JPS58143133A - Control device for fuel injection timing - Google Patents

Abstract

PURPOSE:To make it possible to automatically set the fuel injection timing upon warming-up of an engine, by arranging, in a control device for fuel injection timing, a limiter for setting the fuel injection timing in the vicinity of the maximum spark retardation. CONSTITUTION:During warming-up of an internal-combustion engine 1 upon a cold condition, the viscosity of working oil is extremely high since the temperature of the working oil is low. Under this condition a computer set a selector valve 5 to a selecting position 5B if the temperature of working oil is lower than a predetermined value, and therefore, a piston 4a is moved under the pressure of working oil to its rightmost stroke end in the direction in which the relative rotational phase angle is set to the maximum spark retardation. However, since the pressure of working oil in a pipe line 7b is higher than that in a hydraulic actuator 4 when the temperature of working oil is low, the position of the piston 4a is limited to the position of the piston 6a of a limiter 6 so that the piston 6a is pressed toward its leftmost stroke end, thereby the piston 4a is moved to the predetermined position of spark retardation where the relative rotational phase angle of a drive shaft 2b is set just before the maximum spark retardation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection timing control device used in an internal combustion engine such as an automobile.

When using a fuel injection timing control device for an internal combustion engine, use C in cold weather such as winter;
Ideally, it would be possible to control fuel injection timing with high response performance, but in such cold conditions, it is difficult to control fuel injection pumps.

As a result, conventionally, so-called warming-up occurs when starting such an internal combustion engine.
-up), it is clear that if the fuel injection timing is set to a value close to the most retarded value, warm-up can be performed well. A limiter set near the most retarded angle was attached to the fuel injection timing control device, and a configuration was adopted in which this was switched by a unique switching valve.

An object of the present invention is to provide a fuel injection timing control device that includes a switching valve as described above.

The present invention will be explained based on an embodiment. FIG. 1 shows a system diagram of an embodiment of a fuel injection timing control device according to the present invention.

The internal combustion engine 1 includes a drive shaft 1b, a train train 1a, and an input shaft 2as.
The Q5 tie 7-2 drives the fuel injection pump 3 via the timer 2 and the drive shaft 2b, and converts the relative rotational phase angle between the drive shaft 1b or input shaft 2a and the drive shaft 2b. , which controls the fuel injection timing in the fuel N9 injection pump 3.

The conversion of the relative rotational phase angle in the timer 2 is performed by the hydraulic actuator 4 operating the lever 2C. Alternatively, the hydraulic actuator 4 may directly perform the conversion operation.

In the hydraulic actuator 4, a piston 4a is fitted into a cylinder 4d of the rectangular hydraulic actuator so as to be able to slide in the axial direction, one end of the piston 4a is linked with a lever 20, and the piston 4a When the piston 4a moves to the left in FIG. 1, the fuel injection timing is advanced, and when the piston 4a moves to the left, the fuel injection timing is retarded.

The limiter 6 attached to the hydraulic actuator 4 allows the piston 6a to slide in the axial direction within the cylinder 6d (the two are fitted together, and one end of the piston 6a is exposed inside the cylinder 4d). , port 6at is pipe line 7b
are in communication, and the hydraulic pressure at port 6a is the piston 6a.
The other end f of the spring 6b is configured to act.
forces the piston 6a to the right.

A throttle passage 7a and a switching valve 5 are interposed in the hydraulic line between the hydraulic naft unit 4 and the hydraulic source 7, and a hydraulic line between the hydraulic source 7 and the throttle passage 7a is a pipe. Lenoids 5e and 5f in the switching valve 5, which communicate with the port 6C of the limiter 6 via the path 7b, are controlled by a computer (not shown).

Further, 7d is a relief valve, and 7e is the same reservoir.

To explain the operation of the above configuration f, the internal combustion engine 1 operates (therefore, the drive shaft 1b is connected to the gear train 1a).
, the fuel injection pump 3 is driven via the input shaft 2as timer 2 and the drive shaft 2b, and by this driving, the fuel injection pump 3 supplies fuel to each cylinder of the internal combustion engine 1. Fuel injection timing is set according to operating conditions.

The fuel injection timing is set by controlling the relative rotational phase angle between the input shaft 2a and the drive shaft 2b in the timer 2, and its operation will be described below.

When the switching valve 5 is set to the neutral position 5N1, the hydraulic oil in the hydraulic source 7 is released to the reservoir 7e via the boats 5c and 5d. Since ports a and 5b are closed, the hydraulic actuator 4 is In contrast, the movement of the piston 4a and the lever 2c is fixed by the hydraulic oil, and the relative rotational phase angle of the drive shaft 2b with respect to the input shaft 2a does not change.
When the switching position of the switching valve 5 is set to the 5A position,
Operation 1-□ in the hydraulic source 7: As a result of the load, the operating pressure is increased and pressure oil is sent to the boat 4c via the boat 5C or 5b, and as a result, the piston 4a moves to the left. Then, the relative rotational phase angle of the drive shaft 2b is advanced, and at this time, the discharged oil from the boat 4b is transferred to the reservoir 7e via the boats 5a and 5d.
will be returned to

Conversely, the switching position of the switching valve 5 is changed from the above operation to 58.
When f is set, the piston 4a moves to the right, contrary to the switching position in 5A above, and as a result, the drive shaft 2b
By retarding the relative rotational phase angle with respect to the input shaft 2a, the fuel injection timing in the fuel injection pump 3 is delayed.

Switching position 5A, 5B or 5 in the above-mentioned switching valve 5
The selection and setting of N is performed by the thread/id 5e or 5f, and the operation of the thread/id 5e or 5f is performed by commands from a computer (not shown).

In contrast to the normal operation described above, when operating the internal combustion engine 1, the operation of the internal combustion engine 1 (in the warm-up state in In response to this, the fuel injection timing control device needs to appropriately perform high-response control.

However, especially at low temperatures in cold regions, the internal combustion engine 1
In such a case during warm-up, the above-mentioned relative rotational phase angle is conventionally fixed at a position slightly before the most retarded position required for operation until the warm-up is completed. It is desirable to leave it alone.

The fixed operation will be explained below.As mentioned above, no matter what position the switching valve 5 is in, the flow of hydraulic oil from the hydraulic valve 7 through the throttle channel 7a will continue. Normally, when the temperature of the hydraulic oil is at an appropriate temperature, the flow resistance of the hydraulic oil in the throttle channel (8) is not very large.\However,
During warming-up of the internal combustion engine 1 after starting the internal combustion engine 1, especially in cold weather, the engine compartment becomes <113>M. , hydraulic source 7
The flow resistance through the constricted channel 7& becomes large, and between the boat 5C and the pipe %7b side in the switching valve 5,
This results in a large difference in hydraulic pressure, and the hydraulic pressure acting on the pipe line 7b is sufficiently higher than the hydraulic pressure acting on the hydraulic actuator 4 side.

In such a state, the computer on the other hand is configured to set the switching valve 5 to the switching position 5B when the temperature of the hydraulic oil is below a predetermined value, and as a result, the piston 4a is pressed toward the rightmost end, that is, in the direction in which the relative rotational phase angle is retarded most, by the hydraulic pressure acting on the port 4b side.

However, in response to this pressing force, as mentioned above, at the low temperature, the working oil pressure on the pipe line 7b side is higher than the working oil pressure on the hydraulic actuator 4 side, so the piston 6a is moved to the left via the port 6c. The force pushing the piston 4a to the right is larger than the force pushing the piston 4a to the right, and the position of the piston 4a is
The position of the piston 6a in the limiter 6 is limited, and the piston 6a is pushed to the leftmost end, so that the position where the piston 4a is limited is slightly before the position where the relative rotational phase angle of the drive shaft 2b is the most retarded. is at a predetermined retard position.

Note that the spring 6b in the limiter 6 is a spring with a small spring force for returning the piston 6&, and does not have a reaction force large enough to affect the pressing force of the piston 6a due to the hydraulic pressure from the port 6c side.

For this reason, at low temperatures where fuel injection timing control is slow, even if the fuel injection timing is kept at the predetermined constant level, the fuel injection timing will not be properly controlled during warming up of the internal combustion engine 1. This allows for warming up.

As described above, as the internal combustion engine 1 continues to warm up, the flow resistance in the passage 7a decreases due to the heat released from the internal combustion engine 1 or the heat generated from the work of the hydraulic oil itself, and the flow resistance is reduced toward the hydraulic actuator 4. The difference between the pressure-fed hydraulic pressure and the hydraulic pressure transmitted to the limiter 6 becomes smaller. As a result, the piston 6a is pushed down by the limiter 6c.
The pressing force becomes smaller than the pressing force of the piston 4a, and the ability of the limiter 6 to limit the movement of the piston 4a disappears,
Also, at this time, the computer detects the rise in the temperature of the hydraulic oil, ends the operation of maintaining the switching position of the switching valve 5 at 5B, and starts normal operation.

In the above configuration, the computer detects the temperature of the hydraulic oil by detecting the difference in oil pressure between the pipe line 7b and the port 5c, and when the difference in oil pressure exceeds a predetermined value, the switching valve is closed. 5 may be set and held at the switching position 5B, and the holding may be canceled when the difference becomes equal to or less than a predetermined value.

As is clear from the above description, the fuel injection timing control device of the present invention automatically fixes the relative rotational phase angle of the drive shaft 2b to a position before the most retarded angle when the hydraulic power source 77 is switched. This makes it possible to do seven things.

As a result, the fuel injection timing control device according to the present invention has a simple configuration, has few failures, does not require any circuit for operating the throttle flow g87&, and is inexpensive to manufacture.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing one embodiment of the fuel injection timing control device according to the present invention. The symbols used in the embodiment are as follows. 1: Internal combustion engine 1a: gear train, 1b = drive shaft. 2: Timer 2a: Input axis, 2b: [Moving axis, 2c Nileper. 3: Fuel injection pump 4: Hydraulic actuator 4a: Piston, 4b and 4c: Port, 4d Niji cylinder. 5: Switching valves 5A, 5B and 5N: Switching position. 5a, 5b, '5c and 5d: port, 5e and 5f: rhenoid. 6: Limiter 6a: Piston, 6b Nispring, 6C: Boat. 7: Hydraulic source 7a: Throttle flow path, 7b and 7C: Pipe line, Fud:
Relief valve, 7e: Lizer/(. Patent applicant: Sanwa Seiki Co., Ltd. Representative: Etsushi Nishikai Figure 1

Claims (1)

[Claims] 1. A drive shaft (2b) that drives the fuel injection pump (3), and a drive shaft (1b) of the internal combustion engine (1) that drives the drive shaft.
) The hydraulic actuator (4) is configured to advance the relative rotational phase angle in one operation and retard the relative rotational phase angle in the other operation. None, the hydraulic actuator is operated by hydraulic pressure from a hydraulic source (7), and a switching valve (5) controlled by a computer is provided in the pipeline between the hydraulic actuator and the hydraulic source. and the computer is configured to hold the switching valve in a direction in which the hydraulic actuator shifts to the retarded side when the hydraulic oil from the hydraulic source is at a predetermined oil temperature or lower, A conduit between the hydraulic power source and the switching valve includes a throttle flow path (
7a), and a limiter (6) for limiting the actuation movement to a predetermined position is attached to the retard side of the hydraulic actuator, and the limiter is configured to connect the hydraulic pressure source and the throttle flow path. 2. A fuel injection timing control device, characterized in that the predetermined position is limited depending on the hydraulic pressure of a conduit between the fuel injection timing control device and the fuel injection timing control device. 2. The fuel injection timing control device according to claim 1, wherein the predetermined position is provided before the position where the relative rotational phase angle is most retarded. 3. The configuration of the hydraulic actuator is a direct-acting piston (
4a) are fitted to be slidable in the axial direction within the cylinder, and the limiters (6) to (6) have a structure in which another piston (6a) is fitted in another cylinder (6d), and the other piston (6a) The hydraulic actuator C'-
The patent is configured such that the other end of the other piston in the axial direction is exposed in the cylinder of the other piston, and the working oil pressure between the oil pressure source (7) and the throttle flow path (7a) acts on the other end of the other piston in the axial direction. A fuel injection timing control device according to claim 1 or 2.