Open type variable pump hydraulic system for large-dip-angle square bale picking and stacking machine

Abstract

The invention relates to an open type variable pump hydraulic system for a large-dip-angle square bale picking and stacking machine, which comprises a main hydraulic system and an auxiliary hydraulic system, and the main hydraulic system controls the square bale picking and stacking actions of the square bale picking and stacking machine. The auxiliary hydraulic system controls a pickup device mechanism of the square bale pickup stacker crane to ascend, descend and stretch out and draw back, the main hydraulic system comprises a plunger pump, an electric proportional multi-way valve and a plurality of actuators, the plunger pump has the pressure cutting-off and load sensing functions, the electric proportional multi-way valve is provided with an LS valve front pressure compensator, and the actuators are connected with the plunger pump. The hydraulic system has the beneficial effects that fixed difference adjustment of the plunger pump and stepless control of the electric proportional multi-way valve are achieved, the efficiency of the hydraulic system is improved, heating is reduced, no other tedious valve sets exist, unnecessary pipeline connection is reduced, the whole system has high integration, the installation space is saved, and the weight of the whole system is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic systems for stackers, and in particular to an open variable pump hydraulic system for a stacker for picking up square hay bales at large inclination angles. Background Art

[0002] At present, most of the hydraulic control systems used by the straw bale stackers on the market adopt a hydraulic system with a metering pump and a plate-type superimposed valve. In this hydraulic system, the metering pump controls the movement speed and direction of each actuator through a superimposed valve group. During operation, the gear pump always performs high-pressure overflow through the overflow valve to adapt to the flow change of the actuator. This process will cause a large amount of overflow loss. The actuator controls the movement speed through a superimposed throttle valve. This process will cause a large amount of throttling loss. These two phenomena will cause the system output power to be far lower than the input power, the stacker efficiency is low, the workload is heavy, and the stacking quality is poor.

[0003] At the same time, the power loss of the system will be converted into heat energy, causing the temperature of the oil and hydraulic components to rise. The square hay picker is a walking machine. In order to reduce the weight of the hydraulic oil tank, the agricultural machinery system will not be equipped with a radiator. The square hay picker does not have a heat dissipation function. The rapid increase in the temperature of the hydraulic oil will cause the hydraulic oil to deteriorate, the aging of the hydraulic components will be accelerated, the service life of the equipment will be shortened, the maintenance frequency will increase, the frequent replacement of hydraulic oil will cause waste, increase costs, and the replacement and maintenance will cause hydraulic oil leakage to pollute the environment.

[0004] The flow rates of the actuators in the hydraulic system of traditional square bale stackers are unstable. The movement speed of the actuators in the metering pump system will be affected by the engine speed and load. The actuator movement speed will increase when the load decreases, and the actuator movement speed will slow down or even stop when the load increases. At the same time, the superimposed valve groups are all controlled by electromagnetic reversing valves, and the actuator movement speed cannot be accurately controlled according to the design requirements, resulting in poor performance of the picker and inability to match the working conditions according to the specific needs of customers. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides an open variable pump hydraulic system for a large-angle square grass bale picking and stacking machine. The hydraulic system includes a main hydraulic system and an auxiliary hydraulic system. The main hydraulic system controls a plurality of actuators through a variable pump with load sensing and pressure cut-off functions and an electric proportional multi-way valve with pressure compensation before a plate-type LS valve. The plurality of actuators control the square grass picking and stacking actions of the square grass bale picking and stacking machine. The auxiliary hydraulic system controls the lifting and telescopic actions of the square grass bale picking and stacking machine, realizes differential adjustment of the plunger pump, and stepless control of the electric proportional multi-way valve, improves the efficiency of the hydraulic system, reduces heat, does not have other cumbersome valve groups, reduces unnecessary pipeline connections, and has high integration of the whole system, saves installation space, and reduces the weight of the whole machine.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An open variable pump hydraulic system for a large-angle square grass bale picking and stacking machine, comprising a main hydraulic system and an auxiliary hydraulic system, wherein the main hydraulic system controls the square grass picking and stacking actions of the square grass bale picking and stacking machine, and the auxiliary hydraulic system controls the lifting and retracting actions of the picker mechanism of the square grass bale picking and stacking machine;

[0008] The main hydraulic system includes a plunger pump, an electric proportional multi-way valve and several actuators. The several actuators include a lifting and conveying motor, a front push plate cylinder, a platform cylinder, a loading platform cylinder, a vertical barrier cylinder, a rear push rod cylinder, and a grass fork cylinder. The plunger pump has pressure cut-off and load-sensitive functions and is connected to the electric proportional multi-way valve through a hydraulic circuit. The electric proportional multi-way valve is provided with a pressure compensator before the LS valve. The electric proportional multi-way valve is divided into seven hydraulic circuits and respectively connected to control the lifting and conveying motor, the front push plate cylinder, the platform cylinder, the loading platform cylinder, the vertical barrier cylinder, the rear push rod cylinder and the grass fork cylinder. A hydraulically controlled one-way valve is provided on the hydraulic circuit between the electric proportional multi-way valve and the rear push rod cylinder, a hydraulically controlled one-way valve is provided on the hydraulic circuit between the electric proportional multi-way valve and the grass fork cylinder, and an electrically controlled stop valve is provided on the oil inlet pipe and the oil return pipe of the hydraulic circuit between the electric proportional multi-way valve and the platform cylinder.

[0009] Furthermore, the auxiliary hydraulic system includes a lifting cylinder and a guard plate cylinder. The lifting cylinder controls the lifting and lowering of the pickup mechanism of the square bale picking machine, and the guard plate cylinder controls the extension and retraction of the pickup mechanism of the square bale picking and stacking machine.

[0010] Furthermore, the open variable pump hydraulic system of the large-angle square hay bale picking and stacking machine controls the large-angle square hay bale picking and stacking machine, and the square hay bale picking and stacking machine includes a picking mechanism, a chain transmission mechanism, a front push plate mechanism, a platform mechanism, a rear push rod mechanism, a loading platform mechanism, a vertical barrier mechanism and a grass pressing fork mechanism. The picking mechanism is connected to the chain transmission mechanism, the chain transmission mechanism is connected to the lifting and conveying motor, the front push plate mechanism is connected to the front push plate cylinder, the platform structure is connected to the platform cylinder, the rear push rod mechanism is connected to the rear push rod cylinder, the loading platform mechanism is connected to the loading platform cylinder, the vertical barrier mechanism is connected to the vertical barrier cylinder, and the grass pressing fork mechanism is connected to the grass pressing fork cylinder.

[0011] Furthermore, the plunger pump is a swash plate variable displacement plunger pump with pressure cut-off and load sensing functions; a pressure difference of 22 bar is maintained between the oil pressure at the oil outlet of the plunger pump and the oil pressure of the maximum load actuator.

[0012] Furthermore, the electric proportional multi-way valve is a seven-way parallel seven-way reversing unit, and proportional solenoids are arranged on both sides of each reversing unit. The proportional solenoids control the displacement of the reversing valve core arranged in each reversing unit through the input current, thereby controlling the hydraulic flow through the reversing valve core in each reversing unit. An LS valve front pressure compensator is arranged before the position of each reversing valve core, and the outlets of the electric proportional multi-way valve are respectively connected to the hydraulic circuits of the seven-way actuators. A 9 bar pressure difference pressure compensation is set between each reversing unit through the LS valve front pressure compensator.

[0013] Furthermore, the lifting and conveying motor includes two lifting motors and one horizontal conveying motor. The two lifting motors and the horizontal conveying motor are connected in series to an electric proportional multi-way valve, and each motor is individually provided with a solenoid valve group with a bypass cut-off function.

[0014] Furthermore, there are two grass fork oil cylinders, which are connected in parallel and then connected to an electric proportional multi-way valve.

[0015] Furthermore, there are two loading platform oil cylinders, which are connected in parallel to an electric proportional multi-way valve.

[0016] Furthermore, the hydraulically controlled one-way valve and the electrically controlled stop valve are integrated on an electric proportional multi-way valve.

[0017] Furthermore, the working method of the open variable pump hydraulic system for the large-angle square bale picking and stacking machine includes the following contents:

[0018] S1, the plunger pump sucks oil from the hydraulic oil tank, and delivers the high-pressure oil to the oil inlet of the electric proportional multi-way valve through the high-pressure oil filter, and controls the action of the connected actuators through the hydraulic circuits connected by the electric proportional multi-way valve. Then the low-pressure oil that has done work is discharged back to the hydraulic oil tank through the oil outlet of the electric proportional multi-way valve and the low-pressure oil filter;

[0019] S2, the hydraulic circuit of the first reversing link of the electric proportional multi-way valve is connected to the lifting and conveying motor, which includes two lifting motors and a horizontal conveying motor. The hydraulic circuit of the first reversing link of the electric proportional multi-way valve supplies oil to the lifting and conveying motor. When the square grass bale touches the pickup mechanism, the two lifting motors drive the lifting chain of the chain transmission mechanism to convey the square grass bale to the horizontal conveying position to wait for conveying; when there is a square grass bale on the horizontal transmission mechanism, the pickup mechanism no longer picks up the square grass bale, the lifting motor stops, and the horizontal conveying motor drives the horizontal conveying chain of the chain transmission mechanism to convey the square grass bale to the deepest part of the platform mechanism. When the platform mechanism is fully loaded, the horizontal conveying motor no longer conveys the square grass bale to the platform mechanism, and waits for the platform mechanism to unload the square grass bale and return to the working position again, and the horizontal conveying motor moves to convey the square grass bale;

[0020] S3, the front push plate oil cylinder is connected to the hydraulic circuit of the second reversing link of the electric proportional multi-way valve, the hydraulic circuit of the second reversing link of the electric proportional multi-way valve controls the action of the front push plate oil cylinder, and the front push plate oil cylinder controls the front push plate mechanism to push the square straw bale horizontally transmitted to the platform mechanism to one end of the platform mechanism close to the loading platform mechanism;

[0021] S4, the platform oil cylinder is connected to the hydraulic circuit of the fifth reversing link of the electric proportional multi-way valve through the integrated electric control stop valve. When the square grass bales on the platform mechanism are full, the hydraulic circuit of the fifth reversing link of the electric proportional multi-way valve controls the platform oil cylinder to move, and the platform oil cylinder controls the platform mechanism to automatically flip the square grass bales to the loading platform mechanism;

[0022] S5. The two loading platform oil cylinders are connected in parallel to the hydraulic circuit of the sixth reversing link of the electric proportional multi-way valve. When the square grass bales on the loading platform mechanism are full, the hydraulic circuit of the sixth reversing link of the electric proportional multi-way valve controls the loading platform oil cylinder to move, and the loading platform oil cylinder controls the loading platform mechanism to tilt to the maximum tilt angle;

[0023] S6, the rear push rod oil cylinder is connected to the third reversing hydraulic circuit of the electric proportional multi-way valve through the hydraulically controlled one-way valve. After the loading platform mechanism flips to the maximum angle, the third hydraulic circuit of the electric proportional multi-way valve controls the rear push rod oil cylinder to push out the square straw bale. After the square straw bale is completely pushed out of the loading platform mechanism, the rear push rod oil cylinder controls the rear push rod mechanism to retract to its original position.

[0024] S7, the fork pressing cylinder is connected to the hydraulic circuit of the fourth reversing link of the electric proportional multi-way valve through the hydraulic control one-way valve, and the hydraulic circuit of the fourth reversing link of the electric proportional multi-way valve controls the action of the fork pressing cylinder. When the platform mechanism flips and transports the square grass bale to the loading platform mechanism, when the platform mechanism flips and rises to form an angle of 45° with the ground, the fork pressing cylinder controls the fork pressing mechanism to rise. When the platform mechanism flips and rises to form an angle of 88° with the loading platform mechanism, the fork pressing cylinder controls the fork pressing mechanism to press down, fix the flipped and transported square grass bale, and prevent it from falling over.

[0025] S8, the vertical barrier cylinder is connected to the hydraulic circuit of the seventh reversing link of the electric proportional multi-way valve; the hydraulic circuit of the seventh reversing link of the electric proportional multi-way valve controls the action of the vertical barrier cylinder. When there is no square bale on the loading platform mechanism, the vertical barrier cylinder controls the vertical barrier mechanism to rise to the highest point at the front end of the loading platform mechanism, and switches the stacking mode to the picking mode. When the platform mechanism flips over to transport the square bale to the loading platform mechanism, the vertical barrier mechanism contacts the square bale, and the vertical barrier cylinder controls the vertical barrier mechanism to maintain the supporting position to prevent the square bale from falling. When the loading platform is fully loaded, the deadweight of the square bale presses the vertical barrier mechanism to the very end of the loading platform mechanism.

[0026] S9. The auxiliary hydraulic system has two hydraulic circuits to control the lifting cylinder and the guard plate cylinder. When the square bale picking and stacking machine is working, the lifting cylinder controls the picking mechanism to descend to the picking position, and the guard plate cylinder controls the picking mechanism to fully expand and start picking up square bales; when the square bales are picked up and piled on the loading platform mechanism to prepare for unloading, the guard plate cylinder controls the picking mechanism to retract, and the lifting cylinder controls the lifting of the picking mechanism to the highest point.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1) The variable displacement piston pump with load sensing and pressure cut-off function feeds back the pressure and flow change signals to the piston pump to realize the control function; a pump displacement differential regulating valve is set to maintain a 22 bar pressure difference between the pump outlet oil pressure and the maximum load actuator oil pressure to adjust the pump displacement. It has the characteristics of low standby pressure and fast response, which improves the working efficiency of the hydraulic system, improves the working efficiency of the square hay picking and stacking machine, and improves the working effect of the square hay picking and stacking machine.

[0029] 2) The electric proportional multi-way valve with pressure compensation before the LS valve has a pressure-compensated flow control that is not affected by changes in load pressure and hydraulic pump flow. It is automatically controlled by the set 9bar pressure difference value to achieve stepless control. The square straw picker and stacker can provide the required flow with accurate flow control, which reduces power loss caused by overflow and improves the working efficiency of the square straw picker and stacker. At the same time, it reduces the heat generation of the system, avoids the rapid increase in hydraulic oil temperature which will cause the hydraulic oil to deteriorate and accelerate the aging of hydraulic components, thus improving the service life of the square straw picker and stacker.

[0030] 3) There are no other complicated valve groups between the outlet of the electric proportional multi-way valve and each actuator, which reduces unnecessary pipeline connections; the hydraulic system has high integration, saves installation space, reduces the weight of the whole machine, has a simple structure, and the square straw picking and stacking machine works accurately, has good picking and stacking effect, and is highly efficient.

[0031] 4) The auxiliary hydraulic system controls the picking mechanism of the square straw bale picker to lower when working and to fold it up after work. The action is simple and there is no performance requirement. The auxiliary hydraulic system is separated from the main system and connected to the hydraulic valve block on the tractor separately, making the main hydraulic system layout simpler and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the main hydraulic system of the present invention.

[0033] Figure 2 It is a schematic diagram of the auxiliary hydraulic system of the present invention.

[0034] Figure 3 It is a schematic diagram of the external structure of the square grass bale picking machine described in the present invention.

[0035] Figure 4 It is a structural schematic diagram of the electric proportional multi-way valve described in the present invention.

[0036] Figure 5 The present invention discloses a hydraulic system schematic diagram of a conventional square bale picker.

[0037] In the figure: 1. Pickup mechanism; 2. Chain transmission mechanism; 3. Hydraulic oil tank; 4. Front push plate mechanism; 5. Platform mechanism; 6. Rear push rod mechanism; 7. Loading platform mechanism; 8. Vertical barrier mechanism; 9. Grass fork mechanism; 10. Gear pump; 11. Superimposed valve group; 12. Piston pump; 13. Electric proportional multi-way valve; 14. Lifting and conveying motor; 15. Front push plate cylinder; 16. Hydraulic control check valve I; 17. Rear push rod cylinder; 18. Hydraulic control One-way valve II; 19. Pitchfork cylinder; 20. Electric stop valve; 21. Platform cylinder; 22. Loading platform cylinder; 23. Vertical barrier cylinder; 24. One-way throttle valve; 25. Overflow valve; 26. Sequence valve; 27. Throttle valve; 28. Pickup mechanism telescopic cylinder; 29. ​​Pickup mechanism lifting cylinder; 30. Horizontal transmission motor; 31. Lifting motor; 32. Emergency handle; 33. Proportional solenoid; 34. LS overflow valve. DETAILED DESCRIPTION

[0038] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0039] like Figure 1-Figure 5 As shown, different from the hydraulic system of the traditional square grass bale picking machine through the gear pump 10 plus the plate type superimposed valve group 11, an open variable pump hydraulic system for the large-angle square grass bale picking and stacking machine includes a main hydraulic system and an auxiliary hydraulic system. The main hydraulic system controls the square grass picking and stacking of the square grass bale picking and stacking machine, and the auxiliary hydraulic system controls the lifting and retraction of the picker mechanism 1 of the square grass bale picking and stacking machine.

[0040] like Figure 1 As shown, the main hydraulic system includes a plunger pump 12, an electric proportional multi-way valve 13 and a number of actuators, the actuators include a lifting and conveying motor 14, a front push plate cylinder 15, a platform cylinder 21, a loading platform cylinder 22, a vertical barrier cylinder 23, a rear push rod cylinder 17, and a grass fork cylinder 19. The plunger pump 12 is connected to the electric proportional multi-way valve 13 through a pipeline, and the electric proportional multi-way valve 13 is divided into seven ways to connect the actuators respectively.

[0041] The plunger pump 12 is a variable displacement pump with load sensing and pressure cut-off functions. It feeds back pressure and flow change signals to the plunger pump 12 to realize the control function. The plunger pump 12 displacement differential regulating valve is set to maintain a 22 bar pressure difference between the oil pressure at the outlet of the plunger pump 12 and the oil pressure of the maximum load actuator to adjust the displacement of the plunger pump 12. It has the characteristics of low standby pressure and fast response. When the square straw bale picker is not in motion, the plunger pump 12 is in a low pressure and micro flow state (only the hydraulic system leakage flow is maintained); when the motor and cylinder actuators move to the end of the stroke, the automatic variable maintains a high pressure and micro flow state (only the hydraulic system leakage flow is maintained); improve the efficiency of the hydraulic system and reduce heat.

[0042] like Figure 4 As shown, the electric proportional multi-way valve 13 includes seven parallel reversing links with proportional electromagnets 33, a pressure compensator before the LS valve, an LS relief valve 34, and an emergency handle 32. Proportional electromagnets 33 are arranged on both sides of each reversing link of the electric proportional multi-way valve, and a reversing valve core is arranged in each reversing link. An emergency handle 32 is arranged on each link of the electric proportional multi-way valve, so that each hydraulic circuit can be manually controlled individually. The proportional solenoid 33 controls the displacement of each reversing valve core by the input current, thereby controlling the flow through each reversing valve core. An LS valve pre-pressure compensator is set before each reversing valve core position. The pressure oil first passes through the LS valve pre-pressure compensator and then passes through the reversing valve core. The LS valve pre-pressure compensator sets a 9bar pressure difference for pressure compensation, so that the flow through the reversing valve core is not disturbed by the load. The flow through each reversing link is only affected by the 9bar pressure difference set by the LS valve pre-pressure compensator and the current input by the proportional solenoid to control the displacement of each reversing valve core, and is not affected by the load pressure change and the flow change of the plunger pump 12, and the output flow is linearly related to the valve core position. The flow control is automatically controlled by the set 9bar pressure difference value, and is stepless control; the flow output by the plunger pump 12 is independent of the load change and the engine speed; the electric proportional multi-way valve 13 provides as much flow as each actuator of the square straw bale picking and stacking machine requires, thereby improving the efficiency of the picking and stacking machine and reducing heat generation.

[0043] like Figure 1As shown, the electric proportional multi-way valve 13 is divided into seven hydraulic circuits, which are respectively connected to control the lifting and conveying motor 14, the front push plate cylinder 15, the platform cylinder 21, the loading platform cylinder 22, the vertical barrier cylinder 23, the rear push rod cylinder 17 and the grass fork cylinder 19. A hydraulic control non-return valve I16 is arranged on the hydraulic circuit between the electric proportional multi-way valve 13 and the rear push rod cylinder 17, and a hydraulic control non-return valve II18 is arranged on the hydraulic circuit between the electric proportional multi-way valve 13 and the grass fork cylinder 19. The rear push rod mechanism 6 and the grass fork mechanism 9 connected with 17 and the grass fork oil cylinder 19 are used for arranging and stacking square grass bales. Their positions cannot be changed by external forces. Therefore, a hydraulically controlled one-way valve is used for maintaining pressure and locking to prevent the actuator from changing its position due to its own weight or external forces. The selected hydraulically controlled one-way valve can be superimposed with the electric proportional multi-way valve 13, which has a more compact structure and more accurate control, so that the square grass bales can be neatly stacked. The oil inlet pipe and return pipe of the hydraulic circuit between the electric proportional multi-way valve 13 and the platform oil cylinder 21 are The oil pipes are respectively provided with electric control stop valves 20, and the platform cylinder 21 is connected to the platform mechanism 5. The platform mechanism 5 is turned over to turn the square grass bale onto the loading platform mechanism 7. The platform cylinder 21 needs to have a position keeping function during operation. The hydraulic circuit of the platform cylinder 21 is provided with an electric control stop valve 20, and the electric control stop valve 20 is superimposed with the electric proportional multi-way valve 13. When the electromagnet is energized, the platform cylinder 21 works normally. When the electromagnet is de-energized, the platform cylinder 21 keeps the current position regardless of the system operation, which is convenient for maintenance and safety protection. The use of this system, the plunger pump 12 with load sensitive variables and the electric proportional multi-way valve 13 form a load sensitive system, which detects the load pressure, flow and power change signals by induction, and feeds back to the hydraulic system, so as to realize energy-saving control, flow and speed control, simultaneous action and prime mover power matching. There is no other cumbersome valve group between the outlet of the electric proportional multi-way valve 13 and each actuator, which reduces unnecessary pipeline connections; the hydraulic system has high integration, saves installation space, and reduces the weight of the whole machine.

[0044] No overflow valve is set on the hydraulic circuit of the front push plate cylinder 15, the rear push rod cylinder 17 and the grass fork cylinder 19. Instead, an LS overflow valve 34 is set in the return oil circuit of the pressure compensator in front of the LS valve of the reversing link of the electric proportional multi-way valve 13 to limit the pressure, reduce the power loss caused by the overflow, and reduce the heat generation of the system.

[0045] like Figure 2As shown, the auxiliary hydraulic system includes a lifting cylinder 28 and a guard plate cylinder 29, and the lifting cylinder 28 and the guard plate cylinder 29 are supplied with oil through two hydraulic circuits respectively. One hydraulic circuit enters the auxiliary hydraulic system from port A, and the hydraulic circuit at port A is divided into three oil circuits. The first oil circuit is directly connected to the rod cavity of the lifting cylinder 28, the second oil circuit returns oil from another circuit through the overflow valve 25 and the one-way throttle valve 24, and the third oil circuit is connected to the throttle valve 27 and the rod cavity of the guard plate cylinder 29 through the one-way sequence valve 26; the other hydraulic circuit enters the auxiliary hydraulic system from port B, and the hydraulic circuit at port B is also divided into three oil circuits after passing through the one-way throttle valve 24, the first oil circuit is connected to the oil drain port of the overflow valve 25, the second oil circuit is directly connected to the rodless cavity of the guard plate cylinder 29, and the third oil circuit is connected to the rodless cavity of the lifting cylinder 28 through the one-way throttle valve 24. The auxiliary hydraulic system is mainly responsible for the lowering of the pickup mechanism of the square bale picker and the folding after work. The lifting cylinder 28 of the auxiliary hydraulic system controls the lifting and lowering of the pickup mechanism, and the guard plate cylinder 29 controls the extension and retraction of the pickup mechanism. The operation is simple and there is no performance requirement. The auxiliary hydraulic system is separated from the main hydraulic system and connected to the hydraulic valve block on the tractor separately, making the main hydraulic system layout simpler and reducing costs.

[0046] like Figure 3 As shown, further, the open variable pump hydraulic system of the large-angle square grass bale picking and stacking machine controls the large-angle square grass bale picking and stacking machine, which includes a picking mechanism 1, a chain transmission mechanism 2, a hydraulic oil tank 3, a front push plate mechanism 4, a platform mechanism 5, a rear push rod mechanism 6, a loading platform mechanism 7, a vertical barrier mechanism 8 and a grass pressing fork mechanism 9. The picking mechanism is connected to the chain transmission mechanism 2, and the chain transmission mechanism 2 is connected to the lifting and conveying motor 14. The front push plate mechanism 4 is connected to the front push plate cylinder 15, and the platform mechanism 5 is connected to the platform cylinder 21. The rear push rod mechanism 6 is connected to the rear push rod cylinder 17, and the loading platform mechanism 7 is connected to the loading platform cylinder 22. The vertical barrier mechanism 8 is connected to the vertical barrier cylinder 23, and the grass pressing fork mechanism 9 is connected to the grass pressing fork cylinder 19.

[0047] like Figure 1 As shown, further, the lifting and conveying motor 14 includes two lifting motors 31 and a horizontal conveying motor 30. The lifting motor 31 and the horizontal conveying motor 30 are connected in series to the electric proportional multi-way valve 13. Each motor has a separate solenoid valve group with a bypass cut-off function, and the action of each motor is controlled by the gain and loss of electricity of the solenoid valve.

[0048] like Figure 1As shown, further, there are two grass fork oil cylinders 19, the two grass fork oil cylinders 19 are connected in parallel to the electric proportional multi-way valve 13, and the grass fork oil cylinders 19 are arranged on both sides of the grass fork mechanism 9. The two grass fork oil cylinders 19 supply oil at the same time, driving the grass fork mechanism 9 to move smoothly.

[0049] like Figure 1 As shown, further, there are two loading platform cylinders 22, and the two loading platform cylinders 22 are connected in parallel to the electric proportional multi-way valve 13. The loading platform cylinders 22 are arranged on both sides of the loading platform mechanism 7. The two loading platform cylinders 22 operate simultaneously to support the loading platform mechanism 7 from both sides to smoothly and stably increase the tilting angle.

[0050] like Figure 4 As shown, further, the hydraulically controlled one-way valve I16, the hydraulically controlled one-way valve II18 and the electrically controlled stop valve 20 are integrated on the electric proportional multi-way valve 13.

[0051] like Figure 1-Figure 4 As shown, further, the working method of the open variable pump hydraulic system for the large-angle square bale picking and stacking machine includes the following contents:

[0052] S1, the plunger pump 12 sucks oil from the hydraulic oil tank 3, and delivers the high-pressure oil to the oil inlet of the electric proportional multi-way valve 13 through the high-pressure oil filter, and controls the action of the connected actuators through the various working hydraulic circuits connected by the electric proportional multi-way valve 13, and then the low-pressure oil that has done work is discharged back to the hydraulic oil tank 3 through the oil outlet of the electric proportional multi-way valve 13 and the low-pressure oil filter;

[0053] S2, the hydraulic circuit of the first reversing link of the electric proportional multi-way valve 13 is connected to the lifting and conveying motor 14, and the lifting and conveying motor 14 includes two lifting motors 31 and a horizontal conveying motor 30. The hydraulic circuit of the first reversing link of the electric proportional multi-way valve 13 supplies oil to the lifting and conveying motor 14. When the square grass bale touches the pickup mechanism, the lifting motor 31 drives the lifting chain of the chain transmission mechanism 2 to lift the square grass bale and convey it to the horizontal conveying position to wait for conveying; when there is a square grass bale on the horizontal transmission mechanism, the pickup mechanism no longer picks up the square grass bale, the lifting motor 31 stops, and the horizontal conveying motor 30 drives the horizontal conveying chain of the chain transmission mechanism 2 to convey the square grass bale to the deepest part of the platform mechanism 5. When the platform mechanism 5 is fully loaded, the horizontal conveying motor 30 no longer conveys the square grass bale to the platform mechanism 5, and waits for the platform mechanism 5 to unload the square grass bale and return to the working position again, and the horizontal conveying motor 30 acts to convey the square grass bale;

[0054] S3, the front push plate oil cylinder 15 is connected to the hydraulic circuit of the second reversing link of the electric proportional multi-way valve 13, the hydraulic circuit of the second reversing link of the electric proportional multi-way valve 13 controls the action of the front push plate oil cylinder 15, and the front push plate oil cylinder 15 controls the front push plate mechanism 4 to push the square grass bale horizontally transferred to the platform mechanism 5 to the end of the platform mechanism 5 close to the loading platform mechanism 7;

[0055] S4, the platform oil cylinder 21 is connected to the hydraulic circuit of the fifth reversing link of the electric proportional multi-way valve 13 through the integrated electric control stop valve 20. When the square grass bales on the platform mechanism 5 are full, the hydraulic circuit of the fifth reversing link of the electric proportional multi-way valve 13 controls the platform oil cylinder 21 to operate, and the platform oil cylinder 21 controls the platform mechanism 5 to automatically flip the square grass bales to the loading platform mechanism 7;

[0056] S5, the two loading platform cylinders 22 are connected in parallel to the hydraulic circuit of the sixth reversing connection of the electric proportional multi-way valve 13. When the square grass bales on the loading platform mechanism 7 are full, the hydraulic circuit of the sixth reversing connection of the electric proportional multi-way valve 13 controls the loading platform cylinder 22 to move, and the loading platform cylinder 22 controls the loading platform mechanism 7 to tilt to the maximum tilt angle;

[0057] S6, the rear push rod oil cylinder 17 is connected to the hydraulic circuit of the third reversing link of the electric proportional multi-way valve 13 through the hydraulically controlled one-way valve I16. After the loading platform mechanism 7 is flipped to the maximum angle, the hydraulic circuit of the third reversing link of the electric proportional multi-way valve 13 controls the rear push rod oil cylinder 17 to move, and the rear push rod oil cylinder 17 controls the rear push rod mechanism 6 to push out the square grass bale. After the square grass bale is completely pushed out of the loading platform mechanism 7, the rear push rod oil cylinder 17 controls the rear push rod mechanism 7 to retract to the original position, and the loading platform oil cylinder 22 controls the loading platform mechanism 7 to fall back to the original position;

[0058] S7, the fork pressing cylinder 19 is connected to the hydraulic circuit of the fourth reversing link of the electric proportional multi-way valve 13 through the hydraulic control one-way valve II18. The hydraulic circuit of the fourth reversing link of the electric proportional multi-way valve 13 controls the action of the fork pressing cylinder 19. When the platform mechanism 5 flips and transports the square grass bale to the loading platform mechanism 7, when the platform mechanism 5 flips and rises to form an angle of 45° with the ground, the fork pressing cylinder 19 controls the fork pressing mechanism 9 to rise. When the platform mechanism 5 flips and rises to form an angle of 88° with the loading platform mechanism 7, the fork pressing cylinder 19 controls the fork pressing mechanism 9 to press down, fix the flipped and transported square grass bale, and prevent it from falling over.

[0059] S8, the vertical barrier cylinder 23 is connected to the hydraulic circuit of the seventh reversing link of the electric proportional multi-way valve 13; the hydraulic circuit of the seventh reversing link of the electric proportional multi-way valve 13 controls the action of the vertical barrier cylinder 23. When there is no square bale on the loading platform mechanism, the vertical barrier cylinder controls the vertical barrier mechanism to rise to the highest point at the front end of the loading platform mechanism, and switches the stacking mode to the picking mode. When the platform mechanism flips over to transport the square bale to the loading platform mechanism, the vertical barrier mechanism contacts the square bale, and the vertical barrier cylinder controls the vertical barrier mechanism to maintain the supporting position to prevent the square bale from falling. When the loading platform is fully loaded, the deadweight of the square bale presses the vertical barrier mechanism to the very end of the loading platform mechanism.

[0060] S9. The auxiliary hydraulic system has two hydraulic circuits to control the lifting cylinder 28 and the guard plate cylinder 29. When the square bale picking and stacking machine is working, the lifting cylinder 28 controls the picking mechanism to descend to the picking position, and the guard plate cylinder 29 controls the picking mechanism to open and pick up the square bales. When the square bales are picked up and piled on the loading platform mechanism 7 to prepare for unloading, the guard plate cylinder 29 controls the picking mechanism to shrink, and the lifting cylinder 28 controls the lifting of the picking mechanism to the highest point.

[0061] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An open variable pump hydraulic system for a large-angle square bale picking and stacking machine, comprising a main hydraulic system and an auxiliary hydraulic system, characterized in that: The main hydraulic system controls the picking and stacking actions of the square bale picking and stacking machine, and the auxiliary hydraulic system controls the lifting and retracting actions of the picker mechanism of the square bale picking and stacking machine; The main hydraulic system includes a plunger pump, an electric proportional multi-way valve and several actuators. The several actuators include a lifting and conveying motor, a front push plate cylinder, a platform cylinder, a loading platform cylinder, a vertical barrier cylinder, a rear push rod cylinder, and a grass fork cylinder. The plunger pump has pressure cut-off and load-sensitive functions and is connected to the electric proportional multi-way valve through a hydraulic circuit. The electric proportional multi-way valve is provided with a pressure compensator before the LS valve. The electric proportional multi-way valve is divided into seven hydraulic circuits and respectively connected to control the lifting and conveying motor, the front push plate cylinder, the platform cylinder, the loading platform cylinder, the vertical barrier cylinder, the rear push rod cylinder and the grass fork cylinder. A hydraulically controlled one-way valve is provided on the hydraulic circuit between the electric proportional multi-way valve and the rear push rod cylinder, a hydraulically controlled one-way valve is provided on the hydraulic circuit between the electric proportional multi-way valve and the grass fork cylinder, and an electrically controlled stop valve is provided on the oil inlet pipe and the oil return pipe of the hydraulic circuit between the electric proportional multi-way valve and the platform cylinder.

2. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: The auxiliary hydraulic system comprises a lifting cylinder and a guard plate cylinder. The lifting cylinder controls the lifting and lowering of the picker mechanism of the square straw bale picker, and the guard plate cylinder controls the extension and retraction of the picker mechanism of the square straw bale picker and stacker.

3. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: The open variable pump hydraulic system of the large-angle square grass bale picking and stacking machine controls the large-angle square grass bale picking and stacking machine. The square grass bale picking and stacking machine includes a picking mechanism, a chain transmission mechanism, a front push plate mechanism, a platform mechanism, a rear push rod mechanism, a loading platform mechanism, a vertical barrier mechanism and a grass pressing fork mechanism. The picking mechanism is connected to the chain transmission mechanism, the chain transmission mechanism is connected to the lifting and conveying motor, the front push plate mechanism is connected to the front push plate cylinder, the platform structure is connected to the platform cylinder, the rear push rod mechanism is connected to the rear push rod cylinder, the loading platform mechanism is connected to the loading platform cylinder, the vertical barrier mechanism is connected to the vertical barrier cylinder, and the grass pressing fork mechanism is connected to the grass pressing fork cylinder.

4. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: The plunger pump is a slant plate variable displacement plunger pump with pressure cut-off and load sensing functions; a pressure difference of 22 bar is maintained between the oil pressure at the oil outlet of the plunger pump and the oil pressure of the maximum load actuator.

5. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: The electric proportional multi-way valve is a seven-way parallel seven-way reversing link. Proportional electromagnets are arranged on both sides of each reversing link. The proportional electromagnets control the displacement of the reversing valve core arranged in each reversing link through the input current, thereby controlling the hydraulic flow through the reversing valve core in each reversing link. An LS valve front pressure compensator is arranged before each reversing valve core position. The outlets of the electric proportional multi-way valve are respectively connected to the hydraulic circuits of the seven-way actuators. A 9bar pressure difference pressure compensation is set between each reversing link through the LS valve front pressure compensator.

6. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: The lifting and conveying motors include two lifting motors and one horizontal conveying motor. The two lifting motors and the horizontal conveying motor are connected in series to an electric proportional multi-way valve. Each motor is individually provided with a solenoid valve group with a bypass cut-off function.

7. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: There are two grass fork oil cylinders, which are connected in parallel and then connected to an electric proportional multi-way valve.

8. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: There are two loading platform oil cylinders, which are connected in parallel and then connected to an electric proportional multi-way valve.

9. The open variable pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: The hydraulically controlled one-way valve and the electrically controlled stop valve are integrated on the electric proportional multi-way valve.

10. A method for operating an open variable displacement pump hydraulic system for a large-angle square bale picker and stacker according to claim 1, characterized in that: The working method of the open variable pump hydraulic system for the large-angle square bale picking and stacking machine includes the following contents: S1, the plunger pump sucks oil from the hydraulic oil tank, and delivers the high-pressure oil to the oil inlet of the electric proportional multi-way valve through the high-pressure oil filter, and controls the action of the connected actuators through the hydraulic circuits connected by the electric proportional multi-way valve. Then the low-pressure oil that has done work is discharged back to the hydraulic oil tank through the oil outlet of the electric proportional multi-way valve and the low-pressure oil filter; S2, the hydraulic circuit of the first reversing link of the electric proportional multi-way valve is connected to the lifting and conveying motor, which includes two lifting motors and a horizontal conveying motor. The hydraulic circuit of the first reversing link of the electric proportional multi-way valve supplies oil to the lifting and conveying motor. When the square grass bale touches the pickup mechanism, the two lifting motors drive the lifting chain of the chain transmission mechanism to convey the square grass bale to the horizontal conveying position to wait for conveying; when there is a square grass bale on the horizontal transmission mechanism, the pickup mechanism no longer picks up the square grass bale, the lifting motor stops, and the horizontal conveying motor drives the horizontal conveying chain of the chain transmission mechanism to convey the square grass bale to the deepest part of the platform mechanism. When the platform mechanism is fully loaded, the horizontal conveying motor no longer conveys the square grass bale to the platform mechanism, and waits for the platform mechanism to unload the square grass bale and return to the working position again, and the horizontal conveying motor moves to convey the square grass bale; S3, the front push plate oil cylinder is connected to the hydraulic circuit of the second reversing link of the electric proportional multi-way valve, the hydraulic circuit of the second reversing link of the electric proportional multi-way valve controls the action of the front push plate oil cylinder, and the front push plate oil cylinder controls the front push plate mechanism to push the square straw bale horizontally transmitted to the platform mechanism to one end of the platform mechanism close to the loading platform mechanism; S4, the platform oil cylinder is connected to the hydraulic circuit of the fifth reversing link of the electric proportional multi-way valve through the integrated electric control stop valve. When the square grass bales on the platform mechanism are full, the hydraulic circuit of the fifth reversing link of the electric proportional multi-way valve controls the platform oil cylinder to move, and the platform oil cylinder controls the platform mechanism to flip the square grass bales to the loading platform mechanism; S5. The two loading platform oil cylinders are connected in parallel to the hydraulic circuit of the sixth reversing link of the electric proportional multi-way valve. When the square grass bales on the loading platform mechanism are full, the hydraulic circuit of the sixth reversing link of the electric proportional multi-way valve controls the loading platform oil cylinder to move, and the loading platform oil cylinder controls the loading platform mechanism to tilt to the maximum tilt angle; S6, the rear push rod oil cylinder is connected to the third reversing hydraulic circuit of the electric proportional multi-way valve through the hydraulically controlled one-way valve. After the loading platform mechanism flips to the maximum angle, the third hydraulic circuit of the electric proportional multi-way valve controls the rear push rod oil cylinder to push out the square straw bale. After the square straw bale is completely pushed out of the loading platform mechanism, the rear push rod oil cylinder controls the rear push rod mechanism to retract to its original position. S7, the fork pressing cylinder is connected to the hydraulic circuit of the fourth reversing link of the electric proportional multi-way valve through the hydraulic control one-way valve, and the hydraulic circuit of the fourth reversing link of the electric proportional multi-way valve controls the action of the fork pressing cylinder. When the platform mechanism flips and transports the square grass bale to the loading platform mechanism, when the platform mechanism flips and rises to form an angle of 45° with the ground, the fork pressing cylinder controls the fork pressing mechanism to rise. When the platform mechanism flips and rises to form an angle of 88° with the loading platform mechanism, the fork pressing cylinder controls the fork pressing mechanism to press down, fix the flipped and transported square grass bale, and prevent it from falling over. S8, the vertical barrier cylinder is connected to the hydraulic circuit of the seventh reversing link of the electric proportional multi-way valve; the hydraulic circuit of the seventh reversing link of the electric proportional multi-way valve controls the action of the vertical barrier cylinder. When there is no square bale on the loading platform mechanism, the vertical barrier cylinder controls the vertical barrier mechanism to rise to the highest point at the front end of the loading platform mechanism, and switches the stacking mode to the picking mode. When the platform mechanism flips over to transport the square bale to the loading platform mechanism, the vertical barrier mechanism contacts the square bale, and the vertical barrier cylinder controls the vertical barrier mechanism to maintain the supporting position to prevent the square bale from falling. When the loading platform is fully loaded, the deadweight of the square bale presses the vertical barrier mechanism to the very end of the loading platform mechanism. S9. The auxiliary hydraulic system has two hydraulic circuits to control the lifting cylinder and the guard plate cylinder. When the square bale picking and stacking machine is working, the lifting cylinder controls the picking mechanism to descend to the picking position, and the guard plate cylinder controls the picking mechanism to fully expand and start picking up square bales; when the square bales are picked up and piled on the loading platform mechanism to prepare for unloading, the guard plate cylinder controls the picking mechanism to retract, and the lifting cylinder controls the lifting of the picking mechanism to the highest point.

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