Middle frame, shell assembly and electronic equipment

Abstract

The utility model relates to the technical field of electronic equipment, and discloses a middle frame, a shell assembly and electronic equipment. The middle frame comprises a first outer frame, a first middle plate and a welding seam structure located between the first outer frame and the first middle plate, the first outer frame surrounds the outer side wall of the first middle plate, and the first outer frame and the first middle plate are connected through the welding seam structure; wherein the first outer frame comprises a hollow frame and a protruding part, the protruding part is located at at least one first corner of the inner side wall of the hollow frame, at least one second corner of the first middle plate is provided with a concave part corresponding to the protruding part of the first outer frame, and the material strength of the protruding part is larger than that of the first middle plate; as the inner side wall of the first outer frame is provided with the protruding part, the original corner position of the joint of the first outer frame and the first middle plate can be better protected, and therefore the weight of the middle frame is reduced, and meanwhile the overall strength and the anti-falling performance of the middle frame can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of electronic equipment, and in particular to a middle frame, a housing assembly and an electronic device. Background Art

[0002] As electronic devices tend to be lighter and thinner, the middle frames of devices are also getting thinner. The performance of middle frames made of a single material can no longer meet the needs of weight reduction. Therefore, more and more middle frames of electronic devices are made of magnesium-aluminum composite structures. Aluminum-magnesium and its alloys have the advantages of low material density, high specific strength, high specific stiffness, strong shock absorption performance and electromagnetic shielding.

[0003] However, the bonding method of magnesium alloy and aluminum alloy is currently a difficult problem. How to improve the bonding strength of magnesium-aluminum alloy so as to improve the performance of the middle frame while reducing weight is a problem that needs to be solved urgently. Utility Model Content

[0004] The embodiments of the present application provide a middle frame, a shell assembly, and an electronic device, which are used to improve the overall strength of the middle frame and improve defects such as deformation or damage of the middle frame under the influence of external forces.

[0005] In a first aspect, the present application provides a middle frame, which includes a first outer frame, a first middle plate and a weld structure located between the first outer frame and the first middle plate, the first outer frame surrounds the outer wall of the first middle plate, and the first outer frame and the first middle plate are connected by the weld structure; wherein, the first outer frame includes a hollow frame and a protrusion, the protrusion is located at at least one first corner of the inner wall of the hollow frame, and at least one second corner of the first middle plate has a recessed portion corresponding to the protrusion of the first outer frame, and the material strength of the protrusion is greater than the material strength of the first middle plate.

[0006] According to the embodiment of the present application, since the protrusion of the first outer frame occupies the position of the corresponding recessed portion of the first middle plate, and the material strength of the protrusion is greater than that of the first middle plate, the connection position at the first corner and the second corner is less affected by external force deformation and has strong resistance to falling. The original corner position of the connection between the first outer frame and the first middle plate can be better protected to prevent the original corner position of the middle frame from being damaged and deformed when it falls or is hit by other external forces, thereby preventing the first outer frame and the first middle plate from separating, and the middle frame as a whole is not easy to deform or damage, thereby improving the overall strength of the middle frame.

[0007] In some embodiments of the first aspect above, the hollow frame and the protrusion are an integrally formed structure, and both the hollow frame and the protrusion are made of a first material, and the first middle plate is made of a second material, wherein the material strength of the first material is greater than the material strength of the second material.

[0008] In this way, the original corner position of the connection between the first outer frame and the first middle plate can be better protected to prevent damage caused by the middle frame falling. While ensuring the weight reduction of the middle frame, the overall strength and anti-fall performance of the middle frame can also be improved.

[0009] In some embodiments of the first aspect above, the hollow frame is made of a first material, the first middle plate is made of a second material, and the protrusion is made of a third material, wherein the material strength of the first material and the material strength of the third material are both greater than the material strength of the second material.

[0010] In this way, while ensuring the weight of the middle frame, the overall strength and drop resistance of the middle frame can also be improved.

[0011] In some embodiments of the first aspect above, the hollow frame includes at least one of a rectangular hollow frame, a triangular hollow frame, a pentagonal hollow frame, and a hexagonal hollow frame.

[0012] In this way, the protrusions are arranged in hollow frames with different shapes, which can protect the middle frame and improve the anti-drop performance of the middle frame.

[0013] In some embodiments of the first aspect above, the first corner is sharp or arc-shaped.

[0014] In this way, the protruding portion can be applicable to first corners of different shapes, thereby protecting the connection performance between the first outer frame and the first middle plate at the first corner.

[0015] In some embodiments of the first aspect above, the second corner is sharp or arc-shaped.

[0016] In this way, the protruding portion can be applicable to second corners of different shapes, thereby protecting the connection performance between the first outer frame and the first middle plate at the second corner.

[0017] In some embodiments of the first aspect above, the first middle plate includes a first sub-plate and a second sub-plate arranged at intervals, a portion of the first outer frame is provided between the first sub-plate and the second sub-plate, and the second corner includes at least one of the outer wall corner of the first sub-plate and the outer wall corner of the second sub-plate.

[0018] In this way, two different welding designs can be used on the front and back of the middle frame respectively, so that the front of the middle frame is welded twice and the back is welded once, thereby reducing one welding process on the back and thus improving the welding efficiency.

[0019] In some embodiments of the first aspect described above, a cross-sectional shape of the protrusion perpendicular to its thickness direction includes at least one of a rectangle, a square, a triangle, a trapezoid, a circle, a step shape, and an L shape.

[0020] In this way, the shape of the protruding portion can be adapted to the corner shape of the inner side wall of the hollow frame and the corner shape of the outer side wall of the first middle plate, thereby better improving the strength of the middle frame.

[0021] In some embodiments of the first aspect above, shapes of different protrusions in the same middle frame are the same or different.

[0022] In some embodiments of the first aspect described above, the material of the first outer frame includes aluminum alloy, and the material of the first middle plate includes magnesium alloy.

[0023] In this way, the overall strength and drop resistance of the middle frame can be improved while reducing weight.

[0024] In some embodiments of the first aspect described above, the weld structure comprises a friction stir weld structure.

[0025] In this way, the defect that the first outer frame and the first middle plate are easily separated when the middle frame is hit by external force can be prevented.

[0026] In some embodiments of the first aspect above, the middle frame further includes a key hole, and the key hole is arranged on the first middle plate.

[0027] In a second aspect, an embodiment of the present application provides a shell assembly, which includes a shell and a middle frame of the first aspect, and the shell and the middle frame together enclose a receiving cavity of the electronic device.

[0028] It can be understood that the above-mentioned shell assembly can resist defects such as deformation or damage under the influence of external forces, thereby improving its own anti-drop performance and overall strength.

[0029] In a third aspect, an embodiment of the present application provides an electronic device, comprising a shell and a middle frame according to the first aspect, wherein the shell and the middle frame together enclose a receiving cavity of the electronic device.

[0030] It can be understood that the above-mentioned electronic device can reduce its weight while improving its own anti-drop performance, thereby improving the overall strength of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present application, the drawings used in the description of the implementation methods are briefly introduced below.

[0032] Figure 1 According to some embodiments of the present application, a schematic diagram of a three-dimensional structure of a laptop computer 20 is shown;

[0033] Figure 2 According to some embodiments of the present application, a three-dimensional structural schematic diagram of a riveted middle frame 200 is shown;

[0034] Figure 3According to some embodiments of the present application, a schematic diagram of a three-dimensional structure of an embedded cast middle frame 200' is shown;

[0035] Figure 4 According to some embodiments of the present application, a cross-sectional schematic diagram of a friction stir welding middle frame 300 ′ is shown;

[0036] Figure 5A According to some embodiments of the present application, a cross-sectional schematic diagram of a first middle frame 300 is shown;

[0037] Figure 5B According to some embodiments of the present application, a cross-sectional schematic diagram of a second middle frame 300 is shown;

[0038] Fig. 6A According to some embodiments of the present application, a cross-sectional schematic diagram of a third middle frame 300" is shown;

[0039] Figure 6B According to some embodiments of the present application, a cross-sectional schematic diagram of a fourth middle frame 300" is shown;

[0040] Fig. 7A According to some embodiments of the present application, a schematic diagram of a three-dimensional structure of a first middle frame 400 is shown;

[0041] Figure 7B According to some embodiments of the present application, a cross-sectional schematic diagram of a fifth middle frame 400 is shown;

[0042] Figure 7C According to some embodiments of the present application, a cross-sectional schematic diagram of a sixth middle frame 400 is shown;

[0043] Fig. 8A According to some embodiments of the present application, a cross-sectional schematic diagram of a seventh middle frame 400 is shown;

[0044] Figure 8B According to some embodiments of the present application, a cross-sectional schematic diagram of an eighth middle frame 400 is shown;

[0045] Fig. 9A According to some embodiments of the present application, a cross-sectional schematic diagram of a ninth middle frame 500 is shown;

[0046] Fig. 9B According to some embodiments of the present application, a cross-sectional schematic diagram of a tenth middle frame 500 is shown;

[0047] Fig. 9C According to some embodiments of the present application, a cross-sectional schematic diagram of an eleventh middle frame 500 is shown;

[0048] Fig. 10AAccording to some embodiments of the present application, a cross-sectional schematic diagram of a twelfth middle frame 500 is shown;

[0049] Fig. 10B According to some embodiments of the present application, a cross-sectional schematic diagram of a thirteenth middle frame 500 is shown;

[0050] Fig. 10C According to some embodiments of the present application, a schematic cross-sectional view of a fourteenth middle frame 500 is shown;

[0051] Fig.11A According to some embodiments of the present application, a schematic diagram of a three-dimensional structure of a second middle frame 600 is shown;

[0052] Fig. 11B According to some embodiments of the present application, a cross-sectional schematic diagram of a fifteenth middle frame 600 is shown;

[0053] Fig. 11C According to some embodiments of the present application, a cross-sectional schematic diagram of a sixteenth middle frame 600 is shown;

[0054] Fig. 12A According to some embodiments of the present application, a cross-sectional schematic diagram of a seventeenth middle frame 600 is shown;

[0055] Fig. 12B According to some embodiments of the present application, a cross-sectional schematic diagram of an eighteenth middle frame 600 is shown;

[0056] Fig. 12C According to some embodiments of the present application, a cross-sectional schematic diagram of a nineteenth middle frame 600 is shown;

[0057] Fig.13 According to some embodiments of the present application, a cross-sectional schematic diagram of a twentieth middle frame 700 is shown;

[0058] Fig.14 According to some embodiments of the present application, a schematic flow chart of a method for preparing a middle frame is shown;

[0059] Fig.15 According to some embodiments of the present application, a schematic structural diagram of an electronic device 100 is shown.

[0060] Description of reference numerals:

[0061] 200, middle frame; 210, aluminum outer frame; 220, magnesium middle plate; 230, riveted structure; 200', middle frame; 210', aluminum outer frame; 220', magnesium middle plate; 300', middle frame; 310', aluminum outer frame; 320', magnesium middle plate;

[0062] 300, middle frame; 310, first outer frame; 311, hollow frame; 312, protrusion; 320, first middle plate; 330, weld structure; 340, keyhole; A1, first corner; A2, second corner;

[0063] 300", middle frame; 310", first outer frame; 311", hollow frame; 312", protrusion; 320", first middle plate; 330", weld structure; 340", keyhole; B1, first corner; B2, second corner;

[0064] 400, middle frame; 410, first outer frame; 411, hollow frame; 412, protrusion; 420, first middle plate; 430, weld structure; 440, keyhole; C1, first corner; C2, second corner;

[0065] 500, middle frame; 510, first outer frame; 511, hollow frame; 512, protrusion; 520, first middle plate; 521, first sub-plate; 522, second sub-plate; 530, weld structure; 540, keyhole; D1, first corner; D2, second corner;

[0066] 600, middle frame; 610, first outer frame; 611, hollow frame; 612, protrusion; 620, first middle plate; 621, first sub-plate; 622, second sub-plate; 630, weld structure; 640, keyhole; E1, first corner; E2, second corner;

[0067] 700, middle frame; 710, first outer frame; 720, first middle plate; 730, weld structure. DETAILED DESCRIPTION

[0068] The illustrative embodiments of the present application include, but are not limited to, a middle frame, a housing assembly, and an electronic device.

[0069] For ease of understanding, the following briefly introduces the terms used in some embodiments.

[0070] Specific strength is the strength of a material (the force per unit area when it is broken) divided by its density. The higher the specific strength, the lighter the material used to achieve the corresponding strength. Specific strength can be an indicator data used to measure the strength of a material.

[0071] Specific stiffness is the ratio of the elastic modulus of a material to its density, also known as "specific modulus" or "specific elastic modulus". A higher specific stiffness means that the material is lighter at the same stiffness, or has greater stiffness at the same mass. Specific stiffness can be an indicator data used to measure the stiffness of a material.

[0072] Anodic oxidation is the electrochemical oxidation of metals or alloys. Aluminum and its alloys form an oxide film on aluminum products (anodes) under the action of an applied current in the corresponding electrolyte and specific process conditions. A process of electrolytic oxidation to obtain a porous, dense, flat and uniform oxide film. The oxide film has protective, decorative and other functional properties.

[0073] The heat of fusion refers to the amount of heat that a unit mass of crystal needs to absorb when it melts and turns into a liquid substance at the same temperature. It is also equal to the heat released when a unit mass of the same substance changes from liquid to solid at the melting point under the same pressure.

[0074] Metallurgical bond refers to the bond formed by the mutual diffusion of atoms between the interfaces of two metals.

[0075] The weld strength coefficient refers to the ratio of the weld joint strength to the parent material strength. It is used to reflect the degree to which the weld joint strength is weakened due to factors such as welding materials, welding defects and welding residual stress. It is a comprehensive reflection of the mechanical properties of the weld joint. The weld strength coefficient can be used to indicate the reliability of the weld quality.

[0076] The primary appearance surface (high-gloss surface), also known as the A-level surface, is the surface that users can often see when the electronic device is in use; such as the front and top of the chassis.

[0077] The embodiment of the present application provides a middle frame, a housing assembly and an electronic device. The middle frame can be applied to the housing of the electronic device to support the electronic components in the housing of the electronic device. Figure 1 A schematic diagram of an application of the middle frame is shown. Figure 1 As shown, the middle frame can be applied to a notebook computer 20 .

[0078] It can be understood that the electronic devices of the embodiments of the present application may include but are not limited to mobile phones, tablet computers, laptops, cameras, ultra mobile personal computers (UMPCs), handheld computers, televisions, walkie-talkies, netbooks, POS machines, personal digital assistants (PDAs), wearable devices, virtual reality devices, smart vehicles, smart robots, industrial equipment, display screens, servers, and other devices with a middle frame, and the present application does not impose any restrictions on this.

[0079] As mentioned above, with the increasing trend of weight reduction in electronic equipment, if the middle frame is made of pure aluminum, it will be heavy. If only the lighter pure magnesium middle frame is used, the appearance will be poor and the strength will be low, and the drop resistance will be poor, resulting in poor performance of the middle frame. Therefore, the industry generally uses magnesium-aluminum composite structures (for example, a combination of an aluminum outer frame and a magnesium inner frame) instead of a single aluminum to prepare the middle frame, thereby reducing the weight of the middle frame. Aluminum-magnesium and their alloys have low material density (the density of aluminum is 2.7g / cm 3 , the density of magnesium is 1.8g / cm 3 ), high specific strength (aluminum's specific strength is 57, magnesium's specific strength is 191), high specific stiffness (aluminum's specific stiffness is 2.64, magnesium's specific stiffness is 2.45), and magnesium material also has excellent shock absorption performance and electromagnetic shielding function. The combination of aluminum outer frame and magnesium inner frame can achieve a good weight reduction effect while ensuring the strength of the middle frame and the anodized appearance. However, how to closely combine magnesium alloy and aluminum alloy is a problem that needs to be solved.

[0080] At present, the main methods of connecting magnesium alloy and aluminum alloy are brazing, riveting and embedding. Among them, brazing refers to a welding method in which the solder and the weldment are heated to the melting temperature of the solder at the same time, and the gap of the solid workpiece is filled with liquid solder to connect the metals. In brazing welding technology, due to the different thermal expansion coefficients of aluminum and magnesium, welding internal stress will be induced during the welding process, and the difference in melting point, melting heat, thermal conductivity and thermal expansion coefficient of aluminum and magnesium will affect the welding thermal cycle and temperature field distribution, thereby causing problems such as thermal cracks, pores, alloy element burnout and softening of the weld zone. In addition, since a dense oxide film is easily formed on the surface of aluminum and magnesium, it hinders atomic diffusion and metallurgical bonding during welding, and the aluminum-magnesium eutectic reaction temperature is low (about 437°C), the eutectic reaction will form a hard and brittle intermetallic compound (IMC), which seriously affects the performance of the aluminum-magnesium joint.

[0081] Figure 2 2 shows a schematic diagram of a middle frame 200, which includes an aluminum outer frame 210 and a magnesium middle plate 220. The aluminum outer frame 210 and the magnesium middle plate 220 are formed by riveting, that is, the aluminum outer frame 210 and the magnesium middle plate 220 are connected by a riveting structure 230. Figure 2It can be seen that the riveted structure 230 connects the aluminum outer frame 210 and the magnesium middle plate 220 in a local connection manner, that is, the riveted structure 230 does not connect all positions of the aluminum-magnesium edge. Therefore, the bonding strength between the aluminum outer frame 210 and the magnesium middle plate 220 is low, the middle frame 200 is prone to wear and tear, and the heat dissipation effect is poor. In addition, the bolt fixing position in the riveted structure 230 is easily affected by external forces and fails, which leads to the separation of different components in the middle frame 200.

[0082] Figure 3 , a schematic diagram of a middle frame 200' is shown, the middle frame 200' comprises an aluminum outer frame 210' and a magnesium middle plate 220', and the aluminum outer frame 210' and the magnesium middle plate 220' are formed by insert casting. The magnesium middle plate 220' is connected to the aluminum outer frame 210' by die casting, i.e., insert casting. Specifically, the aluminum outer frame 210' is placed in a die casting mold, and then the molten magnesium alloy liquid flows into the fixing groove on the aluminum outer frame 210'. After the magnesium alloy liquid is cooled and formed, the magnesium middle plate 220' is formed, so that the magnesium middle plate 220' is installed in the aluminum outer frame 210', and the two are connected as one. In the above-mentioned middle frame 200', although the edges of the aluminum outer frame 210' and the magnesium middle plate 220' are connected at all positions, the strength of the die-cast magnesium middle plate 220' is low, and the aluminum outer frame 210' and the magnesium middle plate 220' are not metallurgically bonded, and the difference in thermal expansion coefficients easily leads to separation of the two. Therefore, how to improve the bonding strength of magnesium-aluminum alloys is an urgent problem to be solved.

[0083] Figure 4 A schematic diagram of a middle frame 300' is shown in the figure. The middle frame 300' includes an aluminum outer frame 310' and a magnesium middle plate 320'. The aluminum outer frame 310' and the magnesium middle plate 320' are welded by friction stir welding (FSW). Friction stir welding, as a low-temperature solid-phase welding technology, is applied to the welding of low-melting-point metal materials. The technology has the advantages of high connection quality, small welding deformation, green and pollution-free welding process, high degree of automation, and low welding cost. It can improve the defects of cracks, pores or slag inclusions that are prone to occur in other welding methods. However, as Figure 4 As shown, the corner position A where the aluminum outer frame 310' and the magnesium middle plate 320' are connected has a large and sharp corner compared to other connection positions, so the bonding performance between the aluminum outer frame 310' and the magnesium middle plate 320' is poor. When the middle frame 300' falls or is hit by other external forces, the corner position A is easily damaged and deformed, and even causes the aluminum outer frame 310' and the magnesium middle plate 320' to separate. Therefore, the overall drop resistance of the middle frame 300' is poor.

[0084] The middle frame provided in this embodiment is used to improve the above-mentioned problems. In the embodiment of the present application, the aluminum outer frame is connected to the magnesium middle plate by stir friction welding, and a protrusion is set at the original corner in the aluminum outer frame. The material of the protrusion is used to occupy and replace the original corner position of the edge of the magnesium middle plate. Therefore, the original corner position of the connection between the aluminum outer frame and the magnesium middle plate can be better protected, thereby preventing the original corner position of the middle frame from being damaged and deformed when it falls or is hit by other external forces, and avoiding the separation of the aluminum outer frame and the magnesium middle plate. In this way, the bonding strength between the aluminum outer frame and the magnesium middle plate can be improved to improve the overall strength of the middle frame, and improve the defects of the middle frame such as deformation or damage under the influence of external forces.

[0085] It should be noted that the directional terms such as "front", "back", "up", "down", "left", and "right" herein are exemplary directions of the middle frame, and do not indicate or imply that the components referred to must have a specific direction, which may change accordingly according to actual use and cannot be understood as limitations on the present application. In addition, the length direction described in the embodiments of the present application may be the x direction in the drawings, the width direction may be the y direction in the drawings, and the thickness direction may be the z direction in the drawings.

[0086] Figure 5A A schematic cross-sectional view of a middle frame 300 perpendicular to the thickness direction is shown, and the middle frame 300 provided in this embodiment is used to improve the above-mentioned problem. In the embodiment of the present application, the middle frame 300 includes a first outer frame 310, a first middle plate 320, and a weld structure 330 located between the first outer frame 310 and the first middle plate 320, the first outer frame 310 surrounds the outer side wall of the first middle plate 320, and the first outer frame 310 and the first middle plate 320 are connected by the weld structure 330. Among them, the first outer frame 310 includes a hollow frame 311 and a protrusion 312, the protrusion 312 is located at at least one first corner A1 of the inner side wall of the hollow frame 311, and at least one second corner A2 of the first middle plate 320 has a recessed portion corresponding to the protrusion 312 of the first outer frame 310; at least one first corner A1 corresponds to at least one second corner A2, and the material strength of the protrusion 312 is greater than the material strength of the first middle plate 320. In the above-mentioned middle frame 300, since the protrusion 312 of the first outer frame 310 occupies the position of the corresponding recessed portion of the first middle plate 320, and the material strength of the protrusion 312 is greater than the material strength of the first middle plate 320, the connection position at the first corner A1 and the second corner A2 is less affected by external force deformation and has strong resistance to falling. The original corner position of the connection between the first outer frame 310 and the first middle plate 320 can be better protected to prevent the original corner position of the middle frame 300 from being damaged and deformed when it falls or is hit by other external forces, thereby preventing the first outer frame 310 and the first middle plate 320 from separating, and the middle frame 300 as a whole is not easy to deform or damage, thereby improving the overall strength of the middle frame 300.

[0087] In some embodiments of the present application, the hollow frame and the protrusion are an integrally formed structure, and the hollow frame and the protrusion are made of the same material, both of which are the first material, and the first middle plate is the second material; wherein the material strength of the first material is greater than the material strength of the second material, thereby better protecting the original corner position of the connection between the first outer frame and the first middle plate, and preventing damage caused by the middle frame falling.

[0088] In some embodiments of the present application, the hollow frame is made of a first material, the first middle plate is made of a second material, and the protrusion is made of a third material, that is, the materials of the hollow frame and the protrusion may be different; wherein the material strength of the first material and the material strength of the third material are both greater than the material strength of the second material, thereby ensuring that the weight of the middle frame is reduced while also being able to improve the overall strength and drop resistance of the middle frame.

[0089] It should be noted that the first corner is the corner of the inner wall of the hollow frame, and the second corner is the corner of the outer wall of the first middle plate. The inner wall of the hollow frame and the outer wall of the first middle plate are connected by a weld structure, and the seam width of the weld structure at different positions is roughly uniform. Therefore, the shape contour of the inner wall of the hollow frame and the outer wall of the first middle plate are roughly the same. At this time, the positions of the first corner and the second corner are also corresponding.

[0090] At least one first corner A1 corresponds to at least one second corner A2, including: one first corner A1 can correspond to multiple second corners A2, or one second corner A2 can also correspond to multiple first corners A1, or the first corner A1 corresponds to the second corner A2 one by one.

[0091] exist Figure 5A In the embodiment, the hollow frame 311 is a rectangular hollow frame, that is, the outer contour and the inner contour of the hollow frame 311 are both rectangular frames, so the rectangular frame of its inner contour has four sides and four corners, that is, the first corner A1 corresponds to at least one of the four corners of the inner contour of the rectangular hollow frame. The protrusion 312 is located at all the first corners A1 of the inner wall of the hollow frame 311. In other examples where the hollow frame 311 is a rectangular hollow frame, the protrusion 312 can also be located at one corner, two corners or three corners of the inner wall of the hollow frame 311, which is not limited here.

[0092] In other embodiments of the present application, the hollow frame can also be other polygonal frames, such as a triangular hollow frame, a pentagonal hollow frame, a hexagonal hollow frame, etc. Correspondingly, the first middle plate can also be a polygonal middle plate, such as a triangular middle plate, a pentagonal middle plate, a hexagonal middle plate, etc., and the first corner includes at least one of the corners of the inner wall of the polygonal hollow frame, and the second corner includes at least one of the corners of the outer wall of the polygonal middle plate. The number of the first corner and the second corner, and the shape of the inner wall of the hollow frame are not limited, and the protrusion can be set at all corners of the inner wall of the hollow frame, or at one or several corners, which is not limited here. The above-mentioned protrusions set in hollow frames with different shapes can protect the middle frame and improve the anti-drop performance of the middle frame.

[0093] In some embodiments of the present application, the first corner is sharp or arc-shaped, so that the protrusion can be applicable to first corners of different shapes, thereby protecting the connection performance between the first outer frame and the first middle plate at the first corner.

[0094] In some embodiments of the present application, the second corner is sharp or arc-shaped, so that the protrusion can be applicable to second corners of different shapes, thereby protecting the connection performance of the first outer frame and the first middle plate at the second corner.

[0095] In the embodiment of the present application, the cross-sectional shape of the protrusion perpendicular to the thickness direction may include a rectangle, a square, a triangle, a trapezoid, a circle, a step, an L-shape or other regular / irregular shapes, etc. The shape of the protrusion is adapted to the corner shape of the inner wall of the hollow frame and the corner shape of the outer wall of the first middle plate. Figure 5A In the middle frame 300 shown, the cross-sectional shape of the protrusion perpendicular to the thickness direction is a rectangle and a trapezoid. After the protrusion is provided, the original corner between the first outer frame and the first middle plate can be eliminated or replaced with a smaller corner, thereby reducing or dispersing the pressure on the original corner when hit by external force, thereby improving the disadvantage of the original corner being easy to deform.

[0096] In some embodiments of the present application, the shapes of different protrusions in the same middle frame may be the same.

[0097] In some embodiments of the present application, the shapes of different protrusions in the same middle frame may be different.

[0098] In the embodiment of the present application, the range of the weld strength coefficient may be greater than or equal to 0.5. For example, the weld strength coefficient may be 0.6, 0.7, 0.8 or 0.9, etc.

[0099] In the embodiment of the present application, the distance between the center of the weld and the surface of the first outer frame (anode appearance surface) may be greater than or equal to 5 mm. For example, the distance between the center of the weld and the surface of the first outer frame may be 10 mm, 20 mm or 30 mm, etc.

[0100] In an embodiment of the present application, the weld appearance surface (part of the outer surface of the weld structure exposed to the outside) includes a micro-arc oxidation (MAO) material (ceramic layer).

[0101] In an embodiment of the present application, the first outer frame may be an aluminum outer frame, and the first middle plate may be a magnesium middle plate, that is, the material of the first outer frame may include an aluminum alloy, and the material of the first middle plate may include a magnesium alloy. The weld structure may be a structure obtained by using a stir friction welding technique, that is, the components of the weld structure may include the same material components as the aluminum outer frame and the magnesium middle plate, that is, a mixture of an aluminum alloy and a magnesium alloy. Since aluminum alloys have high stability, high tensile strength, little influence of deformation by external forces, and strong drop resistance, the weld structure can metallurgically combine aluminum alloys and magnesium alloys, tightly connect the two, and reduce the risk of separation due to external forces.

[0102] In an embodiment of the present application, the aluminum outer frame comprises an extruded profile.

[0103] In addition, by providing the protrusion 312 in the first outer frame 310 and the recess in the first middle plate 320, during the anodizing process of the first outer frame 310 or the first middle plate 320, the protrusion 312 and the recess can also provide hanging points for the first outer frame 310 and the first middle plate 320, thereby improving the quality of anodizing and improving the appearance after anodizing. Moreover, the provision of the first middle plate 320 can also meet the requirement of reducing the weight of the middle frame 300. The middle frame 300 formed by combining the first middle plate 320 with the first outer frame 310 can ensure the thinness of the electronic device while improving the strength of the middle frame 300.

[0104] Figure 5A The middle frame shown also includes a keyhole 340, which is a hole structure located on the first middle plate 320. After the first outer frame 310 and the first middle plate 320 are subjected to friction stir welding, a hole structure left at the end position of welding when the weld structure 330 is formed is the keyhole 340. The keyhole 340 can reflect the end position of the friction stir welding, and it can be set to different positions according to different welding paths, welding shapes or other welding parameters. In the embodiment of the present application, the position of the keyhole can also be adaptively adjusted according to the overall design of the electronic device, so as to better adapt to the design of other structures in the electronic device.

[0105] The cross-sectional view of the middle frame shown in the figures of each embodiment of the present application may be a front view or a back view of the middle frame. Figure 5A The middle frame cross-section shown is regarded as a front view. Figure 5B Shows Figure 5A Schematic diagram of the back side of the middle frame, the back side and the front side of the middle frame can adopt the same welding path and welding method, that is, stir friction welding is adopted, and the welding paths overlap, so that the weld structure 330 on the front and back sides overlaps into an integrated structure.

[0106] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0107] Combine the following Fig. 6A and Figure 6B The first embodiment of the present application is described in detail.

[0108] Fig. 6A and Figure 6B The schematic diagram shown is a schematic diagram of the front and back sides of the middle frame 300 ″ and its welding path and size. Among them, the middle frame 300 ″ includes a first outer frame 310 ″, a first middle plate 320 ″, a weld structure 330 ″ and a keyhole 340 ″, and the first outer frame 310 ″ includes a hollow frame 311 ″ and three protrusions 312 ″.

[0109] The hollow frame 311" can be a rectangular hollow frame, that is, its inner and outer walls are both rectangular frames, or rectangular frames with arc corners, and the cross-section of the protrusion perpendicular to the z-direction can be rectangular or trapezoidal, or rectangular or trapezoidal with arc-shaped corners. The inner wall of the hollow frame 311" has a first corner B1, and one first corner B1 corresponds to the three second corners B2 in the outer wall of the first middle plate 320".

[0110] In addition, the weld structures on the front and back sides of the middle frame overlap, so the weld shapes and corresponding dimensions on the front and back sides of the middle frame are the same.

[0111] by Fig. 6ATaking the protrusion 312" in the upper left corner as an example, the protrusion 312" has a first side 312"a extending along the y direction, and the distance from the first side 312"a of the protrusion 312" to the first side 311"a of the outer side wall of the adjacent hollow frame 311" extending along the y direction is x1, and the distance from the first side 311"a of the outer side wall of the hollow frame 311" to the inner side wall adjacent to it is x1', and x1 is greater than x1'; similarly, the protrusion 312" has a second side 312"b extending along the x direction, and the protrusion 312" second side 312"b extending along the x direction The distance from the edge 312"b to the second edge 311"b of the outer side wall of the adjacent hollow frame 311" extending along the x direction is y1, and the distance from the second edge 311"b of the outer side wall of the hollow frame 311" to the inner side wall adjacent to it is y1', and y1 is greater than y1'. Therefore, the protrusion 312" can occupy the corner position of the inner side wall of the hollow frame 311", thereby improving the connection performance of the weld structure 330" between the first outer frame 310" and the first middle plate 320" at the corner, and improving the anti-drop performance of the middle frame 300".

[0112] Specifically, the range of x1 may be 20mm-80mm, the range of x1' may be 10mm-70mm, the range of y1 may be 20mm-80mm, and the range of y1' may be 10mm-70mm. For example, x1 may be 20mm, 50mm, 60mm, or 80mm, etc., x1' may be 10mm, 30mm, 50mm, or 70mm, etc., y1 may be 20mm, 50mm, 60mm, or 80mm, etc., and y1' may be 10mm, 30mm, 50mm, or 70mm, etc.

[0113] Fig. 6A The middle frame 300" shown in the figure also includes two protrusions 312" located at the first corner B1 and having a trapezoidal shape. The protrusions 312" are respectively located at the lower left corner and the lower right corner of the first middle plate 320". The size relationship between the edges of the two protrusions 312" and the edge of the hollow frame 311" is the same as that of the protrusion 312" at the upper left corner mentioned above, which will not be repeated here. It can also improve the connection performance at the corner, thereby improving the anti-drop performance of the middle frame 300".

[0114] The following combination Fig. 6A and Figure 6B The other dimensions of the middle frame 300" in this embodiment are further described. It should be noted that the various dimensions of the middle frame provided in this application can be adjusted according to actual needs and are not limited here.

[0115] exist Fig. 6AIn the embodiment, the length x2 of the outer wall of the hollow frame 311" along the x-direction can be in the range of 378.88mm±0.1mm, the length x3 of the first side of the first middle plate 320" extending along the x-direction can be in the range of 243.89mm±0.1mm, the length x4 of the second side of the first middle plate 320" extending along the x-direction can be in the range of 188.85mm±0.1mm, the length x5 of the side of the protrusion 312" at the lower left corner close to the first middle plate 320" and extending along the x-direction can be in the range of 24.18mm±0.1mm, and the protrusion 312" at the lower right corner close to the first middle plate 3 20" and the length x6 of one side extending along the x direction can be in the range of 25.37mm±0.1mm, the length y2 of the outer wall of the hollow frame 311" along the y direction can be in the range of 280mm±0.1mm, the length y3 of the first side 312"a of the protrusion 312" can be in the range of 14.72mm±0.1mm, the length y4 of the third side of the first middle plate 320" extending along the y direction can be in the range of 128.7mm±0.1mm, and the length y5 of the fourth side of the first middle plate 320" extending along the y direction can be in the range of 153.52mm±0.1mm.

[0116] exist Figure 6B In the embodiment, the second side 312"b of the protrusion 312" Fig. 6A )'s length x7 may range from 2.19 mm ± 0.1 mm, and the seam width w (diameter) of the weld structure 330" may be 3.80 mm to 3.82 mm. For example, the seam width w of the weld structure 330" may be 3.80 mm, 3.81 mm or 3.82 mm, and so on.

[0117] The welding method of the middle frame 300" is stir friction welding. The welding paths on the front and back are both clockwise. The welding start position of the front is K1 and the end position is K2 (located at the keyhole). The welding start position of the back is K3 and the end position is K4 (located at the keyhole). The keyhole positions on the front and back are different.

[0118] Specifically, the distance y6 between the starting position K1 and the ending position K2 may be in the range of 31.69 mm±0.1 mm.

[0119] It should be noted that the welding path in the present application can be adjusted according to actual needs, and the keyhole position can be adaptively adjusted according to other structures of the electronic device, so that the keyhole is adapted to the structure of the adjacent electronic device.

[0120] Combine the following Fig. 7A , Figure 7B , Figure 7C , Fig. 8A and Figure 8B The second embodiment of the present application is described in detail.

[0121] Fig. 7A , Figure 7B and Figure 7C The schematic diagram shown is a schematic diagram of the three-dimensional structure, front and back of the middle frame 400; Fig. 8A and Figure 8B The schematic diagram shown is a schematic diagram of the dimensions of the front side of the middle frame 400 and a schematic diagram of the welding path. The middle frame 400 includes a first outer frame 410, a first middle plate 420, a welding seam structure 430 and a keyhole 440 ( Figure 8B ), the first outer frame 410 includes a hollow frame 411 and four protrusions 412.

[0122] The hollow frame 411 may be a rectangular hollow frame, or a rectangular hollow frame with arc-shaped inner wall corners, and the cross section of the protrusion perpendicular to the z direction may be a triangle, or a triangle with arc-shaped corners. The inner wall of the hollow frame 411 has a first corner C1, and the outer wall of the first middle plate 420 has a second corner C2 corresponding to the four first corners C1.

[0123] The weld structures and keyhole positions on the front and back of the middle frame are overlapped, so the shapes and sizes of the front and back of the middle frame are the same. This embodiment only describes the structure and size of the front of the middle frame.

[0124] by Fig. 8A Taking the protrusion 412 in the upper right corner as an example, the protrusion 412 has a first side 412a (the hypotenuse of a right triangle, where the right angle is the corner of the inner wall of the hollow frame 411) intersecting both the x direction and the y direction, the maximum distance from the first side 412a of the protrusion 412 to the first side 411a of the outer side wall of the adjacent hollow frame 411 extending along the y direction is x8, the distance from the first side 411a of the outer side wall of the hollow frame 411 to the inner side wall adjacent thereto is x8', x8 is greater than x8', the maximum distance from the first side 412a of the protrusion 412 to the second side 411b of the outer side wall of the adjacent hollow frame 411 extending along the x direction is y7, and the distance from the second side 411b of the outer side wall of the hollow frame 411 to the inner side wall adjacent thereto is y7', y7 is greater than y7'. Therefore, the protrusion 412 can occupy the corner position of the inner wall of the hollow frame 411, thereby improving the connection performance of the weld structure 430 between the first outer frame 410 and the first middle plate 420 at the corner, and improving the drop resistance and frame strength of the middle frame 400.

[0125] Specifically, the range of x8 can be 20mm-80mm, the range of x8' can be 10mm-70mm, the range of y7 can be 20mm-80mm, and the range of y7' can be 10mm-70mm. For example, x8 can be 20mm, 50mm, 60mm or 80mm, etc., x8' can be 10mm, 30mm, 50mm or 70mm, etc., y7 can be 20mm, 50mm, 60mm or 80mm, etc., and y7' can be 10mm, 30mm, 50mm or 70mm, etc.

[0126] Fig. 8A The middle frame 400 shown in the figure also includes three protrusions 412 located at the first corner C1 and in a triangular shape. The protrusions 412 are respectively located at the upper left corner, the lower left corner and the lower right corner of the first middle plate 420. The size relationship between the edge of the protrusion 412 and the edge of the hollow frame 411 is the same as that of the protrusion 412 at the upper right corner mentioned above, and will not be repeated here. It can also improve the connection performance at the corner to further improve the overall performance of the middle frame 400.

[0127] The following combination Fig. 8A Other dimensions of the middle frame 400 in this embodiment are further described.

[0128] The length x9 of the outer wall of the hollow frame 411 along the x direction may be in the range of 340.00 mm ± 0.10 mm, and the first side of the first middle plate 420 extending along the x direction may have multiple sub-sides with different extension directions, wherein the size x10 and x11 of the two sub-sides closest to the second side 411b of the hollow frame and extending along the x direction may be in the range of: x10 range is 44.60 mm ± 0.10 mm, and x11 range is 44.60 mm ± 0.10 mm. The size x12 of the second side of the first middle plate 420 extending along the x direction may be in the range of 225.87 mm ± 0.10 mm. The length y8 of the outer wall of the hollow frame 411 along the y direction may be in the range of 250.00 mm ± 0.10 mm, and the length y9 of the third side or the fourth side of the first middle plate 420 extending along the y direction may be in the range of 118.85 mm ± 0.10 mm.

[0129] The inner side wall of the hollow frame 411 and the corners of the first middle plate 420 may be sharp or arc-shaped. When the corners are arc-shaped corners, the radius R of the circle where the arc is located may be about 10.00 mm.

[0130] Figure 8B The welding path of the front side of the middle frame 400 is shown. The welding method of the middle frame 400 adopts stir friction welding, and the welding path is counterclockwise. The starting position and the ending position of the welding on the front side are both K5 (located at the keyhole), and the keyhole positions on the front and back sides can be the same.

[0131] Combine the following Fig. 9A , Fig. 9B , Fig. 9C , Fig. 10A , Fig. 10B and Fig. 10C The third embodiment of the present application is described in detail.

[0132] Fig. 9A , Fig. 9B and Fig. 9C The schematic diagrams shown are schematic diagrams of the front, back and side surfaces of the middle frame 500; Fig. 10A , Fig. 10B and Fig. 10C The schematic diagram shown is the welding path and size of the front, back and side of the middle frame 500. Among them, the middle frame 500 includes a first outer frame 510, a first middle plate 520, a weld structure 530 and a keyhole 540, and the first outer frame 510 includes a hollow frame 511 and three protrusions 512. In the front schematic diagram of the middle frame 500, the first middle plate 520 includes a first sub-plate 521 and a second sub-plate 522 arranged at intervals, and a part of the first outer frame 510 is provided between the first sub-plate 521 and the second sub-plate 522, and the surface of this part of the first outer frame 510 serves as the primary appearance surface of the electronic device. In the back schematic diagram of the middle frame 500, the first middle plate 520 is a whole.

[0133] Through the structural design of the above-mentioned middle frame, in addition to setting the protrusion 512 at the corner to improve the anti-drop performance, it is also possible to set a primary appearance surface on the front and design the first middle plate 520 on the back as a whole. That is, two different welding designs are used on the front and back respectively, so that the front side of the middle frame 500 is welded twice and the back side is welded once. Compared with welding twice on both the front and back sides, one welding process is reduced on the back side, thereby improving the welding efficiency.

[0134] The hollow frame 511 is a rectangular hollow frame, and the cross section of the protrusion perpendicular to the z direction can be a rectangle or a trapezoid, or a rectangle or a trapezoid with arc-shaped corners. The inner side wall of the hollow frame 511 has a first corner D1, and the outer side wall of the first middle plate 520 has a second corner D2 corresponding to the three first corners D1.

[0135] Except for the weld structure 530 between the two parts of the middle plate, the other welds on the front and back sides of the middle frame are overlapped, that is, the shapes and sizes of the front and back sides of the middle frame are the same.

[0136] by Fig. 10ATaking the protrusion 512 in the upper right corner as an example, the protrusion 512 has a first edge 512a extending along the y direction, and the distance from the first edge 512a of the protrusion 512 to the first edge 511a of the outer wall of the adjacent hollow frame 511 extending along the y direction is x13, and the distance from the first edge 511a of the outer wall of the hollow frame 511 to the inner wall adjacent to it is x13', and x13 is greater than x13'; similarly, the protrusion 512 has a second edge 512b extending along the x direction, and the distance from the second edge 512b of the protrusion 512 to the second edge 511b of the outer wall of the adjacent hollow frame 511 extending along the x direction is y10, and the distance from the second edge 511b of the outer wall of the hollow frame 511 to the inner wall adjacent to it is y10', and y10 is greater than y10'. Therefore, the protrusion 512 can occupy the corner position of the inner wall of the hollow frame 511, thereby improving the connection performance of the weld structure 530 between the first outer frame 510 and the first middle plate 520 at the corner.

[0137] Specifically, the range of x13 can be 20mm-80mm, the range of x13' can be 10mm-70mm, the range of y10 can be 20mm-80mm, and the range of y10' can be 10mm-70mm. For example, x13 can be 20mm, 50mm, 60mm or 80mm, etc., x13' can be 10mm, 30mm, 50mm or 70mm, etc., y10 can be 20mm, 50mm, 60mm or 80mm, etc., y10' can be 10mm, 30mm, 50mm or 70mm, etc.

[0138] Fig. 10A The middle frame 500 shown in the figure also includes two protrusions 512 located at the first corner D1 and having a trapezoidal shape. The protrusions 512 are respectively located at the lower left corner and the lower right corner of the first middle plate 520. The size relationship between the edges of the two protrusions 512 and the edge of the hollow frame 511 is the same as that of the protrusion 512 at the upper right corner mentioned above, and will not be repeated here.

[0139] The following combination Fig. 10A , Fig. 10B and Fig. 10C Other dimensions of the middle frame 500 in this embodiment are further described.

[0140] exist Fig. 10A, the length x14 of the outer wall of the hollow frame 511 along the x-direction can be in the range of 126.72mm±0.1mm, the length x15 of the first side of the first sub-plate 521 extending along the x-direction (close to the second sub-plate 522) can be in the range of 84.55mm±0.1mm, the length x16 of the first side of the second sub-plate 522 extending along the x-direction (close to the outer wall of the hollow frame 511) can be in the range of 59.87mm±0.1mm, the length y11 of the outer wall of the hollow frame 511 along the y-direction can be in the range of 90.42mm±0.1mm, the length y12 of the second side of the first sub-plate 521 extending along the y-direction can be in the range of 36.3mm±0.1mm, the length y13 of the second side of the second sub-plate 522 extending along the y-direction can be in the range of 3.43mm±0.1mm, and the length y15 of the third side of the first sub-plate 521 extending along the y-direction can be in the range of 27.46mm±0.1mm.

[0141] exist Fig. 10B In the embodiment, the length x17 of the first side of the first middle plate 520 extending along the x direction on the back of the middle frame can be in the range of 69.96 mm ± 0.1 mm, the maximum length x18 of the first middle plate 520 along the x direction can be in the range of 87.85 mm ± 0.1 mm, and the second side 512b ( Fig. 10A ) may be in the range of 11.29 mm ± 0.1 mm, and the length x20 of the side of the lower protrusion 512 extending along the x direction and close to the first middle plate 520 may be in the range of 8.55 mm ± 0.1 mm. The length y16 of the second side of the first middle plate 520 extending along the y direction at the back may be in the range of 49.7 mm ± 0.1 mm, and the length y17 of the third side of the first middle plate 520 extending along the y direction at the back may be in the range of 40.85 mm ± 0.1 mm, and the length y18 of the first side 512a of the protrusion 512 ( Fig. 10A ) can range from 5.54mm±0.1mm.

[0142] exist Fig. 10C The length y19 (the distance between the first sub-plate 521 and the second sub-plate 522) of the primary appearance surface (the portion of the hollow frame 511 located between the first sub-plate 521 and the second sub-plate 522) along the y direction can be in the range of 15.00mm±0.1mm, the thickness z1 of the hollow frame portion where the primary appearance surface is located along the z direction can be in the range of 8.00mm±0.1mm, and the thickness z2 of the first middle plate 520 adjacent to the primary appearance surface along the z direction can be in the range of 2.00mm±0.1mm.

[0143] The welding method of the middle frame 500 adopts stir friction welding, and the welding paths of the front and back are both clockwise, and the first sub-plate 521 and the second sub-plate 522 on the front are welded separately, and the back is welded once. The welding starting position of the first sub-plate 521 is K6 and the ending position is K7 (located at the keyhole), the welding starting position and ending position of the second sub-plate 522 are both K8 (located at the keyhole), the welding starting position of the back is K9 and the ending position is K10 (located at the keyhole), and the keyhole positions on the front and back are different.

[0144] Specifically, the distance y14 between the starting position K6 and the ending position K7 may be in the range of 7.25 mm±0.1 mm.

[0145] Combine the following Fig.11A , Fig. 11B , Fig. 11C , Fig. 12A , Fig. 12B and Fig. 12C The fourth embodiment of the present application is described in detail.

[0146] Fig.11A , Fig. 11B and Fig. 11C The schematic diagram shown is a schematic diagram of the three-dimensional structure, front and back of the middle frame 600; Fig. 12A , Fig. 12B and Fig. 12C The schematic diagram shown is a welding path and size of the front and back of the middle frame 600. The middle frame 600 includes a first outer frame 610, a first middle plate 620, a welding seam structure 630 and a keyhole 640 ( Fig. 12B ), the first outer frame 610 includes a hollow frame 611 and four protrusions 612.

[0147] This embodiment is the same as the third embodiment. The front side of the first middle plate 620 also includes the first sub-plate 621 and the second sub-plate 622, and the back side is a whole middle plate. Its functions and effects are the same and will not be described in detail here.

[0148] The hollow frame is a rectangular hollow frame, or a rectangular frame with arc-shaped inner wall corners, and the cross section of the protrusion perpendicular to the z direction is a triangle, or a triangle with arc-shaped corners. The inner wall of the hollow frame 611 has a first corner E1, and the outer wall of the first middle plate 620 has a second corner E2 corresponding to the four first corners E1.

[0149] by Fig. 12ATaking the protrusion 612 in the upper right corner as an example, the protrusion 612 has a first side 612a (the hypotenuse of a right triangle) intersecting both the x-direction and the y-direction, the maximum distance from the first side 612a of the protrusion 612 to the first side 611a of the outer side wall of the adjacent hollow frame 611 extending along the y-direction is x21, the distance from the first side 611a of the outer side wall of the hollow frame 611 to the inner side wall adjacent thereto is x21', x21 is greater than x21', the maximum distance from the first side 612a of the protrusion 612 to the second side 611b of the outer side wall of the adjacent hollow frame 611 extending along the x-direction is y20, the distance from the second side 611b of the outer side wall of the hollow frame 611 to the inner side wall adjacent thereto is y20', y20 is greater than y20'. Therefore, the protrusion 612 can occupy the corner position of the inner side wall of the hollow frame 611 to improve the anti-drop performance of the middle frame 600.

[0150] Specifically, the range of x21 may be 20mm-80mm, the range of x21' may be 10mm-70mm, the range of y20 may be 20mm-80mm, and the range of y20' may be 10mm-70mm. For example, x21 may be 20mm, 50mm, 60mm or 80mm, etc., x21' may be 10mm, 30mm, 50mm or 70mm, etc., y20 may be 20mm, 50mm, 60mm or 80mm, etc., y20' may be 10mm, 30mm, 50mm or 70mm, etc.

[0151] Fig. 12A The middle frame 600 shown in the figure further includes three protrusions 612 located at the first corner E1 and having a triangular shape. The size relationship between the edges of the three protrusions 612 and the edge of the hollow frame 611 is the same as that of the above-mentioned protrusions, which will not be repeated here.

[0152] The following combination Fig. 12A and Fig. 12C Other dimensions of the middle frame 600 in this embodiment are further described.

[0153] exist Fig. 12A, the length x22 of the outer wall of the hollow frame 611 along the x-direction can range from 340.00mm±0.1mm, the length x23 of the first edge of the first sub-plate 621 extending along the x-direction (close to the second sub-plate 622) can range from 247.80mm±0.1mm, the second edge of the first sub-plate 621 extending along the x-direction (close to the outer wall of the hollow frame 511) has multiple sub-edges with different extension directions, wherein the size ranges of the two sub-edges x24 and x26 closest to the second edge 611b of the hollow frame and extending along the x-direction can be: x24 ranges from 139.7mm±0.10mm, x26 ranges from 19.10mm±0.10mm, and the size x25 of the edge farthest from the second edge 611b of the hollow frame 611 (the recessed portion in the second edge of the hollow frame 611) of the second edge extending along the x-direction of the first sub-plate 621 can range from 12.78mm±0.10mm. The length x27 of the first side (close to the first sub-board 621) of the second sub-board 622 extending along the x direction may be in the range of 238.2 mm ± 0.1 mm, and the length x28 of the second side (close to the outer wall of the hollow frame 611) of the second sub-board 622 extending along the x direction may be in the range of 198.88 mm ± 0.1 mm. The length y21 of the third side of the first sub-board 621 extending along the y direction may be in the range of 124.95 mm ± 0.1 mm, the length y22 of the fourth side of the first sub-board 621 extending along the y direction may be in the range of 80.32 mm ± 0.1 mm, and the maximum dimension y23 of the second sub-board 622 along the y direction may be in the range of 33.95 mm ± 0.1 mm.

[0154] The side cross-sectional view of the middle frame in this embodiment is similar to the above Fig. 10C The schematic diagram is similar to that shown in Fig. 10C And the corresponding text description will not be repeated here.

[0155] Each corner of the inner wall of the hollow frame 611 and the first middle plate 620 may be sharp or arc-shaped. When the corner is an arc-shaped corner, the radius R of the circle where the arc is located may be approximately 10.00 mm.

[0156] exist Fig. 12B In the figure, the welding method of the middle frame 600 adopts stir friction welding, and the welding paths of the front and back are both counterclockwise, and the first sub-plate 621 and the second sub-plate 622 of the front are welded separately, and the back is welded as a whole once. The welding starting position and ending position of the first sub-plate 621 are both K11 (located at the keyhole), the welding starting position and ending position of the second sub-plate 622 are both K12 (located at the keyhole), and the welding starting position and ending position of the back are also K12 (located at the keyhole), which coincides with the front.

[0157] Combine the following Fig.13The sizes of the middle frames in some other embodiments of the present application are described.

[0158] Fig.13 The schematic diagram shown is a cross-sectional schematic diagram of the middle frame 700 perpendicular to the thickness direction. The middle frame 700 includes a first outer frame 710, a first middle plate 720, and a weld structure 730. The first outer frame 710 includes a hollow frame, and the first outer frame 710 may also include one or more protrusions (not shown).

[0159] The hollow frame is a rectangular hollow frame with an inner wall having an arc-shaped corner, and the first middle plate 720 is a rectangular middle plate with an outer wall having an arc-shaped corner.

[0160] The relevant dimensions of the middle frame 700 are as follows: Fig.13 As shown, the maximum dimension x29 of the outer side wall of the first outer frame 710 extending along the x direction may be in the range of 75 mm ± 0.5 mm; the maximum dimension y24 of the outer side wall of the first outer frame 710 extending along the y direction may be in the range of 160 mm ± 0.5 mm; the maximum dimension x30 of the outer side wall of the first middle plate 720 extending along the x direction may be in the range of 55 mm ± 0.5 mm; the maximum dimension y25 of the outer side wall of the first middle plate 720 extending along the y direction may be in the range of 140 mm ± 0.5 mm;

[0161] The protrusions in the middle frame 700 can be set at the corners of the inner sidewalls of the hollow frame, wherein the number and shape of the protrusions can refer to the above embodiment and will not be repeated here. It should be noted that the shape and size of the protrusions can be adaptively adjusted according to the relevant dimensions of other structures of the middle frame 700, thereby improving the anti-drop performance and overall strength of the middle frame 700.

[0162] The following is a detailed description of the method for preparing the middle frame described in the above embodiment of the present application. It should be noted that the following preparation method is only one of the preparation methods of the middle frame of the present application, so as to obtain a first outer frame with a protruding portion and a first middle plate with a corresponding recessed portion. Those skilled in the art may also use other methods to prepare the middle frame provided by the present application, which is not limited here.

[0163] like Fig.14 As shown, the method for preparing the middle frame includes:

[0164] Step S2: providing initial outer frame material and initial middle plate material.

[0165] Step S4: welding the initial outer frame material and the initial middle plate material to obtain a first initial middle frame including a first outer frame material, a first middle plate material and a weld structure therebetween.

[0166] Step S6: processing the appearance of the first initial middle frame to obtain a second initial middle frame with a preset appearance.

[0167] Step S8: performing micro-arc oxidation on the second initial middle frame to form a ceramic layer on the surface of the second initial middle frame to obtain a third initial middle frame.

[0168] Step S10: Anodize the third initial middle frame to form an oxide layer on the surface of the third initial middle frame to obtain a target middle frame (the middle frame described in the above embodiment of the present application), wherein the target middle frame includes a first outer frame, a first middle plate, and a weld structure between the first outer frame and the first middle plate.

[0169] Step S2 also includes:

[0170] Step S22: Preliminary cutting and processing of the large pieces of outer frame raw materials and the middle plate raw materials to obtain initial outer frame materials and initial middle plate materials, wherein the initial outer frame materials can be formed into materials with a hollow frame structure by extruding a plate or extruding a tube. The initial outer frame material includes an initial hollow frame and an initial protrusion located at at least one corner of the inner side wall of the initial hollow frame, and the outer side wall corner of the initial middle plate material has an initial recess corresponding to the initial protrusion.

[0171] Step S4 also includes:

[0172] Step S42: nesting the initial middle plate material into the initial outer frame material.

[0173] Specifically, the distance between the initial middle plate material and the inner side wall of the initial outer frame material does not exceed 0.1 mm.

[0174] Step S44: welding the initial middle plate material and the initial outer frame material according to a preset welding path, thereby obtaining a first initial middle frame including a first outer frame material, a first middle plate material and a weld structure therebetween.

[0175] Specifically, the welding method adopts stir friction welding.

[0176] Step S46: mechanically shaping the first initial middle frame.

[0177] Step S6 also includes:

[0178] Step S62: After welding is completed, the first initial middle frame is processed by computer numerical control (CNC) to adjust the appearance of the first initial middle frame to obtain a second initial middle frame. The preset appearance can be set according to the design requirements of the whole machine.

[0179] In step S8, during the micro-arc oxidation process, the metal of the middle frame reacts strongly with oxygen ions and electrolyte ions under the combined action of thermochemistry, electrochemistry and plasma chemistry, undergoes melting, eruption, crystallization and high-temperature phase change, and finally melts and sinters on the crystal surface inside the middle frame to form a ceramic layer. In other embodiments, step S8 may also adopt a passivation method.

[0180] Step S10 also includes:

[0181] Step S102: forming a shielding layer on the surface of the first middle plate material, and grinding and polishing the surface of the first outer frame material.

[0182] Specifically, forming the shielding layer includes spraying a layer of ink on the surface of the first middle plate material, thereby shielding and protecting the first middle plate material to prevent corrosion during the anodizing process.

[0183] Step S104: placing the third initial middle frame into an anodizing tank for anodizing to form an oxide layer on the surface of the third initial middle frame to form a target middle frame.

[0184] Specifically, the oxide layer may be the anode appearance surface of the target middle frame.

[0185] Step S106: removing the shielding layer.

[0186] Step S108: Mechanically shaping, thermally shaping or laser engraving shaping the target middle frame.

[0187] The middle frame of the above-mentioned embodiment is provided with a protrusion at the corner inside the first outer frame, and the material of the protrusion is used to occupy and replace the original corner position of the edge of the first middle plate, so as to prevent the corner position of the welding connection of the middle frame from being damaged and deformed when it falls or is hit by other external forces, and to avoid the first outer frame and the first middle plate from separating, thereby improving the defects such as deformation or damage of the middle frame under the influence of external forces, and improving the anti-drop performance and overall strength of the middle frame. In addition, in some embodiments, the number of welding times on the front or back of the middle frame is one, that is, one welding can complete the preset path, thereby improving the welding efficiency; in some embodiments, by adopting different welding path designs for the front and back, the number of welding times can be saved, and the welding efficiency can be further improved.

[0188] In an exemplary embodiment, the present application further provides a housing assembly, which includes a housing and the middle frame involved in the above embodiment, and the housing and the middle frame together enclose a receiving cavity of the electronic device. The above housing assembly can resist defects such as deformation or damage under the influence of external forces, thereby improving its own anti-drop performance and overall strength.

[0189] In an exemplary embodiment, the present application further provides an electronic device, which includes a housing and the middle frame involved in the above embodiment, and the housing and the middle frame together enclose a receiving cavity of the electronic device. The above electronic device can reduce weight while improving its own anti-drop performance, thereby improving the overall strength of the electronic device.

[0190] Fig.15 A schematic diagram of an electronic device 100 is shown. The electronic device 100 may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc.

[0191] It is to be understood that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the electronic device 100. In other embodiments of the present application, the electronic device 100 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0192] It should be noted that, in the examples and description of the present application, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "comprise one" do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0193] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present application.

Claims

1. A middle frame, characterized in that: It includes a first outer frame, a first middle plate and a welding structure between the first outer frame and the first middle plate, the first outer frame surrounds the outer side wall of the first middle plate, and the first outer frame and the first middle plate are connected by the welding structure; wherein, The first outer frame includes a hollow frame and a protrusion, the protrusion is located at at least one first corner of the inner wall of the hollow frame, and at least one second corner of the first middle plate has a recessed portion corresponding to the protrusion of the first outer frame, and the material strength of the protrusion is greater than the material strength of the first middle plate.

2. The middle frame according to claim 1, characterized in that: The hollow frame and the protruding portion are an integrally formed structure, and both the hollow frame and the protruding portion are made of a first material, and the first middle plate is made of a second material, wherein the material strength of the first material is greater than the material strength of the second material.

3. The middle frame according to claim 1, characterized in that: The hollow frame is made of a first material, the first middle plate is made of a second material, and the protruding portion is made of a third material, wherein the material strength of the first material and the material strength of the third material are both greater than the material strength of the second material.

4. The middle frame according to any one of claims 1 to 3, characterized in that: The hollow frame includes at least one of a rectangular hollow frame, a triangular hollow frame, a pentagonal hollow frame, and a hexagonal hollow frame.

5. The middle frame according to any one of claims 1 to 3, characterized in that: The first corner is sharp or arc-shaped, and / or the second corner is sharp or arc-shaped.

6. The middle frame according to any one of claims 1 to 3, characterized in that: The first middle plate includes a first sub-plate and a second sub-plate that are spaced apart from each other, a portion of the first outer frame is disposed between the first sub-plate and the second sub-plate, and the second corner includes at least one of a corner of an outer wall of the first sub-plate and a corner of an outer wall of the second sub-plate.

7. The middle frame according to any one of claims 1 to 3, characterized in that: The cross-sectional shape of the protrusion perpendicular to the thickness direction thereof includes at least one of a rectangle, a square, a triangle, a trapezoid, a circle, a step shape, and an L shape.

8. The middle frame according to claim 7, characterized in that: The shapes of different protrusions in the same middle frame are the same or different.

9. The middle frame according to any one of claims 1 to 3, characterized in that: The material of the first outer frame includes aluminum alloy, and the material of the first middle plate includes magnesium alloy.

10. The middle frame according to any one of claims 1 to 3, characterized in that: The weld structure comprises a friction stir weld structure.

11. The middle frame according to claim 10, characterized in that: The middle frame further includes a key hole, and the key hole is arranged on the first middle plate.

12. A housing assembly, characterized in that: The shell assembly comprises a shell and a middle frame according to any one of claims 1 to 11, and the shell and the middle frame together enclose a receiving cavity of the electronic device.

13. An electronic device, characterized in that: It comprises a shell and the middle frame according to any one of claims 1 to 11, wherein the shell and the middle frame together enclose a receiving cavity of the electronic device.

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