Forging frequency adjusting method of radial forging machine based on volume adjustment and hydraulic control system

Abstract

The invention discloses a radial forging machine forging frequency adjusting method based on volume adjustment and a hydraulic control system, and belongs to the technical field of radial forging machines. The system comprises a hammerhead unit, a power unit, a volume adjusting unit, a pressure control unit, a feedback unit and a control unit. According to the adjusting method, the volume of oil in a closed containing cavity of a hammer head is controlled, the relative position of the hammer head and a workpiece is changed, and alternate control over the forging period and the empty forging period is achieved so that the forging frequency can be adjusted. The limitation that the traditional technology depends on reduction of motor rotating speed frequency modulation is eliminated, the main driving rotating speed does not need to be changed in the forging frequency reduction process, single forging energy can be completely reserved, and the problems that output energy is reduced and forging force is insufficient due to rotating speed reduction are effectively solved; and the requirement for forging force required by the process is met while precise temperature control is ensured, and the forming quality of forgings is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of radial forging machine technology, specifically to a method for adjusting the forging frequency of a radial forging machine based on volume regulation and a hydraulic control system, as well as a method for adjusting the forging frequency based on the system. Background Technology

[0002] Radial forging, an advanced special forging process, involves high-frequency, synchronous radial forging of billets using hammers symmetrically arranged around their cross-section. It is primarily used for blanking and diameter reduction of ingots and bars, as well as the forming of long-shaft tubular components such as stepped shafts and gun barrels. During radial forging, the high-frequency impact of the hammers not only significantly improves production efficiency but also converts the work done by plastic deformation into heat energy, causing a continuous rise in workpiece temperature.

[0003] However, when forging difficult-to-deform materials such as stainless steel, high-temperature alloys, and titanium alloys, which have narrow hot working temperature windows, extremely high requirements are placed on temperature control. If the forging frequency is too high, leading to uncontrolled temperature rise, the workpiece is highly susceptible to overheating or burning. Overheating can cause grain coarsening and deterioration of microstructure properties; burning can cause grain boundary oxidation or melting, resulting in the direct scrapping of the workpiece. Therefore, for specific materials or specific process stages (such as the finishing stage), it is necessary to reduce the actual forging frequency to control the temperature rise.

[0004] Existing radial forging mill technology typically adjusts the frequency in the following ways: Existing technology 1: For example, Chinese patent CN202310398484.9 discloses a forging equipment and process for producing and processing die-forged basic parts, which changes the frequency according to the forging degree of the billet to improve efficiency.

[0005] Existing technology 2: For example, a high-precision radial forging machine control system disclosed in Chinese patent CN202510372965.1, although it has established a complete temperature and deformation monitoring mechanism through multi-source sensors, still mainly relies on adjusting the speed of the drive motor at the frequency execution level.

[0006] In traditional mechanical or hydrodynamic rotary forging mills, the hammer motion is typically driven by an eccentric shaft, and the impact energy largely depends on the flywheel inertia and speed of the transmission system. In such equipment, the hammer's impact frequency directly depends on the eccentric shaft's rotational speed, which is driven by the main motor via the transmission system. This results in a rigid, non-decoupled relationship between the impact frequency and the motor speed. Therefore, the currently common method of reducing the forging frequency by lowering the motor speed has a significant drawback: impact energy loss. According to the principles of physics, the kinetic energy of the flywheel and transmission system is proportional to the square of its rotational speed. When the motor speed is reduced to decrease the impact frequency in order to control temperature rise, the system's impact energy decreases dramatically, on a quadratic scale. This means that the hammer cannot provide sufficient deformation force at low frequencies, making it difficult to meet the forging requirements of materials with large deformation amounts and high strength that are difficult to deform.

[0007] Therefore, how to flexibly adjust the forging frequency that the workpiece actually bears without reducing the driving speed to maintain sufficient impact energy is a technical problem that urgently needs to be solved in current radial forging equipment. Summary of the Invention

[0008] The purpose of this invention is to provide a method for adjusting the forging frequency of a radial forging machine based on volumetric adjustment and a hydraulic control system, in order to solve the problem mentioned in the background art that currently, radial forging machines on the market generally reduce the forging frequency by reducing the motor speed, thereby controlling the forging temperature rise. However, this adjustment method will cause the system's impact energy to decrease quadratically, resulting in insufficient forging force and inability to meet the process requirements of difficult-to-deform materials.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a method for adjusting the forging frequency of a radial forging machine based on volume adjustment and a hydraulic control system, comprising a hammer unit, a volume adjustment unit, a pressure control unit, a power unit, a feedback unit, and a control unit; The hammer unit includes a hammer rod, a cylinder, an end cover, an eccentric shaft housing, and a return cylinder. The cylinder is fixedly disposed inside the eccentric shaft housing, the end cover is slidably disposed inside the cylinder, and the hammer rod is slidably disposed inside the cylinder. Seals are provided between the hammer rod and the cylinder, and between the end cover and the cylinder, respectively, so that the hammer rod, cylinder, and end cover together form a total sealed cavity. This total sealed cavity includes a chamber between the hammer rod and the cylinder and a chamber between the hammer rod and the end cover, and the two chambers are interconnected through an oil passage opened inside the hammer rod. The eccentric shaft housing has inlet and outlet oil passages communicating with the total sealed cavity. The return cylinder is a plunger cylinder disposed on the eccentric shaft housing, which maintains close contact with the hammer rod under the pressure of the working chamber to apply force. The volume adjustment unit includes an oil circuit switch and a volume compensation cylinder. The oil circuit switch is a hydraulic on / off valve with an opening control chamber and a closing control chamber, installed on the oil circuit connecting the volume compensation cylinder and the main sealed cavity, used to control the on / off of the oil circuit between the two. The volume compensation cylinder includes a main piston, a piston rod, and a cylinder body. The main piston and the cylinder body form a storage chamber for receiving or discharging working oil, which is connected to the main sealed cavity. One end of the piston rod is pressed against the main piston under the pressure of the C chamber, while the other end... One end extends into the C-cavity formed on the right side of the cylinder body and acts as the piston of the C-cavity; the C-cavity is connected to the rigid liquid tank through an oil circuit to form a high-pressure energy storage side; when the hammer rod retracts under the push of the return cylinder, if the oil circuit switch is opened, the oil in the total sealed cavity flows into the storage cavity of the volume compensation cylinder, pushing the main piston to move, and then pushing the piston rod to compress the oil on the high-pressure energy storage side for energy storage; when the hammer rod needs to extend, the high-pressure energy storage side releases energy to push the piston rod and the main piston to reset, and the oil in the storage cavity is returned to the total sealed cavity through the opened oil circuit switch; The pressure control unit includes a servo valve, a damper, a relief valve, a pressure reducing valve, and a second accumulator. The output of the servo valve is connected to the control chamber of the oil circuit switch via an oil circuit, used to control its opening and closing state. The damper is installed on the oil circuit between the control oil circuit and the closing control chamber of the oil circuit switch. When the servo valve is in the neutral position, the pressure oil in the control oil circuit is allowed to flow slowly into the closing control chamber through the damper to compensate for pressure loss caused by seal leakage and maintain the reliable closing state of the oil circuit switch. The relief valve is connected between the control chamber of the oil circuit switch and the return oil circuit 1, used to limit the maximum pressure of the control chamber. The second accumulator is connected to both the return oil end of the servo valve and the return oil port of the relief valve, used to absorb pressure shocks and stabilize the return oil pressure. The pressure reducing valve is connected to the high-pressure side oil circuit of the volume compensation cylinder, used to reduce the pressure of the high-pressure oil circuit 2 to the working pressure required by the downstream circuit. The power unit includes a first accumulator, a rigid liquid tank, a high-pressure oil circuit 1, a high-pressure oil circuit 2, a low-pressure oil circuit, a control oil circuit, a return oil circuit 1, a return oil circuit 2, and a return oil circuit 3. The high-pressure oil circuit 1 is connected to the first accumulator via a first check valve to fill it with liquid. The first accumulator is connected to the inlet of the servo valve via a second check valve, thereby providing working pressure oil to the servo valve. The high-pressure oil circuit 2 is connected to the rigid liquid tank sequentially via a pressure reducing valve and a third check valve to maintain the base pressure within the rigid liquid tank. The liquid tank is connected to the high-pressure side of the volume compensation cylinder to form an energy storage cavity. This energy storage cavity is configured to: receive and store the pressurized oil energy when the piston of the volume compensation cylinder is pushed by an external force; and use the stored energy and base pressure to push the piston of the volume compensation cylinder to reset when the external force is removed. The low-pressure oil circuit is connected to the volume compensation cylinder to maintain the pressure balance on the low-pressure side. The return oil circuit 1 is connected to the outlet of the overflow valve. The return oil circuit 2 is connected to the return port of the pressure reducing valve. The return oil circuit 3 is connected to the low-pressure return oil side of the volume compensation cylinder. The feedback unit includes a first displacement sensor, a second displacement sensor, a third displacement sensor, a first pressure sensor, and a second pressure sensor. The first displacement sensor is used to detect the displacement of the hammer rod relative to the eccentric shaft housing. The second displacement sensor is installed on the oil circuit switch and is used to detect the position of its valve core. The third displacement sensor is installed on the volume compensation cylinder and is used to detect its piston stroke. The first pressure sensor is connected to the low-pressure oil circuit and is used to monitor the pressure on the low-pressure return oil side of the volume compensation cylinder. The second pressure sensor is connected to the high-pressure energy storage side of the volume compensation cylinder and is used to monitor the pressure on the high-pressure energy storage side. The control unit includes a programmable controller for controlling the operation of each component based on feedback signals.

[0010] Furthermore, the present invention also provides a forging frequency adjustment method based on the above system. The control unit is configured to control the action of the hammer rod according to the relative position logic between the forging die and the workpiece. The control unit logically divides a complete forging cycle into a pressing segment and a return segment. The control unit identifies the process from the moment the forging die contacts the workpiece, through pressing to the bottom, until it completely leaves the workpiece as the actual forging stage. The process before the forging die contacts the workpiece in the pressing segment is identified as the unloaded pressing segment, and the process after the forging die leaves the workpiece in the return segment is identified as the unloaded return segment. The control unit detects the stroke position of the hammer rod through a first displacement sensor and determines whether to enter the actual forging stage by combining it with the preset stroke position corresponding to the workpiece contact.

[0011] Preferably, the control system reduces the forging frequency by periodically alternating between effective forging and dry forging; the specific adjustment process includes: Dry-firing control: During the dry-load return phase of the previous forging cycle and the dry-load pressing phase of the current forging cycle, the hammer rod is controlled to retract and prevent it from reaching the stroke required to contact the workpiece during pressing, thereby keeping the forging die and the workpiece in a non-contact state and preventing effective forging of the workpiece. Restoring forging control: During the no-load return phase of the no-load cycle and the no-load pressing phase of the next forging cycle, the stored oil is injected into the main sealed cavity through the volume compensation cylinder via the opened oil circuit switch, pushing the hammer rod to extend, so that the amount of pressure of the forging die on the workpiece is restored to the preset amount of pressure corresponding to the forging process, thereby restoring effective forging. Frequency control strategy: The control system operates in a cyclic mode of “performing one effective forging and then performing n-1 consecutive dry forgings”, reducing the actual forging frequency to 1 / n of the original frequency, where n is an integer greater than 1, and n is set by the operation interface or automatically set by the control system according to the process parameters.

[0012] Preferably, the process of not performing effective forging (dry forging) on ​​the workpiece during a forging cycle includes the following steps: When the first displacement sensor detects that the hammer rod has reached the preset maximum extension position, the controller commands the return cylinder to perform the return action. When the first displacement sensor detects that the hammer rod is in the return state, and the distance between the forging die and the workpiece calculated based on the hammer rod displacement is greater than the non-contact gap threshold δ preset according to the process requirements, the controller commands the servo valve to switch to the left position, so that the P port and the B port are connected, and the oil circuit switch is opened, connecting the main sealed cavity and the volume compensation cylinder; at this time, the return cylinder pushes the hammer rod to retract, and discharges the oil in the main sealed cavity into the volume compensation cylinder for storage. At the same time, the piston of the volume compensation cylinder moves to the right, compressing the oil on its high-pressure side, so that the pressure in the energy storage cavity between the rigid liquid tank and the volume compensation cylinder increases. When the first displacement sensor detects that the retraction amount of the hammer rod reaches the preset dry-firing retraction amount h0, the controller commands the servo valve to switch to the right position, so that the P port and the A port are connected, the oil circuit switch is closed, the connection between the main sealed cavity and the volume compensation cylinder is cut off, and the oil is locked in the volume compensation cylinder. Once the second displacement sensor confirms that the oil circuit switch is completely closed, the controller instructs the servo valve to switch to the neutral position and supplies oil to the control chamber of the oil circuit switch through the damper via the control oil circuit to maintain its closed state. Based on the feedback signals from the first and second pressure sensors, the controller adjusts the pressure balance on both sides of the volume compensation cylinder through the low-pressure oil circuit, and uses the third displacement sensor to monitor the piston position to ensure the stability of the stored oil volume. After completing the above steps, during the next cycle's pressing phase, when the hammer rod extends to its maximum stroke position, the forging die and the workpiece remain in a non-contact state, achieving dry firing within this cycle.

[0013] Preferably, the process of resuming effective forging of the workpiece in the next forging cycle includes the following steps: During the return stroke of the dry-firing cycle, when the controller determines that the recovery condition is met (the distance between the forging die and the workpiece calculated based on the hammer rod displacement is greater than the non-contact gap threshold δ preset according to the process requirements), the controller instructs the servo valve to switch to the left position, so that the P port and the B port are connected, and the oil circuit switch is opened, connecting the main sealed cavity and the volume compensation cylinder; at this time, under the pressure of the energy storage cavity formed by the rigid liquid tank and the volume compensation cylinder, the volume compensation cylinder quickly refills the oil stored in it into the main sealed cavity through the oil circuit switch, pushing the hammer rod to extend outward; When the first displacement sensor detects that the hammer rod has extended to the target position corresponding to the preset forging reduction h, the controller commands the servo valve to switch to the right position, so that the P port is connected to the A port, and drives the oil circuit switch to close, cutting off the connection between the main sealed cavity and the volume compensation cylinder. Once the second displacement sensor confirms that the oil circuit switch is completely closed, the controller instructs the servo valve to switch to the neutral position and supplies oil to the control chamber of the oil circuit switch through the damper via the control oil circuit to maintain its closed state. Based on the feedback signals from the first and second pressure sensors, the controller adjusts the pressure balance on both sides of the volume compensation cylinder through the low-pressure oil circuit, and uses the third displacement sensor to monitor its piston position to ensure system stability. After completing the above steps, in the next cycle of pressing down, the hammer rod extends normally under the drive of the eccentric shaft, so that the pressing amount of the forging die on the workpiece reaches the preset value h, realizing effective forging in this cycle.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: By adjusting the forging frequency through an innovative method of hydraulic volume regulation and cycle control, the limitations of traditional technology that relies on reducing motor speed to adjust the frequency are eliminated. In the process of reducing the forging frequency, there is no need to change the main drive speed, which can fully retain the energy of a single forging. This effectively avoids the problem of quadratic energy attenuation and insufficient forging force caused by the decrease in speed in traditional methods. It can ensure that the forging force requirements of the process are met while accurately controlling the temperature, thus guaranteeing the quality of the forging.

[0015] By employing a discrete cycle control strategy of "one forging + several dry forgings," the effective number of forgings is reduced, thereby effectively suppressing the temperature rise of the workpiece. This ensures that the forging temperature is strictly controlled within the process requirements, significantly reducing the risks of overheating and burning of the workpiece. It also avoids metallurgical defects such as grain coarsening, microstructure deterioration, and grain boundary oxidation, thus guaranteeing the strength, toughness, and fatigue performance of the forgings and improving the product qualification rate.

[0016] The forging frequency adjustment is flexible and controllable, with strong process adaptability. It can accurately reduce the frequency, which is convenient for process planning and parameter setting. Compared with the traditional analog continuous speed regulation, this digital discrete adjustment method has higher stability. It can flexibly adjust the forging rhythm according to the workpiece size, material characteristics and the needs of different process stages, which greatly improves the process flexibility and applicable material range of the equipment, enabling the radial forging machine to better adapt to a variety of forging scenarios.

[0017] The system constructs a closed-loop feedback mechanism based on multiple displacement and pressure sensors. The control unit can command the servo valve and oil circuit switch to complete precise volume switching during the hammer return phase according to the forging cycle, ensuring strict synchronization between frequency adjustment and forging process cycle, effectively avoiding malfunctions and ensuring system control accuracy. In addition, the synergistic effect of relief valve, pressure reducing valve, accumulator, damping element, etc. can absorb hydraulic shock, smooth pressure peaks, and prevent hydraulic fluctuations caused by volume switching or sudden working conditions, significantly improving the safety and reliability of equipment operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the hydraulic control system based on volume adjustment for the radial forging machine in an embodiment of the present invention; Figure 2 This is a schematic diagram of the forging cycle division and effective forging logic in this invention; Figure 3 This is a schematic diagram illustrating the principle of adjusting the forging frequency through periodic air-firing in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the hammer head unit in an embodiment of the present invention.

[0019] In the diagram: 1. Hammer rod; 2. Cylinder; 3. End cap; 4. Eccentric shaft housing; 5. Return cylinder; 6. First displacement sensor; 7. First check valve; 8. First accumulator; 9. Second check valve; 10. Servo valve; 11. Second accumulator; 12. Damping; 13. Overflow valve; 14. First pressure sensor; 15. Oil circuit switch; 16. Second displacement sensor; 17. Volume compensation cylinder; 18. Second pressure sensor; 19. Rigid liquid tank; 20. Third check valve; 21. Third displacement sensor; 22. Pressure reducing valve; 23. Forging die. Detailed Implementation

[0020] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] This invention provides the following technical solution: a method for adjusting the forging frequency of a radial forging machine based on volume regulation and a hydraulic control system: The hammer unit includes a hammer rod 1, a cylinder 2, an end cap 3, an eccentric shaft housing 4, and a return cylinder 5. The cylinder 2 is fixedly installed inside the eccentric shaft housing 4, the end cap 3 is slidably installed inside the cylinder 2, and the hammer rod 1 is slidably installed inside the cylinder 2. A forging die 23 is detachably installed at the front end of the hammer rod 1 for direct contact with the workpiece for forging. Seals are provided between the hammer rod 1 and the cylinder 2, and between the end cap 3 and the cylinder 2, so that the hammer rod 1, the cylinder 2, and the end cap 3 together form a total sealed cavity. This total sealed cavity includes a chamber between the hammer rod 1 and the cylinder 2 and a chamber between the hammer rod 1 and the end cap 3, and the two chambers are interconnected through an oil passage opened inside the hammer rod 1. An inlet and outlet oil passage communicating with the total sealed cavity is opened on the eccentric shaft housing 4. The return cylinder 5 is a plunger cylinder installed on the eccentric shaft housing 4, which maintains close contact with the hammer rod 1 under the pressure of the working chamber to apply force. The volume regulating unit includes an oil circuit switch 15 and a volume compensation cylinder 17. The oil circuit switch 15 is a hydraulic on / off valve with an opening control chamber and a closing control chamber, which is installed on the oil circuit connecting the volume compensation cylinder 17 and the main sealed cavity to control the on / off of the oil circuit between the two. The volume compensation cylinder 17 includes a main piston, a piston rod, and a cylinder body. The main piston and the cylinder body form a storage chamber for receiving or discharging working oil, which is connected to the main sealed cavity. One end of the piston rod is pressed against the main piston under the pressure of the C chamber, and the other end extends into the right side of the cylinder body. The formed C-cavity acts as the piston of the C-cavity; the C-cavity is connected to the rigid liquid tank 19 through an oil circuit to form a high-pressure energy storage side. When the hammer rod 1 retracts under the push of the return oil cylinder 5, if the oil circuit switch 15 is opened, the oil in the total sealed cavity flows into the storage cavity of the volume compensation cylinder 17, pushing the main piston to move, and then pushing the piston rod to compress the oil on the high-pressure energy storage side for energy storage; when the hammer rod 1 needs to extend, the high-pressure energy storage side releases energy to push the piston rod and the main piston to reset, and the oil in the storage cavity is returned to the total sealed cavity through the opened oil circuit switch 15. The pressure control unit includes a servo valve 10, a damper 12, a relief valve 13, a pressure reducing valve 22, and a second accumulator 11. The output end of the servo valve 10 is connected to the control chamber of the oil circuit switch 15 via an oil circuit to control its opening and closing state. The damper 12 is installed on the oil circuit between the control oil circuit and the closing control chamber of the oil circuit switch 15. When the servo valve 10 is in the neutral position, the pressure oil in the control oil circuit is allowed to be slowly replenished to the closing control chamber through the damper 12 to compensate for the pressure loss caused by sealing leakage and maintain the reliable closing state of the oil circuit switch 15. The relief valve 13 is connected between the control chamber of the oil circuit switch 15 and the return oil circuit 1 to limit the maximum pressure of the control chamber. The second accumulator 11 is connected to both the return oil end of the servo valve 10 and the return oil port of the relief valve 13 to absorb pressure shocks and stabilize the return oil pressure. The pressure reducing valve 22 is connected to the high-pressure side oil circuit of the volume compensation cylinder 17 to reduce the pressure of the high-pressure oil circuit 2 to the working pressure required by the downstream circuit. The power unit includes a first accumulator 8, a rigid liquid tank 19, a high-pressure oil circuit 1, a high-pressure oil circuit 2, a low-pressure oil circuit, a control oil circuit, a return oil circuit 1, a return oil circuit 2, and a return oil circuit 3. The high-pressure oil circuit 1 is connected to the first accumulator 8 via a first check valve 7 to fill it with liquid. The first accumulator 8 is connected to the inlet of the servo valve 10 via a second check valve 9, thereby providing working pressure oil to the servo valve 10. The high-pressure oil circuit 2 is connected to the rigid liquid tank 19 sequentially via a pressure reducing valve 22 and a third check valve 20 to maintain the base pressure within the rigid liquid tank 19. The fluid tank 19 and the high-pressure side of the volume compensation cylinder 17 are connected to form an energy storage cavity. The energy storage cavity is configured to receive and store the pressurized oil energy when the piston of the volume compensation cylinder 17 is pushed by an external force; when the external force is removed, the stored energy and the base pressure are used to push the piston of the volume compensation cylinder 17 to reset; the low-pressure oil circuit is connected to the volume compensation cylinder 17 to maintain the pressure balance on the low-pressure side; the return oil circuit 1 is connected to the outlet of the overflow valve 13; the return oil circuit 2 is connected to the return oil port of the pressure reducing valve 22; and the return oil circuit 3 is connected to the low-pressure return oil side of the volume compensation cylinder 17. The feedback unit includes a first displacement sensor 6, a second displacement sensor 16, a third displacement sensor 21, a first pressure sensor 14, and a second pressure sensor 18. The first displacement sensor 6 is used to detect the displacement of the hammer rod 1 relative to the eccentric shaft housing 4; the second displacement sensor 16 is installed on the oil circuit switch 15 and is used to detect the position of its valve core; the third displacement sensor 21 is installed on the volume compensation cylinder 17 and is used to detect its piston stroke; the first pressure sensor 14 is connected to the low-pressure oil circuit and is used to monitor the pressure on the low-pressure return oil side of the volume compensation cylinder 17; the second pressure sensor 18 is connected to the high-pressure energy storage side of the volume compensation cylinder 17 and is used to monitor the pressure on the high-pressure energy storage side. The control unit contains a programmable controller, which controls the operation of each component based on feedback signals.

[0022] System operation control process I. Control Unit Logic Settings: The control unit is configured to control the action of the hammer rod 1 based on the relative position logic between the forging die 23 and the workpiece. The control unit divides a complete forging cycle into a pressing section and a return section. The control unit identifies the process from the moment the forging die 23 contacts the workpiece, through pressing to the bottom, until it completely leaves the workpiece as the actual forging stage. The process before the forging die 23 contacts the workpiece in the pressing section is identified as the no-load pressing section, and the process after the forging die 23 leaves the workpiece in the return section is identified as the no-load return section. The control unit detects the stroke position of the hammer rod 1 through the first displacement sensor 6 and determines whether to enter the actual forging stage based on the preset stroke position corresponding to the workpiece contact.

[0023] The control system reduces the forging frequency by periodically alternating between effective forging and dry forging. The specific adjustment process includes dry forging control and recovery forging control. The frequency control strategy is that the control system operates in a cyclical mode of "performing one effective forging and then continuously performing n-1 dry forgings" to reduce the actual forging frequency to 1 / n of the original frequency, where n is an integer greater than 1 and is set by the operation interface or automatically by the control system according to the process parameters.

[0024] II. Dry-firing control process: The process of not effectively forging the workpiece during a forging cycle includes the following steps: When the first displacement sensor 6 detects that the hammer rod 1 has reached the preset maximum extension position, the controller commands the working chamber of the return cylinder 5 to be filled with pressurized oil to perform the return action.

[0025] When the first displacement sensor 6 detects that the hammer rod 1 is in the return state, and the distance between the forging die 23 and the workpiece calculated based on the hammer rod displacement is greater than the non-contact gap threshold δ preset according to the process requirements, the controller instructs the servo valve 10 to switch to the left position, connecting the P port and the B port. Pressure oil enters the opening control chamber of the oil circuit switch 15, driving the oil circuit switch 15 to open, connecting the main sealed cavity and the volume compensation cylinder 17. At this time, the return cylinder 5 continuously pushes the hammer rod 1 to retract, discharging the oil in the main sealed cavity into the volume compensation cylinder 17 for storage. Simultaneously, the piston of the volume compensation cylinder 17 moves to the right, compressing the oil on its high-pressure side, increasing the pressure in the energy storage cavity between the rigid liquid tank 19 and the volume compensation cylinder 17. The second pressure sensor 18 feeds back this pressure data to the control unit in real time.

[0026] When the first displacement sensor 6 detects that the retraction amount of the hammer rod 1 reaches the preset dry-firing retraction amount h0, the controller commands the servo valve 10 to switch to the right position, so that the P port is connected to the A port, the pressure oil enters the closing control chamber of the oil circuit switch 15, drives the oil circuit switch 15 to close, cuts off the connection between the main sealed cavity and the volume compensation cylinder 17, and locks the oil in the volume compensation cylinder 17.

[0027] When the second displacement sensor 16 detects that the valve core has been fully reset and confirms that the oil circuit switch 15 is fully closed, the controller commands the servo valve 10 to switch to the neutral position and supplies oil to the closing control chamber of the oil circuit switch 15 through the control oil circuit and the damper 12 to compensate for the pressure loss caused by the seal leakage and maintain its closed state.

[0028] Based on the feedback signals from the first pressure sensor 14 and the second pressure sensor 18, the controller adjusts the pressure balance on both sides of the volume compensation cylinder 17 through the low-pressure oil circuit, and uses the third displacement sensor 21 to monitor the piston position in real time to ensure the stability of the stored oil volume.

[0029] After completing the above steps, in the next cycle of pressing down, when the hammer rod 1 extends to the maximum stroke position under the drive of the main drive mechanism, since the total sealed cavity volume has not recovered to the volume required for effective forging, the forging die 23 and the workpiece remain in a non-contact state, thus achieving dry forging in this cycle.

[0030] III. Restoring an effective forging control process: The process of restoring effective forging of the workpiece in the next forging cycle includes the following steps: During the return stroke of the dry-firing cycle, when the controller determines that the recovery condition is met and the distance between the forging die 23 and the workpiece calculated based on the hammer rod displacement is greater than the non-contact gap threshold δ preset according to the process requirements, the controller instructs the servo valve 10 to switch to the left position, connecting the P port and the B port, driving the oil circuit switch 15 to open, connecting the main sealed cavity and the volume compensation cylinder 17. At this time, under the pressure of the energy storage cavity formed by the rigid liquid tank 19 and the volume compensation cylinder 17, the piston of the volume compensation cylinder 17 moves to the left, quickly refilling the oil stored in the storage cavity into the main sealed cavity through the opened oil circuit switch 15, pushing the hammer rod 1 to extend outward.

[0031] When the first displacement sensor 6 detects that the hammer rod 1 extends to the target position corresponding to the preset forging reduction amount h, the controller commands the servo valve 10 to switch to the right position, so that the P port is connected to the A port, and drives the oil circuit switch 15 to close, cutting off the connection between the main sealed cavity and the volume compensation cylinder 17.

[0032] Once the second displacement sensor 16 confirms that the oil circuit switch 15 is completely closed, the controller instructs the servo valve 10 to switch to the neutral position and supplies oil to the control chamber of the oil circuit switch 15 through the damper 12 via the control oil circuit to maintain its closed state.

[0033] Based on the feedback signals from the first pressure sensor 14 and the second pressure sensor 18, the controller adjusts the pressure balance on both sides of the volume compensation cylinder 17 through the low-pressure oil circuit, so that the volume compensation cylinder 17 returns to its initial energy storage state, and uses the third displacement sensor 21 to monitor its piston position to ensure system stability and prepare for the next dry-firing cycle.

[0034] After completing the above steps, in the next cycle of pressing down, the hammer rod 1 extends normally under the drive of the eccentric shaft, so that the pressing amount of the forging die 23 on the workpiece reaches the preset value h, realizing effective forging in this cycle.

[0035] The contents not described in detail in this specification are existing technologies known to those skilled in the art. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hydraulic control system for a radial forging mill based on volume regulation, comprising a hammer unit, a volume regulation unit, a pressure control unit, a power unit, a feedback unit, and a control unit; Its features are: The hammer unit includes a hammer rod (1), a cylinder (2), an end cap (3), an eccentric shaft housing (4), and a return cylinder (5). The cylinder (2) is fixedly disposed inside the eccentric shaft housing (4), the end cap (3) is slidably disposed inside the cylinder (2), and the hammer rod (1) is slidably disposed inside the cylinder (2). Seals are provided between the hammer rod (1) and the cylinder (2), and between the end cap (3) and the cylinder (2), respectively, so that the hammer rod (1), the cylinder (2), and the end cap (3) are connected. Together they form a total sealed cavity, which includes a chamber between the hammer rod (1) and the cylinder (2) and a chamber between the hammer rod (1) and the end cover (3), and the two chambers are connected to each other through an oil passage opened inside the hammer rod (1); the eccentric shaft housing (4) is provided with an inlet and outlet oil passage that communicates with the total sealed cavity; the return cylinder (5) is a plunger cylinder set on the eccentric shaft housing (4), which maintains close contact with the hammer rod (1) under the pressure of the working chamber to apply force; The volume regulating unit includes an oil circuit switch (15) and a volume compensation cylinder (17); the oil circuit switch (15) is a hydraulic on / off valve with an opening control chamber and a closing control chamber, which is installed on the oil circuit connecting the volume compensation cylinder (17) and the total sealed cavity, and is used to control the opening and closing of the oil circuit between the two; the volume compensation cylinder (17) includes a main piston, a piston rod and a cylinder body, the main piston and the cylinder body enclose a storage cavity for receiving or discharging working oil, and the storage cavity is connected to the total sealed cavity; one end of the piston rod is pressed against the main piston under the pressure of the C cavity, and the other end It extends into the C-cavity formed on the right side of the cylinder and serves as the piston of the C-cavity; the C-cavity is connected to the rigid liquid tank (19) through the oil circuit to form a high-pressure energy storage side; when the hammer rod (1) retracts under the push of the return oil cylinder (5), if the oil circuit switch (15) is opened, the oil in the total sealed cavity flows into the storage cavity of the volume compensation cylinder (17), pushes the main piston to move, and then pushes the piston rod to compress the oil on the high-pressure energy storage side for energy storage; when the hammer rod (1) needs to extend, the high-pressure energy storage side releases energy to push the piston rod and the main piston to reset, and the oil in the storage cavity is returned to the total sealed cavity through the opened oil circuit switch (15); The pressure control unit includes a servo valve (10), a damper (12), a relief valve (13), a pressure reducing valve (22), and a second accumulator (11). The output end of the servo valve (10) is connected to the control chamber of the oil circuit switch (15) via an oil circuit, and is used to control its opening and closing. The damper (12) is installed on the pipeline between the control oil circuit and the closing control chamber of the oil circuit switch (15). When the servo valve (10) is in the neutral position, the pressure oil in the control oil circuit is allowed to slowly flow into the closing control chamber through the damper (12) to compensate for the leakage caused by the seal. The pressure loss is reduced to maintain the reliable closed state of the oil circuit switch (15); the overflow valve (13) is connected between the control chamber of the oil circuit switch (15) and the return oil circuit 1, and is used to control the pressure of the control chamber; the second accumulator (11) is connected to both the return oil end of the servo valve (10) and the return oil port of the overflow valve (13), and is used to absorb pressure shocks and stabilize the return oil pressure; the pressure reducing valve (22) is connected to the high-pressure side oil circuit of the volume compensation cylinder (17), and is used to reduce the pressure of the high-pressure oil circuit 2 to the working pressure required by the downstream circuit; The power unit includes a first accumulator (8), a rigid liquid tank (19), and high-pressure oil circuit 1, high-pressure oil circuit 2, low-pressure oil circuit, control oil circuit, return oil circuit 1, return oil circuit 2, and return oil circuit 3. The high-pressure oil circuit 1 is connected to the first accumulator (8) through a first check valve (7) to fill it with liquid. The first accumulator (8) is connected to the inlet of the servo valve (10) through a second check valve (9) to provide working pressure oil to the servo valve (10). The high-pressure oil circuit 2 is connected to the rigid liquid tank (19) in sequence through the pressure reducing valve (22) and the third check valve (20) to maintain the basic pressure in the rigid liquid tank (19). Force; the rigid liquid tank (19) is connected to the high-pressure side of the volume compensation cylinder (17) to form an energy storage cavity, which is configured to: receive and store the pressed-in oil energy when the piston of the volume compensation cylinder (17) is pushed by an external force; when the external force is removed, the stored energy and the base pressure are used to push the piston of the volume compensation cylinder (17) to reset; the low-pressure oil circuit is connected to the volume compensation cylinder (17) to maintain the low-pressure side pressure balance; the return oil circuit 1 is connected to the outlet of the overflow valve (13); the return oil circuit 2 is connected to the return oil port of the pressure reducing valve (22); the return oil circuit 3 is connected to the low-pressure return oil side of the volume compensation cylinder (17); The feedback unit includes a first displacement sensor (6), a second displacement sensor (16), a third displacement sensor (21), a first pressure sensor (14), and a second pressure sensor (18). The first displacement sensor (6) is used to detect the displacement of the hammer rod (1) relative to the eccentric shaft box (4). The second displacement sensor (16) is installed on the oil circuit switch (15) and is used to detect the position of its valve core. The third displacement sensor (21) is installed on the volume compensation cylinder (17) to detect its piston stroke; the first pressure sensor (14) is connected to the low-pressure oil circuit to monitor the pressure on the low-pressure return oil side of the volume compensation cylinder (17); the second pressure sensor (18) is connected to the high-pressure energy storage side of the volume compensation cylinder (17) to monitor the pressure on the high-pressure energy storage side. The control unit includes a programmable controller for controlling the operation of each component based on feedback signals.

2. The hydraulic control system for a radial forging machine based on volumetric adjustment according to claim 1, characterized in that: The control unit is configured to control the action of the hammer rod (1) based on the relative position logic between the forging die (23) and the workpiece; the control unit divides a complete forging cycle into a pressing section and a return section; the control unit identifies the process of the forging die (23) from contacting the workpiece, pressing down to the bottom, until it completely leaves the workpiece as the actual forging stage; the process before the forging die (23) contacts the workpiece in the pressing section is identified as the unloaded pressing section, and the process after the forging die (23) leaves the workpiece in the return section is identified as the unloaded return section; the control unit detects the stroke position of the hammer rod (1) through the first displacement sensor (6) and determines whether to enter the actual forging stage by combining the preset workpiece contact stroke position.

3. A method for adjusting the forging frequency of a radial forging mill, employing the hydraulic control system based on volume adjustment for the radial forging mill as described in claim 1, characterized in that: The control system reduces the forging frequency by periodically alternating between effective forging and dry forging; the specific adjustment process includes: Dry-firing control: During the dry-firing return section of the previous forging cycle and the dry-firing pressing section of the current forging cycle, the hammer rod (1) is controlled to retract, so that the forging die (23) and the workpiece remain in a non-contact state and the workpiece is not effectively forged. Restoring forging control: During the empty return phase of the empty forging cycle and the empty pressing phase of the next forging cycle, the stored oil is injected into the total sealed cavity through the volume compensation cylinder (17) via the opened oil circuit switch (15), pushing the hammer rod (1) to extend, so that the pressing amount of the forging die (23) on the workpiece is restored to the preset pressing amount corresponding to the forging process, thereby restoring effective forging; Frequency control strategy: The control system operates in a cyclic mode of "performing one effective forging and then performing (n-1) consecutive dry forgings", reducing the actual forging frequency to 1 / n of the original frequency, where n is an integer greater than 1, and n is set by the operation interface or automatically set by the control system according to the process parameters.

4. The method for adjusting the forging frequency of a radial forging mill according to claim 3, characterized in that, The process of not performing effective forging (i.e., dry forging) on ​​the workpiece during a forging cycle includes the following steps: When the first displacement sensor (6) detects that the hammer rod (1) has reached the preset maximum extension position, the controller commands the return cylinder (5) to perform the return action; When the first displacement sensor (6) detects that the hammer rod (1) is in the return state, and the distance between the forging die (23) and the workpiece calculated based on the hammer rod displacement is greater than the non-contact gap threshold δ preset according to the process requirements, the controller commands the servo valve (10) to switch to the left position, so that the P port and the B port are connected, and the oil circuit switch (15) is opened to connect the main sealed cavity and the volume compensation cylinder (17); at this time, the return cylinder (5) pushes the hammer rod (1) to retract, and discharges the oil in the main sealed cavity into the volume compensation cylinder (17) for storage. At the same time, the piston of the volume compensation cylinder (17) moves to the right, compressing the oil on its high-pressure side, so that the pressure of the energy storage cavity between the rigid liquid tank (19) and the volume compensation cylinder (17) increases. When the first displacement sensor (6) detects that the retraction amount of the hammer rod (1) reaches the preset dry retraction amount h0, the controller commands the servo valve (10) to switch to the right position, so that the P port is connected to the A port, and drives the oil circuit switch (15) to close, cutting off the connection between the main sealed cavity and the volume compensation cylinder (17). When the second displacement sensor (16) confirms that the oil circuit switch (15) is completely closed, the controller commands the servo valve (10) to switch to the neutral position and supplies oil to the control chamber of the oil circuit switch (15) through the control oil circuit via the damper (12) to maintain its closed state; The controller adjusts the pressure balance on both sides of the volume compensation cylinder (17) through the low-pressure oil circuit based on the feedback signals from the first pressure sensor (14) and the second pressure sensor (18), and monitors the piston position using the third displacement sensor (21) to ensure the stability of the stored oil volume. After completing the above steps, in the next cycle of pressing down, when the hammer rod (1) extends to the maximum stroke position, the forging die (23) and the workpiece remain in a non-contact state, realizing dry pressing in this cycle.

5. The method for adjusting the forging frequency of a radial forging mill according to claim 3, characterized in that, The process of restoring effective forging of the workpiece in the next forging cycle includes the following steps: When the first displacement sensor (6) detects that the hammer rod (1) has reached the preset maximum extension position, the controller commands the return cylinder (5) to perform the return action; When the first displacement sensor (6) detects that the hammer rod (1) is in the return state, and the distance between the forging die (23) and the workpiece calculated based on the hammer rod displacement is greater than the non-contact gap threshold δ preset according to the process requirements, the controller commands the servo valve (10) to switch to the left position, so that the P port and the B port are connected, and the oil circuit switch (15) is opened to connect the total sealed cavity and the volume compensation cylinder (17); at this time, under the pressure of the energy storage cavity formed by the rigid liquid tank (19) and the volume compensation cylinder (17), the volume compensation cylinder (17) refills the oil stored in it into the total sealed cavity through the oil circuit switch (15), pushing the hammer rod (1) to extend outward; When the first displacement sensor (6) detects that the hammer rod (1) extends to the target position corresponding to the preset forging reduction amount h, the controller commands the servo valve (10) to switch to the right position, so that the P port and the A port are connected, and the drive oil circuit switch (15) is closed, cutting off the connection between the total sealed cavity and the volume compensation cylinder (17). When the second displacement sensor (16) confirms that the oil circuit switch (15) is completely closed, the controller commands the servo valve (10) to switch to the neutral position and supplies oil to the control chamber of the oil circuit switch (15) through the control oil circuit via the damper (12) to maintain its closed state; The controller adjusts the pressure balance on both sides of the volume compensation cylinder (17) through the low-pressure oil circuit based on the feedback signals from the first pressure sensor (14) and the second pressure sensor (18), and monitors the piston position using the third displacement sensor (21) to ensure system stability. After completing the above steps, in the next cycle of pressing down, when the hammer rod (1) extends to the maximum stroke position, the forging die (23) presses down on the workpiece to the preset value h, thus realizing effective forging in this cycle.

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