1. What are the effects of damage to the exhaust pipe muffler? 2. What is the internal structure of the exhaust muffler? 3. Introduction to car exhaust pipe muffler 4. The function of exhaust pipe muffler What is the impact of damage to the exhaust pipe muffler
The middle exhaust pipe muffler is partially damaged. The biggest impact is that the noise will become louder, which will affect the car's performance. Other performance will not be affected; if the rear section of the exhaust pipe is damaged, it will be in trouble. Not only is it noisy, but the exhaust emissions are also not up to standard and must be replaced. Most original cars use this kind of pipe, which mainly relies on the volume change of the grille muffler or the pipe in the pipe to generate a pressure, and this pressure will return to the cylinder. When the engine fires, the piston begins its radial power stroke and the exhaust valve will open before the piston reaches bottom dead center. Effects of damage to the exhaust muffler: 1. If the exhaust muffler is broken, the most obvious symptom is that the engine sound becomes louder; 2. After all, its function is to reduce the noise generated when the engine is working. If a fault occurs, it will naturally not be able to perform its original functions normally, which will have a great impact on driving comfort. 3. But at the same time it does not affect the car. Of course, we can still drive when the muffler is damaged, provided that you can bear the noise of the engine. Through the editor's introduction, I wonder what impact you have on the damage to the exhaust muffler? Is everything okay? I hope the above introduction can be helpful to you. If you want to know more, keep reading other articles on this site! What is the internal structure of the exhaust muffler?
The exhaust muffler generally consists of an exhaust pipe, a connecting screw sleeve, a muffler barrel and a barrel core. The following is an introduction to relevant knowledge about exhaust mufflers: 1. Function: Mufflers refer to airflow ducts with noise transmission that can use pipes and elbows with sound-absorbing linings or pipes that use sudden changes in cross-sectional area and discontinuous acoustic impedance. Noise reduction devices such as these can attenuate or reflect back the noise in the pipeline. 2. Classification: There are many types of mufflers, but based on their muffler mechanisms, they can be divided into six main types: resistive mufflers, resistance mufflers, impedance composite mufflers, micro-perforated plate mufflers, small hole mufflers and active mufflers. . Introduction to automobile exhaust pipe silencers
Automobile exhaust pipe silencers are an important measure to eliminate aerodynamic noise and prevent dynamic noise. Next, I will introduce to you the classification of automobile exhaust pipe mufflers and the working principle of automobile exhaust pipe mufflers.
Classification of automobile exhaust pipe mufflers
1. Resistant muffler
Also known as reflective type, it is used by most original cars and does not require There is a concern that sound-absorbing foam will fail over time, so it is relatively durable. When the resistant muffler is composed of expansion chambers, vibrating chambers and other muffler units internally through pipes, partitions and other components, sound waves are reflected and interfered when propagating, reducing the sound energy to achieve the purpose of silencing. Resistive mufflers have a limited silencing frequency band. They usually have good silencing effects in low and mid-frequency bands, but poor high-frequency silencing effects. Resistive mufflers are mostly used in trucks.
2. Resistive mufflers
The shapes are different and the airflow directions are also different. It is a muffler that fills sound-absorbing materials around the pipe through which the internal exhaust gas passes to absorb sound energy to achieve the purpose of silencing. It has good silencing effect on medium and high frequencies. It is rarely used simply as a car exhaust muffler. It is usually used in combination with a resistant muffler. It is a porous tube and sound-absorbing fiber. When the exhaust gas contacts the fiber through the porous tube, the latter vibrates and generates heat energy due to friction and viscosity. The noise is converted in this process, so it is also called the sound-absorbing process. The resistance-shaped muffler has the characteristics of small size, so most original cars like to use the resistance-shaped muffler in the middle drum. If you want to give full play to its muffler function, the installation position is generally closer to the engine direction. A large number of tests have shown that the resistive muffler's suppression effect on engine mid- and high-frequency noise is better than its effect on mid- and low-frequency noise. In the same situation, the performance of resistant exhaust is exactly opposite to that of resistance.
3. Impedance composite muffler
It is characterized by having both an expansion chamber and sound-absorbing fibers. A muffler composed of a combination of resistant muffler units and sound-absorbing materials, which combines the characteristics of the first two mufflers. , has a wide range of applications and is more flexible in volume, but the cost is also relatively high.
The working principle of the automobile exhaust pipe muffler
The principle of the muffler is that the exhaust pipe is composed of two pipes with different lengths. The two pipes are separated first and then meet. Since the length difference between the two pipes is equal to half the wavelength of the sound waves emitted by the car, the two columns of sound waves cancel each other out when they interfere when superimposed, thus weakening the sound intensity and reducing the sound, thus achieving a silencing effect.
Resistive mufflers mainly use porous sound-absorbing materials to reduce noise. The sound-absorbing material is fixed on the inner wall of the air flow channel or arranged in a certain way in the pipe to form a resistive muffler. When sound waves enter the resistive muffler, part of the sound energy is converted into heat energy by friction in the pores of the porous material and is dissipated, weakening the sound waves passing through the muffler. A resistive muffler is like a purely resistive circuit electrically, and the sound-absorbing material is similar to a resistor. Therefore, people call this type of muffler a resistive muffler. The resistive muffler has a good silencing effect on medium and high frequencies, but a poor silencing effect on low frequencies.
The resistant muffler is composed of tubes and chambers with sudden interfaces. It is like an acoustic filter, similar to an electrical filter. Each small chamber with a tube is a mesh of the filter. The air mass in the tube is equivalent to the electrical inductance and resistance, which are called sound mass and sound resistance. The volume of air in the chamber is equivalent to the electrical capacitance, which is called acoustic compliance.
Similar to an electrical filter, each chamber with tubes has its own natural frequency. When sound waves containing various frequency components enter the first short tube, only sound waves with certain frequencies near the natural frequency of the first mesh can pass through the mesh and reach the second short tube mouth, while those with other frequencies It is impossible for sound waves to pass through the mesh. They can only be reflected back and forth in the small room. Therefore, we call this structure that has the function of filtering sound waves an acoustic filter. By selecting the appropriate combination of tubes and chambers, the noise of certain frequency components can be filtered out, thereby achieving the purpose of silencing. Resistive mufflers are suitable for eliminating mid- and low-frequency noise. Exhaust pipe muffler function
Muffler Exhaust muffler, literally exhaust muffler, is a specific machine that eliminates sound, right exhaust muffler? 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 mdash mdash principle
In the "Wave Interference" in Chapter 9 "Mechanical Waves" of high school physics, the principle of the exhaust muffler is briefly introduced: namely 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 mdash 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 muffling principle and structure, automobile mufflers can include three types: resistance muffler, resistance muffler and impedance composite muffler.
1. Resistant muffler Resistant 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 exhaust muffler!
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.
Avoid discoloration of the muffler.
1. When it is difficult to start the car when it is cold 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 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.