WO2022206018A1

WO2022206018A1 - Magnetic forming device for preparing electromagnetic shielding sealing strip

Info

Publication number: WO2022206018A1
Application number: PCT/CN2021/137190
Authority: WO
Inventors: 王华利; 陆红华; 张勇; 郭本祝; 李闵杰; 孙金龙
Original assignee: 沃奇汽车技术(苏州)有限公司
Priority date: 2021-03-30
Filing date: 2021-12-10
Publication date: 2022-10-06
Also published as: MX2023008438A; DE212021000490U1; CN112885559A

Abstract

Disclosed in the present invention is a magnetic forming device for preparing an electromagnetic shielding sealing strip, comprising an electric control cabinet, a case, a semi-closed yoke, a conductive coil, and a height adjustment assembly. A bridge rectifier, a transformer, a touch screen, an ammeter, a silicon controlled rectifier, and a PLC controller are provided in the electric control cabinet; the case semi-covers the semi-closed yoke; the whole semi-closed yoke is approximately C-shaped, and comprises an upper yoke, a lower yoke, and a connecting yoke that are horizontally arranged; the height adjustment assembly comprises a positioning frame, a guide rod/guide sleeve assembly, a screw rod/screw sleeve assembly, and a distance adjustment plate movably connected to the lower end of a screw rod. The magnetic forming device can pull ferromagnetic conductive particles by controlling the magnetic flux intensity of a magnetic field by means of the current size; an electric control parameter can be rapidly obtained by performing mathematical modeling and fitting by means of a linear regression model after regulating a current parameter and a yoke distance parameter and performing multiple sets of sampling training; and an electromagnetic shielding sealing strip having an approximate "Δ" shape or approximate "n" shape is obtained according to the change in current intensity, and has wide applicability.

Description

A kind of magnetic forming equipment for preparing electromagnetic shielding sealing strip

technical field

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

Background technique

Electromagnetic shielding sealing strips or electromagnetic shielding gaskets, as electronic product sealing materials and electromagnetic shielding materials, have been widely recognized by the market and are mainly used in automotive, radar, power amplifier, military, communication base stations, high-frequency signal shielding and other fields. The sealing strip is mostly made of silicone material, and the sealing strip is doped with tiny particles or flake-shaped ferromagnetic conductive particles, and the magnetic field magnetization is used to make the ferromagnetic conductive particles obtain a magnetization effect, causing all ferromagnetic conductive particles to produce weak Magnetic poles, and then two adjacent ferromagnetic conductive particles attract each other with opposite poles. All ferromagnetic conductive particles are positioned according to the direction of the magnetic field line and solidified and then shaped. After being applied to electronic products, the traditional electromagnetic sealing strip can be passed through the gap. The electromagnetic signal is 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 special production and preparation equipment, so the application prospect is broad.

For this reason, as the production of new electromagnetic shielding sealing strips, it is necessary to make the ferromagnetic conductive particles magnetize and orientate uniformly in the magnetic field before forming, and such electromagnetic shielding sealing strips are shaped immediately after being magnetized. The material of the sealing strip is preliminarily shaped through the magnetization process, so it is necessary to design an adsorption device that can assist the preliminary shaping of the electromagnetic shielding sealing strip.

SUMMARY OF THE INVENTION

The purpose of the invention is to make the ferromagnetic conductive particles in the electromagnetic shielding strip formed by dispensing can be uniformly oriented after magnetization, fully shield the electromagnetic signal passing through the gap, and improve the electromagnetic interference problem of the existing electromagnetic shielding strip. Design an adsorption device that can assist the electromagnetic shielding sealing strip in preliminary shaping.

The technical solutions adopted to solve the above problems are:

A magnetic forming equipment for preparing electromagnetic shielding sealing strips comprises an electric control cabinet, a chassis, a semi-closed magnetic yoke, a conductive coil and a height adjustment component.

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

The case half covers the semi-closed magnetic yoke, and the semi-closed magnetic yoke is nearly C-shaped as a whole, including an upper magnetic yoke arranged horizontally, 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 yoke surrounds the middle section of the conductive coil, so that the conductive coil after energization will be nearly C-shaped The magnetic yoke generates a magnetic field, and the direction of the magnetic field line is uniformly conducted vertically from the N pole of the lower yoke to the S pole of the upper yoke. The electromagnetic shielding strip is magnetized, so that the disordered ferromagnetic conductive particles in the electromagnetic shielding strip form N pole and S pole and then opposite poles attract and orientate, and the rear surface of the upper magnetic yoke is closely attached to the front surface of the connecting magnetic yoke , and is controlled up and down by the height adjustment component, which is used to adjust the distance between the upper yoke and the lower yoke according to the requirements of the electromagnetic shielding strips of different sizes to be magnetized, oriented and shaped. The lower yoke and the connecting yoke united,

The upper end and the lower end of the conductive coil are connected in parallel with the bridge rectifier, and then connected in series with the ammeter. It is straightened by filtering, and a thyristor control switch is connected in parallel outside the resistor and capacitor, which is used for voltage regulation and current limiting, so that the wire coil can obtain the required current value,

The height adjustment assembly is arranged above the upper magnetic yoke, and includes a positioning frame, a guide rod guide sleeve assembly, a screw thread sleeve assembly, and a distance adjustment plate movably connected to the lower end of the screw rod. The guide rod guide sleeve assembly is disposed on two sides of the positioning frame. On the side, 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 with the distance adjustment plate, the distance adjustment plate is fixedly connected to the upper end face of the upper magnetic yoke, and the distance adjustment plate is fixed on the upper end face of the upper magnetic yoke. The sleeve rotates and cooperates to drive the distance-adjusting plate and the upper magnetic yoke to move up and down to adjust the distance. 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 support frame to ensure that the upper magnetic yoke is connected to the support frame. The connecting yoke is tightly fitted to ensure stable magnetic flux conduction.

Further, after the electromagnetic shielding sealing strip is magnetized by the magnetic field generated by the semi-closed magnetic yoke, the cross section is approximately "△" or approximately "∩" shape.

Further, a dust cover is also provided above the positioning frame for dust isolation.

Further, the rear ends of the upper magnetic yoke and the lower magnetic yoke are also provided with dustproof plates overlapping.

Further, the lower end of the lower magnetic yoke is also provided with a foot pad to support and position the magnetic forming equipment.

Further, an exhaust fan is arranged on one side of the case, and the air is taken in from the air inlet on the other side of the case, and the heat generated by the conductive coil in the case is drawn out with the wind to cool the conductive coil.

The beneficial effects of the present invention are:

1. The magnetic forming equipment for preparing electromagnetic shielding sealing strips can pull ferromagnetic conductive particles by controlling the magnetic flux intensity of the magnetic field by means of the magnitude of the current;

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

3. And according to the magnetic force generated by the current intensity, the electromagnetic shielding sealing strip with a cross-section of nearly "△" or nearly "∩" type orientation is obtained, which has wide applicability;

4. And it can be quickly shaped online, which is convenient for the conveyor belt to continuously supply the electromagnetic shielding strip formed by dispensing for magnetization orientation, and the production efficiency is high;

5. The initial shape and size of the electromagnetic shielding strip formed by dispensing are extremely limited, and the universality is excellent.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments.

1 is a schematic structural diagram of a magnetic forming device for preparing an electromagnetic shielding sealing strip according to the present embodiment;

FIG. 2 is an exploded view of the magnetic forming equipment according to the present embodiment;

3 is a perspective view of the magnetic forming equipment according to this embodiment;

FIG. 4 is a rear side view of the magnetic forming apparatus according to this embodiment;

FIG. 5 is a left side view of the magnetic forming apparatus according to this embodiment;

FIG. 6 is a schematic diagram of the initial state of the electromagnetic shielding sealing strip according to the present embodiment, in a nearly "△" shape attitude, and a near "∩" shape attitude;

FIG. 7 is a schematic diagram of the master control circuit of the electric control cabinet according to this embodiment;

8 is a schematic diagram of the electrical control of the exhaust fan control circuit and the PLC controller described in this embodiment;

9 is a schematic diagram of the electrical control of the touch screen, the transformer and the A/D converter according to this embodiment;

FIG. 10 is a photo of the initial state of the electromagnetic shielding sealing strip described in this embodiment;

Fig. 11 is a photo of the electromagnetic shielding sealing strip according to this embodiment in a nearly "∩" shape;

Fig. 12 is a photo of the electromagnetic shielding sealing strip of the present embodiment in a nearly "△" shape;

Fig. 13 is the data fitting surface diagram of the change of magnetic force by current and distance;

Fig. 14 is a residual analysis diagram of the magnetic force-based regression typing fitting process;

Fig. 15 is a data scatter plot of the change of magnetic force by current and distance;

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

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

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

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 guide sleeve assembly, 11-screw screw sleeve assembly, 12-conductive coil lower half, 13-conductive coil upper half, 14-exhaust fan, 15-conductive coil middle section, 16-adjustment plate, 17 -Support frame, 18- Rear foot pad, 19- Dustproof plate, 20- Locking bracket, 21- Connecting yoke, 22- Locking bolt, 23- Locking frame, 24- Electromagnetic shielding sealing strip in initial state, 25 -Electromagnetic shielding sealing strip with a nearly "∩" shape, 26- Electromagnetic shielding sealing strip with a near "△" shape, 27- Ferromagnetic conductive particles.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Example:

Referring to FIGS. 1-9 , this embodiment provides a magnetic forming device for preparing electromagnetic shielding sealing strips, including an electric control cabinet 1 , a chassis 3 , a semi-enclosed magnetic yoke, a conductive coil and a height adjustment component.

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. It is used to conduct DC power to the conductive coil, and control the power supply current of the conductive coil and the fault alarm reminder.

One side of the case 3 is provided with an exhaust fan 14, and the air is drawn from the air inlet 5 on the other side of the case 3, and the heat generated by the conductive coil in the case 3 is drawn out with the wind, so that the conductive coil is cooled down, and the case 3 is halfway. Covering the semi-closed magnetic yoke, the semi-closed magnetic yoke is nearly C-shaped as a whole, including a horizontally arranged upper magnetic yoke 8, a lower magnetic yoke 7 and a vertically arranged connecting magnetic yoke 21 at the rear end. The rear end of the magnetic yoke 8 surrounds the upper half section 13 of the conductive coil, the rear end of the lower magnetic yoke 7 surrounds the lower half section 12 of the conductive coil, and the middle section of the connecting yoke 21 surrounds the middle section 15 of the conductive coil, so that the conductive coil after electrification The nearly C-shaped yoke generates a magnetic field, and the direction of the magnetic field line is uniformly conducted vertically from the N pole of the lower yoke 7 to the S pole of the upper yoke 8, and the gap between the upper yoke 8 and the lower yoke 7 The electromagnetic shielding strip before solidification on the feeding conveyor belt is magnetized, so that the disordered ferromagnetic conductive particles 27 in the electromagnetic shielding strip form N pole, S pole and opposite poles attract and orientate, even two adjacent ones. The magnetized ferromagnetic conductive particles 27 are attached to each other by end-to-end adsorption to form a fully enclosed shielding structure that is connected to each other inside. Lifting up and down is used to adjust the spacing between the upper yoke 8 and the lower yoke 7 according to the requirements of the electromagnetic shielding strips of different sizes to be magnetized, oriented and shaped. The rear ends of the upper yoke 8 and the lower yoke 7 are also A dust-proof plate 19 is provided overlappingly, the lower magnetic yoke 7 is integrally connected with the connecting magnetic yoke 21, and the lower end of the lower magnetic yoke 7 is also provided with a foot pad, including the front foot pad 6 and the rear foot pad 18, so as to support positioning Live magnetic forming equipment.

Referring to Figure 7, the upper and lower ends of the conductive coil are connected in parallel with the bridge rectifier, and then connected in series with the ZW1619-S ammeter, and the input end of the bridge rectifier is electrically connected to the transformer, and the transformer and the main circuit are A resistor R01 and a capacitor C01 are connected in series between them for filtering and straightening, and the control switches V01 and V02 of the thyristor AP01 are connected in parallel on the outside of the resistor R01 and the capacitor C01 for voltage regulation, so that the wire coil can obtain the required current value.

The height adjustment assembly is arranged above the upper magnetic yoke 8, and includes a positioning frame 9, a guide rod guide sleeve assembly 10, a screw thread sleeve assembly 11, and a distance adjustment plate movably connected to the lower end of the screw rod. The positioning frame 9 is also provided above. There is a dust cover 4 for dust isolation, the guide rod guide sleeve assembly 10 is arranged on both sides of the positioning frame 9, the screw sleeve is fixed in the middle of the positioning frame 9, and the screw rod and the screw sleeve are screwed and arranged vertically. The lower end of the screw is movably connected with the distance-adjusting plate. The distance-adjusting plate is fixedly connected to the upper end face of the upper magnetic yoke 8. Under the rotation of the screw sleeve, the distance-adjusting plate and the upper magnetic yoke 8 are moved up and down to adjust the distance. The upper magnetic yoke 8. A locking frame 23, a U-shaped hole bracket and a locking bolt 22 are arranged between the rear end and the support frame 17 to ensure that the upper magnetic yoke 8 is closely fitted with the connecting magnetic yoke 21 to ensure stable magnetic flux conduction.

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

The trigger signal of the thyristor trigger circuit is generated by AP01, and the line number 37 (pin 15 of AP01) is connected to the analog output port, and the analog output port provides analog potential to adjust the phase shift angle of its output pulse (15 The higher the pin potential, the smaller the current). To achieve voltage regulation on the primary side of the transformer.

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

Referring to Figures 7, 8 and 9, after the digital signal is input to the preselected value from the touch screen, the PLC channel sends the corresponding potential from the output module to the 15 pin of AP01, and when the "Start" button is pressed, the signal is extracted through the shunt (30:75mv) To the PA01 digital ammeter, the digital ammeter has a 0-5V analog output, and 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 When the value is higher or lower than the preselected value, the corresponding adjustment is re-adjusted by the PLC automatic tracking program until the two values are equal or close, so as to stabilize the current value of the wire coil.

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

Since the C-type yoke structure used by this equipment is not integrally connected, uncertainty will inevitably occur in the process of electromagnetization. For this reason, it is necessary to conduct partial sampling for distance parameters, including 90mm, 100mm, 110mm, 120mm, 130mm, 140mm and 150mm In the case of only changing the current variable, the curve parameters are obtained based on the linear regression model of the Minitab data analysis tool to determine whether the relationship between the magnetic force (unit: Gauss, Gs) and the current (unit: Ampere, A) is linear. relationship, referring to Figures 14 and 15, based on the Minitab data analysis tool, the standard deviation analysis of the sampled data is carried out, and then the sampled data is compared and summarized with the mean, and the standardized residual curve of the sampled data is obtained. Whether there is a followable linear relationship, Then select a suitable polynomial model to fit and process the sampled data, and finally obtain the current-magnetic force fitting curve obtained by changing the current variable without changing the distance parameter. See Figure 15. It can be seen that the error of the fitting curve between the current and the magnetic force is extremely small. Electric current and magnetic force have a completely linear relationship.

It is worth mentioning that due to the stable working conditions of the magnetic forming equipment, the distance parameters usually used are 90mm, 120mm and 150mm to meet the magnetization requirements of the electromagnetic shielding seals fed on the conveyor belt, so this empirical formula can be refined. Converted to three empirical formulas for three distances, retaining a single variable (current I):

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)

Among them, η (%) - the aspect ratio of the electromagnetic shielding sealing strip after magnetization;

I-current, unit: ampere A;

Formula 1 - 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 90mm, see Figure 16;

Formula 2 - 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 120mm, see Figure 17;

Formula ⅲ - 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 150mm, see Figure 18.

As a further embodiment, based on the above data modeling analysis, we stipulate that the electromagnetic shielding sealing strip has a nearly "△" or "∩" cross-section after being magnetized and formed by the magnetic field generated by the semi-closed yoke, wherein the The judging range of the △" type is the magnetized electromagnetic shielding sealing strip with an aspect ratio η(%) greater than 1.25, and the judgment range of the near "∩" type is the electromagnetic shielding sealing strip after the magnetization with an aspect ratio η(%) of 1-1.25.

Based on the above-mentioned regulations on electromagnetic shielding strips of near "△" or near "∩" type, we input the empirical formulas ⅰ, Ⅱ and ⅲ obtained by fitting the curve into the PLC programming code. The "∩" type electromagnetic shielding bar independently adopts the appropriate distance between the upper yoke and the lower yoke, as well as the current parameters, which is easy to adjust and has wide applicability.

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and can also be made within the scope of knowledge possessed by those of ordinary skill in the art without departing from the purpose of the present invention. After various changes, modifications, substitutions and alterations, the scope of the present invention is defined by the appended claims and their equivalents.

Claims

A magnetic forming equipment for preparing electromagnetic shielding sealing strips is characterized in that it comprises an electric control cabinet, a chassis, a semi-closed magnetic yoke, a conductive coil and a height adjustment component,

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

The case half covers the semi-closed magnetic yoke, and the semi-closed magnetic yoke is nearly C-shaped as a whole, including an upper magnetic yoke arranged horizontally, a lower magnetic yoke and a connecting magnetic yoke arranged vertically at the rear end. The rear end of the upper yoke surrounds the upper half of the conductive coil, the rear end of the lower yoke surrounds the lower half of the conductive coil, and the middle section of the connecting yoke surrounds the middle section of the conductive coil, so that the conductive coil after energization will be nearly C-shaped The magnetic yoke generates a magnetic field, and the direction of the magnetic field line is uniformly conducted vertically from the N pole of the lower yoke to the S pole of the upper yoke. The electromagnetic shielding strip is magnetized, so that the disordered ferromagnetic conductive particles in the electromagnetic shielding strip form N pole and S pole and then opposite poles attract and orientate, and the rear surface of the upper magnetic yoke is closely attached to the front surface of the connecting magnetic yoke , and is controlled up and down by the height adjustment component, the lower yoke is integrally connected with the connecting yoke,

The height adjustment assembly is arranged above the upper magnetic yoke, and includes a positioning frame, a guide rod guide sleeve assembly, a screw screw sleeve assembly, and a distance adjustment plate movably connected with the lower end of the screw rod.
The magnetic forming equipment for preparing electromagnetic shielding sealing strips according to claim 1, characterized in that: the upper end of the conductive coil and the lower end of the conductive coil are connected in parallel with the bridge rectifier, and then connected in series with the ammeter, and the bridge rectifier is connected in parallel. The input terminal is electrically connected to the 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 connected in parallel outside the resistor and the capacitor.
The magnetic forming equipment for preparing electromagnetic shielding sealing strips 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, and the screw and the screw sleeve are screwed together. After being connected and matched, it is arranged vertically, and the lower end of the screw rod is movably connected with the distance-adjusting plate, and the distance-adjusting plate is fixedly connected to the upper end face of the upper magnetic yoke.
The magnetic forming equipment for preparing electromagnetic shielding sealing strips according to claim 1, wherein 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 support frame, so that the upper magnetic The yoke is tightly fitted with the connecting yoke.
The magnetic forming equipment for preparing electromagnetic shielding sealing strips according to claim 1, characterized in that: after the electromagnetic shielding sealing strips are magnetized by the magnetic field generated by the semi-closed magnetic yoke, the cross-section is approximately "△" or nearly "∩" "type.
The magnetic forming equipment for preparing electromagnetic shielding sealing strips according to claim 1, wherein a dust cover is further provided above the positioning frame.
The magnetic forming equipment for preparing electromagnetic shielding sealing strips according to claim 1, wherein the rear ends of the upper magnetic yoke and the lower magnetic yoke are also provided with dustproof plates, and the lower end of the lower magnetic yoke is also provided with a dustproof plate. foot pads.
The magnetic forming equipment for preparing electromagnetic shielding sealing strips according to claim 1, characterized in that: an exhaust fan is arranged on one side of the casing, and the air is taken in from an air inlet on the other side of the casing.
A magnetization forming method of electromagnetic shielding sealing strip, characterized in that, according to the magnetic forming equipment for preparing electromagnetic shielding sealing strip according to any one of claims 1-8, a C-shaped magnetic yoke spacing of 90mm, 120mm or 150mm is adopted, according to The following empirical formula is used to obtain the magnetized electromagnetic shielding sealing strip with the required aspect ratio η (%):

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)

Among them, η (%) - the aspect ratio of the electromagnetic shielding sealing strip after magnetization;

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 90mm;

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 120mm;

Formula iii - 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 150mm.
The method for magnetizing the electromagnetic shielding sealing strip according to claim 9, characterized in that: after the electromagnetic shielding sealing strip is magnetized and formed by the magnetic field generated by the semi-closed magnetic yoke, the aspect ratio η(%) is larger than 1.25 after magnetization. The electromagnetic shielding sealing strip is judged to have a nearly "△" section in cross section, and the magnetized electromagnetic shielding sealing strip with an aspect ratio of η(%) of 1-1.25 is judged to have a nearly "∩" section.