A drying device for surface treatment of metal products
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIEYANG RUNFENGDA METAL SURFACE TREATMENT CO LTD
- Filing Date
- 2025-07-31
- Publication Date
- 2026-06-19
Smart Images
Figure CN224382027U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of metal product surface treatment technology, and specifically to a drying device for metal product surface treatment. Background Technology
[0002] Electrophoretic coating, as an important metal surface anti-corrosion and decorative treatment process, is widely used in the metal products industry due to its advantages such as uniform coating, strong adhesion, good corrosion resistance, and high degree of automation. Applications include automotive parts, drawer slides, and metal structural components. After electrophoretic coating, the wet coating film on the workpiece surface must undergo a crucial drying process. This process uses heating to evaporate the moisture and solvent in the coating film, while simultaneously promoting a cross-linking reaction, ultimately forming a dense, hard coating with excellent protective and decorative properties. Currently, drying of metal products after electrophoresis mainly employs hot air circulating ovens or tunnel drying tunnels. The basic principle is to place the workpiece in a closed or semi-closed heating chamber, using electric heating tubes, gas heaters, or steam heat exchangers to generate hot air. Forced circulation by a fan allows the hot air to flow within the chamber and contact the workpiece surface, thereby transferring heat and achieving coating drying and curing. The existing technology has the following problems:
[0003] Because drawer slide parts typically have slender guide rail bodies, complex bending structures, and grooves and holes for ball bearings or installation, in traditional hot air circulating drying devices, the flow of hot air is often difficult to accurately and evenly cover every corner of these complex structures, especially deep grooves, inner corners, or areas with dense holes. As a result, the temperature in these dead corner areas may be lower than the set process temperature due to the inability of hot air to reach them effectively or the air velocity being too low, leading to incomplete cross-linking and curing of the coating in these areas.
[0004] Meanwhile, existing drying equipment often needs to maintain a large hot air circulation volume and a high overall chamber temperature to ensure temperature uniformity within the chamber. However, for batch processing of drawer slide parts, there is a large amount of space within the chamber that is not occupied by the workpieces, such as the gaps between workpieces, the space occupied by the hangers, and the chamber area far from the workpieces. Continuously heating and maintaining the high temperature in these spaces requires a lot of energy. Some hot air may not fully contact the workpiece surface for effective heat exchange and will directly return to the heating system through the return air vent, resulting in a waste of heat energy. Utility Model Content
[0005] This invention provides a drying device for surface treatment of metal products to solve the problems mentioned in the background art.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0007] A drying device for surface treatment of metal products includes a drying chamber. A conveying mechanism is arranged through the inner cavity of the drying chamber. A preheating box is arranged on the top front side of the conveying mechanism, extending into the inner cavity of the drying chamber. The conveying mechanism includes a conveyor belt that extends through the inner cavity of the drying chamber. A plurality of positioning plates are uniformly fixedly installed on the outer wall of the conveyor belt. Each of the positioning plates has a positioning hole that extends through the front and back. A slide rail component positioning mechanism is arranged on the top of each of the positioning plates. The slide rail component positioning mechanism includes a positioning upright plate. A plurality of positioning placement slots that extend through the front and back are opened on the top of the positioning upright plate. A slide rail component body is arranged in the inner cavity of each of the positioning placement slots. A plurality of guide funnel frames that communicate with the positioning placement slots are fixedly installed on the front side of the positioning upright plate.
[0008] A further improvement of the present invention is that: a hot air heater is fixedly installed on the top of the drying box, and air supply pipes are fixedly connected to both air outlets of the hot air heater; air inlet pipes penetrating the inner cavity are fixedly installed on the front sides of both the left and right ends of the drying box; and the other ends of the two air supply pipes are fixedly connected to the air inlet pipes and penetrate the inner cavity.
[0009] A further improvement of this utility model is that: a horizontal support is provided at the top of several positioning slots, the horizontal support is fixedly installed on the top of the positioning plate, a turntable is rotatably connected to the bottom of the horizontal support, a fixed hanging plate is fixedly installed on the bottom right side of the turntable, a fixed sliding rod is fixedly installed on the left side of the fixed hanging plate, a limiting plate is fixedly installed at the left end of the fixed sliding rod, a spring is fixedly installed at the eccentric right side of the limiting plate, a sliding clamp is slidably installed on the outer wall of the fixed sliding rod, the left side of the sliding clamp is fixedly connected to the right end of the spring, and the slide rail component body is clamped between the opposing surfaces of the fixed hanging plate and the sliding clamp.
[0010] A further improvement of this utility model is that: a slot is provided at the bottom of the positioning plate, the slot engages with the positioning plate, the positioning plate has a positioning control compartment located behind the slot, a sliding plate is slidably installed in the inner cavity of the positioning control compartment, a rod is fixedly installed at the front end of the sliding plate, the front end of the rod penetrates into the inner cavity of the slot and engages with the positioning hole, a pull rod and a second spring are fixedly installed at the rear side of the sliding plate, the second spring is located inside the pull rod, and the rear end of the second spring penetrates into the rear side of the positioning plate.
[0011] A further improvement of this utility model is that: dust curtains are fixedly installed on the top front and rear sides of the inner wall of the preheating box; air outlets are opened on the left and right sides of the preheating box; the height and width of the positioning plate are smaller than the inner cavity of the preheating box; and several elastic plates are fixedly installed on the left and right sides of the inner wall of the drying box, with the elastic plates on the left and right sides being staggered.
[0012] A further improvement of this utility model is that: a movable baffle is hinged to the top and last side of the inner wall of the drying oven; limit baffles are fixedly installed on the rear sides of the left and right sides of the inner wall of the drying oven; the front side of the movable baffle is in contact with the rear side of the limit baffle; a wind box penetrating its inner cavity is fixedly installed on the top rear side of the drying oven; a guide fan is provided in the inner cavity of the wind box; a hot air recovery pipe is fixedly connected to the top of the wind box; and the other end of the hot air recovery pipe extends into the inner cavity of the preheating box.
[0013] Due to the adoption of the above technical solution, the technological progress achieved by this utility model compared to the prior art is as follows:
[0014] 1. This utility model provides a drying device for surface treatment of metal products. By setting a guide funnel frame on the front side of the positioning plate, hot air is concentrated and introduced into the positioning slot to accurately cover the grooves and holes of the slide rail parts. At the same time, the slide rail parts are rotated by a turntable, so that the hot air can evenly contact all surfaces of the workpiece, eliminating dead corners and allowing the hot air to forcefully penetrate the internal structure of the workpiece, ensuring that the coating film in complex areas such as deep grooves and bends is completely cured, and ensuring the drying quality of the drawer slide rail parts.
[0015] 2. This utility model provides a drying device for surface treatment of metal products. By setting a wind box guide fan at the tail of the drying box to extract residual hot air, and using a hot air recovery pipe to transport the waste heat to the preheating box to preheat newly entered workpieces, the waste heat is recovered for the preheating stage, reducing the energy consumption of cavity heating and solving the problem of heat energy waste. At the same time, the outlet is automatically closed by the movable baffle to reduce the heat loss of the drying box, and the hot air residence time is extended by the use of staggered elastic plates to improve the heat exchange efficiency. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0017] Figure 2 This is a schematic diagram of the conveying mechanism of the present invention;
[0018] Figure 3 This is a schematic diagram of the positioning mechanism for the slide rail parts of this utility model.
[0019] Figure 4 This utility model Figure 3 Enlarged schematic diagram of point A in the middle;
[0020] Figure 5 This is a schematic cross-sectional view of the bottom of the positioning plate of this utility model structure;
[0021] Figure 6 This is a cross-sectional schematic diagram of the drying box and preheating box of this utility model;
[0022] Figure 7 This is a cross-sectional schematic diagram of the bellows structure of this utility model.
[0023] In the diagram: 1. Drying oven; 11. Air inlet duct; 12. Elastic plate; 13. Limiting baffle; 14. Movable baffle; 15. Air box; 151. Guide fan; 16. Hot air recovery pipe; 2. Conveying mechanism; 21. Conveyor belt; 22. Positioning plate; 23. Positioning hole; 24. Slide rail parts positioning mechanism; 241. Positioning upright plate; 2411. Slot; 2412. Slide plate; 2413. Insert rod; 2414. 2415. Pull rod; 242. Spring 2; 243. Positioning slot; 244. Guide funnel frame; 244. Horizontal support; 2441. Turntable; 2442. Fixed hanging plate; 2443. Fixed slide rod; 2444. Limiting plate; 2445. Spring 1; 2446. Sliding clamp; 245. Slide rail body; 3. Hot air heater; 31. Air supply duct; 4. Preheating box; 41. Dustproof curtain; 42. Air outlet. Detailed Implementation
[0024] To make the technical means, creative features, objectives and effects of this utility model easier to understand
[0025] Understood. The present invention will now be further described in conjunction with specific implementation methods.
[0026] like Figure 1 As shown, this utility model provides a drying device for surface treatment of metal products, including a drying box 1. A conveying mechanism 2 is arranged through the inner cavity of the drying box 1. A preheating box 4 is arranged on the front side of the top of the conveying mechanism 2. The preheating box 4 extends into the inner cavity of the drying box 1. The conveying mechanism 2 includes a conveyor belt 21, which extends through the inner cavity of the drying box 1. A hot air heater 3 is fixedly installed on the top of the drying box 1. The hot air heater 3 includes an electric heating tube and a fan. The fan can blow the air heated by the electric heating tube through the air outlet. Both air outlets of the hot air heater 3 are fixedly connected to air supply pipes 31. Air inlet pipes 11 that penetrate the inner cavity are fixedly installed on the front side of both the left and right ends of the drying box 1. The other ends of the two air supply pipes 31 are fixedly connected to the air inlet pipes 11 and penetrate the inner cavity.
[0027] When in use, by activating the hot air heater 3, the internal electric heating tube generates heat, which, together with the fan, sends hot air through the two air supply pipes 31 into the air inlet pipe 11 and into the inner cavity of the drying chamber 1, thereby heating and drying the inner cavity of the drying chamber 1.
[0028] like Figure 2 , Figure 3 , Figure 4 As shown, several positioning plates 22 are uniformly fixedly installed on the outer wall of the conveyor belt 21. Each positioning plate 22 has a through-hole 23. A slide rail component positioning mechanism 24 is provided on the top of each positioning plate 22. The slide rail component positioning mechanism 24 includes a positioning upright plate 241. Several through-hole positioning placement grooves 242 are provided on the top of the positioning upright plate 241. A slide rail component body 245 is provided in the inner cavity of each positioning placement groove 242. Several guide funnel frames 243 communicating with the positioning placement grooves 242 are fixedly installed on the front side of the positioning upright plate 241. A horizontal support 244 is provided on the top of the positioning placement grooves 242. The horizontal support 244 is fixedly installed on the top of the positioning upright plate 241. A turntable 2441 is rotatably connected to the bottom of the horizontal support 244. A fixed hanging plate 2442 is fixedly installed on the bottom right side of the turntable 2441. A fixed slide rod 2443 is fixedly installed on the left side of the plate 2442. A limiting plate 2444 is fixedly installed on the left end of the fixed slide rod 2443. A spring 2445 is fixedly installed at the eccentric position on the right side of the limiting plate 2444. A sliding clamping plate 2446 is slidably installed on the outer wall of the fixed slide rod 2443. The left side of the sliding clamping plate 2446 is fixedly connected to the right end of the spring 2445. The slide rail part body 245 is clamped between the opposing surfaces of the fixed hanging plate 2442 and the sliding clamping plate 2446. A high-temperature resistant silicone pad with a thickness of 1-2mm and a temperature resistance of ≥250℃ is covered on the clamping surfaces of the fixed hanging plate 2442 and the sliding clamping plate 2446. The elastic buffer of the silicone pad can disperse the clamping pressure and prevent the metal clamping plate from directly contacting the electrophoretic layer. At the same time, the clamping points can be set on the mounting holes, reinforcing ribs, and other non-functional surfaces of the slide rail part body 245, avoiding the main appearance surface and the friction track surface, so as to avoid affecting the drying quality.
[0029] The conveyor belt 21 of the conveyor mechanism 2 passes through the inner cavity of the drying chamber 1. The slide rail component body 245 can be fed into the inner cavity of the drying chamber 1 for drying using the slide rail component positioning mechanism 24 fixed above several positioning plates 22. When installing the positioning plate 241, the slide rail component body 245 can be placed inside the positioning slot 242, and then the sliding clamp 2446 can slide on the outer wall of the fixed slide rod 2443 to compress the spring 2445. The rebound force of 45 allows the sliding clamp 2446 to clamp and fix the slide rail component body 245 between the fixed hanging plate 2442 and the sliding clamp 2446. Simultaneously, when the fixed slide rail component body 245 is conveyed backward into the drying chamber 1, hot air can be concentrated and blown into the positioning slot 242 through several guide funnel frames 243 to dry each slide rail component body 245. Furthermore, during the blowing motion, the rotational connection between the turntable 2441 and the horizontal support 244 allows the slide rail component body 245 to... 45. The air outlet of the guide funnel frame 243 is directly facing the lateral area or groove edge, hole edge, and other specific structural features of the slide rail part body 245 in the positioning slot 242. When the hot air is concentrated and introduced through the guide funnel frame 243, an asymmetrical impact is formed: the hot air mainly acts on the surface or local structure of the slide rail part body 245 facing the guide funnel frame 243, rather than uniformly covering the entire symmetrical surface. The impact force of this unilateral or eccentric airflow generates an unbalanced rotational torque at the workpiece axis. This torque continues to act and is sufficient to overcome the static friction and small rotational resistance of the bearing between the turntable 2441 and the horizontal support 244, driving the turntable 2441 together with the slide rail part body 245 clamped below it to rotate continuously around the vertical axis. During the rotation, the various surfaces of the slide rail part body 245, such as the deep groove, the inner wall of the hole, and the bend, are successively exposed to the mainstream of the directional hot air, achieving uniform drying without dead angles, thereby improving the drying uniformity of each slide rail part body 245.
[0030] like Figure 5 As shown, the bottom of the positioning plate 241 is provided with a slot 2411, which is engaged with the positioning plate 22. The positioning plate 241 is provided with a positioning control compartment, which is located on the rear side of the slot 2411. A slide plate 2412 is slidably installed in the inner cavity of the positioning control compartment. A rod 2413 is fixedly installed at the front end of the slide plate 2412. The front end of the rod 2413 passes through the inner cavity of the slot 2411 and engages with the positioning hole 23. A pull rod 2414 and a second spring 2415 are fixedly installed on the rear side of the slide plate 2412. The second spring 2415 is located inside the pull rod 2414, and the rear end of the second spring 2415 passes through the rear side of the positioning plate 241.
[0031] When installing the positioning plate 241, simply pull the lever 2414 to move the slide plate 2412 and the insert rod 2413 backward and compress the spring 2415. Then, the positioning plate 241, which has already been installed with the slide rail body 245, can be inserted into the positioning plate 22 on the top of the conveyor belt 21 using the slot 2411. This will align the insert rod 2413 with the positioning hole 23 on the positioning plate 22. After releasing the lever 2414, the insert rod 2413 will quickly insert into the positioning hole 23 under the rebound action of the spring 2415, thus fixing the entire positioning plate 241. When the entire positioning plate 241 needs to be removed after drying, simply pull the lever 2414.
[0032] like Figure 6 , Figure 7 As shown, dust curtains 41 are fixedly installed on the top front and rear sides of the inner wall of the preheating box 4. Air outlets 42 are opened on both the left and right sides of the preheating box 4. The height and width of the positioning plate 241 are smaller than the inner cavity of the preheating box 4. Several elastic plates 12 are fixedly installed on both the left and right sides of the inner wall of the drying box 1. These elastic plates 12 are staggered and are made of silicone rubber, a high-temperature, pressure-resistant, and elastic material that can maintain elasticity within a temperature range of -60℃ to 250℃. A movable baffle 14 is hinged to the top rear side of the inner wall of the drying box 1. Limiting baffles 13 are fixedly installed on the rear of both the left and right sides. The front side of the movable baffle 14 fits against the rear side of the limiting baffle 13. The movable baffle 14 is made of solid heat-resistant material and has a certain weight so that it will not be blown up by hot air. A wind box 15 that runs through its inner cavity is fixedly installed on the rear top of the drying box 1. A guide fan 151 is installed in the inner cavity of the wind box 15. A hot air recovery pipe 16 is fixedly connected to the top of the wind box 15. The other end of the hot air recovery pipe 16 runs through the inner cavity of the preheating box 4. The outer walls of the hot air recovery pipe 16, the drying box 1, and the preheating box 4 are all wrapped with heat insulation cotton to prevent heat loss.
[0033] When the slide rail component positioning mechanism 24 moves backward on top of the conveyor belt 21, it first passes through the front dust curtain 41 installed in the preheating box 4 and enters the inner cavity of the preheating box 4. Then, it passes through the rear dust curtain 41 of the inner cavity of the preheating box 4 and enters the inner cavity of the drying box 1. Utilizing the overall fixing effect of the slide rail component positioning mechanism 24, it can compress the elastic plate 12 when passing through it. After the slide rail component positioning mechanism 24 has completely passed through the elastic plate 12, the elastic plate 12 can recover by its own elasticity. When the air source enters the inner cavity of the drying box 1 through the air inlet pipe 11, it will blow backward. The airflow can increase the residence time when passing through the staggered elastic plates 12, ensuring the proper positioning of the slide rail component 24. The drying effect of 4 is achieved by the sliding rail parts positioning mechanism 24 moving to the end, which can lift the movable baffle 14 as a whole. After it is completely removed from the drying box 1, the movable baffle 14 can be reset under the action of gravity and stop against the limit baffle 13 to prevent a large amount of heat loss from the inner cavity of the drying box 1. The hot air blown into the inner cavity of the drying box 1 can be guided to the inner cavity of the hot air recovery pipe 16 by starting the guide fan 151 in the air box 15, and then blown into the inner cavity of the preheating box 4 through the hot air recovery pipe 16, so as to preheat and dry the sliding rail parts body 245 that has just entered the inner cavity of the preheating box 4, avoiding the waste of hot air. Finally, the remaining excess air source can be discharged through the air outlet 42.
[0034] The working principle of the drying device for surface treatment of metal products will be explained in detail below.
[0035] like Figure 1-7As shown, during use, the hot air heater 3 is activated, and the internal electric heating element generates heat. This, combined with a fan, directs hot air through two air supply pipes 31 into the air inlet pipe 11, which then enters the inner cavity of the drying chamber 1, thus heating and drying the interior. Simultaneously, the conveyor belt 21 of the conveying mechanism 2 passes through the inner cavity of the drying chamber 1. The slide rail component body 245 is fed into the inner cavity of the drying chamber 1 for drying using the slide rail component positioning mechanism 24 fixed above several positioning plates 22. When installing the positioning plate 241, the slide rail component body 245 is first placed inside the positioning slot 242, and then the sliding clamp 2446 slides on the outer wall of the fixed slide rod 2443, compressing the spring 2445. The spring 2445 then... The rebound force of 45 allows the sliding clamp 2446 to clamp and fix the slide rail component body 245 between the fixed hanging plate 2442. Simultaneously, when the fixed slide rail component body 245 is conveyed backward into the drying chamber 1, hot air can be concentrated and blown into the positioning slot 242 through several guide funnel frames 243 to dry each slide rail component body 245. Furthermore, the rotational connection between the turntable 2441 and the horizontal support 244 during blowing allows the entire slide rail component body 245 to rotate, thereby improving the drying uniformity of each slide rail component body 245. Additionally, each time the positioning plate 241 is installed, simply pull the pull rod 2414 to move the slide plate 2412 along with the insertion rod 2413 backward, and the spring 2415... After compression, the positioning plate 241, with the slide rail component body 245 already installed, can be inserted into the positioning plate 22 on the top of the conveyor belt 21 using the slot 2411. This aligns the insertion rod 2413 with the positioning hole 23 on the positioning plate 22. After releasing the pull rod 2414, the insertion rod 2413 will quickly insert into the positioning hole 23 under the rebound action of the spring 2415, thus fixing the entire positioning plate 241. When the drying process is complete and the entire positioning plate 241 needs to be removed, the pull rod 2414 can be pulled in the same way. When the slide rail component positioning mechanism 24 moves backward on the top of the conveyor belt 21, it will first pass through the front dustproof curtain 41 installed in the preheating box 4 and enter the inner cavity of the preheating box 4, and then pass through the dustproof curtain on the rear side of the inner cavity of the preheating box 4. After curtain 41 enters the inner cavity of drying chamber 1, the overall fixing effect of the slide rail positioning mechanism 24 compresses the elastic plate 12 as it passes over it. Once the slide rail positioning mechanism 24 has completely passed the elastic plate 12, the elastic plate 12 recovers due to its own elasticity. When the air source enters the inner cavity of drying chamber 1 through the air inlet pipe 11, it blows backward. The airflow increases its residence time as it passes over the staggered elastic plates 12, ensuring a better drying effect on the slide rail positioning mechanism 24. When the slide rail positioning mechanism 24 reaches its final position, it lifts the movable baffle 14. After completely exiting drying chamber 1, the movable baffle 14 resets under gravity and stops against the limiting baffle 13, preventing excessive heat loss from the inner cavity of drying chamber 1.The last hot air blown into the drying chamber 1 can be guided by the guide fan 151 inside the air box 15 to the inner cavity of the hot air recovery pipe 16, and then blown into the inner cavity of the preheating chamber 4 through the hot air recovery pipe 16. This preheats and dries the slide rail parts 245 that have just entered the preheating chamber 4, avoiding waste of hot air. The remaining excess air can then be discharged through the air outlet 42.
[0036] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.
Claims
1. A drying apparatus for surface treatment of metal products, comprising a drying chamber (1), characterized in that: A conveying mechanism (2) is provided through the front and back of the inner cavity of the drying box (1). A preheating box (4) is provided on the top front side of the conveying mechanism (2). The preheating box (4) extends into the inner cavity of the drying box (1). The conveying mechanism (2) includes a conveyor belt (21). The conveyor belt (21) extends through the inner cavity of the drying box (1). Several positioning plates (22) are uniformly fixedly installed on the outer wall of the conveyor belt (21). Each of the positioning plates (22) has a positioning hole (23) that extends through the front and back. Each of the positioning plates (22) is provided with a slide rail component positioning mechanism (24) at its top. The slide rail component positioning mechanism (24) includes a positioning plate (241). The top of the positioning plate (241) is provided with several positioning placement slots (242) that are open from front to back. The inner cavity of each of the positioning placement slots (242) is provided with a slide rail component body (245). Several flow guide funnel frames (243) that are open from front to back are fixedly installed on the front side of the positioning plate (241).
2. The drying apparatus for surface treatment of metal products according to claim 1, characterized in that: A hot air heater (3) is fixedly installed on the top of the drying box (1). Both air outlets of the hot air heater (3) are fixedly connected to air supply pipes (31). Both the left and right front sides of the drying box (1) are fixedly installed with air inlet pipes (11) that penetrate their inner cavities. The other ends of the two air supply pipes (31) are fixedly connected to the air inlet pipes (11) and penetrate their inner cavities.
3. The drying apparatus for surface treatment of metal products according to claim 1, characterized in that: A horizontal support (244) is provided on the top of several positioning slots (242). The horizontal support (244) is fixedly installed on the top of the positioning plate (241). A turntable (2441) is rotatably connected to the bottom of the horizontal support (244). A fixed hanging plate (2442) is fixedly installed on the bottom right side of the turntable (2441). A fixed sliding rod (2443) is fixedly installed on the left side of the fixed hanging plate (2442). 3) A limiting plate (2444) is fixedly installed on the left end. A spring (2445) is fixedly installed on the right eccentric part of the limiting plate (2444). A sliding clamp (2446) is slidably installed on the outer wall of the fixed slide rod (2443). The left side of the sliding clamp (2446) is fixedly connected to the right end of the spring (2445). The slide rail part body (245) is clamped between the opposite surfaces of the fixed hanging plate (2442) and the sliding clamp (2446).
4. The drying apparatus for surface treatment of metal products according to claim 1, characterized in that: The bottom of the positioning plate (241) is provided with a slot (2411), which is engaged with the positioning plate (22). The positioning plate (241) is provided with a positioning control compartment, which is located on the rear side of the slot (2411). A sliding plate (2412) is slidably installed in the inner cavity of the positioning control compartment. A plug rod (2413) is fixedly installed at the front end of the sliding plate (2412). The front end of the plug rod (2413) penetrates into the inner cavity of the slot (2411) and engages with the positioning hole (23). A pull rod (2414) and a second spring (2415) are fixedly installed on the rear side of the sliding plate (2412). The second spring (2415) is located inside the pull rod (2414), and the rear end of the second spring (2415) penetrates into the rear side of the positioning plate (241).
5. A drying apparatus for surface treatment of metal products according to claim 1, characterized in that: Dustproof curtains (41) are fixedly installed on the top front and rear sides of the inner wall of the preheating box (4). Air outlets (42) are opened on the left and right sides of the preheating box (4). The height and width of the positioning plate (241) are smaller than the inner cavity of the preheating box (4). Several elastic plates (12) are fixedly installed on the left and right sides of the inner wall of the drying box (1). The several elastic plates (12) on the left and right sides are staggered.
6. The drying apparatus for surface treatment of metal products according to claim 1, characterized in that: A movable baffle (14) is hinged to the top of the inner wall of the drying box (1). Limiting baffles (13) are fixedly installed on the rear of the left and right sides of the inner wall of the drying box (1). The front side of the movable baffle (14) is attached to the rear side of the limiting baffle (13). A wind box (15) penetrating its inner cavity is fixedly installed on the rear top of the drying box (1). A guide fan (151) is provided in the inner cavity of the wind box (15). A hot air recovery pipe (16) is fixedly connected to the top of the wind box (15). The other end of the hot air recovery pipe (16) penetrates into the inner cavity of the preheating box (4).