Film pasting device for battery module

Abstract

The utility model relates to the technical field of batteries, and particularly discloses a film pasting device for a battery module, which comprises a fixing frame, a lower mold adsorption assembly, an upper mold adsorption assembly and a rubber roller assembly. According to the film pasting device for the battery module, a workpiece to be subjected to film pasting can be limited through the first limiting structure, a film material can be limited through the second limiting structure, meanwhile, the workpiece to be subjected to film pasting is adsorbed through the lower die body, and the film material is adsorbed through the upper die body; by means of the arrangement, the workpiece to be subjected to film pasting and the film material can be effectively fixed, accurate positioning of the workpiece to be subjected to film pasting and the film material is achieved, the film material on the upper die body can be tightly attached to the workpiece to be subjected to film pasting through the rubber roller assembly, the film pasting precision is further improved, deviation of the size of the film material is effectively avoided, and the film pasting efficiency is improved. And the residual rate of bubbles on the surface after film pasting is relatively high.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a film-applying device for battery modules. Background Technology

[0002] Currently, battery modules are typically composed of multiple cells connected in series or parallel, requiring the coating of their surfaces with thermally conductive materials to achieve efficient thermal management. With the rapid development of the new energy vehicle industry, higher demands are placed on the production speed of battery modules. Among these demands, the bonding process of thermal management materials to the battery module surface has become a key factor restricting production line efficiency.

[0003] In existing technologies, the bonding process of surface thermal management materials relies on fully automated film-applying equipment. However, in practical applications, insufficient cutting precision of the film material leads to deviations in film size; high bubble residue rate results in high raw material waste; and existing fully automated film-applying equipment suffers from complex structure, long downtime maintenance cycles, and high maintenance costs, directly affecting production efficiency. Utility Model Content

[0004] The purpose of this invention is to provide a film-applying device for battery modules, so as to solve the problems of poor film-applying accuracy and high bubble residue rate in existing film-applying devices.

[0005] This utility model provides a film-applying device for battery modules. The film-applying device for battery modules includes: a fixing frame; a lower mold adsorption assembly, including a lower mold body and a first limiting structure disposed on the lower mold body, the lower mold body being adjustablely disposed on the fixing frame and capable of adsorbing the workpiece to be film-applied, the first limiting structure being used to limit the workpiece to be film-applied; an upper mold adsorption assembly, including an upper mold body and a second limiting structure disposed on the upper mold body, the upper mold body being rotatably disposed on the fixing frame and capable of moving along the length direction of the fixing frame, the upper mold body being used to adsorb film material, the second limiting structure being used to limit the film material; and a rubber roller assembly disposed on the fixing frame and located above the lower mold body, the rubber roller assembly being movable along the length direction of the fixing frame to drive the upper mold body to move, so that the film material on the upper mold body is adhered to the workpiece to be film-applied.

[0006] As an optional technical solution for the film application device for battery modules, the film application device for battery modules further includes a pneumatic adsorption component. The upper mold body has an upper mold suction chamber, and the lower mold body has a lower mold suction chamber. The upper mold suction chamber and the lower mold suction chamber are both in / out of communication with the pneumatic adsorption component, and the pneumatic adsorption component can provide suction to the upper mold suction chamber and the lower mold suction chamber.

[0007] As an optional technical solution for the film-applying device for battery modules, the pneumatic adsorption assembly includes a first pneumatic pipeline. The first pneumatic pipeline includes a first connecting pipe and a first control valve and a first vacuum generator disposed on the first connecting pipe. One end of the first pneumatic pipeline is connected to the upper mold suction chamber, and the other end can be connected to the air supply device. The first vacuum generator can provide suction to the first connecting pipe, and the first control valve can control the opening and closing of the first connecting pipe.

[0008] As an optional technical solution for the film-applying device for battery modules, the pneumatic adsorption assembly includes a second pneumatic pipeline. The second pneumatic pipeline includes a second connecting pipe and a second control valve and a second vacuum generator disposed on the second connecting pipe. One end of the second pneumatic pipeline is connected to the suction chamber of the lower mold, and the other end can be connected to the air supply device. The second vacuum generator can provide suction to the second connecting pipe, and the second control valve can control the on / off state of the second connecting pipe.

[0009] As an optional technical solution for the film application device for battery modules, the film application device for battery modules further includes a folding plate and a sliding structure. The folding plate is connected to the upper mold body and is connected to the fixing frame through the sliding structure, which extends along the length direction of the fixing frame.

[0010] As an optional technical solution for the film application device for battery modules, the sliding structure includes a slider and a slide rail. The slider is connected to the folding plate, the slide rail is disposed on the fixed frame and extends along the length direction of the fixed frame, and the slider is slidably mounted on the slide rail.

[0011] As an optional technical solution for the film application device for battery modules, the film application device for battery modules further includes a plurality of fine-tuning structures disposed on the fixing frame. The plurality of fine-tuning structures are distributed at intervals along the outer periphery of the lower mold body and all abut against the lower mold body to adjust the position of the lower mold body.

[0012] As an optional technical solution for a film application device for battery modules, the rubber roller assembly includes a rubber roller frame, a rubber roller body, and a pressure adjustment structure. The rubber roller frame is disposed on the fixed frame and can move along the length direction of the fixed frame. The rubber roller body is mounted on the rubber roller frame and abuts against the film material. The pressure adjustment structure is mounted on the rubber roller frame and can adjust the pressure between the rubber roller body and the film material.

[0013] As an optional technical solution for a film-applying device for battery modules, the pressure adjustment structure includes an elastic element and an adjusting bolt. The roller frame includes a sliding frame and two connecting frames disposed at both ends of the sliding frame. The two connecting frames are respectively connected to both ends of the roller body. The two ends of the elastic element are respectively connected to the sliding frame and the connecting frames. The adjusting bolt is threadedly connected to the connecting frames. The adjusting bolt can be screwed on to adjust the pressure between the roller body and the film material by changing the elastic force of the elastic element.

[0014] As an optional technical solution for the film application device for battery modules, the first limiting structure includes a first limiting block and a second limiting block. The first limiting block and the second limiting block are respectively disposed at both ends of the lower mold body, and the first limiting block and the second limiting block respectively limit and cooperate with the two opposite sides of the workpiece to be filmed.

[0015] The beneficial effects of this utility model are as follows:

[0016] This invention provides a film-applying device for battery modules. The device includes a fixing frame, a lower mold adsorption assembly, an upper mold adsorption assembly, and a roller assembly. The lower mold adsorption assembly includes a lower mold body and a first limiting structure disposed on the lower mold body; the upper mold adsorption assembly includes an upper mold body and a second limiting structure disposed on the upper mold body. Using this film-applying device, the first limiting structure can limit the workpiece to be film-applied, and the second limiting structure can limit the film material. Simultaneously, the lower mold body adsorbs the workpiece to be film-applied, and the upper mold body adsorbs the film material. This arrangement effectively fixes the workpiece and the film material, achieving precise positioning. The roller assembly ensures that the film material on the upper mold body adheres tightly to the workpiece, further improving the film-applying accuracy and effectively avoiding dimensional deviations in the film material and high surface bubble residue rates after film application. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the film-applying device for a battery module in an embodiment of this utility model;

[0018] Figure 2 This is a schematic diagram of the film-applying device for the battery module in an embodiment of the present invention from another angle;

[0019] Figure 3 This is a schematic diagram of the structure of the film-applying device for the battery module in an embodiment of this utility model.

[0020] In the picture:

[0021] 1. Fixture;

[0022] 2. Lower mold adsorption assembly; 21. Lower mold body; 22. First limiting structure; 221. First limiting block; 222. Second limiting block;

[0023] 3. Upper mold adsorption assembly; 31. Upper mold body; 32. Second limiting structure;

[0024] 4. Rubber roller assembly; 41. Rubber roller frame; 411. Sliding frame; 412. Connecting frame; 413. Guide rod; 42. Rubber roller body; 43. Pressure adjustment structure; 431. Elastic element; 432. Adjusting bolt;

[0025] 5. Pneumatic adsorption assembly; 51. First pneumatic pipeline; 511. First connecting pipe; 512. First control valve; 513. First vacuum generator; 514. First throttle valve; 52. Second pneumatic pipeline; 521. Second connecting pipe; 522. Second control valve; 523. Second vacuum generator; 524. Second throttle valve;

[0026] 6. Folding plate;

[0027] 7. Sliding structure; 71. Slider; 72. Slide rail; 73. Magnetic limiting block;

[0028] 8. Fine-tune the structure;

[0029] 91. Stroller; 92. Flip handle; 93. Roller handle. Detailed Implementation

[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Moreover, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0034] like Figures 1 to 3As shown, this embodiment provides a film-applying device for battery modules. The film-applying device for battery modules includes a fixing frame 1, a lower mold adsorption assembly 2, an upper mold adsorption assembly 3, and a roller assembly 4. The lower mold adsorption assembly 2 includes a lower mold body 21 and a first limiting structure 22 disposed on the lower mold body 21. The lower mold body 21 is adjustablely positioned on the fixing frame 1 and can adsorb the workpiece to be film-applied. The first limiting structure 22 is used to limit the workpiece to be film-applied. The upper mold adsorption assembly 3 includes an upper mold body 31 and a second limiting structure 32 disposed on the upper mold body 31. The upper mold body 31 is rotatably disposed on the fixing frame 1 and can move along the length direction of the fixing frame 1. The upper mold body 31 is used to adsorb the film material, and the second limiting structure 32 is used to limit the film material. The roller assembly 4 is disposed on the fixing frame 1 and located above the lower mold body 21. The roller assembly 4 can move along the length direction of the fixing frame 1 to drive the upper mold body 31 to move, so that the film material on the upper mold body 31 adheres to the workpiece to be film-applied.

[0035] The film-applying device for battery modules of this invention uses a first limiting structure 22 to limit the workpiece to be applied, and a second limiting structure 32 to limit the film material. Simultaneously, the lower mold body 21 adsorbs the workpiece to be applied, and the upper mold body 31 adsorbs the film material. This configuration effectively fixes the workpiece and the film material, achieving precise positioning. The rubber roller assembly 4 ensures that the film material on the upper mold body 31 adheres tightly to the workpiece, further improving the application accuracy and effectively avoiding dimensional deviations in the film material and high surface bubble residue rates after application.

[0036] Specifically, the film-applying device for battery modules also includes a pneumatic adsorption assembly 5. The upper mold body 31 has an upper mold suction chamber, and the lower mold body 21 has a lower mold suction chamber. Both the upper and lower mold suction chambers are in / out of communication with the pneumatic adsorption assembly 5. This allows the pneumatic adsorption assembly 5 to provide suction to the upper and lower mold suction chambers as needed, thereby enabling the film material to be adsorbed through the upper mold suction chamber and the workpiece to be film-applied to the lower mold suction chamber.

[0037] Specifically, such as Figure 1 and Figure 2As shown, the pneumatic adsorption assembly 5 includes a first pneumatic conduit 51, which includes a first connecting pipe 511, a first control valve 512, and a first vacuum generator 513 mounted on the first connecting pipe 511. One end of the first pneumatic conduit 51 is connected to the upper mold suction chamber, and the other end can be connected to an air supply device. The first vacuum generator 513 can continuously provide suction to the first connecting pipe 511, thereby generating a stable suction. Simultaneously, the first control valve 512 controls the on / off state of the first connecting pipe 511. The first control valve 512 is a foot pedal valve for convenient operation by the operator.

[0038] Optionally, the first pneumatic pipeline 51 further includes a first throttle valve 514 disposed on the first connecting pipe 511, which can adjust the suction force of the first connecting pipe 511 to ensure that the membrane material is placed stably.

[0039] Similarly, the pneumatic adsorption assembly 5 includes a second pneumatic conduit 52, which includes a second connecting pipe 521, a second control valve 522, and a second vacuum generator 523 mounted on the second connecting pipe 521. One end of the second pneumatic conduit 52 is connected to the lower mold suction chamber, and the other end can be connected to the air supply equipment. The second vacuum generator 523 can continuously provide suction to the second connecting pipe 521, thereby generating a stable suction. At the same time, the second control valve 522 controls the opening and closing of the second connecting pipe 521. The first control valve 512 is a manual lever valve for easy operation by the operator.

[0040] Optionally, the second pneumatic pipeline 52 also includes a second throttle valve 524 disposed on the second connecting pipe 521. The suction force of the second connecting pipe 521 can be adjusted by the second throttle valve 524 to ensure that the workpiece to be coated is placed stably.

[0041] In some embodiments, the first limiting structure 22 includes a first limiting block 221 and a second limiting block 222. The first limiting block 221 and the second limiting block 222 are respectively disposed at both ends of the lower mold body 21. The first limiting block 221 and the second limiting block 222 respectively limit and cooperate with the two opposite sides of the workpiece to be coated, thereby restricting the position of the workpiece to be coated.

[0042] Optionally, the positions of the first limiting block 221 and the second limiting block 222 on the lower mold body 21 can be adjusted according to the size of the workpiece to be coated, so as to adapt to workpieces of different sizes to be coated, thereby improving the versatility of the coating device for battery modules.

[0043] Among them, the first limiting block 221 and the second limiting block 222 are connected to the lower mold body 21 by bolts after the appropriate positions are selected.

[0044] Similarly, the second limiting structure 32 includes a third limiting block and a fourth limiting block disposed on the upper mold body 31, both of which can limit the film material. The positions of the third and fourth limiting blocks on the upper mold body 31 are adjustable according to the size of the film material to accommodate different sizes. After selecting a suitable position, the third and fourth limiting blocks are connected to the upper mold body 31 by bolts.

[0045] Specifically, the film-applying device for the battery module also includes a folding plate 6 and a sliding structure 7. The folding plate 6 is connected to the upper mold body 31 and to the fixing frame 1 via the sliding structure 7. This allows the upper mold body 31 to be flipped using the folding plate 6. The sliding structure 7 extends along the length of the fixing frame 1, allowing the upper mold body 31 to move along the length of the fixing frame 1.

[0046] In this embodiment, the sliding structure 7 includes a slider 71 and a slide rail 72. The slider 71 is connected to the folding plate 6, and the slide rail 72 is mounted on the fixed frame 1 and extends along the length of the fixed frame 1. The slider 71 is slidably mounted on the slide rail 72. This arrangement allows the upper mold body 31 to move along the length of the fixed frame 1.

[0047] Specifically, in order to adjust the position of the lower mold body 21, the film-applying device for the battery module also includes multiple fine-tuning structures 8 mounted on the fixing frame 1. These multiple fine-tuning structures 8 are spaced apart along the outer periphery of the lower mold body 21 and all abut against it. This allows for adjusting the position of the lower mold body 21 using these multiple fine-tuning structures 8. The fine-tuning structures 8 include, but are not limited to, micrometer knobs. By rotating the micrometer knobs, the relative position of the lower mold body 21 can be finely adjusted within a certain range, thereby adjusting the edge distance of the product film.

[0048] In this embodiment, the rubber roller assembly 4 includes a rubber roller frame 41, a rubber roller body 42, and a pressure adjustment structure 43. The rubber roller frame 41 is mounted on the fixed frame 1 and can move along the length of the fixed frame 1. The rubber roller body 42 is mounted on the rubber roller frame 41 and abuts against the film material. By mounting the pressure adjustment structure 43 on the rubber roller frame 41, the pressure between the rubber roller body 42 and the film material can be adjusted at any time using the pressure adjustment structure 43, thereby ensuring that the film material can be tightly adhered to the workpiece to be coated.

[0049] The pressure regulating structure 43 includes an elastic element 431 and an adjusting bolt 432. The roller frame 41 includes a sliding frame 411 and two connecting frames 412 disposed at both ends of the sliding frame 411. The two connecting frames 412 are respectively connected to both ends of the roller body 42, and both ends of the elastic element 431 are respectively connected to the sliding frame 411 and the connecting frames 412. The adjusting bolt 432 is threadedly connected to the connecting frames 412. By turning the adjusting bolt 432, the elastic force of the elastic element 431 can be changed, thereby achieving the purpose of adjusting the pressure between the roller body 42 and the film material.

[0050] Optionally, the rubber roller assembly 4 also includes a guide rod 413 disposed on the fixed frame 1. The guide rod 413 extends along the length direction of the fixed frame 1, and the sliding frame 411 is sleeved on the guide rod 413 and slides in cooperation with the guide rod 413.

[0051] Optionally, the film application device for the battery module also includes a trolley 91, on which the mounting bracket 1 is mounted.

[0052] Optionally, the film application device for the battery module also includes a flip handle 92, which is disposed on the upper mold body 31 for easy operation by the operator.

[0053] Optionally, the film application device for the battery module also includes a roller handle 93, which is mounted on the sliding frame 411 for easy operation by the operator.

[0054] Optionally, the film application device for the battery module also includes a magnetic limiting block 73, which is fixed to the slide rail 72 by bolts. When the slider 71 moves to the starting position, the magnetic limiting block 73 can hold the slider 71, thereby ensuring that the lower mold adsorption component 2 and the upper mold adsorption component 3 are in a stable position in the initial state.

[0055] The operation process of the film-applying device for battery modules of this utility model is as follows:

[0056] 1. Push the main body of the rubber roller and the upper mold adsorption assembly to the starting position along the length of the fixed frame, so that the slider and the magnetic limiting block are attached and adsorbed;

[0057] 2. Place the film material on the upper mold body and limit it through the second limiting structure. Step on the foot valve and place the workpiece to be filmed on the lower mold body and limit it through the first limiting structure. Open the hand lever valve.

[0058] 3. Peel off the protective film from the adhesive side of the membrane material;

[0059] 4. Hold the flip handle and flip the upper mold body to a horizontal position, above the lower mold body;

[0060] 5. Hold the roller handle and move the main body of the rubber roller together with the main body of the upper mold to adhere the film to the workpiece to be filmed.

[0061] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A film-applying device for battery modules, characterized in that, include: Fixture (1); The lower mold adsorption assembly (2) includes a lower mold body (21) and a first limiting structure (22) disposed on the lower mold body (21). The lower mold body (21) is tunably disposed on the fixing frame (1) and can adsorb the workpiece to be coated. The first limiting structure (22) is used to limit the workpiece to be coated. The upper mold adsorption assembly (3) includes an upper mold body (31) and a second limiting structure (32) disposed on the upper mold body (31). The upper mold body (31) is rotatably disposed on the fixing frame (1) and can move along the length direction of the fixing frame (1). The upper mold body (31) is used to adsorb the membrane material, and the second limiting structure (32) is used to limit the membrane material. A rubber roller assembly (4) is disposed on the fixed frame (1) and located above the lower mold body (21). The rubber roller assembly (4) can move along the length direction of the fixed frame (1) to drive the upper mold body (31) to move, so that the film material on the upper mold body (31) is attached to the workpiece to be filmed.

2. The film-applying device for battery modules according to claim 1, characterized in that, The film-applying device for the battery module further includes a pneumatic adsorption component (5). The upper mold body (31) has an upper mold suction chamber, and the lower mold body (21) has a lower mold suction chamber. The upper mold suction chamber and the lower mold suction chamber are connected to the pneumatic adsorption component (5) in a way that can be switched on and off. The pneumatic adsorption component (5) can provide suction to the upper mold suction chamber and the lower mold suction chamber.

3. The film-applying device for battery modules according to claim 2, characterized in that, The pneumatic adsorption assembly (5) includes a first pneumatic pipeline (51), which includes a first connecting pipe (511), a first control valve (512), and a first vacuum generator (513) disposed on the first connecting pipe (511). One end of the first pneumatic pipeline (51) is connected to the upper mold suction chamber, and the other end is connected to the air supply device. The first vacuum generator (513) can provide suction to the first connecting pipe (511), and the first control valve (512) can control the opening and closing of the first connecting pipe (511).

4. The film-applying device for battery modules according to claim 2, characterized in that, The pneumatic adsorption assembly (5) includes a second pneumatic pipeline (52), which includes a second connecting pipe (521), a second control valve (522) and a second vacuum generator (523) disposed on the second connecting pipe (521). One end of the second pneumatic pipeline (52) is connected to the lower mold suction chamber, and the other end is connected to the air supply device. The second vacuum generator (523) can provide suction to the second connecting pipe (521), and the second control valve (522) can control the opening and closing of the second connecting pipe (521).

5. The film-applying device for a battery module according to claim 1, characterized in that, The film-applying device for the battery module further includes a folding plate (6) and a sliding structure (7). The folding plate (6) is connected to the upper mold body (31) and is connected to the fixing frame (1) through the sliding structure (7). The sliding structure (7) extends along the length direction of the fixing frame (1).

6. The film-applying device for a battery module according to claim 5, characterized in that, The sliding structure (7) includes a slider (71) and a slide rail (72). The slider (71) is connected to the folding plate (6). The slide rail (72) is disposed on the fixed frame (1) and extends along the length direction of the fixed frame (1). The slider (71) is slidably mounted on the slide rail (72).

7. The film-applying device for a battery module according to claim 1, characterized in that, The film-applying device for the battery module also includes a plurality of fine-tuning structures (8) disposed on the fixing frame (1). The plurality of fine-tuning structures (8) are distributed at intervals along the outer periphery of the lower mold body (21) and all abut against the lower mold body (21) to adjust the position of the lower mold body (21).

8. The film-applying device for a battery module according to claim 1, characterized in that, The roller assembly (4) includes a roller frame (41), a roller body (42), and a pressure adjustment structure (43). The roller frame (41) is mounted on the fixed frame (1) and can move along the length of the fixed frame (1). The roller body (42) is mounted on the roller frame (41) and abuts against the film material. The pressure adjustment structure (43) is mounted on the roller frame (41) and can adjust the pressure between the roller body (42) and the film material.

9. The film-applying device for a battery module according to claim 8, characterized in that, The pressure regulating structure (43) includes an elastic element (431) and an adjusting bolt (432). The roller frame (41) includes a sliding frame (411) and two connecting frames (412) disposed at both ends of the sliding frame (411). The two connecting frames (412) are respectively connected to both ends of the roller body (42). The two ends of the elastic element (431) are respectively connected to the sliding frame (411) and the connecting frame (412). The adjusting bolt (432) is threadedly connected to the connecting frame (412). The adjusting bolt (432) can be screwed on to adjust the pressure between the roller body (42) and the film material by changing the elastic force of the elastic element (431).

10. The film-applying device for a battery module according to any one of claims 1-9, characterized in that, The first limiting structure (22) includes a first limiting block (221) and a second limiting block (222). The first limiting block (221) and the second limiting block (222) are respectively disposed at both ends of the lower mold body (21). The first limiting block (221) and the second limiting block (222) respectively limit and cooperate with the two sides of the workpiece to be coated.

Images