Vibration isolation device

Abstract

To secure sealability of a liquid flowing in an orifice passage, while suppressing production cost.SOLUTION: A vibration proof device includes: an inside mounting member 11 connected to one of a vibration generating part and a vibration receiving part; an outer cylinder 12 connected to the other, and for surrounding the inside mounting member; and an elastic body for elastically connecting the inside mounting member and the outer cylinder. The elastic body includes middle elastic bodies disposed individually on both sides sandwiching the inside mounting member in the radial direction. Between the inside mounting member and the outer cylinder, a covering part 17 is disposed for covering a place between the middle elastic bodies adjacent to each other in the circumferential direction from the outside in the radial direction, and for defining liquid chambers 14a, 14b between itself and the inside mounting member. The elastic body includes a pair of end elastic bodies 31 which is arranged with an interval in the axial direction, which is fitted inside the outer cylinder, and which sandwiches the covering member in the axial direction. Between the end elastic body and an end surface 17a facing the axial direction out of the covering member, an orifice passage is provided for communicating the liquid chambers with each other.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vibration isolator.

Background Art

[0002] Conventionally, an inner mounting member connected to either one of a vibration generating part and a vibration receiving part, an outer cylinder connected to the other and surrounding the inner mounting member, and an elastic body elastically connecting the inner mounting member and the outer cylinder are provided. The elastic body includes middle elastic bodies separately disposed on both sides sandwiching the inner mounting member in the radial direction. Between the inner mounting member and the outer cylinder, a covering member is disposed to cover the space between the circumferentially adjacent middle elastic bodies from the outer side in the radial direction and define a liquid chamber with the inner mounting member. An orifice passage communicating the liquid chambers is provided between the covering member and the outer cylinder. A vibration isolator is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in this vibration isolator, in order to ensure the sealing performance of the liquid flowing through the orifice passage, it is necessary to, for example, improve the dimensional accuracy of the covering member or vulcanize and adhere a rubber film to the inner peripheral surface of the outer cylinder. As a result, it may be difficult to ensure the sealing performance of the liquid flowing through the orifice passage while suppressing the manufacturing cost.

[0005] An object of the present invention is to provide a vibration isolator capable of ensuring the sealing performance of the liquid flowing through the orifice passage while suppressing the manufacturing cost.

Means for Solving the Problems

[0006] In order to solve the above problems and achieve such an object, the vibration isolator of the present invention includes an inner mounting member connected to either one of a vibration generating part and a vibration receiving part, an outer cylinder connected to the other and surrounding the inner mounting member, and an elastic body elastically connecting the inner mounting member and the outer cylinder. The elastic body includes middle elastic bodies separately disposed on both sides sandwiching the inner mounting member in a radial direction intersecting the central axis in a plan view seen from an axial direction along the central axis of the outer cylinder. Between the inner mounting member and the outer cylinder, a covering member is disposed to cover between the middle elastic bodies adjacent to each other in a circumferential direction orbiting around the central axis in the plan view from the outer side in the radial direction to define a liquid chamber between the inner mounting member. The elastic body includes a pair of end elastic bodies spaced apart in the axial direction, fitted into the outer cylinder, and sandwiching the covering member in the axial direction. An orifice passage communicating the liquid chambers with each other is provided between the end elastic body and an end face of the covering member facing the axial direction.

[0007] According to the present invention, since the orifice passage communicating the liquid chambers with each other is provided between the end elastic body of the elastic body and the end face of the covering member, by pressing the end elastic body against the end face of the covering member in a state where the end elastic body is fitted into the outer cylinder, the sealing performance of the liquid flowing through the orifice passage can be surely ensured. Thereby, in order to ensure the sealing performance of the liquid flowing through the orifice passage, it is possible to eliminate the need to, for example, improve the dimensional accuracy of the covering member or vulcanize and bond a rubber film for sealing to other members such as the outer cylinder, and the manufacturing cost can be suppressed.

[0008] The covering member includes a first divided body and a second divided body divided into two in the axial direction. The orifice passage may be integrally provided between the end elastic body and the end face of the first divided body, and between the butting surfaces of the first divided body and the second divided body butted against each other in the axial direction.

[0009] The covering member includes a first divided body and a second divided body that are axially bisected, and the orifice passage is integrally provided between the end elastic body and the end face of the first divided body, and between the butting surfaces of the first divided body and the second divided body that butt against each other in the axial direction. Therefore, while reliably ensuring the sealing performance of the liquid flowing through the orifice passage, the length of the orifice passage can be easily ensured.

Advantages of the Invention

[0010] According to this invention, while suppressing the manufacturing cost, the sealing performance of the liquid flowing through the orifice passage can be ensured.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0012] Hereinafter, a first embodiment of the vibration isolator according to the present invention will be described with reference to FIGS. 1 and 2. The vibration isolator 1 of the present embodiment includes an inner mounting member 11 connected to one of the vibration generating part and the vibration receiving part, and an outer cylinder 12 connected to the other and surrounding the inner mounting member 11, and elastic bodies 31 and 32 that elastically connect the inner mounting member 11 and the outer cylinder 12. Note that the vibration isolator 1 is used, for example, as a suspension bush or an engine mount for an automobile, or a mount for industrial machinery installed in a factory. Hereinafter, the direction along the central axis O of the outer cylinder 12 is referred to as the axial direction, the direction intersecting the central axis O in a plan view seen from the axial direction is referred to as the radial direction, and the direction of orbiting around the central axis O is referred to as the circumferential direction.

[0013] The inner mounting member 11 is formed in a cylindrical shape and arranged coaxially with the central axis O. In the illustrated example, the inner mounting member 11 includes a cylindrical core metal part 21 and a resin part 22 fixed to the outer peripheral surface of the core metal part 21. Note that the inner mounting member 11 may be integrally formed as a whole. The resin part 22 includes a middle part 26 provided at an axial intermediate part on the outer peripheral surface of the core metal part 21, and a pair of outer parts 27 extending separately outward in the axial direction from the middle part 26. The outer peripheral surface of the outer part 27 is located radially inward of the outer peripheral surface of the middle part 26.

[0014] The elastic bodies 31 and 32 are formed of a rubber material and vulcanization-bonded to the outer peripheral surface of the inner mounting member 11. The elastic bodies 31 and 32 are arranged at intervals in the axial direction, and include a pair of annular end elastic bodies 31 fitted in the outer cylinder 12, and middle elastic bodies 32 separately arranged on both sides sandwiching the inner mounting member 11 in the radial direction between the end elastic bodies 31.

[0015] The end elastic body 31 includes an end flange part 31a surrounding the outer part 27 from the outside in the radial direction, and an end connecting part 31b connecting the radially inner end part of the end flange part 31a and the outer peripheral surface of the inner mounting member 11.

[0016] The end flange part 31a extends continuously over the entire circumferential length. The end flange part 31a is arranged coaxially with the central axis O. An annular rigid body plate 33 extending in the circumferential direction is provided on the end flange part 31a. The rigid body plate 33 is formed of a hard material such as, for example, a metal material or a synthetic resin material. The rigid body plate 33 is embedded in the end flange part 31a. The end connecting part 31b is formed in a cylindrical shape and extends continuously over the entire circumferential length. The end connecting part 31b extends radially inward as it extends axially inward from the radially inner end part of the end flange part 31a. The end connecting part 31b is connected to the axially outer end part of the middle part 26. The end connecting part 31b is arranged coaxially with the central axis O.

[0017] The pair of middle elastic bodies 32 have the same shape and are formed with the same size. The middle elastic bodies 32 are formed of a rubber material throughout. The axial outer ends of the middle elastic bodies 32 are connected to the end elastic bodies 31.

[0018] On the outer peripheral surface of the inner mounting member 11, stopper elastic parts 34 protruding toward the respective liquid chambers 14a and 14b are provided separately. Note that the stopper elastic parts 34 may not be provided on the outer peripheral surface of the inner mounting member 11. The stopper elastic parts 34 are provided in the middle part 26. The stopper elastic parts 34 are capable of coming into contact with the inner surface of a covering member 17, which will be described later, when the inner mounting member 11 and the outer cylinder 12 move relatively closer. The stopper elastic parts 34 are disposed between the middle elastic bodies 32 adjacent to each other in the circumferential direction and constitute a part of the partition wall between the liquid chambers 14a and 14b. The stopper elastic parts 34 are connected to the middle elastic bodies 32 in the circumferential direction. The stopper elastic parts 34 are connected to the end connecting parts 31b in the axial direction. The stopper elastic parts 34, and the elastic bodies 31 and 32 are integrally formed of, for example, a rubber material or the like. The outer peripheral surface of the inner mounting member 11 is covered with, for example, a rubber material or the like throughout.

[0019] Between the inner mounting member 11 and the outer cylinder 12, a covering member 17 is disposed to cover a portion located between the middle elastic bodies 32 adjacent to each other in the circumferential direction between the pair of end elastic bodies 31 from the outer side in the radial direction and define the liquid chambers 14a and 14b between it and the inner mounting member 11. For example, water and ethylene glycol or the like are enclosed in the liquid chambers 14a and 14b. The covering member 17 is formed of a harder material than the material forming the elastic bodies 31 and 32, for example, a synthetic resin material or the like. The covering member 17 is fitted between the pair of end elastic bodies 31 while being axially sandwiched.

[0020] The covering member 17 surrounds the inner mounting member 11 from the outer side in the radial direction over the entire circumference. The inner surface of the covering member 17 is in liquid-tight contact with the outer surface of the middle elastic body 32 and is not in contact with the stopper elastic parts 34.

[0021] Either one of the axial ends of the covering member 17 and the end flange portion 31a of the end elastic body 31 are axially sandwiched and fixed by a fixing portion 23 formed at either one of the axial ends of the outer cylinder 12. In the present embodiment, a fixing flange portion 17c that protrudes radially outward and extends in the circumferential direction is formed at the one end of the covering member 17, and the fixing flange portion 17c and the rigid body plate 33 are axially sandwiched and fixed by the fixing portion 23. The fixing flange portion 17c and the radially outer end portion of the rigid body plate 33 are axially laminated via a rubber film. Note that the fixing flange portion 17c may not be formed on the covering member 17.

[0022] The fixing portion 23 has a circumferential groove that is recessed radially outward and continuously extends over the entire circumferential length. The fixing flange portion 17c and the end flange portion 31a are fitted into this circumferential groove over the entire circumferential length together with the rigid body plate 33. The fixing portion 23 is formed by bending the one end of the outer cylinder 12 and bulging radially outward.

[0023] A support protrusion 24 that protrudes radially inward is formed at the other end of the outer cylinder 12 in the axial direction, and supports either one of the axial ends of the covering member 17 in the axial direction. The support protrusion 24 is formed by bending the other end of the outer cylinder 12 into a flange shape. The support protrusion z4 supports the other end of the covering member 17 in the axial direction via the end flange portion 31a of the end elastic body 31.

[0024] Hereinafter, in the axial direction, the side where the fixing portion 23 of the outer cylinder 12 is located is referred to as the upper side, and the side where the support protrusion 24 of the outer cylinder 12 is located is referred to as the lower side.

[0025] And in the present embodiment, an orifice passage that communicates the liquid chambers 14a and 14b with each other is provided between the end elastic body 31 and the end face facing the axial direction of the covering member 17. The orifice passage is provided on the upper end surface 17a of the covering member 17. This upper end surface 17a is a flat surface facing upward. Incidentally, the orifice passage may be provided on the lower end surface 17b of the covering member 17.

[0026] At the upper end portion of the covering member 17, a main body groove 19 extending in the circumferential direction, one of the liquid chambers 14a and 14b, a first communication opening 18 opening into the main body groove 19, the other of the liquid chambers 14a and 14b, and a second communication opening 20 opening into the main body groove 19 are formed. The main body groove 19 is formed on the upper end surface 17a of the covering member 17, and the first communication opening 18 and the second communication opening 20 open into the inner surface of the covering member 17. The upper end opening of the main body groove 19 is liquid-tightly closed by the end flange portion 31a of the end elastic body 31.

[0027] The covering member 17 includes a plurality of divided bodies 15 divided in the circumferential direction, and the circumferential edges 15a of the divided bodies 15 adjacent to each other in the circumferential direction abut against each other to form a cylindrical shape as a whole. The two divided bodies 15 are formed in the same shape and the same size. Incidentally, as the covering member 17, a configuration in which the whole is integrally formed in a cylindrical shape may be adopted. The covering member 17 covers the middle elastic body 32 over the entire circumference. The circumferential edge 15a of the divided body 15 is located at the central portion in the circumferential direction of the middle elastic body 32.

[0028] The outer cylinder 12 is externally fitted to the covering member 17, and the fixing portion 23 and the support protrusion 24 sandwich the covering member 17 in the axial direction via the end elastic body 31, whereby the outer cylinder 12 and the inner mounting member 11 are elastically connected, and an orifice passage communicating the liquid chambers 14a and 14b with each other is defined between the end elastic body 31 and the upper end surface 17a of the covering member 17. The orifice passage communicates the liquid chambers 14a and 14b with each other through the first communication opening 18 and the second communication opening 20. When vibration is input to the vibration isolator 1, the elastic bodies 31 and 32 are elastically deformed, and the internal volumes of the liquid chambers 14a and 14b fluctuate, causing the liquid in the liquid chambers 14a and 14b to flow through the orifice passage to generate liquid column resonance, thereby attenuating and absorbing the vibration.

[0029] As described above, according to the vibration isolator 1 according to the present embodiment, since the orifice passage communicating the liquid chambers 14a and 14b with each other is provided between the end elastic body 31 and the upper end surface 17a of the covering member 17, the end elastic body 31 is pressed against the upper end surface 17a of the covering member 17 in a state of being fitted into the outer cylinder 12, so that the sealing performance of the liquid flowing through the orifice passage can be surely ensured. Thereby, in order to ensure the sealing performance of the liquid flowing through the orifice passage, it is possible to eliminate the need to, for example, improve the dimensional accuracy of the covering member 17 or vulcanize and adhere a rubber film for sealing to other members such as the outer cylinder 12, and the manufacturing cost can be suppressed.

[0030] Next, the vibration isolator 2 according to the second embodiment will be described with reference to FIG. 3. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted, and only the differences will be described.

[0031] In the present embodiment, the covering member 17 includes a first divided body 28 and a second divided body 29 that are axially divided into two parts. The first divided body 28 is provided above the second divided body 29. The first divided body 28 has the upper end surface 17a of the covering member 17, and the second divided body 29 has the lower end surface 17b of the covering member 17. The axial size of the first divided body 28 is smaller than the axial size of the second divided body 29. The first divided body 28 faces the end connecting portion 31b in the radial direction over substantially the entire axial length.

[0032] The same main body groove 19 and first communication opening 18 as those in the first embodiment are formed in the first divided body 28. Of the two axial end portions of the second divided body 29, a second main body groove 29a extending in the circumferential direction is formed at the upper end portion axially adjacent to the first divided body 28, and the other liquid chamber 14b of the liquid chambers 14a and 14b, and a second communication opening 29c opening into the second main body groove 29a are formed. The second main body groove 29a is formed in the butting surface (upper end surface) 29b of the second divided body 29 that abuts the first divided body 28 axially. The main body groove 19 and the second main body groove 29a communicate axially through a through hole (not shown) formed in the butting surface (lower end surface) 28b of the first divided body 28 that abuts the second divided body 29 axially. The butting surfaces 28b and 29b of the first divided body 28 and the second divided body 29 respectively are flat surfaces facing the axial direction.

[0033] As described above, according to the vibration isolator 2 of the present embodiment, the covering member 17 includes the first divided body 28 and the second divided body 29 that are axially divided into two parts, and the orifice passage is provided integrally between the end elastic body 31 and the upper end surface 17a of the first divided body 28, and between the butting surfaces 28b and 29b of the first divided body 28 and the second divided body 29 that abut each other axially. Therefore, while reliably ensuring the sealing performance of the liquid flowing through the orifice passage, the length of the orifice passage can be easily ensured.

[0034] Note that 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.

[0035] It is not necessary to provide the rigid body plate 33 on the end elastic body 31, and it is not necessary to form the fixing portion 23 and the supporting protrusion 24 on the outer cylinder 12. In the second embodiment, the first divided body 28 may be formed of a soft material such as an elastomer and rubber, which is softer and more elastic than the second divided body 29.

[0036] In addition, within the scope not departing from the gist of the present invention, it is possible to appropriately replace the constituent elements in the above-described embodiments with well-known constituent elements, and the above-described embodiments and modification examples may be appropriately combined.

Explanation of Reference Numerals

[0037] 1, 2 Vibration isolator 11 Inner mounting member 12 Outer cylinder 14a, 14b Liquid chamber 17 Coating member 17a Upper end surface (end surface) 26c Concave portion 28 First divided body 28b, 29b Butting surfaces 29 Second divided body 31 End elastic body (elastic body) 32 Middle elastic body (elastic body) O Central axis line

Claims

1. An inner mounting member connected to either one of a vibration generating portion and a vibration receiving portion, and an outer cylinder connected to the other and surrounding the inner mounting member, an elastic body that elastically connects the inner mounting member and the outer cylinder, the elastic body includes middle elastic bodies separately disposed on both sides sandwiching the inner mounting member in a radial direction intersecting the central axis in a plan view seen from an axial direction along the central axis of the outer cylinder, between the inner mounting member and the outer cylinder, a covering member is disposed that covers between the middle elastic bodies adjacent to each other in a circumferential direction that circulates around the central axis in the plan view from the outside in the radial direction and defines a liquid chamber between the covering member and the inner mounting member, the elastic body includes a pair of end elastic bodies that are spaced apart in the axial direction, fitted into the outer cylinder, and sandwich the covering member in the axial direction, a vibration isolation device in which an orifice passage communicating the liquid chambers with each other is provided between the end elastic body and an end face of the covering member facing the axial direction by hermetically closing a groove formed in the end face of the covering member facing the axial direction with the end elastic body.

2. the covering member includes a first divided body and a second divided body that are divided into two in the axial direction, the orifice passage is provided between the end elastic body and the end face of the first divided body facing the axial direction by hermetically closing a groove formed in the end face of the first divided body facing the axial direction with the end elastic body, and is formed between the butting surfaces of the first divided body and the second divided body that are butted against each other in the axial direction by hermetically closing a groove formed in an end face of one of the first divided body and the second divided body facing the axial direction with the other of the first divided body and the second divided body. The vibration isolation device according to claim 1.

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