JP2004169878A - Driving device of hydraulic motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device of a hydraulic motor which reduces energy loss which produces in the case of complexly driving a plurality of hydraulic motors. <P>SOLUTION: The driving device of the hydraulic motor is provided with supply passages 13, 14 which supply working fluid delivered from a pump 3 to the first and the second motor 1, 2, and a first and a second flow control valves 11, 12 which adjust amount of the working fluid supplied to the first and the second motors 1, 2, respectively. In such the driving device, it is provided with high pressure selection valves 31, 32 selecting higher load pressure from one of the first and the second motors 1, 2, a pump regulator 5 which adjusts displacement volume of the pump 3 in accordance with differential pressure between selected high load pressure and delivered pressure of the pump 3, and a first and a second motor regulators 51, 52 which adjust the displacement volume of the first and the second motors 1, 2, respectively, in accordance with differential pressure between similarly selected high load pressure and load pressure of the first and the second motors 1, 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement of a hydraulic motor driving device that compositely drives a plurality of hydraulic motors.
[0002]
[Prior art]
2. Description of the Related Art As a conventional hydraulic motor driving device, for example, there is one shown in FIG. Describing this, pressurized hydraulic fluid discharged from a single pump 3 is supplied to a plurality of motors 1, 2,... Via flow control valves 11, 12,. You. The flow control valves 11, 12,... Adjust the flow rates of the hydraulic fluid supplied to the motors 1, 2,. The pressure compensating valves 21, 22, ... maintain a constant differential pressure across the flow control valves 11, 12, ....
[0003]
The pump 3 includes a variable displacement mechanism 4 for varying the displacement, and a pump regulator 5 for adjusting the pressure for driving the variable displacement mechanism 4. The pump regulator 5 selects and guides the maximum load pressure from the load pressures of the motors 1, 2,... By the high-pressure selection valves 31, 32,. The load sensing control for changing the displacement of the pump 3 is performed. As a result, the amount of excess hydraulic fluid discharged from the pump 3 is suppressed, and energy consumption is reduced.
[0004]
The hydraulic motor drive device for a hydraulic shovel disclosed in Patent Document 1 is configured to suppress the occurrence of saturation in load sensing control.
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. Hei 4-326628
[Problems to be solved by the invention]
However, in the conventional hydraulic motor driving device shown in FIG. 2, among the motors 1, 2,..., The motor having the lowest load pressure is determined by the pump discharge pressure based on the highest load pressure. When driving the motors 1, 2,... Having a low load pressure, the pressure compensating valves 21, 22,.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydraulic motor driving device that reduces energy loss that occurs when a plurality of hydraulic motors are combined and driven.
[0008]
[Means for Solving the Problems]
A first invention provides a supply passage for supplying hydraulic fluid discharged from a pump to first and second motors, and first and second flow rates for adjusting hydraulic fluid volumes supplied to the first and second motors, respectively. The present invention is applied to a hydraulic motor driving device including a control valve.
[0009]
And a high-pressure selecting means for selecting and guiding a higher load pressure among the first and second motors, and adjusting a displacement of the pump according to a differential pressure between the selected high load pressure and the discharge pressure of the pump. A pump regulator and first and second motor regulators for respectively adjusting the displacements of the first and second motors according to the differential pressure between the high load pressure and the load pressure of the first and second motors also selected. It is characterized by having.
[0010]
Function and Effect of the Invention
According to the first aspect, the pump regulator performs load sensing control that changes the discharge flow rate of the pump according to the selected high load pressure. As a result, the amount of excess hydraulic fluid discharged from the pump is suppressed, and energy consumption is reduced.
[0011]
The first and second regulators adjust the displacement of the first and second motors in accordance with a change in the differential pressure between the selected high load pressure and their own load pressures to make the respective drive torques substantially equal, Perform load sensing control.
[0012]
For example, when the load pressure of the first motor is higher than that of the second regulator, the displacement of the first motor is greatly adjusted via the first motor regulator, and the load pressure of the first motor is reduced. On the other hand, the displacement of the second motor is adjusted via the second motor regulator so that the differential pressure between the two load pressures is reduced, and the displacement of the second motor is reduced.
[0013]
This makes it possible to eliminate the pressure compensating element provided together with the flow control valve in the conventional device, and reduce the energy loss discarded as heat generation in the pressure compensating element.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0015]
The hydraulic motor drive device shown in FIG. 1 is used, for example, to drive an air conditioner system mounted on a vehicle, and drives a hydraulic pump 3 driven by an engine, a compressor for compressing a refrigerant, a blower fan, and the like. , A plurality of hydraulic motors 1, 2, ..., supply passages 13, 14, ... for supplying hydraulic fluid discharged from the pump 3 to the motors 1, 2, ..., and hydraulic motors 1, 2, ... Are provided with flow control valves 11, 12,... For adjusting the supplied hydraulic fluid amount.
[0016]
The pump 3 is constituted by a variable displacement type piston pump that varies the displacement volume according to the inclination angle of the swash plate, and includes a pump regulator 5 that changes the inclination angle of the swash plate through a variable displacement mechanism 4.
[0017]
The pump regulator 5 guides the discharge pressure of the pump 3 through the pilot pressure passage 6 and, through the pilot pressure passage 7, selects one of the high pressure selection valves (high pressure selection means) among the load pressures of the motors 1, 2,. ) 31, 32,..., The highest load pressure is selected and guided, and the load sensing control for changing the displacement of the pump 3 in accordance with the differential pressure between the maximum load pressure and the discharge pressure of the pump 3 is performed.
[0018]
Each of the motors 1, 2,... Is constituted by a variable displacement piston motor that varies the displacement in accordance with the tilt angle of the swash plate, and changes the tilt angle of the swash plate via the variable capacity mechanisms 41, 42,. , And regulators 51, 52,.
[0019]
, The load pressure of each of the motors 1, 2,... Is guided through the pilot pressure passages 8, 9,. , The highest load pressure is selected and guided by each of the high-pressure selection valves 31, 32,..., And the motors 1, 2,. Load sensing control for changing the volume is performed.
[0020]
Each of the flow control valves 11, 12,... Adjusts the flow rate of the hydraulic fluid supplied to each of the motors 1, 2,. The controller 10 reads the rotational speeds of the motors 1, 2,... Detected by sensors (not shown), and adjusts the opening degrees of the flow control valves 11, 12,... So that the rotational speeds of the motors 1, 2,. Control.
[0021]
The operation as described above will now be described.
[0022]
The pressurized hydraulic fluid discharged from a single pump 3 is supplied to each of the motors 1, 2,... Via each of the flow control valves 11, 12,.
[0023]
The pump regulator 5 changes the discharge flow rate of the pump 3 according to the maximum load pressure of each of the motors 1, 2,..., And adjusts the discharge pressure of the pump 3 to be higher than the maximum load pressure by a constant differential pressure. Performs sensing (load response) control. As a result, the amount of excess hydraulic fluid discharged from the pump 3 is suppressed, and energy consumption is reduced.
[0024]
Each of the motor regulators 51, 52,... Adjusts the displacement of each of the motors 1, 2,. Load sensing control for equalizing the load pressure is performed. For example, when the load pressure of the motor 1 is the highest, the displacement of the motor 1 is adjusted to be the largest via the motor regulator 51, and the load pressure of the motor 1 is reduced. At this time, the displacement of the other motors 2,... Is reduced via the motor regulators 52,... So that the differential pressure between the load pressure of the motor 1 and the respective load pressures is reduced. As a result, each load pressure increases.
[0025]
This makes it possible to eliminate the pressure compensating element provided with the flow control valve in the conventional device, and reduce the energy loss discarded as heat generation in the pressure compensating element.
[0026]
It is apparent that the present invention is not limited to the above-described embodiment, and that various changes can be made within the scope of the technical idea.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a hydraulic motor drive device showing an embodiment of the present invention.
FIG. 2 is a hydraulic circuit diagram of a hydraulic motor driving device showing a conventional example.
[Explanation of symbols]
1, 2 Motor 3 Pump 5 Regulator 11, 12 Flow control valve 31, 32 High pressure selection valve (high pressure selection means)
41, 42 Variable capacity mechanism 51, 52 Regulator

Claims (1)

A liquid having a supply passage for supplying hydraulic fluid discharged from a pump to first and second motors, and first and second flow control valves for respectively adjusting hydraulic fluid volumes supplied to the first and second motors. In the pressure motor drive device,
A high pressure selecting means for selecting and guiding a higher load pressure among the first and second motors, and adjusting a displacement of the pump according to a differential pressure between the selected high load pressure and the discharge pressure of the pump. A pump regulator and first and second motor regulators for respectively adjusting the displacements of the first and second motors according to the differential pressure between the high load pressure and the load pressure of the first and second motors also selected. A hydraulic motor driving device, comprising:

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