JP4566831B2 - Steel plate heat treatment equipment - Google Patents

Description

  The present invention is directed to induction heating and subsequent quenching of a steel sheet while moving the steel sheet in the longitudinal direction for grain refinement treatment that is performed by repeatedly applying a heat treatment that applies rapid heating and subsequent quenching to the steel sheet. The present invention relates to a steel plate heat treatment apparatus that sequentially applies.

It is known that ultra-fine-grained steel materials can be obtained by repeatedly applying a heat treatment that rapidly heats immediately above Ac3 and then rapidly cools, as well as increases the strength and toughness if crystal grains are refined. (For example, see Non-Patent Document 1), which is applied to a mold or a hot-rolled steel strip (for example, see Patent Documents 1 to 3).
In the case of a steel mold (see, for example, Patent Document 1), a fine fine particle layer is formed by repeating rapid heating and rapid cooling for reciprocating the austenitizing temperature range and martensitic transformation temperature range multiple times on the surface of the mold. By forming, the hardness and toughness are made compatible, and in particular regarding toughness, not only the Charpy impact value for a relatively dull notch is improved, but also the fracture toughness for a sharp notch is improved. The rapid heating is embodied by high frequency induction heating, and the rapid cooling is realized by water cooling.

  In the case of a hot-rolled steel strip (see, for example, Patent Documents 2 and 3), crystal grains are refined by repeating rapid heating and rapid cooling while moving the steel strip in the longitudinal direction. At that time, rapid heating is performed by high-frequency induction heating with the aim of austenite conversion, and rapid cooling is performed by water cooling with the aim of martensitic transformation. In addition, there are reciprocating movements of steel strips (for example, Patent Document 2) and unidirectional movements (for example, Patent Documents 3 and 3), both (Patent Documents 2 and 3), In addition to heat treatment, rolling and winding are also performed.

Revised 5th edition, page 80, “Strengthening by 2,5,8 ultra-fine processing”, published by Maruzen Co., Ltd., Japan Iron and Steel Institute (October 1, 1944) Japanese Patent Laid-Open No. 6-315752 (pages 1 and 2, FIG. 6) Japanese Patent Laid-Open No. 2002-066665 (first page, FIG. 1) JP 2004-099984 A (first page, FIG. 2)

  By the way, there is a request to increase fracture toughness while maintaining high hardness by grain refinement processing for a finite length steel plate, but when heat treating almost the entire steel plate, if the steel plate is long, Heat treatment of the entire area at a stretch entails an increase in the size of the inductor and the high-frequency power supply, which increases the cost, and it is conceivable to adopt a hot-rolled steel strip method in which the heat treatment is repeated while moving the steel sheet in the longitudinal direction. However, in many cases, a finite-length steel sheet cannot be wound up because it is not thin and long enough to be applied to a coiler.

In addition, winding is the same as rolling, but the force of the steel strip is forced by applying a strong external force, so the relative position between the steel strip and the inductor during heat treatment does not change much, so the heat treatment equipment is standard. While there is an advantage in that it is sufficient, there is a tendency to leave internal stress.
For this reason, it is required not to adopt the conventional method as it is, but to keep the steel plate as free as possible when moving the steel plate in the longitudinal direction for heat treatment. And as such a holding means, it is possible to support a steel plate at both ends.

However, when the steel plate is held from both ends in the longitudinal direction in an allowable state, if a long steel plate is lying, a large bending stress is generated in the central portion due to its own weight.
In addition, since bending deformation such as warping and twisting is allowed in the free state, the distance between the steel plate and the inductor may fluctuate greatly depending on how it is bent.
In addition, since such undesired deformation occurs every time the heat treatment is performed, the steel plates do not have a flat plate shape suitable for use in the subsequent heat treatment or material.

Therefore, when repeating rapid heating and rapid cooling while moving the steel sheet in the longitudinal direction for grain refinement treatment, bending deformation due to its own weight is unlikely to occur even if the finite length steel sheet is held in an allowable state from both ends. Further, it is a technical problem to realize a steel plate heat treatment apparatus that can continue the heat treatment even if it is bent by the heat treatment.
Further, it is a further technical problem to realize a steel plate heat treatment apparatus that does not accumulate bending deformation even when heat treatment is repeated.

  The steel plate heat treatment apparatus of the present invention (Claim 1) was devised in order to solve such a problem, and is a crystal grain that is repeatedly subjected to heat treatment that applies rapid heating and subsequent rapid cooling to the steel plate. In a steel plate heat treatment apparatus that sequentially applies induction heating and subsequent quenching to the steel plate while moving the steel plate in the longitudinal direction for the refinement treatment, the steel plate is engaged with both ends of the steel plate in the longitudinal direction. A supporting member for holding the steel sheet in a longitudinally-oriented state and in a bending-permitted state, a lifting mechanism for moving the steel sheet in the longitudinal direction via the support member, and the steel sheet for induction heating of the steel sheet. Inductors arranged so as to face the entire section in the longitudinal direction in the width direction, and facing the partial sections in the longitudinal direction across the entire area in the width direction of the steel plate below the inductors. Said steel plate arranged to A thermal processing unit and the water discharge portion becomes set to perform rapid cooling, characterized in that it comprises a horizontal plane adjusting mechanism for adjusting the position and the in-plane orientation of the thermal processing unit is moved in a horizontal plane.

  The steel plate heat treatment apparatus according to the present invention (Claim 2) is the steel plate heat treatment apparatus according to Claim 1, and a distance sensor for measuring a confronting distance between the inductor and the steel plate is provided in the inductor. It is installed at a plurality of locations in the width direction of the steel plate in a fixed state, and follow-up control is performed to keep the facing distance constant by operating the horizontal plane adjustment mechanism based on the data. To do.

  Furthermore, the steel plate heat treatment apparatus according to the present invention (Claim 3) is the steel plate heat treatment apparatus according to Claim 2, wherein the water discharge part is further divided in the longitudinal direction, and some of the divided bodies are The water discharge amount can be adjusted, a deformation detecting means for detecting the deformation state of the steel sheet is provided, and the water discharge amount of the water discharge portion is adjusted so as to correct the deformation.

  Moreover, the steel plate heat treatment apparatus according to the present invention (Claim 4) is the steel plate heat treatment apparatus according to Claim 3, and further, as the deformation detection means, the steel plate based on an adjustment amount in the horizontal plane adjustment mechanism. And a means for detecting the deformation state of the steel sheet based on a displacement amount of the end portion of the steel sheet that is detected by a distance sensor that is provided in the vicinity of the support member and moves together therewith. Any one means or both means are provided.

Moreover, the steel plate heat treatment apparatus according to the present invention (Claim 5) is the steel plate heat treatment apparatus according to Claims 1 to 4, and can further bend the steel plate in which the inductor is wound a plurality of times. It is a solenoid coil having a shape, and the facing distance between the coil and the steel plate is narrow in the upper part and wide in the lower part in the coil.
The steel plate heat treatment apparatus according to the present invention (Claim 6) is the steel plate heat treatment apparatus according to any one of Claims 1 to 5, wherein the heat treatment unit has a width direction of the steel plate and a convex side upward. It is characterized by covering in an inverted V shape or a straight line with an inclination.

Moreover, the steel plate heat treatment apparatus (Claim 7) of the present invention is the steel plate heat treatment apparatus according to any one of Claims 1 to 6, further comprising a water discharger that discharges water to an end in the width direction of the steel plate. It is installed above the inductor while being fixed to the unit.
The steel plate heat treatment apparatus according to the present invention (Claim 8) is the steel plate heat treatment apparatus according to any one of Claims 1 to 6, wherein the heat treatment units are installed in a plurality of stages in the vertical direction, and each except for the lowest stage. The drainage part of the stage is provided with a draining part for preventing the water traveling through the steel sheet from dropping, and the upper part of the inductor is disposed above the uppermost inductor, and the drainer that discharges water to the end in the width direction of the steel sheet is the uppermost heat treatment unit. It is characterized by being provided in a fixed state.

  In such a steel plate heat treatment apparatus of the present invention (Claim 1), the steel plate is lifted and lowered while being held in a state in which the longitudinal direction thereof is oriented in the vertical direction. The internal stress generated in the steel sheet is mainly the compressive force due to its own weight when it is held in an allowable bending state, and this is much smaller than the bending stress when it is held sideways, so bending deformation due to its own weight is unlikely to occur. Become. Moreover, there is an advantage that the installation area of the apparatus can be reduced by the vertical type. In addition, since the inductor is disposed above and the water discharge unit is disposed below in the heat treatment unit in accordance with the vertical type, the heat treatment is performed when the steel sheet is lowered and is not performed when the steel plate is raised.

Further, in this steel plate heat treatment apparatus, a horizontal plane adjustment mechanism is introduced so that the position and in-plane orientation of the heat treatment unit including the inductor and the water discharge portion can be adjusted in the horizontal plane. Even if the steel plate is warped or twisted, it is possible to adjust the facing distance between the steel plate and the heat treatment unit by adjusting the position of the heat treatment unit, etc. The transfer and heat treatment of the steel sheet can be continued.
Therefore, according to the present invention, even if a heat treatment that sequentially applies induction heating and subsequent quenching to the steel plate while moving in the longitudinal direction while holding the steel plate of a finite length from both ends in a bending-permitted state, it is dependent on its own weight. It is possible to realize a steel plate heat treatment apparatus that is unlikely to be bent and can continue the heat treatment even if it is bent by the heat treatment.

  Moreover, in the steel plate heat treatment apparatus of the present invention (Claim 2), the opposing distance between the inductor and the steel plate is measured by a distance sensor, and by the follow-up control based on the detected distance data (displacement value detection value). By keeping the facing distance constant, the operation control of the horizontal adjustment mechanism necessary for continuing the heat treatment is automatically performed. In addition, at that time, since the measurement by the distance sensor is performed at a plurality of positions in the width direction of the steel sheet, it is possible to appropriately follow not only warpage deformation but also torsional deformation.

  Furthermore, in the steel plate heat treatment apparatus according to the present invention (Claim 3), the deformation detection means is provided to detect the deformation state of the steel plate, and the water discharge portion is divided into its longitudinal direction (width direction in the case of the steel plate). Since the deformation of the steel sheet is corrected by adjusting the amount of water discharged, the deformation that occurred in the steel sheet due to the previous heat treatment is canceled during the subsequent heat treatment, so the accumulation of bending deformation due to repeated heat treatment is suppressed. Is done.

  Further, in the steel plate heat treatment apparatus of the present invention (Claim 4), when the deformation detection means is embodied, the deformation state of the steel plate is detected based on the adjustment amount in the horizontal plane adjustment mechanism. The control distance sensor can be shared for deformation detection, and when the deformation detection means is embodied, a distance sensor is provided in the vicinity of the support member to detect the displacement of the end of the steel plate. It is possible to directly detect the deformation of the end portion of the steel material which is particularly easily deformed by the induction heating of the formula.

  In the steel plate heat treatment apparatus according to the present invention (Claim 5), the inductor is a solenoid coil, and the opposing distance between the inductor and the steel plate is narrow in the upper part of the coil and wide in the lower part. Therefore, when induction heating is performed when the steel sheet is lowered, local strong heating of the surface layer portion is performed on any part in the longitudinal direction of the steel sheet, and heating that is gradually spread and weakened is performed. For this reason, uniform heat input is reasonably performed up to the deep part, so that the deformation of the steel sheet can be reduced.

  Moreover, in the steel plate heat treatment apparatus (Claim 6) of the present invention, the heat treatment of the steel plate is spread from the center in the width direction to both sides, or from one end to the other end in the width direction. As the transition proceeds in the longitudinal direction, the heat treatment proceeds in order in the width direction instead of randomly (that is, proceeds in one direction with regularity maintaining a fixed positional relationship between the start and end sides of the heat treatment). Therefore, the deformation of the steel plate can be further reduced. In particular, in the case of an inverted V-shaped inductor, the progress in the width direction of the heat treatment becomes symmetrical, which is more preferable.

  Even if the shape of the inductor is adapted to the thickness and width of the steel plate, the corners of the steel plate of finite length are likely to be overheated during induction heating. However, in the steel plate heat treatment apparatus of the present invention (claim 7), Since the water discharger is provided on the upper side and can discharge water to the end in the width direction of the steel plate, it is possible to discharge the water from the water discharger when performing induction heating at the corner of the steel plate or the vicinity thereof. Excessive heat input to the water can be removed by simultaneous cooling to the corresponding location, and overheating can be prevented. In particular, water discharge to the end portion is useful for preventing the heat treatment cracking due to the overheating that is likely to occur at the heat treatment starting point in the longitudinal direction of the steel sheet.

  In the steel plate heat treatment apparatus of the present invention (Claim 8), the heat treatment units are installed in a plurality of stages in the vertical direction, so that rapid heating and quenching can be repeated more times than the number of movements of the steel plate, thereby improving efficiency. Even if the number of stages is increased, there is a drainage section between the upper water discharge section and the lower inductor, so that water can be prevented from falling from the upper water discharge section along the steel plate. Therefore, appropriate heat treatment is performed without impairing induction heating by the lower inductor.

  In addition, the combined use of induction heating in the entire region in the width direction and local cooling to the end as described above has the above-described effect of preventing overheating of the corners, but is undesirable because deformation tends to increase. In the steel plate heat treatment apparatus of the present invention (Claim 8), there is a side effect, and the water discharge to the end in the width direction of the steel plate is the same as the number of movements of the steel plate, and is less than the number of heat treatments. It is also possible to enjoy the further effect that the deformation is reduced.

  The configuration of a steel plate heat treatment apparatus according to an embodiment (first embodiment) of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic structure of a mechanical part of a steel plate heat treatment apparatus 10, wherein (a) is a front view and (b) to (d) are right side views. Moreover, FIG. 2 shows the support parts 15 and 16, (a) is a front view, (b)-(d) is a right view. 3 shows the arrangement of the distance sensors 21, 22, and 34, where (a) is a front view and (b) is a right side view. 4A is a plan view of the water discharger 43 and the inductor 32, FIG. 4B is a front view of the water discharger 43, the inductor 32 and the water discharger 33, and FIG. 4C is a water discharger. FIG. FIG. 5 is a block diagram of the electronic control unit 45, and FIG. 6 shows a water-cooled state, where (a) shows a water discharge situation during warping correction, and (b) shows a water discharge situation during twist correction.

  This steel plate heat treatment apparatus 10 is provided with a lifting motor 11, a fixed frame 12, a ball screw mechanism 13, a frame upper portion 14, an upper end support member 15, and a lower end in order to temporarily hold and move the finite length of the steel plate 9 in the longitudinal direction. A support member 16, a frame lower part 17, and a movable frame 18 are provided (see FIGS. 1 and 2). In order to perform rapid heat treatment and rapid heat treatment on the moving steel plate 9, a horizontal in-plane adjustment mechanism 31 and induction are provided. A child 32, a water discharger 33, a water discharger 43, a high-frequency power source and a water supply facility (not shown) are provided (see FIGS. 1 and 4), and a distance sensor 21, 22 and 34 and an electronic control unit 45 (see FIGS. 3, 5 and 6). Among them, the inductor 32, the water discharger 33, and the water discharger 43 are mutually fixed to form a heat treatment unit. Hereinafter, each part will be described in detail.

  The fixed frame 12 (see FIG. 1) is fixedly installed on the floor with the upper half rising from the floor surface 7 and the lower half under the floor 8 so that the upper frame body 14 and the lower frame body 17 can be moved up and down. The inner side is formed in a straight rail shape so as to support and also serve as a guide member for the movement. The frame upper part 14 and the frame lower part 17 are connected by a movable frame 18, and when the ball screw mechanism 13 is axially rotated by the elevating motor 11, they move up and down integrally. And such a support mechanism and a movable mechanism comprise the raising / lowering mechanism which moves the steel plate 9 to a longitudinal direction via the upper end support member 15 and the lower end support member 16. FIG.

A plurality of, for example, three lower end support members 16 are fixed upward on the lower portion 17 of the frame body, and only one upper end support member 15 is attached downward on the upper portion 14 of the frame body. By engaging the members 15 and 16 with both ends in the longitudinal direction of the steel plate 9, the steel plate 9 is held in a state in which the longitudinal direction is oriented in the vertical direction (hereinafter referred to as a vertically long state) and in an allowable bending state. It is like that.
That is, (see FIGS. 2A and 2B), in order to allow bending deformation of the steel plate 9, the upper end support member 15 and the lower end support member 16 are both in the form of elongated round bars and have a bending rigidity higher than that of the steel plate 9. It is small.

The lower end support member 16 supports the lower end of the steel plate 9 at a plurality of locations, thereby preventing free rotation of the steel plate 9 but substantially allowing bending deformation or the like in the width direction.
Further, the upper end support member 15 also supports bending deformation in the width direction of the steel plate 9 by supporting the center of the upper end of the steel plate 9 at a single location.
Furthermore, the upper end support member 15 is attached to the upper portion 14 of the frame so that it can be moved back and forth to some extent, that is, in a state in which some movement in the vertical direction is allowed, so that the thermal expansion of the steel plate 9 during processing is released ( 2 (c)), not only warping deformation but also torsional deformation of the steel plate 9 is permitted (see FIG. 2 (d)).

  The horizontal plane adjustment mechanism 31 (see FIG. 1) is fixed on the floor surface 7 and is installed on the side of the fixed frame 12, and supports the inductor 32 and the water discharger 33 of the heat treatment unit with arm-shaped members, By driving this arm-shaped member with a servo motor and a transmission mechanism (not shown), the heat treatment unit is moved in the horizontal plane, and the positions and in-plane orientations of the inductor 32, the water discharger 33, and the water discharger 43 that form the heat treatment unit. Are adjusted (see FIG. 4A). The inductor 32 (see FIGS. 1, 4A and 4B) is made of a good electrical conductor such as a water-coolable copper tube and wound around a hoistway of the steel plate 9 by being wound into a solenoid coil shape. When a high frequency is applied from a high frequency power source (not shown) through a cable or a transformer (not shown), the opposite portion of the steel plate 9 is induction heated.

  Further, since the inductor 32 is for moving heating, with respect to the facing state with respect to the steel plate 9, it faces the steel plate 9 in the entire width direction of the steel plate 9, and the steel plate 9 in a part of the longitudinal direction of the steel plate 9. It comes to confront with. When the steel plate 9 is placed at the winding center of the inductor 32 (see FIG. 4 (a)), the inductor 32 and the steel plate 9 are parallel to each other in most of the width direction of the steel plate 9, and the opposite distance between them. The inductor 32 is formed so that is constant. However, at both ends in the width direction of the steel plate 9, the inductor 32 is configured to escape so as to increase the opposing distance between them in order to prevent overheating.

  The water discharger 43 (see FIGS. 4A and 4B) is attached above the inductor 32. Since the water discharger 43 is used in combination with induction heating in the inductor 32 in order to prevent overheating of the corner of the steel plate 9, that is, the end in the width direction of the steel plate 9 and also the end in the longitudinal direction, 9 is provided only in the vicinity of both ends in the width direction, and the water discharge direction is directed to the end in the width direction of the steel plate 9. The water discharge from the water discharger 43 is performed according to the water supply to the water discharger 43 from the water supply equipment through which the water supply tool 44 including a water stop valve and an electromagnetic valve is interposed, and the water supply is electromagnetic according to the control of the electronic control unit 45. It is performed according to the opening and closing of the valve.

  The water discharger 33 (see FIGS. 1, 4 (b), (c)) is provided below the inductor 32 in order to perform rapid cooling after rapid heating of the descending steel plate 9, and also with the steel plate 9. In the width direction, the entire region is confronted with a part of the section in the longitudinal direction. This water discharge part 33 (refer FIG.4 (c)) is divided into the longitudinal direction, ie, the width direction of the steel plate 9, (in FIG.4 (c), eight front and back each), Furthermore, it stops with respect to each division body 33a. The water supply tool 33b which consists of a water valve and a solenoid valve is connected. And if a solenoid valve opens and closes according to control of the electronic control apparatus 45 for every division body 33a, the water discharge state (execution / stop) of the water discharge part 33 will switch.

  Further, some of the sections 33a (six sections on each side in FIG. 4C) can adjust the water discharge amount by the flow rate adjusting valve 33c according to the control of the electronic control device 45. The flow rate adjusting valve 33c may be provided for each of the divided bodies 33a and the water supply tools 33b, but here, the flow rate adjusting valve 33c is shared by two adjacent sections (in FIG. 4C, the front and back sides). 3 each). A plurality of injection holes are formed in each section 33a in a row in the width direction of the steel plate 9, and at the time of water discharge, cooling water adjusted to an appropriate amount is sprayed toward the steel plate 9 from each injection port. It has become.

  The distance sensors 21, 22, and 34 (see FIG. 3) may be appropriate proximity sensors as long as they can measure up to about several tens of millimeters. However, they are preferably resistant to water and dirt, and for example, waterproof proximity sensors are suitable. Among them, two distance sensors 21 are attached to the upper portion 14 of the frame with appropriate support columns, and detect displacement in the thickness direction of both corners of the upper end of the steel plate 9. Two distance sensors 22 are attached to the lower portion 17 of the frame with appropriate support columns, and detect displacement in the thickness direction at both corners at the lower end of the steel plate 9. The distance sensor 34 is provided in each of two locations separated in the width direction of the steel plate 9, and both are attached in a state of being fixed to the inductor 32, and the opposing distance between the inductor 32 and the steel plate 9 is determined. Measurement is made at two locations in the width direction.

  Such a distance sensor 34 moves relative to the longitudinal direction of the steel plate 9 when the steel plate 9 is raised or lowered, but the distance sensors 21 and 22 are provided in the vicinity of the support members 15 and 16 and move together therewith. Even if the steel plate 9 moves up and down, it does not move relative to the longitudinal direction of the steel plate 9. In addition, the distance data (displacement value detection values) measured by these distance sensors 21, 22, and 34 are sent out via an appropriate signal cable or the like at any time, via an appropriate signal input circuit or A / D conversion circuit. In this way, the electronic control unit 45 can be taken in.

The electronic control unit 45 (see FIG. 5) is composed of a programmable computer or sequencer, and is installed with a follow-up control program, a bending detection program, a twist detection program, a water amount adjustment program, a feed control program, an energization control program, and the like.
The follow-up control program keeps the facing distance between the inductor 32 and the steel plate 9 constant by operating the horizontal adjustment mechanism 31 in a direction to cancel the fluctuation based on the distance data (displacement amount detection value) of the distance sensor 34. It is like that. This is a program that works when the steel plate 9 is raised or lowered.

  The bending detection program is one of deformation detection means for detecting the deformation state of the steel plate 9, and the deformation state of the steel plate 9 is determined based on the adjustment amount (that is, position data and in-plane orientation data) in the horizontal plane adjustment mechanism 31. It is something to detect. When the steel plate 9 is raised, the amount of adjustment is stored for the entire area in the longitudinal direction of the steel plate 9, and before the next lowering of the steel plate 9, that is, before the heat treatment, the longitudinal deformation or warpage deformation of the steel plate 9 by frequency analysis calculation or the like. The data is extracted and handed over to the water control program. In addition, when it is desired to obtain data of bending deformation in the width direction of the steel plate 9, the distance sensor 34 is fixed to the inductor 32 and installed at three or more locations in the width direction of the steel plate 9, for example, two-dimensional fast Fourier transform. What is necessary is just to perform expansion, such as extracting data in two directions by conversion.

  The torsion detection program is also one of deformation detection means for detecting the deformation state of the steel plate 9, but this program is based on the displacement amount (distance data) of the end of the steel plate 9 detected by the distance sensors 21 and 22. The deformation state of the steel plate 9 is detected. Since the lower end of the steel plate 9 is supported by a plurality of lower end support members 16 and the rotation about the vertical axis is stopped, the displacement difference between both corners at the upper end in the longitudinal direction of the steel plate 9 measured by the two distance sensors 21 ( The difference in distance data) is calculated to obtain data on the overall torsional deformation of the steel plate 9, and the average of the detected displacements is taken to obtain the bending deformation in the width direction at the upper end in the longitudinal direction of the steel plate 9. The data of the bending deformation in the width direction at the lower end in the longitudinal direction of the steel plate 9 is calculated by calculating the average of the displacement of both corners at the lower end in the longitudinal direction of the steel plate 9 measured by the two distance sensors 22. I'm also asking for. Such deformation data can be obtained at any time. For example, data before the steel plate 9 is lowered is delivered to the water amount adjustment program.

  The water amount adjustment program adjusts the water discharge amount of the water discharge unit 33 based on the deformation data received from the bending detection program and the twist detection program by the control of the flow rate adjustment valve 33c. The amount of water on the concave side is increased to increase the amount of water on the side. The amount of increase / decrease is adjusted according to the curvature, which is the degree of deformation, and the amount of correction of warpage deformation (see FIG. 6A) and the amount of correction of twist deformation (see FIG. 6B) are superimposed. Is done. As for the correction of the warp deformation, the correction of the bending deformation in the longitudinal direction of the steel plate 9 and the correction of the bending deformation in the width direction at the upper end or the lower end of the steel plate 9 are included.

The feed control program includes a setup mode and a heat treatment mode as selectable operation modes. In the setup mode, the movable mechanisms 14 to 18 are raised to the top, and the upper end of the lower end support member 16 is moved from the inductor 32. The state of protruding upward is maintained. In the heat treatment mode, the lifting motor 11 is controlled to move the steel plate 9 up and down at a constant speed and cycle. The speed and cycle can be changed by parameter setting.
The energization control program sends a command to the high-frequency power source, energizes the inductor 32 with high frequency to perform heat treatment when the steel plate 9 descends, and stops energization otherwise. In order to prevent overheating of the corners of the steel plate 9, the water supply tool 44 is also controlled so that when the steel plate 9 starts to descend, water is temporarily discharged from the water discharger 43 to both ends in the width direction of the steel plate 9 for about 7 seconds, for example. It has become.

About the steel plate heat processing apparatus 10 of this embodiment (1st form), the use aspect and operation | movement are demonstrated.
The material of the steel plate 9 to be processed by the steel plate heat treatment apparatus 10 is typically JIS G3128 (SHY) or JIS G4103 (SNCM). However, as long as crystal grains are refined by repeated rapid heating and rapid cooling. Another thing may be sufficient (for example, refer patent documents 1-3).

  The size of the steel plate 9 is typically about 22 mm thick × 1200 mm wide × 3500 mm long, but other sizes (9-25 mm × 900-1500 mm × as a guideline) can be held from both ends in a vertically long state. About 1500 to 6000 mm). If the inductor 32 and the water discharger 33 suitable for the size of the steel plate 9 are mounted on the horizontal plane adjustment mechanism 31, they are used as they are, but if they are not compatible, the inductor 32 and the water discharger 33 are used as a steel plate. It is exchanged for one that conforms to 9. Depending on the size of the steel plate 9, the installation position of the water discharger 43 and the installation position of the upper end support member 15 are also adjusted. Values suitable for the size and material of the steel plate 9 are selected for the energizing current of the inductor 32, its frequency, the average water discharge amount of the water discharge section 33, and the parameters are set in the electronic control unit 45. As a typical example, the high-frequency current is 980 A, the voltage is 590 V, and the frequency is 2.2 kHz.

  After the initial setting and adjustment of the steel plate heat treatment apparatus 10, the feed control program of the electronic control unit 45 is set to the setup mode. Then, since the movable mechanisms 14 to 18 are sufficiently raised and stopped, the lower end of the vertically long steel plate 9 is placed on the tip of the lower end support member 16 protruding upward from the inductor 32, and then the upper end of the upper end of the steel plate 9 is The support member 15 is engaged to hold the steel plate 9 (see FIG. 1C). In order to prevent the engagement between the steel plate 9 and the support member 15, it is preferable that the engagement portions at both ends of the steel plate 9 are formed with depressions or perforated in advance.

  When the steel plate 9 is thus held in the vertically long state and in the bending-permitted state, the feed control program of the electronic control unit 45 is set to the heat treatment mode. Then, the steel plate 9 is lowered at a constant speed (see FIGS. 1A and 1B). At that time, the follow-up control of the electronic control unit 45 based on the distance data of the distance sensor 34 (detection value of the displacement amount) is also performed, and the horizontal plane adjustment mechanism 31 adjusts the position and the in-plane orientation of the heat treatment unit accordingly. The facing distance between the inductor 32 and the water discharger 33 and the steel plate 9 is kept constant. Moreover, the water discharger 43, the inductor 32, and the water discharge part 33 start operation | movement in the place about 50 mm above the lower end of the steel plate 9, for example.

  Among them, water discharge from the water discharger 43 to both ends in the width direction of the steel plate 9 is performed for about 7 seconds and stopped. This temporary and local water cooling prevents burning cracks and large deformations at the lower end of the steel plate 9. The rapid heating due to the high-frequency energization of the inductor 32 and the rapid cooling due to the water discharge from the water discharge portion 33 are continued throughout the entire width direction of the steel plate 9 until the steel plate 9 is completely lowered (see FIG. 1D). In the first heat treatment, since the amount of water discharged from the water discharger 33 is not adjusted, uniform water discharge is performed from the respective sections 33a of the water discharger 33. In addition, what is necessary is just to make the steel plate 9 reciprocate once in the idling | feeding state which does not involve heat processing, when adjusting the amount of discharged water from the first heat processing.

For example, at about 50 mm to a few tens of mm below the upper end of the steel plate 9, the energization to the inductor 32 is stopped, the water discharge of the water discharge portion 33 is stopped, and the first heat treatment is finished. It is desirable to shift the end position of the heat treatment every time to prevent burning cracks.
If it goes down, it will turn up and the steel plate 9 will move at a constant speed. At the time of rising, no heat treatment is performed, but follow-up control is performed to keep the facing distance between the inductor 32 and the water discharger 33 and the steel plate 9 constant, and data of the adjustment amount of the horizontal plane adjustment mechanism 31 at that time is also recorded. Is called.

Then, when it has risen, warp deformation data of the steel sheet 9 is obtained by the bending detection program, and overall torsion deformation data of the steel sheet 9 and width direction bending deformation data of the upper and lower ends are also obtained by the torsion detection program.
If it rises, it will turn down and the steel plate 9 will move at a constant speed. At the time of descending, the follow-up control and the heat treatment described above are performed, but the water discharge amount of the water discharge section 33 is adjusted in the second and subsequent heat treatments. The adjustment of the water discharge amount is performed by increasing / decreasing the water discharge amount for each section 33a based on the deformation data obtained earlier, and the deformation of the steel plate 9 is corrected (see FIG. 6).

Although the detailed description to be repeated is omitted, the above-described processing is repeated according to the parameter setting, so that rapid heating by induction heating and rapid cooling by water cooling are repeated while moving the steel plate 9 in the longitudinal direction. 9 crystal grains are refined.
Thus, when the desired heat treatment is completed and the temperature of the steel plate 9 is lowered, the feed control program of the electronic control device 45 is set to the setup mode, the processed steel plate 9 is removed from the steel plate heat treatment device 10, and the next steel plate 9 is present. If so, proceed with the setup and processing.

The configuration of another embodiment (second embodiment) of the steel plate heat treatment apparatus of the present invention will be described with reference to the drawings. 7A and 7B show the structure of the inductor 47, where FIG. 7A is a front view and FIG. 7B is a right side view of a partial cross section.
This steel plate heat treatment apparatus is different from the steel plate heat treatment apparatus 10 described above in that an inductor 47 is introduced instead of the inductor 32. The inductor 47 is different from the inductor 32 in that the number of coil windings is " The point increasing from “2” to “4” is that the opposing distance between the inductor 47 and the steel plate 9 is narrow in the upper part of the coil and wide in the lower part.

  In this case, since the facing distance between the inductor 47 and the steel plate 9 is narrow in the upper portion of the coil and wide in the lower portion, at the induction heating performed when the steel plate 9 is lowered, in any part in the longitudinal direction of the steel plate 9 On the other hand, after local strong heating of the surface layer portion is performed by the upper portion of the inductor 47, while the heat is transmitted to the deep portion and the like, it is gradually spread and weakened. This is done by the lower part of the inductor 47. Thereby, since it can heat to a deep part, avoiding overheating of a surface layer part, while a reforming capability improves, a deformation | transformation of a steel plate is suppressed.

The configuration of another embodiment (third embodiment) of the steel plate heat treatment apparatus of the present invention will be described with reference to the drawings. FIG. 8 is a front view showing the structure of the inductor 48 in both (a) and (b).
This steel plate heat treatment apparatus is different from the steel plate heat treatment apparatus 10 described above in that an inductor 48 is introduced instead of the inductor 32, and the inductor 48 in FIG. 8A is different from the inductor 32. The number of coil strokes is increased from “2” to “4”, and they are all in an inverted V shape with the convex side facing upward. 8B is different from the inductor 32 in that the number of coil windings is increased from “2” to “4” and they are both linearly inclined. It is a point. Although not shown in the figure, the water discharger 33 is also shaped like an inverted V or an inclined straight line like the inductor 32.

  In this case, when induction heating and subsequent water cooling are performed when the steel plate 9 is lowered, the heat treatment spreads from the center in the width direction of the steel plate 9 to both sides (see FIG. 8A), or a heat treatment site. Since the heat treatment proceeds in the longitudinal direction of the steel plate 9 while shifting from one end side to the other end side in the width direction of the steel plate 9 (see FIG. 8B), deformation of the steel plate 9 can be reduced. Note that the upwardly convex shape is not limited to a polygonal line shape such as the illustrated “∧” shape, but may be a curved shape such as a “∩” shape. In addition, it is better to combine the inductor 47 with the feature of the inductor 47 that the opposing distance between the steel plate 9 and the solenoid coil-shaped inductor 48 is narrow in the upper part of the coil and wide in the lower part.

  The configuration of another embodiment (fourth embodiment) of the steel plate heat treatment apparatus of the present invention will be described with reference to the drawings. FIG. 9 shows a schematic structure of the mechanical part of the steel plate heat treatment apparatus 50, where (a) is a front view and (b) is a right side view. FIG. 10 shows the arrangement of the distance sensor 55, where (a) is a front view and (b) is a right side view. 11A is a plan view of the water discharger 43 and the inductor 52, and FIG. 11B is a plan view of the water discharger 43, the inductor 52, the water discharger 53, the drainer 54, the inductor 32, and the water discharge. The front view of the part 33, (c) is a plan view of a partial cross section of the water discharge part 53. FIG. 12 is a cross-sectional view of a main part of the draining portion 54. FIG. 13 is a block diagram of the electronic control unit 45.

  The main difference between the steel plate heat treatment apparatus 50 and the steel plate heat treatment apparatus 10 described above is that the horizontal plane is similar to the combination mechanism (first set) of the in-horizontal adjustment mechanism 31, the inductor 32, the water discharger 33, and the distance sensor 34. This is that a combination mechanism (second set) including the inner adjustment mechanism 51, the inductor 52, the water discharger 53, and the distance sensor 55 is added upward. This additional mechanism (second set) is also different in that a draining portion 54 is attached and that the water discharger 43 is moved from above the inductor 32 to above the inductor 52. Accordingly, the function of the electronic control unit 45 has been expanded. Hereinafter, the differences will be described in detail.

The horizontal plane adjustment mechanism 51 may have the same structure as the horizontal plane adjustment mechanism 31 or a different structure as long as the position, in-plane orientation can be adjusted by horizontally moving the inductor 52, the water discharge portion 53, and the draining portion 54. good.
The inductor 52 may be the same as the inductor 32 as long as the inductor 52 can rapidly heat the steel plate 9 when energized by confronting the steel plate 9 in the width direction across the entire region and in a partial section in the longitudinal direction. 47 and 48 may be the same or different. The high frequency power source for supplying power to the inductor 52 may be shared with the inductor 32, or a separate one may be additionally installed.

If the water discharger 53 is provided below the inductor 52 and confronts the steel plate 9 in the width direction over the entire region and confronts in a partial section in the longitudinal direction, the steel plate 9 is rapidly cooled at the time of water discharge. Basically, it is good, but from the viewpoint of correcting the deformation of the steel plate 9 without difficulty, the water discharge amount can be adjusted for each section similar to the water discharge section 33 (see FIG. 11C).
The distance sensors 55 are provided at two positions in the width direction of the steel plate 9 in a state of being fixed with respect to the inductor 52 (see FIG. 10), and measure the facing distance between the inductor 52 and the steel plate 9, respectively. As long as the distance sensor 34 is used, the same structure or a different structure may be used.

  The draining portion 54 (FIGS. 11B and 12) has an umbrella-shaped lower end portion, and is attached directly below the water discharge portion 53 in a state where the upper end portion is connected to the lower end of the water discharge portion 53. This is provided with a slide seal that slides freely on the upper surface of the draining portion 54. In the slide seal, for example, a rubber seal 54b is attached to the tip of the slider 54a, and air (compressed air) is blown into the gap 9a between the rubber seal 54b and the steel plate 9 with a flexible tube. This prevents friction between the draining portion 54 and the steel plate 9 and prevents the cooling water 46 sprayed from the water discharge portion 53 toward the steel plate 9 from entering the gap 9a through the steel plate 9. Is also prevented from falling to the heated part of the inductor 32. The cooling water 46 of the water discharge part 53 flows out of the drain outlet etc. of the upper surface of the draining part 54, flows on the inclined surface of the draining part 54, and is discharged | emitted outside (the dotted line with an arrow of FIG. 12 is shown). reference).

  The electronic control device 45 (see FIG. 13) is additionally installed with another follow-up control program, and is guided by operating the horizontal plane adjustment mechanism 51 based on the distance data (detection value of the displacement) of the distance sensor 55. Follow-up control is also performed to keep the facing distance between the child 52 and the steel plate 9 constant. Further, the bending detection program reduces the error by using, for example, the average value of the adjustment amounts of the horizontal plane adjustment mechanisms 31 and 51 as the basis of the deformation data calculation, and the torsion detection program detects the steel plate 9 from the adjustment amount of the horizontal plane adjustment mechanism. The local torsion amount in each part in the longitudinal direction is also calculated and added to the data of the overall torsional deformation. In addition to the child 32, the current supply to the inductor 52 is also controlled.

  About the steel plate heat processing apparatus 50 of this embodiment (4th form), the use aspect and operation | movement are demonstrated. Since it is basically the same as that of the steel plate heat treatment apparatus 10, the differences will be mainly described here.

  In the steel plate heat treatment apparatus 50, the set of the inductor and the water discharge portion is arranged in two stages, so that the heat treatment is performed twice each time the steel plate 9 is reciprocated once. The first heat treatment is performed by the inductor 52 and the water discharger 53, and the second heat is performed by the inductor 32 and the water discharger 33, both of which are rapid heating by mobile induction heating and rapid cooling by water cooling. Contributes to refinement of crystal grains. At that time, since the follow-up control of the inductor 52 and the follow-up control of the inductor 32 are performed independently, the opposing distance from the steel plate 9 is kept constant in both cases.

  However, if bending deformation or the like occurs in the steel plate 9 due to the previous heat treatment or the like, the facing distance slightly changes in a portion other than the measurement location, but in such a place, the slider 54a moves and the rubber seal 54b and Since the gap 9a with the steel plate 9 is maintained constant, the cooling water 46 does not enter the gap 9a from the upper water discharge portion 53 through the steel plate 9, and the cooling water 46 may flow down from there. Absent. Then, not only the preceding heat treatment by the inductor 52 and the water discharger 53 but also the subsequent heat treatment by the inductor 32 and the water discharger 33 are appropriately performed.

Further, based on deformation data obtained by measurement or the like when the steel plate 9 is raised, water amount adjustment for deformation correction is performed when the steel plate 9 is lowered. In the case of the steel plate heat treatment apparatus 50, the water amount adjustment is performed by the water discharger 33 and the water discharge. Since the performance is shared by the unit 53, the adjustment capability is improved.
Further, water discharge from the water discharger 43 to the end in the width direction of the steel plate 9 is also performed only immediately after the start of heat treatment in order to prevent burning cracks at the lower end of the steel plate 9, but in the case of the steel plate heat treatment apparatus 50, the inductor Since it is used only for the preceding rapid heating by 52 and is performed after a short time without cooling to the deep part of the steel plate 9, it is not used for the rapid heating in the inductor 32 without fear of burning cracks. Undesirable deformation caused by the combined use can be reduced.
[Others]

About one Embodiment (1st form) of this invention, the schematic structure of the machine part of a steel plate heat processing apparatus is shown, (a) is a front view, (b)-(d) is a right view. About a support part, (a) is a front view, (b)-(d) is a right view. The arrangement of the distance sensor is shown, (a) is a front view, and (b) is a right side view. About a heat processing part, (a) is a top view of a water discharger and an inductor, (b) is a front view of a water discharger, an inductor, and a water discharge part, (c) is a top view of a partial section of a water discharge part. It is a block diagram of an electronic control unit. A water-cooled state is shown, (a) is during warp correction, and (b) is during twist correction. About other embodiment (2nd form) of this invention, the structure of an inductor is shown, (a) is a front view, (b) is a right view of a partial cross section. (A), (b) is a front view which shows the structure of an inductor about other embodiment (3rd form) of this invention. About other embodiment (4th form) of this invention, the schematic structure of the machine part of a steel plate heat processing apparatus is shown, (a) is a front view, (b) is a right view. The arrangement of the distance sensor is shown, (a) is a front view, and (b) is a right side view. About a heat processing part, (a) is a top view of a water discharger and an inductor, (b) is a front view of a water discharger, an inductor, and a water discharge part, (c) is a top view of a partial section of a water discharge part. It is sectional drawing of the principal part of a draining part. It is a block diagram of an electronic control unit.

Explanation of symbols

7 ... floor surface, 8 ... under the floor, 9 ... steel plate,
10 ... Steel plate heat treatment device,
11 ... Lifting motor, 12 ... Fixed frame, 13 ... Ball screw mechanism,
14 ... upper part of frame body, 15 ... upper end support member, 16 ... lower end support member,
17 ... lower part of frame body, 18 ... movable frame, 21, 22 ... distance sensor,
31 ... Horizontal plane adjustment mechanism, 32 ... Inductor, 33 ... Water discharge part, 33a ... Partition body,
33b ... Water supply tool, 33c ... Flow rate adjusting valve, 34 ... Distance sensor, 43 ... Water discharger,
44 ... Water supply device, 45 ... Electronic control device, 46 ... Cooling water, 47,48 ... Inductor,
50 ... Steel plate heat treatment device,
51 ... Horizontal plane adjustment mechanism, 52 ... Inductor, 53 ... Water discharge part, 54 ... Draining part,
54a ... slider, 54b ... rubber seal, 54c ... tube, 55 ... distance sensor

Claims (8)

Inductive heating and subsequent quenching are sequentially applied to the steel sheet while moving the steel sheet in the longitudinal direction for the grain refinement process that is performed by repeatedly performing a heat treatment that applies rapid heating and subsequent quenching to the steel sheet. In the steel plate heat treatment apparatus, the steel plate is made of a rod-like member having a bending rigidity smaller than that of the steel plate, and is engaged with both ends in the longitudinal direction of the steel plate to hold the steel plate in a state in which the longitudinal direction is oriented in the vertical direction and in an allowable bending state. A support member, an elevating mechanism for moving the steel plate in the longitudinal direction via the support member, and a width direction of the steel plate for induction heating of the steel plate so as to face the entire region in the longitudinal direction and to face a section in the longitudinal direction. And a water discharge section for quenching the steel plate disposed so as to face a part of the section in the longitudinal direction across the entire width direction of the steel plate below the inductor. Heat treatment unit If, steel thermal processing apparatus characterized by and a horizontal plane adjusting mechanism for adjusting the position and the in-plane orientation of the thermal processing unit is moved in a horizontal plane.   A distance sensor for measuring a facing distance between the inductor and the steel plate is installed at a plurality of positions in the width direction of the steel plate in a state of being fixed to the inductor, and the horizontal plane adjustment mechanism is set based on the data. 2. The steel plate heat treatment apparatus according to claim 1, wherein follow-up control is performed to keep the facing distance constant by operating.   The water discharge part is sectioned in the longitudinal direction, and some of the sections are capable of adjusting the water discharge amount, provided with a deformation detection means for detecting the deformation state of the steel sheet, and correcting the deformation. The steel sheet heat treatment apparatus according to claim 2, wherein the water discharge amount of the water discharge section is adjusted so as to perform.   As the deformation detection means, a means for detecting the deformation state of the steel sheet based on an adjustment amount by the adjustment mechanism in the horizontal plane, and a steel sheet detected by a distance sensor provided in the vicinity of the support member and moving therewith. 4. The steel plate heat treatment apparatus according to claim 3, wherein either one or both of means for detecting a deformation state of the steel plate based on a displacement amount of the end portion is provided.   The inductor is wound a plurality of times, and is a solenoid coil having a shape capable of bending the steel plate, and the facing distance between the inductor and the steel plate is narrow in the upper part and wide in the lower part. The steel plate heat treatment apparatus according to any one of claims 1 to 4.   6. The heat treatment unit according to claim 1, wherein the heat treatment unit covers the width direction of the steel plate in an inverted V shape with the convex side facing upward or a straight line with an inclination. Steel plate heat treatment equipment described in 1.   The water discharger which discharges water to the edge part of the width direction of the said steel plate is installed in the upper direction of the said inductor in the state fixed to the said heat processing unit, The Claim 1 thru | or 6 characterized by the above-mentioned. Steel plate heat treatment equipment.   The heat treatment unit is installed in a plurality of stages in the vertical direction, the drainage part of each stage excluding the lowermost stage is provided with a draining part for preventing the water traveling down the steel sheet, and the upper part of the inductor is disposed above the inductor. The steel plate heat treatment apparatus according to any one of claims 1 to 6, wherein a water discharger for discharging water to an end portion in the width direction is provided in a state of being fixed to the uppermost heat treatment unit.

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