JPH03239816A - Elastic joint containing cord - Google Patents

Abstract

PURPOSE:To reduce transmission of vibration by providing a spherical slide bushing, which is provided with an inner member having a spherical projected section and an inner member having a spherical recessed section, on the inside of a rotation drive shaft mounting hole and a mounting hole on the rotated shaft side which are arranged alternately around a rotary central shaft. CONSTITUTION:A mounting hole 12 on the rotation drive side and a mounting hole 14 on the rotated side are alternately arranged on each apex of a rubber elastic body 10 which forms a plane hexagon in the peripheral direction of rotary shaft. A cord member 20 is wound over them. Spherical contact bushings 28 are positioned in both mounting holes 12, 14. A spherical projected section 34 is formed in a metallic inner cylinder 30 of a spherical slide bushing, and a spherical recessed section 34 is formed in an outer cylinder 32 made of synthetic resin. The spherical projected and recessed sections slide on spherical face via an elastic slide body 38. Rigidity in the direction of bending for the rotary shaft is reduced owing to the joint structure, and transmission of vibration between the connected members is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a corded elastic joint that is interposed in a connecting portion of a predetermined rotating member to transmit rotational driving force, and in particular, the present invention relates to a corded elastic joint that is interposed at a connecting portion of a predetermined rotating member and transmits rotational driving force, and in particular has reduced rigidity in the bending direction with respect to the rotating shaft. The present invention relates to a corded elastic joint that can advantageously reduce or prevent transmission of vibration between connected members.

(Background Art) Elastic joints have been known that are interposed between a connecting portion between a rotary driving member and a rotated member, and transmit rotational driving force while suppressing transmission of vibration between the two members. There is. For example, a coupling part of a propeller shaft of an automobile or an elastic shaft coupling interposed between a steering shaft of an automobile and a transmission shaft to a steering device are examples thereof.

By the way, as shown in Japanese Unexamined Patent Application Publication No. 55-63428, etc., such elastic joints have conventionally been made by attaching each rubber elastic body to a rubber elastic body that has an approximately disk shape or an annular shape as a whole. A structure is known in which a plurality of rotation drive side mounting holes and rotation target side mounting holes are provided alternately on the same circumference around the rotation center axis and passing through in a direction parallel to the rotation center axis. However, in elastic joints with such a structure, since the rotational driving force is transmitted through the rubber elastic body, the responsiveness of the transmitted rotational driving force is poor, and the rubber elastic There were problems in that the body was prone to breakage and it was difficult to ensure sufficient durability.

Therefore, in recent years, as shown in Japanese Utility Model Application Publication No. 64-27532, etc., for such a rubber elastic body, the outer periphery of the rotationally driving side mounting hole and the rotating side mounting hole that are adjacent in the circumferential direction. A so-called elastic joint with a cord, which has a structure in which a cord member made of a predetermined fiber material is embedded and arranged in a wound state across the sections, has come to be suitably used.

According to such a cord-containing elastic joint, when the rotational driving force is manually applied, the cord member is tensed, thereby exhibiting stiff spring characteristics, resulting in good responsiveness and durability. On the other hand, under a situation where no rotational driving force is input, the cord member becomes slack, and a relatively soft spring characteristic can be ensured.

However, in such corded elastic joints,
High rigidity cannot be avoided by arranging the cord member within the rubber elastic body, and this poses an inherent problem in that the vibration damping properties are impaired.

In addition, in view of this problem, a cylindrical inner cylindrical metal fitting and an outer cylindrical metal fitting are installed in the rotation drive side mounting hole and the rotationally rotated side mounting hole of the rubber elastic body, respectively, and a cylindrical shaped metal fitting interposed between them. There has also been proposed a structure in which a rotationally driven member and a rotated member are attached via a rubber bushing integrally connected by a rubber body.

However, by providing such a rubber bushing, although it is possible to reduce the rigidity of the elastic joint in the direction parallel to the rotation axis and the direction perpendicular to the rotation axis, the rigidity in the bending direction with respect to the rotation axis is reduced. Since it is extremely difficult to do so, there was a problem in that the vibration damping characteristics were extremely poor against vibrations exerted on the rotating shaft in the bending direction.

Therefore, for example, due to the joint angle of the propeller shaft of a car, a large stress in the bending direction is generated in the connection part of the propeller shaft, which causes vibrations such as rolling of the car body when driving at low speeds. It was.

(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:
The stiffness in the bending direction relative to the axis of rotation can be advantageously reduced,
An object of the present invention is to provide a corded elastic joint that can exhibit excellent vibration damping characteristics against input vibrations in the bending direction between connected members.

(Solution Means) In order to solve this problem, in the present invention, as described above, each of the plurality of rotational drive side mounting holes and rotational side mounting holes are located on the same circumference around the rotation center axis. For the rubber elastic bodies provided alternately and penetrating in a direction parallel to the rotational center axis, the rubber elastic bodies are provided so as to straddle between the outer peripheries of the rotation drive side mounting holes and the rotated side mounting holes that are adjacent to each other in the circumferential direction. In each of the corded elastic joints in which a cord member made of a predetermined fiber material is buried and arranged in a wound state, an inner member having a spherical convex portion on the outer circumferential surface of an axially intermediate portion; It consists of a cylindrical outer member disposed on the outside of the inner member and having a spherical concave portion corresponding to the spherical convex portion of the inner member on the inner circumferential surface of an axially intermediate portion, and the cylindrical outer member has a spherical concave portion corresponding to the spherical convex portion of the inner member. Spherical sliding bushes that are allowed to slide spherically in the fitting portion with the spherical recess of the outer member are respectively disposed in the rotation drive side mounting hole and the rotation target side mounting hole of the rubber elastic body, and the outer member is mounted in the mounting hole, and the rotationally driven member and the rotated member are respectively mounted to the inner member.

(Operation/Effect) That is, in the corded elastic joint constructed according to the present invention, the rotationally driven member and the rotated member are both attached to the elastic joint via the spherical sliding bushing. As a result, each of the elastic joints of the rotationally driven member and the rotated member is
At the attachment site, displacement in the bending direction with respect to the rotation axis can be tolerated with low rigidity.

Therefore, according to the corded elastic joint having such a structure, there is no reduction in the transmission function of the rotational driving force between the rotational driving member and the rotated member, and the rotational axis of rotation between the rotational driving member and the rotating member is not reduced. The rigidity against displacement in the bending direction can be extremely advantageously reduced, and as a result, the vibration isolation characteristics against input vibration in the bending direction between connected members, which has been a problem in the past, can be dramatically improved. That's what happened.

(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 and 2 show a specific example in which the present invention is applied to a coupling interposed in a connecting portion of a propeller shaft of an automobile. In these figures, 10 is a rubber elastic body, which is formed to have a regular hexagonal frame shape in plan view.

Further, each vertex of the regular hexagon in the rubber elastic body 10 has a rotation drive side mounting hole 12 through which a Rondo member provided on the transmission side shaft as a rotation drive member is inserted and attached, and a differential as a rotated shaft. Rotated side attachment holes 14, into which the rond members provided on the side shafts are inserted and attached, are provided alternately in the circumferential direction and in parallel to the axial direction. That is, as a result, a plurality of (in this embodiment, three) rotation drive side attachment holes 12 and rotated side attachment holes 14 are arranged alternately on the same circumference around the axis of the rubber elastic body IO. They are formed parallel to each other at equal distances from each other. Note that the rubber elastic body 1
At the center of each side of the regular hexagon at 0, a rearward hole 16 is formed which penetrates in the axial direction.

Further, a thin-walled cylindrical collar metal fitting 18 is inserted into the rotary drive side mounting hole 12 and the rotated side mounting hole 14, respectively, and is integrally connected to the rubber elastic body 10 on the outer circumferential surface thereof. It is vulcanized and bonded.

Further, each of these collar fittings 18 is provided with a cord member 20 made of a predetermined fiber material so as to straddle between adjacent collar fittings 18 in the circumferential direction. is wrapped around. In other words, each of the cord members 20 is wound into a flat ring shape, and the outer periphery of each adjacent rotary drive side attachment hole 12 and rotated side attachment hole 14 provided in the rubber elastic body 10 is The rubber elastic body 10 is placed in a buried state on each side of the rubber elastic body 10 across the gap. Note that as the cord member 20, it is also possible to use synthetic fibers such as polyester in addition to metal wires such as steel wires.

Furthermore, particularly in this embodiment, two grooved metal fittings each having a substantially U-shaped cross section are provided with circumferential grooves 22 opening on the outer circumferential surface of each collar metal fitting 18 at the axially central portion thereof. 24 and 24 are fitted and fixed two by two in contact with each other in the axial direction. The cord member 2 is wound between adjacent collar metal fittings 18 and 18.
0 is the circumferential groove 2 of each corresponding groove fitting 24.24, respectively.
2.22, and is wound between the corresponding groove fittings 24.24.

Furthermore, in the rubber elastic body 10 having the structure as described above, the rotation drive side mounting hole 2 and the rotation target side mounting hole 14
A spherical sliding bush 28 is disposed within the inner hole 26 of each collar fitting 18 disposed therein.

The spherical sliding bushing 28 includes a metal inner cylinder 30 having a thick-walled cylindrical shape, and a synthetic resin outer cylinder having a cylindrical shape and arranged at a predetermined distance on the outside of the inner cylinder 30 in the radial direction. It is equipped with 32.

Further, the inner cylinder 30 is formed with a spherical convex portion 34 having a spherical outer peripheral surface at its axially central outer peripheral portion, while the outer cylinder 32 has a spherical convex portion 34 formed at its axially central inner peripheral portion. In this case, a spherical recess 36 is formed having a spherical inner circumferential surface that substantially corresponds to the outer circumferential surface of the spherical convex portion 34 . Then, the inner cylinder 30 is placed inside the spherical recess 36 of the outer cylinder 32.
The spherical convex portion 34 is disposed in a housed state.

Furthermore, an elastic sliding body 38 having a substantially cylindrical shape is interposed between the spherical concave portion 36 of the outer cylinder 32 and the spherical convex portion 34 of the inner cylinder 30 accommodated therein. Cylinder 32
It is held in a spherical recess 36 of. As shown in an enlarged view in FIG. 3, this elastic sliding contact body 38 is disposed so as to cover the outer peripheral surface of the spherical convex portion 32 of the inner cylinder 30.
A cylindrical sliding cloth 40 made of a low-friction material such as Teflon,
A cylindrical rubber sheet 4 arranged on the outer peripheral surface of the sliding cloth 40
2 are integrally constructed.

In addition, in the elastic sliding body 38, both end faces in the axial direction are formed at stepped portions 44, 44 formed on the outer cylinder 32.
By being held in the axial direction, it is held integrally with the outer cylinder 32.

As a result, the inner cylinder 30 is assembled and held with respect to the outer cylinder 32 via the elastic sliding member 38, and thus the spherical convex portion 34 of the inner cylinder 30 is
It is elastically and spherically slidably connected to the spherical recess 36 of the outer cylinder 32. As is clear from the above description, in this embodiment, the inner tube 30 constitutes an inner member, while the outer tube 32 and the elastic sliding body 38 constitute an outer member. It is.

Further, an annular dust cover 46 is disposed between the corresponding axial ends of the inner cylinder 30 and the outer cylinder 32, and protects the spherical convex portion 34 and the spherical concave portion 36 from the rubber elastic thin film. The spherical sliding portion of the holder is sealed from the outside space. Furthermore, a lubricant such as grease to be supplied to the spherical sliding portion is appropriately sealed between the dust covers 46 and 46.

In order to manufacture the spherical sliding bushing 28 having the above structure, for example, first the inner cylinder 30 and the elastic sliding body 38 are shaped separately, and the elastic sliding body 38 is formed into a spherical convex shape on the inner cylinder 30. After the inner tube 3o is placed on the outer peripheral surface of the portion 34, the inner tube 3o is placed in a molding cavity that forms the outer tube 32, and a predetermined resin material is filled into the cavity to form the outer tube. This can be advantageously achieved by holding the elastic sliding member 38 against the spherical recess 36 of the outer cylinder 32 simultaneously with the molding of the outer cylinder 32. Further, as the resin material constituting the outer cylinder 32, any material such as a thermoplastic resin such as nylon or acetal, or a thermosetting resin such as epoxy or phenol can be used; Reinforcement composite resins in which glass fibers, carbon fibers, whiskers, etc. are added to such resins to improve their strength are also suitably employed.

And, the spherical sliding bush 28 having such a structure
In this case, the outer cylinder 32 is fitted into the inner hole 26 of the collar fitting 18 disposed in the rotation drive side attachment hole 12 and the rotated side attachment hole 14 of the rubber elastic body 10, respectively. , are integrally assembled by adhesive treatment as required.

In other words, in the coupling structure as described above,
The rond members provided on the transmission side shaft and the differential side shaft are connected to each mounting hole 1.
2. Inner cylinder 3 of spherical sliding bush 28 disposed within 14
By being inserted into and fixed to 0, it is inserted into the tubes of the transmission side shaft and the differential side shaft, thereby connecting the two shafts.

Therefore, in a coupling having such a structure, bending with respect to the rotation axis is achieved at each attachment site of the transmission side shaft and the differential side shaft based on the spherical sliding of the spherical sliding bushing 28 arranged there. Bending displacement in this direction can be tolerated with low rigidity.

Therefore, in such a coupling, it is possible to extremely effectively reduce the stiffness in the bending direction between the connected members while ensuring good transmission or responsiveness of the rotational driving force by the cord member 20. As a result, the occurrence of bending stress at the propeller shaft connection portion can be advantageously reduced or prevented, and vibrations such as rolling vibrations of the vehicle body during low-speed driving can be extremely effectively suppressed. You will get it.

Incidentally, when we measured the rigidity in the bending direction with respect to the rotating shaft of a coupling with the above-mentioned structure, we found that it was lOO
kg-cm/deg, while 30 kg-c
m/deg, and it was confirmed that the bending stiffness could be reduced to 1/3 or less.

In addition, in the camp ring in this embodiment, since the outer member that holds the inner cylinder 30 in a spherically slidable manner includes the elastic sliding body 38 having the rubber sheet 42, the rotating shaft Based on the elasticity of the rubber sheet 42, superior vibration-proofing effects can be exhibited not only in the bending direction but also in the direction parallel to or perpendicular to the input vibration.

Furthermore, in the coupling in this example,
Since the outer cylinder 32 constituting the spherical sliding bush 28 is made of resin, the inner cylinder 30 and the elastic sliding body 38 can be assembled at the same time as the outer cylinder 32 is formed, and it can be manufactured with excellent manufacturability. It also has the advantage of being able to

Although the embodiments of the present invention have been described in detail above, these are literal illustrations, and the present invention is not to be construed as being limited only to these specific examples.

For example, in the embodiment, with respect to the rotation drive side attachment hole 12 and the rotation target side attachment hole 14 in the rubber elastic body 10,
Although a collar metal fitting 18 was disposed in each case, the outer member of the spherical sliding bushing 28 is directly fixed to the inner circumferential surface of the mounting hole 12, 14 without disposing the collar metal fitting 18. You can do it like this.

Further, the shape of the rubber elastic body IO, the arrangement form and number of the rotation drive side mounting holes 12 and the rotationally driven side mounting holes 14, etc. are not limited in any way, and may vary depending on the member to which the elastic joint is to be attached. , should be changed as appropriate.

Further, the specific structure of the spherical sliding bush is by no means limited to that of the embodiment described above, and any of various known structures may be employed. for example,
Due to the spherical concave surface formed on the outer cylinder 32, the rubber sheet 4
It is also possible to directly hold the spherical convex portion 34 of the inner cylinder 30 without intervening the outer cylinder 32, and it is also possible to form the outer cylinder 32 from a metal material. Furthermore, by providing an elastic layer on the outer circumferential surface of the outer cylinder 32, it is possible to improve the vibration isolation characteristics against vibrations applied by humans in directions parallel to or perpendicular to the rotation axis.

In addition, in the embodiment described above, an example was shown in which the present invention was applied to a coupling interposed in a connecting portion of a propeller shaft of an automobile, but the present invention also includes the following:
The present invention can be effectively applied to steering couplings of automobiles, or to joint devices interposed in connecting parts of rotating members in various devices other than automobiles.

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 gist of the present invention.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention applied to a coupling interposed in a connecting portion of a propeller shaft of an automobile, and FIG.
−■ It is a sectional view. Moreover, FIG. 3 is an enlarged sectional view showing a main part of the spherical sliding push that constitutes the coupling shown in FIG. 1. 10: Rubber elastic body 12; Rotation drive side mounting hole 14: Rotated side mounting hole 28: Spherical sliding bush 32; Outer cylinder 36: Spherical recess 40: Sliding cloth 20: Coating member 30: Inner cylinder 34: Spherical convexity Part 38: Elastic sliding contact body 42: Rubber sheet

Claims (1)

[Scope of Claims] An elastic joint that is interposed between a connecting portion of a predetermined rotary drive member and a rotated member to connect the two members, the elastic joint having a plurality of mounting holes on the rotation drive side and a rotation target side. For a rubber elastic body in which mounting holes are provided alternately on the same circumference around the rotational center axis and penetrating in a direction parallel to the rotational center axis, these rotation drive side mounting holes and rotationally rotated side mounting holes In a corded elastic joint in which a cord member made of a predetermined fiber material is buried and arranged in a wound state between the outer peripheries of adjacent ones in the circumferential direction, the outer periphery of the axially intermediate portion an inner member having a spherical convex portion on a surface thereof; and a cylindrical outer member having a spherical concave portion corresponding to the spherical convex portion of the inner member on the inner circumferential surface of an axially intermediate portion disposed on the outside of the inner member. A spherical sliding bush that allows spherical sliding at the fitting portion between the spherical convex portion of the inner member and the spherical concave portion of the outer member; The corded elastic member is arranged in a mounting hole, and the outer member is mounted in the mounting hole, and the rotationally driven member and the rotated member are respectively mounted to the inner member. Fittings.