Anti-vibration bushing

Abstract

To provide a vibration-proof bush for actualizing an input load while suppressing increases in the cost and size.SOLUTION: A vibration-proof bush 1 includes an inner cylinder 11 connected to one of a vibration generation part and a vibration receiving part and an outer cylinder 12 connected to the other and encircling the inner cylinder from the radial outside, a body rubber 13 elastically connecting the inner cylinder and the outer cylinder, and a plurality of intermediate members 14 provided at peripheral spaces between the outer peripheral face of the inner cylinder and the inner peripheral face of the outer cylinder, the outer cylinder and the intermediate member including respective conductors 15 formed of conductive materials and joined to the outer cylinder and the intermediate member, and a measurement part 16 for applying AC voltage between the outer cylinder and the intermediate member via the conductors and calculating an input load applied to the vibration-proof bush on the basis of a current flowing between the outer cylinder and the intermediate member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration-isolating bushing. [Background technology]

[0002] Conventionally, a vibration-damping bush has been known that includes an inner tube connected to either a vibration generating part or a vibration receiving part, an outer tube connected to the other and surrounding the inner tube from the outside in the radial direction, and a main body rubber that elastically connects the inner tube and the outer tube, and has a configuration in which a sensor that measures data to obtain an input load is embedded in the outer tube, as shown in Patent Document 1 below, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-270832 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional vibration-isolating bushings, since the sensor is embedded in the outer cylinder, it is difficult to reduce costs and bulk.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a vibration-isolating bushing that can obtain an input load while suppressing costs and bulk. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the above object, the vibration-damping bushing of the present invention comprises an inner tube connected to either the vibration generating part or the vibration receiving part, and an outer tube connected to the other and surrounding the inner tube from the outside in the radial direction, a main body rubber that elastically connects the inner tube and the outer tube, and a plurality of intermediate members spaced circumferentially between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, the outer tube and the intermediate members being formed of a conductive material, and comprising a conductor joined to the outer tube and the intermediate members, and a measuring unit that applies an AC voltage between the outer tube and the intermediate members via the conductor, and calculates the input load applied to the vibration-damping bushing based on the current flowing between the outer tube and the intermediate members.

[0007] According to this invention, a measuring unit is provided that applies an AC voltage between the outer tube and the intermediate member via a conductor joined to the outer tube and the intermediate member, and calculates the input load applied to the vibration-proof bushing based on the current flowing between the outer tube and the intermediate member. As a result, there is no need to attach a sensor to the outer tube and intermediate member; it is sufficient to simply join the conductors to the outer tube and intermediate member, making it possible to obtain the input load while minimizing the complexity of the structure, and reducing the cost and bulk of the vibration-proof bushing.

[0008] The measurement unit may calculate a capacitance between the outer tube and the intermediate member based on a current flowing between the outer tube and the intermediate member, and calculate the input load based on this capacitance.

[0009] Since the measuring unit calculates the input load applied to the vibration-proof bushing based on the electrostatic capacitance between the outer tube and the intermediate member, the input load applied to the vibration-proof bushing can be easily obtained regardless of, for example, the material of the main body rubber.

[0010] The intermediate member may be formed in an arc shape and may be arranged coaxially with the outer cylinder, radially outward from a radial center portion between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder.

[0011] Since the intermediate member is provided radially outward from the radial center between the outer circumferential surface of the inner cylinder and the inner circumferential surface of the outer cylinder, a wide outer circumferential surface area of ​​the intermediate member formed in an arc shape can be ensured. This makes it possible to greatly vary the capacitance between the outer cylinder and the intermediate member in accordance with the relative displacement of the outer cylinder and the intermediate member, and therefore makes it possible to accurately calculate the input load applied to the vibration-proof bushing.

[0012] The intermediate members may be provided on both sides of the inner cylinder in a radial direction, and the conducting wires may be joined to the pair of intermediate members, respectively.

[0013] The input load applied to this vibration-proof bushing is calculated based on the currents flowing separately between the outer tube and the pair of intermediate members, so that the radial input load applied to the vibration-proof bushing can be calculated with high accuracy.

[0014] The intermediate members may be provided in a plurality at intervals in an axial direction along the central axis of each of the inner cylinder and the outer cylinder, and the conducting wires may be joined to each of these intermediate members.

[0015] Since a plurality of intermediate members are provided spaced apart in the axial direction and each of the intermediate members has a conducting wire joined thereto, it is possible to accurately calculate the input load in the prying direction in which the inner tube and the outer tube are displaced relative to each other so that their respective central axes intersect with each other. Effect of the Invention

[0016] According to the present invention, it is possible to obtain an input load while suppressing costs and bulk. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a plan view of the vibration-isolating bush shown as the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Diagram 3]FIG. 11 is a plan view of a vibration-isolating bushing shown as a second embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A first embodiment of the vibration-isolating bushing will now be described with reference to FIGS. The vibration-damping bush 1 comprises an inner tube 11 connected to either the vibration generating part or the vibration receiving part, an outer tube 12 connected to the other and surrounding the inner tube 11 from the outside in the radial direction, a main body rubber 13 elastically connecting the inner tube 11 and the outer tube 12, and a plurality of intermediate members 14 spaced circumferentially between the outer peripheral surface of the inner tube 11 and the inner peripheral surface of the outer tube 12.

[0019] The vibration-isolating bushing 1 is used, for example, as a suspension bushing or engine mount for an automobile, or as a mount for industrial machinery installed in a factory. When the vibration-damping bush 1 is used, for example, as a suspension bush for an automobile, the inner tube 11 is clamped on both axial sides by a bracket (not shown) of a suspension member or the like, and the inner tube 11 is fixed to the bracket using a fastening member (not shown) such as a bolt inserted into the inner tube 11, and the outer tube 12 is fixed to the holder by pressing the outer tube 12 into the inside of, for example, an attachment holder (not shown) of a link member.

[0020] Hereinafter, the direction along the central axis O of the inner cylinder 11 will be referred to as the axial direction. In addition, in a plan view of the vibration-proof bushing 1 from the axial direction, the direction intersecting the central axis O will be referred to as the radial direction, and the direction going around the central axis O will be referred to as the circumferential direction.

[0021] The axial center portions of the inner tube 11, outer tube 12, intermediate member 14, and main rubber 13 coincide with one another. The vibration-proof bushing 1 has a symmetrical shape with respect to a straight line L passing through the axial center portion in a vertical cross-sectional view along one of the axial and radial directions. The outer cylinder 12 is formed of a conductive material such as a metal material or a conductive polymer material. The outer cylinder 12 is disposed coaxially with the central axis O. Both axial ends of the inner cylinder 11 are located axially outward of both axial ends of the outer cylinder 12 . The main body rubber 13 connects the outer circumferential surface of the intermediate member 14 to the inner circumferential surface of the outer tube 12 , and also connects the inner circumferential surface of the intermediate member 14 to the outer circumferential surface of the inner tube 11 .

[0022] The intermediate member 14 is formed of a conductive material similar to the outer tube 12. Both axial ends of the intermediate member 14 protrude outward in the axial direction from the main rubber 13. Both axial ends of the intermediate member 14 are located axially inward relative to both axial ends of the outer tube 12. The intermediate members 14 are provided separately on both sides of the inner tube 11 that sandwich the inner tube 11 in the radial direction. These intermediate members 14 are formed to be the same size and shape. The intermediate members 14 are formed in an arc shape centered on the central axis O.

[0023] The intermediate member 14 is provided radially outward from the radial center between the outer peripheral surface of the inner cylinder 11 and the inner peripheral surface of the outer cylinder 12. The radial distance between the outer peripheral surface of the intermediate member 14 and the inner peripheral surface of the outer cylinder 12 is smaller than the radial distance between the inner peripheral surface of the intermediate member 14 and the outer peripheral surface of the inner cylinder 11.

[0024] In this embodiment, the vibration-isolating bushing 1 includes a conducting wire 15 and a measuring portion 16. The conducting wire 15 is directly joined to the outer tube 12 and the intermediate member 14 by, for example, welding or brazing. The conducting wire 15 is joined to each of a pair of intermediate members 14 provided on both sides of the inner tube 11 in the radial direction. The measurement unit 16 includes an oscillator 17, a detector 18, and a calculator 19. The measurement unit 16 applies an AC voltage between the outer tube 12 and the intermediate member 14 via the conductor 15, and calculates the input load applied to the vibration-proof bushing 1 based on the current flowing between the outer tube 12 and the intermediate member 14.

[0025] In this embodiment, the measuring unit 16 calculates the capacitance between the outer tube 12 and the intermediate member 14 based on the current flowing between them, and calculates the input load based on this capacitance. When the radial distance between the inner peripheral surface of the outer tube 12 and the outer peripheral surface of the intermediate member 14 becomes smaller, the capacitance increases, and when the distance becomes larger, the capacitance decreases.

[0026] The oscillator 17 applies an AC voltage between the outer cylinder 12 and the intermediate member 14 via the conductor 15 . The detection unit 18 detects the current flowing between the outer tube 12 and the intermediate member 14, and calculates the electrostatic capacitance between the outer tube 12 and the intermediate member 14 based on this current. The calculation unit 19 calculates the distance based on the capacitance calculated by the detection unit 18 and a pre-stored relational equation between the capacitance and the radial distance between the inner surface of the outer tube 12 and the outer surface of the intermediate member 14, calculates the difference between the obtained distance and the pre-stored distance before the load input, i.e., the relative displacement amount of the outer tube 12 and the intermediate member 14, and calculates the input load applied to the vibration-damping bushing 1 based on this difference and the pre-stored Young's modulus of the main rubber 13, etc.

[0027] In addition, the calculation unit 19 may calculate the difference between the capacitance calculated by the detection unit 18 and the capacitance before the load input that has been stored in advance, and calculate the relative displacement amount based on this difference and a relational equation between the capacitance difference and the relative displacement amount of the outer tube 12 and the intermediate member 14 that has been stored in advance, and calculate the input load applied to the vibration-damping bushing 1 based on the obtained relative displacement amount and the Young's modulus of the main rubber 13 that has been stored in advance, etc.

[0028] As described above, according to the vibration-damping bushing 1 of this embodiment, since it is equipped with a measuring section 16, there is no need to attach a sensor to the outer tube 12 and the intermediate member 14; it is sufficient to simply join the conductive wire 15 directly to the outer tube 12 and the intermediate member 14. This makes it possible to obtain the input load while minimizing the complexity of the structure, and reduces the cost and bulk of the vibration-damping bushing 1.

[0029] Since the measuring unit 16 calculates the input load applied to the vibration-damping bushing 1 based on the electrostatic capacitance between the outer tube 12 and the intermediate member 14, the input load applied to the vibration-damping bushing 1 can be easily obtained without depending on, for example, the material of the main body rubber 13.

[0030] Since the intermediate member 14 is provided radially outward from the radial center between the outer circumferential surface of the inner cylinder 11 and the inner circumferential surface of the outer cylinder 12, it is possible to ensure a wide area of ​​the outer circumferential surface of the intermediate member 14, which is formed in an arc shape. This makes it possible to greatly vary the capacitance between the outer cylinder 12 and the intermediate member 14 in accordance with the relative displacement of the outer cylinder 12 and the intermediate member 14, and therefore the input load applied to the vibration-proof bushing 1 can be calculated with high accuracy.

[0031] The input load applied to this vibration-proof bushing 1 is calculated based on the currents flowing separately between the outer tube 12 and the pair of intermediate members 14, so that the radial input load applied to the vibration-proof bushing 1 can be calculated with high accuracy.

[0032] Next, a vibration-isolating bushing 2 according to a second embodiment will be described with reference to FIGS. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being described.

[0033] In this embodiment, a pair of intermediate members 14 are provided at positions spaced 90° apart from each other around the central axis O. Conductive wires 15 are joined to all four intermediate members 14. This makes it possible to accurately calculate the input loads in two directions perpendicular to each other as viewed from the axial direction. Furthermore, a plurality of intermediate members 14 are provided at intervals in the axial direction, and each of these intermediate members 14 is also joined to a conductor wire 15 separately.

[0034] In the illustrated example, the multiple intermediate members 14 are formed to be the same size and shape. The circumferential positions of intermediate members 14 adjacent to each other in the axial direction coincide with each other. The axial positions of intermediate members 14 facing each other in the radial direction coincide with each other. The vibration-proof bushing 2 has a symmetrical shape with respect to a straight line L passing through the center in the axial direction when viewed in a vertical cross section along one of the axial and radial directions.

[0035] As described above, according to the vibration-damping bush 2 of this embodiment, a plurality of intermediate members 14 are provided at intervals in the axial direction, and each of the intermediate members 14 has a conducting wire 15 joined thereto separately, so that the input load in the prying direction in which the inner tube 11 and the outer tube 12 are displaced relative to each other so that their respective central axes intersect with each other can be accurately calculated.

[0036] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0037] For example, in the above embodiment, the measuring unit 16 calculates the capacitance between the outer tube 12 and the intermediate member 14 based on the current flowing between them, and calculates the input load applied to the vibration-damping bushing 1 based on this capacitance, but this is not limited to the above, and it is also possible to calculate the electrical resistance between the outer tube 12 and the intermediate member 14 based on the above-mentioned current, and calculate the input load based on this electrical resistance.

[0038] The conducting wire 15 may be joined to only one of a pair of intermediate members 14 provided separately on both sides of the inner cylinder 11 in the radial direction. In the second embodiment, the conductive wire 15 may be joined to only one of the multiple intermediate members 14 spaced apart in the axial direction. The intermediate member 14 may be provided at the radial center between the outer circumferential surface of the inner cylinder 11 and the inner circumferential surface of the outer cylinder 12, or radially inward from this position.

[0039] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate. [Explanation of symbols]

[0040] 1, 2 Anti-vibration bushing 11 Inner cylinder 12 Outer cylinder 13 Body rubber 14 Intermediate parts 15 Conductor 16 Measurement section O center axis

Claims

1. an inner cylinder connected to one of the vibration generating unit and the vibration receiving unit, and an outer cylinder connected to the other and surrounding the inner cylinder from the outside in the radial direction; a main body rubber that elastically connects the inner cylinder and the outer cylinder; A vibration-isolating bushing comprising: a plurality of intermediate members provided at intervals in a circumferential direction between an outer circumferential surface of the inner cylinder and an inner circumferential surface of the outer cylinder; the outer cylinder and the intermediate member are formed of a conductive material; A conducting wire joined to the outer cylinder and the intermediate member; a measuring unit that applies an AC voltage between the outer tube and the intermediate member via the conductor and calculates an input load applied to the vibration-isolating bushing based on the current flowing between the outer tube and the intermediate member.

2. 2. The vibration-damping bushing according to claim 1, wherein the measurement unit calculates a capacitance between the outer tube and the intermediate member based on a current flowing between the outer tube and the intermediate member, and calculates the input load based on this capacitance.

3. The vibration-damping bushing of claim 2, wherein the intermediate member is formed in an arc shape and is arranged coaxially with the outer cylinder, radially outward from the radial center between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder.

4. 4. The vibration-isolating bushing according to claim 1, wherein the intermediate members are provided on both sides of the inner cylinder in a radial direction, and the conducting wires are joined to the pair of intermediate members, respectively.

5. The vibration-damping bushing according to any one of claims 1 to 4, wherein the intermediate members are provided at intervals in the axial direction along the central axes of the inner tube and the outer tube, and the conductive wires are each joined to each of these intermediate members.

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