JP2001171007A5 - - Google Patents

Description

[0001]
[Industrial application field]
Resin-made small pipes are used for water supply, hot water supply, heating, road heating, etc. Connection of resin pipes is an essential task. The present invention relates to the connection of small diameter tubes (polyethylene, polybutene, polypropylene, various polypropylene copolymers, etc.) made of thermoplastic resin in such a case.

[0004]
In the HF method, although heating by means of a heater and fusion by insertion are naturally manual operations, they need to be performed in a timely manner. As we use both hands, we fix heater and do it alone, or it is work with person with heater with two people. Two joints are required for one socket, which is also cumbersome. In the case of this HF, the tolerance of the tube is corrected by the diameter of the male and female heaters, but the correction may cause the small-diameter tube to melt too much and cause the tube to be clogged. Therefore, 10A or less is not put to practical use. Since the EF and HF sockets are made by injection molding, the overall thickness is thick, and the joint becomes extremely thick.

[0011]
When the socket with such a protective film is heated, an electric heater capable of temperature control is required, and the entire outer periphery of the socket must be uniformly heated. For this purpose, semicircular heaters (A) or (B) according to the diameter of the socket are respectively prepared. Although this is still a fusion bonding method which is far more advanced than before, the present invention provides an even better method. It uses a socket covered with a collapsible metal tube having a slit along the length of the outer periphery of the socket. Thus, first, temperature control is unnecessary, and a heat source which does not depend on the outer diameter of the socket can be used. As an example, as shown in FIG. 3 (B), a metal pipe (copper, aluminum) having a thickness of about 0.5 to 1 mm is cut and slits 11 having a distance of about 2 mm are inserted in the longitudinal direction. Is put on the resin tube socket (A) or (B) of FIG.

[0013]
The state of the socket after completion of welding is as shown in FIG. 6, and the softened resin 16 slightly protrudes from the metal clad tube. The metallized tube after bonding is used but need not be removed. Such gas burners reach a maximum temperature of 1300 ° C., much higher than the fusion temperature, and seemingly unusable for fusion bonding. However, the thermal conductivity of the metal is good, the thickness and size of the cladding tube are appropriate, and even if only a part of the socket is intensively heated, the temperature becomes relatively uniform. Polypropylene copolymer, polybutene and heat-resistant polyethylene are applied in a fairly wide range of heater temperatures of about 210 ° C to 240 ° C. Therefore, even if the gas temperature of the burner is high, if the metal is heated, the metal itself dissipates heat quickly in the aforementioned temperature range.