JP2000065121A - Fluid charged vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid charged vibration control device having an excellent vibration absorption at high frequency range by improving vehicular comfortableness, and securing proper attenuation to vibration input in bilateral directions. SOLUTION: This device comprises a stopper 20 fixed to an inner cylindrical metal fitting 10 and projecting toward both sides in a radial direction, a ring spacedly coaxially disposed on an outer peripheral side of the inner cylindrical metal fitting 10 and provided at both ends in an axial direction, an intermediate metal fitting having a pair of connections 32 connecting the ring, a sidewall connecting the ring to the inner cylindrical metal fitting 10, an elastic rubber body having arms 42 extending axially to connect the connections 32 to the inner cylindrical metal fitting 10, and an outer cylindrical metal fitting 50 fixed to an outer periphery of the intermediate cylindrical metal fitting via a thin rubber seal 51. A pair of through openings 43 are provided to penetrate axially, and penetrate through the sidewall in an extending direction. A projection 22 is provided to project substantially in parallel with the arm 42 on each side in the peripheral direction of a tip of the stopper 20. A tip of the projection 22 is in the same position as or outside the outer end in the radial direction of the through opening 43 provided at the arm 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid filled type vibration damping device.

[0002]

2. Description of the Related Art Conventionally, as this type of liquid-filled type vibration damping device, for example, as shown in FIGS.
And a rod-shaped stopper member 2 fixed to the outer peripheral surface of the inner cylindrical fitting 1 and protruding radially on both sides, and disposed coaxially at a distance from the outer peripheral side of the inner cylindrical fitting 1 at a pair of axially opposite ends. A substantially cylindrical intermediate metal fitting 3 having a pair of ring parts 3a, a pair of ring parts 3a connected to each other, and a pair of connecting parts 3b provided on both radial positions orthogonal to the stopper member 2; A pair of side walls 4a connecting the ring portion 3a and the inner cylinder 1 and a pair of arms 4b extending in the axial direction between the pair of side walls 4a to connect the pair of connection 3b and the inner cylinder 1 to each other.
A rubber elastic body 4 having a substantially cylindrical shape and a coaxially disposed rubber seal portion 5a on the outer peripheral side of the intermediate metal fitting 3 so as to close the outer peripheral portion of the intermediate metal fitting 3 in a liquid-tight manner. 4a
And a pair of liquid chambers 6 surrounded by the arms 4b,
There is known an apparatus provided with an outer tube fitting 5 forming an orifice passage 7 for communicating the two liquid chambers 6 with one connecting portion 3b.

In this liquid-filled type vibration damping device, for example, both arms 3b are arranged in the front-rear direction of the vehicle and both liquid chambers 5a are arranged in the left-right direction in a state in which the inner cylindrical fitting 1 is oriented vertically. Then, the inner cylinder 1 is connected to a support member (not shown) on the lower arm side of the vehicle, and the outer cylinder 5 is connected to a support member (not shown) on the vehicle body. With respect to the vibration input in the left and right direction of the vehicle, the vibration is attenuated by the liquid column resonance effect caused by the liquid in both liquid chambers 6 flowing through the orifice passage 7. At this time, if excessive vibration is transmitted, both distal end surfaces of the stopper member 2 come into contact with the inner wall surface of the outer tube fitting 5, thereby suppressing vibration displacement. Further, with respect to the vibration input in the front-rear direction of the vehicle, the vibration is attenuated by the rubber elastic action caused by the arm portion 3b expanding and contracting in the front-rear direction.

[0004]

However, the liquid filled type vibration damping device has a high dynamic spring constant in the front-rear direction of the vehicle, so that the ride comfort of the vehicle is poor. Needs springing. For this purpose, as shown in, for example, Japanese Utility Model Publication No. 2-36986, through holes are provided in both arms so as to penetrate in the axial direction, thereby reducing the dynamic spring constant of the arms and improving the ride comfort of the vehicle. Methods are known. However, the provision of the through-hole in the arm portion lowers the rigidity of the arm portion, thereby lowering the efficiency of the liquid discharge piston, and may impair the damping performance of the vehicle against vibration input in the left-right direction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a low dynamic spring constant in the longitudinal direction of the vehicle to improve the riding comfort of the vehicle, and has a proper damping performance for vibration input in the lateral direction. It is another object of the present invention to provide a liquid-sealed type vibration damping device having excellent vibration absorption characteristics in a high frequency range.

[0006]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the structural features of the invention described in claim 1 above are characterized in that the inner cylinder is fixed to an outer peripheral surface of the inner cylinder. A stopper member protruding to both sides in the radial direction and being disposed coaxially at a distance outside the inner cylindrical fitting, having a pair of ring portions at both axial end positions, connecting the pair of ring portions, and A substantially cylindrical intermediate metal fitting having a pair of connecting parts provided at both radial positions substantially orthogonal to the projecting direction of the member, and a pair of side wall parts connecting between the pair of ring parts and the inner cylindrical metal part. A substantially cylindrical rubber elastic body having a pair of connecting portions and a pair of arms connecting the inner cylindrical fittings extending in the axial direction between the pair of side wall portions, and a thin rubber seal portion on the outer periphery of the intermediate fittings. And an outer peripheral portion of the intermediate fitting is liquid-tightly closed to form a pair of side wall portions. A liquid-sealing prevention device comprising: a pair of liquid chambers formed in a space between the pair of arms; and an outer metal fitting forming an orifice passage communicating between the pair of liquid chambers and the connecting portion. In the vibration device, a pair of through-holes are provided in the pair of arms so as to penetrate in the axial direction and extend through the side walls in the extending direction thereof, and are substantially parallel to the arms on both circumferential sides of both end portions of the stopper member. And a protruding portion that protrudes with a gap between the inner wall surface of the outer cylinder and the protruding portion. That is, the outer position.

According to the first aspect of the present invention, when the vehicle is subjected to vibration in the left-right direction, the liquid in the liquid chamber is applied to the tip end surface of the stopper member having projections at both ends in the circumferential direction. By being pushed and efficiently flowing into the orifice passage along the inner wall surface of the outer cylinder fitting and smoothly flowing between the liquid chambers, the liquid column resonance action in the orifice passage is effectively exhibited and vibration is attenuated. it can. Therefore, it is possible to suppress a decrease in the efficiency of the liquid discharge piston due to a decrease in the rigidity of the arm portion due to the provision of the through hole, and it is possible to secure a damping performance equal to or higher than that without the through hole. Also,
By providing through holes in each arm and side wall, a low dynamic spring in the vehicle front-rear direction is achieved, and the riding comfort of the vehicle can be improved. Furthermore, with respect to vibration in a high-frequency region, the hydraulic pressure generated by the vibration is absorbed more efficiently by deformation of the thin rubber portion around which the through-hole is formed, compared to the case where no through-hole is provided. Therefore, an increase in the dynamic spring constant can be suppressed.

As a result, according to the first aspect of the present invention, it is possible to improve the riding comfort of the vehicle by lowering the dynamic spring constant in the longitudinal direction of the vehicle, and to appropriately secure the damping performance with respect to the vibration input in the lateral direction. Is done. Also, excellent vibration absorption characteristics can be obtained in a high frequency range.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 5 are partially cutaway plan views showing a liquid-filled type vibration damping device for a vehicle according to the embodiment. It is shown by a side view, a partially cutaway front view, a sectional view perpendicular to the axis, and a sectional view in the axial direction.

The liquid-filled type vibration damping device has an inner cylindrical fitting 10 which is a pipe-shaped fitting, and a stopper member 20 projects radially on both sides in the axial middle position of the outer wall surface of the inner cylindrical fitting 10. It is provided. The stopper member 20 is made of resin and has a substantially rectangular column shape having an axial width smaller than the width in the direction perpendicular to the axis, as shown in FIGS. Has a convex curved surface shape corresponding to the inner wall surface. On both sides in the circumferential direction of both end portions of the stopper member 20, there are provided protruding portions 22 protruding while maintaining a curved shape in a direction perpendicular to both side surfaces and continuously to the end surface 21. The cross section perpendicular to the axis has a bulk shape.

The stopper member 20 is formed on the outer peripheral surface of the inner cylindrical member 10 by integral molding with resin. As a molding die (not shown) used for molding, it is possible to use a molding die having a structure in which its mating surface is aligned with the central axis of the inner cylinder fitting 10 in a direction perpendicular to the axis. By setting and performing resin integral molding, the stopper member 20 can be formed with high productivity and at low cost. The mounting of the stopper member 20 to the inner cylindrical member 10 is not limited to this, and the stopper member 20 formed in advance may be fitted to the outer peripheral surface of the inner cylindrical member 10 and fixed. Also, the material of the stopper member 20 is not limited to resin, and aluminum or the like can be used. A cylindrical intermediate fitting 30 is coaxially disposed on the outer peripheral side of the inner cylindrical fitting 10 including the stopper member 20.

The intermediate fitting 30 is made of a thin metal plate, and is shown in FIG.
As shown in FIG. 2, a pair of ring portions 31 having a predetermined width coaxially located on both sides in the axial direction, and both ring portions being disposed between the two ring portions 31 in an axially parallel and symmetrical position in the radial direction. And a pair of long plate-shaped connecting portions 32 for integrally connecting the connecting portions 31 to each other. The connecting portion 32 is slightly reduced in diameter with respect to the ring portion 31, and the two window portions 33 arranged in the circumferential direction between the ring portions by partitioning between the ring portions 31.
Is formed. The intermediate fitting 30 is arranged such that the two connecting portions 32 are located at both radial positions orthogonal to the projecting direction of the stopper member 20.

As shown in FIGS. 2, 4 and 5, the rubber elastic body 40 has a pair of thick side walls 41 connecting the ring portion 31 and the inner cylindrical member 10 over substantially the entire circumference in the direction perpendicular to the axis.
And a plate-like arm 42 extending in the axial direction between the pair of side wall portions 41 and connecting between the pair of connecting portions 32 and the inner cylinder fitting 10. The arm portion 42 is provided with a through hole 43 that penetrates in the axial direction at a radially intermediate position and also penetrates the side wall portion 41 in the extension direction. On the outer surface of the connecting portion 32, a thin portion 42a in which a part of the connecting portion 32 wraps is fixed, and one thin portion 42a is inclined at a predetermined angle with respect to the circumferential direction between both circumferential ends. A groove 44a is provided.

Here, the arm 42 is connected to the stopper member 2.
The protrusions 22 are substantially parallel to the protrusions 22 of the first through-holes, and as shown in FIG. 4, the tips of the protrusions 22 are formed so as to be located outside the radially outer ends of the through holes 43. I have. However, the tip of each protrusion 22 may be located at the same position with respect to the radially outer end of the through hole 43.

For the formation of the rubber elastic body 40, a molding die (not shown) which is matched with the molding die for forming the stopper member 20 is used. By performing vulcanization molding in a state where the inner cylinder fitting 10, the stopper member 20 and the intermediate fitting 30 are set in this molding die, it is integrally molded as a rubber vulcanized molded product (not shown) as an intermediate product. In addition, no burr is formed on the inner surface of the groove portion 44a because no mold matching surface is disposed, and therefore, no obstacle is formed on a passage of the orifice passage 44 described later formed by the groove portion 44a. The liquid flows smoothly, and does not hinder the liquid column resonance operation of the liquid-filled type vibration damping device.

The outer tube fitting 50 is a thin-walled large-diameter metal pipe, and a thin-walled rubber seal portion 51 is attached to the inner wall surface by vulcanization molding. As shown in FIGS. 3 and 4, the outer cylinder fitting 50 is provided on the outer periphery of the rubber vulcanized molded product via the rubber seal portion 51, and is fixed to the intermediate fitting 30 by drawing. Thus, the space surrounded by the pair of side walls 41 and the arms 42 is liquid-tightly closed to form a pair of liquid chambers 52. The groove 44
orifice passage 4 connecting between the two liquid chambers 52
4 are provided. Water is sealed in the two liquid chambers 52 and the orifice passage 44 as a liquid. In this case, the method of sealing the water is as follows. The rubber vulcanization molded product and the outer cylinder fitting 50 are immersed in a liquid tank filled with water, and the rubber vulcanization molded product is inserted into the outer cylinder fitting 50 in this state, and This is performed by subjecting the tube fitting 50 to drawing. Here, water is used as the liquid to be sealed, but the present invention is not limited to this, and another incompressible fluid such as alkylene glycol or silicone oil may be sealed. Note that the rubber seal portion 51 is attached to the inner wall surface of the outer cylinder fitting 50, but is not limited thereto, and may be fixed to the outer surfaces of both ring portions 31 in advance.

In the liquid filled type vibration damping device constructed as described above, for example, both arms 42 are oriented in the front-rear direction of the vehicle, with the inner cylinder fitting 10 oriented vertically, and the two liquid chambers are arranged. Reference numeral 52 denotes a left and right direction, the inner cylindrical member 10 is connected to a support member (not shown) on the lower arm side of the vehicle, and the outer cylindrical member 50 is connected to a support member (not shown) on the vehicle body.
Linked to

When a vibration input in the left-right direction of the vehicle is applied, the liquid in the liquid chamber 52 is protruded at both ends in the circumferential direction.
Is pushed by the tip end surface 21 of the stopper member 20 provided with the liquid, flows along the inner wall surface of the outer cylinder fitting 50, efficiently flows into the orifice passage 44 without being hindered by the arm portion 42, and flows into the two liquid chambers 52.
It flows smoothly between the spaces. Therefore, the liquid column resonance action in the orifice passage 44 is efficiently performed, and the vibration input in the left-right direction can be attenuated. As a result, the through hole 4
3 can suppress a decrease in the efficiency of the liquid discharge piston due to a decrease in the rigidity of the arm portion 42, and can attain a damping performance equal to or higher than the case where the through hole 43 is not provided. Further, with respect to vibration input in the longitudinal direction of the vehicle, a through hole 43 is formed in each arm 42.
The vibration is attenuated by the rubber elastic action of the arm portion 42 extending and contracting in the front-rear direction since the vehicle front-rear direction is reduced by the provision of the elastic member. Further, with respect to the vibration in the high-frequency region, the liquid pressure generated by the vibration is absorbed more efficiently than the case where the through-hole 43 is not provided, because the thin rubber portion around the through-hole 43 is deformed. .

As a result, according to the above-described embodiment, the ride comfort of the vehicle can be improved by lowering the dynamic spring constant in the vehicle front-rear direction, and the damping performance for the vibration input in the left-right direction can be properly secured. . Also, excellent vibration absorption characteristics can be obtained in a high frequency range.

The specific structure and the like of the liquid filled type vibration damping device shown in the above embodiment is not limited to this.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view schematically showing a liquid-filled type vibration damping device according to an embodiment of the present invention.

FIG. 2 is a side view schematically showing the liquid filled type vibration damping device.

FIG. 3 is a partially cutaway front view schematically showing the liquid filled type vibration damping device.

FIG. 4 is a sectional view taken along line IV-IV shown in FIG. 3;

FIG. 5 is a sectional view taken along line VV shown in FIG.

FIG. 6 is a cross-sectional view in a direction perpendicular to an axis of a liquid filled type vibration damping device according to a conventional example.

FIG. 7 is a sectional view taken along line VII-VII shown in FIG.

[Explanation of symbols]

10 ... inner cylinder fitting, 20 ... stopper member, 21 ... tip surface,
22: Projection, 30: Intermediate fitting, 31: Ring, 32
... connecting portion, 40 ... rubber elastic body, 41 ... side wall portion, 42 ... arm portion, 42a ... thin portion, 43 ... through hole, 44 ... orifice passage, 44a ... groove portion, 50 ... outer cylinder fitting, 51 ... rubber seal portion, 52 ... liquid chamber.

Claims (1)

[Claims] 1. An inner cylinder, a stopper member fixed to an outer peripheral surface of the inner cylinder and projecting radially on both sides, and coaxially disposed outside the inner cylinder to be spaced apart from the inner cylinder. A substantially cylindrical shape having a pair of ring portions at both end positions, connecting the pair of ring portions, and having a pair of connecting portions provided at both radial positions substantially orthogonal to a direction in which the stopper member protrudes. An intermediate metal fitting, a pair of side wall parts connecting the pair of ring parts and the inner cylindrical metal part, and an axial direction extending between the pair of side wall parts to connect the pair of connecting parts and the inner cylindrical metal part. A rubber elastic body having a substantially cylindrical shape having a pair of arms to be fixed to the outer periphery of the intermediate fitting via a thin rubber seal portion, and closing the outer peripheral portion of the intermediate fitting in a liquid-tight manner. Forming a pair of liquid chambers in a space between the side wall and the pair of arms; An outer cylinder fitting that forms an orifice passage communicating between the pair of liquid chambers with the connecting portion. Providing a pair of through holes penetrating the side wall portion in the extension direction,
At both ends in the circumferential direction of both end portions of the stopper member, projecting portions are provided substantially parallel to the arm portion and projecting from the inner wall surface of the outer cylinder with a gap therebetween, and the tip of the projecting portion is provided. A liquid-filled type vibration damping device, wherein the position is the same as or outside the radially outer end of a through hole provided in the opposed arm.