[XCAR Technology Original]

　　　　Since the day when the automobile was invented, a "bad guy" who followed the vehicle along with it also appeared at the same time, and that was noise. In order to give users the best driving experience, in the past decades or even hundreds of years, car manufacturers have been fighting the "bad guy" of noise endlessly.

　　　　Now, automobile manufacturers will adjust their vehicles through strict noise control standards to ensure that each vehicle can achieve a good level of noise and vibration suppression when leaving the factory. Recently, the author was lucky enough to participate in and experience the NVH test of Changan Auchan. In the test, I experienced Changan Automobile’s emphasis on the development of Auchan’s NVH. So what "magic weapons" did Changan Automobile use to control Auchan’s NVH? Let’s continue to look down.

1. What is NVH?

　　　　NVH is the abbreviation of Noise, Vibration and Harshness. Noise and vibration are easy to understand. To put it bluntly, the roughness of acoustic vibration is those uncomfortable feelings, such as harsh, roaring sound and uneven vibration. NVH is the core index to measure the comfort and quality of a car, and the feeling it brings to users is also the most direct.

　　　　According to statistics, four of the top 10 complaints of consumers about automobiles are about NVH, namely, engine noise, tire noise, wind noise and body noise. About one-third of the complaints of the whole vehicle are related to the NVH problem of vehicles, and nearly 20% of the research and development expenses of major car companies are spent on solving the NVH problem of vehicles.

　　　　It can be seen that NVH is very important for both the vehicle itself and the brand, because it can give consumers the most intuitive impression and directly affect consumers’ perception of the "texture" of the vehicle, so it is an important task for all car companies to develop NVH well. At present, NVH is mainly determined by these points: government regulations, customer requirements, company needs and technical capabilities, competing models.

　　　　At present, automobile sound control has gone through three development stages:

　　　　1. Reduce noise: solve the error state of NVH and reduce noise.

　　　　2. Sound quality control: make the sound comfortable, meet the requirements of specific customer groups, and the sound of the vehicle model is personalized.

　　　　3, sound quality DNA: the model is personalized and the brand voice is differentiated.

　　　　Through the above three stages, the transition from noise control to sound design has been realized.

Second, the control of Auchan NVH

　　　　The vehicle noise that we can hear is usually generated by the noise source and transmitted through the channel to reach our ears. Generally, noise sources and transmission channels are controlled to reduce noise. Simply put, this is the transmission of sound in physics, and noise reduction should be suppressed from the source and propagation.

　　　　Generally speaking, vehicle noise is mainly divided intoAir soundandStructural sound：

　　　　Air sound sources: engine radiation noise, air inlet noise, air outlet noise, tire radiation noise, etc.

　　　　Structural sound sources: engine vibration, exhaust hook vibration, chassis vibration, transmission bearing vibration and so on.

　　　　Two kinds of sound sources are transmitted through the car body, and the air sound source reaches our ears through the car body barrier and car body sound absorption; The structural sound source reaches our ears through the body structure, bracket and vibration isolator. These two kinds of sound sources are transmitted and attenuated to form the interior noise together.

　　　　After understanding the generation of noise, let’s see what anti-noise and vibration capabilities Auchan has. Auchan, as an MPV model with high hopes from Chang ‘an, naturally invested a lot in NVH. We found many NVH development achievements on Auchan’s car body.

　　　　In the overall design, Auchan has optimized the acoustic vibration transmission structure such as modeling, powertrain, car body and chassis suspension, so as to reduce the noise source and isolate the transmission of vibration and noise outside the car.

　　　　The first is engine noise suppression. Auchan’s 1.5L naturally aspirated engine has done a number of treatments in silence, including valves, fuel injectors, air intake systems, silent pulleys, etc., which reduced the engine noise at the source. According to official data, the idle noise value of Auchan is only 39 decibels.

　　　　Auchan soundproofed the engine to reduce the noise from being transmitted into the cab through the front wall, fender, hood and other channels. The composite sound insulation and absorption material is pasted under the hood, which can absorb and reduce the noise of the engine and suppress the vibration of the hood.

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Changan Auchan X5 design is dynamic and fashionable. The front face adopts a large-area air intake grille design, and the sharp chrome trim and black grid match, showing a strong sporty atmosphere. The LED headlights on both sides of the front of the car are sharp and integrated with the front grille, making the overall style more harmonious and unified. The body lines are smooth, and the waistline extends from the front to the rear, creating a dynamic visual effect. On the whole, the design of Changan Auchan X5 is both fashionable and powerful.

Changan Auchan X5 has a body size of 4490*1860*1580mm, a wheelbase of 2710mm, a front wheel track of 1580mm and a rear wheel track of 1595mm. The body lines are smooth and dynamic, and the tyre size is 225/50 R18. The wheels are fashionable and dynamic.

For the interior, Changan Auchan X5 adopts a simple and fashionable design style. The center console is equipped with a 10.25-inch touch screen and supports USB interface, so that entertainment and navigation functions are available. The steering wheel is made of leather, which provides better grip and comfort, and supports manual adjustment up and down to meet the driving needs of different drivers. In terms of seats, the main driver’s seat supports front and rear adjustment, backrest adjustment and height adjustment, while the co-pilot’s seat also supports front and rear and backrest adjustment. The rear seats can be laid down in proportion, further enhancing the flexibility of storage space. The seat material is a mix of leather and fabric, which is both comfortable and durable.

Changan Auchan X5 is equipped with a 1.5T L4 engine, with a maximum power of 138kW and a maximum torque of 300N m. With the 7-speed wet dual-clutch gearbox, it provides excellent power performance and smooth shifting experience.

To sum up, car home car owners have a very positive evaluation of Changan Auchan X5. He praised the sports design of the car, thinking that it is not only cheap, but also has a unique personality and design sense. In addition, he also emphasized that the chassis of this car has excellent training and excellent handling performance, making the driving experience both comfortable and sporty. The owner also affirmed the power and face value of Changan Auchan X5, and thought that these aspects were excellent. The owner hopes that this car can continue to maintain its excellent performance and accompany itself for a long time.

There are many choices of cars now, as we said today. Let’s take a look at it together.

Let’s take a look at the appearance of Weilai ET7 first. The design of Weilai ET7 front is very capable and very recognizable. Coupled with exquisite headlights, it is full of fashion sense. The car is equipped with LED daytime running lights, front fog lights, automatic opening and closing, adaptive far and near light, delayed closing and so on. Coming to the side of the car, the size of the car body is 5101 mm * 1987 mm * 1509 mm. The car adopts dynamic and lively lines, giving people a feeling of very young personality. With large-sized thick-walled tires, the shape is quite cold. In terms of the rear end, the tail line of Weilai ET7 is simple, and the taillights give people a very cold feeling. Overall, it is relatively simple and fashionable.

When I came into the car, the interior adopted a sporty design, and the overall design was very individual. The steering wheel design of this car is very elegant, and it is made of genuine leather, which gives a good grip experience. From the central control point of view, the design of the center console is reasonable, which makes the interior design quite layered and cool. The dashboard and seats give people a good feeling, too. Let’s take a look. The dashboard of this car presents a young and fashionable design style with a sense of science and technology. The car uses leather seats, the seats are wrapped in place, the materials are exquisite and the ride is comfortable.

Weilai ET7 matches the gearbox, which is 480KW and 850N.m, and its power performance is good.

Equipped with car networking, driving mode selection, remote control key, Bluetooth key, NFC/RFID key, UWB digital key, indoor atmosphere light, traction control (ASR/TCS, etc.) and other configurations, it has rich functions and greatly improves its convenience of use.

Do you have a lot of ideas after reading today’s story? The model class introduced today is the most considered class when many people buy their first car, mainly because the size of this class is moderate and the price is reasonable.