Method for manufacturing vibration isolation device

Abstract

Provided is a method for manufacturing a vibration isolation device in which a resin outer cylinder and a bracket cylinder can be firmly attached to each other, and the durability of which is improved.　The method for manufacturing a vibration isolation device is a method for obtaining a vibration isolation device in which a resin outer cylinder 4, to which an inner member 2 is connected via an elastic member 3, is attached to the inside of a bracket cylinder 5. This manufacturing method includes: a press-fitting step for press-fitting the outer cylinder 4 into the bracket cylinder 5; and a caulking step for caulking an axial one end section 5a of the bracket cylinder 5 toward a recess 4d, formed in the outer peripheral surface F41 of the outer cylinder 4, so that the axial one end section 5a of the bracket cylinder 5 is inserted into the recess 4d, after the press-fitting step.

Description

Manufacturing method of vibration isolation device

[0001] The present invention relates to a method for manufacturing an anti-vibration device.

[0002] A known conventional method for manufacturing a vibration-damping device involves expanding one axial end of a resin outer cylindrical member (outer cylindrical member) of a vibration-damping bushing that constitutes part of the vibration-damping device radially outward to form an expanded diameter portion, and then fitting a metal sleeve (bracket cylindrical member) onto the outer cylindrical member through the expanded diameter portion (see, for example, Patent Document 1). According to this manufacturing method, when the bracket cylindrical member is fitted onto the outer cylindrical member, an engaging bent portion formed between the expanded diameter portion and a reduced diameter portion of the outer cylindrical member that is continuous with the expanded diameter portion engages with an inner corner portion (inner end in the direction perpendicular to the axis) of the metal sleeve. This conventional manufacturing method for a vibration-damping device can thus obtain a vibration-damping device in which the outer cylindrical member is prevented from slipping out of the metal sleeve.

[0003] Japanese Patent Application Laid-Open No. 2008-223920

[0004] However, with the above-described conventional manufacturing method for an anti-vibration device, when assembling the outer tube and the bracket tube, it is necessary to forcibly insert the expanded diameter portion of the outer tube, i.e., one axial end of the outer tube, into the inside of the bracket tube. In other words, in this case, it is necessary to forcibly deform one axial end of the outer tube, which is expanded radially outward, radially inward. Therefore, there is room for improvement in the durability of the outer tube of the anti-vibration device obtained using the above-described conventional manufacturing method for an anti-vibration device.

[0005] The object of the present invention is to provide a method for manufacturing an anti-vibration device that enables a resin outer tube and a bracket tube to be firmly attached during the manufacture of the anti-vibration device, and improves the durability of the anti-vibration device.

[0006] (1) A method for manufacturing a vibration-damping device according to the present invention is a method for obtaining a vibration-damping device in which a resin outer tube, to which an inner member is connected via an elastic member, is attached to the inside of a bracket tube, and includes a press-fitting step of press-fitting the outer tube into the inside of the bracket tube, and a crimping step of, after the press-fitting step, crimping one axial end of the bracket tube inward toward a recess formed on the outer peripheral surface of the outer tube so that the end is inserted into the recess. The method for manufacturing a vibration-damping device according to the present invention enables the resin outer tube and the bracket tube to be firmly attached during manufacturing of the vibration-damping device, and improves the durability of the vibration-damping device.

[0007] (2) In the method for manufacturing a vibration-damping device described in (1) above, it is preferable that in the crimping step, the end portion of the bracket tube in the axial direction on one side is crimped inward toward the recess formed in the outer tube so that at least one of the inner end and the outer end of the end face on one axial side of the bracket tube comes into contact with the side surface on one axial side of the recess formed in the outer tube. In this case, a vibration-damping device that is effective in preventing the outer tube from coming off from the other axial side of the bracket tube can be obtained.

[0008] (3) In the method for manufacturing a vibration-damping device described in (2) above, it is preferable that in the crimping step, the end of one axial side of the bracket tube is crimped inward toward the recess so that both the inner and outer ends of the end face of the one axial side of the bracket tube come into contact with the side surface of the one axial side of the recess formed in the outer tube. In this case, an effective vibration-damping device can be obtained by preventing the outer tube from coming off from the other axial side of the bracket tube.

[0009] (4) In the method for manufacturing a vibration-damping device described in (2) above, in the crimping step, the end of one axial side of the bracket tube can be crimped inward toward the recess so that only the inner end of the end face of the bracket tube on one axial side contacts the side surface of the recess on one axial side of the outer tube. In this case, a vibration-damping device that is effective in preventing the outer tube from coming off from the other axial side of the bracket tube can be obtained by simple crimping.

[0010] (5) In the method for manufacturing a vibration-damping device according to any one of (1) to (4), in the crimping step, the one axial end of the bracket tube can be crimped inward toward the recess so that the inner peripheral surface of the one axial end of the bracket tube is in surface contact with the other axial side surface of the recess formed in the outer tube. In this case, the outer tube and the bracket tube can be attached more firmly.

[0011] (6) In the method for manufacturing a vibration-damping device according to any one of (1) to (5) above, in the crimping step, one axial end of the bracket tube can be crimped over the entire circumferential direction of the bracket tube. In this case, the outer tube and the bracket tube can be attached more firmly.

[0012] (7) In the method for manufacturing a vibration-damping device according to any one of (1) to (5) above, in the crimping step, one axial end of the bracket tube can be crimped at a plurality of locations around the circumferential direction of the bracket tube. In this case, a lightweight vibration-damping device can be obtained.

[0013] According to the present invention, a method for manufacturing an anti-vibration device can be provided that enables a resin outer tube and a bracket tube to be firmly attached during the manufacture of the anti-vibration device, and improves the durability of the anti-vibration device.

[0014] 1 is a cross-sectional view schematically showing an anti-vibration device obtained by a method for manufacturing an anti-vibration device according to one embodiment of the present invention, attached to a frame as a cab mount for use in a vehicle. FIG. 2 is a cross-sectional view schematically showing an example of an anti-vibration main body prepared in a preparation step of a method for manufacturing an anti-vibration device according to one embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing an example of a bracket tube prepared together with the anti-vibration main body of FIG. 2 in the preparation step. FIG. 4 is a cross-sectional view schematically showing a state in which the anti-vibration main body has been press-fitted into the inside of the bracket tube by a press-fitting step of a method for manufacturing an anti-vibration device according to one embodiment of the present invention, which is performed subsequent to the preparation step. FIG. 5 is a cross-sectional view schematically showing a state in which one axial side end of the bracket tube is crimped inward so that the one axial side end of the bracket tube is inserted into a recess formed in the outer peripheral surface of an outer tube, in a crimping step of a method for manufacturing an anti-vibration device according to one embodiment of the present invention, which is performed subsequent to the press-fitting step. FIG. 6 is a cross-sectional view schematically showing an anti-vibration device obtained by the crimping step, in which both the inner end and the outer end of the one axial end face of the bracket tube are in contact with one axial side surface of a recess formed in the outer tube. 7 is a cross-sectional view showing an enlarged region X of Fig. 6. Fig. 7 is a cross-sectional view showing, in a crimping step of a method for manufacturing an anti-vibration device according to another embodiment of the present invention, a state in which one axial end portion of the bracket tube is crimped inward toward a recess formed in an outer tube so that only the inner end of one axial end face of the bracket tube comes into contact with one axial side surface of the recess formed in the outer tube. Fig. 8 is a half cross-sectional view showing, in a crimping step of a method for manufacturing an anti-vibration device according to another embodiment of the present invention, a state in which one axial end portion of the bracket tube is crimped inward toward a recess formed in the outer tube so that only the inner end of the one axial end face of the bracket tube comes into contact with one axial side surface of the recess. Fig. 8 is a half cross-sectional view showing, in a

[0015] A method for manufacturing an anti-vibration device according to one embodiment of the present invention (hereinafter simply referred to as "this manufacturing method") will be described below with reference to the drawings. In the following description, the anti-vibration device obtained by this manufacturing method is a cab mount. The cab mount supports the cab (driver's compartment) relative to the frame (chassis). However, to simplify the description, the meanings of terms will be defined as follows:

[0016] Here, "axial direction" refers to the extension direction of the central axis O of the vibration isolation device (hereinafter also simply referred to as "axis O"). Here, "one side in the axial direction" refers to the side located on the lower side when the vibration isolation device is installed in a direction extending in the vertical direction, and is also simply referred to as the "lower side" or "bottom." Furthermore, "the other side in the axial direction" refers to the side located on the upper side when the vibration isolation device is installed in a direction extending in the vertical direction, and is also simply referred to as the "upper side" or "top."

[0017] Furthermore, the term "radial direction" refers to a direction perpendicular to the axial direction (also referred to as "axis-perpendicular direction"). Here, the term "radial inner side" (also referred to as "axis-perpendicular inner side") refers to the side closer to the axis O. The term "radial outer side" (also referred to as "axis-perpendicular outer side") refers to the side farther from the axis O.

[0018] As shown in Figure 1, an anti-vibration device 1 obtained by a method for manufacturing an anti-vibration device according to one embodiment of the present invention is a vibration-damping device in which an outer tube 4 made of resin, to which an inner member 2 is connected via an elastic member 3, is attached to the inside of a bracket tube 5.

[0019] In this example, the vibration isolation device 1 is cab-mounted, as described above. The vibration isolation device 1 is fixed to the frame 6 by using fixing means 8. In this example, the frame 6 is formed with an opening A6 through which the bracket tube 5 passes in the vertical direction (axial direction). Also, in this example, the upper end 5b of the bracket tube 5, which will be described later, is placed on the periphery of the opening A6 of the frame 6. Furthermore, in this example, the upper end 5b of the bracket tube 5 is fixed to the frame 6 by the fixing means 8. In this way, the vibration isolation device 1 is fixed to the frame 6 by using the fixing means 8.

[0020] In the vibration-damping device 1, the inner member 2 includes a tubular portion 2a extending in the axial direction and a support plate 2b fixed to the upper end of the tubular portion 2a. In this example, a cab 7 is attached to the upper surface of the support plate 2b. In this example, the tubular portion 2a is a cylindrical portion. In addition, in the vibration-damping device 1, the elastic member 3 is coupled (more specifically, in this example, fixed) to the outer peripheral surface of the tubular portion 2a of the inner member 2 and to the lower surface of the support plate 2b of the inner member 2. In addition, in this example, the inner member 2 includes a stopper plate 2c fixed to the lower end of the tubular portion 2a.

[0021] Furthermore, in the vibration-damping device 1, the outer cylinder 4 is a cylindrical member with a flange. A recess 4d is formed on the outer peripheral surface F41 of the outer cylinder 4. In this example, the recess 4d is an annular recess formed around the entire circumferential direction around the axis O. In this example, the recess 4d is a wedge-shaped recess (with a V-shaped cross section) recessed radially inward.

[0022] In this example, the outer cylinder 4 includes a lower end portion 4a, an upper end portion 4b, and a body portion 4c connecting the lower end portion 4a and the upper end portion 4b. In this example, the recess 4d is formed on the outer peripheral surface F41 of the lower end portion 4a of the outer cylinder 4. In this example, the upper end portion 4b forms an annular flange that extends annularly in the circumferential direction around the axis O. The annular flange extends radially outward from the body portion 4c.

[0023] Furthermore, in the vibration-damping device 1, the elastic member 3 is coupled (more specifically, fixed in this example) to the upper surface of the upper end portion 4b of the outer cylinder 4, together with the inner peripheral surface F42 of the outer cylinder 4. As a result, the inner member 2 and the outer cylinder 4 are elastically coupled by the elastic member 3.

[0024] In this example, the inner circumferential surface F42 of the outer cylinder 4 includes a reduced diameter surface F42a that slopes radially inward as it extends downward. In this example, the reduced diameter surface F42a forms part of the inner circumferential surface F42 of the lower end portion 4a of the outer cylinder 4. The reduced diameter surface F42a prevents the elastic member 3 from falling off the lower end (one axial side) of the outer cylinder 4. However, the reduced diameter surface F42a can be omitted. That is, the inner circumferential surface F42 of the outer cylinder 4 can be, for example, a straight surface extending in the axial direction when viewed in axial cross section, as shown in FIG. 1 .

[0025] In the vibration-damping device 1, the bracket tube 5 is also a cylindrical member with a flange. In the vibration-damping device 1, the bracket tube 5 has a lower end 5a, an upper end 5b, and a body portion 5c that connects the lower end 5a and the upper end 5b. In this example, the lower end 5a of the bracket tube 5 is a crimped portion that is crimped radially inward (inward in the direction perpendicular to the axis) toward the recess 4d of the outer tube 4. In this example, the lower end 5a of the bracket tube 5 is a cylindrical lower end that extends circumferentially around the axis O over the entire circumference. Therefore, in this example, the lower end 5a of the bracket tube 5 is crimped over the entire circumference of the bracket tube 5.

[0026] In this example, the upper end 5b of the bracket tube 5 forms an annular flange extending circumferentially around the axis O. The annular flange extends radially outward beyond the body 5c. This allows the upper end 5b of the bracket tube 5 to be placed on the peripheral edge of the opening A6 of the frame 6. In this example, the bracket tube 5, together with the lower end 4a of the outer tube 4, has its lower end 5a passing through the opening A6 formed in the frame 6, thereby placing the upper end 5b of the bracket tube 5 on the peripheral edge of the opening A6 of the frame 6. Furthermore, in this example, a through hole h5 for attaching a fixing means 8 is formed in the upper end 5b of the bracket tube 5 at a position that aligns with the through hole h6 formed in the frame 6 when the bracket tube 5 is placed on the frame 6. This allows the bracket tube 5 to be fixed to the frame 6 by the fixing means 8. Examples of the fixing means 8 include fastening elements such as bolts and nuts.

[0027] Furthermore, in this example, an outer cylinder 4 is disposed inside the bracket cylinder 5. In this example, at least the outer peripheral surface F41 of the body portion 4c of the outer cylinder 4 is press-fitted into the inner peripheral surface F52 of the bracket cylinder 5.

[0028] In this example, the upper end 4b of the outer tube 4 is placed on the upper end 5b of the bracket tube 5. In this example, the upper end 4b of the outer tube 4 extends radially outward relative to the body portion 5c. Meanwhile, a curved portion 5g is formed between the body portion 5c and the upper end 5b of the bracket tube 5. The curved portion 5g expands radially outward from the body portion 5c toward the upper end 5b. As a result, in this example, a gap S1 is formed between the outer tube 4 and the bracket tube 5.

[0029] The vibration isolation device 1 elastically supports the cab 7 relative to the frame 6. As a result, when the cab 7 moves downward and sinks relative to the frame 6, the vibration isolation device 1 can elastically absorb this sinking. In addition, when the cab 7 moves upward and rises relative to the frame 6, the vibration isolation device 1 can elastically absorb this rising. In particular, the rising of the cab 7 is restricted by the stopper plate 2c of the inner member 2 coming into contact with the underside of the elastic member 3.

[0030] Next, a specific example of a method for manufacturing a vibration-damping device according to this embodiment will be described with reference to the drawings. The method for manufacturing a vibration-damping device according to this embodiment is a method for manufacturing a vibration-damping device, which is configured to obtain a vibration-damping device 1 in which a resin outer cylinder 4, to which an inner member 2 is connected via an elastic member 3, is attached to the inside of a bracket cylinder 5.

[0031] The manufacturing method of the vibration-damping device according to this embodiment includes a preparation step of preparing an outer tube 4 to which an inner member 2 is connected via an elastic member 3, and a bracket tube 5 for forming the bracket tube 5.

[0032] In the preparation step of this manufacturing method, the vibration-isolating body 10 shown in FIG. 2 and the bracket tube 5 shown in FIG. 3 are prepared.

[0033] 2 is a cross-sectional view schematically showing an example of an anti-vibration body 10 prepared in the preparation step of this manufacturing method. In this embodiment, the anti-vibration body 10 includes an inner member 2, an elastic member 3, and an outer cylinder 4. However, in this example, the inner member 2 does not have a stopper plate 2c. In other words, the anti-vibration body 10 used in this manufacturing method is composed of the inner member 2, the elastic member 3, and the outer cylinder 4. This allows the anti-vibration body 10 to be easily press-fitted into the inner circumferential surface F52 formed on the inside of the bracket cylinder 5 without having to consider interference between the stopper plate 2c and the bracket cylinder 5.

[0034] In addition, in the vibration-damping body 10, the recess 4d formed in the outer cylinder 4 has a lower side surface (side surface on one axial side) 4d1 and an upper side surface (side surface on the other axial side) 4d2 in an axial cross-sectional view, as shown in Fig. 2. Specifically, as shown in Fig. 2, the lower side surface 4d1 and the upper side surface 4d2 of the recess 4d form a wedge shape (V-shaped cross-section) tapering radially inward in an axial cross-sectional view.

[0035] More specifically, the lower end of the lower side surface 4d1 of the recess 4d is continuous with the outer peripheral surface F41 of the outer cylinder 4, and the lower side surface 4d1 of the recess 4d slopes radially inward as it extends upward from the outer peripheral surface F41 of the outer cylinder 4. The upper end of the upper side surface 4d2 of the recess 4d is continuous with the outer peripheral surface F41 of the outer cylinder 4, and the upper side surface 4d2 of the recess 4d slopes radially inward as it extends downward from the outer peripheral surface F41 of the outer cylinder 4. Additionally, the upper end of the lower side surface 4d1 of the recess 4d is continuous with the lower end of the upper side surface 4d2 of the recess 4d. This results in the recess 4d being shaped like a wedge (V-shaped cross section) recessed radially inward. The recess 4d can be formed, for example, by cutting, or can be molded together with the outer cylinder 4.

[0036] The outer cylinder 4 of the vibration-isolating body 10 is made of resin for the purpose of reducing weight, etc., i.e., it is formed from a resin material. Examples of the resin material include synthetic resins such as engineering plastics and fiber-reinforced plastics. Examples of engineering plastics include PA (polyamide) 6 and PA (polyamide) 66. Examples of fiber-reinforced plastics include PA66-GF30. The elastic member 3 of the vibration-isolating body 10 is formed from an elastic material. Examples of the elastic material include rubber and resin.

[0037] In addition, in the vibration-damping body 10 used in this manufacturing method, the configurations of the inner member 2, elastic member 3 and outer tube 4 are the same as the configurations of the inner member 2, elastic member 3 and outer tube 4 of the vibration-damping device 1, except that it does not have a stopper plate 2c.

[0038] FIG. 3 is a cross-sectional view showing a schematic example of a bracket tube 5 prepared together with the vibration-isolating body 10 of FIG. 2 in the preparation step of this manufacturing method.

[0039] As shown in Fig. 3, the configuration of the bracket tube 5 used in this embodiment is the same as the configuration of the bracket tube 5 of the vibration-damping device 1, except that the lower end 5a of the bracket tube 5 is not crimped. However, as shown in Fig. 3, the lower end 5a of the bracket tube 5 used in this manufacturing method, in an axial cross-sectional view, forms a straight tubular portion extending in the axial direction together with the body portion 5c of the bracket tube 5 before the lower end 5a is crimped. Therefore, as shown in Fig. 3, the inner peripheral surface F52 of the bracket tube 5 used in this manufacturing method is a straight inner peripheral surface extending in the axial direction before the lower end 5a of the bracket tube 5 is crimped in an axial cross-sectional view.

[0040] The bracket tube 5 is made of metal, such as iron or aluminum (including aluminum alloys).

[0041] Furthermore, this manufacturing method includes a press-fitting step of press-fitting the outer cylinder 4 into the bracket cylinder 5 after the above-mentioned preparation step.

[0042] In the press-fitting step of this manufacturing method, the outer peripheral surface F41 of the outer cylinder 4 of the vibration-damping main body 10 in Fig. 2 is press-fitted into the inner peripheral surface F52 of the bracket cylinder 5 in Fig. 3. This firmly fixes the vibration-damping main body 10 and the bracket cylinder 5 to each other. Fig. 4 schematically shows the state in which the vibration-damping main body 10 has been press-fitted into the bracket cylinder 5 by the press-fitting step, which is performed following the preparation step described above.

[0043] Furthermore, this manufacturing method includes a crimping process in which, after the press-fitting process, one axial end portion (5a) of the bracket tube 5 is crimped inward toward the recess 4d so that the one axial end portion (5a) of the bracket tube 5 is inserted into the recess 4d formed on the outer surface F41 of the outer tube 4.

[0044] In the crimping process of this manufacturing method, the lower end 5a of the bracket tube 5 is crimped radially inward (inward in the direction perpendicular to the axis) toward the recess 4d so that the lower end 5a of the bracket tube 5 is inserted into the recess 4d formed in the lower end 4a of the outer tube 4.

[0045] 5 shows a schematic diagram of the crimping process, which follows the above-described press-fitting process, in which the lower end 5a of the bracket tube 5 is crimped radially inward so that the lower end 5a is inserted into the recess 4d formed in the outer peripheral surface F41 of the outer tube 4. As shown in Fig. 5, the lower end 5a of the bracket tube 5 is crimped into the recess 4d of the outer tube 4. This more firmly fixes the vibration-damping main body 10 and the bracket tube 5 to each other.

[0046] Examples of crimping include "press crimping," which locally crimps the lower end 5a of the bracket tube 5 in the circumferential direction of the lower end 5a, and "rolling crimping," which crimps the lower end 5a of the bracket tube 5 in the circumferential direction by using a pressure roller.

[0047] In the crimping process of this manufacturing method, the axial end portion (5a) of the bracket tube 5 can be crimped inward toward the recess 4d so that at least one of the inner end (5e2) and the outer end (5e1) of the axial end face (5e) of the bracket tube 5 comes into contact with the axial side surface (4d1) of the recess 4d formed in the outer tube 4.

[0048] As shown in Figure 6, in the crimping process of this manufacturing method, one axial end portion (5a) of the bracket tube 5 is crimped radially inward toward the recess 4d so that both the inner end (5e2) and the outer end (5e1) of the axial end face (5e) of the bracket tube 5 come into contact with the axial side surface (4d1) of the recess 4d formed in the outer tube 4.

[0049] Here, FIG. 7 shows an enlarged view of the region X in FIG.

[0050] 7, in the crimping process according to this embodiment, the lower end 5a of the bracket tube 5 is crimped radially inward so that both the inner end (radially inner end) 5e2 and the outer end (radially outer end) 5e1 of the lower end face 5e of the bracket tube 5 come into contact with the lower side surface 4d1 of the recess 4d formed in the outer tube 4. In this case, as shown in FIG. 7, the entire lower end face 5e of the bracket tube 5 fits inside the recess 4d formed in the outer tube 4.

[0051] Furthermore, as shown in FIG. 7, in the crimping step of this manufacturing method, the lower end surface 5e of the crimped bracket tube 5 is in surface contact with the lower side surface 4d1 of the recess 4d formed in the outer tube 4.

[0052] In addition, in the crimping process of this manufacturing method, one axial end (5a) of the bracket tube 5 is crimped radially inward toward the recess 4d so that the inner surface (F52) of the one axial end (5a) of the bracket tube 5 is in surface contact with the other axial side surface (4d2) of the recess 4d formed in the outer tube 4.

[0053] 7 , in the crimping process according to this embodiment, the lower end 5 a of the bracket tube 5 is crimped radially inward so that the inner circumferential surface F52 of the lower end 5 a of the bracket tube 5 comes into surface contact with the upper side surface 4 d2 of the recess 4 d formed in the outer tube 4. In this case, the outer tube 4 is more firmly fixed to the bracket tube 5.

[0054] As described above, according to this manufacturing method, the vibration-isolating body 10 and the bracket tube 5 can be firmly fixed to each other by performing the crimping process following the press-fitting process.

[0055] Furthermore, this manufacturing method includes, after the crimping step, a stopper plate attachment step of attaching a stopper plate 2c to the lower end of the cylindrical portion 2a of the inner member 2. The stopper plate 2c can be fixed to the cylindrical portion 2a by press-fitting, fastening, welding, etc. In this way, the vibration-damping device 1 as shown in FIG.

[0056] In the stopper plate attachment step, if the stopper plate 2c has a diameter (width) that allows it to pass through the inside of the bracket tube 5, the stopper plate 2c can be manufactured in advance as part of the vibration-damping main body 10. In this case, the stopper plate attachment step can be omitted from this manufacturing method.

[0057] As described above, the manufacturing method for an anti-vibration device according to this embodiment includes a press-fitting step of press-fitting the outer tube 4 of the anti-vibration body 10 into the bracket tube 5, and a crimping step of, after the press-fitting step, crimping the lower end 5a of the bracket tube 5 inward toward the recess 4d of the outer tube 4. According to this manufacturing method, the outer tube 4 of the anti-vibration body 10 and the bracket tube 5 can be firmly attached to each other by simply press-fitting the outer tube 4 into the bracket tube 5 and then crimping the lower end 5a of the bracket tube 5 into the recess 4d formed in the outer tube 4. Furthermore, when attaching the resin outer tube 4 and the bracket tube by forcibly deforming the end of the outer tube that has expanded radially outward, as in the conventional manufacturing method for an anti-vibration device described above, there is a concern that cracks or breaks may occur in the resin outer tube. In contrast, with the manufacturing method for an anti-vibration device according to this embodiment, it is not necessary to attach the resin outer tube and the bracket tube by forcibly deforming the end of the outer tube, which has a diameter expanded radially outward, as in the conventional manufacturing method for an anti-vibration device described above. Therefore, with the manufacturing method for an anti-vibration device according to this embodiment, the resin outer tube 4 and the bracket tube 5 can be firmly attached during manufacturing of the anti-vibration device 1, and the durability of the anti-vibration device 1 is improved.

[0058] As mentioned above, in this manufacturing method, in the crimping process, it is preferable to crimp the lower end portion 5a of the bracket tube 5 inward so that at least one of the inner end 5e2 and the outer end 5e1 of the lower end face 5e of the bracket tube 5 contacts the lower side surface 4d1 of the recess 4d formed in the outer tube 4.

[0059] In the vibration-damping device 1 obtained by this manufacturing method, the lower end 5a of the bracket tube 5 is crimped inside the recess 4d formed in the outer tube 4, and at least one of the inner end 5e2 and the outer end 5e1 of the lower end 5a of the bracket tube 5 is in contact with the lower side surface 4d1 of the recess 4d formed in the outer tube 4. In this case, even if an upward force is applied to the outer tube 4 due to, for example, the lifting of the carburetor 7, at least one of the inner end 5e2 and the outer end 5e1 of the lower end surface 5e of the bracket tube 5 is in contact with the lower side surface 4d1 of the recess 4d formed in the outer tube 4, so that the outer tube 4 can be prevented from slipping out of the upper end opening of the bracket tube 5. Therefore, this manufacturing method makes it possible to obtain a vibration-damping device 1 that is effective in preventing the outer tube 4 from slipping out from the upper side (the other axial side) of the bracket tube 5.

[0060] Furthermore, when at least one of the inner end 5e2 and the outer end 5e1 of the lower end surface 5e of the bracket tube 5 is crimped so as to contact the lower side surface 4d1 of the recess 4d formed in the outer tube 4, no gap is formed between the lower side surface 4d1 of the recess 4d formed in the outer tube 4 and the lower end surface 5e of the bracket tube 5. Therefore, even when a large load that separates them in the axial direction is applied to at least one of the outer tube 4 or the bracket tube 5, the outer tube 4 and the bracket tube 5 will not separate in the axial direction, as would be the case if the lower end 5a of the bracket tube 5 were simply fitted into the recess 4d formed in the outer tube 4. Therefore, the manufacturing method for an anti-vibration device according to this embodiment makes it possible to prevent the generation of abnormal noise that may be caused by an axial collision between the outer tube 4 and the bracket tube 5.

[0061] In particular, in the crimping process of this manufacturing method, the lower end 5a of the bracket tube 5 is crimped inward so that both the inner end 5e2 and the outer end 5e1 of the lower end face 5e of the bracket tube 5 come into contact with the lower side surface 4d1 of the recess 4d formed in the outer tube 4. In this case, even if an upward force is applied to the outer tube 4 due to, for example, the cab 7 rising up, both the inner end 5e2 and the outer end 5e1 of the lower end face 5e of the bracket tube 5 come into contact with the lower side surface 4d1 of the recess 4d formed in the outer tube 4, which makes it possible to more effectively prevent the outer tube 4 from slipping out of the upper end opening of the bracket tube 5. Therefore, this manufacturing method makes it possible to obtain an anti-vibration device 1 that is effective in preventing the outer tube 4 from slipping out from above the bracket tube 5.

[0062] Additionally, in the crimping step of this manufacturing method, the lower end 5a of the bracket tube 5 is crimped inward so that the inner peripheral surface F52 of the lower end 5a of the bracket tube 5 is in surface contact with the upper side surface 4d2 of the recess 4d formed in the outer tube 4. In this case, the outer tube 4 and the bracket tube 5 can be attached more firmly.

[0063] Furthermore, in the crimping step of this manufacturing method, the lower end 5a of the bracket tube 5 is crimped over the entire circumferential direction of the bracket tube 5. In this case, the outer tube 4 and the bracket tube 5 can be attached more firmly.

[0064] According to another embodiment of the method for manufacturing an anti-vibration device of the present invention, in the crimping process, the axial end portion (5a) of the bracket tube 5 can be crimped inward toward the recess (4d) so that only the inner end (5e2) of the axial end face (5e) of the bracket tube 5 comes into contact with the axial side surface (4d1) of the recess 4d formed in the outer tube 4.

[0065] In the crimping process according to the other embodiment described above, the lower end 5a of the bracket tube 5 is crimped radially inward toward the recess 4d so that only the inner end 5e2 of the lower end face 5e of the bracket tube 5 is inserted into the recess 4d formed in the lower end 4a of the outer tube 4.

[0066] Figure 8 schematically shows a state in which the lower end 5a of the bracket tube 5 is crimped in the crimping step according to the other embodiment so that only the inner end 5e2 of the lower end face 5e of the bracket tube 5 contacts the lower side surface 4d1 of the recess 4d formed in the outer tube 4. As shown in Figure 8, when the lower end 5a of the bracket tube 5 is crimped, only the inner end 5e2 of the lower end face 5e of the bracket tube 5 contacts the lower side surface 4d1 of the recess 4d formed in the outer tube 4. In this case, a vibration-damping device 1 that is effective in preventing the outer tube 4 from coming off from above the bracket tube 5 can be obtained by simple crimping, which simply brings the inner end 5e2 of the lower end face 5e of the bracket tube 5 into contact with the lower side surface 4d1 of the recess 4d formed in the outer tube 4.

[0067] The shape of the recess 4d formed in the outer cylinder 4 is not limited to the wedge shape as described above, but may be various other shapes.

[0068] 9 is a half-sectional view schematically showing another example of an anti-vibration body 10 applicable to the method for manufacturing an anti-vibration device according to the present invention. As shown in FIG. 9, the recess 4d is a recess having a curved shape (curved cross-sectional shape) that is recessed radially inward and has a curved surface 4d4. In this example, the recess 4d is a recess whose curved surface 4d4 has a semicircular shape (semicircular cross-sectional shape).

[0069] 10 is a half-sectional view schematically showing yet another example of an anti-vibration body 10 applicable to the method for manufacturing an anti-vibration device according to the present invention. As shown in Fig. 10, the recess 4d is a polygonal recess (a polygonal cross-sectional shape having a bottom surface) that is recessed radially inward and has a bottom surface 4d3. In this example, the recess 4d is a U-shaped recess (a U-shaped cross-sectional shape) that has the bottom surface 4d3 between a lower side surface 4d1 and an upper side surface 4d2.

[0070] As described above, the shape of the recess 4d formed in the outer tube 4 is such that when the lower end 5a of the bracket tube 5 is crimped inward, the lower end 5a of the bracket tube 5 is inserted into the recess 4d formed in the outer tube 4, for example, such that at least the inner end 5e2 of the lower end face 5e of the bracket tube 5 can be inserted into the recess 4d formed in the outer tube 4 and such that the inner end 5e2 can come into contact with the recess 4d formed in the outer tube 4.

[0071] Furthermore, according to the manufacturing method of the vibration-damping device of the present invention, in yet another embodiment, in the crimping process, one axial end (5a) of the bracket tube 5 can be crimped at multiple locations around the circumference of the bracket tube 5.

[0072] FIG. 11 is a cross-sectional view showing a schematic view of another example of the bracket tube 5 applicable to the method for manufacturing an anti-vibration device according to the present invention.

[0073] In this example, the lower ends 5a of the bracket tube 5 are formed intermittently in the circumferential direction around the axis O. Specifically, the lower ends 5a of the bracket tube 5 can be formed in at least two locations. For example, if the bracket tube 5 has two lower ends 5a, the two lower ends 5a are preferably formed in positions facing each other across the axis O. Furthermore, if the bracket tube 5 has three or more lower ends 5a, the three or more lower ends 5a are preferably formed in positions equally spaced apart in the circumferential direction around the axis O. In other words, if the bracket tube 5 has two or more lower ends 5a, the two or more lower ends 5a are preferably formed in positions equally spaced apart in the circumferential direction around the axis O. In this case, the outer tube 4 and the bracket tube 5 are fixed to each other in a balanced manner in the circumferential direction around the axis O.

[0074] As described above, in yet another embodiment of the method for manufacturing an anti-vibration device according to the present invention, by using the bracket tube 5 shown in Figure 11 in the crimping step, the lower end 5a of the bracket tube 5 can be crimped at multiple locations in the circumferential direction of the bracket tube 5. In this case, multiple gaps are formed in the circumferential direction of the lower end 5a of the bracket tube 5. Therefore, in this case, a lightweight anti-vibration device 1 can be obtained.

[0075] As described above, the method for manufacturing an anti-vibration device according to the present invention can provide a method for manufacturing an anti-vibration device that can firmly attach a resin outer tube to a bracket tube during manufacturing of the anti-vibration device, and that improves the durability of the anti-vibration device.

[0076] The above merely discloses exemplary embodiments of the method for manufacturing a vibration-damping device according to the present invention, and various modifications are possible within the scope of the claims. For example, the vibration-damping device is not limited to a cab mount, as long as it is a vibration-damping device in which an outer cylinder, to which an inner member is connected via an elastic member, is attached to the inside of a bracket cylinder. For example, the vibration-damping device obtained by the method for manufacturing a vibration-damping device according to the present invention may be an engine mount, a suspension bushing, etc.

[0077] 1: Vibration-damping device, 2: Inner member, 2a: Cylindrical portion of inner member, 2b: Support plate of inner member, 2c: Stopper plate of inner member, 3: Elastic member, 4: Outer cylinder, 4a: Lower end portion of outer cylinder, 4b: Upper end portion of outer cylinder, 4c: Body portion of outer cylinder, 4d: Recess formed in outer cylinder, 4d1: Lower side surface (side surface on one side in the axial direction) of recess formed in outer cylinder, 4d2: Upper side surface (side surface on the other side in the axial direction) of recess formed in outer cylinder, 4d3: Bottom surface of recess formed in outer cylinder, 4d4: Curved surface of recess formed in outer cylinder, F41: Outer surface of outer cylinder, F42: Inner surface of outer cylinder, F42a: Diameter-reducing surface included in the inner surface of the outer cylinder, 5: Bracket cylinder, 5a: Lower end portion of bracket cylinder, 5b: Upper end portion of bracket cylinder, 5c: Body portion of bracket cylinder F52: inner peripheral surface of bracket tube, 6: frame, 7: cab, 8: fixing means, 10: vibration isolation body

Claims

1. A method for manufacturing an anti-vibration device in which a resin outer tube to which an inner member is connected via an elastic member is attached to the inside of a bracket tube, the method comprising: a press-fitting step of pressing the outer tube into the inside of the bracket tube; and a crimping step of, after the press-fitting step, crimping one axial end of the bracket tube inward toward a recess formed on the outer peripheral surface of the outer tube so that the end is inserted into the recess.

2. A method for manufacturing an anti-vibration device as described in claim 1, wherein in the crimping process, the axial end portion of the bracket tube is crimped inward toward the recess so that at least one of the inner end and outer end of the axial end face of the bracket tube contacts the axial side surface of the recess formed in the outer tube.

3. A method for manufacturing an anti-vibration device as described in claim 2, wherein in the crimping process, the axial end portion of the bracket tube is crimped inward toward the recess so that both the inner end and outer end of the axial end face of the bracket tube contact the axial side surface of the recess formed in the outer tube.

4. A method for manufacturing an anti-vibration device as described in claim 2, wherein in the crimping process, the axial end portion of the bracket tube is crimped inward toward the recess so that only the inner end of the axial end face of the bracket tube contacts the axial side surface of the recess formed in the outer tube.

5. A method for manufacturing an anti-vibration device as described in claim 2, wherein in the crimping process, the axial end of one side of the bracket tube is crimped inward toward the recess so that the inner surface of the axial end of the bracket tube is in face contact with the other axial side surface of the recess formed in the outer tube.

6. A method for manufacturing an anti-vibration device as described in claim 1, wherein in the crimping step, one axial end of the bracket tube is crimped over the entire circumferential direction of the bracket tube.

7. A method for manufacturing an anti-vibration device as described in claim 1, wherein in the crimping step, one axial end of the bracket tube is crimped at a plurality of locations around the circumference of the bracket tube.

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