JPH057550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic governor device for an internal combustion engine that controls the rotational speed of the engine by controlling the load of a fuel injection pump.

[Summary of the Invention] The present invention provides a governor device that controls the rotational speed of an engine by controlling the rack of a fuel injection pump, which uses a speed detection signal indicating the actual rotational speed of the engine and a rack position detection signal indicating the position of the rack. and an instruction speed signal indicating the instruction rotation speed instructed by the accelerator operating member, and an operation signal for constant speed control to perform control to maintain the deviation between the actual engine rotation speed and the instruction rotation speed within a permissible range. Generate operating signals for maximum easy position control to perform control to keep the deviation between the position of By supplying it to the circuit side, it is possible to perform both constant speed rotation control and maximum rack position control.

[Prior Art] In an internal combustion engine such as a diesel engine that is supplied with fuel by a fuel injection pump, the rotational speed [rpm] is controlled by controlling the position of the rack (injection amount adjusting means) of the fuel injection pump. It's on.

An electronic governor device for controlling the rotational speed by controlling the rack position of a fuel injection pump for an internal combustion engine is disclosed in Japanese Patent Application Laid-Open No. 171037/1983.
This conventional electronic governor device uses a rotational speed detection signal obtained from a sensor that detects the rotational speed of the engine, a rack position detection signal obtained from a sensor that detects the rack position of the fuel injection pump, and the position of the accelerator operating member. Based on the accelerator position detection signal obtained from the detected sensor, the target position of the rack required to obtain the rotational speed of the engine indicated by the accelerator position is calculated. Then, a control voltage necessary to position the rack at the calculated target position of the rack is generated, and the rack is moved to the target position by driving an actuator that operates the rack with this control voltage.

Furthermore, in internal combustion engines, torque is determined by the amount of fuel supplied, but since it is desirable to keep the output (torque x number of revolutions) approximately constant at each rotation speed, there is an upper limit to the amount of fuel that can be supplied at each rotation speed. Generally, the maximum fuel supply amount decreases as the engine rotational speed increases in the rotational speed range above the maximum torque generation rotational speed. In this way, in an internal combustion engine, the maximum fuel supply amount is determined at each rotational speed, so when a fuel injection pump is used, the maximum easy position [in this specification, rack is the open position side] is determined at each rotational speed. This refers to the permissible limit position when shifting to the fuel increase side. ] has been determined. Therefore, in the conventional apparatus described above, a predetermined maximum rack position is calculated based on the rack position detection signal and the rotation speed detection signal, and control is performed so that the rack position does not exceed the maximum rack position at each rotation speed.

The characteristics of the engine obtained with the above-mentioned conventional device are as shown in FIG. In other words, no load (torque T
= 0) When the engine rotational speed N is Ns, keeping the accelerator position and increasing the load torque T from zero to the full load torque To, the engine rotational speed will be
This is a so-called droop characteristic that decreases to No (<Ns). Next, when the rack position reaches the maximum rack position at full load torque To, control is performed to maintain the rack position at the maximum rack position according to the maximum rack position characteristics for further load torque. ) The rotational speed N of the engine decreases.

[Problems to be Solved by the Invention] In the conventional governor device described above, the characteristics with respect to load fluctuations are droop characteristics, and constant speed characteristics cannot be obtained. Therefore, it is necessary to maintain the rotational speed constant against load fluctuations. It could not be used for certain purposes.

For example, an internal combustion engine that drives a welder generator used for both welding loads and general loads is required to have the characteristics shown in FIG. By switching the windings, this welder generator can be used both as a 50/60Hz constant frequency alternating current generator and as a welding machine drive generator. When used, characteristics are required to keep the rotational speed (generator output frequency) constant against variations in load torque (generator load variations). In this case, the operating load range of the engine is from no load to full load To,
It is required to maintain the engine rotational speed at a constant value No within this load range. On the other hand, when used as a generator to drive a welding machine, the full load torque To
It is required to maintain the rack position at the maximum rack position at each rotational speed in order to cause the engine to generate as much power as possible.

As mentioned above, with conventional electronic cabana devices, it was not possible to maintain the rotational speed constant against fluctuations in load torque, so when applied to an internal combustion engine that drives an alternator, As a result, the output frequency of the generator fluctuated, making it impossible to supply high-quality power to the load.

An object of the present invention is to provide an electronic governor device for an internal combustion engine that can perform both constant speed rotation control and maximum ease position control.

[Means for Solving the Problems] The present invention is an electronic governor device for an internal combustion engine that controls the rotational speed of an internal combustion engine to which fuel is supplied by a fuel injection pump whose fuel injection amount is adjusted by a rack. .

The present invention will be described with reference to FIG. 1 showing an embodiment thereof. Reference numeral 1 indicates an internal combustion engine to be controlled, and 2 operates an electrically driven fuel injection pump that supplies fuel to the internal combustion engine 1. Easy operation means. 3 is a speed detection device that detects the rotation speed of the internal combustion engine 1 and outputs a speed detection signal Vn; 4 is a speed detection device that detects the position of an accelerator operation member that sets the rotation speed of the internal combustion engine and corresponds to the position of the accelerator operation member; This is an instruction speed signal generation circuit that outputs an instruction speed signal Vno indicating an instruction rotation speed. 5 is a rack position detection device that detects the rack position and outputs a rack position detection signal VL indicating the rack position; 6 is a rack position detection device that receives a speed detection signal Vn and an instruction speed signal Vno as inputs to determine the actual rotation speed and the instruction rotation speed; 7 is a speed deviation calculation circuit that outputs a constant speed control operation signal Vnd to maintain the deviation within the allowable range, and 7 inputs the speed detection signal Vn and the rack position detection signal VL to calculate the rack position and each rotation. Operation signal for controlling the maximum easy position to control the deviation between the maximum easy position and the speed within the permissible range
This is a rack position deviation calculation circuit that outputs VLd.
8 is an operation signal for constant speed control according to predetermined conditions.
This is a control mode switch that selects and outputs Vnd and the operation signal VLd for maximum rack position control.This switch outputs the operation signal Vnd for constant speed control when the speed detection signal Vn is higher than the commanded speed signal Vno. death,
When the speed detection signal Vn is smaller than the instructed speed signal and the rack position is before the maximum rack position, the constant speed control operation signal Vnd is output, and when the speed detection signal Vn is smaller than the instructed speed signal Vno and the rack position is When the maximum rack position is exceeded, the maximum rack position control operation signal VLd is output. 9
is an integrator that integrates the output of the control mode switch 8, and the output signal Vi of this integrator 9 is input to the manipulated variable calculation circuit 11. The operation amount calculating circuit 11 calculates the amount of operation of the rack operating means necessary to bring the deviation of the rotational speed or the deviation of the rack position within a certain range, and supplies this operation amount to the drive circuit 12. The drive circuit 12 drives the rack operating means 2 in accordance with the operation amount calculated by the calculation circuit 11 to move the rack closer to the target position.

[Operation of the invention] As described above, by providing the control mode switch 8,
When the speed detection signal Vn is higher than the commanded speed signal Vno, and when the speed detection signal Vn is smaller than the commanded speed signal and the rack position is before the maximum rack position, the constant speed control operation signal Vnd is input to the integrator. control to maintain the deviation between the engine rotational speed and the commanded rotational speed within the permissible range, and when the speed detection signal Vn is smaller than the commanded speed signal Vno and the rack position exceeds the maximum rack position. If the operation signal VLd for maximum rack position control is input to the integrator and control is performed to keep the deviation between the rack position and the maximum rack position at each rotation speed within the permissible range, the engine's It is possible to perform both constant speed rotation control to keep the rotation speed constant and maximum rack position control to keep the rack position at the maximum rack position at each rotation speed. Therefore, like internal combustion engines used in engine generators that need to drive both welding loads and general loads, the characteristics of keeping the rotational speed constant despite load fluctuations and the position of the rack at the maximum at each rotational speed are required. This is useful when both the characteristics of maintaining the torque in the easy position and generating torque near the full load torque are required.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of an embodiment of the present invention. In the figure, reference numeral 1 indicates an internal combustion engine (in this example, a diesel engine), and this internal combustion engine has an injection amount control member (an injection amount adjusting member). It is equipped with a fuel injection pump whose quantity is regulated. Reference numeral 2 denotes a rack operating means that is electrically driven to operate the rack of the fuel injection pump of the internal combustion engine 1;
As a drive source, a rack may be operated using a motor as a drive source, or an electromagnetic plunger may be used as a drive source to operate the rack.

In this example, the rotational speed N and the maximum ease position are
Assume that there is a relationship shown in FIG. 3A between Lm and Lm.
That is, in a rotation range where the engine rotational speed N [rpm] is less than or equal to the set circuit speed N1, a constant position L1 on the open position side is set as the maximum easy position, and control is performed to maintain the easy position at this maximum easy position. In the rotational range of speed N1 or higher, the rack position is directly changed to the closed position side as the rotational speed increases. The torque of the engine is determined by the position of the rack of the fuel injection pump, and when the position of the rack is moved to the open position side (to the side where the injection amount is increased), the engine torque increases. In Fig. 3 A, the rotation speed
N1 is the rotational speed that produces the maximum torque Tm (see Figure 3 B), which means that if the maximum ease position Lm is greater than L1, there is a risk of engine damage. In the region of rotation speed N1 or higher, in order to keep the engine's maximum output (rotation speed x maximum torque) constant,
The maximum easy position is brought closer to the closed position so that the maximum fuel injection amount is decreased as the rotational speed increases. Therefore, in this example, the rack position at each rotational speed is the maximum rack position shown in FIG. 3A.
Control is performed so as not to exceed Lm. In this embodiment, No. shown in FIG. 3A is the designated rotational speed designated by an accelerator operating member (not shown). In this case, the rack position is controlled so as not to exceed the maximum rack position Lo at the specified rotational speed No (the rack position that produces the maximum torque To at the specified rotational speed No), and as shown in Fig. 3B, In the range up to the maximum load torque To at rotational speed No., the engine rotational speed N is set to the specified rotational speed No.
The rack position is controlled between the closed position and the maximum rack position Lo to perform constant speed rotation control so that the rack position is maintained at Maximum rack position control is performed to maintain the rack at the maximum rack position. In the load range in which maximum rack position control is performed, the rotational speed of the engine fluctuates in response to increases and decreases in load, but the rack position is maintained at the maximum rack position at each rotational speed.

Reference numeral 3a denotes a rotational speed sensor, such as a speed generator, for detecting the rotational speed of the internal combustion engine, and the frequency of the output of this sensor is proportional to the rotational speed of the engine. 3b
is a frequency conversion circuit (F/V conversion circuit) that converts the frequency of the output of the sensor 3a into voltage and outputs a speed detection signal Vn proportional to the rotational speed of the engine. A speed detection device 3 is configured.

Reference numeral 4a denotes an accelerator position sensor that detects the position of an accelerator operating member that sets the rotational speed of the internal combustion engine 1, and 4b converts the output of the sensor 4a into an instruction speed signal Vno that indicates an instruction rotational speed corresponding to the position of the accelerator operating member. This is a signal conversion circuit, and an instruction speed signal generation circuit 4 is configured by an accelerator position sensor 4a and a signal conversion circuit 4b.

A rack position sensor 5a detects the position of the rack of the fuel injection pump, and the output of this rack position sensor is input to a signal conversion circuit 5b. As shown in FIG. 3D, the rack position sensor 5a receives a detection signal that varies linearly with respect to the rack position L.
Output VL′. The signal conversion circuit 5b converts the detection signal
VL' is converted into a rack position detection signal VL that rises from zero at the fully closed position. A rack position detection device 5 is constituted by a rack position sensor 5a and a signal conversion circuit 5b. As the rack position sensor 5a, a displacement detecting means such as a potentiometer can be used, and as the rack position detection signal conversion circuit 5b, one having an appropriate configuration depending on the configuration of the rack position sensor can be used.

The command speed signal Vno and the speed detection signal Vn are input to a speed deviation calculation circuit 6. This speed deviation calculation circuit 6 inputs the speed detection signal Vn and the commanded speed signal Vno, and performs a control function to control the deviation between the actual rotational speed and the commanded rotational speed to be within a permissible range (of course including zero deviation). Operation signal for speed control
Vnd=α×(Vn−Vno) [α is proportionality constant. ] is output.

7 is the speed detection signal Vn and the rack position detection signal VL
Rack position that outputs the maximum rack position control operation signal VLd to control the deviation between the rack position and the maximum rack position at each rotational speed to be within the allowable range (of course including zero deviation) using as input. The maximum rack position deviation calculation circuit used in this embodiment includes a signal conversion circuit 7a that converts the speed detection signal Vn into a maximum rack position control speed information signal Vm having a certain functional relationship, and a speed information signal. It is constituted by an arithmetic circuit 7b which inputs Vm and rack position detection signal VL and outputs a maximum rack position control operation signal VLd.

In this embodiment, the operation signal VLd for maximum rack position control is a signal expressed by VLd=β×(Vm+VL)−Vr, and the speed information signal Vm for maximum rack position control and the rack position detection signal VL are The amount obtained by multiplying the sum by a certain coefficient β (β can be 1), β × (Vm
By controlling the deviation between +VL) and the constant value Vr to always be below the allowable range, the deviation between the maximum rack position and the actual rack position is controlled to be below the allowable range (including zero deviation, of course). have them do it. That is, when the speed information signal Vm increases, the rack position detection signal VL decreases, and when the speed information signal Vm decreases, the rack position detection signal decreases.
By performing control to increase VL, a control characteristic is obtained in which the maximum easy position decreases as the rotational speed N increases, and a control characteristic in which the maximum easy position decreases as the rotational speed increases is the first control characteristic. It is made to occur only in the rotation range equal to or higher than the set rotation speed N1 in Fig. 3A. Therefore, as the speed information signal Vm for maximum rack position control, a signal that starts changing from the set rotational speed N1 as shown in FIG. 3C is used. Such a speed information signal Vm can be obtained by subtracting the magnitude Vp of the speed detection signal at the set rotational speed N1 from the speed detection signal Vn.

The operating signal Vnd output by the speed deviation calculation circuit 6 and the operation signal output by the rack position deviation calculation circuit 7
VLd is input to the control mode switch 8.
This control mode switch 8 selects the operating signal Vnd or VLd according to predetermined conditions and supplies it to the next stage.
The conditions for selecting VLd are as follows.

(a) The engine rotational speed N is greater than or equal to the commanded rotational speed No, and the speed signal Vn is equal to the commanded speed signal Vno.
When it is above, the operation signal for constant speed control
Output Vnd.

(b) When the rotational speed N is less than the commanded rotational speed No, the speed detection signal Vn is smaller than the commanded speed signal Vno, and the rack position is before the maximum rack position, a constant speed control operation signal Vnd is output.

(c) When the speed detection signal Vn is smaller than the commanded speed signal Vno and the rack position exceeds the maximum rack position on the injection amount increasing side, the maximum rack position control operation signal VLd is output.

Operation signal output by the control mode switch 8
Vnd or VLd is input to the integrator 9 and integrated, and the integral signal Vi output from the integrator 9 is input to the manipulated variable calculation circuit 11.

In this embodiment, the speed detection signal Vn is also
0 and is differentiated, and the differential signal VD output from the differentiator 10 is input to the manipulated variable calculation circuit 11.

The operation amount calculation circuit 11 calculates the operation amount of the rack operation means 2 necessary to keep the deviation between the rotational speed N and the commanded rotational speed No. or the deviation between the rack position and the maximum rack position within a permissible range. A signal indicating the amount of operation is input to the drive circuit 12, and the drive circuit 12 drives the rack operating means 2 in accordance with the amount of operation calculated by the amount of operation circuit 11 to move the rack to a predetermined target position.

In the above embodiment, the speed detection device 3 outputs a speed detection signal Vn proportional to the rotational speed N of the engine as shown in FIG. 3C. This speed detection signal Vn is input to a speed deviation calculation circuit 6, a rack position deviation calculation circuit 7, and a differentiation circuit 10.

Furthermore, the rack position detection device 5 outputs a rack position detection signal VL that changes linearly from the fully closed position to the fully open position of the rack position L, as shown in FIG. 3D. This rack position detection signal VL is input to the rack position deviation calculation circuit 7.

Assuming that the accelerator operating member is now fixed at a position that indicates the instructed rotational speed No., the instruction speed signal generation circuit 4 outputs the instruction speed signal Vno indicating that the instruction rotational speed is No, and the speed deviation calculation circuit 6
is the constant speed rotation control operation signal Vnd=α corresponding to the deviation between the speed detection signal Vn and the commanded speed signal Vno.
Outputs (Vn−Vno). In addition, the rack position deviation calculation circuit 7 outputs an operating signal VLd for maximum rack position control.
Outputs = β (Vm + VL) - Vr.

If the engine rotational speed N is now equal to or higher than the commanded rotational speed No, the speed signal Vn will be the commanded speed signal.
Since the value is equal to or higher than Vno, the control mode switch 8 outputs the constant speed control operation signal Vnd. At this time, the integrator 9 outputs an integral signal Vi = K ₁ ∫ (Vn - Vno) αdt (K1 is a constant), and the manipulated variable calculation circuit 11 inputs this integral signal Vi and inputs the actual rotational speed N of the engine. The operation amount of the rack operation means 2 necessary to bring the deviation between the specified rotational speed No. and the specified rotational speed No. below (preferably, equal to) the allowable range is calculated, and a signal indicating the calculated operation amount is supplied to the drive circuit 12. The manipulated variable calculating circuit 11 also outputs a signal for driving the rack operating means in a direction to correct the speed fluctuation when the rotational speed fluctuates and the differentiator 10 outputs a signal.

The drive circuit 12 starts a correction operation to drive the rack operating means 2 in the direction of suppressing speed fluctuations based on the signal output from the arithmetic circuit 11 when the differential signal VD is generated, and then when the integral signal Vi is generated. When the operation amount calculated by the arithmetic circuit 11 is output, the rack operation means 2 is driven by the amount of operation. As a result, the rack moves to the closed position side to a predetermined position (the position required to make the difference between N and No less than the allowable range), and the rotational speed N changes to the indicated speed No.
approach.

If the load increases here, the rotational speed N becomes lower than the commanded rotational speed No, and the speed detection signal Vn
becomes smaller than the commanded speed signal Vno. If the load torque T at this time is lower than the maximum torque To at the designated rotational speed No, the rack position is before the maximum rack position, so the control mode switch 8 outputs the constant speed control operation signal Vnd. Therefore, the manipulated variable calculation circuit 11 calculates the manipulated variable necessary to make the difference between the rotational speed N and the commanded rotational speed No. below the allowable range, and supplies the manipulated variable to the drive circuit 12, and the drive circuit 12 The easy operation means 2 is driven by the amount of operation. Load torque T is indicated rotation speed
In the range below the maximum torque To at No., the engine rotational speed N is maintained at the commanded rotational speed No. by these operations.

In the present invention, an integrator 9 and a differentiator 10 are provided, and a proportional-integral-derivative operation (PID operation) is performed by calculating the manipulated variable from the integral value of the operation signal and the differential value of the detected value of the rotation speed. are being carried out.
By adding the integral operation in this way, the offset can be reduced. Further, by adding a differential operation, the correction operation can be started before the integral signal is generated, so that the settling time can be shortened.

Note that it is also possible to omit the differentiator 10 and perform a proportional-integral operation.

When the load torque T exceeds the maximum torque To at the specified rotational speed No, the rotational speed N becomes lower than the specified rotational speed No, the speed detection signal Vn becomes smaller than the specified speed signal Vno, and the rack position reaches the maximum rack position. The injection amount will exceed the increase side. At this time, the control mode switch 8 outputs the maximum rack position control operation signal VLd=β(Vm+VL)−Vr, and the integrator 9 outputs the integral signal Vi=K ₂ ∫{β×(Vm+
VL) − Vr}dt (K ₂ is a constant). The arithmetic circuit 11 inputs this integral signal Vi and calculates β(Vm+
Easy operation means 2 necessary to set VL) = Vr
The operation amount is calculated and this operation amount is given to the drive circuit 12. As a result, the drive circuit 12 drives the rack operating means 2 so that the deviation between the rack position and the maximum rack position is within the permissible range. That is,
When the rotational speed decreases, the speed information signal Vm decreases, so the rack operating means 2 is driven to increase the rack position detection signal VL, that is, to displace the rack toward the open position, and β(Vm
Stop the rack at the position where +VL) = Vr (set this position to be the maximum rack position). Furthermore, when the rotational speed increases, the speed information signal Vm increases, so the rack operating means 2 is driven to decrease the rack position detection signal VL, that is, to displace the rack toward the closed position, β Stop the rack at the position where (Vm + VL) = Vr.

Next, referring to FIG. 2, a specific example of the configuration of the speed deviation calculation circuit 6, rack position deviation calculation circuit 7, control mode switch 8, and integrator 9 of the configuration shown in FIG. 1 is shown. . In the embodiment shown in FIG. 2, the speed deviation calculation circuit 6 is an operational amplifier.
Consisting of OP1 and resistors R1 to R6, a speed detection signal Vn and a command speed signal Vno are input to the positive phase input terminal and negative phase input terminal of the operational amplifier OP1, respectively, and the output terminal of the amplifier OP1 is used for constant speed rotation control. An operating signal Vnd=α(Vn−Vno) is obtained. As will be described later, this operating signal is actually an integral signal fed back from the integrator.
Vi joins.

Signal conversion circuit 7a of rack position deviation calculation circuit 7
consists of an operational amplifier _OP2 and resistors R7 to R12, and the operational circuit 7b includes operational amplifiers OP3, OP4, resistors R13 to R23, and resistors R24 and R25, which also constitute a part of the control mode switch 8 to be described later.
It is made up of. The speed detection signal Vn is input to the positive phase input terminal of the operational amplifier OP2 of the signal conversion circuit 7a, and the voltage of the DC power supply (not shown) is input to the resistor R8 and R.
The voltage Vp obtained by dividing the voltage by 9 is the operational amplifier OP.
It is input to the negative phase input terminal of No.2. Therefore, the speed detection signal voltage is applied to the output side of the operational amplifier OP2.
A speed information signal Vm for maximum rack position control is obtained which corresponds to the difference between Vn and the constant voltage Vp.

The speed information signal Vm above is the rack position detection signal.
It is input to the positive phase input terminal of operational amplifier OP3 along with VL, and β(Vm+
VL) signal is obtained. This signal is an operational amplifier
It is given to the positive phase input terminal of OP4. A reference voltage Vr obtained by dividing a DC voltage (not shown) by resistors R24 and R25 is applied to the negative phase input terminal of the operational amplifier OP4, and a maximum rack position control operation signal VLd=β( Vm
+VL)-Vr is obtained. As will be described later, the integral signal Vi fed back from the integrator is actually added to this operating signal.

The control mode switch 8 connects the operational amplifier OP5 and
Flip-flop circuit composed of OP6, NAND circuit NA1, and NAND circuits NA2 and NA3
FF, a voltage dividing circuit consisting of resistors R24 and R25, inverter IN1, and analog switch A1
and A2. Analog switch A
1 and A2 have an input terminal a, an output terminal b, and a control terminal c, and when the potential of the control terminal c reaches a high level, the impedance between the input and output terminals a and b is low (almost zero). When the potential of the control terminal c becomes a low level, the impedance between the input and output terminals a and b becomes high and a cutoff state occurs.

In this control mode switch 8, when constant speed rotation control is to be performed (when the rack position is closer to the closed position than the maximum rack position at each rotation speed), since β(Vm+VL)≦Vr, the operational amplifier
OP6 output potential is low level (almost ground potential)
It is in. Also, the engine rotation speed N is the command rotation speed
Since it is repeatedly going up and down with No as the center, the potential at the output terminal of the operational amplifier OP5 is repeating a low level state and a high level state. At this time, the output of the NAND circuit NA1 is at a high level (because the output of the operational amplifier OP6 is zero). Therefore, the output of flip-flop circuit FF is at a low level.
At this time, the control terminal c of analog switch A1 is at high level, and the control terminal c of analog switch A2 is at low level.
Analog switch A1 is conductive, and analog switch A2 is in a disconnected state. Therefore, the constant speed rotation control operation signal Vnd is output through the analog switch A1.

Also, when maximum ease position control should be performed, β
Since ×(Vm+VL)>Vr, operational amplifier OP6
output becomes high level. In this state, the speed detection signal Vn is smaller than the command speed signal Vno (Vn<
Vno), the flip-flop circuit FF is inverted and the analog switch A1 is cut off.
Analog switch A2 becomes conductive. Therefore, the operating signal VLd for controlling the maximum rack position is outputted through the analog switch A2.

Next, when Vn > Vno, the output of operational amplifier OP5 becomes low level, so the output of NAND circuit NA1 becomes high level, and flip-flop circuit FF
output becomes low level. Therefore, analog switch A2 is cut off, analog switch A1 is made conductive, and constant speed rotation control operation signal Vnd is output.

In other words, the speed detection signal Vn is the commanded speed signal.
When it exceeds Vno, it returns to constant speed rotation control.

The constant speed rotation control operation signal Vnd or the maximum rack position control operation signal VLd is input to the integrator 9. Integrator 9 consists of resistors R26 and R27, capacitor C1, and an operational amplifier as a buffer.
OP7, and the operation signal Vnd or
Capacitor C1 is charged by VLd through resistor R26 or R27, and an integral operation is performed.
In order to provide a holding function, the output of the integrator 9 is fed back to operational amplifiers OP1 and OP4. Therefore, the actual constant speed control operation signal Vnd is
Vnd = Vi + (Vn - Vno) α, and the maximum rack position control operation signal VLd is given by VLd = Vi + β
It is given by (Vm + VL) - Vr.

To explain the operation of the governor device when using the circuit shown in Fig. 2, in the load range from no load to maximum load torque To shown in Fig. 3B, the analog switch A1 is closed and the operating signal Vnd is output, and the integrator 9
Therefore, Vnd=Vi+(Vn−Vno)α is integrated. The manipulated variable calculating circuit 11 calculates the manipulated variable by inputting this integral signal, and the relationship becomes stable at the point where Vn=Vno. Integrator 9 holds the output at this time.

Maximum load torque at rotational speed No.
When To is exceeded, analog switch A2 closes,
An operating signal VLd=Vi+β(Vm+VL)−Vr is output. This signal is integrated by an integrator 9. The arithmetic circuit 11 inputs this integral signal and calculates β(Vm
Calculate the amount of operation to make +VL=Vr. This moves the rack towards the maximum rack position,
The rack position becomes the maximum rack position and β(Vm+
The system becomes stable when VL=Vr. Integrator 9
holds the output at this time.

In the above embodiment, the rack position deviation calculation circuit 7
is assumed to output the operating signal VLd=β(Vm+VL)−Vr, but instead of the signal conversion circuit 7a, the rotation speed N
A function generator is provided to generate a maximum rack position signal VLm that changes as shown in FIG. 3A, and the output of this function generator (maximum rack position signal) is
By calculating the deviation between VLm and the rack position detection signal VL in the calculation circuit 7b, the operating signal VLd=
It is also possible to obtain α×(VL−VLm) and input this operation signal to the control mode switch 8. In this case, the manipulated variable calculation circuit 11 calculates the manipulated variable so that the deviation between the rack position detection signal VL and the maximum rack position signal VLm is within a permissible range.

[Effects of the Invention] As described above, according to the present invention, the speed deviation calculation circuit, the rack position deviation calculation circuit, and the control mode switch are provided, and the operation signal for constant speed rotation control and the operation for maximum rack position control are controlled. By selectively outputting the signal, constant speed rotation control and maximum easy position control can be performed.
There is an advantage in that it is possible to obtain an internal combustion engine that drives both a load whose rotational speed must be kept constant against load fluctuations and a load whose maximum torque must be generated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is a circuit diagram showing a specific configuration of the main part of FIG. 1, and FIGS. Diagrams showing the relationship between the maximum rack position and the rotational speed, the relationship between the torque and the rotational speed, the relationship between the speed detection signal and the rotational speed, and the relationship between the rack position detection signal and the rack position in the example. FIG. 5 is a diagram showing the relationship between torque and rotational speed when the governor is used. FIG. 5 is a diagram showing the characteristics required of the internal combustion engine that drives the Welder generator. DESCRIPTION OF SYMBOLS 1... Internal combustion engine, 2... Rack operation means, 3... Speed detection signal, 4... Instruction speed signal generation circuit, 5... Rack position detection device, 6... Speed deviation calculation circuit, 7... Rack position deviation calculation circuit, 8... Control mode switch,
9... Integrator, 10... Differentiator, 11... Manipulated amount calculation circuit, 12... Drive circuit.

Claims (1)

[Scope of Claims] 1. In an electronic governor device for an internal combustion engine that controls the rotational speed of an internal combustion engine to which fuel is supplied by a fuel injection pump whose fuel injection amount is adjusted by a rack operating means for operating the rack; and an instruction speed signal Vno that detects the position of an accelerator operating member that indicates the rotational speed of the internal combustion engine and indicates an instruction rotational speed No. corresponding to the position of the accelerator operating member.
a speed detection device that detects the rotational speed of the internal combustion engine and outputs a speed detection signal Vn proportional to the rotational speed; and a speed detection device that detects the position of the rack and indicates the position of the rack. A rack position detection device that outputs a rack position detection signal VL, and a rack position detection device that receives the speed detection signal Vn and the commanded speed signal Vno as inputs and controls the deviation between the actual rotational speed and the commanded rotational speed to be kept within a permissible range. A speed deviation calculation circuit that outputs a constant speed control operation signal Vnd, and the speed detection signal Vn and rack position detection signal VL.
a rack position deviation calculation circuit that inputs the above and outputs a maximum rack position control operation signal VLd for controlling the deviation between the rack position and the maximum rack position at each rotational speed to be kept within a permissible range; The constant speed control operation signal Vnd and the maximum rack position control operation signal VLd are input, and when the speed detection signal Vn is equal to or higher than the command speed signal Vno, the constant speed control operation signal Vnd is outputted; The speed detection signal Vn is the command speed signal
When the speed detection signal Vn is smaller than the command speed signal Vno and the rack position is before the maximum rack position, the constant speed control operation signal Vnd is output, and when the speed detection signal Vn is smaller than the command speed signal Vno and the rack position is before the maximum rack position, the constant speed control operation signal Vnd is output. a control mode switch that outputs the operation signal VLd for maximum rack position control when the position is exceeded; an integrator that integrates the output of the control mode switch; and an integrator that inputs the output signal Vi of the integrator to control the actual rotation a manipulated variable calculation circuit that calculates the manipulated variable of the rack operating means necessary to reduce the deviation between the speed and the indicated rotational speed or the deviation between the rack position and the maximum rack to a certain range; and the manipulated variable calculation circuit. 1. An electronic governor device for an internal combustion engine, comprising: a drive circuit that drives the rack operation means in accordance with a manipulated variable calculated by the circuit.