Insert cutting and weatherstrip manufacturing method
A weatherstrip manufacturing method is a method for manufacturing a weatherstrip which includes a trim portion where an insert is embedded. The insert includes short connecting portions that connect strips at substantially regular intervals, and a long connecting portion having a larger length than each length of the short connecting portions. The method includes an extrusion molding step for covering the insert with a polymer material, a cut-off portion forming step for cutting off a part of a long interval portion including the long connecting portion in the long interval portion where the long connecting portion is embedded to form a cut-off portion, and a cutting step for cutting the cut-off portion in a crossing direction orthogonal to a longitudinal direction to divide the weatherstrip in the longitudinal direction.
1. A weatherstrip manufacturing method for manufacturing a weatherstrip that includes a trim portion having a substantially U-shaped cross section and including an insert embedded in the trim portion, the insert having a belt shape and including strips connected via a connecting portion, wherein
the connecting portion of the insert includes short connecting portions that connect the strips at substantially regular intervals, and a long connecting portion that has a larger length than each length of the short connecting portions; and
the method comprising:
an extrusion molding step for covering the insert with a polymer material;
a cut-off portion forming step for cutting off a part of a long interval portion to form a cut-off portion, wherein the part of the long interval portion that is cut off includes the long connecting portion of the insert embedded in the long interval portion; and
a cutting step for cutting the cut-off portion in a crossing direction orthogonal to a longitudinal direction to divide the weatherstrip in the longitudinal direction.
2. The weatherstrip manufacturing method according to claim 1 , further comprising a long connecting portion forming step for forming the long connecting portion by cutting the strip in the short connecting portion of the insert before the extrusion molding step.
3. The weatherstrip manufacturing method according to claim 2 , wherein the cut-off portion forming step is performed subsequent to the long connecting portion forming step.
4. The weatherstrip manufacturing method according to claim 1 , wherein the cut-off portion forming step is performed by using a punch that is a movable upper blade, and a die that is a fixed lower blade, and
inserting the punch from an opening side of the trim portion,
wherein, in a cross-section perpendicular to the longitudinal direction, the die includes a projection that includes an inclined surface formed on two opposing sides of the punch extending toward the punch.
5. The weatherstrip manufacturing method according to claim 4 , wherein a height of the projection is equal to a thickness of the polymer material covering the insert.
6. The weatherstrip manufacturing method according to claim 4 , wherein an inclination angle of the inclined surface is between 30° and 60°.
7. The weatherstrip manufacturing method according to claim 1 , wherein the cut-off portion forming step is performed subsequent to the extrusion molding step.