Method of Manufacturing Plastic Component Assembly and Plastic Component Assembly, and Plastic Component Welding Head and Plastic Component Welding Machine
A lower half ( 102 ) and an upper half ( 103 ) are plastic components having thermoplasticity. A welding head ( 1 ) having a plurality of convex portions formed in a circumferential direction, the convex portions extending in a longitudinal direction within a range of a predetermined length, is inserted so as to span a lower boss ( 107 ) and an upper boss ( 110 ) in a joint portion ( 105 ). The plastic in the joint portion ( 105 ) is melted by means of the welding head ( 1 ). The lower half ( 102 ) and the upper half ( 103 ) are welded to and integrated with each other by solidifying the molten plastic.
1 . A method of manufacturing a plastic component assembly in which a first and a second plastic components having thermoplasticity are integrated to form a plastic component assembly, the method comprising:
abutting a welding head used for ultrasonic or heat welding having a cylindrical whole contour against a joint portion where the first and second plastic components abut to each other, a plurality of concave portions which are concave than a circumferential surface of the welding head and a plurality of convex portions which are convex than the plurality of concave portions toward the circumferential surface side being alternately formed in a circumferential direction within a range of a predetermined length at an end side of a longitudinal direction of the welding head, and the welding head having a taper portion in which, for the plurality of convex portions, a diameter thereof becomes smaller toward an end side from a root side of the welding head;
inserting the welding head into the joint portion such that the taper portion passes through the joint portion while a plastic in the joint portion is molten by means of the welding head; and
solidifying the melted plastic and thereby causing the first and the second plastic components to be welded to and integrated with each other.
2 . (canceled)
3 . The method of manufacturing a plastic component assembly according to claim 1 , wherein:
the first plastic component includes a first boss having a hole with a first inner diameter formed in a bottom portion;
the second plastic component includes a second boss with a second inner diameter not greater than the first inner diameter;
the joint portion includes a portion where the bottom portion of the first boss and the second boss abut to each other; and
the welding head, in which a diameter of a circumcircle circumscribing the plurality of convex portions is larger than the first inner diameter at least at a part within the range of the predetermined length, is used as the welding head.
4 . The method of manufacturing a plastic component assembly according to claim 3 , wherein the welding head, in which a diameter of a circle contacting the respective innermost portions of the plurality of concave portions is smaller than the second inner diameter at least at a part within the range of the predetermined length, is used as the welding head.
5 . (canceled)
6 . The method of manufacturing a plastic component assembly according to claim 1 , wherein the welding head, in which a side edge portion of a top portion of the plurality of convex portions is inclined relative to a center line in a longitudinal direction of the welding head at least at a part within the range of the predetermined length, is used as the welding head.
7 . The method of manufacturing a plastic component assembly according to claim 1 , wherein the welding head, in which the respective innermost portions of the plurality of concave portions have a diameter becoming smaller toward an end of the welding head at least at a part within the range of the predetermined length, is used as the welding head.
8 . (canceled)
9 . A plastic component assembly comprising:
a first plastic component having thermoplasticity; and
a second plastic component having thermoplasticity and integrated with the first plastic component: wherein
the first and second plastic components are joined to each other at a joint portion where the first and second plastic components abut to each other;
a void portion spanning the first and second plastic components is formed in the joint portion; and
a solidified plastic faces the void portion integrally with the first and second plastic components so as to span the first and second plastic components, the solidified plastic being obtained by solidifying a molten plastic in which the first and second plastic components are melted,
the first plastic component includes a first boss having a hole with a first inner diameter formed in a bottom portion;
the second plastic component includes a second boss with a second inner diameter not greater than the first inner diameter;
the joint portion includes a portion where the bottom portion of the first boss and the second boss abut to each other;
the void portion extends over the second boss from the bottom portion of the first boss; and
the solidified plastic extends over the second boss from the bottom portion of the first boss.
10 . The plastic component assembly according to claim 9 , wherein the void portion includes a plurality of convex portions and a plurality of concave portions in a circumferential direction.
11 . A plastic component welding head used for welding a first and a second plastic components having thermoplasticity by ultrasonic waves or heat, the plastic component welding head comprising:
a cylindrical root portion; and
an end portion integrally continuous to the root portion, wherein
the end portion, at which a plurality of concave portions which are concave than a circumferential surface of the root portion and a plurality of convex portions which are convex than the plurality of concave portions toward the circumferential surface side are alternately formed in a circumferential direction within a range of a predetermined length in a longitudinal direction, has a taper portion in which, for the plurality of convex portions, a diameter thereof becomes smaller toward an end side of the end portion from the root portion side; and
the taper portion is inserted into a joint portion where the first and second plastic components abut to each other to melt a plastic in the joint portion.
12 . (canceled)
13 . The plastic component welding head according to claim 11 , wherein
the taper portion includes:
a first taper portion positioned on an end side of the plastic component welding head and inclined with a first inclination angle; and
a second taper portion positioned on the root portion side than the first taper portion and inclined with a second inclination angle gentler than the first inclination angle.
14 . The plastic component welding head according to claim 11 , wherein a side edge portion of a top portion of the plurality of convex portions is inclined relative to a center line in a longitudinal direction of the plastic component welding head at least at a part within the range of the predetermined length.
15 . The plastic component welding head according to claim 11 , wherein for the respective innermost portions of the plurality of concave portions, a diameter thereof becomes smaller toward an end of the plastic component welding head at least at a part within the range of the predetermined length.
16 . A plastic component welding machine used for welding a first and a second plastic components having thermoplasticity by ultrasonic waves, the plastic component welding machine comprising:
an oscillator that generates an electrical oscillation signal;
an ultrasonic vibration generator that generates a mechanical ultrasonic vibration based on the oscillation signal; and
a welding head, the welding head provided integrally with the ultrasonic vibration generator or attached as a separate component to the ultrasonic vibration generator, that ultrasonically welds the first and second plastic components by the ultrasonic vibration, wherein
the welding head includes:
a cylindrical root portion; and
an end portion integrally continuous to the root portion, and wherein
the end portion at which a plurality of concave portions which are concave than a circumferential surface of the root portion and a plurality of convex portions which are convex than the plurality of concave portions toward the circumferential surface side are alternately formed in a circumferential direction within a range of a predetermined length in a longitudinal direction, has a taper portion in which, for the plurality of convex portions, a diameter thereof becomes smaller toward an end side of the end portion from the root portion side; and
the taper portion is inserted into a joint portion where the first and second plastic components abut to each other to melt a plastic in the joint portion.
17 . (canceled)
18 . The plastic component welding machine according to claim 16 , wherein
the taper portion includes:
a first taper portion positioned on an end side of the welding head and inclined with a first inclination angle; and
a second taper portion positioned on the root portion side than the first taper portion and inclined with a second inclination angle gentler than the first inclination angle.
19 . The plastic component welding machine according to claim 16 , wherein a side edge portion of a top portion of the plurality of convex portions is inclined relative to a center line in a longitudinal direction of the welding head at least at a part within the range of the predetermined length.
20 . The plastic component welding machine according to claim 16 , wherein for the respective innermost portions of the plurality of concave portions, a diameter thereof becomes smaller toward an end of the welding head at least at a part within the range of the predetermined length.