Hydraulic control system and method for loading machine

Abstract

The invention discloses a hydraulic control system and method for a loading machine. The hydraulic control system comprises a movable arm oil cylinder, a bucket oil cylinder, a reversing valve set and a pump set. The pump set is connected with the movable arm oil cylinder and the bucket oil cylinder through the reversing valve set. The pump set comprises a first hydraulic pump, the reversing valve set comprises a first reversing valve and a second reversing valve, an oil outlet of the first hydraulic pump is connected with oil inlets of the first reversing valve and the second reversing valve, and a first working oil port of the first reversing valve is connected with a rodless cavity of the boom cylinder. A rod cavity of the movable arm oil cylinder is connected with a second working oil port of the first reversing valve; a first working oil port of the second reversing valve is connected with a rodless cavity of the bucket oil cylinder, and a rod cavity of the bucket oil cylinder is connected with a second working oil port of the second reversing valve. The balance valve is applied to a hydraulic control system, so that the problem of high-speed falling of a working device is solved, huge shock and jumping of the whole vehicle caused by violent impact are avoided, and danger and damage caused by vehicle balance loss are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of loader hydraulic control, and in particular to a loader hydraulic control system and method. Background Art

[0002] As a common construction machinery, loaders play an important role in engineering construction and other fields. During operation, loaders need to frequently perform actions such as arm raising, arm lowering, bucket shoveling, and bucket unloading, all of which are controlled and realized by the hydraulic system. However, existing loaders have many technical problems in hydraulic control, which seriously affect the performance, safety, and service life of loaders.

[0003] The existing hydraulic system of the working device of the loader mainly focuses on the basic control of the lifting and lowering actions of the working device, and realizes the conventional actions of the working device through the combination of hydraulic components, but does not provide an effective solution to the problem of rapid falling during the falling process of the working device and the resulting imbalance of the whole vehicle. In actual work, when the working device of the existing loader falls, it often falls rapidly due to the action of gravity and the lack of an effective speed control mechanism. For example, when the bucket falls after unloading, its falling speed is difficult to accurately control. In the case of no load, the impact caused by the rapid fall of the bucket will cause the rear of the whole vehicle to tilt up, and the rear wheels will be close to leaving the ground, and then fall quickly to produce a huge shock. If it is in the state of unloading, the rear wheels of the whole vehicle may completely lift off the ground, and as the working device falls to the bottom, the rear wheels hit the ground again, causing a bouncing phenomenon. This violent vibration and imbalance not only causes great harm to the driver's body, increases the driver's fatigue, affects driving comfort, but also seriously threatens the driver's safety. At the same time, it will also cause serious damage to the structure and components of the vehicle itself. The front and rear axles of the vehicle are prone to deformation, fracture and other damage under frequent impacts, and the wear of the articulated shaft is aggravated, affecting the stability and reliability of its connection. Some existing technical solutions attempt to solve the imbalance problem by improving the loader structure, but they often face problems such as difficulty in implementation, insignificant effect, and unstable performance. Simply adjusting the mechanical structure of the working device is difficult to fundamentally solve a series of problems caused by excessive falling speed and impact, and may have a negative impact on other performance of the working device. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a loader hydraulic control system and method. The present invention applies a balancing valve to the hydraulic control system on the basis that the existing structure is not easy to implement or is very costly, thereby solving the problem of the working device falling rapidly, avoiding the huge vibration and bouncing of the whole vehicle caused by severe impact, and avoiding the vehicle losing balance and causing danger and damage.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a loader hydraulic control system, the loader comprising a fuel tank, a steering system, a control system and a hydraulic control system, the hydraulic control system comprising: a boom cylinder, a bucket cylinder, a reversing valve group and a pump group; wherein the pump group is respectively connected to the boom cylinder and the bucket cylinder through the reversing valve group;

[0007] The pump group includes a first hydraulic pump, and the reversing valve group includes a first reversing valve and a second reversing valve. The oil outlet of the first hydraulic pump is respectively connected to the oil inlets of the first reversing valve and the second reversing valve. The first working oil port of the first reversing valve is connected to the rodless chamber of the boom cylinder, and the rod chamber of the boom cylinder is connected to the second working oil port of the first reversing valve; the first working oil port of the second reversing valve is connected to the rodless chamber of the bucket cylinder, and the rod chamber of the bucket cylinder is connected to the second working oil port of the second reversing valve.

[0008] As a further technical solution, a first balancing valve is connected between the first working oil port of the first reversing valve and the rodless chamber of the boom cylinder. The first working oil port of the first reversing valve is connected to one port of the first balancing valve, and the other port of the first balancing valve is connected to the rodless chamber of the boom cylinder.

[0009] As a further technical solution, a second balancing valve is connected between the first working oil port of the second reversing valve and the rodless chamber of the bucket cylinder. The first working oil port of the second reversing valve is connected to one port of the second balancing valve, and the other port of the second balancing valve is connected to the rodless chamber of the bucket cylinder.

[0010] As a further technical solution, the oil outlets of the first reversing valve and the second reversing valve are commonly connected to a radiator, one end of the radiator is respectively connected to the oil outlets of the first reversing valve and the second reversing valve, and the other end of the radiator is connected to the oil tank.

[0011] As a further technical solution, the pump group also includes a second hydraulic pump and a third hydraulic pump, the oil outlet of the third hydraulic pump is connected to a first overflow valve, one end of the first overflow valve is connected to the oil outlet of the third hydraulic pump, and the other end of the first overflow valve is connected to the oil tank.

[0012] As a further technical solution, the oil outlet of the second hydraulic pump is also connected to a priority valve, one end of the priority valve is connected to the oil outlet of the second hydraulic pump, and the other end of the priority valve is connected to the steering system; the oil outlet of the third hydraulic pump is also connected to the control system.

[0013] A loader hydraulic control method, based on a loader hydraulic control system described in any one of the first aspects, comprising: when the loader boom is lifted, the hydraulic oil outputted from the oil outlet of the first hydraulic pump enters the first reversing valve through the oil inlet of the first reversing valve, switches the first reversing valve to the left working state, and the hydraulic oil is then outputted from the first working oil outlet of the first reversing valve and enters the rodless chamber of the boom cylinder in one direction through the first balancing valve, and the rod chamber of the boom cylinder returns oil; when the loader boom falls, the hydraulic oil outputted from the oil outlet of the first hydraulic pump enters the first reversing valve through the oil inlet of the first reversing valve, switches the first reversing valve to the right working state, and the hydraulic oil is then outputted from the second working oil outlet of the first reversing valve and enters the rod chamber of the boom cylinder, and the rodless chamber of the boom cylinder returns oil through the first balancing valve.

[0014] As a further technical solution, when the loader bucket shovels up, the hydraulic oil output from the oil outlet of the first hydraulic pump enters the second reversing valve through the oil inlet of the second reversing valve, switches the second reversing valve to the left working state, and the hydraulic oil is then output through the first working oil port of the second reversing valve and enters the rodless chamber of the bucket cylinder in one direction through the second balancing valve, and the rod chamber of the bucket cylinder returns oil; when the loader bucket unloads, the hydraulic oil output from the oil outlet of the first hydraulic pump enters the second reversing valve through the oil inlet of the second reversing valve, switches the second reversing valve to the right working state, and the hydraulic oil is then output through the second working oil port of the second reversing valve and enters the rod chamber of the bucket cylinder, and the rodless chamber of the bucket cylinder returns oil through the second balancing valve.

[0015] As a further technical solution, the return oil of the boom cylinder flows back to the oil tank after the heat is dissipated by the radiator.

[0016] As a further technical solution, the return oil of the bucket cylinder flows back to the oil tank after the heat is dissipated by the radiator.

[0017] One or more technical solutions of the present invention have the following beneficial effects:

[0018] (1) The present invention introduces a balancing valve into the hydraulic control system. When the loader boom falls and the loader bucket unloads, the rodless chamber of the boom cylinder and the rodless chamber of the bucket cylinder return oil after passing through the balancing valve, realizing precise control of the bucket unloading and boom falling speed, effectively preventing the phenomenon of rapid speed during unloading and falling, and ensuring the smooth and safe operation of the working device. At the same time, it successfully eliminates the huge vibration and bouncing of the whole vehicle caused by the rapid fall of the bucket and boom, greatly protecting important components such as the drive axle, tires, frame, and articulation from huge impact damage, and effectively reducing the damage to other components of the whole vehicle due to impact, thereby extending the service life of the vehicle.

[0019] (2) The present invention makes the vehicle run and operate more smoothly, effectively avoids the danger faced by the driver due to severe vibration and imbalance of the vehicle, provides a safer and more comfortable working environment for the driver, and improves work efficiency. At the same time, the vehicle balance is guaranteed from the vehicle hardware, without relying on the driver's proficiency, experience, and driving age to ensure that the vehicle does not become unbalanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 It is a schematic diagram of the hydraulic control system of the loader of the present invention;

[0022] Figure 2 It is a schematic diagram of the overall structure of the loader of the present invention;

[0023] Among them: 1. Boom cylinder; 2. Bucket cylinder; 3. First balancing valve; 4. Second balancing valve; 5. First reversing valve; 6. Second reversing valve; 7. Third reversing valve; 8. First hydraulic pump; 9. Second hydraulic pump; 10. Third hydraulic pump; 11. First overflow valve; 12. Priority valve; 13. Filter; 14. Radiator; 15. Pressure reducing valve; 16. Second overflow valve; 17. Accumulator; 18. First handle; 19. Foot valve; 20. Steering gear; 21. Steering cylinder; 22. Second handle. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0025] Embodiment 1

[0026] This embodiment provides a loader hydraulic control system. The existing loader working device includes a fuel tank, a steering system, a control system and a hydraulic control system. The technical solution provided by this embodiment is to creatively improve the hydraulic control system on the basis that the existing structure is not easy to implement or the cost is very high. Figure 1As shown, the hydraulic control system includes: a boom cylinder 1, a bucket cylinder 2, a reversing valve group and a pump group, wherein the pump group is respectively connected to the boom cylinder 1 and the bucket cylinder 2 through the reversing valve group. Specifically: the pump group includes a first hydraulic pump 8, a second hydraulic pump 9 and a third hydraulic pump 10, the reversing valve group includes a first reversing valve 5, a second reversing valve 6 and a third reversing valve 7 (spare), the oil outlet of the first hydraulic pump 8 is respectively connected to the oil inlet of the first reversing valve 5 and the second reversing valve 6, the first working oil port of the first reversing valve 5 is connected to the rodless chamber of the boom cylinder 1, and the rod chamber of the boom cylinder 1 is connected to the second working oil port of the first reversing valve 5; the first working oil port of the second reversing valve 6 is connected to the rodless chamber of the bucket cylinder 2, and the rod chamber of the bucket cylinder 2 is connected to the second working oil port of the second reversing valve 6. In this embodiment, in order to accurately control the bucket unloading and boom falling speed, prevent the bucket unloading and boom falling process from speeding up, ensure the working device to move smoothly and safely, and eliminate the huge vibration and bouncing of the whole vehicle caused by the rapid falling of the bucket and boom, a balancing valve is introduced. Specifically: Figure 1 As shown, a first balancing valve 3 is connected between the first working oil port of the first reversing valve 5 and the rodless chamber of the boom cylinder 1, wherein the first working oil port of the first reversing valve 5 is connected to one port of the first balancing valve 3, and the other port of the first balancing valve 3 is connected to the rodless chamber of the boom cylinder 1. At the same time, a second balancing valve 4 is connected between the first working oil port of the second reversing valve 6 and the rodless chamber of the bucket cylinder 2, wherein the first working oil port of the second reversing valve 6 is connected to one port of the second balancing valve 4, and the other port of the second balancing valve 4 is connected to the rodless chamber of the bucket cylinder 2. In this embodiment, Figure 1 As shown, the oil outlets of the first reversing valve 5 and the second reversing valve 6 are commonly connected to a radiator 14, one end of the radiator 14 is respectively connected to the oil outlets of the first reversing valve 5 and the second reversing valve 6, and the other end of the radiator 14 is connected to the oil tank.

[0027] like Figure 1 As shown, in this embodiment, the oil outlet of the third hydraulic pump 10 is connected to the first overflow valve 11, the function of the first overflow valve is to release pressure, one end of the first overflow valve 11 is connected to the oil outlet of the third hydraulic pump 10, and the other end of the first overflow valve 11 is connected to the oil tank. The oil outlet of the second hydraulic pump 9 is also connected to the priority valve 12, the priority valve functions to prioritize the steering oil supply, one end of the priority valve 12 is connected to the oil outlet of the second hydraulic pump 9, and the other end of the priority valve 12 is connected to the steering system, and the oil outlet of the third hydraulic pump 10 is also connected to the control system.

[0028] In this embodiment, if Figure 1As shown, hydraulic control is to use the first hydraulic pump 8 to output hydraulic oil to push the first reversing valve 3 and the second reversing valve 4, and operate the first reversing valve 3 and the second reversing valve 4 to switch. The second hydraulic pump 9 is connected to the priority valve 12, and the priority valve 12 is connected to the steering system. Specifically, the steering system includes a steering gear 20 and a steering cylinder 21 connected to the steering gear, and the priority valve 12 is connected to the steering gear. The oil outlet of the third hydraulic pump 10 is connected to the first overflow valve 11 and the control system. Specifically, the oil outlet of the third hydraulic pump 10 is connected to the pressure reducing valve 15 in the control system. One end of the pressure reducing valve 15 is connected to the second overflow valve 16 and leads to the radiator. The pressure reducing valve is also connected to the accumulator 17 bypass, and then leads to the foot valve 19 and the two-link handle 18. The two-link handle is respectively connected to the first reversing valve 5 and the second reversing valve 6 to switch, push the valve core to move, and the first reversing valve 5 and the second reversing valve 6 are switched.

[0029] Embodiment 2

[0030] A loader hydraulic control method mentioned in this embodiment is based on a loader hydraulic control system described in Embodiment 1, and the method includes:

[0031] When the loader boom is raised, the first handle 18 is operated, and the third hydraulic pump 10 supplies oil to the first handle, and the valve core of the first reversing valve 5 is pushed to the left by operating the oil circuit. The reversing valve works in the left position, and the hydraulic oil output from the oil outlet of the first hydraulic pump enters the first reversing valve through the oil inlet of the first reversing valve. The third hydraulic pump 10 switches the first reversing valve to the left working state, and the hydraulic oil is output through the first working oil port of the first reversing valve and enters the rodless chamber of the boom cylinder in one direction through the first balancing valve. Oil returns to the rod chamber; when the loader boom falls, operate the first handle 18, the third hydraulic pump 10 supplies oil to the first handle, and pushes the valve core of the first reversing valve 5 to move to the right through the operating oil circuit, and the reversing valve works in the right position. The hydraulic oil output from the oil outlet of the first hydraulic pump enters the first reversing valve through the oil inlet of the first reversing valve, and switches the first reversing valve to the right working state. The hydraulic oil is then output through the second working oil port of the first reversing valve into the rod chamber of the boom cylinder, and the rodless chamber of the boom cylinder returns oil through the first balancing valve.

[0032] When the loader bucket is shoveled up, the second handle 22 is operated, and the third hydraulic pump 10 supplies oil to the second handle, and the valve core of the second reversing valve 6 is pushed to the left by controlling the oil circuit. The reversing valve works in the left position, and the hydraulic oil output from the oil outlet of the first hydraulic pump enters the second reversing valve through the oil inlet of the second reversing valve, switching the second reversing valve to the left working state. The hydraulic oil is then output through the first working oil port of the second reversing valve and enters the rodless chamber of the bucket cylinder in one direction through the second balancing valve, and the rod chamber of the bucket cylinder returns oil. When the loader bucket is unloading, the second handle 22 is operated, and the third hydraulic pump 10 supplies oil to the second handle, and the valve core of the second reversing valve 6 is pushed to the right by controlling the oil circuit, and the reversing valve works in the right position. The hydraulic oil output from the oil outlet of the first hydraulic pump enters the second reversing valve through the oil inlet of the second reversing valve, and the second reversing valve is switched to the right working state. The hydraulic oil is then output through the second working oil port of the second reversing valve into the rod chamber of the bucket cylinder, and the rodless chamber of the bucket cylinder returns oil through the second balance valve. Among them, the return oil of the boom cylinder and the bucket cylinder flows back to the oil tank after being cooled by the radiator.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A loader hydraulic control system, the loader comprising a fuel tank, a steering system, a control system and a hydraulic control system, characterized in that: The hydraulic control system comprises: a boom cylinder, a bucket cylinder, a reversing valve group and a pump group; wherein the pump group is respectively connected to the boom cylinder and the bucket cylinder through the reversing valve group; The pump group includes a first hydraulic pump, and the reversing valve group includes a first reversing valve and a second reversing valve. The oil outlet of the first hydraulic pump is respectively connected to the oil inlets of the first reversing valve and the second reversing valve. The first working oil port of the first reversing valve is connected to the rodless chamber of the boom cylinder, and the rod chamber of the boom cylinder is connected to the second working oil port of the first reversing valve; the first working oil port of the second reversing valve is connected to the rodless chamber of the bucket cylinder, and the rod chamber of the bucket cylinder is connected to the second working oil port of the second reversing valve.

2. A loader hydraulic control system according to claim 1, characterized in that: A first balancing valve is connected between the first working oil port of the first reversing valve and the rodless chamber of the boom cylinder. The first working oil port of the first reversing valve is connected to one port of the first balancing valve, and the other port of the first balancing valve is connected to the rodless chamber of the boom cylinder.

3. A loader hydraulic control system as claimed in claim 1, characterized in that: A second balancing valve is connected between the first working oil port of the second reversing valve and the rodless chamber of the bucket cylinder. The first working oil port of the second reversing valve is connected to one port of the second balancing valve, and the other port of the second balancing valve is connected to the rodless chamber of the bucket cylinder.

4. A loader hydraulic control system as claimed in claim 1, characterized in that: The oil outlets of the first reversing valve and the second reversing valve are commonly connected to a radiator, one end of the radiator is respectively connected to the oil outlets of the first reversing valve and the second reversing valve, and the other end of the radiator is connected to an oil tank.

5. A loader hydraulic control system as claimed in claim 1, characterized in that: The pump group also includes a second hydraulic pump and a third hydraulic pump. The oil outlet of the third hydraulic pump is connected to a first overflow valve. One end of the first overflow valve is connected to the oil outlet of the third hydraulic pump, and the other end of the first overflow valve is connected to the oil tank.

6. A loader hydraulic control system as claimed in claim 5, characterized in that: The oil outlet of the second hydraulic pump is also connected to a priority valve, one end of the priority valve is connected to the oil outlet of the second hydraulic pump, and the other end of the priority valve is connected to the steering system; the oil outlet of the third hydraulic pump is also connected to the control system.

7. A loader hydraulic control method, based on a loader hydraulic control system according to any one of claims 1 to 6, characterized in that: include: When the loader's boom is lifted, the hydraulic oil output from the oil outlet of the first hydraulic pump enters the first reversing valve through the oil inlet of the first reversing valve, switching the first reversing valve to the left working state, and the hydraulic oil is then output through the first working oil port of the first reversing valve and enters the rodless chamber of the boom cylinder in one direction through the first balancing valve, and the rod chamber of the boom cylinder returns oil; when the loader's boom is lowered, the hydraulic oil output from the oil outlet of the first hydraulic pump enters the first reversing valve through the oil inlet of the first reversing valve, switching the first reversing valve to the right working state, and the hydraulic oil is then output through the second working oil port of the first reversing valve and enters the rod chamber of the boom cylinder, and the rodless chamber of the boom cylinder returns oil through the first balancing valve.

8. A loader hydraulic control method as claimed in claim 7, characterized in that: When the loader bucket shovels up, the hydraulic oil output from the oil outlet of the first hydraulic pump enters the second reversing valve through the oil inlet of the second reversing valve, switches the second reversing valve to the left working state, and the hydraulic oil is then output through the first working oil port of the second reversing valve and enters the rodless chamber of the bucket cylinder in one direction through the second balancing valve, and the rod chamber of the bucket cylinder returns oil; when the loader bucket unloads, the hydraulic oil output from the oil outlet of the first hydraulic pump enters the second reversing valve through the oil inlet of the second reversing valve, switches the second reversing valve to the right working state, and the hydraulic oil is then output through the second working oil port of the second reversing valve and enters the rod chamber of the bucket cylinder, and the rodless chamber of the bucket cylinder returns oil through the second balancing valve.

9. A loader hydraulic control method as claimed in claim 7, characterized in that: The return oil of the boom cylinder flows back to the oil tank after the heat is dissipated by the radiator.

10. A loader hydraulic control method as claimed in claim 8, characterized in that: The return oil of the bucket cylinder flows back to the oil tank after the heat is dissipated by the radiator.

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