JPH0419354A - Fuel injector for internal combustion engine - Google Patents

Abstract

PURPOSE:To To enable continuous performance of the engine operation even at the time when the spill valve is inoperable, by providing a construction to enable making the degree of opening of a throttle outflow means smaller than that of an electronically controlled type spill valve during normal operation thereof and mechanically determining the former degree of opening, the throttle outflow means being used for causing a spilling of fuel having been compressed by means of a plunger. CONSTITUTION:An arrangement is formed in which a spill valve 4 of electronically controlled type is disposed in a passage portion 8a for communication, to a fuel spill port 7, of a high- pressure fuel chamber 8 of a unit injector 3 in a fuel injection pump 2. In this arrangement, an electromagnetic solenoid valve 5 is driven by a controller 9 in response to signals inputted from various sensors 10, thereby opening/closing a valve portion 4a of the spill valve 4, whereby the injecting amount of fuel is controlled. On the other hand, a change-over valve 12 is installed in the course of the high-pressure fuel chamber 8 while a throttle outflow means 11 is installed in the course of a throttle outflow passage 13 formed between this change-over valve 12 and the fuel spill port 7. The throttle outflow means 11 is provided so that the fuel in the fuel chamber 8 may flow out while throttled at the time of a state wherein the passage portion 8a is communicated with the passage 13 by the valve 1. injector 1, fuel inlet 6.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a fuel injection device for an internal combustion engine in which the amount of fuel supplied is controlled by an electronically controlled spill valve.

<Prior art> Fuel injection devices that control the opening and closing of spill valves using electronic circuits are widely used, and can supply fuel appropriately according to operating conditions, thereby improving exhaust gas purification and fuel consumption. It is effective in reducing

<Problem to be solved by the invention> In the case of an electronically controlled system, normal operation may not be possible if the electronic circuit, various actuators operated by its output signals, or sensors that input the status of each part to the electronic circuit malfunction. The engine will not be able to continue operating.

For this reason, the engine is generally stopped, but stopping the engine in a marine engine can lead to accidents involving human life, such as drifting or capsizing due to transverse waves, so even in the event of a failure, the engine can still be operated and returned to the port with its own blade. It is desirable to be able to do so.

The present invention has been made in view of these problems, and aims to provide a fuel injection device equipped with mechanical backup means.

Means for Solving the Problems> In order to achieve the above object, the present invention provides a fuel injection device equipped with an electronically controlled spill valve, which includes a throttle outflow means for overflowing the fuel compressed by the plunger. The opening degree of the throttle outflow means is smaller than the normal opening degree of the spill valve and can be determined mechanically.

Further, a switching valve is provided that communicates the injector side portion of the high pressure fuel chamber with either the spill valve or the throttle outflow means.

It is desirable that the opening of the throttle outflow means described above can be adjusted to an appropriate value, and an external adjustment means that operates according to the operating condition of the engine is connected to the throttle outflow means, and the throttle outflow is controlled by this external adjustment means. The opening degree of the means may be automatically adjusted.

Furthermore, the throttle outflow means is configured by providing forced opening adjustment means for maintaining the opening degree of the spill valve at a value smaller than in normal times and at a value that allows throttling and outflow when the spill valve is inoperable, and the spill valve is configured to act as a throttle outflow means. It can also be configured to serve as both.

In addition, when the spill valve is inoperable, the switching valve automatically switches the injector-side portion of the high-pressure fuel chamber to the outflow means side. At times, the injector-side portion of the high-pressure fuel chamber may be switched to the throttling outflow means side.

In addition, in a device configured to suck fuel into the high-pressure fuel chamber only through the spill valve, when the spill valve is inoperable, the valve opens during the intake process of the engine and fuel is supplied to the high-pressure fuel chamber via the switching valve. A suction valve is provided.

<Function> Since the fuel is throttled out through the throttling outflow means which has a smaller opening than the spill valve under normal conditions, even if the spill valve becomes inoperable due to a failure of the electronic control device, it can be managed without stopping the engine. It becomes possible to perform emergency driving.

In addition, the switching valve allows switching between a normal state in which the fuel is throttled and flowed out through the spill valve and a failure state in which the fuel is throttled and flowed out through the throttle and outflow means.

Further, by adjusting the opening degree of the throttle outflow means to an appropriate value, the amount of fuel supplied in the event of a failure can be adjusted. Also,
By adjusting the opening degree of the throttling outflow means using an external adjustment means, the amount of fuel supplied is controlled according to the operating state of the engine.

Furthermore, by providing a forced opening adjustment means for the spill valve, there is no need to separately provide a throttling outflow means.

Furthermore, when the spill valve is inoperable, the switching valve automatically switches the portion of the high-pressure fuel chamber on the injector side to the throttling outflow means side, so that the engine can be switched to failure mode without stopping.

Further, even in an injection device configured to suck fuel into a high-pressure fuel chamber only through a spill valve, operation in the event of a failure is possible by providing an intake valve that opens during the intake stroke of one engine.

<Example> Next, this invention will be explained in detail.

In Fig. 1, 1 is an injector, 2 is a fuel injection pump, 3 is a unit injector in which these are integrated, 4 is a spill valve, 5 is an electromagnetic solenoid for driving the spill valve, and 6 is a fuel injection pump. 2 plunger barrel part 2a
7 is a fuel overflow port provided on the downstream side of the spill valve 4; 8 is formed to extend from the unit injector 3 to the spill valve 4 and communicate with the top 2C of the fuel compression plunger 2b; 9 is a controller equipped with a microcomputer and the like. The upper surface of the tappet 3b of the unit injector 3 is driven to be pressed by a rocker arm 3a that swings in accordance with the rotation of the engine, and the fuel is supplied from the fuel port 6 to a high-pressure fuel chamber 8 communicating with the top 2C of the plunger 2b of the injection pump 2. The compressed fuel is compressed by the fuel compression plunger 2b and injected from the injection hole 1a of the injector 1. The injection amount at this time is regulated by the controller 9 driving the electromagnetic solenoid 5 based on signals input from various sensors 10, and opening and closing the valve portion 4a of the spill valve 4 at predetermined timing. ing. In the figure, 1b is a spring receiver.

1c is a nozzle spring, 1d is a shim, and 3C is a delivery valve. The above configuration is not particularly different from conventionally known fuel injection devices.

Reference numerals 11 and 12 are a throttle outflow means and a switching valve provided according to the present invention, the switching valve 12 is installed in the middle of the high pressure fuel chamber 8, and the throttle outflow means 11 is installed between this switching valve 12 and the fuel overflow lower. It is installed in the middle of the throttle outlet passage 13 that is formed.

The switching valve 12 allows a portion 8a of the high-pressure fuel chamber 8 on the injector 1 side to communicate with the portion 8bL on the spill valve 4 side from the plunger top 2c via the communication groove 2d, and is provided with a throttle outflow means 11. It communicates with the throttle outflow path 13. The switching of the switching valve 12 may be performed either manually or automatically, and in FIG. 4 of the embodiment described later, a solenoid valve is used as the switching valve 12, and the switching valve 12 is automatically switched to the throttle outlet path 13 side when no electricity is applied. An example of this is shown below.

Further, the throttle outflow means 11 controls the fuel in the high pressure fuel chamber 8 to flow through the valve section 11a when the switching valve 12 communicates the portion 8a of the high pressure fuel chamber 8 on the injector 1 side with the throttle outflow passage 13.
The liquid is squeezed out through the filter. Squeezing outflow means 11
The valve portion 11a is configured such that its opening degree can be determined mechanically, and the opening degree is selected to be smaller than the opening degree of the valve portion 4a of the spill valve 4 in normal conditions. In the example shown in FIG. 1, the valve support 11b is a screw, and the opening degree of the valve portion 11a is adjusted by adjusting the amount of screwing. be adjusted.

This embodiment has the configuration described above, and the controller 9
If the electromagnetic solenoid 5 or the like fails and the electromagnetic solenoid 5 becomes de-energized, the valve portion 4a of the spill valve 4 remains open, and fuel cannot be injected from the injector 1 in this state. Therefore, in the event of a failure, the selector valve 12 switches the portion 8a of the high pressure fuel chamber 8 on the inductor 1 side to the throttling outflow path 13 side, and the fuel in the high pressure fuel chamber 8 is throttled and flowed out through the valve portion 11a. The injection amount is controlled by As a result, even if proper injection amount control cannot be performed as in normal conditions, it is possible to secure a certain amount of injection amount and continue emergency operation of the engine.
Even if a failure occurs in the electronic control system of a ship's engine outside the port, the ship can somehow return to port on its own, preventing a serious accident.

FIG. 2 shows another embodiment for mechanically determining the opening degree of the valve portion 11a of the throttle outlet means 11. That is, in this embodiment, the valve support body 11b is extended upward and the operation lever 1 is
1c, and operates the external adjustment means 14 according to the operating state of the engine via an appropriate link mechanism 11d;
For example, it can be connected to a centrifugal governor or a pneumatic governor that uses negative intake pressure. Note that since the unit injector 3 is common, illustration thereof is omitted.

Therefore, the valve support body 11b rotates according to the operating state of the engine and moves in the axial direction by the screw action, so that the fuel injection amount can be controlled to some extent, so that the opening degree of the valve portion 11a can be controlled to some extent as in the above-mentioned embodiment. This makes it possible to perform emergency operation of the engine more appropriately than when the value is set to a certain value in advance.

The above two embodiments are provided with the throttle outlet means 11 and the switching valve 12, but the switching valve 12 is not used in FIG.
Furthermore, this is an embodiment in which the spill valve 4 also serves as a throttle outflow means without providing a separate throttle outflow means 11.

In the figure, 15 is a valve stopper, and 16 is an adjustment shim, and the valve stopper 15 is fixed to the lower part of the valve body 4b of the spill valve 4 with a fixing screw 17 to restrict the descent of the valve body 4b. For this reason, the spill valve 4 does not open completely when the electromagnetic solenoid 5 is de-energized, and is maintained at a smaller opening than normal, allowing emergency operation of the engine in the event of a failure of the controller 9, electromagnetic solenoid 5, etc. It becomes. The adjustment shim 16 is used to adjust the opening degree at this time to an optimal value. Note that the unit insector 3 is the same as that in FIG. 1, so illustration thereof is omitted.

Figure 4 shows that the switching valve 12 automatically throttles the outflow means 1 in the event of a failure.
This is an embodiment in which it is possible to switch to the 1 side.

As shown in the figure, the switching valve 12 is an electromagnetic valve in which a switching plunger 21 is attracted by an electromagnetic solenoid 22. When the plunger 21 is attracted, it moves to the position indicated by the chain line, and when it is not attracted, it is returned by the spring 23 to the position indicated by the solid line. The plunger 21 has a switch that connects the portion 8a of the high-pressure fuel chamber 8 on the insector 1 side to the portion 8b on the spill valve 4 side at the chain line position, and communicates with the throttle outlet passage 13 at the solid line position. A passage 24 is formed. In addition, electromagnetic solenoid 2
2 is connected to a drive power source 26 via a mode changeover switch 25, and this switch 25 is kept in the on state by the controller 9 during normal operation, but if some abnormality occurs, the spill valve 4 cannot be operated normally. It is configured so that it is turned off when the condition is reached. This abnormality detection is performed by the controller 9 based on the input data from each sensor 10 and the signal from the system abnormality detection means 27 provided as appropriate.
When a system goes down due to failure and loss of control,
The mode changeover switch 25 is automatically turned off.

Therefore, if the power is turned on in normal mode,
The electromagnetic solenoid 22 is energized, the switching plunger 21 is in the chain line position, and the section 8a on the insector 1 side is in the chain line position and communicates with the spill valve 4 side section 8b, but in the abnormal mode, the switch 25 is turned off. Electromagnetic solenoid 2
2 becomes de-energized, the plunger 21 automatically returns to the solid line position, and the portion 8a is switched to the throttle outlet path 13 side.

Therefore, even when a failure occurs, the engine can be switched to emergency operation without stopping the engine, improving operability and safety.

Next, the fuel intake 6 is not provided in the plunger barrel portion of the fuel injection pump 2, and the fuel intake into the high pressure fuel chamber 8 is also controlled by the spill valve 4.
An embodiment of a fuel injection device that performs injection via the following steps will be described.

In FIG. 5, 31 is a fuel inlet provided on the spill valve 4 side in line with the fuel overflow lower, 32 is an intake valve, and this intake valve 32 is connected to a throttle outlet passage 13 in which a throttle outlet means 11 is provided. The switching valve 12 and the spill valve 4 in the bypass state
A check valve is used which is provided between the valves and which allows flow only in the direction from the spill valve 4 to the switching valve 12.

With this structure, during the intake process of the engine, the intake valve 32 is opened, and fuel supplied from the fuel port 32 is sucked into the high-pressure fuel chamber 8 and injected from the injector 1. In addition, in the event of a failure, the switching valve 12 is switched to the throttle outflow path 13 side, so that the fuel flows through the throttle outflow means 11 to the throttle flow ratio, as in the previous embodiments, and emergency operation in the event of a failure is performed.

Although each of the above embodiments concerns a unit injector 3 in which an injector 1 and a fuel injection pump 2 are integrated, the present invention also applies to an injector and a fuel injection pump that are separate bodies. Of course it can be applied.

<Effect of the invention> As is clear from the above description, this invention has the following features.

As a mechanical backup means, a throttling bath means with a smaller opening than the spill valve under normal conditions is provided, and the fuel is throttled out through this means, and the spill valve is activated due to a failure of the electronic control device. Even if the engine becomes disabled, it is possible to operate the engine without stopping it.

Therefore, it is possible to avoid engine stoppages, which can lead to accidents involving human life, especially in marine engines, and to continue operating on its own even in the event of a failure, thereby improving the reliability and safety of the system. It is.

In addition, a switching valve is provided so that the fuel can be throttled and flowed out through the spill valve during normal operation, and the fuel can be throttled and flowed out through the throttle and flow means in the event of a failure. can be controlled.

In addition, by adjusting the opening degree of the throttling flow means to an appropriate value, the amount of fuel supplied in the event of a failure can be adjusted.In particular, in the case where the opening degree of the throttling flow means is adjusted by an external adjustment means, Even during emergency operation, it is possible to control the fuel supply amount to a certain extent depending on the operating state of the engine to achieve stable operation.

Furthermore, in the case of a spill valve equipped with forced opening adjustment means,
There is no need to separately provide a throttling outflow means, the structure is simple, and the device can be provided at low cost.

In addition, when the spill valve is inoperable, the switching valve automatically switches the injector side of the high-pressure fuel chamber to the throttling outflow means side, making it possible to switch to emergency operation without stopping the engine. It is possible to avoid dangers such as engine stoppage at sea, and safety is improved.

In addition, in an injection device configured to suck fuel into the high-pressure fuel chamber only through a spill valve, it is equipped with an intake valve that opens during the intake process of the engine, so even in the case of a malfunction, even in this type of device, emergency operation becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the throttling outflow means in another embodiment, FIG. 3 is a diagram showing the configuration of the spill valve in another embodiment, and FIG. 4 is a diagram showing the configuration of the switching valve in another embodiment. FIG. 5 is a diagram showing the configuration of another embodiment. 1... Injector, 2... Fuel injection pump, 3... Unit insector, 4... Spill valve, 5... Electromagnetic solenoid, 6... Fuel inlet, 7... Fuel overflow port, 8...・
High pressure fuel chamber, 9... Controller, 11... Throttle outflow means, 12... Switching valve, 13... Throttle outflow path, 1
4. External adjustment means, 15. Valve stopper, 21.
...Switching plunger, 22...Electromagnetic solenoid, 23
...Return spring, 24...Switching passage, 25...Mode selector switch, 31...Fuel inlet, 32...Intake valve. Patent applicant Yanmar Diesel Co., Ltd. Agent
Patent Attorney Shino 1) Jinning Map No.

Claims (8)

[Claims] (1) In a fuel injection device equipped with an electronically controlled spill valve, a throttle outflow means for overflowing the fuel compressed by the plunger is provided, and the opening of the throttle outflow means is set to the normal opening of the spill valve. A fuel injection device for an internal combustion engine, characterized in that it is smaller and configured to be determined mechanically. (2) The fuel injection device for an internal combustion engine according to claim 1, further comprising a switching valve that communicates the injector-side portion of the high-pressure fuel chamber with either a spill valve or a throttle outflow means. (3) The fuel injection device for an internal combustion engine according to claim 1 or 2, wherein the opening degree of the throttle outflow means is adjustable. (4) The fuel injection device for an internal combustion engine according to claim 3, wherein the opening degree of the throttle outflow means is adjusted by an external adjustment means that operates according to the operating state of the engine. (5) The internal combustion engine according to claim 1 or 2, wherein the throttle and outflow means is provided with forced opening adjustment means for maintaining the opening of the spill valve at a value smaller than in normal times and at a value that allows throttling and outflow when the spill valve is inoperable. Engine fuel injection system. (6) The fuel injection system for an internal combustion engine according to claim 2, wherein the switching valve is configured to automatically switch the portion of the high-pressure fuel chamber on the injector side to the outflow means side when the spill valve is inoperable. (7) The fuel injection device for an internal combustion engine according to claim 6, wherein the switching valve is a solenoid valve, and the portion of the high-pressure fuel chamber on the injector side is switched to the throttle outflow means side when no current is applied. (8) It is configured so that fuel is sucked into the high-pressure fuel chamber only through the spill valve, and when the spill valve is inoperable, it opens during the engine's suction process and supplies fuel to the high-pressure fuel chamber through the switching valve. 3. The fuel injection system for an internal combustion engine according to claim 2, further comprising a suction valve that provides a fuel injection system for an internal combustion engine.