JPH03275960A - Control device for engine speed of working vehicle - Google Patents

Abstract

PURPOSE:To enhance workability of a working vehicle and a feeling in driving the vehicle by preferring the control by which engine output is greater during simultaneous operation of a hand accelerator lever and a foot accelerator pedal. CONSTITUTION:A control device for the engine speed of a working vehicle comprises a control portion 1, a hand accelerator lever 2, a foot accelerator pedal 8, an engine 5, and a fuel injection device 7 and when the hand accelerator lever 2 and the foot accelerator pedal 8 are operated simultaneously a signal THETAo i.e., the output of a proportional plus integral plus derivative operating circuit 4 is compared to a voltage signal THETAg i.e., the output of a proportional plus derivative operating circuit 9 and the control signal by which the drive signal of an actuator 7a input to a pulse width modulation converter circuit 6 is greater i.e., the output of the engine 5 is greater with increased injection quantity is preferred. Thus control shift can easily and smoothly be carried out even when the foot accelerator pedal is operated for acceleration for a short period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention mainly relates to an engine rotation control device (governor device) used in an engine-equipped agricultural vehicle such as an agricultural tractor or combine harvester.

(Prior art) Conventionally, as this type of device, for example, Japanese Patent Application Laid-Open No. 51-1
As shown in Publication No. 04145, using a working device "(
For work driving 1 Samurai, it exerts a speed regulating function in all rotation ranges to perform the desired constant speed driving or constant speed drive of the work equipment, and also adjusts the accelerator when driving on the road to and from the work site or on the road for transportation. In some cases, both control patterns are selected and switched for the purpose of instantaneous and smooth acceleration/deceleration, and in others, as shown in Japanese Patent Laid-Open No. 61-106932, both control patterns are switched between both accelerator adjustment tools. There are those that can be switched depending on the adjustment condition, and JP-A-61-1.1.
As shown in Japanese Patent No. 2746, a system is known in which both of the control patterns are switched according to the traveling speed of the vehicle body.

(Problem to be Solved by the Invention) In the conventional technology, the switching timing between the control pattern during work driving and the control pattern during road driving is controlled manually or depending on the driving speed. Because the switching is forced, it is difficult for the engine to smoothly set the fuel injection control so that the engine can extract its power more effectively.

The present invention has been made in view of the problems of the conventional technology, and its purpose is to provide a constant rotation speed for the hand accelerator lever, which is mainly used for speed setting during work traveling. Constant load control is performed on the foot accelerator pedal, which is mainly used to adjust travel speed when driving on the road, and when the hand accelerator lever and foot accelerator pedal are operated at the same time, the engine output is controlled to be larger. It is an object of the present invention to provide an engine rotation control device for a work vehicle that can improve work efficiency and drive feeling by giving priority to the following.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides an accelerator regulator consisting of a hand accelerator lever that can be held at any operating position and a foot accelerator pedal that automatically returns to the low speed side. In the engine rotation control device for a work vehicle, the hand accelerator lever operates the engine fuel injection device for controlling the injection amount by driving an actuator for adjusting the fuel injection amount via a control unit. The foot accelerator pedal drives the actuator so as to have a speed-torque characteristic with a large fluctuation rate, and the foot accelerator pedal drives the actuator so as to have a speed-torque characteristic with a small torque fluctuation rate with respect to engine speed fluctuations, and the hand accelerator lever and the foot accelerator pedal For simultaneous operation with the accelerator pedal, among the output signals of the control system constituting the control section, the output signal of the control system that increases the engine output is set as a priority signal to drive the actuator.

In addition, there is an upper limit regulation circuit that regulates the upper limit value of the priority signal, and when the engine speed exceeds a predetermined value, outputs a signal that indicates that the actuator position is moving toward the fuel increase side compared to the actual position. It is preferable that an overrun limiter circuit for controlling the position of the actuator is provided in the control circuit section.

(Function) When operating the accelerator using the hand accelerator lever, a constant rotation speed of 11 Jl is performed, and when operating the accelerator using the foot accelerator pedal, constant load control is performed.

When the hand accelerator lever and the foot accelerator pedal are operated simultaneously, the engine output is controlled to be stronger.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is an overall system configuration diagram of an engine rotation control device for a work vehicle according to the present invention.

The engine rotation control device for a work vehicle includes a control section 1, a hand accelerator lever 2, a foot accelerator pedal 8, an engine 5, and a fuel injection device 7.

The control unit 1 proportionally converts the voltage signal es corresponding to the target rotation speed set by the hand accelerator lever 2 via the superimposition circuit 3.
A voltage signal eI+ corresponding to the actual rotational speed of the engine 5 is applied to one input terminal of an integral/differential calculation circuit (hereinafter referred to as a PID circuit) 4, and a voltage signal eI+ corresponding to the actual rotation speed of the engine 5 is applied to the other input terminal, so that both voltage signals ef and An output voltage e0 is generated by performing proportional, integral, and differential calculations on the differential voltage of en, and drives the solemade actuator 7a of the fuel injection device 7 via a PWM (pulse width modulation) conversion circuit 6 to adjust the fuel injection amount. is configured to increase or decrease the number of revolutions of the engine 5, and further,
Voltage signal e corresponding to the amount of depression of the foot accelerator pedal 8
f and a voltage signal e corresponding to the position of the actuator 7a,
The output voltage e1 is obtained by applying the voltage signal e, 1 corresponding to the actual rotation speed of the engine 5 to the input terminal and performing proportional and differential calculations.
Proportional/differential calculation circuit (hereinafter referred to as PD circuit) that generates
9 to control the fuel injection amount.

Further, the output e1 of the upper limit position setter 10 of the actuator 7a and the voltage signal e corresponding to the position of the actuator 7a
1, and an upper limit regulation circuit 11 that regulates the upper limit of the maximum position of the actuator 78, and when the rotation speed of the engine 5 exceeds a predetermined value, the position of the actuator 7a is operated toward the fuel increase side compared to the actual position. The overrun limiter circuit 17 outputs a signal such as , and controls the position of the actuator 7a.

The rotation speed detector 12 outputs a pulse signal Pn with a period proportional to the rotation speed of the engine 5. is the pulse signal p in the frequency/voltage conversion circuit (F/V conversion circuit) 13. is converted into an analog voltage eI+ corresponding to the period of .

The position of the solenoid actuator 7a is detected by an actuator position detector 14, and the position detection output is converted into a DC signal e by a detection/rectification circuit 15.

is converted to The DC signal e is amplified by the amplifier circuit 16, and its output is input to the superimposition circuit 3.

FIG. 2 is a structural diagram showing an example of the configuration of a solenoid actuator and an actuator position detector.

Fig. 2 shows an example of driving the control rack 7b of the fuel injection device 7 for a diesel engine, in which one end of the solenoid type actuator 7a fixed to the side of the fuel injection device 7 is connected to the control rack 7b. Furthermore, a position detector 14 using a differential transformer is provided on the side of the solenoid actuator 7a.

The solenoid actuator 7a uses electromagnetic force to move the actuator 7d in the axial direction according to the amount of current applied to the solenoid 7c. The position detector 14 is a linear displacement detector in which a movable core 14e is inserted into a primary coil 14b and secondary coils 14c and 14d. This detector 14 is activated by exciting the primary coil 14b with low frequency alternating current to activate the movable core 14 connected to the actuator 7d.
Depending on the position of e, the secondary coil 14c is connected with reverse polarity,
The position of the actuator is detected by utilizing changes in the voltage and polarity generated at 14d.

Returning to FIG. 1, the explanation will continue.

The detection/rectification circuit 15 is configured based on the output of the position detector 14 so that when the actuator position detector 14 is located closer to the fuel injection device, the position detection output voltage e becomes higher. The output e of the detection/rectification circuit 15 is the amplifier circuit 1
6 performs DC amplification, and its output is input to the superimposition circuit 3.

In the superimposition circuit 3, as shown in FIG. 3, the output DC amplified by the amplifier circuit 16 is differentiated into a voltage corresponding to a change in the actuator position through a differentiator circuit consisting of a capacitor 3a and a resistor 3c, and then input to an inverting input of an operational amplifier 3d. It is input to terminal 3b. The output voltage e of the hunt accelerator lever 2 is applied to the non-inverting input terminal 3e of the operational amplifier 3d. When no differential input voltage is applied to the inverting input terminal 3b, the output voltage of the superimposition circuit 3 is the same as the voltage of el,
When the actuator position moves to the fuel increasing side, the output voltage of the superimposing circuit 3 becomes the voltage e, which is lower than the voltage e, due to the input from the differentiating circuits 3a and 3c, and when the actuator position moves to the fuel decreasing side, the voltage e, It is configured to have a higher voltage.

FIG. 4 is a circuit diagram showing the foot accelerator pedal 8 and the PD circuit 9. The PD circuit 9 includes an operational amplifier 9a, and a resistor 20 connected between the output terminal 9b and the inverting input terminal 90 of the operational amplifier 9a. Furthermore, it includes human resistors 21 and 22 each having one end connected to the inverting input terminal 9c, and a differentiating circuit 23 connected in parallel with the input resistor 22. The differentiating circuit 23 is a device composed of a capacitor 23a and a resistor 23b,
The output voltage ef of the foot accelerator pedal 8 is input to the non-inverting input terminal 9d. Note that 24 is a backflow prevention diode for outputting an output voltage e only in the direction in which the control rack 7b is opened, and 24a is a current limiting resistor.

Therefore, when the voltage signal e corresponding to the amount of depression of the foot accelerator pedal 8 is larger than the voltage signal en corresponding to the actual rotation speed of the engine 5 and the voltage signal e corresponding to the position of the actuator 7a, the rotation speed The position of the actuator 7a is proportionally corrected, and the position of the actuator 7a is calculated proportionally and differentially (
PD) The corrected voltage signal e1 is output from the PD circuit 9.

FIG. 5 is a circuit diagram when the actuator upper limit position setter 1° and the upper limit regulating circuit 11 are constructed from PID circuits. As shown in FIG. 5, the upper limit regulating circuit 11 includes an operational amplifier 11a, an integrating circuit 25 provided between the output terminal 11b of the operational amplifier 11a, and an inverting input terminal 11c, and one end connected to the inverting input terminal 11c. The input resistor 26 has an input resistor 26, and a differentiator circuit 27 connected in parallel with the input resistor 26. The integrating circuit 25 is composed of three elements including a capacitor 25a, a series circuit of a capacitor 25b connected in parallel to the capacitor 25a, and a resistor 25c. !
! The branch circuit 27 is composed of a capacitor 27a and a resistor 27b.

In addition, the power supply +V is connected to the non-inverting input terminal lie through a resistor 10.
A voltage signal e1 corresponding to the upper limit position of the actuator 7a divided by voltages a and 10b is applied, and a voltage signal e1 corresponding to the position of the actuator 7a is applied to the terminal 11d via the amplifier circuit 16. Note that 30 is a diode for preventing backflow.

Therefore, the upper limit regulation circuit 11 outputs a negative voltage to the output terminal jlb only when the voltage signal e applied via the amplifier circuit is larger than the voltage signal e1.

FIG. 6 shows a circuit in which the overrun limiter circuit 17 is composed of a comparison amplifier circuit. The overrun limiter circuit 17 includes an operational term m unit 17a, a resistor 17d connected between the output terminal 17b of the operational amplifier 17a, and an inverting input terminal 17c, and a power supply +V connected to the inverting input terminal 17c by a resistor 17e,
A voltage signal e corresponding to a predetermined rotational speed of the engine 5 divided by voltage signal 17f is applied, and a voltage signal en corresponding to the actual rotational speed of the engine 5, which is compared with the voltage signal e, is applied to the non-inverting input terminal 17g. Applied and configured. Note that 31 is a diode for preventing backflow.

Therefore, the voltage signal e. The overrun limiter circuit 17 outputs a positive saturation voltage only when the voltage signal e is higher than the voltage signal e. That is, when the actual rotation speed of the engine 5 becomes higher than the predetermined rotation speed.

The operation of the engine rotation control device for a work vehicle configured as described above will be described below.

Speed setting during work driving is mainly done using the hand accelerator lever.
2, a closed loop fsJ control system consisting of a PID circuit 4, a PWM conversion circuit 6, a fuel injection device 7, an engine 5, a rotation speed detector 12, and an F/V conversion circuit 13, and a PrD circuit 4.
, PWM conversion circuit 6, fuel injection device 7, actuator position detector 14, detection/rectification circuit 15, amplifier circuit 16,
Constant rotation speed control as shown in FIG. 7A is performed mainly using a closed loop control system consisting of the superimposing circuit 3. In this case, the hand accelerator lever 2 is used to set the engine output rotation speed to a constant rotation speed such as N1.

On the other hand, the traveling speed adjustment when driving on the road is mainly performed by the foot accelerator pedal 8, and the PD circuit 9 and the PWM conversion circuit 6.
, fuel injection device 7, engine 5, rotation speed detector 12, F
/V conversion circuit 13, PD circuit 9, PWM conversion circuit 6, fuel injection device 7, actuator position detector 14, detection/rectification circuit 15, amplifier circuit 1
Fig. 7B mainly consists of a closed-loop control system consisting of 6 and 6.
Constant load control is performed as shown in the figure. In addition, AI~
A6 shows the engine rotation speed-shaft output characteristic due to the difference in the amount of depression of the foot accelerator pedal 8, and the PD circuit performs a proportional correction for the rotation speed of the engine 5 and a PD correction for the position of the actuator 7a. 9, a characteristic curve as shown in FIG. 7B is obtained.

Further, when the hand accelerator lever 2 and the foot accelerator pedal 8 are operated simultaneously, the signal e0 which is the output of the circuit 4 is compared with the voltage signal e1 which is the output of the PD circuit 9 from P, and the PWM conversion circuit Priority is given to the control signal that has a larger drive signal for the actuator 7a input to the actuator 6, that is, the control signal that increases the fuel injection amount and increases the output of the engine 5. In the case shown in Fig. 7C, the hand accelerator lever
2 shows a state in which the engine speed is set to N1 and the amount of depression of the foot accelerator pedal 8 at the time of parenthesis is A2, and L is shown as an example of a load point.
When the shaft output is greater than the point L, priority is given to constant rotation speed control using the rotation speed N1, and when the shaft output is smaller than the L point, constant load control using the depression amount A2 is given priority.

Therefore, for example, if you want to temporarily increase the rotation speed during constant rotation speed control at the rotation speed N1, press the foot accelerator pedal 8 greatly and raise the L point (not shown in FIG. 7C), and the L point will reach the highest point. From the moment the pedal is pressed, it switches to constant load control at that amount of depression, and the rotational speed can be smoothly increased. Similarly, deceleration from the increased speed state to the constant rotation speed state can be smoothly switched by reducing the amount of depression.

Also, the position of the actuator 7a is set to the upper limit position setter 10.
If it exceeds the upper limit position indicating the maximum fuel injection position set in As shown in FIG. 7, fuel injection is performed to increase the rotational speed of the engine 5 above the upper limit set rotational speed, by sucking in the signal corresponding to the amount of the engine 5 and regulating it so that it is not input to the PWM conversion circuit 6 as it is. I try not to.

Furthermore, a voltage signal e,1 corresponding to the actual rotation speed of the engine 5 is
When the voltage signal e corresponding to the predetermined rotation speed is set as the upper limit, the overrun limiter circuit 1
7 outputs a positive saturation voltage, and the amplifier circuit 1 converts this signal into a voltage signal e1 corresponding to the actual position of the actuator 7a.
6, the PID circuit 4, PD circuit 9, and upper limit regulation circuit 11 generate a pseudo signal that indicates that the actuator 7a is located on the fuel injection increase side compared to the actual position.
The engine 5 is controlled so that it does not overspeed by manually controlling all the control systems.

(Effects of the Invention) As explained above, according to the present invention, for example, even when the foot accelerator pedal is pressed during work driving and the speed is increased for a short time, the control that increases the engine output takes priority. Therefore, it is possible to easily and smoothly switch between control using the hand accelerator lever and control using the foot accelerator pedal, improving work efficiency and driving feeling.

[Brief explanation of drawings]

'tSi diagram is an overall system configuration diagram of the engine rotation control device for a working vehicle according to the present invention, FIG. 2 is a structural diagram showing an example of the configuration of a solenoid actuator and an actuator position detector, and FIG. 3 is a diagram showing a superimposed circuit. Circuit diagram, Figure 4 is a circuit diagram showing the foot accelerator pedal and PD circuit, Figure 5 is a circuit diagram showing the foot accelerator pedal and PD circuit.
FIG. 6 is a circuit diagram showing an actuator upper limit position setting device and an upper limit regulation circuit, FIG. 6 is a circuit diagram showing an overrun limiter circuit, and FIG. 7 is a speed-output characteristic diagram. 1...Control unit, 2...Hunt accelerator lever 5...
-Engine, 7...Fuel injection device, 8...Foot accelerator pedal, 11...Upper limit regulation circuit, 17...Overrun limiter circuit. Patent applicant: Honda Motor Co., Ltd. Agent
Person Patent attorney 2 1) Part time Patent attorney Kuni Ohashi Patent attorney Yu Koyama Figure 2 Idling setting ↓ ↓ Figure 7

Claims (2)

[Claims] (1) The accelerator regulator, which consists of a hand accelerator lever that can be held at any operating position and a foot accelerator pedal that automatically returns to the low speed side, controls the fuel injection amount of the engine by controlling the amount of fuel injected through the control unit. In an engine rotation control device for a work vehicle that is operated by driving an actuator for adjusting an injection amount, the hand accelerator lever is configured to have a speed-torque characteristic with a large torque fluctuation rate with respect to engine rotation speed fluctuations, and the foot accelerator pedal is drives the actuator so as to have a speed-torque characteristic with a small torque fluctuation rate with respect to engine speed fluctuations, and controls each of the controllers constituting the control unit for simultaneous operation of the hand accelerator lever and foot accelerator pedal. An engine rotation control device for a work vehicle, characterized in that the actuator is driven by using an output signal of a control system that increases engine output as a priority signal among output signals of the system. (2) An upper limit regulation circuit that regulates the upper limit value of the priority signal, and when the engine speed exceeds a predetermined value, a signal is provided that indicates that the actuator position is moving toward the fuel increase side compared to the actual position. 2. The engine rotation control device for a work vehicle according to claim 1, wherein the control section is provided with an overrun limiter circuit for outputting and controlling the position of the actuator.