Vibration isolation bushing

Abstract

The present invention provides an anti-vibration bushing capable of inhibiting incomplete fitting of an upper bushing and a lower bushing. The anti-vibration bushing is characterized by including an upper bushing (110) mounted to a vehicle body side, and a lower bushing (120) configured to be fitted to the upper bushing (110), and provided with an interference portion that interferes with each other during fitting of the lower bushing (120) to the upper bushing (110), the interference portion being formed in a fitting sound generating structure that generates a sound when the lower bushing (120) is fitted to the upper bushing (110) at the time of temporary assembly.

Description

TECHNICAL FIELD

[0001] The present application relates to a vibration-proof bushing equipped to a center bearing support. BACKGROUND

[0002] A drive shaft equipped to a vehicle body is equipped with a center bearing support that supports a center bearing thereof. Thereby, transmission of vibration generated in the drive shaft to the vehicle body (a vehicle body of the vehicle body) is suppressed, and noise such as low frequency noise in a vehicle cabin is reduced. In addition, it is also known that in the center bearing support, in order to improve the suppression effect of transmission of vibration from the drive shaft, a vibration-proof bushing is provided to a bracket mounted to the vehicle body side. In such a technique, the bracket is fixed to the vehicle body with the vibration-proof bushing by a bolt, and thereby the center bearing support is mounted to the vehicle body. Here, by providing a hole (a hole into which a shaft portion of the bolt is inserted and penetrated) formed in the bracket as an elongated hole, dimensional errors of various components in the front-rear direction of the vehicle body are absorbed. In such a structure, when various components are mounted to the vehicle body, first, the center bearing support is mounted to the drive shaft, and next, both ends of the drive shaft are mounted to the vehicle body. Then, finally, position adjustment is performed to absorb the dimensional errors, and at the same time, the bracket is mounted to the vehicle body with the vibration-proof bushing by the bolt.

[0003] Here, the vibration-proof bushing includes an upper bushing mounted to the vehicle body side, and a lower bushing provided on the side opposite to the upper bushing with the bracket interposed. In order to finally mount the bracket with the vibration-proof bushing to the vehicle body, a method of screwing and joining by a bolt in a state where the upper bushing is temporarily fixed to the vehicle body side and the lower bushing is disposed to the bracket, thereby assembling the vibration-proof bushing while fixing the bracket to the vehicle body has been adopted in the past. However, due to the dimensions and the like of various components, such a method cannot be adopted at times. Therefore, a method of temporarily fixing the vibration-proof bushing as a whole by fitting the upper bushing and the lower bushing to the bracket in advance has been studied. However, in such a method, in a case where fitting of the upper bushing and the lower bushing is not complete, it is possible that the vibration-proof bushing is detached from the bracket in the work, and workability is reduced.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-132803

[0007] Patent Document 2: Japanese Patent Application Publication No. 2011-131822

[0008] Patent Document 3: Japanese Patent Application Publication No. 2019-19934 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The present application has an object to provide an anti-vibration bushing capable of inhibiting falling due to incomplete fitting when temporarily assembling an upper bush and a lower bush.

[0011] Solution for solving the technical problem

[0012] To solve the above technical problem, the present application adopts the following solution.

[0013] That is, the anti-vibration bushing of the present application is equipped in a center bearing support that supports a center bearing of a propeller shaft,

[0014] The anti-vibration bushing is characterized by comprising:

[0015] an upper bush installed on a vehicle body side; and

[0016] a lower bush configured to be fitted in the upper bush,

[0017] The anti-vibration bushing is provided with interference portions that interfere with each other during fitting of the lower bush in the upper bush, the interference portions form a fitting sound generating structure that generates a sound when the lower bush is fitted in the upper bush at the time of temporary assembly.

[0018] According to the present application, since the interference portions form the fitting sound generating structure, a sound is emitted when the lower bush is fitted in the upper bush at the time of temporary assembly. Thereby, the operator can easily confirm the situation that the upper bush and the lower bush have been fitted. Therefore, the situation that the fitting of the upper bush and the lower bush is incomplete can be inhibited.

[0019] The interference portions can be constituted by protrusions respectively provided to both the upper bush and the lower bush, the protrusions being configured to be deformed by being pressed against each other during fitting of the lower bush in the upper bush at the time of temporary assembly and to return to the original shape thereby generating a sound when the fitting is completed.

[0020] Further, the protrusions constituting the interference portions can be configured such that the protrusion provided to one of the upper bush and the lower bush is constituted by a ring-shaped protrusion, and the protrusion provided to the other is constituted by a plurality of non-ring-shaped protrusions provided at intervals in the circumferential direction.

[0021] In this way, since the protrusion provided to the other of the upper bush and the lower bush is constituted by a plurality of non-ring-shaped protrusions provided at intervals in the circumferential direction, a gap can be formed between adjacent non-ring-shaped protrusions, and sound can be effectively transmitted to the outside.

[0022] Further, the upper bush can have a first inner ring, a first outer ring equipped concentrically with the first inner ring, and a first elastic body provided integrally with the first inner ring and the first outer ring,

[0023] The lower bushing has a second inner ring, a second outer ring provided concentrically with the second inner ring, and a second elastic body provided integrally with the second inner ring and the second outer ring, and

[0024] The anti-vibration bushing is configured to be fitted between the outer peripheral surface of the first elastic body and the inner peripheral surface of the second elastic body, and the annular protrusion is provided on the outer peripheral surface of the first elastic body, and the plurality of non-annular protrusions are provided on the inner peripheral surface of the second elastic body.

[0025] Further, the non-annular protrusions can include a first inclined surface configured to be away from the central axis of the lower bushing as it is away from the upper bushing, and a second inclined surface provided at a position closer to the upper bushing than the first inclined surface and configured to be away from the central axis as it is closer to the upper bushing,

[0026] The inclination angle of the first inclined surface with respect to a plane perpendicular to the central axis is greater than the inclination angle of the second inclined surface with respect to a plane perpendicular to the central axis.

[0027] Inventive Effects

[0028] As described above, according to the present application, it is possible to suppress the falling off due to the incomplete fitting when temporarily assembling the upper bushing and the lower bushing. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is an external view of a center bearing support of an embodiment of the present application.

[0030] Figure 2 is a cross-sectional view showing a state when the anti-vibration bushing of an embodiment of the present application is mounted to a vehicle body.

[0031] Figure 3 is a cross-sectional view showing a state when the anti-vibration bushing of an embodiment of the present application is assembled.

[0032] Figure 4 is a diagram explaining a fitting completion sound generation mechanism of an embodiment of the present application. DETAILED DESCRIPTION

[0033] Hereinafter, referring to the drawings and based on an embodiment, a mode for carrying out the present application will be explained in detail by way of example. Among them, the dimensions, materials, shapes, and relative arrangement of the structural components described in the embodiment are not intended to limit the scope of the present application only to this unless specifically described.

[0034] (Embodiment)

[0035] Reference Figures 1-4 The anti-vibration bushing of an embodiment of the present application will be explained. Figure 1is an external view of the center bearing support of the embodiment of the present application, showing a front view of the center bearing support, and a view in which a portion of the bracket in the center bearing support is enlarged. Figure 2 is a sectional view showing a state in which the anti-vibration bushing of the embodiment of the present application is attached to a vehicle body. Figure 3 is a sectional view showing a state in which the anti-vibration bushing of the embodiment of the present application is assembled. Note that, in Figure 3 , a sectional view of the anti-vibration bushing as a whole is shown. Figure 1 , a sectional view of a portion thereof (a portion surrounded by an ellipse) is also shown. Figure 4 is a view explaining the fitting completion sound generation mechanism of the embodiment of the present application. Note that, the anti-vibration bushing is a substantially rotationally symmetrical shape, and in Figures 2-4 , a sectional surface obtained by cutting various members with a plane containing the center axis of the anti-vibration bushing is schematically shown.

[0036] <Installation of center bearing support to vehicle body side>

[0037] Referring to Figure 1 and Figure 2 , the manner in which the center bearing support 10 of the present embodiment is attached to the vehicle body side (the vehicle body of the vehicle body) will be explained. In Figure 1 , a portion of the bracket 12 before the anti-vibration bushing 100 is attached is shown enlarged by a circle. As shown in this figure, a long hole 12a is provided in the bracket 12. In this way, by the hole formed in the bracket 12 being constituted by the long hole 12a, dimensional errors of various members in the front-rear direction of the vehicle body can be absorbed. That is, when various members are attached to the vehicle body, the center bearing support 10 (the center bearing support main body 11) is attached to the drive shaft (not shown), and next, both ends of the drive shaft are attached to the vehicle body. Then, finally, position adjustment is performed to absorb dimensional errors, and at the same time, the bracket 12 is attached to the vehicle body side 20 together with the anti-vibration bushing 100 using a bolt. Note that, in Figure 2 , a case in which a structure is adopted in which the anti-vibration bushing 100 and the bracket 12 are attached to the vehicle body side 20 by fastening the shaft portion 30 (external thread) of the bolt to the internal thread 21 provided in the vehicle body side 20 is shown. However, a structure in which the anti-vibration bushing 100 and the bracket 12 are attached to the vehicle body side 20 by fastening a nut to an external thread provided in the vehicle body side (for example, a structure in which the bolt is buried in the vehicle body) can also be adopted.

[0038] <Anti-vibration bushing>

[0039] Referring to Figure 2 and Figure 3The structure of the vibration isolation bush 100 of the present embodiment will be described. The vibration isolation bush 100 of the present embodiment includes an upper bush 110 mounted to the vehicle body side, and a lower bush 120 configured to be fitted to the upper bush 110. Note that the lower bush 120 is disposed on the side opposite the upper bush 110 with the bracket 12 interposed. Also, in the vibration isolation bush 100 of the present embodiment, an interference portion is provided that interferes with each other during fitting of the lower bush 120 to the upper bush 110. In addition, the interference portion forms a fitting sound generating structure that generates sound when the lower bush 120 is fitted to the upper bush 110 at the time of temporary assembly. Details of the fitting sound generating structure will be described later.

[0040] The upper bush 110 has a first inner ring 111, a first outer ring 112 provided concentrically with the first inner ring 111, and a first elastic body 113 provided integrally with these first inner ring 111 and first outer ring 112. The first inner ring 111 is a ring-shaped member composed of a metal or the like, and is composed of a cylindrical portion 111a and an outward flange portion 111b provided at one end of the cylindrical portion 111a. The first inner ring 111 is configured so that the shaft portion 30 of the bolt is inserted and penetrates through the inside of the cylindrical portion 111a. In addition, the outward flange portion 111b is configured to abut against the vehicle body 20 of the vehicle body. The first outer ring 112 is a flat washer-shaped member composed of a metal or the like. By providing the first outer ring 112, the upper bush 110 is stably supported to the bracket 12. Further, the first elastic body 113 is composed of an elastic body such as rubber. The first elastic body 113 includes a ring-shaped portion 113a that functions as a vibration isolation function, and a ring-shaped protrusion 113b provided to the outer circumferential surface of the ring-shaped portion 113a. Note that by insert-molding the first inner ring 111 and the first outer ring 112 as insert members, the upper bush 110 that integrally includes the first inner ring 111, the first outer ring 112, and the first elastic body 113 can be obtained.

[0041] The lower bush 120 has a second inner ring 121, a second outer ring 122 provided concentrically with the second inner ring 121, and a second elastic body 123 integrally provided to the second inner ring 121 and the second outer ring 122. The second inner ring 121 is a flat washer-like member made of metal or the like. The second inner ring 121 is configured to have the shaft portion 30 of the bolt inserted therethrough on the inner side (inner circumferential surface 121a side). The second outer ring 122 is a flat washer-like member made of metal or the like. The lower bush 120 is stably supported to the bracket 12 by providing the second outer ring 122. Further, the second elastic body 123 is made of an elastic body such as rubber. The second elastic body 123 includes a ring-like portion 123a that functions as a vibration-proof portion, and a plurality of non-ring-like protrusions 123b provided to the inner circumferential surface of the ring-like portion 123a. The plurality of non-ring-like protrusions 123b are provided at intervals in the circumferential direction. Note that, in the present embodiment, four non-ring-like protrusions 123b are provided at equal intervals. By insert-molding the second inner ring 121 and the second outer ring 122 as insert members, the lower bush 120 that integrally includes the second inner ring 121, the second outer ring 122, and the second elastic body 123 can be obtained.

[0042] Further, the vibration-proof bush 100 of the present embodiment is configured to be fitted between the outer circumferential surface of the first elastic body 113 in the upper bush 110 and the inner circumferential surface of the second elastic body 123 in the lower bush 120. As described above, the ring-like protrusion 113b is provided to the outer circumferential surface of the first elastic body 113, and the plurality of non-ring-like protrusions 123b are provided to the inner circumferential surface of the second elastic body 123. These ring-like protrusion 113b provided to the first elastic body 113 and the plurality of non-ring-like protrusions 123b provided to the second elastic body 123 function as interference portions that interfere with each other during fitting of the lower bush 120 to the upper bush 110.

[0043] With respect to this point, detailed description will be made with reference to Figure 4 The ring-like protrusion 113b and the non-ring-like protrusion 123b are deformed by being pressed against each other during fitting of the lower bush 120 to the upper bush 110 at the time of temporary assembly of the lower bush 120. Note that, in Figure 4 (a) of FIG. 11, the ring-like protrusion 113b and the non-ring-like protrusion 123b that are deformed by being pressed against each other are shown by solid lines, and the state before deformation is shown by dotted lines. Further, at the moment when the upper bush 110 and the lower bush 120 are fitted (the moment when the non-ring-like protrusion 123b passes over the ring-like protrusion 113b), the ring-like protrusion 113b and the non-ring-like protrusion 123b both return to the original shape. Here, the ring-like protrusion 113b and the non-ring-like protrusion 123b are configured to generate a sound when they return to the original shape in a manner of being abruptly elastically returned (see (b) of FIG. 11). Figure 4 ​

[0044] Thus, the interference portion formed by the protrusions (annular protrusions 113b and multiple non-annular protrusions 123b) respectively provided on both the upper bushing 110 and the lower bushing 120 forms a fitting sound generating structure that produces sound when the lower bushing 120 is fitted into the upper bushing 110. It should be noted that the size, shape, rigidity (material of the first elastic body 113 and the multiple non-annular protrusions 123b), and number of non-annular protrusions 123b can be appropriately set so that sound is generated when the lower bushing 120 is fitted into the upper bushing 110 during temporary assembly.

[0045] Furthermore, regarding the non-annular protrusion 123b in the lower bushing 120 of this embodiment, it includes a first inclined surface 123b1 and a second inclined surface 123b2 disposed at a position above the bushing 110 than the first inclined surface 123b1. The first inclined surface 123b1 is configured to move away from the central axis of the lower bushing 120 as it moves away from the upper bushing 110. The second inclined surface 123b2 is configured to move away from the central axis of the lower bushing 120 as it moves closer to the upper bushing 110. Moreover, the inclination angle α of the first inclined surface 123b1 relative to the surface perpendicular to the central axis of the lower bushing 120 is larger than the inclination angle β of the second inclined surface 123b2 relative to the surface perpendicular to the aforementioned central axis (see reference). Figure 3 ).

[0046] <Advantages of the vibration-damping bushing in this embodiment>

[0047] According to the vibration damping bushing 100 of this embodiment, since the interference portion forms a fitting sound generating structure, a sound is emitted when the lower bushing 120 is fitted into the upper bushing 110 during temporary assembly. This allows the operator to easily confirm that they are properly fitted. Therefore, incomplete fitting of the upper bushing 110 and the lower bushing 120 can be suppressed. Consequently, during operations such as installing the center bearing support 10 onto the vehicle body, the vibration damping bushing 100 can be prevented from detaching from the bracket 12 of the center bearing support 10. Therefore, workability is improved.

[0048] Furthermore, to generate a mating sound, the protrusions provided on the lower bushing 120 consist of a plurality of non-annular protrusions 123b arranged circumferentially at intervals. Therefore, the gaps formed between adjacent non-annular protrusions 123b allow the sound generated upon completion of the mating to be effectively propagated to the outside. Thus, the operator can more reliably confirm that the upper bushing 110 and the lower bushing 120 have mated.

[0049] Furthermore, as described above, since the inclination angle α of the first inclined surface 123b1 is larger than the inclination angle β of the second inclined surface 123b2, it has the following advantages. Specifically, during the process of fitting the lower bushing 120 into the upper bushing 110, since the non-annular protrusion 123b generates significant resistance when passing the annular protrusion 113b, the lower bushing 120 and the upper bushing 110 can return to their original shape with a strong spring-loaded motion at the moment of fitting. This allows for the generation of a loud sound. Additionally, for example, when using… Figure 3 In a manufacturing method that uses a mold (not shown) that opens vertically to embed and mold the lower bushing 120, the multiple non-annular protrusions 123b become undercut. Therefore, when removing the molded article from the mold, so-called forced demolding is required. However, by setting the tilt angle α and tilt angle β to the relationship described above, forced demolding can be performed without adversely affecting the non-annular protrusions 123b.

[0050] (other)

[0051] In the above embodiments, a structure is shown in which an annular protrusion 113b is provided in the upper bushing 110 and a plurality of non-annular protrusions 123b are provided in the lower bushing 120 at circumferential intervals. However, in this invention, a structure is also included in which a plurality of non-annular protrusions are provided in the upper bushing at circumferential intervals and an annular protrusion is provided in the lower bushing. In such a structure, of course, the same effects as in the above embodiments can be obtained.

[0052] Explanation of reference numerals in the attached figures

[0053] 10. Center bearing support

[0054] 11. Main body of the center bearing support

[0055] 12 brackets

[0056] 12a Long Hole

[0057] 20 Body

[0058] 21 Internal thread

[0059] 30 Shaft section

[0060] 100 vibration damping bushing

[0061] 110 Upper Bushing

[0062] 111 Inner Ring

[0063] 111a Cylindrical section

[0064] 111b Outwardly projecting flange

[0065] 112 First Outer Ring

[0066] 113 First elastic body

[0067] 113a Annular portion

[0068] 113b Annular protrusion

[0069] 120 lower bushing

[0070] 121 Second Inner Ring

[0071] 121a Inner circumferential surface

[0072] 122 Second Outer Ring

[0073] 123a Annular portion

[0074] 123b Non-annular protrusion.

Claims

1. A vibration damping bushing, fitted onto a central bearing support member supporting a central bearing of a drive shaft, characterized in that it comprises: Upper bushing, installed on the side of the vehicle body; as well as The lower bushing is configured to fit into the upper bushing. The upper bushing has a first inner metal ring, a first outer metal ring concentrically arranged with the first inner ring, and a first elastic body integrally formed with the first inner ring and the first outer ring. The lower bushing has a second inner metal ring, a second outer metal ring concentrically arranged with the second inner ring, and a second elastic body integrally formed with the second inner ring and the second outer ring. The vibration damping bushing is provided with an interference portion, which interferes with each other during the process of the lower bushing being fitted into the upper bushing. The interference portion forms a fitting sound generating structure, which generates sound when the lower bushing is fitted into the upper bushing during temporary assembly. The interference portion is composed of protrusions respectively provided on the upper bushing and the lower bushing. Among the protrusions constituting the interference portion, the protrusion of the first elastic body disposed on the upper bushing is composed of annular protrusions, and the protrusion of the second elastic body disposed on the lower bushing is composed of a plurality of non-annular protrusions spaced apart circumferentially. The non-annular protrusion includes: a first inclined surface configured to move away from the central axis of the lower bushing as it moves away from the upper bushing; And a second inclined surface, positioned closer to the upper bushing than the first inclined surface, and configured to move away from the central axis as it approaches the upper bushing. The first inclined surface has a larger inclination angle relative to the surface perpendicular to the central axis than the second inclined surface has a larger inclination angle relative to the surface perpendicular to the central axis.

2. The vibration damping bushing according to claim 1, characterized in that, The protrusions are configured to deform by pressing against each other during the temporary assembly of the lower bushing into the upper bushing, and to return to their original shape when the fitting is complete, thereby producing sound.

3. The vibration damping bushing according to claim 2, characterized in that, The vibration damping bushing is configured to fit between the outer peripheral surface of the first elastic body and the inner peripheral surface of the second elastic body, and the annular protrusion is provided on the outer peripheral surface of the first elastic body, and a plurality of non-annular protrusions are provided on the inner peripheral surface of the second elastic body.

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