JP2888591B2 - Extruded product manufacturing equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for extruding an extruded product having a uniform cross section, such as an automobile weather strip.

2. Description of the Related Art For example, as shown in FIG. 4, in an automotive weather strip 30 having a hollow lip 31 and a sealing lip 32, a method for manufacturing the same is as follows.
The rubber material is extruded together with 33 to extrude an intermediate molded product 34 as an extruded product as shown in FIG. 5, and the welted portion 35 is bent into a substantially U-shape in a subsequent bending process to form the fourth molded product. Finished to the product shape shown in the figure.

In such a weather strip 30, as shown in FIG. 4, the grooved groove 36 of the welt portion 35 is fitted to the flange portion 38 of the vehicle body panel 37, and at the same time, the seal lip 32 is elastically contacted with the vehicle body panel 37. By weather strip 30
Although the original function is exhibited, a part of the seal lip 32 is cut off in an arc shape as shown in FIG. May need to be formed.

In such a case, as shown in FIG. 8, a cutter 44 comprising a holder 42 and a blade 43 is arranged on the front side of the base 41 of the extrusion head 40 from which the intermediate molded product 34 is extruded, and this cutter 44 is used as a guide member. The drive unit 46 moves the vehicle forward and backward in the direction of arrow A while guiding at 45.
As shown in the figure, a part of the seal lip 32 is cut off. The blade 43 of the cutter 44 has a streamlined cross section as shown in FIGS. 9 and 10. In addition, base 41
Has an opening 47 corresponding to the cross-sectional shape of the intermediate molded product 34.

That is, the cutter is driven at a predetermined timing and speed in synchronization with the extrusion operation of the intermediate molded product 34 from the base 41 in FIG.
44 is fed in the direction of arrow A. As a result, as shown in FIG. 7, the blade 43 of the cutter 44 enters the seal lip 32 immediately after being extruded in the order of a, b, c, d, e, f, and after a predetermined time elapses, the blade 43 Is removed from the seal lip 32 again, and a part of the seal lip 32 is cut off in an arc shape as shown in FIG.
59-114040 and JP-A-61-230930).

Problems to be Solved by the Invention In the conventional structure, since the blade 43 of the cutter 44 is fixed to the holder 42, the blade 43 enters the seal lip 32 as apparent from FIG. The direction of the blade 43 does not change at all until it comes out.
Therefore, once the blade 43 enters the seal lip 32, there is no particular problem.However, when the blade 43 enters the seal lip 32 and when the blade 43 comes out of the seal lip 32, a large resistance is added. 39 (FIG. 6) start end 39a and end end 3
The sharpness in 9b deteriorates and a good cut surface cannot be obtained,
The appearance quality cannot be improved. In particular, the intermediate molded product 34 is a base
As soon as the blade 43 escapes from the opening 47 and is released from the restraint of the opening 47 and expands (referred to as a die swell), the starting end of the cutout 39 into which the blade 43 enters immediately after exiting from the opening 47. The above phenomenon is remarkable about 39a.

The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce the resistance when a part of an extruded product is cut by a cutter as much as possible so that a cut portion can be formed. An object of the present invention is to provide a structure capable of obtaining a good cut surface.

Means for Solving the Problems The present invention extrudes a molding material from a die of an extrusion head to extrude an extruded product having a predetermined cross-sectional shape, and a cutter arranged on the front side of the die has a plane parallel to the front surface of the die. In the apparatus which cuts off a part of the extruded product immediately after molding by moving forward and backward in the apparatus, the blade of the cutter is formed in a streamlined cross section, and the blade is moved in the forward and backward movement direction of the cutter. It is characterized by being configured to be capable of swinging displacement about a right-angled axis as a rotation center.

Operation According to the above structure, a good cut surface can be obtained because the resistance between the cutter and the extruded product immediately after the blade is formed changes the direction autonomously in a direction in which the resistance becomes as small as possible. Will be able to

Embodiment FIGS. 1 and 2 show an embodiment of the present invention.
With respect to the cutter 1 composed of the holder 2 and the blade 3 having a streamlined cross section, the blade 3 is rotatably supported on the holder 2 via a hollow shaft 4 made of an insulator. Nichrome wire 5 for heating
Has been inserted.

That is, the hollow shaft 4 is inserted and fixed to a portion of the blade 3 close to the cutting blade 6, and both ends of the hollow shaft 4 are rotatably inserted into and supported by the legs 7 of the holder 2 as bearings, while the hollow shaft 4 is supported. Both ends of the nichrome wire 5 inserted into the wire 4 are connected to a power source (not shown) via a terminal plate 8 pressed against the wire. Therefore, the blade 3 is heated by the electrothermal action of the nichrome wire 5.

According to such a structure, as shown in FIG.
The cutter 1 is synchronized with the extrusion operation of the intermediate molded product 34 from 41.
When the cutter 1 is pressed against the sealing lip 32 by giving a downward feed to the cutting lip 32, the center of rotation of the blade 3 is located closer to the cutting edge 6 than its rear end, so that as shown in FIG. Is strongly pressed against the seal lip 32 immediately after molding.

When the blade 3 is pressed against the seal lip 32, the blade 3 is in a direction in which the resistance is reduced, that is, in a forwardly inclined position, due to the frictional resistance between the blade 3 and the seal lip 32 caused by the extrusion in addition to the above-described feed. While being autonomously rotationally displaced (the state of FIG. 3A), the seal lip 32 is smoothly cut into the seal lip 32 from the start end 39a in FIG.

Once the blade 3 enters the seal lip 32, the blade 3 autonomously moves in a direction in which the resistance associated with cutting is reduced due to the feed amount given to the blade 3 and the movement of the seal lip 32 accompanying extrusion. The cutting operation of the seal lip 32 proceeds while changing the direction (b, c, d in FIG. 3).

Then, when the blade 3 has passed the deepest portion of the cut portion 39, the blade 3
Will be given an upward feed instead of the previous downward feed, but at this stage, the blade 3 will be rotationally displaced so as to gradually assume the backward tilting posture, and eventually remain in the backward tilting posture. The cutting operation of the seal lip 32 is completed after exiting from the seal lip 32 (e, f, g, h states in FIG. 3).

Here, in the cutting process of the seal lip 32 as described above, the blade 3 itself is made of Nichrome so that the temperature of the blade 3 becomes higher than the temperature of the intermediate molded product 34 immediately after extrusion by several tens of degrees or more. Since the heating is performed by the wire 5, the sharpness of the cut portion 39 is improved due to the vulcanization promoting action of the cut surface of the cut portion 39 due to the heating action of the blade 3, in addition to the temperature difference as described above. Improve further.

Advantageous Effects of the Invention As described above, according to the present invention, the blade of the cutter is configured to be capable of oscillating displacement, so that the blade is autonomously oscillatingly displaced in the direction in which the resistance accompanying the resection is small during the resection process of the resection portion. As a result, the sharpness of the cut portion is improved and the cut surface of the cut portion is finely finished, which can greatly contribute to the improvement of the appearance quality of the cut portion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged perspective view of a main part of a cutter showing one embodiment of the present invention, FIG. 2 is a perspective view showing details of a main part of FIG. 1, and FIG.
The figure is an explanatory view showing the relationship between the intermediate molded product and the blade, and FIG.
FIG. 5 is a cross-sectional view of a weather strip for an automobile, FIG. 5 is a perspective view showing a form of an intermediate molded product of the weather strip of FIG. 4, FIG. 6 is a perspective view showing a form of an intermediate molded product having a cutout portion, FIG. 7 is an explanatory view showing the relationship between the intermediate molded product and the blade in FIG. 6, FIG. 8 is a front view of the extrusion head, FIG. 9 is an enlarged perspective view of a main part of the blade of the cutter in FIG. The figure is a cross-sectional view along the line BB in FIG. 1 ... cutter, 3 ... blade, 4 ... hollow shaft, 6 ...
... Cutting blade, 32 ... Seal lip, 34 ... Intermediate molded product as extruded product, 39 ... Cutting part, 40 ... Extruded head, 41 ...
... the base.

Claims (1)

(57) [Claims] An extruded product having a predetermined sectional shape is extruded by extruding a molding material from a die of an extrusion head, and a cutter disposed on a front side of the die is moved forward and backward in a plane parallel to the front surface of the die. In the apparatus which cuts off a part of the extruded product immediately after molding, the blade of the cutter is formed in a streamlined cross section, and the blade is rotated about an axis perpendicular to the direction of forward and backward movement of the cutter. An extruded product manufacturing apparatus characterized in that it is configured to be capable of swinging displacement.