Heat treatment pusher furnace capable of carrying out carburizing diffusion, medium cooling and secondary heating processes

Abstract

A heat treatment push disc furnace capable of implementing carburizing diffusion, medium cooling and secondary heating processes, comprising a furnace body, a guide rail, a push disc moving mechanism, a gas circulation mechanism, a heating mechanism, a discharging mechanism, a cooling mechanism, an atmosphere supply mechanism and a waste gas discharge mechanism, the furnace body forms a furnace chamber and is provided with an inlet and an outlet at two ends, the inlet is connected with the outlet of a diffusion furnace and is provided with a sealed isolation furnace door, the guide rail, the gas circulation mechanism and the heating mechanism are respectively arranged at the bottom, the top and the two sides of the furnace chamber, the push disc moving mechanism and the discharging mechanism are arranged on the side wall of the furnace body, the cooling mechanism is arranged on part of the furnace body to separate the furnace chamber into a medium cooling section and a heating section, the atmosphere supply mechanism is arranged on the furnace body, and the waste gas discharge mechanism is arranged at the sealed isolation furnace door; by controlling the operation of the cooling mechanism, the heating mechanism and the atmosphere supply mechanism, the medium cooling and secondary heating processes or the carburizing diffusion process can be selectively performed on the batch of workpieces entering the furnace chamber through the inlet, so as to improve the production efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of workpiece heat treatment, in particular to a heat treatment push disc furnace capable of implementing carburizing diffusion, intermediate cooling and secondary heating processes. BACKGROUND

[0002] The intermediate cooling and secondary heating process in the carburizing diffusion process of workpiece heat treatment includes intermediate cooling of the workpiece after carburizing diffusion in a protective atmosphere, then secondary heating, and then quenching and other operations. The process has the advantages of reducing the residual austenite in the workpiece to refine the grains and improve the impact resistance of the workpiece, and a small amount of carbide is precipitated on the surface of the workpiece to further improve the wear resistance of the workpiece. At present, the process can only be implemented in a multi-purpose furnace. The implementation steps are as follows: first, the workpiece is subjected to carburizing diffusion operation in the rear chamber of the multi-purpose furnace, then the workpiece is transferred to the front chamber of the multi-purpose furnace, the explosive carburizing atmosphere is replaced with a protective atmosphere, and then the workpiece is pushed into the rear chamber for heating operation, and finally quenching and other operations are performed. The obvious disadvantage of using a multi-purpose furnace to implement the above process is that the process cycle of workpiece heat treatment is long, and continuous heat treatment of large quantities of workpieces cannot be achieved. This limits the promotion and use of the above process.

[0003] Therefore, how to develop a heat treatment furnace structure capable of implementing continuous intermediate cooling and secondary heating process operation on a large quantity of workpieces after carburizing diffusion to improve the production efficiency of workpiece heat treatment has become one of the important problems to be solved by the technical personnel in the field. SUMMARY

[0004] The technical problem to be solved by the present technical solution is how to implement continuous intermediate cooling and secondary heating process operation on a large quantity of workpieces after carburizing diffusion to improve the production efficiency of workpiece heat treatment.

[0005] Therefore, the present technical solution provides a heat treatment furnace structure for a large push disc controllable carburizing atmosphere production line to implement intermediate cooling and secondary heating process of a large quantity of workpieces. The heat treatment furnace structure is provided with an intermediate cooling section and heating elements in the push disc furnace body to implement intermediate cooling and secondary heating process on the workpieces in the push disc furnace body, and the carburizing diffusion process on the workpieces in the push disc furnace body can also be selectively implemented. Since the movement of the workpieces in the production line is in the form of disc pushing, it is impossible to absolutely separate the segments, and the carburizing atmosphere used in other segments will enter the intermediate cooling section during the transfer of the workpieces, and the carburizing atmosphere contains combustible and explosive atmosphere, and the cooling process of the intermediate cooling section is generally implemented at a temperature lower than 600 DEG C, which is far lower than the explosion safety temperature of 750 DEG C. If a small amount of oxygen enters the closed push disc furnace body, it will cause explosion danger. Therefore, how to solve the problem of oxygen content is one of the keys of the present technical solution.

[0006] To solve the above technical problems, the technical scheme provides a heat treatment pusher furnace capable of implementing carburizing diffusion, medium cooling and secondary heating processes, which is connected with a diffusion furnace discharge port of a pusher carburizing diffusion furnace and comprises a furnace body, a guide rail, a pusher moving mechanism, a gas circulation mechanism, a heating mechanism, a discharge mechanism, a cooling mechanism, an atmosphere supply mechanism and a waste gas discharge mechanism. An internal part of the furnace body forms a furnace chamber, and furnace side walls at both ends of the furnace body are respectively provided with an inlet port and a discharge port which are communicated with the furnace chamber. The inlet port is connected with the diffusion furnace discharge port in a position relationship and is provided with a sealed isolation furnace door. The discharge port is connected with subsequent process equipment and is provided with a sealed furnace door. The guide rail is arranged at the bottom of the furnace chamber and is adjacent to the inlet port and the discharge port at both ends. The pusher moving mechanism is arranged on a furnace end wall of the furnace body adjacent to the inlet port. The gas circulation mechanism and the heating mechanism are respectively arranged at the top and both sides of the furnace chamber. The discharge mechanism is arranged on a furnace side wall of the furnace body opposite to the discharge port. The cooling mechanism is arranged on a part of the furnace body adjacent to the inlet port to divide the furnace chamber into a medium cooling section adjacent to the inlet port and a heating section adjacent to the discharge port. The atmosphere supply mechanism is arranged on the furnace body and is communicated with the furnace chamber. The waste gas discharge mechanism is arranged at the sealed isolation furnace door. When the cooling mechanism and the heating mechanism in the heating section operate and the atmosphere supply mechanism selectively supplies a protective atmosphere, the heat treatment pusher furnace performs the medium cooling and secondary heating processes on workpieces entering the furnace chamber through the inlet port. When the cooling mechanism stops operating and the heating mechanisms in the heating section and the medium cooling section operate and the atmosphere supply mechanism selectively supplies a carburizing atmosphere, the heat treatment pusher furnace continues to perform the carburizing diffusion process on the workpieces entering the furnace chamber through the inlet port. Accordingly, the technical scheme adopts a pusher furnace structure to realize continuous heat treatment operation of a large number of workpieces in a pusher disc movement mode. By controlling the operation of the cooling mechanism, the heating mechanism and the atmosphere supply mechanism, the batch workpieces entering the furnace chamber through the inlet port after completing the carburizing diffusion process can selectively perform the medium cooling and secondary heating processes or continue to perform the carburizing diffusion process, thereby improving the heat treatment efficiency of the workpieces and increasing the diversity of the production line processes. In addition, by arranging the waste gas discharge mechanism at the sealed isolation furnace door, the carburizing atmosphere entering the medium cooling section from the pusher carburizing diffusion furnace can be effectively reduced, thereby reducing the risk of explosion of the heat treatment pusher furnace.

[0007] As another implementation of the technical solution, the cooling mechanism comprises a variable frequency speed-regulating air extractor, a cooling main pipe, a main electromagnetic butterfly valve and a plurality of air cooling pipes. The variable frequency speed-regulating air extractor is arranged outside the end of the furnace body. The cooling main pipe is arranged in a shape of П and fixedly arranged on the upper part of the furnace body above the middle cooling section. One end of the cooling main pipe is closed, and the other end is connected to the air extraction port of the variable frequency speed-regulating air extractor. The main electromagnetic butterfly valve is arranged on the cooling main pipe adjacent to the variable frequency speed-regulating air extractor. The plurality of air cooling pipes are divided into two rows. The air cooling pipes in each row are arranged at the same distance and vertically inserted into the furnace cavity from the top of the furnace body of the middle cooling section. The air cooling pipes in the two rows are arranged on the two sides of the guide rail. The part of the air cooling pipes exposed outside the top of the furnace body has an air suction port and a hot air exhaust port. The air cooling pipes are connected to the cooling main pipe through the hot air exhaust port. The variable frequency speed-regulating air extractor is started, and the main electromagnetic butterfly valve is opened to form a negative pressure in the cooling main pipe, so that the air cooling pipes suck air from the outside of the furnace body through the air suction port. The air absorbs heat in the furnace cavity through the air cooling pipes and is then discharged into the cooling main pipe through the hot air exhaust port. Finally, the air is discharged through the air exhaust port of the variable frequency speed-regulating air extractor. Since the temperature of the workpiece during the carburizing and diffusion process is usually maintained at 900℃ or above, the temperature of the workpiece after carburizing and diffusion is reduced to about 500-600℃ in the middle cooling section of the furnace cavity by the cooling mechanism. In the above high-temperature environment, liquid cooling medium cannot be used for cooling, otherwise the liquid cooling medium will be instantly heated to a vaporized state and lose its cooling effect. The technical solution uses air as a cooling medium. The air cooling pipes arranged in the middle cooling section of the furnace cavity make the low-temperature air sucked in absorb the heat energy in the furnace cavity through the side wall of the air cooling pipes. The high-temperature air after heat absorption is then discharged from the cooling mechanism through the cooling main pipe and the variable frequency speed-regulating air extractor. Thus, the technical solution is economical and environmentally friendly, and is continuous and stable. By adjusting the power of the variable frequency speed-regulating air extractor and the opening degree of the main electromagnetic butterfly valve, the cooling effect can be controlled and adjusted.

[0008] As another implementation of the technical solution, the air cooling pipe comprises an upper sleeve, a lower sleeve, a sealing flange and an inner pipe. The upper sleeve is arranged outside the top of the furnace body, the lower sleeve is inserted into the furnace cavity from the top of the furnace body, and the upper sleeve and the lower sleeve are sealingly connected by the sealing flange and fixedly arranged on the top of the furnace body. The inner pipe is inserted into the upper sleeve and the lower sleeve through the upper end of the upper sleeve, and there is an air suction gap between the lower end of the inner pipe and the lower end of the lower sleeve. The lower end of the lower sleeve is closed, the upper end of the upper sleeve is sealingly combined with the side wall of the inner pipe, and the upper end and the lower end of the inner pipe are both open and form a hot air outlet and a hot air inlet respectively. The hot air outlet is connected and communicated with the cooling main pipe through the flange, and the air inlet is arranged on the side wall of the upper sleeve. Accordingly, the inner pipe and the space between the upper sleeve and the lower sleeve and the inner pipe are driven by the frequency conversion speed regulation air extractor to form a negative pressure, so that the external air is sucked into the space between the upper sleeve, the lower sleeve and the inner pipe and flows uniformly from top to bottom, and at the same time absorbs the heat energy in the furnace cavity through the side wall of the lower sleeve. The high-temperature air after heat absorption enters the inner pipe through the hot air inlet and is discharged to the cooling main pipe through the hot air outlet. In this way, the external air is used to circularly cool the environment in the middle cooling section of the furnace cavity. In addition, when the frequency conversion speed regulation air extractor is started or stopped, a negative pressure or zero pressure state is formed in the air cooling pipe, and a positive pressure environment is always formed in the furnace cavity under the action of the atmosphere supply mechanism. Therefore, even if the lower sleeve is damaged due to corrosion caused by long-term use in a high-temperature environment, the atmosphere in the furnace cavity can only leak into the lower sleeve in the flow direction from positive pressure to negative pressure, so that the external air cannot enter the furnace cavity through the air cooling pipe, thereby ensuring the safety of the heat treatment push disc furnace.

[0009] As another implementation of the technical solution, the air inlet is provided with an air filter and a manual butterfly valve. In this way, the cleanliness of the suction air can be ensured, and the suction amount of air can be adjusted.

[0010] As another implementation of the technical solution, the upper side of the lower end of the lower sleeve is provided with a conical protruding part, and a plurality of supporting parts are fixedly arranged between the inner side of the lower sleeve and the outer side of the inner pipe. Accordingly, the conical protruding part is beneficial to reduce the turbulence phenomenon caused by the high-temperature air entering the hot air inlet, and the arrangement of the supporting part can stabilize the relative position of the lower sleeve and the inner pipe and strengthen the structural strength of the air cooling pipe.

[0011] As another implementation of the technical solution, the heat treatment push disc furnace further comprises a central control unit, and the cooling mechanism further comprises a thermocouple, a plurality of auxiliary electromagnetic butterfly valves and a plurality of air filters. The thermocouple is arranged on the cooling main pipe and located between the variable frequency speed regulating air extractor and the main electromagnetic butterfly valve. A plurality of air auxiliary suction inlets are formed on the cooling main pipe. The plurality of auxiliary electromagnetic butterfly valves and the plurality of air filters are respectively arranged in the plurality of air auxiliary suction inlets. The variable frequency speed regulating air extractor, the main electromagnetic butterfly valve, the thermocouple and the auxiliary electromagnetic butterfly valve are electrically connected with the central control unit. The central control unit is used for controlling the power of the variable frequency speed regulating air extractor according to the temperature sensed by the thermocouple, or controlling the opening degree of the main electromagnetic butterfly valve and / or the auxiliary electromagnetic butterfly valve. Since the variable frequency speed regulating air extractor extracts high-temperature air after absorbing heat in the air cooling pipe, long-term extraction of high-temperature air will affect the service life of the variable frequency speed regulating air extractor and increase the failure rate. Therefore, in order to reduce the temperature of the high-temperature air in the cooling main pipe, a plurality of air auxiliary suction inlets are formed on the cooling main pipe to introduce low-temperature air into the cooling main pipe to mix with the high-temperature air, thereby reducing the temperature of the air in the cooling main pipe. The real-time monitoring of the air temperature in the cooling main pipe by the thermocouple and the control of the opening degree of the auxiliary electromagnetic butterfly valve by the central control unit according to the temperature monitoring result can not only improve the accuracy of temperature control to prolong the service life of the variable frequency speed regulating air extractor, but also improve the automation degree of operation to reduce the labor cost.

[0012] As another implementation of the technical solution, the heating mechanism is composed of a plurality of heating elements electrically connected with the central control unit. The plurality of heating elements are divided into two columns. The plurality of heating elements in each column are vertically arranged in the furnace cavity at the same distance and located on both sides of the guide rail. The plurality of heating elements in the middle cooling section are arranged between the plurality of air cooling pipes. The central control unit is used for controlling the plurality of heating elements in the heating section to heat individually, or controlling the plurality of heating elements in the heating section and the middle cooling section to heat simultaneously. When the plurality of heating elements in the heating section heat individually, the plurality of heating elements in the middle cooling section do not work and the cooling mechanism works, and the atmosphere supply mechanism supplies the protective atmosphere, the heat treatment push disc furnace can implement the middle cooling and secondary heating process on the workpiece. When all the heating elements in the furnace cavity work, the cooling mechanism does not work, and the atmosphere supply mechanism supplies the carburizing atmosphere, the heat treatment push disc furnace can implement the carburizing diffusion process on the workpiece.

[0013] As another implementation of the technical solution, the atmosphere supply mechanism is composed of multiple supply pipelines provided with flow meters and electromagnetic valves and communicated with the furnace chamber, and the flow meters and electromagnetic valves are electrically connected with the central control unit, and the multiple supply pipelines can selectively supply the protective atmosphere or the carburizing atmosphere to the furnace chamber through the control of the central control unit. When the heat treatment pusher furnace implements the intermediate cooling and secondary heating process, the electromagnetic valves of the supply pipelines for supplying the carburizing atmosphere are closed, and the supply pipelines for supplying the protective atmosphere supply a large amount of protective gas (such as nitrogen) to maintain the positive pressure in the furnace chamber, thereby reducing the entry of the carburizing atmosphere and preventing the entry of the air outside the furnace body. When the heat treatment pusher furnace implements the carburizing and diffusion process, the electromagnetic valves of the supply pipelines for supplying the protective atmosphere are closed, and the supply pipelines for supplying the carburizing atmosphere supply carburizing gas to the furnace chamber.

[0014] As another implementation of the technical solution, the sealing and isolating furnace door is composed of a sealing middle door box, a lifting motor, a transmission shaft, a sealing bearing, a chain wheel, a chain, and two heat-resistant steel cast doors and connecting ear rings. The inlet and the outlet of the diffusion furnace are both provided with inclined guide bricks to form a furnace door closed cavity with a longitudinal section in the shape of an inverted isosceles trapezoid between the guide bricks of the inlet and the outlet of the diffusion furnace. The inlet and the outlet of the diffusion furnace are in register through being jointly covered by the heat-insulating furnace lining and the furnace shell, and the heat-insulating furnace lining and the furnace shell above the furnace door closed cavity are provided with a furnace door lifting space communicated with the outside. The sealing middle door box is combined with the upper part of the furnace door lifting space through the lower opening seal cover of the sealing middle door box, so that the inside of the sealing middle door box is communicated with the furnace door lifting space and the furnace door closed cavity. The lifting motor is installed on the outer side wall of the sealing middle door box and electrically connected with the central control unit. The transmission shaft is fixedly connected with the driving end of the lifting motor and horizontally and rotatably penetrates into the sealing middle door box through the sealing bearing. The chain wheel is fixedly sleeved on the transmission shaft, and the chain is engaged and wound around the chain wheel. The longitudinal sections of the two heat-resistant steel cast doors are both in the shape of an inverted right-angle trapezoid and movably inserted into the furnace door closed cavity with vertical surfaces in contact with each other. The upper parts of the two heat-resistant steel cast doors are both provided with connecting holes corresponding to the connecting ear rings. The lower end of the chain is fixedly combined with the connecting ear rings. The lifting motor is driven to rotate the transmission shaft to lift the two heat-resistant steel cast doors to the furnace door lifting space or insert the two heat-resistant steel cast doors into the furnace door closed cavity to close the two furnace openings through the control of the central control unit. The sealing and isolating furnace door can effectively reduce the cross talk of the atmospheres in the heat treatment pusher furnace and the pusher carburizing and diffusion furnace, and can also play a role in cooling and temperature isolation.

[0015] As another implementation of the present technical solution, the waste gas discharge mechanism is composed of a waste gas discharge pipe, a manual valve, a one-way valve and an ignition burner. One end of the waste gas discharge pipe is connected to the bottom of the furnace door closed cavity and communicates with the inside of the furnace door closed cavity. The manual valve is arranged on the waste gas discharge pipe. The other end of the waste gas discharge pipe is a waste gas discharge port and is provided with the one-way valve and the ignition burner. The one-way valve has an adjustable counterweight to set the waste gas discharge pressure, thereby assisting in maintaining the positive pressure in the furnace cavity. By arranging the waste gas discharge pipe at the bottom of the furnace door closed cavity region between the feeding port and the diffusion furnace discharge port, under the action of the positive pressure in the heat treatment push disc furnace, the part of the carburizing atmosphere flowing from the push disc carburizing diffusion furnace can be discharged as much as possible through the waste gas discharge pipe to the outside of the furnace door closed cavity region, so as to reduce the mixing of the carburizing atmosphere in the middle cooling section, thereby reducing the risk of explosion. In addition, the one-way valve arranged at the waste gas discharge port can also effectively prevent external air from entering the furnace cavity in the reverse direction through the waste gas discharge pipe, and the ignition burner can also ignite the combustible gas in the discharged waste gas to make the waste gas meet the environmental protection requirements. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A top view of a workpiece heat treatment production line equipped with the present application;

[0017] Figure 2 A top view of the middle cooling section region of the furnace body in the present application;

[0018] Figure 3 A side view schematic diagram of part of the furnace body in the present application.

[0019] Figure 4 A side view schematic diagram of the cooling mechanism in the present application;

[0020] Figure 5 A longitudinal sectional view schematic diagram of the air cooling pipe inserted into the top of the furnace body in the present application;

[0021] Figure 6 A structural schematic diagram of the air cooling pipe in the present application;

[0022] Figure 7 A schematic diagram of the multi-path gas supply pipeline of the atmosphere gas supply mechanism in the present application;

[0023] Figure 8 A side view sectional view of the sealing isolation furnace door in the present application;

[0024] Figure 9 A structural schematic diagram of the waste gas discharge mechanism in the present application;

[0025] Figure 10 A side view sectional view of the explosion-proof pressure relief port in the present application.

[0026] Explanation of symbols in the drawings:

[0027] A heat treatment pusher furnace; B heating section; C diffusion section; C1 diffusion furnace discharge port; D quenching tank; 1 furnace body; 11 furnace cavity; 111 middle cooling section; 112 heating section; 12 feeding port; 13 discharge port; 14 through hole; 15 guide rail; 16 pusher moving mechanism; 17 discharge mechanism; 18 sealing furnace door; 2 gas circulation mechanism; 21 high-temperature circulating fan; 3 heating mechanism; 31 heating element; 4 cooling mechanism; 41 variable frequency speed regulation air extractor; 42 cooling main pipe; 43 main electromagnetic butterfly valve; 431 air auxiliary suction port; 432 auxiliary electromagnetic butterfly valve; 433 air filter; 44 air cooling pipe; 441 upper sleeve; 4411 air suction port; 4412 air filter; 4413 manual butterfly valve; 442 lower sleeve; 4421 conical protruding part; 443 sealing flange; 444 inner pipe; 4441 hot air discharge port; 4442 hot air suction port; 445 supporting part; 45 thermocouple; 5 atmosphere gas supply mechanism; 51 gas supply pipeline; 511 flow meter; 512 electromagnetic valve; a protective atmosphere; b carburizing atmosphere; 6 waste gas discharge mechanism; 61 waste gas discharge pipe; 62 manual valve; 63 one-way valve; 64 ignition burner; 7 sealing isolation furnace door; 71 sealing middle door box; 72 lifting motor; 73 transmission shaft; 74 chain wheel; 75 chain; 76 heat-resistant steel cast door; 77 connecting ear ring; 78 guide brick; 79 furnace door lifting space; 8 explosion-proof pressure relief port; 81 heat preservation sleeve; 82 annular support; 83 protection plate; 84 explosion-proof membrane; 91 maintenance door; 92 carbon black burning device. DETAILED DESCRIPTION

[0028] The detailed description and technical content of the present application are described below in conjunction with the drawings, however, the accompanying drawings are provided for reference and illustration only, and are not intended to limit the present application.

[0029] In the context of the present specification, any two or more embodiments of the present application can be combined arbitrarily, and the technical solutions formed thereby are part of the original disclosure of the present specification and also fall within the protection scope of the present application.

[0030] As Figure 1As shown, it is a top view of a workpiece heat treatment production line equipped with the heat treatment pusher furnace of the present application which can implement carburizing diffusion, intercooling and secondary heating process. In the figure, the heat treatment pusher furnace A of the present application which can implement carburizing diffusion, intercooling and secondary heating process (hereinafter referred to as heat treatment pusher furnace A) is connected between the pusher carburizing diffusion furnace and the subsequent process equipment, wherein the pusher carburizing diffusion furnace is the existing and widely used furnace structure, which is usually composed of a heating section B and a diffusion section C, and the subsequent process equipment can be a quenching tank D, or a discharge air exchange chamber and other equipment, and the present application does not limit the type of the subsequent process equipment. More specifically, in the figure, the heat treatment pusher furnace A of the present application is connected between the diffusion section C of the pusher carburizing diffusion furnace and the quenching tank D, and the connection mode is sealed welding, and all external connecting parts on the above device are connected using a sealed structure to ensure that the internal operating environment of the heat treatment pusher furnace A is not in contact with the outside air.

[0031] In combination Figure 2 and 3As shown, the heat treatment pusher furnace A of the present application comprises a furnace body 1, a guide rail 15, a pusher moving mechanism 16, a gas circulation mechanism 2, a heating mechanism 3, a discharge mechanism 17, a cooling mechanism 4, an atmosphere supply mechanism 5 and a waste gas discharge mechanism 6. The furnace body 1 is composed of a heat preservation furnace lining (not shown in the figure) and a furnace shell (not shown in the figure) wrapped outside the heat preservation furnace lining, a furnace cavity 11 is formed inside the furnace body 1, and a material inlet 12 and a material outlet 13 are respectively arranged on the furnace side walls at both ends of the furnace body 1 and communicate with the furnace cavity 11, the material inlet 12 is connected with the diffusion furnace material outlet C1 of the diffusion section C in a position-locked manner and is provided with a sealing isolation furnace door 7, and the material outlet 13 is connected with subsequent process equipment (such as a quenching tank D) and is provided with a sealing furnace door 18. The guide rail 15 can be made of silicon carbide which is wear-resistant and high-temperature-resistant, and is arranged at the bottom of the furnace cavity 11 and adjacent to the material inlet 12 and the material outlet 13 at both ends of the guide rail 15. The pusher moving mechanism 16 can be an electric push rod device and is arranged on the furnace end wall of the furnace body 1 adjacent to the material inlet 12. The electric push rod device is a workpiece pushing device commonly used in various pusher furnaces in the prior art, which is operated by extending or retracting the pushing rod into the furnace cavity to move the workpiece or tray in a tray-pushing-tray manner on the guide rail. The gas circulation mechanism 2 and the heating mechanism 3 are respectively arranged at the top and both sides of the furnace cavity 11. The gas circulation mechanism 2 can be composed of a plurality of high-temperature circulating fans 21, which can make the atmosphere and temperature distribution in the furnace cavity 11 uniform through the operation of the high-temperature circulating fans 21. The discharge mechanism 17 can use a side pushing chain device, which is a discharge device that saves operation space in the prior art. The side pushing chain device is arranged on the furnace side wall of the furnace body 1 opposite to the material outlet 13 and drives the push head through the driving chain to push the workpiece or tray on the guide rail 15 to perform the discharge operation. The cooling mechanism 4 is arranged on the part of the furnace body 1 adjacent to the material inlet 12, so as to divide the furnace cavity 11 into a cooling section 111 adjacent to the material inlet 12 and a heating section 112 adjacent to the material outlet 13. A retaining wall (not shown in the figure) with a through opening for the workpiece or tray to pass through is further formed on the inner side wall of the furnace cavity 11 between the cooling section 111 and the heating section 112, so as to isolate the temperature of the cooling section and the heating section. The atmosphere supply mechanism 5 is arranged on the furnace body 1 and communicates with the furnace cavity 11. The waste gas discharge mechanism 6 is arranged at the sealing isolation furnace door 7. When the cooling mechanism 4 and the part of the heating mechanism 3 located in the heating section 112 are started to operate, and the atmosphere supply mechanism 5 selectively supplies a protective atmosphere, the heat treatment pusher furnace A performs the cooling and secondary heating processes on the workpiece entering the furnace cavity 11 through the material inlet 12 during the operation of the workpiece heat treatment production line. When the cooling mechanism 4 stops to operate, the heating mechanism 3 located in the heating section 112 and the cooling section 111 is started to operate, and the atmosphere supply mechanism 5 selectively supplies a carburizing atmosphere, the heat treatment pusher furnace A continues to perform the carburizing and diffusion processes on the workpiece entering the furnace cavity 11 through the material inlet 12.

[0032] Specifically, in combination with Figure 4As shown, the cooling mechanism 4 in the present application comprises a variable frequency speed-regulated air extractor 41, a cooling main pipe 42, a main electromagnetic butterfly valve 43 and a plurality of air cooling pipes 44. The variable frequency speed-regulated air extractor 41 is arranged outside the end portion of the furnace body 1. The cooling main pipe 42 is fixedly arranged on the upper portion of the furnace body 1 above the middle cooling section 111 in a shape of п, and one end of the cooling main pipe 42 is closed, and the other end is connected to the air extraction port of the variable frequency speed-regulated air extractor 41. The main electromagnetic butterfly valve 43 is arranged on the cooling main pipe 42 adjacent to the variable frequency speed-regulated air extractor 41. The plurality of air cooling pipes 44 are arranged in two rows, and the air cooling pipes 44 in each row are vertically inserted into the furnace cavity 11 from the top of the furnace body 1 of the middle cooling section 111 at the same distance, and the air cooling pipes 44 in the two rows are arranged on the two sides of the guide rail 15, and the portions of the air cooling pipes 44 exposed outside the top of the furnace body 1 have air suction ports 4411 and hot air exhaust ports 4441, and the air cooling pipes 44 are connected to the cooling main pipe 42 through the hot air exhaust ports 4441. When the cooling mechanism 4 is running, the variable frequency speed-regulated air extractor 41 is started and the main electromagnetic butterfly valve 43 is opened to form a negative pressure in the cooling main pipe 42, so that the air cooling pipes 44 suck air from the outside of the furnace body 1 through the air suction ports 4411, the air absorbs heat in the furnace cavity 11 through the side walls of the air cooling pipes 44, and then is discharged into the cooling main pipe 42 through the hot air exhaust ports 4441, and finally is discharged through the air extraction port of the variable frequency speed-regulated air extractor 41. Since the temperature of the workpiece during the carburizing and diffusion process is usually maintained above 900℃, and the temperature of the workpiece after carburizing and diffusion is reduced to about 500-600℃ by the cooling mechanism 4 in the middle cooling section 111 of the furnace cavity 11, it is impossible to use liquid cooling medium to cool in the above high temperature environment, otherwise the liquid cooling medium will be instantaneously heated to vaporization state and lose the cooling effect. The present application uses air as the cooling medium, and the low-temperature air sucked into the air cooling pipes 44 arranged in the furnace cavity 11 of the middle cooling section 111 absorbs the heat energy in the furnace cavity through the side walls of the air cooling pipes 44, and then the high-temperature air after heat absorption is discharged from the cooling mechanism 4 through the cooling main pipe 42 and the variable frequency speed-regulated air extractor 41, thereby being economical and environmentally friendly, stable and continuous, and the cooling effect can be controlled and adjusted by adjusting the power of the variable frequency speed-regulated air extractor 41 and the opening degree of the main electromagnetic butterfly valve 43.

[0033] Further, in combination with Figure 5 and 6As shown, the air cooling pipe 44 comprises an upper sleeve 441, a lower sleeve 442, a sealing flange 443 and an inner pipe 444. The upper sleeve 441 is arranged outside the top of the furnace body 1, the lower sleeve 442 is inserted into the furnace cavity 11 from the top of the furnace body 1, and the upper sleeve 441 and the lower sleeve 442 are sealingly connected and fixedly arranged on the top of the furnace body 1 through the sealing flange 443. The inner pipe 444 is inserted into the upper and lower sleeves 441, 442 through the upper end of the upper sleeve 441, and there is a suction gap between the lower end of the inner pipe 444 and the lower end of the lower sleeve 442. The lower end of the lower sleeve 442 is closed, the upper end of the upper sleeve 441 and the side wall of the inner pipe 444 can be sealingly combined by welding, and the upper and lower ends of the inner pipe 444 are both open and form a hot air outlet 4441 and a hot air inlet 4442, respectively. The hot air outlet 4441 is connected and communicated with the cooling main pipe 42 through a flange, and the air inlet 4411 is arranged on the side wall of the upper sleeve 441. The variable frequency speed regulation air extractor 41 is driven to form a negative pressure in the inner pipe 444 and between the upper and lower sleeves 441, 442 and the inner pipe 444, so that external air is sucked into the space between the upper and lower sleeves 441, 442 and the inner pipe 444 through the air inlet 4411 and flows uniformly from top to bottom while absorbing heat energy in the furnace cavity 11 through the side wall of the lower sleeve 442. The high-temperature air after heat absorption enters the inner pipe 444 through the hot air inlet 4442 and is discharged into the cooling main pipe 42 through the hot air outlet 4441, thereby realizing the circulation cooling of the environment in the middle cooling section 111 of the furnace cavity 11 by external air. In addition, since the variable frequency speed regulation air extractor 41 forms a negative pressure or zero pressure state in the air cooling pipe 44 when it is started or stopped, and the atmosphere in the furnace cavity 11 always forms a positive pressure environment under the action of the atmosphere supply mechanism 5, even if the lower sleeve 442 is damaged due to corrosion after long-term use at high temperature, the atmosphere in the furnace cavity 11 can only leak into the lower sleeve 442 in the flow direction from positive pressure to negative pressure, thereby avoiding the entry of external air into the furnace cavity 11 through the air cooling pipe 44, and ensuring the safety of the operation of the heat treatment push disc furnace A. In addition, the air inlet 4411 can be provided with an air filter 4412 and a manual butterfly valve 4413 to ensure the cleanliness of the suction air and facilitate the adjustment of the suction amount of air. The upper side of the lower end of the lower sleeve 442 can be provided with a conical protrusion 4421, and the inner side of the lower sleeve 442 and the outer side of the inner pipe 444 can be fixedly provided with a plurality of support portions 445. The conical protrusion 4421 is helpful to reduce the turbulence phenomenon of high-temperature air entering the hot air inlet 4442, and the arrangement of the support portions 445 can stabilize the relative position of the lower sleeve 442 and the inner pipe 444 and strengthen the structural strength of the air cooling pipe 44.

[0034] Further, in order to improve the degree of automation, the heat treatment pusher furnace A can further comprise a central control unit (not shown in the figure), and the cooling mechanism 4 can further comprise a thermocouple 45, a plurality of auxiliary electromagnetic butterfly valves 432 and a plurality of air filters 433. The thermocouple 45 is arranged on the cooling main pipe 42 and located between the variable frequency speed regulation air extractor 41 and the main electromagnetic butterfly valve 43. The cooling main pipe 42 is provided with a plurality of air auxiliary suction inlets 431, and the plurality of auxiliary electromagnetic butterfly valves 432 and the plurality of air filters 433 are arranged corresponding to the plurality of air auxiliary suction inlets 431. The variable frequency speed regulation air extractor 41, the main electromagnetic butterfly valve 43, the thermocouple 45 and the auxiliary electromagnetic butterfly valve 432 are electrically connected with the central control unit. The power of the variable frequency speed regulation air extractor 41 or the opening degree of the main electromagnetic butterfly valve 43 and / or the auxiliary electromagnetic butterfly valve 432 can be adjusted according to the temperature sensed by the thermocouple 45 through the control of the central control unit. Since the variable frequency speed regulation air extractor 41 extracts high-temperature air after absorbing heat energy in the air cooling pipe 44, long-term extraction of high-temperature air will affect the service life of the variable frequency speed regulation air extractor 41 and increase the failure rate. Therefore, in order to reduce the temperature of the high-temperature air in the cooling main pipe 42, a plurality of air auxiliary suction inlets 431 are arranged on the cooling main pipe 42 to introduce low-temperature air into the cooling main pipe 42 to mix with the high-temperature air, thereby reducing the temperature of the air in the cooling main pipe 42. The opening degree of the auxiliary electromagnetic butterfly valve 432 is controlled according to the temperature monitoring result by the central control unit through the real-time monitoring of the air temperature in the cooling main pipe 42 by the thermocouple 45. This not only improves the accuracy of temperature regulation to prolong the service life of the variable frequency speed regulation air extractor 41, but also improves the degree of automation to reduce labor costs.

[0035] In the present application, the central control unit can be composed of a programmable logic control circuit (PLC), a central control circuit, a central control computer, an upper server, etc. Since the application of the central control unit to control the running state of each functional mechanism or component according to the input instruction or detected data is a very common control technology in the field of automation control, it is a prior art. Therefore, the application of the central control unit to control the running process of the above-mentioned functional mechanism or component will not be described in detail.

[0036] Further, the heating mechanism 3 can be composed of a plurality of heating elements 31 electrically connected to the central control unit. The heating elements 31 can be electrically heated radiant tubes. The plurality of heating elements 31 can be divided into two columns, and each column of the plurality of heating elements 31 is vertically arranged in the furnace cavity 11 at the same interval and located at the two sides of the guide rail 15, respectively. The plurality of heating elements 31 in the intermediate cooling section 111 are arranged between the plurality of air cooling pipes 44, respectively. The central control unit is used to control the plurality of heating elements 31 in the heating section 112 to be heated individually or the plurality of heating elements 31 in the heating section 112 and the intermediate cooling section 111 to be heated simultaneously. When the plurality of heating elements 31 in the heating section 112 are heated individually, the plurality of heating elements 31 in the intermediate cooling section 111 are not operated, the cooling mechanism 4 is operated, and the atmosphere supply mechanism 5 supplies the protective atmosphere, the heat treatment pusher furnace A can perform the intermediate cooling and secondary heating process on the workpiece. When all the heating elements 31 in the furnace cavity 11 are operated, the cooling mechanism 4 is stopped, and the atmosphere supply mechanism 5 supplies the carburizing atmosphere, the heat treatment pusher furnace A can perform the carburizing diffusion process on the workpiece.

[0037] Further, as shown in Figure 7 The atmosphere supply mechanism 5 can be composed of a plurality of gas supply pipelines 51 provided with flow meters 511 and electromagnetic valves 512 and communicated with the furnace cavity 11, and the flow meters 511 and the electromagnetic valves 512 are electrically connected to the central control unit, respectively. The central control unit is used to control the plurality of gas supply pipelines 51 to selectively supply the protective atmosphere a or the carburizing atmosphere b into the furnace cavity 11. When the heat treatment pusher furnace A performs the intermediate cooling and secondary heating process, the electromagnetic valves 512 of the gas supply pipelines 51 for supplying the carburizing atmosphere b are closed, and the gas supply pipelines 51 for supplying the protective atmosphere a supply the protective atmosphere a (such as nitrogen) at a large flow rate to maintain the positive pressure in the furnace cavity 11, thereby reducing and diluting the carburizing atmosphere entering from the diffusion section C and preventing the entry of air outside the furnace body. When the heat treatment pusher furnace A performs the carburizing diffusion process, the electromagnetic valves 512 of the gas supply pipelines 51 for supplying the protective atmosphere a are closed, and the gas supply pipelines 51 for supplying the carburizing atmosphere b supply the carburizing atmosphere b into the furnace cavity 11.

[0038] Further, as shown in Figure 8As shown, the sealing and isolating furnace door 7 can be composed of a sealing middle door box 71, a lifting motor 72, a transmission shaft 73, a sealing bearing (not shown), a chain wheel 74, a chain 75, two heat-resistant steel cast doors 76 and connecting ear rings 77. Among them, the inlet 12 and the diffusion furnace outlet C1 are both paved with inclined guide bricks 78, and a furnace door closed cavity with a longitudinal section in the shape of an inverted isosceles trapezoid is formed between the guide bricks 78 of the inlet 12 and the diffusion furnace outlet C1. The inlet 12 and the diffusion furnace outlet C1 are aligned and connected by being covered by the heat-insulating lining and the furnace shell, and the heat-insulating lining and the furnace shell above the furnace door closed cavity are provided with a furnace door lifting space 79 communicating with the outside. The sealing middle door box 71 is combined with the furnace shell above the furnace door lifting space 79 by sealing the lower opening of the sealing middle door box 71, so that the inside of the sealing middle door box 71 communicates with the furnace door lifting space 79 and the furnace door closed cavity. The lifting motor 72 is installed on the outer wall of the sealing middle door box 71 and is electrically connected with the central control unit. The transmission shaft 73 is fixedly connected with the driving end of the lifting motor 72 and horizontally and rotatably penetrates the sealing middle door box 71 through the sealing bearing. The chain wheel 74 is fixedly sleeved on the transmission shaft 73, and the chain 75 is engaged and wound around the chain wheel 74. The longitudinal sections of the two heat-resistant steel cast doors 76 are both in the shape of an inverted right-angle trapezoid and are movably inserted into the furnace door closed cavity with vertical surfaces contacting each other. The upper parts of the two heat-resistant steel cast doors 76 are both provided with connecting holes (not shown) and penetratingly provided with connecting ear rings 77, and the lower end of the chain 75 is fixedly combined with the connecting ear rings 77. Through the control of the central control unit, the lifting motor 72 drives the transmission shaft 73 to rotate to lift the two heat-resistant steel cast doors 76 to the furnace door lifting space 79, or the two heat-resistant steel cast doors 76 are inserted into the furnace door closed cavity to close the two side furnace openings under the guidance of the guide bricks 78 by relying on their own weight. Through the setting of the sealing and isolating furnace door 7, the cross talk of the atmosphere in the heat treatment push disc furnace A and the push disc carburizing diffusion furnace can be effectively reduced, and the cooling and temperature isolation effect can be achieved.

[0039] Furthermore, in combination with Figure 9As shown, the exhaust emission mechanism 6 can be composed of an exhaust emission pipe 61, a manual valve 62, a one-way valve 63 and an ignition burner 64. Among them, one end of the exhaust emission pipe 61 is connected to the bottom of the furnace door closed cavity and communicates with the inside of the furnace door closed cavity, the manual valve 62 is arranged on the exhaust emission pipe 61, the other end of the exhaust emission pipe 61 is an exhaust emission port and is provided with a one-way valve 63 and an ignition burner 64, and the one-way valve 63 has adjustable counterweight to be able to set the exhaust emission pressure, thereby assisting to maintain the positive pressure in the furnace cavity 11. By arranging the exhaust emission pipe 61 at the bottom of the furnace door closed cavity region between the feeding port 12 and the diffusion furnace discharge port C1, under the action of the positive pressure in the heat treatment pusher furnace A, the part of the carburizing atmosphere flowing from the pusher carburizing diffusion furnace can be discharged as much as possible through the exhaust emission pipe 61 to the outside of the furnace door closed cavity region on the sealing isolation furnace door 7, so as to reduce the mixing of the carburizing atmosphere in the middle cooling section 111, thereby reducing the risk of explosion. In addition, the one-way valve 63 arranged at the exhaust emission port can also effectively prevent external air from entering the furnace cavity 11 in the reverse direction through the exhaust emission pipe 61 and can assist to maintain the positive pressure in the furnace cavity 11, and the ignition burner 64 can also ignite the combustible gas in the exhaust gas to make the exhaust gas meet the environmental protection requirements.

[0040] In addition, in order to cope with the occurrence of extreme cases, in combination with Figure 10 As shown, the top of the heat treatment pusher furnace A can also be provided with a plurality of explosion-proof pressure relief ports 8. Each explosion-proof pressure relief port 8 can be composed of a heat preservation sleeve 81, an annular support 82, a protective plate 83 and an explosion-proof membrane 84. Correspondingly, a plurality of through holes 14 communicating with the furnace cavity 11 are formed in the top of the furnace body 1, the heat preservation sleeve 81 composed of heat-resistant steel plate net and middle built-in heat preservation fiber cotton is floatingly placed in the through hole 14, the annular support 82 is sealingly combined at the through hole 14 by welding or the like, and the upper part of the annular support 82 and the lower part of the protective plate 83 both have connecting flanges, the annular support 82 and the protective plate 83 are fixed by butt joint of the connecting flanges, and the explosion-proof membrane 84 is clamped at the flange hole of the connecting flanges. When the atmosphere in the furnace cavity 11 explodes and the pressure rises sharply, the explosion-proof membrane 84 will burst according to the set pressure to perform emergency pressure relief for the furnace cavity 11, and the protective plate 83 can prevent objects in the furnace cavity 11 from splashing out.

[0041] In addition to the above settings, in combination with Figure 3As shown, the heat treatment push disc furnace A of the present application can also be provided with a maintenance door 91 on the furnace body 1 for maintenance personnel to access the furnace maintenance equipment, and an observation window (not marked in the figure) for viewing the situation inside the furnace cavity. A workpiece limiter (not shown in the figure) for sensing the workpiece or tray discharge position can also be installed on the furnace wall near the discharge port 13, and an oxygen probe (not shown in the figure) for sensing the carburizing atmosphere can also be provided in the furnace cavity 11, and the drive and monitoring devices such as the push disc moving mechanism 16, the discharge mechanism 17, the workpiece limiter and the oxygen probe are all electrically connected with the central control unit, so as to further improve the degree of automation of the heat treatment push disc furnace and ensure the quality of process operation, thereby ensuring the quality of workpiece heat treatment. In addition, the heat treatment push disc furnace can also be provided with a carbon black burning device 92 composed of a gas pump, a solenoid valve and other components, which can periodically burn and eliminate the carbon black generated in the furnace cavity due to long-term use.

[0042] In summary, the heat treatment push disc furnace of the present application adopts a push disc furnace structure to realize continuous heat treatment of a large number of workpieces in a push disc manner, and by controlling the operation of the cooling mechanism, the heating mechanism and the atmosphere supply mechanism, the batch workpieces after completing the carburizing diffusion process can be selectively executed with intercooling and secondary heating process, or continue to execute the carburizing diffusion process, thereby not only improving the heat treatment efficiency of the workpieces, but also increasing the diversity of the production line process. In addition, by providing the exhaust gas discharge mechanism at the sealed isolation furnace door, the carburizing atmosphere entering the intercooling section from the push disc carburizing diffusion furnace can be effectively reduced, thereby reducing the risk of explosion of the heat treatment push disc furnace.

[0043] The above is only a preferred embodiment of the present application, and is not intended to limit the patent scope of the present application, and other equivalent changes made by applying the patent concept of the present application should all belong to the patent protection scope of the present application.

Claims

1. A heat treatment pusher furnace capable of performing carburizing diffusion, intercooling, and secondary heating processes, connected to the discharge port of a pusher carburizing diffusion furnace, the heat treatment pusher furnace comprising: The furnace comprises a furnace body, guide rails, a pusher plate moving mechanism, a gas circulation mechanism, a heating mechanism, and a discharge mechanism. The furnace body forms a furnace cavity, and the side walls at both ends of the furnace body have inlet and outlet ports communicating with the furnace cavity, respectively. The inlet port is aligned with the outlet port of the diffusion furnace and is equipped with a sealed furnace door. The outlet port is connected to subsequent process equipment and is also equipped with a sealed furnace door. The guide rail is located at the bottom of the furnace cavity, with its two ends adjacent to the inlet and outlet ports, respectively. The pusher plate moving mechanism is mounted on the furnace end wall of the furnace body adjacent to the inlet port. The gas circulation mechanism and heating mechanism are respectively mounted on the top and sides of the furnace cavity. The discharge mechanism is mounted on the side wall of the furnace body opposite the outlet port. Its characteristic is that... The furnace also includes: a cooling mechanism, an atmosphere supply mechanism, and an exhaust gas emission mechanism. The cooling mechanism is installed on a portion of the furnace body adjacent to the feed inlet to divide the furnace cavity into an intermediate cooling section adjacent to the feed inlet and a heating section adjacent to the discharge inlet. The atmosphere supply mechanism is installed on the furnace body and communicates with the furnace cavity. The exhaust gas emission mechanism is installed at the sealed and isolated furnace door. When the cooling mechanism and the portion of the heating mechanism located in the heating section are operating, and the atmosphere supply mechanism selectively supplies a protective atmosphere, the heat treatment pusher furnace performs intermediate cooling and secondary heating processes on the workpieces entering the furnace cavity through the feed inlet. When the cooling mechanism stops operating, but the heating mechanisms located in the heating section and the intermediate cooling section are operating... Furthermore, when the atmosphere supply mechanism selectively supplies a carburizing atmosphere, the heat treatment pusher furnace continues to perform the carburizing diffusion process on the workpieces entering the furnace cavity through the feed port; the cooling mechanism includes: a variable frequency speed-regulating exhaust fan, a cooling main pipe, a main electromagnetic butterfly valve, and multiple air cooling pipes. The variable frequency speed-regulating exhaust fan is installed on the outer side of the furnace body end. The cooling main pipe is shaped like a п and fixedly mounted on the upper part of the furnace body, located above the intermediate cooling section. One end of the cooling main pipe is closed, and the other end is connected to the exhaust port of the variable frequency speed-regulating exhaust fan. The main electromagnetic butterfly valve is located on the cooling main pipe and adjacent to the variable frequency speed-regulating exhaust fan. The multiple air cooling pipes are divided into two rows, and the multiple air cooling pipes in each row are spaced at the same distance and vertically... The air cooling pipes are inserted vertically into the furnace cavity from the top of the intermediate cooling section of the furnace body. The multiple air cooling pipes in the two rows are located on both sides of the guide rail. The portion of the air cooling pipes exposed on the outer side of the top of the furnace body has an air intake and a hot air exhaust. The multiple air cooling pipes are all connected to the cooling main pipe through the hot air exhaust. By starting the variable frequency speed control exhaust fan and opening the main electromagnetic butterfly valve, a negative pressure is formed in the cooling main pipe, so that the air cooling pipes draw air from the outside of the furnace body through the air intake. The air absorbs heat from the furnace cavity through the air cooling pipes and is then discharged into the cooling main pipe through the hot air exhaust, and finally discharged through the exhaust port of the variable frequency speed control exhaust fan.

2. The heat treatment pusher furnace according to claim 1, characterized in that, The air cooling pipe includes an upper sleeve, a lower sleeve, a sealing flange, and an inner tube. The upper sleeve is located on the outer side of the top of the furnace body. The lower sleeve is inserted into the furnace cavity from the top of the furnace body. The upper and lower sleeves are sealed and fixedly installed on the top of the furnace body through the sealing flange. The inner tube passes through the upper end of the upper sleeve into the upper and lower sleeves. There is an air intake gap between the lower end of the inner tube and the lower end of the lower sleeve. The lower end of the lower sleeve is closed. The upper end of the upper sleeve is sealed to the side wall of the inner tube. The upper and lower ends of the inner tube are open and form a hot air outlet and a hot air inlet, respectively. The hot air outlet is connected to the cooling main pipe through the flange. The air inlet is located on the side wall of the upper sleeve.

3. The heat treatment pusher furnace according to claim 2, characterized in that, The air intake is equipped with an air filter and a manual butterfly valve.

4. The heat treatment pusher furnace according to claim 2, characterized in that, The lower end of the lower sleeve has a tapered protrusion on its upper side, and several support parts are fixedly provided between the inner side of the lower sleeve and the outer side of the inner tube.

5. The heat treatment pusher furnace according to claim 1, characterized in that, Also includes: The central control unit, and the cooling mechanism further includes: a thermocouple, several auxiliary electromagnetic butterfly valves, and several air filters. The thermocouple is disposed on the cooling main pipe and located between the variable frequency speed control exhaust fan and the main electromagnetic butterfly valve. Several auxiliary air intake ports are opened on the cooling main pipe. The several auxiliary electromagnetic butterfly valves and several air filters are respectively disposed on the several auxiliary air intake ports. The variable frequency speed control exhaust fan, the main electromagnetic butterfly valve, the thermocouple, and the auxiliary electromagnetic butterfly valves are electrically connected to the central control unit. The central control unit controls the adjustment of the power of the variable frequency speed control exhaust fan according to the temperature sensed by the thermocouple, or adjusts the opening degree of the main electromagnetic butterfly valve and / or the auxiliary electromagnetic butterfly valve.

6. The heat treatment pusher furnace according to claim 5, characterized in that, The heating mechanism consists of multiple heating elements electrically connected to the central control unit. The multiple heating elements are divided into two rows, and the multiple heating elements in each row are spaced at the same distance and vertically arranged in the furnace cavity and located on both sides of the guide rail. In the intermediate cooling section, several heating elements are respectively arranged between the multiple air cooling pipes. The central control unit controls the heating elements located in the heating section to heat individually, or to heat the multiple heating elements in the heating section and the intermediate cooling section simultaneously.

7. The heat treatment pusher furnace according to claim 5, characterized in that, The atmosphere supply mechanism consists of multiple gas supply pipelines equipped with flow meters and solenoid valves and connected to the furnace cavity. The flow meters and solenoid valves are electrically connected to the central control unit. The central control unit controls the multiple gas supply pipelines to selectively supply protective atmosphere or carburizing atmosphere to the furnace cavity.

8. The heat treatment pusher furnace according to claim 5, characterized in that, The sealed isolation furnace door consists of a sealed inner door box, a lifting motor, a drive shaft, a sealed bearing, a sprocket, a chain, two heat-resistant steel cast doors, and connecting lugs. Both the inlet and the outlet of the diffusion furnace are constructed with inclined guide bricks, forming a furnace door sealing cavity with a longitudinal cross-section of an inverted isosceles trapezoid between the guide bricks. The inlet and outlet of the diffusion furnace are aligned and connected by being jointly covered by the insulating furnace lining and the furnace shell. A furnace door lifting space, communicating with the outside, is provided in the insulating furnace lining and furnace shell above the furnace door sealing cavity. The sealed inner door box, with its lower opening sealed cover, is attached above the furnace door lifting space, allowing communication between the interior of the sealed inner door box and the furnace door lifting space and the furnace door sealing cavity. The lifting motor is installed on the outer wall of the sealed inner door box and... The central control unit is electrically connected. The drive shaft is fixedly connected to the drive end of the lifting motor and is horizontally and rotatably inserted into the sealed middle door box through the sealed bearing. The sprocket is fixedly sleeved on the drive shaft, and the chain is meshed and wound around the sprocket. The longitudinal sections of the two heat-resistant steel casting doors are both inverted right-angled trapezoids and are vertically contacting each other, and are movably inserted into the furnace door sealing cavity. The upper part of the two heat-resistant steel casting doors is provided with corresponding connecting holes and the connecting lugs are inserted through them. The lower end of the chain is fixedly connected to the connecting lugs. The central control unit controls the lifting motor to drive the drive shaft to rotate, thereby lifting the two heat-resistant steel casting doors into the furnace door lifting space, or inserting the two heat-resistant steel casting doors into the furnace door sealing cavity.

9. The heat treatment pusher furnace according to claim 8, characterized in that, The exhaust gas emission mechanism consists of an exhaust gas emission pipe, a manual valve, a check valve, and an ignition burner. One end of the exhaust gas emission pipe is connected to the bottom of the furnace door sealing cavity and communicates with the inside of the furnace door sealing cavity. The manual valve is installed on the exhaust gas emission pipe. The other end of the exhaust gas emission pipe is an exhaust gas emission port and is equipped with the check valve and the ignition burner.

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