JP2008044572A - Door weather strip and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a door weather strip and a manufacturing method thereof capable of enhancing stiffness by forming a skin layer and of appropriately delimiting a range forming the skin layer. <P>SOLUTION: An extrusion-molding portion 6 forming the door weather strip 3 includes a hollow-like seal portion 12 integrally formed with a mounting base 11 attached to a door edge portion and a seal lip 13, with a dogleg-shaped cross section, extending outside a vehicle from the base portion of the seal portion 12. Among unvulcanized and solid intermediate moldings extrusion-molded on a sectional form as described above, a processing fluid including single sulfur and/or a sulfur compound is coated at least on the bending portion 15 of the seal lip 13 to pass the intermediate molding through a heating zone so as to be vulcanized and foamed, thereby obtaining the extrusion-molding portion 6 with a sponge layer and a skin layer 21. The skin layer 21 formed at least on the bending portion 15 of the seal lip 13 is harder than the sponge layer with a thickness of 0.04-0.15 mm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a door weather strip attached to a peripheral edge of a vehicle door and a method for manufacturing the door weather strip.

  Conventionally, a door weather strip is attached to the peripheral edge of a door of a vehicle such as an automobile. The door weather strip includes a mounting base portion that is attached to a mounting portion (sash portion) provided on the peripheral edge of the door, a seal portion that is integrally formed with the mounting base portion, and has a hollow portion and a base portion of the hollow seal portion. And a seal lip extending to the outside of the vehicle. When the door is closed, the seal portion and the seal lip of the door weather strip are pressed against the peripheral edge of the door opening of the automobile body, thereby sealing between the door and the automobile body.

  The door weather strip is formed of a synthetic rubber having excellent weather resistance, such as EPDM (ethylene-propylene-diene copolymer). Most of the door weather strip is made of the above-described rubber material and includes an extruded portion formed by a known extrusion method. Said extrusion molding part is obtained by vulcanizing the intermediate molded body extruded in an unvulcanized state from an extruder.

  By the way, the hollow seal portion and the seal lip of the door weather strip are deformed when the door is closed to ensure the sealing performance. For this reason, it is desirable that they have a hardness that is easily deformable, but if the seal lip is too soft, there is a risk that it will flutter when the vehicle is running and generate abnormal noise.

  For this reason, conventionally, the seal lip is made thicker or the surface layer part of the seal lip or seal lip is harder than the seal part (for example, the seal part is sponge rubber and the surface part of the seal lip or seal lip is solid rubber). Attempts have been made to make the seal lip have an appropriate hardness. However, even if the seal lip is made thick, there are cases where the seal lip cannot be made thick due to restrictions on the size and shape depending on the positional relationship between the sash portion and the peripheral edge of the door opening.

  Moreover, when different materials are used for the seal lip or the surface layer portion of the seal lip and the seal portion, there is a risk that the extruder for forming the extrusion-molded portion becomes complicated and large. Furthermore, when the entire seal lip is made of solid rubber, the rigidity of the seal lip becomes too high, and the door closing force (force required for closing the door) may be increased. Further, as described above, regarding the seal lip having a limited thickness, it is practically difficult to form a thin solid layer made of solid rubber at the surface layer portion by extrusion molding.

In forming a weather strip (extruded part) having a sponge rubber part, an electron beam is irradiated to an unvulcanized / unfoamed intermediate molded body (for example, one surface of a seal lip), and the surface layer is There is a technique of crosslinking without foaming, and then vulcanizing and foaming the remaining part (for example, see Patent Document 1). By employing this technique, a skin layer harder than the other sponge rubber portions can be formed on the surface layer portion of the sponge rubber portion, and the rigidity of the sponge rubber portion can be increased.
Japanese Patent Laid-Open No. 10-52867

  However, in the technique described in Patent Document 1, even if an attempt is made to irradiate an electron beam only on a predetermined part by masking the area excluding the predetermined part in order to form a skin layer only on a predetermined part of the sponge rubber part, There is a possibility that not only a predetermined part but also a part masked such as the peripheral part thereof may be cross-linked. That is, it is difficult to appropriately define the range in which the skin layer is formed, and there is a possibility that the skin layer may be formed even at a site that does not require the skin layer. For this reason, there exists a possibility of causing the malfunction etc. that the seal lip does not become the expected hardness. Moreover, since an apparatus for irradiating an electron beam is required, there is a concern that the equipment cost will increase significantly.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to increase rigidity by forming a skin layer harder than other parts at a part where rigidity is desired to be increased, and to improve the rigidity of the skin layer. An object of the present invention is to provide a door weather strip that can appropriately define a range to be formed and a method of manufacturing the door weather strip.

  In the following, each means suitable for solving the above-mentioned purpose will be described in terms of items. In addition, the effect etc. peculiar to the means to respond | correspond as needed are added.

Means 1. An attachment base portion that is attached along the peripheral edge of the door of the vehicle, a hollow seal portion that is formed integrally with the attachment base portion, and a door of the vehicle main body when the door is closed from the vicinity of the root portion on the vehicle outer side of the seal portion. In a door weather strip comprising a seal lip extending toward the peripheral edge of the opening, the mounting base portion, the seal portion, and an extruded portion in which the seal lip is formed by extrusion,
The seal lip has a bent portion at an intermediate portion thereof, and is configured in a substantially square shape in which a portion on the front end side is bent outward of the vehicle,
The extruded portion is formed as a sponge layer and a surface layer on the vehicle outer side and vehicle inner side of the tip side portion including at least the bent portion of the seal lip, is harder than the sponge layer, and has a thickness of 0.04 mm or more. A door weather strip comprising a skin layer of 0.15 mm or less.

  According to the means 1, by forming a skin layer having a thickness of 0.04 mm or more and 0.15 mm or less on the surface portion of the bent portion of the seal lip, the seal lip is stretched when the door is closed, and the door is closed. The rigidity of the seal lip can be increased while suppressing the fear that a relatively large force is required when possible. Therefore, the door can be closed relatively smoothly, and the possibility that abnormal noise may be generated due to flapping of the seal lip when the vehicle is running can be prevented.

  Note that when the thickness of the skin layer is less than 0.04 mm, the seal lip may flutter when the vehicle is running, or the sealing performance may be deteriorated. Further, when the thickness of the skin layer exceeds 0.15 mm, the thickness of the skin layer formed on the outside surface and the inside surface of the seal lip exceeds 0.3 mm. For this reason, in the seal lip having an average thickness of 1.0 to 1.4 mm, the ratio of the thickness occupied by the skin layer (solid portion) in the portion where the skin layer is formed (for example, the bent portion) is 1. / 4 to 1/3. As a result, the rigidity of the seal lip becomes too high, and there is a possibility that a relatively large force may be required when the seal lip is stretched to close the door when the door is closed, which is not desirable.

  Further, since the skin layer harder than the sponge layer is provided on the surface layer of the seal lip, surface irregularities due to foaming are suppressed, and a flat surface (surface roughness 10 to 30 μm (Rz)) is formed. For this reason, on the outer surface of the seal lip, the flat surface improves the quality of the appearance, and on the inner surface of the vehicle, the contact surface with the body becomes flat, so that the door is closed by sliding smoothly. . Furthermore, since it is a flat surface, the silicone coating surface or the like as a sliding layer applied thereon is also a flat surface, and the door closing force can be reduced.

  Mean 2. The door weather strip according to means 1, wherein a skin layer having a thickness equivalent to the skin layer formed on the surface layer of the seal lip is also formed on a surface layer portion of the mounting base.

  According to the means 2, the rigidity of the attachment base can be increased by forming the skin layer on the surface layer portion of the attachment base. Therefore, the attachment state of the door weather strip with respect to the attachment part provided along the door peripheral part of a vehicle can be stabilized.

  Moreover, the surface becomes a smooth surface by forming a skin layer on the surface layer portion of the attachment base attached to the attachment portion. For this reason, compared with the case where the surface of an attachment base is comprised with a sponge layer, while being easy to insert an attachment base in an attachment part, surface damage can be prevented and durability can be improved.

  Means 3. The door weather strip according to means 2, wherein the skin layer is not formed at an intermediate portion in the vehicle width direction of the bottom surface of the mounting base.

  According to the means 3, the skin layer is not formed at an intermediate portion (a portion corresponding to the seal portion) in the vehicle width direction in the bottom surface of the attachment base portion. For this reason, it is possible to attach the attachment base portion to the attachment portion provided along the periphery of the door of the vehicle while bending the intermediate portion, and as a result, the rigidity of the attachment base portion is increased, resulting in the door weather strip. It is possible to prevent the possibility that the assembly workability of the machine will deteriorate.

Means 4. A method of manufacturing a door weather strip according to any one of the above means 1 to 3,
When forming the extruded part,
An extrusion process in which unvulcanized unfoamed rubber is extruded;
Of the unvulcanized and unfoamed intermediate molded body formed by the extrusion process, for the part set to form the skin layer, simple sulfur, sulfur compound, or both simple sulfur and sulfur compound An application process in which a treatment liquid containing is applied,
The intermediate molded body to which the treatment liquid has been applied in the application step passes through a heating zone, whereby the surface to which the treatment liquid has been applied is heated and vulcanized to form the non-foamed skin layer. And a vulcanizing and foaming step in which the sponge layer is formed by vulcanizing and foaming unvulcanized unfoamed rubber inside the skin layer.

  According to the means 4, after the extrusion process and before the vulcanization and foaming process, the single part of the uncured and unfoamed intermediate molded body is set so that the skin layer is formed. A treatment liquid containing sulfur, a sulfur compound, or both elemental sulfur and a sulfur compound is applied. Therefore, since the sulfur concentration of the surface layer portion of the portion where the treatment liquid is applied becomes higher than other portions, the crosslinking reaction of the surface portion of the portion where the treatment liquid is applied in the subsequent vulcanization foaming process It will be promoted more than this part. For this reason, first, the surface coated with the treatment liquid is heated and vulcanized to form a skin layer, and then the inside of the skin layer is vulcanized and foamed to form a sponge layer. Further, regarding the surface layer portion where the treatment liquid is applied, foaming is suppressed as the crosslinking reaction is promoted. By these actions, a skin layer harder than the other part (sponge layer) is formed on the surface layer part of the part where the treatment liquid is applied in the vulcanized and foamed intermediate molded body. Therefore, the rigidity of the part can be reliably increased by applying the treatment liquid to the part where the rigidity is desired to be increased in the application process.

  Further, according to this means, a skin layer having a predetermined thickness is formed on the surface layer portion of the portion where the treatment liquid is applied. In other words, a skin layer having a predetermined thickness is not formed at a portion where the treatment liquid is not applied. For this reason, the boundary part of the site | part which forms the skin layer of predetermined thickness, and the site | part which does not form the skin layer of predetermined thickness can be defined reliably. Therefore, it is possible to prevent a skin layer having a predetermined thickness from being formed in a portion that does not require a skin layer having a predetermined thickness, that is, a portion where the rigidity is not desired to be increased, and the rigidity becomes too high. Inconveniences (increased door closing force) due to the above can be avoided. As a result, the hardness of each part of the door weather strip can be set to an intended hardness as designed.

  In addition, the thickness of the seal lip does not change greatly depending on whether or not the treatment liquid is applied to the bent portion of the seal lip. For this reason, for example, it is possible to avoid problems such as the door not closing when there is a variation in the installation of the door due to the thick seal lip, and the design change of the mounting portion etc. The door weather strip can be securely attached to the conventional attachment portion without performing the above. Moreover, the thickness of the skin layer can be made thin and uniform by forming the skin layer by applying a treatment liquid to promote the crosslinking reaction. Therefore, it is possible to prevent problems caused by variations in the thickness of the skin layer. Furthermore, since at least the extrusion molding part can be molded by extruding a single material from an extruder, for example, compared to the case where the material used is different in the surface layer part of the seal lip and other parts. Further, it is possible to avoid the risk that the extrusion molding machine for molding the extrusion molding part becomes complicated and large. In addition, for example, an increase in equipment cost can be suppressed as compared with a case where a skin layer is formed by irradiating a predetermined site with an electron beam.

Means 5. The coating process includes
Spraying means for spraying the treatment liquid toward a portion of the intermediate molded body that is set so that at least the skin layer is formed;
Manufacture of a door weather strip according to means 4, characterized in that it is carried out using masking means for covering a part of the intermediate molded body other than the part where the skin layer is set to be formed. Method.

  According to the means 5, the processing liquid is applied to the intermediate molded body by spraying the processing liquid from the spraying means. For this reason, the treatment liquid can be uniformly applied almost uniformly to a portion of the intermediate molded body where the skin layer is set to be formed, and the skin layer can be reliably formed. Furthermore, due to the presence of the masking means, the treatment liquid sprayed from the spraying means is a part other than the part of the intermediate molded body where the skin layer is set (a skin layer having a predetermined thickness is not required). It is possible to reliably prevent the possibility of being applied to the part).

  Means 6. The masking means is a wall portion that is located between a portion of the intermediate molded body other than the portion that is set so that the skin layer is formed and the spraying means, and blocks between the two. A method of manufacturing a door weather strip according to the means 5 characterized by the above.

  For example, an adhesive tape or the like is used as a masking means, and the adhesive tape or the like is applied to a portion of the intermediate molded body that does not require a skin layer, and the adhesive tape or the like is peeled off after the treatment liquid is applied to the intermediate molded body. When the method is employed, a process of applying an adhesive tape or the like and a process of removing the adhesive tape are required, which may cause a decrease in productivity. In this respect, according to the means 6, since such a process is not required, it is possible to prevent a possibility that workability is deteriorated.

  Hereinafter, an embodiment will be described with reference to the drawings. As shown in FIG. 1, an automobile 1 as a vehicle is provided with an automobile door (in the figure, a front door: hereinafter simply referred to as “door 2”) that can be opened and closed. The door weather strip 3 is attached. An opening trim 4 is attached to the peripheral edge of the door opening of the automobile body (vehicle body) corresponding to the door 2.

  As shown in FIG. 2, the door weather strip 3 includes extrusion molding portions 6 and 7 disposed on the vertical side portion and the horizontal side portion of the door 2, and a mold forming portion disposed on the corner portion of the door 2. (Parts with a dotted pattern in the figure) 8 and 9 are provided. The extrusion molding parts 6 and 7 are formed in an elongated shape by an extrusion molding machine. Further, the mold forming portions 8 and 9 are formed by a predetermined mold apparatus so as to connect the end portions of the adjacent extrusion forming portions 6 and 7. In the present embodiment, the door weather strip 3 is basically composed of foamed EPDM (ethylene-propylene-diene copolymer rubber).

  As shown in FIG. 3, the extrusion molding portion 6 includes an attachment base portion 11 fitted to the outer periphery (retainer portion) of the sash portion DS as an attachment portion provided along the outer periphery of the door 2, and the attachment base portion 11. And extending from the vicinity of the root of the hollow seal portion 12 on the vehicle exterior side toward the peripheral edge of the door opening when the door 2 is closed. And a sealing lip 13 to be taken out. Then, when the door 2 is closed, the seal portion 12 and the seal lip 13 are deformed by abutting against or pressing against the door opening peripheral portion of the automobile body, thereby sealing between the automobile body and the door 2. It has become. Further, in the present embodiment, a lip portion 14 that protrudes outward (outside of the vehicle) from the root portion of the seal lip 13 is provided. The lip portion 14 is configured such that the tip end side thereof is in contact with or pressed against a sash portion DS (a portion extending in the outer peripheral direction of the door 2 on the vehicle outer side). In addition, the extrusion molding part 7 and the molding parts 8 and 9 are also provided with an attachment base 11, a hollow seal part 12, and the like, similarly to the extrusion molding part 6. However, the sealing part 13 is not provided in the extrusion molding part 7.

  The seal lip 13 has a bent portion 15 at an intermediate portion thereof, and is configured in a substantially square shape in which a portion on the front end side is bent toward the outside of the vehicle. The seal lip 13 is deformed so as to be folded in two at the bent portion 15 when the seal lip 13 is brought into pressure contact with the peripheral edge of the door opening of the automobile body at the tip portion thereof. For this reason, the seal lip 13 and the door opening periphery of the automobile body can be more reliably brought into pressure contact with each other, and the sealing performance can be improved. The thickness of the seal lip 13 may be slightly different depending on the part, but is about 1.4 mm on average.

  In the present embodiment, a skin layer 21 that is harder and more rigid than other portions (for example, a sponge-like interior) is formed on the surface layer portions of the mounting base 11 and the seal lip 13. With respect to the seal lip 13, the skin layer 21 is formed on the surface layer portions of the seal lip 13 on both the outside and inside of the vehicle including the bent portion 15. A skin layer 21 is formed from the front end portion of the seal lip 13 to a position slightly closer to the root of the seal lip 13 than the bent portion 15 in the vicinity of the connecting portion with the lip portion 14. Thus, by providing the skin layer 21 that is harder than the sponge layer on the surface layer of the seal lip 13, surface irregularities due to foaming are suppressed, and a flat surface (surface roughness 10 to 30 μm (Rz)) is formed. The Therefore, the quality of the appearance is improved by the flat surface on the outer surface of the seal lip 13, and the contact surface with the automobile body becomes flat on the inner surface of the vehicle, so that the door 2 can slide smoothly. Closed. Furthermore, since it is a flat surface, the silicone coating surface or the like as a sliding layer applied thereon is also a flat surface, and the door closing force can be reliably reduced.

  On the other hand, the skin layer 21 is not formed on the surface layer portions of the seal portion 12 and the lip portion 14. Further, with respect to the attachment base 11, the skin layer 21 is not formed at an intermediate portion in the vehicle width direction (left-right direction in FIG. 3) of the bottom surface, and the skin layer 21 formed corresponding to the attachment base 11. Is divided into a vehicle outer portion and a vehicle inner portion. The thickness of the skin layer 21 is almost uniform in any part, and is set between 40 μm and 150 μm in this embodiment.

  In this embodiment, when a test piece of the extruded portion 6 having a length of 100 mm is prepared in the longitudinal direction, the load required when the seal lip 13 of the test piece at the regular position is bent by 3 mm in the contact direction with the peripheral edge of the door opening. Is set to 0.7 N or more and 2.5 N or less (0.7 N / 100 mm to 2.5 N / 100 mm). Further, the load required when the seal portion 12 and the seal lip 13 of the test piece are simultaneously bent by 3 mm in the contact direction with the door opening peripheral portion is set to about 6.0 N. Incidentally, when the skin layer 21 was not formed on the seal lip, the load required when the seal lip of the test piece was bent 3 mm in the contact direction with the peripheral edge of the door opening was about 0.6 N.

  In the present embodiment, the portion other than the skin layer 21 in the extruded portion 6 constitutes a sponge layer. In the extrusion molded part 7, the skin layer 21 is formed on the surface layer part of the attachment base part 11 excluding the intermediate part on the bottom surface.

  Next, a method for manufacturing the door weather strip 3 will be described. First, the manufacturing process of the extrusion-molded body to be the extrusion-molded parts 6 and 7 will be described. FIG. 4 is a schematic view showing a part of the production line of the extrusion-molded body 41, and the workpiece to be the extrusion-molded body 41 is manufactured while proceeding from the left side to the right side in this figure.

  First, in the extrusion process, unvulcanized and unfoamed EPDM is continuously supplied to the extruder 31. Then, the intermediate molded body 40 having a predetermined cross-sectional shape is extruded from the die of the extrusion molding machine 31. The unvulcanized and unfoamed EPDM contains simple sulfur, a sulfur compound, or both simple sulfur and a sulfur compound as a crosslinking agent, and also contains a foaming material such as sodium bicarbonate.

  Subsequent to the extrusion step, the extruded intermediate molded body 40 is guided to the surface treatment tank 32, and single sulfur, a sulfur compound, or a single piece is applied to the portion of the mounting base 11 excluding the intermediate portion on the bottom surface and the seal lip 13. An application step of applying a sulfur dispersion for crosslinking as a treatment liquid containing both sulfur and a sulfur compound is performed. In this embodiment, in 100% by weight of the sulfur dispersion for crosslinking, 1 to 50% by weight of elemental sulfur and / or a sulfur compound, 0.01 to 25% by weight of a surfactant as a dispersant, and stability such as polyvinyl alcohol The agent is contained in an amount of 0 to 1% by weight, and a dispersion medium such as water is contained in an amount of 24 to 99.99% by weight. As for the elemental sulfur and the sulfur compound, it is desirable to use only particles that can pass through a sieve of usually 300 mesh, preferably 500 mesh. The dispersion medium is not particularly limited as long as it does not react with the elemental sulfur, the sulfur compound, and the unvulcanized rubber to be crosslinked, and can dissolve or disperse the dispersant or stabilizer.

  Inside the surface treatment tank 32, as shown in FIG. 5, a spraying device having a plurality of nozzles 51 for spraying the sulfur dispersion for crosslinking, and a sulfur dispersion for crosslinking sprayed from the nozzles 51, Between the portion 51 and the nozzle 51 so as not to adhere to a portion of the intermediate molded body 40 that does not require the skin layer 21 (in this example, the intermediate portion of the bottom surface of the seal portion 12, the lip portion 14, and the mounting base 11). And a blocking wall portion 52 for blocking. And while the intermediate molded body 40 passes through the surface treatment tank 32, the portion that is not masked by the blocking wall portion 52, that is, the portion other than the intermediate portion on the bottom surface of the mounting base 11 and the seal lip 13, The sulfur dispersion for crosslinking sprayed from the nozzle 51 is applied. The sulfur dispersion for crosslinking applied to the surface of the intermediate molded body 40 penetrates slightly into the intermediate molded body 40, thereby increasing the sulfur concentration at the surface layer portion where the sulfur dispersion for crosslinking is applied. In the present embodiment, the spraying device including the plurality of nozzles 51 constitutes the spraying means, and the blocking wall portion 52 constitutes the masking means.

  In the subsequent crosslinking / foaming step, the intermediate molded body 40 is guided to the high-frequency vulcanization tank (UHF) 33 and the hot air vulcanization tank (HAV) 34, and vulcanization / foaming is performed.

  In the present embodiment, in the application step, the surface portion of the attachment base 11 (excluding the intermediate portion on the bottom surface) and the surface of the seal lip 13 is coated with the crosslinking sulfur dispersion and the crosslinking sulfur dispersion is applied. In regard to, the sulfur concentration is higher than other parts. For this reason, in the said vulcanization | cure and foaming process, the crosslinking reaction of the surface layer site | part of the site | part to which the sulfur dispersion for bridge | crosslinking was apply | coated is accelerated | stimulated rather than another site | part. For this reason, first, the surface layer portion where the crosslinking sulfur dispersion is applied is heated and vulcanized to form the skin layer 21, and then the inside of the skin layer 21 is vulcanized and foamed to form the sponge layer. Is done. Further, with respect to the surface layer portion where the crosslinking sulfur dispersion is applied, foaming is suppressed as the crosslinking reaction is promoted. By these actions, the surface layer portion excluding the bottom surface intermediate portion of the attachment base portion 11 of the vulcanized and foamed intermediate molded body 40 and the surface layer portion including the bent portion 15 of the seal lip 13 are more than the other portions. A hard skin layer 21 is formed.

  Thereafter, the intermediate molded body 40 is cut into a predetermined dimension by the cutter 35 to become an extruded molded body 41.

  In the mold forming step, the extrusion molded bodies 41 corresponding to the extrusion molding sections 6 and 7 are set in a mold apparatus (not shown), and the mold molding sections 8 and 9 are connected and molded. More specifically, uncrosslinked EPDM is injected into the cavity from a state in which the mold apparatus is clamped and filled. Thereafter, the EPDM is cross-linked, the mold apparatus is opened, and the door weather strip 3 is obtained.

  In addition, the thickness of the skin layer 21 may be controlled by changing the application amount (application time) of the crosslinking sulfur dispersion sprayed from the nozzle 51 or increasing the sulfur concentration of the crosslinking sulfur dispersion. Is possible. In addition, the extrusion-molded body 41 has an amount of sulfur present on the surface thereof that is 1.2 times or more of the amount of sulfur present on the cutting surface obtained when cutting from the surface to a depth of 1 mm in the vertical direction. 10 times or less.

  As described above in detail, in this embodiment, after the extrusion process and before the crosslinking / foaming process, the sulfur for crosslinking is applied to the seal lip 13 and the part of the mounting base 11 excluding the intermediate part on the bottom surface. By applying the dispersion liquid, a skin layer 21 that is harder than other portions (sponge layer) is formed on the surface layer portion. In this embodiment, when a test piece of the extruded portion 6 having a thickness of 100 mm in the longitudinal direction is prepared by forming a skin layer 21 having a thickness of 40 μm to 150 μm on the surface layer portion of the seal lip 13, the seal of the test piece is provided. The load required when the lip 13 is bent 3 mm in the contact direction with the door opening peripheral edge is set to 0.7 N or more and 2.5 N or less. By setting the hardness of the seal lip 13 in this way, the risk that the seal lip 13 may be stretched when the door 2 is closed and a relatively large force is required when the door 2 is completely closed is suppressed. Meanwhile, the rigidity of the seal lip 13 can be increased. Accordingly, the door 2 can be closed relatively smoothly, and the possibility that the noise is generated due to the seal lip 13 flapping when the automobile 1 is traveling can be prevented.

  Further, the skin layer 21 is formed on the surface layer portion of the attachment base portion 11, whereby the rigidity of the attachment base portion 11 can be increased, and the attachment state of the door weather strip 3 to the sash portion DS can be stabilized. . In addition, the surface of the attachment base 11 becomes a smooth surface by forming the skin layer 21 on the surface layer portion of the attachment base 11. For this reason, for example, it becomes easier to insert the attachment base 11 into the sash portion DS than when the surface layer portion of the attachment base 11 is formed of a sponge layer, and the surface is damaged (for example, damage at the time of insertion). Can be prevented, and durability can be improved.

  Furthermore, according to this embodiment, the skin layer 21 is formed in the surface layer part of the site | part which apply | coated the sulfur dispersion liquid for bridge | crosslinking. In other words, the skin layer 21 is not formed at a site where the crosslinking sulfur dispersion is not applied. For this reason, the boundary part of the site | part which forms the skin layer 21 and the site | part which does not form the skin layer 21 can be defined reliably. Therefore, it is possible to avoid a problem caused by the formation of the skin layer 21 even in a portion where the skin layer 21 is not required, that is, a portion where it is not desired to increase the rigidity. As a result, the hardness of each part of the door weather strip 3 can be set to an intended hardness as designed. In this embodiment, the sulfur dispersion for crosslinking is not applied to the seal portion 12 and the lip portion 14. This avoids the possibility that the skin layer 21 is formed on the seal portion 12 and the lip portion 14 to reduce the flexibility and the sealing performance.

  In addition, when a test piece of the extrusion molded part 6 having a length of 100 mm is prepared in the longitudinal direction, the load required when the seal part 12 and the seal lip 13 of the test piece are simultaneously bent by 3 mm in the contact direction with the door opening peripheral part. It is set to about 6.0N. That is, when the elastic force of one of the seal part 12 and the seal lip 13 is increased, the balance as a whole is maintained by decreasing the elastic force of the other. Thereby, when the door 2 is closed, the seal portion 12 and the seal lip 13 are stretched, and a risk that a relatively large force is required when the door 2 is completely closed is suppressed. In this embodiment, the balance is maintained by forming the skin layer 21 on the surface layer portion of the seal lip 13 and not forming the skin layer 21 on the seal portion 12 or by reducing the thickness thereof.

  In addition, the intermediate portion of the bottom surface of the mounting base portion 11 is excluded depending on whether or not the sulfur dispersion for crosslinking is applied to the portion other than the intermediate portion of the bottom surface of the mounting base portion 11 and the seal lip 13. The thickness of the part and the seal lip 13 does not change greatly. For this reason, for example, it is possible to avoid problems such as the door 2 not being closed when the installation variation of the door 2 occurs due to the thick seal lip, such as the sash portion DS. The door weather strip 3 can be securely attached to the conventional sash portion DS without changing the design or the like.

  Moreover, the thickness of the skin layer 21 can be made thin and uniform by forming the skin layer 21 by applying a sulfur dispersion for crosslinking to promote the crosslinking reaction. Therefore, it is possible to prevent problems caused by variations in the thickness of the skin layer 21. Furthermore, since the extrusion molding parts 6 and 7 can be molded by extruding a single material from the extrusion machine 31, the material used depends on the part (for example, with a seal lip and a hollow seal part). Compared to different cases, it is possible to avoid the risk that the extrusion molding machine for molding the extrusion molding parts 6 and 7 becomes complicated and large. In addition, for example, an increase in equipment cost can be suppressed as compared with a case where a skin layer is formed by irradiating the mounting base and the seal lip with an electron beam.

  Further, in the present embodiment, the sulfur dispersion for crosslinking is not applied to the intermediate portion in the vehicle width direction among the bottom surface of the mounting base portion 11. For this reason, the skin layer 21 is not formed in the intermediate part in the vehicle width direction of the bottom surface of the attachment base 11 (a skin layer having a thickness of at least 40 μm to 150 μm is not formed). For this reason, the attachment base 11 can be attached to the sash portion DS while being bent at the intermediate portion. As a result, the assembly workability of the door weather strip 3 is lowered due to the increased rigidity of the attachment base 11. It is possible to prevent such a risk that it will occur.

  In addition, the crosslinking sulfur dispersion is applied to the intermediate molded body 40 by spraying the crosslinking sulfur dispersion from the nozzle 51. For this reason, the sulfur dispersion for crosslinking can be uniformly applied almost uniformly to the portion of the mounting base 11 excluding the intermediate portion on the bottom surface and the seal lip 13, and the skin layer 21 can be reliably formed. . Further, the presence of the blocking wall 52 can prevent the crosslinking sulfur dispersion from being applied (attached) to a portion of the intermediate molded body 40 that does not require the skin layer 21.

  In addition, for example, a method is adopted in which masking is performed by applying an adhesive tape or the like to a portion of the intermediate molded body 40 that does not require the skin layer 21, and the adhesive tape or the like is peeled off after the sulfur dispersion for crosslinking is applied. When doing, the process of sticking an adhesive tape etc. and the process of peeling are needed, and there exists a possibility of causing the fall of productivity. Furthermore, when sticking an adhesive tape or the like, it is an operation within a short section (within a period) between the extrusion process and the coating process for applying the crosslinking sulfur dispersion, and the adhesive tape or the like is peeled off. This is an operation in a short section (within the period) between the coating process and the cross-linking / foaming process, which is difficult in a continuous production line. In this respect, according to the present embodiment, since such a process is not required, it is possible to prevent a possibility that workability is deteriorated.

  In addition, it is not limited to the description content of the said embodiment, For example, you may implement as follows. Of course, other application examples and modification examples not illustrated below are also possible.

  (A) In the above embodiment, the door weather strip 3 of the front door is embodied, but the portion of the door to be attached is not limited in any way, and for example, the door weather strip is applied to a rear door. You can also

  (B) In the above embodiment, the sulfur dispersion for crosslinking sprayed from the nozzle 51 does not require the skin layer 21 in the intermediate molded body 40 (the bottom surface of the seal portion 12, the lip portion 14, and the mounting base portion 11. The intermediate wall is masked by providing a blocking wall portion 52 that blocks between the part and the nozzle 51, but is not particularly limited to such a configuration. For example, a method is adopted in which masking is performed by applying an adhesive tape or the like to a portion of the intermediate molded body 40 that does not require the skin layer 21, and the adhesive tape or the like is removed after applying the sulfur dispersion for crosslinking. Also good. However, in this case, a process of attaching an adhesive tape or the like to the mounting base 11 and the seal lip 13 and a process of removing the adhesive tape are required, which may cause a decrease in productivity. Therefore, as in the above-described embodiment, it is desirable to perform masking with a wall portion (blocking wall portion 52) that is located between a portion that does not require the skin layer 21 and the nozzle 51 and blocks between the two.

  (C) In the above embodiment, the sulfur dispersion for crosslinking is applied to the intermediate molded body 40 by spraying the sulfur dispersion for crosslinking from the nozzle 51. For example, the intermediate molded body 40 is applied to the intermediate molded body 40 with a brush or a roller. A sulfur dispersion for crosslinking may be applied. However, since the intermediate molded body 40 is unvulcanized and its shape is not stable, non-contact spray coating is preferred as in the above embodiment.

  In FIG. 5, the sulfur dispersion for crosslinking is performed at once on all the portions of the intermediate molded body 40 where the skin layer 21 is to be formed (the portions of the mounting base 11 excluding the intermediate portion on the bottom surface and the seal lip 13). Although the liquid is sprayed, the plurality of nozzles 51 may be shifted in the transfer direction of the intermediate molded body 40 so that the droplets sprayed from the plurality of nozzles 51 do not buffer each other. . For example, the surface treatment tank 32 applies the treatment liquid to the zone in which the treatment liquid is applied to the bottom surface of the attachment base 11, the surface and the side part of the attachment base 11 on the seal part 12 side, and the outer surface of the seal lip 13. It is good also as a structure which comprises the zone to apply | coat, and the zone which apply | coats a process liquid to the surface at the side of the seal part 12 of the seal lip 13. FIG. In addition, the blocking wall portion 52 is appropriately disposed in accordance with the arrangement of the nozzles 51.

  (D) In the above embodiment, the door weather strip 3 is made of foamed EPDM, but may be made of other foamed rubber.

  (E) In the above-described embodiment, the skin layer 21 is formed on the attachment base portion 11 except for the intermediate portion on the bottom surface and the surface layer portion of the seal lip 13, but the skin layer 21 is not particularly limited to such a configuration. Instead, it is only necessary that the skin layer 21 is formed on at least the surface layer portion of the bent portion 15 (the surface layer portion on the vehicle outer surface and the vehicle inner surface) of the seal lip 13. For example, the crosslinking sulfur dispersion may be applied to the entire bottom surface of the mounting base 11, and the skin layer 21 may be formed on the entire surface portion of the mounting base 11, or the crosslinking sulfur dispersion may be applied to the mounting base 11. Alternatively, the attachment base 11 may be configured such that the skin layer 21 is not formed. In addition, by forming the skin layer 21 on both sides of the outer surface and the inner surface of the seal lip 13, for example, only one of the outer surface and the inner surface of the seal lip 13 is skinned. Compared with the case where the layer 21 is formed, the deformation mode of the seal lip 13 can be stabilized.

  Further, in order to improve the appearance quality, the crosslinking sulfur dispersion is thinly applied to other parts such as the seal part 12, and the skin layer 21 formed on the surface part of the mounting base part 11 and the seal lip 13. A thin skin layer may also be formed.

It is a perspective view of a car with a front door in an open state. It is a front view which shows a door weather strip. It is the JJ sectional view taken on the line of FIG. 2 which shows a door weather strip. It is a schematic diagram which shows a part of manufacturing line of an extrusion molded object. It is a schematic cross section which shows the internal structure of a surface treatment tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Automobile, 2 ... Door, 3 ... Door weather strip, 4 ... Opening trim, 6, 7 ... Extrusion part, 8, 9 ... Molding part, 11 ... Mounting base, 12 ... Seal part, 13 ... Seal lip , 15 ... bending part, 21 ... skin layer, 32 ... surface treatment tank, 40 ... intermediate molding, 41 ... extrusion molding, 51 ... nozzle, 52 ... blocking wall part, DS ... sash part.

Claims (6)

An attachment base portion that is attached along the peripheral edge of the door of the vehicle, a hollow seal portion that is formed integrally with the attachment base portion, and a door of the vehicle main body when the door is closed from the vicinity of the root portion on the vehicle outer side of the seal portion. In a door weather strip comprising a seal lip extending toward the peripheral edge of the opening, the mounting base portion, the seal portion, and an extruded portion in which the seal lip is formed by extrusion,
The seal lip has a bent portion at an intermediate portion thereof, and is configured in a substantially square shape in which a portion on the front end side is bent outward of the vehicle,
The extruded part is:
Sponge layer,
At least the seal lip is formed as a surface layer on the vehicle outer side and vehicle inner side of the tip side portion including the bent portion, and includes a skin layer that is harder than the sponge layer and has a thickness of 0.04 mm or more and 0.15 mm or less. A door weather strip.   The door weather strip according to claim 1, wherein a skin layer having a thickness equivalent to that of the skin layer formed on a surface layer of the seal lip is also formed on a surface layer portion of the attachment base portion.   3. The door weather strip according to claim 2, wherein the skin layer is not formed at an intermediate portion in the vehicle width direction of the bottom surface of the attachment base portion. A door weather strip manufacturing method according to any one of claims 1 to 3,
When forming the extruded part,
An extrusion process in which unvulcanized unfoamed rubber is extruded;
Of the unvulcanized and unfoamed intermediate molded body formed by the extrusion process, for the part set to form the skin layer, simple sulfur, sulfur compound, or both simple sulfur and sulfur compound An application process in which a treatment liquid containing is applied,
The intermediate molded body to which the treatment liquid has been applied in the application step passes through a heating zone, whereby the surface to which the treatment liquid has been applied is heated and vulcanized to form the non-foamed skin layer. And a vulcanizing and foaming step in which the sponge layer is formed by vulcanizing and foaming unvulcanized unfoamed rubber inside the skin layer. The coating process includes
Spraying means for spraying the treatment liquid toward a portion of the intermediate molded body that is set so that at least the skin layer is formed;
5. The door weather strip according to claim 4, wherein the door weather strip is formed using masking means that covers a portion of the intermediate molded body other than the portion that is set to form the skin layer. Production method. The masking means is a wall portion that is located between a portion of the intermediate molded body other than the portion that is set so that the skin layer is formed and the spraying means, and blocks between the two. The door weather strip manufacturing method according to claim 5.

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