JPS60122268A - Fuel feeding device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent the overrun of an engine by detecting the position of a free piston and controlling the quantity of fuel fed into a pump chamber based on the detected result, in the captioned device which controls the quantity of fuel by allowing said fuel to spill by means of the movement of said free piston. CONSTITUTION:When a solenoid valve 18 is excited and opened by a computer 29, a free piston 16, which is subjected to the pressure in a pump chamber, is moved rightward and brough in contact with a gap sensor 17. At this time, a small hole 191 is connected to a spill passage 15 and fuel is stopped from being fed into an injection valve 13 from the pump chamber 9. Should the solenoid valve 18 fail, leaving the free piston 17 in a stationary state, the gap sensor 17 fails to output a signal, and a first and a second fuel stop valve 22, 24 are made closed and opened respectively by the computer 20. Therefore, a limited quantity of fuel is fed into the pump chamber 9 through a small diameter fuel feeding passage 23, preventing the overrun of an engine.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fuel supply system for an internal combustion engine, and more particularly to a safety device for a spill mechanism that reduces fuel pressure in a pump chamber to stop fuel supply to a fuel injection valve. It is something.

Prior Art A type of fuel injection pump having a spill mechanism is known as a fuel supply device for an internal combustion engine. a plunger for changing the volume of a pump chamber formed in the first cylinder and forcefully feeding the fuel in the pump chamber to the fuel injection valve; a spill passage for circulating the fuel in the pump chamber back to the fuel storage section; A free piston that is slidably installed in a second cylinder formed in the middle of the spill passage and closes communication between the spill passage and the pump chamber, and the free screw!・A solenoid valve that fully controls the opening and closing of the engine, a free piston position detection mechanism that detects the position of the free piston, and a computer that receives each detection signal of the engine rotation speed, accelerator opening, and the free piston position. j::j L/, the period of fuel recirculation to the fuel reservoir is detected from the information on the position of the free piston, and the computer detects the period of recirculation of fuel to the fuel reservoir from the information on the position of the free piston, A fuel supply device has been developed in which the free piston is used to block off the spill passage f, and when fuel is recirculated to the fuel storage part, the free piston is used to control the solenoid valve to fully open the spill passage f. (Special application 1987-1
No. 60776). And in this device! '1f
ll 1ic2 It is necessary for the free piston to slide 1, and therefore, if the solenoid valve breaks down, the solenoid valve lead wire is disconnected, or the free piston is locked in the second cylinder. If fuel is not spilled and the back and forth movement of the plunger in the first cylinder causes the fuel to be injected, the engine may overrun by 21-%. In addition, if the free piston is locked in the middle of the second cylinder and the pump chamber and the spill passage remain in communication, no fuel is supplied to the engine, the engine stops, and the vehicle This means that you will not be able to drive yourself.

Purpose of the Invention The present invention was made in order to solve the above-mentioned problems in the frk fuel supply device that was developed by the company itself, and its purpose is to improve the engine speed and accelerator opening. If it is detected that the free piston position detection mechanism cannot correct the operation of the solenoid valve, which is performed depending on the An object of the present invention is to provide a fuel supply system for an internal combustion engine with improved performance that ensures the supply of JP'j fuel necessary for running the engine.

Structure of the Invention In order to achieve the above object, the structure of the present invention is as follows.
a sylanger that reciprocates in the first cylinder to change the volume of a pump chamber formed in the first cylinder and forcefully feeds the fuel in the pump chamber to the fuel injection valve; and a sylanger that recirculates the fuel in the pump chamber to the fuel storage section. a free piston that is slidably installed in a second cylinder formed in the middle of the spill passage and opens and closes communication between the spill passage and the pump chamber; and a free piston that opens and closes communication between the spill passage and the pump chamber. a solenoid valve that controls the free piston, a free piston position detection mechanism that detects the position of the free piston, and a computer into which detection signals of the engine rotation speed, accelerator opening, and the free piston position are input, The computer causes the electromagnetic to operate so as to cause the free piston to close the spill passage when fuel is supplied to the fuel injection valve, and to cause the free piston to open the spill passage when fuel is returned to the fuel reservoir. In a fuel supply device for an internal combustion engine that controls a valve, a first fuel passage through which a large amount of fuel can pass and a first fuel passage through which a large amount of fuel can pass and a small amount of fuel are provided in the middle of the fuel supply passage from the fuel storage section to the pump chamber. At the same time, the second fuel passage is completely installed, and the first fuel passage is installed. Second
A first fuel stop valve and a second fuel stop valve are provided in the fuel passage for opening and closing the passage, respectively, and a first fuel stop valve and a second fuel stop valve for opening and closing the passage are respectively provided,
When the drive signal and the free piston position detection signal are not detected in synchronization, the first fuel stop valve is closed and the second fuel stop valve is opened; and the first invention Further, a third fuel stop valve for opening and closing the spill passage is provided in the middle of the spill passage, and the third fuel stop valve is closed at the same time as the second fuel stop valve is opened. It depends on this.

EMBODIMENTS Embodiments of the present invention will be explained below with reference to the drawings.

Figure 1 shows l? Distributed injection, known as the Tussi VE type;
l? C1 based on nf0! A first embodiment to which the present invention is applied will be shown.

A part known as a non-distribution type will be explained.

The syranger 1 performs reciprocating motion within the first shilling Ja while rotating at +4 rills in the Ennon field. The rotational force of the granger 1 is provided by a drive shaft 2 which is driven by an engine via gears or a timing belt. The force for reciprocating motion is provided by a face cam 3 that is integrally provided with the planter 1. That is, the face cam 3 is always urged leftward by the spring 5 and engaged with the roller 4, and rotates around the M center to reciprocate according to the shape of the face. The roller 4 is supported by a roller ring 41.

This roller ring 41 is rotated by a lever 6 and rotates by changing its relative position with the pump casing 7, thereby making it possible to adjust the timing of the reciprocating movement of the granger 1. The force for rotating the low ring 41 is provided by the tie piston 8. In FIG. 1, the timer piston 8 is shown rotated by 90 degrees.

The plant 1 has the same number of intake boats 102 as the number of engine cylinders and one distribution number on its outer circumference. - When the syringe l moves to the right, that is, when the pump chamber 9 formed at its tip is in the compression stroke, the distribution port 101 is a distribution passage whose number is equal to the number of engine cylinders. When the granger 1 moves to the left, that is, when the pump chamber 9 is in the suction stroke, one of the suction ports 102 connects to one suction passage 1.
1 and conducts fuel intake. Each of the distribution passages 10 can communicate with an external injection jT13 via a delivery valve 12. Delivery valve ■2 (l″ii spring 12
1 and opens, and has both the functions of a check valve and a suction Jj'< L valve. The suction passage 11 opens into a constant pressure chamber 71 which is a fuel storage section surrounded by the pump casing 7.

Distribution passage 10. Both the suction passage 11 and the suction passage 11 are machined into the FE pump casing 7. The above is one function of a structure known as a distributed type.

First, the qI characteristic part of the present invention will be explained.

14 is a spill machine 'j4, and this spill mechanism 14
These include a free piston 16 which is a valve body that communicates or blocks communication between the pump chamber 9 and the spill passage IA'i 15, a gear position sensor 17 which is a free piston position detection mechanism that detects the position of the free piston 16, and a free piston 16.
Solenoid valve 18, VC, r, and pulley 11. will be accomplished. The free piston 16 slides within a second cylinder 19 provided in the pump casing 7. 20 is a computer into which engine speed, accelerator opening signal, etc. are input, and the required fuel injection amount is determined according to these signals.
An energizing signal is sent from the converter 20 to the solenoid valve 18 to control its operation. 2] is a first fuel supply passage that communicates the intake passage 102 with the intake passage 11, and has a passage cross-sectional area that can supply sufficient fuel Rk over the entire operating range of the engine. A first fuel stop valve 22 is provided in this communication FA 621. 23 is the first fuel supply passage 21
This is a second fuel supply passage which branches off from the middle and opens into the suction passage 11, and is formed to have a smaller diameter than the first fuel passage 21.

24 is a second fuel stop valve provided in the second fuel supply passage 23. These first and second fuel stop valves 22. '
The opening and closing of 24 is also controlled by the energization signal from the computer 20, and the first fuel stop valve 22 is opened by energizing when the spill mechanism 14 is normal.
It closes without being energized when an abnormality occurs or when the engine is stopped. On the other hand, the second fuel stop valve 24 is not energized when the spill mechanism is normal and when the engine is stopped, and remains closed and active, and is energized and opened only when there is an abnormality. The size of the second fuel supply passage 23 is determined by the engine displacement and fuel injection pump performance, and the size is determined by a real root test so that the engine speed is 2000 to 2500 rpm under no load. It's something to look forward to.

The operation of this embodiment having the configuration as described in Section 2 is as follows.

When the engine speed, accelerator opening signal, etc. are input to the conheater 20, an energization signal is sent from the conbeater 20 to the solenoid valve 18 in response to these signals so that the required intake fuel 1) injection amount is obtained. Then, the solenoid valve 18 opens, and the free piston 16 starts to move completely to the right, and the left end surface 1
61 opens a small hole 191. Here free piston 1
6 moves to the right because the pressure in the pump chamber 9 acts on the left end surface 161 of the free piston 16, and the hydraulic pressure in the right pant 162 that should be repelled by this is transmitted through the solenoid valve 18 to the spill passage 15.
This is because it is open to In this way, the pressure-receiving area of the left end surface 161 of the free piston 16 increases dramatically, and the free piston 16 moves to the right at once, and the gap between its right singing surface 162 and the gear rough 0 assembly 17 becomes zero. Power stops. At this time, the small hole 191 is the spill passage 1.
5, the oil supply from the pump chamber 9 to the injection valve 13 is stopped. The extraction plunger 1 stops moving to the right and immediately reverses to the left, but at this time, the pump chamber 9 is not immediately connected to the suction passage 11 and there is a delay in drying, so the pump chamber 9 The pressure becomes negative and the free piston 16 is sucked to the left and closes the small hole 191 again. In this way, the fuel is fed under pressure to the injection valve 13, and combustion occurs in the engine (not shown), which takes 7'L. Also free piston 1
6 is detected by the Ghiazzo sensor 17, and the signal is input to the computer 20.

The fuel injection device of this embodiment operates as described above. When 18 is open, the large opening h' is free piston 16.
There is no change in the pressure acting on the 0-car @, and the free piston 16
becomes a stationary crossroads, and signals are output to the gear knob sensor 17 frequently. The output of the nozzle sensor 17 and the state of fuel injection at this time are shown in Figure 24-2. If such an abnormality of the spill mechanism 14 occurs, the computer 20
In response to the command from , the power supply to the fuel stop valve 22 of the white 51 is stopped. Therefore, this first fuel stop valve 22 is closed, and sufficient fuel is no longer supplied throughout the entire operating range of the engine. Therefore, engine overrun is prevented. At the same time, the second fuel stop valve 24 is energized, and the second fuel stop valve 24 becomes l;+4, and the second fuel supply passage 23 is brought into conduction with the suction port 1.02. Fuel limited to 1ljlJ is sent to the pump chamber 9,
This is the engine rotation speed at which the vehicle can run on its own.

In the above embodiment, the free piston 16 is connected to the second cylinder 1.
This corresponds to a safety measure in the case where it is glued and fixed to the left side of 9. In this embodiment, when the free piston 16 is locked in the middle of the second cylinder 19 and the pump chamber 9 and the spill passage 15 remain in communication, no dj4<g31 is supplied to the engine. No need,
Although the engine will stop immediately and it is safe, the vehicle will not be able to drive on its own. Another embodiment that eliminates this problem is shown below. FIG. This corresponds to the embodiment shown in FIG. 1, which is further provided with a third fuel stop valve that turns on and off the passage of fuel in the middle of the spill passage.

That is, a third fuel stop valve 25 is installed in the middle of the spill passage 15.
is provided, and when the fuel stop valve 25iIi spill structure 14 is normal and when the engine is stopped 1,'? The computer 20 makes sure that 1ljllη1<1 is set so that the signal is opened only when the system building mechanism 14 is abnormal and the fl is closed.

With such a configuration, the free piston 16
When the second cylinder 19 is locked in the middle and the pump chamber 9 and the spill passage 15 are electrically connected, the first fuel stop valve 22 is de-energized and closed. The fuel stop valve 24 is energized to open it, and at the same time, the third fuel stop valve 25 is also energized to close it.

As a result, the constant pressure chamber (
Fuel no longer flows into the fuel storage section 17, and the plunger 1 can increase the fuel pressure. Therefore, the engine can be operated at a speed that allows the vehicle to run on its own.

Effects of the Invention As described above, the present invention provides a fuel supply system that spills fuel by the movement of the free piston and supplies the engine with fuel separation according to the engine operating condition, in which the position of the free piston is constantly detected. As a result, it is possible to detect a situation in which the amount of fuel supplied to the engine differs from the engine operating state, and if the Schiffly piston remains closed to the spill passage due to a failure of the spill mechanism, the pump chamber The amount of fuel supplied to the pump chamber is automatically suppressed to completely prevent engine overrun, and the fuel supply to the pump chamber can be maintained within the range that allows the engine to run on its own. Practicality can be further increased.Furthermore, when the free piston is locked in the cylinder and the spill passage remains in communication with the pump chamber, this spill passage is automatically closed, thereby preventing the engine from stopping. It has the effect of being able to be avoided.

[Brief explanation of the drawing]

Fig. 1 is a detailed sectional view of an embodiment of the first invention of the present invention, and Fig. 2 is a graph comparing the free piston position detection mechanism and the fuel injection state when the spill mechanism is normal and when it is abnormal. , FIG. 3 is a vertical 1゜ side view of an embodiment showing the second invention of the present invention. 1... Plunger, 1a... First cylinder, 7...
- Pump casing, 71... constant pressure chamber, 9... pump chamber, 10... distribution passage, 102... suction port,
11... Suction passage, 13... I injection valve, 14... Spill tff11''L 1.5... Spill passage, 16
...Free piston, -17...Gap sensor,
18...Solenoid valve, 19...Second cylinder, 20...
・Computer, 21...The first fuel cable is 11.2
2... First fuel stop valve, 23... Second fuel passage, 2
4...Second fuel stop valve, 25...Third fuel stop valve. Figure 2 Normal〕″(′:+,・11′

Claims (1)

[Scope of Claims] 1. A plunger that reciprocates within a first cylinder to change the volume of a 27-g chamber formed within the first cylinder and force-feeds fuel within the pump chamber to the fuel injection valve; a spill passage for circulating the fuel in the pump chamber to the fuel storage section; and a second cylinder formed in the middle of the spill passage, which is slidably installed in the second cylinder, and communicates the spill passage with the pump chamber along the spill passage. A free piston that opens and closes, a solenoid valve that controls opening and closing of the free piston, a free piston position detection mechanism that detects the entire position of the free piston, and each detection of engine rotation speed, accelerator opening, and the free piston position. and a computer to which a signal is input, and the computer causes the free piston to close the spill passage when fuel is supplied to the fuel injection valve, and causes the free piston to close the spill passage when fuel is not supplied to the fuel reservoir. In the fuel supply device H for an internal combustion engine, the electromagnetic valve is controlled so as to open the spill passage. A first fuel passage through which fuel can pass and a second fuel passage through which a small amount of fuel can pass are installed, and the first fuel passage through which a small amount of fuel can pass is provided. a first opening and closing passageway into a second fuel passageway;
A fuel 1q stop valve and a second fuel stop valve are provided respectively, and when the drive signal to the solenoid valve and the free piston position monitoring signal 7 are not detected in synchronization, the first 1. A fuel supply device for an internal combustion engine, characterized in that it is configured to close a fuel stop valve and open a second fuel stop valve. 2. A plunger that reciprocates in the first cylinder to change the volume of a pump chamber formed in the first cylinder and forcefully feeds the fuel in the pump chamber to the fuel injection valve; a spill passage for returning the flow to the storage section; a free piston that is slidably installed in a second cylinder formed in the middle of the spill passage and opens and closes communication between the spill passage and the pump chamber; A solenoid valve that controls the opening and closing of the free piston, a free piston position detection mechanism that detects the position of the free piston, and a computer into which detection signals of the engine rotation speed, accelerator opening, and the free piston position are input. The computer causes the free piston to close the spill passage when fuel is supplied to the fuel injection valve, and causes the free piston to open the spill passage when fuel is returned to the fuel storage section. In the fuel supply device for an internal combustion engine, which controls the electromagnetic valve, a first fuel passage through which a large amount of fuel can pass is provided in the middle of the fuel supply passage from the fuel storage section to the pump chamber. and a second fuel passage through which a small flow of fuel passes, and
Part 1. A first fuel stop valve and a second fuel stop valve that fully open and close the passage are provided in the second fuel passage, and a third fuel stop valve that opens and closes the passage is provided in the middle of the spill passage. , when the displacement signal and the free piston position 16'' detection signal to the electromagnetic valve are not detected in synchronization, the first fuel stop valve is closed, the second fuel stop valve is opened, and the third fuel stop valve is opened. A fuel supply device for an internal combustion engine, characterized in that it is configured to close a fuel stop valve.