JPS5970528A - Extrusion forming method and apparatus - Google Patents

Abstract

PURPOSE:To make it possible to manufacture a formed product having no joint by such an arrangement wherein an extracting opening of specified shape is formed in a basic forming die and a movable die is arranged at the front edge surface of the opening and the shape of resin to be extruded is changed by sliding the movable die. CONSTITUTION:A basic forming die 2 is composed of an extrusion opening 6 of which internal circumference has a specified extrusion shape 5. A movable die 7 is slidably brought to contact with the front edge 8 of the opening 6 and its lower end is connected to a piston rod 11. As the movable die 7 is caused to slidably ascend by a drive unit 10, the extrusion shape 5 is gradually closed from its lower end and it eventually becomes such a condition wherein a small lip part 5a is almost eliminated at the highest position. In other words, an extrusion formed product can be continuously formed without joint. Even when the shape of cross section of an extrusion formed product is changed depend on the change of extrusion length of each section, there is no necessity for using a different die for each section and joining plural pieces of extrusion formed products, unlike the conventional method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an extrusion molding method and apparatus for manufacturing an extrusion molded product having a variable cross-sectional shape, such as a weather strip for an automobile. Conventionally, as shown in FIG. 1, the Uesane trip 20, which is cut off from the periphery of an automobile door 19, has different cross-sectional shapes depending on its several sections, that is, the section A between points A is shown in FIG. The section B between point A and point C has a cross-sectional shape as shown in Figure 3e, and the section C between point B and C has a cross-sectional shape as shown in Figure 4. It changes gradually to B.

Therefore, parts A, B are made by separate extrusion, and part C is made by molding, and these are a.

b, (!) are vulcanized and joined at each point.

Therefore, each part A, i3. C. Not only does it take a lot of work to join, but it also tends to crack during handling due to a decrease in the strength of the joint, or create gaps in the joint. .

In addition, since they are extruded or molded separately, they each require a die, a mold for molding, and a mold for joining, resulting in high production costs.

This invention was made in order to eliminate the drawbacks of the conventional extrusion molding method as described above.

A first embodiment of the present invention will be described based on FIGS. 5 and 6.

1 is the head of a normal extrusion molding machine, and the extrusion molding material is passed through the basic molding die 2. lead to. The basic molding die 2 is fixed to the tip of the head 1 by a threaded presser foot 3, and has an inlet portion 4 having a tapered inner periphery and an extrusion opening 6 having a predetermined extrusion shape 5.

In the weatherstrips shown in FIGS. 1 to 4, the extruded shape 5 is similar to that shown in FIG. 3, but is formed so that the small lip portion 5a is positioned downward.

Reference numeral 7 denotes a long plate-shaped movable die, which is guided by a gate-shaped guide portion 9 fixed to the lower part of the front end surface 8 of the extrusion opening 6, and is arranged so as to be in sliding contact with the front end surface 8.

10 is a cylindrical drive device, and pinuton rod 11
is connected to the lower end of the movable dial by a pin 12, and the piston 13 is configured to move up and down by hydraulic or pneumatic pressure.

Then, the extrusion molding machine is activated and the movable diamond is at its lowest position as shown in FIG.
When the J-tube is extruded, its cross-sectional shape is similar to that shown in FIG. 3, and in FIG. 1, 4 corresponds to the portion Bi between point a and point C.

Next, when the movable diamond gradually slides upward due to the operation of the drive device 10, the extruded shape 5 is gradually closed from the lower end of the small lip portion 5a, and the weather metal 1j that is extruded during that time is the fourth It becomes as shown in the figure, and corresponds to the part C between point b and point C in FIG.

When the movable diamond is in the uppermost position, the cross-sectional shape of the weather strip has almost no small lip portion 5a as shown in FIG. 2, and corresponds to the portion A between point a in FIG.

In other words, the extrusion molded product is extruded from the extrusion opening 6 while changing its cross-sectional shape continuously from that shown in FIG. 3 to that shown in FIG. Nutrip can also be extruded seamlessly and continuously.

A second embodiment of the present invention will be explained with reference to FIGS. 7 to 10.

In this embodiment, only the movable die 14 is different from the movable die of the first embodiment, and most of the other components are the same. The movable die 14 has an elongated temporary shape and slides into contact with the front end surface 8 of the extrusion opening 6 by means of a pin 15 screwed in the middle part.
The left end is connected to the pinuton rod 11 by a pin 12.

Further, the extruded shape 16 differs from the first embodiment in that a downward protrusion 17 is provided on the semicircular string-side centerpiece.

The right end 18 of the movable die 14 is rotated by the operation of the drive device 10, and when the right end 18 is at the lowest position, the cross-sectional shape of the extruded product becomes as shown in FIG. 9, with the right end 18 pointing upward. When the protrusion] 7 is closed, the cross-sectional shape of the extruded product becomes as shown in FIG.

As mentioned above, in the first aspect of the present invention, the basic molding die 2 is formed with a predetermined shape 5, 1, and the front end surface 8 of the extrusion opening 6 is provided with a movable die.

14 are disposed so as to be in sliding contact with each other, and the movable diamond 14 is slid by the drive device 10 to form the extruded shape 5 of the extrusion opening 6.
This is an extrusion molding force/method in which the cross-sectional shape of the extrusion molded product can be changed according to the difference in extrusion length by appropriately changing 16.

Further, the second invention of the present invention is such that a predetermined extruded shape 5, 16 is formed on the basic molding die 2, and a movable diamond 4 is slidably contacted with the front end surface 8 of the extrusion opening 6 (disposed). 7. This is an extrusion molding apparatus equipped with a drive device 10 that can slide the movable dies 7 and 14 so as to change the extruded shape of the extrusion opening 6 by 5 degrees 10 as appropriate.

According to the present invention, even when the cross-sectional shape of the extrusion molded product changes depending on the extrusion length, the conventional
``Separate dies and molds are not required, and there is no need to join multiple extrusion molded products, making it possible to create seamless extrusion molded products using only extrusion molding.'' Therefore, there is no need for labor, dies, or molds for connection as in the past, making the manufacturing process cheaper, and there are no drawbacks such as poor sealing performance or reduced strength due to gaps created at the joint. There are 5 features.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the conventional extrusion molded product in its removed state, Fig. 2 is a vertical cut front view of the same extrusion molded product at section B+, and Fig. 3 is an extruded acid J shown in Fig. 1. Cedar 1 is a perspective view of part C of the extrusion molded product shown in Figure 1. 5 to 10 are for explaining the extrusion molding method and the same apparatus according to the present invention. FIG. 5 is a front view showing the first embodiment of the present invention, and FIG. 6 is a vertical cut side view of the same. 9 is a front view showing the second embodiment of the present invention, FIG. 8 is a vertical cut side view of the same, and FIGS. 9 and 10 are views showing the cross-sectional shape of the extrusion molded product. It is. 2 Basic molding die 5 Predetermined extrusion shape 6 Extrusion opening 7 Movable die 8 Front end surface], fJ Drive device 14 Movable die 16 Predetermined extrusion shape Patent Applicant Agent of Nishikawa Rubber Industries Co., Ltd.
Person Patent Attorney Furu H] Kei Tsuyoshi Figure 7 Figure q Figure 8 Figure 10

Claims (1)

[Claims] 1. Extrusion amount 11 having a predetermined extrusion shape in the basic molding die
A movable die is arranged so as to be in sliding contact with the front end face of the extrusion opening, and the movable die is slid by a drive device to appropriately change the extrusion shape of the extrusion opening, thereby forming an extrusion molded product. An extrusion molding method characterized in that the cross-sectional shape can be changed depending on the extrusion length. 2. An extrusion opening having a predetermined extrusion shape is formed in the basic molding die, and a 5J moving die is arranged so as to be in sliding contact with the front end surface of the extrusion opening, so that the extrusion shape of the extrusion opening can be changed as appropriate. An extrusion molding device characterized by being provided with a drive device that can slide and move a movable die.