Method for manufacturing rod-shaped drawing material, and rod-shaped drawing material

Abstract

To easily arrange a cylindrical body along a shape of an outer peripheral surface of a drawing material even when the drawing material has a complicated shape, and to efficiently manufacture the drawing material.SOLUTION: A manufacturing method of stick-like drawing materials includes the steps of: preparing a pin 92, a cylindrical body 3 with flexibility, an unsolidified drawing material, and a drawing material forming jig 6 with an injection molding hole (a molding hole) for injection-molding the drawing material; making an insertion body including the cylindrical body 3 and the pin 92; inserting the insertion body into the injection molding hole and making a cross-sectional shape of the cylindrical body 3 when being cut by a plane orthogonal to an insertion direction, the direction of inserting the insertion body, follow a cross-sectional shape of the injection molding hole; removing the pin 92 from the injection molding hole, with the cylindrical body 3 disposed in the injection molding hole; filling the inside of the cylindrical body 3 with an unsolidified drawing material; and solidifying the drawing material filling the inside of the cylindrical body 3.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a drawing rod, and to a drawing rod. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2004-141229 describes a paper-wrapping pencil-type cosmetic product that is composed of a cylindrical shaft formed by wrapping paper around it and a rod-shaped core material located inside the cylindrical shaft. The paper has multiple separation lines that are inclined with respect to a predetermined reference line, and the separation lines form numerous strips. The core material can be exposed from the paper-wrapping paper by peeling off the strips. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-141229 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the design of drawing materials, it is desirable to diversify the shapes of drawing materials. However, as with the aforementioned wrapper pencil-type cosmetics, in rod-shaped drawing materials, a cylindrical shaft may be formed by wrapping a wrapper around the outer periphery of a core material. In this case, when the core material has a complex shape, it may not be easy to arrange a cylindrical body such as a wrapper along the shape of the outer periphery of the core material. Therefore, even when the core material has a complex shape, it is desired to easily arrange a cylindrical body along the shape of the outer periphery of the drawing material and to efficiently manufacture rod-shaped drawing materials.

[0005] The present disclosure aims to provide a method for manufacturing a rod-shaped drawing material that can easily arrange a cylindrical body along the shape of the outer surface of the drawing material, even if the drawing material has a complex shape, and that can be manufactured efficiently, and a rod-shaped drawing material. [Means for solving the problem]

[0006] A method for manufacturing a rod-shaped drawing material according to the present disclosure includes the steps of preparing a pin, a flexible cylindrical body, unsolidified drawing material, and a drawing material forming jig having a molding hole for molding the drawing material. The method also includes the steps of inserting the pin into the cylindrical body to create an insert including the cylindrical body and the pin. The method also includes the steps of inserting the insert into the molding hole so that the cross-sectional shape of the cylindrical body when cut along a plane perpendicular to the insertion direction, which is the direction in which the insert is inserted, conforms to the cross-sectional shape of the molding hole. The method also includes the steps of removing the pin from the molding hole while the cylindrical body is placed in the molding hole, filling the cylindrical body with unsolidified drawing material, and solidifying the drawing material filled in the cylindrical body.

[0007] In the method for manufacturing a rod-shaped drawing material according to the present disclosure, an insert including a cylindrical body and a pin is inserted into a molding hole, causing the cross-sectional shape of the cylindrical body to conform to the cross-sectional shape of the molding hole. Then, the cylindrical body is filled with unsolidified drawing material, and the drawing material filled in the cylindrical body is solidified to manufacture the rod-shaped drawing material. Therefore, a drawing material forming jig having a desired cross-sectional shape for the molding hole is prepared, the cross-sectional shape of the cylindrical body is conformed to the cross-sectional shape of the molding hole, and the drawing material is filled inside the cylindrical body having the conformed cross-sectional shape, thereby manufacturing a rod-shaped drawing material having a desired cross-sectional shape. Therefore, even if the cross-sectional shape of the molding hole is a desired complex shape, it is possible to make the cross-sectional shapes of the cylindrical body and drawing material conform to the cross-sectional shape of the molding hole. This allows a drawing material having a cross-sectional shape conforming to the cross-sectional shape of the cylindrical body to be provided inside the cylindrical body placed in the molding hole. Therefore, even if the drawing material has a complex shape, the cylindrical body can be easily positioned along the shape of the outer surface of the drawing material. In this manufacturing method, a cylindrical body is placed in a molding hole, and the cylindrical body is filled with a drawing material to form the drawing material. That is, by filling the cylindrical body with unsolidified drawing material, the cylindrical body can be placed around the drawing material in advance. Therefore, compared to, for example, wrapping a wrapping paper or the like around the outer surface of a solidified drawing material, the drawing material is solidified after being filled into the cylindrical body. This eliminates the need to wrap a cylindrical body around the solidified drawing material, thereby improving the manufacturing efficiency of rod-shaped drawing materials. Therefore, rod-shaped drawing materials can be efficiently manufactured even when the drawing material has a complex shape.

[0008] In the preparing step, a shape-following jig having a shape-following hole into which the insert is inserted may be prepared. This manufacturing method may further include a step of inserting the insert into the shape-following hole of the shape-following jig before inserting the insert into the forming hole in the following step, thereby causing the cross-sectional shape of the cylindrical body to follow the cross-sectional shape of the forming hole. In this case, the cross-sectional shape of the cylindrical body is caused to follow the cross-sectional shape of the forming hole before inserting the insert into the forming hole. By causing the cross-sectional shape of the cylindrical body to follow the cross-sectional shape of the forming hole with the shape-following jig before inserting the insert into the forming hole, the insert can be inserted into the forming hole more smoothly. Therefore, rod-shaped drawing materials can be manufactured more efficiently.

[0009] The cross-sectional shape of the pin when cut on a plane perpendicular to the insertion direction may be similar to the cross-sectional shape of the forming hole. In this case, when preparing the insert, the cross-sectional shape of the tubular body can be changed to be similar to the cross-sectional shape of the forming hole by conforming the cross-sectional shape of the pin, which is similar to the cross-sectional shape of the forming hole. Since the cross-sectional shape of the pin located inside the tubular body is similar to the cross-sectional shape of the forming hole located outside the tubular body, when the insert is inserted into the forming hole, the tubular body is sandwiched between the inner surface of the forming hole and the outer surface of the pin, which have similar cross-sectional shapes, so that the cross-sectional shape of the tubular body can be more smoothly conformed to the cross-sectional shape of the forming hole. Therefore, the cross-sectional shape of the tubular body can be more easily conformed to the cross-sectional shape of the forming hole within the forming hole.

[0010] The molding hole may penetrate the drawing material forming jig from one end to the other end in the insertion direction. The manufacturing method for a rod-shaped drawing material may further include a step of placing a tip forming jig at the other end of the drawing material forming jig before the filling step. The tip forming jig may have a tip forming hole that extends further in the insertion direction than the cylindrical body placed in the forming hole. In this case, when the cylindrical body placed in the forming hole is filled with unsolidified drawing material, the tip forming hole of the tip forming jig placed at the other end of the drawing material forming jig is also filled with unsolidified drawing material. By solidifying the drawing material in this state, a tip of the drawing material that extends further in the insertion direction than the cylindrical body can be formed. Therefore, the tip of the solidified rod-shaped drawing material protrudes from the cylindrical body, allowing the rod-shaped drawing material to be used immediately without having to roll up the cylindrical body.

[0011] The rod-shaped drawing material according to the present disclosure includes a drawing material extending in one direction and a flexible cylindrical body covering the outer periphery of the drawing material, and the cross-sectional shape of the drawing material when cut along a plane perpendicular to the one direction includes a recess that is recessed toward the inside of the drawing material.

[0012] In the rod-shaped drawing material according to the present disclosure, the cross-sectional shape of the drawing material when cut in a plane perpendicular to one direction includes a recess that is recessed inward of the drawing material. A drawing material having a cross-sectional shape similar to the cross-sectional shape when cut in a plane perpendicular to one direction is provided inside a cylindrical body having the inward recess. Therefore, even if the drawing material has a complex shape, the cylindrical body can be arranged to cover the outer peripheral surface of the drawing material, allowing for efficient production of rod-shaped drawing materials.

[0013] That is, the gist of the present disclosure lies in the following [1] to [5]. [1] A method for manufacturing a rod-shaped drawing material, comprising the steps of: preparing a pin, a flexible cylindrical body, unsolidified drawing material, and a drawing material forming jig having a forming hole for forming the drawing material; inserting the pin into the cylindrical body to produce an insert including the cylindrical body and the pin; inserting the insert into the forming hole so that the cross-sectional shape of the cylindrical body when cut on a plane perpendicular to the insertion direction, which is the direction in which the insert is inserted, conforms to the cross-sectional shape of the forming hole; removing the pin from the forming hole with the cylindrical body placed in the forming hole; filling the cylindrical body with unsolidified drawing material; and solidifying the drawing material filled in the cylindrical body. [2] The method for manufacturing a rod-shaped drawing material according to [1] further includes a step in which the preparing step includes preparing a shape-following jig having a shape-following hole into which the insert is inserted, and in the following step, before inserting the insert into the forming hole, inserting the insert into the shape-following hole of the shape-following jig to cause the cross-sectional shape of the cylindrical body to follow the cross-sectional shape of the forming hole. [3] A method for manufacturing a rod-shaped drawing material according to [1] or [2], wherein the cross-sectional shape of the pin when cut along a plane perpendicular to the insertion direction is similar to the cross-sectional shape of the forming hole. [4] A method for producing a rod-shaped drawing material according to any one of [1] to [3], wherein the forming hole penetrates the drawing material forming jig from one end to the other end in the insertion direction, and the method further comprises, before the filling step, a step of placing a tip forming jig at the other end of the drawing material forming jig, the tip forming jig having a tip forming hole that extends further in the insertion direction than the cylindrical body placed in the forming hole. [5] A rod-shaped drawing material comprising a drawing material extending in one direction and a flexible cylindrical body covering the outer surface of the drawing material, wherein the cross-sectional shape of the drawing material when cut along a plane perpendicular to the one direction includes a recess that is recessed toward the inside of the drawing material. [Effects of the Invention]

[0014] According to the present disclosure, even when the drawing material has a complex shape, the cylindrical body can be easily arranged along the shape of the outer peripheral surface of the drawing material, and the drawing material can be manufactured efficiently. [Brief explanation of the drawings]

[0015] [Figure 1]FIG. 1 is a perspective view showing a rod-shaped drawing material according to this embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the drawing rod shown in FIG. [Figure 3] FIG. 3 is a perspective view showing a jig assembly used in the method for producing a rod-shaped drawing material according to this embodiment. [Figure 4] 4 is an exploded perspective view showing the drawing material forming jig of the jig assembly shown in FIG. 3. FIG. [Figure 5] Fig. 5(a) is a perspective view showing a first follower jig of the jig assembly shown in Fig. 3. Fig. 5(b) is a perspective view showing a second follower jig of the jig assembly shown in Fig. 3. [Figure 6] Fig. 6(a) is a cross-sectional view of the first tracking jig shown in Fig. 5(a) cut along a plane extending in the first and second directions, and Fig. 6(b) is a cross-sectional view of the first tracking jig shown in Fig. 5(a) cut along a plane different from that of Fig. 6(a) that extends in the first and second directions. [Figure 7] Fig. 7(a) is a cross-sectional view of the second tracking jig shown in Fig. 5(b) cut along a plane extending in the first direction and the second direction, and Fig. 7(b) is a cross-sectional view of the second tracking jig shown in Fig. 5(b) cut along a plane different from that of Fig. 7(a) that extends in the first direction and the second direction. [Figure 8] FIG. 8 is a perspective view of the fixture of the fixture assembly shown in FIG. [Figure 9] 9 is a perspective view of the tip forming jig of the jig assembly shown in FIG. 3. FIG. [Figure 10] FIG. 10 is a perspective view showing a pin unit used in the method for producing a rod-shaped drawing material according to this embodiment. [Figure 11] FIG. 11 is a flowchart showing a method for manufacturing a rod-shaped drawing material according to this embodiment. [Figure 12] FIG. 12 is a perspective view showing one step in the method for producing a rod-shaped drawing material according to this embodiment. [Figure 13]Figure 13(a) is a diagram showing a step subsequent to the step shown in Figure 12. Figure 13(b) is a diagram showing a step subsequent to the step shown in Figure 13(a). [Figure 14] Figure 14(a) is a diagram showing a step subsequent to the step shown in Figure 13(b), and Figure 14(b) is a diagram showing a step subsequent to the step shown in Figure 14(a). [Figure 15] Figure 15(a) is a diagram showing a step subsequent to the step shown in Figure 14(b), and Figure 15(b) is a diagram showing a step subsequent to the step shown in Figure 15(a). [Figure 16] FIG. 16 is a diagram showing a step subsequent to the step shown in FIG. 15(b). [Figure 17] FIG. 17 is a perspective view showing a jig assembly according to a modified example. [Figure 18] FIG. 18 is an exploded perspective view showing a shape following jig according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of a manufacturing method of a rod-shaped drawing material and a rod-shaped drawing material according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are given the same reference numerals, and duplicate explanations will be omitted as appropriate. Furthermore, the drawings may be partially simplified or exaggerated to facilitate understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0017] In the present disclosure, "drawing material" refers to something that draws lines or colors on a drawing target, which is a drawing object. The "drawing material" may be, for example, a coating material used in cosmetics, or a core material used in writing implements such as crayons. The "cosmetic" may be, for example, lipstick, concealer, or blush. The "coating material" may be a rod-shaped material containing a flexible material (for example, a solid, semi-solid, soft, or soft material, or a paste containing these). In this embodiment, an example will be described in which the drawing material is a coating material used in cosmetics.

[0018] First, a rod-shaped drawing material 1 according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a perspective view showing the rod-shaped drawing material 1 according to this embodiment. The rod-shaped drawing material 1 is used, for example, by being held between the user's fingers. As shown in Figure 1, the rod-shaped drawing material 1 has a rod shape extending in one direction A. The rod-shaped drawing material 1 includes a drawing material 2 extending in one direction A and a cylindrical body 3 covering the outer surface of the drawing material 2.

[0019] FIG. 2 is a cross-sectional view showing the rod-shaped drawing material 1 shown in FIG. 1. FIG. 2 shows a cross-section of the rod-shaped drawing material 1 cut along a plane perpendicular to the direction A. In the following description, the cross-sectional shape of the rod-shaped drawing material 1 (or the drawing material 2 or the cylindrical body 3) cut along a plane perpendicular to the direction A may be simply referred to as the cross-sectional shape of the rod-shaped drawing material 1 (or the drawing material 2 or the cylindrical body 3). As shown in FIGS. 1 and 2, the cross-sectional shape of the drawing material 2 is heart-shaped. The cross-sectional shape of the drawing material 2 includes a recess 2a that is recessed toward the inside of the drawing material 2. The drawing material 2 has a tip 21 that is exposed from the cylindrical body 3 at the end in the direction A.

[0020] The cylindrical body 3 is the portion of the rod-shaped drawing material 1 that is held by the user. The cylindrical body 3 is made of a flexible material. "Flexibility" refers to the property of being able to bend under external force. The cylindrical body 3 is sheet-like. For example, the cylindrical body 3 is made of paper. However, the cylindrical body 3 may also be made of a resin film, and the material of the cylindrical body 3 is not particularly limited. The cylindrical body 3 is arranged along the outer peripheral surface of the drawing material 2. The cross-sectional shape of the cylindrical body 3 is similar to the cross-sectional shape of the drawing material 2. The cylindrical body 3 has multiple perforations 3a formed at positions spaced apart from each other in one direction A. The multiple perforations 3a are formed, for example, parallel to each other. The cylindrical body 3 has multiple strips 4 that are the portions between pairs of perforations 3a spaced apart from each other in one direction A.

[0021] A user of the stick-shaped drawing material 1 pinches the outer periphery of the cylindrical body 3 with their fingers and places the tip 21 of the drawing material 2 exposed from the cylindrical body 3 against the area to be drawn on (for example, the user's face) to apply the material (for example, makeup). When the tip 21 of the drawing material 2 becomes shorter as application continues, the user tears the cylindrical body 3 along the perforations 3a to remove the strip 4. The user can lengthen the tip 21 by removing the strip 4 and exposing new drawing material 2 from the cylindrical body 3.

[0022] Next, a jig used in the manufacturing method of the rod-shaped drawing material 1 according to this embodiment will be described with reference to Figures 3 to 10. Figure 3 is a perspective view showing a jig assembly 5 used in the manufacturing method of the rod-shaped drawing material 1 according to this embodiment. The jig assembly 5 is made up of a plurality of jigs. As shown in Figure 3, the jig assembly 5 has a rectangular parallelepiped shape as a whole.

[0023] The jig assembly 5 according to this embodiment is used, for example, when manufacturing a rod-shaped drawing material 1 on a linear production line. For example, a plurality of jig assemblies 5 are placed on a conveying device such as a belt conveyor that can convey an object in one direction, and the conveying device is driven to move the jig assemblies 5 in that direction. As the jig assemblies 5 move, a manufacturing method for the rod-shaped drawing material 1, which will be described later, is carried out, thereby manufacturing the rod-shaped drawing material 1.

[0024] Hereinafter, the longitudinal direction of the jig assembly 5 in a plan view will be referred to as the first direction D1, and the lateral direction of the jig assembly 5 in a plan view will be referred to as the second direction D2. In addition, the direction perpendicular to the first direction D1 and the second direction D2 will be referred to as the third direction D3. The third direction D3 coincides with the height direction of the jig assembly 5. In the following description, the "cross section (cross-sectional shape) when cut along a plane extending in the first direction D1 and the second direction D2" may be simply referred to as the "cross section (cross-sectional shape)."

[0025] The jig assembly 5 has a drawing material forming jig 6, a shape following jig 7, and a tip forming jig 8. The shape following jig 7, the drawing material forming jig 6, and the tip forming jig 8 are arranged in this order in the third direction D3 to form the jig assembly 5.

[0026] Fig. 4 is an exploded perspective view showing the drawing material forming jig 6 shown in Fig. 3. As shown in Fig. 4, the drawing material forming jig 6 is composed of a first forming jig 61 and a second forming jig 62. The first forming jig 61 and the second forming jig 62 each have a rectangular parallelepiped shape. The first forming jig 61 and the second forming jig 62 are arranged in a third direction D3 (the up-down direction in Fig. 4) to form the drawing material forming jig 6.

[0027] The first forming jig 61 has a plurality of first holes 63 arranged in the first direction D1. As an example, the number of the first holes 63 is five. The first holes 63 penetrate the first forming jig 61 from one end 61a to the other end 61b in the third direction D3. In this embodiment, the cross-sectional shape of the first holes 63 is heart-shaped.

[0028] The first forming jig 61 has a fitting portion 64a into which a protrusion 77 (see FIG. 8) of a fixing jig 73 of the shape following jig 7 fits, and a fitting portion 64b into which a protrusion of a fixing jig 74 (described later) fits. One fitting portion 64a is provided at one end side of the first forming jig 61 in the first direction D1. The other fitting portion 64b is provided at the other end side of the first forming jig 61 in the first direction D1. The fitting portions 64a, 64b are recessed from one end 61a of the first forming jig 61 in the third direction D3. In this embodiment, the cross-sectional shapes of the fitting portions 64a, 64b are circular.

[0029] The first forming jig 61 has protrusions 65a and 65b. Each of the protrusions 65a and 65b has a cylindrical shape, for example. The protrusion 65a is provided at one end of the first forming jig 61 in the first direction D1. The protrusion 65b is provided at the other end of the first forming jig 61 in the first direction D1. The protrusions 65a and 65b protrude from the other end 61b of the first forming jig 61 in the third direction D3.

[0030] The second forming jig 62 has a plurality of second holes 66 arranged in the first direction D1. As an example, the number of second holes 66 is five. The positions at which each of the plurality of second holes 66 is provided correspond to the positions at which each of the plurality of first holes 63 is provided. In this embodiment, when the first forming jig 61 is placed on the second forming jig 62, each of the first holes 63 is located directly above each of the second holes 66. The second holes 66 penetrate the second forming jig 62 from one end 62a to the other end 62b in the third direction D3. The cross-sectional shape of the second holes 66 is the same as the cross-sectional shape of the first holes 63. In this embodiment, the cross-sectional shape of the second holes 66 is heart-shaped.

[0031] The second forming jig 62 has a mating portion 67a into which the protrusion 65a of the first forming jig 61 fits, and a mating portion 67b into which the protrusion 65b of the first forming jig 61 fits. The mating portion 67a is provided at one end of the second forming jig 62 in the first direction D1. The mating portion 67b is provided at the other end of the second forming jig 62 in the first direction D1. The mating portions 67a and 67b are recessed from one end 62a of the second forming jig 62 in the third direction D3. The cross-sectional shapes of the mating portions 67a and 67b correspond to the cross-sectional shapes of the protrusions 65a and 65b.

[0032] In this embodiment, when the first forming jig 61 is placed on the second forming jig 62, the fitting portions 67a, 67b are shaped so that the protrusions 65a, 65b can fit into the fitting portions 67a, 67b, respectively. In this embodiment, the cross-sectional shape of the fitting portions 67a, 67b is circular. As an example, an inclined surface (tapered surface) may be formed between the fitting portions 67a, 67b and one end 62a (upper surface) of the second forming jig 62. In this case, the fitting portions 67a, 67b can be fitted into the protrusions 65a, 65b more smoothly.

[0033] The second forming jig 62 has a fitting portion 68a into which the protrusion 82a (see FIG. 9) of the tip portion forming jig 8 fits, and a fitting portion 68b into which the protrusion 82b (see FIG. 9) of the tip portion forming jig 8 fits. The fitting portion 68a is provided at one end side of the second forming jig 62 in the first direction D1. The fitting portion 68b is provided at the other end side of the second forming jig 62 in the first direction D1. The fitting portions 68a, 68b are recessed in the third direction D3 from the other end 62b of the second forming jig 62. In this embodiment, the cross-sectional shape of the fitting portions 68a, 68b is circular.

[0034] The protrusion 65a of the first forming jig 61 fits into the fitting portion 67a of the second forming jig 62, and the protrusion 65b of the first forming jig 61 fits into the fitting portion 67b of the second forming jig 62, thereby forming the drawing material forming jig 6. At this time, the first hole 63 and the second hole 66 communicate with each other, thereby forming an injection molding hole (molding hole) 51 for injection molding the drawing material 2. The injection molding hole 51 penetrates from one end (one end 61a of the first forming jig 61) to the other end (the other end 62b of the second forming jig 62) of the drawing material forming jig 6 in the third direction D3.

[0035] As shown in FIG. 3, the shape tracking jig 7 is disposed at one end (e.g., the upper surface) of the drawing material forming jig 6 in the third direction D3. The shape tracking jig 7 is composed of a first tracking jig 71, a second tracking jig 72, and fixing jigs 73 and 74. The first tracking jig 71 is disposed on one side (upper right side in FIG. 3) of one end of the drawing material forming jig 6 in the second direction D2. The second tracking jig 72 is disposed on the other side (lower left side in FIG. 3) of one end of the drawing material forming jig 6 in the second direction D2. The fixing jig 73 is disposed on one side (lower right side in FIG. 3) of one end of the drawing material forming jig 6 in the first direction D1. The fixing jig 74 is disposed on the other side (upper left side in FIG. 3) of one end of the drawing material forming jig 6 in the first direction D1.

[0036] FIG. 5(a) is a perspective view showing the first tracking jig 71 shown in FIG. 3. The first tracking jig 71 has a plurality of first tracking grooves 70a arranged in the first direction D1. As an example, the number of first tracking grooves 70a is five. The first tracking grooves 70a extend from one end 71a to the other end 71b of the first tracking jig 71 in the third direction D3. First abutment surfaces 79 that abut against the second tracking jig 72 are formed between two adjacent first tracking grooves 70a in the first direction D1 and on both ends of the plurality of first tracking grooves 70a in the first direction D1. Each of the plurality of first abutment surfaces 79 has a planar shape parallel to the first direction D1 and the third direction D3.

[0037] The first tracking jig 71 has a sliding protrusion 75 provided at one end 71c in the first direction D1 and a sliding protrusion 76 provided at the other end 71d in the first direction D1. The sliding protrusion 75 protrudes in the first direction D1 from one end 71c of the first tracking jig 71. The sliding protrusion 76 protrudes in the first direction D1 from the other end 71d of the first tracking jig 71. The sliding protrusions 75, 76 extend in the second direction D2. In this embodiment, the cross-sectional shape of the sliding protrusions 75, 76 when cut along a plane perpendicular to the second direction D2 is semicircular.

[0038] Fig. 6(a) is a cross-sectional view of the first tracking jig 71 cut along a plane extending in the first direction D1 and the second direction D2. As an example, this plane is located closer to the one end 71a of the first tracking jig 71 (upper side in Fig. 5(a)) than the sliding convex portions 75, 76 of the first tracking jig 71. Fig. 6(b) is a cross-sectional view of the first tracking jig 71 shown in Fig. 5(a) cut along a plane different from that shown in Fig. 6(a) that extends in the first direction D1 and the second direction D2. As an example, this plane is located closer to the other end 71b of the first tracking jig 71 (lower side in Fig. 5(a)) than the sliding convex portions 75, 76 of the first tracking jig 71.

[0039] As shown in Fig. 6(a), the cross-sectional shape of the first following groove 70a is semicircular on the one end 71a side in the third direction D3 of the sliding convex portions 75, 76 of the first following jig 71. Also, as shown in Fig. 6(b), the cross-sectional shape of the first following groove 70a is a partial heart shape (the lower half of the heart shape shown in Fig. 2) on the other end 71b side in the third direction D3 of the sliding convex portions 75, 76 of the first following jig 71. The cross-sectional shape of the first following groove 70a gradually changes from a semicircular shape to a partial heart shape as it moves from one end 71a to the other end 71b of the first following jig 71.

[0040] FIG. 5(b) is a perspective view showing the second tracking jig 72 shown in FIG. 3. The second tracking jig 72 has a plurality of second tracking grooves 70b arranged in the first direction D1. As an example, the number of second tracking grooves 70b is five. The second tracking grooves 70b extend from one end 72a to the other end 72b of the second tracking jig 72 in the third direction D3. A plurality of second abutment surfaces 89 that abut against the first tracking jig 71 are formed between two adjacent second tracking grooves 70b in the first direction D1 and on both ends of the plurality of second tracking grooves 70b in the first direction D1. Each of the plurality of second abutment surfaces 89 has a planar shape parallel to the first direction D1 and the third direction D3.

[0041] The second following jig 72 has a sliding protrusion 85 provided at one end 72c in the first direction D1 and a sliding protrusion 86 provided at the other end 72d in the first direction D1. The sliding protrusion 85 protrudes in the first direction D1 from one end 72c of the second following jig 72. The sliding protrusion 86 protrudes in the first direction D1 from the other end 72d of the second following jig 72. The sliding protrusions 85, 86 extend in the second direction D2. In this embodiment, the cross-sectional shape of the sliding protrusions 85, 86 when cut along a plane perpendicular to the second direction D2 is semicircular.

[0042] 7(a) is a cross-sectional view of the second tracking jig 72 cut along a plane extending in the first direction D1 and the second direction D2. As an example, this plane is located closer to the one end 72a of the second tracking jig 72 (upper side in FIG. 5(b)) than the sliding convex portions 85, 86. FIG. 7(b) is a cross-sectional view of the second tracking jig 72 cut along a plane different from that shown in FIG. 7(a) that extends in the first direction D1 and the second direction D2. As an example, this plane is located closer to the other end 72b of the second tracking jig 72 (lower side in FIG. 5(b)).

[0043] As shown in Fig. 7(a), the cross-sectional shape of the second following groove 70b is semicircular on the one end 72a side in the third direction D3 of the second following jig 72 relative to the sliding protrusions 85, 86. Also, as shown in Fig. 7(b), the cross-sectional shape of the second following groove 70b is other than a part of the heart shape described above (the upper half of the heart shape shown in Fig. 2) on the other end 72b side in the third direction D3 of the second following jig 72 relative to the sliding protrusions 85, 86. The cross-sectional shape of the second following groove 70b gradually changes from a semicircular shape to the other part of the heart shape as it moves from one end 72a to the other end 72b of the second following jig 72.

[0044] Fig. 8 is a perspective view showing the fixing jig 73 shown in Fig. 3. The fixing jig 73 fixes the first following jig 71 and the second following jig 72 onto the drawing material forming jig 6. As shown in Fig. 8, the fixing jig 73 has a rectangular parallelepiped shape as a whole.

[0045] The fixing jig 73 has a protrusion 77. The protrusion 77 has, for example, a cylindrical shape. The protrusion 77 protrudes in the third direction D3 from the other end of the fixing jig 73 in the third direction D3 (the lower end in FIG. 8). The protrusion 77 has a shape corresponding to the shape of the fitting portion 64a (see FIG. 4) of the first forming jig 61. In other words, the protrusion 77 has a shape that can be fitted into the fitting portion 64a. In this embodiment, the cross-sectional shape of the protrusion 77 is circular.

[0046] The fixing jig 73 has a sliding recess 78 provided at one end in the first direction D1 (the end on the lower left side in FIG. 8). The sliding recess 78 extends in the second direction D2. The sliding recess 78 has a shape corresponding to the shapes of the sliding protrusions 75 and 86. That is, the sliding recess 78 has a shape that allows the sliding protrusions 75 and 86 to fit into it. In this embodiment, the cross-sectional shape of the sliding recess 78 when cut along a plane perpendicular to the second direction D2 is semicircular.

[0047] 3 is identical to the configuration and function of fixing jig 73. Therefore, in the following description of fixing jig 74, descriptions that overlap with the configuration and function of fixing jig 73 will be omitted as appropriate.

[0048] The fixing jig 74 has a protrusion similar to the protrusion 77 described above. The protrusion protrudes in the third direction D3 at the other end of the fixing jig 74 in the third direction D3. The protrusion of the fixing jig 74 has a shape corresponding to the shape of the fitting portion 64b of the first forming jig 61. The fixing jig 74 has a sliding recess 80 (see FIG. 3) provided at one end in the first direction D1. The sliding recess 80 has a shape corresponding to the shapes of the sliding protrusion 76 and the sliding protrusion 85.

[0049] When placing the shape following jig 7 at one end 61a of the first forming jig 61 (one end of the drawing material forming jig 6 (see FIG. 4)), first, the fixing jigs 73 and 74 are placed at one end 61a of the first forming jig 61. More specifically, the protruding portion 77 of the fixing jig 73 is fitted into the fitting portion 64a of the first forming jig 61, and the protruding portion of the fixing jig 74 is fitted into the fitting portion 64b of the first forming jig 61. At this time, the surface of the fixing jig 73 on which the sliding recess 78 is formed and the surface of the fixing jig 74 on which the sliding recess 80 is formed face each other.

[0050] Next, the first following jig 71 is placed on one end 61a (upper surface) of the first forming jig 61. At this time, as shown in Fig. 5(a) and Fig. 8, the sliding convex portion 75 of the first following jig 71 is fitted into the sliding concave portion 78 of the fixing jig 73. Also, the sliding convex portion 76 of the first following jig 71 is fitted into the sliding concave portion 80 of the fixing jig 74. Then, the first following jig 71 is slid relative to the fixing jigs 73 and 74 in the second direction D2.

[0051] Next, the second tracking jig 72 is placed at one end 61a of the first forming jig 61. At this time, the sliding convex portion 86 of the second tracking jig 72 is fitted into the sliding concave portion 78 of the fixing jig 73. Also, the sliding convex portion 85 of the second tracking jig 72 is fitted into the sliding concave portion 80 of the fixing jig 74. Then, the second tracking jig 72 is slid relative to the fixing jigs 73 and 74 in the second direction D2. As a result, the second abutment surface 89 of the second tracking jig 72 comes into contact with the first abutment surface 79 of the first tracking jig 71.

[0052] At this time, the first following groove portion 70a and the second following groove portion 70b define a shape following hole 70 into which an insert 93 (see FIG. 13(b)) is inserted. The cross-sectional shape of the shape following hole 70 gradually changes from a circular shape to a heart shape from one end (one end 71a and one end 72a) to the other end (the other end 71b and the other end 72b) in the third direction D3 of the shape following jig 7.

[0053] The cross-sectional shape of the shape following hole 70 at the other end (lower end) of the shape following jig 7 is the same as, for example, the cross-sectional shape of the injection molding hole 51 at one end of the drawing material forming jig 6. As a result, when the shape following jig 7 is placed at one end of the drawing material forming jig 6, the shape following hole 70 and the injection molding hole 51 communicate with each other.

[0054] Fig. 9 is a perspective view showing the tip portion forming jig 8 shown in Fig. 3. As shown in Fig. 9, the tip portion forming jig 8 has a rectangular plate shape. The tip portion forming jig 8 forms the tip portion 21 of the rod-shaped drawing material 1 described above.

[0055] The tip forming jig 8 has a plurality of tip forming holes 81 arranged in the first direction D1. As an example, the number of tip forming holes 81 is five. The tip forming holes 81 are provided at one end (the upper end in FIG. 8) of the tip forming jig 8 in the third direction D3. The tip forming holes 81 are recessed from the one end in the third direction D3. In this embodiment, the cross-sectional shape of the tip forming hole 81 at the one end is heart-shaped.

[0056] The tip portion forming jig 8 has a protrusion 82a that fits into the fitting portion 68a (see FIG. 4) of the second forming jig 62, and a protrusion 82b that fits into the fitting portion 68b of the second forming jig 62. The protrusion 82a is provided on one end side of the tip portion forming jig 8 in the first direction D1. The protrusion 82b is provided on the other end side of the tip portion forming jig 8 in the first direction D1. The protrusions 82a and 82b protrude from one end of the tip portion forming jig 8 in the third direction D3. In this embodiment, the cross-sectional shape of the protrusions 82a and 82b is circular.

[0057] The tip portion forming jig 8 is disposed at the other end (the other end 62b, lower end, of the second forming jig 62) of the drawing material forming jig 6. More specifically, the protruding portion 82a of the tip portion forming jig 8 fits into the fitting portion 68a of the second forming jig 62, and the protruding portion 82b of the tip portion forming jig 8 fits into the fitting portion 68b of the second forming jig 62, thereby disposing the tip portion forming jig 8 at the other end of the drawing material forming jig 6.

[0058] The cross-sectional shape of the tip portion forming hole 81 at one end of the tip portion forming jig 8 in the third direction D3 is the same as, for example, the cross-sectional shape of the injection molding hole 51. When the tip portion forming hole 81 is arranged at the other end of the drawing material forming jig 6, the tip portion forming hole 81 and the injection molding hole 51 communicate with each other.

[0059] 10 is a perspective view showing a pin unit 9 used in the manufacturing method of the rod-shaped drawing material 1 according to this embodiment. As shown in FIG. 10, the pin unit 9 is composed of a base portion 91 and a plurality of pins 92.

[0060] The base portion 91 is a portion that forms the base of the pin unit 9. The base portion 91 has a rectangular parallelepiped shape with long sides extending in the first direction D1. The multiple pins 92 are arranged in the first direction D1. As an example, the number of pins 92 is five. Each of the multiple pins 92 corresponds to one of the multiple shape-conforming holes 70 and one of the multiple injection molding holes 51 described above. That is, each pin 92 is insertable into each shape-conforming hole 70 and each injection molding hole 51 along the third direction. The pin 92 extends from the base portion 91 in the third direction D3. In this embodiment, the cross-sectional shape of the pin 92 is a second shape (heart shape) described below. The cross-sectional shape of the pin 92 when cut along a plane perpendicular to the third direction D3 is similar to the cross-sectional shape of the injection molding hole 51.

[0061] Next, a method for manufacturing the rod-shaped drawing material 1 according to this embodiment will be described with reference to Fig. 11 to Fig. 16. Fig. 11 is a flowchart showing a method for manufacturing the rod-shaped drawing material 1 according to this embodiment. Fig. 12 is a diagram showing one step in the method for manufacturing the rod-shaped drawing material 1 according to this embodiment.

[0062] As shown in FIGS. 11 and 12, first, a pin unit 9, a cylindrical body 3, an unsolidified drawing material 2A (see FIG. 15(b)), and a jig assembly 5 are prepared (step S1, preparing step). The "unsolidified drawing material" refers to a liquid drawing material that has not solidified and has fluidity. For example, at this point, the cross-sectional shape of the cylindrical body 3 is a first shape. Through subsequent steps, the cross-sectional shape of the cylindrical body 3 changes from the first shape to a second shape. The second shape is more complex than the first shape. For example, the "first shape" is a shape that does not include a recess that is recessed inward, and the "second shape" is a shape that includes a recess that is recessed inward. In this embodiment, the "first shape" is a circle, and the "second shape" is a heart shape. In step S1, the cross-sectional shape of the cylindrical body 3 is a circle. That is, the cylindrical body 3 has a cylindrical shape. In this embodiment, multiple (for example, five) cylindrical bodies 3 are prepared.

[0063] Next, the jig assembly 5 is formed (step S2). In step S2, the shape-following jig 7 is placed at one end of the drawing material forming jig 6, and the tip forming jig 8 is placed at the other end of the drawing material forming jig 6 (placement step). As a result, the shape-following hole 70 of the shape-following jig 7, the injection molding hole 51 of the drawing material forming jig 6, and the tip forming hole 81 of the tip forming jig 8 are communicated with each other.

[0064] Next, the cylindrical bodies 3 are inserted into the pins 92 to prepare an insert body 93 (see FIG. 13(b)) including the cylindrical bodies 3 and the pins 92 (step S3, preparation step). In step S3, each of the five cylindrical bodies 3 is inserted into the pin 92.

[0065] 11 and 13(a), the cross-sectional shape of the cylindrical body 3 is made to follow the cross-sectional shape of the injection molding hole 51 by the shape following jig 7 (step S4, following step). In step S4, the insert 93 is inserted into the shape following hole 70 of the shape following jig 7 along an insertion direction in which the insert 93 is inserted. In this embodiment, the insertion direction coincides with the third direction D3.

[0066] For example, the cross-sectional shape of the shape-conforming hole 70 gradually changes from a first shape (e.g., circular) to a second shape (e.g., heart-shaped) as it moves from one end to the other end in the third direction D3 of the shape-conforming jig 7. This allows the cross-sectional shape of the cylindrical body 3 to be deformed from the first shape to the second shape by inserting the insert 93 into the shape-conforming hole 70. Therefore, the cross-sectional shape of the cylindrical body 3 when cut on a plane perpendicular to the insertion direction can be made to follow the cross-sectional shape (second shape) of the injection molding hole 51.

[0067] Next, the pin unit 9 is pushed in along the insertion direction until the base portion 91 of the pin unit 9 contacts one end (one end 71a and one end 72a) in the third direction D3 of the shape following jig 7. As a result, the insert 93 is placed in the shape following hole 70 and the injection molding hole 51.

[0068] 11 and 13(b), the shape following jig 7 is removed (step S5). In step S5, the sliding convex portions 75 and 76 of the first following jig 71 are slid along the sliding concave portions 78 of the fixing jig 73 and the sliding concave portions 80 of the fixing jig 74. This allows the first following jig 71 to be removed. Also, in step S5, the sliding convex portions 85 and 86 of the second following jig 72 are slid along the sliding concave portions 78 of the fixing jig 73 and the sliding concave portions 80 of the fixing jig 74. This allows the second following jig 72 to be removed.

[0069] 11 and 14(a), the pin 92 is further pushed in along the insertion direction (step S6, a following step). In step S6, the insert 93 is further inserted into the injection molding hole 51. In this step, the pin unit 9 is pushed in along the insertion direction until the base portion 91 of the pin unit 9 contacts one end of the drawing material forming jig 6 in the third direction D3. This places the insert 93 in a state of being disposed within the injection molding hole 51.

[0070] 11 and 14(b), the pin 92 is removed from the injection molding hole 51 with the cylindrical body 3 remaining in the injection molding hole 51 (step S7, removing step). In step S7, the pin unit 9 is pulled out of the injection molding hole 51 along the third direction D3. This leaves only the cylindrical body 3 remaining in the injection molding hole 51.

[0071] At this time, the tip portion forming hole 81 of the tip portion forming jig 8 extends further in the insertion direction (downward) than the cylindrical body 3 placed in the injection molding hole 51. In this embodiment, the cylindrical body 3 is located only within the injection molding hole 51, and is not located within the tip portion forming hole 81. However, a portion of the cylindrical body 3 may be located within the tip portion forming hole 81.

[0072] Next, the fixing jigs 73 and 74 are removed from the drawing material forming jig 6. More specifically, the protruding portion 77 of the fixing jig 73 is removed from the fitting portion 64a of the first forming jig 61, and the protruding portion of the fixing jig 74 is removed from the fitting portion 64b of the first forming jig 61.

[0073] Next, as shown in FIGS. 11, 15(a), and 15(b), the cylindrical body 3 is filled with unsolidified drawing material 2A (step S8, filling step). In step S8, first, a nozzle 94 for filling the unsolidified drawing material 2A is inserted into the injection molding hole 51. Then, the unsolidified drawing material 2A is filled into the cylindrical body 3 placed in the injection molding hole 51 via the nozzle 94. As a result, the inside of the cylindrical body 3 and the tip forming hole 81 are filled with the unsolidified drawing material 2A. In this embodiment, the unsolidified drawing material 2A is filled up to one end of the drawing material forming jig 6 in the third direction D3.

[0074] Next, the unsolidified drawing material 2A filled in the cylindrical body 3 is solidified (step S9, solidifying step). In step S9, for example, the unsolidified drawing material 2A is cooled to obtain a solidified drawing material 2. As a result, a rod-shaped drawing material 1 having the drawing material 2 solidified inside the cylindrical body 3 is formed inside the injection molding hole 51 and the tip forming hole 81.

[0075] Next, as shown in FIGS. 11 and 16, the rod-shaped drawing material 1 is removed (step S10). In step S10, first, the protruding portion 65a of the first forming jig 61 is removed from the fitting portion 67a of the second forming jig 62, and the protruding portion 65b of the first forming jig 61 is removed from the fitting portion 67b of the second forming jig 62. As a result, the first forming jig 61 is removed from the second forming jig 62 along the third direction D3. At this time, a portion of the rod-shaped drawing material 1 is exposed from the second forming jig 62. In this state, the rod-shaped drawing material 1 is removed from the second hole 66 of the second forming jig 62. Through the above steps, the rod-shaped drawing material 1 described above is manufactured.

[0076] The method for manufacturing the rod-shaped drawing material 1 according to this embodiment has been described above. However, the content and order of each step in the method for manufacturing the rod-shaped drawing material 1 are not limited to those in the above embodiment and can be changed as appropriate.

[0077] Next, a manufacturing method of the rod-shaped drawing material 1 according to this embodiment and the effects of the rod-shaped drawing material 1 will be described. In the manufacturing method of the rod-shaped drawing material 1 according to this embodiment, as shown in FIGS. 12 to 14, an insert 93 including a cylindrical body 3 and a pin 92 is inserted into an injection molding cavity 51, thereby causing the cross-sectional shape of the cylindrical body 3 to conform to the cross-sectional shape of the injection molding cavity 51. Then, as shown in FIG. 15, the cylindrical body 3 is filled with unsolidified drawing material 2A, and the unsolidified drawing material 2A filled in the cylindrical body 3 is solidified, thereby manufacturing the rod-shaped drawing material 1. To this end, a drawing material forming jig 6 is prepared that has a desired cross-sectional shape (second shape, heart shape) for the injection molding cavity 51, and the cross-sectional shape of the cylindrical body 3 is conformed to the cross-sectional shape of the injection molding cavity 51. The unsolidified drawing material 2A is filled inside the cylindrical body 3 having the conformed cross-sectional shape, thereby manufacturing the rod-shaped drawing material 1 having the desired cross-sectional shape.

[0078] Therefore, even if the cross-sectional shape of the injection molding hole 51 is a desired complex shape, it is possible to make the cross-sectional shapes of the cylindrical body 3 and the drawing material 2 follow the cross-sectional shape of the injection molding hole 51. As a result, the drawing material 2 having a cross-sectional shape that follows the cross-sectional shape of the cylindrical body 3 is provided inside the cylindrical body 3 placed in the injection molding hole 51. Therefore, even if the drawing material 2 has a complex shape, the cylindrical body 3 can be easily placed along the shape of the outer peripheral surface of the drawing material 2.

[0079] In this manufacturing method, the cylindrical body 3 is placed in the injection molding cavity 51, and the inside of the cylindrical body 3 is filled with unsolidified drawing material 2A, followed by injection molding of the drawing material 2. That is, by filling the inside of the cylindrical body 3 with the unsolidified drawing material 2A, the cylindrical body 3 can be placed outside the drawing material 2 in advance. Therefore, compared to, for example, wrapping paper or the like around the outer surface of the solidified drawing material 2, the unsolidified drawing material 2A is solidified after filling the cylindrical body 3 with the unsolidified drawing material 2A, which eliminates the need to wrap the cylindrical body 3 around the solidified drawing material 2, thereby improving the manufacturing efficiency of the rod-shaped drawing material 1. Therefore, even when the drawing material 2 has a complex shape, the rod-shaped drawing material 1 can be manufactured efficiently.

[0080] Furthermore, in this embodiment, the drawing material forming jig 6 has a plurality of injection molding holes 51. This allows a plurality of rod-shaped drawing materials 1 to be produced simultaneously by inserting a cylindrical body 3 into each injection molding hole 51 and filling each cylindrical body 3 with unsolidified drawing material 2A. Therefore, the rod-shaped drawing materials 1 can be produced efficiently.

[0081] In this embodiment, the preparing step involves preparing a shape following jig 7 having a shape following hole 70 into which an insert 93 is inserted. As shown in Figures 12, 13(a) and 13(b), this manufacturing method further includes a step of inserting the insert 93 into the shape following hole 70 of the shape following jig 7, before inserting the insert 93 into the injection molding hole 51 in the following step, thereby causing the cross-sectional shape of the cylindrical body 3 to follow the cross-sectional shape of the injection molding hole 51.

[0082] In this case, before inserting the insert 93 into the injection molding hole 51, the cross-sectional shape of the cylindrical body 3 is made to follow the cross-sectional shape of the injection molding hole 51. By making the cross-sectional shape of the cylindrical body 3 follow the cross-sectional shape of the injection molding hole 51 using the shape-following jig 7 before inserting the insert 93 into the injection molding hole 51, the insert 93 can be inserted more smoothly into the injection molding hole 51. Therefore, the rod-shaped drawing material 1 can be manufactured more efficiently.

[0083] In this embodiment, the cross-sectional shape of pin 92 when cut along a plane perpendicular to the insertion direction is similar to the cross-sectional shape (second shape) of injection molding hole 51. In this case, when producing insert 93, the cross-sectional shape of cylindrical body 3 can be changed to be similar to the cross-sectional shape of injection molding hole 51 by making the cross-sectional shape of cylindrical body 3 follow the cross-sectional shape of pin 92, which is similar to the cross-sectional shape of injection molding hole 51.

[0084] Because the cross-sectional shape of the pin 92 located inside the cylindrical body 3 is similar to the cross-sectional shape of the injection molding hole 51 located outside the cylindrical body 3, when the insert 93 is inserted into the injection molding hole 51, the cylindrical body 3 is sandwiched between the inner surface of the injection molding hole 51 and the outer surface of the pin 92, which have similar cross-sectional shapes, so that the cross-sectional shape of the cylindrical body 3 can be more smoothly conformed. Therefore, the cross-sectional shape of the cylindrical body 3 can be made to conform to the cross-sectional shape of the injection molding hole 51 more easily within the injection molding hole 51.

[0085] In this embodiment, the injection molding hole 51 penetrates the drawing material forming jig 6 from one end to the other end in the insertion direction. The method for manufacturing the rod-shaped drawing material 1 further includes, prior to the filling step, a step of placing a tip forming jig 8 at the other end of the drawing material forming jig 6. The tip forming jig 8 has a tip forming hole 81 that extends further in the insertion direction than the cylindrical body 3 placed in the injection molding hole 51.

[0086] In this case, when the unsolidified drawing material 2A is filled into the cylindrical body 3 placed in the injection molding hole 51, the unsolidified drawing material 2A also fills the tip forming hole 81 of the tip forming jig 8 placed at the other end of the drawing material forming jig 6. By solidifying the unsolidified drawing material 2A in this state, it is possible to form the tip 21 of the drawing material 2 that extends further in the insertion direction than the cylindrical body 3. Therefore, the tip 21 of the solidified rod-shaped drawing material 1 protrudes from the cylindrical body 3, and the rod-shaped drawing material 1 can be used immediately without having to roll up the cylindrical body 3.

[0087] 1 and 2, in the rod-shaped drawing material 1 according to this embodiment, the cross-sectional shape of the drawing material 2 when cut in a plane perpendicular to the direction A includes a recess 2a recessed inward of the drawing material 2. Inside a cylindrical body 3 having a cross-sectional shape that is similar to the inward recess 2a when cut in a plane perpendicular to the direction A, the drawing material 2 is provided. Therefore, even if the drawing material 2 has a complex shape, the cylindrical body 3 can be arranged to cover the outer peripheral surface of the drawing material 2, allowing the rod-shaped drawing material 1 to be manufactured efficiently.

[0088] The manufacturing method of a rod-shaped drawing material and embodiments of the rod-shaped drawing material according to the present disclosure have been described above. However, the manufacturing method of a rod-shaped drawing material and the rod-shaped drawing material according to the present disclosure are not limited to the above-described embodiments and can be modified as appropriate.

[0089] For example, in the above-described embodiment, an example was described in which the jig assembly 5 is formed by arranging the shape following jig 7, the drawing material forming jig 6, and the tip forming jig 8 in this order along the third direction D3. However, as shown in FIG. 17 , a jig assembly 5A according to a modified example may have a forming allowance forming jig 10 arranged at one end of the drawing material forming jig 6 in the third direction D3. The "forming allowance" refers to the portion of the drawing material 2 that is formed in excess in advance and then removed for forming.

[0090] The forming margin forming jig 10 has a rectangular shape in a plan view, and matches the shape of the drawing material forming jig 6. The forming margin forming jig 10 has a pair of long wall portions 11, 12 that form a pair of long sides, and a pair of short wall portions 13, 14 that form a pair of short sides.

[0091] The forming margin forming jig 10 has a protruding portion 15 provided on one end side in the first direction D1. The protruding portion 15 protrudes inward in the first direction D1 of the forming margin forming jig 10 from one of the short wall portions 13. The protruding portion 15 is provided at the other end (the lower end in FIG. 17 ) of the short wall portion 13 in the third direction D3.

[0092] The forming allowance forming jig 10 has an inclined portion 16 provided on the other end side in the first direction D1. The inclined portion 16 protrudes inward in the first direction D1 of the forming allowance forming jig 10 from the other short wall portion 14. The inclined portion 16 has an inclined surface 16a that slopes from one end (the upper end in FIG. 17) of the forming allowance forming jig 10 in the third direction D3 toward the other end. In this modified example, the inclined surface 16a has a curved shape that is recessed obliquely downward from the upper end of the short wall portion 14.

[0093] The molding allowance forming jig 10 has one protruding portion (not shown) that fits into the fitting portion 64a (see FIG. 4) of the drawing material forming jig 6, and the other protruding portion (not shown) that fits into the fitting portion 64b. The one protruding portion protrudes in the third direction D3 (downward) from the overhanging portion 15. The other protruding portion protrudes in the third direction D3 from the inclined portion 16.

[0094] One of the protruding portions of the molding allowance forming jig 10 fits into the fitting portion 64a, and the other protruding portion of the molding allowance forming jig 10 fits into the fitting portion 64b, so that the molding allowance forming jig 10 is disposed at one end in the third direction D3 of the drawing material forming jig 6. In a plan view, the area surrounded by the pair of long wall portions 11, 12, the protruding portion 15, and the inclined portion 16 is open. When the molding allowance forming jig 10 is disposed at one end in the third direction D3 of the drawing material forming jig 6, the five injection molding holes 51 are exposed and surrounded by the pair of long wall portions 11, 12, the protruding portion 15, and the inclined portion 16.

[0095] Next, a method for manufacturing the rod-shaped drawing material 1 using the jig assembly 5A according to the modified example will be described. In the following, descriptions that overlap with the method for manufacturing the rod-shaped drawing material 1 according to the above-described embodiment will be omitted as appropriate.

[0096] First, in step S1, a drawing material forming jig 6, a shape following jig 7, a tip forming jig 8, and a molding allowance forming jig 10 are prepared. Then, steps S2 to S7 are carried out in the same manner as in the above-described embodiment. Subsequently, before step S8 of filling with unsolidified drawing material 2A, the shape following jig 7 is removed from one end of the drawing material forming jig 6 in the third direction D3, and the molding allowance forming jig 10 is placed at one end of the drawing material forming jig 6 in the third direction D3.

[0097] Next, step S8 is performed. In the above-described embodiment, the unsolidified drawing material 2A was filled up to one end of the drawing material forming jig 6 in the third direction D3. However, in this modified example, the unsolidified drawing material 2A is filled into the injection molding hole 51 to an extent that it overflows from one end of the drawing material forming jig 6 in the third direction D3. In other words, in this modified example, an amount of unsolidified drawing material 2A greater than the capacity of the injection molding hole 51 and the tip forming hole 81 is filled. The unsolidified drawing material 2A that overflows from the injection molding hole 51 is filled into the area surrounded by the pair of long wall portions 11, 12 and the pair of short wall portions 13, 14 of the molding allowance forming jig 10.

[0098] Next, step S9 is performed. In step S9, the unsolidified drawing material 2A filled in the forming allowance forming jig 10 is solidified to form a forming allowance. Next, the forming allowance formed in the forming allowance forming jig 10 is removed. At this time, the drawing material 2 serving as the forming allowance is removed using, for example, a plate-like member such as a spatula. More specifically, a plate-like member is slid along the inclined surface 16a, and then the plate-like member is slid in the first direction D1 along one end of the drawing material forming jig 6 in the third direction D3. This plate-like member scrapes off the forming allowance in the forming allowance forming jig 10, forming a flat rear end surface at the rear end (upper end in FIG. 17 ) of the rod-shaped drawing material 1.

[0099] Next, the molding allowance forming jig 10 is removed from one end of the drawing material forming jig 6 in the third direction D3. Then, step S10 is carried out. Through the above steps, the aforementioned rod-shaped drawing material 1 is manufactured. The scraped-off drawing material 2 may be re-melted, and in this case, it can be reused as unsolidified drawing material 2A to manufacture the rod-shaped drawing material 1 again.

[0100] In the manufacturing method of the rod-shaped drawing material 1 according to this modified example, a molding allowance forming jig 10 is placed at one end of the drawing material forming jig 6. Furthermore, unsolidified drawing material 2A is filled into the injection molding hole 51 and the molding allowance forming jig 10. The unsolidified drawing material 2A is then solidified to form a molding allowance, and the molding allowance is then removed to form the rear end surface of the rod-shaped drawing material 1. In this case, the rear end surface formed by removing the molding allowance becomes a flat surface that is flush with one end of the drawing material forming jig 6 in the third direction D3.

[0101] If the drawing material rod 1 is manufactured by filling the unsolidified drawing material 2A up to one end of the drawing material forming jig 6 in the third direction D3 without disposing the forming allowance jig 10 at one end of the drawing material forming jig 6, a contracted portion may be formed at the rear end of the drawing material 2 when the unsolidified drawing material 2A is solidified. In this case, a recess recessed in one direction A may be formed on the rear end surface of the drawing material rod 1. In contrast, according to the manufacturing method of the drawing material rod 1 of this modified example, the rear end surface of the drawing material rod 1 can be made flat by removing the forming allowance.

[0102] In the above-described modified example, the molding allowance forming jig 10 has the protruding portion 15 and the inclined portion 16. However, the molding allowance forming jig 10 does not have to have the protruding portion 15 and the inclined portion 16. The shape, size, etc. of the molding allowance forming jig 10 can be changed as appropriate.

[0103] In the above-described modified example, the molding margin forming jig 10 is formed separately from the first forming jig 61. However, the molding margin forming jig 10 and the first forming jig 61 may be formed integrally.

[0104] In the above-described embodiment, an example was described in which the shape tracking jig 7 includes the first tracking jig 71, the second tracking jig 72, and the fixing jigs 73 and 74, and the first forming jig 61 includes the fitting portions 64a and 64b. However, as shown in Fig. 18, a shape tracking jig 7A according to a modified example may include the first tracking jig 71A and the second tracking jig 72A without the fixing jigs 73 and 74. Furthermore, the first forming jig 61 may include protrusions 64c and 64d instead of the fitting portions 64a and 64b.

[0105] The first tracking jig 71A has fitting grooves 77a and 77b on both ends in the first direction D1. The fitting groove 77a is provided at one end (lower right side in FIG. 18) of the first tracking jig 71A in the first direction D1. The fitting groove 77b is provided at the other end (upper left side in FIG. 18) of the first tracking jig 71A in the first direction D1. The fitting grooves 77a and 77b extend in the third direction D3. The fitting grooves 77a and 77b are recessed from the other end 71b of the first tracking jig 71A in the third direction D3. In this modification, the cross-sectional shape of the fitting grooves 77a and 77b is semicircular.

[0106] The first tracking jig 71A has mating portions 78a and 78b on both ends in the first direction D1. The mating portion 78a is provided at one end of the first tracking jig 71A in the first direction D1. The mating portion 78a is provided closer to one end in the third direction D3 than the mating groove 77a (upper side in FIG. 18). The mating portion 78b is provided at the other end of the first tracking jig 71A in the first direction D1. The mating portion 78b is provided closer to one end in the third direction D3 than the mating groove 77b. The mating portions 78a and 78b are recessed in the second direction D2 from the first contact surface 79. In this modification, the cross-sectional shape of the mating portions 78a and 78b when cut along a plane perpendicular to the second direction D2 is circular.

[0107] The second tracking jig 72A has a pair of fitting grooves similar to the fitting grooves 77a and 77b described above. Each of the pair of fitting grooves of the second tracking jig 72A faces the fitting grooves 77a and 77b, respectively, along the second direction D2. The second tracking jig 72A also has a protrusion 88a that fits into the fitting portion 78a and a protrusion 88b that fits into the fitting portion 78b. The protrusion 88a is provided on one end side of the second tracking jig 72A in the first direction D1 (the lower right side in FIG. 18). The protrusion 88a is provided on one end side of the second tracking jig 72A in the third direction D3 (the upper side in FIG. 18) of the fitting groove (one of the fitting grooves) of the second tracking jig 72A that faces the fitting groove 77a. The protrusion 88b is provided on the other end side in the first direction D1 of the second following jig 72A (upper left side in FIG. 18). The protrusion 88b is provided on one end side in the third direction D3 of the fitting groove (the other fitting groove) of the second following jig 72A that faces the fitting groove 77b.

[0108] The protrusions 88a, 88b protrude in the second direction D2 from the second contact surface 89. The cross-sectional shape of each of the protrusions 88a, 88b when cut along a plane perpendicular to the second direction D2 corresponds to the cross-sectional shape of each of the aforementioned fitting portions 78a, 78b. That is, the protrusions 88a, 88b have a shape that allows them to fit into the fitting portions 78a, 78b. In this modification, the cross-sectional shape of the protrusions 88a, 88b is circular.

[0109] The first forming jig 61 has a protrusion 64c that fits into a fitting portion 77c, which will be described in detail later, and a protrusion 64d that fits into a fitting portion 77d. The protrusion 64c is provided on one end side of the first forming jig 61 in the first direction D1. The protrusion 64d is provided on the other end side of the first forming jig 61 in the first direction D1. The protrusions 64c and 64d protrude in the third direction D3 from one end 61a of the first forming jig 61 in the third direction D3. In this modification, the cross-sectional shape of the protrusions 64c and 64d is circular.

[0110] When the shape following jig 7A is placed at one end 61a of the first forming jig 61, first, the protruding portion 88a of the second following jig 72A fits into the fitting portion 78a of the first following jig 71A, and the protruding portion 88b of the second following jig 72A fits into the fitting portion 78b of the first following jig 71A. As a result, the first abutment surface 79 of the first following jig 71A and the second abutment surface 89 of the second following jig 72A come into contact with each other.

[0111] At this time, fitting groove 77a of first following jig 71A and one of the fitting grooves of second following jig 72A define fitting portion 77c into which protrusion 64c fits. Also, fitting groove 77b of first following jig 71A and the other fitting groove of second following jig 72A define fitting portion 77d into which protrusion 64d fits. In this modification, the cross-sectional shapes of fitting portions 77c and 77d are circular.

[0112] Next, the protrusion 64c of the first forming jig 61 fits into the fitting portion 77c of the shape following jig 7A, and the protrusion 64d of the first forming jig 61 fits into the fitting portion 77d of the shape following jig 7A. As a result, the shape following jig 7A is disposed at one end 61a of the first forming jig 61. In the above modification, the shape following jig 7A can also be disposed at one end 61a of the first forming jig 61 in the third direction D3.

[0113] In the above embodiment, an example was described in which, in step S10, the first forming jig 61 is removed from the second forming jig 62 along the third direction D3, and then the drawing material rod 1 is extracted through the second hole 66 of the second forming jig 62. However, in step S10, the drawing material rod 1 may be removed using air. In this case, after step S9 is performed, the tip forming jig 8 is removed from the other end of the drawing material forming jig 6 in the third direction D3. Alternatively, air may be injected into the first hole 63 from one end 61a of the first forming jig 61 to push the drawing material rod 1 toward the other end 62b of the second forming jig 62. The air may be generated by a negative pressure source such as a vacuum.

[0114] In the above embodiment, an example has been described in which the cross-sectional shape of the cylindrical body 3 is made to conform to the cross-sectional shape of the injection molding hole 51 by inserting the insert 93 into the shape-conforming hole 70 along the insertion direction in step S4. However, the cross-sectional shape of the cylindrical body 3 may be made to conform to the cross-sectional shape of the injection molding hole 51 using a negative pressure source. In this case, the pin unit 9 may have air holes formed inside the base portion 91 and inside the pins 92. As an example, the air holes extend in the third direction D3 from one end of the base portion 91 in the third direction D3 and open to a side surface of the pin 92 (for example, a surface facing the first direction D1 or the second direction D2).

[0115] In the manufacturing method of the rod-shaped drawing material 1 according to this example, after step S4, air is sucked in through an air hole provided in the base portion 91 using a negative pressure source. As a result, the air between the inner surface of the cylindrical body 3 and the outer surface of the pin 92 (the side surface of the pin 92 described above) is reduced in pressure, and the inner surface of the cylindrical body 3 can be tightly attached to the outer surface of the pin 92, allowing the cross-sectional shape of the cylindrical body 3 to more smoothly follow the cross-sectional shape of the pin 92. Because the cross-sectional shape of the pin 92 is similar to the cross-sectional shape of the injection molding hole 51, the cross-sectional shape of the cylindrical body 3 can more smoothly follow the cross-sectional shape of the injection molding hole 51.

[0116] In the above embodiment, an example has been described in which the cross-sectional shape of the cylindrical body 3 is made to conform to the cross-sectional shape of the injection molding hole 51 by inserting the insert 93 into the injection molding hole 51 in step S6. At this time, a negative pressure source may be used to make the cross-sectional shape of the cylindrical body 3 conform to the cross-sectional shape of the injection molding hole 51. In this case, at least one of the first forming jig 61 and the second forming jig 62 may have an air hole. This air hole extends, for example, from the end face of the drawing material forming jig 6 facing the second direction D2 to the injection molding hole 51. This air hole connects the injection molding hole 51 and the outside of the drawing material forming jig 6 to each other.

[0117] In the manufacturing method of the rod-shaped drawing material 1 according to this example, after step S7, air is sucked through an air hole from the end face of the drawing material forming jig 6 facing the second direction D2. As a result, the air between the inner surface of the injection molding hole 51 and the outer surface of the cylindrical body 3 is decompressed, and the outer surface of the cylindrical body 3 can be tightly attached to the inner surface of the injection molding hole 51, so that the cross-sectional shape of the cylindrical body 3 can be made to conform to the cross-sectional shape of the injection molding hole 51. Note that the suction of air by the negative pressure source may be performed after step S8.

[0118] In the above-described embodiment, an example has been described in which a plurality of (e.g., five) rod-shaped drawing materials 1 are manufactured using one jig assembly 5. However, the jig assembly 5 may have one shape-following hole 70, one injection molding hole 51, and one tip-forming hole 81. In this case, the jig assembly 5 can be made smaller. In this example, a plurality of jig assemblies 5 are placed on a turntable that can rotate in one direction, and the turntable is rotated to rotate the plurality of jig assemblies 5 in one direction. The above-described manufacturing method for the rod-shaped drawing materials 1 is carried out in accordance with the rotation of the jig assembly 5, thereby manufacturing the rod-shaped drawing materials 1.

[0119] In the above-described embodiment, an example was described in which the cross-sectional shape (first shape) of the cylindrical body 3 before deformation was circular. However, the cross-sectional shape of the cylindrical body 3 before deformation may be elliptical, oval, or polygonal, such as triangular, rectangular, or hexagonal, and may be changed as appropriate. In the above-described embodiment, an example was described in which the cross-sectional shape (second shape) of the injection molding hole 51 was heart-shaped. However, the cross-sectional shape of the injection molding hole 51 may be, for example, star-shaped or wavy, and may be changed as appropriate. The cross-sectional shape of the injection molding hole 51 may be changed as appropriate depending on the shape of the rod-shaped drawing material 1 to be manufactured.

[0120] In the above embodiment, an example has been described in which the drawing material 2 is formed by injection molding. However, the method for forming the drawing material 2 may be a method other than injection molding. For example, the drawing material 2 may be formed by pressure molding. Furthermore, the drawing material 2 may be formed by simply filling the injection molding hole 51 with unsolidified drawing material 2A. [Explanation of symbols]

[0121] 1...rod-shaped drawing material, 2...drawing material, 2A...unsolidified drawing material, 2a...recess, 3...cylindrical body, 4...strip, 5, 5A...jig assembly, 6...drawing material forming jig, 7, 7A...shape following jig, 8...tip forming jig, 9...pin unit, 10...molding margin forming jig, 11, 12...long wall portion, 13, 14...short wall portion, 15...extending portion, 16...inclined portion, 16a...inclined surface, 21...tip portion, 51...injection molding hole (molding hole), 61...first forming jig, 61a, 62a, 71a, 71c, 72a, 72c...one end, 61b, 62b, 71b, 71d, 72b, 72d...other end, 62...second forming jig, 63...first hole, 64a, 64b, 67a , 67b, 68a, 68b, 77c, 77d, 78a, 78b... fitting portion, 64c, 64d, 65a, 65b, 77, 82a, 82b, 88a, 88b... protrusion portion, 66... ​​second hole, 70... shape following hole, 70a... first following groove portion, 70b... second following groove portion, 71, 71A... first following jig, 72, 72A... 2. Following jig, 73, 74...fixing jig, 75, 76, 85, 86...sliding convex portion, 77a, 77b...engagement groove, 78, 80...sliding concave portion, 79...first abutment surface, 89...second abutment surface, 91...base portion, 92...pin, 93...insertion body, 94...nozzle, A...one direction, D1...first direction, D2...second direction, D3...third direction.

Claims

1. a step of preparing a pin, a flexible cylindrical body, an unsolidified drawing material, and a drawing material forming jig having a forming hole for forming the drawing material; inserting the pin into the cylindrical body to prepare an insert including the cylindrical body and the pin; a step of inserting the insert into the molding hole so that the cross-sectional shape of the cylindrical body when cut along a plane perpendicular to an insertion direction, which is a direction in which the insert is inserted, conforms to the cross-sectional shape of the molding hole; removing the pin from the molding hole while the cylindrical body is placed in the molding hole; a step of filling the cylindrical body with the unsolidified drawing material; and solidifying the drawing material filled in the cylindrical body. A manufacturing method of a rod-shaped drawing material.

2. In the preparing step, a shape-following jig having a shape-following hole into which the insert is inserted is prepared; The method further includes a step of inserting the insert into the shape-following hole of the shape-following jig before inserting the insert into the forming hole in the following step, thereby causing the cross-sectional shape of the cylindrical body to follow the cross-sectional shape of the forming hole. A method for producing the rod-shaped drawing material according to claim 1.

3. a cross-sectional shape of the pin when cut along a plane perpendicular to the insertion direction is similar to the cross-sectional shape of the forming hole; A method for producing the rod-shaped drawing material according to claim 1 or 2.

4. the molding hole penetrates the drawing material forming jig from one end to the other end in the insertion direction, The method further includes a step of placing a tip portion forming jig on the other end of the drawing material forming jig before the filling step, the tip portion forming jig has a tip portion forming hole extending further in the insertion direction than the cylindrical body disposed in the forming hole; A method for producing the rod-shaped drawing material according to claim 1 or 2.

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