Automobile Exhaust Pipe Lost Wax Investment Casting

Product Introduction

Automobile exhaust bellows, also known as automobile exhaust pipe hose, are installed in the exhaust pipe between the engine exhaust branch pipe and the muffler, so that the entire exhaust system is flexibly connected, thereby reducing vibration and noise, and is convenient. The function of installing and prolonging the life of the exhaust muffler system. It is mainly used for light vehicles, miniature vehicles, and passenger cars. Its structure is that the double-layer bellows are covered with steel wire mesh sleeves, and the straight edge sections at both ends are covered with snap rings. In order to make the noise reduction effect better, the bellows can be equipped with a telescopic knot or netting.

Material: The main material is stainless steel SUS304, and the ferrule and connecting pipe can be made of stainless steel or aluminized steel.

Material selection

1. Ferritic stainless steel has become the material of choice for automobile exhaust pipe materials.

1) Ferritic stainless steel does not contain or contain precious metal Ni, and the cost of raw materials is low;

2) Ferritic stainless steel has a small thermal expansion coefficient, high thermal conductivity, good high-temperature oxidation resistance under repeated heating and cooling conditions, and good pitting corrosion resistance;

3) Compared with austenitic stainless steel, ferritic stainless steel has good resistance to chloride, stress corrosion, and intergranular corrosion;

4) Ferritic stainless steel stabilized by Nb and Ti has excellent creep resistance;

5) Ferritic stainless steel has low resilience during cold forming.

2. Selection of stainless steel types for automobile exhaust pipes

The principle is the same as the original factory, but the sound will be better than the original factory. Most of the original cars use this kind of tube, mainly relying on the volume change of the grating muffler or the tube in the tube to generate a pressure that will return to the cylinder. The piston opens before it reaches the bottom dead center. At this time, the back pressure in the pipe will block the exhaust gas from rushing out, so that the mixture can be completely burned. However, if the back pressure is too strong, the exhaust gas cannot be completely discharged from the cylinder, causing the exhaust gas and the mixture to burn together to reduce the combustion efficiency... Of course, the most direct effect is the horsepower output.

Advantages: low noise, good low-speed torque

Disadvantage: Exhaust gas cannot be discharged quickly at high speed, which affects engine power output

Volume: Low (one star)

1) Half-back pressure tube

This kind of pipe has lower back pressure strength and better exhaust smoothness than the back pressure pipe. Simply put, Automobile exhaust pipe lost wax investment casting starts with a moderate back pressure between the back pressure pipe and the straight-through pipe. Torque exhaust smoothness is better than that of the return pressure pipe, and of course, the torque at medium and high speeds is also greater than that of the return pressure pipe.

Advantages: Good torque performance at mid-range and tail speeds

Disadvantages: Loud noise (two stars) Volume: Louder

2) Straight pipe

Acceleration is better than that of the back pressure pipe, but the biggest disadvantage is that it is very noisy, so loud that the "police cup" will chase you. big.

Advantages: smooth exhaust, strong torque at high speed

Disadvantages: soft power at low speed, loud noise (some people say it is easy to burn out the valve, but I don't know if it is true)

Volume: super loud... (four stars)

3) Half-through pipe

In fact, the semi-straight-through pipe is the same as the half-back pressure pipe, but the exhaust diameter is larger than that of the half-back pressure pipe. Advantages: the starting torque is lower than that of the half-back pressure pipe, but the torque is larger at medium and high speeds

4) Semi-double valve variable exhaust

A variable exhaust system was attached to the exhaust pipe and a side pipe was added. When one pipe is fully opened, the other pipe is completely closed. Compared with single-valve variable exhaust, it has a better sound effect. When the opening is one-third, the sound effect is more single-valve exhaust. The gas is basically the same. The sound can be switched on and off, and the exhaust that can change the volume of the sound has been achieved.

5) Variable exhaust pipe

Valve-controlled exhaust for optimum sound and performance.

Detection Systems

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