JP2020045095A - Weather Strip - Google Patents

Abstract

To provide a long weather strip in which wall thickness of a hollow seal part is partially changed, and a manufacturing method for the weather strip on the basis of extrusion molding.SOLUTION: An extrusion mold includes: a mouthpiece 40 and a core 50. The core 50 has a moving core part 51 movable in a direction of extrusion; and a fixing core part 52. In the moving core part 51, a cross sectional shape is a non-similar shape in front and rear two places (51a and 51b) in the direction of extrusion. In a state of arranging the moving core part 51 in an advance position (first position), a first part (6A) of a long weather strip is molded, and in a state of arranging the moving core part 51 in a retreat position (second position), a second part (6B) of the long weather strip is molded. At the time of molding the second part (6B), a supply amount per unit time of seal portion material to a molding space 42 of a hollow seal portion secured between the core and the mouthpiece is increased compared with that at the time of molding the first part (6A).SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method for manufacturing a weatherstrip, and more particularly to a method for extruding a weatherstrip using a special extrusion mold. The present invention also relates to a weather strip having a hollow seal portion.

  Generally, a vehicle has a peripheral portion of an opening of a vehicle body (for example, a back door opening, a trunk opening, a front door opening, a rear door opening, etc.) and a door body (for example, a back door, A weatherstrip is provided for sealing the periphery of the trunk lid, the front door, the rear door, and the like) from the weather and dust. The periphery of the vehicle body opening is bordered by a combination of sides that extend substantially straight and curved corners that connect the sides. In many cases, the weather strip has a length corresponding to the peripheral edge of the vehicle body opening and is mounted along the opening edge. Therefore, it is necessary to mount the weather strip at the corner while bending the weather strip. However, when the weatherstrip is curved corresponding to the corner, the hollow sealing portion of the weatherstrip may be unnaturally crushed and partially impair the sealing performance. In order to prevent such a hollow seal portion from being unnaturally crushed, a portion of the hollow seal portion to be attached to a corner portion has a wall thickness larger than that of a portion to be attached to a side portion. May be adopted.

  Patent Literature 1 (Japanese Patent Application Laid-Open No. 63-13022) discloses a weatherstrip for an automobile that embodies the above-described design concept, and a method and an apparatus for manufacturing the same. That is, in the weather strip according to the example of the document 1, the sealing portion 13 of the weather strip A corresponding to the straight portion of the trunk lid has a perfect circular shape (FIG. 4), while the sealing portion 13 is formed at the convex corner of the trunk lid. In the corresponding sealing portion 13a of the weather strip B, only the side portion S is thick (FIG. 5). In order to manufacture a weather strip in which the thickness of the seal portion is partially changed, the extrusion molding apparatus disclosed in Patent Document 1 uses a plurality of dies 2, 3 for a hollow seal portion having different discharge port diameters. 4 are sequentially arranged in front of the die 1 for the attachment portion (trim portion) of the weather strip (FIG. 1), and for example, the die 2 for the seal portion 13a is installed at a position corresponding to the side portion S. The sponge rubber material pushing means 6 is connected to the connection structure 10 (FIG. 2). Then, at the timing of the extrusion molding of the weather strip B corresponding to the convex corner portion, the screw rotation of the sponge rubber material extrusion means 6 is increased to supply a large amount of rubber to the connection structure 10 with the die 2, whereby the sealing portion 13 a (See the upper left column on page 3 of the same document 1).

JP-A-63-13022

  In Patent Literature 1, in order to selectively increase the thickness of the side cross section S of the annular cross section of the seal portion 13a of the weather strip B, at a predetermined extrusion molding timing, the amount is larger than that in the normal extrusion molding. Is supplied to the connection structure 10 with the die 2 (additional supply or excessive supply). For this reason, even in the annular cross section of the seal portion 13a, the extrusion amount per unit area of the rubber material at the side portion S (hereinafter, simply referred to as “extrusion amount”) is the extrusion amount of the rubber material at portions other than the side portion S. And the amount of extrusion tends to be uneven in the circumferential direction of the seal portion 13a. Then, the side portion S having a relatively large amount of extrusion has to keep pace with a portion other than the side portion S having a relatively small amount of extrusion, and as a result, the side portion S of the seal portion 13a has a pushing direction ( In other words, it is formed in a wavy shape along the longitudinal direction of the weatherstrip), and the appearance is deteriorated.

  An object of the present invention is to provide a method for manufacturing a weatherstrip that can extrude a weatherstrip while changing the wall thickness of the hollow seal portion without deteriorating the appearance of the hollow seal portion. . Another object of the present invention is to provide a weatherstrip having a hollow seal portion having a partially different wall thickness.

An invention according to claim 1 is an extrusion molding method using an extrusion mold to form a long weatherstrip for sealing between a vehicle body opening bordered by a peripheral edge and a door body capable of closing the vehicle body opening. The method of manufacturing,
The long weather strip has at least a first portion and a second portion in a longitudinal direction, and has a hollow seal portion that can abut on a peripheral portion of the door body or the vehicle body opening, Regarding the wall thickness of at least a part of the hollow seal portion, the wall thickness of the hollow seal portion in the second portion is larger than the wall thickness of the hollow seal portion in the first portion,
The extrusion mold includes at least a die for molding the outer shape of the hollow seal portion, and a core for molding the inner shape of the hollow seal portion,
The core has a movable core portion movable along the extrusion direction with respect to the die,
The movable core portion has at least two positions, a first position for forming the first portion of the weatherstrip and a second position for forming the second portion of the weatherstrip. Can be placed in
Regarding the cross-sectional shape of the core at the exit position of the base, the cross-sectional shape of the core when the movable core is disposed at the first position, and the movable core is disposed at the second position. The core is formed so that the cross-sectional shape of the core when the core is not similar to the shape of the core,
Regarding the sectional area of the molding space for the hollow seal portion secured between the core and the die at the die exit position, the cutting of the molding space when the movable core is disposed at the first position. The core is formed such that the cross-sectional area of the molding space when the movable core is disposed at the second position is larger than the area,
The method is
A) a step of molding the first portion of the weatherstrip with the movable core located at the first position;
B) forming the second portion of the weatherstrip with the movable core located at the second position;
In the step B), the supply amount of the sealing portion material per unit time to the molding space secured between the core and the die is set to be smaller than the supply amount in the step A). increase,
A method for producing a weatherstrip.

  According to the first aspect of the present invention, in the step (B) of forming the second portion of the weather strip by disposing the movable core portion at the second position, the weather strip is disposed by disposing the movable core portion at the first position. As compared with the step (A) of molding the first part, the cross-sectional area of the molding space for the hollow seal portion secured between the core and the die at the exit position of the die increases, and The supply amount of the material for the seal portion per unit time increases. For this reason, in any part of the molding space, the supply amount per unit area (unit cross-sectional area) of the seal portion material can be made constant (uniform). As a result, it is possible to prevent the hollow seal portion from waving, and to extrude the weather strip while changing the wall thickness of the hollow seal portion without deteriorating the appearance of the hollow seal portion.

According to a second aspect of the present invention, in the method for manufacturing a weather strip according to the first aspect,
The long weather strip further includes a mounting portion adjacent to the hollow seal portion in a cross section thereof,
The core is composed of the movable core, and a fixed core for movably supporting the movable core along the extrusion direction,
The fixed core portion is extended along the extrusion direction in a state of being integrated with the die, and a molding space for a hollow seal portion secured between the core and the die, It is arranged at the boundary with the molding space for the mounting part secured in the base.

  According to the second aspect of the invention, the following effect can be further obtained in addition to the effect of the first aspect of the invention. That is, the fixed core portion serves as a support member for supporting the movable core portion movably along the extrusion direction. In addition, the fixed core located at the boundary between the molding space for the hollow seal portion and the molding space for the mounting portion is such that the material for the hollow seal portion and the material for the mounting portion are randomly mixed. It functions as a partition member for preventing the occurrence of weather strip, and enables the production of a weather strip made of two kinds of dissimilar materials.

According to a third aspect of the present invention, in the method for manufacturing a weather strip according to the first or second aspect,
The movable core has a cross-sectional shape at the mouth exit position of the movable core located at the first position and a cross-sectional shape at the mouth exit position of the movable core located at the second position. Similar, and so that the cross-sectional area of the movable core portion located at the first position at the die exit position is larger than the cross-sectional area of the movable core portion located at the second position at the die exit position. The cross-sectional shape is different at at least two places along the extrusion direction.

  According to the third aspect of the invention, the following effects can be further obtained in addition to the effects of the first and second aspects of the invention. That is, since the movable core portion is formed so as to have a non-similar irregular cross section at at least two points along the extrusion direction as described above, the movable core portion is formed to form the second portion of the weather strip. The cross-sectional area of the molding space for the hollow seal portion at the mouth outlet position when the portion is disposed at the second position can be made relatively larger than when the movable core portion is disposed at the first position. .

According to a fourth aspect of the present invention, in the method for manufacturing a weather strip according to the third aspect,
The cross-sectional shape of the movable core located at the second position at the die outlet position corresponds to a shape in which the cross-sectional shape of the movable core located at the first position at the die exit position is partially cut away. To be characterized.

  According to the invention of claim 4, the following effect can be further obtained in addition to the effect of the invention of claim 3. That is, by using the movable core portion as described in claim 4, the cross-sectional shape of the hollow seal portion in the second portion of the weatherstrip is partially compared to the hollow seal portion of the first portion. It becomes possible to extrude the weatherstrip so that it is relatively thick.

The invention according to claim 5 is a long weather strip that seals between a vehicle body opening edged by a peripheral edge portion and a door body capable of closing the vehicle body opening portion,
The weatherstrip has at least a first portion and a second portion in a longitudinal direction thereof, and has a hollow seal portion capable of abutting on a peripheral portion of the door body or the vehicle body opening, and a hollow seal portion. It has an adjacent mounting part,
In a cross section of the hollow seal portion, the hollow seal portion can be divided into a root portion adjacent to the mounting portion and a head portion that is a remaining portion other than the root portion,
The first portion and the second portion have substantially equal wall thicknesses at the root side portion, and
The wall thickness of the head-side part in the second part is thicker than the wall thickness of the head-side part in the first part,
An outer shape of the hollow seal portion in a cross section is a weather strip in which the outer circumference of the second portion is larger than the outer circumference of the first portion.

According to the fifth aspect of the present invention, when the weather strip is attached to the vehicle body, the first portion is disposed mainly on the side of the peripheral edge of the vehicle body opening, and the second portion is disposed on the peripheral edge of the vehicle body opening. Are mainly arranged at the corners. At this time, since the wall thickness of the root-side portion of the hollow seal portion is substantially equal in the first portion and the second portion, the hollow seal portion of the second portion can easily follow the curved shape of the corner portion while being smoothly. It becomes possible to bend. On the other hand, since the wall thickness of the head side portion of the hollow seal portion is relatively thicker in the second portion than in the first portion, and the rigidity of the hollow seal portion in the second portion is high, the second portion is bent. However, it is possible to prevent the hollow seal portion from being unnaturally crushed or wrinkles from being generated in the hollow seal portion as much as possible.
Furthermore, since the circumference of the outer shape in the cross section of the hollow seal portion is relatively larger in the second portion than in the first portion, the second portion is curved and the hollow seal portion of the second portion is bent. Even if the upper end is slightly lowered, the height of the first portion and the second portion after the weather strip is completely attached to the vehicle body can be maintained at the same level, and the height of the sealing surface can be equalized.

  ADVANTAGE OF THE INVENTION According to the manufacturing method of the weatherstrip of this invention, it becomes possible to extrude a weatherstrip, without changing the external appearance of a hollow sealing part, and changing the wall thickness of a hollow sealing part. In addition, according to the weather strip of the present invention, the provision of the hollow seal portion having a partially different wall thickness allows the weather strip to be easily attached to the vehicle body and to be easily sealed after being attached. .

The outline | summary of the back door opening part of a passenger vehicle is shown, (A) is a perspective view in the mounted state of the weather strip according to 1st Embodiment, (B) is a perspective view in the non-mounted state of a weather strip. FIG. 2 is a cross-sectional view of the weather strip taken along a line II-II in FIG. 1. FIG. 3 is a cross-sectional view of the weather strip taken along a line III-III in FIG. 1. FIG. 2 is a plan view schematically illustrating a production line of an extrusion production facility. The front view which looked at the head for extrusion molding from the front side (downstream side of the production line). FIG. 3 is an enlarged front view of an annular molding space for a seal portion and its vicinity. FIG. 6 is a vertical cross-sectional view of the extrusion-forming head when the movable core portion advances (corresponding to a cross section taken along line YY in FIG. 5). FIG. 6 is a vertical cross-sectional view of the extrusion head when the movable core portion is retracted (corresponding to a cross section taken along line YY in FIG. 5). FIG. 1 is a schematic front view showing a semi-finished product and a finished product of a weather strip. FIG. 9 shows a modification of the first embodiment, and is a cross-sectional view of the weather strip at a position XX in FIG. 1. The modification of 1st Embodiment is shown, (A) is an enlarged front view of the annular shaping | molding space for seal parts, and its vicinity, (B) is a top view near the front-end | tip part of a movable core part. Sectional drawing of a weather strip which shows another modification of 1st Embodiment. The outline | summary of the back door opening part of a passenger vehicle is shown, (A) is a perspective view in the mounted state of the weather strip according to 2nd Embodiment, (B) is a perspective view in the non-mounted state of a weather strip. FIG. 14 is a cross-sectional view of the weather strip at the position of line PP in FIG. 13. FIG. 14 is a cross-sectional view of the weather strip taken along the line QQ in FIG. 13. The front view which looked at the extrusion head in 2nd Embodiment from the front side (downstream side of the production line). FIG. 10 is an enlarged front view of an annular molding space for a seal portion and its vicinity in the second embodiment. (A) and (B) are schematic sectional drawings in the RR line position of FIG.

  Several embodiments of a weatherstrip and a method for manufacturing the same according to the present invention will be described below.

[First Embodiment]
FIGS. 1A and 1B show a back door opening 3 in a state where a back door 2 is flipped up in a general two-box type passenger vehicle 1. 1a is a roof of the vehicle, and 1b is a pillar portion at the rear of the vehicle.

  As shown in FIG. 1B, the periphery of the back door opening 3 is bordered by a combination of approximately four sides (4a, 4b, 4c) and approximately four corners (5a, 5c). ing. The four sides are an upper side 4a extending substantially horizontally along the upper edge of the back door opening 3 (the rear end edge of the roof 1a), and a pair of left and right sides extending vertically along the pillar 1b. 4b, and a lower side 4c extending substantially horizontally along the lower edge of the back door opening 3. The four corners are a pair of left and right upper corners 5a located between the upper side 4a and the two sides 4b, and left and right located between the lower side 4c and the two sides 4b. It consists of a pair of lower corners 5c.

  FIG. 1A shows a state in which a weather strip 6 is attached to the periphery of the back door opening 3. The weather strip 6 has a ring shape (or an endless string shape) corresponding to the peripheral edge of the back door opening 3 and has the entire periphery of the peripheral edge of the back door opening 3 including the above-described side and corner portions. It is configured as a long rubber member having a length corresponding to the length. As described in detail below, the weather strip 6 of the first embodiment includes at least a side corresponding portion 6A as a first portion, a corner corresponding portion 6B as a second portion, a lower side corresponding portion 6C, and an upper side corresponding portion 6D. Have. However, the weather strip 6 of the first embodiment has a slightly different cross-sectional shape and size depending on the position along the longitudinal direction.

  In the specification, drawings, and claims of the present application, "inner side" and "outer side" are used as terms for specifying a direction or a direction. Here, the “inner peripheral side” of the weather strip 6 means a side facing the inside (central region) of the peripheral edge of the back door opening 3 when the weather strip 6 is attached to the back door opening 3. The “outer peripheral side” means a side facing the outside of the peripheral edge of the back door opening 3 (the surrounding external environment).

  FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, that is, a cross-sectional view of a side corresponding portion 6 </ b> A of the weather strip 6 attached to the side 4 b of the back door opening 3. As shown in this figure, the side corresponding portion 6A has a mounting portion 10 and a hollow tunnel-shaped seal portion 20A adjacent to and integrated with the mounting portion 10.

  As shown in FIG. 2, the mounting portion 10 is a portion that is directly mounted on a flange (not shown) as an object provided along the peripheral portion of the back door opening 3 and has a cross section. It has a metal core 11 (hereinafter referred to as “core 11”) bent in a “U” shape, and a rubber covering portion 12 attached so as to cover the core 11. Further, four holding lips 13 are provided on the inner portion of the rubber coating portion 12 so as to protrude from the inner surface. These holding lips 13 fix the weather strip 6 to the peripheral edge of the back door opening 3 by sandwiching the flange between them. In addition, three auxiliary lips (vehicle inner lips 14a, 14b) protrude from the outer surface near the outer portion of the rubber coating portion 12 and near one end of the mounting portion 10 (near the lower left end in FIG. 2). An outer lip 14b and a tip lip 14c) are provided. Of these three auxiliary lips, the inside lip 14a is a cover lip for covering an end of an interior material such as a carpet or a cloth material. The outer lip 14b and the tip lip 14c are for sealing a gap that may occur between the vehicle body and the mounting portion 10 when the weather strip 6 is mounted on the back door opening 3.

Further, as shown in FIG. 2, a hollow tunnel-shaped seal portion 20 </ b> A is provided adjacent to the upper side of the mounting portion 10. The seal portion 20A has an inner peripheral side wall portion 21 and an outer peripheral side wall portion 22. By being surrounded by these wall portions 21 and 22, a tunnel-shaped hollow having a substantially rhombic cross section is formed in the seal portion 20A. An area is reserved. The seal portion 20A has a border line L along one diagonal line (shown by a horizontal dashed line in FIG. 2) along one diagonal line of the rhombus formed by the two wall portions 21 and 22 in a cross-sectional view thereof. It can be divided into a side part and a head part. The “root side portion” refers to a portion adjacent to the mounting portion 10, and the “head side portion” refers to a remaining portion other than the root side portion. The wall thickness of each portion of the seal portion 20A is set as follows.
Wall thickness at the head side portion of the inner peripheral side wall portion 21 of the seal portion 20A: t1H
Wall thickness at the root side portion of the inner peripheral side wall portion 21 of the seal portion 20A: t1R
Wall thickness at the head side portion of the outer peripheral side wall portion 22 of the seal portion 20A: t2H
Wall thickness at the root side portion of the outer peripheral side wall portion 22 of the seal portion 20A: t2R
The height of the seal portion 20A with respect to the top surface of the mounting portion 10 is set to h1. The height h1 is one index indicating the size of the outer shape of the seal portion in the cross section of the seal portion 20A.

  Incidentally, the rubber material forming the rubber coating portion 12 and the four holding lips 13 of the mounting portion 10 is, for example, a compound obtained by blending carbon black and a vulcanizing agent with EPDM (ethylene propylene diene copolymer). It is obtained by vulcanization with a vulcanizing agent (that is, a polymer crosslinking reaction) in a production process described later. On the other hand, the rubber material forming the three auxiliary lips 14a to 14c and the seal portion 20A in the mounting portion 10 is, for example, a compound obtained by blending carbon black, a vulcanizing agent, and a foaming agent with EPDM, And vulcanization with a vulcanizing agent (that is, polymer crosslinking reaction) and foaming with a foaming agent (sponging). Examples of the foaming agent usable here include 4,4′-oxybis (benzenesulfonyl hydrazide) (OBSH) (for example, trade name: Neoservon, manufactured by Eiwa Chemical Co., Ltd.), azodicarbonamide (ADCA), and heat-expandable micro Capsules (for example, trade name: ADVANCEL manufactured by Sekisui Chemical Co., Ltd.), physical foaming agents (for example, water and carbon dioxide) can be exemplified. The sponge-like EPDM rubber material foamed with a foaming agent is softer and has higher flexibility than the vulcanized EPDM rubber material used for the rubber coating portion and the like.

  In the weather strip 6 of the first embodiment, the upper side corresponding portion 6D and the lower side corresponding portion 6C attached to the upper side portion 4a and the lower side portion 4c of the back door opening 3 respectively have the above-described cross-sectional shapes and dimensions. Is substantially the same as the side corresponding portion 6A.

  FIG. 3 shows a cross section taken along the line III-III in FIG. 1, that is, a cross section of the corner corresponding portion 6B of the weather strip 6 attached to the corner 5a of the back door opening 3. The corner corresponding portion 6B shown in this figure also has a mounting portion 10 and a hollow tunnel-shaped seal portion 20B. The mounting portion 10 of the corner corresponding portion 6B is substantially the same in shape and size as the mounting portion 10 of the side corresponding portion 6A.

Like the seal portion 20A of the side corresponding portion 6A, the seal portion 20B of the corner corresponding portion 6B has an inner peripheral side wall portion 21 and an outer peripheral side wall portion 22 and is surrounded by these wall portions 21 and 22. Thus, a tunnel-shaped hollow region having a substantially rhombic cross section is secured in the seal portion 20B. For convenience, the seal portion 20B has a line (shown by a horizontal dashed line in FIG. 3) along one diagonal line of the rhombus formed by the two wall portions 21 and 22 as a boundary line L in the cross-sectional view. It can be divided into a side part and a head part. The wall thickness of each part of the seal portion 20B is set as follows.
Wall thickness at the head side portion of the inner peripheral side wall portion 21 of the seal portion 20B: t3H
Wall thickness at the root side portion of the inner peripheral side wall portion 21 of the seal portion 20B: t3R
Wall thickness at the head side portion of the outer peripheral side wall portion 22 of the seal portion 20B: t4H
Wall thickness at the root side portion of the outer peripheral side wall portion 22 of the seal portion 20B: t4R
The height of the seal portion 20B with respect to the top surface of the mounting portion 10 is set to h2, and the height h2 is a value representing the size of the outer shape of the seal portion in the cross section of the seal portion 20B. There are two indicators.

The wall thickness of each portion of the wall portions 21 and 22 of the side corresponding portion 6A and the wall thickness of each portion of the wall portions 21 and 22 of the corner corresponding portion 6B are set so as to satisfy the following relationship.
Wall thickness at the head side portion of the inner peripheral side wall portion 21: t1H <t3H
Wall thickness at the head side portion of the outer peripheral side wall portion 22: t2H <t4H
Wall thickness at the root side portion of the inner peripheral side wall portion 21: t1R = t3R
Wall thickness at the root side portion of the outer peripheral side wall portion 22: t2R = t4R
That is, the wall thickness of the base side portion of the seal portion is substantially the same between the side corresponding portion 6A and the corner corresponding portion 6B. As a result, the base side portion of the seal portion 20A of the side corresponding portion 6A and the corner corresponding portion have the same thickness. The shape and dimensions of the portion 6B are substantially the same as those of the seal portion 20B at the base side, and there is no substantial difference between the two. On the other hand, regarding the wall thickness of the head side portion of the seal portion, the wall thickness (t3H, t4H) at the corner corresponding portion 6B exceeds the wall thickness (t1H, t2H) at the side corresponding portion 6A. The head-side portion of the corner corresponding portion 6B is generally thicker than the head-side portion of the side corresponding portion 6A.

  The height h2 of the seal portion 20B in the corner corresponding portion 6B is higher than the height h1 of the seal portion 20A in the side corresponding portion 6A (h1 <h2). In other words, the outer shape in the cross section of the seal portion 20B is larger than the outer shape in the cross section of the seal portion 20A.

  According to the weather strip 6 of the first embodiment, the side corresponding portion 6A as the first portion is disposed on the side portion 4b of the back door opening 3, and the corner corresponding portion 6B as the second portion is connected to the back door opening. It is arranged at the corner 5a of the section 3. At this time, since the wall thickness of the base side portion of the seal portions 20A and 20B is substantially equal between the side corresponding portion 6A and the corner corresponding portion 6B, the seal portion 20B easily conforms to the curved shape of the corner portion 5a easily. Can be bent. On the other hand, the wall thickness of the head side portions of the seal portions 20A and 20B is thicker at the corner corresponding portion 6B than at the side corresponding portion 6A, and the rigidity of the seal portion 20B at the corner corresponding portion 6B is relatively high. Has become. For this reason, it is possible to prevent the seal portion 20B from being unnaturally crushed or the seal portion 20B from being wrinkled when the corner corresponding portion 6B is bent.

  Further, the present embodiment has the following advantages. That is, even when the weather strip 6 of the present example is mounted on the back door opening 3, the side corresponding portion 6A is mounted on the side 4b extending substantially straight, so that the sealing portion 20A has some deformation action with mounting. The height of the seal portion 20A is maintained at h1 even after mounting. On the other hand, since the corner corresponding portion 6B is attached to the corner portion 5a where the degree of curvature is locally large, the seal portion 20B is inevitably affected by the bending operation at the time of attachment with attachment. The effect appears as a deforming action such that the substantially rhombic cross-sectional shape becomes flat in the height direction. Specifically, in FIG. 3, the seal portion 20B is deformed such that the upper end portion 23 of the seal portion 20B descends (or sinks) toward the mounting portion 10, and as a result, the height of the seal portion 20B after mounting is increased. The height is slightly lower than the default height h2. It is very difficult to set the initial height of the seal portion 20B to h2 = (h1 + Δh) in anticipation of the amount of decrease (subsidence amount) Δh of the seal portion height due to the bending deformation at the time of mounting. preferable. By setting such dimensions, when the weather strip 6 is mounted on the back door opening 3, the height of the seal portion 20A corresponding to the side portion 4b and the seal portion 20B corresponding to the corner portion 5a are provided. Can be made substantially the same height (i.e., h1), and as a result, the height of the seal portion after mounting is achieved, and the sealing characteristics ( Or the sealing quality) can be made constant over the entire circumference of the back door opening 3.

[Extrusion molding equipment and weather strip manufacturing method]
Next, an outline of the extrusion molding equipment will be described with reference to FIGS.
FIG. 4 shows an outline of the production line 30 of the extrusion molding equipment. The manufacturing line 30 is configured by arranging an uncoiler 31 for supplying a core metal, a head 32 for extrusion molding, a heating tank 33, a cooler 34, a core metal bending machine 35, and a take-up machine 36 in series.

  The core metal supply uncoiler 31 is a mechanism for rewinding and supplying the core metal 11 to the head 32 while unwinding a core metal coil (not shown) formed by winding the band-shaped core metal 11 to the head 32. It is. The head 32 is an extrusion mold having a die 40 and a core 50 as mold elements, and supplies a rubber material for extrusion from the first, second and third material extruders 37, 38 and 39. Receive. The head 32 will be described later in detail.

  The heating tank 33 is a long tunnel-shaped heating oven for vulcanizing treatment and foaming treatment, and its total length ranges from several meters to several tens of meters. The heating method in the heating tank 33 may be, for example, either hot air heating using combustion gas or the like, microwave heating, or both. The cooler 34 is a device for cooling a semi-finished product (intermediate product) after vulcanization and foaming treatment, and is typically configured by a water tank filled with cooling water. By passing through the water tank, the semi-finished product is cooled to an appropriate temperature. The core metal bending machine 35 is a machining device for performing bending processing on the semi-finished product after passing through the cooler 34 together with the core metal to give a rubber product a final form as a weather strip. The take-off machine 36 is a device for taking out a rubber product having the final form.

  As shown in FIG. 4, the head 32 is connected to a total of three material extruders 37, 38 and 39. The first material extruder 37 supplies the rubber material for the rubber coating portion 12 and the holding lip 13, which is an EPDM rubber material containing a vulcanizing agent, to the head 32. The second material extruder 38 supplies the head 32 with rubber materials for the auxiliary lips 14a to 14c, which are EPDM rubber materials containing a vulcanizing agent and a foaming agent. The third material extruder 39 supplies the head 32 with a rubber material for the seal portions 20A and 20B, which is an EPDM rubber material containing a vulcanizing agent and a foaming agent. The three material extruders 37 to 39 and the head 32 (particularly, the movable body driving mechanism 32a) are electrically connected to the control device C. The control device C is constituted by, for example, a computer or a programmable sequencer of factory automation (FA) specifications, and controls the head 32 and the material extruders 37 to 39 according to a predetermined control program or control sequence.

  The head 32 has a base 40 for extruding the outer shape of the weather strip 6 and a center 50 for mainly forming the inner wall portions of the hollow tunnel-shaped seal portions 20A and 20B. As shown in FIGS. 5 and 6, the base 40 supported by the frame (frame) 32 b of the head 32 has a molding space (41, 42) for extrusion molding defined at a substantially central portion thereof. I have. The lower half 41 of the molding space is a substantially horizontally extending molding space (molding region) for extruding the mounting portion 10 of the weather strip, and has a core extending straight in the lateral direction before being bent. It has a width sufficient to accommodate and pass through the gold 11. The upper half 42 of the molding space cooperates with the core 50 to provide an annular molding space (molding area) for extruding the sealing portions 20A, 20B of the weatherstrip. In this specification, the term "annular" means a cross-sectional shape of a closed meat portion that forms a tunnel inside the meat portion, and means an annular shape in a strictly geometrical sense. It does not do.

  7 and 8 show a schematic vertical cross section of the base 40 and the core 50 at the position of the line YY in FIG. As shown in these figures, in the center area of the base 40, a core metal 11 and a rubber material supply passage (main supply passage 43) extending along the extrusion direction (a direction from left to right on each drawing) are shown. The vicinity of the base outlet in the downstream area of the main supply passage 43 is positioned as the “forming space 41 for the mounting portion”. On the other hand, a housing recess 44 is provided in the upper half region of the base 40, and a movable body 45 is held in the housing recess 44 so as to be able to reciprocate back and forth in the pushing direction. The movable body 45 is driven back and forth by a movable body drive mechanism 32a (see FIGS. 4 and 5). In addition, a part (lower part) of the movable body 45 plays a role as the movable core 51.

  As shown in FIGS. 5 to 8, the core 50 to be located above the main supply passage 43 (and the molding space 41 for the mounting portion) includes a movable core 51 which is a part of the movable body 45. And a fixed core portion 52. The fixed core portion 52 is located immediately above the center position in the width direction of the main supply passage 43 (see FIGS. 5 and 6), and is a long portion (for example, a monorail-shaped portion) extending along the pushing direction. (See FIGS. 7 and 8). The rear end of the fixed core 52 is connected to the main body of the base 40, and the fixed core 52 is integrated with the base 40. The fixed core portion 52 is located at the boundary between the molding space 41 for the attachment portion of the weather strip and the annular molding space 42 for the sealing portion, and supports the movable body 45 while supporting the movable body 45. Are supported so as to be movable back and forth along the extrusion direction.

  As shown in FIGS. 7 and 8, a supply passage (sub-supply passage 46) of a rubber material for a seal portion extending in a substantially vertical direction is provided inside the base 40 and near the accommodation recess 44. The lower end of the sub supply passage 46 communicates with the annular molding space 42 for the seal portion.

  As shown in FIGS. 6 to 8, near the outlet of the base 40, a forming facing surface 47 facing the outer peripheral surface (51 a, 51 b) of the movable core 51 at a predetermined interval is formed. . An annular molding space 42 for the seal portion is secured between the molding facing surface 47 and the cores (51, 52). The outer peripheral surface (51a, 51b) of the movable core 51 is formed with a step so that the cross-sectional area of the movable core 51 is different between the upstream portion and the downstream portion along the extrusion direction. I have. Specifically, the movable center portion 51 has a first outer peripheral surface 51a located near the front end, and a second outer peripheral surface 51b located behind the first outer peripheral surface 51a. The second outer peripheral surface 51b is formed at a position higher than the first outer peripheral surface 51a. As a result, the first outer peripheral surface 51a corresponds to the small cross-sectional area portion of the movable core 51 having a relatively small cross-sectional area, and the second outer peripheral surface 51b has a cross-sectional area larger than that of the small cross-sectional area portion. Also correspond to the relatively large cross-sectional area of the movable core 51. Therefore, as shown in FIG. 7, when the movable body 45 is arranged at the forward position (first position), and the second outer peripheral surface 51b of the movable core is arranged to face the molding facing surface 47 of the base outlet. The width (and, consequently, the cross-sectional area) of the annular molding space 42 for the seal portion becomes relatively narrow. On the other hand, as shown in FIG. 8, when the movable body 45 is arranged at the retracted position (second position), and the first outer peripheral surface 51 a of the movable core portion is arranged to face the molding facing surface 47 of the base outlet. The width (and, consequently, the cross-sectional area) of the annular molding space 42 for the seal portion becomes relatively wide.

  In other words, to express this point differently, the cross-sectional shape of the movable core 51 (and the entire core 50) disposed at the retracted position (second position) at the base outlet position is the forward position (the second position). This corresponds to a shape obtained by cutting out a portion corresponding to a substantially half circumference on the upper side from the cross-sectional shape of the movable core portion 51 (and the entire core 50) arranged at (1 position) at the base outlet position ( See FIG. 6). As described above, the movable core 51 (and the entire core 50) is configured to have an irregular cross section (a section having a different cross-sectional shape) at at least two places along the extrusion direction.

  Next, a method for manufacturing a weatherstrip using the above-described extrusion molding equipment will be described. The weatherstrip 6 of the first embodiment is manufactured through an extrusion molding process using a head 32, a vulcanization and foaming process, and a subsequent post-processing and post-processing process.

  In the extrusion molding process, the weather strip semi-finished product 6 ′ is switched while appropriately changing the arrangement of the movable core 51, which is a part of the movable body 45, between a forward position (first position) and a retracted position (second position). The extrusion molding (see FIG. 9) is performed. That is, when the sealing portion 20A of the side corresponding portion 6A as the first portion of the weather strip 6 is extruded, the movable body 45 and the movable core 51 are arranged at the forward position (FIG. 7) as the first position. The second outer peripheral surface 51b of the movable core 51 is disposed to face the molding facing surface 47 of the base 40. On the other hand, when the seal portion 20B of the corner corresponding portion 6B as the second portion of the weather strip 6 is extrusion-molded, the movable body 45 and the movable core portion 51 are arranged at the retracted position (FIG. 8) as the second position, The first outer peripheral surface 51a of the movable core 51 is arranged to face the molding opposing surface 47 of the base 40. By extruding the movable core portion 51 while appropriately switching and arranging the movable core portion 51, a semi-finished product of a long weather strip having a hollow tunnel-shaped seal portion 20A and a seal portion 20B continuous in the longitudinal direction is obtained. It can be extruded continuously.

  In the above extrusion process, the control device C changes the screw rotation speed of the third material extruder 39 that supplies the rubber material for the seal portion to the head 32 according to the back and forth movement schedule of the movable core 51. Thereby, the supply amount of the rubber material to the annular molding space 42 in the base 40 is adjusted. Specifically, when the extrusion molding process is in the stage of extruding the first portion (side-side corresponding portion) 6A (that is, the seal portion 20A) (FIG. 7), the screw rotation speed of the third material extruder 39 is changed. Is reduced (decelerated), and the supply amount of the rubber material for the seal portion per unit time is relatively reduced. On the other hand, when the extrusion process is in the stage of extruding the second portion (corner corresponding portion) 6B (that is, the seal portion 20B) (FIG. 8), the screw rotation speed of the third material extruder 39 is increased. (Speed increase) to relatively increase the supply amount of the rubber material for the seal portion per unit time. By controlling the supply amount of the rubber material, it is possible to avoid a situation where the seal portions 20A and 20B of the obtained weather strip cannot be formed into a desired shape. Specifically, it is possible to avoid a situation in which the rubber material is insufficient in the seal portion 20B in which a part of the wall thickness is relatively thicker than the seal portion 20A, and it is possible to prevent a crack or a crack caused by the material shortage in the seal portion 20B. Holes can be prevented from occurring. Further, by controlling the supply amount of the rubber material as described above, the supply amount of the rubber material for the seal portion per unit area is constant (uniform) in any part of the annular molding space 42 for the seal portion. Can be As a result, in the obtained weather strip, a situation where a part of the seal portion 20B of the corner corresponding portion 6B is wavy can be avoided, and the entire surface of the seal portion 20B can be made a smooth surface.

  In the present embodiment, the control device C synchronizes (completely matches) the switching timing of the position of the movable body 45 (and the movable core portion 51) with the switching timing of the screw rotation speed of the third material extruder 39. Instead, the screw rotation speed of the material extruder 39 is changed at a timing earlier by a predetermined time (D) than the switching timing of the movable core 51. The predetermined time (D) is a time lag from the time when the screw rotation speed of the material extruder 39 changes to the time when the change in the material supply amount according to the change in the screw rotation speed actually appears in the annular molding space 42. It is set in consideration of. That is, in the present embodiment, the time lag described above is substantially eliminated by adopting a control method of changing the screw rotation speed of the material extruder 39 for the seal portion prior to the switching timing of the movable core 51. In addition, it is possible to closely synchronize the switching timing of the movable core 51 with the change timing of the material supply amount in the annular molding space 42.

  As shown in the upper half of FIG. 9, the semi-finished weatherstrip 6 ′ immediately after being discharged from the head 32 is in a state in which the core metal 11 extends straight in the lateral direction. Moreover, although the hollow tunnel-shaped seal portions 20A and 20B in the semi-finished product 6 'are continuous in the longitudinal direction, at this stage, since the foaming agent in the rubber material is not foamed, the seal portion 20A No significant difference has yet occurred between the height h1 and the height h2 of the seal portion 20B.

  The semi-finished product of the weatherstrip 6 ′ discharged from the head 32 is sent to the heating tank 33 and heated at a predetermined temperature (for example, 180 to 220 ° C.) for a predetermined time (for example, 1 to 9 minutes) before passing through the heating tank 33. Is done. By this heat treatment, the vulcanizing agent contained in the rubber material is activated and the rubber is vulcanized (polymer cross-linking reaction), and the foaming agent contained in the rubber material foams. , And expansion and sponging of the auxiliary lips 14a to 14c of the mounting portion 10 are achieved. Although the entirety of the seal portions 20A and 20B expands with the foaming of the foaming agent, the sealing portion 20A and the seal portion 20B reflect the difference in the amount of the foaming agent according to the difference in wall thickness between the seal portions 20A and 20B. The outer shape of the seal portion 20B is clearly larger than the outer shape of 20A. That is, the height h2 of the seal portion 20B is higher than the height h1 of the seal portion 20A (h1 <h2 after foaming).

  The weatherstrip semi-finished product 6 ′ that has been vulcanized and foamed in the heating tank 33 is cooled by the cooler 34. Thereafter, the mounting portion 10 of the weatherstrip semi-finished product 6 'is bent into a U-shape by the core metal bending machine 35, and the weatherstrip 6 (finished product) having the final sectional shape as shown in the lower half of FIG. ). The weatherstrip 6 that has passed through the metal core bending machine 35 is taken by a take-up machine 36, inspected for quality, and packed for shipping.

  According to the present embodiment, in the step of arranging the movable core 51 at the retracted position and extruding the corner corresponding portion 6B of the weather strip (FIG. 8), the movable core 51 is disposed at the advanced position and As compared with the step of extruding the side corresponding portion 6A (FIG. 7), the cross-sectional area of the annular molding space 42 for the seal portion at the outlet position of the die is increased, and the rubber material for the seal portion is inserted into the molding space 42. The supply per unit time is increased. For this reason, the supply amount per unit area of the sealing rubber material can be made constant (uniform) in any part of the molding space 42, and as a result, in the obtained weather strip 6, the corner corresponding portion 6B Of the seal portion 20B can be prevented from waving.

  According to the present embodiment, the core 50 that forms the annular molding space 42 in cooperation with the molding facing surface 47 of the mouthpiece 40 includes the movable core 51 and the fixed core 52. . The fixed core portion 52 functions as a support member for supporting the movable core portion 51 so as to be stably movable along the extrusion direction. The fixed core portion 52 also functions as a partition member (or partition member) for partitioning the main supply passage 43 for supplying the rubber material to the molding space 41 for the mounting portion in the base 40. The presence of the fixed core portion 52 prevents the rubber material for the seal portions 20A and 20B and the rubber material for the mounting portion 10 from being mixed randomly inside the base 40, and the two types of rubber materials are ordered. A certain distribution of weatherstrips 6 can be produced.

[Modification of First Embodiment]
In the first embodiment, the lower-side corresponding portion 6C of the weather strip 6 has substantially the same cross-sectional shape and dimensions as the side-side corresponding portion 6A and has a constant cross-sectional shape along the longitudinal direction. The portion other than the center portion has the same cross-sectional shape and dimensions as the side corresponding portion 6A (first portion), and the center of the lower side corresponding portion 6C is connected to the side corresponding portion 6A (first portion) as shown in FIG. ) And the corner corresponding portion 6 </ b> B (second portion) may be configured as a “third portion of the weatherstrip” having a different cross-sectional shape and dimensions.

  FIG. 10 is a cross-sectional view taken along the line XX in FIG. 1, that is, a cross-sectional view of the center of the lower side corresponding portion 6C of the weather strip 6 attached to the lower side 4c of the back door opening 3. The central portion of the lower side corresponding portion 6C shown in this figure also has a mounting portion 10 and a hollow tunnel-shaped seal portion 20C. The mounting portion 10 at the center of the lower side corresponding portion 6C is substantially the same in shape and size as the mounting portion 10 of the side side corresponding portion 6A.

Similarly to the seal portion 20A of the side corresponding portion 6A, the central seal portion 20C of the lower side corresponding portion 6C has an inner peripheral side wall portion 21 and an outer peripheral side wall portion 22. However, unlike the seal portion 20A, a tunnel-shaped hollow region having a substantially hexagonal cross section is secured in the seal portion 20C by being surrounded by these walls 21 and 22. The wall thickness t5 of the inner peripheral side wall portion 21 and the wall thickness t6 of the outer peripheral side wall portion 22 near the height position corresponding to the height of the boundary line L between the root side portion and the head side portion of the seal portion 20A. Is the largest. The relationship between these wall thicknesses t5 and t6 and the respective wall thicknesses in the seal portions 20A and 20B is approximately as follows.
t1H <t3H <t5 and t1R = t3R <t5
t2H <t4H <t6 and t2R = t4R <t6

  As in this modified example, of the side corresponding portion 6A and the lower side corresponding portion 6C as the first portion, a portion excluding the center portion, the corner corresponding portion 6B as the second portion, and the lower side corresponding portion 6C as the third portion. A long weatherstrip 6 having a central portion can be extruded by using a movable core 51 ′ obtained by slightly modifying the movable core 51 used in the first embodiment. is there. Specifically, as shown in FIGS. 11 (A) and (B), the movable core portion 51 ′ has a pair of left and right outer surfaces 51c that stand substantially vertically on both the left and right sides of the foremost portion, An intermediate portion adjacent to the tip portion has a first outer peripheral surface 51a similar to that of the first embodiment, and a rear portion further has a second outer peripheral surface 51b similar to that of the first embodiment. Note that, at the foremost portion of the movable center portion 51 ', a curved upper surface 51d (see FIG. 11B) connecting the upper end of the left outer surface 51c and the upper end of the right outer surface 51c has a first outer periphery. It is continuous with the surface 51a and has substantially the same shape as the first outer peripheral surface 51a.

  If the movable core 51 'as shown in FIG. 11 is used, the movable core 51' is arranged at the first position where the second outer peripheral surface 51b is arranged to face the molding facing surface 47 of the die outlet. Thereby, the part other than the center part of the side corresponding part 6A and the lower side corresponding part 6C as the first part can be extruded. In addition, by disposing the movable core 51 ′ at the second position where the first outer peripheral surface 51 a is disposed to face the molding facing surface 47 of the die outlet, the corner corresponding portion 6 B as the second portion is extrusion molded. can do. Furthermore, by disposing the movable core 51 'at a third position where the two outer surfaces 51c and the upper surface 51d are arranged to face the molding facing surface 47 of the die outlet, the lower side corresponding portion 6C as a third portion is provided. Can be extruded at the center.

  As in this modified example, it is very preferable to adopt the weather strip 6 in which the seal portion 20C at the center of the lower side corresponding portion 6C is the thickest as the weather strip for the back door opening 3. The reason is as follows. In the back door opening 3, a device for detecting the half-door state of the back door 2 is often provided near the center of the lower side 4 c together with the locking mechanism of the back door 2. . If the resilience of the sealing portion of the weatherstrip disposed around the half-door state detecting device is weak, the detecting device may return to the "half-door state" even though the back door 2 is completely closed. Erroneously detected, and the half-door warning light may be erroneously turned on. In order to minimize such erroneous lighting of the half-door warning light, it is preferable that the resilience of the seal portion of the weatherstrip disposed around the half-door state detecting device is high to some extent. Therefore, increasing the wall thickness of the seal portion 20C corresponding to the central portion of the lower side portion 4c to increase the repulsive force of the seal portion 20C is useful for preventing false lighting of the half-door warning lamp. There are advantages.

  Further, a rubber stopper may be provided at a predetermined position on a vehicle door. The sealing portion of the weather strip to be mounted around the portion where the stopper contacts the peripheral edge of the door or the door opening may be shaped like the sealing portion 20C in FIG. The reason is as follows.The stopper may be cracked and damaged by repeated opening and closing of the door, and in order to prevent such damage of the stopper, a weather strip attached around the area where the stopper hits This is because it is preferable to increase the rebound resilience of the seal portion to reduce the impact applied to the stopper when the door is closed. Therefore, the stopper can be prevented from being damaged by increasing the wall thickness relatively to increase the repulsive force of the seal portion as in the seal portion 20C in FIG. The shape for increasing the rebound resilience of the seal portion is not limited to the shape of the seal portion 20C in FIG. 10, and for example, as shown in FIG. 12, the inner surface near the top of the seal portion 20C (that is, near the upper end portion 23). It may have a shape in which a semicircular thick portion 24 is formed on the side.

[Second embodiment]
13 to 18 show a second embodiment of the present invention. Hereinafter, points different from the first embodiment will be mainly described. FIG. 13A is a diagram corresponding to FIG. 1A of the first embodiment, and FIG. 13B is the same diagram as FIG. 1B. As shown in FIG. 13A, the weather strip 6 of the second embodiment has at least a side corresponding portion 6E, a lower side corresponding portion 6F as a first portion, and an upper side corresponding portion 6G as a second portion. ing.

  FIG. 14 shows a cross section taken along the line PP in FIG. 13A, that is, a cross section of the lower side corresponding portion 6F of the weather strip 6 attached to the lower side 4c of the back door opening 3. FIG. 15 is a cross-sectional view taken along the line QQ in FIG. 13A, that is, a cross-sectional view of the upper side corresponding portion 6G of the weather strip 6 attached to the upper side 4a of the back door opening 3. . As shown in these figures, the lower side corresponding portion 6F (or the upper side corresponding portion 6G) includes a mounting portion 10 and a hollow tunnel-shaped sealing portion 20F (or a sealing portion 20G) adjacent to and integrated with the mounting portion 10. ).

  The mounting portion 10 of the lower side corresponding portion 6F and the mounting portion 10 of the upper side corresponding portion 6G are not only substantially the same in shape and size but also have the same core as the mounting portion 10 of the first embodiment (see FIGS. 2 and 3). It has a gold 11, a rubber covering portion 12, four holding lips 13, and three auxiliary lips (inside lip 14a, outside lip 14b, and tip lip 14c).

  The seal portion 20F of the lower side corresponding portion 6F and the seal portion 20G of the upper side corresponding portion 6G both have an inner peripheral side wall portion 21 and an outer peripheral side wall portion 22, and are traversed by being surrounded by these wall portions 21 and 22. A common point is that a tunnel-shaped hollow region having a substantially circular surface is secured. However, the seal portion 20G is generally thicker than the seal portion 20F, and the wall thickness t8 of the seal portion 20G is thicker than the wall thickness t7 of the seal portion 20F at the corresponding wall thickness measurement points. (T7 <t8).

  In the weather strip 6 of the second embodiment, the side corresponding portion 6E attached to the side 4b of the back door opening 3 has the lower side corresponding portion 6F (first side) in both cross-sectional shape and dimensions. Part).

  The weather strip 6 of the second embodiment shown in FIGS. 13 to 15 can be extruded using an extrusion equipment as shown in FIGS. The extrusion equipment of the second embodiment has the same basic configuration as the extrusion equipment (FIGS. 4 to 8) of the first embodiment, except for the structure of the core (particularly the movable core) and the material extrusion. The number of machines and the arrangement status are different from those of the first embodiment. Hereinafter, points different from the first embodiment will be mainly described.

  As shown in FIGS. 16 to 18, the center 60 of the second embodiment includes a movable center 61 and a fixed center 62. The fixed core portion 62 of the second embodiment has a slightly different front shape from the fixed core portion 52 of the first embodiment, but the basic functions and roles are substantially the same as those of the fixed core portion 52 of the first embodiment. Are the same.

  The movable core portion 61 of the second embodiment is configured by a part (lower portion) of the movable body 45 and extends along the pushing direction, similarly to the first embodiment. However, the movable core portion 61 is configured to have an irregular cross-section at its tip (a downstream portion in the extrusion direction) and a tip trailing portion that follows the tip (the upstream side). Specifically, as shown in FIGS. 17 and 18, the outer peripheral surface 61 a of the distal end of the movable core 61 and the outer peripheral surface 61 b of the distal end of the movable core 61 are in front of the movable core 61. The contours are formed so that the contours on the upper surface side and the right side surface side when viewed are substantially the same. On the other hand, on the left side in the front view of the movable core portion 61, it is as if the outer peripheral surface 61a of the distal end portion receded toward the center of the movable core portion 61 with respect to the outer peripheral surface 61b of the trailing end portion. In addition, both outer peripheral surfaces 61a and 61b are formed with a step. As a result, the outer peripheral surface 61a of the distal end portion of the movable core portion 61 corresponds to the small cross-sectional area portion of the movable core portion 61 having a relatively small cross-sectional area, and the outer peripheral surface 61b of the trailing end portion has a cross-sectional area of It corresponds to a large cross-sectional area of the movable core 61 that is relatively larger than the small cross-sectional area.

  Therefore, as shown in FIG. 18A, the movable core 61 (and the movable body 45) is arranged at the forward position (first position), and the outer peripheral surface 61b of the trailing end of the movable core 61 is attached to the base. In the case of being arranged to face the molding facing surface 47 of the outlet, the widths of the upper, right and left sides of the annular molding space 42 for the seal portion are all relatively narrow. On the other hand, as shown in FIG. 18 (B), the movable core 61 (and the movable body 45) is disposed at the retracted position (second position), and the outer peripheral surface 61a of the tip of the movable core 61 is connected to the base outlet. 18A, the width of the upper and right sides of the annular molding space 42 for the seal portion remains substantially the same as that of FIG. 18A. The width on the left side of the molding space 42 is relatively wider than in the case of FIG.

  In other words, to express this point in another way, the cross-sectional shape of the movable core portion 61 (and the entire core 60) disposed at the retracted position (the second position) at the base outlet position is the forward position (the second position). From the cross-sectional shape of the movable core portion 61 (and the entire core 60) disposed at (1 position) at the base outlet position, the movable core portion 61 corresponds to a shape obtained by cutting out the left portion in the left-right direction (width direction). (See FIG. 17). As described above, the movable core portion 61 (and the entire core 60) is configured to have an irregular cross-section (a portion having a different cross-sectional shape) at at least two locations along the extrusion direction.

  As shown in FIG. 16, the extrusion molding equipment of the second embodiment includes a total of four material extruders 37, 38, 391 and 392. As in the first embodiment, the first material extruder 37 supplies the rubber material for the rubber coating portion 12 and the holding lip 13, which is an EPDM rubber material containing a vulcanizing agent, to the head 32. The second material extruder 38 supplies the rubber material for the auxiliary lips 14a to 14c, which is an EPDM rubber material containing a vulcanizing agent and a foaming agent, to the head 32. On the other hand, the third and fourth material extruders 391 and 392 in the second embodiment are the same as the third material extruder 39 (the EPDM rubber material containing a vulcanizing agent and a foaming agent) in the first embodiment. For supplying the rubber material for the seal portion to the head 32) is divided into two material extruders. That is, the third material extruder 391 seals the portion (the substantially right half circumferential portion on the right side of the annular molding space 42 shown in FIG. 16) of the annular molding space 42 for the sealing portion for molding the outer peripheral side wall portion 22. It is a material extruder for the outer peripheral side of the seal part for supplying the rubber material for the part. On the other hand, the fourth material extruder 392 includes a portion for forming the inner peripheral side wall portion 21 of the annular forming space 42 for the seal portion (a substantially half circumferential portion on the left side of the annular forming space 42 shown in FIG. 16). ) Is a material extruder for the inner peripheral side of the seal portion for supplying the rubber material for the seal portion. These four material extruders 37, 38, 391 and 392, and the head 32 (particularly, the drive mechanism 32a for the movable body) are electrically connected to the control device C and controlled by the control device C.

  In the extrusion molding process of the second embodiment, similarly to the above-described first embodiment, the arrangement of the movable core 61, which is a part of the movable body 45, is defined by an advance position (first position) and a retreat position (second position). The extrusion of the semi-finished product of the weather strip is performed while appropriately switching between the above. Specifically, when extruding the seal portion 20F of the lower side corresponding portion 6F as the first portion of the weather strip, the movable core portion 61 is disposed at the forward position as the first position (see FIG. 18A). Then, an outer peripheral surface 61 b of a trailing end portion of the movable middle core portion 61 is arranged to face the molding facing surface 47 of the base 40. On the other hand, when extruding the seal portion 20G of the upper side corresponding portion 6G as the second portion of the weather strip, the movable core portion 61 is disposed at the retracted position (see FIG. 18B) as the second position, and is movable. The outer peripheral surface 61 a at the tip end of the center core portion 61 is arranged to face the molding facing surface 47 of the base 40. At this time, as can be seen from FIG. 18 (B), the left (inner peripheral side) becomes wider than the right (outer peripheral side) of the sealing portion forming space 42 at the die outlet position.

  In this extrusion molding process, the control device C changes the screw rotation speed of the fourth material extruder 392 (the material extruder for the inner peripheral side of the seal portion) in accordance with the back and forth movement schedule of the movable core 61, The supply amount of the rubber material to the left side (inner peripheral side) of the annular molding space 42 is adjusted. Specifically, when the extrusion process is in the stage of extrusion of the first portion 6F (that is, the seal portion 20F) (see FIG. 18A), the screw rotation speed of the fourth material extruder 392 is reduced. (Deceleration) to relatively reduce the supply amount of the sealing portion rubber material per unit time. On the other hand, when the extrusion process is in the stage of extrusion of the second portion 6G (that is, the seal portion 20G) (see FIG. 18B), the screw rotation speed of the fourth material extruder 392 is increased ( To increase the supply rate of the rubber material for the seal portion per unit time. As described above, even if a difference in width occurs between the right side (outer side) and the left side (inner side) of the annular molding space 42 for the seal portion in accordance with the front-rear movement of the movable core 61, By controlling the supply amount of the rubber material to the substantially half-circumferential portion on the left side (the portion for molding the inner peripheral side wall portion 21) of the sealing portion molding space 42 by the control method as described above, Also at the part, the supply amount of the rubber material for the seal portion per unit area can be made constant (uniform). As a result, in the obtained weather strip, a situation where a part of the seal portion 20G of the upper side corresponding portion 6G is wavy can be avoided, and the entire surface of the seal portion 20G can be made a smooth surface.

2 Back door (door body)
3 Back door opening (body opening)
4a Upper edge (peripheral edge)
4b Side part (peripheral part)
4c Lower edge (peripheral edge)
5a Upper corner (peripheral edge)
5c Lower corner part (peripheral part)
6 Weather Strip 6A Side Side Corresponding Part (First Part of Weather Strip)
6B corner corresponding part (second part of weather strip)
6C Lower side corresponding portion 6D Upper side corresponding portion 6E Side side corresponding portion 6F Lower side corresponding portion (first portion of weather strip)
6G upper side corresponding part (second part of weather strip)
10 Mounting parts 20A, B, C Hollow seal part 20F, G Hollow seal part 21 Inner peripheral side wall part 22 Outer peripheral side wall part 32 Head (extrusion mold)
40 Base 41 Lower half of molding space (molding space for mounting part)
42 Upper half of molding space (annular molding space for seal)
50 core 51 movable core 51a first outer peripheral surface (corresponding to small cross-sectional area of movable core 51)
51b 2nd outer peripheral surface (corresponding to the large cross-sectional area of the movable core 51)
52 Fixed middle core portion 60 Middle core 61 Movable middle core portion 61a Outer peripheral surface 61b at tip end Outer peripheral surface 62 at trailing end portion Fixed middle core portion

The present invention is a long weather strip that seals between a vehicle body opening edged by a peripheral edge and a door body capable of closing the vehicle body opening,
The weatherstrip has at least a first portion and a second portion in a longitudinal direction thereof, and has a hollow seal portion capable of abutting on a peripheral portion of the door body or the vehicle body opening, and a hollow seal portion. It has an adjacent mounting part,
In a cross section of the hollow seal portion, the hollow seal portion can be divided into a root portion adjacent to the mounting portion and a head portion that is a remaining portion other than the root portion,
The first portion and the second portion have substantially equal wall thicknesses at the root side portion, and
The wall thickness of the head-side part in the second part is thicker than the wall thickness of the head-side part in the first part,
The outer shape in the cross section of the hollow seal portion is such that the height (h2) and width of the outer shape in the second portion are larger than the height (h1) and width of the outer shape in the first portion , respectively . And a weather strip.

According to the present invention , when the weatherstrip is attached to the vehicle body, the first portion is disposed mainly on the side of the peripheral edge of the vehicle body opening, and the second portion is mainly located on the corner of the peripheral edge of the vehicle body opening. Placed in the department. At this time, since the wall thickness of the root-side portion of the hollow seal portion is substantially equal in the first portion and the second portion, the hollow seal portion of the second portion can easily follow the curved shape of the corner portion while being smoothly. It becomes possible to bend. On the other hand, since the wall thickness of the head side portion of the hollow seal portion is relatively thicker in the second portion than in the first portion, and the rigidity of the hollow seal portion in the second portion is high, the second portion is bent. However, it is possible to prevent the hollow seal portion from being unnaturally crushed or wrinkles from being generated in the hollow seal portion as much as possible.
Further, since the height and width of the outer shape in the cross section of the hollow sealing portion are relatively larger in the second portion than in the first portion, the hollow sealing of the second portion is accompanied by bending the second portion. Even if the upper end of the portion is slightly lowered, the height of the first portion and the second portion after the mounting of the weather strip to the vehicle body can be kept substantially the same, and the height of the sealing surface can be equalized. it can.

ADVANTAGE OF THE INVENTION According to the weatherstrip of this invention , by providing the hollow sealing part with a partially different wall thickness, the attachment property to a vehicle body of a weatherstrip and the sealing property after attachment can be made favorable.

Claims (5)

A method for manufacturing a long weatherstrip that seals between a vehicle body opening edged by a peripheral portion and a door body capable of closing the vehicle body opening by an extrusion molding method using an extrusion mold. ,
The long weather strip has at least a first portion and a second portion in a longitudinal direction, and has a hollow seal portion that can abut on a peripheral portion of the door body or the vehicle body opening, Regarding the wall thickness of at least a part of the hollow seal portion, the wall thickness of the hollow seal portion in the second portion is larger than the wall thickness of the hollow seal portion in the first portion,
The extrusion mold includes at least a die for molding the outer shape of the hollow seal portion, and a core for molding the inner shape of the hollow seal portion,
The core has a movable core portion movable along the extrusion direction with respect to the die,
The movable core portion has at least two positions, a first position for forming the first portion of the weatherstrip and a second position for forming the second portion of the weatherstrip. Can be placed in
Regarding the cross-sectional shape of the core at the exit position of the base, the cross-sectional shape of the core when the movable core is disposed at the first position, and the movable core is disposed at the second position. The core is formed so that the cross-sectional shape of the core when the core is not similar to the shape of the core,
Regarding the sectional area of the molding space for the hollow seal portion secured between the core and the die at the die exit position, the cutting of the molding space when the movable core is disposed at the first position. The core is formed such that the cross-sectional area of the molding space when the movable core portion is arranged at the second position is larger than the area,
The method is
A) a step of molding the first portion of the weatherstrip with the movable core located at the first position;
B) forming the second portion of the weatherstrip with the movable core located at the second position;
In the step B), the supply amount of the sealing portion material per unit time to the molding space secured between the core and the die is set to be smaller than the supply amount in the step A). increase,
A method for producing a weather strip. The long weather strip further includes a mounting portion adjacent to the hollow seal portion in a cross section thereof,
The core is composed of the movable core, and a fixed core for movably supporting the movable core along the extrusion direction,
The fixed core portion is extended along the extrusion direction in a state of being integrated with the die, and a molding space for a hollow seal portion secured between the core and the die, It is arranged at the boundary with the molding space for the mounting part secured in the base,
The method for manufacturing a weatherstrip according to claim 1, wherein:   The movable core has a cross-sectional shape at the mouth exit position of the movable core located at the first position and a cross-sectional shape at the mouth exit position of the movable core located at the second position. Similar, and so that the cross-sectional area of the movable core portion located at the first position at the die exit position is larger than the cross-sectional area of the movable core portion located at the second position at the die exit position. The method for producing a weatherstrip according to claim 1 or 2, wherein the cross-sectional shape is different at least at two points along the extrusion direction.   The cross-sectional shape of the movable core located at the second position at the die outlet position corresponds to a shape in which the cross-sectional shape of the movable core located at the first position at the die exit position is partially cut away. The method of manufacturing a weatherstrip according to claim 3, wherein A long weather strip that seals between a vehicle body opening edged by a peripheral edge and a door body capable of closing the vehicle body opening,
The weatherstrip has at least a first portion and a second portion in a longitudinal direction thereof, and has a hollow seal portion capable of abutting on a peripheral portion of the door body or the vehicle body opening, and a hollow seal portion. It has an adjacent mounting part,
In a cross section of the hollow seal portion, the hollow seal portion can be divided into a root portion adjacent to the mounting portion and a head portion that is a remaining portion other than the root portion,
The first portion and the second portion have substantially equal wall thicknesses at the root side portion, and
The wall thickness of the head-side part in the second part is thicker than the wall thickness of the head-side part in the first part,
The outer shape of the hollow seal portion in a transverse cross section is such that a circumference of the outer shape in the second portion is larger than a circumference of the outer shape in the first portion.

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