JPS6184223A - Bending process of thermoplastic resin tube - Google Patents

Abstract

PURPOSE:To contrive to prevent a tube from bending upon being pushed into a groove and to reduce the thermal energy at heating and the cost of heating by bending the tube under cooling and solidifying said tube by feeding a coolant through the tube heated and softened. CONSTITUTION:A bending roll die 3 and a press die 4 are set at a specified temperature under keeping a heater 6 in ON-state. The thermoplastic tube 2 is pressed into the groove 3a of a bending roll die 3 with the press die 4, and both dies 3, 4 are closed by a cramp 5, whereby said tube is set in the grooves 3a, 4a. The tube 2 is heated and softened by being kept as it is for a specified time, and then the cool ant such as cooling water, etc. is continuously fed through the tube 2 for a specified time under the closed state of the die, thereby cooling and solidifying the tube. Next, stopping the feed of the coolant and opening the die 4, the tube having been bent is taken out. Consequently, the loss of thermal energy and the cost of heating are reduced, and the thermal deterioration of the tube except its bent portion is eliminated. When the tube is pressed into the groove, the tube has no tendency to cause creases even without preheating.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention 1;
This invention relates to a method for bending a thermoplastic resin tube, in which a 11-cove is heated and softened in a state of cera I~ with a presser mold, and then subjected to bending 1~ while avoiding cold solidification. [Prior Art] A conventional method of applying 71 force to bend this type of tube, τ, is shown in, for example, Japanese Patent Application Laid-Open No. 59-59'=117. Type 1 receiver

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Bent pipe-shaped shape imparting cavity 1 formed in J-shape 1a
A thermoplastic resin tube 12 is set in b, and the presser mold 1d connected to the mold 1a with a hinge 1C is closed, and after being heated and softened in this state, a refrigerant is passed through the tube to solidify it in a cold stage. This is a method of performing bending. [Problems to be Solved by the Invention] However, this method uses a large integrated mold having grooves for the vibrator-like shaping cavity 1b, so that the bending part of the tube is Other than that, it is necessary to heat it, and with each, there is a loss of heat energy during heating.
and heating - It takes a lot of heat per stroke, and there is a risk of bending if the tube is not heated half the width when pushing it into the vortex, and it is not possible to respond quickly even if the bending shape changes to IJ. There you go. The present invention solves these problems and uses thermoplastic P.
1 Bending of resin chicove 11j11: For the purpose of serving kl. [Means for Solving the Problems] In order to solve the problems described in bending method 1J1 of the thermoplastic resin tube according to the present invention, bending 1] Place the goo 1-bu in a press mold 1 [pip 1~
In this state, heat the mold to soften the -f''-b, and
This is characterized in that the bending process 1 is performed during cooling and solidification by passing a coolant through the bu 1-bu. [Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2. The device used in the present invention includes a bending roll mold 3 having a groove 3a on the outer circumference with a circular cross section and into which the entire cross section of the thermoplastic resin tube 2 is inserted, and a front section with a groove 3a having a circular cross section that fits the entire cross section of the thermoplastic resin tube 2. It consists of a presser die 4 with similar arc-shaped grooves 4a,
The presser die 4 can be opened and closed by a clamp 5 attached to the rear thereof. Cartridge heaters 6.6 are embedded in the bending roll die 3 and the press die 4, and are located on both sides of the shaping grooves 3a, 4a, and are provided with a temperature control mechanism for raising the die. In addition, 7 is a heat insulating material. Next, using the 1-kick device, the method of the present invention will be specifically explained. First, the ridge heater 6° 6 of the car 1 is turned on, and the 1-curve 1-roll type 3 and the press die 4 are set to a predetermined flatness of 1, and in this state, heat the plastic resin chip 12 into the press die 41 into the bending roll die 3.
: Press, close both molds 3 and 4 of clamp 5C, complete 3a,
Hit within 4a. Then, the tube 2 is left as it is for a predetermined period of time to soften it by heating, and then a refrigerant such as cooling water is passed through the tube 2 in a closed state for a predetermined period of time.Then, the tube 2 is cooled and solidified. Next, stop the refrigerant, press the presser die 1 with the crank 15, and take out the bent tube 2. [Effects of the Invention] -4- The method for bending a thermoplastic resin tube of the present invention is as described above, and therefore has the following effects. (a) Bend only the bent part of the tube from the outside L]-
Since heating is performed while the tube is set in the groove of the mold with a presser mold, there is less loss of thermal energy and heating cost compared to conventional mold heating of the entire tube, and thermal deterioration of the tube other than the bent portion is avoided. rare. (b) Since the tube is set in the groove of the bending roll type using a press die, there is little risk of bending the tube when pushing it into the groove even without preheating. (C) Even if the bending shape of the device changes in the cylinder, it can be quickly handled by changing only the bending roll type or presser type. Also, sequentially send out the chi 1-1 and bend it at 4T.
By repeatedly cutting the I culm to a certain length, it is possible to continuously form bent 1' products with a 1i1- shape. 4. Simplification of the drawings 13Il, - (Explanation Figures 1 and 2 show an embodiment of the present invention, and Figure 1 is a perspective view illustrating a method for bending a 11-ton plastic bamboo cove. Fig. 2 is a sectional view of the mold showing the position of the car ridge heater when the mold is closed, and Fig. 3 is a perspective view illustrating the conventional bending method for thermoplastic resin Chicove. Plastic resin block]-bu 3...Bending roll type 4...Press die 3a, /Ia...Full 5
... Clamp 6 ... Curl/Ridge heater 1,

Claims (1)

[Claims] 1. A thermoplastic resin tube is set in the groove of a bending roll mold with a press mold, and the mold is heated to soften the tube, and then cooled and solidified by passing a refrigerant through the tube, and then bent. 1. A method for bending a thermoplastic resin tube.