Correct Use of Jack


A car will be equipped with a lot of commonly used on-b […]

A car will be equipped with a lot of commonly used on-board tools, of which the jack is a relatively important tool. Today, we will explain the use of several common jacks for household cars.
The function of jack:
Generally speaking, jacks are used when changing tires and preliminarily checking the chassis of a vehicle.
Kinds of jacks:
It can be divided into rack jack, screw (mechanical) jack, hydraulic (hydraulic) Jack and pneumatic jack.
Usage method:
Rack jack is the most common form of Jack in household cars. Rack jack is driven by human through lever and gear to lift weights. There are two kinds of jacks, one is herringbone, the other is rhombus.
Advantages: light weight, small folded volume, good storage. Disadvantage: The support is not very strong, the weight of the support is limited, generally only used for household cars in the first ton.
The screw jack relies on the self-locking action of threads to support heavy objects. Advantages: The Jack has simple structure, reliable life and large load-bearing capacity. Disadvantage: But the weight of this kind of Jack is generally heavy, and the transmission efficiency is relatively low, and the lift is slow.
Some spiral jacks are rotated directly with original wrenches.
Hydraulic Jack uses oil pressure to lift the jack, which is time-saving and labor-saving. The principle is to manually press the oil in the oil storage chamber into the cylinder through a one-way valve to lift weights. Advantages: The speed of lifting and descending is very fast, and the maximum load-bearing capacity is generally large, about 3 tons. It can be seen in most garages. Disadvantage: But the size of this kind of Jack is much larger than the above two kinds of jacks, which is inconvenient to carry, so it will not appear in the toolbox of household cars basically, and can only be purchased independently if necessary.
The inflatable jack is to inflate the air bag by using the exhaust gas of the vehicle. Generally, the maximum support weight of this kind of Jack is about 4 tons. It is suitable for rescue or self-rescue and extrication of off-road vehicles under more difficult conditions. Domestic auto parts malls are sold, and it is usually inflated by the exhaust gas of the vehicle to achieve the purpose of support.
Matters needing attention
Fixed the car completely before lifting it
This is very important. If the vehicle is not completely fixed before the branch, it is likely that the sliding of the vehicle will cause the sliding phenomenon in the support process. I have witnessed the vehicle falling off the jack. The good result is that the tool is broken, and the bad result is that the vehicle or even the personnel are damaged.
Soft pavement should be used with cushion board
Jack must be used on hard and smooth pavement. If it is on soft ground, such as mud road or sand road, it is recommended to use wooden or stone pad under the jack before using the jack to reduce the pressure so as to prevent the jack from falling into the soft ground.
Be sure to support on the chassis
When using the jack, we should pay attention to the special support point of the body chassis. The support point of the family car is usually inside the side skirt, like the two fins on both sides of the chassis, about 20 centimeters behind the front of the front wheel and about 20 centimeters in front of the rear wheel. This fin is protruding from the chassis steel plate and can withstand relatively high pressure. If the jack is supported on the steel plate of the chassis in the wrong way, it will probably cause unnecessary damage to the chassis. In addition, it is also incorrect to support on the suspended pendulum arm. If the jack slips and the vehicle falls down, the chassis and the jack will be damaged.