Cylindrical anti-vibration device for railway vehicle

Abstract

The invention provides a cylindrical anti-vibration device for a railway vehicle. An inner shaft member (12) and an outer cylinder member (14) are connected to each other by a cylindrical connecting rubber (16), the connecting rubber (16) is fixedly attached to the outer peripheral surface of the inner shaft member (12) and the inner peripheral surface of the outer cylinder member (14), and the outer peripheral end of the connecting rubber (16) is provided with an inner shaft (14) and an outer shaft (14). A pair of slits (40, 40) extending in the circumferential direction and penetrating in the axial direction are formed on both sides in the radial direction sandwiching the inner shaft member (12), and the circumferential length of each slit (40) is formed so as to be longer than the circumferential length of the connecting rubber (16) between the pair of slits (40, 40) in the circumferential direction. Protruding parts (32, 32) protruding toward the outer periphery of the pair of slits (40, 40) are partially provided in the axial direction.

Description

Technical Field

[0001] The present invention relates to a cylinder type anti-vibration device for railway vehicles. Background Art

[0002] Cylinder-type vibration isolators have been used in railroad vehicle trolleys, etc. For example, as disclosed in Japanese Patent Publication No. 2007-139100 (Patent Document 1), the cylinder-type vibration isolators have a structure in which an inner shaft member (pin 8) and an outer cylinder member (outer cylinder 7) are connected to each other by a connecting rubber (rubber cylinder 9).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-139100 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, regarding the cylindrical vibration isolating device for railway vehicles, generally, a hard spring characteristic is required during acceleration and deceleration with a large input load, and a soft spring characteristic is required during normal driving with a small input load. Therefore, in order to cope with the spring characteristics required as described above, a non-bonded cylindrical vibration isolating device is proposed in Patent Document 1, in which an inner shaft member and a connecting rubber are formed to be non-bonded and a gap portion is formed between the inner shaft member and the connecting rubber. As a result, in the cylindrical vibration isolating device of Patent Document 1, different spring characteristics can be obtained in the case where the displacement amount in the radial direction between the inner shaft member and the outer cylinder member is large and the case where the displacement amount is small.

[0008] However, if a gap is formed between the inner shaft member and the connecting rubber, there is a risk that foreign matter such as sand, dust, and water may intrude into the gap, which may cause problems such as abnormal sound and corrosion of the inner shaft member. In particular, as disclosed in Patent Document 1, the gap is formed by utilizing the thermal shrinkage of the connecting rubber after forming, so the width is narrow, and it is difficult to perform rust prevention treatment such as coating on the outer peripheral surface of the inner shaft member exposed in the gap after the connecting rubber is formed. Therefore, it is also considered that the inner shaft member is prone to rust when immersed in water, and the durability is reduced. In addition, when used in cold areas, the water entering the gap freezes and expands, and there is a risk that the spring characteristics will be affected.

[0009] The present invention aims to provide a new structure of a cylindrical anti-vibration device for railway vehicles, which can solve the above-mentioned problems of the non-adhesive type and realize the spring characteristics required as a cylindrical anti-vibration device for railway vehicles.

[0010] Methods used to solve problems

[0011] The following describes the preferred modes for understanding the present invention, but each mode described below is an exemplary mode, which can be appropriately combined with each other and adopted, and the multiple components described in each mode can be independently identified and adopted as much as possible, and can also be appropriately combined with any component described in other modes. Therefore, the present invention is not limited to the modes described below, and various other modes can be realized.

[0012] The first mode is a cylindrical vibration isolation device for railway vehicles in which an inner shaft member and an outer cylinder member are connected to each other by a cylindrical connecting rubber, the connecting rubber being fixedly mounted on the outer peripheral surface of the inner shaft member and the inner peripheral surface of the outer cylinder member, and at the outer peripheral end of the connecting rubber, a pair of slits extending in the circumferential direction and penetrating in the axial direction are formed on both sides of the radial direction clamping the inner shaft member, the circumferential length of each of the slits is formed to be longer than the circumferential length of the connecting rubber between the pair of slits, and a bulging portion protruding toward the outer periphery toward the pair of slits is partially provided in the axial direction at the fixed mounting portion of the connecting rubber in the inner shaft member.

[0013] According to the cylindrical vibration isolation device formed in accordance with the structure of this method, the connecting rubber is fixedly installed on the inner shaft component and the outer tube component, so foreign matter such as sand, dust, and water will not penetrate between the connecting rubber and the inner shaft component and between the connecting rubber and the outer tube component, thereby avoiding abnormal sounds, corrosion of the inner shaft component and the outer tube component, and other unfavorable conditions.

[0014] A pair of slits are formed at the connecting rubber on both sides of the radial direction relative to the inner shaft member, so that in the radial direction where the pair of slits are arranged, both the low spring characteristic when the small load input is small and the high spring characteristic when the large load input is large and the relative displacement between the inner shaft member and the outer cylinder member is large can be achieved. In particular, the circumferential length of the slit is formed to be longer than the circumferential length of the connecting rubber between the slits, so the compression spring and the shear spring of the connecting rubber relative to the radial input where the pair of slits are arranged are set small, and the low spring characteristic when the small load input is achieved more advantageously.

[0015] The inner shaft member is provided with a bulging portion protruding toward the pair of slits, so that the thickness dimension of the connecting rubber in the radial direction where the pair of slits are arranged is small. When the opposing inner surfaces of the slits abut against each other in the radial direction due to the input of a large load, the compression spring constant of the connecting rubber formed as a thin wall becomes large, and a hard spring characteristic can be exerted.

[0016] In addition, in the inner shaft member, a bulge is partially provided in the axial direction at the fixed installation portion of the connecting rubber, and there is a portion in the axial direction where the bulge is not provided at the fixed installation portion of the connecting rubber. As a result, the connecting rubber can be made thick-walled in the portion of the inner shaft member where the bulge is not provided, and the radial free length of the connecting rubber can be ensured, thereby achieving improvement in the durability of the connecting rubber. Even if a thick-walled portion of the connecting rubber as described above is provided, when a large load is input, a hard spring characteristic based on the compression of the thin-walled connecting rubber fixedly installed on the protruding front end surface of the bulge can be obtained in the radial direction where a pair of slits are arranged.

[0017] It should be noted that the bulge is preferably provided in the axial middle of the fixed installation portion of the connecting rubber in the inner shaft member, and the connecting rubber is formed as a thick wall at both axial ends of the fixed installation portion of the inner shaft member. According to this, the free surface of the axial end of the connecting rubber where distortion is likely to concentrate during elastic deformation of the connecting rubber can be widely ensured, so that the durability of the connecting rubber can be advantageously improved.

[0018] In a second aspect, in the cylindrical vibration isolating device according to the first aspect, the slit is formed in an expanding shape that becomes wider in the radial direction toward the openings on both sides in the axial direction.

[0019] According to the cylindrical vibration isolating device configured according to this aspect, when foreign matter such as sand, water, and wear debris of connecting rubber enters the slit, the foreign matter is easily discharged to the outside through the tapered inner surface of the slit that expands axially outward.

[0020] In a third aspect, in the cylindrical vibration isolating device according to the first or second aspect, the inner peripheral surface of the outer cylindrical member is covered with a buffer rubber layer formed integrally with the connecting rubber and constituting a wall surface on the outer peripheral side of the slit.

[0021] According to the cylindrical vibration-proof device formed in accordance with the structure of this method, the inner peripheral surface of the outer cylinder member is covered and protected by the buffer rubber layer, thereby ensuring the corrosion resistance of the outer cylinder member. In addition, when the inner surface of the slit is abutted, the elasticity of the buffer rubber layer can also be expected to reduce the knocking sound. It should be noted that the buffer rubber layer in this method is formed to be a thin wall that can be ignored in the vibration-proof characteristics, and the slit is located at the outer peripheral end of the connecting rubber.

[0022] In a fourth aspect, in the cylindrical vibration isolating device according to any one of the first to third aspects, the cylindrical vibration isolating device is provided with a pair of the bulging portions that protrude toward both sides in a radial direction toward the pair of slits.

[0023] According to the cylindrical vibration isolating device formed in the structure according to this mode, in the radial direction where the pair of bulging parts protrude, a hard spring characteristic when a large load is input in which the relative displacement amount between the inner shaft member and the outer cylinder member is large can be realized. In addition, in the radial direction orthogonal to the protruding direction of the pair of bulging parts, the thickness dimension of the connecting rubber is large, and the shear spring constant when the radial input in which the pair of slits are arranged is reduced, so that a softer spring characteristic when a small load is input can be realized.

[0024] In a fifth aspect, in the cylindrical vibration isolating device according to the fourth aspect, an outer peripheral surface of a fixing portion of the connecting rubber in the inner shaft member is constituted by a pair of flat surfaces in a radial direction orthogonal to a protruding direction of the pair of bulging portions.

[0025] According to the cylindrical vibration isolating device formed in the structure according to this mode, the radial distance between the inner shaft member and the outer cylinder member is ensured to be large in the radial direction where the pair of flat surfaces are provided, and the radial free length of the connecting rubber can be made longer in the portion connecting the inner shaft member and the outer cylinder member. Therefore, it is possible to achieve a reduction in the shear spring constant of the connecting rubber and an improvement in the durability of the connecting rubber.

[0026] In a sixth aspect, in the cylindrical vibration isolating device according to any one of the first to fifth aspects, the bulging portion is formed in an arc-shaped longitudinal cross-sectional shape.

[0027] According to the cylindrical anti-vibration device configured according to this aspect, the surface of the bulging portion is formed of a curved surface with an arc-shaped cross section without corners, thereby achieving stress dispersion in the connecting rubber fixedly attached to the surface of the bulging portion.

[0028] Furthermore, when input is applied in the prying direction between the inner shaft member and the outer cylinder member, the shear spring component becomes more dominant in the connecting rubber, so that the elasticity can be reduced.

[0029] In the seventh aspect, based on the cylindrical vibration isolation device described in any one of the first to sixth aspects, at the axial position where the bulge is provided, the circumferential length of a 90-degree area around the center axis of the inner shaft component in the radial direction where the pair of slits are located is formed to be longer than the circumferential length of a 90-degree area around the center axis of the inner shaft component in the radial direction orthogonal to the radial direction where the pair of slits are located.

[0030] According to the cylindrical vibration isolating device having the structure according to this embodiment, the portion of the inner surface of the slit constituting the connecting rubber can be fixed to the inner shaft member with a large fixing area, thereby obtaining a large fixing strength of the portion of the connecting rubber to the inner shaft member.

[0031] In an eighth aspect, in the cylindrical vibration isolating device according to any one of the first to seventh aspects, a wear reducing portion for suppressing wear of the connecting rubber is provided in the slit.

[0032] According to the cylindrical vibration reduction device formed into a structure according to this method, for example, a wear reduction portion is achieved by providing a lubricant coating on the inner surface of the slit, configuring a foam body that does not affect the spring characteristics in the slit, etc., so that the wear of the connecting rubber in the inner surface of the slit is suppressed, and damage to the connecting rubber and long-term stabilization of the spring characteristics can be achieved.

[0033] In a ninth aspect, in the cylindrical vibration isolation device according to any one of the first to eighth aspects, a portion of the connecting rubber located between the pair of slits in the circumferential direction is formed as a predetermined cutting portion, and the predetermined cutting portion is cut when the connecting rubber is mounted in a railway vehicle for use, and the connecting rubber is separated into an inner peripheral rubber fixedly mounted on the inner shaft member and an outer peripheral rubber fixedly mounted on the outer cylindrical member.

[0034] According to the cylindrical vibration isolation device formed in accordance with the present embodiment, when installed in a railway vehicle, the predetermined cutting portion is cut off and the connecting rubber is separated into the inner peripheral rubber and the outer peripheral rubber which are independent of each other, thereby being able to more advantageously realize the low spring characteristics in a state where the relative displacement in the radial direction between the inner shaft member and the outer cylindrical member is small.

[0035] In addition, in the single state of the cylindrical anti-vibration device before being installed on the railway vehicle, the inner peripheral rubber and the outer peripheral rubber are connected integrally by cutting the predetermined portion, and the inner shaft member and the outer cylindrical member are connected to each other by the connecting rubber. Therefore, the cylindrical anti-vibration device before use can be handled as a whole, for example, it is easy to transport and store.

[0036] For example, the portion to be cut off may be cut by performing a cutting operation while the cylindrical vibration isolator is mounted on a railway vehicle, or the portion to be cut off may be broken by input during use without performing a special operation to cut the portion to be cut off.

[0037] In a tenth aspect, in the cylindrical vibration isolating device according to any one of the first to ninth aspects, an intermediate member extending in the circumferential direction between the inner shaft member and the outer cylindrical member in radial directions is fixed to the connecting rubber.

[0038] According to the cylindrical vibration isolating device having the structure according to this embodiment, the spring characteristics can be adjusted by providing the intermediate member. That is, for example, the end of the connecting rubber on the slit side is constrained by the intermediate member, and the radial thickness of the connecting rubber is limited by the intermediate member, thereby achieving high elasticity in the radial direction where the pair of slits are arranged when the relative displacement between the inner shaft member and the outer cylinder member is large.

[0039] In an eleventh aspect, in the cylindrical vibration isolating device according to the tenth aspect, the intermediate member is disposed adjacent to the inner periphery of the slit.

[0040] According to the cylindrical vibration isolation device formed into a structure according to this method, the intermediate member is arranged adjacent to the inner periphery of the slit, so there is no rubber that affects the spring characteristics between the opposing surfaces of the intermediate member and the outer cylinder member, and the hard spring characteristics can be quickly exerted when the intermediate member and the outer cylinder member are directly or indirectly in contact.

[0041] In a twelfth aspect, in the cylindrical vibration isolating device according to the tenth or eleventh aspect, the intermediate member is constituted by a pair of plate-like members, and the pair of plate-like members are arranged on both sides of the same radial direction as the pair of slits.

[0042] According to the cylindrical vibration isolation device formed in accordance with the present embodiment, the intermediate member formed by the pair of plate-like members can simultaneously achieve high spring characteristics in the radial direction where the pair of slits are arranged and ensure the free length of the connecting rubber in the radial direction orthogonal to the arrangement direction of the pair of slits.

[0043] The thirteenth embodiment is a cylindrical vibration isolation device for a railway vehicle in which an inner shaft member and an outer cylinder member are connected to each other by a cylindrical connecting rubber, wherein the connecting rubber is fixedly mounted on the outer peripheral surface of the inner shaft member and the inner peripheral surface of the outer cylinder member, and a pair of slits extending in the circumferential direction and penetrating in the axial direction are formed on both sides of the radial direction of the inner shaft member, and a portion of the connecting rubber located between the pair of slits in the circumferential direction forms a predetermined cutting portion, and the predetermined cutting portion is cut off when the connecting rubber is assembled in a railway vehicle. The connecting rubber is separated into an inner peripheral rubber fixedly mounted on the inner shaft member and an outer peripheral rubber fixedly mounted on the outer cylinder member.

[0044] According to the cylindrical vibration isolation device formed in accordance with the present embodiment, when installed in a railway vehicle for use, the predetermined cutting portion is cut off and the connecting rubber is separated into inner peripheral rubber and outer peripheral rubber which are independent of each other, thereby being able to more advantageously realize a low spring characteristic in a state where the displacement amount between the inner shaft member and the outer cylindrical member is small.

[0045] In addition, in the single state of the cylindrical anti-vibration device before being installed on the railway vehicle, the inner peripheral rubber and the outer peripheral rubber are integrally connected by cutting the predetermined portion, and the inner shaft member and the outer cylindrical member are mutually connected by the connecting rubber. Therefore, the cylindrical anti-vibration device before use can be handled as a whole, for example, it is easy to transport and store.

[0046] For example, the portion to be cut off may be cut by performing a cutting operation while the cylindrical vibration isolator is mounted on a railway vehicle, or the portion to be cut off may be broken by input during use without performing a special operation to cut the portion to be cut off.

[0047] The fourteenth method is a cylindrical vibration isolation device for railway vehicles in which an inner shaft member and an outer cylinder member are nested and connected to each other by a cylindrical connecting rubber, the connecting rubber being fixedly mounted on the outer peripheral surface of the inner shaft member and the inner peripheral surface of the outer cylinder member, a pair of slits extending in the circumferential direction and penetrating in the axial direction are formed on both sides of the radial direction clamping the inner shaft member at the outer peripheral end of the connecting rubber, an intermediate member extending in the circumferential direction between the radial directions of the inner shaft member and the outer cylinder member is fixedly mounted on the connecting rubber, and the intermediate member is arranged adjacent to the inner periphery of the slit.

[0048] According to the cylindrical vibration isolating device having the structure according to this embodiment, the spring characteristics can be adjusted by providing the intermediate member. That is, for example, the end of the connecting rubber on the slit side is constrained by the intermediate member, and the radial thickness of the connecting rubber is limited by the intermediate member, thereby achieving high elasticity in the radial direction where the pair of slits are arranged when the relative displacement between the inner shaft member and the outer cylinder member is large.

[0049] Furthermore, since the intermediate member is disposed adjacent to the inner periphery of the slit, there is no rubber affecting the spring characteristics between the facing surfaces of the intermediate member and the outer tube member, and the hard spring characteristics can be quickly exhibited when the intermediate member and the outer tube member come into direct or indirect contact.

[0050] In a fifteenth aspect, in the cylindrical vibration isolating device according to the fourteenth aspect, the intermediate member is constituted by a pair of plate-like members, and the pair of plate-like members are arranged on both sides of the same radial direction as the pair of slits.

[0051] According to the cylindrical vibration isolation device formed in accordance with the present embodiment, the intermediate member formed by the pair of plate-like members can simultaneously achieve high spring characteristics in the radial direction where the pair of slits are arranged and ensure the free length of the connecting rubber in the radial direction orthogonal to the arrangement direction of the pair of slits.

[0052] In a sixteenth aspect, in the cylindrical vibration isolating device according to the fourteenth or fifteenth aspect, a curvature of an outer peripheral surface of the intermediate member is equal to a curvature of an inner surface on an outer peripheral side of the slit.

[0053] According to the cylindrical vibration isolation device formed into a structure according to this method, when the relative displacement in the radial direction of the inner shaft member and the outer cylinder member provided with a pair of slits is large, the inner peripheral side wall portion of the slit formed by the outer peripheral surface of the intermediate member abuts against the outer peripheral side wall portion of the slit over a wider range in the circumferential direction, thereby making it easier to achieve a hard spring characteristic.

[0054] Effects of the Invention

[0055] According to the present invention, in a cylinder-type vibration isolating device for railway vehicles, it is possible to solve non-adhesive problems such as abnormal noise and reduced durability, and at the same time, to realize spring characteristics required for railway vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a front view showing a cylindrical anti-vibration device for a railway vehicle as a first embodiment of the present invention.

[0057] Figure 2 yes Figure 1 II-II sectional view.

[0058] Figure 3 yes Figure 2 III-III sectional view.

[0059] Figure 4 yes Figure 2 IV-IV cross-sectional view.

[0060] Figure 5 Yes means Figure 1 Graph showing the spring characteristics in the left-right direction of the cylindrical anti-vibration device shown.

[0061] Figure 6 It is a front view showing a cylindrical anti-vibration device for a railway vehicle as a second embodiment of the present invention.

[0062] Figure 7 yes Figure 6 VII-VII sectional view.

[0063] Figure 8 It is a front view showing a cylindrical anti-vibration device for a railway vehicle as a third embodiment of the present invention.

[0064] Fig. 9 It is a front view showing a cylindrical anti-vibration device for a railway vehicle as a fourth embodiment of the present invention.

[0065] Fig.10 yes Fig. 9 The cross-sectional view of the cylindrical anti-vibration device shown is equivalent to Fig. 9 Diagram of the XX section.

[0066] Description of Reference Numerals

[0067] 10: Bushing for railway vehicles (first embodiment of a cylindrical anti-vibration device for railway vehicles);

[0068] 12: Inner shaft component;

[0069] 14: outer cylinder member;

[0070] 16: Connecting rubber;

[0071] 18: Installation department;

[0072] 20: fixed installation part;

[0073] 22: Mounting surface;

[0074] 24: bolt hole;

[0075] 26: cylindrical part;

[0076] 28: middle part;

[0077] 30: height difference surface;

[0078] 32: bulge;

[0079] 34: front end face;

[0080] 36: flat surface;

[0081] 38: Corner;

[0082] 40: Slit;

[0083] 42: Rubber arm;

[0084] 44: buffer rubber layer;

[0085] 46: Limiting rubber;

[0086] 48a, 48b: opposing inner surfaces;

[0087] 50: Bushing for railway vehicles (Second embodiment of a cylindrical anti-vibration device for railway vehicles);

[0088] 52: Slit;

[0089] 54: cutting off the predetermined portion;

[0090] 56: Inner rubber;

[0091] 58: peripheral rubber;

[0092] 60: Bushing for railway vehicles (third embodiment of a cylindrical anti-vibration device for railway vehicles);

[0093] 62: bulge;

[0094] 70: Bushing for railway vehicles (fourth embodiment of a cylindrical anti-vibration device for railway vehicles);

[0095] 72: Intermediate component;

[0096] 74: Plate-like member;

[0097] X: 90 degree area on the left and right;

[0098] Y: 90 degree area up and down;

[0099] A: small displacement area;

[0100] B: Large displacement area. DETAILED DESCRIPTION

[0101] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0102] exist Figure 1 to Figure 4 In the present invention, a bushing 10 for railway vehicles (hereinafter referred to as bushing 10) is shown as a first embodiment of a cylindrical vibration isolating device for railway vehicles according to the present invention. The bushing 10 has a structure in which an inner shaft member 12 and an outer cylinder member 14 are connected to each other by a connecting rubber 16. In the following description, in principle, the up and down directions refer to Figure 1 The up and down directions and the left and right directions refer to Figure 1 The left and right directions in the text are Figure 2 The left and right direction in .

[0103] The inner shaft member 12 is a hard member formed of, for example, a synthetic resin reinforced with metal / fiber, and is formed into a structure in which a fixed mounting portion 20 is integrally formed between a pair of mounting portions 18, 18. The mounting portion 18 is formed into a plate-like shape having a pair of flat mounting surfaces 22, 22, and having a bolt hole 24 that penetrates in the plate thickness direction. The side surface of the mounting portion 18 is curved in an arc shape and extends in the circumferential direction. It should be noted that the structure of the inner shaft member 12 is not limited to the structure specifically illustrated in the embodiment. For example, a solid rod-shaped inner shaft member can be used, and a non-through screw hole opening to the end face on one side of the axial direction can be formed with respect to the solid rod-shaped inner shaft member instead of the bolt hole 24. In addition, for example, in the case where the inner shaft member is fixed to the vehicle body or the dolly by a method such as pressing, there may be no bolt hole 24 or screw hole. In addition, for example, one or more than three mounting surfaces 22 can be provided in the mounting portion 18 of the inner shaft member.

[0104] The fixed mounting portion 20 is a portion where the connecting rubber 16 is fixedly mounted as described later, and the two end portions in the axial direction are formed as a pair of cylindrical portions 26, 26 with a substantially constant diameter size over the entire circumference, and an intermediate portion 28 is provided between these cylindrical portions 26, 26. The intermediate portion 28 is formed integrally with the cylindrical portions 26, 26, and the cross-sectional shapes are different from each other. The outer diameter size of the cylindrical portion 26 is slightly larger than the maximum outer diameter size of the mounting portion 18, and a step difference surface 30 extending orthogonally to the front-rear direction is formed over the entire circumference at the boundary portion between the cylindrical portion 26 and the mounting portion 18.

[0105] As in Figure 1 As indicated by the dotted lines in the figure, a pair of bulges 32, 32 protruding in the left-right direction are provided in the middle portion 28. The bulges 32 protrude outward in the left-right direction from the outer circumference of the cylindrical portion 26. The cross-sectional shape of the front end surface 34 of the bulge 32 is formed into an arc-shaped curved shape extending circumferentially concentrically with the outer circumference of the cylindrical portion 26. In the middle portion 28 of the present embodiment, the width dimension in the up-down direction orthogonal to the protruding direction of the pair of bulges 32, 32 is substantially the same as the diameter of the cylindrical portion 26. The front end surface 34 of the bulge 32 is formed in the Figure 3 The longitudinal section shown is curved in an arc shape and extends continuously in the circumferential direction in a substantially constant arc curved shape. Figure 2 , Figure 3 Shown is a cross section including the central axis of the bushing 10 extending in the front-rear direction.

[0106] The circumferential end surface of the bulging portion 32 is formed as a flat surface 36 extending orthogonally to the vertical direction. Therefore, in the radial direction orthogonal to the bulging portion 32 and the protruding direction of the bulging portion 32, the outer circumferential surface of the intermediate portion 28 of the inner shaft member 12 is composed of a pair of flat surfaces 36, 36. A corner portion 38 is formed at the intersection of the front end surface 34 and the flat surface 36 of the bulging portion 32. The corner portion 38 may be formed not by the front end surface 34 of the bulging portion 32 and the flat surface 36 being directly connected smoothly and continuously via a curved surface, but, for example, the corner portion 38 may be formed by smoothly and continuously forming a substantially angular shape via a curved surface with a small curvature radius, thereby preventing the occurrence of cracks in the connecting rubber 16 at the fixing and mounting portion of the connecting rubber 16 to the corner portion 38.

[0107] At the axial position where the bulge 32 is provided, a 90-degree area ( Figure 4The circumferential length of the 90-degree area Y above and below the slit 40 and the 90-degree area Y below and above the slit 40 is greater than the 90-degree area ( Figure 4 In the present embodiment, at the axial position where the bulges 32 and bulges 32 are provided, the outer circumferential surface of the inner shaft member 12 in the left and right 90 degree regions X and the left and right 90 degree regions X is composed of the bulges 32 and the front end faces 34 and the front end faces 34 of the bulges 32, and the outer circumferential surface of the inner shaft member 12 in the upper and lower 90 degree regions Y and the upper and lower 90 degree regions Y is composed of the flat surfaces 36 and the flat surfaces 36. It should be noted that the slit 40 described later extends over the entire circumferential length of the left and right 90 degree regions X, and the circumferential end portions extend and protrude to the upper and lower 90 degree regions Y.

[0108] Similar to the inner shaft member 12, the outer cylinder member 14 is also a hard member formed of a synthetic resin reinforced with metal or fiber, and is formed into a thin-walled, large-diameter, roughly cylindrical shape. The inner diameter dimension of the outer cylinder member 14 is formed to be larger than the maximum outer diameter dimension of the fixed mounting portion 20 of the inner shaft member 12, and is formed to be able to be nested in the fixed mounting portion 20 in a state of being spaced toward the outer periphery. The axial length dimension of the outer cylinder member 14 is formed to be larger than the axial length dimension of the fixed mounting portion 20 of the inner shaft member 12. However, the axial length dimension of the outer cylinder member 14 may be smaller than the axial length dimension of the fixed mounting portion 20 of the inner shaft member 12.

[0109] The outer cylinder member 14 is arranged in a nested state in the fixed mounting portion 20 of the inner shaft member 12, and the fixed mounting portion 20 of the inner shaft member 12 and the outer cylinder member 14 are elastically connected by the connecting rubber 16. The connecting rubber 16 is formed in a substantially cylindrical shape as a whole, and the inner peripheral surface is vulcanized and bonded to the outer peripheral surface of the fixed mounting portion 20 of the inner shaft member 12, and the outer peripheral surface is vulcanized and bonded to the inner peripheral surface of the outer cylinder member 14. In the present embodiment, the connecting rubber 16 is formed as an integral vulcanized molded product including the inner shaft member 12 and the outer cylinder member 14. In addition, the end position of the cavity in the mold for molding the connecting rubber 16 is defined by the height difference surface 30 of the inner shaft member 12, and the connecting rubber 16 is not fixedly mounted to the mounting portion 18 in the inner shaft member 12 but is only fixedly mounted to the outer peripheral surface of the fixed mounting portion 20. The surfaces on both axial sides of the connecting rubber 16 have a taper that is inclined toward the outer periphery and toward the axial inner side. It should be noted that, preferably, the inner shaft member 12 and the outer tube member 14 are subjected to pre-treatment such as painting, forming an adhesive layer, electroplating, etc. for the purpose of rust prevention and improving bonding strength before the forming of the connecting rubber 16, thereby preventing exposure to the outside and achieving improved durability.

[0110] The axial center portion of the inner peripheral end portion of the connecting rubber 16 is fixedly mounted to the outer peripheral surface including the front end surface 34 and the front end surface 34 of the pair of bulging portions 32, 32, and the axial ends are fixedly mounted to the outer peripheral surfaces of the pair of cylindrical portions 26, 26. In other words, the bulging portion 32 and the bulging portion 32 are provided in a part of the axial direction at the fixed mounting portion of the connecting rubber 16 in the inner shaft member 12. The axial end portions of the connecting rubber 16 are fixedly mounted to the inner shaft member 12 at the positions separated from the bulging portion 32 in the axial direction, thereby ensuring the thickness without becoming thinner due to the bulging portion 32.

[0111] A pair of slits 40, 40 are formed in the connecting rubber 16. The slits 40 are formed at the outer peripheral end of the connecting rubber 16, extend in the circumferential direction of the connecting rubber 16, and penetrate the connecting rubber 16 in the axial direction. The slits 40 are formed on both sides of the inner shaft member 12 in the left and right directions. In the present embodiment, the pair of slits 40, 40 are formed in mutually symmetrical shapes, and the radial width dimension and the circumferential length dimension are formed to be substantially the same as each other.

[0112] A pair of rubber arm portions 42, 42 are formed between the circumferential ends of the pair of slits 40, 40. The rubber arm portion 42 is a part of the connecting rubber 16, and connects the inner shaft member 12 and the outer cylinder member 14 to each other in the radial direction (up and down direction). The circumferential length dimension of the slit 40 is formed to be larger than the circumferential width dimension of the rubber arm portion 42. The circumferential length dimension of the slit 40 is preferably 1.25 times or more of the circumferential width dimension of the rubber arm portion 42, and more preferably 1.5 times or more.

[0113] A buffer rubber layer 44 constituting the wall surface of the outer peripheral side of the slit 40 is provided on the outer peripheral side of the slit 40. The buffer rubber layer 44 is integrally provided on the connecting rubber 16 to constitute the outer peripheral end of the connecting rubber 16, and is fixedly mounted on the inner peripheral surface of the outer tube member 14. The buffer rubber layer 44 covers substantially the entire inner peripheral surface of the outer tube member 14 except for both ends in the axial direction. The buffer rubber layer 44 is formed into a thin wall that is sufficiently thin so as not to affect the spring characteristics of the bushing 10 in the left-right direction.

[0114] A stopper rubber 46 constituting the wall surface of the inner peripheral side of the slit 40 is provided on the inner peripheral side of the slit 40. The stopper rubber 46 is integrally provided on the connecting rubber 16 to constitute the inner peripheral end of the connecting rubber 16, and the stopper rubber 46 is fixedly mounted on the inner shaft member 12 at the front end surface 34 of the bulging portion 32 protruding toward the slit 40. The stopper rubber 46 is formed to be thicker than the buffer rubber layer 44, and contributes to the spring characteristics of the bushing 10 in the left-right direction when it abuts against the outer cylinder member 14 side.

[0115] In the present embodiment, the circumference of the outer peripheral surface of the inner shaft member 12 is longer in the left and right 90 degree area X and the left and right 90 degree area X than in the top and bottom 90 degree area Y and the top and bottom 90 degree area Y. Thus, a large fixing area of ​​the stopper rubber 46 with respect to the inner shaft member 12 can be ensured, and the stopper rubber 46 can be firmly fixed to the inner shaft member 12.

[0116] The slit 40 is formed into an expansion shape that widens in the radial direction from the center in the axial direction toward the outside, and the opposing inner surface 48a on the inner peripheral side of the slit 40 is formed into a tapered surface that tilts toward the inner peripheral side from the center in the axial direction toward the two outer sides in the axial direction, and the opposing inner surface 48b on the outer peripheral side of the slit 40 is formed into a tapered surface that tilts toward the outer peripheral side from the center in the axial direction toward the two outer sides in the axial direction. As a result, foreign matter such as wear debris of the connecting rubber 16 generated by the sliding contact between the opposing inner surfaces 48a and 48b of the slit 40 is easily discharged to the outside through the tapered shape of these opposing inner surfaces 48a and 48b. In particular, the opposing inner surfaces 48a and 48b are repeatedly displaced and deformed by the vibration input in the left and right directions, thereby effectively exerting the function of discharging foreign matter. It should be noted that the central portion in the circumferential direction of the facing inner surface 48 a on the inner peripheral side of the slit 40 is formed of the stopper rubber 46 , and the facing inner surface 48 b on the outer peripheral side of the slit 40 is formed of the buffer rubber layer 44 .

[0117] The radial width dimension of the slit 40 is smaller than the distance from the front end of the bulging portion 32 of the inner shaft member 12 to the outer tube member 14, preferably smaller than half of the radial distance between the cylindrical portion 26 of the inner shaft member 12 and the outer tube member 14, and more preferably smaller than 1 / 4 of the radial distance between the cylindrical portion 26 and the outer tube member 14. It should be noted that the circumferential end portions of the slit 40 are respectively formed to be approximately semicircular when viewed in the front-rear direction. Therefore, the circumferential end portions of the slit 40 are respectively formed to be narrowed in the radial direction toward the circumferential outer side.

[0118] A friction reducing portion may also be provided in the slit 40. The friction reducing portion reduces friction resistance when the opposing inner surfaces 48a and 48b of the slit 40 are in sliding contact, thereby suppressing wear of the connecting rubber 16. It should be noted that the friction reducing portion may be, for example, a lubricant layer covering at least one of the opposing inner surfaces 48a and 48b, or a sponge-like foamed body inserted between the opposing inner surfaces 48a and 48b.

[0119] The bushing 10 having the structure as described above is arranged at the end of the connecting rod connecting the body and the bogie of the railway vehicle, and the inner shaft member 12 and the outer cylinder member 14 are mounted on each side of the body or the bogie and the connecting rod. Specifically, for example, in the bushing 10, the outer cylinder member 14 is pressed and fixed to the mounting cylinder parts provided at both ends of the connecting rod, and the inner shaft member 12 is bolted to the body or the bogie using the bolt holes 24, thereby connecting the body or the bogie and the connecting rod in a vibration-proof manner. When the bushing 10 is mounted on the connecting rod, the bushing 10 may be provided only on one side of the connecting rod, but is preferably provided at both ends of the connecting rod.

[0120] When the bushing 10 is mounted on a railway vehicle, the vibration in the axial direction of the connecting rod, that is, the left-right direction, is input as a main load between the inner shaft member 12 and the outer cylinder member 14. Here, the spring constant of the bushing 10 changes greatly in a region where the relative displacement amount in the left-right direction between the inner shaft member 12 and the outer cylinder member 14 is small and in a region where the relative displacement amount in the left-right direction between the inner shaft member 12 and the outer cylinder member 14 is large.

[0121] That is, in the small displacement region A where the relative displacement amount (deflection) between the inner shaft member 12 and the outer cylinder member 14 in the left-right direction is small, Figure 5 The inclination angle of the load-deflection curve shown becomes smaller, and the spring constant is set small. This is probably because, in the small displacement area A, the opposing inner surfaces 48a and 48b of the slit 40 are kept separated, and the shear spring of the rubber arm 42 and the rubber arm 42 becomes dominant in the spring characteristics of the bushing 10.

[0122] Both ends of the slit 40 in the circumferential direction extend outward from the bulging portion 32 to both upper and lower outer sides, and the entire front end surface 34 of the bulging portion 32 is arranged toward the slit 40. Therefore, in the small displacement area A, the connecting rubber 16 is not easily compressed in the left-right direction between the front end surface 34 of the bulging portion 32 and the facing surface of the inner circumferential surface of the outer tube member 14, and the soft spring characteristics of the shear spring based on the rubber arm portion 42 and the rubber arm portion 42 can be obtained.

[0123] In the bushing 10, the circumferential width dimension of the rubber arm portion 42 between the slits 40 and the slits 40 is formed to be smaller than the circumferential length dimension of the slits 40. By forming the left-right width dimension of the rubber arm portion 42 small, the shear spring constant of the rubber arm portion 42 is small, which can advantageously achieve Figure 5 Low spring characteristics in the small displacement area A.

[0124] In addition, the bulging portions 32, 32 of the inner shaft member 12 protrude in the radial direction orthogonal to the rubber arm portions 42, 42, and the fixing surfaces of the rubber arm portions 42, 42 in the inner shaft member 12 are formed as flat surfaces 36, 36. As a result, the free lengths of the rubber arm portions 42, 42 in the radial direction are ensured to be long with excellent space efficiency, and the shear spring constants of the rubber arm portions 42, 42 are set to be smaller, so that the low spring characteristics in the small displacement region A can be more advantageously achieved.

[0125] On the other hand, in the large displacement region B where the relative displacement amount (deflection) between the inner shaft member 12 and the outer cylinder member 14 in the left-right direction is larger than that in the small displacement region A, Figure 5 The inclination angle of the load-deflection curve shown becomes larger, and the spring constant is set larger. This is probably because, in the large displacement region B, the opposing inner surfaces 48a and the opposing inner surfaces 48b of the slit 40 abut against each other, and the stopper rubber 46 of the connecting rubber 16 covering the front end surface 34 of the bulging portion 32 abuts against the inner surface of the outer tube member 14 via the buffer rubber layer 44 and is compressed, so that the compression spring of the stopper rubber 46 becomes dominant in the spring characteristics of the bushing 10. In the present embodiment, the inner peripheral surface of the outer tube member 14 is covered by the buffer rubber layer 44, so that the knocking sound when the front end surface 34 of the bulging portion 32 covered by the stopper rubber 46 abuts against the inner peripheral surface of the outer tube member 14 is reduced by the buffer rubber layer 44.

[0126] In the bushing 10, the bulge 32 is provided in the axial center portion of the fixed mounting portion 20 of the inner shaft member 12, and the two end portions of the fixed mounting portion 20 are formed into cylindrical portions 26 having a smaller diameter in the left-right direction than the bulge 32 and the forming portion of the bulge 32. Thus, the rubber volume can be ensured at the axial ends of the connecting rubber 16 where distortion due to deformation is easily concentrated, and the durability of the connecting rubber 16 can be improved. In particular, in the present embodiment, the axial end face of the connecting rubber 16 is formed into a cone, so that the free surface area of ​​the axial end face of the connecting rubber 16 is ensured to be large, and the durability of the connecting rubber 16 is improved more effectively. Moreover, in Figure 3 In the longitudinal section shown, the bulge portion 32 is formed into an arc-shaped cross-section with a tapered front end toward the upper or lower side of the protruding front end, whereby the surface of the bulge portion 32 is inclined in the same direction as the axial surface of the connecting rubber 16. Therefore, even if the axial end surface of the connecting rubber 16 is formed into a tapered shape, it is easy to ensure the wall thickness of the connecting rubber 16 on both axial outer sides of the bulge portion 32.

[0127] exist Figure 4In the cross section shown, the front end surface 34 of the bulging portion 32 is formed in an arc shape extending with a substantially constant curvature as a whole, and is connected to the upper and lower side surfaces by forming a corner 38. As a result, the thickness dimension of the stopper rubber 46 covering the front end surface 34 of the bulging portion 32 is substantially constant in the entire circumferential direction, and the hard spring characteristics of the compression spring based on the stopper rubber 46 can be achieved with good space efficiency.

[0128] The radial width of the slit 40 is substantially constant in the middle portion in the circumferential direction and narrows at both ends in the circumferential direction. Thus, in the large displacement region B, the opposing inner surfaces 48a and 48b of the slit 40 abut against each other as a whole, and the slit 40 substantially disappears, which advantageously exhibits high spring characteristics.

[0129] It should be noted that in Figure 5 In the curve diagram representing the spring characteristics, the area where the relative displacement amount between the inner shaft member 12 and the outer cylinder member 14 in the left-right direction is less than 3b is the small displacement area A, and the area where the relative displacement amount between the inner shaft member 12 and the outer cylinder member 14 in the left-right direction is 3b or more is the large displacement area B. Therefore, in the bushing 10 of the present embodiment, the inner shaft member 12 and the outer cylinder member 14 are displaced by about 3b in the left-right direction, whereby the opposing inner surfaces 48a and 48b of the slit 40 abut against each other. However, the size of the displacement amount (deflection) that becomes the boundary between the small displacement area A and the large displacement area B is not particularly limited and can be appropriately set according to the required spring characteristics.

[0130] Inputs other than the vibration load in the left-right direction may also act on the bushing 10 mounted on the railway vehicle. For example, sometimes the inner shaft member 12 and the outer cylinder member 14 are tilted and displaced relative to each other in the left-right direction by input in the left-right prying direction. In this case, Figure 3 As shown, the front end surface 34 of the bulge 32 is formed into an arc shape with the center of the inner shaft member 12 as the center of curvature. Therefore, when the inner shaft member 12 and the outer tube member 14 are pried and displaced to the left and right, compared with bulges with other cross-sectional shapes such as trapezoidal cross-sections, the compression of the connecting rubber 16 of the bulge 32 is suppressed, and a low spring characteristic can be obtained.

[0131] exist Figure 6 , Figure 7 , a bushing 50 for railway vehicles is shown as a second embodiment of the present invention. The bushing 50 has a structure in which a pair of slits 52, 52 are formed in the connecting rubber 16. It should be noted that in the following description, the same reference numerals are given in the drawings to substantially the same components and parts as those of the first embodiment, and the description thereof is omitted.

[0132] The slit 52 of this embodiment is longer in the circumferential direction than the slit 40 of the first embodiment, and the circumferential ends of the pair of slits 52, 52 are close to each other. The portion between the circumferential ends of the pair of slits 52, 52 in the connecting rubber 16 is formed as a predetermined cutting portion 54, a predetermined cutting portion 54 with a thin wall in the circumferential direction. The predetermined cutting portion 54 extends along the entire axial direction of the connecting rubber 16, separates the slits 52, 52 from each other in the circumferential direction, and connects the inner shaft member 12 and the outer cylinder member 14 to each other in the vertical direction. The circumferential thickness dimension of the predetermined cutting portion 54 of this embodiment is the smallest at the center in the radial direction, for example, it can be a constant thickness dimension in the entire radial direction, or it can be the thinnest at the inner circumferential end or the outer circumferential end.

[0133] In the bushing single-piece state before assembling the bushing 50 to the railway vehicle, as shown in FIG. Figure 6 , Figure 7 As shown, the predetermined cutting portion 54 connects the inner shaft member 12 and the outer tube member 14 to each other. On the other hand, when the bushing 50 is used in a state in which it is assembled to a railway vehicle, the predetermined cutting portion 54 is cut in the circumferential direction, and the connecting rubber 16 is separated into an inner peripheral rubber 56 on the inner peripheral side than the slit 52 and the cutting position of the predetermined cutting portion 54, and an outer peripheral rubber 58 (buffer rubber layer 44) on the outer peripheral side. Therefore, when the bushing 50 is used in a state in which it is assembled to a railway vehicle, the connecting rubber 16 does not connect the inner shaft member 12 and the outer tube member 14, and the inner shaft member 12 and the outer tube member 14 are independent of each other. However, the inner shaft member 12 and the outer tube member 14 are installed on each side of the body and the bogie of the railway vehicle, and therefore are also relatively positioned after the predetermined cutting portion 54 is cut.

[0134] Regarding the predetermined cutting portion 54, for example, it can be cut with a cutter after the bushing 50 is assembled to the railway vehicle, or the predetermined cutting portion 54 can be automatically broken without the need for a cutting operation by inputting a load during use of the bushing 50. If the predetermined cutting portion 54 is cut during the cutting process, the cut state can be stabilized, and stable vibration-proof characteristics, improved reliability, etc. can be achieved. In addition, if the cutting process is omitted and the predetermined cutting portion 54 is broken by inputting a load, the number of operation processes can be reduced. It should be noted that, in the case where the predetermined cutting portion 54 is automatically broken by the load input during use, it is preferably broken immediately after the start of use. For example, it can also be broken after a constant period of use. The timing of the break is not particularly limited.

[0135] In the present embodiment, the slits 52, 52 are formed at the outer peripheral end of the connecting rubber 16, extending in the circumferential direction along the outer tube member 14, and the predetermined cutting portion 54, 54 is arranged close to the outer tube member 14. Therefore, when the predetermined cutting portion 54 is broken by the input load, the restraining force of the outer tube member 14 can be expected to stabilize the cutting mode of the predetermined cutting portion 54.

[0136] In this way, in the bushing 50 , the planned cutting portion 54 is sheared in the use state, whereby the spring constant in the small displacement region A becomes smaller, and the vibration isolation effect with respect to micro-amplitude vibration can be more effectively exerted.

[0137] It should be noted that in the structure where the connecting rubber 16 is sheared by cutting the predetermined portion 54 when the bushing 50 is in use, it is not necessary to ensure the free length of the rubber arm portion 42 in the radial direction of the rubber arm portion 42 for the purpose of low elasticity in the small displacement area A as in the first embodiment. Figure 8 As shown in the third embodiment of the railway vehicle bushing 60, even if the bulge 62 protruding toward the outer circumference is continuously provided with a constant cross-sectional shape over the entire circumference, low spring characteristics can be obtained in the small displacement region A. It should be noted that in the bushing 10 of the first embodiment, the bulge 62 provided over the entire circumference can be used instead of the pair of bulges 32, 32.

[0138] exist Fig. 9 , Fig.10 , a bushing 70 for railway vehicles is shown as a fourth embodiment of the present invention. The bushing 70 has a structure in which an intermediate member 72 extending in the circumferential direction between the inner shaft member 12 and the outer cylinder member 14 in the radial direction is fixedly mounted to the connecting rubber 16 .

[0139] The intermediate member 72 is composed of a pair of plate-like members 74, 74. The plate-like member 74 is bent in an arc shape and extends in the circumferential direction, and is formed to be less than half a circle in the circumferential direction. The pair of plate-like members 74, 74 are arranged opposite to each other on both sides of the left and right directions of the pair of slits 40, 40, and are spaced from each other in the circumferential direction. The rubber arm portion 42 of the connecting rubber 16 of this embodiment is formed to extend radially (up and down directions) between the slits 40, slits 40 and the plate-like members 74, and the plate-like members 74 in each circumferential direction. It should be noted that the pair of plate-like members 74, 74 are symmetrically arranged opposite to each other in the same shape and size. Thus, the pair of plate-like members 74, 74 can be used as a common component. However, the pair of plate-like members can also be formed in different shapes from each other, for example, the plate-like member of one side can be longer in the circumferential length than the plate-like member of the other side, and the circumferential length of the plate-like member of one side is more than half a circle.

[0140] The plate-like member 74 extends and protrudes to both outer sides of the circumferential direction than the bulging portion 32, and is located at a position closer to the inner side of the circumferential direction than the slit 40. However, the size relationship between the circumferential length dimensions of the plate-like member 74 and the slit 40 is not particularly limited, and the plate-like member 74 may extend and protrude to the outer side of the circumferential direction than the slit 40. It can be seen from this that the entire circumferential direction of the plate-like member 74 does not necessarily have to be adjacent to the slit 40, as long as at least a portion of the circumferential direction is adjacent. Similarly, the entire axial direction of the plate-like member 74 does not necessarily have to be adjacent to the slit 40, as long as at least a portion of the axial direction is adjacent.

[0141] In the present embodiment, the circumferential ends of the slit 40 formed in a substantially semicircular arc shape when viewed in the axial direction are located at positions protruding outwardly from the plate-like member 74 in the circumferential direction, but the circumferential ends of the slit 40 may also be located inwardly from the circumferential ends of the plate-like member 74. In this case, thick-walled rubber that fills the radial gap between the circumferential ends of the slit 40 and the plate-like member 74 can be formed on the outer peripheral surface of the plate-like member 74, and the influence of the rubber on the vibration-proof characteristics does not need to be considered.

[0142] A pair of plate-like members 74, 74 are fixedly mounted on the connecting rubber 16 at positions adjacent to the inner peripheral side of each slit 40. The plate-like member 74 extends in the circumferential direction concentrically with the slit 40, and constitutes the wall portion of the inner peripheral side of the slit 40. The outer peripheral surface of the plate-like member 74 may be exposed in the slit 40, or may be covered by a thin-walled cover rubber. In the case of being covered by the cover rubber, the cover rubber is formed to be thin to such an extent that the influence on the spring characteristics of the bushing 10 can be ignored. Therefore, in the present embodiment, the opposing inner surface 48a of the slit 40 is substantially constituted by the plate-like member 74.

[0143] like Fig.10 As shown, the plate-like member 74 protrudes from the axial end surface of the connecting rubber 16. The plate-like member 74 is formed to have substantially the same axial length as the outer tube member 14, and may protrude axially outward from the outer tube member 14 or may be located axially inward from the outer tube member 14.

[0144] The plate-like members 74 and 74 are arranged on the inner peripheral side of the slits 40 and 40, and thus the radial thickness dimension of the stopper rubber 46 covering the front end surface 34 of each bulging portion 32 is formed to be smaller than that of the first embodiment. In this way, the intermediate member 72 composed of the plate-like members 74 and 74 is arranged between the slits 40 and 40 and the bulging portions 32 and 32 in the radial direction, thereby reducing the radial thickness dimension of the stopper rubber 46 and 46 without increasing the radial width dimension of the slits 40 and 40 and the protruding height dimension of the bulging portions 32 and 32 in the left and right directions, and the spring constant of the large displacement area B can be set larger. It should be noted that it is not necessary to increase the protruding height dimension of the bulging portions 32 and 32 in the left and right directions, so that the low spring characteristics with respect to the prying input and the torsion input can be maintained, and an effective vibration isolation effect with respect to the input in the prying direction and the torsion direction can be obtained.

[0145] In addition, in the inner shaft member 12 of the bushing 70 for railway vehicles including the intermediate member 72 (a pair of plate-shaped members 74 , 74 ), the bulging portions 32 , 32 can also be omitted.

[0146] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific description. For example, the bulging parts may be provided at a plurality of locations spaced apart from each other in the axial direction in the fixing and mounting part of the connecting rubber in the inner shaft member.

[0147] The side surface of the bulge is not limited to a flat surface, and can be composed of a front end surface and a continuously extended curved surface. In short, the cross section of the portion where the bulge is formed (a cross section orthogonal to the central axis of the inner shaft member) can be formed into an ellipse with the protruding direction of the bulge being the major axis direction.

[0148] In addition, the specific shape of the bulge is not particularly limited, and for example, a bulge having a quadrilateral longitudinal section (a section parallel to the central axis of the inner shaft member and including the central axis) can be used. If the bulge having a quadrilateral longitudinal section as described above is used, the connecting rubber (stopper rubber) fixedly mounted on the front end surface of the bulge can be formed into a thin wall in a wider range in the axial direction, making it easier to achieve a harder spring characteristic in a large displacement region.

[0149] The radial width of the slit may vary in the circumferential direction. For example, the spring characteristics can be adjusted by making the two circumferential end portions, which are difficult to be filled with the connecting rubber when the inner surface of the slit abuts, narrower than the central portion. In addition, a pair of slits may be formed in different shapes and sizes, thereby achieving different spring characteristics on both sides of the radial direction.

[0150] The predetermined cutting portion 54 shown in the second embodiment does not necessarily have to be provided over the entire axial length, and the predetermined cutting portion 54 may be provided locally in the axial direction, thereby being expected to simplify the cutting operation and facilitate the fracture due to load input. It should be noted that when the predetermined cutting portion 54 is provided locally in the axial direction, its axial position is not particularly limited. For example, when the predetermined cutting portion 54 is sheared before use by the cutting operation, it is preferably provided near the axial end portion to facilitate cutting. When the predetermined cutting portion 54 is fractured by the load input during use, it is preferably provided in the axial center portion in consideration of the balance before cutting.

[0151] The intermediate member 72 (plate-shaped member 74, plate-shaped member 74) shown in the fourth embodiment is provided concentrically with the outer cylinder member 14. For example, the intermediate member 72 may be provided non-concentrically with the outer cylinder member 14 so that the curvature of the outer peripheral surface (opposing inner surface 48a on the inner peripheral side of the slit 40) of the intermediate member 72 and the curvature of the inner peripheral surface (opposing inner surface 48b on the outer peripheral side of the slit 40) of the outer cylinder member 14 are substantially the same. According to this, when a large load is input, the opposing inner surfaces 48a and 48b of the slit 40 are substantially simultaneously abutted in a wider range in the circumferential direction, so that the spring constant of the large displacement region B can be increased more significantly than the spring constant of the small displacement region A.

Claims

1. A cylindrical vibration isolating device (10, 50, 60, 70) for railway vehicles, wherein an inner shaft member (12) and an outer cylinder member (14) are connected to each other via a cylindrical connecting rubber (16), wherein: The connecting rubber (16) is fixedly mounted on the outer peripheral surface of the inner shaft member (12) and the inner peripheral surface of the outer cylinder member (14). A pair of slits (40, 40, 52, 52) extending in the circumferential direction and penetrating in the axial direction are formed on both sides of the radial direction of the inner shaft member (12) at the outer peripheral end of the connecting rubber (16). The circumferential length of each of the slits (40, 52) is formed to be longer than the circumferential length of the connecting rubber (16) between the pair of slits (40, 40, 52, 52). A bulging portion (32, 62) that protrudes toward the outer periphery of the pair of slits (40, 40, 52, 52) is partially provided in the axial direction at the fixing and mounting portion (20) of the connecting rubber (16) in the inner shaft member (12).

2. The cylindrical vibration isolating device (10, 50, 60, 70) according to claim 1, wherein: The slits (40, 52) are formed in an expanded shape that becomes wider in the radial direction toward the openings on both sides in the axial direction.

3. The cylindrical vibration isolating device (10, 50, 60, 70) according to claim 1 or 2, wherein: The inner peripheral surface of the outer tube member (14) is covered with a buffer rubber layer (44, 58) which is formed integrally with the connecting rubber (16) and constitutes the wall surface on the outer peripheral side of the slit (40, 52).

4. The cylindrical vibration isolating device (10, 50, 60, 70) according to claim 1 or 2, wherein: The cylindrical vibration isolating device (10, 50, 60, 70) is provided with a pair of bulging portions (32, 32, 62, 62) protruding toward both sides in the radial direction toward the pair of slits (40, 40, 52, 52).

5. The cylindrical vibration isolating device (10, 50, 70) according to claim 4, wherein: In a radial direction orthogonal to the protruding direction of the pair of bulging portions (32, 32), the outer peripheral surface of the fixing and mounting portion (20) of the connecting rubber (16) in the inner shaft member (12) is composed of a pair of flat surfaces (36, 36).

6. The cylindrical vibration isolating device (10, 50, 60, 70) according to claim 1 or 2, wherein: The bulging portion (32, 62) is formed into an arc-shaped longitudinal cross-sectional shape.

7. The cylindrical vibration isolating device (10, 70) according to claim 1 or 2, wherein: At the axial position where the bulge (32) is provided, the circumferential length of a 90-degree region (X) around the center axis of the inner shaft member (12) in the radial direction where the pair of slits (40, 40) are located is formed to be longer than the circumferential length of a 90-degree region (Y) around the center axis of the inner shaft member (12) in the radial direction orthogonal to the radial direction where the pair of slits (40, 40) are located.

8. The cylindrical vibration isolating device (10, 50, 60, 70) according to claim 1 or 2, wherein: A wear reducing portion for suppressing wear of the connecting rubber (16) is provided in the slit (40, 52).

9. The cylindrical vibration isolating device (50, 60) according to claim 1 or 2, wherein: In the connecting rubber (16), a portion located between the pair of slits (52, 52) in the circumferential direction forms a predetermined cutting portion (54), and when the connecting rubber (16) is installed in a railway vehicle for use, the predetermined cutting portion (54) is cut off, and the connecting rubber (16) is separated into an inner peripheral rubber (56) fixedly mounted on the inner shaft member (12) and an outer peripheral rubber (58) fixedly mounted on the outer cylinder member (14).

10. The cylindrical vibration isolating device (70) according to claim 1 or 2, wherein: An intermediate member (72) extending in the circumferential direction between the inner shaft member (12) and the outer cylinder member (14) in the radial direction is fixedly mounted on the connecting rubber (16).

11. The cylindrical vibration isolating device (70) according to claim 10, wherein: The intermediate member (72) is arranged adjacent to the inner periphery of the slit (40).

12. The cylindrical vibration isolating device (70) according to claim 11, wherein: The intermediate member (72) is composed of a pair of plate-shaped members (74, 74) arranged on both sides of the same radial direction as the pair of slits (40, 40).

13. A cylindrical vibration isolating device (50, 60) for railway vehicles, wherein an inner shaft member (12) and an outer cylinder member (14) are connected to each other via a cylindrical connecting rubber (16), wherein: The connecting rubber (16) is fixedly mounted on the outer peripheral surface of the inner shaft member (12) and the inner peripheral surface of the outer cylinder member (14). A pair of slits (52, 52) extending in the circumferential direction and penetrating in the axial direction are formed on both sides of the radial direction of the inner shaft member (12) so as to clamp the connecting rubber (16). In the connecting rubber (16), a portion located between the pair of slits (52, 52) in the circumferential direction forms a predetermined cutting portion (54), and when the connecting rubber (16) is installed in a railway vehicle for use, the predetermined cutting portion (54) is cut off, and the connecting rubber (16) is separated into an inner peripheral rubber (56) fixedly mounted on the inner shaft member (12) and an outer peripheral rubber (58) fixedly mounted on the outer cylinder member (14).

14. A cylindrical vibration isolator (70) for railway vehicles, wherein an inner shaft member (12) and an outer cylinder member (14) are connected to each other via a cylindrical connecting rubber (16), wherein: The connecting rubber (16) is fixedly mounted on the outer peripheral surface of the inner shaft member (12) and the inner peripheral surface of the outer cylinder member (14). A pair of slits (40, 40) extending in the circumferential direction and penetrating in the axial direction are formed on both sides of the radial direction of the inner shaft member (12) at the outer peripheral end of the connecting rubber (16). An intermediate member (72) extending circumferentially between the inner shaft member (12) and the outer cylinder member (14) in the radial direction is fixedly mounted on the connecting rubber (16). The intermediate member (72) is arranged adjacent to the inner periphery of the slit (40).

15. The cylindrical vibration isolating device (70) according to claim 14, wherein: The intermediate member (72) is composed of a pair of plate-shaped members (74, 74) arranged on both sides of the same radial direction as the pair of slits (40, 40).

16. The cylindrical vibration isolating device (70) according to claim 14 or 15, wherein: The curvature of the outer peripheral surface of the intermediate member (72) is the same as the curvature of the inner surface of the outer peripheral side of the slit (40).

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