Variable pump hydraulic system for pressure self-adaptive main and auxiliary supporting function
By introducing a load-sensitive variable pump and hydraulic control signal feedback into the hydraulic system, the pressure self-adaptation of the main and auxiliary supports is realized, the motion coordination problem of the main and auxiliary supports is solved, the convenience and stability of the system are improved, and the electrical control logic is simplified.
Patent Information
- Application Number
- CN202520101182.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2035-01-16
AI Technical Summary
In mechanical equipment, when the main support and auxiliary support are not positioned in the same way, how can we coordinate their movement speed and output force or torque, especially when the auxiliary support is off the load or at the end of its stroke, to avoid sudden changes in flow and vibration, while simplifying the electrical control logic?
A variable pump hydraulic system for pressure adaptive main and auxiliary support functions is adopted, including a load-sensitive variable pump, a main cylinder, an auxiliary cylinder, a balance valve group, and a main valve group. The pressure adaptation of the main and auxiliary supports is realized through hydraulic control signals. The pressure signal of the main cylinder is fed back by the load-sensitive variable pump to adjust the output flow and maintain a fixed difference relationship between the pressure of the auxiliary cylinder and the main cylinder.
It achieves synchronous movement between the auxiliary cylinder and the main cylinder, avoids sudden speed changes and vibrations, simplifies the electronic control logic, and improves the convenience and operational stability of the system. It is suitable for hydraulic systems with main and auxiliary supports.
Smart Images
Figure CN223549522U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of engineering machinery, special vehicles, and industrial equipment, and specifically relates to a variable pump hydraulic system for pressure adaptive main and auxiliary support functions. Background Technology
[0002] In mechanical equipment, when space constraints prevent the installation of exceptionally large support cylinders or make installation of extra-large support cylinders uneconomical, auxiliary supports are a common solution. When the main and auxiliary supports are positioned differently, especially when they have different leverage ratios, coordinating their movement speeds and output forces or torques becomes a crucial issue.
[0003] The first existing option is:
[0004] Connecting the main cylinder (or motor) and auxiliary cylinder (or motor) directly in parallel to the hydraulic system allows for excellent responsiveness, ensuring that the pressure in both cylinders remains equal and that the main and auxiliary supports provide force (or torque) evenly. However, this design also causes a sudden increase in speed and significant vibration when the auxiliary cylinder (motor) is unloaded or at the end of its stroke, as the pump output flow will entirely flow into the main cylinder (motor).
[0005] The existing option two is:
[0006] The main and auxiliary cylinders (or motors) are connected to the hydraulic system via their respective flow control valves. This design allows for independent speed control of the main and auxiliary cylinders (motors), preventing sudden flow changes and vibrations in the main cylinder (motor) when the auxiliary cylinder (motor) is unloaded. However, this design suffers from challenges due to the different lever ratios of the main and auxiliary cylinders (motors), making it difficult to match their movement speeds (i.e., the flow rate entering the main and auxiliary cylinders) and ensure that the auxiliary cylinder (motor) always follows the main cylinder (motor), resulting in uniform force (torque). Furthermore, preventing the faster support cylinder from causing load movement under light loads also requires complex electronic control logic.
[0007] Therefore, it is particularly important to develop a convenient and energy-saving hydraulic system that uses internal hydraulic pressure signals to achieve pressure self-adaptation and main / auxiliary support functions. Summary of the Invention
[0008] The purpose of this invention is to address the shortcomings of the existing technology by providing a variable pump hydraulic system for pressure adaptive main and auxiliary support functions.
[0009] To solve the above technical problems, the technical solution adopted by this utility model is as follows:
[0010] A variable pump hydraulic system for pressure adaptive main and auxiliary support functions includes a load-sensitive variable pump, a main cylinder, an auxiliary cylinder, a balance valve group, a main valve group, and a check valve connected to the inlet of the load-sensitive variable pump. The oil inlet of the check valve is connected to the load-sensitive variable pump, and the oil outlet is connected to the P port of the main valve group.
[0011] The main valve group's Ls port is connected to the third oil port of the load-sensitive variable pump, the A port is connected to the A1 port of the balance valve group, the S port is connected to the auxiliary oil cylinder, the Z port is connected to the Z1 port of the balance valve group, and the T port and R port are each connected to the oil tank separately.
[0012] The balancing valve group includes a hydraulically controlled check valve and a one-way balancing valve. The second port of the hydraulically controlled check valve is connected to the first port of the one-way balancing valve and the Z1 port of the balancing valve group. The third port of the hydraulically controlled check valve is connected to the third port of the one-way balancing valve and is connected to the C2 and B1 ports of the balancing valve group. The first port of the hydraulically controlled check valve is connected to the C1 port of the balancing valve group, and the second port of the one-way balancing valve is connected to the A1 port of the balancing valve group.
[0013] The main valve assembly includes a high-pressure selective shuttle valve, a hydraulically controlled proportional directional valve, a first electro-proportional pressure reducing relief valve, a second electro-proportional pressure reducing relief valve, a pressure compensation valve, a direct-acting relief valve, a first normally closed logic balance cone valve, a second normally closed logic balance cone valve, a pilot-operated solenoid directional valve, and a normally closed logic regulating slide valve.
[0014] The first port of the high-pressure selector shuttle valve is connected to the A port of the main valve group and the second port of the hydraulic proportional directional valve. The second port is connected to the port of the main valve group and the fourth port of the hydraulic proportional directional valve. The third port is connected to the third port of the pressure compensator and the LS port of the main valve group.
[0015] The sixth port of the hydraulic proportional directional valve is connected to the first port of the first electro-proportional pressure reducing relief valve, the first port of the hydraulic proportional directional valve is connected to the first port of the second electro-proportional pressure reducing relief valve, the third port of the hydraulic proportional directional valve is connected to the first port of the pressure compensation valve, and the fifth port of the hydraulic proportional directional valve is connected to the R port of the main valve group.
[0016] The second oil ports of both the first and second electro-proportional pressure reducing relief valves are connected to the second oil port of the pressure compensation valve and connected to the P port of the main valve group. The second oil port of the pressure compensation valve is also connected to the first oil port of the direct-acting relief valve and connected to the P port of the main valve group.
[0017] The second port of the first normally closed logic balance cone valve is connected to the second port of the second normally closed logic balance cone valve, and they are both connected to the S port of the main valve group. The fourth port of the first normally closed logic balance cone valve is connected to the fourth port of the second normally closed logic balance cone valve, and they are both connected to the third port of the pilot directional solenoid valve and the T port of the main valve group.
[0018] The third port of the first normally closed logic balance cone valve is connected to the second port of the pilot solenoid directional valve, and the first port of the first normally closed logic balance cone valve is connected to the first port of the pilot solenoid directional valve and to the P port of the valve group.
[0019] The third port of the second normally closed logic balance cone valve is connected to the fourth port of the pilot solenoid valve, and the first port is connected to the first port of the normally closed logic regulating slide valve.
[0020] The second port of the normally closed logic regulating slide valve is connected to the R port of the main valve group, and the third port of the normally closed logic regulating slide valve is connected to the Z port of the main valve group.
[0021] When the main cylinder retracts, the third port of the normally closed logic regulating slide valve receives the load pressure signal of the main cylinder through the Z port of the main valve group and the Z1 port of the balance valve group, and adjusts the valve opening of the normally closed logic regulating slide valve according to this pressure signal. The load pressure of the auxiliary cylinder is always higher than the pressure of the main cylinder by a fixed value.
[0022] The fixed value is 0.7 MPa.
[0023] When the main cylinder extends, the high-pressure selector shuttle valve receives the pressure signal Ls from the main cylinder and feeds it back to the third port of the load-sensitive variable pump. The load-sensitive variable pump adjusts its output flow according to the feedback signal, and the output flow meets the flow requirements of the main cylinder and the auxiliary cylinder, and ensures that the outlet pressure of the load-sensitive variable pump is always higher than the signal pressure by a fixed value of 2.
[0024] The second fixed value is 2 MPa.
[0025] The movement speed of the main hydraulic cylinder is adjusted by the opening size of the hydraulic proportional directional valve, while the movement of the auxiliary hydraulic cylinder is synchronized with the movement of the main hydraulic cylinder.
[0026] When the main cylinder extends, the output flow of the load-sensitive variable pump is the sum of the flow entering the main cylinder through the proportional directional valve and the flow entering the auxiliary cylinder.
[0027] The beneficial effects of this utility model are:
[0028] (1) The variable pump hydraulic system for pressure adaptive main and auxiliary support functions, by arranging a load-sensitive variable pump, a main cylinder, an auxiliary cylinder, a balance valve group, a main valve group, and a check valve connected to the inlet of the load-sensitive variable pump, enables the auxiliary cylinder to follow the movement of the main cylinder in real time; at the same time, the pressure of the auxiliary cylinder and the pressure of the main cylinder are in a fixed difference relationship, thereby realizing that the pressure and displacement between the auxiliary support and the main support follow each other in real time, ensuring that the main cylinder and the auxiliary cylinder output force or torque in a balanced manner. Moreover, the pressure relationship between the main cylinder and the auxiliary cylinder in this system is automatically matched by the hydraulic control signal, which improves the convenience of the system and reduces the control difficulty of the electrical control system. It can be applied to hydraulic systems that have both main support and auxiliary support and whose main support load changes with displacement or angle.
[0029] (2) Good responsiveness
[0030] This pressure-adaptive main and auxiliary support variable pump hydraulic system collects the pressure signal from the main cylinder and feeds it back to the variable pump. At the same time, the auxiliary cylinder is directly connected to the pump outlet through a logic valve, so that even if there is a lever difference between the main cylinder and the auxiliary cylinder, the auxiliary cylinder can always follow the movement of the main cylinder, with good responsiveness.
[0031] (3) Stable operation
[0032] Since the speed of load movement is determined only by the opening of the main cylinder control valve, the flow rate into the main cylinder remains constant even when the auxiliary cylinder is disengaged, preventing large speed changes and ensuring smooth operation.
[0033] (4) Easy to control;
[0034] During the load retraction process, the movement of the main cylinder and the pressure relationship between the auxiliary cylinder are regulated by hydraulic control signal feedback. During the extension process of the main cylinder, the pressure of the main cylinder and the outlet pressure of the variable pump, i.e. the pressure of the auxiliary cylinder, are also regulated by hydraulic control signal feedback, which avoids complex electronic control logic control and simplifies control. Attached Figure Description
[0035] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation
[0036] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.
[0037] This utility model provides a variable pump hydraulic system for pressure adaptive main and auxiliary support functions, such as... Figure 1 As shown.
[0038] A variable pump hydraulic system for pressure adaptive main and auxiliary support functions includes a load-sensitive variable pump 16, a main cylinder 1, an auxiliary cylinder 4, a balance valve group I, a main valve group II, and a check valve connected to the inlet of the load-sensitive variable pump 16. The inlet of the check valve is connected to the load-sensitive variable pump, and the outlet is connected to the P port of the main valve group. The Ls port of the main valve group II is connected to the third port of the load-sensitive variable pump 16, the A port is connected to the A1 port of the balance valve group, the S port is connected to the auxiliary cylinder, the Z port is connected to the Z1 port of the balance valve group, and the T port and R port are each connected to the oil tank separately.
[0039] The balancing valve group includes a hydraulically controlled check valve and a one-way balancing valve. The second port of the hydraulically controlled check valve is connected to the first port of the one-way balancing valve and the Z1 port of the balancing valve group. The third port of the hydraulically controlled check valve is connected to the third port of the one-way balancing valve and is connected to the C2 and B1 ports of the balancing valve group. The first port of the hydraulically controlled check valve is connected to the C1 port of the balancing valve group, and the second port of the one-way balancing valve is connected to the A1 port of the balancing valve group.
[0040] The main valve group II includes a high-pressure selective shuttle valve 5, a hydraulically controlled proportional directional valve 6, a first electro-proportional pressure reducing relief valve 7, a second electro-proportional pressure reducing relief valve 8, a pressure compensation valve 9, a direct-acting relief valve 10, a first normally closed logic balance cone valve 11, a second normally closed logic balance cone valve 12, a pilot-operated solenoid directional valve 13, and a normally closed logic regulating slide valve 14. The movement speed of the main cylinder 1 is adjusted by the opening size of the hydraulically controlled proportional directional valve 6, while the movement of the auxiliary cylinder 4 is synchronized with the movement of the main cylinder 1.
[0041] The first port of the high-pressure selector shuttle valve 5 is connected to the A port of the main valve group and the second port of the hydraulic proportional directional valve 6. The second port is connected to the B port of the main valve group and the fourth port of the hydraulic proportional directional valve. The third port is connected to the third port of the pressure compensator 9 and the LS port of the main valve group.
[0042] The sixth port of the hydraulic proportional directional valve is connected to the first port of the first electro-proportional pressure reducing relief valve 7. The first port of the hydraulic proportional directional valve is connected to the first port of the second electro-proportional pressure reducing relief valve 8. The third port of the hydraulic proportional directional valve is connected to the first port of the pressure compensation valve. The fifth port of the hydraulic proportional directional valve is connected to the R port of the main valve group.
[0043] The second oil ports of the first electro-proportional pressure reducing relief valve 7 and the second electro-proportional pressure reducing relief valve 8 are both connected to the second oil port of the pressure compensation valve 9 and connected to the P port of the main valve group. The second oil port of the pressure compensation valve 9 is also connected to the first oil port of the direct-acting relief valve and connected to the P port of the main valve group.
[0044] The second port of the first normally closed logic balance cone valve 11 and the second port of the second normally closed logic balance cone valve 12 are connected together and connected to the S port of the main valve group. The fourth port of the first normally closed logic balance cone valve 11 and the fourth port of the second normally closed logic balance cone valve 12 are connected together and connected to the third port of the pilot directional solenoid valve 13 and the T port of the main valve group.
[0045] The third port of the first normally closed logic balance cone valve 11 is connected to the second port of the pilot solenoid directional valve 13, and the first port of the first normally closed logic balance cone valve 11 is connected to the first port of the pilot solenoid directional valve 13 and to the P port of the valve group.
[0046] The third port of the second normally closed logic balance cone valve 12 is connected to the fourth port of the pilot solenoid valve 13, and the first port is connected to the first port of the normally closed logic regulating slide valve 14.
[0047] The second port of the normally closed logic regulating slide valve 14 is connected to the R port of the main valve group, and the third port of the normally closed logic regulating slide valve is connected to the Z port of the main valve group.
[0048] When the main cylinder retracts, the third port of the normally closed logic regulating slide valve 14 receives the load pressure signal of the main cylinder through the Z port of the main valve group and the Z1 port of the balance valve group, and adjusts the valve opening of the normally closed logic regulating slide valve according to this pressure signal; when the main cylinder retracts, the Z port of the main valve group II receives the load pressure signal of the main cylinder 1, and adjusts the valve opening of the normally closed logic regulating slide valve 14 in the main valve group, so that the load pressure of the auxiliary cylinder 4 is always higher than the pressure of the main cylinder 1 by a fixed value; in this embodiment, the fixed value is 0.7 MPa, that is, the spring setting value of the normally closed logic regulating slide valve 14 is 0.7 MPa; the oil in the auxiliary cylinder 4 returns to the oil tank after being throttled by the normally closed logic regulating slide valve 14.
[0049] When the main cylinder extends, the shuttle valve 5 receives the pressure signal of the main cylinder Ls and feeds it back to the third port of the load-sensitive variable pump 16. The load-sensitive variable pump 16 adjusts the output flow according to the feedback signal, and the output flow meets the flow requirements of the main cylinder 1 and the auxiliary cylinder 4, and ensures that the outlet pressure of the load-sensitive variable pump 16 is always higher than the signal pressure by a fixed value of 2. In this embodiment, the fixed value of 2 is 2 MPa, that is, the sensitive valve spring setting value of the load-sensitive variable pump 16 is 2 MPa. After the outlet ④ of the load-sensitive variable pump 16 enters the P port of the main valve group II through the check valve, one path enters the main oil cylinder 1 after passing through the throttling action of the pressure compensation valve 9 and the hydraulic proportional directional valve 6. The other path enters the auxiliary oil cylinder 4 without throttling through the first normally closed logic balance cone valve 11. When the load extends, the pressure of the auxiliary oil cylinder 4 is equal to that of the outlet of the load-sensitive variable pump 16. The pressure of the main oil cylinder 1 is lower than that of the outlet of the load-sensitive variable pump 16 by a fixed value of 2. The spring setting value of the pump-sensitive valve is 2MPa, that is, when the load extends, the pressure of the auxiliary cylinder 4 is always higher than that of the main oil cylinder 1 by a fixed value of 2MPa.
[0050] When the main cylinder 1 extends, the output flow of the load-sensitive variable pump 16 is the sum of the flow entering the main cylinder 1 through the proportional directional valve 6 and the flow entering the auxiliary cylinder 4. When the main cylinder 1 retracts, the output flow of the load-sensitive variable pump 16 is the flow entering the main cylinder 1 after passing through the proportional directional valve 6.
[0051] When the main cylinder 1 extends, the flow rate into the main cylinder 1 is unaffected the moment the auxiliary cylinder 4 disengages from the load (due to the presence of the compensation valve 9, the pressure difference across the hydraulic proportional directional valve 6 remains constant), thus preventing sudden speed changes and vibrations in the main cylinder 1 caused by the moment the auxiliary cylinder 4 disengages. After the auxiliary cylinder 4 disengages, the swashplate angle of the load-sensitive variable pump 16 decreases, and at this time, the load-sensitive variable pump 16 only outputs the flow rate required to adapt to the movement of the main cylinder 1. When the main cylinder 1 retracts, the flow rate into the main cylinder 1 is unaffected the moment the load contacts the auxiliary cylinder 4, and the load-sensitive variable pump 16 only outputs the flow rate required to adapt to the movement of the main cylinder.
[0052] When the main cylinder 1 stops moving midway, the first normally closed logic balance cone valve 11 and the second normally closed logic balance cone valve 12 in the main valve group II ensure that the auxiliary cylinder 4 has a very small leakage amount, preventing the main cylinder 1 from operating under overpressure due to leakage and retraction of the auxiliary cylinder 4.
[0053] When the main cylinder 1 stops moving, the hydraulic check valve 2 ensures that the main cylinder 1 has a very small leakage amount, preventing the main cylinder 1 from unexpectedly retracting due to leakage oil flowing into the spring chamber of the normally closed logic regulating slide valve 14 from the balance valve group Z1 port.
[0054] The load feedback signal of the load-sensitive variable pump 16 is taken from the high-pressure side pressure of the main cylinder 1 and is not compared with that of the auxiliary cylinder 4. The pressure build-up and variable pressure of the load-sensitive variable pump 16 are only related to the signal of the main cylinder 1 and are independent of the auxiliary cylinder 4. Utilizing the inherent characteristics of the load-sensitive system, the outlet pressure of the load-sensitive variable pump 16 is always higher than the pressure of the main cylinder 1 by a fixed value of 2 MPa. At the same time, since the outlet of the load-sensitive variable pump 16 is directly connected to the auxiliary cylinder 4 through a logic cone valve, the pressure of the auxiliary cylinder 4 is equal to the outlet pressure of the load-sensitive variable pump 16 when the load extends. That is, when the load extends, the pressure of the auxiliary cylinder 4 is always higher than the pressure of the main cylinder 1 by a fixed value of 2 MPa.
[0055] The following detailed description, in conjunction with specific embodiments, further illustrates the point:
[0056] The balancing valve assembly I includes a hydraulically controlled check valve 2 and a one-way balancing valve 3. The ② port of the hydraulically controlled check valve and the ① port of the one-way balancing valve are connected to the Z1 port of the balancing valve assembly. The ③ port of the hydraulically controlled check valve and the ③ port of the one-way balancing valve are connected to the C2 and B1 ports of the balancing valve assembly. The ① port of the hydraulically controlled check valve is connected to the C1 port of the balancing valve assembly, and the ② port of the one-way balancing valve is connected to the A1 port of the balancing valve assembly.
[0057] The main valve group II includes a high-pressure selective shuttle valve 5, a hydraulically controlled proportional directional valve 6, an electro-proportional pressure reducing relief valve 7, an electro-proportional pressure reducing relief valve 8, a pressure compensation valve 9, a direct-acting relief valve 10, a normally closed logic balance cone valve 11, a normally closed logic balance cone valve 12, a pilot-operated solenoid directional valve 13, and a normally closed logic regulating slide valve 14.
[0058] The ① port of the high-pressure selector shuttle valve 5 inside the main valve group is connected to the A port of the valve group and the ② port of the hydraulically controlled proportional directional valve 6. The ② port is connected to the B port of the valve group and the ④ port of the hydraulically controlled proportional directional valve. The ③ port is connected to the ③ port of the pressure compensator 9 and the LS port of the valve group.
[0059] Port 6 of the hydraulic proportional directional valve 6 is connected to port 1 of the electro-proportional pressure reducing relief valve 7, port 1 of the electro-proportional pressure reducing relief valve 8 is connected to port 1, port 3 of the valve 6 is connected to port 1 of the pressure compensation valve 9, and port 5 of the valve assembly is connected to port R. Ports 2 of the electro-proportional pressure reducing relief valves 7 and 8 are connected to port 2 of the compensation valve 9 and are jointly connected to port P of the valve assembly. The ② port of pressure compensation valve 9 is connected to the ① port of direct-acting relief valve and together they are connected to the P port of valve group. The ② port of normally closed logic balance cone valve 11 and the ② port of normally closed logic balance cone valve 12 are connected to the S port of valve group. The ④ port of normally closed logic balance cone valve 11 and the ④ port of normally closed logic balance cone valve 12 are connected to the ③ port of pilot directional solenoid valve 13 and the T port of valve group. The ③ port of normally closed logic balance cone valve 11 is connected to the ② port of pilot solenoid directional valve 13, and its ① port is connected to the ① port of pilot solenoid directional valve 13 and connected to the P port of valve group. The ③ port of normally closed logic balance cone valve 12 is connected to the ④ port of pilot solenoid valve 13, and its ① port is connected to the ① port of normally closed logic regulating slide valve 14. The ② port of normally closed logic regulating slide valve 14 is connected to the R port of valve group, and its ③ port is connected to the Z port of valve group.
[0060] When the main cylinder 1 extends, the shuttle valve 5 receives the pressure signal Ls from the main cylinder 1 (motor) and feeds it back to the oil port ③ of the variable pump 16. The variable pump 16 adjusts the pump output flow according to the feedback signal. Under the premise that the pump output flow meets the flow requirements of the main cylinder 1 (motor) and the auxiliary cylinder 4 (motor), the outlet pressure of the pump 16 is always maintained at a fixed value (2MPa) higher than the signal pressure.
[0061] When the main cylinder 1 retracts, the oil port ③ of the normally closed logic regulating slide valve 14 receives the load pressure signal of the main cylinder 1 (motor) through the main valve group Z port and the balance valve group Z1 port. Based on this pressure signal, the valve port opening of the normally closed logic regulating slide valve 14 is adjusted so that the pressure at the valve port ① (i.e., the pressure of the auxiliary cylinder 4) is always higher than the load pressure signal (i.e., the pressure of the main cylinder 1) by a fixed value (0.7MPa).
[0062] When the main cylinder 1 stops moving, the pilot valves of both the main cylinder 1 and the auxiliary cylinder 4 (motor) have no signal, and the pressure signal fed back to the pump by the shuttle valve 5 is zero. At this time, no flow enters the main cylinder 1 and the auxiliary cylinder 4 (motor) from the pump outlet, and the outlet pressure of pump 16 is the set value of the differential pressure valve spring (2MPa). At this time, pump 16 is on standby with low pressure and near-zero flow, achieving energy saving. At the same time, due to the function of the hydraulic control check valve 2, the normally closed logic balance cone valve 11, and the normally closed logic balance cone valve 12, both the main cylinder 1 and the auxiliary cylinder 4 can be reliably locked, avoiding retraction under load and uneven force on the main cylinder 1 and the auxiliary cylinder 4 due to leakage.
[0063] The working principle of this utility model is as follows:
[0064] When the electro-proportional pressure reducing relief valve 7 and the left electromagnet of the pilot solenoid directional valve in main valve group II are energized, the left side of the hydraulically controlled proportional directional valve 6 operates. Simultaneously, the normally closed logic balance cone valve 11 opens and the normally closed logic balance cone valve 12 closes. One path of the oil from the outlet of variable pump 16 passes through pressure compensation valve 9, hydraulically controlled proportional directional valve 6, and balance valve group 1 into the main cylinder 1; the other path passes through the normally closed logic balance cone valve 11 into the auxiliary cylinder. The main cylinder 1 and auxiliary cylinder 4 extend. Feedback shuttle valve 5 collects the pressure signal from the main cylinder 1 and feeds it back to variable pump 16 and pressure compensation valve 9, causing variable pump 16 to output the required flow rate for the main cylinder 1 and auxiliary cylinder 4 and maintaining the outlet pressure of pump 16 greater than a fixed value (2MPa) of the pressure feedback signal.
[0065] When the electro-proportional pressure reducing relief valve 8 and the right electromagnet of the pilot solenoid directional valve 13 in the main valve group II are energized, the right side of the hydraulic proportional directional valve 6 operates. At the same time, the normally closed logic balance cone valve 11 closes and the normally closed logic balance cone valve 12 opens. The oil from the outlet of the variable pump 16 enters the upper chamber of the main cylinder 1 through the pressure compensation valve 9, the hydraulic proportional directional valve 6, and the balance valve group 1. The main cylinder 1 retracts, and the retraction speed is related to the flow rate of the oil entering the rod chamber of the main cylinder 1. The normally closed logic regulating slide valve 14 adjusts the valve opening according to the pressure signal of the Z port of the rodless chamber of the main cylinder 1. After the load contacts the auxiliary cylinder 4, the pressure of the auxiliary cylinder 4 is always higher than the pressure of the main cylinder 1 by a fixed value (0.7MPa). The speed of the load throughout its movement is only related to the flow rate entering the main cylinder 1 and is independent of the auxiliary cylinder 4. The load feedback shuttle valve 5 collects the pressure signal of the main cylinder 1 and feeds it back to the variable pump 16 and the pressure compensation valve 9. This ensures that the variable pump 16 only outputs the flow rate required by the main cylinder 1 and maintains the pump outlet pressure greater than a fixed value (2MPa) of the rod chamber pressure feedback signal of the main cylinder 1.
[0066] When there are no electrical control signals in the main valve group II, the main cylinder 1 is reliably locked and maintains its original state under the action of the hydraulic check valve 2, and the auxiliary cylinder 4 is reliably locked and maintains its original state under the action of the normally closed logic balance cone valves 11 and 12. When stopped, both the main cylinder 1 and the auxiliary cylinder 4 are locked by cone valves, so the leakage is very low, ensuring that the main cylinder 1 and the auxiliary cylinder 4 are evenly stressed when stopped, and avoiding overload and overpressure caused by leakage and retraction of one cylinder.
[0067] This invention utilizes a hydraulic feedback circuit within the main valve assembly I to ensure that when the load extends, the auxiliary cylinder 4 always moves in tandem with the main cylinder 1, maintaining a pressure always higher than the main cylinder 1 by a fixed value (2 MPa). Similarly, when the load retracts, the auxiliary cylinder 4 also always moves in tandem with the main cylinder 1, maintaining a pressure always higher than the main cylinder 1 by a fixed value (0.7 MPa). When the load stops, both the main cylinder 1 and the auxiliary cylinder 4 reliably lock, ensuring that they bear the load evenly. Except for the load extension and retraction, which require electrical control signals, the pressure distribution between the main cylinder 1 and the auxiliary cylinder 4 is automatically completed by hydraulic control signals throughout the entire process, eliminating the need for complex electrical control logic and simplifying operation.
[0068] If this patent uses terms such as "first" and "second" to define components, those skilled in the art should know that the use of "first" and "second" is merely for the convenience of describing this utility model and simplifying the description, and the above terms have no special meaning.
[0069] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
[0070] In the description of this utility model, it should be understood that the terms "front", "rear", "left", "right", "center", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this utility model and simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.
Claims
1. A variable pump hydraulic system for pressure adaptive main and auxiliary support functions, characterized in that: It includes a load-sensitive variable pump, a main cylinder, an auxiliary cylinder, a balance valve assembly, a main valve assembly, and a check valve connected to the inlet of the load-sensitive variable pump. The oil inlet of the check valve is connected to the load-sensitive variable pump, and the oil outlet is connected to the P port of the main valve assembly. The main valve group's Ls port is connected to the third oil port of the load-sensitive variable pump, the A port is connected to the A1 port of the balance valve group, the S port is connected to the auxiliary oil cylinder, the Z port is connected to the Z1 port of the balance valve group, and the T port and R port are each connected to the oil tank separately. The balancing valve group includes a hydraulically controlled check valve and a one-way balancing valve. The second port of the hydraulically controlled check valve is connected to the first port of the one-way balancing valve and the Z1 port of the balancing valve group. The third port of the hydraulically controlled check valve is connected to the third port of the one-way balancing valve and is connected to the C2 and B1 ports of the balancing valve group. The first port of the hydraulically controlled check valve is connected to the C1 port of the balancing valve group, and the second port of the one-way balancing valve is connected to the A1 port of the balancing valve group.
2. A variable pump hydraulic system for pressure adaptive main and auxiliary support function according to claim 1, characterized in that: The main valve assembly includes a high-pressure selective shuttle valve, a hydraulically controlled proportional directional valve, a first electro-proportional pressure reducing relief valve, a second electro-proportional pressure reducing relief valve, a pressure compensation valve, a direct-acting relief valve, a first normally closed logic balance cone valve, a second normally closed logic balance cone valve, a pilot-operated solenoid directional valve, and a normally closed logic regulating slide valve. The first port of the high-pressure selector shuttle valve is connected to the A port of the main valve group and the second port of the hydraulic proportional directional valve. The second port is connected to the port of the main valve group and the fourth port of the hydraulic proportional directional valve. The third port is connected to the third port of the pressure compensator and the LS port of the main valve group. The sixth port of the hydraulic proportional directional valve is connected to the first port of the first electro-proportional pressure reducing relief valve, the first port of the hydraulic proportional directional valve is connected to the first port of the second electro-proportional pressure reducing relief valve, the third port of the hydraulic proportional directional valve is connected to the first port of the pressure compensation valve, and the fifth port of the hydraulic proportional directional valve is connected to the R port of the main valve group. The second oil ports of both the first and second electro-proportional pressure reducing relief valves are connected to the second oil port of the pressure compensation valve and connected to the P port of the main valve group. The second oil port of the pressure compensation valve is also connected to the first oil port of the direct-acting relief valve and connected to the P port of the main valve group. The second port of the first normally closed logic balance cone valve is connected to the second port of the second normally closed logic balance cone valve, and they are both connected to the S port of the main valve group. The fourth port of the first normally closed logic balance cone valve is connected to the fourth port of the second normally closed logic balance cone valve, and they are both connected to the third port of the pilot directional solenoid valve and the T port of the main valve group. The third port of the first normally closed logic balance cone valve is connected to the second port of the pilot solenoid directional valve, and the first port of the first normally closed logic balance cone valve is connected to the first port of the pilot solenoid directional valve and to the P port of the valve group. The third port of the second normally closed logic balance cone valve is connected to the fourth port of the pilot solenoid valve, and the first port is connected to the first port of the normally closed logic regulating slide valve. The second port of the normally closed logic regulating slide valve is connected to the R port of the main valve group, and the third port of the normally closed logic regulating slide valve is connected to the Z port of the main valve group.
3. A variable pump hydraulic system for pressure adaptive main and auxiliary support function according to claim 1, characterized in that: When the main cylinder retracts, the third port of the normally closed logic regulating slide valve receives the load pressure signal of the main cylinder through the Z port of the main valve group and the Z1 port of the balance valve group, and adjusts the valve opening of the normally closed logic regulating slide valve according to this pressure signal. The load pressure of the auxiliary cylinder is always higher than the pressure of the main cylinder by a fixed value.
4. A variable pump hydraulic system for pressure adaptive main and auxiliary support function according to claim 3, characterized in that: The fixed value is 0.7 MPa.
5. A variable pump hydraulic system for pressure adaptive main and auxiliary support function according to claim 1, characterized in that: When the main cylinder extends, the high-pressure selector shuttle valve receives the pressure signal Ls from the main cylinder and feeds it back to the third port of the load-sensitive variable pump. The load-sensitive variable pump adjusts its output flow according to the feedback signal, and the output flow meets the flow requirements of the main cylinder and the auxiliary cylinder, and ensures that the outlet pressure of the load-sensitive variable pump is always higher than the signal pressure by a fixed value of 2.
6. A variable pump hydraulic system for pressure adaptive main and auxiliary support function according to claim 5, characterized in that: The second fixed value is 2 MPa.
7. A variable pump hydraulic system for pressure adaptive main and auxiliary support function according to any one of claims 1 to 6, characterized in that: The movement speed of the main hydraulic cylinder is adjusted by the opening size of the hydraulic proportional directional valve, while the movement of the auxiliary hydraulic cylinder is synchronized with the movement of the main hydraulic cylinder.
8. A variable pump hydraulic system for pressure adaptive main and auxiliary support function according to claim 7, characterized in that: When the main cylinder extends, the output flow of the load-sensitive variable pump is the sum of the flow entering the main cylinder through the proportional directional valve and the flow entering the auxiliary cylinder.