JPH0430443Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid-filled bushing used as a shock absorbing support device for an automobile engine or the like.

[Conventional technology]

For example, in a car engine, sudden acceleration,
It is required to take anti-vibration means to suppress changes in attitude due to sudden fluctuations in torque that occur with sudden deceleration, and as a type of anti-vibration device that has this function, conventionally shown in Figs. As shown in FIG. 6, outer sleeves 1 and 2 and inner sleeve 3, which are arranged coaxially with each other, are connected via an elastic body 4, and two partitions are separated by connecting walls 5 and 5 of the elastic body 4. A liquid-filled bushing is known in which the airtight chambers 6, 6 are filled with a working fluid and the two airtight chambers 6, 6 are communicated with each other via an orifice 7. The elastic body 4 has an annular portion at both ends in the axial direction that connects the outer sleeves 1, 2 and the inner sleeve 3 over the entire circumference and defines airtight chambers 6, 6, and has an annular portion in the middle (center in the axial direction). Airtight room 6,
6 into two chambers, and two stopper bosses 8, 8 are provided in a direction perpendicular to the connecting walls 5, 5, and an entrance/exit of the orifice 7 is provided on the outer end surface of the bosses 8, 8. It is formed by forming recesses 9, 9. The orifice 7 consists of holes 11, 11 bored in a metal ring 10 inserted into the elastic body 4 and the inner sleeve 3, and an annular groove 12 formed on the outer circumferential surface of the inner sleeve 3. They are connected to form an orifice flow path.

[Problem that the invention attempts to solve]

In the liquid-filled bushing having the above structure, one of the outer sleeves 1 and 2 and the inner sleeve 3 is fixed to the side wall of the automobile chassis, and the other is fixed to the engine, and the elasticity (spring force) of the elastic body 4 and the orifice 7 are fixed. It uses the flow resistance of the passing hydraulic fluid to absorb vibrations input mainly in the vertical direction in the diagram, but due to its structure, it absorbs large-amplitude low-frequency vibrations (50Hz or less, ±0.5mm or more). Although it is possible to obtain the high damping and high dynamic spring required to effectively absorb this vibration, it is necessary to effectively absorb small amplitude high frequency vibration (50Hz or more, ±0.5mm or less). There is a problem in that it is not possible to obtain an appropriate low damping and low dynamic spring.

[Means for solving problems]

In view of the above points, the present invention aims to provide a liquid-filled bushing that can effectively absorb not only large-amplitude low-frequency vibrations but also small-amplitude high-frequency vibrations.
In order to achieve this purpose, the conventional bushing having the above-mentioned basic structure is further provided with thin-walled actuating parts 15, 15 which form local recesses 14, 14 in the connecting walls 5, 5 and absorb the latter vibrations. did.

[Effect]

When small-amplitude high-frequency vibrations are input to the bush of the present invention, these vibrations are absorbed by the expansion and contraction deformation of the thin-walled operating portion. Therefore, a low damping and low dynamic spring state can be created without the hydraulic fluid flowing into the orifice.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 indicates a first outer sleeve with a part of the peripheral wall cut out, and reference numeral 3 indicates an inner sleeve having an insert 13 (described later) fitted externally in the center in the axial direction, and both sleeves 1, 3 connected by an elastic body 4. This elastic body 4 has connecting walls 5, 5 and stopper bosses 8, 8 between the annular portions at both ends in the axial direction, and an insert 13 is embedded in the stopper bosses 8, 8, which are oriented in the vertical direction in the figure. A second outer sleeve 2 is fitted onto the outer periphery of the first outer sleeve 1, and is surrounded by the sleeve 2, which has a cylindrical shape without a notch, and the elastic body 4, and is divided into two chambers by connecting walls 5, 5. Airtight chambers 6, 6 that are partitioned are constructed. Both airtight chambers 6, 6 filled with hydraulic fluid are formed by recesses 9, 9 formed in the stopper bosses 8, 8, a hole 11 bored in the insert 13, and a groove 12 provided around the inner sleeve 3.
They communicate with each other by means of an orifice 7 which communicates with the two through the orifice 7. The connecting walls 5, 5 of both wings of the elastic body 4 are formed with circular recesses 14, 14 (see FIG. 3) that open toward the airtight chambers 6 on the upper and lower sides of the figure at approximately the center of each, and the deep abutments ( Thin-walled actuating parts 15, 15, which are highly deformable and absorb small-amplitude high-frequency vibrations by expansion and contraction deformation when they are input, are formed on the upper side of the figure.

When large-amplitude, low-frequency vibrations are input to the liquid-filled bushing having the above configuration, the bushing will be affected by the elasticity (spring force) of the elastic body 4 and the flow resistance of the hydraulic fluid passing through the orifice 7, as in the conventional example. The vibration is absorbed by maintaining a high damping and high dynamic spring state. On the other hand, when a high frequency vibration with a small amplitude is input, the thin-walled actuating parts 15, 15 absorb the volume change of the sealed liquid due to the input amplitude, and the working liquid does not flow into the orifice 7. The vibration is absorbed by creating a low damping, low dynamic spring state.
Connecting walls 5,
The shape of the recesses 14, 14 formed in the grooves 5 is not limited to the cylindrical shape shown in the figure, but can be arbitrarily selected depending on the required specifications, such as a rectangular parallelepiped shape. In addition, the thin-walled operating portion 15,
15 deforms as an initial operating part even when large-amplitude low-frequency vibrations are input, so it is necessary to suppress the deformation to a certain amount and to have enough strength (deformation limit) to prevent it from bursting.

[Effect of idea]

As explained above, the fluid-filled bushing of the present invention is provided with a thin-walled operating section that absorbs small-amplitude high-frequency vibrations by forming local recesses in the connecting wall that partitions the internal airtight chamber, and expands and contracts the operating section. It uses deformation to effectively absorb vibrations, and exhibits excellent vibration isolation effects against both high and low frequency vibrations. Furthermore, the bush of the present invention has a simple and compact structure, making it possible to provide a product suitable for supporting internal combustion engines in so-called front-wheel drive passenger cars with limited space.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a liquid-filled bushing according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line in Fig. 1, and Fig. 4 is a thin wall sectional view. FIG. 5 is a partially cutaway front view of a conventional liquid-filled bushing, and FIG. 6 is a cross-sectional view taken along the line -- in FIG. 5. 1, 2... Outer sleeve, 3... Inner sleeve, 4... Elastic body, 5... Connecting wall, 6...
Airtight chamber, 7... Orifice, 8... Stop boss, 9... Recess, 10... Metal ring, 11... Hole, 12... Groove, 13... Insert, 14...
...Concave, 15...Thin-walled operating part.

Claims (1)

[Scope of utility model registration request] The outer sleeves 1, 2 and the inner sleeve 3, which are arranged coaxially with each other, are connected via an elastic body 4, and actuated into two airtight chambers 6, 6 separated by connecting walls 5, 5 of the elastic body 4. In a fluid-filled bushing in which a liquid is sealed and both airtight chambers 6, 6 are communicated with each other via an orifice 7, local recesses 14, 14 are formed in the connecting walls 5, 5.
A fluid-filled bushing characterized in that it is provided with thin-walled actuating portions 15, 15 which absorb small-amplitude high-frequency vibrations.