JPH11201052A - Variable displacement hydraulic pump control device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely operate running-in of a hydraulic pump without depending on operation of an operator or the like. SOLUTION: A controller 43 measures accumulated operation time of a hydraulic pump 11 based on a detection signal from an alternator 45, and while this accumulated operation time is within a running-in period set by a memory part 43A, a selector valve 41 is held in an opened condition. Pilot presure from a pilot oil pressure source 40 is thus supplied to a second pilot oil chamber 36 provided in a piston 32 in an oil pressure pilot part 30. While the selector valve 41 is opened, therefore, output of the hydraulic pump 11 can be limited by a servo actuator 15 as the running-in period, so running-in can be forcedly conducted, thereby durability and service life of hydraulic devices can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement of a construction machine which is provided in a construction machine such as a hydraulic shovel or a hydraulic crane and is preferably used for variably controlling a discharge amount of hydraulic oil from a hydraulic pump. Hydraulic pump control device.

[0002]

2. Description of the Related Art Generally, construction machines such as hydraulic shovels and hydraulic cranes are equipped with a variable displacement hydraulic pump driven by an engine. The hydraulic oil discharged from the hydraulic pump is switched by a directional control valve. Hydraulic motors such as supply / discharge, travel motor, swing motor, etc., or various hydraulic actuators such as hydraulic cylinders (hereinafter, hydraulic pumps,
Various hydraulic actuators, directional control valves, etc. are collectively referred to as hydraulic equipment).

The above-mentioned variable displacement type hydraulic pump is usually provided with displacement control means for tilting and driving a displacement variable portion such as a valve plate or a swash plate provided on the displacement pump. Controls the displacement of the hydraulic oil discharged from the hydraulic pump between the maximum displacement and the minimum displacement by tilting the variable displacement portion between the minimum displacement position and the maximum displacement position. It has a configuration.

When a construction machine is shipped as a new car or replaced with new hydraulic equipment for maintenance or the like, usually, the output of the hydraulic pump is limited to about 80% of the maximum output for a predetermined time (for example, 5
0 hours), so-called break-in operation is effective in extending the life of the hydraulic equipment.

[0005]

The running-in operation as described above is usually performed by an operator arbitrarily adjusting a fuel lever such as a throttle lever to reduce the engine speed. When the engine is rotated at a high speed without the adjustment of the hydraulic pump, the hydraulic pump may be operated at the maximum output from the start thereof without the break-in operation of the new hydraulic pump being performed appropriately.

In this case, the smooth operation of the hydraulic pump is impaired because the sliding surfaces such as the sliding surface between the cylinder block and the piston constituting the hydraulic pump are not sufficiently lubricated. In addition, the durability and life of the hydraulic pump may be reduced due to damage to each sliding surface. Further, other hydraulic devices such as a hydraulic cylinder and a directional control valve have the same problem as described above when operated at the maximum discharge pressure without running-in the hydraulic device.

Further, by replacing the hydraulic device with a new hydraulic device at the time of maintenance or the like and operating the hydraulic pump with the maximum output without appropriately performing the running-in operation, the oil whose condition is worse than that of the new oil (deteriorated oil) , The durability of the hydraulic pump may be significantly reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and makes it possible to reliably perform a break-in operation of a hydraulic device without depending on an operation of an operator and to improve durability and life of the hydraulic device. It is an object of the present invention to provide a variable displacement hydraulic pump control device for a construction machine which can be improved.

[0009]

According to a first aspect of the present invention, there is provided a construction machine having an engine mounted on a vehicle, the engine having a variable capacity section and driven by the engine. A variable displacement hydraulic pump, displacement control means for driving the displacement variable section in accordance with the discharge pressure of the hydraulic pump to variably control the displacement of the hydraulic pump between a maximum displacement and a minimum displacement, and An operation period setting means for setting a break-in operation period until the cumulative operation time of the pump reaches a predetermined time, and controlling the capacity of the hydraulic pump during the break-in operation period set by the operation period setting means. And limiting means for outputting a capacity limiting signal to the capacity control means in order to limit the output.

In a construction machine, the power of an engine is converted into the output of a hydraulic pump (discharge capacity × pressure) to operate hydraulic equipment to perform traveling and excavation work. By restricting, even when the engine is fully operated, the mechanical output of the construction machine is suppressed, and the running-in operation of the entire hydraulic equipment can be performed.

Therefore, according to the present invention, during the break-in operation period set by the operation period setting means, the limiting means outputs a capacity limiting signal to the capacity control means, and the capacity of the hydraulic pump is reduced. Is controlled so that the output of the hydraulic pump is limited to be less than the maximum output, so that the hydraulic equipment can be forcibly broken in and operated.

According to a second aspect of the present invention, the displacement control means controls the displacement of the hydraulic pump between the maximum displacement and the minimum displacement by using the discharge pressure from the hydraulic pump as its own pressure. And a second displacement control unit for controlling the displacement of the hydraulic pump by the pilot pressure from the pilot pressure source. The limiting means controls the displacement of the hydraulic pump during the running-in period to limit the output. The pilot pressure from the pilot hydraulic pressure source is supplied to the second displacement control unit, and the supply of the pilot pressure to the second displacement control unit is shut off after the break-in operation period.

With this configuration, during the break-in operation period, the limiting means supplies the pilot pressure from the pilot hydraulic source to the second displacement control unit, controls the displacement of the hydraulic pump, and controls the maximum output. Restrict. On the other hand, when the running-in period has passed, the limiting means cuts off the supply of the pilot pressure to the second displacement control unit to release the restriction on the output, and the first displacement control unit reduces the discharge pressure from the hydraulic pump by itself. The displacement of the hydraulic pump is controlled between the maximum displacement and the minimum displacement as the pressure.

According to a third aspect of the present invention, the limiting means is provided in the middle of an oil passage connecting the second displacement control section to the pilot hydraulic power source, and the operation detecting means for detecting the operation of the hydraulic pump. A switching valve that supplies the pilot pressure from the pilot hydraulic pressure source to the second displacement control unit when the valve is closed, and shuts off the supply of the pilot pressure when the valve is closed, and measures the cumulative operating time of the hydraulic pump according to a detection signal from the operation detecting unit. And a running-in control means for keeping the switching valve open until the cumulative operating time reaches the running-in operation period.

With this configuration, the break-in operation control means measures the cumulative operation time of the hydraulic pump in accordance with the detection signal from the operation detection means, and switches the accumulated operation time until the accumulated operation time reaches the break-in operation period. Hold the valve open. Thus, during the running-in period, the pressure oil from the pilot oil pressure source is supplied to the second displacement control unit, and the displacement of the hydraulic pump is controlled to limit the maximum output.

Further, according to a fourth aspect of the present invention, the displacement control means includes an actuator for driving the displacement variable portion of the hydraulic pump by the discharge pressure of the hydraulic pump, and an oil passage for supplying the discharge pressure of the hydraulic pump to the actuator. Provided on the way,
A capacity control valve configured to displace a spool having a large capacity side position and a small capacity side position by a spring that presses toward the large capacity side position and a pilot section that presses toward the small capacity side position, The pilot portion of the valve includes a plunger that presses the spool in accordance with the pilot pressure, a first pilot oil chamber that acts on the plunger using the discharge pressure from the hydraulic pump as the pilot pressure, and a plunger that controls the pilot pressure from the pilot hydraulic source. And a second pilot oil chamber that acts on the second pilot oil chamber to limit the output by controlling the capacity of the hydraulic pump during the running-in period. And after the running-in period, the second
In this configuration, the supply of the pilot pressure to the pilot oil chamber is interrupted.

[0017] With this configuration, during the break-in operation period, the restricting means operates the second control valve of the displacement control valve.
The pilot pressure from the pilot oil pressure source is supplied to the pilot oil chamber. For this reason, when the plunger presses the spool toward the small-capacity-side position against the spring, the actuator drives the displacement-variable portion of the hydraulic pump to control the displacement of the hydraulic pump, thereby limiting the maximum output. On the other hand, when the running-in period has elapsed, the limiting means cuts off the supply of the pilot pressure to the second pilot oil chamber of the displacement control valve. Therefore, when the spring presses the spool toward the large capacity side position, the actuator variably controls the capacity of the hydraulic pump between the maximum capacity and the minimum capacity according to the discharge pressure from the hydraulic pump.

Further, the invention according to claim 5 is characterized in that the limiting means is provided with a notifying means for notifying that it is within the break-in operation period.

With this configuration, it is possible to notify the operator or the like by the notification means that the running-in period is being performed.

Further, the invention according to claim 6 is characterized in that the limiting means executes break-in operation control after repairing or replacing a hydraulic device including a hydraulic pump and a hydraulic actuator.

With this configuration, the break-in operation can be appropriately performed when the hydraulic equipment is replaced or repaired during maintenance or the like.

According to a seventh aspect of the present invention, a construction machine is provided with a controller for controlling a machine operation in accordance with a program stored in a storage means, and the storage means of the controller includes a hydraulic pump and a hydraulic actuator including a hydraulic actuator. The present invention is configured to store a program for executing a break-in operation control by the control means when performing repair or replacement.

With this configuration, when repairing or replacing a hydraulic device including a hydraulic pump and a hydraulic actuator, the program for executing the break-in operation control by the control means is stored, so that the program is stored. Even with existing construction machines that have not been installed, repairing and repairing of hydraulic equipment and running-in after replacement can be performed properly.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A variable displacement hydraulic pump control device for a construction machine according to an embodiment of the present invention will be described below with reference to the accompanying drawings, taking as an example a case where the control device is applied to a hydraulic shovel.

First, FIGS. 1 to 4 show a first embodiment according to the present invention.
In FIG. 1, reference numeral 1 denotes a lower traveling body;
Is an upper revolving structure that is rotatably provided on the lower traveling structure. Between the upper revolving structure 2 and the lower traveling structure 1, a revolving device 3 for revolvingly driving the upper revolving structure 2 is provided.

A working device 7 comprising a boom 4, an arm 5, and a bucket 6 is provided on the upper swing body 2 so as to be able to move up and down, and a cab 8 and a machine room 9 are provided. An engine 10 for driving a hydraulic pump 11 and the like described below is provided.

Numeral 11 denotes a variable displacement type hydraulic pump driven by the engine 10. As the hydraulic pump 11, for example, an oblique shaft type or swash plate type hydraulic pump is used, and a variable displacement mechanism 11A such as a valve plate or a swash plate. Is tilted to control the pump capacity (discharge amount) variably. The hydraulic pump 11 discharges the hydraulic oil from the tank 12 as pressure oil into the main pipeline 13 as shown in FIG. (Not shown).

Numeral 14 denotes a pump regulator as displacement control means for variably controlling the displacement of the hydraulic pump 11 by tilting and driving the displacement variable mechanism 11A. The pump regulator 14 includes a servo actuator 1 described later.
5. It is composed of a capacity control valve 25 and the like.

Reference numeral 15 denotes a servo actuator which constitutes a part of the pump regulator 14. The servo actuator 15 is formed in a stepped cylindrical shape, and has a cylinder 16 provided with a large-diameter hole and a small-diameter hole on the inner peripheral side; The cylinder 16 includes lids 17 and 18 covering both ends, and a servo piston 19 slidably inserted on the inner peripheral side of the cylinder 16. Here, the servo piston 19 is provided between the large-diameter portion 19A inserted into the large-diameter hole of the cylinder 16 and the cylinder 16.
And a small diameter portion 19B inserted into the small diameter hole of the large diameter portion 1.
A large-diameter oil chamber 20 is defined between 9A and the lid 17, and a small-diameter oil chamber 21 is defined between the small-diameter portion 19B and the lid 18.

The large diameter portion 19A of the servo piston 19
Is connected to a variable displacement mechanism 11A of the hydraulic pump 11 via a link 22 and to a sleeve 28 described later via a link 23.

Reference numeral 24 denotes a pump line as an oil passage for supplying the discharge pressure of the hydraulic pump 11 to the servo actuator 15 as its own pressure. The pump line 24 is connected to the small-diameter oil chamber 21 of the servo actuator 15. The small-capacity side pipe 24A and the large-capacity side pipe 24 connected to the large-diameter oil chamber 20
B.

When the discharge pressure of the hydraulic pump 11 is supplied to the small-diameter oil chamber 21 through the small-volume pipe 24A, the servo piston 19 is slid in the direction of arrow A,
When the discharge pressure of the hydraulic pump 11 is supplied to the large-diameter oil chamber 20 through the large-capacity side pipeline 24B, the large-diameter oil chamber 20 slides and displaces in the direction of arrow B. When the servo piston 19 is displaced in the direction of arrow A, the hydraulic pump 11
When the displacement of the hydraulic pump 11 decreases in the direction indicated by the arrow C (small displacement side) and the servo piston 19 is displaced in the direction indicated by the arrow B, the variable capacity mechanism 11A The discharge amount of the hydraulic pump 11 is increased by tilting drive in the direction D (large capacity side).

Numeral 25 denotes a capacity control valve provided between the small capacity pipe 24A and the large capacity pipe 24B and provided in the middle of the pump pipe 24. The capacity control valve 25 is a pump port. , A valve casing (not shown) provided with an inflow / outflow port and a tank port, and slidably provided in the valve casing, from a neutral position (a) to a small capacity side position (b) or a large capacity side position. (C), a spring 27 for pressing the spool 26 toward the large-capacity side position (c), and the spool 26 against the spring 27 toward the small-capacity side position (b). Hydraulic pilot unit 30 which will be described later
And a sleeve 28 slidably provided between the spool 26 and the valve casing.

Here, the displacement control valve 25 has a pump port connected to the servo actuator 1 via the small-capacity side pipe 24A.
5 is connected to the large-diameter oil chamber 20 of the servo actuator 15 via the large-capacity pipe 24B, and the tank port is connected to the tank 12 via the tank pipe 29. Have been. The capacity control valve 25 is switched from the neutral position (a) to the small capacity side position (b) by being pressed by the hydraulic pilot unit 30, and is released by the spring 27 when the pressing force of the hydraulic pilot unit 30 is released. By being pressed, the position is switched from the neutral position (a) to the large-capacity side position (c).

Reference numeral 30 denotes a hydraulic pilot unit for pressing the spool 26 of the displacement control valve 25 against a spring 27. The hydraulic pilot unit 30 is a stepped cylindrical member slidably fitted in a casing 31. And a plunger 33 slidably inserted into the piston 32.

Here, the piston 32 has a large-diameter portion 32A and a small-diameter portion 32B. The large-diameter portion 32A defines an oil chamber 34 between the casing 32 and the small-diameter portion 32B.
A first pilot oil chamber 35 and a second pilot oil chamber 36 are formed between the plunger 33 and the plunger 33.

On the other hand, the plunger 33 has a large-diameter rod portion 33.
A and a small-diameter rod portion 33A having a small-diameter rod portion 33B.
The tip side projects from the piston 32 and presses the spool 26. Then, the pressure oil in the first pilot oil chamber 35 acts on the proximal end surface of the large diameter rod portion 33A, and the pressure oil in the second pilot oil chamber 36 acts on the end surface of the small diameter rod portion 33B. Configuration. In the present embodiment, a first displacement control unit is constituted by the spool 26 of the displacement control valve 25, the first pilot oil chamber 35 for pushing the plunger 33 of the hydraulic pilot unit 30, and the like. The second capacity control unit is constituted by the spool 26, the second pilot oil chamber 36 for pushing the plunger 33 of the hydraulic pilot unit 30, and the like.

Here, a pilot pressure for tilt control according to the operation of an operation lever (not shown) for tilt operation is supplied / discharged to / from the oil chamber 34 in the casing 31 through a pipe 37. It has become.

The first pilot oil chamber 35 in the piston 32 is connected to the main pipe 13 via a discharge pressure pipe 38, and the second pilot oil chamber 36 in the piston 32 is
It is configured to be connected to a pilot hydraulic power source 40 through a pilot pipe line 39.

Reference numeral 41 denotes a switching valve provided in the middle of the pilot line 39. The switching valve 41 normally holds a shut-off position (a) for shutting off the pilot line 39, and the solenoid valve 42 is connected to the solenoid portion 42 as will be described later. When the valve opening signal is output from the controller 43, the valve is switched to the valve opening position (b), and the pilot pressure (capacity limiting signal) from the pilot oil pressure source 40 is supplied to the second pilot oil chamber 36 of the piston 32.

Reference numeral 43 denotes a controller for controlling the construction machine.
It controls the turning rotation and the like. Further, the controller 43 implements a break-in operation control unit that forms a control unit together with the switching valve 41. And the controller 43
A switch 44, an alternator 45, etc., which will be described later, are connected to the input side, and the solenoid 4 of the switching valve 41 is connected to the output side.
2. The display lamp 47 and the like are connected.

The controller 43 has ROM, R
Storage unit 4 as storage means composed of AM, FD, CD, etc.
3A is provided, and the storage unit 43A constitutes an operation period setting means for setting a break-in operation period until the cumulative operation time of the hydraulic pump 11 reaches a predetermined time (for example, 50 hours).

Reference numeral 44 denotes a switch operated when instructing a break-in operation of the hydraulic pump 11, and the switch 44
Is located in a place where it is difficult for the operator to directly operate, for example, in a console box. The switch 44 is closed when the hydraulic equipment such as the hydraulic pump 11 or the hydraulic actuator is replaced with a new one during shipping of the construction machine or during maintenance, and outputs a switch signal to the controller 43.

Reference numeral 45 denotes an alternator for generating electric power for charging when the engine is operating. The alternator 45 outputs a detection signal to the controller 43 as the operating time of the hydraulic pump 11 while the engine is operating. .
Therefore, in the present embodiment, the alternator 45 constitutes an operation detection unit that detects the operation state of the hydraulic pump 11.

The controller 43 operates the switch 4
When the switch signal is output from the switch 4, the timer 46 is operated, and the time during which the detection signal is output from the alternator 45 is cumulatively added by the timer 46 to measure the operating time of the hydraulic pump 11. Then, until the cumulative operation time of the hydraulic pump 11 measured by the timer 46 reaches 50 hours corresponding to the break-in operation period set in the storage unit 43A, the controller 43
A valve opening signal is output to the solenoid portion 42 of the switching valve 41, and the display lamp 47 is turned on.

Reference numeral 47 denotes a display lamp as notification means for notifying the operator that the operation is within the break-in operation period. The display lamp 47 is provided, for example, in a cab of a construction machine. The display lamp 47 indicates the hydraulic pump 11
Is turned on until the accumulated operating time of the vehicle reaches 50 hours, thereby notifying the operator that the running-in operation is being performed.

This embodiment has the above-described configuration. First, when the construction machine is shipped or replaced with a new hydraulic device during maintenance, the switch 44 is used.
Is closed.

As a result, a detection signal from the alternator 45 is output to the controller 43 when the hydraulic pump 11 is started by operating the engine 10. Then, the controller 43 outputs the switch signal from the switch 44 and operates the timer 46.
6, the time during which the detection signal is output from the alternator 45 is cumulatively added, and the cumulative operating time T of the hydraulic pump 11 is measured.

Then, the controller 43 turns on the display lamp 47 until the cumulative operating time T of the hydraulic pump 11 reaches 50 hours corresponding to the break-in operation period set in the storage section 43A. And the solenoid unit 4 of the switching valve 41.
2 to output the switching signal 41 to the opening position (b).
To hold.

As a result, the pilot pressure from the pilot hydraulic pressure source 40 is supplied into the second pilot oil chamber 36 of the piston 32, and the discharge pressure line 38 is supplied to the plunger 33.
, The discharge pressure of the hydraulic pump 11 supplied into the first pilot oil chamber 35 and the pilot pressure supplied into the second pilot oil chamber 36 through the pilot line 39 act simultaneously.

In this state, the pump regulator 14
The variable displacement mechanism 11A of the hydraulic pump 11 is tilted and driven in accordance with the discharge pressure of the hydraulic pump 11 as described below.
1 is variably controlled based on a characteristic line 51 shown by a broken line in FIG.

First, the discharge pressure P from the hydraulic pump 11 is
When the pressure increases from the pressure P1 to the pressure P2, the plunger 33
Is the discharge pressure from the hydraulic pump 11 and the pilot hydraulic source 4
The spool 26 of the capacity control valve 25 is pressed by the pilot pressure from 0, and the capacity control valve 25 is switched to the small capacity side position (b). Thereby, the pressure oil in the large-diameter oil chamber 20 of the servo actuator 15 is discharged to the tank 12 through the large-capacity side pipeline 24B, and the hydraulic pump 11
Is introduced into the small-diameter oil chamber 21 of the servo actuator 15 through the small-capacity side pipeline 24A, and the servo piston 19 moves in the direction of arrow A. Then, the displacement of the servo piston 19 at this time is transmitted to the variable capacity mechanism 11A of the hydraulic pump 11 via the link 22, and the variable capacity mechanism 11A is tilted and driven in the direction of arrow C (small capacity side). Accordingly, the discharge amount Q of the hydraulic pump 11 decreases from the discharge amount Q1 to the discharge amount Q2.

At this time, the displacement of the servo piston 19 is also transmitted to the sleeve 28 of the displacement control valve 25 via the link 23, and the displacement of the displacement control valve 25 from the small displacement side position (b) to the neutral position (a) by the sleeve 28. ), The servo piston 19 and the variable capacity mechanism 11A
Stops, and the discharge amount Q of the hydraulic pump 11 holds the discharge amount Q2.

On the other hand, the discharge pressure P from the hydraulic pump 11 is
When the pressure decreases from the pressure P2 to the pressure P1, the spool 26 of the capacity control valve 25 is pressed by the spring 27, and the capacity control valve 25
Switches to the large capacity side position (c). Thereby, the discharge pressure from the hydraulic pump 11 is introduced into the large-diameter oil chamber 20 and the small-diameter oil chamber 21 of the servo actuator 15, and the servo piston 19 is caused by the pressure receiving area difference between the large-diameter portion 19A and the small-diameter portion 19B. Move in the direction of arrow B. Then, the displacement of the servo piston 19 at this time is transmitted to the variable capacity mechanism 11A of the hydraulic pump 11 via the link 22, and the variable capacity mechanism 11A is tilted and driven in the direction of arrow D (large capacity side). As a result, the discharge amount Q of the hydraulic pump 11 becomes
To the discharge amount Q1.

At this time, the displacement of the servo piston 19 is also transmitted to the sleeve 28 of the capacity control valve 25 via the link 23, and the capacity control valve 25 is moved from the large capacity side position (c) to the neutral position (a) by the sleeve 28. ), The servo piston 19 and the variable capacity mechanism 11A
Stops, and the discharge amount Q of the hydraulic pump 11 holds the discharge amount Q1.

Thus, during the break-in operation period until the cumulative operation time T of the hydraulic pump 11 reaches 50 hours, the pump regulator 14 maintains the same discharge pressure P based on the characteristic line 51 shown by the broken line in FIG. Even if there is, the discharge amount Q of the hydraulic pump 11 is controlled, and the output of the hydraulic pump 11 is limited.

Then, the cumulative operation time T of the hydraulic pump 11
When the running-in period has passed since 50 hours or more, the controller 43 turns off the display lamp 47 to notify the operator that the running-in operation has ended, and stops the output of the valve opening signal to the switching valve 41. I do.

Thus, the switching valve 41 is moved to the shut-off position (a).
Is switched to the piston 32 from the pilot hydraulic source 40.
The supply of the pilot pressure into the second pilot oil chamber 36 is shut off, and only the discharge pressure of the hydraulic pump 11 supplied into the first pilot oil chamber 35 through the discharge pressure pipe 38 acts on the plunger 33. Will do.

In this state, the pump regulator 14
The variable displacement mechanism 11A of the hydraulic pump 11 is tilted and driven in accordance with the discharge pressure of the hydraulic pump 11 as described below.
1 is variably controlled based on a characteristic line 52 shown by a solid line in FIG.

First, the discharge pressure P from the hydraulic pump 11 is
When the pressure increases from the pressure P1 to the pressure P2, the plunger 33
Is controlled by the discharge pressure from the hydraulic pump 11
5, the capacity control valve 25 is switched to the small capacity side position (b). As a result, as described above, the servo piston 19 moves in the direction indicated by the arrow A, and the variable displacement mechanism 11A of the hydraulic pump 11 is tilted and driven to the small displacement side, so that the discharge amount Q of the hydraulic pump 11 is reduced. Discharge volume Q
The discharge amount decreases from 1 'to the discharge amount Q2'.

On the other hand, the discharge pressure P from the hydraulic pump 11 is
When the pressure decreases from the pressure P2 to the pressure P1, the spool 26 of the capacity control valve 25 is pressed by the spring 27, and the capacity control valve 25
Switches to the large capacity side position (c). As a result, as described above, the servo piston 19 moves in the direction of arrow B, and the variable displacement mechanism 11A of the hydraulic pump 11 is tilted to the large capacity side, so that the discharge amount Q of the hydraulic pump 11 is reduced. The discharge amount increases from the discharge amount Q2 'to the discharge amount Q1'.

Thus, when the cumulative operating time T of the hydraulic pump 11 becomes 50 hours or more, and the running-in period elapses,
The pump regulator 14 controls the output of the hydraulic pump 11
The control is variably performed based on a characteristic line 52 indicated by a solid line in FIG.

Therefore, according to the present embodiment, after the break-in operation period has elapsed, the output characteristic of the discharge amount Q with respect to the discharge pressure P of the hydraulic pump 11 is set as indicated by the characteristic line 52. In the middle, the discharge pressure P of the hydraulic pump 11
The output characteristic of the discharge amount Q with respect to the characteristic line 52 is set as indicated by a characteristic line 51 shifted to a smaller capacity side than the characteristic line 52.

As a result, even if the break-in operation by the operator is not performed properly, the hydraulic pump 11,
The output of the hydraulic devices such as the hydraulic actuator and the direction control valve is limited until the accumulated operation time reaches 50 hours from the start, and the break-in operation is forcibly executed. Thereby, the break-in operation can be reliably performed without depending on the break-in operation of the operator, and the durability and the life of the hydraulic device can be improved.

That is, during the break-in operation period, the output of the hydraulic equipment is limited. Therefore, when the hydraulic pump 11 is replaced, the break-in operation of the hydraulic pump 11 can be performed, and other hydraulic equipment such as a hydraulic actuator can be operated. Is replaced, the other hydraulic equipment can be operated for break-in.

The engine 10 is powered by the hydraulic pump 1
Since the power is converted to the output of 1 (discharge capacity × pressure), hydraulic devices such as a hydraulic actuator and a directional control valve are operated to perform traveling and excavation work, the engine 10 is operated during the break-in operation period. Even at full operation, the mechanical output of the hydraulic excavator is suppressed, and the running-in operation of the entire hydraulic equipment can be performed.

That is, during the break-in operation period, the hydraulic pump 1
The output characteristic of the discharge amount Q with respect to one discharge pressure P is represented by a characteristic line 52.
To the characteristic line 51, the hydraulic pump 1
1 can be reduced, and not only the hydraulic equipment such as the hydraulic pump 11, the hydraulic actuator, and the directional control valve, but also the engine 10 can be run in. For example, during maintenance of the engine 10, By performing the running-in operation, the durability and life of the entire hydraulic excavator including the engine 10 can be improved.

During the running-in period, the display lamp 47
Is turned on, it is possible to inform the operator that the running-in operation is being performed, and it is possible to eliminate the sense of discomfort of the operator.

Here, the switching valve 4 by the controller 43
The break-in operation control process for 1 and the display lamp 47 will be described with reference to FIG.

First, when the processing operation starts, in step 1, the switch signal from the switch 44 is read, in step 2, the timer 46 is started, and in step 3, the detection signal from the alternator 45 is read.
Next, in step 4, the cumulative operation time T of the hydraulic pump 11 is measured based on the detection signal from the alternator 45, and in the following step 5, the cumulative operation time T of the hydraulic pump 11 is set in the storage unit 43A. It is determined whether it is less than 50 hours corresponding to the running-in period.

If "YES" is determined in step 5, it is during the running-in period.
Then, the display lamp 47 is turned on, and a valve opening signal is output to the switching valve 41 in step 7, and then the process returns to step 3.

On the other hand, if "NO" is determined in step 5, the accumulated operation time T becomes 50 hours or more, and the running-in period has passed.
7 is turned off, the output of the valve opening signal to the switching valve 41 is stopped in step 9, and the control process is terminated.

Next, FIGS. 5 and 6 show a second embodiment according to the present invention.
Is shown. In the present embodiment,
The same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 5, reference numeral 61 denotes a controller applied to the present embodiment in place of the controller 43 according to the first embodiment.
A storage unit 61A including an M, a RAM, an FD, a CD, and the like is provided. The storage unit 61A stores a break-in operation period until the cumulative operation time of the hydraulic pump 11 reaches a predetermined time (for example, 50 hours). An operation period setting means to be set is configured.

The output side of the controller 61 is connected to the solenoid part 42 of the switching valve 41 and the indicator lamp 47, and the input side is a speed sensor for detecting the number of revolutions of the engine 10 in addition to the switch 44 and the alternator 45. 6
2. A mode switch 63 for selecting an operation mode of the hydraulic pump 11, the engine 10, and the like is connected.

Here, the mode switch 63 is operated by, for example, an operator to change the operation mode of the hydraulic pump 11 and the engine 10 to S mode (speed sensing mode), P mode (high load mode),
The mode is switched to four modes of E mode (economy mode) and L mode (low load mode).

When the S mode is selected, the controller 61 performs control to increase the discharge amount of the hydraulic pump 11 according to the rotation speed of the engine 10. Also,
When the P mode is selected, the discharge amount of the hydraulic pump 11 is controlled according to the discharge pressure of the hydraulic pump 11. Further, when the E mode is selected, the output characteristic of the hydraulic pump 11 is adjusted by opening the switching valve 41 and supplying the pilot pressure from the pilot hydraulic source 40 to the second pilot oil chamber 36 of the piston 32. The characteristic line 52 in FIG.
To the characteristic line 51. In addition, when the L mode is selected, control is performed to reduce the maximum rotation speed of the engine 10 from, for example, 2000 rpm to about 1750 rpm.

This embodiment has the above-described configuration, and the break-in operation control processing for the switching valve 41 and the display lamp 47 by the controller 61 will be described with reference to FIG.

First, when the processing operation starts, the switch signal from the switch 44 is read in step 11, the timer is started in step 12, and the detection signal from the alternator 45 is read in step 13. Next, in step 14, the cumulative operation time T of the hydraulic pump 11 is measured based on the detection signal from the alternator 45, and in the subsequent step 15, the cumulative operation time T of the hydraulic pump 11 is set in the storage unit 61A. It is determined whether it is less than 50 hours corresponding to the running-in period.

If "YES" is determined in the step 15, since the break-in operation is in progress, the display lamp 47 is turned on in the step 16 and the step 1 is performed.
After outputting the valve opening signal to the switching valve 41 in step 7,
Return to

As a result, the pilot pressure from the pilot hydraulic source 40 is supplied to the second pilot oil chamber 36 of the piston 32, and the output characteristics of the hydraulic pump 11 shift from the characteristic line 52 in FIG. The output of the hydraulic pump 11 is limited, and the break-in operation is performed.

Thus, also in the present embodiment, during the break-in operation period of the hydraulic pump 11, the output characteristic of the discharge amount Q with respect to the discharge pressure P of the hydraulic pump 11 shifts to the smaller capacity side than the characteristic line 52. 51, the output of the hydraulic pump 11 is limited. Accordingly, the break-in operation can be reliably performed without depending on the break-in operation of the operator, and the durability and the life of the hydraulic pump 11 can be improved.

On the other hand, if "NO" is determined in the step 15, the accumulated operation time T of the hydraulic pump 11 becomes 50 hours or more, and the running-in period has passed, and the display lamp 47 is turned off in the step 18. At the same time, it is determined in step 19 whether the mode switch 63 has selected the E mode.

If "YES" is determined in the step 19, since the mode switch 63 has selected the E mode, a valve opening signal is output to the switching valve 41 in the step 17, and the second By supplying the pilot pressure from the pilot oil pressure source 40 to the pilot oil chamber 36, the output characteristic of the hydraulic pump 11 is changed by a characteristic line 51 in FIG.
And the hydraulic pump 11 is operated in the E mode.

On the other hand, if "NO" is determined in the step 19, since the mode switch 63 has selected a mode other than the E mode, the output of the valve opening signal to the switching valve 41 is stopped in the following step 20. After that, in step 21, the operation mode selected by the mode switch 63 is executed.

Thus, according to the present embodiment, in order to execute the E mode selected by the mode switch 63, the supply and discharge of the pressure oil from the pilot hydraulic source to the second pilot oil chamber 36 of the piston 32 is performed. Switching valve 4 for controlling
1 is provided. Therefore, the switch 44 is provided on the input side of the controller 61, and the alternator 45 is used as operation detection means.
And a timer function for measuring the cumulative operating time T of the hydraulic pump 11 based on the switch signal from the switch 44 and the detection signal from the alternator 45 is added to the controller 61.
The running-in operation can be reliably performed until the cumulative operating time T of the vehicle reaches 50 hours or more.

In each of the above embodiments, the controllers 43 and 61 execute the break-in operation control processing, but may be configured to execute the repair control processing shown in FIG. In this case, when the repair-time control process starts, the operator repairs and replaces the hydraulic equipment such as the hydraulic pump 11 and the hydraulic actuator in step 31. If the repair and replacement is completed in step 32, At 33, the break-in operation control process shown in FIG. 4 or FIG. 6 is executed.

Thus, even if the hydraulic equipment such as the hydraulic pump 11 and the hydraulic actuator is replaced with a new one during maintenance or the like, the running-in operation can be reliably performed. By operating the hydraulic device with the output, the hydraulic device can be prevented from being worn or damaged, and the durability of the hydraulic device can be improved.

In each of the above embodiments, the programs for executing the break-in operation control processing are stored in advance in the storage units 43A and 61A of the controllers 43 and 61. The processing may be executed, and the program may be newly stored when repairing or replacing the hydraulic equipment or the like.

In this case, when the repair control process starts,
The operator repairs the hydraulic pump 11 in step 41,
While performing the replacement work, for example, the ROM,
The storage units 43A and 61A made up of RAM, FD, CD and the like are replaced with those in which a program for running-in control processing is not provided and those in which the program is stored, and the switches 44 and the like are attached.

Then, when the replacement work in step 42 is completed, in step 43, the controllers 43 and 61 read in the running-in operation control program from the storage units 43A and 61A, and in step 44 the program shown in FIG. 4 or FIG. Execute the break-in operation control processing.

As a result, the present invention can be easily applied to a current hydraulic shovel or the like in which a program for the break-in operation control process is not provided, and the break-in operation of the hydraulic equipment can be easily and reliably performed.

In each of the above embodiments, the operation detecting means for detecting the operating state of the hydraulic pump 11 is provided by the switch 44.
And an alternator 45, the present invention is not limited to this. For example, an engine 10 such as a rotational speed sensor for detecting the rotational speed of the engine 10 may be used.
Alternatively, a configuration capable of detecting the operating state of the hydraulic pump 11 may be used instead of the alternator 45.

In each of the above embodiments, the case where the break-in operation period of the hydraulic pump 11 is set to 50 hours has been described as an example. However, the present invention is not limited to this, and the present invention is not limited to this. Run-in period less than 50 hours or 5
It may be set to 0 hours or more.

Further, in each of the above embodiments, the indicator lamp 47 indicates that the hydraulic pump 11 is in the running-in period.
Although the case of notifying the operator is described as an example, the display lamp 47 is not always necessary. Further, in place of the display lamp 47, a configuration may be employed in which the fact that the hydraulic pump 11 is in the running-in operation period is notified by, for example, sound or the like.

[0096]

As described in detail above, according to the first aspect of the present invention, when the hydraulic pump is in the running-in period set by the operation period setting unit, the limiting unit sends the capacity control signal to the capacity control unit. Is output, and the output is limited by controlling the capacity of the hydraulic pump.For example, at the time of shipment of construction equipment, or when replacing with new hydraulic equipment, etc., without depending on the running-in operation of the operator Thus, the break-in operation of the hydraulic equipment can be reliably performed.

During the break-in period, the output of the hydraulic equipment is limited.
The running-in operation of the hydraulic pump can be performed, and when another hydraulic device such as a hydraulic actuator is replaced, the running-in operation of the other hydraulic device can be performed. Properties and life can be improved.

According to the second aspect of the present invention, the displacement control means controls the displacement of the hydraulic pump between the maximum displacement and the minimum displacement by using the discharge pressure from the hydraulic pump as its own pressure. A control unit and a second displacement control unit that controls the displacement of the hydraulic pump by the pilot pressure from the pilot pressure source. The limiting unit controls the second displacement control unit to apply the pilot pressure to the second displacement control unit during the running-in period. From the pilot pressure from the pilot hydraulic pressure source during the break-in operation, the pilot pressure is supplied to the second displacement control unit after the break-in period. , The output of the hydraulic pump can be limited to be less than the maximum output. On the other hand, when the running-in period has elapsed, the limiting unit cuts off the supply of the pilot pressure to the second displacement control unit, thereby changing the displacement of the hydraulic pump according to the discharge pressure from the hydraulic pump to the maximum displacement and the minimum displacement. And can be variably controlled.

According to the third aspect of the present invention, the break-in operation control means measures the cumulative operation time of the hydraulic pump in accordance with the detection signal from the operation detection means, and measures the cumulative operation time until the break-in operation period is reached. During the break-in operation, the second displacement control unit is controlled by the second displacement control unit during the break-in operation because the switching valve provided in the middle of the oil passage connecting the second displacement control unit to the pilot hydraulic pressure source is kept open. A pilot pressure is supplied from a hydraulic source, and the capacity of the hydraulic pump can be controlled to limit the maximum output.

According to the fourth aspect of the present invention, when the break-in operation period is in progress, the limiting means operates the second control valve of the displacement control valve.
By supplying the pilot pressure from the pilot hydraulic pressure source to the pilot oil chamber, the plunger presses the spool toward the small-capacity side position against the spring, so that the actuator drives the displacement variable section of the hydraulic pump. The capacity of the hydraulic pump can be controlled to limit the maximum output. On the other hand, when the running-in period has passed, the restricting means cuts off the supply of the pilot pressure to the second pilot oil chamber of the displacement control valve, so that the spring presses the spool toward the large displacement position. Can variably control the displacement of the hydraulic pump between the maximum displacement and the minimum displacement according to the discharge pressure from the hydraulic pump.

According to the fifth aspect of the present invention, since the notifying means for notifying that the running-in period is being provided is provided, it is possible to notify the operator or the like of the running-in state by the notifying means. It is possible to eliminate operator discomfort.

According to the invention of claim 6, since the limiting means is configured to execute break-in operation control after repair or replacement of the hydraulic device including the hydraulic pump and the hydraulic actuator, the limiting device is replaced at the time of maintenance or the like. When repaired, the break-in operation can be performed properly.

Further, according to the invention of claim 7, the construction machine is provided with a controller for controlling the machine work according to the program stored in the storage means, and the storage means of the controller includes a hydraulic pump including a hydraulic pump and a hydraulic actuator. When repairing or replacing equipment, the program for executing the break-in operation control by the control means is stored. Therefore, when repairing or replacing the hydraulic equipment, the program for executing the break-in operation control by the control means is stored. Is stored, the break-in operation after repair and replacement of the hydraulic equipment can be appropriately performed even in a current construction machine in which the program is not stored.

[Brief description of the drawings]

FIG. 1 is an external view showing a hydraulic excavator to which a variable displacement hydraulic pump control device according to a first embodiment of the present invention is applied.

FIG. 2 is a hydraulic circuit diagram showing the variable displacement hydraulic pump control device according to the first embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a discharge amount and a discharge pressure of a hydraulic pump in FIG.

4 is a flowchart showing a break-in operation control process for a control valve or the like by a controller in FIG. 2;

FIG. 5 is a hydraulic circuit diagram showing a variable displacement hydraulic pump control device according to a second embodiment of the present invention.

6 is a flowchart showing a break-in operation control process for a control valve or the like by the controller in FIG. 5;

FIG. 7 is a flowchart showing control processing during repair by the controller.

FIG. 8 is a flowchart showing another repair control process performed by the controller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Hydraulic pump 11A Variable capacity mechanism 14 Pump regulator 15 Servo actuator 25 Capacity control valve 26 Spool 27 Spring 30 Hydraulic pilot part 35 First pilot oil chamber 36 Second pilot oil chamber 40 Pilot hydraulic source 41 Switching valve 43, 61 Controller 43A, 61A Storage unit 44 Switch 45 Alternator 47 Indicator lamp

Claims (7)

[Claims] 1. A variable displacement type hydraulic pump provided on a construction machine having an engine mounted on a vehicle and having a variable displacement section driven by the engine, and the displacement variable according to a discharge pressure of the hydraulic pump. Capacity control means for driving the unit to variably control the capacity of the hydraulic pump between a maximum capacity and a minimum capacity, and setting a break-in operation period until a cumulative operation time of the hydraulic pump reaches a predetermined time. Operating period setting means, and limiting means for outputting a capacity limiting signal to the capacity control means in order to limit the output by controlling the capacity of the hydraulic pump during the break-in operation period set by the operating time setting means. A variable displacement hydraulic pump control device for construction machinery, consisting of: A first displacement control unit that controls a displacement of the hydraulic pump between a maximum displacement and a minimum displacement by using a discharge pressure from the hydraulic pump as a self pressure;
A second displacement control unit that controls the displacement of the hydraulic pump by a pilot pressure from a pilot pressure source, wherein the limiting unit controls the displacement of the hydraulic pump during a running-in period to limit the output. 2. The structure according to claim 1, wherein a pilot pressure from a pilot hydraulic pressure source is supplied to the second displacement control unit, and the supply of the pilot pressure to the second displacement control unit is shut off after a break-in operation period. Variable displacement hydraulic pump control device for construction machinery. 3. The control device according to claim 1, wherein the restricting means is provided in an oil passage connecting the second displacement control unit to a pilot hydraulic power source and an operation detecting means for detecting the operation of the hydraulic pump. A switching valve that supplies a pilot pressure from a source to the second displacement control unit and shuts off the supply of the pilot pressure when the valve is closed, and measures a cumulative operating time of the hydraulic pump according to a detection signal from the operation detecting unit. 3. The variable displacement hydraulic pump control for a construction machine according to claim 2, further comprising a break-in operation control means for holding the switching valve in an open state until the accumulated operation time reaches the break-in operation period. apparatus. 4. The displacement control means is provided in an actuator for driving a displacement variable portion of the hydraulic pump by the discharge pressure of the hydraulic pump, and in an oil passage for supplying the discharge pressure of the hydraulic pump to the actuator. A capacity control valve that displaces a spool having a large capacity side position and a small capacity side position by a spring that presses toward the large capacity side position and a pilot unit that presses toward the small capacity side position, The pilot portion of the displacement control valve includes a plunger that presses the spool in accordance with a pilot pressure, a first pilot oil chamber that acts on the plunger with a discharge pressure from the hydraulic pump as a pilot pressure, and a pilot hydraulic pressure source. And a second pilot oil chamber that causes the plunger to act on the plunger. A pilot pressure from a pilot oil pressure source is supplied to the second pilot oil chamber to control the capacity of the hydraulic pump to limit the output, and a pilot pressure for the second pilot oil chamber is supplied to the second pilot oil chamber after a running-in period. The variable displacement hydraulic pump control device for a construction machine according to claim 1, wherein the supply of the hydraulic pump is interrupted. 5. The variable displacement hydraulic pump control device for a construction machine according to claim 1, wherein said limiting means is provided with a notifying means for notifying that it is within a break-in operation period. 6. The variable construction machine according to claim 1, wherein said limiting means is configured to execute break-in operation control after repair or replacement of a hydraulic device including a hydraulic pump and a hydraulic actuator. Displacement type hydraulic pump control device. 7. A construction machine is provided with a controller for controlling machine operation according to a program stored in a storage means, and the storage means of the controller is used when repairing or replacing hydraulic equipment including a hydraulic pump and a hydraulic actuator. A program for executing a break-in operation control by the control means.
7. The variable displacement hydraulic pump control device for a construction machine according to 4, 5, or 6.