JPS58220717A - Manufacturing method and equipment for extruded product having corner part - Google Patents

Abstract

PURPOSE:To shape the corner part having a smaller radius of curvature at the side where a material feeding is less, by inserting a corss-sectional area adjusting member in the connecting hole of a heat near the die and making the amount of plastic material fed to the orifice of a die not uniform in a cross- sectional direction. CONSTITUTION:A penetrating hole 22 which crosses at a right angle to a connecting hole 21 is shaped at the peripheral wall of an extruder head 2 near a die 3 and the movable pin 5 of a cross-sectional area adjusting member is fitted. When the tip of the movable pin 5 protrudes in the connecting hole 21 and covers a part of the orifice 31 of the die 3, a velocity difference is generated to the part of the orifice uncovered by the movable pin 5 and an extruded product curves to the side covered by the movable pin 5. The nearer the tip of the movable pin 5 approaches to the central axis of the connecting hole 21, the larger becomes the velocity difference of the orifice part and the smaller becomes the radius of curvature of the obtained extruded product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an extruded product of rubber or plastic having a corner portion, and an apparatus for manufacturing the same.

Generally, extrusion molding of plastic materials involves continuous production of linear products. As a cylindrical extrusion molding with a constant radius of curvature, the center core of the die is shifted to one side in the normal direction, and one side of the ring-shaped slit is made thinner than the other. A method for manufacturing a tubular body is known. Since this method bends the extruded material by changing the width of the die slit, it can only be applied to die with simple slits. 2 The manufacturing method and apparatus of the present invention can produce curved extruded products with any radius of curvature, extruded products with only partially curved corners, and extruded products with corner parts with varying radius of curvature, regardless of the slit shape of the die. A product can be manufactured.

That is, the method of manufacturing an extruded product having a corner portion of the present invention involves continuously extruding a plastic material such as rubber or plastic plasticized in an extruder into a communication hole in an extruder head, and Pass through a die or orifice fixed at the tip of the

In a method for manufacturing an extruded product in which a cross-sectional shape is formed by The present invention is characterized in that the amount of plastic material to be supplied is non-uniform in the cross-sectional direction, and a corner portion is formed with a small radius of curvature on the side where the proportion of plastic material supplied is small. In addition, the device of the present invention is inserted into a communicating hole of an extruder head near a die, or is inserted into the communicating hole to change the cross-sectional area of a flow path in a portion near one side circumferential wall of the communicating hole. It is characterized by comprising a member.

In the present invention, a cross-sectional area adjusting member inserted into a communication hole in an extruder head near the die changes the proportion of plastic material supplied to the orifice of the die, thereby bending the extruded product. Therefore, in the present invention, a conventional die can be used as is. Furthermore, by rotating the insertion amount of the cross-sectional area adjusting member or rotating the cross-sectional area adjusting member, the proportion of the plastic material supplied to the orifice of the die can be arbitrarily changed. This makes it possible to create corners in the middle of a straight line or to create extruded products with different radii of curvature.

The cross-sectional area adjusting member may be one that changes the proportion of plastic material supplied to the orifice of the die depending on the insertion amount of a rod-shaped member inserted into the communication hole of the extruder head. Alternatively, the cross-sectional area adjusting member may be plate-shaped, and the plate-shaped cross-sectional area adjusting member inserted into the communicating hole may be rotated within the communicating hole to change the proportion of the plastic material supplied to the orifice of the die.

The number of cross-sectional area adjusting members provided in the extruder head may be one or two or more.

Examples will be explained below.

FIG. 1 shows a cross section of a main part of the device used in the embodiment of the present invention, and FIG. 2 shows the positional relationship between the die and the cross-sectional area adjusting member.

This equipment is a conventional plasticizing extruder for rubber and plastics.
and an extruder head 2 forming the discharge part of this extruder 1,
and a die 3 fixed to the tip of the extruder head 2 with a die presser 4. The extruder head 2 is provided with a communication hole 21 along a solid shaft through which the plasticized material passes, and is coaxially connected to the discharge port of the extruder by a flange. At the tip of the extrusion-like head 2, a circular recess is formed around the open end of the communication hole 21, and a disc-shaped die 3 is coaxially arranged at the bottom of the circular recess so as to close the opening of the communication hole 21. , has a large central opening, and a peripheral wall at the end of the opening is pressed and fixed by a protruding ring-shaped die holder 4.

A wire passage hole 22 that is perpendicular to the communication hole 21 is formed in the peripheral wall of the extruder head 2 near the die 3, and a rod-shaped movable pin 5 corresponding to a cross-sectional area adjustment member is fitted into this through hole 22. . A rack 501 is formed on the side surface of this movable pin 5, and a gear box 5 is fixed to the outer peripheral surface of the extruder head 2.
It meshes with a pinion 52 which is slidably held at 1. This movable pin 5 slides up and down in FIGS. 1 and 2 by rotating the nion 52. FIG. and movable pin 5
Indicates the positional relationship between FIG. 2 shows a state in which the tip of the movable pin 5 protrudes near the solid axis of the communication hole 21, and the tip of the bottle 5 covers the lower half of the orifice 31 of the die 3.

To produce extruded products with corners using this equipment,
The extruder 1 is operated in exactly the same way as in normal extrusion molding, and the plasticized material is continuously extruded into the communicating hole of the extruder head 2, and roughly sent to the orifice 31 of the die, forming the shape of the orifice 31. Molding to produce continuous rod-shaped extruded products. In this case, the tip of the movable bottle 5 is
The orifice 3 of the die 3 protrudes into the communication hole 21 as shown in the figure.
1, the flow of plastic material into the orifice portion covered by the movable pin 5 is reduced, and the orifice passing speed of that portion becomes I. Therefore, a speed difference occurs between the extruded product and the orifice portion not covered by the movable bottle 5, and the extruded product is bent toward the side covered by the movable bottle 5. The closer the extension of the movable bottle 5 is to the solid axis of the communication hole 21, the greater the speed difference in the orifice portion becomes, and the radius of curvature of the obtained extruded product becomes smaller. Note that if extrusion molding is performed with the tip of the movable bottle 5 retracted into the communication hole 2a, a normal linear extruded product will be obtained. Therefore, in order to produce an extruded product having a straight part and a corner part, the movable bin 5 must be used only when forming the corner part.
When projecting into the communication hole 21 to form a straight portion, the movable bottle 5 is returned.

The cross-sectional area adjusting member of the present invention may be as shown in FIGS. 3 and 4.

Here, a horizontal through hole 23 whose central axis is below the central axis of the communication hole 21 is formed on the wall surface of the extruder head 2 near the die 3.
A movable bottle 5, which is the same as that shown in FIG. 1, is fitted therein so as to be slidable in the axial direction.

FIG. 4 corresponds to FIG. 2 of the above embodiment, in which the movable bottle 5 protrudes into the communication hole 21 and the lower part of the orifice 31 of the die 3 is covered with the movable bottle 5.

This causes the extruded product to bend downward as shown in FIG. Figure 31. In the cross-sectional area adjusting member shown in FIG. 4, the radius of curvature of the square portion is approximately constant.

Still other cross-sectional area adjusting members are shown in FIGS. 5 and 6.

This equipment has a communication hole 21 on the upper side of the wall surface of the extruder head 2.
A vertically extending through hole 23.
24 is the installation number, and a bin 6 that can rotate around the axis is installed in each through hole.
．． 7 are respectively fitted. The bottle 6.7 has a plate-shaped tip 61.71 and a rod-shaped base 62.72, and the tip projects into the communication hole 21 of the extruder head 2. This cross-sectional area adjusting member rotates the bottle 6.7 and makes the direction of the plate surface of the plate-shaped tip part 61.71 parallel or perpendicular to the axial direction of the communication hole 21, thereby causing the flow inside the communication hole 21. The flow speed of the plastic material is changed to change the speed of the plastic material on both the left and right sides of the orifice 31 of the die 3 to produce an extruded product bent in a fixed direction.

In the state shown in FIG. 6, the tip 71 of the bottle 7 is
Since the orifice 61 of the die 3 is covered more than the tip 61 of the die 3, the flow of the plastic material on the left side in FIG. 6 is poor, and an extruded product bent to the left is manufactured.

With this cross-sectional area adjusting member, by changing the rotation angle of the bin 6.7, it is possible to produce an extruded product having a corner portion curved to the right as well.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part of the apparatus shown in the embodiment of the present invention, FIG. 2 is a diagram showing the positional relationship between the die 3 and the movable bin 5 of the apparatus of FIG. 1, and FIG. A sectional view of the main parts of the device, No. 4
The figure shows the positional relationship between the die 3 and the movable bin 5 in FIG.
FIG. 5 is a sectional view of a main part of still another apparatus of the present invention, and FIG. 6 is a diagram showing the positional relationship between the die 3 and the bottle 6.7 in FIG. 5. 1... Extrusion II 2... Extruder head 3... Die 4...
Die presser 5...Movable bottle 6.7...
...Bin patent applicant Toyoda Gosei Co., Ltd. agent Patent attorney Hiroshi Okawa Patent attorney Fujitani Patent attorney Akio Maruyama Figure 1 Figure 2 Figure 4

Claims (4)

[Claims] (1) Continuously extruding a plasticized plastic material such as rubber or plastic into a communication hole in an extruder head and passing it through the orifice of a die fixed at the tip of the extruder head through the communication hole. In the method of manufacturing an extruded product in which a new shape is formed by A method for manufacturing an extruded product having a corner part, characterized in that the amount of material is made non-uniform in the cross-sectional direction, and a corner part is formed with a small radius of curvature on the side where the supply ratio of plastic material is low. (2) The manufacturing method according to claim 1, wherein the radius of curvature of the corner portion is changed by changing the insertion amount of the cross-sectional area adjusting member inserted into the communication hole of the extruder head. (3) The manufacturing method according to claim 1, wherein the radius of curvature of the corner portion is changed by rotating the cross-sectional area adjusting member inserted into the communication hole of the extruder head. or 1. An apparatus for manufacturing an extruded product having a corner portion, comprising a cross-sectional area adjusting member that is inserted into the communicating hole and changes the cross-sectional area of the flow path in a portion close to one peripheral wall of the communicating hole.