JPS5915762Y2 - Shock absorption mechanism at the working end of fluid equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a shock absorption mechanism that uses pressure fluid to absorb shock at the operating end of operating equipment.

A typical conventional example of the above mechanism is shown in FIG.

That is, in FIG. 1, when the piston member 2 reciprocably fitted into the cylinder member 1 approaches its operating end,
The cushion piece 3 protruding from the piston member 2 closes the main fluid discharge hole 4, and thereafter the lower chamber 5 of the piston member 2 is closed.
The fluid therein is evacuated in a controlled manner through the orifice 6.

The distance from when the cushion piece 3 begins to close the main discharge hole 4 until the piston member 2 reaches the operating end is usually called a cushion stroke.

The orifice 6 is provided with a needle valve 7.

This needle valve 7 is used to manually adjust the opening area of the orifice 6.

Therefore, the opening area of the orifice 6 is usually fixed.

In the conventional shock absorbing mechanism described above, when the cushion stroke is designed to be short, the opening area of the orifice 6 must be made small if the kinetic energy of the piston member 2 is constant.

However, if the opening area of the orifice 6 is made small, a large shock will occur at the moment the piston member 2 enters the cushioning process.

This is caused because, at the moment mentioned above, the fluid in the piston lower chamber 5 is in a state where it almost has no place to escape.

In order to avoid the above-mentioned shock, the piston lower chamber 5 at the time when the piston member 2 enters the cushioning process is
It must be ensured that the pressure of the fluid inside does not increase rapidly.

For this purpose, the opening area of the orifice 6 must be increased.

When the opening area of the orifice 6 is increased in this manner, the rate at which the kinetic energy of the piston member 2 is absorbed becomes smaller, making it necessary to lengthen the cushion stroke.

Therefore, in the conventional shock absorption mechanism, the piston member 2
In order to reduce the shock at the time of entry into the cushioning process and to reduce the shock at the operating end of the piston member 2, the cushion stroke must be made longer.

When the cushion stroke is lengthened in this way, there is a drawback that the time required to decelerate the piston member 2 becomes longer.

Another problem conventionally arises when the kinetic energy or inertial mass of the piston member 2 is frequently changed.

That is, in such a case, conventionally, the needle valve 7 must be adjusted each time, which is very cumbersome in terms of operation.

Furthermore, considering the case where only the inertial mass increases and the speed does not change due to the mechanism, the kinetic energy increases, so the aperture of the orifice 6 must be adjusted so that the opening area decreases.

This increases the shock when the piston member 2 enters the cushioning process.

As described above, the conventional mechanism has not been able to simultaneously smooth the deceleration of the piston member 2 and shorten the time required for deceleration.

Further, good shock absorption function could not be expected when the kinetic energy of the piston member 2 was changed.

In view of the above-mentioned shortcomings of the conventional mechanism, this invention attempts to improve and eliminate the drawbacks.In other words, this invention simultaneously satisfies smooth deceleration of the piston member and shortens the time required for deceleration. The purpose is to provide a mechanism.

Another object of this invention is to provide a mechanism that has a good shock absorbing function against changes in the kinetic energy of the piston member.

A further object is that the above mechanism is incorporated in the orifice part and has a very simple structure, and that its operation does not require any external assistance and achieves the above object by itself. It is characterized by having the ability to respond in various ways.

Structural advantages and details are revealed in the examples below.

FIG. 2 is a sectional view of the main parts showing an application example of the device of the present invention, in which 10 is a cylindrical cylinder member;
11 is a cylinder end member, 12 is a piston member slidably fitted into the cylinder member 10, and 13 is a cylinder member 1.
0 and a piston chamber airtightly closed and formed by the cylinder end member 11; 14, a main fluid discharge hole formed in the cylinder end member 11 so as to open toward the piston chamber 13;
15 is a cushion piece protruding from the end surface of the piston member 12 corresponding to the main discharge hole 14; 16 is an annular backing with a U-shaped cross section fixed to the periphery of the starting end of the main discharge hole 14; 17;
connects one end of the cylinder end member 11 to the piston chamber 13,
An orifice whose other end is opened toward the main discharge hole 14; 18, a pressure-responsive valve mounted on a part of the orifice 17; 19, a fine-adjustment valve rod mounted within the pressure-responsive valve 18; 20; 21 is a screw cylinder for adjusting the operating pressure of the pressure-responsive valve 18;
is a valve spring that presses the pressure-responsive valve 18 against the valve seat 22 of the orifice 17.

The pressure-responsive valve 18 has a hollow cylindrical shape and has small holes 23 and 24 in its tip and side wall.

The fine adjustment valve rod 19 is inserted into the pressure-responsive valve 18 to finely adjust the opening degree of the small hole 24 in the side wall of the pressure-responsive valve 18.

That is, the fine adjustment valve rod 19 is threaded through the threaded hole 25 of the operating pressure adjustment threaded cylinder 20 of the pressure responsive valve 18 so that it can be rotated from the outside.

Further, a threaded cylinder 20 for adjusting the operating pressure of the pressure-responsive valve 18 is screwed into a threaded hole 26 of the cylinder end member 11.

The pressure-responsive valve 18 is connected to the valve spring 2 by the threaded cylinder 20.
1 to the valve seat 22 of the orifice 17.

The pressing force of the pressure-responsive valve 18 against the valve seat 22 is the same as that of the screw cylinder 20.
It is adjusted by rotating the .

In the first embodiment, the valve seat 22 of the pressure-responsive valve 18 is
By appropriately setting the pressing force on the piston member 1 and the opening degree of the small hole 24 by the fine adjustment valve rod 19,
2 enters the cushioning phase, the increase in fluid pressure occurring in the piston chamber 13 is allowed to escape because the pressure-responsive valve 18 moves back against the valve spring 21 and opens the onofice 17.

When the fluid pressure in the piston chamber 13 becomes smaller, the pressure-responsive valve 18 is brought into pressure contact with the valve seat 22 of the orifice 17 by the valve spring 21, and from then on, the fluid in the piston chamber 13 flows through the small hole 23, 24 of the pressure-responsive valve 18. released.

Therefore, what is shown in the above application example allows the speed of the piston member 12 to be reduced very smoothly during a relatively short cushion stroke.

FIG. 3 is a sectional view of a main part of the device according to the present invention, in which the opening degree of the orifice 41 is reduced as the pressure in the piston chamber 40 becomes higher than the set pressure.

That is, when the fluid pressure in the piston chamber 40 is below the set pressure, the orifice 41 maintains a constant opening degree,
The opening degree of the orifice 41 is reduced as the pressure becomes higher than the set pressure.

For this purpose, a pressure-responsive valve 43 is provided in the orifice 41 of the cylinder end member 42, and this pressure-responsive valve 43 is pressed in the direction of opening the orifice 41 by a valve spring 44, and the pressing direction of the valve spring 44 is in the piston chamber. The direction is opposed to the fluid pressure within 40.

The device of the present invention is extremely effective in alleviating the impact at the end of the movement when the kinetic energy of the piston member 45 increases.

As explained above, in this invention, when the piston member slidably fitted into the cylinder member approaches its operating end,
In the shock absorption mechanism, the main fluid discharge hole is closed by a cushion piece provided in the piston member, and the piston member is decelerated by subsequently discharging the fluid in the piston chamber from a small-diameter orifice. Since a pressure-responsive valve is provided that is pressed in the direction of opening the orifice by a valve spring, and the direction in which the spring is pressed is opposite to the direction in which the fluid pressure in the piston chamber acts, the valve spring automatically responds to changes in the load and speed of the piston member. It is possible to obtain a shock absorbing function that follows, smooth the deceleration of the piston member, and shorten the time required for deceleration.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view of a shock absorption mechanism at the operating end of a conventional fluid device, Fig. 2 is a sectional view of the main part showing an application example of the present invention, and Fig. 3 is a sectional view of the main part of the device of the present invention. It is. 40... Piston chamber, 41... Orifice, 42.
...Cylinder end member, 43...Pressure-responsive valve, 44...
・Valve spring.

Claims (1)

[Scope of utility model registration request] When the piston member, which is slidably fitted into the cylinder member, approaches its operating end, a cushion piece provided in the piston member closes the main fluid discharge hole, and thereafter the fluid in the piston chamber is discharged from the small diameter orifice. In the shock absorption mechanism, the piston member is decelerated by causing the orifice to be pressed in the direction of opening the orifice by a valve spring, and the direction in which the valve spring is pressed is controlled by the action of the fluid pressure in the piston chamber. 1. A shock absorption mechanism at an operating end of a fluid device, characterized in that a pressure-responsive valve facing the direction is provided, and the opening degree of the orifice can be automatically changed depending on fluid pressure in a piston chamber.