Multi-corrugation one-time forming device of EGR pipe and forming technology of multi-corrugation one-time forming device of EGR pipe

Abstract

The invention discloses a multi-corrugation one-time forming device of an EGR pipe. The one-time forming device comprises two corrugation forming half cylinders surrounding the EGR pipe. The two corrugation forming half cylinders are correspondingly provided with forming half-cylinder mold combining devices respectively. Corrugation forming half grooves and corrugation top forming holes are formed in the inner walls of the two corrugation forming half cylinders. Corrugation top limiting molds are oppositely arranged on the outer sides of the corrugation forming half cylinders. Corrugation top limiting inserting pieces corresponding to the corrugation forming holes are arranged on the inner walls of the two corrugation top limiting molds respectively. The two corrugation top limiting molds are each connected with a limiting drive device. Forming half cylinder ejecting devices are arranged at the side portions of the two corrugation forming half cylinders respectively. A corrugation pressure forming device is arranged between the two corrugation forming half cylinders. One-time forming of multiple independent corrugations is achieved, consistency of the sizes such as the corrugation outer diameter, the corrugation outer outline and the length is effectively guaranteed, and the reliability of the EGR pipe is improved. Meanwhile, the production efficiency of the EGR pipe is greatly improved. The rejection rate and the assembling stress of the EGR pipe are greatly reduced.

Description

technical field [0001] The invention relates to a multi-corrugation one-time forming device for EGR pipe fittings, and also relates to a multi-corrugation forming process using the device. Background technique [0002] The existing traditional annular corrugation forming process, regardless of the bulging method, is formed one corrugation by one corrugation, which not only has low production efficiency, but also has poor consistency in the outer diameter of each corrugation, corrugation transition R, and corrugation spacing. In particular, the total length tolerance of multiple corrugations can only be controlled within 4-6mm, and due to the uneven deformation during the forming process, it is easy to cause the inner diameter of the tube at the corrugated forming part to be smaller than the original tube inner diameter, resulting in the bending of the core during the bending process. The rod cannot pass through smoothly, and the product structure of the pipe fitting assembly...

AI Technical Summary

Problems solved by technology

[0002] The existing traditional annular corrugation forming process, regardless of the bulging method, is formed one corrugation by one corrugation, which not only has low production efficiency, but also has poor consistency in the outer diameter of each corrugation, corrugation transition R, and corrugation spacing. In particular, the total length tolerance of multiple corrugations can only be controlled within 4-6mm, and due to the uneven deformation during the forming process, it is easy to cause the inner diameter of the tube at the corrugated forming part to be smaller than the original tube inner diameter, resulting in the bending of the core during the bending process. The rod cannot pass through smoothly, and the product structure of the pipe fitting assembly needs to be realized through two bendings. As mentioned above, the corrugation tolerance is large, resulting in poor consistency of the assembly space size and high rejection rate. In the end, the space size is guaranteed by adding a calibration process , not only the production efficiency is low, but also the production cost is increased and the correction causes greater internal stress in the corrugated parts. The assembly is prone to failures such as damage and cracking of the corrugated parts in the engine vibration environment, which greatly reduces the reliability of the assembly.

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