JP2017219103A - Vibration absorbing bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner cylinder type vibration absorbing bush capable of having low spring characteristics at both two directions orthogonal to each other and showing no positional deviation under its assembled state for its mating component.SOLUTION: This invention relates to a vibration absorbing bush in which a rubber elastic body is arranged on an outer peripheral side of an inner cylinder, the vibration absorbing bush having a structure in which it is assembled to a cylindrical inner surface part of a mating component arranged on an outer peripheral side of the elastic body, each of an axially perpendicular cross-sectional shape of the cylindrical inner surface part and an axially perpendicular cross-sectional shape of an outer peripheral surface of the elastic body is rectangular in shape, a clearance is set between it and the cylindrical inner surface part around the outer peripheral surface of the elastic body, a corner part of the outer peripheral surface of the elastic body is provided with a protrusion shape and the protrusion shape is assembled to an inner surface corner part of the cylindrical inner surface part. In addition, the vibration absorbing bush has a structure in which an assembling angle of the protrusion shape against the inner surface corner part at the cylindrical inner surface part is changed by changing lengths of a lateral side and a vertical side at the square part or a ratio in lengths at the time of design, thereby spring characteristics of the elastic body are adjusted.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an anti-vibration bush according to an anti-vibration technique. The anti-vibration bush of the present invention is used for a mounting device for a vehicle such as an automobile.

  Conventionally, as an anti-vibration bush, an anti-vibration bush of an inner / outer cylinder type in which a rubber-like elastic body is provided between an inner cylinder and an outer cylinder, and an inner cylinder type in which a rubber-like elastic body is provided on the outer peripheral side of the inner cylinder Anti-vibration bushes are known, and the latter inner cylinder type anti-vibration bush has fewer parts than the former inner / outer cylinder type anti-vibration bush (no outer cylinder), making it easy to manufacture and handle. Bush products are advantageous in terms of cost. These anti-vibration bushes have their respective rigiditys set in the axial direction (center axis direction), the direction perpendicular to the axis, the torsional direction, and the twisting direction based on their shapes.

  Anti-vibration bushes used in mounting devices for vehicles such as automobiles have the main functions of reducing vibration transmission and supporting the body frame. A rigid rubber material is suitable for each, and a spring characteristic contrary to one vibration-proof bushing is required.

  In general, anti-vibration bushes are shaped so that low rigidity is input in the axial direction and torsional direction, which is a shear characteristic, and high rigidity is input in the direction perpendicular to the axis and twisting direction, which is a compression characteristic. However, there are cases where the required characteristics and the bushing mounting direction cannot be adapted due to the layout of the actual machine.

  In addition, different characteristics may be required in two directions orthogonal to each other, such as the vertical direction and the horizontal direction of the vehicle, the vertical direction and the longitudinal direction, and the longitudinal direction and the lateral direction, as shown in FIG. Further, there has been developed a straight type vibration isolating bush 51 provided with a straight part (space part) 53 penetrating in the axial direction in a part of the circumference of the elastic body 52 (hereinafter referred to as this type of vibration isolating bush 51). , The direction in which the straight portion 53 does not exist is defined as the direction perpendicular to the axis (X direction in the drawing), and the direction in which the straight portion 53 exists is defined as the straight direction (Y direction in the drawing).

JP 2006-17312 A

However, there is room for further improvement in this anti-vibration bush 51 in the following points.
(1) The straight direction (Y direction) is a low spring due to a shear component spring, but the perpendicular direction (X direction) is a high spring due to a compression component spring, so the range in which the spring characteristics can be adjusted is limited. ing.
(2) Lowering the filling rate of the elastic body 52 tends to be a low spring as a whole, but in the case of the inner cylinder type, in the assembled state to the mating part such as the housing, the rotational direction (bush circumferential direction) Misalignment may occur.

  In view of the above points, the present invention can provide a low-spring characteristic in both directions orthogonal to each other in an internal cylinder type vibration-proof bushing, and may cause a displacement in the assembled state to the mating part. Aim to provide no anti-vibration bushing.

  In order to achieve the above object, the vibration isolating bush of the present invention is a vibration isolating bush provided with a rubber-like elastic body on the outer peripheral side of the inner cylinder, and the cylindrical shape of the counterpart component disposed on the outer peripheral side of the elastic body. In the anti-vibration bush to be assembled to the inner surface, the axially perpendicular cross-sectional shape of the cylindrical inner surface and the axially perpendicular sectional shape of the outer peripheral surface of the elastic body are respectively rectangular, and the cylindrical inner surface around the outer peripheral surface of the elastic body A gap is set between the elastic body, a protrusion shape is provided at a corner portion of the outer peripheral surface of the elastic body, and the protrusion shape is assembled to an inner surface corner portion of the cylindrical inner surface portion.

  In the vibration-proof bushing of the present invention having the above-described configuration, the protrusion shape provided at the corner portion of the outer peripheral surface of the elastic body having a quadrangular section is assembled to the inner corner portion of the cylindrical inner surface portion of the counterpart part having the same quadrangular section. Thus, the anti-vibration bush is mounted on the mating part, and in this mounted state, a curb portion is set around each of the elastic bodies due to the gaps. In addition, since the protrusion shape is provided in an oblique direction and has a spring characteristic of a compression + shear component, a lower spring is realized as compared with a spring characteristic of only the compression component. Therefore, from these, it is possible to make both the horizontal side direction and the vertical side direction in the cross-sectional quadrilateral have low spring characteristics.

  In addition, since the quadrangular cross-sections are combined, and the projection shape provided at the four corners of the inner square is assembled to the inner corners provided at the four corners of the outer square, the projection shape is prevented from rotating with respect to the counterpart part Is done. Therefore, it is possible to prevent the vibration-proof bushing from being displaced in the rotational direction in the assembled state with the counterpart part.

  In addition, the quadrilateral cross-sections are combined, and the protrusion shape provided at the four corners of the inner quadrangle is assembled to the inner corners provided at the four corners of the outer quadrangle. If the length or length ratio of the lateral and vertical sides of the outer rectangle is changed, the mounting angle is changed, and the spring characteristics in the horizontal and vertical directions are changed accordingly. Is done. Therefore, by changing the length or length ratio of the horizontal and vertical sides of the rectangular cross section, the assembly angle of the protrusion shape with respect to the inner corner of the cylindrical inner surface is changed, and accordingly, the spring characteristics of the elastic body are changed. It is possible to adjust.

  In the present invention, in the internal cylinder type vibration-proof bushing, both of the two directions orthogonal to each other can have low spring characteristics, and the position-shift does not occur in the assembled state to the mating part. Can be provided.

The perspective view of the vibration proof bushing concerning the Example of this invention (A) is a cross-sectional view in the direction perpendicular to the axis showing the state where the vibration isolating bushing is assembled to the counterpart part, and (B) is the direction perpendicular to the axis showing the state where the vibration isolating bush is assembled to the other part different from (A). Cross section of Explanatory drawing of anti-vibration bush according to conventional example

The present invention includes the following embodiments.
(A) A method that has different characteristics of a low spring in both the X direction (one direction perpendicular to the axis) and the Y direction (direction perpendicular to the one direction), and does not cause misalignment when assembled to the mating part. As an example, the inner periphery of the mating part has a rectangular shape, and the rubber shape has a cross shape in which protrusions having different lengths are provided in four directions in the X direction and the Y direction.
(B) The positional deviation is restricted by combining and assembling the protrusion shape of the rubber and each apex of the inner periphery of the mating part, resulting in a low spring having a compression + shear component in both the X direction and the Y direction, and having different characteristics.
(C) Also, rib-shaped rubber is provided between the rubber protrusions in the four directions. When a high load is generated, the rib-shaped rubber functions as a stopper by a spring of a compression component, and restricts displacement above a certain level.
(D) By making the counterpart part into a rectangular shape, the characteristics in the XY directions can be adjusted by the lengths in the long and short directions. The characteristic adjustment by the spring ratio of the compression component and the shear component is also possible by the installation angle of the protrusion shape.
(E) Further, since the sizes are different in the X direction and the Y direction, the assembling direction is clear, and easy positioning is possible in the assembling process.
(F) In the automobile mount bush, the rubber shape is changed to a cross shape having different lengths in the X direction and the Y direction, thereby reducing the spring constant and having different characteristics in the XY direction.
(G) Also, a rib-shaped rubber provided between the protrusions controls displacement by a stopper function when a high load is generated.
(H) The protrusion-shaped rubber provided in the four directions makes the spring a compression + shear component and reduces the spring, and the characteristics in the XY directions can be adjusted by the length and angle of the protrusions in the X and Y directions.
(I) Further, the rib shape provided between the protrusions enables displacement control when a high load is generated.
(J) Since the size differs in the X direction and the Y direction in the assembly process to the actual machine, easy positioning is possible.

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

  The anti-vibration bush 11 according to this embodiment is an inner cylinder type anti-vibration bush provided with a rubber-like elastic body 31 on the outer peripheral side of the inner cylinder 21, as shown in FIG. As shown in FIG. 3, the inner surface 42 of the mating part 41 such as a housing disposed on the outer peripheral side of the elastic body 31 is assembled non-adheringly. Hereinafter, this assembled state will be described.

The mating part 41 is formed into a cylindrical shape by a rigid material such as metal, and includes a cylindrical inner surface part 42. The cylindrical inner surface part 42 has a rectangular shape as shown in a cross-sectional shape perpendicular to the axis. The horizontal side (long side) 42a is a horizontally long rectangle having a length L ₁ and the length of the vertical side (short side) 42b is L ₂ (L ₁ > L ₂ ).

The elastic body 31 is formed into a cylindrical shape by a predetermined rubber-like elastic body, is integrally formed (vulcanized and bonded) to the inner cylinder 21, has an outer peripheral surface 32, and has a cross-sectional shape perpendicular to the axis of the outer peripheral surface 32. As shown in the figure, the shape is a quadrangle, and more specifically, the length of the horizontal side (long side) 32a is L ₃ and the length of the vertical side (short side) 32b is L ₄ which is slightly smaller than the cylindrical inner surface portion 42. there is a horizontally long rectangle and _{(L 3> L 4, L} 1> L 3, L 2> L 4).

The elastic body 31 is assembled with the cylindrical inner surface portion 42 of the counterpart part 41 aligned in a rectangular cross section, that is, the horizontal side 42a of the cylindrical inner surface portion 42, the horizontal side 32a of the outer peripheral surface 32 of the elastic body 31, and the cylindrical shape. The vertical side 42b of the inner surface part 42 and the vertical side 32b of the outer peripheral surface 32 of the elastic body 31 are parallel to each other, so that a cylindrical inner surface is formed around the outer peripheral surface 32 of the elastic body 31 in four directions (up, down, left and right). The gaps c ₁ and c ₂ between the unit 42 are set.

  A protrusion shape (protrusion portion) 33 is integrally provided at each corner of the outer peripheral surface 32 of the elastic body 31, and each protrusion shape 33 is assembled to the inner corner portion 43 of the cylindrical inner surface portion 42 with its tip portion. Yes. The protruding shapes 33 protrude from the corners of the outer peripheral surface 32 of the elastic body 31 in an oblique direction, and are in contact with both the horizontal side 42 a and the vertical side 42 b of the cylindrical inner surface portion 42. Since the four protrusion shapes 33 are provided at the four corners of the rectangular cross section, the four protrusion shapes 33 are provided in an X shape (cross shape) in view of their arrangement and orientation.

  Further, a rib-like rubber stopper 34 faces the horizontal side 42a or the vertical side 42b of the cylindrical inner surface 42 between the protrusion shapes 33 adjacent to each other on each of the four sides (upper and lower left and right) of the outer peripheral surface 32 of the elastic body 31. It is provided as follows. Moreover, as shown in FIG. 1, the flange part 35 is provided in the axial direction both ends of the elastic body 31, respectively.

In the anti-vibration bush 11 having the above-described configuration, the inner corners of the cylindrical inner surface 42 of the counterpart component 41 in which the protrusions 33 provided on the corners of the outer peripheral surface 32 of the elastic body 31 having a rectangular cross section are also rectangular in cross section. The anti-vibration bush 11 is attached to the counterpart part 41 by being assembled to 43, and in this attached state, the rake portions 12 with the gaps c ₁ and c ₂ are set around the elastic body 31 in four directions, respectively. Yes. Further, since the protrusion shape 33 is provided in an oblique direction and has a spring characteristic of a compression + shear component, a lower spring is realized as compared with a spring characteristic of only the compression component. Therefore, both of the horizontal side direction (X direction) and the vertical side direction (Y direction) in the quadrangular cross-section have low spring characteristics.

  The contact angle at which the protrusion 33 contacts the lateral side 42a of the cylindrical inner surface portion 42 and the contact angle at which the projection shape 33 contacts the vertical side 42b of the cylindrical inner surface portion 42 are generally different from each other. It is assumed. Therefore, in this case, the spring constant or the spring characteristic is set to be different between the horizontal side direction (X direction) and the vertical side direction (Y direction).

  Further, in the anti-vibration bush 11 having the above-described configuration, the cross-sectional rectangles are combined, and the protrusion shapes 33 provided at the four corners of the inner rectangle are assembled to the inner corner portions 43 provided at the four corners of the outer rectangle. The protrusion shape 33 is in a state of being prevented from rotating while being non-adhered to the counterpart component 41. Therefore, it is possible to prevent the vibration isolating bush 11 from being displaced in the rotational direction in the assembled state with the counterpart component 41.

  Further, in the anti-vibration bush 11 having the above-described configuration, the cross-sectional rectangles are combined, and the protrusion shapes 33 provided at the four corners of the inner rectangle are assembled to the inner corner portions 43 provided at the four corners of the outer rectangle. The protrusion 33 has an oblique orientation and is assembled with an angle with respect to the inner corner 43, so that the length or length ratio of the lateral side 42a and the longitudinal side 42b of the outer rectangle (tubular inner surface 42) is increased. When changed, the assembly angle is changed, and accordingly, the spring characteristics in the horizontal direction (X direction) and the vertical direction (Y direction) are changed.

For example, in the second example shown in FIG. 2B, the length L _{5 of the} horizontal side (long side) 42a is reduced (L ₁ > L ₅ ) compared to the first example in FIG. , vertical side since the length _{L 6} of the (short side) 42b is enlarged _(L 2 _<L 6), in this case, the contact angle of projecting shapes 33 are brought into contact with the horizontal side 42a of the cylindrical inner surface 42 The contact angle at which the protruding shape 33 comes into contact with the vertical side 42b of the cylindrical inner surface portion 42 becomes smaller. Accordingly, since the shear component increases in the lateral direction (X direction), the spring constant decreases, and in the longitudinal direction (Y direction), the compression component increases, and the spring constant increases.

  Accordingly, by changing the length or length ratio of the horizontal side (long side) 42a and the vertical side (short side) 42b of the rectangular cross section (cylindrical inner surface portion 42) in this way, the cylindrical inner surface portion 42 is changed. By changing the assembly angle of the projection shape 33 with respect to the inner corner portion 43, the spring characteristics of the elastic body 31 can be adjusted accordingly.

  In addition, in the anti-vibration bush 11 having the above-described configuration, the rubber stopper 34 is provided on the outer peripheral surface 32 of the elastic body 31. Therefore, when the high load load is input, the rubber stopper 34 is By contacting the horizontal side (long side) 42 a or the vertical side (short side) 42 b of the cylindrical inner surface portion 42, a certain displacement or more is regulated. Therefore, it is possible to prevent the elastic body 31 from being damaged due to an excessive load applied to the elastic body 31.

DESCRIPTION OF SYMBOLS 11 Anti-vibration bush 12 Straight part 21 Inner cylinder 31 Elastic body 32 Outer peripheral surface 32a, 42a Horizontal side (long side)
32b, 42b Vertical side (short side)
33 Projection shape 34 Rubber stopper part 35 Flange part 41 Counterpart 42 Cylindrical inner surface part 43 Inner surface corner part

Claims (2)

An anti-vibration bush provided with a rubber-like elastic body on the outer peripheral side of the inner cylinder, wherein the anti-vibration bush is assembled to the cylindrical inner surface portion of the mating part disposed on the outer peripheral side of the elastic body.
Each of the cylindrical inner surface part and the axially perpendicular sectional shape of the outer peripheral surface of the elastic body is a quadrangle,
A gap is set between the cylindrical inner surface portion around the outer peripheral surface of the elastic body,
Protrusions are provided at the corners of the outer peripheral surface of the elastic body,
An anti-vibration bush having a structure in which the protruding shape is assembled to an inner corner of the cylindrical inner surface. The anti-vibration bush according to claim 1,
By changing the length or length ratio of the horizontal side and the vertical side in the quadrangle, the assembly angle of the protrusion shape with respect to the inner corner of the cylindrical inner surface is changed, and thereby the spring characteristic of the elastic body is changed. An anti-vibration bush having a structure to adjust.

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