JPH0516205A - Regulation mechanism of wall thickness in extruder for synthetic resin pipe - Google Patents

Abstract

PURPOSE:To obtain a regulation mechanism of wall thickness in an extruder for a synthetic resin pipe wherein connection and regulation of both an eccentric for regulating wall thickness and a driving motive power part are made easy when a mold or a mandrel is replaced. CONSTITUTION:The regulation mechanism of wall thickness in an extruder for a synthetic resin pipe measures the distribution of wall thickness of the extruded synthetic resin pipe and automatically moves the tip part of a mold 1 in the radial direction for a mandrel 2 on the basis of calculation and regulates deviation of the circumferential direction in width of radial direction of the flow path 5 of molten resin in a mold part and corrects uniformity in the circumferential direction of wall thickness of the synthetic resin pipe. The connection rods 13, 14 connect the driving motive power parts 9, 10 fitted to the main body part 8 of the extruder with the driving end parts 6, 7 of eccentrics 3, 4 for regulating wall thickness in the regulation mechanism. These connection rods 13, 14 are provided with the length regulating means 15 constituted of combination of the right and left male screw parts and true same female screw parts by which the length of the connection rods is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wall thickness adjusting mechanism for a synthetic resin pipe extrusion molding apparatus.

[0002]

2. Description of the Related Art A synthetic resin pipe extrusion molding apparatus, as shown in FIG. 4, is a solid thermoplastic synthetic resin molding material placed in a cylinder (barrel) 22 heated by a heater from a hopper 21. It is an apparatus by the extrusion molding method in which the resin is kneaded, heated, and plasticized by the rotation of the screw in the cylinder (barrel) 22 and extruded from the die (die) 23 at the tip of the barrel, and the center of the opening of the die 23. A core is fixed to the shaft, a cylindrical molten resin flow path is formed between the mold and the core, and the pipe can be continuously extruded.

Since the wall thickness of the pipe mainly depends on the cross-sectional shape of the resin flow path at the tip of the die, the cross-section gap is made variable, and the measured value of the wall thickness of the product by the sensor 24 is automatically adjusted. It is preferable to attach a thickness adjusting mechanism that feeds back to the control device 25 to adjust the thickness to the synthetic resin pipe extrusion molding device.

As a conventional technique applicable to this kind of wall thickness adjusting mechanism, there is, for example, "a pipe bending portion forming mechanism in a bent pipe manufacturing apparatus" disclosed in Japanese Utility Model Publication No. 2-44983.

FIG. 5 is a cross-sectional view of a die part for explaining the main part of the same technique, and the prior art will be described with reference to the same figure. A metal core (core) 2 is provided in the tip of a metal mold (die) 1, and the metal mold 1 or the metal core 2 can be moved vertically and horizontally by a driving mechanism. This is a mechanism for manufacturing a bent pipe by changing the width of the inner flow path 5 in the circumferential direction, that is, by changing the supply amount of the raw material resin in the circumferential direction.

If a straight pipe is drawn out by applying this mechanism, the thickness of the portion where the amount of raw material resin is supplied becomes thicker and the portion where the amount of raw material resin is supplied becomes thinner, so the circumferential deviation of the product thickness is measured.
By moving the mold 1 or the cored bar 2 vertically and horizontally, the wall thickness of the tube can be adjusted uniformly in the circumferential direction.

FIG. 6 is a schematic front view showing another prior art mold part. The core metal 2 is fixed to the main body of the molding apparatus and is located inside the mold 1. Reference numeral 3 denotes a first eccentric ring, which has an annular shape with its outer periphery and inner periphery being eccentric, and is slidably held in the circular recess of the molding apparatus body. Reference numeral 4 denotes a second eccentric ring, which has an annular shape in which the outer circumference and the inner circumference are eccentric.
It is slidably held in the eccentric wheel 3. And the second
The mold 1 is held by the eccentric wheel 4.

That is, the first eccentric wheel 3 and the second eccentric wheel 4
Is a wall thickness adjusting eccentric ring capable of adjusting the deviation in the circumferential direction of the gap 5 between the core metal and the mold by rotating the mold 1 in the vertical and horizontal directions with respect to the core metal 2. Is forming.

The first eccentric wheel 3 and the second eccentric wheel 4 are respectively provided with driving end portions 6 and 7 for rotating from the outside, and a driving power portion 9 attached to a pedestal portion of a molding apparatus main body 8. 10 and connecting rods 11 and 12 are connected.

[0010]

However, in the above-mentioned conventional example, when the mold 1 or the cored bar 2 is replaced due to the change of the specification of the product, etc., the initial setting of the mounting position of the mold 1 is not the stipulated thickness. Since the adjusting mechanism does not operate according to the specified performance, it takes time to adjust the mounting position. Further, depending on the specifications of the mold 1, the connecting rods 11 and 12 for connecting the wall thickness adjusting eccentric wheels 3 and 4 and the driving power units 9 and 10 have an inappropriate length, which makes mounting difficult, resulting in wall thickness adjusting. Excessive force is applied to the eccentric ring or mold. Therefore, there is a problem that a liner needs to be inserted between the driving power units 9 and 10 and the pedestal portion 8 for adjustment.

The present invention has been made in order to solve the above-mentioned problems of the prior art. When the mold or the cored bar is replaced, the connection adjustment between the eccentric wheel for adjusting the wall thickness and the drive power section is easy. Another object of the present invention is to provide a wall thickness adjusting mechanism for a synthetic resin pipe extrusion molding apparatus.

[0012]

For this reason, the wall thickness adjusting mechanism of the synthetic resin pipe extrusion molding apparatus according to the present invention measures the wall thickness distribution of the synthetic resin pipe extruded and automatically calculates the thickness based on the calculation. The tip end of the mold is moved in the radial direction with respect to the core metal to adjust the circumferential deviation of the radial width of the mold resin flow path of the molten resin to correct the circumferential nonuniformity of the synthetic resin pipe wall thickness. An adjusting mechanism of a synthetic resin pipe extrusion molding apparatus, wherein the connecting rod is a connecting rod that connects the drive end of the eccentric wheel for adjusting the wall thickness of the adjusting mechanism and the drive power unit attached to the main body of the extrusion forming apparatus. The present invention is intended to achieve the above-mentioned object by a configuration characterized in that it has a length adjusting means constituted by a combination of the left and right male threaded portions and the female threaded portion for changing the length of the.

[0013]

With the above construction, the length of the connecting rod is changed to the connecting rod connecting the drive end of the eccentric wheel for adjusting the wall thickness of the adjusting mechanism and the drive power unit attached to the main body of the extrusion molding apparatus. Since it has a length adjusting means composed of a combination of left and right male screw parts and female screw parts, when the mold or core metal is replaced, the core metal, the mold, the eccentric wheel for adjusting the wall thickness, the drive power part Are set to the respective prescribed positions, and the length can be easily adjusted by the length adjusting means so that the connecting rod can be connected to the drive end of the eccentric wheel for adjusting the wall thickness and the drive power unit. ..

By connecting the above methods, it is possible to perform the initial setting as specified, so that the wall thickness distribution of the extruded synthetic resin pipe is measured, and the tip of the mold is automatically radiused with respect to the core metal based on the calculation. It is possible to correct the unevenness of the synthetic resin pipe wall thickness in the circumferential direction by adjusting the deviation of the molten resin in the radial direction of the mold portion passage in the circumferential direction.

[0015]

EXAMPLES A wall thickness adjusting mechanism of a synthetic resin pipe extrusion molding apparatus according to the present invention will be described below with reference to Examples. Figure 1
FIG. 2 is a schematic front view of a mold part showing a configuration of an embodiment of the present invention, and FIG. 2 is a sectional view of the same. The same or corresponding parts as those of the above-mentioned prior art are denoted by the same reference numerals.

In both figures, the core metal 2 is fixed to the main body 8 of the molding apparatus and is located inside the mold 1. Reference numeral 3 denotes a first eccentric ring, which has an annular shape in which the outer circumference and the inner circumference are eccentric, and is slidably held in the circular recess of the molding apparatus body 8. Reference numeral 4 denotes a second eccentric wheel, which has an annular shape in which the outer circumference and the inner circumference are eccentric, and is slidably held in the first eccentric wheel 3. The mold 1 is held by the second eccentric wheel 4.

That is, the first eccentric wheel 3 and the second eccentric wheel 4
Is a wall thickness adjustment capable of changing the circumferential deviation of the gap width 5 between the core metal and the mold by rotating the tip end of the mold 1 vertically and horizontally with respect to the core metal 2 by rotating. Forming an eccentric wheel.

The first eccentric wheel 3 and the second eccentric wheel 4 are respectively provided with drive end portions 6 and 7 for rotating from the outside, and a drive power portion attached to a pedestal portion of the molding apparatus main body 8. 9 and 10 are connected by connecting rods 13 and 14. The connecting rods 13 and 14 are provided with adjusting means 15 for manually changing the length.

FIG. 3 is a sectional view showing the length adjusting means 15 of the connecting rods 13 and 14. The connecting rods 13 and 14 are bisected at the central portion, and the upper half portions 13a and 14a and the lower half portion 1 thereof are
A female screw different from the left screw or the right screw is cut at each end of 3b and 14b. Further, intermediate portions 13c and 14c connecting the upper half portions 13a and 14a and the lower half portions 13b and 14b.
The upper half 13a, 14a and the lower half 13b,
The left and right male threads to be screwed into the female thread of 14b are cut.
By screwing the intermediate portions 13c and 14c into the upper half portions 13a and 14a and the lower half portions 13b and 14b to integrate them, respectively, and by rotating the intermediate portions 13c and 14c, the lengths of the connecting rods 13 and 14 are increased. It has a configuration that can be changed.

With the above configuration and operation, when the mold 1 or the core 2 is replaced, the core 1, the mold 2, the eccentric wheels 3 and 4 for adjusting the wall thickness, and the drive power parts 9 and 10 are defined respectively. The length is adjusted by the length adjusting means 15 so that the connecting rods 13 and 14 can be connected to the drive ends 6 and 7 and the drive power units 9 and 10 of the wall thickness adjusting eccentric wheel. Can be easily connected.

[0021]

As described above, according to the present invention, the connecting rod for connecting the drive end portion of the eccentric wheel for adjusting the wall thickness of the adjusting mechanism and the drive power portion attached to the main portion of the extrusion molding apparatus is provided. Since there is a length adjusting means for manually changing the length of the connecting rod, when the mold or core is replaced,
Set the core metal, mold, eccentric wheel for wall thickness adjustment, and drive power unit at the specified positions, and set the length so that the connecting rod can be connected to the drive end and drive power unit of the eccentric wheel for wall thickness adjustment. The length can be adjusted by the adjusting means to facilitate the connection.

By connecting the above methods, it is possible to easily carry out the initial setting as stipulated. Therefore, the wall thickness distribution of the extruded synthetic resin pipe is measured, and the tip of the mold is automatically set on the core metal based on the calculation. The radial non-uniformity of the synthetic resin pipe wall thickness can be corrected by adjusting the radial deviation of the molten resin flow path in the radial direction of the mold part passage in the circumferential direction.

[Brief description of drawings]

FIG. 1 is a schematic front view of a mold part according to an embodiment.

FIG. 2 is a schematic cross-sectional view of a mold part according to an embodiment.

FIG. 3 is a cross-sectional view of a connecting rod length adjusting means according to an embodiment.

FIG. 4 is a configuration diagram of a molding apparatus.

FIG. 5 is a cross-sectional view of a mold portion of a conventional example.

FIG. 6 is a schematic front view of a mold portion of a prior art.

[Explanation of symbols]

 1 mold 2 core metal 3 first eccentric wheel (wall thickness adjusting eccentric wheel) 4 second eccentric wheel (wall thickness adjusting eccentric wheel) 5 channel width (gap) 6,7 drive end 9,10 drive power Part 13, 14 Connecting rod 15 Length adjusting means

Claims (1)

Claims: 1. The wall thickness distribution of an extruded synthetic resin pipe is measured, and the tip of the mold is automatically moved in the radial direction with respect to the core metal on the basis of the calculation, so that the molten resin An adjusting mechanism of a synthetic resin pipe extrusion molding apparatus that adjusts the circumferential deviation of the radial width of the mold part flow path to correct the circumferential unevenness of the synthetic resin pipe thickness, and the thickness of the adjusting mechanism. The connecting rod that connects the drive end of the adjusting eccentric wheel and the drive power unit attached to the main body of the extrusion molding device has a left / right male screw part and a female screw part that change the length of the connecting rod. A wall thickness adjusting mechanism for a synthetic resin pipe extrusion molding apparatus, comprising a length adjusting means configured by combination.