Jack refers to a light lifting device that uses a steel lifting member as a working device to lift heavy objects in the stroke through the top bracket or the bottom bracket. It is mainly used for vehicle repair and other lifting and support. This article mainly introduces the classification, usage instructions and safe operation specifications of the jack.
Classification of jacks
The jack is divided into two types: mechanical jacks and hydraulic jacks(Inflatable jacks and electric jacks are not the focus of this article). In principle, the hydraulic jack is based on the Pascal principle, that is, the pressure throughout the liquid is consistent. Therefore, in a balanced system, the pressure exerted on the relatively small piston is relatively small, and the pressure exerted on the large piston is relatively large, so that the liquid can be kept stationary. Therefore, through the transfer of liquid, different pressures on different ends can be obtained to achieve the purpose of transformation. Common hydraulic jacks use this principle to achieve force transmission.
The mechanical jack adopts the mechanical principle to reciprocate the handle, and the claw pulls the ratchet gap to rotate. The small bevel gear drives the large bevel gear to rotate the lifting screw, so that the lifting sleeve can be lifted or lowered to achieve the lifting force. Features.
Hydraulic jacks are divided into vertical and horizontal
Advantages: Lightweight and cheap.
Disadvantages: 1. Because there is no steel plate structure, the safety is relatively low.
2, the lifting speed is slow, the height is not enough (TORIN products can solve this problem perfectly, here to import the Torin Amazon link).
3. The oil pump may cause oil leakage.
4. Because the body is relatively small, it is easy to sink when used on soft roads.
Mechanical jacks, also known as scissor jacks, have the advantage of being lightweight and cheap .
Disadvantages: 1, the use is relatively tired.
2, there is no round top plate, the tire is easy to slide out.
3, if you are not using high-quality steel, plus the body is small, so it is easy to damage.
4. If the top lifting position is not appropriate, it will easily slide out, causing the heavy object to suddenly fall.
Jack use instructions
When the vehicle is jacked up, the engine must never be started, because the vibration of the engine or the rotation of the wheel will cause the vehicle to slip from the jack and cause danger. All models will have a fixed position for jacking. The jack must not be supported on the bumper, beam and other parts of the vehicle.
Maintenance personnel cannot work under unsupported vehicles. When changing the wheel, there can be no one in the car. Because the movement that people can produce can cause the vehicle to slip off the jack.
The operation of the jack:
1. It is necessary to check whether the parts are normal before use.
2. When using, the provisions of the main parameters should be strictly observed. Avoid excessive overload. Otherwise, when the lifting height or lifting tonnage exceeds the specified level, serious oil leakage will occur at the top of the cylinder.
3. If the oil quantity of the manual pump body is insufficient, it is necessary to add the N33# hydraulic oil which should be fully filtered to work in the pump.
4. For electric pumps, please refer to the instruction manual of the electric pump.
5, the center of gravity should choose moderate, reasonable choice of the focus of the jack, the bottom should be flat, while taking into account the soft and hard conditions of the ground, whether to pad the tough wood? Is the placement smooth? So as not to sink or tilt the load.
6. After the jack lifts the heavy object, the support should be used to support the heavy object in time. It is forbidden to use the jack as a support. Choose from TORIN’s 12-, 6-, 3-, and 2-ton heavy-duty security brackets. (Import Torin Amazon link)
7. If several jacks are required to work at the same time, in addition to the correct placement of the jacks, multi-top diverter valves should be used, and the load of each jack should be balanced. Pay attention to keep the lifting speed synchronized. It is also necessary to consider the possibility that the ground may be sunken due to uneven weight, and it is dangerous to prevent the weight from being tilted.
8. When using, first connect the quick connector of the manual pump to the top, then select the position and screw the oil drain screw on the oil pump to work. To lower the piston rod, the manual oil pump hand wheel is slightly loosened in the counterclockwise direction, the cylinder is unloaded, and the piston rod is gradually lowered. Otherwise, falling too fast will be dangerous.
9. Separate jack is a spring-returning structure. After lifting, it can be quickly taken out. It is not possible to use the connected hose to pull the jack.
10. Because the lifting stroke of the jack is small, do not exceed the rated stroke when using, so as not to damage the jack.
11. The jack should be violently vibrated during use.
12. It is not suitable for use in workplaces with acid and alkali and corrosive gases.
13. Regular inspection and maintenance.
Top 10 safety practices for jacks
1. Before use, check that all parts are in good condition and the oil is clean. It is strictly forbidden to use when the hydraulic jack safety bolt is damaged or the thread of the mechanical jack is worn by 20%.
2, the jack should be set in a flat, solid place, and padded with a mat.
3. The jack must be perpendicular to the load surface, and an anti-slip layer should be added between the top and the contact surface of the heavy object.
4. It is strictly forbidden to use overloaded jacks. It is not allowed to lengthen the handles and must not exceed the specified number of people.
5. When using, no one should stand in front of the safety bolt.
6. In the process of jacking up, the insurance cushion should be added under the weight with the rise of the heavy object. After reaching the top elevation, the weight should be padded in time.
7. When two or more jacks are used to lift an object at the same time, the total lifting capacity of the jack should be no less than twice the load. When jacking up, it should be unified and commanded by a special person to ensure that the jacking speed and force of each jack are basically the same.
8. The top elevation of the hydraulic jack shall not exceed the limit mark line; the top lift of the mechanical jack shall not exceed 3/4 of the height of the screw or rack.
9. Jacks shall not bear the load under unattended care for a long time.
10. The speed of the jack must be slow. It is strictly forbidden to drop suddenly under load.