JPH0818062B2 - Electric heating device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heating apparatus, and more particularly to an electric heating apparatus including a cooling means for cooling an electrode portion and an end portion of a member to be heated which is in pressure contact with the electrode portion. .

(Prior Art) When heating a steel material for processing, there is an electric heating method in which an electric current is directly applied to the steel material for heating. In this energization heating method, electrode parts are pressed against both ends of the steel material, and the steel material is energized through both of these electrode parts, and the steel material is directly heated by its Joule heat. This energization heating is rapid heating, the high temperature region time is short, and it is also advantageous for scale generation and surface quality. In addition, the electric heating is advantageous in terms of cost because it directly heats the steel material as a resistor and is advantageous in terms of cost. In addition, since the temperature control is on-off control, the responsiveness is also excellent. In addition, the electric heating can heat the entire length of the steel material at the same time, so no heat-retaining zone is required, which is advantageous in terms of equipment and space. It is widely used in place of other induction heating methods, combustion heating methods, etc. Is being done.

(Problems to be Solved by the Invention) However, in the above-mentioned electric heating, in general, since both ends of the steel material are pressed into contact with each other, these electrode portions and both end portions of the steel material where the electrode portions are pressure-contacted are in contact with each other. There is a problem that the resistance easily causes overheating, and as a result, the temperature of the steel material is locally different and the heating becomes uneven.

The present invention has been made to solve the above-described problems, and prevents the overheating and uniformly heats the heated member by cooling the electrode portion and the end of the heated member that is pressed against the electrode portion. It is an object of the present invention to provide an electric heating device as described above.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, in an electric heating device for heating by heating the member to be heated by pressing the electrode portions to both ends of the member to be heated, Nozzles are arranged in the vicinity of the respective electrode parts at the respective electrode parts and the respective end parts of the member to be pressure-contacted with the respective electrode parts so that the nozzles face the respective nozzle parts, and the respective electrode members are heated at the time of electric heating. And a structure in which a mist-like cooling medium is sprayed onto each end of the heated member to cool it.

(Operation) A mist-like cooling medium is jetted from the nozzle of each nozzle to both ends of the electrode to be pressed against the electrode and the electrode of the heated member when the heated member is electrically heated. The mist-like cooling medium is a mixture of water and air, and supercooling is prevented as compared with cooling with only water, and cracks and scratches are prevented from occurring during rolling.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of an electric heating apparatus according to the present invention. The electric heating apparatus 1 mounts a steel material to be rolled, for example, a stainless steel round bar 300 (hereinafter referred to as steel material 300) and mounts it on an insertion line mechanism. Material charging device 2 to be charged, heating device 3 for electrically heating the steel material, steel material to be heated from the material charging device 2 is carried into the heating device 3, and after completion of heating, it is taken out and carried out to the carrying device 5 Device 4, transfer device 5 for transferring the heated steel material taken out from heating device 3 to the rolling device, power supply device 6 for supplying required power to heating device 3, and control for controlling each of these devices at predetermined timing It is configured by the device 7 and the like.

The material charging device 2 is composed of a mounting table 20 on which the steel material 300 is mounted, a charging mechanism 21, an insertion line mechanism 22 and the like, and the charging device 21 sets the steel material 300 mounted on the mounting table 20 to 1 This is a well-known technique for sequentially supplying each line to the insertion line mechanism 22.

The insertion line mechanism 22 is arranged on one side of the mounting table 20 and temporarily holds the steel material to be supplied to the heating device 3. The insertion line mechanism 22 is composed of a roller conveyor, and a stopper 22a for positioning the material is fixed at one end thereof. , The rollers 22b are individually rotated by motors (not shown),
The steel material placed on top is transferred in the direction of the stopper 22a along the insertion line LNa, and the tip surface of the steel material is moved to the stopper 2a.
Position it by locking it to 2a. This insertion line mechanism 22
A detection device 8 for detecting the length of the steel material is disposed along the insertion line mechanism 22 as shown in FIG. 11 described later.

The detection device 8 is composed of a plurality of, for example, 6 sets of photoelectric detectors 80 to 85 arranged at a predetermined interval from the other end of the insertion line mechanism 22 toward the center, and includes a light emitting element 80a of the photoelectric detector 80. The light receiving element 80b is arranged to face each other on both sides of the insertion line LNa, and detects the presence or absence of the rear end of the steel material arranged on each roller 22b of the insertion line mechanism 22, that is, the length of the steel material. Each of the other steel detectors 81 to 85 has the same structure as the photoelectric detector 80. Each of these detectors 80 to 85 is connected to the control device 7.

The heating device 3 is for electrically heating the steel material,
A pair of rails 30, 30 arranged along one side of the insertion line mechanism 22 and laid on the floor surface, and the rails 30, 30.
A bus bar 31 for power supply that is laid parallel to the outside of the rail 30, a fixed carriage 32 that is fixedly arranged on one end side of the rail 30 and has a heating electrode portion arranged on the upper portion, and a fixed carriage 32 on the rail 30. It is composed of a movable carriage 33 and the like, which are placed so as to be opposed to each other and are provided with a heating electrode portion on the upper portion thereof.

A plurality of charging / extracting devices 4 are provided, for example, five charging / extracting devices 40 to 44.
And a holder mechanism 45 (FIG. 11), each of the charging / extracting machines 40 to 44 is configured as shown in FIG.
The rails 30 and the bus bars 31 of the heating device 3 are arranged orthogonally to each other at a predetermined interval.

The conveying device 5 is arranged along the heating device 3 on the opposite side of the insertion line mechanism 22 and is composed of a roller conveyor, and each roller 5a is driven by a motor (not shown) and placed on each of these rollers 5a. Is transported in the direction of arrow A on the transport line LNb. A rolling device (not shown) is arranged on the extension of the transfer line LNb in the direction of arrow A.

The power supply bus bar 31 includes a pair of fixed bus bars 31A and 31A and a pair of moving bus bars 31 as shown in FIGS.
B, 31B and each of these fixed bus bars 31
A, 31A, the moving bus bar 31B, 31B is formed of a steel rectangular rod-shaped body, respectively, to a plurality of support rollers 34 arranged on the outer surface of each rail 30, 30 at a predetermined interval along the longitudinal direction thereof. It is electrically insulated and supported. Each fixed bus bar 31
A and 31A are fixed, one ends 31a and 31a (Fig. 2) are located at substantially the center positions of these rails 30 and 30, and the other ends 31a 'and 3a are located.
1a 'projects toward the power supply device 6 side from the other end of each rail 30, 30.

The movable bus bars 31B, 31B are parallel to the outer sides of the fixed bus bars 31A, 31A, respectively, with a slight gap, and are movably arranged on each roller 34 along the longitudinal direction of the fixed bus bars 31A, 31A, and the other ends thereof. 31b 'and 31b' are fixed to both sides of the moving carriage 33 as described later and are connected to respective electrode portions mounted on the moving carriage 33, and slide with the movement of the moving carriage 33 to move the moving carriage 33. The length of the connecting conductor between the power supply device 6 and the power supply device 6 is minimized to reduce the conductor loss. Further, the other ends 31b, 31b of the respective moving bus bars 31B, 31B are located at substantially central positions of the respective rails 30, 30 in a state where the moving carriage 33 is retracted to the maximum retracted position shown by a two-dot chain line. One end 31a, 31a of each fixed bus bar 31A, 31A and the clamp mechanism
It is possible to abut from 35, 35.

Clamping mechanism 35, 35 is one end of fixed bus bar 31A, 31A
The movable bus bars 31B, 3 are provided at the outer positions of 31a, 31a.
1B is pressed from the outside to press the fixed bus bars 31A, 31A into contact with the opposing one ends 31a, 31a of the fixed bus bars 31A to electrically connect them.The hydraulic cylinder 35a and the rod 35b of the hydraulic cylinder 35a. And a pressing pad 35c attached to the tip of the. When the hydraulic cylinder 35a expands, it moves via the pad 35c and fixes the bus bar 31B.
When one end 31a is pressed and shortened, the pressing force is released to bring them into sliding contact with each other, so that the moving bus bar 31B can be moved. Each of these clamp mechanisms 35, each hydraulic cylinder 35 of 35
Solenoid valves (not shown) for driving a and 35a are controlled by the controller 7.

The other ends 31a ', 31a' of the fixed bus bars 31A, 31A are connected to the positive electrode terminal 6a (first terminal) of the power supply device 6 via connecting members 31c, 31c, respectively.
Figure) connected. The negative electrode terminals 6b and 6b of the power supply device 6 are connected to the below-mentioned electrode portion mounted on the fixed carriage 32 through the connecting members 36 and 36.

The fixed carriage 32 is configured as shown in FIGS. 4 and 5, and the base 100 of the fixed carriage 32 is the rail 3 as described above.
The rail 30 is fixed to one end of the rail 30 and is mounted on the base 100.
A pair of rails 101, 101 are laid parallel to the rails 101, and a pedestal 103 is slidably mounted on the rails 101, 101 via a pair of guides 102, 102. An air cylinder 104 is arranged between the base 100 and the pedestal 103 along the sliding direction of the pedestal 103, the bottom end of the cylinder portion 104a is fixed to the upper rear portion of the base 100, and the rod 104b is fixed. The tip is fixed to the front part of the bottom surface of the pedestal 103 via a connecting member. The gantry 103 can be advanced in the direction indicated by the arrow B by the maximum stroke L ₁ by the extension of the air cylinder 104. This stroke L ₁ is for retracting the fixed carriage 32 when the steel material is carried in and out of the heating device 3.

Three support members 105 to 107 are arranged on the frame 103,
The supporting member 105 is arranged at the rear end of the gantry 103, and the supporting members 106 and 107 are arranged at both sides of the front end so as to face each other at a distance. Support member
The hole 105a is formed in the center at a position corresponding to the axial center position LNc of the heating device 3, the air cylinder 110 is arranged on the rear end surface of the support member 105, and the rod 105b of the air cylinder 110 is An electrode supporting member 115 is attached to the tip by loosely fitting the hole 105a and projecting forward.

An intermediate position between the two supporting members 106 and 107 of the gantry 103, and an upper portion of the supporting members 106 and 107 with the axis LNc as the center thereof.
Holes 103a, 106a, 107a that are opened in the radial direction of Nc are provided. And, each of these holes 103a, 106a, 107a is an axial core.
They are arranged at equal intervals in the circumferential direction on the circumference centered on LNc. A hydraulic cylinder 111 is provided at the position of the hole 103a on the bottom surface of the gantry 103, and the rod 111a loosely fits the hole 103a and projects upward, and the electrode support member 116 is attached to the tip. The hydraulic cylinder 112 is also provided outside the hole 106a of the support member 106.
The rod 112a is loosely fitted into the hole 106a and protrudes inward, and the electrode support member 117 is attached to the tip thereof. Similarly to the support member 106, a hydraulic cylinder 113 is attached to the support member 107, and an electrode support member 118 is attached to the tip of the rod of the hydraulic cylinder 113.

Each electrode support member 115-118 is electrically connected and fixed to the support member 105 via flexible conductors 120-123. A connection terminal 125 is electrically connected and fixed to the support member 105, and both ends of the connection terminal 125 are connected to the connection members 36 and 36 shown in FIG. 2 via flexible conductors 126 and 126. .

As shown in FIG. 5, an electrode member 130 is attached to the position of the axis LNc of the electrode supporting member 115, and the electrode supporting members 116 to 118 are mounted.
Electrode members 131 to 133 are also attached to the axial center positions of the electrodes as shown in FIG. The electrode member 115 can be moved forward and backward according to the expansion and contraction of the air cylinder 110. When the air cylinder 110 is extended, it is advanced in the direction of arrow B as shown in FIG. Is retracted until it touches. The electrode members 131-133 are hydraulic cylinders 111-1.
It can move in the radial direction of a circle centered on the axis LNc according to the expansion and contraction of 13. When the cylinders 111 to 113 are extended, the tip surfaces of the electrode members 131 to 133 are gathered on the axis Lc, and when the cylinders are shortened, the electrode support members 116 to 118 are mounted on the mount 103 and the support member 1 respectively.
Move it back until it touches 06, 107. Each of these hydraulic cylinders 110 to 113 is controlled by the control device 7.

The electrode member 130 mounted on the electrode support member 115 has a substantially conical shape and has a tip 130a as shown in FIGS.
Is formed into a substantially hemispherical shape. The tip 130a of the electrode member 130 is brought into contact with the end surface of the steel material 300 as shown in FIG. In addition, the electrode member 1 attached to the electrode support member 116
As shown in FIG. 6, reference numeral 31 denotes a substantially cylindrical body, the tip of which is cut out from both sides at a predetermined angle in a substantially wedge shape to form an inclined surface 131a,
131a is formed, and further, the end surface 131b is cut out leaving a predetermined length d in the diameter direction to form an inclined surface 131c. The width of the tip surface 131a is w as shown in FIG. 7C, and the end surface 131a is made of steel 300 as shown in FIG.
It is possible to make line contact with the side surface of one end 300a. Other electrode members
132 and 133 are also formed similarly to the electrode member 131. Therefore, regardless of the outer diameter of the steel material 300, the three electrode members 131 to 133 are capable of abutting the respective end surfaces on the end surface of the steel material along the longitudinal direction and at equal intervals in the circumferential direction.

These electrode members 131 to 133 have an end face 131b (only one of which is shown) having a suitable length depending on the steel material to be heated, for example, d ₁ , d ₂ (d ₁ > d, d ₂ > d). It can be used by exchanging it with another one. In this way, by changing the contact length d of the electrode members 131 to 133 to the steel material, the contact resistance is dispersed,
It is possible to prevent overheating of the contact portion.

As shown in FIG. 4, a nozzle 135 for cooling is arranged on the upper part of the electrode support member 117, and its nozzle (tip) 135 is provided.
a is disposed diagonally above the electrode member 132 so as to face one end of the shaft core LNc, that is, one end 300a (FIG. 7) of the steel material 300, and the other end 135
b is connected to the cooling system via a hose 136. For example, air is used as the cooling medium, and the hose 136 is connected to an air source (both not shown) via a solenoid valve. This solenoid valve is controlled by the control device 7. Since the end portion 300a of the steel material 300, which is pressed against the electrode members 131 to 133 during electric heating, is locally overheated compared to other portions, the steel material 300 is cooled by blowing air to the end portion 300a. It is installed to keep the temperature of 300 as a whole. Such nozzle 135
The number may be one as shown, or may be provided for each electrode supporting member.

The cooling medium is not limited to the air,
Others, for example, using water to mist the water and steel materials
You may make it cool by spraying on the overheated part of the edge part 300a of 300.

The movable carriage 33 is configured as shown in FIGS. 8 and 9, and is movable on the rails 30 and 30 via two sets of rollers 151 and 152 mounted on the front and rear of the bottom of the base 150. A motor 153 that is placed and housed in the base 150 can move back and forth. On the base 150, a pair of rails 154, 154 are laid in parallel with the rail 30. These rails 15
A pedestal 156 is slidably mounted on the tops 4 and 154 via two pairs of guides 155 and 155 fixed to the front and rear ends of the bottom surface, respectively.

A rail 154 is provided between the base 150 and the mount 156 and in the center position.
An air cylinder 157 is arranged along the
The bottom end of the cylinder part is fixed to the rear end of the upper surface of the base 150, and the tip of the rod is fixed to the front end of the bottom surface of the pedestal 156. When the cylinder 157 is extended, the pedestal 156 can be moved to a front end position as shown by a solid line in FIG. 9 and to a rear end position as shown by a chain double-dashed line by a maximum stroke L ₂ when shortened. The cylinder 156 is set free when energized to allow the movable carriage 33 to move freely, and absorbs a change in length due to thermal expansion of the steel material caused by the energization. Support members 160 to 162 are arranged on the pedestal 156 similarly to the fixed carriage 32, and the electrode support members 170 to 162 are provided on the support members 160 to 162 via air cylinders 165 and hydraulic cylinders 166 and 167, respectively. 172 is mounted, and an electrode support member 173 is arranged on the gantry 156 at an intermediate position between the support members 161 and 162 via a hydraulic cylinder 168.

Electrode members 175 to 178 are mounted on the electrode supporting members 170 to 173, and these electrode members 175 to 178 are formed similarly to the electrode members 130 to 133 (FIG. 4) of the fixed carriage 32. . Then, each electrode member 130 of the fixed carriage 32 and the movable carriage 33.
And 175 are located on the axis LNc and face each other. A nozzle 210 (Fig. 8) is arranged above the electrode supporting member 171, and its nozzle is arranged diagonally above the electrode member 175 so as to face the axis LNc, as in the nozzle 135 shown in Fig. 4. The rear end is connected to the air source via a hose 211 and a solenoid valve (not shown). This solenoid valve is also controlled by the control device 7.

The other ends 31b ', 31b' of the moving busbars 31B, 31B are the second,
As shown in FIGS. 3 and 8 and 9, insulating members are fixed to both sides of the base 150 via connecting members 180, 180, and upper ends of the connecting members 180, 180 are flexible conductors 181, 181. And electrically connected and fixed to the support member 160 via the connection members 182 and 183. Each of the electrode supporting members 170 to 173 is electrically connected to and fixed to the supporting member 160 via a flexible conductor.

The two support members 1 arranged on both sides of the front end of the frame 156.
Supporting members 190 and 190 (Fig. 11) are fixedly provided on the supporting members 190 and 190, respectively, so as to sandwich the axis LNc between them 61 and 162 and project toward the front of the mount 156. Detectors 86, 87 for detecting the rear end position are arranged at predetermined intervals along the direction of the shaft core LNc. These detectors 86 and 87 are light emitting elements 86a and 87a which are arranged on both sides of the axial core LNc so as to be spaced apart and face each other.
The presence or absence of the rear end portion of the steel material 300 which is configured by the light receiving elements 86b and 87b and is arranged at the shaft core LNc position is detected. Each of these detectors 86, 87 is connected to the control device 7, respectively.

On both sides and the front end of the base 150, the heated steel material 300 is cooperated with the charging and extracting device 4 as shown in FIG.
An extraction mechanism 200 for extracting the transport device 5 is provided. The extraction mechanism 200 includes support members 201, 201 fixed at their lower ends to both sides of the front end of the base 150, and support for each of these. Members 202, guides 202 horizontally bridged to each upper end of each member 201, an air cylinder 205 horizontally arranged at one end of the guide 202, and fixed to the tip of a rod 205a of the cylinder 205, Further, a support member 206 slidably supported by the guide 202 in the horizontal direction, an air cylinder 207 arranged vertically to the support member 206, and a tip of a rod 207a of the air cylinder 207 are arranged. It is composed of a clamp mechanism 208 and the like.

The air cylinder 205 includes a support member 206 fixed to the tip of the rod 205a and a shaft core LN of the heating device 3 indicated by a two-dot chain line 206 '.
Guide from the position of c to the position of the transport line LNb shown by the solid line
It can slide horizontally along 202. The clamp mechanism 208 is composed of a pair of arms 208a, 208a which are rotatably supported at their central portions by a supporting member 206a slidably mounted on the supporting member 206 and whose lower ends can be opened and closed. Each arm 208a, the upper end of each 208a is respectively connected to the rod 207a of the air cylinder 207, and when the cylinder 207 is extended, the carrier line LNb and the axis LNc are moved downward and closed,
When shortened, it is moved up and opened. As a result, the end of the steel material 300 heated by the heating device 3 can be sandwiched, extracted from the heating device 3 and placed on the conveying device 5, so that the end portion of the steel material hangs down due to its own weight. To prevent.

An air cylinder 157 that drives a frame 156 of the moving carriage 32, an air cylinder 165 that drives the electrode members 170 to 173, hydraulic cylinders 166 to 168, and air cylinders 205 and 20 of the extraction mechanism 200.
7 are connected to an air source via respective solenoid valves, and these respective solenoid valves are connected to the control device 7.

As shown in FIG. 10, the air cylinder 157 for driving the gantry 156 has solenoid valves 210, 211 and solenoid valves 210, 211 and 157c, respectively, as shown in FIG.
The solenoid valve 212 is connected to the air source through the solenoid valve 212.
Either one of 210 or 211 is selectively connected to the air source, and the solenoid valves 210 and 211 have respective ports 157b and 157c connected to the solenoid valve.
Connect to 212 or open to atmosphere. Each of these solenoid valves 210
˜212 are connected to the control device 7.

As shown in FIGS. 11 and 12, the charging / extracting device 40 of the charging / extracting device 4 (FIG. 1) has its front end orthogonal to the positions above the rails 30 and 30 and immediately below the transfer line LNb. A pair of rails 220, laid movably, and a carriage 221 movably mounted on the rail 220, and a rod 222a disposed between the rail 220 and the carriage 221 and along the moving direction of the carriage 221. Is fixed to one end of the rail 220, and the cylinder part 222b
An air cylinder 222 whose bottom end is fixed to approximately the center of the bottom of the truck 221 and a truck 223 movably mounted on the truck 221.
Between the carriages 221 and 223 and along the moving direction of the carriage 223, and the tip of the rod 224a is mounted on the carriage 22.
An air cylinder 224 fixed to approximately the center of the bottom of 3 and a bottom end of a cylinder portion 224b fixed to one end of a truck 221, and a truck 22
3 and two holder mechanisms 225 and 230 which are arranged at a predetermined interval at the substantially central position.

The air cylinders 222 and 224 are respectively trolleys 221 and 223 when extended.
In the direction of arrow D to the position shown by the solid line in FIG.
At the time of shortening, they are retracted in the direction of arrow E to the positions indicated by the chain double-dashed lines. The holder mechanism 225 is composed of an air cylinder 226 arranged vertically to the carriage 223 and a holder 227 fixed to the tip of the rod of the air cylinder 226. When the air cylinder 226 is shortened, the holder 227 is shown in FIG. As indicated by the solid line, the charging line LNa and the axis LNc of the heating device 3 are lowered to a position slightly lower than that of the charging line LNc and the axis LNc, as shown by the two-dot chain line. Raise it to a higher position. The holder mechanism 230 is also configured similarly to 225.

Air cylinders 222, 224 for driving the trucks 221, 223
And each air cylinder 226, 2 of each holder mechanism 225, 230
A solenoid valve (not shown) for driving 31 is controlled by the controller 7 (shown by a chain double-dashed line in FIG. 11). Other charging extraction machine
41 and 42 are also configured similarly to the charging and extracting machine 40.

As shown in FIGS. 11 and 13, the charging / extracting device 43 of the charging / extracting device 4 (FIG. 1) is laid at the front end above each rail 30, 30 and at a position right below the unloading line LNb at a right angle. Base 2
A dolly 241 movably mounted on 40 and these bases 2
It is arranged between 40 and the truck 241 and along the moving direction of the truck 241, the tip of the rod 242a is fixed to one end of the base 240, and the bottom end of the cylinder portion 242b is substantially the center of the bottom of the truck 241. Fixed to the air cylinder 242, and two holder mechanisms 24 arranged at a predetermined distance from the tip end of the carriage 241 at a substantially central position.
It is composed of 5, 250.

The air cylinder 242 advances the carriage 241 in the direction of arrow D to the position indicated by the chain double-dashed line in FIG. 13 when extended, and retracts it in the direction of arrow E to the position indicated by the solid line when shortened. The holder mechanism 245 is an air cylinder 246 arranged vertically on the carriage 241.
And a holder 247 fixed to the tip of the rod of the air cylinder 246. When the air cylinder 246 is shortened, the holder 247 is heated by the heating device 3 as shown by the solid line in FIG.
Lower to a position slightly lower than the shaft core LNc of
As shown by the dotted line, the position is raised to a position slightly higher than the position of the shaft core LNc. The holder mechanism 250 is also configured similarly to 245.

An air cylinder 242 that drives the carriage 241 and a solenoid valve (not shown) that drives the air cylinders 246 and 251 of the holders 245 and 250 are controlled by the controller 7 (shown by a chain double-dashed line in FIG. 11). Controlled. The other charging / extracting machine 44 has the same structure as the charging / extracting machine 43.

The charging / extracting device 4 is further provided with a holder mechanism 45 as shown in FIGS. 11 and 14, and the holder mechanism 45 is located at the center position of the rails 30, 30 of the heating device 3 along the longitudinal direction of the rail 30. A plurality of, for example, 6 are arranged at predetermined intervals. The holder mechanism 45 includes an air cylinder 260 vertically disposed between the rails 30, a table 261 fixed to the tip of the rod of the air cylinder 260, and an axis LNc of the heating device 3 on the table 261. The roller 262 is rotatably supported along the direction. When the air cylinder 260 is extended, the upper surface of the roller 262 is aligned with the axis LNc as shown by the solid line in FIG. 14, and when it is shortened, the second holder mechanism 45 from the left in FIG.
The roller 262 is lowered from the axis LNc by a height H as shown in FIG. The drive of the air cylinder 260 is controlled by the controller 7. Each of the other holder mechanisms 45 has the same structure.

Further, as shown by the chain double-dashed line in FIG. 11, a temperature sensor 88 is arranged near the fixed carriage 32. This temperature sensor 88 has its detection portion as shown in the drawing, which is the axis LN of the heating device 3.
The tip 300a of the steel material 300 that is placed facing one end of c and is heated
The temperature is detected and the corresponding temperature signal is output to the controller 7. The temperature sensor 88 is, for example, an infrared temperature sensor.

The power supply device 6 is for supplying a predetermined direct current to the electrode members 175 to 178 of the movable carriage 33 of the heating device 3,
It is equipped with a high-voltage power supply panel, a transformer, a rectifier, a cooling device for cooling the rectifier, and a control panel (none of which is shown). It receives a three-phase alternating current, rectifies it, and outputs a direct current. . Incidentally, the output is about 2000 Kw.

When a DC power supply is used as the power supply for the electric heating device,
Compared with the case of using single-phase alternating current, there is no inductive obstacle when energized, and as a result, it is not necessary to take measures against inductive obstacle in peripheral devices, and three-phase alternating current can be used as an input power source. The power factor is well-balanced and the power factor can be set to about 100%, so that the electric power can be effectively used. For this reason, it is possible to reduce the facility cost of the entire electric heating device in combination with the reduction of the electric power charge and the need for the countermeasure for the induction failure to the peripheral device.

As will be described later, the control device 7 controls the entire electric heating device 1, that is, the material charging device 2, the heating device 3, the charging / extracting device 4, the conveying device 5, the power supply device 6 and the like at a predetermined timing, and the mounting table. From 20 to carry in the steel material to be heated into the heating device 3, energization heating, after heating, extract the heated steel material from the heating device 3, carry in the extracted steel material into the carrying device 5 and carry into the carrying device 5. A series of operations such as transporting the steel material thus produced to a rolling mill is controlled.

 The operation will be described below.

The electric heating apparatus 1 shown in FIG. 1 is capable of electrically heating a steel material having a maximum length from the length La of the mounting table 20 to the minimum length Lb.

In FIG. 1, first, when an operator turns on a start switch (not shown) of the control device 7, the electric heating device 1
Starts to operate, and the charging mechanism 21 of the material charging device 2 is placed on the mounting table.
Each of the rolls 22b of the insertion line mechanism 22 is moved by sequentially moving the steel materials 300 placed on the 20 in parallel in the arrow F direction.
Place on top and carry in. When the insertion line mechanism 22 is carried into the steel material 300, each roller 22b is rotated to move the steel material 300 to the right in the drawing, and the end surface of the tip 300a is brought into contact with the stopper 22a (indicated by a two-dot chain line in FIG. 11). Position).

The detectors 80 to 85 of the detector 8 (FIG. 11) detect the position of the rear end 300b of the steel material 300 on the insertion line mechanism 22. In this case, the light emitted from the light emitting element 80a of the detector 80 is received by the light receiving element 80b, and as a result, the detection 81 is the rear end 300b.
Does not detect. On the other hand, the light emitted from each light emitting element of the detectors 81 to 85 is blocked by the rear end 300b, and therefore these detectors 81 to 85 detect the rear end 300b. The control device 7 determines that the rear end 300b of the steel material 300 is between the detectors 80 and 81 based on the signals from the detectors 80 to 85. In this way, the control device 7 determines the length of the steel material 300.

Depending on the length of the steel material 300, the insertion / extraction device 4 may be the charging / extractor 40
You can decide to use ~ 41 or not. That is, when the length of the steel material 300 is longer than the position of the detector 81, all the charging and extracting machines 40 to 44 are used, and when the rear end 300b is between the detectors 82 and 83, the charging and extracting is performed. Machines 41-44, using the charge extractor 42-44 when the rear end 300b is between the detectors 84 and 85, and when the rear end 300b is not detected by the detector 85. Use only 43 and 44.

In the above case where the rear end 300b of the steel material 300 is between the detectors 80 and 81, the controller 7 extends the cylinders 222, 224 of the charging extractor 40 as shown by the solid lines in FIGS. 11 and 12. Then, the carriages 221 and 223 are moved forward in the direction indicated by arrow D. On the other hand, the cylinders 226 and 231 of the holder mechanisms 225 and 230 of the carriage 223 are shortened, and the holders 227 and 232 are inserted into the insertion line LN, respectively.
a, located just below the axis LNc of the heating device 3. The other charging / extracting machines 41 to 44 are similarly controlled. Also, the shaft core LNc
Each holder mechanism 45 (FIGS. 11 and 14) located immediately below the cylinder has its cylinder extended so that each roller 262 is aligned at the position of the axis LNc.

The fixed carriage 32 (FIG. 5) has the cylinder 104 shortened, the gantry 103 is moved by the stroke L ₁ thereof in the direction indicated by the arrow B ′, and is retracted from the position of the tip 300a of the steel material 300.
At the same time, each cylinder of each electrode support member 115-118 (Fig. 4)
110 to 113 are shortened, the electrode member 130 is retracted, and the electrode members 131 to 133 are retracted radially outward from the shaft core LNc.
Further, the clamp mechanisms 35, 35 for clamping the movable bus bars 31B, 31B (Figs. 1 and 2) are cylinders 35a, 35a, respectively.
Is shortened to enable movement of each of these moving bus bars 31B, 31B.

The movable carriage 33 (FIGS. 1, 8, and 9) is a motor 153.
Is driven to retreat in the direction indicated by arrow C'to the position indicated by the solid line in FIG. At this time, the movable bus bars 31B, 3
1B slides on the fixed bus bars 31A and 31A and moves together with the moving carriage 33. Further, the pedestal 156 is retracted by the stroke L ₂ thereof due to the shortening of the cylinder 157 and stopped at the position P1 shown by the two-dot chain line in FIGS. 3 and 9. The solenoid valves 212 and 211 (FIG. 10) that control the cylinder 157 are switched to the port 157c side to shorten the cylinder 157. At the same time, the cylinders 165 to 168 of the electrode supporting members 170 to 173 are shortened to retract the electrode members 175, and the electrode members 176 to 178 are retracted outward in the radial direction from the axis LNc.

The cylinder 205 of the extraction mechanism 200 (FIG. 8) is shortened to move the support member 206 to a position just above the axis LNc as shown by the chain double-dashed line. Further, the cylinder 207 is shortened so that the axis L
The tips of the arms 208a, 208a of the clamp mechanism 208 are opened just above Nc (the position of the chain double-dashed line 206 ').

Next, the control device 7 extends the cylinders 226 and 246 of the holder mechanisms 225 and 245 (only the charging and extracting machines 40 and 43 are shown in FIGS. 12 and 13) of the charging and extracting machines 40 to 44 to extend the cylinders 226 and 246, respectively. Holder 227, 2
The steel material 300 on the insertion line mechanism 22 is placed on 47 and lifted to a position slightly higher than the insertion line LNa.
The same applies to the other insertion extractors 41, 42, 44. still,
Since the charging / extracting machines 41 to 42 and 44 operate in the same manner as the charging / extracting machines 40 and 43, the operation of the charging / extracting apparatus 4 will be described with respect to the charging / extracting machines 40 and 43 for convenience of description below.

The control device 7 includes the charging and extracting machines 40 shown in FIGS. 12 and 13,
The cylinders 224 and 242 of 43 are shortened to move the carriages 223 and 241 backward in the direction indicated by arrow E. In this retracted position,
The holders 227 and 247 are located directly above the axis LNc of the heating device 3, and the holders 232 and 252 are located directly above the transfer line LNb. The control unit 7 has the cylinders 226, 246 in this position.
And the steel material 300 on each holder 227, 247 is placed on each roller 262 (FIG. 14) of each holder mechanism 45. In this way, the charging / extracting device 4 carries in the steel material 300 from the charging line mechanism 22 to the position of the axis LNc of the heating device 3.

After this loading, the charging and extracting machines 40 and 43 are connected to the cylinders 226 and 2 respectively.
46 is shortened so that the holders 227 and 247 are slightly lower than the shaft core LNc, and the holders 227 and 247 are advanced again in the direction of the arrow D to move the holders 22 and 247.
Place 7 and 247 directly under the insertion line LNa, and place the holders 232 and 25
2 is controlled so as to be located directly below the axis LNc.

Next, the controller 7 extends the cylinder 104 of the fixed carriage 32 (FIG. 5) to advance the gantry 103 in the direction indicated by the arrow B, and brings the tip of the electrode member 130 into contact with the end surface of the tip 300a of the steel material 300. . At the same time, the control unit 7 controls the moving carriage 33 (Fig. 9).
The motor 153 is driven to move the movable carriage 33 forward at high speed in the direction indicated by arrow C. The movable carriage 33 moves forward and the light emitting elements of the detector 86 arranged on the supporting members 161, 162 (Fig. 8).
The light emitted from 86a to the light receiving element 86b is the rear end 300 of the steel material 300.
When it is cut off by b, the control device 7 detects the rear end 300b, switches the motor 153 from high speed to low speed, and causes the moving carriage 33 to travel at low speed. Next, the light emitting element 87 of the detector 87
When the light emitted from a to the light receiving element 87b is blocked by the rear end 300b, the control device 7 stops the motor 153 and stops the moving carriage 33 at the position.

After stopping the movable carriage 33, the control device 7 extends the cylinder 157 for a certain period of time to move the pedestal 156 forward so that the tip of the electrode member 175 is brought into contact with the end surface of the rear end 300b of the steel material 300. The cylinder 157 stops at the position where the electrode member 157 abuts the rear end surface of the steel material, and the cylinder 157 is not always extended in the entire stroke. The control device 7 has solenoid valves 212, 210 as shown in FIG.
To the port 157b to extend the cylinder 157 as described above, and then connect the solenoid valves 210 and 211 to the atmosphere to connect the ports 157b and 157c of the cylinder 157 to the atmosphere, respectively, and shorten them. To be free.

After stopping the positioning of the movable carriage 33, the controller 7 extends the cylinders 35a, 35a of the clamp mechanisms 35, 35 for fixing the movable busbars 31B, 31B (Figs. 1, 2, 3), and the pads
The movable bus bars 31B, 31B are pressed and fixed to the fixed bus bars 31A, 31A by 35c, 35c, and both are electrically connected. As a result, the position of the moving carriage 33, that is,
It is possible to adjust the length of the moving busbars 31B, 31B according to the length of the steel material 300, and the length of the power feeding conductor can always be set to the minimum length.

After the positioning of the fixed carriage 32 and the movable carriage 33 as described above, the control device 7 controls the cylinders 110 of the electrode support members 115 (Fig. 5) and 170 (Fig. 8) of the carriages 32 and 33, respectively. 165
(Fig. 9) is extended to attach each electrode member 130, 175 to the steel material 300.
The front and rear end surfaces are pressed into contact with each other to securely connect them. At the same time, the cylinders 111 to 113 (FIG. 4) of the electrode support members 116 to 118 and the cylinders 166 to 168 (FIG. 8) of the electrode members 171 to 173 are extended to form the electric members 131 to 13.
3, 176 to 178 are respectively moved in the center, that is, in the direction of the axis LNc, and are pressed into contact with the peripheral surfaces of the front end 300a and the rear end 300b of the steel material 300 at three locations to electrically connect and hold the steel material 300. .

FIG. 7 shows a state in which the electrode members 130 and 131 are pressed against the steel material 300, and the electrode member 130 has its spherical tip 130a at the steel material 300.
Is pressed and point-contacted with the end face of the. Electrode member of mobile carriage 33
Similarly to the electrode 130, the 175 has a spherical tip with a steel material 300.
Is pressed against the end face of. The end surface 131b of the electrode member 131 is in pressure contact and line contact with the side surface of the tip 300a of the steel material 300 along its length d (FIG. 6 (b)) along the axial direction from the end surface position. The contact length of the end surface 131b of the electrode member 131 with the steel material 300 is changed to an appropriate length according to the diameter and material of the steel material 300.

Similarly, the other electrode members 132, 133, 176 to 178 are also pressed against the peripheral surfaces of the front end 300a and the rear end 300b of the steel material 300 at three locations. By using such an electrode member, it is possible to disperse the contact resistance and prevent overheating. Also, each electrode member 131-133 and 17
6 to 178 are pressed onto the peripheral surfaces of the front and rear ends of the steel material 300 from their respective end face positions to thereby press the front end 300a and the rear end 300b.
Can supply a sufficient current.

After the device of the steel material 300 to the heating device 3 is finished as described above, the control device 7 operates the power supply device 6 (Fig. 1) to output a predetermined direct current from the positive electrode terminal 6a, and the fixed bus bar. 31A, 31A → Moving busbar 31B, 31B → Moving carriage 33
Each electrode member 175-178 (Fig. 8) → Steel material 300 → Fixed trolley 3
2 electrode members 130 to 133 (Fig. 4) → connection terminals 36, 36 →
A large DC current is passed through the path of the negative electrode terminal 6b to electrically heat the steel material 300. During this electric heating, the electrode supporting members 117 (FIG. 4) and 171 (8th electrode) of the fixed carriage 32 and the movable carriage 33 are shown.
(Fig.) From each nozzle 135 and 210 including the electric electrode member to the front end 300a and the rear end 300b of the steel material 300 by blowing air to cool the electrode member and the front end 300a,
Prevents abnormal heating of the rear end 300b. This makes steel 30
In 0, the whole is heated to a uniform temperature.

As the steel material 300 is heated, its length is expanded by thermal expansion, and when the length is expanded, the fixed carriage 32 and the movable carriage 33 are extended.
The respective electrode members 130 and 175 are pressed in the axial direction. Fixed trolley
The pedestal 103 of 32 is fixed by a cylinder 1104 so that it cannot be retracted, and each electrode member 1 is pressed against the tip 300a of the steel material 300.
30 to 133 are fixed to the supporting members 105 to 107 and are immovable. On the other hand, the cylinder 157 of the pedestal 156 of the moving carriage 33 is expandable and contractable because the ports 157b and 157c are connected to the atmosphere as described above. In addition, the moving carriage
Each of the 33 electrode members 175 to 178 also fixedly fixes the rear end 300b of the steel material 300. As a result, the cylinder 157 of the moving carriage 33 is shortened by the axial pressing force of the steel material 300 at the time of the extension, and the pedestal 156 retracts according to the extension. That is, the electrode members 175 to 178 are retracted while holding the rear end 300b of the steel material 300 and absorb the change in length due to thermal expansion.

The temperature sensor 88 (Fig. 11) detects the temperature near the tip 300a of the steel material 300 and outputs a corresponding temperature signal. The control signal 7 determines whether or not the temperature of the steel material 300 has reached a predetermined heating temperature based on the temperature signal from the temperature sensor 88, and when the temperature reaches the predetermined temperature, the operation of the power supply device 6 is stopped to stop the steel material 300. Stop energizing to.

After the heating of the steel material 300 is completed, the control device 7 shortens the cylinders 110 to 113 and 165 to 168 of the fixed carriage 32 and the movable carriage 33 to separate the electrode members 130 to 133 and 175 to 178 from the steel material 300. The pedestals 103 and 156 can be moved backward to extract the steel material 300 that has been heated. Control device 7 at the same time
Is the cylinders 226, 231 of the holder mechanisms 225, 230 and 245, 250 of the charging and extracting machines 40 (Fig. 12) and 43 (Fig. 13), respectively.
246 and 251 are extended to each holder 22 of the holder mechanism 225 and 245.
The steel materials 300, which are carried into the insertion line mechanism 22 by 7 and 247 and are to be heated next, are supported, and the heated steel materials 300 are supported by the holders 232 and 252.

Further, the control device 7 controls the extraction mechanism 200 (8th
The cylinder 207 in the figure) is extended to move the support member 206a downward, and the clamp mechanism 208 holds the rear end 300b of the heated steel material 300. As a result, the heated steel material 30
The rear end 300b of 0 is prevented from hanging down by its own weight.

Next, the cylinders 224 and 242 of the insertion extractors 40 and 43 are shortened to retract the carriages 223 and 241 in the arrow E direction, and the holder 22
7 and 247 are placed right above the axis LNc of the heating device 3, and the holder 23
2, 252 is moved to a position directly above the transfer line LNb of the transfer device 5 (FIG. 1), and the cylinder 205 of the extraction mechanism 200 is extended to move the support member 206 directly above the transfer line LNb. Further, each roller 5a of the transport device 5 (FIG. 1) is rotated in the direction of arrow A so that it can be transported.

Next, the controller 7 shortens the cylinders 226, 231 and 246, 251 of the holders 225, 230 and 245, 250 of the charging / extracting machines 40, 43 and supports them on the holders 227, 247. The steel material 300 is placed on each roller 262 of each holder mechanism 45, and the heated steel material 300 supported on the holders 232 and 252 is placed on each roller 5a of the conveying device 5 (FIG. 1). And the cylinder 207 of the support member 206 of the extraction mechanism 200 is shortened to open the clamp mechanism 208 and the rear end 30 of the steel material 300 concerned.
Release 0b. The conveying device 5 conveys the heated steel material 300 carried in on each roller 5a at a high speed in a direction indicated by an arrow A toward a rolling device (not shown) arranged on an extension of the conveying line LNb. To do.

The charging and extracting machines 40 and 43 (Figs. 12 and 13) are again trolleys.
223 and 241 are moved forward in the direction of arrow D to move the holder mechanisms 225 and 2
45 at the position directly below the insertion line LNa of the insertion line mechanism 22,
The holder mechanisms 230 and 250 are placed immediately below the axis LNc of the heating device 3 and stand by. On the other hand, fixed carriage 32 and movable carriage
33 each pedestal 103 and 156, each electrode member 130-133 and 175-1
78 is also driven as described above, and is pressed against the front end 300a and the rear end 300b of the steel material 300 to be heated next.

Such operations are repeated to sequentially heat the steel material 300 placed on the mounting table 20 and convey it to the rolling device.

Further, the steel material 30 mounted on the mounting table 20 of the material charging device 2
When the length of 0 is Lb as shown in FIG. 1, the charging and extracting machines 40 to 42 are 2 in the direction of arrow E in FIG. 12 as described above.
The vehicle is fully retracted to the position indicated by the dotted chain line, and the movable carriage 33 can be advanced to the position P3 (Fig. 3). Of course, at this time, the holder 45 shown in FIG.
The pieces do not work. Therefore, two charging and extracting machines 43, 44 and 2
The individual holder mechanism 45 is driven to carry in and carry out the steel material 300 to and from the heating device 3. Of course, the length L of the steel material 300 is L
In the case of b <L <La, the charging / extracting machine 40 is selected according to the length.
A suitable number of loading and extracting machines and holder mechanisms 45 out of 42 are used.

(Effects of the Invention) As described above, according to the present invention, in the electric heating device that presses the electrode parts to both ends of the member to be heated and energizes and heats the member to be heated, a position near each of the electrode parts. Nozzles are provided so that the nozzles face the respective electrode portions and the respective end portions of the heated member that press-contact the respective electrode portions, and each of the electrode portions and the heated member is heated during electric heating. Since the mist-like cooling medium is jetted to the ends to cool them, it is possible to prevent the electrode part and the end of the heated member from being overcooled, and at the time of energization heating of the heated member, It is possible to prevent local overheating due to the contact resistance of each electrode portion and each end portion of the heated member that pressure-contacts the electrode member. As a result, it becomes possible to heat the member to be heated substantially uniformly over the whole, it is possible to prevent the occurrence of cracks and scratches during rolling, and it is possible to improve the durability of the electrode portion. It has excellent effects such as

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an electric heating apparatus according to the present invention, FIG. 2 is a plan view of a power supply bus bar of FIG. 1,
3 is a side view of FIG. 2, FIG. 4 is a front view of a fixed carriage,
FIG. 5 is a side view of the fixed carriage of FIG. 4, FIG. 6 is a view showing an embodiment of the electrode member, FIG. 7 is an enlarged view of the essential parts showing the relationship between the electrode member and steel material, and FIG. FIG. 9 is a side view of the moving carriage shown in FIG. 8, FIG. 10 is a circuit diagram of a cylinder for driving the mount of the moving carriage shown in FIG. 9, and FIG. 11 is a main part of FIG. FIG. 12 is a side view of the charging and extracting machine of FIG. 11, and FIG. 14 is a side view of FIG. 2 ... Material charging device, 3 ... Heating device, 4 ... Charge extraction device, 5 ... Conveying device, 6 ... Power supply device, 7 ... Control device, 8 ... Detection device, 22 ... Insertion Line mechanism, 30 …… Rail, 31 …… Power supply busbar, 31A …… Fixed busbar, 3
1B: Moving bus bar, 32: Fixed trolley, 33: Moving trolley, 35: Clamping mechanism, 40-44: Charging / extracting machine, 45 ...
… Holder mechanism, 300 …… Steel material.

Claims (1)

[Claims] 1. An electric heating apparatus for heating electrodes by pressing electrode parts on both ends of a member to be heated to energize and heat the members to be heated, and these electrode parts and their respective electrodes in the vicinity of the electrode parts. Nozzles are arranged so that the nozzles face the respective end portions of the heated member that presses the parts, and mist-like cooling is performed on the electrode portions and the end portions of the heated member during electric heating. An electric heating device characterized in that a medium is jetted and cooled.