JPS625026Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an induction heating device installed in a hot rolling line.

[Technical background of the invention and its problems]

As shown in Figure 1, induction heating equipment is generally installed before the finishing mill of a hot rolling line, and
The area where the temperature has decreased near the edges in the width direction is heated to about the same temperature as the center area, thereby improving the material quality and rolling characteristics.

The transverse flux method is used for the inductor 3 in the heating section, which enables efficient heating of even thin plates.As shown in Fig. 2, the material 1 is passed between the upper and lower inductors 3a and 3b, so high efficiency is achieved. In order to obtain this, the gap G between the upper and lower inductors needs to be kept as narrow and constant as possible while maintaining the minimum necessary distance a between the material 1 and the inductor 3. Conventionally, as a method for keeping the gap G constant, a guide roller method or the like has been used.

However, as shown in Fig. 1, the material usually has a warp at the leading end 1a and the trailing end 1b, and to avoid this, conventionally, the leading end and trailing end of the material are not heated, and the inductor 3 is evacuated using an air cylinder or the like. let me,
Collision between the material 1 and the guide roller or inductor 3 was prevented. For this reason, it was not possible to heat the entire length of the material, resulting in a decrease in yield and premature damage to the rolling mill.

[Purpose of invention]

An object of the present invention is to provide an induction heating device that can heat a material over its entire length from the leading end to the trailing end.

[Summary of the idea]

In particular, the device according to the present invention includes a warpage detection device, a gap control circuit, an inductor lifting device, and a heating power control circuit. An induction heating device that sets the inductor gap wider than normal to allow the material to pass through safely, and at this time, corrects the heating power according to the set gap so that the required heat input can be given to the entire length of the material. It is.

That is, the present invention is an induction heating device consisting of inductors installed facing each other with a gap and a heating power supply device that supplies alternating current power for induction heating to the inductors. A lifting device that adjusts the dimensions of the material, a warpage detection device that measures the amount of warpage of the material sent to the gap, and a gap adjustment device that outputs a drive signal to the lifting device based on the signal from the warpage detection device. This is an induction heating device that is equipped with a heating power supply whose output can be adjusted and one or more sets of two intactors facing each other with a predetermined gap above and below the intactor in order to heat the moving material. , an inductor lifting device that makes it possible to adjust the gap, a means for detecting the leading and trailing edges of the material, a material warpage detection device installed upstream of the inductor in the line, and a gap adjustment circuit that widens the gap between the inductors according to the warpage. and an induction heating device characterized by comprising a power correction circuit that corrects heating power by setting a gap, and an induction heating device characterized by having a power correction circuit that corrects heating power by setting the gap between the inductor and the tip and rear end of the material. The induction heating device is characterized in that it is set to be wider (G ₀ + S) than the gap setting G ₀ in the normal part by the amount of warpage S, and the heating power correction is approximately linearly proportional to the gap setting G (α, G +
β) (αβ is an appropriate constant).

[Example of idea]

Next, embodiments of the present invention will be described. FIG. 3 shows an induction heating device consisting of inductors 3a and 3b that have a gap G and are installed facing each other, and a heating power source 5 that supplies AC power for induction heating to the inductors 3a and 3b. Inductor 3a, 3b
a lifting device 4 that adjusts the dimensions of the gap G by raising and lowering the gap G; a warp detecting device 6 that measures the amount of warpage S of the material 1 sent to the gap G; This figure shows an induction heating device including a control device 7 that outputs a drive signal.

The material 1 flows over the table roller 2 in the direction of the arrow, but there is a required gap G above and below the material 1.
Inductors 3a and 3b are arranged so as to maintain the same, and these inductors 3a and 3b can be moved up and down by a lifting device 4, so that the gap G can be adjusted. The inductors 3a, 3b are connected to a heating power source 5 whose output can be adjusted.

A warpage detection device 6 is installed upstream of the line from where the inductors 3a and 3b are installed. This warpage detection device 6 includes a front end 1a and a rear end 1b of the material.
This method detects the amount of upward or downward curvature S (Fig. 2) of the material, and there are methods such as a method in which a plurality of transmission type photoelectric switches are arranged in the vertical direction, or a method in which the material position is detected by an image sensor.

The lifting device 4, the heating power source 5, and the warpage detection device 6 are connected to a control device 7. The configuration of the control device 7 will be explained using FIG. 4. The leading and trailing edge detection circuit 8 inputs the signal of the material detection sensor 11 and the signal of the movement amount detector 12 that detects the amount of movement of the material, and determines when the leading edge or the trailing edge of the material is in the area of the inductors 3a and 3b. Then, a signal is output to the gap selection circuit 10. The gap selection circuit 10 inputs the signal of the amount of warp S from the warp detection device 6, and calculates the gap setting _G1 when the leading or trailing end passes (G=S+t+2a) (t: material 1). thickness) and the predetermined steady gap G ₀ (=t
+2a) and outputs the gap setting value G to the lifting device 4.

The gap setting value G is also output to the heating power correction circuit 11, and the reference heating power _P0 is calculated Pw= _P0・f
(G) (f is a function) and outputs the heating power Pw to the heating power source 5.

Now, when the material 1 enters, the material detection sensor 11 first detects the leading edge of the material, and the trailing edge detection circuit 8 integrates the amount of movement of the material based on the signal from the movement amount detector 12, and then Alternatively, it is determined when the rear end is located at the inductor 3a, 3b portion, and an output is output.

Also, based on the signal of the amount of warpage S of the leading end or trailing end detected by the warping detection device 6, the gap calculation circuit 9 sets the gap when the leading end or trailing end passes.
G ₁ is calculated by calculating G ₁ = S + t + 2a, the gap selection circuit 10 selects the gap G ₁ while passing the leading or trailing edge of the material 1, and the inductor lifting device 4 selects a gap that is wider by the amount of warp S than usual. G ₁ is set.

On the other hand, when the material passes through the middle part, there is a steady gap G ₀
(=t+2a) is selected, and the gap is narrowed from when the tip passes.

Similarly, when the rear end 1b of the material 1 passes through the inductors 3a, 3b, the inductors _3a , 3
b is set.

Note that if there is downward warpage, the inductor 3b is set wide downward.

If the inductor gap setting is widened when the material passes through the leading and trailing ends, the heating efficiency will decrease, so the standard heating power P ₀ is corrected using the gap G set in the power correction circuit 12 by calculating Pw = P ₀ · f (G). The material 1 is controlled so that the required amount of heat is input to the material 1. A linear function of G is generally sufficient for f.

With the above configuration, the tip 1a of the material
When the rear end 1b passes through, the gap G of the inductor 3
is set wider by the amount of material warp S than normal.
G ₁ , as shown in Figure 2, allowing safe operation without evacuating the inductor, and the gap G
Since the heating power Pw is corrected according to the required heat input, the entire length of the material can be heated.

The above embodiment includes the power supply device 5 and the lifting device 4.
Although the configuration has been described in which one set of units is provided, the configuration can be similarly applied even when the number of units is increased as necessary.

Furthermore, the detection of the leading and trailing ends is not limited to the method using the material detecting sensor 11 and the movement amount detecting device 12 of the embodiment.

The warpage detection device 6 may be one that detects not only the amount of warpage S of the material 1 but also the height (S+t) of the warped portion of the material from the pass line. In this case, for example, the upper inductor is set at a height of S+t+a from the pass line when the tip passes.

In addition, inductor 3 when passing the tip or rear end
The gap _G1 setting does not necessarily have to be widened by the amount of warpage S, but if the distance a between the inductor 3 and the material 1 is a certain distance or more, the amount by which the gap is widened can be made smaller than the amount of warpage S. It is. In this case, this is possible by continuously measuring the amount of warpage of the material 1 using the warp detection device 6 and detecting the shape of the warp.

[Effect of idea]

As explained above, by implementing the present invention, it is possible to perform the necessary heat treatment on the leading and trailing ends even if the material is warped at the leading and trailing ends, thereby improving the yield of the material. Damage to the rolling mill can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional induction heating device, Fig. 2 is a longitudinal sectional view of the inductor section of Fig. 1, Fig. 3 is a block diagram of an induction heating device showing an embodiment of the present invention, and Fig. 4 1 is a block diagram of a gap control device according to the present invention. DESCRIPTION OF SYMBOLS 1... Material, 3... Inductor, 4... Lifting device, 5... Heating power source, 6... Warpage detection device, 7...
...Control device, 8...Top/rear end detection circuit, 9...
Gap calculation circuit, 10... Gap selection circuit,
11... Heating power correction circuit.

Claims (1)

[Scope of utility model registration request] In an induction heating device consisting of inductors that are installed facing each other with a gap, and a heating power supply device that supplies AC power for induction heating to the inductors, the size of the gap is determined by raising and lowering the inductors. a warpage detection device that measures the amount of warpage of the material sent to the gap, and a gap adjustment device that outputs a drive signal to the lifting device based on a signal from the warpage detection device. Induction heating device.