Hydraulic system for boom and bucket of loading machine and using method

Abstract

The invention discloses a hydraulic system for an arm support and a bucket of a loader and a using method, and belongs to the technical field of loaders, the hydraulic system comprises an arm support oil cylinder, a bucket oil cylinder and a reversing valve bank, the reversing valve bank comprises a first reversing valve, a second reversing valve and a third reversing valve, the first reversing valve, the second reversing valve and the third reversing valve are connected through pipelines; one end of the boom oil cylinder is connected with one end of the first one-way throttle valve, and the other end of the first one-way throttle valve is connected with the first reversing valve; one end of the bucket oil cylinder is connected with one end of the second one-way throttle valve, and the other end of the second one-way throttle valve is connected with the second reversing valve; and one end of the second reversing valve is connected with one end of the third reversing valve. The cantilever crane and the bucket can be prevented from falling at high speed, huge shock and jumping caused by violent impact are avoided, and a vehicle is prevented from losing balance. The comfort and safety of a driver are improved, the safety of the vehicle is improved, and the stability of the vehicle is further guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of loaders, and in particular relates to a hydraulic system for a loader arm and a bucket and a use method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Loaders are earthwork machines widely used in construction projects such as roads, railways, buildings, hydropower, ports, and mines. They are mainly used to shovel bulk materials such as soil, sand, lime, and coal, and can also do light shoveling of ore and hard soil. By replacing different auxiliary working devices, they can also do bulldozing, lifting, and loading and unloading of other materials such as wood.

[0004] The existing loader working device falls rapidly during the falling process, and the impact and inertia after reaching the limit cause the vehicle to lose balance. It is difficult to solve the problem of the working device falling rapidly by improving the structure. The rapid fall causes severe vibration and jumping to the vehicle. Even in the case of no load, the impact caused by the rapid fall of the bucket causes the rear of the vehicle to tilt up, and the rear wheels are about to leave the ground, and then fall immediately, causing a huge shock. If the load is unloaded, this speed causes the rear wheels of the vehicle to lift off the ground. As the working device falls to the bottom, the rear wheels immediately hit the ground again, causing jumping. The rear wheels of the vehicle hit the ground rapidly under the action of gravity, which poses a threat to the safety of the driver and the vehicle, and also causes impact damage to the front and rear axles, articulated shafts and other accessories of the vehicle. Summary of the invention

[0005] In view of the above problems, the present invention provides a hydraulic system and a method for using a loader boom and bucket, which can prevent the boom and bucket from falling rapidly, avoid huge shocks and bouncing caused by severe impacts, and prevent the vehicle from losing balance, thereby improving the comfort and safety of the driver, improving the safety of the vehicle, and thus ensuring the stability of the vehicle.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A hydraulic system for a loader arm and bucket, comprising an arm cylinder, a bucket cylinder and a reversing valve group, wherein the reversing valve group comprises a first reversing valve, a second reversing valve and a third reversing valve, wherein the first reversing valve, the second reversing valve and the third reversing valve are connected by a pipeline;

[0008] One end of the arm cylinder is connected to one end of the first one-way throttle valve, and the other end of the first one-way throttle valve is connected to the first reversing valve; one end of the bucket cylinder is connected to one end of the second one-way throttle valve, and the other end of the second one-way throttle valve is connected to the second reversing valve; one end of the second reversing valve is connected to one end of the third reversing valve, and the other end of the third reversing valve is connected to the third oil pump, a second oil pump is set at one end of the third oil pump, and a first oil pump is set at one end of the second oil pump.

[0009] Furthermore, the boom cylinder includes a first boom cylinder and a second boom cylinder, and the first boom cylinder and the second boom cylinder are connected by a pipeline.

[0010] Further, the first boom oil cylinder is connected to a first one-way throttle valve, the first one-way throttle valve is connected to a first reversing valve, and the second boom oil cylinder is connected to the first reversing valve.

[0011] Furthermore, the bucket cylinder includes a first bucket cylinder and a second bucket cylinder, and the first bucket cylinder and the second bucket cylinder are connected by a pipeline.

[0012] Furthermore, the first bucket cylinder is connected to a second one-way throttle valve, the second one-way throttle valve is connected to a second reversing valve, and the second bucket cylinder is connected to a second reversing valve.

[0013] Furthermore, one ends of the first oil pump, the second oil pump and the third oil pump are connected to each other, the connection positions of the first oil pump, the second oil pump and the third oil pump are connected to the first filter, and the first filter is connected to the oil tank.

[0014] Furthermore, an overflow valve is arranged on one side of the first oil pump, one end of the overflow valve is connected to the other end of the first oil pump, and the other end of the overflow valve is connected to the oil tank.

[0015] Furthermore, the other end of the second oil pump is connected to one end of the priority valve, and the other end of the priority valve is connected to the reversing valve group.

[0016] Furthermore, a radiator is arranged on one side of the third oil pump, one end of the radiator is connected to one end of the second filter, the other end of the second filter is connected to the oil tank; the other end of the radiator is connected to the reversing valve group.

[0017] A hydraulic system for a loader boom and bucket comprises the following steps:

[0018] When the bucket is raised, the oil outlet of the third oil pump flows through the left valve position of the second reversing valve and then flows into the rodless chamber of the bucket cylinder through the second one-way throttle valve, pushing the piston rod to move rightward, and the oil returns to the rod chamber of the bucket cylinder and flows back to the oil tank through the second reversing valve;

[0019] When the bucket is unloading, the oil outlet of the third oil pump flows through the right valve position of the second reversing valve and then through the second one-way throttle valve to the rod chamber of the bucket cylinder, pushing the piston rod to move left, and the rodless chamber of the bucket cylinder returns oil. At this time, if the bucket is running at high speed, the oil in the rodless chamber passes through the second one-way throttle valve, and the valve core of the throttle valve moves, reducing the outlet area of ​​the oil, so that the bucket cylinder generates back pressure, thereby slowing down the fall of the bucket;

[0020] If the boom cylinder speeds up when the boom is lowered, the first one-way throttle valve in the rodless chamber will also reduce the flow area of ​​its oil outlet, slowing down the speed of the boom.

[0021] Compared with the prior art, the present invention has the following advantages and positive effects:

[0022] The present invention is provided with a bucket cylinder, an arm cylinder, a one-way throttle valve and a reversing valve. When the bucket cylinder and the arm cylinder are speeding up, the speed of the bucket cylinder and the arm cylinder is controlled by the one-way throttle valve, thereby effectively preventing the bucket and the arm from falling at a high speed, eliminating the huge shock and bouncing caused by the bucket and the arm at a high speed, protecting the drive axle, tires, frame, and important hinged parts from huge impact damage, and other parts of the whole vehicle from impact damage, eliminating the huge shock and bouncing of the vehicle so that the vehicle runs smoothly, avoiding danger for the driver, protecting the vehicle from impact damage, and ensuring the balance of the vehicle from the vehicle hardware instead of relying on the driver's proficiency, experience, and driving age to ensure that the vehicle is not unbalanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 is a hydraulic system diagram for a loader boom and bucket of the present invention;

[0025] Figure 2 is a schematic diagram of the control system and steering system of the present invention;

[0026] Figure 3 It is the installation position diagram of the arm cylinder and the bucket cylinder of the present invention;

[0027] In the figure: 1. first boom cylinder; 2. second boom cylinder; 3. first bucket cylinder; 4. second bucket cylinder; 5. first one-way throttle valve; 6. second one-way throttle valve; 7. first reversing valve; 8. second reversing valve; 9. third reversing valve; 10. priority valve; 11. overflow valve; 12. first oil pump; 13. second oil pump; 14. third oil pump; 15. first filter; 16. second filter; 17. radiator; 18. steering system; 19. control system. DETAILED DESCRIPTION

[0028] 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 herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] The existing loader working device falls rapidly during the falling process, and the impact and inertia after reaching the limit cause the vehicle to lose balance. It is difficult to solve the problem of the working device falling rapidly by improving the structure. The rapid fall causes severe vibration and jumping to the vehicle. Even in the case of no load, the impact caused by the rapid fall of the bucket causes the rear of the vehicle to tilt up, and the rear wheels are about to leave the ground, and then fall immediately, causing a huge shock. If the load is unloaded, this speed causes the rear wheels of the vehicle to lift off the ground. As the working device falls to the bottom, the rear wheels immediately hit the ground again, causing jumping. The rear wheels of the vehicle hit the ground rapidly under the action of gravity, which poses a threat to the safety of the driver and the vehicle, and also causes impact damage to the front and rear axles, articulated shafts and other accessories of the vehicle.

[0030] Embodiment 1:

[0031] The present invention is described in detail below in conjunction with the accompanying drawings. The present embodiment discloses a hydraulic system for a loader boom and a bucket, such as Figure 1 and Figure 2 As shown, it includes a boom cylinder, a bucket cylinder and a reversing valve group, the reversing valve group includes a first reversing valve, a second reversing valve and a third reversing valve, and the first reversing valve, the second reversing valve and the third reversing valve are connected by a pipeline;

[0032] One end of the boom cylinder is connected to one end of the first one-way throttle valve, and the other end of the first one-way throttle valve is connected to the first reversing valve; one end of the bucket cylinder is connected to one end of the second one-way throttle valve, and the other end of the second one-way throttle valve is connected to the second reversing valve; one end of the second reversing valve is connected to one end of the third reversing valve, and the other end of the third reversing valve is connected to the third oil pump, a second oil pump is set at one end of the third oil pump, and a first oil pump is set at one end of the second oil pump.

[0033] The first-stage boom and the second-stage boom are collectively referred to as the boom cylinder and bucket cylinder. At present, conventional loaders only have the first-stage boom, and the second-stage boom belongs to special application fields and is made to achieve specific functions.

[0034] The present invention can be applied to telescopic booms, cascade booms and Figure 2As shown in the boom, etc., as long as there is an upswing, there is a downswing (whether it is a bucket, a primary boom, a secondary boom and a primary telescopic arm, a secondary telescopic arm, a third level, a fourth level, ... N levels), each level needs to be driven by a cylinder, so there are multiple levels, and the hydraulic system of the present invention can be used to decelerate during descent, so that the loader is in a stable and unbalanced state, and is not limited to the differences in the external form of the working device of the loader.

[0035] The present invention is provided with a bucket cylinder, an arm cylinder, a one-way throttle valve and a reversing valve. When the bucket cylinder and the arm cylinder are speeding up, the speed of the bucket cylinder and the arm cylinder is controlled by the one-way throttle valve, thereby effectively preventing the bucket and the arm from falling at a high speed, eliminating the huge shock and bouncing caused by the bucket and the arm at a high speed, protecting the drive axle, tires, frame, and important hinged parts from huge impact damage, and other parts of the whole vehicle from impact damage, eliminating the huge shock and bouncing of the vehicle so that the vehicle runs smoothly, avoiding danger for the driver, protecting the vehicle from impact damage, and ensuring the balance of the vehicle from the vehicle hardware instead of relying on the driver's proficiency, experience, and driving age to ensure that the vehicle is not unbalanced.

[0036] The arm cylinder includes a first arm cylinder and a second arm cylinder, and the first arm cylinder and the second arm cylinder are connected by a pipeline. The first arm cylinder is connected to a first one-way throttle valve, the first one-way throttle valve is connected to a first reversing valve, and the second arm cylinder is connected to the first reversing valve. The bucket cylinder includes a first bucket cylinder and a second bucket cylinder, and the first bucket cylinder and the second bucket cylinder are connected by a pipeline. The first bucket cylinder is connected to the second one-way throttle valve, the second one-way throttle valve is connected to the second reversing valve, and the second bucket cylinder is connected to the second reversing valve.

[0037] A one-way throttle valve is a fluid control device, and its main function is to control the flow of the fluid by changing the throttle section or throttle length. It combines the characteristics of a throttle valve and a one-way valve, allowing the fluid to flow in a specific direction, while preventing the fluid from passing in the opposite direction. The present invention controls the flow rate through the first one-way throttle valve and the second one-way throttle valve. When the bucket cylinder or the arm cylinder is running at high speed, the flow rate is controlled to control the speed, thereby preventing the bucket and the arm from running too fast, thereby avoiding the huge shock and jumping caused by the violent impact caused by the high speed, and preventing the vehicle from losing balance.

[0038] Allow the working device to fall steadily and quickly without causing huge vibrations and bounces in the vehicle, reduce impact damage to the main components such as the front and rear drive axles, transmission and articulation, which will occur to all parts of the vehicle, and improve driving comfort.

[0039] One end of the first oil pump, the second oil pump and the third oil pump are connected to each other, and the connection position of the first oil pump, the second oil pump and the third oil pump is connected to the first filter, and the first filter is connected to the oil tank. The oil pump is used to pump hydraulic oil, and the hydraulic oil is delivered to the reversing valve and then to the oil cylinder; the first filter is used to filter the hydraulic oil to prevent impurities in the hydraulic oil.

[0040] The first oil pump provides the power source and pressure oil to the working device, i.e., the boom cylinder and bucket cylinder. According to Pascal's law, the boom and bucket are driven by the cylinder to complete the predetermined action and realize the specific function. The second oil pump supplies oil to the steering cylinder, and the third oil pump supplies oil to the hydraulic control valve. The multi-way valve reversing in the figure is driven by the third oil pump to supply oil to the pilot control valve and then to the multi-way valve to drive the multi-way valve reversing.

[0041] A relief valve is set on one side of the first oil pump, one end of the relief valve is connected to the other end of the first oil pump, and the other end of the relief valve is connected to the oil tank. The relief valve plays a safety protection role in the system. When the system pressure exceeds the specified value, the safety valve opens and discharges part of the gas in the system into the atmosphere, so that the system pressure does not exceed the allowable value, thereby ensuring that the system does not cause accidents due to excessive pressure.

[0042] The other end of the second oil pump is connected to one end of the priority valve, and the other end of the priority valve is connected to the reversing valve group. The priority valve is a device used to adjust the flow rate, mainly used to control the flow of two or more components. It is essentially similar to a hydraulic speed regulating valve, which can allocate part of the oil pump output to a certain oil circuit, regardless of the working pressure of this oil circuit, and the remaining pressure oil is allocated to other oil circuits of the hydraulic system.

[0043] The overflow valve is a valve that protects the system pressure from being constant. When the system pressure is higher than the set pressure of the overflow valve, the overflow valve oil drain port will open to keep the system at the set pressure. The overflow valve protects the pump from overpressure and protects the pipeline, valve, and actuator from being damaged by overpressure.

[0044] The function of the priority valve is to prioritize steering, that is, when the hydraulic pump does not supply enough oil for steering, it will stop supplying oil to the multi-way valve to ensure the steering of the steering cylinder.

[0045] like Figure 2 As shown, the control system and steering system of the hydraulic system of the present invention are the existing structures, wherein the control system is the system that provides the power source to the hydraulic control valve. The steering system is that the priority valve provides power oil to the steering gear. When there is no steering action, the priority valve supplies oil to the multi-way valve. When steering is required, the steering gear is given priority to oil supply.

[0046] A radiator is arranged on one side of the third oil pump, one end of the radiator is connected to one end of the second filter, the other end of the second filter is connected to the oil tank; the other end of the radiator is connected to the reversing valve group. The radiator is used to dissipate heat to prevent the hydraulic oil in the system pipeline from being too hot.

[0047] Embodiment 2:

[0048] A hydraulic system for a loader boom and bucket comprises the following steps:

[0049] When the bucket is raised, the oil outlet of the third oil pump flows through the left valve position of the second reversing valve and then flows into the rodless chamber of the bucket cylinder through the second one-way throttle valve, pushing the piston rod to move rightward, and the oil returns to the rod chamber of the bucket cylinder and flows back to the oil tank through the second reversing valve;

[0050] When the bucket is unloading, the oil outlet of the third oil pump flows through the right valve position of the second reversing valve and then through the second one-way throttle valve to the rod chamber of the bucket cylinder, pushing the piston rod to move left, and the rodless chamber of the bucket cylinder returns oil. At this time, if the bucket is running at high speed, the oil in the rodless chamber passes through the second one-way throttle valve, and the valve core of the throttle valve moves, reducing the outlet area of ​​the oil, so that the bucket cylinder generates back pressure, thereby slowing down the fall of the bucket;

[0051] If the boom cylinder speeds up when the boom is lowered, the first one-way throttle valve in the rodless chamber will also reduce the flow area of ​​its oil outlet, slowing down the speed of the boom.

[0052] The speed of the arm is slowed down by the valve core structure of the one-way throttle valve. When rising, the valve core of the one-way throttle valve will not hinder the flow of oil. When the descending speed reaches overspeed, the pressure of the pressure oil reaches a value higher than the preset force of the valve core spring, and the valve core will be pressed downward. The downward pressure of the valve core will block the oil port on the valve core, and only a part of the pores will flow. In this way, a certain back pressure, that is, thrust, is generated when the rodless chamber returns oil to prevent the piston rod from falling back.

[0053] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A hydraulic system for a loader boom and bucket, characterized in that: It includes a boom oil cylinder, a bucket oil cylinder and a reversing valve group, wherein the reversing valve group includes a first reversing valve, a second reversing valve and a third reversing valve, and the first reversing valve, the second reversing valve and the third reversing valve are connected by a pipeline; One end of the arm cylinder is connected to one end of the first one-way throttle valve, and the other end of the first one-way throttle valve is connected to the first reversing valve; one end of the bucket cylinder is connected to one end of the second one-way throttle valve, and the other end of the second one-way throttle valve is connected to the second reversing valve; one end of the second reversing valve is connected to one end of the third reversing valve, and the other end of the third reversing valve is connected to the third oil pump, a second oil pump is set at one end of the third oil pump, and a first oil pump is set at one end of the second oil pump.

2. A hydraulic system for a loader boom and bucket as claimed in claim 1, characterized in that: The boom oil cylinder comprises a first boom oil cylinder and a second boom oil cylinder, and the first boom oil cylinder and the second boom oil cylinder are connected by a pipeline.

3. A hydraulic system for a loader boom and bucket as claimed in claim 2, characterized in that: The first boom oil cylinder is connected to a first one-way throttle valve, the first one-way throttle valve is connected to a first reversing valve, and the second boom oil cylinder is connected to the first reversing valve.

4. A hydraulic system for a loader boom and bucket as claimed in claim 1, characterized in that: The bucket cylinder comprises a first bucket cylinder and a second bucket cylinder, and the first bucket cylinder and the second bucket cylinder are connected by a pipeline.

5. A hydraulic system for a loader boom and bucket as claimed in claim 4, characterized in that: The first bucket oil cylinder is connected to the second one-way throttle valve, the second one-way throttle valve is connected to the second reversing valve, and the second bucket oil cylinder is connected to the second reversing valve.

6. A hydraulic system for a loader boom and bucket as claimed in claim 1, characterized in that: One ends of the first oil pump, the second oil pump and the third oil pump are connected to each other, the connection positions of the first oil pump, the second oil pump and the third oil pump are connected to the first filter, and the first filter is connected to the oil tank.

7. A hydraulic system for a loader boom and bucket as claimed in claim 6, characterized in that: An overflow valve is arranged on one side of the first oil pump, one end of the overflow valve is connected to the other end of the first oil pump, and the other end of the overflow valve is connected to the oil tank.

8. A hydraulic system for a loader boom and bucket as claimed in claim 7, characterized in that: The other end of the second oil pump is connected to one end of the priority valve, and the other end of the priority valve is connected to the reversing valve group.

9. A hydraulic system for a loader boom and bucket as claimed in claim 8, characterized in that: A radiator is arranged on one side of the third oil pump, one end of the radiator is connected to one end of the second filter, the other end of the second filter is connected to the oil tank; the other end of the radiator is connected to the reversing valve group.

10. A hydraulic system for a loader boom and bucket according to any one of claims 1 to 9, characterized in that: The following steps are involved: When the bucket is raised, the oil outlet of the third oil pump flows through the left valve position of the second reversing valve and then flows into the rodless chamber of the bucket cylinder through the second one-way throttle valve, pushing the piston rod to move rightward, and the oil returns to the rod chamber of the bucket cylinder and flows back to the oil tank through the second reversing valve; When the bucket is unloading, the oil outlet of the third oil pump flows through the right valve position of the second reversing valve and then through the second one-way throttle valve to the rod chamber of the bucket cylinder, pushing the piston rod to move left, and the rodless chamber of the bucket cylinder returns oil. At this time, if the bucket is running at high speed, the oil in the rodless chamber passes through the second one-way throttle valve, and the valve core of the throttle valve moves, reducing the outlet area of ​​the oil, so that the bucket cylinder generates back pressure, thereby slowing down the fall of the bucket; If the boom cylinder speeds up when the boom is lowered, the first one-way throttle valve in the rodless chamber will also reduce the flow area of ​​its oil outlet, slowing down the speed of the boom.

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