JP2018115729A - Boot mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of components and man-hours by simplifying a mounting structure of a boot 1.SOLUTION: A boot 1 made of a rubber elastic body comprises: a deformable cylindrical flexible part 11; a large-diameter mounting part 12 formed at one end of the flexible part 11 and mounted to a housing 21; and a small-diameter mounting part 13 formed at the other end of the flexible part 11 and mounted to a shaft 3 extending from an inner periphery of the housing 21. The large-diameter mounting part 12 is fitted inside a mounting groove 21b formed at an end surface 21a of the housing 21, and fixed in a detachment-prevention state by a caulking part 21c formed on a peripheral wall of the mounting groove 21b. A positioning protrusion 12b brought into tight-contact with the end surface 21a of the housing 21 is formed on an inner periphery at the end of the flexible part 11 at the large-diameter mounting part 12. A seal protrusion bar brought into tight-contact with an inner face of the mounting groove 21b is formed at the large-diameter mounting part 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a boot mounting structure used as a sealing means for a constant velocity universal joint of an automobile.

  The propeller shaft of an automobile transmits the rotational force from the engine to the wheels. The constant velocity universal joint provided on the propeller shaft blocks the intrusion of muddy water from the outside and prevents the internal grease from flowing out. Sealed with boots to prevent.

  FIG. 6 shows a conventional technique. A constant velocity universal joint denoted by reference numeral 100 includes a housing (outer race) 101 formed at an end of one drive shaft (not shown), A torque transmission member 102 that is accommodated on the inner periphery and fixed to the end of the other drive shaft 103 is provided. A boot 200 is mounted between the opening of the housing 101 and the drive shaft 103.

  The boot 200 is a diaphragm made of a rubber elastic body (rubber material or a synthetic resin material having rubber-like elasticity) that can be deformed following the relative reciprocation or swinging movement of the housing 101 and the drive shaft 103. A boot-shaped main body 201 and an annular adapter 202 made of metal. The boot body 201 has a small-diameter end portion 201 a and a large-diameter end portion 201 b. The small-diameter end portion 201 a is fastened and fixed to the outer peripheral surface of the drive shaft 103 by a binding band 203, and the large-diameter end portion 201 b It is fixed by caulking to one end 202a in the axial direction.

  The other end 202b of the adapter 202 in the axial direction is tightly fitted to the outer peripheral surface of the opening end portion of the housing 101 of the constant velocity universal joint 100 via a packing 204 such as an O-ring, and is formed on the outer peripheral surface of the housing 101. The groove 101a is continuous and fixed in the circumferential direction.

Japanese Patent No. 3388923

  According to the mounting structure of the conventional boot 200 shown in FIG. 6, in addition to providing the metal adapter 202, the gap between the adapter 202 and the housing 101 is sealed with the packing 204, so that the number of parts and man-hours are large. Therefore, it is desirable to have a simple structure.

  The present invention has been made in view of the above points, and its technical problem is to simplify the boot mounting structure and reduce the number of parts and man-hours.

  In order to solve the technical problem described above, a boot mounting structure according to the present invention includes a deformable cylindrical flexible portion, a large-diameter mounting portion formed at one end of the flexible portion and attached to a housing, An attachment in which the large-diameter attachment portion of the boot made of a rubber elastic body is formed on the end surface of the housing, and the small-diameter attachment portion is formed on the other end of the flexible portion and attached to a shaft extending from the inner periphery of the housing. The housing is closely fitted in the groove and fixed in a state of being prevented from being detached by a caulking portion formed on a peripheral wall of the mounting groove, and the housing is formed on an inner peripheral surface of an end portion of the flexible portion on the large-diameter mounting portion side. A positioning projection that is in close contact with the end surface of the mounting groove is formed, and a seal protrusion that is in close contact with the inner surface of the mounting groove is formed in the large-diameter mounting portion.

  According to the boot mounting structure of the present invention, the large-diameter mounting portion of the boot is closely fitted in the mounting groove formed on the end surface of the housing and is prevented from being detached by the caulking portion. Since the large-diameter mounting portion is directly attached to the housing, the structure is simplified, the number of parts and man-hours can be reduced, and it can be provided at low cost. The mounting state of the large-diameter mounting portion can be stabilized and the sealing performance can be improved.

It is a half sectional view showing an embodiment of a boot mounting structure according to the present invention. It is principal part sectional drawing which shows the example of a shape of the large diameter attachment part of the boot in embodiment of the attachment structure of the boot concerning this invention. It is principal part sectional drawing which shows the other example of a shape of the large diameter attachment part of the boot in embodiment of the attachment structure of the boot concerning this invention. In embodiment of the boot attachment structure which concerns on this invention, it is a half cross-sectional view which shows the unattached state of a boot. In embodiment of the attachment structure of the boot concerning this invention, it is a semi-sectional view which shows the formation process of a crimping | crimped part. It is a half sectional view showing an example of the attachment structure of the boot by the prior art.

  Hereinafter, a preferred embodiment of a boot mounting structure according to the present invention will be described in detail with reference to the drawings.

  First, in FIG. 1, reference numeral 1 denotes a boot, which is formed of a rubber elastic body, and has a deformable cylindrical shape with one end having a large diameter and the other end having a small diameter, specifically, a flexible shape having a substantially funnel shape. A portion 11, a large-diameter attachment portion 12 formed at one axial end (large-diameter end) of the flexible portion 11, and an axial other end (small-diameter end) of the flexible portion 11. And a small-diameter mounting portion 13.

  The large-diameter mounting portion 12 is formed in a bowl shape whose outer periphery protrudes from the outer peripheral surface of the flexible portion 11 to the outer diameter side, and as shown in an enlarged view in FIGS. 2 and 3, the large-diameter mounting portion 12. A taper-shaped stepped surface 12 a is formed from the outer peripheral surface to the outer peripheral surface of the flexible portion 11. On the other hand, on the outer peripheral surface of the small-diameter mounting portion 13, a band mounting groove 13 a continuous in the circumferential direction for mounting the metal fastening band 14 is formed, and on the inner peripheral surface of the small-diameter mounting portion 13 in the circumferential direction. A continuous seal protrusion 13b is formed.

  Reference numeral 2 in FIG. 1 is a constant velocity universal joint provided on a propeller shaft of an automobile, and includes a housing (outer race) 21 provided at an end of one drive shaft (not shown) and the other drive. And a torque transmission member 22 that is attached to the end of the shaft 3 and accommodated in the inner periphery of the housing 21.

  An end face 21 a of the opening of the housing 21 is formed with a mounting groove 21 b that is continuous in the circumferential direction with a radial width substantially equal to that of the large-diameter mounting portion 12 of the boot 1, and the large-diameter mounting portion 12 of the boot 1. Is closely fitted in the mounting groove 21b, and the tapered step surface 12a on the outer periphery is restrained by a caulking portion 21c formed on a thin peripheral wall on the outer periphery side of the mounting groove 21b, and is fixed in a retaining state. ing.

  On the inner peripheral surface of the end portion of the flexible portion 11 of the boot 1 on the large-diameter mounting portion 12 side, a positioning projection 12b that is in close contact with the end surface 21a of the opening portion of the housing 21 in the mounting state shown in FIG. It is formed continuously in the direction. Further, as shown in an enlarged view in FIG. 2, a required number of seal protrusions 12c are formed on the inner peripheral surface of the large-diameter attachment portion 12, or as shown in an enlarged view in FIG. A required number of seal protrusions 12d are formed on the end faces of the twelve. Among these, the seal protrusion 12c shown in FIG. 2 is in close contact with the inner peripheral surface of the attachment groove 21b in a suitably compressed state by the restraining force of the caulking portion 21c in the attachment state shown in FIG. In the attached state shown in FIG. 1, the seal protrusion 12d shown in FIG. 1 is brought into close contact with the bottom surface of the attachment groove 21b in an appropriately compressed state by the restraining force of the caulking portion 21c.

  A fitting groove 3a continuous in the circumferential direction is formed at a predetermined position in the axial direction of the outer peripheral surface of the drive shaft 3 protruding from the opening of the housing 21, and the small-diameter mounting portion 13 of the boot 1 is fitted with this fitting. In a state in which the inner circumferential seal protrusion 13b is closely fitted in the groove 3a, it is fastened and fixed by a fastening band 14 wound around the band attachment groove 13a.

  In the above configuration, the boot 1 has the large-diameter mounting portion 12 fixed by crimping to the housing 21 of the constant velocity universal joint 2 and the small-diameter mounting portion 13 is fastened and fixed to the drive shaft 3. This prevents foreign matter from entering from the outside and prevents the grease for lubrication filled in the housing 21 from leaking to the outside.

  The large-diameter attachment portion 12 of the boot 1 is directly attached to the housing 2 by being fitted in an attachment groove 21b formed in the end surface 21a of the housing 21 and being restrained in a retaining state by the crimping portion 21c. Therefore, not only the adapter 202 shown in FIG. 6 described above is unnecessary, but also the seal protrusion 12c formed on the inner peripheral surface of the large-diameter mounting portion 12 or the end surface of the large-diameter mounting portion 12. Since the sealing protrusion 12d is brought into close contact with the inner surface of the mounting groove 21b in a compressed state, an excellent sealing performance is obtained, so that the packing 204 as shown in FIG. 6 is also unnecessary. Therefore, since the structure is simplified and the number of parts is reduced, it can be provided at a low cost.

  Further, when attaching the large-diameter mounting portion 12 of the boot 1 to the housing 21, first, from the unmounted state shown in FIG. 4, the large-diameter mounting portion 12 and the positioning projection 12 b of the housing 21 are arranged as shown in FIG. 5. Insert into the mounting groove 21b of the housing 21 in the axial direction until it contacts the end surface 21a of the opening. The mounting groove 21b has a radial width substantially equal to the large-diameter mounting portion 12 of the boot 1 and the thin peripheral wall 21d on the outer peripheral side of the mounting groove 21b is formed in a cylindrical shape in advance. The large-diameter mounting portion 12 can be easily inserted and is easily positioned by the positioning projection 12b. 4 and 5 show the large-diameter mounting portion 12 having the cross-sectional shape illustrated in FIG.

  Then, a thin peripheral wall 21d on the outer peripheral side of the mounting groove 21b is bent from the outer peripheral side, and is brought into pressure contact with the tapered step surface 12a of the large-diameter mounting portion 12 of the boot 1 as shown in FIG. By forming the crimped portion 21c, the large-diameter mounting portion 12 is restrained in a close fitting state in the mounting groove 21b, thereby completing the mounting operation to the housing 21. That is, since the large-diameter mounting portion 12 of the boot 1 can be inserted into the mounting groove 21b and the peripheral wall 21d of the mounting groove 21b can be caulked, it can be easily mounted with a small number of man-hours. Contributes to cost reduction.

  Then, the large-diameter mounting portion 12 is pressurized by bending the thin peripheral wall 21d on the outer peripheral side of the mounting groove 21b to form the crimping portion 21c, and the seal formed on the inner peripheral surface of the large-diameter mounting portion 12 Since the seal protrusion 12d formed on the end face of the protrusion 12c or the large diameter attachment portion 12 is appropriately compressed, the contact surface pressure of the large diameter attachment portion 12 with respect to the inner surface of the attachment groove 21b increases locally, and is excellent. Excellent sealing performance.

  Further, when the positioning projection 12b is continuous in the circumferential direction, the positioning projection 12b also has a sealing property by being brought into close contact with the end surface 21a of the opening of the housing 21 with an appropriate surface pressure.

  On the other hand, the small-diameter mounting portion 13 of the boot 1 is outside in a state in which the inner peripheral seal protrusion 13b is closely fitted in the fitting groove 3a formed on the outer peripheral surface of the drive shaft 3 protruding from the opening of the housing 21. At the same time, the fastening band 14 is wound around the band mounting groove 13a to be fastened and fixed.

  In the above-described embodiment, the boot mounting structure for sealing the constant velocity universal joint provided on the propeller shaft of the automobile has been described. However, the present invention seals other constant velocity universal joints, ball joints, and the like. The present invention can also be applied to a boot mounting structure.

DESCRIPTION OF SYMBOLS 1 Boot 11 Flexible part 12 Large diameter attaching part 12b Positioning protrusion 12c, 12d Seal protrusion 13 Small diameter attaching part 2 Constant velocity universal joint 21 Housing 21a End surface 21b Mounting groove 21c Caulking part 22 Torque transmission member 3 Drive shaft

Claims (1)

  A deformable cylindrical flexible portion, a large-diameter attachment portion formed at one end of the flexible portion and attached to the housing, and attached to a shaft formed at the other end of the flexible portion and extending from the inner periphery of the housing The large-diameter mounting portion of the boot made of a rubber elastic body having a small-diameter mounting portion is closely fitted in a mounting groove formed on the end surface of the housing, and a crimped portion formed on the peripheral wall of the mounting groove A positioning projection is formed on the inner peripheral surface of the end portion of the flexible portion on the side of the large-diameter mounting portion so as to be in close contact with the end surface of the housing. A boot mounting structure characterized in that a seal protrusion is formed in close contact with the inner surface of the mounting groove.

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