Vibration isolation device

Abstract

To provide a vibration isolation device that can reduce the generation of abnormal noises during twisting deformation. [Solution] The distance L1 (width of the first gap 14) between the first outer surface 16 and the first inner surface 17 at the center in the axial direction is 0.5 to 2.0 mm. On the other hand, the distance L2 (width of the second gap 15) between the second outer surface 18 and the second inner surface 19 at the center in the axial direction is 2.0 to 5.0 mm. The shapes of the first outer surface 16 and the first inner surface 17 are set so that they do not come into contact with each other when the twisting angle θ is 17 degrees or less. Therefore, it is possible to make it difficult to generate abnormal noises associated with their contact during twisting deformation.

Description

Technical Field

[0001] The present invention relates to a vibration isolator, and more particularly to a vibration isolator that can hardly generate abnormal noise during torsional deformation.

Background Art

[0002] Conventionally, a vibration isolator in which an outer peripheral surface of a shaft-shaped inner member and an inner peripheral surface of a cylindrical outer member are connected by a vibration isolation base made of an elastic body is known. In this vibration isolator, there are a first groove and a second groove that penetrate the vibration isolation base in the axial direction of the inner member and are formed on both sides in the radial direction with the inner member interposed therebetween.

[0003] In the vibration isolator described in Patent Document 1, the width (radial dimension) of the first groove is made narrower than the width of the second groove. Thereby, when a radial load is input to the vibration isolator, the timing at which the vibration isolation bases on both sides of the first groove come into contact and restrict bending can be made earlier, and the timing at which the vibration isolation bases on both sides of the second groove come into contact and restrict bending can be made later.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above prior art, by narrowing the width of the first groove, when the inner member is tilted with respect to the outer member in the directions of the first groove and the second groove to torsionally deform the vibration isolation base, the vibration isolation bases on both sides of the narrow first groove are likely to come into contact. Due to this contact, there is a problem that abnormal noise associated with the contact between the vibration isolation bases is likely to occur.

[0006] This invention was made to solve the above-mentioned problems, and aims to provide a vibration damping device that can reduce the generation of abnormal noise during twisting deformation. [Means for solving the problem]

[0007] To achieve this objective, the vibration isolation device of the present invention comprises an axial inner member extending along an axis, a cylindrical outer member surrounding the outer circumference of the inner member, and an elastic vibration isolation base connecting the outer surface of the inner member and the inner surface of the outer member, wherein the vibration isolation base has a first slit penetrating in the axial direction, a second slit located radially opposite to the first slit and penetrating in the axial direction so as to sandwich the inner member between them, a first outer surface of the inner wall of the first slit forming the side facing the outer member, and a portion of the inner wall of the first slit forming the side facing the inner member, with a distance of 0.5 to 2.0 mm between it and the first outer surface at the center in the axial direction. The vibration-damping base comprises a first inner surface, a second outer surface that forms the outer member side of the inner wall of the second gap, and a second inner surface that forms the inner member side of the inner wall of the second gap, with the distance from the second outer surface at the center in the axial direction set to 2.0 to 5.0 mm. The shapes of the first outer surface and the first inner surface are set such that when the vibration-damping base is twisted and deformed by tilting the inner member relative to the outer member in the direction of the first gap and the second gap, the twisting angle of the axis of the inner member with respect to the axial direction of the outer member is 17 degrees or less, and the first outer surface and the first inner surface are not in contact. [Effects of the Invention]

[0008] According to the vibration isolation device described in claim 1, the distance between the first outer surface and the first inner surface at the center in the axial direction (width of the first gap) is 0.5 to 2.0 mm. On the other hand, the distance between the second outer surface and the second inner surface at the center in the axial direction (width of the second gap) is 2.0 to 5.0 mm. By setting these distances, similar to the prior art, the timing at which the first outer surface and the first inner surface come into contact and restrict deflection when a radial load is applied to the vibration isolation device can be made earlier, while the timing at which the second outer surface and the second inner surface come into contact and restrict deflection can be made later. In such a vibration isolation device, when the vibration isolation base is twisted and deformed, the first outer surface and the first inner surface with the narrower distance will attempt to come into contact earlier. However, in this vibration isolation device, the shapes of the first outer surface and the first inner surface are set so that they do not come into contact when the twisting angle is 17 degrees or less. Therefore, it is less likely to generate abnormal noises associated with contact during twisting deformation.

[0009] The vibration isolation device described in claim 2 provides the following effects in addition to the effects of the vibration isolation device described in claim 1. The first outer surface and the second outer surface are located outside or on a cylindrical surface with the axis as its central axis, with the radius being the radial distance from the axis to the center of the first outer surface or the second outer surface in the axial direction. The first inner surface and the second inner surface are located inside a virtual spherical surface with the same radius as the virtual cylindrical surface, with the axis as its center in the axial direction of the inner member. During simple twisting deformation, the first inner surface and the second inner surface move around the center of the virtual spherical surface, so they do not extend outside the virtual spherical surface. This prevents the first outer surface and the first inner surface, or the second outer surface and the second inner surface, from coming into contact during simple twisting deformation. Therefore, it is possible to make it less likely for abnormal noise to be generated during twisting deformation due to contact between them.

[0010] The vibration isolation device described in claim 3 provides the following effects in addition to the effects of the vibration isolation device described in claim 2. The first outer surface and the second outer surface each have a plurality of axial projections extending in the axial direction, arranged in the circumferential direction. The first inner surface and the second inner surface each have a plurality of circumferential projections extending in the circumferential direction, arranged in the axial direction. When the first outer surface and the first inner surface come into contact, or when the second outer surface and the second inner surface come into contact, the plurality of axial projections and circumferential projections, which are oriented in different directions from each other, first make point contact, and then the contact area gradually expands. This makes it possible to suppress abnormal noise associated with their contact.

[0011] When manufacturing a vibration-damping base using a mold that opens on both sides in the axial direction, multiple circumferential projections extending in the circumferential direction and aligned in the axial direction are formed by forced extraction. However, the first and second inner surfaces on which the circumferential projections are provided are located inside a hypothetical spherical surface, with a predetermined distance between them and the first and second outer surfaces at the axial center. Therefore, the first and second inner surfaces tend to tilt more sharply with respect to the axis as they move away from the axial center than the first and second outer surfaces. Since the circumferential projections formed by forced extraction are provided on the first and second inner surfaces, which have a greater tilt, rather than the first and second outer surfaces, which have a smaller tilt, the force required during forced extraction can be reduced. Thus, the workability when removing the vibration-damping base from the mold can be improved.

[0012] The vibration isolation device described in claim 4 provides the following effects in addition to the effects of the vibration isolation device described in any one of claims 1 to 3: In a cross-section including the axial center of the first outer surface and the first inner surface, the area of ​​the vibration isolation base excluding the first sill is 60% or more in the range where the opposing portions of the first inner surface and the first outer surface are projected radially between the inner member and the outer member. Furthermore, in a cross-section including the axial center of the second outer surface and the second inner surface, the area of ​​the vibration isolation base excluding the second sill is 60% or more in the range where the opposing portions of the second inner surface and the second outer surface are projected radially between the inner member and the outer member. As a result, excessive deformation of the vibration isolation base can be suppressed when a radial load is applied that crushes the first or second sill, and the durability of the vibration isolation base can be ensured. [Brief explanation of the drawing]

[0013] [Figure 1] This is a top view of the vibration isolation device in the first embodiment. [Figure 2] This is a cross-sectional view of the vibration isolation device along line II-II in Figure 1. [Figure 3] This is a cross-sectional view of the vibration isolation device along line III-III in Figure 1. [Figure 4] Figure 2 is a cross-sectional view of the vibration isolation device along line IV-IV. [Figure 5] This is a cross-sectional view of the vibration isolation device during twisting deformation. [Figure 6] This is a cross-sectional view of the vibration isolation device in the second embodiment. [Figure 7] Figure 6 is a cross-sectional view of the vibration isolation device along line VII-VII. [Modes for carrying out the invention]

[0014] Preferred embodiments will be described below with reference to the attached drawings. Figure 1 is a top view of the vibration isolation device 10 in the first embodiment. Figure 2 is a cross-sectional view of the vibration isolation device 10 along the line II-II in Figure 1. Figure 3 is a cross-sectional view of the vibration isolation device 10 along the line III-III in Figure 1. Figure 4 is a cross-sectional view of the vibration isolation device 10 along the line IV-IV in Figure 2.

[0015] The arrows U, D, L, R, F, and B in each drawing indicate the upward, downward, leftward, rightward, forward, and backward directions of the vibration isolation device 10, respectively. The vertical, leftward, and forward / backward directions are perpendicular to each other. Note that these directions are set for the sake of explanation and may or may not coincide with the actual vertical direction, etc. Also, the vibration isolation device 10 in Figures 1 to 4 all show the device in an unloaded state where no vibration is applied. Unless otherwise specified, the explanation using these figures will describe the vibration isolation device 10 in an unloaded state.

[0016] As shown in FIGS. 1 and 2, the vibration isolator 10 is a vibration isolation bush for elastically coupling a vibration source side such as an engine, a motor, or an arm of a suspension mechanism of an automobile to a vibration receiving side such as a vehicle body. The vibration isolator 10 mainly includes a shaft-shaped inner member 11 extending along an axis A1, a cylindrical outer member 12 extending along an axis A2 and surrounding the outer peripheral side of the inner member 11, and a vibration isolation base body 13 made of an elastic body for connecting them.

[0017] In the no-load state, the axis A1 and the axis A2 coincide. Hereinafter, the directions of the axis A1 and the axis A2 are simply referred to as the axial direction. The vibration isolator 10 is provided on the vehicle with the axial direction as the vertical direction. Further, each part of the vibration isolator 10 is formed symmetrically with respect to the axes A1 and A2.

[0018] The inner member 11 is a substantially cylindrical member surrounding the axis A1 and is composed of a rigid material such as a steel material or an aluminum alloy. The inner member 11 is fixed to one of the vibration source side and the vibration receiving side by a bolt inserted into the inner peripheral side.

[0019] A convex portion 11a bulging outward in the radial direction is formed at the central portion of the inner member 11 in the axial direction. The outer peripheral surface of the convex portion 11a is formed in a substantially spherical surface shape with a point on the axis A1 as the center C. This center C is located at the center of the axis A1 in the axial direction of the inner member 11. Further, the portions of the inner member 11 on both ends in the axial direction with respect to the convex portion 11a have outer peripheral surfaces formed in a substantially cylindrical surface shape centered on the axis A1. The inner peripheral surface of the inner member 11 is formed in a substantially cylindrical surface shape centered on the axis A1 over the entire length.

[0020] The outer member 12 is a substantially cylindrical member centered on the axis A2 and is composed of a rigid material such as a steel material or an aluminum alloy. The length of the outer member 12 in the axial direction is smaller than the length of the inner member 11 in the axial direction. The center of the outer member 12 in the axial direction coincides with the center of the inner member 11 in the axial direction. The outer member 12 is press-fitted and fixed inside a cylindrical bracket which is the other of the vibration source side and the vibration receiving side.

[0021] The outer member 12 has a reduced diameter portion 12a formed at both ends in the axial direction, which gradually decreases in diameter as it moves away from the axial center. This reduced diameter portion 12a is formed by drawing after the vibration-damping base 13 has been vulcanized. This reduced diameter portion 12a makes it easier to press-fit the outer member 12 into the bracket. In other words, even without chamfering at both ends in the axial direction of the outer member 12, the reduced diameter portion 12a ensures that the outer member 12 can be pressed into the bracket. Furthermore, the reduced diameter portion 12a can suppress deformation of the vibration-damping base 13 that would otherwise escape outward in the axial direction along the inner circumferential surface of the outer member 12.

[0022] The vibration-damping base 13 is made of an elastic material such as rubber or thermoplastic elastomer. The vibration-damping base 13 connects the outer circumferential surface of the inner member 11 to the inner circumferential surface of the outer member 12. The vibration-damping base 13 is a vulcanized molded product that is vulcanized within the cavity of a mold (not shown) in which the inner member 11 and the outer member 12 are set. During this vulcanization molding process, the vibration-damping base 13 is vulcanized and bonded to the outer circumferential surface of the inner member 11 and the inner circumferential surface of the outer member 12.

[0023] The vibration-damping base 13 has a first groove 14 and a second groove 15 that penetrate in the axial direction. The first groove 14 is located on the front side of the inner member 11 and extends in the circumferential direction. The second groove 15 is located on the rear side of the inner member 11 and extends in the circumferential direction. That is, the second groove 15 is located radially opposite to the first groove 14, with the inner member 11 in between.

[0024] The vibration-isolating base 13 includes a first outer surface 16 that forms the outer member 12 side of the inner wall of the first wedge 14, a first inner surface 17 that forms the inner member 11 side of the inner wall of the first wedge 14, a second outer surface 18 that forms the outer member 12 side of the inner wall of the second wedge 15, and a second inner surface 19 that forms the inner member 11 side of the inner wall of the second wedge 15.

[0025] These surfaces 16-19 (first cutout 14 and second cutout 15) are formed during the vulcanization molding of the vibration-damping base 13 using the mold described above. After vulcanization molding, in order to open the mold from the axial center to both sides and remove a portion of the mold from between the surfaces 16-19, it is necessary to provide a draft angle (for example, basically 1-2 degrees or more) in that portion of the mold. When the first outer surface 16 and the first inner surface 17 are formed with such a mold, the distance between the first outer surface 16 and the first inner surface 17 (the radial width of the first cutout 14) widens from the axial center toward both ends. The inclination angles of the first outer surface 16 and the first inner surface 17 with respect to axes A1 and A2 are approximately the same as the draft angle of the portion of the mold that forms them.

[0026] Similarly, due to the draft angle of the die, the distance between the second outer surface 18 and the second inner surface 19 (the radial width of the second gap 15) widens from the center in the axial direction toward both ends. The inclination angles of the second outer surface 18 and the second inner surface 19 with respect to axes A1 and A2 are approximately the same as the draft angle of the part of the die that forms them.

[0027] As shown in Figures 2 and 4, in this embodiment, the distance L1 between the first outer surface 16 and the first inner surface 17 at the axial center is set to 0.5 to 2.0 mm. That is, the first outer surface 16 and the first inner surface 17 are the parts on both radial sides of the first trim 14 where the distance L1 at the axial center is 0.5 to 2.0 mm. At both ends of the first trim 14 in the circumferential direction, the width is wider than the distance L1, but the sides of these parts are not the first outer surface 16 or the first inner surface 17.

[0028] When the inner member 11 is displaced forward relative to the outer member 12 due to a radial load input to the vibration isolation device 10, the first sill plate 14 collapses, causing the first outer surface 16 and the first inner surface 17 to come into contact, thereby restricting the deflection of the vibration isolation base 13 associated with this displacement. The timing for restricting the deflection when the first sill plate 14 collapses is set according to the value of the interval L1.

[0029] Furthermore, in this embodiment, the distance L2 between the second outer surface 18 and the second inner surface 19 at the axial center is set to 2.0 to 5.0 mm. That is, the portions on both radial sides of the second trim 15 where the distance L2 at the axial center is 2.0 to 5.0 mm are the second outer surface 18 and the second inner surface 19. At both ends of the second trim 15 in the circumferential direction, the width is wider than the distance L2, but the sides of these portions are not the second outer surface 18 or the second inner surface 19.

[0030] When the inner member 11 is displaced backward relative to the outer member 12 due to a radial load input to the vibration isolation device 10, the second sill 15 collapses, causing the second outer surface 18 and the second inner surface 19 to come into contact, thereby restricting the deflection of the vibration isolation base 13 associated with this displacement. The timing for restricting the deflection when the second sill 15 collapses is set according to the value of the interval L2.

[0031] Since the spacing L1 is narrower than the spacing L2, the timing for restricting the deflection when the first wedge 14 collapses can be set earlier, while the timing for restricting the deflection when the second wedge 15 collapses can be set later. For example, by positioning the vibration damping device 10 on the vehicle so that the first wedge 14 collapses due to the load during vehicle deceleration and the second wedge 15 collapses due to the load during vehicle acceleration, the timing for restricting the deflection of both can be set appropriately.

[0032] As shown in Figures 1 and 4, the first inner surface 17 is provided with a plurality of axial projections 17a that protrude toward the first outer surface 16. The plurality of axial projections 17a (grooves between the axial projections 17a) each extend linearly in the axial direction and are arranged along the circumferential direction of the first inner surface 17.

[0033] Similarly, the second inner surface 19 is provided with a plurality of axial projections 19a that protrude toward the second outer surface 18. The plurality of axial projections 19a (grooves between the axial projections 19a) each extend linearly in the axial direction and are arranged along the circumferential direction of the second inner surface 19.

[0034] As shown in Figures 2 and 3, the first outer surface 16 is provided with a plurality of circumferential protrusions 16a that project toward the first inner surface 17. The plurality of circumferential protrusions 16a (grooves between the circumferential protrusions 16a) each extend in the circumferential direction and are wavy in the axial direction, and are aligned along the axial direction of the first outer surface 16.

[0035] The second outer surface 18 is provided with a plurality of circumferential protrusions 18a that project toward the second inner surface 19. The plurality of circumferential protrusions 18a are formed in the same way as the plurality of circumferential protrusions 16a shown in Figure 3. That is, the plurality of circumferential protrusions 18a (grooves between the circumferential protrusions 18a) each extend in the circumferential direction and are wavy in the axial direction, and are aligned along the axial direction of the first outer surface 16.

[0036] The inclination angles of the first outer surface 16 and the second outer surface 18 with respect to axes A1 and A2 are the inclination angles of the surfaces that smoothly connect the tips of the multiple circumferential projections 16a and 18a. Similarly, the inclination angles of the first inner surface 17 and the second inner surface 19 with respect to axes A1 and A2 are the inclination angles of the surfaces that smoothly connect the tips of the multiple axial projections 17a and 19a.

[0037] As shown in Figures 2 and 4, when the first outer surface 16 and the first inner surface 17 come into contact, the tips of the multiple circumferential projections 16a and multiple axial projections 17a, which are oriented in different directions, first make point contact with each other. Subsequently, the circumferential projections 16a and axial projections 17a that are in contact with each other are crushed, and their contact area gradually expands. In this way, the contact between the first outer surface 16 and the first inner surface 17 is buffered, and the abnormal noise associated with the contact can be suppressed.

[0038] Furthermore, since the multiple circumferential projections 16a and multiple axial projections 17a extend in different directions, when they are compressed, the air in the grooves between the circumferential projections 16a and between the axial projections 17a can easily escape to the outside. In addition, when the first outer surface 16 and the first inner surface 17 separate again after contact, air can easily enter the grooves between the circumferential projections 16a and between the axial projections 17a, making it difficult for a vacuum to form. As a result, it is possible to suppress abnormal noises caused by the compression of air in the grooves and abnormal noises caused when air enters a vacuum-filled groove.

[0039] Similarly, when the second outer surface 18 and the second inner surface 19 come into contact, the tips of multiple circumferential projections 18a and multiple axial projections 19a, which are oriented in different directions, make point contact with each other. Then, as the circumferential projections 18a and axial projections 19a are compressed, the contact area gradually expands. As a result, noise associated with the contact between the second outer surface 18 and the second inner surface 19 can be suppressed by buffering the contact and suppressing the compression of air.

[0040] Furthermore, since the circumferential projections 16a and 18a extend in the circumferential direction while being wavy in the axial direction, when the axial projections 17a and 19a come into contact with them, if the contact position of the axial projections 17a and 19a shifts in the circumferential direction relative to the circumferential projections 16a and 18a, the contact position will also shift in the axial direction. This ease of contact position shifting suppresses localized wear on the circumferential projections 16a and 18a and the axial projections 17a and 19a compared to the case where the contact position does not shift easily.

[0041] Next, with reference to Figure 5, the vibration isolation device 10 during twisting deformation will be described. Figure 5 is a cross-sectional view of the vibration isolation device 10 during twisting deformation. Twisting deformation refers to the deformation of the vibration isolation base 13 by relatively rotating the inner member 11 and the outer member 12 around a radial axis passing through the center C. In particular, in this specification, the deformation of the vibration isolation base 13 when the inner member 11 is tilted relative to the outer member 12 in the directions of the first corner 14 and the second corner 15 (relatively rotated around a left-right axis) will be described as twisting deformation.

[0042] As shown in Figure 5, axes A1 and A2, which coincided in the unloaded state in Figure 2, shift around the center C due to twisting deformation. The angle of axis A1 with respect to axis A2 (the axial direction of the outer member 12) is the twisting angle θ.

[0043] As described above, in this embodiment, the vibration isolation device 10 has a gap L2 that is narrower than the gap L1. Therefore, during twisting deformation, the second outer surface 18 and the second inner surface 19 on both sides of the wider gap L2 are less likely to come into contact, but the first outer surface 16 and the first inner surface 17 on both sides of the narrower gap L1 are more likely to come into contact. This contact may generate abnormal noise.

[0044] For example, if each surface 16 to 19 is formed such that the draft angle from the mold (angle of inclination with respect to axes A1 and A2) is approximately 2 degrees, and the narrower gap L1 is 0.5 to 2.0 mm, there is a risk that the first outer surface 16 and the first inner surface 17 will come into contact when the twisting angle θ is approximately 15 degrees or less. However, there are cases where a specification is required in which the first outer surface 16 and the first inner surface 17 do not come into contact when the twisting angle θ is 17 degrees or less, while maintaining the gap L1 at 0.5 to 2.0 mm.

[0045] Therefore, in this embodiment, when the draft angle is approximately 2 degrees, both sides of the first inner surface 17 in the axial direction are machined. Specifically, the shapes of the first outer surface 16 and the first inner surface 17 are set so that they do not come into contact with each other when the twisting angle θ is 17 degrees or less. Thus, it is possible to make it difficult to generate abnormal noises due to contact between the first outer surface 16 and the first inner surface 17 during twisting deformation.

[0046] Returning to Figure 2, the shapes of the first outer surface 16 and the first inner surface 17 will be described in more detail. The first outer surface 16 is formed so as to be located outside or on a virtual cylindrical surface S1 with axes A1 and A2 as its central axis, with radius R1 being the radial distance from axes A1 and A2 to the axial center of the first outer surface 16 or the second outer surface 18. The second outer surface 18 is formed symmetrically to the first outer surface 16 with respect to axes A1 and A2, and is formed so as to be located outside or on a virtual cylindrical surface S1.

[0047] Furthermore, a virtual spherical surface S2 with center C is defined, having the same radius R2 as the radius R1 of the virtual cylindrical surface S1. The first inner surface 17 is formed to be located inside this spherical surface S2. Similarly, the second inner surface 19 is also formed to be located inside the virtual spherical surface S2.

[0048] As a result, during simple twisting deformation (when only twisting deformation occurs in the vibration-damping base 13), the first inner surface 17 and the second inner surface 19 move around the center C of the virtual spherical surface S2, and therefore do not extend outward from the virtual spherical surface S2. This prevents the first outer surface 16 and the first inner surface 17, and the second outer surface 18 and the second inner surface 19 from coming into contact during simple twisting deformation. Therefore, it is possible to make it less likely for abnormal noises to be generated during twisting deformation due to contact between them.

[0049] Both the first inner surface 17 and the second inner surface 19 are formed so that they gradually approach the spherical surface S2 as they move from the axial center (positions L1 and L2) toward both sides in the axial direction, and then move away from the spherical surface S2 along the way. That is, the inclination angles of the first inner surface 17 and the second inner surface 19 with respect to axes A1 and A2 are relatively small near the axial center and relatively large on both sides in the axial direction. As a result, when a load is applied in the longitudinal direction, the small inclination angle near the axial center allows for an early widening of the contact area from the start of contact between the first outer surface 16 and the first inner surface 17, and from the start of contact between the second outer surface 18 and the second inner surface 19. Consequently, the deflection of the vibration-damping base 13 in response to a load applied in the longitudinal direction can be restricted early from the start of contact.

[0050] Furthermore, the vibration-damping base 13 is provided with a stopper portion 13a to restrict excessive twisting deformation. The stopper portion 13a is a rectangular parallelepiped-shaped portion located axially outside the outer member 12 (between the first outer surface 16 and the first inner surface 17) and positioned in front of the outer circumferential surface of the inner member 11. The stopper portion 13a is set to contact the first outer surface 16 when the twisting angle θ becomes a predetermined value greater than 17 degrees (for example, 30 degrees). This contact can restrict excessive twisting deformation where the twisting angle θ exceeds the predetermined value, thereby improving the durability of the vibration-damping base 13.

[0051] In the axial central cross-section shown in Figure 4, a pair of imaginary lines V1 are defined that pass through both ends in the circumferential direction of the opposing portions of the first outer surface 16 and the first inner surface 17 (the first slit 14 excluding the wide portion) and axes A1 and A2, respectively. In the axial central cross-section, it is preferable that the area of ​​the vibration-isolating base 13, excluding the first slit 14, in the area inside the pair of imaginary lines V1 (the area obtained by projecting the opposing portions of the first outer surface 16 and the first inner surface 17 radially) between the inner member 11 and the outer member 12 is 60% or more. That is, it is preferable that the area of ​​the first slit 14 is less than 40%.

[0052] In this embodiment, when the draft angle is approximately 2 degrees, the volume of the vibration-damping base 13 between the first sill 14 and the inner member 11 is reduced by machining both sides of the first inner surface 17 in the axial direction. If this volume is reduced too much, when the inner member 11 is displaced forward relative to the outer member 12 due to a radial load input that crushes the first sill 14, the displacement becomes difficult to control. This can lead to excessive deformation of the vibration-damping base 13, potentially worsening its durability. In contrast, by ensuring that the area of ​​the vibration-damping base 13 in the above range is 60% or more in the cross-section at the center in the axial direction, excessive deformation of the vibration-damping base 13 can be suppressed when a radial load input crushes the first sill 14, thereby ensuring the durability of the vibration-damping base 13.

[0053] Furthermore, in the cross-section at the center in the axial direction, a pair of imaginary lines V2 are set that pass through both ends in the circumferential direction of the opposing portions of the second outer surface 18 and the second inner surface 19 (the second slit 15 excluding the wide portion) and through the axes A1 and A2. In the cross-section at the center in the axial direction, it is preferable that the area of ​​the vibration-isolating base 13, excluding the second slit 15, in the area inside the pair of imaginary lines V2 (the area obtained by projecting the opposing portions of the second outer surface 18 and the second inner surface 19 radially) between the inner member 11 and the outer member 12 is 60% or more. That is, it is preferable that the area of ​​the second slit 15 is less than 40%. In this case, similar to the first slit 14 side described above, excessive deformation of the vibration-isolating base 13 can be suppressed when a radial load is applied that crushes the second slit 15, and the durability of the vibration-isolating base 13 can be ensured.

[0054] Next, a second embodiment will be described with reference to Figures 6 and 7. In the first embodiment, a case was described in which circumferential projections 16a and 18a are provided on the first outer surface 16 and the second outer surface 18, respectively, and axial projections 17a and 19a are provided on the first inner surface 17 and the second inner surface 19, respectively. In contrast, the second embodiment will describe a case in which these projections are arranged in the opposite direction. Note that parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted below.

[0055] Figure 6 is a cross-sectional view of the vibration isolation device 30 in the second embodiment. Figure 7 is a cross-sectional view of the vibration isolation device 30 along the line VII-VII in Figure 6. The vibration isolation device 30 is modified from the vibration isolation device 10 in the first embodiment by providing an axial projection 31 on the first outer surface 16 in place of the circumferential projection 16a, and an axial projection 33 on the second outer surface 18 in place of the circumferential projection 18a.

[0056] In addition, the vibration isolation device 30 differs from the vibration isolation device 10 of the first embodiment in that a circumferential projection 32 is provided on the first inner surface 17 in place of the axial projection 17a, and a circumferential projection 34 is provided on the second inner surface 19 in place of the axial projection 19a. The configuration of the vibration isolation device 30 other than these is the same as that of the vibration isolation device 10 of the first embodiment.

[0057] The axial projection 31 is a projection that protrudes from the first outer surface 16 toward the first inner surface 17 and extends linearly in the axial direction. Multiple axial projections 31 are arranged along the circumferential direction of the first outer surface 16. The axial projection 33 is a projection that protrudes from the second outer surface 18 toward the second inner surface 19 and extends linearly in the axial direction. Multiple axial projections 33 are arranged along the circumferential direction of the second outer surface 18.

[0058] The circumferential projections 32 are projections that extend from the first inner surface 17 toward the first outer surface 16, and are wavy in the axial direction while extending in the circumferential direction. Multiple circumferential projections 32 are arranged along the axial direction of the first inner surface 17. The circumferential projections 34 are projections that extend from the second inner surface 19 toward the second outer surface 18, and are wavy in the axial direction while extending in the circumferential direction. Multiple circumferential projections 34 are arranged along the axial direction of the second inner surface 19.

[0059] As described above, the vibration isolation device 30 has the arrangement of the axial projections 31, 33 and the circumferential projections 32, 34 reversed compared to the first embodiment, and basically produces substantially the same effects as the vibration isolation device 10 of the first embodiment. However, the new effects obtained by reversing the arrangement will be explained below.

[0060] When manufacturing the vibration-damping base 13 using a mold that opens to both sides from the axial center, the multiple circumferential protrusions 32, 34 that extend in the circumferential direction and are aligned in the axial direction are formed by forced cutting. The first inner surface 17 and the second inner surface 19 on which these circumferential protrusions 32, 34 are provided are located inside the virtual spherical surface S2, after the spacing L1, L2 between them and the first outer surface 16 and the second outer surface 18 at the axial center has been determined.

[0061] Therefore, the first inner surface 17 and the second inner surface 19 are more inclined with respect to axes A1 and A2 as they move away from the axial center than the first outer surface 16 and the second outer surface 18. Since the circumferential protrusions 32 and 34 formed by forced extraction are provided on the first inner surface 17 and the second inner surface 19, which have a greater inclination, rather than the first outer surface 16 and the second outer surface 18, which have a smaller inclination, the force required during forced extraction can be reduced. Thus, the workability when removing the vibration-damping base 13 from the mold can be improved.

[0062] Although the present invention has been described above based on embodiments, it can be easily inferred that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention.

[0063] For example, the shapes, materials, and numerical values ​​listed in each of the above embodiments are merely examples, and it is naturally possible to use other shapes, materials, and numerical values. The vibration isolation devices 10 and 30 may be asymmetrical. Also, the circumferential projections 16a, 18a, 32, 34 and the axial projections 17a, 19a, 31, 33 may be omitted.

[0064] The inner member 11 is not limited to a cylindrical shape; it may also be a rod shape with the inner circumference hole omitted. The outer surface of the inner member 11 is not limited to having a roughly circular cross-section perpendicular to the axis A1; it may also be elliptical or polygonal. The convex portion 11a of the inner member 11 may be omitted, and a part of the outer surface of the inner member 11 may be recessed. The outer member 12 is not limited to a cylindrical shape; it may also be elliptical or polygonal, and a part of it in the axial direction may be bulging or recessed. The reduced diameter portion 12a may also be omitted.

[0065] In the above embodiment, the case in which the vibration damping devices 10 and 30 are mounted on a vehicle with their axial direction being vertical was described, but this is not necessarily the only case. The vibration damping devices 10 and 30 may be mounted on something other than a vehicle. Furthermore, the vibration damping devices 10 and 30 may be arranged so that their axial direction is in the front-rear or left-right direction of the vehicle or other object. [Explanation of Symbols]

[0066] 10,30 Vibration Isolator 11. Inner side components 12. Outer Components 13 Anti-vibration matrix 14 No. 1 すぐり 15 No. 2 すぐり 16 First outer surface 16a, 18a, 32, 34 Surrounding protrusions 17. First inner surface 17a, 19a, 31, 33 Axial extension protrusions 18 Second outer surface 19 Second inner surface A1, A2 axes L1, L2 interval S1 cylindrical surface S2 Sphere

Claims

1. An axial inner member extending along the axis, A cylindrical outer member surrounding the outer circumference of the inner member, The system comprises an elastic vibration-damping base connecting the outer circumferential surface of the inner member and the inner circumferential surface of the outer member, The vibration-damping base is, A first rib that penetrates in the axial direction, A second pass is positioned on the radially opposite side of the first pass and penetrates axially, sandwiching the inner member between them, The first outer surface of the inner wall of the first side that forms the side of the outer member, The first inner surface of the first inner wall forms the inner member side, and the distance between it and the first outer surface at the center in the axial direction is set to 0.5 to 2.0 mm, The second outer surface of the inner wall of the second side, which forms the side of the outer member, The second inner wall of the second inner wall comprises a second inner surface which forms the inner member side and is set to a distance of 2.0 to 5.0 mm from the second outer surface at the center in the axial direction, A vibration isolation device characterized in that, when the vibration isolation base is twisted and deformed by tilting the inner member relative to the outer member in the direction of the first and second edges, the shapes of the first outer surface and the first inner surface are set such that the twisting angle of the axis of the inner member with respect to the axial direction of the outer member is 17 degrees or less and the first outer surface and the first inner surface are not in contact.

2. The first outer surface and the second outer surface are located outside or on the cylindrical surface of a virtual cylindrical surface with the axis as its central axis, with the radius being the radial distance from the axis to the center of the first outer surface or the second outer surface in the axial direction. The vibration isolation device according to claim 1, characterized in that the first inner surface and the second inner surface are located inside a virtual spherical surface having the same radius as the virtual cylindrical surface, with the center of the axis in the axial direction of the inner member as the center of the axis.

3. On the first outer surface and the second outer surface, a plurality of axially extending protrusions are arranged circumferentially, respectively. The vibration isolation device according to claim 2, characterized in that a plurality of circumferential projections extending in the circumferential direction are arranged along the axial direction on the first inner surface and the second inner surface, respectively.

4. In a cross-section including the axial center of the first outer surface and the first inner surface, the area of ​​the vibration-damping base excluding the first edge in the range projected radially from the portion between the inner member and the outer member where the first inner surface and the first outer surface face each other is 60% or more, The vibration isolation device according to any one of claims 1 to 3, characterized in that, in a cross-section including the axial center of the second outer surface and the second inner surface, the area of ​​the vibration isolation base excluding the second curb in the range projected radially from the portion between the second inner surface and the second outer surface, out of the space between the inner member and the outer member, is 60% or more.

Images