JPH0777235A - Liquid sealed vibration isolator - Google Patents

Abstract

PURPOSE:To secure a good a vibro-damping chracteristic at all times as a throttle passage is not closed by a stopper member. CONSTITUTION:A vibrationproof rubber body 3 piercingly supporting an inner cylinder 2 and formed with a main liquid chamber, two sub liquid chambers B and C making each of freely deformable thin rubber walls 41 and 42 as a chamber wall, and a throttle passage F connecting the main liquid chamber and the sub liquid chamber B are all installed in an inner space of an outer cylinder 1. A stopper member 5, where the inner cylinder 2 comes into contact and its excess displacement is restricted, is installed in the main liquid chamber, while a projecting wall 47 projecting toward an end face 51 of the stopper member 5 is installed in the edge of an opening 44 leading to the main liquid chamber of the throttle passages F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid filled vibration damping device,
Particularly, the present invention relates to a structural improvement of a tubular liquid-filled vibration isolator in which a vibration-proof rubber body having a liquid chamber is arranged between inner and outer double cylinders.

[0002]

2. Description of the Related Art A cylindrical vibration damping device has been proposed as a liquid filled vibration damping device that exhibits a good vibration damping action in a compact shape and is suitable for use in engine mounts and the like. 5 shows.

In the figure, an anti-vibration rubber body 3 is joined in the upper half of a cylindrical insert plate 6 press-fitted in an outer cylinder 1, and an inner cylinder 2 for connecting and supporting the vibrating body is penetratingly embedded near the bottom wall thereof. I am doing it. The anti-vibration rubber body 3 is formed as a main liquid chamber A by leaving the front and rear (vertical direction of the plane of the drawing) side walls and recessing the central portion from the outer peripheral surface of the upper half to near the inner cylinder 2. The insert plate 6 is recessed at the center of the outer circumference, and a ring-shaped throttle member 71 is disposed in this portion. In the lower half portion 61 of the insert plate 6 which is further recessed, the throttle member 71 is provided.
The outer periphery of the thin-walled rubber wall 72 is sandwiched between the opening edges of the openings formed in the upper side, the sub-liquid chamber B is formed above the thin rubber wall 72, and the lower side is the air chamber D.
Has become.

The main liquid chamber A and the sub liquid chamber B are communicated with each other by a throttle channel F formed in the throttle member 71.
Inside the fan-shaped main liquid chamber A, a stopper member 5 having a shape substantially similar to this is arranged, and below the bottom wall of the vibration-proof rubber body 3 through which the inner cylinder 2 penetrates, a cushioning rubber plate 73 is arranged. .

When vibration is input and the vibration-proof rubber body 3 is deformed, the enclosed liquid flows between the main liquid chamber A and the sub-liquid chamber B through the throttle channel F, and a large vibration damping force is generated.

[0006]

By the way, when the inner cylinder 2 is largely displaced upward, it abuts on the stopper member 5 provided in the main liquid chamber A, and further excessive displacement is restricted.
The stopper member 5 must not reverse its posture when the main liquid chamber A is deformed due to the vertical movement of the inner cylinder, and in order to avoid stress concentration and to perform a reliable stopper action. It is necessary to secure the areas of the inner peripheral surface and the outer peripheral surface that contact the inner cylinder 2 and the outer cylinder 1 as wide as possible. Therefore, as shown in the drawing, the throttle member 71 has a fan shape along the inner wall of the main liquid chamber A, which substantially matches the shape when the liquid chamber is contracted.

However, as a result of providing the stopper member 5 having such a shape, when the main liquid chamber A contracts and the enclosed liquid flows out into the throttle flow passage F, the stopper member 5 moves toward the opening 74 of the throttle flow passage F. Is sucked in and blocks part or all of the opening 74,
There is a problem that the device characteristics change suddenly.

The present invention solves such a problem, and provides a liquid-filled anti-vibration device capable of always obtaining a good vibration damping characteristic without the throttle channel being blocked by a stopper member. To aim.

[0009]

The structure of the present invention will be described. A vibration-proof rubber body 3 having an inner cylinder 2 penetratingly supported in an inner space of an outer cylinder 1 and a main liquid chamber A formed therein, and freely deformable. In the liquid-filled anti-vibration device provided with auxiliary liquid chambers B and C having possible thin rubber walls 41 and 42 as chamber walls, and a throttle channel F connecting the main liquid chamber A and the auxiliary liquid chamber B, In the liquid chamber A, a stopper member 5 is provided which is in contact with the inner cylinder 2 and whose excessive displacement is restricted, and the edge of the opening 44 of the throttle channel F to the main liquid chamber A or the stopper facing the edge. The projecting walls 47 and 48 projecting in the facing direction are provided on any of the surfaces 51 of the member 5.

[0010]

In the above structure, when the main liquid chamber A contracts due to the vibration input and the enclosed liquid flows out from the throttle channel F, the stopper member 5 is attracted to the opening 44 of the throttle channel F and approaches. Before the surface of the stopper member 5 contacts the opening 44,
The projecting walls 47 and 48 provided on the surface of the stopper member or on the edge of the throttle channel opening 44 abut on each other and the stopper member 5
A gap is secured between the aperture and the throttle channel opening 44. Wall 4
By appropriately setting the heights of 7, 48, the cross section of the gap can be ensured to be larger than the cross section of the throttle channel F, and the flow of the enclosed liquid in the throttle channel F is surely ensured.

[0011]

[Embodiment 1] In FIG. 1, a cylindrical insert plate 6 is press-fitted and fixed in a circular outer cylinder 1, and the insert plate 6 is recessed at the center of the outer periphery thereof so that a gap is formed between the insert plate 6 and the inner periphery of the outer casing 1. Is forming. The anti-vibration rubber body 3 is injection-molded in the upper half of the insert plate 6, and the inner cylinder 2 for connecting and supporting the vibrating body is embedded in the center near the bottom wall thereof. The anti-vibration rubber body 3 is recessed from the outer periphery of the upper half to the vicinity of the inner cylinder 2 except the front and rear side walls to form a recess 31. This recess 31 is formed in an opening provided on the peripheral surface of the insert plate 6. They coincide with each other and are closed by the outer cylinder 1 to form a main liquid chamber A.

A rubber material is also injection-molded at the center of the outer periphery of the insert plate 6 to form a rubber layer 4 over the entire periphery. The rubber layer 4 is further deeply recessed to approach the inner cylinder 2. As it becomes thicker in the concave part 61 of
Except for the center, the openings provided at the left and right positions of the recess 61 are recesses in which the thin rubber walls 41 and 42 are left. These recesses are closed by the outer cylinder 1 to form left and right sub-liquid chambers B and C having thin rubber walls 41 and 42 as chamber walls. These sub-liquid chambers B and C are provided in the central rubber block 46. The formed large-diameter flow paths 45 communicate with each other to form a substantially integrated liquid chamber.

A groove 43 is formed on the outer periphery of one side of the rubber layer 4 so that the upper end reaches the main liquid chamber A and the lower end reaches the sub liquid chamber B, and both of them are closed by the outer cylinder 1. Liquid chamber A, B
Is a narrowed flow path F that communicates with each other.

At the edge of the opening 44 to the main liquid chamber A of the throttle channel F, a projecting wall 47 extending vertically along the inner wall of the recess 31 is located at the front and rear (upper and lower in FIG. 2) positions with the opening 44 interposed therebetween. , 48 are formed. Then, in the main liquid chamber A, a substantially fan-shaped resin stopper member 5 is inserted along the inner wall of the liquid chamber A as described in the conventional example (FIG. 5), and one end surface 51 thereof is placed.
Faces the opening 44 of the throttle channel F.

In this structure, when vibration is input and the inner cylinder 2 moves up and down, the volume of the main liquid chamber A expands and contracts accordingly, and the enclosed liquid passes through the throttle channel F and the sub liquid chamber B below. To generate a large vibration damping force. At this time, the main liquid chamber A
The stopper member 5 moves toward the opening 44 of the throttle channel F and approaches as the filled liquid flows out from the stopper member 5.

Here, the end surface of the stopper member 5 approaching the opening 44 contacts the projecting walls 47 and 48 projecting from both side edges of the opening 44, and in this state, a gap is formed between the projecting walls 47 and 48. . If the height of the protruding walls 47, 48 is set appropriately, the gap formed at this time becomes sufficiently large to ensure the inflow of the enclosed liquid into the throttle channel F.

[0017]

[Embodiment 2] In the above embodiment, the projecting wall is provided at the opening edge of the throttle channel, but as shown in FIGS. 3 and 4, the same effect can be obtained by providing it on the stopper member. That is, in one end surface 51 of the stopper member 5 facing the opening of the throttle channel, a vertically extending concave groove 54 is formed in the center, and the remaining front and rear side portions are projecting walls 52 and 53. .

In this case as well, the height of the protruding walls 52, 53, that is, the depth or width of the recessed groove 54 is appropriately set so that the protruding walls 52, 53 are in contact with the edge of the opening 44. , A sufficient gap is secured between the opening 44 and the stopper member end surface 51, and the reliable flow of the enclosed liquid into the throttle channel F is guaranteed.

[0019]

As described above, according to the liquid-filled vibration damping device of the present invention, the stopper member inserted into the main liquid chamber does not cause a problem that the throttle passage is blocked to change the device characteristics, and the vibration is always good. Exhibits a damping effect.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view of a liquid filled vibration damping device according to an embodiment of the present invention.

FIG. 2 is a plan view of the liquid filled vibration damping device with an outer cylinder removed.

FIG. 3 is a sectional view of a stopper member showing another embodiment of the present invention.

FIG. 4 is a plan view of the stopper member as seen from below.

FIG. 5 is an overall transverse sectional view of a conventional liquid filled vibration damping device.

[Explanation of symbols]

 1 Outer cylinder 2 Inner cylinder 3 Anti-vibration rubber body 4 Rubber layer 41, 42 Thin rubber wall 44 Opening 47, 48 Projection wall 5 Stopper member 51 End surface (surface) 52, 53 Projection wall A Main liquid chamber B, C Sub liquid chamber F throttle channel

Claims (1)

[Claims] 1. An anti-vibration rubber body having a main liquid chamber formed therein by penetratingly supporting the inner cylinder in an inner space of the outer cylinder, and a sub liquid chamber having a freely deformable thin rubber wall as a chamber wall, In a liquid filled vibration damping device provided with a throttle channel connecting a main liquid chamber and a sub liquid chamber, in the main liquid chamber, a stopper member is provided to prevent an excessive displacement of the inner cylinder by contacting the inner cylinder. A liquid-filled anti-vibration device, characterized in that a protruding wall protruding in the facing direction is provided on either the opening edge of the throttle channel to the main liquid chamber or the surface of the stopper member facing the opening edge.