A steering priority and pilot valve set for a fork truck

Abstract

The application discloses a steering priority and pilot valve group for a fork loader, which comprises a valve block body, a first oil port connected to the valve block body, a first oil path and a second oil path connected in parallel at an outlet end of the first oil port, a dynamic priority valve arranged on the first oil path, an outlet of the dynamic priority valve connected to a third oil path and a fourth oil path arranged in parallel, the third oil path connected to an external steering valve, and the fourth oil path connected to an external action valve, a pressure reducing valve arranged on the second oil path, and a parking valve, a pilot valve and a high-low speed valve connected in parallel at an outlet of the pressure reducing valve. The application combines the functions of a steering control system and a pilot control system on the same valve block, reduces the number of components, lowers the cost, realizes the sharing of component resources, and has the characteristics of simple structure, low cost, good pressure maintaining capability and high system integration.

Description

Technical Field

[0001] This utility model relates to the technical field of hydraulic control equipment for engineering machinery, and in particular to a steering priority and pilot valve assembly for forklift trucks. Background Technology

[0002] Currently, in construction machinery forklifts, the hydraulic power steering, braking, high / low speed switching, and pilot control systems are all independently designed, with each control system equipped with a separate hydraulic pump. However, the accumulators in the hydraulic braking and pilot systems operate intermittently, resulting in low utilization rates of their associated hydraulic pumps and thus energy waste. Furthermore, multiple independent hydraulic systems require a large number of hydraulic components, which not only increases costs but also complicates system layout, cumbersome piping connections, and increases maintenance difficulty. Therefore, there is an urgent need for an integrated hydraulic valve assembly that can share component resources, simplify system structure, and improve energy utilization efficiency. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a steering priority and pilot valve assembly for forklifts, including a valve block body. A first oil port is connected to the valve block body, and the outlet end of the first oil port is connected to a first oil circuit and a second oil circuit arranged in parallel, wherein:

[0004] The first oil circuit is equipped with a dynamic priority valve. The outlet of the dynamic priority valve is connected to the third oil circuit and the fourth oil circuit, which are connected in parallel. The third oil circuit is connected to the external steering valve, and the fourth oil circuit is connected to the external actuation valve.

[0005] The second oil circuit is equipped with a pressure reducing valve, and the outlet of the pressure reducing valve is connected to a parking valve, a pilot valve and a high and low speed valve arranged in parallel.

[0006] In some embodiments, a first bypass is also included, the inlet of which is connected to the outlet of the dynamic priority valve, the outlet of which is connected to a second oil port provided on the valve block body, and a first relief valve is connected to the first bypass.

[0007] In some embodiments, the first bypass is connected to a first filter for filtering impurities.

[0008] In some embodiments, a second filter for filtration is connected to the second oil line, and the second filter is located between the first oil port and the pressure reducing valve.

[0009] In some embodiments, a check valve is also connected to the second oil line, and the check valve is located at the outlet end of the pressure reducing valve.

[0010] In some embodiments, a second bypass is also included, the inlet of which is connected to the outlet of the check valve, the outlet of which is connected to a second oil port provided on the valve block body, and a second relief valve is connected to the second bypass.

[0011] In some embodiments, the first oil circuit is connected to a first pressure testing port disposed on the valve block body, and a first pressure measuring instrument is connected to the first pressure testing port.

[0012] In some embodiments, the second oil circuit is connected to a second pressure test port disposed on the valve block body, and a second pressure gauge is connected to the second pressure test port.

[0013] In some embodiments, a fourth oil port is connected to the valve block body, and an accumulator is connected to the fourth oil port.

[0014] In some embodiments, the valve block body is further provided with a third oil port, and a service brake valve arranged in parallel with the parking valve is connected to the third oil port.

[0015] Compared with existing technologies, this application provides a steering priority and pilot valve assembly for forklifts. In this assembly, external hydraulic oil enters the valve block body through a first port, supplying oil to the first and second oil circuits. In the first oil circuit, a dynamic priority valve prioritizes supplying oil to the external steering valve during steering action, and then supplies oil to other external valves. In the second oil circuit, a pressure reducing valve lowers the pressure of the external hydraulic oil to the low pressure required by the pilot control system, and then supplies oil according to the actions of the parking valve, pilot valve, and high / low speed valves. This application combines the functions of the steering control system and the pilot control system on the same valve block, reducing the number of components, lowering costs, and achieving resource sharing. It features a simple structure, low cost, good pressure holding capacity, and high system integration. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the hydraulic principle of the steering priority and pilot valve group used in the embodiments of this application for forklifts.

[0017] In the diagram: 1. First oil port, 2. Dynamic priority valve, 3. Third oil circuit, 4. Fourth oil circuit, 5. Pressure reducing valve, 6. Parking valve, 7. Pilot valve, 8. High and low speed valve, 9. Second oil port, 10. First relief valve, 11. First filter, 12. Second filter, 13. Check valve, 14. Second relief valve, 15. First pressure test port, 16. Second pressure test port, 17. Accumulator. Detailed Implementation

[0018] To facilitate understanding of the structure and operation of this utility model, the following description, in conjunction with the accompanying drawings and optimized embodiments, provides a more comprehensive and detailed account of the utility model. However, the scope of protection of this utility model is not limited to the specific embodiments described below. It should be noted that, without affecting the effectiveness of use, the structural features and component dimensions, connection methods, and device sizes in the embodiments of this utility model can be changed.

[0019] Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The terms "first," "second," and similar terms used in this utility model patent application specification and claims do not indicate any order, quantity, or importance, but are merely for the purpose of distinguishing corresponding components. Similarly, the terms "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "connection" or "connected" are not limited to direct connections, but can refer to indirect connections through other intermediate connecting parts. Terms such as "above," "below," "one side," "the other side," "vertical," and "horizontal" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0020] like Figure 1 As shown, the present invention provides a steering priority and pilot valve assembly for a forklift, comprising a valve block body (not shown in the figure), wherein a first oil port 1 is connected to the valve block body, and the outlet end of the first oil port 1 is connected to a first oil circuit and a second oil circuit arranged in parallel, wherein:

[0021] The first oil circuit is equipped with a dynamic priority valve 2. The outlet of the dynamic priority valve 2 is connected to the third oil circuit 3 and the fourth oil circuit 4, which are arranged in parallel. The third oil circuit 3 is connected to the external steering valve, and the fourth oil circuit 4 is connected to the external actuation valve.

[0022] The second oil circuit is equipped with a pressure reducing valve 5, and the outlet of the pressure reducing valve 5 is connected to a parking valve 6, a pilot valve 7 and a high and low speed valve 8 arranged in parallel.

[0023] In the above embodiment, external hydraulic oil enters the valve block body through the first port 1, thereby supplying oil to the first and second oil circuits. In the first oil circuit, the dynamic priority valve 2 prioritizes supplying oil to the external steering valve during steering action, and then supplies oil to other external actuating valves. In the second oil circuit, the pressure reducing valve 5 reduces the pressure of the external hydraulic oil to the low pressure required by the pilot control system, and then supplies oil according to the actions of the parking valve 6, pilot valve 7, and high / low speed valves 8. This application combines the functions of the steering control system and the pilot control system on the same valve block, reducing the number of components, lowering costs, and achieving resource sharing. It features a simple structure, low cost, good pressure holding capability, and high system integration.

[0024] In some embodiments, a first bypass is also included, the inlet of which is connected to the outlet of the dynamic priority valve 2, the outlet of which is connected to a second oil port 9 provided on the valve block body, and a first relief valve 10 is connected to the first bypass.

[0025] In the above embodiments, by setting a first bypass and installing a first overflow valve 10 on the first bypass, the pressure of the first oil circuit can be effectively regulated, thereby preventing the pressure of the first oil circuit from being too high and affecting the normal operation of the system.

[0026] In some embodiments, a first filter 11 for filtering impurities is connected to the first bypass.

[0027] In the above embodiments, by providing a first filter 11 on the first bypass, impurity particles in the hydraulic oil on the first bypass can be effectively intercepted, ensuring the normal operation of the first relief valve 10.

[0028] In some embodiments, a second filter 12 for filtering is connected to the second oil line, and the second filter 12 is located between the first oil port 1 and the pressure reducing valve 5.

[0029] In the above embodiment, by setting a second filter 12 in the second oil circuit, impurity particles in the hydraulic oil in the second oil circuit can be effectively filtered, ensuring that the pressure reducing valve 5 is not affected by foreign objects in the hydraulic oil and thus operates normally.

[0030] In some embodiments, a check valve 13 is also connected to the second oil line, and the check valve 13 is located at the outlet end of the pressure reducing valve 5.

[0031] In the above embodiment, by providing a one-way valve 13 in the second oil circuit, it is possible to effectively prevent hydraulic oil from flowing back into the pressure reducing valve 5.

[0032] In some embodiments, a second bypass is also included, the inlet of which is connected to the outlet of the check valve 13, the outlet of which is connected to the second oil port 9 provided on the valve block body, and a second relief valve 14 is connected to the second bypass.

[0033] In the above embodiments, by setting a second bypass and a second overflow valve 14 on the second bypass, the maximum pressure of the pilot control system can be limited based on the second overflow valve 14, thus ensuring the normal operation of the pilot control system.

[0034] In some embodiments, the first oil circuit is connected to a first pressure testing port 15 disposed on the valve block body, and a first pressure measuring instrument (not shown in the figure) is connected to the first pressure testing port 15.

[0035] In the above embodiments, by setting a first pressure measuring port 15 on the valve block body, the pressure of the hydraulic oil in the first oil circuit can be monitored in real time based on the first pressure measuring instrument connected to the first pressure measuring port 15, thereby avoiding overpressure of the hydraulic oil in the first oil circuit.

[0036] In some embodiments, the second oil circuit is connected to a second pressure test port 16 disposed on the valve block body, and a second pressure gauge (not shown in the figure) is connected to the second pressure test port 16.

[0037] In the above embodiments, by setting a first pressure measuring port 16 on the valve block body, the pressure of the hydraulic oil in the first oil circuit can be monitored in real time based on the first pressure measuring instrument connected to the second pressure measuring port 16, thereby avoiding overpressure of the hydraulic oil in the second oil circuit.

[0038] In some embodiments, a fourth oil port is connected to the valve block body, and an accumulator 17 is connected to the fourth oil port.

[0039] In the above embodiments, by providing a fourth oil port on the valve block body, and based on the accumulator 17 provided on the fourth oil port, on the one hand, it can absorb the pressure fluctuations and shocks of the pilot control system, so that the pilot control system can operate smoothly, and on the other hand, it can store energy as a backup energy for the pilot control system, so as to supply oil to the pilot control system at any time.

[0040] In some embodiments, the valve block body is further provided with a third oil port 18, and a service brake valve (not shown in the figure) is connected to the third oil port 18 and arranged in parallel with the parking valve 6.

[0041] In the above embodiment, a third oil port 18 is provided on the valve block body, and a service brake valve provided on the third oil port 18 provides service brake hydraulic oil to the forklift in the working state.

[0042] The foregoing has provided a detailed description of a steering priority and pilot valve assembly for forklifts according to this utility model. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this utility model. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A steering priority and pilot valve assembly for a forklift truck, characterized in that, The valve includes a valve block body, on which a first oil port (1) is connected. The outlet end of the first oil port (1) is connected to a first oil passage and a second oil passage arranged in parallel, wherein: The first oil circuit is equipped with a dynamic priority valve (2), and the outlet of the dynamic priority valve (2) is connected to the third oil circuit (3) and the fourth oil circuit (4) which are connected in parallel. The third oil circuit (3) is connected to the external steering valve, and the fourth oil circuit (4) is connected to the external actuation valve. The second oil circuit is equipped with a pressure reducing valve (5), and the outlet of the pressure reducing valve (5) is connected to a parking valve (6), a pilot valve (7) and a high and low speed valve (8) arranged in parallel.

2. The steering priority and pilot valve assembly for a forklift truck as described in claim 1, characterized in that, It also includes a first bypass, the inlet of which is connected to the outlet of the dynamic priority valve (2), the outlet of which is connected to the second oil port (9) provided on the valve block body, and a first relief valve (10) is connected to the first bypass.

3. The steering priority and pilot valve assembly for a forklift truck as described in claim 2, characterized in that, The first bypass is connected to a first filter (11) for filtering impurities.

4. The steering priority and pilot valve assembly for a forklift truck as described in claim 1, characterized in that, A second filter (12) for filtration is connected to the second oil line, and the second filter (12) is located between the first oil port (1) and the pressure reducing valve (5).

5. The steering priority and pilot valve assembly for a forklift as described in claim 4, characterized in that, The second oil line is also connected to a check valve (13), which is located at the outlet end of the pressure reducing valve (5).

6. The steering priority and pilot valve assembly for a forklift truck as described in claim 5, characterized in that, It also includes a second bypass, the inlet of which is connected to the outlet of the check valve (13), the outlet of which is connected to the second oil port (9) provided on the valve block body, and a second relief valve (14) is connected to the second bypass.

7. The steering priority and pilot valve assembly for a forklift truck as described in claim 1, characterized in that, The first oil circuit is connected to the first pressure test port (15) set on the valve block body, and the first pressure test port (15) is connected to the first pressure tester.

8. The steering priority and pilot valve assembly for a forklift truck as described in claim 1, characterized in that, The second oil circuit is connected to the second pressure test port (16) set on the valve block body, and the second pressure test port (16) is connected to the second pressure tester.

9. The steering priority and pilot valve assembly for a forklift truck as described in any one of claims 1-8, characterized in that, The valve block body is connected to a fourth oil port, and the fourth oil port is connected to an accumulator (17).

10. The steering priority and pilot valve assembly for a forklift truck as described in claim 9, characterized in that, The valve block body is also provided with a third oil port (18), and a service brake valve is connected to the third oil port (18) and arranged in parallel with the parking valve (6).

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