JPH0519019B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply control device, and more particularly to a fuel supply control device that sequentially supplies fuel to each cylinder of an engine by a fuel injection pump, and controls the supply of fuel by a mechanical device attached to the fuel injection pump. The present invention relates to a fuel supply control device controlled by a governor.

A diesel engine is equipped with a fuel injection pump, and the fuel injection pump injects fuel into each cylinder of the engine to supply fuel. This fuel supply is controlled by a mechanical governor attached to the fuel injection pump. The highest and lowest mechanical governors installed in ordinary large vehicles operate to supply fuel according to a set value given by a load lever. Therefore, it has not been possible for a vehicle equipped with a diesel engine to run economically or at a constant speed using such a conventional mechanical governor.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a fuel supply control device that enables economy running and constant speed running.

The present invention will be described below with reference to an illustrated embodiment. FIG. 1 shows a diesel engine 1 equipped with a fuel supply control device according to the present embodiment, and a fuel injection pump 2 is installed on the side of the engine 1. It is provided. The fuel injection pump 2 is driven by the rotation of the engine via a gear 3, a timer 4, and a camshaft 5. That is, the injection pump 2 is provided with the same number of pump units 6 as the number of cylinders of the engine, and each plunger of these pump units 6 is sequentially driven by a cam fixed to the camshaft 5. It's summery. Each pump unit 6 is connected to a corresponding cylinder by a fuel supply pipe 7, through which fuel is supplied to the engine 1. The fuel injection pump 2 is provided with a control rack 8, which controls the amount of fuel supplied by each pump unit 6 at one time. The control rack 8 is controlled by a mechanical governor 9 attached to the fuel injection pump 2. A load lever 10 is rotatably provided on the side of the mechanical governor 9, and this lever 10 is connected to an accelerator pedal 12 via a wire cable 11.
is connected to. Therefore, the amount of rotation of the accelerator pedal 12 is transmitted to the load lever 10 via the wire cable 11, and this load lever 10 is further transmitted to the load lever 10 via the wire cable 11.
The amount of rotation is transmitted to the control rack 8 via the mechanical governor 9, and the control rack 8 controls the amount of fuel supplied.

An air actuator 13 is also attached to the mechanical governor 9, and the air actuator 13 is connected to an air tank 14 via a solenoid valve 15. Also, the air actuator 13
Exhaust of air from the tank is carried out by a solenoid valve 16. Furthermore, the above air tank 1
4 is connected to an air actuator 18 via a solenoid valve 17. When the air actuator 18 is pushed out, the load lever 10
is designed to rotate to the maximum rotation position.
Each of the electromagnetic valves 15, 16, and 17 is controlled by a control signal from a microcomputer 19, respectively. The microcomputer 19 includes a rotation detection sensor 20 for detecting the engine rotation speed, a temperature sensor 21 for detecting the temperature of engine oil, a temperature sensor 22 for detecting the temperature of the engine cooling water, and a temperature sensor 22 for detecting the position of the control rack 8. The detection outputs of a position detection sensor 23 that detects the position of the rod of the air actuator 13 and a position detection sensor 24 that detects the position of the rod of the air actuator 13 are supplied. In addition to this, various information is also supplied to the microcomputer 19, such as the gear ratio of the transmission, the traveling speed of the vehicle, whether or not the brakes are activated, and the outside temperature.

Next, the structure of the air actuator 13 will be explained. The air actuator 13 is equipped with a diaphragm 25, and a return spring 26 is interposed in a chamber below the diaphragm 25. Therefore, the diaphragm 25 is always pushed upward. A rod 27 is fixed to the diaphragm 25, and the lower end of the rod 27 protrudes outside the casing of the air actuator 13, and a pin 28 is implanted therein.
A stop lever 29, one end of which can come into contact with this pin 28, is rotatably supported by the casing of the mechanical governor 9 via a pin 30. By placing the tip of the stop lever 29 within the locus of movement of the protrusion 31 provided on the control rack 8, the tip of the stop lever 29 is brought into contact with the protrusion 31, thereby increasing the maximum stroke of the control rack 8 in the fuel increasing direction. I'm trying to limit it. In addition, the control rack 8 is connected to the rod 32.
It is connected via a sleeve 33 to a floating lever 34 that constitutes the output end of the mechanical governor 9. The protrusion 35 formed on the rod 32 engages with a slit-like elongated hole 36 formed on the sleeve 33, and there is a gap between the two in the relative axial direction along the stroke direction of the control rack 8. Exercise is now possible.
A compression coil spring 37 is interposed in the sleeve 33, and this spring 37 causes the rod 32 to
is forced to move toward the left (in the direction of increase in fuel).

In the above configuration, the solenoid valve 15 is opened by a control signal from the microcomputer 19, and the air actuator 13 is opened from the air tank 14.
When air is supplied inside, the diaphragm 25 shown in FIG. 2 moves downward against the return spring 26, and along with this, the rod 27 also moves downward. Therefore, if the rod 27 is moved sufficiently downward, the stop lever 29 can be rotated to the position shown by the dashed line in FIG. 2 without interfering with the movement of the control rack 8. In such a state, the projection 3 of the rod 32 is compressed by the action of the compression coil spring 37.
5 is located on the left end side of the elongated hole 36 of the sleeve 33, and in this state the relative position between the rod 32 and the sleeve 33 is maintained constant. That is, in this case, the rod 32 and floating lever 34 operate in the same way as if they were directly connected. Therefore, when the accelerator pedal 12 is depressed and the load lever 10 is rotated by the wire cable 11, the rotation of the load lever 10 is transmitted to the control rack 8 via the mechanical governor 9.
Fuel supply is controlled in the same manner as a conventional mechanical governor.

Next, the operation of economy traveling using this engine will be described. Based on instructions from the microcomputer 19, the solenoid valve 16 is opened and the air in the air actuator 13 is discharged through the solenoid valve 16. Then diaphragm 2
5 is pushed by the return spring 26 and will move upwards in FIG. As the diaphragm 25 moves upward, the rod 27 also moves upward, and as a result, the stop lever 29, whose rotation is restricted by the pin 28 of the rod 27, is indicated by, for example, a solid line in FIG. It will rotate to the position shown. By adjusting the amount of air in the air actuator 13 so that the rod 27 is at a predetermined position in this way, the movement stroke of the rack 8 to the left is regulated by the stop lever 29. As a result, the rack 8 cannot be moved to its maximum travel stroke.

Therefore, as shown by the chain line in FIG. 3, the ratio of the fuel supply amount to the engine rotational speed is suppressed to a value lower than the maximum supply amount shown by the solid line in the same figure. Then, the microcomputer 19 controls the solenoid valves 15 and 16, and the air actuator 13 controls the rod 27.
By moving the position further back, the amount of fuel supplied can be further reduced as shown by the dotted line in FIG. Therefore, by using this air actuator 13 and the stop lever 29 driven by the air actuator 13 to regulate the maximum travel stroke of the rack 8, economy traveling can be achieved, reducing fuel consumption. It becomes possible to do so. Furthermore, when the maximum stroke of the rack 8 is regulated using the air actuator 13 in this way, the output torque of the engine relative to the engine speed changes from the solid line to the chain line as shown in FIG. , it will further change to the state shown by the dotted line. Note that Fig. 3 and Fig. 4 correspond, and when the fuel supply amount is shown by the chain line in Fig. 3, the output torque as shown by the chain line in Fig. 4 is obtained, and If the feed rate is reduced as shown by the dotted line in FIG. 3, the engine torque will be as shown by the dotted line in FIG.

In addition, in the case of the above-mentioned economy running, even if the floating lever 34 of the governor 9 shown in FIG. This will be absorbed by the relative movement between sleeve 33 and rod 32. That is, as the compression coil spring 37 contracts and the rod 32 is inserted relatively into the sleeve 33, rotation of the floating lever 34 exceeding a predetermined amount is absorbed.

Next, when the engine is used to drive at a constant speed, the microcomputer 19 first opens the solenoid valve 17 and supplies compressed air from the air tank 14 to the air actuator 18 through the solenoid valve 17. Then this air actuator 18
The piston rod is pushed out and the accelerator pedal 1
2, the load lever 10 is in the direction of increasing fuel regardless of the amount of depression of the pin 38 in FIG.
It will be rotated counterclockwise around the center to the maximum rotation position. Therefore, the rotation of the load lever 10 is transmitted to the sleeve 33 via the floating lever 34 of the governor 9, and the compression coil spring 3
7 causes the rod 32 to be pushed. In other words, the control rack 8 is pushed in the direction of increasing fuel. Therefore, in this state, the air actuator 13 is controlled by the microcomputer 19 via the solenoid valves 15 and 16, and the control rack 8 is moved to the left in FIG. 2 by the rod 27 and the stop lever 29. By arbitrarily regulating it, it becomes possible to control the amount of fuel supplied. Therefore, by controlling the control rack 8 with high precision based on control signals from the microcomputer 19 into which information such as engine speed and vehicle running speed is input, it is possible to drive the vehicle at a constant speed. In this case as well, the relative movement between the rod 32 and the floating lever 34 is absorbed by the relative movement between the sleeve 33 and the rod 32.
At this time, the compression coil spring 37 is only deformed. Therefore, air actuators 13, 18 and a stop lever 29 are added to the conventional mechanical governor 9.
are provided, and by regulating the amount of movement of the control rack 8, the vehicle can run at a constant speed.

In addition, when regulating the maximum stroke of the control rack 8 in the direction of fuel increase for economy driving or constant speed driving, the stop lever 29 whose tip faces the movement locus of the control rack 8 (protrusion 31) is moved by air. The actuator 13 performs swing control. Therefore, even when the air actuator 13 is configured with a diaphragm or the like that makes delicate position control difficult, by appropriately setting the lever ratio of the stop lever 29, the accuracy of controlling the stroke of the control rack 8 can be practically impeded. It can be increased to the extent that it is not.

Furthermore, the compression coil spring 37 deforms to permit relative movement between the control rack 8 and the floating lever 34. Therefore, while the load lever 10 of the mechanical governor 9 of the highest and lowest type is rotated and held at the maximum rotation position by the air actuator 18, the stop lever 2 is moved by the air actuator 13.
Since the stroke of the control rack 8 can be changed arbitrarily by controlling the swing of the control rack 9, the air actuator 18 that rotates and holds the load lever 10 at the maximum rotation position is configured with a simple actuator of the so-called on-off type. The vehicle can be driven economically or at a constant speed while using a mechanical governor of the highest and lowest type, which is simple in construction and highly reliable.

As is clear from the above description, according to the present invention,
By simply attaching a simple air actuator to the highest and lowest type mechanical governor, which is simple and highly reliable, the vehicle can be driven economically or at a constant speed with a precision that does not pose a problem in practical use. Furthermore, the floating lever, which is the output end of the mechanical governor that controls the fuel injection amount in response to the engine speed, the depression state of the accelerator pedal, etc., and the control rack of the fuel injection pump are moved in the stroke direction of the control rack. After connecting the control rack so as to be relatively movable along the floating lever, a spring is used to urge the control rack to move in the direction of increasing fuel with respect to the floating lever, and an actuator is used against the spring to move the control rack in the direction of increasing fuel. Since the maximum stroke of the floating lever is regulated to control the amount of fuel supplied, the relative movement between the floating lever and the control rack can be absorbed using the deflection (deformation) of the spring. Therefore, even when controlled by the actuator, no excessive force is applied to the mechanical governor, and there is no need to protect the mechanical governor using a complicated clutch mechanism, so the configuration of this type of control device is simplified. Ru.

[Brief explanation of the drawing]

FIG. 1 is a front view of a diesel engine equipped with a fuel supply control device according to an embodiment of the present invention, and FIG.
The figure is a cutaway front view of the main part of the mechanical governor installed in this engine, Figure 3 is a graph showing the change in fuel supply amount with respect to the engine rotation speed when economical driving is performed with this engine, and Figure 4 The figure is a graph showing changes in engine torque with respect to the engine speed. In addition, in the symbols used in the drawings, 1... Diesel engine, 2... Fuel injection pump, 8... Control rack, 9... Mechanical governor, 1
3... Air actuator, 15... Solenoid valve, 1
6... Solenoid valve, 19... Microcomputer,
It is.

Claims (1)

[Claims] 1. In a device in which a control rack of a fuel injection pump provided in an engine is controlled by a mechanical governor of the highest and lowest type attached to the pump, a floating lever of the mechanical governor and a control rack of the fuel injection pump are connected to each other. means for connecting the control rack relatively movably along the stroke direction; and means interposed between the floating lever and the control rack to move the control rack relative to the floating lever in the fuel increasing direction. a spring that urges the control rack; a stop lever having its tip facing within the stroke locus of the control rack; and a swinging operation of the stop lever along the stroke direction of the control rack to increase the maximum stroke of the control rack in the fuel increasing direction. An air actuator that performs variable control, an air actuator that rotates and holds the load lever of the mechanical governor at a maximum rotation position regardless of the amount of depression of the accelerator pedal, and air supply to both of the air actuators. A fuel supply control device comprising: an electronic control device that controls the fuel supply control device;