JPS6351112A - Method and apparatus for preheating pipe-shaped material - Google Patents

Abstract

PURPOSE:To make it possible to stretch uniformly in a stretching blow forming in an after process by a method wherein a pipe-shaped material is held by a pipe holder, which is mounted on a conveying device so as to be forcibly rotated. CONSTITUTION:A pipe-shaped material 3d of a fixed length, which is fed intermittently from a hopper 1, is positioned to a position 3d by a guide 32 and, after that, held by pushing the tip parts 36 of pipe holders 35 in a hollow hole part 33. After that, when the guide 32 is lowered by means of an air cylinder 39, conveyer 34 starts to move so as to carry the pipe-shaped material 3d in the interior of a heating device 6. When the material 3d reaches the interior position 3e, a sprocket 40 engages with a driving chain 41 so as to start the rotation of the material 3d. Next, when the pipe-shaped material 3d of a fixed length is moved to the position 3f by the repetition of the intermittent motion of the conveyer 34 and heated up to the predetermined temperature, the rotation of the material 3d is stopped. During the stop of the material 3d at the position 3g, the tip parts 36 of the pipe holders 35 are drawn out of the material 3d in order to supply the material 3d to the following process. Accordingly, since the rotation of the material is possible even when the deflection of the material develops due to its softening by heating, the uniform fabrication and the like in the following process become possible.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is generally applicable to devices for uniformly heating synthetic resin pipes cut into fixed lengths, and is applicable to unstretched synthetic resin pipes. The present invention relates to a method and apparatus for preheating a pipe-like product that can be used in a preheating device installed before the step of forming a stretched pipe-like product using a stretch-forming machine.

(Prior Art) A preheating device for a synthetic resin pipe (hereinafter referred to as a pipe) which has been generally used is shown in Figs. 4 and 5.
To explain the figures, Fig. 4 is the overall view, Fig. 5 is the 4th
Sectional views V to ■ of the figure are shown.

In the figure, 1 is a hopper that stores pipe-like objects 3.3a and 3b3c of fixed length and supplies the pipe-like objects in synchronization with the movement of the conveyor chain 2 at the bottom, and 2 is a chain with an attachment attached to a guide 4. The guide 4 supports a pipe-like object 3 of a fixed length.

A fixed guide 5 is fixed to the frame 7 and defines the vertical and lateral positions of the fixed-length pipe-like members 3.3a, 3b, and 3c. 6 is a heating device, conveyor chain 2
It covers the outside of the pipe and has a built-in heater to raise the temperature to a predetermined temperature while the fixed-length pipe-shaped object 3 moves to the position 3b.The built-in heater is a far-infrared heater in the case of the drawing. However, this may also be an electric heater or hot air device. The frame 7 also supports the hopper 1, the fixed guide 5, the heating device 6, the drive motor 14, and the conveyor 2.

Reference numeral 8 denotes a drive belt, which rotates the fixed-length pipe-like objects 3a and 3b by running and contacting them by friction.In the case of the drawing, it is a round belt, but it may be a flat belt. 9 is a sprocket that drives the conveyor chain 2; IO is a drive device that moves the conveyor chain 2 intermittently; 11 is a drive device 1
12 is a sprocket that drives the sprocket 9 via a shaft; 13 is a chain used to drive the sprocket 12; 14 is a drive device that is attached to the frame 7 and constantly rotates; 15
1 is a sprocket attached to the drive motor 14; 16 is a sprocket that drives the belt pulley 18 via a shaft; 17 is a chain that drives the sprocket 16;
8 is a belt pulley that moves the drive belt 8.

Now, in FIGS. 4 and 5, the extruded pipe-shaped material 3 is cut into a predetermined length and stored in the hopper 1. As shown in FIGS. Then, one or more pieces (three pieces in the illustrated example) are supplied from the hopper 1 at a time when the conveyor 2 is stopped.

The supplied pipe-like object 3 of fixed length is supported by a guide 4 and a fixed guide 5 attached to the conveyor and positioned at a position 3a. After the pipe-like object 3 is supported by the guide 4 and the fixed guide 5, the conveyor 2 starts moving. The conveyor 2 moves intermittently three pitches at a time, and the fixed length pipe-shaped 'JjyJ3a enters the inside of the heating device 6. When the pipe-like object 3 of fixed length comes to the position 3a inside the heating device 6, the pipe-like object 3a contacts the running drive belt 8 and starts rotating due to friction.

When the conveyor 2 repeats intermittent movement and the fixed-length pipe-like object 3a moves to the position 3b, it is heated to a predetermined temperature, the drive belt 8 comes off, and the rotation stops. This pipe-like material 3b is further moved to a position 3c and is supplied to the next process. The conveyor 2 is driven by a sprocket 9 driven by a drive device 1° via sprockets 11, 12 and a chain 13. Further, the driving belt 8 is driven by a drive device 14, sprockets 15, 16, a chain 17,
This is done via belt pulley 18.

(Problems to be Solved by the Invention) When synthetic resin is used as a pipe-like product, if it is extruded as an unstretched pipe-like product and then subjected to stretch molding and heat-setting processing to form a stretched pipe-like product, heat resistance performance, It has advantages such as improved pressure resistance. One of the methods for producing stretched pipe-like products is the so-called batch 2 method, in which an unstretched pipe-like product is produced using an extrusion molding machine, a pipe die, a sipe, and a cutting machine, and a stretched pipe-like product is formed in a separate process. is advantageous when producing large quantities of drawn pipes.

In addition, when making an unstretched pipe-like product into a stretched pipe-like product by stretch blow molding, it is necessary to raise the temperature to an appropriate and uniform temperature. When it reaches a temperature of There was a problem that a stretched pipe-like object could not be made.

(Means for Solving the Problems) Therefore, the present invention provides a method for preheating a synthetic resin pipe-like object that is moved by a conveying device in a heating device and cut into a fixed length. The pipe holder is held by a pipe holder attached to a conveying device, and the pipe holder is forcibly rotated, and this is used as a means to solve the problem.

The present invention also provides a preheating system for the pipe-like object, which comprises a conveying device for conveying a synthetic resin pipe-like object cut into a fixed length, and a heating device installed along the conveying device capable of preheating the pipe-like object. In the apparatus, the conveying device includes a rotatable pipe holder holding the pipe-shaped object,
This is a means to solve problems.

The synthetic resin that is the material of the pipe-shaped article of the present invention is a thermoplastic resin such as polyester, polyamide, or polycarbonate. Furthermore, forcibly rotating as used in the present invention means rotating a pipe holder attached to the transport device using an external drive device, etc., and by rotating the pipe-shaped object held by the holder, the pipe holder attached to the transport device is rotated. The purpose is to prevent the pipe-like material inside from sagging due to heating and to ensure uniform heating. Furthermore, the rotational speed is determined by the length of the pipe, but for a pipe of 30 to 150 cra, it is 10 to 150 H/min, preferably 30 to 90 mm/min. In addition, if the rotation speed is less than 1°/min, not only will the heating become uneven, but the center of the pipe will sag.
If the speed exceeds 0.1 m/min, the pipe-like material will sag due to centrifugal force.

(Function) Once the synthetic resin pipe-like object is stopped in the heating device, the softened pipe-like object deforms due to its own weight, so it is constantly rotated and heated.

When heating a synthetic resin pipe while rotating it using the conventional friction drive method using a belt, even a slight deflection makes it difficult to rotate, resulting in further deformation.So this is a solution. For this purpose, a pipe holder is prepared to hold the pipe-like object, a sprocket is attached to the end of the pipe, and the sprocket is driven by a chain to forcibly rotate the pipe-like object.

(Example) The present invention will be described below with reference to embodiments shown in the drawings.

Examples of the present invention are shown in FIGS. 1, 2, and 3.
In the figure, 32 is a guide that is attached to the rod of the air cylinder 39 and moves up and down while supporting a fixed length pipe-like object 3d, 33 is a hollow hole part of the fixed-length pipe-like object 3d, and 34 is an attachment chain for the guide 32. The conveyor 35 to which the conveyor 35 is attached is a pipe holder that holds a fixed length pipe-like object 3d by inserting the tip end 36 into the hollow hole 33 from both sides, and the length l of the holding part is equal to the length of the pipe-like object 3e. The length is 1 to 10%, preferably 2 to 5% of the total length, and the tip 36 is made of a material with poor heat transfer such as ceramic, for example, with a specific heat of 0.2 c.
al/g"C or more and a heat distortion temperature of 80"C or more according to ASTM D648, preferably 100"C or more is used. An air cylinder 37 is attached to the frame 47 and pushes the pipe holder 35 to push the tip 36 of the holder 35 into the hollow hole 33.

38 is a plate fixed to the tip of the rod of the air cylinder 37. Further, the air cylinder 39 is fixed to the frame 47 and raises and lowers the guide 32 attached to the tip of the rod. 40 is a sprocket that rotates together with the pipe holder 35; 41 is a sprocket 4;
A drive chain driven by 4, 42 is a drive motor 1
4 is a sprocket attached to the sprocket, 43 is a sprocket 42, a sprocket driven by a chain 46,
A sprocket 44 is driven by the sprocket 43 through a shaft, and a sprocket 45 adjusts the tension and position of the drive chain 41 driven by the sprocket 44. The chain 46 drives the sprocket 43, and the frame 47 includes the hopper 1, the heating bag W6, the drive motor 14, and the air cylinder 3.
7.39 and conveyor 34.

Next, the operation will be described. A required number of pipe-shaped objects cut into a fixed length are intermittently supplied from the hopper 1 (three at a time in the embodiment). The supplied pipe-like object 3d of fixed length is positioned at the position 3d by the guide 32 (Fig. 2).
. Then, the tip 3 of the pipe holder 35 attached to the conveyor 34 is inserted into the hollow hole 33 of this pipe-like object 3d.
6 is pushed in by the plate 38 attached to the air cylinder 370, and the pipe-like object 3d is held (FIG. 3). Note that the hollow hole 33 of the pipe-like object 3d
The fitting of the tip end 36 of the pipe holder 35 is such that it is easy to insert and remove, and the pipe-like member 3d of a fixed length can be rotated in one direction by the rotation of the pipe holder 35.

Next, after the fixed-length pipe-like object 3d is held by the pipe holder 35, the guide 32 is lowered by the air cylinder 39 to a position where it does not interfere with the movement of the fixed-length pipe-like object 3d, and the conveyor 34 Start moving. conveyor 3
4 moves intermittently by 3 pitches, and the pipe-like object 3d
enters the inside of the heating device 6.

Next, the pipe-like object 3d is placed at the position 3e inside the heating device 6 (
3), the drive chain 41 on which the sprocket 40 attached to the end of the pipe holder 35 runs
It engages and starts rotating.

Next, the conveyor 34 repeats intermittent motion, and when the fixed length pipe-like object 3d moves to the position 3f and is heated to a predetermined temperature, the sprocket 40 comes off the drive chain 41 and stops rotating.

Next, while the pipe-shaped object 3d is stopped at the position 3g, the tip 36 of the pipe holder 35 is pulled out from the hollow hole 33 and is supplied to the next process. In addition, the driving of the conhair 34 is as follows.
The sprocket 9 is moved to the sprocket 11 by the driving device 10.
．． 12, via chain 13. drive chain 4
The running drive of No. 1 includes a drive device 14 and a sprocket 42.4.
3.44.45, via chain 46. In addition,
Instead of the conveyor 34, other conveying devices (eg, swing arm type, walking beam type, etc.) may be used.

(Effects of the Invention) As explained in detail above, the present invention is structured so that
Hold a fixed length synthetic resin pipe with a pipe holder,
If you move this inside the heating device while rotating it,
Even if some deflection occurs due to its own weight due to softening due to heating, it can still be rotated and the temperature rises uniformly, so
Uniform molding becomes possible in the next process.

[Brief explanation of the drawing]

Fig. 1 is a side view of a preheating device showing an embodiment of the present invention;
The figures are sectional views from ■ to ■ of Fig. 1, Fig. 3 is a sectional view of the same as shown in Fig. 2, showing a state in which a fixed-length pipe-like object such as a synthetic resin is held by a pipe holder, and Fig. 4 is a sectional view of the conventional A side view of the pipe-shaped object preheating device, FIG. 5 is a sectional view taken along the line V-V in FIG. 4. Description of main parts of the figure 3. 3a, 3b, 3cm fixed length pipe-shaped object 6 - Heating device 14 - Drive device 34 - Conveyor 35 - Pipe holder Patent Applicant: Mitsubishi Heavy Industries, Ltd. Toyobo Co., Ltd. Co., Ltd. Procedural Amendment November 4, 1985 Commissioner of the Patent Office Black 1) Mr. Yu Akira 1, Indication of the Case Patent Application No. 1987-192773 2, Title of Invention Method and Apparatus for Preheating Pipe-shaped Products 3, Amendment Relationship with the case involving the person who filed the patent application Patent applicant address: 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Name:
(620) Mitsubishi Heavy Industries, Ltd. 1 other person 4, agent address: 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Heavy Industries, Ltd. Name (6924) Patent attorney Arata Ishikawa, 2 other people 5
, Contents of Sub-Agent Amendment ■, riA Specification, No. 8 Thin Tube, Page 8, No. 202, ``Length 1'' in the 4th line of Page 9 is corrected to ``Length 1''. that's all

Claims (2)

[Claims] (1) In a method of preheating a synthetic resin pipe-like object that is moved by a conveying device in a heating device and cut into a fixed length, the pipe-like object is held by a pipe holder attached to the conveying device, and , a method for preheating a pipe-like object, characterized by forcibly rotating the pipe holder. (2) In a preheating device for pipe-like objects, which consists of a conveyor device that conveys a synthetic resin pipe-like object cut into a fixed length, and a heating device installed along the conveyor device that can preheat the pipe-like object. . A preheating device for a pipe-like object, wherein the conveying device includes a rotatable pipe holder that holds the pipe-like object.