Elastic device, isolator, and wheel

Abstract

An elastic device (1, 30, 40, 50) comprises: an inner member (4); an outer member (6) disposed separated in the radial direction of the inner member (4) so as to surround the inner member (4); and a wire rope (8) that connects the inner member (4) and the outer member (6). Overall, the wire rope (8) is radially extended in a torus shape between the inner member (4) and the outer member (6).

Description

Resilient devices, isolators and wheels

[0001] The present invention relates to a resilient device, an isolator including the resilient device, and a wheel including the resilient device.

[0002] Isolators using a wire rope formed by twisting together a number of metal wires as a buffer material are known. Such isolators can effectively absorb vibrations from a vibration-damped member by utilizing the elastic properties of the entire wire rope and the damping properties due to friction between the metal wires that make up the wire rope. For example, Patent Document 1 discloses a helical isolator that includes a pair of fixing members each having a plurality of support holes formed in series, and a wire rope that is wound helically and threads through the support holes. When vibrations are input in the opposing direction between the pair of fixing members, this isolator absorbs the vibrations transmitted to the vibration-damped member by deforming the curved wire rope in a crushing manner.

[0003] JP 2011-64244 A

[0004] In the above-mentioned isolator, when the vibration input direction is misaligned with the opposing direction of the pair of fixed members, the fixed members receiving the vibration are displaced in their longitudinal direction, preventing the wire rope from being crushed or deformed properly, resulting in ineffective vibration absorption. In this case, a separate mechanism must be installed to prevent the fixed members from being displaced, which increases the number of parts in the isolator, complicates the isolator structure, and increases the isolator's manufacturing costs. Therefore, there is a need for an elastic device that can absorb vibrations in various input directions at low cost, an isolator equipped with such an elastic device, and a wheel equipped with such an elastic device.

[0005] The present invention has been made in consideration of these problems, and aims to provide an elastic device that can absorb vibrations in various input directions at low cost, an isolator equipped with the elastic device, and a wheel equipped with the elastic device.

[0006] To achieve the above object, the elastic device of the present invention includes an inner member, an outer member arranged radially apart from the inner member so as to surround the inner member, and a wire rope connecting the inner member and the outer member, the wire rope extending radially between the inner member and the outer member to form a torus shape as a whole. The isolator of the present invention is an isolator including the elastic device described above, in which a vibration-damped member is connected to the inner member and the outer member is fixed to a fixed member. The wheel of the present invention is a wheel including the elastic device described above, in which the inner member is a boss to which an axle is connected and the outer member is an outer ring of the wheel.

[0007] According to the present invention, there are provided an elastic device capable of absorbing vibrations in various input directions at low cost, an isolator including the elastic device, and a wheel including the elastic device.

[0008] Fig. 1 is a perspective view of an isolator equipped with a resilient device according to a first embodiment of the present invention; Fig. 2 is a perspective view of an isolator equipped with a resilient device according to a second embodiment of the present invention; Fig. 3 is a top view of the isolator as seen from above in Fig. 2; Fig. 4 is a perspective view of an isolator equipped with a resilient device according to a third embodiment of the present invention; Fig. 5 is a top view of the isolator as seen from above in Fig. 4; Fig. 6 is a perspective view of a wheel equipped with a resilient device according to a fourth embodiment of the present invention;

[0009] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a perspective view of an isolator 2 including an elastic device 1 according to a first embodiment of the present invention. The elastic device 1 includes an inner member 4, an outer member 6 arranged radially apart from the inner member 4 so as to surround the inner member 4, and a wire rope 8 connecting the inner member 4 and the outer member 6. The inner member 4 is cylindrical, and a bolt 10 is inserted and connected to the radial center thereof. A vibration-damped member (not shown) is connected to the inner member 4 via the bolt 10. The vibration-damped member is a member expected to prevent transmission of vibrations from the outside, such as a circuit board on which precision instruments such as various sensors and cameras are mounted.

[0010] The outer member 6 is formed, for example, in the shape of a rectangular plate, and a displacement region 12 for the inner member 4 and the bolt 10 is opened in its radial center. The displacement region 12 is set to a size such that not only the inner member 4 and the bolt 10, but also the wire rope 8, do not come into contact with the outer member 6 even when the inner member 4 vibrates up and down or swings left and right as viewed in FIG. 1 . Furthermore, bolt holes 14 are drilled at the four corners of the outer member 6. The isolator 2 is fixed by inserting bolts (not shown) through each bolt hole 14 and fastening it to a fixed member (not shown). The wire rope 8 is formed by twisting multiple metal wires. The isolator 2 effectively absorbs vibrations transmitted from the fixed member to the vibration-damped member via the outer member 6 and inner member 4 in this order, due to the elastic properties of the entire wire rope 8 and the damping properties due to friction between the metal wires that make up the wire rope 8.

[0011] Here, in this embodiment, the wire rope 8 extends radially between the inner member 4 and the outer member 6, forming a torus shape as a whole. In other words, the wire rope 8 forms a donut-shaped annular body in the elastic device 1. The inner member 4 is held in the radial center of the displacement region 12 by this annular body, while allowing slight rotation accompanied by rolling of the inner member 4 about the axis A of the bolt 10 and slight displacement of the inner member 4 along the axis A. As a result, when the vibration input direction deviates from the axis A of the bolt 10 and the inner member 4 is displaced radially, a restoring force that returns the inner member 4 to the radial center of the displacement region 12 is exerted on the inner member 4 by the elastic force of the wire rope 8.

[0012] The restoring force acting on the inner member 4 causes the wire rope 8 to suitably collapse and deform along the axis A in response to vibration input. At this time, combined with the damping force due to friction between the metal wires constituting the wire rope 8, vibration is effectively absorbed. Furthermore, since there is no need to separately provide a mechanism for restricting radial displacement of the inner member 4, the number of parts in the elastic device 1 and therefore the isolator 2 can be reduced and their structures can be simplified. Therefore, it is possible to realize an elastic device 1 that can absorb vibrations in various input directions at low cost, and an isolator 2 equipped with this elastic device 1.

[0013] More specifically, the inner member 4 has a first connection portion 16 to which the wire rope 8 is connected. The first connection portion 16 is a flange-shaped portion that is formed at the lower end of the inner member 4 as viewed in FIG. 1 , along the circumferential direction of the outer peripheral surface 4a of the inner member 4. The outer member 6 also has a second connection portion 18 to which the wire rope 8 is connected. The second connection portion 18 is a portion that forms the opening edge of the displacement region 12 of the outer member 6. The wire rope 8 has a plurality of first rope portions 8a that are curved convexly from the first connection portion 16 and connected to the second connection portion 18, and a plurality of second rope portions 8b that are curved concavely from the first connection portion 16 and connected to the second connection portion 18. The torus shape described above is formed by arranging each of the first rope portions 8a and each of the second rope portions 8b along the circumferential direction between the inner member 4 and the outer member 6. In other words, the first rope portions 8a and the second rope portions 8b are positioned so as to sandwich the outer member 6 from above and below as viewed in Fig. 1. This allows the restoring force against radial displacement of the inner member 4 to be reliably applied over the entire circumferential area of ​​the inner member 4, effectively improving the vibration absorption performance of the elastic device 1 and, in turn, the isolator 2.

[0014] The first connecting portion 16 has a plurality of first insertion holes 20 along its circumferential direction, and the second connecting portion 18 has a plurality of second insertion holes 22 along its circumferential direction. The first rope portions 8a and the second rope portions 8b are inserted and fixed through the first insertion holes 20 and the second insertion holes 22, respectively. This prevents the wire rope 8 from moving through the first insertion holes 20 and the second insertion holes 22, ensuring that the first rope portions 8a and the second rope portions 8b constituting the wire rope 8 are reliably crushed and deformed during vibration absorption. This further effectively improves the vibration absorption performance of the elastic device 1 and the isolator 2. Note that various means, such as crimping and adhesive bonding, can be used to securely fasten the wire rope 8 to the first insertion holes 20 and the second insertion holes 22.

[0015] In this embodiment, the first rope portion 8a and the second rope portion 8b are formed on the same radial plane extending radially from the inner member 4. This shortens the horizontal distance between the first insertion hole 20 and the second insertion hole 22 through which the wire rope 8 is inserted, thereby shortening the individual first rope portion 8a and second rope portion 8b. This allows the restoring force against radial displacement of the inner member 4 to act more quickly, thereby more effectively improving the vibration absorption performance of the elastic device 1 and the isolator 2. In this embodiment, the first rope portion 8a and the second rope portion 8b are formed by inserting and fixing cut pieces of the wire rope 8 into the first insertion hole 20 and the second insertion hole 22, which are located on the same radial plane.

[0016] FIG. 2 shows a perspective view of an isolator 2 equipped with an elastic device 30 according to a second embodiment of the present invention, and FIG. 3 shows a top view of the isolator 2 as seen from above in FIG. 2. Note that components similar to those in the first embodiment are denoted by the same reference numerals in the drawings and descriptions thereof may be omitted, and the same applies to the following embodiments. In this embodiment, an odd number of first insertion holes 20 and second insertion holes 22 are formed, i.e., nine in the cases of FIGS. 2 and 3 . The first rope portion 8 a and the second rope portion 8 b are formed by alternately inserting and fixing a single wire rope 8 into the first insertion holes 20 and the second insertion holes 22, which are positioned radially offset from each other in the inner member 4.

[0017] This allows the first rope portions 8a and the second rope portions 8b to be formed from a single wire rope 8 without cutting the wire rope 8, thereby enabling the wire rope 8 to be formed into a torus shape. This further improves the productivity of the elastic device 30 and the isolator 2. Furthermore, the horizontal distance L (see FIG. 3 ) between the first insertion hole 20 and the second insertion hole 22 through which the wire rope 8 is inserted is longer than in the first embodiment, thereby enabling the individual first rope portions 8a and the second rope portions 8b to be longer than in the first embodiment. This allows the first rope portions 8a and the second rope portions 8b to undergo more gradual deformation during vibration absorption than in the first embodiment. This is therefore suitable for situations where gradual vibration absorption is desired, and adjusting this distance L allows the elastic characteristics and damping characteristics of the elastic device 30 and the isolator 2 to be easily adjusted.

[0018] Fig. 4 shows a perspective view of an isolator 2 equipped with an elastic device 40 according to a third embodiment of the present invention, and Fig. 5 shows a top view of the isolator 2 as seen from above in Fig. 4. In this embodiment, an even number of first insertion holes 20 and second insertion holes 22 are formed, i.e., ten in the cases of Figs. 4 and 5. The first rope portion 8a and the second rope portion 8b are formed by alternately inserting and fixing two wire ropes 8A, 8B into the first insertion holes 20 and the second insertion holes 22, which are positioned radially offset from each other in the inner member 4.

[0019] As a result, each of the first rope portions 8a and each of the second rope portions 8b can be formed using two wire ropes 8A and 8B, and the wire ropes 8A and 8B can be formed into a torus shape. Therefore, compared to at least the first embodiment, the productivity of the elastic device 30 and therefore the isolator 2 can be improved. Furthermore, as in the second embodiment, the horizontal distance L (see FIG. 5) between the first insertion hole 20 and the second insertion hole 22 through which the wire ropes 8A and 8B are inserted is increased, and therefore the individual first rope portions 8a and second rope portions 8b can be lengthened.

[0020] As a result, as in the second embodiment, the crushing deformation of each of the first rope portions 8a and each of the second rope portions 8b can be made slower during vibration absorption, and adjusting this distance L makes it possible to easily adjust the elastic characteristics and damping characteristics of the elastic device 30 and, in turn, the isolator 2. Furthermore, in this embodiment, the elastic characteristics and damping characteristics of the wire ropes 8A and 8B can be made different by forming the wire ropes 8A and 8B from different metal wires or by changing the number of twists of the metal wires of the wire ropes 8A and 8B. In this case, the elastic characteristics and damping characteristics of the elastic device 30 and, in turn, the isolator 2 can be adjusted over an even wider range.

[0021] FIG. 6 is a perspective view of a wheel 60 equipped with an elastic device 50 according to a fourth embodiment of the present invention. The inner member 4 of this embodiment is formed as a boss 54 having a through hole 52 at its radial center, and an axle (not shown) is connected to this boss 54. The outer member 6 of this embodiment is formed as an outer ring 56 of the wheel 60. The first connection portion 16 to which the wire rope 8 is connected in the boss 54 is formed on an end face 54a of the boss 54, and a plurality of first insertion holes 20 are formed around the circumferential direction of this end face 54a. Meanwhile, the second connection portion 18 to which the wire rope 8 is connected in the outer ring 56 is formed on an inner circumferential surface 56a of the outer ring 56, and a plurality of holding portions 58 for the wire rope 8 are formed around the circumferential direction of this inner circumferential surface 56a, and each of these holding portions 58 is formed with a second insertion hole 22.

[0022] The displacement region 12 of this embodiment is formed between the boss 54 and the outer ring 56, and is set to a size such that even if the boss 54 vibrates up and down or swings left and right as viewed in FIG. 6 , not only the boss 54 and the axle connected to the boss 54, but also the wire rope 8 will not come into contact with the outer ring 56. As in the first embodiment, the wire rope 8 of this embodiment also extends radially between the boss 54 and the outer ring 56, forming an overall torus shape. In other words, the elastic device 50 forms a donut-shaped loop of the wire rope 8. This loop of the wire rope 8 functions as a spoke of the wheel 60, and the boss 54 is held in the radial center of the displacement region 12 by this loop, while allowing slight rotation accompanying rolling of the boss 54 about the axis A of the axle and slight displacement of the boss 54 along the axis A.

[0023] As a result, when the vibration input direction deviates from the axis of the axle and the boss 54 is displaced radially, a restoring force acts on the boss 54 due to the elastic force of the wire rope 8, returning it to the radial center of the displacement region 12. This restoring force acting on the boss 54 causes the wire rope 8 to suitably crush and deform. At this time, combined with the damping force due to friction between the metal wires constituting the wire rope 8, vibrations transmitted via the axle and outer ring 56 are effectively absorbed. Furthermore, because a separate mechanism for restricting radial displacement of the boss 54 is not required, the number of parts in the elastic device 50 and thus the wheel 60 can be reduced and their structure can be simplified. Therefore, a wheel 60 capable of absorbing vibrations in various input directions can be realized at low cost.

[0024] Although the description of each embodiment of the present invention has been completed above, the present invention is not limited to the above embodiments and various modifications can be made without departing from the spirit of the present invention. For example, in the elastic device 50 used in the wheel 60 in the fourth embodiment, the first rope portion 8 a and the second rope portion 8 b may be formed on the same radial plane extending radially from the boss 54 in the radial direction thereof as in the first embodiment, the first rope portion 8 a and the second rope portion 8 b may be formed from a single wire rope 8 as in the second embodiment, or the first rope portion 8 a and the second rope portion 8 b may be formed from two wire ropes 8A, 8B as in the third embodiment.

[0025] Furthermore, the number of first rope portions 8 a and second rope portions 8 b in the elastic devices 1, 30, 40, and 50 of the above embodiments can be changed according to the required specifications, and the number of first rope portions 8 a and the number of second rope portions 8 b can be made different. Furthermore, the elastic devices 1, 30, 40, and 50 of the above embodiments can be applied to various devices, not limited to the isolator 2 and the wheel 60, and can also be used for the armature of a compressor for a car air conditioner, for example.

[0026] REFERENCE SIGNS LIST 1, 30, 40, 50 Elastic device 2 Isolator 4 Inner member 6 Outer member 8, 8A, 8B Wire rope 8a First rope portion 8b Second rope portion 16 First connecting portion 18 Second connecting portion 20 First insertion hole 22 Second insertion hole 54 Boss (inner member) 56 Outer ring (outer member) 60 Wheel

Claims

1. An elastic device comprising: an inner member; an outer member arranged radially apart from the inner member so as to surround the inner member; and a wire rope connecting the inner member and the outer member, wherein the wire rope extends radially between the inner member and the outer member while forming an overall torus shape.

2. The elastic device according to claim 1, wherein the inner member has a first connection portion to which the wire rope is connected, the outer member has a second connection portion to which the wire rope is connected, and the wire rope forms the torus shape by arranging a plurality of first rope portions that are curved convexly from the first connection portion and connected to the second connection portion, and a plurality of second rope portions that are curved concavely from the first connection portion and connected to the second connection portion, around the circumference of the inner member and the outer member.

3. An elastic device as described in claim 2, wherein the first connection portion has a plurality of first insertion holes around its circumference, the second connection portion has a plurality of second insertion holes around its circumference, and the first rope portion and the second rope portion are inserted through the first insertion holes and the second insertion holes, respectively, and fixed.

4. The resilient device according to claim 3, wherein said first rope portion and said second rope portion are formed on the same radial surface extending radially from said inner member in said radial direction thereof.

5. An elastic device as described in claim 3, wherein an odd number of the first insertion holes and the second insertion holes are formed, and the first rope portion and the second rope portion are formed by alternately inserting and fixing one wire rope through the first insertion holes and the second insertion holes at positions offset in the radial direction.

6. An elastic device as described in claim 3, wherein an even number of the first insertion holes and the second insertion holes are formed, and the first rope portion and the second rope portion are formed by alternately inserting and fixing two of the wire ropes into the first insertion holes and the second insertion holes at positions offset in the radial direction.

7. An isolator comprising an elastic device according to any one of claims 1 to 6, wherein the inner member is connected to a member to be damped, and the outer member is fixed to a member to be fixed.

8. A wheel equipped with a resilience device according to any one of claims 1 to 6, wherein the inner member is a boss to which an axle is connected, and the outer member is an outer ring of the wheel.

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