JPH02256924A - Fluidic elastic coupling - Google Patents

Abstract

PURPOSE:To ensure torque transmission and to attain enough vibration-proof performance, by coupling a pair of fittings for torque input-member and its output-member with rubber elastic body and by providing fluid chamber in which incompressible fluid is charged and sealed and orifices for providing communication therebetween. CONSTITUTION:A torque input side fitting 12 and output side fittings 14 are vulcanizingly fixed to a disc-shaped rubber elastic body 10. Metal sleeves 16 are also vulcanizingly fixed thereto and pockets 22 in which incompressible fluid is charged and sealed to form the first to the fourth fluid chambers 40, 42, 44, 46. Orifice passages 48, 50 are formed by an external metal cylinder 38, for communicating fluid chambers together two by two. Stopper blocks 54 are accommodated as required. Torque is transmitted from the fitting 12 through elastic deformation of the rubber elastic body 10 to the fitting 14. Then the fluid flows through the orifices 48, 50 to relieve or eliminate possible vibration under resonance phenomena thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an elastic joint that is interposed in a connecting portion of a predetermined rotating member to transmit rotational driving force, and particularly relates to an elastic joint that transmits rotational driving force between connected rotating members. The present invention relates to a structure of a fluid-filled elastic joint that can be advantageously reduced or prevented.

(Background Art) Conventionally, elastic joints have been known that are interposed between a connecting portion between a rotational force input member and a rotational force output member to transmit rotational driving force and suppress transmission of vibration between the two members. It is being For example, elastic shaft couplings that are interposed between the steering shaft of an automobile and the transmission shaft to the steering device, or between the connection part of the propeller shaft of the automobile, etc.
That's it.

By the way, in such an elastic joint, as shown in Japanese Patent Application Laid-Open No. 51-143158, etc., there is generally a drive-side mounting bracket attached to the rotational force input member side, and a rotational force output member. The driven side mounting bracket attached to the member side is connected by a rubber elastic body, and vibration transmission is suppressed based on the elasticity of the rubber elastic body. .

However, in conventional elastic joints in which the vibration-proofing properties are obtained solely by the elastic properties of the rubber elastic body, the rotational driving force is also transmitted via the rubber elastic body. It was difficult to set sufficient anti-vibration characteristics. In other words, in such an elastic joint, its vibration isolation characteristics are mainly influenced by the dynamic spring characteristics of the rubber elastic body, while its driving force transmission performance is mainly influenced by the static spring characteristics of the rubber elastic body. In general, these dynamic spring characteristics and static spring characteristics have a certain correlation, so it was not possible to soften only the dynamic spring characteristics. Therefore, it has been extremely difficult to set sufficient vibration damping characteristics while ensuring driving force transmission performance.

In particular, the dynamic spring characteristics of a rubber elastic body become harder as the frequency of input vibration increases. In order to ensure good response when operating the steering wheel, when setting the spring constant of the rubber elastic body,
This has the inherent problem that it is difficult to obtain sufficient vibration isolation performance against shimmy and the like corresponding to a frequency range of about 10 to 20 Hz.

(Problem to be solved) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problem to be solved is:
An object of the present invention is to provide an elastic joint with a novel structure that can advantageously improve vibration damping performance while ensuring sufficient rotational drive force transmission performance.

(Solution Means) In order to solve this problem, in the present invention, the rotational force is interposed between a predetermined rotational force input member and a rotational force output member, and the rotational force is transmitted from the rotational force input member to the rotational force output member. An elastic joint that transmits rotational driving force to an output member, comprising (a) a plurality of drive-side mounting brackets and driven-side mounting brackets arranged alternately at predetermined intervals around the rotation axis; b) a rubber elastic body that elastically connects the plurality of mounting brackets to each other by being fixed to the drive-side mounting bracket and the driven-side mounting bracket; and (c) an outer periphery of the rubber elastic body. (d) a metal sleeve that is integrally fixed on the surface; (e) an outer cylindrical metal fitting that is fitted onto and fixed to the outer peripheral surface of the metal sleeve to close the opening of the pocket; (f) a plurality of pockets that open in the pocket; (g) a plurality of fluid chambers filled with a predetermined incompressible fluid, which are formed by being closed by the outer cylindrical fitting; a fluid chamber located between the driving-side mounting bracket and the driven-side mounting bracket on the side where the rotational driving force is input; and the driving-side mounting bracket and the driven-side mounting bracket on the side that are separated from each other when rotational driving force is input. The fluid-filled elastic joint is characterized by having an orifice passage that communicates the fluid chambers located between the fluid chambers and the fluid chambers and allows fluid to flow between the fluid chambers.

(Function/Effect) In other words, in the fluid-filled elastic joint according to the present invention, when vibration is input between the driving side mounting bracket and the driven side mounting bracket, the vibrations may occur between them in the orifice passage. By causing internal pressure changes with opposite increases and decreases to each other in one or more pairs of fluid chambers that are communicated with each other, fluid flow through the orifice passage is caused between each pair of fluid chambers. It will be brought to life.

Therefore, in the fluid-filled elastic joint according to the present invention, by adjusting the shape etc. of the orifice passage and tuning the resonant frequency of the fluid flowing therein to a predetermined frequency range, Based on the resonance effect of the fluid in the rubber elastic body, the dynamic spring constant can be reduced when vibration is input in a desired frequency range. This makes it possible to extremely advantageously improve the vibration damping performance while ensuring the same level as possible.

(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 a specific example of the present invention applied to a so-called steering joint, which is interposed between a steering shaft of an automobile and a transmission shaft to a steering device. ing. In this figure, 10 is a rubber elastic body, and is formed in the shape of a substantially thick disk as a whole.

A pair of first mounting brackets each having a cylindrical shape are located on both sides in the radial direction across the axis of the rubber elastic body 10 and are respectively attached to a handle shaft serving as a rotational force input member (not shown). 12 and 12 are respectively disposed passing through the rubber elastic body 10 in the axial direction,
They are integrally vulcanized and bonded, and on the other hand, on both sides in the radial direction perpendicular to the axis of the rubber elastic body 10 with respect to the opposing direction of the pair of first mounting brackets 12 and 12. A pair of cylindrical second mounting fittings 14 and 14, which are positioned and attached to a power transmission shaft to a steering device serving as a rotational force output member (not shown), each axially rotate the rubber elastic body 10. It is disposed so as to penetrate through it and is integrally vulcanized and bonded.

That is, each pair of first mounting brackets 12.12 and second mounting brackets 14.14 are arranged alternately at a predetermined distance in the circumferential direction on substantially the same circumference, Furthermore, these first and second fittings 12, 14 are integrally and elastically connected to each other by means of a rubber elastic weight zero. In addition, here, the -th
The fact that the second mounting brackets 121.14 are arranged approximately on the same circumference means that when rotational driving force is input from the handle shaft to the first mounting brackets 12.12, the second mounting brackets 121.14 This refers to an arrangement form in which compressive and tensile stress can be effectively generated on the rubber elastic body 10 interposed between the first mounting bracket 12 and the second mounting bracket 14 in the circumferential direction. , does not refer strictly to the circumference of a circle. In addition, in this embodiment, the first mounting metal fittings 2,
The tool 2 constitutes a driving-side mounting bracket, and the second mounting bracket 14, 14 constitutes a driven-side mounting bracket.

Further, a metal sleeve 16 is integrally vulcanized and bonded to the outer peripheral portion of the rubber elastic body 10. Here, the metal sleeve 16 to be bent is constituted by a pair of semi-cylindrical half fittings 18.18, and as shown in FIGS. 4 and 5, these halves are Opposing surfaces on both sides in the circumferential direction of the split fittings 18.18 are vulcanized and bonded to the rubber elastic body 10 in a state in which they face each other with a predetermined gap apart from the first mounting fitting 12.12 in the opposing direction. Rubber elastic body 1 that loosens as it moves
0, a recessed groove-shaped cavity 20 is formed between the opposing surfaces of the half fittings 18 and 18 and extending over the entire length in the axial direction.

Furthermore, pocket portions 22 are formed in the rubber elastic body 1o at four locations located between the first mounting bracket 12 and the second mounting bracket 14 facing each other in the circumferential direction. , and the window portion 3 provided in the half-split fitting 18
0, and are each opened on the outer circumferential surface.

In particular, in this embodiment, these four pocket portions 22 are respectively connected to the pair of first mounting fittings 12.
．． It is formed with a substantially rectangular recess shape extending along the opposing direction of the second mounting fittings 12, and
It is formed to extend inward in the opposing direction. Also,
A hard plate material 32.
32 is placed under the buried state, and both ends thereof are
It is secured to the first fitting 12.12. Then, rotational driving force is inputted to the first mounting bracket 12.12, and the second mounting bracket 12.12
is displaced in the circumferential direction with respect to the second mounting bracket 14.14, the hard plates 32.32 are rotationally displaced around the axis of the rubber elastic body 10, thereby
Compression and tensile deformation can be more effectively produced on the rubber elastic body 10 interposed between the first mounting bracket 12 and the second mounting bracket 14 in the circumferential direction, and thus each pocket portion 22 A volume change within the interior can advantageously be produced.

Further, the rubber elastic body 10 is integrally rotated around the outer circumferential surface of the half fitting 18.18, so that it covers substantially the entire outer circumferential surface of the half fitting 18.18.
A seal rubber layer 34 of a predetermined thickness is formed.

Further, the seal rubber layer 34 formed on the outer circumferential surface of each of these half metal fittings 18 has a sealing rubber layer 34 extending linearly in the circumferential direction of the half metal fitting 18, sandwiching the second mounting metal fitting 14, and extending around the circumference thereof. Pairs of pocket portions 2 located on both sides of the direction
A circumferential groove 36 connecting the openings of 2.2 and 22 is formed. Here, in each pair of pocket portions 22.22 connected by the circumferential groove 36, the first mounting bracket 12.
When a rotational driving force is input to the second mounting bracket 12, the first mounting bracket 12 is positioned on the side where it is brought closer to the second mounting bracket 14 and the side where it is separated from the second mounting bracket 14, and the relative volume is Change is about to occur.

Then, the integrally vulcanized product of the rubber elastic body 10 having such a structure is press-fitted into the outer cylindrical fitting 38, and then the outer cylindrical fitting 38 is further subjected to diameter reduction processing such as hemographic drawing. As a result, the outer cylindrical fitting 38 is integrally fitted to the metal sleeve 16, as shown in FIGS. 1 to 3.

Moreover, by externally covering the outer cylindrical metal fitting 38,
The openings of the pocket portion 22 are respectively closed and sealed, and a predetermined incompressible fluid is sealed therein, thereby forming the first fluid chamber 40 and the second fluid chamber 42.
, a third fluid chamber 44, and a fourth fluid chamber 46, respectively. Furthermore, the opening of the circumferential groove 36 is also
The first fluid chamber 40 and the second fluid chamber 42 are closed by an outer cylindrical fitting 38, thereby communicating the first fluid chamber 40 and the second fluid chamber 42 with each other and allowing fluid to flow between the two fluid chambers 40 and 42. The first orifice passage 48 and the third fluid chamber 44 and fourth fluid chamber 46 are communicated with each other, and both fluid chambers 44.4 are connected to each other.
a second orifice passage 5 that allows fluid to flow between 6 and 6;
0, respectively.

The filling and sealing of the fluid into each of the fluid chambers 40, 42, 44, 46 is performed by inserting the outer cylindrical fitting 38 into the integrally vulcanized molded product in a predetermined incompressible fluid. By doing so, you can be advantageous. In addition, the liquid tightness in each of these fluid chambers 4o, 42, 44, 46 and orifice passage 48, 50 is determined by the metal sleeve 1.
6 (half fittings 18, 18) and the outer cylindrical fitting 38, the sealing rubber layers 34, 34 are compressed. , two annular sealing lips 52.52 are formed on the outer peripheral surface of each half metal fitting so as to surround the opening of each pair of pocket portions 22.22 connected by each circumferential groove 36. By doing so, the sealing performance is further improved.

Furthermore, when the outer cylindrical fitting 38 is packaged as described above, a stopper block 54 of a predetermined thickness made of a hard material such as resin is accommodated in each pocket portion 22 of the integrally vulcanized molded product. By being fixed to the inner surface of each pocket portion 22, the first to fourth fluid chambers 40, 42.
44.46. When the rotational driving force is input to the first mounting bracket 12.12, excessive relative displacement in the circumferential direction between the first mounting bracket 12 and the second mounting bracket 14 causes the stopper block 5
This is defined by the contact of the inner surface of the fluid chamber with respect to the inner surface of the fluid chamber 4, and excessive deformation of the rubber elastic body 10 can be prevented.

Furthermore, by press-fitting the integrally vulcanized molded product into the outer cylindrical metal fitting 3, the pair of half-split fittings 18 and 18 are moved toward each other in the direction of approaching each other, and their opposing surfaces on both sides in the circumferential direction are brought into contact with each other. Thus, the annular metal sleeve 6 is configured. As the half fittings 18.18 move in the approaching direction, the empty space 2
This causes an elastic deformation that crushes the rubber elastic body 10, so that effective pre-compression can be performed during the sheathing operation of the outer cylindrical fitting 38 without requiring any special diameter reduction processing for the rubber elastic body 10. They can be done at the same time.

That is, in the steering joint having the above-described structure, when rotational driving force is applied from the steering wheel shaft to the first mounting brackets 12 and 12 by steering operation, the first mounting brackets 12 and 12 .12 is displaced relative to the second mounting bracket 14.14 in the circumferential direction, causing elastic deformation of the rubber elastic body 10 interposed between the remounting brackets 12.14. As a result, relative internal pressure changes occur between the first fluid chamber 40 and the second fluid chamber 42 and between the third fluid chamber 44 and the fourth fluid chamber 46, respectively.
Fluid flow is thereby induced through the first and second orifice passages 48,50 interconnecting the pairs of fluid chambers.

Therefore, in such a steering joint, such first and second orifice passages 48
．． By tuning the flow cross-sectional area and length of the orifice passages 48 and 50 according to the viscosity of the sealed fluid and the elasticity of the rubber elastic body 10, the fluid flows through the orifice passages 48 and 50 when vibrations in a predetermined frequency range are input. Based on the resonance effect of the fluid, the effect of reducing the dynamic spring constant can be effectively exhibited. In this embodiment, both the first and second orifice passages 48 and 50 are caused by the resonance effect of the fluid flowing inside them.
It is tuned so that a low dynamic spring effect can be exhibited when vibration is applied manually in the frequency range of about 10 to 207, thereby effectively alleviating or eliminating steering vibrations such as shimmy. .

Therefore, in such a steering joint, vibration isolation is required while setting a static spring constant for the rubber elastic body lo itself to ensure sufficient rotational drive force transmission performance. The dynamic spring constant in the frequency range can be reduced by the resonant action of the fluid flowing through the first and second orifice passages 48, 50, whereby a joint with excellent vibration damping performance is advantageous. It can be realized.

In particular, in the steering joint in this embodiment, the first to fourth fluid chambers 40, 42, 44
．． The volume change during vibration input of 46 is the hard plate material 32.
As a result, the flow rate of the fluid through the first and second orifice passages 48,50 can be advantageously ensured, thereby achieving a low dynamic spring effect due to the fluid resonance effect as described above. , can be demonstrated more effectively.

Furthermore, in the steering joint in this embodiment, the first and second orifice passages 48,50
are formed between the metal sleeve 16 and the outer cylindrical fitting 38, respectively, so that changes in the flow path shape when rotational driving force or vibrations are input can be prevented as much as possible. It also has the advantage that the desired low dynamic spring effect can be advantageously and stably exhibited.

Furthermore, in the steering joint in this embodiment, excessive circumferential displacement of the first mounting bracket 12.12 with respect to the second mounting bracket 14.14 and excessive deformation of the rubber elastic body 10 may cause the stopper block 54 to Since this can be effectively prevented, the durability of the joint can be advantageously ensured.

In addition, in the steering joint in this embodiment, the metal sleeve 16 is constituted by the half metal fittings 18 and 18, so that the rubber elastic body 10 can be subjected to effective preliminary compression without requiring any special operation. can be added, it is possible to manufacture a joint with excellent durability and good manufacturability.

Although the embodiments of the present invention have been described in detail above,
This is a literal illustration, and the present invention should not be construed as being limited only to this specific example.

For example, the hard plate material 32 and the stopper block 54 are both appropriately employed as needed, and are not essential to the present invention.

Furthermore, the specific shapes and structures of the fluid chamber and orifice passage are not limited to those of the embodiments described above.

Furthermore, said first and second orifice passages 48.50
It is also possible to perform different tuning for each of them, thereby making it possible to obtain a low dynamic spring effect based on the resonance effect of the fluid with respect to input vibrations in two different frequency ranges.

Further, the rubber elastic body 10 may have various shapes such as an annular shape or a polygonal shape in addition to the disk-like shape shown in the example.

Furthermore, the drive side mounting bracket and the driven side mounting bracket,
It is also possible to provide three or more of each. In such a case, a fluid chamber is formed between each drive-side mounting bracket and driven-side mounting bracket to form three or more pairs of fluid chambers that are communicated with each other through orifice passages. This also becomes possible.

In addition, although the above-mentioned embodiment shows a specific example in which the present invention is applied to a steering joint of an automobile, the present invention can also be applied to various other applications such as a coupling installed in a propeller shaft of an automobile. It goes without saying that the present invention can be advantageously applied to various types of elastic joints interposed between rotary driving force transmitting members.

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 may be different from the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not depart from the spirit of the invention.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a specific example of an automobile steering joint to which the present invention is applied;
The figure is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a
It is a sectional view taken along the line ■-■ in FIG. 1. Also, Figure 4 shows
5 is a cross-sectional view showing an integrally vulcanized molded product constituting the steering joint shown in FIG. 1, and FIG.
5 is a view taken along arrow a in FIG. 4. FIG. 10: Rubber elastic body 12: First mounting bracket (driving side mounting bracket) 14: Second mounting bracket (driven side mounting bracket) 16: Metal sleeve
22: Pocket portion 30: Window portion 38: Outer cylinder metal fitting '40: First fluid chamber 42: Second fluid chamber 44:
Third fluid chamber 46: Fourth fluid chamber 48: First orifice passage 50: Second orifice passage Applicant Tokai Rubber Industries Co., Ltd. Third factor

Claims (1)

[Scope of Claims] An elastic joint that is interposed between a predetermined rotational force input member and a rotational force output member to transmit rotational driving force from the rotational force input member to the rotational force output member, A plurality of drive-side mounting brackets and driven-side mounting brackets are arranged alternately around the axis at predetermined intervals, and each of the drive-side mounting brackets and driven-side mounting brackets is fixed to each other. a rubber elastic body that elastically connects the plurality of mounting fittings to each other; a metal sleeve integrally fixed on the outer peripheral surface of the rubber elastic body; the drive-side mounting fitting of the rubber elastic body; a plurality of pockets that penetrate the metal sleeve and open to the outer circumferential surface, provided between the driven side mounting bracket;
an outer cylindrical fitting that closes an opening of the pocket; and a plurality of fluids in which a predetermined incompressible fluid is sealed, the openings of which are closed by the outer cylindrical fitting within the pocket. Among these fluid chambers, a fluid chamber located between the driving side mounting bracket and the driven side mounting bracket on the side that are brought closer to each other when rotational driving force is input, and An orifice passageway that communicates fluid chambers located between the drive-side mounting bracket and the driven-side mounting bracket that are separated from each other and allows fluid to flow between the fluid chambers. A fluid-filled elastic joint characterized by: