JPH04106523U - boots - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent cracks from forming in the walls and valleys that make up the bellows part in boots that cover the transmission systems and other shaft parts of various industrial machines and vehicles. [Structure] A flat circumferential surface 12 is formed in the valley part 11 of the bellows part 2 of the boot 1 made of elastomer of thermoplastic synthetic resin, and both walls 1 extend from the flat circumferential face 12 to the peak part 10 of the bellows part 2.
3 and 13 are formed into a planar shape.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to boots that cover transmission systems and other shaft parts of various industrial machines and vehicles. It is something that

0002

[Conventional technology]

Traditionally, joints in transmission systems have been used in various industrial machines and vehicles, for example. The boots, which are made of synthetic resin elastomer that covers the parts, were developed in 1983-258. The one described in Publication No. 24 is known.

0003 This type of boot has a structure in which a bellows part a has a cylindrical fixing part to the shaft part at both ends. The shape of the valley b of the bellows part is such that the walls c and c are V-shaped, as shown in Fig. 9. Therefore, when the bellows part a contracts significantly, a small gap d is formed in the valley part b. As shown in FIG. Cracks tend to form on the sides.

0004

[Problem that the idea aims to solve]

Therefore, in the conventional device described in the above publication, as shown in FIG. uni, a groove f is provided in the valley b, and walls c and c rise from the groove f to the peak. The cross-sectional shape of the valley part forms vertical planes g and g to prevent cracks from forming in the valley part b. are doing. However, even with this configuration, when the bellows part a is contracted, As shown in FIGS. 12 and 13, a wall c slightly rises from the groove f of the trough b, The h part of c is always in contact, and cracks occur in this h part due to contact friction. Even if it is easy to prevent cracks in the valley b, it does nothing to improve the durability of the boots. It doesn't connect.

[0005] The purpose of this invention is to improve the durability of boots in view of the above problems. The flat peripheral surface formed in the valley of the bellows part and the By forming both walls that rise up to the peak into a flat shape, the bellows part was contracted. No cracks will occur in the valleys, and no cracks will occur in the walls leading from the valleys to the peaks. The company provides boots that look great.

[0006]

[Means to solve the problem]

The present invention is constructed as follows as a technical means to achieve the above object. In other words, it is made of an elastomer made of thermoplastic synthetic resin, and there are shaft parts at both ends of the bellows part. In boots with a cylindrical fixing part, peaks and valleys are formed alternately. Both walls have a flat circumferential surface in the valley of the bellows part, and rise from the flat circumferential surface to reach the peak. This is a boot formed by forming a flat shape.

[0007]

[Effect]

According to the boots according to the present invention, the valley portion of the bellows portion has a flat peripheral surface shape, and Both walls that rise from that part and reach the mountain part are flat, so the bellows part Even if the wall shrinks, both walls from the flat peripheral surface to the peak are flat, so the flat peripheral surface Large voids are formed on both sides of the valley, preventing stress from concentrating in the valley. Both walls from the top to the peak remain in a non-contact state, and even if they do come into contact, they are in surface contact. For this reason, cracks do not occur not only in the valley but also in both walls from the valley to the peak.

[0008]

【Example】

1 to 4 show a first embodiment of the present invention. FIG. 1 shows an example of a boot that seals a constant velocity joint. It is made by blow molding a plastic synthetic resin elastomer, and has a cylindrical shape at one end of the bellows part 2. The fixing part 3 is integrally formed with a cylindrical large-diameter fixing part 4 at the other end. . 5 is a constant velocity joint, 6 is its shaft part, and the fixed part 3 of the boot 1 is fitted into the shaft part 6. In addition, its outer peripheral surface is tightened by an annular fastener 7. Also, the large-diameter fixed portion 4 of the boot 1 is fitted onto the outer ring 8 of the constant velocity joint 5 and tightened. It is tightened by tool 9.

[0009] The bellows part 2 of the boot 1 is formed with alternating peaks 10 and valleys 11, The bellows portion 2 has a shape in which the ridge diameter gradually decreases from the large diameter side to the small diameter side, and the ridge portion 10 is Six valleys and five valleys 11 are formed.

0010 A flat circumferential surface 12 is formed in the valley portion 11 of the bellows portion 2, as shown in detail in FIG. ing. This flat circumferential surface 12 is formed thicker than the other walls forming the bellows portion 2. The flat circumferential surface 12 has a flat cross-sectional shape. Both walls 13, 13 from the flat circumferential surface 12 of the valley portion 11 to the peak portion 10 are connected to the flat circumferential surface 12. It is immediately formed into a planar shape, and its cross-sectional shape is straight.

[0011] The thermoplastic synthetic resin constituting the boots 1 is polyester-based, polyurethane-based, Polyamide-based, polyolefin-based and vinyl chloride-based thermoplastic elastomers A single layer or a blend of these can be formed into a single layer or a multilayer structure.

0012 According to the boot 1 of the first embodiment, when the bellows portion 2 begins to contract, As shown in FIG. 3, the shape of the vicinity of the trough 11 is such that the trough 11 has a thick flat peripheral surface 12. Therefore, both walls 13, 13 from the flat circumferential surface 12 of the valley part 11 to the peak part 10 are spaced apart. It exhibits a non-contact state with a distance of 14. When the bellows portion 2 is greatly contracted, the valley portion 11 becomes a thick flat circumferential surface 12. Therefore, as shown in FIG. 3 exhibits a greatly curved state from the flat circumferential surface 12, and both walls 13, 13 are flat circumferential surfaces. A large gap 15 is formed around 12, resulting in surface contact.

[0013] Therefore, even if the bellows part 2 of the boot 1 contracts significantly, stress is concentrated in the valley part 11. No cracks will occur in that area. Furthermore, both walls 13, 13 rising from the flat circumferential surface 12 of the valley 11 are in line with each other. There is no contact between the two walls 13, 13, and no cracks occur due to linear friction.

[0014] A second embodiment is shown in FIGS. 5-7. This second embodiment is different from the flat peripheral surface 12 of the valley portion 11 in the first embodiment. A groove 16 is formed in the middle of the width. In this way, by forming the grooves 16 on the flat circumferential surface 12 of the valley portion 11, the bellows In the state where the portion 2 is greatly contracted, the gap 15 can be further enlarged, and the first material is The effects obtained by the examples can be further improved.

[0015] FIG. 8 shows a third embodiment which is a modification of the second embodiment shown in FIG. The groove 16 of the flat circumferential surface 12 is formed to be offset to one side in the width direction. In this third embodiment as well, the same effects as in the second embodiment can be obtained.

[0016]

[Effect of the idea]

The present invention has the following effects.

[0017] That is, according to the present invention, a flat part is formed in the valley part of the bellows part in which the peak part and the valley part are formed alternately. It has a flat circumferential surface, and both walls that rise from the flat circumferential surface and reach the peak are formed in a planar shape. Because of this, even when the bellows portion is contracted, no cracks will occur in the valley. It is possible to obtain boots that do not cause cracks in the wall extending from the top to the top.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway overall perspective view showing a first embodiment.

FIG. 2 is a partially enlarged longitudinal sectional front view in FIG. 1;

FIG. 3 is an explanatory diagram of the operation of the portion shown in FIG. 2;

FIG. 4 is an explanatory diagram of the operation of the portion shown in FIG. 2;

FIG. 5 is a partially vertical front view showing a second embodiment.

FIG. 6 is an explanatory diagram of the operation of the portion shown in FIG. 5;

FIG. 7 is an explanatory diagram of the operation of the portion shown in FIG. 5;

FIG. 8 is a partially vertical front view showing a third embodiment.

FIG. 9 is a partially vertical front view of a conventional example.

FIG. 10 is an explanatory diagram of the operation of the portion shown in FIG. 9;

FIG. 11 is a partially vertical front view showing another conventional example.

FIG. 12 is an explanatory diagram of the operation of the portion shown in FIG. 11;

FIG. 13 is an explanatory diagram of the operation of the portion shown in FIG. 11;

[Explanation of symbols]

1 boots 2 Bellows part 3 Fixed part 5 Constant velocity joint 10 Yamabe 11 Tanibe 12 Flat peripheral surface 13, 13 Both walls 14 Interval 15 void 16 Groove

Claims (1)

[Scope of utility model registration request] Claim 1: A boot made of an elastomer made of thermoplastic synthetic resin and having a cylindrical fixing portion to a shaft portion at both ends of the bellows portion, in which a trough portion of the bellows portion is formed with alternating peaks and valleys. 1. A boot characterized by having a flat circumferential surface and having both walls that rise from the flat circumferential surface and reach the peaks formed in a planar shape.