Quenching and cooling chamber

Abstract

A quenching and rapid cooling chamber is provided, which has a furnace shell, a bracket is arranged in the furnace shell, and multiple workpieces are evenly placed on the bracket; air cooling devices and spray cooling devices are arranged above and below the bracket, and a non-contact water cooling heat exchange device is arranged in the furnace shell, and the air cooling device, spray cooling device, and non-contact water cooling heat exchange device are arbitrarily combined to cool the workpiece. The present invention adopts a cooling method of any combination of air cooling, spraying, and non-contact water cooling heat exchange, and realizes the industrialization and mass quenching and cooling production of large-size long-axis parts such as railway switch heart rails, and has the advantages of anti-deformation, high efficiency, more economical and practical, and stable and reliable quenching quality.

Description

Technical Field

[0001] The invention belongs to the technical field of quenching heat treatment equipment for metallurgical metal materials, and in particular relates to a quenching rapid cooling chamber. Background Art

[0002] Bainitic alloy steel has been widely used in locomotive bearings, switch heart rails and other applications that require high strength, high hardness and high toughness due to its excellent strength and toughness. The best heat treatment process for bainitic steel is isothermal heat treatment in a salt bath furnace, which can stably obtain the best performance. However, the larger size of the heart rail will greatly increase the process time required for salt bath treatment, resulting in low labor efficiency and increased production costs. Therefore, the isothermal treatment method in a salt bath furnace is only suitable for some small parts, and is not suitable for industrial mass production of large-sized long-axis parts such as railway switch heart rails.

[0003] At present, there is no dedicated quenching and rapid cooling equipment in the heat treatment technology of bainitic steel frog rails. The conventional practice is to heat the rail to austenitization, hang it out of the furnace or place it flat in an open indoor environment such as a bracket or a material pad, and use an axial flow fan to blow strong wind for continuous cooling. The adjustable range of cooling speed is small, and it is greatly affected by the ambient temperature, resulting in poor product quality consistency.

[0004] In the design of quenching cooling equipment that combines air cooling, water cooling and spray cooling, the spray cooling method has a large specific heat capacity of water. The workpiece is in direct contact with water during the quenching process, which will cause the surface of the workpiece to cool rapidly, causing the workpiece to inevitably produce heat treatment deformation problems such as distortion and lateral bending due to the large core-surface temperature difference. Straightening treatment is required, which invisibly increases the process, and the deformation amount is uncontrollable, and the product quality stability is poor. In this regard, the following improved technical solutions are proposed. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a quenching and rapid cooling chamber, which adopts a cooling method of any combination of air cooling, spraying, and non-contact water cooling heat exchange to solve the industrialized, large-scale, deformation-resistant, high-efficiency, and quality-stable quenching and cooling production technology problems of large-size long-axis parts such as railway switch heart rails.

[0006] The technical solution adopted by the present invention is as follows: a quenching and rapid cooling chamber comprises a furnace shell and a furnace door, a bracket is arranged in the furnace shell, and a plurality of workpieces are evenly placed on the bracket; an air cooling device and a spray cooling device are arranged above and below the bracket, and a non-contact water cooling heat exchange device is arranged in the furnace shell, and the air cooling device, the spray cooling device and the non-contact water cooling heat exchange device are arbitrarily combined to cool the workpieces on the bracket.

[0007] In the above technical scheme, further: the air cooling device has a centrifugal fan, which is a variable frequency centrifugal fan; the air inlet end of the centrifugal fan is connected to the cold air inlet pipe, and the cold air inlet pipe 32 is connected to the upper bellows and the lower bellows; the upper bellows air outlet is arranged directly above the bracket, and the air supply size of the upper bellows air outlet is greater than or equal to the bracket size; the lower bellows air outlet is arranged directly below the bracket, and the air supply size of the lower bellows air outlet is greater than or equal to the bracket size; the air outlet end of the centrifugal fan is connected to the exhaust pipe.

[0008] In the above technical scheme, further: the air cooling device has a four-way valve, one end of the four-way valve is connected to the cold air inlet pipe, and the other end of the four-way valve is connected to the air inlet end of the centrifugal fan; the other two ends of the four-way valve are respectively connected to the upper bellows and the lower bellows; a reversing valve plate is provided in the four-way valve, and before the reversing valve plate is reversed: the upper bellows and the lower bellows blow air from top to bottom for cooling; after the reversing valve plate is reversed, the upper bellows and the lower bellows blow air from bottom to top for cooling.

[0009] In the above technical solution, further: the reversing valve plate is a valve plate structure that rotates on a fixed axis in the valve cavity of the four-way valve; the reversing interval time of the reversing valve plate is set through a PLC controller.

[0010] In the above technical scheme, further: the upper air box and the lower air box are respectively provided with a plurality of partition air outlets of equal number, each partition air outlet is respectively provided with an independent air valve switch Ⅰ and air valve door Ⅰ; the air valve switch Ⅰ is controlled by a PLC controller to control the opening and closing time; the air valve door Ⅰ is controlled by a PLC controller to control the air volume.

[0011] In the above technical scheme, further: the air cooling device has a hot air inlet pipe; one end of the hot air inlet pipe is connected to the cold air inlet pipe; the other end of the hot air inlet pipe is connected to the exhaust pipe; the hot air inlet pipe is provided with an air valve switch II and an air valve valve II of the hot air inlet pipe.

[0012] In the above technical scheme, further: the non-contact water-cooled heat exchange device has a water-cooled heat exchange plate; the water-cooled heat exchange plate is a hollow thin plate cavity structure with circulating water passing through it; there are multiple water-cooled heat exchange plates, and the multiple water-cooled heat exchange plates are arranged at equal intervals in the horizontal direction, and the number of water-cooled heat exchange plates is N+1, where N is the number of workpieces to be processed; water-cooled heat exchange plates are provided on both sides of each workpiece.

[0013] In the above technical scheme, further: the water-cooled heat exchange device has a lifting mechanism, and the lifting end of the lifting mechanism is fixedly connected to the water-cooled heat exchange plate to drive the water-cooled heat exchange plate to lift and lower; the water-cooled heat exchange plate is suspended at the lower part of the upper spray cooling device in a non-working state; the lifting mechanism controls the lifting time of the water-cooled heat exchange plate and the holding time of the water-cooled heat exchange plate lifted or lowered into place through a PLC controller.

[0014] In the above technical scheme, further: a lifting furnace door is installed on the furnace shell; the furnace door is lifted and lowered by a furnace door lifting chain, and the chain engages with a sprocket transmission mechanism; the sprocket transmission mechanism is driven and operated by a drive motor; rollers are provided on both sides of the furnace door; guide rails are provided on both sides of the furnace shell; the rolling friction between the rollers and the guide rails is adapted to realize the vertical and linear lifting of the furnace door; the lifting furnace door is equipped with a furnace door lifting counterweight.

[0015] In the above technical scheme, further: the spray cooling device has a plurality of upper spray nozzles and a plurality of lower spray nozzles of equal number; the upper spray nozzle is arranged at the lower part of the air outlet of the upper air cooling device, and the lower spray nozzle is arranged between the lower air cooling device and the bracket; the upper spray nozzle and the lower spray nozzle are opposite to each other up and down and are evenly distributed with equal intervals in the horizontal direction; each spray nozzle is respectively provided with a solenoid valve, and each spray nozzle is a pulse spray nozzle, and the pulse spray nozzle supplies cold air to the nozzle by connecting the mist nozzle air cooling pipe, and the cold air is mixed with the water vapor in the spray water supply pipe of the spray nozzle to realize pulse spraying, and the mist nozzle air cooling pipe is provided with a mist nozzle air cooling valve; the PLC controller controls the upper spray nozzle and the lower spray nozzle to alternately pulse spray or simultaneously pulse spray; the PLC controller controls the opening time and opening duration of the pulse spray of the upper spray nozzle and the lower spray nozzle.

[0016] The advantages of the present invention compared with the prior art are:

[0017] 1. The non-contact water cooling heat exchange technology of the present invention utilizes the rapid heat exchange capacity of circulating water and adopts a non-contact water cooling heat exchange device to absorb the radiant heat of the workpiece, thereby meeting the quenching cooling rate requirements of the workpiece. Compared with the contact water cooling technology, it can effectively avoid the occurrence of heat treatment deformation problems caused by excessive core-surface temperature difference in the workpiece, and has the characteristics of stable process, simple operation, small deformation, good quality, etc.

[0018] 2. The air cooling device of the present invention adopts an upper and lower reversing cooling method. Compared with the non-reversing air cooling method, it can ensure that the upper and lower surfaces of the workpiece can be cooled at a relatively uniform cooling rate, avoiding the occurrence of workpiece deformation problems caused by excessive differences in cooling rates between the upper and lower surfaces.

[0019] 3. The present invention adopts a pulse spray cooling device connected to an air source, which can effectively reduce the temperature difference between the core and the surface of the workpiece, and at the same time reduce the heat treatment deformation, make the cross-sectional performance indicators of the workpiece after heat treatment more uniform.

[0020] 4. The present invention adopts a combination of three cooling methods, namely heat exchange, air cooling and spraying, to meet the cooling rate requirements of bainitic frog steel at different stages of high temperature, medium temperature and low temperature during the quenching process, and realizes the diversification of cooling rate adjustment methods. Different forms of bainitic structures (lath / granular) can be obtained by process means, and finally different mechanical performance indicators can be obtained; a wide range of adjustment of different cooling rates during the quenching cooling of workpieces such as bainitic alloy steel frog heart rails and wing rail inserts can be achieved; for example, by combining air cooling + non-contact cooling water to absorb the radiation heat of the frog heart rail, the cooling rate of the bainitic steel frog heart rail in the high temperature stage is increased, and the generation of proeutectoid ferrite in the frog heart rail during the structural transformation process is avoided; the combination of air cooling + spraying increases the cooling rate adjustment range of the bainitic frog heart rail in the medium temperature stage of quenching cooling, and different forms of bainitic structures (lath / granular) can be obtained by process means, so that different mechanical performance indicators can be finally obtained.

[0021] 5. The present invention sets different wind speeds in the left, middle and right zones along the length direction of the frog heart rail according to different thickness sections, thereby achieving uniform cooling at different sections of the bainite steel frog heart rail; thereby ensuring that the organizational morphology and mechanical performance indicators within the entire length of the frog heart rail are more balanced; solving the problem of large temperature differences in different sections during air cooling and rapid cooling, avoiding performance differences in heat treatment at different positions, and achieving that the heart rail at different zones can complete the quenching cooling process at a relatively uniform cooling rate, thereby obtaining products with excellent performance consistency at different parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a front perspective view of the working principle of air cooling, spraying and heat exchange cooling of the present invention;

[0023] Figure 2 A side perspective view of the working principle of the present invention when air supply cooling and heat exchange cooling are used in combination from top to bottom;

[0024] Figure 3 It is a top perspective view of the principle of the four-way valve reversing air supply in the air cooling device of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the furnace door lifting principle of the present invention;

[0026] Figure 5 for Figure 2 A schematic diagram of the enlarged details of the non-contact water-cooled heat exchange device when the water-cooled heat exchange plate is lowered into place;

[0027] Figure 6 This is a working principle diagram of the pneumatic system of the present invention;

[0028] Figure 7 This is a working principle diagram of the pulse spray cooling of the present invention;

[0029] Figure 8 A control circuit diagram of an embodiment of three cooling methods of the present invention;

[0030] Fig. 9 The frequency conversion control circuit diagram of the centrifugal fan of the air cooling device of the present invention;

[0031] Fig.10 This is a control circuit diagram of a four-way valve of an air cooling device of the present invention;

[0032] Fig.11 It is a control circuit diagram of a zoned air outlet air valve switch Ⅰ and an air valve valve Ⅰ in an embodiment of the air cooling device of the present invention;

[0033] Fig.12 The invention is an embodiment of the partitioned air outlet of the air cooling device when the workpiece is a frog rail.

[0034] In the figure: 1-furnace shell, 2-bracket, 3-air cooling device, 4-spray cooling device, 5-non-contact water cooling heat exchange device; 31-centrifugal fan, 32-cold air inlet pipe, 33-upper bellows, 34-lower bellows, 35-exhaust pipe, 36-four-way valve, 361-reversing valve plate; 331-partitioned air outlet, 37-hot air inlet pipe; 51-water cooling heat exchange plate; 61-chain, 62-sprocket transmission mechanism, 63 -drive motor, 64-furnace door lifting counterweight, 65-roller, 66-guide rail; 41-upper spray nozzle, 42-lower spray nozzle, 43-water tank, 431-water level perspective window, 44-tap water pipeline valve, 45-overflow valve, 46-drain valve, 47-mist nozzle air cooling pipeline, 48-spray water supply pipeline; 7-manifold, 8-four-way valve cylinder, 9-water cooling plate cylinder, 10-pulse spray mist nozzle air cooling valve. DETAILED DESCRIPTION

[0035] The following will be combined with the attached embodiment of the present invention Figure 1-11 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] (like Figure 1 Figure 4 The quenching and rapid cooling chamber (as shown) comprises a furnace shell 1 and a furnace door 6. A bracket 2 is arranged in the furnace shell 1, and a plurality of workpieces are evenly placed in the bracket 2.

[0037] The bracket 2 is made of multiple evenly spaced and parallel I-beams, the length direction of the multiple I-beams is perpendicular to the length direction of the workpieces to be quenched, and the multiple I-beam brackets 2 share the load and place multiple evenly spaced and parallel workpieces to be quenched.

[0038] Air cooling devices 3 and spray cooling devices 4 are provided above and below the support 2, and a non-contact water cooling heat exchange device 5 (such as Figure 2 The air cooling device 3, the spray cooling device 4, and the non-contact water cooling heat exchange device 5 are randomly combined to cool the workpiece on the bracket 2.

[0039] The present invention adopts any combination of three cooling methods, namely heat exchange, air cooling and spraying, to carry out combined cooling to meet the cooling rate requirements of bainite frog steel at different stages of high temperature, medium temperature and low temperature during the quenching process, thereby realizing the diversification of cooling rate adjustment methods.

[0040] Different forms of bainite structures (lath-like / granular) can be obtained through process control, and ultimately different mechanical performance indicators can be obtained, realizing wide adjustment of different cooling rates during quenching cooling of workpieces such as bainite alloy steel frog heart rails and wing rail inserts.

[0041] In the above embodiment, further: the air cooling device 3 has a centrifugal fan 31, and the centrifugal fan 31 is a variable frequency centrifugal fan; the use of a variable frequency centrifugal fan has the effect of energy saving and consumption reduction.

[0042] The air inlet end of the centrifugal fan 31 is connected to the cold air inlet pipe 32, and the cold air inlet pipe 32 is connected to the upper air box 33 and the lower air box 34. The upper and lower air supply cooling is uniform.

[0043] The air outlet of the upper bellows 33 is arranged directly above the bracket 2, and the air supply size of the upper bellows 33 is greater than or equal to the size of the bracket 2; the air outlet of the lower bellows 34 is arranged directly below the bracket 2, and the air supply size of the lower bellows 34 is greater than or equal to the size of the bracket 2, so as to achieve air supply cooling covering all workpieces.

[0044] The air outlet of the centrifugal fan 31 is connected to the exhaust pipe 35 to establish a cold air circulation.

[0045] (like Figure 3 In the above embodiment, further: the air cooling device 3 has a four-way valve 36, one end of the four-way valve 36 is connected to the cold air inlet pipe 32, and the other end of the four-way valve 36 is connected to the air inlet end of the centrifugal fan 31; the other two ends of the four-way valve 36 are respectively connected to the upper bellows 33 and the lower bellows 34. A reversing valve plate 361 is arranged inside the four-way valve 36. Before the reversing valve plate 361 is reversing, the upper bellows 33 and the lower bellows 34 blow air from top to bottom for cooling; after the reversing valve plate 361 is reversing, the upper bellows 33 and the lower bellows 34 blow air from bottom to top for cooling.

[0046] The air cooling device of the present invention realizes the upper and lower reversing cooling method through the four-way valve 36 and the reversing valve plate 361. Compared with the non-reversing air cooling method, it can ensure that the upper and lower surfaces of the workpiece can be cooled at a relatively uniform cooling rate, avoiding the problem of excessive difference in surface hardness of the workpiece caused by excessive difference in cooling rate between the upper and lower surfaces. At the same time, the upper and lower reversing air cooling realizes the uniform cooling of the upper and lower surfaces of the heart rail during the whole process of quenching and cooling of the bainite steel frog heart rail and can effectively reduce the deformation of the upper and lower heart rails.

[0047] In the above embodiment, further: the reversing valve plate 361 is a valve plate structure that rotates on a fixed axis in the valve cavity of the four-way valve 36; the reversing interval time of the reversing valve plate 361 is set by a PLC controller.

[0048] Specifically, the reversing valve plate 361 is Figure 6 The four-way valve cylinder 8 shown pushes the reversing valve plate 361 to rotate in the cavity of the four-way valve 36 to achieve reversing air supply.

[0049] In the above embodiment, further: the upper air box 33 and the lower air box 34 are respectively provided with a plurality of equal number of partition air outlets 331, and each partition air outlet 331 is respectively provided with an independent air valve switch Ⅰ and an air valve door Ⅰ; the air valve switch Ⅰ is controlled by a PLC controller to control the opening and closing time; the air valve door Ⅰ is controlled by a PLC controller to control the air volume.

[0050] Specifically: During the entire quenching cooling process, different wind speeds are set in three zones along the length direction of the frog rail according to different thickness sections. During the entire cooling process, the cooling speed is set according to the temperature difference of different sections to solve the problem of large temperature difference of different sections during the rapid cooling process. In the height direction of the frog rail, the upper and lower reversing air blowing cooling method is adopted to achieve uniform cooling of the upper and lower surfaces of the frog rail.

[0051] The purpose of zoned cooling is that the widths of different sections along the length direction are different. If there is no zone, the overall uniform blowing and cooling will inevitably lead to different heat and cooling rates due to size differences in different sections, which will lead to differences in performance after the final heat treatment. The present invention is to divide the quick cooling room into multiple zones along the length direction of the core rail. At the beginning of quick cooling, multiple zone air valve switches I are all opened to supply air. When the cooling rate difference of the core rail surface in different zones reaches the process setting value, the air valve switch I of the zone with a larger cooling rate is closed for a short time and then opened again to perform pulse blowing, so that the parts of the core rail in different zones can complete the quenching cooling process at a relatively uniform cooling rate.

[0052] Therefore, the present invention sets different wind speeds in different zones according to different thickness sections along the length direction of the frog heart rail, solves the problem of large temperature difference in different sections during air cooling, avoids performance differences in heat treatment at different positions, and enables the heart rail in different zones to complete the quenching cooling process at a relatively uniform cooling rate, thereby obtaining products with excellent performance consistency at different positions.

[0053] In the above embodiment, further: the air cooling device 3 has a hot air inlet pipe 37; one end of the hot air inlet pipe 37 is connected to the cold air inlet pipe 32; the other end of the hot air inlet pipe 37 is connected to the exhaust pipe 35; the hot air inlet pipe 37 is provided with an air valve switch II and an air valve valve II of the hot air inlet pipe 37.

[0054] In the working state, when the air valve switch II of the hot air inlet pipe 37 is closed, no air flow enters the hot air inlet pipe 37. When the air valve switch II is opened, due to the negative pressure of the cold air inlet pipe 32, the hot air is introduced into the cold air inlet pipe 32 through the hot air inlet pipe 37 from the exhaust pipe 35, thereby introducing the hot air into the quick cooling chamber, so as to achieve the purpose of increasing the air temperature when necessary.

[0055] This technical solution connects the exhaust pipe 35 via the hot air inlet pipe 37 to provide a temperature rise for the hot air in the exhaust pipe for air cooling, thereby eliminating the need for a special heating device and having the advantages of being economical and energy-saving.

[0056] (like Figure 2 , Figure 5 As shown in the above embodiment, further: the non-contact water-cooled heat exchange device 5 has a water-cooled heat exchange plate 51; the water-cooled heat exchange plate 51 is a hollow thin plate cavity structure with circulating water passing through the interior; specifically, the cavity can be an inverted U-shaped structure.

[0057] There are multiple water-cooled heat exchange plates 51, which are arranged at equal intervals in the horizontal direction. The number of water-cooled heat exchange plates 51 is N+1, and N is the number of workpieces to be processed; water-cooled heat exchange plates 51 are provided on both sides of each workpiece, so that each workpiece has water-cooled heat exchange plates 51 on both sides, ensuring that the cooling speed on both sides of the workpiece is basically the same, which can reduce the left and right deformation of the workpiece.

[0058] In the above embodiment, further: the water-cooled heat exchange device 5 has a lifting mechanism, and the lifting end of the lifting mechanism is fixedly connected to the water-cooled heat exchange plate 51 to drive the water-cooled heat exchange plate 51 to rise and fall; the water-cooled heat exchange plate 51 is suspended at the lower part of the upper spray cooling device 4 in a non-working state.

[0059] In addition: (see Figure 7 ) The water-cooled heat exchange device 5 also has a water tank 43, the water supply pipe of the water tank is connected to the municipal tap water pipeline for water supply, and the tap water pipeline is provided with a tap water pipeline valve 44.

[0060] A water level perspective window 431 is provided in the middle of the water tank 43, and the water level perspective window 431 is used to monitor in real time whether the water level is appropriate.

[0061] The water tank 43 is connected to an overflow pipe, and an overflow valve 45 is installed on the overflow pipe. A sewage pipe is provided at the bottom of the water tank 43, and a sewage valve 46 is provided in the sewage pipe. The sewage valve is used for discharging sediment.

[0062] The water outlet of the water tank 43 is provided with a spray water supply pipe 48, which is connected to a mist nozzle air cooling pipe 47; the mist nozzle air cooling pipe 47 is provided with Figure 6 The pulse spray nozzle air cooling valve 10 is shown. After the pulse spray nozzle air cooling valve 10 is opened, a pulse air flow is supplied to the spray cooling device.

[0063] It should be noted that the air supply principle of the mist nozzle air cooling pipe 47 can be found in Figure 6 : The mist nozzle air cooling pipe 47 is connected to the compressed air source, the compressed air source is distributed through the manifold 7, and the manifold 7 is connected to the four-way valve cylinder 8 through the pipe connected to its distribution hole, which drives the four-way valve cylinder 8 to switch the direction of the valve plate and change the air supply direction.

[0064] Another distribution hole of the manifold 7 is connected to the water-cooled plate cylinder 9 through a pipeline, and the water-cooled plate cylinder 9 is driven to move up and down by non-contact water cooling.

[0065] When the water-cooled heat exchange device 5 is in working state, such as falling from top to bottom in the high temperature stage (920°C-650°C temperature range) of rapid cooling of bainite alloy steel workpieces, the cooling water circulating inside absorbs the radiant heat of two adjacent workpieces.

[0066] The lifting mechanism of the water-cooled heat exchange plate 51 controls the lifting time of the water-cooled heat exchange plate 51 and the holding time of the water-cooled heat exchange plate 51 being lifted or lowered into place through a PLC controller.

[0067] The lifting and lowering of the water-cooled heat exchange plate 51 can be achieved by the action of a pneumatic cylinder or an oil cylinder.

[0068] Specifically, (such as Figure 6 As shown in the figure, the water-cooled heat exchange plate 51 is driven to rise and fall by the action of the water-cooled plate cylinder 9.

[0069] The non-contact water cooling heat exchange technology of the present invention utilizes the rapid heat exchange capacity of circulating water and adopts a non-contact water cooling heat exchange device to absorb the radiant heat of the workpiece, which meets the requirements of the quenching cooling rate of the workpiece. Compared with the contact water cooling technology, it can effectively avoid the problem of heat treatment deformation of the workpiece due to excessive core-surface temperature difference. It has the characteristics of stable process, simple operation, small deformation, good quality, etc.

[0070] (like Figure 4In the above embodiment, further: the furnace shell 1 is provided with a lifting furnace door 6; the furnace door 6 is lifted and lowered by a furnace door lifting chain 61.

[0071] It adopts chain drive to lift, the lifting height meets the requirements, the transmission is stable and the docking is convenient.

[0072] The chain 61 meshes with the sprocket transmission mechanism 62; the sprocket transmission mechanism 62 is driven by the driving motor 63; the driving motor 63 is a reduction motor, the power output shaft of the reduction motor drives the driving sprocket to rotate, the driving sprocket meshes with the chain, and the sprocket transmission mechanism also includes a driven sprocket and a guide sprocket. The driven sprocket and the guide sprocket mesh with the chain, and the two sides of the top of the lifting door body are vertically lifted and lowered synchronously with the chain.

[0073] In addition, rollers 65 are provided on both sides of the furnace door 6 ; guide rails 66 are provided on both sides of the furnace shell 1 ; the rollers 65 and the guide rails 66 are adapted to roll and frictionally fit to realize the vertical and linear lifting of the furnace door 6 .

[0074] The furnace door 6 that is lifted and lowered is equipped with a furnace door lifting counterweight 64. The furnace door lifting counterweight 64 is used for the balanced lifting and lifting of the furnace door to avoid the occurrence of the problem of rapid drop.

[0075] In the above embodiment, further: the spray cooling device 4 has a plurality of upper spray nozzles 41 and a plurality of lower spray nozzles 42 of equal number; the upper and lower sprays are evenly cooled.

[0076] The upper spray nozzle 41 is arranged at the lower part of the air outlet of the upper air cooling device 3 and is not blocked. The lower spray nozzle 42 is arranged between the lower air cooling device 3 and the bracket 2 and is not blocked.

[0077] The upper spray nozzle 41 and the lower spray nozzle 42 are opposite to each other and are evenly distributed in the horizontal direction at equal intervals to evenly reduce the temperature.

[0078] Each spray nozzle is provided with a solenoid valve to control the spray interval, such as three intervals, five intervals, four intervals or other multiple intervals.

[0079] And each spray nozzle is a pulse spray nozzle, which can cool down quickly and efficiently.

[0080] The pulse spray nozzle is connected to the mist nozzle air cooling pipe 47 to supply cold air to the nozzle, and the cold air is mixed with the water vapor in the spray water supply pipe 48 of the spray nozzle to achieve pulse spraying. The pulse structure is homemade and economical and practical.

[0081] The mist nozzle air cooling pipe 47 is provided with a mist nozzle air cooling valve 10, and the mist nozzle air cooling valve 10 can adjust whether to perform pulse spraying and can be used as needed.

[0082] The PLC controller controls the upper spray nozzle 41 and the lower spray nozzle 42 to perform pulse spraying alternately or simultaneously; the PLC controller controls the opening time and opening duration of the pulse spraying of the upper spray nozzle 41 and the lower spray nozzle 42.

[0083] The present invention adopts a pulse spray cooling device connected to an air source, which can effectively reduce the temperature difference between the core and the surface of the workpiece, and at the same time reduce the heat treatment deformation, make the cross-sectional performance index of the workpiece after heat treatment more uniform.

[0084] The working principle of the present invention is as follows: the furnace door of the rapid cooling chamber is opened - the material taking machine places the workpieces that need rapid cooling and are placed at a fixed interval on the bracket - the furnace door is closed - manual clicking starts the rapid cooling program - the machine automatically stops after the rapid cooling is completed.

[0085] The parameters that can be set in the rapid cooling program include the speed of the centrifugal fan and its duration; the opening time and duration of the upper and lower spray nozzles; the reversing time interval of the valve plate in the four-way valve; the closing or opening time and duration of the five partitions in the upper and lower bellows; and the falling time and duration of the water-cooled heat exchange plate.

[0086] The three systems of air cooling, water cooling heat exchange and spray in the rapid cooling room are controlled in a time closed loop in the industrial computer. They can work separately or in any combination at different stages of quenching and cooling, realizing a wide range of adjustment of different cooling speeds during the quenching and cooling of the bainitic alloy steel core rail.

[0087] Rapid cooling program, such as Fig.12 Take the quenching and cooling of the six frog rails shown as an example:

[0088] High temperature stage (920-650℃): The six frog rails use air cooling + non-contact water cooling heat exchange to absorb the radiation heat of the frog rails during the high temperature stage of quenching cooling.

[0089] The cooling rate of the bainite steel frog rail at a high temperature stage is increased by combining air cooling with non-contact cooling water to absorb the radiant heat of the frog rail, thereby avoiding the generation of proeutectoid ferrite during the structural transformation of the frog rail.

[0090] Medium temperature stage (650-450℃): Six frog rails are cooled by air cooling and spraying in the medium temperature stage of quenching. Pulse-type uniform spraying is applied to the upper and lower surfaces of the rails to achieve wide adjustment of the cooling speed in this temperature zone.

[0091] The combined use of air cooling and spraying improves the cooling rate adjustment range of the bainite frog rail in the medium temperature stage of quenching cooling, and can control different forms of bainite structures (lath / granular) through process means, so that different mechanical performance indicators can be finally obtained.

[0092] Taking the heat treatment process of the 60-12 frog rail as an example, in this temperature range, when a single air cooling method is used, the cooling rate of the rail surface can be controlled between 4-7°C per minute by adjusting the speed of the centrifugal fan. When a single spray method is used, the cooling rate of the rail surface can be controlled between 8-15°C per minute by adjusting the spray duration. If a combination of air cooling and spraying is used, the cooling rate can be controlled between 8-18°C. In summary, through different combinations and adjustments of the three methods, the cooling rate of the rail surface in this temperature range can be controlled within the range of 4-18°C / minute.

[0093] Low temperature stage (450-200℃): Six frog heart rails are cooled by upper and lower reversing air cooling in the low temperature stage of quenching cooling. By adjusting the air volume, frog heart rails with the same composition can obtain different mechanical performance indicators. For example, when the centrifugal fan continuously supplies air at a speed of 1100 rpm until the heart rail surface temperature drops to 200℃, the surface hardness of the final product can reach HRC45 or above. When the centrifugal fan stops blowing the heart rail surface temperature to 300℃, the surface hardness of the product is HRC40-42.5.

[0094] Air cooling, non-contact water cooling radiation heat exchange and spraying are three ways. They are controlled in a time closed loop in the PLC controller industrial computer. They work alone or in any combination at different stages of quenching and cooling to achieve wide adjustment of different cooling speeds during the quenching and cooling of workpieces such as bainitic alloy steel frog heart rails and wing rail inserts.

[0095] From the above description, it can be found that the present invention adopts a cooling method of any combination of air cooling, spraying, and non-contact water cooling heat exchange to achieve industrialized, large-scale, deformation-resistant, high-efficiency, stable-quality, economical and practical quenching and cooling production of large-size long-axis parts such as railway switch heart rails.

[0096] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A quenching and rapid cooling chamber, comprising a furnace shell (1) and a furnace door (6), characterized in that: A support (2) is provided in the furnace shell (1), and a plurality of workpieces are evenly placed in the support (2); an air cooling device (3) and a spray cooling device (4) are provided above and below the support (2); a non-contact water cooling heat exchange device (5) is provided in the furnace shell (1); the air cooling device (3), the spray cooling device (4), and the non-contact water cooling heat exchange device (5) are arbitrarily combined to cool the workpieces on the support (2); The air cooling device (3) comprises a centrifugal fan (31), which is a variable frequency centrifugal fan; the air inlet end of the centrifugal fan (31) is connected to a cold air inlet pipe (32), and the cold air inlet pipe (32) is connected to an upper bellows (33) and a lower bellows (34); the air outlet of the upper bellows (33) is arranged directly above the bracket (2), and the air supply size of the air outlet of the upper bellows (33) is greater than or equal to the size of the bracket (2); the air outlet of the lower bellows (34) is arranged directly below the bracket (2), and the air supply size of the air outlet of the lower bellows (34) is greater than or equal to the size of the bracket (2); the air outlet end of the centrifugal fan (31) is connected to an exhaust pipe (35); The air cooling device (3) comprises a four-way valve (36), one end of which is connected to the cold air inlet pipe (32), and the other end of which is connected to the air inlet end of the centrifugal fan (31); the other two ends of the four-way valve (36) are respectively connected to the upper bellows (33) and the lower bellows (34); a reversing valve plate (361) is arranged inside the four-way valve (36); before the reversing valve plate (361) is reversed, the upper bellows (33) and the lower bellows (34) blow air from top to bottom for cooling; after the reversing valve plate (361) is reversed, the upper bellows (33) and the lower bellows (34) blow air from bottom to top for cooling; The reversing valve plate (361) is a valve plate structure that rotates on a fixed axis in the valve cavity of the four-way valve (36); the reversing interval time of the reversing valve plate (361) is set by a PLC controller; The upper wind box (33) and the lower wind box (34) are respectively provided with a plurality of equal number of partitioned air outlets (331), and each partitioned air outlet (331) is respectively provided with an independent air valve switch I and an air valve door I; the opening and closing time of the air valve switch I is controlled by a PLC controller; and the air volume of the air valve door I is controlled by a PLC controller; The air cooling device (3) has a hot air introduction pipe (37); one end of the hot air introduction pipe (37) is connected to the cold air intake pipe (32); the other end of the hot air introduction pipe (37) is connected to the exhaust pipe (35); the hot air introduction pipe (37) is provided with an air valve switch II and an air valve valve II of the hot air introduction pipe (37); The non-contact water-cooled heat exchange device (5) comprises a water-cooled heat exchange plate (51); the water-cooled heat exchange plate (51) is a hollow thin plate cavity structure with circulating water inside; there are a plurality of water-cooled heat exchange plates (51), the plurality of water-cooled heat exchange plates (51) are arranged at equal intervals in the horizontal direction, the number of water-cooled heat exchange plates (51) is N+1, and N is the number of workpieces to be processed; a water-cooled heat exchange plate (51) is arranged on both sides of each workpiece; The non-contact water-cooled heat exchange device (5) has a lifting mechanism, and the lifting end of the lifting mechanism is fixedly connected to the water-cooled heat exchange plate (51) to drive the water-cooled heat exchange plate (51) to lift and lower; the water-cooled heat exchange plate (51) is suspended at the lower part of the spray cooling device (4) above in a non-working state; the lifting mechanism controls the lifting time of the water-cooled heat exchange plate (51) and the holding time of the water-cooled heat exchange plate (51) being lifted or lowered into place through a PLC controller; The spray cooling device (4) comprises a plurality of upper spray nozzles (41) and a plurality of lower spray nozzles (42) of equal number; the upper spray nozzles (41) are arranged at the lower part of the air outlet of the upper air cooling device (3), and the lower spray nozzles (42) are arranged between the lower air cooling device (3) and the bracket (2); the upper spray nozzles (41) and the lower spray nozzles (42) are opposite to each other in the vertical direction and are evenly distributed at equal intervals in the horizontal direction; each spray nozzle is respectively provided with a solenoid valve, and each spray nozzle is a pulse spray nozzle, and the pulse The pulse spray nozzle is connected to a mist nozzle air cooling pipe (47) to supply cold air to the nozzle, and the cold air is mixed with water vapor in a spray water supply pipe (48) of the spray nozzle to achieve pulse spraying, wherein the mist nozzle air cooling pipe (47) is provided with a mist nozzle air cooling valve (10); the PLC controller controls the upper spray nozzle (41) and the lower spray nozzle (42) to perform pulse spraying alternately or simultaneously; the PLC controller controls the opening time and opening duration of the pulse spraying of the upper spray nozzle (41) and the lower spray nozzle (42).

2. The quenching and rapid cooling chamber according to claim 1, characterized in that: The furnace shell (1) is provided with a lifting furnace door (6); the furnace door (6) is lifted and lowered by a furnace door lifting chain (61), the chain (61) is engaged with a sprocket transmission mechanism (62); the sprocket transmission mechanism (62) is driven and operated by a driving motor (63); rollers (65) are provided on both sides of the furnace door (6); guide rails (66) are provided on both sides of the furnace shell (1); the rollers (65) and the guide rails (66) are adapted to roll and frictionally engage with each other to realize vertical and linear lifting of the furnace door (6); the lifting furnace door (6) is provided with a furnace door lifting counterweight (64).

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