JPS61169683A - Hydraulic pressure circuit device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a hydraulically actuated member, an adjusting member that is slidable by a piston adjusting device on the hydraulically actuated member that is equipped with a pressure accumulator and that operates using hydraulic pressure. Pressurized liquid is supplied by a pump whose flow rate is changed through a pump, this adjusting member is pressed in one direction by an elastic means, and the piston adjusting device is connected to a first effective area where the pressure of the pressure side port of the pump always acts. a second effective area that can be pressurized; and a quick-acting valve that can be pressurized into two positions; 2. A hydraulic circuit arrangement, which is connected to a return line which is not in use, pressurizes the effective area in a second switching position, and further comprises a check valve between the hydraulic actuating member and the pump, which closes in the direction of the pump. It is.

[Prior art and its problems] German Patent Publication No. 2,521.367 describes a hydraulic system with a radial piston variable flow pump. This is controlled by pressure and flow rate, and in the supply line to the hydraulically operated member, there is a check valve that prevents flow toward the pump and the pressure side port of this pump. A diaphragm is inserted. Furthermore, a pilot valve is provided which communicates or shuts off the back pressure side line of the diaphragm, which communicates with the hydraulically actuated member and the piston adjustment device, and the unpressurized return line by the pressure of the hydraulically actuated member.

In order to change the flow rate, a cam ring-shaped adjusting member is slid steplessly between a minimum eccentricity position and a maximum eccentricity position by means of a piston adjusting device acting in conjunction with a spring. The piston adjusting device is provided with effective areas having different areas. The small-area effective region is acted upon by the front side of the diaphragm, that is, the pump discharge pressure, and the large-area effective fliR is communicated with the back pressure side conduit of the diaphragm. In order to change the stroke of the pump, the piston adjustment device acts on the adjustment member in such a way that the pump stroke of the radial piston pump changes in the direction of reducing the flow rate when the diaphragm pressure tends to increase. A spring device acts on this adjustment member in the direction of reducing the flow rate.

In conventional hydraulic systems, there may be a shortcoming on the input side of the hydraulic power. That is, the pressure-side port is coupled to the return line via a fairly high-pressure diaphragm of the hydraulically actuated member, and the minimum amount of pump delivery is achieved at the minimum eccentric position in order to increase the pump delivery. need to be maintained.

The present invention relates to the above-mentioned hydraulic circuit device, and an object of the present invention is to provide a hydraulic circuit device in which pressurized liquid is not discharged from the pump in a state where a flow rate is not required.

[Means for Solving the Problems, Actions and Effects] According to the hydraulic circuit device according to the present invention, the elastic means acts on the adjustment member in a direction to increase the flow rate, and the adjustment member is positioned at a position where the flow rate is maximum. Alternatively, the pump occupies one of the non-discharging positions, and the pressure side port and the return line are separated from each other in both switching positions of the quick-acting valve. The operation described above in this hydraulic circuit arrangement is such that when a low flow rate is required and a fairly high pressure is applied to the hydraulically actuated member, the second effective area is connected to the return line and the first effective area is pressurized. and the adjusting member is moved to the bowl discharge position.

The power consumption is almost zero, since the pump is set in an unpressurized state and therefore only a small amount of hydraulic pressure is required to overcome the hydraulic or mechanical friction losses. The discharge to the return line does not constitute a novel feature in the hydraulic circuit arrangement of the present invention.

Furthermore, in an embodiment of the invention, it is possible to use customary commercially available components and a vane-type pump is provided with an adjustment component in the form of a cam ring. In a preferred embodiment with respect to manufacture and assembly, the piston adjustment device comprises two pressurizable pistons radially opposite, an adjustment piston and an operating piston. These pistons differ in the size of their effective areas, advantageously in that the actuating piston, which is connected to the hydraulic actuating member via a quick-acting valve, has a large effective area.

Furthermore, elastic means are arranged on the actuation piston, which is connected to the hydraulic actuation member via the quick-actuation valve. Regarding the operating characteristics of the hydraulic circuit device, it is preferred that a stop member is arranged on the operating piston to adjust the zero displacement position.

The quick-acting valve is formed by a three-way, two-position seated valve whose valve closing member is actuated by hydraulic pressure and a control spring, the characteristic curve of pressure versus travel distance of the control spring being partially downwardly sloped; It is extremely simple and highly reliable.

The present invention will be described in detail below based on embodiments shown in the accompanying drawings.

[Embodiment j The hydraulic circuit device in this embodiment includes a steplessly variable vane type pump 1, and this pump 1 has a suction side port 2 and a pressure side port 3. 3 communicates with a pressure accumulator 5 via a check valve 4 that prevents flow in the direction of the pump 1, and communicates with a hydraulic actuating member 6 via a pressure-side fluid conduit.

If the hydraulic actuating member has a large capacity and the conduit is elastic, the pressure accumulator 5 is not necessary.

A variable displacement vane type pump 1 includes vanes or vanes that move within a plurality of grooves formed in the radial direction of the rotor, and the vanes are equipped with a cam formed by a cam ring 7 that is movable relative to the axis of the rotor. The vanes abut along the curve, and also form an operating chamber that is disposed between the cam ring 7 and the rotor circumference and is defined on both sides by the components of the housing.

The vane-type pump 1 is provided with a piston adjustment device 9 that acts on an adjustment member 8 in the form of a cam ring 7, which adjustment device 9 has two opposingly arranged adjustment pistons 10 and working pistons 11. It is equipped with a pressurizable piston. The operating piston 11 is the adjusting piston 10
The actuating piston 11 has a larger effective area than the cam ring 7, on which an elastic means 12 acts in the direction of the cam ring 7. The actuating piston 12 is movable and can abut a stop member 13 arranged stationary relative to the housing of the pump.

When the cam ring 7 is in contact with the actuating piston 11 and the actuating piston 11 is in contact with the stopper member 13, the cam ring 7 is arranged centrally with respect to the axis of the rotor. When the cam ring 7 is in this position, no pressure fluid is discharged.

The adjusting piston 10 connects a pressure side fluid line 15 to a fluid line from the pressure side port 3 to the hydraulic actuating member 6 via the check valve 4.
The actuating piston 11 is in continuous communication with the rapid acting valve 1 through the
6 to either a line communicating with the hydraulically actuated member 6 or a return line 18 communicating with the supply tank 17.

The quick-acting valve 16 is a three-way, two-position seated valve and is equipped with a control piston 21 which cooperates with a closing member 19 and is actuated by a disc spring 20 in the form of a disc.

The pressure of the hydraulic actuating member 6 is applied to the control piston 21 in a direction opposite to the direction in which the force of the disc spring 20 acts. This spring 20 exhibits a force-travel characteristic curve that is partially downwardly inclined, so that the closing member 19 can be moved between two switching positions for closing each opening 23, 24 of the valve chamber 22. Each of these openings 23,24 is provided with a valve seat. These 2
Between each opening 23 , 24 one opening 23 communicates with the return line 18 and the other opening 24 communicates with the hydraulic actuating member is a line communicating from the actuating piston 11 into the valve chamber 22 . is the provision. In the first switching position where high-pressure fluid is supplied to the hydraulic actuating member 6, the pressureless return line 18 and the actuating piston 11 are communicated with each other, and in the second switching position where low-pressure fluid is being supplied, the actuating piston 11 and the liquid are communicated with each other. It communicates with the pressure actuating member 6.

First, this hydraulic circuit device will be considered in a state in which the vane type pump 1 is not operating and pressure is acting on the hydraulic operating member 6 and the pressure accumulator 5. This pressure holds the quick-acting valve 16 in the first switching position, with the spring 20 deflecting downward and the actuating piston 11 communicating with the return line 18 and being isolated from the hydraulic actuating member 6. Ru. The pressure of the hydraulic actuating member 6 acts on the adjusting piston 10 of the pump and moves the cam ring 7 against the pressing force of the elastic means 12, bringing the actuating piston 11 into contact with the stop member 13.

When the cam ring 7 is in this position, the pump does not discharge fluid and no pressure is generated.

For lubrication, the housing is filled with oil and an oil film is formed on all rotating parts.

For example, when pressure fluid is consumed in a hydraulically actuated member and the pressure of this hydraulically actuated member decreases and reaches the lower switching pressure of the quick-acting valve, the hydraulic pressure acting on the control piston 21 of this quick-acting valve 16 causes The spring 20 bends upward and switches the quick-acting valve 16, thereby blocking the return line 18 and the actuating piston 11 and establishing communication between the hydraulic actuating member 6 and the actuating piston 11. Ru. Since the effective area of the actuating piston 11 is large and the elastic means 12 is acting, the actuating piston 11, to which the pressure of the hydraulic actuating member 6 is applied, moves the cam ring 7 to the left in the figure against the pressing force of the adjusting piston 1o. and the maximum flow position. When the pressure rises to the lower switching point of the quick-acting valve, this quick-acting valve switches quickly from the second switching position to the first switching position, the working piston 11 is in communication with the return line 18 and the cam ring 7 is therefore It is moved to the zero discharge amount position by the adjusting piston 10.

In order to ensure the pump discharge when the pressure of the hydraulic actuating member 6 is discharged, an elastic means 12 acts on the actuating piston 11 to move the cam ring 7 away from the stopper member 13 from the zero discharge amount position in the unpressurized state of the pump. Move to a distant position and set it as the discharge position.

[Brief explanation of drawings]

The figure shows a hydraulic circuit arrangement according to an embodiment of the invention. 1... Pump, 2... Suction side port, 3... Pressure side port, 4... Check valve, 5... Pressure accumulator, 6...
Hydraulic pressure actuation member, 7... Cam ring, 8... Adjustment member, 9... Piston adjustment device, 10... Adjustment piston, 11... Actuation piston, 12... Elastic means, 13
...Stopper member, 15...Pressure side pipe line, 16...
・Rapid action valve, 17...Tank, 18...Return pipe line, 19...Valve closing member, 20...Cop spring, 2
1... Control piston, 22... Valve chamber, 23.24.
...Aperture.

Claims (7)

[Claims] (1) A hydraulically actuated member, in particular a hydraulically actuated member with a pressure accumulator, is supplied with pressure fluid by means of a pump whose flow rate is varied by means of a piston adjusting device via a sliding adjusting member, which adjusting member is elastic. The piston adjustment device has a first effective region on which the pressure of the pressure side port of the pump always acts and a second effective region on which pressure can be applied, and further has two positions that can be switched by pressure. a quick-acting valve capable of connecting a second active area of the piston regulator to an unpressurized return line in a first switching position and pressurizing said active area in a second switching position; , further comprising a check valve closing in the direction of the pump between the hydraulic actuating member and the pump, the elastic means (12) increasing the flow rate relative to the regulating member (8). The adjusting member (8) occupies either the position of maximum flow or the position where the pump does not discharge, and the pressure side port (3) and the return line (
18) are separated from each other in both switching positions of the rapid-acting valve (16). 2. Hydraulic circuit arrangement according to claim 1, wherein the pump is a vane-type pump having an adjusting member (8) in the form of a cam ring (7). (3) The piston adjusting device (9) includes an adjusting piston (10) and an operating piston (11) which are arranged opposite to each other in the radial direction.
The hydraulic circuit device according to claim 1 or 2, comprising two pressurizable pistons. (4) Each of the pistons has an effective area of a different size, and the actuating piston (11) is connectable to the actuating member (6) via a quick-acting valve located on the side of the larger effective area. A hydraulic circuit device according to claim 3. (5) The elastic means (12) is arranged so that the actuating piston (11
5. Hydraulic circuit arrangement according to any one of claims 1 to 4, wherein the hydraulic circuit arrangement is arranged in a rapid-actuation valve (16) and connectable to a hydraulically actuated member (6) via a quick-acting valve (16). (6) The hydraulic circuit device according to claim 5, wherein the operating piston (11) is provided with a stopper member (13) for adjusting the discharge amount to zero. (7) The quick-acting valve (16) is operated by hydraulic pressure and a control spring (
20) is formed by a 3-way 2-position seated valve with a valve closing member (19) actuated at 20), the control spring (20) having a characteristic curve that partially slopes downwards when a force is applied. The hydraulic circuit device according to any one of the ranges 1 to 6.