Control valve group of double-bag-outlet type square bundle bundling machine

Abstract

A control valve set of a double-bag-outlet type square bundle bundling machine comprises an oil inlet valve plate, a three-cylinder reversing valve plate, a two-cylinder reversing valve plate, a middle valve plate, a one-cylinder reversing valve plate and an oil return valve plate which are connected in sequence. The oil inlet valve plate is provided with two oil inlets, an oil return opening T1 and two liquid supplementing openings J and BY, and a first pilot-operated type electro-hydraulic control valve is integrated in the oil inlet valve plate. The oil inlet P2 is communicated with the oil inlet P1 and the liquid supplementing port J or the liquid supplementing port BY through a first pilot-operated type electro-hydraulic control valve; the three reversing valve plates are respectively provided with a pair of working ports; an oil inlet P3 and a second pilot-operated type electro-hydraulic control valve are arranged on the middle valve plate, and the oil inlet P3 is communicated with the third three-position six-way valve or a P port of the first three-position six-way valve and a P port of the second three-position six-way valve through the second pilot-operated type electro-hydraulic control valve; the oil inlet P1 is communicated with a P port of the third three-position six-way valve through the first three-position six-way valve and the second three-position six-way valve which are located in the middle position. The valve group can realize accurate cooperative control of multiple hydraulic cylinders, improves the energy efficiency of the system, inhibits pressure impact, and adapts to the requirements of different working conditions.

Description

Technical Field

[0001] This invention pertains to hydraulic valve assemblies, and specifically relates to a control valve assembly for a double-outlet square baler. Background Technology

[0002] With the deepening of agricultural modernization, balers, as core equipment in the comprehensive utilization of straw and forage harvesting, have a significant impact on agricultural production efficiency and reliability. In recent years, driven by agricultural mechanization policies and straw comprehensive utilization policies, the baler industry has experienced significant development.

[0003] Currently, most square balers on the market adopt a single compression chamber structure, and their hydraulic systems mainly fall into the following two technical categories: One approach is a single-pump, multi-valve distributed control system, which uses a single hydraulic pump with multiple independent control valves to drive each actuator. While this solution is simple in structure, it suffers from poor coordination between actuators, large system pressure fluctuations, and significant energy loss. Parallel installation of multiple valves occupies a large space, involves complex piping layouts, and has a high system failure rate.

[0004] The second type is the sequence valve control system, which relies on mechanical cams or hydraulic sequence valves to achieve a fixed sequence of actuator movements. This type of system has an unadjustable operating flow, slow response, and limited operational efficiency. It also exhibits poor adaptability to varying densities of silage and haystack materials, lacks system rigidity, is difficult to debug and maintain, and has high operating costs.

[0005] The control valve assembly of the innovative double-outlet square baler requires a high degree of coordination between multiple hydraulic cylinders (including silage and yellow silage material pushing cylinders, compaction cylinders, and bale exit cylinders) and the netting mechanism.

[0006] The double-outlet square baler consists of two compression chambers. When silage or haystack material enters, the silage / haystack material pushing cylinder pushes the material to the left or right; then, the silage / haystack material compaction cylinder compacts the material downwards; finally, the silage / haystack material exit cylinder pushes it out; and finally, the wire wrapping valve assembly wraps the bales. When the density of the silage / haystack material is high, the bales from both sides may exit almost simultaneously.

[0007] Traditional hydraulic control systems mainly face the following technical challenges: In terms of synchronous control, multiple hydraulic cylinders need to complete high-precision timing coordination in a very short time. The left and right distributing actions of the silage and hay silage pushing cylinders must be closely coordinated with the downward pressing action of the compaction cylinders; otherwise, it is easy to cause the silage and hay silage materials to jam or be unevenly compressed.

[0008] In terms of adaptability to working conditions, different crop types and humidity conditions lead to significant differences in the compression characteristics of silage and hay. Control systems with fixed parameters are unlikely to achieve optimal compression results, thus affecting bale quality and operational efficiency.

[0009] Patent searches revealed that while some hydraulic control solutions for balers exist in the prior art—such as using dual pumps to supply oil separately to improve energy efficiency—these solutions suffer from complex system structures and high costs. Additionally, sequential control systems based on pressure compensation can improve motion coordination to some extent, but they still cannot meet the high-precision requirements of multi-cylinder coordinated control for double-outlet square balers.

[0010] Therefore, there is an urgent need to develop a new type of hydraulic valve assembly system capable of precise coordinated control of multiple hydraulic cylinders, improving system energy efficiency, suppressing pressure shocks, and adapting to the requirements of different operating conditions. This valve assembly should possess characteristics such as high integration, precise control, reliable operation, and ease of installation and maintenance to support the high efficiency and reliability requirements of double-outlet square balers. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a control valve group for a double-outlet square baler that can achieve precise coordinated control of multiple hydraulic cylinders, improve system energy efficiency, suppress pressure shock, and adapt to different working conditions.

[0012] To achieve the above objectives, the present invention adopts the following technical solution: A control valve group for a double-outlet square baler includes an oil inlet valve plate, a three-cylinder reversing valve plate, a two-cylinder reversing valve plate, an intermediate valve plate, a one-cylinder reversing valve plate, and an oil return valve plate connected in sequence. The oil inlet valve plate is provided with two oil inlets P1 and P2, an oil return port T1, and two replenishment ports J and BY. It integrates a first pilot-operated electro-hydraulic control valve. The oil inlet P1 is connected to the main oil circuit located between each valve plate. The oil inlet P2 is connected to the main oil circuit, replenishment port J, or oil return port T1 through the first pilot-operated electro-hydraulic control valve. It is used to connect an external auxiliary pump to achieve the merging with the main pump or to replenish multiple pairs of working cylinders. The three-cylinder reversing valve plate is provided with a pair of working oil ports A3 and B3, and its interior is integrated with a first three-position six-way valve for controlling the reversal of its oil circuit, which is used to connect and control the rodless chamber of two material discharge cylinders connected in series. The two-cylinder reversing valve plate is provided with a pair of working oil ports A2 and B2, and its interior is integrated with a second three-position six-way valve for controlling the reversal of its oil circuit, which is used to connect and control the rodless chamber of two material compaction cylinders connected in series. The cylinder reversing valve plate is provided with a pair of working ports A1 and B1, and its interior is integrated with a third three-position six-way valve for controlling the oil circuit reversal, which is used to connect and control the outer oil chambers of two material pushing cylinders connected in series. The intermediate valve plate is provided with an oil inlet P3 and has a second pilot-operated electro-hydraulic control valve integrated inside. The oil inlet P3 is connected to the P port of the third three-position six-way valve or the first and second three-position six-way valves through the second pilot-operated electro-hydraulic control valve. It is used to connect to the third pump and control the oil circuit direction of the oil inlet P3. The P ports of the first and second three-position six-way valves are respectively connected to the main oil circuit through internal oil passages. When the first, second, and third three-position six-way valves are in the middle position, the main oil circuit passes through each valve plate in sequence and is connected to the return oil port T1 through the return oil circuit located between each valve plate; the P port of the third three-position six-way valve is connected to the main oil circuit to realize the three-pump combined oil supply during startup.

[0013] As a further preferred embodiment, the first pilot-operated electro-hydraulic control valve is a hydraulically controlled three-position four-way valve, with its P port connected to the oil inlet P2 through an internal oil passage, its T port connected to the oil return port T1 through an internal oil passage, its A port connected to the main oil circuit, and its B port connected to the replenishment port J provided on the oil inlet valve plate, so as to facilitate the replenishment of liquid to the compaction cylinder or the bag outlet cylinder.

[0014] As a further preferred embodiment, the oil inlet valve plate is also provided with a first two-position three-way solenoid valve YV1 and a second two-position three-way solenoid valve YV2. The control ports at both ends of the first pilot-operated electro-hydraulic control valve are respectively connected to the A ports of the first two-position three-way solenoid valve YV1 and the second two-position three-way solenoid valve YV2. The P and T ports of the first two-position three-way solenoid valve YV1 and the second two-position three-way solenoid valve YV2 are respectively connected to the pilot control oil port X and the leakage oil port Y provided on the return oil valve plate through the internal control oil circuit, so as to control the switching of the first pilot-operated electro-hydraulic control valve.

[0015] As a further preferred embodiment, the oil inlet valve plate is also provided with a pilot pressure control unit, which includes a pressure reducing valve and a two-position two-way solenoid valve connected in sequence between the main oil circuit and the replenishment port BY. The two-position two-way solenoid valve is a bidirectional check valve, used to suppress the pressure shock of the system pressure and the pressure feedback from the oil cylinder.

[0016] As a further preferred embodiment, the three-cylinder directional valve plate is also equipped with a third two-position three-way solenoid valve YV3 and a fourth two-position three-way solenoid valve YV4. The first three-position six-way valve is a hydraulically controlled directional valve, and its two control ports are respectively connected to the A ports of the third two-position three-way solenoid valve YV3 and the fourth two-position three-way solenoid valve YV4. The P and T ports of the third two-position three-way solenoid valve YV3 and the fourth two-position three-way solenoid valve YV4 are respectively connected to the pilot control oil port X and the leakage oil port Y provided on the return oil valve plate through the internal control oil circuit, so as to control the directional switching of the first three-position six-way valve.

[0017] As a further preferred embodiment, the two-cylinder reversing valve plate is also equipped with a fifth two-position three-way solenoid valve YV5 and a sixth two-position three-way solenoid valve YV6. The second three-position six-way valve is a hydraulically controlled reversing valve, and its two ends of the control ports are respectively connected to the A ports of the fifth two-position three-way solenoid valve YV5 and the sixth two-position three-way solenoid valve YV6. The P and T ports of the fifth two-position three-way solenoid valve YV5 and the sixth two-position three-way solenoid valve YV6 are respectively connected to the pilot control oil port X and the leakage oil port Y provided on the return oil valve plate through the internal control oil circuit, so as to control the reversing of the second three-position six-way valve.

[0018] As a further preferred embodiment, the cylinder reversing valve plate is also equipped with an eighth 2nd position three-way solenoid valve YV8 and a ninth 2nd position three-way solenoid valve YV9. The third 3rd position six-way valve is a hydraulically controlled reversing valve, and its two control ports are respectively connected to the A ports of the eighth 2nd position three-way solenoid valve YV8 and the ninth 2nd position three-way solenoid valve YV9. The P and T ports of the eighth 2nd position three-way solenoid valve YV8 and the ninth 2nd position three-way solenoid valve YV9 are respectively connected to the pilot control oil port X and the leakage oil port Y provided on the return oil valve plate through the internal control oil circuit, so as to control the reversing of the third 3rd position six-way valve.

[0019] As a further preferred embodiment, the intermediate valve plate is also provided with a 72-position three-way solenoid valve YV7. The second pilot-operated electro-hydraulic control valve is a 2-position three-way hydraulic directional valve. The control port at one end of the valve is connected to port A of the 72-position three-way solenoid valve YV7. Ports P and T of the 72-position three-way solenoid valve YV7 are respectively connected to the pilot control oil port X and leakage oil port Y provided on the return oil valve plate through the internal control oil circuit, so as to control the directional switching of the second pilot-operated electro-hydraulic control valve.

[0020] As a further preferred embodiment, the return valve plate integrates a second relief valve and a check valve. The check valve is located in the control oil circuit corresponding to the pilot control port X to prevent oil from flowing back to the pilot pump. The two ends of the second relief valve are respectively connected to the pilot control port X and the leakage port Y to limit the maximum pressure of the control oil circuit and prevent excessive pressure from damaging the two-position three-way solenoid valve.

[0021] As a further preferred embodiment, the cylinder reversing valve plate also integrates a first relief valve and a third relief valve. The two ends of the first relief valve and the third relief valve are respectively connected to the working ports B1 and A1 and the return port T1 through internal oil passages, which are used to limit the maximum liquid outlet pressure of the working ports A1 and B1.

[0022] The beneficial effects of this invention are as follows: 1. This invention utilizes a segmented integrated design to compactly combine multiple functional valve plates, significantly reducing external connecting pipelines and lowering leakage risk and failure rate. Through the oil inlet P3 on the intermediate valve plate, which connects to the P port of the third three-position six-way valve or the first and second three-position six-way valves via the internally integrated second pilot-operated electro-hydraulic control valve, precise coordinated control of multiple pairs of working cylinders can be achieved during operation, improving system response speed and work efficiency, and adapting to different operating conditions.

[0023] 2. Through the oil inlet P2 located on the oil inlet valve plate, it is connected to the main oil circuit, the replenishment port J or the return port T1 via the internally integrated first pilot electro-hydraulic control valve. It can be connected to an external auxiliary pump to achieve the merging with the main pump or to replenish the fluid of multiple pairs of working cylinders, thereby ensuring the reliable operation of multiple pairs of working cylinders.

[0024] 3. When the first, second, and third three-position six-way valves are in the neutral position, the main oil circuit passes through each valve plate in sequence and is connected to the return oil port T1 through the return oil circuit located between each valve plate; this allows the hydraulic oil entering through the three inlets to return directly to the oil tank through the main and return oil circuits, instead of being unloaded through the relief valve, thus effectively reducing system energy loss and heat generation; through the P port of the third three-position six-way valve connected to the main oil circuit, the three pumps can be combined to supply oil during startup, thereby accelerating the startup speed of the material pushing cylinder and improving working efficiency.

[0025] 4. The pilot pressure control unit integrated on the oil inlet valve plate effectively reduces pressure loss and shock, enhancing system reliability and service life. This valve assembly boasts advantages such as high integration, precise control, reliable operation, and ease of installation and maintenance, meeting the high efficiency and reliability requirements of double-outlet square balers. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the control valve assembly of the present invention.

[0027] Figure 2 yes Figure 1 Top view.

[0028] Figure 3 yes Figure 1 A bottom view.

[0029] Figure 4 yes Figure 1 The left view.

[0030] Figure 5 yes Figure 1 The right view.

[0031] Figure 6 This is a schematic diagram of the hydraulic system of the present invention.

[0032] In the diagram: 1. Inlet valve plate; 2. Three-cylinder directional valve plate; 3. Baffle plate; 4. Two-cylinder directional valve plate; 5. Intermediate valve plate; 6. One-cylinder directional valve plate; 7. Return valve plate; 8. First relief valve; 9. Second relief valve; 10. Check valve; 11. Third relief valve; 12. Auxiliary relief valve; 13. Pressure reducing valve; 14. Two-position two-way solenoid valve; 15. Main relief valve; 16. First pilot-operated electro-hydraulic control valve; 17. First three-position six-way valve; 18. Second three-position six-way valve; 19. Second pilot-operated electro-hydraulic control valve. Hydraulic control valve 19, third-position six-way valve 20, main oil circuit 21, return oil circuit 22, first-position two-way three-way solenoid valve YV1, second-position two-way three-way solenoid valve YV2, third-position two-way three-way solenoid valve YV3, fourth-position two-way three-way solenoid valve YV4, fifth-position two-way three-way solenoid valve YV5, sixth-position two-way three-way solenoid valve YV6, seventh-position two-way three-way solenoid valve YV7, eighth-position two-way three-way solenoid valve YV8, and ninth-position two-way three-way solenoid valve YV9. 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] like Figure 1-6 As shown, the present invention relates to a control valve assembly for a double-outlet square baler, comprising an inlet valve plate 1, a three-cylinder reversing valve plate 2, a partition plate 3, a two-cylinder reversing valve plate 4, an intermediate valve plate 5, a one-cylinder reversing valve plate 6, and a return valve plate 7 connected in sequence by bolts. A main oil passage 21 and a return oil passage 22, parallel to each other, are provided between the valve plates.

[0035] The oil inlet valve plate 1 is provided with two oil inlets P1 and P2, an oil return port T1, and two replenishment ports J and BY. It integrates a first pilot-operated electro-hydraulic control valve 16. The oil inlet P1 is connected to the main oil circuit 21 through an internal oil passage. The oil inlet P2 is connected to the main oil circuit 21, replenishment port J, or oil return port T1 through the first pilot-operated electro-hydraulic control valve 16. It is used to connect an external auxiliary pump to achieve the merging with the main pump or to replenish multiple pairs of working cylinders.

[0036] The first pilot-operated electro-hydraulic control valve 16 is a hydraulically controlled three-position four-way valve. Its P port is connected to the oil inlet P2 through an internal oil passage, its T port is connected to the oil return port T1 through an internal oil passage, its A port is connected to the main oil circuit 21 through an internal oil passage, and its B port is connected to the replenishment port J provided on the oil inlet valve plate 1, so as to realize the replenishment of liquid to the compaction cylinder or the bag outlet cylinder.

[0037] The inlet valve plate 1 also integrates a pilot pressure control unit, which includes a pressure reducing valve 13 and a two-position two-way solenoid valve 14 connected in sequence between the main oil circuit 21 and the replenishment port BY. The two-position two-way solenoid valve 14 is a bidirectional check valve type, used to suppress the pressure shock of the system pressure and the pressure feedback from the oil cylinder.

[0038] The inlet valve plate 1 also integrates a first two-position three-way solenoid valve YV1 and a second two-position three-way solenoid valve YV2. The control ports at both ends of the first pilot-operated electro-hydraulic control valve 16 are respectively connected to the A ports of the first two-position three-way solenoid valve YV1 and the second two-position three-way solenoid valve YV2. The P and T ports of the first two-position three-way solenoid valve YV1 and the second two-position three-way solenoid valve YV2 are respectively connected to the pilot control oil port X and the leakage oil port Y provided on the return valve plate 7 through internal control oil circuits, so as to control the switching of the first pilot-operated electro-hydraulic control valve 16. The control oil port X and the leakage oil port Y are respectively used to connect the pilot pump and the oil tank.

[0039] A main relief valve 15 and a secondary relief valve 12 are also installed inside the inlet valve plate 1. The main relief valve 15 is connected between the main oil circuit 21 and the return port T1 through an internal oil passage, and is used to limit the maximum working pressure of the system to prevent damage to the hydraulic system and related actuators due to excessive pressure. The secondary relief valve 12 is connected between the inlet port P2 and the return port T1 through an internal oil passage, and is used to stabilize the input pressure of the oil circuit at the inlet port P2 to prevent it from becoming too high. At the same time, it ensures that the oil pressure delivered to the replenishment port J through the first pilot-operated electro-hydraulic control valve 16 is within a safe range, and can be connected to an external valve group to realize additional functions.

[0040] The three-cylinder reversing valve plate 2 is provided with a pair of working oil ports A3 and B3. It integrates a first three-position six-way valve 17 that controls the reversal of its oil circuit. Its P port and T port are respectively connected to the main oil circuit 21 and the return oil circuit 22 through internal oil passages. Its A and B ports are respectively connected to the working oil ports A3 and B3 through internal oil passages. It is used to connect and control the rodless chamber of two interconnected material discharge cylinders.

[0041] The three-cylinder reversing valve plate 2 is also equipped with a third two-position three-way solenoid valve YV3 and a fourth two-position three-way solenoid valve YV4. The first three-position six-way valve 17 is a hydraulically controlled reversing valve. The control ports at both ends of the valve are connected to the A ports of the third two-position three-way solenoid valve YV3 and the fourth two-position three-way solenoid valve YV4, respectively. The P and T ports of the third two-position three-way solenoid valve YV3 and the fourth two-position three-way solenoid valve YV4 are connected to the pilot control oil port X and the leakage oil port Y through the internal control oil circuit, respectively, so as to control the reversing of the first three-position six-way valve 17.

[0042] When the first three-position six-way valve 17 is in the neutral position, its P, T, A, and B ports are respectively closed, while its P' and C ports are interconnected; when the first three-position six-way valve 17 is in the upper position, its P and B ports are interconnected, its T and A ports are interconnected, while its P' and C ports are respectively closed; when the first three-position six-way valve 17 is in the lower position, its P and A ports are interconnected, its T and B ports are interconnected, while its P' and C ports are respectively closed.

[0043] The two-cylinder reversing valve plate 4 is equipped with a pair of working oil ports A2 and B2, which integrate a second three-position six-way valve 18 for controlling the reversal of its oil circuit. Its P port and T port are respectively connected to the main oil circuit 21 and the return oil circuit 22 through internal oil passages, while its A and B ports are respectively connected to the working oil ports A2 and B2 through internal oil passages. This valve is used to connect and control the rodless chambers of the two interconnected material compaction cylinders. The internal structure of the second three-position six-way valve 18 is the same as that of the first three-position six-way valve 17.

[0044] The two-cylinder reversing valve plate 4 is also equipped with a fifth two-position three-way solenoid valve YV5 and a sixth two-position three-way solenoid valve YV6. The second three-position six-way valve 18 is a hydraulically controlled reversing valve, and its two control ports are respectively connected to the A ports of the fifth two-position three-way solenoid valve YV5 and the sixth two-position three-way solenoid valve YV6. The P and T ports of the fifth two-position three-way solenoid valve YV5 and the sixth two-position three-way solenoid valve YV6 are respectively connected to the pilot control oil port X and the leakage oil port Y through internal control oil circuits to control the reversing of the second three-position six-way valve 18.

[0045] The cylinder reversing valve plate 6 is provided with a pair of working ports A1 and B1, which integrate a third three-position six-way valve 20 to control the oil circuit reversal. The P and P' ports of the third three-position six-way valve 20 are interconnected, and its A and B ports are respectively connected to the working oil ports A1 and B1 through internal oil passages. Its T port is connected to the return oil port T1 through an internal oil passage, which is used to connect and control the outer oil chambers of two interconnected material pushing cylinders.

[0046] The cylinder reversing valve plate 6 is also equipped with an eighth two-position three-way solenoid valve YV8 and a ninth two-position three-way solenoid valve YV9. The third three-position six-way valve 20 is a hydraulically controlled reversing valve and has the same internal structure as the first three-position six-way valve 17. Its two control ports are respectively connected to the A ports of the eighth two-position three-way solenoid valve YV8 and the ninth two-position three-way solenoid valve YV9. The P and T ports of the eighth two-position three-way solenoid valve YV8 and the ninth two-position three-way solenoid valve YV9 are respectively connected to the pilot control oil port X and the leakage oil port Y through internal control oil circuits to control the reversing of the third three-position six-way valve 20.

[0047] The cylinder reversing valve plate 6 also integrates a first overflow valve 8 and a third overflow valve 11. The two ends of the first overflow valve 8 and the third overflow valve 11 are respectively connected to the working port B1, A1 and the return port T1 through internal oil passages, which are used to limit the maximum liquid outlet pressure of the working port A1 and B1.

[0048] The intermediate valve plate 5 is provided with an oil inlet P3 and integrates a second pilot-operated electro-hydraulic control valve 19. The oil inlet P3 is connected to the third three-position six-way valve 20 or the P port of the first and second three-position six-way valves through the second pilot-operated electro-hydraulic control valve 19, for connecting to a third pump and controlling the oil circuit direction of the oil inlet P3. The P ports of the first and second three-position six-way valves are respectively connected to the main oil circuit 21 through internal oil passages.

[0049] The intermediate valve plate 5 is also equipped with a 72-position three-way solenoid valve YV7. The second pilot-operated electro-hydraulic control valve 19 is a 2-position three-way hydraulic control directional valve. One of its control ports is connected to port A of the 72-position three-way solenoid valve YV7. The P and T ports of the 72-position three-way solenoid valve YV7 are respectively connected to the pilot control oil port X and the leakage oil port Y through the internal control oil circuit, so as to control the directional switching of the second pilot-operated electro-hydraulic control valve 19.

[0050] When the second pilot-operated electro-hydraulic control valve 19 is in the upper position, its P port is connected to its A port and its T port is closed; when it is in the lower position, its P port is connected to its T port and its A port is closed. The P port of the second pilot-operated electro-hydraulic control valve 19 is connected to the oil inlet P3 through an internal oil passage, its A port is connected to the P and P' ports of the third three-position six-way valve 20, and its T port is connected to the P port of the first and second three-position six-way valves.

[0051] When the first, second, and third three-position six-way valves are in the middle position, the main oil circuit 21 passes through each valve plate in sequence and is connected to the return oil port T1 through the internal oil passage and the return oil circuit 22; the P port of the third three-position six-way valve is connected to the main oil circuit to realize the three-pump combined oil supply during startup.

[0052] The return valve plate 7 integrates a second relief valve 9 and a one-way valve 10. The one-way valve 10 is located in the control oil circuit corresponding to the pilot control port X, and the oil inlet end corresponds to the pilot control port X. It is used to prevent oil from flowing back to the pilot pump. The two ends of the second relief valve 9 are respectively connected to the pilot control port X and the leakage port Y through the internal control oil passage. It is used to limit the maximum pressure of the control oil circuit and prevent the two-position three-way solenoid valve from being damaged by excessive pressure.

[0053] The return valve plate 7 is also provided with return ports T2 and T3. The C port of the third three-position six-way valve 20 is connected to the return ports T2 and T3 through internal oil passages, and is connected to the return port T1 through internal oil passages.

[0054] During operation, inlets P1, P2, and P3 are connected to the main hydraulic pump, auxiliary hydraulic pump, and third pump, respectively, and hydraulic oil enters the system through inlets P1, P2, and P3. When the three-cylinder directional valve plate 2, the two-cylinder directional valve plate 4, and the one-cylinder directional valve plate 6 are all in the neutral position, the hydraulic oil returns directly to the oil tank through return ports T1, T2, and T3, instead of being unloaded through the relief valve, effectively reducing system energy loss and heat generation.

[0055] Pilot control port X connects to the pilot pump outlet. Working ports A1 and B1 connect to the outer working chambers of two material pushing cylinders, respectively. The inner working chambers of the two material pushing cylinders are connected in series via oil pipes, which are then connected to the replenishment port BY via pipelines. Working ports A2 and B2 connect to the rodless chambers of two material compaction cylinders, respectively. The rod chambers of the two material compaction cylinders are connected in series. Working ports A3 and B3 connect to the rodless chambers of two material discharge cylinders, respectively. The rod chambers of the two material discharge cylinders are connected in series.

[0056] When the input pressure or system pressure at inlet P1 exceeds the set value of the main relief valve 15, the main relief valve 15 will overflow and unload. When the input pressure at inlet P2 exceeds the set value of the auxiliary relief valve 12, the auxiliary relief valve 12 will control the unloading. The pressure unloading method at inlet P3 depends on the working state of the third three-position six-way valve 20 in the cylinder reversing valve plate 6: when the third three-position six-way valve 20 reverses, unloading is achieved through the first relief valve 8 or the third relief valve 11 on the valve plate; when the third three-position six-way valve 20 is in the neutral position, and at the same time the intermediate valve plate 5 reverses to the lower position and the first or second three-position six-way valve reverses, unloading is achieved through the main relief valve 15.

[0057] The specific working principle is as follows: 1. After the double-outlet square baler is started, when the detection device on the baler detects that the weight of the silage or hay is up to standard, it immediately sends a feedback signal to the eighth two-position three-way solenoid valve YV8 or the ninth two-position three-way solenoid valve YV9 on the first cylinder reversing valve plate 6, causing the eighth two-position three-way solenoid valve YV8 or the ninth two-position three-way solenoid valve YV9 to switch to the left position. The hydraulic oil output by the pilot pump enters the control port of one end of the third three-position six-way valve 20 through the pilot control oil port X, causing the third three-position six-way valve 20 to switch to the lower or upper position. At this time, all the oil entering through the oil inlets P1, P2 and P3 reaches the third three-position six-way valve 20, and enters the material pushing cylinder on the right or left side through the working port A1 or B1, causing a pair of material pushing cylinders to operate simultaneously to push the silage or hay into the left or right compression chamber.

[0058] When the material pushing cylinder pushes the material into position, the position sensor on the baler sends a feedback signal to the 72-position three-way solenoid valve YV7 on the intermediate valve plate 5 and the 62-position three-way solenoid valve YV6 or the 52-position three-way solenoid valve YV5 on the two-cylinder reversing valve plate 4. This causes the 72-position three-way solenoid valve YV7 and the 62-position three-way solenoid valve YV6 or the 52-position three-way solenoid valve YV5 to switch to the left position. This causes the hydraulic oil output by the pilot pump to enter the control port of the second pilot electro-hydraulic control valve 19 and the control port of one end of the second three-position six-way valve 18 through the pilot control oil port X. This causes the second pilot electro-hydraulic control valve 19 to switch to the lower position and the second three-position six-way valve 18 to switch to the upper or lower position. At this time, the oil entering through the oil inlets P1, P2, and P3 simultaneously reaches the second three-position six-way valve 18 and enters the rodless chamber of the material compaction cylinder on the left or right side through the working port B2 or A2, causing the material compaction cylinder on the left or right side to compact downwards.

[0059] When the material compaction cylinder on the left or right side extends to the position of the corresponding position sensor, the position sensor feeds back a signal to the fourth two-position three-way solenoid valve YV4 or the third two-position three-way solenoid valve YV3 on the three-cylinder reversing valve plate 2, causing the fourth two-position three-way solenoid valve YV4 or the third two-position three-way solenoid valve YV3 to switch to the left position. The hydraulic oil output by the pilot pump enters the control port of one end of the first three-position six-way valve 17 through the pilot control oil port X, causing the first three-position six-way valve 17 to switch to the upper or lower position, and at the same time switching the second three-position six-way valve 18 to the middle position. At this time, the oil entering from the oil inlets P1, P2, and P3 enters the rodless chamber of the material discharge cylinder on the left or right side through the first three-position six-way valve 17 and the working port B3 or A3, causing the material discharge cylinder on the left or right side to push the square bundle laterally to the wrapping device on one side.

[0060] 2. If the baling cylinder corresponding to the compression chamber on one side is working, and the detection device on the baler detects that the weight of the silage or hay silage material meets the standard, a feedback signal is sent to the eighth or ninth two-position three-way solenoid valve in the first cylinder reversing valve plate 6, which was not working last time. This causes the third three-position six-way valve 20 to switch to the opposite position of the last working position. At this time, the oil entering through the oil inlet P3 reaches the third three-position six-way valve 20 and enters the material pushing cylinder through the working port A1 or B1, causing a pair of material pushing cylinders to operate simultaneously and push the material into the compression chamber on the other side.

[0061] When the material pushing cylinder pushes the material into position and the previously working bagging cylinder completes the bagging action, the two position sensors send feedback signals to the fifth or sixth two-position three-way solenoid valve in the two-cylinder reversing valve plate 4, which was not working last time, and the seventh two-position three-way solenoid valve YV7 on the intermediate valve plate 5. At this time, the hydraulic oil output by the pilot pump enters the control port of the second three-position six-way valve 18 and the second pilot electro-hydraulic control valve 19 through the pilot control oil port X, respectively, so that the second pilot electro-hydraulic control valve 19 is reversed to the second working position and the second three-position six-way valve 18 is reversed to the upper or lower position. At this time, the oil entering through the oil inlets P1, P2, and P3 simultaneously reaches the second three-position six-way valve 18 and enters the rodless chamber of the corresponding material compaction cylinder through the working port B2 or A2, so that the corresponding material compaction cylinder is compacted downward.

[0062] When the compaction cylinder reaches the position sensor position, the position sensor feeds back a signal to the third or fourth two-position three-way solenoid valve in the three-cylinder reversing valve plate 2, which was not working last time. This causes the first three-position six-way valve 17 to switch to the opposite position corresponding to the last working position, and at the same time, the second three-position six-way valve 18 is switched to the middle position. At this time, the oil entering from the oil inlets P1, P2, and P3 enters the rodless chamber of the material discharge cylinder corresponding to the compression chamber on the other side through the first three-position six-way valve 17 and the working port B3 or A3. This causes the material discharge cylinder to be pushed out laterally to the corresponding side of the wrapping device, thereby achieving the purpose of alternating bale discharge by the baler.

[0063] 3. When the system load is high, the second two-position three-way solenoid valve YV2 is energized and reversed, causing the first pilot-operated electro-hydraulic control valve 16 to switch to the right position. This allows the oil inlet P2 to return to the oil tank through the first pilot-operated electro-hydraulic control valve 16 and the return port T1, thus cutting off the auxiliary pump's oil supply to ensure priority supply to the main pump, thereby achieving the goal of "high load, low flow".

[0064] 4. When it is necessary to replenish the compaction cylinder or the discharge cylinder, the first two-position three-way solenoid valve YV1 is energized and reversed, so that the first pilot-operated electro-hydraulic control valve 16 moves to the left position, so that the oil inlet P2 reaches the replenishment port J through the first pilot-operated electro-hydraulic control valve 16, and reaches the series oil circuit between the two material compaction cylinders or material discharge cylinders through the single-acting valve group connected to the replenishment port J, thereby realizing the replenishment.

[0065] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A control valve assembly for a double-outlet square baler, characterized in that: It includes an inlet valve plate, a three-cylinder reversing valve plate, a two-cylinder reversing valve plate, an intermediate valve plate, a one-cylinder reversing valve plate, and a return valve plate connected in sequence. The oil inlet valve plate is provided with two oil inlets P1 and P2, an oil return port T1, and two replenishment ports J and BY. It integrates a first pilot-operated electro-hydraulic control valve. The oil inlet P1 is connected to the main oil circuit located between each valve plate. The oil inlet P2 is connected to the main oil circuit, replenishment port J, or oil return port T1 through the first pilot-operated electro-hydraulic control valve. It is used to connect an external auxiliary pump to achieve the merging with the main pump or to replenish multiple pairs of working cylinders. The three-cylinder reversing valve plate is provided with a pair of working oil ports A3 and B3, and its interior is integrated with a first three-position six-way valve for controlling the reversal of its oil circuit, which is used to connect and control the rodless chamber of two material discharge cylinders connected in series. The two-cylinder reversing valve plate is provided with a pair of working oil ports A2 and B2, and its interior is integrated with a second three-position six-way valve for controlling the reversal of its oil circuit, which is used to connect and control the rodless chamber of two material compaction cylinders connected in series. The cylinder reversing valve plate is provided with a pair of working ports A1 and B1, and its interior is integrated with a third three-position six-way valve for controlling the oil circuit reversal, which is used to connect and control the outer oil chambers of two material pushing cylinders connected in series. The intermediate valve plate is provided with an oil inlet P3 and has a second pilot-operated electro-hydraulic control valve integrated inside. The oil inlet P3 is connected to the P port of the third three-position six-way valve or the first and second three-position six-way valves through the second pilot-operated electro-hydraulic control valve. It is used to connect to the third pump and control the oil circuit direction of the oil inlet P3. The P ports of the first and second three-position six-way valves are respectively connected to the main oil circuit through internal oil passages. When the first, second, and third three-position six-way valves are in the middle position, the main oil circuit passes through each valve plate in sequence and is connected to the return oil port T1 through the return oil circuit located between each valve plate; the P port of the third three-position six-way valve is connected to the main oil circuit to realize the three-pump combined oil supply during startup.

2. The control valve assembly of a double-outlet square baler according to claim 1, characterized in that: The first pilot-operated electro-hydraulic control valve is a hydraulically controlled three-position four-way valve. Its P port is connected to the oil inlet P2 through an internal oil passage, its T port is connected to the oil return port T1 through an internal oil passage, its A port is connected to the main oil circuit, and its B port is connected to the replenishment port J, so as to facilitate the replenishment of liquid to the compaction cylinder or the bag outlet cylinder.

3. The control valve assembly of a double-outlet square baler according to claim 2, characterized in that: The inlet valve plate is also equipped with a first two-position three-way solenoid valve YV1 and a second two-position three-way solenoid valve YV2. The control ports at both ends of the first pilot-operated electro-hydraulic control valve are respectively connected to the A ports of the first two-position three-way solenoid valve YV1 and the second two-position three-way solenoid valve YV2. The P and T ports of the first two-position three-way solenoid valve YV1 and the second two-position three-way solenoid valve YV2 are respectively connected to the pilot control oil port X and the leakage oil port Y provided on the return valve plate through the internal control oil circuit, so as to control the switching of the first pilot-operated electro-hydraulic control valve.

4. The control valve assembly of a double-outlet square baler according to claim 1, characterized in that: The oil inlet valve plate is also equipped with a pilot pressure control unit, which includes a pressure reducing valve and a two-position two-way solenoid valve connected in sequence between the main oil circuit and the replenishment port BY. The two-position two-way solenoid valve is a bidirectional check valve, used to suppress the pressure shock of the system pressure and the pressure feedback from the oil cylinder.

5. The control valve assembly of a double-outlet square baler according to claim 1, characterized in that: The three-cylinder reversing valve plate is also equipped with a third two-position three-way solenoid valve YV3 and a fourth two-position three-way solenoid valve YV4. The first three-position six-way valve is a hydraulically controlled reversing valve. The control ports at both ends of the valve are connected to the A ports of the third two-position three-way solenoid valve YV3 and the fourth two-position three-way solenoid valve YV4, respectively. The P and T ports of the third two-position three-way solenoid valve YV3 and the fourth two-position three-way solenoid valve YV4 are connected to the pilot control oil port X and the leakage oil port Y on the return oil valve plate through the internal control oil circuit, so as to control the reversing of the first three-position six-way valve.

6. The control valve assembly of a double-outlet square baler according to claim 5, characterized in that: The two-cylinder reversing valve plate is also equipped with a fifth two-position three-way solenoid valve YV5 and a sixth two-position three-way solenoid valve YV6. The second three-position six-way valve is a hydraulically controlled reversing valve. The control ports at both ends of the valve are connected to the A ports of the fifth two-position three-way solenoid valve YV5 and the sixth two-position three-way solenoid valve YV6, respectively. The P and T ports of the fifth two-position three-way solenoid valve YV5 and the sixth two-position three-way solenoid valve YV6 are connected to the pilot control oil port X and the leakage oil port Y on the return oil valve plate through the internal control oil circuit, so as to control the reversing of the second three-position six-way valve.

7. The control valve assembly of a double-outlet square baler according to claim 6, characterized in that: The cylinder reversing valve plate is also equipped with an eighth 2nd position three-way solenoid valve YV8 and a ninth 2nd position three-way solenoid valve YV9. The third 3rd position six-way valve is a hydraulically controlled reversing valve. Its two control ports are respectively connected to the A port of the eighth 2nd position three-way solenoid valve YV8 and the ninth 2nd position three-way solenoid valve YV9. The P and T ports of the eighth 2nd position three-way solenoid valve YV8 and the ninth 2nd position three-way solenoid valve YV9 are respectively connected to the pilot control oil port X and the leakage oil port Y on the return oil valve plate through the internal control oil circuit, so as to control the reversing of the third 3rd position six-way valve.

8. A control valve assembly for a double-outlet square baler according to any one of claims 1-7, characterized in that: The intermediate valve plate is also equipped with a 72-position three-way solenoid valve YV7. The second pilot-operated electro-hydraulic control valve is a 2-position three-way hydraulic directional valve. One of its control ports is connected to port A of the 72-position three-way solenoid valve YV7. The P and T ports of the 72-position three-way solenoid valve YV7 are respectively connected to the pilot control oil port X and leakage oil port Y provided on the return oil valve plate through the internal control oil circuit, so as to control the directional switching of the second pilot-operated electro-hydraulic control valve.

9. The control valve assembly of a double-outlet square baler according to claim 8, characterized in that: The return valve plate integrates a second relief valve and a check valve. The check valve is located in the control oil circuit corresponding to the pilot control port X to prevent oil from flowing back to the pilot pump. The two ends of the second relief valve are respectively connected to the pilot control port X and the leakage port Y to limit the maximum pressure of the control oil circuit and prevent excessive pressure from damaging the two-position three-way solenoid valve.

10. A control valve assembly for a double-outlet square baler according to claim 1 or 9, characterized in that: The cylinder reversing valve plate also integrates a first relief valve and a third relief valve. The two ends of the first relief valve and the third relief valve are respectively connected to the working port B1, A1 and the return port T1 through internal oil passages, which are used to limit the maximum liquid outlet pressure of the working port A1 and B1.

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