Touch sensor unit and method of manufacturing the same
In a touch sensor unit, since a base portion is provided with a hard resin portion for holding a curved state of a sensor portion deformed in conformity to a curved shape of a door frame of a tail gate, even when the base portion is not fixed to the tail gate, it is possible to hold the curved state of the base portion. Therefore, after the curved base portion is fixed to the tail gate with a double-sided adhesive tape, even if the double-sided adhesive tape is degraded with age, a restoring force of the sensor portion does not remove the double-sided adhesive tape.
1. A touch sensor unit which is used for detection of contact with a blockage, comprising:
a hollow sensor portion which is elastically deformed by an external load;
electrodes which are provided inside the sensor portion, and brought into contact with each other by elastic deformation of the sensor portion;
an elastic base portion integrally provided with the sensor portion, the elastic base portion extending along a longitudinal direction of the sensor portion, the elastic base portion being fixed the sensor portion to a fixing object;
a curvature holding portion provided on the elastic base portion, and configured to hold a curved state of the sensor portion with the sensor portion deformed in conformity to a curved shape of the fixing object;
a width of the sensor portion along a transverse direction being smaller than that of the elastic base portion along a transverse direction;
the curvature holding portion being a cored bar which is provided inside the elastic base portion and is plastically deformed in conformity to the curved shape of the fixing object; and
a line segment which connects a center of the sensor portion and a center of the cored bar being perpendicular to a bottom surface of the elastic base portion.
2. The touch sensor unit according to claim 1 , wherein
the electrodes are a pair of electrodes helically provided inside the sensor portion.
3. The touch sensor unit according to claim 1 , wherein an adhesive tape configured to fix the elastic base portion to the fixing object is bonded to the bottom surface of the elastic base portion.
4. A method of manufacturing a touch sensor unit which is used for detection of contact with a blockage,
the touch sensor unit comprising:
a hollow sensor portion which is elastically deformed by an external load;
electrodes which are provided inside the sensor portion, and brought into contact with each other by elastic deformation of the sensor portion;
an elastic base portion integrally provided with the sensor portion, the elastic base portion extending along a longitudinal direction of the sensor portion, the elastic base portion being fixed the sensor portion to a fixing object; and
a curvature holding portion provided on the elastic base portion, and configured to hold a curved state of the sensor portion with the sensor portion deformed in conformity to a curved shape of the fixing object,
the method having steps of:
forming a notched portion which forms part of the elastic base portion and extends in a longitudinal direction of the elastic base portion;
setting the sensor portion and the elastic base portion in a mold with the notched portion located on an inner circumferential side of the curved elastic base portion; and
forming the curvature holding portion in the notched portion by supplying a molten resin into the mold.