Metal working – Plural diverse manufacturing apparatus including means for... – Binding or covering and cutting
Reexamination Certificate
1999-06-07
2001-03-06
Briggs, William (Department: 3722)
Metal working
Plural diverse manufacturing apparatus including means for...
Binding or covering and cutting
C409S140000, C409S258000, C409S275000, C409S298000, C409S300000
Reexamination Certificate
active
06195859
ABSTRACT:
TECHNICAL FIELD
the present invention relates to a method and apparatus for surface cutting of hot-rolled steel products, especially of wide hot-rolled long sheets, and a method and apparatus for surface cutting which are advantageous in removing raised portions (projections) and burrs produced in a joint region by butt joint of semifinished steel products such as sheet bars, slabs, billets, and blooms.
BACKGROUND ART
Regarding the technologies for making a repair of flaws produced on the surfacer of hot-rolled steel products such as sheet bars during the hot rolling process and for removing projections inevitably produced in the joint portion in the continuous hot rolling process in which rolling is carried out by butt joining the tail edge of preceding steel product to the leading edge of following steel product, many proposals have already been made in Unexamined Japanese Patent Publication No. 57-137008, Unexamined Japanese Patent Publication No. 63-160707, Unexamined Japanese Patent Publication No. 5-23706, Unexamined Japanese Patent Publication No. 5-104261, Unexamined Japanese Patent Publication No. 57-91856, Unexamined Japanese Patent Publication No. 53-112593, and so forth.
However, these technologies have disadvantages that there arises a trouble of breaking of a hot-rolled steel product (hereinafter referred simply as to a steel product) in surface-cutting the steel product, and that the improvement in cutting efficiency cannot be achieved because the life of cutting edge is short and quick action cannot be taken when local wear of cutting edge occurs. Also, there remain problems in that it is difficult to adjust a predetermined allowance in cutting a steel product, that the equipment is damaged by the contact of cutting edges which cut a steel product from upside and downside, that chips produced by cutting cannot be disposed well, and that fluttering of steel product occurs during the cutting process.
An object of the present invention is to provide a method and apparatus which can solve all above-described conventional problems occurring in surface cutting of steel products.
DISCLOSURE OF THE INVENTION
1) The present invention provides a surface cutting method for steel products in which in cutting the top and bottom surfaces of a steel product by the rotation of milling cutters holding the steel product therebetween in the thickness direction in the conveying process of the steel product having a joint portion, the cutting resistance determined by the cutting conditions including the type of steel product, the temperature in cutting, and the cut depth is controlled by the adjustment of cut depth, and cutting is performed by making the tension produced on the steel product by the cutting resistance lower than the breaking strength of the joint portion to prevent the breakage of steel product.
2) In the above item 1), a sudden temperature rise of steel product is detected on the input side of milling cutter, the steel product is held between the milling cutter based on the detected signal, and the surfaces of the joint portion including the nearby portion of steel product are cut.
3) In the above item 1), when the steel product running direction and the milling cutter rotating direction on the cut surface are reverse to each other, the adjustment of one-side cut depth t satisfies the following equation (1).
[Note]
t≦&sgr;
b
·(
b−
2
w
)·
T/{
2
S
f
·C·
exp [
A/
(
T
k
+273)]·
b·V
M
/V
C
+2&sgr;
b
·(
b−
2
w
)} (1)
where
t: one-side cut depth (mm)
S
f
: safety factor
&sgr;
b
: strength of joint portion of steel product considering temperature (kgf/mm
2
)
b: width of steel product (mm)
W: one-side unjoined length in the sheet width direction at joint portion of steel product (mm)
T: thickness of steel product (mm)
C: constant determined by the type of steel product (kgf/mm
2
)
A: constant determined by the type of steel product (° C.)
T
k
: temperature of steel product in cutting (° C.)
V
M
: running speed of steel product (mm/s)
V
c
: circumferential speed of milling cutter cutting edge (mm/s)
4) In the above item 1), when the steel product running direction and the milling cutter rotating direction on the cut surface are equal to each other, the adjustment of one-side cut depth t satisfies the following equation (2).
[Note]
t
≦&sgr;
b
·(
b−
2
w
)·
T/{
2
S
f
·C·
exp [
A/
(
T
k
+273)]·
b·V
M
/V
C
} (2)
where
t: one-side cut depth (mm)
S
f
: safety factor
&sgr;
b
: strength of joint portion of steel product considering temperature (kgf/mm
2
)
b: width of steel product (mm)
w: one-side unjoined length in the sheet width direction at joint portion of steel product (mm)
T: thickness of steel product (mm)
C: constant determined by the type of steel product (kgf/mm
2
)
A: constant determined by the type of steel product (° C.)
T
k
: temperature of steel product in cutting (° C.)
V
M
: running speed of steel product (mm/s)
V
C
: circumferential speed of milling cutter cutting edge (mm/s)
5) In the above item 1), at least the cutting edges of a milling cutter are made of a ferrous material, and cooling water is sprayed to the cutting face or flank of the milling cutter at a pressure according to the rotating speed and outside diameter.
6) Also, the present invention provides a surface cutting apparatus for steel products comprising a pair of main shafts which hold a steel product therebetween in the thickness direction and rotate in the direction reverse to each other, and having rotary drums each of which is provided on the main shaft and on which a plurality of disks each of which has cutting edges at the whole outer periphery and fits detachably to the main shaft are arranged.
7) In the above item 6), the disks are so arranged that the phase of cutting edges on the adjacent disks is shifted in the circumferential direction, and the cutting edges are arranged discontinuously in the axial direction (claim 7).
8) In the above item 6), the main shaft is configured so that the disks are fixed to the main shaft by the expansion of shaft diameter.
9) In the above item 6), the main shaft is configured so that the disks are fixed to the main shaft by the expansion of shaft diameter, and has a contracting mechanism for contracting the shaft diameter instantly when an excessive load is applied to the disks.
10) The present invention provides a surface cutting apparatus for steel products for cutting the top and bottom surfaces of a steel product continuously or intermittently by passing the steel product between a pair of rotary drums rotating in the direction reverse to each other, the apparatus having a disk for recognizing gap between drums, which has a diameter larger than that of the rotary drum, at both ends or one end of at least one rotary drum.
11) In the above item 6) or 10), at least one rotary drum is provided with measuring means for measuring wear amount at the tip end of rotary drum to make level adjustment of rotary drum with respect to the steel product.
12) The present invention provides a surface cutting apparatus for steel products for cutting the top and bottom surfaces of a steel product continuously or intermittently by passing the steel product between a pair of rotary drums rotating in the direction reverse to each other, the apparatus having chip discharge means for discharging chips, which are produced by the cutting of steel product by using the rotary drums, for each rotary drum.
13) In the above item 12), flowing water injecting means is provided in the chip discharge means for the rotary drum.
14) The present invention provides a surface cutting apparatus for steel products for cutting the top and bottom surfaces of a steel product continuously or intermittently by passing the steel product between a pair of rotary drums rotating in the direction reverse to each other, the apparatus having a movable sheet passing guide for holding the steel product during the period of time when the steel product advances from the input side to the out
Amagasa Toshiaki
Hayashi Kanji
Hirabayashi Takeshi
Ichikizaki Tetsuo
Isoyama Shigeru
Briggs William
Kawasaki Steel Corporation
Oliff & Berridg,e PLC
LandOfFree
Surface cutting apparatus for hot-rolled steel products does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surface cutting apparatus for hot-rolled steel products, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surface cutting apparatus for hot-rolled steel products will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2521333