JPS583849A - Resin film coating of vulcanized rubber surface - Google Patents

Abstract

PURPOSE:To prevent generation of buckling phenomenon without detriment to flexibility of vulcanized rubber, by forming a resin film layer of low permeability on a surface of vulcanized rubber. CONSTITUTION:On the surface of a flexible boot 1 having a bellows like part 2 composed of vulcanized rubber of a uniform velocity joint, a steering mechanism etc. a solution of resin of low permeability (e.g.; polyvinylidene chloride) is applied or a thin film layer 5 is formed by immersing in a liquid. By this, air inside the flexible boot does not present a negative pressure due to air permeation to the outside in use and generation of buckling phenomenon can be prevented.

Description

[Detailed Description of the Invention] The present invention relates to a resin coating method on the surface of vulcanized rubber, and more specifically,
By forming a layer of resin with low gas permeability on its surface,
The present invention relates to a method of obtaining a vulcanized rubber surface that prevents gas permeation. The present invention is particularly suitable for resin coatings on the surfaces of bellows-shaped flexible boots used in constant velocity joints, steering mechanisms, and other various uses.

The flexible sheet is made of rubber to retain lubricating grease such as a constant velocity joint inside and to prevent foreign matter such as dust and water from entering from the outside. Figure 1 shows a constant velocity joint equipped with a flexible boot. Joint outer ring 6 and joint inner ring 7
The thick-walled annular portions of the openings at both ends of the flexible boot 1, that is, the attachment portions 3 and 4 are attached to the rotating shaft 8 which is inserted into and fixed to the rotating shaft 8, and the outer periphery thereof is fixed by tightening with a tightening member 10 such as a band. However, as mentioned above, it prevents lubricant leakage and foreign matter from entering from the outside, and maintains a sealed state. The flexible sheet 1 is made up of the above-mentioned thick layer mounting portion 3.4 and the thin layer bellows-shaped portion 2 formed in the middle thereof. Flexible boots need to have flexibility to prevent breakage by absorbing the impact of solid objects such as stones flying in from the outside and have the strength to withstand high-speed rotation. For this reason, flexible boots of this type are generally made of rubber-like elastic material, such as vulcanized rubber.

However, in the flexible boot constructed as described above, due to heat generated by the joint in a high-temperature atmosphere or at high speed rotation, air flows from the rubber part forming the bellows-shaped part 2 due to an increase in internal pressure accompanying the temperature rise in the flexible boot 1. It passes through and escapes to the outside, creating negative pressure when the temperature inside the boot drops at low temperatures or when the boot is stopped. This causes the bellows-like portion of the Flexidel sheet to buckle inward and become depressed.

If the Flexidel sheet is rotated again in this deformed state, it will be damaged.

The aim of the invention is to provide a method for eliminating the aforementioned drawbacks.

FIG. 2 shows an example in which the resin coating method of the present invention is applied to 7 Lexiple dates. A thin coating layer 5 is formed on the wide surface of the vulcanized female on the outer periphery of a conventional 7-rexisol date 1 made from a vulcanized resin using a solution of a resin having extremely low gas permeability, such as vinylidene chloride resin.

The resin coating layer 5 is formed by applying a solution or by immersing it in a liquid.

As the solution, a molten solution obtained by heating the resin or a diluted solution obtained by dissolving the resin in a solvent is suitable. This coating layer 5 can prevent gas from permeating from the surface of the vulcanized beam.

As described above, according to the present invention, a coating layer made of a resin that prevents gas permeation can be formed on the surface of a vulcanized imm by a simple method without impairing flexibility. Therefore, when this method is applied to Flexidel sheets, the air inside the Flexidel sheets will not permeate to the outside during use and create a negative pressure, preventing the buckling phenomenon and improving durability. This will lead to improvements in

Although Flexidel sheets have been described in the Examples, the present invention is not limited thereto.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a constant velocity joint fitted with a conventional Flexidel sheet, and FIG. 2 is a sectional view of a flexible sheet made according to the present invention. 1... Flexible boots, 2... Bellows-shaped portion, 5.
...Coating layer. Representatives: Asamura and 4 people

Claims (1)

[Claims] A resin coating on the surface of vulcanized rubber, characterized by forming a coating layer that prevents gas permeation by coating the surface of the vulcanized rubber with a solution of a resin with low gas permeability or by immersing it in a liquid. Law.