Welding fixture, welding device and welding method for mobile phone battery heat insulation sheet

Abstract

The application relates to the technical field of laser welding, and discloses a welding jig, a welding device and a mobile phone battery plate welding method. The welding jig comprises a plurality of pressing blocks, the plurality of pressing blocks are spliced and pressed together to press the welding surface of the sheet-shaped product; all the welding hollowed-out areas of the plurality of pressing blocks arranged after splicing are arranged along the welding path of the sheet-shaped product; the splicing positions of the plurality of pressing blocks are all provided with first gaps; an outer frame is used for confining the plurality of pressing blocks, the outer frame is provided with a limiting groove, the limiting groove has a groove opening facing the pressing blocks; a ball holder is confined in the limiting groove; a ball is confined in the ball holder and can rotate freely; a partial contour of the ball extends from the groove opening; and the pressing blocks have second gaps with the partial contour in a static state. The welding jig can adaptively absorb random deformation of incoming materials of the sheet-shaped product when the sheet-shaped product is pressed, so that the flatness of the welding surface meets the precision requirement of laser welding, and the batch welding yield is improved.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, specifically to a welding fixture, welding equipment, and welding method for a mobile phone battery heat shield for high-precision laser welding. Background Technology

[0002] In smartphone design, battery thermal insulation sheets need to be laser-welded to achieve a sealed connection with the battery casing or motherboard to prevent thermal runaway and ensure electromagnetic shielding effectiveness. Due to the highly compact internal space of mobile phones (assembly gaps are typically ≤0.3mm) and the extremely small diameter of the laser welding spot (approximately 0.1-0.2mm), the flatness of the welding interface needs to approach optical mirror-level precision (generally required to be ≤ ±0.03mm).

[0003] However, the following technical difficulties exist in actual production: ultra-thin aluminum heat insulation sheets (0.1-0.2mm) are prone to micron-level warping during stamping and transportation. Furthermore, due to the low yield strength of aluminum, conventional vacuum adsorption or rigid pressure plate fixtures cannot adaptively compensate for the random warping (such as S-shaped or wavy deformation) of the incoming heat insulation sheet material, resulting in a residual flatness deviation of >0.1mm after pressing.

[0004] Adding flexible silicone pads to the surface of the fixture can alleviate local pressure concentration, but the silicone hardens or adheres after being heated and aged, resulting in a decrease in flatness stability during continuous production. Summary of the Invention

[0005] Therefore, the purpose of this invention is to overcome the problem of defective laser welds caused by the inability of existing technologies to adaptively compensate for random warping of incoming sheet products. This invention provides a welding fixture, welding equipment, and welding method for heat insulation sheets of mobile phone batteries for high-precision laser welding processes. When the welding fixture presses the sheet product, it adaptively absorbs the random deformation of the incoming sheet product, so that the flatness of the welding surface meets the laser welding precision requirements and improves the yield of batch welding.

[0006] In a first aspect, to solve the above-mentioned technical problems, the present invention provides a welding fixture for pressing and fitting sheet-like products to be welded, comprising,

[0007] Multiple pressure blocks are spliced ​​together and pressed onto the welding surface of the sheet-like product; each pressure block has a welding perforation area, and all the welding perforation areas of the spliced ​​multiple pressure blocks are arranged along the welding path of the sheet-like product; wherein, a first gap is provided at the splicing point of each of the multiple pressure blocks;

[0008] The outer frame, in which the plurality of pressure blocks are constrained, has a limiting groove on the outer frame, the limiting groove having an opening facing the pressure block;

[0009] The ball holder is constrained within the limiting groove;

[0010] A sphere, constrained within the sphere frame and free to rotate; a portion of the sphere's outline extends from the slot;

[0011] The pressure block has a second gap with the local contour when it is static.

[0012] In one embodiment of the present invention, the second gap is 0.01mm to 0.03mm.

[0013] In one embodiment of the present invention, the limiting groove has a spherical surface on its groove wall that connects with the groove opening, and the sphere is in surface contact with the spherical surface; and the limiting groove has a flat bottom wall that faces the groove opening, and the sphere is in point contact with the flat surface.

[0014] In one embodiment of the present invention, the ball frame includes a plate with an assembly hole, and the ball passes through the assembly hole; a guide block is provided on the plate around the assembly hole, and the ball passing through the assembly hole is supported by the guide block; wherein the supporting surface of the guide block and the outline of the ball in contact with it are similar.

[0015] In one embodiment of the invention, the end of the pressing block extends a side arm toward the direction in which it presses the sheet-like product, and the pressing block contacts the partial contour of the sphere through the side arm in a dynamic manner.

[0016] In one embodiment of the invention, the side arm extends toward the outer frame with a lug, the lug pressing against the limiting groove to constrain the ball frame.

[0017] In one embodiment of the invention, a pressure cap is further included, which presses against the lugs of all the pressing blocks to constrain all the pressing blocks; wherein a floating mechanism is connected between the pressure cap and each of the lugs, the floating mechanism supporting the pressing blocks to float along the direction in which they press the sheet-like product.

[0018] In one embodiment of the present invention, the floating mechanism includes a guide rod and a helical spring; the lug is provided with a recessed hole on the surface of its connecting cover, the guide rod is located in the recessed hole and connected to the lug, and the helical spring passes through the guide rod and abuts against the bottom wall of the recessed hole and the cover at both ends respectively.

[0019] In one embodiment of the present invention, the surface of the pressed sheet product is provided with a plurality of raised strips, the plurality of raised strips are arranged at intervals along the welding path, the raised strips are arranged to avoid the welding hollow area, and the raised strips are provided on both sides of the welding hollow area along the welding path direction.

[0020] In one embodiment of the invention, a stage is further included, the stage being connected to the outer frame to form a welding position for accommodating the sheet-like product, the sheet-like product being positioned and adsorbed onto the welding position.

[0021] Secondly, to solve the above-mentioned technical problems, the present invention provides a welding device, including the aforementioned welding fixture.

[0022] Thirdly, to solve the above-mentioned technical problems, the present invention provides a method for welding a heat insulation sheet for a mobile phone battery, using the aforementioned welding fixture. The method includes...

[0023] Step 1: The battery heat insulation sheet is placed in the welding position of the welding fixture and positioned; wherein the welding surface of the battery heat insulation sheet is exposed;

[0024] Step 2: All the pressing blocks are simultaneously pressed onto the welding surface of the battery heat insulation sheet;

[0025] Step 3: The battery heat insulation sheet is pressed until the flatness of the welding surface meets the requirements;

[0026] Step 4: Adsorb and fix the battery heat insulation sheet;

[0027] Step 5: Weld the weld points on the welding surface through the welding cutout area;

[0028] When the battery heat insulation sheet has a deformed area that makes the flatness of the welding surface not meet the requirements, the pressure block floats through the first gap and / or the second gap to flatten the deformed area, so that the flatness of the welding surface meets the requirements.

[0029] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0030] The welding fixture, welding equipment, and welding method for mobile phone battery heat insulation sheets described in this invention adaptively absorb the random deformation of the incoming sheet product when the welding fixture presses the sheet product, and controls the flatness of the welding surface within ±0.03mm under zero plastic deformation conditions, which is suitable for the high-precision welding requirements of ultra-thin aluminum materials, thereby improving the batch welding yield. Attached Figure Description

[0031] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0032] Figure 1 This is a schematic diagram of the welding fixture in a preferred embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of a single pressure block;

[0034] Figure 3 This is a schematic diagram of the structure where two pressure blocks are joined together;

[0035] Figure 4 for Figure 3 A magnified schematic diagram of a local area A in the middle;

[0036] Figure 5 This is a front view of the pressure block, the ball holder, and the ball itself.

[0037] Figure 6 for Figure 1 The schematic diagram of the welding fixture shown below, with the pressure cap removed;

[0038] Figure 7 for Figure 6 A magnified schematic diagram of a local region B in the middle;

[0039] Figure 8 for Figure 1 The diagram shows the outer frame of the welding fixture.

[0040] Figure 9 for Figure 8 A magnified schematic diagram of a local region C in the middle;

[0041] Figure 10 This is an assembly diagram showing the connection between the ball holder and the ball.

[0042] Figure 11 A top view schematic diagram of the structure in which the limiting groove cooperates with the ball frame and the ball;

[0043] Figure 12 A flowchart illustrating the welding method for heat insulation sheets in mobile phone batteries.

[0044] Explanation of reference numerals in the instruction manual:

[0045] 2-Pressure block, 21-Welding hollow area, 22-First gap, 23-Side arm, 24-Lug, 25-Protruding strip;

[0046] Outer frame, 41-limiting groove, 42-groove, 43-simulacral surface;

[0047] 6-Ball frame, 61-Plate body, 62-Assembly hole, 63-Guide block;

[0048] 8-Sphere, 81-Partial outline;

[0049] 10 - Second gap;

[0050] 12-Capping;

[0051] 14-Floating mechanism, 141-Guide rod, 142-Helical spring, 143-Concave hole;

[0052] 16-Platform. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention. Example

[0054] Reference Figures 1-11 As shown, this embodiment of the invention discloses a welding fixture for pressing a sheet-like product to be welded. It includes multiple pressing blocks 2, an outer frame 4, and a platform 16, as well as a floating support structure corresponding to the pressing blocks 2. The floating support structure includes a ball frame 6 and a ball 8. The platform 16 is connected to the outer frame 4 to form a welding position for accommodating the sheet-like product, and the sheet-like product is positioned and adsorbed at the welding position. The plurality of pressure blocks 2 are spliced ​​and pressed together to weld the surface of the sheet-like product; each pressure block 2 is provided with a welding hollow area 21, and all the welding hollow areas 21 of the plurality of pressure blocks 2 after splicing are arranged along the welding path of the sheet-like product; each splice of the plurality of pressure blocks 2 is provided with a first gap 22; the plurality of pressure blocks 2 are constrained within the outer frame 4, and the outer frame 4 is provided with a limiting groove 41, the limiting groove 41 having a slot 42 facing the pressure block; the ball frame 6 is constrained within the limiting groove 41; the ball 8 is constrained within the ball frame 6 and rotates freely; a partial contour 81 of the ball 8 extends from the slot 42; and a second gap exists between the pressure block and the partial contour when static.

[0055] In specific application scenarios, refer to Figure 2 , Figure 3 and Figure 4 As shown, the thickness of the sheet-like product is 0.1-0.2mm, such as a thin aluminum sheet used as a battery heat insulation sheet. The number and shape of the pressure blocks 2 are planned according to the structure and size of the sheet-like product, so that multiple pressure blocks 2 cover the welding surface through splicing, and all welding perforated areas 21 are arranged along the welding path. A first gap 22 is reserved at the splicing point of the pressure blocks 2. When the sheet-like product has warping or other deformations, each pressure block 22 can be slightly shifted or tilted along the splicing seam (i.e., the first gap 22) to match the distribution of the pressing force with the deformation area, avoiding stress concentration caused by overall rigid pressing. Furthermore, as the force-applying component of the welding fixture, the pressure blocks 2 inevitably suffer wear and tear. Multiple pressure blocks 2 are independently set up, allowing for targeted replacement when a part is damaged, reducing the maintenance cost of the welding fixture.

[0056] The welding cutout areas 21 of all pressure blocks 2 are arranged along the laser welding path to ensure that the heat during the welding process is only applied to the target area, reduce the interference of heat conduction on the stability of pressure blocks 2, and at the same time avoid pressure blocks 2 from blocking the laser path.

[0057] Reference Figure 5 , Figure 9 , Figure 10 and Figure 11 As shown, the sphere 8 is constrained in the ball frame 6 within the limiting groove 41. The pressure block 2 statically presses the non-deformable sheet-like product. At this time, there is a second gap 10 between the pressure block 2 and the partial contour 81 of the sphere 8 extending out of the groove 42. When the deformable sheet-like product is pressed, it causes the pressure block 2 to slightly translate or tilt. The second gap 10 allows the pressure block 2 to float and contact the sphere 8. The sphere 8 can rotate freely, converting the vertical pressure on the pressure block 2 into a multi-degree-of-freedom floating support: (1) The rotation of the sphere changes the support height, absorbing deformation to form axial compensation; (2) The contact point between the sphere and the pressure block slides tangentially, offsetting the lateral displacement to form tangential compensation; (3) The low friction of the point contact between the sphere and the pressure block ensures that the bidirectional compensation does not interfere with each other. Compared to the method of absorbing product deformation by reserving gaps, the welding fixture of the present invention, through the cooperation of the second gap 10 and the ball 8, is compatible with products with random deformation (deformation area, degree of deformation, etc. are uncertain); at the same time, the floating support of the ball 8 on the pressure block 2 transforms the concentrated load of the pressure block on the deformation area into uniform contact stress, avoiding plastic deformation of ultra-thin aluminum material.

[0058] In specific application scenarios, the floating support structure consisting of the ball frame 6 and the ball 8 is positioned corresponding to the pressure block 2. One or more can be configured around the end of the pressure block 2, depending on actual needs; one or more can also be configured around the edge of the pressure block 2, matching the shape and size of the product and the size of the fixture.

[0059] The second gap 10 is used to ensure that there is a small gap between the pressure block 2 and the ball 8 when no external clamping force is applied. Preferably, the second gap 10 is set to 0.01mm~0.03mm, which is slightly smaller than the expected deformation (such as warping of 0.05mm). When the external clamping force is applied, the pressure block 2 needs to move 0.01~0.03mm to contact the ball 8, forming a two-stage leveling of "soft contact-hard support": soft contact stage: the pressure block is pressed down freely until the second gap closes, only overcoming the elastic deformation of the aluminum material (stress <10MPa); hard support stage: after the gap closes, the ball 8 provides rigid support by rotation, realizing high-precision planar control.

[0060] The welding fixture described in this invention adaptively absorbs the random deformation of the incoming sheet products when pressing them together, and controls the flatness of the welding surface within ±0.03mm under zero plastic deformation conditions, thus meeting the high-precision welding requirements of ultra-thin aluminum materials and improving the batch welding yield.

[0061] Preferably, refer to Figure 9 and Figure 11As shown, the limiting groove 41 has a spherical surface 43 on its groove wall where it connects with the groove opening 42, and the sphere 8 is in surface contact with the spherical surface 43; and the bottom wall of the limiting groove 41 facing the groove opening 42 is set as a plane, and the sphere 8 is in point contact with the plane. The surface contact between the spherical surface 43 and the sphere 8 forms a geometric conformal constraint, allowing the sphere 8 to rotate around any axis, but restricting its translation, ensuring that the sphere 8 only rotates and does not shift. For example, when the pressure block 2 is subjected to a lateral force, the sphere 8 rotates around the normal of the contact surface, and the spherical surface 43 guides the rotation trajectory, avoiding support instability caused by the sphere 8 shifting. The point contact between the sphere 8 and the bottom wall of the groove opening 42 (theoretical contact area ≈ 0) converts sliding friction into rolling friction, reducing the rotational resistance torque. Thus, through the combined constraint of the surface contact between the sphere 8 and the spherical surface 43 and the point contact between the sphere 8 and the plane, precise guidance and low-friction adaptive motion of the sphere 8 are achieved.

[0062] Reference Figure 10 As shown, the ball holder 6 includes a plate 61 with an assembly hole 62. The ball 8 passes through the assembly hole 62. A guide block 63 is provided around the assembly hole 62 on the plate 61, supporting the ball 8 as it passes through the assembly hole 62. The support surface of the guide block 63 is similar in shape to the outline of the ball it contacts. The similarity between the support surface of the guide block 63 and the outline of the ball forms a fully enclosed contact, restricting the radial displacement of the ball and allowing it to rotate only around its center. The ball 8 passes through the assembly hole 62, the diameter of which is slightly larger than the diameter of the ball, allowing for slight thermal expansion while preventing axial movement of the ball.

[0063] Reference Figure 2 and Figure 5 As shown, the end of the pressure block 2 extends a side arm 23 toward the direction of pressing the sheet-like product. Under dynamic conditions, the pressure block 2 contacts the partial contour 81 of the sphere 8 through the side arm 23. The side arm 23 extends outward from the end of the pressure block 2, forming a cantilever beam structure to absorb the impact energy of pressing and prevent instantaneous overload from being transmitted to the sphere 8. The side arm 23 extends a lug 24 toward the outer frame 4, and the lug 24 presses against the limiting groove 41 to constrain the ball frame 6. Along the direction of pressing the product, the limiting groove 41 is a blind groove with a top opening, facilitating the installation of the ball frame 6 into the groove. The top opening is pressed against by the lug 24 to form a movement constraint on the ball frame 6, thus simplifying the structure and making installation convenient.

[0064] Reference Figure 1 and Figure 7As shown, it also includes a pressure cap 12, which presses against the lugs 24 of all the pressure blocks 2 to constrain all the pressure blocks 2; wherein, a floating mechanism 14 is connected between the pressure cap 12 and each lug 24, and the floating mechanism 14 supports the pressure blocks 2 to float along the direction of pressing the sheet-like product. After the pressure cap 12 is fastened, it provides the main clamping force for pressing the product by the pressure blocks 2, and the floating mechanism 14 provides further floating support along the direction of pressing the product, avoiding indentation defects formed by rigid contact on the product; at the same time, the floating mechanism and the floating support composed of the ball frame 6 and the ball 8 coordinate with each other to promote adaptability to product deformation. Furthermore, the floating mechanism 14 and the floating support composed of the ball frame 6 and the ball 8 work together around the position of the lug 24 on the pressure block 2, simplifying the structure, and the coordinated force transmission path is extremely compressed, resulting in a rapid coordinated response.

[0065] Specifically, refer to Figure 2 and Figure 7 As shown, the floating mechanism 14 includes a guide rod 141 and a helical spring 142; the lug 24 has a recess 143 on the surface of its connecting cover 12, the guide rod 141 is located in the recess 143 and connected to the lug 24, and the helical spring 142 passes through the guide rod 141 and abuts against the bottom wall of the recess 143 and the cover 12 at both ends respectively.

[0066] Furthermore, referring to Figure 5 As shown, the surface of the sheet-like product pressed by the pressure block 2 is provided with several protrusions 25. These protrusions 25 are spaced apart along the welding path, avoiding the welding perforation area 21. The welding perforation area 21 has protrusions 25 on both sides along the welding path. The pressure block 2 contacts and presses the welding surface of the product through these protrusions 25. The spaced protrusions 25 form discrete contact points, evenly distributing the pressing force to the product surface and avoiding stress concentration caused by large-area pressing. The protrusions 25 on both sides of the welding perforation area 21 form a "clamping boundary," suppressing welding heat-induced deformation and reducing the flatness fluctuation of the weld from ±0.1mm to ±0.02mm. Example

[0067] Based on the same inventive concept, embodiments of the present invention provide a welding device, including the aforementioned welding fixture.

[0068] The welding equipment of this invention uses the welding fixture described above and has the same technical effects as the welding fixture, which will not be described in detail here. Example

[0069] Based on the same inventive concept, embodiments of the present invention provide a method for welding a heat insulation sheet for a mobile phone battery, using the aforementioned welding fixture, referring to... Figure 12 As shown, the method includes,

[0070] Step 1: Place the battery heat shield on the welding position of the stage and position it so that the welding surface of the battery heat shield is exposed outwards.

[0071] Step 2: All the pressing blocks are simultaneously pressed onto the welding surface of the battery heat insulation sheet;

[0072] Step 3: The battery heat insulation sheet is pressed until the flatness of the welding surface meets the requirements; wherein, when the battery heat insulation sheet has a deformed area that makes the flatness of the welding surface not meet the requirements, the pressing block floats through the first gap and / or the second gap to flatten the deformed area so that the flatness of the welding surface meets the requirements;

[0073] Step 4: Adsorb and fix the battery heat insulation sheet;

[0074] Step 5: Weld the weld points on the welding surface through the welding cutout area.

[0075] The mobile phone battery heat insulation sheet welding method of this invention uses a welding fixture and utilizes the coordinated floating of the first gap of the pressure block and the second gap of the sphere to absorb the warping of the incoming battery heat insulation sheet, welding thermal deformation, and assembly errors in real time. The final flatness is stabilized within ±0.03mm, meeting the mirror-level precision requirements of laser welding, thereby improving the batch welding yield. Furthermore, the axial compensation (normal height adjustment) and tangential compensation (lateral displacement absorption) of the sphere respond synchronously, covering complex deformations such as S-shapes and wavy shapes.

[0076] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A welding fixture for pressing together sheet-like products to be welded, characterized in that: include, Multiple pressure blocks are spliced ​​together and pressed onto the welding surface of the sheet-like product; each pressure block has a welding perforation area, and all the welding perforation areas of the spliced ​​multiple pressure blocks are arranged along the welding path of the sheet-like product; wherein, a first gap is provided at the splicing point of each of the multiple pressure blocks; The outer frame, in which the plurality of pressure blocks are constrained, has a limiting groove on the outer frame, the limiting groove having an opening facing the pressure block; The ball holder is constrained within the limiting groove; A sphere is constrained within the sphere frame and rotates freely; a portion of the sphere's outline extends from the slot. Wherein, the pressure block has a second gap with the local contour when static; The end of the pressing block extends a side arm toward the direction of pressing the sheet-like product, and the pressing block contacts the partial contour of the sphere through the side arm in dynamic conditions; the side arm extends a lug toward the outer frame, and the lug presses against the limiting groove to constrain the ball frame; It also includes a pressure cap, which presses against the lugs of all the pressing blocks to constrain all the pressing blocks; wherein, a floating mechanism is connected between the pressure cap and each lug, the floating mechanism supporting the pressing blocks to float along the direction of their pressing of the sheet-like product; the floating mechanism includes a guide rod and a helical spring; the lugs have a recessed hole on the surface where they connect to the pressure cap, the guide rod is located in the recessed hole and connects to the lugs, and the helical spring passes through the guide rod and abuts against the bottom wall of the recessed hole and the pressure cap at both ends respectively.

2. The welding fixture according to claim 1, characterized in that: The second gap is 0.01mm~0.03mm.

3. The welding fixture according to claim 1, characterized in that: The limiting groove has a spherical surface on its groove wall that connects to the groove opening, and the sphere is in surface contact with the spherical surface; and the bottom wall of the limiting groove that faces the groove opening is set as a plane, and the sphere is in point contact with the plane.

4. The welding fixture according to claim 1 or 3, characterized in that: The ball frame includes a plate with an assembly hole, through which the ball passes; a guide block is provided around the assembly hole on the plate, and the ball passing through the assembly hole is supported by the guide block; wherein the supporting surface of the guide block and the outline of the ball in contact with it are similar.

5. The welding fixture according to claim 1 or 2, characterized in that: The surface of the pressed sheet product is provided with a plurality of raised strips, which are arranged at intervals along the welding path. The raised strips are set away from the welding hollow area, and the raised strips are provided on both sides of the welding hollow area along the welding path direction.

6. The welding fixture according to claim 1 or 2, characterized in that: It also includes a platform connected to the outer frame to form a welding position for accommodating the sheet-like product, the sheet-like product being positioned and adsorbed at the welding position.

7. A welding device, characterized in that: Includes the welding fixture as described in any one of claims 1-6.

8. A method for welding a heat insulation sheet for a mobile phone battery, characterized in that: Using the welding fixture as described in any one of claims 1-6, the method includes, Step 1: The battery heat insulation sheet is placed in the welding position of the welding fixture and positioned; wherein the welding surface of the battery heat insulation sheet is exposed; Step 2: All the pressing blocks are simultaneously pressed onto the welding surface of the battery heat insulation sheet; Step 3: The battery heat insulation sheet is pressed until the flatness of the welding surface meets the requirements; Step 4: Adsorb and fix the battery heat insulation sheet; Step 5: Weld the weld points on the welding surface through the welding cutout area; When the battery heat insulation sheet has a deformed area that makes the flatness of the welding surface not meet the requirements, the pressure block floats through the first gap and / or the second gap to flatten the deformed area, so that the flatness of the welding surface meets the requirements.

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