A quenching device for processing a stepped drill and a quenching method thereof

Abstract

This invention relates to the field of stepped drill machining technology, and provides a quenching device and method for machining stepped drills, including a furnace body with a nitrogen inlet pipe fixed to one side of the bottom of the furnace body. The invention incorporates a cooling structure, allowing high-pressure nitrogen to enter the bottom of the furnace body via the nitrogen inlet pipe. A negative pressure fan is activated to circulate and cool the nitrogen. When hot nitrogen is drawn into the frame, it is cooled to cold nitrogen by the cooling pipe. The cold nitrogen then enters the interior of the air hood through a circulating duct, and is then evenly sprayed onto the rotating stepped drill through a perforated guide plate. The perforated guide plate ensures uniform airflow. When the drive motor rotates the drive gear, the drive gear drives the rotating shaft through the driven gear, causing the rotating shaft to rotate the turntable and graphite support plate. The graphite support plate rotates the workpiece through the placement groove, ensuring that the stepped drill is cooled evenly from all directions during the cooling process, reducing bending and torsional deformation.

Description

Technical Field

[0001] This invention relates to the field of stepped drill machining technology, and in particular to a quenching device and quenching method for machining stepped drills. Background Technology

[0002] A step drill is a special cutting tool used to machine stepped holes. Its characteristic is that the cutting part has a stepped structure with multiple different diameters. One drill bit can replace multiple drill bits. In the process of machining step drills, in order to improve the hardness, wear resistance and service life of the step drill, it is necessary to heat treat and quench the step drill. Therefore, a quenching device for machining step drills is used. To this end, patent CN118910387A discloses a quenching device and its usage method for drill bit processing, including a quenching table, a frame, and a mechanical gripper. The frame is fixedly connected to the top of the quenching table, and the mechanical gripper is installed on the outer wall of the frame. A cooling component is installed on the front of the quenching table. The cooling component consists of a cooling box, a separation unit, a cooling unit, and a flow unit. The cooling box is fixedly connected to the front of the quenching table, and the separation unit and cooling unit are located inside the cooling box. This quenching device and its usage method for drill bit processing, by setting up a guide ring, a separation net, and a collection bin, allows the liquid on the drill bit surface to flow through the separation net and guide ring into the collection bin after the quenched drill bit falls onto the top of the separation net, thus collecting the liquid. After a certain amount of liquid has been collected, the collection bin can be pulled out by sliding to recover the liquid. Although the quenching device and its usage method for drill bit processing described above allow the liquid on the drill bit surface to flow through the separation net and guide ring into the interior of the accumulation chamber to complete the collection of liquid, and after a certain amount of liquid has been collected, the accumulation chamber can be pulled out by sliding to recover the liquid, this device is not suitable for uniform cooling. If the cooling is uneven during the quenching process of the stepped drill bit, the temperature gradient difference between different parts will be large, which will lead to thermal stress concentration, and thus cause deformation or cracking, making it unsuitable for use. Summary of the Invention

[0003] The purpose of this invention is to provide a quenching device and quenching method for machining stepped drills, so as to solve the defect of existing quenching devices for machining stepped drills that are inconvenient to cool evenly.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a quenching device for processing stepped drills, comprising a furnace body; A nitrogen inlet pipe is fixed to one side of the bottom of the furnace body, a support frame is fixed inside the furnace body, a heating structure is fixed to the top of the support frame, a furnace door is provided at one end of the bottom of the furnace body, and a sealing structure is fixed to one side of the furnace body. A cooling structure is fixed to the bottom of the furnace body. The cooling structure includes a first electric push rod fixed to the bottom of the furnace body. A fixed shell is fixed to the top of the first electric push rod. A drive gear is provided on one side inside the fixed shell. A driven gear is meshed with one side of the drive gear. A rotating shaft passes through the inside of the driven gear. The top of the rotating shaft extends to the outside of the fixed shell and is fixed with a turntable. Frames pass through both sides of the furnace body. A fan hood passes through the inside of the furnace body above the frame. A perforated guide plate is fixed inside the fan hood. A negative pressure fan is fixed inside the frame. A cooling pipe is fixed inside the frame on one side of the negative pressure fan. A circulating air duct is evenly fixed on one side of the fan hood. A graphite support plate is fixed to the top of the cooling structure, and the top of the graphite support plate is uniformly provided with placement grooves.

[0005] Preferably, a drive motor is installed at the bottom of the fixed housing below the drive gear, a connecting plate is fixed on one side of the fixed housing, and a fixing rod passes through the interior of the connecting plate.

[0006] Preferably, one end of the cooling pipe extends to the outside of the frame and is fixed with an inlet pipe, the other end of the cooling pipe extends to the outside of the frame and is fixed with an outlet pipe, the end of the circulating air duct away from the air cover is connected to the top of the frame, and the output end of the drive motor extends into the interior of the fixed housing and is fixedly connected to the bottom end of the drive gear.

[0007] Preferably, the top end of the turntable is fixedly connected to the bottom end of the graphite support plate, the top end of the turntable is inlaid with a first sealing ring, the bottom end of the rotating shaft extends into the interior of the fixed shell and forms a rotating structure with the fixed shell, the bottom end of the fixed rod is fixedly connected to the bottom of the furnace body, and the connecting plate and the fixed rod form a sliding structure.

[0008] Preferably, the sealing structure includes a housing, a second electric push rod, a slide rod, a movable plate, a heat insulation plate, a guide rod, and a third electric push rod. The housing is fixed to one side of the furnace body. The second electric push rod passes through one side of the interior of the housing. A movable plate is fixed to one end of the second electric push rod. Slide rods pass through the interior of the housing on both sides of the second electric push rod. The third electric push rod is fixed to the top of the movable plate. A heat insulation plate is fixed to the top of the third electric push rod. Guide rods pass through the interior of the movable plate evenly.

[0009] Preferably, the slide rod and the housing form a sliding structure, one end of the slide rod is fixedly connected to one side of the moving plate, a second sealing ring is embedded in the top of the heat insulation plate, and the heat insulation plate abuts against the bottom end of the support frame through the second sealing ring.

[0010] Preferably, the guide rod and the movable plate form a sliding structure, and the top end of the guide rod is fixedly connected to the bottom end of the heat insulation plate.

[0011] Preferably, the heating structure includes a temperature sensor, a graphite frame, a through hole, a first connecting pipe, a main pipe, an exhaust pipe, and a second connecting pipe. The graphite frame is fixed to the top of the support frame. A temperature sensor passes through one side of the top of the furnace body. A first connecting pipe is fixed to one end of the top of the furnace body. Through holes are uniformly passed through the top of the graphite frame. A second connecting pipe is fixed to the outer wall of the furnace body on one side below the support frame. A main pipe is fixed to one end of both the first and second connecting pipes. An exhaust pipe is fixed to one side of the main pipe.

[0012] Preferably, the output terminal of the temperature sensor is electrically connected to the input terminal of the graphite frame via a microcontroller.

[0013] A quenching method for a quenching apparatus for machining stepped drills includes the following steps: S1. Open the furnace door, insert the step drill rod into the matching placement slot, then close the furnace door and start the vacuum pump. This allows air inside the furnace to enter the main pipe through the through hole, the first connecting pipe, and the second connecting pipe. The gas is discharged through the output end of the vacuum pump. By evacuating the furnace to a vacuum state, workpiece oxidation can be avoided. The step drill is vertically clamped in the placement slot to prevent workpiece deformation due to its own weight, while ensuring that the cutting edge is fully exposed to the airflow. At this time, start the third electric push rod, which drives the heat insulation plate to extend and retract. The heat insulation plate will drive the guide rod to move inside the moving plate. Under the action of the guide rod, the stability of the heat insulation plate during movement is enhanced. After the heat insulation plate moves, it causes the second sealing ring to separate from the bottom of the support frame. At this time, start the second electric push rod, which drives the moving plate to extend and retract. The moving plate will drive the slide rod to move inside the shell. Under the action of the slide rod, the stability of the moving plate during movement is enhanced. After the moving plate moves, it causes the heat insulation plate to move inside the shell. At this time, start the first electric push rod. S2. The first electric push rod drives the fixed shell to extend and retract. The fixed shell will drive the connecting plate to move outside the fixed rod. Under the action of the connecting plate, the stability of the fixed shell during movement is enhanced. After the fixed shell moves, it will drive the graphite bearing plate to rise and fall through the turntable. When the turntable drives the first sealing ring to abut against the bottom of the support frame, the sealing between the turntable and the support frame is enhanced under the action of the first sealing ring. At this time, the graphite bearing plate drives the workpiece to move to the inside of the graphite frame at the top of the furnace body through the placement groove. The power supply is connected, and the graphite frame generates high temperature to heat the stepped drill on the graphite bearing plate. The temperature inside the furnace body is monitored in real time through the temperature sensor to realize vacuum austenitizing heating of the stepped drill and precise temperature control. S3. After heating is completed, the first electric push rod drives the fixed shell to retract, and at the same time the second electric push rod drives the moving plate to move to the outside of the shell. When the moving plate moves to the bottom of the support frame, the third electric push rod drives the heat insulation plate to extend and retract. The moved heat insulation plate drives the second sealing ring to abut against the bottom of the support frame. Under the action of the second sealing ring, the sealing between the heat insulation plate and the support frame is enhanced, thereby blocking the heat leakage inside the graphite frame, reducing heating energy consumption, and preventing the leakage of cold air during the cooling stage. Then, the nitrogen inlet pipe is connected to high-pressure nitrogen, allowing high-pressure nitrogen to enter the bottom of the furnace body. S4. Start the negative pressure fan to circulate nitrogen for cooling. When hot nitrogen is drawn into the frame, coolant enters the cooling pipe through the inlet pipe and exits through the outlet pipe. The coolant circulates within the cooling pipe, cooling the hot nitrogen into cold nitrogen. The cold nitrogen enters the fan shroud through the circulating duct and is then evenly sprayed onto the rotating stepped drill through the perforated guide plate. The perforated guide plate ensures uniform airflow and prevents slow cooling in certain areas. Start the drive motor to rotate the drive gear. The drive gear, through the driven gear, rotates the shaft, which in turn rotates the turntable and graphite support plate. The graphite support plate rotates the workpiece through the placement slot, ensuring that the stepped drill is cooled evenly from all directions during the cooling process, reducing bending and torsional deformation.

[0014] The present invention provides a quenching device and quenching method for machining stepped drills, the advantages of which are: With a cooling structure, when the first electric push rod drives the fixed shell to extend and retract, the stability of the fixed shell during movement is enhanced by the connecting plate. After the fixed shell moves, it drives the graphite support plate to rise and fall via the turntable. When the graphite support plate moves the workpiece to the top of the furnace body via the placement groove, it facilitates heating. The sealing between the turntable and the support frame is enhanced by the first sealing ring. When the graphite support plate moves the workpiece to the bottom of the furnace body via the placement groove, it facilitates cooling. High-pressure nitrogen is connected to the outside of the nitrogen inlet pipe, allowing the high-pressure nitrogen to enter the bottom of the furnace body. At this time, the negative pressure fan is started to circulate and cool the nitrogen. When the hot nitrogen is drawn into the frame, it can be cooled into cold nitrogen by the cooling pipe. The cold nitrogen enters the interior of the air hood through the circulating air pipe, and then is evenly sprayed onto the rotating stepped drill by the perforated guide plate. The perforated guide plate ensures uniform airflow and prevents slow local cooling. Furthermore, when the drive motor drives the active gear to rotate, the active gear will drive the rotating shaft to rotate through the driven gear, causing the rotating shaft to drive the turntable and graphite support plate to rotate. The graphite support plate will drive the workpiece to rotate through the placement groove, thereby ensuring that the stepped drill is cooled evenly in all directions during the cooling process, reducing bending and torsional deformation. With a sealing structure, when the second electric push rod drives the moving plate to extend or retract, the stability of the moving plate during movement is enhanced by the action of the slide rod. When the moving plate moves to the bottom of the support frame, the third electric push rod drives the heat insulation plate to extend or retract. Under the action of the guide rod, the stability of the heat insulation plate during movement is enhanced. After the heat insulation plate moves, it causes the second sealing ring to abut against the bottom of the support frame. Under the action of the second sealing ring, the sealing between the heat insulation plate and the support frame is enhanced, thereby blocking the heat leakage from the graphite frame, reducing heating energy consumption, and preventing the leakage of cold air during the cooling stage. By incorporating a heating structure and connecting an external vacuum pump through an extraction pipe, air from inside the furnace enters the main pipe through through-holes, the first connecting pipe, and the second connecting pipe. The gas is then discharged through the output of the vacuum pump. By evacuating the furnace to a vacuum state, workpiece oxidation can be prevented. The stepped drill is vertically clamped in a placement slot to prevent deformation due to its own weight, while ensuring that the cutting edge is fully exposed to the airflow. At this time, the graphite frame is energized to generate high temperature, which heats the stepped drill on the graphite support plate. The temperature inside the furnace is monitored in real time by a temperature sensor. When the temperature reaches the preset value, the temperature sensor will control the graphite frame to stop working via a microcontroller, thus achieving vacuum austenitizing heating of the stepped drill and precise temperature control. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of the present invention in frontal cross-section; Figure 3This is a partial three-dimensional structural schematic diagram of the cooling structure of the present invention, taken from a front cross-sectional view. Figure 4 This is a partial three-dimensional structural schematic diagram of the cooling structure of the present invention from a side cross-section. Figure 5 This is a three-dimensional structural schematic diagram of the cooling structure, graphite support plate, and placement groove of the present invention, viewed in front cross section. Figure 6 This is an exploded cross-sectional view of the cooling structure of the present invention. Figure 7 This is a three-dimensional structural schematic diagram of the cooling structure, graphite support plate, and placement groove of the present invention, viewed from a side cross-section. Figure 8 This is a side view cross-sectional three-dimensional structural schematic diagram of the present invention; Figure 9 This is a top-view cross-sectional three-dimensional structural schematic diagram of the present invention; Figure 10 This is a top-view cross-sectional three-dimensional structural diagram of the sealing structure of the present invention.

[0016] The following are the annotations in the diagram: 1. Furnace body; 2. Nitrogen inlet pipe; 3. Cooling structure; 31. First electric push rod; 32. Frame; 33. Cooling pipe; 34. Negative pressure fan; 35. Fan shroud; 36. Perforated guide plate; 37. Circulating air duct; 38. Drive motor; 39. Drive gear; 310. Fixed shell; 311. Turntable; 312. Fixed rod; 313. Rotating shaft; 314. Driven gear; 315. Connecting plate. ; 4. Sealing structure; 41. Housing; 42. Second electric push rod; 43. Slide rod; 44. Moving plate; 45. Heat insulation plate; 46. Guide rod; 47. Third electric push rod; 5. Furnace door; 6. Graphite support plate; 7. Placement slot; 8. Heating structure; 81. Temperature sensor; 82. Graphite frame; 83. Through hole; 84. First connecting pipe; 85. Main pipe; 86. Evacuation pipe; 87. Second connecting pipe; 9. Support frame. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figures 1-10The present invention provides a quenching device for processing stepped drills, comprising a furnace body 1, a nitrogen inlet pipe 2 fixed on one side of the bottom of the furnace body 1, a support frame 9 fixed inside the furnace body 1, and a heating structure 8 fixed at the top of the support frame 9. The heating structure 8 includes a temperature sensor 81, a graphite frame 82, a through hole 83, a first connecting pipe 84, a main pipe 85, an exhaust pipe 86, and a second connecting pipe 87. The graphite frame 82 is fixed to the top of the support frame 9. The temperature sensor 81 passes through one side of the top of the furnace body 1. The first connecting pipe 84 is fixed at one end of the top of the furnace body 1. The through holes 83 are uniformly passed through the top of the graphite frame 82. The second connecting pipe 87 is fixed on the outer wall of the furnace body 1 below the support frame 9. The main pipe 85 is fixed at one end of both the first connecting pipe 84 and the second connecting pipe 87. The exhaust pipe 86 is fixed on one side of the main pipe 85. The output end of the temperature sensor 81 is electrically connected to the input end of the graphite frame 82 through a microcontroller.

[0019] Reference Figure 2 and Figure 8 As shown, an external vacuum pump is connected to the evacuation pipe 86, allowing air inside the furnace body 1 to enter the main pipe 85 through the through hole 83, the first connecting pipe 84, and the second connecting pipe 87. The gas is discharged through the output end of the vacuum pump. By evacuating the furnace body 1 to a vacuum state, workpiece oxidation can be avoided. The stepped drill is vertically clamped in the placement slot 7 to prevent deformation due to its own weight, while ensuring that the cutting edge is fully exposed to the airflow. When the power is connected, the graphite frame 82 is energized to generate high temperature, which heats the stepped drill on the graphite support plate 6. The temperature inside the furnace body 1 is monitored in real time by the temperature sensor 81. When the temperature reaches the preset value, the temperature sensor 81 will control the graphite frame 82 to stop working through the microcontroller, realizing vacuum austenitizing heating of the stepped drill and precise temperature control.

[0020] A furnace door 5 is provided at one end of the bottom of the furnace body 1. A sealing structure 4 is fixed to one side of the furnace body 1. The sealing structure 4 includes a shell 41, a second electric push rod 42, a slide rod 43, a moving plate 44, a heat insulation plate 45, a guide rod 46, and a third electric push rod 47. The shell 41 is fixed to one side of the furnace body 1. The second electric push rod 42 passes through one side of the interior of the shell 41. A moving plate 44 is fixed to one end of the second electric push rod 42. Slide rods 43 and moving plates 44 pass through the interior of the shell 41 on both sides of the second electric push rod 42. A third electric push rod 47 is fixed at the top, and a heat insulation plate 45 is fixed at the top of the third electric push rod 47. Guide rods 46 are evenly inserted through the interior of the moving plate 44. The sliding rod 43 and the housing 41 form a sliding structure. One end of the sliding rod 43 is fixedly connected to one side of the moving plate 44. A second sealing ring is embedded at the top of the heat insulation plate 45. The heat insulation plate 45 abuts against the bottom end of the support frame 9 through the second sealing ring. The guide rod 46 and the moving plate 44 form a sliding structure. The top end of the guide rod 46 is fixedly connected to the bottom end of the heat insulation plate 45.

[0021] Reference Figure 2 , Figure 9 and Figure 10 As shown, the second electric push rod 42 is activated, causing the moving plate 44 to extend and retract. The moving plate 44 then moves the sliding rod 43 inside the housing 41. Under the action of the sliding rod 43, the stability of the moving plate 44 during movement is enhanced. When the moving plate 44 moves to the bottom of the support frame 9, the third electric push rod 47 is activated, causing the heat insulation plate 45 to extend and retract. The heat insulation plate 45 then moves the guide rod 46 inside the moving plate 44. Under the action of the guide rod 46, the stability of the heat insulation plate 45 during movement is enhanced. After moving, the heat insulation plate 45 causes the second sealing ring to abut against the bottom of the support frame 9. Under the action of the second sealing ring, the sealing between the heat insulation plate 45 and the support frame 9 is enhanced, thereby preventing heat leakage from the graphite frame 82, reducing heating energy consumption, and preventing cold air leakage during the cooling stage.

[0022] A cooling structure 3 is fixed to the bottom of the furnace body 1. The cooling structure 3 includes a first electric push rod 31 fixed to the bottom of the furnace body 1. A fixed shell 310 is fixed to the top of the first electric push rod 31. A drive gear 39 is provided on one side inside the fixed shell 310. A driven gear 314 is meshed on one side of the drive gear 39. A rotating shaft 313 passes through the inside of the driven gear 314. The top of the rotating shaft 313 extends to the outside of the fixed shell 310 and is fixed with a turntable 311. Frames 32 pass through both sides of the furnace body 1. A fan hood 35 passes through the inside of the furnace body 1 above the frame 32. A perforated guide plate 36 is fixed inside the fan hood 35. A negative pressure fan 34 is fixed inside the frame 32. A cooling pipe 33 is fixed inside the frame 32 on one side of the negative pressure fan 34. A circulating air duct 37 is evenly fixed on one side of the fan hood 35. A drive motor 38 is installed at the bottom of the fixed shell 310 below the drive gear 39. A connecting plate 315 is fixed on one side of the furnace body 1. A fixing rod 312 passes through the inside of the connecting plate 315. One end of the cooling pipe 33 extends to the outside of the frame 32 and is fixed with an inlet pipe. The other end of the cooling pipe 33 extends to the outside of the frame 32 and is fixed with a drain pipe. The end of the circulating air pipe 37 away from the air cover 35 is connected to the top of the frame 32. The output end of the drive motor 38 extends to the inside of the fixed shell 310 and is fixedly connected to the bottom end of the drive gear 39. The top end of the turntable 311 is fixedly connected to the bottom end of the graphite support plate 6. A first sealing ring is embedded in the top of the turntable 311. The bottom end of the rotating shaft 313 extends to the inside of the fixed shell 310 and forms a rotating structure with the fixed shell 310. The bottom end of the fixing rod 312 is fixedly connected to the bottom of the furnace body 1. The connecting plate 315 and the fixing rod 312 form a sliding structure. A graphite support plate 6 is fixed to the top of the cooling structure 3. Placement slots 7 are evenly opened on the top of the graphite support plate 6.

[0023] Reference Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the first electric push rod 31 is activated, causing the fixed shell 310 to extend and retract. The fixed shell 310 then moves the connecting plate 315 outside the fixed rod 312. Under the action of the connecting plate 315, the stability of the fixed shell 310 during movement is enhanced. After moving, the fixed shell 310 drives the graphite support plate 6 to rise and fall via the turntable 311. When the turntable 311 causes the first sealing ring to abut against the bottom of the support frame 9, the sealing between the turntable 311 and the support frame 9 is enhanced. At this time, the graphite support plate 6 moves the workpiece to the inside of the graphite frame 82 at the top of the furnace body 1 via the placement groove 7 for easy heating. When the graphite support plate 6 moves the workpiece to the bottom of the furnace body 1 via the placement groove 7 for easy cooling, high-pressure nitrogen is connected to the nitrogen inlet pipe 2 to allow high-pressure nitrogen to enter the bottom of the furnace body 1. At this time, the negative pressure fan is activated. 34. Nitrogen gas is circulated for cooling. When hot nitrogen is drawn into the frame 32, coolant enters the cooling pipe 33 through the inlet pipe and is discharged through the outlet pipe. The coolant circulates within the cooling pipe 33, cooling the hot nitrogen into cold nitrogen. The cold nitrogen enters the fan hood 35 through the circulating air duct 37 and is then evenly sprayed onto the rotating stepped drill through the perforated guide plate 36. The perforated guide plate 36 ensures uniform airflow and prevents slow local cooling. The drive motor 38 is started, causing the drive motor 38 to drive the drive gear 39 to rotate. The drive gear 39 drives the rotating shaft 313 through the driven gear 314, causing the rotating shaft 313 to drive the turntable 311 and the graphite support plate 6 to rotate. The graphite support plate 6 drives the workpiece to rotate through the placement groove 7, thus ensuring that the stepped drill is cooled evenly from all directions during the cooling process, reducing bending and torsional deformation.

[0024] A quenching method for a quenching apparatus for machining stepped drills includes the following steps: S1. Open the furnace door 5, insert the step drill rod into its matching placement slot 7, then close the furnace door 5 and start the vacuum pump. Air inside the furnace body 1 enters the main pipe 85 through the through hole 83, the first connecting pipe 84, and the second connecting pipe 87. The gas is discharged through the output end of the vacuum pump. By evacuating the furnace body 1 to a vacuum state, workpiece oxidation can be prevented. The step drill is vertically clamped in the placement slot 7 to prevent workpiece deformation due to its own weight, while ensuring the cutting edge is fully exposed to the airflow. At this time, activate the third electric push rod 47, causing the heat insulation plate 45 to extend and retract. The guide rod 46 will move inside the movable plate 44. Under the action of the guide rod 46, the stability of the heat insulation plate 45 during movement is enhanced. After the heat insulation plate 45 moves, it causes the second sealing ring to separate from the bottom of the support frame 9. At this time, the second electric push rod 42 is activated, which causes the movable plate 44 to extend and retract. The movable plate 44 will drive the slide rod 43 to move inside the housing 41. Under the action of the slide rod 43, the stability of the movable plate 44 during movement is enhanced. After the movable plate 44 moves, it causes the heat insulation plate 45 to move into the housing 41. At this time, the first electric push rod 31 is activated. S2. The first electric push rod 31 drives the fixed shell 310 to extend and retract. The fixed shell 310 will drive the connecting plate 315 to move outside the fixed rod 312. Under the action of the connecting plate 315, the stability of the fixed shell 310 during movement is enhanced. After the fixed shell 310 moves, it will drive the graphite bearing plate 6 to rise and fall through the turntable 311. When the turntable 311 drives the first sealing ring to abut against the bottom of the support frame 9, the sealing between the turntable 311 and the support frame 9 is enhanced under the action of the first sealing ring. At this time, the graphite bearing plate 6 drives the workpiece to move to the inside of the graphite frame 82 at the top of the furnace body 1 through the placement groove 7. The power supply is connected, and the graphite frame 82 generates high temperature when powered on, which heats the stepped drill on the graphite bearing plate 6. The temperature inside the furnace body 1 is monitored in real time through the temperature sensor 81 to realize vacuum austenitizing heating of the stepped drill and precise temperature control. S3. After heating is completed, the first electric push rod 31 drives the fixed shell 310 to retract, and at the same time the second electric push rod 42 drives the moving plate 44 to move to the outside of the shell 41. When the moving plate 44 moves to the bottom of the support frame 9, the third electric push rod 47 drives the heat insulation plate 45 to extend and retract. After the heat insulation plate 45 moves, the second sealing ring abuts against the bottom of the support frame 9. Under the action of the second sealing ring, the sealing between the heat insulation plate 45 and the support frame 9 is enhanced, thereby blocking the heat leakage from the graphite frame 82, reducing heating energy consumption, and preventing the leakage of cold air during the cooling stage. Then, the nitrogen inlet pipe 2 is connected to high-pressure nitrogen, so that the high-pressure nitrogen enters the bottom of the furnace body 1. S4. Start the negative pressure fan 34 to circulate nitrogen for cooling. When hot nitrogen is drawn into the frame 32, coolant enters the cooling pipe 33 through the inlet pipe and is discharged through the outlet pipe. The coolant circulates inside the cooling pipe 33, and the hot nitrogen is cooled into cold nitrogen under the action of the cooling pipe 33. The cold nitrogen enters the fan shroud 35 through the circulating air duct 37, and is then evenly sprayed onto the rotating stepped drill through the perforated guide plate 36. Under the action of the perforated guide plate 36, the airflow is made uniform and the slow local cooling is prevented. Start the drive motor 38 to drive the drive gear 39 to rotate. The drive gear 39 will drive the rotating shaft 313 to rotate through the driven gear 314. The rotating shaft 313 will drive the turntable 311 and the graphite support plate 6 to rotate. The graphite support plate 6 will drive the workpiece to rotate through the placement groove 7, so that the stepped drill is cooled evenly in all directions during the cooling process, reducing bending and torsional deformation.

[0025] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A quenching apparatus for processing stepped drills, comprising a furnace body (1); Its features are: A nitrogen inlet pipe (2) is fixed on one side of the bottom of the furnace body (1), a support frame (9) is fixed inside the furnace body (1), a heating structure (8) is fixed at the top of the support frame (9), a furnace door (5) is provided at one end of the bottom of the furnace body (1), and a sealing structure (4) is fixed on one side of the furnace body (1). A cooling structure (3) is fixed to the bottom of the furnace body (1). The cooling structure (3) includes a first electric push rod (31) fixed to the bottom of the furnace body (1). A fixed shell (310) is fixed to the top of the first electric push rod (31). A drive gear (39) is provided on one side inside the fixed shell (310). A driven gear (314) is meshed on one side of the drive gear (39). A rotating shaft (313) passes through the interior of the driven gear (314). The top of the rotating shaft (313) extends to the fixed shell. A turntable (311) is fixed to the outside of the shell (310). Frames (32) penetrate both sides of the furnace body (1). A fan hood (35) penetrates the inside of the furnace body (1) above the frame (32). A perforated guide plate (36) is fixed inside the fan hood (35). A negative pressure fan (34) is fixed inside the frame (32). A cooling pipe (33) is fixed inside the frame (32) on one side of the negative pressure fan (34). A circulating air duct (37) is evenly fixed on one side of the fan hood (35). The top of the cooling structure (3) is fixed with a graphite support plate (6), and the top of the graphite support plate (6) is uniformly provided with placement grooves (7).

2. The quenching device for machining stepped drills according to claim 1, characterized in that: A drive motor (38) is installed at the bottom of the fixed housing (310) below the drive gear (39). A connecting plate (315) is fixed on one side of the fixed housing (310), and a fixing rod (312) passes through the inside of the connecting plate (315).

3. The quenching device for machining stepped drills according to claim 2, characterized in that: One end of the cooling pipe (33) extends to the outside of the frame (32) and is fixed with an inlet pipe. The other end of the cooling pipe (33) extends to the outside of the frame (32) and is fixed with a drain pipe. The end of the circulating air pipe (37) away from the air cover (35) is connected to the top of the frame (32). The output end of the drive motor (38) extends to the inside of the fixed shell (310) and is fixedly connected to the bottom end of the drive gear (39).

4. The quenching device for machining stepped drills according to claim 2, characterized in that: The top of the turntable (311) is fixedly connected to the bottom of the graphite support plate (6). The top of the turntable (311) is inlaid with a first sealing ring. The bottom of the rotating shaft (313) extends into the interior of the fixed shell (310) and forms a rotating structure with the fixed shell (310). The bottom of the fixed rod (312) is fixedly connected to the bottom of the furnace body (1). The connecting plate (315) and the fixed rod (312) form a sliding structure.

5. The quenching device for machining stepped drills according to claim 1, characterized in that: The sealing structure (4) includes a housing (41), a second electric push rod (42), a slide rod (43), a moving plate (44), a heat insulation plate (45), a guide rod (46), and a third electric push rod (47). The housing (41) is fixed to one side of the furnace body (1). The second electric push rod (42) passes through one side of the interior of the housing (41). The moving plate (44) is fixed to one end of the second electric push rod (42). The slide rod (43) passes through the interior of the housing (41) on both sides of the second electric push rod (42). The third electric push rod (47) is fixed to the top of the moving plate (44). The heat insulation plate (45) is fixed to the top of the third electric push rod (47). The guide rod (46) passes through the interior of the moving plate (44) evenly.

6. The quenching apparatus for machining stepped drills according to claim 5, characterized in that: The slide rod (43) and the housing (41) form a sliding structure. One end of the slide rod (43) is fixedly connected to one side of the moving plate (44). The top of the heat insulation plate (45) is inlaid with a second sealing ring. The heat insulation plate (45) abuts against the bottom of the support frame (9) through the second sealing ring.

7. The quenching apparatus for machining stepped drills according to claim 5, characterized in that: The guide rod (46) and the movable plate (44) form a sliding structure, and the top end of the guide rod (46) is fixedly connected to the bottom end of the heat insulation plate (45).

8. The quenching device for machining stepped drills according to claim 1, characterized in that: The heating structure (8) includes a temperature sensor (81), a graphite frame (82), a through hole (83), a first connecting pipe (84), a main pipe (85), an exhaust pipe (86), and a second connecting pipe (87). The graphite frame (82) is fixed to the top of the support frame (9). The temperature sensor (81) passes through one side of the top of the furnace body (1). The first connecting pipe (84) is fixed to one end of the top of the furnace body (1). The through hole (83) is uniformly passed through the top of the graphite frame (82). The second connecting pipe (87) is fixed to the outer wall of the furnace body (1) on one side below the support frame (9). The main pipe (85) is fixed to one end of both the first connecting pipe (84) and the second connecting pipe (87). The exhaust pipe (86) is fixed to one side of the main pipe (85).

9. A quenching apparatus for machining stepped drills according to claim 8, characterized in that: The output of the temperature sensor (81) is electrically connected to the input of the graphite frame (82) via a microcontroller.

10. A quenching method for a quenching apparatus for machining stepped drills, comprising the following steps, characterized in that: S1. Open the furnace door (5), insert the step drill rod into the matching placement slot (7), then close the furnace door (5) and start the vacuum pump. The air inside the furnace body (1) enters the main pipe (85) through the through hole (83), the first connecting pipe (84), and the second connecting pipe (87). The gas is discharged through the output end of the vacuum pump. By drawing the furnace body (1) into a vacuum state, the workpiece oxidation can be avoided. The step drill is vertically clamped in the placement slot (7) to avoid deformation due to its own weight, while ensuring that the cutting edge is fully exposed to the airflow. At this time, start the third electric push rod (47) to drive the heat insulation plate (45) to extend and retract. The heat insulation plate (45) will drive the guide The guide rod (46) moves inside the moving plate (44). Under the action of the guide rod (46), the stability of the heat insulation plate (45) during movement is enhanced. After the heat insulation plate (45) moves, it causes the second sealing ring to separate from the bottom of the support frame (9). At this time, the second electric push rod (42) is activated, causing the second electric push rod (42) to drive the moving plate (44) to extend and retract. The moving plate (44) will drive the slide rod (43) to move inside the housing (41). Under the action of the slide rod (43), the stability of the moving plate (44) during movement is enhanced. After the moving plate (44) moves, it causes the heat insulation plate (45) to move inside the housing (41). At this time, the first electric push rod (31) is activated. S2. The first electric push rod (31) drives the fixed shell (310) to extend and retract. The fixed shell (310) will drive the connecting plate (315) to move outside the fixed rod (312). Under the action of the connecting plate (315), the stability of the fixed shell (310) during movement is enhanced. After the fixed shell (310) moves, it will drive the graphite bearing plate (6) to rise and fall through the turntable (311). When the turntable (311) drives the first sealing ring to abut against the bottom end of the support frame (9), the first sealing ring will move and retract. Under the action of a sealing ring, the sealing between the turntable (311) and the support frame (9) is enhanced. At this time, the graphite support plate (6) moves the workpiece to the inside of the graphite frame (82) at the top of the furnace body (1) through the placement groove (7). The power supply is connected, and the graphite frame (82) generates high temperature when powered on, which heats the stepped drill on the graphite support plate (6). The temperature inside the furnace body (1) is monitored in real time by the temperature sensor (81) to realize vacuum austenitizing heating of the stepped drill and precise temperature control. S3. After heating is completed, the first electric push rod (31) drives the fixed shell (310) to retract, and at the same time the second electric push rod (42) drives the moving plate (44) to move to the outside of the shell (41). When the moving plate (44) moves to the bottom of the support frame (9), the third electric push rod (47) drives the heat insulation plate (45) to extend and retract. The moved heat insulation plate (45) drives the second sealing ring to abut against the bottom of the support frame (9). Under the action of the second sealing ring, the sealing between the heat insulation plate (45) and the support frame (9) is enhanced, thereby blocking the heat leakage inside the graphite frame (82), reducing heating energy consumption, and preventing the cold air leakage during the cooling stage. Then, the nitrogen inlet pipe (2) is connected to high-pressure nitrogen, so that the high-pressure nitrogen enters the bottom of the furnace body (1). S4. Start the negative pressure fan (34) to circulate and cool the nitrogen. When the hot nitrogen is drawn into the frame (32), the coolant enters the cooling pipe (33) through the inlet pipe and is discharged through the drain pipe. The coolant circulates inside the cooling pipe (33), and under the action of the cooling pipe (33), the hot nitrogen is cooled into cold nitrogen. The cold nitrogen enters the fan hood (35) through the circulating air duct (37) and is then evenly sprayed onto the rotating stepped drill through the perforated guide plate (36). Under the action of the drive motor (38), the airflow is uniform and local slow cooling is prevented; the drive motor (38) is started, and the drive motor (38) drives the drive gear (39) to rotate. The drive gear (39) will drive the shaft (313) to rotate through the driven gear (314), and the shaft (313) will drive the turntable (311) and the graphite support plate (6) to rotate. The graphite support plate (6) will drive the workpiece to rotate through the placement groove (7), so that the stepped drill is cooled evenly in all directions during the cooling process, reducing bending and torsional deformation.

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