JPH0764006B2 - Extruder base structure - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die structure of an extrusion molding machine, and more particularly to a die structure capable of applying a coating liquid or a paint to the surface of a molded product at the same time as extrusion molding.

2. Description of the Related Art For example, long strips having the same cross-sectional shape, such as weather strips for automobiles and glass runs, are generally formed by extrusion molding of rubber or synthetic resin, and coating liquid or paint is applied to the surface thereof. There are cases.

As an example, in a glass run having a substantially U-shaped cross section that slidably seals the end face of a windshield of an automobile, in order to reduce sliding resistance on the bottom surface in contact with the windshield and the inner wall surfaces of both seal lips. It is necessary to apply the coating liquid of.

Conventionally, in order to apply the coating liquid, the extrusion-molded glass run is vulcanized, and then the coating liquid is sprayed.

Problems to be Solved by the Invention Therefore, there is a problem that the coating process is a separate process and very troublesome, and that equipment for the coating process is required separately from the extruder. .

In addition, in such a method of applying by spraying, it is difficult to apply it to a necessary portion of the grass run to a minimum,
The coating liquid is consumed excessively and the material cost increases.

Of course, not only the above-mentioned grass run, but also the case where a part of the weather strip or the like is painted in the vehicle body color, the same problem occurs.

Means for Solving the Problems Therefore, the present invention provides a die structure of an extrusion molding machine capable of simultaneously applying a coating liquid or a paint at the stage of extrusion molding. That is, the die structure of the extrusion molding machine according to the present invention is attached to the tip of the extrusion molding machine, and the main die having a material passage having a shape corresponding to the desired shape of the molded product formed through the main die, It is composed of a coating die attached to the outside so that an opening slightly larger than the material passage is formed through the coating die and corresponds to a desired liquid application site of the extrusion molded product. In the range, the inner wall surface close to the shape of the molded product is formed so as to have a slight step with respect to the inner wall surface of the material passage of the main die, and the coating liquid is discharged from the direction perpendicular to the surface of the extrusion molded product. The liquid discharge port is formed in the range corresponding to the liquid application site along the superposition surface of the main spinneret and the coating spinneret so that the liquid discharge port and the liquid supply pipe are connected to each other. The liquid supply passage recessed in the overlapping surface From serial liquid supply pipe is formed to be wider toward the liquid discharge port, further, to the liquid discharge opening neighborhood of the liquid supply passage,
It is characterized in that a rectifying dam portion is provided which rectifies the flow of the coating liquid and serves as a passage resistance.

Action The plasticized material inside the extruder is extruded through the material passage of the main die to be molded into a molded article having a predetermined cross-sectional shape. The molded product extruded from the main die then passes through the opening of the coating die,
At that time, the liquid delivered from the liquid discharge port, for example, the coating liquid or the paint, is continuously applied to the surface of the molded product.

Here, since the flow of the liquid sent out from the liquid discharge port is rectified by the rectifying dam part near the liquid discharge port, the pressure in each part in the width direction of the liquid discharge port becomes uniform, and the coating thickness in each part in the width direction becomes uniform. Becomes uniform. Further, since the liquid supply passage gradually widens toward the downstream side and the rectifying dam portion is located in the vicinity of the liquid discharge port serving as the outlet thereof, pressure change on the liquid supply pipe side, for example, pressure pulsation of the pump is alleviated. . In other words, the pressure change when flowing out from the liquid discharge port becomes small,
The coating thickness becomes uniform in the longitudinal direction.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

This embodiment is an example applied to extrusion molding of a glass run 31 having a substantially U-shaped cross section made of rubber as shown in FIG. 3, and the center surface of the bottom portion 32 and a seal lip which are in contact with a window glass (not shown). The coating liquid 35 is applied to the inner surface of the 33, 34.

FIG. 2 shows a main part of an extrusion molding machine provided with a die structure according to the present invention.

In FIG. 1, reference numeral 1 is a cylinder barrel having a screw 2 therein and supplying a rubber material kneaded by the screw 2, and 3 is a head portion fitted and arranged on the outer periphery of the tip end portion of the cylinder barrel 1. . A breaker plate 4 for rectifying the flow of the plasticized rubber material is arranged at the tip of the cylinder barrel 1. A disc-shaped main die 5 is provided at the tip of the cylinder barrel 1, and a disc-shaped coating die 6 is also provided outside the main die 5. The main die 5 and the application die 6 are closely stacked on each other,
It is attached to the tip of the cylinder barrel 1 by a pressing member 7 that is screwed onto the tip of the head 3. Further, the head portion 3 is provided with a heating cylinder 8 for heating the rubber material by flowing steam or the like.

FIG. 1 is a sectional view showing the details of the main die 5 and the coating die 6, and FIG. 4 shows the front side surface of the main die 5, that is, the right side surface in FIG. . As is clear from these figures, a material passage 9 having a shape corresponding to the cross-sectional shape of the glass run 31 is formed through the main mouthpiece 5. Therefore, the rubber material sequentially pressurized and supplied by the screw 2 is extruded into a predetermined shape through the material passage 9 of the main die 5. In addition, three screw holes 10 are provided in the relatively upper part,
Two positioning holes 11 are recessed in the lower part.

Next, FIG. 5 shows the front side surface of the coating die 6, that is, the right side surface in FIG. 1, and FIG. 6 shows the back side surface of the coating die 6, that is, in FIG. The left side is shown. As is clear from these figures, the coating die 6
Has an opening slightly larger than the material passage 9 of the main mouthpiece 5.
12 is formed through. In addition, in the above-mentioned application site of the coating liquid 35, especially the inner wall surface 12a is the material passage 9
The inner wall surface 9a is accurately machined so as to have a slight step (about 0.5 mm), and in the other portions, the material passage 9 has a considerably large margin. Further, in the relatively upper part of the coating die 6,
Three through holes 13 that match the screw holes 10 of the main mouthpiece 5 are provided, and a positioning pin 14 that fits into the positioning hole 11 of the main mouthpiece 5 is planted at a relatively lower portion thereof. ing. The coating die 6 is positioned with respect to the main die 5 by the fitting of the positioning pins 14 and is integrally fixed by three screws 15 as shown in FIG.

On the other hand, three liquid supply pipes 16 are fixed to the front side of the coating die 6. A groove-shaped liquid supply passage 17 extending from the passage hole 20 connected to the liquid supply pipe 16 to a desired liquid application site is fan-shaped, that is, gradually extends downstream from the communication hole 20 on the back surface of the coating die 6. It is recessed to be wide. The liquid discharge port 18 at the tip of the liquid supply passage 17 has a first
As shown in FIGS. 6 and 6, the inner wall surface 12 a of the opening 12 is open. Further, as shown in detail in FIG. 7, the liquid discharge port 18 portion is formed as a rectifying dam portion so that the groove depth thereof is shallower than the portion of the liquid supply passage 17 near the passage hole 20.
In addition, a large number of groove portions 19 are engraved along the liquid flow direction. The liquid supply pipe 16 is connected to the coating liquid supply device via a rubber tube or the like (not shown),
A coating liquid made of urethane resin or the like is supplied at an appropriate pressure.

Therefore, in the mouthpiece structure having the above structure, the coating liquid supplied from each liquid discharge port 18 is continuously applied to a predetermined portion of the molded product extruded into a predetermined shape through the material passage 9 of the main mouthpiece 5. become. Ie grass run
Extrusion molding of 31 and application of coating liquid can be processed simultaneously.

Further, in the above embodiment, a large number of groove portions 19 are provided in the liquid discharge port 18, and the flow of the coating liquid is rectified here, so that the coating liquid can be supplied uniformly over the entire liquid discharge port 18, That is, the coating thickness of the coating liquid 35 on the glass run 31 can be made uniform in each portion in the width direction. Moreover, since the flow of the coating liquid is throttled to some extent at the liquid discharge port 18 and there is a certain amount of volume on the upstream side, the pressure pulsation of the coating liquid pumped by the pump can be absorbed. It is possible to prevent uneven application in the longitudinal direction of the coating due to pulsation.

Note that FIG. 8 shows an embodiment in which a metal filter 21 is provided as a rectifying dam portion in a portion of the liquid supply passage 17 near the liquid discharge port 18 in order to absorb the above-described pressure pulsation. As the metal filter 21, for example, a woven fiber made of stainless steel, a sintered metal particle of aluminum, brass, copper or the like is used.

In addition, in order to absorb the pressure pulsation in the same manner, FIG. 9 shows a rectifying dam portion at a portion of the liquid supply passage 17 near the liquid discharge port 18,
An embodiment in which a large number of fine rectifying pipes 22 are arranged is shown. Further, instead of the rectifying pipe 22 and the like, as shown in FIG. 10, a rectifying member 23 using a corrugated metal plate may be arranged in the liquid supply passage 17.

Further, in the above embodiment, an example of applying the coating liquid to the glass run 31 has been described, but the present invention is not limited to this, and in various extrusion molded articles, when applying the coating liquid or paint, etc. Can be applied. In particular, it is also applicable to the case where the liquid is applied to the inner peripheral surface of the hollow tubular extruded product.

EFFECTS OF THE INVENTION As is clear from the above description, according to the die structure of the extruder according to the present invention, at the same time as the extrusion molding of the glass run, the weather strip, etc., the coating liquid or the coating material is applied to the die part of the extruder. Can be performed continuously. In particular, by providing the straightening dam portion in the vicinity of the liquid discharge port of the gradually widened liquid supply passage, the coating thickness can be made uniform in both the width direction and the longitudinal direction. Therefore, as compared with the conventional case where the application is performed by spraying, the working process can be remarkably simplified and the equipment for spray application becomes unnecessary. Moreover, it is possible to apply the coating only to a necessary portion to the minimum, and prevent wasteful consumption of the coating liquid and the like. When applied to partial coloring, the boundary with the non-colored part becomes clear,
There is also an advantage that masking is unnecessary.

[Brief description of drawings]

FIG. 1 is a sectional view showing a die structure according to the present invention, a sectional view taken along the line I-I of FIG. 6, and FIG. 2 is a sectional view of an essential part of an extruder equipped with the die structure. FIG. 3 is a cross-sectional view showing an example of a molded product molded by this die structure, FIG. 4 is a plan view showing the front side surface of the main die, and FIG. 5 is a plane showing the front side surface of the coating die. FIG. 6 is a plan view showing the back side surface of the coating die, FIG. 7 is an enlarged perspective view showing a liquid supply passage portion, and FIGS. 8 and 9 are respectively different embodiments of the present invention. FIG. 10 is an enlarged perspective view of the liquid supply passage portion shown in FIG. 10, and FIG. 10 is a perspective view showing an example of a rectifying member. 5 ... Main mouthpiece, 6 ... Coating mouthpiece, 9 ... Material passage, 12
...... Aperture, 16 ...... Liquid supply pipe, 17 ...... Liquid supply passage, 18 ...
… Liquid outlet.

Claims (1)

[Claims] 1. A main die attached to the tip of an extruder and having a material passage having a shape corresponding to a desired shape of a molded article formed therethrough, and a coating attached to the outer side of the main die. The coating die is formed with a slightly larger opening than the material passage, and the material passage of the main die is formed in a range corresponding to the desired liquid application site of the extrusion molded product. A main die and a coating die are formed so that the inner wall surface is formed close to the shape of the molded product so as to have a slight step with respect to the inner wall surface, and the coating liquid is discharged from the direction perpendicular to the surface of the extrusion molded product. A liquid discharge port is formed in the range corresponding to the liquid application site along the overlapping surface of the liquid supply port, and the liquid supply port is recessed in the overlapping surface so as to connect the liquid discharge port and the liquid supply pipe. When the passage goes from the liquid supply pipe to the liquid discharge port And a rectifying dam part that rectifies the liquid flow of the coating liquid and serves as a passage resistance in the vicinity of the liquid discharge port of the liquid supply passage. Extruder base structure.