Abstract: A shaft manufacturing apparatus includes a first drawing die having a cylindrical first cavity defined therein which is open at both ends thereof and a second drawing die having a cylindrical second cavity defined therein which is open at one end thereof. The angle formed between a first tapered part of the first drawing die and the axis of the first cavity is greater than the angle formed between a second tapered part of the second drawing die and the axis of the second cavity.

Abstract: A primary product is formed by performing forward extrusion of a work in the first step, and a secondary product is formed by performing swaging in the second step. In the third step, preliminary pushing of the upper surface of the secondary product is performed to obtain a tertiary product where a recess generally matching the longitudinal section in the axial direction of the bottom wall of a cup portion of the final product is formed in the upper surface. In the fourth step, a quaternary product having a cup portion provided with a ball rolling groove in the inner wall is formed by performing backward extrusion of the tertiary product by using a punch having a tip shape generally matching the longitudinal section of the recess. Finally, in the fifth step, an outer ring member is produced as a final product by performing ironing of the cup portion of the quaternary product.

Abstract: A shaft manufacturing apparatus includes a first drawing die having a cylindrical first cavity defined therein which is open at both ends thereof and a second drawing die having a cylindrical second cavity defined therein which is open at one end thereof. The angle formed between a first tapered part of the first drawing die and the axis of the first cavity is greater than the angle formed between a second tapered part of the second drawing die and the axis of the second cavity.

Abstract: An apparatus and a method for manufacturing an outer ring member for a constant velocity joint and an intermediate molded body. The apparatus includes a molding land formed in circular arc shape in cross section with a prescribed radius of curvature, a relief part continued with the molding land part, and a correcting land part continued with the relief part and larger than the outer diameter of the relief part formed at one end outer peripheral surface of a second punch for forming a hole in a shaft part drawn by a shaft part molding part. The entire part of the molding land part of the second punch is formed to be positioned between the upper end F1 and the lower end F2 of the shaft part molding part in the vertical direction of the through hole of a lower die.

Abstract: A method of manufacturing an outer ring member for a constant velocity joint, comprising the steps of forming a secondary molding by applying a preliminary upsetting to a work after applying a forward extrusion-molding to the work, forming intermediate pre-molded bodies having annular sloped surfaces formed thereon to have a difference in flow resistance between large diameter parts and small diameter parts by applying the upsetting to the upper part of the secondary molding, forming a quaternary molding having a cup part with track grooves by applying a backward extrusion-molding to the intermediate pre-molded bodies, and applying an ironing to the cup part of the quaternary molding to finish the quaternary molding to product dimensions.

Abstract: The present invention provides an aqueous lubricant for plastic working which comprises (a) 10 to 40% by mass of a solid lubricating agent; (b) 2 to 20% by mass of an attaching agent having both lubricating and dispersing properties; (c) 2 to 20% by mass of an agent having both wetting characteristics and moisture evaporation-accelerating actions; and water. The use of this lubricant solves problems associated with conventional aqueous lubricants such that it has insufficient lubricating property and likewise permit the completion of a plurality of continuous plastic working steps, starting from a raw material and extending over a final product, without suspending a series of these plastic working steps in the middle thereof.

Abstract: A method of manufacturing an outer ring member for a constant velocity joint, comprising the steps of forming a secondary molding by applying a preliminary upsetting to a work after applying a forward extrusion-molding to the work, forming intermediate pre-molded bodies having annular sloped surfaces formed thereon to have a difference in flow resistance between large diameter parts and small diameter parts by applying the upsetting to the upper part of the secondary molding, forming a quaternary molding having a cup part with track grooves by applying a backward extrusion-molding to the intermediate pre-molded bodies, and applying an ironing to the cup part of the quaternary molding to finish the quaternary molding to product dimensions.

Abstract: The invention is directed to provide a forming method and a forming apparatus that are, without extending a processing time compared with the conventional practice, capable of sufficiently lubricating a formed object and forming at safety without the lubricant igniting under pressure. In an extruding apparatus, a workpiece is successively transferred to a series of press stages, a conveying unit successively transferring the workpiece is provided with a nozzle for spraying the workpiece with lubricant, and the workpiece and the nozzle are located in fixed relative positions to each other in spraying the workpiece with the lubricant.

Abstract: An outer ring member for a constant velocity joint is manufactured. An intermediate preformed product having a cup section with an incomplete shape is formed by pressing a large diameter section without applying a low temperature annealing treatment and a lubricating chemical conversion coating treatment. Then, applying a low temperature annealing treatment and a lubricating chemical conversion coating treatment to the intermediate preformed product, thereafter a formed product having a cup section provided with ball-rolling grooves is formed by backward extrusion to the intermediate preformed product. Subsequently, the product is ironed before hardening, without applying a low temperature annealing treatment and a lubricating chemical conversion coating treatment to the formed product.

Abstract: A forging die apparatus comprises a punch for applying a pressurizing force to a forging material arranged in a cavity, a cylindrical member installed to surround a part of outer circumference of the punch, for making displacement integrally with the punch, and a first ring member formed with a hole for forcibly inserting the cylindrical member therein when the punch applied the pressurizing force to the forging material.

Abstract: A forging die apparatus comprises a punch for applying a pressurizing force to a forging material arranged in a cavity, a cylindrical member installed to surround a part of outer circumference of the punch, for making displacement integrally with the punch, and a first ring member formed with a hole for forcibly inserting the cylindrical member therein when the punch applied the pressurizing force to the forging material.

Abstract: An outer ring member for a constant velocity joint is manufactured. An intermediate preformed product 16 having a cup section 21 with an incomplete shape is formed by pressing a large diameter section 14 without applying a low temperature annealing treatment and a lubricating chemical conversion coating treatment. Then, applying a low temperature annealing treatment and a lubricating chemical conversion coating treatment to the intermediate preformed product 16, thereafter a formed product having a cup section 8 provided with ball-rolling grooves 17a to 17f is formed by backward extrusion to the intermediate preformed product 16. Subsequently, the product is ironed before hardening, without applying a low temperature annealing treatment and a lubricating chemical conversion coating treatment to the formed product.

Abstract: In order to obtain uniform pressing force applied to a workpiece by an ironing die and easily disengage the workpiece after completing plastic working for the workpiece, a forming machine for performing the plastic working for the workpiece has a base pedestal, a forming punch provided on the base pedestal, and an annular ironing die arranged over the forming punch. The forming punch comprises a main punch body, six punch collets to be engaged with the main punch body and separated from each other at equal angles, a metal sleeve externally fitted to the main punch body and the punch collets, and a holder for holding the metal sleeve.

Abstract: A hydraulic pressure control apparatus comprises a high pressure accumulator for sucking pressure oil supplied to a relief chamber of a relief valve to make changeover for the relief valve from a valve-closed state to a valve-open state when a forming load is applied to the pressure oil charged in a pressure chamber and the hydraulic pressure of the pressure oil arrives at a relief preset pressure, and a low pressure accumulator for sucking the pressure oil charged in the pressure chamber via the relief valve which is in the valve-open state.

Abstract: In order to obtain uniform pressing force applied to a workpiece by an ironing die and easily disengage the workpiece after completing plastic working for the workpiece, a forming machine for performing the plastic working for the workpiece has a base pedestal, a forming punch provided on the base pedestal, and an annular ironing die arranged over the forming punch. The forming punch comprises a main punch body, six punch collets to be engaged with the main punch body and separated from each other at equal angles, a metal sleeve externally fitted to the main punch body and the punch collets, and a holder for holding the metal sleeve.

Abstract: A hydraulic pressure control apparatus comprises a high pressure accumulator for sucking pressure oil supplied to a relief chamber of a relief valve to make changeover for the relief valve from a valve-closed state to a valve-open state when a forming load is applied to the pressure oil charged in a pressure chamber and the hydraulic pressure of the pressure oil arrives at a relief preset pressure, and a low pressure accumulator for sucking the pressure oil charged in the pressure chamber via the relief valve which is in the valve-open state.

Abstract: A hydraulic pressure control apparatus comprises a high pressure accumulator for sucking pressure oil supplied to a relief chamber of a relief valve to make changeover for the relief valve from a valve-closed state to a valve-open state when a forming load is applied to the pressure oil charged in a pressure chamber and the hydraulic pressure of the pressure oil arrives at a relief preset pressure, and a low pressure accumulator for sucking the pressure oil charged in the pressure chamber via the relief valve which is in the valve-open state.

Abstract: A forging die apparatus comprises a punch for applying a pressurizing force to a forging material arranged in a cavity, a cylindrical member installed to surround a part of outer circumference of the punch, for making displacement integrally with the punch, and a first ring member formed with a hole for forcibly inserting the cylindrical member therein when the punch applies the pressurizing force to the forging material.

Abstract: A forge-molding method for forming a constant velocity joint outer ring comprising a shaft and a cup formed integral with and expanding radially and outwardly from one end of the shaft is provided. The method uses an ironing die apparatus which is provided with a lower molding die, an upper molding die and an ironing punch. The lower molding die is provided with a first cavity formed to have a final degree of product accuracy with respect to the shaft and adapted to apply a final ironing process to the shaft, while the upper molding die is provided with a second cavity for restraining the outer peripheral surface of the cup. Consequently, the accuracy of concentricity between the shaft and the cup can be securely maintained in a simple manner and a sufficient degree of accuracy of the inner peripheral surface and/or the inner diameter of the cup can be effectively secured.

Abstract: A forging die apparatus comprises a punch for applying a pressurizing force to a forging material arranged in a cavity, a cylindrical member installed to surround a part of outer circumference of the punch, for making displacement integrally with the punch, and a first ring member formed with a hole for forcibly inserting the cylindrical member therein when the punch applies the pressurizing force to the forging material.