A compact spray device compatible with both small and large workpieces

Abstract

A small and large workpiece compatible spraying device, comprising a product conveying mechanism, a spraying mechanism; the spraying mechanism comprises a first and a second spraying mechanism; the first spraying mechanism comprises a stand, a crossbeam and a plurality of first spraying assemblies, the crossbeam is horizontally arranged along the product conveying direction, the crossbeam is slidably connected to the stand, and the plurality of first spraying assemblies are installed on the crossbeam at intervals; the second spraying mechanism comprises a moving track, a mechanical arm and a second spraying assembly, the moving track is arranged on the side of the first spraying mechanism away from the product conveying mechanism, the moving track is arranged along the product conveying direction, the mechanical arm is slidably connected to the moving track, the mechanical arm can move to a avoiding position and a processing position along the moving track, in the avoiding position, the mechanical arm is located on the side of the first spraying mechanism, and the second spraying assembly is installed on the mechanical arm and sprays paint in the processing position. Compared with the prior art, the device can consider the spraying scheme of the fixed type and the mechanical hand, and realize flexible production of large and small products.

Description

Technical Field

[0001] This utility model belongs to the technical field of spraying equipment, specifically relating to a spraying device compatible with both small and large workpieces. Background Technology

[0002] Currently, there are two technical approaches in the industrial spraying field: For small, regular products (such as cosmetic bottles, medicine bottles, and other rotationally symmetrical objects), a fixed spray gun combined with workpiece rotation is commonly used. For example, in patent announcement number CN213194239U, a conveyor belt drives a rotary table to rotate the bottle, and a fixed spray gun sprays the rotating workpiece. This approach ensures that the spray gun maintains a constant distance from the regular curved surface, guaranteeing a high coating yield. For small, irregularly shaped products (such as those with sharp edges or recessed structures), and for large, irregularly shaped products (such as automotive parts), the industry typically uses a robotic arm tracking spraying solution. As shown in publication number CN106423664A, a robotic arm adjusts the spray gun's posture with multiple degrees of freedom and works in conjunction with the workpiece rotation mechanism to achieve surface coverage.

[0003] To process these two types of products, factories typically set up two production lines. One line uses fixed spray guns to coat small, regular-shaped products, while the other uses robotic arms to coat irregularly shaped products. In actual production, the demand for small, regular-shaped products is high, allowing for continuous production, while the demand for irregularly shaped products is low. Setting up a separate production line for coating irregularly shaped products results in high equipment investment costs, low line utilization, poor line competitiveness, and increased space requirements. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a spraying device that is compatible with both small and large workpieces.

[0005] To achieve the above objectives, this utility model discloses a spraying device compatible with both small and large workpieces, including a product conveying mechanism for conveying products and a spraying mechanism for spraying products, wherein the conveying direction of the product conveying mechanism is a first direction. The spraying mechanism includes a first spraying mechanism and a second spraying mechanism; The first spraying mechanism includes a column, a crossbeam, and multiple sets of first spraying components. The crossbeam is horizontally arranged along the first direction and is slidably connected to the column. Multiple sets of first spraying components are installed at intervals on the crossbeam along the first direction. The second spraying mechanism includes a moving track, a robotic arm, and a second spraying assembly. The moving track is located on the side of the first spraying mechanism away from the product conveying mechanism and is arranged along the first direction. The robotic arm is slidably connected to the moving track and can move along the moving track to an avoidance position and a processing position. In the avoidance position, the robotic arm is located beside the first spraying mechanism. The second spraying assembly is mounted on the robotic arm and sprays paint on the product to be processed in the processing position.

[0006] Preferably, when the robotic arm is processing at the processing position, the product conveying mechanism pauses the conveying of the product to be processed.

[0007] Preferably, at least one end of the moving track extends outside the column.

[0008] Preferably, there are two columns, and the two ends of the crossbeam are slidably connected to the two columns, and each column is provided with a vertically arranged first rack; The crossbeam is equipped with a first driving device, which includes a first motor, a first reducer, two couplings, and two transmission shafts. The first motor is fixedly connected to the crossbeam, and the output end of the first motor is connected to the input end of the first reducer. The first reducer has two output shafts, each of which is connected to one end of a transmission shaft through one of the couplings. The other ends of the two transmission shafts extend along the first direction toward both ends of the crossbeam, and each of the two transmission shafts is provided with a first gear at the end away from the coupling. The first gear engages with a corresponding first rack.

[0009] Preferably, the first motor is located at the top center of the crossbeam.

[0010] Preferably, the moving track is provided with a second rack arranged along the first direction; The second spraying mechanism also includes a base and a second drive device. The bottom of the base is slidably connected to the moving track. The robotic arm is mounted on the base. The second drive device includes a second motor, a second reducer, and a second gear. The second motor is mounted on the base. The output end of the second motor is connected to the input end of the second reducer. The second gear is mounted on the output end of the second reducer and engages with the second rack.

[0011] Preferably, the product conveying mechanism includes a base frame and a chain, a corner sprocket, a positioning component, an input chain adjustment component, and an output chain adjustment component disposed on the base frame; There are multiple corner sprockets, and the multiple corner sprockets are rotatably connected to the base frame; the chain includes a U-shaped input section, a linear processing section, and a U-shaped output section, and a corner sprocket is provided between the input section and the processing section, and between the processing section and the output section; The positioning components are in multiple sets, and the multiple sets of positioning components are rotatably connected to the chain; The input chain adjustment assembly includes a first connecting seat, a first sprocket, and a third drive device. The first connecting seat is slidably connected to the base frame at a position located within the input segment, and the first sprocket is rotatably connected to the first connecting seat and cooperates with the input segment. The output chain adjustment assembly includes a second connecting seat, a second sprocket, and a fourth drive device. The second connecting seat is slidably connected to the base frame at a position located within the output section, and the second sprocket is rotatably connected to the second connecting seat and cooperates with the output section. The third and fourth driving devices are used to drive the corresponding connecting seats to move synchronously along the line connecting the bottom and opening of the corresponding U-shape, and the directions of movement are opposite.

[0012] Preferably, the third drive device and / or the fourth drive device includes a third motor, a third reducer and a third gear connected in sequence, and the base frame is provided with a third rack that cooperates with the third gear.

[0013] Preferably, the product conveying mechanism further includes a start-stop device, which is connected to the corner sprocket and is used to control the corner sprocket to be in a non-rotatable locked state and a rotatable active state.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: The first spraying mechanism has multiple spraying components fixed on the crossbeam to form a fixed spraying mechanism. The second spraying mechanism uses a robotic arm to install the second spraying components. Small, regular products are sprayed through the first spraying mechanism, while irregular, large products are sprayed through the second spraying mechanism. In this way, flexible production of spraying processing for two types of products can be achieved through one production line, without the need to set up two separate production lines, which reduces equipment investment costs and floor space.

[0015] The crossbeam of the first spraying mechanism can move up and down. On the one hand, it can avoid the robotic arm when spraying irregular or large products, thus avoiding interference with the robotic arm. On the other hand, since the product height may be different when processing different products and using different fixtures, the crossbeam is configured to move up and down to adjust the height of the first spraying component to match the product height and improve applicability.

[0016] When one of the spraying units is under maintenance, the other spraying unit can still continue processing without shutting down the entire production line, thus improving production efficiency. Attached Figure Description

[0017] Figure 1 This is a top view of a spraying apparatus compatible with both small and large workpieces, as described in an embodiment. Figure 2 for Figure 1 A three-dimensional view of the spraying device in the state of spraying small parts; Figure 3 for Figure 2 Front view of the spraying device; Figure 4 for Figure 2 Side view of the spraying device; Figure 5 for Figure 1 A three-dimensional exploded view of the first spraying mechanism; Figure 6 for Figure 2 A magnified view of a portion of point A; Figure 7 for Figure 1 A 3D view of the spraying equipment in the process of spraying large products; Figure 8 for Figure 7 Side view of the spraying device; Figure 9 for Figure 1 A 3D view of the input (output) chain adjustment component; Figure 10 for Figure 9 Top view and AA section view of the chain adjustment assembly; Product conveying mechanism 100; base frame 110; third rack 111; chain 120; input section 121; processing section 122; output section 123; positioning assembly 130; corner sprocket 140; input chain adjusting assembly 150; first connecting seat 151; first sprocket 152; third drive device 153; third motor 1531; third reducer 1532; third gear 1533; output chain adjusting assembly 160; second connecting seat 161; second sprocket 162; fourth drive device 163; start / stop device 170; First spraying mechanism 200; column 210; first rack 211; crossbeam 220; first spraying assembly 230; first drive device 240; first motor 241; first reducer 242; coupling 243; transmission shaft 244; first gear 245; Second spraying mechanism 300; moving track 310; second rack 311; robotic arm 320; second spraying assembly 330; base 340; second drive device 350; second motor 351; second reducer 352; second gear 353. Detailed Implementation

[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] A spraying device compatible with both small and large workpieces, wherein the small workpieces specifically refer to small, regular products, and the large products specifically refer to large, irregular products. See also... Figures 1-10 It includes a product conveying mechanism 100 for conveying products and a spraying mechanism for spraying products, wherein the conveying direction of the product conveying mechanism 100 is a first direction.

[0020] The product conveying mechanism 100 includes a base frame 110 and a chain 120 and a positioning component 130 mounted on the base frame 110. During the entire spraying process, the product needs to undergo feeding, painting, drying, and unloading. The chains 120 corresponding to each step are connected sequentially to form a closed, complete chain 120, which can rotate cyclically when driven. The positioning component 130 is installed on the entire complete chain 120 to position and fix the product. Specifically, the positioning component 130 has a rotation function, enabling the product to rotate during the painting step. The positioning component 130 and the structure that allows it to rotate during the painting step can adopt existing structures, such as the self-rotating bottle spraying device disclosed in authorization announcement number CN102698910B, which achieves its rotation function by rotating a vertical shaft mounted on the chain 120, and can rotate during the painting step under the action of a friction drive belt, ultimately achieving self-rotating painting. The above product conveying mechanism 100 is a common existing structure and will not be described in detail here.

[0021] The spraying mechanism includes a first spraying mechanism 200 and a second spraying mechanism 300. The first spraying mechanism 200 includes a column 210, a crossbeam 220, and multiple sets of first spraying components 230. The crossbeam 220 is horizontally arranged along a first direction and is slidably connected to the column 210. The multiple sets of first spraying components 230 are spaced apart on the crossbeam 220 along the first direction. The second spraying mechanism 300 includes a moving track 310, a robotic arm 320, and second spraying components 330. The moving track 310 is the existing ground track of the robotic arm 320. It is located on the side of the first painting mechanism 200 away from the product conveying mechanism 100. The moving track 310 is arranged along the first direction. The robotic arm 320 adopts the existing conventional robotic arm 320, such as a six-axis robotic arm 320, etc. It is slidably connected to the moving track 310. The robotic arm 320 can move along the moving track 310 to the avoidance position and the processing position. In the avoidance position, the robotic arm 320 is located beside the first painting mechanism 200. The second painting component 330 is installed on the robotic arm 320 and sprays paint at the processing position.

[0022] The first spraying assembly 230, fixed to the crossbeam 220, forms a fixed spray gun. Its rotation, combined with the workpiece's rotation, ensures a constant distance between the spray gun and the rotationally symmetric curved surface, guaranteeing uniform spraying. This is suitable for spraying small, regular products. The second spraying assembly 330 has fewer spray guns; for example, in this embodiment, there is only one, reducing the load on the robotic arm. Utilizing the multiple degrees of freedom of the robotic arm 320, and in conjunction with the workpiece's rotation, the second spraying assembly 330 can spray irregular surfaces of irregular and large products. Thus, flexible production of two types of products can be achieved through a single production line, eliminating the need for separate production lines, reducing equipment investment costs and floor space requirements. The crossbeam 220 of the first spraying mechanism 200 can move up and down. On the one hand, it can avoid interference with the robotic arm 320 when spraying irregular or large products. On the other hand, since the height of products may vary when processing different small products or using different fixtures, the crossbeam 220 is configured to move up and down to adjust the height of the first spraying assembly 230 to match the product height, thus improving applicability. When one spraying mechanism is under maintenance, the other spraying mechanism can still operate without shutting down the entire production line, thereby improving production efficiency.

[0023] The first spraying assembly 230 includes multiple mounting brackets and a nozzle mounted on each bracket. The nozzle, after being mounted on its corresponding bracket, faces the area of ​​the product to be painted. By spraying with multiple sets of the first spraying assemblies 230, the painting of small, regular products can be completed. Specifically, this embodiment has 10 sets of first spraying assemblies 230. In practice, not all 10 sets of nozzles need to be activated; for example, sometimes 8 sets are sufficient depending on the product's process requirements. The spraying method of the 10 sets of nozzles 230 can be continuous spraying, or spot spraying (activating the nozzle when a product is detected) can be used when the gap between products is too large. The second spraying assembly 330 is a nozzle directly mounted on the robotic arm 320, which performs the spraying process under the actuation of the robotic arm 320. These two spraying assemblies represent conventional structures of existing fixed spraying devices and robotic arm spraying devices, respectively.

[0024] One end of the moving track 310 extends outside the column 210, allowing the robotic arm 320 to move to the side of the first spraying mechanism 200, thus avoiding interference.

[0025] In traditional robotic arm 320 painting solutions, to achieve curved surface coverage of large products, the robotic arm 320 needs to be equipped with a long reach or a long-stroke track. However, a long reach increases the cost of the robotic arm 320, and a long-stroke track increases the production line length and floor space. In this embodiment, when the robotic arm 320 is painting a large product at the processing position, the product conveying mechanism 100 pauses the conveying of the large product to be processed, and the large product rotates on its own to allow the robotic arm 320 to be painted. This vertex painting method combined with workpiece rotation avoids the time wasted by the robotic arm 320 needing to move back and forth, improves production efficiency, reduces the length of the painting mechanism, and lowers the floor space. In addition, it also eliminates the need for a large reach for the robotic arm 320, reducing its cost.

[0026] In this embodiment, there are two columns 210. Both ends of the crossbeam 220 are slidably connected to the two columns 210 via a guide rail slider structure. Each column 210 is provided with a vertically arranged first rack 211. The crossbeam 220 is provided with a first driving device 240, which includes a first motor 241, a first reducer 242, two couplings 243, and two drive shafts 244. The first motor 241 is fixedly connected to the top middle position of the crossbeam 220. The output end of the first motor 241 is connected to the input end of the first reducer 242. The first reducer has two output shafts, each of which is connected to one end of a drive shaft 244 via a coupling 243. The other ends of the two drive shafts 244 extend towards both ends of the crossbeam 220 along a first direction. The ends of the two drive shafts 244 away from the couplings 243 are provided with first gears 245, which engage with the corresponding first racks 211. When the crossbeam 220 moves up and down, the first motor 241 rotates, driving the two transmission shafts 244 to rotate synchronously through the first reducer 242. This causes the two first gears 245 to move up and down along the first rack 211. The first motor 241 is installed at the top center of the crossbeam 220. In addition to ensuring that the crossbeam 220 has the lowest possible position to fully avoid the robot arm, it can also synchronously drive the two transmission shafts 244 to rotate, causing the two first gears 245 to rotate synchronously. This allows the two ends of the crossbeam 220 to move up and down synchronously, thus ensuring the horizontality of the crossbeam 220. This, in turn, ensures the positional accuracy and spray angle accuracy of the nozzles on the crossbeam 220, improving the uniformity and quality of the coating.

[0027] In this embodiment, a second rack 311 arranged along a first direction is provided on the moving track 310; the second spraying mechanism 300 also includes a base 340 and a second driving device 350. The bottom of the base 340 is slidably connected to the moving track 310, and the robotic arm 320 is mounted on the base 340. The second driving device 350 includes a second motor 351, a second reducer 352, and a second gear 353. The second motor 351 is mounted on the base 340, and its output end is connected to the input end of the second reducer 352. The second gear 353 is mounted on the output end of the second reducer 352 and engages with the second rack 311. When the robotic arm 320 moves, the second motor 351 rotates, driving the second gear 353 to move along the second rack 311 through the second reducer 352. Using a rack and pinion structure to drive the robotic arm 320 improves the moving accuracy and stability of the robotic arm 320.

[0028] In this embodiment, the product conveying mechanism 100 further includes an angle sprocket 140, an input chain adjustment assembly 150, and an output chain adjustment assembly 160 mounted on the base frame 110. Multiple angle sprockets 140 are rotatably connected to the base frame 110. In this embodiment, the teeth on the circumference of all sprockets are not shown. The chain 120 corresponding to the spraying mechanism includes a U-shaped input section 121, a linear processing section 122, and a U-shaped output section 123. An angle sprocket 140 is provided between the input section 121 and the processing section 122, and between the processing section 122 and the output section 123. The angle sprocket 140 rotates under the action of the chain 120. The input chain adjustment assembly 150 includes a first connecting seat 151, a first sprocket 152, and a third drive device 153. The first connecting seat 151 is slidably connected to the base frame within the input section 121 via a guide rail slider structure. The first sprocket 152 is rotatably connected to the first connecting seat 151 and engages with the turning position of the input section 121. The output chain adjustment assembly 160 includes a second connecting seat 161, a second sprocket 162, and a fourth drive device 163. The second connecting seat 161 is also slidably connected to the base frame within the output section 123 via a guide rail slider structure. The second sprocket 162 is rotatably connected to the second connecting seat 161 and engages with the turning position of the output section 123. The third driving device 153 is used to drive the first connecting seat 151 to move along the line connecting the bottom and the opening of the U-shaped input section 121, and the fourth driving device 163 is used to drive the second connecting seat 161 to move along the line connecting the bottom and the opening of the U-shaped output section 123. The first connecting seat 151 and the second connecting seat 161 move synchronously and in opposite directions.

[0029] When painting large products, the robotic arm 320 performs the painting at the processing position. In practice, the chain 120 still needs to remain running during the drying step. For example, when spraying UV paint onto a large product, the spraying time is 1 minute. During the UV paint drying process, ultraviolet light is emitted by UV lamps for 3-5 seconds. If the entire chain 120 stops during this process, the product cannot be transported out of the drying space in time, and it is easily deformed by the heat, resulting in damage. If the UV lamps are turned off directly after drying, the fastest restart time for the existing UV lamps is 3 minutes, which is longer than the painting time, thus affecting the product painting efficiency. Therefore, in this embodiment, the chain 120 is divided into an input section 121, a processing section 122, and an output section 123. When processing large products, under the action of the fourth drive device 163, the second sprocket 162 moves towards the U-shaped opening side of the output section 123 of the chain 120, and the output section 123 replenishes the chain 120 outward. At the same time, under the action of the third drive device 153, the first sprocket 152 moves towards the bottom side of the U-shape of the input section 121 of the chain 120, and the input section 121 retracts the chain 120. The output section 123 and the input section 121 of the chain 120 output one section of the chain 120 and retract the other section of the chain 120. In this way, the processing section 122 of the chain 120 can not operate, ensuring the processing of large products. Moreover, the entire chain 120 can still operate on the turntable while processing the processing section 122. In this way, products located in the drying space can be output, avoiding damage due to excessive drying time, or excessive time to restart the drying lamp after turning it off, which reduces processing efficiency. After the product is painted, the first sprocket 152 and the second sprocket 162 move synchronously to their initial positions under the action of the corresponding drive device. The rotatable state of the first sprocket 152 and the second sprocket 162 allows them to rotate adaptively under the action of the chain 120 during movement, avoiding jamming.

[0030] Since the input chain adjustment assembly 150 and the output chain adjustment assembly 160 have the same structure, only one of the components is shown in the accompanying drawings for illustration.

[0031] The third drive device 153 and the fourth drive device 163 have the same structure. The third drive device 153 is described below: The third drive device 153 includes a third motor 1531, a third reducer 1532, and a third gear 1533 connected in sequence. This structure is fixedly connected to the bottom of the first connecting seat 151. A third rack 111, which meshes with the third gear 1533, is provided on the base frame 110. The third rack 111 is arranged along the line connecting the bottom and opening of the U-shaped input section 121. When the third motor 1531 rotates, it drives the third gear 1533 to rotate via the third reducer 1532. The third gear 1533 and the first connecting seat 151 move along the third rack 111.

[0032] Furthermore, the product conveying mechanism 100 also includes a start-stop device 170, which is fixedly connected to the base frame 110. An angle sprocket 140 is fixedly connected to the start-stop device 170 and is used to control the angle sprocket 140 to be in a non-rotatable locked state and a rotatable movable state. When processing large products, the start-stop device 170 controls the angle sprocket 140 to be in a locked state. This ensures that when the output section 123 replenishes the chain 120 and the input section 121 retracts the chain 120, the chain 120 processing section 122 is locked, preventing the processing section 122 and the product to be processed on the processing section 122 from shifting positions, which could lead to inaccurate painting and reduced painting quality.

[0033] Specifically, the start / stop device 170 can be an existing electromagnetic brake, with the angle sprocket 140 mounted on the brake disc of the electromagnetic brake. When the brake disc is in a braking state, the angle sprocket 140 cannot rotate, thereby clamping the processing section 122 of the chain 120 to prevent deviation and ensure processing quality. When the brake disc is released from braking, the processing section 122 of the chain 120 can rotate with the entire chain 120.

[0034] The above description is only a preferred embodiment of the present utility model, and its structure is not limited to the shapes listed above. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A spraying device compatible with both small and large workpieces, comprising a product conveying mechanism for conveying products and a spraying mechanism for spraying products, wherein the conveying direction of the product conveying mechanism is a first direction, characterized in that: The spraying mechanism includes a first spraying mechanism and a second spraying mechanism; The first spraying mechanism includes a column, a crossbeam, and multiple sets of first spraying components. The crossbeam is horizontally arranged along the first direction and is slidably connected to the column. Multiple sets of first spraying components are installed at intervals on the crossbeam along the first direction. The second spraying mechanism includes a moving track, a robotic arm, and a second spraying assembly. The moving track is located on the side of the first spraying mechanism away from the product conveying mechanism and is arranged along the first direction. The robotic arm is slidably connected to the moving track and can move along the moving track to an avoidance position and a processing position. In the avoidance position, the robotic arm is located beside the first spraying mechanism. The second spraying assembly is mounted on the robotic arm and sprays paint on the product to be processed in the processing position.

2. The spraying device compatible with both small and large workpieces according to claim 1, characterized in that: When the robotic arm is processing at the processing position, the product conveying mechanism pauses the conveying of the product to be processed.

3. The spraying device compatible with both small and large workpieces according to claim 1, characterized in that: At least one end of the moving track extends outside the column.

4. The small- and large-workpiece compatible spraying device according to claim 1, characterized in that: There are two columns, and the two ends of the crossbeam are slidably connected to the two columns respectively. Each column is provided with a vertically arranged first rack. The crossbeam is equipped with a first driving device, which includes a first motor, a first reducer, two couplings, and two transmission shafts. The first motor is fixedly connected to the crossbeam, and the output end of the first motor is connected to the input end of the first reducer. The first reducer has two output shafts, each of which is connected to one end of a transmission shaft through one of the couplings. The other ends of the two transmission shafts extend along the first direction toward both ends of the crossbeam, and each of the two transmission shafts is provided with a first gear at the end away from the coupling. The first gear engages with a corresponding first rack.

5. The small- and large-workpiece compatible spraying device according to claim 4, characterized in that: The first motor is located at the top center of the crossbeam.

6. The small- and large-workpiece compatible spraying device according to claim 1, characterized in that: The moving track is provided with a second rack arranged along the first direction; The second spraying mechanism also includes a base and a second drive device. The bottom of the base is slidably connected to the moving track. The robotic arm is mounted on the base. The second drive device includes a second motor, a second reducer, and a second gear. The second motor is mounted on the base. The output end of the second motor is connected to the input end of the second reducer. The second gear is mounted on the output end of the second reducer and engages with the second rack.

7. The spraying device compatible with small and large workpieces according to claim 1, characterized in that: The product conveying mechanism includes a base frame and a chain, a corner sprocket, a positioning component, an input chain adjustment component, and an output chain adjustment component mounted on the base frame; There are multiple corner sprockets, and the multiple corner sprockets are rotatably connected to the base frame; the chain includes a U-shaped input section, a linear processing section, and a U-shaped output section, and a corner sprocket is provided between the input section and the processing section, and between the processing section and the output section; The positioning components are in multiple sets, and the multiple sets of positioning components are rotatably connected to the chain; The input chain adjustment assembly includes a first connecting seat, a first sprocket, and a third drive device. The first connecting seat is slidably connected to the base frame at a position located within the input segment, and the first sprocket is rotatably connected to the first connecting seat and cooperates with the input segment. The output chain adjustment assembly includes a second connecting seat, a second sprocket, and a fourth drive device. The second connecting seat is slidably connected to the base frame at a position located within the output section, and the second sprocket is rotatably connected to the second connecting seat and cooperates with the output section. The third and fourth driving devices are used to drive the corresponding connecting seats to move synchronously along the line connecting the bottom and opening of the corresponding U-shape, and the directions of movement are opposite.

8. The spraying device compatible with small and large workpieces according to claim 7, characterized in that: The third drive device and / or the fourth drive device include a third motor, a third reducer and a third gear connected in sequence, and the base frame is provided with a third rack that cooperates with the third gear.

9. The spraying device compatible with small and large workpieces according to claim 7, characterized in that: The product conveying mechanism also includes a start-stop device, which is connected to the corner sprocket and is used to control the corner sprocket to be in a non-rotatable locked state and a rotatable movable state.

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