RU1802738C - Method of manufacture of bolt blanks - Google Patents

Abstract

Usage: metal forming. It can be used in the manufacture of bolt blanks with a stepped rod part and a multifaceted head by cold stamping. SUMMARY OF THE INVENTION: upon disembarkation of the heads, a stepped rod part of the bolt is formed by the draft. A larger diameter step is adjacent to the workpiece head. Then, the step of the rod of smaller diameter is reduced. 1 ill.

Description

The invention relates to pressure treatment and can be used in the manufacture of bolt blanks with a stepped rod part and a multi-faceted head by cold stamping.

 The purpose of the invention is to increase durability; tool and expansion of technological capabilities of the process.

; The drawing shows the sequence of transitions of the technological process of manufacturing the blanks of bolts.

; The method is carried out as follows:

0 cut workpiece 1 is transferred to the upsetting position, where the punch 2 in the matrix 3 | relying on the ejector 4, pre-formation by head landing (| and sediment of the stepped rod part | and. The next landing is the final landing and the formation of sediment stepped rod part. Reducing the step of a smaller diameter rod is carried out on the penultimate, and cutting heads to the polyhedron at the last transition.

Example. The manufacture of M27 x 120 bolts in accordance with GOST 7798-70 from steel grade 40X in accordance with GOST 10702-78.

Landing of bolt blanks and thread rolling was carried out on a KA-84 four-position machine according to the diagram shown in the drawing. Then, the bolts were heat treated for strength class 109 according to GOST 1759.4-87. Landing was carried out from workpieces do 25.4 mm. In the first position, a head and a stepped rod are pre-formed with a diameter of di 26.2 mm and a d2 of 25.6 mm. In the second position, the final formation of the head and the stepped rod part is carried out with a diameter d3 of 26.8 mm and a d4 of 25.8 mm. At the third position, the rod is reduced under knurling

ate

with

00

about

Yu

vj cj 00

with

with tolerance 6q. Bar diameter ds 24.9 mm. In step IV, the hex head is cut with a 41 mm turnkey size. Compared with the known method, the resistance of the reducing matrices increased by 20% on rolling dies.

Example. Was carried out according to the proposed method, the landing of blanks mounting step bolts M22 x 85 according to TU 14-4-1385-86 from steel grade 20 according to GOST 10702-78 on a KA-74 automatic machine. Landing was carried out from a workpiece with a diameter of do 23.0 mm. At position I, the head and stepped rod are pre-formed with diameters di 24.5 mm and da 23.2 mm. In the second position, the final formation of the head and the stepped rod part is carried out with a diameter da 25.4 mm and d4 23.4 mm. In stage III, the rod is reduced to a diameter d5 of 20.2 mm. On IV position

0

5

0

pruning a 36 mm hexagonal head. The ratio da / ds was 1.26.

Claims (1)

SUMMARY OF THE INVENTION A method for manufacturing bolt blanks with a stepped rod part and a multifaceted head, comprising a segment of the initial workpiece, preliminary and final head disembarkation with simultaneous rod upsetting, reduction of a part of the rod for threading and trimming the side surface of the head along the perimeter with the formation of a polyhedron, characterized in that that, in order to increase the tool life and expand the technological capabilities of the process, a stepped shape of the rod is obtained in the process of settling the rod at the preliminary and final stages of head disembarkation, and a step of a rod of smaller diameter is subjected to reduction. -E . "