JPH0885106A - Production of flaker knife - Google Patents

Abstract

PURPOSE: To obtain a flaker knife which can be used for a long term with little possibility that it may be bent in the width direction thereof even if a ridge surface is ground many times by a method wherein the bevel surface is formed so that a high-speed tool steel sheet surface of a bonded steel sheet serves as a rear blade surface. CONSTITUTION: A ridge surface 11 of a flaker knife 1 made of a bonded steel sheet obtained by brazing a mild steel sheet 21 to a high-speed toll steel sheet 22 is ground at a specific angle α so that a high-speed tool steel surface serves as a rear blade surface 12. The tip of the ridge surface serves as a cutting edge 13. Slots 15 and mounting screw holes 14 are provided in position. For example, one surface of a 2mm thick high-speed tool steel sheet and one surface of a 6mm thick mild steel sheet are ground and brazed to each other to form a bonded steel sheet, and a flaker knife 374mm long ×100mm wide × 5mm thick with a bevel angle α of 36 deg. and a flaker knife 524mm long × 100mm wide × 5mm thick with the bevel angle α of 36 deg. are obtained by grinding the bonded steel sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate-shaped product made by mixing a synthetic resin adhesive with a plant fiber small piece made of wood or the like and pressurizing it at a high temperature, so-called fiber board (hard board or insulation board). The present invention relates to a flaker knife used as a cutting blade of a cutting device for obtaining a small piece of wood or the like as a raw material of the above, which is made into a smaller piece with a chipper or the like, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, Prall has been used as a kind of cutting device for cutting chipped plant fiber pieces into smaller pieces to be used as a raw material for fiber boards.
Mold cutting equipment is used.

As shown schematically in FIGS. 8 and 9, this type of cutting device is provided in front of and behind a casing (not shown) in parallel and with the same axis center with a predetermined distance. Between the two ring-shaped holding plates 2 and 3, dozens of inner faces 4 are tightly attached to the holding plates 2 and 3 in an inscribed state in the same pitch and on the same circumference. It is provided. Segments 5 for fixing a knife holder 6 to which the flaker knife 1 is fixed at a predetermined angle are integrally fixed to the inner face 4. The dozens of flaker knives 1 fixed to the dozens of knife holders 6 are tangential lines of a circle having a predetermined radius as the knife holder 6 is moved back and forth on the mounting surface of the segment 5. Predetermined angle θ with respect to L
And is adjusted and provided so that the cutting edge is located on the circumference of a circle having a predetermined radius. Also,
By the ring-shaped holding plates 2 and 3 provided at the front and rear and the inner face 4 provided at the same pitch and the same posture on the same circumference between the ring-shaped holding plates 2 and 3. On the inner side surrounded by the ring-shaped holding plates 2, 3, an impeller body 8 having a plurality of impeller plates 7 whose tip is adjusted on the circumference of a circle having a predetermined radius is provided. It is provided with the same axis. Then, with a minute clearance provided between the blade edge of the flaker knife 1 and the tip of the impeller plate 7, the chip-like small pieces carried to the tip of the impeller plate 7 by the impeller plate 7 are The ring-shaped holding plate 2, in the direction of being further cut into small pieces by the cutting edge,
3 and the impeller body 8 are rotated at a relatively high speed (some models rotate only the impeller body, and others rotate both the ring-shaped holding plate and the impeller body).

Next, the chip-like small pieces supplied toward the center of the impeller body 8 from a charging port (not shown) provided in the front center portion of the casing are centrifugally separated by the rotation of the impeller body 8. After being blown off, it is sent toward the cutting blade of the flaker knife 1 by the tip side surface of the impeller plate 7 and further cut into small pieces by the cutting blade of the flaker knife 1. The cut pieces are splashed toward the inside of the casing from the gap formed by the cutting blade of the flaker knife 1 and the tip of the back pressure bar 9 that is provided facing the cutting blade, and thereafter. , Falls below the casing.

As shown in FIG. 10, the flaker knife used in the cutting apparatus as described above has a rectangular thin plate having a long side edge on one side with a predetermined angle and a back surface 12 and a back surface 12 of the blade.
And a screw hole 14 for fixing to the knife holder 6 with a mounting bolt on the other long side, and a knife holder 6 to which the flaker knife 1 is fixed for attaching to the segment 5. Slots 15 for mounting bolts are provided.

Conventionally, this flaker knife 1 is SK
The whole is formed of alloy tool steel such as D11, and the manufacturing process is as shown in FIG. 11, material discharge, machining (thickness, width, length, slot, hole, tap), quenching, tempering, distortion. Take, double-side rough grinding, finish grinding (length,
Width, thickness), blade attachment (sinking surface grinding), and final strain relief.

[0007]

Since the above-mentioned conventional flaker knife is formed of alloy tool steel such as SKD11 from the economical point of view, the cutting edge has a short service life of 5 to 6 hours. There is a drawback in that the work of removing from the knife holder, the work of re-grinding the surplus surface, the work of attaching to the knife holder and the segment, and the work of adjusting the cutting edge on top of that are necessary, which reduces the operating rate of the cutting device.

Further, in order to prevent cracks originating from the screw holes due to strong tightening of the mounting bolts for mounting the flaker knife on the knife holder or due to impact during cutting, it is common practice. Uses a so-called partial quenching method in which the flank of the flaker knife is not quenched and only the long side that serves as the cutting edge is hardened. In this case, the finished flaker knife has an internal stress that tends to be displaced mainly in the direction parallel to the short side of the rectangular flaker knife, and the width of the knife is narrowed due to repeated grinding repairs on the surging surface. As a result, an imbalance occurs in the internal stress, and as shown in FIG. 12, a strain that displaces in the blade edge or the ridge direction, that is, so-called widthwise bending occurs. In order to straighten the edge line of the flaker knife that has been bent in the width direction by re-grinding, it is necessary to grind the flank face a lot, which also shortens the life of the flaker knife. Occurs.

As described above, in the flaker knife formed of alloy tool steel such as SKD11, the cutting blade has a short service life, and when it is attempted to grind the restoration surface to restore the sharpness, the flaking knife is removed each time. Regrinding, mounting,
If each work of adjusting the cutting edge is necessary and the frequency is high,
There is a technical problem that the operating rate of the cutting device is reduced and it takes time and effort. Also, since the long side of the rectangular material, which serves as the cutting edge, is partially quenched, the internal stress becomes unbalanced as the knife width becomes narrower due to repeated grinding and repair of the surplus surface, resulting in bending in the width direction. There is also a technical problem that comes out.

The present invention has been earnestly researched and developed in order to solve such a technical problem, and as a result, a flaker having a long cutting edge life, which is not much different from a conventional flaker knife made of alloy tool steel in terms of price. In order to provide a knife, only the cutting edge part consisting of the surfacing surface and the back surface of the blade needs to be a high speed tool steel heat treated material with large wear resistance and impact resistance, and the high speed of the minimum necessary thickness I noticed that it would be possible to use a composite material of tool steel plate and mild steel plate of a predetermined thickness, thereby extending the life of the cutting edge of the flaker knife, and by extension extending the life of the flaker knife itself, and Since the direction in which the internal stress occurs in the material is mainly one direction in the thickness direction, there is almost no bending in the width direction due to repeated regrinding of the fillet surface, and from this point as well, there is a long-term tendency. It is a first object of the present invention to provide a flaker knife can be used.

Further, it becomes difficult to tap the high-speed tool steel portion that has been subjected to heat treatment and has a sufficiently high hardness, but this point can be overcome by devising a screw pilot hole. It is the second purpose.

Further, the flaker knife of the present application is a brazing composite material of high speed tool steel and mild steel, in particular, a joining steel plate material in which the high speed tool steel portion is heat treated at the same time as brazing to have a sufficiently high hardness. Since the pilot holes and slots for screws are machined, the machining becomes difficult accordingly, and because the composite material brazed with high-speed tool steel is used, the material cost is higher than the conventional product. However, the third purpose is to overcome these problems by devising a new manufacturing method.

[0013]

Means and Actions for Solving the Problems
In order to solve the above technical problems, the following means are adopted.

According to a first aspect of the present invention, which is intended to receive a patent, one of the long side edges of a rectangular thin steel plate is a cutting edge composed of a relief surface and a blade back surface of a predetermined angle over the entire length, and the other long side vicinity thereof. In a flaker knife in which a plurality of screw holes for mounting bolts and at least one slot extending from a predetermined position on the inside to the other long side edge are provided, the rectangular thin steel sheet includes a brazing layer. Is a joining thin steel sheet of a mild steel sheet and a high-speed tool steel sheet, and the flank face is provided so that the surface of the joining thin steel sheet side on the high-speed tool steel is the back surface of the blade. It's a knife.

The present invention is a basic invention of the structure of a flaker knife in which the life of the cutting blade is extended. That is, the flaker knife is a brazed composite thin steel plate of a mild steel plate and a high speed tool steel plate, and a surplus surface is provided so that the high speed tool steel side surface becomes the blade back surface. This improves the wear resistance and impact resistance of the cutting edge portion. Also, the entire flaker knife is made of the same material in the thickness direction, and there is no internal stress that displaces in the direction parallel to the short side of the rectangular material. Even if the width becomes narrow, there is almost no bending in the width direction, so that it is not necessary to grind the surplus surface a lot.

In addition to the first aspect of the invention, the second aspect of the invention, which seeks to receive a patent, has a tapered hole for a mounting bolt that has a smaller diameter on the mild steel surface side than on the high-speed tool steel surface side. It is a flaker knife characterized by the following.

According to a second aspect of the present invention, by making the pilot hole of the screw hole tapered, the pilot hole of the screw hole of the high speed tool steel portion which is heat-treated and has a sufficiently high hardness is made slightly larger. It is intended to reduce the burden on the tap by placing it. That is, the economical effect is obtained by suppressing the wear of the tap and making the tap last longer.

According to a third invention to obtain a patent, one side of a long side of a rectangular thin steel plate is a cutting edge composed of a relieving surface and a back surface of the blade at a predetermined angle over the entire length, and the other side of the long side is adjacent. Is provided with a plurality of screw holes for mounting bolts and at least one slot extending from a predetermined inner position to the other long side edge, and the rectangular thin steel sheet is a mild steel sheet with a brazing layer interposed therebetween. A method for manufacturing a flaker knife, which is a joining thin steel sheet with a high-speed tool steel sheet, and in which the above-mentioned surging surface is provided so that the high-speed tool steel side surface of the joining thin steel sheet is a blade back surface. A first step of brazing a mild steel plate and a high-speed tool steel plate of a predetermined size together with heat treatment to form a joined steel plate material, and irradiating a laser beam along a predetermined shape of the flaker knife. Contour and mounting Second step of cutting out the pilot hole of the pilot screw hole, a step of processing a female screw with a tap of a predetermined size in the pilot hole opened in the second step, and cutting into a flaker knife shape in the second step. A third step including a step of providing a surplus surface to the bonded steel sheet at a predetermined angle from a predetermined direction, a step of finishing the bonded steel sheet to a predetermined length, and a step of finishing the steel sheet to a predetermined thickness. It is a method for producing a flaker knife characterized by the above.

The third invention is to develop a method for manufacturing the flaker knife of the first invention. The hardness of the high-speed tool steel portion is determined by the first step of heat-treating the high-speed tool steel to be the cutting edge portion while brazing the mild steel plate and the high-speed tool steel plate to produce a joined steel plate material of a predetermined size. It's high enough. As a result, except for the thickness processing performed by the grinding machine,
Considering that it is difficult to machine the length, width, screw hole pilot hole, slot, etc. by machining, the flaker knife contour including the slot and screw hole pilot hole should be cut out with a laser beam. It was done. After that, tap processing, length processing, thickness processing, and surplus surface processing blade attachment are performed.

In the present invention, since the contour of the flaker knife is cut out by the laser beam, the machining such as the length machining, the width machining, the slot machining, the screw hole pilot hole machining, etc., which have conventionally been separately carried out, is carried out. Is unnecessary.

According to a fourth aspect of the present invention, which is intended to receive a patent, one side of a long side of a rectangular thin steel plate is a cutting edge consisting of a surplus surface and a back surface of the blade having a predetermined angle over the entire length, and the other side of the long side is adjacent Is provided with a plurality of screw holes for mounting bolts and at least one slot extending from a predetermined inner position to the other long side edge, and the rectangular thin steel sheet is a mild steel sheet with a brazing layer interposed therebetween. It is a joining thin steel plate with a high speed tool steel plate, and the surging surface is provided so that the high speed tool steel side surface of the joining thin steel plate is the blade back surface, and the pilot hole of the screw hole for the mounting bolt is In the method of manufacturing a flaker knife in which the mild steel surface side has a smaller diameter than the high speed tool steel surface side, the flaker knife has a predetermined size of a mild steel plate and a predetermined size of a high speed tool steel plate. Brazing and heat treatment A first step of forming a steel plate material; a straight hole serving as a base hole for the outline of the flaker knife and a tapered pilot hole of a screw hole for a mounting bolt by irradiating a laser beam along a predetermined shape; Second to cut out
Step, through a straight hole opened in the second step, pass a taper processing tool of a predetermined dimension from a predetermined direction, then process a female screw with a tap of a predetermined dimension, and a flaker knife shape in the second step A third step including a step of providing a surplus surface to the jointed steel sheet cut out in a predetermined direction from a predetermined direction, a step of finishing the jointed steel sheet into a predetermined length, and a step of finishing into a predetermined thickness. A method for producing a flaker knife, which is characterized by the fact that it is empty.

A fourth invention is to develop a manufacturing method of the flaker knife of the second invention, and one step of the manufacturing method of the third invention is to make the pilot hole of the screw hole for attachment a taper hole. This is a modified part, that is, the process of cutting the pilot hole of the screw hole with a laser beam is changed to the process of cutting a straight base hole that is the pilot hole of the tapered hole with a laser beam, and the straight base hole is This is a manufacturing method in which a step of passing a taper processing tool in an orientation such that the diameter of the mild steel surface side is smaller than that of the speed tool steel surface side is added.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a front view of a flaker knife according to the present invention, and FIG. 2 is a side view of FIG. The flank 11 of the flaker knife 1 made of a bonded thin steel plate brazed with a mild steel plate 21 and a high speed tool steel plate 22 is ground at a predetermined angle α so that the high speed tool steel side surface becomes the blade back surface 12, The tip is the cutting blade 13. Then, as shown in FIG. 1, a slot 15 and a mounting screw hole 14 are provided at predetermined positions as in the conventional product.

In the present embodiment, a joining steel plate having a thickness of 2 mm and a brazed steel plate having a thickness of 2 mm and a mild steel plate of 6 mm ground on one side is 374 mm long × 100 mm wide × 100 mm wide.
The thickness is 5 mm and the angle of receding α is 36 degrees, and the length is 524 mm
A flaker knife having a width of 100 mm, a thickness of 5 mm, and a prolongation angle α of 36 degrees was obtained.

In order to compare the bending in the width direction between the flaker knife according to the present invention and the flaker knife according to the conventional alloy tool steel, the flaker knife according to the present invention (3
As a result of performing a crushing test by scraping the surplus surface (74 mm × 100 mm × 5 mm) by grinding, a conventional product had a widthwise bending of about 0.3 mm when the width was driven in by 30 mm. With the flaker knife of the present invention, it was tried to drive up to a width of 50 mm, which is a standard for an actual rising edge, but almost no bending in the width direction was observed.

Next, as another embodiment, a mounting screw hole 1
A flaker knife in which the prepared hole of No. 4 is a tapered hole will be described. FIG. 3 is a front view of the flaker knife according to the present invention, and FIG. 4 is an enlarged cross-sectional view (viewed in the direction of arrow Y-Y) near the mounting screw hole 14. The tapered hole has a smaller diameter on the mild steel surface 31 side than on the high-speed tool steel surface 32 side, and the hole diameter of the smaller diameter is slightly smaller than the lower hole diameter of the standard screw hole. If the taper degree of the taper hole machining tool is 5 degrees on one side, the plate diameter is 5 mm, and in the case of an M8 tap, the hole diameter on the small diameter side is 6.5 mm and the hole diameter on the large diameter side is 7.4 mm.

Next, a method for manufacturing the flaker knife of the first invention of the present application will be described with reference to FIG. 1200 ° C. to 1300 while maintaining a non-oxidized state by interposing a brazing material 30 between a mild steel plate 21 of a predetermined size and a high speed tool steel plate 22 whose brazed surface is a finished surface suitable for brazing.
After heating to ℃, quenching the high speed tool steel portion, brazing the mild steel plate 21 and the high speed tool steel plate 22, cooling to a predetermined temperature, and then reheating to 500 to 600 ° C. and tempering. To form a joined steel plate material A. The joint steel sheet material A is roughly ground on both sides after straightening. Next, the joining steel plate material A is irradiated with a laser beam to cut out the outline of the flaker knife 1 including the pilot hole 16 for the mounting bolt screw hole and the slot 15 as shown in FIG.
Next, the pilot hole 16 cut out by the laser beam is internally threaded with a tap having a predetermined size, and the joined steel plate cut out to the contour of the flaker knife 1 has a predetermined finish length and a predetermined finish thickness. Then, the flaker knife 1 is completed by grinding the shingling surface 11 and finally attaching the cutting edge 13 to the grinding surface 11. In addition, it is also an important step to incorporate strain correction work as needed.

Next, a method for manufacturing the flaker knife of the second invention of the present application will be described. The base plate 17 of the tapered pilot hole of the screw hole for the mounting bolt by irradiating the joining steel plate material A formed in the same step as the manufacturing method of the flaker knife of the first invention of the present application with a laser beam, and Slot 1
The contour of the flaker knife 1 containing 5 is cut out. next,
In the base hole 17 cut out by the laser beam, from the high speed tool steel surface 32 side, a taper machining tool of a predetermined size (for example,
Through a taper end mill) to form a taper hole of a predetermined size. Next, female thread processing is performed on the tapered hole with a tap of a predetermined size,
The joined steel plate cut out to the contour of the flaker knife 1 is ground to a predetermined finish length and a predetermined finish thickness, and finally the cutting blade 13 is attached while the flank surface 11 is ground to attach the flaker knife 1 to the flaker knife 1. To complete. FIG. 7 shows the flow of the manufacturing process based on the manufacturing method of the flaker knife according to the present invention described above. In addition, although the dimensions of the flaker knife and the like are illustrated by giving numerical values in the embodiments described above, the present invention is not limited to these numerical values, and the number of screw holes and slots is also limited to the embodiments. Of course, it is not what is done.

[0029]

As described above, according to the invention of the present application, the flaker knife itself is made of a brazing-bonded thin steel plate of a mild steel plate and a high-speed tool steel plate, and heat treatment is performed to sufficiently improve wear resistance and impact resistance. Since the cutting edge is provided on the side of the high speed tool steel, the life of the cutting edge is extended several times compared to the flaker knife made of conventional alloy tool steel, so it is necessary to restore the sharpness by grinding the relief surface. That is, the number of operations required for removing the segment and knife holder, re-grinding, attaching to the knife holder and segment, adjusting the cutting edge, and the like is reduced, and the operating rate of the cutting device is dramatically improved. In addition, the entire flaker knife is made of the same material in the thickness direction, and there is no internal stress that displaces in the direction parallel to the short side of the rectangular material. Since there is almost no bending in the width direction of the flaker knife, there is no need to grind the surplus surface too much.
It will be economical. In addition to the basic effects described above, the second aspect of the present invention reduces the load on the tap by reducing the diameter of the screw hole for the mounting bolt to a taper hole in which the surface side of the mild steel is smaller than the surface side of the high speed tool steel. Wear of the tap is suppressed in the car knife manufacturing process. The third invention and the fourth invention are manufacturing methods relating to the flaker knife of the first invention and the second invention, and the contour of the flaker knife including the slot and the prepared hole of the screw hole are cut out by a laser beam. In addition, it is possible to easily deal with a material that has been subjected to heat treatment and has a sufficiently high hardness, and it is possible to reduce the number of steps compared with the conventional method of manufacturing using alloy tool steel. It is possible to obtain a flaker knife that has a price that is not much different from that of alloy tool steel and has a life that is several times longer.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a flaker knife of the present invention.

FIG. 2 is a side view of the flaker knife shown in FIG.

FIG. 3 is a front view showing another embodiment of the flaker knife of the present invention.

FIG. 4 is an enlarged cross-sectional view of the vicinity of a mounting screw hole of the flaker knife shown in FIG.

FIG. 5 is a perspective view showing a joined steel plate material involved in the manufacturing method of the present invention.

FIG. 6 is a perspective view showing a state where a contour of a flaker knife is cut out by irradiating a joined steel plate material according to the manufacturing method of the present invention with a laser beam.

FIG. 7 is a flowchart showing a flow of manufacturing steps based on the method for manufacturing a flaker knife according to the present invention.

FIG. 8 is a front view showing an outline of a Plale-type cutting device as one type of cutting device.

9 is a schematic side view of the cutting device shown in FIG.

FIG. 10 is a perspective view showing a conventional flaker knife.

FIG. 11 is a flowchart showing the flow of a conventional flaker knife manufacturing process.

FIG. 12 is a perspective view showing a state where the flaker knife is bent in the width direction.

[Explanation of main symbols]

 1 Flaker knife 2 Ring-shaped holding plate 3 Ring-shaped holding plate 4 Inner face 5 Segment 6 Knife holder 7 Impeller plate 8 Impeller body 9 Back pressure bar 11 Recession surface 12 Blade back surface 13 Cutting blade 14 Screw hole 15 Slot 16 Screw Hole pilot hole 21 Mild steel plate 22 High speed tool steel plate 30 Wax layer A Bonding steel plate material

Claims (4)

[Claims] 1. A rectangular thin steel sheet has one long side edge formed as a cutting edge consisting of a relief surface and a blade back surface having a predetermined angle over the entire length, and a plurality of screws for mounting bolts near the other long side. A flaker knife provided with a hole and at least one slot extending from a predetermined position on the inner side to the side edge of the other long side, wherein the rectangular thin steel sheet is a mild steel sheet with a brazing layer and a high-speed tool. A flaker knife which is a thin steel plate joined to a steel plate, wherein the surfacing surface is provided so that the surface of the joined thin steel plate on the high speed tool steel side is the back surface of the blade. 2. A rectangular thin steel plate has one long side edge formed as a cutting edge having a ridge surface and a blade back surface having a predetermined angle over the entire length, and a plurality of screws for mounting bolts near the other long side. A flaker knife provided with a hole and at least one slot extending from a predetermined position on the inner side to the side edge of the other long side, wherein the rectangular thin steel sheet is a mild steel sheet with a brazing layer and a high-speed tool. It is a thin steel plate joined to a steel plate, and the surplus surface is provided so that the high speed tool steel side surface of the joined thin steel plate is the back surface of the blade, and the pilot hole of the screw hole for the mounting bolt is a high speed tool. A flaker knife characterized by a tapered hole having a smaller diameter on the mild steel surface side than on the steel surface side. 3. A rectangular thin steel plate has a long side edge formed on one side of a long side, which is a cutting edge composed of a relief surface and a blade back surface having a predetermined angle, and a plurality of screws for mounting bolts near the other long side. A hole and at least one slot extending from a predetermined position on the inner side to the other side of the long side are provided, and the rectangular thin steel sheet is a joining thin steel sheet formed by interposing a brazing layer on a mild steel sheet and a high-speed tool steel sheet. In the manufacturing method of the flaker knife in which the surfacing surface is provided so that the high speed tool steel side surface of the joined thin steel sheet is the blade back surface, a mild steel plate of a predetermined size and a high size of a predetermined size are provided. A first step of brazing the speed tool steel plate and heat-treating to form a joined steel plate material, and irradiating a laser beam along a predetermined shape with the contour of the flaker knife and the screw hole for the mounting bolt. Cut out the pilot hole In a second step, a step of processing a female screw with a tap having a predetermined size in the prepared hole formed in the second step, and a joining steel plate cut into a flaker knife shape in the second step, from a predetermined direction And a third step including a step of finishing the joined steel sheet to a predetermined length and a step of finishing the joined steel sheet to a predetermined thickness. . 4. A rectangular thin steel sheet has one long side edge formed as a cutting edge consisting of a relief surface and a blade back surface having a predetermined angle over the entire length, and a plurality of screws for mounting bolts near the other long side. A hole and at least one slot extending from a predetermined position on the inner side to the other side of the long side are provided, and the rectangular thin steel sheet is a joining thin steel sheet formed by interposing a brazing layer on a mild steel sheet and a high-speed tool steel sheet. The joining surface is provided so that the surface of the joining thin steel sheet on the high speed tool steel side is the back surface of the blade, and the pilot hole of the screw hole for the mounting bolt is a mild steel than the front side of the high speed tool steel. In the manufacturing method of the flaker knife, which has a tapered hole with a smaller diameter on the surface side,
The first step of brazing a mild steel plate of a predetermined size and a high-speed tool steel plate of a predetermined size together with heat treatment to form a joined steel plate material, and irradiating a laser beam along a predetermined shape A second step of cutting out the outline of the flaker knife and a straight hole serving as a base hole of a tapered pilot hole of a screw hole for a mounting bolt, and a straight hole opened in the second step from a predetermined direction Pass the taper processing tool of the specified size, and then process the female screw with the tap of the specified size, and in the second step, attach the surplus surface to the joined steel plate cut out in the shape of the flaker knife at the specified angle from the specified direction. A method for manufacturing a flaker knife comprising a step of attaching and a third step of finishing the joined steel plate to a predetermined length and a predetermined thickness.