JP5887884B2 - Electric heating device - Google Patents

Description

  The present invention relates to an electric heating device for energizing a workpiece such as a steel material.

  A member requiring strength such as a structure of an automobile such as a center pillar or reinforcement is subjected to heat treatment. Types of heat treatment include indirect heating and direct heating. Indirect heating includes so-called furnace heating in which a workpiece is housed in a furnace and heated by controlling the temperature of the furnace. The direct heating includes so-called dielectric heating, in which heating is performed by passing an eddy current through the workpiece, and so-called energization heating, in which heating is performed by passing a current directly through the workpiece.

  Patent Document 1 discloses that induction heating or energization heating is performed while passing through a metal material by a heating means in a preceding stage of a processing means for plastically processing a difficult-to-work metal material. According to this, a heating means including an induction heating coil or an electrode roller is disposed in front of the processing means provided with the cutter device, and the metal material is continuously conveyed and heated by the electrode roller.

  In order to heat-treat a flat steel material having a substantially equal depth width in the left-right direction by energization, one electrode is disposed on each of the left end portion and the right end portion of the steel material, and a voltage is applied between the electrodes. Since a uniform current flows through the steel material, the calorific value is uniform regardless of the part of the steel material.

  However, in the case of plate-like steel materials with different depth widths in the left and right direction, a plurality of electrodes are arranged side by side at the left end of the steel material, a plurality of electrodes are arranged side by side at the right end of the steel material, and the left and right ends of the steel material are arranged. A pair is constituted by the arranged electrodes, and the steel material is heated to a uniform temperature by flowing an equal current between each pair of electrodes. Such a technique is disclosed in Patent Document 2, for example.

  Although it is not a plate-shaped steel material, the technique which energizes and heats a steel bar is disclosed by patent document 3, According to it, one electrode is fixed to the end of a steel bar, and heating is carried out among steel bars. By sandwiching a clamp-type electrode between the necessary part and the unnecessary part, the steel bar can be partially heated.

Japanese Patent No. 3587501 Japanese Patent Laid-Open No. 06-79389 JP-A-53-7517

  When heat-treating steel materials having different depth widths in the left and right direction among the workpieces, it is desirable that the amount of heat applied per unit volume of the steel material does not vary from place to place of the steel material as in furnace heating. However, when a heating device such as a furnace is used, the heating furnace is not only large, but also it is difficult to control the temperature of the furnace.

  Therefore, as disclosed in Patent Documents 1 to 3, heating by energization is preferable in terms of production cost. However, as in Patent Document 1, in order to provide a plurality of electrode pairs and control the energization amount to each electrode pair, the energization amount must be controlled for each electrode pair. It is not preferable. Moreover, since it is necessary to arrange | position several electrode pairs with respect to one workpiece | work, productivity also worsens.

  Moreover, when heating so that it may have a fixed temperature distribution, it is necessary to arrange | position several electrode pairs to one workpiece | work, but the same subject also exists in this case.

  Therefore, an object of the present invention is to provide an energization heating apparatus that does not need to provide a plurality of electrode pairs when uniformly heating a workpiece or heating a workpiece with a predetermined temperature distribution.

In order to achieve the above object, the present invention provides an electrode pair that is electrically connected to a power feeding unit, and that is in a state in which one electrode and the other electrode are in contact with a workpiece while the one electrode and the other electrode are in contact with the workpiece. A moving mechanism that moves one or both of one electrode and the other electrode to change the distance between the one electrode and the other electrode in a state where the work is energized from the part via the electrode pair, provided, the moving mechanism, Ru includes an adjusting unit that controls the moving speed of the electrode to be moved out of the one electrode and the other electrode, and a driving mechanism for moving the electrode to be moved by the adjustment unit.
In this case, preferably, one electrode and the other electrode have a length that crosses a region to be heated of the workpiece.
Adjustment unit obtains the moving speed of the electrode to be moved from the data about the shape and dimensions of the workpiece, the drive mechanism moves the electrodes to be moved by the calculated moving speed.
Both the one electrode and the other electrode include an electrode part and an auxiliary electrode part that sandwich the workpiece from above and below, and a lead part to which wiring from the power feeding part is connected and the electrode part is energized.
Either one of the electrodes or the other electrode may be a moving electrode that moves by a moving mechanism, or both the one electrode and the other electrode may move by a moving mechanism. The moving electrode has means for rolling or sliding while in contact with the area of the workpiece to be heated.

  According to the present invention, when the region to be heated of the workpiece is virtually divided into strips along the moving direction of the electrode, the amount of heat applied to the divided region can be reduced according to the moving direction of the electrode.

Therefore, as a first, the resistance per unit length along one direction of the region to be heated of the workpiece changes on the left and right. For example, when the cross-sectional area increases or decreases in one direction, One electrode and the other electrode are arranged and at least one electrode is moved in a direction in which the resistance per unit length along one direction increases in an energized state. At that time, the moving speed of the electrode is adjusted in accordance with the increase in resistance per unit length along one direction. Thereby, the electric quantity for each region virtually divided into strips in the moving direction is set to a range having the same identity regardless of each region. As a result, even if the resistance per unit length along one direction is changing, for example, when the cross-sectional areas are different in the left-right direction, a large number of electrode pairs are not arranged and applied to each region. The amount of heat can be made equal, and the heating region can be heated almost uniformly.

  Second, in the case where the heating is performed so that the region to be heated of the workpiece has a predetermined temperature distribution, for example, the cross-sectional area is substantially constant and the temperature distribution is from one temperature to the other in a single direction. By moving at least one electrode in one direction, the electric quantity of the region virtually divided into strips in the moving direction is made different for each region to have a predetermined temperature distribution be able to.

The concept of the electric heating apparatus which concerns on 1st Embodiment of this invention is shown, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c) is after electricity supply. The top view of a state and (d) are the front views of the state after electricity supply. It is a figure for demonstrating the basic relational expression in direct electricity supply. It is a front view which shows the specific structure of the electric heating apparatus shown in FIG. It is a left view which shows the specific structure of the electric heating apparatus shown in FIG. It is a top view which shows a part of specific structure of the electric heating apparatus shown in FIG. It is a right view which shows the specific structure of the electric heating apparatus shown in FIG. The concept of the electric heating apparatus which concerns on 2nd Embodiment of this invention is shown, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c) is after electricity supply. The top view of a state and (d) are the front views of the state after electricity supply. The concept of the electric heating apparatus which concerns on 3rd Embodiment of this invention is shown, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c) is during electricity supply. (D) is a front view of the state during energization, (e) is a plan view of the state after energization, and (f) is a front view of the state after energization. The concept of the electric heating apparatus which concerns on 4th Embodiment of this invention is shown, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c) is after electricity supply. The top view of a state and (d) are the front views of the state after electricity supply. The concept of the electric heating apparatus which concerns on 5th Embodiment of this invention is shown, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c) is after electricity supply. The top view of a state and (d) are the front views of the state after electricity supply. The concept of the electric heating apparatus which concerns on 6th Embodiment of this invention is shown, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c) is after electricity supply. The top view of a state and (d) are the front views of the state after electricity supply.

  Hereinafter, several embodiments of the present invention will be described with reference to the drawings. In the present invention, the energization heating device can naturally be applied even to a workpiece whose thickness is constant and the depth width does not change along the left-right direction, but the region to be heated of the workpiece (hereinafter referred to as “heating region”). Workpieces whose cross-sectional area has decreased due to changes in depth width and thickness along one of the left and right sides, and there are openings and cutout areas in the heating area. It is also applicable to a workpiece in which the dimension of the cross section perpendicular to the direction is reduced. The material of the workpiece is, for example, a steel material that is energized and heated by passing an electric current, and includes a single member or a member in which members having different resistivity are integrated by welding. Moreover, a plurality of areas may be set in addition to a case where only one heating area is set for the work. In that case, the plurality of regions may be adjacent to each other or may be separated from each other.

[First Embodiment]
FIG. 1: has shown the concept of the electric heating apparatus which concerns on 1st Embodiment of this invention, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c). Is a plan view of the state after energization, and (d) is a front view of the state after energization.

  The energization heating apparatus 10 according to the first embodiment of the present invention is electrically connected to the power feeding unit 1, and includes an electrode pair 13 including one electrode 11 and the other electrode 12, and one electrode 11 and the other electrode 12. The moving mechanism 15 which moves any one or both of these is provided.

  The moving mechanism 15 moves one electrode 11 while the one electrode 11 and the other electrode 12 are in contact with the work w and the work w is energized from the power supply unit 1 via the electrode pair 13. Thus, the distance between one electrode 11 and the other electrode 12 is changed.

  In the embodiment shown in FIG. 1, since the moving mechanism 15 moves one electrode 11, one electrode 11 is called a moving electrode, and the other electrode 12 remains in contact with the workpiece w. 12 is called a fixed electrode. The other electrode 12 may be a moving electrode, and one electrode 11 may be a fixed electrode, or both the one electrode 11 and the other electrode 12 may be moving electrodes.

  The heating area of the workpiece w is virtually strip-shaped in accordance with the moving direction of the electrode by moving the moving electrode (one electrode 11 in FIG. 1) from the power supply unit 11 to the electrode pair 13 from the start to the stop of energization. The amount of heat for each of the divided areas can be controlled.

  In the embodiment shown in FIG. 1, the entire area of the workpiece w coincides with the heating area, and the depth width gradually decreases in accordance with the movement direction of the electrodes. Therefore, the amount of heat for each divided region can be controlled by adjusting the moving speed of one electrode 11 while supplying a constant current to the work w from the power supply unit 1 via the electrode pair 13.

  The moving mechanism 15 includes an adjusting unit 15a that controls the moving speed of the electrode to be moved among the one electrode 11 and the other electrode 12, and a driving mechanism 15b that moves the electrode to be moved by the adjusting unit 15a. The adjustment unit 15a obtains the moving speed of the electrode to be moved from the data relating to the shape and dimensions of the workpiece w, and the driving mechanism 15b moves the electrode to be moved at the obtained moving speed. The movement speed obtained by the adjustment unit 15a will be described below.

As shown in FIG. 2, the temperature rise when the current I is passed through the cross-sectional area A ₀ of the unit length for t ₀ (sec) time is obtained from the following equation.
θ ₀ = ρe / (ρ · c) × (I ² × t ₀ ) / A ₀ ² (° C.) (Formula 1)
However, ρe is resistivity (Ω · m), ρ is density (kg / m ³ ), and c is specific heat (J / kg · ° C).
Heating at a current I t _{n (sec)} Time to cross-sectional area A _n of unit length obtained from the following equation.
θ _n = ρe / (ρ · c) × (I ² × t _n ) / A _n ² (° C.) (Formula 2)
Here, the following relational expression is established with the current I being constant and the temperature rise θ ₀ = θ _n .
t ₀ / A ₀ ² = t _n / A _n ² (Formula 3)
Therefore, the time for heating a different cross section to the same temperature by flowing a constant current is proportional to the square of the cross sectional area ratio.
The moving electrode speed ΔV may be set as follows.
ΔV = ΔL / (t ₀ -t _n ) (Formula 4)
However, ΔL is the length of the workpiece in the left-right direction.
Therefore, the moving speed can be obtained from the shape and dimension data of the workpiece w such as a steel material, the amount of current supplied from the power feeding unit 1, and the predetermined heating temperature by the adjusting unit 15a.

  For example, as shown in FIG. 1, when the thickness of the workpiece w is a constant isosceles trapezoid and the depth width changes along the left-right direction, the unit per unit along the left-right direction. The resistance has changed. When such an entire work w is set as a region to be heated, one electrode 11 and the other electrode 12 are arranged across the heating region with a space therebetween, and the power supply unit 1 Either one or both of the one electrode 11 and the other electrode 12 are moved. Then, even if the depth width of the workpiece w changes along the moving direction of the electrode, for example, the speed of moving one electrode 11 is changed according to the change in resistance per unit length, in this case, the change in the depth width. Corresponding to, it is possible to adjust the energization time supplied to each part of the heating region.

  If it is virtually divided into strips in units of depth width along the electrode movement direction of the workpiece w, the energization amount corresponding to the resistance value of the divided area is adjusted by adjusting the energization time as described above. Can be ensured, and the heating region of the workpiece w can be heated in a temperature range of a certain width.

  For example, as shown in FIG. 1, when w has a flat plate shape whose depth width is narrowed in the left direction, based on a change in width in which the electrode to be moved is in contact with the heating region of the workpiece w. , Adjust its moving speed. The moving speed is defined by the function proportional to the square of the change rate of the cross-sectional area from the above equation 4.

  Here, not only when the power supply unit 1 is a DC power source, but also when the average current of the constant period does not change even if it is an AC power source, the energization time is adjusted in the case of a workpiece w having a different cross-sectional area. By doing this, the range of temperature rise due to energization can be made the same range regardless of the part of the heating region of the workpiece w. At that time, any electrode needs to have a dimension that traverses the heating region of the workpiece w. If it does not straddle the region virtually divided into strips, the amount of electricity differs in the depth direction for each region, and thus heating cannot be performed uniformly.

  Thus, according to the electric heating apparatus 10 according to the first embodiment of the present invention, when the depth width of the workpiece w changes in the left-right direction, at least one electrode 11 of one electrode pair 13. The workpiece w can be uniformly heated by moving. As in the past, electrodes are arranged in pairs at opposite ends of the heating area of the workpiece w, and a plurality of electrode pairs are provided, and the supply amount is controlled so that current flows regardless of each electrode pair. There is no need to do it.

  On the other hand, it is also possible to heat by heating so that the heating region of the workpiece w has a temperature distribution. For example, when energization heating is performed so that the depth width is not different in the left-right direction and is substantially constant and has a temperature distribution from high temperature to low temperature in the left-right direction, The electrode 13 may be moved by the moving mechanism 15.

  3 to 6 show a specific structure of the first embodiment shown in FIG. 1, FIG. 3 is a front view, FIG. 4 is a left side view, FIG. 5 is a plan view, and FIG. . As shown in FIGS. 3 to 6, in the energization heating device 20, the electrodes 21 and 22 are configured by electrode portions 21 a and 22 a and auxiliary electrode portions 21 b and 22 b that sandwich the work w from above and below.

  In FIG. 3, the moving electrode 21 is arranged on the left side, and the fixed electrode 22 is arranged on the right side. Each of the moving electrode 21 and the fixed electrode 22 includes a pair of lead portions 21c and 22c, electrode portions 21a and 22a that contact the workpiece w, and auxiliary electrode portions 21b that press the workpiece w toward the electrode portions 21a and 22a. 22b.

  As shown in FIG. 3, as the moving mechanism 25, a guide rail 25a extends in the left-right direction, and a movement control rod 25b formed of a screw shaft extends in the left-right direction above the guide rail 25a, and slides on the guide rail 25a. The movement control rod 25b is screwed to the slider 25c, and the movement of the movement control rod 25b is adjusted by the step motor 25d and rotated, whereby the slider 25c moves to the left and right.

  The moving electrode lead portion 21c is disposed on the slider 25c with the insulating plate 21d interposed therebetween, and the wiring 2a electrically connected to the power feeding portion 1 is fixed to one end portion of the moving electrode lead portion 21c. A moving electrode portion 21a is fixed to the other end portion of the moving electrode lead portion 21c, and a suspension mechanism 26 is disposed to displace the moving auxiliary electrode portion 21b so as to be movable up and down.

  The suspension mechanism 26 is provided on a gantry composed of a stage 26a, wall portions 26b and 26c, a bridge portion 26d, and the like. That is, a pair of wall portions 26b and 26c provided at the other end portion of the stage 26a and spaced apart in the depth direction, a bridge portion 26d extending over the upper ends of the wall portions 26b and 26c, and an axis of the bridge portion 26d The cylinder rod 26e is attached, a clamping portion 26f (which may be called a fixture) attached to the tip of the cylinder rod 26e, and a holding plate 26g that insulates and holds the auxiliary electrode portion 21b. The tip of the cylinder rod 26e is fixed to the upper end of the clamping portion 26f, and a support portion 26i is provided on each of the opposing surfaces of the wall portions 26b and 26c to guide the holding plate 26g in a swingable manner by the connecting shaft 26h. As the cylinder rod 26e moves up and down, the clamping part 26f, the connecting shaft 26h, the holding plate 26c and the auxiliary electrode part 21b move up and down. At this time, since the fixing electrode portion 21a and the auxiliary electrode portion 21b extend so as to cross the heating region of the workpiece w, the upper surface of the fixing electrode portion 21a is swung by the connecting shaft 26h. And the entire lower surface of the auxiliary electrode 21b can be pressed against the workpiece w.

  Even if the suspension mechanism 26 and the lead portion 21c for the moving electrode are moved left and right by the moving mechanism 25, the moving electrode portion 21a and the moving auxiliary electrode portion 21b are held in contact with the flat workpiece w. As described above, in each of the moving electrode portion 21a and the moving auxiliary electrode portion 21b, the rolling rollers 27a and 27b are arranged so as to cross the workpiece w in the depth direction of the workpiece w, and the rolling roller 27a. , 27b can be freely rolled by a pair of bearings 28a, 28b. Even if the moving electrode portion 21a and the moving auxiliary electrode portion 26b are moved left and right by the moving mechanism 25, the state where the work w is energized through the pair of bearings 28a and 28b and the rolling roller 27a is maintained. be able to.

  A fixed electrode 22 is installed on the other side of the electric heating device 20. As shown in FIG. 3, the pulling means 29 for the fixed electrode is disposed on the stage 29a. The fixed electrode lead portion 22c is arranged on the fixed electrode pulling means 29 with an insulating plate 29b interposed therebetween. A wiring 2b electrically connected to the power supply unit 1 is fixed to one end of a fixed electrode lead 22c. The fixed electrode portion 22a is fixed to the other end portion of the fixed electrode lead portion 22c. A suspension mechanism 31 that arranges the auxiliary electrode part 22b for fixation so as to be movable up and down is arranged so as to cover the electrode part 22a for fixation.

  The pulling means 29 for the fixed electrode is connected to the lower surface of the insulating plate 29b to move the stage 29a left and right, sliders 29d and 29e for sliding the insulating plate 26b directly to the left and right, sliders 29d, A guide rail 29f for guiding 29e is provided, and the auxiliary electrode portion 22b, the electrode portion 22a, and the lead portion 22c for the fixed electrode are slid left and right by the moving means 29c to adjust the position. By providing such a pulling means 29 in the energization heating device 20, even if the workpiece w expands due to energization heating, it can be flattened.

  The suspending mechanism 31 includes a pair of wall portions 31b and 31c that are vertically provided at the other end of the stage 31a, a bridge portion 31d that spans the upper ends of the wall portions 31b and 31c, and a bridge portion 31d. A cylinder rod 31e attached on the shaft, a clamping part 31f attached to the tip of the cylinder rod 31e, and a holding plate 31g for insulatingly holding the auxiliary electrode part 22b. The holding plate 31g is clamped by the clamping part 31f via the connecting shaft 31h. The tip of the cylinder rod 31e is fixed to the upper end of the clamping portion 31f, and the holding plate is swingably supported by the support portions provided on the opposing surfaces of the wall portions 31b and 31c, similarly to the suspension mechanism 26. As the cylinder rod 31e moves up and down, the clamping portion 31f, the connecting shaft 31h, the holding plate 31g, and the auxiliary electrode portion 22b move up and down. At this time, since the fixing electrode portion 22a and the auxiliary electrode portion 22b extend so as to cross the heating region of the workpiece w, the upper surface of the fixing electrode portion 22a is swung by the connecting shaft 31h. Each whole surface of the lower surface of the auxiliary electrode portion 22b can be pressed against the work w.

  Although not shown in FIGS. 3 to 6, the workpiece w is supported horizontally by the horizontal support means, the workpiece w is fixed between the fixing electrode 21 and the auxiliary electrode 22, and the moving electrode 21 and the auxiliary electrode 22 are fixed. The moving mechanism 25 moves the moving electrode 21 and the auxiliary electrode 22 with the workpiece w interposed therebetween. The moving electrode 21 is moved by the moving mechanism 25 while the moving speed is controlled by the speed adjusting unit 15b. Therefore, by adjusting the moving speeds of the moving electrode 21 and the auxiliary electrode 22 according to the shape of the work w by the speed adjusting unit 15b, the heating area of the work w can be uniformly heated, or the heating area of the work w can be heated. Can be distributed and heated so as to smoothly change from a high temperature region to a low temperature region.

  Thus, in the electric heating apparatus 20, the electrode part 21a and the auxiliary electrode part 21b are arranged so that the workpiece w is sandwiched between the upper and lower parts. A solid electrode portion 21a having a shape traversing the heating region of the workpiece w is provided across a pair of lead portions 21c (which may be referred to as bus bars) laid along the electrode movement direction. The electrode portion 21a, the auxiliary electrode portion 21b, and the pair of lead portions 21c are attached to means for moving along the electrode moving direction by the drive mechanism 25. At least one of the electrode portion 21a and the auxiliary electrode portion 21b is moved up and down by a cylinder rod 26e as a pressing means, and the workpiece w is sandwiched between the electrode portion 21a and the auxiliary electrode portion 21b while moving on the workpiece w. By traveling, the workpiece w is moved through the bus bar 21c while being energized from the electrode portion 21b.

  3 to 6, at least one of the electrode portion 21 a and the auxiliary electrode portion 21 b is moved up and down by a cylinder rod 26 e as a pressing means, so that the electrode portion 21 a and the auxiliary electrode are moved. The design may be changed so that the electrode part 21a can move while energizing the work w from the electrode part 21b via the bus bar while the work w is sandwiched between the part 21b and traveling on the pair of bus bars.

(Second Embodiment)
FIG. 7: has shown the concept of the electrical heating apparatus which concerns on 2nd Embodiment of this invention, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c). Is a plan view of the state after energization, and (d) is a front view of the state after energization.

  As shown in FIG. 7, the electric heating device 40 according to the second embodiment of the present invention is electrically connected to the power feeding unit 1, and includes an electrode pair 43 including one electrode 41 and the other electrode 42, Moving mechanisms 44 and 45 that move both the electrode 41 and the other electrode 42.

  The moving mechanisms 44 and 45 are not in contact with each other in a state in which one electrode 41 and the other electrode 42 are in contact with the work w and in a state in which the work w is energized from the power supply unit 1 via the electrode pair 43. The one electrode 41 and the other electrode 42 arranged in this manner are moved to widen the distance between the one electrode 41 and the other electrode 42.

  As shown in FIG. 7, when the work w has a rhombus shape in plan view and has a uniform thickness, the depth width is the longest at the center and gradually shortens at both the left and right ends. Become. In order to heat such a workpiece w so as to be in the same temperature range, one electrode 41 and the other electrode 42 are arranged across the workpiece w at a short interval in the center of the workpiece w. One electrode 41 and the other electrode 42 may be moved in the opposite directions at the same speed while a constant current is supplied from the power supply unit 1.

  About the specific apparatus structure of 2nd Embodiment, what is necessary is just to arrange | position the moving electrode arrange | positioned on the left side also on the right side among the structures of 1st Embodiment shown in FIGS.

(Third embodiment)
FIG. 8: has shown the concept of the electric heating apparatus which concerns on 3rd Embodiment of this invention, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c). (D) is a front view in a state of being energized, (e) is a plan view of a state after the energization, and (f) is a front view in a state after being energized.

  In the third embodiment, as shown in FIG. 8, the workpiece w can be virtually divided symmetrically into one isosceles trapezoidal region and the other isosceles trapezoidal region in plan view, In each region, the long side portion of the pair of side portions parallel to each other is arranged outside and the short side portions are continuously arranged. That is, it is like connecting two workpieces w shown in FIG. 1 of the first embodiment. In that case, the present invention can be applied by improving the electric heating apparatus 10 according to the first embodiment as follows.

  In the energization heating device 50 according to the third embodiment of the present invention, an energization unit 50a including an electrode pair 53a and a moving mechanism 56a and an energization unit 50b including an electrode pair 53b and a moving mechanism 56b are arranged on the left and right, respectively. The electrode pair 53a arranged on the left side in plan view of the workpiece w is composed of one electrode 51a and the other electrode 52a.

  In the left energizing unit 50a, one electrode 51a is disposed at the left end portion of the workpiece w as a fixed electrode, and the other electrode 52a as a moving electrode is slightly spaced to the right of the one electrode 51a in plan view. They are opened and moved by the moving mechanism 56a.

  In the right energizing unit 50b, one electrode 51b is arranged as a fixed electrode at the right end of the workpiece w in plan view, and the other electrode 52b as a moving electrode is slightly spaced on the left side of one electrode 51b in plan view. They are opened and moved by the moving mechanism 55b.

  Similar to the first and second embodiments, each of the moving mechanisms 55a and 55b includes adjusting units 54a and 54b that control the moving speed of the moving electrode, and drive mechanisms 55a and 55b that move the moving electrode using the adjusting units 54a and 54b. 55b. The adjusting units 54a and 54b obtain the moving speed of the moving electrode from the data relating to the shape and dimensions of the workpiece w, and the driving mechanisms 55a and 55b move the moving electrode at the obtained moving speed.

  8C and 8D in a state where the electrodes are arranged as shown in FIGS. 8A and 8B and the work w is supplied by the power supply unit 1 via the electrode pairs 53a and 53b. ), The other electrodes 52a and 52b are moved by the moving mechanisms 56a and 56b, respectively, and are moved away from the one electrodes 51a and 51b, respectively. Thereafter, as shown in FIGS. 8E and 8F, the other electrodes 52a and 52b are moved in the vertical direction so as to be in non-contact with the workpiece w. At that time, energization from the power supply unit 1 to each of the electrode pairs 53a and 53b is stopped, a circuit is switched using a switch (not shown), and energization is resumed from the power supply unit 1 between the electrode 51a and the electrode 51b. Thereby, the site | part between the other electrode 52a and the other electrode 52b among the workpiece | work w can be energized and heated.

  Also in the third embodiment, the moving mechanism 56a, 56b moves the other electrode 52a, 52b as the moving electrode while controlling the moving speed based on the shape and size of the workpiece w, so that the electrode pair 53a moves one of the electrodes. By energizing between the electrode 51a and the other electrode 52a, and energizing between the one electrode 51b and the other electrode 52b by the electrode pair 53b, the amount of heat for each part of the workpiece w is made equal and uniform heating can do.

  In addition, about each structure of electricity supply unit 50a, 50b, the structure similar to 1st Embodiment is applicable, and what is shown to FIGS. 3-6 is mentioned as a specific structure.

(Fourth embodiment)
FIG. 9 shows the concept of the electric heating device according to the fourth embodiment of the present invention, where (a) is a plan view of the state before energization, (b) is a front view of the state before energization, and (c). Is a plan view of the state after energization, and (d) is a front view of the state after energization.

  The configuration of the electric heating device 10 shown in FIG. 9 is the same as that of the electric heating device 10 shown in FIG. That is, the electric heating apparatus 10 according to the fourth embodiment of the present invention is electrically connected to the power feeding unit 1 and includes an electrode pair 13 including one electrode 11 and the other electrode 12, one electrode 11, and the other electrode. A moving mechanism 15 that moves one or both of the electrodes 12. The moving mechanism 15 moves one electrode 11 while the one electrode 11 and the other electrode 12 are in contact with the work w and the work w is energized from the power supply unit 1 via the electrode pair 13. Thus, the distance between one electrode 11 and the other electrode 12 is changed.

  The fourth embodiment differs from the first embodiment in the shape of the workpiece w. In other words, the depth width of the work w does not change along the left-right direction in plan view, and the thickness decreases in one direction. This reduces the cross-sectional area in one direction.

  Also in the fourth embodiment, the heating area of the workpiece w is moved by moving the moving electrode (one electrode 11 in FIG. 9) from the start of energization to the electrode pair 13 by the power feeding unit 11 until it stops. The amount of heat for each region virtually divided into strips according to the direction can be controlled.

For example, as shown in FIG. 9 , even when the thickness of the workpiece w is reduced in the left direction, the moving speed is defined by a function proportional to the square of the change rate of the cross-sectional area from the above equation 4.

(Fifth embodiment)
FIG. 10: has shown the concept of the electric heating apparatus which concerns on 5th Embodiment of this invention, (a) is a top view of the state before electricity supply, (b) is a front view of the state before electricity supply, (c). Is a plan view of the state after energization, and (d) is a front view of the state after energization.

  The electric heating apparatus 10 shown in FIG. 10 has the same configuration as the electric heating apparatus 10 shown in FIG. In the workpiece w, the heating area is not the entire workpiece w but one of the left and right areas. That is, the entire area of the workpiece w is divided into two areas, a heating area w1 and a non-heating area w2. This is because the material of the heating region w1 and the material of the non-heating region w2 are different, and they are integrated by welding. As an example of use of such a workpiece w, there is a member that absorbs an impact by increasing the hardness of the heating region w1 and making the non-heating region w2 easily deformed by impact or the like. In this case, one electrode 11 and the other electrode 12 are disposed on the side of the heating region w1 that has a large cross-sectional area along the direction orthogonal to one direction, and the cross-sectional area moves in a direction that decreases. The moving speed may be set based on Equation 4. Thereby, also in 5th Embodiment, the heating area | region w1 of the workpiece | work w is moved by moving a moving electrode (one electrode 11 in FIG. 10) by the electric power feeding part 11 to the electrode pair 13 before it stops, It is possible to control the amount of heat for each region virtually divided into strips according to the moving direction of the electrodes.

(Sixth embodiment)
FIG. 11: has shown the concept of the electrically heating apparatus which concerns on 6th Embodiment of this invention, (a) is a top view before the electricity supply, (b) is a front view of the state before electricity supply, (c). Is a plan view of the state after energization, and (d) is a front view of the state after energization.

  The electric heating device 40 shown in FIG. 11 has the same configuration as the electric heating device 40 shown in FIG. The difference is that one of the left and right sides of the workpiece w is a region w1 that is heated almost uniformly to the hot working temperature, and the other is a region w2 that is heated uniformly to a warm working temperature lower than the quenching temperature. The entire area of the work w is composed of areas w1 and w2 that are heated to different temperatures. As in the fifth embodiment, the workpiece w is different from the material in the region w1 and the material in the region w2 and is integrated by connecting them by welding. In this case, the moving electrodes 41 and 42 are moved by the moving mechanisms 44 and 45, respectively. The left region w1 is uniformly heated to the hot working temperature, whereas the right region w2 is heated to the warm working temperature, and is easily pressed in a subsequent process. For this reason, the moving mechanism 44 moves the moving electrode 41 so as to satisfy the relationship of Formula 4 while flowing a constant current between the moving electrodes 41 and 42, thereby heating the region w1 to a uniform hot working temperature, and the region w2 Is moved to a predetermined warm heating temperature, the moving mechanism 45 moves the moving electrode 42. At this time, the movement start time and movement end time of each of the moving electrodes 41 and 42 may be appropriately set according to the horizontal dimension, hot working temperature, and warm working temperature of each region w1, w2.

While a plurality of embodiments have been described above, the present invention can be implemented with appropriate modifications according to the shape and dimensions of the workpiece w. Workpiece w is not limited to the shape shown, the workpiece w is if it contains a region in which resistance increases per unit by, for example, the cross-sectional area along the one direction becomes smaller length, moving the electrode in that direction Thus, the region can be heated uniformly. Note that the workpiece w may be curved without being a straight line connecting the left and right ends of the outer periphery, or may be configured by connecting a plurality of straight lines or curves with different curvatures. Good.

  In the above description, the case where the entire workpiece w is a heating region, a part of the workpiece w is a heating region, the workpiece w is divided into a plurality of regions, and each region is a heating region. However, other than that, in the direction intersecting the moving direction of one of the moving electrodes of one and the other of the electrodes arranged at an interval with respect to the work w, that is, the horizontal direction of the work w Instead, the heating area is divided in the depth direction, and a moving electrode may be arranged for each heating area. In that case, the heating region may be divided adjacent to the depth direction, or may be set separately in the depth direction.

  As described above, it is also included in the scope of the present invention to appropriately change the design so that the work w is energized and heated by providing one or a plurality of electrodes to be moved according to the shape and size of the work w and the heating region of the work w. It is. In that case, you may use a fixed electrode as needed.

1: Power supply unit 2a, 2b: Wiring 5L, 5R: Electrodes 10, 20, 40, 50: Current heating device 11: One electrode (moving electrode)
12: The other electrode (fixed electrode)
13: Electrode pair 15: Moving mechanism 15a: Adjustment unit 15b: Drive mechanism 21: Electrode (moving electrode)
22: Electrode (fixed electrode)
21a, 22a: electrode part 21b, 22b: auxiliary electrode part 21c, 22c: lead part 21d: insulating plate 25: moving mechanism 25a: guide rail 25b: movement control rod 25c: slider 25d: step motor 26, 31: suspension mechanism 26a, 31a: stages 26b, 26c, 31b, 31c: wall portions 26d, 31d: bridge portions 26e, 31e: cylinder rods 26f, 31f: clamping portions 26g, 31g: holding plates 26h, 31h: connecting shafts 26i: support portions 27a 27b: Rolling rollers 28a, 28b: Bearing 29: Pulling means 29a: Stage 29b: Insulating plate 29c: Moving means 29d, 29e: Slider 29f: Guide rail 41: One electrode (moving electrode)
42: The other electrode (moving electrode)
43: Electrode pair 44, 45: Movement mechanism 44a, 45a: Adjustment unit 44b, 45b: Drive mechanism 50a, 50b: Energizing unit 51a, 51b: One electrode (fixed electrode)
52a, 52b: other electrode (moving electrode)
53a, 53b: Electrode pairs 54a, 54b: Drive mechanisms 55a, 55b: Adjustment units 56a, 56b: Movement mechanisms

Claims (7)

An electrode pair that is electrically connected to the power supply unit and includes one electrode and the other electrode;
In a state where via pre Symbol electrode pairs before SL one electrode and the other electrode from a state at and before Symbol feeding portion in contact with the workpiece is energized in the work, before Symbol One electrode, prior SL other electrode a moving mechanism for changing the distance between the front SL one electrode before SL other electrode move either one or both of,
Equipped with a,
The moving mechanism, Ru includes an adjusting unit that controls the moving speed of the electrode to be moved out of the one electrode and the other electrode, and a driving mechanism for moving the electrode to be the movement by the adjustment unit, the energization Heating device.   The energization heating apparatus according to claim 1, wherein the one electrode and the other electrode have a length traversing a region to be heated of the workpiece. The energization heating apparatus according to claim 1 , wherein the adjustment unit obtains a moving speed of the electrode to be moved from data relating to a shape and dimensions of a workpiece, and the driving mechanism moves the electrode to be moved at the obtained moving speed. .   The one electrode and the other electrode both include an electrode part and an auxiliary electrode part sandwiching a workpiece from above and below, and a lead part to which a wiring from the power feeding part is connected and energizes the electrode part. Item 4. The electric heating apparatus according to Item 1.   The energization heating apparatus according to claim 1, wherein one of the one electrode and the other electrode is a moving electrode that is moved by the moving mechanism.   The electric heating apparatus according to claim 1, wherein both the one electrode and the other electrode are moving electrodes that are moved by the moving mechanism. The energization heating apparatus according to claim 5 or 6 , wherein the moving electrode has means for rolling or sliding while contacting a region to be heated of the workpiece.

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