JPH051737A - Rotary buffer device - Google Patents

Abstract

PURPOSE:To provide a rotary buffer device wherein friction is not increased even if an axial load is applied to a shaft, and an attenuation characteristic is satisfactorily kept. CONSTITUTION:A terminal member 48 provided on a casing 42 is in a sealing contact to ends of one side of an inner peripheral surface of the casing 42 and a fixed blade 40 in an axial direction. An elastic first seal 50 is arranged between the terminal member 48 and an end of one side of a movable blade 46 in an axial direction. A land 52 provided on a shaft 44 is in a sealing contact to an inner peripheral surface of the casing 42 and the other end of the movable blade 46 in an axial direction. An elastic second seal 54 is arranged between the land 52 and the other end of the fixed blade 40 in an axial direction. A support 56 of the shaft 44 is distanced from the land 52 by a gap 96 which has a width within a range of elasticity of the seals. The shaft 44 is movable in an axial direction within the range of the gap 96.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a rotary shock absorber,
For example, in a suspension of a vehicle, the present invention relates to a rotary shock absorber suitable for attenuating vertical swing motion of a suspension arm that supports wheels.

[0002]

2. Description of the Related Art There is a rotary shock absorber proposed with the intention of widening the usage modes by reducing the space restrictions (Japanese Patent Application No. 2-38974). This rotary shock absorber 10
As shown in FIG. 3, a cylindrical casing 14 having a plurality of (one is shown in the figure) fixed blades 12 extending in the axial direction on the inner peripheral surface at equal intervals in the circumferential direction, and a casing. 14 includes a shaft 16 rotatably supported in a liquid-tight state and a plurality of movable blades 18. The shaft 16 is a casing 14
And the fixed vanes 12 define the same number of liquid chambers as the fixed vanes 12, and one movable vane 18 is disposed in each liquid chamber and attached to the shaft 16. Means 20 for generating a damping force are provided inside the shaft 16.

The rotary shock absorber 10 is used by incorporating it into a trailing arm type suspension shown in FIG. 4, for example. At each lateral side of the vehicle body, the casing 14 of the rotary shock absorber 10 is attached to the support 22, and the support 22 is fixed to the vehicle body. The trailing arm 24 is attached to the portion of the shaft 16 protruding from the casing 14.
To connect the torsion bar 26 to the trailing arm 2
Connect to 4. The torsion bar 26 is connected to the trailing arm 24 on the left side with the support on the right side,
Also, the one connected to the trailing arm on the right side is arranged to be supported by the support 22 on the left side.

In the rotary type shock absorber shown in FIG. 3, the shaft 16 is projected from the end plate 28, the stabilizer bar 30 is connected thereto, and the left and right trailing arms 24 are connected via the stabilizer bar 30. Rolling may be suppressed.

[0005]

When the tire 32 is bound or rebounded while the vehicle is traveling, the trailing arm 24 swings up and down, and the torsion bar 26 is twisted. At the same time, the axis C1 of the torsion bar 26
Is separated from the rotation axis C2 of the shaft 16, bending occurs in the torsion bar 26, and this bending causes the torsion bar 26 to be displaced in the direction of arrow A in FIG. For example,
The length of the torsion bar 26 is 1100 mm, the distance from the tire ground contact point to the rotation axis C2 of the shaft 16, and the torsion bar 26.
The ratio of the distance from the axis C1 to the rotation axis C2 of the shaft 16
If the vertical stroke of the tire 32 is 5: 1 and the vertical stroke of the tire 32 is 100 mm, the torsion bar 26 will bend up to 0.5 mm.
Displaced to some extent.

In the structure shown in FIG. 3, the fixed blade 12 is fixed to the casing 14, while the pair of retainers 34 is fixed to the shaft 16 and is in contact with the end surfaces of the fixed blade 12 and the movable blade 18. As a result, the displacement of the torsion bar 26 due to the bending causes a force in the axial direction to be applied to the shaft 16, so that the retainer 34 and the retainer 34 are interposed between the retainer 34 and each blade.
And the end plate 28, or between the retainer 34 and the support 36, increases friction, which deteriorates the damping force characteristic of the rotary shock absorber.

It is an object of the present invention to provide a rotary shock absorber capable of maintaining good damping force characteristics without increasing friction even when a load is applied to the shaft in the axial direction.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a cylindrical casing having a plurality of fixed blades extending in the axial direction on its inner peripheral surface at circumferentially spaced intervals, and coaxially arranged in the casing. A rotary shock absorber having a rotatable shaft, and a movable blade disposed in each space defined by the casing, the fixed blade, and the shaft, the movable blade being attached to the shaft. An end member provided on the casing is in contact with the inner peripheral surface of the casing and an end surface on one side in the axial direction of the fixed blade in a sealed state, and a stretchable first seal is movable with the end member and the movable member. It is arranged between the blade and the end surface on one side in the axial direction. The land provided on the shaft is in contact with the inner peripheral surface of the casing and the end surface of the movable blade on the other side in the axial direction in a sealed state, and the elastic second seal is provided between the land and the fixed blade. It is arranged between the other end face in the axial direction. The shaft support is attached to the casing with a gap within the range of expansion and contraction of the seal in the axial direction from the land.
The shaft is axially movable within the gap.

[0009]

When the rotary shock absorber is used by incorporating it in a trailing arm type suspension or any other type suspension, when a force in the axial direction is applied to the shaft, the shaft is displaced together with the movable blade. With this displacement, the elastic seal expands and contracts.

Since the shaft is displaced within the gap, the friction between the land and each vane or between the end plate and each vane is substantially unchanged. On the other hand, the seal expands and contracts as the shaft is displaced to prevent liquid leakage. As a result, the damping force characteristics of the rotary shock absorber can be maintained substantially in the same state.

It suffices to support the shaft so as to be movable in the axial direction and dispose a stretchable seal between the end member and the movable blade and between the land and the fixed blade, which does not particularly complicate the structure. Absent.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIGS. 1 and 2, a rotary shock absorber includes a casing 42 having a plurality of fixed blades 40,
A rotatable shaft 44 and a plurality of movable vanes 46 are provided and include an end member 48, a first seal 50, a land 52, a second seal 54, and a support 56.

The casing 42 is formed in a cylindrical shape, and in the illustrated embodiment, two fixed blades 40 are arranged on the inner peripheral surface at equal intervals in the circumferential direction. The fixed blade 40 is attached to the inner peripheral surface of the casing 42 in a sealed state by a screw 58 so as to extend in the axial direction in the middle portion of the casing 42. It is preferable to arrange the seal 60 between the fixed blade 40 and the casing 42 to enhance the hermeticity.

The shaft 44 is hollow in the illustrated embodiment and is arranged in the casing 42 coaxially with the casing. The shaft 44 is rotatably supported by a bearing 62 mounted on the end member 48 and a bearing 64 mounted on the support 56, and contacts the inner peripheral surface of the fixed blade 40 in a sealed state. It is preferable to arrange the seal 66 between the shaft 44 and the fixed blade 40 to enhance the hermeticity.

Casing 42, fixed vanes 40 and shaft 4
Two spaces 68, 70 are thus defined by 4.
As will be described later, these spaces form two liquid chambers in combination with the end member 48 and the land 52. One movable blade 46 is arranged in each space. The movable blade 46 is a pin 7
It is attached to the shaft 44 in a sealed state by 2 and slides on the inner peripheral surface of the cylinder 42 in a sealed state. Seal 74 shaft 4
4 and the movable blade 46, and the seal 76 between the movable blade 46 and the inner peripheral surface of the casing 42,
It is preferable to enhance the hermeticity.

The end member 48 is provided on the casing 42,
The inner peripheral surface of the casing 42 and the end surface of the fixed blade 40 on one side in the axial direction are in contact with each other in a sealed state. In the illustrated embodiment, the end member 48 is a support member 78 formed in a cylindrical shape.
And a cap 79 detachably attached to the support member 78 by a bolt 80, and a seal ring 82 is provided between the support member 78 and the inner peripheral surface of the casing 42, and the fixed blade 40.
A seal 84 is disposed between the end face of the seal and the end face of the seal to improve the sealing performance. The end member 48 holds the bearing 62 by the support member 78 and the cap 79, and is fixed to the casing 42 by the screw 86, and is further connected to the fixed blade 40 by the bolt 88.

The first seal 50 is arranged between the end member 48 and the end surface of the movable blade 46 on one side in the axial direction. The seal 50 is made of an elastic material such as urethane rubber and expands and contracts in the axial direction of the casing 42.

The land 52 is provided on the shaft 44 and contacts the inner peripheral surface of the casing 42 and the end surface of the movable blade 46 on the other side in the axial direction in a sealed state. In the illustrated embodiment, the land 52 is formed integrally with the shaft 44, and a seal 90 is provided between the land 52 and the inner peripheral surface of the casing 42, and a seal 92 is provided between the end surface of the movable blade 46 and the seal. I am raising. The land 52 is connected to the movable blade 46 by a pin 94.

The second seal 54 is arranged between the land 52 and the end surface of the fixed blade 40 on the other side in the axial direction. The seal 54 is made of an elastic material such as urethane rubber, and expands and contracts in the axial direction of the casing 42 by the same amount as the first seal 50.

When four seals 50, 76, 92, 74 are arranged around the movable vane 46, as in the illustrated embodiment, the first seal 50 can be formed integrally with these seals. .. The same applies to the second seal 54.

The support 56 is attached to the casing 42 with a gap 96 within the range of expansion and contraction of the first seal 50 and the second seal 54 in the axial direction from the land 52, and supports the shaft 44. In the illustrated embodiment, support 5
6 includes a bearing 64, a cylindrical support member 98, and an oil seal 99, and the bearing 64 and the oil seal 99 are mounted on the inner circumference of the support member 98. The support member 98 has a flange 100, and the flange 1
00 against the flange 102 of the casing 42 and attached to the casing 42 by bolts and nuts.

At the portion of the land 52 facing the gap 96,
A sliding member 97 made of polytetrafluoroethylene or other material having a low coefficient of friction can be attached. Thereby, the rotational friction when the land 52 hits the support 56 can be significantly reduced.

The shaft 44 has portions 45a and 45c which fit into the two bearings 62 and 64, respectively, and these portions are fitted into the bearings and are rotatably supported. Further, the shaft 44 is axially movable within the gap 96. The shaft 44 extends to the outside of the casing 42 through the oil seal 99.

In the illustrated embodiment, the bearing 64 of the support 56 has an inner diameter greater than the inner diameter of the bearing 62 of the end member 48, while the shaft 44 has a portion 45a that fits into the bearing 64, a fixed vane 40 and a movable vane. A portion 45b provided with 46, a portion 45c fitted to the bearing 62
Has an outer diameter that decreases in this order. As a result, the end member 48 and the fixed blade 40 can be attached to the casing 42 in advance, and then the shaft 44 having the movable blade 46 can be inserted into the casing 42 and assembled in a predetermined position. In the shock absorber shown in FIG. 3, it is necessary to assemble the fixed blade 12 and the movable blade 18 between the pair of retainers 34 in the casing 14, but there is a slight error in the mounting position of the fixed blade 12. Even if there is, the assembling becomes difficult and the assembling property is bad, but according to the illustrated embodiment, such an inconvenience does not occur and the assembling property can be improved.

A damping force generating means 110 is provided inside the shaft 44. In the illustrated embodiment, the damping force generating means 11
Reference numeral 0 denotes a fixed piston 112 equipped with a seal on its outer periphery, which has a valve mechanism known per se consisting of two sets of ports and leaf springs engaging with each set of ports, and a fixed piston 11.
2 and a partition member 114, which is located at an interval 116 in the axial direction from 2 and has a seal attached to the outer periphery. The fixed piston 112 and the partition member 114 are attached to the tubular member 120, and the tubular member 120 is connected to the support member 118 attached to the end portion of the shaft 44, whereby the tubular member 120 is held at a predetermined position.

Casing 42, fixed vanes 40 and shaft 4
The spaces 68, 70 defined by 4 are covered by the end member 48 and the land 52 to form two liquid chambers.
A liquid passage is provided from the liquid chambers 68 and 70 to pass through the damping force generating means 110.

In the illustrated embodiment, the liquid chamber 68 has the movable blades 4.
6 to the two liquid chamber portions 69a and 69b, and the movable chamber 46 to the two liquid chamber portions 71a and 7a by the movable blade 46.
It is divided into 1b. Therefore, when the movable blade 46 rotates clockwise in FIG. 2, the liquid in the liquid chamber portion 69a is from the port 122 and the liquid in the liquid chamber portion 71a is from the port 124 to the fixed piston 112 and the partition member inside the shaft 44. 114 into the space 116 and then through one set of ports of the fixed piston 112 to the space 126 between the stationary piston 112 and the support member 118, and from the space 126 through the port 128 to the liquid chamber. Part 69b
The ports 122, 124, 128, and 130 are positioned so that they flow to the liquid chamber portion 71b via the port 130.

As a result of positioning the ports as described above,
When the movable vane 46 rotates counterclockwise in FIG. 2, the liquid in the liquid chamber portion 69b reaches the space 126 from the port 128 and the liquid in the liquid chamber portion 71b reaches the interval 126, and then the other of the fixed pistons 112. Passes through a set of ports to reach interval 116 and then from interval 116 to port 12
2 to the liquid chamber portion 69a and to the liquid chamber portion 71a via the port 124.

Free piston 1 with a seal on the outer circumference
40 is movably arranged inside the shaft 44 with a space 142 in the axial direction from the partition member 114 of the damping force generating means 110, and the space 142 is an expansion chamber of the liquid. In the space 144 on the right side of the free piston 140 in FIG. 1, air or other gas is sealed under pressure.
This makes it possible to absorb changes in the volume of the liquid.

To absorb the change in the volume of the liquid due to the temperature change, the liquid may be allowed to slowly flow over a relatively long period of time. For this purpose, a minute clearance between the shaft 44 and the end member 48 is used. it can. The liquid that has flowed out from such a gap is left in the space 1 on the left side of the support member 118 in FIG.
46, and thereafter, reaches a space 142 from a hole 148 having a minute diameter provided in the support member 118, through the tubular member 120,
The free piston 140 is moved.

In the rotary shock absorber, the generated torque T is given by T = PQ / 2π, where P is the generated pressure and Q is the theoretical discharge amount per rotation. In this equation, the value of Q is increased by increasing the rotation angle of the movable blades or by increasing the number of movable blades. Therefore, according to the present invention, the generated torque can be increased by either of them. In other words, this means that the rotary shock absorber can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotary shock absorber according to the present invention,
It is cut along line 1-1 of FIG.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view of a rotary shock absorber proposed by the applicant.

4 is a plan view of an essential part showing a suspension of a vehicle in which the rotary shock absorber shown in FIG. 3 is incorporated.

[Explanation of symbols]

 40 Fixed Blade 42 Casing 44 Shaft 46 Movable Blade 48 End Member 50 First Seal 52 Land 54 Second Seal

Claims (1)

Claim: What is claimed is: 1. A cylindrical casing having a plurality of fixed blades extending in the axial direction on an inner peripheral surface thereof at intervals in the circumferential direction, and a rotation arranged coaxially in the casing. A rotary shock absorber comprising a possible shaft and a movable vane arranged in each space defined by the casing, a stationary vane and a shaft, the movable vane being mounted on the shaft, the inner peripheral surface of the casing and the stationary vane. An end member provided in the casing, which is in contact with the end surface of the blade on one side in the axial direction of the blade in a sealed state, and a stretchability disposed between the end member and the end surface on the one side of the movable blade in the axial direction, A first seal,
Between the land provided on the shaft in sealing contact with the inner peripheral surface of the casing and the end surface on the other side in the axial direction of the movable blade, and between the land and the end surface on the other side in the axial direction of the fixed blade. An elastic second seal disposed on the casing, and a support for the shaft attached to the casing with a gap within the range of expansion and contraction of the seal in the axial direction from the land. A rotary shock absorber that is movable in the axial direction within the range of the gap.