JPH0341238A - Fluid filled type cylinder shape mount device - Google Patents

Abstract

PURPOSE:To improve vibration isolation performance by making at least a part of a rubber elastic body which constitutes a mount axis direction wall part a thin part so as to allow a predetermined amount of swelling deformation and by storing movable members capable of moving in pressure chambers. CONSTITUTION:In a fluid filled type cylinder shape mount device, an inner cylinder fitting 10 and an outer cylinder fitting 12 are connected with each other by rubber elastic body 14, incompressible fluid is filed in a plurality of pressure chambers 32 and 34, and flowing is allowed to each other through an orifice passage 36. As for these pressure chambers 32 and 34, a part of the rubber elastic body 14 which constitutes a mount axis direction wall part 25 is made a thin part so that a predetermined amount of swelling deformation is capable in the axial direction of a bush 16. And movable blocks 38 and 40 are stored inside capable of moving so as to form a predetermined interval of a vibration action part, which may generate flowing of fluid at the time of vibration input, between the inner surfaces of the pressure chambers 32 and 34. In this way, excellent vibration isolation performance is obtained against input vibration in a wide frequency range.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a fluid-filled cylindrical mount device that obtains a predetermined vibration damping effect based on the flow of a fluid sealed inside, and particularly relates to a fluid-filled cylindrical mount device that achieves a predetermined vibration damping effect based on the flow of a fluid sealed inside. While effectively ensuring a vibration-proofing effect against human-powered vibrations, an increase in the dynamic spring constant when inputting vibrations in a high frequency range can be effectively reduced or prevented.
The present invention relates to a fluid-filled cylindrical mount device with a simple structure.

(Background Art) Conventionally, vibration transmission systems have been interposed between members that constitute vibration transmission systems.
As a type of mount device that connects these two components in a vibration-proof manner, a cylindrical metal fitting and an outer cylindrical metal fitting arranged at a predetermined distance from each other in the radial direction are integrally connected by a rubber elastic body interposed between them. A so-called cylindrical mount device is known, which has a structure in which the mount device is connected to the cylindrical mount device. With such a cylindrical mount device, it is possible to advantageously realize a compact mount size, and it is also possible to easily perform a stomper function that defines the relative displacement amount of the inner and outer cylindrical fittings when an excessive vibration load is applied manually. For example, it can be used as an engine mount for a front-wheel drive vehicle with a horizontal engine.
It has been suitably used.

In addition, in recent years, as shown in JP-A-56-16424 and JP-A-61-270533,
A predetermined incompressible fluid is sealed between the cylindrical fitting and the outer cylindrical fitting in such a cylindrical mount device, and internal pressure fluctuations occur when vibration is input in a predetermined radial direction between the inner and outer cylindrical fittings. A so-called fluid-filled cylindrical mount device has been proposed, which has a structure in which a plurality of pressure receiving chambers are formed, and an orifice passage is provided to communicate the pressure receiving chambers with each other. Based on the resonance effect of the fluid that is caused to flow, it is possible to obtain an excellent vibration damping effect that cannot be obtained with rubber elastic bodies alone, so their use is increasing.

However, in such a fluid-filled cylindrical mount device, the effect of improving vibration damping performance due to the resonance effect of the fluid can only be effectively exhibited in a limited frequency range set in the orifice passage. For this reason, for example, if the orifice passage is tuned so that a high damping effect can be exhibited when vibration is input in a low frequency range, the orifice passage is tuned when vibration is input in a frequency range higher than the tuning frequency. This causes the mount to have a highly dynamic spring, resulting in a significant drop in vibration damping performance.

Therefore, in the past, for example,
As shown in the above-mentioned publications, an umbrella member that extends in a direction perpendicular to the vibration input direction is accommodated in the pressure receiving chamber by being supported by an inner cylindrical metal fitting, and the outer peripheral edge of the umbrella member is By forming a constricted part between the inner surface of the pressure-receiving chamber and the inner surface of the pressure-receiving chamber, where fluid flow occurs when vibration is input,
A device has been proposed in which the orifice passage is substantially closed based on the resonance effect of the fluid flowing through the narrowed portion, and a low dynamic spring effect is obtained when vibration is input in a high frequency range.

However, the cylindrical mount device with such a structure not only has a complicated structure and is difficult to manufacture;
When a large load is applied in the twisting, twisting, or axial directions, the umbrella member comes into contact with and interferes with the rubber elastic body that makes up the wall of the pressure receiving chamber, resulting in significantly poor vibration isolation performance. This was not necessarily satisfactory, as it was difficult to obtain sufficient durability.

(Solution Section B) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problems to be solved are:
While ensuring the vibration damping effect due to the resonance effect of the fluid flowing in the orifice passage, the rise in the dynamic spring constant when vibration is input in a higher frequency range is effectively reduced or reduced based on the resonance effect of the fluid. An object of the present invention is to provide a fluid-filled cylindrical mount device with a simple structure that can prevent the above problems.

(Solution Means) In order to solve this problem, the present invention includes an inner cylindrical metal fitting and an outer cylindrical metal fitting that are arranged at a predetermined distance from each other in the radial direction. The inner and outer cylindrical metal fittings are elastically connected by a rubber elastic body, and a predetermined incompressible fluid is sealed inside each of the inner and outer cylindrical metal fittings to provide a predetermined flow between the inner and outer cylindrical metal fittings. A plurality of pressure receiving chambers are formed in which internal pressure fluctuations are generated when radial vibration is applied manually, and an orifice passage is provided to connect the pressure receiving chambers with each other and allow fluid to flow between the pressure receiving chambers. The fluid-filled cylindrical mount device is characterized in that in at least one of the pressure receiving chambers, at least a portion of the rubber elastic body constituting the mount axial wall portion is made into a thin wall portion, so that a predetermined amount of bulging deformation occurs. On the other hand, by housing and arranging a movable member having an outer peripheral surface shape one size smaller than the inner peripheral surface shape of the pressure receiving chamber in a freely movable manner, The present invention is characterized in that a vibration-acting portion with a predetermined gap is formed between the movable member and the inner surface of the pressure-receiving chamber, in which a fluid flow is generated when vibration is input between the inner and outer cylindrical fittings.

(Examples) Hereinafter, in order to clarify the present invention more specifically, examples of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 3 show an embodiment in which the present invention is applied to a suspension bushing for an automobile. In these figures, 10 and 1
Reference numerals 2 denote an inner cylindrical metal fitting and an outer cylindrical metal fitting, which are arranged concentrically with each other at a predetermined distance in the radial direction, and a rubber elastic body 14 is interposed between them. They are integrally and elastically connected.

In such a suspension bushing 16, the inner cylindrical metal fitting 10 is attached to one member to be vibration-proofly connected via the pivot shaft inserted into the inner hole 18, while the outer cylindrical metal fitting 12 is press-fitted and fixed into a mounting hole provided in the other member to be connected for vibration isolation, thereby being interposed between connecting parts such as arms and rods that constitute the suspension mechanism of the automobile. In addition, under such mounting conditions, the suspension bushing 16
, the main vibration is input in the vertical direction in FIG.

More specifically, the inner cylindrical metal fitting 10 is formed in a thick cylindrical shape. Further, a metal sleeve 20 having a thin cylindrical shape is disposed radially outward of the cylindrical fitting 10 at a predetermined distance. The rubber elastic body 1 is placed between the inner cylinder fitting 10 and the metal sleeve 20.
4 is interposed, and the rubber elastic body 14 is connected to the cylindrical metal fitting 1.
0 and the inner peripheral surface of the metal sleeve 20,
They are each formed as an integral vulcanized molded product that is vulcanized and bonded together.

Further, in the rubber elastic body 14, pocket portions 22 that penetrate the metal sleeve 20 and open on the outer circumferential surface are formed at positions facing each other in one radial direction with the inner cylinder fitting 10 interposed therebetween. ing.

In short, the metal sleeve 20 has a pocket portion 22.2.
A window portion 24 is provided at each of the two forming portions, and the pocket portions 22.22 are opened to the outside through the window portion 24.24.

In addition, regarding the rubber elastic body 14 constituting the peripheral wall portion of these pocket portions 22.22, the wall portion 25.25 in the bushing axis direction of each pocket portion 22 is thinned, particularly at the outer peripheral edge portion thereof, A predetermined amount of bulging deformation in the axial direction of the bush is allowed.

Furthermore, the rubber elastic body 14 has a pocket portion 22.
．． The pocket portions 22 extend continuously in the circumferential direction on one side between the circumferential edges of the openings in the openings 22 .
．． A concave groove 26 is formed to connect the 22 with each other. Note that the metal sleeve 20 is also provided with a window 28 extending in the circumferential direction at the region where the groove 26 is formed, and the groove 26 is opened to the outside through this window 28.

Furthermore, in the integrally vulcanized molded product as described above, diameter reduction processing is performed on the metal sleeve 20 as necessary.
After preliminary compression is applied to the rubber elastic body 14, the outer cylindrical fitting 12 is inserted onto the outer circumferential surface of the rubber elastic body 14, and the outer circumferential surface of the metal sleeve 20 is reduced in diameter by a helical drawing or the like. It is fitted and fixed to. A thin sealing rubber layer 30 is integrally provided on the inner circumferential surface of the outer cylindrical fitting 12 over substantially the entire surface thereof.

By fitting the outer cylindrical fitting 12, the pocket portions 22, 22 and the grooves 2 provided in the rubber elastic body 14 are formed.
6 are closed fluid-tightly, and these pocket portions 22, 22 and grooves 26 are closed fluid-tightly.
A predetermined incompressible fluid is sealed inside each of them. In addition, such incompressible fluids include, so that fluid flow as described below can be effectively generated.
It is desirable to have a kinematic viscosity of 200 cSt or less, particularly preferably 50 cSt or less, and for example, water, alkylene glycol, polyalkylene glycol, silicone oil, etc. are preferably employed.

In addition, such fluid can be advantageously sealed by, for example, performing an operation of inserting the outer cylindrical fitting 12 into the fluid with respect to the integral gag-shaped article.

In addition, as a result, when the vibration is applied manually, the rubber elastic body 14 is formed between the inner cylindrical metal fitting 10 and the outer cylindrical metal fitting 12 at a portion located opposite to each other in one radial direction, which is the vibration input direction, with the cylindrical metal fitting 10 in between. A first pressure receiving chamber 32 and a second pressure receiving chamber 34, in which internal pressure fluctuations with opposite signs are generated based on elastic deformation, are formed in the pocket portion 22, 22, respectively. and No. 20 pressure receiving chambers 32 and 34 are made to communicate with each other, and both pressure receiving chambers 32 and 20 are made to communicate with each other.
．． an orifice passage 36 that allows fluid flow between 34;
is formed within the groove 26.

That is, fluid flows into the orifice passage 36 based on the internal pressure difference created between the first pressure receiving chamber 32 and the second pressure receiving chamber 34 when vibration is input between the inner and outer cylindrical fittings 10 and 12. This will result in a flow of
Therefore, as is well known, by appropriately tuning the orifice passage 36, a predetermined vibration damping effect can be achieved based on the resonance effect of the fluid flowing through the orifice passage. In particular, in this embodiment, the resonance frequency of the fluid flowing through the orifice passage 36 is set to a low frequency range,
As a result, it is tuned to exhibit a high damping effect against low-frequency, large-amplitude human vibrations that correspond to shimmies, shakes, and the like.

In addition, there, the 1st and 20th pressure receiving chambers 32
．． 34, since the axial wall portion 25 is thinned, there is a concern that the liquid pressure within the pressure receiving chamber 32, 34 may be absorbed due to elastic deformation of the axial wall portion 25.
As described above, when a low frequency, large amplitude vibration is input, in which the orifice effect is exerted, the fluid pressure fluctuations generated in the pressure receiving chambers 32 and 34 are large, and the fluid flowing through the orifice passage 36 due to the fluid pressure fluctuations is large. Since the flow is quickly generated, inhibition of the orifice function due to the absorption of hydraulic pressure by the axial wall portion 25 hardly poses a problem.

Furthermore, the first pressure receiving chamber 32 formed as described above
The second pressure receiving chamber 34 has a first movable block 38 and a second movable block 40 inside thereof.
Each is arranged to accommodate them. These first and second movable blocks 38.40 each have an outer peripheral surface shape that approximately corresponds to the inner peripheral surface shape of the first and second pressure receiving chambers 32.34, and that is one size smaller than that. It is housed and arranged in each pressure receiving chamber 32, 34 so as to be freely movable within a predetermined distance.

The material of these first and second movable blocks 38 and 40 is not particularly limited as long as it is hard and does not deform easily, and may be made of aluminum alloy, synthetic resin, etc., and may have a specific gravity relative to the enclosed fluid. However, corrosion resistance to the enclosed fluid should be taken into consideration. However, in this embodiment, the first movable block 38 accommodated in the first pressure receiving chamber 32, which is positioned vertically upward during installation, is formed to have a specific gravity slightly larger than that of the sealed fluid. On the other hand, the second movable block 40 accommodated in the No. 20 pressure receiving chamber 34, which will be positioned vertically below when installed,
It is formed to have a specific gravity slightly smaller than that of the sealed fluid.

And these first and second movable blocks 38.40
As shown in FIG. 4, based on the fluid flow induced in the first and second pressure receiving chambers 32, 34 when vibration is input between the inner and outer cylindrical fittings 10, 12,
It is floated in the first and second pressure receiving chambers 32, 34, thereby forming a vibrating section with a predetermined gap around each of which a fluid flow is generated.

Moreover, there, the first and second pressure receiving chambers 32
．． 34, the input vibration is applied to the orifice passage 3.
At a higher frequency than the resonance point of the fluid flowing through 6,
Even in a state where the orifice passage 36 is substantially closed, fluid flow is effectively generated within each bushing based on the elastic deformation of the axial wall portions 25 and 25. Therefore, by utilizing the resonance effect of the fluid flowing in the vibration acting portions formed in the first and second pressure receiving chambers 32 and 34, the orifice is An increase in the bush dynamic spring constant due to the blockage of the passage 36 can be effectively reduced or prevented.

The resonant frequency of the fluid flowing through the vibration acting section can be tuned by adjusting the mass of the movable block 38, 40, the viscosity of the enclosed fluid, or the thickness and size of the vibration acting section. can be,
In particular, it is easy to set it to a high frequency range. In particular, in this embodiment, based on the resonance effect of the fluid flowing in the vibration acting section, a low dynamic spring effect can be exerted against input vibrations of high frequency and small amplitude corresponding to road noise etc. It is tuned as follows.

Therefore, in the suspension bushing 16 having the above-described structure, when a vibration is input in a low frequency range, an excellent damping effect can be exhibited due to the resonance effect of the fluid flowing through the orifice passage 36. When inputting vibrations in the high frequency range, the - and 20th pressure receiving chambers 32.3
Since a low dynamic spring effect can be effectively exerted by the resonance action of the fluid in the vibration acting part formed in the bushing 4, the high dynamic spring effect of the bushing due to the blockage of the orifice passage 60 can be advantageously avoided. Therefore, extremely good vibration insulation properties can be exhibited.

In addition, in such a suspension bushing 16, the first and second movable blocks 38 are accommodated in the first and second pressure receiving chambers 32 and 34 and form a vibration acting section.
．． 40 can be freely moved within the pressure receiving chambers 32 and 34, so that a load such as a twisting direction, a prying direction, an axial direction, etc. is applied between the inner and outer cylindrical fittings 10 and 12, The movable block 38.40 is the pressure receiving chamber 32.3.
4. Even when abutted against the inner surface of the movable block 38,
．． Therefore, the pressure receiving chamber 32.34 of the movable block 38.40 can be allowed to escape due to the displacement of 40.
This makes it possible to prevent as much as possible the interference with the mount's anti-vibration properties and deterioration of durability due to contact with the inner surface and interference.

Furthermore, in such a suspension bushing 16, the inner and outer cylindrical fittings 10.1 in the main vibration input direction
2 is the relative displacement amount of the movable block 3 of the inner cylinder fitting 10.
8.40, the amount of relative displacement of the connected body can be effectively defined when a large load is input, and the excessive force of the rubber elastic body 14 can be regulated. It also has the advantage of preventing deformation 1 and improving its durability.

Furthermore, in such a suspension bushing 16, the first and second pressure receiving chambers 32.
Since it is only necessary to accommodate the first and second movable blocks 38 and 40 in the 34, and no special assembly operation is required, it is possible to achieve the above-mentioned excellent protection with excellent manufacturability and cost efficiency. This makes it possible to obtain a bushing with vibration performance.

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

For example, in the embodiment described above, it is also possible to perform different tuning on the vibration acting part formed in the first pressure receiving chamber 32 and the vibration acting part formed in the second pressure receiving chamber 34. As a result, a low dynamic spring effect based on the resonance effect of the fluid can be exerted for input vibrations in two different frequency ranges.

Further, in the embodiment described above, the movable block may be housed in only one of the first pressure receiving chamber 32 and the second pressure receiving chamber 34.

Furthermore, in the embodiment, the inner and outer cylindrical fittings 10.1
Two pressure receiving chambers 32 and 34 were formed between the inner and outer cylindrical fittings 10 and 12, but three or more pressure receiving chambers are provided between the inner and outer cylindrical fittings 10 and 12. It is also possible to adopt a structure in which an orifice passage is provided to communicate internal pressure chambers with each other, and a movable block is housed and arranged in at least one of the pressure receiving chambers.

Furthermore, the structure of the orifice passage 36 is not limited to that of the embodiment described above, and for example, the orifice passage 36 may be formed on the cylindrical metal fitting side, or it may be formed on the inner circumferential surface of the outer cylindrical fitting with a length of one circumference or more in the circumferential direction. Various known structures can be employed, such as a structure formed using a steel plate.

In addition, in the above embodiment, a specific example of the application of the present invention to an automobile suspension bushing was shown, but the present invention is also applicable to an automobile engine mount, or a mounting device for various devices other than automobiles. Of course, it can also be effectively applied to.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and such embodiments include: It goes without saying that any of these methods are included within the scope of the present invention as long as they do not depart from the spirit of the present invention.

(Effects of the Invention) As is clear from the above description, the fluid-filled cylindrical mount device according to the present invention has a high resistance to human vibration in a low frequency range based on the resonance effect of the fluid flowing in the orifice passage. While ensuring a predetermined vibration isolation effect, the mount dynamic spring constant in the high frequency range is increased based on the resonance effect of the fluid in the vibration acting part formed in the pressure receiving chamber.
This can be effectively reduced or prevented, and as a result, excellent vibration damping performance can be exhibited against input vibrations in a wide frequency range.

In addition, in such a mounting device, since the movable member forming the vibration acting section is housed in a freely movable manner within the pressure receiving chamber, the movable member is moved within the pressure receiving chamber when vibrating manually in a twisting direction or a prying direction. This makes it possible to reduce as much as possible the inhibition of the mount's vibration damping performance and the decrease in durability caused by contact with the surface.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an automobile suspension bushing according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■--■ in FIG. 1, and FIG. II[-I[[ is a cross-sectional view. Also, Figure 4 shows the first
FIG. 3 is a cross-sectional view showing a vibration input state of the suspension bushing shown in the figure. 10: Inner cylinder metal fitting 12: Outer cylinder metal fitting 14: Rubber elastic body 65 4 8 0: Suspension bushing: Axial wall part 32: First pressure receiving chamber: Second pressure receiving chamber 36: Orifice passage: First Movable block: second movable block

Claims (1)

[Claims] An inner cylindrical metal fitting and an outer cylindrical metal fitting arranged at a predetermined distance from each other in the radial direction are elastically connected by a rubber elastic body interposed between them, and Between the cylindrical metal fittings and the outer cylindrical metal fittings, a plurality of incompressible fluids are each sealed inside, and internal pressure fluctuations are caused when vibration is input in a predetermined radial direction between the inner and outer cylindrical metal fittings. A fluid-filled cylindrical mount device that forms pressure receiving chambers and further includes an orifice passage that allows the pressure receiving chambers to communicate with each other and allows fluid to flow between the pressure receiving chambers, In at least one of the above, at least a part of the rubber elastic body constituting the axial wall of the mount is made into a thin part so that a predetermined amount of bulging deformation can be tolerated. A movable member having an outer peripheral surface shape that is one size smaller than the inner peripheral surface shape of the pressure receiving chamber,
By housing and arranging the movable member so as to be freely movable, a vibration acting portion having a predetermined gap is formed between the movable member and the inner surface of the pressure receiving chamber in which a fluid flow is generated when vibration is input between the inner and outer cylindrical fittings. A fluid-filled cylindrical mount device characterized by: