JP2009233706A - Method and apparatus for induction-heating of billet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for induction-heating with which in the method and the apparatus for induction-heating of a billet for forging by heating a columnar billet 13, especially the columnar billet 13 having large weight and diameter, a scratch generated in a billet conveying way in the induction-heating apparatus 1 is restrained and diffusion-joining of both billets 13 is restrained. <P>SOLUTION: In the inner part of the billet heater 18 including an induction-heating coil 24, an upgrade conveying way is disposed and the columnar billet to be heated (for example, the columnar billet 13) is supplied as sideways to the billet-heater 18 and the billet 13 is made to move forward towards an outlet from an inlet, while automatically rotating the billet 13 by an aligned state sideways, and heated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating apparatus before forging in a forging line for automobile parts, bolts, nuts and the like.

  In a forging line for automobile parts, bolts, nuts, etc., it is necessary to heat a cylindrical billet as a material before forging. Normally, when heating a cylindrical billet, as shown in FIG. 7, a highly wear-resistant rail 12 or the like is disposed in a solenoid-type induction heating coil 24 connected to a power source 25, and the cylindrical billet 13. Is continuously extruded by a supply roller 23 which is a billet supply device, whereby the billet 13 is supplied into the induction heating device 2 and heated while sliding in the axial direction. In other words, the billet 13 moves in the induction heating device 2 while being pushed by the billet 13 continuously supplied thereafter. This heating method is a highly efficient heating method because the magnetic coupling between the induction heating coil 24 and the cylindrical billet 13 is good.

  Further, when the billet 13 is heated, heating the billet 13 so that the temperature distribution in the billet 13 is uniform is an important issue in suppressing the occurrence of defective products in the forged product. In the method shown in FIG. 7, the cylindrical billet 13 passes through the induction heating device 2 while the orientation of the columnar billet 13 is constant, and thus there is a problem that uneven heating occurs on the upper and lower surfaces of the billet.

A method for solving this problem has been devised (see, for example, Patent Document 1).
According to the method described in Patent Document 1, as shown in FIG. 4, the cylindrical billet 13 and the supply roller 23 which is a billet supply device are continuously supplied into the induction heating device 2. Here, a cylindrical rotating roller 22 is provided for rotating the billet in a direction perpendicular to the conveying direction so as to prevent uneven heating, that is, to make the temperature distribution in the billet uniform. ing. Further, the billet 13 guided into the induction heating device 2 is pushed by the billet 13 continuously supplied from the supply roller 23 together with the action of the cylindrical conveying roller 21 and is conveyed through the induction heating device 2. Go.

  FIG. 5A shows an enlarged side view of the rotating roller 22 and the conveying roller 21, and FIG. 5B shows an enlarged plan view. The arrows shown in the figure indicate the rotation directions of the rotation roller 22 and the conveyance roller 21.

  FIG. 6 shows a front view of the billet 13 extruded from the induction heating device 2.

By the above method, the columnar billet 13 heated in the induction heating device 2 is heated uniformly, and a method has been proposed that can suppress casting defects caused by heating unevenness.
JP 2001-129610 A

  However, in the method described in FIG. 7, in addition to uneven heating, the billet 13 is thicker than 80 mm in diameter, and if the unit weight becomes large, the friction with the rail 12 increases, Sliding scratches generated on the rail 12 and short life of the rail 12 are problematic.

  Furthermore, since the billet 13 is conveyed by the inside of the induction heating device 2 while being pushed by the supply roller 23 by the continuously supplied billet 13, the force applied to the contact surface of the adjacent billet is increased. Therefore, the problem that billets 13 are joined by the diffusion joining phenomenon frequently occurs. By joining the billets 13 to each other, defective billets that are not suitable for forging are generated, so that the yield in forged product production is lowered.

  Moreover, in the method described in Patent Document 1, the same problem as described above occurs, and furthermore, since the conveying roller 21 and the rotating roller 22 are installed in the induction heating device 2, the temperature in the device can be set high. Can not. Although depending on the material of the roller, for example, when the billet 13 to be heated is aluminum, the melting point is about 660 ° C., so the method described in Patent Document 1 is considered applicable.

  However, when the billet 13 to be heated is iron, the forging temperature is as high as about 1250 ° C., so it is difficult to install a roller that can withstand use under such a high temperature condition.

  Accordingly, the present invention has been made to solve the above-described problems, and in a billet induction heating method and apparatus for forging for heating a cylindrical billet, particularly a cylindrical billet having a large weight and diameter, An object of the present invention is to provide an induction heating method and apparatus that suppresses sliding flaws that occur in the billet conveyance path and suppresses diffusion bonding between the billets 13.

  In order to solve the above-described problem, an induction heating method according to the invention described in claim 1 is configured such that an upwardly inclined conveyance path is disposed inside a billet heater 18 having a built-in induction heating coil 24, and a cylindrical object to be heated ( For example, a cylindrical billet 13) is supplied laterally to the billet heater 18, and the billet 13 is advanced and heated from the inlet toward the outlet while rotating in the horizontal orientation.

  The induction heating method according to the second aspect of the invention is characterized in that the billet 13 is pushed so as to be impacted and roll in the billet heater 18.

  In the induction heating apparatus according to the third aspect of the present invention, an upwardly inclined conveyance path is disposed inside the billet heater 18 including the induction heating coil 24, and the columnar billet 13 rotates sideways while rotating on the conveyance path. A guide plate that can move in a direction is installed, and a supply device 11 that sequentially feeds the billet 13 while rotating the billet 13 on the guide plate is installed at the billet heater inlet.

  Here, as the guide plate, for example, a rail-shaped transport rail 12 or a plate-shaped transport plate formed of a heat resistant material is used. The supply device 11 is formed by, for example, a pusher body 16 that presses the billet 13 slidably installed in the drive device 17.

  In the induction heating device according to the fourth aspect of the present invention, the guide plate in the induction heating coil is inclined upward with respect to the conveying direction of the columnar billet 13, and the columnar billet 13 is on the supply device 11 side. It is characterized in that it is installed at an angle that rotates and returns to the position. Preferably, the guide plate is installed on an ascending slope with an installation angle in the range of 0 to 15 degrees.

  The induction heating device according to the fifth aspect of the invention is a supply device configured such that the length by which the cylindrical billet 13 is pushed out to the guide plate by the supply device 11 is not less than the diameter of the billet 13. 11 is provided.

  Since the cylindrical billet 13, particularly a large cylindrical billet 13 having a diameter exceeding 80 mm, is conveyed while rolling on the conveyance rail 12 by the induction heating method of the present invention, the sliding scratches generated on the conveyance rail 12 are suppressed. Furthermore, since the position where the billets 13 are in contact with each other continues to change due to the rolling of the billets 13, it is possible to suppress the joining of the billets 13 due to the diffusion bonding phenomenon.

  By suppressing the occurrence of sliding flaws on the transport rail 12, the maintenance cost of the induction heating device 1 is reduced, and a forged product can be produced at a lower cost. Moreover, since the amount of generation of defective billets is reduced by suppressing the joining of the billets 13, the production efficiency is increased, and furthermore, a higher quality forged product can be produced.

  Since the transport rail 12 is inclined upward in the transport direction of the billet 13, the billet 13 is transported in a state where it is filled in the billet heater 18, so that a sufficient heating time can be obtained.

  Since the supply device 11 for supplying the billet 13 into the billet heater 18 is a pusher type constituted by the pusher body 16 and the drive device 17, the billet 13 is supplied while rolling into the billet heater 18 so as to be driven out. It became so.

  Furthermore, the amount of extrusion by the pusher body 16 is made larger than the diameter of the billet 13, so that the ascending conveyance rail 12 rises, and the billet 13 falls to the supply side of the conveyance rail 12 while rolling due to gravity.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a schematic view when a cylindrical billet 13 is supplied to the induction heating apparatus 1 of the present invention. The induction heating device 1 of the present invention includes a billet heater 18 having an induction heating coil 24 arranged to be wound around a conveyance rail 12 that is a conveyance path of the billet 13, and energizes the induction heating coil 24. A power supply 25 is connected.

  The supply device 11 for supplying the billet 13 into the billet heater 18 includes a drive device 17 for driving the pusher body 16 on a pusher body 16 that pushes the billet 13 while rotating the billet 13.

  Furthermore, the induction heating apparatus 1 is installed such that the conveyance path of the billet 13 has an installation angle 15 with respect to the horizontal plane 14.

Below, the process of heating the cylindrical billet 13 by the induction heating apparatus 1 of the present invention will be described.
The cylindrical billet 13 is supplied in order one by one in front of the pusher body 16 in a state where the rolling direction coincides with the transport direction, and is transported in an upward gradient while being rolled by the pusher body 16 pushed out by the driving device 17. Go up the rail 12.

  Usually, since the billet 13 is continuously supplied into the billet heater 18 by the supply device 11 during heating, the billet heater 18 is filled with a plurality of billets 13. Therefore, as the pusher body 16 is pushed out, the plurality of billets 13 in the billet heater 18 are rotated up the transport rail 12.

  Then, the billet 13 closest to the outlet of the billet heater 18 is pushed out and supplied to a forging processing apparatus (not shown).

  Basically, one billet 13 is supplied into the billet heater 18 by one sliding of the pusher body 16, and one billet is discharged at the same time. However, the number of billets 13 supplied and discharged can be changed based on the relationship between the billet 13 heating time and the amount of processing per hour.

  FIG. 2 shows a state when the billet 13 closest to the discharge port filled in the billet heater 18 is pushed out. FIG. 3 shows a front view of the billet 13 discharged from the discharge port. The billet 13 closest to the discharge port rolls and is supplied to a forging processing device (not shown), but the remaining billet 13 rolls down on the slope of the transport rail 12 due to gravity, and on the supply side of the billet heater 18 A new billet 13 is supplied.

  Here, a new billet 13 is sequentially supplied to the supply device 11 by a conveyance device (not shown). At this time, the billet 13 supplied into the billet heater 18 is returned to the supply device 11 due to the gradient of the conveyance rail 12. A backflow prevention mechanism 26 is provided so as not to be present. In this embodiment, the backflow prevention mechanism 26 is a step provided on the transport rail 12. However, there are many other methods such as providing a knob-like object on the transport rail 12, and the backflow prevention mechanism 26 is limited to the mechanism shown in FIG. Absent.

  By repeating the above steps, the billet 13 is gradually carried above the conveyance rail 12 in the conveyance direction while repeating the forward rotation that goes up and down the conveyance rail 12. At this time, since the billet 13 repeatedly performs forward or backward rotational movement, the location of contact with the adjacent billet 13 or the conveyance rail 12 changes, so that the occurrence of sliding flaws and diffusion bonding phenomenon is suppressed. Has been.

  In particular, the billet 13 does not stagnate near the outlet of the billet heater 18 by making the extrusion length of the billet 13 larger than the diameter of the billet 13. Therefore, the temperature of the billet 13 decreases due to heat dissipation, and the quality of the forged product decreases. That is, the billet 13 is always controlled in the billet heater 18 at an optimum temperature for forging, and it is possible to eliminate the cause of the quality deterioration of the forged product due to the temperature drop.

  Further, by setting the length of the billet 13 to be pushed out by the pusher body 16 to be equal to or larger than the diameter of the billet 13, the billet 13 can be moved backward in the transport direction. For example, if the extrusion length of the billet 13 is doubled with respect to the billet diameter, the plurality of billets 13 in the billet heater 18 have an upward slope of the conveyance rail 12 that is twice as long as the billet diameter. It will go up while going forward.

  The billet 13 closest to the discharge port of the billet heater 18 is discharged and carried to a forging processing device (not shown), but the remaining billet 13 in the billet heater 18 causes the billet heater to be inclined due to its own weight. 18 Turns downward on the supply port side. Here, a new billet 13 is supplied to the supply side. However, only one billet 13 is supplied, and a plurality of billets 13 in the billet heater 18 have a lowering space for one billet. There will be. That is, the billet 13 in the billet heater 18 moves up the gradient of the conveyance rail 12 while rotating the length of two billets forward, and rolls down the conveyance rail 12 while rotating the length of one billet backward. It becomes.

  Even if the extrusion length of the billet 13 is equal to the billet diameter, the plurality of billets 13 in the billet heater 18 are conveyed while being rotated forward, so that it is possible to suppress the occurrence of the diffusion bonding phenomenon. However, by setting the launch length to a length larger than the billet diameter, the billet 13 in the billet heater 18 performs the backward movement, and it is possible to further suppress the occurrence of the diffusion bonding phenomenon.

  Further, in order to convey the billet 13 while performing forward and backward movements, the conveyance rail 12 needs to be configured to have an installation angle 15 with respect to the horizontal plane. The installation angle 15 differs depending on the diameter, weight and material of the billet 13, the length of the conveying path in the billet heater 18, the friction coefficient between the billet 13 and the guide plate, etc., but at least the billet 13 rotates. Therefore, it is desirable that the angle be an upward gradient that returns to the supply device 11 side and that the value is smaller than approximately 15 degrees.

  If the installation angle 15 is reduced, the frictional resistance between the billet 13 and the lower guide plate increases relative to the frictional resistance between the adjacent billets 13, so that the rotational force during billet movement increases, and the contact location between the billets 13 is increased. Since the change and the pressure at the contact point are also reduced, the effect of suppressing the diffusion bonding phenomenon is improved.

  However, there is a lower limit for the installation angle 15 because the rolling time required during the backward movement of the billet 13 needs to be designed to be equal to or less than the discharge cycle of the billet 13. That is, when the billet 13 is discharged every t seconds, it is necessary to design the time for the backward motion to be less than t seconds. If the installation angle 15 is too small, the time for the backward motion is required. Since it becomes long, the lower limit of the installation angle 15 exists.

  As described above, the installation angle 15 is determined to be an optimum value based on the length and heating speed of the conveyance path of the induction heating device 1, the diameter, weight, material of the billet 13, the friction coefficient between the billet 13 and the guide plate, and the like. It is possible to design a highly efficient induction heating apparatus 1 with a proper installation angle 15.

  In addition, the induction heating method and apparatus of the present invention suppresses sliding flaws on the transport rail 12 and more particularly when heating a billet 13 having a diameter greater than 80 mm or a large unit weight, as compared with the conventional heating method. It has a remarkable effect on suppressing diffusion bonding.

  As described above, by the induction heating method and apparatus of the present invention, in the heating of the columnar billet 13, particularly the columnar billet 13 having a large weight and diameter, the sliding scratches generated in the billet conveyance path in the induction heating device 1 are suppressed, It became possible to suppress the diffusion bonding between the billets 13 and realized the induction heating of the cylindrical billet 13 with higher efficiency, thereby realizing high quality and low cost of the forged product.

It is the schematic of the induction heating apparatus of this invention. It is the schematic of the induction heating apparatus of this invention. It is a front schematic diagram of the induction heating device of the present invention. It is the schematic of a conventional induction heating apparatus. It is an enlarged view of the vicinity of the conveyance roller and the rotating roller of the conventional induction heating apparatus. It is a front schematic diagram of a conventional induction heating apparatus. It is the schematic of a conventional induction heating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Induction heating apparatus 11 Supply apparatus 12 Conveying rail 13 Billet 14 Horizontal surface 15 Installation angle 16 Pusher body 17 Drive apparatus 18 Billet heater 24 Induction heating coil 25 Power supply 26 Backflow prevention mechanism

Claims (5)

  An upwardly inclined conveyance path is arranged inside the billet heater with a built-in induction heating coil, a cylindrical heated body is supplied laterally to the billet heater, and the heated body is rotated side by side in an aligned state. An induction heating method characterized in that heating is performed by moving forward from the inlet toward the outlet.   The induction heating method according to claim 1, wherein the heated object is pushed so as to roll in the billet heater.   An upwardly inclined conveying path is arranged inside a billet heater having a built-in induction heating coil, and a guide plate is installed in the conveying path so that a cylindrical heated body can move laterally while rotating. An induction heating apparatus characterized in that a supply device for sequentially supplying the heated body while rotating is installed at the billet heater inlet.   The said guide plate is installed in the angle which the column-shaped to-be-heated body rotates to the said supply apparatus side, and is returned by the upward gradient with respect to the conveyance direction of the said to-be-heated column-shaped body. The induction heating apparatus described.   4. A supply device configured so that a length by which the columnar heated body is pushed into the induction heating coil by the supply device is not less than a diameter of the heated body. Or the induction heating apparatus of Claim 4.