Cuff unit

Abstract

Cuff unit, comprising: a cuff (250) having a small diameter portion (400) formed on one side, a large diameter portion (410) formed on the other side, and a pleated portion (210) formed between the small diameter portion (400) and the large diameter portion (410); a bushing (220) formed integrally with an inner circumference or an outer circumference in a circumferential direction and having a predetermined thickness; and a band (230) formed in the bushing (220) along the circumferential direction of the bushing (220) and having a substantially annular shape, wherein the bushing (220) is molded on the large diameter portion (410) of the sleeve (250), and wherein the band (230) is formed by an overmolding process on the inside of the bushing (220), wherein the band (230) has a band eyelet (240) protruding from an outer periphery of the band (230), wherein a groove portion (280) is formed in the sleeve (250) and the bushing (220) such that the strap eyelet (240) is exposed out of the sleeve (250) through the groove portion (280), and wherein the bushing (220) is formed along an inner circumference of the large diameter portion (410) of the sleeve (250).

Description

[0001] The invention relates to a boot unit mounted on a power transmission device of a vehicle to prevent internal lubricant from leaking and foreign matter from entering.

[0002] A boot is a cover made of rubber material to cover a section of a master cylinder, wheel cylinder, cable, electrical wire, or connector, and can be applied to a constant velocity joint of a vehicle.

[0003] The boot unit for a vehicle is applied to a section connected to a constant velocity joint or a connecting section of rotating shafts to prevent oil / grease leakage or contaminants from entering.

[0004] Generally, a boot assembly for a vehicle includes a boot sandwiched between shafts to maintain airtightness and a band for securing the boot. In this configuration, one side of the boot is secured by one band, while the other side of the boot is secured by another band.

[0005] However, one disadvantage is that the cuff and band are provided separately and the band must be precisely mounted on the cuff after the cuff is installed.

[0006] Furthermore, by covering the band on an outer side of the boot, an outer diameter of the boot may be enlarged, and the boot assembly may be interfered with by adjacent components. Furthermore, the boot and band may become separated or detached, thus deteriorating the overall durability and sealing performance.

[0007] JP H10-267 127 A describes a cuff unit comprising a cuff and a band formed in the cuff.

[0008] JP H11-108 186 A, WO 2006 / 066 603 A1 and JP 2006-226 337 A each describe a cuff unit comprising a cuff, a bushing and a band formed in the bushing.

[0009] The invention provides a boot unit in which durability and sealing performance are improved by improving the engagement structure of a boot and a band, reducing the outer diameter of the boot unit, and preventing interference with adjacent components and separation or detachment of the boot and the band.

[0010] This is achieved according to the invention by a cuff unit according to the features of claim 1 or 4. Advantageous further developments are described in the subclaims.

[0011] According to one aspect of the invention, a boot unit includes a boot having a small diameter portion formed on one side, a large diameter portion formed on the other side, and a fold portion formed between the small diameter portion and the large diameter portion, a bushing formed integrally with an inner periphery or an outer periphery in a circumferential direction and having a predetermined thickness, and a band formed in the bushing along the circumferential direction of the bushing and having a substantially ring shape.

[0012] The band has a band eyelet protruding from an outer periphery of the band, and a groove portion is formed in the collar and the bushing such that the band eyelet is exposed from the collar through the groove portion.

[0013] The sleeve and bushing may be chemically integrally formed or bonded together. The bushing is formed along an inner circumference of the large-diameter portion of the sleeve.

[0014] A cover portion may be formed integrally with the bushing to protect an end surface of the large-diameter portion of the boot. The bushing is molded onto the large-diameter portion of the boot, and the band is formed on the inside of the bushing by insert molding.

[0015] According to another aspect of the invention, a boot unit comprises a bushing having a one-sided outer periphery formed on one side thereof, an other-sided outer periphery formed on the other side thereof, and a step surface formed between the one-sided outer periphery and the other-sided outer periphery, wherein a distance of the other-sided outer periphery from a central axis is smaller than a distance of the one-sided outer periphery from the central axis, a boot having a small-diameter portion formed on one side, a large-diameter portion formed on the other side, and a fold portion formed between the small-diameter portion and the large-diameter portion, wherein the large-diameter portion has a diameter larger than that of the small-diameter portion,and an inner circumference formed integrally with the one-side outer circumference, the step surface, and the other-side outer circumference of the bushing, and a band configured such that the sleeve contacts the bushing.

[0016] The boot unit further includes an end cover portion formed integrally with an end portion of the bushing so as to extend in a radial direction, and an outer cover portion formed integrally with an end portion of the end cover portion so as to correspond to the other outer periphery of the bushing, wherein the band contacts an outer periphery of the outer cover portion to fix the outer cover portion to an outer periphery of the boot and fix the boot to the other outer periphery of the bushing.

[0017] The bushing is molded with the large diameter portion of the boot by an insert molding process in which the large diameter portion of the boot is inserted into a mold and a molding material is injected or poured into the mold to form the bushing.

[0018] According to various aspects of the invention, a band is arranged on the inside of a bushing, which is effective to reduce the maximum diameter of a sleeve unit.

[0019] Similarly, when a bushing is molded by an insert molding process on an inner circumference of a large diameter portion of a boot, a band is inserted into the mold to reduce the risk of a band being separated by an external influence.

[0020] Furthermore, the bonding force between a band and a bushing is enhanced to improve overall durability and strength. Furthermore, a boot and a bushing are chemically bonded to improve the bonding force between them, and a boot, a bushing, and a band can be treated as a single, integrally molded component.

[0021] The invention is explained in more detail with reference to the drawing. The drawing shows: Fig. 1 is a schematic perspective view of a sleeve unit according to an exemplary embodiment of the invention on a power transmission unit; Fig. 2 is a perspective view of the cuff unit according to the exemplary embodiment of the invention; Fig. 3 a longitudinal section of the cuff unit according to the exemplary embodiment of the invention; Fig. 4 is a perspective view of a cuff of the cuff unit according to the exemplary embodiment of the invention; Fig. 5 is a perspective view of a bushing and a band of the cuff unit according to the exemplary embodiment of the invention; Fig. 6 is a perspective view of a bushing and band of a boot assembly being engaged by an overmolding process; Fig. 7 is a flowchart for explaining a method for manufacturing a cuff unit which is not an embodiment of the invention; Fig. 8 is a longitudinal section of a cuff unit according to another exemplary embodiment of the invention; Fig. 9 is a perspective view of a bushing of the sleeve unit according to the other exemplary embodiment of the invention; Fig. 10 is a perspective sectional view of an engagement structure of the bushing and a sleeve of the sleeve unit according to the other exemplary embodiment of the invention; Fig. 11 is a partial section of the cuff unit according to the other exemplary embodiment of the invention, with which a band is engaged; and Fig. 12 is a partial cross-sectional view of the cuff unit according to the other exemplary embodiment of the invention, to which a band is attached.

[0022] With reference to Fig. 2, a cuff unit 200 according to an embodiment of the invention comprises a cuff 250, a bushing 220 and a band 230.

[0023] A pleated portion 210 is formed between a small diameter portion 400 and a large diameter portion 410 of the sleeve 250, and the bushing 220 having a predetermined thickness is formed on an inner periphery of the large diameter portion 410.

[0024] Furthermore, the band 230 is formed in the bushing 220 in a circumferential direction of the bushing 220. A groove portion 280 is formed on one side of the large-diameter portion 410 of the collar 250, and the band 230 is exposed through the groove portion 280. A band eyelet 240 protrudes from an outer periphery of the band 230 and is formed corresponding to the groove portion 280.

[0025] An operator uses the strap eyelet 240 of the strap 230 to attach the bushing 220 to an outer periphery of a power transmission device, for example, by any suitable or conventional methods, a detailed description of which is omitted.

[0026] A mounting protrusion 290 is convexly formed on an inner periphery of the bushing 220 and is inserted into a groove corresponding to the mounting protrusion 290, so that the boot unit 200 is securely fastened. An opening 295 is formed in the mounting protrusion 290, which provides a spring force when the mounting protrusion 290 is mounted and reduces the overall weight.

[0027] With reference to Fig. 3, the bushing 220 is formed with a predetermined thickness on an inner periphery of the large-diameter portion 410 of the collar 250, and the band 230 is disposed on the inside of the collar 250. Specifically, the band 230 is disposed inside the bushing 220 except for the groove portion 280.

[0028] The inner periphery of the large-diameter portion 410 of the collar 250 and the bushing 220 are substantially integrally formed. It is appreciated that the large-diameter portion 410 of the collar 250 and the bushing 220 may be monolithically formed. In particular, they have a chemically resistant structure by being integrally molded. Furthermore, the band 230 is fixedly disposed within the bushing 220 by an insert molding process when the bushing 220 is insert molded. The insert molding process (method) consists in inserting the large-diameter portion 410 of the collar 250 into a mold and injecting or pouring the molding material into the mold to form the bushing 220.

[0029] A cover portion 300 is formed on the bushing 220 to cover an outer end surface of the large-diameter portion 410 of the collar 250. The cover portion 300 securely holds the connection of the collar 250 and the bushing 220 and protects an outer end portion of the collar 250. Here, the cover portion 300 may be formed continuously or intermittently along a circumferential direction of the bushing 220.

[0030] With reference to Fig. 4, the cuff 250 includes the small-diameter portion 400, the pleat portion 210, and the large-diameter portion 410 arranged in a longitudinal direction, and the large-diameter portion 410 is cut to form the groove portion 280. The cuff 250 may be formed, for example, by a blow molding process, including any suitable conventional blow molding processes.

[0031] With reference to the Fig. 5 and Fig. 6, a metallic plate member having a predetermined length and width is bent, the two ends of the plate member are joined together to form the substantially annular band 230, and the band eyelet 240 protrudes outward from one side of the outer circumference.

[0032] The band 230 is placed in a mold used to form the bushing 220 so that the band 230 is disposed within the bushing 220. The insert molding process consists in inserting the large-diameter portion 410 of the sleeve 250 and the band 230 into a mold, and injecting or pouring molding material into the mold to form the bushing 220. Further, the band eyelet 240 is exposed to the outside through the groove portion 280.

[0033] Further, as described above, the convex mounting projection 290 is formed on an inner periphery of the bushing 220, and the cover portion 300 is formed at the one lateral end portion along a circumferential direction.

[0034] According to the invention, the band 230 is arranged on the inside of the bushing 220 so that the maximum or total diameter of the sleeve 250 is reduced.

[0035] If a metallic band were disposed on an outer periphery of the bushing 220 or the collar, the maximum or total diameter of the collar 250 would be increased by the band eyelet 240. By disposing the band 230 on the inner side of the bushing 220, the total diameter of the collar 250 is equal to the diameter of the large diameter portion 410 of the collar 250 and is not increased by the band eyelet 240.

[0036] Furthermore, when the bushing 220 is molded by insert molding on an inner periphery of the large-diameter portion 410 of the boot 250, the band 230 is inserted into a mold to reduce the risk that the band 230 may be separated from the bushing 220 due to external influences. Furthermore, the bonding force between the band 230 and the bushing 220 is improved, and the overall durability and stability can also be improved.

[0037] Furthermore, when the bushing 220 is formed on an inner periphery of the large diameter portion 410 of the collar 250, the collar 250 and the bushing 220 are substantially chemically integrally formed to improve the joining or bonding force, and the collar 250, the bushing 220, and the band 230 can be handled or considered as one component that is integrally and / or monolithically formed.

[0038] With reference to Fig. 7, S700 is a step in which the cuff 250 including the small diameter portion 400, the large diameter portion 410, and the pleat portion 210 is formed by, for example, blow molding.

[0039] S710 is a step in which the bushing 220 is formed, for example, by insert molding, on the large-diameter portion 410 of the collar 250. Here, S720 may be performed during S710. That is, the band 230 is inserted into a mold when the bushing 220 is molded by insert molding.

[0040] For convenience of explanation, the above steps S700, S710, and S720 are arranged sequentially. However, the order of these steps does not necessarily have to be sequential, and in some cases, these steps may be performed arbitrarily or simultaneously.

[0041] For illustrative purposes, the bushing 220 and the band 230 are described above as being attached to the large diameter portion 410 of the sleeve 250. In various other embodiments, the bushing 220 and the band 230 may be attached to the small diameter portion 400 of the sleeve 250 using the same method.

[0042] Furthermore, it is explained above that the bushing 220 is molded together with the sleeve 250 by means of an overmolding process. In various other embodiments, the sleeve 250 may have a predetermined thickness such that the sleeve 250 can perform the function of the bushing. In such embodiments, the band 230 is arranged on the inside of the thickened portion of the sleeve 250.

[0043] In various embodiments of the invention, the sleeve 250 and the bushing 220 may be made of rubber, plastic or resin material, and the band may be made of metallic material.

[0044] With reference to Fig. 1, a power transmission device includes a constant velocity joint 130, a band 120, a boot 110, and a drive shaft 100. The boot assembly includes the boot 110 and the band 120.

[0045] The constant velocity joint 130 utilizes a joint structure and a ball to transmit torque from the drive shaft 100 to a rear axle shaft. The structure of the constant velocity joint 130 is well known, so a detailed description thereof will be omitted.

[0046] With reference to Fig. 8, a cuff unit 200 according to another exemplary embodiment of the invention includes a cuff 250, a bushing 220, and a band 230.

[0047] The boot 250 is arranged along a central axis 800, and the bushing 220 contacts an outer periphery and an inner periphery of the large-diameter portion 410 of the boot 250. The bushing 220 and the boot 250 are molded, for example, by insert molding, to be integrally formed. Accordingly, separation of the bushing 220 and the boot 250 is prevented. Further, the band 230 closely contacts the bushing 220 and the boot 250 to securely fix them to the outer periphery of a constant velocity joint.

[0048] With reference to the Fig. 9 and Fig. 10, an engagement structure of the bushing 220, the collar 250, and the band 230 is further described.

[0049] The bushing 220 has an outer periphery that contacts an inner periphery of the large diameter portion 410 of the sleeve 250, and the bushing 220 has a one-side outer periphery 900 and an other-side outer periphery 920. In the Fig. 8 and Fig. 9, the one-side outer circumference 900 is formed on a left side, and the other-side outer circumference 920 is formed on a right side.

[0050] A stepped surface 910 is formed between the one-side outer periphery 900 and the other-side outer periphery 920. The stepped surface 910 can be easily varied to achieve various configurations, such as an inclined surface with a predetermined angle, an arcuate surface with a predetermined curved shape, and a vertical surface with a vertical shape.

[0051] The one-side outer circumference 900 and the other-side outer circumference 920 have predetermined distances from the central axis 800, and the distance between the one-side outer circumference 900 and the central axis 800 is greater than the distance between the other-side outer circumference 920 and the central axis 800.

[0052] Further, an end cover portion 930 protrudes from an outer periphery in a radial direction at the other end portion of the bushing 220, and an outer cover portion 940 is formed to extend on one side of the one end portion of the end cover portion 930. The inner periphery of the outer cover portion 940 and the other outer periphery 920 are spaced apart by a predetermined distance.

[0053] The bushing 220 having the above-described structure and the large-diameter portion 410 of the boot 250 are molded, for example, by an insert molding process so as to be integrally joined to each other, and the structure as shown in Fig. 10 is completed.

[0054] With reference to Fig. 10, a large diameter portion 410 of the sleeve 250 contacts the one-side outer periphery 900, the step surface 910, the other-side outer periphery 920, and the outer cover portion 940 of the bushing 220 so as to be integrally formed therewith.

[0055] Specifically, the large diameter portion 410 of the collar 250 is securely connected or bonded to the bushing 220 via the step surface 910 and further connected or bonded to the inner periphery of the outer cover portion 940 to prevent separation thereof.

[0056] With reference to the Fig. 11 and Fig. 12, the large diameter portion 410 of the sleeve 250 is joined or bonded to the bushing 220 by an insert molding process, and the band 230 is brought into contact with the outer cover portion 940 of the bushing 220.

[0057] As in Fig. 11, the band 230 of the bushing 220 is engaged with the outer cover portion 940. As shown in Fig. As shown in Figure 12, when the band 230 is tightened, the band 230 presses against the outer cover portion 940 of the bushing 220 to securely fasten the large-diameter portion 410 of the collar 250. Further, the large-diameter portion 410 of the collar 250 securely contacts the bushing 220.

[0058] As shown in the drawing, the inner circumference of the band 230 contacts the outer cover portion 940 of the socket 220, so that the band 230 is securely attached to the socket 220 without direct contact with the sleeve 250.

[0059] For ease of description and accurate definition of the appended claims, the terms "left", "right", "inside", "outside", etc. are used to describe features of the exemplary embodiments with respect to their positions in the figures.

Claims

[1] Cuff unit, comprising: a cuff (250) having a small diameter portion (400) formed on one side, a large diameter portion (410) formed on the other side, and a pleated portion (210) formed between the small diameter portion (400) and the large diameter portion (410); a bushing (220) formed integrally with an inner circumference or an outer circumference in a circumferential direction and having a predetermined thickness; and a band (230) formed in the bushing (220) along the circumferential direction of the bushing (220) and having a substantially annular shape, wherein the bushing (220) is molded on the large diameter portion (410) of the sleeve (250), and wherein the band (230) is formed by an overmolding process on the inside of the bushing (220), wherein the band (230) has a band eyelet (240) protruding from an outer periphery of the band (230), wherein a groove portion (280) is formed in the sleeve (250) and the bushing (220) such that the strap eyelet (240) is exposed out of the sleeve (250) through the groove portion (280), and wherein the bushing (220) is formed along an inner circumference of the large diameter portion (410) of the sleeve (250). [2] The sleeve assembly of claim 1, wherein the sleeve (250) and the bushing (220) are chemically integrally formed or bonded together. [3] The boot unit according to claim 1, wherein a cover portion (300) is formed integrally with the bushing (220) to protect an end portion surface of the large diameter portion (410) of the boot (250). [4] Cuff unit, comprising: a bushing (220) having a one-sided outer periphery (900) formed on one side thereof, an other-sided outer periphery (920) formed on the other side thereof, and a step surface (910) formed between the one-sided outer periphery (900) and the other-sided outer periphery (920), wherein a distance of the other-sided outer periphery (920) from a central axis (800) is smaller than a distance of the one-sided outer periphery (900) from the central axis (800); a sleeve (250) having a small diameter portion (400) formed on one side, a large diameter portion (410) formed on the other side, and a fold portion (210) formed between the small diameter portion (400) and the large diameter portion (410), the large diameter portion (410) having a diameter larger than that of the small diameter portion (400) and an inner periphery formed integrally with the one-side outer periphery (900), the step surface (910), and the other-side outer periphery (920) of the bushing (220); a band (230) configured such that the sleeve (250) contacts the socket (220); an end cover portion (930) formed integrally with an end portion of the bushing (220) so as to extend in a radial direction; and an outer cover portion (940) formed integrally with an end portion of the end cover portion (930) so as to correspond to the other outer periphery (920) of the bushing (220), wherein the bushing (220) is molded with the large diameter portion (410) of the sleeve (250) by an insert molding process in which the large diameter portion (410) of the sleeve (250) is inserted into a mold and a molding material is injected or poured into the mold to form the bushing (220), and wherein the band (230) contacts an outer periphery of the outer cover portion (940) to secure the outer cover portion (940) to one outer periphery of the sleeve (250) and to secure the sleeve (250) to the other outer periphery (920) of the bushing (220).

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