JP2009299811A - Split type boot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a split type boot having a good product shape whose height is not increased and whose bellow part is free from deformation. <P>SOLUTION: The bellow part of this split type boot 1 is composed of a boot body 3, a small diameter mounting part 5 having an opening consolidated with one end of the boot body 3, and a large diameter mounting part 7 having an opening integrated with the other end of the boot body 3. The small diameter mounting part 3 and the large diameter mounting part 5 are each constituted of semi-circular portions 19A, 19B/21A, 21B having the same radii R1/R2, straight portions 23 where one-side ends of the semi-circular portions 19A, 19B/21A, 21B are integrated, and openings 25 in which the other ends of the semi-circular portions 19A, 19B/21A, 21B have the same length as the straight portions 23. The opening 25 is furnished with an engaging projection 27 at one side, and with an engaging recess 29 to be engaged with the projection 27 at the other end. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a split type boot that is used as a cover of a constant velocity universal joint for a drive shaft of an automobile, for example, and at least one side portion from one end to the other end of a cylindrical end opening is divided.

  Conventionally, for example, a constant-velocity universal joint for a drive shaft of an automobile has a joint boot as a cover boot made of a material such as rubber having elasticity and flexibility for the purpose of preventing dust and scattering of lubricating oil (grease). It is covered.

  In this type of boot, the mounting portion on one large diameter side of the constant velocity joint of the automobile is attached to the outer race of the constant velocity joint, and the other small diameter mounting portion is attached to the drive shaft. While the bellows-like body portion of the boot body is flexibly bent (stretched and deformed), the entry of foreign matter from the outside and the leakage of grease filled in the constant velocity joint are prevented.

  The above-mentioned boot includes a split type boot. Patent document 1 etc. are known as this split type boot. For example, as shown in FIG. 3, the conventional split type boot 101 includes a boot body 103, and the boot body 103 includes a small-diameter attachment portion 105 formed at one end in the axial direction, and an axial direction. A large-diameter attachment portion 107 formed at the other end, and a thin bellows portion 113 in which crest portions 109 and trough portions 111 extending in the circumferential direction are repeatedly formed between the attachment portions 105 and 107. Have.

  Band mounting grooves 115 and 117 extending in the circumferential direction are formed on the outer peripheral surfaces of the mounting portions 105 and 107, respectively. For example, universal joints are provided in the band mounting grooves 115 and 117 via spacers (not shown). The drive shaft and a band for binding to the outer peripheral surface of the outer race are wound around.

  Further, in order to mold the split type boot 101, a mold 201 as shown in FIG. 4 is used. The mold 201 was formed in an opening shape with an angle α, for example, 20 °. At this time, the diameter of the small-diameter is d1, the diameter of the large-diameter is d2, and the product shape of the split boot 101 obtained by using this mold 201 is closed with reference to FIG. Since the shape dimensions at the time of molding are small diameter D1 and large diameter D2 at the time of product, the circumferential length is obtained by adding the circumferential length of the opening to the circumferential lengths πD1 and πD2. Consists of a diameter with

  That is, when the diameter D1 is 30.0, the diameter D2 is 80.0, and the opening angle is 20 °, the development dimension can be obtained by calculating the circumferential length of the developed state (340 °) and the circumferential length of the product. To be equal, D ′ = (product diameter * π * 360 °) / (340 ° * π).

  When calculated by the above method, in the product state, the difference X in the height dimension between the small diameter portion and the large diameter portion of the split type boot 101 is X = (80/2) − (30/2) = 25 mm. The difference X between the heights of the mold shapes is as follows: d1 = 30 * 18/17 = 21.77, d2 = 80 * 18/17 = 84.71, X = (84.71 / 2) − (21 .77 / 2) = 26.48 mm.

As a result, a height difference of 1.48 mm occurs between the mold shape height and the product shape height.
JP 2000-18384 A

  By the way, in the conventional split-type boot 101 of Patent Document 1, as described above, when the split-type boot having an opening with an angle as formed by the mold of FIG. 4 is combined as shown in FIG. A phenomenon occurs in which the split boot 101 is deformed in an attempt to correct the difference in height and the error in the center position of the circle. This deformation results in pushing up the bellows portion 113 of the boot body 103, resulting in an increase in the height of the split boot 101 or a deformation of the shape of the bellows portion 113, which is problematic for a good product shape.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a good product shape in which the height of the boot does not extend and the shape of the bellows portion does not deform.

The split boot according to the present invention has a bellows-shaped boot body, a small-diameter mounting portion having an opening integrated on one end side of the boot body, and an opening integrated on the other end side of the boot body. A split-type boot comprising a large-diameter mounting portion,
The small-diameter attachment portion and the large-diameter attachment portion are each a semicircle portion having the same radius, one end portion side of each semicircle portion is integrated, a straight portion, and the other end portion side of each semicircle portion is the above-mentioned Formed with an opening having the same length as the straight portion,
An engaging convex portion is provided on one side of the opening, and an engaging concave portion that is engaged with the engaging convex portion is provided on the other side of the opening.

  In the split type boot according to the present invention, it is preferable that the length of the straight portion is slightly longer than the length of the engaging convex portion in the split type boot.

  In the split boot according to the present invention, in the split boot, the boot main body, the small diameter mounting portion, and the large diameter mounting portion are preferably made of resin.

  As can be understood from the means for solving the problems as described above, according to the present invention, it is possible to obtain a split boot having a good product shape in which the height of the boot does not extend and the shape of the bellows portion does not deform. it can.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2, the split boot 1 according to this embodiment has one end attached to the outer peripheral surface of an outer race of a constant velocity joint (not shown) and the other end attached to a drive shaft. The boot body 3 is made of an elastic material, and the boot body 3 has a small-diameter attachment portion 5 formed at one end in the axial direction and a large-diameter attachment formed at the other end in the axial direction. And a thin bellows portion 13 in which a crest portion 9 and a trough portion 11 extending in the circumferential direction are repeatedly formed between the attachment portions 5 and 7.

  Band mounting grooves 15 and 17 extending in the circumferential direction are formed on the outer peripheral surfaces of the mounting portions 5 and 7, respectively. For example, universal joints are provided in the band mounting grooves 15 and 17 via spacers (not shown). The drive shaft and a band for binding to the outer peripheral surface of the outer race are wound around.

  In addition, a general industrial synthetic rubber is used as the elastic material. In this embodiment, a material such as a thermoplastic elastomer / polyether urethane resin is preferably used. Other examples of the elastic material include chloroprene rubber (CR), chlorinated polyethylene (C), chlorosulfonated polyethylene (CS), and silicone rubber (VQ).

  In FIG. 2, the upper small-diameter attachment portion 5 is attached to the outer periphery of the drive shaft via a small-diameter spacer. In FIG. 2, the lower large-diameter attachment portion 7 is attached to the outer race on the large-diameter side. It is attached via the spacer. Therefore, the small-diameter attachment portion 5 has a relatively small diameter, the large-diameter attachment portion 7 has a relatively large diameter, and the plurality of peak portions 9 and the plurality of valley portions 11 in the bellows portion 13 have a large diameter. Smaller diameters are formed sequentially from the attachment portion 7 side toward the smaller diameter attachment portion 5 side.

  Band attachment grooves 15 and 17 that are continuous in the circumferential direction are formed on the outer peripheral surfaces of the small-diameter attachment portion 15 and the large-diameter attachment portion 17, and metal bands are respectively provided in the band attachment grooves 15 and 17. The small-diameter attachment portion 5 and the large-diameter attachment portion 7 are fastened and fixed.

  The small-diameter attachment portion 5 and the large-diameter attachment portion 7 are semicircular portions 19A, 19B; 21A, 21B having the same radii R1, R2, respectively, and one ends of the semicircular portions 19A, 19B; 21A, 21B. The straight part 23 having a length A in the part side (lower side in FIG. 1) and the other end part side (upper side in FIG. 1) of each semicircular part 19A, 19B; 21A, 21B An opening 25 having the same length A as the straight portion 23 is formed.

  An engagement recess 29 is provided on one side of the opening 25, for example, on one side of the semicircular portions 19A and 21A, and is engaged with the engagement protrusion 27 on the other side of the opening 25. It has.

  Thus, in order to suppress the deformation of the shape and the error in dimensions, if the length A of the straight portion 23 of the opening 25 is, for example, 7 mm, the shape at the time of molding is the straight portion 23 and the semicircular portions 19A, 19B; When configured with 21A and 21B arcs, the radius R1 of the small-diameter mounting portion 5 of the product split-type boot 1 is 19 mm (diameter φ38 mm), and the radius R2 of the large-diameter mounting portion 7 is 58 mm (diameter φ104 mm) The height difference X is X = (104−38) / 2 = 33, and the radius R′1 of the small diameter attachment portion 5 at the time of molding is R′1 = (38 * π−7) Since /(2*π)=17.9, the diameter 2R′1 is 35.8 mm. Since the radius R′2 of the large-diameter attachment portion 7 is R′2 = (104 * π−7) / (2 * π) = 50.9, the diameter 2R′2 is 101.8 mm. In this case, the height H from the tip of the small-diameter attachment portion 5 shown in FIG. 2 to the lower end of the large-diameter attachment portion 7 is 110.0 mm.

  Therefore, the mold has a radius R′1 of the small diameter mounting portion of 17.9 mm (diameter φ35.8 mm) and a radius R′2 of the large diameter mounting portion of 50.9 mm (diameter φ101.8 mm). Therefore, the height difference X is X = (101.8-35.8) / 2 = 33, and the height of the mold shape is the same as the height of the product shape. As a result, even if the engaging convex portion 27 of the split boot 1 is engaged (fitted) with the engaging concave portion 29 after molding, no stress is generated due to the height error, and the deformation amount is reduced.

  As described above, the planar shape of the small-diameter mounting portion 5 and the large-diameter mounting portion 7 of the split-type boot 1 in which the engaging convex portion 27 is engaged (fitted) with the engaging concave portion 29 after molding includes a semicircular portion. 19A and 19B, 21A and 21B have a strobe 23 on one side, but there is no problem even if circular spacers (not shown) are attached to the small diameter mounting portion 5 and the large diameter mounting portion 7, respectively. It can be used without.

  Thus, a good product shape of the split boot 1 can be obtained in which the height of the boot does not extend and the shape of the bellows portion 13 does not deform.

1 is a plan view of a split boot according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. 1. It is a longitudinal cross-sectional view of the conventional split type boot. The top view of the metal mold | die shape used when manufacturing the conventional split type | mold boot is shown. It is a top view of the conventional split type boot.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Split type boot 3 Boot main body 5 Small diameter attachment part 7 Large diameter attachment part 9 Mountain part 11 Valley part 13 Bellows part 15 Band attachment groove 17 Band attachment groove 19A, 19B Semicircle part 21A, 21B Semicircle part 23 Straight part 25 Opening 27 Engaging convex 29 Engaging concave

Claims (3)

An accordion-shaped boot body, a small-diameter attachment portion having an opening integrated on one end side of the boot body, and a large-diameter attachment portion having an opening integrated on the other end side of the boot body. Split type boots,
The small-diameter attachment portion and the large-diameter attachment portion are each a semicircle portion having the same radius, one end portion side of each semicircle portion is integrated, a straight portion, and the other end portion side of each semicircle portion is the above-mentioned Formed with an opening having the same length as the straight portion,
A split-type boot comprising an engaging convex portion on one side of the opening and an engaging concave portion engaged with the engaging convex on the other side of the opening.     2. The split boot according to claim 1, wherein the length of the straight portion is slightly longer than the length of the engaging convex portion. The split boot according to claim 1 or 2, wherein the boot main body, the small-diameter attaching portion and the large-diameter attaching portion are made of resin.

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