JPH07151183A - Sealed liquid type engine mount - Google Patents

Abstract

PURPOSE:To avoid the breakage of a member for partitioning a through-void from a fluid chamber, and prevent the bubbles from being left in the liquid in the fluid chamber. CONSTITUTION:A horizontal inner cylindrical body 1 is connected to a horizontal outer cylindrical body 2 with an elastic body 3, and an intermediate cylindrical body 4 is embedded in the elastic body close to the outer cylindrical body between the cylindrical bodies. A main fluid chamber 5 is formed to the lower side of the inner cylindrical body and a sub fluid chamber 6 is formed to the upper side respectively. A penetrating void 8 is provided to the upper part of the inner cylindrical body, and the penetrating void 8 is demarcated from the sub fluid chamber by a cylindrical wall 12 of a recessed part 4b provided on the upper side of the intermediate cylindrical body. Both fluid chambers are communicated with each other by orifices 7, 7, and the fluid 9 is sealed from an upper side opening 7a of the sub fluid chamber to the upper position to make a liquid chamber part 6a, and the upper half part is made an air chamber part 6b. A guide surface 11 which is extended diagonally upward toward the opening 7b to the lower side of the orifice with a center part 3c as the lowest point, and forms a V-shaped section is formed on the lower surface of the elastic body to demarcate the upper surface of the main fluid chamber, and bubbles contained in the liquid in the main fluid chamber are returned to the air chamber part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bush type fluid filled engine mount for supporting an automobile engine, for example.

[0002]

2. Description of the Related Art Conventionally, as a bush type fluid-filled mount, an inner cylinder and an outer cylinder are connected by an elastic body, and a fluid chamber in which liquid and air are sealed is defined inside the elastic body. Are known (for example, Japanese Patent Laid-Open No.
(See Japanese Patent Publication No. 149368). In this structure, a main fluid chamber, a sub-fluid chamber, and an orifice that connects the two fluid chambers are formed, and the liquid in the main fluid chamber receives the input vibration through the elastic body and passes through the orifice to the sub-fluid chamber. Vibration is damped by the liquid column resonance of the liquid flowing through the orifice and passing through the orifice. At this time, the air portion in the sub-fluid chamber is compressed / expanded and the volume of the liquid portion in the sub-fluid chamber is expanded / contracted.

[0003]

However, in the above-mentioned conventional bush type mount, the elastic body for connecting the inner and outer cylindrical bodies is solidly arranged in all parts other than the fluid chamber. When a large amplitude vibration is applied, a large tensile stress acts on the elastic body, and the relative displacement between the inner cylinder and the outer cylinder is limited to a relatively small amount. Therefore,
It is not suitable to apply such a mount to an engine mount that receives a relatively large amplitude and undergoes a large relative displacement.

Therefore, in order to make the bush type mount applicable as an engine mount, a through hole communicating with the atmosphere is provided in the elastic body so as to be partitioned from the sub-fluid chamber by a rubber thin film. It is also possible to reduce the tensile stress acting on the body and to cope with large displacements. However, in this case, the rubber thin film may be damaged by a large internal pressure caused by a large displacement, and is still unsuitable for an engine mount.

Further, in the case of the above bush type mount, liquid and air are enclosed in the fluid chamber, and when this is used as an engine mount, the elastic body is largely displaced and the air is contained in the liquid. It is conceivable that the mixed air bubbles will remain in the liquid. When such bubbles remain in the liquid, the flow amount of the liquid through the orifice is reduced by the amount of the bubbles, and the original vibration damping based on the liquid column resonance through the orifice cannot be exhibited.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a bush type liquid-filled mount to an engine mount by providing a through space. In order to avoid the possibility of damage to the rubber thin film that divides the through space and the fluid chamber, it is also necessary to prevent bubbles from remaining in the liquid in the fluid chamber.

[0007]

In order to achieve the above object, the present invention according to claim 1 provides an inner cylinder body having a cylinder axis arranged laterally, and an outer cylinder body surrounding the periphery of the inner cylinder body. An elastic body that connects the outer cylinder body and the inner cylinder body to each other, and an elastic body near the outer cylinder body at an intermediate position between the inner cylinder body and the outer cylinder body, and surrounds the periphery of the inner cylinder body. An intermediate cylinder body embedded like
The main fluid chamber and the sub-fluid chamber respectively defined in the elastic body at both positions in the direction orthogonal to the cylinder axis of the inner cylindrical body, the liquid and gas enclosed in both fluid chambers, and the both fluid chambers It is premised that an orifice that communicates with a through hole that penetrates through the elastic body on the sub-fluid chamber side of the inner cylinder parallel to the cylinder axis of the inner cylinder. In this configuration, the main fluid chamber is arranged on the lower side of the inner cylinder, the sub-fluid chamber is arranged on the upper side of the inner cylinder, and the liquid is placed above the opening on the sub-fluid chamber side of the orifice so that the liquid level is higher. Enclose so that it is positioned.
Then, a recessed portion that is recessed toward the inner cylindrical body is formed in the portion of the intermediate cylindrical body on the side of the sub-fluid chamber, and the through-space and the sub-fluid chamber are partitioned by the cylindrical wall that constitutes this concave portion. .

According to a second aspect of the present invention, in the first aspect of the invention, bubbles are upwardly directed toward the main fluid chamber side opening of the orifice on the lower surface of the elastic body that defines the inner upper surface of the main fluid chamber. The guide surface is formed so as to lead to.

Further, the invention according to claim 3 is based on claim 2.
In the invention described above, the orifice is formed so as to open at each position in the direction orthogonal to the cylinder axis with respect to the main fluid chamber and on both sides in the horizontal direction near the inner surface of the outer cylinder. Then, with one of the inner cylindrical body and the outer cylindrical body connected to the vibration source and the other connected to the vibration receiving portion, the guide surface of the elastic body has the horizontal intermediate portion as the lowest point, and From the point, the V-shaped cross-section is formed so that the inner angle on the upper side, which is sandwiched by the respective surfaces continuous with the main fluid chamber side opening of each of the orifices, is smaller than 180 degrees.

[0010]

With the above construction, in the invention according to claim 1,
The lower main fluid chamber and the upper sub-fluid chamber that communicates with the main fluid chamber via an orifice are filled with a liquid such that the liquid surface is located above the sub-fluid chamber side opening of the orifice. Since gas is enclosed in the upper part of the sub-fluid chamber,
The compression / expansion action of the gas allows the liquid to flow between the main fluid chamber and the sub-fluid chamber through the orifice, and the liquid column resonance of the liquid through the orifice attenuates the vibration. Since a through space is provided for damping this vibration, it is possible to cope with a large displacement without excessively increasing the tensile stress acting on the elastic body against a large amplitude vibration input. In addition, since the partition wall that partitions the through space and the sub-fluid chamber is composed of a cylindrical wall that is a rigid member that forms the recess of the intermediate cylindrical body, a conventional elastic film member such as a rubber thin film. As compared with the case of partitioning, the strength is increased, and it is possible to avoid the possibility of breakage of the partition wall even if a large internal pressure is applied by a large-amplitude vibration input. As a result, in the bush type liquid-filled mount, the through space can be provided while avoiding the risk of damage to the member defining the fluid chamber, which is suitable as an engine mount.

In addition, in the invention described in claim 2, in addition to the operation according to the invention described in claim 1, since the guide surface for guiding the bubbles upward toward the orifice is formed on the lower surface of the elastic body, the specific gravity is increased. Due to the difference, even if the air gathered above the liquid surface of the sub-fluid chamber enters the liquid and enters the main fluid chamber through the orifice, the bubbles in this main fluid chamber are guided to the guide surface and the orifice. To the main fluid chamber side opening and is discharged to the sub fluid chamber above through this orifice. Then, the bubbles rise in the liquid in the sub-fluid chamber and return to the portion where air is gathered on the liquid surface. Therefore, bubbles are prevented from remaining in the liquid in the main fluid chamber, and the original vibration damping action of the orifice is exhibited.

Further, in the invention described in claim 3, in addition to the action according to the invention described in claim 2, the guide surface of the lower surface of the elastic body has a V-shaped cross-section having an inner angle smaller than 180 degrees. Therefore, the bubbles that have entered the main fluid chamber are reliably guided to the openings of the orifices on both sides in the horizontal direction by this guide surface, and the bubbles are more reliably discharged from the main fluid chamber.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a fluid-filled engine mount according to an embodiment of the present invention, wherein 1 is an inner cylinder body arranged so that a cylinder axis X is substantially horizontal, and 2 is this inner cylinder body. 1. An outer cylinder body 3 arranged around the outer circumference of 1 to surround the outer cylinder body 3, an elastic body for connecting the outer cylinder body 2 and the inner cylinder body 1 to each other, and 4 an inner cylinder body 1 and an outer cylinder body 2. Is an intermediate cylinder body embedded in the elastic body 3 at a position close to the outer cylinder body 2 so as to surround the inner cylinder body 1. Further, 5 is a main fluid chamber defined in the elastic body 3 below the inner cylindrical body 1, 6
Is a sub-fluid chamber defined in the elastic body 3 on the upper side of the inner cylindrical body 1, 7 and 7 are orifices for communicating these two fluid chambers 5 and 6, and 8 is an upper side of the inner cylindrical body 1. It is a through space that penetrates through the elastic body 3 to change to the cylinder axis X. And
A liquid 9 as an incompressible fluid and an air 10 as a compressible gas are enclosed in the main fluid chamber 5 and the sub fluid chamber 6, and the liquid 9 is at an intermediate position in the vertical direction of the sub fluid chamber 5. Therefore, the liquid surface 9a is enclosed above the openings 7a of the orifices 7 on the sub-fluid chamber side. As a result, a liquid chamber portion 6a is formed in the lower half portion of the auxiliary fluid chamber 6, and an air chamber portion 6b is formed in the upper half portion. 1 to 3, the inner cylinder 1 is connected to the vehicle body on the vibration receiving side, and the outer cylinder 2 is connected to the engine on the vibration source, and the elastic body 3 is subjected to the weight of the engine. It shows the state.

The elastic body 3 is integrally vulcanized and molded with the inner cylindrical body 1 and the intermediate cylindrical body 4, and the outer cylindrical body is provided with a rubber thin layer 3a vulcanized and bonded on the outer peripheral side thereof. The inner cylindrical body 1 and the outer cylindrical body 2 are press-fitted to the inner peripheral surface of the second cylindrical body 2 and are connected to each other. This elastic body 3 supports the engine in an eccentric state in which the inner cylinder 1 is displaced downward relative to the outer cylinder 2 as shown by a solid line in FIG. 4 before being mounted as an engine mount to support the engine. As a result of the elastic body 3 flexing under the weight of the engine in the mounted state, the inner cylinder body 1 is positioned coaxially with the intermediate cylinder body 4 and the outer cylinder body 2 about the cylinder axis X, as shown by the chain line in the figure. To support it. A lower surface 3b of the elastic body 3 has a central portion 3c projecting downward in a direction orthogonal to the cylinder axis X and in a horizontal direction (hereinafter, referred to as a left-right direction) in a state where the own weight of the engine is applied. The lower end of the portion 3c extends diagonally upward toward the main fluid chamber side openings 7b of the orifices 7 on the left and right sides with the lower end as the lowest point.
A guide surface 11 having a substantially V-shaped cross section having an inner angle smaller than 180 degrees and sandwiched by the openings 7b around the lowest point is formed.

As shown in detail in FIG. 5, a lower portion of the outer peripheral surface of the intermediate cylinder 4 is cut out to form a window portion 4a, and an upper portion thereof is recessed inward to form a concave portion 4b. Has been formed. The main fluid chamber 5 is defined by the lower surface 3a of the elastic body 3 penetrating the window portion 4a and the inner peripheral surface of the outer cylindrical body 2 facing the lower surface 3a. The sub-fluid chamber 6 is defined by the recess 4b and the inner peripheral surface of the outer cylindrical body 2 which covers the recess 4b. in addition,
The recess 4b defines a space between the through space 8 and the sub-fluid chamber 6, and the intermediate cylindrical body 4 forming the recess 4b.
The cylindrical wall constitutes a partition wall 12 that partitions the both 8 and 6 from each other.

Each of the orifices 7 has a rubber thin layer 3a.
The portion between the main fluid chamber 5 and the sub-fluid chamber 6 is notched in the circumferential direction in the cylinder axis X direction by a predetermined width to form a concave groove shape, and the concave groove portion and the inner circumference of the outer cylindrical body 2 are formed. It is formed so as to be sandwiched between the surface and.

In FIG. 1 and FIG. 2, 3d is a stopper integrally formed with the elastic body 3 so as to project toward the through space 8, and the stopper 3d hits the bottom wall of the partition wall 12 The elastic body 3 is regulated so as not to be displaced further upward.

Next, a method of manufacturing the fluid filled engine mount having the above structure will be described with reference to FIG. 6. First, the inner cylindrical body 1 and the intermediate cylindrical body 4 are integrally vulcanized and molded with the elastic body 3 as described above. To do. Next, the integrally molded product 13 and the outer cylindrical body 2 are arranged so that the cylinder axis X is in the vertical direction, and the integrally molded product 13 is arranged from above with respect to the inner peripheral surface of the outer cylindrical body 2.
The rubber thin layer 3a on the outer peripheral surface is press-fitted, and the above-mentioned press-fitting is performed with a gap 15 opened between the upper end of the cavity 14 serving as the main fluid chamber 5 and the upper end opening edge 2a of the outer cylindrical body 2. Pause.
Then, the liquid 9 is injected from the gap 15 by a predetermined amount in consideration of the amount of air in the air chamber portion 6b, and then the integrally molded product 13 is press-fitted to the end. Finally, the upper and lower opening edges 2a and 2b of the outer cylindrical body 2 are caulked to integrate the both 13 and 2. According to this manufacturing method, since it is not necessary to assemble in a liquid tank filled with the liquid 9, there is no need to generate the liquid due to press fitting or to wash the liquid attached to the outer surface after the assembly. Further, even when the liquid 9 is injected outside the liquid tank by vacuum suction, even if micro bubbles are generated in the liquid 9, they enter the air 10 of the air chamber portion 6b, so that the attenuation due to the remaining micro bubbles. The deterioration of performance can be eliminated, and the tact time at the time of manufacturing can be shortened.

Next, the operation and effect of the embodiment having the above structure will be described below.

When vertical vibration is input to the elastic body 3 via the outer cylindrical body 2, the inner cylindrical body 1 is relatively displaced in the vertical direction. Due to this displacement, the liquid 9 flows between the main fluid chamber 5 and the liquid chamber portion 6a of the auxiliary fluid chamber 6 through both orifices 7, 7. Then, this flow causes liquid column resonance through the both orifices 7, 7, and the liquid column resonance attenuates the vibration. When the liquid 9 flows, the liquid 9 is discharged to the sub-fluid chamber 6 side and the sub-fluid chamber side opening 7a of each orifice 7 is formed.
Since the liquid chamber portion 6a and the air chamber portion 6b are provided so as to be sealed up to a higher position, the flow of the liquid 9 through the orifices 7 is caused by the compression / expansion action of the air 10 in the air chamber portion 6b. It will be possible.

At the time of inputting the vibration, since the through space 8 exists above the elastic body 3, the tensile stress of the elastic body 3 does not become excessively large even if the input vibration has a large amplitude. It can be displaced to a large extent and can exert its function as an engine mount. Further, even if the above-mentioned large-amplitude vibration is input and the hydraulic pressure increases, the liquid chamber portion 6a of the sub-fluid chamber 6 is defined by the partition wall 12 which is a part of the intermediate tubular body 4 and is almost rigid. Therefore, the strength of the member (partition wall 12) that defines the sub-fluid chamber 6 can be dramatically increased compared to the case where it is defined by an elastic film member such as a rubber thin film. It is possible to avoid the risk of damage due to. Therefore, in the bush type engine mount, the through space 8 can be provided without any trouble.

Even if the air 10 in the air chamber portion 6b of the sub-fluid chamber 6 is mixed in the liquid 9 and the air bubbles enter the main fluid chamber 5 through the orifices 7 as the liquid 9 flows,
The bubbles rise in the liquid 9 in the main fluid chamber 5 and rise to the guide surface 11
The guide surface 11 guides each orifice 7
To the sub-fluid chamber 6 through the orifices 7 of the main fluid chamber. Since the bubbles rise in the liquid 9 in the liquid chamber 6a and are naturally returned to the air chamber 6b, it is possible to reliably prevent the bubbles from remaining in the liquid 9 in the main fluid chamber 5. As a result, the desired vibration damping performance via the above-mentioned orifices 7 can be maintained.

The present invention is not limited to the above embodiment, but includes various other modifications. That is, in the above embodiment, the elastic body 3 is used as the guide surface.
Although the guide surface 11 having a function of a stopper that protrudes downward from the central portion 3c of the lower surface and contacts the inner peripheral surface of the outer cylindrical body 2 when displaced downward is shown, the guide surface 11 is not limited to this, and the left and right sides sandwiching the lowest point are shown. It suffices if the cross-sectional shape of the surfaces is V-shaped. For example, the left and right surfaces sandwiching the lowest point may be flat surfaces or curved surfaces that are convex downward or upward.

Further, in the above-mentioned embodiment, the concave portion 4b defining the sub-fluid chamber 6 is formed in a groove shape extending in the left-right direction, but the present invention is not limited to this, and may be formed in a concave shape, for example.

Further, in the above embodiment, the air 10 is enclosed as the gas to be enclosed in the fluid chamber. However, the present invention is not limited to this. Any material that allows the liquid 9 to flow to and from the chamber 6 may be used, and for example, nitrogen gas may be used.

Further, in the above-mentioned embodiment, the outer cylinder 2 is connected to the engine side and the inner cylinder 1 is connected to the vehicle body side. However, the invention is not limited to this. The inner cylinder 1 may be connected to the vehicle body side and to the engine side.
In this case, the elastic body may be configured so that the inner cylindrical body is supported in a state of being eccentrically relatively upward with respect to the outer cylindrical body in a state before being connected.

[0028]

As described above, according to the fluid filled engine mount of the first aspect of the present invention, the lower main fluid chamber and the upper sub fluid communicated with the main fluid chamber through the orifice. Liquid is enclosed in the chamber so that the liquid surface is located above the opening of the orifice on the side of the sub-fluid chamber, and gas is enclosed in the upper part of the sub-fluid chamber, so that the compression / expansion action of the gas As a result, the liquid can flow between the main fluid chamber and the sub-fluid chamber through the orifice, and the vibration of the liquid can be damped by the liquid column resonance of the liquid through the orifice.

Since a through space is provided for damping this vibration, it is possible to cope with a large displacement without excessively increasing the tensile stress acting on the elastic body against a large-amplitude vibration input. In addition, since it is configured by a cylindrical wall that is a rigid member that configures the concave portion of the intermediate tubular body as a partition wall that partitions the through space and the sub-fluid chamber, an elastic film member such as a conventional rubber thin film is used. The strength can be increased as compared with the case of partitioning, and the risk of breakage of the partition wall can be avoided even if a large internal pressure is applied by a large-amplitude vibration input.
As a result, in the bush type liquid-filled mount, it is possible to provide the through space while avoiding the risk of damage to the member defining the fluid chamber, and it is possible to use the mount as a suitable engine mount.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, a guide surface for guiding the bubbles upward to the main fluid chamber side opening of the orifice is formed on the lower surface of the elastic body. Therefore, even if bubbles enter the liquid in the lower main fluid chamber due to large-amplitude vibration input, the bubbles are guided to the orifice by the guide surface and the gas in the sub-fluid chamber passes through this orifice. You can return to the part. As a result, it is possible to reliably prevent bubbles from remaining in the liquid in the main fluid chamber, and it is possible to reliably exhibit the original vibration damping action of the orifice.

Further, according to the invention of claim 3, in addition to the effect of the invention of claim 2, the guide surface of the lower surface of the elastic body has a V-shaped cross section having an inner angle smaller than 180 degrees. Since it has a shape, it is possible to reliably guide the bubbles that have entered the main fluid chamber to the openings of either of the orifices on both sides in the horizontal direction by the guide surface, and prevent the bubbles from remaining in the main fluid chamber. It can be done reliably.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention.

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

FIG. 3 is a sectional view taken along line BB in FIG.

FIG. 4 is a view corresponding to FIG. 1 in a state before mounting.

FIG. 5 is an exploded perspective view of an inner cylinder and an intermediate cylinder.

FIG. 6 is a vertical sectional view showing an assembling procedure.

[Explanation of symbols]

 1 inner cylinder 2 outer cylinder 3 elastic body 3c central part (horizontal intermediate part) 4 intermediate cylinder 5 main fluid chamber 6 sub fluid chamber 7 orifice 7a sub fluid chamber side opening 7b main fluid chamber side opening 8 through space 9 liquid 9a liquid surface 10 air (gas) 11 guide surface 12 partition wall X cylinder axis

Claims (3)

[Claims] 1. An inner cylinder body having a cylinder axis arranged laterally, an outer cylinder body surrounding the inner cylinder body, an elastic body connecting the outer cylinder body and the inner cylinder body to each other, An intermediate cylinder body embedded in an elastic body near the outer cylinder body at an intermediate position between the inner cylinder body and the outer cylinder body so as to surround the periphery of the inner cylinder body, and a direction orthogonal to a cylinder axis of the inner cylinder body. The main fluid chamber and the sub-fluid chamber respectively defined in the elastic body at both sides of the, the liquid and gas enclosed in both fluid chambers, the orifice for communicating the two fluid chambers with each other, and the sub-subunit from the inner cylindrical body. In a fluid filled engine mount having a through space penetrating through the elastic body on the fluid chamber side in parallel to the cylinder axis of the inner cylinder, the main fluid chamber is below the inner cylinder, and the auxiliary fluid is The chambers are arranged on the upper side of the inner cylinder, respectively, and the liquid is located above the opening of the orifice on the side of the sub-fluid chamber. It is sealed so as to be positioned, and a recessed portion that is recessed toward the inner cylindrical body is formed at a portion of the intermediate cylindrical body on the side of the sub-fluid chamber. A fluid filled engine mount that is characterized by: 2. The fluid sealing according to claim 1, wherein a guide surface that guides bubbles upward toward the main fluid chamber side opening of the orifice is formed on the lower surface of the elastic body that defines the inner upper surface of the main fluid chamber. Type engine mount. 3. The inner cylinder according to claim 2, wherein the orifice is formed so as to open in each position in the direction orthogonal to the cylinder axis with respect to the main fluid chamber and on both sides in the horizontal direction near the inner surface of the outer cylinder. With one of the body and the outer cylinder connected to the vibration source and the other connected to the vibration receiver, the guide surface of the elastic body is
The horizontal intermediate portion is defined as the lowest point, and a V-shaped cross-sectional shape is formed so that the inner angle of the upper side sandwiched by the respective surfaces continuing from the lowest point to the main fluid chamber side openings of the orifices becomes smaller than 180 degrees. Formed fluid filled engine mount.