Self-adaptive pressure lithium battery hydraulic execution module and method of curling machine

Abstract

The invention discloses a pressure-adaptive lithium battery hydraulic execution module and method of a curling machine, and belongs to the technical field of hydraulic transmission. The module comprises a driving unit, a plunger pump unit, a valve block unit and an execution oil cylinder unit which are coaxially arranged in the axial direction. And the driving unit outputs a stepping torque, and the stepping torque is converted into pulse type quantitative output of hydraulic oil through the plunger pump unit to drive the execution oil cylinder to act. The control unit calculates the dynamic stiffness based on the feedback of the pressure detection element to identify the wire diameter of the hardware fitting, identifies the material by using the pressure second derivative feature, and retrieves a target curve according to the material. And in the compaction critical area, the module is switched to a micro-stepping mode to eliminate inertia overshoot, and precise shutdown is achieved by capturing a full-compaction inflection point of system rigidity sudden change. Through mechanical-electrical-hydraulic deep cooperation, the problem of overpressure or underpressure caused by blind pressure of a traditional hydraulic tool is solved, and the crimping precision and quality consistency are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission technology, and in particular to a lithium-ion battery hydraulic actuator and method for adaptive pressure in a winding machine. Background Technology

[0002] In the construction of overhead power distribution lines and substations, PG series connectors, such as PG parallel groove clamps and H-type clamps, are key hardware for conductor connections. Current operations mostly employ traditional manual or electric hydraulic tools for crimping, placing high demands on the operational stability of workers at heights or in confined spaces.

[0003] Traditional manual hydraulic crimping tools require dozens of repetitive presses of the handle to complete a single crimp, which can easily lead to muscle fatigue and affect operational consistency when working at heights or in confined positions. Existing hydraulic tools typically rely on mechanical relief valves to set the maximum output pressure, lacking the ability to sense the actual compaction status of the terminals during the crimping process in real time. Insufficient crimping can lead to increased contact resistance due to residual micro-air gaps at the contact interface, posing a risk of overheating during operation. To ensure crimping reliability, operators often apply pressure exceeding the required level, which can damage or break the internal core of the aluminum conductor, weakening the mechanical properties of the joint. Furthermore, pneumatic or conventional electro-hydraulic devices often use continuous pressurization during the metal plastic deformation stage, and the crimping endpoint control relies on preset stroke or pressure thresholds, limiting their adaptability to different wire diameters and material combinations, and making it difficult to meet the high standards of compression ratio control required by power fittings.

[0004] Therefore, it is necessary to provide a lithium-ion battery hydraulic actuator module and method for adaptive pressure of a winding machine to solve the above problems. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and provides a lithium-ion battery hydraulic actuator module and method for adaptive pressure in a winding machine.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a lithium-ion battery hydraulic actuator module for adaptive pressure of a winding machine, comprising:

[0007] The drive unit is used to output torque with discrete step characteristics according to pulse commands;

[0008] The plunger pump unit, with its power input end connected to the drive unit, is used to convert the rotary stepping torque into a pulsed, metered output of hydraulic fluid.

[0009] The valve block unit contains interconnected high-pressure flow channels, pressure detection elements, and unloading elements.

[0010] An actuating cylinder unit, coaxially connected to the valve block unit, is used to receive pulsed hydraulic energy and drive the mold to perform a rolling action; and

[0011] The control unit is electrically connected to the drive unit and the pressure detection element, respectively, and is used to adjust the output state of the drive unit in real time based on the pressure feedback characteristics.

[0012] In a preferred embodiment of the present invention, the drive unit, the plunger pump unit, the valve block unit, and the actuator cylinder unit are arranged coaxially in sequence in the axial direction;

[0013] The drive unit includes a servo motor and an absolute encoder located at the rear end of the rotor shaft of the servo motor. The absolute encoder feeds back the instantaneous angular position of the rotor to the control unit. The front end of the rotor shaft is rigidly connected to the plunger pump unit via a multi-tooth spline coupler.

[0014] In a preferred embodiment of the present invention, the plunger pump unit includes a pump body base and a camshaft disposed at the axial center of the pump body base. The pump body base has a plurality of radial plunger holes evenly distributed along the circumference, and a plunger is installed in each of the radial plunger holes.

[0015] The camshaft has multiple eccentric surfaces, and the top of the plunger contacts the eccentric surface. When the drive unit drives the camshaft to rotate, the eccentric surface drives multiple plungers to perform oil suction and oil discharge actions in sequence, converting the rotational motion into the radial reciprocating linear motion of the plunger.

[0016] In a preferred embodiment of the present invention, the valve block unit is located between the plunger pump unit and the actuator cylinder unit;

[0017] The pressure detection element is a miniature ultra-high pressure sensor embedded in the radial mounting hole of the valve block unit. The sensing diaphragm of the miniature ultra-high pressure sensor is in direct contact with the high-pressure flow channel. The unloading element is a normally closed electromagnetic quick-opening pressure relief valve, which is used to connect the high-pressure flow channel and the low-pressure return oil chamber when the pressing is completed or when there is abnormal overpressure.

[0018] In a preferred embodiment of the present invention, the actuating cylinder unit is a single-acting booster cylinder structure, including a cylinder body, a piston rod disposed within the cylinder body, and a return spring disposed between the piston rod and the cylinder body base.

[0019] An adaptive pressure control method includes the following steps:

[0020] S10. Start the lithium battery hydraulic actuator module. In the initial pressurization range, acquire the pressure signal collected by the pressure detection element and the displacement signal calculated based on the number of pulses fed back by the drive unit in real time. Calculate the dynamic stiffness coefficient through differential operation to identify the wire diameter specification of the current crimping hardware.

[0021] S20. While identifying the wire diameter specification, perform second derivative calculation on the pressure rise slope, monitor the change law of the second derivative and determine the material properties of the current crimping fitting.

[0022] S30. Based on the identified wire diameter and material properties, retrieve the corresponding crimping target curve;

[0023] S40. When the pressure enters the compaction critical zone, the drive unit is switched from continuous operation mode to micro-stepping mode to approach the target depth.

[0024] S50. Capture the full compaction inflection point on the target pressing curve as a stop threshold. When the full compaction inflection point is detected, perform electric braking to stop.

[0025] In a preferred embodiment of the present invention, the method for calculating the dynamic stiffness coefficient in step S10 is as follows:

[0026] Discrete pressure and displacement data points are collected, and the ratio of the pressure difference to the displacement difference between the current sampling point and the previous sampling point is calculated to obtain the dynamic stiffness coefficient. The control unit performs a weighted comparison between the calculated dynamic stiffness coefficient sequence and a pre-stored wire diameter feature database to lock the wire diameter specification.

[0027] In a preferred embodiment of the present invention, in step S20, the method for determining the material properties of the current crimping fitting is as follows:

[0028] Calculate the second derivative of pressure with respect to displacement, i.e. the rate of change of stiffness, extract the peak position and slope inflection point characteristics of the second derivative, and combine the material rheology model to determine whether the current joint is made of copper, aluminum or copper-aluminum transition material.

[0029] In a preferred embodiment of the present invention, in step S40, the compaction critical zone is defined as the region of 85%-90% of the target pressure value;

[0030] The micro-stepping mode is such that the servo motor drives the plunger to discharge a fixed volume of hydraulic oil every time it rotates by a preset small angle, so that the single-step displacement of the piston rod is ≤0.02mm.

[0031] In a preferred embodiment of the present invention, the method for identifying the inflection point of full compaction in step S50 is as follows:

[0032] By monitoring the second derivative of pressure over time at high frequency, i.e. the change in pressure acceleration, when the monitored change in pressure acceleration exceeds the preset acceleration sensitivity threshold for a specific specification, it is determined to be the full compaction inflection point; at this time, it is determined that the system's overall stiffness has changed abruptly due to the complete disappearance of the air gap between the crimping hardware and the internal core wire.

[0033] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0034] (1) This invention provides a lithium-ion hydraulic actuator module for adaptive pressure of a coiler. It adopts a closed-loop control architecture with a pump-cylinder coaxial structure and centrifugal stepping power. It uses a servo motor in conjunction with a plunger pump to convert continuous fluid flow into pulsed quantitative output and realizes digital perception of the crimping state based on the dynamic stiffness characteristics calculated in real time. This deep integration of electromechanical and hydraulic systems enables the actuator module to adaptively match different work objects, effectively solving the control blind zone problem caused by the blind pressure caused by the reliance on mechanical relief valves in traditional hydraulic tools. Through hardware and software collaboration, this invention fundamentally eliminates the hidden dangers caused by hydraulic inertia overshoot and lack of material identification, and significantly improves the quality consistency and operational safety of electric fitting crimping.

[0035] (2) This invention introduces a micro-stepping drive mode at the end of the crimping process. When the system pressure enters the critical compaction zone, the control unit drives the servo motor to step at a very small preset angle, cooperating with the cam mechanism to drive the plunger to discharge a fixed volume of oil, so that the piston rod approaches the target depth with a single-step displacement at the micrometer level. This discrete micro-injection method provides a time window for the algorithm to extract physical features in the micro-pressure gap, eliminating the inertial lag effect in fluid dynamics. Compared with the continuous pressure boosting method often used in pneumatic or conventional electro-hydraulic devices in the metal plastic deformation stage in the prior art, this invention effectively avoids overpressure cracks caused by the delay in shutdown response, ensures the accuracy of crimping depth control, and greatly improves the mechanical properties and durability of the joint.

[0036] (3) This invention proposes an adaptive identification method based on dynamic stiffness and second derivative characteristics. In the initial stage of crimping, the dynamic stiffness coefficient is calculated by monitoring the rate of change of pressure with displacement to lock the wire diameter specification. In the plastic deformation stage, the differences in work hardening of different materials such as copper and aluminum are identified by analyzing the abrupt change in the second derivative of the pressure rise slope. This method allows the tool to automatically retrieve a specific crimping target curve based on the actual physical properties of the crimped part, rather than simply executing a single pressure threshold. Compared to traditional tools with limited adaptability to different wire diameter and material combinations, often requiring manual judgment based on experience or frequent setting changes, this invention fundamentally eliminates the hidden dangers of strand breakage due to overpressure on small-diameter wires or residual air gaps due to underpressure on large-diameter wires caused by missing material characteristic identification.

[0037] (4) This invention uses the full compaction inflection point based on the sudden change in the overall stiffness of the system as the shutdown criterion, and uses the sensitive threshold of pressure acceleration change to capture the instantaneous physical state when the air gap between the conductors completely disappears and the fittings fuse into a solid. This judgment method changes the evaluation standard of crimping quality from the indirect force value to the direct deformation in place, and can keenly perceive the subtle differences caused by mold wear, fitting dimensional tolerances or changes in hydraulic oil viscosity. Compared with the existing technology that simply relies on pressure sensor values ​​or mechanical pressure relief valves for open-loop control, this method ensures that the minimum contact resistance can be obtained under various working conditions, and the recorded digital crimping characteristic curve provides reliable data support for the full life cycle traceability of construction quality. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is an overall axial sectional view of a lithium-ion battery hydraulic actuator module according to a preferred embodiment of the present invention;

[0040] Figure 2 This is a block diagram of the electromechanical-hydraulic control system of a preferred embodiment of the present invention;

[0041] Figure 3 This is a flowchart of the adaptive pressure control method according to a preferred embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the pressure-displacement characteristic curve and second derivative characteristics during the crimping process of a preferred embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of pressure approximation in the micro-stepping mode of a preferred embodiment of the present invention.

[0044] In the diagram: 1. Servo motor; 2. Multi-tooth spline coupler; 3. Piston pump unit; 4. Valve block unit; 5. Pressure detection element; 6. Unloading element; 7. Cylinder body; 8. Piston rod; 9. Return spring. Detailed Implementation

[0045] In the field of electric coiling operations, traditional hydraulic actuators have long relied on a passive control logic based on continuous oil supply feedback and pressure threshold shutdown. This principle has limitations: firstly, the flow inertia of the hydraulic system at the forming end and the motion lag of the actuator make it difficult for the pressure head to achieve micron-level braking accuracy under high loads of up to 12T, often resulting in significant physical overshoot; secondly, open-loop control based on static pressure thresholds ignores the dynamic resistance differences between different materials (copper, aluminum) and wire diameters during plastic deformation, failing to fundamentally eliminate safety hazards such as overpressure damage or underpressure residual air gaps caused by missing material characteristic identification.

[0046] This invention introduces a digital stepping piston pump and utilizes an eccentric cam mechanism to transform continuous fluid flow into pulsed discrete injection, providing a time window for the algorithm to extract physical features in the microscopic pressurization gap. The control unit then calculates the dynamic stiffness coefficient and pressure characteristics in real time, enabling online identification of wire diameter and material. Subsequently, expert curves are retrieved, and the second derivative mutation is used to capture the full compaction inflection point, driving the pressure head to approach the endpoint with micron-level precision and stop promptly. This achieves a logical closed loop from data perception to precise execution, significantly improving pressing consistency and operational efficiency.

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0049] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this application.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] like Figure 1 and Figure 2 As shown, this embodiment provides a lithium-ion battery-powered hydraulic actuator module for adaptive pressure in a winding machine. The lithium-ion battery-powered hydraulic actuator module includes:

[0052] The drive unit is used to output torque with discrete step characteristics according to pulse commands;

[0053] The plunger pump unit 3 has its power input end connected to the drive unit and is used to convert the rotary stepping torque into a pulsed quantitative output of hydraulic oil.

[0054] The valve block unit 4 has interconnected high-pressure flow channels, pressure detection elements 5 and unloading elements 6 inside;

[0055] The hydraulic cylinder unit is coaxially connected to the valve block unit 4 and is used to receive pulsed hydraulic energy and drive the mold to perform a rolling action.

[0056] The control unit is electrically connected to the drive unit and the pressure sensing element 5, respectively, and is used to adjust the output state of the drive unit in real time based on the pressure feedback characteristics.

[0057] Furthermore, the lithium-ion battery hydraulic actuator module adopts a highly integrated coaxial pump-cylinder design in its overall architecture. The core purpose is to significantly improve power density by eliminating the bulky external piping and split structures found in traditional hydraulic tools. The overall outline of the lithium-ion battery hydraulic actuator module presents a multi-tiered, stepped cylindrical shape. From the power input end to the actuation output end, the drive unit, piston pump unit 3, valve block unit 4, and actuation cylinder unit are arranged coaxially in sequence along the axis. This linear arrangement ensures efficient power transmission and minimalist hydraulic flow channels.

[0058] The core innovation of this invention lies in its deep coupling of discrete stepping power with real-time pressure characteristic sensing, constructing a digital transmission chain from electrical energy to mechanical energy and then to hydraulic energy. The basic principle utilizes the micro-stepping characteristics of the drive unit, combined with the quantitative oil discharge of the piston pump, ensuring that each displacement of the actuator cylinder is in a quantifiable and controllable micro-step state. This approach completely solves the technical problems of blind spots in crimping pressure control and insufficient forming accuracy caused by response lag and inertial overshoot in traditional hydraulic systems, achieving controlled pressure output of over 12T within a miniaturized space.

[0059] The following section, in conjunction with the accompanying drawings, provides a comprehensive and detailed explanation of the specific structure, connection relationships, manufacturing processes, and dynamic processes of the system's collaborative operation for each of the aforementioned components.

[0060] To achieve the aforementioned precision crimping function, this invention is built on a highly integrated electromechanical-hydraulic hardware platform. The platform was designed to overcome the conflicting demands of power construction, cable processing, and other fields for hand tools that are small in size, powerful, and highly precise.

[0061] Specifically, at the hardware implementation level, the lithium-ion battery hydraulic actuator module has an axially coaxial configuration. Precise angular displacement is provided by the drive unit and transmitted to the piston pump unit 3 via a multi-tooth spline coupler 2. This piston pump unit 3 discretizes the angular displacement into volumetric displacement through the reciprocating action of the cam and piston, with each pumped hydraulic oil (oil reservoir) corresponding to a specific pulse command. This discretized hydraulic power flows through the valve block unit 4, which integrates a high-frequency pressure detection element 5, providing real-time feedback on system stiffness. The actuator cylinder unit, acting as the end effector, converts hydraulic energy into linear thrust while overcoming the return spring 9's force.

[0062] Against this backdrop, the core technical approach of this invention lies in adaptive adjustment based on pressure feedback characteristics. This adaptive adjustment method surpasses the traditional single pressure threshold shutdown logic. The implementation principle is as follows: at the beginning of the pressing stage, the wire diameter of the pressed part is automatically identified by monitoring the rate of change of pressure with the step displacement, i.e., dynamic stiffness; in the middle stage of pressing, the rheological characteristics of the material, such as the yield point difference between copper and aluminum, are identified using the second derivative of pressure change; at the end of the pressing stage, the fully compacted state is determined by capturing the pressure step inflection point, and an electric brake is immediately implemented.

[0063] This adaptive adjustment method transforms the lithium-ion hydraulic actuator module, originally an open-loop actuator, into an intelligent robotic end effector with self-sensing capabilities. It not only achieves a high degree of physical integration but also generates a synergistic effect beyond the function of a single component through the collaboration of software algorithms and hardware characteristics. This allows it to automatically adapt to the optimal crimping curve for different working conditions, significantly improving the consistency of crimping quality and the system's energy efficiency.

[0064] To enable those skilled in the art to implement this technical solution, the following detailed disassembly of each unit of the lithium battery hydraulic actuator module is provided at the component level.

[0065] The drive unit is located at the very end of the lithium-ion battery hydraulic actuator module. This drive unit includes a miniature high-power-density brushless servo motor 1 and an absolute encoder located at the rear end of the rotor shaft of the servo motor 1. The front end of the rotor shaft of the servo motor 1 is rigidly connected to the camshaft in the plunger pump unit 3 via a set of multi-tooth spline couplers 2 with a tooth profile accuracy of level 6.

[0066] Furthermore, the absolute encoder located at the rear end of the rotor shaft has a resolution of no less than 17 bits, which can feed back the instantaneous angular position of the motor rotor to the control unit in real time. The sampling frequency is 5-20kHz, which provides high-precision data support for the subsequent calculation of the micro-displacement of the hydraulic cylinder unit through pulse counting.

[0067] The plunger pump unit 3, as the core component for hydraulic energy conversion, is responsible for converting the rotational motion of the servo motor 1 into discrete flow output of hydraulic oil. The plunger pump unit 3 includes: a pump body base, and multiple radial plunger holes evenly distributed circumferentially within the pump body base. Preferably, there are three plunger holes, each containing a plunger and a plunger sleeve with a clearance of <5μm to ensure minimal internal leakage under ultra-high pressure.

[0068] Furthermore, a camshaft is located at the center of the pump body, and the camshaft is coupled to the rotor shaft of the drive unit through an internal spline hole. The camshaft is designed with multiple eccentric surfaces, and the top of the plunger contacts the eccentric surface of the camshaft through cylindrical rollers, converting the rotational motion into the radial reciprocating linear motion of the plunger.

[0069] When the drive unit rotates the camshaft, the eccentric surface drives three plungers to sequentially perform oil suction and discharge actions. Each plunger has a small return spring at its bottom to ensure that the plunger always remains in contact with the corresponding eccentric surface of the camshaft. This three-plunger array layout effectively counteracts radial forces, reduces bearing load, and significantly reduces the pulsation of the output hydraulic force.

[0070] Valve block unit 4, located between plunger pump unit 3 and actuator cylinder unit, serves not only as a transfer station in the flow path but also integrates monitoring and protection components. The high-pressure flow channel inside valve block unit 4 is formed using EDM or drilling processes. A pressure detection element 5, a miniature ultra-high pressure sensor, is embedded in the radial mounting hole of valve block unit 4. The sensor's diaphragm directly contacts the high-pressure flow channel, enabling real-time, zero-delay pressure acquisition. Furthermore, valve block unit 4 also includes an unloading element 6, a normally closed electromagnetic quick-opening pressure relief valve with a silicon nitride ceramic valve core, possessing extremely high hardness and erosion resistance. When crimping is completed or the system detects abnormal overpressure, the control unit drives the electromagnet to rapidly connect the high-pressure chamber and the low-pressure return oil chamber, achieving millisecond-level pressure relief.

[0071] The hydraulic cylinder unit is located at the front end of the lithium-ion battery hydraulic actuator module and is responsible for the final pressure output. The hydraulic cylinder unit adopts a single-acting booster cylinder structure, including: cylinder body 7, return spring 9, and piston rod 8. The front end of the piston rod 8 extends out of the lithium-ion battery hydraulic actuator module housing and is equipped with a standard T-type interface for quickly mounting fittings crimping dies of different specifications.

[0072] Furthermore, in order to achieve efficient sealing within a compact space, the rear end of the piston rod 8 is equipped with a three-stage sealing structure, including a dustproof ring, a PTFE support ring, and a special high-pressure main sealing ring made of nitrile rubber and fluororubber composite, which reduces starting friction while ensuring zero leakage.

[0073] Additionally, a return spring 9 is positioned between the piston rod 8 and the base of the cylinder body 7. When high-pressure oil enters the rear chamber of the cylinder body 7, pushing the piston rod 8 to overcome the elastic force of the return spring 9 and perform linear motion, the lithium-ion hydraulic actuator module can smoothly output a rated pressure of up to 12T based on the product of the high pressure generated by the plunger pump unit 3 and the piston cross-sectional area. When the system is unloaded, the preload force of the return spring 9 pushes the piston rod 8 back to its initial position and pressurizes the hydraulic oil back to the tank.

[0074] like Figure 3 As shown, this invention not only achieves a high degree of integration of the pump and cylinder coaxiality in terms of hardware structure, but its core innovation lies in providing an adaptive pressure control method based on the aforementioned lithium-ion hydraulic actuator module. This method achieves intelligent and precise identification and adaptive control of fittings of different specifications and materials by digitally monitoring the mechanical response characteristics throughout the pressing process.

[0075] Specifically, the control method includes the following steps:

[0076] Step S10: The lithium-ion hydraulic actuator module is started. In the initial pressure boosting range after the front mold contacts the hardware terminal, the pressure signal P collected by the pressure detection element 5 and the piston displacement signal s calculated based on the number of pulses fed back by the drive unit are acquired in real time. The dynamic stiffness coefficient K is calculated to identify the wire diameter specification of the current crimping hardware.

[0077] Step S20: While identifying the wire diameter specification, perform second derivative calculation on the pressure rise slope, monitor the change law of the second derivative, and determine the material properties of the current crimping fitting.

[0078] Step S30: Retrieve the crimping target curve corresponding to the current crimping fitting wire diameter and material combination.

[0079] Step S40: When the pressure enters the compaction critical zone, the drive unit is switched from continuous operation mode to micro-stepping mode, and approaches the target depth with a single-step displacement of ≤0.02mm.

[0080] Step S50: Capture the full compaction inflection point on the crimping target curve as the stop threshold. The full compaction inflection point is defined as the instantaneous point at which the overall stiffness of the system changes abruptly due to the complete disappearance of the air gap between the crimping fitting and the internal core wire. Once the full compaction inflection point is identified, perform electric braking to stop.

[0081] The above control method solves the problem of blind pressing in traditional hydraulic tools through deep collaboration between hardware and software. Its core lies in transforming the pressing process from simply stopping once the specified force value is reached to real-time analysis of the material's deformation state. The implementation methods for each step are explained in detail below:

[0082] In step S10, the pressure range of 0.5T to 2T within the initial pressurization range is selected as the detection range. When the control unit senses that the pressure begins to rise and is within the detection range of 0.5T to 2T, the sampling module of the control unit begins to capture the pressure signal P from the pressure detection element 5 and the piston displacement signal s calculated based on the absolute encoder pulse count in the drive unit. The dynamic stiffness coefficient K is calculated by performing real-time differential calculations on the collected discrete data points. ,in, and These are the pressure and displacement values ​​at the current sampling point, respectively.

[0083] At this stage, terminals with different wire diameters will exhibit completely different mechanical feedbacks due to differences in cross-sectional area and internal porosity, as shown in the typical characteristic curves. Figure 4 As shown. Specifically:

[0084] Large wire diameter terminals, such as 240mm 2During the initial pressing process, the crimped terminal has a relatively large metal deformation space and relatively dispersed structural stiffness, resulting in a low slope of the Ps curve and a relatively gentle increase in the K value.

[0085] Small wire diameter terminals, such as 35mm 2 The crimped terminals exhibit an extremely high K-value growth rate due to the rapid compaction of the material.

[0086] Furthermore, the control unit performs a weighted comparison between the calculated dynamic stiffness coefficient K value sequence and the pre-stored wire diameter feature database, thereby locking the wire diameter specification in the early stage of crimping.

[0087] In step S20, while identifying the wire diameter specification, the control unit further analyzes the second-order characteristics of the pressure curve, that is, calculates the second derivative of pressure with respect to displacement. The key to this step is identifying the hardware material, specifically the differences in hardening characteristics of crimp terminals made of copper, aluminum, or copper-aluminum transition materials during the plastic deformation stage. Specifically:

[0088] After entering the yielding stage, the work hardening phenomenon caused by the lattice distortion of copper terminals is more significant than that of aluminum terminals. The second derivative of the pressure change with displacement, i.e. the rate of change of stiffness, is significantly higher for copper terminals than for aluminum terminals. Aluminum is softer, and the pressure rises more linearly after yielding.

[0089] Furthermore, by extracting the peak position and slope inflection point characteristics of the second derivative, and combining them with the material rheology model, the current joint can be accurately determined to be made of copper, aluminum, or a copper-aluminum transition material, thereby correcting the subsequent target pressure value.

[0090] In step S30, after steps S10 and S20, the wire diameter specification and material combination of the current crimping fitting are determined, and a specific crimping target curve is retrieved from the database. This crimping target curve includes: the final pressure value, and the ideal pressure path (Ps curve) and displacement endpoint range of the fitting of this specific specification when achieving atomic-level tight contact, providing a dynamic benchmark for subsequent precision control.

[0091] In step S40, when the system pressure approaches the preset compaction critical zone of the target curve, the drive unit automatically switches from the traditional continuous rotation mode to the micro-stepping drive mode, and the approach process is as follows: Figure 5 As shown.

[0092] The critical compaction zone is defined as the area of ​​85% to 90% of the target pressure value.

[0093] During this stage, servo motor 1 uses high-resolution encoder feedback to drive plunger pump unit 3 for pulse-type oil discharge. Servo motor 1 rotates by a preset minute angle... The camshaft drives the plungers to discharge a fixed volume of hydraulic oil. This is determined by the number of plungers (n), the plunger radius (r), and the plunger lift, which varies with the step angle of the servo motor (1). The volume of a single oil packet is fixed: At this point, the motion of piston rod 8 changes from continuous sliding to micrometer-level discrete stepping, with a single-step displacement ≤ 0.02 mm.

[0094] Approaching the end of the crimping process effectively eliminates the risk of pressure overshoot caused by fluid inertia.

[0095] In step S50, this step no longer relies solely on a fixed pressure peak value as the shutdown criterion, because simple pressure control is easily affected by factors such as mold wear and changes in hydraulic oil viscosity. This invention employs a full-compaction inflection point identification algorithm based on a sudden change in the overall system stiffness. When the air gap between each core wire in the conductor is completely eliminated, and the fittings and conductors fuse into a nearly seamless metallic entity, the mechanical stiffness of the system experiences a step-like increase, and the contact resistance reaches its minimum value.

[0096] By capturing this instantaneous change in pressure acceleration at high frequency, the judgment condition is set as follows: ,in An acceleration sensitivity threshold is preset for specific specifications. Once this condition is triggered, the control unit immediately activates the braking function of servo motor 1 to lock the current piston position, thereby ensuring that the deviation of the final molding size is strictly controlled within the requirements, and guaranteeing that the crimping quality of each joint meets the electrical connection requirements.

[0097] To further verify the superiority of the module and method described in this invention, a specific experimental embodiment is provided below, and a comparative analysis is conducted with traditional hydraulic crimping tools.

[0098] In one specific embodiment, a copper terminal block of specification DT-240 is selected as the crimping object. The standard crimping displacement design value of this terminal is 12.45mm, and the ideal target pressure is 10.8T. During the operation of the lithium-ion battery hydraulic actuator module of this invention, when the system identifies 240mm in step S10... 2 After determining the characteristic stiffness, a copper pressing strategy was automatically applied. When pressing to a displacement of 12.10 mm, the system detected a non-linear abrupt change in the pressure rise slope. Entering the stepping mode in step S30, it approximated at a frequency of 0.008 mm / step. At the 12.42 mm position, the system determined the appropriate value using a formula. If the preset threshold is exceeded, the motor will lock instantly and depressurize. After disassembly and measurement, the final molding depth is 12.43mm, which fully complies with engineering specifications.

[0099] As a control, the EZ-300 constant-pressure lithium-ion hydraulic clamp, a mainstream tool on the market, was used for the same experiment. This tool was only set with a mechanical pressure relief threshold of 11T. Due to hydraulic inertia and a lack of perception of material properties, after the pressure reached the pressure relief point, the piston actually continued to advance a certain distance due to the delay in the opening of the relief valve and the inertia of the pump unit stopping. This resulted in a final forming depth of 12.65mm. Observation revealed obvious overpressure cracks on the surface of the fitting, and the internal core wire suffered local shear damage.

[0100] Table 1 below provides a detailed comparison of the data performance of the embodiments of the present invention and the conventional comparative examples on several key technical indicators.

[0101] Table 1. Performance Evaluation Comparison

[0102]

[0103] A comparison of the data in Table 1 above clearly shows that the adaptive pressure lithium-ion hydraulic actuator module for a rewinding machine described in this invention, with its ingenious coaxial pump and cylinder physical structure and closed-loop control algorithm based on stiffness feedback, has achieved a leapfrog improvement over existing technologies in multiple dimensions such as pressing accuracy, electrical performance, energy efficiency, and operational safety.

[0104] In terms of specific engineering implementation details, when the servo motor 1 in the drive unit is working, the control cycle of its internal driver is set to 50μs. After receiving the analog signal from the pressure sensor, it is digitized by a 16-bit ADC converter and then processed by a second-order Butterworth low-pass filter to remove high-frequency interference signals generated by hydraulic pulsation. In the material identification process of step S20, the control unit not only analyzes the second derivative but also performs cross-validation based on the current motor current value. Due to the high hardness of copper, the motor requires a larger electromagnetic torque for the same displacement increment. The product of the integral value of the current feedback signal and the pressure rise slope constitutes a multi-dimensional judgment space, which greatly improves the robustness of material identification.

[0105] In terms of the durability design of the mechanical structure, the piston rod 8 sealing system of the actuator cylinder unit adopts a three-stage sealing architecture. The first stage is a dustproof ring made of nitrile rubber, used to scrape away dust and metal debris that may be brought in from the working environment; the second stage is a PTFE support ring filled with glass fiber, used to bear the radial load during the movement of the piston rod 8; the third stage is a high-pressure main sealing ring, whose mating surfaces are ultra-precision ground to ensure static pressure holding at 70MPa for 5 minutes with a pressure drop ≤0.5MPa. This multi-stage sealing design extends the module's maintenance cycle compared to traditional solutions.

[0106] Furthermore, the digital characteristics of the lithium-ion battery hydraulic actuator in this invention lay the foundation for full lifecycle management of construction quality. The integrated storage chip within the control unit can record the characteristic curves of the most recent 5000 pressing operations. Each curve contains detailed data on pressure, displacement, current, time, and other dimensions. Through the reserved Bluetooth or infrared interface of the lithium-ion battery hydraulic actuator, construction data can be synchronized to mobile terminals in real time and uploaded to a cloud management platform. This establishment of a digital quality fingerprint allows regulatory authorities to accurately trace the pressing status of each joint. If the Ps curve of a pressing operation deviates from the standard model by more than 15%, the system will automatically issue a warning, effectively avoiding potential risks caused by human error or mold aging.

[0107] In a further preferred embodiment, the pump body base of the plunger pump unit 3 can also be made of titanium alloy to further reduce the overall weight of the module. Simultaneously, the excellent elastic modulus of titanium alloy absorbs some pressure pulsations, further improving the sampling signal-to-noise ratio of the pressure sensor. The return spring 9 of the actuator cylinder unit can adopt a variable stiffness spring design, providing greater elastic force during the initial return phase to accelerate oil return, and providing less elastic force near the pressing start point to reduce the motor load.

[0108] In summary, the adaptive pressure lithium-ion battery hydraulic actuator module and method for a winding machine of the present invention is not a simple mechanical combination, but a deeply integrated electromechanical-hydraulic control system. Through discretization improvements to the physical structure, combined with a profound understanding of the mechanical processes of metal plastic deformation, it achieves intelligent precision force output of up to 12T within a miniaturized space. This module has broad application prospects in fields such as power engineering, aerospace precision assembly, and rail transit connections.

[0109] Finally, it should be noted that the above embodiments are merely illustrative of the technical concept and features of the present invention, intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention. In practical applications, the dimensions of each component level of the module, the motor power specifications, the hydraulic oil type, etc., can all be scaled and optimized according to specific pressing tonnage requirements (such as expanding from 12T to 20T or reducing to 5T), and these variations all fall within the scope of the claims of the present invention.

Claims

1. A self-adapting pressure lithium electro-hydraulic execution module of a curling machine, characterized in that, include: The drive unit is used to output torque with discrete step characteristics according to pulse commands; The plunger pump unit, with its power input end connected to the drive unit, is used to convert the rotary stepping torque into a pulsed, metered output of hydraulic fluid. The valve block unit contains interconnected high-pressure flow channels, pressure detection elements, and unloading elements. The hydraulic cylinder unit is coaxially connected to the valve block unit and is used to receive pulsed hydraulic energy and drive the mold to perform a rolling action. as well as The control unit is electrically connected to the drive unit and the pressure detection element, respectively, and is used to adjust the output state of the drive unit in real time based on the pressure feedback characteristics.

2. The adaptive pressure lithium electro-hydraulic execution module of a curling machine according to claim 1, wherein, The drive unit, the plunger pump unit, the valve block unit, and the actuator cylinder unit are arranged coaxially in sequence along the axial direction. The drive unit includes a servo motor and an absolute encoder located at the rear end of the rotor shaft of the servo motor. The absolute encoder feeds back the instantaneous angular position of the rotor to the control unit. The front end of the rotor shaft is rigidly connected to the plunger pump unit via a multi-tooth spline coupler.

3. The adaptive pressure lithium electro-hydraulic execution module of a curling machine according to claim 2, wherein, The plunger pump unit includes a pump body base and a camshaft located at the axial center of the pump body base. The pump body base has a plurality of radial plunger holes evenly distributed along the circumference, and a plunger is installed in each of the radial plunger holes. The camshaft has multiple eccentric surfaces, and the top of the plunger contacts the eccentric surface. When the drive unit drives the camshaft to rotate, the eccentric surface drives multiple plungers to perform oil suction and oil discharge actions in sequence, converting the rotational motion into the radial reciprocating linear motion of the plunger.

4. The adaptive pressure lithium electro-hydraulic execution module of a curling machine according to claim 1, wherein, The valve block unit is located between the plunger pump unit and the actuator cylinder unit; The pressure detection element is a miniature ultra-high pressure sensor embedded in the radial mounting hole of the valve block unit. The sensing diaphragm of the miniature ultra-high pressure sensor is in direct contact with the high-pressure flow channel. The unloading element is a normally closed electromagnetic quick-opening pressure relief valve, which is used to connect the high-pressure flow channel and the low-pressure return oil chamber when the pressing is completed or when there is abnormal overpressure.

5. The adaptive pressure lithium electro-hydraulic execution module of a curling machine according to claim 1, wherein, The actuator cylinder unit is a single-acting booster cylinder structure, including a cylinder body, a piston rod disposed inside the cylinder body, and a return spring disposed between the piston rod and the cylinder body base.

6. An adaptive pressure control method based on the lithium electro-hydraulic execution module of claim 1, characterized by, Includes the following steps: S10. Start the lithium battery hydraulic actuator module. In the initial pressurization range, acquire the pressure signal collected by the pressure detection element and the displacement signal calculated based on the number of pulses fed back by the drive unit in real time. Calculate the dynamic stiffness coefficient through differential operation to identify the wire diameter specification of the current crimping hardware. S20. While identifying the wire diameter specification, perform second derivative calculation on the pressure rise slope, monitor the change law of the second derivative and determine the material properties of the current crimping fitting. S30. Based on the identified wire diameter and material properties, retrieve the corresponding crimping target curve; S40. When the pressure enters the compaction critical zone, the drive unit is switched from continuous operation mode to micro-stepping mode to approach the target depth. S50. Capture the full compaction inflection point on the target pressing curve as a stop threshold. When the full compaction inflection point is detected, perform electric braking to stop.

7. A method of adaptive pressure control according to claim 6, wherein, The step S10, the calculation method of the dynamic stiffness coefficient is: Collecting discrete pressure value data points and displacement value data points, calculating the ratio of the pressure difference value and the displacement difference value between the current sampling point and the last sampling point, obtaining the dynamic stiffness coefficient; the control unit compares the calculated dynamic stiffness coefficient sequence with the pre-stored wire diameter characteristic database to lock the wire diameter specification.

8. The adaptive pressure control method of claim 6, wherein, The step S20, the method for determining the material property of the current crimping fitting is: Calculating the second derivative of pressure to displacement, that is, the stiffness change rate, extracting the peak position and slope inflection point characteristics of the second derivative, and combining the rheological model to determine whether the current joint is copper, aluminum or copper-aluminum transition material.

9. The adaptive pressure control method of claim 6, wherein, The step S40, the compaction critical region is defined as the 85%-90% region of the target pressure value; The micro-step stepping mode is that the servo motor drives the plunger to discharge a fixed volume of hydraulic oil every time it rotates a predetermined small angle, so that the single-step displacement of the piston rod is ≤0.02mm.

10. The method of claim 6, wherein, The step S50, the identification method of the full compaction inflection point is: Through high-frequency monitoring of the second derivative of pressure change with time, that is, pressure acceleration change, when the monitored pressure acceleration change exceeds the acceleration sensitive threshold preset for a specific specification, it is determined that the full compaction inflection point is reached; at this time, it is determined that the system comprehensive stiffness has suddenly changed due to the complete disappearance of the air gap between the crimping fitting and the internal core wire.

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