Internal high pressure forming push head of embedded-type engagement sealing structure

Abstract

The invention discloses an internal high pressure forming push head of an embedded-type engagement sealing structure. The internal high pressure forming push head comprises a cylindrical push head body. The front end of the push head body is provided with an embedded-type sealing head which comprises a guide head and an embedded-type sealing section. The diameter of the guide head is smaller than the inner diameter of a tube blank. The front end of the guide head is provided with a fillet, and the rear end of the guide head is provided with the embedded-type sealing section. The embedded-type sealing section comprises N circles of embedded rings and N circles of containing grooves. The axial lengths of all levels of the embedded rings are the same, and the diameters of the embedded rings are increased in an equal difference mode step by step. The diameter of the first level of embedded ring is larger than that of the guide head, and the diameter of the tail level of embedded ring is equal to that of the push head body. The gradient alpha1 of the outer diameters of the first level of embedded ring and the tail level of embedded ring is 20-45 degrees. The annular containing grooves which are recessed backwards are formed between the two adjacent levels of the embedded rings, and the cross section included angle alpha2 between the embedded rings and the containing grooves at the same level is smaller than 90 degrees. The sealing property of the push head and the tube end of the tube blank is good, the phenomenon that the guide head gets stuck into a mold cavity due to radial expansion of the tube end by radial force under the thrust action can be avoided, and therefore material feeding and replenishing can be performed more smoothly and uniformly, and the tube blank can be better formed.

Description

technical field [0001] The invention relates to a high-pressure forming die, in particular to an internal high-pressure forming push head with an embedded occlusal sealing structure. Background technique [0002] Pipe internal high pressure forming is a method of filling the pipe with liquid and pressurizing it, and applying lateral thrust in the axial direction to feed the material, forcing the pipe blank to fit into the mold cavity under the pressure of the pressurized medium, so as to realize the tube blank forming. process, the pressure inside the pipe is generally as high as 100MPa-400MPa, and most of the formed parts need to be kept under high pressure for a period of time to achieve a good forming effect, so the sealing structure of the pipe end is good or bad. It is very important for the internal high pressure forming process, which directly affects whether the ultra-high pressure state can be realized, and thus affects whether the forming of pipe parts can achieve ...

AI Technical Summary

Problems solved by technology

[0004] 1. During the process of pressing the main body of the push head, the feeding resistance of the tube blank is often increased or stuck in the mold cavity, which causes the mold or the push head to be worn, deformed and damaged, which seriously affects the service life and reliability of the mold and push head. ;

[0005] 2. The use of this type of pipe end sealing structure is likely to cause radial expansion of the pipe opening, thereby increasing the difficulty of feeding the pipe blank, resulting in thinning or rupture of the pipe wall during forming. In severe cases, the push head and pipe fittings will be directly stuck in the joint. In the mold cavity

[0006] 3. The sealing structure disclosed in Chinese patent CN101011715, one is that it is easy to cause bulging at the left and right guide holes at both ends, and the other is that the use of this sealing structure requires an additional pusher structure of "with the cavity" and "guide hole". Complicated, poor manufacturing process, high manufacturing cost, and soft rubber, due to the high internal pressure, it is very easy to wear and often needs to be replaced, which not only increases the cost, but also wastes time

[0007] 4. The sealing structure disclosed in Chinese patent CN202097262U is also provided with a tapered sealing surface. Although it is also provided with a thrust table, under the action of a large axial thrust of the push head, the pipe material in contact with the push head thrust table is prone to damage. Collapse, at this time, due to the existence of the conical sealing surface, the radial expansion of the nozzle will also be caused during the process of the push head continuing to feed, which will increase the difficulty of feeding the tube blank, resulting in thinning or rupture of the tube wall during forming; When there are machining errors in the processing of the conical surface sinking of the pipe end, due to the deep depth of the conical surface sinking of the pipe end, it is easy to cause the radial expansion of the pipe opening and the excessive depth of the sinking table of the pipe end, resulting in poor sealing of the conical sealing surface

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