JPH09141305A - Method and device for joining metal piece by continuous hot rolling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the rupture of a plate between stands during rolling and enable hot rolling with high productivity adjusting the vertical intervals of clamp parts which clamp both end parts of the metal pieces when the metal pieces are jointed together. SOLUTION: The end parts of the precedent and following metal pieces S1 and S2 are clamped and supported by couples of upper and lower clamp parts 10a and 10b, and 11a and 11b along the length, and joined together by being heated and then pressing against each other in a line direction. The lamp parts 10a and 10b, and 11a and 11b have clamping parts K1 and K2 , and K3 and K4 which project toward the end parts of the metal pieces S1 and S2 . The clamping parts K1 and K2 are long enough to come into contact with the metal pieces S1 and S2 and have mutual vertical intervals Sc adjusted by a position varying means 12. The vertical intervals are adjusted in consideration of the quantity of variation in vertical interval between the clamping parts K1 and K2 , and K3 and K4 with loads placed on the clamp parts 10a and 10b, and 11a and 11b, the quantity of variation in vertical interval between the clamping parts K1 and K2 , and K3 and K4 at the end parts of the metal pieces S1 and S2 , etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining metal pieces suitable for continuously hot rolling several to several tens of metal pieces such as sheet bars, slabs, billets or blooms, and an apparatus therefor. It is about.

[0002]

2. Description of the Related Art Conventionally, in a hot rolling line using metal pieces such as steel, aluminum or copper, each steel piece to be rolled is heated, rough-rolled and finish-rolled to a predetermined thickness. Although it was finished into a plate material, such a rolling method inevitably causes stoppage of the line due to defective biting of the rolled material in finish rolling, and also due to defective shape of the front end portion and the rear end portion of the material. The yield reduction also had a significant disadvantage.

For this reason, recently, by using the equipment shown in FIG. 1, the metal pieces to be rolled prior to the finish rolling are continuously fed to the hot rolling line where the leading and trailing ends thereof are joined and rolled. The so-called endless rolling has come to be carried out, and literatures on this point are, for example, JP-A-57-109504 and JP-A-
Reference is made to JP-A-57-137008 and JP-A-62-234679.

In carrying out endless rolling,
Metal piece S rolled up through the rough rolling machine 1₁, S_TwoRewind
While rewinding by the squeezing machine 2 at any time, metal pieces
S₁, S _TwoEach end of the cutting device 3 (drum shear
-, Etc.), and then the preceding metal piece S₁Rear end and rear
Row metal piece S_TwoPlaced with a small gap between the tip and
While transporting so that
Plate thickness with movable clamps 5a and 5b of joining device 4
Clamping support in the same direction, and in that state directly above the planned joint.
An induction heating inder located at least directly underneath
While inductively heating with a doctor 6, or induction heating
After that, pressing means (not shown, clamps 5a, 5b
Both can be moved so that they are close to each other)
Scale metal pieces by moving, pressing and joining each other
Finisher rolling mill 8 (F₁, F_Two, F_ThreeLead to ---)
It has been customary to finish the plate material to a predetermined thickness.

By the way, in the hot rolling of a metal piece that has undergone such a process, there is a high degree of precision in abutting the metal pieces (it is better that there is no vertical or horizontal misalignment).
However, when a metal piece is cut, a crop shear such as a drum shear is used in order to improve the work efficiency, so that the end portion of the crop shears upward or downward as shown in FIG. 3a and 3b, the substantial joining area in the plate thickness direction decreases during so-called joining, so-called misalignment occurs, and during the finish rolling process following the joining process, the joining part becomes the base metal as shown in FIG. It collapsed and this was the cause of the plate breakage during rolling.

In order to avoid the breakage of the plate during the finish rolling, the region from the trailing end of the preceding metal piece S _{1 to} the leading end of the trailing metal piece S ₂ is sandwiched by the sandwiching portion e ₁ as shown in FIG. , a proposal has been made for clamping by a clamp 5a having e ₂ (see PCT / JP94 / 00968, International Publication WO94 / 29040), whereby the upper and lower sides caused by the warp generated when the metal piece is cut It has become possible to significantly reduce the deviation (mismatch).

[0007]

However, in this method, a load is applied to correct the warp caused by the cutting of the end portion of the metal piece during the pressing and supporting, so that the holding portion as shown in FIG. Also, it is unavoidable that the clamp part elastically deforms, and the misalignment has not been completely eliminated,
In particular, in the case of targeting a thin finished plate, it is the current situation that the plate often breaks during rolling. By the way, the permissible misalignment d (see Fig. 3b) after joining to prevent plate breakage during finish rolling varies depending on the finish thickness, but the finish plate thickness is 1.5 mm.
About 10% or less of the plate thickness is preferable, and about 1.0 mm is preferably about 5% or less of the plate thickness.

An object of the present invention is to propose a joining method and an apparatus therefor capable of solving the above conventional problems.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a rear end portion of a preceding metal piece and a leading end portion of a trailing metal piece are cut, respectively, and a clamp portion for sandwiching the metal piece vertically and a metal portion connected to the clamp portion. The front and rear ends of each metal piece are clamped and supported in the thickness direction by a pair of vertically sandwiching portions extending toward the end of the strip, and then heated and pressed against each other along the line direction. A method for joining metal pieces in continuous hot rolling, which comprises adjusting the vertical spacing of the sandwiching portions before joining.

In the above method, for the vertical distance between the sandwiching portions, the sandwiching pressure load at the sandwiching portion is obtained from the warp amount at the end portion of the metal piece, and the sandwiching portion is based on this load or under the sandwiching pressure support of the metal piece. The clamping load that acts on is detected and adjusted based on this load.

Further, according to the present invention, the rear end portion of the preceding metal piece and the leading end portion of the trailing metal piece are respectively cut, and then the clamp portion for sandwiching the metal piece vertically and the end portion of the metal piece connected to this clamp portion are cut. When the front and rear end portions of each metal piece are sandwiched and supported in the thickness direction by the sandwiching portions that extend vertically toward each other and are heated and then pressed against each other along the line direction to join them, The amount of change in the vertical spacing of the sandwiching part due to the load that the clamp receives, the amount of change in the vertical spacing of the sandwiching part at the end of the metal piece, and the change in the vertical spacing of the sandwiching part due to the load received by the clamp when pressing the metal piece. A method for joining metal pieces in continuous hot rolling, characterized in that the vertical distance between the sandwiching portions is adjusted in consideration of the amount.

According to the present invention, the increase amount of the vertical interval of the sandwiching portion is predicted from the clamp force at the clamp portion and the set value or the detected value of the width dimension of the preceding metal piece and the trailing metal piece, and the vertical amount is increased or decreased based on the predicted value. The distance can be adjusted, but the amount of increase in the vertical spacing of the sandwiching part of the metal piece is predicted from the pressing force when pressing the metal piece and the set value or detection value of the width dimension of the preceding metal piece and the trailing metal piece. You may make it adjust. Further, in the present invention, after cutting the trailing end of the preceding metal piece and the leading end of the trailing metal piece, respectively, the amount of warp of each metal piece is detected, and the load necessary to correct it from this amount of warp is determined. Predict and adjust the vertical spacing of the sandwiching part from this predicted value, or adjust the vertical displacement of the sandwiching part by detecting the load or opening increase amount generated in the sandwiching part. It is also possible to grasp the amount of increase in the interval and adjust the vertical interval of the sandwiching portion based on this.

Further, according to the present invention, a heating means for heating and raising the temperature of the end of the metal piece and a pair of upper and lower metal pieces sandwiching the leading metal piece and the trailing metal piece in the thickness direction in the vicinity of their respective end areas are formed. And at least one of the preceding metal piece and the trailing metal piece toward the other, and pressing means for moving and pressing at least one of the leading metal piece and the trailing metal piece. Is a metal piece joining device, wherein the holding part has position changing means for adjusting the distance between the upper and lower holding parts. In this device, the holding part is a metal piece. It is particularly advantageous to use a plurality of blocks which are divided along the width direction and whose upper and lower intervals can be independently adjusted.

In the joining apparatus having the above construction, as the heating means, an inductor for induction heating (iron core + coil) having a pair of magnetic poles sandwiching a metal piece in the thickness direction, or direct butt welding for flash butt welding is used. , Gas burner or laser can be applied. Further, as the pressing means, a hydraulic cylinder (hydraulic cylinder) connected to the clamp portion or a link mechanism can be used.

The position changing means comprises a combination of a connecting tool (pivot pin or the like) for connecting the holding part to the clamp part in a swingable manner and a hydraulic cylinder, or moving the holding part up and down. A guide including a guide and a hydraulic cylinder that moves the holding portion along the guide can be applied.

FIGS. 7 (a) and 7 (b) show an example of a concrete structure of a main part of a joining apparatus suitable for use in the present invention. Reference numeral 9 in the figure is an inductor for heating and heating the ends of the metal pieces S ₁ and S ₂ , respectively, 10a, 10b, 11a,
11b is a clamping unit comprising a pair in upper and lower sandwiching the thickness direction near the edge regions of the metal strip S _1, S _2, the clamp portion 10a, 10b, 11a, 11b are metal strips S _1, S ₂ Clamping parts K ₁ , K ₂ , K ₃ , K ₄ (p
Is an insulating material, of which the sandwiching portions K ₁ and K ₂ have such a length that they are in contact with each other across the metal pieces S ₁ and S _{2 in} this example, and the vertical spacing S _c to (S _c −δ
The position changing means 12 is provided so that the mutual vertical spacing is S _c when the clamping load is applied.

Clamping portions 10a, 10b, 11 of the joining device 4 which is rewound by the rewinding machine 2 and is moved in accordance with the transportation of the metal piece after the end of the metal piece has been cut.
The ends of the metal pieces S ₁ and S ₂ are clamped and supported by a and 11b (a gap of several mm to several cm is formed between the metal pieces at the time of positioning) for positioning, and then the inductor 9
Although a high-frequency current is applied to the parts to heat them, heat them up, and further press them to join them, when the metal pieces S ₁ and S ₂ are positioned, the clamp parts 10a to 11b are simply clamped to support the clamp parts. It is not possible to completely eliminate the warp that occurs when cutting is performed due to elastic deformation of the sandwiching portion. Therefore, in the present invention, the clamp portion 10a
Prior to the pinching support by 11b, for example, the position changing means 12
By adjusting the thickness of the liner 12a, at least one of the sandwiching portions K ₁ and K ₂ is tilted to change the mutual spacing (the mutual spacing is narrowed by the amount of elastic deformation of the clamp portion or the sandwiching portion).
Then, try to eliminate the warp at the end of the metal piece.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a preceding metal piece is used.
The back end and the end of the trailing metal piece are separated by a space S _cSandwich
Clamping force to correct warpage of metal piece when pressure supporting
Elastic deformation of clamps and clamps when a load is applied
The mutual interval of the sandwiching parts is narrowed by δS.
Here, δS will be referred to as an opening adjustment amount, for example.
Knife K₁, K_TwoLoad W and clamping part K₁, K_Two
If there is a proportional relationship with δS at
The quantity δS can be calculated by the following equation.

ΔS = W / M --- (1) M: proportional constant

Further, in the case of a plate material having a sandwiching load per unit width of W _f and a width dimension of B, δ
S can be obtained.

ΔS = W _f · B / M --- (2)

By thus reducing the opening amount (mutual distance), the holding portion K is acted upon when a pressing load is applied.
The mutual distance between ₁ and K _{2 and} the mutual distance between the clamp portions 10a and 10b become equal to each other, and the misalignment that causes the breakage of the plate material during rolling is suppressed.

In the example shown in FIG. 7 above, the holding portion K₁, K_Two
The preceding metal piece S₁From behind metal piece S _TwoHas a length that spans
These holding parts K as₁, K_TwoThe clamp part
By tilting with respect to 10a, 10b, the space S_cTones
I tried to adjust it, but the clamping part K₁~ K_FourAre equivalent
It is assumed that each metal piece has a certain length as shown in FIG.
K for clamping support_Three, K_FourAlso equivalent position change hand
Place step 12.

The position changing means 12 for adjusting the mutual spacing of the sandwiching portions K ₁ , K ₂ or K ₃ , K ₄ as shown in FIG. 7 is as shown in FIGS. 9 to 11. It may be.

FIG. 9 shows a plate 12b having rails (not shown) as guides extending vertically in the main body of the clamp portion.
And the liner 12 is provided between the plate 12b and the holding part by mounting the holding part on the rail of the plate 12b so that the holding part can run.
10 has a structure for adjusting the mutual gap between the upper and lower holding portions by inserting a. In FIG. 10, an opening adjuster 12c such as a hydraulic cylinder is provided in place of the liner 12a in FIG. The structure is such that the clamping unit is moved up and down by the degree adjuster 12c to adjust the mutual spacing,
Further, in FIG. 11, one end of the plate 12b and the holding portion is provided with a pivot pin 12
This is a structure in which the mutual intervals are adjusted by swingably connecting via d and swinging the holding portion by the opening degree adjuster 12c, and almost the same effect can be obtained in any position changing means 12. However, the invention is not limited to only these examples.

Although the clamp portion differs depending on its structure, it is desirable to have a structure corresponding to the case where the amount of change in the opening in the plate width direction is different.

In the joining device equipped with the position changing means 12 having a structure for inserting the liner 12a as shown in FIGS. 7 to 9, it is not possible to adjust the spacing corresponding to the size (plate thickness) of various plate materials. Therefore, it is preferable to set in advance so as to correspond to the pinching load of the plate material in which the misalignment is a problem in the manufacturing range.

That is, the plate material which requires the highest strength at the joint portion in finish rolling is generally a thin material having a narrow width.
The opening to completely correct such materials
Adjust the (pitch of the clamp).

By the way, when the clamping load is set in advance as described above and a larger load is required,
That is, when the width of the metal piece is wide, when the plate thickness of the metal piece fluctuates toward the thick side, or when the warp of the metal piece fluctuates toward the large side, a misalignment occurs. In order to prevent misregistration for all of these, the opening of the holding portion is set to the opening δS _max for the metal piece requiring the maximum load W _max in the manufacturing range, and all the metal pieces are opened. It suffices to apply a clamping pressure so that the clamping load is W _max . In this case, the sandwiching part is suitable for all metal pieces.
The maximum clamping pressure W _max always acts, and the maximum opening δS
_{Since it reaches the maximum value} , the sandwiching portion requires sufficient fatigue strength. In particular, when heating a metal piece by high frequency heating, it is desirable to reduce the size between heating devices as much as possible, and the size of the sandwiching part is also restricted.

In such a case, it is desirable to apply the joining device provided with the position changing means 12 having the structure as shown in FIGS.

The clamping load of a metal piece such as a warped sheet bar varies depending on the amount of warp d and the radius of curvature r shown in FIG. 12, in addition to the plate width and plate thickness, and especially the curvature of the tip. Depending on the difference in radius, as shown in FIG. 13, the pinching load required to correct the warp of the end portion may vary greatly.

The plate width and plate thickness of the metal piece can be grasped by the rough rolling record, but the warp amount and the radius of curvature due to the cutting of the end portion are determined by the blade clearance of the cutting device, the conveying speed of the metal piece and the plate material in the rolling process. It changes even when there is a difference in speed.

Therefore, more specifically, as shown in FIG. 14, a detector 13 is installed on the output side of the cutting device 3, and the warp amount and the warp amount derived from the value detected by this detector (distance meter, etc.) 13 and The calculator 14 calculates the clamping load from the radius of curvature and the plate width and plate thickness, and the interval between the clamping parts for that load.
The amount of increase in (opening) is estimated, and the opening adjuster 12c in the position changing means 12 is operated to compensate for the increase, and the opening of the holding portion is adjusted narrow. The opening controller 12c is composed of, for example, a hydraulic cylinder and a scale for measuring an oil column.

Further, as shown in FIG. 15, the opening controller 12c
A load detector 15 is arranged between the clamping unit and the clamping unit to clamp and support the metal piece and at the same time detect the clamping load and calculate the increase amount of the opening of the clamping unit with respect to the clamping load value at that time. The misalignment can also be suppressed by estimating with the device 16 and narrowing the opening by the opening adjuster 12c by that amount. In addition, the detector 13 and the calculator 14 as shown in FIG.
The misalignment can be suppressed also by adjusting the configuration as shown in FIG.

It should be noted that if there is an error in the estimation of the clamping pressure and the vertical opening of the clamping portion, it is impossible to prevent misalignment. Therefore, the misalignment amount is detected after the metal pieces are joined,
It is desirable to modify the prediction calculation.

In the method of joining metal pieces as described above, although depending on the structure of the clamp, as shown in FIG. 16, the position of the point of application of the clamping force P _{c and} the force W received from the steel piece by the clamping portion are obtained. _If the point of action of _c is deviated in the longitudinal direction of the metal piece, a moment is generated in the sandwiching parts k ₁ and k ₂ when the metal piece is clamped and supported, and it is also affected by the pressing degree of the metal piece. Therefore, it cannot be said that the vertical distance does not change.

To deal with such a problem, FIG. 17 (a)
Load W applied to the clamping part as shown in ₁(Warp of metal pieces
Straightening load P₁), The force W applied to the clamp part_cAnd press
Power W _UAdjust the vertical spacing of the clamps by the effect of. sand
That is, the vertical distance between the clamps due to the load that the clamp receives.
Change amount and the force received by the clamping part from the end of the metal piece
The amount of change in the vertical spacing of the clamps and
The amount of change in the vertical spacing of the clamps due to the load received by the ramp
In consideration of the
Adjust the vertical spacing of.

Here, for example, ΔS ₁ = k ₁ between the load W ₁ applied to the sandwiching portion, the clamping force W _c , the pressing force W _U and the change amount (opening amount) ΔS ₁ of the vertical interval of the sandwiching portion. If there is a relationship of * W ₁ + k _c * W _c + k _U * W _U --- (3), ΔS ₁ = k ₁ * p for the straightening load per unit width p _f and the width B metal piece. _{f * B + k c * W} c + k U * W U --- (4) by opening amount obtained by reducing the vertical interval. As a result, the vertical distance between the sandwiching portions and the opening degree of the clamp portion become the same, and the misalignment at the joint portion is extremely reduced as shown in FIG. 17 (b).

SUS304, titanium, tungsten or the like can be applied as a material forming the sandwiching portions K _{1 to} K ₄ .

In the case of adopting an induction heating method using an inductor for heating the metal pieces, if the metal pieces are clamped and supported across both metal pieces, an induced current flows between the metal pieces through the sandwiching portion and the metal pieces Since a situation in which it is not possible to effectively heat and raise the temperature of the end portion is assumed, the sandwiching portion K ₁
It is important to install the insulating material p between K ₄ and the metal pieces S ₁ and S ₂ .

As the insulating material, a metal piece whose temperature becomes high and a part thereof is melted is present, so that it is preferable to use ceramics (silicon nitride etc.) having heat resistance, thermal shock resistance and hot strength. .

It is preferable that the sandwiching portions K _{1 to} K _{4 have} a planar shape in which the comb-shaped notches are formed at intervals along the width direction of the metal piece. The same effect can be obtained even if the metal piece is constrained in the widthwise direction, but especially when an inductor that performs induction heating is used as the heating device, an induction current is generated in this sandwiching part. This is because not only the heating efficiency is lowered by being heated together with the flowing metal piece, but also the holding part may be damaged or welded to the metal piece.

In the case of using one having a notch cut out like a comb tooth as the sandwiching portion, no current flows at the time of induction heating, but the current is a circulating current in the comb tooth. Then, they interfere with each other to cancel each other and the current density becomes small, so that the generation of Joule heat is small and the heating degree becomes small, which is advantageous for improving the heating efficiency.

In the structure shown in FIG. 7, the holding parts K ₃ , K
_Since the magnetic pole of the inductor 9 is somewhat separated from the magnetic flux of the inductor 9, the influence of induction heating is not so great, and it is not necessary to provide a cutout portion for such a sandwiching portion, but the magnetic flux of the inductor is limited to the sandwiching portion. In the case where it extends to the clamp portion instead, it is preferable to form a cutout portion that reaches the clamp portion.

Further, as shown in the section A--A of FIG. 3 (a) in FIG. 18, the vertical spacing may vary in the width direction of the metal piece depending on the arrangement position of the metal piece or how the clamping force is applied. In such a case, the sandwiching portion may be divided along the width direction of the metal piece, and the sandwiching portion may be configured into a plurality of blocks in which the mutual intervals can be independently adjusted to adjust the vertical interval.

In this case, the relationship between the clamping force and the amount of change in the distance between the holding portions is obtained in advance, and the vertical distance in the width direction is adjusted according to the actual clamping force.

The relationship between the amount of change in the vertical interval in the width direction of the sandwiching portion and the clamping force varies depending on the width dimension of the metal piece. This is because the load distribution on the clamp differs depending on the width of the metal piece. is there. Therefore, it is important to adjust the spacing according to the width dimension of the metal piece.

However, if the vertical spacing of the sandwiching portion cannot be adjusted online, the vertical spacing of each block cannot be set to the optimum spacing for correcting the warp, but each block must be within the proper range of the straightening load. It is desirable to adjust the spacing. Further, with respect to the pressing force as well, it is desirable to adjust the gap in consideration of the difference in the vertical direction of the metal pieces in the width direction as in the case of the clamping force.

[0049]

Example Continuous hot rolling was carried out in the following manner using the hot rolling equipment having the arrangement as shown in FIG.

Comparative Example Both the leading metal piece and the trailing metal piece had a width of 1600 mm and a thickness of:
A 30 mm sheet bar (steel type: low carbon steel) was used. Then, first, the trailing end portion of the preceding sheet bar and the leading end portion of the following sheet bar were cut by a cutting device. As shown in FIG. 12, the shape of the sheet bar after cutting is such that the preceding sheet bar is warped and the following sheet bar is warped, and the curvature radius r of the warp near the shear plane at the rear end of the preceding sheet bar is about 2000 mm. ,
The warp amount d was about 30 mm and the warp length L was about 400 mm. The radius of curvature r at the leading end of the trailing sheet bar was about 1000 mm, the amount of warp d was about 50 mm, and the warp length L was about 600 mm.

Next, the rear end of the preceding sheet bar and the front end of the following sheet bar are aligned with predetermined positions of the joining device,
The sheet bar was clamped and supported by the conventional clamp part shown in (4), and in that state, the sheet bar was heated by high frequency induction heating for 10 seconds to melt the end faces and then press processing was performed to join the two sheet bars. At this time, the load applied to the sandwiching part is about 40 tonf, the spacing between the sandwiching parts is about 2.5 mm larger than the vertical spacing between the clamp parts, and the spacing is almost equal to the spacing after the joining is completed. There was a misalignment of about 2.5 mm.

Then, the joined sheet bars were subjected to finish rolling to form a hot rolled sheet having a thickness of 1.2 to 5 mm. Set value of tension between stands front at 0.5 ~1kgf / mm ^2, and a 1 to 1.5 kgf / mm ² at a later stage. As a result, the finished thickness is 1.
When the thickness is 5 mm or less, plate breakage frequently occurs at the joint between the stands at the post-finishing stage.
The result was below.

Example 1 First, the joining device having the structure shown in FIG. 7 is arranged in the rolling equipment of FIG. (Opening degree) was set narrower by δS as the opening adjustment amount with respect to the interval of the clamp portion. The opening adjustment amount δS was changed in the range of 1 to 5 mm. The cutting method is the same as the comparative example, the radius of curvature of the preceding sheet bar and the following sheet bar after cutting, the amount of warp, the length of the warp is almost the same as the comparative example, the leading material warp, trailing material Was warped.

Next, the rear end of the preceding sheet bar and the front end of the following sheet bar were made to coincide with predetermined positions of the joining device, and clamped and supported by the clamp part together with the clamp part having a preset opening. Then, in that state, the sheet bar was heated by high frequency induction heating for 10 seconds to melt the end faces and then subjected to a pressing treatment to join the two sheet bars. At this time, the amount of misalignment of the joint after the joining is shown in Fig. 19 (a), and the load applied to the sandwiching portion is shown in Fig. 19 (b).

From the results of FIG. 19 (a), it was confirmed that when the opening adjustment amount δS in the sandwiching portion is 2 mm or more, the misalignment is suppressed to 1.5 mm or less, which is 5% of the seat bar thickness. The sheet bar joined with the adjustment amount δS of 2 mm was subjected to finish rolling to obtain a hot rolled sheet having a thickness of 1.2 to 5 mm. Set value of tension between stands front at 0.5 ~1kgf / mm ^2, and a 1 to 1.5 kgf / mm ² at a later stage. As a result, even when the thickness was 1.2 mm, there was no breakage of the plate as long as 100 rollings were carried out.

Example 2 Next, joining was carried out by using the same sheet bar as in the comparative example in a hot rolling facility equipped with a joining apparatus having a structure as shown in FIG. The amount of warp after cutting was detected by a detector as shown in FIG. 14, and the position changing means changed the position of the sandwiching portion in accordance with the detected value to adjust the opening degree.

The cutting of the sheet bar is the same as in the comparative example,
After cutting, the preceding sheet bar was warped and the trailing sheet bar was warped, and the curvature radius of the warping was larger in the trailing sheet bar. The curvature radii of the warps at the ends of the leading and trailing seat bars detected by the warp amount detector varied as shown in Fig. 20 (a). Based on the radii of curvature of each seat bar, the clamping pressure value is estimated from the relationship shown in Fig. 13 so that the misalignment at the time of joining is 1 mm or less, and as shown in Fig. 20 (b), the clamping force is opened. The degree adjustment amount δS was determined.

Then, after aligning the rear end of the preceding sheet bar and the front end of the following sheet bar with the predetermined position of the joining device, the clamping is supported by the clamping part together with the clamping part, and the seat bar is heated by high-frequency induction heating. After heating for 2 seconds to melt the end faces, a pressing process was performed to join both steel pieces.

As a result, it was confirmed that the misalignment amount was suppressed to about 1 mm as shown in FIG. 20 (b), and these sheet bars were subjected to finish rolling under the same tension conditions as in Example 1. 100 hot-rolled sheets with a thickness of 1.2 mm were finished, but no fracture of the sheet was observed.

Example 3 The same joining of sheet bars as in the comparative example was performed by using the joining apparatus having the sandwiching portion having the structure as shown in FIG.
At this time, the pinching load was detected by a load detector as shown in FIG. 15, and the opening degree of the holding section was adjusted by the opening degree adjuster. Prior to this, when the relationship between the load W [tf] applied to the support member interval and the change amount δS [mm] of the opening was investigated, the load 10
Above tf, the following linear relationship was obtained.

ΔS = (W / 25) +0.8 ---- (5)

In this embodiment, first, after cutting the sheet bar, the trailing edge of the preceding sheet bar and the leading edge of the following sheet bar are aligned with the predetermined positions of the joining device, and the target misalignment amount d _{mo k} = 1 mm is set. As a target, the opening degree of the sandwiching portion was adjusted using the detected sandwiching portion load. That is, based on the load W detected by the opening calculator, the opening adjustment amount δ
S was determined, and the opening degree adjuster was adjusted to obtain that value.

_ΔS = (W / 25) + 0.8−d _moK ---- (6)

While continuing this state, the sheet bar was heated by high frequency induction heating for 10 seconds to melt the end faces and then subjected to a pressing treatment to join the steel pieces and finish-rolling the joined sheet bar. To a hot rolled sheet with a thickness of 1.2 to 5 mm. The set value of the tension between the stands is 0.5-1kg in the previous stage.
f / mm ^2, and a 1 to 1.5 1 kgf / mm ² at a later stage. As a result, even when the thickness was 1.2 mm, no sheet breakage occurred as long as 100 rollings were carried out.

Example 4 In order to join using a sheet bar having the same size as that of the comparative example, prior to the joining, when the width B of the sheet bar is 1600 mm, the force W _c on the clamp portion and the pressing force W are applied. _When the relationship between _U and the warp straightening load per unit width p _f and the amount of change ΔS in the vertical spacing of the sandwiching parts was investigated for each sandwiching part, when the load was 10 ton f or more, the following linear relationship was found. I found out. ΔS = k _f * p _f + k _c * W _c + k _U * W _U --- (7) k _f , k _c , and k _U are constants determined for each sandwiching part.

The cutting method was the same as that of the comparative example, and the shape of the sheet bar after cutting was such that the preceding sheet bar was warped and the following sheet bar was warped, but the sheet detected by the warp detector. The radius of curvature of the warp at the bar end is shown in Fig. 21.
As shown in (a), it varied depending on each seat bar. Based on the radius of curvature of each seat bar, the correction load value is estimated so that the misalignment of each seat bar is about 1 mm using the relationship of FIG. 13, and the correction load estimated value and the clamp force and the pressing value are set. The value was used to determine the adjustment amount of the vertical interval of the sandwiching part from the above equation (7).

After that, the rear end of the preceding sheet bar and the front end of the following sheet bar are aligned with the predetermined position of the joining device, and the opening degree of the nipping portion is adjusted by the above adjustment amount to support nipping.
In this state, the sheet bars were heated by high frequency induction heating for 10 seconds to melt the end faces of the portions to be joined, and then the sheet bars were pressed against each other for joining.

As a result, as shown in FIG. 21 (b), the amount of misalignment generated during joining was suppressed to about 1 mm. Also,
When this sheet bar was finish-rolled into a hot-rolled sheet having a thickness of 1.2 mm, there was no breakage of the sheet during rolling.

Example 5 The joining was performed using a sheet bar having the same size as that of the comparative example. When joining the sheet bars, the clamping force, the pressing force and the load generated in the nipping part at the time of nipping support, heating and pressing by the joining device are detected, and the nipping is performed by the above equation (7) using the detected values. The amount of change in the vertical distance between the parts was estimated, and the interval was adjusted so that the amount of change disappeared. The radius of curvature of the end portion of the seat bar detected by the warp detector was as shown in Fig. 22 (a).

The amount of misalignment after joining the sheet bars is
As shown in 22 (b), it can be suppressed to about 1 mm, and when hot rolled with a thickness of 1.2 mm by finish rolling,
No breakage of the plate was observed during rolling.

Example 6 The joining was performed using a sheet bar having the same size as that of the comparative example. When joining sheet bars, joining equipment
(The clamping part is composed of blocks that are divided in the width direction of the seat bar and can be adjusted independently of each other.) (6 places for each mm) is detected by the detector, and the opening adjuster 12c in FIG. 11 is operated by using the detected value so that the vertical interval of the sandwiching part at the detection position becomes a constant interval. The vertical interval was adjusted with the sandwiching part. Here, the curvature radius of the warp of the end portion of the seat bar detected by the warp detector is as shown in FIG. 23 (a).

FIG. 23 (b) shows the adjustment amount of the opening degree and the misalignment amount for each sheet bar. The misalignment amount of the sheet bar is suppressed to about 1 mm, and the thickness of 1.2 bar is obtained by finish rolling. Even when the hot rolled sheet of mm was finished, the sheet did not break.

[0073]

As described above, according to the present invention,
It becomes possible to suppress the occurrence of misalignment by adjusting the vertical spacing of the sandwiching parts that sandwich both metal piece ends when joining the metal pieces, and the fracture of the plate between the stands during rolling due to this misalignment Since it does not exist, continuous hot rolling with high productivity can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a continuous hot rolling facility.

FIG. 2 is a diagram showing a shape of a sheet bar after cutting.

FIG. 3A and FIG. 3B are explanatory diagrams of a procedure for joining metal pieces according to a conventional method.

FIG. 4 is a diagram showing a state in which a joint portion is collapsed into a base material by rolling.

FIG. 5 is an explanatory view of a procedure for joining metal pieces according to a conventional method.

FIG. 6 is an explanatory view of a procedure for joining metal pieces according to a conventional method.

7A and 7B are configuration explanatory views of the joining device according to the present invention.

FIG. 8 is a structural explanatory view of a joining device according to the present invention.

FIG. 9 is a view showing another example of the joining device according to the present invention.

FIG. 10 is a view showing another example of the joining device according to the present invention.

FIG. 11 is a view showing another example of the joining device according to the present invention.

FIG. 12 is an explanatory diagram of a cutting state of a metal piece.

FIG. 13 is a graph showing the relationship between the pinching load per unit width required to correct the warp and the radius of curvature of the warp.

FIG. 14 is an explanatory diagram of a control procedure according to the present invention for adjusting the opening degree of the holding section.

FIG. 15 is another explanatory view of the control procedure according to the present invention for adjusting the opening degree of the sandwiching portion.

FIG. 16 is a diagram showing a state in which a point where a clamp force acts on a clamp portion is deviated.

17A and 17B are explanatory views in the case of adjusting the vertical interval of the sandwiching unit according to the present invention.

FIG. 18 is a diagram showing a cross section taken along the line AA of FIG. 3.

19A is a graph showing the relationship between misregistration amount and opening adjustment amount, and FIG. 19B is a graph showing the relationship between load applied to the sandwiching portion and opening adjustment amount.

FIG. 20 a is a graph in which the radius of curvature of the warp is investigated,
b is a graph in which the opening adjustment amount and the misalignment amount are investigated.

FIG. 21a is a graph in which the radius of curvature of the warp is investigated,
b is a graph in which the opening adjustment amount and the misalignment amount are investigated.

FIG. 22a is a graph in which the radius of curvature of the warp is examined,
b is a graph in which the opening adjustment amount and the misalignment amount are investigated.

FIG. 23 a is a graph in which the radius of curvature of the warp is investigated,
b is a graph in which the opening adjustment amount and the misalignment amount are investigated.

[Explanation of symbols]

1 rough rolling mill 2 unwinding machine 3 cutting device 4 joining device 5a clamp 5b clamp 6 inductor 7 scale breaker 8 finishing rolling mill 9 inductor 10a clamp 10b clamp 11a clamp 11b clamp 12 position change means 12a liner 12b plate 12c opening adjuster 12d Pivot pin 13 Detector 14 Operator 15 Load detector 16 Operator S ₁ Metal piece S ₂ Metal piece K _{1 to} K ₄ Clamping part P Insulation material W Load _Sc interval

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiro Takebayashi 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Technical Research Institute, Kawasaki Steel Co., Ltd. (72) Inventor Yoshiki Tamai 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba (72) Inventor Toshio Imae, 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Technical Research Institute, Kawasaki Steel (72) Kunio Isobe, Kawasaki-machi, Chuo-ku, Chiba (72) Inventor Hideyuki Nikaido, No. 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba (72) Inside Chiba Works, Kawasaki Steel (72) Inventor, Shigeru Isoyama No. 1 Kawasaki-cho, Chuo-ku, Chiba-shi Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Kazuo Morimoto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries In Hiroshima Research Institute Co., Ltd. (72) Kunio Miyamoto, 4-6 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Works (72) Inventor Akio Kuroda 4-6, Kannon Shinmachi, Nishi-ku, Hiroshima Prefecture No.22 Mitsubishi Heavy Industries Hiroshima Works

Claims (6)

[Claims] 1. A rear end portion of a preceding metal piece and a front end portion of a trailing metal piece are respectively cut, and then a clamp portion for sandwiching the metal piece vertically and a connecting portion to the clamp portion and extending toward an end portion of the metal piece. When the front and rear ends of each metal piece are sandwiched and supported in the thickness direction by the sandwiching parts that are paired up and down, heating and pressing are performed along the line direction to bond them together. A method for joining metal pieces in continuous hot rolling, characterized by adjusting a gap. 2. The joining method according to claim 1, wherein a clamping pressure load on the sandwiching portion is obtained from a warp amount at an end portion of the metal piece, and the vertical interval of the sandwiching portion is adjusted based on the load. 3. The joining method according to claim 1, wherein a clamping pressure load acting on the clamping portion is detected while the metal piece is clamped and supported, and the vertical distance between the clamping portions is adjusted based on this load. 4. The front end portion of the preceding metal piece and the front end portion of the trailing metal piece are cut, respectively, and then a clamp portion for sandwiching the metal piece up and down is connected to the clamp portion and extends toward the end portion of the metal piece. The clamp part receives the front end and the rear end of each metal piece by sandwiching them in the thickness direction by the sandwiching parts that are paired up and down, and then heating and pressing them together along the line direction to join them. The amount of change in the vertical spacing of the sandwiching portion due to the load, the amount of change in the vertical spacing of the sandwiching portion due to the load received by the sandwiching portion, and the amount of change in the vertical spacing of the sandwiching portion due to the pressing load received by the clamp portion when pressing the metal piece. A method for joining metal pieces in continuous hot rolling, characterized in that the vertical spacing of the sandwiching portions is adjusted based on the above. 5. A heating means for heating and raising the temperature of the end of the metal piece and at least two pairs of upper and lower portions sandwiching the preceding metal piece and the following metal piece in the thickness direction in the vicinity of their respective end areas. And a pressing unit that moves and presses at least one of the preceding metal piece and the following metal piece toward the other, and each clamp section has a sandwiching portion that protrudes toward the end of the metal piece. However, the sandwiching device has a position changing device that adjusts a space between the sandwiching parts in the vertical direction. 6. The joining apparatus according to claim 5, wherein the holding portion is divided along the width direction of the metal piece, and comprises a plurality of blocks each of which is capable of independently adjusting the mutual distance.