JPH11125205A - Hydraulic drive device for hydraulic working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic drive device for a hydraulic working machine wherein the displacement volume of a pump can be varied and the driving operation of an actuator can be realized even in the case of the occurrence of a failure in a control system for controlling a regulator. SOLUTION: This hydraulic drive device controls a pump 2 so as to increase the displacement volume of the pump 2 according to the increase of a pump tilt rotation control signal for driving the regulator 5 of a variable displacement hydraulic pump 2, and the pump tilt rotation control signal is composed of an ordinary control signal corresponding to an ordinary operation for operating the arm cylinder 7 and a specific control signal corresponding to a specific operation for operating a breaker 50, which make mutually different in the upper limit value of the displacement volume of the pump 2 for enabling the driving operation of actuators for an arm cylinder 7 and the breaker 50. The device is moreover equipped with an electromagnetic proportional valve 15 which outputs the specific control signal during driving and the ordinary control signal during nondriving and a switch 17 for driving the valve 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drive for a hydraulic working machine such as a hydraulic shovel, and more particularly to a hydraulic drive for a hydraulic working machine capable of changing an upper limit of a displacement of a variable displacement hydraulic pump.

[0002]

2. Description of the Related Art A regulator for controlling the displacement of a variable displacement hydraulic pump is provided, and the displacement of the variable displacement hydraulic pump is increased in accordance with an increase in the value of a pump displacement control signal for driving the regulator. 2. Description of the Related Art As a hydraulic drive device for controlling a displacement hydraulic pump, a hydraulic drive device disclosed in Japanese Patent No. 2534897 is conventionally known. In the first prior art, the displacement, that is, the displacement of the pump is controlled in accordance with the operation amount of the pilot operation device.

However, in the first prior art, since the maximum displacement of the variable displacement hydraulic pump is not changed as required, an actuator driven by pressure oil discharged from the variable displacement hydraulic pump is not provided. It was not suitable for all of a plurality of different operations performed via the. That is, if an operation that is frequently performed is referred to as a normal operation, in an operation different from the normal operation, that is, in a specific operation that is performed less frequently than the normal operation, for example, the actuator speed is set to be lower than that in the normal operation. However, even when such a specific operation is performed, there is a problem that the upper limit value of the displacement of the variable displacement hydraulic pump is the same as that in the normal operation, and therefore, the operator lowers the actuator speed. Therefore, the lever of the pilot operating device was set to a half stroke to cope with the problem.

In order to solve such a problem, a second prior art disclosed in, for example, Japanese Patent Application Laid-Open No. 8-219104 has been proposed. This second conventional technique controls the tilting of a variable displacement hydraulic pump by an electromagnetic proportional pressure reducing valve controlled by a controller. That is, the second prior art includes a regulator constituted by an electromagnetic proportional pressure reducing valve. The upper limit value of the displacement of the variable displacement hydraulic pump can be changed in accordance with the signal given, and therefore the maximum speed of the actuator can be changed in accordance with the type of operation.

[0005]

However, there is a problem in the above-mentioned second prior art. In the second conventional technique, a failure of an electric signal system for controlling a regulator such as a failure of a controller or a failure of a wiring connecting a controller to an electromagnetic proportional pressure reducing valve occurs, and the drive control of the electromagnetic proportional pressure reducing valve becomes impossible. , The tilt of the variable displacement hydraulic pump is kept at the minimum tilt amount in the second conventional technique. Therefore, the flow rate supplied to the actuator becomes the minimum flow rate, and the actuator cannot be moved, and there is a concern that a situation may occur in which the operation that has been performed so far cannot be continued or performed.

For example, when the target hydraulic working machine is a hydraulic excavator, the front of a boom, an arm, a bucket, or the like is rotated, and a place easily subject to restrictions such as a turning radius or a maximum height position of the boom or the arm. During normal operation such as excavation work, for example, when the failure of the electric signal system controlling the above-mentioned regulator occurs, the front stops moving in the excavation posture, or the excavator is moved to a predetermined position. The excavator may not be able to run to the point where the evacuation may occur, causing a great deal of inconvenience to the surrounding environment where the excavator is located, or taking time to transport the excavator for repair. As a result, the efficiency of the excavation operation being performed may be significantly reduced.

The present invention has been made in view of the above-mentioned situation in the related art, and has as its object to change the displacement of a variable displacement hydraulic pump and to cause a failure in a control system for controlling a regulator. When
An object of the present invention is to provide a hydraulic drive device of a hydraulic working machine that can realize a driving operation of an actuator.

[0008]

In order to achieve the above object, according to a first aspect of the present invention, there is provided a motor, a variable displacement hydraulic pump driven by the prime mover, and discharge from the variable displacement hydraulic pump. An actuator driven by pressure oil, a directional control valve for controlling the flow of pressure oil supplied from the variable displacement hydraulic pump to the actuator, and a regulator for controlling a displacement of the variable displacement hydraulic pump. A hydraulic drive device for a hydraulic working machine that controls a variable displacement hydraulic pump so as to increase a displacement of the variable displacement hydraulic pump in accordance with an increase in a value of a pump displacement control signal that drives a regulator. As a control signal, the displacement of the variable displacement hydraulic pump, which enables the drive operation of the actuator, A plurality of tilt control signals for making the values different from each other are set, and at the time of driving, a tilt control signal other than a predetermined one of the plurality of tilt control signals is output, and a non-drive signal is output. Sometimes, the predetermined 1
Variable tilt control means for outputting two tilt control signals, and drive control means for outputting a predetermined drive signal for driving the variable tilt control means.

According to the first aspect of the present invention, in addition to the regulator for controlling the displacement of the variable displacement hydraulic pump, a variable displacement control means for controlling the regulator is provided. The tilt control means operates according to a drive signal output from the drive control means.

When a predetermined drive signal is output from the drive control means to the variable tilt control means, that is, when the variable tilt control means is driven, the tilt control signal excluding one predetermined tilt control signal is supplied to the regulator. , The upper limit of the displacement of the variable displacement hydraulic pump is appropriately controlled, and the actuator can be driven by the pressure oil discharged from the variable displacement hydraulic pump.

When a predetermined drive signal is not output from the drive control means to the variable tilt control means, that is, when the variable tilt control means is not driven, one predetermined tilt control signal is supplied to the regulator. In contrast, the upper limit of the displacement of the variable displacement hydraulic pump is controlled as compared with the above case, and the actuator can be driven by the pressure oil discharged from the variable displacement hydraulic pump.

If the electric system for controlling the regulator fails when the tilt variable control means is driven or not driven as described above, that is, when the drive control means fails, When a failure occurs in the connection system between the drive control means and the variable tilt control means and the like, and the control of the variable tilt control means becomes impossible,
It is possible to output the above-mentioned predetermined one tilt control signal from the tilt variable control means.
The actuator can be driven by two tilt control signals.

According to a second aspect of the present invention, in accordance with the first aspect of the present invention, the plurality of tilt control signals execute a high-frequency normal operation performed by the hydraulic working machine. The configuration includes a normal control signal to be performed and at least one specific control signal for performing a specific operation that is performed less frequently on the hydraulic working machine than the normal operation.

According to the second aspect of the present invention, when a failure occurs in the control system for controlling the regulator when the variable tilt control means is driven or not driven, that is, when the above-mentioned drive control means is used. Or when a failure occurs in the connection system between the drive control means and the variable tilt control means and the control of the variable tilt control means becomes impossible, When the rotation control signal is a normal control signal, the normal control signal is output from the tilt variable control means to the regulator, and when the predetermined one tilt control signal is a specific control signal, A specific control signal is output from the variable tilt control means to the regulator.

According to a third aspect of the present invention, in the second aspect of the present invention, the displacement of the variable displacement hydraulic pump is smaller than that in the case where the specific control signal is the normal control signal. , And the predetermined one tilt control signal is composed of the normal control signal.

According to the third aspect of the present invention, when the operation performed by the hydraulic working machine is a normal operation, a predetermined drive signal is not output from, for example, the drive control means. The variable control means is kept in an operation mode in which the input pump displacement control signal is output as it is as a normal control signal. Along with this, the regulator is activated by the normal control signal, the upper limit of the displacement of the variable displacement hydraulic pump is kept at a large upper limit suitable for normal operation, and the upper limit of the displacement is discharged from the variable displacement hydraulic pump controlled in this way. The desired normal operation can be performed by driving the actuator with the pressurized oil.

When the operation performed by the hydraulic working machine is a specific operation to be performed at an actuator speed lower than the actuator speed during normal operation, a predetermined drive signal is output from the drive control means. As a result, the variable tilt control means operates, and the variable tilt control means changes the specific value of the input pump tilt control signal to a small value, that is, a specific control signal having characteristics different from those of the normal control signal. The signal is output as a signal for driving the regulator. This activates the regulator,
The upper limit value of the displacement of the variable displacement hydraulic pump is controlled so as to be a smaller value than that of the normal control signal described above, that is, an upper limit value suitable for the corresponding specific operation.
Therefore, the maximum flow rate discharged from the variable displacement hydraulic pump is smaller than that in the normal operation, and the flow rate is supplied to the actuator, so that the corresponding specific operation can be performed well.

If a failure occurs in the control system for controlling the regulator while the specific operation is being performed or the above-described normal operation is being performed, the above-described drive control is performed. The failure of the means or the failure of the connection system between the drive control means and the variable tilt control means occurs, and the predetermined variable drive signal is not supplied to the variable tilt control means. When a situation occurs in which tilting cannot be performed, a normal control signal can be output from the tilt variable control means, and thus the normal operation described above can be performed. In this case, if the stroke of the direction control valve is controlled to a half stroke, the corresponding actuator can be driven to perform the above-described specific operation.

According to a fourth aspect of the present invention, in the second aspect of the present invention, the displacement of the variable displacement hydraulic pump is smaller than that in the case where the specific control signal is the normal control signal. , And the predetermined one tilt control signal is composed of the specific control signal.

According to the fourth aspect of the present invention, when the operation performed by the hydraulic working machine is a specific operation, a predetermined drive signal is not output from, for example, the drive control means, thereby causing the tilting operation. The variable control means is kept in an operation mode in which the input pump displacement control signal is output as a specific control signal as it is. Along with this, the regulator is operated by the specific control signal, the upper limit of the displacement of the variable displacement hydraulic pump is kept at a large upper limit suitable for the specific operation, and the upper limit of the displacement is discharged from the variable displacement hydraulic pump controlled in this way. The actuator can be driven by the pressurized oil to perform a desired specific operation.

When the operation to be performed by the hydraulic working machine is a normal operation to be performed at an actuator speed lower than the actuator speed at the time of the specific operation, the drive control means outputs a predetermined drive signal. As a result, the variable tilt control means operates, and the variable tilt control means changes the value of the input pump tilt control signal to a small value, that is, the normal control signal having a characteristic different from that of the specific control signal. The signal is output as a signal for driving the regulator. This activates the regulator,
The upper limit of the displacement of the variable displacement hydraulic pump is controlled so as to be smaller than that of the specific control signal described above, that is, the upper limit suitable for the corresponding normal operation.
Therefore, the maximum flow rate discharged from the variable displacement hydraulic pump is smaller than that at the time of the specific operation, and the flow rate is supplied to the actuator, so that the corresponding normal operation can be satisfactorily performed.

When a failure occurs in the control system for controlling the regulator when the normal operation is being performed or when the above-described specific operation is being performed, the above-described drive control is performed. The failure of the means or the failure of the connection system between the drive control means and the variable tilt control means occurs, and the predetermined variable drive signal is not supplied to the variable tilt control means. When a situation occurs in which tilting cannot be performed, a specific control signal can be output from the tilt variable control means. Therefore, the corresponding actuator can be driven to perform the above-described specific operation. In this case, if the stroke of the direction control valve is controlled to a half stroke, the corresponding actuator can be driven to perform the above-described normal operation.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the drive control means includes a table storing characteristics of the specific control signal and the normal control signal. It has at least one of the tables for storing the characteristics of the control signals, and includes a controller for outputting a predetermined drive signal corresponding to the characteristics stored in the table to the tilt variable control means.

According to the fifth aspect of the present invention, the type of operation performed by the hydraulic working machine, the normal operation, or the specific operation is stored in a corresponding table of the controller. A predetermined drive signal corresponding to the characteristic of the control signal is output from the controller, and the tilt variable control means can be operated according to the predetermined drive signal.

According to a sixth aspect of the present invention, in the first aspect of the present invention, there is provided an operating device for outputting an operating signal for controlling switching of the directional control valve. The pump displacement control signal for driving the regulator is constituted by the operation signal.

Further, the invention according to claim 7 of the present invention provides:
In the invention according to any one of claims 1 to 5,
The directional control valve has a center bypass passage, and the pump tilt control signal for driving the regulator changes its value in relation to a change in the flow rate of the center bypass passage. It is.

According to the sixth and seventh aspects of the present invention, the displacement of the variable displacement hydraulic pump can be controlled in accordance with the amount of operation of the operating device.

The invention according to claim 8 of the present invention is the invention according to any one of claims 1 to 7, wherein the regulator comprises a pilot type regulator operated by a pressure signal, and The control signal is a pressure signal, and the tilt variable control means comprises an electromagnetic valve.

In the invention according to claim 8 configured as described above, when a predetermined drive signal is given to the solenoid valve, the solenoid valve is switched, and the value of the input pressure signal is changed and output to the regulator. I do.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hydraulic drive device for a hydraulic working machine according to the present invention will be described below with reference to the drawings. FIGS. 1 to 3 are explanatory diagrams of a first embodiment of a hydraulic drive device for a hydraulic working machine according to the invention according to claims 1, 2, 3, 6, and 8, and FIG. FIG. 2 is a hydraulic circuit diagram showing a configuration of the first embodiment, and FIG. 2 is a relation between a signal pressure applied to a regulator provided in the first embodiment shown in FIG. 1 and a displacement amount of a variable displacement hydraulic pump, that is, a displacement. FIG. 3 shows the relationship between the primary pressure on the input side and the secondary pressure on the output side of the solenoid valve provided in the first embodiment shown in FIG. 1, for example, the solenoid proportional valve. FIG.

The first embodiment shown in FIG. 1 is provided, for example, in a hydraulic shovel, and includes a prime mover 1, a variable displacement hydraulic pump 2 and a pilot pump 3 driven by the prime mover 1, and a variable displacement hydraulic pump. 2 includes a main relief valve 4 that regulates the discharge pressure of the pump 2 and a pilot relief valve 4a that regulates the discharge pressure of the pilot pump 3; and a regulator 5 that controls the amount of displacement of the variable displacement hydraulic pump 2, that is, the displacement. . In addition to a plurality of actuators, for example, a swing motor 6 for driving a swing body in which a driver's cab of a hydraulic shovel is disposed, an arm cylinder 7 for driving an arm constituting a front, and an actuator for special work, for example, crushing of rock It has a breaker 50 used for Generally, hydraulic excavators include:
Although other actuators such as a boom cylinder, a bucket cylinder, and a left and right traveling motor are also provided, these actuators are not shown for the sake of simplicity.

A directional control valve for controlling the flow of hydraulic oil supplied from the variable displacement hydraulic pump 2 to each of the swing motor 6, the arm cylinder 7, and the breaker 50, that is, a swing direction control valve 9, an arm direction control A valve 10, a directional control valve 11 for a breaker, and an operating signal for switching and controlling each of these directional control valves 9 to 11, for example, an operating device for generating a pilot pressure signal, that is, a turning pilot valve 12, an arm pilot valve 13, A breaker pilot valve 14 and a tank 70 are provided.

Further, a pilot line 19 is provided which extracts the maximum pressure from the pilot pressure signals generated by the pilot valves 12 to 14 and guides it as a pump tilt control signal for driving the regulator 5.

The upper limit value of the displacement of the variable displacement hydraulic pump 2 which enables the operation of the actuator such as the arm cylinder 7 and the breaker 50 described above is made different from each other as the pump tilt signal given to the regulator 5. A plurality of tilt control signals are set.

The operation frequently performed by the excavator is called a normal operation. The normal operation is a driving operation of the arm cylinder 7 for controlling the front during excavation work. The operation performed less frequently by the excavator is called a specific operation, and this specific operation is, for example, a driving operation of the breaker 50.

The plurality of tilt control signals described above include a normal control signal for performing the above-described normal operation and a specific control signal for performing the specific operation. This specific control signal has a characteristic of making the upper limit of the displacement of the variable displacement hydraulic pump smaller than, for example, the above-described normal control signal.

In the first embodiment, during driving, a tilt control signal excluding a predetermined one of a plurality of tilt control signals, that is, a normal control signal and a specific control signal, is output. A variable tilt control means for outputting the above-mentioned predetermined one tilt control signal when not being driven, for example, an electromagnetic proportional valve 15 which is one of electromagnetic valves.
It has. In the first embodiment, the predetermined one tilt control signal is, for example, the normal control signal described above.

When the above-mentioned electromagnetic proportional valve 15 is not driven, that is, when a predetermined drive signal is not given and is held at the upper position shown in FIG.
The pilot pressure signal (primary pressure P0), which is led through the controller, is output to the regulator 5 as it is as the secondary pressure P1 (= P0). When the drive is performed, that is, when a predetermined drive signal is given, the lower stage from the state of FIG. Direction, and the opening is changed so as to reduce the opening amount.
And changes the value of the pilot pressure signal (primary pressure P0), which is guided through the controller, and outputs a smaller pilot pressure signal (secondary pressure P1) to the regulator 5.

Further, there is provided a drive control means for outputting the above-mentioned predetermined drive signal, for example, a switch 17, for controlling the above-mentioned electromagnetic proportional valve 15 so as to maintain the above-mentioned operation form for outputting the above-mentioned specific control signal.

As described above, in the first embodiment, apart from the regulator 5 for controlling the displacement of the variable displacement hydraulic pump 2, the electromagnetic proportional valve 15 capable of controlling the regulator 5 is provided. The electromagnetic proportional valve 15 is controlled by a predetermined drive signal, that is, by the ON operation of the switch 17, so that the opening amount becomes a predetermined value smaller than the fully opened state.

In the first embodiment configured as described above,
When the operation performed by the hydraulic excavator is a normal operation that is empirically known, for example, when operating the arm cylinder 7 or the like for excavation work, a large flow rate is required due to the combined operation of these actuators. Is required, the switch 17 is kept open. Therefore, the electromagnetic proportional valve 15 is not switched, and is maintained at the upper position shown in FIG. In this state, when operating the actuator that drives the front of the arm cylinder 7 or the like by operating the arm pilot valve 13 or the like,
The maximum value of the pilot pressure generated by the arm pilot valve 13 and the like is guided to the pilot line 19 as a pilot pressure signal, and is input to the electromagnetic proportional valve 15 as the primary pressure P0. At this time, since the electromagnetic proportional valve 15 is fully opened, the primary pressure P0 is output to the regulator 5 as it is as the secondary pressure P1 as described above. As a result, the regulator 5 is operated, and the upper limit of the amount of displacement of the variable displacement hydraulic pump 2 is maintained at a relatively large upper limit suitable for the normal operation, and the relatively large maximum flow rate from the variable displacement hydraulic pump 2 is increased. It is discharged and a desired normal operation can be performed via an actuator such as the arm cylinder 7.

FIG. 2 shows the relationship between the signal pressure applied to the regulator 5, ie, the pilot pressure signal, and the displacement of the variable displacement hydraulic pump 2, ie, the displacement.
As the operation amount of the arm pilot valve 13 and the like increases, the value of the pilot pressure signal guided through the pilot line 19 increases, and the pump displacement increases to the maximum displacement (upper limit) so as to follow the pilot pressure signal. Then, a constant maximum flow rate is discharged at the upper limit value. 3 is a characteristic line showing the relationship between the primary pressure P0 during normal operation and the secondary pressure P1, that is, the normal control signal. In this normal operation, the secondary pressure P1 equal to the primary pressure P0 is reduced. The output is provided from the electromagnetic proportional valve 15.

When the operation to be performed by the hydraulic excavator is to be driven at a smaller flow rate as compared with the normal operation, for example, when the breaker 50 is driven, the switch 17 is turned on. . As a result, a predetermined drive signal is given to the drive unit of the electromagnetic proportional valve 15, and as described above, the electromagnetic proportional valve 15
When the operation of the breaker pilot valve 14 is increased, the electromagnetic proportional valve 15 is switched to the pilot line 19.
The pilot pressure signal (primary pressure P0), which is guided through the controller, is inputted, and the pilot pressure signal (secondary pressure P1) having a smaller value than the specific control signal, that is, the inputted pilot pressure signal (primary pressure P0). ) Is output to the regulator 5.

In FIG. 3, reference numeral 52 denotes a primary pressure P at the time of this specific operation.
0 is a characteristic line showing the relationship between the secondary pressure P1 and the specific control signal. At the time of this specific operation, when the pressure becomes equal to or higher than a predetermined pressure value, the constant secondary pressure P becomes smaller than the primary pressure P0.
1 is output.

In response to the secondary pressure P1, the regulator 5 operates, and the upper limit of the amount of displacement of the variable displacement hydraulic pump 2 becomes smaller than that of the normal control signal described above. 2 is smaller than that during normal operation,
It is possible to realize a desired drive operation of the breaker 50 in which the maximum operation speed of 0 is reduced.

When a failure occurs in the control system for controlling the regulator 5 when the specific operation is performed or the normal operation is performed as described above, Failure of the electromagnetic proportional valve 15, failure of the switch 17, disconnection of the wiring connecting the switch 17 and the electromagnetic proportional valve 15, and the like may occur.
5 is not supplied with a predetermined drive signal,
When a situation occurs in which the control of the solenoid valve becomes impossible, a normal control signal from the solenoid proportional valve 15, that is, a pilot pressure signal (primary pressure P
0) is led to the regulator 5 as it is,
The normal operation described above can be performed. In addition, even when a failure occurs in the control system for controlling the regulator 5 and a special situation occurs in which the regulator 5 is controlled by the normal control signal, the flow rate discharged from the variable displacement hydraulic pump 2 is suppressed. By performing the operation, for example, the operation amount of the breaker pilot valve 14 that controls the breaker directional control valve 11, that is, the lever stroke is set to a half stroke, so that the drive operation of the breaker 50 is performed as soon as possible. be able to.

According to the first embodiment configured as described above, the drive amount of the electromagnetic proportional valve 15 can be controlled to change the tilt amount of the variable displacement hydraulic pump 2, and the excavation work of earth and sand can be performed. It is possible to secure a desired actuator speed according to the type of actuator operation, such as an actuator operation to perform a rock crushing operation or the like. Also, when a failure occurs in the control system that controls the regulator 5, the normal operation of the arm cylinder 7 and the like for the front drive performed by the hydraulic shovel and the specific operation of driving the breaker 50 are performed. Can be done. Therefore, the operation can be continued or performed by operating the corresponding actuator, and a decrease in the operation efficiency can be prevented. Further, it is possible to easily change the work form of the excavator, such as changing the working posture of the excavator or moving the vehicle body from a stop position.

FIGS. 4 and 5 show the first, second, third and fourth embodiments of the present invention.
FIG. 4 is an explanatory view showing a second embodiment of a hydraulic drive device for a hydraulic working machine according to the inventions according to the fifth, sixth, and eighth aspects. FIG. 4 is a hydraulic circuit diagram showing a configuration of the second embodiment of the present invention. FIG. 5 is a block diagram showing a main configuration of a controller provided in the second embodiment shown in FIG.

In FIG. 4 showing the second embodiment, in place of the breaker 50, the breaker directional control valve 11, and the breaker pilot valve 14 shown in FIG. 8 is provided with a bucket directional control valve 11a for controlling the driving of the bucket 8 and a bucket pilot valve 14a for switching the bucket directional control valve 11a. Further, in the second embodiment, the drive control means for outputting a predetermined drive signal for operating the electromagnetic proportional valve 15 includes the controller 16 having the main configuration shown in FIG. 5 and the operation of the arm pilot valve 13. , A pressure detector 21 that outputs a detection signal to the controller 16 and a pilot pressure signal that is generated by a bucket cloud operation by the bucket pilot valve 14a. A pressure detector 18 that outputs a detection signal, and a pressure detector 22 that detects a pilot pressure signal generated by operation of the turning pilot valve 12 and outputs a detection signal to the controller 16 are provided. .

As shown in FIG. 5, the controller 16 has a table 101 for storing the characteristics of the normal control signal.
And a table 100 storing characteristics of the specific control signal;
The maximum value selecting means 103 which selects the maximum value of the signal corresponding to the pump maximum displacement output from the tables 101 and 100 and outputs the selected value as the pump maximum displacement target value, and the output from the maximum value selecting means 103. And a table 102 for storing the relationship between the pump maximum displacement target value and the electromagnetic proportional valve output current. The characteristics of the normal control signal stored in the above-described table 101 relate to, for example, the operation of the arm cylinder 7, and in the second embodiment, for example, the operation of the arm cylinder 7 is determined in advance as the normal operation. . In this table 101, a relationship is set in which the upper limit of the maximum displacement of the pump changes to 100% in accordance with an increase in the value of the detection signal output from the pressure detector 21. The characteristic of the specific control signal stored in the above-described table 100 relates to, for example, the cloud operation of the bucket cylinder 8,
In the embodiment, for example, the cloud operation of the bucket cylinder 8 is determined in advance as the specific operation. In this table 100, the upper limit of the maximum displacement of the pump is set to 90 according to the increase of the value of the detection signal output from the pressure detector 18.
A relationship that changes until the value reaches% is set.

Although the table relating to the operation of the swing motor 6 is not shown, the operation of the swing motor 6 is predetermined in advance as another specific operation, for example. As the value of the detection signal output from the pressure detector 22 increases, the upper limit of the maximum displacement becomes 70
% Is set, and the maximum displacement of the pump output from the table is configured to be input to the maximum value selecting means 103 shown in FIG.

The relationship between the pump maximum displacement target value and the electromagnetic proportional valve output current stored in the above-described table 102 is determined by the value of the electromagnetic proportional valve output current as the pump maximum displacement target value increases, ie, When the value of the predetermined drive signal output to the electromagnetic proportional valve 15 decreases and the upper limit value of the pump maximum displacement output from the maximum value selecting means 103 is 100%, the pump maximum displacement target value becomes maximum. At this time, the value of the electromagnetic proportional valve output current is set to 0, and the predetermined drive signal is set so as not to be output from the controller 16. Other configurations are the same as those of the first embodiment shown in FIG. 1 described above.

In the second embodiment configured as described above,
When the operation performed by the hydraulic excavator is a normal operation, for example, when operating the arm cylinder 7 or the like for excavation work, the pilot pressure signal generated by the operation of the arm pilot valve 13 detects the pressure. The pressure detector 21 outputs a detection signal to the controller 16. Based on this detection signal, the maximum pump displacement is obtained by the table 101 shown in FIG.
For example, if the lever of the arm pilot valve 13 is operated at full stroke, the maximum tilt of the pump is 10
It becomes the upper limit of 0%, and that value is output to the maximum value selecting means 103. The maximum value selecting means 103 outputs the maximum pump displacement of the upper limit of 100% to the table 102 as the maximum pump displacement target value. The output current of the electromagnetic proportional valve corresponding to the pump maximum displacement target value is obtained from this table 102. Since the current value is the maximum pump displacement target value corresponding to the maximum pump displacement of 100%, The value of the electromagnetic proportional valve output current is determined to be zero. Therefore, a predetermined drive signal is not output from the controller 16 to the electromagnetic proportional valve 15 shown in FIG. 4, and the electromagnetic proportional valve 15 is held at the maximum opening amount (fully opened state). At this time, as described in the first embodiment, the pilot line 1
The pilot pressure signal guided through 9 is output as it is as a normal control signal from the electromagnetic proportional valve 15 to the regulator 5. By operating the regulator 5, the upper limit of the amount of displacement of the variable displacement hydraulic pump 2 is suitable for this normal operation. The maximum maximum flow rate is discharged from the variable displacement hydraulic pump 2 while being kept at the upper limit of 100%, and a desired normal operation can be performed via an actuator such as the arm cylinder 7.

For example, when the bucket cloud is to be driven at a relatively high actuator speed, that is, a single operation of the bucket cloud, that is, a predetermined specific operation, although the flow rate is smaller than that of the normal operation, the pilot valve 14a for the bucket is operated. A pilot pressure signal generated by the bucket cloud operation is detected by the pressure detector 18, and a detection signal is output from the pressure detector 18 to the controller 16. Based on this detection signal, the pump maximum displacement is obtained by the table 100 shown in FIG. For example, if the full stroke operation of the lever of the packet pilot valve 14a is performed, the maximum pump displacement becomes the upper limit of 90%, and that value is output to the maximum value selector 103. The maximum value selecting means 103 sets the maximum pump displacement of the upper limit of 90% as the maximum pump displacement target value in the table 1.
02 is output. The electromagnetic proportional valve output current corresponding to the pump maximum displacement target value is obtained from the table 102, and a predetermined drive signal corresponding to the value of the electromagnetic proportional valve output current is output to the electromagnetic proportional valve 15. Thereby, the electromagnetic proportional valve 15
4 is changed from the state shown in FIG. 4 to the lower stage, and the opening is changed so as to be smaller. The electromagnetic proportional valve 15 receives a pilot pressure signal guided through the pilot line 19 and receives a smaller value. The pilot pressure signal is output to the regulator 5 as a specific control signal. In response to this specific control signal, the regulator 5 is operated, and the upper limit value of the amount of displacement of the variable displacement hydraulic pump 2 is suppressed to 90%.
A sufficient bucket operation speed that sufficiently satisfies the required flow rate can be secured, and the desired bucket cloud operation can be performed.

When the swing motor 6 is driven independently, the operation is the same as that of the bucket cloud operation described above.
A specific control signal corresponding to the upper limit value is output, and the swing motor 6 can be driven independently. The flow rate is suppressed, and the supply of useless flow rate from the variable displacement hydraulic pump 2 is prevented.

If a failure occurs in the control system for controlling the regulator 5 during the normal operation or the specific operation as described above, that is, the failure of the electromagnetic proportional valve 15 or the failure of the controller 16; failure of the pressure detectors 18, 21, 22; disconnection of wiring connecting these pressure detectors 18, 21, 22 to the controller 16; or connection of the controller 16 to the electromagnetic proportional valve 15. When a break occurs in the wiring or the like and a predetermined drive signal is not given to the electromagnetic proportional valve 15 and the control of the electromagnetic proportional valve 15 becomes impossible, similarly to the above-described first embodiment, , The pilot pressure signal guided through the pilot line 19 is guided to the regulator 5 as it is, and the normal operation which is the operation of the arm cylinder 7 and the like described above is performed. Kill. Even when a failure occurs in the control system for controlling the regulator 5 and the regulator 5 is controlled by the normal control signal, for example, by operating the bucket pilot valve 14a by a half stroke. The bucket cloud operation can be performed, and the driving operation of the turning motor 6 can be performed by performing the half stroke operation of the turning pilot valve 12.

Even in the second embodiment having the above-described configuration, the tilting amount of the variable displacement hydraulic pump 2 can be changed by controlling the drive of the electromagnetic proportional valve 15 with a predetermined drive signal output from the controller 16. It is possible to secure a desired actuator speed according to the type of actuator operation. Further, even when a failure occurs in the control system for controlling the regulator 5, a normal operation of the arm cylinder 7 and the like and a specific operation such as a bucket cloud operation and a driving operation of the swing motor 6 can be realized. The same operational effects as those of the first embodiment can be obtained.

In particular, in consideration of the type of work to be performed via the corresponding actuator, etc.
The characteristics of the specific control signal or the characteristics of the normal control signal can be easily changed by rewriting the storage contents such as 0, 101, and 102 as necessary, and a suitable waste according to the type of work. Pump flow control with less pressure.

FIG. 6 shows claims 1, 2, 3, 4, and 5 of the present invention.
FIG. 7 is a hydraulic circuit diagram showing a configuration of a third embodiment corresponding to 5, 7, and 8, FIG. 7 is a block diagram showing a main configuration of a controller provided in the third embodiment shown in FIG. 6, and FIG. 6
The center bypass flow rate in the third embodiment shown in FIG.
FIG. 4 is a characteristic diagram illustrating a relationship with a signal pressure applied to a regulator 5.

FIG. 6 shows only the arm cylinder 7 as an actuator and only the arm directional control valve 10 as a directional control valve in order to simplify the description. It has other actuators commonly included in hydraulic excavators and directional control valves for controlling the driving of these actuators.

In the third embodiment, both the arm directional control valve 10 and the directional control valve for another actuator not shown have a center bypass passage.

Further, the pump tilt control signal for driving the regulator 5 changes its value in relation to a change in the flow rate of the center bypass passage. That is, a center bypass flow rate detection device 20 is provided in the downstream portion of the center bypass passage, and the signal pressure which increases as the center bypass flow rate decreases with the center bypass flow rate detection device 20, that is, the relationship shown in FIG. Is introduced to the regulator 5 through the pilot line 80. The electromagnetic proportional valve 15 constituting the variable tilt control means described above is provided in the pilot line 80.

The above-described center bypass flow detecting device 20
A throttle 20a provided downstream of the center bypass passage;
A cylinder 20b juxtaposed to the throttle 20a, and a piston 20c disposed in the cylinder 20b and sliding according to a differential pressure between the upstream pressure and the downstream pressure of the throttle 20a.
And a pilot line 8 connected to the pilot pump 3
1, a relief valve 20d that changes its opening amount from a fully open position to a closed position via a spring when the piston 20c moves to the left in the drawing, and a pilot pipe located upstream of the relief valve 20d. And a stop 20e provided in the path 81. The above-mentioned pilot line 80 is configured to take out the pressure of the pilot line 81 located between the throttle 20e and the relief valve 20d as a signal pressure.

In FIG. 6, reference numeral 60a denotes a normal operation setting section for setting a tilt amount corresponding to the normal operation, for example, a tilt amount of the upper limit of 90%, and 60b a tilt amount corresponding to the first specific operation. The first specific operation setting unit 60c for setting the amount, for example, the tilt amount of the upper limit of 100%, sets the tilt amount corresponding to the second specific operation, for example, the tilt amount of the upper limit of 70%. The second specific operation unit 60 is a tilt amount selector that selects one of the setting units 60 a to 60 c and outputs an individual selection signal to the controller 16. As shown in FIG. 7, a table 10 similar to the tables 100 and 101 shown in FIG.
4, 105 and 106 are individually provided corresponding to the setting units 60a to 60c described above. For example, when the normal operation setting unit 60a is selected by the tilt selector 60, the corresponding tables 104 to 90 are set. % Of the maximum pump displacement, and the first specific operation setting unit 6
When 0b is selected, 1
The maximum displacement of the pump at the upper limit of 00% is output and the second
When the specific operation setting section 60c is selected, the pump maximum displacement of the upper limit of 70% is output from the corresponding table 106. In addition, this controller 1
6, a maximum value selecting means 103 similar to that shown in FIG. 5, that is, a maximum value selecting means 103 for selecting the maximum value of the pump maximum displacement output from the tables 104 to 106, and a table equivalent to that shown in FIG. 102, that is, a table 102 for obtaining an electromagnetic proportional valve output current corresponding to the pump maximum displacement target value output from the maximum value selecting means 103 and outputting the current to the electromagnetic proportional valve 15 as a predetermined drive signal is provided.

The above-described normal operation setting section 60a, first specific operation setting section 60b, second specific operation setting section 60c, tilt amount selector 60, and controller 16 for driving and controlling the electromagnetic proportional valve 15 Control means is configured.

In the third embodiment configured as described above,
When the operation performed by the hydraulic excavator is a normal operation, for example, a driving operation of the arm cylinder 7 or the like for excavation work or the like, the normal operation setting unit 60a is controlled by the tilt amount selector 60 shown in FIG. The selection is made, and the selection signal is input to the table 104 of the controller 16. Table 104
, The maximum pump displacement of 90% upper limit is output to the maximum value selecting means 103. The maximum value selecting means 103 calculates
The maximum pump displacement of the 0% upper limit is output to the table 102 as the maximum pump displacement target value. From this table 102, the electromagnetic proportional valve output current corresponding to the pump maximum displacement target value is obtained. At this time, an electromagnetic proportional valve output current corresponding to the pump maximum displacement target value corresponding to 90% of the pump maximum displacement is obtained, and a predetermined drive signal corresponding to this electromagnetic proportional valve output current is output to the electromagnetic proportional valve 15. Is done. Thus, the electromagnetic proportional valve 15 is maintained in a state where it is slightly closed from the maximum opening amount. Accordingly, the pilot pressure signal guided through the pilot line 80 is reduced in value and output as a normal control signal from the electromagnetic proportional valve 15 to the regulator 5, and the operation of the regulator 5 causes the tilt amount of the variable displacement hydraulic pump 2 to move. Is an upper limit of 90 suitable for this normal operation.
%, And the maximum flow rate with an upper limit of 90% is supplied to the corresponding actuator such as the arm cylinder 7 so that a desired normal operation can be performed.

In this case, for example, the arm pilot valve 1
In the state shown in FIG. 6 in which the valve 3 is not operated, the flow rate flowing through the center bypass passage of the arm directional control valve 10 is large, and accordingly, the difference between the upstream pressure and the downstream pressure of the throttle 20a is large. The piston 20c is in a state of being moved to the left in FIG. 6 in the cylinder 20b, and the relief valve 20d is kept in a fully opened state via a spring. Therefore,
The pilot pressure oil supplied through the pilot line 81 and the throttle 20e is released to the tank 70 through the relief valve 20d, and the pressure in the portion of the pilot line 81 located between the throttle 20e and the relief valve 20d is the lowest pressure. Becomes
This low pressure is applied to the regulator 5 via the pilot line 80.
And the minimum flow rate is discharged from the variable displacement hydraulic pump 2. From the state shown in FIG.
Is operated, the center bypass passage of the arm direction control valve 10 is gradually closed in accordance with the increase in the operation amount,
The flow rate flowing through the center bypass passage of the arm direction control valve 10 gradually decreases. Along with this, the aperture 20a
The difference between the upstream pressure and the downstream pressure gradually decreases,
The piston 20c is moved to the right in FIG. 6 in the cylinder 20b, and is controlled to gradually close the relief valve 20d via a spring. Accordingly, the pressure in the portion of the pilot line 81 located between the throttle 20e and the relief valve 20d gradually increases, and this increased pressure is guided to the regulator 5 via the pilot line 80, and the variable displacement hydraulic pump 2 , The maximum flow rate can be discharged within the range in which the upper limit of the tilt amount is 90%. FIG. 8 shows the relationship between the center bypass flow rate flowing through the center bypass passage of the arm direction control valve 10 and the signal pressure applied to the regulator 5, that is, the pilot pressure signal flowing through the pilot line 80. Valve 1
The value of the pilot pressure signal flowing through the pilot pipeline 80 increases in accordance with the increase in the operation amount of 3, and accordingly, the flow rate discharged from the variable displacement hydraulic pump 2 increases.

Also, for example, a larger flow rate than in the normal operation,
That is, when the operation is the first specific operation to be driven at a high actuator speed, the first specific operation setting unit 60 b is selected by the tilt amount selector 60, and the selection signal is input to the table 105 of the controller 16. Table 10
From 5, the maximum pump displacement of 100% upper limit is output to the maximum value selecting means 103. The maximum value selecting means 103 outputs the maximum pump displacement of the 100% upper limit value to the table 102 as the maximum pump displacement target value. Table 102
Then, the output current of the electromagnetic proportional valve corresponding to the input pump maximum displacement target value is obtained. Now, since the pump maximum displacement target value corresponds to the pump maximum displacement of the 100% upper limit, the electromagnetic proportional valve output current is determined to be zero.
Therefore, the controller 16 does not output a predetermined drive current, the electromagnetic proportional valve 15 is kept in the fully open state, and the first specific control is performed without changing the value of the pilot pressure signal guided through the pilot line 80 as it is. The signal is output to the regulator 5 as a signal. That is, in the third embodiment, unlike in the first and second embodiments, the first
This specific control signal constitutes one predetermined tilt control signal output to the regulator 5 when the electromagnetic proportional valve 15 is not driven.

With the operation of the regulator 5, the upper limit of the amount of displacement of the variable displacement hydraulic pump 2 is maintained at an upper limit of 100% suitable for the first specific operation. The maximum flow rate is delivered, and the corresponding actuator can be operated at a high speed to perform the desired first specific operation.

Conversely, when the second specific operation is to be driven at a smaller flow rate than the normal operation, that is, at a lower actuator speed, the tilt amount selector 60 sets the second specific operation setting section 60c. Is selected, and the selection signal is input to the table 106 of the controller 16. From the table 106, for example, a pump maximum displacement of 70% upper limit is output to the maximum value selecting means 103. The maximum value selecting means 103 outputs the maximum pump displacement of the 70% upper limit value to the table 102 as the maximum pump displacement target value. In the table 102, an electromagnetic proportional valve output current corresponding to the input pump maximum displacement target value is obtained. Now, the pump maximum displacement target value corresponds to the pump maximum displacement with the 70% upper limit, and a predetermined drive signal corresponding to the corresponding electromagnetic proportional valve output current is output to the electromagnetic proportional valve 15. As a result, the electromagnetic proportional valve 15 is kept closed by a considerable amount compared to the maximum opening amount. Along with this, the pilot pressure signal guided through the pilot line 80 is considerably reduced in value and outputted as a second specific control signal from the electromagnetic proportional valve 15 to the regulator 5, and the operation of the regulator 5 causes the variable displacement hydraulic pump 2 to operate. The upper limit of the amount of tilt of
Maintained at an upper limit of 70% suitable for this second specific operation;
A relatively small maximum flow rate, up to 70%, is supplied to the corresponding actuator so that the corresponding actuator can be operated at a lower speed to perform the desired second specific operation.

If a failure occurs in the control system for controlling the regulator 5 during the normal operation or the first and second specific operations as described above, the electromagnetic proportional valve 15, a failure of the controller 16, a failure of the tilt amount selector 60, a break in wiring connecting the controller 16 and the electromagnetic proportional valve 15, and a predetermined drive signal is given to the electromagnetic proportional valve 15. However, when a situation occurs in which the control of the electromagnetic proportional valve 15 becomes impossible, the pilot pressure signal guided through the pilot line 80 is guided to the regulator 5 as it is, and the above-described first specific operation can be performed. Even when a failure occurs in the control system for controlling the regulator 5 as described above and a special situation occurs in which the regulator 5 is controlled by the normal control signal, for example, the arm pilot valve 13
By performing a half-stroke operation, etc., a normal operation can be performed by driving the arm cylinder 7 and the like, and a second specific operation can be similarly performed.

Even in the third embodiment having the above-described configuration, similarly to the second embodiment, the drive of the electromagnetic proportional valve 15 is controlled by a predetermined drive signal output from the controller 16 to thereby control the variable displacement hydraulic pressure. The tilt amount of the pump 2 can be changed, and a desired actuator speed according to the type of actuator operation can be ensured. In addition, even when a failure occurs in the control system that controls the regulator 5, the first operation that operates the actuator at a high speed is performed.
Specific operation, a normal operation that is a driving operation of the arm cylinder 7 and the like, and a second operation that operates the actuator at a low speed.
Can be realized.

As in the second embodiment, the storage contents of the tables 104, 105, 106, and 102 are rewritten as necessary in consideration of the type of work performed via the corresponding actuator. Accordingly, the characteristics of the specific control signal or the characteristics of the normal control signal can be easily changed, and suitable and less wasteful pump flow control according to the type of work can be performed.

[0074]

As described above, according to the invention of each claim of the present invention, the displacement of the variable displacement hydraulic pump can be changed by appropriately driving the variable tilt control means, Even when a failure occurs in the control system that controls the regulator, it is possible to realize drive control of the actuator, which was not possible in the past, to prevent a reduction in the efficiency of work performed via the actuator, and Even when the above-described failure occurs, the operation mode of the hydraulic working machine can be easily changed.

In particular, according to the third aspect of the present invention,
Even if a failure occurs in the control system that controls the regulator, normal operations frequently performed on the hydraulic work machine are performed without considering special operations such as holding the directional control valve at half stroke. It is possible to

In particular, according to the invention of claim 4,
Even when a failure occurs in the control system that controls the regulator, specific operations that are performed less frequently by the hydraulic working machine than normal operations and special operations such as holding the directional control valve at half stroke are performed. It can be implemented without consideration.

In particular, according to the invention of claim 5,
The characteristics of the specific control signal or the characteristics of the normal control signal can be easily changed by rewriting the contents of the table as necessary in consideration of the type of work performed via the corresponding actuator. In addition, it is possible to perform a suitable and less wasteful pump flow control according to the type of work.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a first embodiment of a hydraulic drive device for a hydraulic working machine according to the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a signal pressure applied to a regulator provided in the first embodiment shown in FIG. 1 and a tilt amount of a variable displacement hydraulic pump.

3 is a characteristic diagram showing a relationship between a primary pressure, which is a pressure on the input side, and a secondary pressure, which is a pressure on the output side, of the electromagnetic proportional valve provided in the first embodiment shown in FIG.

FIG. 4 is a hydraulic circuit diagram showing a configuration of a second embodiment of the present invention.

FIG. 5 is a block diagram showing a main configuration of a controller provided in the second embodiment shown in FIG. 4;

FIG. 6 is a hydraulic circuit diagram showing a configuration of a third embodiment of the present invention.

FIG. 7 is a block diagram showing a main configuration of a controller provided in the third embodiment shown in FIG. 6;

FIG. 8 is a characteristic diagram showing a relationship between a center bypass flow rate and a signal pressure applied to a regulator in the third embodiment shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 motor 2 variable displacement hydraulic pump 3 pilot pump 5 regulator 6 swing motor 7 arm cylinder 8 packet cylinder 9 swing direction control valve 10 arm direction control valve 11 breaker direction control valve 11a bucket direction control valve 12 swing pilot valve 13 Pilot Valve for Arm 14 Pilot Valve for Breaker 14a Pilot Valve for Bucket 15 Electromagnetic Proportional Valve (Tilt Variable Control Means) 16 Controller (Drive Control Means) 17 Switch (Drive Control Means) 18 Pressure Detector (Drive Means) 19 Pilot Pipe line 20 Center bypass flow rate detection device 21 Pressure detector (drive control means) 22 Pressure detector (drive control means) 50 Breaker 60 Tilt amount selector (drive control means) 60a Normal operation setting section (drive control means) 60b The first specific operation unit (drive Control means) 60c second specific operation unit (drive control means) 70 tank 80 pilot line 81 pilot conduit 100 table 101 table 102 table 103 maximum value selection unit 104 table 105 table 106 table

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tsukasa Toyooka 650, Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. (72) Inventor Yasuharu Goto 650 Kandamachi, Tsuchiura-shi, Ibaraki Pref.Hitachi Construction Machinery Co., Ltd.

Claims (8)

[Claims] 1. A prime mover, a variable displacement hydraulic pump driven by the prime mover, an actuator driven by pressure oil discharged from the variable displacement hydraulic pump, and a pressure supplied to the actuator from the variable displacement hydraulic pump. A directional control valve for controlling the flow of oil; and a regulator for controlling the displacement of the variable displacement hydraulic pump. The variable displacement hydraulic pump is driven in accordance with an increase in the value of a pump displacement control signal for driving the regulator. In the hydraulic drive device for a hydraulic working machine that controls the variable displacement hydraulic pump to increase the displacement, the displacement of the displacement of the variable displacement hydraulic pump that enables the drive operation of the actuator is provided as the pump tilt control signal. Set multiple tilt control signals to make the upper limit different from each other. Given one of the number of the tilting control signal
A tilt control means for outputting a tilt control signal excluding the two tilt control signals, and outputting the predetermined one tilt control signal when not driven; and a predetermined tilt control means for driving the tilt variable control means. And a drive control means for outputting a drive signal. 2. The method according to claim 1, wherein the plurality of tilt control signals include a normal control signal corresponding to a normal operation that is frequently performed by the hydraulic work machine, and a frequency that is performed by the hydraulic work machine compared to the normal operation. The hydraulic drive device for a hydraulic working machine according to claim 1, further comprising at least one specific control signal corresponding to a specific operation having a low value. 3. The specific control signal has a characteristic of reducing the upper limit of the displacement of the variable displacement hydraulic pump as compared with the case of the normal control signal, and the predetermined one tilt control signal is 3. The hydraulic drive device for a hydraulic working machine according to claim 2, wherein the control signal is the normal control signal. 4. The specific control signal has a characteristic of increasing an upper limit value of a displacement of the variable displacement hydraulic pump as compared with the case of the normal control signal, and the predetermined one tilt control signal is 3. The hydraulic drive device for a hydraulic working machine according to claim 2, wherein the control signal is the specific control signal. 5. The drive control means has at least one of a table storing characteristics of the specific control signal and a table storing characteristics of the normal control signal, and corresponds to the characteristics stored in the corresponding table. The hydraulic drive device for a hydraulic working machine according to any one of claims 2 to 4, further comprising a controller that outputs a predetermined drive signal to the tilt variable control means. 6. An operation device for outputting an operation signal for switching and controlling the direction control valve, and wherein the pump tilt control signal for driving the regulator is the operation signal. The hydraulic drive device for a hydraulic working machine according to any one of claims 1 to 5. 7. The directional control valve has a center bypass passage, and the pump tilt control signal for driving the regulator changes its value in relation to a change in the flow rate of the center bypass passage. The hydraulic drive device for a hydraulic working machine according to any one of claims 1 to 5, wherein: 8. The system according to claim 1, wherein said regulator comprises a pilot type regulator operated by a pressure signal, said pump displacement control signal being a pressure signal, and said displacement variable control means being an electromagnetic valve. Item 1
A hydraulic drive for a hydraulic working machine according to any one of claims 7 to 13.