A bale press and hydraulic control system for its knife retraction protection

Abstract

The application discloses a baling machine and a hydraulic control system for knife retraction protection thereof, and relates to the technical field of agricultural machinery. The hydraulic control system comprises an oil inlet pipeline, an oil return pipeline, a reversing valve, a working oil cylinder and an accumulator. The oil inlet of the reversing valve is communicated with the oil inlet pipeline, the oil return of the reversing valve is communicated with the oil return pipeline, the first working oil port of the reversing valve is communicated with the rodless cavity of the working oil cylinder, and the second working oil port of the reversing valve is communicated with the rod cavity of the working oil cylinder. The reversing valve is used for controlling the communication between the oil inlet pipeline and the rodless cavity or the rod cavity of the working oil cylinder, and the reversing valve has a Y-type neutral function. The working oil cylinder is used for controlling the synchronous extension and retraction of the knife through the extension and retraction movement of the piston rod. The accumulator is simultaneously communicated with the first working oil port of the reversing valve and the rodless cavity of the working oil cylinder. The application can ensure that the retraction distance of the knife matches the size of foreign matters, improve the protection effect of the knife, realize stepless adjustment of the initial cutting force of the knife, and conveniently realize the switching of the working state of the knife.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, and in particular to a hydraulic control system for cutter retraction protection. This invention also relates to a baler. Background Technology

[0002] With the development of animal husbandry and the centralization of cattle and sheep breeding, farmers' demand for and storage of feed have increased. The efficiency of manual harvesting and storage of hay is low. With the development of modern agricultural mechanization, balers play an important role in the harvesting, chopping, storage and transportation of hay.

[0003] The cutter is an important component of the baler. Weeds enter the shredding system through the feeding system, and the cutter blades shred the weeds. Due to the uncertainty and complexity of the on-site environment, hard foreign objects, such as small stones, are often mixed in with the weeds when the cutter is cutting. If the cutter blades are not protected, the blades are prone to breakage and jamming.

[0004] Currently, the main method for protecting baler cutter blades is through mechanical springs. However, this mechanical spring protection structure has several drawbacks: 1. Due to the inertia of the spring, the buffering effect is poor, the blade's floating distance is small, and the cutter's retraction distance is always slightly smaller than the size of the foreign object, which may still cause it to get stuck, resulting in poor protection and a risk of blade damage; 2. Once the spring is selected, the initial supporting working pressure of the blade is fixed, making it impossible to achieve stepless adjustment of the initial cutting force; 3. Due to the mechanical characteristics, depending on whether the straw needs to be cut, the mechanical structure needs to be manually operated to adjust the cutter to the working or non-working position, making the method of switching the cutter's working state cumbersome.

[0005] Therefore, how to ensure that the retraction distance of the cutter matches the size of the foreign object, improve the protection effect of the cutter, achieve stepless adjustment of the initial cutting force of the cutter, and facilitate the switching of the working state of the cutter are technical problems faced by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a hydraulic control system for cutter retraction protection, which ensures that the cutter retraction distance matches the size of the foreign object, improving the protection effect of the cutter, while simultaneously enabling stepless adjustment of the initial cutting force of the cutter and convenient switching of the cutter's working state. Another purpose of this invention is to provide a baling machine.

[0007] To solve the above-mentioned technical problems, the present invention provides a hydraulic control system for cutter retraction protection, including an oil inlet pipeline, an oil return pipeline, a reversing valve, a working cylinder, and an accumulator;

[0008] The oil inlet of the reversing valve is connected to the oil inlet pipeline, the oil return port of the reversing valve is connected to the oil return pipeline, the first working oil port of the reversing valve is connected to the rodless chamber of the working cylinder, and the second working oil port of the reversing valve is connected to the rod chamber of the working cylinder.

[0009] The reversing valve is used to control the connection between the oil inlet pipeline and the rodless or rod chamber of the working cylinder, and the reversing valve has a Y-type neutral position function.

[0010] The working cylinder is used to control the synchronous extension and retraction of the cutter through the extension and retraction movement of the piston rod;

[0011] The accumulator is simultaneously connected to the first working port of the reversing valve and the rodless chamber of the working cylinder.

[0012] Preferably, it also includes a controllable one-way valve;

[0013] The controllable one-way valve is connected between the first working port of the directional valve and the accumulator, and is used to prevent the pressure oil in the accumulator from flowing to the directional valve, and to conduct when the piston rod of the working cylinder retracts.

[0014] Preferably, the controllable check valve is a hydraulically controlled check valve, and the hydraulic control port of the hydraulically controlled check valve is connected to the second working port of the directional valve.

[0015] Preferably, it also includes a throttle valve and a check valve;

[0016] The throttle valve is connected between the accumulator and the rodless chamber of the working cylinder; the check valve is connected in parallel with the throttle valve and is used to ensure that when the pressurized oil flows out of the accumulator, it only flows through the oil circuit where the throttle valve is located.

[0017] Preferably, it also includes a pressure sensor for detecting the pressure in the rodless chamber of the working cylinder.

[0018] Preferably, it also includes an overflow valve;

[0019] The inlet of the overflow valve is connected to the first working port of the reversing valve, the outlet of the overflow valve is connected to the oil tank, and the overflow pressure of the overflow valve is the rated charging pressure of the accumulator.

[0020] Preferably, multiple working cylinders are provided, and the piston rod of each working cylinder is connected to the roller shaft of the corresponding row of cutters.

[0021] Preferably, the reversing valve is a three-position four-way reversing valve, and when the reversing valve is working in the first position, its oil inlet is connected to its first working oil port and its oil return port is connected to its second working oil port; when the reversing valve is working in the second position, its oil inlet is connected to its second working oil port and its oil return port is connected to its first working oil port.

[0022] Preferably, it also includes an on / off control valve;

[0023] The on / off control valve is connected between the first working port of the directional valve and the rodless chamber of the working cylinder, and is used to control the on / off state of the oil circuit between the two.

[0024] The present invention also provides a baler, including a machine body and a cutter retraction protection hydraulic control system disposed on the machine body, wherein the cutter retraction protection hydraulic control system is specifically the cutter retraction protection hydraulic control system described in any of the above claims.

[0025] The hydraulic control system for cutter retraction protection provided by this invention mainly includes an oil inlet pipe, an oil return pipe, a reversing valve, a working cylinder, and an accumulator. The oil inlet pipe is connected to an oil source or oil pump and is mainly used to provide pressurized oil to introduce it into various components of the system. The oil return pipe is connected to an oil tank and is mainly used to return pressurized oil. The piston rod of the working cylinder is connected to the cutter and is mainly used to control the synchronous extension and retraction of the cutter with the cylinder during operation, thereby realizing the cutter's advance and retraction operations, and thus switching the cutter between the working and non-working positions. The reversing valve is connected between the oil inlet pipe and the working cylinder and is mainly used to control the connection relationship between the oil inlet pipe and the working cylinder, that is, to connect with the rod-side or rodless side of the working cylinder, thereby controlling the working state of the working cylinder and causing the piston rod to extend or retract. The directional control valve has an inlet port, a return port, a first working port, and a second working port. The inlet port is connected to the inlet pipeline, the return port is connected to the return pipeline, the first working port is connected to the rodless chamber of the working cylinder, and the second working port is connected to the rod chamber of the working cylinder. Furthermore, the directional control valve has a Y-type neutral position function to maintain pressure in the working cylinder, ensuring that after reaching the predetermined working pressure, the piston rod is in a floating state and can perform corresponding extension and retraction movements under external force. The accumulator is connected to the first working port of the directional control valve and simultaneously to the rodless chamber of the working cylinder.

[0026] Thus, the hydraulic control system for cutter retraction protection provided by this invention, when the oil inlet line controlled by the reversing valve is connected to the rodless chamber of the working cylinder, the piston rod extends, and the cutter gradually enters the working position. At the same time, the oil inlet line replenishes the accumulator with fluid and charges it. When the pressure in the rodless chamber of the working cylinder reaches the predetermined working pressure, the accumulator also reaches the set pressure, and the reversing valve enters the neutral position to maintain pressure in the working cylinder. At this time, the piston rod of the working cylinder is in a floating state. If hard foreign objects are mixed in with weeds, the piston rod will retract smoothly due to the squeezing action of the foreign objects on the cutter, realizing the cutter retraction. The retraction distance is the retraction displacement of the piston rod. The size of the foreign object stuck in the cutter determines the retraction displacement of the piston rod. At the same time, the pressurized oil in the rodless chamber of the working cylinder is squeezed into the accumulator by the piston rod. After the foreign object passes, the compressed oil in the accumulator flows back to the rodless chamber of the working cylinder, driving the piston rod to extend again, and the cutter returns to the working position. When the directional valve controls the oil inlet line to connect with the rod chamber of the working cylinder, the piston rod retracts, and the cutter gradually enters the non-working position.

[0027] In summary, the cutter retraction protection hydraulic control system provided by this invention utilizes the Y-type neutral position function of the reversing valve to keep the piston rod of the working cylinder in a floating state. Combined with the charging and discharging action between the accumulator and the rodless chamber of the working cylinder, this ensures that the cutter retraction distance matches the size of the foreign object, improving the cutter protection effect. Simultaneously, by rationally selecting and matching the accumulator, setting the accumulator pressure, and setting the initial charging pressure, the initial cutting force of the cutter can be adjusted in real time according to requirements, achieving stepless adjustment of the initial cutting force. Furthermore, by controlling the connection between the oil inlet pipe and the rod-side or rodless chamber of the working cylinder through the reversing valve, the working state of the cutter can be easily switched. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 A schematic diagram of a hydraulic system according to a specific embodiment of the present invention.

[0030] Figure 2 A schematic diagram of a hydraulic system according to another specific embodiment of the present invention.

[0031] in, Figure 1 — Figure 2 middle:

[0032] Oil inlet line—1, oil return line—2, directional valve—3, working cylinder—4, accumulator—5, controllable check valve—6, throttle valve—7, check valve—8, pressure sensor—9, relief valve—10, on / off control valve—11. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please refer to Figure 1 , Figure 1 A schematic diagram of a hydraulic system according to a specific embodiment of the present invention.

[0035] In one specific embodiment of the present invention, the hydraulic control system for cutter retraction protection mainly includes an oil inlet pipe 1, an oil return pipe 2, a reversing valve 3, a working cylinder 4, and an accumulator 5.

[0036] The inlet line 1 is connected to the oil source or oil pump and is mainly used to provide pressurized oil to introduce it into various components within the system. The return line 2 is connected to the oil tank and is mainly used to return the pressurized oil. Generally, the inlet line 1 can be connected to the oil source in the tractor unit, while the return line 2 can be connected to the oil tank in the tractor unit.

[0037] The piston rod of the working cylinder 4 is connected to the cutter. It is mainly used to control the synchronous extension and retraction of the cutter with the piston rod in the cylinder during operation, thereby realizing the cutting and retraction operation of the cutter, and thus realizing the switching of the cutter between the working position and the non-working position.

[0038] The reversing valve 3 is connected between the oil inlet pipe 1 and the working cylinder 4. It is mainly used to control the connection relationship between the oil inlet pipe 1 and the working cylinder 4, that is, to communicate with the rod chamber or rodless chamber of the working cylinder 4, thereby controlling the working state of the working cylinder 4 and causing the piston rod to extend or retract.

[0039] The directional valve 3 has an oil inlet (port P in the diagram), an oil return port (port T in the diagram), a first working port (port A in the diagram), and a second working port (port B in the diagram). The oil inlet is connected to the oil inlet pipe 1, the oil return port is connected to the oil return pipe 2, the first working port is connected to the rodless chamber of the working cylinder 4, and the second working port is connected to the rod chamber of the working cylinder 4. Furthermore, the directional valve 3 also has a Y-type neutral position function to maintain pressure on the working cylinder 4, ensuring that after the working cylinder 4 reaches the predetermined working pressure, the piston rod is in a floating state and can perform corresponding extension and retraction movements when subjected to external forces.

[0040] The accumulator 5 is connected to the first working port of the reversing valve 3, and at the same time connected to the rodless chamber of the working cylinder 4.

[0041] Thus, in the hydraulic control system for cutter retraction protection provided in this embodiment, when the reversing valve 3 controls the oil inlet pipe 1 to connect with the rodless chamber of the working cylinder 4, the piston rod extends and the cutter gradually enters the working position. At the same time, the oil inlet pipe 1 replenishes the accumulator 5 with liquid and charges it. When the pressure in the rodless chamber of the working cylinder 4 reaches the predetermined working pressure, the accumulator 5 also reaches the set pressure, and the reversing valve 3 enters the neutral position to maintain pressure in the working cylinder 4. At this time, the piston rod of the working cylinder 4 is in a floating state. If hard foreign objects are mixed in with the weeds, the piston rod will retract smoothly due to the squeezing action of the foreign objects on the cutter, thus retracting the cutter. The retraction distance is the retraction displacement of the piston rod. The size of the foreign object stuck in the cutter determines the retraction displacement of the piston rod. At the same time, the pressurized oil in the rodless chamber of the working cylinder 4 is squeezed into the accumulator 5 by the piston rod. After the foreign object passes through, the compressed oil in the accumulator 5 flows back to the rodless chamber of the working cylinder 4, driving the piston rod to extend again, and the cutter returns to the working position. When the reversing valve 3 controls the oil inlet pipe 1 to connect with the rod chamber of the working cylinder 4, the piston rod retracts, and the cutter gradually enters the non-working position.

[0042] In summary, the cutter retraction protection hydraulic control system provided in this embodiment utilizes the Y-type neutral position function of the reversing valve 3 to keep the piston rod of the working cylinder 4 in a floating state. Combined with the filling and discharging action between the accumulator 5 and the rodless chamber of the working cylinder 4, this ensures that the cutter retraction distance matches the size of the foreign object, improving the cutter protection effect. Simultaneously, by appropriately selecting and matching the accumulator 5, setting its pressure, and setting the initial filling pressure, the initial cutting force of the cutter can be adjusted in real time according to requirements, achieving stepless adjustment of the initial cutting force. Furthermore, by controlling the connection between the oil inlet pipe 1 and the rod-side or rodless chamber of the working cylinder 4 through the reversing valve 3, the working state switching of the cutter can be easily achieved.

[0043] In one optional embodiment of the directional control valve 3, the directional control valve 3 is specifically a three-position four-way directional control valve 3, and generally adopts a solenoid valve. Specifically, when the directional control valve 3 is working in the first position, its inlet port is connected to its first working port, and its return port is connected to its second working port. At this time, the pressure oil in the inlet pipeline 1 enters the rodless chamber of the working cylinder 4 through the PA port of the directional control valve 3, the piston rod extends, and the accumulator 5 is replenished with fluid and charged. When the directional control valve 3 is working in the second position, its inlet port is connected to its second working port, and its return port is connected to its first working port. At this time, the pressure oil in the inlet pipeline 1 enters the rod chamber of the working cylinder 4 through the PB port of the directional control valve 3, and the piston rod retracts. Of course, the directional control valve 3 also has a third position, namely the neutral position. When the directional control valve 3 is in the working position, it has a Y-type function.

[0044] Considering that the directional valve 3 is a slide valve and cannot keep the working cylinder 4 in a strictly pressure-holding state for a long time, a controllable one-way valve 6 is added in this embodiment. Specifically, the controllable one-way valve 6 is connected between the first working port of the directional valve 3 and the accumulator 5. It is mainly used to realize one-way conduction between the two, and the conduction state is controllable. That is, only pressurized oil is allowed to enter the accumulator 5 after passing through the directional valve 3, and pressurized oil is not allowed to flow out of the accumulator 5 and flow back to the directional valve 3. This ensures that the compressed oil in the accumulator 5 can flow back to the rodless chamber of the working cylinder 4 after it flows out, so that the piston rod can be extended again after being retracted due to the passage of foreign objects, thereby automatically resetting the cutter after it retracts. Since there is no oil loss, the pressure in the rodless chamber of the working cylinder 4 remains basically unchanged.

[0045] Of course, when the reversing valve 3 is in the second working position, the controllable one-way valve 6 is in the conducting state so that when the piston rod retracts, the oil in the rodless chamber of the working cylinder 4 can flow smoothly back to the oil tank through the reversing valve 3. At this time, the accumulator 5 is depressurized and there is no stored pressure. It is not necessary to depressurize when maintaining the pipeline. At the same time, the cutter is in the non-working position, which is mainly suitable for baling some weeds that do not need to be cut.

[0046] Specifically, the controllable check valve 6 is a hydraulically controlled check valve, and its hydraulic port is connected to the second working port of the directional valve 3. With this configuration, when the directional valve 3 is in the first or neutral position, no pressurized oil enters the hydraulic port of the hydraulically controlled check valve, thus maintaining a unidirectional flow. Only when the directional valve 3 is in the second position does pressurized oil enter the hydraulic port, at which point the hydraulically controlled check valve is in a bidirectional flow state.

[0047] Of course, the controllable check valve 6 is not limited to hydraulic check valves; for example, an electrically controlled check valve can also be used.

[0048] like Figure 2 As shown, Figure 2A schematic diagram of a hydraulic system according to another specific embodiment of the present invention.

[0049] In addition, to ensure long-term pressure maintenance in the rodless chamber of the working cylinder 4, this can be achieved not only through the aforementioned controllable one-way valve 6, but also through the on / off control valve 11. Specifically, the on / off control valve 11 is connected between the first working port of the directional valve 3 and the rodless chamber of the working cylinder 4, in the same connection position as the aforementioned controllable one-way valve 6. Simultaneously, the on / off control valve 11 has two ports and two positions. When it is in the first position, both ports are closed, meaning the oil circuit between the directional valve 3 and the working cylinder 4 or accumulator 5 is disconnected. At this time, the oil in the rodless chamber of the working cylinder 4 cannot flow back through the directional valve 3; the oil can only flow between the rodless chamber and the accumulator 5. When it is in the second position, the two ports are interconnected, meaning the oil circuit between the directional valve 3 and the working cylinder 4 or accumulator 5 is unobstructed. At this time, the oil in the rodless chamber of the working cylinder 4 and the oil in the accumulator 5 can be depressurized smoothly.

[0050] Considering that during the cutting process, after the cutter retracts and the foreign object has completely passed through, the cutter should slowly and smoothly return to its original position to reduce the impact on the mechanical structure, a set of one-way throttle valves 7 is added in this embodiment. Specifically, the set of one-way throttle valves 7 mainly includes a throttle valve 7 and a one-way valve 8. The throttle valve 7 is connected between the accumulator 5 and the rodless chamber of the working cylinder 4, while the one-way valve 8 is connected in parallel with the throttle valve 7, and its unidirectional flow direction is from the working cylinder 4 to the accumulator 5. With this configuration, when the reversing valve 3 is in the neutral position, the working cylinder 4 is in the pressure-holding state, and the piston rod is in the floating state, if a foreign object passes through, the piston rod retracts, and the pressurized oil in the rodless chamber is quickly squeezed into the accumulator 5 through the one-way valve 8, realizing the rapid retraction of the cutter. After the foreign object has completely passed through, the piston rod is relaxed, and the compressed oil in the accumulator 5 is automatically released. Since it cannot pass through the one-way valve 8, it can only slowly pass through the throttle valve 7 and then flow back to the rodless chamber of the working cylinder 4, so that the piston rod slowly resets, thereby slowly resetting the cutter.

[0051] To facilitate accurate monitoring of the pressure in the rodless chamber of the working cylinder 4, a pressure sensor 9 is added in this embodiment. Specifically, the detection port of the pressure sensor 9 is connected to the rodless chamber of the working cylinder 4, and also to the first working port of the reversing valve 3 and the port of the accumulator 5. With this configuration, when the pressure in the rodless chamber of the working cylinder 4 reaches the set value, the controller automatically switches the reversing valve 3 from the first position to the neutral position based on the feedback data from the pressure sensor 9, preventing excessive pressure in the cylinder; similarly, it also prevents excessive filling pressure in the accumulator 5.

[0052] Furthermore, to ensure system oil pressure safety, this embodiment also includes an overflow valve 10. Specifically, the inlet of the overflow valve 10 is connected to the first working port of the reversing valve 3, and the outlet of the overflow valve 10 is connected to the oil tank. Simultaneously, the overflow pressure of the overflow valve 10 is the rated charging pressure of the accumulator 5. With this configuration, if the pressure sensor 9 fails, after the accumulator 5 reaches the set pressure, the controller may not be able to switch the reversing valve 3 to the correct position in time, potentially leading to overpressure in the accumulator 5 and damage to components. However, through the overflow action of the overflow valve 10, when the pressure through the first working port of the reversing valve 3 exceeds the overflow pressure, the excess pressurized oil flows back to the oil tank through the overflow valve 10, ensuring that the maximum pressure of the accumulator 5 is maintained at the rated charging pressure.

[0053] Furthermore, considering that in existing technologies, linking all cutters together cannot meet the cutting requirements for different bale lengths, and that all cutters retract when foreign objects pass through, resulting in poor cutting effect and low efficiency, this embodiment addresses this issue by simultaneously configuring multiple working cylinders 4, with the piston rod of each working cylinder 4 connected to the roller shaft of its corresponding row of cutters. With this configuration, the advance and retraction states of each row of cutters are controlled by their respective working cylinders 4, achieving individual control of each row. Therefore, if a foreign object gets stuck on a blade, only the row of cutters corresponding to that blade will automatically retract, while the other rows remain unaffected and continue cutting normally.

[0054] Correspondingly, if multiple working cylinders 4 are provided, then multiple supporting components such as reversing valves 3, accumulators 5, controllable one-way valves 6, pressure sensors 9, and overflow valves 10 can also be provided accordingly, so that one reversing valve 3 controls the working state of one working cylinder 4. This enables the operation of single-row cutter raising (cutting), single-row cutter lowering (cutting), multiple-row cutter raising simultaneously, and multiple-row cutter lowering simultaneously, according to the cutting requirements of the bale length, thereby improving the cutting effect and work efficiency.

[0055] This embodiment also provides a baler, which mainly includes a machine body and a cutter retraction protection hydraulic control system installed on the machine body. The specific contents of the cutter retraction protection hydraulic control system are the same as those mentioned above, and will not be repeated here.

[0056] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A shear blade retraction protection hydraulic control system, characterized by, Including oil inlet pipeline (1), oil return pipeline (2), reversing valve (3), working oil cylinder (4), accumulator (5); The oil inlet of the reversing valve (3) is communicated with the oil inlet pipeline (1), the oil return of the reversing valve (3) is communicated with the oil return pipeline (2), the first working oil port of the reversing valve (3) is communicated with the rodless cavity of the working oil cylinder (4), and the second working oil port of the reversing valve (3) is communicated with the rod cavity of the working oil cylinder (4); The reversing valve (3) is used for controlling the communication of the oil inlet pipeline (1) and the rodless cavity or the rod cavity of the working oil cylinder (4), and the reversing valve (3) has Y-type neutral function; The working oil cylinder (4) is used for controlling the synchronous extension and retraction of the cutter through the extension and retraction movement of the piston rod; The accumulator (5) is communicated with the first working oil port of the reversing valve (3) and the rodless cavity of the working oil cylinder (4) at the same time; Further comprising a controllable check valve (6); The controllable check valve (6) is communicated between the first working oil port of the reversing valve (3) and the accumulator (5), used for preventing the pressure oil in the accumulator (5) from flowing to the reversing valve (3), and conducting when the piston rod of the working oil cylinder (4) retracts; The controllable check valve (6) is a hydraulic check valve, and the hydraulic control oil port of the hydraulic check valve is communicated with the second working oil port of the reversing valve (3); when the reversing valve (3) is in the first position or the neutral position, the hydraulic check valve is one-way conducting; when the reversing valve (3) is in the second position, the hydraulic check valve is bidirectional conducting; Further comprising a throttle valve (7) and a check valve (8); The throttle valve (7) is communicated between the accumulator (5) and the rodless cavity of the working oil cylinder (4); the check valve (8) is connected with the throttle valve (7) in parallel, used for flowing through the oil path where the throttle valve (7) is located when the pressure oil flows out of the accumulator (5); When the reversing valve (3) controls the communication of the oil inlet pipeline (1) and the rodless cavity of the working oil cylinder (4), the piston rod extends, the cutter gradually enters the working position, the oil inlet pipeline (1) charges the accumulator (5), when the pressure of the rodless cavity of the working oil cylinder (4) reaches the predetermined working pressure, the accumulator (5) reaches the set pressure, the reversing valve (3) enters the neutral state, and the pressure of the working oil cylinder (4) is maintained; at this time, the piston rod is in a floating state, if hard foreign matter is mixed in the grass, the piston rod is retracted smoothly through the extrusion of the foreign matter on the cutter, the cutter is retracted, and the retraction distance of the cutter is the retraction displacement of the piston rod, and at the same time, the pressure oil in the rodless cavity of the working oil cylinder (4) is extruded into the accumulator (5) by the piston rod; When the foreign matter passes, the compressed oil liquid in the accumulator (5) flows back to the rodless cavity of the working oil cylinder (4) again, the piston rod is extended again, and the cutter returns to the working position. When the reversing valve (3) controls the oil inlet pipeline (1) to communicate with the rod cavity of the working oil cylinder (4), the piston rod retracts, and the cutter gradually enters the non-working position.

2. The cutter retraction protection hydraulic control system of claim 1, wherein, A pressure sensor (9) for detecting the pressure of the rodless cavity of the working oil cylinder (4) is further included.

3. The cutter retraction protection hydraulic control system of claim 2, wherein, An overflow valve (10) is further included. The oil inlet of the overflow valve (10) communicates with the first working oil port of the reversing valve (3), the oil outlet of the overflow valve (10) communicates with the oil tank, and the overflow pressure of the overflow valve (10) is the rated charging pressure of the accumulator (5).

4. The cutter retraction protection hydraulic control system of claim 1, wherein, A plurality of working oil cylinders (4) are provided, and the piston rod of each working oil cylinder (4) is connected to the roller shaft of the corresponding row of cutters.

5. The cutter retraction protection hydraulic control system of claim 1, wherein, The reversing valve (3) is a three-position four-way reversing valve, and when the reversing valve (3) works in the first position, its oil inlet communicates with its first working oil port, and its oil return port communicates with its second working oil port; when the reversing valve (3) works in the second position, its oil inlet communicates with its second working oil port, and its oil return port communicates with its first working oil port.

6. A baler comprising a machine body and a knife retraction protection hydraulic control system disposed on the machine body, characterized in that, The cutter back-off protection hydraulic control system is specifically the cutter back-off protection hydraulic control system according to any one of claims 1-5.

Images