JP2797358B2 - Oil dash pot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an oil dash pot,
The present invention relates to an oil dash pot which is attached to various devices and used for purposes such as absorbing shock, reducing vibration, and preventing vibration.

[Conventional technology]

A conventional oil dash pot is configured as shown in, for example, FIG. 4 or FIG. In these figures, 1 is a cylinder, 2 is a piston member fitted reciprocally to the cylinder 1, and 3 is a rod 2A of the piston member 2.
, Which is slidable, and a cap member for keeping the liquid-tight space therebetween, a return spring 4 for returning the piston member 2 to a state before operation, and a viscous fluid 5 loaded in the pressure receiving chamber 6 for buffering. Reference numerals 7 indicate communication holes formed in the piston member 2.

Therefore, when an impact force is applied to the piston member 2 via the rod portion 2A, the pressure receiving chamber 6 is moved as the piston member 2 moves.
The impact force can be buffered by the viscous fluid 5 inside flowing out to the pressure relief chamber 8 through the communication hole 7. When the impact force is removed, the stopper portion 2B of the piston member 2 is restored by the spring force of the return spring 4 until the stopper portion 2B comes into contact with the lower surface of the cap member 3, and the viscous fluid 5 is moved from the relief pressure chamber 8 to the pressure receiving chamber. Returned to 6.

[Problems to be solved by the invention]

However, in the conventional oil dash pot, as shown in FIG. 4, when the number of the communication holes 7 or the cross-sectional area of the entire communication holes 7 is small, the impact force is increased, but the viscous fluid 5 is increased.
It is difficult to return to the pressure receiving chamber 6, so that the return is slow. Also, as shown in FIG. There is a problem that the buffering force against impact is weakened instead of returning to the chamber 6 quickly and easily.

SUMMARY OF THE INVENTION An object of the present invention is to provide an oil dashpot that returns quickly while maintaining a sufficiently high buffering force in order to solve the conventional problems as described above.

[Means for solving the problem]

In order to achieve this object, the present invention provides a cylinder defined by a pressure receiving piston in two closed chambers, a pressure receiving chamber and a relief pressure chamber, a viscous fluid contained in the pressure receiving chamber, and a bottom portion of the pressure receiving chamber. And a return spring disposed between the pressure receiving piston and the top of the pressure receiving piston, the return spring being provided on the pressure receiving piston for holding the pressure receiving piston at a return position, and communicating the viscous fluid between the pressure receiving chamber and the relief pressure chamber. An oil dash pot having a first communication hole and a second communication hole for allowing the shock force applied to the pressure receiving piston to be buffered, the valve holding being pressed and supported by the return spring at the top of the pressure receiving piston. And a valve plate that is movably received inside the valve holding member under the pressure of the viscous fluid, and that opens and closes the first communication hole by the movement thereof. When pressurizing the pressure chamber, the valve plate is pressed against the top of the pressure receiving piston by increasing the pressure of the viscous fluid to close only the first communication hole, and the return spring returns the pressure receiving piston to the return position. At the time of return, a flow control valve is provided which retreats from the top of the pressure receiving piston by decompression of the viscous fluid to open both the first and second communication holes.

According to the present invention, when the pressure receiving chamber is pressurized by the pressure receiving piston, the valve plate of the flow control valve is pressed toward the top of the pressure receiving piston by increasing the pressure of the viscous fluid, thereby forming the first communication hole. Only the valve is closed to restrict the flow rate of the viscous fluid flowing from the pressure receiving chamber to the relief pressure chamber, thereby increasing the buffering force against the impact force. Further, when the pressure by the pressure receiving piston is removed by releasing the impact force, the viscous fluid in the pressure receiving chamber is reduced by the return operation of the pressure receiving piston to the return position by the return spring, and both the first and second communication holes are opened. The valve plate of the flow rate valve operates so as to be opened, whereby the return flow rate of the viscous fluid returned from the pressure relief chamber to the pressure receiving chamber can be increased, and the return operation of the pressure receiving piston can be accelerated.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In this case,
Of the communication holes 7A and 7B provided in the piston member 2, the communication hole 7A is opened around the piston top surface 2C, but the communication hole 7B is connected to the relief pressure chamber 8 from the piston top surface. 2C
It is open toward the center of. Further, here, 11 is a valve plate for adjusting the movement of the viscous fluid between the pressure receiving chamber 6 and the relief pressure chamber 8, and 12 is a valve holding member for holding the valve plate 11 up and down. The valve holding member 12 constitutes a flow control valve that operates as described later. 11A and 12A
2A and 2B, the valve plate 11 and the valve holding member
It is a hole provided in the center of 12.

Thus, with the valve plate 11 housed in the valve holding member 12, the flange portion 12B of the valve holding member 12 is biased toward the piston top surface 2C by the spring force of the return spring 4 as shown in FIG. Keep 12B in contact with piston top surface 2C. The pressure receiving chamber 6 has a viscous fluid 5 as shown by a.
Is filled.

In the oil dash pot configured as described above, when an impact force is applied to the piston member 2 via the rod portion 2A, the hydraulic pressure in the pressure receiving chamber 6 is increased, so that the valve plate 11 The communication hole 7A is pressed against the top surface 2C, and closes the communication hole 7A that is open to the periphery of the communication holes 7A and 7B. Therefore, the viscous fluid 5 is guided to the pressure relief chamber 8 only from the communication hole 7B opened at the center, and the flow is restricted, so that the buffering force is increased.

When the impact force is removed, the piston member 2 operates to return to the original state as shown in FIG. 3B by the spring force of the return spring 4, whereby the pressure receiving chamber 6 is depressurized, and the valve plate 11 is depressed.
Is pushed back toward the valve holding member 12, and all the communication holes 7A and 7B are opened. Therefore, the fluid in the pressure relief chamber 8 can be quickly returned to the pressure receiving chamber 6, and the return speed of the piston member 2 can be increased.

〔The invention's effect〕

As described above, according to the present invention, a cylinder defined by a pressure receiving piston in two closed chambers of a pressure receiving chamber and a relief pressure chamber, a viscous fluid contained in the pressure receiving chamber, and the pressure receiving chamber A return spring disposed between the bottom of the pressure receiving piston and the top of the pressure receiving piston, for holding the pressure receiving piston at a return position; and a return spring provided on the pressure receiving piston for transferring the viscous fluid between the pressure receiving chamber and the relief pressure chamber. And an oil dash pot capable of buffering an impact force applied to the pressure-receiving piston, the oil-dash pot being supported by the return spring at the top of the pressure-receiving piston. The valve holding member includes a valve plate that is movably received inside the valve holding member under the pressure of the viscous fluid, and that opens and closes the first communication hole by the movement. At the time of pressurizing the pressure receiving chamber, the valve plate is pressed against the top of the pressure receiving piston by increasing the pressure of the viscous fluid to close only the first communication hole, and returns to the return position of the pressure receiving piston by the return spring. When returning, the flow control valve is retracted from the top of the pressure receiving piston by decompression of the viscous fluid to open both the first and second communication holes, so that the flow control valve is connected to the valve holding member and the valve. It is constituted by two members of a plate, and when receiving the impact force in which the pressure is applied to the pressure receiving chamber by the pressure receiving piston, the viscous fluid flowing out to the relief pressure chamber is restricted only through the second communication hole to reduce the impact force. In addition, when the impact force disappears and the pressure receiving piston returns, the first communication hole and the second communication hole are both opened to quickly return the viscous fluid from the relief pressure chamber to the pressure receiving chamber. Can be ideal Providing yl dashpot has become possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of the configuration of the oil dash pot of the present invention. FIGS. 2A and 2B are a plan view and a cross-sectional view showing an example of the configuration of the flow regulating valve according to the present invention. FIG. 3B is a sectional view showing an operating state and a returning state of the oil dash pot of the present invention, respectively, and FIGS. 4 and 5 are sectional views showing two modes of a conventional example. 1 ... cylinder, 2 ... piston, 2C ... piston top surface, 4 ... return spring, 5 ... viscous fluid, 6 ... pressure receiving chamber, 7A ... 1st communication hole, 7B ... 2nd communication hole 8 ... Pressure relief chamber.

Claims (1)

(57) [Claims] A pressure receiving piston and a pressure relief chamber are connected by a pressure receiving piston.
A cylinder defined by two closed chambers, a viscous fluid housed in the pressure receiving chamber, and a cylinder disposed between the bottom of the pressure receiving chamber and the top of the pressure receiving piston, and holding the pressure receiving piston at a return position. A return spring, and first and second communication holes provided in the pressure receiving piston for communicating the viscous fluid between the pressure receiving chamber and the relief pressure chamber, and an impact applied to the pressure receiving piston. In an oil dash pot capable of buffering a force, a valve holding member pressed and supported by the return spring at the top of the pressure receiving piston, and movably received inside the valve holding member by receiving the pressure of the viscous fluid. A valve plate that opens and closes the first communication hole by its movement, and when the pressure receiving piston pressurizes the pressure receiving chamber, the valve plate is moved to the top of the pressure receiving piston by increasing the pressure of the viscous fluid. When the pressure receiving piston returns to the return position by the return spring, the first pressure receiving piston is retracted from the top of the pressure receiving piston when the pressure receiving piston returns to the return position. An oil dash pot, comprising: a flow control valve for opening both of the communication holes.