JP3272589B2 - Idling control device for fuel injection pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idling control device for a fuel injection pump, and more particularly to a control system for adjusting the position of a control rack of a fuel injection pump so that the engine speed becomes a preset speed. The present invention relates to an idling control device for a fuel injection pump.

[0002]

2. Description of the Related Art A diesel engine is provided with a fuel injection pump. The fuel pressurized by the fuel injection pump is pressure-fed to a fuel injection nozzle, and the fuel is sprayed into a cylinder by the fuel injection nozzle and injected into a cylinder. The fuel is spontaneously ignited by heat to perform combustion.
The control of the output of the engine is determined by the amount of fuel injected by the fuel injection pump at one time. In order to adjust the injection amount, a control rack is provided in the fuel injection pump, and the control rack changes the effective stroke of the plunger to control the injection amount.

In order to control the position of a control rack of a fuel injection pump, an electronic governor has been used instead of a conventional mechanical mechanical governor.
The electronic governor includes an actuator for moving the control rack, and an electronic control device including a computer for supplying a control signal to the actuator. By using such an electronic governor, more complicated control can be performed.

[0004]

According to the fuel injection pump using the electronic governor, the engine speed can be controlled to a constant speed during idling control. In other words, the engine speed is taken into the electronic control unit, and the control rack is moved by the actuator so that this speed matches the target speed, and the fuel injection amount is adjusted to reduce the engine speed. Feedback control is performed to achieve the target rotation speed. Therefore, the engine speed during idling can be stabilized.

[0005] However, in a vehicle equipped with a diesel engine in which fuel is supplied by a fuel injection pump having such an electronic governor, when the right foot is released from the accelerator pedal and the brake pedal is depressed, the accelerator is released. Since the pedal is returned, the fuel injection pump shifts to idling control. That is, control is performed in which the position of the control rack is adjusted by the actuator so as to reach a preset target rotation speed.

When the water temperature of the engine is low, when the idle adjustment knob is pulled, when the compressor of the air conditioner is driven, and the like, idling control is performed so that the engine speed becomes, for example, 800 rpm. At this time, when the brake pedal is depressed to brake the drive wheels, a load is applied to the engine, and the load tends to reduce the rotation speed of the engine. Then, the idling control of the fuel injection pump causes the control rack to move to the increasing side where the amount of fuel is increased, cancel the load associated with braking, increase the engine torque, and set the rotation speed to the target rotation speed, for example, as described above. 800r
pm is controlled.

[0007] That is, according to the fuel injection pump provided with the electronic governor, even if an attempt is made to stop the vehicle by applying a brake, the electronic governor operates to increase the fuel within an allowable range. When the brake is applied by stepping on the brake, the generated torque of the engine increases and the vehicle feels as if the vehicle is being pushed from behind, and there is a problem that the drivability deteriorates as the target rotation speed of the idling control increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an idling control device for a fuel injection pump which prevents drivability from being deteriorated by idling control during braking. Aim.

[0009]

According to the present invention, there is provided an idling control apparatus for a fuel injection pump, wherein a position of a control rack of the fuel injection pump is adjusted so that the number of rotations of the engine becomes a predetermined number of rotations. An idling control device for a fuel injection pump, which controls the position of a control rack of the fuel injection pump so as not to exceed an idle full rack position when an amount of depression of an accelerator pedal is smaller than a predetermined value. is there.

Therefore, when the brake is depressed by releasing the foot from the accelerator pedal and depressing the brake pedal, idling control is performed so that the position of the control rack of the fuel injection pump does not exceed the idle full rack position. Become.

[0011]

FIG. 1 shows a diesel engine 10 provided with an idling control device for a fuel injection pump according to one embodiment of the present invention. 11 are provided. The fuel injection pump 11 is composed of a Bosch type row pump, and a control rack 12 extending in a lateral direction controls a supply amount of fuel that is pumped at one time. In addition, this fuel injection pump 1
A timer 16 is attached to one camshaft 15, and the timing of injection is adjusted by the timer 16.

In particular, the fuel injection pump 11 includes an electronic governor, and is provided with the control rack 12.
Is used to move the actuator.
The actuator 13 is controlled by an electronic control device 14 including a computer. That is, an electronic governor is constituted by the electronic control device 14 and the actuator 13, and the electronic governor electronically controls the supply amount of fuel injected at one time via the control rack 12.

A flywheel housing 20 is provided on the rear side of the diesel engine 10, and a torque converter 21 is housed inside the flywheel housing 20. A planetary gear type transmission 22 is connected to the rear side of the torque converter 21. An output shaft 23 for transmitting torque to drive wheels protrudes from the rear end of the planetary gear type transmission 22.

The electronic control device 14 of the electronic governor is shown in FIG.
As shown in the figure, an idling control knob 41, a water temperature sensor 42 for detecting the temperature of the engine coolant, a rotation sensor 43 for detecting the number of revolutions of the engine, an accelerator pedal sensor 44 for detecting the amount of depression of an accelerator pedal, a fuel injection pump A rack position sensor 45 for detecting the position of the 11 control rack 12 and a switch 46 of the air conditioner compressor are connected to each other. And, based on the information of these sensors 41 to 46,
The electronic control unit 14 supplies a control signal to the electronic governor, and the actuator 13 moves the control rack 12 in accordance with the control signal to adjust the amount of fuel pumped by the fuel injection pump 11.

FIG. 3 shows the characteristics of the control rack 12 of the fuel injection pump 11 controlled by the electronic control unit 14 and the actuator 13. The position of the control rack 12 is adjusted by the actuator 13 according to the engine speed. I try to control. This control is, in principle, an all-speed control. In addition, here, the maximum position of the control rack 12 at the time of idling control is switched between the normal full rack position and the idle full rack position for control.

FIG. 4 shows such a control rack 12.
2 is a block diagram for controlling the position of the control rack 12, particularly at the time of idling control. The position of the control rack 12 of the fuel injection pump 11 is determined on the drive map according to the accelerator pedal depression amount and the engine speed. This is the control during normal operation.

For such control, an idle rotation control signal is added at an adding element 29. That is, a signal for adjusting the control rack 12 so that the idle rotation control means achieves the target idle rotation is supplied to the addition element 29 in accordance with the water temperature of the engine, the position of the idle adjustment knob, whether the compressor of the air conditioner is operating, and the like. I do. That is, this control is an idle-up control, and when the water temperature of the engine is low, when the idle adjustment knob is pulled, or when the compressor is driven, the rotational speed is changed from the normal 550 rpm to 800 rpm. ing.

Further, the selector element 3 of this control block
Reference numeral 1 designates one of the normal full rack position and the idle full rack position to be input through the switch 30. The selector element 1 controls the position of the control rack 12 so as not to exceed the normal full rack position or the idle full rack position. 31. Therefore, the output of this selector element 31 gives the target control rack position.

The operation of the switch 30 and the selector element 31 of the control block diagram in FIG. 4 is shown in FIG. The computer of the electronic control unit 14 detects the amount of depression of the accelerator pedal via the accelerator pedal sensor 44, and performs normal governor control when the accelerator pedal is depressed. This governor control is based on a drive map.

On the other hand, when the accelerator pedal is not depressed, idle rotation control is performed. Then, it is determined whether the position of the control rack 12 for obtaining the target rotation speed in this case has exceeded the idle rack position shown in FIG. 3, and if it has, the control rack 12 is returned to the idle rack position. I have. As a result, the position of the control rack 12 is moved only to a position equal to or less than the idle full rack position.

Therefore, by such control, for example, when the brake pedal is depressed with the right foot released from the accelerator pedal for braking, the position of the control rack 12 of the fuel injection pump 11 is suppressed to at most the idle full rack position. Therefore, the value is usually suppressed to a value lower than the rack position. Therefore, the fuel injection pump 1
The fuel supply amount is suppressed, and the deterioration of drivability due to an increase in engine torque is prevented.

In particular, in a vehicle provided with a torque converter 21 and a planetary gear type transmission 22 as shown in FIG.
The feeling that the vehicle is pushed from behind disappears. In the case of a mechanical clutch that frictionally engages, it is possible to eliminate the feeling that the vehicle is pushed from behind by disengaging the clutch. However, in a vehicle provided with the torque converter 21,
The output torque of the engine 10 is constantly
Such idling control is extremely effective because the power is transmitted to the drive wheels via the control wheels.

FIG. 6 shows another embodiment. In this embodiment, the presence or absence of depression of an accelerator pedal is detected, and when the accelerator pedal is depressed, normal governor control is performed. I have. On the other hand, when the accelerator pedal is not depressed, it is determined whether or not the idle full rack position has been exceeded, and when the idle full rack position has been exceeded, the rack is controlled within the idle full rack position. .

Next, when the position does not exceed the idle full rack position, the process shifts to idling rotation control, and when the target idle rotational speed is matched, the rack position is maintained. On the other hand, when the rotational speed is higher than the target idle speed, the control rack 12 is returned to the reduced amount side. When the rotation speed is lower than the target rotation speed, the rack is moved to the increased amount within the idle full rack position.

Accordingly, by such control, the control rack can be moved only to the idle full rack position shown in FIG. 3, thereby improving the drivability particularly during the braking operation during idling. .

FIG. 7 shows still another embodiment. Here, the switching of the switch 30 shown in FIG. 4 is provided with hysteresis, and it is determined whether or not the accelerator pedal is depressed by providing hysteresis when the accelerator pedal is depressed and when the accelerator pedal is released. Like that. That is, when the accelerator opening increases, the normal full rack position is set when the accelerator opening is 7% or more, whereas when the accelerator pedal is released, the accelerator opening decreases to 5% or less. In the lowered state, control is switched to the idle full rack position.

Therefore, according to such control, it is possible to prevent hunting from occurring in the control while the accelerator pedal is being returned, and to smoothly switch to the idling control.

[0028]

As described above, the present invention controls the position of the control rack of the fuel injection pump so that it does not exceed the idle full rack position when the depression amount of the accelerator pedal is smaller than a predetermined value. It is.
Therefore, it is possible to reduce the deterioration of drivability in which the vehicle feels as if the vehicle is being pressed from behind when the vehicle is depressed while the accelerator pedal is not depressed, i.e., when the brake pedal is depressed during idling rotation. This makes it possible to improve the control characteristics of the idling control device of the fuel injection pump.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of an engine including a fuel injection pump.

FIG. 2 is a block diagram illustrating a configuration of an electronic governor.

FIG. 3 is a graph showing a change in the position of a control rack with respect to an engine speed.

FIG. 4 is a block diagram illustrating control of the position of a control rack.

FIG. 5 is a flowchart showing a control operation.

FIG. 6 is a flowchart showing a control operation.

FIG. 7 is a flowchart showing a control operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Diesel engine 11 Fuel injection pump 12 Control rack 13 Actuator 14 Electronic control unit 15 Camshaft 16 Timer 20 Flywheel housing 21 Torque converter 22 Planetary gear type transmission 23 Output shaft 29 Addition element 30 Switch 31 Selector element

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) F02D 1/02 321 F02D 1/02 F02D 41/12 380

Claims (1)

(57) [Claims] An idling control device for a fuel injection pump, wherein a position of a control rack of the fuel injection pump is adjusted so that an engine speed becomes a preset speed, the depression amount of an accelerator pedal is predetermined. The idling control device for a fuel injection pump, characterized in that when the value is smaller than the value, the position of the control rack of the fuel injection pump is controlled so as not to exceed the idle full rack position.