Laser plastic welding apparatus

Abstract

The application discloses laser plastic welding equipment and belongs to the field of laser welding, and comprises a lower cabinet and an upper cabinet fixed on the lower cabinet, a support and a Z-axis platform are fixed on the lower cabinet, a displacement sensor is fixed on the support, a laser generating part is fixed on one side of a moving part of the Z-axis platform, a rotating part is rotatably connected to the lower cabinet, a jacking part is movably connected in the rotating part, and a jacking unit for jacking up the jacking part is fixed in the lower cabinet; a protective film is arranged below the transparent glass, the protective film can form a flexible buffer layer between the workpiece and the transparent glass, the sharp edges or tiny particles on the surface of the workpiece cannot directly contact the glass, and thus the surface of the transparent glass is protected; even if scratches occur, the replaceable protective film can be replaced, and the transparent glass does not need to be repaired, the cost of the protective film is much lower than that of the transparent glass, production cost is reduced, and the maintenance cycle is shortened.

Description

Technical Field

[0001] This invention relates to the field of laser welding, and more specifically, to laser plastic welding equipment. Background Technology

[0002] Laser plastic welding is a welding technique that uses a laser beam as a heat source to join two or more plastic parts together. It is increasingly used in precision manufacturing, medical devices, automobiles, electronics, and other fields.

[0003] When laser welding plastic parts, the collapse value of the workpiece needs to be detected after welding. Currently, laser welding machines on the market typically detect the collapse value by controlling the extension and retraction of a cylinder to lower a transparent pressure plate, which then presses against the workpiece. Sensors on the pressure plate monitor its displacement, and the collapse value is obtained from the displacement. To ensure laser transmittance, the transparent pressure plate is usually made of glass. The glass side needs to frequently contact the workpiece under certain pressure. During the pressing process, minor scratches will appear on the glass. Over time, fine scratches will appear on the side of the pressure plate that contacts the workpiece. These scratches will cause local scattering and diffraction, resulting in uneven laser energy transmission. Regular repair of the scratches on the pressure plate surface or replacement of the pressure plate is required, increasing production costs. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this invention is to provide laser plastic welding equipment.

[0005] To solve the above problems, the present invention adopts the following technical solution.

[0006] A laser plastic welding device includes a lower cabinet and an upper cabinet fixed to the lower cabinet. A support and a Z-axis platform are fixed to the lower cabinet, and a displacement sensor is fixed to the support. A laser generator is fixed to one side of the moving part of the Z-axis platform. A rotating part is rotatably connected to the lower cabinet, and a lifting part is movably connected inside the rotating part. A lifting unit for lifting the lifting part is fixed inside the lower cabinet. The device also includes a pressing part connected inside the support, comprising a cavity inside the support, a frame connected to the inner wall of the cavity, a transparent glass connected below the frame, and a protective film connected below the transparent glass. The laser generator is located above the pressing part, and the pressing part is located above the lifting part.

[0007] Furthermore, the lifting part includes multiple guide shafts movably inserted into the rotating part, an upper top plate fixed to the upper end of the multiple guide shafts, and a lower top plate fixed to the lower end of the multiple guide shafts.

[0008] Furthermore, an encapsulation part is fixedly connected to the lower end of the frame, and both the transparent glass and the protective film are encapsulated in the encapsulation part; the encapsulation part includes an upper frame fixed to the lower end of the encapsulation part, a middle frame fixed to the lower end of the upper frame, and a lower frame fixed to the lower end of the middle frame, the transparent glass is located between the upper frame and the middle frame, and the protective film is located between the transparent glass and the lower frame.

[0009] Furthermore, a sealing gasket is provided on the upper surface of the middle frame, and a clearance groove matching the sealing gasket is provided on the lower surface of the transparent glass, with the sealing gasket embedded in the clearance groove; a sealing gasket is provided on the upper surface of the lower frame, and the upper surface of the sealing gasket is in contact with the lower surface of the protective film.

[0010] Furthermore, a refractive matching layer is provided between the lower surface of the transparent glass and the upper surface of the protective film.

[0011] Furthermore, a cooling blowing unit is fixedly connected to the lower surface of the lower frame, and the cooling blowing unit includes a shell fixedly connected to the lower surface of the lower frame, an opening opened on the lower surface of the shell, a filter screen fixedly connected in the opening, an air duct opened inside the shell, a first cross-flow fan fixedly connected inside the shell with its air outlet inserted into the air duct, and a guide section rotatably connected to the inner wall of the air duct to guide the airflow toward the protective membrane.

[0012] Furthermore, the airflow guiding part includes three air guide plates rotatably connected to the inner wall of the air duct, three sprockets rotatably connected to the inside of the housing and fixed to one end of each of the three air guide plates, two chain belts connecting one of the sprockets to the other two sprockets respectively, and an adjustment part rotatably connected to the outer surface of one side of the housing and fixed to one of the sprockets.

[0013] Furthermore, a negative pressure smoking box is fixedly connected to the upper end of the lower cabinet, and a bracket is fixedly connected to the upper end of the negative pressure smoking box. A second cross-flow fan is also fixedly connected inside the housing, and the air outlet of the second cross-flow fan extends outward through the housing and faces the negative pressure smoking box.

[0014] Furthermore, two sliding grooves are symmetrically formed on the inner wall of the cavity, and two sliders are symmetrically fixed to both sides of the frame. The two sliders are respectively slidably connected in the two sliding grooves. A lead screw is screwed into one of the sliders, and both ends of the lead screw are rotatably connected to the inner wall of the sliding groove. A motor is fixed inside the bracket, and the output shaft of the motor is connected to one end of the lead screw.

[0015] Furthermore, a position sensor is fixedly connected to one side of the bracket, and a grating assembly is fixedly connected to the upper end of the lower cabinet.

[0016] Compared with the prior art, the present invention has the following advantages.

[0017] (1) This solution provides a protective film under the transparent glass. The protective film can form a flexible buffer between the workpiece and the transparent glass, so that the sharp edges or tiny particles on the surface of the workpiece do not directly contact the glass, thus protecting the surface of the transparent glass. Even if scratches occur, only the replaceable protective film needs to be replaced, and there is no need to repair the transparent glass. The cost of the protective film is much lower than the cost of the transparent glass, which reduces production costs and shortens the maintenance cycle.

[0018] (2) This solution provides a refractive matching layer between the transparent glass and the protective film. The refractive matching layer can fill the gap between the protective film and the transparent glass, avoiding light spot interference or local energy loss caused by the air gap; reducing interface reflection and scattering, making the welding laser transmission more uniform; at the same time, the refractive matching layer also helps to make the local high temperature caused by the laser passing through the interface diffuse more uniformly, reducing the thermal stress and local cracking risk of the protective film.

[0019] (3) This solution is equipped with a cold blowing section, which can reduce the surface temperature of the protective film, suppress local overheating, and the hot spots caused by laser irradiation or scattering / absorption can be carried away by the wind, reducing the temperature rise of the protective film and the refractive matching layer, and reducing the risk of bubble precipitation and thermal degradation; at the same time, continuous heat dissipation can slow down the aging, discoloration or microcrack expansion of the refractive matching layer caused by repeated heating; and the cold blowing section can also clean the upper part of the workpiece that is in contact with the protective film, blowing away impurities that may cause scratches on the upper part of the workpiece, reducing the risk of the workpiece damaging the protective film. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the grating component structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the rotating part, the position sensor, the negative pressure smoking box, and the lifting part of the present invention;

[0023] Figure 4 This is a schematic diagram of the cavity and displacement sensor structure of the present invention;

[0024] Figure 5 This is a schematic diagram of the protective membrane structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the slide, lead screw, and motor structure of the present invention;

[0026] Figure 7 This is a schematic diagram of the framework structure of the present invention;

[0027] Figure 8This is a schematic diagram of the slider structure of the present invention;

[0028] Figure 9 This is a cross-sectional view of the packaging portion of the present invention;

[0029] Figure 10 For the present invention Figure 9 Enlarged schematic diagram of the structure at point A in the middle;

[0030] Figure 11 This is a schematic diagram of the packaging portion of the present invention;

[0031] Figure 12 This is a schematic diagram of the adjustment part structure of the present invention;

[0032] Figure 13 This is a cross-sectional view of the cooling blowing section of the present invention;

[0033] Explanation of the labels in the diagram:

[0034] 1. Lower cabinet; 2. Upper cabinet; 3. Grating assembly; 4. Rotating part; 5. Z-axis platform; 6. Laser generator; 7. Bracket; 71. Displacement sensor; 72. Position sensor; 73. Negative pressure smoking box; 8. Top plate; 9. Guide shaft; 10. Lower plate; 11. Pressing part; 111. Cavity; 112. Frame; 113. Transparent glass; 114. Protective film; 12. Slide groove; 13. Lead screw; 1 4. Motor; 15. Slider; 16. Encapsulation unit; 161. Upper frame; 162. Middle frame; 163. Lower frame; 164. Refractive matching layer; 165. Sealing gasket one; 166. Sealing gasket two; 17. Cooling unit; 171. Housing; 172. First cross-flow fan; 173. Second cross-flow fan; 174. Filter screen; 175. Air guide plate; 176. Sprocket; 177. Chain belt; 178. Adjustment unit. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Please see Figures 1 to 13The laser plastic welding equipment includes a lower cabinet 1 and an upper cabinet 2 fixed to the lower cabinet 1. A bracket 7 and a Z-axis platform 5 are fixed to the lower cabinet 1, and a displacement sensor 71 is fixed to the bracket 7. A laser generator 6 is fixed to one side of the moving part of the Z-axis platform 5. A rotating part 4 is also rotatably connected to the lower cabinet 1, and a lifting part is movably connected inside the rotating part 4. A lifting unit for lifting the lifting part is fixed inside the lower cabinet 1. The equipment also includes a pressing part 11 connected inside the bracket 7. The pressing part 11 includes a cavity 111 opened inside the bracket 7, a frame 112 connected to the inner wall of the cavity 111, a transparent glass 113 connected below the frame 112, and a protective film 114 connected below the transparent glass 113. The laser generator 6 is located above the pressing part 11, and the pressing part 11 is located above the lifting part. A position sensor 72 is also fixedly connected to one side of the bracket 7. The position sensor 72 can detect the position of the upper top plate 8 to determine whether the upper top plate 8 has reached the designated position. Only when the upper top plate 8 reaches the designated position will the cylinder inside the lower cabinet 1 perform the extension and retraction movement. A grating assembly 3 is fixedly connected to the upper end of the lower cabinet 1. When manual feeding is performed, the grating assembly 3 can detect the obstruction. At this time, the rotating part 4 cannot rotate, thus achieving safe feeding.

[0037] The lifting section includes multiple guide shafts 9 movably inserted into the rotating section 4, an upper top plate 8 fixed to the upper end of the multiple guide shafts 9, and a lower top plate 10 fixed to the lower end of the multiple guide shafts 9.

[0038] The lower end of the frame 112 is fixedly connected to an encapsulation part 16, and both the transparent glass 113 and the protective film 114 are encapsulated in the encapsulation part 16. The encapsulation part 16 includes an upper frame 161 fixedly connected to the lower end of the encapsulation part 16, a middle frame 162 fixedly connected to the lower end of the upper frame 161, and a lower frame 163 fixedly connected to the lower end of the middle frame 162. The transparent glass 113 is located between the upper frame 161 and the middle frame 162, and the protective film 114 is located between the transparent glass 113 and the lower frame 163.

[0039] By adopting the above technical solution, a fixture is fixed to the upper end of the upper top plate 8, and a workpiece is fixed in the fixture. The rotating part 4 drives the lifting part and the workpiece to rotate, so that the workpiece moves to below the encapsulation part 16. The cylinder inside the lower cabinet 1 lifts the lifting part, so that the upper top plate 8 drives the fixture and the workpiece to move towards the encapsulation part 16, and the upper end of the workpiece contacts the lower surface of the protective film 114. The protective film 114 can form a flexible buffer between the workpiece and the transparent glass 113, so that the sharp edges or small particles on the surface of the workpiece do not directly contact the glass, thereby protecting the surface of the transparent glass 113. Even if scratches occur, only the replaceable protective film 114 needs to be replaced, and there is no need to repair the transparent glass 113. The cost of the protective film 114 is much lower than the cost of the transparent glass 113, reducing production costs and shortening the maintenance cycle. After the workpiece and the protective film 114 are attached, the pressure sensor can detect the pressure value before welding, and at the same time, the displacement sensor 71 can detect the gap value between the upper top plate 8 and the bracket 7. This gap value is the initial gap value; then, a laser is generated by the laser generator 6, which passes through the transparent glass 113 and the protective membrane 114 and welds the workpiece; after welding, the cylinder in the lower cabinet 1 retracts and resets, and the upper top plate 8 and the fixture move downwards under the influence of gravity. After the workpiece cools down, the cylinder extends again and lifts the lower top plate 10, the upper top plate 8 and the fixture, so that the workpiece contacts the lower end of the protective membrane 114 again. At the same time, the pressure sensor detects the pressure applied by the cylinder to ensure that the pressure value after welding is the same as the pressure value before welding. Then, the displacement sensor 71 detects the gap value between the upper top plate 8 and the support 7. This gap value is the welded gap value. Since the pressure sensor can cooperate with the cylinder to adjust the air pressure in real time according to the pressure value to adjust the magnitude of the pressure force, under the condition of ensuring stable pressure (the pressure before welding and the pressure after welding are the same), the initial gap value between the upper top plate 8 and the support 7 before welding is compared with the welded gap value between the upper top plate 8 and the support 7 after welding. The difference between the two is the collapse value caused by welding.

[0040] like Figures 9-11 As shown, a sealing gasket 165 is provided on the upper surface of the middle frame 162, and a clearance groove matching the sealing gasket 165 is provided on the lower surface of the transparent glass 113, with the sealing gasket 165 embedded in the clearance groove; a sealing gasket 166 is provided on the upper surface of the lower frame 163, and the upper surface of the sealing gasket 166 is in contact with the lower surface of the protective film 114.

[0041] A refractive matching layer 164 is also provided between the lower surface of the transparent glass 113 and the upper surface of the protective film 114.

[0042] By adopting the above technical solution, the refractive matching layer 164 can fill the gap between the protective film 114 and the transparent glass 113. The refractive matching layer 164 is a refractive index matching liquid, and different matching liquids can be selected according to the actual situation, such as perfluorinated liquid, optical coupling agent and other matching liquids. The refractive matching layer 164 can avoid the light spot interference or local energy loss caused by the air gap; reduce interface reflection and scattering, and make the welding laser transmission more uniform; at the same time, the refractive matching layer 164 also helps to make the local high temperature caused by the laser passing through the interface more uniformly diffused, reducing the thermal stress and local cracking risk of the protective film 114.

[0043] like Figure 12 and Figure 13 As shown, a cooling air section 17 is also fixedly connected to the lower surface of the lower frame 163, and the cooling air section 17 includes a housing 171 fixedly connected to the lower surface of the lower frame 163, an opening on the lower surface of the housing 171, a filter screen 174 fixedly connected to the opening, an air duct opened inside the housing 171, a first cross-flow fan 172 fixedly connected to the inside of the housing 171 and whose air outlet is inserted into the air duct, and a guide section rotatably connected to the inner wall of the air duct to guide the airflow toward the protective membrane 114.

[0044] The airflow guiding section includes three air guide plates 175 rotatably connected to the inner wall of the air duct, three sprockets 176 rotatably connected to the inside of the housing 171 and fixed to one end of each of the three air guide plates 175, two chain belts 177 connecting one of the sprockets 176 to the other two sprockets 176 respectively, and an adjustment section 178 rotatably connected to the outer surface of one side of the housing 171 and fixed to one of the sprockets 176.

[0045] The upper end of the lower cabinet 1 is also fixedly connected to a negative pressure smoking box 73, and the bracket 7 is fixedly connected to the upper end of the negative pressure smoking box 73. The inside of the housing 171 is also fixedly connected to a second cross-flow fan 173, and the air outlet of the second cross-flow fan 173 extends outward through the housing 171 and faces the negative pressure smoking box 73.

[0046] By adopting the above technical solution, the first cross-flow fan 172 blows air, which is guided by the air guide plate 175 to be blown onto the protective membrane 114. This can reduce the surface temperature of the protective membrane 114, suppress local overheating, and carry away hot spots caused by laser irradiation or scattering / absorption, reducing the temperature rise of the protective membrane 114 and the refractive matching layer 164, and reducing the risk of bubble precipitation and thermal degradation. At the same time, continuous heat dissipation can slow down the aging, discoloration, or microcrack propagation of the refractive matching layer 164 caused by repeated heating. Furthermore, the first cross-flow fan 172 can also... The upper part of the workpiece in contact with the protective membrane 114 is blown away to remove impurities that may cause scratches, reducing the risk of the workpiece damaging the protective membrane 114. By rotating the adjustment unit 178, one of the sprockets 176 can be driven to rotate. The rotating sprocket 176 drives the other two sprockets 176 to rotate through two chain belts 177, thereby realizing the synchronous adjustment of multiple air guide plates 175. The air guide plates 175 can be adjusted according to the area through which the laser passes through the protective membrane 114, so that the blown air can reach the area through which the laser passes.

[0047] like Figures 6-8 As shown, two sliding grooves 12 are symmetrically opened on the inner wall of the cavity 111, and two sliders 15 are symmetrically fixed on both sides of the frame 112. The two sliders 15 are respectively slidably connected in the two sliding grooves 12. A lead screw 13 is screwed into one of the sliders 15, and both ends of the lead screw 13 are rotatably connected to the inner wall of the sliding groove 12. A motor 14 is fixed inside the bracket 7, and the output shaft of the motor 14 is connected to one end of the lead screw 13.

[0048] By adopting the above technical solution, the motor 14 drives the lead screw 13 to rotate, and the rotation of the lead screw 13 drives the slider 15 to move in the slide groove 12. The movement of the slider 15 drives the frame 112, the transparent glass 113, and the protective film 114 to move. When the transparent glass 113 and the protective film 114 move, the position of the lower surface of the protective film 114 in contact with the workpiece changes. By periodically changing the position of the protective film 114, the position of the protective film 114 that was not in contact with the workpiece can be used as a new contact surface to contact the workpiece. This can extend the service life of the protective film 114, reduce the replacement frequency of the protective film 114, save costs, and make full use of the protective film 114. On the other hand, it can avoid the fine scratches on the part of the protective film 114 that has been in contact with the workpiece for a long time, which would affect the laser transmittance.

[0049] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. Laser plastic welding equipment, comprising a lower cabinet (1) and an upper cabinet (2) fixed on the lower cabinet (1), characterized in that: the lower cabinet (1) is fixed with a support (7) and a Z-axis platform (5), and the support (7) is fixed with a displacement sensor (71), one side of the moving part of the Z-axis platform (5) is fixed with a laser generating part (6), the lower cabinet (1) is further rotatably connected with a rotating part (4), and the rotating part (4) is movably connected with a jacking part inside, and the lower cabinet (1) is fixed with a jacking unit for jacking the jacking part; it also includes a pressing part (11) connected inside the support (7), and the pressing part (11) includes a cavity (111) opened in the support (7), a frame (112) connected to the inner wall of the cavity (111), a transparent glass (113) connected below the frame (112), and a protective film body (114) connected below the transparent glass (113); the laser generating part (6) is located above the pressing part (11), and the pressing part (11) is located above the jacking part; the jacking part includes a plurality of guide shafts (9) movably inserted into the rotating part (4), an upper top plate (8) fixed to the upper ends of the guide shafts (9), and a lower top plate (10) fixed to the lower ends of the guide shafts (9); the lower end of the frame (112) is fixed with an encapsulation part (16), and the transparent glass (113) and the protective film body (114) are encapsulated in the encapsulation part (16); the encapsulation part (16) includes an upper frame (161) fixed to the lower end of the encapsulation part (16), a middle frame (162) fixed to the lower end of the upper frame (161), and a lower frame (163) fixed to the lower end of the middle frame (162); the transparent glass (113) is located between the upper frame (161) and the middle frame (162), and the protective film body (114) is located between the transparent glass (113) and the lower frame (163); the upper surface of the middle frame (162) is provided with a sealing gasket (165), and the lower surface of the transparent glass (113) is provided with an avoidance groove matched with the sealing gasket (165), and the sealing gasket (165) is embedded in the avoidance groove; the upper surface of the lower frame (163) is provided with a sealing gasket (166), and the upper surface of the sealing gasket (166) is matched with the lower surface of the protective film body (114); the lower surface of the transparent glass (113) and the upper surface of the protective film body (114) are further provided with a refractive matching layer (164); the lower surface of the lower frame (163) is further fixed with a cold blowing part (17), and the cold blowing part (17) includes a housing (171) fixed to the lower surface of the lower frame (163), an opening formed in the lower surface of the housing (171), a filter screen (174) fixed in the opening, an air duct formed in the housing (171), a first cross-flow fan (172) fixed in the housing (171) and having an air outlet end inserted into the air duct, and a flow guiding part rotatably connected to the inner wall of the air duct to guide the airflow to the protective film body (114). The flow guide part comprises three air deflectors (175) rotatably connected to the inner wall of the air duct, three sprockets (176) rotatably connected to the inside of the shell (171) and fixedly connected to one end of the three air deflectors (175) respectively, two chain belts (177) connecting one of the sprockets (176) with the other two sprockets (176) respectively, and an adjusting part (178) rotatably connected to the outer surface of one side of the shell (171) and fixedly connected to one of the sprockets (176). The upper end of the lower cabinet (1) is also fixedly connected with a negative pressure smoking box (73), and the support (7) is fixedly connected to the upper end of the negative pressure smoking box (73). The inside of the shell (171) is also fixedly connected with a second cross-flow fan (173), and the air outlet end of the second cross-flow fan (173) penetrates through the shell (171) and is exposed outward and faces the negative pressure smoking box (73). The inner wall of the cavity (111) is symmetrically provided with two sliding grooves (12), and the two sides of the frame (112) are symmetrically fixedly connected with two sliding blocks (15). The two sliding blocks (15) are respectively slidably connected in the two sliding grooves (12). One of the sliding blocks (15) is internally screwed with a lead screw (13), and both ends of the lead screw (13) are rotatably connected with the inner wall of the sliding groove (12). The inside of the support (7) is fixedly connected with a motor (14), and the output shaft of the motor (14) is connected with one end of the lead screw (13).

2. The laser plastic welding apparatus of claim 1, wherein: The support (7) is also fixedly connected with a point sensor (72), and the upper end of the lower cabinet (1) is fixedly connected with a grating assembly (3).

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