Continuous heat treatment carburizing furnace combining pusher and roller bar

Abstract

The utility model provides a kind of continuous heat treatment carburizing furnace of push disc and roller combination, including furnace body, furnace body includes coaxially arranged push disc section and roller section, push disc section has feeding area, heating zone, strong carburizing area and high-temperature diffusion zone, and push disc section is equipped with the material tray slide way of through each area, feeding area outside is equipped with push rod mechanism;Roller section has cooling diffusion zone, heat preservation zone and quenching zone, each area in roller section is equipped with roller transmission mechanism, and the roller transmission mechanism of its adjacent two areas is linked, and the roller transmission mechanism of cooling diffusion zone is linked with the material tray slide way of high-temperature diffusion zone;Feeding area, heating zone, strong carburizing area, high-temperature diffusion zone, cooling diffusion zone, heat preservation zone and quenching zone are isolated between every adjacent two areas by isolation structure.The continuous heat treatment carburizing furnace adopts straight-through layout to reduce arrangement space, while having push disc furnace energy-saving features, realize carburizing process and workpiece mass production automation.

Description

Technical Field

[0001] This utility model belongs to the field of heat treatment carburizing production technology, specifically relating to a continuous heat treatment carburizing furnace combining a pusher plate and rollers. Background Technology

[0002] There are generally two types of continuous carburizing production lines for heat treatment: pusher-type carburizing furnaces and roller carburizing furnaces. Pusher-type carburizing furnaces often employ a multi-section, multi-turn layout. This layout ensures temperature and atmosphere stability in each zone, but it occupies a large space. Workpieces are placed on trays, which are propelled forward by pushers within the furnace. Trays move forward one after another, and transfer is done by side pushers to another zone. Each zone has its own pusher. Pusher-type automatic carburizing lines are characterized by high output and low overall energy consumption, resulting in lower production costs compared to other furnace types. Their disadvantage is their large space requirement. Roller carburizing furnaces, on the other hand, use a straight-through structure, occupying less space. The rollers directly support the trays, and a forward motor drives the rollers to rotate. The rollers, through friction, propel the pusher, thus transferring the workpieces along the production line. Roller carburizing furnaces are advantageous due to their wide applicability, versatility, accurate positioning, and stable transmission. However, their output is lower than pusher-type furnaces, and their energy consumption is higher. However, in reality, many users are limited by factory location and still require high output and low overall operating costs for pusher carburizing furnaces. Existing continuous heat treatment carburizing production lines cannot meet the needs of these users. Utility Model Content

[0003] The purpose of this invention is to provide a continuous heat treatment carburizing furnace that combines a pusher plate and rollers, which can at least solve some of the defects existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A continuous heat treatment carburizing furnace combining a pusher plate and rollers includes a furnace body comprising a pusher plate section and a roller section arranged coaxially. The pusher plate section has a feeding zone, a heating zone, a strong carburizing zone, and a high-temperature diffusion zone arranged sequentially along its axis. A material tray slide passing through each zone of the pusher plate section is provided within the pusher plate section. A push rod mechanism for moving workpieces on the material tray slide is provided outside the feeding zone. The roller section has a cooling diffusion zone, a heat preservation zone, and a quenching zone arranged sequentially along its axis. Each zone of the roller section is equipped with a roller drive mechanism, and the roller drive mechanisms of adjacent zones are connected. The roller drive mechanism of the cooling diffusion zone is connected to the material tray slide of the high-temperature diffusion zone. Each pair of adjacent zones (feeding zone, heating zone, strong carburizing zone, high-temperature diffusion zone, cooling diffusion zone, heat preservation zone, and quenching zone) is isolated by an isolation structure.

[0005] Furthermore, the feeding zone and the heating zone, as well as the two adjacent zones of the roller section, are isolated by intermediate isolation doors. Isolation walls are provided between the heating zone and the strong carburizing zone, and between the strong carburizing zone and the high-temperature diffusion zone. The isolation walls have openings for the workpiece to pass through.

[0006] Furthermore, the bottom of the feeding area is provided with a feeding port, and the bottom of the feeding area is provided with a bottom feeding mechanism for lifting and feeding, which can be sealed to the feeding port.

[0007] Furthermore, the cooling diffusion zone is equipped with heating radiation tubes for heating and heat preservation of the workpiece and cooling tubes for cooling the workpiece.

[0008] Furthermore, the cooling pipe includes an inner pipe and an outer pipe. An air inlet is provided at the upper part of the outer pipe, and the lower end of the outer pipe is connected to the lower end of the inner pipe. The upper end of the inner pipe is connected to the exhaust pipe of the exhaust cooling mechanism located outside the cooling diffusion zone.

[0009] Furthermore, the roller drive mechanism includes a plurality of rollers arranged side by side along the furnace body axis and a roller drive assembly for driving the rollers to rotate. The rollers are arranged perpendicular to the furnace body axis and pass through the two side walls of the furnace body. Both ends of the rollers are sealed to the furnace body through sealed bearing assemblies. One end of the roller closer to the roller drive assembly is fixed to the sealed bearing assembly, and the other end of the roller away from the roller drive assembly is slidably connected to the sealed bearing assembly.

[0010] Furthermore, the roller drive assembly includes a chain, a chain guide plate, and a drive motor that drives the chain to rotate along the chain guide plate. The chain guide plate is arranged parallel to the furnace body axis, and the drive end of each roller is rotatably connected to the chain via a sprocket.

[0011] Furthermore, the top of the heating zone, the strong carburizing zone, the high-temperature diffusion zone, the cooling diffusion zone, and the heat preservation zone are all equipped with an air supply mechanism and a circulating fan mechanism.

[0012] Furthermore, the feeding area is equipped with a waste gas emission mechanism to maintain positive pressure inside the furnace.

[0013] Furthermore, the furnace body is provided with a carbon black burning mechanism for introducing air into each zone of the furnace body to burn the carbon deposits inside the furnace.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model provides a continuous heat treatment carburizing furnace that combines a pusher plate and a roller, which combines the advantages of a pusher plate carburizing furnace production line and a roller carburizing furnace production line. The overall layout is straight-through, with a pusher plate structure in the front and a roller structure in the rear, which occupies little space. At the same time, it has the characteristics of high output and energy saving of a pusher plate furnace. It adopts multi-segment zone control, which has low energy consumption and low overall production cost.

[0015] The present invention will be further described in detail below with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram of the continuous heat treatment carburizing furnace combining a pusher plate and rollers according to this utility model. Figure 2 This is a top view of the continuous heat treatment carburizing furnace combining a pusher plate and rollers according to this utility model. Figure 3 This is a schematic cross-sectional view of the push plate section and the isolation wall in an embodiment of this utility model; Figure 4 This is a schematic cross-sectional view of the cooling diffusion zone in an embodiment of this utility model; Figure 5 This is a schematic cross-sectional view of one end of the roller and the sealed bearing assembly slidingly connected in the roller transmission mechanism of this utility model embodiment; Figure 6 This is a schematic diagram of the structure of the roller drive assembly in an embodiment of this utility model; Figure 7 This is a partial schematic diagram of the connection between the roller and the roller drive assembly in an embodiment of this utility model; Figure 8 This is a schematic diagram of the connection of the cooling pipe in an embodiment of this utility model.

[0017] Explanation of reference numerals in the attached drawings: 1. Push rod mechanism; 2. Bottom feeding mechanism; 3. Workpiece; 4. Intermediate isolation door; 5. Insulating furnace lining; 6. Furnace shell; 7. Material tray slide; 8. Circulating fan mechanism; 9. Isolation wall; 10. Inspection door; 11. Gas supply mechanism; 12. Roller; 13. Material level detection mechanism; 14. Quenching tank; 15. Exhaust gas emission mechanism; 16. Carbon black burning mechanism; 17. Exhaust cooling mechanism; 18. Temperature and carbon potential control mechanism; 19. Guide rail guide brick; 20. Heating radiation tube; 21. Observation window; 22. Nitrogen pipeline; 23. Insulating sleeve; 24. Guide sleeve; 25. Cooling pipe; 26. Sealed bearing assembly; 27. Roller drive assembly; 28. Sliding sleeve; 29. ​​Sliding key; 30. Sealing sleeve; 31. Skeleton shaft seal; 32. Bearing; 33. Bearing sleeve; 34. Connecting sleeve; 35. Graphite ring; 36. Roller support plate; 37. Channel steel; 38. Chain tensioning mechanism; 39. Chain; 40. Drive motor; 41. Adjusting support plate; 42. Chain guide plate; 43. Roller support plate adjustment; 44. Sprocket; 45. Air inlet; 46. Outer pipe; 47. Inner pipe; 48. Air outlet; 49. Electric butterfly valve opening; 50. Fan. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0019] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, abutting connections, or integral connections. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this utility model, unless otherwise stated, "a plurality of" or "several" means two or more.

[0022] like Figure 1 and Figure 2 As shown, this embodiment provides a continuous heat treatment carburizing furnace combining a pusher plate and rollers, including a furnace body. The furnace body includes a pusher plate section and a roller section arranged coaxially to achieve a straight-through layout. It also adopts a multi-segment partitioned structure design. The pusher plate section has a feeding zone, a heating zone, a strong carburizing zone, and a high-temperature diffusion zone arranged sequentially along its axis. The pusher plate section is provided with a material tray slide 7 that runs through each zone of the pusher plate section. The outside of the feeding zone is provided with a push rod mechanism 1 that pushes the workpiece 3 to move on the material tray slide 7. The roller section has a cooling diffusion zone, a heat preservation zone, and a quenching zone arranged sequentially along its axis. Each zone of the roller section is provided with a roller drive mechanism, and the roller drive mechanisms of adjacent zones are connected. The roller drive mechanism of the cooling diffusion zone is connected to the material tray slide 7 of the high-temperature diffusion zone. Each pair of adjacent zones in the feeding zone, heating zone, strong carburizing zone, high-temperature diffusion zone, cooling diffusion zone, heat preservation zone, and quenching zone is isolated by an isolation structure.

[0023] In this embodiment, a zoned control is adopted to better adjust the carburizing process. The workpiece can be heated and carburized according to the process sequence requirements. The heating, atmosphere concentration, and carburizing time of each zone can be precisely controlled. The feeding zone is isolated into a single-plate workpiece chamber by an isolation structure for feeding workpiece 3. The heating zone is used to quickly heat workpiece 3 to the carburizing process temperature. The heating elements in this section are densely distributed on both sides of workpiece 3, and protective carrier gas is usually introduced. The strong carburizing zone is generally a rapid carburizing zone, which requires the introduction of enriched gas with a relatively high concentration in addition to the carrier gas. The high-temperature diffusion zone is where workpiece 3 is carburized and diffused in a relatively high-temperature environment. The workpiece 3 in the feeding zone, heating zone, strong carburizing zone, and high-temperature diffusion zone adopts a pusher plate structure design. Workpiece 3 is pushed forward one plate at a time on the material tray slide 7 that runs through these zones by the pushing force of the push rod mechanism 1. The cooling diffusion zone lowers the temperature of workpiece 3 to reach the process quenching temperature. It can also maintain the temperature for diffusion according to process requirements. The heat preservation zone maintains the temperature of workpiece 3 for diffusion, while the quenching zone quenches it. The workpiece 3 is driven by a roller drive structure within the cooling diffusion zone, heat preservation zone, and quenching zone. The roller drive mechanism in each zone drives the workpiece 3 to swing back and forth within its respective zone. After the process time is up, the roller drive mechanism finally rotates the workpiece to the quenching zone for quenching. This embodiment combines the advantages of a pusher-type carburizing furnace production line and a roller carburizing furnace production line. It adopts a straight-through layout, with a pusher structure at the front and a roller structure at the rear, resulting in a small footprint. It also features the high output and energy efficiency of a pusher furnace, employing multi-segment zone control for low energy consumption and overall low production costs.

[0024] In a more detailed implementation, the furnace shell 6 of the furnace body is constructed of welded composite steel plates, serving to support the carburizing furnace. It is an airtight, sealed structure, and the welding employs sealed welding techniques. All external connecting parts on the furnace body are also connected using a sealed structure to reduce oxygen infiltration. The workpiece 3 consists of a bottom material tray, an upper material frame, and internal workpieces. The material tray moves on the material tray slide 7 / roller bar 12.

[0025] In some embodiments, the push rod mechanism 1 is an electric push rod, including a lead screw, a push head and a motor. The push head is made of heat-resistant steel and is located inside the feeding zone to push the workpiece 3 in the feeding zone. The motor is located outside the feeding zone and drives the lead screw to rotate, thereby driving the push head to move back and forth. The connection between the push rod mechanism 1 and the feeding zone is a sealed connection.

[0026] As one specific implementation method, such as Figure 1 and Figure 2As shown, the feeding zone and the heating zone, as well as the cooling diffusion zone, heat preservation zone, and quenching zone of the roller section, are all separated by intermediate isolation doors 4. Simultaneously, isolation walls 9 are provided between the heating zone and the strong carburizing zone, and between the strong carburizing zone and the high-temperature diffusion zone, to reduce atmosphere mixing and temperature transfer between the zones. The isolation walls 9 have openings for the workpiece 3 to pass through. Specifically, in some embodiments, the intermediate isolation door 4 is made of heat-resistant steel and is motor-driven with position detection during lifting. Workpiece 3 enters the feeding area. After the process time is reached, and workpiece 3 in the cooling diffusion area is transferred to the heat preservation area, when there is no workpiece 3 in the cooling diffusion area, the two sets of intermediate isolation doors 4 between the feeding area and the heating area, and between the high temperature diffusion area and the cooling diffusion area are opened simultaneously. The push rod mechanism 1 pushes workpiece 3 from the feeding area to the heating area, and at the same time pushes workpiece 3 in the heating area, the strong carburizing area, and the high temperature diffusion area forward one after another. The roller transmission mechanism in the cooling diffusion area rotates at the same time, and its moving speed is the same as the pushing speed of the push rod mechanism 1. The foremost workpiece 3 in the high temperature diffusion area is passively pushed onto the roller 12 of the roller transmission mechanism in the cooling diffusion area. The push rod mechanism 1 moves backward, and at the same time, the workpiece 3 in the cooling diffusion area continues to move forward driven by the roller transmission mechanism. After that, the intermediate isolation doors 4 between the feeding area and the heating area, and between the high temperature diffusion area and the cooling diffusion area are closed, completing the feeding process. During the process time, the single-disc workpiece 3 in the cooling diffusion zone and the heat preservation zone swings back and forth in each zone by the roller transmission mechanism. After the set process cycle time is reached, the intermediate isolation door 4 between the heat preservation zone and the quenching zone is raised, and the roller transmission mechanisms of the two zones rotate simultaneously. The workpiece 3 in the heat preservation zone is transferred to the quenching zone, and the intermediate isolation door 4 between the heat preservation zone and the quenching zone is closed. The workpiece 3 is then quenched in the quenching zone. After there is no workpiece 3 in the heat preservation zone, the intermediate isolation door 4 between the cooling diffusion zone and the heat preservation zone is raised, and the roller transmission mechanisms of the two zones rotate simultaneously. The workpiece 3 in the cooling diffusion zone is transferred to the heat preservation zone.

[0027] In an optimized implementation, the feed inlet is located at the bottom of the feeding zone, and a bottom feeding mechanism 2 for lifting and lowering the feed is provided at the bottom of the feeding zone. The bottom feeding mechanism 2 can be sealed to the feed inlet. After the workpiece is transferred within the feeding zone, the bottom feeding mechanism 2 descends rapidly, pushing the workpiece 3 onto the platform of the bottom feeding mechanism 2. Then, the bottom feeding mechanism 2 rises rapidly from bottom to top, and the workpiece 3 enters the feeding zone. The bottom feeding mechanism 2 presses against the feed inlet, ensuring the feeding zone is sealed. Since the feed inlet of the feeding zone opens downwards, the atmosphere inside the furnace is hot gas, effectively reducing the loss of process atmosphere inside the furnace caused by the descent and opening of the bottom feeding mechanism 2, thus reducing operating costs. Specifically, in some embodiments, the bottom feeding mechanism 2 includes a platform for carrying the workpiece 3, a motor for driving the platform to rise and fall, and a guide rail for guiding the platform's rise and fall; wherein, the platform can be used to seal the feed inlet at the bottom of the feeding zone.

[0028] In one specific implementation, the top of the heating zone, strong carburizing zone, high-temperature diffusion zone, cooling diffusion zone, and heat preservation zone are all equipped with a gas supply mechanism 11 and a circulating fan mechanism 8. The gas supply mechanism 11 consists of nitrogen, carrier gas (Rs gas), process air, enriched gas (propane), safety nitrogen, and reference purging air for the oxygen probe. Each gas supply line is controlled by a flow meter, solenoid valve, and manual valve. Each zone has a separate air inlet pipe at the top of the furnace. The function of the gas supply mechanism 11 is to provide the process atmosphere for the workpiece 3 to carburize in the furnace. The circulating fan mechanism 8 includes a fan and a motor that drives the fan to rotate at high speed. The function of the circulating fan mechanism 8 is to ensure rapid circulation of the atmosphere in the furnace under high-temperature conditions and to ensure the uniformity of the atmosphere in the furnace.

[0029] Furthermore, the top of the heating zone, strong carburizing zone, high-temperature diffusion zone, cooling diffusion zone, and heat preservation zone is also equipped with a temperature carbon potential control mechanism 18. Each zone's temperature carbon potential control mechanism 18 consists of a separate oxygen probe, thermocouples, control instruments, etc. The oxygen probe detects the atmosphere inside the furnace and precisely controls the gas supply mechanism according to the process carbon potential requirements of each zone. Multiple thermocouples are set in each zone for process temperature and safety temperature control.

[0030] As an optimized implementation, the feeding area is equipped with a waste gas emission mechanism 15 for maintaining positive pressure inside the furnace. The waste gas emission mechanism 15 mainly includes a pressure holding valve and an ignition burner. The pressure holding valve has an adjustable counterweight, which is used to maintain the furnace pressure. The positive pressure inside the furnace is maintained by adjusting the counterweight. The pressure holding valve is a one-way structure and cannot be opened in the reverse direction, so that air cannot enter the furnace. At the same time, the ignition burner is used to ignite the combustion atmosphere inside the furnace and release the combustible atmosphere to meet the emission environmental protection requirements.

[0031] Regarding the internal structural design of the pusher section of the furnace body, in some embodiments, such as Figure 3The diagram shows a cross-sectional view of the pusher section and its isolation wall. The left side shows a cross-sectional view of the pusher section, and the right side shows a cross-sectional view of the isolation wall. The furnace shell 6 is an airtight, welded structure that provides overall sealing and external component support. An insulating lining 5, composed of fiber cotton and anti-carburizing bricks, is installed inside the shell 6 to ensure surface temperature rise, reduce heat loss, and lower energy consumption. The outer side is made of composite fiber cotton for better insulation, while the inner side is made of anti-carburizing bricks, providing both insulation and furnace support. A circulating fan mechanism 8 is installed on the furnace top to ensure uniform atmosphere in each zone. An inspection door 10 is installed on the side of the shell 6 for inspecting furnace problems. The inspection door 10 includes a sealed packing, a manually operated door with an insulation layer, and an observation window 21. The material tray slide 7 in the pusher section is located in the middle of the furnace body and is used to support the workpiece 3. The workpiece 3 moves one tray at a time in the material tray slide 7. The material tray slide 7 is made of high-quality silicon carbide and has good strength and wear resistance in high-temperature environments. Guide rails and guide bricks 19 are installed on both sides of the material tray slide 7 to guide the workpiece during the transfer process. Heating radiation tubes 20 are installed in the heating zone, strong carburizing zone, and high-temperature diffusion zone of the pusher section. The heating radiation tubes 20 are installed vertically on both sides of the furnace and are located between the guide rails and guide bricks 19 and the heat-insulating furnace lining 5, which together provide heating and heat preservation. The number of tubes in each zone is set according to process requirements. The function of the isolation wall 9 is to reduce the temperature transfer between the zones. The isolation wall 9 is constructed of anti-carburizing bricks with an opening in the middle, the size of which allows the workpiece 3 to pass through the isolation wall 9.

[0032] The structural design and layout of the roller drive mechanism are the same in each zone of the roller section. A detailed explanation will be given using the cooling and diffusion zone as an example. Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the roller drive mechanism includes several rollers 12 arranged side by side along the furnace body axis and a roller drive assembly 27 for driving the rollers 12 to rotate. The rollers 12 are arranged perpendicular to the furnace body axis and pass through the two side walls of the furnace body. The two ends of the rollers 12 are sealed to the furnace body through a sealed bearing assembly 26. The end of the roller 12 near the roller drive assembly 27 is fixed to the sealed bearing assembly 26. The end of the roller 12 away from the roller drive assembly 27 can slide relative to the sealed bearing assembly 26 after thermal expansion.

[0033] Specifically, multiple rollers 12 support the workpiece 3. The rollers 12 adopt an integral heat-resistant steel structure, with steel pipes in the middle and welded transmission rods at both ends. The outer sides are insulated with heat-insulating sleeves 23. Since the furnace contains a flammable atmosphere, air entering the furnace poses an explosion hazard at safe temperatures. Furthermore, the flammable atmosphere itself is a toxic and harmful gas, and leakage would not meet environmental protection requirements. Therefore, the roller 12 is supported and driven at both ends by sealed bearing assemblies 26, which employ a sealed design. The sealed bearing assemblies 26 on both sides of the roller 12 are slightly different. The end of the roller 12 closest to the roller drive assembly 27 is directly fixed to the roller 12 by the sealed bearing assembly 26, while the end of the roller 12 furthest from the roller drive assembly 27 slides within the sleeve of the sealed bearing assembly 26, ensuring that it does not bend under high-temperature conditions. Guide sleeves 24 are located on both sides of the workpiece position in the middle of the roller 12, welded to the roller 12 to ensure that the workpiece 3 on the roller 12 does not deviate from its position. During operation, the roller 12 needs to rotate continuously back and forth under high-temperature conditions, while the workpiece 2 swings back and forth on the roller 12 within the working area, preventing the roller 12 from bending under high temperature and pressure.

[0034] In some embodiments, such as Figure 5 As shown, this is a specific embodiment of the sealed bearing assembly at the sliding end of the roller. The sealed bearing assembly 26 adopts a multi-segment combined structure, which is pressed from the inside out to ensure the sealing of the carburizing furnace. Specifically, it includes a sliding sleeve 28, a sliding key 29, a sealing sleeve 30, a skeleton shaft seal 31, a bearing 32, a bearing sleeve 33, a connecting sleeve 34, and a roller support plate 36. Among them, the sliding sleeve 28 is a sealed steel pipe structure, and the sliding key 29 is fixed inside it. After the roller 12 expands at high temperature, it can slide on the sliding key 29. The rotation of the roller 12 is supported by the sliding sleeve 28 and rotates together with the sliding key 29. The sliding sleeve 28 rotates inside the bearing 32. The outside of the sliding sleeve 28 is sealed by the symmetrically installed skeleton shaft seal 31. The skeleton shaft seal 31 is installed inside the sealing sleeve 30, and the bearing 32 is installed inside the bearing sleeve 33. The upper part of the bearing sleeve 33 has an opening for connecting... A nitrogen pipeline 22 is connected to maintain positive pressure inside the sealed bearing assembly 26 by introducing a small flow of nitrogen, ensuring the isolation of the atmosphere inside and outside the furnace and achieving the sealing of the roller bearing. The connecting sleeve 34 is used to connect the roller support plate 36 and the bearing sleeve 33. The connecting sleeve 34 supports a graphite ring 35 inside and has polytetrafluoroethylene seals on both sides. The graphite ring 35 plays a certain role in isolating furnace gas and sealing. In this embodiment, the graphite ring 35 is the first layer of seal for the roller 12. The connecting sleeve 34 is connected to the roller support plate 36 outside the furnace shell 6 and externally connected to the bearing sleeve 33. The bearing 32 is installed inside the bearing sleeve 33. The external connecting sealing sleeve 30 has a skeleton shaft seal 31 inside to ensure the sealing of the rotating roller 12. At the same time, a small flow of nitrogen is opened at the top of the bearing sleeve 33 to introduce nitrogen to maintain positive pressure inside the sealed bearing, ensuring the isolation of the atmosphere inside and outside the furnace and achieving the sealing of the roller bearing.

[0035] In addition, the transmission section of the furnace shell roller section and the connection part of the roller are made of channel steel 37, which is used to connect the roller support plate 36. The roller support plate 36 is externally connected to a sealed bearing. The roller support plate 36 supports multiple rollers 12 at the same time. Roller support plate adjustment 43 is installed on the upper side of the four sides of the roller support plate 36, which can adjust the left and right height positions and thus adjust the level of the rollers 12 to ensure smooth transmission of the workpiece 3. Large holes are opened on the roller support plate 36 to allow the rollers 12 to be removed for replacement and maintenance.

[0036] like Figure 6 and Figure 7 As shown, this is a specific embodiment of the roller drive assembly 27. The roller drive assembly 27 includes a chain 39, a chain guide plate 42, and a drive motor 40 that drives the chain 39 to rotate along the chain guide plate 42. The chain guide plate 42 is arranged parallel to the furnace body axis. The drive ends of each roller 12 are rotatably connected to the chain 39 via sprockets 44. The chain guide plate 42 is supported by an adjusting support plate 41, which can adjust the level of the chain guide plate 42 and press the sprockets 44. The drive motor 40 drives the chain 39 to rotate along the chain guide plate 42, and the upper part of the chain 39 drives the sprockets 44 to rotate, thereby driving the rollers 12 to rotate. The two sides of the chain guide plate 42 are semi-circular, and the rollers on the chain 39 roll on the chain guide plate 42. Furthermore, a chain tensioning mechanism 38 for tensioning the chain 39 is provided between the drive motor 40 and the chain guide plate 42.

[0037] In one specific implementation, heating radiation pipes 20 for heating and heat preservation of the workpiece 3 and cooling pipes 25 for cooling the workpiece 3 are installed on both sides of the cooling diffusion zone. For the cooling process within the cooling diffusion zone, air cooling is used. In some embodiments, an exhaust cooling mechanism 17 is designed for cooling, such as... Figure 1 and 8As shown, the system specifically includes a variable frequency speed-regulating fan 50, an electric butterfly valve 49, and multiple sets of cooling pipes 25. The fan 50 is located outside the furnace body, and the multiple sets of cooling pipes 25 are installed in the cooling diffusion zone to cool the zone. The multiple sets of cooling pipes 25 are connected to the exhaust pipe of the fan 50, and the electric butterfly valve 49 is installed on the exhaust pipe. Specifically, the cooling pipe 25 includes an inner pipe 47 and an outer pipe 46. The upper part of the outer pipe 46 is provided with an air inlet 45, the lower part of the outer pipe 46 is connected to the bottom of the inner pipe 47, and the upper part of the inner pipe 47 is connected to the exhaust pipe through an air outlet 48. During cooling, the electric butterfly valve 49 opens, and the fan 50 starts. The fan 50 uses a suction method, creating negative pressure in the main exhaust pipe during cooling. Air is drawn out from the outlet 48 of the cooling pipe 25. The bottom of the inner pipe 47 is connected to the outer pipe 46, creating negative pressure in the outer pipe 46. Finally, cold air is automatically drawn in from the inlet 45. Heat in the furnace is exchanged through the inner and outer walls of the outer pipe 46. The heated air is then exhausted by the fan 50, completing the heat exchange process and cooling the cooling chamber. The cooling rate in the cooling diffusion zone is adjusted by the frequency converter to regulate the fan 50 speed and thus the air volume. A manual butterfly valve can also be installed at the inlet of the cooling pipe 25 to adjust the amount of cold air entering the chamber. The lower part of the outer tube 46 of the cooling tube 25 is under negative pressure, and cold air flows from top to bottom. The outer tube 46 exchanges heat with the furnace through the tube wall. During the cooling process, the air in the outer tube flows under negative pressure. When there is no cooling, the outer tube 46 is under zero pressure, and the furnace in the cooling diffusion zone is under positive pressure. Even if the cooling tube 25 is corroded under long-term high temperature and small cracks occur, the atmosphere in the furnace can only leak to the cooling tube 25, thus ensuring the safety of the furnace.

[0038] Preferably, the cooling diffusion zone is equipped with a material level detection mechanism 13 for detecting the movement position of the workpiece. The material level detection mechanism 13 includes an external furnace grating, a ball valve, a glass plate, and a detection steel pipe. The grating is a through-beam grating, which is installed outside the furnace and detects the position of the workpiece through the sealed glass. When the workpiece 3 passes through, a signal is sent to detect the material level. There are small flow nitrogen inlets on both sides of the detection steel pipe. The introduction of small flow nitrogen not only serves as a seal but also prevents carbon black from contacting the glass plate, ensuring the accuracy of position detection.

[0039] Specifically, the quenching zone is equipped with a quenching tank 14, which is installed outside the heat preservation zone. After the cycle time is reached, the intermediate isolation door 4 between the heat preservation zone and the quenching zone is opened, and the lifting platform driving rod of the quenching tank 14 and the carburizing furnace rod are driven simultaneously, so that the workpiece 3 is discharged for quenching.

[0040] Because carbon black will accumulate inside the continuous carburizing furnace after prolonged use, it needs to be cleaned regularly. Figure 2As shown, it is therefore preferable to provide a carbon black burning mechanism 16 on the furnace body for introducing air into each zone of the furnace body to burn carbon deposits inside the furnace; the carbon black burning mechanism is installed on the outside of the furnace body and consists of an air pump and a solenoid valve, with its branch pipes connected to the furnace chambers of each zone, which can periodically raise the furnace chamber temperature to above the safe temperature and introduce air to burn and eliminate carbon black inside the furnace.

[0041] In summary, the continuous heat treatment carburizing furnace combining pusher plate and roller bar provided by this utility model combines the advantages of pusher plate carburizing furnace production line and roller bar carburizing furnace production line. The overall layout adopts a straight-through form, with a pusher plate structure in the front section and a roller bar structure in the rear section, which occupies little space. At the same time, it has the characteristics of high output and energy saving of pusher plate furnace. It adopts multi-segment zone control, which has low energy consumption and low overall production cost.

[0042] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A continuous heat treatment carburizing furnace combining a pusher plate and rollers, comprising a furnace body, characterized in that: The furnace body includes a pusher plate section and a roller section arranged coaxially. The pusher plate section has a feeding zone, a heating zone, a strong carburizing zone, and a high-temperature diffusion zone arranged sequentially along its axis. The pusher plate section is provided with a material tray slide that runs through each zone of the pusher plate section. The feeding zone is provided with a push rod mechanism outside the material tray slide to move the workpiece. The roller section has a cooling diffusion zone, a heat preservation zone, and a quenching zone arranged sequentially along its axis. Each zone of the roller section is provided with a roller drive mechanism, and the roller drive mechanisms of adjacent zones are connected. The roller drive mechanism of the cooling diffusion zone is connected to the material tray slide of the high-temperature diffusion zone. Each pair of adjacent zones in the feeding zone, heating zone, strong carburizing zone, high-temperature diffusion zone, cooling diffusion zone, heat preservation zone, and quenching zone is isolated by an isolation structure.

2. The continuous heat treatment carburizing furnace combining pusher and roller as described in claim 1, characterized in that: The feeding zone and the heating zone, as well as the two adjacent zones of the roller section, are isolated by intermediate isolation doors. Isolation walls are provided between the heating zone and the strong carburizing zone, and between the strong carburizing zone and the high-temperature diffusion zone. The isolation walls have openings for the workpiece to pass through.

3. The continuous heat treatment carburizing furnace combining a pusher and rollers as described in claim 1, characterized in that: The bottom of the feeding area is provided with a feeding port, and the bottom of the feeding area is provided with a bottom feeding mechanism for lifting and feeding. The bottom feeding mechanism can be sealed and connected to the feeding port.

4. The continuous heat treatment carburizing furnace combining pusher and roller as described in claim 1, characterized in that: The cooling diffusion zone is equipped with heating radiation tubes for heating and keeping the workpiece warm, and cooling tubes for cooling the workpiece.

5. The continuous heat treatment carburizing furnace combining pusher and roller as described in claim 4, characterized in that: The cooling pipe includes an inner pipe and an outer pipe. An air inlet is provided at the upper part of the outer pipe. The lower end of the outer pipe is connected to the lower end of the inner pipe. The upper end of the inner pipe is connected to the exhaust pipe of the exhaust cooling mechanism located outside the cooling diffusion zone.

6. The continuous heat treatment carburizing furnace combining pusher and roller as described in claim 1, characterized in that: The roller drive mechanism includes several rollers arranged side by side along the furnace body axis and a roller drive assembly for driving the rollers to rotate. The rollers are arranged perpendicular to the furnace body axis and pass through both side walls of the furnace body. Both ends of the rollers are sealed to the furnace body through sealed bearing assemblies. The end of the roller closer to the roller drive assembly is fixed to the sealed bearing assembly, while the end of the roller away from the roller drive assembly is slidably connected to the sealed bearing assembly.

7. The continuous heat treatment carburizing furnace combining pusher and roller as described in claim 6, characterized in that: The roller drive assembly includes a chain, a chain guide plate, and a drive motor that drives the chain to rotate along the chain guide plate. The chain guide plate is arranged parallel to the furnace body axis, and the drive end of each roller is rotatably connected to the chain via a sprocket.

8. The continuous heat treatment carburizing furnace combining pusher and roller as described in claim 1, characterized in that: The top of the heating zone, strong carburizing zone, high-temperature diffusion zone, cooling diffusion zone, and insulation zone are all equipped with an air supply mechanism and a circulating fan mechanism.

9. The continuous heat treatment carburizing furnace combining a pusher and rollers as described in claim 1, characterized in that: The feeding area is equipped with a waste gas emission mechanism to maintain positive pressure inside the furnace.

10. The continuous heat treatment carburizing furnace combining pusher and roller as described in claim 1, characterized in that: The furnace body is equipped with a carbon black burning mechanism for introducing air into each zone of the furnace body to burn the carbon deposits inside the furnace.

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