A control method and system for a wire-wound motor rotor bar forming machine

Abstract

This invention relates to the field of motor rotor copper busbar processing technology, and discloses a control method and system for a wound-rotor rotor bar forming machine. The method includes: setting parameters such as the straight length of the bar, bending angle, initial end length, and rotor center position; adjusting the straight spacing, end position, and R-block size of the clamping plates; determining the pressure level and selecting a target pressure value; applying reverse balancing oil pressure through a pressure reducing valve to adjust part of the tensile force; controlling the clamping plates to clamp the bar, and then driving the first and second swing arms to rotate; collecting the angle values ​​of the first and second swing arms; when the angle value reaches the bending angle, controlling the power source to stop, and the first and second top-arc components cooperate to bend the bar into a motor rotor bar; after bending, driving the first and second swing arms to move outward and removing the bar. This application improves the equipment adjustment efficiency and bending angle accuracy.

Description

Technical Field

[0001] This invention relates to the field of motor rotor copper busbar processing technology, and more specifically, to a control method and system for a wound-rotor rotor bar forming machine. Background Technology

[0002] Wound-rotor motors are widely used in large motors, power generation equipment, and high-voltage motor systems. Their rotor windings typically consist of multiple bars with specific bending structures. Before being installed into the rotor slots, these bars need to be precisely bent according to design requirements to form motor rotor bars that meet assembly dimensions and spatial structure requirements. Therefore, during motor manufacturing, specialized bar bending equipment is usually required to bend the straight bars to improve production efficiency and ensure product consistency.

[0003] The existing technology CN118253656A discloses an automated motor rotor bar bending machine, which includes a base, multiple slides, and swing arms and fixed arms respectively mounted on the slides. The bar is clamped by clamping plates, and bending force is applied to the bar using the cooperation of the swing arms and the top arc component, causing the bar to form a bent structure at a set angle. Parameters such as the bar's straight length, bending angle, and end starting length are set via an operating table, thereby enabling bending of bars of different specifications. It is also equipped with encoders, straight rulers, and sensors to monitor the equipment's operating status and assist in the automated bending operation. However, in practical applications, the aforementioned automated motor rotor bar bending machine still has certain shortcomings. During the bending process, the bar experiences significant tensile force and springback due to the bending force. Since it is mostly driven by fixed hydraulic pressure, it lacks a control method that adaptively adjusts the hydraulic pressure according to the bar's cross-sectional specifications or bending state, which can easily lead to insufficient bending angle accuracy or poor forming stability. During the bending process of bar, the control of the swing arm rotation angle usually relies on a single detection signal or a simple angle setting. When the detection device has errors or abnormalities, it is difficult to check and correct them in time, which may affect the accuracy of the bending angle and the safety of equipment operation.

[0004] Therefore, it is necessary to design a control method and system for a wound-rotor bar forming machine for a wound-rotor motor to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes a control method and system for a wound-rotor bar forming machine for a motor rotor, which aims to solve the problems that easily lead to insufficient bending angle accuracy or poor forming stability, and that it is difficult to timely check and correct errors or abnormalities in the detection device.

[0006] In one aspect, the present invention provides a control method for a wound-rotor bar forming machine for a wound-rotor motor, comprising: Set the straight length of the wire bar, bending angle, end starting length, and rotor center position parameters; and control the drive mechanism to move the first slide, second slide, third slide, and fourth slide, and adjust the straight spacing, end position, and R-block size of the clamping point of the clamping plates; Based on the cross-sectional specifications corresponding to the straight length of the bar, determine the pressure level and select the target pressure value; turn on the oil pump hydraulic system, and apply reverse balance oil pressure to the hydraulic mechanism that drives the first and second swing arms to flip through the pressure reducing valve, and adjust the reverse balance oil pressure to offset part of the tensile force generated during the bending process of the bar; After the clamping plate clamps the bar, the power source drives the first and second swing arms to rotate relative to the base. The angle values ​​of the first and second swing arms are collected by the hollow rotary encoder and the base shaft encoder. When the angle value reaches the bending angle, the power source is stopped and the first and second top arc components work together to bend the bar into a motor rotor bar. After bending is completed, the control clamp is released, driving the first and second swing arms to move outward and remove the wire rod.

[0007] Furthermore, when the control drive mechanism moves the first slide, second slide, third slide, and fourth slide, it includes: Based on the rotor center position parameters, the target displacements of the first slide, second slide, third slide, and fourth slide are determined; the four servo motors are controlled to start simultaneously according to a preset synchronization ratio, driving their respective ball screws to rotate.

[0008] Furthermore, when driving the respective ball screws to rotate, it includes: During rotation, the position feedback of the four slides is monitored in real time. When the position deviation between any two slides exceeds the allowable tolerance, the movement is paused and the position is corrected.

[0009] Furthermore, when determining the pressure level and selecting the target pressure value, the following steps are included: The pressure ratings include high pressure ratings, medium pressure ratings, and low pressure ratings. Obtain the cross-sectional area data of the current bar, and compare the cross-sectional area data with an area threshold; the area threshold includes a first area threshold and a second area threshold; the first area threshold is greater than the second area threshold; When the cross-sectional area is greater than the first area threshold, the high pressure level is selected; when the cross-sectional area is less than or equal to the first area threshold and greater than the second area threshold, the medium pressure level is selected; when the cross-sectional area is less than or equal to the second area threshold, the low pressure level is selected.

[0010] Furthermore, determining the pressure level and selecting the target pressure value also includes: The reference oil pressure value corresponding to the selected pressure level is used as the target pressure value, and the first and second swing arms are driven by the output of the pressure reducing valve.

[0011] Furthermore, adjusting the reverse balancing oil pressure to counteract part of the tensile force generated during the bending of the wire bar includes: During the rotation of the first and second swing arms, the angle value collected by the hollow rotary encoder is obtained; based on the angle value, the change in tensile force caused by the change in eccentricity during the bending of the wire bar is determined; based on the change in tensile force, the pressure value of the reverse balancing oil pressure is adjusted.

[0012] Furthermore, when collecting the angle values ​​of the first and second swing arms, the following is included: The system synchronously reads the first angle data of the hollow rotary encoder and the second angle data of the base shaft encoder; determines the deviation value between the first angle data and the second angle data; when the deviation value is greater than a preset fault tolerance threshold, it determines that the angle acquisition system is abnormal, immediately controls the power source to stop and outputs a fault alarm signal; when the deviation value is less than or equal to the fault tolerance threshold, it takes the average value of the first angle data and the second angle data as the angle value.

[0013] Furthermore, it also includes: During the bending process, the extreme position is monitored by the origin sensor and the cylinder sensor. When the angle value is greater than the bending angle and reaches the preset safety threshold, the power source is cut off.

[0014] Furthermore, it also includes: Record the actual angle value, target pressure value, and bending completion time for each bending process to form a historical process database; when processing the same cross-sectional bar again, call the parameters in the historical process database as the initial setting value.

[0015] Compared with existing technologies, the advantages of this invention are as follows: During the bending process, a pressure reducing valve applies reverse balancing oil pressure to the hydraulic mechanism driving the first and second swing arms. This pressure is categorized into high, medium, and low pressure levels based on the bar cross-section specifications, ensuring that the applied thrust can offset most of the tensile force generated during bending. This allows the bar to move towards the center with only a small pulling force, avoiding bar bowing or thinning due to unstable swing arm movement speed, thus improving the stability and yield of the bending process. Furthermore, the hollow rotary encoder and base shaft encoder collect real-time angle data of the first and second swing arms, and control the start and stop of the power source based on the angle values. This enables digital control of the swing arm bending angle, allowing direct setting of the bending angle on the control interface. This facilitates rapid and accurate parameter adjustment, improving equipment adjustment efficiency and bending angle accuracy. Deviation verification is performed using dual-angle data from a hollow rotary encoder and a base shaft encoder. When the detected angle data deviation exceeds a preset threshold, the power source is stopped and an alarm signal is issued in a timely manner. Simultaneously, a point sensor and limit switches serve as ultimate safety protection, forming a multi-level safety protection mechanism to prevent equipment malfunction or structural damage. Four servo motors drive the first, second, third, and fourth slides respectively, and real-time position feedback detects and corrects slide position deviations, enabling each slide to move synchronously according to a set ratio. This achieves automated adjustment of the bar's straight length, end position, and clamping spacing, improving the equipment's adaptability to different specifications of bar. The bending mechanism forms a stable force-bearing structure through the first swing arm, first fixed arm, second fixed arm, and second swing arm, concentrating the force points of each working arm at the root of the arm. This effectively withstands the torsional load, reverse jacking force, and bending force generated during bar bending, improving the overall structural stability and load-bearing capacity of the equipment. By recording the actual angle value, target pressure value, and bending completion time during each bending process and forming a historical process database, the corresponding parameters can be automatically called as initial settings when processing the same specification bar again. This reduces equipment debugging time, improves production efficiency, and gradually optimizes bending process parameters.

[0016] On the other hand, this application also provides a control system for a wound-rotor bar forming machine for a wound-rotor motor, for applying the above-described control method for a wound-rotor bar forming machine, including: The setting module is configured to set the straight length of the bar, bending angle, end starting length and rotor center position parameters; and control the drive mechanism to move the first slide, second slide, third slide and fourth slide, and adjust the straight spacing, end position and clamping R block size of the clamping plates; The first adjustment module is configured to determine the pressure level and select the target pressure value according to the cross-sectional specifications corresponding to the straight length of the bar; to start the oil pump hydraulic system and apply reverse balance oil pressure to the hydraulic mechanism that drives the first swing arm and the second swing arm to flip through the pressure reducing valve, and to adjust the reverse balance oil pressure to offset part of the tensile force generated during the bending process of the bar; The second adjustment module is configured to control the clamping plate to clamp the bar, and then drive the first and second swing arms to rotate relative to the base via a power source; collect the angle values ​​of the first and second swing arms via a hollow rotary encoder and a base shaft encoder; when the angle value reaches the bending angle, control the power source to stop, and the first and second top arc components cooperate to bend the bar into a motor rotor bar. The production module is configured to release the control clamp after bending, drive the first and second swing arms to move outward and remove the wire bar.

[0017] It is understandable that the control methods and systems described above for wound-rotor bar forming machines for motors have the same beneficial effects, and will not be elaborated further here. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of a control method for a wound-rotor bar forming machine for a wound-rotor motor provided in an embodiment of the present invention; Figure 2 This is a functional block diagram of a control system for a wound-rotor bar forming machine for a wound-rotor motor, provided in an embodiment of the present invention. Detailed Implementation

[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] In some embodiments of this application, see Figure 1 As shown, a control method for a wound-rotor bar forming machine for a wound-rotor motor is proposed, including: S100: Sets the straight length, bending angle, end starting length, and rotor center position parameters of the wire bar; and controls the drive mechanism to move the first slide, second slide, third slide, and fourth slide, and adjusts the straight spacing, end position, and R-block size of the clamping point of the clamping plate; S200: Determine the pressure level and select the target pressure value according to the cross-sectional specifications corresponding to the straight length of the bar; turn on the oil pump hydraulic system, and apply reverse balance oil pressure to the hydraulic mechanism that drives the first swing arm and the second swing arm to flip through the pressure reducing valve, and adjust the reverse balance oil pressure to offset part of the tensile force generated during the bending process of the bar; S300: After the control clamping plate clamps the bar, the power source drives the first swing arm and the second swing arm to rotate relative to the base; the hollow rotary encoder and the base shaft encoder collect the angle values ​​of the first swing arm and the second swing arm; when the angle value reaches the bending angle, the power source is controlled to stop, and the first top arc component and the second top arc component cooperate to bend the bar into a motor rotor bar. S400: After bending is completed, the control clamp is released, the first and second swing arms are driven to move outward and the wire bar is removed.

[0021] Specifically, this application addresses the control method for the automated motor rotor bar bending machine disclosed in CN118253656A. In this machine, the bar experiences significant tensile force and springback during bending. However, it typically uses fixed hydraulic pressure for drive, lacking a control method that adaptively adjusts the hydraulic pressure based on the bar's cross-sectional specifications or bending state. This can easily lead to insufficient bending angle accuracy or poor forming stability. Furthermore, the control of the swing arm's tilting angle during bar bending usually relies on a single detection signal or a simple angle setting. When the detection device malfunctions or malfunctions, timely verification and correction are difficult.

[0022] Specifically, during the rotor bar forming process, the two ends of the bar need to form a bending angle of approximately 45° to 60°. As the swing arm drives the bar to gradually bend, as the swing angle gradually increases from 0° to 30°, 45°, and finally 60°, the spatial position of the two ends of the bar will continuously shrink towards the rotor center, and its horizontal projected length will gradually decrease. During this process, due to the eccentricity between the rotation center of the swing arm and the force point of the bar, the tensile force generated by the bar will continuously increase as the swing angle increases. In the existing technology, the hydraulic pressure in both chambers of the drive cylinder is usually released to zero pressure, so that the swing arm moves towards the center by relying on the tension of the bar itself during the bending process. Since this movement process depends entirely on the tension of the bar, its movement speed is unstable and fluctuates. When the movement speed is too fast, the bar will undergo bow-shaped deformation during the bending process, resulting in the scrap of the workpiece; while when the movement speed is too slow, for bar with a small cross-sectional area, its tensile strength is insufficient, which may lead to thinning or even breakage of the bar cross-section during the stretching process, thus also causing processing failure. This application is for the purpose of achieving control in order to solve the aforementioned problems.

[0023] Specifically, if a conventional hydraulic cylinder is used to actively push the swing arm towards the center, the oil pressure will fluctuate with the load. Since the larger the swing angle of the swing arm, the greater the required driving force, it is difficult to maintain stable control of the cylinder's output thrust, thus making it difficult to guarantee the stability of the swing arm's movement speed. To solve this problem, this invention introduces a reverse balance thrust control structure into the swing arm drive hydraulic system. Specifically, a preset oil pressure is applied to the hydraulic mechanism driving the swing arm through a pressure reducing valve. This oil pressure forms an auxiliary thrust, the magnitude of which is graded according to the cross-sectional specifications of the bar, for example, set to three thrust levels: large, medium, and small. This auxiliary thrust is used to offset most of the tensile force generated during the bending process of the bar, but its thrust value is precisely controlled within a range insufficient to actively push the swing arm to move. In this state, the actual movement of the swing arm is still driven by the tension of the bar, but since the hydraulic system has offset most of the tensile load, the bar only needs a smaller tension to drive the swing arm to move, thus making the swing arm movement smoother. This structure is similar to a counterweight balancing structure in a mechanical system. By balancing the forces, the motion mechanism is kept in a light-load operating state, which effectively avoids the problem of bow-shaped deformation or thinning and breakage of the wire rod during bending, and greatly improves the forming stability.

[0024] Specifically, in terms of swing arm bending angle control, this invention adopts a digital angle control method to replace the traditional mechanical limit control method. In traditional equipment, swing arm angle control is usually achieved by setting a mechanical stop and using a limit switch. When the swing arm touches the limit stop, the limit switch sends a signal to stop the power source. However, this method has problems such as low positioning accuracy, difficulty in adjustment, and long adjustment time when changing to different specifications of rotor bars. To address this, this invention sets an angle encoder at the swing arm shaft, which collects the rotation angle data of the swing arm in real time and transmits this data to the CNC control system. The control system then controls the start and stop of the power source according to the set bending angle value, thereby achieving precise positioning of the swing arm. Operators only need to input the target bending angle on the control interface to complete the angle setting, which can quickly adapt to different specifications of rotor bars, improving equipment adjustment efficiency and positioning accuracy.

[0025] Specifically, to ensure equipment operational safety, mechanical stops and limit switches are retained as the ultimate safety protection structure in addition to the digital control system. Under normal operating conditions, the angle control of the swing arm is completed by the encoder and CNC system. Under CNC control, the rotation angle moves towards the center; when it reaches the target position, the mechanical stop, which was originally located at a distance, is adjusted to a position with a clearance of approximately 0.2mm to 0.3mm from the CNC position, serving as an auxiliary limit structure. Without CNC positioning, and relying solely on limit switches for positioning, positioning is difficult, the adjustment time is long, and it is not easy to control. When the CNC system malfunctions, the swing arm can still achieve secondary safety protection through the mechanical stop and limit switches, thereby preventing equipment damage. Furthermore, in the structural design of this invention, the main stress points of the four working arms are all located at the root of the swing arm, so that the various forces generated during the bending and forming of the rotor bar, including the torsional load of the bar, the reaction force generated by bending downward at both ends, and the top pressure generated during arc forming, are all borne and transmitted by the root of the swing arm, thereby significantly improving the overall structural stability and load-bearing capacity of the mechanism, enabling the equipment to maintain stable output and good structural rigidity during operation.

[0026] Specifically, regarding equipment parameter adjustment, this invention utilizes a servo motor in conjunction with a ball screw transmission mechanism to achieve vertical adjustment control of the rotor's center position. The operator can input the target center position through the CNC system, and the servo motor drives the ball screw to move the mechanism up and down along the guide rail, thereby achieving precise adjustment of the rotor's center height. Compared to traditional equipment that uses manual cranks or trapezoidal slot structures for manual adjustment and bolt locking, this invention's CNC adjustment method offers advantages such as high adjustment accuracy, fast adjustment speed, and convenient operation. Furthermore, an adjustable R-block structure is incorporated into the clamping mechanism, allowing the clamping area to adapt to variations in the arc dimensions of rotor bars of different specifications. By adjusting the R-block size, the ends of the bar can be bent to match the rotor's center arc, ensuring the machining accuracy of rotors of different specifications.

[0027] Specifically, in step S100, the forming parameters are initialized. This involves setting the straight bar length, bending angle, end starting length, and rotor center position parameters in the control system based on the design structure of the motor rotor to be processed. The straight bar length determines the length of the straight segments on both sides of the bar; the bending angle determines the target forming angle of the bent segment; the end starting length determines the position of the bar end relative to the bending center; and the rotor center position parameter determines the symmetry of the bending position relative to the equipment center. The control system controls the drive mechanism based on these parameters. The drive mechanism moves the first, second, third, and fourth slides along the guide rail direction, adjusting the straight distance between the clamping plates, the bar end positioning position, and the size matching relationship of the R-block in the clamping area by changing the slide positions. This allows the equipment to adapt to the processing requirements of different specifications of bar and ensures that the bar remains stably positioned within the clamping area.

[0028] In step S200, bending pressure control parameters are determined according to the bar specifications. Specifically, the control system classifies the bar specifications into different pressure levels, such as high pressure, medium pressure, and low pressure, based on the bar cross-sectional specifications (e.g., bar cross-sectional area or cross-sectional shape dimensions) corresponding to the bar straight length parameters, and selects the corresponding target pressure value from a preset pressure database. Then, the hydraulic pump system is started, and the hydraulic oil pressure is adjusted through a pressure reducing valve. The adjusted hydraulic oil is then delivered to the hydraulic mechanism used to drive the first and second swing arms to rotate. The hydraulic mechanism applies a reverse balancing oil pressure to the first and second swing arms. This reverse balancing oil pressure is used to counteract part of the tensile force generated during the bending process, allowing the swing arms to complete the bending action only by overcoming the remaining bending resistance. This maintains the bar in a state of force balance during bending, preventing deformation or cross-sectional damage due to excessive tension.

[0029] In step S300, the bending and forming control of the wire rod is performed. First, the wire rod is clamped by a clamping plate to form a stable fixed state in the bending area. Then, the power source is started, driving the first and second swing arms to rotate inward relative to the base. During the rotation process, the first and second top arc components gradually exert pressure and bending force on the wire rod, causing it to gradually bend around the preset bending center. At the same time, the rotation angle values ​​of the first and second swing arms are collected in real time by a hollow rotary encoder installed at the swing arm shaft and a base shaft encoder installed at the base shaft, and the angle data is fed back to the control system. When the swing arm angle value is detected to reach the preset bending angle, the control system immediately issues a stop signal, causing the power source to stop outputting power, so that the first and second top arc components complete the bending and shaping of the wire rod at the target position, forming a bent shape that meets the requirements of the motor rotor structure.

[0030] In step S400, the resetting and material removal operations are performed after bending is completed. Specifically, the control system first controls the clamping plate to release the bar, causing the bar to disengage from the clamping state; then, it controls the drive mechanism to move the first and second swing arms outward to reset, restoring the bending mechanism to its initial position; after the swing arms are fully reset, the formed rotor bar is removed from the equipment by a manual or automatic material removal mechanism, thus completing one complete bar bending and forming operation cycle.

[0031] Understandably, by coordinating the control of the slide position, bending pressure, and swing arm angle, the reverse balancing hydraulic pressure is used to offset part of the tensile force generated by the bar during the bending process, making the bending force of the bar more stable; and by using an encoder to collect the swing arm angle in real time and perform precise control, the bending angle becomes more accurate and reliable.

[0032] In some embodiments of this application, when the control drive mechanism moves the first slide, the second slide, the third slide, and the fourth slide, it includes: Based on the rotor center position parameters, determine the target displacement of the first slide, second slide, third slide and fourth slide; control the four servo motors to start simultaneously according to the preset synchronization ratio, driving their respective ball screws to rotate.

[0033] In some embodiments of this application, driving the respective ball screws to rotate includes: During rotation, the position feedback of the four slides is monitored in real time. When the position deviation between any two slides exceeds the allowable tolerance, the movement is paused and the position is corrected.

[0034] Specifically, to achieve automated adjustment and precise positioning of each slide in the rotor bar forming machine, when the control drive mechanism moves the first, second, third, and fourth slides, the spatial position of each slide is first calculated based on the rotor center position parameters, bar linear length parameters, and end starting length parameters input from the operating panel. This determines the target displacement of the first, second, third, and fourth slides on the base guide rail. The control system generates corresponding servo control commands based on the calculated target displacement and sends them to the four servo motors, causing them to start simultaneously according to a preset synchronization ratio. Specifically, each servo motor is connected to a corresponding ball screw drive mechanism. When the servo motor starts, it drives the corresponding ball screw to rotate via a coupling, thereby driving the slider mechanism that cooperates with the ball screw to move along the base guide rail, and thus causing the first, second, third, and fourth slides to move linearly on the base. Because ball screw drives have the characteristics of high transmission efficiency, high positioning accuracy and good repeatability, they can achieve precise adjustment of the slide position, so that the straight distance between the four clamps and the starting position of the bending at both ends can accurately correspond to the processing requirements of rotor bar of different specifications.

[0035] Specifically, during the movement of the slide blocks driven by the ball screw rotation, the control system collects the actual position information of the slide blocks in real time through linear displacement detection devices installed on each slide block, and transmits the collected position feedback signals to the control system for data comparison. The control system dynamically adjusts the operating status of the servo motors based on the deviation between the actual position and the target position of each slide block, thereby ensuring that each slide block moves according to a predetermined synchronous ratio. During the movement, the control system continuously monitors the relative positional relationship between the first, second, third, and fourth slide blocks. When the actual positional deviation between any two slide blocks exceeds the preset allowable tolerance range, the control system immediately sends a pause command to the corresponding servo motor, temporarily stopping the movement of the four slide blocks. Simultaneously, the control system calculates the correction amount based on the deviation value of each slide block, correcting the deviation by fine-tuning the speed of the servo motors or making a slight reverse movement, restoring each slide block to the preset synchronous positional relationship. Once the positional deviation of each slide block returns to within the allowable tolerance range, subsequent movement control commands are executed again.

[0036] Understandably, by employing a servo motor to drive the ball screw and combining it with real-time position feedback control, the synchronous automatic adjustment of the first, second, third, and fourth slides is achieved. Furthermore, a position deviation monitoring and automatic correction mechanism is introduced during movement to ensure that each slide maintains a stable synchronous relationship throughout the motion, thereby improving the positioning accuracy and stability of the slide adjustment.

[0037] In some embodiments of this application, determining the pressure level and selecting the target pressure value includes: Pressure ratings include high pressure ratings, medium pressure ratings, and low pressure ratings. Obtain the cross-sectional area data of the current bar and compare the cross-sectional area data with the area threshold; the area threshold includes a first area threshold and a second area threshold; the first area threshold is greater than the second area threshold; When the cross-sectional area is greater than the first area threshold, a high pressure level is selected; when the cross-sectional area is less than or equal to the first area threshold but greater than the second area threshold, a medium pressure level is selected; when the cross-sectional area is less than or equal to the second area threshold, a low pressure level is selected.

[0038] In some embodiments of this application, determining the pressure level and selecting the target pressure value further includes: The reference oil pressure value corresponding to the selected pressure level is used as the target pressure value, and the first and second swing arms are driven by the output of the pressure reducing valve.

[0039] Specifically, the cross-sectional dimensions of the current wire rod can be obtained by pre-inputting the wire rod model parameters or through a detection device, and the corresponding cross-sectional area data can be calculated based on the cross-sectional dimensions. After obtaining the cross-sectional area data, the control system compares the cross-sectional area data with preset area thresholds, which include a first area threshold and a second area threshold, with the first area threshold being greater than the second area threshold. The first and second area thresholds can be obtained based on actual production experience or experimental calibration, and are used to distinguish the auxiliary thrust level required for wire rods of different cross-sectional specifications during bending. When the control system determines that the cross-sectional area is greater than the first area threshold, it indicates that the current wire rod has a large cross-sectional size, and its material strength and tensile strength are relatively high, so it is selected as a high pressure level; when the cross-sectional area is less than or equal to the first area threshold but greater than the second area threshold, it indicates that the wire rod is in the medium cross-sectional specification range, and it is selected as a medium pressure level; when the cross-sectional area is less than or equal to the second area threshold, it indicates that the wire rod cross-section is small, and its tensile strength is relatively low, so it is selected as a low pressure level.

[0040] Specifically, after determining the pressure level, the control system retrieves the reference oil pressure value corresponding to the pressure level from a pre-set pressure parameter table and uses this reference oil pressure value as the target pressure value for this bending process. Subsequently, by controlling the start of the hydraulic pump system, hydraulic oil enters the hydraulic circuit, and the hydraulic oil pressure is regulated by a pressure reducing valve to stabilize the output pressure within the target pressure range. Further, the hydraulic oil regulated by the pressure reducing valve is delivered to the hydraulic mechanism that drives the first and second swing arms to rotate, thus providing a stable reverse balancing oil pressure during the movement of the swing arms. This reverse balancing oil pressure forms an appropriate auxiliary thrust to counteract most of the tensile force generated by the change in eccentricity during the bending process of the bar, but it does not directly drive the swing arms to produce active movement, thus allowing the swing arms to still be mainly driven by the tension of the bar itself. In this way, only a small tension is needed to drive the swing arms during the bending process, while avoiding problems such as bar bending, thinning, or breakage caused by excessively fast swing arm movement or excessive tension.

[0041] Understandably, by automatically determining the pressure level based on the cross-sectional area of ​​the bar and using the pressure reducing valve to output the corresponding target oil pressure as the reverse balancing oil pressure of the swing arm, the hydraulic system can provide appropriate auxiliary thrust to counteract some of the tensile force generated during the bending process of the bar, thereby reducing the pulling force required when the bar drives the swing arm and avoiding the phenomenon of the bar bending or thinning caused by the unstable movement speed of the swing arm.

[0042] In some embodiments of this application, adjusting the reverse balancing oil pressure to counteract part of the tensile force generated during the bending of the wire rod includes: During the rotation of the first and second swing arms, the angle value collected by the hollow rotary encoder is obtained; based on the angle value, the change in tensile force caused by the change in eccentricity during the bending of the wire bar is determined; based on the change in tensile force, the pressure value of the reverse balance oil pressure is adjusted.

[0043] Specifically, during the rotation of the first and second swing arms relative to the base, a hollow rotary encoder located at the swing arm rotation axis collects the angle values ​​of the swing arms in real time and transmits these angle values ​​to the control system for processing. The control system establishes a correspondence between the swing arm rotation angle and the stress state of the bar based on the angle values. Since the ends of the bar need to gradually form a bending angle of approximately 45° to 60° during the bending process, as the swing arm rotates inward from its initial position, the spatial position of the bar end gradually moves towards the rotor center, resulting in a gradual shortening of the effective horizontal projection length of the bar. Simultaneously, due to the eccentricity between the swing arm drive point and the bar stress point, this eccentricity gradually increases with the increase of the swing arm rotation angle, causing the tensile force exerted by the bar on the swing arm to exhibit a non-linear growth trend. During this process, the control system calculates the change in the tensile force of the bar caused by the change in eccentricity at the current bending angle based on the angle values ​​collected by the hollow rotary encoder, combined with a pre-established bending stress model or empirical function relationship. Subsequently, the control system dynamically adjusts the reverse balance oil pressure in the hydraulic system based on changes in tensile force. Specifically, by adjusting the output pressure of the pressure reducing valve, the hydraulic mechanism provides a corresponding amount of auxiliary thrust to the first and second swing arms. When the swing arm angle gradually increases and the corresponding tensile force shows an upward trend, the control system appropriately increases the reverse balance oil pressure, causing the hydraulic mechanism to apply a larger auxiliary thrust to the swing arms to counteract the increasing tension of the bar. When the swing arm is in the initial bending stage and the tensile force is small, a lower reverse balance oil pressure is maintained to prevent excessive hydraulic thrust from directly driving the swing arm movement. In this way, the reverse balance oil pressure is always kept in a state of "near equilibrium but not actively driving," meaning the thrust provided by the hydraulic system can counteract most of the tension of the bar, but the swing arm continues to move inward due to the small tension of the bar itself.

[0044] Understandably, by using a hollow rotary encoder to obtain the swing arm angle in real time during the swing arm's rotation process, and calculating the change in tensile force of the bar due to the change in eccentricity based on the angle change, and then dynamically adjusting the reverse balance oil pressure, the hydraulic system can continuously provide appropriate auxiliary thrust throughout the bending process, thereby offsetting most of the tensile force of the bar and making the swing arm movement more stable.

[0045] In some embodiments of this application, the acquisition of the angle values ​​of the first and second swing arms includes: The system synchronously reads the first angle data from the hollow rotary encoder and the second angle data from the base shaft encoder; determines the deviation between the first and second angle data; when the deviation is greater than the preset fault tolerance threshold, it determines that the angle acquisition system is abnormal, immediately controls the power source to stop and outputs a fault alarm signal; when the deviation is less than or equal to the fault tolerance threshold, it takes the average of the first and second angle data as the angle value.

[0046] Specifically, a hollow rotary encoder is installed at the position of the first swing arm or its rotation axis to detect the rotation angle of the swing arm relative to the drive shaft in real time and output the first angle data. Simultaneously, a base shaft encoder is installed at the position of the main shaft of the base or the swing arm support shaft to detect the rotation angle of the swing arm relative to the base reference shaft and output the second angle data. Both the hollow rotary encoder and the base shaft encoder are electrically connected to the control system, enabling real-time synchronous acquisition of the swing arm angle during the swing arm rotation process. During the swing arm rotation process, the control system synchronously reads the first angle data output by the hollow rotary encoder and the second angle data output by the base shaft encoder according to a preset sampling period, and compares the two sets of angle data in real time to calculate the deviation value between the first angle data and the second angle data. This deviation value reflects the consistency status between the two angle detection systems. The control system further compares the deviation value with a preset fault tolerance threshold. The fault tolerance threshold is a pre-set allowable error range based on factors such as the equipment structural accuracy, encoder measurement accuracy, and mechanical transmission clearance. When the detected deviation exceeds the preset fault tolerance threshold, the control system determines that the angle acquisition system is malfunctioning, such as encoder signal distortion, loose transmission mechanism, sensor failure, or abnormal signal transmission. In this case, a stop control command is immediately sent to the power source, stopping the power source driving the first and second swing arms to rotate. Simultaneously, the control system outputs a fault alarm signal to the operating interface or alarm module to prompt operators to promptly inspect or maintain the equipment, thus preventing problems such as excessive swing arm rotation, bar deformation, or equipment damage caused by abnormal angle detection. When the detected deviation between the first and second angle data is less than or equal to the fault tolerance threshold, it indicates that both angle detection systems are working normally and the detection results are consistent. At this time, the control system fuses the first and second angle data, for example, by calculating their average value, to obtain the final swing arm angle value used for control judgment. Based on the relationship between this angle value and the preset bending angle, the control system controls the start and stop of the power source. When the angle value reaches or approaches the set bending angle, the power source is stopped, thereby achieving precise control of the swing arm bending angle.

[0047] Understandably, by setting up both a hollow rotary encoder and a base shaft encoder to perform dual detection of the swing arm angle and comparing the deviations of the two sets of angle data in real time, the power source is stopped and an alarm signal is issued in a timely manner when the detected deviation exceeds the fault tolerance threshold, thereby avoiding the problem of angle control failure due to a single sensor failure or signal abnormality. When the deviation is within the allowable range, the angle detection accuracy is improved by averaging and fusing the two sets of angle data, making the swing arm bending angle control more accurate and reliable.

[0048] In some embodiments of this application, it also includes: During the bending process, the extreme positions are monitored by the origin sensor and the cylinder sensor. When the angle value is greater than the bending angle and reaches the preset safety threshold, the power source is cut off.

[0049] Specifically, during the bending process, in addition to real-time detection of the swing angles of the first and second swing arms using a hollow rotary encoder and a base shaft encoder, the limit positions of the swing arms and drive mechanism are also monitored in real-time using an origin sensor located at the first slide and a cylinder sensor connected to the hydraulic drive mechanism. The origin sensor detects the swing arm's zero-return position or initial reference position. When the equipment starts or performs a reset action, the origin sensor confirms whether the swing arm is in the set initial position to ensure the accuracy of the subsequent bending angle calculation. The cylinder sensor monitors the stroke state of the hydraulic cylinders driving the first and second swing arms to rotate. By detecting the extension or retraction position of the cylinder piston rod, it determines whether the swing arm is approaching its mechanical limit position. During the bending process, the control system continuously acquires the swing arm angle value calculated by the encoder and compares this angle value with the preset bending angle. When the angle value reaches the set bending angle, the control system normally stops the power source to complete the bending of the bar. Simultaneously, the control system also sets a preset safety threshold higher than the bending angle as a second level of safety protection. When the swing arm continues to tilt inward due to control system malfunctions, sensor signal errors, or mechanical inertia, causing the detected angle value to exceed the set bending angle and approach the preset safety threshold, the safety monitoring system composed of the origin sensor and cylinder sensor will comprehensively judge the swing arm's operating status. Once the system detects that the swing arm's operating status exceeds the normal control range or reaches the preset safety threshold, the control system immediately issues a safety protection command, directly cutting off the power source driving the swing arm's tilt, such as cutting off the hydraulic system or motor drive power. At the same time, it triggers the equipment alarm module to provide a fault indication, thereby causing the equipment to stop operating immediately.

[0050] Understandably, by using origin sensors and cylinder sensors to monitor the extreme positions of the swing arm in real time during the bending process, and automatically cutting off the power source when the angle value exceeds the set bending angle and reaches the preset safety threshold, the equipment forms a multi-level safety protection mechanism. This not only prevents the swing arm from over-rotating and causing equipment damage, but also avoids the bar from deforming or becoming scrapped due to excessive bending.

[0051] In some embodiments of this application, it also includes: Record the actual angle value, target pressure value, and bending completion time for each bending process to form a historical process database; when processing the same cross-sectional bar again, call the parameters in the historical process database as the initial settings.

[0052] Specifically, during the bending process, the control system acquires angle data from the swing arm angle detection module, pressure data from the hydraulic control module, and bending time information in real time, and integrates and stores the corresponding data after each bend. The recorded data includes at least: the actual angle value of the swing arm during bending, the target pressure value corresponding to the reverse balance oil pressure, and the bending completion time for one complete bend. Simultaneously, the control system can also record the cross-sectional specifications of the currently processed bar, such as the bar cross-sectional area, bar straight length, end starting length, and bending angle, and stores this data in association, thereby constructing a historical process database with a relationship of "bar cross-sectional specifications—bending parameters—processing results." In subsequent production processes, when processing bars of the same cross-sectional specifications or model is required, the control system first reads the bar specification information input through the operation interface or obtains the current bar cross-sectional specification data through the identification module, and then matches this specification data with the records in the historical process database. When a historical record with a corresponding cross-sectional specification is detected in the database, the control system automatically retrieves the corresponding bending parameter data, such as the target pressure value, swing arm angle control parameters, and bending time parameters from the historical record, and loads them into the control system as the initial settings for the current processing task. Based on this, operators can fine-tune some parameters according to actual production needs, such as appropriately modifying the bending angle, pressure value, or delay parameters to adapt to batch differences in materials or changes in process requirements. After completing a new bending process, the equipment continues to write the actual operating data obtained from this processing into the historical process database, thereby continuously improving the database content and allowing the system to gradually accumulate richer and more accurate process parameter data.

[0053] Understandably, by establishing a historical process database in the control system and automatically recording key parameters such as the actual angle value, target pressure value, and bending completion time during each bending process, the historical process parameters can be directly called as the initial settings when processing the same cross-sectional bar again, thereby reducing manual debugging time and improving parameter setting efficiency.

[0054] Based on another preferred embodiment described above, see [link to preferred embodiment]. Figure 2 As shown, this embodiment provides a control system for a wound-rotor bar forming machine for a motor rotor, used to apply the above-described control method for a wound-rotor bar forming machine for a motor rotor, including: The setting module is configured to set the straight length of the bar, bending angle, end starting length and rotor center position parameters; and control the drive mechanism to move the first slide, second slide, third slide and fourth slide, and adjust the straight spacing, end position and clamping R block size of the clamping plates; The first adjustment module is configured to determine the pressure level and select the target pressure value according to the cross-sectional specifications corresponding to the straight length of the bar; to start the oil pump hydraulic system and apply reverse balance oil pressure to the hydraulic mechanism that drives the first and second swing arms to flip through the pressure reducing valve, and to adjust the reverse balance oil pressure to offset part of the tensile force generated during the bending process of the bar; The second adjustment module is configured to control the clamping plate to clamp the bar, and then drive the first and second swing arms to rotate relative to the base via a power source; the angle values ​​of the first and second swing arms are collected by a hollow rotary encoder and a base shaft encoder; when the angle value reaches the bending angle, the power source is controlled to stop, and the first and second top arc components cooperate to bend the bar into a motor rotor bar. The production module is configured to release the control clamp after bending, drive the first and second swing arms to move outward and remove the wire bar.

[0055] In summary, during the bending process, a counter-balancing oil pressure is applied to the hydraulic mechanism driving the first and second swing arms via a pressure reducing valve. This pressure is categorized into high, medium, and low pressure levels based on the bar cross-section specifications. This ensures that the applied thrust can counteract most of the tensile force generated during bending, requiring only a small pulling force to move the swing arms towards the center. This avoids bar bowing or thinning caused by unstable swing arm movement speed, improving the stability and yield of the bending process. The hollow rotary encoder and base shaft encoder collect real-time angle data of the first and second swing arms, and control the start and stop of the power source based on the angle values. This enables digital control of the swing arm bending angle, allowing direct setting of the bending angle on the control interface. This facilitates rapid and accurate parameter adjustment, improving equipment adjustment efficiency and bending angle accuracy. Deviation verification is performed using dual-angle data from a hollow rotary encoder and a base shaft encoder. When the detected angle data deviation exceeds a preset threshold, the power source is stopped and an alarm signal is issued in a timely manner. Simultaneously, a point sensor and limit switches serve as ultimate safety protection, forming a multi-level safety protection mechanism to prevent equipment malfunction or structural damage. Four servo motors drive the first, second, third, and fourth slides respectively, and real-time position feedback detects and corrects slide position deviations, enabling each slide to move synchronously according to a set ratio. This achieves automated adjustment of the bar's straight length, end position, and clamping spacing, improving the equipment's adaptability to different specifications of bar. The bending mechanism forms a stable force-bearing structure through the first swing arm, first fixed arm, second fixed arm, and second swing arm, concentrating the force points of each working arm at the root of the arm. This effectively withstands the torsional load, reverse jacking force, and bending force generated during bar bending, improving the overall structural stability and load-bearing capacity of the equipment. By recording the actual angle value, target pressure value, and bending completion time during each bending process and forming a historical process database, the corresponding parameters can be automatically called as initial settings when processing the same specification bar again. This reduces equipment debugging time, improves production efficiency, and gradually optimizes bending process parameters.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A control method for a wound-rotor bar forming machine for a wound-rotor motor, characterized in that, include: Set the straight length of the wire bar, bending angle, end starting length, and rotor center position parameters; and control the drive mechanism to move the first slide, second slide, third slide, and fourth slide, and adjust the straight spacing, end position, and R-block size of the clamping point of the clamping plates; Based on the cross-sectional specifications corresponding to the straight length of the bar, determine the pressure level and select the target pressure value; turn on the oil pump hydraulic system, and apply reverse balance oil pressure to the hydraulic mechanism that drives the first and second swing arms to flip through the pressure reducing valve, and adjust the reverse balance oil pressure to offset part of the tensile force generated during the bending process of the bar; After the clamping plate clamps the bar, the first and second swing arms are driven to rotate relative to the base by the power source. The angle values ​​of the first swing arm and the second swing arm are collected by the hollow rotary encoder and the base shaft encoder; when the angle value reaches the bending angle, the power source is controlled to stop, and the first top arc component and the second top arc component cooperate to bend the wire bar into the motor rotor wire bar. After bending is completed, the control clamp is released, driving the first and second swing arms to move outward and remove the wire rod.

2. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 1, characterized in that, When the control drive mechanism moves the first slide, second slide, third slide, and fourth slide, it includes: Based on the rotor center position parameters, the target displacements of the first slide, second slide, third slide, and fourth slide are determined; the four servo motors are controlled to start simultaneously according to a preset synchronization ratio, driving their respective ball screws to rotate.

3. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 2, characterized in that, When driving the respective ball screws to rotate, it includes: During rotation, the position feedback of the four slides is monitored in real time. When the position deviation between any two slides exceeds the allowable tolerance, the movement is paused and the position is corrected.

4. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 1, characterized in that, When determining the pressure level and selecting the target pressure value, the following steps are included: The pressure ratings include high pressure ratings, medium pressure ratings, and low pressure ratings. Obtain the cross-sectional area data of the current bar, and compare the cross-sectional area data with an area threshold; the area threshold includes a first area threshold and a second area threshold; the first area threshold is greater than the second area threshold; When the cross-sectional area is greater than the first area threshold, the high pressure level is selected; when the cross-sectional area is less than or equal to the first area threshold and greater than the second area threshold, the medium pressure level is selected; when the cross-sectional area is less than or equal to the second area threshold, the low pressure level is selected.

5. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 4, characterized in that, When determining the pressure level and selecting the target pressure value, the following are also included: The reference oil pressure value corresponding to the selected pressure level is used as the target pressure value, and the first and second swing arms are driven by the output of the pressure reducing valve.

6. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 1, characterized in that, Adjusting the reverse balancing oil pressure to counteract part of the tensile force generated during the bending of the wire rod includes: During the rotation of the first and second swing arms, the angle value collected by the hollow rotary encoder is obtained; based on the angle value, the change in tensile force caused by the change in eccentricity during the bending of the wire bar is determined; based on the change in tensile force, the pressure value of the reverse balancing oil pressure is adjusted.

7. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 1, characterized in that, When collecting the angle values ​​of the first and second swing arms, the following are included: The system synchronously reads the first angle data of the hollow rotary encoder and the second angle data of the base shaft encoder; determines the deviation value between the first angle data and the second angle data; when the deviation value is greater than a preset fault tolerance threshold, it determines that the angle acquisition system is abnormal, immediately controls the power source to stop and outputs a fault alarm signal; when the deviation value is less than or equal to the fault tolerance threshold, it takes the average value of the first angle data and the second angle data as the angle value.

8. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 1, characterized in that, Also includes: During the bending process, the extreme position is monitored by the origin sensor and the cylinder sensor. When the angle value is greater than the bending angle and reaches the preset safety threshold, the power source is cut off.

9. The control method for a wound-rotor bar forming machine for a wound-rotor motor according to claim 1, characterized in that, Also includes: Record the actual angle value, target pressure value, and bending completion time for each bending process to form a historical process database; When processing bar wires with the same cross-sectional specifications again, the parameters in the historical process database are used as the initial settings.

10. A control system for a wound-rotor bar forming machine for a motor rotor, used in applying the control method for a wound-rotor bar forming machine as described in any one of claims 1-9, characterized in that, include: The setting module is configured to set the straight length of the bar, bending angle, end starting length and rotor center position parameters; and control the drive mechanism to move the first slide, second slide, third slide and fourth slide, and adjust the straight spacing, end position and clamping R block size of the clamping plates; The first adjustment module is configured to determine the pressure level and select the target pressure value according to the cross-sectional specifications corresponding to the straight length of the bar; to start the oil pump hydraulic system and apply reverse balance oil pressure to the hydraulic mechanism that drives the first swing arm and the second swing arm to flip through the pressure reducing valve, and to adjust the reverse balance oil pressure to offset part of the tensile force generated during the bending process of the bar; The second adjustment module is configured to control the clamping plate to clamp the wire bar, and then drive the first and second swing arms to rotate relative to the base via a power source. The angle values ​​of the first swing arm and the second swing arm are collected by the hollow rotary encoder and the base shaft encoder; when the angle value reaches the bending angle, the power source is controlled to stop, and the first top arc component and the second top arc component cooperate to bend the wire bar into the motor rotor wire bar. The production module is configured to release the control clamp after bending, drive the first and second swing arms to move outward and remove the wire bar.

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