JPH0320004Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a solid lubricant coating device for hot rolling rolls that effectively applies a solid lubricant to a rolling roll during hot rolling.

[Conventional technology]

In the hot rolling process, the metal material is rolled at a high processing rate. For this reason, the surface of the roll with which the metal material comes into contact changes over a considerable range, and wear of the roll becomes a major problem. This wear of the rolling rolls is particularly noticeable during wide reduction rolling to keep the width of the slab within a predetermined range.

A characteristic of rolling deformation in wide width reduction rolling is that during width reduction, the widthwise rolling force by the vertical rolls does not propagate to the center, resulting in the formation of local thickened areas called dog bones at both ends of the width of the plate. Therefore, it is necessary to perform horizontal rolling to flatten the locally increased thickness portion at an appropriate stage of the wide width reduction rolling process. An example of this will be explained using FIGS. 3 and 4.

In FIG. 3(a), V is a vertical roll with a caliber that rolls down the slab W in the board width direction, and is arranged in two stages, V ₁ and V ₂ as shown in the figure. H is a horizontal roll that rolls down the slab W in the thickness direction. The slab W, which is the material to be rolled, is rolled into a predetermined shape between the above two types of rolling rolls V and H while being reversed. In this rolling process, when the slab W is rolled down by the vertical rolls V, local thickened portions W ₁ are generated at both ends of the width of the slab W, as shown in FIG. 3(b). When this local deformation becomes large,
This causes surface flaws on the material and an increase in rolling power during width direction rolling. For this reason, the thickened part _W1 is temporarily rolled by the horizontal roll H until it becomes the same thickness as the other parts.
The method is to reduce the width by rolling the material in the width direction using vertical rolls V again.

Figures 4(a) and (b) show the slab W in Figure 3(a).
The case where the vertical roll V rotates in the same direction as the direction A in which the slab W advances is called normal rotation [indicated by the solid arrow in Fig. 3 (a)], and the vertical roll V rotates in the same direction as the direction B in which the slab W advances. The case where the local increase in thickness W ₁ of each of the rolls V ₁ and V ₂ on the left side with respect to the traveling direction A is reversed [indicated by the dashed-dotted line arrow in FIG. 3(a)] is This figure shows the state in which it is in contact with the side wall of the caliber.

FIG. 4(a) illustrates the rolling state of a slab W, which is a material to be rolled, in relation to the caliber side wall of the roll _V1 . When the slab W formed into a rectangular shape by the horizontal rolls H is rolled in the width direction by the rolls _V1 , local thickened portions _W11 are generated. This thickened part W ₁₁ is rolled on the caliber side wall V _1a .
Touches V ¹ . When the next repeated rolling is performed, that is, further rolling in the width direction is performed by normal rotation of the roll V ₁ , the locally increased thickness portion W ₁₁ increases in thickness and becomes a thick portion W ₁₂ . This thick part W ₁₂ is connected to the caliber side walls V _1a and V _1b.
and touches roll V ₂ .

FIG. 4(b) illustrates the rolling state of the slab W, which is the material to be rolled, in relation to the caliber side wall of the roll _V2 . When the slab W formed into a rectangular shape by the horizontal roll H is rolled in the width direction while rotating the roll V ₂ in the normal direction, a locally increased thickness is formed.
W ₂₁ occurs. This thickened portion W ₂₁ contacts the roll V ₂ at the caliber side wall V _2a . When the next repeated rolling, that is, rolling in the width direction is further performed by reversing the roll V ₂ , the locally increased thickness portion W ₂₁ increases in thickness and becomes a thick portion W ₂₂ . This thick part W ₂₂
touches the roll V ₁ at the caliber side walls V _2a and V _2b .

Thus, the caliber side walls of rolls V ₁ and V ₂
V _1a and V _2a are in a state in which the locally increased thickness portions W ₁₁ and W ₂₁ of the slab W are in contact with each other when the rolls V ₁ and V ₂ rotate in the normal or reverse direction. On the other hand, the caliber side walls V _1b and V _2b of the rolls V ₁ and V ₂ always touch the thick wall parts W 12 and V _2b of the slab W only when rotating in one direction.
W ₂₂ will be in contact. The locally increased thickness grows only in one direction due to rolling in the width direction, and because the difference in the inner circumferential speed of the caliber is large, the side wall of the caliber
Streamlined roughness tends to occur on V _1b and V _2b . The surface roughness generated on the caliber side walls V _1b and V _2b is transferred to the slab W, which is the material to be rolled, and becomes linear flaws, extremely shortening the life of the roll. On the other hand, the caliber side walls V _1a and V _2a have a small difference in caliber inner peripheral speed, so the occurrence of roll surface roughness is slight. Moreover, the roll on the caliber side walls V _1b and V _2b
Since V ₁ and V ₂ contact the slab W while rotating in both directions, the rough surface disappears and only appears as slight roll wear.

When performing this large-width reduction rolling, the thickness of the locally increased plate thickness increases by about 50 to 100 mm compared to the initial plate thickness. In proportion to this increase in thickness, the surface roughness within the caliber of the vertical roll increases, and the life of the roll becomes extremely short.

By the way, in hot rolling, in order to prevent defects such as heat cracks, wear, and rough skin from occurring on the roll surface, many so-called hydraulic rolling methods are adopted in which liquid hot rolling lubricating oil is supplied to the roll surface during rolling. ing. For this hydraulic rolling, there are generally known methods such as injecting lubricating oil directly onto the roll surface, injecting the lubricating oil as a mixture with water, and applying the lubricating oil using felt. However, in any of these methods, lubricating oil will be mixed into the waste water used for cooling the rolls.

Therefore, an oil recovery device is required, leading to a rise in equipment costs, and problems such as oil smoke, odor, and deterioration of the working environment around the rolling mill are likely to occur. Further, in the felt-type lubricating device, there have been cases where problems such as deformation or damage to the felt, inability to apply oil due to the inclusion of scale, etc., have occurred.

To solve these various problems,
Solid lubricants began to be used. An apparatus for supplying this solid lubricant to rolling rolls is proposed in Japanese Utility Model Application Publication No. 52-94444.

[Problem that the invention attempts to solve]

However, the method proposed in Japanese Utility Model Application Publication No. 52-94444 is effective when the rolling speed is reduced or when rolling is stopped with the material to be rolled near the rolls and the roll gap is being adjusted. Not only does the solid lubricant soften due to the radiant heat of the rolled material, making it impossible to supply it smoothly to the roll surface, but the holding structure also limits the thickness of the lubricant, which requires frequent replacement of the lubricant. , and its workability is poor.

Therefore, the present invention was devised to solve these problems, and its purpose is to obtain an excellent lubrication effect with a small amount of lubricant applied.

[Means for solving problems]

In order to achieve the purpose, the solid lubricant coating device for hot rolling rolls of the present invention has an internal space into which the solid lubricant is slidably inserted, and the solid lubricant is supplied from the air chamber provided at the rear end. The method includes a holder box provided with ventilation holes in the inner wall defining the internal space so as to blow out air toward the rolling rolls along the circumferential surface of the lubricating body.

[Effect]

As a result of researching the effects of various hot lubricating oils and their supply methods on rough surface areas within the caliber, the inventors of the present invention discovered that a method in which liquid hot rolling oil is injected onto the roll surface, as seen in the conventional method, teeth,
The adhesion of the hot rolling oil is weakened by the water film generated from the roll cooling water, and the hot rolling oil is easily washed out by the cooling water, making it impossible to use it effectively. Furthermore, in the conventional method, it is difficult to uniformly apply the hot rolling oil locally.

Therefore, in the present invention, for example, by bringing a solid lubricant into direct pressure contact with the high temperature side wall of the caliber of a vertical roll with a caliber,
The solid lubricant is softened by heat and is firmly applied to the side wall of the caliber. Further, while applying the solid lubricant to the surface of the rolling roll, air is injected between the solid lubricant and the inner peripheral surface of the holder box. This isolates the solid lubricant from the roll cooling water and improves the adhesion rate of the solid lubricant to the roll surface.

The solid lubricant used here is:
It needs to have the strength to remain solid at room temperature and the same lubricating properties as commonly used hot rolling oil during hot rolling. The inventors of the present invention are separately developing a solid lubricant having such lubricating properties.

〔Example〕

An example in which the present invention is applied to a vertical roll with a caliber for wide reduction rolling will be described below.

Fig. 1 shows the overall configuration of a solid lubricant supply device disposed close to the lower side wall of the caliber of a vertical roll with a caliber, and Fig. 2(a) shows the X-X in Fig. 1.
The sectional view, FIG. 2(b) is a YY sectional view of FIG. 2(a).

The solid lubricant supply device has a solid lubricant 1 loosely installed at its tip and an air supply hole 2 at its rear end. The air supply hole 2 is provided with an air piping system 6 connected to an air header 5 via a pressure regulating valve 3 and an on/off solenoid valve 4. In addition, the air supply hole 2
Inside the holder box 7 for the solid lubricant 1 connected to
An air chamber 8 is formed that presses against the rough skin area V _1b (V _2b ) of the side wall (V ₁ , V ₂ ). As a result, the solid lubricant 1 is operated by the caliber vertical roll V (V ₁ , V ₂ ) on the rough skin area V _1b (V _2b ) of the side wall. In addition, since the holder box 7 is connected to the fixed frame 9 via a reciprocating drive mechanism, the roughened area V _1b of the side wall of the caliber
It is possible to swing back and forth along (V _2b ). The reciprocating motion drive mechanism causes the holder box 7 to swing back and forth by transmitting the movement of the cylinder shaft 11 into and out of the hydraulic cylinder 10 to the holder box 7 via the fixed frame 9 and the pin connection culm 12. Note that the fixed frame 9 has an adjustment screw 13
It is attached and fixed to the mounting frame 14 with.

The reciprocating drive mechanism is designed to prevent rough skin within the caliber.
The operation is controlled so that the holder box 7 of the solid lubricant 1 is movable with respect to V _1b (V _2b ). That is, the host computer performs a model calculation of the locally increased plate thickness, the position setting value is instructed to the position control device 15, and the servo valve 16 and position detector 17 control the reciprocating drive mechanism.

In the example shown in FIG. 2(b), a ventilation hole 18 is provided at the inner edge of the holder box 7 of the solid lubricant 1. Air is injected between the solid lubricating body 1 and the inner peripheral surface of the holder box 7 through the ventilation hole 18. As a result, the solid lubricant 1 is slidably inserted into the holder box 7, and the roll cooling water is cut off while the solid lubricant 1 is being applied to the side wall of the caliber. Therefore, the adhesion rate of the solid lubricant 1 to the roll surface is improved.

Although the above explanation regarding the solid lubricant supply device has been made on the lower surface side of the caliber side wall, a device having exactly the same function is also arranged on the upper surface side of the caliber side wall.

The adhesion of hot rolling oil to a vertical roll with a caliber is largely influenced by the wet state of the roll surface. As a result of investigation by the inventors of the present invention, it was found that in the conventional oil supply device with a water jet wiper, a water film remains on the roll surface, so that the adhesion rate of hot rolling oil is only 2 to 5% of the supplied amount. On the other hand, in the lubricant coating device of the present invention, the solid lubricant could be applied to the roll surface with a high adhesion rate since there was no influence of the water film remaining on the roll surface. As a result, the rough surface of the rolling roll is significantly suppressed with a small amount of lubricant applied, and the period until the rough surface of the roll is transferred to the rolled material, that is, the life of the roll, is approximately three times that of conventional rollers. It became possible to make it longer.

[Effect of idea]

As explained above, when using the lubricant coating device of the present invention, the solid lubricant is always air-cooled, and the solid lubricant can be supplied with a constant air pressure. Furthermore, ventilation between the inner surface of the holder and the surface of the solid lubricating body enables cooling of the holder and air lubrication. Therefore, the solid lubricant can be stably and smoothly supplied to the roll surface over a long period of time, so the lubricant can be effectively applied to the necessary parts of the roll without being affected by the water film formed by cooling water. be able to. As a result,
Compared to the conventional method using a water-injection wiper-equipped lubrication device, the amount of hot rolling oil used can be reduced to about 1/20. Further, there is no need to provide a large-scale oil recovery device for post-treatment of lubricating oil mixed in the waste water used for cooling the rolls.

In this way, hot rolling,
In particular, wide reduction rolling can be performed. In addition, the solid lubricant applied to the surface of the roll without being affected by a water film has excellent adhesion, exhibits an excellent effect in preventing rough skin of the roll, and extends the life of the roll. In this way, the present invention brings about great effects in hot rolling.

[Brief explanation of the drawing]

Figure 1 shows the overall configuration of the solid lubricant supply device used in the embodiment of the present invention, and Figure 2 (a) shows the first solid lubricant supply device.
The XX cross-sectional view in the figure, Figure 2 (b) is the Y-Y in Figure 2 (a).
FIG. Moreover, FIGS. 3 and 4 are for explaining the effect on the vertical rolls when a local plate thickness increase occurs during wide-width reduction rolling.

Claims (1)

[Scope of utility model registration request] The interior has an internal space into which the solid lubricating body is slidably inserted, and is configured such that air is blown out from an air chamber provided at the rear end toward the rolling roll along the circumferential surface of the solid lubricating body. A solid lubricant coating device for hot rolling rolls, comprising a holder box having ventilation holes in an inner wall defining a space.