JP2702967B2 - Continuous melting plating apparatus and method - Google Patents

Description

The present invention relates to a continuous melting plating apparatus and a method thereof,
More particularly, the present invention relates to a continuous melting plating apparatus having a gas injection nozzle for blowing a wiping gas to a covering surface of a steel strip, and a method therefor.

[Conventional technology]

As shown in FIG. 10, the continuous melting plating apparatus is a plating bath in which a strip 62 passed through a reducing atmosphere duct 61 is bent downward by a roller 63 and a melting plating agent 65 is pooled.
Entered in 64. The sink roller 66
The sink roller 66 is used for stripping.
62 is raised upward. Then, the excess adhesive 67 attached to the strip 62 is wiped by a gas knife 73 ejected from a nozzle 68, and is controlled to a predetermined thickness.

As described above, since the gas wiping plating thickness control is performed in a non-contact manner, it is advantageous for obtaining a product having good plating quality.

[Problems to be solved by the invention]

However, in recent years, the demand for plating products has been increasing for products in which it is desired to make the plating film as thin as possible from the viewpoint of resource saving.

For this purpose, the gas wiping nozzle 68 shown in FIG.
It is necessary to make the distance δ between the tip of the nozzle 9 and the strip 9 as small as possible so as not to reduce the collision flow velocity of the gas knife ejected from the opening 72 at the nozzle tip against the strip surface.

This is, as seen in Japanese Patent Publication No. 55-48101,
This has been facilitated by installing devices that can correct the curvature of the strip.

Then, by employing the above technique, δ in FIG. 10 can be reduced to about 15 mm, and a sufficiently thin plating can be achieved. However, in such a nozzle close to the strip, nozzle clogging is likely to occur in a part of the nozzle orifice.

That is, since the adhesive is originally easy to adhere, such as zinc or Al, the adhesive is blown off by a high-speed gas knife of 100 to 200 m / sec ejected from the nozzle tip, and the adhesive is often 11th. This is to adhere to the tip of the gas wiping nozzle 68 as shown in the figure and cause nozzle clogging. When the nozzle clogging occurs as described above, a streak pattern is generated on the surface of the plated product, and the product value is lost. Therefore, there is no other way than to cut off the product, causing a significant decrease in yield, which is a problem.

On the other hand, for sudden clogging of the nozzle injection port,
In order not to lower the productivity, for example, Japanese Patent Publication No. 60-5878
As described in Japanese Patent Publication No. 5 (1994), one gas injection nozzle that blows the wiping gas onto the plated surface of the plate-like member from a plurality of injection nozzles can be selected.
During continuous operation, the operator constantly and carefully monitors the sudden clogging of the nozzle orifice portion, and when clogging is found, a part that cannot be regarded as a product. As soon as possible, the selection switching of the gas injection nozzles is required so that is minimized.

However, the above is a considerable amount of hard work for the operator. That is, in a work environment in which high temperature, loud noise and dust are scattered, it is a great task to constantly and carefully monitor the work environment, and improvement of the work environment is desired. In addition, at least one person has to be engaged in this monitoring work, and has been taken up as a major problem in recent years when labor saving is desired.

SUMMARY OF THE INVENTION An object of the present invention is to detect clogging at an outlet of a gas injection nozzle having a narrow gap and a long gap at a high temperature, promptly switch the selection of the gas injection nozzle, and reduce labor without reducing productivity of a plating material. It is an object of the present invention to provide a continuous melting plating apparatus and a method for achieving the same.

[Means for solving the problem]

The object is to provide a gas injection nozzle coupled to one end of a hollow support cylinder that supplies a pressurized wiping gas and extending in the axial direction of the hollow support cylinder that blows the wiping gas onto a surface of a plate-shaped member. A configuration in which at least two gas injection nozzles are provided, and one gas injection nozzle that swirls the gas injection nozzle and blows the wiping gas onto the surface to be covered of the plate-like member from among the plurality of injection nozzles can be selected; Transmission clogging detection that detects clogging at the ejection port of the injection nozzle in order to switch to a non-clogged injection nozzle when the injection nozzle during the wiping operation is clogged This is attained by providing a vessel for each of the plurality of injection nozzles and providing cooling means for cooling the clogging detector.

Further, the above object is to provide a gas injection device which is connected to one end of a hollow support cylinder for supplying a pressurized wiping gas and which extends in the axial direction of the hollow support cylinder for blowing the wiping gas onto a surface of a plate-shaped member to be covered. At least two nozzles can be provided, and one gas injection nozzle that swirls the gas injection nozzle and blows the wiping gas onto the surface of the plate-like member to be attached can be selected from the plurality of injection nozzles. In the continuous melting plating device with the configuration, when the injection nozzle during the wiping operation is clogged,
A clogging detector for detecting clogging of an ejection port of the ejection nozzle using a light emitting device and an image sensor for switching to a clogging ejection nozzle, for each of the plurality of ejection nozzles, and the clogging detector This is achieved by providing a cooling means for cooling.

Further, the above object is attained by attaching at least two gas injection nozzles coupled to one end of a hollow support cylinder for supplying a pressurized wiping gas and extending in the axial direction of the hollow support cylinder to the surface of the plate-like member to be covered. When blowing the wiping gas, the gas injection nozzle is turned to select one gas injection nozzle from the plurality of injection nozzles, and the wiping gas is applied to the surface of the plate-shaped member to be covered. In the continuous melting plating method of spraying
Clogging of the ejection port of the ejection nozzle during the wiping operation is detected by a transmission type clogging detector having a cooling device,
This is achieved by switching to an injection nozzle without clogging.

Further, the object is to provide a molten metal bath for continuously hot-dipping the plate-like member, and wiping excess plating agent adhering to the plate-like member with a jetting gas jet knife to a predetermined plating thickness. A continuous melting plating apparatus having a gas injection nozzle for controlling a laser beam, a transmission type laser generation apparatus for constantly passing a laser beam through a gas ejection opening of the gas injection nozzle, and a cooling means for cooling the laser generation apparatus This is achieved by having

As means for heating and melting, a heating light beam such as a laser beam is always passed through the gas ejection opening of the gas injection nozzle, or the tip member of the gas injection nozzle is heated, and an adhesive is applied to this portion. Even if it arrives and clogging is likely to occur, it is melted or heated to prevent the solidifying agent from cooling and solidifying at the nozzle tip. It is blown off by a gas knife.

[Action]

The clogging detector at the nozzle outlet of the nozzle attached to the injection nozzle detects sudden clogging during continuous plating operation, and accordingly, detects the clogging at one end of the hollow support cylinder that supplies pressurized wiping gas. A nozzle header provided with at least two or more gas injection nozzles that are joined and extend in the axial direction of the hollow support cylinder that blows the wiping gas onto the covering surface of the plate member,
It turns and switches to a nozzle without clogging, so there is no need for constant monitoring by the operator, and even if clogging occurs,
Since it can operate so as to minimize a part that cannot be made into a product, it is possible to save labor without reducing productivity.

In addition, the nozzle clogging detector is a slit gap that is extremely small, 0.5 to 2.0 mm, and detects at high temperatures exceeding 100 ° C and in an atmosphere in which plated metal splash is scattered. The above technology is achieved by selecting and using a beam switch that satisfies the following among many beam switches for use.

1) A thin and strong light beam that can be detected in a slit with a gap of 0.5 to 2.0 mm and a length of 1000 to 2000 mm.

2) It shall have cooling means such as air cooling and water cooling, and be capable of withstanding high temperatures exceeding 100 ° C.

3) In an atmosphere where splashed metal splash is scattered, strong light rays should not be erroneously detected.

In other words, by making the clogging detector a transmission type, it is possible to detect clogging at the narrow and long injection nozzle ejection port. Further, since the clogging detector is provided with a cooling means, the clogging detector can withstand a high temperature exceeding 100 ° C. without failure, thereby enabling the clogging detection during the continuous plating operation.

Further, as described above, the adhesive agent that causes the nozzle tip ejection hole to be clogged is in a molten state at the time when it adheres to the strip. However, a part thereof is repelled by the gas knife from the strip surface, reaches the tip of the nozzle, and adheres to the opening of the coagulation nozzle to cause clogging.

At that time, heating energy is immediately applied to the adhesive which reaches the tip of the gas nozzle, so that the adhesive does not solidify and cause clogging of the nozzle tip opening.

That is, assuming that the plating agent reaching the nozzle opening portion has just been cooled to the extent that the latent heat of fusion has been deprived, that is, if it has been cooled in a semi-solid state, the following heating energy is required to completely cool it. is necessary.

That is, although the gap of the slit at the opening of the nozzle is about 1 mm, a volume of about 1 mm ³ is usually clogged here.

In order to melt this, heat of fusion may be given, but in the case of typical zinc, an electric power of about 70 watts is required to melt in a short time such as 0.01 sec. Therefore, if this level of heating energy is always provided, even if the plating agent adheres to the tip of the nozzle, it is immediately melted, or can be blown off by the gas wiping flow without progress of cooling and solidification. No nozzle clogging occurs.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the embodiment shown in FIG. 1 and FIG.

FIG. 1 is a plan view of the continuous melting plating apparatus of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, in which wiping gas is blown from both sides to a strip 9 such as a steel strip. A pair consisting of a left and a right pair is shown so as to be able to perform. First
In the drawing, reference numeral 1 denotes a liquid bath for melting and plating, and 2 denotes a nozzle header for supplying pressurized wiping gas to a gas injection nozzle 3 and is connected to one end of a hollow support cylinder 4. That is, pressurized wiping gas is supplied from the direction of the arrow in the figure, passes through the hollow support cylinder 4, flows into the nozzle head 2, and is supplied to the gas injection nozzle 3.

Incidentally, the nozzle header 2 is configured as shown in FIG.

As shown in the figure, each of the nozzle headers 2 is provided with two gas injection nozzles 3, the gas injection nozzle 3 in operation suddenly clogs the injection port, and the gas injection nozzle 3 If it becomes necessary to replace the nozzle, rotate the hollow support cylinder 4 connected to the nozzle header 2 by 180 °,
The wiping can be restarted by using the gas injection nozzle 3 on the opposite side.

Reference numeral 5 denotes a detector for detecting clogging at a nozzle opening of a nozzle which is an element part of the present invention. It is mounted on the hollow support cylinder 4 on both sides of the nozzle header 2. In this embodiment, a light transmission type (a type in which light from a projector to a photodetector is detected by blocking light from an object) used for general steel equipment is shown. As shown in FIG. 2, the periphery of the gas injection nozzle 3 is covered with a metal splash 6 at a high temperature exceeding 100 ° C.
In the atmosphere where is scattered, when there is no clogging of the nozzle, there is a powerful light beam that will not be blocked by splash or dust, and an infrared semiconductor laser type detector with air cooling or water cooling was selected. . The transmitted light 7 of the clogging detector 5 passes through the inside of the gas ejection port 8 in parallel, and when the gas ejection port 8 is clogged by the splash 6 or the like, it is shielded and detected. .

That is, during continuous operation, when the gas injection nozzle suddenly clogs the spout 8 with the splash 6, the clogging detector 5 detects the clogging and detects the hollow support cylinder 4 connected with the nozzle header 2 by 180 degrees.゜ By rotating, the wiping is restarted by using the gas injection nozzle 3 on the opposite side.

According to the above-described embodiment of the present invention, unlike the related art, there is no need for the operator to constantly monitor with utmost care, and even if clogging occurs, a part that cannot be formed as a product is eliminated. The selection of the gas injection nozzle can be promptly switched so as to minimize it.

Therefore, it is possible to save labor without reducing productivity. In addition, the operator himself can avoid the heavy labor of constantly monitoring in a bad environment.

In the above-described embodiment, two gas injection nozzles 3 are provided. However, the number of gas injection nozzles 3 may be one if only simple monitoring by an operator is to be avoided. In order to cope with the problem described above, the number may be two or more.

Further, an embodiment as an operation method is shown in FIG. 3 and FIG. FIG. 3 is an example of a semi-automatic operation in which an operator's judgment is interposed in the middle. When repairs can be made with hand tools, etc., the gas injection nozzles are not switched, so the parts that cannot be made can be minimized, but every time clogging occurs, an operator's call (by alarm etc.) is required. It can also be used as an operation for other equipment, and can save labor on the entire equipment.

FIG. 4 shows a fully automatic operation example. Even if the clogging can be repaired with a hand tool due to slight clogging, the productivity is reduced as compared with FIG. 3 because the nozzle is turned to perform switching, but in terms of labor saving, The effect is great.

In the above-described embodiment, the case where the transmission type infrared semiconductor laser type detector is used is shown. However, the configuration is made of a heat-resistant type light projector and an image sensor, and when a foreign substance having a specific size or more is detected, clogging is performed. If the nozzle is switched to a nozzle having no nozzle, it is possible to perform adjustment so as to enable detection that is most suitable during operation and prevent erroneous detection.

Further, it is also possible to detect clogging and switch to a nozzle without clogging at a set specific timing, thereby achieving complete automation. in this case,
In consideration of improving the yield, the timing at which the welded joint of the steel strip passes is good.

Next, an example in which another embodiment of the present invention is applied to the nozzle wiping nozzle system shown in FIG. 10 will be described with reference to FIGS.

Fig. 5 shows the gas injection nozzle tip with SiC, NiGr
The heating element 22 is made of steel or SUS material. Electric energy is supplied from the power supply 24 to the terminals 23 at both ends of the heating element 22 through the conducting wire 50, and the heating element 22 is always heated to a temperature about the melting point of the plating agent. . Heating element 22 at the nozzle tip in typical zinc plating
Is heated to a temperature around 420 ° C.

Note that a heat insulating material 31 is inserted between the nozzle tip heating element 22 and the gas ejection header 21 so as to prevent heat transfer.
In addition, gas is injected from the nozzle into the gas injection header 21 through the conduit 11, and is injected from the mixing pipe 10 into the strip 9 from the narrow slit nozzle formed by the two nozzle tip heating elements.

FIG. 6 shows the heating element 32 at the tip of the ejection nozzle shown in FIG.
To reduce loss of radiant heat from the surface of the heating element. In this case, the heat insulating layer 52 is bent as shown in the figure.

FIG. 7 shows a method for melting nozzle clogging by a laser beam.

As is well known, the laser beam gives energy from a power source 14 to a gas such as carbon dioxide gas supplied by a pump 17 between a concave mirror 16 and a plane mirror 15, and emits electron energy in the form of a beam 18 through the vibration of molecules.

In FIG. 7, a beam nozzle provided with a slit hole 20 as shown in FIG.
This gas is always supplied along the longitudinal direction of the slit ejection hole 12 of the gas wiping nozzle shown in the cross section AA in FIG. For this purpose, a transparent glass 35 or the like is incorporated into the side wall of the mixing tube 10 in the header 68 so that the beam can pass therethrough.

The gas nozzle header 68 on the opposite side is irradiated with the laser beam 20 from the right side in FIG.

In the nozzle of FIG. 9, a hole 42 is provided in a member 40 at the nozzle tip, a high-temperature gas is flowed through the hole 42, and the nozzle tip member is heated, thereby preventing nozzle clogging. .

Also in this case, the heat insulating agent 70 is inserted between the nozzle tip member 40 and the header 41.

In the example shown in FIG. 9, the nozzle tip member is heated with the high-temperature gas from the inside, but it is needless to say that the high-temperature gas may be blown from the outside of the nozzle to heat the nozzle.

Further, the nozzle tip member in FIG. 9 may be heated by induction heating.

In any case, in the examples shown in FIGS. 5, 6, and 9, the tip of the nozzle is heated to prevent the plating agent from solidifying and adhering to the nozzle. In these cases, the heating temperature of the nozzle tip member does not necessarily have to be heated to the melting point of the plating agent, and even if it is lower than that, the heating agent reaches the nozzle tip and the adhesive further solidifies and lowers the temperature significantly. It has been found that any device that can prevent the above problem can be used. However, it was confirmed through many experiments that heating to a temperature of about 1/3 or more of the melting point of the plating agent was advantageous in preventing nozzle clogging.

From the above points, in the nozzle tip heating method as shown in FIGS. 5, 6, and 9, for example, as shown in FIG. 5, the temperature at the tip of the nozzle is measured by a thermometer 80. In advance, a command is issued from the control panel 81 based on the measured value, and the heating energy supplied to the nozzle tip heating element 22 is controlled so as to maintain the temperature of the nozzle tip at a predetermined value. It is advantageous from.

〔The invention's effect〕

As described above, according to the present invention, since the transmission type clogging detector is provided with the cooling means, it is possible to apply the nozzle clogging detector at a nozzle outlet having a high temperature and a narrow and long gap. Unlike the past, there is no need to perform heavy labor of constantly monitoring operators in a bad environment.
In addition, since the selection of the gas injection nozzle can be promptly switched so as to minimize the part that cannot be formed as a product, there is an effect that labor can be saved without lowering the productivity of the plated material.

[Brief description of the drawings]

FIG. 1 is a plan view of one embodiment of the continuous melting plating apparatus of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIGS. FIG. 5 is a perspective view showing another embodiment of the present invention, FIG. 6 is a sectional view showing another embodiment of the nozzle tip in the apparatus shown in FIG. 1, and FIG. 7 is heating. FIG. 8 is a diagram showing an example of a laser beam slit passage method nozzle, FIG. 9 is a cross-sectional view of a nozzle portion showing an example of high-temperature gas heating, and FIG. 10 is a general continuous melting method. FIG. 11 is a sectional view showing a plating apparatus, and FIG. 11 is a sectional view showing a conventional nozzle employed therein. 2 ... Nozzle header, 3 ... Gas injection nozzle, 4 ... Hollow support cylinder, 5 ... Clogging detector, 7 ... Transmitted light, 8 ...
Gas vent, 9 ... strip, 11 ... conduit, 18, 20 ...
… Beam, 21… Head spouting gas, 22 …… Heating element.

Continuation of the front page (72) Inventor Teruo Yamaguchi 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (56) References Open-ended Showa 54-133129 (JP, U) Open-ended Showa 63 -177953 (JP, U) Jpn.

Claims (15)

(57) [Claims] 1. A gas injection nozzle connected to one end of a hollow support cylinder for supplying a pressurized wiping gas and extending in an axial direction of the hollow support cylinder for blowing the wiping gas onto a surface of a plate-shaped member to be covered. A configuration wherein at least two gas injection nozzles for rotating the gas injection nozzle and spraying the wiping gas onto the surface to be covered of the plate-shaped member can be selected from the plurality of injection nozzles. Transmission clogging that detects clogging at the ejection port of an injection nozzle in order to switch to a non-clogged injection nozzle when the injection nozzle is clogged during the wiping operation in the continuous melting plating device A continuous melting plating apparatus, wherein a detector is provided for each of the plurality of injection nozzles, and cooling means for cooling the clogging detector is provided. 2. The continuous hot-dip plating apparatus according to claim 1, wherein said clogging detector uses an infrared semiconductor laser. 3. A gas injection nozzle coupled to one end of a hollow support cylinder for supplying a pressurized wiping gas and extending in the axial direction of the hollow support cylinder for blowing the wiping gas onto a surface of a plate-like member to be covered. A configuration wherein at least two gas injection nozzles for rotating the gas injection nozzle and spraying the wiping gas onto the surface to be covered of the plate-shaped member can be selected from the plurality of injection nozzles. In the continuous melting plating device, when the injection nozzle during the wiping operation is clogged, the clogging of the ejection port of the injection nozzle is performed using a light emitter and an image sensor in order to switch to a non-clogged injection nozzle. A continuous melting plating apparatus, wherein a clogging detector for detection is provided for each of the plurality of injection nozzles, and cooling means for cooling the clogging detector is provided. 4. A blow-off surface which is connected to one end of a hollow support cylinder for supplying a pressurized wiping gas and which is blown onto the surface of the plate-like member by at least two gas injection nozzles extending in the axial direction of the hollow support cylinder. When spraying the wiping gas, the gas injection nozzle is swirled to select one gas injection nozzle from the plurality of injection nozzles, and the wiping gas is applied to the covering surface of the plate-shaped member. In the continuous melting plating method, the clogging of the jet nozzle of the jet nozzle during the wiping operation is detected by a transmission type clogging detector equipped with a cooling device, and the jet nozzle is switched to a jet nozzle without clogging. A continuous melting plating method characterized in that: 5. The continuous melting plating method according to claim 4, wherein the switching to the injection nozzle having no clogging after detecting the clogging is performed at a set specific timing. 6. The continuous melting plating method according to claim 5, wherein the set specific timing is a timing at which a welding point of the plate member passes before and after the gas injection nozzle. 7. After continuously hot-dipping the plate-like member in a bath for applying a molten metal, an excess adhesive agent adhering to the plate-like member is wiped by a gas jet knife ejected from a gas injection nozzle. A continuous melting plating method for controlling to a predetermined plating thickness, wherein a heating agent is applied to heat or melt a plating agent attached to a tip ejection hole of the gas injection nozzle. Item 6. The continuous melting plating method according to Item 4. 8. The continuous melting plating method according to claim 4, wherein a heating beam is passed through a gas ejection hole at the tip of the gas injection nozzle to melt a plating agent attached to the tip of the injection nozzle. 9. The gas jet nozzle tip member of the gas jet nozzle is heated by externally applying heating energy to heat or melt the adhesive agent attached to the jet nozzle tip. Item 6. The continuous melting plating method according to Item 4. 10. The gas injection nozzle according to claim 9, wherein the tip of the gas injection nozzle is formed of a heating element, and the heating element is supplied with electric energy for heating to melt the adhesive attached to the gas injection nozzle. Continuous melting plating method. 11. The continuous melting plating according to claim 9, wherein the tip of said gas injection nozzle is heated internally or externally using a high-temperature gas to melt a plating agent attached to the gas injection nozzle. Method. 12. A tub for continuously hot-dipping a plate-like member, and an excess plating agent adhering to said plate-like member being wiped by a jet gas jet knife to a predetermined thickness. A continuous melting plating apparatus provided with a gas injection nozzle to be controlled, characterized in that a tip of the gas injection nozzle is constituted by a heating element, and a power supply is provided for supplying electric energy to the heating element to heat the heating element. The continuous melting plating apparatus according to claim 1 or 3, wherein: 13. The continuous melting plating apparatus according to claim 12, wherein a heat insulating material is provided between the heating element and the gas ejection header. 14. A molten metal plating tank for continuously hot-dipping a plate-like member, and an excess plating agent adhering to said plate-like member is wiped by a gas jet knife to jet to a predetermined plating thickness. In a continuous melting plating apparatus having a gas injection nozzle to be controlled, a transmission type laser generator for constantly passing a laser beam through a gas ejection opening of the gas injection nozzle, and a cooling unit for cooling the laser generator are provided. A continuous melting plating apparatus, comprising: 15. A bath in which a plate-like member is continuously hot-deposited, and an excess plating agent adhering to said plate-like member is wiped by a jet gas jet knife to a predetermined plating thickness. A continuous melting plating apparatus having a gas injection nozzle to be controlled, wherein a flow hole through which a high-temperature gas body for heating the nozzle tip member is provided at a tip of the gas injection nozzle. The continuous melting plating apparatus according to claim 1.