JP3303371B2 - Cylindrical mission 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 cylindrical transmission mount which is interposed between a transmission case of an automobile and a vehicle body and supports the transmission case with vibration isolation with respect to the vehicle body. The present invention relates to a cylindrical transmission mount that can advantageously reduce the transmission of high-frequency vibrations to the vehicle body.

[0002]

2. Description of the Related Art Conventionally, various types of transmission mounts for automobiles have been proposed. In recent years, in particular, in recent years, the space required for disposing the internal combustion engine and its control device has been limited due to an increase in size thereof. Therefore, there is a great demand for miniaturization and weight reduction of the mission mount. Therefore, as such a mission mount, it is possible to adopt a cylindrical vibration damping device having a structure in which an inner cylindrical metal member and an outer cylindrical metal member arranged at a predetermined distance in a radial direction are connected by a rubber elastic body. Are being considered. In other words, such a cylindrical vibration isolator can exhibit effective vibration isolating functions and stopper functions against vibrations input from a plurality of directions without adding a special stopper member. By adopting it for a mission mount, its size and weight can be advantageously reduced.

By the way, such a cylindrical vibration isolator is
In order to obtain a high damping effect against low frequency vibration such as shake, etc., in addition to a solid type vibration damping device which is only used as an engine mount for FF type automobiles and simply connecting the inner and outer cylinders with rubber elastic body, Japanese Patent Application Laid-Open No. 49-65461 proposes a fluid-filled type vibration damping device having a pair of fluid chambers communicated with each other through an orifice passage.

[0004] However, the anti-vibration characteristics required for the mission mount are 500 to 80 which may cause gear noise and the like.
It is a blocking performance against vibration in a high frequency range of about 0 Hz,
As described above, it is extremely difficult for the cylindrical vibration isolator of the conventional structure to meet such a demand.

[0005] That is, in the solid type vibration damping device, surging resonance of the rubber elastic body is apt to occur when vibration is input in a high frequency range where a vibration blocking effect is required, whereby the dynamic spring constant is greatly increased. There is a problem.In addition, the length and cross-sectional area of the orifice passage are limited in the fluid-filled type vibration damping device due to the mount size and structure, and it is a fact that such an orifice passage is set to a high frequency range. Since this is impossible, the orifice passage is substantially closed in a high frequency region where a vibration blocking effect is required, and the dynamic spring constant is significantly increased.

[0006]

The present invention has been made in view of the above-described circumstances, and a problem to be solved is to have a simple structure and excellent protection against vibration in a high frequency range. An object of the present invention is to provide a cylindrical mission mount capable of exhibiting a vibration effect.

[0007]

In order to solve such a problem, the present invention is characterized in that an inner cylinder and an outer cylinder which are arranged at a predetermined distance from each other in a radial direction are interposed therebetween. in cylindrical mission mount comprising ligate a rubber elastic body that is, in allowed covering the pocket portion opening to the outer peripheral surface of the rubber elastic body at the outer cylindrical member, 100
A fluid chamber filled with an incompressible fluid having a viscosity of mPa · S or less is formed on one side in a direction perpendicular to the axis of the inner cylinder, and the pocket portion is formed from both axial end faces of the rubber elastic body. provided mold cavity portions extending between the inner cylindrical member, respectively in the axial direction side, the with the mold cavity portions pocket
A thin wall portion that provides a bottom wall of the fluid chamber is formed between the inner cylinder and the fluid chamber. There is provided a hollow portion extending through the space between the outer tube fitting and the axial direction.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 3 show a mission mount 10 having a structure according to the present invention.
In these figures, reference numerals 12 and 14 denote an inner cylindrical fitting and an outer cylindrical fitting, which are arranged at a predetermined distance from each other in a radial direction, and are elastically provided by a rubber elastic body 16 interposed therebetween. It is connected to. And, in such a mission mount 10, the inner cylindrical fitting 12 is provided.
Is mounted on one of the transmission case side and the vehicle body side, and the outer cylinder fitting 14 is mounted on the other of the transmission case side and the transmission case, respectively.

[0010] More specifically, the inner cylinder fitting 12 is formed in a thick cylindrical shape. In addition, this inner cylinder fitting 12
A metal sleeve 18 having a thin cylindrical shape is disposed on a substantially same axis at a predetermined distance outside in the radial direction.

A rubber elastic body 16 is interposed between the inner cylindrical fitting 12 and the metal sleeve 18. The inner cylindrical fitting 12 is provided on the inner peripheral surface of the rubber elastic body 16, and a metal elastic body is provided on the outer peripheral surface thereof. The sleeve 18 is formed as an integrally vulcanized molded product which is respectively fixed.

The metal sleeve 18 has a window portion 2 which extends in the central portion in the axial direction with a length substantially less than half a circumference in the circumferential direction.
0 is provided. Furthermore, the rubber elastic body 16 has
A pocket portion 22 is formed at a central portion in the axial direction so as to extend in the circumferential direction with a length substantially less than half a circumference.
An opening is formed on the outer peripheral surface through the window 20 of FIG.

Further, the rubber elastic body 16 is located at an inner peripheral side portion of the pocket portion 22, and the pocket portion 22 and the inner cylinder fitting 1 are respectively located from both axial end surfaces of the rubber elastic body 16.
2, the currant portions 24, 24 extending inward in the axial direction and having a predetermined depth not reaching the center in the axial direction,
Is provided. And these currant parts 24, 24
As a result, both sides in the mount axis direction of the bottom wall of the pocket portion 22 are thinned, and thus the thin rubber walls 26, 26 that are easily elastically deformed are formed.

A center portion of the bottom wall portion of the pocket portion 22 in the axial direction of the mount is formed as a connecting portion 28 connected to the inner cylindrical fitting 12 side, and a tip portion of the connecting portion 28 has a pocket portion. A stopper 30 projecting at a predetermined height from the bottom surface of the base 22 is integrally formed.

At a portion radially opposed to the pocket portion 22 with the inner cylinder fitting 12 interposed therebetween, a hollow portion 32 extending through the rubber elastic body 16 in the axial direction is provided.
It is formed between the inner tube fitting 12 and the metal sleeve 18 over a substantially half circumference in the circumferential direction. Then, the spring characteristics of the rubber elastic body 16 are tuned by the lightening portion 32, and the pocket portion 22 and the lightening portion 32 are set to be soft in the radial direction (the vertical direction in FIG. 2) facing each other.

Further, the metal sleeve 18 has a wide small diameter portion at the axial center portion, and the outer peripheral surface of the small diameter portion has a periphery of the window 20 and a central portion of the hollow portion 32. Are provided with thin seal rubber layers 34, respectively. Note that these seal rubber layers 34 are formed integrally with the rubber elastic body 16.

Then, the outer vulcanized metal fitting 14 is externally inserted into the integrally vulcanized molded product having such a structure and is subjected to octagonal drawing, so that it is externally fitted and fixed to the outer peripheral surface of the metal sleeve 18. Have been. When the outer sleeve 14 is assembled, the opening of the pocket portion 22 is covered in a fluid-tight manner, and the seal rubber layer 34 is pressed between the metal sleeve 18 and the outer sleeve 14 so that the pocket portion is closed. 2
The two openings are sealed, so that a fluid chamber 36 in which a predetermined incompressible fluid is sealed is formed.

The fluid to be filled in the fluid chamber 36 may be 10 fluids in order to obtain a desired vibration damping effect.
It is desirable to use an incompressible fluid having a viscosity of 0 mPa · s or less. For example, water, an alkylene glycol, a polyalkylene glycol, a silicone oil, or a mixture thereof is suitably used. Further, such a fluid can be sealed in the fluid chamber 36 by, for example, assembling the outer tube fitting 14 to the integrally vulcanized molded product in the fluid.

In the transmission mount 10 having such a structure, as described above, the inner cylinder fitting 12 and the outer cylinder fitting 14 are attached to one of the transmission case side and the vehicle body side, respectively. It is interposed in the mounting part, under such mounting state,
Vibration to be damped is input between the inner and outer tube fittings 12 and 14 mainly in the direction in which the fluid chamber 36 and the lightening portion 32 face each other (vertical direction in FIG. 2).

In the transmission mount 10, the rubber elastic body 16 is deformed at the time of vibration input, so that vibration is also input to the fluid chamber 36, which causes internal pressure fluctuation and fluid flow. Yes,
Thus, based on the flow action of the fluid, an excellent anti-vibration effect against vibration in a high frequency range can be exhibited.

By the way, the result of actually measuring the frequency characteristics of the anti-vibration performance (dynamic spring constant) of the mission mount 10 having the above-mentioned structure is the same for a solid type mission mount in which an incompressible fluid is not sealed in the fluid chamber. FIG. 4 shows the results of various tests.

From the test results, it is clear that the mission mount 10 of the present embodiment can exhibit an extremely excellent vibration-proof effect against input vibrations in a high frequency range that causes gear noise and the like. .

The reason why such a vibration-proof effect is exerted has not yet been sufficiently elucidated, but (1) the rubber elastic body 16 is formed by the incompressible fluid sealed in the fluid chamber 36. (2) The thin rubber wall 2 constituting the wall of the fluid chamber 36
6, the fluid chamber 36 at the time of vibration input
(3) A fluid flow is generated in the fluid chamber 36 due to the elastic deformation of the thin rubber wall 26, and a low dynamic spring effect is obtained by the resonance action of the fluid mass. It is thought that it is based on being exhibited.

That is, in the mission mount 10 as described above, since a part of the wall of the single fluid chamber 36 is formed as the thin rubber wall 26 which is relatively easily elastically deformed, the characteristics of the supporting spring and the like are improved. An extremely excellent vibration-damping effect against input vibrations in a high-frequency range can be exerted based on the action of the fluid sealed in the fluid chamber 36 while sufficiently securing the vibration-damping characteristics in the low-frequency range.

The transmission mount 10 does not require an orifice passage or the like. Therefore, the transmission mount 10 has advantages that its structure is simple and compact, that it is easy to manufacture and that it is excellent in cost. It is doing.

Although the embodiment of the present invention has been described in detail, this is a literal example, and the present invention is not construed as being limited to such a specific example.

For example, the thickness, area, and the like of the thin rubber wall portion 26 are appropriately changed according to the required vibration isolation characteristics and the like, and are not particularly limited.

The curl portions 24, 24 formed inward in the axial direction from both axial end surfaces of the rubber elastic body 16,
It may be a curl portion that is connected to each other and penetrates in the axial direction. In this case, a sufficiently wide axially continuous portion of the bottom wall of the fluid chamber 36 can be formed as a thin rubber wall portion.

Further, in the above-described embodiment, the inner cylindrical fitting 12 and the outer cylindrical fitting 14 are arranged substantially coaxially. However, under the mounted state where the weight of the transmission is exerted, the inner and outer cylindrical fittings are substantially coaxial. In advance, to be located in
The inner and outer tube fittings may be arranged eccentrically by a predetermined amount.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included within the scope of the present invention, without departing from the spirit of the present invention.

[0031]

As is apparent from the above description, in the cylindrical transmission mount having the structure according to the present invention, the flow action of the fluid sealed in the fluid chamber having a thin wall portion is partially performed. , The dynamic spring constant in the high frequency range can be reduced, and therefore, a very excellent vibration-proof effect against high-frequency vibration that causes gear noise or the like can be exerted.

In addition, in such a cylindrical transmission mount, it is only necessary to form a single fluid chamber, and there is no need to form a complicated orifice passage or the like. This has the advantage that it can be achieved and is easy to manufacture.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a cylindrical transmission mount as one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a left side view in FIG.

FIG. 4 is a graph showing a result of actually measuring a frequency characteristic of an anti-vibration performance of the cylindrical transmission mount having the structure shown in FIG. 1 together with a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Mission mount 12 Inner tube fitting 14 Outer tube fitting 16 Rubber elastic body 18 Metal sleeve 24 Curtain portion 26 Thin rubber wall portion 32 Lightening portion 36 Fluid chamber

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16F 13/14 B60K 17/06 F16F 13/18

Claims (1)

(57) [Claims] 1. A cylindrical transmission mount comprising an inner cylinder and an outer cylinder which are arranged at a predetermined distance from each other in a radial direction and are connected by a rubber elastic body interposed therebetween. Cover the pocket opening on the outer peripheral surface of the rubber elastic body with the outer cylinder fitting, and have a viscosity of 100 mPa · S or less.
A fluid chamber the non-compressible fluid is sealed with the inner cylinder
And forming the axis-perpendicular direction on one side of the bracket, provided the mold cavity portions extending in the axial inward direction between the axial end surfaces of the rubber elastic body and the pocket portion and the inner cylindrical member, said currants A thin portion that provides a bottom wall of the fluid chamber between the portion and the pocket portion, and the other side in the direction perpendicular to the axis that is opposed to the fluid chamber with the inner cylinder fitting therebetween. A cylindrical transmission mount having a hollow portion extending axially between an inner cylinder and the outer cylinder.