JP5786882B2 - Thick steel plate shearing machine shear blade - Google Patents

Description

  The present invention relates to a shearing blade of a thick steel plate shearing machine.

  Thick steel plates rolled to a predetermined thickness by hot rolling (hereinafter also referred to as steel plates) are measured after cooling in a cooling bed, and the measured thick steel plates are cut to a predetermined width and length. . This cutting is performed by shearing using a shearing machine or gas cutting. Normally, a thick steel plate having a thickness of less than about 50 mm is sheared by a shearing machine, and if it exceeds that, gas cutting is performed. The shearing machine includes a crop shear that shears the top and bottom portions of the thick steel plate, a double side shear that shears both ears of the thick steel plate, a slitter that divides the width direction of the thick steel plate into two, and a length direction with a predetermined dimension. There is an end shear or the like that shears, and by passing through a shearing line constituted by these shearing machines, it is sheared into a thick steel plate of a predetermined size.

  Defects on the shearing surface due to the shearing machine include sagging and burrs. If these occur, they cannot be used as products as they are, and they require maintenance such as grinder grinding or recutting, resulting in a decrease in yield and manufacturing costs. Invite the rise. Various proposals have been made for countermeasures against these shear plane defects.

  For example, in Patent Document 1, when cutting a thick steel plate that has been hot-rolled using a shear, a portion A that is a cut-off portion is heated in a portion divided by a cutting line CC ′. At the same time, the product part B is not heated, so cutting is performed with a temperature difference between the parts A and B to prevent the occurrence of shearing at the end of the product part B. A method is disclosed.

  Patent Document 2 discloses a method for shearing a thick steel plate in which the shearing position of the thick steel plate is hardened to a depth of 2 mm and cured and then subjected to shear by applying a shearing blade.

  In Patent Document 3, when the rear end of the steel sheet conveyed on the shear line is cut by a cutting machine such as a split shearing machine in which the lower blade and the upper blade are sequentially provided along the traveling direction of the steel plate, the lower blade A method is disclosed in which the remaining portion of the indefinite shape of the steel sheet remaining on the top is lifted after being attracted and held by a magnet, and then transferred to a packet for removal.

JP-A-6-190627 JP 2009-220201 A JP 2007-253302 A

  The technique described in Patent Document 1 requires equipment for preheating the steel plate end, and the technique described in Patent Document 2 requires quenching equipment for quenching the surface of the steel sheet. Then, it is necessary to install a magnet as an accessory facility, and any of the techniques described in the patent documents has a problem that it is necessary to additionally install a facility other than a shearing machine in the shearing line, resulting in an increase in capital investment costs.

  An object of the present invention is to provide a shearing blade of a thick steel plate shearing machine that can obtain an excellent shearing surface without requiring a large capital investment.

  The inventors have observed the shearing phenomenon of thick steel plates and have found the following. That is, the shearing blade used in the thick steel plate shearing machine is set so as to obtain a good shearing surface by narrowing the gap between the upper and lower blades, and the side surface of the blade is in the entire cross section of the steel plate. It comes to contact. For this reason, any who has occurred on the upper surface of the steel sheet at the first cut is rubbed at the corner of the blade tip as the blade tip rises, and then burr is pressed against the steel sheet surface by the second blade edge. It was found to generate.

  This invention is made | formed based on the said knowledge, The summary is as follows.

  [1] A shearing blade that shears the side surface in the plate width direction of a thick steel plate in the longitudinal direction of the thick steel plate, the shearing blade having a rectangular parallelepiped shape, and contacting the thick steel plate shearing surface at the leading end of the rectangular parallelepiped in the thick steel plate conveyance direction A shear blade of a thick steel plate shearing machine, wherein the edge of the blade is cut into a range of 10 to 300 mm in the longitudinal direction of the thick steel plate, 10 to 20 mm in the width direction of the thick steel plate, and 10 to 100 mm in the thickness direction of the thick steel plate.

  Since the blade edge of the double-sided shear blade of the thick steel plate was cut as in the present invention, the occurrence of burr pressing by shearing was reduced.

It is drawing which shows the side surface of the cutter of a double side shear. It is a figure explaining the cutting direction of a blade edge | tip. It is a figure explaining the generation | occurrence | production situation of a burr | flash.

  The present invention will be described below with reference to the drawings.

  The steel plate width direction side surface in the double side shear is sheared with a 2 m long blade, and the shearing operation is continued while feeding the steel plate forward on the line for each cut. In this shearing operation, the cut portion is somewhat doubled and sheared so that a step does not occur in the longitudinal direction of the steel plate for each cut. Then, burrs may occur in the portion where the shear is doubled.

  The burr pressing generated at the time of shearing by the double side shear is generated when the burr generated at the time of shearing is wound around the steel plate surface.

  The shearing blade of the double side shear has a rectangular parallelepiped shape, and in particular, the corner of the tip of the shearing blade is a right angle (FIG. 1). Here, the rectangular parallelepiped shape has only to have a right corner, and the side does not necessarily have to be a straight line. Further, since the clearance between the upper blade and the lower blade is often set tightly in order to maintain the perpendicularity of the shear surface, the shear blade rises in the first cut when the double side shear is sheared. Sometimes, the corner of the blade tip is rubbed to form burrs, and in the subsequent second cut, the corner of the blade tip presses the burrs against the surface of the steel sheet to form a “burr pusher” (FIG. 3).

  The cutting amount of the edge portion of the blade is 10 to 300 mm in the steel plate longitudinal direction, 10 to 20 mm in the steel plate width direction, and 10 to 100 mm in the steel plate thickness direction (FIG. 2).

  The cut amount is measured starting from the corner portion of the short side surface of the rectangular parallelepiped shear blade.

  The length of 10 to 300 mm in the longitudinal direction of the steel plate is cut at least 10 mm in order to eliminate the corners, and the amount of doubling at the first and second cuts is around 200 mm. 10-20mm in the width direction of the steel plate is cut at least 10mm to eliminate the corners, and if the half of the blade thickness is cut (20mm), the corners of the blade tip will contact the steel plate even if the steel plate is somewhat meandering. Judged not. The range of 10 to 100 mm in the steel sheet thickness direction is cut at least 10 mm in order to eliminate the corners, and the maximum thickness of the steel plate to be sheared is 50 mm, so that the safety is 100 mm.

  A pruning test was conducted using a double side shear on a conventional blade and a blade of the present invention on 4000 steel plates having a plate thickness of 4.5 to 50 mm, a plate width of 1000 to 5500 mm, and a plate length of 6000 to 26500 mm.

  The test results showed that the steel sheet maintenance rate due to burrs was 0.5% when the conventional cutter was used, but can be reduced to 0.09% by using the cutter of the present invention. It was.

Claims (1)

  A shear blade that shears a plate width direction side surface of a thick steel plate in a longitudinal direction of the thick steel plate, the shear blade having a rectangular parallelepiped shape, and a corner of the cutting edge that contacts the thick steel plate shear surface at a front end portion of the rectangular parallelepiped in the thick steel plate conveyance direction A shear blade of a thick steel plate shearing machine, wherein a range of 10 to 300 mm in the longitudinal direction of the thick steel plate, 10 to 20 mm in the width direction of the thick steel plate, and 10 to 100 mm in the thickness direction of the thick steel plate is cut.