JP3031298U - Control devices such as chairs - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To prevent a sudden decrease in pressure in a cylinder when the cylinder is returned to perform a quiet operation and to maintain a constant hydraulic pressure at all times. SOLUTION: In a chair or the like in which a proportional control valve is incorporated, a return side proportional control valve 14 provided on the discharge pipe side of a cylinder 1 (2) and a pressure holding valve 15 downstream of the return side proportional control valve 14.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to a control device for controlling the operation of a chair, an operating table, etc. (hereinafter referred to as a chair, etc.) that is hydraulically operated and has a proportional solenoid valve incorporated therein.

[0002]

[Prior art]

 Conventionally, a servo valve, a proportional solenoid valve (hereinafter referred to as a proportional control valve), or the like has been used to make a lifting operation of a chair or the like which is hydraulically operated and a tilting operation such as a backrest moderate. In particular, for control on the return side, the proportional control valve provided in the oil discharge line of the cylinder is provided downstream of the return solenoid valve, and the oil discharged via the proportional control valve is directly returned to the tank. There is. That is, the drain pipe of the return-side proportional control valve is directly connected to the tank.

[0003]

[Problems to be solved by the device]

 As described above, in a chair or the like in which a proportional control valve is incorporated and which is moved up and down and tilted, when looking at the hydraulic pressure holding state of the return side pipeline, high pressure is held from the cylinder to the solenoid valve. However, the pressure from the outlet of the solenoid valve to the tank is normal pressure. This is because the proportional control valve does not have a structure that completely holds the hydraulic pressure.

When the return side solenoid valve is opened during the return operation of the cylinder, the pressure of the cylinder reaches the proportional control valve at once, and the compression ratio of the hydraulic oil at the same location and the air content are contained. However, there is a problem that the cylinder descends all at once, which causes a shock when the cylinder starts.

The present invention is intended to solve the above-mentioned problems, and a constant hydraulic pressure is always maintained between the return solenoid valve and the proportional control valve. (EN) Provided is a control device such as a chair for opening a solenoid valve for use in the cylinder to prevent the pressure in the cylinder from rapidly decreasing when the cylinder is returned to the return operation, so as to obtain a smooth cylinder return operation.

[0006]

[Means for Solving the Problems]

 The control device for a chair or the like of the present invention is intended to achieve the above-mentioned object. As a means therefor, in a chair or the like in which a proportional control valve is incorporated, a return-side proportional control provided on the exhaust pipe side of a cylinder is provided. A pressure maintaining valve is provided downstream of the valve and the proportional control valve.

[0007]

[Embodiment of device]

 Hereinafter, an embodiment of a control device for a chair or the like according to the present invention will be described with reference to FIG. Reference numeral 1 is a hydraulically operated lifting cylinder, 2 is also a hydraulically operated raising and lowering cylinder, 3 is a chair body, 3a is a seat, and 3b is a backrest. With the above configuration, the lifting cylinder 1 is configured to lift and lower the chair body, that is, the seat 3a and the backrest 3b, and the tilting cylinder 2 to tilt the backrest 3b.

Reference numeral 4 is a tank for storing oil, and 5 is a motor pump for feeding oil into the cylinder. Reference numeral 6 is an actuation side proportional control valve for adjusting the amount of oil fed, which controls the speed of the cylinder and the like and the shock at the initial stage of operation to be alleviated. Reference numeral 7 is a relief valve, and 8 is an oil supply pipe.

Reference numeral 9 denotes an operating-side solenoid valve provided on the side of the pipeline for feeding oil to the tilting cylinder 2, and 10 denotes an operating-side electromagnetic valve provided on the side of the pipeline for feeding oil to the lifting cylinder 1. The operation of the lifting cylinder 1 or the tilting cylinder 2 is controlled by opening and closing the cylinders. Reference numeral 11 is a return oil side or return side solenoid valve of the back and forth tilting cylinder, and 12 is a descending side of the use cylinder, that is, a return side solenoid valve. 13 is an oil pipe line.

Reference numeral 14 is a proportional control valve on the return side, which controls the amount of return oil to reduce the cylinder return speed and the shock at the beginning of operation. When the backrest 3b is laid down, the return side solenoid valve 11 is opened, and the oil returns to the return side proportional control valve 14 through the conduit 13, and when the chair body 3 is lowered, the return side solenoid valve 1 2 Is a control device such as a chair in which oil is returned to the direction of the pipeline 13 when the valve is opened, and a conventionally known proportional control valve is incorporated therein.

Further, 15 pressure-holding valves are incorporated downstream of the pipeline 13. Reference numeral 16 denotes an oil discharge pipe, which is configured to return oil to the tank 4 described above. Therefore, the control for lowering the chair body 3 will be described. First, the return side solenoid valve 12 and the pressure holding valve 5 are set to “open”, but at that moment, between the lifting cylinder 1 and the return side proportional control valve 14. Since the pressure is still held, the hydraulic pressure of the lifting cylinder 1 does not drop sharply, so no shock occurs, and when gradually opened, the chair slowly descends.

At the time of stop, if the return side proportional control valve 14 is gradually closed, the chair stops quietly, but immediately before the chair is completely closed, the pressure holding valve 15 and then the return side electromagnetic valve are closed. When the valve 6 is "closed", the pressure is maintained between the lifting cylinder 1 and the pressure holding valve 15, and this state alleviates the shock at the time of starting the next return operation. The returning operation of the tilting cylinder 2 is also controlled in the same manner, so that the shock at the time of starting the returning operation of the backrest 3b (when the backrest goes to bed in the figure) is alleviated.

With the above configuration, if the pressure holding valve 15 is provided on the downstream side of the return side proportional control valve 14 and the pressure holding valve 15 is “closed” immediately before the end of the return operation, the pressure holding valve 1 is moved from the cylinder 1 (2). A predetermined pressure is maintained up to 5. With this configuration, even if the return side solenoid valve 11 (12) and the pressure holding valve 15 are opened in the next return operation, the pressure between the cylinder 1 (2) and the return side proportional control valve 14 is suddenly increased. It does not fall and the shock disappears. After that, if the return side proportional control valve 15 is gradually opened, the oil in the girinder 1 (2) is gradually vented and the chair body begins to return quietly.

[0014]

[Effect of device]

 Since the control device for the chair and the like of the present invention is configured as described above, in the conventional chair and the like that uses the proportional control valve, when the return side solenoid valve is opened, the hydraulic pressure of the cylinder suddenly increases at that moment. The chair descended and the shock was generated.However, even if the return side solenoid valve was opened, the specified pressure was always maintained between the cylinder and the return side proportional control valve, so the cylinder pressure dropped rapidly. Since there is no shock at the time of startup, the chair can gently start the return operation such as descending by gradually opening the proportional control valve, and the smooth operation of the cylinder can be obtained.

[Brief description of drawings]

FIG. 1 is a hydraulic structure diagram of a control device for a chair or the like according to an embodiment of the present invention.

[Explanation of symbols]

 1 Lifting Cylinder 2 Tilt Cylinder 3 Chair Body 3a Seat 3b Backrest 4 Tank 5 Motor Pump 6 Actuating Proportional Control Valve 8 Oil Supply Pipe 9, 10 Actuating Solenoid Valve 11, 12 Returning Solenoid Valve 13 Pipeline 14 Return Side proportional control valve 15 Pressure holding valve 16 Oil drain pipe

Claims (1)

[Scope of utility model registration request] 1. A chair or the like in which a proportional control valve is incorporated, wherein a return-side proportional control valve provided on the exhaust pipe side of the cylinder and a pressure-holding valve downstream of the proportional control valve are provided. Control device.