JP2021040493A - Manufacturing method of cutting tool - Google Patents

Abstract

To provide a manufacturing method of cutting tools capable of easily and inexpensively manufacturing weight-reduced cutting tools, while retaining sharpness.SOLUTION: A cutting tool (e.g., a sickle) is manufactured by a manufacturing method of cutting tools comprising: a first cutting step of cutting out, from a plate-like first base material, cutting edge pieces that extend in a prescribed direction and, the thickness of which gradually decreases from one side toward the other side in the width direction being orthogonal to the prescribed direction; a second cutting step of cutting out, from a plate-like second base material having specific gravity smaller than that of the first base material, trunk part pieces having substantially same thickness as that of facing edge parts, the edge parts in the side having large thickness in the cutting edge pieces and having a shape to be fitted with the facing cutting edges; and an integration step of fitting the cutting edge pieces and the trunk part pieces with one another to integrate them together.SELECTED DRAWING: Figure 6

Description

The present invention relates to a method for manufacturing a cutting tool.

The cutting tool generally has a cutting edge portion including a sharp cutting edge and a body portion thicker than the cutting edge portion integrally.

As an example of the above-mentioned blade, for example, the one of Patent Document 1 is known. The knife (kitchen knife) of Patent Document 1 is made of a material in which the body portion (described as “base portion” in Patent Document 1) and the cutting edge portion are different. Specifically, the body portion contains a metal such as a titanium alloy (first metal), and the cutting edge portion contains a metal such as nickel (second metal) and hard particles.

Such a blade is obtained by injecting the powder of the second metal and the hard particles onto the end of the body and sintering the powder of the second metal on the end of the body. .. At this time, a laser cladding technique for melting the metal powder with a laser is used.

According to the invention described in Patent Document 1, it is possible to obtain a blade having a reduced weight while maintaining sharpness.

JP-A-2018-008074

However, when the cutting tool is manufactured by using the laser cladding technique as in the invention described in Patent Document 1, there is a problem that the manufacturing cost increases and the manufacturing of the cutting tool is not easy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a blade, which enables easy and inexpensive production of a lightweight blade while maintaining sharpness. ..

To solve the above problems, the method for manufacturing a blade according to the present invention extends from a plate-shaped first base material in a predetermined direction and gradually reduces the thickness from one to the other in the width direction orthogonal to the predetermined direction. The first cutting step of cutting out the cutting edge piece having a shape to be formed, and the facing edge portion which is the thicker side edge portion of the cutting edge piece from the plate-shaped second base material having a specific gravity smaller than that of the first base material. The second cutting step of cutting out a body piece having substantially the same thickness and having a shape that can be fitted to the facing edge portion, and an integral body in which the cutting edge piece and the body piece are fitted to each other and integrated. Including the chemical conversion process.

According to this cutting tool manufacturing method, the body piece, which is thicker than the cutting edge piece, is made of a material having a specific gravity smaller than that of the cutting edge piece. Therefore, when the cutting edge piece and the body piece are made of the same material, A relatively lightweight blade can be obtained.

Further, since the cutting edge piece is made of a material having a higher specific gravity than the body piece, it is possible to select a material having high hardness and excellent wear resistance with respect to the cutting edge piece. Therefore, a cutting tool having good sharpness can be obtained.

Further, since the body piece and the cutting edge piece are fitted and integrated, it is possible to easily and inexpensively obtain a cutting tool in which the body portion and the cutting edge portion are made of different materials.

In the method for manufacturing a cutting tool, in the first cutting step, a plurality of protrusions are formed on the facing edges of the cutting edge piece, and in the second cutting step, one side edge of the body piece is formed. It is desirable to form a plurality of recesses that can be fitted with the protrusions, and in the integration step, integrate the cutting edge piece and the body piece by fitting the protrusions into the recesses.

In the method for manufacturing a blade, in the integration step, it is desirable to inject an adhesive into the gap between the protrusion and the recess when the protrusion is fitted into the recess.

According to this configuration, since the adhesive is injected into the gap between the protrusion and the recess, the bonding strength between the pieces when the body piece and the cutting edge piece are integrated can be increased.

According to this configuration, the cutting edge piece and the body piece can be easily integrated by fitting the protrusion formed on the cutting edge piece into the recess formed on the body portion.

Further, since a plurality of protrusions are formed on the relatively thick end (opposing edge) of the cutting edge piece, and the plurality of protrusions are fitted into the plurality of recesses formed on the body piece. , Sufficient fitting strength can be obtained when combining the cutting edge piece and the body piece.

In the method for manufacturing a cutting tool, in the first cutting step, a plurality of the cutting edge pieces are cut out from a plurality of regions adjacent to each other in the longitudinal direction of the first base material, and in the second cutting step, the second base material is used. A plurality of the body pieces are cut out from a plurality of regions adjacent to each other in the longitudinal direction, and the body pieces are formed into a shape that can be fitted to each other. It is desirable to integrate the plurality of cutting edge pieces and the plurality of body pieces by fitting the pieces to each other and fitting the adjacent body pieces to each other.

According to this configuration, a plurality of cutting edge pieces cut out from the first base material and a plurality of body pieces cut out from the second base material are integrated to form a more complicated (or long) piece. A blade with a shape can be obtained.

In the method for manufacturing a cutting tool, when the edge of the cutting edge piece on the thin side is used as the cutting edge, in the integrating step, the plurality of cutting edge pieces are formed so that the angle formed by the adjacent cutting edges is less than 180 degrees. It is desirable to combine them.

According to this configuration, since the angle formed by the adjacent cutting edges is less than 180 degrees, it is possible to obtain a cutting edge having a curved cutting edge portion as a whole, such as a sickle.

The method for manufacturing a cutting tool further includes a cutting step of processing a region of the first base material located outside from the middle portion in the width direction so that the thickness becomes thinner toward the outside in the width direction, and the first cutting is performed. In the step, it is desirable to cut out the plurality of cutting edge pieces so as to include a part of the region machined by the cutting step.

According to this configuration, since a plurality of cutting edge pieces are cut out from the first base material after forming the cutting edge portion on the first base material, sharpening processing is performed on each cutting edge piece after cutting out the plurality of cutting edge pieces. It is possible to reduce the man-hours required for cutting the blade as compared with the case of applying the blade.

In the method for manufacturing a blade, a region processed by the cutting step between the heat treatment step of applying a heat treatment to the first base material after the cutting step and the heat treatment step and the first cutting step. It is desirable to further include a polishing step of polishing.

According to this configuration, since the first base material is heat-treated, good toughness can be imparted to the first base material. Further, since the cutting edge portion is polished after the first base material is heat-treated, the cutting edge portion blunted by the previous heat treatment can be made sharp again.

In the method for manufacturing a blade, it is desirable that in the first cutting step, each split cutting edge piece is cut out by laser processing, and in the second cutting step, each split body piece is cut out by laser machining.

According to this configuration, since the laser cutter is used to cut out each split cutting edge piece and each split body piece, the shapes of each split edge piece and the split body piece can be finished with high accuracy.

As described above, it is possible to provide a cutting tool manufacturing method capable of easily and inexpensively manufacturing a lightweight cutting tool while maintaining sharpness.

It is a top view which shows the whole structure of the blade obtained by the manufacturing method of the blade of this invention. The first flat bar for forming the cutting edge portion of the cutting tool, (a) is a plan view and a side view before forming the cutting edge portion, and (b) is a plan view and a side surface view after forming the cutting edge portion. It is a figure. It is a top view which shows the state which the cut-out line of each cutting edge piece was drawn on the 1st flat bar. It is a top view which shows the state which the cutout line of each body piece was drawn on the 2nd flat bar. It is a top view which shows the state in which the sub-assy is assembled from the each cutting edge piece cut out from the 1st flat bar, and each body piece piece cut out from the 2nd flat bar. It is a top view which shows the state in which each cutting edge piece and each body piece are combined and integrated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. 1. Structure of the blade First, the overall configuration of the blade 1 obtained by the manufacturing method of the present invention will be described.

The blade 1 is a sickle for cutting a plant or the like, and has a main body portion 2 and a handle 3 for holding the main body portion 2.

The main body 2 includes a fixing portion 9 fixed to the handle 3, a body portion 5 extending from the fixing portion 9 and exhibiting a curved shape, and a cutting edge formed on one side edge (inner peripheral edge) of the body portion 5. It has a part 7 integrally.

The handle 3 has a holding hole (not shown), and the fixing portion 9 is fitted into the holding hole to hold the main body portion 2.

2. Method for manufacturing a cutting tool Next, a method for manufacturing a cutting tool according to an embodiment of the present invention will be described.

In the present embodiment, two types of plate materials (first base material 11 and second base material 12) having different materials are prepared. First, a cutting edge portion 17 is formed on the first base material 11, and a plurality of cutting edge pieces 70 are cut out from the first base material 11, and a plurality of body pieces 50 are cut out from the second base material 12. Then, the cutting tool 1 is manufactured by integrating each cutting edge piece 70 and each body piece 50.

Specifically, the method for manufacturing a cutting tool according to the present embodiment includes the following steps.

(1) Blade-attaching process The first base material 11 used in the present embodiment is a steel plate material such as an SK material. As the first base material 11, a flat bar having an appropriate area is prepared according to the size of the cutting tool 1 to be manufactured. The number of flat bars required to obtain one blade 1 may be one, but in the present embodiment, two rectangular (rectangular) flat bars, that is, the first flat bar, as shown in FIG. 11A and the second flat bar 11B are used. Since the procedure for forming the cutting edge portion 17 on the first flat bar 11A and the second flat bar 11B is exactly the same, both are collectively referred to as the flat bar 11A (11B) in this section.

The flat bar 11A (11B) before forming the cutting edge portion 17 is a rectangular plate material having a constant thickness as shown in FIG. 2A. The step of processing this plate material to form the cutting edge portion 17 is the cutting step. That is, in the blade attachment step, as shown in FIG. 2B, the flat bar 11A (11B) is sharpened from the middle portion to one end in the width direction to form the blade edge portion 17.

The flat bar 11A (11B) that has undergone the blade attachment process has a base portion 16 having a certain thickness and a cutting edge portion 17 that becomes thinner [outward in the width direction of the flat bar 11A (11B)] as the distance from the base portion 16 increases. .. A cutting edge 17a is formed at the tip of the cutting edge portion 17. The cutting edge portion 17 is a double-edged type cutting edge portion obtained by processing both sides of the side edges of the flat bar 11A (11B). In other words, the cutting edge portion 17 is formed so that the center line that divides the flat bar 11A (11B) into two in the thickness direction and the tip of the cutting edge portion 17 (the cutting edge 17a) substantially coincide with each other.

Examples of the method of attaching the blade to the flat bar 11A (11B) include a method of polishing one side edge with a grinding wheel and a method of crushing one side edge by applying pressure to the one side edge by forging or the like.

(2) Heat treatment step and polishing step After the cutting step, the flat bar 11A (11B) is heat-treated. The heat treatment includes quenching in which the flat bar 11A (11B) is rapidly cooled from a high temperature state, and tempering in which heat is applied again to the hardened flat bar 11A (11B).

After the above heat treatment, the cutting edge portion 17 is polished again to sharpen it. This is because the tip (edge) of the cutting edge portion 17 is blunted by the heat treatment, and it is necessary to sharpen the cutting edge again after the heat treatment. At this time, it is desirable to use a grindstone having a finer mesh than the grinding grindstone.

(3) First Cutting Step This step is a step of cutting out a plurality of cutting edge pieces 70 having a shape as shown in FIG. 3 from the flat bar 11A (11B) on which the cutting edge portion 17 is formed by the cutting step.

The plurality of cutting edge pieces 70 are nine pieces of the first to ninth cutting edge pieces 71 to 79 in the present embodiment. In the following, when referring to a specific cutting edge piece, it is described as the first cutting edge piece 71, the second cutting edge piece 72, ..., But when referring to each cutting edge piece without particular distinction, it is simply described as the cutting edge piece 70. To do.

As shown in FIG. 3A, the first to fourth cutting edge pieces 71 to 74 are cut out from four regions adjacent to each other in the longitudinal direction in the first flat bar 11A. Hereinafter, one side in the longitudinal direction of the first flat bar 11A from which the first cutting edge piece 71 is cut out is referred to as one end side A, and the other side thereof is referred to as the other end side B. As will be described later, the first cutting edge piece 71 cut out from the region of the farthest end side A is a piece corresponding to the most tip side (the side farthest from the handle 3) of the main body 2 of the cutting tool 1, and the farthest end. The fourth cutting edge piece 74 cut out from the region of the side B is a piece corresponding to an intermediate portion in the longitudinal direction (direction along the curved cutting edge portion 7) of the main body portion 2.

Further, as shown in FIG. 3B, the fifth to ninth cutting edge pieces 75 to 79 are cut out from five regions adjacent to each other in the longitudinal direction in the second flat bar 11B. Hereinafter, one side in the longitudinal direction of the second flat bar 11B from which the fifth cutting edge piece 75 is cut out is referred to as one end side A, and the other side thereof is referred to as the other end side B. As will be described later, the fifth cutting edge piece 75 cut out from the region on the farthest end side A is a piece corresponding to the intermediate portion in the longitudinal direction of the main body portion 2, and the fixed portion 9 cut out from the region on the farthest end side B. Is a piece corresponding to the portion closest to the base end side (the side closer to the handle 3) in the main body portion 2.

The first to ninth cutting edge pieces 71 to 79 are cut out from the flat bar 11A (11B) by a laser cutter.

As shown in FIGS. 3A and 5A, the first cutting edge piece 71 is cut out from the cutting edge body 171 cut out from the cutting edge portion 17 of the first flat bar 11A and from the base portion 16 of the first flat bar 11A. It is composed of a protrusion 91. The cutting edge main body 171 has a substantially quadrangular shape (trapezoidal shape) when viewed in a plan view, and has a sharp end on one end side A. Further, the cutting edge main body 171 has a shape in which the thickness gradually decreases from one side in the width direction orthogonal to the longitudinal direction to the other, and the cutting edge 171a is formed on the edge portion of the cutting edge main body 171 on the side where the thickness is small. The protrusion 91 is formed on the edge portion 171b (corresponding to the "opposing edge portion" of the present invention) on the thicker side (opposite side of the cutting edge 171a) of the cutting edge main body 171 and has an arc shape protruding from the cutting edge main body 171. Present.

As shown in FIGS. 3A and 5B, the second cutting edge piece 72 is cut out from the cutting edge body 172 cut out from the cutting edge portion 17 of the first flat bar 11A and from the base portion 16 of the first flat bar 11A. It is composed of a protrusion 92. The cutting edge main body 172 has a substantially quadrangular shape (trapezoidal shape) when viewed in a plan view. Further, the cutting edge main body 172 has a shape in which the thickness gradually decreases from one side in the width direction orthogonal to the longitudinal direction to the other, and the cutting edge 172a is formed at the edge portion of the cutting edge main body 172 having a smaller thickness. The protruding portion 92 is formed on the edge portion 172b on the thicker side (opposite side of the cutting edge 171a) of the cutting edge main body 172, and exhibits an arc shape protruding from the cutting edge main body 172.

As shown in FIGS. 3 and 5, the shapes of the third to eighth cutting edge pieces 73 to 78 are the same as those of the second cutting edge piece 72. That is, the cutting edge main bodies 173 to 178 cut out from the cutting edge portion 17 of the first flat bar 11A or the second flat bar 11B, and the protrusions 93 to 99 cut out from the base portion 16 of the first flat bar 11A or the second flat bar 11B. It is composed of. The third to eighth cutting edge pieces 73 to 78 are composed of a substantially square (trapezoidal) cutting edge main body 173 to 178 and arc-shaped protrusions 93 to 99 when viewed in a plan view. The cutting edge main bodies 173 to 178 have a shape in which the thickness gradually decreases from one side in the width direction to the other side. The cutting edge 173a to 178a is formed on the edge portion of the cutting edge main body 173 to 178 on the side where the thickness is small. The protrusions 93 to 98 are formed on the edges 173b to 178b opposite to the cutting edges 173a to 178a.

The ninth cutting edge piece 79 is cut out from the cutting edge main body 179 cut out from the cutting edge portion 17 of the second flat bar 11B and the base portion 16 of the second flat bar 11B, referring to FIGS. 3 (b) and 5 (i). It is composed of an arc-shaped protrusion 99. The cutting edge main body 179 is formed so that the length in the width direction becomes shorter toward the other end side B. Further, the cutting edge main body 179 has a shape in which the thickness gradually decreases from one side in the width direction to the other side. The protrusion 99 is formed on the edge 179b.

Here, the detailed shapes of the first to eighth cutting edge pieces 71 to 78 will be described with reference to FIG. FIG. 5 is a diagram showing a state in which the first to ninth cutting edge pieces 71 to 79 and the subassies 21 to 29 described later are assembled from the first to ninth body pieces 51 to 59 described later.

The angles α in FIGS. 5 (b) to 5 (h) represent the outer angles formed by the end edge of the one end side A of each of the second to eighth cutting edge pieces 72 to 78 and the cutting edge line, and are formed in FIGS. 5 (a) to 5 (a). The angle β of (g) represents the outer angle formed by the edge of the other end side B of each of the first to eighth cutting edge pieces 71 to 78 and the cutting edge line. The cutting edge line referred to here is an extension line obtained by extending the edge line corresponding to the cutting edge 171a to 178a of the cutting edge pieces 71 to 78 in the longitudinal direction. Further, the piece length L [see FIGS. 5A to 5H] represents the length of the first to eighth cutting edge pieces 71 to 78 in the longitudinal direction.

In the present embodiment, the angle α and the angle β are set to less than 90 degrees in order to obtain the main body portion 2 having a curved shape.

Comparing the angle α of the one end side A between the pieces, the angle α of the piece corresponding to the intermediate portion in the longitudinal direction of the cutting edge portion 7 is the angle of the piece corresponding to the tip end side or the base end side of the cutting edge portion 7. It tends to be smaller than α. For example, the angle α of the third to seventh cutting edge pieces 73 to 77 is made smaller than the angle α of the second cutting edge piece 72 or the eighth cutting edge piece 78.

Similarly, regarding the angle β of the other end side B, the angle β of the piece corresponding to the intermediate portion in the longitudinal direction of the cutting edge portion 7 is the angle β of the piece corresponding to the tip end side or the proximal end side of the cutting edge portion 7. Tends to be smaller than. For example, the angle β of the second to sixth cutting edge pieces 72 to 76 is made smaller than the angle β of the first cutting edge piece 71 or the seventh cutting edge piece 77.

Further, when the piece length L is compared between the pieces, the piece length L of the cutting edge piece corresponding to the intermediate portion in the longitudinal direction of the cutting edge portion 7 corresponds to the tip end side or the base end side of the cutting edge portion 7. It tends to be shorter than the piece length L of the cutting edge piece. For example, the piece length L of the second to fourth cutting edge pieces 72 to 74 is shorter than the piece length L of the first cutting edge piece 71, and the piece length L of the fifth to seventh cutting edge pieces 75 to 77. L is shorter than the piece length L of the eighth cutting edge piece 78.

The reason why the above differences are provided for the angles α, β and the length L is that the radius of curvature of the intermediate portion in the longitudinal direction of the main body 2 is reduced, and a curved shape suitable for a sickle is given to the main body 2. To do.

With the difference as described above for the piece lengths L of the cutting edge pieces 71 to 78, the number of protrusions provided on the cutting edge pieces 70 is also the intermediate portion in the longitudinal direction of the cutting edge portion 7. The number of protrusions provided on the cutting edge piece corresponding to the above tends to be smaller than the number of protrusions provided on the cutting edge piece corresponding to the tip end side or the proximal end side in the longitudinal direction of the cutting edge portion 7. .. For example, the number of protrusions provided on the first cutting edge piece 71, the second cutting edge piece 72, and the eighth cutting edge piece 78 is three, while the third cutting edge piece 73, the fourth cutting edge piece 74, and the seventh cutting edge piece 74. The number of protrusions provided on the cutting edge piece 77 is two, and the number of protrusions provided on the sixth cutting edge piece 76 is one.

(4) Second Cutting Step In this step, a plurality of body pieces 50 having a shape as shown in FIG. 4 and a fixing portion 9 are cut out from the second base material 12 having a specific gravity smaller than that of the first base material 11. It is a process.

The second base material 12 used in this embodiment is a plate material made of aluminum. Further, the thickness of the second base material 12 is substantially the same as the thickness of the first base material 11. As the second base material 12, a flat bar having an appropriate area is prepared according to the size of the cutting tool 1 to be manufactured. The number of flat bars required to obtain one blade 1 may be one, but in the present embodiment, two rectangular (rectangular) flat bars, that is, a third flat bar, as shown in FIG. 12A and a fourth flat bar 12B are used. When it is not necessary to distinguish between the third flat bar 12A and the fourth flat bar 12B in this section, both are collectively referred to as the flat bar 12A (12B).

The plurality of body pieces 50 are nine pieces of the first to ninth body pieces 51 to 59 in the present embodiment. In the following, when referring to a specific body piece, the first body piece 51, the second body piece 52, ..., Etc. will be described, but when referring to each body piece without particular distinction, the body is simply used. It is described as a part piece 50.

As shown in FIG. 4A, the first to fourth body pieces 51 to 54 are cut out from four regions adjacent to each other in the longitudinal direction in the third flat bar 12A. Hereinafter, one side in the longitudinal direction of the third flat bar 12A from which the second body piece 52 is cut out is referred to as one end side A, and the other side thereof is referred to as the other end side B.

Further, as shown in FIG. 4B, the fifth to ninth body pieces 55 to 59 and the fixing portion 9 are cut out from six regions adjacent to each other in the longitudinal direction in the fourth flat bar 12B, respectively. Hereinafter, one side in the longitudinal direction of the fourth flat bar 12B from which the fifth body piece 55 is cut out is referred to as one end side A, and the other side thereof is referred to as the other end side B.

The first to ninth body pieces 51 to 59 and the fixing portion 9 are cut out from the second base material 12 by a laser cutter.

As shown in FIGS. 4A and 5A, the first body piece 51 has a shape in which the length in the width direction becomes shorter toward the end of one end side A (see FIG. 3). .. The thickness of the first body portion piece 51 is substantially the same as the thickness of the edge portion 171b of the cutting edge main body 171 of the first cutting edge piece 71. A recess 81 that can be fitted with the protrusion 91 is formed on one side edge of the first body piece 51 in the width direction. Further, a protrusion 31 is formed at the end of the first body piece 51 on the side adjacent to the second body piece 52 (the other end side B). The protrusion 31 has an arc shape protruding from the first body piece 51.

As shown in FIGS. 4A and 5B, the second body piece 52 has a substantially quadrangular shape, and the thickness thereof is the thickness of the edge 171b of the second cutting edge piece 72 in the cutting edge main body 172. It is almost the same. A recess 82 that can be fitted with the protrusion 92 is formed on one side edge of the second body piece 52 in the width direction. An arcuate protrusion 32 is formed at the end of the second body piece 52 on the side adjacent to the third body piece 53 (the other end side B), and the side adjacent to the first body piece 51 (one end). A recess 41 that can be fitted with the protrusion 31 of the first body piece 51 is formed at the end of the side A).

The shapes of the third to ninth body pieces 53 to 59 are the same as those of the second body piece 52. That is, the third to ninth body pieces 53 to 59 have a substantially square shape, and the thickness thereof is substantially the same as the thickness of the edges 173b to 179b in the cutting edge main bodies 173 to 179 of the cutting edge pieces 73 to 79. Recesses 83 to 89 are formed on one side edge in the width direction of the third to ninth body pieces 53 to 59. Further, recesses 42 to 48 are formed on one end side A of the third to ninth body pieces 53 to 59, and protrusions 33 to 39 are formed on the other end side B.

The fixing portion 9 has a recess 49 that can be fitted with the protrusion 39 at the end on the side (one end side A) adjacent to the ninth body piece 59.

Here, the relationship between the shapes of the body pieces 51 to 59 and the shapes of the cutting edge pieces 71 to 79 will be described with reference to FIG.

As shown in FIG. 5, the length of the side on which the recesses 81 to 89 are formed in each of the body pieces 51 to 59 is a straight line corresponding to the edges 171b to 179b of the cutting edge bodies 171 to 179 of the cutting edge pieces 71 to 79. Equal to length.

Further, when the body pieces 51 to 59 and the cutting edge pieces 71 to 79 are combined as shown in FIG. 5, the other end side B of the other end side B of the body pieces 51 to 58 and the other end side of the cutting edge pieces 71 to 78 The end edges of B are linearly connected to each other, and the end edge of one end side A of the body pieces 52 to 59 and the end edge of one end side A of the cutting edge pieces 71 to 79 are linearly connected to each other.

(5) Integration Step In this step, the cutting edge pieces 71 to 79 cut out from the first base material 11 and the body pieces 51 to 59 and the fixing portion 9 cut out from the second base material 12 are shown in FIG. This is a step of forming the main body portion 2 as shown in FIG. 1 by combining and integrating as described above.

The cutting edge pieces 71 to 79 and the body pieces 51 to 59 cut out in the cutting step become subassesies 21 to 29 as shown in FIG. 5 by fitting the corresponding protrusions and recesses. In the following, when referring to a specific sub-assy, it is described as the first sub-assy 21, the second sub-assy 22, ..., Etc., but when referring to each sub-assy without particular distinction, it is simply described as the sub-assy 20. To do. Each sub-assy 20 and the fixing portion 9 are integrated by fitting the corresponding protrusions and recesses as shown in FIG. 6 to form the main body 2.

Specifically, the first body portion piece 51 and the first cutting edge piece 71 are integrated by fitting the protrusion 91 and the recess 41 to form the first sub-assess 21. Further, the second body portion piece 52 and the second cutting edge piece 72 are integrated by fitting the protrusion 92 and the recess 42 to form the second sub-assy 22. Hereinafter, by the same procedure, the body pieces 53 to 59 and the cutting edge pieces 73 to 79 are integrated to form the subassies 23 to 29 shown in FIG.

Further, the first sub-assy 21 and the second sub-assy 22 are integrated by fitting the protrusion 31 and the recess 41, and the second sub-assy 22 and the third sub-assy 23 are the protrusion 32 and the recess 42. Is integrated by fitting with. Hereinafter, by the same procedure, each sub-assy 20 and the fixing portion 9 are integrated as shown in FIG. 6 to form the main body portion 2.

When integrating each piece, a metal adhesive is injected into the gap between the protrusion and the recess. As the metal adhesive, an adhesive having a stable tensile force at the time of fixing and having heat resistance, for example, an epoxy-based adhesive or a silicon-based adhesive is used.

Through the above procedure, the first to ninth subassies 21 to 29 and the fixing portion 9 are integrated in this order in an adjacent state, and the main body portion 2 is obtained. By setting the angles α and β of the respective cutting edge pieces 70 described in (3) above, the angles formed by the cutting edge 171a to 179a of the adjacent cutting edge pieces 71 to 79 are less than 180 degrees. For example, the angle formed by the cutting edge 171a of the first cutting edge piece 71 and the cutting edge 172a of the second cutting edge piece 72, and the angle formed by the cutting edge 172a of the second cutting edge piece 72 and the cutting edge 173a of the third cutting edge piece 73 are 180 degrees, respectively. Is less than. This also applies between the adjacent cutting edges 173a to 179a in the third cutting edge piece 73 to the ninth cutting edge piece 79. The angle formed by the cutting edges 173a to 179a becomes smaller in the intermediate portion in the longitudinal direction of the main body portion 2 (particularly, the fourth sub-assy 24 to the sixth sub-assy 26). As a result, the main body portion 2 having a curved shape suitable for a sickle can be obtained.

After forming the main body portion 2, the cutting tool 1 is obtained by fitting the fixing portion 9 into the handle 3 as shown in FIG.

3. 3. Action effect According to the blade manufacturing method described above, the body piece 50 having a thickness larger than that of the cutting edge piece 70 is made of a metal such as aluminum having a specific gravity smaller than that of the steel cutting edge piece 70. It is possible to obtain a blade 1 that is lighter than the case where the body piece 50 and the body piece 50 are made of the same material.

Further, since the cutting edge piece 70 is made of a steel material, high hardness and excellent wear resistance can be imparted to the cutting edge piece 70, and a cutting tool with good sharpness can be obtained.

Further, since the cutting edge portion 17 is formed before cutting out each cutting edge piece 70 from the first base material 11, when sharpening is performed after cutting out each cutting edge piece 70 from the first base material 11. In comparison, the man-hours required for blade attachment can be reduced.

Further, since the first base material 11 is subjected to the quenching treatment, the first base material 11 having good strength can be obtained. Further, since the first base material 11 is subjected to the quenching treatment and then the tempering treatment, the first base material 11 having good toughness can be obtained.

Further, after the first base material 11 is tempered, the cutting edge portion 17 is polished with a grindstone whose eyes are finer than the grinding wheel, so that the cutting edge portion 17 blunted by tempering is sharpened. Can be done.

Further, since a laser cutter is used to cut out each body piece 50, each cutting edge piece 70, and the fixing portion 9, the shapes of each body piece 50, each cutting edge piece 70, and the fixing portion 9 can be finished with high accuracy.

Further, by fitting the protrusions 91 to 99 formed on the cutting edge piece 70 into the recesses 81 to 89 formed on the body piece 50, the cutting edge piece 70 and the body piece 50 can be easily integrated. it can.

Further, a plurality of protrusions 91 to 99 are formed on the relatively thick end (opposing edge) of the cutting edge piece 70, and the plurality of protrusions 91 to 99 are formed on the body piece 50. Since it is fitted into the plurality of recesses 81 to 89, sufficient fitting strength can be obtained when the cutting edge piece 70 and the body piece 50 are combined.

Further, in the integration step, since the metal adhesive is injected into the gap between the protrusion and the recess, the bonding strength between the pieces can be increased.

4. Modified Examples The above-described embodiments merely illustrate preferred specific examples of the present invention, and the present invention is not limited to the above-mentioned embodiments.

In the above embodiment, a steel plate is used as the first base material 11, but the material of the first base material 11 is not limited to this, and stainless steel, ceramic, or the like may be used. Further, although an aluminum plate material is used as the second base material 12, the material of the second base material 12 is not limited to this, and other lightweight metals such as titanium may be used.

In the above embodiment, a total of nine plurality of cutting edge pieces 70, which are the first cutting edge pieces 71 to 9th cutting edge pieces 79, are cut out from the two first base materials 11 (11A, 11B), and the two second base materials are used. A case has been described in which a total of nine body pieces 50, which are the first body pieces 51 to the ninth body pieces 59, are cut out from 12 (12A, 12B), but the number of the plurality of cutting edge pieces 70 and the plurality of bodies have been described. The number of part pieces 50 may be less than 9 or more than 9, respectively.

In the above embodiment, each cutting edge piece 70 is cut out from the first base material 11 using a laser, and each body piece 50 and each fixing portion 9 are cut out from the second base material 12, but each cutting edge piece 70 and each body portion are cut out. The method of cutting out the piece 50 and the fixing portion 9 is not limited to the laser, and for example, a method using a press machine having a cutter blade having a shape corresponding to each cutting edge piece 70 or each body piece 50 may be used.

In the above embodiment, protrusions 31 to 38 are provided on the other end side B of the first to eighth body pieces 51 to 58, and recesses 41 to A on one end side A of the second to ninth body pieces 52 to 59. Although 48 is provided, the positional relationship between these protrusions and the recesses may be reversed. That is, a recess may be provided on the other end side B of the first to eighth body pieces 51 to 58, and a protrusion may be provided on one end side A of the second to ninth body pieces 52 to 59. When the protrusion 38 on the other end side B of the ninth body piece 59 is changed to a recess, the recess 49 on the one end side A of the fixing portion 9 is changed to a protrusion.

Further, the first to ninth cutting edge pieces 71 to 79 are provided with protrusions 91 to 99, and the first to ninth body pieces 51 to 59 are provided with recesses 81 to 89. The positional relationship may be reversed. That is, the protrusions 91 to 99 may be provided on the first to ninth body pieces 51 to 59, and the recesses 81 to 89 may be provided on the first to ninth cutting edge pieces 71 to 79.

Further, the shapes of the protrusions and the recesses can be changed in various ways. That is, in the above embodiment, the protrusions 31 to 38, 91 to 99 and the recesses 41 to 48, 81 to 88 are formed in an arc shape, respectively, but the protrusions and the recesses in the present invention are not limited to such a shape. .. For example, the shape of the protrusion may be a shape that protrudes in a T-shape or an L-shape, and the shape of the recess may be a shape that can accept the T-shaped / L-shaped protrusion. .. Further, a corrugated portion in which convex portions and concave portions are repeated along the width direction or the longitudinal direction of the piece may be provided as protrusions and recesses. This also applies to the relationship between the ninth body portion piece 59 and the fixed portion 9.

In the above embodiment, an example of manufacturing a blade 1 (that is, a sickle) having a curved main body 2 and a handle 3 by the manufacturing method of the present invention has been described, but the present invention manufactures various blades other than the sickle. Applicable in some cases.

In the above embodiment, the double-edged type cutting edge portion 17 is formed by processing both sides of the side edges of the first base material 11 for sharpening in the cutting step, but the cutting edge portion is not limited to the double-edged type. A single-edged type that has been sharpened on only one side may be used.

In the above embodiment, the cutting edge pieces 71 to 79 and the body pieces 51 to 59 are integrated to form the sub-assies 21 to 29 as shown in FIG. 5, and the sub-assies 20 and the fixing portion 9 are further integrated. The main body 2 is formed by the above, but the order in which the pieces are integrated is not limited to this. For example, the body pieces 50 are integrated first to form the body 5 of FIG. 1, and the cutting edge pieces 70 are integrated to form the cutting edge 7 of FIG. 1, and then the body 5 and the cutting edge 7 are formed. And the fixing portion 9 may be integrated to form the main body portion 2.

In the above embodiment, each cutting edge piece 70, each body piece 50, and the fixing part 9 are fixed by using a metal adhesive when they are integrated in the integration step, but each cutting edge piece 70, each body piece 50. And the method of fixing the fixing portion 9 is not limited to this. For example, a method may be used in which each cutting edge piece 70, each body piece 50, and the fixing portion 9 are integrated in a cooled state, returned to room temperature as it is, and fixed by thermal expansion.

Needless to say, various design changes can be made within the scope of the claims of the present invention.

1 Blade 11 1st base material 12 2nd base material 50 Body piece 51 (1st) Body piece ::
59 (9th) Body piece 70 Cutting edge piece 71 (1st) Cutting edge piece ::
79 (9th) Cutting edge piece 81 (of the 1st body piece) Recessed ::
89 Concave part 91 (of the 9th body piece) Projection 91 (of the 1st cutting edge piece) ::
99 Protrusion 171a (of the 9th cutting edge piece) Cutting edge (of the 1st cutting edge body) ::
179a (of the 9th cutting edge body) Cutting edge 171b (of the 1st cutting edge body) edge (opposing edge)
::
179b (opposite edge) of the 9th cutting edge body

Claims (8)

A first cutting step of cutting out a cutting edge piece having a shape extending from a plate-shaped first base material in a predetermined direction and gradually decreasing in thickness from one to the other in the width direction orthogonal to the predetermined direction.
From the plate-shaped second base material having a specific gravity smaller than that of the first base material, it has substantially the same thickness as the facing edge portion which is the edge portion on the thicker side of the cutting edge piece and is fitted with the facing edge portion. The second cutting process, which cuts out the body piece having a shape that can be fitted,
A method for manufacturing a cutting tool, which comprises an integration step of fitting the cutting edge piece and the body piece to each other and integrating them. In the method for manufacturing a cutting tool according to claim 1,
In the first cutting step, a plurality of protrusions are formed on the facing edges of the cutting edge piece.
In the second cutting step, a plurality of recesses that can be fitted with the protrusions are formed on one side edge of the body piece.
In the integration step, a method for manufacturing a cutting tool, in which the cutting edge piece and the body piece are integrated by fitting the protrusion into the recess. In the method for manufacturing a cutting tool according to claim 2,
In the integration step, a method for manufacturing a cutting tool, in which an adhesive is injected into a gap between the protrusion and the recess when the protrusion is fitted into the recess. In the method for manufacturing a cutting tool according to any one of claims 1 to 3,
In the first cutting step, a plurality of the cutting edge pieces are cut out from a plurality of regions adjacent to each other in the longitudinal direction of the first base material.
In the second cutting step, a plurality of the body pieces are cut out from a plurality of regions adjacent to each other in the longitudinal direction of the second base material, and the body pieces are formed into a shape that can be fitted to each other.
In the integration step, the plurality of cutting edge pieces and the plurality of body pieces are fitted to each other and the adjacent body pieces are fitted to each other. A method of manufacturing blades that integrates with. In the method for manufacturing a cutting tool according to claim 4,
A method for manufacturing a cutting tool, in which a plurality of cutting edge pieces are combined so that an angle formed by adjacent cutting edges is less than 180 degrees in the integration step when the edge on the thin side of the cutting edge piece is used as the cutting edge. In the method for manufacturing a cutting tool according to claim 4 or 5.
Further including a cutting step of processing a region of the first base material located outside from the middle portion in the width direction so that the thickness becomes thinner toward the outside in the width direction.
In the first cutting step, a method for manufacturing a blade, in which a plurality of cutting edge pieces are cut out so as to include a part of a region machined by the cutting step. In the method for manufacturing a cutting tool according to claim 6,
After the cutting step, a heat treatment step of applying a heat treatment to the first base material and a heat treatment step
A method for manufacturing a blade, further comprising a polishing step of polishing a region processed by the cutting step between the heat treatment step and the first cutting step. In the method for manufacturing a cutting tool according to any one of claims 1 to 7.
In the first cutting step, each cutting edge piece is cut out by laser processing.
In the second cutting step, a method for manufacturing a cutting tool, in which each body piece is cut out by laser processing.