JPH0523866Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) The present invention relates to a fluid-filled vibration-isolating bushing, and more specifically, it exhibits good vibration-isolating function against both low-frequency vibrations and high-frequency vibrations input in the radial direction. The present invention relates to a fluid-filled vibration-proof bushing that can be used as a vibration damper.

(Prior Art) A cylindrical anti-vibration bushing has been known which is installed in a vibration transmission system of an automobile or the like to attenuate or block vibrations mainly input in the radial direction thereof. Examples include automobile suspension bushes, FF (front engine/front drive) car engine mounts, and roll stoppers.

By the way, the anti-vibration bushing is required to have good isolation performance against high-frequency, small-amplitude input vibrations, but it is also required to have good damping performance against low-frequency, large-amplitude input vibrations. However, in conventional anti-vibration bushings, the anti-vibration function against these input vibrations was obtained only by the elastic deformation of the rubber elastic body, so it is difficult to satisfy both of these requirements. There was a problem in that it was difficult to achieve a sufficient damping effect, especially for input vibrations of low frequency and large amplitude.

Therefore, in recent years, in Japanese Patent Publication No. 48-36151 and Japanese Patent Publication No. 52-16554, a pair of fluid chambers are formed in a rubber elastic body so as to face each other in the vibration input direction, and these fluid chambers are communicated with each other through an orifice. A fluid-filled anti-vibration bushing has been proposed in which a predetermined incompressible fluid contained in each fluid chamber can mutually flow through the orifice thereof when vibration is input. According to such a fluid-filled vibration-isolating bushing, it is possible to obtain a good damping effect against low-frequency, large-amplitude input vibrations based on the viscous resistance and inertial effect when incompressible fluid flows through the orifice. Therefore, in combination with the elastic deformation effect of the rubber elastic body, a relatively good vibration damping function can be obtained.

(Problem) However, in such a fluid-filled anti-vibration bushing, the orifice (length and cross-sectional area) is set so that the damping force peaks in the low frequency range. There is a problem in that the dynamic spring constant in the high frequency range becomes high and the isolation effect against high frequency - small amplitude vibrations decreases.Conversely, if the orifice is set so that the dynamic spring constant is low in the high frequency range, the low frequency The problem is that a sufficient damping effect cannot be obtained for large-amplitude input vibrations, and the reality is that a sufficient vibration isolation function has not yet been obtained.

On the other hand, in the above-mentioned fluid filled type vibration isolating bushings, the fluid filled type vibration isolating supports disclosed in JP-A-53-5376, JP-A-57-9340, etc. A fluid pressure absorption mechanism with a movable plate is provided, as shown in the figure, and a good damping effect is achieved against low frequency and large amplitude input vibrations based on the viscous resistance and inertial effect of the incompressible fluid flowing through the orifice. At the same time, the idea is to reduce the dynamic spring constant through the fluid pressure absorption action of the fluid pressure absorption mechanism, thereby achieving a good isolation effect against high frequency and small amplitude input vibrations. It will be done.

However, if such a fluid pressure absorption mechanism is adopted, the bushing structure becomes extremely complicated, which is economically disadvantageous, and there are also space constraints, so it is difficult to adopt such a fluid pressure absorption mechanism. It is.

(Solution) The present invention was developed against this background, and its feature is that it blocks or damps vibrations input in the radial direction, as described above. A fluid-filled anti-vibration bushing includes (a) an inner cylindrical member, and (b) a pair of parts arranged concentrically or eccentrically on the outside of the inner cylindrical member and facing each other across the axis. an outer cylindrical member having a window; (c) a seal sleeve fitted onto the outer circumferential surface of the outer cylindrical member in a state that fluid-tightly closes the pair of windows of the outer cylindrical member; and (d) the inner a rubber elastic body that is located between and connects the cylindrical member and the outer cylindrical member, and is provided with a cavity that is located at a portion corresponding to the window of the outer cylindrical member and penetrates in the axial direction; , (e) made of a rubber elastic material, seated on the rubber elastic body separately from the rubber elastic body within a corresponding through space of the rubber elastic body, and having the window as an opening. (f) a pair of pocket-shaped rubber wall members each having a recess formed in a state in which at least a portion of the side wall portion can bulge outward; (g) a stopper portion that integrally projects from the bottom of the recess toward the sealing sleeve at a predetermined height; a pair of fluid chambers each formed by being fluid-tightly closed; (h) a predetermined incompressible fluid sealed in each of the pair of fluid chambers; and (i) the pair of fluid chambers. and an orifice that allows the fluid chambers to communicate with each other and allows the incompressible fluid sealed in the fluid chambers to mutually flow between the fluid chambers.

(Function/Effect) In the fluid-filled anti-vibration bushing according to the present invention, the low frequency
When large-amplitude vibrations are input, the incompressible fluid sealed in these fluid chambers flows through orifices connecting these fluid chambers according to the tuning of the orifices, similar to the conventional fluid-filled vibration isolating bushing. The vibrational input is advantageously damped due to the viscous resistance and inertial effects of the incompressible fluid as it flows through the orifice.

On the other hand, if the vibration input in the opposite direction of the fluid chamber is of high frequency and small amplitude, the incompressible fluid is prevented from passing through the orifice, so the incompressible fluid flows through the orifice. In some cases, it is not possible to expect the dynamic spring constant to decrease. However, in this case, since the side walls of the recesses defining each fluid chamber are configured to bulge outward, the side walls of the recesses are subject to an increase in fluid pressure within each fluid chamber due to vibration input. This will be effectively alleviated by the swelling effect of . In other words, in this case, the bulging action of the side wall of the recess suppresses the increase in the dynamic spring constant of the vibration-proof bushing as a whole, and the low dynamic spring characteristics of the rubber elastic body are improved accordingly. This makes it possible to effectively utilize the vibration-isolating bushing, and it is possible to exhibit a vibration-isolating effect that is superior to that of conventional fluid-filled vibration-isolating bushings.

As described above, according to the fluid-filled vibration-isolating bushing according to the present invention, among the vibrations input in the radial direction of the bushing where the fluid chamber faces, low-frequency and large-amplitude vibrations are dealt with by the non-compressible vibration that flows through the orifice. A good damping effect can be obtained based on the viscous resistance and inertial effect of the fluid, and high frequency and small amplitude vibrations can be effectively blocked by the bulging action of the walls of the fluid chamber. Therefore, it is possible to obtain a vibration damping function superior to that of a conventional fluid-filled vibration damping bushing against vibrations input in the opposite direction of the fluid chamber.

Moreover, according to the present invention, such a vibration-proofing function can be obtained simply by making the wall of the fluid chamber expandable to the outside, so that when a fluid pressure absorption mechanism with a movable plate is adopted It has the advantage that it has a simpler structure than the conventional one, and it also has the advantage that it is economically advantageous.

Further, in the present invention, the rubber wall member is formed separately from the rubber elastic body, and the rubber wall member is seated on the rubber elastic body in a removable state. Regardless of the magnitude of the displacement of the input vibration, no direct tensile stress from the inner and outer cylinder members acts on the rubber wall member on the side where the inner and outer cylinder members are separated, and therefore the rubber wall member is affected by the input vibration. It has the advantage that it is less susceptible to repeated bending fatigue, and its durability, and thus the durability of the fluid chamber, can be improved.

In addition, in the present invention, the stopper part is integrally formed at the bottom of the rubber wall member, so that excessive displacement between the inner cylinder member and the outer cylinder member, and ultimately between the power unit and the vehicle body is effectively prevented. There are characteristics that can be prevented, and furthermore, this suppresses excessive deformation of the rubber elastic body and the rubber wall members that define the fluid chamber, so the durability of these members and, by extension, of the anti-vibration bushing are It also exhibits features that improve its lifespan.

(Example) In order to clarify the present invention more specifically, an example in which the present invention is applied to a roll stopper of a FF (front engine, front drive) vehicle will be described in detail based on the drawings.

First, in FIGS. 1 and 2, 10 and 12 are a cylindrical inner metal fitting as an inner cylinder member and a cylindrical outer metal fitting as an outer cylinder member, which are arranged concentrically with each other. and are elastically connected by a rubber block 14 as a rubber elastic body interposed between them. Further, a metal sleeve 16 serving as a sealing sleeve is fitted onto the outer peripheral surface of the outer cylinder fitting 12. The roll stopper of this embodiment is fitted into and attached to a cylindrical member on the power unit side including the engine or the vehicle body side on the outer peripheral surface of the metal sleeve 16, and is attached to the inner cylindrical metal fitting 1.
The power unit is attached to the mounting shaft on the vehicle body side or the power unit side in the inner hole 18 of 0, thereby supporting the power unit with respect to the vehicle body. In addition, rubber block 14
is integrally fixed to the inner cylindrical metal fitting 10 and the outer cylindrical metal fitting 12 by vulcanization adhesive.

Here, as shown in FIG. 3 and FIG.
A pair of window portions 2 are located at opposing parts with the
0, 20 are formed, and a pair of orifice grooves 22, 22 are formed on the outer circumferential surface of the orifice grooves 22, 22, located at opposing positions with the inner cylinder fitting 10 in between, and connecting the windows 20, 20. ing. Also,
As shown in those figures, the rubber block 14 has a pair of cavities 24, 24 located at portions corresponding to the windows 20, 20 of the outer cylinder fitting 12 and penetrating in the axial direction. It is formed.

Here, the window portions 2 are located in the spaces 24, 24 penetrating in the axial direction, respectively.
0, and the bottom portion is seated on the rubber block 14 to open each corresponding cavity 2.
4 in the circumferential direction of the roll stopper, thin-walled rubber walls 26, 2 are formed separately from the rubber block 14 and at the same time as the rubber block 14.
A recess 28, 28 defined by 6 is formed. In addition, a block-shaped stopper portion 3 is provided in the recesses 28, 28 and extends at a predetermined height from the bottom of the recesses 28, 28.
0 and 30 are formed integrally with the rubber walls 26 and 26, respectively.

In this embodiment, as shown in FIGS. 1 and 2, such a rubber block 1 is used.
The metal sleeve 1 for the integrally vulcanized molded product of 4.
6 is fitted, the windows 20, 20 of the outer cylindrical fitting 12 and the openings of the recesses 28, 28 are respectively fluid-tightly closed, and the internal spaces of the recesses 28, 28 are closed, respectively. A pair of fluid chambers 32, 32 serving as fluid storage spaces are formed.
Moreover, by fluid-tightly closing the openings of the orifice grooves 22, 22, these fluid chambers 3
A pair of orifices 34, 34 are formed that allow the holes 2, 32 to communicate with each other. Furthermore, in this embodiment, the fitting operation of the metal sleeve 16 is performed in a predetermined incompressible fluid, so that water, alkylene glycol, polyalkylene glycol, silicone oil,
A predetermined incompressible fluid, such as a base molecular weight polymer, is enclosed.

Note that the outer cylindrical fitting 12 includes a metal sleeve 1.
6, the rubber block 14 is subjected to an eight-way drawing process before being fitted, thereby applying a predetermined precompression to the rubber block 14. In addition, the metal sleeve 16
As shown in FIG. 5, before the roll stopper is assembled, it has a cylindrical shape, and after this cylindrical shape is inserted into the outer cylindrical metal fitting 12 and subjected to eight-way drawing processing. , is fixed to the outer cylindrical metal fitting 12 by roll caulking both ends in the axial direction. Furthermore, as shown in FIG. 5, on the inner peripheral surface of the metal sleeve 16,
A sealing rubber layer 38 with sealing lips 36 at both ends in the axial direction is integrally vulcanized, and as shown in FIGS. 1 and 2,
By compressing the seal rubber layer 38 with the outer cylinder fitting 12, the fluid tightness of each fluid chamber 32, 32 is ensured. Further, the length and cross-sectional area of the orifices 34, 34 (orifice grooves 22, 22) are tuned with respect to vibrations in the low frequency range.

According to such a roll stopper, low frequency and large amplitude vibrations are input between the inner cylinder fitting 10 and the outer cylinder fitting 12 (metal sleeve 16) in the opposite direction of the fluid chambers 32, 32, and the vibration input is Depending on the fluid chamber 3
When a fluid pressure difference occurs between 2 and 32, the incompressible fluid is caused to flow through the orifices 34, 34 from the side with higher fluid pressure to the side with lower fluid pressure, and the incompressible fluid that can be made to flow through the orifices 34, 34 Due to the viscous resistance and inertial effects of the fluid, the vibration input will be well damped.

On the other hand, if the vibrations input into the opposing directions of the fluid chambers 32, 32 are of high frequency and small amplitude,
Since the flow of the incompressible fluid through the orifices 34, 34 is inhibited, the dynamic spring constant of the roll stopper cannot be expected to be lowered by the flow of the incompressible fluid through the orifices 34, 34. However, in this case, as described above, the recesses 2 defining each fluid chamber 32, 32 are
Since the walls 8 and 28 are composed of thin rubber walls 26 and 26, the rubber walls 26 and 26
The side wall portion of the roll bulges in the axial and circumferential directions of the roll stopper in response to vibration input, and this bulging action absorbs the fluid pressure generated in each fluid chamber, effectively mitigating the rise in fluid pressure. be done. In other words, in this case, the dynamic spring constant of the roll stopper as a whole can be favorably increased by the bulging action of the side wall portions of the rubber walls 26, 26 (recesses 28, 28) that define the fluid chambers 32, 32. Therefore, it becomes possible to utilize the low dynamic spring characteristics of the rubber block 14 more effectively than before, and it is possible to obtain a vibration isolation effect superior to that of the conventional one.

As described above, according to the roll stopper according to this embodiment, the orifice 3
A good damping effect can be obtained based on the viscous resistance and inertial effect of the incompressible fluid flowing through the fluid chambers 4 and 34, and the rubber of the fluid chambers 32 and wall 26, 26
According to the expansion action of the fluid chambers 32, an effective isolation function can be exhibited, and a vibration isolation function superior to the conventional one can be obtained against vibrations input in opposite directions of the fluid chambers 32, 32. This is possible.

Moreover, according to this embodiment, such a function can be obtained with an extremely simple structure, and the manufacturing cost can be kept low.

Further, according to this embodiment, the rubber walls 26, 26 are separate from the rubber block 14, and are seated on the rubber block 14 in a detachable state, so that the displacement of the input vibration is reduced. Regardless of the size, direct tensile stress from the inner and outer cylinder fittings 10 and 12 does not act on the rubber wall on the side from which the inner and outer cylinder fittings 10 and 12 are separated, and therefore the rubber walls 26 and 26 receive input vibration. It is difficult to undergo repeated bending fatigue due to
Therefore, the durability of No. 2 can be improved. In addition, in this embodiment, the fluid chamber 3
The stopper portions 30 and 32 protrude into the interior of the stopper portions 2 and 32, respectively.
30, there is an advantage that excessive displacement between the inner cylinder fitting 10 and the outer cylinder fitting 12, as well as the power unit and the vehicle body, is effectively prevented. 1
4 and the rubber walls 26, 2 that define the fluid chambers 32, 32.
Since excessive deformation of the rollers 6 is well suppressed, there is an advantage that their durability and, ultimately, the life of the roll stoppers are improved.

Although one embodiment of the present invention has been described above, this is merely an example, and it goes without saying that the present invention should not be interpreted as being limited to this specific example.

For example, in the embodiment, each fluid chamber 32, 32
Rubber walls 26, 26 defining (recesses 28, 28)
The whole of the rubber walls 26, 26 was made thin so that the entire side wall portions of the rubber walls 26, 26 could bulge outward when high frequency/small amplitude vibrations were input.
A part of those side walls is formed into a thin wall, and the rubber walls 26, 2 are formed in a part of the side wall which is formed into a thin wall.
6 can be made to bulge outward, and the thickness of the bulged side wall portion can also be determined as appropriate depending on the vibration frequency to be blocked.

Further, in the embodiment described above, the fluid chambers 32, 32 are communicated with each other by a pair of orifices 34, 34, but the number of orifices formed is not necessarily limited to this, and the length and The cross-sectional area can also be changed as appropriate depending on the purpose.

Furthermore, in the embodiment described above, an example was described in which the present invention was applied to a roll stopper of a front-wheel drive vehicle.
It can also be applied to other anti-vibration bushings such as car engine mounts. Note that when the present invention is applied to an engine mount or the like, the inner cylinder member (inner cylinder metal fitting 10) and the outer cylinder member (outer cylinder metal fitting 12) are usually placed in opposite directions of the fluid chambers (32, 32). They are arranged with a certain amount of eccentricity, so that when a load such as an engine is applied, they will be positioned concentrically.

Although not listed in detail, the present invention may be subject to various changes, modifications, and modifications without departing from its spirit.
It goes without saying that the present invention can be implemented in a modified form.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an example of a roll stopper according to the present invention, and FIG. 2 is a cross-sectional view taken along the line shown in FIG. 3 is a sectional view corresponding to FIG. 1 showing an integrally vulcanized product of the rubber block in the roll stopper of FIG. 1, and FIG.
It is a - sectional view in the figure. FIG. 5 is a sectional view corresponding to FIG. 1 showing the shape of the metal sleeve in the roll stopper of FIG. 1 before the roll stopper is assembled. 10... Inner tube fitting (inner tube member), 12... Outer tube fitting (outer tube member), 14... Rubber block (rubber elastic body), 16... Metal sleeve (seal sleeve), 20... Window section, 22... Orifice groove, 2
4...Vacancy, 26...Rubber wall, 28...Concavity, 3
0...stopper part, 32...fluid chamber, 34...orifice.

Claims (1)

[Claims for Utility Model Registration] An inner cylindrical member and an outer cylindrical member having a pair of windows disposed concentrically or eccentrically on the outside of the inner cylindrical member and located at opposing positions across the axis. a seal sleeve fitted onto the outer peripheral surface of the outer cylinder member in a state that fluid-tightly closes the pair of windows of the outer cylinder member; and a seal sleeve located between the inner cylinder member and the outer cylinder member. a rubber elastic body having a cavity located at a portion corresponding to the window of the outer cylinder member and extending through each in the axial direction; and a rubber elastic body made of a rubber elastic material, and connecting them. At least a part of the side wall portion is formed in a state in which the rubber elastic body is seated separately from the rubber elastic body in a corresponding through space of the body, and the window portion is an opening. a pair of pocket-shaped rubber wall members each having a recess that is capable of expanding and deforming; and within each recess of the pair of rubber wall members, the member extends integrally from its bottom toward the sealing sleeve by a predetermined height. a pair of fluid chambers formed by fluid-tightly closing the recesses of the pair of rubber wall members at the open windows thereof with the seal sleeve; Predetermined incompressible fluids are respectively sealed in a pair of fluid chambers, and the pair of fluid chambers are made to communicate with each other, so that the incompressible fluids sealed in the fluid chambers mutually flow between the fluid chambers. A fluid-filled anti-vibration bushing comprising: an orifice that allows the vibration to occur;