How knives are made

Abstract

To provide a manufacturing method for a kitchen knife capable of maintaining a state in which the faces of a mouthpiece and a handle are butted against each other without using a jig until the core and the handle are bonded with an adhesive. [Solution] A method for manufacturing a kitchen knife includes inserting an attachment member (50) into an insertion hole (31) so that a press-fit space (S) extends in the longitudinal direction, and after the attachment member (50) has been inserted into the insertion hole (31), injecting adhesive (32) into the insertion hole (31) and inserting a core (23) into the insertion hole (31) until the opposing faces of the ferrule and the handle (30) are butted together. The method for manufacturing a kitchen knife includes pressing a third extension portion (233) into the press-fit space (S) to expand the attachment member (50) while pressing the attachment member (50) against the inner surface (33) of the handle (30) and the outer surface (23a) of the core (23) to form a retaining portion (40) until the opposing faces of the ferrule and the handle (30) are butted together.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a kitchen knife. [Background technology]

[0002] Generally, a kitchen knife comprises a blade portion and a handle portion. The blade portion comprises a blade body, a ferrule integral with the blade body, and a tang extending from the ferrule. The handle portion has an insertion hole into which the tang is housed. In the kitchen knife, the tang is inserted into the insertion hole, and the ferrule and the handle portion are butted against each other. In the kitchen knife, the tang and the handle portion are bonded together with an adhesive filled in the insertion hole, as disclosed in Patent Document 1, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3218950 Summary of the Invention [Problem to be solved by the invention]

[0004] In a manufacturing method for a kitchen knife in which the core and the handle are bonded with adhesive, a special jig must be used to keep the faces of the ferrule and the handle butted together until the core and the handle are bonded with adhesive. [Means for solving the problem]

[0005] A method of manufacturing a kitchen knife that solves the above problems includes inserting a core extending from a ferrule of a blade portion into an insertion hole extending in the longitudinal direction of a handle portion, and preventing the core from coming out of the handle portion in the longitudinal direction by a retaining portion provided inside the handle portion, and bonding the core and the handle portion with an adhesive filled in the insertion hole, and facing the ferrule and the handle portion abutting against each other, and a press-fitting space is formed into which the axial tip of the core is press-fitted, and before the tip is press-fitted, the insert hole is inserted into the insertion hole. and inserting the mounting member having dimensions that allow insertion into the insertion hole so that the press-fit space extends in the longitudinal direction of the handle portion. After the mounting member has been inserted into the insertion hole, injecting the adhesive into the insertion hole and inserting the core into the insertion hole until the opposing faces of the nozzle and the handle portion are butted together, the tip end is pressed into the press-fit space to expand the mounting member, and the mounting member is pressed against the inner surface of the handle portion that forms the insertion hole and the outer surface of the core until the opposing faces of the nozzle and the handle portion are butted together, thereby forming the retaining portion.

[0006] In a method for manufacturing a kitchen knife, it is preferable to use an air vice to insert the core into the insertion hole until the facing surfaces of the ferrule and the handle are butted together. In a method for manufacturing a kitchen knife, the core may be provided with a rotation regulating portion on the peripheral surface of the core near the ferrule in the axial direction, and the rotation regulating portion may be pressed into the periphery of the insertion hole on the side of the handle facing the ferrule before the faces of the ferrule and the handle are butted together.

[0007] In the method for manufacturing a kitchen knife, the mounting member may be a split pin that extends in an arc shape around the central axis of the mounting member, has a shape that forms the press-fit space inside the arc-shaped portion, and has split surfaces that face each other in the circumferential direction of the arc-shaped portion.

[0008] In the method for manufacturing a kitchen knife, the tip portion may preferably have a tapered portion whose diameter decreases toward the tip of the core. [Effects of the Invention]

[0009] The present invention can maintain the face-to-face state of the mouthpiece and the handle without using a jig until the core and the handle are bonded with an adhesive. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an exploded perspective view showing a kitchen knife. [Figure 2] FIG. 2 is a partial perspective view showing the blade portion. [Figure 3] FIG. 3 is a cross-sectional view showing a kitchen knife. [Figure 4] FIG. 4 is a cross-sectional view showing the rotation restricting portion and the handle portion. [Figure 5] FIG. 5 shows the mounting member before and after expansion. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which the mounting member is inserted into the insertion hole. [Figure 7] FIG. 7 is a cross-sectional view of a state before the third extension portion is inserted into the press-fitting space. [Figure 8] FIG. 8 is a cross-sectional view showing a state in which the third extension portion is press-fitted into the press-fitting space. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Embodiment] Hereinafter, one embodiment of a method for manufacturing a kitchen knife will be described. <Knife components> As shown in Fig. 1, the knife 10 includes a blade portion 20 and a long handle portion 30, and as shown in Fig. 3, a retaining portion 40. The retaining portion 40 is formed by an attachment member 50. The longitudinal direction of the handle portion 30 is simply referred to as the longitudinal direction X. Note that the longitudinal direction X of the handle portion 30 coincides with the longitudinal direction of the knife 10 and the blade portion 20, and therefore the longitudinal direction of the knife 10 and the blade portion 20 is also referred to as the longitudinal direction X. Furthermore, the direction perpendicular to the longitudinal direction X is referred to as the orthogonal direction Y of the knife 10, the blade portion 20, and the handle portion 30.

[0012] <Blade> 1 and 2, the blade portion 20 includes a blade body 21, a mouthpiece 22 integral with the blade body 21, and a core 23 extending from the mouthpiece 22. The material of the blade portion 20 is a metal material. The blade portion 20 is formed by casting. However, the material of the blade portion 20 can be changed to any material such as ceramics.

[0013] The ferrule 22 is provided at the base of the blade body 21. The ferrule 22 is cylindrical and opens closer to the core 23 than the blade body 21. The ferrule 22 has a ferrule end surface 22a that faces the handle 30. As shown in FIG. 3 , the ferrule end surface 22a is located on an imaginary plane M1 that extends in the orthogonal direction Y.

[0014] 3 and 4 , the core 23 extends from the inner bottom surface of the mouthpiece 22 in the longitudinal direction X of the blade portion 20. The core 23 includes a first extending portion 231 extending from the inner bottom surface of the mouthpiece 22 in the longitudinal direction X, a second extending portion 232 extending from the first extending portion 231 in the longitudinal direction X, a third extending portion 233 extending from the second extending portion 232 in the longitudinal direction X, and a plurality of rotation restricting portions 24 provided on the first extending portion 231.

[0015] The first extension portion 231 is a portion of the core 23 that extends from the inner bottom surface of the nozzle 22 to slightly extend beyond the nozzle end surface 22a. The second extension portion 232 is a portion located between the first extension portion 231 and the third extension portion 233. The third extension portion 233 is the tip portion of the core 23.

[0016] The first extension portion 231 is formed by providing a rotation restricting portion 24 on the circumferential surface of a cylindrical portion. The second extension portion 232 is cylindrical. The third extension portion 233 is almost entirely cylindrical. The third extension portion 233, which becomes the tip portion of the core 23, has a tapered portion 233a whose diameter decreases toward the tip of the core 23. The tapered portion 233a is formed by chamfering the portion that becomes the tip of the core 23.

[0017] The diameter of the first extension portion 231 excluding the rotation restricting portion 24 is defined as a first diameter N1. The diameter of the second extension portion 232 is defined as a second diameter N2. The diameter of the third extension portion 233 excluding the tapered portion 233a is defined as a third diameter N3, and the diameter of the tapered portion 233a is defined as a fourth diameter N4.

[0018] The first diameter N1 is larger than the second diameter N2 to the fourth diameter N4. The third diameter N3 is smaller than the second diameter N2. The fourth diameter N4 gradually becomes smaller toward the tip of the tapered portion 233a.

[0019] Each rotation restricting portion 24 is a protrusion extending in the longitudinal direction X. The multiple rotation restricting portions 24 are arranged at equal intervals in the circumferential direction of the first extending portion 231. Each rotation restricting portion 24 is provided at a position in the longitudinal direction X of the first extending portion 231 that is slightly closer to the second extending portion 232 than the base end face 22a. The dimension of the first extending portion 231 at the location where the rotation restricting portion 24 is formed is slightly larger than the hole diameter H of the insertion hole 31, which will be described later.

[0020] <Handle> The material of the handle 30 is preferably a material that allows the rotation restricting portion 24 to bite into the handle 30, and therefore the material of the handle 30 is preferably wood or resin. However, if the rotation restricting portion 24 is omitted, the material of the handle 30 may be a metal material, or the material of the handle 30 may be wood or resin while omitting the rotation restricting portion 24.

[0021] 3, the handle 30 has a first end face 30a at one end face in the longitudinal direction X and a second end face 30b at the other end face in the longitudinal direction X. An imaginary plane M2 passing through the first end face 30a is a plane extending in the perpendicular direction Y. The second end face 30b of the handle 30 in the longitudinal direction X can be formed by attaching a butt cap or by the handle 30 itself, and therefore the shape of the second end face 30b can be changed as desired.

[0022] The handle 30 has an insertion hole 31 that opens to the first end face 30a and has a bottom face 30c. The insertion hole 31 has a first hole portion 31a extending from the first end face 30a in the longitudinal direction X, and a second hole portion 31b that is closer to the second end face 30b than the first hole portion 31a. The cross section of the insertion hole 31 is circular. The insertion hole 31 is formed by drilling the handle 30 from the first end face 30a.

[0023] In the insertion hole 31, the hole diameter H of the first hole portion 31a is constant from the first end face 30a to just before the bottom face 30c. The hole diameter H of the second hole portion 31b gradually decreases from the boundary with the first hole portion 31a toward the second end face 30b.

[0024] The first diameter N1 of the first extension portion 231 excluding the rotation restricting portion 24 is slightly smaller than the hole diameter H of the first hole portion 31a. The first diameter N1 is approximately 0.1 millimeters (mm) smaller than the hole diameter H of the first hole portion 31a. Furthermore, the dimension of the first extension portion 231 at the location where the rotation restricting portion 24 is formed is slightly larger than the hole diameter H of the first hole portion 31a. The second diameter N2 of the second extension portion 232 and the third diameter N3 and fourth diameter N4 of the third extension portion 233 are each smaller than the hole diameter H of the first hole portion 31a.

[0025] <Prevention part> In the kitchen knife 10, the core 23 extending from the ferrule 22 of the blade section 20 is inserted into the insertion hole 31 extending in the longitudinal direction X of the handle 30. As shown in Figures 3 and 5, the retaining portion 40 is pressed against the outer surface 23a of the core 23 at the third extension portion 233 and against the inner surface 33 aligned with the outer surface 23a in the perpendicular direction Y. In the kitchen knife 10, the retaining portion 40 provided inside the handle 30 prevents the core 23 from coming out of the handle 30 in the longitudinal direction X.

[0026] <Adhesive> The insertion hole 31 is filled with adhesive 32. The adhesive 32 adheres to the inner surface 33 of the handle 30 and the outer surface 23a of the core 23 that are not pressed against the retaining portion 40, and also adheres the core 23 to the handle 30. Therefore, in the kitchen knife 10, the core 23 and the handle 30 are adhered by the adhesive 32 filled in the insertion hole 31.

[0027] <Knife> In the kitchen knife 10 having the above-described blade portion 20, handle portion 30, adhesive 32, and retaining portion 40, the ferrule end surface 22a, which faces the ferrule 22 and handle portion 30, and the first end surface 30a are butted together. Therefore, there is no gap between the ferrule end surface 22a and the first end surface 30a.

[0028] In the kitchen knife 10, each rotation restricting portion 24 is press-fitted into the first end face 30a, which faces the ferrule end face 22a, at a position around the insertion hole 31. Specifically, as shown in FIG. 4, each rotation restricting portion 24 is wedged into the handle 30. The positions at which the rotation restricting portions 24 are press-fitted into the handle 30 are formed at equal intervals around the circumference of the insertion hole 31. The press-fitting of the rotation restricting portions 24 into the handle 30 restricts the rotation of the core 23 around the circumference of the insertion hole 31.

[0029] <Mounting parts> 1 and 5, the mounting member 50 is a component that forms the retaining portion 40. Note that in Fig. 5, the dimensions of the mounting member 50 are exaggerated to facilitate explanation of the enlarged view of the mounting member 50. The mounting member 50 is made of a metal material.

[0030] 1, the mounting member 50 is substantially cylindrical. The mounting member 50 extends in an arc shape centered on the central axis L of the mounting member 50, and has a shape that forms a press-fit space S inside the arc-shaped portion into which the third extension portion 233 of the core 23 is press-fitted.

[0031] When viewed from the direction in which the central axis L extends, the mounting member 50 is C-shaped. The direction in which the arc of the mounting member 50 extends, i.e., the direction surrounding the press-fit space S, is defined as the circumferential direction of the mounting member 50. The mounting member 50 has split surfaces 52 located at both ends in the circumferential direction and facing each other at a distance in the circumferential direction. Each split surface 52 is uneven in the axial direction of the mounting member 50. Thus, the mounting member 50 is a split pin that is open at both ends in the direction in which the central axis L extends and has split surfaces 52 facing each other in the circumferential direction of the arc-shaped portion. The mounting member 50 has split surfaces 52 that allow it to be easily expanded and contracted.

[0032] 5, when the mounting member 50 is viewed in the direction in which the central axis L extends, the inner surface of the mounting member 50 is formed along a circular imaginary inner circumferential circle C1. When the mounting member 50 is viewed in the direction in which the central axis L extends, the outer surface of the mounting member 50 is formed along a circular imaginary outer circumferential circle C2. The diameter of the imaginary inner circumferential circle C1 is defined as the inner diameter r1 of the mounting member 50, and the diameter of the imaginary outer circumferential circle C2 is defined as the outer diameter r2 of the mounting member 50.

[0033] The inner diameter r1 of the mounting member 50 is slightly larger than the fourth diameter N4 of the tapered portion 233a of the third extension portion 233, and the inner diameter r1 is smaller than the third diameter N3 of the third extension portion 233. The outer diameter r2 of the mounting member 50 is slightly smaller than the hole diameter H of the insertion hole 31. The mounting member 50 is sized so that it can be inserted into the insertion hole 31 with the direction in which the central axis L of the mounting member 50 extends aligned with the longitudinal direction X of the handle portion 30. Thus, the mounting member 50 forms a press-fitting space S into which the third extension portion 233, which is the axial tip end of the core 23, is press-fitted, and has dimensions that allow the third extension portion 233 to be inserted into the insertion hole 31 before it is press-fitted.

[0034] The retaining portion 40 is formed by press-fitting the third extension portion 233 of the core 23 into the press-fit space S inside the mounting member 50. When the third extension portion 233 is press-fitted into the mounting member 50, the mounting member 50 expands so as to increase the distance between the opposing split surfaces 52 in the circumferential direction. The inner diameter R1 of the retaining portion 40 formed by the expansion of the mounting member 50 is larger than the inner diameter r1 of the mounting member 50. The outer diameter R2 of the retaining portion 40 is also larger than the outer diameter r2 of the mounting member 50. The inner diameter R1 of the retaining portion 40 is the same as the third diameter N3 of the third extension portion 233. The outer diameter R2 of the retaining portion 40 is the same as the hole diameter H of the first hole 31a. As a result, the mounting member 50 is pressed against the inner surface 33 of the handle 30 and the outer surface 23a of the core 23, forming the retaining portion 40.

[0035] The length of the third extension portion 233 in the longitudinal direction X is longer than the length of the mounting member 50 in the direction along the central axis L. The length of the mounting member 50 along the central axis L is preferably 15% to 45%, and more preferably 20% to 30%, of the overall length of the core 23 in the longitudinal direction X. By setting it in this manner, when the mounting member 50 expands over the entire length along the direction along the central axis L to form the retaining portion 40, it is possible to prevent the core 23 from slipping out of the handle portion 30 in the longitudinal direction X.

[0036] <Knife manufacturing method> As shown in Figure 6, the worker inserts the attachment member 50 into the insertion hole 31 of the handle 30. At this time, the worker inserts the attachment member 50 into the insertion hole 31 until the attachment member 50 reaches the boundary between the first hole portion 31a and the second hole portion 31b. The worker also inserts the attachment member 50 into the insertion hole 31 so that the press-fit space S extends in the longitudinal direction X of the handle 30. Therefore, the manufacturing method of the knife 10 includes inserting the attachment member 50 into the insertion hole 31 so that the press-fit space S extends in the longitudinal direction X of the handle 30.

[0037] 7, the blade portion 20 is held by the first holding portion 61 of the air vice 60, and the handle portion 30 is held by the second holding portion 62 of the air vice 60. The first holding portion 61 and the second holding portion 62 are each biased by air pressure in a direction that brings the held blade portion 20 and handle portion 30 closer to each other. The blade portion 20 and handle portion 30 held by the air vice 60 are held with the tapered portion 233a of the third extension portion 233 facing the insertion hole 31.

[0038] Then, after injecting adhesive 32 into insertion hole 31, air vice 60 is driven to urge first holding portion 61 and second holding portion 62 toward each other. Then, core 23 is inserted into insertion hole 31 from tapered portion 233a of third extension portion 233. Therefore, the manufacturing method of knife 10 includes using air vice 60 to insert core 23 into insertion hole 31 until ferrule end surface 22a and first end surface 30a are butted against each other.

[0039] As shown in FIG. 8 , the third extension portion 233 is inserted into the press-fit space S, starting with the tapered portion 233a. After the tapered portion 233a is inserted into the press-fit space S, the portions other than the tapered portion 233a are press-fitted into the inside of the mounting member 50 and into the press-fit space S. At this time, even if the mounting member 50 is not inserted up to the boundary between the first hole portion 31a and the second hole portion 31b, the mounting member 50 is pushed toward the second hole portion 31b by the insertion of the core 23, and the mounting member 50 moves to the boundary between the first hole portion 31a and the second hole portion 31b. Then, as the third extension portion 233 is press-fitted into the inside of the mounting member 50, i.e., into the press-fit space S, the mounting member 50 expands in the orthogonal direction Y by the third extension portion 233.

[0040] 3, when mouthpiece end face 22a and first end face 30a come into contact with each other and butt together, further insertion of core 23 into insertion hole 31 is restricted. Third extension portion 233 is press-fitted into the inside of mounting member 50, i.e., press-fit space S, and mounting member 50 expands in orthogonal direction Y, whereby outer surface 23a of third extension portion 233 is pressed against the inner surface of mounting member 50, and the outer surface of mounting member 50 is pressed against inner surface 33 of handle portion 30, and thus retaining portion 40 is formed by mounting member 50.

[0041] Therefore, the manufacturing method of the kitchen knife 10 includes inserting the attachment member 50 into the insertion hole 31, injecting adhesive 32 into the insertion hole 31, and inserting the core 23 into the insertion hole 31 until the ferrule end face 22a and the first end face 30a are butted together. Then, the manufacturing method of the kitchen knife 10 includes press-fitting the third extension portion 233 into the press-fit space S to expand the attachment member 50, and pressing the attachment member 50 against the inner surface 33 of the handle 30 and the outer surface 23a of the core 23, which form the insertion hole 31, to form the retaining portion 40, before the ferrule end face 22a and the first end face 30a are butted together. In this embodiment, the third extension portion 233 is press-fitted into the press-fit space S to expand the attachment member 50 and form the retaining portion 40, and at the same time, the ferrule end face 22a and the first end face 30a are butted together.

[0042] Furthermore, the manufacturing method of the knife 10 includes, before the ferrule end face 22a and the first end face 30a are butted together, in this embodiment, pressing the rotation regulating portion 24 around the insertion hole 31 in the first end face 30a just before the ferrule end face 22a and the first end face 30a are butted together.

[0043] As a result, the pressing force of the retaining portion 40 prevents the core 23 from coming out of the handle portion 30 in the longitudinal direction X. Furthermore, the rotation-regulating portion 24 bites into the periphery of the insertion hole 31 in the first end face 30a, thereby preventing the core 23 from rotating in the circumferential direction of the insertion hole 31. As a result, the ferrule end face 22a and the first end face 30a are maintained in abutted relationship. Note that the manufacturing method of the kitchen knife 10 may involve maintaining the ferrule end face 22a and the first end face 30a in abutted relationship while the core 23 and the handle portion 30 are held by the air vice 60, or may involve removing the blade portion 20 and the handle portion 30 from the air vice 60 and maintaining the ferrule end face 22a and the first end face 30a in abutted relationship.

[0044] Then, until adhesive 32 hardens and core 23 and handle 30 are bonded together, retaining portion 40 maintains ferrule end surface 22a and first end surface 30a in a butted state. Once adhesive 32 hardens and core 23 and handle 30 are bonded together, knife 10 is completed.

[0045] According to the above embodiment, the following effects can be obtained. (1) In the manufacturing method of the kitchen knife 10, the attachment member 50 that forms the retaining portion 40 is inserted into the insertion hole 31, and then the core 23 is inserted into the insertion hole 31 into which the adhesive 32 has been poured. The third extension portion 233 is then press-fit into the press-fit space S inside the attachment member 50, causing the attachment member 50 to expand and form the retaining portion 40. The retaining portion 40 prevents the core 23 from slipping out of the handle 30 in the longitudinal direction X, so the ferrule end face 22a and the first end face 30a can be maintained in abutted relationship without using a dedicated jig. Therefore, in the manufacturing method of the kitchen knife 10, the ferrule 22 and the handle 30 can be maintained in a butted relationship without using a jig until the core 23 and the handle 30 are bonded with the adhesive 32.

[0046] (2) In the manufactured kitchen knife 10, the core 23 is prevented from slipping out of the handle portion 30 in the longitudinal direction X by the retaining portion 40 in addition to the adhesive 32. One method for manufacturing a kitchen knife that prevents the core 23 from slipping out of the handle portion 30 in the longitudinal direction X is to fasten the core 23 to the handle portion 30 with rivets. However, the manufacturing method of this embodiment can prevent the core 23 from slipping out of the handle portion 30 without using rivets. As a result, it is not necessary to form rivet holes in the core 23 or to form a flat surface on the handle portion 30 for rivet fastening. Therefore, the manufacturing method of this embodiment makes it easier to manufacture the kitchen knife 10 and reduces design restrictions on the handle portion 30 compared to manufacturing methods that use rivets. In addition, the manufacturing method of this embodiment does not require forming matching rivet holes in the core 23 and the handle portion 30 to fasten them with rivets, so the kitchen knife 10 can be manufactured without high dimensional accuracy. Furthermore, according to the manufacturing method of this embodiment, when replacing the handle portion 30, there is no need to form rivet holes in the handle portion 30 or to crimp the rivets, so the handle portion 30 can be easily replaced.

[0047] (3) In the manufacturing method for the kitchen knife 10, the attachment member 50 is used to form the retaining portion 40 to prevent the core 23 from slipping out of the handle 30 in the longitudinal direction X. After the attachment member 50 is inserted into the insertion hole 31, the third extension portion 233 of the core 23 is press-fitted into the attachment member 50, thereby expanding the attachment member 50. Therefore, the attachment member 50 only needs to have a size that allows it to be inserted into the insertion hole 31 and that allows the third extension portion 233 to be press-fitted into it. In particular, even if a manufacturing error occurs in the hole diameter H of the insertion hole 31 or the outer diameter r2 of the attachment member 50, the attachment member 50 can be easily inserted into the insertion hole 31. Therefore, in the manufacturing method for the kitchen knife 10, the attachment member 50, the insertion hole 31, and the core 23 do not need to have high dimensional precision, which reduces the manufacturing cost of the kitchen knife 10.

[0048] (4) As a method for preventing the core 23 from slipping out of the handle 30 in the longitudinal direction X, for example, it is possible to make the diameter of the core 23 equal to the diameter of the insertion hole 31 and press the core 23 directly into the inside of the handle 30. However, this method requires that the core 23 be manufactured with high dimensions so that it can be press-fitted into the inside of the handle 30. In contrast, in this embodiment, it is sufficient to simply enlarge the mounting member 50, so that only the third extension portion 233, which is a part of the core 23 in the longitudinal direction X, needs to have dimensional precision. Therefore, the manufacturing method of the knife 10 can prevent the core 23 from slipping out of the handle 30 even if it does not have high dimensional precision.

[0049] (5) The attachment member 50 that forms the retaining portion 40 is a split pin having a split surface 52. Compared to when the attachment member 50 is cylindrical, the attachment member 50 is more likely to expand when the third extension portion 233 is pressed into the attachment member 50, and the amount of expansion is greater. Therefore, when compared to when a cylindrical attachment member 50 is used, the method of manufacturing the knife 10 using the split pin-shaped attachment member 50 makes it easier to form the retaining portion 40 and to ensure that the retaining function is exhibited.

[0050] (6) The core 23 includes a rotation restricting portion 24. When the ferrule end face 22a and the first end face 30a are abutted against each other, the rotation restricting portion 24 bites into the handle 30. This bite restricts rotation of the core 23 in the circumferential direction of the insertion hole 31. Therefore, according to the manufacturing method of the knife 10, the rotation of the core 23 can be restricted without using a dedicated jig, and the abutting state of the ferrule end face 22a and the first end face 30a can be reliably maintained.

[0051] (7) The core 23 has a rotation restricting portion 24. When the ferrule end face 22a and the first end face 30a are abutted against each other, the rotation restricting portion 24 bites into the handle 30. This biting restricts movement of the core 23 in the orthogonal direction Y of the handle 30. Therefore, according to the manufacturing method of the knife 10, movement of the core 23 in the orthogonal direction Y can be restricted without using a dedicated jig, and the abutting state of the ferrule end face 22a and the first end face 30a can be reliably maintained.

[0052] (8) The manufacturing method of the kitchen knife 10 uses an air vice 60 to press-fit the third extension portion 233 into the attachment member 50. The air vice 60 can precisely control the biasing force used to press-fit the third extension portion 233 into the attachment member 50, and therefore can accurately press-fit the third extension portion 233 into the attachment member 50. Furthermore, compared to when the third extension portion 233 is pressed into the attachment member 50 by hitting it with a hammer or the like, the load applied to the handle 30 and the blade portion 20 can be reduced.

[0053] (9) In the manufacturing method of the kitchen knife 10, the attachment member 50 is expanded with the core 23 to form the retaining portion 40, thereby preventing the core 23 from slipping out of the handle 30 in the longitudinal direction X. Therefore, according to the manufacturing method of the kitchen knife 10, by standardizing the dimensions of the core 23, the hole diameter H of the insertion hole 31, and the dimensions of the attachment member 50, the blade portion 20 and the handle 30 can be fixed and retained even if the shape of the blade body 21 is different.

[0054] (10) If the mounting member 50 can be expanded in the axial direction by a specified dimension, it can function as the retaining portion 40. Therefore, the axial dimension of the mounting member 50 is set to be larger than the specified dimension.

[0055] (11) The core 23 has a tapered portion 233a at the tip of the third extending portion 233. Therefore, the third extending portion 233 can be easily press-fitted into the mounting member 50 by the tapered portion 233a. [Example of change] The embodiment can be modified as follows: The embodiment and the following modifications can be combined with each other to the extent that they are not technically inconsistent.

[0056] The mounting member 50 may be cylindrical and not have the split surface 52 . The shape of the mounting member 50 may be changed as appropriate as long as the third extending portion 233 can be pressed against the inner surface 33 of the insertion hole 31 and the outer surface 23a of the core 23 to form the retaining portion 40.

[0057] The rotation restricting portion 24 may be omitted. Alternatively, the number of the rotation restricting portions 24 may be one or may be any number other than four. The third extending portion 233 may be press-fitted into the inside of the mounting member 50 by hitting it with a hammer or the like.

[0058] The core 23 may have a constant diameter or may be formed in a rectangular column shape, except for the third extension portion 233 that is press-fitted into the mounting member 50 . [Explanation of symbols]

[0059] S...press-fitting space, X...longitudinal direction, 10...knife, 20...blade portion, 22...ferrule, 22a...ferrule end surface forming the opposing side, 23...core, 23a...outer surface, 24...rotation control portion, 30...handle portion, 30a...first end surface forming the opposing side, 31...insertion hole, 32...adhesive, 33...inner surface, 40...anti-slip portion, 50...mounting member, 52...splitting surface, 60...air vice, 233...third extension portion as tip.

Claims

1. A core extending from a ferrule of the cutting part is inserted into an insertion hole extending in the longitudinal direction of the handle, and a retaining part provided inside the handle prevents the core from coming out of the handle in the longitudinal direction, A method for manufacturing a kitchen knife, wherein the core and the handle are bonded together by an adhesive filled in the insertion hole, and the ferrule and the handle are butted against each other at their opposing faces, forming a press-fitting space into which the axial tip end of the core is press-fitted, and inserting an attachment member having a dimension that allows it to be inserted into the insertion hole into the insertion hole before the tip end is press-fitted, so that the press-fitting space extends in the longitudinal direction of the handle portion; After the mounting member is inserted into the insertion hole, the adhesive is injected into the insertion hole, and the core is inserted into the insertion hole until the opposing faces of the mouthpiece and the handle portion are butted against each other, A method of manufacturing a kitchen knife, wherein the tip portion is press-fitted into the press-fit space to expand the attachment member before the opposing faces of the ferrule and the handle portion are butted together, and the attachment member is pressed against the inner surface of the handle portion that forms the insertion hole and the outer surface of the core to form the retaining portion.

2. The method for manufacturing a kitchen knife according to claim 1, wherein the core is inserted into the insertion hole using an air vice until the facing surfaces of the ferrule and the handle are butted against each other.

3. the core includes a rotation restricting portion on a peripheral surface of the core near the mouthpiece in the axial direction, 3. The method for manufacturing a kitchen knife according to claim 1, wherein the rotation restricting portion is press-fitted around the insertion hole on the side of the handle portion facing the ferrule before the faces of the ferrule and the handle portion are butted together.

4. 3. The method for manufacturing a kitchen knife according to claim 1 or 2, wherein the mounting member is a split pin that extends in an arc shape around a central axis of the mounting member, has a shape that forms the press-fit space inside the arc-shaped portion, and has split surfaces that face each other in the circumferential direction of the arc-shaped portion.

5. The method for manufacturing a kitchen knife according to claim 1 or 2, wherein the tip portion has a tapered portion whose diameter decreases toward the tip of the core.

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