JP7228358B2 - Ingot charging device and manufacturing method of hot-dip plated metal strip - Google Patents

Description

The present invention relates to an ingot charging device for charging an ingot into a molten metal bath in which a metal strip is immersed, and a method for producing a hot-dip plated metal strip.

Generally, in a facility for manufacturing a plated metal strip, the metal strip is withdrawn from the molten metal bath after the metal strip is immersed in the molten metal bath. Molten metal is adhered to the surface of the metal strip pulled up from the molten metal bath, and a plating layer is formed on the surface of the metal strip by solidifying the molten metal.

As described above, since the molten metal adheres to the surface of the metal band pulled up from the molten metal bath, ingots (metal lumps) are thrown into the molten metal bath to maintain the molten metal bath. Conventionally used ingot charging devices of this type include, for example, the configuration disclosed in Patent Document 1 below. That is, in the conventional ingot charging device, the gripping part grips the ingot and lowers the gripping part at a constant speed to drop the ingot into the molten metal bath.

JP 2010-174309 A

In the conventional ingot charging apparatus as described above, the gripper is lowered at a constant speed to charge the ingot into the molten metal bath. Therefore, when the gripping portion descends at a high speed, the surface of the molten metal bath fluctuates greatly when the ingot is charged. If the hot water surface fluctuates significantly, there is a risk that the dross adhered to the equipment immersed in the bath will peel off and adhere to the metal strip. If the dross adheres to the metal strip, quality defects will occur in the hot dip plated metal strip. On the other hand, if the lowering speed of the gripper is slow, it takes a long time to charge the ingot, and there is a possibility that the molten metal bath cannot be maintained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to suppress fluctuations in the surface of the molten metal bath and to more reliably maintain the molten metal bath. It is an object of the present invention to provide an apparatus and method for manufacturing a hot dip plated metal strip.

An ingot charging device according to the present invention is an ingot charging device for charging an ingot into a molten metal bath in which a metal strip is immersed. a sensor for detecting the lifting position of the gripping part; a control part for controlling the lifting operation of the lifting part based on a signal from the sensor; and an input part for inputting a command to the control part , When the gripping portion is lowered to drop the ingot into the molten metal bath, the control portion lowers the gripping portion when the vertical position of the gripping portion reaches a predetermined deceleration position before the lower end of the ingot comes into contact with the molten metal bath. is decelerated, and the ingot is thrown into the molten metal bath at the decelerated speed , and the control unit determines the descending speed of the gripper after deceleration based on the command from the input unit.

A method for producing a hot-dip plated metal strip according to the present invention is a method for producing a hot-dip plated metal strip by immersing the metal strip in a molten metal bath. including throwing ingots into

According to the ingot charging device and the hot-dip plated metal band manufacturing method of the present invention, when the gripping part is lowered to cast the ingot into the molten metal bath, the control part moves the lifting position of the gripping part to the predetermined deceleration position. When the temperature rises, the descent of the gripping part is decelerated, and the ingot is thrown into the molten metal bath at the decelerated speed, so that fluctuations in the surface of the molten metal bath can be suppressed and the molten metal bath can be maintained more reliably. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the hot-dip-plating equipment by embodiment of this invention. FIG. 2 is a plan view showing the hot-dip plating equipment of FIG. 1; 2 is a flow chart showing operation control of an ingot charging device by a control unit in FIG. 1; FIG. 4 is an explanatory diagram showing an example of a velocity profile when the gripper is lowered in the closing control of FIG. 3; FIG. 2 is a front view showing the grip part of FIG. 1; FIG. 6 is an explanatory view showing a state in which the gripping of the ingot by the gripping portion of FIG. 5 is released; FIG. 2 is a front view showing the lifting section of FIG. 1 in more detail; FIG. 8 is an explanatory view showing a state in which the holding part is lifted by the lifting part of FIG. 7;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with reference to drawings. The present invention is not limited to each embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components of different embodiments may be combined as appropriate.

FIG. 1 is a front view showing a hot dipping equipment according to an embodiment of the present invention, and FIG. 2 is a plan view showing the hot dipping equipment of FIG. The hot-dip plating equipment shown in FIGS. 1 and 2 is equipment for manufacturing a hot-dip plated metal strip 2 by hot-dip plating a metal strip 1 . A steel plate can be used as the metal strip 1 . However, a metal strip other than the steel plate may be used as the metal strip 1 .

As shown in FIGS. 1 and 2, the hot dipping equipment of this embodiment has a molten metal bath 3, a sink roll 4 and an ingot charging device 5. As shown in FIG.

The molten metal bath 3 is molten metal stored in a pot 30 . As the molten metal bath 3, for example, a molten Zn-Al-Mg alloy bath, a molten Zn-Al alloy bath, a molten Zn bath, a molten Al bath, or the like can be used. The sink roll 4 is a roll immersed in the molten metal bath 3 . After being immersed in the molten metal bath 3 , the metal strip 1 is pulled up from the molten metal bath 3 by changing the conveying direction by the sink rolls 4 . Molten metal adheres to the surface of the metal strip 1 pulled up from the molten metal bath 3 . By solidifying the molten metal adhered to the surface of the metal strip 1, the hot-dip plated metal strip 2 having a plating layer on the surface is manufactured.

Since the molten metal adheres to the surface of the metal strip 1 pulled up from the molten metal bath 3 as described above, it is necessary to supply the molten metal bath 3 with metal as needed to maintain the molten metal bath 3 . In the hot-dip plating equipment of the present embodiment, the molten metal bath 3 is maintained by feeding ingots 6 (metal lumps) into the molten metal bath 3 by the ingot feeding device 5 at any time.

When the molten metal bath 3 is composed of an alloy, the ingot 6 may be an alloy ingot whose components are arranged in advance, or a metal ingot of each component (for example, a Zn ingot, Al lumps and Mg lumps).

The ingot charging device 5 of the present embodiment has a first conveying section 51, a second conveying section 52, an elevating section 53, a gripping section 54, a first sensor 55, a second sensor 56, a control section 57 and an input section 58. are doing.

The first conveying unit 51 is a device for conveying the ingot 6 to a preparation position 60 provided near the pot 30 in which the molten metal bath 3 is stored. As the first transport unit 51, a device such as a roller conveyor can be used, for example.

The second transport section 52 is a device for transporting the lift section 53 and the grip section 54 between above the preparation position 60 and above the pot 30 . The second conveying unit 52 is provided with a rail 520 extending between above the preparation position 60 and above the pot 30 and a movable body 521 that is guided by the rail 520 and movable.

The lifting section 53 is a device for connecting the movable body 521 of the second conveying section 52 and the gripping section 54 and for moving the gripping section 54 up and down.

The gripper 54 is a device for gripping and lifting the ingot 6 . The gripping portion 54 is supported by the second conveying portion 52 via the elevating portion 53 and is movable together with the elevating portion 53 between above the preparation position 60 and above the pot 30 . Further, the gripping portion 54 can be moved up and down by the lifting portion 53 .

As particularly shown in FIG. 2, the grip portion 54 of this embodiment has two pairs of claws 541 and 542 which are provided so as to be openable and closable. The two pairs of claws 541 and 542 are spaced apart from each other in the depth direction 6 a of the ingot 6 positioned at the preparation position 60 . Each pair of claws 541 and 542 is provided so that the tips of each pair of claws 541 and 542 can rotate in the width direction 6b of the ingot 6 in directions toward and away from each other. When the two pairs of claws 541 and 542 are closed (that is, when the tips of the claws 541 and 542 of each pair are rotated in the width direction 6b of the ingot 6, the gripping portion 54 of the present embodiment approaches each other. The ingot 6 is gripped by these two pairs of claws 541 and 542 when the ingot is pressed.

The first and second sensors 55 and 56 are for detecting the elevation position of the grip portion 54 . The first and second sensors 55 and 56 of this embodiment detect different physical quantities. The first sensor 55 of this embodiment measures the distance from the reference position to the grip portion 54 . The distance from the reference position to the gripping portion 54 corresponds to the elevation position of the gripping portion 54 . The first sensor 55 of the present embodiment has a main body 55a fixed to the movable body 521 and a wire 55b extending from the main body 55a and attached to the grip portion 54 at its tip. The extension amount of 55b (the distance from the movable body 521 to the grip portion 54) is measured. From the viewpoint of being able to measure the distance to the grip portion 54 more directly, it is preferable to use a sensor mechanically connected to the grip portion 54 like the first sensor 55 of the present embodiment. A non-contact type rangefinder, such as a type or sound wave type, may be used as the first sensor 55 . The second sensor 56 of the present embodiment measures the elapsed time from when the grip portion 54 starts to move up and down. Since the lifting and lowering of the gripping portion 54 is performed according to a predetermined speed profile, the lifting position of the gripping portion 54 can be obtained based on the above-described elapsed time.

The control unit 57 is composed of a computer or the like that performs arithmetic processing based on a program, for example, and controls the operation of each component of the ingot charging device 5 .

The input unit 58 is composed of devices such as an operation panel and a keyboard, and inputs commands to the control unit 57 according to operations by an operator.

Next, FIG. 3 is a flow chart showing operation control of the ingot charging device 5 by the control unit 57 of FIG. As shown in FIG. 3, when the control unit 57 starts controlling the operation of the ingot charging device 5, the control unit 57 performs preparation control (step S1), transport control (step S2), and charging control (step S3). Do in order.

In preparation control (step S<b>1 ), the control section 57 controls the operation of the first conveying section 51 to convey the ingot 6 to the preparation position 60 . Further, the control unit 57 controls the operation of the second conveying unit 52 to convey the lifting unit 53 and the gripping unit 54 above the preparation position 60 . Furthermore, after transporting the lifting section 53 and the gripping section 54 above the preparation position 60, the control section 57 controls the lifting operation of the lifting section 53 based on the signals from the first and second sensors 55 and 56. to lower the gripper 54 to the vicinity of the ingot 6 . Furthermore, after lowering the gripper 54 to the vicinity of the ingot 6 , the controller 57 controls opening and closing of the claws 541 and 542 to allow the gripper 54 to grip the ingot 6 .

In the transport control (step S<b>2 ), the control unit 57 controls the operation of the second transport unit 52 to transport the lifting unit 53 and the gripping unit 54 above the pot 30 . Note that the control unit 57 may control the up-and-down operation of the elevating unit 53 to raise the gripping unit 54 after causing the gripping unit 54 to grip the ingot 6 .

In the charging control (step S3), the lifting operation of the lifting section 53 is controlled based on the signals from the first and second sensors 55 and 56, and the grip section 54 is lowered to charge the ingot 6 into the molten metal bath 3. do.

The operation control of the ingot charging device 5 by the control unit 57 is repeatedly performed. That is, the control unit 57 appropriately performs the preparation control (step S1) again after the closing control (step S3) is completed.

Preparation control (step S1), etc., does not necessarily have to be performed immediately after the closing control (step S3) ends, and there is a rest time between the closing of closing control (step S3) and the preparation control (step S1), etc. may Conveyance control of the ingot 6 to the preparation position 60 by the first conveying section 51 may be performed in parallel with operation control of the second conveying section 52 , the lifting section 53 and the gripping section 54 . That is, the first transport section 51 may transport the ingot 6 to the preparation position 60 during the transport control (step S2) and the loading control (step S3).

Next, FIG. 4 is an explanatory diagram showing an example of a speed profile when the gripper 54 is lowered in the closing control of FIG. The horizontal axis of FIG. 4 is the elevation position of the gripping portion 54 (the distance from the descent start position to the gripping portion 54), and the vertical axis of FIG.

The control unit 57 of the present embodiment raises and lowers the gripping portion 54 based on the signals from the first and second sensors 55 and 56 when the gripping portion 54 is lowered to drop the ingot 6 into the molten metal bath 3 . I'm watching your location.

When the gripping portion 54 is lowered to drop the ingot 6 into the molten metal bath 3, the control portion 57 of the present embodiment lowers the gripping portion 54 when the lifting position of the gripping portion 54 reaches a predetermined deceleration position. is decelerated, and the ingot 6 is thrown into the molten metal bath 3 at the decelerated speed. In other words, the controller 57 of the present embodiment lowers the gripper 54 at the first speed from the descent start position to the predetermined deceleration position (first deceleration position), and the lift position of the gripper 54 is set at the predetermined speed. When the deceleration position is reached, the descent of the gripper 54 is decelerated to a second speed that is slower than the first speed.

If the gripper 54 is lowered while maintaining the high first speed to charge the ingot 6 into the molten metal bath 3, the time required to charge the ingot 6 into the molten metal bath 3 can be shortened. However, when the ingot is charged at the first speed, the surface of the molten metal bath 3 may fluctuate greatly when the ingot 6 is charged. If the surface of the molten metal bath 3 fluctuates greatly, there is a risk that the dross adhered to the equipment immersed in the bath will peel off and adhere to the metal strip 1 . If the dross adheres to the metal strip 1, the quality of the hot dip plated metal strip 2 will be abnormal. This quality abnormality is conspicuous when the molten metal bath 3 is a molten Zn--Al--Mg alloy bath.

On the other hand, if the gripper 54 is lowered from the descent start position at the second speed, it is possible to avoid large fluctuations in the surface of the molten metal bath 3 when the ingot 6 is charged. However, if the gripper 54 is lowered from the descent start position at the second speed, the time required to drop the ingot 6 into the molten metal bath 3 becomes longer, which may hinder the maintenance of the molten metal bath 3 . .

Therefore, in the present embodiment, as described above, the gripping portion 54 is lowered at a relatively high speed until the lifting position of the gripping portion 54 reaches the predetermined deceleration position. By decelerating the descent of the gripper 54 when it reaches the position and throwing the ingot 6 into the molten metal bath 3 at the decelerated speed, it is possible to suppress fluctuations in the surface of the molten metal bath 3 and more reliably. to maintain the molten metal bath at This configuration is particularly useful when the molten metal bath 3 is a molten Zn--Al--Mg alloy bath.

The deceleration position is a position below the descent start position of the gripper 54 and before the lower end of the ingot 6 comes into contact with the molten metal bath 3 . Further, the distance between the deceleration position and the surface of the molten metal bath 3 is the distance that allows the lowering speed of the gripper 54 to be reduced to a predetermined speed (second speed) before the lower end of the ingot 6 contacts the molten metal bath 3. and is determined according to the deceleration of the gripping portion 54 .

As will be described later in detail, the lifting section 53 of the present embodiment lifts and lowers the grip section 54 by the driving force of a motor 538 (see FIG. 7). The control unit 57 of the present embodiment includes an inverter that controls power supplied to the lifting unit 53 (motor 538), and the gripping unit 54 is decelerated as described above by power control by the inverter. However, the deceleration of the gripper 54 may be effected by other methods such as, for example, a braking mechanism or switching of gears provided between the motor and other components.

The control unit 57 of the present embodiment determines the speed (second speed) of the gripping unit 54 after deceleration based on a command from the input unit 58 . Specifically, a plurality of speed candidates are set in advance as the speed (second speed) of the gripping portion 54 after deceleration. A speed (second speed) of the gripping portion 54 after deceleration is determined. The dashed-dotted line in FIG. 4 indicates that there is a second speed different from the second speed indicated by the solid line.

The signal used by the control unit 57 of the present embodiment to control the lifting operation of the lifting unit 53 can be switched between the signal from the first sensor 55 and the signal from the second sensor 56 . Based on a command from the input unit 58, the control unit 57 selects either the signal from the first sensor 55 or the signal from the second sensor 56 as the signal used to control the lifting operation of the lifting unit 53. decide. However, the control unit 57 has a function to determine whether or not there is an abnormality in the signals of the first and second sensors 55 and 56. The control unit 57 may switch the signal used for control to the signal of the other of the first and second sensors 55 and 56 when it is determined that is occurring.

The control unit 57 of the present embodiment further decelerates the descent of the gripping unit 54 and stops the lifting of the gripping unit 54 when the lifting position of the gripping unit 54 reaches a predetermined stop position (second deceleration position). The upper surface of the ingot 6 is positioned below the surface of the molten metal bath 3 when the gripping portion 54 is stopped moving up and down. The stopping position may be a position before the upper surface of the ingot 6 enters the surface of the molten metal bath 3, or a position after the upper surface of the ingot 6 enters the surface of the molten metal bath 3. good too.

After stopping the lifting and lowering of the gripping portion 54, the control portion 57 of the present embodiment keeps the lifting and lowering of the gripping portion 54 stopped (the state in which the ingot 6 is immersed in the molten metal bath 3) for a predetermined time. After that, the lifting operation of the lifting section 53 is controlled to lift the grip section 54 . The controller 57 of the present embodiment opens and closes the two pairs of claws 541 and 542 of the gripper 54 a plurality of times after the ingot 6 is thrown into the molten metal bath 3 and before the gripper 54 is raised. By opening and closing the two pairs of claws 541 and 542 a plurality of times, it is possible to reliably prevent the grasping portion 54 from being lifted while the ingot 6 is caught by the claws 541 and 542 .

Next, the grip portion 54 of FIG. 1 will be described in more detail with reference to FIGS. 5 and 6. FIG. FIG. 5 is a front view of the gripping portion 54 of FIG. 1, showing a state in which the ingot 6 is gripped by the gripping portion 54. As shown in FIG. FIG. 6 is an explanatory view showing a state in which the gripping of the ingot 6 by the gripping portion 54 of FIG. 5 is released. 5 and 6 show only a pair of claws 541 out of the two pairs of claws 541 and 542. FIG.

As shown in FIGS. 5 and 6 , the grip portion 54 has a grip portion base body 540 , a pair of claws 541 , a connecting plate 543 and an actuator 544 . One of the pair of claws 541 is called first claw 546 and the other is called second claw 547 .

The grip portion base body 540 is a structure extending in the depth direction 6 a and the width direction 6 b of the ingot 6 . A pair of claws 541 are arranged on one end side of the grip portion base body 540 in the depth direction 6a, and another pair of claws 542 (see FIG. 2) are arranged on the other end side of the grip portion base body 540 .

The first and second claws 546, 547 are rotatably attached to the grip portion base body 540 about shafts 546a, 547a. The shafts 546 a and 547 a pass through the grip portion base 540 to the other end side of the grip portion base 540 . Another pair of claws 542 (see FIG. 2) arranged on the other end side of the grip portion base body 540 share the shafts 546a and 547a with the first and second claws 546 and 547. It is rotatable integrally with the two claws 546 and 547 .

The first and second claws 546, 547 have claw bases 546b, 547b and claw tips 546c, 547c.

The claw bases 546b, 547b are L-shaped members, and include _bases 546b ₀ , 547b ₀ , first projections 546b ₁ , 547b ₁ and second projections 546b ₂ projecting from the bases 546b ₀ , 547b 0 . , 547b ₂ . The angle between the direction in which the first projections _{546b 1 and} 547b ₁ project from the bases 546b _{0 and} 547b ₀ and the direction in which the second projections 546b ₂ and 547b ₂ project from the bases 546b 0 and 547b 0 is approximately 90°. It is said that

Between the bases 546b ₀ , 547b ₀ and the tips of the first protrusions 546b ₁ , 547b ₁ , the shafts 546a, 547a are fixed. A connecting plate 543 is rotatably attached to the ends of the first protrusions 546b ₁ and 547b ₁ . An actuator 544 is attached to the tip of the second projections 546b ₂ and 547b ₂ . As the movable piece of the actuator 544 advances and retreats, the second claw 547 rotates around the shaft 547a. When the rotation of the second claw 547 is transmitted to the first claw 546 via the connecting plate 543, the first claw 546 is rotated around the shaft 546a. A hydraulic cylinder or the like can be used as the actuator 544 .

The claw tip portions 546c and 547c are detachably attached to the base portions 546b ₀ and 547b ₀ of the claw base bodies 546b and 547b. The claw tips 546 c and 547 c are immersed in the molten metal bath 3 together with the ingot 6 when the ingot 6 is thrown into the molten metal bath 3 . Immersion in the molten metal bath 3 may deteriorate the claw tip portions 546c and 547c. Since the claw tip portions 546c, 547c are detachable from the base portions 546b ₀ , 547b ₀ of the claw bases 546b, 547b as in the present embodiment, the claws, not the entire first and second claws 546, 547, are removed. Only tip portions 546c and 547c can be replaced.

The tip sides of the claw tip portions 546c and 547c are bent so as to approach each other. The ingot 6 can be lifted by the tip side of the claw tip portions 546c and 547c entering the recess 61 provided in the ingot 6. As shown in FIG. Top surfaces of the claw tip portions 546c and 547c on the tip side form contact portions 546d and 547d that come into contact with the ingot 6 when the ingot 6 is lifted.

In gripping portion 54 of the present embodiment, liner 548 (interposition) is inserted between claw base 546b and claw tip 546c in first claw 546 . Therefore, although the claw tip portion 546c of the first claw 546 and the claw tip portion 547c of the second claw 547 have the same shape, the contact portion 546d of the first claw 546 is the contact portion of the second claw 547. It is arranged below 547d.

The gripping portion 54 of the present embodiment is configured to grip the ingot 6 such that the upper surface 62 of the ingot 6 is inclined with respect to the horizontal due to the difference in the height positions of the contact portions 546d and 547d. Since the upper surface 62 of the ingot 6 is inclined with respect to the horizontal, the upper surface 62 of the ingot 6 gradually enters the surface of the molten metal bath 3 when the ingot 6 is introduced into the molten metal bath 3 . Therefore, compared to the case where the entire upper surface 62 of the ingot 6 enters the surface of the molten metal bath 3 at one time, fluctuations in the surface of the molten metal bath 3 when the ingot 6 is charged can be suppressed.

Next, the elevating section 53 of FIG. 1 will be described in more detail with reference to FIGS. 7 and 8. FIG. FIG. 7 is a front view showing in more detail the lifting section 53 of FIG. FIG. 8 is an explanatory diagram showing a state in which the gripping portion 54 is lifted by the lifting portion 53 of FIG.

As shown in FIGS. 7 and 8, the lifting section 53 includes a first link body 531, a second link body 532, a first guide member 533, a second guide member 534, a linear body 535, a plurality of pulleys 536, a winding It has a pick wheel 537 and a motor 538 .

The first and second link bodies 531 and 532 are longitudinal members arranged to cross each other. One end 531 a of the first link body 531 is rotatably connected to the grip portion base 540 of the grip portion 54 . The other end 531 b of the first link body 531 is provided displaceable along a long hole 533 a provided in the first guide member 533 . The first guide member 533 is fixed to the movable body 521 of the second conveying section 52 above the other end 532 b of the second link body 532 . One end 532 a of the second link body 532 is rotatably connected to the movable body 521 of the second conveying section 52 . The other end 532b of the second link body 532 is displaceable along an elongated hole 534a provided in the second guide member 534. As shown in FIG. The second guide member 534 is fixed to the grip portion base body 540 of the grip portion 54 below the other end 531 b of the first link body 531 .

The linear body 535 is composed of, for example, a wire or a chain. One end of the linear body 535 is fixed to the grip portion base body 540 of the grip portion 54 . A linear body 535 is wound around a plurality of pulleys 536 and guided to a winding wheel 537 . A motor 538 is connected to the winding wheel 537 .

The linear body 535 is wound on the winding wheel 537 by rotating the winding wheel 537 in the forward direction (first direction) by the driving force of the motor 538 . By winding the linear body 535 onto the winding wheel 537 , the entire grip portion 54 is raised through the grip portion base 540 . Further, the winding wheel 537 is rotated in the opposite direction (second direction) by the driving force of the motor 538 , so that the linear body 535 is sent out from the winding wheel 537 . As the linear body 535 is sent out from the winding wheel 537, the gripping portion 54 is lowered by its own weight. In the lifting section 53 of the present embodiment, the speed of lifting and lowering of the grip section 54 is controlled by controlling the rotational speed of the motor 538 . As described above, the control unit 57 of this embodiment includes an inverter to control the rotation speed of the motor 538 .

When the grip part 54 is raised and lowered, the other ends 531b and 532b of the first and second link bodies 531 and 532 are displaced along the long holes 533a and 534a of the first and second guide members 533 and 534. . As a result, shaking of the grip portion 54 is suppressed.

The manufacturing method of the hot-dip plated metal strip of the present embodiment is a method of manufacturing the hot-dip plated metal strip 2 by immersing the metal strip 1 in the molten metal bath 3. including throwing an ingot 6 into the .

Examples are given below. The present inventor immersed a steel sheet in a molten Zn--Al--Mg alloy bath to produce a hot-dip plated metal strip 2 having a Zn--Al--Mg alloy plating layer. Further, the ingot 6 was put into the molten Zn--Al--Mg alloy bath at any time to maintain the molten Zn--Al--Mg alloy bath. When the ingot 6 was put into the molten Zn--Al--Mg alloy bath at a descending speed of 3.4 m/min, the quality abnormality of the coating layer of the hot-dip plated metal strip 2 occurred every time the ingot 6 was put into the bath. On the other hand, when the ingot 6 was put into the molten Zn--Al--Mg alloy bath at a lowering speed of 0.54 m/min, the occurrence of quality abnormality could be avoided.

In the ingot charging device 5 and the manufacturing method of the hot-dip-plated metal strip, the control unit 57 controls the lifting position of the gripping unit 54 when the gripping unit 54 is lowered to drop the ingot 6 into the molten metal bath 3. When the deceleration position is reached, the descent of the gripper 54 is decelerated, and the ingot 6 is thrown into the molten metal bath 3 at the decelerated speed. A molten metal bath can be maintained reliably. This configuration is particularly useful when the molten metal bath 3 is a molten Zn--Al--Mg alloy bath.

In addition, since the control unit 57 includes an inverter that controls the electric power supplied to the lifting unit 53, it is possible to decelerate the gripping unit 54 arbitrarily.

Furthermore, since the control unit 57 determines the descending speed of the gripping unit 54 after deceleration based on the command from the input unit 58, the descending speed of the gripping unit 54 can be arbitrarily changed.

Furthermore, since the signal used for control by the control unit 57 can be switched between the signal from the first sensor 55 and the signal from the second sensor 56, either one of the first and second sensors 55 and 56 can Even if a problem occurs, control can be performed by a signal from the other side, and deterioration in the production efficiency of the hot-dip plated metal strip 2 due to a sensor problem can be avoided.

In addition, since the gripping portion 54 is configured to grip the ingot 6 such that the upper surface 62 of the ingot 6 is inclined with respect to the horizontal, the upper surface 62 of the ingot 6 may be tilted when the ingot 6 is introduced into the molten metal bath 3 . can gradually enter the surface of the molten metal bath 3. As a result, compared with the case where the entire upper surface 62 of the ingot 6 enters the surface of the molten metal bath 3 at one time, fluctuations in the surface of the molten metal bath 3 when the ingot 6 is charged can be suppressed.

Furthermore, since the contact portion 546d of the first claw 546 is arranged below the contact portion 547d of the second claw 547, the ingot 6 is more reliably gripped so that the upper surface 62 of the ingot 6 is inclined with respect to the horizontal. can do.

Furthermore, in the first claw 546, since the liner 548 (inclusion) is inserted between the claw base 546b and the claw tip 546c, the claw tip 546c of the first claw 546 and the claw of the second claw 547 are separated from each other. Even if the tip portion 547c has the same shape, the contact portion 546d of the first claw 546 can be arranged below the contact portion 547d of the second claw 547. FIG.

In addition, since the control unit 57 opens and closes the two pairs of claws 541 and 542 a plurality of times after the ingot 6 is immersed in the molten metal bath 3 and before the gripping portion 54 is lifted, the ingot 6 is held by the claws 541 and 542. It is possible to reliably prevent the grip portion 54 from being lifted in a state of being caught.

In the embodiment, the gripping portion 54 has two pairs of claws 541 and 542, but the gripping portion may have a pair of claws or three or more pairs of claws. may

In addition, in the embodiment, a liner 548 (interposition) is inserted between the claw base 546b and the claw tip portion 546c in the first claw 546, so that the contact portion 546d of the first claw 546 is moved to the contact portion 546d of the second claw 547. Although it has been described that it is arranged below the contact portion 547d, the first claw may be made longer than the second claw and the contact portion of the first claw may be arranged below the contact portion of the second claw. .

Furthermore, in the embodiment, by arranging the contact portion 546d of the first claw 546 below the contact portion 547d of the second claw 547, the ingot 6 is moved so that the upper surface 62 of the ingot 6 is inclined with respect to the horizontal. Although it has been described that it is gripped, the ingot may have a shape in which the upper surface extends with an inclination with respect to the horizontal when gripped by the gripping portion.

Furthermore, although the first and second sensors 55 and 56 have been described as measuring different physical quantities, the first and second sensors may measure the same physical quantity.

1 Metal strip 2 Hot-dip plated metal strip 3 Molten metal bath 5 Ingot loading device 53 Elevating unit 54 Gripping units 541, 542 Claws 546b, 547b Claw bases 546c, 547c Claw tips 546d, 547d Contacting part 548 Liner (inclusion)
55 First sensor 56 Second sensor 57 Control unit 58 Input unit 6 Ingot 62 Upper surface.

Claims (9)

An ingot charging device for charging an ingot into a molten metal bath in which a metal strip is immersed,
a gripping portion for gripping the ingot;
an elevating unit for elevating the gripping unit;
a sensor for detecting the lifting position of the gripping part;
a control unit that controls the lifting operation of the lifting unit based on a signal from the sensor ;
an input unit for inputting a command to the control unit;
with
When the gripping portion is lowered to drop the ingot into the molten metal bath, the control portion sets the lifting position of the gripping portion to a predetermined deceleration position before the lower end of the ingot comes into contact with the molten metal bath. slowing down the descent of the gripper when the temperature rises, and throwing the ingot into the molten metal bath at the reduced speed;
The control unit determines a descending speed of the gripping unit after deceleration based on a command from the input unit.
Ingot charging device. The control unit includes an inverter that controls power supplied to the lifting unit,
The ingot charging device according to claim 1. The sensors include a first sensor for detecting the lifting position of the grip by measuring the distance from a reference position to the grip, and measuring the elapsed time from the start of lifting of the grip. and a second sensor for detecting the lifting position of the gripping portion by
A signal used for control by the control unit can be switched between a signal from the first sensor and a signal from the second sensor.
The ingot charging device according to claim 1 or 2 . The gripping part is configured to grip the ingot such that the upper surface of the ingot is inclined with respect to the horizontal.
The ingot charging device according to any one of claims 1 to 3 . The gripping portion includes at least a pair of claws that can be opened and closed, and is configured such that the ingot is gripped by the at least one pair of claws when the at least one pair of claws are closed,
The claw is provided with a contact portion that comes into contact with the ingot when lifting the ingot,
The contact portion of one of the pair of claws is arranged below the contact portion of the other of the pair of claws,
The ingot charging device according to claim 4 . The claw is provided with a claw base and a claw tip attached to the claw base,
In the one, an interposition is inserted between the claw base and the claw tip, so that the contact portion of the one is arranged below the contact portion of the other.
The ingot charging device according to claim 5 . The gripping portion includes at least a pair of claws that can be opened and closed, and is configured such that the ingot is gripped by the at least one pair of claws when the at least one pair of claws are closed,
The control unit opens and closes the at least one pair of claws a plurality of times after the ingot is immersed in the molten metal bath and before the gripping unit is raised.
The ingot charging device according to any one of claims 1 to 6 . The molten metal bath is a molten Zn-Al-Mg alloy bath,
The ingot charging device according to any one of claims 1 to 7 . A method for producing a hot-dip plated metal strip by immersing the metal strip in a molten metal bath, comprising:
A method for producing a hot-dip plated metal strip, comprising charging the ingot into the molten metal bath by the ingot charging device according to any one of claims 1 to 8 .

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