JPH11156911A - Manufacture of weatherstrip of belt line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute miniaturization of a cooling device, increase of an extrusion speed, avoiding generation of warpage with time, or the like by a method wherein a part facing a hollow part is cooled to the same degree as that for a surface of a weatherstrip. SOLUTION: A first part 9 coextruded from a die 1 is introduced in a water bath tank 11 to be cooled. Cooling water 11a stored in the water bath tank 11 becomes an outer surface of a weatherstrip. It is not only cooled by coming in an contact with a part of a first part 9, but also it enters into a part to become a hollow part from a gap, and cools directly a part to be a fin part and a fitting part from inside. Therefore, both of an inside and outside of the fin part having the hollow part are also cooled in the same way. The weatherstrip under a state of being continued longitudinally is sent into a cutting machine 23 via a taking off device 19, and becomes the weatherstrip 23 cut at specific intervals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a weather strip for a belt line, and more particularly to a method of manufacturing a resin weather strip having a hollow portion therein.

[0002]

2. Description of the Related Art A weatherstrip is mounted on a doorway of a doorglass in order to prevent the intrusion of rainwater and dust by slidingly contacting the doorglass and to reduce wind noise. The weatherstrip has a mounting portion to be mounted on the door trim or the door panel, and a fin portion formed so as to extend from the mounting portion toward the door glass and a part of which is in sliding contact with the door glass. The production of weather strips is performed by various methods, but is often performed by an extrusion molding method because of high productivity and ease of production. On the other hand, in order to improve the strength, reduce the weight, and impart flexibility of the weather strip, a weather strip structure having a hollow portion inside may be adopted.

[0003]

However, when a weatherstrip having a hollow portion therein is manufactured by an extrusion method, a surface of the extruded material (hereinafter referred to as "extruded material") is formed inside the hollow portion. The cooled part is harder to cool than other parts. That is, since the cooling after extrusion is performed by bringing a cooling medium such as water or air into direct contact with the extrudate, the cooling medium is in direct contact with the cooling medium as compared with the surface of the weather strip cooled by direct contact with the cooling medium. No, the part facing the hollow part is difficult to cool. Furthermore, since the hollow portion holds heated air heated during extrusion molding, the portion facing the hollow portion exposed to the heated air is extremely unlikely to be cooled. For this reason, so that the part facing the hollow part can be sufficiently cooled,
It was necessary to increase the performance of the cooling device and to reduce the extrusion speed. Furthermore, since the cooling rates of the surface of the weatherstrip and the portion facing the hollow portion are remarkably different, it has been observed that the residual thermal stress and the like of the two are different, and that the manufactured weatherstrip is warped with time.

Therefore, in the weather strip of the present invention, the portion facing the hollow portion can be cooled to the same degree as the surface of the weather strip,
It is an object of the present invention to provide a method of manufacturing a weatherstrip that enables a cooling device to be miniaturized, an extrusion speed to be increased, and generation of warpage with time to be avoided.

[0005]

According to the present invention, there is provided a method for manufacturing a weather strip, comprising: extruding a weather strip having a shape in which a wall of a weather strip surrounding a hollow portion is cut off along a longitudinal direction of the weather strip. Cooling the cut and joining the separated walls. In this way, when cooled, the part that is to become a hollow part is open to the outside and can directly contact the cooling medium, so that the part facing the hollow part is comparable to the surface of the weather strip. Can be cooled. That is, the present invention is a method for manufacturing a resin weatherstrip of a belt line, which is mounted on a doorway of a door glass of an automobile door and has a hollow portion inside the weatherstrip, and surrounds the hollow portion. A first strip having a shape in which a wall of the weatherstrip is continuously cut in a direction parallel to a longitudinal direction of the weatherstrip so that a portion to be the hollow portion is opened to the outside of the weatherstrip; Forming the portion by extrusion, cooling the first portion, and joining the separated walls of the first portion to form the closed hollow portion. Is the way.

The present method is a method for manufacturing a resin weather strip which is a resin weather strip of a belt line attached to an elevator of a door glass of an automobile door and has a hollow portion inside the weather strip. Weather strips to which the present method can be applied include both so-called inner weather strips mounted on the vehicle interior and so-called outer weather strips mounted on the vehicle exterior. In addition, "made of resin" here
It suffices that the weather strip wall surrounding the hollow portion is formed of at least a resin, and the entire weather strip is not necessarily formed of a resin. The weatherstrip to which the method is applied has a hollow portion therein. The hollow portion may have any shape, but considering that the weatherstrip is formed by extrusion, the cross-sectional shape when cut in a direction perpendicular to the longitudinal direction of the weatherstrip is unchanged. It is preferably a hollow part. The portion of the weatherstrip where the hollow portion is formed may be any portion that needs to improve strength, reduce weight, and impart flexibility. In particular, the fin portion formed so as to extend in the direction of the door glass from the mounting portion for attaching the weather strip to the door panel,
It is preferable to form a hollow portion in the fin because it requires flexibility and strength to adhere to the door glass.

[0007] The first step of the method comprises the steps of enclosing the wall of the weatherstrip surrounding the hollow portion such that the portion to be hollowed out is opened to the outside of the weatherstrip.
A first portion having a shape continuously separated in a direction parallel to the longitudinal direction of the weather strip is formed by an extrusion molding method. That is, in the first portion, the portion to be the hollow portion is opened to the outside of the weather strip and communicates with the wall surrounding the hollow portion being cut off. For this reason, the wall surrounding the hollow portion of the extruded first portion can be effectively cooled by coming into direct contact with a cooling medium such as water. In the first part, the wall surrounding the hollow part is cut off continuously in a direction parallel to the longitudinal direction of the weatherstrip. Since the wall is “separated continuously in a direction parallel to the longitudinal direction”, the shape of the cut surface by a plane perpendicular to the longitudinal direction is constant. Also,
At the part where the wall is cut off, the part to be a hollow part communicates with the outside of the weather strip. In the plane cut in the direction perpendicular to the longitudinal direction, it is preferable that both sides of the separated part have a certain distance or more, so that the cooling medium easily enters the part to be a hollow part. That part can be cooled effectively. In this case, the shape of the wall surrounding the hollow part is different between the first part and the finished weatherstrip (a difference occurs because the expanded cut-off is closed in the finished product). If the material forming the wall is flexible, the weather strip can be completed without any problem.

[0008] The extrusion of the first portion may be performed by any known extrusion method, and the extrusion conditions can be appropriately determined according to the material to be used and the shape of the first portion.

The first portion may be formed at both sides of the separated wall with portions which can be fitted to each other. By doing so, the step of joining the separated walls (third step) can be easily performed. That is, it is used to join the two side portions only by fitting, used as a fixing means until the adhesive is solidified when bonding with an adhesive, and used to facilitate positioning of the joint. can do.

[0010] The second step of the method is to cool the extruded first part. Cooling is performed by bringing the cooling medium into direct contact with the first part. At this time, since the wall surrounding the hollow part is cut off, the cooling medium can easily enter the part to be the hollow part, and the surface in contact with the part to be the hollow part can be directly cooled. it can. Any cooling medium may be used. For example, gases such as air and nitrogen gas, and liquids such as water and organic solvents can be used. Particularly, economical efficiency, high cooling efficiency, non-toxicity, and the like can be used. Considering the above, it is preferable to use water. When water is used as the cooling medium, it is preferable to allow the first portion to pass through the water bath because the first portion can be cooled reliably and easily.

The third step of the method joins the separated walls of the first part to form a closed hollow part. So that the cooling medium can penetrate into the hollow part
Joining cut-off portions formed in the wall surrounding the hollow portion. The joining may be performed by any method, for example, by bonding using an adhesive, fitting, fusion, and attachment with tacks or the like. Among them, heat fusion and ultrasonic fusion are preferred because they can be quickly and firmly fused, and fitting is preferred because they can be easily joined. When this bonding is performed by adhesion or fusion, both sides of the separated wall are preferably formed of the same material for easy and strong bonding. The joining closes the hollow portion and forms a separate hollow portion (excluding the opening of the hollow portion at the end of the weatherstrip). Prior to the third step, a step of removing the cooling medium adhered to the weather strip (including a part to be a hollow part) may be provided. Further, the weather strip may be provided before or after the third step. A step of cutting in a direction perpendicular to the longitudinal direction may be provided.

A portion of the weatherstrip (fin) that slides on the door glass (hereinafter referred to as a "sliding portion").
Requires slidability to ensure that the door glass moves up and down smoothly. For this reason, the sliding portion is usually provided with flocking or the like, thereby imparting slidability. Therefore,
The sliding part is often difficult to extrude together with the first part, in which case, separately from the extrusion of the first part, to the molded first part What is necessary is just to form a sliding part. The method for separately forming the sliding portion may be any method, and may be formed at any process stage.

[0013] In order to impart slidability to the sliding portion, the sliding portion may be formed of a resin material layer having self-slidability. Since the resin material layer having self-slidability can be formed by an extrusion molding method, in this case, the resin material layer can be extrusion-molded together with the first portion, and the manufacturing process of the weather strip can be greatly reduced. Can be simplified. As a resin material having a self-sliding property (hereinafter, referred to as “sliding material”), ethylene tetrafluoride (hereinafter, “PTF”) is used.
E ". ), Etc., which have self-sliding properties, or those which do not have self-sliding properties, such as polypropylene, are added with a substance which imparts self-sliding properties, such as PTFE. It can be any of those. However, when it is necessary to obtain several different levels of slidability when forming different weather strips or the like, a material that imparts self-slidability (hereinafter referred to as “slidability additive”) ) Is preferably used. In this way, a desired level of slidability can be freely obtained by changing the amount of the slidability additive. That is, in this case, the sliding material may be a second resin material obtained by mixing the first resin material and the slidability additive. When the first resin material is added with a slidability additive to form a second resin material, the second resin material is
Any material may be used as long as it has sufficient properties to form the sliding surface. For example, polyethylene, polypropylene, polyvinyl chloride, TPO and the like can be used. In particular, it is desirable to use TPO as the first resin material in consideration of the slidability and strength of the second resin material. Here "TP
"O" means a thermoplastic olefin (base resin is CnH2n), which is a kind of thermoplastic elastomer.

As the slidability additive, any existing one can be used as long as it is well dispersed in the resin to which the slidability additive is added and can stably maintain the slidability. Good examples include, for example, ethylene tetrafluoride resin, polysiloxane, carbon fiber, graphite, and the like. However, it is not preferable that the slidability additive adheres to the surface of the door glass when the door glass slides on the sliding surface, and the visibility through the door glass deteriorates. The slidability additive has a particle size of 2 to 4
It is preferable to use one having a thickness of μm, and the amount of the slidability additive is preferably about 5 to 20% by weight based on the first resin.

The sliding portion formed by the sliding material is:
The weather strip may have any shape as long as it can sufficiently fulfill the functions of preventing rainwater and dust from infiltrating and soundproofing, and may be constituted by a smooth surface without irregularities. However, depending on the slidability of the sliding part, if the contact area between the sliding part and the door glass is large, the frictional force at the time of lifting and lowering the door glass increases, and the force required for raising and lowering the door glass and the driving power increase. There is. To solve this problem, irregularities may be formed on the sliding portion to reduce the contact area. The shape and number of the concavities and convexities can be appropriately determined according to a desired amount or the like for reducing the contact area. As the irregularities which can be easily formed and have an excellent appearance, a groove or a linear convex portion formed in a sliding portion can be exemplified. If the depth of the groove or the height of the linear convex portion is too large, there is a problem that a large gap is generated between the weather strip and the door glass. Is preferable. The irregularities may be irregularly formed, but it is preferable that the irregularities are formed in a direction perpendicular or parallel to the longitudinal direction of the weather strip. When the door glass is moved up and down, a horizontal force is applied to the ground in a direction parallel to the main surface of the door glass (that is, when the door glass is moved up and down with the door closed), the force is applied in the front-rear direction of the vehicle. May hinder smooth lifting of the door glass. Usually, since the door glass is often raised and lowered in a direction perpendicular to the longitudinal direction of the weather strip, the force increases as the angle formed by the direction in which the unevenness is formed with respect to the vertical direction approaches 45 degrees. . Therefore, in order to smoothly raise and lower the door glass, it is better that the angle is close to 0 degrees or 90 degrees, so that the unevenness is formed in a direction perpendicular or parallel to the longitudinal direction of the weather strip. Is preferred. Note that the “formation of unevenness” here includes all cases of forming only a concave portion in a sliding portion, forming only a convex portion, and forming both a concave portion and a convex portion. .

The material for forming the weatherstrip may be any material, but it is preferable that the mounting portion has sufficient rigidity because it is a portion for firmly mounting the weatherstrip. It is preferable that the mounting portion is formed of a hard resin, and the fin portion is formed of a soft resin, since it is preferable to flexibly deform according to the surface shape of the fin. As the hard resin, any resin material may be used as long as the weather strip can be attached with sufficient rigidity, such as polyethylene, polypropylene, polyamide, polycarbonate, polyester, polyacetal, hard polyvinyl chloride, and these. To which an additive such as glass fiber is added. In particular, it is preferable to use polypropylene in consideration of material costs, physical properties, recyclability, environmental friendliness, and the like.
As the soft resin, any resin material may be used as long as it has a certain degree of flexibility and can be deformed according to the shape of the surface of the door glass. For example, polyurethane, soft polyvinyl chloride, TPO or the like is used. can do. In particular, TPO is excellent in durability, recyclability and environmental properties, and is desirably used as a soft resin.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings based on embodiments, but the present invention is not limited thereto.

FIG. 1 is a process explanatory view for carrying out a method according to an embodiment of the present invention. Referring to FIG. 1, extruders 2, 3 and 4 are connected by a die 1. Extruder 2 feeds polypropylene to die 1, extruder 3 feeds soft resin TPO to die 1, and extruder 4 feeds sliding material, a mixture of TPO and PTFE, to die 1. I do. The polypropylene from extruder 2 forms a mounting part, the TPO from extruder 3 forms a fin, and the mixture of TPO and PTFE from extruder 4 forms a sliding part. Each of the three types of molten resin forms a first portion 9 continuously by being co-extruded from a portion of the die 1 corresponding to a portion to be formed in the die 1.

FIG. 2 is a sectional view showing a cross-sectional shape of the first portion 9 co-extruded from the die 1 (a cross-sectional shape cut in a direction perpendicular to the longitudinal direction of the first portion 9). FIG.
Referring to, the first portion 9 includes a mounting portion 52 that is mounted on a door panel or the like, and a fin portion 54 that extends from the mounting portion 52 toward the door glass.
And a sliding portion 56 is formed on the outer surface of the fin portion 54. Sliding part 56 of this embodiment
Although no irregularities are formed on the sliding portion 56, irregularities may be formed on the sliding portion 56 so as to reduce the contact area between the door glass and the sliding portion 56 in order to smoothly move the door glass up and down. . The projections and depressions are formed, for example, by forming a shape corresponding to the projections and depressions on a portion of the extrusion die corresponding to a portion where the projections and depressions of the sliding portion 56 are to be formed, or by forming the first portion 9 immediately after the extrusion. It can be performed, for example, by pressing an object having such a shape as to form irregularities. A portion 58 to be a hollow portion is formed by a fin portion 54 and a mounting portion 52. The portion 58 to be a hollow portion is located outside the first portion 9.
A part of the wall surrounding the hollow portion is cut off so as to be opened to form a gap 62. The first part 9 has the same cross-sectional shape as shown in FIG. 2 in all parts along its longitudinal direction. Portions 64a and 64b are formed on both sides of the separated wall so that both sides can be fitted with each other. Also,
Both sides of the separated wall are made of polypropylene.

Referring again to FIG. 1, the first portion 9 co-extruded from the die 1 is introduced into a water bath (cooling bath) 11 to be sunk into water and cooled. Water bath (cooling bath) 1
The cooling water 11a stored in 1 is not only brought into contact with the portion of the first portion 9 serving as the outer surface of the weather strip and cooled, but also from the gap 62 shown in FIG. To cool the fin portion 54 and the mounting portion 52 directly from the inside. Therefore, both the inside and the outside of the fin portion having the hollow portion are similarly cooled, and the entire first portion 9 can be cooled substantially uniformly and quickly. First part 9 of water bath (cooling bath) 11
The cooling conditions such as the length of the water passing through, the water temperature of the cooling water 11a, and the moving speed of the first portion 9 may be appropriately determined as in the related art.

The first portion 9 taken out of the water bath (cooling bath) 11 is blown off by a wind generated by a blower 13 in order to remove the water adhering thereto. In addition to blowing off the water, a slightly heated and dried air may be sent to dry the water attached to the first portion 9.

The first portion 9 from which the moisture has been removed is introduced into an ultrasonic welding device 15 for joining the separated walls. In the ultrasonic fusion device 15, the portions 64a and 64b that can be fitted to each other are fitted and fused, and the gap 62 is closed. Since the fin portion 54 is formed of TPO, which is a soft resin, the portions 64a and 64b that can be fitted to each other can be easily fitted. By joining the walls, a closed hollow part is formed. FIG. 3 shows a cross-sectional shape of the ultrasonically fused weather strip 17 in a state continuous in the longitudinal direction.
Shown in Compared with the cross-sectional shape of the first portion 9 shown in FIG. 2, the portions 64a and 64b that can be fitted to each other are fused to form the fin portion 70. The fin portion 70 and a part of the attachment portion 52 form a hollow portion 72 having a substantially triangular cross-sectional shape.

Referring to FIG. 1 again, the weather strip 17 which is continuous in the longitudinal direction is sent to the cutting machine 21 via the take-off machine 19 and the weather strip 23 which has been cut at regular intervals. Become. Thereafter, the weather strip is completed through a finishing step, an inspection step, and the like.

It is needless to say that the present invention is not limited to the above-described embodiment, and further includes a range substantially equivalent to the scope of the claims.

[0025]

Since the present invention is configured as described above, it has the following effects. In other words, the manufacturing method of the present invention is arranged so that the wall of the weatherstrip surrounding the hollow portion is parallel to the longitudinal direction of the weatherstrip so that the portion to be the hollow portion is opened to the outside of the weatherstrip. Forming a first part having a shape continuously separated by extrusion molding method,
Cooling the first portion and joining the separated walls of the first portion to form a closed hollow portion, thereby providing a cooling medium to the inner surface portion of the wall surrounding the hollow portion. The direct contact makes it possible to effectively cool the inner surface portion, thereby making it possible to reduce the size of the cooling device, increase the extrusion speed, and avoid warpage over time. Furthermore, if the sliding part is made of a sliding material,
The sliding part can be formed integrally with other parts, and the number of steps and cost of the manufacturing process can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a process explanatory view for carrying out a method according to an embodiment of the present invention.

FIG. 2 is a sectional view of a first part.

FIG. 3 is a cross-sectional view of the weatherstrip with the separated walls joined together.

[Explanation of symbols]

Reference Signs List 1 die 2 extruder (polypropylene) 3 extruder (TPO) 4 extruder (mixture of TPO and PTFE) 9 first part 11 water bath (cooling bath) 11a cooling water 13 blower 15 ultrasonic fusion device 17 longitudinal Weather strip 19 in a continuous state in the direction 19 take-up machine 21 cutting machine 23 cut weather strip 52 mounting part 54 fin part 56 sliding part 58 part to be hollow part 60 outside of first part 62 gap 64a , 64b Part that can be fitted to each other 70 Fin part 72 Hollow part

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Claims (9)

[Claims] 1. A method of manufacturing a resin weatherstrip for a belt line, which is mounted on a doorway of a door glass of an automobile door and has a hollow portion inside the weatherstrip, surrounding the hollow portion. The weatherstrip wall,
A first portion having a shape continuously cut in a direction parallel to the longitudinal direction of the weather strip is extruded by an extrusion molding method so that the portion to be the hollow portion is opened to the outside of the weather strip. Forming, cooling the first portion, and joining the separated walls of the first portion to form the closed hollow portion. 2. The resin weather according to claim 1, wherein the hollow portion is formed in a fin portion formed so as to extend in a direction of a door glass from a mounting portion for attaching the weather strip to a door panel. Strip manufacturing method. 3. The production of a resin weather strip according to claim 1 or 2, wherein a portion at which the both sides can be fitted to each other is formed at both sides of the separated wall. Method. 4. The method for manufacturing a resin weather strip according to claim 1, wherein both side portions of said cut-off wall are formed of the same material. 5. The method according to claim 1, wherein the joining of the separated walls of the first part is performed by any one of heat fusion, fitting, and ultrasonic fusion. 3. The method for producing a resin weather strip according to item 1. 6. The method for producing a resin weather strip according to claim 1, wherein the cooling of the first portion is performed by bringing water into contact with the first portion. . 7. The weather strip according to claim 1, wherein a portion sliding on the door glass is not included in the first portion, and the sliding portion is formed separately on the first portion. 7. The method for producing a resin weatherstrip according to any one of claims 1 to 6. 8. The weather strip, wherein a portion that slides on the door glass is formed of a resin material layer having self-slidability, and the resin material layer is included in the first portion. Item 7. The method for producing a resin weather strip according to any one of Items 1 to 6. 9. The method for producing a resin weather strip according to claim 8, wherein irregularities are formed in said sliding portion.