A hydraulic system for lift truck fork spread and side shift

Abstract

This utility model belongs to the field of forklift technology, specifically disclosing a hydraulic system for fork offset adjustment and lateral movement. It includes a multi-way directional valve connected to the oil pump outlet, comprising a first valve, a second valve, and a third valve connected in parallel. Ports A1 and B1 of the first valve are connected to the rodless and rod-side chambers of the left offset cylinder, respectively. Ports A2 and B2 of the second valve are connected to the rodless chambers of the left and right offset cylinders, respectively. Ports A3 and B3 of the third valve are connected to the rod-side and rodless chambers of the right offset cylinder, respectively. By operating the first and third valves, the right and left forks move horizontally respectively, achieving fork offset adjustment. By operating the second valve, the right and left forks move horizontally simultaneously, achieving fork lateral movement. This application achieves independent left and right movement of the left and right forks using two offset cylinders, and also allows the left and right forks to move simultaneously in the same direction, realizing fork offset adjustment and lateral movement functions.

Description

Technical Field

[0001] This utility model relates to the field of forklift technology, and in particular to a hydraulic system for adjusting fork spacing and lateral movement. Background Technology

[0002] Forklifts are industrial handling vehicles that use attachments such as forks to load, unload, stack, and transport goods over short distances. They are now widely used in warehouses, docks, and other similar locations.

[0003] Because different goods or pallets have different dimensions, the distance between the forks needs to be adjusted according to the size of the goods or pallets to ensure even weight distribution, stable handling, and prevent uneven loading or slippage. For forklifts with larger tonnage, the forks are also very heavy, making manual adjustment difficult. Therefore, most forklifts use a hydraulic system with dedicated pitch cylinders for adjustment. These cylinders move the forks laterally to adjust the distance between them. This method requires two pitch cylinders for individual fork adjustment, and an additional lateral movement cylinder for lateral movement of the goods. This results in a complex hydraulic system, obstructs the driver's view, and poses safety hazards during handling. Utility Model Content

[0004] Based on the above-mentioned technical problems, this utility model proposes a hydraulic system for adjusting fork spacing and lateral movement, which solves the problem of adjusting fork spacing and lateral movement of goods on large-tonnage forklifts.

[0005] The specific technical solution of this utility model is as follows: A hydraulic system for fork offset adjustment and lateral movement includes a multi-way directional valve connected to the outlet of an oil supply pump. The multi-way directional valve includes a first valve, a second valve, and a third valve connected in parallel. Ports A1 and B1 of the first valve are connected to the rodless and rod-side chambers of the left offset cylinder, respectively. Ports A2 and B2 of the second valve are connected to the rodless chambers of the left and right offset cylinders, respectively. Ports A3 and B3 of the third valve are connected to the rod-side and rodless chambers of the right offset cylinder, respectively. Fork offset adjustment is achieved by operating the first and third valves to move the right and left forks horizontally, respectively. Lateral movement of the forks is achieved by operating the second valve to move the right and left forks horizontally simultaneously.

[0006] In a further embodiment, a safety valve is also connected between the inlet and return ports of the multi-way directional valve.

[0007] In a further embodiment, the first, second, and third valves are all three-position four-way directional valves.

[0008] In a further embodiment, the oil port A1 of the first valve and the oil port A2 of the second valve are both connected to the rodless chamber of the left adjusting cylinder through a first tee connector. The oil port B1 of the first valve plate is connected to the rod chamber of the left adjusting cylinder through the second three-way connector; the oil port A3 of the third valve plate is connected to the rod chamber of the right adjusting cylinder through the third three-way connector; the second three-way connector and the third three-way connector are connected. The oil port B2 of the second valve and the oil port B3 of the third valve are both connected to the rodless chamber of the right adjusting cylinder through the fourth three-way connector.

[0009] In a further embodiment, the piston end of the left adjusting cylinder is connected to the right fork to drive the right fork to move horizontally; the piston end of the right adjusting cylinder is connected to the left fork to drive the left fork to move horizontally.

[0010] In a further embodiment, the oil inlet of the oil supply pump is connected to the hydraulic oil tank, and the return port T of the multi-way directional valve is connected to the hydraulic oil tank.

[0011] This application achieves independent left and right movement of the left and right forks using two adjustable hydraulic cylinders, and also allows the left and right forks to move simultaneously in the same direction, enabling the forks to perform multiple different actions and expanding the application range of the forklift. Furthermore, this application features a simple structure with fewer hydraulic cylinders and other components, avoiding the high costs and poor visibility issues associated with complex structures, thus solving a major pain point in the forklift industry.

[0012] The hydraulic system of this application achieves the fork adjustment and lateral movement functions simply by connecting the hydraulic system pipelines, without adding oil cylinders or other structures, through high-pressure rubber hoses and T-joints. Its structure is simple and low-cost. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the hydraulic system of this utility model; In the diagram: 1. Oil supply pump; 2. Safety valve; 3. Multi-way directional valve; 4. First tee valve; 5. Second tee valve; 6. Left adjusting cylinder; 7. Right adjusting cylinder; 8. Third tee valve; 9. Fourth tee valve; 10. Second tee valve; 11. Third tee valve; 12. Hydraulic oil tank; 13. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0015] refer to Figure 1 This embodiment provides a hydraulic system for adjusting fork spacing and lateral movement, including an oil supply pump 1. The oil inlet of the oil supply pump 1 is connected to a hydraulic oil tank 13. The oil outlet of the oil supply pump 1 is connected to a multi-way directional valve 3. The multi-way directional valve 3 has an oil inlet P and an oil return port T. The oil return port T is connected to the hydraulic oil tank 13.

[0016] The multi-way directional valve 3 includes a first valve 4, a second valve 11, and a third valve 12 connected in parallel. The oil ports A1 and B1 of the first valve 4 are connected to the rodless chamber and rod chamber of the left adjusting cylinder 7, respectively. The oil ports A2 and B2 of the second valve 11 are connected to the rodless chamber of the left adjusting cylinder 7 and the right adjusting cylinder 8, respectively. The oil ports A3 and B3 of the third valve 12 are connected to the rod chamber and rodless chamber of the right adjusting cylinder 8, respectively. By operating the first valve 4 and the third valve 12, the right and left forks are moved horizontally respectively, thereby achieving fork offset adjustment. By operating the second valve 11, the right and left forks are moved horizontally simultaneously, thereby achieving fork lateral movement.

[0017] In this embodiment, the first valve 4, the second valve 11, and the third valve 12 are all three-position four-way directional valves, which are a type of solenoid valve. Specifically, an O-type three-position four-way directional valve with a neutral position function can be selected. Each valve has four ports: an inlet port, a return port, and two working ports. When the valve is not in operation, it is in the neutral position, and all four ports are closed, realizing the parallel connection of multiple three-position four-way directional valves. The hydraulic oil returns directly from the return port T of the multi-way directional valve 3 to the hydraulic oil tank 13. Specifically, the oil port A1 of the first valve 4 and the oil port A2 of the second valve 11 are both connected to the rodless chamber of the left adjusting cylinder 7 through the first three-way connector 5. The oil port B1 of the first plate valve 4 is connected to the rod chamber of the left adjusting cylinder 7 through the second three-way connector 6; the oil port A3 of the third plate valve 12 is connected to the rod chamber of the right adjusting cylinder 8 through the third three-way connector 9; the second three-way connector 6 and the third three-way connector 9 are connected. The oil port B2 of the second valve 11 and the oil port B3 of the third valve 12 are both connected to the rodless chamber of the right adjusting cylinder 8 through the fourth three-way connector 10.

[0018] That is, when each disc valve is working, one working oil port is connected to the oil inlet, and the other working oil port is connected to the oil return port, forming an oil circulation.

[0019] In this embodiment, the cylinder seats of the left adjusting cylinder 7 and the right adjusting cylinder 8 are both horizontally fixed on the fork carriage, and the left and right forks are slidably mounted on the fork carriage. The piston end of the left adjusting cylinder 7 is connected to the right fork to drive the right fork to move horizontally; the piston end of the right adjusting cylinder 8 is connected to the left fork to drive the left fork to move horizontally.

[0020] To prevent excessive system pressure and protect the system and equipment from overpressure damage, a safety valve 2 is connected between the inlet and return ports of the multi-way directional valve 3. That is, when the first valve 4, the second valve 11, and the third valve 12 are not working, the hydraulic oil discharged from the oil supply pump 1 directly flows through the inlet P of the multi-way directional valve 3, the safety valve 2, and the return port T of the multi-way directional valve 3, and finally returns to the hydraulic oil tank 13.

[0021] In the initial state of the forklift, the oil supply pump 1 converts the hydraulic oil in the hydraulic oil tank 13 into hydraulic oil with a certain pressure and outputs it. The hydraulic oil enters the multi-way directional valve 3 through the oil inlet P. At this time, the first valve 4, the second valve 11, and the third valve 12 are all in the neutral position. The hydraulic oil flows through the neutral oil passage of the multi-way directional valve 3 and then flows back to the hydraulic oil tank 13 through the oil return port T.

[0022] Fork spacing adjustment: When the first valve 4 is operated, the hydraulic oil flows through the inlet P of the multi-way directional valve 3 to the port A1 of the first valve 4, and then enters the rodless chamber of the left adjusting cylinder 7 through the first three-way connector 5. At this time, the piston rod of the left adjusting cylinder 7 extends and pushes the right fork to move to the right. At the same time, the hydraulic oil in the rod chamber of the left adjusting cylinder 7 enters the return port T of the multi-way directional valve 3 through the second three-way connector 6, the port B1 of the first valve 4, and the return end, and finally returns to the hydraulic oil tank 13. Similarly, when the first valve 4 is operated in the opposite direction, the hydraulic oil flows through the inlet P of the multi-way directional valve 3 to the port B1 of the first valve 4, and then enters the rod chamber of the left adjusting cylinder 7 through the second three-way connector 6. At this time, the piston rod of the left adjusting cylinder 7 retracts and pushes the right fork to move to the left; at the same time, the hydraulic oil in the rodless chamber of the left adjusting cylinder 7 returns to the hydraulic oil tank 13 through the port A1 of the first valve 4, the return end, and the return port T of the multi-way directional valve 3. When the third valve 12 is operated, the hydraulic oil flows through the inlet P of the multi-way directional valve 3 to the port B3 of the third valve 12, and then enters the rodless chamber of the right adjusting cylinder 8 through the fourth three-way connector 10. At this time, the piston rod of the right adjusting cylinder 8 extends and pushes the left fork to move to the left. At the same time, the hydraulic oil in the rod chamber of the right adjusting cylinder 8 returns to the hydraulic oil tank 13 through the port A3 of the third valve 12, the return end, and the return port T of the multi-way directional valve 3. Similarly, when the third valve 12 is operated in the opposite direction, the hydraulic oil flows through the inlet P of the multi-way directional valve 3 to the port A3 of the third valve 12, and enters the rod chamber of the right adjusting cylinder 8. At this time, the piston rod of the right adjusting cylinder 8 retracts and pushes the left fork to move to the right. At the same time, the hydraulic oil in the rodless chamber of the right adjusting cylinder 8 returns to the hydraulic oil tank 13 through the port B3 of the third valve 12 and the return port T of the multi-way directional valve 3.

[0023] By operating the first valve 4 and the third valve 12, the right and left forks can be moved arbitrarily in the left and right directions, thereby realizing the fork spacing adjustment function.

[0024] Fork side shift: When the second valve 11 is operated, hydraulic oil flows through the inlet P of the multi-way directional valve 3 to the port A2 of the second valve 11, and then through the first three-way connector 5 into the rodless chamber of the left adjusting cylinder 7. At this time, the piston rod of the left adjusting cylinder 7 extends and pushes the right fork to move to the right. Simultaneously, the hydraulic oil in the rod chamber of the left adjusting cylinder 7 flows through the second three-way connector 6 and the third three-way connector 9 to the rod chamber of the right adjusting cylinder 8. The piston rod of the right adjusting cylinder 8 retracts and pushes the left fork to move to the right. At this time, the hydraulic oil in the rodless chamber of the right adjusting cylinder 8 flows through the fourth three-way connector 10, the port B2 of the second valve 11, and then through the return port T of the multi-way directional valve 3 back to the hydraulic oil tank 13. At this time, the right and left forks move to the right simultaneously, realizing the overall rightward movement of the goods.

[0025] Similarly, when the second valve 11 is operated in the opposite direction, hydraulic oil flows through the inlet P of the multi-way directional valve 3 to the port B2 of the second valve 11, and then through the fourth three-way connector 10 into the rodless chamber of the right adjusting cylinder 8. At this time, the piston rod of the right adjusting cylinder 8 extends and pushes the left fork to move to the left. Simultaneously, the hydraulic oil in the rod chamber of the right adjusting cylinder 8 flows through the third three-way connector 9 and the second three-way connector 6 to the rod chamber of the left adjusting cylinder 7. The piston rod of the left adjusting cylinder 7 retracts and pushes the right fork to move to the left. At the same time, the hydraulic oil in the rodless chamber of the left adjusting cylinder 7 flows through the first three-way connector 5 and the port A2 of the second valve 11, and then through the return port T of the multi-way directional valve 3 back to the hydraulic oil tank 13. At this time, the right and left forks move to the left simultaneously, realizing the overall leftward movement of the goods.

[0026] By operating the second valve 11, the right fork and the left fork can move to the right or to the left simultaneously, thereby realizing the fork lateral movement function.

[0027] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0028] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A hydraulic system for adjusting fork spacing and lateral movement, comprising a multi-way directional valve (3) connected to the outlet of an oil supply pump (1), characterized in that: The multi-way directional valve (3) includes a first valve (4), a second valve (11), and a third valve (12) connected in parallel. The oil ports A1 and B1 of the first valve (4) are connected to the rodless chamber and the rod chamber of the left adjusting cylinder (7), respectively. The oil ports A2 and B2 of the second valve (11) are connected to the rodless chamber of the left adjusting cylinder (7) and the right adjusting cylinder (8), respectively. The oil ports A3 and B3 of the third valve (12) are connected to the rod chamber and the rodless chamber of the right adjusting cylinder (8), respectively. By operating the first valve (4) and the third valve (12), the right and left forks are moved horizontally, thereby achieving fork offset adjustment. By operating the second valve (11), the right and left forks are moved horizontally simultaneously, thereby achieving fork lateral movement.

2. The hydraulic system of claim 1, wherein: A safety valve (2) is also connected between the inlet and return ports of the multi-way directional valve (3).

3. The hydraulic system of claim 1, wherein: The first valve (4), the second valve (11), and the third valve (12) are all three-position four-way directional valves.

4. The hydraulic system according to claim 1, characterized in that: The oil port A1 of the first valve (4) and the oil port A2 of the second valve (11) are both connected to the rodless chamber of the left adjusting cylinder (7) through the first three-way connector (5); The oil port B1 of the first plate valve (4) is connected to the rod chamber of the left adjusting cylinder (7) through the second three-way connector (6); the oil port A3 of the third plate valve (12) is connected to the rod chamber of the right adjusting cylinder (8) through the third three-way connector (9); the second three-way connector (6) is connected to the third three-way connector (9); The oil port B2 of the second valve (11) and the oil port B3 of the third valve (12) are both connected to the rodless chamber of the right adjusting cylinder (8) through the fourth three-way connector (10).

5. The hydraulic system according to claim 1, characterized in that: The piston end of the left adjustable cylinder (7) is connected to the right fork to drive the right fork to move horizontally; the piston end of the right adjustable cylinder (8) is connected to the left fork to drive the left fork to move horizontally.

6. The hydraulic system according to claim 1, characterized in that: The oil inlet of the oil pump (1) is connected to the hydraulic oil tank (13), and the return port T of the multi-way directional valve (3) is connected to the hydraulic oil tank (13).

Images