A loader hydraulic control system and method

Abstract

The application discloses a loader hydraulic control system and method, which comprises a boom cylinder, a bucket cylinder, a reversing valve group and a pump group; the pump group is connected with the boom cylinder and the bucket cylinder through the reversing valve group; the pump group comprises a first hydraulic pump, the reversing valve group comprises a first reversing valve and a second reversing valve, the oil outlet of the first hydraulic pump is connected with the oil inlets of the first reversing valve and the second reversing valve respectively, the first working oil port of the first reversing valve is connected with the rodless cavity of the boom cylinder, and the rod cavity of the boom cylinder is connected with the second working oil port of the first reversing valve; the first working oil port of the second reversing valve is connected with the rodless cavity of the bucket cylinder, and the rod cavity of the bucket cylinder is connected with the second working oil port of the second reversing valve. The application applies the balance valve to the hydraulic control system, solves the problem of rapid falling of a working device, avoids the whole vehicle from being violently impacted and jumping, and avoids the vehicle from losing balance and causing danger and damage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control of loaders, and particularly relates to a hydraulic control system and method of a loader. BACKGROUND

[0002] As a common engineering machinery, the loader plays an important role in the field of engineering construction. During the working process, the loader needs to frequently perform actions such as lifting of a movable arm, falling of the movable arm, scooping of a bucket, and unloading of the bucket, which are all controlled and implemented by a hydraulic system. However, the existing loader has many technical problems in the hydraulic control, which seriously affect the performance, safety, and service life of the loader.

[0003] The existing hydraulic system of the working device of the loader mainly focuses on the basic control of the lifting and falling actions of the working device, and the conventional actions of the working device are implemented through the combination of hydraulic elements, but no effective solution is provided for the rapid falling of the working device during the falling process and the imbalance of the whole vehicle caused thereby. In actual work, when the working device of the existing loader falls, due to the action of gravity and the lack of effective speed control mechanism, the rapid falling often occurs. For example, when the bucket falls after unloading, the falling speed is difficult to accurately control. In the case of empty load, the impact caused by the rapid falling of the bucket will make the rear of the whole vehicle rise, and the rear wheels will be close to the ground, and then the whole vehicle will fall rapidly and cause a huge shock. If in the state of load unloading, the rear wheels of the whole vehicle may completely rise off the ground, and then the rear wheels will hit the ground as the working device falls to the low, causing the jumping phenomenon. Such violent shock and imbalance not only causes great harm to the driver's body, increases the driver's fatigue, and affects the driving comfort, but also seriously threatens the safety of the driver. At the same time, the structure and components of the vehicle are also seriously damaged. The front and rear axles of the vehicle are prone to deformation, fracture, and other damages under frequent impact, and the wear of the articulated shaft is aggravated, which affects the connection stability and reliability. Some existing technical solutions try to solve the imbalance problem by improving the structure of the loader, but often face the problems of great implementation difficulty, insignificant effect, unstable performance, and the like. Simply adjusting the mechanical structure of the working device cannot fundamentally solve the problems of too fast falling speed and impact, and may have a negative impact on other performances of the working device. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a hydraulic control system and method of a loader. The present application applies a balance valve to the hydraulic control system on the basis that the existing structure is not easy to implement or has a high cost, solves the problem of rapid falling of the working device, avoids the whole vehicle shock and jumping caused by violent impact, and avoids the danger and damage caused by the imbalance of the vehicle.

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

[0006] In a first aspect, the present application provides a hydraulic control system of a loader, the loader comprising an oil tank, a steering system, a control system and the 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 connected to the boom cylinder and the bucket cylinder through the reversing valve group.

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

[0008] As a further technical solution, a first balance 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 balance valve, and the other port of the first balance valve is connected to the rodless chamber of the boom cylinder.

[0009] As a further technical solution, a second balance 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 balance valve, and the other port of the second balance valve is connected to the rodless chamber of the bucket cylinder.

[0010] As a further technical solution, a radiator is connected to the oil outlets of the first reversing valve and the second reversing valve; one end of the radiator is 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 further comprises a second hydraulic pump and a third hydraulic pump; an 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 further 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 further connected to the control system.

[0013] The hydraulic control method of the loader based on the hydraulic control system of any one of the first aspect comprises the following steps: when the loader boom is lifted, the hydraulic oil output from the first hydraulic pump outlet enters the first reversing valve through the inlet of the first reversing valve, the first reversing valve is switched to the left working state, the hydraulic oil is output from the first working oil port of the first reversing valve through the first balance valve to enter the rodless chamber of the boom cylinder in a one-way manner, and the rod chamber of the boom cylinder returns oil; when the loader boom falls, the hydraulic oil output from the first hydraulic pump outlet enters the first reversing valve through the inlet of the first reversing valve, the first reversing valve is switched to the right working state, the hydraulic oil is output from the second working oil port of the first reversing valve to enter the rod chamber of the boom cylinder, and the rodless chamber of the boom cylinder returns oil through the first balance valve.

[0014] As a further technical solution, when the loader bucket is scooped, the hydraulic oil output from the first hydraulic pump outlet enters the second reversing valve through the inlet of the second reversing valve, the second reversing valve is switched to the left working state, the hydraulic oil is output from the first working oil port of the second reversing valve through the second balance valve to enter the rodless chamber of the bucket cylinder in a one-way manner, and the rod chamber of the bucket cylinder returns oil; when the loader bucket is unloaded, the hydraulic oil output from the first hydraulic pump outlet enters the second reversing valve through the inlet of the second reversing valve, the second reversing valve is switched to the right working state, the hydraulic oil is output from the second working oil port of the second reversing valve to enter the rod chamber of the bucket cylinder, and the rodless chamber of the bucket cylinder returns oil through the second balance valve.

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

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

[0017] The one or more technical solutions of the present application have the following beneficial effects:

[0018] (1) The balance valve is introduced into the hydraulic control system, when the loader boom falls and the loader bucket is unloaded, the rodless chamber of the boom cylinder and the rodless chamber of the bucket cylinder both return oil after passing through the balance valve, precise control of the unloading speed of the bucket and the falling speed of the boom is realized, the phenomenon of rapid unloading and falling during unloading and falling is effectively prevented, the smooth and safe operation of the working device is ensured, the whole vehicle is not shaken and jumped due to the rapid falling of the bucket and the boom, important components such as the drive axle, the tire, the frame and the hinge are greatly protected from being damaged by the great impact, the damage of other components of the vehicle caused by the impact is effectively reduced, and the service life of the vehicle is prolonged.

[0019] (2) The application makes the vehicle operation and work more stable, effectively avoids the danger that the driver faces due to the severe vibration and imbalance of the vehicle, provides a safer and more comfortable working environment for the driver, and improves the work efficiency. At the same time, the balance of the vehicle is ensured from the hardware of the vehicle, and the driver's proficiency, experience, and driving age are not relied on to ensure that the vehicle does not become unbalanced. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description of the exemplary embodiments of the application, serve to explain the application, and do not constitute an improper limitation on the application.

[0021] Figure 1 The schematic diagram of the loader hydraulic control system of the application;

[0022] Figure 2 The schematic diagram of the loader overall structure of the application;

[0023] Wherein: 1, boom cylinder; 2, bucket cylinder; 3, first balance valve; 4, second balance 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 description is exemplary and is intended to provide further explanation of the application. Unless otherwise indicated, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0025] Example 1

[0026] The present embodiment provides a loader hydraulic control system. The existing loader working device includes an oil tank, a steering system, a control system, and a hydraulic control system, etc. The technical scheme provided by the present embodiment is based on the fact that the existing structure is not easy to realize or is very expensive, and the hydraulic control system is creatively improved, such as Figure 1As shown, the hydraulic control system comprises: a boom cylinder 1, a bucket cylinder 2, a reversing valve group and a pump group, wherein the pump group is connected to the boom cylinder 1 and the bucket cylinder 2 through the reversing valve group, specifically: the pump group comprises a first hydraulic pump 8, a second hydraulic pump 9 and a third hydraulic pump 10, the reversing valve group comprises 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 connected to the oil inlet of the first reversing valve 5 and the second reversing valve 6 respectively, the first working oil port of the first reversing valve 5 is connected to the rodless cavity of the boom cylinder 1, and the rod cavity 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 cavity of the bucket cylinder 2, and the rod cavity 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 unloading speed of the bucket and the falling speed of the boom, prevent the phenomenon of high speed during the unloading of the bucket and the falling of the boom, ensure the smooth and safe operation of the working device, and eliminate the whole vehicle shock and jumping caused by the high speed falling of the bucket and the boom, a balance valve is introduced, specifically: as shown Figure 1 The first working oil port of the first reversing valve 5 is connected to one port of the first balance valve 3, and the other port of the first balance valve 3 is connected to the rodless cavity of the boom cylinder 1. At the same time, the first working oil port of the second reversing valve 6 is connected to the rodless cavity of the bucket cylinder 2 through the second balance valve 4, the first working oil port of the second reversing valve 6 is connected to one port of the second balance valve 4, and the other port of the second balance valve 4 is connected to the rodless cavity of the bucket cylinder 2. In this embodiment, as shown Figure 1 The oil outlets of the first reversing valve 5 and the second reversing valve 6 are jointly connected to a radiator 14, one end of the radiator 14 is connected to the oil outlets of the first reversing valve 5 and the second reversing valve 6 respectively, and the other end of the radiator 14 is connected to an oil tank.

[0027] As shown Figure 1 In this embodiment, the oil outlet of the third hydraulic pump 10 is connected to a first overflow valve 11, and 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 an oil tank. The oil outlet of the second hydraulic pump 9 is also connected to a priority valve 12, and the function of the priority valve is to ensure that the steering oil supply is given priority. 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 a steering system. The oil outlet of the third hydraulic pump 10 is also connected to a control system.

[0028] In this embodiment, as shown 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 to operate the first reversing valve 3 and the second reversing valve 4 to reverse. 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, and the pressure reducing valve is also connected to the bypass of the accumulator 17, and further leads to the foot valve 19 and the two handle 18, and the two handle is connected to the first reversing valve 5 and the second reversing valve 6 to reverse, and pushes the spool to move, and the first reversing valve 5 and the second reversing valve 6 reverse.

[0029] Example two

[0030] The hydraulic control method of the loader mentioned in this embodiment is based on the hydraulic control system of the loader described in example one, and the method comprises:

[0031] When the loader arm is lifted, the first handle 18 is operated, the third hydraulic pump 10 supplies oil to the first handle, the first reversing valve 5 spool is pushed to move to the left through the operation oil way, the reversing valve works in the left 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, the third hydraulic pump 10 switches the first reversing valve to the left working state, and the hydraulic oil is output from the first working oil port of the first reversing valve and enters the rodless chamber of the arm cylinder through the first balance valve in one way, and the rod chamber of the arm cylinder returns oil; When the loader arm falls, the first handle 18 is operated, the third hydraulic pump 10 supplies oil to the first handle, the first reversing valve 5 spool is pushed to move to the right through the operation oil way, 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 the first reversing valve is switched to the right working state, and the hydraulic oil is output from the second working oil port of the first reversing valve and enters the rod chamber of the arm cylinder, and the rodless chamber of the arm cylinder returns oil through the first balance valve.

[0032] When the loader bucket is scooped, the second handle 22 is operated, the third hydraulic pump 10 supplies oil to the second handle, the second directional valve 6 is pushed to move left through the control oil way, the directional valve works in the left position, the hydraulic oil output from the first hydraulic pump output port enters the second directional valve through the oil inlet of the second directional valve, the second directional valve is switched to the left working state, the hydraulic oil is output from the first working oil port of the second directional valve and enters the rodless cavity of the bucket cylinder through the second balance valve in one way, and the rod cavity of the bucket cylinder returns oil; when the loader bucket is unloaded, the second handle 22 is operated, the third hydraulic pump 10 supplies oil to the second handle, the second directional valve 6 is pushed to move right through the control oil way, the directional valve works in the right position, the hydraulic oil output from the first hydraulic pump output port enters the second directional valve through the oil inlet of the second directional valve, the second directional valve is switched to the right working state, the hydraulic oil is output from the second working oil port of the second directional valve and enters the rod cavity of the bucket cylinder, and the rodless cavity of the bucket cylinder returns oil through the second balance valve. The return oil of the boom cylinder and the bucket cylinder flows back to the oil tank after heat dissipation through the radiator.

[0033] The above only describes the preferred embodiments of the present application and is not used to limit the present application. The present application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A loader hydraulic control system, the loader including a tank, a steering system, a control system, and a hydraulic control system, characterized by, The hydraulic control system comprises a boom cylinder, a bucket cylinder, a reversing valve group and a pump group; wherein the pump group is connected with the boom cylinder and the bucket cylinder through the reversing valve group; The pump group comprises a first hydraulic pump, the reversing valve group comprises a first reversing valve and a second reversing valve, the oil outlet of the first hydraulic pump is connected with the oil inlet of the first reversing valve and the second reversing valve respectively, the first working oil port of the first reversing valve is connected with the rodless chamber of the boom cylinder, and the rod chamber of the boom cylinder is connected with the second working oil port of the first reversing valve; the first working oil port of the second reversing valve is connected with the rodless chamber of the bucket cylinder, and the rod chamber of the bucket cylinder is connected with the second working oil port of the second reversing valve; The pump group further comprises a second hydraulic pump and a third hydraulic pump; The first working oil port of the first reversing valve is connected with the first balancing valve between the rodless chamber of the boom cylinder; The first working oil port of the second reversing valve is connected with the second balancing valve between the rodless chamber of the bucket cylinder; The oil outlet of the second hydraulic pump is further connected with a priority valve, one end of the priority valve is connected with the oil outlet of the second hydraulic pump, and the other end of the priority valve is connected with a steering system; the oil outlet of the third hydraulic pump is further connected with a control system.

2. A hydraulic control system for a loader as set forth in claim 1, wherein, The first working oil port of the first reversing valve is connected with one port of the first balancing valve, and the other port of the first balancing valve is connected with the rodless chamber of the boom cylinder.

3. A hydraulic control system for a loader as set forth in claim 1, wherein, The first working oil port of the second reversing valve is connected with one port of the second balancing valve, and the other port of the second balancing valve is connected with the rodless chamber of the bucket cylinder.

4. A hydraulic control system for a loader as set forth in claim 1, wherein, The oil outlets of the first reversing valve and the second reversing valve are jointly connected with a radiator, one end of the radiator is connected with the oil outlets of the first reversing valve and the second reversing valve respectively, and the other end of the radiator is connected with an oil tank.

5. A hydraulic control system for a loader as set forth in claim 1, wherein, The oil outlet of the third hydraulic pump is connected with a first overflow valve, one end of the first overflow valve is connected with the oil outlet of the third hydraulic pump, and the other end of the first overflow valve is connected with the oil tank.

6. A method of hydraulic control of a loader based on a hydraulic control system of any one of claims 1-5, characterized by The method comprises the following steps: When the boom of the loader 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, the first reversing valve is switched to the left working state, the hydraulic oil is output from the first working oil port of the first reversing valve and enters the rodless chamber of the boom cylinder through the first balancing valve in one direction, and the rod chamber of the boom cylinder returns oil; when the boom of the loader falls, 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 first reversing valve is switched to the right working state, the hydraulic oil is output from 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.

7. A method of hydraulic control of a loader as set forth in claim 6, wherein When the loader bucket is scooped, the hydraulic oil output by the first hydraulic pump outlet enters the second reversing valve through the inlet of the second reversing valve, the second reversing valve is switched to the left working state, the hydraulic oil is output through the first working oil port of the second reversing valve and enters the rodless cavity of the bucket cylinder through the second balance valve in one direction, and the rod cavity of the bucket cylinder returns oil; when the loader bucket is unloaded, the hydraulic oil output by the first hydraulic pump outlet enters the second reversing valve through the inlet of the second reversing valve, the second reversing valve is switched to the right working state, the hydraulic oil is output through the second working oil port of the second reversing valve and enters the rod cavity of the bucket cylinder, and the rodless cavity of the bucket cylinder returns oil through the second balance valve.

8. A method of hydraulic control of a loader as set forth in claim 6, wherein, The oil return of the boom cylinder flows back to the oil tank after heat dissipation through the radiator.

9. A method of hydraulic control of a loader as set forth in claim 7, wherein, The oil return of the bucket cylinder flows back to the oil tank after heat dissipation through the radiator. The oil return of the bucket cylinder flows back to the oil tank after heat dissipation through the radiator.

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