Radial expansion type punch

Abstract

The invention relates to a radial expansion type punch, which is provided with a front punch (1), a first layer knife block, a second layer knife block, a third layer knife block (2, 3, 6) and a knifeblock base (5), wherein the knife block base is provided with two spaces (5a, 5b) inside; the peripheral surface of the knife block base in the same space is provided with three groups of knife blockradial expansion grooves (5-1, 5-2, 5-3); a shaft body of the front punch consists of a large stepped shaft, a medium stepped shaft and a small stepped shaft with certain tapers respectively; all thelayer knife blocks are arranged on the stepped shafts in sequence through the three groups of radial knife block radial expansion grooves respectively; the shaft end of the front punch passes througha washer (7) and is arranged in the other space; the other space is sealed by a retaining ring (11), and the sealed space is provided with a compression spring (10) inside; and all the layer knife blocks are provided with a tension spring (4) respectively. The radial expansion type punch is simple in structure, can avoid secondary welding line heat treatment and reduce production cost, and is suitable for large-scale drill pipes or two-pipe combined production lines.

Description

technical field [0001] The invention relates to a metal punching device, in particular to a radially expanding punch belonging to a cutter. Background technique [0002] In the production process of the drill pipe or the combination of the two reducing pipes, the drill pipe joint and the drill pipe body or the pipe body between the two reducing pipes are connected by the friction welding method, and the weld seam after friction welding There will be flash on the inner and outer walls. Due to the different hole diameters on the inner wall of the pipe, special processing methods must be used to remove the flash and make the inner cavity clean and smooth. Therefore, removing flash is an important key process. The traditional methods of removing flash include straight hole punching method, split punching method and grinding method. [0003] The straight hole punching method requires secondary heat treatment, and the production cycle is long; [0004] The split punching metho...

AI Technical Summary

Problems solved by technology

[0004] The split punching method puts the main punch in advance at the welding seam, which has great potential safety hazards;

[0005] The grinding efficiency of the grinding method is low

[0006] The above three methods need to adopt secondary heat treatment, the production cycle is long, the efficiency is low, the cost is high, and the safety is poor, so it is not suitable for large-scale production

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