JP5152664B2 - Weather strip for automobile - Google Patents

Description

The present invention relates to an automotive weather strip that is attached to the periphery of a vehicle body opening of a vehicle body and seals between the periphery of the vehicle body opening and an opening opening / closing member. More particularly, the present invention relates to an automobile weather strip having a trim portion attached to a flange portion formed on a periphery of a vehicle body opening portion or an opening portion opening / closing member, and a seal portion that contacts and seals the opening portion opening / closing member or the vehicle body opening portion periphery. It is.
The present invention will be described by taking as an example an opening trim weather strip that is attached to a flange at the periphery of a vehicle body opening, contacts the door when the automobile door is closed, and seals between the door and the vehicle body.

As shown in FIG. 4, the opening trim weather strip 110 attached to the vehicle body opening peripheral edge 6 of the automobile body is formed by extrusion molding, and includes a trim portion 120, a cover lip 130, and a hollow seal portion 140. Yes.
The trim portion 120 has a substantially U-shaped cross section, and holds the flange portion 9 formed on the periphery 6 of the vehicle body opening, and attaches the opening trim weather strip 110 over the entire periphery of the vehicle body opening. The trim part 120 has an insert member 126 embedded therein, and an inner side holding lip 124 and an inner side holding lip 125 that hold the flange part 9 are formed on the inner surface of the U-shaped cross section. , 125 are held by the flange portion 9 of the vehicle body 1.

  The hollow seal portion 140 is integrally formed on the outer surface of the trim portion 120 on the vehicle outer side, and contacts the outer periphery of the door 2 when the door 2 is closed, and between the door 2 and the vehicle body opening peripheral edge 6. Is sealed. The hollow seal portion 140 is formed of a rubber sponge material so as to flexibly come into contact with the shape of the door 2 and securely seal. Normally, this sponge material is made of EPDM sponge rubber having a specific gravity of 0.4 to 0.6 and a 25% elongation stress of 140 KPa to 190 KPa in consideration of flexibility, weather resistance, elongation and rigidity. Here, when the specific gravity is less than 0.4, a predetermined rigidity (25% elongation stress) cannot be obtained, and it becomes difficult to obtain a seal pressure when the door is closed, and the vehicle is curved along the corner of the peripheral edge 6 of the vehicle body opening. If the specific gravity is greater than 0.6, the rigidity is increased and the door closing force is increased.

  The cover lip 130 extends from the outer surface of the trim portion 120 toward the inside of the vehicle, contacts the garnish provided in the vehicle, and covers the gap between the opening trim weather strip 110 and the garnish or the vehicle body. doing. A surface layer 133 made of a thermoplastic thermoplastic elastomer material is provided on the surface of the cover lip 130 for decoration.

In such an opening trim weather strip 110, in order to securely hold the flange portion 9, the trim portion 120 has an insert member 126 embedded therein, and the vehicle outer side holding lip 124 and the vehicle inner side holding lip 125 are embedded therein. As a material for covering the insert member 126, a solid material of EPDM rubber has been used. The specific gravity of this EPDM rubber solid material was about 1.2 to 1.3, and the 25% elongation stress was a large value of 800 KPa or more, and had sufficient rigidity. Therefore, the trim portion 120 made of a solid material of EPDM rubber can hold the flange portion 9 between the vehicle outer side holding lip 124 and the vehicle inner side holding lip 125 and stably hold the mounting posture.
However, in recent years, it has been required to reduce the weight of automobiles in order to protect the global environment. In order to reduce the weight of automobiles, it is necessary to reduce the weight of the opening trim weatherstrip 110 and the like. (For example, refer to Patent Documents 1 to 4).

  However, the solid material that is slightly foamed has a specific gravity of about 0.8 to 1.05, and the weight reduction is less than that of a normal sponge material having a specific gravity of about 0.4 to 0.6. It was enough. This is because when the foaming rate is increased from a solid material (specific gravity 1.2 to 1.3) to a normal sponge material (having a specific gravity of about 0.4 to 0.6) as a covering material, When the trim portion 120 is attached to the flange portion 9 on the upper side of the door opening portion, the rigidity of the inner side lip 125 and the inner side holding lip 125 is too low (25% elongation stress is 140 to 190 KPa). The drop load is reduced due to the reduction of the clamping force by the lip 124 and the vehicle interior holding lip 125, the trim part 120 is easily removed from the flange part 9, and the opening trim weather strip 110 is formed at the corner part of the door opening part periphery. When trimmed and curved, the trim part 120 is inclined and the hollow seal part 140 is displaced from a predetermined position, so that the sealing performance cannot be secured. I had to bear.

By the way, in order to secure the rigidity of the vehicle outer side holding lip 124 and the vehicle inner side holding lip 125, it is only necessary to increase the thickness of the vehicle outer side holding lip 124 and the vehicle inner side holding lip 125. The inside of the was narrow and there was a limit to increasing its thickness. When the vehicle outer side holding lip 124 and the vehicle inner side holding lip 125 are formed of a normal sponge material, in order to obtain rigidity equivalent to that of a solid material or a fine foam material, the thickness (about 1.0 to 1.5 mm) It was necessary to increase it to more than twice, which was not practical.
In addition, the thickness of the vehicle outer side holding lip 124 and the vehicle inner side holding lip 125 is the same as the conventional thickness, and when the specific gravity is adjusted to 0.6 to 0.8 by adding a large amount of a foaming agent to the fine foam material, the elongation is 25%. The stress was 200 KPa to 350 KPa, and the specific gravity was less than half that of the conventional fine foam material having a specific gravity of about 0.8 to 1.05, and the function as the trim part 120 was not exhibited.

Japanese Utility Model Publication No.57-153050 JP-A-11-193335 JP 2000-264135 A JP 2002-316537 A

As described above, the solid material forming the trim portion 120 has a specific gravity of about 1.2, and the fine foam material has a specific gravity of about 0.8 to 1.05. (About 0.5 to 0.8) is demanded.
However, if the microfoam material is further foamed as described above to reduce the specific gravity, it is preferable to reduce the weight, but the rigidity is lowered, and the function of the trim portion 120 as the mounting portion is reduced. It will not be demonstrated.

  For this reason, the weather strip is further reduced in weight, the rigidity is secured without greatly changing the outer shape of the vehicle outer side holding lip 124 and the vehicle inner side holding lip 125, and it is difficult to come out from the flange portion 9. It has been desired to obtain a weather strip for automobiles that can maintain the mounting posture and can be easily manufactured at low cost.

In order to solve the above-mentioned problems, the present invention of claim 1 is directed to a weather strip for an automobile which is attached to the periphery of a vehicle body opening of a vehicle body and seals between the periphery of the vehicle body opening and the opening opening / closing member. A weather strip for an automobile is integrally formed on a trim portion having a substantially U-shaped cross section that is attached to a peripheral edge of the vehicle body opening or a flange portion of the opening opening / closing member and holds the weather strip, and an outer surface of the trim portion. The opening portion opening / closing member or a seal portion that contacts and seals the periphery of the opening portion, and the trim portion includes an insert member and a covering material that covers the insert member. Form a holding lip that holds the flange,
The coating material uses a blend material of 100 parts by weight of EPDM rubber and 12 to 20 parts by weight of ethylene octene resin , has a specific gravity of 0.6 to 0.8, and has a physical property of 25% elongation stress of 500 KPa or more. Use rubber sponge material,
The seal part is made of a rubber sponge material using EPDM rubber not blended with ethylene / octene resin , having a specific gravity of 0.4 to 0.6, and a physical property of 25% elongation stress of 200 KPa or less. This is a weather strip for automobiles.

  In the first aspect of the present invention, the automobile weather strip includes a trim portion having a substantially U-shaped cross section that is attached to the periphery of the vehicle body opening or the flange portion of the opening opening / closing member and holds the weather strip, and an outer surface of the trim portion. It has a seal portion that protrudes and is integrally formed and abuts and seals against the opening / closing member or the periphery of the vehicle body opening. For this reason, when the trim portion is attached to the periphery of the vehicle body opening or the flange portion of the opening / closing member, the seal portion reliably contacts the opening / closing member or the vehicle body opening periphery to open / close the vehicle body opening periphery and the opening / closing portion. The space between the members can be sealed.

  The trim part has an insert member inside, and has a covering material that covers the insert member. Further, the covering material of the trim portion forms a holding lip that holds the flange portion on the inner surface having a substantially U-shaped cross section. For this reason, the outer shape of the trim portion is maintained by the insert member, and the force for gripping the flange portion of the vehicle body or the like is increased, so that the weather strip can be securely attached. Moreover, since an insert member is coat | covered with a coating | covering material, while improving the beauty | look, corrosion of an insert member can be prevented.

The covering material is a rubber having a physical property of 100 parts by weight of EPDM rubber and 12 to 20 parts by weight of ethylene octene resin , having a specific gravity of 0.6 to 0.8 and a 25% elongation stress of 500 KPa or more. The sponge material was used. For this reason, the weight of the trim portion of the weather strip can be reduced, and the holding lip formed on the inner surface of the trim portion having a substantially U-shaped cross section can have sufficient rigidity. By increasing the size, the trim portion can securely grip the flange portion.
The rubber sponge material is a blend of 100 parts by weight of EPDM rubber and 12 to 20 parts by weight of ethylene octene resin. By blending ethylene octene resin and / or increasing the crosslinking density of EPDM rubber, rigidity is increased. Can be raised. Therefore, even if the outer shape of the holding lip is not greatly changed, the shape can be maintained, and sufficient rigidity can be provided even in the clamping of the flange portion.When the trim portion is about to come off from the flange portion, The removal load is increased to make it difficult to remove, and the load is not increased when the trim portion is inserted into the flange portion .
The elasticity and rigidity can be adjusted by adjusting the blend ratio of ethylene-octene resin . Therefore, the holding lip has an appropriate flexibility (elasticity), and even if the thickness of the flange portion changes, the holding force can be maintained by the bending of the holding lip. The flange portion can be securely gripped according to bending or bending.

The seal portion is made of an EPDM rubber not blended with ethylene-octene resin , and is formed of a rubber sponge material having a specific gravity of 0.4 to 0.6 and a physical property of 25% elongation stress of 200 KPa or less. Yes. For this reason, the weight of a seal part can be reduced and the whole weather strip can be reduced in weight.
In addition, since it is formed of a sponge material having a physical property of 25% elongation stress of 200 Kpa or less, it is excellent in flexibility and reliably deforms according to the shape of the mating member when the seal portion comes into contact with the mating member. While being able to seal, the increase in door closing force can be suppressed.

According to a second aspect of the present invention, the trim portion has a cover lip that is integrally formed to extend from the outer surface to the vehicle interior, and the cover lip is made of a blend material of the EPDM rubber and ethylene octene resin. An automotive weather strip formed of a rubber sponge material.

According to the present invention of claim 2, a rubber sponge material having a cover lip formed integrally with the trim part, the molding material of which is the same blend material of EPDM rubber and ethylene octene resin as the covering material of the trim part Therefore, the cover lip can cover between the weather strip and the interior member of the vehicle body or the garnish, so that the aesthetic appearance can be improved.
Further, since the cover lip is formed of the rubber sponge material, the weight of the cover lip can be reduced, which contributes to the weight reduction of the automobile.
Furthermore, the rubber sponge material is the same EPDM rubber and ethylene octene resin blend material as the coating material, and blends the ethylene octene resin and / or increases the crosslinking density of the EPDM rubber to increase the rigidity. The blend ratio can be adjusted to adjust the elasticity and rigidity. Therefore, even if the cover lip is in the form of a lip, the shape of the cover lip can be maintained, and sufficient contact force can be provided in contact with a mating member such as garnish.

  According to a third aspect of the present invention, the seal portion is a weather strip for an automobile having a hollow shape.

  According to the third aspect of the present invention, since the seal portion is hollow, the seal portion abuts against the door or the vehicle body opening periphery which is the opening / closing member when the door is closed, and is easily deformed. It is possible to reliably contact the unevenness and curved surface of the. Further, even when the door is closed, it does not deform abnormally compared to the lip shape, and even if there is a variation in the dimensions of the vehicle body or the door, it can be reliably sealed.

  According to a fourth aspect of the present invention, there is provided an automotive weather strip in which outer surfaces of the seal portion and the cover lip are covered with a solid material.

  In the present invention of claim 4, since the outer surfaces of the seal portion and the cover lip are covered with the solid material, the surfaces are smooth and the aesthetic appearance can be improved. The seal part is made of a rubber sponge material with physical properties such that the inner part has a specific gravity of 0.4 to 0.6 and a 25% elongation stress of 200 Kpa or less, so the weight of the seal part can be reduced. The entire weather strip can be reduced in weight. However, since the inner part is a sponge material, unevenness due to foaming occurs on the outer surface. In order to make the unevenness inconspicuous and to improve the wear resistance of the surface, it is coated with a solid rubber material. Similarly, the cover lip is also made of sponge material on the inner side, so that irregularities due to foaming occur on the outer surface. In order to make the unevenness inconspicuous and to improve the wear resistance of the surface, it is coated with a solid material of a thermoplastic elastomer.

Since the covering material forms a holding lip that holds the flange portion on the inner surface of the trim portion having a substantially U-shaped cross section, the flange portion is securely held by the holding lip, and the flange portion is securely attached in accordance with the unevenness or bending of the flange portion. It can be gripped.
As a coating material, a blend material of 100 parts by weight of EPDM rubber and 12 to 20 parts by weight of ethylene octene resin is used. The specific gravity is 0.6 to 0.8 and 25% tensile stress is 500 KPa or more. Since the sponge material is used, the weight of the trim portion of the weather strip can be reduced, the holding lip can have sufficient rigidity, and the trim portion can securely grip the flange portion.

  The embodiment of the present invention will be described with reference to FIGS. 1 to 3, taking an opening trim weather strip as an example. In addition to the opening trim weather strip 10, the present invention is applied to a roof weather strip, a door weather strip, a back door weather strip, a luggage weather strip and the like having a trim portion as a mounting portion having a substantially U-shaped cross section. can do.

  FIG. 1 is a sectional view of an opening trim weather strip 10 according to a first embodiment of the present invention. FIG. 2 is a perspective view of the automobile with the door 2 opened as viewed from the rear. FIG. 3 is a conceptual diagram showing a process of manufacturing the opening trim weather strip 10 of the present invention by extrusion molding. Table 1 is a table showing the material composition and physical property values of the coating material.

As shown in FIG. 2, the opening trim weather strip 10 of the present invention is against a flange portion 9 formed at a vehicle body opening peripheral edge 6 of a vehicle body opening portion that is opened and closed by a door 2 that is an opening portion opening / closing member. The ring is attached to the entire circumference.
FIG. 1 is a cross-sectional view of an opening trim weather strip 10 according to an embodiment of the present invention. The opening trim weather strip 10 includes a trim portion 20 as an attachment portion, a cover lip 30, and a hollow seal portion 40. As will be described later, a skin layer 33 is provided on the upper surface of the cover lip 30.

  The trim portion 20 has a substantially U-shaped cross section formed by a vehicle outer side wall 21, a vehicle inner side wall 22, and a bottom wall 23, and an insert member 26 is embedded therein. Further, a cover lip 30 extending from the outer surface of the bottom wall 23 toward the vehicle interior side is provided. As shown in FIG. 1, a plurality of vehicle outer side holding lips 24 and one vehicle inner side holding lip 25 are provided on the inner surface of the trim portion 20 having a substantially U-shaped cross section.

  The flange portion 9 of the vehicle body opening rim 6 is inserted into the inner portion of the trim portion 20 having a substantially U-shaped cross section, and is sandwiched between the vehicle outer side holding lip 24 and the vehicle inner side holding lip 25, and the opening trim weather strip 10 is connected to the flange. Mounted on the part 9. Therefore, the trim part 20 plays the role of an attachment part.

  In the present embodiment, the vehicle outer side holding lip 24 is three short lips, and is continuously formed in the longitudinal direction on the inner surface of the vehicle outer side wall 21 of the trim portion 20. The vehicle outer side holding lip 24 is in contact with the side surface of the flange portion 9 and holds the vehicle outer side wall 21 parallel to the flange portion 9. For this reason, the hollow seal portion 40 formed on the outer surface of the outer side wall 21 of the trim portion 20 is surely brought into contact with the door 2 as a counterpart member, and the sealing performance between the door 2 and the vehicle body opening peripheral edge 6 is improved. Can be secured.

  The vehicle interior holding lip 25 is formed as one lip longer than the vehicle exterior holding lip 24. Since it is a long lip, even if the wall thickness of the flange portion 9 changes, the vehicle inner side holding lip 25 has an appropriate rigidity and is easily bent, and the flange portion 9 can be reliably held. Further, when the flange portion 9 is inserted, the insertion force is reduced. On the other hand, when the flange portion 9 is to be removed, the flexibility can prevent the trim portion 20 from coming off due to its flexibility. .

The covering material of the trim part 20 is composed mainly of sulfur-crosslinked EPDM rubber having a specific gravity of 0.6 to 0.8 and a 25% elongation stress of 500 KPa or more, and is blended with an olefinic thermoplastic resin. A rubber sponge material is used.
The 25% elongation stress is defined by JISK6254, and is a measurement of the static elastic modulus at low deformation of vulcanized rubber.

In the rubber sponge material, 12 to 20 parts by weight of olefinic thermoplastic resin is blended with 100 parts by weight of EPDM rubber. When the blend amount of the olefinic thermoplastic resin is less than 12 parts by weight, it is difficult to make the 25% elongation stress 500 KPa or more. In addition to the blend of the olefinic thermoplastic resin, the 25% elongation stress is 500 KPa or more. Therefore, it is necessary to increase the crosslink density by using special EPDM rubber in which the blending amount of diene (double bond part) in EPDM rubber is considerably larger than the usual blending amount. The manufacturing cost of the trim weather strip 10 increases, which is not practical.
On the other hand, if the olefinic thermoplastic resin is blended in excess of 20 parts by weight, the 25% elongation stress can easily be increased to 500 KPa or more, but the flexibility of the trim part 20, the vehicle outer side holding lip 24, and the vehicle inner side holding lip 25 is improved. When the opening trim weather strip 10 is attached to the corner of the periphery of the vehicle body opening, the trim portion 20 hardly follows the curvature, and the flange portion 9 is inserted when the flange portion 9 of the vehicle body is inserted. 9 is increased, and further, there is a problem of trying to come out from the flange portion 9 at the corner portion of the periphery of the vehicle body opening due to the force of returning to the linear shape which is the extrusion molding state.
As the olefinic thermoplastic resin, those having good compatibility with EPDM rubber such as polyethylene resin, polypropylene resin, ethylene / octene resin can be used. In Examples 1 and 2 shown in Table 1, ethylene octene resin was used.

  As shown in Table 1, the rubber sponge materials of Examples 1 and 2 were blended with 12 parts by weight and 20 parts by weight of ethylene octene resin, which is an olefinic thermoplastic synthetic resin, with respect to 100 parts by weight of EPDM. The rigidity (25% elongation stress) is larger than those of Comparative Examples 3 and 4 in which the resin is not blended. Further, compared to Comparative Example 1 of the fine foam material in which the resin is blended, the specific gravity is larger in Comparative Example 1 and the weight reduction is not satisfied. Therefore, Comparative Example 2 is obtained by adjusting the material of Comparative Example 1 to have a specific gravity of 0.7 by increasing the foaming agent. However, when the foaming ratio is simply increased to reduce the weight, the rigidity (25% elongation stress) is obtained. ) Is greatly reduced. On the other hand, in Example 1, the amount of diene in EPDM was increased, the crosslink density of rubber was increased, and the rigidity could be increased.

The rubber sponge material as the coating material of Example 1 or Example 2 in Table 1 has a specific gravity within 0.6 to 0.8 (specific gravity 0.7) and a 25% elongation stress of 500 KPa or more (580 KPa, 530 KPa). ). For this reason, the vehicle outer side holding lip 24 and the vehicle inner side holding lip 25 can have sufficient rigidity and flexibility. And while the trim part 20 can hold | grip the flange part 9 reliably, when the trim part 20 tries to remove | deviate from the flange part 9, the removal load is enlarged and it is hard to come off.
Further, even if the covering material is formed of the rubber sponge material, the thickness of the vehicle outer side holding lip 24 and the vehicle inner side holding lip 25 can be set to a normal thickness of about 1.0 mm to 1.5 mm. . For this reason, when inserting the flange part 9 in the inner part of the cross-sectional substantially U shape of the trim part 20, a load is not increased.

Furthermore, an insert member 26 is embedded in the covering material of the trim portion 20. Therefore, even if the trim part 20 is formed of the above sponge material, the trim part 20 has a substantially U-shaped cross section, and as a result, a sufficient holding force for the flange part 9 can be secured.
Further, since the covering material of the trim portion 20 is formed of a rubber sponge material, the weight can be reduced and the weight of the opening trim weather strip 10 can be reduced.

  As described above, the cover lip 30 is integrally extended in the vehicle interior direction in an arc shape from the outer surface of the bottom wall 23 of the trim portion 20 and the lower surface in FIG. The cover lip 30 is formed on the vehicle inner side than a hollow seal portion 40 described later. A cover lip front end portion 32 which is a front end portion of the cover lip 30 abuts on a garnish 50 mounted in the vehicle, covers the gap between the garnish 50 and the opening trim weather strip 10, and improves the appearance. In a portion where the garnish 50 is not provided, the gap is covered by abutting against another interior member in the vehicle, a ceiling adhesive, and the like.

The cover lip 30 is formed of a cover lip body 31 and a skin layer 33 that covers the cover lip body 31. The cover lip body 31 is integrally formed of the same material as the rubber sponge material of the covering material that forms the trim portion 20. For this reason, the weight of the cover lip 30 can be reduced, and it can contribute to weight reduction of the opening trim weather strip 10. Further, since the rigidity and flexibility of the cover lip 30 are increased, the cover lip 30 can be easily brought into contact with the garnish 50 without a gap.
In terms of weight reduction, it is more advantageous to use an EPDM rubber sponge material having a normal specific gravity of 0.4 to 0.6 applied to the seal portion 40, but the cover lip 30 is in the form of a lip. Therefore, a material with low specific gravity and low rigidity may not be able to maintain its shape, and sufficient contact force may not be obtained even in contact with a mating member such as garnish. A sponge material with medium specific gravity and high rigidity shown in Example 1 of Table 1 was used.
However, even though the medium specific gravity is used, since the sponge material is used for the trim part 20 and the cover lip body 31, the weight of the trim trim 20 and the cover lip body 31 can be greatly reduced compared to the conventional fine foam material. It was possible to greatly reduce.

A skin layer 33 is fixed to the outer surface of the bottom wall 23 of the trim portion 20 and the upper surface (lower surface in FIG. 1) of the cover lip 30. Although the upper surface of the cover lip 30 can be seen from the vehicle interior side, the trim portion 20 and the cover lip 30 are sponge materials having a specific gravity of 0.6 to 0.8, and therefore have irregularities on the surface. However, if the skin layer 33 is formed of a thermoplastic elastomer solid material, the surface becomes smooth and the aesthetic appearance can be improved.
Here, the material of the skin layer 33 is a thermoplastic elastomer solid material, as will be described later, because a sheet-like thermoplastic elastomer solid material can be attached after the vulcanization and foaming steps, In the case of a shape difficult to be pasted, the skin layer 33 may be formed by coextrusion molding of a rubber solid material.

Moreover, it is necessary to change the surface pattern of this skin layer 33 in accordance with the color and luster of the interior of the automobile in terms of design, and use the skin layer 33 having a surface pattern harmonized with the interior. Can do.
The skin layer 33 completely covers the cover lip tip 32 of the cover lip body 31 and reaches the inner surface side of the cover lip body 31.

When the skin layer 33 is made of a solid material of thermoplastic elastomer, it can prevent the surface from generating irregularities such as air bubbles, is harmonized with the surface texture pattern such as garnish, and has a good appearance. Can be reliably transferred.
Further, since the thermoplastic elastomer is used, even when the other part of the opening trim weather strip 10 is formed of a sponge material, the thermoplastic elastomer skin layer 33 is pressure-bonded after the sponge material is vulcanized and foamed. be able to.
When the cover lip body 31 is formed of a normal sponge material having a specific gravity of 0.4 to 0.6 and 200 KPa or less, after the sponge material is vulcanized and foamed, the thermoplastic elastomer skin layer 33 is removed by a pressing roller. Although it is difficult to press-bond (the rigidity of the sponge material is low and the roller cannot be pressure-bonded), in the present invention, since the sponge material has high rigidity, the skin layer 33 can be pressed by the pressing roller.

  As the thermoplastic elastomer, when the cover lip body 31 is formed of a material containing EPDM rubber and an olefinic thermoplastic resin, an olefinic thermoplastic elastomer can be used. In this case, it is preferable because the skin layer 33 easily melts with the cover lip body 31 and welding between the cover lip body 31 and the skin layer 33 becomes strong.

  The olefinic thermoplastic elastomer preferably has a rubber to resin weight ratio of 70:30 to 80:20. As the rubber component, EPDM rubber and an oil component are preferable, and as the resin component, a polypropylene resin or an olefin-based thermoplastic elastomer is preferable.

  The hollow seal portion 40 is formed integrally with the outer surface of the vehicle exterior side wall 21 of the trim portion 20 in the vehicle exterior direction. The hollow seal portion 40 includes a hollow seal portion inner wall 41 and a hollow seal portion skin layer 42. The hollow seal portion inner wall 41 is integrally formed from a hollow seal portion root portion 43 extending from the vehicle exterior side wall 21 of the trim portion 20.

The hollow seal portion inner wall 41 of the hollow seal portion 40 has a specific gravity of 0.4 to 0.6, which is not blended with an olefin-based thermoplastic resin, except for the root portion 43 of the hollow seal portion, and extends by 25%. It is formed of a rubber sponge material having a physical property of stress of 200 Kpa or less.
Therefore, the weight of the hollow seal portion 40 can be reduced, and the entire opening trim weather strip 10 can be reduced in weight.

In addition, since the hollow seal portion 40 is excellent in flexibility because it is formed of the above-described sponge material, when the hollow seal portion 40 abuts against the door 2 that is a counterpart member, unevenness and curved surfaces such as the door frame of the door 2 are curved. It can be deformed according to the shape and can be reliably sealed, and the closing force of the door 2 can be reduced.
In addition, the sponge material of the rubber | gum which has the specific gravity of 0.4-0.6 of EPDM rubber | gum which the hollow seal part base part 43 is not mix | blended with an olefin type thermoplastic resin, and 25% elongation stress is 200 Kpa or less The reason for not forming is to prevent the hollow seal portion 40 from being deformed abnormally so that the hollow seal portion is crushed due to insufficient rigidity when the hollow seal portion 40 is curvedly mounted along the corner portion of the vehicle body opening periphery 6. .

The hollow seal portion skin layer 42 is preferably made of an EPDM solid rubber material. This is because the hollow seal portion 40 has a curved portion with a small curvature and is difficult to be bonded in a later process. If there is no curved portion with a small curvature, the thermoplastic elastomer is the same as the skin layer 33. It can also be composed of solid materials.
In this case, as the thermoplastic elastomer, when the hollow seal portion inner wall 41 is formed of EPDM sponge rubber, it is preferable to use an olefin-based thermoplastic elastomer, and the hollow seal portion inner wall 41, the hollow seal portion skin layer 42, The welding becomes stronger.

Next, a method for manufacturing the opening trim weather strip 10 will be described. FIG. 3 is a schematic diagram showing a part of the production line of the opening trim weather strip 10.
In the opening trim weather strip 10, first, the trim portion 20, the cover lip main body 31, and the hollow seal portion 40 are formed by an extruder 61.

  The insert member 26 is supplied to the extrusion molding machine 61, and the specific gravity is 0.6 to 0.8 using a blending material of the trim part 20 and the cover material of the cover lip body 31 of EPDM rubber and olefin-based thermoplastic synthetic resin. In addition, a rubber sponge material having a physical property of 25% elongation stress of 500 KPa or more and an EPDM rubber not blended with an olefin-based thermoplastic synthetic resin for the hollow seal portion 40 are used, and the specific gravity is 0.4-0. 6 and a rubber sponge material having a physical property of 25% elongation stress of 200 KPa or less is extruded together with the insert member 26.

  Further, when the hollow seal portion skin layer 42 is a rubber solid material, it is formed by extruding the above sponge materials at the same time. Then, these integral extrudates are transferred to a high-frequency heating furnace 62, a hot air heating furnace 63, etc., and heated to vulcanize and foam.

  Thereafter, the vulcanized and foamed integral extrudate such as the trim portion 20 is sent to an extrusion die to which a nozzle of an extruder 64 for extruding the skin layer 33 of the cover lip 30 is attached. Here, a skin layer 33 having a color corresponding to the interior of the vehicle is extruded into a sheet shape on the upper surface of the cover lip body 31 of the vulcanized and foamed integral extrudate.

After the skin layer 33 is extruded onto the upper surface of the cover lip body 31, as shown in FIG. 3, the skin layer 33 is sent to the pressing roller 65 and pressed against the cover lip body 31 by the pressing roller 65. At this time, a pattern may be formed on the surface of the skin layer 33.
Further, the bending roller 66 causes the end of the side portion of the skin layer 33 to wrap around the back surface of the cover lip tip 32, and the cover lip body 31 and the skin layer 33 are pressure bonded.

The opening trim weather strip 10 to which the skin layer 33 is fixed is sent to a cooling bath (not shown) and cooled by water or cold air.
The vulcanized and foamed monolithic extrudate that has come out of the cooling bath (not shown) is taken up by a take-up machine (not shown), and its trim portion 20 is bent into a substantially U-shaped cross section so that a predetermined dimension is obtained. If necessary, the terminal portion is bonded to form the opening trim weather strip 10. Depending on the opening trim weather strip 10, there may be a product to which a double-sided adhesive tape, a clip, or the like is attached.

3 is a sectional shape of an opening trim weather strip according to an embodiment of the present invention. It is the perspective view which looked at the motor vehicle from the back in the state where the door was opened. FIG. 5 is a schematic view of a process for manufacturing the opening trim weather strip according to the embodiment of the present invention. It is the cross-sectional shape of the conventional opening trim weather strip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Opening trim weather strip 20 Trim part 26 Insert member 24 Car outer side holding lip 25 Car inner side holding lip 30 Cover lip 40 Hollow seal part

Claims (4)

In an automobile weather strip that is attached to the periphery of a vehicle body opening of an automobile body and seals between the periphery of the vehicle body opening and an opening opening / closing member,
The automobile weather strip is formed integrally with a trim portion having a substantially U-shaped cross section which is attached to the periphery of the opening of the vehicle body or the flange portion of the opening / closing member and holds the weather strip, and an outer surface of the trim portion. A seal portion that seals against the opening / closing member or the periphery of the opening;
The trim portion has an insert member and a covering material that covers the insert member, and forms a holding lip that holds the flange portion on the inner surface of the U-shaped cross section.
The coating material uses a blend material of 100 parts by weight of EPDM rubber and 12 to 20 parts by weight of ethylene octene resin , has a specific gravity of 0.6 to 0.8, and has a physical property of 25% elongation stress of 500 KPa or more. Use rubber sponge material,
The seal part is made of a rubber sponge material using EPDM rubber not blended with ethylene / octene resin , having a specific gravity of 0.4 to 0.6, and a physical property of 25% elongation stress of 200 KPa or less. A weather strip for automobiles. The trim portion has a cover lip that is integrally formed to extend from the outer surface to the inside of the vehicle. The cover lip is formed of a rubber sponge material that is a blend material of the EPDM rubber and ethylene octene resin. 2. The weather strip for automobiles according to claim 1.   The automobile weather strip according to claim 1, wherein the seal portion has a hollow shape.   The automobile weather strip according to claim 2 or 3, wherein an outer surface of the seal portion and the cover lip is coated with a solid material.

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