Bolt and method of manufacturing the same
AssigneesHonda Motor Co., Ltd., Saga Tekkohsho Co., Ltd.
InventorsKazuhiro Tsuzaki, Toshitsugu Sakakibara, Kenichiro Katsuki
Life of this patent
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Abstract
A bolt includes a head portion on which a recess is formed. The recess has a bottom surface and a sidewall extending from a periphery of the bottom surface. The sidewall has a lower end defined by the bottom surface and includes an increased diameter portion and a reduced diameter portion. The increased diameter portion has an inner diameter larger than an inner diameter of the lower end of the side wall. The reduced diameter portion has an inner diameter smaller than the inner diameter of the increased diameter portion. The reduced diameter portion is located opposite to the bottom surface across the increased diameter portion.
Claims10
A bolt comprising:
- a head portion on which a recess is formed,
- wherein the recess has a bottom surface and a sidewall extending from a periphery of the bottom surface,
- wherein the sidewall has a lower end defined by the bottom surface and includes an increased diameter portion and a reduced diameter portion, the increased diameter portion having an inner diameter larger than an inner diameter of the lower end of the sidewall, the reduced diameter portion having an inner diameter smaller than the inner diameter of the increased diameter portion, the reduced diameter portion located opposite to the bottom surface across the increased diameter portion.
A bolt comprising:
- a head portion on which a recess is formed,
- wherein the recess has a bottom surface and a sidewall extending from a periphery of the bottom surface,
- wherein the sidewall has a lower end defined by the bottom surface and includes an increased diameter portion and a reduced diameter portion, the increased diameter portion having an inner diameter larger than an inner diameter of the lower end of the sidewall, the reduced diameter portion having an inner diameter smaller than the inner diameter of the increased diameter portion, the reduced diameter portion located opposite to the bottom surface across the increased diameter portion, and
- wherein the bolt can be inspected by ultrasonic waves in such a manner that a probe for ultrasonic testing is placed in the recess.
A method of manufacturing a bolt having a shaft portion and a head portion with a recess, the method comprising:
- forming the shaft portion by performing a shaft reducing process on a wire rod;
- and
- forming the head portion by performing an upsetting process on one end portion of the wire rod on a side opposite from the shaft portion,
- wherein a molding die for performing the upsetting process has a bottom portion and a stepped protrusion formed on the bottom portion, the stepped protrusion located at a position corresponding to the recess, the stepped protrusion configured to be pressed into the one end portion of the wire rod, and
- wherein the stepped protrusion includes:
- a first columnar portion formed on the bottom portion;
- and
- a second columnar portion formed coaxially on the first columnar portion and having a smaller diameter than the first columnar portion.
Dependencies are inferred from the claim text.