| 摘要 |
PCT No. PCT/FI91/00063 Sec. 371 Date Oct. 5, 1992 Sec. 102(e) Date Oct. 5, 1992 PCT Filed Mar. 5, 1991 PCT Pub. No. WO91/13707 PCT Pub. Date Sep. 19, 1991.A stabilizer bar or a similar metallic tube product for vehicles, has a central portion and at least two bent portions forming legs. The bar includes a thick-walled metallic tube having in the central portion a wall thickness and outside diameter in a ratio amounting to at least 1/10. This tube has an outside wall portion bent with a restricted thinning, ranging from about 5 to 15%. The bent portions are bent with an average bending radius of curvature in the range from about 1.4 to 2.1 times the outside diameter of the tube. Apparatus and methods can manufacture stabilizer bars or similar tubular metallic products of the foregoing type. For example, a method includes the steps of fitting to a bending arm one end of the thick-walled metallic tube. An inside wall portion of the tube has a radial spacing from a bending center of curvature, no greater than the length of the bending arm. The tube and the heating zone move relatively, with the heating zone advancing along the tube. Circular movement of the bending arm is resisted with a force sufficient to displace the flexure plane (separating compression zone from tension zone) radially outward from the center of curvature and to thin the outside wall of the metallic tube by about 5 to 15%. Resistance of the circular movement can be preformed with a gear and gear rack.
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