JPH01128812A - Heater of resin tubular material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tube heater used for molding resin tube materials, and in particular, the heater has uniform temperature distribution and improved thermal response.

[Conventional technology]

Generally, when thermoforming a resin tube material, a method is used in which the entire tube material is heated to a softening temperature, and then the tube material is fixed in a mold and blow molded. The heating method is to put a heating medium such as glycol in a tank and adjust it to the softening temperature of the tube material to be heated, and then immerse the tube material in it and heat it to soften it, or to adjust it to the softening temperature of the tube material to be heated in an electric furnace. Then, a tube material is inserted into it and heated to soften it.

(Problem to be solved by the invention) However, due to the nature of resin, the molding temperature of the tube material is narrow, and if it is heated too much, the tube material will melt, so it is necessary to accurately control the temperature between the softening temperature and the melting point. be. Particularly in the case of tube materials with a narrow interval between the softening temperature and the melting point, temperature control is difficult and yields are poor. Furthermore, when a heat medium tank is used, it is necessary to remove the heat medium after heating, which is difficult to process.

Further, heat medium tanks and electric furnaces require a considerable amount of time to reach a predetermined temperature, and require a stirring device to make the internal temperature uniform. Furthermore, the amount of heat dissipated when inserting and removing the tube material is large.

(Means for Solving the Problems) In view of this, and as a result of various studies, the present invention has developed a heater made of a resin tube material that has uniform temperature distribution and rapid thermal response. An annular groove for inserting the tube material is provided in the tube, a working fluid is sealed inside to make the container into a heat pipe, the bottom surface of the container is used as a heat receiving surface, and the annular groove part is used as a heat dissipation surface.By heating the heat receiving surface, the tube is inserted into the annular groove. It is characterized by heating the pipe material from the inside and outside.

[For production]

The heater of the present invention is made into a heat pipe as described above, and when the heat receiving surface is heated with a gas burner, electric heater, etc., the temperature of the annular groove rises and becomes a heat radiation surface, heating the tube inserted into the groove from the inside and outside. do.

The temperature rise in the annular groove is a phenomenon unique to heat pipes, and because the temperature rises quickly and the temperature distribution is uniform, the temperature is constant in any part without using a stirrer or the like. Therefore, the tube inserted into the annular groove is heated evenly from the inner and outer surfaces.
Heat pipes are characterized by the short time it takes to reach a predetermined temperature, so they can be put into operation immediately.

In addition, since the tube material insertion opening can be made approximately equal in cross-sectional area to the tube material, heat loss during insertion and removal of the tube material can be reduced.

As the working fluid sealed in the container, naphthalene, a mixed solution of diphenyl and diphenyl oxide, water, etc. are used.

(Example) Figure 1 shows an example of the heater of the present invention. As shown in the figure, a resin tube is inserted into a cylindrical metal container (1) from the top surface (2) toward the inside. An annular groove (3) is provided, naphthalene is sealed inside as a working fluid (4), the container (1) is made into a heat pipe, the bottom surface (5) of the container (1) is used as a heat receiving surface, and the annular groove ( 3) is the heat radiation surface.Thus, although not shown in the figure, the bottom surface (5) of the container (1) is heated by a heat source such as a gas burner or an electric heater to operate the heat pipe, and the working fluid ( 4) is evaporated on the heat-receiving surface of the bottom surface (5) and condensed on the heat-radiating surface of the annular groove (3), thereby raising the temperature inside the annular groove (3).

When the inside of the annular groove (3) reaches the set temperature, the resin tube (7) is inserted into the upper annular groove (3) of the container (1) and heated as shown in FIG.

In the top view, (6) shows a thermocouple that outputs a signal to the heat amount control device of the heat source in order to control the temperature of the annular groove to a set temperature.

As described above, since the heater of the present invention is made into a heat pipe, the temperature distribution inside the annular groove is uniform, the time to reach the set temperature is short, and the temperature is maintained at a constant temperature in any part. The tube inserted into the tube is heated evenly from the inside and outside. Further, since the area of the entrance and exit of the tube material in the annular groove can be easily made approximately equal to the cross-sectional area of the tube material to be heated, heat loss due to insertion and removal of the tube material is extremely small.

(Effects of the Invention) As described above, according to the heater of the present invention, the heating time of the resin tube material is short and any part is heated uniformly, so not only can operations be started immediately, but also the yield can be improved. It has remarkable industrial effects, such as a remarkable reduction in heat loss due to the insertion and removal of pipe materials.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing one embodiment of the heater of the present invention;
The figure is an explanatory view showing the process of inserting a resin tube into the heater of the present invention. 1. Metal container 2, top surface 3, annular groove 4, working fluid 5, bottom surface 6, thermocouple 7, resin tube material

Claims (1)

[Claims] By providing an annular groove for inserting the tube material in the upper part of the metal container, sealing the working fluid inside and turning the container into a heat pipe, the bottom surface of the container is used as a heat receiving surface, and the annular groove part is used as a heat radiation surface to heat the heat receiving surface. A heater for resin pipe material, which heats the pipe material inserted into the annular groove from the inside and outside.