JP2012211604A - Vibration-isolating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-isolating device capable of reducing the spring constant in the prying direction and improving the durability while ensuring the spring constant in the direction orthogonal to the axis.SOLUTION: A concave part 33 of an outer cylinder 30 in a first bush 10 and a second bush 70 is formed in a continuously spherical shape, and opposite to a convex part 24 of a shaft member 20. Thus, the wall thickness of a rubber-like elastic body 40 interposed between the concave part 33 and the convex part 24 can be substantially constant in the axial direction. As a result, exertion of any non-uniform stress in the rubber-like elastic body 40 can be controlled during the displacement in the prying direction or in the direction orthogonal to the axis, and the durability of a vibration-isolating device 1 can be enhanced. During the displacement in the direction orthogonal to the axis, any movement in the axial direction of the rubber-like elastic body 40 is prevented, and the spring constant in the direction orthogonal to the axis can be ensured. Further, during the displacement in the prying direction, the rubber-like elastic body 40 is mainly subjected to the shear deformation, and the spring constant in the prying direction can be reduced.

Description

  The present invention relates to an anti-vibration device in which the vibration generating side and the vibration receiving side are anti-vibrated and connected to each other, and in particular, while ensuring the spring constant in the direction perpendicular to the axis, the spring constant in the twisting direction can be reduced and the durability can be reduced. The present invention relates to a vibration isolator that can be improved.

  Conventionally, vibration isolators such as torque rods and suspension arms that mutually connect the vibration generation side and the vibration receiving side with vibration isolation have been widely used. Such an anti-vibration device is generally configured by connecting anti-vibration bushes including a shaft member such as an inner cylinder and an outer cylinder elastically coupled to the shaft member to each other by a connecting member.

  As such an anti-vibration device, a device disclosed in Patent Document 1 connects a large-diameter anti-vibration bush (large bush) and a small-diameter anti-vibration bush (small bush) by a connecting member. Hereinafter, a conventional vibration isolator 200 disclosed in Patent Document 1 will be described with reference to FIG. FIG. 8 is a sectional view in the axial direction of a small bush 210 in the conventional vibration isolator 200. The small bush 210 in the vibration isolator 200 is for increasing the spring constant in the direction perpendicular to the axis (arrow P1 direction) and reducing the spring constant in the twisting direction (arrow P2 direction).

  As shown in FIG. 8, the small bushing 210 of the vibration isolator 200 is formed as a convex curved surface 212 by bulging the axial center portion of the shaft member 211 outward in the direction perpendicular to the axis. The outer cylinder 213 includes a pair of half bodies 213a and 213b that are divided into two in the axial direction at the central portion in the axial direction. Further, the connecting member 214 that connects the small bush 210 and the large bush (not shown) is configured by overlapping a pair of plate bodies 214a and 214b. The half bodies 213a and 213b and the plate bodies 214a and 214b are integrally formed, and the pair of half bodies 213a and 213b, the plate bodies 214a and 214b, and the shaft member 211 are vulcanized and bonded by a rubber-like elastic body 215. Yes.

  The outer cylinder 213 has a concave curved surface that curves outward in the direction perpendicular to the axis by a pair of halves 213a and 213b, is opposed to the convex curved surface 212, and the space between the shaft member 211 and the outer cylinder 213 is rubbery. It is connected with an elastic body. Note that the large bush of the vibration isolator 200 has a shaft member and an outer cylinder that are formed in a cylindrical shape, and the convex curved surface 212 and the concave curved surface are not formed as in the small bush 210, so that illustration is omitted. .

JP 2005-344664 A

  However, in the technique disclosed in Patent Document 1, the large bush (not shown) has a different shape from the small bush, and the convex curved surface 212 and the concave curved surface are not formed like the small bush 210. Therefore, when the vibration isolator 200 is used, the strain of the rubber-like elastic body of either the large bush or the small bush 210 (particularly the large bush) increases. As a result, the lifetime of the rubber-like elastic body on the larger strain side comes to be extremely early, and it is difficult to improve the durability of the vibration isolator 200.

  Moreover, since the outer cylinder 213 in the small bush 210 is divided into two in the axial direction at the central part in the axial direction, the concave curved surface of the outer cylinder 213 is divided at the central part in the axial direction. Therefore, the concave curved surface of the outer cylinder 213 cannot be a continuous surface in the axial direction. Therefore, the rubber-like elastic body 215 interposed between the concave curved surface and the convex curved surface 212 has a non-uniform thickness in the axial direction. As a result, non-uniform stress acts on the rubber-like elastic body 215 interposed between the convex curved surface 212 and the concave curved surface during displacement in the twisting direction (arrow P2 direction) or the axis perpendicular direction (arrow P1 direction). There is a problem that the durability of the vibration isolator 200 is lowered.

  Further, the rubber-like elastic body 215 existing between the divided outer cylinder 213 and the convex curved surface 212 is integrated with the rubber-like elastic body 215 interposed between the plate bodies 214 a and 214 b of the connecting member 214. Yes. Therefore, the thickness of the rubber-like elastic body 215 interposed between the outer cylinder 213 and the convex curved surface 212 is set between the plates 214a and 214b of the connecting member 214 from which the outer cylinder 213 is divided (the axis of the inner cylinder 211). Thicker in the middle). When the thickness of the rubber-like elastic body 215 is increased at the portion where the outer cylinder 213 is divided, there is a problem that the spring constant in the direction perpendicular to the axis (the direction of the arrow P1) decreases.

  Further, in order to prevent the spring constant in the direction perpendicular to the axis (the direction of the arrow P1) from being lowered, when the rubber-like elastic body 215 having a large rigidity is employed, the spring constant in the direction perpendicular to the axis is improved. There is a problem in that the spring constant in the direction (arrow P2 direction) increases.

  The present invention has been made to solve the above-described problems, and provides a vibration isolator capable of reducing the spring constant in the twisting direction and improving the durability while securing the spring constant in the direction perpendicular to the axis. It is an object.

Means for Solving the Problems and Effects of the Invention

  In order to achieve this object, according to the vibration isolator of claim 1, the first bush attached to the vibration generating side, the second bush attached to the vibration receiving side, the first bush, The first bush and the second bush are formed in a cylindrical shape, the central portion in the axial direction bulges outward in the direction perpendicular to the axis, and the outer peripheral surface is a spherical surface. A shaft member having a convex portion formed in a shape, and being connected to the connecting member on the outer peripheral side of the shaft member in parallel with the shaft member, and having a central portion in the axial direction perpendicular to the convex portion. And an outer cylinder having a concave surface portion that is formed in a spherical shape having a continuous inner peripheral surface while being depressed outward, and the convex portion and the concave surface portion are provided on the shaft member and the outer cylinder in the first bush and the second bush. It is formed. Since the concave surface portion of the outer cylinder is formed in a continuous spherical shape and faces the convex surface portion of the shaft member, the rubber-like elastic body interposed between the concave surface portion and the convex surface portion is substantially thin in the axial direction. Can be constant. As a result, it is possible to suppress non-uniform stress from acting on the rubber-like elastic body interposed between the concave surface portion and the convex surface portion during displacement in the twisting direction or the direction perpendicular to the axis. Thereby, there exists an effect which can improve the durability of a vibration isolator.

  Further, when the vibration isolator is used, it is possible to suppress the distortion of the rubber-like elastic body in the first bush and the second bush from being significantly different. As a result, it is possible to suppress the life of the rubber-like elastic body of one of the first bush and the second bush from reaching extremely early and to improve the durability of the vibration isolator.

  Also, during displacement in the direction perpendicular to the axis, the axial movement of the rubber-like elastic body interposed between the concave and convex portions is hindered by the concave and convex portions, so a spring constant in the direction perpendicular to the axis is ensured. There is an effect that can be done. At the time of displacement in the axial direction, the rubber-like elastic body between the convex surface portion and the concave surface portion undergoes shear deformation and compression deformation, thereby ensuring a spring constant in the axial direction.

  Further, at the time of displacement in the twisting direction, the rubber-like elastic body interposed between the convex surface portion and the concave surface portion is mainly subjected to shear deformation, so that the axial end portion of the rubber-like elastic body is between the shaft member and the outer cylinder. Can be suppressed from being compressed and deformed. As a result, the spring constant in the twisting direction can be reduced.

  If the spring constant in the twisting direction of the first bush and the second bush can be reduced, the angle of the displaceable displacement between the vibration generating side and the vibration receiving side can be increased. By increasing the angle of displacement that can be absorbed, the connecting member that connects the first bush and the second bush can be shortened when the magnitude (distance) of the displacement is the same. If the connecting member can be shortened, the mass of the connecting member (including the masses of the outer cylinders of the first bush and the second bush) can be reduced, and the resonance frequency of the connecting member can be increased under the condition that the spring constant is not changed. As described above, there is an effect that the vibration damping characteristics of the vibration isolator can be controlled by reducing the spring constant in the twisting direction of the first bush and the second bush.

  According to the vibration isolator of claim 2, the connecting member is formed in a cylindrical shape, and the first cylindrical holder and the second cylindrical holder into which the outer cylinders of the first bush and the second bush are respectively press-fitted. The second bushing is provided at both ends, and the second bushing is configured by a member having the same shape and the same size as the first bushing and is set to the same spring constant, so that the second bushing and the first bushing can be shared, In addition to the effect of item 1, the number of parts can be reduced. Further, since the second bush and the first bush can be used in common, the procedure and method of press-fitting work of the first bush and the second bush can be simplified, and the effect of improving the productivity of the vibration isolator can be achieved. is there.

  In addition, since the first bush and the second bush are made of members having the same shape and the same dimensions and are set to the same spring constant, the durability of the vibration isolator can be improved. That is, when the spring constants of the first bush and the second bush are set differently, the rubber-like elastic body having a small spring constant is greatly distorted. It was difficult to improve durability. On the other hand, by setting the spring constants of the first bush and the second bush to the same setting, it is possible to suppress an increase in the load of one rubber-like elastic body and improve the durability of the vibration isolator. There is an effect that can be done.

  According to the vibration isolator of the third aspect, since the rubber-like elastic body includes the recessed portion that is recessed in part of the axial end surfaces of the first bush and the second bush, The spring constant of the rubber-like elastic body in the direction perpendicular to the axis of a part of the two bushes can be made smaller than the spring constant of the rubber-like elastic body in the other direction perpendicular to the axis. As a result, in addition to the effect of claim 1 or 2, when high-frequency and small-amplitude vibration is input in the direction of a part of the first bush and the second bush of the vibration isolator, vibration transmission to the vibration receiving side is performed. There is an effect that can be suppressed.

  According to the vibration isolator of claim 4, the concave portion includes an arc portion whose axial cross section is formed in an arc shape, and a virtual spherical surface defined by the concave surface portion intersects the concave portion, and the arc portion is Since it is located inside the phantom spherical surface, it is possible to reliably avoid the axial end portion of the rubber-like elastic body from being compressed and deformed between the shaft member and the outer cylinder at the time of displacement in the twisting direction. Thereby, in addition to the effect of Claim 3, there is an effect that the spring constant in the twisting direction can be further reduced.

It is a top view of the vibration isolator in 1st Embodiment. (A) is a top view of a 1st bush, (b) is sectional drawing of the 1st bush in the IIb-IIb line | wire of Fig.2 (a). It is the elements on larger scale of the 1st bush which expanded and showed the portion shown by III of Drawing 2 (b). It is a schematic diagram which shows the relationship between the angle and magnitude | size of the displacement in the prying direction of a 1st bush and a 2nd bush, and the length of a connection member. It is a top view of the vibration isolator in 2nd Embodiment. (A) is a top view of a 1st bush, (b) is sectional drawing of the 1st bush in the VIb-VIb line | wire of Fig.6 (a). It is the elements on larger scale of the 1st bush which expanded and showed the part shown by VII of FIG.6 (b). It is an axial sectional view of a small bush in a conventional vibration isolator.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a plan view of a vibration isolator 1 according to the first embodiment of the present invention. In FIG. 1, a torque rod for an automobile is shown.

  As shown in FIG. 1, the vibration isolator 1 is attached to a first bush 10 attached to a power plant side (vibration generating side) such as an engine (not shown) and a vehicle body side (vibration receiving side) not shown. The second bushing 70 and a connecting member 80 for connecting the first bushing 10 and the second bushing 70 to each other are provided, and are configured to be able to regulate displacement in the roll direction of the power plant and displacement in the front-rear direction during acceleration. Has been.

  As shown in FIG. 1, the first bush 10 includes a shaft member 20 attached to the power plant side, an outer cylinder 30 arranged coaxially with the shaft member 20 on the outer peripheral side of the shaft member 20, and a shaft member. 20 and a cylindrical rubber-like elastic body 40 interposed between the outer cylinder 30 and the outer cylinder 30. The second bush 70 is composed of members having the same shape and the same dimensions as the first bush 10 and is set to the same spring constant. Therefore, the first bush 10 will be described, and the description of the second bush 70 will be omitted.

  The shaft member 20 is a metal cylindrical member, and a fastening member such as a bolt is inserted into an insertion hole 21 formed in the center, and is fastened and fixed to the power plant side. The outer cylinder 30 is a metal cylindrical member, and is arranged in parallel with the shaft member 20. The shaft member 20 and the outer cylinder 30 are connected by a rubber-like elastic body 40 over the entire circumference.

  The rubber-like elastic body 40 is a cylindrical member made of a rubber-like elastic material, and an annular straight portion 41 (see FIG. 2B) is recessed in the circumferential direction of the axial end face. The rubber-like elastic body 40 is formed with a recessed portion 42 that is connected to the inner side in the axial direction of the straight portion 41 at a position sandwiching the shaft member 20.

  The connecting member 80 is a member for connecting the first bush 10 and the second bush 70, and the first cylindrical holder 81 and the second cylindrical holder 82 formed in a cylindrical shape are formed in a rod shape. The rod part 83 is connected to both ends. When the outer cylinder 30 of the first bush 10 and the second bush 70 is press-fitted into the first cylindrical holder 81 and the second cylindrical holder 82, the first bush 10 and the second bush 70 are connected to each other. In the present embodiment, the first cylindrical holder 81 and the second cylindrical holder 82 and the rod portion 83 are joined by welding, and the first cylindrical holder 81 and the second cylindrical holder 82 are arranged in parallel to the axis. Yes. In addition, it is not restricted to what joins the 1st cylindrical holder 81 and the 2nd cylindrical holder 82, and the rod part 83 by welding, The 1st cylindrical holder 81, the 2nd cylindrical holder 82, the rod part 83, and Of course, it is possible to adopt a structure in which is integrally formed.

  The direction in which the first bush 10 and the second bush 70 are press-fitted into the first cylindrical holder 81 and the second cylindrical holder 82 (angle around the axis C) is formed on the axial end surface of the rubber elastic body 40. The recessed portion 42 is set so as to come to a position that intersects the virtual straight line A along the connecting direction of the first bush 10 and the second bush 70.

  Next, the first bush 10 will be described with reference to FIGS. 2 and 3. 2A is a plan view of the first bush 10, FIG. 2B is a cross-sectional view of the first bush 10 taken along the line IIb-IIb of FIG. 2A, and FIG. It is the elements on larger scale of the 1st bush 10 which expanded and showed the part shown by III. 2B and 3, the arrow X indicates the axial direction, the arrow Y indicates the direction perpendicular to the axis, the arrow Z indicates the twisting direction, and the arrow N indicates the twisting direction.

  As shown in FIG. 2A, the first bush 10 includes a shaft member 20, an outer cylinder 30 arranged coaxially with the shaft member 20 on the outer peripheral side of the shaft member 20, and the shaft member 20 and the outer cylinder 30. And a cylindrical rubber-like elastic body 40 interposed therebetween.

  As shown in FIG. 2 (b), the shaft member 20 has an insertion hole 21 formed through the end surface in the axial direction at the center, and the outer peripheral surface 22 is pivoted from the axial end to the inner side in the axial direction. An inclined portion 22a that is inclined inward in the perpendicular direction is formed over the entire circumference. The reduced diameter portion 23 is a portion continuously provided on the inner side in the axial direction of the inclined portion 22a, and is a cylindrical surface formed by reducing the diameter inward in the direction perpendicular to the axis by the amount of the inclined portion 22a with respect to the outer diameter of the outer peripheral surface 22. It is. The shaft member 20 includes a convex surface portion 24 that bulges over the entire circumference in the center portion of the axial direction X in the direction perpendicular to the axial direction Y and has a spherical outer peripheral surface. The convex surface portion 24 forms a convex spherical surface (virtual spherical surface E, see FIG. 3), is formed in a spherical shape having a center P on the axis C, and is formed continuously continuously from the reduced diameter portion 23. .

  The outer cylinder 30 is formed in a cylindrical shape whose outer shape has a circular cross section and whose outer peripheral surface 31 has a constant diameter in the axial direction X. In addition, a concave surface portion 33 is formed on the inner peripheral surface 32 of the outer cylinder 30 so as to bend and bend outward in the direction perpendicular to the axis from the axial end to the inner side in the axial direction. The concave surface portion 33 is formed so as to be opposed to the convex surface portion 24, and the central portion in the axial direction X is concentric with the convex surface portion 24 (that is, has a common center P). 3). More specifically, in the shape after drawing, which will be described later, the outer cylinder 30 is formed as a concave spherical surface that is recessed outwardly in the direction perpendicular to the axis Y so as to follow the convex portion 24 of the shaft member 20 with a certain interval. A concave surface portion 33 is formed at the central portion in the axial direction X. The concave surface portion 33 is formed in a spherical band shape having a center P on the axis C, and is formed continuously continuously from the cylindrical inner peripheral surface 32 at the axial end portion of the outer cylinder 30.

  In the state before the drawing of the outer cylinder 30, the concave surface portion 33 is not a strict concave spherical surface, and the center P is located at a position shifted from the axis C of the outer cylinder to the outside in the direction perpendicular to the axis Y. The center P is formed into a spherical band located on the axis C by drawing in the direction.

  In the outer cylinder 30, the concave portion 33 is provided in the central portion in the axial direction X of the inner peripheral surface 32, so that the thickness at the central portion in the axial direction X is thinner than the thickness at both end portions in the axial direction X. It is formed. Thereby, the diameter of the outer peripheral surface 31 of the outer cylinder 30 can be made constant over the axial direction X. As a result, a sufficient axial dimension for press-fitting can be ensured between the first cylindrical holder 81 and the second cylindrical holder 82 (see FIG. 1). The removal force from the cylindrical holder 82 can be improved.

  A plurality of concave grooves (not shown) extending in the axial direction X are formed at equal intervals in the circumferential direction on the inner peripheral surface 32 of the outer cylinder 30. Thereby, the thickness of the outer cylinder 30 in the position in which the ditch | groove was formed can be made thin compared with the thickness of the outer cylinder 30 between ditch | grooves. Since the concave groove is formed in the circumferential direction of the outer cylinder 30, when the outer cylinder 30 is drawn by inserting the rubber-like elastic body 40 between the shaft member 20 and the outer cylinder 30, the outer cylinder 30 is The diameter can be easily reduced. Thereby, the workability of drawing can be improved. Furthermore, a compressive stress can be applied to the rubber-like elastic body 40 by applying a restriction to the outer cylinder 30 and reducing the diameter, and the life of the rubber-like elastic body 40 can be improved.

  The rubber-like elastic body 40 is a member interposed between the convex surface portion 24 of the shaft member 20 and the concave surface portion 33 of the outer cylinder 30, and is integrally vulcanized and bonded to the outer cylinder 30 and the shaft member 20. Yes. The rubber-like elastic body 40 is formed in a spherical band shape having a substantially constant thickness between the convex surface portion 24 and the concave surface portion 33 in the shape after the drawing of the outer cylinder 30. In addition, the rubber-like elastic body 40 has an annular straight portion 41 that is recessed inward in the axial direction in the circumferential direction of the axial end face. The straight portion 41 is a part for preventing the rubber-like elastic body 40 from being filled between the shaft member 20 and the outer cylinder 30 and has an axial cross section formed in an arc shape. At two locations in the circumferential direction of the straight portion 41, concave portions 42 that extend inward in the axial direction and have an arc-shaped cross section in the axial direction are formed.

  The outermost diameter of the convex surface portion 24 of the shaft member 20 (the outer diameter at the apex of the convex surface portion 24) is set smaller than the inner diameter of the inner peripheral surface 32 of the outer cylinder 30, and the convex surface portion 24 and the concave surface portion 33. The thickness of the rubber-like elastic body 40 therebetween is set to be larger than the maximum bulging height of the convex surface portion 24 with respect to the reduced diameter portion 23. Accordingly, the spring constants in the direction perpendicular to the axis Y, the twisting direction Z, and the torsional direction N can be optimally set while avoiding an excessive spring constant in the axial direction X.

  As shown in FIG. 3, a rubber film 43 that continues from the rubber-like elastic body 40 is formed between the straight portion 41 and the recessed portion 42 and the shaft member 20. The rubber film 43 is formed over the entire surface of the inclined portion 22 a and the reduced diameter portion 23, and the outer peripheral surface of the rubber film 43 is located on the same plane as the outer peripheral surface 22 of the shaft member 20. Since the rubber film 43 is formed on the surfaces of the inclined portion 22a and the reduced diameter portion 23, the bonding area between the rubber-like elastic body 40 and the shaft member 20 can be increased, and the bonding strength can be improved.

  On the other hand, a rubber film 44 continuous from the rubber-like elastic body 40 is formed between the straight portion 41 and the recessed portion 42 and the outer cylinder 30. Since the rubber films 43 and 44 are formed on the shaft member 20 and the outer cylinder 30, the rubber films 43 and 44 come into contact with each other when a large vibration in the twisting direction Z is input, and the shaft member 20 and the outer cylinder 30. The relative displacement can be restricted, and the collision sound when abutting can be suppressed. Moreover, since the thickness of the rubber film 43 can be increased by forming the rubber film 43 on the surfaces of the inclined portion 22a and the reduced diameter portion 23, the impact noise suppression effect can be increased and the strength of the rubber film 43 can be improved. .

  In the axial cross section of the rubber-like elastic body 40, the phantom spherical surface F defined by the concave surface portion 33 intersects the concave portion 42 at the intersection point G and intersects the straight portion 41 at the intersection point H. The intersection H is located closer to the outer cylinder 30 than the innermost point J in the straight portion 41 (that is, the point corresponding to the deepest portion (bottom) of the straight portion 41). Thereby, at the time of displacement in the twisting direction Z, it can be avoided that the axial end portion of the rubber-like elastic body 40 is compressed and deformed between the shaft member 20 and the outer cylinder 30. Thereby, the spring constant in the twisting direction Z can be reduced.

  The recessed portion 42 includes an arc portion 42a that is connected to the rubber film 44 and has an axial section formed in an arc shape. The intersection point G between the phantom spherical surface F and the recessed portion 42 defined by the concave surface portion 33 is located at the root of the rubber film 44 of the circular arc portion 42a, and the circular arc portion 42a is located inside the virtual spherical surface F (center P side, FIG. ))).

  As described above, the rubber-like elastic body 40 is provided with the recessed portion 42 that is continuously provided on the inner side in the axial direction of the straight portion 41. Therefore, the direction perpendicular to the axis Y in which the recessed portion 42 is formed (FIG. 2 (a) left-right direction). The spring constant of the rubber-like elastic body 40 in () can be made smaller than the spring constant in the other direction perpendicular to the axis Y (vertical direction in FIG. 2 (a)). As a result, vibration transmission when high-frequency and small-amplitude vibration is input in this direction can be suppressed.

  Moreover, since the virtual spherical surface F defined by the concave surface portion 33 intersects the concave portion 42 at the intersection point G, and the arc portion 42a of the concave portion 42 is located inside the virtual spherical surface F, the concave portion 42 is formed. When the axial cross section is displaced in the twisting direction Z, it is possible to reliably avoid compressive deformation of the axial end portion of the rubber-like elastic body 40 between the shaft member 20 and the outer cylinder 30. Thereby, the spring constant in the twisting direction Z can be further reduced in the plane in which the recessed portion 42 is formed.

  Here, in order to manufacture the first bush 10, first, the shaft member 20 and the outer cylinder 30 are respectively formed and then placed in a molding die (not shown). Next, the rubber-like elastic body 40 is vulcanized and molded by injecting a molding material such as a rubber material into the mold, and the rubber-like elastic body 40 is integrally added between the shaft member 20 and the outer cylinder 30. By vulcanization bonding, a vulcanized molded body before drawing is obtained. Next, the first bush 10 can be obtained by drawing the outer cylinder 30 of the vulcanized molded body in the diameter reducing direction. The vibration isolator 1 is obtained by press-fitting the first bush 10 into the first cylindrical holder 81 and the second cylindrical holder 82 of the connecting member 80 (see FIG. 1) with the angle around the axis C aligned. be able to.

  When the rubber-like elastic body 40 is vulcanized and bonded to the shaft member 20 and the outer cylinder 30, tensile strain remains at the bonding interface due to the crosslinking shrinkage of the rubber-like elastic body 40, but the outer cylinder 30 is drawn. As a result, the tensile strain at the adhesive interface can be suppressed. Thereby, durability of the vibration isolator 1 can be improved. Moreover, since the rubber-like elastic body 40 is vulcanized and molded between the shaft member 20 and the outer cylinder 30, the mold is not excessive and the processability is excellent.

  According to the vibration isolator 1 configured as described above, the concentric convex surface portion 24 and the concave surface portion 33 are formed on the shaft member 20 and the outer cylinder 30 in the first bush 10 and the second bush 70, and the outer cylinder 30. The concave surface portion 33 is formed in a continuous spherical shape. The concave surface portion 33 faces the convex surface portion 24 of the shaft member 20, and the rubber-like elastic body 40 interposed between the concave surface portion 33 and the convex surface portion 24 can have a substantially constant thickness in the axial direction X. As a result, it is possible to suppress the non-uniform stress from acting on the rubber-like elastic body 40 interposed between the concave surface portion 33 and the convex surface portion 24 at the time of displacement in the twisting direction Z or the direction perpendicular to the axis Y. Thereby, durability of the vibration isolator 1 can be improved.

  Further, when the vibration isolator 1 is used, the concentric convex surface portion 24 and the concave surface portion 33 are formed on the shaft member 20 and the outer cylinder 30 in the first bush 10 and the second bush 70, so that the first bush 10 and the first bush It can be avoided that the strain of the rubber-like elastic body 40 differs significantly between the two bushes 70. As a result, it is possible to suppress the life of the rubber-like elastic body 40 of either the first bush 10 or the second bush 70 from reaching an extremely early time and improve the durability of the vibration isolator 1.

  Further, since the second bush 70 is composed of members having the same shape and the same dimensions as the first bush 10 and is set to have the same spring constant, the second bush 70 and the first bush 10 can be shared. The number of parts can be reduced. Further, since the second bush 70 and the first bush 10 can be made common, the procedure and method of press-fitting work of the first bush 10 and the second bush 70 can be simplified, and the productivity of the vibration isolator 1 can be simplified. Can be improved.

  Moreover, since the 1st bush 10 and the 2nd bush 70 are comprised by the member of the same shape and the same dimension, and are set to the same spring constant, durability of the vibration isolator 1 can be improved. That is, when the spring constants of the first bush 10 and the second bush 70 are different from each other, the rubber-like elastic body 40 of the bush having a small spring constant is greatly distorted. However, it has been difficult to improve the durability of the vibration isolator 1. On the other hand, by setting the spring constants of the first bush 10 and the second bush 70 to the same setting, it is possible to suppress an increase in the load of one rubber-like elastic body 40, and the vibration isolator 1 Durability can be improved.

  Further, according to the vibration isolator 1, the rubber-like elastic body 40 interposed between the concave surface portion 33 and the convex surface portion 24 can be made to have a substantially constant thickness in the axial direction X. The concave portion 33 restricts the escape of the rubber in the axial direction X, and the spring constant in the direction perpendicular to the axis Y can be secured. At the time of displacement in the axial direction X, the rubber-like elastic body 40 between the convex surface portion 24 and the concave surface portion 33 undergoes shear deformation and compression deformation, thereby ensuring a spring constant in the axial direction X.

  Further, at the time of displacement in the twisting direction Z, the rubber-like elastic body 40 interposed between the convex surface portion 24 and the concave surface portion 33 is mainly subjected to shear deformation, so that the rubber-like elasticity between the shaft member 20 and the outer cylinder 30 is obtained. It can suppress that the axial direction edge part of the body 40 is compressively deformed. As a result, the spring constant in the twisting direction Z can be reduced.

  Further, since the rubber-like elastic body 40 has the annular straight portion 41 recessed in the circumferential direction of the axial end surface toward the inner side in the axial direction, the displacement between the convex surface portion 24 and the concave surface portion 33 at the time of displacement in the twisting direction Z. The rubber-like elastic body 40 interposed therebetween is substantially sheared and deformed so that the axial end portion of the rubber-like elastic body 40 is compressed and deformed between the shaft member 20 and the outer cylinder 30 as much as possible. As a result, the spring constant in the twisting direction Z can be effectively reduced.

  Next, with reference to FIG. 4, the effect when the spring constant in the twisting direction of the first bush 10 and the second bush 70 is reduced will be described. FIG. 4 is a schematic diagram showing the relationship between the angle and magnitude of displacement in the twisting direction Z of the first bush 10 and the second bush 70 and the length of the connecting member 80.

  As shown in FIG. 4, the first bush 10 of the vibration isolator 1 is attached to a vibration generating member I such as a power plant, and the second bush 70 is attached to a vibration receiving member O such as a vehicle body. The The first bush 10 and the second bush 70 are connected to each other by a connecting member 80. The length of the connecting member 80 is L1. If the vibration generating member I is displaced by a size (distance) D with respect to the vibration receiving member O, the connecting member 80 is displaced by an angle θ1 with respect to the first bush 10. Since the vibration isolator 1 can reduce the spring constant in the twisting direction of the first bush 10 and the second bush 70, the angle θ1 of the displacement that can be absorbed between the vibration generating side and the vibration receiving side can be increased.

  On the other hand, when the spring constant in the twisting direction Z is larger than the vibration isolator 1, the angle of the absorbable displacement between the vibration generating side and the vibration receiving side is smaller than that of the vibration isolator 1 of the present invention. . When this angle is θ2 (θ2 <θ1), the length of the connecting member is L2 (L2> L1) as the displacement angle is small. Therefore, if the spring constant in the twisting direction of the first bush 10 and the second bush 70 can be reduced as in the vibration isolator 1 of the present invention, the angle of the absorbable displacement between the vibration generating side and the vibration receiving side is increased. The connecting member 80 that connects the first bush 10 and the second bush 70 can be shortened (L1 <L2). If the connecting member 80 can be shortened, the mass of the connecting member 80 (including the mass of the outer cylinder 30 of the first bush 10 and the second bush 70) can be reduced, and the resonance frequency of the connecting member 80 can be set under the condition that the spring constant is not changed. Can be raised. Thereby, the vibration damping characteristic of the vibration isolator 1 can be controlled.

  Conventionally, in order to increase the resonance frequency of the connecting member 80, there is a method of attaching a dynamic damper to the connecting member. According to this method, there is a problem that the mass increases due to the attachment of the dynamic damper, and the production cost increases due to an increase in the number of parts and an increase in the number of attachment steps. On the other hand, according to the vibration isolator 1 of the present invention, since the resonance frequency of the connecting member 80 can be increased without attaching a dynamic damper, there is a problem that the mass increases, the number of parts, and the installation work. The vibration damping characteristics can be controlled while solving the problem of increasing the number.

  Further, as shown in FIG. 1, the rubber-like elastic body 40 includes a recessed portion 42 formed at a position intersecting with an imaginary straight line A along the connecting direction of the first bush 10 and the second bush 70. The spring constant of the rubber-like elastic body in the direction perpendicular to the axis (the left-right direction in FIG. 1) along the connecting direction of the bush 10 and the second bush 70 is defined as It can be made smaller than the spring constant. As a result, vibration transmission to the vibration receiving side is suppressed when high-frequency and small-amplitude vibration such as idling is input in the direction along the connecting direction of the first bush 10 and the second bush 70 of the vibration isolator 1. it can.

  Next, a second embodiment will be described with reference to FIGS. In 1st Embodiment, the case where the 1st bush 10 and the 2nd bush 70 were connected by the connection member 80 in the axial parallel was demonstrated. In contrast, in the second embodiment, a case will be described in which the first bush 110 and the second bush 170 are connected by the connecting member 180 so that the axial directions thereof are orthogonal to each other.

  Moreover, 1st Embodiment demonstrated the case where the shaft member 20 was comprised by the single member. On the other hand, in the second embodiment, a case will be described in which an inner cylinder 120 and an intermediate cylinder 140 are integrally vulcanized and bonded with an inner elastic portion 150 formed of a rubber-like elastic material as a shaft member. In addition, the same part as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the following description. First, a schematic configuration of the image stabilizer 101 will be described with reference to FIG. FIG. 5 is a plan view of the vibration isolator 101 according to the second embodiment.

  As shown in FIG. 5, the vibration isolator 1 includes a first bush 110 attached to a power plant side (vibration generating side) (not shown) and a second bush attached to a vehicle body side (vibration receiving side) (not shown). 170 and a connecting member 180 that connects the first bush 110 and the second bush 170 to each other. The connecting member 180 includes a first cylindrical holder 181 and a second cylindrical holder 182 formed in a cylindrical shape at both ends of the rod portion 183, and the first cylindrical holder 181 and the second cylindrical holder 182 are axially connected to each other. It is disposed at a position where the directions are orthogonal. The first bush 110 and the second bush 170 are press-fitted into the first cylindrical holder 181 and the second cylindrical holder 182 so that the axial directions are orthogonal to each other. In the present embodiment, the second bush 170 is configured by a member having the same shape and the same dimensions as the first bush 110, and is set to the same spring constant. Therefore, the first bush 110 will be described, and the description of the second bush 170 will be omitted.

  As shown in FIG. 5, the first bush 110 includes a cylindrical inner cylinder 120, an outer cylinder 130 arranged coaxially with the inner cylinder 120 on the outer peripheral side of the inner cylinder 120, and the inner cylinder 120. A cylindrical intermediate cylinder 140 disposed on the outer peripheral side and the inner peripheral side of the outer cylinder 130, and interposed between the inner cylinder 120 and the intermediate cylinder 140 and configured by a cylindrical rubber-like elastic material. It includes an inner elastic portion 150 and an outer elastic portion 160 that is interposed between the intermediate cylinder 140 and the outer cylinder 130 and is made of a cylindrical rubber-like elastic material.

  The inner cylinder 120 is a metal cylindrical member, and a fastening member such as a bolt is inserted into an insertion hole 121 formed in the center, and is fastened and fixed to the power plant side. The outer cylinder 130 is a metal cylindrical member, and is arranged in parallel with the inner cylinder 120. The intermediate cylinder 140 is a metal cylindrical member, and is disposed concentrically between the inner cylinder 120 and the outer cylinder 130. The inner cylinder 120 and the intermediate cylinder 140 are connected by the inner elastic portion 150 over the entire circumference, and the intermediate cylinder 140 and the outer cylinder 130 are connected by the outer elastic portion 160 over the entire circumference.

  The inner elastic portion 150 and the outer elastic portion 160 are cylindrical members made of a rubber-like elastic material, and annular straight portions 151 and 161 (see FIG. 6B) are recessed in the circumferential direction of the axial end surface. It is installed. The inner elastic portion 150 and the outer elastic portion 160 are formed with recessed portions 152 and 162 that are provided on the inner side in the axial direction of the straight portions 151 and 161 at positions sandwiching the inner cylinder 120. The recessed portions 152 and 162 are positioned so as to intersect the virtual straight line A along the connecting direction of the first bush 110 and the second bush 170.

  Next, the first bush 110 will be described with reference to FIGS. 6 and 7. 6A is a plan view of the first bush 110, FIG. 6B is a cross-sectional view of the first bush 110 taken along the line VIb-VIb of FIG. 6A, and FIG. It is the elements on larger scale of the 1st bush 110 which expanded and showed the part shown by VII. 6B and 7, arrow X indicates the axial direction, arrow Y indicates the direction perpendicular to the axis, arrow Z indicates the twisting direction, and arrow N indicates the twisting direction.

  As shown in FIG. 6A, the first bush 110 includes an inner cylinder 120, an outer cylinder 130 that surrounds the inner cylinder 120 coaxially and coaxially, and the inner cylinder 120 that pivots between the inner cylinder 120 and the outer cylinder 130. An intermediate cylinder 140 that is surrounded in parallel and coaxially, an inner elastic part 150 that is interposed between the inner cylinder 120 and the intermediate cylinder 140, and an outer elastic part 160 that is interposed between the intermediate cylinder 140 and the outer cylinder 130. And.

  As shown in FIG. 6B and FIG. 7, the inner cylinder 120 has an insertion hole 121 formed through the end surface in the axial direction in the center, and the outer peripheral surface 122 is axially inward from the axial end portion. An inclined portion 122a that is inclined inward in the direction perpendicular to the axis as it goes is formed over the entire circumference. The reduced diameter portion 123 is a portion continuously provided on the inner side in the axial direction of the inclined portion 122a, and is a cylindrical surface formed by reducing the diameter inward in the direction perpendicular to the axis by the amount of the inclined portion 122a with respect to the outer diameter of the outer peripheral surface 122. It is. The inner cylinder 120 includes a bulging portion 124 that bulges around the entire circumference in the central portion in the axial direction X in the direction Y perpendicular to the axis and has a spherical outer peripheral surface. The bulging portion 124 forms a convex spherical surface (virtual spherical surface K, see FIG. 7), is formed in a spherical shape having a center P on the axis C, and is formed continuously from the reduced diameter portion 123. ing.

  The intermediate cylinder 140 is a thin-walled cylindrical member made of metal, and a central portion in the axial direction X surrounding the bulging portion 124 is bent and bulges in a curved shape over the entire circumference toward the outer side perpendicular to the axis. Is provided with a convex surface portion 141 formed in a spherical shape. The convex surface portion 141 is formed in a spherical belt shape, and the curved portion 142 on the inner peripheral surface (back surface) of the convex surface portion 141 is concentric with the bulging portion 124 (that is, has a common center P). (See FIG. 7). Further, the convex surface portion 141 constitutes a convex spherical surface (virtual spherical surface M, see FIG. 7) concentric with the bulging portion 124. In addition, the convex surface part 141 and the curved part 142 are formed smoothly continuously from the cylindrical surface at the axial end of the intermediate cylinder 140.

  The outer cylinder 130 is formed in a cylindrical shape whose outer shape has a circular cross section and whose outer peripheral surface 131 has a constant diameter in the axial direction X. In addition, a concave surface portion 133 is formed on the inner peripheral surface 132 of the outer cylinder 130. The concave surface portion 133 is curved and recessed outward in the direction perpendicular to the axis as it goes inward in the axial direction from the axial end. The concave surface portion 133 is formed so as to be opposed to the convex surface portion 141, and the central portion in the axial direction X is concentric with the convex surface portion 141 (that is, has a common center P). 7).

  More specifically, in the shape after drawing, which will be described later, the outer cylinder 130 is formed as a concave spherical surface that is recessed outward in the direction perpendicular to the axis Y so as to follow the convex surface portion 141 of the intermediate cylinder 140 at a certain interval. A concave surface 133 is formed at the center in the axial direction X. The concave surface portion 133 is formed in a spherical band shape having the center P on the axis C, and is formed continuously continuously from the cylindrical inner peripheral surface 132 at the axial end portion of the outer cylinder 130. In the state before the drawing of the outer cylinder 130, the concave surface portion 133 is not a strict concave spherical surface, and the center P is at a position shifted from the axis C of the outer cylinder to the outside in the direction perpendicular to the axis Y. The center P is formed into a spherical band located on the axis C by drawing in the direction.

  In the outer cylinder 130, the concave surface portion 133 is recessed at the central portion in the axial direction X of the inner peripheral surface 132, so that the thickness at the central portion in the axial direction X is thinner than the thickness at both end portions in the axial direction X. It is formed. Thereby, the diameter of the outer peripheral surface 131 of the outer cylinder 130 can be made constant over the axial direction X. As a result, a sufficient axial dimension for press-fitting between the first cylindrical holder 181 and the second cylindrical holder 182 (see FIG. 5) can be ensured, and the first cylindrical holder 181 and the second cylindrical holder 181 The removal force from the cylindrical holder 182 can be improved.

  The inner elastic portion 150 is a cylindrical rubber member that connects the inner cylinder 120 and the intermediate cylinder 140, and includes an outer peripheral surface of the inner cylinder 120 including the bulging portion 124 and an inner peripheral surface of the intermediate cylinder 140 including the curved portion 142. And vulcanized and bonded to each other. The outer elastic portion 160 is a cylindrical rubber member that connects the intermediate tube 140 and the outer tube 130, and includes an outer peripheral surface of the intermediate tube 140 including the convex surface portion 141 and an inner peripheral surface of the outer tube 130 including the concave surface portion 133. Each is vulcanized and bonded. The inner elastic part 150 and the outer elastic part 160 are formed of the same rubber material.

  At the time of displacement in the twisting direction Z, the inner elastic portion 150 interposed between the bulging portion 124 and the curved portion 142 and the outer elastic portion 160 interposed between the convex surface portion 141 and the concave surface portion 140 are mainly used. It is possible to suppress the inner elastic part 150 and the outer elastic part 160 from being compressively deformed by shear deformation. Thus, the spring constant in the twisting direction Z can be reduced by mainly shearing and deforming the inner elastic portion 150 and the outer elastic portion 160.

  The inner elastic portion 150 is not only filled between the bulging portion 124 and the curved portion 142, but also has a rubber film 153 connected to the inner elastic portion 150 extending to the reduced diameter portion 123 and the inclined portion 122a. The rubber film 154 is extended on the cylindrical surface outside the curved portion 142 in the axial direction. Thereby, the adhesion area of the inner side elastic part 150 can be enlarged. Similarly, the outer elastic portion 160 is not only filled between the convex surface portion 141 and the concave surface portion 133, but the rubber film 163 extends to the cylindrical surface outside the convex surface portion 141 in the axial direction. A rubber film 164 extends on the inner peripheral surface 132 on the axially outer side from the concave surface portion 133. Thereby, also about the outer side elastic part 160, an adhesion area can be enlarged.

  Further, the inner elastic portion 150 and the outer elastic portion 160 are provided with recessed annular straight portions 151 and 161 that are recessed inward in the axial direction in the circumferential direction of the axial end surface. The straight portions 151 and 161 have an axial cross section formed in an arc shape, and extend inward in the axial direction at two locations in the circumferential direction of the straight portions 151 and 161 and have a concave portion 152 having an arc cross section in the axial direction. , 162 are formed. Since the straight portions 151 and 161 are formed on the inner elastic portion 150 and the outer elastic portion 160, the inner elastic portion 150 and the outer elastic portion 160 are displaced between the intermediate cylinder 140 and the outer cylinder 130 when displaced in the twisting direction Z. It can avoid as much as possible that an axial direction edge part compresses and deforms. By substantially shearing and deforming the inner elastic portion 150 and the outer elastic portion 160, the spring constant in the twisting direction Z can be effectively reduced.

  In the axial cross section of the outer elastic portion 160, the phantom spherical surface Q defined by the concave surface portion 133 intersects the concave portion 162 at the intersection S. The recessed portion 162 includes an arc portion 162a that is connected to the rubber film 164 and has an axial cross section formed in an arc shape. The intersection point S is located at the root of the rubber film 164 of the arc portion 162a, and the arc portion 162a is located inside the phantom spherical surface Q (center P side, see FIG. 6B).

  In addition, in the axial cross section of the inner elastic portion 150, the phantom spherical surface M defined by the convex surface portion 141 intersects the concave portion 152 at the intersection point R. The recessed portion 152 includes an arc portion 152a that is connected to the rubber film 154 and has an axial cross section formed in an arc shape. The intersection R is located at the root of the rubber film 154 of the arc portion 152a, and the arc portion 152a is located inside the phantom spherical surface M (center P side, see FIG. 6B).

  As described above, the inner elastic portion 150 and the outer elastic portion 160 are provided with the concave portions 152 and 162 that are continuously provided on the inner sides in the axial direction of the straight portions 151 and 161, so that the axis perpendicular to which the concave portions 152 and 162 are formed. The spring constants of the inner elastic portion 150 and the outer elastic portion 160 in the direction Y (FIG. 6 (a) left-right direction) may be made smaller than the spring constants in the other axis perpendicular direction Y (FIG. 6 (a) vertical direction). it can. As a result, vibration transmission when high-frequency and small-amplitude vibration is input in this direction can be suppressed.

  Further, since the arc portions 152a, 162a of the recessed portions 152, 162 are located inside the virtual spherical surfaces M, Q, the inner cylinder is displaced when the axial cross section in which the recessed portions 152, 162 are formed is displaced in the twisting direction Z. It is possible to reliably avoid compressive deformation of the axial ends of the inner elastic portion 150 and the outer elastic portion 160 between the 120 and the outer cylinder 130. As a result, the spring constant in the twisting direction Z can be further reduced in the plane in which the recessed portions 152 and 162 are formed.

  Here, as shown in FIGS. 6B and 7, the intermediate cylinder 140 has a circular through hole 143 that penetrates the cylindrical surface in the thickness direction on the cylindrical surface outside the convex portion 141 in the axial direction. Is formed. The through holes 143 are respectively provided on the cylindrical surfaces on the outer side (both sides) of the convex surface portion 141 in the axial direction X, and are not provided on the convex surface portion 141. The inner elastic portion 150 and the outer elastic portion 160 are connected through the through hole 143. A plurality of through holes 143 are formed at equal intervals in the circumferential direction of the intermediate cylinder 140.

  In order to manufacture the first bush 110, first, the inner cylinder 120, the outer cylinder 130, and the intermediate cylinder 140 are formed and then placed in a mold (not shown). Next, the inner elastic portion 150 and the outer elastic portion 160 are vulcanized and molded between the inner cylinder 120 and the outer cylinder 130 by injecting a molding material such as a rubber material into the molding die. At that time, the rubber material is injected from the injection hole into a cavity (not shown) for molding the outer elastic portion 160. The injected rubber material passes through the through-hole 143 formed in the intermediate cylinder 140 and flows into the inner cavity, so that the inner elastic portion 150 is formed. The inner cylinder 120, the intermediate cylinder 140, the outer cylinder 130, the inner elastic portion 150, and the outer elastic portion 160 are integrally vulcanized and bonded to obtain a vulcanized molded body before drawing. Next, the first bushing 110 can be obtained by drawing the outer tube 130 of the vulcanized molded body in the direction of diameter reduction. The first bush 110 is press-fitted into the first cylindrical holder 181 and the second cylindrical holder 182 of the connecting member 180 (see FIG. 5) with the angle around the axis C aligned, thereby obtaining the vibration isolator 101. be able to.

  According to the first bushing 110 of the vibration isolator 101 configured as described above, the inner elastic portion between the bulging portion 124 of the inner cylinder 120 and the curved surface 142 of the intermediate cylinder 140 when displaced in the twisting direction Z. 150 and the outer elastic portion 160 between the convex surface portion 141 of the intermediate tube 140 and the concave surface portion 133 of the outer tube 130 are mainly subjected to shear deformation. Therefore, the spring constant in the twisting direction Z can be effectively reduced.

  Further, with respect to the displacement in the axial direction X, the inner elastic portion 150 between the bulging portion 124 of the inner cylinder 120 and the curved surface 142 of the intermediate cylinder 140 and the convex surface portion 141 of the intermediate cylinder 140 and the concave surface of the outer cylinder 130. The outer elastic part 160 between the part 133 receives not only shear deformation but also compression deformation. Therefore, the spring constant in the axial direction X can be increased. Moreover, the provision of the intermediate cylinder 140 increases the spring constant in the direction perpendicular to the axis Y. Therefore, when the spring constant in the direction perpendicular to the axis Y is set to be equivalent to the case where the intermediate tube 140 is not provided (first embodiment), a softer elastic material can be used. Thereby, the spring constant of the twist direction N can be lowered. As described above, the spring constants in the twisting direction Z and the torsional direction N can be effectively reduced while securing the spring constants in the axial direction X and the axially perpendicular direction Y.

  Further, the axial end portion of the outer elastic portion 160 that is compressed when displaced in the twisting direction Z is connected to the inner elastic portion 150 through a through hole 143 provided in the intermediate cylinder 140. Therefore, the rubber portion to be compressed at the axial end of the outer elastic portion 160 can be released to the inner elastic portion 150 side through the through hole 143, so that the spring constant in the twisting direction Z can be effectively reduced. . Further, the through-hole 143 itself hardly affects the spring constant in the axial direction X, the axis perpendicular direction Y, and the torsional direction N, so that the spring constant in the twisting direction Z is reduced while maintaining other spring characteristics. be able to.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed. For example, the numerical values (for example, the number and size of each component) given in the above embodiment are merely examples, and other numerical values can naturally be adopted.

  In each of the above embodiments, the case where the first bushes 10 and 110 and the second bushes 70 and 170 are press-fitted into the first cylindrical holders 81 and 181 and the second cylindrical holders 82 and 182 has been described. It is not limited to this. For example, after creating a connecting member in which the outer cylinders 30 and 130 are connected to both ends of the rod portions 83 and 183, the connecting member and the shaft member 20, the inner cylinder 120, and the intermediate cylinder 140 are set in a vulcanization mold. It is possible to manufacture the vibration isolator 1 and 101 by vulcanizing and molding the rubber-like elastic material to the outer cylinders 30 and 130 and integrally vulcanizing and bonding them. Thereby, productivity of the vibration isolator 1 and 101 can be improved.

  In the first embodiment, the case where the shaft member 20 and the rubber-like elastic body 40 are vulcanized and bonded in the first bush 10 and the second bush 70 has been described. However, the present invention is not necessarily limited thereto. Of course, it is possible to press-fit the shaft member 20 into the cylindrical rubber-like elastic body 40 and to interpose the rubber-like elastic body 40 between the shaft member 20 and the outer cylinder 30. Thereby, it can suppress that a tensile strain remains in the adhesion interface of the rubber-like elastic body 40, and the fracture life of the rubber-like elastic material 40 can be improved. Similarly, it is possible to press-fit a cylindrical rubber-like elastic body 40 into the outer cylinder 30. Similarly, in the first bush 110 and the second bush 170 described in the second embodiment, it is naturally possible to press-fit the inner elastic portion 150 and the outer elastic portion 160 instead of vulcanizing and bonding them. .

  In each of the above embodiments, the case where the recessed portions 42, 152, 162 are formed in part of the axial end surfaces of the first bushes 10, 110 and the second bushes 70, 170 has been described. It is also possible not to provide the concave portions 42, 152, 162. Accordingly, it is possible to obtain a vibration insulating effect and a damping effect regardless of the vibration input direction.

  Moreover, although the case where the recessed part 42,152,162 was formed in the position which cross | intersects the virtual straight line along the connection direction of the 1st bush 10,110 and the 2nd bush 70,170 was demonstrated, it is not necessarily restricted to this. Of course, it is possible to form at any position where the spring constant needs to be reduced.

  In each of the above embodiments, the case where the straight portions 41, 151, 161 are formed on the entire circumference of the axial end surfaces of the first bushes 10, 110 and the second bushes 70, 170 has been described. If there is a demand to increase the spring constant, it is naturally possible not to provide the straight portions 41, 151, 161.

  In each of the above-described embodiments, the case where the connecting members 80 and 180 are formed in a rod shape has been described. However, the present invention is not necessarily limited to this, and the plate member or the flange portion is provided. It is possible to employ other connecting members according to demands such as weight reduction.

  The first cylindrical holder 181 of the connecting member 180 is replaced by replacing the first bush 10 and the second bush 70 described in the first embodiment with the first bush 110 and the second bush 170 described in the second embodiment. It is possible to press-fit the first bush 10 and the second bush 70 into the second cylindrical holder 182.

  In the first embodiment, the case where the convex portion 24 is formed integrally with the shaft member 20 has been described. However, the present invention is not limited to this, and a synthetic resin or metal annular covering is prepared as a separate member. However, it is naturally possible to form the convex surface portion 24 by providing this on the outer peripheral surface of the shaft member 20. Similarly, in the intermediate tube 140 described in the second embodiment, the convex surface portion 141 can be provided as a separate member instead of being formed integrally.

  In the second embodiment, the case where the bulging portion 124 is provided in the inner cylinder 120 has been described. However, if the outer peripheral surface of the intermediate cylinder 140 has the convex surface portion 141, the inner cylinder 120 has the bulging portion 124. The same effect can be realized even when it does not have.

  In the above-described embodiment, an automobile torque rod is exemplified as the vibration isolator 1. However, the present invention is not only applied to the torque rod but also suitably used for, for example, a suspension arm. Moreover, it is not limited to the object for motor vehicles, It can apply as an object for trains or other various connection rods.

1,101 Vibration isolator 10,110 First bush 20 Shaft member 120 Inner tube (part of shaft member)
140 Intermediate tube (part of shaft member)
150 Inner elastic part (part of shaft member)
24,141 Convex part 30,130 Outer cylinder 33,133 Concave part 40 Rubber elastic body 160 Outer elastic part (rubber elastic body)
42, 152, 162 Recessed part 42a, 162a Arc part 70, 170 Second bush 80, 180 Connecting member 81, 181 First cylindrical holder 82, 182 Second cylindrical holder F, Q Virtual spherical surface

Claims (4)

In a vibration isolator comprising a first bush attached to the vibration generating side, a second bush attached to the vibration receiving side, and a connecting member for connecting the first bush and the second bush to each other.
The first bush and the second bush are:
A shaft member having a convex surface portion that is formed in a cylindrical shape and has a central portion in the axial direction bulging outward in a direction perpendicular to the axis and having an outer peripheral surface formed in a spherical shape;
The inner peripheral surface of the shaft member is located on the outer peripheral side of the shaft member in parallel with the shaft member and connected to the connecting member, and the central portion in the axial direction is recessed outward in the direction perpendicular to the axis relative to the convex surface portion. An outer cylinder having a concave surface formed in a continuous spherical shape;
A vibration isolator comprising a rubber-like elastic body interposed between an outer peripheral surface of the shaft member and an inner peripheral surface of the outer cylinder. The connecting member is formed in a cylindrical shape and includes a first cylindrical holder and a second cylindrical holder at both ends into which the outer cylinders of the first bush and the second bush are press-fitted, respectively.
2. The vibration isolator according to claim 1, wherein the second bush is configured by a member having the same shape and the same size as the first bush and is set to have the same spring constant.   The vibration isolator according to claim 1 or 2, wherein the rubber-like elastic body includes a recessed portion that is recessed in a part of an axial end surface of the first bush and the second bush. . The recessed portion includes an arc portion whose axial cross section is formed in an arc shape,
The vibration isolator according to claim 3, wherein a virtual spherical surface defined by the concave surface portion intersects with the concave concave portion, and the arc portion is located inside the virtual spherical surface.

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