JP2002257173A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized shock absorber showing large shock absorbing force. SOLUTION: The shock absorber is comprised of a cylinder 20 in which operating fluid is filled up and a piston 30 connected with a piston rod 40 is slidably arranged, and an accumulating chamber 50 capable of connecting with the cylinder through a fluid passage and also accommodating operating fluid equivalent to the volume of a piston rod 40 inserting into the cylinder 20 when absorbing shock. The cylinder 20 and accumulating chamber 50 are respectively arranged in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a shock absorber.

[0002]

2. Description of the Related Art Conventionally, as a shock absorber, a piston slides in a cylinder in response to an impact from an object to be buffered, and the working fluid filled in the cylinder flows through an orifice to reduce the impact. Alleviation is known.

[0003]

However, in the conventional shock absorber, the larger the shock absorption, the larger the inner diameter of the cylinder and the larger the outer dimensions. That is, in general, the shock absorbing capacity of the shock absorber and the external dimensions are proportional to each other, so that a device that absorbs a large shock needs to secure a suitable installation space, and the installation place is limited.

On the other hand, in a conventional shock absorber, an accumulator for accommodating a working fluid equivalent to a volume of a piston rod entering a cylinder when absorbing a shock is provided coaxially with the cylinder. General. Therefore, in order to keep the external dimensions within a predetermined size range, if the accumulator is provided along the outer periphery of the cylinder, the inner diameter of the cylinder is reduced accordingly, and the accumulator is connected in series with the cylinder. In the case of the provision, the effective stroke length of the piston is shortened, and the impact absorption capacity must be restricted.

The present invention has been made in view of the above points, and can be installed in a place where installation space is restricted without reducing the inner diameter of the cylinder and the effective stroke length of the piston, and can absorb a large impact. It is an object of the present invention to provide a shock absorber capable of performing the following.

[0006]

According to a first aspect of the present invention, there is provided a cylinder filled with a working liquid and having a piston slidably provided with a piston connected to a piston rod. An accumulator chamber that communicates with the cylinder through a liquid passage and that can store the working liquid equivalent to the volume of the piston rod that enters the cylinder when absorbing shock.
A shock absorber characterized in that the cylinder and the accumulator chamber are arranged in parallel with each other. According to a second aspect of the present invention, there is provided the shock absorber according to the first aspect, wherein one accumulator chamber communicates with two or more cylinders. According to a third aspect of the present invention, there is provided the shock absorber according to the first or second aspect, wherein a partition wall that makes the capacity of the accumulator chamber variable is provided. According to a fourth aspect of the present invention, there is provided the shock absorber according to the third aspect, wherein a spring for urging the partition is provided.
According to the fifth aspect of the present invention, in the shock absorber according to the third aspect, the partition body is provided so as to be able to return to a normal position by sending compressed air when absorbing no shock. I will provide a. In the present invention described in claim 6, the cylinder and the accumulator chamber are disposed in a thin and flat main body case formed in a thin shape. A shock absorber according to the preceding claims.

[0007]

Embodiments of the present invention will be described below in more detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a shock absorber according to one embodiment of the present invention. As shown in this figure, the shock absorber of the present embodiment includes a main body case 10, a cylinder 20, a piston 30, a piston rod 40, and an accumulator chamber 50.

[0008] As shown in FIG.
The outer dimension L in the thickness direction is smaller than the length direction (stroke direction of the piston 30) and is formed in a thin flat shape with a reduced thickness. The main body case 10 has first and second cylinders 20 which will be described later.
Holes 10a, 10b are formed near the left and right side surfaces and formed therethrough, and the first and second holes 10a, 10b are formed.
A third hole 10c which forms an accumulator chamber 50 to be described later is formed at an intermediate position of b. Also,
A bolt insertion hole 10d through which a bolt (not shown) for fixing the main body case 10 to the installation surface is provided so as to penetrate between the flat surface and the bottom surface (see FIGS. 1 and 3).
Further, as shown in FIG. 1, a through hole 10e forming a second passage 60b constituting a liquid passage described later is provided so as to cross between the left and right side surfaces.

The cylinder 20 is provided with the main body case 10 described above.
Are formed in a cylindrical shape having an outer diameter slightly smaller than the inner diameter of the first and second holes 10a and 10b, and a small hole is formed in the peripheral wall thereof as shown in FIGS. 1 and 2 (a). And a plurality of orifices 20a. In this embodiment,
Two such cylinders 20 are used, and each cylinder 20
Are bottom members 23 respectively fitted to both ends thereof.
Member 2 having a piston rod insertion hole 24a
And each is supported by the first
And in the second holes 10a and 10b. The outer diameter of each cylinder 20 is the same as that of the first and second holes 10.
a between the inner peripheral surfaces of the first and second holes 10a and 10b and the outer peripheral surfaces of the cylinders 20 through which a working liquid such as silicon oil can pass. One passage 60a is formed. The first passage 60a communicates with the orifice 20a and the second passage 60b formed through the peripheral wall of the third hole 10c, and the orifice 20a, the first and second passages 6,
A liquid passage is constituted by Oa and 60b.

The piston 30 is formed in a cylindrical shape having an outer diameter in which the outer peripheral surface is in sliding contact with the inner peripheral surface of each cylinder 20, and is disposed movably in each cylinder 20. As shown in FIG. 4, the interior of each cylinder 20 is partitioned into first and second chambers 21 and 22 by the piston 30. In the first chamber 21, the piston 30 and the bottom member 2
3, a return spring 71 is provided. Further, the first passage 60 described above is provided on the peripheral wall of each cylinder 20.
As shown in FIG. 4, when the shock is absorbed, the piston 30 moves in the cylinder 20 to form a return hole 20 b that communicates with the second chamber 22 of the cylinder 20. .

Each piston 30 has a piston rod 40
Are linked. As shown in FIG. 1, each piston rod 40 is provided so as to protrude in parallel to the outside of the main body case 10 through the piston rod insertion hole 24a of the bearing member 24, and has a protruding end portion. One plate-like member 80 is attached by an attachment bolt 80a.

The accumulator chamber 50 is shown in FIGS.
As shown in (b), the third hole 1 of the main body case 10 is formed.
0c, a lower surface of the first cap 53 provided at one opening end of the third hole 10c, and an outer surface whose outer peripheral surface is in sliding contact with the inner surface of the third hole 10c. It is formed so as to be surrounded by the upper surface of the partition body 51 having a diameter.
The first cap 53 is formed with a screw hole functioning as a working liquid injection port, and the working liquid is injected from the screw hole, filled in the accumulator chamber 50, and a liquid passage (the orifice 20a, First and second passages 6
0a, 60b). After the injection of the working liquid, the stopper 55 is screwed into the screw hole of the first cap 53, whereby the accumulator chamber 50 is sealed. On the other hand, the third hole 10c of the main body case 10 is divided into an accumulator chamber 50 and a liquid non-accommodating chamber 52 by the partition 51, and at the other open end of the third hole 10c, A second cap 54 formed similarly to the first cap 53 is provided. In the liquid non-accommodating chamber 52, a spring 72 is provided between the partition 51 and the second cap 54 facing the partition 51 so that the partition 51 presses the working liquid in the accumulator chamber 50. It is energizing.

The shock absorber of the present embodiment configured as described above is used with the main body case 10 fixed to an installation surface using bolts (not shown). At this time, according to the shock absorber of the present embodiment, the two cylinders 2
Since the zero and the accumulator chamber 50 are arranged in parallel with each other, the outer dimension L in the thickness direction of the main body case 10 is kept small while sufficiently securing the inner diameter of each cylinder 20 and the effective stroke of the piston 30. be able to. Therefore, installation is possible even in a place where a sufficient space cannot be secured in the thickness direction. Also, the main body case 10
Is formed in a flat shape, so that it can be easily attached to the installation surface, and each cylinder 20 and accumulator chamber 50
Are housed in the main body case 10 and are configured as a single unit, so that there is an advantage that the time required for installation and the work load are reduced.

As shown in FIG. 4, when a shock-absorbing object collides with the plate-shaped member 80 at the time of shock absorption, each piston rod 40 retreats, and the piston 30 connected to the piston rod 40 is moved. Is the first of each cylinder 20
It slides while pressing the working liquid filled in the chamber 21.
The working liquid pressed in the first chamber 21 flows out to the first passage 60a through the orifice 20a, but since the flow rate is restricted by the orifice 20a, a large resistance is generated at the time of passage, and the piston 30 On the other hand, it exerts a drag to suppress the movement. Thereby, the retreating operation of the piston rod 40 also becomes slow, and the shock by the buffer target can be absorbed. In this case, in the present embodiment, since the cylinders 20 are arranged in parallel and the two piston rods 40 are provided so as to protrude in parallel from the main body case 10, the impact due to the cushioning object is dispersed. Is done. In addition, the accumulator chamber 50 is the cylinder 2
Since it is provided in parallel with 0, the inner diameter of the cylinder 20 and the effective stroke of the piston 30 can be sufficiently ensured. Therefore, according to the shock absorber of the present embodiment, a large impact can be absorbed even if the shock absorber is small (thin).

The working liquid flowing out of the first chamber 21 of each cylinder 20 through the orifice 20a into the first passage 60a passes through the orifice 20a located on the side of the second chamber 22 by the movement of the return hole 20b and the piston 30. It flows into the second chamber 22 of the cylinder 20 and is temporarily stored. In addition, since a part of the piston rod 40 enters the second chamber 22 of each cylinder 20, the working liquid corresponding to the volume of the piston rod 40 flows through the second passage 60b communicating with the first passage 60a. Flow into the inside. As a result, the partition body 51 is provided with the spring 72.
Since the pressure of the working liquid larger than the urging force is applied, the partition 51 moves while compressing the spring 72. As a result, the capacity of the accumulator chamber 50 is expanded to a capacity capable of storing the working liquid corresponding to the volume of the piston rod 40 that has entered the second chamber 22, and the working liquid is stored.

On the other hand, when the external force applied to each piston rod 40 is removed, the partition wall 51 is pressed by the resilient force of the compressed spring 72 in the liquid non-accommodating chamber 52.
Is pushed up, the capacity of the accumulator chamber 50 is reduced, and finally returns to the normal position. Accordingly, the working fluid in the accumulator chamber 50 is pressed,
It flows out of the accumulator chamber 50 through the second passage 60b to the first passage 60a, and the first chamber 21 of each cylinder 20
It flows into the first chamber 21 through the orifice 20a located on the side. Further, in the first chamber 21 of each cylinder 20, the piston 30 and the piston rod 40 are pushed up by the elastic force of the return spring 71 compressed by the retreat of the piston rod 40. Thereby, the working liquid in the second chamber 22 of each cylinder 20 flows into the first chamber 21 of each cylinder 20 through the gap formed at the connection between the piston 30 and the piston rod 40, and the return hole 20b And flows out to the first passage 60a through the orifice 20a located on the second chamber 22 side, and the orifice 20 located on the first chamber 21 side of each cylinder 20.
a, and flows into the first chamber 21. Then, finally, as shown in FIG. 1, the piston 30 returns to the normal position.

In another embodiment of the present invention, the partition 51 can be returned to the normal position by sending compressed air into the liquid non-accommodating chamber 52 during non-shock absorption. In this case, in the above embodiment, the return spring 71 provided in the first chamber 21 of each cylinder 20 and the spring 72 provided in the liquid non-accommodating chamber 52 are not provided. For compressed air, a tube (not shown) connected to an air compressor (not shown) is connected to a second cap 54 provided at the other open end of the third hole 10c of the main body case 10. Then, it is sent from the air compressor into the liquid non-accommodating chamber 52 through the tube.

In the normal state, the liquid non-accommodating chamber 52 is filled with compressed air of a predetermined pressure, whereby the partition wall 51 is held at the normal position shown in FIG. At the time of shock absorption, the partitioning body 51 is pressed and moved by the working liquid flowing into the accumulator chamber 50, thereby discharging the compressed air in the liquid non-accommodating chamber 52, thereby reducing the capacity of the accumulator chamber 50. The working liquid corresponding to the volume of the piston rod 40 is stored in the accumulator chamber 50 in an enlarged manner. The tube connected to the second cap 54 is provided with a valve mechanism (not shown) for adjusting the flow of compressed air.

On the other hand, at the time of non-impact absorption, even if the external force applied to each piston rod 40 is removed, the liquid does not return as described in the above embodiment, and the liquid non-housing chamber 5 does not return.
The return operation is started only when the compressed air is sent into the inside 2. That is, according to the present embodiment, the partition body 51 can be returned to the normal position at an arbitrary timing, and the piston 30 and the piston rod 40 can be returned to the normal position. Specifically, when compressed air is sent into the liquid non-accommodating chamber 52 at an arbitrary timing,
The partition body 51 is pushed up by the compressed air, and the capacity of the accumulator chamber 50 is reduced, and finally, the accumulator chamber 50 returns to the normal position. Accordingly, the accumulator room 5
0 is pressed, and the working liquid flows through the liquid passage (the orifice 20a, the first and second passages 60a, 60a).
Through b), it flows into the first chamber 21 of each cylinder 20, and returns the piston 30 and the piston rod 40 to the normal position.

[0020]

As described above, the shock absorber of the present invention is filled with the working fluid and communicates with the cylinder through which the piston connected to the piston rod is slidably provided through the cylinder and the fluid passage. And at the time of shock absorption, an accumulator chamber capable of accommodating the working liquid corresponding to the volume of the piston rod entering the cylinder, wherein the cylinder and the accumulator chamber are respectively arranged in parallel. Be composed. Therefore, it can be installed in a place where a sufficient space cannot be secured in the thickness direction or the length direction, and it is possible to sufficiently secure the inner diameter of the cylinder and the effective stroke of the piston to absorb a large impact.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a shock absorber according to one embodiment of the present invention.

FIG. 2A is a sectional view taken along the line AA of FIG. 1;
(B) is sectional drawing of the BB part of FIG.

FIG. 3 is a vertical cross-sectional view of the main body case taken along a line CC in FIG. 1;

FIG. 4 is a diagram for explaining an operation of the shock absorber according to the embodiment.

[Explanation of symbols]

 Reference Signs List 10 Main body case 10a First hole 10b Second hole 10c Third hole 10d Bolt insertion hole 10e Through hole 20 Cylinder 20a Orifice 20b Return hole 21 First chamber 22 Second chamber 23 Bottom member 24 Bearing member 24a Piston rod insertion hole 30 Piston 40 Piston rod 50 Accumulator chamber 51 Partition body 52 No liquid storage chamber 53 First cap 54 Second cap 55 Plug 60a First passage 60b Second passage 71 Return spring 72 Spring 80 Plate member 80a Mounting bolts

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 3J069 AA53 AA58 AA59 CC09 CC10 CC15 CC16 DD50 EE34

Claims (6)

[Claims] 1. A cylinder filled with a working fluid and slidably provided with a piston connected to a piston rod, communicates with the cylinder through a liquid passage, and enters the cylinder when absorbing a shock. An accumulator chamber capable of storing the working liquid in an amount equivalent to the volume of the piston rod, wherein the cylinder and the accumulator chamber are arranged in parallel with each other. 2. The shock absorber according to claim 1, wherein one of the accumulator chambers communicates with two or more of the cylinders. 3. The shock absorber according to claim 1, further comprising a partition wall for varying the capacity of the accumulator chamber. 4. The shock absorber according to claim 3, wherein a spring for urging the partition is provided. 5. The method according to claim 1, wherein the partition body is in a non-shock absorbing state.
4. The shock absorber according to claim 3, wherein the shock absorber is provided so as to be able to return to a normal position by sending compressed air. 6. The cylinder and the accumulator chamber,
The shock absorber according to any one of claims 1 to 5, wherein the shock absorber is disposed in a main body case formed in a thin flat shape.