Method for forming special-shaped section annular piece through thermal expansion of bearing steel rectangular section annular piece

Abstract

The invention discloses a method for forming a special-shaped section annular piece through thermal expansion of a bearing steel rectangular section annular piece. The method includes the steps that a preheated die sleeve is fixed on a working table of a bulging machine, the periphery of a preheated bulging block in the bulging machine is sleeved with the heated bearing steel rectangular section annular piece so as to enable the heated bearing steel rectangular section annular piece to be located in an annular space defined by the outer circumferential surface of the bulging block and the inner annular surface of the die sleeve; the bulging machine is started up to enable the bulging block to extrude the annular piece from the inner circumferential surface of the annular piece in the radial direction, and the annular piece deforms by 10-14% and then is extruded in the inner annular surface of the die sleeve. The annular piece is filled with a closed mold cavity after being extruded, wherein the closed mold cavity is defined by the outer circumferential surface of the bulging block and the inner annular surface of the die sleeve, and then the annular piece forms the special-shaped section annular piece through pressure maintaining. The method simplifies operation through one-time large deformation amount of bulging and forming, so that the bulging special-shaped section annular piece which is high in dimensional accuracy, good in product quality and high in production rate is obtained. The special-shaped section annular piece is mainly applicable to rotator parts used in the field of wind power generation and the like.

Description

technical field [0001] The invention relates to a method for bulging a ring, in particular to a method for thermally expanding a ring with a rectangular cross-section of bearing steel to form a ring with a special-shaped cross-section. Background technique [0002] In the field of ring forming technology, with the development of aviation, aerospace, shipbuilding, nuclear energy, gas turbines, wind power and other industries, the requirements for high reliability, long life and low cost of ring parts require the forming dimensional accuracy, structure and quality of ring parts. Performance also puts forward higher requirements, and the forming of ring parts is developing in the direction of high quality, precision, high efficiency, environmental protection and low cost. [0003] Bearing steel rectangular cross-section rings (referring to rings with a rectangular longitudinal section) or rings with special-shaped cross-sections (referring to rings with a non-rectangular longit...

AI Technical Summary

Problems solved by technology

The method adopts the open bulging method to bulge and form the ring parts of bearing steel special-shaped cross-sections. The dimensional accuracy of the outer diameter and height of the ring part cannot reach this dimensional accuracy, because the dimensional accuracy of the outer diameter and height of the annular part is not controlled during the bulging process, and its size cannot be improved by this bulging method. Second, in the process of using this method to bulge a rectangular cross-section ring into a special-shaped cross-section ring, because the lower half of the rectangular cross-section ring is first subjected to the bulging force from the bulging block, its lower half It is thinned by bulging first, and the metal flows from its lower half to its upper half. If the control is not good, it will easily cause too much metal accumulation in the upper half, so that the wall thickness of the special-shaped cross-sect

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