JP3049868B2 - Electrode extension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode extension device which prevents an extra weight from being applied to a nipple screwed to an electrode and prevents breakage of a screw in a socket portion of the electrode.

[0002]

2. Description of the Related Art If an attempt is made to manually extend electrodes used in an arc furnace for steel making, etc., the working environment is poor, and it is difficult to tighten the large-sized electrodes due to the increase in the size of the arc furnace. This causes a problem that the electrode is easily broken or the like. For this reason, an electrode extension device has been used.

FIG. 2 shows an example of a conventionally used electrode extension device. A cylindrical frame 2 is fixed to a frame 1 which can be raised and run by appropriate means. The cylindrical guide 3 of the electrode extension device main body is fixed in the vertical direction inside the electrode. A cylindrical slider 4 is slidably fitted to the guide 3, and a turning motor 6 mounted on the upper end of the slider 4 is connected to a turning shaft 6 for screwing. 4 is supported by a bearing 7 fitted into the hollow portion. A universal joint 8 is connected to the turning shaft 6, and a nipple 9 having a male screw is attached to a lower end of the universal joint 8. The upper end of a hydraulic cylinder 10 for screw feed is connected to the outside of the slider 4, and the lower end of the piston rod of the hydraulic cylinder 10 is connected to the inside of the frame 2.

On the other hand, an electromagnetic switching valve 14 is provided at the end of a pipeline 13 connected to the discharge side of a hydraulic pump 12 driven by a motor 11, and the electromagnetic switching valve 14 is connected to an ascending pipeline 15 And a descending line 16, a line 17 for returning oil to the tank 18 is connected, an ascending line 15 is connected to the piston rod side of the hydraulic cylinder 10, and the descending line 16 is connected to the hydraulic cylinder. 10, a bypass circuit 22 having a relief valve 19, an electromagnetic switching valve 20, and a check valve 21 connected between the ascending pipe 15 and the descending pipe 16. Electromagnetic switching valve 2
A pipe 23 for returning oil to the tank 18 is connected between 0 and the check valve 21.

The set pressure of the above-described relief valve 19 is determined by using only the own weight of the lifting / lowering portion including the slider 4, the rotating motor 5, the rotating shaft 6, the bearing 7, the universal joint 8, and the nipple 9 of the electrode extension device. Is set to a pressure that can be maintained.

In FIG. 2, reference numeral 24 denotes an electrode holder,
25 is an electrode on the arc furnace side, and 26 is a new electrode to be added.

Next, in the conventional apparatus shown in FIG.
The operation when a new electrode 26 is added to the electrode 25 on the arc furnace side will be described.

Before adding a new electrode 26, the electrode holder 24 clamps the electrode 25 on the furnace side as shown by a virtual line. The nipple 9 of the electrode extension device is screwed into the female screw hole at the upper end of the electrode 26 with respect to the new electrode 26 at the take-out position (not shown), and the electromagnetic switching valve 14 is switched to the lower position. 1
The hydraulic cylinder 10 is moved up in a state in which the hydraulic cylinders 10 and 3 are communicated with the ascending pipeline 15 and the descending pipeline 16, and the slider 4
To rise.

Next, the frame 1 is moved to the furnace side electrode 25.
After the central axis of the new electrode 26 is adjusted, the turning motor 5 is driven to rotate the new electrode 26 via the turning shaft 6 and the universal joint 8, and the electromagnetic switching valve 14 is switched to the lower position, so that the pipeline The slider 4 is lowered in a state where the lower pipe 13 and the lower pipe 16 are communicated with the lower pipe 13, and the nipple 9 at the lower end of the new electrode 26 is screwed into the female screw hole at the upper end of the electrode 25. A new electrode 26 is added to the electrode 25 on the furnace side.

When the extension of the new electrode 26 is completed, the driving of the turning motor 5 is stopped, and a timer is used to turn on the electromagnetic switching valve 14.
Is moved to the lower position for a certain period of time to raise the slider 4 slightly, and the hydraulic cylinder 10
6 when the weight of the solenoid-operated switching valve 14
Is switched to the close position by the timer, and the lifting of the slider 4 is stopped.

Next, the electrode holder 2 located at the position of the virtual line
4 is unclamped by the timer and rises to the position shown by the solid line to perform a holding operation for clamping a new electrode 26.

Next, when the electromagnetic switching valve 20 is opened for a certain period of time by a timer, the pressure in the hydraulic cylinder 10 is higher than the set pressure of the relief valve 19 by the weight of the electrodes 25 and 26. A part of the oil is supplied from the relief valve 19 of the bypass circuit 22 and the electromagnetic switching valve 20 to the line 23.
The hydraulic cylinder 10 returns to the tank 18 through the position where the electrode holder 24 holds the weight of the electrodes 25 and 26,
That is, it descends to a position 24 'where the weight of the electrodes 25 and 26 and the deflection of the electrode holder 24 are balanced, and stops.

Thereafter, the electromagnetic switching valve 20 is closed by the operation of the timer, and the electromagnetic switching valve 14 is switched to supply the hydraulic oil from the hydraulic pump 12 to the hydraulic cylinder 10 through the ascending pipe 15 and to rotate the motor 5. Is driven to rotate the nipple 9, and the nipple 9 is inserted through the female screw hole of the electrode 26.
Extract.

At this time, since the weights of the electrodes 25 and 26 are supported by the electrode holder 24, no weight load is applied to the female screw of the electrode 26, so that the female screw hole of the electrode 26 is not damaged.

[0015]

In the conventional electrode extension device, since the raising and lowering portions of the slider 4 and the like are raised for a predetermined time by a timer, the electrode holding operation of the electrode holder 24 is performed. Even when the electrode extension device does not rise due to the occurrence of, the timer starts to change the electrode holder 24 after a certain period of time by the timer,
At the moment when the electrode holder 24 unclamps the electrode 25, the electrode 25 supported by the electrode holder 24
Weight was applied to the nipple 9, and the electrode holder 24 that was bent by the weight of the electrode 25 was not bent.

Further, in the conventional apparatus, the hydraulic switching valve 20 which opens the hydraulic oil on the side of the ascending side pipe line 15 of the hydraulic cylinder 10 for a certain period of time by a timer operates the relief valve 1.
Since the nipple 9 is removed after the slider 4 is lowered by the relief at 9 and the nipple 9 is removed, even if a failure occurs in the device and the electrode replenishment device does not lower, the nipple 9 is not removed after a predetermined time by the timer. In order to enter the removal operation of
The deflection of the electrode holder 24 causes the nipple 9 to move
In some cases, an impact was generated at the moment when the female screw was removed from the inner surface of the electrode 26, and the female screw of the electrode 26 was sometimes damaged.

The present invention eliminates such conventional disadvantages,
It is an object of the present invention to provide an electrode replenishing apparatus that prevents an electrode from being damaged when an electrode holder performs a switching operation or removes a nipple, thereby preventing damage to the electrode.

[0018]

SUMMARY OF THE INVENTION An electrode extension device according to the present invention has a rotatable nipple screwed to an electrode and moves up and down to extend a new electrode to an electrode supported by an electrode holder. Lifting unit, a lifting device for raising and lowering the lifting unit, and a load applied to the lifting device when the lifting unit rises in a state where the new electrode is added, the weight of the electrode of the lifting unit and the weight of the electrode. First load detecting means for stopping the lifting operation of the lifting device when the sum is substantially equal to the sum, and when the load applied to the lifting device when the lifting unit is lowered becomes substantially equal to the own weight of the lifting unit. And a second load detecting means for stopping the lowering operation of the lifting device.

[0019]

When the elevating portion of the electrode extension device rises, the first load detecting means confirms that the weight of the electrode is supported by the electrode extension device, stops the elevation of the elevating portion, and stops the electrode holder. When the lifting part of the electrode extension device descends, the second load detecting means confirms that the weight of the electrode is supported by the electrode holder. Remove operation.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram of one embodiment of the present invention. An electrode extension device 30 includes an elevating unit 31 and a turning unit 32.
, An extension arm 33 and a nipple 34, and the elevating unit 31 is moved up and down by an elevating device 35 such as a hydraulic cylinder.

The swivel part 32 is provided at the upper end of the elevating part 31 and can be horizontally swiveled by a hydraulic motor 36 for swiveling. The extension arm 33 is slidable on one side of the swivel part 32. , And extend and contract horizontally by a hydraulic cylinder 37 for expansion and contraction provided inside the turning portion 32. The nipple 34 has a male screw that is screwed into the female screw of the electrode, is provided downward at the tip of the extension arm 33, and is rotated by a hydraulic motor 38.

An electrode support arm 39 is provided on the arc furnace side so as to be able to move up and down by a winch 40. At the tip of the electrode support arm 39, an electrode holder 41 for clamping and unclamping an electrode is mounted. ing.

On the other hand, an electromagnetic switching valve 44 is provided at the tip of a pipe 43 connected to the discharge side of the hydraulic pump 42, and the electromagnetic switching valve 44 has an ascending pipe 45 and a descending pipe 4.
6 and a pipe 48 for returning oil to the tank 47. The ascending pipeline 45 is connected to the piston rod side of the elevating device 35, and a counterbalance valve 49 and a check valve 50 are mounted in parallel in the ascending pipeline 45. The counterbalance valve 49 holds the pressure so that the elevating device 35 does not descend naturally, and the check valve 50 operates from the electromagnetic switching valve 44 to the elevating device 35.
Flow the pressure oil only to the
4 to prevent the flow of oil. The descending pipeline 46 is connected to the piston rod side of the elevating device 35.

Elevating device 35 and counterbalance valve 49
A bypass circuit 54 having a relief valve 51, a variable throttle 52, and an electromagnetic switching valve 53 is connected between the ascending pipe 45 and the descending pipe 46 which are connected to the check valve 50. ing. The set pressure of the relief valve 51 is slightly lower than the pressure at which the lifting device 35 can hold the weight of the lifting portion 31 including the weight of the nipple 34, the hydraulic motor 38, the extending arm 33, and the turning portion 32 of the electrode adding device 30. It is set to relieve by pressure.

Elevating device 35 and counterbalance valve 49
A first load detecting means 55 and a second load detecting means 56 each composed of a pressure switch or the like are connected to the ascending-side pipeline 45 on the side connecting the check valve 50 and the check valve 50. The first load detection unit 55 is configured to control the load applied to the lifting device 35 by the nipple 34 of the electrode extension device 30,
When it is detected that the weight of the lifting / lowering portion 31 including the weights of the hydraulic motor 38, the extension arm 33, and the turning portion 32 and the weight of the electrodes 25 and 26 have become substantially equal, the electromagnetic switching valve 4
4 is switched to the closed position. The second load detecting means 56 determines whether the load applied to the lifting device 35 is equal to the weight of the lifting portion 31 including the weights of the nipple 34, the hydraulic motor 38, the extending arm 33, and the turning portion 32 of the electrode adding device 30. Is detected, and the electromagnetic switching valve 53 is closed.

Next, the operation of the apparatus shown in FIG. 1 will be described.

Before adding a new electrode 26, the electrode support arm 39 is in the lowered position as shown by a solid line, and the electrode holder 41 clamps the electrode 25 on the furnace side. With the new electrode 26 at the extraction position, the electrode 2
The nipple 34 is screwed into the female screw hole at the upper end of the valve 6, and the electromagnetic switching valve 44 is switched so as to move to the right in FIG. It extends, raises and lowers the elevating part 31, and lifts a new electrode 26 with the nipple 34.

Next, the turning section 32 is driven by the hydraulic motor 36.
While the arm 33 is extended by the hydraulic cylinder 37 and the new electrode 2 is placed on the electrode 25 on the furnace side.
6 Align the central axes. Then, the hydraulic motor 38 is driven to rotate the new electrode 26 and the electromagnetic switching valve 4
4 is switched to the left, and the lines 43 and 4 are switched.
6, 48 and 45 are communicated, the lifting device 35 is reduced, the lifting unit 31 is lowered, and the nipple at the lower end of the new electrode 26 is screwed into the female screw hole at the upper end of the electrode 25, and the electrode on the furnace side is turned on. A new electrode 26 is added to 25.

When the extension of the new electrode 26 is completed, the drive of the hydraulic motor 38 is stopped to stop the rotation of the electrode 26,
The electromagnetic switching valve 44 is switched so as to move to the right, the pipes 43 and 45 and the pipes 48 and 46 are in communication with each other, the elevating device 35 is extended, and the elevating unit 31 is raised.

The load applied to the lifting / lowering device 35 depends on the weight of the lifting / lowering portion 31 including the weight of the nipple 34, the hydraulic motor 38, the extending arm 33, and the turning portion 32 of the electrode adding device 30, and the electrodes 25 and 26. When the load becomes substantially equal to the sum of the weights, the first load detecting means 55 detects this, switches the electromagnetic switching valve 44 to the illustrated closed position, and stops the raising and lowering portion 31 from rising.

Next, the electrode support arm 39 and the electrode holder 41 are raised by the winch 40 while the electrode holder 41 at the position shown by the solid line is unclamped. When the electrode holder 41 is unclamped, the weights of the electrodes 25 and 26 are supported by the lifting / lowering device 35 together with the weight of the lifting / lowering portion 31, so that the bending of the extension arm 33 does not change.
No impact occurs.

The unclamped electrode holder 41 is raised together with the electrode support arm 39 to the position indicated by the imaginary line, the winch 40 is stopped, and the electrode 26 is clamped by the electrode holder 41. When the electromagnetic switching valve 53 is excited and opened, the hydraulic oil on the side opposite to the piston rod of the elevating device 35 is supplied to the relief valve 51, the variable throttle 52, and the electromagnetic switching valve 5.
3. Discharged to the tank 47 through the bypass circuit 54,
The elevating unit 31 descends gradually.

When the load applied to the lifting device becomes substantially equal to the weight of the lifting portion 31 including the weight of the nipple 34, the hydraulic motor 38, the extending arm 33, and the turning portion 32 of the electrode adding device 30, the second The load detecting means 56 detects this, switches the electromagnetic switching valve 44 to the closed position, and stops the lowering of the elevating unit 31.

Next, the nipple 34 is driven by the hydraulic motor 38.
The electromagnetic switching valve 44 is switched while rotating in a direction to loosen the nozzle, the elevating unit 31 is raised, and the nipple 34 is wiped from the female screw hole of the electrode 26. When the nipple 34 is removed, the weight of the electrodes 25 and 26 is not applied to the nipple 34 or the extension arm 33 because the electrode holder 41 and the electrode support arm 39 support the weight of the electrodes 25 and 26 at the moment when the nipple 34 comes off the electrode 26. No impact occurs.

In the embodiment shown in FIG. 1, the lifting device 35 is of a hydraulic type.
Can be an electric type using an electric rack or a pinion, or a pneumatic type. As the first load detecting means 55 and the second load detecting means 56, not only a pressure switch but also a pressure sensor, a pressure setting device, and a load cell can be used.

[0037]

In the conventional apparatus, even if the weight of the electrode does not shift to the electrode extension apparatus side or the electrode holder side, the movement of the load is considered to be completed after a certain time by the timer. When there was a failure, an impact occurred, causing damage such as screw damage to the electrode.However, the present invention can reliably detect whether the electrode weight is loaded on the electrode extension device or not, so that the impact can be detected. There is no occurrence of troubles such as breakage of the screw of the electrode.

[Brief description of the drawings]

FIG. 1 is a system diagram of one embodiment of the present invention.

FIG. 2 is a system diagram of a conventional device.

[Explanation of symbols]

 25 electrode 26 new electrode 30 electrode extension device 31 elevating unit 34 nipple 35 elevating device 41 electrode holder 55 first load detecting means 56 second load detecting means

Claims (1)

(57) [Claims] 1. An elevating and lowering part of an electrode extension device for elevating and lowering a rotatable nipple screwed to an electrode and adding a new electrode to an electrode supported by an electrode holder, and an elevating and lowering device for elevating the elevating part And raising and lowering the lifting device when the load applied to the lifting device when the lifting unit is raised in the state where the new electrode is added becomes substantially equal to the sum of the weight of the lifting unit and the weight of the electrode. A first load detecting means for stopping the lifting and lowering means, and a second load for stopping the lowering operation of the lifting and lowering apparatus when the load applied to the lifting and lowering section when the lifting and lowering section lowers becomes substantially equal to the weight of the lifting and lowering section. An electrode extension device, comprising: a detection unit.