JP2603798B2 - Fluid-filled engine mount - Google Patents

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, for example, an automobile engine.

[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 inside the elastic body is defined. Are known (see, for example,
-149368). In this device, a main fluid chamber, a sub-fluid chamber, and an orifice communicating with both fluid chambers are formed, and the liquid in the main fluid chamber receives the input vibration through the elastic body and the sub-fluid chamber through the orifice. And vibration is attenuated by the liquid column resonance of the liquid passing through the orifice. At this time, the air portion in the sub-fluid chamber is compressed and expanded, and the volume of the liquid portion in the sub-fluid chamber is expanded and contracted.

[0003]

However, in the above-mentioned conventional bush type mount, since the elastic body for connecting the inner and outer cylinders is disposed solidly in all parts other than the fluid chamber, When subjected to large amplitude vibration, 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 unsuitable to apply such a mount to a mount such as an engine mount which receives a relatively large amplitude and receives a large relative displacement.

In order to make the above-mentioned bush type mount applicable as an engine mount, a through space communicating with the atmosphere is provided in the elastic body by partitioning it from the sub-fluid chamber with a rubber thin film. It is also conceivable 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 receiving a large internal pressure due to a large displacement, and is not suitable for an engine mount.

[0005] In the case of the above-mentioned bush type mount, liquid and air are sealed in the fluid chamber. When this is used as an engine mount, the elastic body is greatly displaced and the air is contained in the liquid. It is conceivable that the mixed air bubbles enter and remain in the liquid. If 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 attenuation based on the liquid column resonance via the orifice is not exhibited.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object thereof is to provide a bush type liquid-filled mount for an engine mount by providing a through space. The object of the present invention is to avoid the risk of breakage of the rubber thin film that partitions the through space and the fluid chamber, and to prevent bubbles from remaining in the liquid in the fluid chamber.

[0007]

In order to achieve the above object, an invention according to claim 1 comprises an inner cylinder having a cylinder axis arranged laterally, and an outer cylinder surrounding the inner cylinder. An elastic body connecting the outer cylindrical body and the inner cylindrical body to each other, and a periphery of the inner cylindrical body surrounded by an elastic body near the outer cylindrical body at an intermediate position between the inner cylindrical body and the outer cylindrical body. An embedded intermediate cylinder,
The main fluid chamber and the sub-fluid chamber respectively defined in the elastic bodies at both sides in the direction perpendicular to the cylinder axis of the inner cylinder, the liquid and the gas sealed in the two fluid chambers, and the two fluid chambers It is assumed that the orifice is provided with a communicating orifice and a through space penetrating through the elastic body on the side of the sub-fluid chamber from the inner cylinder in parallel with the cylinder axis of the inner cylinder. In this apparatus, the main fluid chamber is disposed below the inner cylinder, and the sub-fluid chamber is disposed above the inner cylinder. The liquid level of the liquid is higher than the sub-fluid chamber side opening of the orifice. Enclose to position.
Then, a concave portion is formed in the portion of the intermediate cylindrical body on the side of the sub-fluid chamber, the concave portion being recessed toward the inner cylindrical body, and the through-cavity and the sub-fluid chamber are defined by a cylindrical wall constituting the concave portion. .

According to a second aspect of the present invention, in the first aspect of the present invention, air bubbles are formed on the lower surface of the elastic body defining the inner upper surface of the main fluid chamber toward the opening of the orifice on the main fluid chamber side. Is formed to form a guide surface leading to

Further, the invention according to claim 3 is the invention according to claim 2.
In the described invention, the orifices are formed so as to open at respective positions near the inner surface of the outer cylinder on both sides in the horizontal direction in the direction orthogonal to the cylinder axis with respect to the main fluid chamber. Then, in a state where one of the inner cylinder and the outer cylinder is connected to the vibration generating source and the other is connected to the vibration receiving portion, the guide surface of the elastic body is set to the lowermost point at the horizontal intermediate portion, and the lowermost point is set. From the point of view, the orifice is formed in a V-shaped cross-sectional shape such that the inner angle on the upper side sandwiched between the surfaces continuous with the main fluid chamber side opening is smaller than 180 degrees.

[0010]

According to the above-mentioned structure, according to the first aspect of the present invention,
Liquid is sealed in the lower main fluid chamber and the upper sub-fluid chamber communicated with the main fluid chamber via an orifice such that the liquid surface is located above the sub-fluid chamber side opening of the orifice, Since gas is sealed in the upper part of the sub-fluid chamber,
The compression and expansion of the gas allows the liquid to flow between the main fluid chamber and the sub-fluid chamber through the orifice, and the vibration is attenuated by the liquid column resonance of the liquid through the orifice. In this vibration damping, the through space is provided, so that it is possible to cope with a large displacement without making the tensile stress acting on the elastic body excessive for a large amplitude vibration input. In addition, since the partition wall that separates the penetrating space and the sub-fluid chamber is formed by the cylindrical wall that is a rigid member that forms the concave portion of the intermediate cylindrical body, a conventional elastic film member such as a rubber thin film is used. As a result, the strength is increased as compared with the case of partitioning, and even if a large internal pressure is received by a large amplitude vibration input, the risk of damage to the partition wall can be avoided. Thereby, in the bush type liquid-filled mount, it is possible to provide the through space in a state in which the risk of damage to the member defining the fluid chamber is avoided, which is suitable for an engine mount.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, a guide surface is formed on the lower surface of the elastic body to guide the bubbles upward toward the orifice. Even if the air collected above the liquid level of the sub-fluid chamber enters the liquid due to the difference and enters the main fluid chamber through the orifice, the air bubbles entering the main fluid chamber are guided to the guide surface and the orifice And is discharged to the upper sub-fluid chamber through this orifice. Then, the bubbles rise in the liquid in the sub-fluid chamber and return to the portion where the 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, according to the third aspect of the present invention, in addition to the effect of the second aspect, the cross-sectional shape of the guide surface on the lower surface of the elastic body has a V-shaped cross-sectional shape having an inner angle smaller than 180 degrees. Therefore, the air bubbles that have entered the main fluid chamber are reliably guided by the guide surface to the openings of any one of the orifices on both sides in the horizontal direction, and the air 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.

FIGS. 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. An outer cylinder 3 disposed on the outer periphery so as to surround the periphery of 1 is an elastic body that connects the outer cylinder 2 and the inner cylinder 1 to each other, and 4 is an elastic body that connects the inner cylinder 1 and the outer cylinder 2 to each other. And an intermediate cylinder embedded in the elastic body 3 at a position close to the outer cylinder 2 so as to surround the inner cylinder 1. Reference numeral 5 denotes a main fluid chamber defined in the lower elastic body 3 of the inner cylindrical body 1;
Is a sub-fluid chamber defined in the elastic body 3 on the upper side of the inner cylinder 1, 7 and 7 are orifices communicating these fluid chambers 5 and 6, and 8 is an upper orifice above the inner cylinder 1. It is a through space that passes through the inside of the elastic body 3 to be changed to the cylindrical axis X. And
The main fluid chamber 5 and the sub-fluid chamber 6 are filled with a liquid 9 as an incompressible fluid and air 10 as a compressible gas. The orifices 7 are sealed so that the liquid surface 9a is located above the auxiliary fluid chamber side opening 7a. Thus, a liquid chamber 6a is formed in the lower half of the sub-fluid chamber 6, and an air chamber 6b is formed in the upper half. 1 to 3 show that the inner cylinder 1 is connected to the vibration receiving portion side of the vehicle body, and the outer cylinder 2 is connected to the engine side which is the vibration generation source, and the own weight of the engine acts on the elastic body 3. The state is shown.

The elastic body 3 is formed by vulcanization integrally with the inner cylindrical body 1 and the intermediate cylindrical body 4, and is formed on the outer cylindrical body via a thin rubber layer 3a which is vulcanized and bonded to the outer peripheral side. 2, the inner cylinder 1 and the outer cylinder 2 are connected to each other by being press-fitted into the inner peripheral surface of the inner cylinder 2. This elastic body 3 supports the inner cylinder 1 in an eccentric state displaced downward relative to the outer cylinder 2 as shown by a solid line in FIG. As a result of the elastic body 3 being bent under the weight of the engine in the mounted state, the inner cylinder 1 is positioned coaxially with the intermediate cylinder 4 and the outer cylinder 2 with respect to the cylinder axis X as shown by a dashed line in FIG. Support. The lower surface 3b of the elastic body 3 has a central portion 3c in a direction perpendicular to the cylinder axis X and in a horizontal direction (hereinafter, referred to as a left-right direction) protruding downward in a state where the own weight of the engine is applied. The lower end of the portion 3c extends obliquely upward toward the main fluid chamber side opening 7b of each of the orifices 7 with the lower end as the lowest point.
A guide surface 11 having a substantially V-shaped cross-sectional shape having an inner angle smaller than 180 degrees between the two openings 7b around the lowermost point is formed.

As shown in detail in FIG. 5, the intermediate cylinder 4 has a window 4a formed by cutting out a lower portion of the outer peripheral surface, and an upper portion is recessed inward to form a recess 4b. Is formed. The main fluid chamber 5 penetrates through the window 4a and is defined by the lower surface 3a of the elastic body 3 and the inner peripheral surface of the outer cylinder 2 opposed to the lower surface 3a. The sub-fluid chamber 6 is defined by the recess 4b and the inner peripheral surface of the outer cylinder 2 that covers the upper part of the recess 4b. in addition,
The recess 4b divides the space between the through space 8 and the sub-fluid chamber 6, and the intermediate cylinder 4 forming the recess 4b.
Constitutes a partition wall 12 for partitioning the two 8 and 6 from each other.

Each of the orifices 7 is provided with the rubber thin layer 3a.
A portion between the main fluid chamber 5 and the sub-fluid chamber 6 is notched in the circumferential direction by a predetermined width in the cylinder axis X direction to form a concave groove, and this concave groove portion and the inner periphery of the outer cylindrical body 2 are formed. It is sandwiched between surfaces.

In FIG. 1 and FIG. 2, reference numeral 3 d denotes a stopper integrally formed with the elastic body 3 so as to protrude toward the through space 8, and the stopper 3 d contacts 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 above-structured fluid-filled engine mount will be described with reference to FIG. 6. First, the inner cylinder 1 and the intermediate cylinder 4 are integrally vulcanized and formed with the elastic body 3 as described above. I do. Next, the integrally molded article 13 and the outer cylindrical body 2 are arranged so that the cylinder axis X is in the vertical direction, and the integrated molded article 13 is placed on the inner peripheral surface of the outer cylindrical body 2 from above.
The rubber thin layer 3a on the outer peripheral surface is press-fitted, and the press-fitting is performed in a state where a gap 15 is opened between the upper end portion 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 thereafter, the integrated molded article 13 is press-fitted to the end. Finally, the upper and lower opening edges 2a and 2b of the outer cylinder 2 are caulked to integrate the two 13 and 2 together. According to this manufacturing method, since it is not necessary to perform the assembling in the liquid tank filled with the liquid 9, there is no need to cause the scattering of the liquid by press-fitting or to wash the liquid attached to the outer surface after the assembling. Also, in the case where the liquid 9 is injected outside the liquid tank by vacuum suction, even if microbubbles are generated in the liquid 9, the microbubbles enter the air 10 in the air chamber portion 6b, so that the attenuation due to the remaining microbubbles. 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 configuration 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 sub-fluid chamber 6 through the orifices 7, 7. The flow causes a liquid column resonance via the orifices 7, 7, and the vibration is attenuated by the liquid column resonance. At the time of the flow of the liquid 9, the liquid 9 is provided on the side of the sub-fluid chamber 6 with the sub-fluid chamber side opening 7 a of each orifice 7.
Since the liquid chamber portion 6a and the air chamber portion 6b are provided so as to be sealed to an upper position, the flow of the liquid 9 through each of the orifices 7 by the compression and expansion of the air 10 in the air chamber portion 6b. It becomes possible.

At the time of the vibration input, the through-hole 8 exists above the elastic body 3, so that even if the input vibration has a large amplitude, the elastic body 3 does not have an excessively large tensile stress. Large displacement, and can exhibit its function as an engine mount. Also, even if the above-described 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 cylinder 4 and is almost a rigid body. Therefore, the strength of the member (partition wall 12) defining the sub-fluid chamber 6 can be remarkably enhanced as compared with the case where the member is defined by an elastic film member such as a rubber thin film. Can be avoided. Therefore, in the bush type engine mount, the through space 8 can be provided without any trouble.

The air 10 in the air chamber 6 b of the sub-fluid chamber 6 is mixed into the liquid 9, and the air bubbles enter the main fluid chamber 5 through the orifices 7 as the liquid 9 flows.
The air bubbles rise in the liquid 9 in the main fluid chamber 5 and rise on the guide surface 11.
And each orifice 7 is guided by this guide surface 11.
And is discharged to the sub-fluid chamber 6 through each orifice 7. Since the bubbles rise in the liquid 9 in the liquid chamber 6a and return to the air chamber 6b naturally, the bubbles can be reliably prevented from remaining in the liquid 9 in the main fluid chamber 5. Thereby, the desired vibration damping performance through the orifices 7 can be maintained.

It should be noted that the present invention is not limited to the above-described embodiment, but includes various other modifications. That is, in the above embodiment, the elastic body 3 is used as the guide surface.
The guide surface 11 having the function of a stopper that projects the lower surface center portion 3c downward and contacts the inner peripheral surface of the outer cylinder body 2 during downward displacement is shown. However, the present invention is not limited to this. The surfaces may have a V-shaped cross section. For example, each of the left and right surfaces sandwiching the lowest point may be a flat surface or a curved surface that is convex downward or upward.

In the above embodiment, the concave portion 4b defining the auxiliary fluid chamber 6 is formed in a groove shape extending in the left-right direction. However, the present invention is not limited to this. For example, the concave portion 4b may be formed in a concave shape.

Further, in the above-described embodiment, the air 10 is sealed as the gas to be sealed in the fluid chamber. However, the present invention is not limited to this, and the main fluid chamber 5 and the sub-fluid 5 are orifice 7, 7 by the expansion and compression of the gas. Any material that allows the flow of the liquid 9 to and from the chamber 6 may be employed. For example, nitrogen gas or the like may be used.

Further, in the above embodiment, the outer cylinder 2 is connected to the engine side and the inner cylinder 1 is connected to the vehicle body. However, the present invention is not limited to this. The inner cylinder 1 may be connected to the engine on the vehicle body.
In this case, the elastic body may be configured to be supported in a state in which the inner cylindrical body is eccentric relative to the outer cylindrical body upward before the connection.

[0028]

As described above, according to the fluid-filled engine mount according to the first aspect of the present invention, the lower main fluid chamber and the upper sub-fluid communicated with the main fluid chamber via the orifice. The liquid is sealed in the chamber so that the liquid level is positioned above the auxiliary fluid chamber side opening of the orifice, and the gas is sealed in the upper part of the auxiliary fluid chamber, so that the gas is compressed and expanded. Thus, the flow of the liquid through the orifice can be generated between the main fluid chamber and the sub-fluid chamber, and the vibration can be attenuated by the liquid column resonance of the liquid through the orifice.

Since a through space is provided for damping the 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 formed by the cylindrical wall that is a rigid member that forms the concave portion of the intermediate cylindrical body, the elastic wall member such as a conventional rubber thin film is used. The strength can be increased as compared with the case of partitioning, and even if a large internal pressure is received by a large amplitude vibration input, the risk of breakage of the partition wall can be avoided.
Thereby, in the bush type liquid-filled mount, the through space can be provided in a state where the member that defines the fluid chamber is prevented from being damaged, and the mount can be used as a suitable engine mount.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, in addition to the above-mentioned effects, the guide surface for guiding bubbles toward the lower opening of the elastic body toward the opening of the orifice on the main fluid chamber side. Is formed, even if bubbles enter the liquid in the lower main fluid chamber due to a 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, bubbles can be reliably prevented from remaining in the liquid in the main fluid chamber, and the original vibration damping effect of the orifice can be reliably exhibited.

According to a third aspect of the present invention, in addition to the effect of the second aspect, a V-shaped cross-section having an inner angle smaller than 180 degrees as a cross-sectional shape of the guide surface of the lower surface of the elastic body. Due to the shape, air bubbles that have entered the main fluid chamber can be reliably guided to the openings of any one of the orifices on both sides in the horizontal direction by the guide surface, and the prevention of air bubbles remaining in the main fluid chamber can be further improved. It can be done reliably.

[Brief description of the 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 of FIG. 1;

FIG. 4 is a diagram 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 longitudinal sectional view showing an assembling procedure.

[Explanation of symbols]

 DESCRIPTION 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 Subfluid chamber 7 Orifice 7a Subfluid chamber side opening 7b Main fluid chamber side opening 8 Penetrating space 9 liquid 9a liquid surface 10 air (gas) 11 guide surface 12 partition wall X cylinder axis

Claims (3)

(57) [Claims] An inner cylinder having a cylinder axis arranged laterally; an outer cylinder surrounding the inner cylinder; an elastic body connecting the outer cylinder and the inner cylinder to each other; An intermediate cylinder embedded in the elastic body near the outer cylinder at an intermediate position between the inner cylinder and the outer cylinder so as to surround the inner cylinder, and a direction orthogonal to a cylinder axis of the inner cylinder. A main fluid chamber and a sub-fluid chamber respectively defined in elastic bodies at both sides of the fluid chamber; a liquid and a gas sealed in the fluid chambers; an orifice communicating the fluid chambers with each other; A fluid-filled engine mount having a through-hole passing through the elastic body on the fluid chamber side in parallel with the cylinder axis of the inner cylinder, wherein the main fluid chamber is located below the inner cylinder, Chambers are respectively disposed above the inner cylinder body, and the liquid level is higher than the sub-fluid chamber side opening of the orifice. A concave portion is formed in the portion of the intermediate cylinder on the side of the sub-fluid chamber, and a concave portion is formed on the side of the inner cylinder, and the through-hole and the sub-fluid chamber are defined by a cylinder wall constituting the concave portion. A fluid-filled engine mount. 2. A fluid filling device according to claim 1, wherein a guide surface for guiding air bubbles upward toward an opening of the orifice in the main fluid chamber is formed on a lower surface of the elastic body defining an inner upper surface of the main fluid chamber. Expression engine mount. 3. The inner cylinder according to claim 2, wherein the orifice is formed in a direction perpendicular to the cylinder axis with respect to the main fluid chamber and at respective positions near the inner surface of the outer cylinder on both sides in the horizontal direction. In a state where one of the body and the outer cylinder is connected to the vibration generating source and the other is connected to the vibration receiving portion, the guide surface of the elastic body is
The middle part in the horizontal direction is the lowest point, and a V-shaped cross-sectional shape is formed such that the upper internal angle sandwiched by the surfaces connected to the main fluid chamber side openings of the orifices from the lowest point is smaller than 180 degrees. A fluid-filled engine mount that has been formed.