JP3273190B2 - Method and apparatus for manufacturing weather strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a weather strip for an automobile, and more particularly to a weather strip having a seal portion at a tip end, the length of a portion continuous to the seal portion being changed at a constant width. And a method and apparatus suitable for manufacturing a weatherstrip for an automobile.

[0002]

2. Description of the Related Art Conventionally, in a method of manufacturing a weather strip, a method of changing the cross section of an extruded product in the middle includes (1) a method of changing the extrusion discharge amount by changing the number of revolutions of an extrusion screw (Japanese Patent Laid-Open No. Hei. No. 1922), (2) A method in which a movable section is provided as an accessory to an extrusion die and the cross section of the die outlet is changed by moving the movable section (Japanese Patent Laid-Open No. 59-114040).
(3) A method of dividing the extruded product immediately after the outlet of the extrusion die into a product shape and a surplus by providing a second movable die (Japanese Patent Application Laid-Open No. Sho 61-230930). There is known a method in which a knife is continuously partially cut with a knife to change it.

[0003]

However, in the method (1), it is difficult to change a partial cross section because the cross section of the extrusion changes to a similar shape. In the method (2), it is possible to change a part of the cross section, but other than the cross section in which the change in the cross-sectional area at the mouth of the die affects the change in the back pressure in the extruder pushed from the screw. There is a problem that the desired shape cannot be obtained due to the change of the die well in a portion that is not desired to be changed.

Further, in the method (3), since the extruded tab is mechanically divided immediately after the die exit, the pressure in the extruder acts non-uniformly on the division boundary, and the division surface does not form a smooth surface. There is a concern that the commercial value of the product may be reduced, and there is a restriction on the shape to be changed, and in particular, a shape with a thin tip seal portion or a shape with a hollow portion at the tip seal portion cannot be used. There is a problem that the field is limited.

[0005] In the method (4), the product which expands or contracts in the longitudinal direction of the product after the extrusion cannot always be controlled to have a constant cross-sectional area. In particular, products extruded with a cored bar are limited to the manufacture of products that do not expand and contract in the length direction. Also, wear and deformation of the knife used for cutting are predicted, and there is no problem with maintenance. There is a disadvantage that the tip part can be changed in the cross section of the product, but the middle part of the cross section cannot be changed, and each of the above-mentioned methods has a disadvantage in producing a wide range of weather strips whose width changes in the length direction. In addition, there was room for improvement.

The present invention addresses the above-mentioned situation, and particularly focuses on the back pressure in the extruder extruded from the screw, and opens the product side opening before the viscous elastomer material exits the extrusion die. Divided into back pressure adjusting apertures and found to distribute back pressure appropriately, and have a seal lip at the tip and a thin seal lip at the tip, a bent seal lip, and a hollow part It is an object of the present invention to accurately obtain a weatherstrip having various shapes such as a seal lip and a portion continuous to a seal portion and having a fixed width.

[0007]

Thus SUMMARY OF THE INVENTION The feature of the present invention for achieving the above object, the adjustment of the extrusion die just before the back pressure of the basic width is changed in the length direction, product accuracy Required
In producing the required weather strip, the molded body is extruded through a product opening of an extrusion die at an extruder tip,
A viscous elastomer immediately before extrusion, which is caused by adjusting the opening area of the product opening by a sliding member in accordance with a change in the width of the weather strip and by adjusting the opening area of the mass hole by sliding of the sliding member. The back pressure of the material is detected, and the back pressure is measured simultaneously with the product opening and the change in the area of the opening.
In this method, the distribution rate of the elastomer to each opening is adjusted by distributing the pressure to the back pressure adjusting opening whose area changes in inverse proportion . Further, as an apparatus for the present invention for manufacturing the weather strip, and the base plate having a product opening the extrusion die attached to the extruder tip, the open area of the product openings in the mouth gold plate front It is constituted by a sliding member slidably provided so as to be adjustable, and the product opening hole is formed.
Area change in inverse proportion to quantity simultaneously in conjunction with area change
Provide a back pressure adjustment opening to be changed, and a pressure sensor is attached to the base plate facing the opening, and when the pressure sensor detects a pressure change by connecting the pressure sensor to a control device,
A configuration in which the opening area of the back pressure adjusting opening is adjusted by the operating portion in accordance with the change, so that the product opening and the amount of the viscous elastomer material delivered to the back pressure adjusting opening can be adjusted and distributed. It is characterized by. Wherein said back pressure adjusting hole may be provided away from the product opening to the base plate, also a viscous elastomeric material filling part provided on the extrusion immediately before by die extrusion, said charging
It may be provided on the extruder wall of the filling section . In particular, in the former case, a movable plate is separately provided on the front surface of the base plate so that the opening area of the back pressure adjusting opening can be adjusted, and the movable plate is slid by detection by the pressure sensor, and the product opening and the back are adjusted. It is necessary to distribute the pressure adjustment openings according to the pressure change. In this case, the movable plate may be integrally connected to the sliding member, or may be separately operated. The devices according to claims 2 to 4 relate to these configurations.

[0008]

The product opening and the back pressure adjusting opening are provided at the tip of the extruder as described above, and the back pressure corresponding to the change in the opening area of the product opening is detected, and based on this, the product opening is performed. In the method and apparatus according to the present invention in which the back pressure is distributed to the back pressure adjusting opening and the back pressure adjusting opening, the sliding member is manually or mechanically or electrically operated so as to change the sectional area of the product opening to a predetermined sectional shape. When moved to, the back pressure of the viscoelastic body that has been extruded by the screw in the extruder, that is, the viscous elastomer material changes,
This change in back pressure is detected by a pressure sensor installed in advance. The sensed change in back pressure is immediately sent to the control unit, and transmitted to the movable unit that changes the cross-sectional area of the back pressure adjusting opening independent of the control unit. In this case, when the product opening area moves in the decreasing direction due to the movable part, the back pressure in the extruder immediately before the extrusion of the product opening normally increases, and the extruded product increases in shape by the die well, and the shape increases. Although accuracy is lost, in the present invention, the opening area of the back pressure adjustment opening increases, an elastomer material corresponding to the shape change is delivered to the product opening, the discharge pressure is made uniform, and the fluctuation of the die well is eliminated. , To ensure the accuracy of the product shape.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 3 show an example of an apparatus for carrying out the method of the present invention, in particular, an extrusion die at the tip of an extruder, which is a main part of the apparatus. In the drawings, the die forms a weather strip having a predetermined sectional shape. A base plate (1) having product openings (1a) and (1b) having a predetermined cross-sectional area to be operated, and a sliding member (3) slidably disposed on the front side of the base plate (1) on the extrusion side. ), And a surface plate (4) is adhered to the surface thereof to be integrated. A movable plate (5) for adjusting the back pressure is slidably provided below and opposite to the sliding member (3).

The movable plate (5) is provided with an opening (6) for adjusting the back pressure in a part thereof, and in correspondence with the opening, a product opening (1) is formed in the base plate (1) in FIG. An aperture (2) for adjusting the back pressure is provided at a distance. Of course, as described above, the structure of the base is not necessarily composed of the base plate (1), the sliding member (3), the movable plate (5), and the surface plate (4). ) And the movable plate (5) may be continuous and integral, or the surface plate (4) may not be particularly adhered, and these can be appropriately modified.

In the base having the above-described structure, the pressure sensor (7) penetrates through the base (1) and faces the product opening (1a) of the base (1). The pressure sensor (7) is connected to the control device (8), and transmits the pressure change of the corresponding portion detected by the pressure sensor (7) to the control device (8), and the control device (8). ) Is connected and connected to the operation system of the movable plate (5), and slides the movable plate (5) via the movable plate operating portion (9) in accordance with the transmitted pressure change, thereby moving the movable plate (5). 3 (A), 3 (B), 3 (A) and 3 (B) show the relative positions of the back pressure adjusting openings (2) and (6) corresponding to each other on the base plate (1).
As shown in (C), the opening area can be increased or decreased by shifting. In the figure, reference numeral (10) denotes an operating portion of the sliding member (3), which may be artificial, mechanical,
It may be operated electrically. FIG. 4 shows a sliding member (3) used when the sealing lip of a weather strip product to be extruded is hollowed, and a bridge (11) for the core.
It is fixed with.

Thus, when manufacturing a weather strip for an automobile using the above-described base, the single extrusion of only one elastomer material is described in the above description to simplify the description. As is known, as shown in FIGS. 7 and 8, a solid elastomer material (rubber) (22) is delivered from one extruder (20), and a foamable elastomer material (rubber) is delivered from the other extruder (21).
(23) is sent out, the seal part (24) is molded from the foamable elastomer (23), and the mounting part (2
5) is molded by a solid elastomer (22).
However, the weather strip to be formed usually does not have the same width in the length direction as shown in FIG. 9, but changes in the middle while being continuously extruded.

Then, when the sliding member (3) is moved by the operating part (10) to adjust the sectional area of the product openings (1a) and (1b) to a predetermined sectional shape, it is pushed out from the extruder. The back pressure of the viscous elastomer material changes due to the change of the opening area, and the pressure sensor (7) detects this and moves the movable plate (5) via the control device (8).

At this time, the opening areas of the product openings (1a) and (1b) and the opening areas of the back pressure adjusting openings (2) and (6) are movable in directions inversely proportional to the quantity. When the product opening area is reduced due to the decrease in the width of the weatherstrip product, the back pressure adjustment opening area increases and the back pressure rise is reduced to make the discharge pressure to the product opening uniform. Thus, the variation of the die well can be eliminated, and the shape of the weather strip having the predetermined shape can be accurately formed.

FIGS. 10A, 10B and 10C show examples of the weather strip obtained by the method of the present invention as described above. In the above description, the movable plate (5) which responds to the pressure sensor (7) is provided, but the opening for back pressure adjustment may not be separately provided in the base plate (1) or the movable plate (5). . FIGS. 5 and 6 show an example thereof. A base plate (1), a sliding member (3) and a surface plate (4) are the same as those shown in FIGS. Instead, a valve-like opening / closing plate (14) is provided on a part of the peripheral wall (13) at the viscous elastomer material filling portion (12) immediately before extrusion at the mouth portion at the tip of the extruder, and a pressure sensor is provided. When the change in back pressure due to (7) is detected, the open / close plate (14)
Is actuated to the opening / closing adjustment side by the operating portion (15) to change the opening area of the back pressure adjusting opening (16). In this example as well, the product opening area changes and at the same time the independent back pressure adjustment opening area changes in inverse proportion to the quantity to make the discharge pressure uniform and ensure the accuracy of the product shape. This is the same as the embodiment. Further, it goes without saying that the present invention can be variously modified without departing from the purpose thereof.

[0016]

According to the present invention, when a weather strip having a width which varies in the length direction is manufactured as described above, the formed body is pressed through a product opening of an extrusion die at the tip of an extruder to change the width of the weather strip. In response to the above, the opening area of the product opening is adjusted by the sliding member, and the back pressure of the viscous elastomer material immediately before extrusion caused by the adjustment change of the opening area due to the sliding of the sliding member is detected. The back pressure is distributed to the product opening and the back pressure adjusting opening to adjust the rate of sending out the elastomer material to each opening, and is inversely proportional to the change in the product opening area. By adjusting the back pressure adjusting opening area, if the product opening becomes smaller in accordance with the screw diameter feed in a normal case, the extruded viscous material generates a large back pressure and the product opening Die swelling by the principle of streamline convergence , Which affects the cross-sectional area and adversely affects the product shape.However, due to the distribution to the two opening areas, the discharge pressure and the back pressure to the product opening are always controlled to be constant, and the delivery amount to the product opening is There is a remarkable effect that the accuracy of the product shape can be secured and improved without being appropriately controlled and the die well does not change. Moreover, according to the method of the present invention, there is no limitation on the shape of changing the product as in the conventional methods, and the shape of the tip seal portion in contact with the vehicle panel side is a thin lip, a bent lip, or a hollow lip. Also, the length of the part connected to the seal portion can be easily changed, and the applicable range is very wide. The invention according to claims 2 to 4 is extremely easy to manufacture and practical as an apparatus for performing the above method.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one example of an extruder head used for carrying out the method of the present invention.

FIG. 2 is a schematic perspective view of the extrusion die of FIG. 1;

FIGS. 3A and 3B are diagrams showing an adjustment state of each hole when a sliding member and a movable plate are moved, respectively. FIG.
(B) is a state in the intermediate state, and (C) is a state in the ascending state.

FIG. 4 is a perspective view showing a structural example of a sliding member when a tip seal lip of a product is hollow.

FIG. 5 is a sectional view of an extrusion head portion showing another embodiment of the apparatus of the present invention.

FIG. 6 is a schematic perspective view showing the extrusion die in FIG. 5;

FIG. 7 is a schematic diagram of an extruder.

FIG. 8 is an explanatory diagram showing a molding state when molding into two layers.

FIG. 9 is an explanatory view showing a changed state of a weather strip manufactured by the present invention.

FIG. 10 shows a weather strip manufactured by the present invention, wherein (A), (B) and (C) are representative examples.

[Explanation of symbols]

 (1) Base plate (1a) (1b) Product opening (2) Opening for back pressure adjustment of base plate (3) Sliding member (5) Movable plate (6) Opening for back pressure adjustment of movable plate ( 7) Pressure sensor (14) Opening / closing plate (16) Opening for back pressure adjustment

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kaizo Yoshioka 3rd, Ikoshiyama, Uchikoshi, Miyoshi-cho, Nishikamo-gun, Aichi Pref. Toyo Tire & Rubber Co., Ltd. JP, A) JP-A-63-98412 (JP, A) JP-A-59-165312 (JP, A) JP-A-63-246233 (JP, A) JP-A-59-114040 (JP, A) JP-A-59-160677 (JP, A) JP-A-59-171735 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96

Claims (4)

(57) [Claims] In a method for manufacturing a weather strip whose width changes in the length direction, a molded body is extruded through a product opening of an extrusion die at an end of an extruder, and sliding is performed in accordance with the width change of the weather strip. The moving member detects the back pressure of the viscous elastomer material immediately before extrusion caused by the opening of the product, and applies the back pressure to the opening of the product and the change in the area of the opening simultaneously.
A method for producing a weather strip, comprising: distributing the elastomer material to the back pressure adjusting openings whose areas change in inverse proportion to the amount in conjunction with the opening to adjust the rate of sending out the elastomer material to each opening. 2. An apparatus for manufacturing a weather strip whose width changes in the length direction, wherein an extrusion die attached to an extruder tip separates a product opening and a back pressure adjusting opening from each other. A base member, a sliding member slidably provided so that the opening area of the product opening can be adjusted on the front surface of the base plate, and a back pressure adjusting opening front surface of the base plate. The opening area of the opening is simultaneously linked to a change in the area of the product opening.
And a movable plate provided so as to be adjustable by changing the area in inverse proportion to the quantity, and a pressure sensor is attached to the base plate facing the opening, and the pressure sensor is connected to the control device. when you detect a change in pressure, the pressure change control Te
Control device, and the control device transmits the transmitted pressure.
The movable plate is slid via the movable plate operating portion in accordance with the force change, so that the positional relationship between the base plate and the movable plate and the corresponding back pressure adjusting openings can be shifted to adjust the opening area. An apparatus for manufacturing a weather strip. 3. A sliding member and a movable plate are integrally connected.
3. The apparatus for manufacturing a weather strip according to claim 2, wherein the apparatus slides integrally. 4. An apparatus for manufacturing a weather strip whose width changes in the length direction, wherein an extrusion die attached to a tip of an extruder has a die plate having a product opening, and a front surface of the die plate. It comprises a sliding member slidably provided so that the opening area of the product opening can be adjusted, and a viscous elastomer filled portion of the extruder is formed immediately before the extrusion die. Filling
Area products opening the open area of the opening portion in a part of the peripheral wall of Hama portion
The area change is in inverse proportion to the quantity in conjunction with the change at the same time.
Allowed adjustably becomes closing plate with the back pressure adjusting hole is provided, said ferrule plate is attached a pressure sensor further facing opening, the pressure sensor is connected to the controller detects a pressure change The opening and closing by the operating part according to the change
An apparatus for manufacturing a weatherstrip, wherein the apparatus is configured so that the opening area of the back pressure adjusting opening can be adjusted by operating a plate .