A magnetic forming device for preparing electromagnetic shielding sealing strip

Abstract

The invention discloses a magnetic forming device for preparing an electromagnetic shielding sealing strip, comprising an electric control cabinet, a chassis, a semi-enclosed magnetic yoke, a conductive coil and a height adjustment component. A bridge rectifier, a transformer, a touch screen, an ammeter, a thyristor and a PLC controller are arranged in the electric control cabinet. The chassis half covers the semi-enclosed magnetic yoke. The semi-enclosed magnetic yoke is nearly C-shaped as a whole, and comprises an upper magnetic yoke, a lower magnetic yoke and a connecting magnetic yoke arranged horizontally. The height adjustment component comprises a positioning frame, a guide rod and guide sleeve component, a screw and screw sleeve component, and a distance adjustment plate movably connected to the lower end of the screw. The magnetic forming device can control the magnetic flux intensity of the magnetic field with the help of the current size to pull ferromagnetic conductive particles, and after adjusting the current parameters and the magnetic yoke distance parameters, a linear regression model is used for mathematical modeling and fitting after multiple groups of sampling training, so that the electric control parameters can be quickly obtained, and an electromagnetic shielding sealing strip with a nearly "△" or nearly "∩" directional orientation can be obtained according to the change of the current intensity, and the applicability is wide.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic shielding sealing strip production, and in particular to a magnetic forming device for preparing electromagnetic shielding sealing strips. Background Art

[0002] Electromagnetic shielding sealing strips or electromagnetic shielding gaskets, as sealing materials and electromagnetic shielding materials for electronic products, have been widely recognized by the market and are mainly used in automotive, radar, power amplifier, military industry, communication base stations, high-frequency signal shielding and other fields. Traditional sealing strips are mostly made of silicone material, and tiny particles or flaky ferromagnetic conductive particles are doped in the sealing strips. The magnetic field magnetization effect is used to make the ferromagnetic conductive particles obtain a magnetizing effect, causing all ferromagnetic conductive particles to produce weak magnetic poles, and then the two adjacent ferromagnetic conductive particles attract each other with opposite poles, and all ferromagnetic conductive particles are positioned according to the direction of the magnetic flux lines and solidified and shaped. After being applied to electronic products, the electromagnetic signals that pass through the gaps of the traditional electromagnetic sealing strips can be completely shielded after this directional shaping, and the application effect is excellent. At present, such electromagnetic shielding sealing strips or electromagnetic shielding gaskets are rarely seen on the market, and there is no dedicated production and preparation equipment, so the application prospects are broad.

[0003] To this end, in the production of a new type of electromagnetic shielding sealing strip, the ferromagnetic conductive particles need to be magnetized and uniformly oriented in a magnetic field before molding, and this type of electromagnetic shielding sealing strip is immediately shaped after magnetization, so the unshaped sealing strip material needs to be initially shaped through a magnetization process. Therefore, it is necessary to design an adsorption device that can assist the electromagnetic shielding sealing strip in the initial shaping. Summary of the invention

[0004] The purpose of the present invention is to enable the ferromagnetic conductive particles in the electromagnetic shielding strip formed by dispensing to be uniformly oriented after magnetization, fully shield the electromagnetic signals passing through the gaps, and improve the electromagnetic interference problem of the existing electromagnetic shielding strip. It is proposed to design an adsorption device that can assist the electromagnetic shielding sealing strip in the initial shaping.

[0005] The technical solutions adopted to solve the above problems are:

[0006] A magnetic forming device for preparing an electromagnetic shielding sealing strip comprises an electric control cabinet, a chassis, a semi-enclosed magnetic yoke, a conductive coil and a height adjustment component.

[0007] The electric control cabinet is equipped with a bridge rectifier, a transformer, a touch screen, an ammeter, a thyristor, and a PLC controller, which are used to conduct direct current to the conductive coil and control the power supply current of the conductive coil and the fault alarm reminder.

[0008] The chassis half covers the semi-enclosed magnetic yoke, and the semi-enclosed magnetic yoke is nearly C-shaped as a whole, including a horizontally arranged upper magnetic yoke, a lower magnetic yoke and a connecting magnetic yoke arranged vertically at the rear end. The rear end of the upper magnetic yoke surrounds the upper half of the conductive coil, the rear end of the lower magnetic yoke surrounds the lower half of the conductive coil, and the middle section of the connecting magnetic yoke surrounds the middle section of the conductive coil, so that the conductive coil after power is turned on will generate a magnetic field in a nearly C-shaped magnetic yoke, and the direction of the magnetic flux line is uniformly vertically transmitted from the N pole of the lower magnetic yoke to the S pole of the upper magnetic yoke, and the electromagnetic shielding strips on the feeding conveyor belt between the upper magnetic yoke and the lower magnetic yoke before curing are magnetized, so that the disordered ferromagnetic conductive particles in the electromagnetic shielding strips form N poles and S poles and then attract each other and are oriented. The rear end face of the upper magnetic yoke is tightly fitted with the front end face of the connecting magnetic yoke, and the height adjustment component is used to control the up and down movement, which is used to adjust the distance between the upper magnetic yoke and the lower magnetic yoke according to the requirements of uniform orientation and finalization of electromagnetic shielding strips of different specifications and sizes to be magnetized, and the lower magnetic yoke is integrally fixed to the connecting magnetic yoke.

[0009] The upper and lower ends of the conductive coil are connected in parallel with a bridge rectifier, and then connected in series with an ammeter. The input end of the bridge rectifier is electrically connected to a transformer, and a resistor and a capacitor are connected in series between the transformer and the main circuit for filtering and straightening. A thyristor control switch is also connected in parallel outside the resistor and capacitor for voltage regulation and current limiting, so that the wire coil obtains the required current value.

[0010] The height adjustment assembly is arranged above the upper yoke, and includes a positioning frame, a guide rod and guide sleeve assembly, a screw and sleeve assembly, and a pitch adjusting plate movably connected to the lower end of the screw. The guide rod and guide sleeve assemblies are arranged on both sides of the positioning frame, and the sleeve is fixed to the middle of the positioning frame. The screw and the sleeve are arranged vertically after being screwed together, and the lower end of the screw is movably connected to the pitch adjusting plate. The pitch adjusting plate is fixed to the upper end surface of the upper yoke, and the pitch adjusting plate and the upper yoke are driven to move up and down for pitch adjustment under the rotation cooperation of the screw and sleeve. A locking frame, a U-shaped hole bracket and a locking bolt are arranged between the rear end of the upper yoke and the support frame to ensure that the upper yoke fits tightly with the connecting yoke and ensure stable magnetic flux conduction.

[0011] Furthermore, after being magnetized by the magnetic field generated by the semi-enclosed magnetic yoke, the cross section of the electromagnetic shielding sealing strip is nearly "△" or nearly "∩" shaped.

[0012] Furthermore, a dust cover is provided above the positioning frame for isolating dust.

[0013] Furthermore, dustproof plates are overlapped at the rear ends of the upper magnetic yoke and the lower magnetic yoke.

[0014] Furthermore, a foot pad is provided at the lower end of the lower magnetic yoke to support and position the magnetic forming equipment.

[0015] Furthermore, an exhaust fan is provided on one side of the chassis, and air is taken in from an air inlet on the other side of the chassis, so that the heat generated by the conductive coil in the chassis is extracted with the wind, thereby cooling the conductive coil.

[0016] The beneficial effects of the present invention are:

[0017] 1. The magnetic forming equipment for preparing electromagnetic shielding sealing strips can control the magnetic field flux intensity by means of current size to pull ferromagnetic conductive particles;

[0018] 2. After adjusting the current parameters and the yoke spacing parameters, a linear regression model is used for mathematical modeling and fitting after multiple sets of sampling training, so that the electrical control parameters of the corresponding size parameters of the electromagnetic shielding strips to be magnetized and oriented uniformly can be quickly obtained;

[0019] 3. According to the magnetic strength generated by the current intensity, an electromagnetic shielding sealing strip with a cross section that is nearly "△" or nearly "∩" oriented is obtained, which has wide applicability;

[0020] 4. It can be quickly shaped online, which is convenient for the conveyor belt to continuously supply the dispensing-molded electromagnetic shielding strips for magnetization orientation, and has high production efficiency;

[0021] 5. The initial shape and size of the electromagnetic shielding strip formed by dispensing are very limited and have excellent universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0023] Figure 1 This is a schematic structural diagram of a magnetic forming device for preparing an electromagnetic shielding sealing strip in this embodiment;

[0024] Figure 2 An exploded view of the magnetic forming device described in this embodiment;

[0025] Figure 3 is a three-dimensional diagram of the magnetic forming device described in this embodiment;

[0026] Figure 4 It is a rear side view of the magnetic forming device described in this embodiment;

[0027] Figure 5 It is a left side view of the magnetic forming device described in this embodiment;

[0028] Figure 6 It is a schematic diagram of the electromagnetic shielding sealing strip of this embodiment in an initial state, in a nearly “△”-shaped posture, and in a nearly “∩”-shaped posture;

[0029] Figure 7 This is a schematic diagram of the master control circuit of the electric control cabinet described in this embodiment;

[0030] Figure 8 This is the electrical control schematic diagram of the exhaust fan control circuit and PLC controller described in this embodiment;

[0031] Fig. 9 This is the electrical control schematic diagram of the touch screen, transformer and A / D converter described in this embodiment;

[0032] Fig.10 A photo of the initial state of the electromagnetic shielding sealing strip described in this embodiment;

[0033] Fig.11 This is a photo of the electromagnetic shielding sealing strip described in this embodiment in a nearly “∩”-shaped posture;

[0034] Fig.12 This is a photo of the electromagnetic shielding sealing strip described in this embodiment in a nearly “△” shape;

[0035] Fig.13 It is a surface diagram fitted with data of magnetic force affected by current and distance changes;

[0036] Fig.14 This is the residual analysis diagram of the magnetic force based on the regression typing fitting process;

[0037] Fig.15 It is a scatter plot of the data of magnetic force affected by current and distance;

[0038] Fig.16 It is a fitting curve diagram of current I and aspect ratio η under the working condition that the upper magnetic field spacing is 90 mm;

[0039] Fig.17 It is a fitting curve diagram of current I and aspect ratio η under the working condition that the upper magnetic field spacing is 120 mm;

[0040] Fig.18 It is a fitting curve diagram of current I and aspect ratio η under the working condition that the upper magnetic field spacing is 150mm;

[0041] Among them, 1-electric control cabinet, 2-alarm indicator light, 3-chassis, 4-dust cover, 5-air inlet, 6-front foot pad, 7-lower yoke, 8-upper yoke, 9-positioning frame, 10-guide rod and guide sleeve assembly, 11-screw and screw sleeve assembly, 12-lower half of the conductive coil, 13-upper half of the conductive coil, 14-exhaust fan, 15-middle section of the conductive coil, 16-adjustment plate, 17-support frame, 18-rear foot pad, 19-dust plate, 20-locking bracket, 21-connecting yoke, 22-locking bolt, 23-locking frame, 24-electromagnetic shielding sealing strip in the initial state, 25-electromagnetic shielding sealing strip in a nearly "∩" shape, 26-electromagnetic shielding sealing strip in a nearly "△" shape, 27-ferromagnetic conductive particles. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0043] Example:

[0044] See also Figure 1-9 This embodiment proposes a magnetic forming device for preparing an electromagnetic shielding sealing strip, including an electric control cabinet 1, a chassis 3, a semi-enclosed magnetic yoke, a conductive coil and a height adjustment component.

[0045] The electric control cabinet 1 is provided with a bridge rectifier, a transformer, a Weilun touch screen, a ZW1619-S ammeter, a thyristor AP01, an A / D converter, and a PLC controller based on the Omron CP1H-XA40DR-A model, which are used to conduct direct current to the conductive coil, control the power supply current of the conductive coil, and provide fault alarm reminders.

[0046] An exhaust fan 14 is provided on one side of the chassis 3, and air is taken in from the air inlet 5 on the other side of the chassis 3, and the heat generated by the conductive coil in the chassis 3 is extracted with the wind to cool the conductive coil. The chassis 3 half covers the semi-enclosed magnetic yoke, and the semi-enclosed magnetic yoke is nearly C-shaped as a whole, including a horizontally arranged upper magnetic yoke 8, a lower magnetic yoke 7 and a connecting magnetic yoke 21 arranged vertically at the rear end, the rear end of the upper magnetic yoke 8 surrounds the upper half 13 of the conductive coil, the rear end of the lower magnetic yoke 7 surrounds the lower half 12 of the conductive coil, and the middle section of the connecting magnetic yoke 21 surrounds the middle section 15 of the conductive coil, so that the conductive coil after power is turned on will be a nearly C-shaped magnetic yoke to generate a magnetic field, and the direction of the magnetic flux line is uniformly vertically conducted from the N pole of the lower magnetic yoke 7 to the S pole of the upper magnetic yoke 8, so that the material before curing on the feeding conveyor belt between the upper magnetic yoke 8 and the lower magnetic yoke 7 The electromagnetic shielding strip is magnetized so that the disordered ferromagnetic conductive particles 27 in the electromagnetic shielding strip form N poles and S poles and then attract each other and are oriented. Even two adjacent magnetized ferromagnetic conductive particles 27 are attracted and connected with each other at the head and tail to form a fully enclosed shielding structure that is internally connected to each other. The rear end face of the upper yoke 8 fits tightly with the front end face of the connecting yoke 21, and is controlled to rise and fall by a height adjustment component. It is used to adjust the distance between the upper yoke 8 and the lower yoke 7 according to the requirements of uniform orientation and finalization of electromagnetic shielding strips of different specifications and sizes to be magnetized. The rear ends of the upper yoke 8 and the lower yoke 7 are also overlapped with dustproof plates 19. The lower yoke 7 is integrally fixed to the connecting yoke 21. The lower end of the lower yoke 7 is also provided with foot pads, including front foot pads 6 and rear foot pads 18, so as to support and position the magnetic forming equipment.

[0047] See also Figure 7The upper and lower electrical ends of the conductive coil are connected in parallel with a bridge rectifier, and then connected in series with a ZW1619-S ammeter. The input end of the bridge rectifier is electrically connected to the transformer, and a resistor R01 and a capacitor C01 are connected in series between the transformer and the main circuit for filtering and straightening. Control switches V01 and V02 of thyristor AP01 are also connected in parallel outside the resistor R01 and the capacitor C01 for voltage regulation so that the conductor coil obtains the required current value.

[0048] The height adjustment assembly is arranged above the upper yoke 8, and includes a positioning frame 9, a guide rod and guide sleeve assembly 10, a screw and sleeve assembly 11, and an adjustable distance plate movably connected to the lower end of the screw. A dust cover 4 is also arranged above the positioning frame 9 for dust isolation. The guide rod and guide sleeve assembly 10 are arranged on both sides of the positioning frame 9, and the sleeve is fixed to the middle of the positioning frame 9. The screw and the sleeve are arranged vertically after being screwed together. The lower end of the screw is movably connected to the adjustable distance plate. The adjustable distance plate is fixed to the upper end surface of the upper yoke 8. The screw and the sleeve rotate to drive the adjustable distance plate and the upper yoke 8 to move up and down for distance adjustment. A locking frame 23, a U-shaped hole bracket and a locking bolt 22 are arranged between the rear end of the upper yoke 8 and the support frame 17 to ensure that the upper yoke 8 is tightly fitted with the connecting yoke 21 to ensure stable magnetic flux conduction.

[0049] In particular, see Figure 7 The working principle of the main circuit in the electric control cabinet is as follows: the primary side of the main transformer T1 in the figure is composed of the circuit breaker QF01, the thyristor controlled switches V01 and V02 to form the AC voltage regulation circuit of the main circuit, and the secondary side of T1 is composed of the bridge rectifier circuit, the shunt RS01, the three sections of the load conductive coil, and the freewheeling tube V03 to form a full-wave bridge rectifier main circuit.

[0050] The trigger signal of the thyristor trigger circuit is generated by AP01. The line No. 37 (pin 15 of AP01) is connected to the analog output port, which provides analog potential to adjust the phase shift angle of its output pulse (the higher the potential of pin 15, the smaller the current), so as to realize the voltage regulation of the primary side of the transformer.

[0051] In particular, the power supply of AP01 is provided by the power transformer T2.

[0052] See also Figure 7 , 8and 9. After the digital signal is input into the pre-selected value by the touch screen, the PLC channel sends the corresponding potential from the output module to the 15th foot of AP01. When the "Start" button is pressed, the signal is extracted to the PA01 digital ammeter through the shunt (30:75mv). The digital ammeter has a 0-5V analog output. The current is measured through the corresponding channel of the A / D conversion module of the PLC and sent to the touch screen for display. The measured value is compared with the pre-selected value. When the displayed value is higher or lower than the pre-selected value, the PLC automatic tracking program is used to make corresponding adjustments until the two values ​​are equal or close, thereby stabilizing the current value of the wire coil.

[0053] Since the three groups of coils in the magnetic forming equipment are connected in series, the magnetic field generated by the series coils is affected by the shape of the magnetic yoke. Most of the magnetic field is guided by the magnetic yoke and passes through the C-shaped yoke opening to form a loop upward or downward. The intensity of magnetization changes with the change of the distance of the C-shaped opening. Under the same current parameters, the larger the distance, the smaller the magnetic field; similarly, under the same distance parameters, the larger the current, the larger the magnetic field. Therefore, for this embodiment, we use multi-point sampling, current variables, distance variables and other data parameters to draw a fitting curve based on the linear regression model of the Minitab data analysis tool (see Figure 13-15 ).

[0054] Since the C-shaped yoke structure used in this equipment is not integrally connected, uncertainty is inevitable in the electromagnetism process. Therefore, it is necessary to conduct partial sampling for the distance parameters, including 90mm, 100mm, 110mm, 120mm, 130mm, 140mm and 150mm distance sampling points. When only the current variable is changed, the linear regression model based on the Minitab data analysis tool is used to obtain the curve parameters to determine whether the relationship between the magnetic force (unit: Gauss, Gs) and the current (unit: ampere, A) has a linear relationship. See the attached Fig.14 and 15 Based on the Minitab data analysis tool, the standard deviation analysis of the sampling data is performed, and the sampling data is compared and summarized with the mean to obtain the standardized residual curve of the sampling data to see whether there is a traceable linear relationship. Then, a suitable polynomial model is selected to fit the sampling data, and finally the current-magnetic force fitting curve is obtained by changing the current variable while keeping the distance parameter unchanged. Fig.15 It can be seen that the fitting curve error of current and magnetic force is extremely small, and current and magnetic force have a completely linear relationship.

[0055] It is worth mentioning that, due to the stable working condition of the magnetic forming equipment, the distance parameters usually used are 90mm, 120mm and 150mm to meet the magnetization requirements of the electromagnetic shielding sealing strip fed on the conveyor belt. Therefore, this empirical formula can be further refined into three empirical formulas for three distances with a single variable (current I) retained:

[0056] η(%)=0.6621+0.1118*I-0.005828*I^2+0.000103*I^3; (ⅰ)

[0057] η(%)=0.7261+0.07943*I-0.003151*I^2+0.000045*I^3; (ⅱ)

[0058] η(%)=0.7085+0.07765*I-0.003013*I^2+0.000045*I^3; (ⅲ)

[0059] Wherein, η(%)-the aspect ratio of the electromagnetic shielding sealing strip after magnetization forming;

[0060] I-current, unit: ampere A;

[0061] Formula I - Under the working condition that the distance between the upper yoke and the lower yoke of the magnetic forming equipment is 90 mm, the aspect ratio η (%) obtained by changing the current I parameter is as follows: Fig.16 ;

[0062] Formula II - Under the working condition that the distance between the upper yoke and the lower yoke of the magnetic forming equipment is 120 mm, the aspect ratio η (%) obtained by changing the current I parameter is as follows: Fig.17 ;

[0063] Formula III - Under the working condition that the distance between the upper yoke and the lower yoke of the magnetic forming equipment is 150mm, the aspect ratio η (%) obtained by changing the current I parameter is as follows: Fig.18 .

[0064] As a further implementation plan, based on the above data modeling and analysis, we stipulate that the cross-section of the electromagnetic shielding sealing strip is nearly "△" or nearly "∩" after being magnetized and formed in the magnetic field generated by the semi-closed magnetic yoke, where the nearly "△"-shaped judgment range is the electromagnetic shielding sealing strip after magnetization with an aspect ratio η (%) greater than 1.25, and the nearly "∩"-shaped judgment range is the electromagnetic shielding sealing strip after magnetization with an aspect ratio η (%) of 1-1.25.

[0065] Based on the above regulations for electromagnetic shielding strips that are close to "△" or "∩" type, we enter the empirical formulas i, ii and iii obtained by fitting the curve into the PLC programming code. According to the empirical formulas, we independently adopt the appropriate distance between the upper and lower yokes, as well as the current parameters to obtain electromagnetic shielding strips that are close to "△" or "∩" type. It is easy to adjust and has a wide applicability.

[0066] The above describes in detail the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes, modifications, substitutions and variations can be made within the knowledge scope of ordinary technicians in the field without departing from the spirit of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A magnetic forming device for preparing an electromagnetic shielding sealing strip, characterized in that: It includes an electric control cabinet, a chassis, a semi-enclosed magnetic yoke, a conductive coil and a height adjustment component. The electric control cabinet is equipped with a bridge rectifier, a transformer, a touch screen, an ammeter, a thyristor, and a PLC controller, which are used to conduct direct current to the conductive coil and control the power supply current of the conductive coil and the fault alarm reminder. The chassis half covers the semi-enclosed magnetic yoke, and the semi-enclosed magnetic yoke is nearly C-shaped as a whole, including a horizontally arranged upper magnetic yoke, a lower magnetic yoke and a connecting magnetic yoke arranged vertically at the rear end. The rear end of the upper magnetic yoke surrounds the upper half of the conductive coil, the rear end of the lower magnetic yoke surrounds the lower half of the conductive coil, and the middle section of the connecting magnetic yoke surrounds the middle section of the conductive coil, so that the conductive coil after power is turned on will generate a magnetic field in a nearly C-shaped magnetic yoke, and the direction of the magnetic flux line is uniformly vertically transmitted from the N pole of the lower magnetic yoke to the S pole of the upper magnetic yoke, and the electromagnetic shielding strip on the feeding conveyor belt between the upper and lower magnetic yokes before curing is magnetized, so that the disordered ferromagnetic conductive particles in the electromagnetic shielding strip form N poles and S poles, and then the opposite poles attract each other and are oriented, the rear end face of the upper magnetic yoke is tightly fitted with the front end face of the connecting magnetic yoke, and the height adjustment component controls the up and down movement, and the lower magnetic yoke is integrally fixed to the connecting magnetic yoke. The height adjustment assembly is arranged above the upper magnetic yoke, and comprises a positioning frame, a guide rod and guide sleeve assembly, a screw rod and screw sleeve assembly, and a distance adjustment plate movably connected to the lower end of the screw rod.

2. The magnetic forming equipment for preparing electromagnetic shielding sealing strip according to claim 1, characterized in that: The upper and lower electrical ends of the conductive coil are connected in parallel with a bridge rectifier, and then connected in series with an ammeter. The input end of the bridge rectifier is electrically connected to a transformer, and a resistor and a capacitor are connected in series between the transformer and the main circuit for filtering and straightening, and a thyristor control switch is also connected in parallel outside the resistor and capacitor.

3. The magnetic forming equipment for preparing electromagnetic shielding sealing strip according to claim 1, characterized in that: The guide rod and guide sleeve assemblies are arranged on both sides of the positioning frame, the screw sleeve is fixed in the middle of the positioning frame, the screw rod and the screw sleeve are screwed together and arranged vertically, the lower end of the screw rod is movably connected to the distance adjusting plate, and the distance adjusting plate is fixedly connected to the upper end surface of the upper magnetic yoke.

4. The magnetic forming equipment for preparing electromagnetic shielding sealing strip according to claim 1, characterized in that: A locking frame, a U-shaped hole bracket and a locking bolt are arranged between the rear end of the upper magnetic yoke and the supporting frame, so that the upper magnetic yoke and the connecting magnetic yoke are tightly fitted.

5. The magnetic forming equipment for preparing electromagnetic shielding sealing strip according to claim 1, characterized in that: After being magnetized by the magnetic field generated by the semi-enclosed magnetic yoke, the cross section of the electromagnetic shielding sealing strip is nearly "△" or nearly "∩" shaped.

6. The magnetic forming equipment for preparing electromagnetic shielding sealing strip according to claim 1, characterized in that: A dust cover is also arranged above the positioning frame.

7. The magnetic forming equipment for preparing electromagnetic shielding sealing strip according to claim 1, characterized in that: Dust-proof plates are overlapped at the rear ends of the upper magnetic yoke and the lower magnetic yoke, and a foot pad is also arranged at the lower end of the lower magnetic yoke.

8. The magnetic forming equipment for preparing electromagnetic shielding sealing strip according to claim 1, characterized in that: An exhaust fan is arranged on one side of the chassis, and air is taken in from an air inlet on the other side of the chassis.

9. A method for magnetizing and forming an electromagnetic shielding sealing strip, according to the magnetic forming device for preparing an electromagnetic shielding sealing strip according to any one of claims 1 to 8, using a C-type yoke spacing of 90 mm, 120 mm or 150 mm, and obtaining the required aspect ratio η (%) of the magnetized electromagnetic shielding sealing strip according to the following empirical formula: η(%)=0.6621+0.1118*I-0.005828*I^2+0.000103*I^3; (ⅰ) η(%)=0.7261+0.07943*I-0.003151*I^2+0.000045*I^3; (ⅱ) η(%)=0.7085+0.07765*I-0.003013*I^2+0.000045*I^3;(iii) Wherein, η(%)-the aspect ratio of the electromagnetic shielding sealing strip after magnetization forming; I-current, unit: ampere A; Formula ⅰ-the aspect ratio η (%) obtained by changing the current I parameter under the working condition that the distance between the upper yoke and the lower yoke of the magnetic forming equipment is 90 mm; Formula ii - The aspect ratio η (%) obtained by changing the current I parameter under the working condition that the distance between the upper yoke and the lower yoke of the magnetic forming equipment is 120 mm; Formula III - Under the working condition that the distance between the upper yoke and the lower yoke of the magnetic forming equipment is 150 mm, the aspect ratio η (%) is obtained by changing the current I parameter.

10. The method for magnetizing and forming an electromagnetic shielding sealing strip according to claim 9, characterized in that: After the electromagnetic shielding sealing strip is magnetized and formed in the magnetic field generated by the semi-closed magnetic yoke, the electromagnetic shielding sealing strip with an aspect ratio η (%) greater than 1.25 is judged to have a cross-section that is nearly "△" shaped, and the electromagnetic shielding sealing strip with an aspect ratio η (%) of 1-1.25 is judged to have a cross-section that is nearly "∩" shaped.

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