JP2019163788A - Anti-vibration grommet - Google Patents

Abstract

To make an anti-vibration grommet possess a further remarkable two-stage characteristic between a displacement amount and a reaction force.SOLUTION: An anti-vibration grommet 101 comprises a base body 111 which is attached to a support-side member, for example, a body 201 of an automobile by using an axial hole 112 and an end axial hole 134 along an axial direction, and fits and attaches a supported-side member, for example, a housing 301 of an electric unit to an attachment groove 113 which is formed along a direction orthogonal to the axial direction, and also comprises an initial deflection body 131 at its end portion. The base body 111 has a pair of deflection bodies 114 which are aligned in the axial direction with the attachment groove 113 sandwiched therebetween, and the initial deflection body 131 has a bridge structure with a plurality of leg parts 133 erecting from end faces of the deflection bodies 114 as support legs. The deflection body 114 is deflected in the axial direction, the initial deflection body 131 is elastically deformed in a direction other than the axial direction, and thus, both the bodies play roles of vibration absorption actions. At this time, the initial deflection body 131 is deflected by a force weaker than those of the deflection bodies 114.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an anti-vibration grommet.

  Conventionally, an anti-vibration grommet has been put to practical use that is disposed in a mount portion that attaches a supported member to a supporting member and suppresses transmission of vibration between the two members. Anti-vibration grommets are mounted parts such as compressor units and blowers built into household electrical appliances such as electrical units and small motors, air conditioners and refrigerators mounted on automobiles, and HDD units mounted on office equipment and personal computers. Widely used in

  FIG. 5 is a perspective view showing an example of a conventional anti-vibration grommet in use. In FIG. 5, the supporting member is, for example, the body 2 of the automobile, and the supported member is, for example, the housing 3 of the electrical unit. The vibration isolating grommet 1 </ b> A is fixed to the body 2 by a bolt 4 and supports the housing 3.

  As shown in FIG. 6, the vibration isolating grommet 1 </ b> A has a cylindrical shape that is integrally formed of a rubber-like elastic material, passes through the shaft hole 11 along the axial center, and is attached to the central portion of the outer peripheral surface. A groove 12 is provided. Therefore, a pair of flexures 13 having a flange-like shape in the axial direction is formed across the mounting groove 12.

  As shown in FIG. 5, in order to mount the vibration isolating grommet 1 </ b> A on the mount portion of the housing 3 with respect to the body 2, first, the vibration isolating grommet 1 </ b> A is inserted into the mounting hole 3 a provided in the housing 3. The hole 3a is fitted. Before and after this, the collar 21 is attached to the vibration isolating grommet 1A. The collar 21 is a pipe-like member having a T-shaped cross section, and is used by inserting the pipe 21a into the shaft hole 11 of the vibration isolating grommet 1A. The insertion direction of the collar 21 is a direction in which the flange 21b is directed to the body 2 side.

  Thereafter, the vibration isolating grommet 1A is brought into contact with the body 2 through the flange 21b of the collar 21, and the screw hole 2a provided in the body 2 and the shaft hole 11 of the vibration isolating grommet 1A are aligned. Then, the bolt 4 passed through the washer 22 is inserted into the shaft hole 11, and the screw portion 4a of the bolt 4 is screwed into the screw hole 2a and tightened.

  At this time, the bolt 4 is inserted into the pipe 21 a of the collar 21 inserted into the shaft hole 11, so that it protrudes from the body 2 by a distance corresponding to the length of the collar 21 plus the thickness of the washer 22. This protrusion amount defines the compression amount in the axial direction of the vibration isolating grommet 1A.

  In the vibration isolating grommet 1A having such a structure, when a vibration is generated between the body 2 of the automobile and the housing 3 of the electrical unit, the flexible body 13 bends and absorbs the vibration. Mitigates the transmission of vibration. For example, as shown in FIG. 7, when an input in the direction of the arrow is applied to the body 2 as a traveling automobile sinks, the upper flexible body 13 bends in the axial direction, causing vibration transmitted to the housing 3 of the electrical unit. Absorb.

  An anti-vibration grommet having the same configuration as the anti-vibration grommet 1A introduced above is also described in Patent Document 1, for example.

JP 2014-020427 A JP 2012-138136 A

  The anti-vibration grommet placed in the mount part where the supported member is attached to the supporting member is required to have a role of supporting the supported member with a vibration isolating action and a role of suppressing changes in the behavior of the supported member. It is done. However, in order to enhance the anti-vibration effect, the reaction force generated in the deflecting body 13 must be reduced if the anti-vibration grommet is bent, for example, in the anti-vibration grommet 1A shown in FIGS. In order to increase the action of suppressing the behavior change, it is necessary to increase the reaction force. For this reason, it is difficult to make the two roles compatible.

  Therefore, as a proposal, it is conceivable to reduce the reaction force at the initial stage of compression at the portion where the deflection occurs, and to increase the reaction force after reaching the specified compression amount. An example of the anti-vibration grommet having such characteristics is shown in FIGS. The same or corresponding parts as those of the vibration isolating grommet 1A illustrated in FIGS.

  As shown in FIG. 8, the vibration isolating grommet 1 </ b> B is provided with a plurality of protrusions 31 on both end surfaces of the pair of flexures 13. The portion of the protrusion 31 is easy to bend because it has a smaller volume than the portion of the deflecting body 13.

  Therefore, as shown in FIG. 9, at the initial stage of compression, it bends from the portion of the protrusion 31, and when the protrusion 31 is fully bent, the flexible body 13 bends. For this reason, the anti-vibration grommet 1B exhibits a two-stage characteristic in which the reaction force is low at the initial stage of compression, and the reaction force increases after reaching the specified compression amount.

  An anti-vibration grommet having a similar structure is also described in, for example, Patent Document 2, although there is no explicit description of the two-stage characteristics.

  FIG. 10 is a graph showing the relationship between the displacement of the vibration isolating grommet and the reaction force. In FIG. 10, the alternate long and short dash line indicates the characteristics of the anti-vibration grommet 1 </ b> A illustrated in FIGS. 5 to 7, and the alternate long and two short dashes line indicates the characteristics of the anti-vibration grommet 1 </ b> B illustrated in FIGS. 8 and 9. From the graph of FIG. 10 as well, in the anti-vibration grommet 1A, the displacement and the reaction force are approximately linearly proportional, whereas in the anti-vibration grommet 1B, the reaction force is lower at the initial stage of compression and the specified compression amount is achieved. It can be seen that the reaction force has increased since reaching this point.

  On the other hand, in recent years, a vibration isolating grommet having more remarkable two-stage characteristics has been demanded. For example, the anti-vibration grommet has a characteristic indicated by a solid line in the graph of FIG. However, even with the anti-vibration grommet 1B illustrated in FIG. 8 and FIG. 9, it is difficult to provide a remarkable two-stage characteristic so far.

  An object of the present invention is to provide the vibration-proof grommet with more remarkable two-stage characteristics.

  The present invention includes an axial hole along the axial direction for mounting on a support-side member, a mounting groove provided along a direction orthogonal to the axial direction for mounting and mounting a supported-side member, and an axial direction A base body provided with a pair of flexures formed of an elastic material that flexes and arranged in the axial direction with the mounting groove interposed therebetween, and rises from an end surface of the flexure, and axially with a weaker force than the flexure The above-mentioned problem is solved by providing an initial deflecting body having a bridge structure in which a plurality of leg portions elastically deforming in directions other than the above are used as support legs.

  According to the present invention, since the initial deflecting body having the bridge structure has a high degree of freedom in setting the magnitude of the reaction force with respect to the displacement amount, that is, the flexibility, the flexibility of the deflecting body and the flexibility of the initial deflecting body can be reduced. It is easy to increase the difference between the two, and a more remarkable two-stage characteristic can be provided.

The longitudinal section front view which shows the vibration proof grommet in use condition as one Embodiment. The perspective view of an anti-vibration grommet. The front view of an anti-vibration grommet. The side view of an anti-vibration grommet. The longitudinal section front view which shows the anti-vibration grommet in use condition as an example of the past. FIG. 6 is a perspective view of the vibration isolating grommet shown in FIG. 5. FIG. 6 is a longitudinal front view showing a state when the grommet shown in FIG. 5 is deformed. The perspective view which shows another example of the conventional vibration isolating grommet. FIG. 7 is a longitudinal front view showing a state when the grommet shown in FIG. 6 is deformed. The graph which shows the relationship between the displacement of a vibration isolating grommet, and reaction force.

  An embodiment will be described with reference to FIGS. This embodiment is an example of an anti-vibration grommet used for a mount portion for attaching an electrical unit to an automobile body. The anti-vibration grommet 101 of the present embodiment has a remarkable two-stage characteristic between the amount of displacement and the magnitude of the reaction force.

  FIG. 1 is a longitudinal front view showing an anti-vibration grommet 101 in use. In FIG. 1, the supporting member is an automobile body 201, and the supported member is an electrical unit housing 301.

  However, this is only one example, and the vibration isolating grommet 101 of the present embodiment is, for example, a small motor mounted in an automobile, a compressor, a blower fan, or an office device incorporated in a home appliance such as an air conditioner or a refrigerator. The present invention is applicable to various mount parts in which a supported member is attached to a supporting member, such as an HDD unit mounted on a personal computer or an HDD unit (not shown). What is to be a support-side member and what is to be a support-side member is appropriately determined according to the type of mount portion where the anti-vibration grommet 101 is used.

  As shown in FIG. 1, the anti-vibration grommet 101 includes a base body 111 and an initial deflecting body 131, and is fixed to the body 201 by bolts 151, and supports the housing 301 of the electrical unit at the central portion of the base body 111. ing. The base 111 and the initial deflecting body 131 are integrally formed of a rubber-like elastic material.

  As shown in FIGS. 1 to 4, the base body 111 has a cylindrical shape, passes through a circular shaft hole 112 along the axial center, and is provided with a mounting groove 113 in the center portion of the outer peripheral surface. Therefore, the base 111 has a shape in which a pair of flexures 114 are arranged in the axial direction with the mounting groove 113 interposed therebetween. These flexible bodies 114 have the same shape and the same size as each other, and are arranged vertically so that the central axis coincides with the axis of the base 111.

  As shown in FIGS. 1 to 4, the initial deflecting body 131 has a bridge shape, and is provided on each end face of the base 111. The bridge shape of the initial deflecting body 131 is a shape in which the disk-shaped bridge end 132 is supported by the two leg portions 133. These leg portions 133 are raised from the vicinity of the outer peripheral surface in the end surface of the flexible body 114. Therefore, a clearance C is provided between the flexible body 114 and the bridge end 132.

  The pair of initial deflectors 131 has an end shaft hole 134 in the bridge end 132. These end shaft holes 134 are provided on the axial center of the base 111 and are set to have the same diameter as the shaft holes 112 that penetrate the base 111. Therefore, the anti-vibration grommet 101 passes through the shaft hole 112 and the pair of end shaft holes 134 along the axial center thereof.

  As described above, the vibration isolating grommet 101 is formed by integrally forming the base body 111 and the initial deflecting body 131 with a rubber-like elastic material. For this reason, when receiving a force in the axial direction, the pair of flexible bodies 114 bend in the axial direction due to elastic deformation of the leg portion 133. At this time, the leg 133 is elastically deformed in a direction other than the axial direction, more specifically, in a direction substantially orthogonal to the axial direction until the clearance C disappears. For this reason, compared with the flexible body 114 which has a bulk structure, the initial stage flexible body 131 will bend with a weaker force.

  As shown in FIG. 1, the anti-vibration grommet 101 is attached to the mount portion of the housing 301 with respect to the body 201 with the collar 401 and the washer 402 attached. The collar 401 has a T-shaped cross section having a pipe 401a that can be inserted into the shaft hole 112 of the vibration isolating grommet 101 and into which the threaded portion 151a of the bolt 151 can be inserted, and a flange 401b that is fixed to the end of the pipe 401a. This is a pipe-shaped member. The washer 402 is a flat washer having a hole diameter into which the threaded portion 151 a of the bolt 151 is inserted and abutted against the end surface of the pipe 401 a of the collar 401.

  The anti-vibration grommet 101 is attached to a mount portion of the housing 301 with respect to the body 201 by tightening a bolt 151 in which a screw portion 151 a is screwed into a screw hole 201 a provided in the body 201. At this time, the vibration isolating grommet 101 is attached by being slightly compressed in the axial direction between the flange 401b of the collar 401 and the washer 402. The compression amount of the vibration isolating grommet 101 is determined by the length of the pipe 401 a of the collar 401, that is, the distance between the flange 401 b and the washer 402.

  In order to mount the vibration isolating grommet 101 on the mount portion of the housing 301 with respect to the body 201, first, the vibration isolating grommet 101 is inserted into the mounting hole 301a provided in the housing 301, and the mounting hole 301a is fitted into the mounting groove 113. Before and after this, the collar 401 is attached to the anti-vibration grommet 101. The insertion direction of the collar 401 at this time is a direction in which the flange 401b faces the body 201 side.

  Thereafter, the vibration isolating grommet 101 is brought into contact with the body 201 via the flange 401b of the collar 401, and the screw hole 201a provided in the body 201 and the shaft hole 112 of the vibration isolating grommet 101 are aligned. Then, the bolt 151 passed through the washer 402 is inserted into the shaft hole 112, and the screw portion 151a of the bolt 151 is screwed into the screw hole 201a and tightened.

  In such a configuration, when vibration occurs between the body 201 of the automobile and the housing 301 of the electrical unit, the initial deflecting body 131 and the deflecting body 114 of the vibration isolating grommet 101 bend and absorb the vibration, and the body 201 And vibration transmission between the housing 301 and the housing 301 are reduced. For example, when the body 201 sinks, the body 201 displaces in a direction away from the housing 301, so that the initial deflecting body 131 and the deflecting body 114 located above bend in the axial direction and absorb vibration. . On the other hand, when the body 201 is pushed up, the body 201 is displaced in a direction in which the body 201 approaches the housing 301. Therefore, the initial flexure body 131 and the flexure body 114 positioned below bend in the axial direction to absorb vibration. To do.

  When absorbing such vibration, the initial deflecting body 131 is elastically deformed with a weaker force than the deflecting body 114. Therefore, the initial deflecting body 131 is initially deflected, and when the clearance C is lost, the deflecting body 114 is flexed. Accordingly, the anti-vibration grommet 101 has a two-stage characteristic in which the reaction force is low at the initial stage of compression, and the reaction force becomes high after reaching the specified compression amount.

  In addition, unlike the structure illustrated in FIGS. 8 and 9 in which two types of bulk bodies having different bendability are provided, the initial deflecting body 131 having a bridge structure has a magnitude of reaction force with respect to the displacement amount, that is, High degree of freedom in setting flexibility. For this reason, it is easy to increase the difference between the flexibility of the flexible body 114 and the flexibility of the initial flexible body 131. For example, a more remarkable two-stage characteristic as shown by a solid line in the graph of FIG. It becomes possible to give.

  According to the present embodiment, base 111 and initial deflecting body 131 are integrally formed of a rubber-like elastic material. Therefore, the whole anti-vibration grommet 101 can be manufactured by integral molding, and the manufacturing can be facilitated and the manufacturing time can be shortened. In addition, since the flexible body 114 and the initial flexible body 131 are formed of the same material, the reaction force between them can be appropriately set only by the thickness, shape, etc. of each of these parts, so both are molded of different materials. Compared to the case, the design can be facilitated.

  According to the present embodiment, the initial flexible body 131 is provided on each of the pair of flexible bodies 114. Therefore, when an input is applied to one of the flexures 114 and the other flexure 114, the initial flexure 131 can be initially subjected to the force from any direction.

  According to the present embodiment, the initial deflecting body 131 includes the end shaft hole 134 that shares the axial direction with the shaft hole 112. Therefore, it is easy to make the initial deflecting body 131 symmetrical. By making it symmetrical, the initial deflecting body 131 can be evenly bent in the circumferential direction.

  In implementation, various modifications and changes are allowed.

  For example, in the present embodiment, an example in which the flexible bodies 131 are provided on both end faces of the base body 111 is shown, but this is not essential, and the initial flexible body 131 is provided only on one end face side of the base body 111. It may be. When only one direction is to absorb vibration, it is sufficient to provide the initial deflecting body 131 only on one end face side of the base 111.

  Further, in the present embodiment, an example in which the leg portion 133 that supports the bridge end 132 of the initial flexure body 131 is a biped is shown, but the embodiment is not limited to this, and the leg portion 133 may be a tripod or more. .

  Other variations and modifications are allowed.

1A Anti-vibration grommet 1B Anti-vibration grommet 2 Body 2a Screw hole 3 Housing 3a Mounting hole 4 Bolt 11 Shaft hole 12 Mounting groove 13 Deflector 21 Collar 21a Pipe 21b Flange 22 Washer 31 Protrusion 101 Anti-vibration grommet 111 Base 112 Shaft hole 113 Mounting Groove 114 Deflection body 131 Initial deflection body 132 Bridge end 133 Leg portion 134 End shaft hole 151 Bolt 151a Screw portion 201 Body 201a Screw hole 301 Housing 301a Mounting hole 401 Collar 401a Pipe 401b Flange 402 Washer C Clearance

Claims (4)

An axial hole along the axial direction for attaching to the member on the support side, a mounting groove provided along the direction orthogonal to the axial direction for fitting and attaching the member on the supported side, and elasticity flexing in the axial direction A base provided with a pair of flexures formed of a material and arranged in the axial direction across the mounting groove;
An initial deflecting body having a bridge structure having a plurality of leg portions as support legs that stand up from an end face of the deflecting body and elastically deform in a direction other than the axial direction with a weaker force than the deflecting body;
An anti-vibration grommet characterized by comprising: The base and the initial deflecting body are integrally formed of a rubber-like elastic material.
The anti-vibration grommet according to claim 1. The initial flexures are respectively provided on the pair of flexures,
The anti-vibration grommet according to claim 1 or 2. The initial deflecting body includes an end shaft hole having a common axial direction with the shaft hole.
The anti-vibration grommet according to any one of claims 1 to 3, wherein the anti-vibration grommet is provided.

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