type
Forklifts can be divided into two types according to the position of the gantry. The front of the gantry is called the front forklift (Figure 1), and the side of the gantry is called the side forklift (Figure 2). ① Front wooden forklift: The cab is arranged in the middle of the frame, and the engine is installed at the back for balance. A lifting gantry is installed at the front end of the frame. The lifting gantry is pushed by an oil cylinder and can tilt back and forth, which is convenient for shoveling or unloading wood. When working, the wood can cling to the gantry and is not easy to slide out. A lifting fork is hung in front of the gantry, and a claw is installed on it to clamp the loaded wood. The chassis structure of forklift truck is similar to that of automobile, which is transmitted from engine to gearbox through hydraulic torque converter, changing the driving speed and direction. Because the gantry is close to the front wheel, in order to obtain better wheel driving torque, front wheel driving and rear wheel steering are usually adopted. For easy driving, a hydraulic booster is usually equipped. ② Side wood forklift: The cab, engine and gantry support device are arranged on one side of the platform frame. There is an open slot in the middle of the platform, and rails are laid on both sides of the slot. The gantry is pulled by the oil cylinder through the chain and can move back and forth along the groove rail. When the gantry reaches the outside of the car body, put down the feet of the hydraulic jack to help support the frame and shovel the wood with a fork. After the wood is full, the lifting cylinder is operated to jack up the inner portal frame, and at the same time, the fork frame is lifted along the inner portal frame through two groups of sprockets and chains, and then the transverse cylinder is operated to retract the portal frame and put the wood on the platform. Take back your feet and you can drive. The walking system of a side forklift is similar to that of a car, except that the engine is offset on one side of the car body. The power from the engine is transmitted to the double universal joint under the frame through the clutch or hydraulic torque converter, gearbox and chain transmission box, and then the wheel is rotated through the drive axle, half shaft and wheel side reducer. The side forklift truck is driven by rear wheels, and the front wheels turn. The steering system is equipped with hydraulic booster or full hydraulic double cylinder or power steering.
Figure 1
Figure 2 Performance
The main performance of forklift truck is the rated lifting weight, that is, the allowable load when loading in the standard load center. In forestry, the rated lifting weight of wood forklift trucks is generally 3 tons and 5 tons, and the lifting height is 3 ~ 4 meters; The portal frame has a rake angle of 5 ~ 10, and the rake angle is the same or slightly larger. The maximum rake angle can reach 20, and the turning radius outside the wheel is 3 ~ 5 meters. The driving speed can reach more than 20 ~ 30 km/h; Climbing ability is about 20. In the product model, the character CZ represents the front forklift, CC represents the side forklift, and then the number represents the rated lifting capacity (tons). For example, CC5 indicates that the rated lifting capacity of the side forklift is 5 tons.
development trends
In the 1980s, people generally paid attention to the versatility of forklift trucks. For example, as a working accessory, the fork can be changed into a long cantilever hanger to strengthen the extra-long original strip or long building wood. Another example is that the gantry mechanism is made into a front-side integrated structure that can rotate 90 degrees, which has the advantages of both front-side forklifts and side forklifts, and has good maneuverability, and is suitable for transporting outstanding talents in workshops, warehouses or along narrow passages. A four-point suspension system consisting of a spring, a rubber block and a buffer cylinder is adopted between the frame and the support shaft of a side forklift with a lifting weight of less than 10 ton, and the hydraulic jack-type leg is eliminated, so that the stability of the forklift can still be maintained. At this time, it is necessary to adopt the composite frame of box section steel and torsion tube girder structure to bear the serious stress caused by the lack of legs. Considering the working comfort, the cab adopts vibration damping rubber suspension facilities and sound insulation wallboard, establishes a safety protection steel frame, and adopts large glass around it to expand the working vision. In order to achieve the best economic benefits of loading and unloading operations, large-tonnage forklifts, such as 20 tons to 50 tons, are being developed.