Improvement of Hydraulic Circuit of Forklift Gantry

    The hydraulic circuit of a 14t class forklift door frame is controlled by 4 reversing valves, of which 2 reversing valves control the gantry attachment action, 1 reversing valve controls 1 gantry lifting movement, 1 reversing valve control 1 The gantry tilts. The two-way reversing valve that controls the gantry is often used for side shifting and shifting of forks. When the forklift gantry needs to be equipped with complex attachments (such as adding another attachment cylinder), the two reversing The valve can not meet the working conditions. If you switch to a more reversing valve, you will not only increase the production cost, but also make major changes to the existing design. Improve the front door hydraulic circuit as shown in Figure 1.

 2. Improved method

  In order to solve the problem that the existing four-piece reversing valve can not meet the complicated attachment of the hanging, we have decided to improve the hydraulic circuit of the gantry by adding one to the fourth reversing valve of the existing reversing valve group 1. Two-position six-way solenoid valve 3 to increase the movement requirement of one accessory cylinder 5. The improved rear door hydraulic circuit is shown in Figure 2. The lines (2, 4) in Fig. 2 are used to connect the two-position six-way solenoid valve 3 and the accessory cylinder 5.

Figure 2 Improved rear door hydraulic circuit 1. Reversing valve group 2, 4, 8. Pipeline 3. Two-position six-way solenoid valve 5. Attachment cylinder 6, 7. Side shift cylinder

  3. Improved working process

 

    Operate the 4th reversing valve spool on the left side, and press the pressure oil into the 2/2-way solenoid valve through line 2. The pressure oil enters the pipeline 8 through the two-position six-way solenoid valves C3 and C4, and then enters the side shift cylinders (6, 7) to push the side shift cylinders (6, 7) to operate, so as to realize the lateral shift of the fork. If you change the pipe connection mode of the side shift cylinder (6, 7), other attachment 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, the left (fourth) reversing valve spool is operated, and the pressure oil enters the pipeline 4 through the two-position six-way solenoid valves C1 and C2, and then enters the accessory cylinder 5 to push the accessory cylinder 5 to move. The gantry is equipped with complex operations (such as clamping, rotating, pushing, etc.). When the two-position six-way solenoid valve control switch is released, the solenoid valve spool will move to the right position, and the movement of the side shift cylinders (6, 7) can be completed.

 

    4. Improve the effect

 

    The improved gantry hydraulic circuit adds a set of action circuit of the accessory cylinder by adding a two-position six-way solenoid valve and corresponding pipelines without increasing the valve of the reversing valve. The improved gantry hydraulic circuit has good performance, convenient installation, reliable use, easy maintenance and low cost. It has been applied in batches on 14t class forklifts with good user feedback.