JPH0637675B2 - Continuous soaking method for thin metal plates - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a continuous soaking method for uniform heating in the width direction of a thin metal plate by using a transverse magnetic flux type induction heating method for heating a continuously running metal plate. According to the method, the conductor coil can be moved in the width direction of the metal plate, and the conductor coil is continuously reciprocated with a required amplitude, or the center of the conductor coil is moved to follow the center line of the metal plate to reciprocate horizontally, thereby continuously traveling. The present invention relates to a continuous soaking method for a thin metal plate that prevents uneven heating caused by the position of the metal plate changing in the width direction.

BACKGROUND ART In general, an induction heating method for a thin metal plate is classified into a longitudinal magnetic flux method and a transverse magnetic flux method depending on the manner of intersection with the magnetic flux of the thin metal plate of the material to be heated.

The thin metal plate by the longitudinal magnetic flux method is limited to magnetic material, and if the plate thickness becomes thin, a frequency of several hundred kHz to several kHz is required, which makes it difficult to cope with it and lowers heating efficiency. To do.

Therefore, regardless of whether the material is magnetic or non-magnetic,
A transverse magnetic flux type induction heating method capable of heating at a frequency of 3 kHz or less is preferable.

However, the transverse magnetic flux induction heating method has not been put to practical use in industrial mass production operations because the temperature distribution in the width direction of the thin metal plate is poor and it is difficult to obtain uniform heating.

That is, the widthwise position (passing position) of the conductor coil and the thin metal plate is constantly changed by the bending (camber) in the longitudinal direction of the thin metal plate due to the rewinding of the coil, and the conductor coil and the thin metal plate are constantly changed. The optimum heating position changes, for example,
Since the centers of the metal plate and the coil are displaced by only about 1% of the width of the metal plate, a temperature difference of several tens to one hundred and several tens of degrees is generated on both sides of the metal plate, which causes a serious problem in heat uniformity in the plate width direction. there were.

On the other hand, as a modification of the transverse magnetic flux method, a method has been proposed in which an auxiliary inductor is attached to a conductor coil to measure the soaking of a thin metal plate.

However, in the transverse magnetic flux method using the auxiliary inductor, the material of the thin metal plate of the material to be heated, width, it is necessary to adjust the position of the auxiliary inductor based on the thickness dimension, It is convenient for heating thin metal plates of the same material and size, but there are many problems in general-purpose heating of thin metal plates of different materials and sizes.

An object of the present invention is to prevent uneven heating due to positional variation in the width direction of a continuously running thin metal plate when heating a metal plate using an induction heating method of a transverse magnetic flux method, and the material and width of the thin metal plate. An object of the present invention is to provide a continuous soaking method capable of realizing continuous heating with an excellent soaking degree regardless of the plate thickness dimension.

SUMMARY OF THE INVENTION The present invention has variously studied for the purpose of a continuous soaking method capable of obtaining a soaking property in the width direction of a thin metal plate, the conductor coil facing the metal plate is movable in the metal plate width direction, It is possible to prevent temperature gradient in the width direction of the metal plate by always reciprocating horizontally with the required amplitude, or by moving the center of the conductor coil to follow the center line of the metal plate and reciprocating horizontally to continuously move metal. The present inventors have completed the present invention by finding that heating unevenness that occurs due to a positional change in the width direction of a plate can be prevented and excellent heat uniformity in the plate width direction can be obtained.

According to the present invention, a conductor coil is arranged on each of the upper and lower surfaces of a traveling thin metal plate so as to face each other, and in a continuous soaking method for a thin metal plate in which transverse magnetic flux is applied to perform induction heating, it is possible to move in the width direction of the metal plate. A method for continuously soaking a thin metal plate, characterized in that the conductor coil is horizontally reciprocated with a required amplitude with respect to the metal plate to perform induction heating.

Structure of the Invention The present invention is characterized in that the conductor coil facing the metal plate is movable in the width direction of the metal plate, and the conductor coil is horizontally reciprocated with respect to the surface of the metal plate at a required cycle and amplitude. However, it is necessary to appropriately select the reciprocating range and the reciprocating speed according to the width of the metal plate.

Further, according to the present invention, in addition to the horizontal reciprocating movement of the conductor coil in the width direction of the metal plate, the conductor coil is moved to follow the center line of the metal plate whose position changes in the width direction during continuous running, so that the position change in the thickness direction can be prevented. It is possible to prevent the uneven heating caused by the heating. In controlling the position of the conductor coil, the position reference to be controlled is, for example, the center line of the traveling line of the metal plate, the displacement of the traveling metal plate with respect to this is detected, and the conductor coil is centered at the center of the metal plate. Detecting the position of one end of a metal plate passing through the required width of the travel line, calculating the plate center according to the set metal plate width, and centering the conductor coil with respect to the center line As long as the conductor coil can always move following the center line of the metal plate by detecting the width end positions of the metal plate with a pair of detectors arranged at intervals, the control standard, means Even available.

Further, in the present invention, the centering accuracy can be improved by interlocking with the position adjusting device for the metal plate on the traveling line when the metal plate coil is unwound.

The method of the present invention can be applied to the case where the thin metal plate which is the material to be heated is a single plate or a plurality of plates made of different materials having similar electric resistances.

The mechanism that supports the conductor coils placed on the upper and lower surfaces of the metal plate so as to be movable in the plate thickness direction has a pair of conductor coils cantilevered and slidably moves in the vertical axis direction so that it can move closer to and away from the metal plate. The coil support made possible, further in the metal plate width direction,
That is, in addition to a biaxial sliding mechanism capable of sliding in the horizontal axis direction, known moving means can be adopted, and the drive source is a hydraulic device such as a hydraulic cylinder, a step motor, a servo motor, or an electric motor. It can be appropriately used according to the moving means.

Further, as a mechanism for supporting the conductor coil and capable of moving in the plate thickness direction and reciprocating, a horizontal sliding mechanism composed of a slider and a rail is stacked in two stages as shown in the embodiment, and centering with respect to the center line of the metal plate. And the drive source for reciprocating motion can be independent.

For the position detector that detects the position of the running metal plate in the plate thickness direction, if the position deviation from the preset reference position can be detected, a sensor of any configuration such as a follower roller that combines a differential transformer and a copying roller can be used. Although it can be used, a non-contact type optical linear sensor or the like is preferable because a metal plate runs.

The conductor coil position detector may have any configuration such as a potentiometer or a pulse position oscillator as long as it can detect a position deviation from a preset reference position. Various means such as movement of the coil itself, movement of the coil support, its mounting table, and the like, and measurement and detection of the amount of rotation and amount of movement of the actuator of the moving mechanism can be employed.

The comparison calculator calculates the widthwise position deviation amount of the metal plate from a position arbitrarily set in advance by the signal from the metal plate position detector, and determines the widthwise following amount of the conductor coil with respect to the metal plate. When the position deviation can be calculated by the detector or another arithmetic unit, it is only necessary to determine the follow-up amount, and it is also possible to configure the controller of the moving drive source of the conductor coil which will be described later. .

As the controller, a drive controller for hydraulic, electric, or electromagnetic actuators can be appropriately selected according to the moving mechanism of the conductor coil or its support and the drive source thereof.

The metal plate traveling speed meter can use the signal from the rewinding machine of the metal plate coil in addition to the measurement in the vicinity of the conductor coil. Furthermore, the signal of the rewinding position of the metal plate coil can be input to the comparison computer. Then, the position deviation signal of the metal plate may be corrected, or the position deviation measurement accuracy may be improved.

The moving speed meter of the conductor coil directly measures the moving speed of the conductive coil itself, or measures the moving speed of the coil support, the mounting table, or the like, or a driving actuator,
Means such as detection or calculation based on rotation amount and movement amount signals from a position detector or the like can be appropriately adopted.

The width of the conductor coil in this invention (1) and the width of the material to be heated (L)
Although the above relationship depends on the material to be heated, plate thickness, width, etc., 1 / L is generally preferably 0.9: 1.1.

In the present invention, the range of horizontal reciprocation (amplitude) of the conductor coil in the width direction of the metal plate is preferably 0.05 W to 0.20 W when the plate width of the metal plate is 2 W.

Disclosure of the Invention Based on the Drawings FIG. 1 is a perspective explanatory view of an induction heating apparatus for carrying out the continuous soaking method according to the present invention.

FIG. 2 is a block diagram showing a control system of the induction heating device shown in FIG.

The conductor coil (2) arranged near the upper and lower surfaces of the metal plate (1) of the material to be heated is a copper pipe through which cooling water can pass, which is spirally arranged.

A pair of upper and lower conductor coils (2) and (2) have a slider (4) provided at one end thereof and hold a vertical rail (5) provided on the side surface of a coil support (3) made of a box body (not shown). The position can be adjusted vertically by the lock mechanism.

The coil support (3) is placed on the slide base (6) via the reciprocating base (20), and the slider (7) on the bottom of the slide base (6) is laid on the base (8). The metal plate (1) is configured to be slidable by gripping the horizontal rail (9) in the plate width direction.

Furthermore, the reciprocating table (20) on which the coil support (3) is placed is
A slider (21) on the bottom surface is configured to be slidable by holding a horizontal rail (22) in the plate width direction of the metal plate (1) laid on the slide base (6).

The sliding base (6) is a hydraulic cylinder (1) mounted on a base (8).
0) slides horizontally, that is, the hydraulic cylinder
The conductor coil (2) moves in the width direction of the metal plate (1) by the operation control of (10).

Also, with a position detector (11) using a position sensor such as a potentiometer placed on the base (8) and connected to the sliding base (6),
The current position of the conductor coil (2) (2) is detected.

To drive the reciprocating table (20), a rotational force is converted into a linear reciprocating motion, for example, a converter (23) such as a crank mechanism and a servo motor (24) as a drive source are provided on a sliding table (6). It is configured to be placed and reciprocally moved in the width direction of the metal plate (1) with a predetermined amplitude.

The servomotor (24) is provided with, for example, a conductor coil reciprocating amount detector (25) such as an optical pulse counter and a reciprocating velocity detector (26).
(2) It is configured to detect the position and speed of (2).

Here, the reciprocating motion detector attached to the servo motor (24)
The position signal of the conductor coil (2) and (2) is obtained at (25) and the speed detector
Although the speed is detected by (26), the position and speed of the conductor coils (2) and (2) can be detected by one detector.

Further, an optical position detector (12) for detecting the width direction position of the metal plate (1) is arranged at a position opposite to both ends of the metal plate (1) on the upstream side of the conductor coils (2) (2). It is installed and fixed to the slide base (6) via the stand (13).

Further, a traveling speed meter (14) for measuring the traveling speed of the metal plate (1) is arranged near the metal plate (1) on the downstream side of the conductor coils (2) (2).

An example of carrying out the continuous soaking method of the present invention using the induction heating device having the above-mentioned configuration will be described.

Below is always a conductor coil with respect to the center line of the metal plate (1).
(2) While matching the electrical centers of (2), the conductor coil (2)
An example of horizontally reciprocating (2) with a predetermined amplitude will be described.

Before heating, it is rewound in advance, and the center line of the thin metal plate (1) threaded in the required line to be wound and the transverse magnetic flux conductor coil (proximally arranged on the upper and lower surfaces of the metal plate (1) ( 2) Arbitrarily set the position of the electrical center line in (2).

After the above setting, the conductor coils (2) and (2) are energized and the metal plate (1) is run to perform induction heating.

Next, the metal plate position detector (12) disposed in the width direction facing portion of the running metal plate (1), the width direction position detection signal of the metal plate (1) is a position deviation calculator ( It is output to A).

The deviation signal output from the position deviation calculator (A) and the metal coil position setter attached to the rewinding device for the metal plate coil
The comparison signal with the position signal from (F) is compared with the arbitrarily set center position in the comparison calculator (B), and the conductor coil (2)
The moving direction and the amount of (2) with respect to the metal plate (1) are determined.

The signals of the determined moving direction of the conductor coils (2) and (2) and the following amount thereof are input to the servo amplifier (C) which is a drive controller.

On the other hand, the position signal from the conductor coil position detector (11) is converted into a deviation signal by the position deviation calculator (D) and input to the servo amplifier (C).

In the servo amplifier (C), the tracking amount signal and the conductor coil (2)
While comparing with the position deviation signal, the servo valve (E) that controls the hydraulic cylinder (10) is drive-controlled to
By moving the slide table (6) in the required direction and by the required amount with the operation of (0), the conductor coils (2) and (2) are moved through the coil support (3) to the width of the metal plate (1). Moves continuously following the direction.

By the control, the longitudinal center line of the metal plate (1) and the electrical center line of the conductor coil (2) (2) match the preset positional relationship, that is, the conductor coil (2) (2) The coil support (3) can be centered so that the coil always coincides with the center line of the metal plate (1).

During the control, the horizontal reciprocating motion of the conductor coils (2) (2) is controlled separately from the above. That is, the required amount of reciprocating motion is set in advance in the reciprocating motion calculator (G) from the reciprocating motion setter (H), and the servo motor (I) and the servo driver (J) are used in accordance with the set value. Control the rotation of 24).

At this time, the reciprocating amount calculator (G) receives the position signals of the conductor coils (2) and (2) from the reciprocating amount detector (25) attached to the servo motor (24) and corrects the reciprocating amount. To do.

Furthermore, in the comparison calculator (K), the speed signal of the metal plate (1) from the traveling speedometer (14) and the conductor coil (2) from the reciprocating speed detector (26) attached to the servomotor (24) are used. ) (2) is compared with the speed signal, and a correction value is output to the servo amplifier (I) so as to have a preset relationship to correct the reciprocating amount.

By such control, the conductor coils (2) and (2) are controlled by the metal plate (1) at a predetermined amplitude amount and speed according to the traveling speed of the metal plate (1).
Reciprocates in the plate width direction relative to the surface, and further
(2) The center of reciprocation of (2) always coincides with the center line of the metal plate (1), and the transverse magnetic flux of the conductor coils (2) and (2) acts uniformly in the width direction of the metal plate (1). However, the induction heating becomes uniform and the temperature gradient in the plate width direction unlike the conventional method does not occur.

Here, the example in which the servo amplifier (I) is controlled by the signals from the reciprocating motion amount computing unit (G) and the comparison computing unit (K) is shown. 2) The position signal of (2) and the speed signal of the metal plate (1) may be input, a required comparison operation may be performed, and a control signal to the servo amplifier (I) may be output.

Example For the metal plate of the material to be heated, use a coil of material 18-8 series stainless steel dimensions width 300 mm × thickness 2.5 mm, 0.1 m / sec
Sent out at the speed of.

A spiral coil made of a copper tube was used as the conductor coil.

Each detector has a metal plate position detector: optical linear sensor Coil position detector: potentiometer type metal plate traveling speed detector: optical pulse counter reciprocating motion detector: optical pulse counter reciprocating speed detector: optical A pulse counter was used.

Under the above-mentioned running condition and induction heating condition of the metal plate, the continuous soaking method according to the present invention, that is, the case where the conductor coil is reciprocated in the plate width direction (Invention 1), reciprocates while following the center of the metal plate. In the case of the induction heating method of moving (invention 2) and the case of the conventional induction heating method,
Table 1 shows the temperature difference in the width direction and the longitudinal direction (conductor coil length) of the material to be heated and the heating efficiency when induction heating is performed by the continuous soaking method according to the present invention and the conventional method. The temperature distribution situation (longitudinal direction in the figure) in the width direction of the metal plate after induction heating by the method (Fig. A) and the present invention 2 (b) is shown.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view of an induction heating apparatus for carrying out the continuous soaking method according to the present invention. FIG. 2 is a block diagram showing a control system of the induction heating device shown in FIG. FIGS. 3a and 3b are graphs showing the temperature gradient in the width direction of the metal plate after induction heating by the conventional method and the method of the present invention. 1 …… Metal plate, 2 …… Conductor coil, 3 …… Coil support, 4,7,21 …… Slider 5 …… Vertical rail, 6 …… Slide base 8 …… Base, 9 …… Horizontal rail , 10 …… hydraulic cylinder, 11 …… conductor coil position detector, 12 …… metal plate position detector, 13 …… stand, 14 …… speedometer, 20 …… reciprocating table, 23 …… converter, 24 …… Servo motor, 25 …… Reciprocating motion detector, 26 …… Reciprocating speed detector, A, D …… Position deviation calculator, B …… Comparison calculator, C …… Servo amplifier, E …… Servo Valve, F ... Position setter, G ... Reciprocation amount calculator, H ... Reciprocation amount setter, I ... Servo amplifier, J ... Servo driver, K ... Comparison calculator.

Claims (1)

[Claims] 1. In a continuous soaking method for a thin metal plate, in which conductor coils are arranged on the upper and lower surfaces of a traveling thin metal plate so as to face each other and a transverse magnetic flux is applied to the thin metal plate for induction heating, the metal plate can be moved in the width direction of the metal plate. A method for continuously soaking a thin metal plate, wherein the conductor coil is horizontally reciprocated with a required amplitude with respect to the metal plate for induction heating.