Vibration isolation device

Abstract

To provide a highly reliable vibration isolation device capable of isolating vibration in various direction inexpensively over a wide range through simple adjustment and capable of easily controlling vibration absorption performance and damping performance.SOLUTION: A vibration isolation device includes: a bolt; a first disc spring having a first insertion hole, a first inner peripheral part and a first outer peripheral part; a second disc spring having a second insertion hole, a second inner peripheral part and a second outer peripheral part; a sleeve including a pair of end surfaces through which a bolt is inserted, that oppose to each other in the axial direction and on which the first inner peripheral part and the second inner peripheral part are nipped, respectively by using a fastening tool; and a fixation plate in which the first outer peripheral part and the second outer peripheral part are fixed in an overlapped state and a displacement region of the bolt and the sleeve is opened. The first disc spring has a plurality of first vibration isolation bodies, and the second disc spring has a plurality of second vibration isolation bodies. When vibration is input to the bolt via a vibration isolated member, each of the first vibration isolation bodies and each of the second vibration isolation bodies absorb the vibration and damp the vibration, respectively at positions apart from the sleeve.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vibration isolation device.

Background Art

[0002] Patent Document 1 discloses a vibration isolation device having a mounting portion on which an object to be vibration-isolated is placed, a support portion that supports the mounting portion, and a connection mechanism that connects the mounting portion and the support portion. The connection mechanism has at least two elastic bodies with one end side mounted on the mounting portion and the other end side mounted on the support portion. Each elastic body is curved so as to have at least two inflection points, and further has a change mechanism for changing the position and angle at which each elastic body is mounted on the support portion.

[0003] Specifically, the elastic body is a leaf spring member, and the change mechanism has a mounting plate, a moving member, and a rail member. The mounting plate is rotatably attached to the moving member about a hinge, and a screw member is used for attaching the leaf spring member to the mounting plate. By operating the screw member, the position and angle of the leaf spring member with respect to the support portion can be changed. By making such a change, the position of the inflection point of each leaf spring member can be changed, the force with which each leaf spring member pushes up the mounting portion can be adjusted, and thus the vibration absorption performance of the vibration isolation device can be controlled.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As shown in FIG. 14 of Patent Document 1, the vibration isolation device has, for example, five leaf spring members each equipped with a change mechanism. The change mechanism has a complex configuration as described above, and each leaf spring member must be individually adjusted so that the overall balance can be achieved with each change mechanism. Therefore, the vibration isolation adjustment work requires a lot of effort. In addition, the adjustment work can only be performed within the range in which the screw member can be screwed forward or backward, so the range of vibration isolation adjustment is inevitably narrow.

[0006] In addition, the vibration-isolating device includes, for example, five leaf spring members as described above, and is also composed of many other members. Therefore, there is a problem that the manufacturing cost of the vibration-isolating device is high, and the leaf spring members and the changing mechanisms, which are prone to stress concentration, are prone to damage over time. Therefore, there is a demand for a highly reliable vibration-isolating device that can absorb vibrations in various directions over a wide range at low cost by simple adjustment, and that can easily control the vibration absorption and damping performance.

[0007] The present invention has been made in consideration of these problems, and aims to provide a highly reliable vibration-damping device that can absorb vibrations in various directions over a wide range at low cost through simple adjustments, and whose vibration-absorbing and damping performance can be easily controlled. [Means for solving the problem]

[0008] To achieve the above object, the vibration isolation device of the present invention is a vibration isolation device for vibration-isolating a vibration-isolated member, and includes a bolt to which the vibration-isolated member is attached, a first washer spring that is convexly curved on one side and has a first insertion hole through which the bolt is inserted at the central portion in the radial direction, a first inner peripheral portion formed at the periphery of the first insertion hole, and a first outer peripheral portion formed on the outer side in the radial direction, a second washer spring that is convexly curved on the other side opposite to the first washer spring and has a second insertion hole through which the bolt is inserted at the central portion in the radial direction, a second inner peripheral portion formed at the periphery of the second insertion hole, and a second outer peripheral portion formed on the outer side in the radial direction, a sleeve through which the bolt is inserted and which has a pair of end faces facing each other in the axial direction, and the first inner peripheral portion and the second inner peripheral portion are respectively clamped to the end faces by a fastener, and a fixing plate in which the first outer peripheral portion and the second outer peripheral portion are fixed in a superimposed state and the displacement regions of the bolt and the sleeve are opened. The first washer spring has a plurality of first vibration isolation bodies formed radially in a plan view from the first inner peripheral portion to the first outer peripheral portion, the second washer spring has a plurality of second vibration isolation bodies formed radially in a plan view from the second inner peripheral portion to the second outer peripheral portion, and when vibration is input to the bolt through the vibration-isolated member, each of the first vibration isolation bodies and each of the second vibration isolation bodies absorb the vibration and attenuate the vibration at positions separated by the sleeve.

Effect of the Invention

[0009] According to the present invention, it is possible to provide a highly reliable vibration isolation device that can isolate vibrations in various directions with simple adjustment, over a wide range, and at low cost, and can easily control the vibration absorption performance and the damping performance.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0011] Hereinafter, the vibration isolation device 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a perspective view of the vibration isolation device 1 according to the embodiment, and FIG. 2 shows a cross-sectional view of the vibration isolation device 1. The vibration isolation device 1 is used to isolate the vibration of the vibration-isolated member 2 (see FIG. 2), and includes a bolt 4, a first disc spring 10, a second disc spring 20, a pair of nuts (fasteners) 6, a sleeve 30, and a fixing plate 40. The vibration-isolated member 2 is a member expected to prevent the transmission of external vibration, and is, for example, a substrate on which various sensors and cameras and other precision devices are mounted, and is attached to the vibration isolation device 1 by the bolt 4.

[0012] FIG. 3 shows a perspective view of the first disc spring 10. Note that the first and second damping members 66 and 76 described later are not shown in FIG. 3. In the case of this embodiment, since the first disc spring 10 and the second disc spring 20 are parts of the same shape, the second disc spring 20 will also be described together with reference to FIG. 3. The first disc spring 10 is curved convexly upward (on one side), and has a first insertion hole 12, a first inner peripheral portion 14, and a first outer peripheral portion 16. The first insertion hole 12 is formed at the center in the radial direction of the first disc spring 10 and the bolt 4 is inserted therethrough. The first inner peripheral portion 14 is formed as an annular flat surface at the periphery of the first insertion hole 12. The first outer peripheral portion 16 is formed as an annular flat surface on the outer side in the radial direction of the first disc spring 10.

[0013] The second dish spring 20 is convexly curved downward (the other side) on the opposite side of the first dish spring 10, and has a second insertion hole 22, a second inner peripheral portion 24, and a second outer peripheral portion 26. The second insertion hole 22 is formed at the radial center of the second dish spring 20 through which the bolt 4 is inserted. The second inner peripheral portion 24 is formed as an annular flat surface at the periphery of the second insertion hole 22. The second outer peripheral portion 26 is formed as an annular flat surface on the outer side in the radial direction of the second dish spring 20. The first and second dish springs 10 and 20 are made of metal and are integrally manufactured by press molding or the like from a sheet metal of stainless steel such as SUS301, for example.

[0014] The sleeve 30 is made of metal, for example, and is formed from an aluminum alloy, for example. As shown in FIG. 2, the bolt 4 is inserted therethrough, and it has a pair of end faces 32 facing in the axial direction (vertical direction). A pair of nuts 6 screwed onto the bolt 4 sandwich the first inner peripheral portion 14 of the first dish spring 10 and the second inner peripheral portion 24 of the second dish spring 20 against each end face 32, respectively. Also, it is preferable that the first dish spring 10 and the second dish spring 20 in a pre-compressed state are fixed to the sleeve 30, respectively. In other words, the length L along the axial direction of the sleeve 30 is preferably set to a value such that the first dish spring 10 and the second dish spring 20 are supported in a pre-compressed state with a certain degree of curvature.

[0015] Also, the sleeve 30 is a replaceable member. When replacing the sleeve 30, one of each nut 6 and one of the first and second dish springs 10 and 20 that the nut 6 abuts against are removed from the bolt 4. Thereby, the sleeve 30 can be easily replaced with one having a desired length L. Thus, the sleeve 30 of the present embodiment constitutes an anti-vibration adjustment mechanism 8 for adjusting the vibration absorption performance and damping performance of the anti-vibration device 1 by making the length L along its axial direction different.

[0016] As shown in FIGS. 1 and 2, the fixing plate 40 is made of, for example, metal, and is fixed in a state where the first outer peripheral portion 16 of the first disc spring 10 and the second outer peripheral portion 26 of the second disc spring 20 are overlapped. Specifically, an overlapping portion where the first outer peripheral portion 16 and the second outer peripheral portion 26 are overlapped is pressed against the fixing plate 40 by a washer-shaped pressing plate 42 and fixed by a bolt 44. Further, a displacement region 46 of the bolt 4 and the sleeve 30 is opened inside the fixing plate 40 in the radial direction of the pressing plate 42.

[0017] As shown by the arrow in FIG. 2, the displacement region 46 is set to a size such that not only the bolt 4 and the sleeve 30 but also the first disc spring 10 and the second disc spring 20 do not contact the fixing plate 40 even when the vibration isolation member 2 vibrates up and down or swings left and right. Further, the fixing plate 40 is formed with bolt holes 50 (see FIG. 1) for bolt-fixing to the mounting member 48 (see FIG. 2) of the vibration isolation device 1.

[0018] Here, as shown in FIG. 3, the first disc spring 10 has a plurality of first vibration isolation bodies 60 formed radially in a plan view from the first inner peripheral portion 14 to the first outer peripheral portion 16. On the other hand, the second disc spring 20 has a plurality of second vibration isolation bodies 70 formed radially in a plan view from the second inner peripheral portion 24 to the second outer peripheral portion 26. And when vibration is input to the bolt 4 through the vibration isolation member 2, each of the first vibration isolation bodies 60 and each of the second vibration isolation bodies 70 absorb vibration and attenuate vibration at positions separated by the sleeve 30.

[0019] More specifically, the first vibration isolation body 60 is formed as a first tapered surface portion 64 separated by a first slit 62 between the first inner peripheral portion 14 and the first outer peripheral portion 16. On the other hand, the second vibration isolation body 70 is formed as a second tapered surface portion 74 separated by a second slit 72 between the second inner peripheral portion 24 and the second outer peripheral portion 26. Further, as shown in FIGS. 1 and 2, a first damping member 66 and a second damping member 76 are vulcanized and adhered to the back surface of the first tapered surface portion 64 and the back surface of the second tapered surface portion 74, respectively. The first and second damping members 66 and 76 are manufactured from, for example, high-damping rubber.

[0020] FIG. 4 shows a cross-sectional view of the vibration isolator 1 when the bolt 4 is subjected to vertical (Z-direction) vibration, FIG. 5 shows a cross-sectional view of the vibration isolator 1 when the bolt 4 is subjected to horizontal (X, Y-directions) vibration, and FIG. 6 shows a cross-sectional view of the vibration isolator 1 when the bolt 4 is subjected to torsional (RX, RY-directions) vibration. Note that FIGS. 4 to 6 are different from the forms shown in FIGS. 1 and 2, and the fastening members for sandwiching the first inner peripheral portion 14 and the second inner peripheral portion 24 on each end face 32 of the sleeve 30 are composed of the hexagonal bolt head 4a of the bolt 4 and the hexagonal nut 52 screwed onto the bolt 4. Further, FIGS. 4 to 6 are different from FIG. 2, and the first and second vibration isolators 60, 70 existing on the back side of the first and second vibration isolators 60, 70 shown in cross-section are also shown together.

[0021] As shown in FIGS. 4 to 6, when vibration is input in the arrow directions shown in each figure to the bolt 4 via the vibration-isolated member 2, the first tapered surface portion 64 and the second tapered surface portion 74 absorb the vibration by deforming at a predetermined first taper angle α and a predetermined second taper angle β, respectively. Since the first taper angle α and the second taper angle β are out of phase, when one of the first and second vibration isolators 60, 70 is in a tensile state with respect to the vibration input direction, the other of the first and second vibration isolators 60, 70 is in a compressed state. Further, when vibration is input to the bolt 4 via the vibration-isolated member 2, the first damping member 66 and the second damping member 76 damp the vibration by deforming according to the deformation amounts of the first tapered surface portion 64 and the second tapered surface portion 74, respectively.

[0022] FIG. 7 shows a table representing an example of the spring constant kz and the natural frequency fn with respect to the length L of the sleeve 30, and FIG. 8 shows a graph created based on the table of FIG. 7. The natural frequency fn in FIG. 7 indicates the values when subjected to the vertical (Z-direction) vibration shown in FIG. 4, the horizontal (X, Y-directions) vibration shown in FIG. 5, and the torsional (RX, RY-directions) vibration shown in FIG. 6, respectively. Further, in FIG. 8, the solid line indicates the spring constant kz, and the broken line indicates the natural frequency fn when subjected to vertical vibration.

[0023] As is apparent from FIGS. 7 and 8, as the length L of the sleeve 30 increases, the spring constant kz and the natural frequency fn increase, and in particular, the spring constant kz increases exponentially and rapidly. More specifically, when the sleeve is changed from one with a length L of 6 mm to one with a length L of 24 mm, which is four times the length, the spring constant kz increases approximately 10-fold from 2.5 N / mm to 25.7 N / mm. That is, by simply replacing the sleeve with one of a different length L, the spring stiffness of the vibration isolation device 1 can be adjusted over a wide range of approximately 10-fold.

[0024] Also, when the sleeve 30 is changed from one with a length L of 6 mm to one with a length L of 24 mm, which is four times the length, when the bolt 4 is subjected to vertical vibration, the natural frequency fn increases approximately 3-fold from 8.2 Hz to 25.8 Hz. Also, when the bolt 4 is subjected to horizontal vibration, the natural frequency fn increases approximately 1.5-fold from 81.6 Hz to 121.2 Hz. Further, when the sleeve 30 is changed from one with a length L of 6 mm to one with a length L of 16 mm, which is approximately 2.7 times the length, when the bolt 4 is subjected to torsional vibration, the natural frequency fn increases approximately 8.1-fold from 175.6 Hz to 1421.8 Hz. Thus, it is clear from the data in FIGS. 7 and 8 that the sleeve 30 effectively functions as a vibration isolation adjustment mechanism 8 for adjusting the vibration absorption performance and damping performance of the vibration isolation device 1.

[0025] As described above, the vibration isolation device 1 of the present embodiment includes the bolt 4, the first disc spring 10, the second disc spring 20, the nut 6, the sleeve 30, and the fixing plate 40 described above. The first disc spring 10 has each first vibration isolation body 60, and the second disc spring 20 has each second vibration isolation body 70. And when vibration is input to the bolt 4 via the vibration isolation member 2, each first vibration isolation body 60 and each second vibration isolation body 70 absorb and attenuate the vibration at positions separated by the sleeve 30.

[0026] Specifically, each first vibration isolator 60 of the first dish spring 10 curved convexly in different directions and each second vibration isolator 70 of the second dish spring 20 receive vibration at positions separated by the sleeve 30. Thus, when one of the first and second vibration isolators 60 and 70 is in a tensile state with respect to the vibration input direction, the other of the first and second vibration isolators 60 and 70 is in a compressed state. Thereby, by setting the sleeve 30 to a specific length L, the spring rigidity of the vibration isolation device 1 can be adjusted over a wide range of approximately 10 times. Therefore, vibration isolation adjustment can be performed over a wider range compared to the prior art.

[0027] Also, each first vibration isolator 60 is integrally formed with the first dish spring 10, and each second vibration isolator 70 is integrally formed with the second dish spring 20. Thereby, since it is not necessary to individually adjust a large number of spring members with their respective changing mechanisms, the work related to vibration isolation adjustment can be significantly simplified compared to the prior art. In addition, since the vibration isolation device 1 has fewer parts and no complicated mechanism compared to the prior art, the manufacturing cost and the risk of breakage can be reduced.

[0028] As described above, it is possible to provide a highly reliable vibration isolation device 1 that can isolate vibrations in various directions with simple adjustment, over a wide range, and at low cost, and whose vibration absorption performance and damping performance can be easily controlled. Also, as described above, the sleeve 30 constitutes a vibration isolation adjustment mechanism 8 for adjusting the vibration absorption performance and damping performance of the vibration isolation device 1 by making the length L along its axial direction different. Thereby, since vibration isolation adjustment can be performed only by replacing the sleeve 30, the work related to vibration isolation adjustment can be further effectively simplified.

[0029] Also, when vibration is input to the bolt 4 via the vibration isolation member 2, the first tapered surface portion 64 and the second tapered surface portion 74 absorb the vibration by deforming at the first taper angle α and the second taper angle β, respectively. Since the first taper angle α and the second taper angle β are out of phase, when one of the first and second vibration isolators 60 and 70 is in a tensile state with respect to the vibration input direction, the other of the first and second vibration isolators 60 and 70 is in a compressed state. Thereby, the vibration absorption performance of the vibration isolation device 1 can be suitably exhibited.

[0030] Further, a first damping member 66 and a second damping member 76 are adhered to the back surface of the first tapered surface portion 64 and the back surface of the second tapered surface portion 74, respectively. When vibration is input to the bolt 4 via the vibration isolation member 2, the first damping member 66 and the second damping member 76 attenuate the vibration by deforming according to the amount of deformation of the first tapered surface portion 64 and the second tapered surface portion 74, respectively. Thereby, the damping performance of the vibration isolation device 1 can be preferably exhibited.

[0031] Further, the sleeve 30 has a length L capable of supporting the first disc spring 10 and the second disc spring 20 in a pre-compressed state, respectively. Thereby, the vibration absorption performance and the damping performance can be preferably exhibited from the initial stage of operation of the vibration isolation device 1. Further, in the case of the present embodiment, since the first disc spring 10 and the second disc spring 20 are parts of the same shape, the manufacturing cost of the vibration isolation device 1 can be further effectively reduced.

[0032] This concludes the description of the embodiments of the present invention. However, 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 vibration isolation device 1 of the above embodiment, the first disc spring 10 and the second disc spring 20 are parts of the same shape. However, depending on the required vibration isolation mode, the first disc spring 10 and the second disc spring 20 may have different shapes and different vibration isolation performances.

[0033] Further, depending on the required vibration isolation mode, the number of the first vibration isolation bodies 60 of the first disc spring 10 and the number of the second vibration isolation bodies 70 of the second disc spring 20 may be different. Further, the vibration isolation adjustment mechanism 8 may be a mechanism capable of adjusting the length L of the sleeve 30 by the telescopic sleeve 30. Thereby, since the vibration isolation adjustment can be performed without replacing the sleeve 30, the work related to the vibration isolation adjustment can be further simplified.

[0034] Furthermore, the vibration isolator 1 may be formed by stacking a plurality of first dish springs 10 and a plurality of second dish springs 20 respectively. This enables it to cope with even higher load-bearing requirements. Also, the frictional force generated between the overlapping first dish springs 10 and the frictional force generated between the overlapping second dish springs 20 can further enhance the damping performance of the vibration isolator 1.

Explanation of Signs

[0035] 1 Vibration isolator 2 Vibration-isolated member 4 Bolt 4a Bolt head (fastener) 6 Nut (fastener) 8 Vibration isolation adjustment mechanism 10 First dish spring 12 First insertion hole 14 First inner peripheral part 16 First outer peripheral part 20 Second dish spring 22 Second insertion hole 24 Second inner peripheral part 26 Second outer peripheral part 30 Sleeve 32 End face 40 Fixing plate 46 Displacement region 52 Hexagonal nut (fastener) 60 First vibration isolator 62 First slit 64 First tapered surface part 66 First damping member 70 Second vibration isolator 72 Second slit 74 Second tapered surface part 76 Second damping member L Length of sleeve α First taper angle β Second taper angle

Claims

1. An anti-vibration device for anti-vibrating a vibration-isolation member, comprising: a bolt to which the vibration-isolation member is attached; a first disc spring having a convex curvature on one side, a first insertion hole formed at the center in the radial direction through which the bolt is inserted, a first inner peripheral portion formed at the periphery of the first insertion hole, and a first outer peripheral portion formed on the outer side in the radial direction; a second disc spring having a convex curvature on the other side opposite to the first disc spring, a second insertion hole formed at the center in the radial direction through which the bolt is inserted, a second inner peripheral portion formed at the periphery of the second insertion hole, and a second outer peripheral portion formed on the outer side in the radial direction; a sleeve through which the bolt is inserted and having a pair of end faces facing each other in the axial direction, and the first inner peripheral portion and the second inner peripheral portion are respectively clamped to the respective end faces by a fastener; a fixing plate fixed in a state where the first outer peripheral portion and the second outer peripheral portion are overlapped, and the displacement regions of the bolt and the sleeve are opened; and comprising: The first disc spring has a plurality of first anti-vibration bodies formed radially in a plan view from the first inner peripheral portion to the first outer peripheral portion; The second disc spring has a plurality of second anti-vibration bodies formed radially in a plan view from the second inner peripheral portion to the second outer peripheral portion; Each of the first anti-vibration bodies and each of the second anti-vibration bodies absorb and attenuate the vibration at positions separated by the sleeve when vibration is input to the bolt via the vibration-isolation member. An anti-vibration device.

2. The anti-vibration device according to claim 1, wherein the sleeve constitutes an anti-vibration adjustment mechanism for adjusting the vibration absorption performance and attenuation performance of the anti-vibration device by making the lengths along its axial direction different.

3. The first anti-vibration body is a first tapered surface portion separated by a first slit between the first inner peripheral portion and the first outer peripheral portion; The second anti-vibration body is a second tapered surface portion separated by a second slit between the second inner peripheral portion and the second outer peripheral portion; The first tapered surface portion and the second tapered surface portion absorb the vibration by deforming at a predetermined first taper angle and a predetermined second taper angle, respectively, when the vibration is input to the bolt via the vibration isolation member. The vibration isolation device according to claim 2.

4. The vibration isolation device according to claim 3, wherein the first taper angle and the second taper angle are out of phase.

5. A first damping member and a second damping member are respectively adhered to the back surface of the first tapered surface portion and the back surface of the second tapered surface portion. The first damping member and the second damping member damp the vibration by deforming according to the deformation amounts of the first tapered surface portion and the second tapered surface portion, respectively, when the vibration is input to the bolt via the vibration isolation member. The vibration isolation device according to claim 4.

6. The sleeve has a length capable of supporting the first disc spring and the second disc spring in a pre-compressed state, respectively. The vibration isolation device according to claim 5.

7. The vibration isolation device according to any one of claims 1 to 6, wherein the first disc spring and the second disc spring are parts of the same shape.

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