JPH1162710A - Fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct highly precise quantity regulation with novel constitution. SOLUTION: A fuel passage of which one end forms a gas fuel supplying part 6 and of which the other end forms a fuel injection hole 7 is formed inside a housing 1, and arranged are a cutting-out valve element 16, a cutting-out return spring 18, a quantity regulating valve core 23, a needle 24, and a quantity regulating return spring 29. The valve element 16 is moved to cut out gas fuel by driving of a cutting-out solenoid valve 11 at the time of engine stopping, and the needle 24 is moved to regulate a quantity of the gas fuel by driving of a quantity regulating solenoid valve 12 at the time of engine operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device and, more specifically, is suitably applied to, for example, a gas injector for injecting gaseous fuel.

[0002]

2. Description of the Related Art CNG (Compressed Nat)
Japanese Unexamined Patent Application Publication No. Hei 8
2. Description of the Related Art A fuel injection device disclosed in JP-A-61152 is known. This fuel injection device, like a conventional liquid fuel injection device, regulates the injection amount by one operating portion including one reciprocating valve body and one valve seat to which this valve body can abut. And opening and closing of a fuel passage to which gas fuel is supplied.

[0003]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-open No. Hei 8-6
In the fuel injection device described in JP-A-1152, in which the adjustment of the injection amount and the opening and closing of the fuel passage are performed by one operating unit,
When the contact portion between the valve body and the valve seat is made of metal, it is difficult to prevent leakage of gas fuel from the contact portion even if the contact portion between the valve body and the valve seat is machined with high precision. is there.

[0004] In particular, gas fuel has no lubricating action unlike liquid fuel, so that the metal seal portion of the valve body is greatly worn and damaged, and it is difficult to maintain precise injection amount adjustment over a long period of use. In addition, there is a problem that exhaust emission is deteriorated or engine startability is poor.

[0005] Further, even in a direct injection injector for directly injecting liquid-phase gasoline into a cylinder, the fuel is at a high pressure, so that there is a problem of fuel leakage. Therefore, an object of the present invention is to provide a fuel injection device capable of performing highly accurate metering with a novel configuration.

[0006]

According to a first aspect of the present invention, there is provided a fuel injection device arranged in a fuel passage for shutting off fuel when the engine is stopped, and for moving the shutoff valve. A solenoid coil for shutting off, a metering valve body arranged in the fuel passage for metering a fuel injection amount during engine operation, and a metering solenoid coil for moving the metering valve body And, it is characterized by having.

With this configuration, when the engine is stopped, the shutoff valve is seated to shut off the fuel. In addition, during operation of the engine, the metering valve moves to adjust the fuel injection amount.

As described above, the shut-off valve for shutting off the fuel when the engine is stopped and the metering valve for adjusting the injection amount are independently arranged. Therefore, even if the shutoff valve is deformed, the influence of the deformation hardly affects the metering performance.

Further, the shut-off valve element is urged toward the valve closing side by a shut-off return spring, and the metering valve element is independent of the shut-off return spring. When the engine is stopped, the shut-off valve body is seated by the urging force of the shut-off return spring, and the gas fuel is shut off. During operation of the engine, the metering valve body moves against the urging force of the metering return spring, and the gas fuel injection amount is metered.

As described above, the shut-off valve for shutting off the fuel when the engine is stopped and the metering valve for adjusting the injection amount are arranged independently of each other. In addition, the metering valve eliminates the need to shut off the fuel when the engine is stopped, so that the urging force of the metering return spring can be weakened, and wear and damage to the seal of the valve body can be reduced. Can be precisely controlled over a long period of time.

In this manner, the wear of the seal portion of the valve body,
Damage can be reduced and fuel leakage when the engine is stopped can be prevented. Further, as described in claim 3, it is preferable that the shut-off valve element is moved in the fuel flow direction so as to be in an open state.

With this configuration, the valve can be opened with less force than when the shutoff valve moves in the direction opposite to the fuel flow direction during engine operation. Further, as described in claim 4, a through-hole extending from the downstream side to the upstream side of the fuel is formed in the shut-off valve body, and a stopper that covers a downstream opening of the through-hole is provided with the stopper. It is preferable to keep the valve open by contacting the body.

With this configuration, the stopper abuts in the valve open state, so that when the stopper abuts, there is no fuel pressure applied to the stopper abutment area in the closing direction, and the area of the stopper abutment area minus the through hole area is reduced. Only the fuel pressure is applied in the opening direction, so that the coil energization amount can be reduced after the stopper abuts.

According to a fifth aspect of the present invention, the shut-off solenoid coil and the metering solenoid coil are used in common, and the current flowing through the common solenoid coil is such that the valve-opening holding current of the shut-off valve is It is preferable that the current be smaller than the valve-opening holding current of the metering valve element.

[0015] With this configuration, the common use of the solenoid coil facilitates wiring and control, and further facilitates manufacturing and reduces costs. In addition, the metering valve can be driven independently only by the amount of electricity.

According to a sixth aspect of the present invention, the urging force of the shutoff return spring may be set to be smaller than the urging force of the metering return spring. As described in claim 7, the driving force acting on the shut-off valve body when the common solenoid coil is energized may be set to be stronger than the driving force acting on the metering valve body.

According to the sixth and seventh aspects of the present invention, the shutoff valve can be more easily opened than the metering valve with a simple configuration, and can be driven with a smaller current. The invention according to claim 8 is characterized in that an elastic member for sealing is provided on the shutoff valve body provided at a position different from the metering valve body.
Therefore, the sealing performance can be enhanced, and the deterioration and settling of the sealing elastic member due to the adiabatic expansion of the gas accompanying the opening and closing of the metering valve body can be prevented.

The invention according to claim 9 is characterized in that the shut-off valve element and the metering valve element are operated independently. Therefore, the number of times of contact of the shutoff valve with the valve seat can be made different from the number of times of contact of the metering valve with the valve seat, and wear and deformation of the cutoff valve formed of an elastic material can be suppressed.

The invention according to a tenth aspect is characterized in that the shut-off valve element and the metering valve element are operated integrally. Thus, the metering valve can be used as a stopper for the shut-off valve, and the structure of the fuel injection device can be simplified.

[0020] The invention according to claim 11 is characterized in that the seat diameter of the shutoff valve body is larger than the seat diameter of the metering valve body. Therefore, the shut-off valve does not have the minimum flow passage area, and when the gas fuel passes through the shut-off valve, the temperature change due to the expansion of the gas fuel can be suppressed. it can.

According to a twelfth aspect of the present invention, the shut-off valve element opens when the ignition is turned on, and the metering valve element opens when the fuel is injected. Therefore, fuel injection can be performed with simple control while preventing fuel leakage.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a gas injector according to the present embodiment as a fuel injection device. The housing 1 of the gas injector is composed of a main housing 2, an upper housing 3 arranged above the main housing 2, and a lower housing (metering unit body) 4 arranged below. The main housing 2 has a substantially cylindrical shape and is made of a magnetic material. The upper housing 3 and the lower housing 4 are also substantially cylindrical. Main housing 2
The upper housing 3 and the main housing 2 are caulked together, and the main housing 2 and the lower housing (adjustment unit body) 4 are caulked via a hollow disk-shaped spacer 5. Gas fuel mainly passes through the inside of the housing 1 composed of the cylindrical members 2, 3, and 4, and is injected into the engine. That is, a fuel passage is formed in the housing 1, and one end (upper end) of the fuel passage is formed in the fuel passage.
Fuel supply unit 6 to which gas fuel of 4 to 6 atm is supplied
At the same time, the other end (lower end) is a fuel injection hole 7 for injecting a gas fuel of 1 atm.

In a fuel passage formed in the housing 1, a normally closed type electromagnetic on-off valve (shutoff valve) VAL1 is provided on the upstream side, and a normally closed type electromagnetic on / off valve (metering valve) is provided on the downstream side. ) VAL2 is provided independently. The shut-off valve VAL1 is for shutting off gas fuel when the engine is stopped, and the metering valve VAL2 is for adjusting the injection amount during engine operation.

The details will be described below. Upper housing 3
A filter 9 is disposed in the fuel passage 8 in the inside. Further, a cylindrical core 10 is fixed in the main housing 2, and a shutoff solenoid coil 11 is mounted above the outer periphery of the cylindrical core 10, and a metering solenoid is provided below the outer periphery of the cylindrical core 10. The coil 12 is mounted. That is, the coil is wound around the resin-made cylindrical spool 11a, and the resin-made cylindrical spool 12a is formed.
Is wound with a coil. A cylindrical adjuster 14 is fixed in the through hole 13 of the cylindrical iron core 10.
As shown in FIG. 2, which will be described later, the through holes 13 and the adjusters 14 are fixed by screws cut over their entire lengths, so that the urging forces of the return springs 18 and 29 can be adjusted.

Above the cylindrical iron core 10 in the housing 1, a valve body storage chamber (cylinder chamber) 15 is formed.
A cylindrical shutoff valve (shutoff valve core) 16 is slidably accommodated in the valve housing chamber 15. More specifically,
As shown in FIG. 2, the shutoff valve body 16 is made of a magnetic material, and a guide 17 is provided on an outer peripheral surface thereof.
As a result, the shutoff valve element 16 slides in the valve element storage chamber 15. Notch 17 for allowing fuel to pass through part of guide 17
a is formed. That is, in the plan view shown in FIG. 3, four notches 17a are formed on the outer peripheral surface of the guide 17, and the fuel passes through the notches 17a. Similarly, four notches (corresponding to 17a in FIG. 3) are also formed on the outer peripheral surface of the adjuster 14 as described with reference to FIG. 3, and the fuel passes through the notches. A shut-off return spring 18 is interposed between the shut-off valve body 16 and the adjuster 14 in FIG. 2, and the shut-off valve body 16 is urged upward by the return spring 18, that is, toward the valve closing side. Have been. With this urging force, the shutoff valve 16
The rubber sheet 19 provided on the upper surface is pressed against the valve seat 20, and the shutoff valve body 16 is seated. As described above, the rubber sheet 19 as a nonmetal having elasticity is disposed on the seal portion of the shutoff valve body 16.

The cut-off valve 16 shown in FIG. 2 is formed with a concave portion 21 which is opened on the lower surface, and a through-hole 22 is provided on the bottom of the concave portion 21 to communicate with the upper surface of the cut-off valve 16. . The upper rod 1 of the adjuster 14 is provided in the recess 21.
4a, the outer peripheral surface of the upper rod body 14a and the inner peripheral surface of the recess 21 are sealed by a sealing material 37 such as an O-ring provided on the outer peripheral surface of the upper rod body 14a. When the rubber sheet 19 of the shutoff valve body 16 is seated on the valve seat 20, a gap is formed between the end surface of the upper rod body 14 a of the adjuster 14 and the bottom surface of the concave portion 21 of the shutoff valve body 16. The lower end opening of the through hole 22 of the shutoff valve body 16 is open. When the rubber sheet 19 of the shutoff valve body 16 is seated on the valve seat 20 in this manner, a hollow portion R1 is formed inside the concave portion 21.

Then, as shown in FIG. 1, the shut-off valve body 16 is attracted to the cylindrical iron core 10 against the urging force of the shut-off return spring 18 by the energization of the shut-off solenoid coil 11, and the shut-off solenoid coil 11 is turned on. The valve element 16 moves down, and as shown in FIG.
From which fuel can pass.

Thus, the electromagnetic shut-off valve VAL1 for shutting off gas fuel when the engine is stopped is configured. The shut-off valve VAL1 is provided with the recess 2 as described above.
1, an inward opening structure using a through hole 22, a rod 14a, and the like. That is, the shut-off valve body 16 is formed with the through-hole 22 extending from the downstream side of the fuel toward the upstream side, and the adjuster 14 covering the downstream-side opening of the through-hole 22.
By contacting the upper rod body 14a (stopper) with the shutoff valve body 16 as shown in FIG. 4, the valve opening state can be maintained.

On the other hand, as shown in FIG. 1, a lower housing in the main housing 2 and a lower housing (adjusting unit body) 4
A metering valve core 23 and a needle 24 are movably housed therein. The cylindrical metering valve core 23 is made of a magnetic material and slides on the inner peripheral surface of the main housing 2. A needle 24 is provided inside the cylindrical metering valve core 23.
Are connected and fixed. The needle 24 is made of stainless steel, and slides on the inner peripheral surface of the lower housing (metering unit body) 4 by guides 25 and 26. The conical seat 27 at the distal end of the needle 24 faces the valve seat 28. A metering return spring 29 is interposed between the metering valve core 23 and the adjuster 14, and the metering valve core 23 and the needle 24 are lowered by the return spring 29, that is, the valve closing side. Has been energized. With this urging force, the seat portion 27 of the needle 24, which is a metering valve, is pressed against the valve seat 28 and is seated.

The needle 24 is disposed so as to pass through the hollow disk-shaped spacer 5, and the needle 2
4 is provided with a flange 30 below the spacer 5.

Then, the aforementioned solenoid coil for metering 1
By the energization of 2, the metering valve core 23 is attracted to the cylindrical iron core 10 against the urging force of the metering return spring 29, the metering valve core 23 and the needle 24 move upward, and the needle 24 seats. The portion 27 is separated from the valve seat 28 so that fuel injection is performed.

In this way, the electromagnetic metering valve V2 for metering the gas fuel injection amount during engine operation is configured. A connector 31 made of a synthetic resin is provided on the outer periphery of the upper housing 3. Terminals 32 and 33 are buried in the connector 31, and
One end of each of the solenoids 2 and 33 is electrically connected to a solenoid coil 11 for disconnection and a solenoid coil 12 for adjustment. The other ends of the terminals 32 and 33 are connected to an electronic control unit (ECU) (not shown) via a wire harness. Therefore, an excitation current is passed from the electronic control device to the shut-off solenoid coil 11 and the metering solenoid coil 12 through the terminals 32 and 33 to thereby shut off the shut-off valve VAL.
1. The metering valve VAL2 can be driven.

In this embodiment, the fuel is supplied from the gas fuel supply section 6 in FIG. 1 → the gap between the rubber sheet 19 of the shut-off valve body 16 and the valve seat 20 in FIG. 4 → the notch 17a of the guide 17 → the adjuster 14 Notch formed on outer periphery → needle 24 in FIG.
Flows from the outer peripheral surface to the gap between the seat portion 27 of the needle 24 and the valve seat 28 → the fuel injection hole 7.

Next, the operation of the gas injector thus configured will be described. Gas fuel at 3 to 8 atm is sent from a fuel tank (not shown) to a gas fuel supply unit 6 in FIG. 1 via a regulator (not shown). Dust and the like in the fuel flowing into the injector are removed by the filter 9, and the fuel reaches the shutoff valve VAL <b> 1 after passing through the filter 9. When the shut-off solenoid coil 11 is not energized by an electronic control unit (not shown), the shut-off valve 1
As shown in FIG. 2, the rubber sheet 19 of FIG. 6 is seated on the valve seat 20 by the spring force of the shut-off return spring 18 to reliably shut off gas fuel. At this time, since the shutoff valve body 16 has an inward opening structure, gas fuel (pressurized fuel) enters the hollow portion R1 as shown in FIG. 2, and the force applied to the shutoff valve body 16 by the gas fuel pressure. Is applied not only downward but also upward from the hollow portion R1, that is, in the same direction as the spring force of the shutoff return spring 18, so that the downward force acting on the shutoff valve body 16 is reduced by the pressure of the gas fuel. Therefore, the spring force of the shut-off return spring 18 for seating the rubber sheet 19 on the valve seat 20 against the downward force acting on the shut-off valve body 16 due to the pressure of the gas fuel can be reduced.

At this time, the sealing portion of the shut-off valve body 16 uses a rubber sheet 19 and has a highly airtight structure. Thus, fuel leakage when the engine is stopped can be reliably prevented.

From the state shown in FIG. 2, the shut-off solenoid coil 11 is energized for driving the engine. Then, the shutoff valve body 16 is sucked by the electromagnetic force, and a gap is generated between the rubber sheet 19 and the valve seat 20. Gas fuel is
This gap and the notch 17 of the guide 17 of the shutoff valve body 16
Through a, it reaches the metering valve VAL2.

The shutoff valve 16 is further attracted by the electromagnetic force generated in the shutoff solenoid coil 11, and the bottom surface of the concave portion 21 of the shutoff valve 16 and the upper end of the adjuster 14 come into contact as shown in FIG. The hollow portion R1 formed in the concave portion 21 does not exist. Then, there is no upward force generated in the shutoff valve body 16 due to the pressure of the gas fuel in the hollow portion R1. That is, the force generated by the pressure of the gas fuel acts on the shutoff valve body 16 downward. The force generated by the pressure of the gaseous fuel is such that the fuel pressure is P0, the cross-sectional area at the end face of the upper rod 14a of the adjuster 14 is Sa, and the cross-sectional area of the through hole 22 of the shutoff valve 16 is S0.
Assuming b, P0 (Sa-Sb). Other forces are balanced because the same fuel pressure is applied upstream and downstream of the shutoff valve body 16.

The rubber sheet 19 of the shut-off valve body 16 is
0, the solenoid coil 11 for shut-off
Is turned on, the shut-off valve body 16 is attracted by the electromagnetic force, and the hollow portion R1 is formed while the hollow portion R1 is formed in the concave portion 21.
The upward force acts on the shut-off valve body 16 due to the pressure of the gaseous fuel. Therefore, the downward force acting on the shut-off valve body 16 is small as shown in FIG. When the portion R1 is no longer present, as shown in FIG. 5, the upward force acting on the shutoff valve body 16 due to the pressure of the gaseous fuel disappears, and the downward force acting on the shutoff valve body 16 due to the gaseous fuel pressure. Increase rapidly.

Here, the spring force of the shut-off return spring 18 that is supported by the adjuster 14 and seats the rubber sheet 19 of the shut-off valve body 16 on the valve seat 20 is set within the range of the hatched portion in FIG. Then, when the shut-off valve VAL1 is fully closed, the spring force acting upward on the shut-off valve body 16 by the shut-off return spring 18 is smaller than the downward force acting on the shut-off valve body 16 due to the gas fuel pressure. When the shutoff valve body 16 is seated on the valve seat 20, the shutoff solenoid coil 11 is energized, the shutoff valve body 16 is attracted by the electromagnetic force, and is fully opened to eliminate the hollow portion R <b> 1. The downward force acting on the shut-off valve body 16 due to the fuel pressure of the gas is superior to the upward spring force acting on the shut-off valve body 16 by the return spring 18 for the shut-off valve.

That is, when the engine is operated, the shutoff valve V
While the AL1 is changed from the fully closed state to the fully opened state, the shutoff solenoid coil 11 must be energized and the shutoff valve element 16 must be sucked. However, once the shutoff valve VAL1 is fully opened, the shutoff solenoid coil 11 is closed. The shut-off valve VAL1 remains open even when the power is not supplied. As a result, it is possible to prevent the temperature of the coil from increasing due to the continuous energization of the shut-off solenoid coil 11 in order to keep the shut-off valve VAL1 open during engine operation.

At this time, due to the vibration generated during the operation of the engine, a hollow portion R 1 is formed in the recess 21 of the shut-off valve body 16 (between the shut-off valve body 16 and the adjuster 14), and shut off by the shut-off return spring 18. It is conceivable that the spring force acting on the valve body 16 for the valve may exceed the force acting on the valve body 16 for the shutoff due to the pressure of the gaseous fuel, thereby closing the shutoff valve VAL1. It is preferable to supply an exciting current that does not cause a problem of high temperature to keep the shut-off valve VAL1 in the fully open state.

When the shut-off valve VAL1 is closed when the engine is stopped, a reverse current is applied to the shut-off solenoid coil 11 to apply an electromagnetic force acting on the shut-off valve body 16 upward. At this time, the shutoff valve 1 made of a magnetic material
It is preferable to use a permanent magnet for 6.

When the shut-off valve VAL1 is opened, the gas fuel passes through the gap between the valve seat 20 and the rubber sheet 19 and passes through the metering valve VAL2.
To reach. When the metering solenoid coil 12 is energized via the terminal 33 of the connector 31 by an electronic control unit (not shown), the metering solenoid coil 12 is turned on.
Generates electromagnetic force. By this electromagnetic force, the metering valve core 23 and the needle 24 of FIG. 1 rise against the spring force of the metering return spring 29 until the flange 30 of the needle 24 contacts the spacer 5. The needle 24 and the metering valve core 23 are held at this contact position by the electromagnetic force of the metering solenoid coil 12. After that, the energization of the metering solenoid coil 12 ends (the injection control signal is no longer output), and when the electromagnetic force stops acting, the needle 24 is lowered by the spring force of the metering return spring 29, and the lower portion is moved downward. It comes into contact with the valve seat 28 of the housing (metering unit body) 4. And
During the period from when the needle 24 rises to when the needle 24 descends, the gaseous fuel passes through the gap between the seat portion 27 of the needle 24 and the valve seat 28 and is injected from the injection hole 7.

Since the shutoff of the gas fuel when the engine is stopped is performed by the shutoff valve VAL1, the metering valve VAL2
In this case, the gas fuel does not have to be shut off when the engine is stopped, so that the spring force of the metering return spring 29 can be reduced, and the wear and damage of the seat portion 27 of the needle 24 can be reduced.

As described above, this embodiment has the following features. (A) As shown in FIG. 1, a shutoff valve VAL1 for shutting off gas fuel when the engine is stopped and a metering valve VAL2 for adjusting the injection amount are independently arranged. Therefore, by using a rubber sheet (made of a highly airtight material) for the seal portion of the shutoff valve body 16 of the shutoff valve VAL1, fuel leakage when the engine is stopped can be eliminated.
In the metering valve VAL2, it is not necessary to shut off the gas fuel when the engine is stopped, so that the urging force of the metering return spring 29 can be weakened, and the abrasion and damage of the seal of the valve body (needle 24) can be reduced, and the injection amount can be extended. Can be controlled precisely. In this way, even if the shut-off valve VAL1 is deformed, the influence of the deformation is unlikely to affect the metering performance, the wear and damage of the metal seal portion of the valve body (needle 24) are reduced, and the fuel when the engine is stopped is reduced. Leakage can be prevented. (B) Further, the shutoff valve 16 is a needle (a metering valve).
24, the shut-off valve 16 when the engine is running.
Moves in the same direction as the fuel flow direction, so that the shutoff valve body 16 moves to allow gas fuel to flow. Therefore,
The valve can be opened with less force than when the shut-off valve 16 is located downstream of the needle 24 and the shut-off valve 16 moves in the direction opposite to the fuel flow direction during engine operation. (C) As shown in FIG.
Urges the shut-off valve body 16 from the downstream side to the upstream side of the gaseous fuel, and the cut-off valve body 16 is formed with a concave portion 21 that opens to the downstream side. A penetrating hole 22 is formed, and an upper rod body 14 a of the adjuster 14 is disposed in the concave part 21.
When the valve 6 (the shut-off valve VAL1) is closed, the end face of the rod 14a separates from the bottom surface of the recess 21 and the shut-off valve 16 (the shut-off valve V1).
When the valve AL1) is opened, the end face of the rod 14a contacts the bottom surface of the recess 21 so as to close the through hole 22. That is, when the shut-off valve VAL1 is closed, the end face of the rod 14a is separated from the bottom surface of the recess 21. When the shut-off valve VAL1 is opened, the end face of the rod 14a contacts the bottom face of the recess 21 and the through-hole 2 is formed.
Block 2. By opening inward in this manner, the valve can be kept open by fuel pressure after the valve is opened.

Further, by making the valve structure of the shut-off valve VAL1 inwardly open, the urging force of the shut-off return spring 18 can be reduced (weakened) by utilizing the pressure of the fuel, and will be described with reference to FIG. By adjusting the spring force as described above, the shut-off valve VAL1 can be operated even when the shut-off solenoid coil 11 is not continuously energized during engine operation.
Can be kept open, and it is possible to prevent the temperature of the shut-off solenoid coil 11 from becoming high due to heat generation of the shut-off solenoid coil 11.

When the shut-off valve VAL1 has an inward-opening structure, the shut-off valve element 16 is driven by energizing the shut-off solenoid coil 11. At this time, the solenoid coil 11
Can be made smaller after and after the valve is opened. (D) Since the material of the seal portion of the shutoff valve body 16 is a non-metallic rubber sheet 19 and the material of the seal portion of the needle 24 is a metal stainless material, adiabatic expansion occurs near the injection hole during injection. Although the seal part is cooled, the metering valve VAL2 is easily broken by freezing when a non-metallic material such as rubber is used, but the use of a metal (stainless steel) prevents breakage due to freezing. You.
Further, the shut-off valve VAL1 is excellent in sealing performance because rubber (non-metallic material) is used for the sealing portion of the valve body 16. (Second Embodiment) Next, a second embodiment will be described with reference to the first embodiment.
The following description focuses on the differences from this embodiment.

FIG. 6 is a sectional view of a gas injector according to the second embodiment. In the present embodiment, the gas injector of the first embodiment is applied, and the configuration is simplified while having the same effect.

More specifically, the construction is almost the same as that of the gas injector of the first embodiment, except that a solenoid coil 35 in which the shut-off solenoid coil 11 and the metering solenoid coil 12 are integrated is provided. I have. Further, only one terminal 36 receives a voltage waveform signal transmitted from an electronic control unit (not shown) for sucking the shutoff valve VAL1 and the metering valve VAL2.

The operation of the gas injector is as follows. The integrated solenoid coil 35 sucks both the valve element 16 of the shut-off valve VAL1 and the core 23 of the metering valve VAL2. That is, FIG. 7 shows an energization waveform (drive signal) of the solenoid coil 35 by an electronic control device (not shown). The period up to t1 in FIG. 7 is the engine stop period, and no current is supplied (conduction current A = 0). Then, at the start engine operation (t1 timing) by the ignition-on, solenoid coil 35 is energized by the current value A _1, which continues until t2. Here, the spring force of the metering return spring 29 is stronger than the spring force of the shutoff return spring 18.
Therefore, when energized, the electromagnetic force acting on the shut-off valve element 16 is blocking valve member 16 surpasses the spring force of the cut-off return spring 18 moves at the current value A ₁ in a period of t1~t2 7 However, the electromagnetic force acting on the metering valve core 23 is weaker than the spring force of the metering return spring 29, and the metering valve core 23 does not move.

As another method for opening only the shut-off valve VAL1 without increasing the spring force of the adjusting return spring 29 than the spring force of the shut-off return spring 18, another method is to use the two return springs 18,
The spring force of 29 is the same, and the electromagnetic force acting on the shut-off valve body 16 when an exciting current flows through the solenoid coil 35 may be weaker than the electromagnetic force acting on the metering valve core 23. . Specifically, for example, a material having a lower magnetic force than the metering valve core 23 is used as the material of the shutoff valve body 16.

Then, until the timing of t2 in FIG.
The current (current value A) ₁) Is washed away,
The shutoff valve VAL1 is fully opened. Fuel injection after t2
During the control period, the software is
The solenoid coil 35 is energized. The current value at this time is A
_TwoAnd the above current value A₁Greater than (A_Two>
A ₁. With this energization, the metering valve core 23 is sucked, and the
Fuel is injected. In other words, the return spring for metering
Electromagnetic force that only overcomes the spring force of
(Force acting on the fuel core 23) to perform fuel injection.
U. As described above, the valve holding current of the shut-off valve body 16 is controlled by the metering valve.
Is smaller than the valve-holding current of the valve core 23.

As described above, by integrating (commonizing) the solenoid coils, the manufacturing process can be simplified and the cost can be reduced. Also, the metering valve V
AL2 can be driven independently.

Further, the shutoff valve body 16 of the shutoff valve VAL1 is provided.
Is attracted by the coil energization during the period from t1 to t2 in FIG. 7 and becomes a fully open state. However, since the coil is energized after t2 in FIG. A hollow portion R1 is formed between the shutoff valve body 16 and the adjuster 14, and the shutoff valve VAL1 is formed.
Does not close.

As described above, this embodiment has the following features. (A) The solenoid coil 35 that drives the shut-off valve element 16 and the solenoid coil that drives the needle 24 is shared, and the urging force of the shut-off return spring 18 is greater than the urging force of the metering return spring 29. Is set to be weaker, and the common solenoid coil 35
Since the current flowing when the shutoff valve body 16 moves is smaller than the current value flowing when the needle 24 moves, the wiring is simplified and the control is facilitated by the common use of the solenoid coil. This facilitates the manufacture and facilitates the cost reduction. (B) Alternatively, a solenoid coil 35 that shares a solenoid coil that drives the shutoff valve body 16 and a solenoid coil that drives the needle 24 is used, and the driving force acting on the shutoff valve body 16 when the coil is energized is applied to the needle 24. It is set so as to be stronger than the driving force that acts, and furthermore, the current flowing through the common solenoid coil 35 is
The same can be said if the current flowing during the movement of the needle 24 is smaller than the current flowing during the movement of the needle 24. (Third Embodiment) Next, a third embodiment will be described with reference to FIG.
This will be described with reference to FIG.

As shown in FIG. 8, a fixed core 40 made of a ferromagnetic material is housed inside a housing 41. Gas fuel is supplied to a fuel inlet 40 provided at the end of the fixed core 40.
a.

Movable core made of magnetic material (cutoff valve)
Reference numeral 42 is formed in a cylindrical shape. The movable core 42 faces the fixed core 40 in the axial direction, and is disposed so as to form a predetermined gap with the lower end surface of the fixed core 40. Movable core 42
A fuel passage hole 42a is formed on the side facing the fixed core 40, and a plurality of fuel passage holes 42b penetrating the side wall of the movable core 42 are formed. The movable core 42
Is provided with a sealing member 43 as a sealing elastic member. The seal member 43 is formed in an annular shape with fluorine rubber, and is attached to the end of the movable core 42 on the fuel injection side. The seal member 43 can contact a valve seat 44 a provided on the annular valve seat member 44. When the seal member 43 comes into contact with the valve seat 44a, the seal member 43 is elastically deformed to form a large seal area. Therefore, it is possible to prevent gas fuel from leaking downstream from the contact point between the seal member 43 and the valve seat 44a. Can be prevented. As described above, in the present embodiment, the seal member 43 made of a non-metal having a resilient force and made of fluororubber is disposed in the seal portion of the movable core 42.

The shut-off valve VAL1 is constituted by the movable core 42, the seal member 43, the valve seat 44a, and the like, so that fuel can pass between the seal member 43 and the valve seat 44a. The shutoff valve VAL1 is connected between the fuel inlet 40a and the fuel through hole 4
2a, 42b, the needle 45 and the fuel passage to the contact portion of the valve seat 46a are opened and closed. Here, the annular seat diameter when the seal member 43 contacts the valve seat 44a is larger than the annular seat diameter when the needle 45 described later contacts the valve seat 46a.

A needle (a metering valve element) 45 is supported by a valve body 46 so as to be reciprocally movable.
Can be annularly abutted on a valve seat 46a provided on the inner wall of the valve body 46. Needle 45
The valve body 46 is formed of metal. A chamfered portion is formed around the sliding portion of the needle 45 with the valve body 46, and gas fuel passes between the chamfered portion and the inner wall of the valve body 46.

The metering valve VAL2 is constituted by the needle 45, the valve seat 46a and the like, and the fuel can pass between the needle 45 and the valve seat 46a. The amount of fuel injected from the injection hole 46b is adjusted by the metering valve VAL2.

The other end of the needle 45 has a joint 45
a is formed. The joint 45a is joined to the inner wall of the movable core 42 over the entire circumference, and the joint 45a and the movable core 42 are laser-welded. Therefore, the needle 4
5 and the movable core 42 operate integrally.

One end of the compression coil spring 47 contacts a spring seat 42 c provided on the movable core 42, and the other end of the compression coil spring 47 contacts the bottom of the adjusting pipe 48. The compression coil spring 47 connects the movable core 42 and the needle 45 to the lower part of FIG.
That is, the seal member 43 is in contact with the valve seat 44a, and the needle 45 is urged in the direction in which it contacts the valve seat 46a.

The adjusting pipe 48 is fixed core 4
0 is pressed into the inner wall. The biasing force of the compression coil spring 47 can be adjusted by adjusting the press-fitting position of the adjusting pipe 48 during assembly.

The solenoid coil 49 is formed by winding a coil around a resin spool, and is disposed on the outer periphery of the fixed core 40. The terminal 50 is embedded in the connector 51, and when an exciting current flows from the terminal 50 to the solenoid coil 49 via a lead wire by an engine control unit (ECU) (not shown), the needle 45 and the movable core 42 The needle 45 is sucked in the direction of the fixed core 40 against the urging force, the needle 45 is separated from the valve seat 46a, and the seal member 43 is separated from the valve seat 44a.

Next, the operation of the gas injector thus configured will be described. (1) When the power to the solenoid coil 49 is turned off, the needle 45 and the movable core 42 are urged downward in FIG. 8 by the urging force of the compression coil spring 47, so that the needle 45 comes into contact with the valve seat 46a and the sealing member 43 is moved. Valve seat 44
a. When the seal member 43 comes into contact with the valve seat 44a, the fuel passage from the fuel inlet 40a to the injection hole 46b is closed. Therefore, the sealing member 43 is connected to the valve seat 4.
In the state of contact with 4a, even if there is a slight gap in the metering portion between the needle 45 and the valve seat 46a, gas fuel is not injected from the injection hole 46b and does not leak.

Further, the urging force of the spring 47 in the valve closing direction is not further applied to the seal member 43 by the contact of the needle 45 with the valve seat 46a. (2) When the energization of the solenoid coil 49 is turned on, the movable core 42 resists the urging force of the compression coil spring 47.
Is sucked into the fixed core 40, so that the needle 45 is separated from the valve seat 46a and the sealing member 43 is
4a. This opens the fuel passage from the fuel inlet 40a to the injection hole 46b, so that gaseous fuel is injected from the injection hole 46b. The gas fuel injection amount is adjusted by the lift amount and lift time of the needle 45 from the valve seat 46a.

Further, since the gas fuel is injected at a reduced flow rate through the opening between the needle 45 and the valve seat 46a, the upstream and downstream portions of the metering section comprising the contact portions of the needle 45 and the valve seat 46a are formed. , A differential pressure is generated. When the gas fuel is injected downstream of the low pressure, the temperature of the metering section decreases due to the expansion of the gas fuel. However, in the opening / closing portion including the contact portion between the seal member 43 and the valve seat 44a, the seal member 4
Since the seat diameter of No. 3 is larger than the seat diameter of the needle 45, even if the seal member 43 is separated from the valve seat 44a, the opening does not become a throttle and almost no differential pressure occurs. Therefore, even when the shut-off valve VAL1 is opened and the gas fuel passes through the shut-off valve VAL1, the temperature of the shut-off valve VAL1 does not decrease as much as that of the metering valve VAL2. Further, since the metering valve VAL2 and the shutoff valve VAL1 are provided at different positions and separated from each other, the metering valve VAL2
Can be suppressed even if the temperature of the valve drops. In other words, since the metering valve VAL2 and the shutoff valve VAL1 are provided at different positions, the shutoff valve VAL1 does not need to adjust the gas fuel, so that the seat diameter of the seal member 43 is smaller than the seat diameter of the needle 45. Can be bigger. Therefore, even if the seal member 43 is separated from the valve seat 44a, the pressure difference between the upstream and downstream is small, so that even if gas fuel passes through the opening of the shut-off valve VAL1, the temperature hardly decreases. Thereby, it is possible to prevent the seal member 43 made of fluororubber from being deteriorated due to a decrease in temperature.

In this embodiment, since the sealing member 43 made of fluoro rubber is attached to the movable core 42, when the sealing member 43 comes into contact with the valve seat 44a, the sealing member 43 is elastically deformed to increase the sealing area. Therefore, the injection of the gas fuel from the injection hole 46b can be reliably shut off. Further, since the fuel passage is opened and closed by the shut-off valve VAL1, the metering unit constituted by the contact portions of the needle 45 and the valve seat 46a does not require processing accuracy higher than that of the injector used for liquid fuel.

In this embodiment, the structure of the injector is simplified by the reciprocating movement of the needle 45 and the seal member 43 integrally. In addition, the sealing member 43 is
The number of times that the needle 45 contacts the valve seat 46a is the same as the number of times that the needle 45 contacts the valve seat 46a, but the urging force of the spring 47 is not applied to the sealing member 43 anymore due to the needle 45 contacting the valve seat 46a. Wear and deformation of the seal member due to the contact of the member 43 with the valve seat 44a can be reduced.

Further, since the movable core 42 and the needle 45 are operated integrally, the needle 45 is
And the structure can be simplified. In other words, when the shut-off valve element and the metering valve element are operated independently as in the first embodiment, the number of times of contact with the valve seat of the shut-off valve VAL1 and the valve seat of the metering valve VAL2 are set. Can be made different from each other, and wear and deformation of the shutoff valve body formed of an elastic material can be suppressed.

Since the injection amount is adjusted at the contact portion between the metal needle 45 and the valve seat 46a, which are hardly worn or deformed, highly accurate adjustment control can be maintained. here,
CNG (Compressed Natural Ga)
s: compressed natural gas) and a fuel injection device for an internal combustion engine that injects gas fuel such as LPG. .

In the fuel injection device described in Japanese Patent Application Laid-Open No. 8-61152, in which the injection amount is adjusted and the fuel passage is opened and closed by one operating portion, one contact portion of a valve body or a valve seat is provided. It is also conceivable to provide an elastic member to prevent gas fuel leakage when the valve is closed. However, by repeating the contact and separation between the valve element and the valve seat, the elastic member is pressed against the other metal contact portion with a large force, so that the elastic member is worn or deformed and the sealing performance is reduced. There's a problem.
Further, there is a problem that the desired metering characteristics cannot be maintained particularly in the initial injection due to the deformation of the elastic member. Further, since the flow rate of the gaseous fuel is reduced at the opening between the valve body and the valve seat, a differential pressure is generated between the upstream and downstream of the opening. When the gas fuel is injected to the downstream low-pressure side and expands, the temperature near the downstream side of the opening may decrease to minus several tens degrees. When the elastic member is exposed to such a low temperature, the elastic member may be deteriorated.

On the other hand, in the present embodiment, as described above, it is possible to prevent gas fuel leakage by preventing deterioration and settling due to adiabatic expansion, and to control the injection amount with high precision.

That is, the shut-off valve VAL1 and the metering valve VAL2
In the shutoff valve VAL1, the fuel passage can be reliably closed by the sealing member made of the elastic member, and the gas fuel leakage can be prevented. Further, since the seat diameter of the shutoff valve VAL1 can be increased, the differential pressure between the upstream and downstream of the shutoff valve VAL1 is small.
Therefore, when the shut-off valve VAL1 opens the fuel passage, the gas fuel passing through the opening of the shut-off valve VAL1 does not expand much and the temperature of the gas fuel does not decrease, so that the seal member is prevented from being exposed to a low temperature and deteriorated. it can. Further, the metering valve V
Since AL2 and the shutoff valve VAL1 are separated, the metering valve V
Even if the temperature of AL2 drops, the temperature drop of shutoff valve VAL1 can be suppressed.

Further, since the needle is made of metal with little wear and deformation, it is possible to maintain highly accurate control of the injection amount. Further, since the metering valve VAL2 does not require much sealing performance, machining of the needle and its valve seat is easy. (Fourth Embodiment) Next, the fourth embodiment will be described in the third embodiment.
The following description focuses on the differences from this embodiment.

FIG. 9 shows a gas injector according to this embodiment. Components that are substantially the same as those of the third embodiment are denoted by the same reference numerals. The gas injector has a fixed core 4
A throttle 48a is provided at the fuel downstream end of the adjusting pipe 48 press-fitted to zero. The gas fuel injection amount is measured by a metering means composed of the throttle 48a, the needle 45 and the valve seat 46a. The metering is basically performed by the aperture 48a. However, if the needle 45 is the valve seat 46a
Immediately after being separated from the valve seat 46a and the valve seat 46a
Immediately before abutment, the injection amount is measured at an opening formed by the needle 45 and the valve seat 46a.

Since the ratio of the metering portion formed by the contact portion of the needle 45 and the valve seat 46a of the fourth embodiment to each other in the total injection amount is lower than that of the third embodiment, It is not necessary to control the lift amount of the needle 45 with high accuracy. (Fifth Embodiment) Next, a fifth embodiment will be described with reference to a third embodiment.
This will be described in comparison with the embodiment.

FIG. 10 shows a gas injector according to this embodiment. As shown in FIG. 10, a fixed core 60 made of a ferromagnetic material is housed inside a housing 61. The gas fuel flows in from a fuel inlet 60a provided at the end of the fixed core 60.

The movable core 62 made of a magnetic material is formed in a cylindrical shape having a short bottom in the axial direction. The movable core 62 faces the fixed core 60 in the axial direction, and is disposed so as to form a predetermined gap with the lower end surface of the fixed core 60. The sealing member 63 is formed in an annular shape with fluorine rubber,
2 is attached to the fuel injection side end. Movable core 6
2, a plurality of fuel holes 62a are formed.
“a” penetrates the movable core 62, and the inner peripheral side and the outer peripheral side of the seal member 63 communicate with each other.

A solenoid coil 64 is housed in the housing 61 between the housing 61 and the fixed core 60, and the housing 61 is narrowed down to a position facing the movable core 62 in the axial direction.
A part forms the cylindrical portion 65. The cylinder portion 65 is formed of a magnetic material, and the cylinder portion 65 is formed with a valve seat 65a.
The seal member 63 can contact.

Movable core 62, seal member 63, valve seat 65
a and the like constitutes a shut-off valve VAL1.
The fuel can pass between the valve seat 65a and the valve seat 65a. When the seal member 63 contacts the valve seat 65a, the fuel passage from the fuel inlet 60a to the metering valve VAL2 described below is closed. When the sealing member 63 abuts on the valve seat 65a, the annular seat diameter is determined by the needle 66 described later.
7a is larger than the annular sheet diameter when it comes into contact with 7a.

One end of the compression coil spring 68 contacts the movable core 62, and the other end of the compression coil spring 68 contacts the bottom of the adjusting pipe 69. The compression coil spring 68 urges the movable core 62 toward the valve seat 65a. Adjusting pipe 6
9 is press-fitted into the inner wall of the fixed core 60. By adjusting the press-fitting position of the adjusting pipe 69 at the time of assembly, the urging force of the compression coil spring 68 can be adjusted.

The solenoid coil 64 is formed by winding a coil around a resin spool, and is disposed on the outer periphery of the fixed core 60. When an exciting current flows from the electronic control unit (ECU) to the solenoid coil 64 through a terminal 71 embedded in the connector 70, the movable core 62 is attracted in the direction of the fixed core 60 against the urging force of the compression coil spring 68. Then, the seal member 63 is separated from the valve seat 65a.

The housing 72 is fixed by caulking to the end of the housing 61, and constitutes an injector housing together with the housing 61. The movable core 73 made of a magnetic material is housed in the housing 72,
5, and is disposed so as to form a predetermined gap with the lower end surface of the cylindrical portion 65. Tube part 6 of movable core 73
A fuel through hole 73a is formed at the end on the fifth side.

The needle 66 is supported by the valve body 67 so as to be reciprocally movable, and the end of the needle 66 on the fuel injection side can annularly abut on a valve seat 67 a provided on the inner wall of the valve body 67. Needle 66 and valve body 67 are formed of metal.

The metering valve VAL2 is constituted by the needle 66, the valve seat 67a and the like, and the fuel can pass between the needle 66 and the valve seat 67a. A chamfered portion is formed around the sliding portion of the needle 66 with the valve body 67, and gas fuel passes between the chamfered portion and the inner wall of the valve body 67. The injection hole 6 is controlled by the metering valve VAL2.
The fuel amount injected from 7b is metered.

The other end of the needle 66 has a joint 66
a is formed. Since a chamfer is formed around the joint 66a, gas fuel can pass between the chamfer and the movable core 73. The joint 66a and the movable core 73 are laser-welded.

One end of the compression coil spring 74 contacts a spring seat 73b formed on the movable core 73, and the other end of the compression coil spring 74 contacts the cylinder 65. The compression coil spring 74 urges the movable core 73 and the needle 66 downward in FIG. 10, that is, in a direction in which the needle 66 contacts the valve seat 67a.

The solenoid coil 75 is formed by winding a coil around a resin spool, and is disposed on the outer periphery of the cylindrical portion 65. The solenoid coil 75 is electrically connected to the solenoid coil 64, and receives the same control signal from the terminal 71.

When an exciting current flows to the solenoid coil 75 from the terminal 71 via the lead wire by the electronic control unit (ECU), the needle 66 and the movable core 73 move against the urging force of the compression coil spring 74 so that the cylindrical portion 65 The needle 66 is separated from the valve seat 67a.

Next, the operation of the injector configured as described above will be described. (1) The control signals shown in FIG. 11 are input from the terminal 71 to the solenoid coils 64 and 75. The needle 66 has a compression coil spring 7 when the input voltage is Va.
4 and separates from the valve seat 67a against the urging force, and if the input voltage is Vb, it comes into contact with the valve seat 67a. The contact and separation timing of the needle 66, that is, the fuel injection timing is controlled at the same timing as in the third embodiment. (2) When the input voltage is Vb, the movable core 62 is separated from the valve seat 65a against the urging force of the compression coil spring 68. That is, the shut-off valve VAL1 opens the fuel passage from the fuel inlet 60a to the metering valve VAL2 during the operation of the engine with the ignition key turned on, and closes the fuel passage during the stop of the engine with the ignition key turned off.

In the fifth embodiment, the needle 66 forming the metering valve VAL2 and the movable core 62 forming the shut-off valve VAL1 can operate independently. Therefore, the number of times the seal member 63 contacts the valve seat 65a is greatly reduced as compared with the third embodiment, and the wear and deformation of the seal member 63 can be further reduced, so that the life of the shut-off valve VAL1 is further extended.

The same control signal is supplied to the solenoid coils 64 and 75 to supply the control valve VAL2 and the shut-off valve VAL.
1 is controlled, so that the same connector 70 as in the third embodiment is used.
Can be used. (Sixth Embodiment) Next, a sixth embodiment will be described with reference to a fifth embodiment.
The following description focuses on the differences from this embodiment.

FIG. 12 shows a gas injector according to this embodiment. Components substantially the same as those of the fifth embodiment are denoted by the same reference numerals. Solenoid coils 64 and 75 are connected to terminals 81 and 82 embedded in connector 80, respectively.
Is electrically connected to Solenoid coils 64, 75
Is supplied with a different control signal, the metering valve VAL2
And the shutoff valve VAL1 is controlled by different signals. The signals supplied to the solenoid coils 64 and 75 are obtained by decomposing the control signal shown in FIG. 11 into a pulse portion (signal of voltage Va) and a level portion (signal of voltage Vb).

That is, the control signal shown in FIG. 11 is decomposed into a level portion (signal of voltage Vb) and a pulse portion (signal of voltage Va), as shown in FIG. The level portion (signal of the voltage Vb) is applied to the solenoid coil 64, and the pulse portion (signal of the voltage Va) is applied to the solenoid coil 7.
Join 5 Therefore, the movable core 73 and the needle 66
Is the same as that of the fifth embodiment.

In the first to sixth embodiments described above,
Since the injector is provided with the metering valve VAL2 and the shut-off valve VAL1, compared with the seventh embodiment described below in which the on-off valve (reference numeral 94 in FIG. 13) is separated from the injector (reference numeral 90 in FIG. 14). The volume on the downstream side of the shut-off valve VAL1 is small. Therefore, the amount of gas fuel that may leak from the downstream side of the shut-off valve VAL1 when the shut-off valve VAL1 is closed is reduced.

In the first to sixth embodiments, the metering valve VAL2 is disposed downstream of the shut-off valve VAL1.
Unless the shut-off valve VAL1 is provided immediately below the metering valve VAL2, the shut-off valve VAL1 may be provided downstream of the metering valve VAL2.

Although the seal member is provided on the movable core side constituting the shut-off valve VAL1, a seal member may be provided on the valve seat side of the metering valve VAL2. Further, a seal member may be provided on both the movable core and the valve seat of the needle. (Seventh Embodiment) Next, a seventh embodiment will be described focusing on differences from the previous embodiments.

FIG. 14 shows a gas fuel injection device according to this embodiment. Each injector 90 has substantially the same structure as a conventional liquid injector having a metering function and a shut-off function by a common member, and measures the injection amount. Gas fuel is supplied from the fuel tank 91 filled with gas fuel to the fuel distribution pipe 9.
2 is supplied. From the fuel distribution pipe 92 to each injector 9
0 is supplied with gaseous fuel. The gas fuel supplied from the fuel tank 91 is adjusted to a predetermined pressure by a pressure regulator 93. The on-off valve (shutoff valve VAL1) 94 opens and closes a fuel passage from the fuel tank 91 to the distribution pipe 92 and the metering valve VAL2 of the injector 90. The on-off valve 94 is provided with a seal member made of an elastic material. From the electronic control unit (ECU) 95 to the injector 90
The control signal supplied to the on-off valve 94 is the same as the control signal supplied to the metering valve VAL2 and the shut-off valve VAL1 in the sixth embodiment. Therefore, the on-off valve 9
Numeral 4 supplies gas fuel to the distribution pipe 92 by opening the fuel passage only while the ignition key is on.

In the seventh embodiment, the injector 90 is provided with only the metering valve VAL2 by separating the shut-off valve VAL1, and the on-off valve 94 is provided as a common shut-off valve VAL1 for the plurality of injectors 90. Therefore, the first to first
Metering valve VAL2 of another configuration as shown in the sixth embodiment
The size is smaller than that of the injector having the valve and the shut-off valve VAL1, and the size can be made substantially the same as that of the conventional liquid injector. Thereby, the injector 9
The size of the entire gas fuel injection device including the zero and the on-off valve 94 can be reduced.

In the above description, the invention has been applied to a fuel injection system using gaseous fuel. However, the invention may be applied to a fuel injection system for injecting a liquid phase fuel such as gasoline, in particular, to a direct injection type fuel injection system. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a gas injector according to a first embodiment.

FIG. 2 is an enlarged view of a shut-off valve which is a main part of the gas injector.

FIG. 3 is a plan view of a shut-off valve which is a main part of the gas injector.

FIG. 4 is an enlarged view of a shutoff valve which is a main part of the gas injector.

FIG. 5 is a characteristic diagram showing an electromagnetic force acting on the shut-off valve.

FIG. 6 is a cross-sectional view of a gas injector according to a second embodiment.

FIG. 7 is a diagram showing signals input to the coil.

FIG. 8 is a schematic sectional view showing a gas injector according to a third embodiment.

FIG. 9 is a schematic sectional view showing a gas injector according to a fourth embodiment.

FIG. 10 is a schematic cross-sectional view illustrating a gas injector according to a fifth embodiment.

FIG. 11 is a characteristic diagram showing a control signal supplied to the gas injector.

FIG. 12 is a schematic cross-sectional view illustrating a gas injector according to a sixth embodiment.

FIG. 13 is a characteristic diagram showing a control signal supplied to the gas injector.

FIG. 14 is an overall configuration diagram of a fuel injection device according to a seventh embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Housing, 6 ... Gas fuel supply part, 7 ... Fuel injection hole, 11 ... Solenoid coil for shutoff, 12 ... Solenoid coil for metering, 14 ... Adjuster, 16 ... Valve element for shutoff,
18 ... Interrupting return spring, 19 ... Rubber sheet,
21: recess, 22: through hole, 24: needle, 29: return spring for metering, 35: solenoid coil.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02M 61/10 F02M 61/10 A (72) Inventor Motomasa Iizuka 14 Iwatani, Shimowasukamachi, Nishio-shi, Aichi Japan Automotive Parts Co., Ltd. Within the Research Institute (72) Inventor Kenji Kanehara 14 Iwatani, Shimowasukamachi, Nishio City, Aichi Prefecture Inside the Japan Auto Parts Research Institute (72) Inventor Yasuomi Tani 1-1-1, Showa-cho, Kariya City, Aichi Prefecture DENSO Corporation (72) Inventor Yukio Mori 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation

Claims (12)

[Claims] 1. A fuel injection device for injecting fuel into an engine, wherein the fuel injection device is disposed in a fuel passage, and is for shutting off fuel when the engine is stopped, and for moving the shutoff valve. A solenoid coil for shutting off, a metering valve body disposed in the fuel passage for metering an injection amount of fuel during engine operation, and a solenoid valve for metering for moving the metering valve body And a fuel injection device comprising: 2. The shut-off valve element is urged toward a valve closing side by a shut-off return spring, and the metering valve element is controlled by a metering return spring provided independently of the shut-off return spring. The fuel injection device according to claim 1, wherein the fuel injection device is biased toward a valve closing side. 3. The fuel injection device according to claim 1, wherein the shutoff valve element moves in a fuel flow direction to open the valve. 4. A through-hole extending from the downstream side of the fuel to the upstream side of the fuel is formed in the shut-off valve body, and a stopper covering a downstream opening of the through-hole contacts the shut-off valve body. 2. The fuel injection device according to claim 1, wherein the valve is kept open. 5. The shut-off solenoid coil and the metering solenoid coil are shared, and the current flowing through the common solenoid coil is such that the valve-holding current of the shut-off valve element is the opening of the metering valve element. The fuel injection device according to claim 1, wherein the fuel injection device is smaller than the valve holding current. 6. The fuel injection device according to claim 2, wherein the biasing force of the shutoff return spring is set to be weaker than the biasing force of the metering return spring. 7. The control device according to claim 1, wherein a driving force acting on the shut-off valve when the common solenoid coil is energized is set to be stronger than a driving force acting on the metering valve. Item 7. The fuel injection device according to Item 6. 8. The fuel supply system according to claim 1, wherein the fuel is gaseous fuel, and the shutoff valve body is provided at a position different from the metering valve body and an elastic member for sealing is provided. Fuel injector. 9. The fuel injection device according to claim 8, wherein the shutoff valve element and the metering valve element are operated independently. 10. The fuel injection device according to claim 8, wherein the shutoff valve element and the metering valve element are operated integrally. 11. The valve diameter of the shutoff valve body is larger than the seat diameter of the metering valve body.
A fuel injection device according to claim 1. 12. The fuel injection device according to claim 1, wherein the shutoff valve element opens when an ignition is turned on, and the metering valve element opens when an injection is performed.