JP2519098Y2 - Hydraulic drive circuit for damping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to improvement of a hydraulic drive circuit of a vibration damping device.

(Prior Art) As a vibration damping device for suppressing the vibration of a building, an active damping device in which an additional mass is supported on the building via a hydraulic cylinder is known.

The hydraulic cylinder is connected to the pump and the tank via the servo valve, and the piston rod expands and contracts by the hydraulic pressure supplied with the operation of the servo valve, driving the additional mass in the swaying direction and the reaction force to build the building. Vibration control.

(Problems to be solved by the invention) By the way, in such a conventional example, an accumulator is provided so that a required amount of hydraulic oil can be sent to a cylinder at a required speed during vibration damping, and the pressure in the accumulator is equal to or more than a predetermined value. At this time, excess oil from the pump is returned to the tank via the relief valve, that is, the pump is always driven by the set pressure of the relief valve, which causes large power loss, is uneconomical, and has a large capacity. Was required, and there was a problem in terms of noise and durability.

There is a system in which the vent circuit of the relief valve is opened and closed according to the pressure in the accumulator, that is, the pump is switched between unloading and onloading, but the rotation of the pump is maintained even in that case.

(Means for Solving the Problem) In order to solve such a problem, the present invention provides a hydraulic actuator for driving a load, a servo valve for controlling the hydraulic pressure supplied to the actuator, and a pump as a hydraulic drive source. , In a hydraulic drive circuit equipped with an accumulator that stores the hydraulic pressure from the pump and a relief valve that regulates the pressure of the main circuit, an electromagnetic switching valve that opens and closes the vent circuit of the relief valve, and a pressure that detects the pressure in the accumulator. Based on the switch and this detection signal, the pump stops when the pressure in the accumulator reaches the upper limit value, and once the pressure drops to the lower limit value, the electromagnetic switching valve is opened to unload the pump and then the pump is stopped. A controller is provided to control the drive so that the solenoid switch valve is closed and switched to the on-load state after a certain period of time. .

(Operation) When the pump accumulates sufficient pressure in the accumulator, that is, until the pressure in the accumulator drops from the upper limit value to the lower limit value, the rotation of the pump is completely stopped.
Driven only when high pressure oil needs to be delivered to the accumulator.

(Embodiment) In the drawings, 1 is a hydraulic cylinder that supports an additional mass 2 against a wall of a building, and the cylinder 1 is connected to a pump 4 and a tank 5 via a servo valve 3 and is used to operate the servo valve 3. The piston rod 1A expands and contracts by the accompanying hydraulic pressure, drives the additional mass 2 in the swaying direction, and the reaction force damps the building.

The main circuit 6 is provided with an accumulator 7 for accumulating the hydraulic pressure from the pump 4, a relief valve 8 and a check valve 9 for returning excess oil to the tank 5. Relief valve 8
Is equipped with an electromagnetic switching valve 11 that opens and closes the vent circuit 10. When the electromagnetic switching valve 11 is closed, it operates at the pressure set by the spring 8A (on-load state), and when the electromagnetic switching valve 11 opens, the pump 4
The discharge amount of is returned to the tank 5 at low pressure (Unloaded state)
It has become.

Reference numeral 12 is a controller that controls the electric motor 14 of the pump 4 and the electromagnetic switching valve 11 based on the upper limit setting and the lower limit setting by the pressure switch 13 that is turned on and off according to the pressure in the accumulator 7, and specifically, in the accumulator 7. The pump 4 is stopped when the pressure reaches the upper limit value, and when the pressure in the accumulator 7 drops to the lower limit value, the electromagnetic switching valve 11 is opened to temporarily drive the pump 4 in the unload state for a certain time. After a lapse of time, the electromagnetic switching valve 11 is closed and switched to the on-road state.

With such a configuration, the pump 4 has the accumulator 7
When sufficient pressure is accumulated inside, that is, when the pressure in the accumulator 7 decreases from the upper limit value to the lower limit value, the rotation is completely stopped, and when high pressure oil needs to be sent to the accumulator 7. Only driven.

Therefore, the rotation loss of the pump 4 reduces power loss and noise, and the durability of the pump 4 and the like is improved accordingly, that is, the intervals for maintenance and replacement of the equipment can be lengthened.

When the drive of the pump 4 is started, the relief valve 8
The drive torque in the initial stage of rotation is small and almost no shock is generated because the vehicle is switched to the on-load state after a certain period of time has passed since it started to rotate in the unload state.

(Effect of the Invention) In short, according to the present invention, the rotation of the pump is completely stopped when sufficient pressure is accumulated in the accumulator, so that power loss and noise can be effectively reduced. The effect that the durability of the pump and the like is also improved is obtained. Also, when the pump is started, the relief valve can be switched to the on-load state after a certain time has passed since it started to rotate in the unload state, so the drive torque at the initial stage of rotation is small, and there is almost no shock. Can also be obtained.

[Brief description of drawings]

The drawing is a block diagram showing an embodiment of the present invention. 1 ... hydraulic cylinder, 2 ... additional mass, 3 ... servo valve, 4 ... hydraulic pump, 7 ... accumulator, 8 ...
Relief valve, 11 …… electromagnetic switching valve, 12 …… controller,
13 ... Pressure switch.

Claims (1)

(57) [Scope of utility model registration request] 1. A hydraulic actuator for driving a load, and a servo valve for controlling a hydraulic pressure supplied to the actuator,
In a hydraulic drive circuit of a vibration damping device that includes a pump as a hydraulic drive source, an accumulator that stores the hydraulic pressure from the pump, and a relief valve that regulates the pressure of the main circuit,
An electromagnetic switching valve that opens and closes the vent circuit of the relief valve, a pressure switch that detects the pressure in the accumulator, and the pump is stopped when the pressure in the accumulator reaches the upper limit based on this detection signal, and the pressure becomes the lower limit. When the value drops to a certain value, a controller is provided to open the electromagnetic switching valve, put it in the unload state, then drive the pump, and after a certain period of time, close the electromagnetic switching valve to switch to the on-load state. The hydraulic drive circuit of the damping device.