Multi-point lifting chassis hydraulic automatic control system and working method

Abstract

The present invention discloses a hydraulic automatic regulation system and working method for a multi-point lifting chassis, belonging to the field of agricultural machinery, which includes a multi-point lifting device, a hydraulic system and an automatic leveling control system; the multi-point lifting device includes an upper chassis frame and a symmetrical lifting mechanism, and the lifting mechanism includes a running system, a front lifting mechanism, a rear lifting mechanism, a front hydraulic cylinder and a rear hydraulic cylinder; the hydraulic system includes an oil pump, a three-position four-way valve, a speed regulating valve, a hydraulic control one-way valve and an equal-displacement synchronous two-way hydraulic motor; the automatic leveling control system includes a two-axis inclination sensor, a control panel and a controller. The present invention can enable the crawler combine harvester to adjust the telescopic amount required for each hydraulic cylinder and automatically control the multi-point lifting adjustment mechanism of the chassis by detecting the inclination attitude of the chassis according to the road conditions during the harvesting operation, so as to achieve the leveling of the vehicle body, which can effectively improve the reliability of the vehicle during operation and driving, reduce the operation difficulty of the driver, and help to further improve the harvesting operation efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural machinery, and particularly relates to a hydraulic automatic control system for a multi-point lifting chassis. Background Art

[0002] The crawler chassis has prominent advantages such as large grounding area, small grounding pressure, small turning radius, and flexible turning. Therefore, it has been widely used in paddy field operations in southern China. The chassis of traditional crawler combine harvesters adopts a welded integral structure, and the upper frame of the chassis is fixed to the running gear through structures such as eight-shaped beams, resulting in the inability to adjust the body posture. The agricultural operation environment is mostly rough roads, and it is easy to encounter obstacles such as ridges and sinkholes during travel. Therefore, it is difficult for the vehicle body and the operation platform to maintain a horizontal state during vehicle travel, increasing the operation difficulty of the operator; even prone to rollover accidents, seriously affecting the driving reliability and operation efficiency of the vehicle.

[0003] An automatically balanced four-wheel vehicle chassis proposed in Chinese Patent CN110178468A realizes the control of the side frame and the balance of the vehicle body by adjusting the extension arm, but it is only applicable to the leveling when the vehicle body is tilted on both sides and cannot realize the adjustment of the vehicle body tilt front and back. An automatic balance system for a self-propelled harvesting machine chassis proposed in Chinese Patent CN110001801A uses sensors to obtain the tilt information between the vehicle body and the ground, and automatically levels the vehicle body through a balance hydraulic system. However, its balance hydraulic system is only applicable to the adjustment mechanism of wheeled operation vehicles, and the existing technology is difficult to meet the operation requirements of crawler-type agricultural machinery to realize automatic control of the vehicle body and maintain a horizontal state in the field with complex road conditions. Summary of the Invention

[0004] The purpose of the invention is to provide a hydraulic automatic control system for a multi-point lifting chassis, so as to realize that when the crawler combine harvester travels on rough roads or encounters travel obstacles, the vehicle body can be automatically controlled through the hydraulic system to maintain a horizontal state, improve the driving safety and reliability of the vehicle, and improve the field operation efficiency.

[0005] The invention realizes the above purpose through the following technical solutions:

[0006] The hydraulic automatic control system for a multi-point lifting chassis includes a multi-point lifting device, a hydraulic system, and an automatic leveling control system;

[0007] The multi-point lifting device includes symmetrically arranged lifting mechanisms. Each lifting mechanism includes a traveling system, a lifting mechanism, a rear lifting mechanism, a connecting rod, a front hydraulic cylinder, and a rear hydraulic cylinder. The traveling system is provided with several wheels. The lifting mechanism and the rear lifting mechanism are hinged to the traveling system. The lifting mechanism includes a front lower swing arm, a front spline shaft, and a front upper swing arm. One end of the front lower swing arm is hinged to the traveling system, and the other end is installed on the front spline shaft. The front upper swing arm is also installed on the front spline shaft, so as to realize the synchronous movement of the front lower swing arm and the front upper swing arm. The front upper swing arm is hinged to the hydraulic rod of the left front hydraulic cylinder. The ear end of the left front hydraulic cylinder is fixedly connected to one end of the connecting rod. The other end of the connecting rod is hinged to the rear upper swing arm. Both ends of the rear upper swing arm are respectively connected to the rear spline shaft and the hydraulic rod of the left rear hydraulic cylinder. Among them, the ear end of the left rear hydraulic cylinder is fixedly connected to the traveling system bracket, and the rear lower swing arm is also arranged on the rear spline shaft, so as to realize the synchronous movement of the rear lower swing arm and the rear upper swing arm. The rear lower swing arm is hinged to the upper frame of the chassis.

[0008] The hydraulic system includes an oil tank, an oil pump, a check valve, a relief valve, a solenoid valve, a three-position four-way valve, a throttle valve, a pilot-operated check valve, and an equal-displacement synchronous bidirectional hydraulic motor. The relief valve is connected to the oil pump to play a protective role, and the solenoid valve acts as a main switch. A check valve is provided before the solenoid valve is connected to the oil pump. The oil pump is connected in parallel with a first three-position four-way valve, a second three-position four-way valve, a third three-position four-way valve, and a fourth three-position four-way valve. The first three-position four-way valve is connected to the left front hydraulic cylinder and the right front hydraulic cylinder. The second three-position four-way valve is connected to the left rear hydraulic cylinder. The fourth three-position four-way valve is connected to the right rear hydraulic cylinder. The third three-position four-way valve connects the left rear hydraulic cylinder and the right rear hydraulic cylinder.

[0009] The automatic leveling control system includes a biaxial inclination sensor, a control panel, and a controller. The biaxial inclination sensor is installed on the cross beam of the upper frame of the chassis. The biaxial inclination sensor is connected to the input end of the controller, and the output end of the controller is connected to the control panel. The control panel is arranged in the cab of the combine harvester and can display the inclination attitude of the chassis.

[0010] Further, a limiting mechanism is fixed on the beam of the traveling system, and the limiting mechanism is arranged directly below the front lower swing arm.

[0011] Further, the front hydraulic cylinder includes a left front hydraulic cylinder and a right front hydraulic cylinder; the rear hydraulic cylinder includes a left rear hydraulic cylinder and a right rear hydraulic cylinder.

[0012] Further, the multi-point lifting device further includes an upper frame of the chassis. Two sets of drive wheel brackets and supporting wheels are installed on the upper frame of the chassis. The ear ends of the rear hydraulic cylinders, the front spline shafts, and the rear spline shafts are respectively hinged to the upper frame of the chassis.

[0013] Further, in the hydraulic system, the first three-position four-way valve is connected to the rod chambers of the left front hydraulic cylinder and the right front hydraulic cylinder through a first hydraulic control check valve, a speed control valve, and a first group of equal-displacement synchronous bidirectional hydraulic motors. The other control oil circuit of the first hydraulic control check valve is connected to the rodless chambers of the left front hydraulic cylinder and the right front hydraulic cylinder; the third three-position four-way valve is connected to the rod chambers of the left rear hydraulic cylinder and the right rear hydraulic cylinder through a second hydraulic control check valve, a speed control valve, and a second group of equal-displacement synchronous bidirectional hydraulic motors. The other control oil circuit of the second hydraulic control check valve is connected to the rodless chambers of the left rear hydraulic cylinder and the right rear hydraulic cylinder.

[0014] Further, in the hydraulic system, a check valve is respectively provided before the three-position four-way valve is connected in parallel with the oil pump, and an overflow valve is respectively provided at the oil inlets of the first three-position four-way valve and the third three-position four-way valve.

[0015] Further, in the hydraulic system, the oil outlets of the second three-position four-way valve and the fourth three-position four-way valve are respectively connected to a hydraulic self-locking group composed of a check valve and a speed control valve.

[0016] A working method of a multi-point lifting chassis hydraulic automatic control system includes four leveling modes when the chassis tilts forward, tilts backward, tilts left, and tilts right. During the working process of the combine harvester, the automatic leveling control system detects the chassis tilt angle and attitude, determines the hydraulic cylinders that need to be adjusted for leveling, calculates the required telescopic adjustment amount, realizes the leveling of the chassis by controlling the hydraulic system, and records each adjustment amount in real time; specifically includes the following steps:

[0017] S1: When the automatic leveling control system detects that the chassis tilts left, if the right rear hydraulic cylinder is in the initial position, it is necessary to extend the left rear hydraulic cylinder to lift the left side of the chassis frame to achieve leveling. At this time, the control system controls the right end of the solenoid valve to be energized, and the left end of the second three-position four-way valve to be energized, and the hydraulic oil enters the rodless chamber of the left rear hydraulic cylinder to make it extend; if the left rear hydraulic cylinder is in the initial position, it is necessary to contract the right rear hydraulic cylinder to lower the right side of the chassis frame to achieve leveling. At this time, the control system controls the left end of the fourth three-position four-way valve to be energized, and the hydraulic oil enters the rod chamber of the right rear hydraulic cylinder to make it contract;

[0018] S2: When the automatic leveling control system detects that the chassis tilts right, if the right rear hydraulic cylinder is in the initial position, it is necessary to contract the left rear hydraulic cylinder to lower the left side of the chassis frame to achieve leveling; at this time, the control system controls the right end of the solenoid valve to be energized, and the right end of the second three-position four-way valve to be energized, and the hydraulic oil enters the rod chamber of the left rear hydraulic cylinder to make it contract; if the left rear hydraulic cylinder is in the initial position, it is necessary to extend the right rear hydraulic cylinder to lift the right side of the chassis frame to achieve leveling. At this time, the control system controls the right end of the fourth three-position four-way valve to be energized, and the hydraulic oil enters the rodless chamber of the right rear hydraulic cylinder to make it extend;

[0019] S3: When the automatic leveling control system detects that the chassis is tilted forward or backward, the control system needs to calculate and simultaneously adjust the front hydraulic cylinders and the rear hydraulic cylinders to achieve leveling, and ensure that the telescopic amounts of the left front hydraulic cylinder and the right front hydraulic cylinder are the same, and the telescopic amounts of the left rear hydraulic cylinder and the right rear hydraulic cylinder are the same;

[0020] When the front hydraulic cylinders contract simultaneously, the left end of the first three-way four-way valve is energized, and the hydraulic oil output by the hydraulic pump enters the rod chambers of the front hydraulic cylinders through the first group of equal-displacement bidirectional synchronous hydraulic motors to make them contract synchronously; when the front hydraulic cylinders extend simultaneously, the right end of the first three-way four-way valve is energized, and the hydraulic oil enters the rodless chambers of the front hydraulic cylinders. The output hydraulic oil passes through the first group of equal-displacement synchronous bidirectional hydraulic motors to achieve synchronous extension and returns to the fuel tank through the pilot-operated check valve;

[0021] When the rear hydraulic cylinders contract simultaneously, the left end of the third three-way four-way valve is energized, and the hydraulic oil output by the hydraulic pump enters the rod chambers of the rear hydraulic cylinders through the second group of equal-displacement bidirectional synchronous hydraulic motors to make them contract synchronously; when the rear hydraulic cylinders extend simultaneously, the right end of the third three-way four-way valve is energized, and the hydraulic oil enters the rodless chambers of the front hydraulic cylinders. The output hydraulic oil passes through the second group of equal-displacement synchronous bidirectional hydraulic motors to achieve synchronous extension and returns to the fuel tank through the pilot-operated check valve.

[0022] Advantages of the present invention:

[0023] (1) Adopting a split structure, connecting the upper frame of the chassis and the two-side traveling systems through a multi-point lifting mechanism, enabling the chassis to adjust the attitude of the chassis according to different road surface environments and operation requirements to achieve the leveling of the chassis and the operation platform, improving the driving reliability and reducing the operation difficulty for the operator;

[0024] (2) The present invention can, according to the operation requirements, adjust the telescopic amounts of each hydraulic cylinder through the hydraulic system to achieve the leveling operation of the chassis. The designed hydraulic system has a reasonable structure layout and a self-locking function, which can ensure the reliability of the operation;

[0025] (3) The present invention uses a double-axis inclination sensor to detect the chassis attitude in real time and adjusts the chassis level in real time through the controller. Its control method is simple and the operation is convenient. Compared with manual adjustment, it is more accurate and efficient, and the adjustment method is flexible and mobile, greatly reducing the labor intensity of the driver. Description of the Drawings

[0026] Figure 1 is the overall schematic diagram of the multi-point liftable and adjustable crawler combine harvester;

[0027] Figure 2 is the overall schematic diagram of the multi-point lifting device;

[0028] Figure 3 is the schematic diagram of the multi-point lifting mechanism;

[0029] Figure 4 is the schematic diagram of the hydraulic system;

[0030] Figure 5 is the working flow chart of the multi-point lifting chassis hydraulic automatic control system;

[0031] Figure 6(a) is the right tilt leveling diagram (removing the crawler);

[0032] Figure 6(b) is the rear tilt leveling diagram (removing the crawler).

[0033] Reference numerals:

[0034] 1. Running gear; 2. Front lifting mechanism; 2-1. Front upper swing arm; 2-2. Front spline shaft; 2-3. Front lower swing arm; 2-4. Front connecting swing arm; 3. Rear lifting mechanism; 3-1. Rear upper swing arm; 3-2. Rear spline shaft; 3-3. Rear lower swing arm; 4. Link; 5. Limit mechanism; 6. Front hydraulic cylinder; 6-1. Left front hydraulic cylinder; 6-2. Right front hydraulic cylinder; 7. Rear hydraulic cylinder; 7-1. Left rear hydraulic cylinder; 7-2. Right rear hydraulic cylinder; 8. Upper chassis frame; 8-1. Driving wheel bracket; 8-2. Idler wheel; 9. Fuel tank; 10. Hydraulic pump; 11. Check valve; 12. Relief valve; 13. Solenoid valve; 14. Three-position four-way valve; 14-1. First three-position four-way valve; 14-2 Second three-position four-way valve; 14-3. Third three-position four-way valve; 14-4. Fourth three-position four-way valve; 15. Flow control valve; 15-1. First flow control valve; 15-2. Second flow control valve; 16. Hydraulically controlled check valve; 16-1. First hydraulically controlled check valve; 16-2. Second hydraulically controlled check valve; 17. Equal-displacement synchronous bidirectional hydraulic motor; 17-1. First group of equal-displacement synchronous bidirectional hydraulic motors; 17-2. Second group of equal-displacement synchronous bidirectional hydraulic motors; 18. Hydraulic self-locking group; 19. Control panel; 20. Biaxial inclination sensor. Detailed implementation manners

[0035] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0036] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] First, the following specifically describes, in conjunction with the accompanying drawings, the

[0039] Combined with the attached Figure 1 、 2, Figures 6(a) and 6(b), the multi-point lifting device includes two sets of symmetric lifting mechanisms. Each set of lifting mechanisms includes a traveling system 1, a front lifting mechanism 2, a rear lifting mechanism 3, a connecting rod 4, a limiting mechanism 5, a front hydraulic cylinder 6, a rear hydraulic cylinder 7, and a chassis upper frame 8. The front lifting mechanism 2 includes a front upper swing arm 2-1, a front spline shaft 2-2, a front lower swing arm 2-3, and a front connecting swing arm 2-4. The rear lifting mechanism 3 includes a rear upper swing arm 3-1, a rear spline shaft 3-2, and a rear lower swing arm 3-3. The front connecting swing arm 2-4 is hinged to the front lower swing arm 2-3, and the front lower swing arm 2-3 is fixedly connected to the front upper swing arm 2-1 through the front spline shaft 2-2. The rear upper swing arm 3-1 is fixedly connected to the rear lower swing arm 3-3 through the rear spline shaft 3-2. The other end of the front lower swing arm 3-3 is hinged to the traveling system 1, and the front lifting mechanism 2 and the rear lifting mechanism 3 are connected by the front hydraulic cylinder 6 and the connecting rod 4. The rear lower swing arm 3-3 is connected to the traveling system 1, and the rear upper swing arm 3-1 is hinged to the rear hydraulic cylinder 7. The limiting mechanism 5 is fixed on the beam of the traveling system 1 and is arranged below the front lower swing arm 2-3 when it is in the horizontal position. Two sets of drive wheel brackets 8-1 and idler wheels 8-2 are installed on the chassis upper frame 8. The earring end of the rear hydraulic cylinder 7, the front spline shaft 2-2, and the rear spline shaft 3-2 are respectively hinged to the chassis upper frame 9.

[0040] Combined with the attached Figure 3 As shown, the automatic leveling control system includes a biaxial inclination sensor 20, a control panel 19, and a controller. The biaxial inclination sensor 20 is installed on the cross beam of the chassis upper frame 8. The biaxial inclination sensor 20 is connected to the input end of the controller, and the output end of the controller is connected to the control panel 19. The control panel 19 is arranged in the cab of the combine harvester and can display the inclination attitude of the chassis.

[0041] Combined with the attached Figure 4 As shown, the hydraulic system includes an oil tank 9, an oil pump 10, a check valve 11, a relief valve 12, a solenoid valve 13, a three-position four-way valve 14, a throttle valve 15, a pilot-operated check valve 16, an equal-displacement synchronous two-way hydraulic motor 17, and the front hydraulic cylinder 6 and the rear hydraulic cylinder 7. The relief valve 12 is connected to the oil pump 10 to play a protective role. The solenoid valve 13 plays a main switch role, and a check valve 11 is provided before it is connected to the oil pump 10. The oil pump 10 is connected in parallel with a first three-position four-way valve 14-1, a second three-position four-way valve 14-2, a third three-position four-way valve 14-3, and a fourth three-position four-way valve 14-4. The first three-position four-way valve 14-1 is connected to two front hydraulic cylinders 6. The second three-position four-way valve 14-2 is connected to the left rear hydraulic cylinder 7-1. The fourth three-position four-way valve 14-4 is connected to the left rear hydraulic cylinder 7-2. The third three-position four-way valve 14-3 is connected to the left rear hydraulic cylinder 7-1 and the right rear hydraulic cylinder 7-2.

[0042] The first three-position four-way valve 14-1 is connected to the rod chambers of the two front hydraulic cylinders 6 through the first pilot-operated check valve 16-1, the speed control valve 15, and the first group of equal-displacement synchronous bidirectional hydraulic motors 17-1. The other control oil circuit of the first pilot-operated check valve 16-1 is connected to the rodless chambers of the two front hydraulic cylinders 6; the third three-position four-way valve 14-3 is connected to the rod chambers of the two rear hydraulic cylinders 7 through the second pilot-operated check valve 16-2, the speed control valve 15, and the second group of equal-displacement synchronous bidirectional hydraulic motors 17-2. The other control oil circuit of the second pilot-operated check valve 16-2 is connected to the rodless chambers of the two rear hydraulic cylinders 7.

[0043] Before the three-position four-way valve 14 is connected in parallel with the oil pump 10 described above, one check valve 11 is respectively provided, and there is another relief valve 12 at the oil inlets of the first three-position four-way valve 14-1 and the third three-position four-way valve 14-3; the oil outlets of the second three-position four-way valve 14-2 and the fourth three-position four-way valve 14-4 are respectively connected to a hydraulic self-locking group 18 composed of a check valve 11 and a speed control valve 15.

[0044] Combined with the attached Figure 5 , a working method of a multi-point lifting chassis hydraulic automatic control system, including four leveling modes when the chassis tilts forward, tilts backward, tilts left, and tilts right. During the working process of the combine harvester, the chassis inclination angle and attitude are detected by the automatic leveling control system, the hydraulic cylinders that need to be adjusted for leveling are determined, the required telescopic adjustment amount is calculated, and the leveling of the chassis is achieved by controlling the hydraulic system, and each adjustment amount is recorded in real time; specifically, it includes the following steps:

[0045] S1: When the automatic leveling control system detects that the chassis tilts left, if the right rear hydraulic cylinder 7-2 is in the initial position, the left rear hydraulic cylinder 7-1 needs to be extended to lift the left side of the chassis frame to achieve leveling. At this time, the control system controls the right end of the solenoid valve 13 to be energized, and the left end of the second three-position four-way valve 14-2 to be energized, and the hydraulic oil enters the rodless chamber of the left rear hydraulic cylinder 7-1 to make it extend; if the left rear hydraulic cylinder 7-1 is in the initial position, the right rear hydraulic cylinder 7-2 needs to be contracted to lower the right side of the chassis frame to achieve leveling. At this time, the control system controls the left end of the fourth three-position four-way valve 14-4 to be energized, and the hydraulic oil enters the rod chamber of the right rear hydraulic cylinder 7-2 to make it contract;

[0046] S2: When the automatic leveling control system detects that the chassis tilts right, if the right rear hydraulic cylinder 7-2 is in the initial position, the left rear hydraulic cylinder 7-1 needs to be contracted to lower the left side of the chassis frame to achieve leveling; at this time, the control system controls the right end of the solenoid valve 13 to be energized, and the right end of the second three-position four-way valve 14-2 to be energized, and the hydraulic oil enters the rod chamber of the left rear hydraulic cylinder 7-1 to make it contract; if the left rear hydraulic cylinder 7-1 is in the initial position, the right rear hydraulic cylinder 7-2 needs to be extended to lift the right side of the chassis frame to achieve leveling. At this time, the control system controls the right end of the fourth three-position four-way valve 14-4 to be energized, and the hydraulic oil enters the rodless chamber of the right rear hydraulic cylinder 7-2 to make it extend;

[0047] S3: When the automatic leveling control system detects that the chassis tilts forward or backward, the control system needs to calculate and simultaneously adjust the front hydraulic cylinders 6 and the rear hydraulic cylinders 7 to achieve leveling, and ensure that the telescopic amounts of the left front hydraulic cylinder 6-1 and the right front hydraulic cylinder 6-2 are the same, and the telescopic amounts of the left rear hydraulic cylinder 7-1 and the right rear hydraulic cylinder 7-2 are the same;

[0048] When the front hydraulic cylinders 6 contract simultaneously, the left end of the first three-position four-way valve 14-1 is energized, and the hydraulic oil output by the hydraulic pump enters the rod chambers of the front hydraulic cylinders 6 through the first group of equal-displacement bidirectional synchronous hydraulic motors 17-1 to make them contract synchronously; when the front hydraulic cylinders 6 extend simultaneously, the right end of the first three-position four-way valve 14-1 is energized, and the hydraulic oil enters the rodless chambers of the front hydraulic cylinders 6. The output hydraulic oil passes through the first group of equal-displacement synchronous bidirectional hydraulic motors 6 to achieve synchronous extension and returns to the fuel tank through the pilot-operated check valve;

[0049] When the rear hydraulic cylinders 7 contract simultaneously, the left end of the third three-position four-way valve 14-3 is energized, and the hydraulic oil output by the hydraulic pump enters the rod chambers of the rear hydraulic cylinders 7 through the second group of equal-displacement bidirectional synchronous hydraulic motors 17-2 to make them contract synchronously; when the rear hydraulic cylinders 7 extend simultaneously, the right end of the third three-position four-way valve 14-3 is energized, and the hydraulic oil enters the rodless chambers of the front hydraulic cylinders. The output hydraulic oil passes through the second group of equal-displacement synchronous bidirectional hydraulic motors 17-2 to achieve synchronous extension and returns to the fuel tank through the pilot-operated check valve.

[0050] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. The hydraulic automatic control system for a multi-point lifting chassis, characterized in that, It includes a multi-point lifting device, a hydraulic system and an automatic leveling control system; The multi-point lifting device includes symmetrically arranged lifting mechanisms, and each lifting mechanism includes a running system, a lifting mechanism, a rear lifting mechanism, a connecting rod, a front hydraulic cylinder and a rear hydraulic cylinder; The running system (1) is hinged with a lifting mechanism and a rear lifting mechanism. The lifting mechanism includes a front lower swing arm (2-3), a front spline shaft (2-2) and a front upper swing arm (2-1); one end of the front lower swing arm (2-3) is hinged to the running system, and the other end is installed on the front spline shaft (2-2). The front upper swing arm (2-1) is also installed on the front spline shaft (2-2), so as to realize the synchronous movement of the front lower swing arm (2-3) and the front upper swing arm (2-1). The front upper swing arm (2-1) is hinged to the hydraulic rod of the left front hydraulic cylinder (6-1). The ear end of the left front hydraulic cylinder (6-1) is fixedly connected to one end of the connecting rod. The other end of the connecting rod is hinged to the rear upper swing arm (3-1). The two ends of the rear upper swing arm (3-1) are respectively connected to the rear spline shaft (3-2) and the hydraulic rod of the left rear hydraulic cylinder (7-1). Among them, the ear end of the left rear hydraulic cylinder (7-1) is fixedly connected to the running system bracket, and the rear lower swing arm (3-3) is also arranged on the rear spline shaft (3-2), so as to realize the synchronous movement of the rear lower swing arm (3-3) and the rear upper swing arm (3-1). The rear lower swing arm (3-3) is hinged to the upper frame of the chassis; The hydraulic system includes an oil tank, an oil pump (10), a check valve (11), a relief valve (12), a solenoid valve (13), a three-position four-way valve (14), a throttle valve (15), a pilot-operated check valve (16) and an equal-displacement synchronous two-way hydraulic motor (17); The relief valve (12) is connected to the oil pump (10) to play a protective role, and the solenoid valve (13) plays a main switch role. The solenoid valve (13) is provided with a check valve (11) before being connected to the oil pump (10); the oil pump (10) is connected in parallel with a first three-position four-way valve (14-1), a second three-position four-way valve (14-2), a third three-position four-way valve (14-3) and a fourth three-position four-way valve (14-4). The first three-position four-way valve (14-1) is connected to the left front hydraulic cylinder (6-1) and the right front hydraulic cylinder (6-2). The second three-position four-way valve (14-2) is connected to the left rear hydraulic cylinder (7-1). The fourth three-position four-way valve (14-4) is connected to the right rear hydraulic cylinder (7-2). The third three-position four-way valve (14-3) is connected to the left rear hydraulic cylinder (7-1) and the right rear hydraulic cylinder (7-2); The automatic leveling control system includes a two-axis inclination sensor (20), a control panel (19) and a controller; the two-axis inclination sensor (20) is installed on the cross beam of the upper frame of the chassis. The two-axis inclination sensor (20) is connected to the input end of the controller, and the output end of the controller is connected to the control panel (19). The control panel (19) is arranged in the cab of the combine harvester and can display the inclination attitude of the chassis; It also includes a limit mechanism fixed on the beam of the running system, and the limit mechanism is arranged directly below the front lower swing arm (2-3); In the hydraulic system, the first three-position four-way valve (14-1) is connected to the rod chambers of the left front hydraulic cylinder (6-1) and the right front hydraulic cylinder (6-2) through the first pilot-operated check valve (16-1), the speed control valve (15), and the first group of equal-displacement synchronous bidirectional hydraulic motors (17-1). The other control oil circuit of the first pilot-operated check valve (16-1) is connected to the rodless chambers of the left front hydraulic cylinder (6-1) and the right front hydraulic cylinder (6-2); the third three-position four-way valve (14-3) is connected to the rod chambers of the left rear hydraulic cylinder (7-1) and the right rear hydraulic cylinder (7-2) through the second pilot-operated check valve (16-2), the speed control valve (15), and the second group of equal-displacement synchronous bidirectional hydraulic motors (17-2). The other control oil circuit of the second pilot-operated check valve (16-2) is connected to the rodless chambers of the left rear hydraulic cylinder (7-1) and the right rear hydraulic cylinder (7-2). In the hydraulic system, before the three-position four-way valve (14) is connected in parallel with the oil pump (10), a check valve (11) is provided respectively, and an overflow valve (12) is provided at the inlet of the first three-position four-way valve (14-1) and the third three-position four-way valve (14-3). In the hydraulic system, the outlets of the second three-position four-way valve (14-2) and the fourth three-position four-way valve (14-4) are respectively connected to a hydraulic self-locking group (18) composed of a check valve (11) and a speed control valve (15). Its working method includes four leveling modes when the chassis tilts forward, tilts backward, tilts left, and tilts right. During the working process of the combine harvester, the automatic leveling control system detects the chassis inclination angle and attitude, determines the hydraulic cylinders that need to be adjusted for leveling, calculates the required telescopic adjustment amount, realizes the leveling of the chassis by controlling the hydraulic system, and records the adjustment amount each time in real time. Specifically, it includes the following steps: S1: When the automatic leveling control system detects that the chassis tilts left, if the right rear hydraulic cylinder (7-2) is in the initial position, it is necessary to extend the left rear hydraulic cylinder (7-1) to lift the left side of the chassis frame to achieve leveling. At this time, the control system controls the right end of the solenoid valve (13) to be energized, and the left end of the second three-position four-way valve (14-2) to be energized, and the hydraulic oil enters the rodless chamber of the left rear hydraulic cylinder (7-1) to make it extend; if the left rear hydraulic cylinder (7-1) is in the initial position, it is necessary to contract the right rear hydraulic cylinder (7-2) to lower the right side of the chassis frame to achieve leveling. At this time, the control system controls the left end of the fourth three-position four-way valve (14-4) to be energized, and the hydraulic oil enters the rod chamber of the right rear hydraulic cylinder (7-2) to make it contract. S2: When the automatic leveling control system detects that the chassis is tilted to the right, if the right rear hydraulic cylinder (7-2) is in the initial position, it is necessary to contract the left rear hydraulic cylinder (7-1) to lower the left side of the chassis frame to achieve leveling. At this time, the control system controls the right end of the solenoid valve (13) to be energized, and the right end of the second three-position four-way valve (14-2) to be energized, so that the hydraulic oil enters the rod chamber of the left rear hydraulic cylinder (7-1) to contract it. If the left rear hydraulic cylinder (7-1) is in the initial position, it is necessary to extend the right rear hydraulic cylinder (7-2) to lift the right side of the chassis frame to achieve leveling. At this time, the control system controls the right end of the fourth three-position four-way valve (14-4) to be energized, and the hydraulic oil enters the rodless chamber of the right rear hydraulic cylinder (7-2) to extend it. S3: When the automatic leveling control system detects that the chassis is tilted forward or backward, the control system needs to calculate and simultaneously adjust the front hydraulic cylinders and the rear hydraulic cylinders to achieve leveling, and ensure that the telescopic amounts of the left front hydraulic cylinder (6-1) and the right front hydraulic cylinder (6-2) are the same, and the telescopic amounts of the left rear hydraulic cylinder (7-1) and the right rear hydraulic cylinder (7-2) are the same. When the front hydraulic cylinders contract simultaneously, the left end of the first three-position four-way valve (14-1) is energized, and the hydraulic oil output by the hydraulic pump enters the rod chambers of the front hydraulic cylinders through the first group of equal-displacement synchronous bidirectional hydraulic motors (17-1) to contract them synchronously. When the front hydraulic cylinders extend simultaneously, the right end of the first three-position four-way valve (14-1) is energized, and the hydraulic oil enters the rodless chambers of the front hydraulic cylinders. The hydraulic oil output by it passes through the first group of equal-displacement synchronous bidirectional hydraulic motors to achieve synchronous extension, and returns to the fuel tank through the hydraulic control check valve. When the rear hydraulic cylinders contract simultaneously, the left end of the third three-position four-way valve (14-3) is energized, and the hydraulic oil output by the hydraulic pump enters the rod chambers of the rear hydraulic cylinders through the second group of equal-displacement synchronous bidirectional hydraulic motors (17-2) to contract them synchronously. When the rear hydraulic cylinders extend simultaneously, the right end of the third three-position four-way valve (14-3) is energized, and the hydraulic oil enters the rodless chambers of the front hydraulic cylinders. The hydraulic oil output by it passes through the second group of equal-displacement synchronous bidirectional hydraulic motors (17-2) to achieve synchronous extension, and returns to the fuel tank through the hydraulic control check valve.

2. The multi-point lifting chassis hydraulic automatic control system according to claim 1, characterized in that The front hydraulic cylinders include a left front hydraulic cylinder (6-1) and a right front hydraulic cylinder (6-2); the rear hydraulic cylinders include a left rear hydraulic cylinder (7-1) and a right rear hydraulic cylinder (7-2).

3. The hydraulic automatic regulation system for a multi-point lifting chassis according to claim 1, characterized in that, The multi-point lifting device further includes an upper chassis frame, and two sets of drive wheel brackets (8-1) and supporting wheels (8-2) are installed on the upper chassis frame; the ear ends of the rear hydraulic cylinders, the front spline shaft (2-2) and the rear spline shaft (3-2) are respectively hinged to the upper chassis frame.

Images