Electromagnetic heat treatment furnace and closed-loop control method

Abstract

The invention discloses an electromagnetic heat treatment furnace which comprises a furnace body mounted on a bracket and a water tank beside the bracket, the furnace body is provided with an inverted furnace cover, the support is further provided with a lifting mechanism, and the lifting mechanism drives the furnace cover to ascend and descend. A rail extending to the bottom of the furnace body is arranged below the water tank, and a driving mechanism is arranged on the rail to drive the water tank to move to the position below the furnace body along the rail. The invention further discloses a working method of the electromagnetic heat treatment furnace. The invention has the characteristics of fast temperature rise, accurate temperature control, low power consumption and low power distribution requirement.

Description

Technical Field

[0001] The invention belongs to the technical field of heat treatment of alloy metals, and relates to an electromagnetic heat treatment furnace and a closed-loop control method. Background Art

[0002] A heat treatment furnace refers to an electric furnace or a fuel furnace for heating furnace charges for heat treatment. Commonly used heat treatment furnaces include box-type resistance furnaces, pit-type resistance furnaces, gas carburizing furnaces, and salt bath furnaces, etc. Usually, a continuous furnace is used. Workpieces are continuously loaded through the charging door, pass through the furnace chamber, and are continuously unloaded through the discharging door. Generally, the common conveying method inside the furnace is to place the workpieces on heat-resistant steel guide rails and transfer them by a step-type moving beam or a pusher. The T6 process is a heat treatment process, that is, the state of artificial aging after solution heat treatment. It can be used for wrought aluminum alloys and cast aluminum alloys. The main factors are solution temperature, quenching rate (determined by the quenching medium), aging temperature, holding time, and aging stages (single-stage aging or multi-stage aging).

[0003] At present, for aluminum alloy heat treatment furnaces on the market, some use electric heating and some use natural gas heating. Most of them use the form of resistance heating for heat supply, and the minimum power requirement is above 200 kw, and most of them use a power of about 300 kw. Such furnaces have high energy consumption requirements, and are extremely large in volume and floor area. If a manufacturing factory purchases such a furnace, in addition to the need to re-transform the workshop, it is also necessary to record and transform the power distribution equipment. This limits most potential purchasing users. In addition, the existing heat treatment furnace relies on resistance heating to heat the workpieces inside the furnace, but the thermal energy utilization rate is low. In the resistance furnace, the temperature at the upper part inside the furnace is high and the temperature at the lower part is low, while the workpieces are in the area with a low temperature at the lower part, which causes the heat at the upper part to be completely wasted. Moreover, with the existing heat treatment furnace, the process is complex and the efficiency is low, and the production efficiency can no longer be improved. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the invention provides an electromagnetic heat treatment furnace and a closed-loop control method, which have low energy consumption and high thermal energy utilization rate; the form of electromagnetic heating is selected, and the temperature rise is significantly improved compared with the resistance furnace, and the power requirement is reduced. Coupled with the structural design of using a scroll fan to achieve internal circulation, the heat inside the furnace is fully utilized.

[0005] To solve the above technical problems, the invention is solved by the following technical solutions: An electromagnetic heat treatment furnace includes a furnace body installed on a bracket and a water tank beside the bracket; the furnace body is provided with an inverted furnace cover, and a lifting mechanism is also provided on the bracket, and the lifting mechanism drives the furnace cover to lift; a track extending to the bottom of the furnace body is arranged below the water tank, and a driving mechanism is arranged on the track to drive the water tank to move along the track to below the furnace body.

[0006] Preferably, the lifting mechanism includes a positioning component and a piston component. The piston component is provided with a bottom support for placing the furnace cover. The positioning component includes a positioning rod and a safety bolt. The positioning rod is provided with a plurality of positioning holes and is connected to the bottom support at the bottom. The positioning component drives the safety bolt to insert into the positioning hole so that the positioning rod cannot move, thereby realizing the positioning and locking operation.

[0007] Preferably, an electromagnetic induction coil is provided on the outer wall of the furnace body and a partition is provided in the inner cavity. After the electromagnetic induction coil is energized, it acts on the furnace wall to generate heat. A heating channel is formed between the partition and the inner wall. A scroll fan is provided at the top inside the furnace body; the top of the heating channel is an air inlet, and the bottom is an air outlet, and the air outlet is aligned with the workpiece on the furnace cover; a plurality of temperature measuring probes are provided on the inner wall of the furnace body, the heating channel and the partition; an auxiliary coil is provided on the outer wall of the furnace body in the space where the scroll fan is located.

[0008] Preferably, the water tank is hinged with a tank cover. The side wall of the bracket is provided with a vertical rail and the lower end forms an outward arc section. The front end of the tank cover is provided with a roller. When the water tank moves towards the bottom of the furnace body, the roller acts on the arc section and rolls along the vertical rail, causing the tank cover to flip; a plurality of temperature measuring probes are provided in the water tank; a plurality of induction coils are provided on the side wall of the water tank, and a plurality of heating rods are rotatably provided on the tank cover.

[0009] A closed-loop control method for an electromagnetic heat treatment furnace. Step 1: The positioning component pulls out the safety bolt, the piston component starts, extends the piston rod to lower the bottom support to a low position, and then the positioning component inserts the safety bolt into the positioning hole. Step 2: A forklift or robot places the furnace cover on the bottom support, and then places the workpiece on the furnace cover. Step 3: The positioning component pulls out the safety bolt again, the piston component starts, retracts the piston rod to raise the bottom support until the furnace cover closes the opening at the bottom of the furnace body, and then the positioning component inserts the safety bolt into the positioning hole to achieve locking. Step 4: The electromagnetic induction coil on the furnace body is powered on, generating electromagnetic induction to drive the inner wall of the furnace body to generate heat, and at the same time the vortex fan starts to work to realize the circulation of the air flow in the furnace until the heat treatment is completed. Step 5: The driving mechanism drives the water tank to move along the track to below the furnace body, and at the same time the tank cover automatically flips. When it reaches below the furnace body, the tank cover is fully opened. Step 6: The positioning component pulls out the safety bolt, the piston component starts, extends the piston rod to lower the bottom support until the furnace cover and the workpiece are both submerged in the cooling medium in the water tank, and then the positioning component inserts the safety bolt into the positioning hole, keeps the workpiece immersed in water for a period of time and then proceeds to the next step. Step 7: The positioning component pulls out the safety bolt, the piston component starts, raises the furnace cover and the workpiece out of the cooling medium, and then the positioning component inserts the safety bolt into the positioning hole for locking to perform the draining work. Step 8: The lifting mechanism cooperates to send the workpiece into the furnace body again and locks it. Aging treatment is carried out in the furnace again, and then the driving mechanism drives the water tank back to its original position. Step 9: After the aging treatment is completed, the lifting mechanism lowers the furnace cover and the workpiece to a low position and locks them. The forklift or robot transports the furnace cover and the workpiece away together, places another furnace cover on the bottom support, and then places the workpiece to perform the next heat treatment cycle work.

[0010] In the above technical solution, in Step 4, the temperature inside the furnace body is controlled at 520 degrees Celsius to 550 degrees Celsius, and the holding time of the workpiece at this temperature is 7 to 11 hours.

[0011] In the above technical solution, in Step 6, the lifting mechanism transports the workpiece from inside the furnace body to the water tank within 30 seconds, and controls the water temperature in the water tank at 65 to 90 degrees Celsius, and keeps it in the water tank for 10 to 20 minutes; in Step 7, the draining time of the workpiece above the water tank is kept within half an hour.

[0012] In the above technical solution, in Step 8, the aging temperature inside the furnace body is controlled at 160 to 180 degrees Celsius, and the time is 5 - 8 hours.

[0013] In the above technical solution, during the furnace body heating-up stage, the coils and the circulating vortex fans on the furnace body operate at full power to accelerate heating and ensure uniform temperature everywhere inside the furnace; during the furnace body heat preservation stage, the auxiliary coils carry out heating work, and the vortex fans rotate to drive the air flow to circulate, thereby ensuring uniform temperature everywhere inside the furnace; during the water tank heating-up stage, the induction coil and the heating rod are used for heating simultaneously, and during the working stage when the water tank moves below the furnace body, the induction coil is used to maintain the temperature.

[0014] Preferably, in step four, the temperature inside the furnace body is controlled at 535 degrees Celsius with an upper and lower error within 5 degrees Celsius, and the heat preservation time is 8 to 10 hours; the water discharging time is within 15 seconds, the temperature of the cooling medium is 75 to 85 degrees Celsius, the immersion time is 15 minutes, and the draining time is 20 minutes; the aging temperature in step eight is 165 to 175 degrees Celsius, and the aging time is 6 hours.

[0015] The present invention provides an electromagnetic heat treatment furnace, which is designed with a circulating air duct structure inside the furnace body and uses vortex fans to drive the internal circulation; it is designed with two sets of main and auxiliary electromagnetic induction coils for heating. A water tank heated by electromagnetic induction is also arranged outside, and the temperature is raised with the assistance of an electric heating rod on the tank cover. The present invention also provides a closed-loop method for this furnace, which is simple to operate, has a clear logic, significantly reduces the process steps compared with the existing reaction furnace, simplifies the process, and improves the efficiency. The present invention has the characteristics of fast heating, accurate temperature control, low power consumption, and low power distribution requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will discuss the drawings required to be used in the description of the embodiments or the prior art. Obviously, the technical solutions described in conjunction with the drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other embodiments and their drawings can be obtained according to these embodiments shown in the drawings.

[0017] Figure 1 is a perspective view of the present invention.

[0018] Figure 2 is a schematic diagram of the external structure of the furnace body of the present invention.

[0019] Figure 3 is a schematic diagram of the structure of the lifting mechanism of the present invention.

[0020] Figure 4 is a schematic cross-sectional view of the furnace body structure of the present invention.

[0021] Figure 5 is a schematic diagram of the water tank of the present invention.

[0022] Figure 6It is the structural bottom view of the lid of the present invention.

[0023] In the figure: support 1, vertical rail 11, furnace body 2, furnace lid 21, vortex fan 22, heating channel 23, water tank 3, rail 31, lid 32, roller 33, heating rod 34, lifting mechanism 4, positioning component 41, piston component 42. Detailed implementation manners

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments described in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope protected by the present invention.

[0025] As shown in the attached Figure 1 to the attached Figure 6 As shown, this embodiment discloses an electromagnetic heat treatment furnace, including a furnace body 2 installed on a support 1 and a water tank 3 beside the support 1; the furnace body 2 is provided with an inverted furnace lid 21, and a lifting mechanism 4 is also provided on the support 1, and the lifting mechanism 4 drives the furnace lid 21 to lift; a rail 31 extending to the bottom of the furnace body 2 is provided below the water tank 3, and a driving mechanism is provided on the rail 31 to drive the water tank 3 to move along the rail to below the furnace body 2.

[0026] The electromagnetic heat treatment furnace of the present invention is internally designed with a circulating air duct structure, and the vortex fan is used for driving to achieve internal circulation; and two sets of electromagnetic induction coils are designed for heating. The specific structure is as follows: an electromagnetic induction coil is provided on the outer wall of the furnace body 2 and a partition is provided in the inner cavity. After the electromagnetic induction coil is energized, it acts on the furnace wall to generate heat. A heating channel is formed between the partition and the inner wall. A vortex fan is provided at the top inside the furnace body 2; the top of the heating channel is the air inlet, and the bottom is the air outlet, and the air outlet is aligned with the workpiece on the furnace lid; a plurality of temperature measuring probes are provided on the inner wall of the furnace body 2, the heating channel and the partition; an auxiliary coil is provided on the outer wall of the furnace body 2 in the space where the vortex fan is located.

[0027] The electromagnetic heat treatment furnace of the present invention has the characteristics of fast heating, accurate temperature control, low power consumption and low power distribution requirements. Using electromagnetic induction heating, compared with the existing resistance type, it has the advantage of high thermal conversion rate. The present invention is provided with a coil for electromagnetic induction heating outside the furnace body 2 to perform full-load heating in a short time, and is equipped with an auxiliary coil, and in combination with the internal circulation structure design, it can quickly and accurately reach the required temperature. After the temperature inside the furnace reaches the required temperature for heat treatment, the coil outside the furnace body 2 is turned off, and only the auxiliary coil on the furnace lid is retained for heating, and in combination with the internal circulation of air flow heating, the power consumption can be greatly reduced.

[0028] On this basis, a complete heat insulation design is also set up. Therefore, the thermal energy utilization rate of this device is high, and the required power consumption can be reduced again. A heat insulation layer is covered on the outer wall of the furnace body 2 of this device, and a heat insulation layer is also provided at the furnace cover 21. After the furnace cover 21 is closed, the entire heat treatment furnace is covered with a heat insulation layer, so as to maximize the reduction of heat loss. By using the internal circulation air flow design, combined with the cooperative heating work of the main and auxiliary electromagnetic induction coils, and supplemented by a complete full-coverage heat insulation design, the power consumption of the whole machine can be greatly reduced on the premise of meeting the excellent heat treatment process requirements of the workpiece.

[0029] At present, the power consumption of resistance heating furnaces is basically above 200kw, and even reaches or exceeds 300kw; while this device adopts the electromagnetic induction heating method with high heat conversion rate under the condition of meeting the T6 heat treatment process of aluminum alloy parts, and the power consumption requirement can be lower than 200kw. The reduction of power consumption requirement can reduce the power distribution requirement of this device and meet the actual needs of more small and medium-sized enterprises.

[0030] In order to provide excellent heat treatment effect, it is necessary to precisely control the temperature inside the furnace body 2. Therefore, several temperature measuring probes are set in each area inside the furnace body of this device. It is necessary to monitor the temperature of the air flow used for heating in the heating channel 23, and also monitor the air temperature in the space where the workpiece is located inside the furnace body 2. By comparing the monitored temperature with the temperature required for heat treatment, the working states and parameters of the two groups of coils and the vortex fan 31 can be judged. In addition, the heating channel 23 is divided into multiple independent air flow channels by baffles, and flow valves are set on the air inlets corresponding to each air flow channel to control the air flow. Combined with the above-mentioned temperature measuring probes, the purpose of precise zone independent temperature control is achieved. The flow valves of each channel of this device independently control the circulation flow to achieve local independent temperature control, ensure the overall temperature balance in the furnace, and thus ensure the performance balance and good consistency of the workpieces in the furnace after heat treatment.

[0031] The furnace body 2 and the furnace cover 21 are separated and adopt an inverted structure. Therefore, a lifting mechanism is also set up for this device. The lifting mechanism 4 includes a positioning component 41 and a piston component 42. The piston component 42 is provided with a bottom support for placing the furnace cover 21. The positioning component 41 includes a positioning rod and a safety bolt. A number of positioning holes are provided on the positioning rod and the bottom is fixedly connected to the bottom support. The positioning component 41 is also provided with a driving device that can drive the safety bolt to insert into the positioning hole so that the positioning rod cannot move, thereby realizing the positioning and locking work. This driving device is selected from a linear motor, a hydraulic pump or a cylinder.

[0032] Among them, the piston assembly can be driven by an oil cylinder, featuring strong load-bearing capacity and the advantages of fast and stable lifting speed. The furnace cover 21 is designed as an inverted furnace cover and also serves as a workpiece placement rack, thus reducing operation inconvenience and shortening the operation cycle. The piston assembly can also use an air pump to drive the piston rod to move by means of air pressure.

[0033] The water tank 3 is hinged with a tank cover 32. The side wall of the bracket 1 is provided with a vertical rail 11 and the lower end forms an outward arc section. The front end of the tank cover 32 is provided with rollers 33. When the water tank 3 moves towards the bottom of the furnace body 2, the rollers 33 act on the arc section and roll along the vertical rail 11, causing the tank cover 32 to flip. A number of temperature measurement probes are arranged inside the water tank. A number of induction coils are arranged on the side wall of the water tank 3, and a number of heating rods 34 are rotatably arranged on the tank cover. In addition to electromagnetic induction heating, the heating rods 4 are also used for auxiliary heating.

[0034] In addition, heat insulation layers are covered on both the outer wall of the water tank 3 and the tank cover 32, which can prevent heat loss and thus reduce energy consumption. A stopper is arranged on the track 31 to limit the moving stroke of the water tank 3. After the water tank 3 triggers the stopper, the driving force for driving the water tank 3 to move is stopped.

[0035] The water tank has a large volume, so there will be temperature differences in each area. Areas are divided on the outer wall of the water tank 3, and one induction coil is arranged in each area for heating. The temperature measurement probes are used to detect the temperatures of each area inside the water tank. When the requirements are not met, the power of the coil corresponding to this area can be changed. In this way, the uniformity of the medium temperature inside the tank can be ensured, and the consistency of the products in the same batch can be improved.

[0036] The present invention also discloses a closed-loop control method for an electromagnetic heat treatment furnace, which includes the following steps: Step 1, the positioning component pulls out the safety bolt, the piston component starts, extends the piston rod to lower the bottom support to a low position, and then the positioning component inserts the safety bolt into the positioning hole; Step 2, a forklift or a robot places the furnace cover on the bottom support, and then places the workpiece on the furnace cover; Step 3, the positioning component pulls out the safety bolt again, the piston component starts, retracts the piston rod to raise the bottom support until the furnace cover closes the opening at the bottom of the furnace body, and then the positioning component inserts the safety bolt into the positioning hole to achieve locking; Step 4, the electromagnetic induction coil on the furnace body is energized to generate electromagnetic induction to drive the inner wall of the furnace body to generate heat, and at the same time the vortex fan starts to work to realize the circulation of the air flow in the furnace until the heat treatment is completed; Step 5, the driving mechanism drives the water tank to move along the track to below the furnace body, and at the same time the tank cover automatically flips. When it reaches below the furnace body, the tank cover is fully opened; Step 6, the positioning component pulls out the safety bolt, the piston component starts, extends the piston rod to lower the bottom support until both the furnace cover and the workpiece sink into the cooling medium in the water tank, and then the positioning component inserts the safety bolt into the positioning hole. After keeping the workpiece immersed in water for a period of time, it enters the next step; Step 7, the positioning component pulls out the safety bolt, the piston component starts, raises the furnace cover and the workpiece out of the cooling medium, and then the positioning component inserts the safety bolt into the positioning hole for locking to perform the water draining work; Step 8, the lifting mechanism cooperates to send the workpiece into the furnace body again and lock it. Aging treatment is carried out in the furnace again, and then the driving mechanism drives the water tank back to its original position; Step 9, after the aging treatment is completed, the lifting mechanism lowers the furnace cover and the workpiece to a low position and locks them. The forklift or the robot transports the furnace cover and the workpiece away together, then places another furnace cover on the bottom support, and then places the workpiece to perform the next heat treatment cycle work.

[0037] In Step 4, the temperature inside the furnace body is controlled at 520 °C to 550 °C, and the holding time of the workpiece at this temperature is 7 to 11 hours.

[0038] In Step 6, the lifting mechanism transports the workpiece from inside the furnace body to the water tank within 30 seconds, and controls the water temperature in the water tank at 65 to 90 °C and keeps it in the water tank for 10 to 20 minutes; In Step 7, the water draining time of the workpiece above the water tank is kept within half an hour.

[0039] In Step 8, the aging temperature inside the furnace body is controlled at 160 to 180 °C, and the time is 5 - 8 hours.

[0040] During the heating-up stage of the furnace body, the coil and the circulating vortex fan on the furnace body work at full power to accelerate the heating-up and ensure the uniformity of the temperature everywhere inside the furnace; During the heat preservation stage of the furnace body, the auxiliary coil conducts heating work, and the vortex fan rotates to drive the air flow to circulate, thereby ensuring the uniformity of the temperature everywhere inside the furnace.

[0041] In Step Four, the temperature inside the furnace body is controlled at 535 degrees Celsius, with an upper and lower error within 5 degrees Celsius, and the heat preservation time is 8 to 10 hours; the water injection time is within 15 seconds, and the cooling medium temperature is 75 to 85 degrees Celsius, the immersion time is 15 minutes, and the draining time is 20 minutes; in Step Eight, the aging temperature is 165 to 175 degrees Celsius, and the aging time is 6 hours.

[0042] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0043] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electromagnetic heat treatment furnace, characterized in that: It includes a furnace body (2) installed on a bracket (1) and a water tank (3) beside the bracket (1); the furnace body (2) is provided with an inverted furnace cover (21), and a lifting mechanism (4) is also provided on the bracket (1), and the lifting mechanism (4) drives the furnace cover (21) to lift; a track (31) extending to the bottom of the furnace body (2) is provided below the water tank (3), and a driving mechanism is provided on the track (31) to drive the water tank (3) to move along the track to below the furnace body (2).

2. The electromagnetic heat treatment furnace according to claim 1, characterized in that: The lifting mechanism (4) includes a positioning component (41) and a piston component (42), the piston component (42) is provided with a bottom support for placing the furnace cover (21), the positioning component (41) includes a positioning rod and a safety bolt, the positioning rod is provided with a plurality of positioning holes and its bottom is connected to the bottom support, and the positioning component (41) drives the safety bolt to insert into the positioning hole so that the positioning rod cannot move, thereby realizing the positioning and locking work.

3. The electromagnetic heat treatment furnace according to claim 1, characterized in that: The outer wall of the furnace body (2) is provided with an electromagnetic induction coil and the inner cavity is provided with a partition board. After the electromagnetic induction coil is energized, it acts on the furnace wall to generate heat. A heating channel (23) is formed between the partition board and the inner wall. A scroll fan (22) is provided at the top inside the furnace body (2); the top of the heating channel (23) is an air inlet, and the bottom is an air outlet, and the air outlet is aligned with the workpiece on the furnace cover; a plurality of temperature measuring probes are provided on the inner wall of the furnace body (2), the heating channel (23) and the partition board; an auxiliary coil is provided on the outer wall of the furnace body (2) in the space where the scroll fan (22) is located.

4. The electromagnetic heat treatment furnace according to claim 1, characterized in that: The water tank (3) is hinged with a tank cover (32), a vertical rail (11) is provided on the side wall of the bracket (1) and the lower end forms an outward arc section, a roller (33) is provided at the front end of the tank cover (32), when the water tank (3) moves towards the bottom of the furnace body (2), the roller (33) acts on the arc section and rolls along the vertical rail (11) so that the tank cover (32) flips; a plurality of temperature measuring probes are provided inside the water tank; a plurality of induction coils are provided on the side wall of the water tank (3), and a plurality of heating rods (34) are rotatably provided on the tank cover.

5. A closed-loop control method for an electromagnetic heat treatment furnace, characterized in that: Step 1: The positioning component pulls out the safety bolt, the piston component starts, extends the piston rod to lower the bottom support to the low position, and then the positioning component inserts the safety bolt into the positioning hole. Step 2: A forklift or a robot places the furnace cover on the bottom support and then places the workpiece on the furnace cover. Step 3: The positioning component pulls out the safety bolt again, the piston component starts, retracts the piston rod to raise the bottom support until the furnace cover closes the opening at the bottom of the furnace body, and then the positioning component inserts the safety bolt into the positioning hole to achieve locking. Step 4: The electromagnetic induction coil on the furnace body is powered on, generating electromagnetic induction to drive the inner wall of the furnace body to generate heat. At the same time, the vortex fan starts to work to realize the circulating flow of the air flow in the furnace until the heat treatment is completed. Step 5: The driving mechanism drives the water tank to move along the track to below the furnace body, and at the same time, the tank cover automatically flips. When it reaches below the furnace body, the tank cover is fully opened. Step 6: The positioning component pulls out the safety bolt, the piston component starts, extends the piston rod to lower the bottom support until both the furnace cover and the workpiece sink into the cooling medium in the water tank, and then the positioning component inserts the safety bolt into the positioning hole. After keeping the workpiece immersed in water for a period of time, it enters the next step. Step 7: The positioning component pulls out the safety bolt, the piston component starts, raises the furnace cover and the workpiece out of the cooling medium, and then the positioning component inserts the safety bolt into the positioning hole for locking to perform the draining work. Step 8: The lifting mechanism cooperates to send the workpiece into the furnace body again and locks it. Aging treatment is carried out again in the furnace, and then the driving mechanism drives the water tank back to its original position. Step 9: After the aging treatment is completed, the lifting mechanism lowers the furnace cover and the workpiece to the low position and locks them. The forklift or the robot transports the furnace cover and the workpiece away together, places another furnace cover on the bottom support, and then places the workpiece to carry out the next heat treatment cycle work.

6. The closed-loop control method according to claim 5, characterized in that: In Step 4, the temperature inside the furnace body is controlled at 520 to 550 degrees Celsius, and the holding time of the workpiece at this temperature is 7 to 11 hours.

7. The closed-loop control method according to claim 6, wherein: In Step 6, the lifting mechanism transports the workpiece from inside the furnace body to inside the water tank within 30 seconds, and controls the water temperature in the water tank at 65 to 90 degrees Celsius and keeps it in the water tank for 10 to 20 minutes. In Step 7, the draining time of the workpiece above the water tank is kept within half an hour.

8. The closed-loop control method according to claim 7, wherein: In Step 8, the aging temperature inside the furnace body is controlled at 160 to 180 degrees Celsius, and the time is 5 - 8 hours.

9. The closed-loop control method according to claim 5, wherein: In the furnace body heating stage, the coil and the circulating vortex fan on the furnace body work at full power to accelerate heating and ensure uniform temperature everywhere inside the furnace. In the furnace body holding stage, the auxiliary coil conducts heating work, and the vortex fan rotates to drive the air flow to circulate, thereby ensuring uniform temperature everywhere inside the furnace. In the water tank heating stage, the induction coil and the heating rod are used for heating simultaneously. In the working stage when the water tank moves to below the furnace body, the induction coil is used to maintain the temperature.

10. The closed-loop control method according to claim 8, wherein: In step four, the temperature inside the furnace body is controlled at 535 degrees Celsius, with an upper and lower error within 5 degrees Celsius, and the heat preservation time is 8 to 10 hours; the water injection time is within 15 seconds, and the temperature of the cooling medium is 75 to 85 degrees Celsius, the immersion time is 15 minutes, and the draining time is 20 minutes; in step eight, the aging temperature is 165 to 175 degrees Celsius, and the aging time is 6 hours.

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