Three-jaw necking machine synchronizing by rack

Abstract

The invention relates to a three-jaw necking machine synchronizing by a rack, which comprises a supporting seat, a telescopic arm, a first rotating arm, a second rotating arm, three jaws, a first gear set, a second gear set and an executing cylinder, wherein the telescopic arm can be connected to the supporting seat in an up-and-down moving way, and a rack with a guide post is arranged below the telescopic arm; the first rotating arm and the second rotating arm are respectively connected to the supporting seat rotatablely by a first pin shaft and a second pin shaft and are also positioned at both sides of the telescopic arm symmetrically; each jaw is respectively connected to the first rotating arm, the second rotating arm and the telescopic arm; the first gear set is connected to the first rotating arm, the second gear set is connected to the second rotating arm, and the first gear set and the second gear set are symmetrically engaged with the rack with the guide post respectively; and the first rotating arm and the second rotating arm rotate around the axes of the first pin shaft and the second pin shaft respectively under the action of the executing cylinder also by the engaging relationship of the first gear set, the second gear set and the rack with the guide post, the telescopic arm is in telescopic movement on the supporting seat, and the three jaws move simultaneously under the driving of the first rotating arm, the second rotating arm and the telescopic arm respectively so as to present the arrangement of necking of the jaws or opening of the jaws.

Description

technical field [0001] The invention relates to a three-jaw necking machine in the field of steel pipe production, in particular to a three-jaw necking machine synchronized by racks which can produce seamless steel pipes by adopting a pipe jacking process. Background technique [0002] At present, there are many methods for the production of hot-rolled seamless steel pipes, such as periodic pipe rolling, automatic pipe rolling, three-roll pipe rolling, two-roll cross rolling, continuous rolling pipe, etc., and the pipe jacking process is also one of them. [0003] The working principle of the pipe jacking process is to push the ejector rod through the transmission rack, so that the capillary pipe after the pre-piercing mandrel has been shrunk passes through multiple roller dies to extend the pipe jacking and roll out the waste pipe, so as to achieve diameter reduction, wall reduction and extension. Purpose. The steel pipe produced by the pipe jacking process has a series of...

AI Technical Summary

Problems solved by technology

[0007] 1. Since there are only two jaws 2' and 3' on the entire circumference of the necking pipe section, the metal covered by each jaw has poor fluidity in the jaws, which affects the uniformity of the shape, wall thickness and strength of the necking cup. sexual influence;

[0008] 2. In addition to the actuator (hydraulic cylinder) required to complete the necking, the position of the necking center also needs to be controlled by a separate actuator (hydraulic cylinder or air cylinder). The control process is relatively cumbersome and increases the steps and time of the process , which also increases the temperature drop of the steel pipe;

[0009] 3. It is difficult for the two jaws 2' and 3' to move centripetally synchronously, and the center position of the necking changes greatly during the necking process

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