1. reasons for improvement
The hydraulic circuit of the gantry of a 14T forklift is controlled by four reversing valves, of which two reversing valves control the action of the gantry, one reversing valve controls the lifting action of the gantry, and one reversing valve controls the tilting action of the gantry. The 2-piece reversing valve controlling the action of the gantry accessories is often used for the fork side movement and distance adjustment. When the forklift gantry needs to be equipped with complex accessories (such as adding another accessory cylinder), the 2-piece reversing valve can not meet the requirements of working conditions. If the reversing valve with more pieces is used, not only the production cost will be increased, but also the existing design will need to be greatly modified. The improved front door frame hydraulic circuit is shown in Figure 1.
2. improvement method
In order to solve the problem that the existing 4-piece reversing valve can not meet the mounting of complex accessories, after research, we decided to improve the hydraulic circuit of the gantry, that is, add a 2-position 6-way solenoid valve 3 on the pipeline of the 4-piece reversing valve of the existing reversing valve group 1 to increase the action demand of 1 accessory cylinder 5. The improved hydraulic circuit of the rear door frame is shown in Figure 2. Lines (2, 4) in Figure 2 are used to connect two position six way solenoid valve 3 and accessory cylinder 5.
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Figure 2 improve the hydraulic circuit of the rear door frame 1 Reversing valve group 2, 4, 8 Line 3 Two position six way solenoid valve 5 Accessory cylinder 6 and 7 Sideshift cylinder
3. improved working process
Operate the spool of the 4th reversing valve on the left side to input pressure oil into the two position six way solenoid valve through line 2. The pressure oil enters the pipeline 8 through the oil ports of the two position six way solenoid valves C3 and C4, and then enters the sideshift cylinders (6 and 7) to push the sideshift cylinders (6 and 7) to realize the sideshift of the fork. If the pipeline connection mode of the sideshift cylinder (6, 7) is changed, other accessory actions can be realized.
Press the two position six way solenoid valve control switch, and the solenoid valve spool will move to the left position. At this time, operate the valve core of the left (4th piece) reversing valve, and the pressure oil enters the pipeline 4 through the oil ports of the two position six way solenoid valves C1 and C2, and then enters the accessory cylinder 5 to push the action of the accessory cylinder 5, so as to realize the actions (such as clamping, rotating, pushing out, etc.) required for the gantry to hang complex accessories. Release the two position six way solenoid valve control switch, the solenoid valve spool will move to the right position, and the action of side shift cylinder (6, 7) can be completed.
4. improvement effect
By adding two position six way solenoid valve and corresponding pipeline to the improved hydraulic circuit of gantry, a set of action circuit belonging to cylinder is added without adding reversing valve disc. The improved hydraulic circuit of gantry has good performance, easy installation, reliable use, simple maintenance and low cost. At present, it has been applied to 14T forklift in batches, and the user feedback is good.
