High-end cars and low-end cars are different people and have different opinions, for example, from the various configurations to distinguish:
1. Judging from the skylight.
For the same model, low-end cars may not have sunroofs even if they are high-end models; High-end cars generally have sunroofs in the middle and high range.
2. Judge from the number of airbags.
For low-end cars, low-end cars are often equipped with one airbag or no airbag, and if they are equipped with two airbags, they are often medium and high-end vehicles; For high-end vehicles, the low configuration often has four airbags, and more than four airbags often belong to the medium and high configuration, such as head airbags, knee airbags, etc.;
In general, the low configuration has two airbags, while the medium and high configuration will exceed two; Moreover, the order of airbag installation is the main airbag, auxiliary airbag, side airbag (front, middle and back), head airbag (front, middle and back), knee airbag, etc.
3. Judging from the headlights.
Low-end cars are basically halogen headlights, which cannot be distinguished from the headlights; For high-end cars, the low-end configuration is often halogen headlights, the medium-high configuration is often xenon headlights, and some high-end cars are equipped with LED headlights;
In general cars, xenon headlights are only used on high-end cars; At the same time, it can also be used to distinguish the number of xenon headlights, such as whether the far and low beams are xenon headlights, or only the low beams are xenon headlights.
4. Judging from the function of the seat.
The average low-end car is neither electric nor has a heated seat; In high-end cars, only high-end cars generally have a seat memory function, while low-end cars often only have electric seats, without heating and memory functions;
Generally, there is no electric seat for low-profile vehicles, and the configuration of electric seats often belongs to medium and high-end models; In addition, the number of electric seats, seat heating, and seat memory can also be seen from the level of configuration, and the power seat, heating, and memory functions are easy to see and are not easy to be faked.
5. Judge from the configuration of the center console.
Low-end cars, low-end cars generally only have radios, and CD is often equipped with medium and high-end configurations; High-end cars, high-end models often have navigation, a large central control screen, a centralized system of functions and integration;
General vehicles, low-profile models generally only have CD machines, and the configuration of navigation, central control evaluation often belongs to the medium and high configuration; That is, the center console of the low-profile car is very leaky and does not have many functions.
6. Judging from the air outlet of the rear air conditioner.
Low-end cars, low-end models often only have air conditioning outlets, and can not adjust the size, no other functions, while the middle and high-end models often have a bit of a smoker, air outlet adjustment and other functions;
For high-end cars, the rear exhaust air vents of high-end models are often independent air conditioners, and have sockets for adjusting seat heating and audio. In general cars, the low configuration only has air outlets, cigarette lighters, etc., and the medium and high configurations will be equipped with USB, audio and other functions.
7. Judge from the direction of assistance.
Low-end cars, low-end configuration often has no assistance, only the middle and high-end configuration has assistance, and it is a hydraulic power assist system; For high-end cars, low-end models often use hydraulic power assist systems, while medium and high-end models often have electric power assist systems or speed-up power assist systems;
For general cars, most of the low-profile uses hydraulic power-assist systems, and high-configuration uses electric power-assist systems; In short, from unassisted, hydraulically assisted, electric assisted to steered at speed, the more high-end, the higher the configuration.
8. Judging from the braking system.
Judging from the presence or absence of electronic control systems such as ABS, ASR, ESP, etc., the general vehicle is only equipped with ABS system, while the low-end vehicle has only ABS system.
The above is to distinguish high-end cars from low-end cars in different configurations. There are also brands that distinguish high-end cars from low-end cars.
This article breaks the mold and compares high-end cars with low-end cars from the design details of a fastener.
01 Automobile fuel tank clamp bolt connection
The car fuel tank is the container where the car stores fuel, the only place where fuel is stored on the car fueled by fuel, and it is also the power of the engine**.
The main structure of the automobile fuel tank is composed of a fuel pipe, a box, a gasoline tank cover, a gasoline gauge, a gasoline fuel pump, etc.
02 Types of Car Fuel Tanks
According to the different fuels, fuel tanks can be divided into gasoline tanks and diesel tanks;
According to the different structures, the fuel tank can be divided into bite type fuel tank, aluminum alloy fuel tank, CO2 welded fuel tank, upper and lower butt fuel tank, and seam welded fuel tank at both ends.
Automobile fuel tanks are mostly welded with steel plate stamping parts, and in recent years, metal fuel tanks have been gradually replaced by plastic fuel tanks.
The upper part is equipped with a fuel gauge sensor, an inlet and return oil port, a fuel filler, a warm air oil intake, a vent, and a fuel tank cover; The bottom is equipped with an oil drain screw plug; The tank is fitted with a partition and some tanks now have a gravity valve (see accessories for details) instead of a vent.
The automobile fuel tank will be connected and fixed by a steel belt clamp, as shown in Figure 1.
Figure 103 Bolt connection of fuel tank for low-end cars
The fuel tank clamp connection of the general ordinary model (low-end) is as shown in Figure 2 3 4 5 6, and the bolts are generally M8-88 plus ** blue bolts, due to the assembly, screwed into the internal thread hole, therefore, the bolt design is generally connected by bolts with guide ends. The bolts press directly against the clamp (steel belt) without any buffer in between.
This low-end car fuel tank clamp connection, relatively simple design, low cost, there will be no great torque attenuation when tightening, but because the fuel tank directly acts on the bolt, the force will have a greater impact force, if the design is not good, there will be a risk of loose bolt connection.
However, these bolt designs also did not find any anti-loosening measures for the bolts, the main possible reason is that the fuel tank itself is not heavy, and in addition to the bolt clamp fixation, there are other bolt connections, using M8-8The bolted joints of 8 are strong enough that there will be no possibility of loosening.
Figure 2
Figure 3
Figure 4
Figure 5
Fig. 6 Of course, the fuel tank connection in some Japanese cars will be bolted by M10 (as shown in Fig. 7, 8, 9, 10) to ensure the firmness and reliability of the connection. 
Figure 7
FIGURE 8
Figure 9
FIGURE 1004 Fuel tank clamp connection design for high-end automobiles
High-end cars such as Mercedes-Benz, BMW, Audi, Volvo and other models have adopted a design with shock absorption, as shown in Figure 11 12 13 14Shock-absorbing rubber plastic penetrates the casing in the middle, the height of the casing should be lower than the thickness of the rubber, compress the rubber plastic after the bolt is tightened, make the casing compressed to the sheet metal parts or bolt heads, some models of sheet metal parts out of the casing pipe end contact, some models of casing pipe end contact bolt head.
No matter how it is designed, it is to ensure that the middle sleeve is rigidly connected after the bolt is tightened, so as not to cause torque attenuation and loosening of the bolt.
Because the bolt connection of the fuel tank clamp is made of rubber vibration isolation, which can reduce the load transmitted to the bolts, and also play a good role in shock absorption of the fuel tank.
This shock-absorbing design connection also does not adopt any anti-loosening measures, but because the bolt will rotate when tightened, in order to prevent the casing from rotating with the bolt when tightening, therefore, the bolt connection is generally designed as a bolt and washer assembly, some adopt hexagonal head bolt flattening washer, and some models adopt hexagonal flange surface bolt flattening washer design.
Figure 11, Figure 12
Figure 13, Figure 1405 Summary of Screw's experience
The low-end model fuel tank clamp connection is generally M8 or M10 bolts directly connected to the clamp, in the form of rigid connection, the bolts do not have any anti-loosening measures.
The connection of the fuel tank clamp of high-end models generally adopts the bolt of M8 through the rubber parts or plastic parts and the casing, and finally presses it to the clamp by the casing, which can not only play a role in shock absorption, but also ensure that the bolt connection will not appear torque attenuation. However, the cost of this connection is relatively high, the number of parts increases, and the weight also increases.
The clamp connection of the fuel tank of the general model is directly tightened to the clamp by bolts, which does not require any anti-loosening measures, which can be enough to meet the design requirements, and the cost is relatively low.
It can also be seen from this bolted connection design that the design of the bolted joint, especially the design of the connected parts, can also play a certain cost reduction effect under the premise of meeting the requirements.
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