Vacuum heat treatment equipment

Abstract

The vacuum heat treatment equipment comprises a vacuum furnace and a heat preservation cover, a vacuum cavity is formed in the vacuum furnace, a muffle cover is fixedly arranged in the vacuum cavity and extends in the axial direction of the vacuum cavity, and an annular cavity is formed between the muffle cover and the vacuum cavity; the axial fan is arranged at the air inlet of the vacuum cavity, the two ends of the muffle cover are communicated with the air inlet and the annular cavity respectively, a circulating air path is formed between the muffle cover and the vacuum furnace, the convection heat exchange efficiency is enhanced, and the temperature uniformity of the vacuum furnace is improved. The heat preservation cover is arranged on the periphery of the vacuum furnace in a covering mode, the heat treatment requirement can be met only through single-time vacuumizing, and the oxygen content and the heat treatment process are stable. A plurality of heaters are fixedly arranged on the inner side wall of the heat preservation cover and evenly distributed in the circumferential direction of the vacuum furnace. After all the heaters heat the outer furnace wall of the vacuum furnace to the set temperature, the set temperature difference is kept between the outer furnace wall and the vacuum cavity, and it is ensured that workpieces are evenly heated. Therefore, the workpiece can be uniformly heated, and the heat treatment quality of the workpiece is high.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum heat treatment equipment, and particularly relates to a vacuum heat treatment equipment. Background Art

[0002] Vacuum heat treatment equipment is an advanced process equipment that heats, holds, and cools workpiece materials in a sealed vacuum environment, fundamentally solving defects such as oxidation, decarburization, and surface contamination caused by air contact in traditional heat treatment processes. Since active gases such as oxygen and water vapor can be completely isolated throughout the heat treatment process, the surface of the workpiece can maintain its original bright and clean state, and at the same time, material property deterioration phenomena such as hydrogen embrittlement can be effectively avoided. It is applicable to precision parts with strict requirements for surface quality and dimensional accuracy, such as surgical instruments, optical lenses, aerospace precision components, etc., and has a wide range of applications.

[0003] However, currently, large industrial vacuum heat treatment equipment usually adopts an overall seal, with heating elements and insulation layers arranged inside the vacuum furnace. As a result, it is difficult to meet the oxygen content standard after evacuation, and multiple evacuations may be required. Moreover, during high-temperature operation, due to the presence of the insulation layer, the oxygen content is unstable, the temperature control accuracy is insufficient, and the temperature uniformity is unstable, seriously affecting the heat treatment quality of the workpiece. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a vacuum heat treatment equipment. A muffle cover is fixedly arranged inside the vacuum furnace, and a heat preservation cover is arranged outside the vacuum furnace. The inner side wall of the heat preservation cover is fixedly provided with heaters, effectively improving the temperature uniformity, evacuation speed, and oxygen content stability of the vacuum furnace, and solving the technical problem of low heat treatment quality of existing workpieces caused by uneven heating.

[0005] To achieve the above purpose, the present invention provides a vacuum heat treatment equipment, including:

[0006] A vacuum furnace, in which a vacuum chamber is formed. A muffle cover is fixedly arranged inside the vacuum chamber. The muffle cover extends along the axial direction of the vacuum chamber, and an annular chamber is formed between the muffle cover and the vacuum chamber. An axial fan is provided at the air inlet of the vacuum chamber, and both ends of the muffle cover are respectively communicated with the air inlet and the annular chamber;

[0007] A heat preservation cover, which covers the outer periphery of the vacuum furnace; a plurality of heaters are fixedly arranged on the inner side wall of the heat preservation cover, and all the heaters are evenly distributed along the circumferential direction of the vacuum furnace; when all the heaters heat the outer furnace wall of the vacuum furnace to a set temperature, a set temperature difference is maintained between the outer furnace wall and the vacuum chamber.

[0008] In some embodiments, the heater includes a plurality of plate heaters and a plurality of column heaters; the heat preservation cover includes a front side plate, a top side plate, a rear side plate and a bottom side plate that are connected in sequence; plate heaters are fixed on the front side plate, the top side plate and the rear side plate, and all the plate heaters are uniformly distributed along the axial direction of the vacuum chamber; column heaters are fixed on the bottom side plate, and all the column heaters are uniformly distributed along the axial direction of the vacuum chamber.

[0009] In some embodiments, the front side plate, the top side plate and the rear side plate are all provided with a plurality of protruding rib strips distributed in a grid pattern, and the plate heaters are fixed on the protruding rib strips.

[0010] In some embodiments, the sum of the heating powers of all the plate heaters provided on the front side plate, the top side plate and the rear side plate is equal, and is equal to the sum of the heating powers of all the column heaters provided on the bottom side plate.

[0011] In some embodiments, the side spacing distance of the plate heaters provided on the front side plate and the rear side plate is less than the top spacing distance of the plate heaters provided on the top side plate.

[0012] In some embodiments, the heat preservation cover includes an upper cover shell and a lower cover shell that are distributed up and down. An upper flanging is integrally formed at the open end of the upper cover shell, and a lower flanging is integrally formed at the open end of the lower cover shell. The upper flanging abuts against the lower flanging; and the upper flanging and the lower flanging are detachably connected by a plurality of connecting bolts.

[0013] In some embodiments, a connector is fixed at the air inlet. The connector is provided with a fan interface and a workpiece temperature measuring port. The fan interface is connected to an axial fan, and the workpiece temperature measuring port is connected with a workpiece temperature detecting member. The workpiece temperature detecting member is used to detect the current heating temperature of the workpiece in the muffle cover;

[0014] When the workpiece temperature detecting member detects that the current heating temperature is lower than the set heating temperature, the workpiece temperature detecting member feeds back a temperature signal to the controller, and the controller adjusts the powers of the axial fan and all the heaters after judgment and processing.

[0015] In some embodiments, the connector is provided with a cold air inlet and a hot air outlet. The cold air inlet and the hot air outlet are connected through a cooling pipeline, and the cooling pipeline is provided with a heat exchanger; the controller is connected with a cooling time detecting member. The cooling time detecting member is used to detect whether the current heating temperature of the workpiece is maintained within the set cooling temperature range within a set time period;

[0016] When the workpiece temperature detector detects that the current heating temperature is within the set cooling temperature range, and the cooling time detector detects that the current heating temperature is maintained within the set cooling temperature range within the set time period, the workpiece temperature detector feeds back a temperature signal to the controller. At the same time, the cooling time detector feeds back a time signal to the controller. After judgment and processing by the controller, the axial fan is turned on. The axial fan blows the high-temperature air flow in the muffle into the hot air outlet. The high-temperature air flow flows into the heat exchanger along the cooling pipeline, generates a low-temperature air flow after heat exchange with the heat exchanger, and the low-temperature air flow flows into the muffle along the cold air inlet to conduct heat exchange with the high-temperature air flow in the muffle.

[0017] In some embodiments, the connector is further provided with an oxygen content detection port, a vacuum interface and a nitrogen inlet. The oxygen content detection port is connected with an oxygen content detector, the vacuum interface is connected with a vacuum pump, and the oxygen content detector is used for detecting the current oxygen content in the vacuum chamber; the nitrogen inlet is connected with a nitrogen filling pipe, and the nitrogen filling pipe is provided with a nitrogen filling valve;

[0018] When the workpiece temperature detector detects that the current heating temperature is at the set heat treatment temperature, the workpiece temperature detector feeds back a temperature signal to the controller. After judgment and processing by the controller, the vacuum pump is turned on, and the vacuum pump extracts the oxygen in the vacuum chamber through the vacuum interface;

[0019] When the oxygen content detector detects that the current oxygen content exceeds the set oxygen content, the oxygen content detector feeds back an oxygen content signal to the controller. After judgment and processing by the controller, the vacuum pump is turned off, and the nitrogen filling valve is turned on. The nitrogen filling pipe fills nitrogen into the vacuum chamber along the nitrogen filling interface.

[0020] In some embodiments, the connector is further provided with an atmosphere temperature detection port, and the atmosphere temperature detection port is connected with a nitrogen temperature detector, and the nitrogen temperature detector is used for detecting the current nitrogen temperature in the vacuum chamber;

[0021] When the nitrogen temperature detector detects that the current nitrogen temperature exceeds the set nitrogen temperature, the nitrogen temperature detector feeds back a signal to the controller. After judgment and processing by the controller, the alarm is started.

[0022] In some embodiments, the connector is further provided with a safety explosion-proof port, and the safety explosion-proof port is connected with an explosion-proof valve; when the pressure inside the vacuum furnace exceeds the set safety pressure, the explosion-proof valve opens.

[0023] In some embodiments, a support platform is fixedly arranged in the muffle; further included is a material transfer device for feeding the workpiece onto the support platform or taking the workpiece out of the support platform. The material transfer device includes:

[0024] A trolley, the bottom of the trolley is provided with running wheels, and the running wheels move along the first direction;

[0025] The moving frame is arranged on the trolley. The bottom of the moving frame is provided with moving wheels, and the moving wheels cooperate with the guiding rails arranged on the top of the trolley. The guiding rails guide the moving wheels to move in the second direction.

[0026] The material trolley is arranged on the moving frame. The bottom of the material trolley is provided with rolling wheels, and the rolling wheels cooperate with the guiding rails arranged on the top of the moving frame. The guiding rails guide the rolling wheels to move closer to or away from the support platform in the second direction.

[0027] The driving cylinder is fixedly arranged on the moving frame, and a hook is hinged to the end of the driving cylinder. When the hook hooks the material trolley, the driving cylinder drives the material trolley to move relative to the moving frame in the second direction to approach or move away from the support platform.

[0028] The first direction is perpendicular to the second direction, and the second direction is parallel to the axis of the vacuum furnace.

[0029] Compared with the background technology, the present invention mainly makes two improvements to the structure of the vacuum heat treatment equipment. The specific improvement contents are as follows:

[0030] First, a muffle cover is added in the vacuum chamber of the vacuum furnace. The muffle cover extends along the axis of the vacuum chamber. An annular chamber is formed between the muffle cover and the vacuum chamber. The air inlet of the vacuum chamber is provided with an axial fan. The two ends of the muffle cover are respectively connected to the air inlet and the annular chamber. When the axial fan rotates, relying on the pressure difference generated by rotation, the axial fan sucks the high-temperature air flow from the air inlet of the vacuum chamber into the muffle cover. The muffle cover uses its side wall as a physical boundary in the vacuum chamber to limit the free diffusion of the high-temperature air flow, forcing the high-temperature air flow to flow directionally along the muffle cover and then blowing into the vacuum chamber through the muffle cover, forming a circulating air path between the muffle cover and the vacuum furnace, enhancing the convective heat transfer efficiency, quickly balancing the temperature difference in the vacuum furnace, avoiding excessive local temperature in the vacuum furnace, ensuring that the high-temperature air flow evenly covers the workpiece, improving the temperature uniformity of the vacuum furnace, reducing the thermal stress deformation of the workpiece, and effectively improving the heat treatment quality of the workpiece.

[0031] Second, a heat preservation cover is added to the outer periphery of the vacuum furnace, and several heaters are added to the inner side wall of the heat preservation cover. There are no other impurities in the vacuum furnace except for workpiece impurities. Only a single vacuum pumping is required to meet the heat treatment requirements, and the oxygen content is stable. Therefore, each heat treatment process is relatively stable. All the heaters are evenly distributed along the circumferential direction of the vacuum furnace to heat the outer furnace wall of the vacuum furnace. When the heating temperature of the outer furnace wall reaches the set temperature, a set temperature difference is maintained between the outer furnace wall and the vacuum chamber. By adjusting the temperature of the outer furnace wall of the vacuum furnace, a constant temperature difference is maintained inside and outside the vacuum furnace, ensuring accurate temperature control in the vacuum furnace, ensuring uniform heating of the workpiece, preventing residual stress from being generated in the internal components of the workpiece due to uneven temperature, and also effectively improving the heat treatment quality of the workpiece. In addition, there is no heat preservation material inside the vacuum furnace, with small heat storage, which is more conducive to temperature control and can also effectively improve the heat treatment quality of the workpiece.

[0032] Therefore, through the synergistic effect of the muffle and the heat insulation cover, and by placing the heat insulation cover on the outer periphery of the vacuum furnace, the present invention effectively improves the temperature uniformity, the vacuum pumping speed, and the oxygen content stability of the vacuum furnace. The workpieces can be heated evenly, the oxygen content is stable during the heat treatment process, and each treatment process is stable, thereby improving the heat treatment quality of the workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the provided drawings.

[0034] Figure 1 Schematic diagram of the vacuum heat treatment equipment provided by a specific embodiment of the present invention;

[0035] Figure 2 For Figure 1 Assembly drawing of the remaining components after removing the material transfer device;

[0036] Figure 3 For Figure 1 Assembly drawing of the vacuum furnace, the muffle, and the heat insulation cover in

[0037] Figure 4 For Figure 3 Side view of

[0038] Figure 5 For Figure 1 Distribution schematic diagram of the plate heaters on the rear side plate of the heat insulation cover in

[0039] Figure 6 For Figure 1 Distribution schematic diagram of the plate heaters on the front side plate of the heat insulation cover in

[0040] Figure 7 For Figure 1 Distribution schematic diagram of the column heaters on the bottom side plate of the heat insulation cover in

[0041] Figure 8 For Figure 1 Partial enlarged view of the connection between the top side plate and the front side plate of the heat insulation cover in

[0042] Figure 9 For Figure 1 Schematic diagram of the heat insulation cover in

[0043] Figure 10 For Figure 9 Partial enlarged view of the connection between the upper cover shell and the lower cover shell in

[0044] Figure 11 is Figure 1 a schematic diagram of a medium vacuum furnace;

[0045] Figure 12 is Figure 11 the front view of the connector;

[0046] Figure 13 is Figure 1 a schematic diagram of the material transfer device in;

[0047] Figure 14 is Figure 1 the state diagram when the material cart moves along the moving frame in.

[0048] The reference numerals are as follows:

[0049] vacuum furnace 1, muffle 2, axial fan 3, thermal insulation cover 4, heater 5, connector 6, support platform 7 and material transfer device 8;

[0050] vacuum chamber 11;

[0051] front side plate 41, top side plate 42, rear side plate 43, bottom side plate 44, convex rib 45, upper housing 46 and lower housing 47;

[0052] upper flanging 461;

[0053] lower flanging 471;

[0054] plate heater 51 and column heater 52;

[0055] fan interface 61, workpiece temperature measurement port 62, cold air inlet 63, hot air outlet 64, oxygen content detection port 65, vacuum interface 66, nitrogen inlet 67, atmosphere temperature detection port 68 and safety explosion-proof port 69;

[0056] trolley 81, moving frame 82, material cart 83, driving cylinder 84 and hook 85;

[0057] running wheel 811;

[0058] moving wheel 821;

[0059] rolling wheel 831. Specific embodiments

[0060] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0061] To enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] An embodiment of the present invention discloses a vacuum heat treatment device. As shown in the attached Figures 1 to 4 figure, it includes a vacuum furnace 1 and a heat preservation cover 4. The vacuum furnace 1 is cylindrical, with an air inlet at one end and a furnace door at the other end. A vacuum chamber 11 is formed inside the vacuum furnace 1, and the inside of the vacuum chamber 11 is a vacuum environment. By placing the workpiece in the vacuum environment for heating, a high-quality heat treatment effect without oxidation and decarburization can be achieved.

[0063] Crucially, a muffle cover 2 is fixedly arranged inside the vacuum chamber 11. The muffle cover 2 extends along the axial direction of the vacuum chamber 11, but the axial length of the muffle cover 2 is less than the axial length of the vacuum chamber 11. The cross-section of the muffle cover 2 is preferably rectangular, and the cross-sectional area of the muffle cover 2 is less than the cross-sectional area of the vacuum chamber 11, so that an annular chamber is formed between the muffle cover 2 and the vacuum chamber 11. An axial fan 3 is provided at the air inlet of the vacuum chamber 11. The axial fan 3 is preferably an axial flow fan, but is not limited thereto. Both ends of the muffle cover 2 are respectively communicated with the air inlet and the annular chamber.

[0064] When the axial fan 3 rotates, relying on the pressure difference generated by the rotation, the axial fan 3 sucks the high-temperature air flow from the air inlet of the vacuum chamber 11 into the muffle cover 2. The muffle cover 2 uses its side wall as a physical boundary inside the vacuum chamber 11 to limit the free diffusion of the high-temperature air flow, forcing the high-temperature air flow to flow directionally along the muffle cover 2, and then blowing into the vacuum chamber 11 through the muffle cover 2, forming a circulating air path between the muffle cover 2 and the vacuum furnace 1, enhancing the convective heat transfer efficiency, quickly balancing the temperature difference inside the vacuum furnace 1, avoiding excessive local temperature inside the vacuum furnace 1, ensuring that the high-temperature air flow uniformly covers the workpiece, improving the temperature uniformity of the vacuum furnace 1, reducing the thermal stress deformation of the workpiece, and effectively improving the heat treatment quality of the workpiece.

[0065] The heat preservation cover 4 covers the outer periphery of the vacuum furnace 1. A plurality of heaters 5 are fixedly arranged on the inner side wall of the heat preservation cover 4. Except for workpiece impurities, there are no any other impurities inside the vacuum furnace 1. Only a single vacuum pumping is required to meet the heat treatment requirements, and the oxygen content is stable, so each heat treatment process is relatively stable. In addition, there is no heat preservation material inside the vacuum furnace 1, with small heat storage, which is more conducive to temperature control and can also effectively improve the heat treatment quality of the workpiece.

[0066] All the heaters 5 are evenly distributed along the circumferential direction of the vacuum furnace 1 to perform circumferential heating on the outer furnace wall of the vacuum furnace 1. Specifically, the axial length of the heat preservation cover 4 is less than the axial length of the vacuum furnace 1. The end of the vacuum furnace 1 with the air inlet is located inside the heat preservation cover 4, and the furnace door of the vacuum furnace 1 is located inside the heat preservation cover 4 to ensure that the furnace door can be opened and closed normally.

[0067] When the heating temperature of the outer furnace wall reaches the set temperature, a set temperature difference is maintained between the outer furnace wall and the vacuum chamber 11. By adjusting the temperature of the outer furnace wall of the vacuum furnace 1, a constant temperature difference is maintained inside and outside the vacuum furnace 1, ensuring precise temperature control inside the vacuum furnace, ensuring uniform heating of the workpiece, preventing residual stress from being generated in the internal components of the workpiece due to uneven temperature, and effectively improving the heat treatment quality of the workpiece.

[0068] In summary, through the synergistic effect of the muffle 2 and the heat preservation cover 4, and by placing the heat preservation cover 4 on the outer periphery of the vacuum furnace 1, the temperature uniformity, vacuum pumping speed and oxygen content stability of the vacuum furnace 1 are effectively improved, enabling the workpiece to be uniformly heated in the vacuum furnace 1 and improving the heat treatment quality of the workpiece.

[0069] As a preferred embodiment, as shown in the appendix Figures 5 to 7 The heater 5 includes a plurality of plate heaters 51 and a plurality of column heaters 52. Among them, the plate heater 51 uses a planar resistance heating element to generate Joule heat when powered on, and transfers the heat to the workpiece in a surface radiation manner. The column heater 52 uses a rod-shaped resistor to generate uniform axial heat when powered on, and transfers the heat to the workpiece through radiation and convection.

[0070] It should be noted that there are differences in the distribution positions of the plate heaters 51 and the column heaters 52. Specifically, the heat preservation cover 4 includes a front side plate 41, a top side plate 42, a rear side plate 43 and a bottom side plate 44 that are connected in sequence. Adjacent side plates are perpendicular to each other, and the cross-section of the heat preservation cover 4 is rectangular. Considering that the surfaces of the front side plate 41, the top side plate 42 and the rear side plate 43 are flat and there is almost no interference, the front side plate 41, the top side plate 42 and the rear side plate 43 are all fixed with plate heaters 51. As shown in the appendix Figure 5 and 6 As shown, for each side plate, all the plate heaters 51 are uniformly distributed along the axial direction of the vacuum chamber 11, so that the plate heaters 51 heat the outer furnace wall in a surrounding manner. The bottom side plate 44 of the heat preservation cover 4 is provided with a plurality of support columns for supporting the muffle 2. Considering that the setting of the support columns will interfere with the plate heaters 51, the bottom side plate 44 is fixed with column heaters 52, and all the column heaters 52 are uniformly distributed along the axial direction of the vacuum chamber 11, as shown in the appendix Figure 7 shown.

[0071] The front side plate 41, the top side plate 42, and the rear side plate 43 are all provided with a number of raised rib strips 45 distributed in a grid pattern. The plate heater 51 is fixedly arranged on the raised rib strips 45, which can not only enhance the mechanical strength of each side plate, effectively resist thermal deformation at high temperatures, and extend the service life of the heat insulation cover 4, but also utilize the gaps between the raised rib strips 45 to compensate for the lateral differential expansion between the plate heater 51 and each side plate, avoiding cracking of each side plate caused by thermal stress concentration. In addition, the setting of the raised rib strips 45 can also improve the surface roughness of the side plate where they are located, break the laminar boundary layer, enhance gas disturbance, and improve the temperature uniformity of the plate heater 51.

[0072] The sum of the heating powers of all the plate heaters 51 provided on the front side plate 41, the top side plate 42, and the rear side plate 43 is equal to the sum of the heating powers of all the column heaters 52 provided on the bottom side plate 44, ensuring that the heat generation of each side plate of the heat insulation cover 4 is the same and guaranteeing uniform heating of the outer furnace wall of the vacuum furnace 1.

[0073] The side spacing distance between the plate heaters 51 provided on the front side plate 41 and the rear side plate 43 is less than the top spacing distance between the plate heaters 51 provided on the top side plate 42. As shown in the appendix Figure 8 shown, a wiring groove is formed between two adjacent plate heaters 51 on the top side plate 42, facilitating wiring and leaving space for temperature measurement.

[0074] As a preferred embodiment, as shown in the appendix Figure 9 and 10 shown, the heat insulation cover 4 is of a split structure. The heat insulation cover 4 includes an upper cover shell 46 and a lower cover shell 47 distributed up and down. An upward flanging 461 is integrally formed at the open end of the upper cover shell 46, and a downward flanging 471 is integrally formed at the open end of the lower cover shell 47. The upward flanging 461 abuts against the downward flanging 471; and the upward flanging 461 and the downward flanging 471 are detachably connected by a number of connecting bolts, which is convenient for disassembly and reduces the maintenance difficulty of each heater 5.

[0075] As shown in the appendix Figure 11 and 12 shown, a connector 6 is fixedly arranged at the air inlet. The connector 6 is provided with a fan interface 61 and a workpiece temperature measurement port 62. The fan interface 61 is connected to the axial fan 3, and the workpiece temperature measurement port 62 is connected to a workpiece temperature detection component. The workpiece temperature detection component is used to detect the current heating temperature of the workpiece in the muffle 2. The workpiece temperature detection component can specifically be a temperature sensor, but is not limited thereto.

[0076] When the workpiece temperature detector detects that the current heating temperature is lower than the set heating temperature, it means that the heating temperature in the muffle 2 is too low. At this time, the workpiece temperature detector feeds back a temperature signal to the controller. After receiving this signal, the controller makes a judgment and sends an instruction to the axial fan 3 and all heaters 5 to adjust the power of both the axial fan 3 and all heaters 5. The heat is radiated and conducted into the muffle 2. Under the action of the axial fan 3, the high-temperature airflow circulates in the muffle 2 and the vacuum furnace 1 to achieve cyclic heating of the workpiece, ensuring the stability of the heating temperature of the workpiece and better heat treatment quality.

[0077] The connector 6 is provided with a cold air inlet 63 and a hot air outlet 64. The cold air inlet 63 is connected to the hot air outlet 64 through a cooling pipeline, and the cooling pipeline is provided with a heat exchanger. The controller is connected with a cooling time detector, and the cooling time detector is used to detect whether the current heating temperature of the workpiece remains within the set cooling temperature range within a set time period. Specifically, it can be a timer.

[0078] When the workpiece temperature detector detects that the current heating temperature is within the set cooling temperature range, and the cooling time detector detects that the current heating temperature remains within the set cooling temperature range within the set time period, it is in the cooling stage at this time, which means that the heating temperature of the workpiece in the muffle 2 is too high. The workpiece temperature detector feeds back a temperature signal to the controller, and at the same time, the cooling time detector feeds back a time signal to the controller. After receiving the two signals, the controller makes a judgment and sends an instruction to the axial fan 3 to control the axial fan 3 to automatically open. The axial fan 3 blows the high-temperature airflow in the muffle 2 into the hot air outlet 64. The high-temperature airflow flows into the heat exchanger along the cooling pipeline. The high-temperature airflow exchanges heat with the cooling medium in the heat exchanger. After the high-temperature airflow exchanges heat, it generates a low-temperature airflow. The low-temperature airflow flows into the muffle 2 along the cold air inlet 63, and the high-temperature airflow in the muffle 2 exchanges heat to reduce the heating temperature of the workpiece in the muffle 2, realizing the cooling cycle of the workpiece, ensuring the stability of the heating temperature of the workpiece, and being beneficial to improving the heat treatment quality of the workpiece.

[0079] The connector 6 is also provided with an oxygen content detection port 65, a vacuum interface 66 and a nitrogen inlet 67. The oxygen content detection port 65 is connected with an oxygen content detector, the vacuum interface 66 is connected with a vacuum pump, and the oxygen content detector is used to detect the current oxygen content in the vacuum chamber 11. Specifically, it can be an oxygen content detector. The nitrogen inlet 67 is connected with a nitrogen filling pipe, and the nitrogen filling pipe is provided with a nitrogen filling valve for controlling the on-off of the nitrogen filling pipe. The nitrogen filling valve can specifically be an electromagnetic valve.

[0080] When the workpiece temperature detector detects that the current heating temperature is at the set heat treatment temperature, the workpiece temperature detector feeds back a temperature signal to the controller. After judgment and processing, the controller turns on the vacuum pump, and the vacuum pump extracts the oxygen in the vacuum chamber 11 through the vacuum interface 66 to reduce the residual oxygen in the vacuum chamber 11;

[0081] When the oxygen content detection component detects that the current oxygen content exceeds the set oxygen content, it means that the oxygen content in the vacuum chamber 11 is qualified. At this time, the oxygen content detection component feeds back the oxygen content signal to the controller. After receiving the signal, the controller makes a judgment and sends an instruction to the vacuum pump and the nitrogen filling valve, automatically closing the vacuum pump and automatically opening the nitrogen filling valve. The nitrogen filling pipe fills nitrogen into the vacuum chamber 11 along the nitrogen filling interface, regulating the purity of nitrogen and the furnace pressure in the vacuum chamber 11 by increasing the nitrogen content, effectively protecting the workpiece and preventing the workpiece from oxidizing during the heat treatment process.

[0082] The connector 6 is also provided with an atmosphere temperature detection port 68, and the atmosphere temperature detection port 68 is connected with a nitrogen temperature detection component. The nitrogen temperature detection component is used to detect the current nitrogen temperature in the vacuum chamber 11. The nitrogen temperature detection component can specifically be a temperature sensor, but is not limited thereto.

[0083] When the nitrogen temperature detection component detects that the current nitrogen temperature exceeds the set nitrogen temperature, it means that the nitrogen temperature in the muffle 2 is too high. At this time, the nitrogen temperature detection component feeds back a signal to the controller. After receiving the signal, the controller makes a judgment and sends an instruction to the alarm, automatically turning on the alarm to remind the on-site personnel to timely know the nitrogen temperature in the furnace.

[0084] The connector 6 is also provided with a safety explosion-proof port 69, and the safety explosion-proof port 69 is connected with an explosion-proof valve; when the furnace pressure in the vacuum furnace 1 exceeds the set safety pressure, the explosion-proof valve opens to prevent the explosion risk caused by the abnormal pressure increase in the vacuum furnace 1 and ensure the safety of the vacuum furnace 1 and the personnel.

[0085] A support platform 7 is fixedly arranged in the muffle 2 for placing the workpiece.

[0086] The above-mentioned vacuum heat treatment equipment further includes a material transfer device 8 for feeding the workpiece onto the support platform 7 or taking the workpiece out of the support platform 7. The material transfer device 8 has two degrees of freedom. As a preferred embodiment, as shown in the appendix Figure 13 and 14As shown, the material transfer device 8 includes a trolley 81, a moving frame 82, a material cart 83 and a driving cylinder 84. Travel wheels 811 are provided at the bottom of the trolley 81, and the travel wheels 811 move along the first direction; the moving frame 82 is arranged on the trolley 81, and moving wheels 821 are provided at the bottom of the moving frame 82. The moving wheels 821 cooperate with the guide rails provided on the top of the trolley 81, and the guide rails guide the moving wheels 821 to move along the second direction; the material cart 83 is arranged on the moving frame 82, and rolling wheels 831 are provided at the bottom of the material cart 83. The rolling wheels 831 cooperate with the guide rails provided on the top of the moving frame 82, and the guide rails guide the rolling wheels 831 to move closer to or away from the support platform 7 along the second direction. A hook 85 is hinged to the end of the driving cylinder 84; when the hook 85 hooks the material cart 83, the driving cylinder 84 drives the material cart 83 to move relative to the moving frame 82 along the second direction to approach or move away from the support platform 7; the first direction is perpendicular to the second direction, and the second direction is parallel to the axis of the vacuum furnace 1. Of course, the structure of the material transfer device 8 is not limited to this. When the driving cylinder 84 disengages from the material cart 83, the hook 85 remains raised.

[0087] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0088] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be pointed out that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A vacuum heat treatment device, characterized in that, Comprising: A vacuum furnace (1), within which a vacuum chamber (11) is formed. A muffle cover (2) is fixedly provided within the vacuum chamber (11), and the muffle cover (2) extends along the axial direction of the vacuum chamber (11). An annular chamber is formed between the muffle cover (2) and the vacuum chamber (11). An axial fan (3) is provided at the air inlet of the vacuum chamber (11), and both ends of the muffle cover (2) are respectively communicated with the air inlet and the annular chamber. A heat preservation cover (4) is disposed outside the periphery of the vacuum furnace (1). A plurality of heaters (5) are fixedly provided on the inner side wall of the heat preservation cover (4), and all the heaters (5) are uniformly distributed along the circumferential direction of the vacuum furnace (1). When all the heaters (5) heat the outer furnace wall of the vacuum furnace (1) to a set temperature, a set temperature difference is maintained between the outer furnace wall and the vacuum chamber (11).

2. The vacuum heat treatment equipment according to claim 1, characterized in that, The heater (5) includes a plurality of plate heaters (51) and a plurality of column heaters (52). The heat preservation cover (4) includes a front side plate (41), a top side plate (42), a rear side plate (43), and a bottom side plate (44) that are connected in sequence. The front side plate (41), the top side plate (42), and the rear side plate (43) are fixedly provided with the plate heaters (51), and all the plate heaters (51) are uniformly distributed along the axial direction of the vacuum chamber (11). The bottom side plate (44) is fixedly provided with the column heaters (52), and all the column heaters (52) are uniformly distributed along the axial direction of the vacuum chamber (11).

3. The vacuum heat treatment equipment according to claim 2, characterized in that, A plurality of raised rib strips (45) distributed in a grid shape are provided on the front side plate (41), the top side plate (42), and the rear side plate (43), and the plate heater (51) is fixedly provided on the raised rib strips (45).

4. The vacuum heat treatment equipment according to claim 2, characterized in that, The sum of the heating powers of all the plate heaters (51) provided on the front side plate (41), the top side plate (42), and the rear side plate (43) is equal, and is equal to the sum of the heating powers of all the column heaters (52) provided on the bottom side plate (44).

5. The vacuum heat treatment equipment according to claim 2, characterized in that, The side interval distance of the plate heaters (51) provided on the front side plate (41) and the rear side plate (43) is less than the top interval distance of the plate heaters (51) provided on the top side plate (42).

6. The vacuum heat treatment equipment according to any one of claims 1 to 5, characterized in that The heat preservation cover (4) includes an upper cover shell (46) and a lower cover shell (47) that are distributed up and down. An upward flanging (461) is integrally formed at the open end of the upper cover shell (46), and a downward flanging (471) is integrally formed at the open end of the lower cover shell (47). The upward flanging (461) abuts against the downward flanging (471), and the upward flanging (461) and the downward flanging (471) are detachably connected by a plurality of connecting bolts.

7. The vacuum heat treatment equipment according to any one of claims 1 to 5, characterized in that, A connector (6) is fixedly installed at the air inlet. The connector (6) is provided with a fan interface (61) and a workpiece temperature measurement port (62). The fan interface (61) is connected to the axial fan (3), and the workpiece temperature measurement port (62) is connected to a workpiece temperature detection component, which is used to detect the current heating temperature of the workpiece in the muffle (2). When the workpiece temperature detection component detects that the current heating temperature is lower than the set heating temperature, the workpiece temperature detection component feeds back a temperature signal to the controller. After judgment and processing by the controller, the power of the axial fan (3) and all the heaters (5) is adjusted.

8. The vacuum heat treatment equipment according to claim 7, characterized in that, The connector (6) is provided with a cold air inlet (63) and a hot air outlet (64). The cold air inlet (63) and the hot air outlet (64) are connected through a cooling pipeline, and the cooling pipeline is provided with a heat exchanger. The controller is connected to a cooling time detection component, which is used to detect whether the current heating temperature of the workpiece remains within the set cooling temperature range within a set time period. When the workpiece temperature detection component detects that the current heating temperature is within the set cooling temperature range, and the cooling time detection component detects that the current heating temperature remains within the set cooling temperature range within the set time period, the workpiece temperature detection component feeds back a temperature signal to the controller, and at the same time the cooling time detection component feeds back a time signal to the controller. After judgment and processing by the controller, the axial fan (3) is turned on. The axial fan (3) blows the high-temperature air flow in the muffle (2) into the hot air outlet (64). The high-temperature air flow flows into the heat exchanger along the cooling pipeline, generates a low-temperature air flow after heat exchange with the heat exchanger, and the low-temperature air flow flows into the muffle (2) along the cold air inlet (63) for heat exchange with the high-temperature air flow in the muffle (2).

9. The vacuum heat treatment equipment according to claim 7, characterized in that, The connector (6) is further provided with an oxygen content detection port (65), a vacuum interface (66) and a nitrogen inlet (67). The oxygen content detection port (65) is connected to an oxygen content detection component, the vacuum interface (66) is connected to a vacuum pump, and the oxygen content detection component is used to detect the current oxygen content in the vacuum chamber (11). The nitrogen inlet (67) is connected to a nitrogen filling pipe, and the nitrogen filling pipe is provided with a nitrogen filling valve. When the workpiece temperature detection component detects that the current heating temperature is at the set heat treatment temperature, the workpiece temperature detection component feeds back a temperature signal to the controller. After judgment and processing by the controller, the vacuum pump is turned on, and the vacuum pump extracts the oxygen in the vacuum chamber (11) through the vacuum interface (66). When the oxygen content detection component detects that the current oxygen content exceeds the set oxygen content, the oxygen content detection component feeds back an oxygen content signal to the controller. After judgment and processing by the controller, the vacuum pump is turned off, and the nitrogen filling valve is opened, and the nitrogen filling pipe fills nitrogen into the vacuum chamber (11) along the nitrogen filling interface.

10. The vacuum heat treatment equipment according to claim 7, characterized in that, The connector (6) is further provided with an atmosphere temperature detection port (68), and a nitrogen temperature detector is connected to the atmosphere temperature detection port (68) for detecting the current nitrogen temperature in the vacuum chamber (11). When the nitrogen temperature detector detects that the current nitrogen temperature exceeds the set nitrogen temperature, the nitrogen temperature detector feeds back a signal to the controller, and the controller starts an alarm after judgment and processing.

11. The vacuum heat treatment equipment according to claim 7, wherein The connector (6) is further provided with a safety explosion-proof port (69), and an explosion-proof valve is connected to the safety explosion-proof port (69); when the pressure in the furnace of the vacuum furnace (1) exceeds the set safety pressure, the explosion-proof valve opens.

12. The vacuum heat treatment equipment according to any one of claims 1 to 5, characterized in that, A support platform (7) is fixedly arranged in the muffle (2); further included is a material transfer device (8) for feeding a workpiece onto the support platform (7) or taking the workpiece out of the support platform (7), and the material transfer device (8) includes: A trolley (81), the bottom of the trolley (81) is provided with running wheels (811), and the running wheels (811) move along a first direction; A moving frame (82) is arranged on the trolley (81), the bottom of the moving frame (82) is provided with moving wheels (821), and the moving wheels (821) cooperate with a guiding rail arranged on the top of the trolley (81), and the guiding rail guides the moving wheels (821) to move along a second direction; A material car (83) is arranged on the moving frame (82), the bottom of the material car (83) is provided with rolling wheels (831), and the rolling wheels (831) cooperate with a guiding rail arranged on the top of the moving frame (82), and the guiding rail guides the rolling wheels (831) to move along the second direction to approach or move away from the support platform (7); A driving cylinder (84) is fixedly arranged on the moving frame (82), and a hook (85) is hinged to the end of the driving cylinder (84); when the hook (85) hooks the material car (83), the driving cylinder (84) drives the material car (83) to move along the second direction relative to the moving frame (82) to approach or move away from the support platform (7); the first direction is perpendicular to the second direction, and the second direction is parallel to the axis of the vacuum furnace (1).

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