JPH0417140B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing bell peppers.

(Prior art) Conventionally, ordinary bellows used for links of mechanical devices, etc., have rubber parts.
Since they are made of cloth or synthetic resin, they are not heat resistant and can catch fire if approached by a heat source or come into contact with welding sparks.

(Problems to be solved by the invention) However, the purpose of this invention is to solve the above-mentioned conventional problems, for example.
It is an object of the present invention to provide a method for manufacturing a bellows that is safe even at high temperatures of 400°C and that is made of a non-combustible material by processing a woven fabric into a cylindrical shape.

Another object of the present invention is that the cylindrical body can be easily processed to form a bellows, and that it has a metal ring inside and can be deformed by external force on the outer periphery.
An object of the present invention is to provide a method for manufacturing a bellows that can prevent damage.

(Means for Solving the Problems) Therefore, in order to solve the above-mentioned problems, the means of the first invention impregnates a woven fabric of aromatic polyamide fibers with a fluororesin, 250℃
After drying, a cylinder is sewn into a cylinder using heat-resistant thread, and a plurality of metal rings with approximately the same diameter as the cylinder are arranged at predetermined intervals inside the cylinder. is heated at about 300 to 350°C to polymerize the fluororesin and leave each ring inside the cylinder.

In the second aspect of the invention, a woven fabric of aromatic polyamide fiber is sewn into a cylinder shape using heat-resistant thread, and the cylinder is impregnated with a fluororesin. A cylindrical body is dried at ℃, a plurality of metal rings with approximately the same diameter as the cylindrical body are arranged at predetermined intervals, and the cylindrical body with the rings arranged is heated at about 300 to 350 ℃ to form a shell. The resin is polymerized and each ring is left inside the cylinder.

The aromatic polyamide fiber woven fabric used is, for example, a heat-resistant fiber called Cornex (manufactured by Teijin KK, trade name). The fluororesin is a polymer containing fluorine such as tetrafluoroethylene resin, tetrafluoroethylene/hexafluoropropylene copolymer resin, trifluorochloroethylene resin, vinylidene fluoride resin, vinyl fluoride resin, Those with high thermal stability and high chemical resistance are used. The woven fabric is soaked in an aqueous suspension of fluoropolymer or
Impregnated by coating or spraying. The woven fabric impregnated with fluororesin is dried at 200 to 250°C without polymerizing and curing the fluororesin. The dried product is cut into a predetermined size as necessary and sewn into a cylinder. As for the metal rings, a plurality of rings having the same diameter as the cylindrical body may be arranged at predetermined intervals, or a spiral ring may be arranged. Note that a support may be used when placing the ring on the cylindrical body, and the support may be removed after processing.
The cylindrical body with the ring placed thereon is heated to cause a polymerization reaction to occur in the fluororesin impregnated into the woven fabric.

(Function) The fluororesin impregnated into the woven fabric is polymerized and hardened by heating at 300 to 350°C. i.e. 300℃
If it exceeds 350, the dimensions will gradually change and shrink.
At ℃, it shrinks by about 10% and the fluororesin polymerizes and hardens. For this reason, the ring portion of the cylinder is supported by the ring and has a predetermined diameter, and the portion between the rings becomes a small diameter portion due to contraction, forming a bellows.

(Example) Next, an example of the present invention will be described with reference to the drawings.

The woven fabric 1 shown in Fig. 1 is commercially available “Konex”.
(manufactured by Teijin KK, trade name of aromatic polyamide fiber woven fabric) is used. The woven fabric 1 is impregnated with the tetrafluoroethylene resin 2 by soaking it in an aqueous suspension of the tetrafluoroethylene resin. The woven fabric 1 impregnated with the tetrafluoroethylene resin 2 is taken out from the suspension, transferred to a drying oven, and dried at a temperature of 200 to 250°C to obtain a dried product 1A.

The dried product 1A of the woven fabric 1 is cut into a predetermined size if necessary and sewn to form the cylinder 3. For the sewing process, a heat-resistant thread 5 such as processed thread made of glass fiber impregnated with a fluororesin such as tetrafluoroethylene resin or thread of aromatic polyamide fiber is used.
Therefore, the cylindrical body 3 having the seamed portion 4 on the outside,
After folding back so that the sewn portion 4 is on the inside (see FIG. 4), the rings 6 to 6 are placed inside the cylinder 3. The rings 6 to 6 are made of metal wire such as stainless steel and have approximately the same diameter as the inner diameter of the cylinder 3. A plurality of rings 6 to 6 are arranged at predetermined intervals and supported by a support (not shown).

After that, the cylindrical body 3 in which each ring 6 to 6 is arranged
is transferred to a heating furnace and the temperature is gradually increased. Shrinkage changes were observed in the dimensions at a furnace temperature of 300°C. and 310℃
A contraction of approximately 2% was observed. At this point, the supports for each ring 6 to 6 were removed, and the remaining rings 6 to 6 were confirmed to be in place, and when further heated, they contracted by about 3% at 320°C.
At 330℃, it shrinks by about 5%, and at 350℃, it shrinks by about 5%.
A shrinkage of 10% occurred. The cylindrical body 3 had large diameter portions 1B to 1B in close contact with the rings 6 to 6 due to contraction, and a small diameter portion having a smaller diameter than the rings 6 to 6 in the inter-ring portion, thereby forming a bellows 7. Since the tetrafluoroethylene resin 2 is polymerized by heating at 350°C, there is no need to raise the temperature any further. Since the woven fabric 1 is impregnated with polymerized tetrafluoroethylene resin, it has heat resistance and functions as a bellows that can be expanded and contracted.

It should be noted that the bellows obtained in the above embodiments can be suitably used for the arm part of a working robot or the ring part of a mechanical device.

In the above embodiment, the woven fabric 1 was processed with fluororesin 2 and then sewn to form the cylinder 1, but the cylinder was formed into a cylindrical shape by sewing the woven fabric with heat-resistant thread. Afterwards, it is impregnated with a fluororesin and dried at about 200 to 250°C to form a dry cylinder, and a ring is placed on this, and thereafter a bellows having a ring inside can be formed by the same process as in the above embodiment.

Further, in the above embodiment, a circular ring 6 is provided inside the cylinder body 3.
6 are arranged to form a bellows 7 with a circular cross section, but the ring placed inside the cylinder is not limited to a circular ring, but may also be triangular, square or polygonal. It is possible to form

(Effects of the Invention) According to both inventions, since the woven fabric of the cylinder shrinks upon heating, the ring portion of the woven cylinder fabric is in close contact with the ring, and the portion between the rings of the woven cylinder fabric has a small diameter. The fluororesin impregnated into the woven fabric polymerizes and hardens, so the woven fabric becomes a fluororesin-processed product, which has excellent heat resistance and chemical resistance due to the physical properties of the fluororesin. Nonflammable.
Since this fluororesin processed body has appropriate rigidity, it has an elastic force that can be restored against compression in the direction of expansion and contraction of the bellows, and the external force applied to the outer periphery of the bellows can be absorbed by the internal ring. This is convenient for preventing deformation and damage of the bellows. Therefore, according to both of the present inventions, a good bellows made of a material in which aromatic polyamide fibers are processed with fluororesin can be obtained.

Further, in both of the present inventions, since a cylindrical body made by sewing a woven fabric into a cylindrical shape with heat-resistant thread is used, the cylindrical body for the bellows can be easily processed.

[Brief explanation of drawings]

The figures show the manufacturing process of an embodiment of the present invention. Figure 1 is a perspective view of a woven fabric made of aromatic polyamide fibers, and Figure 2 is a woven fabric impregnated with fluororesin and dried. Fig. 3 is a perspective view of the sewn cylinder, Fig. 4 is a perspective view of the cylinder with the seam inside, Fig. 5 is a front view of the ring, and Fig. 6 is the ring. FIG. 7 is a partially cutaway perspective view of the cylindrical body in which the bellows is disposed, and FIG. 7 is a front view of the bellows. DESCRIPTION OF SYMBOLS 1... Woven fabric, 1A... Dry product, 1B... Large diameter part, 1C... Small diameter part, 2... Tetrafluoroethylene resin, 3... Cylindrical body, 4... Sewn part, 6... Ring, 7...Jiyabara.

Claims (1)

[Claims] 1. A woven fabric of aromatic polyamide fibers is impregnated with a fluororesin, dried at about 200 to 250°C, and then sewn into a cylindrical shape with heat-resistant thread to form a cylindrical body, Inside the cylinder, a plurality of metal rings with approximately the same diameter as the cylinder are arranged at predetermined intervals, and the cylinder with the rings arranged is heated at approximately 300 to 350°C to cause a polymerization reaction of the fluororesin, and to A method of manufacturing jiabara characterized by leaving each ring in the 2 A woven fabric of aromatic polyamide fiber is sewn into a cylindrical shape using heat-resistant thread to form a cylindrical body, the cylindrical body is impregnated with fluororesin, and this is dried at about 200 to 250°C to form a cylindrical body. , a plurality of metal rings having approximately the same diameter as the cylinder are arranged at predetermined intervals in the cylinder,
A method for manufacturing bellows characterized by heating a cylindrical body arranged with rings at approximately 300 to 350°C to cause a polymerization reaction of fluororesin and leaving each ring inside the cylindrical body.