RU2095185C1 - Spherical finger manufacture method - Google Patents

Abstract

FIELD: cold plastic working of metals. SUBSTANCE: method involves cutting billet; first preliminary upsetting of head and preliminary reduction of core; second preliminary upsetting of head and final reduction of core with final forming of cone; final upsetting of spherical head. At core preliminary reduction stage, cone is preliminarily formed on core portion adjoining cylindrical part below head at an angle equal to that of finally formed cone. Method allows parts with total deformation extent during reduction to be <0.7 and relative length of upset part to be > 4.5. EFFECT: increased efficiency, improved quality of ready parts and increased strength of tool due to absence of air cushion. 1 dwg

Description

 The invention relates to cold forming of metals.

 A known method of stamping a ball finger when the relative deformation during direct extrusion of the shank ψ <0.7, and the relative length of the upset part of the workpiece a> 4.5, in which a piece of the workpiece is produced, direct extrusion of the cone and shank, preliminary set of metal in the head, heading of the ball head (Forging and stamping. Handbook edited by GA Navrotsky. M. "Mechanical Engineering". 1987, v.3. P. 365, version 7).

 The disadvantage of this method is the loss of stability of the workpiece during landing of the ball head in two transitions at a> 4.5. In addition, due to the large loads during extrusion of the cone and the shank, the resistance of the matrix in the first position is low.

 Closest to the proposed one is a method of manufacturing spherical fingers, which includes cutting a workpiece, a first preliminary heading and head reduction, a second preliminary heading with a second head reduction and cone upsetting, a final ball heading with a diameter for knurling (Technological processes and tools, Gorky , 1986. RD 37.002.0455 85.p.32. Fig. 33).

 Due to the use of two preliminary conical sets before the final ball disembarkation, this method provides the required quality of the ball head at a> 4.5, however, the quality of the conical part of the rod of the parts obtained is poor, namely, incomplete filling of the cone, which occurs due to the fact that the cone is obtained in one transition simultaneously with the second reduction of the rod. In this case, an air-hydraulic “pillow” is formed between the workpiece and the inner conical surface of the matrix, which prevents the cone from filling completely. In the area of the air-hydraulic "cushion" solid particles accumulate, adversely affecting tool life and quality of parts. The implementation in the matrix of air-oil channels does not ensure the complete removal of solid particles from this zone due to clogging of the channels) complicates its design and reduces its resistance.

 The invention solves the problem of improving the quality of finished parts, increasing tool life when landing ball fingers, when the total relative deformation of the workpiece during reduction j <0.7, and the relative length of the planted part of the workpiece a> 4.5.

 This problem is solved by the fact that in the method of manufacturing ball fingers, comprising a piece of the workpiece, the first preliminary head landing and preliminary reduction of the rod, the second preliminary head landing and the final reduction of the rod with the final cone, the final head landing, at the stage of preliminary reduction of the rod, preliminary formation is performed cone on the part of the rod adjacent to the head-mounted cylindrical part, with an angle equal to the angle of the final cone.

 Stamping the ball finger in this way eliminates the possibility of forming an air-hydraulic "pillow" and thereby improves the quality of the conical part of the rod of the finished parts, in addition, simplifies the design of the tool and increases its durability.

The drawing shows a method of manufacturing ball fingers for technological transitions: and the first transition (piece of workpiece); b the second transition (the first preliminary heading and preliminary reduction of the rod with the preliminary design of the cone), the third transition (second preliminary heading with the final reduction of the rod and the final design of the cone), d the fourth transition (final heading),
The method is as follows. A measured workpiece with a diameter of 16.65 mm from steel 38KHGNM is cut from a rod or riot, in the first position, a preliminary heading and preliminary reduction of the core with a diameter of 15.3 mm are made, with a cone angle of 7 ^o , and a part of the cone is 11.5 mm long. In the second position, a second preliminary heading and final reduction of the rod with a diameter of 11.88 mm is made and the remainder of the cone is formed with an angle of 7, 6.5 mm long, after which the final heading of the ball head is made. The angle of the conical part of the rod is equal to 7 ^o , and a length equal to 18 mm in accordance with the requirement of the drawing of the finished part.

 The use of the invention ensures the production of ball fingers with high quality, eliminates the possibility of formation of an air-hydraulic "pillow" and the accumulation of solid particles in this zone, which negatively affect the tool life and quality of finished parts, eliminates the need for air-oil channels in the matrix, thereby simplifying the design of the tool, while increasing its resistance by 3-5 times.

Claims (1)

 A method of manufacturing spherical fingers, including a piece of workpiece, the first preliminary heading and preliminary reduction of the rod, the second preliminary heading and final reduction of the shaft with the final design of the cone, the final landing of the ball head, characterized in that at the stage of preliminary reduction of the rod, the cone is preliminarily formed the part of the rod adjacent to the head-end cylindrical part, with an angle equal to the angle of the final con mustache.