JPH10131828A - Injection valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection valve device which is a small and compact device, can change or adjust freely an injection element and is suitable for fuel and water injection, by arranging in the injection valve a system to control the injection element such as an injection amount, injection timing and injection pattern. SOLUTION: In an injection valve which perform injection from an injection hole 5a by the lift of a needle valve 4, a spring by which the needle valve 4 is energized in a valve closing direction, an oil chamber 10 to which operating oil pressurized to a predetermined pressure is introduced, an actuator 8 which is arranged to be placed in the oil chamber 10 and by which the needle valve 4 is opened when force by pressure of operating oil in the oil chamber 10 overcomes the pressing force of the spring, and a solenoid valve 11 which is arranged in an operating oil passage connected to the oil chamber 10 of the actuator 8 so as to open and close the operating oil passage, are arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection valve device for fuel, water and the like used in an internal combustion engine, particularly a diesel engine.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional fuel injection valve for a diesel engine. In FIG. 2, 1 is an injection valve main body, 5 is a nozzle fixed to the main body 1 by a nozzle nut 21, 5a is an injection hole opened at the tip of the nozzle 5, 2 is a fuel injection pump (not shown). Reference numeral 3 denotes a fuel reservoir, 4 denotes a needle valve which is opened by fuel pressure in the fuel reservoir 3, 6 denotes a needle valve spring, and 7 denotes a push rod.
The fuel discharged from the fuel injection pump passes through a fuel passage 2 provided in the injection valve body 1 and passes through a fuel reservoir 3.
Accumulate in When the fuel reaches a predetermined pressure, the needle valve spring 6
When the resilience is overcome, the needle valve spring 6 is compressed and lifted via the needle valve 4 and the push rod 7, and fuel is injected into the cylinder from the injection hole 5a of the nozzle 5. At this time, the fuel injection amount and the injection timing are adjusted by the fuel injection pump.

Further, an injection valve in which a needle valve is opened and closed by a solenoid is proposed in Japanese Patent Publication No. 4-52865. In the present invention, the operating fuel is gradually discharged from the power cylinder working chamber when the solenoid valve is excited, and the power cylinder is made to flow to the power cylinder when the solenoid valve is de-energized. A flow control means for promptly injecting the fuel is provided to gradually open the needle valve and to quickly close the needle valve.

[0004]

A plurality of liquids, for example,
In an engine that injects water into a cylinder together with fuel in order to reduce NO _x (nitrogen oxides), a fuel injection pump system for pressurizing and pumping the fuel and water of the same or larger size are used. Equipped with injection systems, each system controls the amount and timing of fuel and water injection.

For this reason, in a vehicle diesel engine or the like having a limited space, the fuel injection system and the water injection system are separately provided as described above, and an injection system for controlling the injection amount and the injection timing is provided. It is difficult to adopt because of space. In addition, improvement of fuel performance and NO
_In order to reduce _X, it is required that the fuel and water injection pattern can be freely changed. However, the fuel and water injection system of the related art cannot freely control such an injection pattern.

In the invention of Japanese Patent Publication No. 52865/1992, since the needle valve closes promptly, the rise of the injection rate at the end of the injection is sharply stimulated, and the cutoff of the injection becomes good.
Since the rise at the beginning of the injection is slow, it is difficult to obtain an injection mode with a sharp rise that requires high acceleration.

In view of the above-mentioned problems of the prior art, the present invention provides a system for controlling an injection element such as an injection amount, an injection timing, and an injection pattern in an injection valve.
An object of the present invention is to provide an injection valve device suitable for fuel and water injection, in which the injection element can be freely changed or adjusted with a small and compact device.

[0008]

SUMMARY OF THE INVENTION In order to solve the above technical problems, the present invention introduces a liquid such as fuel or water pressurized to a predetermined pressure into a liquid reservoir by an injection pump, and opens a needle valve. With this arrangement, in the injection valve configured to inject the liquid from the injection hole by communicating the liquid reservoir with the injection hole, a predetermined pressure is applied to a spring that biases the needle valve in the valve closing direction. An oil chamber into which the pressurized hydraulic oil is introduced, and provided in front of the oil chamber, when the force of the hydraulic oil in the oil chamber overcomes the pressing force of the spring and compresses the spring. An actuator that opens the needle valve and closes the needle valve while shutting off the supply of hydraulic oil to the oil chamber, and an operating oil path connected to the oil chamber of the actuator. An injection valve device comprising: a solenoid valve for opening and closing an oil passage. Suggest.

Preferably, in addition to the above invention, a signal of an engine operating state such as an engine speed and an engine load is input, and a controller for opening and closing the solenoid valve based on the signal is provided. The actuator is controlled in cooperation with the solenoid valve.

According to this invention, a liquid such as fuel pressurized to a predetermined pressure by the injection pump is introduced into the liquid reservoir of the injection valve and acts on the needle valve. Otherwise, the needle valve will not open. Then
When the solenoid valve is opened by the controller, the hydraulic oil pressurized to a predetermined pressure is guided to the oil chamber and overcomes the elasticity of the actuator and the spring to be pushed up, whereby the needle valve is actuated by the liquid pressure in the liquid reservoir Is pushed up and the valve is opened, and the liquid is ejected from the injection hole. When the controller closes the solenoid valve, the pressure in the oil chamber is released, and the needle valve is pushed down via the actuator by the force of the spring to close the valve.

As described above, in the present invention, even when the high-pressure liquid is supplied to the liquid reservoir, the needle valve is normally closed, and only when the actuator is actuated via the solenoid valve. The valve is configured to open and the needle valve to close when the actuator is finished, so that the injection amount, injection timing and injection pattern can be freely changed in the injection valve. Becomes Accordingly, it is possible to easily obtain the injection mode in which the rising of the injection is gradual as in the prior art of Japanese Patent Publication No. 4-52865, and also easily obtain the injection mode in which the rising of the injection that requires high acceleration is rapidly induced. Can be.

Further, if two sets of the above-mentioned injection valve devices are provided, one of which injects fuel and the other injects water,
The injection device is small and compact, the fuel injection is controlled by the plunger and fuel cam of the fuel injection pump, and the control valve device provided in the water supply system of the water injection device controls the water injection like the conventional one. Does not require extensive equipment.

Further, since the needle valve is closed as long as the actuator is not operated, even if a failure occurs in the actuator, the solenoid valve and its control system, liquid such as fuel and water does not flow into the cylinder. The occurrence of a problem due to such a phenomenon is prevented.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just

FIG. 1 shows an example of an injection valve device for a diesel engine according to an embodiment of the present invention. In FIG. 1, 1 is an injection valve main body, 5 is a nozzle having an injection hole 5a formed at the tip, 2
Reference numeral 1 denotes a nozzle nut for fixing the nozzle 5 to the main body 1, and 4 denotes a needle valve for opening and closing the injection hole 5a. Reference numeral 2 denotes a liquid passage into which a liquid (in this case, fuel) pressurized to a high pressure is introduced from an injection pump (not shown). The liquid passage 2 is connected to a liquid reservoir 3 formed in the nozzle 5.

Reference numeral 8 denotes an actuator provided inside the injection valve main body 1. The lower end of the actuator 8 is connected to the head of the needle valve 4 via a push rod 7. Reference numeral 10 denotes an oil chamber formed facing the operation surface of the actuator 8 in the injection valve body 1, and reference numeral 11 denotes a solenoid valve.
Numeral 0 is connected to the solenoid valve 11 via an oil passage 9.

Control oil is supplied to the solenoid valve 11 from a control oil pump (not shown) via an oil passage 13. 1
Reference numeral 2 denotes a controller to which a detection signal of an engine operation state quantity such as an engine speed N and an engine load L is input, and a solenoid valve opening signal calculated based on the detection signal is transmitted to the solenoid valve 11 via a circuit 23. It is supposed to.

Reference numeral 6 denotes a spring for the actuator 8, which presses the needle valve 4 in the valve closing direction (downward) via the actuator 8 and the push rod 7. Reference numeral 15 denotes a spring case, and 14 denotes a bush on which the outer periphery of the actuator 8 slides.

Next, the operation of the injection valve having such a configuration will be described. A high-pressure liquid (hereinafter referred to as fuel) supplied from an injection pump (not shown) is supplied to a liquid passage 2 of the injection valve body 1.
And passes through it to the liquid sump 3. On the other hand, an actuator 8 provided on the upper part of the injection valve body 1
When the operating oil pressure is not introduced into the oil chamber 10 below this, the spring 6 presses the needle valve 4 via the push rod 7 in the valve closing direction. Therefore, the actuator 8 closes the needle valve 4 even if the high-pressure fuel is introduced into the liquid reservoir 3 as described above and acts in a direction to push up (open) the needle valve 4.

Based on detection signals of the engine operating state such as the engine speed N and the engine load L, the controller 1
2 transmits a valve opening signal to the solenoid valve 11, the solenoid valve 11 is opened, and the operating oil in the oil passage 13 passes through the solenoid valve 11 and the oil passage 9, enters the oil chamber 10 of the actuator 8, and It depresses upward by overcoming the pressing force of the spring 6. As a result, the force for pressing the needle valve 4 downward is released, and the needle valve 4 is pushed upward by the fuel pressure in the liquid reservoir 3 to open the valve. It is injected into the cylinder.

Next, when the solenoid valve 11 is closed by the controller 12 at an appropriate injection end timing, the solenoid valve 1 is closed.
1, the oil chamber 10 and the oil passage 9 are communicated with an oil discharge passage (not shown), the pressure oil in the oil chamber 10 is discharged to the oil discharge passage, and the pressure of the oil chamber 10 is reduced to the atmospheric pressure. Drops nearby. As a result, the actuator 8 is returned downward by the attachment force of the spring 6, closes the needle valve 4 via the push rod 7, and the injection ends.

As described above, the injection device according to the embodiment of the present invention controls opening and closing of the needle valve 4 by the actuator 8 operated by the controller 12 and the solenoid valve 11, and is similar to the injection device according to the prior art. Meanwhile, when fuel oil pressure acts on the needle valve 4, the needle valve 4 resists the pressing force of the needle valve spring,
It is not configured to open automatically, and even if the fuel oil pressure is acting on the needle valve 4, unless the operating oil pressure acts on the actuator 8 and the pressing force of the needle valve 4 is released, the needle valve is not opened. Numeral 4 is configured not to open.

Therefore, in the injection valve device of the present invention,
By controlling the actuator 8 by the controller 12 and the electromagnetic valve 11, the fuel injection amount, fuel injection timing and fuel injection pattern can be freely changed.

Further, unlike the conventional fuel injection pump, it is not necessary to control the injection amount and the injection timing by the notch of the cam and the plunger interlocked with the engine.
The fuel injection can be freely controlled only by the injection valve.

Therefore, if such an injection valve is used for fuel injection as described above and is used as a water injection device in which fuel is replaced by water, the injection amount of fuel and water, injection timing In addition, a compact fuel and water injection device whose injection pattern can be freely and accurately controlled can be obtained, and a large fuel and water injection device unlike the conventional one is not required.

Normally (when the actuator 8 is not operated), the needle valve 4 is closed. Therefore, even if the actuator 8 or the solenoid valve 11 or the like fails, liquid such as fuel, water, etc. Is prevented from flowing into the inside.

[0027]

As described above, according to the present invention, the injection of a liquid such as fuel or water into a cylinder is performed by an electromagnetic valve provided at an injection valve and an actuator operated by the solenoid valve.
Because it controls, the injection amount, injection timing and injection pattern can be freely changed or adjusted to an appropriate value on the injection valve side, as in the case of a conventional fuel injection pump or an injection control device using a water injection control valve, Fuel and water injection and control thereof can be performed with a small and compact device without requiring a large-scale device.

Further, since the needle valve is always closed when the actuator is not operated, it is possible to prevent a problem that a liquid such as fuel or water flows out of the injection valve into the cylinder.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an injection valve according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional fuel injection valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection valve main body 2 Liquid passage 3 Liquid reservoir 4 Needle valve 5 Nozzle 5a Injection hole 6 Spring 8 Actuator 9 Oil passage 10 Oil chamber 11 Solenoid valve 12 Controller

Claims (2)

[Claims] 1. A liquid such as fuel or water pressurized to a predetermined pressure is guided to a liquid reservoir by an injection pump, and a needle valve is opened. A spring that biases the needle valve in the valve closing direction, an oil chamber into which hydraulic oil pressurized to a predetermined pressure is introduced, and The needle valve is opened only when the force by the pressure of the hydraulic oil in the oil chamber overcomes the pressing force of the spring and compresses the spring, while the hydraulic oil into the oil chamber is opened. And a solenoid valve provided in a hydraulic oil passage connected to an oil chamber of the actuator to open and close the hydraulic oil passage. Injection valve device. 2. A controller for inputting and receiving a signal of an engine operation state such as an engine speed and an engine load, and for opening and closing the solenoid valve based on the signal.
Injection valve device as described.