A laser welding tooling and method for a thin walled shell

Abstract

The application discloses a laser welding tool and method for a weak shell, which comprises a base, the base is an inner groove structure, and comprises a cavity positioning groove and a cavity fixing pressing plate limiting groove; a cavity is placed on the base and is limited in the cavity positioning groove of the base; the cavity fixing pressing plate comprises a profiling boss structure, and contacts the cavity part outside the welding seam through the profiling boss structure; the cavity fixing pressing plate is installed on the base and is limited in the cavity fixing pressing plate limiting groove; the elbow clamp and the cover plate fixing pressing plate are used; during welding, the cavity is first fixed by the cavity fixing pressing plate, and then the elbow clamp is used to press the cover plate fixing pressing plate to make the cover plate and the cavity keep fixed during the laser continuous welding process, so that the bulging is avoided.

Description

Technical Field

[0001] This invention relates to the technical field of sealing processes in micro-assembly, and specifically to a laser tooling, method, and tooling calibration method for a weak housing. Background Technology

[0002] Currently, due to the rapid advancements in microwave packaging and circuit assembly technologies, various radars are developing towards miniaturization and lightweighting. This necessitates increasingly higher requirements for the small size and light weight of microwave components, while ensuring good hermeticity and packaging strength; in other words, the cavity strength is becoming increasingly weak. To meet these demands, existing technologies employ laser welding, which involves spot welding using a pressure plate and limiting cover, followed by removing the pressure plate and then continuous sealing welding. However, laser sealing welding relies on a high-energy laser beam to melt the welded area. When conventional welding fixtures are used when the welded cavity is weak, the cavity will deform, affecting the welding and bonding strength of the internal components.

[0003] Patent application CN202011156341.X discloses a three-dimensional simulation machining fixture and method for irregularly shaped thin-walled stainless steel parts. It includes a large-surface inner cavity machining fixture for clamping and machining the large end face and U-shaped inner cavity of the blank; and a small-surface outer shape machining fixture for clamping and machining the small end face of the blank. The small-surface outer shape machining fixture cooperates with a clamping cover plate for pressing the blank. This fixture can be used for auxiliary machining of pipe-type thin-walled parts, enabling curved surface machining and improving machining quality and efficiency.

[0004] Patent application CN201811573660.3 discloses a welding method and welding fixture for welding a titanium alloy sheet with through holes to a butt joint. The fixture includes a base, a fixture pressure plate, at least two positioning posts, and at least two fixing members. The base is a cylindrical structure open at both ends, with an inner cavity containing a mounting plate. The first end of each positioning post is fixed to the mounting plate, and the second end of each positioning post has a positioning hole. The fixture pressure plate is fixedly connected to the mounting plate via at least two fixing members. During welding, the first ends of at least two butt joints are each inserted into a positioning hole, and the second ends of at least two butt joints are aligned with the through holes on the titanium alloy sheet. The fixture pressure plate is then pressed onto the titanium alloy sheet, and the sheet is tightened and fixed by the at least two fixing members. The thermal conductivity of the fixture pressure plate is greater than that of the titanium alloy sheet. This method ensures weld penetration and precise forming, guaranteeing a weld penetration of 0.6 mm and a smooth weld joint with no deformation in any part. Both patent applications disclose welding methods for thin plate tooling, but they do not offer an effective technical solution to ensure that the welded cavity and the cover plate do not deform simultaneously during the welding process.

[0005] This application mainly targets laser welding of weak cavities. This process technology solves the problem in the existing technology that the welded cavity will deform, thus affecting the welding and bonding strength of the internal components. It also has the following advantages: it can ensure that the welded cavity does not deform; it can ensure that the welded cover plate does not bulge; it can ensure the long-term stable use of the tooling; it can shorten the welding time; it can shorten the tooling assembly time; and it is convenient for manual operation. Summary of the Invention

[0006] The present invention aims to address the aforementioned problems by providing a laser welding fixture and method for weak shells. The fixture includes a base with an internal groove structure, comprising a cavity positioning groove and a cavity fixing plate limiting groove. A cavity is placed on the base and confined within the cavity positioning groove. The fixture also includes a cavity fixing plate, which includes a contoured boss structure that contacts the cavity portion outside the weld seam. The cavity fixing plate is mounted on the base and confined within the cavity fixing plate limiting groove. Finally, the fixture includes an elbow clamp and a cover plate fixing plate. During welding, the cavity is first individually fixed by the cavity fixing plate, and then the elbow clamp presses down on the cover plate fixing plate to maintain both the cover plate and the cavity in a fixed state during continuous laser welding, thereby preventing bulging.

[0007] The technical solution adopted in this invention is as follows:

[0008] This invention discloses a laser welding fixture for weak shells, including a base with an internal groove structure, comprising a cavity positioning groove and a cavity fixing plate limiting groove. A cavity is placed on the base and is limited within the cavity positioning groove of the base. The fixture also includes a cavity fixing plate, which includes a contoured boss structure that contacts the cavity portion outside the weld seam. The cavity fixing plate is mounted on the base and limited within the cavity fixing plate limiting groove. During welding, the cavity fixing plate is pressed down by an elbow clamp to keep the cavity in a fixed state throughout the laser welding process, thus achieving the purpose of preventing deformation.

[0009] Furthermore, the base includes an elbow clamp and a cover plate fixing plate. The base includes a cover plate fixing plate limiting groove. The cover plate fixing plate is installed on the cavity fixing plate and limited in the cover plate fixing plate limiting groove. The cover plate fixing plate is configured as a contour structure and contacts the entire cover plate surface of the base. The elbow clamp presses the cover plate fixing plate, and welding is performed by pressing and fixing the fixture with the elbow clamp. During welding, the cavity is first fixed separately by the cavity fixing plate, and then the cover plate fixing plate is pressed down by the elbow clamp so that the cover plate and the cavity remain fixed in a fixed state during the continuous laser welding process, thereby achieving the purpose of preventing bulging.

[0010] Furthermore, it includes a base, an elbow clamp, a cavity fixing plate, and a cover plate fixing plate. The base has an inner groove-shaped structure, and threaded holes are provided on both sides of the inner groove-shaped structure to connect the elbow clamp. The elbow clamp presses the cavity fixing plate and the cover plate fixing plate to fix the welded cavity. When switching cavities, the elbow clamp releases the cavity fixing plate and the cover plate fixing plate.

[0011] Furthermore, it includes an elbow clamp separately pressing cavity fixing pressure plate, and an elbow clamp separately pressing cover plate fixing pressure plate.

[0012] Furthermore, it includes a soft gasket, which is disposed on the bottom surface of the cover plate fixing plate.

[0013] Furthermore, during welding, the elbow clamp fixes the cavity to be welded by pressing the pressure plate, and the elbow clamp releases the pressure plate when switching cavities.

[0014] This invention discloses a method for laser welding fixtures for weak shells, including a base, an elbow clamp, a cavity fixing plate, and a cover plate fixing plate, employing a continuous laser welding method, comprising the following steps:

[0015] S1: Assemble the base, cavity, cavity fixing plate and cover plate fixing plate to form a welding fixture. Then, use elbow clamps to press the cavity fixing plate and cover plate fixing plate respectively to fix the cavity fixing plate and cover plate fixing plate separately.

[0016] S2: Use the cover plate to fix the pressure plate of the base to fix the cover plate. After fixing, perform the first welding of the weld by continuously laser welding more than 50% of the area.

[0017] S3: Remove the cover plate fixing plate. When only the cavity fixing plate is used to press the cavity, directly use continuous laser welding to weld the remaining area after the first welding to complete the secondary welding of the weld.

[0018] Furthermore, it includes a cover plate fixing pressure plate, which is reduced in size in the portion crossing the weld seam to increase the continuous weld seam area of ​​the first weld and increase the cover plate being pressed and fixed during welding within the welding range.

[0019] Furthermore, unlike the method of "fixing the cover plate with a pressure plate by dotting it and then continuously welding it after removing the cover plate and fixing the pressure plate", its characteristic is that "the pressure plate is used to fix the cover plate and continuously weld most of the area, and then the cover plate is removed and the pressure plate is fixed and continuously welded to the remaining part".

[0020] This invention discloses an inspection method for laser welding fixtures used on weak shells, comprising a base, a cavity fixing plate, and a cover plate fixing plate. During operation, the cavity, cavity fixing plate, and cover plate fixing plate are installed into the base to complete the assembly, including the following steps:

[0021] S1: Set the calibration ruler to be placed between the cavity and the wall fixing plate, or between the cover plate and the cover plate fixing plate, and press the cavity fixing plate and the cover plate fixing plate respectively with the elbow clamp.

[0022] S2: Pull out the calibration ruler. If the calibration ruler can be pulled out, it means that the clamping force of the welding fixture is insufficient and needs to be adjusted. Use the calibration ruler to check the gap between the cover plate fixing plate and the cover plate, and check the gap between the cavity fixing plate and the cavity.

[0023] Furthermore, during the inspection process, the clamping force at the four corners and the center of the cavity fixing plate and the cover plate fixing plate was tested using a calibration ruler.

[0024] Furthermore, the inspection process uses calibration plates to check the gap between the cover plate fixing plate and the cover plate, and to check the gap between the cavity fixing plate and the cavity, in order to ensure that the cover plate fixing plate and the wall fixing plate are working properly.

[0025] The technical effects of this invention are as follows:

[0026] This invention discloses a laser welding fixture and method for weak shells. Compared with the laser welding fixtures used in the prior art, a pressure plate is used to fix the cavity to prevent deformation during the entire continuous welding process. A pressure plate is also used to fix the cover plate to prevent bulging during the continuous welding process. The cavity and the cover plate are fixed separately to meet the stability of mass production. The laser dotting process is eliminated and an elbow clamp is used to shorten the clamping time and achieve convenient operation.

[0027] Specifically as follows:

[0028] 1. This invention discloses a laser welding fixture for a weak cavity. During welding, the cavity is first fixed separately by a cavity fixing plate, and then the cover plate is fixed by pressing down with an elbow clamp to keep the cover plate and the cavity fixed during continuous laser welding, thereby preventing bulging. This solves the problem that deformation during the welding of the weak cavity affects the welding and bonding strength, and solves the problem that bulging deformation of the weak cover plate after welding affects the weld bonding strength, leading to bulging of the cover plate and cracking of the weld.

[0029] 2. This invention discloses a method for laser welding fixtures for weak cavities to improve welding efficiency.

[0030] 3. This invention discloses an inspection method for laser welding fixtures with weak cavities, so as to ensure the long-term stable operation of the welding fixtures through the simplest and most effective means.

[0031] 4. This invention discloses a laser welding fixture that can be quickly clamped and mounted to reduce manual operation and improve welding efficiency. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of existing laser welding fixtures;

[0033] Figure 2 This is a schematic diagram of the laser welding fixture of the present invention;

[0034] Figure 3 This is a schematic diagram of the base structure of the laser welding fixture of the present invention;

[0035] Figure 4 This is a schematic diagram of the laser welding fixture cover plate fixing pressure plate structure of the present invention;

[0036] Figure 5 This is a schematic diagram of the laser welding tooling cavity fixing pressure plate structure of the present invention;

[0037] Figure 6 This is a schematic diagram of the laser welding fixture calibration ruler of the present invention;

[0038] The markings in the diagram are: 1-base, 2-elbow clamp, 3-cavity fixing plate, 4-cover plate fixing plate, 5-calibration ruler. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings.

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] The data used in this embodiment is a preferred solution, but it is not intended to limit the present invention.

[0042] Throughout the laser welding process, pressure plates, bars, blocks, or other mechanisms are used to press the cavity being welded.

[0043] In this embodiment, the housing includes a combination structure of a cavity and a cover plate.

[0044] Example 1

[0045] like Figure 2 , 3 As shown in Figure 5, this embodiment provides a laser welding fixture for a weak shell, including a base. The base has an inner groove structure, including a cavity positioning groove and a cavity fixing plate limiting groove. A cavity is placed on the base, and the cavity is limited within the cavity positioning groove of the base. The fixture also includes a cavity fixing plate, which includes a contoured boss structure that contacts the cavity portion outside the weld seam. The cavity fixing plate is mounted on the base and limited within the cavity fixing plate limiting groove.

[0046] In this embodiment, during operation, the cover plate is pressed and fixed by an elbow clamp, preferably by screws or other locking methods to fix the cavity, and the cavity is kept in a pressed and fixed state throughout the entire laser welding process.

[0047] Preferably, the bottom surface of the cavity fixing plate has a 0.5mm thick boss that contacts the cavity. Further, the cavity positioning groove of the base has a single-sided gap of ≤0.06mm with the gun body. Preferably, when no elbow clamping force is applied, the gap between the cavity fixing plate and the base is 1mm.

[0048] In this embodiment, during the laser welding process, both the welded cavity and the welded cover plate need to be pressed and fixed by a pressure plate, pressure bar, or other mechanism.

[0049] like Figure 2-5 The device includes an elbow clamp and a cover plate fixing plate. The base includes a cover plate fixing plate limiting groove. The cover plate fixing plate is installed on the cavity fixing plate and limited in the cover plate fixing plate limiting groove. It includes a soft pad, which is disposed on the bottom surface of the cover plate fixing plate. A soft material is disposed under the cover plate fixing plate to avoid scratching the cover plate.

[0050] The cover plate fixing pressure plate is configured as a contour structure, contacting the entire cover plate surface of the base; the elbow clamp presses the cover plate fixing pressure plate, and welding is performed by the elbow clamp pressing and fixing fixture; preferably, the portion of the cover plate fixing pressure plate that crosses the weld seam is reduced to increase the weld seam area of ​​the first continuous welding, so that the cover plate is in a pressed and fixed state when welding within the largest possible welding range; the elbow clamp, preferably, or screws and other locking methods, presses the cover plate fixing pressure plate.

[0051] In this embodiment, during laser welding, the cavity to be welded and the cover plate to be welded need to be separated and pressed and fixed by a pressure plate, pressure bar, or other mechanism. Furthermore, the cover plate fixing pressure plate, pressure bar, or other mechanism should conform to the cover plate as much as possible.

[0052] Furthermore, during operation, the cavity is first secured separately by the cavity fixing plate, and then the cover plate fixing plate is pressed down by an elbow clamp, preferably a screw, or other locking method, so that the cover plate remains pressed and fixed during most of the continuous laser welding process. Preferably, the bottom surface of the cover plate fixing plate is lined with a 0.5mm thick soft material. When no elbow clamp force is applied, the gap between the cover plate fixing plate and the cavity fixing plate is 1mm.

[0053] In this embodiment, a base, an elbow clamp, a cavity fixing plate, and a cover plate fixing plate are included. The base has an inner groove-shaped structure, and threaded holes are provided on both sides of the inner groove-shaped structure to connect the elbow clamp. The elbow clamp presses the cavity fixing plate and the cover plate fixing plate to fix the welded cavity. When switching cavities, the elbow clamp releases the cavity fixing plate and the cover plate fixing plate.

[0054] In this embodiment, the device includes an elbow clamp that separately presses the cavity fixing plate, and an elbow clamp that separately presses the cover plate fixing plate. The laser welding fixture uses an elbow clamp to press or fix the pressure plate, or a pressure bar, pressure block, or other mechanism for pressing and fixing.

[0055] Example 2

[0056] like Figure 1-5 As shown, this embodiment provides a method for laser welding fixtures for weak shells, including a base, an elbow clamp, a cavity fixing plate, and a cover plate fixing plate, employing a continuous laser welding method, including the following steps:

[0057] S1: Assemble the base, cavity, cavity fixing plate and cover plate fixing plate to form a welding fixture. Then, use elbow clamps to press the cavity fixing plate and cover plate fixing plate respectively to fix the cavity fixing plate and cover plate fixing plate separately.

[0058] S2: Use the cover plate to fix the pressure plate of the base to fix the cover plate. After fixing, perform the first welding of the weld by continuously laser welding more than 50% of the area.

[0059] S3: Remove the cover plate fixing plate. When only the cavity fixing plate is used to press the cavity, directly use continuous laser welding to weld the remaining area after the first welding to complete the secondary welding of the weld.

[0060] In this embodiment, a cover plate fixing pressure plate is included. The cover plate fixing pressure plate is narrowed in the part that crosses the weld seam. It needs to be as narrow as possible to increase the continuous weld seam area of ​​the first weld. When welding within the increased welding range, the cover plate is in a state of being pressed and fixed.

[0061] In this embodiment, unlike the existing technology of "fixing the cover plate by spot welding and then continuously welding after removing the half-cover fixing plate", the welding process in this embodiment is "continuously welding most of the area with the cover plate fixing plate and then continuously welding the remaining part after removing the cover plate fixing plate". Its feature is that the spot welding process is eliminated, resulting in higher welding efficiency. During operation, the base, cavity, cavity fixing plate and cover plate fixing plate are assembled first. Then, the cavity fixing plate and cover plate fixing plate are pressed together by elbow clamps, preferably screws or other locking methods. When the laser has continuously welded most of the area, the cover plate fixing plate is removed and the remaining area is welded.

[0062] In this embodiment, the continuous welding area is more than 50% of the area.

[0063] In this embodiment, preferably, in steps S2 and S3, when the cover plate is fixed by the cover plate fixing plate, continuous laser welding is directly used to weld the weld seam of 75% of the area; when the cover plate fixing plate is removed and only the cavity fixing plate is used, continuous laser welding is directly used to weld the weld seam of the remaining 25% of the area.

[0064] In this embodiment, the elbow clamp is mounted on the base. When the elbow clamp is working, it can press the pressure plate to fix the cavity. When the elbow clamp is released, the pressure plate can be easily removed without interfering with the laser welding of the weld. During operation, the elbow clamp fixes the cavity to be welded by pressing the pressure plate. When switching cavities, the elbow clamp is released, which can achieve simple and fast operation in scenarios where the pressure plate needs to be frequently raised and lowered to frequently switch cavities.

[0065] Example 3

[0066] like Figure 2-6 As shown, this embodiment provides an inspection method for laser welding fixtures used on weak shells, including a base, a cavity fixing plate, and a cover plate fixing plate. During operation, the cavity, cavity fixing plate, and cover plate fixing plate are installed into the base to complete the assembly, including the following steps:

[0067] S1: Set the calibration ruler to be placed between the cavity and the wall fixing plate, or between the cover plate and the cover plate fixing plate, and press the cavity fixing plate and the cover plate fixing plate respectively with the elbow clamp.

[0068] S2: Pull out the calibration ruler. If the calibration ruler can be pulled out, it means that the clamping force of the welding fixture is insufficient and needs to be adjusted. Use the calibration ruler to check the gap between the cover plate fixing plate and the cover plate, and check the gap between the cavity fixing plate and the cavity.

[0069] In this embodiment, during the inspection process, the clamping force at the four corners and the center of the cavity fixing plate and the cover plate fixing plate is tested by calibrating a ruler.

[0070] In this embodiment, the inspection process uses calibration plates to check the gap between the cover plate fixing plate and the cover plate, and to check the gap between the cavity fixing plate and the cavity, to ensure that the cover plate fixing plate and the wall fixing plate are working properly. For laser welding fixtures, calibration rulers, feeler gauges, or other thin plates are used to check whether the clamping force of the pressure plate, pressure strip, pressure block, or other mechanisms is appropriate.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser welding fixture for weak shells, characterized in that, Includes a base (1), which is a groove-shaped structure, including a cavity positioning groove and a cavity fixing plate (3) limiting groove; a cavity is placed on the base (1), and the cavity is limited within the cavity positioning groove of the base (1); a cavity fixing plate (3) is installed on the base (1) and limited within the cavity fixing plate (3) limiting groove, and the cavity fixing plate (3) is a contoured boss structure, which contacts the cavity part outside the weld seam through the contoured boss structure; Includes elbow clamp (2) and cover plate fixing pressure plate (4). The base (1) includes a cover plate fixing pressure plate (4) limiting groove. The cover plate fixing pressure plate (4) is installed on the cavity fixing pressure plate (3) and limited in the cover plate fixing pressure plate (4) limiting groove. The cover plate fixing pressure plate (4) is set as a contour structure and contacts the entire cover plate surface of the base (1). The cover plate fixing pressure plate (4) is reduced in the part that crosses the weld seam to increase the continuous weld seam area of ​​the first weld and increase the cover plate being pressed and fixed during welding within the welding range. The base (1) has threaded holes on both sides of its inner groove structure for connecting elbow clamps (2). The elbow clamps (2) individually press the cavity fixing plate (3) and the cover plate fixing plate (4) to fix the cavity to be welded. When switching cavities, the elbow clamps (2) release the cavity fixing plate (3) and the cover plate fixing plate (4). During welding, the cavity is first fixed by the cavity fixing plate (3), and then the cover plate fixing plate (4) is pressed down by the elbow clamps (2) so that the cover plate and the cavity remain fixed during the continuous laser welding process. Includes a soft gasket, which is placed on the bottom surface of the cover plate fixing plate (4).

2. The method for laser welding fixtures for weak shells according to claim 1, characterized in that, The components include a base (1), an elbow clamp (2), a cavity fixing plate (3), and a cover plate fixing plate (4), and are welded using a continuous laser welding method, including the following steps: S1: Assemble the base (1), cavity, cavity fixing plate (3) and cover plate fixing plate (4) to form a welding fixture as a whole. Then, use elbow clamp (2) to press the cavity fixing plate (3) and cover plate fixing plate (4) respectively to fix the cavity fixing plate (3) and cover plate fixing plate (4) respectively. S2: Use the cover plate to fix the pressure plate (4) to fix the cover plate of the base (1). After fixing, the weld seam of more than 50% area is welded by continuous laser welding to carry out the first welding of the weld seam. S3: Remove the cover plate fixing plate (4). When using only the cavity fixing plate (3) to press and fix the cavity, directly use continuous laser welding to weld the remaining area after the first welding to complete the secondary welding of the weld.

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