JPS6112633B2 - - Google Patents

Description

Detailed Description of the Invention The present invention is an induction heating device in which a heating coil for temperature raising and a heating coil for soaking are provided separately, in which the billet is reversed from the heating coil for heating to the heating coil for soaking. I decided to send it.

Conventionally, billet heaters are sometimes provided with separate heating coils for raising the temperature and heating coils for equalizing heat in order to prevent billets from welding together. Figures 1a and 1b show an example. C ₁ is a heating coil for raising the temperature, and C ₂ is a heating coil for soaking, which are separately arranged on the feeding path of the billet 1.
The inlet side of the heating coil C ₂ for soaking is located slightly below the outlet side of the heating coil C ₁ for temperature raising, and is inclined so that the inlet side is upward and the outlet side is downward. Reference numeral 5 denotes a J-shaped stopper, one end of which is connected to the tip of the rod 61 of the cylinder 6, the other end protrudes slightly inward from the outlet side of the heating coil _C2 for equalizing heat, and its end surface is connected to the end of the rod 61 of the cylinder 6. It is directed toward the tip end face of billet 1 sent to coil _C2 . The stopper 5 is rotatable about a 0 point approximately in the center of the vertical portion as a fulcrum. Therefore, by driving the cylinder 6 and moving the rod 61 forward from the state shown in _FIG .
is released from the other end of the stopper 5 and can be discharged from the soaking heating coil _C2 . Thereafter, by retracting the rod 61, the billet to be sent next is stopped at the other end of the stopper by the soaking heating coil _C2 . In addition, in FIG. 1b, 4 is the fireproof lining of the heating coil _C1 for temperature raising.

In such a configuration, the billet 1 is continuously fed into the heating coil C ₁ for heating by means of a feeding means such as a pinch roller 2, with the longitudinal direction being the feeding direction _. The front and rear billets are pushed along the provided skit rail 3 with their end surfaces in contact with each other. Billet 1
is heated to a predetermined temperature while passing through the temperature-raising heating coil C ₁ , and descends from the exit side of the temperature-raising heating coil C ₁ on the inclined skid rail 31 due to its own weight. The lowering is stopped, and uniform heating is performed over the entire cross section within the uniform heating coil _C2 . When the billet 1 has been uniformly heated over its entire cross section after a predetermined period of time has elapsed, the rod 61 of the cylinder 6 moves forward and is locked by the stopper 5 that had previously locked the billet 1 on the exit side of the heating coil for uniform heating. is unraveled and the billet is discharged from the soaking heating coil _C2 . Heating coil for uniform heating
The uniform heating over the entire cross section of the billet at C ₂ is
Usually, the succeeding billet 1 is the heating coil C ₁ for temperature increase.
Since this is completed before the billet 1 descends from the top, by retracting the rod 61 after discharging the preceding billet 1, the stopper 5 returns to its original position and waits for the descending of the following billet 1. However, in such a conventional method, the billet 1 is fed in the longitudinal direction in both the heating coil C ₁ for temperature raising and the heating coil C ₂ for soaking, so for example, if the billet 1 is fed in the longitudinal direction, for example, if the billet is 70mmφ or more for a round material, or more than 70mmφ for a square material. In the case of large billets such as 65 mm square or more, when the temperature rises in the heating coil C ₁ , the temperature rises due to the effects of air convection in the furnace and the skid rail 3 installed at the bottom through which cooling water is passed. The temperature rise in the upper UF of the billet is greater than that in the lower DF, resulting in a considerable temperature difference near the exit. In order to prevent such a temperature difference within the heating coil _C1 for heating, some devices for large billets are equipped with a skid rail 32 on the upper furnace wall near the outlet to allow cooling water to flow through it. There are some things. but,
Place the skit rail 32 on top of the billet.
If the UFs are placed in contact with each other, this will impede billet feeding, so it is necessary to create a structure that leaves a gap between them.In addition, in order to obtain effective heat uniformity, the number of upper skid rails 32 must be increased. If the billet is heated up and cooled, it will not be effective, and even then it is difficult to achieve uniform heating on the top and bottom sides of the billet.
Even if the above configuration is added, a billet with a temperature difference between the upper UF and the lower DF as exemplified by the cross-sectional temperature curve in Figure 2a will be fed into the soaking heating coil _C2 . The current situation is that
Moreover, it is clear that this method has very poor thermal efficiency. Furthermore, the same side of the billet 1 that was in contact with the skitt rail 3 in the heating coil C ₁ for temperature raising comes into contact with the skid rail 31 of the heating coil C ₂ for equalizing heat, through which cooling water is passed. Therefore, even if the uniform heating coil _C2 is used to uniformly heat the billet over the entire cross section, the lower DF as shown in the cross-sectional temperature curve in Figure 2b.
Only low temperature characteristics can be obtained. A billet with such a temperature gradient has uneven deformability, which will not only cause problems in the next forging process, but also when heat treatment such as refining and quenching is performed using high temperatures after forging. This will have a significant negative impact.

The present invention attempts to solve the above-mentioned drawbacks of conventional billet heaters by providing a reversing transfer device for reversing the billet between the heating coil for temperature raising and the heating coil for soaking. be.

The present invention will be explained according to the embodiments shown in FIGS. 3 to 6.

In FIGS. 3a and 3b, billet 1 is continuously fed by feeder 8 in the direction of arrow a.
Reference numeral 9a is a cylinder, and the tip of the rod 91a is provided so as to face the end surface of the billet 1 located at the forefront of the feeder 8. cylinder 9a
As the rod 91a is driven forward, the billets at the forefront of the feeder 8 are pushed one by one to the front surface of the inlet of the heating coil _C1 for heating. 9b is also a cylinder, and the axis of the rod 91b of the cylinder 9b is on the extension of the axis of the temperature-raising heating coil _C1 , and a two-pronged push rod 92b is attached at the tip so that the billet is fed evenly on the left and right sides. Fixed. As the rod 91b moves forward, the billet 1, which has been sent to the front surface of the inlet of the temperature-raising heating coil _C1 via the push rod 92b, is pushed to the temperature-raising heating coil _C1 with its longitudinal direction being the feeding direction. The length of the heating coil _C1 is set so that the billet 1 sent to the inlet side can be heated to a predetermined temperature while being pushed by the successive billets and reaching the outlet side. is set in relation to the specifications. 3 is a skit rail, and 4 is a fireproof lining.

_C2 is a heating coil for soaking, and is set to a size that can sufficiently accommodate and quantify one billet 1 in the longitudinal direction when the billet 1 is fed in a direction perpendicular to the longitudinal direction. In _this embodiment _, unlike the conventional example shown in FIG. placed parallel to the line. Reference numeral 7 denotes a reversal transfer device, which includes a rotating shaft 72 that rotates by driving a drive source 71;
A support arm 7 whose end is pivotally connected to the rotating shaft 72 and whose other end is fixed to the back surface of a U-shaped billet receiver 74.
It consists of 3,73. The rotating shaft 72 is arranged parallel to the axis of the heating coil C ₂ at a position approximately halfway between the end surface of the exit side of the heating coil C ₁ for temperature raising and the extension line of the feed path of the heating coil C ₂ for soaking. , and is arranged on a surface parallel to the passageway, below the lower surface on the outlet side of the passageway of the heating coil _C1 . Therefore, by setting the dimensions of the U-shaped billet receiver 74 and the lengths of the supporting arms 73, 73 as specified, the temperature of the billet receiver 74 can be increased by clockwise or counterclockwise rotation of the rotating shaft 72. It is possible to position it from the outer lower side of the outlet side of the heating coil C ₁ for heating to near the inlet side of the heating coil C ₂ for soaking, or vice versa. The inner wall of the billet receiver 74 has protrusions 75a, 75b and 75 of the same height as shown in FIG. 3b.
c is provided. This is done by keeping the surface of the billet 1 in contact with the inner wall of the billet receiver as small as possible, so that the billet is transferred from the heating coil _C1 for temperature increase into the billet receiver 74, and then from the inside of the billet receiver 74 to the heating coil _C2 for uniform heating. This is to make it easier to move smoothly and to reduce the contact area to prevent temperature drop.
5a and 75b are preferably arranged at angles different from each other by 90°. The protrusion 75c may be provided in any shape and angle as long as it reduces the contact surface. 9c is a cylinder, and the heating coil for uniform heating of the billet 1 is accommodated in the billet receiver 74 with the tip end face of the rod 91c reversed to the S position.
It is arranged so as to face the opposite end face on the opposite side of C ₂ . Note that 79 is a stopper that prevents the billet 1 from falling when the billet receiver 74 containing the billet 1 reaches the S position.

Before the billet 1 is discharged from the heating coil C ₁ for heating, the billet receiver 74 is at the R position near the lower side of the exit side of the heating coil C ₁ for heating, and its opening is heated as shown in FIG. 3b. It is on standby with the heating coil _C1 facing the outlet side. When the billet 1 heated to a predetermined temperature within the heating coil C ₁ is discharged from the heating coil C ₁ and stored in the billet receiver 74, the drive source 71 is driven and the rotating shaft 72 rotates clockwise. The billet receiver 74 is transferred from the R position to the S position, but the third
As shown in Figure b, when the billet 1 is accommodated in the billet receiver 74 in the R position, the billet 1
The surface 1A of the temperature increasing heating coil _C1 that was in contact with the skid rail 3 comes into contact with the protrusion 75a of the billet receiver 74, but by the time it reaches the S position, the inner wall with the protrusion 75a has become The billet 1 in the billet receiver 74, which has been reversed to the upper side in relation to the heating coil _C2 and reached the S position by advancing the rod 91c of the cylinder 9c, contacts the skid rail ₃ with the heating coil C1 for heating. It is inserted into the uniform heating coil _C2 and placed in such a state that the unfinished surface 1b is in contact with the skid rail 3'.
Therefore, when the billet 1 is discharged from the temperature increasing heating coil _C1 , the upper UF of the heated billet 1 reaches the skid rail 3' of the soaking heating coil _C2 as shown in the cross-sectional temperature curve shown in Fig. 2a. The temperature increase was suppressed by contacting the lower DF, which was kept at a low temperature.
On the contrary, the temperature rise is accelerated by the thermal influence of air convection in the furnace, and after a predetermined soaking time, a cross-sectional temperature curve as shown in Figure 3d is obtained, and the billet is heated over the entire cross-section. It is heated uniformly without any temperature gradient and is discharged from the heating coil C ₂ for soaking. After the billet 1 is sent to the heating coil C ₂ for soaking, the billet receiver 74 is returned to the R position by counterclockwise rotation of the rotating shaft 72 driven by the rotary drive source 71, and the billet receiver 74 is returned to the R position by the counterclockwise rotation of the rotating shaft 72 driven by the rotary drive source 71. Wait for subsequent billet 1 from coil C ₁ . Thereafter, the reversal transfer of the billet 1 from the heating coil C ₁ for temperature raising to the heating coil C ₂ for soaking the billet 1 by the reversal transfer device 7 is continued in the same manner.

In the above embodiment, the billet 1 discharged from the heating coil C ₁ is transferred to the heating coil C ₁
An example has been described in which the billet receiver 74 placed near the lower side of the outlet is used to reverse and transfer the billet. However, a clamper is provided in place of the billet receiver 74, and the billet that has reached the vicinity of the outlet is gripped by the clamper. It may also be reversely transferred to the heating coil _C2 for soaking. The clamper is particularly suitable when the billet is a round bar material that easily rolls. An example is shown in FIG.

C ₁ is a heating coil for temperature increase, and the extension line of the axis of heating coil C ₂ for soaking (not shown) is on the same plane as that of heating coil C ₁ for temperature increase, and the exit of heating coil C ₁ for temperature increase They intersect perpendicularly at one point on the outside that extends a predetermined amount from the side. 72 is a heating coil for heating on the same plane as the plane containing the axes of both heating coils.
A rotating shaft is disposed at a predetermined position between both heating coils so as to be orthogonal to the axis of C ₁ , and its bearing 76 is fixed to a base 77 . On the right end surface of the base 77 in FIG. 4, there is a rod 91d of the cylinder 9d.
The tip of the cylinder 9d is fixed, and as the rod 91d of the cylinder 9d advances and retreats, the base 77 moves along the slide bar 78 toward the exit of the heating coil C ₁ for temperature increase or the entrance direction of the heating coil C ₂ for uniform heating. It is possible to slide to As in the first embodiment, one end of a support arm 73 having a predetermined length is pivotally attached to the rotating shaft 72, and the clamper 10 is fixed to the other end of the support arm 73. By rotating the rotating shaft 72 approximately 180 degrees with the base 77 positioned on the right side of the slide bar 78 in the figure, the clamper 10 is moved from near the outlet of the temperature increasing heating coil C ₁ to the soaking heating coil C _{2 .} It is possible to displace it near the entrance. The lower finger 101 of the clamper 10 is fixed and set so that it can be positioned on the same horizontal plane level as the skid rail 3 of the heating coil _C1 for temperature increase. The upper finger 102 is a movable finger, and a predetermined position at the rear end is pin-coupled to a predetermined position at the base of the clamper 10.

Attach one end of the cylinder 9e to a predetermined point on the support arm 73,
The cylinder 9e is attached to a predetermined point of the protrusion 103 formed as one body above the rear end of the upper finger 102.
The tips of the rods 91e are connected with pins.
Move the rod 91e backward and move the movable finger 10.
2 is rotated outward by a predetermined amount, the distance between the inner surfaces of the tips of the fingers 101 and 102 is larger than the diameter of the billet 1, but the distance between the outer surfaces of the fingers 101 and 102 is larger than the diameter of the billet ₁ . After making sure that the rod 91d of the cylinder 9d is smaller than the passage diameter, the rod 91d of the cylinder 9d is moved forward to send the base 77 from the right end of the slide bar 78 in the direction of the heating coil _C1 for heating the finger 10.
1, 102 is inserted into the heating coil C ₁ and waits for the arrival of the billet 1 that is being pushed through the heating coil C ₁ for heating. When the billet reaches the exit side, the cylinder 9e is driven by a detection signal or the like to advance the rod 91e, and the fingers 101 and 102 grip the billet 1.
Then, the cylinder 9d is driven to move the rod 91d backward. When the base 77 comes to the right end of the slide bar 78, the fingers 101 and 102 escape from the exit side of the temperature increasing heating coil _C1 . At that point, the rotating shaft 72 is operated by a drive source (not shown).
The clamper is rotated 180 degrees, the clamper is reversed 180 degrees, the movable finger 102 is rotated outward to release the billet 1, and at the same time the billet is moved to the first position.
As in the embodiment described above, the temperature is sent into the soaking heating coil _C2 by the operation of the cylinder 9c. As a result, the billet 1 is in the heating coil _C1 for temperature increase.
It is turned 180 degrees and inserted into the soaking heating coil _C2 .

In the above embodiment, the heating coil for temperature increase C ₁
The feeding direction of the billet is perpendicular to the longitudinal direction of the billet 1, and the heating coil for uniform heating is
Although the case has been described in which the feeding direction to C ₂ is the longitudinal direction of the billet 1, the present invention is different from the conventional device in which the feeding direction of the billet in the heating coil C ₁ is the longitudinal direction, as shown in FIG. It can also be used for Furthermore, as shown in FIG. 6, a rotating shaft 72 is provided vertically so as to be rotatable as shown by the arrow, and
Even if the clamper 10 is set to be rotatable through 180 degrees perpendicular to the support arm 73, the same effect as in the above embodiment can be obtained.

According to the present invention, when the billet is transferred from the heating coil for temperature raising to the heating coil for soaking, the billet is reversed, for example, by 180 degrees, so that the unavoidable temperature difference between the upper and lower sides of the billet in the heating coil for heating is evened out. It is possible to ensure uniform heating with no temperature gradient across the entire cross section with sufficient compensation within the heating coil C ₂ for heating, and also to compensate for the heating coil C ₁ for heating, which has a very large decrease in thermal efficiency with conventional equipment. This has great practical effects, such as eliminating the need for the upper skid rail 32 near the exit.

[Brief explanation of the drawing]

FIG. 1a is a partial cross-sectional front view showing an example of a conventional induction heating device in which a heating coil for temperature raising and a heating coil for soaking are arranged separately, and FIG.
A sectional view taken along the line A, Figure 2a is a diagram showing the temperature curve in the cross section of the billet due to the heating coil for heating in the conventional induction heating device illustrated in Figures 1a and b, and Figure 2b is also a diagram showing the temperature curve for the billet cross section of the conventional induction heating device illustrated in Figures 1a and b. A diagram showing a temperature curve in a cross section of a billet due to a heating coil, FIG. 3a is a partial sectional plan view showing an embodiment of the present invention,
Fig. 3b is an enlarged front view of the reverse transfer device in Fig. 3a, Fig. 3c is a sectional view taken along line B-B in Fig. 3a,
Fig. d is a diagram showing the temperature curve in the cross section of the billet obtained by the present invention, Fig. 4 is a front view showing another embodiment of the present invention, and Figs. FIG. 7 is a front view showing the third and fourth embodiments. C ₁ ... Heating coil for temperature increase, C ₂ ... Heating coil for soaking, 7 ... Inversion transfer device, 71 ... Rotation drive source, 72 ... Rotation shaft, 73 ... Support arm, 74 ...
Billet receiver, 75a, 75b, 75c... protrusion, 10... clamper, 101, 102... clamper finger.

Claims (1)

[Claims] 1. In an induction heating device in which a heating coil for temperature raising and a heating coil for soaking are provided separately, a billet discharged from the heating coil for heating is reversed and transferred to the heating coil for soaking. A reversal transfer type induction heating method characterized in that 2. In an induction heating device in which a heating coil for temperature raising and a heating coil for soaking are provided separately, an induction heating device is provided at a position approximately midway between the outlet side of the heating coil for heating and the inlet side of the heating coil for soaking. a billet receiver capable of accommodating a billet or a clamper capable of gripping a billet; and a support arm having one end pivotally connected to the rotating shaft and the other end fixed to the billet receiver or clamper. arm length,
The billet receiver or clamper is set so that it can be located near the exit of the heating coil for temperature raising and near the inlet of the heating coil for uniform heating, and the billet discharged from the heating coil for temperature raising is reversed and equalized. A reversal transfer type induction heating device that feeds heat to a heating coil. 3. The reversal transfer type induction heating device according to claim 2, wherein a protrusion parallel to the sliding direction of the billet is provided on the inner wall of the billet receiver. 4. The reversal transfer type induction heating device according to claim 2, wherein the fingers of the clamper can move in and out of the outlet side of the heating coil for heating.