JPH0523855Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The ball joint boots according to this invention are
It is used by being incorporated into a bearing part of an automobile steering device or suspension device.

(Prior art) A ball joint 1 as shown in Fig. 2 is attached to the joint between the rods and arms that make up the steering device, and the rods and arms are connected together.
They freely connect each other's swings.

In addition, a boot 2 is attached to the ball joint 1 to prevent dust and water droplets from entering the sliding part 3 of the ball joint 1, thereby preventing the sliding part 3 from being worn out or rusted. is prevented.

Such boots 2 have conventionally been made of a weather-resistant rubber elastomer such as chloroprene rubber.

(Problem that the invention aims to solve) However, conventional ball joint boots were not necessarily sufficiently rigid, and could be damaged by interference and dents during transportation or by flying stones while driving, thereby compromising their ability to prevent the intrusion of dust and water droplets.

In order to prevent this kind of damage to ball joint boots, it is possible to change the material used to make these boots to one with higher rigidity, but simply changing the material will not increase the force required to deform the boots. This is undesirable because it becomes unnecessarily large and forces cannot be smoothly transmitted between the rods and arms connected to each other by ball joints.

The ball joint boot of the present invention eliminates the above-mentioned disadvantages.

(Means for Solving the Problems) The ball joint boot of the present invention has a plurality of cylindrical portions whose diameters gradually increase from the inside to the outside, with the ends alternately formed into U-shaped cross sections with different curvature directions. The thickness of the plurality of cylindrical parts can be adjusted by making them smoothly continuous with each other by using a curved part whose wall thickness changes continuously.
It is constructed by integrally forming a bellows section made of synthetic resin elastomer, with the rigidity of each cylindrical section being equalized by gradually increasing the thickness from the inside to the outside.

(Function) In the case of the ball joint boots of the present invention constructed as described above, the entire body is made of synthetic resin elastomer, so it has high rigidity and is free from interference and dents during transportation, and flying stones while driving. It is difficult to be damaged by water and can prevent dust and water droplets from entering the sliding part of the ball joint for a long period of time.

In addition, the rigidity of the plurality of cylindrical parts that make up the bellows part is made equal to each other, and when the ball joint tries to displace, each cylindrical part deforms elastically little by little to absorb this displacement. Only a small amount of force is required to deform the boot, and force is smoothly transmitted between the rods and arms connected to each other by ball joints.

Furthermore, due to the curved part where the wall thickness changes continuously,
Since the ends of each cylindrical part are smoothly connected to each other, even if the cylindrical parts are displaced during use, there is no part where excessive stress is concentrated, and the durability is sufficient.

(Example) Next, the present invention will be explained in more detail while explaining the illustrated embodiment.

FIG. 1 shows an embodiment of the invention.

The ends of the plurality of (seven in the illustrated example) cylindrical parts 4 to 10 whose diameters gradually increase from the inside to the outside have a U-shaped cross section with alternately different curvature directions,
A bellows part 17 having an axially oriented corrugated shape is made of a synthetic resin elastomer such as thermoplastic polyester by connecting the curved parts 11 to 16 whose wall thicknesses continuously change. A distal end mounting ring portion 18 is attached to the small diameter side opening end of 17.
A proximal attachment ring portion 19 is formed integrally with the bellows portion 17 at the large-diameter opening end.

The thickness of the plurality of cylindrical parts 4 to 10 constituting the bellows part 17 integrally formed of synthetic resin elastomer is such that the thickness of the cylindrical part 4 with a smaller inner diameter is smaller (thinner) and the thickness of the cylindrical part 10 with a larger outer diameter is larger. (thick) so that the rigidity of each cylindrical portion 4 to 10 is equal to each other regardless of the difference in diameter.

In the ball joint boot of the present invention constructed as described above, the proximal side mounting ring part 19 is attached to the casing 20 of the ball joint 1, and the distal side mounting ring part 1 is attached to the casing 20 of the ball joint 1.
8 are attached to the intermediate parts of the joint pins 21 (see Figure 2) to prevent dust and water droplets from entering the sliding part 3 of the ball joint 1. However, in the case of the boots of the present invention, the entire Since it is made of synthetic resin elastomer, it has high rigidity and is resistant to damage due to interference and dents during transportation, flying stones, etc. while driving, and will protect the sliding part 3 of the ball joint 1 over a long period of time. It is possible to prevent dust and water droplets from entering.

Moreover, a plurality of cylindrical parts 4 to 1 forming the bellows part 17
Although the rigidity of 0 is different from each other,
Since they are equal to each other, ball joint 1
When the joint pin 21 attempts to displace with respect to the casing 20, each of the cylindrical parts 4 to 10 elastically deforms little by little to absorb this displacement.

Therefore, there is no need to particularly greatly deform only a part of the cylindrical portion, the force required to deform the boot 2 is small, and the force between the rods and arms connected to each other at the ball joint 1 is reduced. communication is carried out smoothly.

Furthermore, curved portions 11 to 1 whose wall thickness changes continuously.
6 allows the ends of each cylindrical part 4 to 10 to be smoothly continuous, so that each cylindrical part 4 to 1
Even if the 0s are displaced, there will be no areas where excessive stress is concentrated, and durability will be sufficient.

(Effects of the invention) The ball joint boots of the present invention are configured and operate as described above, so force can be smoothly transmitted between the rods and arms connected to each other by ball joints. With the state as it is,
It is possible to improve the rigidity of the boots, and
This prevents excessive stress from concentrating on one part.
It is possible to improve the reliability and durability of the ball joint attachment part.

[Brief explanation of the drawing]

FIG. 1 is a half sectional view of a ball joint boot according to the present invention, and FIG. 2 is a sectional view of a ball joint incorporating a conventional boot. 1...Ball joint, 2...Boots, 3...
...Sliding part, 4, 5, 6, 7, 8, 9, 10... Cylindrical part, 11, 12, 13, 14, 15, 16...
Curved portion, 17... Bellows portion, 18... Distal side mounting ring portion, 19... Proximal side mounting ring portion, 20... Casing, 21... Joint pin.

Claims (1)

[Scope of utility model registration request] The ends of the plurality of cylindrical parts whose diameters gradually increase from the inside to the outside are smoothly connected to each other by curved parts whose cross-sections are U-shaped and whose wall thicknesses continuously change in alternating directions of curvature. A ball joint boot with a bellows part made of synthetic resin elastomer that has a plurality of cylindrical parts that have equal rigidity by gradually increasing the thickness from the inside to the outside.