JP6350274B2 - Lubricating oil supply equipment for cold rolling mills - Google Patents

Description

  The present invention relates to a lubricating oil supply facility used when rolling a metal plate such as a thin steel strip, and in particular, a lubricating oil supply facility used in a gas atomized lubricating oil supply method performed in a cold rolling process. A plurality of nozzles are arranged in the plate width direction of the material to be rolled, and for each nozzle, each nozzle is arranged in the middle of a pipe that feeds lubricating oil to the plurality of nozzles by a pump device smaller than the number of nozzles. The present invention relates to a lubricating oil supply facility provided with a hollow structure distributing device for distributing lubricating oil.

  As is well known, in a cold rolling process for a sheet steel strip or the like, rolling is performed while lubricating between a sheet steel strip as a material to be rolled and a roll of a cold rolling mill. Lubricating oil is supplied by stirring and mixing the lubricating oil in the lubricating oil tank so that the lubricating oil concentration is about 1 to 5% by volume with respect to water. Supplying to the roll, collecting emulsion under the rolling mill and returning it to the tank (Non-patent Document 1), or supplying the lubricant stock solution with gas to the roll and steel plate with a two-fluid nozzle A gas atomized lubricating oil supply method (Patent Document 1) is known.

  Since the circulating emulsion lubricant supply method enables reuse of the lubricant, the lubricant cost is low, and the supply of the emulsion can also serve as roll cooling. Widely used as an oil supply method.

  On the other hand, the gas atomized lubricating oil supply method is a method in which a small amount of lubricating oil is atomized together with gas using a two-fluid nozzle and sprayed onto a roll or a steel plate. It is known that a lubricating effect equal to or higher than that can be exhibited with a significantly smaller amount of lubricating oil supplied.

  When the gas atomized lubricant supply method is applied to cold rolling of a thin steel strip, it is necessary to simultaneously pump an equal amount of lubricant to a plurality of nozzles arranged side by side in the plate width direction. As a means of this, by distributing a hollow distribution device in the middle of a pipe that feeds lubricating oil to a plurality of nozzles by a single lubricating oil pump device, a substantially equal amount of lubricating oil is distributed to the plurality of nozzles. The technique to do is disclosed (patent document 2).

  By the way, as a lubricating oil used for a cold rolling lubricating oil, a lubricating oil having a property of solidifying at room temperature may be used. When using such lubricating oil, if rolling is stopped for a long time during regular repairs in rolling operations, and the supply of lubricating oil is stopped for a long time, the temperature of the lubricating oil in the piping will decrease. Further, the lubricating oil is solidified in the lubricating oil piping, the distribution device, etc., and therefore, there is a possibility that the lubricating oil cannot be smoothly supplied during the rolling operation after the completion of the periodic repair. In order to avoid such a trouble, it is disclosed in Patent Document 2 that a switching valve capable of constantly circulating lubricating oil between the outlet portion of the distributor and the nozzle is provided. In the technique of this patent document 2, when the lubricating oil cannot be injected from the nozzle, the lubricating oil is constantly circulated between the tank and the distributor so that the temperature of the lubricating oil in the pipe does not decrease, and the lubricating oil is supplied. When doing so, the lubricating oil is pumped to the nozzle side to inject the lubricating oil.

  Further, in Patent Document 3, in the gas atomized lubricating oil supply method having one nozzle, in order to be able to supply / turn on / off the lubricating oil from the nozzle with high responsiveness to the lubricating oil ON / OFF operation, Install the lubricating oil supply ON / OFF switch mechanism lower than the position to make it easier to keep the pipe filled with lubricating oil, and start injecting lubricating oil from the nozzle without much delay from the switch operation timing. It is disclosed that it is possible.

JP 2003-094104 A JP 2012-218051 A JP 2009-226478 A

"Theory and Practice of Sheet Rolling (Revised Version)" Japan Steel Association, published on September 30, 2010, p208

  In cold rolling of a metal plate such as a thin steel strip, a plurality of nozzles are installed side by side in the plate width direction, and it is necessary to turn ON / OFF the injection of lubricating oil from these nozzles almost simultaneously. When using a gas atomized lubricating oil supply device equipped with a distribution device in the middle of the piping as a lubricating oil supply method, for example, by operating the ON / OFF mechanism of the pump device or by a valve installed between the pump device and the distribution device When the ON / OFF operation is performed to turn ON / OFF the lubricating oil that is pumped to the distribution device, and ON / OFF the injection of the lubricating oil from the nozzle, the injection of the lubricating oil is started for each nozzle. The timing at which the injection is stopped or the timing at which the injection is stopped is large, and a portion where the lubricating oil is supplied and a portion where the lubricant is not supplied are generated in the plate width direction. If there is a portion that is not supplied with lubrication in the width direction of the plate, product wrinkles or squeezes may occur in those portions, resulting in a significant reduction in the surface quality of the product, and wrinkles on the work roll. Transcription and temporary work roll reassignment are required, leading to a significant reduction in productivity.

  Furthermore, if the supply of lubricating oil is stopped for a long time, if a lubricating oil that solidifies at room temperature is used, the lubricating oil will solidify in the piping and distribution device, and after the supply stops, the next supply of lubricating oil When restarting, the lubricant may not be smoothly injected. In order to suppress solidification of the lubricating oil, a switching valve is provided in the middle of the nozzle piping from the distributor, and when the lubricating oil is not injected from the nozzle, the lubricating oil is circulated between the tank, the pump, and the distributor. Although the technology is disclosed in Patent Document 2, in this means, the lubricating oil remains in the piping between the switching valve between the distributor and the nozzle and the nozzle, and the lubricating oil remains in this portion. After solidifying, the next injection of lubricating oil is not smooth.

The problems when the lubricating oil is supplied to the plurality of nozzles in the plate width direction by the conventional gas atomized lubricating oil supply method as described above are summarized as follows.
That is, there is a large variation in the time from when the lubricating oil is turned on for each nozzle to when the lubricating oil is actually started to be injected. There are places where the lubricating oil is supplied and not supplied in the plate width direction. Where it was not supplied, product defects such as seizure defects were generated, leading to the need for temporary replacement of work rolls. In addition, when the supply of the lubricating oil is stopped for a long time, the lubricating oil is solidified in the pipe, causing the pipe to be clogged, and smooth lubrication may not be possible.

  The present invention was made against the background of the above circumstances, in a lubricating oil supply facility of a cold rolling mill by gas atomization lubrication provided with a distributing device, distributing lubricating oil to a plurality of nozzles with a distributing device and pumping it, Start the supply of lubricant so that the occurrence of fluctuations in the discharge timing of the lubricant injected from each nozzle at the time of ON / OFF of the lubricant can be suppressed, and the occurrence of wrinkles or squeezing due to the variation in the discharge timing can be suppressed. It is possible to stop the supply, and when lubricating oil that is easy to solidify is used, even if the lubrication supply is stopped for a long time and the temperature in the piping decreases, the lubricating oil solidifies and causes nozzle clogging. It is an object to provide a lubricating oil supply facility that does not exist.

  In order to solve the above-mentioned problems, the present inventors have conducted various experiments and studies. As a result, from a plurality of nozzles installed in the plate width direction, the lubricating oil has a good timing according to the lubricating oil ON / OFF operation. It has been newly found that the cause of the start or stop of injection is caused by the following phenomenon.

  That is, the lubricating oil in the pipe continues to drip from the nozzle even after the lubricating oil supply OFF operation, and the amount of the dripping lubricating oil is not the same for each nozzle, so when the lubricating oil supply is turned ON next time The amount of lubricating oil remaining in the pipe between the distributor and the nozzle varies from nozzle to nozzle. As a result, not only does it take time for the lubricating oil to actually start being injected from the nozzle after the lubricating oil supply is turned on, but due to the variation in the lubricating oil remaining in the piping of each nozzle, the actual lubrication from the nozzle There is also a variation in the time when oil starts to be injected.

  From such knowledge, if the amount of lubricant dripping from each nozzle after supply stop can be suppressed within a certain range, it is considered that there is almost no variation at the start or stop of injection, and uneven lubricant supply in the plate width direction is eliminated. As a result of further experiments and examinations in order to find an appropriate condition for the amount of lubricating oil dripping from each nozzle to be the same small amount, the present invention has been made.

When the upper surface of the metal sheet to be rolled or the upper roll surface of the rolling mill is lubricated by gas atomization lubrication, it is usual to provide a nozzle so that the lubricant injection direction is downward from the horizontal direction, Conversely, when the lower surface of the metal sheet to be rolled or the lower roll surface of the rolling mill is lubricated by gas atomized lubrication, it is usual to provide a nozzle so that the lubricating oil injection direction is upward from the horizontal direction. . Appropriate conditions differ slightly depending on whether the lubricant injection direction is downward or upward than the horizontal direction. Therefore, in the present specification, the lubricating oil supply device on the upper surface side of the metal sheet to be rolled or the upper roll surface of the rolling mill is lubricated by gas atomized lubrication, the lubricating oil supply device for the upper side, and the lower surface of the metal sheet to be rolled The lubricating oil supply device for lubricating the side or the lower roll surface of the rolling mill by gas atomization lubrication will be referred to as a lower lubricating oil supply device, and in the first aspect, the conditions of the upper lubricating oil supply device In the second aspect, in addition to the conditions of the upper lubricating oil supply device of the first aspect, the conditions of the lower lubricating oil supply device are defined.
Each aspect of the present invention will be described below.

[First Aspect: Aspect-Defining Aspect of Upper Lubricating Oil Supply Device]
The lubricating oil supply facility for the cold rolling mill according to the first aspect of the present invention comprises:
An upper lubricating oil supply device for lubricating the upper surface side of the metal sheet to be rolled and / or the upper roll surface of the rolling mill by gas atomization lubrication;
A lower lubricating oil supply device for lubricating the lower surface side of the metal sheet to be rolled and / or the lower roll surface of the rolling mill by gas atomized lubrication,
The upper lubricating oil supply device is
A group of nozzles in which a plurality of nozzles for gas atomization lubrication in which the lubricant injection direction is set downward from the horizontal direction are arranged in the plate width direction of the metal sheet to be rolled;
A pump device for pumping the lubricant stock solution toward the nozzles;
A distribution device that distributes the lubricating oil pumped from the pump device to the nozzles;
A plurality of piping portions connecting between the outlet portions of the distributor and the inlet side connection ports of the nozzles;
With
In the distribution device, each outlet portion that sends out the lubricating oil toward each nozzle through each piping portion is provided at the highest position of the lubricating oil flow path in the distribution device,
Each piping part is disposed so that the position of the highest position in the vertical direction in the piping part is located above each outlet part of the distributor,
The average channel cross-sectional area S (cm ² ) in the pipe portion satisfies the following formula (1), and the lubricating oil supply amount Q (cc / min) per nozzle satisfies the following formula (2). The pipe length L (cm) from the highest point in the vertical direction to the inlet connection port of each nozzle in each pipe part is configured to satisfy the following expression (3). To do.
S ≦ 2 (1)
5 ≦ Q ≦ 200 (2)
L ≦ Q / (6 × S) (3)

  In the following description, the lubricating oil stock solution that is pumped from the pump device to the respective nozzles of the nozzle group through the distributor and each piping portion may be simply referred to as “lubricating oil”.

[Effects of First Mode, Positional Relationship and Mechanism in Upper Lubricating Oil Supply Device]
The lubricating oil supply nozzle installed on the upper side of the metal plate to be rolled such as a thin steel strip in the upper lubricating oil supply apparatus is installed so as to inject downward from the horizontal direction in the same manner as a general one. ing. Accordingly, one or more of the upper work roll, intermediate roll, and backup roll of the rolling mill (herein, these are collectively referred to as the upper roll), and / or the entry side of the rolling mill. Cold rolling is performed while supplying lubricating oil to the upper surface of a metal plate to be rolled such as a thin steel plate.
In this way, when the nozzle is installed downward, if the pipe connected to the nozzle is at a position higher than the nozzle, even if the lubricating oil supply OFF operation is performed, the pipe in the pipe at a position higher than the nozzle Lubricating oil tends to drip from the nozzle. The longer the length of the pipe portion that is higher than the nozzle in the pipe from the distributor to the nozzle, the greater the amount of lubricating oil that drips after the lubrication supply OFF operation. If a pressure-resistant hose that is easy to handle is used as the piping between the nozzle and the distributor, the hose connected between the nozzle and the distributor in each nozzle is built into a narrow rolling facility. However, the length of the hose existing at a high position varies greatly from nozzle to nozzle. For this reason, the timing at which the injection of the lubricating oil from each nozzle stops in response to the lubricant supply OFF operation changes, and there is a portion where the lubricating oil is not supplied in the plate width direction, causing problems such as product defects. .

[Average cross-sectional area of the inner diameter of the pipe in the first aspect]
If the average cross-sectional area of the inner diameter of the pipe in the upper lubricating oil supply device is larger than 2 cm ² , the lubricating oil can flow while filling the pipe with the lubricating oil even with the lubricating oil supply amount specified in the first aspect. It becomes difficult, and it becomes difficult to inject the lubricating oil from the nozzle with the lubricating oil supply amount as set. Furthermore, since the lubricating oil cannot be filled in the piping as described above, the lubricating oil injection start timing from the nozzle cannot be made the same, and a stable lubricating oil injection state cannot be obtained. Therefore, in the first aspect, the average cross-sectional area S of the inner diameter of the pipe is defined as 2 cm ² or less as shown in the equation (1). The average cross-sectional area of the inner diameter of this pipe is preferably 1 cm ² or less.

[Range of lubricating oil supply amount in the first embodiment]
When the average cross-sectional area of the inner diameter of the pipe is 2 cm ² or less, the supply amount of the lubricating oil in the upper lubricating oil supply device needs to be in the range of 5 cc / min or more and 200 cc / min or less per nozzle. . If the supply amount of the lubricating oil is less than 5 cc per minute, the lubricating oil does not flow while filling the pipe, and it becomes difficult to inject the lubricating oil from the nozzle with the set lubricating oil supply amount. On the other hand, if the supply amount of lubricating oil is more than 200 cc per minute, the pressure loss in the pipe will increase, a pump device having a large supply capacity will be required, the equipment cost will be high, and the pipe strength will be high Therefore, it becomes difficult to install a lubricating oil supply facility that satisfies the requirements of the present invention in a narrow rolling facility. Therefore, the lubricating oil supply amount Q per nozzle is defined to be in the range of 5 cc / min or more and 200 cc / min or less as shown in the equation (2). In order to set the supply amount of lubricating oil, for example, a pump device having a flow rate adjusting function is used, or a flow meter is installed on the outlet side of the pump device, and measurement is performed with the flow meter. What is necessary is just to set it as the structure which controls a pump apparatus so that supply_amount | feed_rate becomes the target set value.

[General positional relationship and piping length of each part in the first aspect]
In the first aspect, for the upper lubricating oil supply device, the range of the average cross-sectional area S of the inner diameter of the piping and the range of the lubricating oil supply amount Q is limited as described above, and the positional relationship (height of each part in the vertical direction) The length L of the specific part as described above in the pipe part is appropriately regulated according to the average channel cross-sectional area S and the lubricating oil supply amount Q in the pipe part. By doing so, it was found that the above-mentioned phenomenon can be avoided.
That is, first, in the distribution device, it is necessary to provide each outlet portion for sending out the lubricating oil toward each nozzle through each piping portion at the highest position of the lubricating oil flow path in the distribution device. As a result, the lubricating oil passage in the distribution device can be always filled with the lubricating oil.
Second, the pipe portion is disposed so that the highest position in the vertical direction is located above each outlet portion of the distributor, in other words, the nozzle and the distributor are connected. It is necessary to set the maximum height in the middle of the piping to be higher than the height of the outlet portion of the distributor. Thereby, the inside of the pipe from the outlet portion of the distributor to the highest position in the vertical direction (the highest height) in the pipe portion can be always filled with the lubricating oil.
Thirdly, the length L from the place of the highest position in the vertical direction (the place of the maximum height) in the piping part to the inlet connection port of the nozzle shall be a range defined by the expression (3). is necessary. That is, if the length L is regulated within the range regulated by the expression (3) after satisfying the above-mentioned conditions, the highest position in the pipe, particularly in the vertical direction (maximum height) Even if there is a part that is not filled with lubricating oil in the pipe from the point to the inlet connection port of the nozzle, lubrication is performed at almost the same timing from each nozzle of the nozzle group when the lubricating oil supply is ON. It is possible to start supplying oil, and as a result, it is possible to suppress the occurrence of uneven supply of the lubricating oil in the plate width direction.

[Significance of Formula (3) in First Embodiment]
In the rolling operation, the operation of turning on the lubricating oil is usually performed at the start of rolling after periodic repair or when changing rolling conditions such as rolling speed. Setting conditions at the start of rolling and changing the rolling conditions are generally completed within 10 seconds, and if completed within 10 seconds, there is almost no hindrance to productivity. Therefore, it can be said that there is no problem in actual operation if the variation in the amount of lubricant supplied when the lubricant is ON is also eliminated within 10 seconds. In other words, in the upper lubricating oil supply device, the length of the region where the lubricating oil in the piping may drop out of the total length of each piping portion from each outlet portion of the distribution device to the inlet connection port of each nozzle. However, if the lubrication oil flow is less than the pipe length in 10 seconds during lubrication with a steady lubrication oil supply amount, variations in the lubrication oil supply amount when the lubrication oil is ON can be suppressed within approximately 10 seconds. it can.

Here, assuming that the inside of the pipe is filled with the lubricating oil, the distance (pipe length) in which the lubricating oil flows in the pipe during a certain time T (minute) is set to L0 (cm). The relationship between T (min) and distance (pipe length) L0 is as follows using the average cross-sectional area S (cm ² ) in the pipe and the lubricating oil supply amount (cc / min) per nozzle. It is expressed by equation (4).
T = (L0 × S) / Q (4)
If this equation (4) is modified, the following equation (5) is obtained.
L0 = (Q / S) × T (5)
In this equation (5), if the time T is 10 seconds, that is, (1/6) minutes, the length L0 ′ in this case is expressed by the following equations (6) and (7). .
L0 ′ = (Q / S) × (1/6) (6)
That is,
L0 ′ = Q / (6 × S) (7)

By the way, the above-mentioned “region in which the lubricating oil in the piping may sag” of the total length of the piping portion is from the highest point in the vertical direction (the maximum height) as is clear from the above description. It is a piping part to the entrance side connection port of each nozzle. Therefore, the length L (cm) of the piping part from the highest part (maximum height part) in the up-down direction to the inlet side connection port of each nozzle in the total length of the piping part is obtained by Expression (7) If it is L0 ′ or less, dripping of the lubricating oil from the piping portion when the lubricating oil supply is ON can be generally avoided. That is, L0 ′ obtained by the expression (7) corresponding to the condition of 10 seconds is the length of the pipe portion from the highest position in the vertical direction (maximum height position) to the inlet connection port of each nozzle. It can be said that this is the maximum allowable limit length for the length L.
That is,
L ≦ L0 ′ (8)
Therefore, equation (3) can be derived.
L ≦ Q / (6 × S) (3)

In this way, the length L (cm) of the piping part from the highest part in the vertical direction (maximum height part) to the inlet connection port of each nozzle in the total length of the piping part is calculated as the average break in the pipe. Lubricating oil from the piping portion when the lubricating oil supply is turned ON by setting so as to satisfy the expression (3) according to the area S (cm ² ) and the lubricating oil supply amount Q (cc / min) per nozzle. In general, dripping can be avoided. However, as already described, the average flow path cross-sectional area S (cm ² ) in the pipe portion is the expression (1) S ≦ 2 (1)
And the lubricating oil supply amount Q (cc / min) per nozzle is the formula (2) 5 ≦ Q ≦ 200 (2)
Of course, it is a precondition to satisfy the condition.

[Second aspect: Condition definition for lower lubricating oil supply device]
The lubricating oil supply facility of the cold rolling mill of the second aspect of the present invention is the lubricating oil supply facility of the first aspect,
The lower lubricating oil supply device is
A group of nozzles in which a plurality of nozzles for gas atomization lubrication in which the lubricant injection direction is set upward from the horizontal direction are arranged in the plate width direction of the metal sheet to be rolled;
A pump device common to or separate from the pump device of the upper lubricating oil supply device, for pumping the lubricant stock solution toward the nozzles;
A distribution device that distributes the lubricating oil pumped from the pump device to the nozzles;
A plurality of piping parts connecting the outlet part of the distributor and the inlet side connection port of each nozzle;
With
In the distribution device, each outlet portion that sends out the lubricating oil toward each nozzle through each piping portion is provided at the highest position of the lubricating oil flow path in the distribution device,
The vertical position of each pipe part at the nozzle entrance side connection port is set to a position higher than the position of each outlet part of the distribution device.
Also in this second aspect, in the following description, the lubricating oil stock solution that is pumped from the pump device to the respective nozzles of the nozzle group through the distributor and each piping portion may be simply referred to as “lubricating oil”. .

[Operation and effect of the second aspect]
As a lubricating oil supply device for the lower side, the lubricating oil supply nozzle installed on the lower side of the metal plate to be rolled such as a thin steel strip is sprayed upward from the horizontal direction in the same manner as a general one. Is installed. Accordingly, on the surface of any one or more of the lower work roll, intermediate roll, and backup roll (here, these are collectively referred to as the lower roll) and / or on the entrance side of the rolling mill Cold rolling is performed while supplying lubricating oil to the lower surface of the metal sheet to be rolled.

  Here, in the distribution device of the lower-side lubricating oil supply device, each outlet portion that feeds the lubricating oil toward each nozzle through each pipe portion is provided at the highest position of the lubricating oil flow path in the distribution device. Thus, the lubricating oil flow path in the distribution device can always be filled with lubricating oil, as described for the upper-side lubricating oil supply device of the first aspect.

  Furthermore, in the lower lubricating oil supply device, the nozzle is installed so that the lubricating oil injection direction from the nozzle is upward from the horizontal direction. Is set at a position higher than the position of the outlet portion of the distribution device (in other words, if the outlet portion of the distribution device is set lower than the connection port with the nozzle pipe), Lubricating oil injection stops almost at the same timing as the lubricating oil OFF operation. The piping between the nozzle and the distributor when the lubricant injection stops is almost filled with lubricant, so the next time the lubricant is turned on, each nozzle group is Lubricating oil injection starts from the nozzle. That is, it is possible to avoid the occurrence of uneven supply of the lubricating oil in the plate width direction by starting the injection of the lubricating oil from each nozzle at substantially the same timing when the lubricating oil supply is turned on.

[Third Aspect]
According to the third aspect of the present invention, on the premise of the first or second aspect, the upper lubricating oil supply device uses a lubricating oil that solidifies at around room temperature, and the supply of the lubricating oil is stopped for a long time. In this case, the lubricating oil in the pipe or the distribution device is a mode for dealing with the problem of solidification.
That is, the lubricating oil supply facility of the cold rolling mill of the third aspect is the lubricating oil supply facility of the first or second aspect,
A branch switching valve provided in the pipe portion;
A circulation pipe for returning the lubricating oil to the tank from the branch switching valve;
A cleaning liquid supply mechanism connected to the branch switching valve;
Have
The cleaning liquid supply mechanism is configured to flow the cleaning liquid having a temperature of 40 ° C. or more at the position of the branch switching valve from the branch switching valve toward the nozzle while the lubricating oil is circulated through the circulation pipe. It is characterized by that.

[Prior art corresponding to the third aspect]
Some cold rolling lubricating oils solidify around room temperature. In conventional emulsion lubrication supply devices, the lubricating oil tank is provided with a heating and heat retaining mechanism and a stirring device to keep the lubricating oil at a certain temperature. So that the lubricating oil is not solidified by piping or the like. In an emulsion lubrication device, particularly a circulating emulsion lubrication supply device, it is common to use an emulsion as a coolant for cooling the roll, and even when a metal plate such as a thin steel strip is not rolled, the roll is used. Emulsion lubrication is supplied to the pipe so that the lubricating oil does not solidify in the pipe.
However, in the lubricating oil supply facility by gas atomization, in addition to flowing the lubricating oil stock solution into the pipe, the supply of the lubricating oil must be completely stopped when the sheet steel strip is not rolled. In that case, if the lubricating oil remains in the distributor, piping and nozzle and the temperature drops to the room temperature level, the lubricating oil will solidify, and it will be smooth due to troubles such as nozzle clogging and piping clogging when the next lubricating oil is supplied. Lubrication oil may not be supplied.

[Operational effect of the third aspect]
When using a lubricant that solidifies near room temperature in a gas atomized lubricant supply facility, is the lubricant completely removed from the lubricant flow path of the lubricant supply facility before the lubricant supply stops for a long period of time? It is necessary to keep flowing lubricating oil at all times. Therefore, in the third aspect of the present invention, when a branch switching valve is provided in the middle from the outlet portion of the distributor to the nozzle entrance side connection port, and lubricating oil is not injected for a long time, the branch switching valve is operated. Lubricating oil that is pumped from the distributor to the nozzle can be returned to the tank, and instead, the cleaning liquid can be flowed from the branch switching valve toward the nozzle, and the lubricating oil that tends to solidify can be removed from the piping and nozzle. .

[Fourth aspect]
According to a fourth aspect of the present invention, on the premise of the second aspect or the third aspect, the lower lubricating oil supply device uses a lubricating oil that solidifies at around room temperature, and the supply of the lubricating oil is prolonged. This is a mode for coping with the problem of solidification of the lubricating oil in the piping and the distribution device when the operation is stopped for a time.
That is, the lubricating oil supply facility of the cold rolling mill of the fourth aspect is the lubricating oil supply facility of the second or third aspect,
The lower lubricating oil supply device further comprises:
A circulation pipe for returning the lubricating oil to the tank from the branch switching valve;
A cleaning liquid supply mechanism connected to the branch switching valve;
Have
The cleaning liquid supply mechanism is configured to flow the cleaning liquid having a temperature of 40 ° C. or more at the position of the branch switching valve from the branch switching valve toward the nozzle while the lubricating oil is circulated through the circulation pipe. It is characterized by that.

[Operational effect of the fourth aspect]
The operational effect of the lower-side lubricating oil supply device in this fourth aspect is substantially the same as the operational effect of the upper-side lubricating oil supply device in the above-described third aspect, and therefore the description thereof is omitted. .

[Fifth aspect]
Furthermore, a fifth aspect of the present invention is characterized in that in the lubricating oil supply equipment according to any one of the first to fourth aspects, an emulsion lubrication supply equipment is provided side by side.

[Function and effect of the fifth aspect]
According to a fifth aspect of the present invention, there is provided a lubricating oil supply facility in which a conventional circulating emulsion lubrication supply facility is combined with any of the lubricating oil supply facilities by gas atomized lubrication according to the first to fourth aspects of the present invention. This is equipped with an emulsion lubrication supply facility that also serves as a roll cooling function as a facility for supplying lubricant to the upper and lower rolls, and an auxiliary lubricant supply that supplies lubricant to the upper and lower surfaces of the sheet steel strip on the entrance side of the rolling mill As equipment, a lubricating oil supply equipment by gas atomized lubrication according to any one of the first to fourth aspects of the present invention is provided. In addition, it is preferable that the lubricating oil used by the circulation type emulsion lubrication supply equipment and the aspect in any one of the 1-4 of this invention is the same. Different lubricating oils can be used as long as they do not produce a reaction product even when they are mixed with each other and the lubricity does not change greatly.

  According to the lubricating oil supply facility of the cold rolling mill of the present invention, a plurality of nozzles are installed in the sheet width direction of the metal sheet to be rolled, and the lubricating oil stock solution is added to the roll and / or metal sheet to be rolled together with the gas. When supplying the spray, the timing of starting and stopping the injection from each nozzle is almost the same, so there are places where the lubricating oil is supplied in the board width direction and places where it is not supplied. Lubrication supply unevenness can be eliminated, and furthermore, a mode in which piping clogging does not occur even after a long period of stoppage of lubrication supply can be achieved, so that smooth lubrication supply is possible. This makes it easy to exert an excellent lubrication effect with the minimum required amount of lubricating oil supply, which is a feature of the gas atomized lubricating oil supply method, and enables more stable lubrication rolling, thereby improving productivity by improving the rolling mill operating rate. Yield improvement and product yield improvement can be achieved.

It is the schematic diagram which looked at an example of the structure of the part from a distribution apparatus to a nozzle about the upper side lubricating oil supply apparatus in the lubricating oil supply equipment of 1st Embodiment from the plate width direction of the to-be-rolled material. It is the schematic diagram which looked at an example of the structure of the part from a distribution apparatus to a nozzle about the lubricating oil supply apparatus for upper sides in the lubricating oil supply equipment of 1st Embodiment from the rolling direction. It is the schematic diagram which looked at an example of the structure of the part from a distribution apparatus to a nozzle about the lower side lubricating oil supply apparatus in the lubricating oil supply equipment of 2nd Embodiment from the plate width direction of the to-be-rolled material. It is the schematic diagram which looked at an example of the structure of the part from a distribution apparatus to a nozzle about the lower lubricating oil supply apparatus in the lubricating oil supply equipment of 2nd Embodiment from the rolling direction. It is a schematic diagram which shows an example of the whole structure of the upper side lubricating oil supply apparatus or the lower side lubricating oil supply apparatus in the lubricating oil supply equipment of this invention.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment: First Embodiment]
In the lubricating oil supply facility of the present invention, a gas-liquid two-fluid nozzle, that is, a nozzle for gas atomization lubrication is used as a nozzle for lubrication, and the plurality of nozzles are installed side by side in the plate width direction of the metal sheet to be rolled. Thus, a nozzle group is configured.
And in 1st Embodiment, the conditions of the upper lubricating oil supply apparatus are prescribed | regulated among the upper lubricating oil supply apparatus which comprises the lubricating oil supply equipment, and the lower lubricating oil supply apparatus, This upper side is prescribed | regulated. In the case of the lubricating oil supply apparatus for use, as will be described in detail later, each nozzle is installed in a direction in which the lubricating oil is injected downward with respect to the horizontal direction.

An example of the configuration of the portion between the distributor 1 and one nozzle 2 in the nozzle group 2A in the upper lubricating oil supply device 100 of the embodiment (first embodiment) of the first aspect, FIG. 1 shows the state viewed from the plate width direction, and FIG. 2 shows a configuration between the distribution device 1 and each nozzle 2 of the nozzle group 2A in the upper lubricating oil supply device 100 of the first embodiment. An example is shown as viewed from the rolling direction.
As shown in FIG. 1, the distribution device 1 in the upper lubricating oil supply device 100 has a lubricating oil stock solution pumped from a pump device (not shown) (hereinafter, this lubricating oil stock solution is simply referred to as “lubricating oil”). ) Is supplied to the distribution device 1 by the pipe 4. When using the lubricating oil supply device of the present invention, before use, the lubricating oil is filled in the pipes 3 installed in the distribution device 1 and from the outlet portions 5 toward the nozzles 2 in advance. It is necessary to keep. The cross-sectional area of the inner diameter of each pipe 3 need not be uniform, but it is desirable to use the same cross-sectional area and the same length as much as possible in order to keep the pressure loss constant and reduce the variation between the nozzles as much as possible. Each pipe 3 connected from the outlet portion 5 of the distribution device 1 toward each nozzle 2 is connected to a connection port (inlet connection port) 6 for supplying lubricating oil in each nozzle 2.
The lubricating oil 8 supplied from the outlet portion 5 of the distribution device 1 through the piping 3 toward the lubricating oil inlet side connection port 6 of the nozzle 2 together with the gas separately supplied to the nozzle 2 through the piping device 9 It is sprayed from the nozzle 2 toward the upper roll and / or the surface of the metal sheet to be rolled, and gas atomized lubrication is performed.

  In the piping path from each outlet portion 5 of the distribution device 1 to the inlet side connection port 6 of each nozzle 2 in the upper lubricating oil supply apparatus 100, the portion 7 and the nozzle 2 entering the maximum height in each piping 3 enter. The pipe length 10 between the side connection port 6 corresponds to the pipe length L defined by the equation (3). Here, the average cross-sectional area S of the inner diameter of the pipe in the expression (3) is an average flow path cross-sectional area in the pipe of the length L defined by 10 in FIG. 1, and satisfies the above-described expression (1). It is prescribed as follows. In each of these pipes 3, lubricating oil of the lubricating oil supply amount Q per nozzle defined by the equation (2) flows.

  For the piping path from the distribution device 1 to each nozzle 2, from the height of each outlet portion 5 of the distribution device 1 to the maximum height position 7 in the middle of the piping, the maximum height position 7 must be exceeded. Such a route may be used. It is preferable that the pipes 2 in the meantime be installed along a route that rises as monotonously as possible from the outlet portions 5 of the distribution device 1. Moreover, there is no restriction | limiting in particular about the piping length from each exit part 5 of the distribution apparatus 1 to the maximum height position 7 in the middle of piping, but if possible, it is preferable within 5 m.

  As for the piping path from the position of the maximum height position 7 to the nozzle 2 in the middle of the piping, there is no problem even if the piping from the maximum height position 7 to the nozzle 2 can be partly lower than the nozzle height in the middle. However, it is desirable to set the piping path so as to gradually decrease from the maximum height position 7 toward the nozzle direction.

  As shown in FIGS. 1 and 2, each nozzle 2 of the nozzle group 2A in the upper lubricating oil supply apparatus 100 is installed so as to inject lubricating oil downward in the horizontal direction. The downward angle, i.e., the injection direction, may be close to horizontal or may be the direction of injection directly below. Moreover, each nozzle 2 may be installed so that it may inject toward the upper surface of a to-be-rolled material metal plate, for example, a sheet steel strip, or may be installed so that it may inject toward an upper roll. Each nozzle 2 constituting the nozzle group 2A, that is, the plurality of nozzles 2 arranged side by side in the plate width direction of the metal sheet to be rolled need not be arranged at equal intervals, and an appropriate injection width of the nozzle to be used As long as the lubricating oil can be injected and supplied over the entire width of the plate, it may be arranged at any interval. In addition, each nozzle 2 is arranged at different heights to supply lubricating oil from one distributor 1 to the surface of the upper roll, that is, one or more surfaces of the work roll and the intermediate roll or backup roll thereon. May be.

  However, the path of each pipe 3 from the distributor 1 to each nozzle 2 must satisfy the conditions defined in the first aspect of the present invention. The number of pipes 4 from a pump device (not shown) for supplying lubricating oil to the distribution device 1 is not necessarily one, and lubricating oil may be supplied to the distribution device 1 from a plurality of pump devices. In addition, with respect to the number of nozzles 2, in consideration of the maximum plate width of a rolled metal plate such as a thin steel strip rolled by an applied rolling mill, contact with the rolled metal plate in the upper roll body What is necessary is just to determine the number of nozzles so that lubricating oil can be supplied to the whole partial surface and / or the surface of the full width of the metal sheet to be rolled.

  The distribution device 1 may have the same configuration as the rolling oil distribution device that is conventionally used for the rolling oil supply path in the lubrication equipment of a cold rolling mill, and the specific configuration is not particularly limited. It is necessary to set the part 5 so as to be positioned at the highest position of the lubricating oil flow path in the distributor.

  1 and 2 do not show the lower lubricating oil supply device, but in the case of the first embodiment (corresponding to the first aspect), the lower lubricating oil supply device is basically Is not particularly limited, and may be the same as the conventional one. However, it is desirable to apply the configuration of the lower lubricating oil supply device described next as the second embodiment (corresponding to the second mode) with reference to FIGS. 3 and 4.

[Second Embodiment]
The second embodiment is an embodiment of the second aspect, and the lower lubricating oil among the upper lubricating oil supply device and the lower lubricating oil supply device constituting the lubricating oil supply facility. It defines the conditions of the supply device. In the case of the lower lubricating oil supply device, as in the upper lubricating oil supply device of the first embodiment, a gas-liquid two-fluid nozzle, that is, a gas atomized lubricating nozzle, is used as the lubricating nozzle. The plurality of nozzles are installed side by side in the plate width direction of the metal sheet to be rolled to constitute a nozzle group. In the lower-side lubricating oil supply device of the second embodiment, each nozzle is installed in a direction in which the lubricating oil is jetted upward in the horizontal direction, as will be described in detail later.
An example of the configuration of the portion between the distributor 1 and one nozzle 2 ′ in the nozzle group 2A ′ in the lower-side lubricating oil supply device of the second embodiment is viewed from the plate width direction. 3, FIG. 4 shows an example of the configuration from the distribution device 1 ′ to the nozzles 2 ′ of the nozzle group 2 </ b> A ′ in the lower-side lubricating oil supply device of the second embodiment. Shown from the direction. 3 and 4 do not show the upper lubricating oil supply device, it may be the same as the upper lubricating oil supply device 100 of the first embodiment shown in FIGS.

  As shown in FIG. 3 and FIG. 4, each nozzle 2 ′ in the lower lubricating oil supply device 100 ′ is designed to inject the lubricating oil upward with respect to the horizontal direction. That is, the injection direction may be close to horizontal or directly above. Pipes 3 ′ are connected from the respective outlet portions 5 ′ of the distribution device 1 ′ toward the lubricating oil inlet side connection ports 6 ′ of the respective nozzles 2 ′, and the lubricating oil 8 together with the gas separately supplied to the respective nozzles 2 ′. 'Is sprayed from each nozzle 2' to the lower roll and / or the lower surface of the metal sheet to be rolled.

  Here, the size of the pipe 3 ′ used for the lower lubricating oil supply device 100 ′ is not particularly limited, but is used in the upper lubricating oil supply device 100 of the first mode (first embodiment). It is preferable to use the same as those. This is the piping 2 of the upper lubricating oil supply device 100 of the first aspect (first embodiment) and the second aspect (second embodiment) used as the lower lubricating oil supply device. This is because when the cross-sectional area of the inner diameter is different between the piping 2 ′ of the lower lubricating oil supply device 100 ′, a phenomenon may occur in which the lubricating oil injection timing is slightly different between the upper and lower sides.

  There are no particular restrictions on the location of the nozzle 2 'for the metal sheet to be rolled such as a thin steel strip or the lower roll. It is only necessary to determine the installation location of the nozzle 2 ′ so that there is no place where the lubricant is not supplied to an object to which the lubricant is injected in consideration of the injection angle of the nozzle.

  Here, the path of each pipe 3 ′ from the outlet 5 ′ of the distributor 1 ′ to the nozzle 2 ′ in the lower lubricating oil supply device 100 ′ is the height defined in the second aspect described above. As long as the relationship is satisfied, any route may be used, but it is desirable that the nozzle is gradually raised from the outlet portion 5 ′ of the distributor 1 ′ to reach the nozzle installation height as much as possible. In addition, when installing a nozzle so that it may inject upward rather than a horizontal direction, the internal-diameter cross-sectional area and length of piping between a nozzle and a distribution device do not have a restriction | limiting in particular. However, it is preferable to connect with a pipe that is as thin and short as possible so as to fit within the equipment of the rolling mill.

  As shown in FIG. 3 and FIG. 4, each nozzle 2 ′ in the lower lubricating oil supply device 100 ′ is directed upward if it is designed to inject lubricating oil upward with respect to the horizontal direction. The angle, ie the injection direction, may be close to horizontal or directly above. The nozzles 2 ′ constituting the nozzle group 2A ′, that is, the plurality of nozzles 2 ′ installed side by side in the sheet width direction of the metal sheet to be rolled do not need to be arranged at equal intervals. As long as the lubricating oil can be injected and supplied to the entire plate width with a small injection width, they may be arranged at any interval. In addition, in order to supply the lubricating oil from one distributor 1 'to two or more of the work roll and the backup roll or intermediate roll in contact with the work roll, the nozzles 2' may be arranged at different heights.

However, the path of each pipe 3 ′ from the distribution device 1 ′ connected to each nozzle 2 ′ in the lower lubricating oil supply device 100 ′ must satisfy the conditions specified in the second embodiment. I must. The number of nozzles, the number of pipes, and the like may be appropriately determined as in the first mode (first embodiment).
In addition, the distribution device 1 ′ may have a configuration similar to that of a rolling oil distribution device that is conventionally used for a rolling oil supply path in a lubrication facility of a cold rolling mill, and the specific configuration is not particularly limited. It is necessary to set the outlet 5 ′ so as to be positioned at the highest position of the lubricating oil flow path in the distributor.

[Overall Configuration of Lubricating Oil Supply Device; Application Example of Fourth Mode]
In FIG. 5, it shows as an example which applied the above-mentioned 4th aspect about the whole structure of an example of the lubricating oil supply equipment of this invention. In FIG. 5, the upper lubricating oil supply device 100 and the lower lubricating oil supply device 100 ′ constituting the lubricating oil supply facility are shown without being distinguished from each other. 100 and lower lubricating oil supply device 100 ′ may be applied. That is, the configuration of the piping path from the distributor 1 (1 ′) to each nozzle 2 (2 ′) and the nozzle direction (upward and downward) is the upper lubricating oil supply device 100 of the first embodiment. The lower-side lubricating oil supply device 100 ′ of the second embodiment may be used. In other words, the lubricating oil supply apparatus shown in FIG. 5 is applicable to both the first aspect and the second aspect.
In FIG. 5, in order to make the arrangement configuration easy to understand, equipment such as piping for supplying gas for injection to the nozzle 2 (2 ′) is omitted. Further, for the path from the distributor 1 (1 ′) to each nozzle 2 (2 ′) of each nozzle group 3 (3 ′) and each nozzle 2 (2 ′), a plurality of paths and a plurality of nozzles are provided. Of these, only one path and one nozzle are shown.

The lubricating oil supply facility shown in FIG. 5 to which the fourth aspect is applied will be described below.
The lubricating oil 14 stored in the lubricating oil tank 13 passes through the pipe 15 and is pumped through the pipe 4 (4 ′) by the pump device 12 to the distribution device 1 (1 ′). Although not shown in FIG. 5, the lubricating oil tank 13 is preferably provided with a heating device, a temperature regulator, and a stirrer in order to keep the temperature of the lubricating oil constant. As described above, each outlet 5 (5 ′) of the distributor is connected to each nozzle 2 (2 ′) by each pipe 3 (3 ′), and a branch switching valve 11 is connected to the middle of the pipe. ing. A pipe 16 is provided for returning the lubricating oil from the branch switching valve 11 to the tank, and provides a path for returning the lubricating oil from the branch switching valve 11 to the tank 13 so that the lubricating oil circulates. By this circulation, even if cold rolling lubricating oil that is easily solidified is used, the lubricating oil can be smoothly supplied without solidifying inside the pipe.

  The lubricating oil tank 13 may be shared by the upper lubricating oil supply device 100 and the lower lubricating oil supply device 10 ′, and the pump device 12 may be shared with the upper lubricating oil supply device 100. Although it can be shared by the side lubricating oil supply device 100 ′, in some cases, these may be provided separately by the upper lubricating oil supply device 100 and the lower lubricating oil supply device 100 ′.

  The cross-sectional area of the inner diameter of the pipe 16 that returns the lubricating oil from the branch switching valve 11 is preferably a pipe 3 (3 ') or larger. In addition, there is no restriction | limiting in particular about the path | routes, such as the installation height of the piping 16, and it should just be able to return to a lubricating oil tank, but it is as short as possible in order to make smooth lubricating oil supply easy. It is preferable to select the route of the pipe 16 so as to avoid this.

  When the branch switching valve 11 returns the lubricating oil 14 to the tank 13, the cleaning liquid 18 flowing from the cleaning liquid pipe 20 at the same time is supplied to the nozzle 2 (2 ′) via the branch switching valve 11. Make it flow toward. Further, at the same time as flowing the lubricating oil 14 sent from the distributor 1 (1 ′) to the piping 16 for returning to the lubricating oil tank 13, the cleaning liquid 18 flowing through the cleaning liquid piping 20 is allowed to flow. It is set as the structure which flows into piping which goes to the nozzle 2 (2 ').

  On the other hand, the branch switching valve 11 causes the lubricant 14 to flow from the distributor 1 (1 ') toward the nozzle 2 (2') when the lubricant is injected from the nozzle 2 (2 '). At this time, the piping 16 side for returning the lubricating oil 14 and the cleaning liquid piping 20 must be shielded from the flow path of the lubricating oil 14.

  The cleaning liquid 18 is sent to the branch switching valve 11 by a pump device 19 that pumps the cleaning liquid from a tank 17 that stores the cleaning liquid. The timing at which the cleaning liquid 18 is pumped by the pump device 19 may be such that the pump device 19 is activated and the cleaning liquid is pumped toward the nozzle 2 (2 ′) at the same time as the branch switching valve 11 is switched. A relief valve (not shown) is provided between the cleaning liquid pressure pumping device 19 and the branch switching valve 11, and a circulation path is provided so as to return to the cleaning liquid tank 17 from the relief valve. While the branch liquid is constantly circulated, the pressure may be reduced when the branch switching valve 11 is switched, the relief valve is closed, and the cleaning liquid 18 may flow toward the branch switching valve 11. The size of the pipe for pumping the cleaning liquid 18 may be any size, but it is preferable to use the same size as the pipe 3 (3 ') as much as possible.

  The tank 17 that stores the cleaning liquid and the pump device 19 that pumps the cleaning liquid may be shared by the upper lubricating oil supply device 100 and the lower lubricating oil supply device 100 ′. These may be provided separately in the upper lubricating oil supply device 100 and the lower lubricating oil supply device 100 ′.

  As for the supply amount of the cleaning liquid, it is preferable that the amount of the lubricating oil supplied per nozzle is about the maximum supply amount, preferably about 5 minutes, and at least about 1 minute. If it is less than 1 minute, the cleaning effect is not sufficiently obtained, and the solidified component of the lubricating oil gradually accumulates inside the pipe 3 (3 ′), so that it does not cause clogging of the pipe immediately, but continues. There is a risk of clogging the piping while it is being used. The cleaning liquid tank 17 is not necessarily provided with a mechanism for keeping the temperature of the cleaning liquid constant. This is because a normal cleaning liquid does not solidify at room temperature.

  As the cleaning liquid, water, warm water, soapy water or the like may be used, but in addition, for using the lubricating oil supply facility of the present invention to gas atomize and inject the metal plate or roll to be rolled. A lower concentration emulsion lubrication formed using the same lubricating oil as the lubricating oil may be used. Thus, the emulsion concentration in the case of using low-concentration emulsion lubrication as a cleaning liquid is such that the volume% of the lubricating oil with respect to water is 0.5% to 10% by volume, preferably 0.8% to 2% by volume. It is. In addition, the timing at which the cleaning liquid starts to flow does not necessarily start immediately after the branch switching valve is switched, but the cleaning liquid starts to flow within 5 minutes after the branch switching valve is switched. Is preferred. This is because if it is slower than this, the temperature at the tip of the nozzle cools and solidification of the lubricating oil starts. As for the temperature of the cleaning liquid, the temperature at the time of passing through the branch switching valve needs to be 40 ° C. or higher, preferably 50 ° C. or higher. This is because if the temperature is lower than this, the temperature is lowered in the pipe and the solidification of the lubricating oil may be promoted before the lubricating oil is removed from the pipe.

[Embodiment for Fifth Aspect]
According to a fifth aspect of the present invention, a conventional general circulation emulsion lubrication supply device is used as equipment for supplying lubricating oil to a roll, and the lubricating oil according to any one of the first to fourth aspects of the present invention is used. The supply facility is used as a facility for supplying lubricating oil to the upper or lower surface or upper and lower surfaces of the metal sheet to be rolled on the entrance side of the rolling mill, or a conventional general circulating emulsion lubrication supply device Is used as equipment for supplying lubricating oil to the upper surface or lower surface or upper and lower surfaces of the metal sheet to be rolled on the rolling mill entering side, and the lubricating oil supply facility according to any one of the first to fourth aspects of the present invention is used. It is used as equipment for supplying lubricating oil to the roll.
Considering productivity and lubricating oil cost, the former circulating emulsion lubrication supply device is used as the lubricating oil supply equipment for the former roll, and the upper or lower surface of the metal sheet to be rolled on the entrance side of the rolling mill Alternatively, it is preferable to use the lubrication equipment according to any one of the first to fourth aspects of the present invention as equipment for supplying lubricating oil to the upper and lower surfaces.

[Lubricating oil supply amount in the first to fourth aspects]
The supply amount of the lubricating oil may be determined according to the rolling operation conditions based on the definition of any one of the first to fourth aspects of the present invention. Further, the gas injected from the nozzle for atomization may be anything as long as it is a nonflammable gas. For example, air, argon, nitrogen, helium, etc. are preferable. The pressure at the time of jetting is preferably greater than 0.05 MPa and preferably in the range of 0.5 MPa or less. When the pressure is 0.05 MPa or less, the injection speed of the lubricating oil is low, and it is difficult to reliably supply the lubricating oil to the injection target in the environment inside the rolling mill. If the pressure is larger than 0.5 MPa, the amount of the lubricating oil adhering to the injection target decreases, and the amount of the lubricating oil component that does not adhere and scatters to other locations increases, and as a result, the required lubricity is obtained. This is because a lot of lubricating oil must be supplied.

Examples of the present invention are shown below together with comparative examples.
When cold-rolling a steel sheet with a cold tandem rolling mill consisting of a 4-stand 6-roll mill, the installation conditions for the upper-side lubricating oil supply device and the lower-side lubricating oil supply device in the third stand are varied. Then, rolling was performed while performing gas atomization lubrication, and the presence or absence of squeezing due to poor lubrication at that time and the occurrence state of seizure flaws of the steel sheet caused by severe squeezing were investigated.
The plate thickness of the steel plate immediately before rolling at the third stand is about 0.95 mm, and the target plate thickness after rolling is 0.68 mm. The rolling speed during normal steady rolling is about 390 m / min. A lubricating oil having a kinematic viscosity at 40 ° C. of 60 cSt was used.

  In addition, as the nozzles of each lubricating oil supply device, 16 nozzles in the width direction are provided so that the lubricating oil is supplied to the steel sheet at a position about 2.5 m away from the roll center of the third stand on the entrance side of the rolling mill, The state of occurrence of throttling due to uneven discharge of the lubricating oil from the nozzle arranged in the width direction of the lubricating oil when the lubricating oil was turned on was installed. Normally, it takes about 7 to 9 seconds to increase the rolling speed from the rolling stop state to the maximum speed, but this time the purpose is to investigate the occurrence of drawing due to uneven supply of lubricant in the width direction. Therefore, for the lubricating oil supply device for the upper side, the length of L defined by the equation (3) and the average cross-sectional area S and the lubricating oil supply amount Q of the pipes constituting the equation (3) are set. In addition, regarding the lower lubricating oil supply device, the positional relationship in the vertical direction between the position of the outlet portion of the distributor and the position of the nozzle-side connection port was changed.

  Then, the ON / OFF operation of the lubricating oil was performed when rolling at a steady speed, and the occurrence of drawing in the steel sheet when the operation was performed was investigated. As a result, the L, S, and Q values of the upper lubricating oil supply device, and the positional relationship in the vertical direction between the position of the outlet portion of the distributor and the position of the nozzle-containing side connection port in the lower lubricating oil supply device In addition, it is shown in Table 1. Regarding the lower lubricating oil supply device, in Table 1, D1 is set when the outlet height of the distribution device is higher than the nozzle-side connection port, and D2 is set when the outlet height is lower. However, due to the installation space, even when D2 is low, the height difference is about 4 cm.

In Table 1, Comparative Example 1 and Comparative Example 2 are examples in which the upper lubricating oil supply device is outside the condition range of the first aspect and the lower lubricating oil supply apparatus is out of the range of the second aspect. It is.
Inventive Example 1 and Inventive Example 2 are examples in which the upper lubricating oil supply device is within the condition range of the first aspect, but the lower lubricating oil supply apparatus is outside the range of the second aspect.
Inventive Example 3 and Inventive Example 4 are examples in which the upper lubricating oil supply device is within the condition range of the first aspect, and the lower lubricating oil supply facility is within the range of the second aspect.

  The evaluation shown in Table 1 is as follows: ◎ when no squeezing occurred, ◯ when a squeezing occurred, a mild squeezed state where no poor quality such as seizure flaws occurred on the steel sheet, and seizure flaws generated on the steel sheet A state in which such an intense diaphragm was generated was indicated as x.

As shown in Table 1, the upper lubricating oil supply device does not satisfy the condition of the first aspect of the present invention, and the lower lubricating oil supply apparatus does not satisfy the condition of the second aspect of the present invention. In the case of Example 1 and Comparative Example 2, intense drawing occurred so that seizure flaws occurred on the steel sheet.
On the other hand, the upper lubricating oil supply apparatus satisfies the conditions of the first aspect of the present invention, and the lower lubricating oil supply apparatus satisfies the conditions of the second aspect of the present invention. If the aperture did not occur.
Further, the upper lubricating oil supply device satisfies the conditions of the first aspect of the present invention, and the lower lubricating oil supply apparatus does not satisfy the conditions of the second aspect of the present invention. In this case, even when the squeezing occurred, a mild squeezed state was generated in which no quality defect such as seizure flaw occurred on the steel sheet.

Therefore, from these results, by using the lubricating oil supply facility of the present invention, uneven lubrication oil supply in the width direction of the lubricating oil is reduced, and the occurrence of throttling due to uneven lubrication oil supply in the width direction is reduced. It has been found that it is possible to stably supply the lubricating oil without causing quality defects such as seizure flaws.
Here, if the lubricating oil ON is appropriately performed by the upper lubricating oil supply device, unevenness in the lubricating oil is less likely to occur, and the occurrence of poor quality of the steel sheet that is likely to occur due to the uneven supply of lubricating oil is also suppressed. On the other hand, the lower-side lubricating oil supply device has a smaller installation space than the upper side and is unlikely to have a difference in height between the outlet portion of the distributor and the nozzle connection port, but with the configuration of the second aspect of the present invention. If so, the occurrence of uneven lubrication oil supply is substantially suppressed. However, even if the lower-side lubricating oil supply device does not satisfy the second aspect, if the upper-side lubricating oil supply apparatus satisfies the conditions of the first aspect, lubrication that causes a quality failure of the steel sheet. It was confirmed that there was no squeezing caused by uneven oil supply.

1,1 'Distributor 2,2' Gas atomized lubrication nozzle (gas-liquid two-fluid nozzle)
2A, 2A 'Nozzle group 3, 3' Lubricating oil piping 4, 4 'Lubricating oil piping 5 Distributor outlet 6 Nozzle lubricating oil inlet connection port 7 Maximum height of piping (3, 3') Position 8, 8 'Lubricating oil (injection cone) injected from nozzle (2, 2')
9, 9 'Piping device 10 for pumping gas to the nozzle 10 Length between the position of the maximum height of the piping and the inlet side connection port for lubricating oil of the nozzle 12 Branch switching valve 12 Pump device for feeding lubricating oil pressure DESCRIPTION OF SYMBOLS 13 Lubricating oil tank 14 Lubricating oil 15 Piping 16 Piping 17 Cleaning liquid tank 18 Cleaning liquid 19 Pump apparatus 20 for pumping cleaning liquid 20 Piping 100 for pumping cleaning liquid Upper lubricating oil supply apparatus 100 '' Lubricating oil supply device for lower side

Claims (5)

An upper lubricating oil supply device for lubricating the upper surface side of the metal sheet to be rolled and / or the upper roll surface of the rolling mill by gas atomization lubrication;
A lower lubricating oil supply device for lubricating the lower surface side of the metal sheet to be rolled and / or the lower roll surface of the rolling mill by gas atomized lubrication,
The upper lubricating oil supply device is
A group of nozzles in which a plurality of nozzles for gas atomization lubrication in which the lubricant injection direction is set downward from the horizontal direction are arranged in the plate width direction of the metal sheet to be rolled;
A pump device for pumping the lubricant stock solution toward the nozzles;
A distribution device that distributes the lubricating oil pumped from the pump device to the nozzles;
A plurality of piping portions connecting between the outlet portions of the distributor and the inlet side connection ports of the nozzles;
With
In the distribution device, each outlet portion that sends out the lubricating oil toward each nozzle through each piping portion is provided at the highest position of the lubricating oil flow path in the distribution device,
Each piping part is disposed so that the position of the highest position in the vertical direction in the piping part is located above each outlet part of the distributor,
The average channel cross-sectional area S (cm ² ) in the pipe portion satisfies the following formula (1), and the lubricating oil supply amount Q (cc / min) per nozzle satisfies the following formula (2). The pipe length L (cm) from the highest point in the vertical direction to the inlet connection port of each nozzle in each pipe part is configured to satisfy the following expression (3). Lubricating oil supply equipment for cold rolling mills.
S ≦ 2 (1)
5 ≦ Q ≦ 200 (2)
L ≦ Q / (6 × S) (3) The lower lubricating oil supply device is
A group of nozzles in which a plurality of nozzles for gas atomization lubrication in which the lubricant injection direction is set upward from the horizontal direction are arranged in the plate width direction of the metal sheet to be rolled;
A pump device common to or separate from the pump device of the upper lubricating oil supply device, for pumping the lubricant stock solution toward the nozzles;
A distribution device that distributes the lubricating oil pumped from the pump device to the nozzles;
A plurality of piping parts connecting the outlet part of the distributor and the inlet side connection port of each nozzle;
With
In the distribution device, each outlet portion that sends out the lubricating oil toward each nozzle through each piping portion is provided at the highest position of the lubricating oil flow path in the distribution device,
2. The cold rolling according to claim 1, wherein the vertical position at the nozzle entrance side connection port of each pipe part is set at a position higher than the position of each outlet part of the distribution device. Machine oil supply equipment. A branch switching valve provided in the pipe portion;
A circulation pipe for returning the lubricating oil to the tank from the branch switching valve;
A cleaning liquid supply mechanism connected to the branch switching valve;
Have
The cleaning liquid supply mechanism is configured to flow the cleaning liquid having a temperature of 40 ° C. or more at the position of the branch switching valve from the branch switching valve toward the nozzle while the lubricating oil is circulated through the circulation pipe. The lubricating oil supply equipment for a cold rolling mill according to any one of claims 1 and 2, wherein the lubricating oil supply equipment is provided. The lower lubricating oil supply device further comprises:
A circulation pipe for returning the lubricating oil to the tank from the branch switching valve;
A cleaning liquid supply mechanism connected to the branch switching valve;
Have
The cleaning liquid supply mechanism is configured to flow the cleaning liquid having a temperature of 40 ° C. or more at the position of the branch switching valve from the branch switching valve toward the nozzle while the lubricating oil is circulated through the circulation pipe. The lubricating oil supply equipment for a cold rolling mill according to any one of claims 2 and 3, wherein the lubricating oil supply equipment is provided.   The lubricating oil supply facility for a cold rolling mill according to any one of claims 1 to 4, further comprising an emulsion lubrication supply facility.

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