Water-expansion molding process of a muffler for automobiles

Abstract

The invention discloses a water-swelling molding process for an automobile muffler, which is characterized in that it comprises the following process steps: cutting stainless steel pipes and removing burrs; and bending the stainless steel pipe fittings according to the appearance of the product with a pipe bending machine. Solid-melt the bent pipe fittings, and then shape the two ends of the pipe fittings with plugs to keep the outer circle shape of the two ends unchanged, and then use a cold pressing mold to flatten the middle part at one time with a hydraulic press, and the hydraulic press exerts a pressure greater than 315 tons; after solid-melting the product again, put the billet into the water-expanding mold, and use the water-expanding machine to apply pressure to the mold. Two pressurized cylinders at both ends of the mold push the punch to squeeze the pipe fittings. Inject saponified liquid with a pressure of 20MPa. After water-expansion molding, cut the workpiece from the middle to form two identical semi-finished products. The forming parameters of the water-expansion machine are set as follows: pressure applied by the water-expansion machine: 315 tons, pressure 20MPa; two booster cylinders The output pressure 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...

AI Technical Summary

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

Images