How to control the sound of the car engine?

Do sound insulation, cabin firewall, front canopy insulation cotton, front wheel fender sound insulation.

The specific methods of engine compartment noise reduction are: sound absorption - absorbing sound energy with microplates and foam; Vibration damping – isolate the vibration source from the structure with a shock absorber; Containment – use a soundproof cover or other soundproofing device to enclose the noise to make it difficult to spread; Damping – converts mechanical kinetic energy into heat energy and dissipates it.

The materials selected must meet the requirements of sound insulation, sound absorption, vibration reduction and heat insulation. The methods of sound insulation and vibration reduction treatment of the engine are: by installing vibration reduction pads on the engine and water radiator fixing brackets, the mechanical energy is converted into heat energy; The interior of the engine compartment should be avoided as much as possible, and the method of porous material and damping layer can be used; Measures should be taken to close all the slats of the skeleton on the body to avoid diffraction waves.

Solving the noise of the vehicle engine is a technical problem involving all aspects of the whole machine, including the structure, materials, mass distribution, process level, assembly tightness and so on. Manufacturers in the vehicle engine structure to take active measures to prevent and control noise including: the use of vibration absorption, sound insulation technology, improve the structure of the car, in a certain distance from the sound source to set up sound insulation panels, mufflers, the use of rear-suspension engines for buses, improve the structure of mufflers and so on.

Hello dear! Thank you for waiting, like the sound of the engine can not be adjusted, because the sound of the engine is mainly from the sound of the engine piston movement, and the sound of this engine cannot be adjusted. But the sound of the exhaust like the engine can be adjusted.

The use of different exhaust pipe lengths and different mufflers can make the exhaust sound of the engine into different types. Therefore, the engine exhaust sound of many models will have different types, mainly because the exhaust pipe design of the engine is different, but the sound of the engine itself cannot be adjusted. Kiss!

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Categories: Education Science >> Science and Technology >> Engineering Technology Science Analysis: The engine and body of a car make noise everywhere.

1. The sound of deflagration of fuel work.

2. The grinding sound of the linear motion of the piston.

3. The grinding sound of crankshaft and connecting rod.

4. The wind sound of the fan.

5. The collision sound of the eccentric shaft and the intake and exhaust valves.

6. The transmission sound of each gear of the gearbox and the sound of shifting.

7. The grinding sound of the clutch.

8. The sound of universal joints and transmission shafts.

9. The sound of the gear of the differential.

10. The sound of half shaft and wheel bearing.

11. The sound of grinding between the tires and the ground.

12. Exhaust emission silencer sounds.

13. The vibration sound of the whole car.

14. The rotation sound of the generator.

A normal car engine should be without a screeching sound during the start of the engine, and the engine idle sound is even. There may be a clicking sound when the cool car starts, and the sound weakens and disappears after the engine warms up, which is a normal engine sound. Here's why your car's engine is louder:

1. The engine has a kicking sound, like the sound of a pencil hitting the table. The possible cause is that there is dirt inside the engine, it is recommended to change the oil engine and filter the engine; 2. When the acceleration is normal during driving, the ignition is normal, but when driving at a constant speed, it is found that the engine speed is too high, but the speed still does not seem to be able to rise. Try checking the coolant, and it is also possible that there is a problem with the ignition time setting that can also cause these symptoms; 3. The engine makes a clicking sound when idling, as if something is hitting the metal.

It may be that the cylinder valve can be changed by adjusting the valve; 4. When the engine is accelerating, there will be a whirring sound or deceleration. The possible reason is that the power steering oil is missing, and the generator bearing may be damaged. Problems with power steering pumps and water pumps will produce similar noises; 5. When you step on the accelerator pedal, you will hear a banging sound coming out of the exhaust pipe, and the sound may not be very loud, and the car will not be abnormal when driving, and the fuel consumption will increase.

It is advisable to check whether the muffler and exhaust pipe are damaged.

Car noise comes from many places, such as the engine, transmission, body sheet metal parts, etcEngine noise is a very important factor。More than 100,000 cars can be said to be a better option, with a certain horsepower output and comfortable to sit in the car, but the car will have abnormal noise, which we call noise, because the sound exceeds the limit of what our ears feel comfortable with. Car noise comes from many places, such as engine, transmission, body sheet metal parts, etc., among which engine noise is a very important influencing factor.

Classification of Engine Noise Class 1 Engine noise level This is the vibration caused by the combustion pressure and the inertial force of rotating parts such as pistons and crankshafts, including up and down vertical vibration force, horizontal oscillating vibration force, and side-to-side rolling force. For the familiar four-cylinder engine, the vertical and horizontal oscillating forces are the main ones of the first type of noise. The noise level of the second type of engine is mainly the engine output device (solenoid valve, motor), timing mechanism (transmission belt, timing belt, chain), and the unit attached to the components (generator, air conditioning compressor, water pump, steering power pump), etc.

We know that the propagation of sound is mainly to control engine noise through the sound source, sound medium and audience, so as to reduce the noise of the noise source in the air.

Reduce noise from noise sources and improve the structure and materials of moving parts. When the engine is working, the crankshaft is driven by the piston moving up and down, so we can start with that. When the piston moves up and down, if the gap between the piston and the cylinder wall is too large, the piston movement will produce the cylinder knocking sound.

In this case, the distance can be shortened appropriately, or the piston pin offset can be installed to reduce the knocking sound. For the gears that transmit the power of the crankshaft and camshaft, we can improve the machining accuracy of the gears, change the material of the gears, the meshing of gears with gears, and improve the tightness of the valve timing cover.

The engine has components such as camshafts, columns, valve groups, etc., and the use of good lubricating oil can reduce the noise generated by the operation of these components. The use of hydraulic columns can reduce the effect of valve clearance and reduce the sound of the rocker arm in contact with the valve; Shortening the length of the actuator is also a way to reduce the mass of the system and the degree of rigidity, which can increase the intermediate gear between the camshaft and the crankshaft. Improved exhaust system.

By re-adding part of the exhaust gases from the engine to the combustion chamber through the exhaust pipe, it not only reduces the concentration of nitrogen oxides, but also reduces the combustion temperature of the engine. Since the added nitrogen oxides cannot be burned, this increases the maximum pressure in the cylinder, which is beneficial for reducing the noise of the engine.

Engine noise is mainly divided into Category 1 and Category 2 noise levels. Ways to reduce engine noise include improving the structure and materials of moving parts, reducing combustion noise, and reducing air transmission noise. The installation of a turbocharger can increase the density, temperature and pressure of the incoming air, thereby improving the ignition conditions of the mixture, shortening the ignition delay period, making the engine run more stable and reducing noise

First of all, see if the oil of the engine is dirty, and then check whether the engine and compressor are worn, or do firewall and sound insulation cotton treatment, and dismantle the group so that the brigade can alleviate this problem.

I think the best thing to do is to do a good job of soundproofing the engine compartment, so that the noise problem can be completely solved.

It is necessary to improve the quality of the oil, but also to pay attention to the fixation of the engine, and sometimes to go to the car regularly to avoid loose parts.