An adjustable rear-mounted power drive harrow

Abstract

The application belongs to the technical field of agricultural scarifier, and particularly relates to an adjustable rear-mounted power-driven rake which comprises a passive depth adjustment mechanism, a composite ball hinge transmission mechanism, a soil loosening mechanism, a metal shell and a roller assembly. The metal shell is composed of a square part and a cylindrical part, the metal shell is connected with a vehicle frame through the composite ball hinge transmission mechanism, and the soil loosening mechanism is arranged in the metal shell. The passive depth adjustment mechanism is creatively provided. The swing of the swing arm body is controlled through the extension and retraction of a hydraulic push rod, so that the relative height of the metal shell and the roller assembly is adjusted, and the working depth is automatically adjusted. In a small amount of special working conditions, the manual adjustment function is still retained.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural soil loosening equipment, and in particular relates to an adjustable rear-mounted power-driven harrow. Background Art

[0002] A power harrow is a soil loosening device typically installed behind a tractor or other agricultural machinery. It has two power sources: one is from the machinery, transmitted via a drive shaft; the other is from the harrow itself, often driven by an electric motor and a reducer. While power harrows are widely used in agricultural production, they still face some challenges:

[0003] First: Unpowered harrows do not have a complex transmission structure, so they are often connected with trailer structures such as ball joints. This way, the harrow does not need to be raised when the front vehicle turns or makes a U-turn, which has higher flexibility and work efficiency. However, powered harrows generally cannot swing horizontally relative to the vehicle body.

[0004] Second: Under different working conditions, the working depth requirements may be different, and the traditional adjustment method is relatively complicated. Taking manual adjustment as an example, each adjustment requires stopping the vehicle, getting off, and then getting back on and starting the vehicle after the adjustment is completed, which greatly affects work efficiency. Electric adjustment not only requires an additional complete set of control systems, but is also highly dependent on the vehicle's own electrification level. Summary of the Invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides an adjustable rear-mounted power-driven rake. Under most normal working conditions, if the working depth is deep, the vehicle will move slower, and if the working depth is shallow, the vehicle will move faster. This is mainly to avoid damage to the teeth caused by excessive lateral impact; based on the negative correlation between the working depth and the travel speed, the present invention creatively proposes a passive depth adjustment mechanism; the swing of the swing arm body is controlled by the telescopic control of the hydraulic push rod, thereby realizing the relative height adjustment of the metal shell and the roller assembly, and then automatically adjusting the working depth; under a small number of special working conditions, this solution still retains the function of manual adjustment.

[0006] Moreover, in order to take into account both flexibility and power transmission, the present invention also proposes a composite ball-joint transmission mechanism. By coinciding the center point of the mechanical connection with the center point of the power transmission, the flexibility advantage of the ball head drag connection is retained, while the driving force of the front vehicle can be transmitted to the loosening mechanism. This simplifies the structural design of the power harrow, and eliminates the need to set up separate drive and energy storage units for it.

[0007] The technical solution adopted by the present invention is as follows: The present invention provides an adjustable rear-mounted power-driven rake, comprising a passive depth adjustment mechanism, a composite ball-joint transmission mechanism, a loosening mechanism, a metal shell, and a roller assembly. The metal shell is composed of a square portion and a cylindrical portion, the metal shell is connected to a vehicle frame via the composite ball-joint transmission mechanism, and the loosening mechanism is disposed in the metal shell.

[0008] The passive depth adjustment mechanism includes a swing arm assembly and a pressure supply assembly, wherein the swing arm assembly is rotatably mounted on the metal shell, and the pressure supply assembly is disposed between the metal shell and the swing arm assembly;

[0009] Furthermore, the swing arm assembly includes a swing arm body and a fixed hinge, the swing arm body is rotatably arranged at both ends of the metal shell, a top cross bar is provided on the top of the swing arm body, and the fixed hinge is fixed to the metal shell;

[0010] The relative height of the metal shell and the roller assembly can be changed by swinging the swing arm body. Since the roller assembly always rolls on the ground, the swing arm body can change the distance between the metal shell and the bottom surface when swinging, thereby adjusting the loosening depth of the loosening mechanism.

[0011] Preferably, the pressure supply assembly includes a hydraulic pump, a hydraulic push rod and a hydraulic pipeline. The hydraulic pump is arranged in the cylindrical part. The two ends of the hydraulic push rod are hinged to the top cross bar and the fixed hinge platform respectively. An antagonistic spring is provided between the push rod and the cylinder body of the hydraulic push rod. The hydraulic pump and the hydraulic push rod are connected by a hydraulic pipeline.

[0012] The hydraulic pump drives the hydraulic push rod to extend and retract, which can establish a connection between the vehicle's travel speed and the loosening depth, and achieve the technical purpose of automatically controlling the loosening depth through the travel speed. This matching mode can adapt to most normal working conditions and improve the convenience of use under these working conditions; when facing special working conditions, manual settings can still be used.

[0013] As a further preferred embodiment of the present invention, the roller assembly includes a toothed roller and a roller main shaft, the toothed roller is rotatably arranged at the end of the swing arm body, and the roller main shaft is arranged on the toothed roller.

[0014] The roller assembly can not only level the turned soil, but also further break up the soil clods through its own small teeth. It also provides support for the loosening mechanism, avoiding the problem of all weight falling on the ball head connection assembly.

[0015] Furthermore, the composite ball joint transmission mechanism includes a shaft transmission assembly, a universal connection assembly, a steering transmission assembly and a vertical transmission shaft. The shaft transmission assembly and the universal connection assembly are arranged between the metal shell and the frame. The vertical transmission shaft is rotatably arranged in the cylindrical part. The vertical transmission shaft is connected to the output shaft of the hydraulic pump. When the rotation speed of the vertical transmission shaft increases, the hydraulic push rod has a tendency to retract.

[0016] Preferably, the universal connection assembly includes a fixed tube, a swing tube and a ball head connection assembly, and the fixed tube and the swing tube are rotatably connected via the ball head connection assembly, wherein the fixed tube is fixed to the bottom of the frame, one end of the swing tube is fixed to the cylindrical part, and both sides of the swing tube are also fixed to the square part via a connecting rod.

[0017] As a further preferred embodiment of the present invention, the ball head connection assembly includes a hollow ball head, a universal sleeve and a rubber cover, the hollow ball head is fixed to the other end of the swing tube, the universal sleeve is fixed to the bottom of the frame, the hollow ball head is rotatably arranged in the universal sleeve, the rubber cover is arranged between the universal sleeve and the fixed tube, and the rubber cover is arranged between the universal sleeve and the swing tube.

[0018] Preferably, the shaft transmission assembly includes a fixed shaft, a swing shaft and a cross universal joint. The fixed shaft is rotatably arranged in a fixed tube through a bearing, and the fixed shaft is connected to the drive shaft of the vehicle. The swing shaft is rotatably arranged in a swing tube through a bearing, and the fixed shaft and the swing shaft are connected by a cross universal joint.

[0019] The composite ball-joint transmission mechanism is an improvement based on the trailer hook. It makes the center point of the mechanical connection coincide with the center point of the power transmission. This not only retains the flexibility advantage of the ball-head towing connection, but also transmits the driving force of the front vehicle to the loosening mechanism. This simplifies the structural design of the power harrow, eliminating the need for a separate drive and energy storage unit.

[0020] As a further preferred embodiment of the present invention, the steering transmission assembly includes a driving bevel gear and a driven bevel gear, the driving bevel gear is fixed to the swing shaft, the driven bevel gear is fixed to the vertical transmission shaft, and the driving bevel gear and the driven bevel gear are meshed for transmission.

[0021] Furthermore, the loosening mechanism includes a loosening component and a linkage component, the loosening component includes a square base, a rotating shaft and gate-shaped teeth, the square base array is arranged inside the square part, the rotating shaft is rotatably arranged in the square base, and the gate-shaped teeth are fixed to the bottom of the rotating shaft.

[0022] As a further preferred embodiment of the present invention, the linkage assembly includes a driving sprocket, a driven sprocket and a transmission chain, the driven sprocket is fixed to the rotating shaft, the driving sprocket is fixed to the vertical transmission shaft, the driving sprocket and the driven sprocket are transmitted through the transmission chain, and the rotation directions of adjacent driven sprockets are opposite.

[0023] The adjacent gate teeth have different directions and rotate in opposite directions, which can ensure that the wrap angle of the chain drive is large enough and that the sweeping areas of the gate teeth overlap without interference, thereby ensuring that there is no crushing blind area.

[0024] Among them, the hydraulic pump is a vane pump, and the outlet end of the hydraulic push rod is provided with an elastic valve whose opening increases with increasing pressure. The liquid circulates in the hydraulic pump, hydraulic push rod and liquid storage tank.

[0025] Among them, the hydraulic pump is a centrifugal pump, the hydraulic push rod has no outlet, and the liquid flows back and forth in the liquid storage tank, the hydraulic pump and the hydraulic push rod.

[0026] The beneficial effects achieved by the present invention using the above structure are as follows:

[0027] (1) The relative height of the metal shell and the roller assembly can be changed by swinging the swing arm body. Since the roller assembly always rolls on the ground, the swing arm body can change the distance between the metal shell and the bottom surface when it swings, thereby adjusting the loosening depth of the loosening mechanism.

[0028] (2) The hydraulic pump pushes the hydraulic push rod to extend and retract, which can establish a connection between the vehicle's travel speed and the loosening depth, and achieve the technical purpose of automatically controlling the loosening depth by the travel speed. This matching mode can adapt to most normal working conditions and improve the convenience of use under these working conditions; when facing special working conditions, manual settings can still be used.

[0029] (3) The roller assembly can not only level the turned soil, but also further break up the soil blocks through its own small teeth. At the same time, it also provides support for the loosening mechanism, avoiding the problem of all weight falling on the ball head connection assembly.

[0030] (4) The composite ball joint transmission mechanism is an improvement based on the trailer hook. The center point of the mechanical connection coincides with the center point of the power transmission. It not only retains the flexibility advantage of the ball head towing connection, but also can transmit the driving force of the front vehicle to the loosening mechanism. This simplifies the structural design of the power harrow, eliminating the need to set up a separate drive and energy storage unit for it.

[0031] (5) The adjacent gate teeth have different directions and rotate in opposite directions, which can ensure that the wrap angle of the chain drive is large enough and that the sweeping areas of the gate teeth overlap without causing interference, thereby ensuring that there is no crushing blind area. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A perspective view of an adjustable rear-mounted power-driven rake proposed by the present invention;

[0033] Figure 2 A front view of an adjustable rear-mounted power-driven rake proposed by the present invention;

[0034] Figure 3 A left side view of an adjustable rear-mounted power-driven rake proposed by the present invention;

[0035] Figure 4 A top view of an adjustable rear-mounted power-driven rake proposed by the present invention;

[0036] Figure 5 for Figure 3 A cross-sectional view along the cutting line AA;

[0037] Figure 6 for Figure 5 A cross-sectional view along the cutting line BB;

[0038] Figure 7 A schematic diagram of a half-section structure of an adjustable rear-mounted power-driven rake proposed by the present invention;

[0039] Figure 8 for Figure 7 A partial enlarged view of point Ⅰ in the middle;

[0040] Figure 9 for Figure 5 A partial enlarged view of the middle II;

[0041] Figure 10 for Figure 7 A partial enlarged view of point III in the middle;

[0042] Figure 11 Schematic diagram of the connection between the hydraulic pump and the hydraulic push rod Figure 1 ;

[0043] Figure 12 Schematic diagram of the connection between the hydraulic pump and the hydraulic push rod Figure 2 .

[0044] Among them, 1. Passive depth adjustment mechanism, 2. Compound ball joint transmission mechanism, 3. Soil loosening mechanism, 4. Metal shell, 5. Roller assembly, 6. Frame, 7. Swing arm assembly, 8. Pressure supply assembly, 9. Swing arm body, 10. Top cross bar, 11. Fixed hinge platform, 12. Hydraulic pump, 13. Hydraulic push rod, 14. Hydraulic pipeline, 15. Counter spring, 16. Shaft transmission assembly, 17. Universal joint assembly, 18. Steering transmission assembly, 19. Fixed shaft, 20. Fixed pipe, 21. Swing Shaft, 22. Swing tube, 23. Cross universal joint, 24. Ball joint assembly, 25. Vertical transmission shaft, 26. Driving bevel gear, 27. Driven bevel gear, 28. Hollow ball joint, 29. Universal sleeve, 30. Rubber cover, 31. Loosening assembly, 32. Linkage assembly, 33. Square base, 34. Rotating shaft, 35. Gate teeth, 36. Driving sprocket, 37. Driven sprocket, 38. Transmission chain, 39. Square part, 40. Cylindrical part, 41. Toothed roller, 42. Roller spindle.

[0045] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0048] like Figures 1 to 10 As shown, the present invention provides an adjustable rear-mounted power-driven rake, comprising a passive depth adjustment mechanism 1, a composite ball-joint transmission mechanism 2, a loosening mechanism 3, a metal shell 4, and a roller assembly 5. The metal shell 4 is composed of a square portion 39 and a cylindrical portion 40. The metal shell 4 is connected to a frame 6 via the composite ball-joint transmission mechanism 2. The loosening mechanism 3 is disposed in the metal shell 4.

[0049] The passive depth adjustment mechanism 1 includes a swing arm assembly 7 and a pressure supply assembly 8. The swing arm assembly 7 is rotatably mounted on the metal shell 4, and the pressure supply assembly 8 is disposed between the metal shell 4 and the swing arm assembly 7.

[0050] The swing arm assembly 7 includes a swing arm body 9 and a fixed hinge 11. The swing arm body 9 is rotatably mounted on both ends of the metal shell 4. A top crossbar 10 is provided on the top of the swing arm body 9. The fixed hinge 11 is fixed to the metal shell 4.

[0051] By swinging the swing arm body 9, the relative height of the metal shell 4 and the roller assembly 5 can be changed. Since the roller assembly 5 always rolls on the ground, the swing arm body 9 can change the distance between the metal shell 4 and the bottom surface when swinging, thereby adjusting the loosening depth of the loosening mechanism 3.

[0052] The pressure supply assembly 8 includes a hydraulic pump 12, a hydraulic push rod 13, and a hydraulic pipeline 14. The hydraulic pump 12 is arranged in the cylindrical portion 40. The two ends of the hydraulic push rod 13 are respectively hinged to the top cross bar 10 and the fixed hinge platform 11. An antagonistic spring 15 is provided between the push rod and the cylinder body of the hydraulic push rod 13. The hydraulic pump 12 and the hydraulic push rod 13 are connected by a hydraulic pipeline 14.

[0053] The hydraulic pump 12 pushes the hydraulic push rod 13 to extend and retract, which can establish a connection between the vehicle's travel speed and the loosening depth, and achieve the technical purpose of automatically controlling the loosening depth through the travel speed. This matching mode can adapt to most normal working conditions and improve the convenience of use under these working conditions; when facing special working conditions, manual settings can still be used.

[0054] The roller assembly 5 includes a toothed roller 41 and a roller main shaft 42 . The toothed roller 41 is rotatably disposed at the end of the swing arm body 9 , and the roller main shaft 42 is disposed on the toothed roller 41 .

[0055] The roller assembly 5 can not only level the turned-over soil, but also further break up the soil clods through its own small teeth, while also providing support for the loosening mechanism 3 to avoid the problem of all weight falling on the ball head connection assembly 24.

[0056] The composite ball joint transmission mechanism 2 includes a shaft transmission assembly 16, a universal connection assembly 17, a steering transmission assembly 18 and a vertical transmission shaft 25. The shaft transmission assembly 16 and the universal connection assembly 17 are arranged between the metal shell 4 and the frame 6. The vertical transmission shaft 25 is rotatably arranged in the cylindrical portion 40. The vertical transmission shaft 25 is connected to the output shaft of the hydraulic pump 12. When the rotation speed of the vertical transmission shaft 25 increases, the hydraulic push rod 13 has a tendency to retract.

[0057] The universal connection assembly 17 includes a fixed tube 20, a swing tube 22 and a ball head connection assembly 24. The fixed tube 20 and the swing tube 22 are rotatably connected via the ball head connection assembly 24. The fixed tube 20 is fixed to the bottom of the frame 6, one end of the swing tube 22 is fixed to the cylindrical portion 40, and both sides of the swing tube 22 are also fixed to the square portion 39 via a connecting rod.

[0058] The ball head connection assembly 24 includes a hollow ball head 28, a universal sleeve 29 and a rubber cover 30. The hollow ball head 28 is fixed to the other end of the swing tube 22, the universal sleeve 29 is fixed to the bottom of the frame 6, the hollow ball head 28 is rotatably arranged in the universal sleeve 29, the rubber cover 30 is arranged between the universal sleeve 29 and the fixed tube 20, and the rubber cover 30 is arranged between the universal sleeve 29 and the swing tube 22.

[0059] The shaft transmission assembly 16 includes a fixed shaft 19, a swing shaft 21 and a cross universal joint 23. The fixed shaft 19 is rotatably arranged in the fixed tube 20 through a bearing. The fixed shaft 19 is connected to the drive shaft of the vehicle. The swing shaft 21 is rotatably arranged in the swing tube 22 through a bearing. The fixed shaft 19 and the swing shaft 21 are connected by a cross universal joint 23.

[0060] The composite ball-joint transmission mechanism 2 is an improvement based on the trailer hook, which makes the center point of the mechanical connection coincide with the center point of the power transmission. It not only retains the flexibility advantage of the ball head drag connection, but also can transmit the driving force of the front vehicle to the loosening mechanism 3; thereby simplifying the structural design of the power harrow, and eliminating the need to set up a separate drive and energy storage unit for it.

[0061] The steering transmission assembly 18 includes a driving bevel gear 26 and a driven bevel gear 27 . The driving bevel gear 26 is fixed to the swing shaft 21 , and the driven bevel gear 27 is fixed to the vertical transmission shaft 25 . The driving bevel gear 26 and the driven bevel gear 27 are meshed and transmitted.

[0062] The loosening mechanism 3 includes a loosening component 31 and a linkage component 32. The loosening component 31 includes a square base 33, a rotating shaft 34 and a gate-shaped tooth 35. The square base 33 is arranged in an array inside the square part 39. The rotating shaft 34 is rotatably arranged in the square base 33. The gate-shaped tooth 35 is fixedly connected to the bottom of the rotating shaft 34.

[0063] The linkage assembly 32 includes a driving sprocket 36, a driven sprocket 37 and a transmission chain 38. The driven sprocket 37 is fixed to the rotating shaft 34, and the driving sprocket 36 is fixed to the vertical transmission shaft 25. The driving sprocket 36 and the driven sprocket 37 are transmitted through the transmission chain 38, and the adjacent driven sprockets 37 rotate in opposite directions.

[0064] Adjacent gate teeth 35 have different directions and rotate in opposite directions, which can ensure that the wrap angle of the chain drive is large enough and that the sweeping areas of the gate teeth 35 overlap without interference, thereby ensuring that there is no crushing blind area.

[0065] like Figure 11 As shown, the square box represents the liquid storage tank, the hydraulic pump 12 is a pump such as a vane pump, whose speed and flow rate are strongly correlated, and the outlet end of the hydraulic push rod 13 is provided with an elastic valve whose opening increases with increasing pressure, and the liquid circulates in the hydraulic pump 12, the hydraulic push rod 13 and the liquid storage tank;

[0066] The valve core of the elastic valve is connected to the pressure spring. When the internal pressure of the hydraulic push rod 13 changes, the opening of the discharge valve will also change. At the same time, the hydraulic push rod 13 will expand and contract and change the elastic force of the opposing spring 15 until a balanced state is reached again.

[0067] Therefore, in this solution, as the speed of the hydraulic pump 12 increases, the internal pressure of the hydraulic push rod 13 will also increase. At this time, the push rod driving the hydraulic push rod 13 will retract to balance the elastic force and pressure of the counterspring 15; as the speed of the hydraulic pump 12 decreases, the internal pressure of the hydraulic push rod 13 will also decrease. At this time, the push rod driving the hydraulic push rod 13 will extend to balance the elastic force and pressure of the counterspring 15.

[0068] like Figure 12 As shown, the square box represents a liquid storage tank, the hydraulic pump 12 is a pump such as a centrifugal pump whose speed and flow rate are not strongly related, the inlet and outlet of the hydraulic push rod 13 are the same, and the liquid flows back and forth in the liquid storage tank, the hydraulic pump 12 and the hydraulic push rod 13;

[0069] Since the centrifugal pump can run idle, the speed of the hydraulic pump 12 will affect the liquid pressure, but the pressure and flow rate are not absolutely related; if the flow resistance is too large, the flow rate of the liquid will also decrease or even stop flowing;

[0070] Therefore, in this solution, as the speed of the hydraulic pump 12 increases, the internal pressure of the hydraulic push rod 13 will also increase. At this time, the push rod driving the hydraulic push rod 13 will retract to balance the elastic force and pressure of the counterspring 15; as the speed of the hydraulic pump 12 decreases, the internal pressure of the hydraulic push rod 13 will also decrease. At this time, the push rod driving the hydraulic push rod 13 will extend to balance the elastic force and pressure of the counterspring 15.

[0071] like Figure 11 、 12As shown, when encountering special working conditions and needing to manually adjust the working depth, it is only necessary to disconnect the flow path between the hydraulic pump 12 and the hydraulic push rod 13 through the valve, and connect the flow path between the manual pump and the hydraulic push rod 13, and then manually control the amount of liquid pumped into the hydraulic push rod 13, and then control the extension and retraction of the hydraulic push rod 13, so that the height and working depth of the drum assembly 5 can be manually adjusted.

[0072] In specific use, when the vehicle is moving, the fixed shaft 19 is rotated by the driving shaft, and the fixed shaft 19 is rotated by the swing shaft 21 through the cross universal joint 23. Then, the vertical transmission shaft 25 is rotated by the meshing transmission of the driving bevel gear 26 and the driven bevel gear 27. When the driving sprocket 36 rotates with the vertical transmission shaft 25, it can rotate each driven sprocket 37 through the transmission chain 38.

[0073] The rotating gate teeth 35 can cut and turn over the soil below, thereby achieving the technical goal of loosening the soil. Since the transmission chain 38 is wound around the driven sprocket 37 in an alternating manner, on the one hand, it can increase the wrap angle of the transmission chain 38 to the driven sprocket 37 and improve the stability of the transmission. On the other hand, it can also make the adjacent rotating shafts 34 have opposite rotation directions. Therefore, as long as the adjacent gate teeth 35 are installed at perpendicular angles to each other, even if the width of the gate teeth 35 is greater than the axis spacing of the rotating shafts 34, the gate teeth 35 will not interfere with each other during rotation. This also makes the loosening areas of adjacent gate teeth 35 overlap with each other, avoiding blind spots and omissions.

[0074] When working continuously, the toothed roller 41 rolls on the ground, which not only levels the turned-over soil, but also further breaks up the soil blocks through its own small teeth. At the same time, it also provides support for the loosening mechanism 3, avoiding the problem of all weight falling on the ball head connection assembly 24.

[0075] Therefore, by controlling the swing arm body 9 to swing on the metal shell 4, the relative height of the roller assembly 5 and the loosening mechanism 3 can be changed, thereby adjusting the working depth of the loosening.

[0076] When the travel speed increases, the rotation speed of the vertical transmission shaft 25 increases, and the central axis speed of the hydraulic pump 12 increases, and the internal pressure of the hydraulic push rod 13 also increases. At this time, the push rod of the hydraulic push rod 13 is driven to retract so that the elastic force and pressure of the antagonistic spring 15 are balanced. At this time, the roller assembly 5 swings downward relative to the metal shell 4, reducing the working depth of the loosening mechanism 3; and when the travel speed decreases, as the rotation speed of the hydraulic pump 12 decreases, the internal pressure of the hydraulic push rod 13 also decreases. At this time, the push rod of the hydraulic push rod 13 is driven to extend so that the elastic force and pressure of the antagonistic spring 15 are balanced. At this time, the roller assembly 5 swings upward relative to the metal shell 4, increasing the working depth of the loosening mechanism 3;

[0077] Through the above logic, the working depth can be actively controlled by the travel speed, and this matching relationship is also in line with actual needs.

[0078] As an embodiment of the present invention, the hydraulic pump 12 is a pump such as a vane pump, in which the rotation speed and flow rate are strongly correlated. The outlet end of the hydraulic push rod 13 is provided with an elastic valve whose opening increases with increasing pressure. The liquid circulates in the hydraulic pump 12, the hydraulic push rod 13 and the liquid storage tank.

[0079] The valve core of the elastic valve is connected to the pressure spring. When the internal pressure of the hydraulic push rod 13 changes, the opening of the discharge valve will also change. At the same time, the hydraulic push rod 13 will expand and contract and change the elastic force of the antagonistic spring 15 until a balanced state is reached again.

[0080] As another embodiment of the present invention, the hydraulic pump 12 is a pump such as a centrifugal pump whose speed is not strongly related to the flow rate, the inlet and outlet of the hydraulic push rod 13 are the same, and the liquid flows back and forth in the liquid storage tank, the hydraulic pump 12 and the hydraulic push rod 13;

[0081] Since the centrifugal pump can run idle, the speed of the hydraulic pump 12 will affect the liquid pressure, but the pressure and flow rate are not absolutely related; if the resistance to the flow of the liquid is too large, the flow rate of the liquid will also decrease or even stop flowing;

[0082] As a new embodiment of the present invention, the working depth is automatically adjusted by the travel speed, which is suitable for most normal working conditions and can significantly improve the convenience of use under these working conditions. When facing special working conditions, the working depth can still be set manually.

[0083] At this time, it is only necessary to disconnect the flow path between the hydraulic pump 12 and the hydraulic push rod 13 through the valve, and connect the flow path between the manual pump and the hydraulic push rod 13, and then manually control the amount of liquid pumped into the hydraulic push rod 13, and then control the extension and retraction of the hydraulic push rod 13, so that the height and working depth of the drum assembly 5 can be manually adjusted.

[0084] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0085] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. An adjustable rear-mounted power-driven harrow, characterized by: The invention comprises a passive depth adjustment mechanism (1), a composite ball-joint transmission mechanism (2), a soil loosening mechanism (3), a metal shell (4) and a roller assembly (5), wherein the metal shell (4) is composed of a square portion (39) and a cylindrical portion (40), the metal shell (4) is connected to a vehicle frame (6) via the composite ball-joint transmission mechanism (2), and the soil loosening mechanism (3) is arranged in the metal shell (4); The passive depth adjustment mechanism (1) comprises a swing arm assembly (7) and a pressure supply assembly (8), wherein the swing arm assembly (7) is rotatably mounted on the metal shell (4), and the pressure supply assembly (8) is disposed between the metal shell (4) and the swing arm assembly (7); The swing arm assembly (7) comprises a swing arm body (9) and a fixed hinge (11), wherein the swing arm body (9) is rotatably arranged at both ends of the metal shell (4), a top cross bar (10) is provided at the top of the swing arm body (9), and the fixed hinge (11) is fixedly connected to the metal shell (4); The pressure supply assembly (8) includes a hydraulic pump (12), a hydraulic push rod (13) and a hydraulic pipeline (14), wherein the hydraulic pump (12) is arranged in the cylindrical portion (40), and the two ends of the hydraulic push rod (13) are respectively hinged to the top cross bar (10) and the fixed hinge platform (11), and an opposing spring (15) is provided between the push rod and the cylinder body of the hydraulic push rod (13), and the hydraulic pump (12) and the hydraulic push rod (13) are connected through the hydraulic pipeline (14); The roller assembly (5) comprises a toothed roller (41) and a roller main shaft (42), wherein the toothed roller (41) is rotatably arranged at the end of the swing arm body (9), and the roller main shaft (42) is arranged on the toothed roller (41); The composite ball joint transmission mechanism (2) includes a shaft transmission assembly (16), a universal connection assembly (17), a steering transmission assembly (18) and a vertical transmission shaft (25). The shaft transmission assembly (16) and the universal connection assembly (17) are arranged between the metal shell (4) and the vehicle frame (6). The vertical transmission shaft (25) is rotatably arranged in the cylindrical portion (40). The vertical transmission shaft (25) is connected to the output shaft of the hydraulic pump (12). When the rotation speed of the vertical transmission shaft (25) increases, the hydraulic push rod (13) has a tendency to retract. The universal connection assembly (17) includes a fixed tube (20), a swing tube (22) and a ball joint connection assembly (24), wherein the fixed tube (20) and the swing tube (22) are rotatably connected via the ball joint connection assembly (24), wherein the fixed tube (20) is fixed to the bottom of the vehicle frame (6), one end of the swing tube (22) is fixed to the cylindrical portion (40), and both sides of the swing tube (22) are also fixed to the square portion (39) via connecting rods; The ball head connection assembly (24) includes a hollow ball head (28), a universal sleeve (29) and a rubber cover (30), wherein the hollow ball head (28) is fixed to the other end of the swing tube (22), the universal sleeve (29) is fixed to the bottom of the vehicle frame (6), the hollow ball head (28) is rotatably arranged in the universal sleeve (29), the rubber cover (30) is arranged between the universal sleeve (29) and the fixed tube (20), and the rubber cover (30) is arranged between the universal sleeve (29) and the swing tube (22); The shaft transmission assembly (16) includes a fixed shaft (19), a swing shaft (21) and a cross universal joint (23), wherein the fixed shaft (19) is rotatably disposed in a fixed tube (20) via a bearing, the fixed shaft (19) is connected to a driving shaft of a vehicle, and the swing shaft (21) is rotatably disposed in a swing tube (22) via a bearing, the fixed shaft (19) and the swing shaft (21) are connected via a cross universal joint (23), and the loosening depth is automatically controlled by the travel speed; The steering transmission assembly (18) includes a driving bevel gear (26) and a driven bevel gear (27), wherein the driving bevel gear (26) is fixed to the swing shaft (21), and the driven bevel gear (27) is fixed to the vertical transmission shaft (25), and the driving bevel gear (26) and the driven bevel gear (27) are meshed and driven; The loosening mechanism (3) includes a loosening assembly (31) and a linkage assembly (32). The loosening assembly (31) includes a square base (33), a rotating shaft (34) and a gate tooth (35). The gate tooth (35) is fixedly connected to the bottom of the rotating shaft (34). The linkage assembly (32) includes a driving sprocket (36), a driven sprocket (37) and a transmission chain (38). The driven sprocket (37) is fixedly connected to the rotating shaft (34). The driving sprocket (36) is fixedly connected to the vertical transmission shaft (25). The driving sprocket (36) and the driven sprocket (37) are driven by the transmission chain (38).

2. The adjustable rear-mounted power-driven harrow according to claim 1, characterized in that: The square base (33) array is arranged inside the square portion (39), and the rotating shaft (34) is rotatably arranged in the square base (33).

3. The adjustable rear-mounted power-driven harrow according to claim 2, characterized in that: The adjacent driven sprockets (37) rotate in opposite directions.

4. The adjustable rear-mounted power-driven harrow according to claim 1, characterized in that: The hydraulic pump (12) is a vane pump, and a flexible valve whose opening increases with increasing pressure is provided at the liquid outlet end of the hydraulic push rod (13). Liquid circulates in the hydraulic pump (12), the hydraulic push rod (13) and the liquid storage tank.

5. The adjustable rear-mounted power-driven harrow according to claim 1, characterized in that: The hydraulic pump (12) is a centrifugal pump, the hydraulic push rod (13) has no liquid outlet, and the liquid flows back and forth in the liquid storage tank, the hydraulic pump (12) and the hydraulic push rod (13).

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