The mast or fork frame of a reach truck can move forward and backward. When moving forward, the cargo carried on the fork is in a cantilever state relative to the front wheel. Electric forklift manufacturers manufacture reach forklifts, which have two types: mast forward and fork forward. The forward moving type of the mast means that the former mast drives the fork to move forward during operation, and stretches out of the front wheel to pick up or put down the goods; when walking, the fork retracts with the goods, so that the center of gravity of the goods is in the support surface.

reach truck

The forward-moving type of the fork frame means that the fork frame drives the fork to move forward to work outside the front wheel; when walking, the fork frame brings the fork and the goods retract into the support surface, and the opposite is true when placing the goods.

Reach trucks are mainly composed of battery packs, car bodies, follower support wheels, driving wheels, bogies, drive motors, steering systems, hydraulic joysticks, hydraulic pumps and motors, front wheels, etc.; structurally can be divided into There are four parts: the forward moving mechanism, the driving device, the steering device and the braking device.

reach truck

1.Forward mechanism. The forward moving mechanism of the reach forklift mainly includes two parts: the mast forward moving mechanism and the fork frame forward moving mechanism.

The front mechanism of the mast has a forward wheel frame at the lower part of the mast, on which two pairs of vertical guide rollers and two pairs of horizontal guide rollers are arranged on both sides of the forward wheel frame; Rolls on outrigger tracks. One end of the front pipetting cylinder is connected to the middle and lower part of the door frame, and the other end is connected to the car body, so that the door frame can be pushed and pulled to move forward or retract.

The rear frame of the forward-moving stacker can be lifted and lowered in the mast, the fork is hung on the front frame, and the front frame and the rear frame are connected by a scissor linkage mechanism. When the hydraulic cylinder is pushed out, the connecting rod of the scissors is opened, and the front frame together with the fork is extended out of the car body to complete the forward movement. Conversely, the backward movement is completed when the hydraulic cylinder is retracted.

In order to enable the forks of the reach-type forklift to reach two rows of goods for stacking and dismantling operations, the combination of the forward-moving mast and the forward-moving fork can be used, or the forward-moving of the two-stage fork-type linkage mechanism can be used. Fork frame to increase the forward distance of the fork.

2. Drive device. The driving device of the reach truck is mainly composed of a driving motor and a driving wheel. The driving motor is vertically arranged, and the output end of the motor adjusts the speed of the car to the set value through a pair of inclined wheels and a pair of circular spiral bevel gears. The drive wheels are also steerable wheels and use solid tires.

Matched with the drive wheels is a set of small-diameter follower support wheels, which are also solid tires. In order to ensure good follow-up performance, electric forklift manufacturers usually maintain an eccentricity of 50mm~150mm between the axis of the follower wheel bracket bearing and the axis of the follower wheel. When the driving wheel or follower wheel encounters uneven ground, the rigid bogie can swing around its axis of rotation to keep both the drive wheel and follower wheel in contact with the ground. Since the ground on which the reach truck operates is relatively flat, the swing angle generally does not exceed 3. There is also a kind of elastic bogie, the follower wheel bracket is connected to the bogie through a spring, so that the follower wheel can float up and down, and the floating stroke is general. No more than 8mm.

reach truck

3. Steering device. The steering device of reach truck can be divided into power steering and mechanical steering. Among them, power steering can be divided into hydraulic servo steering and electrical servo steering. The mechanical steering device is mainly composed of steering wheel, steering chain, rigid bogie, steering column and so on.

With the telescopic universal joint structure, the steering wheel can still operate normally when the steering device fixed on the bogie swings up and down with the rigid bogie.

For a reach truck using an electric servo steering system, the input shaft and the output shaft are connected by an elastic device with a rotation angle sensor, and the output torque of the steering motor is transmitted to the output shaft through a gear pair. During power steering, the rotation angle deviation between the input shaft and the output shaft generated by the rotation angle sensor is eliminated by controlling the rotation of the steering motor. The device can also be turned manually, and the steering wheel is driven by manpower to rotate the wheelset. Compared with the hydraulic servo steering system, the electric servo steering system has a simpler structure, can save 70% to 80% of steering energy consumption, and has a small operating force during manual steering, so it is widely used.

4. Braking system. The brake system of the reach forklift is composed of two parts: service brake and parking brake. The brake device is mainly composed of brake master cylinder, brake pedal, hand brake lever, brake oil box, brake plate, It consists of sub-cylinders, motor disc brake pads, front wheel brakes and other devices. When braking, the brake pedal pushes the brake master cylinder and divides the fluid into two paths: one path is sent to the sub-cylinders of the two front wheel brakes to brake the front wheels by expanding the brakes; the other path is sent to Go to the brake sub-cylinder on the upper end of the drive motor to push the disc brake pads to brake the motor. When parking and braking, the brake hand pulls the steel wire to drive the brake pressure plate to press down the disc brake pad to brake the motor.

Usually, the structure of the service braking part is simplified, which can also meet the braking performance requirements of the reach truck. For example, the electric forklift manufacturer cancels the hydraulic braking part, does not take braking measures for the front wheels, but only brakes the drive motor. The motor shaft end brakes used are disc brakes, shoe brakes or band brakes. In addition, reverse connection or regenerative electric braking can also be assisted by the electric controller of the vehicle.