JP3205822B2 - Sectional shape variable extrusion molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion molding method capable of changing a part of a cross-sectional shape in a longitudinal direction when extruding a weather strip or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 1, in extruding an extruded product such as a weather strip in which a hollow portion 70 is integrally joined to a trim 60 having a U-shaped cross section, for example, The position, angle, length, and thickness of the projection 71 provided on the surface of the hollow portion 70 and the lip 61 and the claw 62 protruding from the surface and the inner surface of the U-shaped trim 60 by changing the portion in the longitudinal direction. varying the the like, molding the extrusion, the extruder mouth Kanade opening forming protrusion 71 lip 61
It can be implemented by covering or not covering the formed portion of the claw 62 or the like with a movable movable shielding plate, a cutter knife, or the like. Further, for changing the cross-sectional shape of the body of the hollow portion 70 as shown in FIG. 2 in the middle of the longitudinal direction, the hollow portion movable roller or against the 70 body that is extruded from the mouth Kanade opening of the extruder A method has been proposed in which a plate is hit and crushed to deform it.

However, in the above-mentioned conventional extrusion molding method, when a roller or a contact plate is applied to the main body of the hollow portion 70 and the user tries to crush the same, the squeezing deforms in a direction perpendicular to the crushing direction. There is a problem that it is not practical because not only the portion to be deformed but also the portion that should not be deformed (extend, bulge, curve, etc.).

[0004]

The problem to be solved is that, in the above-mentioned conventional extrusion molding method, when a roller or a contact plate is applied to the main body of the hollow portion 70 and the member is to be crushed, the crushing direction is reduced. This is not practical because not only the portion that should be squashed and deformed but also the portion that should not be deformed deforms (protrudes, bulges, curves, etc.).

[0005]

Means for Solving the Problems The present invention provides a hollow part 70
Is a cross-sectional shape variable extrusion method capable of changing a part of a cross-sectional shape of an extruded product 50 having a longitudinal direction, wherein the core 30 forming a hollow portion 70 whose cross-sectional shape is to be changed is formed. divided in a fixed core 31 and movable in the core 32, causes parallel to advance and retract the movable wick 32 in the extrusion direction of the extrudate 50, so as to correspond to the movement of said movable in the core 32,
The movable shielding plate 20 provided so as to cover the hollow portion forming portion at the outlet of the base 10 is moved forward and backward in a direction perpendicular to the extrusion direction of the extruded product 50.

[0006]

Embodiment An embodiment will be described with reference to the drawings.
Reference numeral 0 denotes a mouthpiece for extruding an extruded product 50 having a hollow portion 70 from an extruder, and reference numeral 20 denotes a movable shielding plate provided so as to cover a hollow portion forming portion at an outlet of the mouthpiece 10. It can move back and forth in the vertical direction. Numeral 30 denotes a core forming a hollow portion 70 whose cross-sectional shape is to be changed, and includes a fixed core 31 and a movable core 32 which advances and retreats in parallel with the extrusion direction of the extruded product 50. Note that the movable core 32 may not be a single piece of metal but may be a plurality of round bars, pipes, square bars, or the like, and the whole may be formed into a predetermined shape, and each may be moved differently one by one. Others 21 and 3
Reference numeral 3 denotes a driving device such as a motor, an air cylinder, or a pulse motor that drives the movable shielding plate 20 and the movable core 32.
The character-shaped trim, 61 and 62 are lips and claws projecting from the surface and the inner surface of the U-shaped trim 60, 71 is a projection provided on the surface of the hollow portion 70, 80 is a mandrel, and 81 is the trim 60. It is a mandrel for supplying a core to be buried.

The operation will be described with reference to the drawings.
While extruding rubber or resin from zero, the movable cores 32 are respectively advanced and retracted in parallel with the extrusion direction of the extruded product 50 by the driving machines 21 and 33 connected to a computer (not shown), When the shielding plate 20 is advanced and retracted in a direction perpendicular to the extrusion direction of the extruded product 50, the cross-sectional shape of the hollow portion 70 can be continuously changed in the longitudinal direction.

[0008]

Since the present invention is configured as described above, when extruding the extruded product 50 having the hollow portion 70, a portion of the cross-sectional shape which must not be deformed is changed without change. It has become possible to easily change the portion to be made into a predetermined shape continuously in the longitudinal direction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an extruded product that can easily change a cross-sectional shape in a longitudinal direction according to a conventional technique.

FIG. 2 is a cross-sectional view showing an example of an extruded product in which it is difficult to change a cross-sectional shape in a longitudinal direction by a conventional technique.

FIG. 3 is a sectional view showing an embodiment of an extruder to which the present invention is applied.

FIG. 4 is a front view showing an embodiment of an extruder to which the present invention is applied.

FIG. 5 is a partial cross-sectional view showing a state in which the movable core is advanced and the movable shielding plate is retracted in the embodiment of the present invention.

FIG. 6 is a partial cross-sectional view showing a state where the movable core is retracted and the movable shielding plate is advanced in the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 base 20 movable shielding plate 21 driver 30 core 31 fixed core 32 movable core 33 driver 50 extruded product 60 trim 61 lip 62 claw 70 hollow portion 71 protrusion 80 mandrel 81 core mandrel

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-31784 (JP, A) JP-A-5-138714 (JP, A) JP-A-56-157325 (JP, A) JP-A-4- 365621 (JP, A) JP-A-4-107119 (JP, A) JP-A-4-185419 (JP, A) JP-A-4-356219 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) B29C 47/00-47/96

Claims (1)

(57) [Claims] 1. An extruded product (5) having a hollow portion (70).
In the cross-sectional shape variable extrusion method in which a part of the cross-sectional shape of 0) can be changed in the longitudinal direction, a core (30) for forming a hollow portion (70) whose cross-sectional shape is desired to be changed.
Is divided into a fixed core (31) and a movable core (32), and the movable core (32) is advanced and retracted in parallel with the extrusion direction of the extruded product (50), and the movable core (32) is A cross section in which a movable shielding plate (20) provided so as to cover a hollow portion forming portion at an outlet of a mouthpiece (10) is advanced and retreated in a direction perpendicular to the extrusion direction of an extruded product (50) in accordance with the movement. Variable shape extrusion molding method.