JP4800391B2 - Induction heating device - Google Patents

Description

  The present invention relates to an induction heating apparatus that heats the left and right ends of a material to be heated conveyed in a hot rolling facility.

In general, in a hot rolling facility, a material to be heated is heated in advance to a predetermined temperature, and then continuously conveyed, passed through a plurality of rolling mills, and sequentially rolled to form a thin plate. The heated material has a problem that the both end portions thereof gradually dissipate heat during the conveyance process, and the temperature of this portion gradually falls compared to the central portion. If rolling is performed while the temperature at the end is lowered and the overall temperature is not uniform, the quality of the rolled steel sheet will not be constant, the hardness of the side end will increase, the material to be heated will crack, and the rollers of the rolling mill will wear out. Problems occur. For this reason, in general, an induction heating device is installed on the upstream side of the rolling mill of the hot rolling equipment, where both end portions of the material to be heated are locally heated with an inductor to bring the whole to a substantially constant temperature and then rolled. Has been.
For example, in the induction heating apparatus 100 shown in FIG. 8, the iron core 2R is formed in a C shape, and the upper core leg portion 4Ra and the lower iron core leg portion 4Rb that are vertically opposed to each other with the opening 3 of the C-shaped iron core 2R interposed therebetween, respectively. An inductor 6R in which a heating coil is wound to form an upper inductor portion 5Ra and a lower inductor portion 5Rb is provided. Furthermore, an inductor 6L having the same configuration as that of the inductor 6R is disposed to face the inductor 6R, and the inductor 6R and the inductor 6L are disposed between the front and rear transport rollers 9 and 9, as shown in FIG.

  When the induction heating apparatus 1 locally heats both end portions of the heated material 7, the end portions of the heated material 7 are passed through the openings 3 of the inductors 6 </ b> R and 6 </ b> L, and a high frequency is supplied from the power source to the heating coil. A current is passed through the upper inductor portions 5Ra and 5La and the lower inductor portions 5Rb and 5Lb to generate a magnetic flux in the vertical direction. An eddy current is induced in the heated material 7 by interlinking the magnetic flux perpendicularly to the heated material 7, and Joule heat is generated by the eddy current to locally heat both end portions of the heated material 7. Like to do.

  However, the material 7 to be heated is shifted left and right in the process of being conveyed by the conveying roller 9, and the dimension L at which the material to be heated 7 and the inductors 6R and 6L wrap may change as shown in FIG. .

  This lap dimension L is set according to the plate width and thickness of the material to be heated 7, and the heating temperature. However, when the lap dimension L between the material to be heated 7 and the inductors 6R and 6L being transferred changes, There was a problem that the material 7 to be heated could not be heated uniformly.

  Therefore, for example, in Patent Document 1 (Utility Model Registration No. 2588606), the inductor moves to keep the lap dimension L constant according to the left-right displacement of the material to be heated, so A control device for an induction heating edge heater capable of induction heating a heating material under optimum conditions has been proposed.

  The induction heating edge heater control device described in Utility Model Registration No. 2588606 can be used to induction heat the material to be heated under optimum conditions. The total weight of the induction heating edge heater is about 20 t, and induction heating is performed. In some cases, the moving device for moving the edge heater becomes large and the response speed is not sufficient.

  The present invention has been made in view of the above-mentioned problems, and is an induction with excellent responsiveness that can be induction-heated under optimum conditions in accordance with the left-right displacement of the material to be heated while being a compact facility. A heating device is provided.

FIG. 1 is a configuration diagram showing an embodiment of an induction heating apparatus according to the present invention. FIG. 2 is a configuration diagram of the induction heating apparatus according to the present embodiment in which two inductors are provided. FIG. 3 is a perspective view of the induction heating apparatus according to the present embodiment. FIG. 4 is an explanatory diagram illustrating induction heating of the induction heating apparatus according to the present embodiment. FIG. 5 is a diagram showing the relationship between the inductor gap value and the electric energy. FIG. 6 is a diagram illustrating a configuration of an induction heating apparatus that is a first modification. FIG. 7 is a diagram showing the relationship between the inductor position indicating the distance between the inductor and the material to be heated and the amount of electric power. FIG. 8 is a cross-sectional view showing a conventional induction heating apparatus. FIG. 9 is a plan view showing a conventional induction heating apparatus.

  Embodiments according to the present invention will be described below with reference to the drawings.

≪Configuration≫
FIG. 1 is a configuration diagram showing an embodiment of an induction heating apparatus according to the present invention.

  The induction heating apparatus 1 according to the present embodiment includes an inductor 6R that induction-heats the left and right ends of the heated material 7 so that the left and right ends of the heated material 7 are sandwiched from above and below, and a high-frequency power supply 10 that supplies power to the inductor 6R. A heating condition setting unit 11 that sets a target electric energy amount from the heating condition of the inductor 6R, an instrument current transformer 13R that detects a supply current to the inductor 6R, and an instrument that detects a supply voltage to the inductor 6 The transformer 14R, a power detector 15R that calculates the amount of power as a measured power amount from the detected current value and voltage value, and the power amount target value output by the heating condition setter 11 is converted into an optimum inductor gap value. In addition, an inductor gap value converter 16R that converts the measured power output by the power detector 15R into a measured inductor gap value, and an optimum inductor A gap deviation calculator 17R that calculates a deviation between the gap value and the measured inductor gap value as a gap deviation, a gap motor controller 18R that controls the gap motor 19R so as to eliminate the gap deviation, and an inductor 6R that is operated by the gap motor 19R The jack 20R is provided.

  In FIG. 1, one inductor 6 </ b> R is illustrated, but as shown in FIG. 2, the induction heating apparatus 1 according to the present embodiment has left and right in the short direction (width direction) of the material 7 to be heated. Another inductor 6L is arranged so as to sandwich the both end sides.

  That is, the inductor 6R has a C-shaped iron core 2R composed of an upper iron core portion 2Ra and a lower iron core portion 2Rb. The leg portion 4Rb is provided with an upper inductor portion 5Ra and a lower inductor portion 5Rb each wound with a heating coil. Further, an inductor 6L having the same configuration as that of the inductor 6R is disposed so as to be opposed to the opening 3 sandwiched between the upper iron core leg 4Ra and the lower iron core leg 4Rb as shown in FIG. The end side of the conveyed material 7 to be heated is passed.

  As a result, the inductor 6R causes a current to flow from the power source 10 to the upper inductor portion 5Ra and the lower inductor portion 5Rb to generate a magnetic flux Φ in the vertical direction, as shown in FIG. Then, the magnetic flux Φ is linked to the heated material 7 to induce eddy currents and generate Joule heat to heat the heated material 7.

  In addition, as shown in FIG. 2, the inductor 6R includes an upper inductor portion 5Ra and a lower inductor by rotating the upper core portion 2Ra about the hinge portion 2Rc with respect to the lower core portion 2Rb of the C-shaped iron core 2R. The inductor gap H, which is the distance from the part 5Rb, can be adjusted. The inductor 6L has a similar configuration.

  As a result, even when a left and right shift of the heated material 7 being conveyed occurs, the Joule heat generated in the heated material 7 is made uniform by adjusting the inductor gap H according to the generated shift. be able to.

≪Action≫
Next, the effect | action of the induction heating apparatus 1 which concerns on this embodiment is demonstrated with reference to FIG. Since inductor 6R and inductor 6L have the same configuration, only inductor 6R will be described below, and description of inductor 6L will be omitted.

  First, the heating condition setting unit 11 accepts a set value of electric energy that can be optimally heated from at least the material, plate width, and plate thickness of the material 7 to be heated by external input or the like, and sets the received electric energy set value as an electric energy target. As a value, it is output to the inductor gap value converter 16R.

  On the other hand, the heated material 7 conveyed by the conveying roller 9 travels between the upper inductor portion 5Ra and the lower inductor portion 5Rb of the induction heating device 1 at both ends, and is induction-heated by the magnetic flux generated therefrom. .

  The upper inductor portion 5Ra and the lower inductor portion 5Rb of the inductor 6R are energized with a high frequency current from the high frequency power supply 10 through the energization circuit 12R, and the supply current is detected by the current transformer 13R provided in the energization circuit 12R. The supply voltage is detected by the instrument transformer 14R.

  Then, the current value detected by the instrument current transformer 13R and the voltage value detected by the instrument transformer 14R are transmitted to the power detector 15R, and from the current value and voltage value received by the power detector 15R. The electric energy is calculated as the measured electric energy.

  The inductor gap value converter 16R converts the power amount target value set by the heating condition setter 11 into an optimum inductor gap value.

  Further, the inductor gap value converter 16R receives the measured power amount detected by the power detector 15R, and converts the received measured power amount into a measured inductor gap value.

  FIG. 5 is a diagram showing the relationship between the inductor gap value and the electric energy in the inductor 6R. Reference numeral 501 denotes the electric energy W with respect to the inductor gap value H.

  As shown in FIG. 5, the electric energy W indicates that the impedance of the inductor 6 </ b> R decreases as the inductor gap value H increases, and the electric energy W decreases.

  Therefore, the inductor gap value converter 16R calculates the optimum inductor gap value and the measured inductor gap value by converting the electric energy W into the inductor gap H using the relationship of FIG.

  Next, the gap deviation calculator 17R calculates a deviation between the optimum inductor gap value converted by the inductor gap value converter 16R and the measured inductor gap value as a gap deviation, and outputs the gap deviation to the gap motor controller 18R.

  Then, the gap motor controller 18R controls the gap motor 19R so as to eliminate the deviation between the optimum inductor gap value and the measured inductor gap value, that is, the gap deviation received from the gap deviation calculator 17R becomes zero. The amount is calculated, and the calculated control amount is transmitted to the gap motor 19R.

  The gap motor 19R operates based on the received control amount and operates the jack 20R.

  By the operation of the jack 20R, the upper iron core portion 2Ra of the inductor 6R rotates around the hinge portion 2Rc with respect to the lower iron core portion 2Rb.

  As a result, the inductor gap H, which is the distance between the upper inductor portion 5Ra and the lower inductor portion 5Rb, can be adjusted, and the responsiveness to the left and right displacement of the material 7 to be heated is improved while being a compact facility. Induction heating can be performed under optimum conditions.

<Modification 1>
The induction heating device 1 according to the present embodiment adjusts the inductor gap H, which is the distance between the upper inductor portion 5Ra and the lower inductor portion 5Rb, according to the amount of power of the inductor 6R.

  The induction heating apparatus 1a which is the modification 1 adjusts the inductor gap H according to the electric energy of the inductor 6R, and laterally moves the carriage to which the inductor 6R is fixed in the short direction of the material 7 to be heated. The distance between the material to be heated 7 and the inductor 6R is adjusted.

  In this way, the inductor 6R is moved to a position where the optimum condition is set, and the inductor gap H is adjusted at the same time, so that the heating temperature is finely adjusted with respect to the left and right shift of the material 7 to be heated. Induction heating can be performed.

≪Configuration≫
FIG. 6 is a diagram showing a configuration of an induction heating apparatus 1a that is the first modification.

  In addition to the configuration of the induction heating apparatus 1 according to the present embodiment, the induction heating apparatus 1a that is the modification 1 can further adjust the distance between the heated material 7 and the inductor 6R in the short direction of the heated material 7. Furthermore, an inductor motor 25R that moves the carriage 28R to which the inductor 6R is fixed, and an inductor position detector 26R that detects the position of the inductor 6R fixed to the carriage 28R moved by the inductor motor 25R as a measured inductor position detection value; The inductor position converter 22R that converts the target electric energy set by the heating condition setter 11 into the optimum inductor position set value, the optimum inductor position set value converted by the inductor position converter 22R, and the inductor position detector 26R. The deviation from the measured inductor position detection value detected by Comprising an inductor position deviation calculator 23R for calculating, an inductor motor controller 24R for controlling the inductor motor 25R on the basis of the inductor position deviation calculated by the inductor position deviation calculator 23R Te.

  In FIG. 6, one inductor 6 </ b> R is illustrated, but the induction heating device 1 a which is the first modification example is configured so as to sandwich both left and right ends in the short direction (width direction) of the heated material 7. Furthermore, another inductor 6L is arranged.

≪Action≫
Next, the effect | action of the induction heating apparatus 1a which is the modification 1 is demonstrated with reference to FIG.

  First, the heating condition setting unit 11 accepts a set value of power that can be optimally heated from at least the material, plate width, and plate thickness of the material 7 to be heated by an external input or the like, and sets the received power set value as a power amount target value. And output to the inductor position converter 22R.

  On the other hand, the heated material 7 conveyed by the conveying roller 9 travels between the upper inductor portion 5Ra and the lower inductor portion 5Rb of the induction heating device 1a at both ends, and is induction heated by the magnetic flux generated therefrom. .

  The inductor position detector 26R measures the position of the carriage 28R to which the inductor 6R is fixed, calculates position information of the inductor 6R from the measured position of the carriage 28R, and outputs it to the inductor position deviation calculator 23R as an inductor position detection signal. To do.

  The inductor position converter 22R converts the power target value output by the heating condition setting unit 11 into an optimum inductor position signal.

  FIG. 7 is a diagram showing the relationship between the inductor position indicating the distance between the inductor 6R and the material to be heated 7 and the amount of power. Reference numeral 701 denotes the electric energy W with respect to the inductor position M.

  As shown in FIG. 7, the amount of electric power W is such that the impedance of the inductor 6R decreases as the inductor position M increases, that is, the distance between the inductor 6R and the heated material 7 in the short direction of the heated material 7 increases. This shows that the amount of electric power W decreases.

  The inductor position converter 22R calculates the optimum inductor position by converting the electric energy W into the inductor position M according to the relationship of FIG. 7, and outputs the optimum inductor position signal to the inductor position deviation calculator 23R.

  Next, the inductor position deviation calculator 23R receives the inductor position detection signal detected by the inductor position detector 26R. Then, from the received inductor position detection signal and the optimum inductor position signal received by the inductor position converter 22R, the deviation between the measured inductor position and the optimum inductor position is calculated as the inductor position deviation, and the calculated inductor position deviation is calculated as the inductor position deviation. The deviation signal is transmitted to the inductor motor controller 24R.

  Next, the inductor motor controller 24R controls the inductor motor 25R so as to eliminate the deviation between the optimum inductor position and the measured inductor position, that is, so that the inductor position deviation received from the inductor position deviation calculator 23R becomes zero. The control amount is calculated, and the calculated control amount is transmitted to the inductor motor 25R.

  The inductor motor 25R operates based on the received control amount, and causes the wheel 29R attached to the bottom of the carriage 28R to which the inductor 6R is fixed to move laterally in the short direction of the material 7 to be heated.

  Thus, the inductor 6R fixed to the carriage 28R can be moved so that the inductor position M measured by the inductor position detector 26R becomes the set optimum position. Further, by adjusting the inductor gap H, it is possible to perform induction heating while finely adjusting the heating temperature with respect to the left and right shift of the heated material 7 being conveyed.

Claims (2)

A lower iron core portion around which a heating coil is wound, an upper iron core portion arranged opposite to the lower iron core portion with an inductor gap at a predetermined interval and having a heating coil wound around the end portion; and An inductor that heats the material to be heated that is formed in a C shape and includes a hinge portion that pivotally supports the upper iron core portion with respect to the lower iron core portion;
An electric energy detecting means provided in an energization circuit of the heating coil for detecting the electric energy supplied to the heating coil;
Heating condition setting that sets the optimum heating condition of the heating coil from at least the material, plate width, and plate thickness of the material to be heated heated by the inductor, and sets the target amount of electric power according to the set optimum heating condition Means,
An inductor gap value conversion means for converting the set power amount target value into an optimum inductor gap value and converting the power amount detected by the power amount detection means into a measured inductor gap value;
A gap deviation calculating means for calculating a deviation between the converted optimum inductor gap value and the measured inductor gap value as a gap deviation;
An induction heating apparatus comprising: gap motor control means for controlling a motor that rotates the upper iron core so as to eliminate the calculated gap deviation. An inductor motor that moves the inductor so that the distance between the heated material and the inductor in the short direction of the heated material can be adjusted;
Inductor position detection means for detecting the position of the inductor moved by the inductor motor as a measured inductor position detection value;
Inductor position conversion means for converting the electric energy target value set by the heating condition setting means into an optimum inductor position setting value;
Inductor position deviation calculating means for calculating a deviation between the optimum inductor position setting value converted by the inductor position converting means and the measured inductor position detected value detected by the inductor position detecting means as an inductor position deviation;
The induction heating apparatus according to claim 1, further comprising: an inductor motor control unit that controls the inductor motor so as to eliminate the inductor position deviation calculated by the inductor position deviation calculation unit.

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