Patent Publication Number: US-2005136199-A1

Title: Weather strip

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a weather strip applied to the joints of an automobile door or a roof side, for example.  
      2. Related Art  
      Weather strips are installed around the outer peripheral edges of automobile doors and the like. Heretofore, a weather strip having a hollow seal portion (main seal portion) and a weather strip having a seal lip (sub-seal portion) maybe applied to respective parts corresponding to the upper side of a door. In this case, these two pieces of weather strips have to be produced separately from each other and installed independently of each other.  
      On the other hand, the art of integrating a main seal member having the main seal portion with a sub-seal member having the sub-seal portion by means of a coupling portion has been proposed (see Japanese Patent Publication No. JP-A-2002-307952, for example). With this arrangement, the number of man-hours necessary for the manufacture of weather strips becomes reducible while workability is the made improvable thereby at the time these members are installed.  
      Now, in the aforesaid prior art, not only the main seal member but the sub-seal member normally has a fitting base portion in the form of a substantially flat plate fitted to a retainer. In this case, in view of planning to improve the workability further at the time of installation, it is reasoned that the fitting base portion of the sub-seal member is formed of solid material, for example, with the one side portion securely latched to the retainer while the other side portion (main seal member side) is not securely latched thereto, so that latching the one side portion to the retainer serves as latching the other side portion thereto; that is, the other side portion is dependent on latching of the fitting base portion of the main seal portion made of foamed material to the retainer. Thus, the installation work can be simplified further.  
      When the weather strip is thus configured, however, the difference in foaming rate between the main seal member and the sub-seal member and the difference in expansion rate therebetween may cause a warp to be produced in the weather strip in case both the members are integrally molded. More specifically, the fitting base portion of the sub-seal portion is hard to expand to the extent that the fitting base portion thereof is formed of solid material when the weather strip is extrusion-molded and the main seal member is rather easy to expand. Consequently, the weather strip may warp immediately after the extrusion (at the time of vulcanization and the like), so that the installation workability may be worsened instead.  
     SUMMARY OF THE INVENTION  
      An object of the invention made in view of the circumstances above is to provide a weather strip feasible for reducing the number of man-hours, restraining the generation of a warp and improving installation workability.  
      Each of the means fit for solving the foregoing problems will now be described in due order. Further, operation/working-effect characteristic of the corresponding means will be described in addition as the need arises.  
      Means 1: a weather strip comprises a first seal member having a first fitting base portion and a main seal portion formed integrally with the first fitting base portion, a second seal member having a second fitting base portion and a sub-seal portion formed integrally with the second fitting base portion, a coupling portion for coupling the first seal member and the second seal member, wherein the greater part or the whole part of the second fitting base portion is formed of solid material or fine foaming material; and the main seal portion and the sub-seal portion are formed of foaming material, and is characterized in that at least part of the first fitting base portion is formed of the solid material or the fine foaming material.  
      According to the means 1, the first seal member and the second seal member are coupled via the coupling portion, so that the number of man-hours necessary for the manufacture of them is reducible in comparison with a case where they are separately molded. At the time of installation, moreover, it is less burdensome to install the first seal member and the second seal member in comparison with a case where they are installed independently of each other, whereby an improvement in workability is attempted. The greater part or the whole part of the second fitting base portion is formed of the solid material or the fine foaming material according to the means 1. Consequently, the installed condition as a whole can be maintained with stability by relatively securely installing the first seal member by relatively securely latching one side portion of the second fitting base portion even without securely latching the other side portion on the first seal member side. Therefore, the installation work is greatly simplified by adopting an installation mode like this.  
      According to the means 1, moreover, though the greater part or the whole part of the second fitting base portion is formed of the solid material or the fine foaming material, at least part of the first fitting base portion is also formed of the solid material or the fine foaming material. Hence, unlike the prior art in which the difference in not only foaming rate but expansion rate may cause a warp to be produced, the presence of the solid material or the fine foaming material in the first seal member and the second member both causes the difference in expansion rate to hardly occur. Therefore, it is possible to prevent nonconformity such as a deterioration in installation workability resulting from the generation of the warp and consequently the installation workability can greatly be improved.  
      Further, the foaming material, the solid material and the fine foaming material referred to in the means herein will be described. The foaming material is a relatively soft sponge material; more specifically, it is preferable that the foaming quantity (the volume of foam accounting for a percentage of the total volume) is greater than 25% and that the hardness is less than 65 degrees in the JIS-A type. EPDM (ethylene-diene-propylene copolymer), TPO (olefin thermoplastic elastomer) and so forth, for example, are cited as other raw materials. In the meantime, the sold material and the fine foaming material are relatively hard and have prescribed rigidity to the extent that their own shapes are maintained. More specifically, it is preferable that the solid material and the fine foaming material have a hardness of not less than 65 degrees and not greater than 85 degrees in the JIS-A type and in the case of the fine foaming material, what has a foaming quantity of not greater than 25% is preferable. As raw materials, EPDM, TPO, PP (polypropylene) and so on are enumerated.  
      Means 2: a weather strip comprises a first seal member having a first fitting base portion in the form of a substantially flat plate and a hollow seal portion formed integrally with the first fitting base portion, a second seal member having a second fitting base portion in the form of a substantially flat plate and a seal lip formed integrally with the second fitting base portion, a coupling portion for coupling the first seal member and the second seal member, wherein the greater part or the whole part of the second fitting base portion is formed of solid material or fine foaming material; and the hollow seal portion and the seal lip are formed of foaming material, and is characterized in that at least part of the first fitting base portion is formed of the solid material or the fine foaming material.  
      According to the means 2, though operation/working-effect is basically similar to what has been described as in the case of the means 1, the sealing functions performed by the hollow seal portion and the seal lip are demonstrated with respect to sealing. As both the first fitting base portions are in the form of a substantially flat plate, the merit is that they are easily inserted (fitted) into the depression (e.g., a hook-shaped mating portion) of the fitting means such as retainers.  
      Means 3: a weather strip as described in the means 1 or 2, wherein apart not directly related to installation or sealing out of the first fitting base portion is formed of the solid material or the fine foaming material.  
      According to the means 3, a part not directly related to installation or sealing out of the first fitting base portion is formed of the solid material or the fine foaming material and any other part is formed of the foaming material and relatively easily deformed; when the part is fitted (fitted into the fitting member such as a retainer or fixed to a jig such as a clip, for example), an improvement in workability is offered insecurity, which results in never impeding sealability. In this case, the ‘part not directly related to installation’ means mainly a part not in direct contact with the fitting member or the fitting jig and the ‘part not directly related to sealing’ means mainly a part without contact against an opposing member as an object for sealing.  
      Means 4: a weather strip as described in one of the means 1 to 3, wherein the rate of the cross section of the portion formed of the solid material or the fine foaming material out of the second fitting base portion to the cross section of the portion formed of the solid material or the fine foaming material out of the first fitting base portion is not less than one third and not greater than one.  
      According to the means 4, it is ensured that the warp is hardly produced. In case where the rate of the cross section is less than one third, on the contrary, the effect of preventing the generation of the warp may be demonstrated. In case where the rate of the cross section is greater than one, the installation of the first fitting base portion may be impeded and the first fitting base portion will have to become huge in size. However, the ‘rate of the cross section’ may be set ‘not less than one half and not greater than one’ or ‘not less than two thirds and not greater than one.’ 
      Means 5: a weather strip as described in one of the means 1 to 4, wherein at least both sides of the first fitting base portion are latched to fitting means so as to be fixedly installed; and at least the one side thereof is formed of the foaming material.  
      According to the means 5, with both sides of the first fitting base portion being latched to the fitting means such as a retainer, the first fitting base portion is fixed; in this case, since at least one side portion thereof is formed of the foaming material, it is readily be latched thereto without resistance on latching the other side portion thereto first.  
      Thus, a further improvement in the installation workability can be attempted.  
      Means 6: a weather strip as described in one of the means 1 to 5, wherein a surface region visually confirmable from the outside in an installed condition is formed of the foaming material.  
      In the weather strip according to each of the means above, wherein the foaming material and the solid material or the fine foaming material are intermingled, there develops a problem arising from deteriorating external appearance because of difference in external appearance mode. In view of this, as the surface region visually confirmable from the outside in the installed condition is totally formed of the foaming material according to the means 6, a difference in the external appearance mode hardly occurs, thus resulting in preventing the deterioration of the quality of the external appearance.  
      Means 7: a weather strip as described in one of the means 1 to 6, wherein the coupling portion is formed of the foaming material.  
      A prescribed gap is generally set between the first seal member and the second seal member and as the coupling portion for coupling both of them is formed of the foaming material according to the means 7, so that the coupling portion is excellent in follow-up characteristic as it is relatively easy to elongate.  
      Assuming that a number of installation errors exist in each of the means for installing the first fitting base portion and the second fitting base portion, such errors can be absorbed. Consequently, the installation workability is prevented from being deteriorated and even after the installation, the stabilization of the installed condition can be attempted.  
      Means 8: a weather strip as described in one of means 1 to 4, wherein the first fitting base portion is latched by a clip and the part unaffected by incorporating the clip is formed of the solid material or the fine foaming material.  
      According to the means 8, the first fitting base portion is latched by the clip. Of the first fitting base portion, the part unaffected by incorporating the clip is formed of the solid material or the fine foaming material, whereby the operation/working-effect become effective. Further, the clip is relatively easily fitted as the part affected by incorporating the clip, or the periphery of the part where the insertion of the clip is made is formed of the foaming material. Moreover, the presence of the solid material or the fine foaming material results in increasing rigidity, whereby sealing between the weather strip and an opposing part (e.g., a door frame) is further stabilized. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a sectional view of the principal part of a weather strip taken on line I-I of  FIG. 2  according an embodiment of the invention.  
       FIG. 2  is a schematic elevational view of the schematic configuration of a door weather strip.  
       FIG. 3  is a sectional view of a weather strip according to another embodiment of the invention.  
       FIG. 4  is a sectional view of a weather strip according to still another embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      An embodiment of the invention will now be described by reference to the drawings.  
      Automobiles are provided with open-and-close front doors and a weather strip  1  is installed along the outer periphery of such a front door as shown in  FIG. 2 . The greater part of the weather strip  1  along the longer direction is formed by an extrusion molding portion  2 . Moreover, corner portions (with point patterns in  FIG. 2 ) are formed with die-molded sections  3 .  
      As a portion corresponding to the roof side portion (upper side portion of  FIG. 2 ) out of the extrusion-molded portion  2  has a distinctive feature according to the embodiment of the invention, the construction of the portion in question will be described as follows.  
      As shown in  FIG. 1 , the extrusion-molded portion  2  in the upper side portion has a main seal member  11  as a first seal member, a sub-seal member  21  as a second seal member and a coupling portion  31  for coupling both the seal members  11  and  21 .  
      The main seal member  11  has a substantially flat platelike first fitting base portion  12  fitted to the first retainer  41  of a door frame  40 , and a hollow seal portion  13  formed integrally with the first fitting base portion  12  and protruded in an expanded condition toward the open peripheral edge of a body  42 . The hollow seal portion  13  is formed of EPDM (ethylene-diene-propylene copolymer) sponge rubber.  
      The sub-seal member  21  has a substantially flat platelike second fitting base portion  22  fitted to a second retainer  43  positioned on the outer body side of the first retainer  41 , and a seal lip  23  formed integrally with the second fitting base portion  22  and projected toward the open peripheral edge of the body  42 . Like the seal portion  13  above, the seal lip  23  is formed of EPDM (ethylene-diene-propylene copolymer) sponge rubber. More specifically, the seal lip  23 , the coupling portion  31  and the hollow seal portion  13  are formed of EPDM sponge rubber consecutively by monolithic molding.  
      With the weather strip  1  thus configured, the hollow seal portion  13  and the seal lip  23  come into contact with the open peripheral edge of the body  42  and are deformed when the front door is shut whereby to seal up the gap between the body  42  and the front door (door frame  40 ).  
      In view of planning to improve the workability further at the time of installation, the greater part of the substantially flat platelike second fitting base portion  22  of the sub-seal member  21  is formed of EPDM solid rubber as a solid material according to the embodiment of the invention. Moreover, the one-side (on the outer body side) is made to be inserted into a mating depression in the latching part on the outer body side (in the right upper portion of  FIG. 1 ) of the second retainer  43  and securely latched inside, whereas the side portion on the side of the main seal member  11  is made not to be so securely latched. In other words, since the sub-seal member  21  and the main seal member  11  are monolithically molded via the coupling portion  31  with respect to the other side portion of the second fitting base portion  22  according to the embodiment of the invention, the latching of the door weather strip  1  as a whole is maintained by securely fixing the first fitting base portion  12  of the main seal member  11  to the door frame  40  of the front door. Thus, an attempt to greatly simplify installation work is made.  
      With respect to a region visually confirmable from the outside (mainly the upper portion of  FIG. 1 ) with the weather strip  1  in an installed condition, the greater part is formed of the EPDM sponge rubber. In other words, even in the second fitting base portion  22  mostly formed of the solid rubber, its upper surface layer portion is formed of the EPDM sponge rubber as in the seal lip  23 . Thus, the region visually confirmable from the outside is totally formed of the EPDM sponge rubber, so that it is attempted to prevent the quality of the external appearance from being deteriorated because of a difference in material.  
      Further, though the greater part of the second fitting base portion  22  is formed of the EPDM solid rubber, the central part of the first fitting base portion  12  (the portion shown by SL 1  in  FIG. 1 ) is formed of the EPDM solid rubber as well. The central part is a part that is not directly related to sealing and both its sides, that is, the portion directed related to the latching with respect to the first retainer  41 , are formed of the EPDM sponge rubber. The ratio of the cross section of the portion formed of the solid material out of the first fitting base portion  12  to the cross section of the portion formed of the solid material out of the second fitting base portion  22  is set to not less than one third and not greater than one.  
      As described above in detail, the main seal member  11  and the sub-seal member  21  are integrated via the coupling portion  31  according to the embodiment of the invention, so that the number of man-hours necessary for the manufacture of them is reducible in comparison with a case where they are separately molded. At the time of installation, moreover, it is less burdensome to install the main seal member  11  and the sub-seal member  21  in comparison with a case where they are installed independently of each other, whereby an improvement in workability is attempted.  
      The greater part of the second fitting base portion  22  is formed of the EPDM solid rubber. Consequently, by relatively securely inserting the side portion on the outer body side of the second fitting base portion  22  into the depression of the second retainer  43  without securely latching the other side portion on the side of the main seal member  11 , the main seal member  11  is relatively securely fitted to the first retainer  41 , so that the installed condition of the weather strip as a whole can be maintained with stability. Therefore, the installation work is greatly simplified by adopting an installation mode like this.  
      Although the greater part of the second fitting base portion  22  is formed of the EPDM solid rubber, the central part of the first fitting base portion  12  is also formed of the EPDM solid rubber according to the embodiment of the invention. Hence, unlike the prior art in which the difference in not only foaming rate but expansion rate may cause a warp to be produced, the presence of the solid material in the main seal member  11  and the sub-seal member  21  both causes the difference in expansion rate to hardly occur. Therefore, it is possible to prevent nonconformity such as a deterioration in installation workability resulting from the generation of the warp and consequently the installation workability can greatly be improved.  
      The EPDM solid rubber is especially provided in the central part not directly related to installation as well as sealing out of the first fitting base portion  12  and any portion other than the central part is formed of the EPDM sponge rubber. Therefore, both sides of the first fitting base portion  12  are relatively easily subjected to deformation and can be fitted to the first retainer  41  without any impediment in particular.  
      In the installed condition of the weather strip  1  according to the embodiment of the invention, the region visually confirmable from the outside is totally formed of the EPDM sponge rubber, whereby nonconformity resulting from the lowering of the quality of the external appearance caused by employing different material is made preventable.  
      While the prescribed gap is simultaneously provided between the main seal member  11  and the sub-seal member  21 , the coupling portion  31  for coupling them  11  and  21  is formed of the EPDM sponge rubber according to the embodiment of the invention, so that the coupling portion  31  is excellent in follow-up characteristic as it is relatively easy to elongate. Assuming that a number of installation errors exist in regard to the first retainer  41  and the second retainer  43 , installation can be completed with a sufficient time margin on absorbing such errors. Consequently, it is ensured that the installation workability is prevented from being deteriorated and even after the installation, the stabilization of the installed condition can be attempted.  
      The invention is not limited to what has been described in the embodiment thereof but may be implemented as follows:  
      (a) Although it has been arranged according to the embodiment of the invention that the EPDM solid rubber (SL 1 ) of the first fitting base portion  12  is exposed to the first retainer  41 , EPDM solid rubber (SL 2  in  FIG. 3 ) may be covered with the EPDM sponge rubber as shown in  FIG. 3 , which is also applicable to the second fitting base portion  22  (though not shown). Needless to say, the whole periphery of the weather strip  1  may also be covered with the EPDM sponge rubber.  
      (b) Although the first fitting base portion  12  is installed by fitting the first fitting base portion  12  into the first retainer  41  according to the embodiment of the invention, the first fitting base portion  12  may be fixed by a clip  44  as shown in  FIG. 4 . In this case, EPDM solid rubber (SL 3 ) is preferably provided in a part not in contact with the clip  44 , that is, in a part not directly related to installation (i.e., without affecting installation) as shown in  FIG. 4 . Due to the easy-to-fit clip  44  as well as two pieces of solid rubber consecutively existing on either side of the clip  44 , rigidity in the longer direction is stabilized and sealing between the weather strip and the door frame is ensured by using the clip  44 .  
      (c) The door weather strip  1  fitted to the front door is embodied in the embodiment of the invention, which may also be applied to a door weather strip for use in a rear door. Further, a roof-side weather strip on the body side may be embodied in the embodiment of the invention. Moreover, the invention may be applied to a weather strip for sealing up any other door (e.g., a slide door or a back door).  
      (d) Although the EPDM sponge material is employed as a foaming material according to the embodiment of the invention, any other foaming material may be employed as long as the material quality is relatively soft. More specifically, it is preferable that the foaming quantity (the volume of foam accounting for a percentage of the total volume) is greater than 25% and that the hardness is less than 65 degrees in the JIS-A type. TPO and so forth, for example, are cited as other raw materials. In the meantime, though the EPDM solid material has been employed as a solid material, any other solid material or fine foaming material may be employed; more specifically, what has a hardness of not less than 65 degrees and not greater than 85 degrees in the JIS-A type is preferable and in the case of the fine foaming material, what has a foaming quantity of not greater than 25% is preferable. As raw material, TPO, PP and so on are enumerated.