Annealing equipment and process for gradient hardness treatment of shield cutter

Abstract

The annealing equipment comprises a workbench, a clamping mechanism, an annealing table and a driving box, a plurality of regular and different limiting insertion holes are formed in the two sides of the upper surface of the workbench correspondingly, limiting rods are detachably arranged in the limiting insertion holes, and cutter bodies are placed on the upper surfaces of the limiting insertion holes; the limiting rod is used for limiting the cutter body; a liftable lifting frame is arranged at the front end of the clamping mechanism, a first pneumatic assembly is arranged on the upper surface of the lifting frame, a first clamping claw is arranged on the lower surface of the lifting frame, and the first clamping claw clamps and fixes a tool body through the first pneumatic assembly; a second clamping jaw pneumatically moving to the center of a circle is arranged on the upper surface of the annealing table; a motor and a cylinder are arranged at the lower end of the annealing table; the front end of the driving box is in heat conduction connection with a connecting rod, and a temperature sensor is installed in the joint of the connecting rod and the induction coil. The invention discloses annealing equipment for gradient hardness treatment of a shield cutter and a process of the annealing equipment. The comprehensive performance of the cutter can be comprehensively improved through two-time preheating and one-time annealing.

Description

Technical Field

[0001] The invention relates to the technical field of shield tool processing, and in particular to an annealing device and a process thereof for gradient hardness treatment of shield tools. Background Art

[0002] Annealing process is an important part of improving the performance of shield tools. It can improve the microstructure of the tool, thereby improving its toughness, reducing the risk of cracking and other comprehensive performance.

[0003] In the traditional annealing method, the shield cutter will face uneven temperature distribution due to the different placement positions in the equipment. The temperature rises quickly near the heating source and slowly away from the heating source, which in turn affects the quality and performance of the cutter and reduces its service life and work efficiency.

[0004] Furthermore, in the manufacturing process of shield tools, sometimes only the inner ring of the tool needs to be annealed. However, traditional annealing methods make it difficult to achieve precise control of such local annealing. Traditional overall heating methods often cause areas that do not require annealing to be heated, thereby changing the original performance of these areas and increasing the difficulty of subsequent processing.

[0005] In summary, we proposed an annealing equipment and process for gradient hardness treatment of shield tools to solve the above-mentioned problems. Summary of the invention

[0006] The purpose of the present invention is to provide an annealing device and a process for gradient hardness treatment of shield tools. The comprehensive performance of the tool can be comprehensively improved through two preheating and one annealing process, and each stage has a positive effect on hardness, toughness and stress distribution.

[0007] To achieve the above object, the present invention proposes the following scheme: An annealing device for gradient hardness treatment of shield tool comprises a workbench, a clamping mechanism, an annealing table and a drive box. A plurality of limit sockets with different rules are respectively provided on both sides of the upper surface of the workbench, and a limit rod is detachably provided inside the limit socket, and a tool body is placed on the upper surface of the limit socket, and the limit rod is used to limit the tool body; A lifting frame that can be raised and lowered is provided at the front end of the clamping mechanism, a first pneumatic component is provided on the upper surface of the lifting frame, and a first clamp is provided on the lower surface thereof, and the first clamp clamps the tool body through the first pneumatic component; The upper surface of the annealing table is provided with a second clamping jaw which can be moved toward the center of the circle by pneumatic means, and the lower end of the annealing table is provided with a motor and a cylinder; The front end of the drive box is heat-conductingly connected with a connecting rod, a temperature sensor is installed inside the connection between the connecting rod and the induction coil, the front end of the connecting rod is fixedly connected with the induction coil, and an electric cylinder is arranged inside the drive box for secondary pushing of the connecting rod and the induction coil; The clamping mechanism is located at the front end of the upper surface of the workbench and moves back and forth laterally, and is used to clamp the tool body. The first pneumatic component controls the first clamp to clamp the tool body through the pneumatic principle. The motor is used to drive the annealing table to rotate, and the cylinder is used to drive the annealing table to rise and fall. The induction coil performs two preheating processes and one annealing process on the inner circle of the tool body.

[0008] A motor is arranged in the first driving assembly, and an output end of the motor is transmission-connected to the first screw rod and drives the first screw rod to rotate. The first screw rod is threadedly connected to the clamping mechanism.

[0009] A motor is provided inside the second driving component, and two mutually meshing reduction gears are provided inside the transmission component. The motor is transmission-connected to the reduction gears, and a lead screw vertically installed inside the clamping mechanism is fixedly connected to the lower end of the reduction gear. The front end of the lifting frame extends into the clamping mechanism through a slot and is threadedly connected to the lead screw.

[0010] A pneumatic part is provided at the lower end of the second clamping jaw and clamps the tool body through the pneumatic principle.

[0011] A propulsion cylinder is installed at the rear side of the upper end of the driving platform, guide rods are installed on both sides of the upper surface of the driving platform, a propulsion plate is fixedly connected to the output end of the propulsion cylinder, and the lower surface of the propulsion plate is slidably connected to the guide rod.

[0012] Hand wheels and second screws are arranged on both sides of the upper surface of the push plate. The hand wheels are transmission-connected with the second screws. A moving block is threadedly connected to the outer surface of the second screw. The upper surface of the moving block is threadedly connected to the lower end of the driving box.

[0013] A heating power supply control cabinet is arranged on the side end of the workbench.

[0014] The present invention provides a shield tool local annealing process: Step 1: Place the tool body to be annealed on the left end of the workbench, ensuring the position accuracy is within ±1 mm.

[0015] Step 2: Drive the clamping mechanism to move horizontally to the left end of the workbench, and drive the first clamp to descend at a speed of 6-8 cm / s to grab the tool body, and place the tool body on the annealing table, drive the second clamp to clamp the tool body, and at the same time, move the induction coil forward and adjust to the upper end of the tool body ring to start the first stage of preheating.

[0016] Step 3: The first preheating, the annealing table rises to a height of 30cm from the workbench. At this time, the tool body is surrounded by the induction coil. The first preheating temperature is 200℃. The annealing table rotates at 1 - 1.2 rpm and rises or falls 0.8 -1.2 cm every 5 minutes. The temperature sensor has an accuracy of ±0.5°C. Real-time monitoring is carried out and the temperature deviation is controlled within 0.5°C.

[0017] Step 4: Second preheating. After the first preheating, make transition adjustment: the annealing table descends at a speed of 3 - 4 cm / s to make the induction coil withdraw from the inner circle of the tool. At this time, the temperature drops by 10 - 15°C per minute. The annealing table stops moving and remains stationary for 1.5 - 2.5 minutes. The temperature sensor monitors in real time. After that, the annealing table rises again. The induction coil surrounds the tool body. The second preheating temperature is 400°C. The annealing table rotates at 2 - 2.2 rpm, rising or falling by 0.6 - 0.9 cm every 3 minutes. The temperature sensor monitors in real time and the temperature deviation is controlled within ±1°C.

[0018] Step 5: The third stage is high temperature annealing. After the second preheating, transition adjustment is performed: the annealing table descends at a speed of 4 - 5 cm / s to make the induction coil withdraw from the inner circle of the tool. At this time, the temperature drops by 15 - 20°C per minute. The annealing table is stationary for 2.5 - 3.5 minutes. The temperature sensor records the temperature. After that, the annealing table rises again. The induction coil surrounds the tool body. The high temperature annealing temperature is 900°C. The annealing table rotates at 3 - 3.2 rpm, rising or falling 1 - 1.3 cm every 2 minutes. The temperature sensor monitors in real time and the temperature deviation is controlled within ±2°C.

[0019] Step 6: After the high temperature annealing is completed, the induction coil is withdrawn from the inner circle of the tool at a speed of 8-10 cm / s and placed in an oven for constant temperature cooling, and then the annealing process is completed.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides an annealing device and process for gradient hardness treatment of shield tool. The limit socket on the workbench cooperates with the limit rod to accurately position the tool body, which is of great significance for improving the uniformity and quality of annealing.

[0021] (2) The present invention provides an annealing device and process for gradient hardness treatment of shield tools. The second clamp on the annealing table moves toward the center of a circle pneumatically to clamp the tool. At the same time, the motor and cylinder at the lower end can drive the annealing table to rotate and rise and fall. This design allows the tool to rotate and rise and fall slowly during the annealing process, greatly improving the uniformity of annealing, thereby improving the annealing effect and reducing the risk of the shield tool breaking during excavation.

[0022] (3) The present invention provides an annealing device and process for gradient hardness treatment of shield tool. The principle of induction coil heating is to use electromagnetic induction to generate eddy currents inside the metal workpiece. The eddy currents generate heat due to the resistance of the workpiece, thereby achieving rapid heating. In addition, the temperature sensor can monitor the temperature in real time, providing a basis for temperature adjustment in the annealing process to ensure the annealing quality.

[0023] (4) The present invention provides an annealing device and process for gradient hardness treatment of shield tools, which adopts a method of two preheating and one annealing. The first preheating can maintain the high hardness of the tool while preliminarily eliminating the quenching stress; the second preheating further optimizes the tool structure and enhances toughness; high-temperature annealing can effectively eliminate most of the quenching stress and make the internal stress distribution of the tool more uniform. Compared with single-temperature annealing, this multi-stage annealing can more comprehensively improve the comprehensive performance of the tool, such as hardness, toughness and dimensional stability.

[0024] (5) In the annealing equipment and process for gradient hardness treatment of shield tools of the present invention, in the transition link of each annealing stage, the parameters such as the descent speed of the annealing table, the temperature drop rate and the static time are reasonably set, which helps to stabilize the temperature of the tool and prevent the tool from being adversely affected by rapid temperature changes.

[0025] (6) The present invention provides an annealing device and process for gradient hardness treatment of shield tool. After high-temperature annealing, the induction coil is withdrawn from the inner ring of the tool at a speed of 8-10 cm / s and placed in an oven for constant temperature cooling (230-300°C for 4 hours). This cooling method can not only quickly reduce the tool temperature, but also avoid defects such as cracks in the tool caused by excessive cooling, which helps to improve the quality and service life of the tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A perspective view of the whole of the present invention; Figure 2 A schematic diagram of another angle of the present invention; Figure 3 It is a schematic diagram of the workbench structure of the present invention; Figure 4 is a schematic diagram of the driving platform structure of the present invention; Figure 5 Schematic diagram of the propulsion plate structure of the present invention.

[0027] In the figure: 1. workbench; 11. first drive assembly; 12. first screw; 13. limit socket; 131. limit rod; 2. clamping mechanism; 21. second drive assembly; 22. transmission assembly; 23. lifting frame; 231. first pneumatic assembly; 232. first clamp; 3. annealing table; 31. second clamp; 4. drive table; 41. propulsion cylinder; 42. guide rod; 43. propulsion plate; 431. hand wheel; 432. second screw; 433. moving block; 5. drive box; 51. connecting rod; 52. induction coil; 6. heating power supply control cabinet; a. tool body. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0029] See also Figure 1-5 An annealing device for gradient hardness treatment of shield tool comprises a workbench 1, a clamping mechanism 2, an annealing table 3 and a driving box 5. A plurality of limit sockets 13 with different rules are respectively provided on both sides of the upper surface of the workbench 1. A limit rod 131 is detachably provided inside the limit socket 13. A tool body a is placed on the upper surface of the limit socket 13. The limit rod 131 is used to limit the tool body a. A lifting frame 23 that can be raised and lowered is provided at the front end of the clamping mechanism 2. A first pneumatic component 231 is provided on the upper surface of the lifting frame 23, and a first clamping grip 232 is provided on the lower surface thereof. The first clamping grip 232 clamps the tool body a through the first pneumatic component 231. The upper surface of the annealing table 3 is provided with a second clamping jaw 31 which moves toward the center of the circle by pneumatic means, and the lower end of the annealing table 3 is provided with a motor and a cylinder; The front end of the driving box 5 is heat-conductingly connected to a connecting rod 51, a temperature sensor is installed inside the connection between the connecting rod 51 and the induction coil 52, the front end of the connecting rod 51 is fixedly connected to the induction coil 52, and an electric cylinder is provided inside the driving box 5 for secondary pushing of the connecting rod 51 and the induction coil 52; The clamping mechanism 2 is located at the front end of the upper surface of the workbench 1 and moves back and forth laterally, and is used to clamp the tool body a. The first pneumatic component 231 controls the first clamp 232 to clamp the tool body a through the pneumatic principle. The motor is used to drive the annealing table 3 to rotate, and the cylinder is used to drive the annealing table 3 to rise and fall. The induction coil 52 performs two preheating processes and one annealing process on the inner ring of the tool body a. When in use, the temperature sensor is fixedly installed on the inner wall of the connecting rod 51, which can monitor the temperature in real time and transmit the signal to the heating power supply control cabinet 6 to adjust the temperature of the induction coil 52, thereby performing two preheating processes and one annealing process.

[0030] Furthermore, a motor is provided in the first drive component 11, and the output end of the motor is connected to the first screw 12 and drives the first screw 12 to rotate. The first screw 12 is threadedly connected to the clamping mechanism 2. When in use, starting the motor inside the first drive component 11 can drive the first screw 12 to rotate, and then drive the clamping mechanism 2 to move back and forth horizontally, thereby realizing the loading and unloading operations of the tool body a.

[0031] Furthermore, a motor is provided inside the second drive component 21, and two mutually meshing reduction gears are provided inside the transmission component 22. The motor is connected to the reduction gear in transmission. The lower end of the reduction gear is fixedly connected to a screw rod vertically installed inside the clamping mechanism 2. The front end of the lifting frame 23 extends into the clamping mechanism 2 through a slot and is threadedly connected to the screw rod. When in use, starting the motor inside the second drive component 21 can drive the reduction gear inside the transmission component 22 to rotate, and then drive the screw rod to rotate. The screw rod drives the lifting frame 23 and the first clamp 232 to rise and fall, thereby completing the gripping of the tool body a.

[0032] Furthermore, a pneumatic part is provided at the lower end of the second clamp 31 and the tool body a is clamped by the pneumatic principle. When in use, starting the pneumatic part can drive the second clamp 31 to move toward the center of the annealing table 3, thereby clamping the tool body a. The motor and cylinder provided at the lower end of the annealing table 3 can drive the annealing table 3 to rotate and rise and fall, thereby making the tool body a rotate and slowly rise and fall during annealing, which can greatly improve the annealing uniformity of the tool body a and thereby improve the annealing effect.

[0033] Furthermore, a propulsion cylinder 41 is installed on the rear side of the upper end of the driving platform 4, and guide rods 42 are installed on both sides of the upper surface of the driving platform 4. The output end of the propulsion cylinder 41 is fixedly connected to a propulsion plate 43, and the lower surface of the propulsion plate 43 is slidably connected to the guide rod 42. When in use, starting the propulsion cylinder 41 can push the propulsion plate 43 and the driving box 5 at its upper end, thereby enabling the induction coil 52 to be accurately moved to the upper end of the inner circle of the tool body a.

[0034] Furthermore, a handwheel 431 and a second screw 432 are provided on both sides of the upper surface of the push plate 43, the handwheel 431 is transmission-connected to the second screw 432, a moving block 433 is threadedly connected to the outer surface of the second screw 432, and the upper surface of the moving block 433 is threadedly connected to the lower end of the drive box 5. When in use, by rotating the handwheel 431, the handwheel 431 drives the second screw 432 to rotate, and then the driving box 5 can be driven to move left and right through the moving block 433, so that the left and right position of the driving box 5 can be fine-tuned to ensure that the induction coil 52 is accurately located at the upper end of the inner circle of the tool body a.

[0035] Furthermore, a heating power supply control cabinet 6 is provided at the side end of the workbench 1. When in use, the heating power supply control cabinet 6 receives and transmits data and controls the whole.

[0036] A shield tool local annealing process, comprising: Step 1: Place the tool body a to be annealed on the left end of the workbench 1, ensuring that the position accuracy is within ±1 mm.

[0037] Step 2: Drive the clamping mechanism 2 to move horizontally to the left end of the workbench 1, and drive the first clamping claw 232 to descend at a speed of 6-8 cm / s to grab the tool body a, and place the tool body a on the annealing table 3, drive the second clamping claw 31 to clamp the tool body a, and at the same time, move the induction coil 52 forward and adjust it to the upper end of the inner ring of the tool body a to start the first stage of preheating.

[0038] Step 3: Preheating for the first time, the annealing table 3 rises to a height of 130 cm from the workbench. At this time, the tool body a is surrounded by the induction coil 52. The first preheating temperature is 200°C. The annealing table rotates at 1 - 1.2 rpm and rises or falls by 0.8 - 1.2 cm every 5 minutes. The temperature sensor has an accuracy of ±0.5°C. Real-time monitoring is performed and the temperature deviation is controlled within 0.5°C.

[0039] Step 4: Second preheating. After the first preheating is completed, a transition adjustment is performed: the annealing table 3 descends at a speed of 3-4 cm / s, so that the induction coil 52 is withdrawn from the inner circle of the tool. At this time, the temperature drops by 10-15°C per minute. The annealing table stops moving and remains stationary for 1.5-2.5 minutes. The temperature sensor monitors in real time. After that, the annealing table 3 rises again, and the induction coil 52 surrounds the tool body a. The second preheating temperature is 400°C. The annealing table rotates at 2-2.2 rpm, rising or falling by 0.6-0.9 cm every 3 minutes. The temperature sensor monitors in real time, and the temperature deviation is controlled within ±1°C.

[0040] Step 5: The third stage is high temperature annealing. After the second preheating, transition adjustment is performed: the annealing table 3 descends at a speed of 4-5 cm / s, so that the induction coil 52 withdraws from the inner circle of the tool. At this time, the temperature drops by 15-20°C per minute. The annealing table is stationary for 2.5-3.5 minutes, and the temperature sensor records the temperature. After that, the annealing table 3 rises again, and the induction coil 52 surrounds the tool body a. The high temperature annealing temperature is 900°C. The annealing table rotates at 3-3.2 rpm, rising or falling by 1-1.3 cm every 2 minutes. The temperature sensor monitors in real time, and the temperature deviation is controlled within ±2°C.

[0041] Step 6: After the high temperature annealing is completed, the induction coil 52 is withdrawn from the inner circle of the tool at a speed of 8-10 cm / s and placed in an oven for constant temperature cooling at 230-300°C for 4 hours, and then the annealing process is completed.

[0042] In summary, the present invention proposes an annealing device and process for gradient hardness treatment of shield tools. When in use, limit sockets 13 are provided on both sides of the upper surface of the workbench 1, and the internal detachable limit rods 131 are used to place and limit the tool body a. On the lifting frame 23 at the front end of the clamping mechanism 2, the first pneumatic component 231 controls the first clamping gripper 232 to clamp the tool, which drives the first screw 12 to rotate through the motor in the first drive component 11 to achieve lateral reciprocating movement to load and unload materials. The motor in the second drive component 21 drives the screw to rotate through the transmission component 22 to lift the lifting frame 23 to complete the grasping. The second clamping claw 31 on the upper surface of the annealing table 3 pneumatically moves toward the center of the circle to clamp the tool. The lower end motor and cylinder drive the annealing table to rotate and lift respectively to improve the annealing uniformity. The driving box 5 can drive the connecting rod 51 and the induction coil 52 to move forward for a second time. The temperature sensor at the connection between the connecting rod 51 and the induction coil 52 monitors the temperature and transmits a signal to the heating power control cabinet 6 The temperature is adjusted to perform two preheating and one annealing. The principle of induction coil heating is to use electromagnetic induction to generate eddy currents inside the metal workpiece. The eddy currents generate heat due to the resistance of the workpiece, thereby achieving rapid heating. The propulsion cylinder 41 on the drive table 4 pushes the propulsion plate 43 to drive the drive box 5 to move forward and backward. The hand wheel 431 and the second screw 432 on the propulsion plate 43 fine-tune the left and right positions of the drive box 5. The annealing process is as follows: first, the tool body a is placed on the left end of the worktable 1 with a position accuracy within ±1 mm, and then the clamping mechanism 2 moves the tool to the annealing table 3, the second clamping claw 31 clamps it, and the induction coil 52 moves to the upper end of the inner circle of the tool to start the first preheating. The annealing table 3 is raised 130 cm from the worktable and is heated at a low temperature of 200 ° C with a temperature of 1 - 1.2 rpm rotation, rise or fall 0.8 - 1.2 cm every 5 minutes, temperature sensor accuracy ±0.5°C monitoring, deviation within ±0.5°C, after the first preheating, enter the second preheating, annealing table 3 descends to make the induction coil 52 withdraw the temperature drop 10 - 15°C per minute, stand still for 1.5 - 2.5 minutes, then rise to make the induction coil 52 surround the tool, 400°C preheating, annealing table rotates at 2 - 2.2 rpm, rise or fall 0.6 - 0.9 cm every 3 minutes, temperature deviation is controlled within ±1°C, high temperature annealing is performed after the second preheating, annealing table 3 descends to make the induction coil 52 withdraw the temperature drop 15 - 20°C per minute, stand still for 2.5- 3.5 minutes, then rise to make the induction coil 52 surround the tool, 900°C high temperature annealing, annealing table rotates at 3 - 3.2 rpm, rise or fall 1 - 1.3 cm, the temperature deviation is controlled within ±2°C. After the high-temperature annealing is completed, the induction coil is withdrawn from the inner circle of the tool at a speed of 8-10 cm / s and placed in an oven for constant temperature cooling at 230-300°C for 4 hours. Finally, the clamping mechanism 2 places the tool on the right side of the workbench 1 to complete the annealing.

Claims

1. An annealing device for gradient hardness treatment of shield tool, comprising a workbench (1), a clamping mechanism (2), an annealing table (3) and a drive box (5), characterized in that: A plurality of limit sockets (13) of different regularities are respectively provided on both sides of the upper surface of the workbench (1), a limit rod (131) is detachably provided inside the limit socket (13), a tool body (a) is placed on the upper surface of the limit socket (13), and the limit rod (131) is used to limit the tool body (a); A lifting frame (23) that can be lifted and lowered is provided at the front end of the clamping mechanism (2); a first pneumatic component (231) is provided on the upper surface of the lifting frame (23); a first clamping grip (232) is provided on the lower surface of the lifting frame (23); the first clamping grip (232) clamps the tool body (a) through the first pneumatic component (231); The upper surface of the annealing table (3) is provided with a second clamping claw (31) that moves toward the center of the circle by pneumatic means, and the lower end of the annealing table (3) is provided with a motor and a cylinder; The front end of the drive box (5) is heat-conductingly connected to a connecting rod (51), a temperature sensor is installed inside the connection between the connecting rod (51) and the induction coil (52), the front end of the connecting rod (51) is fixedly connected to the induction coil (52), and an electric cylinder is provided inside the drive box (5) for secondary pushing of the connecting rod (51) and the induction coil (52); The clamping mechanism (2) is located at the front end of the upper surface of the workbench (1) and moves back and forth laterally, and is used to clamp the tool body (a). The first pneumatic component (231) controls the first clamp (232) to clamp the tool body (a) through the pneumatic principle. The motor is used to drive the annealing table (3) to rotate, and the cylinder is used to drive the annealing table (3) to rise and fall. The induction coil (52) performs two preheating processes and one annealing process on the inner ring of the tool body (a).

2. The annealing equipment for gradient hardness treatment of shield tool according to claim 1, characterized in that: A motor is provided in the first driving assembly (11); an output end of the motor is transmission-connected to the first screw rod (12) and drives the first screw rod (12) to rotate; the first screw rod (12) is threadedly connected to the clamping mechanism (2).

3. The annealing equipment for gradient hardness treatment of shield tool according to claim 2 is characterized in that: A motor is provided inside the second drive assembly (21), and two mutually meshing reduction gears are provided inside the transmission assembly (22). The motor is in transmission connection with the reduction gears, and a lead screw which is vertically installed inside the clamping mechanism (2) is fixedly connected at the lower end of the reduction gears. The front end of the lifting frame (23) extends into the clamping mechanism (2) through a slot and is threadedly connected to the lead screw.

4. The annealing equipment for gradient hardness treatment of shield tool according to claim 3 is characterized in that: A pneumatic part is provided at the lower end of the second clamping jaw (31) and clamps the tool body (a) through the pneumatic principle.

5. The annealing equipment for gradient hardness treatment of shield tool according to claim 4, characterized in that: A propulsion cylinder (41) is installed at the rear side of the upper end of the driving platform (4), guide rods (42) are installed on both sides of the upper surface of the driving platform (4), a propulsion plate (43) is fixedly connected to the output end of the propulsion cylinder (41), and the lower surface of the propulsion plate (43) is slidably connected to the guide rods (42).

6. The annealing equipment for gradient hardness treatment of shield tool according to claim 5, characterized in that: A hand wheel (431) and a second screw rod (432) are provided on both sides of the upper surface of the advancement plate (43); the hand wheel (431) is drivingly connected to the second screw rod (432); a moving block (433) is threadedly connected to the outer surface of the second screw rod (432); and the upper surface of the moving block (433) is threadedly connected to the lower end of the driving box (5).

7. The annealing equipment for gradient hardness treatment of shield tool according to claim 6, characterized in that: A heating power supply control cabinet (6) is arranged at the side end of the workbench (1).

8. A shield tool local annealing process, characterized in that: include: Step 1: Place the tool body (a) to be annealed on the left end of the workbench (1), ensuring that the position accuracy is within ±1 mm; Step 2: drive the clamping mechanism (2) to move horizontally to the left end of the workbench (1), and drive the first clamping claw (232) to descend at a speed of 6-8 cm / s to grab the tool body (a), and place the tool body (a) on the annealing table (3), drive the second clamping claw (31) to clamp the tool body (a), and at the same time, move the induction coil (52) forward to the upper end of the inner ring of the tool body (a), and start the first stage of preheating; Step 3: Preheating for the first time, the annealing table (3) rises to a height of 30 cm from the workbench (1), at which time the tool body (a) is surrounded by the induction coil (52), the first preheating temperature is 200°C, the annealing table rotates at 1 - 1.2 rpm, and rises or falls 0.8 - 1.2 cm every 5 minutes, the temperature sensor has an accuracy of ±0.5°C, and real-time monitoring is performed, and the temperature deviation is controlled within 0.5°C; Step 4: Second preheating. After the first preheating is completed, a transition adjustment is performed: the annealing table (3) is lowered at a speed of 3-4 cm / s, so that the induction coil (52) is withdrawn from the inner circle of the tool. At this time, the temperature drops by 10-15°C per minute. The annealing table stops moving and remains stationary for 1.5-2.5 minutes. The temperature sensor is monitored in real time. After that, the annealing table (3) rises again, and the induction coil (52) surrounds the tool body (a). The second preheating temperature is 400°C. The annealing table rotates at 2-2.2 rpm, rising or falling by 0.6-0.9 cm every 3 minutes. The temperature sensor is monitored in real time, and the temperature deviation is controlled within ±1°C. Step 5: The third stage is high temperature annealing. After the second preheating is completed, a transition adjustment is performed: the annealing table (3) is lowered at a speed of 4-5 cm / s, so that the induction coil (52) is withdrawn from the inner circle of the tool. At this time, the temperature drops by 15-20°C per minute. The annealing table is stationary for 2.5-3.5 minutes, and the temperature sensor records the temperature. After that, the annealing table (3) rises again, and the induction coil (52) surrounds the tool body (a). The high temperature annealing temperature is 900°C. The annealing table rotates at 3-3.2 rpm, rising or falling by 1-1.3 cm every 2 minutes. The temperature sensor monitors in real time, and the temperature deviation is controlled within ±2°C. Step 6: After the high temperature annealing is completed, the induction coil (52) is withdrawn from the inner circle of the tool at a speed of 8-10 cm / s and placed in an oven for constant temperature cooling (230-300°C for 4 hours), and then the annealing process is completed.

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