Mounting structure of a vibration isolation bushing

Abstract

This utility model discloses an installation structure for a vibration damping bushing, the purpose of which is to eliminate the torsion of the vibration damping rubber and the resulting reaction force. In the vibration damping bushing, vibration damping rubber is provided on the outer periphery of a cylindrical component, and a circular plate-shaped collar portion is provided at one end of the cylindrical component. The vibration damping bushing is installed on a support component and a fixed object by fitting the vibration damping rubber into a through hole formed in a support component and screwing a bolt inserted into a bolt insertion hole onto a fixed object supported by the support component. The cylindrical component is fitted with the support component with the collar portion pressed against the fixed object. The bolt is inserted into the bolt insertion hole from the end opposite to the collar portion and screwed onto the fixed object. An anti-dislodgement component larger than the opening diameter of the through hole is fixed to the outer periphery of the end, and this end protrudes from the vibration damping rubber on the side of the cylindrical component opposite to the collar portion.

Description

Technical Field

[0001] This utility model relates to a structure for supporting specified equipment by means of a vibration damping bushing, and more particularly to a structure for installing the vibration damping bushing on a support component such as a bracket. Background Technology

[0002] Patent Document 1 describes an example of a structure using a vibration-damping bushing to support an on-board unit. The structure described in Patent Document 1 is a structure that supports an inverter on a transmission drive axle. A plate-shaped bracket is mounted on the transmission drive axle, and a vibration-damping bushing is embedded in the front end portion of the bracket. Bolts passing through the vibration-damping bushing are screwed onto the inverter. Therefore, the inverter is supported by the vibration-damping bushing mounted on the bracket via bolts integral with it.

[0003] The vibration damping bushing is configured to hold vibration damping rubber between an inner sleeve and an outer sleeve arranged concentrically relative to the inner sleeve. Each sleeve has a flange-like portion, i.e., a collar, extending outward in the radial direction at one end in the axial direction. Vibration damping rubber is also filled between these collars to provide axial cushioning. Therefore, the so-called front end of the vibration damping bushing, opposite to the end with the collar, is inserted into the through hole formed in the bracket, facing the inverter. In this state, a bolt is inserted into the interior of the inner sleeve, and its front end is screwed onto the inverter, thereby fixing the vibration damping bushing to the inverter.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2015-197194 Utility Model Content When bolts are tightened to secure the vibration damping bushing to the inverter and bracket, the vibration damping rubber is compressed between the collars and undergoes elastic deformation, resulting in a state of internal stress filling the space between the inner and outer sleeves. This reaction force acts in the direction that pushes the bolt back, thus generating friction between the bolt head and the inner sleeve collar. This friction acts in the opposite direction to the bolt tightening. Furthermore, the inner sleeve, due to the friction with the bolt, tends to rotate in the bolt's rotational direction, while the outer sleeve is fixed to the bracket, causing the vibration damping rubber to twist. Additionally, friction is generated at the contact point because the front end of the inner sleeve is pressed against the side of the inverter. This friction acts in the direction that prevents the inner sleeve from rotating.

[0005] As described above, in a structure where the anti-vibration bushing is fixed by tightening bolts, the anti-vibration rubber inevitably twists. The torque caused by this twisting acts in the direction of loosening the tightened bolts. In conventional mounting structures known in Patent Document 1, the inner bushing's collar is pressed directly by the bolt head or via a washer, while the outer surface to which the inverter is fixed only abuts the front end of the inner bushing. That is, the frictional force between the inner bushing's collar and the bolt head, acting as a reaction force caused by the twisting of the anti-vibration rubber, is greater than the frictional force acting in the direction of stopping the rotation of the inner bushing between the front end of the inner bushing and the outer surface of the inverter. Therefore, for the bolts after the anti-vibration bushing is installed, the torque caused by the twisting of the anti-vibration rubber continues to act in the direction of loosening the bolts, which may cause the inverter, in which the anti-vibration bushing is located, to become insufficiently or insecurely fixed. Furthermore, the bracket side may rotate due to the torque caused by the twisting of the anti-vibration rubber, resulting in a positional shift.

[0006] This utility model addresses the aforementioned technical issues and aims to provide an installation structure for a vibration damping bushing that can eliminate the torsion of the vibration damping rubber or the resulting reaction force.

[0007] To achieve the above objectives, this utility model provides an installation structure for a vibration damping bushing. The vibration damping bushing includes a vibration damping rubber layer on the outer periphery of a cylindrical component and a circular, outwardly extending ring portion at one end of the cylindrical component. The cylindrical component has a bolt insertion hole at its center. The vibration damping bushing is installed on the support component and the fixed object by fitting the vibration damping rubber layer into a through hole formed in the support component and by screwing a bolt inserted into the bolt insertion hole into a fixed object supported by the support component. The installation structure of the vibration damping bushing is characterized in that the cylindrical component is fitted with the support component while the ring portion is pressed against the fixed object. The bolt is inserted into the bolt insertion hole from the end opposite to the ring portion and screwed into the fixed object. An anti-dislodgement component larger than the opening diameter of the through hole is fixed to the outer periphery of the end portion. The end portion protrudes from the vibration damping rubber layer on the side of the cylindrical component opposite to the ring portion.

[0008] Utility Model Effect According to this invention, the vibration-damping bushing contacts the fixed object through the collar portion and contacts the bolt head or the washer between the bolt head and the cylindrical component at the front end. Therefore, the frictional force generated between the bushing and the fixed component is greater than the frictional force generated between the front end of the cylindrical component and the bolt head. Thus, when the bolt is tightened and the cylindrical component contacts both the fixed object and the bolt head, a torque caused by friction is generated at these locations. However, because the frictional force on the fixed object side is greater than the frictional force on the bolt head side, the cylindrical component will not rotate even if the bolt is rotated. That is, the vibration-damping rubber will not twist, and it can prevent the positional displacement of the support component. Attached Figure Description

[0009] Figure 1 This is a front view showing one embodiment of the present invention.

[0010] Figure 2 This is its sectional view. Detailed Implementation

[0011] Next, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are merely examples of implementing the present invention and do not limit the scope of the invention.

[0012] Figure 1 An embodiment of the present invention is shown in the figure. Figure 2 A cross-sectional view is shown. The example shown here illustrates an application of this invention to a structure for securing a charger housing to a bracket located above a power control unit in an electric vehicle. Figure 1 and Figure 2 In the diagram, the symbol "1" represents a bracket that supports the component, and the symbol "2" represents a charger housing that holds the object in place.

[0013] A through hole 3 is formed at a predetermined location on the bracket 1. A vibration damping bushing 4 is inserted into the through hole 3. The basic structure of the vibration damping bushing 4 is roughly the same as that of conventionally known vibration damping bushings, and it is constructed by filling the space between a metal inner sleeve 5 and an outer sleeve 6 arranged concentrically relative to the inner sleeve 5 with vibration damping rubber 7.

[0014] The inner sleeve 5 corresponds to the cylindrical component in the embodiments of this utility model, such as... Figure 2As shown, the sleeve 6 has a cylindrical portion with a bolt insertion hole 8 formed in the center, and a flange-shaped or disc-shaped collar portion 9 provided at one end of the cylindrical portion extending outward in the radial direction. Furthermore, the outer sleeve 6 has a cylindrical portion with an outer diameter larger than the inner diameter of the cylindrical portion in the inner sleeve 5, and a flange-shaped collar portion 10 provided at one end (the end on the side of the aforementioned collar portion 9) in the axial direction extending outward in the radial direction. The length of the cylindrical portion in the outer sleeve 6 in the axial direction is approximately the same as the length of the through hole 3 formed in the bracket 1, and therefore shorter than the length of the cylindrical portion in the inner sleeve 5. Furthermore, the outer diameters of each collar portion 9 and 10 are approximately the same. Figure 2 In the example shown, the outer diameter of the collar portion 9 in the inner sleeve 5 is slightly smaller than the outer diameter of the collar portion 10 in the outer sleeve 6. Furthermore, anti-vibration rubber 7 is filled between the cylindrical portions of each sleeve 5 and 6, or between each collar portion 9 and 10. In other words, each sleeve 5 and 6 is connected as a single unit by the anti-vibration rubber 7.

[0015] The cylindrical portion of the inner sleeve 5 has a length protruding axially from the through hole 3 when the anti-vibration bushing 4 is inserted into the bracket 1. Furthermore, a plate 11 is provided on the outer periphery of the end of this cylindrical portion opposite to the collar portion 9. The plate 11 corresponds to the anti-detachment component in the embodiment of this utility model, and is made of a metal plate with an outer diameter larger than the inner diameter (opening diameter) of the through hole 3 in the bracket 1. The method for installing the plate 11 into the inner sleeve 5 can be appropriately adopted as needed. Figure 1 and Figure 2 In the example shown, plate 11 is pressed into the front end of the cylindrical portion of inner sleeve 5.

[0016] The installation structure of the anti-vibration bushing in this embodiment of the present invention is characterized in that the anti-vibration bushing 4 is fitted into the through hole 3 of the bracket 1, so that the collar portion 9 in the inner sleeve 5 is located on the side of the housing 2, which is the object to be fixed. In this state, the anti-vibration bushing 4 is fixed to the housing 2 by bolts 12. Specifically, firstly, without the plate 11 installed, the anti-vibration bushing 4 is inserted into the through hole 3 of the bracket 1 from the side of the housing 2. In this state, the plate 11 is pressed into the front end of the cylindrical portion fixed in the inner sleeve 5, and the housing 2 is positioned inside the bracket 1. Furthermore, after the bracket 1 is installed on the housing 2, and the housing 2 is installed on the upper side of the power control unit (not shown), the bracket 1 with the anti-vibration bushing 4 is positioned along the housing 2. In addition, the insertion direction of this anti-vibration bushing 4 relative to the bracket 1 is opposite to the conventional insertion direction.

[0017] With the bolt insertion hole 8 of the inner sleeve 5 aligned with the threaded hole in the housing 2, the collar portion 9 of the inner sleeve 5 is pressed against the side of the housing 2. In this state, the bolt 12 is inserted from the end side of the plate 11 on which the inner sleeve 5 is mounted into the bolt insertion hole 8, and the front end is threaded into the threaded hole of the housing 2. Furthermore, in Figure 2 In the example shown, washer 13 is embedded in bolt 12.

[0018] If the bolt 12 is further threaded, the washer 13 contacts the front end of the cylindrical portion of the inner sleeve 5, pressing the anti-vibration bushing 4 towards the housing 2. Subsequently, the collar portion 9 gradually and strongly presses against the side of the housing 2, generating frictional force between them as the bolt 12 rotates. Similarly, the washer 13 gradually and strongly contacts the front end of the cylindrical portion in the inner sleeve 5, generating frictional force between them as the bolt 12 rotates. In the inner sleeve 5, the contact area relative to the opposing component is larger on the collar portion 9 side and smaller on the front end of the cylindrical portion side. Therefore, the torque acting on the inner sleeve 5 with the rotation of the bolt 12 is less than the resistance acting between the collar portion 9 and the housing 2. Therefore, in the above-described mounting structure, even if the bolt 12 is rotated, the inner sleeve 5 will not rotate, thus preventing the anti-vibration rubber 7 from twisting or generating a reaction force that would cause the bolt 12 to rotate in the loosening direction. Furthermore, positional deviation on the bracket 1 side can be avoided.

[0019] Furthermore, the vibration-damping bushing 4 in this embodiment of the present invention includes the aforementioned plate 11. Therefore, when an external force separates the bracket 1 from the housing 2, the opening end of the through hole 3 in the bracket 1 is engaged with the aforementioned plate 11. Thus, the so-called bushing detachment, which prevents the vibration-damping bushing 4 from falling off the bracket 1, is prevented.

[0020] The above describes one embodiment of the present invention, but the present invention is not limited to the above embodiment and can be implemented by appropriate modifications within the scope of achieving the purpose of the present invention. For example, it may be a vibration-damping bushing without the outer sleeve 6 described above. Furthermore, in addition to the plate described above, the anti-detachment component may also be a component that doubles as a bolt washer.

[0021] Symbol Explanation 1-Bracket, 2-Housing, 3-Through hole, 4-Anti-vibration bushing, 5-Inner sleeve, 6-Outer sleeve, 7-Anti-vibration rubber, 8-Bolt insertion hole, 9, 10-Collar section, 11-Plate, 12-Bolt, 13-Washer.

Claims

1. An installation structure for a vibration damping bushing, wherein a vibration damping rubber is provided on the outer periphery of a cylindrical component, and a circular plate-shaped collar portion extending outward in the radial direction is provided at one end of the cylindrical component; a bolt insertion hole is provided at the center of the cylindrical component; the vibration damping bushing is installed on the support component and the fixed object by fitting the vibration damping rubber into a through hole formed in a support component and by screwing a bolt inserted into the bolt insertion hole into a fixed object supported by the support component; the installation structure of the vibration damping bushing is characterized in that... The cylindrical component engages with the support component while the collar portion is pressed against the fixed object. The bolt is inserted into the bolt insertion hole from the end opposite to the collar portion and engages with the object being fixed. An anti-detachment component larger than the opening diameter of the through hole is fixed to the outer periphery of the end, and the end protrudes from the anti-vibration rubber on the side of the cylindrical component opposite to the collar portion.

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