Automobile Shock absorber system is really so important?
First, the existence of automobile shock absorption system
In order to cushion the unevenness of the road surface, make driving more comfortable.
Keep the tires in contact with the ground when driving on uneven roads.
For players, there is only one purpose of modifying the suspension system to improve correctability. Before talking about shock absorbers, let's talk about springs first. It is easier for everyone to understand the shock absorption system.
Second, the working principle of shock absorption spring
Since there are too many things in this part that do not need us to understand, try to use the easy word to express the core of the principle. Coil springs are the most common springs used in current suspension systems, because they are easy to make, have high performance and efficiency, and are inexpensive. The force exerted by the spring. It is more important to keep the tires in continuous contact with the road surface during the vibration elimination process to maintain the tracking of the car. And how to improve the continuous contact is the first consideration of the tuning.
If you use a too hard spring when you modify it, you will start another car when you encounter uneven roads, and the friction between the tire and the ground will be lost. If you use a too soft spring, it will be easily and quickly compressed, making the shock absorber The itinerary is exhausted, and it is easy to lose track when turning. Therefore, the choice of the spring depends on the road surface used: the road above it can be used harder, and there is another type called "progressive spring", which can increase the elastic coefficient with the compression of the spring, but because of the considerable manufacturing Difficult and uncommon. " ** No more here.
The elastic K value of the spring, this is a parameter to determine the spring. Elastic K value ** refers to the coefficient of elasticity of the spring, the unit is kgf / m, the number of K, the stronger the energy reserve when the spring is compressed. Excellent springs everyone will definitely use high-quality spring equipment for processing. Automobiles already belong to the mainstream tools of human transportation, so when customers choose a car, the main parts and performance of the car are the key factors for them to make a decision. The quality of the various springs in the car also plays a key role in the performance and accompany of the car.
Materials and heat treatment processes for making springs
When manufacturing springs, metal elements such as silicon, manganese, chromium, vanadium, and molybdenum are often added to steel to increase the elasticity and fatigue limit of the spring and make it impact resistant. The materials of different springs are as follows:
1. Large springs are often processed by hot work, that is, the spring material is rolled into rods at high temperature, and after high temperature processing and forming, it is quenched in oil or water at about 780 degrees to 850 degrees, and then tempered at a temperature of 400 degrees to 500 degrees.
2. Small springs are annealed, then cold worked, rolled and then hardened and tempered, such as steel wire, piano wire or steel strip.
3. The strings are made of high carbon steel (0.65 ~ 0.95%), with less impurities, and the diameter is often less than 1/4 inch. They are drawn into strings at room temperature after being treated with halogenation. Their mechanical properties are good tensile strength and rigidity. It is an excellent coil spring material.
4. The stainless steel wire is used as a place subject to corrosion, and high-speed steel and stainless steel can be used under high temperature.
5. The carbon content of the oil tempering wire should be 0.6 ~ 0.7%, which should contain manganese. 0.6 ~ 1.0% is often used for coil springs.
6. For leaf springs, 0.9 to 1.0% of ordinary steel is commonly used, and the chrome vanadium steel and silicon-manganese steel are used in comparison with the most popular ones.
Non-ferrous and non-ferrous alloy steels are also a large category of spring materials, mainly divided into the following categories:
1. The alloy cannot be hardened by heat treatment, it only needs to be rolled.
2. Copper alloys for springs include phosphor bronze, brass, etc. The elasticity is lower than that of steel, which is inferior to flame and corrosion. It is generally used in chemical machine springs and can be used as a spring for electrical measuring devices due to non-magnetic relationship.
3. Monel is an alloy of copper and nickel. It is used in the food industry and is represented by K.
4. Inconel (75% Ni, 15% Cr, 10% Fe) will not relax at high temperatures (within 700 ° F). It is used in the springs of boilers, turbines and jet engines.
In addition, rubber springs are mainly used to absorb vibration and shock motion, and there are many resin materials or spring materials.
Second, heat treatment process
Crystal annealing: After the spring coil is finished, it must be recrystallized and annealed to stabilize the spring geometry and reduce deformation during quenching. The recrystallization annealing temperature is 550 ~ 650 ° C, and it is air-cooled after holding for 1 ~ 1.5h. A small amount can be carried out in a salt bath furnace, and a large number of continuous resistance furnaces are used to control the atmosphere.
Quenching: When quenching and heating in a salt bath furnace, the spring should be evenly aligned and tied with iron wire, or the spring should be placed on a core rod to heat it. When heating, ensure that the surface of the spring is oxidized and decarburized. The salt bath should be carefully deoxidized. It can also be heated in a box furnace with a controlled atmosphere. The heating temperature is 850 ° C ± 10 ° C, and the temperature is maintained for 10 to 15 minutes.
Corrective tempering should be carried out first. Generally, the tempering tempering temperature should be lower than the final tempering temperature of about 20 ° C, holding for 10-15 minutes, and air cooling. Then perform final tempering. After the spring size is corrected, install the spring on the tempering fixture to perform final tempering. The tempering and shaping fixture should ensure that the pitch and free length of the spring meet the requirements. Tempering temperature is 420 ° C ± 10 ° C, heat preservation is 30 ~ 35min, and water cooling is performed.
The diameter of the projectile is 0.3 ~ 0.5mm. When compressed air injection is used, the compressed air pressure is 0.4 ~ 0.5MPa; the shot velocity is 70m / s with a centrifuge. The return of the blasted spring can be more than doubled.