JPH0261345A - Load controller for diesel engine - Google Patents

Abstract

PURPOSE:To make improvements in accelerability at the time of reacceleration by making a dashpot function so as to be stopped when an accelerator pedal operating value is in the specified close-position, in a device which makes operation of a control lever have this dashpot function. CONSTITUTION:A control rack 7 of a fuel injection pump 8 is driven by a governor 5, while a control lever of this governor 5 is driven by a pulse motor 4 being controlled by a control unit 6 which has such a function that a revolution command to be given to the pulse motor 4 will not become more than the specified speed, no matter how operating speed of an accelerator pedal 1 is rapid, namely, a dashpot function. In this case, this dashpot function makes an accelerator pedal operating value so as to be stopped when it is at the more close-position than an accelerator pedal position corresponding to engine speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a load control device for a diesel engine that requires rapid load adjustment.

(Prior art) Diesel engines are widely used in vehicles, especially automobiles, due to their superior thermal efficiency and fewer electrical components compared to spark ignition engines, but the inherent characteristics of diesel engines alone are The engine speed during idling is unstable, and there is a risk of a so-called revving phenomenon in which the engine speed increases until it collapses even if the accelerator is not operated in the mid-to-high engine speed range.

Therefore, as an example of a means for compensating for these drawbacks, there is a means for installing an all-speed type governor. This all-speed type governor, regardless of its structure (electronic or mechanical), has the effect of trying to keep the engine speed stable over the entire engine speed range. but,
When the operating state changes from one engine speed to another, and if the speed of change is rapid, the all-speed governor will respond to the new engine speed and keep the engine speed constant. It takes some time for this to occur, and during that time the rotational speed increases and decreases, causing what is called a governor hunting phenomenon in which the rotational speed is not constant. Therefore, when operating the governor control lever to change the engine speed, a function is added to regulate the operating speed of the control lever so that it does not exceed a certain speed. This function is called the dashpot function.

(Problems to be Solved by the Invention) A dashpot function must be added to drive a control lever for controlling the rotation speed of a diesel engine equipped with an all-speed governor.

However, if the driver depresses the accelerator pedal more roughly than the amount of accelerator pedal depression that corresponds to the number of revolutions during engine acceleration, the dashpot function is activated, and even if the driver quickly operates the accelerator pedal, the control lever The movement of the engine does not follow the movement of the accelerator pedal, especially when driving - when re-accelerating by releasing the accelerator pedal and depressing it again, the rate of increase in engine speed is slower than the acceleration expected by the driver, and the agility of the vehicle is affected. This hindered acceleration.

According to the present invention, when the accelerator pedal is operated in the acceleration operation direction from the accelerator pedal depression position corresponding to the engine speed during the acceleration operation, the operation of the dashpot function that suppresses the operating speed of the control rack is stopped. It is an object of the present invention to provide a load control device for a diesel engine that has a dashpot regulating means that makes it difficult to control the load of a diesel engine.

(Means for solving the problem) Considering the original necessity of the dashpot function, it is not necessary to operate it all the time, and there are cases where the governor hunting phenomenon does not occur even if the control lever is operated quickly without the dashpot function being activated. be. Therefore, the present invention has an actuator that transmits the operation of the accelerator pedal to a control lever for adjusting the fuel supply of the engine, and is provided on the actuator to detect the operation of the accelerator pedal operated at a predetermined speed or higher and control the lever. A load control device for a diesel engine having a dashpot means for suppressing the operating speed of a lever to a predetermined value, and a table for storing an engine rotation speed detection means for detecting the engine rotation speed and a specified accelerator pedal position corresponding to the engine rotation speed. , an accelerator pedal depression position detection means for detecting an accelerator pedal depression position, an accelerator pedal depression position amount from the accelerator pedal depression position detection means and an engine rotation speed from the engine rotation speed detection means, and using the table, the accelerator pedal depression position is detected. and means for controlling the dashpot means to stop operating when the pedal depression position is in a light load direction with respect to the accelerator pedal specified position corresponding to the engine speed stored in the table. The object of the present invention is achieved by providing a load control device.

(Function) A signal indicating the current engine speed and a signal indicating the amount of depression of the accelerator pedal is input to the control unit, and first the amount of accelerator depression is compared with the current driving state. Determine which operation is acceleration. If it is a deceleration operation, the control lever is moved in the closing direction at a predetermined speed, and if the current state is to be maintained, the position of the control lever is maintained. If it is an acceleration operation, the amount of accelerator pedal depression corresponding to the input engine rotation speed is determined before the relationship between the engine rotation speed and the accelerator pedal depression amount stored in the control unit. If the actual amount of depression is large, the control lever is moved at the highest speed, and if the amount of actual depression is small, the control lever is moved in the opening direction at a predetermined speed. Once the above series of judgment operations are completed, the above judgment operations are constantly repeated at preset intervals while the vehicle is driving.

(Example) Next, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a functional block diagram of an engine load control device showing an embodiment of the present invention.

Mission 1 transfers engine rotational force to the output side of the diesel engine 10 during a shift change or when idling.
A clutch 11 for insulating the engine 2 and the rest, and a rotation speed detector 3 connected to the rotating shaft of the engine by a method suitable for transmitting the rotation speed of a belt or gear, etc. are installed. The rotation speed detector 3 supplies a rotation speed signal proportional to the rotation of the engine to the control unit 6. The clutch 11 has a transmission 12 for performing a shift change.
Tires 13 are connected via a drive shaft 14, and the rotational force of the engine 10 is transmitted to the road surface to drive the vehicle. Further, the driver controls the engine output by the amount of depression of the accelerator pedal 1, and the amount of depression is converted by the amount of depression detector 2 into a position signal proportional to the amount of depression, and is supplied to the control unit 6. Inside the control unit 6 is a pulse motor 4 for receiving the engine rotational speed signal from the rotational speed detector 3 and the depression amount signal of the accelerator pedal 1 from the depression amount detector 2, and for driving the control lever of the governor 5. an input/output interface circuit 6e for outputting a drive signal to the controller, a ROM 6b for storing in advance the relationship between the rotational speed signal and the depression amount signal and the control lever position of the governor 5, and a control for storing a control program. Under the control of the memory circuit 6d and this control program, the CPU 6a performs calculations based on the rotational speed signal and the depression amount signal from the human output interface circuit 6e, as well as related data stored in the ROM 6b, and temporarily stores the calculation results. It is composed of a RAM 6c for storing information, and a timer circuit 6f as a clock means for arbitrarily setting the counting cycle of the CPU 6a in advance. By the way, since the engine 10 is a diesel engine, its rotational speed is unstable in an idling state, and in the medium and high rotational speed range, the engine speed reaches the upper limit rotational speed or higher even without performing an accelerator operation, causing a so-called revving phenomenon. Motsu.

Therefore, in order to stabilize the engine speed and make it easy to operate as a vehicle engine, an all-speed governor 5 is connected, and the control rack 7 is adjusted to respond to fluctuations in the engine speed, and the plunger pump 8 is controlled. Stabilizes the rotation speed by increasing or decreasing the amount of fuel pumped to the engine.

In addition, when changing the engine rotational output significantly, for example, accelerating or decelerating, the control lever of the governor 5 is operated by rotating the pulse motor 4 connected to the control lever, and the position of the control rack 7 is greatly moved to control the plunger pump. The amount of fuel pumped to the No. 8 engine will be significantly changed. However, if this drastic change in output is performed suddenly, it will take a long time to stabilize the rotation speed of the engine 10 due to the characteristics of the governor 5, and until it stabilizes, the rotation speed of the engine 10 will repeatedly increase and decrease. This causes the governor hunting phenomenon. Therefore, the control lever cannot be operated suddenly by the pulse motor 4, so the rotation speed command issued from the control unit 6 to the pulse motor 4 will not exceed a certain constant speed, no matter how rapid the operation speed of the accelerator pedal 1 is. It must be set as follows. This function that does not allow the speed to exceed a certain level is called a dashpot function, but it is not necessary to operate this dashpot function in all conditions during driving, and the control unit 6 makes a decision whether to turn the dashpot function ON or OFF. The details of the judgment will be explained with reference to FIG.

Figure 2 shows a control unit that commands the rotational speed and rotational direction of the pulse motor 4 for operating the control lever of the governor 6 from the correlation between the amount of depression of the accelerator 1, the engine rotational speed, and the position of the control lever at that time. FIG. 6 is a flow diagram showing the content of the determination in step 6. The flow of judgment within the control unit 6 shown in this figure is defined as one cycle from the start of step 50 to the end of step 61, and while the engine 10 is running, the judgment operation is constantly performed at a preset time period by the timer circuit 6f. Set it to repeat. Assume that the cycle of judgment in the control unit 6 starts when the vehicle is about to be accelerated from a certain running state. First, unconditionally, the engine rotation signal converted by the rotation speed detector 3 and the depression amount signal of the accelerator pedal 1 converted by the depression amount detector 2 are respectively passed through the human output interface circuit 6e in steps 51 and 52. It is taken into the control unit 6.

At this time, the rotation signal is temporarily stored in the RAMac, and the depression amount signal is determined in the next step 53.The position of the control lever corresponding to the depression amount is set in advance from the relationship between the two, and the relationship is stored in the ROM 6b. Obtained from the formula. Let the position of the control lever calculated in step 53 be a, and the actual position of the control lever at that time be b. The actual position of the control lever corresponds to the rotational position of the pulse motor 4 at that time, and the pulse motor 4 is moved by commands from the control unit 6, so the actual control lever position signal etc. are sent to the control unit 6 again. By always storing the rotation command issued to the pulse motor 4 in RAMSc, b can be determined within the control unit 6 even if it is not imported. In the next step 54, the magnitude relationship between a and b is compared; a large position of the control lever indicates that the control lever is on the open side, and a small position indicates that the control lever is on the closed side.
The magnitude relationship of a and b compared in step 54 is as follows:
It can be divided into two cases. First, if a<b, this corresponds to a deceleration operation like releasing the accelerator pedal 1, but in this case, the process jumps to step 55 and the pulse motor 4 is driven so that the control lever closes at a preset speed. A signal is sent from the control unit 6 to the pulse motor 4. Second, when a=b, the current driving state desired by the driver, such as driving at a stable constant speed, is equal to the current driving state, and the vehicle operates to maintain that state. Thirdly, when a>b, that is, when the driver performs an operation equivalent to an acceleration operation, the process jumps to step 57, which has already been obtained in step 51 from the equation of the relationship between the engine speed and the position of the control lever, which is stored in the ROM 6b in advance. The position C of the control lever corresponding to the current engine speed is determined based on the engine speed signal stored in the RAM 6c. Then, in step 58, the actual position of the control lever is compared with C, and if b<c, the process jumps to step 59, and the dashpot function is turned off, that is, the control lever is driven in the opening direction at maximum speed. If so, the process jumps to step 60 and issues a rotation command to the pulse motor 4 through the human output interface 6e so as to turn on the dashpot function, that is, drive the control leno 1- in the opening direction at a preset speed.

Among the judgment steps explained above, step 55.5
When any one of steps 6, 59, and 60 is completed, one cycle of judgment ends, and a series of judgment cycles starts again from the start of step 50 after a time set in advance by the timer circuit 6f.

Although the present invention has been described by way of one embodiment, various modifications can be made within the scope of the gist of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As explained in detail above, according to the present invention, the control rack operates when the accelerator pedal is operated in the acceleration operation direction from the accelerator pedal depression position corresponding to the engine rotational speed during the acceleration operation. By discontinuing the operation of the dashpot function that suppresses speed,
For example, when the accelerator pedal is released while the vehicle is running and the accelerator pedal is depressed for re-acceleration, this has the effect of quickly accelerating the vehicle.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of a load control device for a diesel engine according to an embodiment of the present invention, and FIG. 2 is a flow diagram showing the content of judgments within the co-trawl unit. 1... Accelerator pedal, 2... Accelerator pedal depression position detector, 3... Engine rotation speed detector, 4...
Actuator, 6... Control unit, 6a.
...CPU, 6b RAM, 10...Diesel engine. Patent applicant: Isuzu Motors Co., Ltd. Representative: Patent attorney Minoru Tsuji Figure 2

Claims (1)

[Claims] A load control device for a diesel engine in which a dashpot function is retained in the operation of a control lever, which has means for stopping the dashpot function when the amount of accelerator pedal depression is closer to the closed position than the accelerator pedal position corresponding to the engine rotation speed. A load control device characterized by: