A muffler, literally, is a specific machine that eliminates sound, right? Car exhaust mufflers are key components in driving noise. Countries around the world basically have strict regulations on noise limits for various types of vehicles. The function of the exhaust muffler is to eliminate noise by reducing and attenuating the pulsation of exhaust pressure. It is such a device designed to reduce exhaust noise. Let’s take a look at exhaust mufflers using our car editor.
Exhaust pipe muffler amp; Its exhaust pipe is composed of two pipes of different lengths, which first separate and then meet. Since the difference in length between the two tubes is equal to half the wavelength of the sound waves emitted by the car, when the two columns of sound waves interfere with each other when superimposed, the sound intensity will be reduced and the sound will also be reduced, thus achieving a silencing effect.
According to the interference principle, the exhaust muffler has two basic silencing methods: absorption and reflection. The absorption muffler reduces the energy of exhaust gas through the friction of sound-absorbing materials such as glass fiber, steel fiber, asbestos, etc.; the reflection muffler has multiple harmonic cavities connected in series, and the harmonic cavities are connected to porous reflection tubes of different lengths, and the exhaust gas circulates in the harmonic The wave cavity is reflected, collided, expanded and cooled multiple times to reduce its pressure and reduce vibration and energy.
Exhaust pipe muffler&mdashamp;mdash type
In fact, most exhaust mufflers are designed on cars with the help of different combinations of muffling principles. At the same time, in small buses with higher comfort requirements, multiple mufflers can be used for multi-level noise reduction and noise reduction adjustment. According to the muffler principle and structure, automobile mufflers can include three types: resistance muffler, resistance muffler and impedance composite muffler.
1. Resistant muffler Resistive muffler refers to various muffling units such as expansion chamber and vibration chamber. , composed of pipes, partitions, etc. , in which sound waves are reflected and interfered during the propagation process, reducing the sound energy to achieve the purpose of silencing. Resistant mufflers have a limited silencing frequency band. Generally speaking, they have good noise cancellation effect in the mid-low frequency band and poor noise cancellation effect in the high frequency band. Resistant mufflers are often used on trucks.
2. Resistor muffler E is a muffler in which sound-absorbing materials are filled around the pipe through which the internal exhaust gas passes to absorb sound energy to achieve the purpose of silencing. It has a good attenuation effect on mid-to-high frequencies and is rarely used as a car exhaust muffler, so it is usually used in combination with a reaction muffler.
3. The impedance composite muffler is a muffler composed of a resistance muffler unit and a sound-absorbing material. It has the same characteristics of a resistance muffler and a resistance muffler. Basically, it has a very good silencing effect on low, medium and high frequency noise.
Exhaust pipe muffler&mdash&mdash maintenance
Avoid muffler corrosion.
1. Prevent water from entering the inside of the muffler. When driving or washing the car on rainy days, avoid water entering the muffler. When there is water in the muffler, the engine should be started and idle for at least 10 minutes to drain the accumulated water inside as much as possible. This is important!
2. It is recommended to apply anti-rust oil inside the muffler. The specific refueling measures are as follows:
1) Remove the muffler and block the drainage hole at the lowest point in the middle of the muffler;
2) Add about 50 ml of anti-rust oil from the flange connecting the muffler to the engine, shake the muffler to allow the anti-rust oil to enter the cylinder evenly, and then install the muffler; 3) After the engine is started, due to the gradual increase in the temperature of the muffler, the anti-rust oil will Rusty oil will evaporate when heated, and blue smoke will emit from the tail of the muffler. However, after driving 20 kilometers, the blue smoke will disappear. After the blue smoke disappears, unblock the drain hole; 4) It is recommended that the new car be refueled and maintained once after it is registered, and usually every six months.
Prevent discoloration of the muffler.
1. When it is difficult to start a cold car in winter, close the choke valve and start the engine. Be careful to open the choke valve immediately after the car is warmed up.
When the throttle valve is closed, it is prohibited to drive at high speed for a long time;
2. It is prohibited to install a windshield or other decorative items in front of the engine and muffler when riding a bicycle, which will affect the heat dissipation of the engine and muffler;
3. Do not drive with heavy load for a long time, as this will basically cause damage to the engine and muffler.
4. Do not press the accelerator hard at high speed for a long time;
5. When there is oil on the surface of the muffler, the surface color will change into yellow, blue, etc. After heating. In addition, when there is a lot of dirt and other dirt on the surface of the muffler, please clean it immediately to avoid affecting its heat dissipation;
6. When installing the muffler, pay attention to the muffler pad being installed in place and tightened well to avoid air leakage. It affects the effect of the muffler and causes the muffler interface to turn yellow;
7. Engine valve clearance, carburetor, air filter, etc. Adjustments and cleaning should be made immediately according to the vehicle's instructions for use. For example, if the valve clearance is too thick or too thin, it will basically cause combustion and cause discoloration of the muffler.
The muffler plays a very important role in the exhaust pipe and plays a decisive role. Exhaust pipe mufflers play a key role in reducing engine exhaust noise and enabling safe and effective discharge of high-temperature exhaust gases. As a part of the exhaust pipe, the muffler should ensure smooth exhaust, low resistance, and sufficient strength. The muffler needs to withstand high-temperature exhaust gases of 500°C to 700°C to ensure that the muffler will not be damaged or lose its muffling effect within the specified driving range of the car. After reading the car editor's brief introduction to the exhaust pipe muffler, I hope my friends can help me.
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