JP5811778B2 - Method of manufacturing stringed bows, stringed bows and stringed bows - Google Patents

Description

  The present invention relates to a method for manufacturing a string instrument bow, a string instrument bow, and a string instrument bow. In particular, the head part has a beautiful appearance with no voids, and attachment or striking of a member for holding a string causes damage. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a stringed instrument bow kite that can provide a stringed instrument bow kite that is difficult and has excellent strength, a stringed instrument bow kite, and a stringed instrument bow equipped with the same.

Traditionally, strings made of natural wood have been used for string instrument bows such as violins and cellos. For natural wood, Fernanbuco wood, which is dense and hard, resistant to moisture and excellent in bending strength, has been mainly used.
However, in recent years, Fernanbuco trees have fallen dramatically, making it difficult to obtain. For this reason, a stringed instrument bow is manufactured using a composite material (FRP (fiber reinforced plastic)) of a fiber and a resin such as carbon fiber or glass fiber instead of natural wood such as Fernanbuco. Yes.

  For example, Patent Document 1 describes a spear formed from a glass fiber sheet impregnated with plastic, or a bow head of a spear formed by plastic molding by injection molding or other appropriate methods.

  In addition, as a method of manufacturing the head part of a stringed instrument bow made of a conventional fiber reinforced plastic, for example, in a cavity of a mold made up of an upper mold and a lower mold, there is an excessive volume than the volume in the cavity. There is a method in which the fiber reinforced plastic is placed and molded by applying vertical pressure from the upper mold and the lower mold while heating.

Japanese Patent Publication No. 44-19189

However, the stringed instrument bow made of fiber reinforced plastic obtained by using the conventional technique has the following problems.
Usually, the head portion of the string instrument bow has a recess for attaching a member for holding the end of the horse hair to the head portion. The head portion of the heel made of fiber reinforced plastic has a disadvantage that the inside of the concave portion of the head portion is easily damaged when a member for holding horse hair is attached to the head portion.

In addition, in a conventional bag made of fiber reinforced plastic, the head portion is easily damaged by hitting or the like, and it has been desired to improve the strength of the head portion.
In addition, a conventional bag made of fiber reinforced plastic has a large number of voids formed on the surface of the head portion, and it has been required to reduce the number of voids and improve the appearance.

  The present invention has been made in view of the above circumstances, and is a stringed instrument bow having a beautiful appearance with no voids in the head portion and excellent strength that is difficult to cause damage due to attachment or striking of a member that holds horse hair. It is an object of the present invention to provide a stringed instrument bow kite that can produce a kite, a stringed instrument bow kite, and a stringed instrument bow including the same.

In order to achieve the above object, the present invention employs the following configuration.
The method of manufacturing a stringed instrument bow wing according to the present invention includes an arcuate rod-shaped main body portion and a head portion formed by extending from one end portion of the main body portion in a direction intersecting the extending direction of the main body portion. A method for manufacturing a stringed bow bow, a main body winding step of winding a fiber resin prepreg around a main body core to form a molded product of the main body, and winding a fiber resin prepreg around the head core. And forming a head part molded product, wherein the core metal for the head part is formed upright through an end face molding surface of an end face mold for molding the end face of the head part. A step of forming an inner layer by winding a long fiber resin prepreg in contact with the core metal for the head portion, and a short fiber resin prepreg having a fiber length shorter than that of the long fiber resin prepreg on the outer side of the inner layer Forming the layer and the intermediate A head portion winding step including a step of forming an outer layer by winding a long fiber resin prepreg on the outside of the head portion, and the head portion molding product and the head portion molding product from the body portion to the head portion integrally. In the cavity of the mold to be molded, the end face mold is moved to the end face forming position of the mold along the head core metal while heating, and the volume in the cavity is reduced. And a molding step of molding a molded product by applying pressure.

  In the method for manufacturing a stringed bow of the present invention, the fiber length of the short fiber resin prepreg may be 1 mm to 10 mm.

A stringed instrument bow wing according to the present invention is a stringed instrument bow comprising a bow-shaped main body part and a head part formed extending from one end of the main body part in a direction intersecting the extending direction of the main body part. The head portion has a recess opening in the end surface, and the wall portion forming the head portion is disposed along an inner layer surrounding the recess made of fiber reinforced plastic and an outer surface of the head portion. An outer layer formed between the inner layer and the outer layer, and an intermediate layer made of fiber reinforced plastic having a fiber length shorter than that of the inner layer and the outer layer are formed in the thickness direction. And
The stringed instrument bow of the present invention is provided with the string instrument bow of the present invention.

  The method of manufacturing a stringed instrument bow wing according to the present invention includes a main body winding step of winding a fiber resin prepreg around a main body core to form a main body molded article, and a fiber resin prepreg on the head core. A head part winding step for winding and forming a head part molding product and a molding process for molding the molded product are provided, and the head part winding step forms the end face of the head part as a core part for the head part. A step of forming an inner layer by winding a long fiber resin prepreg in contact with the core metal for the head portion using a material standing up through the end surface molding surface of the end surface mold, and the long outside the inner layer Winding the head part including a step of forming an intermediate layer by arranging a short fiber resin prepreg having a fiber length shorter than that of the fiber resin prepreg and a step of forming an outer layer by winding the long fiber resin prepreg around the outer side of the intermediate layer Attaching process In the molding step, the main body part molded product and the head part molded product are placed in a cavity of a mold for integrally molding the head part from the main body part, and the end face mold is Since the pressure is applied by reducing the volume in the cavity along the head core metal to the end face forming position of the mold, the intermediate layer is moved excessively by the outer layer and the inner layer during molding. It flows following the movement of the end face mold while being suppressed. Therefore, according to the method for manufacturing a stringed instrument bow kite of the present invention, a book having a head portion having a beautiful appearance without voids and an excellent strength that hardly causes damage due to attachment or striking of a member that holds horse hair. The stringed bow of the invention is obtained.

  In addition, the stringed bow of the present invention is obtained by using the method for manufacturing the stringed bow of the present invention, and therefore includes a main body portion and a head portion, and the head portion is a recess that opens to the end face. And the wall part forming the head part is disposed between the inner layer surrounding the recess made of fiber reinforced plastic, the outer layer disposed along the outer surface of the head part, and between the inner layer and the outer layer, The inner layer and the intermediate layer made of fiber reinforced plastic having a fiber length shorter than that of the outer layer are formed in the thickness direction.

  Therefore, the stringed bow of the present invention has an excellent strength in which the inner surface of the recess opening in the end surface of the head portion is an inner layer, and when attaching a member for holding horse hair to the head portion, It becomes difficult to cause breakage in the recess. In addition, the stringed bow of the present invention has an excellent strength in which the outer surface of the head portion is composed of an outer layer, so that the head portion is not easily damaged by striking or the like.

FIG. 1 is a perspective view showing an example of a stringed instrument bow of the present invention. FIG. 2 is an enlarged cross-sectional view showing an enlarged head portion of the scissors provided in the stringed musical instrument bow shown in FIG. FIG. 3 is a schematic view showing an example of a mold used in the manufacturing method of the bag according to the present embodiment, and FIG. 3A is an upper mold and a lower mold as viewed from the inner surface side during molding. FIG. FIG. 3B is a schematic perspective view showing an example of an end face mold. FIG. 4 is a process diagram for explaining an example of the head portion winding process in the manufacturing method of the bag according to the present embodiment. FIG. 4A shows a process of forming the inner layer, and FIG. FIG. 4C shows a step of forming the outer layer. FIG. 5 is an enlarged schematic view for explaining the movement of the end face mold in the molding process, and FIG. 5A is a schematic view showing a state before the end face mold is moved, and FIG. ) Is a schematic view showing a state after the end face mold is moved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing an example of a stringed instrument bow of the present invention. FIG. 2 is an enlarged cross-sectional view showing an enlarged head portion of the scissors provided in the stringed musical instrument bow shown in FIG.
A stringed musical instrument bow 15 shown in FIG. 1 is provided with a saddle 5 and horse hair 5a according to an embodiment of the present invention. The stringed bow 5 shown in FIG. 1 is made of fiber reinforced plastic. The stringed instrument bow 5 includes a bow-shaped main body 51 and a head 52 provided at one end of the main body 51. The main body 51 is a hollow body having a substantially circular cross-sectional view.

  As shown in FIGS. 1 and 2, the head portion 52 extends from one end portion 52 a of the main body portion 51 in a direction intersecting with the extending direction of the main body portion 51, and the end surface from the one end portion 52 a of the main body portion 51. The width of the main body 51 in the extending direction is increased toward 52b. Moreover, the head part 52 has the recessed part 52c opened to the end surface 52b, as shown in FIG. The concave portion 52c is for attaching a member (wedge) for holding the end portion of the horse hair 5a to the head portion 52.

  In the stringed bow 5 shown in FIG. 1, the wall portion 55 made of fiber reinforced plastic formed between the inner surface of the recess 52c and the outer surface of the head portion 52 is an inner layer 54 that is a long fiber layer surrounding the recess 52c. And an outer layer 53 that is a long fiber layer disposed on the outer surface of the head portion 52, and a short fiber having a shorter fiber length than the inner layer 54 and the outer layer 53 and contained in the fiber reinforced plastic. An intermediate layer 56 made of a fiber layer is formed in the thickness direction.

Next, as an example of a method for manufacturing a stringed instrument bow kite according to the present invention, a method for manufacturing the stringed instrument bow kite 5 shown in FIG. 1 will be described as an example.
First, the metal mold | die used in the manufacturing method of the bag of this embodiment is demonstrated. FIG. 3 is a schematic view showing an example of a mold used in the present embodiment, and FIG. 3A is a schematic plan view of an upper mold and a lower mold as viewed from the inner surface side during molding. FIG. 3B is a schematic perspective view showing an example of an end face mold disposed in the head forming portion indicated by reference numeral 14 in FIG.

  The mold 10 shown in FIG. 3 (a) is for integrally forming the head part 52 from the main body part 51 of the flange 5, and the upper mold 11 and the lower mold 12 shown in FIG. It has an end face mold 13 shown in 3 (b). As shown in FIG. 3A, the upper mold 11 has a first recess 11 a corresponding to the outer shape of one side surface of the flange 5, and the lower mold 12 is the other side surface side of the flange 5. It has the 2nd recessed part 12a corresponding to the external shape. At one end of the first recess 11a and the second recess 12a, the upper surface of the upper mold 11 and the upper surface of the lower mold 12 are arranged opposite to each other to form an inner surface shape corresponding to the outer shape of the head portion 52. A head forming portion 14 having a recess is provided. The head forming portion 14 is formed with a guide portion 14a for guiding the moving direction of the end face mold 13 by arranging a slide portion 13d of the end face mold 13 to be described later. Moreover, the code | symbol 14b shown to Fig.3 (a) has shown the end surface formation position which is a boundary line of the surface which shape | molds the outer surface of the head part 52 of the guide part 14a and the head formation part 14. FIG.

  The end surface mold 13 shown in FIG. 3B has an end surface forming surface 13a for forming the end surface 52b of the head portion 52 shown in FIG. In the mold 10 shown in FIG. 3A, the end face mold 13 is disposed on the head forming portion 14 with the end face molding face 13a facing inward, and the upper mold 11 and the lower mold 12 are placed in FIG. A cavity surrounded by the first concave portion 11a, the second concave portion 12a, and the end surface molding surface 13a is formed by overlapping the upper surface of the upper die 11 and the upper surface of the lower die 12 shown in a). It has become so.

  3B has a columnar slide portion 13d having an upper surface shape corresponding to the end surface 52 of the head portion 52 on a base 13c on a quadrangular column. In the end face mold 13 shown in FIG. 3 (b), the upper surface of the slide portion 13d is an end face molding surface 13a, and the length of the side surface of the slide portion 13d is the head forming portion shown in FIG. 3 (a). The length of the 14 guide portions 14a is substantially the same. Further, the cross-sectional shape of the guide portion 14a in the thickness direction of the mold 10 when the upper surface of the upper mold 11 and the upper surface of the lower mold 12 are arranged to face each other is substantially the same as the shape of the end surface 52b of the head portion 52. It is the same.

  The end face mold 13 shown in FIG. 3B is moved to the end face forming position 14b of the mold 10 shown in FIGS. 3A and 5 along the head core 13b during molding. is there. The core metal 13b for the head part has a tip part 13e corresponding to the bottom of the concave part 52c of the head part 52 shown in FIG. 2 after the core metal 13b for head is extracted after molding, and the end surface molding surface of the end face mold 13 The fiber resin prepreg is wound around before being formed. At the time of molding, the slide portion 13d of the end face mold 13 is moved inside the cavity along the guide portion 14a in the head forming portion 14. At that time, the end surface molding surface 13a moves to the end surface forming position 14b along the fixed head core metal 13b, so that the fiber resin prepreg wound around the end portion 13e side of the end surface molding surface 13a enters the cavity. It will be pushed in.

  In the manufacturing method of the scissors of this embodiment using such a metal mold | die 10, first, the fiber resin prepreg which consists of carbon fiber resin with a predetermined | prescribed thickness is wound around the core part (mandrel) for body parts which is not illustrated, and a main-body part Form a molded product (main body winding step). In the present embodiment, when the fiber resin prepreg is wound around the core for the main body, the thickness, the number of layers, the angle, and the like of the fiber resin prepreg to be wound are adjusted as appropriate so that the rigidity of the string 5 is the string 5 of the stringed instrument bow. As an appropriate range.

  Next, a fiber resin prepreg is wound around the core metal core 13b once fixed to the end face mold 13 shown in FIG. 3B, and the head part molded product 17 shown in FIG. Form (head part winding step). The weight of the head part molded product 17 is calculated according to the weight of the head part 52. In the present embodiment, in consideration of the function as the head portion 52 and the weight of the head portion 52, in the head portion winding step, the thickness, the number of layers, the angle, and the like of the fiber resin prepreg to be wound can be appropriately adjusted. preferable.

  FIG. 4 is a process diagram for explaining an example of a head part winding process in the method for manufacturing a bag according to this embodiment. In the head part winding step of the present embodiment, first, as shown in FIG. 4A, the core part 13b for the head part is positioned at the tip part 13e side of the end face molding surface 13a of the end face mold 13. The inner layer is formed by winding the long fiber resin prepreg 2 in contact with the head cored bar 13b.

  In the present embodiment, the portion of the inner layer on the end surface molding surface 13a side prevents variations in the deformation of the head portion molded product 17 when the slide portion 13d is pushed inward, and the head of uniform quality. In order to form the ridge 5 having the portion 52 with good yield, it is preferably formed in contact with the end face molding surface 13a.

As the long fiber resin prepreg 2 of the inner layer, a carbon fiber resin such as a sheet shape, a string shape, or a ribbon shape is used. The thickness of the long fiber resin prepreg 2 is not particularly limited, and a long fiber resin prepreg 2 that can be easily wound around the core metal 13b for the head portion can be used. As the carbon fiber constituting the long-fiber resin prepreg 2, unidirectionally aligned ones or bi-directional woven fabrics can be used.
The fiber length of the inner layer long fiber resin prepreg 2 is preferably equal to or greater than the circumferential length of the core metal core 13b, and is preferably equal to or greater than 10 mm. When the fiber length of the long-fiber resin prepreg 2 is 10 mm or more, the inner surface 54 of the concave portion 52c of the head portion 52 is obtained from the inner layer 54 which is a long-fiber layer having excellent strength, so the horse hair 5a is retained. The damage at the time of attaching the member to be attached to the head portion 52 can be effectively prevented.
The upper limit of the fiber length of the long-fiber resin prepreg 2 of the inner layer is not particularly limited, and can be determined according to the ease of winding around the core metal core 13b.

Next, as shown in FIG.4 (b), the short fiber resin prepreg 3 whose fiber length is shorter than the long fiber resin prepreg 2 is arrange | positioned outside the inner layer, and an intermediate | middle layer is formed.
As the short fiber resin prepreg 3, a material obtained by cutting the long fiber resin prepreg 2 can be used. The fiber length of the short fiber resin prepreg 3 is not more than 2 mm and not more than 10 mm, and is preferably in the range of 1 mm to 10 mm. When the fiber length of the short fiber resin prepreg 3 exceeds the fiber length of the inner layer and outer layer long fiber resin prepregs 2, the end surface mold 13 is moved along the head portion core metal 13 b during molding to the end surface formation position 14 b of the mold 10. Even if the fiber resin prepreg is pushed into the cavity and pressure is applied, the fiber resin prepreg constituting the head part molding 17 follows the movement of the end face mold 13 and does not flow. A gap remains and a void is formed in the head portion 52.

  When the fiber length of the short fiber resin prepreg 3 is 10 mm or less, the short fiber resin prepreg 3 easily flows along with the movement of the end face mold 13 during molding, and the voids in the cavity are efficiently eliminated. The head portion 52 having a beautiful appearance without voids is formed. In order to further improve the fluidity of the short fiber resin prepreg 3 at the time of molding and prevent void formation more effectively, the fiber length of the short fiber resin prepreg 3 should be 8 mm or less. Preferably, it is 6 mm or less.

  Moreover, when the fiber length of the short fiber resin prepreg 3 is 1 mm or more, excessive movement of the short fiber resin prepreg 3 accompanying movement of the end face mold 13 during molding is suppressed by the inner layer and an outer layer described later. As a result, the short fiber resin prepreg 3 flows out to the outside of the inner layer and the outer layer at the time of molding, and between the upper mold 11 and the lower mold 12 or between the end face mold 13 and the upper mold 11 and / or the lower mold. Outflow between the mold 12 and the mold 12 can be prevented, and formation of burrs containing carbon fibers after molding can be prevented.

  When the carbon fiber constituting the short fiber resin prepreg 3 flows out of the mold 10 and many burrs including the carbon fiber are formed, the mold 10 is damaged, and the quality and productivity of the head portion 52 are reduced. It becomes easy and is not preferable. In addition, a post-process for removing burrs containing fibers is necessary, increasing the burden and reducing productivity. In order to effectively prevent the short fiber resin prepreg 3 from flowing out of the mold 10 during molding, the fiber length of the short fiber resin prepreg 3 is more preferably 2 mm or more.

As the short fiber resin prepreg 3, a cut piece obtained by cutting the long fiber resin prepreg 2 may be used as it is. However, a cut piece having a fiber length equal to or shorter than the long fiber resin prepreg 2 is pressed into a plate shape. It may be a thing.
In the present embodiment, it is preferable to adjust the amount of the short fiber resin prepreg 3 that forms the intermediate layer so that the weight of the head part molded product 17 is a predetermined weight. When the short fiber resin prepreg 3 is made by pressing a cut piece having a fiber length equal to or shorter than the long fiber resin prepreg 2 into a plate shape, the intermediate layer depends on the area of the plate-like short fiber resin prepreg 3 to be used. The weight can be easily adjusted with high accuracy. In addition, when the short fiber resin prepreg 3 is a plate obtained by pressing a cut piece having a fiber length equal to or shorter than that of the long fiber resin prepreg 2, the short fiber resin prepreg 3 has a long fiber resin prepreg. Compared to the case of using a cut piece of 2 or less as it is, the short fiber resin prepreg 3 can be easily arranged outside the inner layer, the amount of air contained in the intermediate layer can be easily reduced, and voids can be formed. It can be prevented more effectively.

  As shown in FIG. 4B, the short fiber resin prepreg 3 is preferably arranged so that the outer peripheral dimension with the head cored bar 13b as the axis increases as the position is closer to the end surface molding surface 13a. The outer shape of the head portion 52 is more preferably arranged so as to approximate the outer shape of the head portion 52. The intermediate layer is preferably formed so as to completely cover the inner layer. For example, a part of the inner layer such as the inner layer formed at the tip portion 13e of the core metal 13b for the head portion is covered with the intermediate layer. It does not have to be.

  Next, as shown in FIG.4 (c), the long fiber resin prepreg 2 is wound around the outer side of an intermediate | middle layer, and an outer layer is formed. Thereby, the head part molded product 17 is obtained. As the long fiber resin prepreg 2 used for the outer layer, the same one as the inner layer can be used. The fiber length of the outer layer long fiber resin prepreg 2 is longer than the short fiber resin prepreg 3, and is preferably not less than the circumferential length of the head core metal 13b and preferably not less than 10 mm. When the fiber length of the long fiber resin prepreg 2 is 10 mm or more, since the outer surface of the head portion 52 is composed of the outer layer 55 which is a long fiber layer having excellent strength, the head portion 52 can be obtained by further striking or the like. Is difficult to break. The upper limit of the fiber length of the outer layer long fiber resin prepreg 2 is not particularly limited, and can be determined according to the ease of winding around the intermediate layer.

  Moreover, in this embodiment, since the fiber length of the long fiber resin prepreg 2 used for the inner layer and the outer layer is longer than the short fiber resin prepreg 3, the short fibers accompanying the movement of the end face mold 13 at the time of molding. Excessive movement of the resin prepreg 3 can be suppressed by the inner layer and the outer layer, and burrs containing carbon fibers are prevented from being formed after molding.

  Next, a molding process is performed. In the molding process, first, a body part molding is performed by winding a fiber resin prepreg around a body core (mandrel) between the first recess 11a and the second recess 12a of the mold 10 shown in FIG. And a head part molded article 17 in which a fiber resin prepreg is wound around the head cored bar 13b. At this time, the main body part molded product is installed between the first concave portion 11a and the second concave portion 12a in a state of being integrated with the main body cored bar. Further, the head part molded product 17 is installed on the head forming part 14 of the mold 10 with the end surface molding surface 13a facing inward in an integrated state with the head core metal 13b and the end surface mold 13. As a result, a cavity surrounded by the first recess 11a, the second recess 12a, and the end surface molding surface 13a is formed.

Thereafter, the end face mold 13 is moved to the end face forming position 14b of the mold 10 along the head core metal 13b while being heated, and pressure is applied to the mold 10 to thereby apply the main body 51 and the head section. The stringed bow 5 of the stringed musical instrument bow is molded.
In addition, conditions, such as the heating temperature at the time of shaping | molding and a heating time, can be suitably determined with the material used for the main body part molded product and the head part molded product 17, thickness, the shape of the collar 5, etc., and are not specifically limited. Further, the movement of the end face mold 13 in the molding step may be performed simultaneously with the start of the heating of the mold 10 or may be performed after preheating at a predetermined temperature. Further, the end face mold 13 may be moved at a time for all the moving distances, or may be moved stepwise by dividing the moving distance into a plurality of distances.

  Here, the movement of the end face mold 13 in the molding step of the present embodiment will be described with reference to the drawings. FIG. 5A is a schematic view showing a state before the end face mold 13 is moved, and FIG. 5B is a schematic view showing a state after the end face mold 13 is moved. 5A and 5B, the fiber resin prepreg is not shown in order to make the drawings easy to see. 5 (a) and 5 (b), the upper mold 11 is not shown and the state in the mold 10 is shown for easy viewing of the drawings.

  5 (a) and 5 (b), reference numeral 16 moves the end surface molding surface 13a of the end surface mold 13 to the end surface forming position 14b side while supporting the end surface mold 13 in the head forming portion 14. Shows the jig. The jig 16 is installed so as to sandwich the base body 13c of the end face mold 13 disposed in the head forming portion 14 from both sides in the longitudinal direction of the flange 5, and the end face mold 13 is formed as an end face of the mold 10. A moving means (not shown) for moving to the position 14b side is provided.

  As shown in FIG. 5A, in the state before the end face mold 13 is moved, the end face molding surface 13a which is the upper end of the slide portion 13d of the end face mold 13 disposed in the head forming portion 14 is the head forming. It is arranged so as to be positioned with a gap from the position of the outer edge portion 14c of the guide portion 14a of the portion 14 to the end surface forming position 14b side which is a boundary line with the surface forming the outer surface of the head portion 52. That is, in the state before the end face mold 13 is moved, the slide part 13d is located between the boundary line (end face forming position 14b) between the guide part 14a and the face forming the outer surface of the head part 52 and the end face forming face 13a. An interval for moving is provided.

  Thereby, in the stage before the movement of the end face mold 13, the volume in the cavity 4 of the mold 10 is such that the lower end (position corresponding to the end face forming position 14 b) of the face forming the outer surface of the head portion 52 and the end face molding. The volume of the gap between the surface 13a and the actual volume of the ridge 5 is larger. Therefore, even if the volume of the head part molded product 17 is equal to or larger than the volume of the head part 52, the head part molded product 17 can be easily installed in the cavity 4. As a result, the fiber resin prepreg forming the head part molding 17 is between the upper mold 11 and the lower mold 12, or between the end face mold 13, the upper mold 11 and / or the lower mold 12. It can prevent being pinched | interposed between and can prevent the burr | flash containing carbon fiber being formed after shaping | molding.

While the mold 10 is heated, the slide part 13d of the end face mold 13 is pushed along the guide part 14a by a moving means (not shown), and the end face mold 13 is moved along the head part core metal 13b. When moved to the end surface forming position 14b, the volume of the gap between the lower end of the surface forming the outer surface of the head portion 52 in FIG. 5A (the position corresponding to the end surface forming position 14b) and the end surface forming surface 13a, The volume in the cavity 4 of the mold 10 is reduced, and the fiber resin prepreg wound around the core metal 13b for the head portion is pushed into the mold 10 and pressure is applied to the cavity 4 of the mold 10. .
After the end face mold 13 is moved, as shown in FIG. 5B, the end face forming surface 13a of the slide part 13d of the end face mold 13 is a boundary between the guide part 14a and the face forming the outer surface of the head part 52. It is coincident with the end face forming position 14b which is a line.

By moving the end face mold 13 while heating the mold 10, the carbon fiber and the resin of the fiber resin prepreg forming the head part molded article 17 are flowed, and the head core metal 13 b is moved. The head part molded product 17 shown in FIG. 4C that has been wound is pushed inward by the end surface molding surface 13a.
Then, the outer layer of the head part molding 17 is moved inward along the surface for molding the outer surface of the head part 52 in the cavity 4 of the mold 10 by being pushed inward by the end face molding surface 13a. Further, the inner layer of the head part molded product 17 moves along the head part core 13 b as the end face mold 13 moves. Further, the short fiber resin prepreg 3 forming the intermediate layer of the head part molded article 17 follows the movement of the end face mold 13 while being suppressed by the long fiber resin prepreg 2 forming the outer layer and the inner layer. The outer layer moves toward the inside while pressing the outer surface of the head part 52 in the cavity 4 against the surface on which the outer surface of the head part 52 is molded, and the void in the cavity 4 disappears.

  Through the above steps, the inner surface of the recess 52c that opens to the end surface 52b of the head portion 52 has an excellent strength composed of the inner layer 54 that is a long fiber layer, and the outer surface of the head portion 52 is composed of the outer layer 53 that is a long fiber layer. The stringed bow 5 shown in FIG. 1 having excellent strength and a beautiful appearance without voids is obtained.

  The method for manufacturing the stringed instrument bow 竿 5 of the present embodiment includes a step of forming the inner layer by winding the long fiber resin prepreg 2 in contact with the core metal 13b for the head portion, and the outer layer of the long fiber resin prepreg 2 outside the inner layer. A head portion winding step including a step of disposing a short fiber resin prepreg 3 having a short fiber length to form an intermediate layer and a step of winding the long fiber resin prepreg 2 around the outside of the intermediate layer to form an outer layer. In the molding process, the body part molded product and the head part molded product 17 are installed in the cavity 4 of the mold 10 for integrally molding the head part 52 from the body part 51, and the end face mold 13 is heated. Is moved to the end face forming position 14b of the mold 10 along the core metal 13b for the head portion, and the volume in the cavity 4 is reduced to apply pressure to form the flange 5, so that there is no void. And watch, the rod 5 of a string instrument bow having a head portion 52 having a superior strength damaged by such mounting or striking hardly occurs a member for holding the Kema obtained.

  On the other hand, for example, a fiber reinforced plastic having a volume exceeding the volume in the cavity is placed in a cavity of a mold composed of an upper mold and a lower mold, and the upper mold and the lower mold are heated while being heated. When the head part of a stringed instrument bow is formed by a method of molding by applying vertical pressure from the top, an excessive volume of fiber reinforced plastic is easily sandwiched between the upper mold and the lower mold A burr containing carbon fiber is likely to be formed after molding. However, if the volume of the fiber reinforced plastic placed in the cavity is reduced to suppress the formation of burrs, the pressure in the cavity during molding will be insufficient, and the fiber reinforced plastic will be placed inside and on the surface of the molded product after molding. Many air gaps resulting from the air contained therein remain. The voids remaining in the molded body deteriorate the appearance and strength. Therefore, it has been difficult to produce a stringed instrument bow with excellent appearance and strength while suppressing the formation of burrs.

  In the present embodiment, the fiber resin prepreg is described as an example made of carbon fiber resin, but at least a part or all of the fiber resin prepreg may be made of glass fiber resin. Further, the present invention can also be applied by combining other fibers such as an aramid fiber.

"Example 1"
A stringed instrument bow 5 shown in FIG. 1 was produced by the following method using the mold 10 shown in FIG. As the fiber resin prepreg, a CFRP prepreg made of carbon fiber resin and made by Toho Tenax (a product aligned in one direction: trade name: Q-111H0900 (34)) was used. Moreover, as a short fiber resin prepreg, a cut piece obtained by cutting a CFRP prepreg manufactured by Toho Tenax (a product aligned in one direction: product name: Q-111H0900 (34)) to a fiber length of 10 mm is pressed. The long fiber resin prepreg was cut out and used as it was to have a width of 5 mm and a length of 300 mm.

First, a fiber resin prepreg was wound around the core for the main body to form a molded product for the main body (main body winding process).
Next, the long fiber resin prepreg 2 is wound on the head core 13b in contact with the head core 13b at a position closer to the tip 13e than the end molding surface 13a of the head core 13b once fixed to the end mold 13. To form an inner layer. The portion of the inner layer on the end surface molding surface 13a side was formed in contact with the end surface molding surface 13a.
Next, the short fiber resin prepreg 3 was disposed outside the inner layer so that the outer shape approximated the outer shape of the head portion 52 to form an intermediate layer.
Next, the long fiber resin prepreg 2 was wound around the outer side of the intermediate layer to form an outer layer, whereby a head part molded product 17 was obtained.

Next, between the first concave portion 11 a and the second concave portion 12 a of the mold 10, the main body molded product integrated with the main body core metal, the head core metal 13 b, and the end face mold. 13 and the head part molding 17 in an integrated state.
Thereafter, preheating is performed at a molding temperature of 135 ° C. for 8 minutes, the end face mold 13 is moved along the head core metal 13b to the end face forming position 14b of the mold 10 to apply pressure in the mold 10, Thereafter, heating was performed at 135 ° C. for 40 minutes to form a stringed instrument bow 5 which is a molded product in which the main body 51 and the head 52 are integrated.

"Example 2"
As a short fiber resin prepreg for forming the intermediate layer, a stringed instrument bow of the stringed instrument bow was used in the same manner as in Example 1 except that a plate obtained by pressing a cut piece obtained by cutting to a fiber length of 8 mm was used.竿 5 was molded.
"Example 3"
The stringed instrument bow of Example 1 was used except that a short fiber resin prepreg for forming the intermediate layer was obtained by pressing a cut piece obtained by cutting to a fiber length of 5 mm into a plate shape.竿 5 was molded.

Example 4
A stringed instrument bow 5 was formed in the same manner as in Example 1 except that a cut piece obtained by cutting to a fiber length of 2 mm was used as a short fiber resin prepreg for forming the intermediate layer.
"Example 5"
A stringed instrument bow ridge 5 was formed in the same manner as in Example 1 except that a cut piece obtained by cutting to a fiber length of 1 mm was used as a short fiber resin prepreg for forming the intermediate layer.

"Comparative Example 1"
The stringed instrument bow of the stringed instrument bow was used in the same manner as in Example 1 except that a short fiber resin prepreg for forming the intermediate layer was obtained by pressing a cut piece obtained by cutting to a fiber length of 11 mm into a plate shape.竿 5 was molded.
"Comparative Example 2"
A stringed instrument bow 5 was formed in the same manner as in Example 1 except that a cut piece obtained by cutting to a fiber length of 0.8 mm was used as a short fiber resin prepreg for forming the intermediate layer.

The appearance of the soots of Examples 1 to 5, Comparative Example 1 and Comparative Example 2 obtained in this way was evaluated. As a result, in Example 1 to Example 5, no carbon fibers that flowed outside the outer layer were found.
Further, in Example 1 where the fiber length of the intermediate layer was 10 mm, a slight void was seen at the tip, but it was very small and could be repaired by filling with putty, and there was no problem in quality. . In Example 2 where the fiber length of the intermediate layer was 8 mm, Example 3 where the fiber length of the intermediate layer was 5 mm, and Example 4 where the fiber length of the intermediate layer was 2 mm, no void was found. In Example 5 in which the fiber length of the intermediate layer is 1 mm, a slight void was generated on the inner surface of the concave portion 52c to which the wedge of the head portion 52 is attached, but the void was very small, and no crack was generated from that portion. As it was no problem.

On the other hand, in Comparative Example 1, large voids appearing inside appeared in the sanding finishing process after molding, which became a problem as a quality. This is because the fiber length of the intermediate layer short fiber resin prepreg 3 is too long, the fluidity is insufficient, the air contained in each layer at the time of molding cannot be expelled, and the fiber does not contain fibers on the outer layer side It is presumed that voids consisting of air were generated and the resin surface layer part was peeled off by sanding.
Further, in Comparative Example 2, since the fiber length of the intermediate layer short fiber resin prepreg 3 was too short, the carbon fibers flowed out to the outside of the outer layer, and burrs containing carbon fibers remained in the molded product. Since the volume has been reduced, the pressure due to the movement of the end face mold is not applied sufficiently evenly at the time of molding, and a large void that causes a problem in quality occurs on the inner surface of the recess 52c to which the wedge of the head part 52 is attached. Cracks occurred.

  2 ... long fiber resin prepreg, 3 ... short fiber resin prepreg, 4 ... cavity, 5a ... horse hair, 5 ... collar, 10 ... mold, 11 ... upper mold, 11a ... first recess, 12 ... lower mold, 12a ... second recess, 13 ... end face mold, 13a ... end face forming surface, 13b ... core core for head part, 13c ... base, 13d ... slide part, 13e ... tip part, 14 ... head forming part, 14a ... guide part 15 ... Stringed instrument bow, 16 ... Jig, 17 ... Head part molded product, 51 ... Main body part, 52 ... Head part, 52b ... End face, 52c ... Recessed part, 53 ... Outer layer, 54 ... Inner layer, 55 ... Wall part, 56 ... the middle layer.

Claims (4)

A stringed instrument bow manufacturing method comprising: an arcuate rod-shaped main body part; and a head part formed to extend from one end of the main body part in a direction intersecting the extending direction of the main body part,
A main body winding step of winding a fiber resin prepreg around the main body core to form a main body molded article;
A step of forming a head part molded product by winding a fiber resin prepreg around a core part for a head part, and forming an end face molding surface of an end face mold for molding the end face of the head part as the core part for the head part Use what is standing through,
A step of forming an inner layer by winding a long fiber resin prepreg in contact with the core metal for the head portion, and an intermediate layer in which a short fiber resin prepreg having a fiber length shorter than the long fiber resin prepreg is disposed outside the inner layer And a step of winding a head part including a step of forming an outer layer by winding a long fiber resin prepreg around the outside of the intermediate layer,
The main body part molded product and the head part molded product are placed in a cavity of a mold for integrally molding the head part from the main body part, and the end face mold is placed in the core metal for the head part while heating. And a molding step of molding a molded article by applying pressure by reducing the volume in the cavity by moving the mold to the end face forming position of the mold Manufacturing method.   The fiber length of the said short fiber resin prepreg is 1 mm-10 mm, The manufacturing method of the string instrument bow cocoon of Claim 1 characterized by the above-mentioned. A stringed instrument bow comprising a bow-shaped main body and a head formed by extending from one end of the main body in a direction crossing the extending direction of the main body,
The head portion has a recess opening in the end face;
The wall portion forming the head portion is disposed between the inner layer surrounding the concave portion made of fiber reinforced plastic, the outer layer disposed along the outer surface of the head portion, and the inner layer and the outer layer. And a stringed instrument bow wing, wherein an intermediate layer made of a fiber reinforced plastic having a fiber length shorter than that of the outer layer is formed in a thickness direction. A stringed instrument bow comprising the stringed instrument bow of claim 3 .

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