CN115121689B

CN115121689B - Digital twin driven fuel cell polar plate thermal vibration fluid energy-changing forming process

Info

Publication number: CN115121689B
Application number: CN202211041016.8A
Authority: CN
Inventors: 王耀; 叶晓凯; 胡宁; 魏强; 杨超
Original assignee: Hebei University of Technology
Current assignee: Hebei University of Technology
Priority date: 2022-08-29
Filing date: 2022-08-29
Publication date: 2022-12-09
Anticipated expiration: 2042-08-29
Also published as: CN115121689A

Abstract

The invention relates to the field of plastic forming, in particular to a thermal vibration fluid energy-conversion forming process of a fuel cell polar plate driven by a digital twin, which comprises the following steps: s1, designing an optimal transition shape of a fuel cell polar plate channel, determining the minimum fillet radius of each part of the channel, and manufacturing a primary forming die; s2, mounting the primary forming die on forming equipment and debugging; s3, loading liquid into the liquid chamber cavity; s4, controlling a high-speed impact compression device to compress a fluid medium to form high-energy-rate impact waves and initially forming the polar plate; s5, replacing the final forming die, and repeating the steps S2 to S4 to obtain a final fuel cell pole plate; and S6, regulating the forming precision through static hydraulic loading and pressure maintaining, and controlling the ultrasonic vibration device to generate mechanical oscillation so as to release the residual stress in the fuel cell pole plate. The invention realizes the improvement of the forming quality of the component and the reduction of the energy consumption.

Description

Digital twin driven fuel cell polar plate thermal vibration fluid energy-changing forming process

Technical Field

The invention relates to the technical field of digital twinning, in particular to a thermal vibration fluid energy-conversion forming process of a fuel cell polar plate driven by digital twinning.

Background

The machining method of the fuel cell pole plate in the market at present mainly takes machining represented by CNC and mould pressing forming as main parts. However, the pole plate prepared by the CNC process route has long time consumption, low efficiency, weak bending resistance and difficulty in realizing mass production, the die forming process is not mature, the conditions of cracking and damage of a blank are easy to occur in the die forming process, and the complex-feature high-precision micro punch has too high processing difficulty and too high cost, so that the pole plate die forming process route cannot meet the requirements of the current market. There is an increasing need for methods of forming fuel cell plates that achieve high quality and high efficiency.

Compared with the traditional processing method, the fluid impact forming technology has the advantages of short development period, high precision, low cost, high forming limit, good surface quality and the like, and is easier to form a metal sheet with a complex shape or higher precision requirement, thereby providing a new technical scheme for forming a high-quality and high-efficiency fuel cell pole plate. However, the influence of the process parameters on the forming in the fluid impact forming technology and how to improve and optimize the related control technology in the forming process are problems which are urgently needed to overcome at present.

The emergence of the digital twinning technology provides a new idea for controlling the forming process and forming better metal sheets. The digital twin technology describes a physical entity in a digital form and establishes a virtual model of the physical entity, the running state of the physical entity in a real environment is simulated by using data, and the physical entity is optimized by means of virtual reality interactive feedback, data fusion analysis, decision iterative optimization and the like, so that new performance is added or expanded to the physical entity. With the continuous development of digital twin technology, it is gradually applied to various fields such as machinery, medical treatment, and the like.

Therefore, the invention provides a thermal vibration fluid energy-changing forming process of a fuel cell pole plate driven by digital twins based on a fluid energy-changing loading forming technology and aiming at the fuel cell pole plate and combining the digital twins technology.

Chinese patent application publication no: CN114630211A discloses a digital twin-based fuel cell production system, comprising: the system comprises a fuel cell automatic production line, a data acquisition unit, a data cloud platform, a digital twin platform and a control terminal; the data acquisition unit acquires production process parameters in the fuel cell automatic production line and transmits the acquired data to the data cloud platform; the data cloud platform preprocesses the acquired data to form processed data and transmits the processed data to the digital twin platform; the digital twin platform carries a digital twin model and is used for constructing an equipment virtual model of the fuel cell automation production line; and the control terminal regulates and controls the technological parameters of the fuel cell automation production line and iterates the equipment virtual model. The system displays the virtual model of the equipment in the fuel cell automatic production line in a three-dimensional image mode through a digital twin technology to form a mapping linkage relation between processing data and the virtual model of the equipment, thereby being convenient for displaying the production parameter condition of each procedure in real time and being beneficial to real-time regulation and control and product quality optimization. Therefore, the fuel cell production system based on the digital twinning has the problems of unstable forming quality of the cell polar plate and high energy consumption.

Disclosure of Invention

Therefore, the invention provides a thermal vibration fluid energy-changing forming process of a fuel cell polar plate driven by a digital twin, which is used for overcoming the problems of unstable forming quality and overhigh energy consumption of the cell polar plate in the prior art.

In order to achieve the purpose, the invention provides a thermal vibration fluid energy-conversion forming process of a fuel cell polar plate driven by a digital twin, which comprises the following steps: s1, designing an optimal transition shape of a fuel cell polar plate channel, determining the minimum fillet radius of each part of the channel, and manufacturing a primary forming die; s2, mounting the primary forming die on forming equipment, debugging the primary forming die, placing a metal sheet at a corresponding position on the die after the debugging is finished, and controlling a positioning device to position the metal sheet on the die by a central control module; s3, injecting a fluid medium into the liquid chamber cavity until the fluid medium is full of the liquid chamber cavity, and controlling the electric heating device to heat the metal sheet by the central control module; s4, the central control module judges whether to adjust the preset pressing amount of the system or not according to the resilience amount of the stamped metal sheet in the historical data before stamping the metal sheet, and controls the high-speed impact compression device to compress the fluid medium to form high-energy-rate impact waves and enable the polar plate to be formed preliminarily;

s5, replacing and installing a preliminarily formed die, repeating the steps S2 to S4 to obtain a final fuel cell polar plate, when the central control module completes secondary adjustment of the preset pressing amount of the system, adjusting corresponding operation parameters in the punching device according to actual quality related parameters of the finally formed polar plate by the central control module, sending the corresponding operation parameters in the punching device to a machining deformation prediction model in a digital twin model after the adjustment is completed, simulating the polar plate forming process by the machining deformation prediction model according to the received operation parameters of the punching device, calculating machining deformation evaluation parameters of the polar plate to be formed and sending a calculation result to the central control module, and judging whether to secondarily adjust the corresponding operation parameters of the punching device or not by the central control module according to a comparison result of the calculation result and the machining deformation evaluation standard parameters; and S6, the central control module adjusts the forming precision of the fuel cell polar plate by static hydraulic loading and pressure maintaining after the fuel cell polar plate is formed and controls the ultrasonic vibration device to generate mechanical oscillation so as to release residual stress in the fuel cell polar plate.

Further, in step S4, before the metal sheet is stamped, the central control module determines whether to adjust the preset pressing amount of the system according to the springback amount P of the stamped metal sheet in the historical data, the central control module is provided with a preset first unit springback amount P1 and a preset second unit springback amount P2, where P1 is less than P2, and the springback amount P = Bm/Pm of the stamped metal sheet in the historical data is set, where Bm is the total pressing amount of the stamping device in a single period in the historical data, pm is the total springback amount of the metal sheet in the single period in the historical data,

if P is less than or equal to P1, the central control module judges that the rebound quantity of the stamped metal sheet in the historical data is within an allowable range, controls the stamping device to stamp the metal sheet and judges whether to adjust the impact load of the stamping device according to the fracture depth of the stamped pole plate;

if P1 is larger than P and is not larger than P2, the central control module judges that the rebound quantity of the stamped metal sheet in the historical data exceeds the allowable range, calculates the difference value delta P between the rebound quantity of the stamped metal sheet in the historical data and the preset unit rebound quantity, adjusts the preset pressing quantity of the system to a corresponding value according to delta P, and sets delta P = P-P1;

and if P is larger than P2, the central control module judges that the rebound quantity of the stamped metal sheet in the historical data exceeds an allowable range and controls the ultrasonic vibration device to prolong the mechanical vibration time.

Further, when the central control module finishes the judgment of whether the preset system pressing amount is adjusted and the springback amount P of the stamped metal sheet in the historical data meets P1 < P2, the preset system pressing amount is adjusted to a corresponding value according to the delta P, the central control module is provided with a preset first unit springback amount difference delta P1, a preset second unit springback amount difference delta P2, a preset first preset pressing amount adjusting coefficient gamma 1, a preset second preset pressing amount adjusting coefficient gamma 2 and a preset system pressing amount B0, wherein the delta P1 is less than the delta P2, the gamma 1 is more than 0 < gamma 2 < 1, and the delta P = P-P1= Bm/Pm-P1,

if the delta P is less than or equal to the delta P1, the central control module judges that the preset pressing amount of the system is not adjusted;

if the delta P1 is less than the delta P and less than or equal to the delta P2, the central control module judges that the gamma 2 is used for adjusting the preset pressing amount of the system;

if delta P is larger than delta P2, the central control module judges that gamma 1 is used for adjusting the preset pressing amount of the system;

when the central control module uses γ i to adjust the system preset depression amount B0, i =1,2 is set, and the adjusted system preset depression amount is recorded as B ', and B' = γ i × B0 is set.

Further, when the central control module finishes adjusting the preset system pressing amount, the central control module sends the adjusted preset system pressing amount to a machining deformation prediction model in a digital twin model, the machining deformation degree evaluation standard parameter of the machining deformation prediction model is recorded as A0, and A0= e × P0+ b × Q0+ c × D0 is set, wherein e is a rebound weight coefficient, and e =0.3mm is set ^-1 B is a fracture depth weight coefficient, and b =0.4mm is set ^-1 C is a wrinkle height weight coefficient, c =0.3mm ^-1 After the adjustment of the preset pressing amount of the system is finished, the central control module judges whether to perform secondary adjustment on the preset pressing amount of the system according to a processing deformation evaluation parameter Aa corresponding to the pole plate springback amount after final forming, and sets Aa = e × P '+ b × Q0+ c × D0, wherein P' is the pole plate springback amount after the pole plate is finally formed,

if Aa is less than A0, the central control module judges that the preset pressing amount of the system is secondarily adjusted, calculates the difference value delta Aa between the machining deformation evaluation parameter corresponding to the pole plate springback amount after the pole plate is finally formed and the machining deformation degree evaluation standard parameter in the digital twin model, secondarily adjusts the preset pressing amount of the system according to delta Aa, sets delta Aa = A0-Aa, and is provided with a preset first machining deformation evaluation parameter difference value delta Aa1, a preset second machining deformation evaluation parameter difference value delta Aa2, a preset third system pressing amount adjusting coefficient gamma 3 and a preset fourth system pressing amount adjusting coefficient gamma 4, wherein delta Aa1 is less than delta Aa2, gamma 1 is more than 0 and less than gamma 2 and less than gamma 3 and less than gamma 4,

if the delta Aa is less than or equal to the delta Aa1, the central control module judges that the preset pressing amount of the system is not subjected to secondary adjustment;

if the delta Aa is more than 1 and less than or equal to the delta Aa2, the central control module judges that the gamma 4 is used for carrying out secondary adjustment on the preset pressing amount of the system;

if delta Aa is more than delta Aa2, the central control module judges that gamma 3 is used for carrying out secondary adjustment on the preset system pressing amount;

when the central control module uses gamma i to secondarily adjust the preset system pressing amount, setting i =3,4, recording the adjusted preset system pressing amount as B ", and setting B" = gamma i × B';

and if Aa is larger than or equal to A0, the central control module does not perform secondary adjustment on the preset pressing amount of the system.

Further, in the step S4, when the central control module controls the punching device to punch the pole plate and the springback P of the punched metal sheet in the historical data satisfies that P is not more than P1, the central control module determines whether to adjust the impact load of the punching device according to the actual fracture depth Q of the punched pole plate, the central control module is provided with a preset first fracture depth Q1 and a preset second fracture depth Q2, wherein Q1 is less than Q2,

if Q is less than or equal to Q1, the central control module judges that the actual cracking depth of the polar plate is within an allowable range and controls a visual detector to detect the wrinkling height of the polar plate;

if Q1 is larger than Q and is not larger than Q2, the central control module judges that the actual fracture depth of the pole plate exceeds an allowable range, calculates the difference value delta Q between the actual impact load and the preset impact load, adjusts the impact load of the stamping device to a corresponding value according to the delta Q, and sets delta Q = Q-Q1;

if Q is more than Q2, the central control module judges that the actual fracture depth of the pole plate exceeds the allowable range and sends out a notice of stopping the operation of the equipment and repairing the equipment.

Further, when the central control module finishes the determination of whether the stamping load of the stamping device is adjusted and the actual fracture depth Q of the stamped pole plate meets the condition that Q1 is more than Q and less than or equal to Q2, the central control module adjusts the actual impact load R of the stamping device according to the difference delta Q between the actual fracture depth of the pole plate and the preset fracture depth, the central control module is provided with a preset first fracture depth difference delta Q1, a preset second fracture depth difference delta Q2, a preset first impact load adjusting coefficient alpha 1, a preset second impact load adjusting coefficient alpha 2 and a preset stamping device impact load R0, wherein delta Q1 is less than delta Q2, and alpha 1 is more than 0 and less than alpha 2 and less than 1,

if the delta Q is not more than the delta Q1, the central control module judges that the actual impact load of the stamping device is adjusted to R0;

if delta Q1 is less than delta Q and less than or equal to delta Q2, the central control module judges that alpha 2 is used for adjusting the actual impact load of the stamping device;

if delta Q is > -delta Q2, the central control module judges that alpha 1 is used for adjusting the actual impact load of the stamping device;

when the center control module adjusts the actual impact load R of the press device to a corresponding value using α i, i =1,2 is set, and the adjusted impact load is denoted as R ', and R' = R × α i is set.

Further, when the central control module finishes adjusting the impact load, the central control module sends the adjusted impact load to a machining deformation prediction model in a digital twin model, the central control module judges whether to carry out secondary adjustment on the impact load according to a machining deformation evaluation parameter Ab corresponding to the actual fracture depth of the finally-formed pole plate, ab = e × P "+ b × Q '+ c × D0 is set, wherein Q' is the actual fracture depth of the finally-formed pole plate after the impact load is adjusted,

if Ab is less than A0, the central control module judges to perform secondary adjustment on the impact load, calculates the difference value delta Ab between the machining deformation evaluation parameter corresponding to the actual fracture depth of the formed pole plate and the machining deformation degree evaluation standard parameter, judges whether to perform secondary adjustment on the impact load according to the delta Ab, and sets delta Ab = A0-Ab, the central control module is provided with a preset third machining deformation evaluation parameter difference value delta Aa3, a preset fourth machining deformation evaluation parameter difference value delta Aa4, a preset third impact load adjustment coefficient alpha 3 and a preset fourth impact load adjustment coefficient alpha 4, wherein the delta Aa3 is less than the delta Aa4, the alpha 1 is more than 0 and less than the alpha 2 and less than the alpha 3 and less than the alpha 4 and less than 1,

if the delta Ab is not more than delta Aa3, the central control module judges that the impact load is not subjected to secondary adjustment;

if delta Aa3 is less than delta Ab and less than or equal to delta Aa4, the central control module judges that alpha 4 is used for carrying out secondary adjustment on the impact load;

if delta Ab > -delta Aa4, the central control module judges that alpha 3 is used for carrying out secondary adjustment on the impact load;

when the central control module secondarily adjusts the impact load by using α i, setting i =3,4, recording the adjusted impact load as R ", and setting R" = α i × R';

and if Ab is larger than or equal to A0, the central control module does not perform secondary adjustment on the impact load.

Further, when the central control module completes the adjustment of the impact load of the punching device and the actual fracture depth Q of the punched polar plate meets the condition that Q is not more than Q1, the central control module judges whether to adjust the punching speed V or not according to the actual wrinkling height D of the punched polar plate, the central control module is provided with a first wrinkling height D1 and a second wrinkling height D2, wherein D1 is less than D2,

if D is less than or equal to D1, the central control module judges that the actual wrinkling height of the pole plate is within an allowable range and controls the punching device to perform normal punching operation on the pole plate;

if D1 is larger than D and smaller than D2, the central control module judges that the actual wrinkling height of the pole plate exceeds an allowable range, calculates the difference value delta D between the actual wrinkling height of the pole plate and the preset wrinkling height, adjusts the stamping speed to a corresponding value according to the delta D, and sets delta D = D-D1;

and if D is larger than D2, the central control module judges that the actual wrinkling height of the pole plate exceeds the allowable range and sends out a notice of stopping operation and overhauling.

Further, when the central control module finishes the judgment of whether the stamping speed is adjusted, the central control module adjusts the stamping speed according to the difference value delta D between the actual wrinkling height of the pole plate and the preset wrinkling height, and is provided with a preset first wrinkling height difference value delta D1, a preset second wrinkling height difference value delta D2, a preset first stamping speed adjusting coefficient beta 1, a preset second stamping speed adjusting coefficient beta 2 and a preset stamping speed V0, wherein delta D1 is less than delta D2,1 is less than beta 1 and less than beta 2,

if the delta D is less than or equal to the delta D1, the central control module judges that the stamping speed is adjusted to VO;

if the delta D1 is less than the delta D and less than or equal to the delta D2, the central control module judges that the stamping speed is adjusted by using the beta 1;

if DeltaD > DeltaD2, the central control module judges that beta 2 is used for adjusting the stamping speed;

when the center control module adjusts the press speed V using β j, j =1,2 is set, and the adjusted press speed is denoted as V ', and V' = V × β j is set.

Further, when the central control module finishes adjusting the punching speed, the central control module sends the adjusted punching speed to a machining deformation prediction model in a digital twin model and judges whether to perform secondary adjustment on the punching speed according to a machining deformation evaluation parameter Ac corresponding to the actual wrinkling height of the formed pole plate, ac = e × P "+ b × Q" + c × D0 is set, Q "is set as the actual fracture depth of the finally formed pole plate after the impact load is secondarily adjusted,

if Ac is less than A0, the central control module judges that the punching speed is secondarily adjusted, calculates the difference value delta Ac between the machining deformation evaluation parameter corresponding to the actual fracture depth of the formed pole plate and the machining deformation degree evaluation standard parameter, secondarily adjusts the impact load according to the delta Ac, and sets delta Ac = A0-Ac, the central control module is provided with a preset fifth machining deformation evaluation parameter difference value delta Aa5, a preset sixth machining deformation evaluation parameter difference value delta Aa6, a preset third punching speed adjusting coefficient beta 3 and a preset fourth punching speed adjusting coefficient beta 4, wherein the delta Aa5 is less than the delta Aa6, the beta 1 is more than 0 and less than the beta 2 and less than the beta 3 and less than the beta 4,

if the delta Ac is less than or equal to the delta Aa5, the central control module judges that the secondary adjustment is not carried out on the stamping speed;

if delta Ac is more than delta Aa5 and less than or equal to delta Aa6, the central control module judges that beta 4 is used for carrying out secondary adjustment on the stamping speed;

if the delta Ac & gt delta Aa6, the central control module judges that the secondary adjustment is carried out on the stamping speed by using beta 3;

when the central control module uses the beta j to secondarily regulate the punching speed, j =3,4 is set, the regulated punching speed is recorded as V ', V "= beta j × V' is set, and the actual wrinkling height of the formed polar plate corresponding to the secondarily regulated punching speed is calculated for the actual value of the machining deformation evaluation parameter when the central control module completes the secondary regulation of the punching speed; the actual value of the processing deformation degree evaluation parameter obtained through calculation is recorded as Az, az = e × P "+ b × Q" + c × D "is set, D" is the wrinkling height of the final-formed pole plate after the punching speed is secondarily adjusted, the central control module judges whether the punching speed needs to be further corrected according to the actual value of the processing deformation degree evaluation coefficient calculated according to the wrinkling height of the pole plate corresponding to the punching speed after secondary adjustment, and if Az is smaller than A0, the central control module judges that the preset pressing amount of the system is further adjusted until the processing deformation degree evaluation parameter meets the requirement and stops correction; if Az is larger than or equal to A0, the central control module judges that the quality of the pole plate after final forming meets the requirement and does not further adjust the preset pressing amount of the system;

and if Ac is larger than or equal to A0, the central control module does not perform secondary adjustment on the stamping speed.

Compared with the prior art, the process has the advantages that the preset unit rebound amount, the preset fracture depth and the preset wrinkling height are set, the preset pressing amount of the system can be adjusted according to the difference value of the actual unit rebound amount and the preset unit rebound amount, the current running state and the running result are simulated in the digital twin model, and the preset pressing amount of the system is secondarily adjusted according to the simulation result when the simulated running result does not meet the requirement; the actual impact load of the stamping device can be adjusted according to the difference value between the actual fracture depth and the preset fracture depth of the pole plate, the current running state and the running result are simulated in the digital twin model, and the impact load is secondarily adjusted according to the simulation result under the condition that the simulated running result does not meet the requirement; the method can adjust the punching speed according to the difference value between the actual wrinkling height and the preset wrinkling height of the polar plate, simulate the current running state and the running result in a digital twinning model, and secondarily adjust the punching speed according to the simulation result under the condition that the simulation running result does not meet the requirements, so that the digital twinning technology is integrated into the fuel cell polar plate thermal vibration fluid energy-changing forming process method and the accurate control of the quality of the cell polar plate are realized, the forming quality of a component is effectively controlled, and the improvement of the forming quality of the component and the reduction of energy consumption are realized.

Furthermore, the process of the invention can judge whether the preset pressing amount of the system is adjusted or not according to the springback amount of the stamped metal sheet in the historical data by setting the preset first unit springback amount and the preset second unit springback amount, thereby realizing the accurate adjustment of the preset pressing amount of the system, and further realizing the improvement of the forming quality of the component and the reduction of energy consumption.

Furthermore, according to the process, the preset first unit springback value difference value, the preset second unit springback value difference value, the preset first preset pressing amount adjusting coefficient, the preset second preset pressing amount adjusting coefficient and the preset system pressing amount are set, so that the preset system pressing amount can be adjusted according to the difference between the springback amount of the stamped metal sheet in the historical data and the preset unit springback amount, the preset system pressing amount can be accurately adjusted, and the forming quality of the component and the energy consumption can be further improved.

Furthermore, the process of the invention can judge whether to secondarily regulate the preset system pressing amount according to the processing deformation evaluation parameter corresponding to the pole plate springback amount after final forming by sending the regulated preset system pressing amount to the digital twin model, thereby realizing accurate control of the pole plate springback amount and further realizing improvement of component forming quality and reduction of energy consumption.

Furthermore, the process of the invention can judge whether to adjust the impact load of the punching device according to the actual fracture depth of the punched plate by setting the preset first fracture depth and the preset second fracture depth, so that the accurate judgment capability of whether to adjust the impact load is improved, the accurate control and repair of the fracture depth of the battery plate forming are realized, and the improvement of the component forming quality and the reduction of energy consumption are further realized.

Furthermore, the process of the invention can adjust the actual impact load of the stamping device according to the difference between the actual fracture depth of the polar plate and the preset fracture depth by setting the preset first fracture depth difference, the preset second fracture depth difference, the preset first impact load adjustment coefficient, the preset second impact load adjustment coefficient and the preset stamping device impact load, thereby realizing the accurate compensation of the fracture depth of the polar plate of the battery, and further realizing the improvement of the forming quality of the component and the reduction of energy consumption.

Furthermore, the process of the invention can judge whether to carry out secondary adjustment on the impact load according to the processing deformation evaluation parameter corresponding to the actual fracture depth of the finally-formed pole plate by sending the adjusted impact load to the digital twin model, thereby improving the accurate control capability on the fracture depth of the pole plate and further realizing the improvement on the forming quality of the component and the reduction on the energy consumption.

Furthermore, the process of the invention can judge whether to adjust the punching speed according to the actual wrinkling height of the punched polar plate by setting the first wrinkling height and the second wrinkling height, thereby realizing the accurate adjustment of the punching speed of the polar plate, improving the judgment capability of whether to adjust the punching speed, improving the accurate control capability of the forming quality of the polar plate, and further realizing the improvement of the forming quality of a component and the reduction of energy consumption.

Furthermore, the process of the invention can adjust the punching speed according to the difference value between the actual wrinkling height and the preset wrinkling height of the polar plate by setting the preset first wrinkling height difference value, the preset second wrinkling height difference value, the preset first punching speed adjusting coefficient, the preset second punching speed adjusting coefficient and the preset punching speed, thereby improving the control capability of the component forming quality and further realizing the improvement of the component forming quality and the reduction of energy consumption.

Furthermore, the process of the invention can judge whether to carry out secondary adjustment on the punching speed according to the processing deformation evaluation parameter corresponding to the actual wrinkling height of the formed polar plate by sending the adjusted punching speed to the digital twin model, thereby realizing the accurate control on the wrinkling height of the polar plate and the improvement on the forming quality of the polar plate, and further realizing the improvement on the forming quality of the component and the reduction on the energy consumption.

Drawings

FIG. 1 is an overall flow chart of a digital twin driven fuel cell plate thermal oscillation fluid energy-conversion forming process according to an embodiment of the invention;

FIG. 2 is a detailed flowchart of step S5 of the process for forming the thermal vibration fluid energy-changing of the fuel cell plate driven by the digital twin according to the embodiment of the present invention;

FIG. 3 is a schematic diagram of process data processing for a digital twinning driven fuel cell plate thermal oscillatory fluid energetics forming process according to embodiments of the present invention;

FIG. 4 is a flow chart of establishing a physical space model of the process for forming the thermal vibration fluid energy change of the fuel cell plate driven by the digital twin according to the embodiment of the invention.

Detailed Description

In order that the objects and advantages of the invention will be more clearly understood, the invention is further described below with reference to examples; it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and do not limit the scope of the present invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are only for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Fig. 1, fig. 2, fig. 3 and fig. 4 are a general flow chart, a specific flow chart of step S5, a schematic diagram of process data processing and a flow chart of establishing a physical space model of a digital twinning driven fuel cell plate thermal oscillation fluid energy conversion forming process according to an embodiment of the present invention. The invention relates to a thermal vibration fluid energy-changing forming process of a fuel cell polar plate driven by a digital twin, which comprises the following steps:

s1, designing an optimal transition shape of a fuel cell polar plate channel, determining the minimum fillet radius of each part of the channel, and manufacturing a primary forming die;

s2, mounting the primary forming die on forming equipment, debugging the primary forming die, placing a metal sheet at a corresponding position on the die after the debugging is finished, and controlling a positioning device to position the metal sheet on the die by a central control module;

s3, injecting a fluid medium into the liquid chamber until the fluid medium is full of the liquid chamber, wherein the central control module controls the electric heating device to heat the metal sheet;

s4, the central control module judges whether to adjust the preset pressing amount of the system or not according to the resilience amount of the stamped metal sheet in the historical data before stamping the metal sheet, and controls the high-speed impact compression device to compress the fluid medium to form high-energy-rate impact waves and enable the polar plate to be formed preliminarily;

s5, replacing and installing a preliminarily formed die, repeating the steps S2 to S4 to obtain a final fuel cell polar plate, when the central control module completes secondary adjustment of the preset pressing amount of the system, adjusting corresponding operation parameters in the punching device according to actual quality related parameters of the finally formed polar plate by the central control module, sending the corresponding operation parameters in the punching device to a machining deformation prediction model in a digital twin model after the adjustment is completed, simulating the polar plate forming process by the machining deformation prediction model according to the received operation parameters of the punching device, calculating machining deformation evaluation parameters of the polar plate to be formed and sending a calculation result to the central control module, and judging whether to secondarily adjust the corresponding operation parameters of the punching device or not by the central control module according to a comparison result of the calculation result and the machining deformation evaluation standard parameters;

and S6, the central control module adjusts the forming precision of the fuel cell polar plate by static hydraulic loading and pressure maintaining after the fuel cell polar plate is formed and controls the ultrasonic vibration device to generate mechanical oscillation so as to release residual stress in the fuel cell polar plate.

Specifically, the manufactured primary forming die is arranged in the forming equipment and used for providing a three-dimensional model of the battery plate to be formed; the positioning device is connected with the forming equipment and is used for positioning the position of the metal sheet on the die; the liquid chamber cavity is arranged in the primary forming die and is used for providing a place for injecting a fluid medium; the electric heating device is connected with the metal sheet and used for heating the metal sheet; the stamping device is connected with the primary forming die and is used for carrying out impact and compression operations on the metal sheet placed on the primary forming die through a fluid medium; and the ultrasonic vibration device is connected with the formed battery pole plate and used for releasing the residual stress of the battery pole plate.

The process has the advantages that by setting the preset unit rebound amount, the preset fracture depth and the preset wrinkling height, the preset pressing amount of the system can be adjusted according to the difference value between the actual unit rebound amount and the preset unit rebound amount, the current running state and the running result are simulated in the digital twin model, and the preset pressing amount of the system is secondarily adjusted according to the simulation result when the simulated running result does not meet the requirements; the actual impact load of the stamping device can be adjusted according to the difference value between the actual fracture depth and the preset fracture depth of the pole plate, the current running state and the running result are simulated in the digital twin model, and the impact load is secondarily adjusted according to the simulation result under the condition that the simulated running result does not meet the requirement; the method can adjust the punching speed according to the difference value between the actual wrinkling height and the preset wrinkling height of the polar plate, simulate the current running state and the running result in a digital twinning model, and secondarily adjust the punching speed according to the simulation result under the condition that the simulation running result does not meet the requirements, so that the digital twinning technology is integrated into the fuel cell polar plate thermal vibration fluid energy-changing forming process method and the accurate control of the quality of the cell polar plate are realized, the forming quality of a component is effectively controlled, and the improvement of the forming quality of the component and the reduction of energy consumption are realized.

As shown in fig. 1, in step S4, before the metal sheet is stamped, the central control module determines whether to adjust the preset pressing amount of the system according to the springback amount P of the stamped metal sheet in the historical data, where the central control module is provided with a preset first unit springback amount P1 and a preset second unit springback amount P2, where P1 is less than P2, and sets the springback amount P = Bm/Pm of the stamped metal sheet in the historical data, where Bm is the total pressing amount of the stamping device in a single cycle in the historical data, pm is the total springback amount of the metal sheet in a single cycle in the historical data,

if P is less than or equal to P1, the central control module judges that the rebound quantity of the punched metal sheet in the historical data is within an allowable range, controls the punching device to punch the metal sheet, and judges whether to adjust the impact load of the punching device according to the fracture depth of the punched plate;

According to the process, whether the preset pressing amount of the system is adjusted or not can be judged according to the resilience amount of the stamped metal sheet in the historical data by setting the preset first unit resilience amount and the preset second unit resilience amount, so that the accurate adjustment of the preset pressing amount of the system is realized, and the improvement of the forming quality of the component and the reduction of energy consumption are further realized.

Continuing to refer to fig. 1, when the central control module finishes the determination of whether to adjust the preset system pressing amount and the springback amount P of the stamped metal sheet in the historical data satisfies P1 < P ≦ P2, the preset system pressing amount is adjusted to a corresponding value according to Δ P, the central control module is provided with a preset first unit springback amount difference Δ P1, a preset second unit springback amount difference Δ P2, a preset first preset pressing amount adjustment coefficient γ 1, a preset second preset pressing amount adjustment coefficient γ 2, and a preset system pressing amount B0, wherein Δ P1 is less than Δ P2,0 < γ 1 < γ 2 < 1, and Δ P = P-P1= Bm/Pm-P1,

if the delta P1 is less than the delta P and is less than or equal to the delta P2, the central control module judges that gamma 2 is used for adjusting the preset pressing amount of the system;

when the central control module adjusts the system preset depression amount B0 by using γ i, i =1,2, and the adjusted system preset depression amount is recorded as B ', and B' = γ i × B0 is set.

According to the process, the preset first unit resilience difference value, the preset second unit resilience difference value, the preset first preset pressing amount adjusting coefficient, the preset second preset pressing amount adjusting coefficient and the preset system pressing amount are set, the preset system pressing amount can be adjusted according to the difference between the resilience of the stamped metal sheet in the historical data and the preset unit resilience, the preset system pressing amount can be accurately adjusted, and the forming quality of the component and the energy consumption can be further improved.

As shown in fig. 1, when the central control module finishes adjusting the preset system pressing amount, the central control module sends the adjusted preset system pressing amount to a machining deformation prediction model in the digital twin model, a machining deformation degree evaluation standard parameter of the machining deformation prediction model is marked as A0, and A0= e × P0+ b × Q0+ c × D0 is set, where e is a weight coefficient of the springback amount, and e =0.3mm is set ^-1 B is a weight coefficient of fracture depth, and b =0.4mm is set ^-1 C is a wrinkle height weight coefficient, c =0.3mm ^- After the adjustment of the preset pressing amount of the system is finished, the central control module judges whether to perform secondary adjustment on the preset pressing amount of the system according to a machining deformation evaluation parameter Aa corresponding to the pole plate springback amount after final forming, and sets Aa = e × P' + b × Q0+ c × D0,

wherein P' is the rebound quantity of the polar plate after the final formation of the polar plate,

if the delta Aa is less than or equal to the delta Aa1, the central control module judges that the secondary adjustment is not carried out on the preset pressing amount of the system;

if delta Aa is more than 1 and less than or equal to delta Aa2, the central control module judges that gamma 4 is used for carrying out secondary adjustment on the preset pressing amount of the system;

when the central control module uses gamma i to perform secondary adjustment on the preset system pressing amount, setting i =3,4, recording the adjusted preset system pressing amount as B ", and setting B" = gamma i × B';

According to the process, the adjusted system preset pressing amount is sent to the digital twin model, whether the system preset pressing amount is secondarily adjusted or not can be judged according to the machining deformation evaluation parameter corresponding to the pole plate springback amount after final forming, the pole plate springback amount is accurately controlled, and the forming quality of a component is further improved and the energy consumption is further reduced.

Continuing to refer to fig. 1, in step S4, when the central control module controls the punching device to punch the pole plate and the springback P of the punched metal sheet in the historical data satisfies that P is not more than P1, the central control module determines whether to adjust the impact load of the punching device according to the actual fracture depth Q of the punched pole plate, the central control module is provided with a preset first fracture depth Q1 and a preset second fracture depth Q2, wherein Q1 is less than Q2,

if Q1 is larger than Q and smaller than or equal to Q2, the central control module judges that the actual fracture depth of the pole plate exceeds an allowable range, calculates the difference value delta Q between the actual impact load and the preset impact load, adjusts the impact load of the stamping device to a corresponding value according to the delta Q, and sets delta Q = Q-Q1;

According to the process, whether the impact load of the stamping device is adjusted or not can be judged according to the actual fracture depth of the plate after stamping by setting the preset first fracture depth and the preset second fracture depth, so that the accurate judgment capability of whether the impact load is adjusted or not is improved, the accurate control and repair of the fracture depth of the battery plate forming are realized, and the improvement of the component forming quality and the reduction of energy consumption are further realized.

Continuing to refer to fig. 1, when the central control module completes the determination of whether to adjust the punching load of the punching device and the actual fracture depth Q of the punched pole plate satisfies Q1 < Q ≦ Q2, the central control module adjusts the actual impact load R of the punching device according to the difference Δ Q between the actual fracture depth of the pole plate and the preset fracture depth, the central control module is provided with a preset first fracture depth difference Δ Q1, a preset second fracture depth difference Δ Q2, a preset first impact load adjustment coefficient α 1, a preset second impact load adjustment coefficient α 2 and a preset punching device impact load R0, wherein Δ Q1 < Δ Q2,0 < α 1 < α 2 < 1,

if the delta Q is less than or equal to the delta Q1, the central control module judges that the actual impact load of the stamping device is adjusted to be R0;

if delta Q > -delta Q2, the central control module judges that alpha 1 is used for adjusting the actual impact load of the stamping device;

when the central control module adjusts the actual impact load R of the press device to a corresponding value using α i, i =1,2 is set, and the adjusted impact load is denoted as R ', and R' = R × α i is set.

According to the process, the preset first fracture depth difference value, the preset second fracture depth difference value, the preset first impact load adjusting coefficient, the preset second impact load adjusting coefficient and the preset impact load of the stamping device are set, the actual impact load of the stamping device can be adjusted according to the difference between the actual fracture depth and the preset fracture depth of the polar plate, the accurate compensation of the fracture depth of the polar plate of the battery is achieved, and the improvement of the forming quality of a component and the reduction of energy consumption are further achieved.

With reference to fig. 1, when the central control module finishes adjusting the impact load, the central control module sends the adjusted impact load to the machining deformation prediction model in the digital twin model, and the central control module determines whether to perform secondary adjustment on the impact load according to the machining deformation evaluation parameter Ab corresponding to the actual fracture depth of the final-formed pole plate, and sets Ab = e × P "+ b × Q '+ c × D0, where Q' is the actual fracture depth of the final-formed pole plate after adjusting the impact load,

if Ab is less than A0, the central control module judges to carry out secondary adjustment on the impact load, calculates the difference value delta Ab between the machining deformation evaluation parameter corresponding to the actual fracture depth of the formed pole plate and the machining deformation degree evaluation standard parameter, judges whether to carry out secondary adjustment on the impact load according to the delta Ab, sets delta Ab = A0-Ab, and is provided with a preset third machining deformation evaluation parameter difference value delta Aa3, a preset fourth machining deformation evaluation parameter difference value delta Aa4, a preset third impact load adjustment coefficient alpha 3 and a preset fourth impact load adjustment coefficient alpha 4, wherein the delta Aa3 is less than the delta Aa4, the alpha 1 is more than 0 and less than the alpha 2 and less than the alpha 3 and less than the alpha 4,

when the central control module uses the α i to perform secondary adjustment on the impact load, setting i =3,4, recording the adjusted impact load as R ", and setting R" = α i × R';

According to the process, the adjusted impact load is sent to the digital twin model, whether the impact load is secondarily adjusted or not can be judged according to the machining deformation evaluation parameter corresponding to the actual fracture depth of the finally-formed polar plate, the accurate control capability of the fracture depth of the polar plate is improved, and the improvement of the component forming quality and the reduction of energy consumption are further realized.

Continuing to refer to fig. 1, when the central control module completes the adjustment of the impact load of the punching device and the actual fracture depth Q of the punched plate satisfies Q is less than or equal to Q1, the central control module determines whether to adjust the punching speed V according to the actual wrinkling height D of the punched plate, the central control module is provided with a first wrinkling height D1 and a second wrinkling height D2, wherein D1 is less than D2,

if D is larger than D2, the central control module judges that the actual wrinkling height of the pole plate exceeds the allowable range and sends out a stop operation and maintenance notice.

According to the process, the first wrinkling height and the second wrinkling height are set, whether the punching speed is adjusted or not can be judged according to the actual wrinkling height of the punched polar plate, the accurate adjustment of the punching speed of the polar plate is achieved, the judging capability of whether the punching speed is adjusted or not is improved, the accurate control capability of the polar plate forming quality is improved, and the improvement of the component forming quality and the reduction of energy consumption are further achieved.

Referring to fig. 1, when the central control module finishes determining whether to adjust the stamping speed, the central control module adjusts the stamping speed according to a difference Δ D between the actual wrinkling height of the plate and the preset wrinkling height, and the central control module is provided with a preset first wrinkling height difference Δ D1, a preset second wrinkling height difference Δ D2, a preset first stamping speed adjustment coefficient β 1, a preset second stamping speed adjustment coefficient β 2, and a preset stamping speed V0, where Δ D1 is less than Δ D2,1 < β 2,

if delta D1 is less than delta D and less than or equal to delta D2, the central control module judges that beta 1 is used for adjusting the stamping speed;

According to the process, the preset first wrinkling height difference value, the preset second wrinkling height difference value, the preset first stamping speed adjusting coefficient, the preset second stamping speed adjusting coefficient and the preset stamping speed are set, so that the stamping speed can be adjusted according to the difference between the actual wrinkling height and the preset wrinkling height of the polar plate, the control capacity of the forming quality of the component is improved, and the forming quality of the component is further improved and the energy consumption is further reduced.

With reference to fig. 1, when the central control module finishes adjusting the punching speed, the central control module sends the adjusted punching speed to the machining deformation prediction model in the digital twin model and determines whether to perform secondary adjustment on the punching speed according to the machining deformation evaluation parameter Ac corresponding to the actual crinkling height of the formed plate, ac = e × P "+ b × Q" + c × D0 is set, Q "is the actual fracture depth of the finally formed plate after secondary adjustment on the punching load,

when the central control module uses the beta j to perform secondary adjustment on the punching speed, setting j =3,4, recording the adjusted punching speed as V ", setting V" = beta j × V', and calculating the actual wrinkling height of the formed polar plate corresponding to the secondarily adjusted punching speed when the central control module completes the secondary adjustment on the punching speed; recording the calculated actual value of the machining deformation degree evaluation parameter as Az, setting Az = e × P "+ b × Q" + c × D ", wherein D" is the wrinkling height of the final-formed pole plate after the punching speed is secondarily adjusted, judging whether the punching speed needs to be further corrected or not by the central control module according to the machining deformation degree evaluation coefficient actual value calculated according to the wrinkling height of the pole plate corresponding to the punching speed after the secondary adjustment, and if Az is less than A0, judging that the system preset pressing amount needs to be further adjusted by the central control module until the machining deformation degree evaluation parameter meets the requirement and then stopping correction; if Az is larger than or equal to A0, the central control module judges that the quality of the pole plate after final forming meets the requirement and does not further adjust the preset pressing amount of the system;

and if Ac is more than or equal to A0, the central control module does not perform secondary adjustment on the punching speed.

According to the process, the adjusted stamping speed is sent to the digital twin model, whether the stamping speed is secondarily adjusted or not can be judged according to the processing deformation evaluation parameter corresponding to the actual wrinkling height of the formed polar plate, the accurate control on the wrinkling height of the polar plate and the improvement on the forming quality of the polar plate are realized, and the improvement on the forming quality of a component and the reduction on energy consumption are further realized.

Referring to fig. 3 and 4, before the sheet metal is processed, the central control module constructs a physical space model of the thermal vibration fluid energy conversion forming process according to the collected related process operation parameters and the production data of the sheet metal, wherein the constructing of the physical space model of the thermal vibration fluid energy conversion forming process comprises the following steps:

step a, establishing a relevant database:

collecting historical production data of the metal sheet, and establishing a blank database, wherein the blank database comprises blank geometric parameters, physical attribute parameters and state parameters so as to embody the parameters of the shape, the size, the mechanical behavior and the like of the blank;

acquiring basic parameters of a thermal vibration fluid energy-variable forming die and equipment, and establishing a thermal vibration fluid energy-variable forming die and equipment database;

acquiring historical processing deformation of the metal sheet and historical process parameters in the variable-energy forming process of the thermal-vibration fluid, and establishing a database of the variable-energy forming process of the thermal-vibration fluid;

b, obtaining a machining deformation prediction model based on deep learning training according to the historical machining deformation of the metal sheet and the historical process parameters in the thermal vibration fluid variable energy forming process;

c, starting a thermal vibration fluid energy-variable forming test, and collecting real-time process parameters in the thermal vibration fluid energy-variable forming process, wherein the parameters comprise impact load, blank holder force and temperature, and the parameters are collected in real time through a pressure sensor and a temperature sensor;

d, establishing a physical space model of the thermal vibration fluid variable energy forming process according to a blank database, a thermal vibration fluid variable energy forming die and equipment database, historical process parameters in the thermal vibration fluid variable energy forming process and real-time process parameters in the thermal vibration fluid variable energy forming process;

e, constructing a digital twin model according to the physical space model;

step f, inputting the real-time process parameters into a machining deformation prediction model to obtain a sheet metal machining deformation state prediction value of the thermal vibration fluid variable energy forming process;

and g, correcting real-time process parameters in the variable energy forming process of the thermal vibration fluid according to the predicted value of the machining deformation state of the metal sheet and the digital twin model.

The blank database comprises blank geometric parameters, physical attribute parameters and state parameters so as to embody the parameters of the shape, the size, the mechanical behavior and the like of the blank; the database of the hot-vibration fluid variable-energy forming process comprises historical impact load, historical blank holder force, historical temperature, historical blank wall thickness thickening amount, historical blank wall thickness thinning amount and historical blank profile deviation amount; the basic parameters of the thermal vibration fluid energy-variable forming die and the equipment comprise equipment geometric parameters, equipment physical attribute parameters, machine tool natural frequency, die geometric parameters and die physical attribute parameters.

Referring to fig. 3, before processing the metal sheet, a processing deformation prediction model is obtained based on deep learning training, and the method specifically includes the steps of:

step 1, establishing a deep learning model based on a BP neural network in Matlab, wherein an algorithm function is a thingdm function, a sigmoid transfer function is used between an input layer and a hidden layer, purelin transfer functions are adopted for the hidden layer and an output layer, a training error is set to be 0.001, and a training rate is 0.1;

step 2, obtaining a data sample by further classifying and analyzing according to the blank length l, the blank width w, the blank thickness t, the material strength coefficient K, the material thickness anisotropy index r, the friction coefficient mu, the historical impact load Ph, the historical blank holder force Qh, the historical temperature Th, the real-time amplitude phi n, the real-time frequency psi n, the historical blank wall thickness thickening quantity delta h, the historical blank wall thickness thinning quantity epsilon h and the historical blank profile deviation quantity theta h as original network training data, wherein the historical blank wall thickness thickening quantity delta h, the historical blank wall thickness thinning quantity epsilon h and the historical blank profile deviation quantity theta h are set values;

step 3, continuously transmitting the error between the set value and the actual output value in the forward and reverse directions according to the characteristics of the BP network, and further continuously correcting the corresponding weight and threshold in the algorithm until the error meets the requirements, and finishing the training;

and 4, finally generating a mapping relation between the input value and the output value as a machining deformation prediction model.

Referring to fig. 3, the central control module constructs a digital twin model according to the constructed physical space model, and the specific steps include: the process of constructing the digital twin model according to the physical space model is that the physical space model is combined with a Matlab simulation platform to construct a 3D mirror model, so that the 3D virtual model is matched with the 3D mirror model, the 3D mirror model is driven to act according to the running parameters of an entity according to the 3D virtual model, the Matlab is used for continuously reading storage space data and then transmitting the storage space data to the 3D mirror model to realize synchronous running with forming and processing, and the monitoring and control of the real-time processing process can be realized through visual operation.

Referring to fig. 3, in the process of processing the metal sheet, the method for correcting the process parameters of the thermal vibration fluid energy-converting forming process includes the following steps:

setting the normal working range of the processing deformation prediction model, including wrinkling, cracking and springback ranges;

further, collecting real-time process parameters in the liquid filling and forming process again;

inputting the real-time process parameters into the digital twin model to obtain twin process parameters in the variable energy forming process of the thermal vibration fluid;

inputting twin process parameters of the thermal vibration fluid energy-variable forming process into the machining deformation prediction model, performing preliminary optimization to obtain optimized process parameters, and correcting the real-time process parameters;

inputting the optimized technological parameters into the machining deformation prediction model to obtain a predicted value of the machining deformation state of the metal sheet;

judging whether the predicted value of the machining deformation state of the metal sheet is within the normal working range of the machining deformation prediction model;

and determining whether to correct the technological parameters of the variable energy forming process of the thermal vibration fluid according to the judgment result.

Specifically, the method for judging whether the predicted value of the machining deformation state of the sheet metal is in the normal working range of the machining deformation prediction model comprises the following steps: and when the predicted value of the machining deformation state of the metal sheet exceeds the normal working range of the machining deformation prediction model, immediately stopping machining the component, correcting the technological parameters of the thermal vibration fluid energy-variable forming process, inputting the optimized technological parameters into the machining deformation prediction model to obtain the predicted value of the machining deformation state of the metal sheet, judging again until the predicted value of the machining deformation state of the metal sheet is within the normal working range of the machining deformation prediction model, continuously machining the component, and obtaining the metal sheet meeting the requirements.

The invention provides a digital twin driven fuel cell polar plate thermal vibration fluid energy-changing forming process, which realizes prediction and control of metal sheet forming by data interaction between the thermal vibration fluid energy-changing forming process and a digital twin body. The digital twin-driven fuel cell polar plate thermal vibration fluid energy-changing forming process can quickly optimize the process flow in the fuel cell polar plate thermal vibration fluid energy-changing forming process, and finally realizes the purposes of reducing energy consumption and cost and improving processing efficiency and quality. Compared with the prior art, the method has the advantages that the digital twinning technology is integrated into the fuel cell pole plate thermal vibration fluid energy-changing forming process method, the process flow can be rapidly optimized in the forming process, the forming quality of components can be effectively controlled, and the problems of the demonstration production application and the technical industrialization of the actual fuel cell pole plate are effectively solved.

Example 1

The specific application of the fuel cell plate thermal vibration fluid energy-changing forming process driven by digital twinning in the aspect of fuel cell plate fracture is disclosed.

(1) The method for constructing the digital twin model of the fuel cell plate thermal vibration fluid energy-changing forming process comprises the following steps:

step a, establishing a relevant database:

collecting historical production data of a metal sheet, and establishing a blank database, wherein the blank database comprises a blank length l, a blank width w, a blank thickness t, a material strength coefficient K, a material thickness anisotropy index r and a friction coefficient mu;

obtaining historical processing deformation of a metal sheet and historical process parameters in the process of variable energy forming of hot-vibration fluid, and establishing a database of the variable energy forming process of the hot-vibration fluid, wherein the database comprises historical impact load Ph, historical blank holder force Qh, historical temperature Th, real-time amplitude phi n, real-time frequency psi n, historical blank wall thickness thickening quantity delta h, historical blank wall thickness thinning quantity epsilon h and historical blank surface deviation quantity theta h;

b, obtaining a machining deformation prediction model based on deep learning training according to the historical machining deformation of the metal sheet and the historical process parameters in the variable energy forming process of the hot-vibration fluid;

c, starting a thermal vibration fluid variable energy forming test, and collecting real-time process parameters including impact load Pn, blank holder force Qn and temperature Tn in the thermal vibration fluid variable energy forming process in real time through a pressure sensor and a temperature sensor;

e, constructing a digital twin model according to the physical space model, constructing a 3D mirror image model by combining the physical space model with a Matlab simulation platform, matching the 3D virtual model with the 3D mirror image model, driving the 3D mirror image model to act according to the running parameters of an entity according to the 3D virtual model, continuously reading storage space data through the Matlab, and transmitting the data to the 3D mirror image model to realize synchronous running with forming processing;

step f, inputting real-time process parameters including real-time impact load Pn, real-time blank holder force Qn and real-time temperature Tn into a machining deformation prediction model to obtain predicted reduction of the wall thickness of the metal sheet of the thermal vibration fluid variable energy forming process;

and g, correcting real-time process parameters including impact load Pn, blank holder force Qn and temperature Tn in the variable energy forming process of the thermal vibration fluid according to the wall thickness reduction amount of the metal sheet blank and the digital twinning model.

(2) The design process of the thermal vibration fluid energy-changing forming process channel of the fuel cell polar plate driven by the digital twin comprises the following steps:

designing a transition section of a fuel cell polar plate channel and preliminarily setting the radius R of round corners at each part of the channel;

setting a normal working range of the processing deformation prediction model for fracture;

simulating a fluid impact forming process in a twin space, and acquiring real-time fillet radii Rn of all parts of a channel by adopting an infrared distance measuring sensor;

inputting the real-time process parameters including real-time impact load Pn, real-time blank holder force Qn, real-time temperature Tn and real-time fillet radius Rn into the digital twin model to obtain twin process parameters in the variable energy forming process of the thermal vibration fluid;

inputting the optimized process parameters into the machining deformation prediction model to obtain the predicted thinning amount of the metal sheet wall thickness;

judging whether the predicted thinning amount of the wall thickness of the metal sheet is within the normal working range of the fracture of the machining deformation prediction model;

and determining whether to correct the technological parameters of the variable energy forming process of the thermal vibration fluid according to the judgment result. And finally obtaining the minimum radius R of all round corners of the optimal channel.

(3) The primary forming process of the fuel cell polar plate thermal vibration fluid energy-changing forming process driven by the digital twin comprises the following steps:

installing a primary forming die on the liquid-filling forming equipment, debugging, and placing a metal sheet on the primary forming die and positioning the metal sheet through a positioning device after the debugging is finished;

continuously loading liquid into the liquid chamber cavity until the liquid chamber cavity is filled, and simultaneously heating the metal sheet in an electric heating mode;

setting a normal working range of the processing deformation prediction model fracture, and obtaining the normal working range according to a blank material determination forming limit diagram;

compressing a fluid medium by a high-speed impact compression device to form high-energy-rate shock waves, forming a polar plate, and acquiring real-time process parameters including real-time impact load, real-time blank holder force and real-time temperature in the variable energy forming process of the thermal vibration fluid in real time by using a pressure sensor and a temperature sensor;

inputting the optimized technological parameters into the machining deformation prediction model to obtain the predicted thinning amount of the wall thickness of the metal sheet;

judging whether the predicted thinning amount of the wall thickness of the metal sheet is within the normal working range of the fracture of the machining deformation prediction model or not;

(4) Replacing the final forming die, and repeating the step (3) to obtain a final fuel cell polar plate;

(5) The static pressure forming processing of the thermal vibration fluid energy-changing forming process of the fuel cell polar plate driven by the digital twin comprises the following steps:

after forming, static hydraulic loading and pressure maintaining are carried out to improve the forming precision, wherein the pressure of a liquid chamber is 5 to 30MPa;

adopting an ultrasonic vibration device to generate mechanical oscillation, and acquiring real-time process parameters in the ultrasonic vibration process, wherein the real-time process parameters comprise real-time amplitude phi n and real-time frequency psi n;

inputting the real-time process parameters including real-time impact load Pn, real-time blank holder force Qn, real-time temperature Tn, real-time amplitude phi n and real-time frequency psi n into the digital twin model to obtain twin process parameters in the ultrasonic vibration forming process;

inputting twin process parameters in the ultrasonic vibration forming process into the machining deformation prediction model, performing preliminary optimization to obtain optimized process parameters, and correcting the real-time process parameters;

(6) And when the predicted thinning amount of the wall thickness of the metal sheet exceeds the normal fracture working range of the machining deformation prediction model, immediately stopping machining the component, correcting process parameters in the variable energy forming process of the hot vibration fluid, continuously executing 'inputting optimized process parameters into the machining deformation prediction model to obtain the predicted thinning amount of the wall thickness of the metal sheet' until the predicted thinning amount of the wall thickness of the metal sheet is within the normal fracture working range of the machining deformation prediction model, continuously machining the component, and obtaining the metal sheet meeting the requirements.

Example 2

In the digital twinning-driven fuel cell plate thermal vibration fluid energy-changing forming process of the embodiment, after the central control module finishes adjusting the preset system depression amount, the central control module determines whether to perform secondary adjustment on the preset system depression amount according to the machining deformation evaluation parameter corresponding to the pole plate rebound amount after final forming, and corrects the preset system depression amount according to the difference between the rebound amount of the pole plate and the preset unit rebound amount when determining that Aa is less than A0', wherein A0' is a machining deformation degree evaluation parameter after adjusting the preset system depression amount, in the embodiment, aa =6 is calculated by the central control module, at this time, the central control module determines that Aa is less than A0', and is provided with a preset first unit rebound amount difference value P1, a preset second unit rebound amount difference value P2, a preset third preset depression amount adjustment coefficient γ 3, a preset fourth preset depression amount = γ 4 and a preset machining deformation degree =0.7cm =0.9, and a standard pressure is set as a1, a preset depression amount = a 1= a2, a preset depression amount = a 1= a preset Δ =0.9, a standard depression amount is set, a 1= 9.7 cm, a1 is set as a single time, a system depression amount is set,

in this embodiment, the central control module obtains Δ P "=0.8cm, and at this time, the central control module determines Δ P" > < Δ P2 and adjusts B' by using γ 3, where the adjusted system preset depression amount is denoted as B ", and B" =0.8 × 9cm =7.2cm is set.

According to the invention, the preset third preset pressing amount regulating coefficient and the preset fourth preset pressing amount regulating coefficient are set, and the preset system pressing amount is corrected in time according to the change of parameters in the actual forming process by monitoring the quality of the metal sheet, so that the strict monitoring of the forming quality of the component is realized, the accurate correction capability of the resilience amount of the polar plate is improved, and the improvement of the forming quality of the component and the reduction of energy consumption are further realized.

So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention; various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal vibration fluid energy-conversion forming process for a fuel cell polar plate driven by a digital twin is characterized by comprising the following steps:

and S6, the central control module adjusts the forming precision of the fuel cell pole plate by static hydraulic loading and pressure maintaining after the fuel cell pole plate is formed and controls the ultrasonic vibration device to generate mechanical oscillation so as to release the residual stress in the fuel cell pole plate.

2. The process of claim 1, wherein in step S4, before the stamping of the metal sheet, the central control module determines whether to adjust the preset pressing amount of the system according to the springback amount P of the stamped metal sheet in the historical data, and the central control module is provided with a preset first unit springback amount P1 and a preset second unit springback amount P2, wherein P1 is less than P2, and the springback amount P = Bm/Pm of the stamped metal sheet in the historical data is set, where Bm is the total pressing amount of the stamping device in a single cycle in the historical data, pm is the total springback amount of the metal sheet in a single cycle in the historical data,

3. The digital twin driven fuel cell plate thermooscillation fluid variable energy forming process according to claim 2, wherein when the central control module completes the determination of whether to adjust the system preset amount of depression and the spring back amount P of the stamped metal sheet in the historical data satisfies P1 < P ≦ P2, the system preset amount of depression is adjusted to a corresponding value according to Δ P, the central control module is provided with a preset first unit spring back amount difference Δ P1, a preset second unit spring back amount difference Δ P2, a preset first preset amount of depression adjustment coefficient γ 1, a preset second preset amount of depression adjustment coefficient γ 2, and a system preset amount of depression B0, wherein Δ P1 < [ delta ] P2,0 < γ 1 < γ 2 < 1, Δ P = P-P1= Bm/Pm-P1,

4. The digital twin driven fuel cell plate thermal vibration fluid energy-changing forming process according to claim 3, wherein when the central control module completes the adjustment of the system preset depression amount, the central control module sends the adjusted system preset depression amount to a machining deformation prediction model in the digital twin model, the machining deformation degree evaluation standard parameter of the machining deformation prediction model is recorded as A0, and A0= e x P0+ b x Q0+ c x D0 is set, wherein e is a rebound weight coefficient, and e =0.3mm ^-1 B is a fracture depth weight coefficient, and b =0.4mm is set ^-1 C is a wrinkle height weight coefficient, and c =0.3mm is set ^-1 After the adjustment of the preset pressing amount of the system is finished, the central control module judges whether to perform secondary adjustment on the preset pressing amount of the system according to a processing deformation evaluation parameter Aa corresponding to the pole plate springback amount after final forming, and sets Aa = e × P '+ b × Q0+ c × D0, wherein P' is the pole plate springback amount after the pole plate is finally formed,

if Aa is less than A0, the central control module judges that the preset pressing amount of the system is secondarily adjusted, calculates the difference value delta Aa between the machining deformation evaluation parameter corresponding to the rebound amount of the polar plate after the final formation of the polar plate and the machining deformation degree evaluation standard parameter in the digital twin model, secondarily adjusts the preset pressing amount of the system according to delta Aa, sets delta Aa = A0-Aa, and is provided with a preset first machining deformation evaluation parameter difference value delta Aa1, a preset second machining deformation evaluation parameter difference value delta Aa2, a preset third system pressing amount adjusting coefficient gamma 3 and a preset fourth system pressing amount adjusting coefficient gamma 4, wherein the delta Aa1 is less than the delta Aa2, the gamma 1 is more than 0 and less than the gamma 2 and less than the gamma 3 and less than the gamma 4,

5. The digital twinning-driven fuel cell pole plate thermal vibration fluid energy-conversion forming process as claimed in claim 4, wherein in the step S4, when the central control module controls the punching device to punch the pole plate and the springback P of the punched metal sheet in the historical data satisfies P ≤ P1, the central control module determines whether to adjust the impact load of the punching device according to the actual cracking depth Q of the punched pole plate, the central control module is provided with a preset first cracking depth Q1 and a preset second cracking depth Q2, wherein Q1 is less than Q2,

6. The digital twin driven fuel cell plate thermooscillation fluid energy-conversion forming process according to claim 5, wherein when the central control module completes the determination of whether to adjust the stamping load of the stamping device and the actual fracture depth Q of the stamped plate satisfies Q1 < Q2, the central control module adjusts the actual impact load R of the stamping device according to the difference DeltaQ between the actual fracture depth of the plate and the preset fracture depth, the central control module is provided with a preset first fracture depth difference DeltaQ 1, a preset second fracture depth difference DeltaQ 2, a preset first impact load adjusting coefficient alpha 1, a preset second impact load adjusting coefficient alpha 2 and a preset stamping device impact load R0, wherein DeltaQ 1 < DeltaQ 2,0 < alpha 1 < alpha 2 < 1,

7. The digital twin driven fuel cell pole plate thermal vibration fluid energy-conversion forming process according to claim 6, wherein when the central control module completes the adjustment of the impact load of the punching device and the actual fracture depth Q of the punched pole plate satisfies Q < Q1, the central control module determines whether to adjust the punching speed V according to the actual wrinkling height D of the punched pole plate, the central control module is provided with a first wrinkling height D1 and a second wrinkling height D2, wherein D1 < D2,

if D1 is more than D and less than D2, the central control module judges that the actual wrinkling height of the pole plate exceeds an allowable range, calculates the difference value delta D between the actual wrinkling height of the pole plate and the preset wrinkling height, adjusts the punching speed to a corresponding value according to the delta D, and sets the delta D = D-D1;

8. The thermal oscillation fluid energy-changing forming process of the pole plate of the digital twinning driven fuel cell according to claim 7, wherein when the central control module completes the determination of whether to adjust the stamping speed, the central control module adjusts the stamping speed according to the difference Δ D between the actual wrinkling height of the pole plate and the preset wrinkling height, the central control module is provided with a preset first wrinkling height difference Δ D1, a preset second wrinkling height difference Δ D2, a preset first stamping speed adjusting coefficient β 1, a preset second stamping speed adjusting coefficient β 2 and a preset stamping speed V0, wherein Δ D1 is less than Δ D2,1 is less than β 1 and less than β 2,

if the delta D is less than or equal to the delta D1, the central control module judges that the stamping speed is adjusted to be V0;

if DeltaD > DeltaD2, the central control module judges that beta 2 is used for adjusting the punching speed;

when the center control module adjusts the pressing speed V using β j, j =1,2, and the adjusted pressing speed is denoted as V ', and V' = V × β j is set.