KR100691665B1 - Controller for construction machine and method for operating input torque - Google Patents

Abstract

According to the present invention, the variable displacement hydraulic pump 10 driven by the prime mover 20, the hydraulic actuator 5 driven by the discharge oil from the hydraulic pump 10, and the actual rotation speed Nr of the prime mover 20 are provided. In the control apparatus of the construction machine which has the rotation speed detection means 31 which detects, WHEREIN: The prime mover control means 40B which controls the rotation speed of the prime mover 20 according to the operation amount of the operation means 14a, and rotation speed The input torque T2 of the hydraulic pump 10 is adjusted according to the deviation? N of the actual rotation speed Nr detected by the detection means 31 and the control rotation speed Nθ by the operation of the operation means 14a. The input torque control means 40A which increases and decreases is provided, The input torque control means 40A has the control rotation speed N (theta) larger than the actual rotation speed Nr, and the deviation (DELTA) N is predetermined value N2. When abnormal, control to reduce the input torque T2 is performed.

Prime mover, hydraulic pump, operating means, control speed, predetermined value.

Description

Control device of construction machinery and input torque calculation method {CONTROLLER FOR CONSTRUCTION MACHINE AND METHOD FOR OPERATING INPUT TORQUE}

The present invention relates to a control device for a construction machine that controls an input torque acting on the prime mover of the construction machine, and an input torque calculation method.

A traveling hydraulic motor driven by the discharge oil from the variable displacement hydraulic pump driven by the engine, for example, driving the vehicle by controlling the amount of hydraulic oil delivered to the hydraulic motor according to the operation of the traveling pedal; There is known a construction machine capable of controlling the engine speed according to the operation of the pedal (for example, Japanese Patent No. 2633095).

In the construction machine of the said publication, input torque control by speed sensing as follows is performed. That is, a target torque for preventing engine stall from the actual engine speed detected by the speed sensor and the target speed corresponding to the position of the governor lever of the engine is calculated, and from this target torque The target pump tilt angle is obtained to control the pump tilt angle. In the calculation of the target torque, only the control in the direction in which the input torque increases, the control in the direction in which the input torque decreases is not performed. Accordingly, the tilt angle of the hydraulic pump is maintained at a predetermined value or more, thereby ensuring smooth acceleration.

By the way, in order to suppress generation | occurrence | production of graphite, the exhaust gas compatible engine is used recently. The engine for exhaust gas is made to reduce the engine output torque of the low rotation side in the full load performance curve of the engine compared with the conventional one. More specifically, while the highest output torque of the engine is shifted to the high rotation side, the torque rise of the medium rotation range is reduced from the low rotation range, and the torque rise of the high rotation range is increased from the medium rotation range. As a result, fuel consumption on the low rotation side is suppressed, and generation of graphite is suppressed.

When the input torque control described in the above publication is performed when such an exhaust gas compatible engine is used, the following problem occurs. That is, in the construction machine described in the above publication, since the control to reduce the input torque is not performed, the input torque may exceed the engine output torque and cause engine stall when the running load increases, such as at the start of the run or when the vehicle is running uphill. There is.

An object of the present invention is to provide a control device for a construction machine and an input torque calculation method which are suitable for use in an exhaust gas-compatible engine.

The present invention is applied to a construction machine having a variable displacement hydraulic pump driven by a prime mover, a hydraulic actuator driven by discharge oil from the hydraulic pump, and a rotation speed detecting means for detecting the actual rotation speed of the prime mover. And this control apparatus carries out hydraulic pressure according to the prime mover control means which controls the rotation speed of a prime mover according to the operation amount of an operation means, and the deviation of the actual rotation speed detected by the rotation speed detection means, and the control rotation speed by operation of an operation means. An input torque control means for increasing or decreasing the input torque of the pump is provided, and when the control rotation speed is larger than the actual rotation speed and the deviation is more than a predetermined value, control is performed to reduce the input torque.

Moreover, the control apparatus of the construction machine which concerns on this invention is a control part by the control of the prime mover control means which controls the rotation speed of a prime mover according to the operation amount of an operation means, and the actual rotation speed detected by the rotation speed detection means, and an operation means. Input torque control means for increasing or decreasing the input torque of the hydraulic pump in accordance with the deviation of the number, and when the control rotation speed is larger than the actual rotation speed and the deviation is more than the predetermined value, the input torque is made larger than when the deviation is less than the predetermined value. A control to reduce is performed.

As a result, the engine stall can be prevented, and good acceleration can be obtained, and the engine can be preferably used for an exhaust gas-compatible engine.

When the control rotational speed is larger than the actual rotational speed and the deviation is less than the predetermined value, it is preferable to set the increase / decrease amount of the input torque to zero. The change rate of the input torque when the control rotational speed is larger than the actual rotational speed and the deviation is more than the predetermined value may be larger than the change rate of the input torque when the control rotational speed is smaller than the actual rotational speed.

The hydraulic actuator can be used as a traveling hydraulic motor, and the operation means can be configured as a traveling pedal. You may reduce the input torque at the time of non-driving rather than the input torque at the time of running.

It is preferable to apply this invention to a wheel type hydraulic excavator.

The reference torque is calculated according to the deviation between the control rotational speed and the actual rotational speed of the prime mover, and the correction torque is 0 when the control rotational speed is larger than the actual rotational speed and the deviation is less than or equal to the predetermined value. May be set as a negative value, and the input torque may be calculated by adding the reference torque to the correction torque.

1 is a view showing the appearance of a wheel-type hydraulic excavator applied to an embodiment of the present invention.

2 is a view showing a hydraulic circuit of the control device according to the embodiment of the present invention.

3 is a P-qp line diagram of a variable displacement hydraulic pump.

4 is a diagram showing a full load performance curve of an engine applied to an embodiment of the present invention.

5 is a block diagram of a control device according to an embodiment of the present invention.

It is a figure explaining the detail of an input torque control circuit.

It is a figure explaining the detail of an engine speed control circuit.

8 is a flowchart illustrating an engine speed control procedure.

9 is a view showing the operation characteristics by the control device according to an embodiment of the present invention.

1 to 9, an embodiment in which the control device for a construction machine according to the present invention is applied to a wheel type hydraulic excavator will be described.

As shown in FIG. 1, the wheel type hydraulic excavator has a traveling body 1 and a swinging body 2 rotatably mounted on the upper side of the traveling body 1. The swinging structure 2 is provided with the work front attachment 4 which consists of the cab 3, the boom 4a, the arm 4b, and the bucket 4c. The boom 4a is undulated by the drive of the fire cylinder 4d, the arm 4b is undulated by the drive of the arm cylinder 4e, and the bucket 4c is driven by the drive of the bucket cylinder 4f. By cloud or by dump. The traveling body 1 is provided with the traveling hydraulic motor 5 by hydraulic drive, and the rotation of the traveling hydraulic motor 5 is transmitted to the wheel 6 (tire) via a propeller shaft and an axle.

The traveling and working hydraulic circuits are shown in FIG. The variable displacement hydraulic pump 10 is connected to the hydraulic motor 5 via the control valve 11, and to the hydraulic cylinder (for example, the boom cylinder 4d) via the control valve 12. The pilot port of the control valve 11 is connected to the pilot valve 14 via the forward and backward conversion valve 13, and the pilot port of the control valve 12 is connected to the pilot valve 15.

The forward and backward switching valve 13 is converted by a switch (not shown), and the pilot valve 14 is driven in accordance with the operation amount of the travel pedal 14a. When the forward / backward switching valve 13 is switched to the forward position or the backward position by the switch operation, and the traveling pedal 14a is operated, the pilot pressure from the hydraulic pressure source 16 acts on the control valve 11. As a result, the control valve 11 is driven so that the hydraulic oil from the hydraulic pump 10 is supplied to the hydraulic motor 5, and the vehicle can be moved forward or backward by the rotation of the hydraulic motor 5.

On the other hand, the pilot valve 15 is driven in accordance with the operation amount of the operation lever 15a. When the operation lever 15a is operated, the pilot pressure from the hydraulic pressure source 17 acts on the control valve 12. Thereby, the control valve 12 is driven, the hydraulic oil from the hydraulic pump 10 is supplied to the boom cylinder 4d, and excavation work etc. can be performed by driving the boom cylinder 4d.

The hydraulic pump 10 is driven by the engine 20, and the pump tilt angle qp is changed by the regulator 30. The pump discharge pressure is fed back to the regulator 30, and horsepower control is performed. Horsepower control is what is called P-qp control as shown in FIG. At the same time, in this embodiment, as described later, speed sensing is performed to calculate the input torque, and the pump tilt angle pq is controlled according to the input torque. As a result, the input torque is increased or decreased as shown in FIG. 3.

In this embodiment, an exhaust gas compatible engine is used to suppress the generation of graphite. 4 is a characteristic diagram showing the full load performance curve of the engine, and the engine characteristics corresponding to the exhaust gas are shown by the solid line, and the engine characteristics not corresponding to the exhaust gas are shown by the dotted lines. As shown in FIG. 4, an exhaust gas-compatible engine is made smaller the output torque T on the low rotation side. More specifically, while the maximum output torque is shifted to the high rotation side, the torque rise of the middle rotation region is reduced from the low rotation region, and the torque rise of the high rotation region is increased from the middle rotation region. By using the engine of such a characteristic, fuel consumption on the low rotation side is suppressed and generation | occurrence | production of graphite is suppressed.

5 is a block diagram of a control device according to the present embodiment. The governor lever 21 of the engine 20 is connected to the pulse motor 23 via the link mechanism 22, and the engine speed is controlled by the rotation of the pulse motor 23. In other words, the engine speed increases due to the electrostatic discharge of the pulse motor 23, and decreases in reverse. The rotation of the pulse motor 23 is controlled as described later by a control signal from the controller 40. A potentiometer 24 is connected to the governor 21 via a link mechanism 22. The potentiometer 24 detects the governor lever angle corresponding to the rotation speed of the engine 20, and the engine control rotation speed. It is input to the controller 40 as Nθ.

The controller 40 further includes a rotation speed sensor 31 for detecting the actual rotation speed Nr of the engine 20, a position sensor for detecting the change position of the brake switch 32, and the forward and backward conversion valve 13. (33), a detector 35 for detecting an operation amount X of the fuel lever 34 that is an operation member for engine speed command, and a pressure sensor 36 for detecting a pilot pressure Pt according to the operation amount of the travel pedal 14a. Is connected.

 The brake switch 32 is converted into driving, working and parking positions to output work / driving signals. When the vehicle is switched to the driving position, the parking brake is released, and the brake pedal allows the operation of the service brake. When shifted to the working position, activate the parking brake and service brake. When the vehicle is switched to the parking position, the parking brake is activated. The brake switch 32 outputs an off signal when converted to the travel position, and outputs an on signal when converted to the work and parking position.

The controller 40 has a torque controller 40A for controlling the input torque and a rotation controller 40B for controlling the engine speed. 6 is a conceptual diagram illustrating the details of the torque control unit 40A.

The torque control unit 40A includes a deviation calculator 41 for calculating the deviation? N between the engine actual rotation speed Nr and the control rotation speed Nθ, the reference torque calculators 42 and 43 for calculating the reference torques TB1 and TB2, respectively, and correction. Correction torque calculation units 44 and 45 for calculating torques ΔT1 and ΔT2, coefficient calculation units 46 and 47 for calculating coefficients respectively, and multiplier 48 for multiplying correction torques ΔT1, ΔT2 and coefficients, respectively. And 49), adders 50 and 51 for calculating the target input torques T1 and T2 by adding the correction torques ΔT1, ΔT2 and the reference torques TB1, TB2 after multiplication, respectively, and one of the target input torques T1, T2. And a selection unit 52 for selecting a and a conversion unit 53 for outputting a control signal i for controlling with the selected target input torque T1 or T2.

The reference torque calculating section 42, the correcting torque calculating section 44, and the coefficient calculating section 46 are set with characteristics suitable for the work, respectively, and the reference torque calculating section 43, the correcting torque calculating section 45, and the coefficient calculating section 47, respectively. Characteristics suitable for running are set.

The calculation by the torque control part 40A is demonstrated in detail.

The deviation calculating unit 41 calculates the deviation? N (= Nr-Nθ) between the engine actual rotation speed Nr detected by the rotation speed sensor 31 and the control rotation speed Nθ detected by the potentiometer 24, and this deviation ? N is input to the correction torque calculating sections 44 and 45, respectively. In each of the correction torque calculating sections 44 and 45, the relationship between the deviation? N and the correction torques? T1 and? T2 is stored in advance as shown in the drawing. Compute each.

According to the characteristic of the correction torque calculating part 44, when the deviation (DELTA) N is positive, correction torque (DELTA) T1 is also positive, and correction torque (DELTA) T1 increases proportionally with increase of deviation (DELTA) N. When the deviation DELTA N is negative, the correction torque DELTA T1 is also negative, and as the deviation DELTA N decreases, the correction torque DELTA T1 decreases proportionally (| ΔT1 | is increased). In this case, the characteristic inclination when the deviation? N is positive is the same as the characteristic inclination when the deviation? N is negative.

On the other hand, according to the characteristic of the correction torque calculating part 45, when deviation (DELTA) N is positive, correction torque (DELTA) T2 is also positive, and correction torque (DELTA) T increases proportionally with increase of deviation (DELTA) N. On the other hand, when the deviation ΔN is negative, the correction torque ΔT 2 is 0 from 0 to the predetermined value N 2, and when the deviation ΔN is smaller than the predetermined value N 2, the correction torque ΔT 2 is reduced according to the decrease of the deviation ΔN. Decrease proportionally. The characteristic slope when the deviation? N is smaller than the predetermined value N2 is greater than the characteristic slope when the deviation? N is positive.

In each of the reference torque calculating sections 42 and 43, the relationship between the control rotation speed Nθ and the reference torques TB1 and TB2 is stored in advance, and the reference torques TB1 and TB2 according to the control rotation speed Nθ are respectively calculated from this characteristic. . In each coefficient calculating section 46, 47, a characteristic in which the coefficient increases proportionally with respect to the control rotation speed Nθ is stored in advance, and a coefficient according to the control rotation speed Nθ is calculated from this characteristic. Each multiplier 48, 49 multiplies the correction torques DELTA T1 and DELTA T2 calculated by the corrected torque calculating units 44, 45 by the coefficients calculated by the coefficient calculating units 46, 47.

Each adder 50, 51 adds the correction torque? T multiplied by the multipliers 48, 49 and the reference torques TB1, TB2 calculated by the reference torque calculators 42, 43, respectively, to obtain the target input torque T1, Calculate T2

The selector 52 determines whether or not the vehicle travels by the signals from the brake switch 32, the position sensor 33, and the pressure sensor 36. That is, when the brake switch 32 is turned off, the forward / backward conversion valve 13 is out of the neutral position, and the pilot pressure Pt by the operation of the travel pedal 14a is equal to or higher than a predetermined value, it is determined that the vehicle travels. In other conditions, the vehicle is determined to be non-driving. Then, the target input torque T2 is selected when the vehicle is running, and the target input torque T1 is selected when the vehicle is not running (for example, during work).

The converter 53 calculates a control signal i according to the selected target input torque T1 or T2. Although not shown, the pump regulator 30 is provided with a cylinder for adjusting the tilt angle and a solenoid valve for controlling the flow of pressure oil to the cylinder, and the control signal i from the converter 53 is output to the solenoid valve. The pump tilt angle qp is thereby changed, so that the input torque is controlled to the target input torque T1 or T2.

7 is a conceptual diagram illustrating the details of the rotation speed control unit 40B. In the target rotational speed calculating section 61, a relationship between the detected value X by the detector 35 and the target rotational speed Nx is stored in advance as shown in the drawing, and from this characteristic, the target rotational speed according to the operation amount of the fuel lever 34 is shown. Calculate Nx In the target rotational speed calculating section 62, the relationship between the detected value Pt by the pressure sensor and the target rotational speed Nt is stored in advance as shown in the drawing. From this characteristic, the target rotational speed Nt in accordance with the operation amount of the travel pedal 14a is calculated. Calculate

In this case, the target rotational speeds Nx and Nt increase linearly from the idle rotational speed Ni as the characteristic of each target rotational speed calculating part 61 and 62 also increases. The maximum target rotation speed Nxmax of the target rotation speed calculation unit 61 is set lower than the maximum rotation speed of the engine 20, and the maximum target rotation speed Ntmax of the target rotation speed calculation unit 62 is equal to the maximum rotation speed of the engine 20. It is set almost identically. Therefore, the maximum target rotation speed Ntmax is larger than the maximum target rotation speed Nxmax.

The selection unit 63 selects a larger value of the target rotation speeds Nx and Nt calculated by the target rotation speed calculation units 61 and 62. The servo control unit 64 compares the selected rotational speed (rotational speed command value Nin) with the control rotational speed Nθ corresponding to the displacement amount of the governor lever 21 detected by the potentiometer 24. And the pulse motor 23 is controlled so that both may correspond according to the procedure shown in FIG.

In FIG. 8, the rotation speed command value Nin and the control rotation speed N (theta) are respectively read in step S21, and it progresses to step S22 first. In step S22, the result of Nθ-Nin is stored in the memory as the speed difference A, and in step S23, it is determined whether | A | ≥K using the predetermined reference speed difference K. If it is affirmative, it progresses to step S24 if it is affirmed, and it is determined whether the rotation speed difference A> 0, and if A> 0, since the control rotation speed N (theta) is larger than rotation speed command value Nin, ie, the control rotation speed is higher than target rotation speed, In order to lower the engine speed, a signal for commanding motor reversal is output to the pulse motor 23 in step S25. As a result, the pulse motor 23 reverses and the engine speed decreases.

On the other hand, when A? 0, since the control rotation speed Nθ is smaller than the rotation speed command value Nin, that is, the control rotation speed is lower than the target rotation speed, a signal for commanding the motor power failure is output in step S26 to increase the engine speed. As a result, the pulse motor 13 is out of power and the engine speed is increased. If step S23 is negative, the process proceeds to step S27 to output a motor stop signal, whereby the engine speed is maintained at a constant value. Execution of steps S25 to S27dmf returns to the start.

Next, the characteristic operation of the control apparatus which concerns on a present Example is demonstrated.

At the start of the vehicle running, the brate switch 32 is operated to the traveling position, and the forward and backward conversion valve 13 is converted to the forward or backward position. In this state, for example, when the fuel lever 34 is operated to the idling position and the driving pedal 14a is operated to the maximum in order to maximize the driving force, the traveling motor ( 5) is driven and the vehicle starts to run. At this time, since the target rotational speed Nt by the travel pedal 14a is larger than the target rotational speed Nx by the fuel lever 34, the selection unit 63 selects the target rotational speed Nt as the rotational speed command value Nin, and FIG. According to the procedure of 8, the governor lever position is controlled so that the actual rotational speed coincides with the rotational speed command value Nin. As a result, the governor lever 21 is greatly displaced, and the control rotation speed Nθ is increased as indicated by the broken line in Fig. 9A.

When the control speed Nθ increases, the actual engine speed Nr also increases. However, since there is a time lag until the engine actual speed Nr reaches the control speed Nθ, the deviation ΔN becomes negative between these time lags. The engine output torque T in this case is as shown in Fig. 9B, and this characteristic is guided from the characteristic in Fig. 4.

At the time of vehicle travel, the selection unit 52 selects the target input torque T2. Therefore, the torque control part 40A performs speed sensing according to the characteristic of the correction torque calculating part 45. FIG. Immediately after the start of the operation of the travel pedal 14a, since the deviation | ΔN | is larger than the predetermined value N2, the correction torque calculating section 45 calculates the negative correction torque? T2. Therefore, as shown in Fig. 9B, the input torque T2 at the start of travel becomes smaller than the output torque T, so that engine stall can be avoided.

When the actual engine speed Nr rises and the deviation | ΔN | decreases, the negative correction torque DELTA T2 decreases accordingly, and when the deviation | ΔN | becomes less than the predetermined value N2, the correction torque DELTA T2 becomes zero. Thus, by setting correction torque DELTA T to 0 before the deviation | ΔN | becomes 0, input torque T2 can be recovered early to the reference torque TB2 equivalent, and favorable acceleration can be obtained. And as shown in FIG.9 (b), in the process of increasing input torque T2, although there exists a possibility that input torque T2 may exceed output torque T in the short run, since the difference of input-output torque T-T2 is small, No problem in practical use. The above embodiment is more effective in the case where the load on the vehicle becomes large, and the same action is applied not only at the start of driving but also at the time of climbing.

The characteristic T20 of FIG. 9B is a conventional input torque characteristic, that is, a characteristic in the case where the correction torque ΔT is uniformly maintained at 0 when the deviation ΔN is negative. According to this characteristic, when the deviation? N is denied, the input torque T20 does not become smaller than the reference torque. Therefore, when an exhaust gas compatible engine with a small output torque is used, the input torque T20 at the start of traveling may exceed the engine output torque T, resulting in engine stall.

At the time of work, the brake switch 32 is operated to a working position, and the forward and backward conversion valve 13 is changed to a neutral position. In this state, when the operation of the travel pedal 14a is stopped and the fuel lever 34 is required to operate, the selector 63 of the rotation speed control unit 40B is the target by the fuel lever 34 as the rotation speed command value Nin. The rotation speed Nx is selected and the governor lever position is controlled so that the actual rotation speed matches the rotation speed command value Nin. At this time, the selecting unit 52 of the torque control unit 40A selects the target input torque T1, and the torque control unit 40A performs speed sensing in accordance with the characteristics of the correction torque calculating unit 44. Since the deviation? T of the correction torque calculating section 44 is also negative, the input torque T1 is always smaller than the output torque T as shown in Fig. 9C.

According to this embodiment, the following effects can be obtained.

(1) When the deviation? N between the engine actual rotation speed Nr and the control rotation speed Nθ is negative, and the deviation | ΔN | is larger than the predetermined value N2, the correction torque? T2 is negative, and | ΔN | is the predetermined value N2. When it was below, the correction torque (DELTA) T2 was made into zero. Accordingly, even when an engine for exhaust gas is used, the input torque T2 at the start of traveling can be made smaller than the output torque T, and engine stall can be prevented and good acceleration can be ensured.

(2) The deviation? N was negative, and the inclination of the correction torque? T when the deviation | ΔN | was larger than the predetermined value N2 was made larger than the inclination of the correction torque? T when the deviation? N was positive. As a result, when the deviation? N approaches the predetermined value N2, the input torque T2 can be recovered to the reference torque TB2 early, and hunting can be prevented when the deviation? N is positive.

(3) The characteristics for calculating the correction torque ΔT in running and non-driving were changed so that acceleration was not a problem during non-driving, so that the correction torque ΔT was added when the deviation ΔN was negative. Accordingly, at the time of work, the input torque T1 can always be kept below the output torque T.

Incidentally, in the above embodiment, the correction torque DELTA T2 is 0 within the range of N2≤ΔN≤0. However, when the deviation DELTA N is denied, the inclination of the correction torque DELTA T2 is set as the boundary. If it has the characteristic to change to two stages, it is not necessary to make correction torque (DELTA) T2 into 0 necessarily.

As mentioned above, although the example which ensures the acceleration of the traveling hydraulic motor 5 at the time of vehicle running was shown, it is not limited to this, For example, you may apply to the turning hydraulic motor which turns the upper swing structure of a vehicle. Therefore, the operation means is also not limited to the travel pedal 14a.

As mentioned above, although the wheel type hydraulic excavator was demonstrated as an example as a construction machine, this invention is applicable also to construction machines other than a wheel type.

Claims (8)

A variable displacement hydraulic pump driven by a prime mover, A hydraulic actuator driven by the discharge oil from the hydraulic pump, In the control apparatus of the construction machine which has a rotation speed detection means which detects the actual rotation speed of the said prime mover, A prime mover control means for controlling the number of revolutions of the prime mover in accordance with an operation amount of an operation means; Input torque control means for increasing or decreasing the input torque of the hydraulic pump in accordance with the deviation between the actual rotation speed detected by the rotation speed detection means and the control rotation speed by the operation of the operation means; And The input torque control means performs control to reduce the input torque when the control rotation speed is larger than the actual rotation speed and the deviation is more than a predetermined value, And said input torque control means sets the amount of increase and decrease of input torque to zero when the control rotation speed is larger than the actual rotation speed and the deviation is less than said predetermined value. A variable displacement hydraulic pump driven by a prime mover, A hydraulic actuator driven by the discharge oil from the hydraulic pump, In the control apparatus of the construction machine which has a rotation speed detection means which detects the actual rotation speed of the said prime mover, A prime mover control means for controlling the number of revolutions of the prime mover in accordance with an operation amount of an operation means; Input torque control means for increasing or decreasing the input torque of the hydraulic pump in accordance with the deviation between the actual rotation speed detected by the rotation speed detection means and the control rotation speed by the operation of the operation means; And  The input torque control means performs control to greatly reduce the input torque when the control rotation speed is larger than the actual rotation speed and the deviation is greater than or equal to the predetermined value, when the deviation is less than the predetermined value, And said input torque control means sets the amount of increase and decrease of input torque to zero when the control rotation speed is larger than the actual rotation speed and the deviation is less than said predetermined value. delete The method according to claim 1 or 2, The input torque control means performs control to increase the input torque in accordance with the increase in the deviation when the control rotation speed is smaller than the actual rotation speed, The control of the construction machine characterized in that the rate of change of the input torque when the control speed is larger than the actual speed and the deviation is greater than or equal to the predetermined value is greater than the rate of change of the input torque when the control speed is smaller than the actual speed. Device. The method according to claim 1 or 2, And said hydraulic actuator is a traveling hydraulic motor, and said operation means is a traveling pedal. The method of claim 5, And traveling detecting means for detecting traveling and non-driving, And the input torque control means reduces the input torque significantly when the running speed is detected by the travel detecting means when the control speed is greater than the actual speed. The control device according to claim 1 or 2 Wheel type hydraulic excavator characterized in that it comprises a. An input torque calculation method input by a hydraulic circuit having at least a variable displacement hydraulic pump driven by a prime mover and a hydraulic actuator driven by discharge oil from the hydraulic pump, Calculate a reference torque according to the deviation between the control rotational speed and the actual rotational speed of the prime mover, When the control rotation speed is larger than the actual rotation speed and the deviation is less than or equal to the predetermined value, the correction torque is zero, and when the deviation is greater than the predetermined value, the correction torque is negative. And calculating the input torque by adding the reference torque to the correction torque.

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