Detachable planar magnetic attraction connection positioning device and optimization method

Abstract

The application discloses an optimization method of a detachable plane magnetic attraction connection positioning device, and mainly solves the problems of complicated positioning devices and complicated manufacturing processes in the prior art. The method comprises two detachable components (1, 2) and two magnet groups (3, 4), the two detachable components are both provided with plane structures as upper and lower two fixing surfaces; the two magnet groups are embedded into the two planes respectively according to the polarities attracting each other to realize plane connection and positioning. Different optimization measures are adopted according to different positioning conditions of the two detachable components after being connected: precise positioning is realized by optimizing magnet distribution and magnetization strength; over-recovery after connection is corrected by reducing the number of magnets or reducing magnetization strength; over-twisting after connection is corrected by reducing the distance between the two magnet modules or increasing auxiliary positioning magnets. The application discards the required pins of the existing connection device, has simple structure, low cost and high positioning accuracy, and can be used for various plane connections.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of machinery, and particularly relates to a planar magnetic attraction connection and positioning device which can be used for magnetic connection and accurate alignment and positioning between planar surfaces of multiple electronic devices and various mechanical devices. BACKGROUND

[0002] In the era of rapid iteration of electronic products, two devices or even multiple devices are connected and matched to form a new application terminal, which has become a research and development trend of the new generation of products. The magnetic attraction type connection has been widely used by various companies due to its simple principle and manufacturing advantage, and has great value and broad prospects. For example, the connection between the Surface Pro 8 tablet computer and the keyboard of Microsoft relies on two pins to achieve accurate positioning, and a magnet is used to achieve the attraction of the two; the screen and keyboard of the Surface Book 3 computer are detachable, and the positioning of the screen and keyboard relies on the arc-shaped frames at both ends of the keyboard and the screen to achieve accurate positioning; the positioning of the Mate Paid Pro tablet and keyboard of Huawei relies on the arc-shaped frame of the tablet frame and the arc-shaped pit of the keyboard to achieve rough positioning. However, the above three products do not directly realize the connection and accurate positioning of two planar surfaces, but need to rely on the positioning of pins and pin holes, or rely on the arc-shaped pits and bosses on the connecting parts and the connected parts to achieve accurate positioning. When using one of the devices alone, the pins, pin holes, pits or bosses on the surface of the device are not only unsightly but also have safety hazards. If the connection and positioning of two flat surfaces can be achieved and the pins and pin holes on the surface of the device are removed, the product can be further beautified, the safety can be increased, and the manufacturing cost can be reduced. However, most of the current magnetic attraction devices can only realize the connection between flat surfaces but cannot realize the accurate positioning between planar surfaces.

[0003] In 2016, patent US9426905B2 proposed to realize the connection between a tablet computer and a Bluetooth keyboard by using a magnet group with alternating magnetic poles, which relies on two pins on the keyboard and two pin holes on the tablet, as well as a micro-radian curved surface to realize accurate positioning. In 2020, patent US10671121B2 proposed to realize the connection between a tablet computer and a Bluetooth keyboard by using a magnet group with alternating magnetic poles, which relies on a right-angled boss on the keyboard and a right-angled frame on the tablet to realize accurate positioning. However, they do not realize the direct positioning of two planar surfaces, and the pins, pin holes, micro-radian curved surfaces and bosses on the connection surface not only complicate the manufacturing process, increase the manufacturing cost, but also bring safety hazards.

[0004] Based on the shortcomings of the above products, the present application proposes a low-cost, low-safety-hazard detachable planar magnetic attraction connection and positioning device. SUMMARY

[0005] The present application aims at the deficiencies of the prior art, and provides a detachable plane magnetic attraction connection positioning device and an optimization method, so as to simplify the structure of the plane positioning device and reduce the manufacturing cost while realizing the connection and accurate positioning of two planes.

[0006] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0007] 1. A detachable plane magnetic attraction connection positioning device, comprising two detachable components and two magnet groups, characterized in that:

[0008] The two detachable components are both in a plane structure, serving as upper and lower two fixed planes C and D;

[0009] The two magnet groups are embedded in the planes C and D respectively according to the polarity of mutual attraction, realizing the connection and positioning of the two planes.

[0010] Further, the two detachable components use a material that can conduct magnetism but is not magnetized.

[0011] Further, the array form of the magnets of the two magnet groups is completely the same, each magnet group is composed of two magnet modules, each magnet module includes an odd number of magnets, the two magnet modules are placed separately and embedded in a plane, and the two magnet groups are distributed according to the rule of staggered adjacent magnet polarity and embedded in the planes C and D respectively.

[0012] Further, the length of each magnet module is between 1 / 6 and 1 / 4 of the length of the shorter plane C or D, so as to realize better positioning accuracy.

[0013] 2. An optimization method of a detachable plane magnetic attraction connection positioning device, characterized in that the effect of accurate positioning of the detachable component is achieved by optimizing the number, position and magnetization strength of the magnets in the two magnet groups:

[0014] When displacement is insufficient after the detachable components are connected, the displacement is increased by increasing the number of magnets or increasing the magnetization strength of the magnets;

[0015] When displacement is excessive after the detachable components are connected, the displacement is reduced by reducing the number of magnets or reducing the magnetization strength of the magnets;

[0016] When the twist is excessive after the detachable components are connected, the twist is suppressed by reducing the distance between the two magnet modules or increasing the magnets for auxiliary positioning;

[0017] The magnetic attraction force during connection is adjusted to the expected magnetic attraction force by enlarging or reducing the magnetization strength of the magnets in equal proportion.

[0018] 3. A method for using a detachable planar magnetic attraction connection positioning device, characterized in that two magnet groups are embedded in two devices to be connected respectively according to the mutually attractive polarity and the staggered distribution of adjacent magnet polarities in each magnet group, one of the devices to be connected is placed on a horizontal table, and the other device to be connected is placed above it, and the positioning and connection between the two are realized by the attraction between the magnet groups.

[0019] When separating the devices to be connected, the device to be connected above is pushed horizontally, and the same polarity magnets repel each other to reduce the force required to separate the two.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1. The present application realizes the connection and positioning of two planes by reasonably arranging magnets, simplifies the pins, pin holes and special profile design existing in the previous planar magnetic attraction connection, reduces the structural complexity, simplifies the manufacturing process, and thus reduces the cost.

[0022] 2. The present application optimizes the distribution and magnetization strength of the detachable planar magnetic attraction connection positioning device to match various sizes and shapes of planar connections, and is suitable for various planar connection scenes, and has wide applicability. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural diagram of the detachable planar magnetic attraction connection positioning device of the present application;

[0024] Figure 2 is a side view of Figure 1 ;

[0025] Figure 3 is a recovery displacement nephogram of the upper assembly of Example 1 of the present application in the x and y directions; wherein (a) and (b) correspond to the recovery displacement nephograms of the upper detachable assembly in the x direction and the y direction, respectively;

[0026] Figure 4 is a flowchart of the optimization of the magnet group of the present application;

[0027] Figure 5 is a front view of the separation state of Example 2 of the present application;

[0028] Figure 6 is a recovery displacement nephogram of the assembly of Example 2 of the present application in the x and y directions; wherein (a) and (b) correspond to the recovery displacement nephograms of the upper detachable assembly in the x direction and the y direction, respectively;

[0029] Figure 7The recovery displacement cloud map of the upper assembly of Example 3 of the present application in x and y directions; wherein (a), (b) respectively correspond to the recovery displacement cloud map of the upper detachable assembly in x direction, y direction;

[0030] Figure 8 The structural diagram of Example 4 of the present application;

[0031] Figure 9 The magnetic distribution map of the auxiliary positioning magnet of Example 4 of the present application;

[0032] Figure 10 The recovery displacement of the upper assembly of Example 4 of the present application in x and y directions; wherein (a), (b) respectively correspond to the recovery displacement cloud map of the upper assembly in x direction, y direction. DETAILED DESCRIPTION

[0033] The following further details the design, embodiments and effects of the present application in combination with the accompanying drawings:

[0034] Example 1: Based on the size of the tablet computer, two detachable assemblies with a size of 210x7x6 (mm) are designed to simulate the connection and positioning of the planar magnetic attraction connection positioning device. In order to test the planar positioning effect, the upper assembly is provided with an initial deviation in x and y directions. The magnetic attraction force is required to be controlled within 10-20 N, and the positioning error is required to be controlled within 0.1 mm.

[0035] Referring to Figure 1 and Figure 2 , the present example includes two detachable assemblies 1 and 2, and two magnet groups 3 and 4. Both detachable assemblies adopt a planar structure and use a material that can conduct magnetism but is not magnetized, and are respectively used as the lower fixed surface C of the lower connected device 9 and the upper fixed surface D of the upper connected device 10; the array form of the two magnet groups is exactly the same, each magnet group is composed of two magnet modules 7 and 8, each magnet module includes an odd number of magnets, and the two magnet modules are separately placed and embedded in a plane, and the two magnet groups are distributed according to the rule of adjacent magnetic polarity alternation, and are respectively embedded in the fixed planes C and D. The distance between the two magnet groups and their respective corresponding fixed planes is equal.

[0036] The use of the device is as follows:

[0037] When connecting the two connected devices 9 and 10, the lower connected device 9 is fixed on a horizontal table top, and the upper connected device 10 is placed above the lower connected device 9, and the positioning and connection between the two are achieved by means of the magnetic attraction between the two magnet groups 3 and 4;

[0038] When separating the two connected devices 9 and 10, the upper connected device 10 is horizontally pushed, and the same polarity magnets repel each other to reduce the force required to separate the two.

[0039] In this embodiment, the distance between the first magnet group 3 and the lower fixed surface C and the distance between the second magnet group 4 and the upper fixed surface D are both 0.5 mm, and the distance between the two fixed surfaces C and D is 4 mm. To achieve more accurate positioning, the length of each magnet module is between 1 / 6 and 1 / 4 of the length of the shorter surface of the surfaces C and D, so the size of each magnet in the magnet group is 15x5x3 (mm). The first magnet group 3 is a magnet group with alternating polarities, with black representing the N-pole of the magnet close to the positioning surface, and white representing the S-pole of the magnet close to the positioning surface C. The polarities of the second magnet group 4 are distributed according to the opposite polarity rule, and the distance between the two magnet modules 7 and 8 is 50 mm.

[0040] By Figure 1 It can be seen that before the fixed surfaces C and D are connected and positioned, the detachable assembly 2 above has an initial deviation of 3 mm in the x direction.

[0041] By Figure 2 It can be seen that before the fixed surfaces C and D are connected and positioned, the detachable assembly 2 above has an initial deviation of 1 mm in the y direction.

[0042] The connection and positioning simulation of the two detachable assemblies 1 and 2 in the above separated state is performed, and the recovery displacement result is shown in Figure 3 , wherein:

[0043] Figure 3 (a) in the above shows that the recovery displacement of the detachable assembly 2 in the x direction is 2.95 mm, and no twisting phenomenon occurs;

[0044] Figure 3 (b) in the above shows that the maximum recovery displacement of the detachable assembly 2 in the y direction is 1.44 mm, and the minimum recovery displacement is 0.71 mm. Although there is a clear positioning recovery effect, there is a clear twisting.

[0045] Through finite element parameterized scanning simulation, it is finally determined that the magnetization intensity of each magnet in the two magnet groups 3 and 4 is 600 GS, and the magnetic attraction force of the detachable assembly 2 above in the z direction after connection is extracted, and the magnetic attraction force of the detachable assembly 2 above in the z direction is 10.7 N, which meets the requirement of magnetic attraction force.

[0046] For the excessive twisting in the y direction of the present example, the number, position and magnetization intensity of the magnets in the planar magnetic attraction connection and positioning device need to be optimized to achieve accurate positioning.

[0047] Referring to Figure 4 , the optimization method of the present example adopts different optimization measures for different positioning conditions after the detachable assemblies 1 and 2 are connected:

[0048] When the displacement is insufficient after the two detachable assemblies 1 and 2 are connected, the magnetic attraction is increased by increasing the number of magnets or increasing the magnetization intensity of the magnets, so as to increase the recovery displacement;

[0049] When the displacement is excessive after the two detachable assemblies 1 and 2 are connected, the magnetic attraction is reduced by reducing the number of magnets or reducing the magnetization intensity of the magnets, so as to reduce the recovery displacement;

[0050] When the torsion is excessive after the two detachable assemblies 1 and 2 are connected, the magnetic torque caused by the magnetic attraction is reduced by reducing the distance between the two magnet modules 7 and 8 or increasing the magnets for auxiliary positioning, so as to inhibit the excessive torsion of the upper detachable assembly 2.

[0051] In example 2, in the case of excessive torsion in the y direction after the upper detachable assembly 2 is positioned in example 1, the distance between the two magnet modules 7 and 8 in each magnet group is reduced to inhibit the torsion according to the planar connection positioning optimization method, and the optimized planar magnetic attraction connection positioning device is obtained as shown in Figure 5 .

[0052] The improvement of the present example is that the distance between the magnet modules 7 and 8 is shortened from 50 mm to 30 mm. The connection positioning simulation is performed on the optimized planar magnetic attraction connection positioning device, and the recovery displacement result is obtained as shown in Figure 6 . Among them:

[0053] Figure 6 (a) in FIG. 1 shows that the recovery displacement of the upper detachable assembly 2 in the x direction is 3.36 mm, and there is no torsion phenomenon, but there is an excessive recovery displacement;

[0054] Figure 6 (b) in FIG. 1 shows that the recovery displacement of the upper detachable assembly 2 in the y direction is 1.07 mm, and there is no torsion phenomenon.

[0055] The magnetization intensity of the magnet in the present example is the same as that in example 1, and the magnetic attraction of the upper detachable assembly 2 after connection in the z direction is extracted, and the magnetic attraction of the upper detachable assembly 2 in the z direction is obtained as 13.7 N, which meets the requirement of the magnetic attraction.

[0056] Compared with example 1, the present example well solves the problem of excessive torsion of the upper detachable assembly 2 in the y direction positioning, but the upper detachable assembly 2 in the x direction appears an excessive recovery displacement, that is, it exceeds the standard of 3.1 mm recovery displacement, so the magnet group is continuously optimized to inhibit the excessive recovery in the x direction.

[0057] In example 3, in the case of excessive recovery displacement in the x direction after the upper detachable assembly 2 is positioned in example 2, the magnetization intensity of the magnet group is reduced to reduce the recovery displacement according to the planar connection positioning optimization method.

[0058] The specific implementation of the present example is as follows:

[0059] 3.1) The magnetization intensity of the magnet is scanned by the finite element software, the positioning data obtained by the connection positioning simulation is used as the positioning data, the sum of the position deviations of the upper detachable assembly 2 in the x and y directions after connection is used as the objective function J, and the following plane connection positioning optimization model is established:

[0060] ;

[0061] Wherein x i1 is the number of magnets, x i2 is the position of the magnet, x i3 is the magnetization intensity of the magnet, F x is the position deviation of the upper detachable assembly 2 in the x direction after connection, and F y is the position deviation of the upper detachable assembly 2 in the y direction after connection.

[0062] 3.2) The magnet group distribution form that minimizes the objective function J is selected as the optimized magnet group distribution by means of the plane connection positioning optimization model:

[0063] First, a set of parameters to be optimized is input for connection positioning simulation, and the objective function J is obtained by referring to the simulation experiment results;

[0064] Then, the parameters to be optimized are continuously adjusted to minimize the objective function J by referring to the plane connection positioning optimization method, and the optimization parameters are controlled within a reasonable range during the adjustment of the optimization parameters. The set of optimization parameters with the minimum objective function value is used as the optimized model parameters, and a set of optimal magnet distribution modes is obtained.

[0065] The magnet groups 3 and 4 are embedded into the fixing planes C and D according to the optimal magnet distribution mode, and the plane connection positioning test is performed.

[0066] The magnetization intensity of the magnet in the magnet group is determined to be 500 GS by finite element parameterized scanning analysis and the plane connection positioning optimization model. The connection positioning simulation is performed on the optimized plane magnetic attraction connection positioning device, and the recovery displacement results are shown in Figure 7 , wherein:

[0067] Figure 7 (a) in the figure shows that the recovery displacement of the upper detachable assembly 2 in the x direction is 3.04 mm, and no twisting phenomenon occurs;

[0068] Figure 7 (b) in the figure shows that the recovery displacement of the upper detachable assembly 2 in the y direction is 0.95 mm, and no twisting phenomenon occurs.

[0069] After extraction, the magnetic attraction force of the detachable component 2 in the z direction was found to be 10.7N, which meets the requirements for magnetic attraction force.

[0070] Compared to Example 2, in this example, the excessive recovery displacement of the detachable component 2 in the x-direction is well suppressed, and no torsion occurs in either the x or y directions. This demonstrates that the magnet arrangement method used in Example 3 can effectively achieve the connection and positioning of the two detachable components.

[0071] Example 4: Addressing the issue of excessive torsion in the y-direction of the detachable component 2 after positioning in Example 1, an auxiliary positioning magnet is added to both ends of each magnet group to suppress the torsion in the y-direction, based on the planar connection positioning optimization method. The optimized planar magnetic connection positioning device is determined through finite element parametric scanning analysis and the planar connection positioning optimization model, as follows: Figure 8 As shown.

[0072] The improvement in this example is the addition of six 3×3×3 (mm) cube-shaped auxiliary positioning magnets at each end of each magnet group. These cube magnets have a magnetization of 150 GS, compared to the original 450 GS magnetization of each cuboid magnet. The polarity distribution at points E and F is as follows: Figure 9 As shown, black represents the N pole of the magnet near the surface, and white represents the S pole of the magnet near the C pole of the surface.

[0073] right Figure 8 The optimized planar magnetic connection positioning device shown was subjected to connection and positioning simulation, and the recovery displacement results are as follows: Figure 10 As shown. Wherein:

[0074] Figure 10 (a) shows that the removable component 2 has a recovery displacement of 2.96 mm in the x direction, and no torsion is observed.

[0075] Figure 10 (b) shows that the removable component 2 has a recovery displacement of 0.95 mm in the y direction, and no torsion is observed.

[0076] Extracting the magnetic attraction force of the detachable component 2 in the z direction after connection, we find that the magnetic attraction force of the detachable component 2 in the z direction is 10.5N, which meets the requirements for magnetic attraction force.

[0077] Compared to Embodiment 1, in this example, excessive torsion of the detachable component 2 in the y-direction is well suppressed, and no excessive displacement occurs in either the x or y directions. This demonstrates that the magnet arrangement used in Embodiment 4 effectively achieves the connection and positioning of the two detachable components.

Claims

1. An optimization method of a detachable planar magnetic attraction connection positioning device, the device comprising two detachable components (1, 2) and two magnet groups (3, 4), wherein the two detachable components (1, 2) are both in planar structures without any protrusions or grooves for mechanical positioning, as upper and lower two fixed surfaces C and D; the two magnet groups (3, 4) are completely embedded into the fixed surfaces C and D respectively according to the polarity of mutual attraction, realizing the connection and positioning of the two planes; the array form of the magnets of the two magnet groups (3, 4) is completely the same, each magnet group is composed of two magnet modules (7, 8), each magnet module includes an odd number of magnets, the two magnet modules are placed separately and embedded into a plane, the two magnet groups are distributed according to the rule of adjacent magnet polarity staggering and are embedded into the fixed surfaces C and D respectively; characterized in that: The optimization method is to achieve the effect of precise positioning of the detachable assembly by optimizing the number, position and magnetization strength of the magnets in the two magnet groups: When the displacement of the detachable assembly (1, 2) is insufficient after connection, increase the number of magnets or increase the magnetization strength to increase the recovery displacement; When the displacement of the detachable assembly (1, 2) is excessive after connection, reduce the number of magnets or reduce the magnetization strength to reduce the recovery displacement; When the twist of the detachable assembly (1, 2) is excessive after connection, reduce the distance between the two magnet modules (7, 8) or increase the magnets for auxiliary positioning to suppress the twist; By scaling up or down the magnetization strength of the magnets, the magnetic attraction force during connection is adjusted to the expected magnetic attraction force; The implementation steps to suppress the excessive displacement or twist of the detachable assembly (1, 2) after connection are as follows: First, parameterize the magnetization strength of the magnets by finite element software, and obtain the positioning data from the connection positioning simulation. Take the sum of the square of the position deviation of the upper detachable assembly (2) in the x and y directions after connection as the objective function J, and establish the following plane connection positioning optimization model: ； where x i1 is the number of magnets, x i2 is the position of the magnets, x i3 is the magnetization of the magnets, F x is the position deviation of the upper detachable assembly (2) in the x direction after connection, F y is the position deviation of the upper detachable assembly (2) in the y direction after connection; Next, input a set of parameters to be optimized for connection positioning simulation, and refer to the simulation results to obtain the objective function J; Then, continuously adjust the parameters to be optimized according to the plane connection positioning optimization method to minimize the objective function J. Take the set of optimized parameters with the minimum objective function value as the optimized parameters, and obtain a set of optimal magnet distribution modes; Finally, refer to the optimal magnet distribution mode to determine the distance between the two magnet modules (7, 8) with a positioning error of 0.1 mm, the magnetization strength and number of magnets.

2. The method of claim 1, wherein: Suppress the excessive twist of the two detachable assemblies by increasing auxiliary positioning magnets, wherein: Increase n x m auxiliary positioning magnets on both sides of the magnet group, and the magnetization strength of each auxiliary positioning magnet is less than that of the magnets in the modules (7, 8); Parameterize and scan the array form and magnetization strength of the auxiliary magnets by finite element software, and select the spacing that can achieve a positioning error of 0.1 mm as the optimized array form and magnetization strength according to the simulation results.

3. The method of claim 1, wherein: The use steps of the detachable plane magnetic attraction connection positioning device include: embedding two magnet groups (3, 4) in the two devices to be connected according to the polarity of mutual attraction, and with the adjacent magnets in each magnet group distributed in an alternating manner, placing the first device to be connected on a horizontal table, and placing the second device to be connected above the first device to be connected, and realizing the positioning and connection between the two by the attraction between the magnet groups (3, 4); When separating the connected devices, horizontally push the second device to be connected, and repel the magnets with the same polarity to reduce the force required to separate the two.

4. The method of claim 1, wherein: The two detachable assemblies (1, 2) use magnetically conductive but not magnetized materials.

5. The method of claim 1, wherein: The length of each magnet module is between 1 / 6 and 1 / 4 of the length of the shorter plane in the fixed surface C and the fixed surface D, to achieve better positioning accuracy.

Images