A method and apparatus for uniform induction heating of a bar

Abstract

This invention discloses a method and apparatus for uniform induction heating of bars, comprising: an induction heating furnace, which is mounted on an automatic lifting mechanism and driven by the automatic lifting mechanism to rise or fall so that the inlet and outlet centers of the induction heating furnace are located on the central axis of the bar, for induction heating of the bar passing through the furnace; and a feeding roller conveyor, which is mounted on one side of the automatic lifting mechanism via a support frame, for driving the bar to rotate around its central axis while moving forward along its axial direction into the induction heating furnace for uniform heating. The method and apparatus for uniform induction heating of bars of this invention are easy to operate and have a simple structure. The feeding roller conveyor allows the bar to rotate around its central axis while moving along its axial direction during induction heating, solving the problem of uneven heating of bars of different specifications during induction heating. It is applicable to all specifications of bars, has low cost, and a wide range of applications.

Description

Technical Field

[0001] This invention belongs to the technical field of material heating devices, and particularly relates to a method and device for uniform induction heating of rods. Background Technology

[0002] When heating bars in existing heating furnaces, the bars are usually placed directly into the furnace, which makes it difficult to achieve uniform heating and the surface of the bars is easily heated unevenly.

[0003] In addition, the rotation of the bar requires a complex mechanism, which is complicated to drive the rotation of the bar, is difficult to disassemble and assemble, and is costly. Summary of the Invention

[0004] Based on the shortcomings of the prior art, the technical problem solved by the present invention is to provide a method and apparatus for uniform induction heating of bars, which is easy to operate and has a simple structure. By using a feeding roller conveyor, the bar rotates around its central axis and travels along its axial direction during the induction heating process, thus solving the problem of uneven heating of bars of different specifications during the induction heating process.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] This invention provides a method for uniform induction heating of bars, comprising the following steps: determining the actual specifications of the bars to be heat-treated; calculating the required height for the induction heating furnace to rise or fall based on the bar specifications, so that the center of the inlet and outlet of the induction heating furnace is located on the central axis of the bar; feeding the bar via a feeding roller conveyor located below and supporting the bar, causing the bar to rotate around its central axis while moving forward along its axial direction, and then the bar enters the induction heating furnace for uniform heating.

[0007] Optionally, the feeding roller conveyor includes multiple V-shaped rollers spaced apart and located on a straight line along the central axis of the bar. The rotation direction of the V-shaped rollers is set at an angle to the central axis of the bar. The rotation of the V-shaped rollers causes the bar to move forward along the straight line along the V-shaped rollers and rotate around its central axis.

[0008] Optionally, the induction heating furnace rises or falls to a designated position with the automatic lifting mechanism of the induction furnace. There are multiple induction heating furnaces, which are alternately distributed with V-shaped rollers in the forward direction of the bar.

[0009] As described above, by aligning the center of the bar with the center of the induction heating furnace and by having the bar rotate around its axial direction while simultaneously traveling along its axial direction during induction heating, the problem of uneven heating of bars of different specifications during induction heating is solved. The bar uniform induction heating method and apparatus of this invention are applicable to all specifications of bars, and the overall structure is simple, low-cost, and widely applicable.

[0010] The present invention also provides a device for uniform induction heating of bars, comprising: an induction heating furnace, which is installed on an automatic lifting mechanism of the induction furnace and driven by the automatic lifting mechanism to rise or fall so that the inlet and outlet centers of the induction heating furnace are located on the central axis of the bar, for induction heating of the bar passing through the induction heating furnace; and a feeding roller conveyor, which is installed on one side of the automatic lifting mechanism of the induction furnace through a support frame, for driving the bar to rotate around its central axis and move forward along its axial direction into the induction heating furnace for uniform heating.

[0011] Optionally, there are multiple feeding roller conveyors, which are spaced apart along the forward direction of the bar. Each feeding roller conveyor includes a V-shaped roller located below the bar and supporting the bar, and a drive mechanism for driving the V-shaped roller to rotate.

[0012] Optionally, the number of induction heating furnaces is multiple, and they are alternately distributed with V-shaped rollers in the forward direction of the bar.

[0013] As described above, the bar is fed by rotating the V-shaped rollers, that is, it moves forward along the axial direction of the bar. The feeding rollers are at a certain angle to the transmission direction of the bar, which enables the bar to rotate. Thus, the bar can rotate around its axial direction while moving forward along its axial direction. The rotation of the V-shaped rollers can solve the problem of uneven heating of the bar during induction heating.

[0014] Furthermore, the automatic lifting mechanism of the induction furnace includes a furnace body mounting bracket connected to the top of the base frame via guide columns, a dual-output shaft servo motor installed in the middle of the base frame, a transmission shaft connected to the output shafts on both sides of the dual-output shaft servo motor via a second coupling, and a ball screw jack connected to the transmission shaft. The furnace body mounting bracket is fixed to the output end of the ball screw jack. The dual-output shaft servo motor drives the transmission shaft to rotate via the second coupling, and the transmission shaft drives the output end of the ball screw jack to rise or fall. The furnace body mounting bracket rises or falls to a specified height along with the output end of the ball screw jack.

[0015] As described above, the automatic lifting mechanism of the induction furnace ensures the adjustment of the furnace height, which is convenient and quick to adjust and easy to operate. The furnace height can be adjusted at any time according to the actual specifications of the bars, thereby enabling heat treatment of bars of different specifications and increasing the application range of this device.

[0016] Optionally, the drive mechanism includes a motor, a roller shaft connected to the output shaft of the motor via a first coupling, and a V-shaped roller coaxial with the roller shaft and fixed at the end of the roller shaft; the roller shaft is set at an angle to the central axis of the bar.

[0017] Optionally, the included angle between the roller and the central axis of the bar is 100°-130°.

[0018] As described above, the V-shaped rollers are driven to rotate by a motor and roller shaft. The bar placed within the V-shaped rollers exerts pressure on the V-shaped grooves of the rollers under its own weight. The reaction force of the rotating V-shaped rollers on the bar causes it to move forward while simultaneously rotating. Through this simple mechanical structure, the bar can move forward along its axial direction while rotating around its central axis. Furthermore, to accommodate bars of different specifications, V-shaped rollers of different sizes can be easily replaced to generate sufficient friction between the rollers and the bar to propel it forward and rotate, thus achieving uniform heating of bars of varying specifications.

[0019] Furthermore, the induction heating furnace includes a furnace body and an induction heating coil located inside the furnace body, and the center of the inlet and outlet of the induction heating furnace is located on the central axis of the induction heating coil.

[0020] As described above, the surface of the bar is rapidly heated to the quenching temperature by means of the current heating coil and water cooling to obtain a martensitic structure on the surface layer of the bar, thus completing the uniform heating of the bar.

[0021] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, the following detailed description is provided in conjunction with preferred embodiments and accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0023] Figure 1 This is a schematic diagram of the structure of the uniform induction heating device for rods according to the present invention;

[0024] Figure 2 This is a top view of the device for uniform induction heating of bars according to the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the induction heating furnace of the present invention;

[0026] Figure 4 This is a schematic diagram of the automatic lifting mechanism for the induction furnace of the present invention.

[0027] Among them, 10-feeding roller conveyor, 11-motor, 12-first coupling, 13-bearing, 14-roller shaft, 15-V-type roller, 20-induction heating furnace, 21-furnace body, 22-induction heating coil, 30-automatic lifting mechanism of induction furnace, 31-furnace body mounting frame, 32-guide column, 33-bottom frame, 34-ball screw jack, 35-second coupling, 36-drive shaft, 37-dual output shaft servo motor, 40-support frame. Detailed Implementation

[0028] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this specification. These embodiments illustrate the principles of the invention, and other aspects, features, and advantages of the invention will become apparent from this detailed description. In the accompanying drawings, the same or similar parts in different figures are indicated by the same reference numerals.

[0029] like Figures 1 to 4 As shown, the induction heating device for uniform induction heating of bars of the present invention mainly consists of a feeding roller conveyor 10, an induction heating furnace 20, and an automatic lifting mechanism 30 for the induction furnace. The induction heating furnace 20 is mounted on the automatic lifting mechanism 30 and is driven by the automatic lifting mechanism 30 to rise or fall, ensuring that the inlet and outlet centers of the induction heating furnace 20 are located on the central axis of the bar, for induction heating of the bar passing through the induction heating furnace 20. The feeding roller conveyor 10 is mounted on one side of the automatic lifting mechanism 30 via a support frame 40, for driving the bar to rotate around its central axis while moving forward along its axial direction into the induction heating furnace 20 for uniform heating.

[0030] The present invention comprises multiple feeding roller conveyors 10, which are spaced apart along the forward direction of the bar. Each feeding roller conveyor 10 mainly consists of a motor 11, a first coupling 12, a bearing 13, a roller shaft 14, and a V-shaped roller 15. The output shaft of the motor 11 is connected to the first coupling 12, and the other end of the first coupling 12 is connected to the roller shaft 14. The roller shaft 14 is rotatably mounted on a support frame 40 via the bearing 13. The V-shaped roller 15 is coaxial with the roller shaft 14 and is fixedly mounted at the end of the roller shaft 14 away from the first coupling 12. The V-shaped roller 15 is located below the bar and supports the bar. Multiple V-shaped rollers 15 are spaced apart and located on the straight line of the central axis of the bar. The roller shaft 14 is set at an angle to the central axis of the bar, that is, the roller shaft 14 and the transmission direction of the bar form an angle, and the angle between the roller shaft 14 and the central axis of the bar is 100°-130°. Under its own weight, the bar presses against the surfaces of the V-shaped groove on both sides of the V-shaped roller 15. The compressive friction between the sides of the V-shaped groove and the outer surface of the bar drives the bar forward axially and rotates. The rotation direction of the V-shaped roller 15, driven by the roller shaft 14, is set at an angle to the central axis of the bar. The force exerted by the V-shaped roller 15 on the bar is also at an angle to its central axis, thus applying a forward inclined force. The rotation of the V-shaped roller 15 causes the bar to move forward along the straight line containing the V-shaped roller 15 and rotate around its central axis. The multiple roller shafts 14 are parallel to each other, and all the V-shaped rollers 15 are located on the same straight line (the central axis of the bar). The rotation of the V-shaped roller 15 causes the bar to move forward along the straight line containing the V-shaped roller 15 and rotate.

[0031] The motor 11 drives the roller shaft 14 to rotate through the first coupling 12, which in turn drives the V-shaped roller 15 to rotate. The feeding roller 10 is at a certain angle to the transmission direction of the bar, which can realize that the bar rotates around its central axis while moving forward along its axial direction during the induction heating process, thus improving the uniformity of the bar heating.

[0032] The aforementioned motor 11, first coupling 12, and roller 14 constitute a drive mechanism to drive the rotating V-shaped roller 15 to rotate, causing the bar to rotate around its central axis while moving forward along its axial direction and passing through multiple induction heating furnaces 20 in sequence.

[0033] In this invention, multiple induction heating furnaces 20 are used, and they are alternately distributed with V-shaped rollers 15 in the forward direction of the bar. Each induction heating furnace 20 mainly includes a furnace body 21 and an induction heating coil 22. The induction heating coil 22 is installed inside the furnace body 21, and the center of the inlet and outlet of the induction heating furnace 20 is located on the central axis of the induction heating coil 22. The working principle of the induction heating furnace 20 of this invention is to utilize the principle of electromagnetic induction to generate a high-density induced current on the surface layer of the bar, rapidly heating it to an austenitic state, followed by rapid cooling to obtain a martensitic structure. The bar enters the induction heating coil 22 through the feeding roller 10. Under the action of the magnetic field, an induced current with the same frequency but opposite direction to that of the induction heating coil 22 is generated inside the bar. Since the induced current forms a closed loop (called an eddy current) along the surface of the bar, this eddy current converts electrical energy into heat energy, rapidly heating the surface of the bar. The eddy current is distributed on the surface of the bar, and almost no current flows inside the bar. The surface of the bar is rapidly heated to the quenching temperature by the current heating effect. The induction heating coil 22 is made of copper tubing and contains cooling water. When the surface of the bar is heated to a certain temperature inside the induction heating coil 22, it is immediately cooled with water, so that the surface layer of the bar acquires a martensitic structure.

[0034] The automatic lifting mechanism 30 for induction furnace of the present invention mainly consists of a furnace body mounting frame 31, guide columns 32, a base frame 33, a ball screw jack 34, a second coupling 35, a drive shaft 36, and a dual-output shaft servo motor 37. The base frame 33 is placed on the ground, the bottom of the guide column 32 is slidably connected to the base frame 33 (for guiding purposes), the top of the guide column 32 is connected to the furnace body mounting frame 31, the dual-output shaft servo motor 37 is installed in the middle of the base frame 33, the two drive shafts 36 are connected to the output shafts on both sides of the dual-output shaft servo motor 37 through the second coupling 35, and the other end of the drive shaft 36 is connected to the ball screw jack 34 through a coupling. The furnace body mounting frame 31 is fixed to the output end of the ball screw jack 34. The dual-output shaft servo motor 37 drives the transmission shaft 36 to rotate through the second coupling 35, so that the output end of the ball screw jack 34 can rise or fall. The furnace body mounting frame 31 rises or falls to a specified height along with the output end of the ball screw jack 34, thereby driving the induction heating furnace 20 to rise and fall.

[0035] The induction heating furnace 20 is mounted on the furnace body mounting frame 31, and is raised or lowered by the induction furnace automatic lifting mechanism 30. Depending on the actual size of the bar being processed, the induction heating furnace 20 can rise or fall to a specified height, ensuring that the center position of the bar is always concentric with the center position of the inlet and outlet of the induction heating furnace 20, thus improving the uniformity of induction heating for bars of different specifications.

[0036] like Figure 2As shown, the transmission direction of the bar is from induction heating furnace No. 1 to induction heating furnace No. 6. Only a portion of the number of induction heating furnaces 20 is shown in the figure (to indicate that there are multiple induction heating furnaces). In a specific embodiment, there are twenty induction heating furnaces 20 used for heating and eighteen induction heating furnaces 20 used for heat preservation. The length of the bar is approximately 10 meters and the diameter of the bar is 15-50 mm. The bar rotates and moves forward by relying on the friction between the surface of the bar and the V-shaped roller 15.

[0037] Based on the above-mentioned induction heating device, the method for uniform induction heating of bars according to the present invention includes the following steps:

[0038] S1. In the initial state, the center of the bar to be heated may not be concentric with the center of the inlet and outlet of the induction heating furnace 20. Determine the actual specifications of the bar to be heated.

[0039] S2. Calculate the required height for the induction heating furnace 20 to rise or fall according to the specifications of the bar. The induction heating furnace 20 rises or falls to the designated position with the automatic lifting mechanism 30 of the induction furnace, so that the center of the inlet and outlet of the induction heating furnace 20 is located on the central axis of the bar, thereby ensuring that the center of the heated bar is concentric with the center of the inlet and outlet of the induction heating furnace 20.

[0040] S3. After the center of the bar to be heat-treated is concentric with the inlet and outlet center of the induction heating furnace 20, the feeding roller 10 located below the bar and supporting the bar will drive the bar to rotate around its central axis and move forward along its axial direction. Then the bar enters the induction heating furnace 20 for uniform heating.

[0041] The above description is merely a preferred embodiment of the present invention, and should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A device for uniform induction heating of bars, characterized in that, include: An induction heating furnace is installed on an automatic lifting mechanism for induction furnaces and is driven by the automatic lifting mechanism to rise or fall so that the inlet and outlet centers of the induction heating furnace are located on the central axis of the bar material, for induction heating of the bar material passing through the induction heating furnace. The feeding roller conveyor is installed on one side of the automatic lifting mechanism of the induction furnace via a support frame. It is used to drive the bar to rotate around its central axis and move forward along its axial direction into the induction heating furnace for uniform heating. The number of feeding roller tracks is multiple and they are distributed at intervals along the forward direction of the bar. Each feeding roller track includes a V-shaped roller located below the bar and supporting the bar, and a drive mechanism for driving the V-shaped roller to rotate. There are multiple induction heating furnaces, which are alternately distributed with V-shaped rollers in the forward direction of the bar. The automatic lifting mechanism of the induction furnace includes a furnace body mounting bracket connected to the top of the base frame via a guide column, a dual-output shaft servo motor installed in the middle of the base frame, a transmission shaft connected to the output shafts on both sides of the dual-output shaft servo motor via a second coupling, and a ball screw jack connected to the transmission shaft. The furnace body mounting bracket is fixed to the output end of the ball screw jack. The dual-output shaft servo motor drives the transmission shaft to rotate through the second coupling. The transmission shaft drives the output end of the ball screw jack to rise or fall. The furnace body mounting frame rises or falls to a specified height along with the output end of the ball screw jack. The drive mechanism includes a motor, a roller shaft connected to the output shaft of the motor via a first coupling, and a V-shaped roller coaxial with the roller shaft and fixed at the end of the roller shaft; the roller shaft is set at an angle to the central axis of the bar. The method of using the uniform induction heating device for bars includes the following steps: Determine the actual specifications of the bars to be heat-treated; Calculate the required height for the induction heating furnace to rise or fall based on the specifications of the bar stock, so that the center of the induction heating furnace inlet and outlet is located on the central axis of the bar stock. The feeding roller conveyor located below and supporting the bar feeds the bar, causing it to rotate around its central axis and move forward along its axial direction. The bar then enters the induction heating furnace for uniform heating.

2. The uniform induction heating device for rods as described in claim 1, characterized in that, The angle between the roller and the central axis of the bar is 100°-130°.

3. The device for uniform induction heating of bars as described in claim 1, characterized in that, The induction heating furnace includes a furnace body and an induction heating coil located inside the furnace body. The center of the inlet and outlet of the induction heating furnace is located on the central axis of the induction heating coil.

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