PURPOSE: To produce efficiently a hollow torsion bar with an arm by mounting the arm to the root end of a hollow pipe only by the cold machining and forming serrations for connecting a torsion bar, etc. to the top end of the hollow pipe.
CONSTITUTION: The required length at the end of a pipe 1 is reduced by swaging 11 to a required diameter. An arbor 2 is inserted into the pipe 1 and while a die 3 is pressed to the outside surface of the pipe 1 from just before the swaged part 11, the die is slid toward the direction where an arm is to be mounted, thereby extrusion-working of the pipe 1 except the part 11 to a required length of the outside surface. The pipe is thus thinnly walled 12 and hardened. A mandrel 4 formed with many serrations 41 is fitted into the part 11 and the part 11 is further reduced in diameter to form the serrations 41 on the inside surface of the part 11. An arm mounting part 13 is expanded by bulging while the mounting hole 61 of an arm 6 is held fitted into the part 13 of the pipe 1, whereby the arm 6 is securely mounted to the required position of the pipe 1.
HONDA MOTOR CO LTD
MITSUBISHI STEEL MFG
| JP51111944B | ||||
| JPS5626633A | 1981-03-14 |