not preferable from the viewpoint of opening / closing controllability and fuel consumption.

In the electronic fuel injection valve of the present invention, when the needle member moves in the direction of the suction force, elastic means for urging the needle member in the direction against the suction force and the urging force of the needle member by the elastic means. When the needle member moves in the direction opposite to the suction force, the needle member is provided so as to collide with a specific member at a predetermined position that is larger than the closed position of the needle member and smaller than the first stroke length. And a stopper member. Accordingly, when the needle member returns, the stopper member collides with a specific member, so that the speed thereof decreases before the contact with the inner surface of the container, and the secondary injection decreases.

One of the magnetic body pairs of the first magnetic circuit is fixed to the container, and the other is movable relative to the needle member so that the suction force can be indirectly transmitted to the needle member. Is preferred. Although the needle member moves with respect to the container, the other of the pair of magnetic bodies indirectly transmits the suction force, so that unnecessary resonance at the time of returning the needle member can be suppressed.

[0015]

DETAILED DESCRIPTION OF THE INVENTION An electromagnetic fuel injection valve according to an embodiment will be described below. The same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1 is an explanatory view showing the mechanical connection relationship of the internal elements of the electromagnetic fuel injection valve. The electromagnetic fuel injection valve, the suction force of the needle member N disposed in the container H in which the fuel is introduced by electromagnetic means F _L, by moving in the longitudinal direction of the needle member N (+ Z direction) by the F _S , An electromagnetic fuel injection valve in which the size of the fuel passage PS defined by the gap between the inner surface IS of the container H and the outer surface of the needle member N changes, and this electromagnetic means is a suction force _FL ,
F _S is independent controllable first magnetic circuit M1 and the second
Magnetic circuit M2.

In this electromagnetic fuel injection valve, the state in which the needle member N closes the fuel passage passage PS is the "closed" state, and the state in which the fuel passage passage PS is formed is the "open valve".
It is in a state. The fuel introduced into the container H is injected from the fuel injection hole depending on the size of the fuel passage PS. The injection hole may be formed of the fuel passage PS itself, but may be provided on the rear side of the fuel passage PS.

According to the present electromagnetic fuel injection valve, the suction force F _L, because F _S is using the first and second magnetic circuits M1, M2 mutually independently controllable suction force (F _L and F _S function) can be set appropriately, and sufficient opening / closing operation can be performed. In particular, if the first magnetic circuit M1 and the second magnetic circuit M2 simultaneously generate a suction force for a predetermined period (T1, T2: see FIG. 8), the suction force can be increased and a sufficient opening / closing operation can be performed. Can work.

Each of the first and second magnetic circuits M1 and M2 has a pair of magnetic bodies (M1a, M1b) and (M2a, M2b) which face each other via the air gaps A1 and A2 and attract each other. One of the magnetic body pairs M1a and M1b (referred to as M1a) constitutes an electromagnet. In addition, the magnetic body pair M2a,
One of the M2b (referred to as M2a) also constitutes an electromagnet. The magnetic bodies forming the magnetic body pair M1a, M1b (M2a, M2b) may both form an electromagnet.

Although the electromagnet is a magnetic body to which a coil is added, the same reference numerals as those of the magnetic bodies M1a and M2a are used for the respective electromagnets for convenience of explanation.

The magnetic substance is a metal made of iron, cobalt, nickel or the like and is a substance whose magnetic pole is generated in a magnetic field. An electromagnet can be formed by winding a coil around such a substance. When a current is supplied to the coil, the magnetic flux generated by the coil current and the magnetic flux generated by the magnetic poles of the magnetic material around which the coil is wound pass through the gaps A1, A2, whereby a strong magnetic field is formed in the gaps A1, A2. A
Attraction force F _L in each of the magnetic circuits M1, M2 containing 2, F _S is produced.

In this example, the attraction force F _L of the magnetic circuit M1 when the valve is closed is also greater than the attraction force F _S of the magnetic circuit M2 (F _L > F _S ). Attraction force of the magnetic circuit M1 F _L void A1
Is inversely proportional to the size (air gap) G1 of the magnetic circuit M2
Of the suction force F _S is inversely proportional to the size (air gap) G2 of the air gap A2. That is, the dimension G1 of the gap A1 when the valve is closed
Is smaller than the dimension G2 of the void A2 (G1 <G2),
Accordingly, the suction force F _L is larger than the suction force F _S.

The magnetic material pair M1a, M1b (M2a,
In each of M2b), the needle member N has a magnetic body pair M1.
a, M1b (M2a, M2b) suction force of F _L, the F _S, is disposed between the container H and needle member N to move along the longitudinal direction (+ Z direction), the magnetic circuit M1 , M2 are compactly arranged.

The electromagnets M1a and M2a are fixed to the container H, the magnetic body M1b is connected to the driving force transmission member FX via the first elastic means (spring) S1, and the magnetic body M2b is connected to the needle member N. It is fixed.

Suction by the first magnetic circuit M1 during valve closing operation
Causes the magnetic body M1b to move in the + Z direction,
The driving force transmission member FX connected to the body M1b is the first elastic hand.
It moves in the + Z direction by the spring force of the step S1. Driving force transmission
Since the reaching member FX is fixed to the needle member N,
The saddle member N moves in the + Z direction and the fuel passage PS
Is formed and the valve is opened. The container H and the needle part
Connected to the material N by the second elastic means (spring) S2
And the attraction force F by the first magnetic circuit M1 _LIs the
2 The spring force of the elastic means S2 is resisted. Second elastic means S
2 is provided as needed.

The magnetic force _M 1b moves in the direction of the electromagnet M1a fixed to the container H by the attraction force FL, and when it abuts against it, the needle member N by the first magnetic circuit M1.
The movement of is almost stopped. When the Z direction position of the needle member N at the time of valve closing is set as the reference position, the distance from the reference position to the stop position becomes the stroke length (first stroke length) of the needle member N by the first magnetic circuit M1. In this example, the first stroke length corresponds to the gap dimension G1.

When the magnetic body M2b moves in the + Z direction due to the attraction by the second magnetic circuit M2 during the valve closing operation,
The magnetic body M2b is + Z against the spring force of the elastic means S2.
Move in the direction. Since the magnetic body M2b is fixed to the needle member N, the needle member N moves in the + Z direction. If this suction force acts when the valve is closed, the fuel passage P
S is formed and the valve is opened.

When the needle member N is at the position of the first stroke length or more and the magnetic body M2b moves in the + Z direction by the further suction by the second magnetic circuit M2, in addition to the spring force by the second elastic means S2. The magnetic body M2b moves in the + Z direction against the spring force of the first elastic means S1,
The needle member N fixed to this moves in the + Z direction. When the magnetic body M2b contacts the electromagnet M2a, the movement of the needle member N by the second magnetic circuit M2 is stopped. When the Z direction position of the needle member N at the time of valve closing is set as the reference position, the distance from the reference position to the stop position becomes the stroke length (second stroke length) of the needle member N by the second magnetic circuit M2. In this example, the second stroke length corresponds to the gap dimension G2. It is also possible that the stroke length and the void size are different.

The first stroke length (= G1) of the needle member N by the first magnetic circuit M1 is shorter than the second stroke length (= G2) of the needle member N by the second magnetic circuit M2. As described above, since the stroke length is different in the present electromagnetic fuel injection valve, the size of the fuel passage PS can be changed according to the stroke length, and precise fuel injection control can be performed.

The dimension G1 of the air gap A1 of the first magnetic circuit M1 when the attraction force is not generated (when the valve is closed) is larger than the dimension G2 of the air gap A2 of the second magnetic circuit M2 when the attraction force is not generated (when the valve is closed). Is also small. As described above, the smaller the gap, the stronger the suction force. At the moment when the size of the fuel passage PS is increased from zero, the pressure difference between the inside and the outside of the fuel injection hole strengthens the valve closing force, so it is relatively larger than the suction force after the valve opening operation is started. Needs suction power.

As described above, at the moment when the size of the fuel passage PS is expanded from zero, the attractive force is generated at least in the first magnetic circuit M1 having the shorter needle member stroke length. By reducing the size G1 of the gap A1, by increasing the suction force F _L of the first magnetic circuit M1 side when the valve is closed, it is possible to enlarge the size of the fuel passage path PS smoothly. Once the fuel passage PS is formed, the needle member N can be moved with a relatively small force, so that the second stroke length longer than the first stroke length can be set, It becomes possible to perform precise fuel injection control.

Further, the electromagnetic fuel injection valve of the present invention is configured such that when the needle member N moves in the direction of the suction force for the first stroke length or more, it urges the needle member N in the direction against the suction force. Two elastic means S1 and S2 are provided, and the first elastic means S1 applies force to the needle member N in the same direction as the suction force when the needle member N moves in the suction force direction by less than the first stroke length. When the needle member N is returned (the needle member N is elastic means S1,
When the needle member N can be moved by the resultant force of the first and second elastic means S1 and S2 when moving in the direction opposite to the suction force by the urging force of S2), and when the suction force is applied. Since the first elastic means S1 does not resist the suction force, the needle member N can be moved at high speed.

Further, one (M1a) of the magnetic body pair of the first magnetic circuit M1 is fixed to the container H, and the other (M1b) is movable relative to the needle member N and indirectly attracts force. Can be transmitted to the needle member N. The other side (M1b) of the magnetic body pair indirectly attracts force F _L.
Is transmitted, it is possible to suppress unnecessary resonance when the needle member returns.

The electromagnetic fuel injection valve described above can be modified in various ways.

FIG. 2 is an explanatory view showing the mechanical connection relation of another electromagnetic fuel injection valve internal element. This electromagnetic fuel injection valve is also similar to the above-mentioned injection valve, in that the needle member N provided in the container H into which the fuel is introduced attracts the needle member N by the electromagnetic means.
Longitudinal direction of needle member N (+ Z direction) by _L and F _S
To the fuel passage path P defined by the gap between the inner surface IS of the container H and the outer surface of the needle member N.
This is an electromagnetic fuel injection valve in which the magnitude of S changes, and this electromagnetic means is provided with a first magnetic circuit M1 and a second magnetic circuit M2 whose suction forces F _L and F _S can be controlled independently of each other. Figure 1
The difference from the one shown in FIG. 5 is that the first elastic means S1 is not provided, and the magnetic body M1b can abut against the stopper member NS fixed to the needle member N at the time of suction, and the magnetic body M1b becomes the third elastic means (spring). ) It is connected to the container H via S3. Other configurations are the same.

The attraction force of the first magnetic circuit M1 is the magnetic body M1b.
The stopper member NS that abuts on the
Direction, the needle member moves in the + Z direction. When a further stroke is required, when the attraction force of the second magnetic circuit M2 is applied, the needle member N exceeds the first stroke length and the magnetic body M1b and the stopper member NS are separated from each other. Other actions are similar to the above.

FIG. 3 is an explanatory view showing a mechanical coupling relationship of still another internal element of the electromagnetic fuel injection valve. Similar to the electromagnetic fuel injection valve is also above the injector, longitudinal (+ Z suction force F _L, F _S by the needle member N the needle member N disposed in the container H in which the fuel is introduced by electromagnetic means Direction), the size of the fuel passage PS defined by the gap between the inner surface IS of the container H and the outer surface of the needle member N changes, which is an electromagnetic fuel injection valve. It has a first magnetic circuit M1 and a second magnetic circuit M2 whose attraction forces F _L and F _S can be controlled independently of each other.

The difference from that shown in FIG. 1 is that the first elastic means S1 is not provided, and the magnetic body M1b can contact the stopper member NS fixed to the needle member N at the time of suction, and the magnetic body M1b is It is a point that is sucked against the elastic means S2. The magnetic body M1b is slidable with respect to an appropriate member. Other configurations are the same. As described above, various structures and mechanical couplings of the elastic means can be considered.

FIG. 4 is an explanatory view showing a mechanical coupling relationship of still another internal element of the electromagnetic fuel injection valve. In addition to the electromagnetic fuel injection valve shown in FIG. 1, this electromagnetic fuel injection valve has a magnetic body M during suction.
1b can contact the stopper member NS fixed to the needle member N. The magnetic body M1b is the first
When the stroke length is shorter than the second elastic means S2,
When the stroke length is longer than the stroke length, the first and second elastic means S1, S2
Is sucked against.

If the moving speed of the needle member N at the time of returning is too fast, it bounces when the needle member N contacts the inner surface IS of the container H, and so-called secondary injection occurs. Such secondary injection is not preferable from the viewpoint of opening / closing controllability and fuel consumption.

In the present electronic fuel injection valve, when the needle member N moves in the direction of the suction force (+ Z direction), the elastic means S2 (S) that biases the needle member N in the direction against the suction force.
1) and when the needle member N moves in the direction (-Z direction) opposite to the suction force by the urging force of the elastic means S2 (S1), the needle member N is moved to a position larger than the reference position when the needle member N is closed. A stopper member NS provided on the needle member N is provided so as to collide with a specific member (the magnetic body M1b in this example) at a predetermined position less than one stroke length.

In this structure, the stopper member NS
Is a shock-absorbing S when the needle member N returns.
It collides with the magnetic body M1b attached to 1. When the needle member N collides with the magnetic body M1b at the time of returning in this way, the speed thereof decreases before the contact with the container inner surface IS, and the secondary injection decreases. The stopper member NS may be elastically supported.

Next, a specific structural example of the above-mentioned electromagnetic fuel injection valve will be described. Among the above-mentioned electromagnetic fuel injection valves, the one shown in FIG. 4 is the most preferable, so in the following,
What materialized this is demonstrated.

FIG. 5 is a vertical sectional view of the electromagnetic fuel injection valve.

In this electromagnetic fuel injection valve, fuel is supplied into the container H from the fuel supply port 1a located at the end of the fuel supply pipe 1. The container H includes a container body 100 and a nozzle 17 attached to the tip of the container body 100 in the longitudinal direction.
Composed of. A needle member (needle valve) N is arranged in the container body 100, and the needle valve N is the nozzle 1
7 extends to the inside. Container body 100 and needle valve N
The first and second magnetic circuits M1 and M2 are disposed between and.

The first magnetic circuit M1 is composed of a cylindrical magnetic body (first core) M1a and a first coil M1c embedded in the first core M1a.
M1c). Further, the first magnetic circuit M1 includes an annular magnetic body (armature) M1b. A relatively slidable needle valve N is located in the opening of the armature M1b, and the armature M1b includes a first elastic means (first
It is connected to a driving force transmission member (stopper member) FX via a spring S1 and is elastically coupled to the needle valve N.

The second magnetic circuit M2 includes a cylindrical magnetic body (second core) M2a and a second magnetic body M2a embedded in the magnetic body M2a.
A second electromagnet (M2a, M2) including a coil M2c.
2c). Further, the second magnetic circuit M2 includes an annular magnetic body (armature) M2b. Armature M2
A needle valve N is fixed in the opening of b, and the armature M2b is connected to the container H via a second elastic means (second spring) S2 and is elastically coupled to the container H. In this example, the fuel supply pipe 1 fixed to the container H
The inner sleeve 1b is used as a stopper, and the needle valve N
The second spring S2 is interposed between the second spring S2 and the base end of the.

In the container H, the coils M1c and M2c
Each has a connector 2 for supplying current
And each suction by supplying current to each
Force F _L, F_SOccurs independently.

The fuel introduced from the fuel supply port 1a is provided in the inner region of the second core M2a, the fuel passage provided in the armature M2b, the inner region of the first core M1a, the first magnetic body M1b and the like. It reaches the inside of the nozzle 17 through the fuel passage and moves to just before the fuel passage (fuel seal portion) PS. An injection hole 19 is provided at the tip of the nozzle 17, and fuel is ejected from the injection hole 19 when the valve is opened. The operation of this device has been described above, but will be described in detail below.

FIG. 6 is a longitudinal sectional view of the electromagnetic fuel injection valve in each state.

In the valve closed state shown in FIG. 6 (a), no current is supplied from the connector 2 and the needle valve N is moved toward the fuel seal portion PS by the second spring force (biasing force) F2 of the second spring. It is biased, and the outer surface of the needle valve N closes the fuel seal portion PS.

The valve opening state for small amount injection shown in FIG. 6 (b) is set.
To start the valve opening operation,
Two first and second coils M constituting the magnetic circuits M1 and M2
Supply current to 1c and M2c. This allows the first sp
Needle valve N via ring S1 and stopper member FX
The force in the + Z direction is applied to the valve closing force F due to the differential pressure. _D
And the needle valve N burns against the second spring force F2.
Moves away from the material seal part PS and opens the valve
Then, fuel injection is started.

When the needle valve N is located at a predetermined position less than the first stroke length after the start of fuel injection, the second coil M
The current supply to 2c is stopped, the first armature M1b contacts the first core M1a, and the movement of the needle valve N is substantially stopped. Then, when the current supply to the first coil M1c is stopped, the spring force F generated by the first and second springs is increased.
1, F2 moves the needle valve N in the -Z direction,
The needle valve N contacts the inner surface of the container forming the fuel seal portion PS, and the valve is closed.

Since this injection has a small amount of fuel injection at one time, the degree of dispersion of the fuel is high and a highly dispersed spray is performed.

Incidentally, the stopper member NS provided on the needle valve N is decelerated by once colliding with the first armature M1b at a position shorter than the first stroke length, and thereafter, the stopper member NS is formed on the inner surface of the container constituting the fuel seal portion PS. Since the collision occurs, the secondary injection is suppressed.

In order to open the large amount injection valve shown in FIG. 6C, first, the connector 2 is moved to the first position when the valve opening operation is started.
Also, current is supplied to the first and second coils M1c and M2c forming the second magnetic circuits M1 and M2. As a result, a force in the + Z direction is applied to the needle valve N via the first spring S1 and the stopper member FX, so that the needle valve N resists the valve closing force F _D and the second spring force F2 due to the differential pressure. It moves in a direction away from the fuel seal portion PS, the valve is opened, and fuel injection is started.

Even when the needle valve N reaches the first stroke length after the start of fuel injection, the current supply to the second coil M2c is continued and the first armature M1b abuts on the first core M1a. The second armature M2b is attracted against the first spring force F1 of S1 and the spring force F2 of the second spring S2, and the needle valve N moves further upward.

At this time, the current supply to the first coil M1c can be stopped. Second armature M2b is second
When it abuts on the coil M2c, the movement of the needle valve N stops at the position of the second stroke length. Then, when the current supply to the second coil M1c (first coil M1c as necessary) is stopped, the needle valve N moves in the −Z direction by the spring forces F1 and F2 of the first and second springs, The needle valve N contacts the inner surface of the container forming the fuel seal portion PS, and the valve is closed.

Since this injection has a large amount of fuel injected at one time, the degree of dispersion of the fuel is low and high penetration injection is performed.

Even in the valve closing operation in this case, the stopper member NS provided on the needle valve N is decelerated by once colliding with the first armature M1b at a position shorter than the first stroke length, and then the fuel is discharged. Since it collides with the seal part PS, the secondary injection is suppressed.

FIG. 7 is an explanatory view for explaining the secondary injection suppressing function. When the needle valve N is in the position moved from the closed position (reference position) by the second stroke length (state C), this corresponds to the dimension G2 of the gap A2, but during the closing operation, the needle valve N Is closer to the valve closing position than the first stroke length (dimension G1) with the passage of time, the stopper member NS collides with the first armature M1b, and the spring S provided on the first armature M1b.
The shock is buffered by 1 and is decelerated along with the first armature M1b to move to the valve closed position.

That is, in the needle valve N, the position change amount (speed) with respect to the time becomes small immediately before reaching the valve closing position, and the collision speed with the inner surface of the container forming the fuel seal portion PS becomes low. . Therefore, the bounce at the time of this collision is suppressed, and the secondary injection is suppressed.

FIG. 8 shows the coils M1c and M2c in the valve closed state, during the valve opening operation for small amount injection and during the valve opening operation for large amount injection.
Supply current (solenoid driving pulse) I1, I2, to a suction force F _L, F _S, the spring force F1, F2, valve closing force by the pressure difference F _D, the timing chart of the needle valve position.

In the valve opening operation of the small amount injection, first, the solenoid drive pulses I1 and I2 are simultaneously supplied, and then the drive pulse I2 is stopped after a period T1. After the fuel injection, the drive pulse I1 is also stopped. By doing so, the valve closing operation is performed.

In the valve opening operation of the large amount injection, first, the solenoid drive pulses I1 and I2 are simultaneously supplied, and then the drive pulse I1 is stopped and the drive pulse I1 is stopped after the period T2 to perform fuel injection. After that, the drive pulse I2 is also stopped to perform the valve closing operation.

As described above, by making the stroke length of the needle valve N variable, necessary spraying can be performed according to the load of the engine, and fuel consumption can be improved. When a small amount is injected, the spray is dispersed at a wide angle, which is suitable for combustion in the low load range. Further, when a large amount of fuel is injected, the straightness of the fuel injection is high, which is suitable for combustion in a high load range.

The fuel injection amount per unit time is proportional to the duty ratio of the drive pulse I1 or I2.
If a small amount of fuel is injected, the fuel injection rate can be relatively reduced without changing the duty ratio, and if the duty ratio is also reduced, a very small amount of fuel can be injected.

In the large amount injection, the fuel injection rate can be relatively changed without increasing the duty ratio, and if the duty ratio is also increased, a very large amount of fuel injection can be performed. In this way, by adopting the above configuration, the dynamic range of the fuel injection rate can be expanded.

Further, in order to open the valve with respect to high fuel pressure, a large suction force is required. However, in the above-mentioned configuration, one is that the dimension G1 of the gap A1 is relatively narrow. by, it is possible to increase the attraction force F _L, also, by using the force of attraction force F _L, F _S, it is possible to further increase the suction force. Therefore, high fuel pressure can be achieved.

Further, by using the two springs S1 and S2, the resultant force of the spring forces F1 and F2 acts on the needle valve N during the valve closing operation, so that the responsiveness during the valve closing operation is improved. Also, when the valve is opened, one spring force F2 is applied.
Since only this works, the contribution of the suction force to the valve opening operation can be increased, and the responsiveness during the valve opening operation improves.

Further, in the above-mentioned structure, since the first and second magnetic circuits M1 and M2 are arranged along the longitudinal direction of the needle valve N, the direction (radial direction) orthogonal to the longitudinal direction.
The suction force can be increased without increasing the size of the.

In the fuel supply to the engine, it is required to reduce the evaporated gas, and a returnless system is considered as a fuel supply system as a measure for this. According to the electromagnetic fuel injection valve described above, a returnless structure or a rail pressure built-in structure can be adopted by directly operating the needle valve N with a solenoid.

[0073]

According to the electromagnetic fuel injection valve of the present invention, a sufficient opening / closing operation can be performed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a mechanical coupling relationship between internal elements of an electromagnetic fuel injection valve.

FIG. 2 is an explanatory view showing a mechanical connection relationship of another internal element of an electromagnetic fuel injection valve.

FIG. 3 is an explanatory view showing a mechanical coupling relationship of still another internal element of an electromagnetic fuel injection valve.

FIG. 4 is an explanatory view showing a mechanical coupling relationship of still another internal element of the electromagnetic fuel injection valve.

FIG. 5 is a vertical sectional view of an electromagnetic fuel injection valve.

FIG. 6 is a vertical sectional view of the electromagnetic fuel injection valve in each state.

FIG. 7 is an explanatory diagram for explaining a secondary injection suppressing function.

[8] coil M1c, supply current (solenoid drive pulses) to M2c I1, I2, attraction force F _L, F _S, the spring force F1, F2, valve closing force F _D, the timing chart of the needle valve position by the pressure difference Is.

[Explanation of symbols]

1b ... Sleeve, 1a ... Fuel supply port, 1 ... Fuel supply pipe,
2 ... Connector, 17 ... Nozzle, 19 ... Injection hole, 100 ... Container body, A1, A2 ... Void, F1, F2 ... Spring force, F _D ... Valve opening force, _FL , F _S ... Suction force, FX ... Stopper Member, G1 ... void size, G2 ... void size, H ... container, I
1, I2 ... Solenoid drive pulse, IS ... Container inner surface, M
1, M2 ... Magnetic circuit, M1a ... Core (electromagnet: magnetic body), M1b ... Armature (magnetic body), M1c, M2c
... Coil, M2a ... Core (electromagnet: magnetic body), M2b ...
Armature (magnetic material), N ... Needle member (needle valve), NS ... Stopper member, PS ... Fuel seal part (fuel passage path), S1 ... Spring (first elastic means), S2
... Spring (second elastic means).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Natsuki Sugiyama             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F-term (reference) 3G066 AB02 BA02 BA09 BA11 BA59                       CC01 CC05U CC06U CC14                       CC48 CC56 CC68U CE22                       CE23 CE24 CE25 CE26 DA08

Claims (9)

[Claims] 1. A needle member provided in a container into which fuel is introduced is moved between the inner surface of the container and the outer surface of the needle member by moving the needle member in the longitudinal direction of the needle member by an attractive force of an electromagnetic means. In the electromagnetic fuel injection valve in which the size of the fuel passage defined by the gap is changed, the electromagnetic means includes first and second magnetic circuits whose suction forces can be controlled independently of each other. Type fuel injection valve. 2. Each of the first and second magnetic circuits has a magnetic body pair that opposes each other through a gap and attracts each other. At least one of the magnetic body pairs constitutes an electromagnet, and the magnetic body pair of Each of them is arranged between the container and the needle member such that the needle member moves along the longitudinal direction thereof by the attraction force of the magnetic body pair. Electromagnetic fuel injection valve. 3. The electromagnetic type according to claim 2, wherein the first stroke length of the needle member formed by the first magnetic circuit is shorter than the second stroke length of the needle member formed by the second magnetic circuit. Fuel injection valve. 4. The size of the air gap of the first magnetic circuit when the attraction force is not generated is smaller than the size of the air gap of the second magnetic circuit when the attraction force is not generated. Item 2. The electromagnetic fuel injection valve according to Item 2 or 3. 5. A first elastic means and a second elastic means for urging the needle member in a direction against the suction force when the needle member moves in the suction force direction by the first stroke length or more. The first elastic means is arranged so as to apply force to the needle member in the same direction as the suction force when the needle member moves in the direction of the suction force by less than the first stroke length. The electromagnetic fuel injection valve according to claim 3, wherein 6. An elastic means for urging the needle member in a direction against the suction force when the needle member moves in the direction of the suction force, and the needle member by the urging force of the elastic means. The needle member is provided so as to collide with a specific member at a predetermined position that is larger than the closed position of the needle member and smaller than the first stroke length when the needle member moves in the direction opposite to the suction force. The electromagnetic fuel injection valve according to claim 3, further comprising a stopper member. 7. One of the magnetic body pairs of the first magnetic circuit is fixed to the container, and the other is relatively movable with respect to the needle member to indirectly apply the suction force to the needle member. The electromagnetic fuel injection valve according to claim 2, wherein the electromagnetic fuel injection valve is configured to be capable of being transmitted to the electromagnetic fuel injection valve. 8. The electromagnetic fuel injection valve according to claim 1, wherein the first magnetic circuit and the second magnetic circuit simultaneously generate a suction force in a predetermined period. 9. The electromagnetic fuel injection valve according to claim 1, wherein the first and second magnetic circuits are arranged along a longitudinal direction of the needle member.