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Distinguish High-End and Low-End Cars from the Detailed Design of Fastener Connection

Jul. 13, 2020

Different people distinguish between high-end and low-end cars and have different views. Pan Head Screws supplier breaks the routine and compares high-end and low-end cars from the design details of a fastener.

Automobile fuel tank clamp bolt connection

A car fuel tank is a container for storing fuel in a car. It is the only place on a car that uses fuel as fuel to store fuel and is also the source of power for the engine.

The main structure of an automobile fuel tank is composed of a fuel pipe, a tank body, a gasoline tank cover, a gasoline meter, and a gasoline pump.

Type of car fuel tank

According to different fuels, fuel tanks can be divided into gasoline tanks and diesel tanks; according to different structures, fuel tanks can be divided into bite type fuel tanks, aluminum alloy type fuel tanks, CO2 welded fuel tanks, upper and lower butt joint fuel tanks, and welded fuel tanks at both ends.

Automobile fuel tanks are mostly welded with thin steel stampings. In recent years, metal fuel tanks have been gradually replaced by plastic fuel tanks.

The upper part is equipped with an oil gauge sensor, an oil inlet, and a gas outlet, a fuel filler, a warm air intake, a vent, and a fuel tank cap; the bottom is equipped with a drain plug; the tank is equipped with a partition, and some oil tanks now have gravity valves ( See attachment for details) instead of the vent.

Non Standard Round Bolts

Non Standard Round Bolts

The car's fuel tank will be fixed by a steel band clamp.

Low-end vehicle fuel tank bolt connection

Generally, the fuel tank clamp connection of the ordinary model (low end), the bolt is generally M8-8.8 enlarged flange surface bolt. Because it is screwed into the internally threaded hole during assembly, the bolt design generally uses a bolt connection with a guide end. The bolt directly compresses the clamp (steel belt) without any cushioning device in the middle.

This kind of low-end car fuel tank clamp connection is relatively simple in design and low in 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 large impact force. If the design is not good, there will be a risk of loose bolt connections.

However, these bolt designs did not find any anti-loosening measures for the bolts. The main possible reason is that the fuel tank itself is not heavy and there are other bolt connections besides the bolt clamps. The bolt connection using M8-8.8 is already strong enough. , There will be no possibility of loosening.

Of course, some Japanese cars will use the M10 bolt connection for the fuel tank connection, which will ensure the firmness and reliability of the connection.

High-end car fuel tank clamp connection design

High-end cars such as Mercedes-Benz, BMW, Audi, VOLVO, and other models all adopt a design with shock absorption. The shock-absorbing rubber/plastic is inserted into the sleeve. The height of the sleeve is lower than the thickness of the rubber. After the bolt is tightened, the rubber is compressed/ Plastic, so that the casing is pressed tightly under the sheet metal parts or bolt heads, some models of sheet metal parts come out of the casing tube end contact, and some models have the casing tube end contact the bolt head.

Regardless of the design, it is ensured that the intermediate sleeve is rigidly connected after the bolt is tightened so that the torque of the bolt is not damped and loosened.

The rubber vibration isolation is used for the connection of the oil tank clamp bolts, which can reduce the load transmitted to the bolts, and also plays a good role in damping the oil tank.

This damping design connection does not use any anti-loosening measures, but because the bolt will rotate when tightened, in order to prevent the casing from rotating with the bolt during tightening, the bolt connection is generally designed as a bolt and washer assembly, and some use a hexagon Head bolts with flat washers, some models use the design of hexagon flange bolts with flat washers.

to sum up

The low-end model fuel tank clamp connection is generally M8 or M10 bolts directly connected to the clamp, using a rigid connection, the bolt does not have any anti-loosening measures.

High-end model fuel tank clamp connection generally uses M8 bolts to pass through rubber parts or plastic parts and casing, and finally presses the casing to the clamp, which can not only play a shock-absorbing role 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 connection of the fuel tank clamp of the general vehicle model is directly screwed to the clamp without any anti-loosening measures. It can already meet the design requirements and the cost is relatively low.

It can also be seen from the design of this bolt connection that the design of the Non Standard Round Bolts connection, especially the design of the connected parts, can also achieve a certain cost reduction under the premise of meeting the effect of the requirements.