Method for manufacturing a pipe with projections
AssigneesMitsui & Co., Ltd., Kokan Kako Co., Ltd.
InventorMasanobu Nakamura
Life of this patent
Estimating the term…
Abstract
A method for forming branch pipes on the periphery of a pipe, such as a manifold for automobiles, is characterized in that the branch pipes are formed by a bulging process to have a predetermined thickness without thinning. A first embodiment includes the step of indenting a pipe member by press work or the like, at locations close to the position of a projection, in a preliminary deforming process. A second embodiment employs a bulge mold having fixed spaces and variable spaces for forming a plurality of projections. The second embodiment includes the step of bulging the pipe material into the fixed spaces while the variable spaces are occupied by detachable members, and the step of removing the detachable members from the mold and then bulging the pipe member again.
Claims11
A method for manufacturing a pipe with projections using an apparatus which includes a bulge mold having at least one fixed space at an axially middle position and having variable spaces at the sides of the at least one fixed space, detachable members detachably mounted in the variable spaces to fully occupy the variable spaces, and holding members which press a pipe member inside the bulge mold from both ends, said method comprising the steps of:
- housing the pipe member in the bulge mold, with the detachable members being mounted in the variable spaces;
- holding tightly the pipe member with the bulge mode;
- introducing pressurized fluid into the pipe member and using the holding members to apply pressure on the pipe member toward the center thereof to bulge an intermediate portion thereof to form at least one projection;
- removing the detachable members from the variable spaces after the at least one projection is formed;
- and
- introducing pressurized fluid into the pipe member and using the holding members to apply pressure on the pipe member toward center thereof to form bulged portions at positions closer to the ends of the pipe member.
A method for manufacturing a pipe with projections, comprising the steps of:
- (a) placing a pipe member in a bulge mold having a fixed recess and a variable recess;
- (b) placing a detachable member in the variable recess, the detachable member having a surface which contacts the pipe member;
- (c) immobilizing the detachable member;
- (d) while the detachable member is immobilized, expanding the wall of the pipe member into the fixed recess with pressurized fluid;
- (e) releasing the detachable member;
- and
- (f) expanding the wall of the pipe member into the variable recess with pressurized fluid.
Dependencies are inferred from the claim text.