JPH0425542Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shock absorber that absorbs kinetic energy such as impact and noise.

[Conventional technology]

The conventionally known fluid pressure type shock absorber is
In the outer tube constituting the outer shell, there is a pressure chamber containing oil, a piston and piston rod that expands and contracts the volume of the pressure chamber, an accumulator, a plurality of orifices that communicate the pressure chamber and the accumulator, and a return that is contracted in the pressure chamber. It is equipped with a spring, and the kinetic energy applied to the piston rod is absorbed by oil contained in a pressure chamber.

However, the maximum absorbed energy in a shock absorber is almost determined by the volume of the pressure chamber, so increasing the maximum absorbed energy increases the piston stroke length, in other words, the overall axial length, which increases the installation space. The problem is that it becomes large.

In order to solve this problem, it is possible to make the pressure chamber larger in diameter, but simply making the pressure chamber larger in diameter will inevitably make the piston and piston rod larger in diameter, which will increase the overall weight. There is a problem.

[The problem that the idea aims to solve]

The problem to be solved by the present invention is to provide a shock absorber that requires a small installation space and has high strength against uneven loads.

[Means to solve the problem]

In order to solve the above problems, the present invention includes a pressure chamber containing oil in an outer tube, a piston and piston rod that expands and contracts the volume of the pressure chamber, an accumulator, a plurality of orifices that communicate the pressure chamber and the accumulator, and a pressure chamber that accommodates oil. In the shock absorber, which is equipped with a return spring contracted in a chamber and absorbs kinetic energy applied to the piston rod, the piston rod is provided with a recess that opens on the piston side, and is slidably inserted into a bearing attached to the outer tube. The piston, which is slidable relative to the piston, is provided with a recess that opens on the piston rod side, the piston is fitted into the recess of the piston rod, and the recess formed in these recesses forms a shaped container pressure chamber.

[Effect]

The kinetic energy applied to the piston rod is absorbed by the oil in the pressure chamber, whose volume decreases as the piston rod slides, flowing out of the pressure chamber through multiple orifices, and the spilled oil is stored in the accumulator. . When the piston rod returns to its original position due to the biasing force of the return spring,
The oil accumulated in the accumulator is returned to the pressure chamber.

In this case, by making the piston and piston rod movable relative to each other and forming a pressure chamber by a recess provided opposite to them,
The relative stroke length of the sliding portion can be shortened without reducing the volume of the pressure chamber.

In addition, by fitting the piston into the recess of the piston rod, the diameter of the piston rod and bearing can be made larger than when the piston rod is inserted into the recess of the piston, which increases the strength against uneven loads and improves durability. Moreover, the increase in the weight of the piston and piston rod can be minimized.

〔Example〕

FIG. 1 shows an embodiment of the present invention, in which a cup-shaped outer tube 1 having a mounting screw on its outer periphery is
A bearing 2 is fitted into the opening, and an accumulator 3 made of foamed rubber is provided between the inner peripheral surface of the tube 1 and the outer peripheral surface of an extension 2a of the bearing 2 extending toward the bottom of the tube. ing.

The piston rod 5 that slides on the bearing 2 is provided with a recess 5a that opens on the bottom side of the outer tube 1.
The piston 6 fitted into the recess 5a so as to be relatively slidable has a recess 6a opening on the rod side, and a recess 6a that is open on the rod side.
A pressure chamber 7 is provided with a plurality of orifices 8 arranged in parallel in the axial direction for communicating between the piston a and the outside of the piston, and is formed by opposing recesses 5a and 6a.
communicates with the accumulator 3 through the orifices 8, .
0 and a set screw 11 that presses it.

In addition, the bottom surface of the rod side of the pressure chamber 7 and the check valve 9
A return spring 14 is compressed between the piston rod 5 and a ball presser 13 that restricts the movement of the ball 9a, and the piston rod 5 is connected to an annular stopper 1 provided on the outer periphery of the tip.
5 is prevented from being pulled out from the bearing 2 by coming into contact with the stepped portion 2b of the bearing 2, and in this state, the orifices 8, . . . communicate with the outside of the pressure chamber 7.

Reference numeral 16 in FIG. 1 is a scraper attached to the bearing 2.

In the above embodiment, when kinetic energy is applied to the piston rod 5 whose tip protrudes outside the outer tube 1 by the biasing force of the return spring 14, the rod 5 resists the biasing force of the return spring 14 and moves to the right in the figure. As a result, the oil in the pressure chamber 7 whose volume is reduced flows out of the pressure chamber 7 through the orifices 8, .
is accumulated in

In this case, since the piston rod 5 and the piston 6 are made slidable relative to each other, and the pressure chamber 7 is formed by the recesses 5a and 6a provided facing them, the volume of the pressure chamber 7 is not reduced. The relative stroke length between the piston rod 5 and the piston 6 can be shortened, and thereby the axial length of the shock absorber can be shortened and the installation space can be reduced.

In addition, by fitting the piston 6 into the recess 5a of the piston rod 5, the diameters of the piston rod 5 and the bearing 2 become larger than when the piston rod 6a is inserted into the recess of the piston 6. The strength is increased and the durability is improved, and furthermore, the recesses 5a and 6a make it possible to minimize the increase in weight due to the enlargement of these diameters.

After absorbing the kinetic energy, when the piston rod 5 returns to its original position by the biasing force of the return spring 14, the oil accumulated in the accumulator 3 flows back into the pressure chamber 7 through the check valve 9.

[Effects of the invention] The shock absorber of the present invention has a pressure chamber formed by a concave portion facing the piston and piston rod, which slide relative to each other, so that the sliding portion can be reduced without reducing the volume of the pressure chamber. Since the stroke length can be shortened, the axial length of the entire shock absorber can be shortened and the installation space can be reduced.

In addition, by fitting the piston into the recess of the piston rod, the diameter of the piston rod and the bearing that supports it becomes larger, which increases the strength against uneven loads and improves the durability of the shock absorber. The increase in weight due to the large diameter can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention. 1... Outer tube, 3... Accumulator, 5... Piston rod, 6... Piston,
5a, 6a... recess, 7... pressure chamber, 8... orifice, 14... return spring.

Claims (1)

[Scope of Claim for Utility Model Registration] A pressure chamber containing oil in the outer tube, a piston and piston rod that expands and contracts the volume of the pressure chamber, an accumulator, a plurality of orifices that communicate the pressure chamber and the accumulator, and a pressure chamber that expands and contracts the volume of the pressure chamber. In the shock absorber, the piston rod is provided with a recess that opens on the piston side and is slidably inserted into a bearing attached to the outer tube, so that the recess slides relative to the piston rod. A shock absorber characterized in that a movable piston is provided with a recess that opens on the piston rod side, the piston is fitted into the recess of the piston rod, and the pressure chamber is formed by the recess provided in these recesses.