Water swelling forming technology of silencer of vehicle

Abstract

The invention discloses a water swelling forming technology of a silencer of a vehicle. The water swelling forming technology is characterized by comprising the following steps that a stainless steelpipe is cut off and burrs are removed; the stainless steel pipe is subjected to pipe bending based on appearance of a product; a bent pipe the subjected to solid melting process, and two ends of the bent pipe are formed by plugs to maintain the shape of the outer circle of the two ends; a cold pressing mold is adopted to one-time flatten the middle portion by a hydraulic machine, wherein the pressure applied by the hydraulic machine is greater than 315 tons; the product is subjected to solid melting process again; a blank material is positioned into a water swelling mold, and a water swellingmachine is used for pressing the mold; two pressurization cylinders push punches to extrude the pipe at two ends of the mold; saponification solution at 20MPa pressure is injected into inner holes ofthe punches; and after water swelling forming, a workpiece is cut off from the middle portion to form two parts. Parameters of water swelling forming are that pressure applied by the water swelling machine is 315 tons, pressure intensity is 20MPa, the output water pressure of the pressurization cylinders is greater than 160MPa, and the output pressure of left and right cylinders is greater than 20MPa.

Description

technical field [0001] The invention relates to the field of water-expansion molding, in particular to a water-expansion molding process for an automobile muffler. Background technique [0002] The muffler for automobiles is an important part of the car. Because the muffler works at high temperature for a long time, it needs to use high temperature resistant parts. At the same time, because the national emission requirements are becoming more and more stringent, the exhaust gas in the muffler of the car must be For post-treatment, urea solution is usually used to remove harmful substances in the gas. Because urea is corrosive, the material requirements for the muffler are relatively high. The structure of the muffler is different according to the vehicle model. It has many types of appearance and is complex in direction. In order to meet the compact requirements of the vehicle, most of the shapes are irregular. However, the existing technology generally adopts stretch formin...

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Problems solved by technology

[0002] The muffler for automobiles is an important part of the car. Because the muffler works at high temperature for a long time, it needs to use high temperature resistant parts. At the same time, because the national emission requirements are becoming more and more stringent, the exhaust gas in the muffler of the car must be For post-treatment, urea solution is usually used to remove harmful substances in the gas. Because urea is corrosive, the material requirements for the muffler are relatively high. The structure of the muffler is different according to the vehicle model. It has many types of appearance and is complex in direction. In order to meet the compact requirements of the vehicle, most of the shapes are irregular. However, the existing technology generally adopts stretch forming, and for For irregular switches, tailor welding is generally used to weld multiple regular products into an integral part. The disadvantage of the existing technology is that because the wall of the general product is very thin, the tailor welded part is easy to crack, and the welding The requirements are high, the manufacturing precision of multiple product combinations is high, and a large number of tooling is required to ensure the precision requirements of the product combination, the production process is complicated, the product appearance is not good, and only some products with simple structure can be made, which is relatively complicated The products cannot be completed, most of the parts can only be made by precision casting, high energy consumption, high cost, complex process, long production cycle, short product life, and difficult to guarantee accuracy

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