JP2010112075A - Device for controlling speed of actuator of working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for controlling a speed of an actuator of a working machine, which suppresses a rise in temperature of pressure oil supplied to the hydraulic actuator during the performance of deceleration control, by a relatively simple constitution. <P>SOLUTION: This device for controlling the speed of the actuator of the working machine is provided in a working machine such as a hydraulic excavator with a front working device 3, and includes: deceleration control valves 25 and 26 which control a working speed of the hydraulic actuator 23 by limiting the flow rate of the pressure oil supplied to the hydraulic actuator 23. The device also includes: oil temperature sensors 27 and 28 which detect the oil temperature of the pressure oil supplied to the hydraulic actuator 23; and a control processing means which comprises a controller 29 for controlling a regulator 22 so as to decrease a tilting angle of a variable-displacement hydraulic pump 21 depending on the rise in the temperature of the pressure oil detected by the oil temperature sensors 27 and 28, while alleviating deceleration control performed by the deceleration control valves 25 and 26. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is provided in a work machine such as a hydraulic excavator, and is provided with a deceleration control means capable of preferentially performing deceleration control of the hydraulic actuator separately from normal operation speed control of the hydraulic actuator such as a boom cylinder. The present invention relates to an actuator speed control device for a machine.

  There exists a thing shown by patent document 1 as this type of prior art. The prior art disclosed in Patent Document 1 is a back cylinder, that is, a hydraulic cylinder control device of a hydraulic excavator. The hydraulic excavator provided with the hydraulic cylinder control device includes an engine, a front working machine including a boom, an arm, and a bucket, a hydraulic actuator such as a boom cylinder, an arm cylinder, and a bucket cylinder that drives the front working machine, and these An electromagnetic proportional flow control valve for controlling the operation of the hydraulic actuator, that is, a control valve is provided. Further, although not described in Patent Document 1, this type of hydraulic excavator is usually driven by an engine and discharges pressure oil that operates the hydraulic actuator described above, and a tilt of the variable displacement hydraulic pump. And a regulator for controlling the turning angle.

A conventional hydraulic cylinder control device provided in such a hydraulic excavator, that is, an actuator speed control device, includes a plurality of actuators regardless of the position of an operation lever that operates the boom cylinder as the boom cylinder approaches the upward stroke end. Preferentially controls to reduce the operating speed of the boom cylinder by gradually reducing the supply current value to the boom electromagnetic proportional flow control valve among the electromagnetic proportional flow control valves A deceleration control means is provided. Also, the oil temperature sensor that detects the temperature of the hydraulic oil in the hydraulic piping system, and if the hydraulic oil temperature detected by this oil temperature sensor is high, the flow rate will be larger than the valve opening, so the deceleration amount by the deceleration control means And a means for controlling the deceleration amount to be smaller if the hydraulic oil temperature is low.
Japanese Patent Laid-Open No. 5-306531

  In the above-described prior art, during normal work in a general work environment, it is considered that deceleration control means can perform speed reduction control of the operating speed of a hydraulic actuator such as a boom cylinder without trouble, but the temperature of the work environment becomes high. No consideration has been given to malfunctions. That is, when a hydraulic excavator according to the prior art is operated in a high-temperature working environment such as a tropical region, the pipeline for supplying pressure oil to the hydraulic actuator is throttled by the deceleration control by the deceleration control means. The pressure oil flowing through the road generates heat, and the temperature of the pressure oil rises to about 100 ° C., for example, which may damage the hydraulic equipment including the hydraulic actuator.

  In order to cope with the temperature rise of the pressure oil supplied to the hydraulic actuator as described above during the deceleration control by the deceleration control means, a control for reducing the engine speed when the temperature rises based on a well-known technique. It is conceivable to have a configuration including means and control means for reducing the pump output so as not to cause engine stall at this time. However, such a configuration leads to complication of the drive circuit of the hydraulic actuator, which causes another problem that the manufacturing cost increases.

  The present invention has been made from the actual situation in the above-described prior art, and an object thereof is an operation capable of suppressing the temperature rise of the pressure oil supplied to the hydraulic actuator during the deceleration control with a relatively simple configuration. An object is to provide an actuator speed control device for a machine.

  In order to achieve this object, an actuator speed control device for a work machine according to the present invention includes an engine, a variable displacement hydraulic pump driven by the engine, a regulator for controlling a tilt angle of the variable displacement hydraulic pump, A working machine having a hydraulic actuator that is operated by pressure oil discharged from the variable displacement hydraulic pump and a control valve that controls a flow of pressure oil supplied from the variable displacement hydraulic pump to the hydraulic actuator when performing work. In an actuator speed control device for a work machine, which is provided with a deceleration control means that limits the flow rate of pressure oil supplied to the hydraulic actuator and performs deceleration control of the operating speed of the hydraulic actuator, the hydraulic oil is supplied to the hydraulic actuator. Oil temperature detecting means for detecting the temperature of the pressurized oil and the oil The regulator is controlled so as to reduce the tilt angle of the variable displacement hydraulic pump in accordance with the increase in the temperature of the pressure oil detected by the detecting means, and at the same time, the deceleration control is more relaxed than before. And a control processing means for controlling the deceleration control means.

  The present invention configured as described above is, for example, when the work by the operation of the hydraulic actuator is performed in a high-temperature work environment such as a tropical region, and when the deceleration control of the hydraulic actuator is performed by the deceleration control means. When the temperature of the pressure oil supplied to the hydraulic actuator detected by the temperature detecting means rises, the tilt angle of the variable displacement hydraulic pump is reduced by the control of the regulator and the deceleration control means by the control processing means, and The deceleration control by the deceleration control means is more relaxed than before.

  By reducing the tilt angle of the variable displacement hydraulic pump, the flow rate supplied from this variable displacement hydraulic pump to the hydraulic actuator is reduced more than before. In addition, since the deceleration control by the deceleration control means is relaxed, the flow resistance of the deceleration control means to the pressure oil becomes smaller than before, and the heat generating action of the pressure oil is suppressed. Accordingly, the deceleration control of the hydraulic actuator can be performed while suppressing an increase in the temperature of the pressure oil supplied to the hydraulic actuator. Further, such control is configured by an oil temperature detecting means and a controller without requiring a complicated drive circuit configuration such as a control means for reducing the engine speed and a control means for reducing the pump output. This can be realized with a simple configuration by simply providing the obtained control processing means.

  The actuator speed control device for a work machine according to the present invention is the above-described invention, wherein the control processing means includes a controller, and the controller includes an input unit for inputting a signal from the oil temperature detection means, and the deceleration unit. A storage unit that preliminarily stores, as a threshold value, the temperature of pressure oil that defines a control start time at which deceleration control by the control unit is more relaxed, and a signal from the oil temperature detection unit that is input via the input unit Based on the threshold value determining means for determining whether the temperature detected by the oil temperature detecting means is equal to or higher than the threshold value stored in the storage unit, and the temperature detected by the oil temperature detecting means is A first process for reducing the tilt angle of the variable displacement hydraulic pump to the regulator when the threshold value is determined to be equal to or greater than the threshold value, and the deceleration control; A calculation unit that performs a second process for relaxing deceleration control by the stage more than before, a control signal corresponding to the first process in the calculation unit is output to the regulator, and a control signal corresponding to the second process is output. And an output unit for outputting to the deceleration control means.

  The present invention configured as described above is supplied to the hydraulic actuator detected by the oil temperature detecting means and input to the input unit of the controller when the deceleration control of the hydraulic actuator is being performed in a high temperature working environment. When the threshold value determination means of the calculation unit determines that the temperature of the pressure oil is equal to or higher than the threshold value stored in the storage unit, the first process of reducing the tilt angle of the variable displacement hydraulic pump by this calculation unit And the 2nd process which relaxes the deceleration control by a deceleration control means from before is performed, and the control signal according to each process result is output to a regulator and a deceleration control means from an output part. Thereby, deceleration control of the hydraulic actuator can be performed while the temperature of the pressure oil supplied to the hydraulic actuator is kept below the threshold value.

  In the actuator speed control device for a work machine according to the present invention, in the above invention, the deceleration control means is disposed between the control valve and the hydraulic actuator, and is output from the output unit of the controller. The oil temperature detecting means comprises an oil temperature sensor for detecting the temperature of the pressure oil flowing through a pipe line connecting the control valve and the hydraulic actuator. Yes.

  According to the present invention configured as described above, when the temperature of the pressure oil supplied to the hydraulic actuator detected by the oil temperature sensor and input to the input unit of the controller is equal to or higher than the threshold value, the calculation unit tilts the variable displacement hydraulic pump. A first process for reducing the angle and a second process for changing the deceleration control valve from a small opening amount to a large opening amount are performed, and control signals corresponding to the respective processing results Is output from the output unit to the regulator and the deceleration control valve.

  Also, the actuator speed control device for a work machine according to the present invention is the above-described invention, wherein the work machine is a traveling body, and the engine, the variable displacement hydraulic pump, the regulator, and the control are arranged on the traveling body. A revolving body on which the valve is mounted; a front work machine attached to the revolving body for performing work; and drive detection means for detecting that the front work machine is driven, and the controller The calculation unit includes drive determination means for determining whether or not the front work machine has been driven based on a signal output from the drive detection means, and determines that the front work machine has been driven by the drive determination means. When the temperature detected by the oil temperature detecting means is determined to be greater than or equal to the threshold value by the threshold value determining means, the first process and the second process are performed. It is characterized in that it is performed.

  The present invention configured as described above includes a first process for reducing a tilt angle of the variable displacement hydraulic pump by a calculation unit of the controller only during work performed by driving the front work machine, and The second process for relaxing the deceleration control by the deceleration control means more than before is performed, and the deceleration control performed by reducing the supply flow rate of the hydraulic actuator that drives the front work machine can be performed.

  The present invention provides an oil temperature detecting means for detecting the temperature of the pressure oil supplied to the hydraulic actuator, and the regulator is connected to the variable displacement hydraulic pump according to the increase in the temperature of the pressure oil detected by the oil temperature detecting means. Since the control processing means for controlling the deceleration control means so as to control the turning angle to be reduced and also to reduce the deceleration control more than before, it is supplied to the hydraulic actuator that is executing the deceleration control. The temperature rise of the pressure oil can be suppressed with a relatively simple configuration. This makes it possible to work with work machines in high-temperature work environments such as in tropical areas without causing damage to hydraulic equipment including hydraulic actuators due to increased pressure oil pressure, and without increasing production costs. And can ensure excellent practicality.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out an actuator speed control device for a work machine according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a side view showing a hydraulic excavator cited as an example of a working machine provided with an embodiment of an actuator speed control device according to the present invention.

  As shown in FIG. 1, the excavator includes a traveling body 1, a revolving body 2 disposed on the traveling body 1, and a front work machine 3 that is attached to the revolving body 2 and performs excavation work of earth and sand. And. On the revolving structure 2, a cab 4 is disposed at the front position, and a counterweight 5 is disposed at the rear position to ensure a weight balance. An engine room 6 is disposed between the cab 4 and the counterweight 5. The front work machine 3 is attached to the tip of the boom 7 which is attached to the swing body 2 so as to be rotatable in the vertical direction, the arm 8 which is attached to the tip of the boom 7 and is rotatable in the vertical direction. And a bucket 9 that is rotatable in the vertical direction. Further, a boom cylinder 10 that drives the boom 7, an arm cylinder 11 that drives the arm 8, and a bucket cylinder 12 that drives the bucket 9 are included.

  FIG. 2 is a hydraulic circuit diagram showing the configuration of the present embodiment provided in the hydraulic excavator shown in FIG. 1, and FIG. 3 is a block diagram showing the main part of FIG.

  As shown in FIG. 2, the actuator speed control apparatus according to the present embodiment includes an engine 20 disposed in the engine compartment 6, a variable displacement hydraulic pump 21 driven by the engine 20, and a tilt of the variable displacement hydraulic pump 21. And a regulator 22 for controlling the turning angle. In addition, a hydraulic actuator 23 that is actuated by pressure oil discharged from the variable displacement hydraulic pump 21 when performing work is provided. For example, the hydraulic actuator 23 is illustrated in a simplified manner for ease of explanation, but includes the boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12 described above. Operate.

  A control valve 24 that controls the flow of pressure oil supplied from the variable displacement hydraulic pump 21 to the hydraulic actuator 23 is disposed between the variable displacement hydraulic pump 21 and the hydraulic actuator 23. The control valve 24 is also shown in a simplified manner, similar to the hydraulic actuator 23 described above, but the direction control valve for controlling the boom cylinder 10, the direction control valve for controlling the arm cylinder 11, and the direction control for controlling the bucket cylinder 12. Includes a valve. Further, in the pipelines 30 and 31 positioned between the control valve 24 and the hydraulic actuator 23, the flow rate of the pressure oil supplied to the hydraulic actuator 23 is given priority over the control of the hydraulic actuator 23 by the control valve 20. Limiting control means for limiting and controlling the operating speed of the hydraulic actuator 23, for example, deceleration control valves 25 and 26 with variable opening amounts are arranged.

  Further, the actuator speed control device according to the present embodiment includes oil temperature detection means for detecting the temperature of the pressure oil supplied to the hydraulic actuator 23, for example, pipes 30 and 31 that connect the control valve 24 and the hydraulic actuator 23. Oil temperature sensors 27 and 28 for detecting the temperature of the flowing pressure oil are provided. Further, the regulator 22 is controlled so that the tilt angle of the variable displacement hydraulic pump 21 is reduced in accordance with the rise in the temperature of the pressure oil detected by the oil temperature sensors 27 and 28, and the deceleration control valves 25 and 26 are also combined. Control processing means, for example, a controller 29 is provided to control the deceleration control by the control so as to ease more than before.

  Although not shown, the present embodiment also includes drive detection means for detecting that the front work machine 3 has been driven. This drive detection means is comprised by the pressure sensor which detects the pilot pressure which switches each direction control valve contained in the control valve 24 which controls the boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12, for example.

  As shown in FIG. 3, the controller 29 defines an input unit 29 a for inputting signals from the oil temperature sensors 27 and 28 and a control start time point at which the deceleration control by the deceleration control valves 25 and 26 is more relaxed than before. And a storage unit 29b that stores in advance the temperature of the pressure oil to be stored as the threshold value A. The threshold A is set to 90 ° C., for example. Further, on the basis of a signal output from the drive detection unit including the pressure sensor described above, a drive determination unit that determines whether or not the front work machine 3 has been driven, and an oil temperature sensor 27 that is input via the input unit 29a, And a threshold judgment means for judging whether or not the temperature detected by these oil temperature sensors 27 and 28 is equal to or higher than the threshold A stored in the storage unit 29b based on the signal of 28. A first process for determining that the front work machine 3 has been driven and, at the same time, determining that the tilt angle of the variable displacement hydraulic pump 21 by the regulator 22 is smaller than the threshold A when the threshold determination means determines that the threshold A or greater; And an arithmetic unit 29c that performs a second process for relaxing the deceleration control by the deceleration control valves 25 and 26 more than before. Furthermore, an output unit 29d that outputs a control signal according to the first process in the arithmetic unit 29c to the regulator 22 and outputs a control signal according to the second process to the deceleration control valves 25 and 26 is provided.

  When the excavator including the present embodiment configured as described above is disposed in an area where the environmental temperature is not so high and excavation work for driving the front work machine 3 is performed, the switching operation of the control valve 24 is performed. Accordingly, the hydraulic oil discharged from the variable displacement hydraulic pump 21 driven by the engine 20 passes through the control valve 24 and the deceleration control valve 25 or 26 whose opening amount is maintained at the maximum, for example, the hydraulic actuator 23. To be supplied. As a result, the hydraulic actuator 23, that is, the corresponding one of the boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12 shown in FIG. 1 operates, and the boom 7, the arm 8, or the bucket 9 rotates in the vertical direction. Excavation work is carried out.

  During such work, for example, when the hydraulic actuator reaches the vicinity of the stroke end, a control signal is given from the controller 29 to the deceleration control valve 25 or 26, and the deceleration control valve 25 or 26 becomes squeezed, and the opening amount is reduced. It is controlled to be smaller. As a result, the flow rate supplied to the hydraulic actuator 23 decreases, the operating speed of the hydraulic actuator 23 decreases, and the hydraulic actuator 23 decelerates. Further, when the hydraulic actuator 23 reaches the stroke end, for example, the deceleration control valve 25 or 26 is completely closed, the supply of the flow rate to the hydraulic actuator 23 is blocked, and the hydraulic actuator 23 stops. Such control can prevent a shock when the hydraulic actuator 23 is stopped. In addition to the deceleration control near the stroke end as described above, for example, when the operation speed of the hydraulic actuator 23 is slowed down and the front work machine 3 is to be finely operated, or held by the front work machine 3. The deceleration control described above is also performed when it is desired to perform the positioning operation of the processed object.

  When the front work machine 3 is driven as described above, a signal from a pressure sensor (not shown) that detects a pilot pressure that switches the control valve 24 that controls the hydraulic actuator 23 is input to the input unit 29a of the controller 29, and the calculation is performed. It is determined that the front work machine 3 has been driven by the drive determination means provided in the section 29c. Further, the temperature of the pressure oil flowing through the pipelines 30 and 31 connecting the control valve 24 and the hydraulic actuator 23 is detected by the temperature sensor 27 or 28, input to the input unit 29a of the controller 29, and read into the calculation unit 29c. It is. It is determined whether or not the input oil temperature is equal to or higher than the threshold A stored in the storage unit 29b by the threshold determination means provided in the calculation unit 29c. However, in a normal working environment that is not a high temperature environment, the oil temperature detected by the oil temperature sensor 27 or 28 is rarely equal to or higher than the threshold A, that is, 90 ° C. or higher. That is, excavation work or the like in a normal work environment by the front work machine 3 as described above can be realized without causing any trouble.

  Unlike the normal working environment described above, when the hydraulic excavator is placed in a high temperature working environment such as a tropical region and excavation work or the like is performed by the front work machine 3, the control valve 24 and the hydraulic actuator are used. The oil temperature of the pressure oil flowing through the pipe line 30 or 31 connecting 23 is basically likely to be high. Under such circumstances, when the pipe line 30 or 31 is throttled by the deceleration control valve 25 or 26, the flow resistance against the pressure oil flowing through the pipe line 30 or 31 increases, and heat is generated. The oil temperature rises.

  FIG. 4 is a diagram showing a tilt angle-discharge pressure characteristic executed in the present embodiment, and FIG. 5 is a diagram showing a hydraulic actuator supply pressure oil temperature-deceleration control valve opening amount characteristic executed in the present embodiment.

  As the front work machine 3 is driven, it is output from the oil temperature sensor 27 or 28 in a state where it is determined that the front work machine 3 is driven by the drive determination means provided in the calculation unit 29c of the controller 29. If the oil temperature input to the input unit 29a of the controller 29 and read into the calculation unit 29c is determined to be equal to or higher than the threshold value A by the threshold value determination means of the storage unit 29c, the calculation unit 29c has been used so far. FIG. 4 shows a process of changing the tilt angle-discharge pressure characteristic M during normal operation to the tilt angle-discharge pressure characteristic N shown in FIG. 4, that is, the variable displacement hydraulic pump 21 controlled by the regulator 22. A first process for making the tilt angle smaller than before is performed. The tilt angle-discharge pressure characteristics M and N shown in FIG. 4 are stored in advance in the storage unit 29b.

  In addition to the above-described control for reducing the tilt angle, as shown in FIG. 5, the control for changing the opening amount of the deceleration control valve 25 or 26 to an opening amount D corresponding to the threshold value A or more is changed to open. That is, the second process for relaxing the deceleration control by the deceleration control valve 25 or 26 more than before is also performed. This second process is continued until the oil temperature drops to B slightly lower than the threshold A. While the oil temperature decreases from the threshold value A to B, for example, the opening amount of the deceleration control valve 25 or 26 is maintained at D. When it is detected that the oil temperature has decreased to B, the control shifts again from the characteristic N in FIG. 5 to the deceleration control of the deceleration control valve 25 or 26 by the normal characteristic M.

  As described above, after the first process and the second process in the calculation unit 29c, a control signal corresponding to the first process of the calculation unit 29c is output from the output unit 29d of the controller 29 to the regulator 22, and according to the second process. The control signal is output to the deceleration control valve 25 or 26.

  As described above, according to the present embodiment, the regulator 22 is controlled in accordance with the first process performed by the calculation unit 29c of the controller 29, and the tilt angle of the variable displacement hydraulic pump 21 is reduced. The flow rate supplied from the pump 21 to the hydraulic actuator 23 is smaller than before. Further, the deceleration control valve 25 or 26 is controlled according to the second process performed by the calculation unit 29c, and the deceleration control valve 25 or 26 becomes more open than before, and these deceleration control valve 25 or 26 The flow resistance with respect to the pressure oil 26 is smaller than before, and the exothermic action of the pressure oil is suppressed. Accordingly, it is possible to realize the deceleration control of the hydraulic actuator 23 while suppressing an increase in the temperature of the pressure oil supplied to the hydraulic actuator 23.

  Therefore, the work by the front working machine 3 of the hydraulic excavator in a high-temperature work environment such as a tropical region can be realized without causing damage to the hydraulic equipment including the hydraulic actuator 23 due to the temperature rise of the pressure oil. Further, the oil temperature sensors 27 and 28 do not require a complicated drive circuit configuration such as providing a control means for reducing the engine speed, a control means for reducing the pump output, etc. for the deceleration control of the hydraulic actuator 23 described above. Therefore, it can be realized with a simple configuration simply by providing the control processing means including the controller 29, and therefore, the manufacturing cost is not increased. With these, excellent practicality can be secured.

1 is a side view showing a hydraulic excavator cited as an example of a work machine provided with an embodiment of an actuator speed control device according to the present invention. It is a hydraulic circuit diagram which shows the structure of this embodiment with which the hydraulic excavator shown by FIG. 1 is equipped. It is a block diagram which shows the principal part of FIG. It is a figure which shows the tilt angle-discharge pressure characteristic performed in this embodiment. It is a figure which shows the hydraulic actuator supply pressure oil temperature-deceleration control valve opening amount characteristic performed by this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling body 2 Revolving body 3 Front work machine 4 Operation room 5 Counterweight 6 Engine room 7 Boom 8 Arm 9 Bucket 10 Boom cylinder (hydraulic actuator)
11 Arm cylinder (hydraulic actuator)
12 Bucket cylinder (hydraulic actuator)
20 Engine 21 Variable displacement hydraulic pump 22 Regulator 23 Hydraulic actuator 24 Control valve 25 Deceleration control valve (deceleration control means)
26 Deceleration control valve (deceleration control means)
27 Oil temperature sensor (oil temperature detection means)
28 Oil temperature sensor (oil temperature detection means)
29 controller (control processing means)
29a Input unit 29b Storage unit 29c Operation unit 29d Output unit 30 Pipe line 31 Pipe line

Claims (4)

An engine, a variable displacement hydraulic pump driven by the engine, a regulator that controls a tilt angle of the variable displacement hydraulic pump, and a hydraulic actuator that is operated by pressure oil discharged from the variable displacement hydraulic pump when performing work , Provided in a work machine having a control valve for controlling the flow of pressure oil supplied from the variable displacement hydraulic pump to the hydraulic actuator,
In an actuator speed control device for a work machine provided with a deceleration control means for limiting the flow rate of pressure oil supplied to the hydraulic actuator and performing deceleration control of the operating speed of the hydraulic actuator,
Oil temperature detecting means for detecting the temperature of the pressure oil supplied to the hydraulic actuator;
The regulator is controlled so that the tilt angle of the variable displacement hydraulic pump becomes smaller in accordance with the increase in the temperature of the pressure oil detected by the oil temperature detecting means, and the deceleration control is further relaxed than before. An actuator speed control device for a work machine, comprising: a control processing means for controlling the deceleration control means. The actuator speed control device for a work machine according to claim 1,
The control processing means comprises a controller,
This controller
An input unit for inputting a signal from the oil temperature detecting means;
A storage unit that preliminarily stores, as a threshold value, the temperature of the pressure oil that defines the start point of control for relaxing the deceleration control by the deceleration control unit more than before;
Based on the signal of the oil temperature detection means input via the input unit, a threshold determination for determining whether or not the temperature detected by the oil temperature detection means is equal to or higher than the threshold stored in the storage unit. A first pressure reduction means for reducing the tilt angle of the variable displacement hydraulic pump to the regulator when the temperature detected by the oil temperature detection means is greater than or equal to the threshold value by the threshold value determination means. A calculation unit for performing a process and a second process for relaxing the deceleration control by the deceleration control unit more than before;
An output unit that outputs a control signal according to the first process in the arithmetic unit to the regulator and outputs a control signal according to the second process to the deceleration control unit. Actuator speed control device. The actuator speed control device for a work machine according to claim 2,
The deceleration control means is arranged between the control valve and the hydraulic actuator, and includes a deceleration control valve that operates according to a control signal output from the output unit of the controller.
The actuator speed control device for a working machine, wherein the oil temperature detecting means comprises an oil temperature sensor for detecting a temperature of pressure oil flowing through a pipe line connecting the control valve and the hydraulic actuator. The actuator speed control device for a work machine according to claim 2 or 3,
The work machine is
A traveling body, a revolving body disposed on the traveling body and mounted with the engine, the variable displacement hydraulic pump, the regulator, and the control valve; and a front work machine attached to the revolving body and performing work. Have
Drive detection means for detecting that the front work machine is driven,
The calculation unit of the controller includes drive determination means for determining whether the front work machine is driven based on a signal output from the drive detection means, and the front work machine is driven by the drive determination means. And when the temperature detected by the oil temperature detecting means is determined to be greater than or equal to the threshold value by the threshold value determining means, the first process and the second process are performed. Actuator speed control device.

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