How to remove toothbrush bristles, toothbrush bristle removal tools, how to manufacture toothbrushes and toothbrush manufacturing equipment.

Abstract

The purpose of the present invention is to provide a bristle removal method with which it is possible to limit quality defects and cost increases. The bristle removal method includes: a detecting step in which, for a defective bristle (20A) exceeding a prescribed height, the position in the bristle-tip height direction and the position in the head-section length direction are detected; a first moving step in which, on the basis of the bristle-tip position detected in the detecting step, the head section (18) and a separated plurality of gripping parts (31), which are provided as longer than the width of the head section and extend parallel to a bristle implanting surface and along the width direction of the head section, are moved relative to each other, and said bristle tip is placed between the separated plurality of gripping parts; a gripping step in which at least one of the plurality of gripping parts is moved, and said bristle tip is gripped by the plurality of gripping parts at a first position in the height direction; a second moving step in which the head section and the plurality of gripping parts gripping said bristle tip are moved relative to each other, and the plurality of gripping parts gripping said bristle tip are placed at a second position that is nearer to the bristle implanting surface (18a) than the first position; a winding step in which said defective bristle is wound around the outer peripheral surface of the gripping parts by rotating, at a position that is nearer to the bristle implanting surface than the first position, the plurality of gripping parts gripping said bristle tip around an axis that intersects the height direction; and a third moving step in which the head section and the plurality of gripping parts around which said defective bristle is wound are moved relative to each other, and the plurality of gripping parts around which said defective bristle is wound are placed at a third position that is further away from the bristle implanting surface than the first position.

Description

Hair removal method, hair removal device, toothbrush manufacturing method, and toothbrush manufacturing device The present invention relates to a hair removal method, a hair removal device, a toothbrush manufacturing method, and a toothbrush manufacturing device, and more particularly to a hair removal method, a hair removal device, a toothbrush manufacturing method, and a toothbrush manufacturing device suitable for removing defective bristles (long bristles) from a toothbrush in which tapered bristles are implanted using a flat wire. This application claims priority based on Japanese Patent Application No. 2016-076165, filed in Japan on April 5, 2016, and the contents of that application are incorporated herein by reference. Conventionally, toothbrushes obtained by implanting bristle bundles with flat wire are manufactured through a process of producing the brush body including the head by injection molding, implanting bristle bundles with flat wire into multiple bristle holes formed in the head of the manufactured brush body, trimming the bristle tips to adjust the height of the implanted bristles, and rounding the tips to polish the corners of the bristle tips. The manufactured toothbrushes are then inspected for defects in bristle implantation, packaged, and shipped (Patent Document 1). Therefore, even if the height of the bristles implanted in the bristle implantation process is uneven, it is possible to adjust the bristle height to a predetermined height in the trimming process. In recent years, toothbrushes with tapered bristles that easily reach between teeth have become widely used (see, for example, Patent Document 2). Because tapered bristles are characterized by their reduced diameter and thinness at the tip, the conventional method of trimming the bristles to adjust their height is undesirable because it would make the tapered bristles thicker by the amount their tips are cut. Therefore, when using tapered bristles, the bristle implantation conditions are adjusted during the implantation process so that the height of the implanted bristles is uniform. If defective bristles (long bristles) protrude from the predetermined height in the direction of implantation due to poor implantation, these defective bristles are removed manually. Manual removal of defective bristles involves, for example, using a tool such as pliers to grasp and pull out the defective bristles. However, if the tip of a long bristles is grasped and pulled, they may break off and become impossible to remove. Therefore, after grasping the tip of a long bristles with a tool, the bristles are pulled out from the outer circumference of the bristle surface while still grasped, and then the gripping position is slid to the base of the long bristles, and the bristles are pulled out while grasping the base. Because this process had to be performed for each defective hair, it led to increased costs. Patent Document 3 discloses a method for removing protruding hairs from a toothbrush that can extract protruding hairs from the entire outer peripheral contour of the toothbrush. However, there was a problem in that it could not cope with the removal of the long hairs when tapered hairs were implanted. JP-A-2002-199939, Patent 3145213, JP-A-7-155223 The present invention has been made in consideration of the above points, and an object thereof is to provide a hair removal method, a hair removal device, a toothbrush manufacturing method, and a toothbrush manufacturing device that can suppress defective quality and cost increase. According to a first aspect of the present invention, there is provided a method for removing defective hairs protruding from a predetermined height in a toothbrush in which a hair bundle of tapered hairs is implanted on a hair implanting surface of a head portion using a flat line, the method comprising: a detecting step of detecting a position in the height direction of the tip of the defective hair protruding from the predetermined height and a position in the length direction of the head portion; a first moving step of relatively moving the head portion and a plurality of spaced-apart holding pieces that extend parallel to the hair implanting surface in the width direction of the head portion and are provided longer than the width of the head portion, and disposing the tip of the hair between the plurality of spaced-apart holding pieces; a holding step of moving at least one of the plurality of holding pieces to hold the tip of the hair at a first position in the height direction by the plurality of holding pieces; a second moving step of relatively moving the plurality of holding pieces holding the tip of the hair and the head portion, and disposing the plurality of holding pieces holding the tip of the hair at a second position closer to the hair implanting surface than the first position; a winding step of rotating the plurality of holding pieces holding the tip of the hair around an axis intersecting the height direction at a position closer to the hair implanting surface than the first position to wind the defective hair around an outer peripheral surface of the holding piece; and a step of relatively moving the plurality of holding pieces having the defective hair wound therearound and the head portion, and disposing the plurality of holding pieces having the defective hair wound therearound at a third position farther from the hair implanting surface than the first position. Furthermore, in the hair removal method according to one aspect of the present invention described above, the clamping piece is characterized in that the ratio W1 / W2, which is the ratio of the maximum width W1 in the direction of clamping the hair tip to the maximum width W2 in the height direction, is 0.5 or more. Furthermore, in the hair removal method according to one aspect of the present invention described above, the winding step is characterized in that the plurality of clamping pieces are rotated at least 1 / 2 turn around the axis. Furthermore, in the hair removal method according to one aspect of the present invention described above, the method is characterized in that in the second moving step, the plurality of clamping pieces are rotated around the axis at a rotational speed corresponding to the relative moving speed between the plurality of clamping pieces and the head portion. Furthermore, the hair removal method according to one aspect of the present invention is characterized by including a step of re-detecting the presence or absence of any defective hairs that have protruded from at least the predetermined height after the hair removal step. A second aspect of the present invention provides a toothbrush manufacturing method characterized by including a bristle implantation step of implanting bundles of tapered bristles at a predetermined height on the bristle surface of the head portion using a flat wire, an inspection step of inspecting the tapered bristles implanted in the bristle implantation step, and a step of removing defective bristles that have protruded from the predetermined height using the bristle removal method of the first aspect of the present invention. According to a third aspect of the present invention, a toothbrush in which bundles of tapered bristles are implanted at a predetermined height on the bristle surface of the head portion using a flat wire, the device for removing defective bristles that protrude above the predetermined height comprises: a detection unit for detecting the position of the tip of the defective bristles that protrude above the predetermined height; a plurality of gripping pieces capable of gripping the tip of the bristles; a first drive unit for driving at least one of the plurality of gripping pieces between a position for gripping the tip of the bristles and a position for releasing the gripping of the tip of the bristles; a second drive unit for relative driving the plurality of gripping pieces and the head portion in a direction parallel to the bristle surface and in the height direction; a third drive unit for rotationally driving the plurality of gripping pieces around an axis intersecting the height direction to wrap the defective bristles around the outer circumferential surface of the gripping pieces; and the detection unit A tweezers device is provided, comprising: a drive control unit that controls the first drive unit, the second drive unit, and the third drive unit in accordance with the detection result to move the separated plurality of clamping pieces and the head unit relative to each other, positions the hair tip between the separated plurality of clamping pieces, then clamps the hair tip at a first position in the height direction with the plurality of clamping pieces, then positions the plurality of clamping pieces that have clamped the hair tip at a second position closer to the bristle surface than the first position, rotates the clamping pieces at a position closer to the bristle surface than the first position around an axis intersecting the height direction to wrap the defective hair around the outer surface of the clamping pieces, and positions the plurality of clamping pieces that have wrapped the defective hair at a third position further from the bristle surface than the first position. Furthermore, in the hair tweezers according to one aspect of the present invention described above, the gripping piece is characterized in that the ratio W1 / W2, which is the ratio of the maximum width W1 in the direction of gripping the hair tip to the maximum width W2 in the height direction, is 0.5 or more. Furthermore, in the hair-tweezing device according to one aspect of the present invention described above, the drive control unit is characterized in that, when wrapping the defective hair around the outer surface of the clamping piece, it rotates the plurality of clamping pieces by 1 / 2 turn or more around the axis. Furthermore, in a hair tweezers device according to one aspect of the present invention described above, the plurality of gripping pieces that grip the hair tips are rotated around the axis at a rotational speed corresponding to the relative movement speed between the plurality of gripping pieces and the head portion while moving the plurality of gripping pieces from the first position to the second position. Furthermore, in the tweezers according to one aspect of the present invention described above, the plurality of gripping pieces extend parallel to the bristle surface in the width direction of the head portion and are provided to be longer than the width of the head portion, and the detection unit detects the position of the bristle tip in the height direction and the position of the head portion in the length direction. Furthermore, in the tweezers device according to one aspect of the present invention described above, the plurality of gripping pieces are characterized in that each has an uneven shape that interlocks with each other when joined together. A toothbrush manufacturing apparatus is provided, comprising: a bristle implantation device for implanting bundles of tapered bristles at a predetermined height on the bristle surface of the head portion using a flat wire; an inspection device for inspecting the tapered bristles implanted by the bristle implantation device; and a bristle removal device according to the third aspect of the present invention for removing defective bristles that protrude from the predetermined height. This invention makes it possible to suppress quality defects and cost increases. This figure shows an embodiment of the present invention, where (a) is a front view showing the clamping piece 11 of the tweezers 10 positioned above the toothbrush 1, and (b) is a right side view. This is an enlarged cross-sectional view of the vicinity of one bundle of bristles in the head portion 18 of the toothbrush 1. This is a block diagram relating to the driving of the clamping piece 31. This is a diagram showing the operation of the tweezers. This is a diagram showing the operation of the tweezers. This is a diagram showing the operation of the tweezers. This is a diagram showing the operation of the tweezers. This is a schematic configuration diagram of the toothbrush manufacturing apparatus 50. This is a front view showing another form of the clamping piece. This is a front view showing another form of the clamping piece. This is a front view showing another form of the clamping piece. This is a front view showing another form of the clamping piece. Hereinafter, embodiments of the hair removal method, hair removal device, toothbrush manufacturing method, and toothbrush manufacturing device of the present invention will be described with reference to Figures 1 to 10. In the following, the case in which the present invention is applied to a toothbrush in which tapered bristles are implanted in the head portion will be described. The following embodiments represent one aspect of the present invention and are not intended to limit it. They can be modified at will within the scope of the technical idea of ​​the present invention. Furthermore, in the following drawings, the scale and number of components in each structure differ from the actual structure in order to make the components easier to understand. [Methods and devices for removing hair] The tweezers will be described with reference to Figures 1 to 3. Figure 1(a) is a front view showing the gripping piece 31 of the tweezers 30 positioned above the toothbrush 1, and Figure 1(b) is a right side view of Figure 1(a). In Figure 1, an example configuration is shown in which the gripping piece 31 of the tweezers 30 is positioned above the toothbrush 1; however, a configuration in which the gripping piece 31 is positioned below the toothbrush 1 is also possible. In the following explanation, the length direction of the toothbrush 1 will be referred to as the X direction, the width direction of the toothbrush 1 as the Y direction, and the direction perpendicular to the X and Y directions (the thickness direction of the toothbrush 1) as the Z direction, as appropriate. First, let's briefly describe the toothbrush (brush) 1 that will be subjected to hair removal by the hair removal device 30. The toothbrush 1 comprises a handle body 10 and a brush portion 22 formed by a plurality of bristle bundles 12 planted on the handle body 10. The handle body 10 comprises a rod-shaped handle portion (not shown in Figure 1), a neck portion 17 extending from the tip of the handle portion and thinner than the handle portion, and a head portion 18 provided at the tip of the neck portion 17 and on which the plurality of bristle bundles 12 are planted. The plurality of bristle bundles 12 are planted on the bristle-planted surface 18a of the head portion 18. The handle body 10 is made of a hard resin such as polypropylene, polyacetal, or polybutylene terephthalate. The total length of the handle body 10 is approximately 100 to 200 mm. The head portion 18 is formed in a roughly rectangular, flat shape with four curved corners. The dimensions of the head portion 18 are approximately 5 to 16 mm in width, 10 to 33 mm in length, and 3 to 5 mm in thickness. The number of hair implantation holes 18a is, for example, 10 to 60. The diameter of the hair implantation holes 18a is, for example, 1 to 3 mm. The planar shape of the hair implantation holes 18a may be a polygon such as a circle or square, and the arrangement pattern may be a grid or staggered. Figure 2 is an enlarged cross-sectional view of the vicinity of one bristle bundle in the head portion 18 of the toothbrush 1. The bristle bundle 12 is formed by bundling together multiple tapered bristles 20. The bristle bundle 12 is implanted on the bristle surface 18a by a flat wire implantation method. Specifically, as shown in Figure 2, multiple tapered bristles 20, each having a tapered portion 21 at both ends, are bundled together and folded in half with a flat wire 24 which is a metal piece, and then driven into a bristle hole 23 formed on the bristle surface 18a of the head portion 18, thereby implanting the bristle bundle 12 at a height (predetermined height) H from the bristle surface 18a. The tapered bristles 20 have a tapered section 21 that narrows in diameter towards the tip, located closer to the tip than the straight section 19. The material of the tapered bristles 20 can be synthetic resins such as polyester, polyamide, or polyolefin, but polybutylene terephthalate (PBT) is commonly used. As for the processing method of the tapered section 21, a method of chemically treating the tip of a PBT monofilament with a strong alkali is generally used. An example of a monofilament is cylindrical with a total length of 31 mm and a central diameter of about 6 to 8 mils (1 mil = 0.025 mm). When the tapered bristles 20 are folded in half and driven into the bristle implantation holes 23 and fixed, the bristle length H (length from the bristle implantation surface 18a to the tip of the bristles) is, for example, about 10 to 12 mm. Typical tapered bristles 20 used in toothbrush 1 have a tip diameter of 0.02 mm, a taper length L (length from the tip of the bristles to the starting position of the tapered shape) of about 8 mm, and are sharp, with a diameter of 0.05 to 0.07 mm at a position 1 mm from the tip and a diameter of 0.11 to 0.14 mm at a position 3 mm from the tip. Therefore, when pulling out long bristles of 1 to 3 mm in length that result from poor bristle implantation, the gripping point is very thin, and the bristles will break when gripped and pulled out. Furthermore, the bristle implantation strength (bristle retention strength) of the bristle bundle 12 in toothbrush 1 is defined in JIS S3016, which specifies that the maximum tensile force obtained by pulling with a tensile testing machine must be 8 [N] or more. In toothbrush 1, a certain level of bristle retention strength is required, and a higher strength is preferable. Therefore, removing the long bristles of the tapered bristles 20 described above becomes even more difficult. Returning to Figure 1, the tweezers 30, as shown in Figures 1(a) and (b), comprises a clamping piece 31, a detection unit 32, a drive unit group 33, a head holding unit (not shown) that holds the head portion 18 of the toothbrush 1 from the side opposite to the bristle surface 18a, and a drive control unit CONT. The clamping piece 31 is located on the +Z side of the brush portion 22. The clamping piece 31 extends in the Y direction, which is the width direction of the head portion 18 and parallel to the bristle surface 18a, and is provided in pairs facing each other in the X direction. Each clamping piece 31 is formed in a semi-cylindrical shape with its planar portions facing each other. When the clamping pieces 31 are joined at their planar portions, they form a cylindrical shape with a diameter of 3.0 mm, for example. The clamping piece 31 is longer than the width of the head portion 18 and is positioned to cover the area in the width direction where the head portion 18 is provided. For example, if the maximum width of the head portion 18 is 15 mm, the length of the clamping piece 31 is set to approximately 30 mm. The clamping piece 31 is made of, for example, high-hardness chromium-molybdenum steel. The clamping pieces 31 are synchronously movable between a clamping position (see Figure 5(a)) where at least one moves toward the other so that the planar portions can be joined, and a release position (see Figures 1(a) and 4(a)) where at least one moves toward the other so that they can be separated. In this embodiment, each clamping piece 31 is described as being movable toward each other and toward each other, but it is also possible for one of them to move toward the other and the other toward the other. The pair of clamping pieces 31 are formed in a cylindrical shape when they come into contact with each other on the planar portions, i.e., when they move to the clamping position. The clamping pieces 31 may be cantilevered or supported at both ends, but it is preferable to adopt a configuration with support at both ends in order to clamp more firmly. Figure 3 is a block diagram relating to the driving of the clamping piece 31. The drive unit group 33 includes a clamping drive unit (first drive unit) 41, a horizontal drive unit (second drive unit) 42, a rotation drive unit (third drive unit) 43, and a height drive unit (second drive unit) 44. The drive unit group 33 is centrally controlled by the drive control unit CONT. The clamping drive unit 41 moves the pair of clamping pieces 31 synchronously along the X direction between the clamping position and the release position. The horizontal drive unit 42 moves the pair of clamping pieces 31 and the head portion 18 (toothbrush 1) relative to each other in the X direction. The rotation drive unit 43 rotates the pair of clamping pieces 31 around the central axis of the cylindrical shape, either in the clamping position or the released position. The height drive unit 44 moves the pair of clamping pieces 31 and the head portion 18 (toothbrush 1) relative to each other in the Z direction (height direction of the bristle bundle 12). In this embodiment, a configuration is described in which the pair of clamping pieces 31 move in the X direction by the drive of the horizontal drive unit 42 and the pair of clamping pieces 31 move in the Z direction by the drive of the height drive unit 44. However, a configuration in which the head unit 18 (toothbrush 1) moves in the X direction by the drive of the horizontal drive unit 42 and the head unit 18 (toothbrush 1) moves in the Z direction by the drive of the height drive unit 44 is also possible, or a configuration in which both the pair of clamping pieces 31 and the head unit 18 (toothbrush 1) move in the X direction by the drive of the horizontal drive unit 42 and both the pair of clamping pieces 31 and the head unit 18 (toothbrush 1) move in the Z direction by the drive of the height drive unit 44 is also possible. The detection unit 32 detects the amount of hair tip protrusion and the position of the hair tip of tapered hairs 20 that protrude beyond a predetermined height and length (hereinafter referred to as defective hairs 20A). For example, the standard length for a hair to be considered a defective hair 20A is 1 mm or more. As shown in Figure 1(b), for example, the detection unit 32 detects defective hairs 20A from the +Y side and detects the position in the X direction and Z direction of the hair tip of a defective hair 20A that exceeds the standard length protrusion. As a method of position detection by the detection unit 32, for example, it is possible to detect the position according to the result of image processing of an image taken of the brush part 22, or to detect the position in the X direction and Z direction of the defective hair 20A according to the result of scanning the brush part 22 with detection light (presence or absence of reflected light, presence or absence of light reception at a predetermined position, etc.). The detection result of the detection unit 32 is output to the drive control unit CONT. Next, the method for removing defective hairs 20A using the hair removal device 30 described above will be explained with reference to Figures 4 to 8. Note that the detection unit 32, the drive unit group 33, and the drive control unit CONT are not shown in Figures 4 to 8. First, the toothbrush 1 (head portion 18) is held by the head holding portion. Then, the detection unit 32 performs imaging and detection light scanning processing on the held brush portion 22 to detect defective hairs 20A that have protruded from the height H and exceeded the length standard. If defective hairs 20A are detected, the detection unit 32 outputs the position of the tip of the defective hair 20A in the X direction to the drive control unit CONT. When the drive control unit CONT receives the X-direction and Z-direction positions of the tip of the defective hair 20A, it controls the clamping drive unit 41 to move the pair of clamping pieces 31 to the release position. At a Z-direction position higher than the tip of the defective hair 20A (hereinafter referred to as the Z position), the clamping pieces 31 are moved so that the center position of the pair of clamping pieces 31 coincides with the X-direction position of the tip of the defective hair 20A (hereinafter referred to as the X position). Then, as shown in Figures 4(a) and (b), the height drive unit 44 is controlled to move the clamping pieces 31 toward the fur-planting surface 18a so that the protruding tip is positioned between the pair of clamping pieces 31 (first movement step). At this time, the Z position of the center of the clamping piece 31 is set higher than the height H so as not to come into contact with a tapered hair 20 other than the protruding defective hair 20A. Next, the drive control unit CONT controls the clamping drive unit 41 to move the pair of clamping pieces 31 to the clamping position, as shown in Figures 5(a) and 5(b). As a result, the tip of the defective hair 20A is clamped between the pair of clamping pieces 31 at a first position higher than the height H (clamping process). Next, the drive control unit CONT controls the height drive unit 44 to move the pair of clamping pieces 31 that are gripping the tips of the defective hairs 20A to a second position closer to the fur-planting surface 18 than the first position, as shown in Figures 6(a) and (b) (second movement step). As described above, the tips of the hairs gripped by the pair of clamping pieces 31 are thin, so as the pair of clamping pieces 31 rotate and wrap the defective hairs 20A around the outer surface, as will be described later, the second position is set to a position where a deflection of a length corresponding to an angle exceeding 90 degrees of the circumference of the outer surface, for example, 1 / 2 rotation (180 degrees), occurs in the defective hairs 20A, so as not to apply excessive tension to the tips of the hairs during the first 1 / 4 rotation (90 degrees) of rotation. Next, the drive control unit CONT controls the rotary drive unit 43 to rotate the pair of clamping pieces 31 that clamp the hair tips at the second position around the central axis of the cylindrical shape, as shown in Figures 7(a) and (b), and wrap the defective hairs 20A around the outer circumferential surface of the pair of clamping pieces 31 (wrapping process). The amount of rotation of the pair of clamping pieces 31 is preferably 1 / 2 rotation or more, and more preferably 3 / 4 rotation or more. If the amount of rotation of the pair of clamping pieces 31 falls below the above lower limit, the minimum diameter of the defective hairs 20A that are not wrapped around the outer circumferential surface will be small, and the tension generated as the pair of clamping pieces 31 rotates may cause the defective hairs 20A to break off. For example, if the taper length L is 8 mm, the protruding length of the defective hair 20A is 1 mm, and the circumference of the pair of clamping pieces 31 is 3 × π, then if the amount of rotation of the pair of clamping pieces 31 is 1 / 2 turn, then approximately 70% of the taper length will be wrapped around the outer surface. Also, if the amount of rotation of the pair of clamping pieces 31 is 3 / 4 turn, then almost 100% of the taper length will be wrapped around the outer surface. Therefore, the minimum diameter of the defective hair 20A that is not wrapped around the outer surface will be close to the diameter of the central part of the defective hair 20A compared to the hair tip diameter. Furthermore, if the amount of rotation is too large, the distance traveled by the pair of clamping pieces 31 in the second moving process will increase, which may negatively affect productivity. Also, if the diameter of the pair of clamping pieces 31 increases, the distance traveled by the pair of clamping pieces 31 in the second moving process will increase, bringing the second position closer to the bristle surface 18a, which may crush the bristle bundles 12 other than the defective hairs, or cause the clamping pieces 31 to come into contact with the bristle surface 18a. Therefore, it is preferable that the pair of clamping pieces 31 be thin enough to ensure sufficient strength when clamping the tip of the defective hair 20A and when wrapping the defective hair 20A around the outer surface. Furthermore, it is preferable that the amount of rotation of the pair of clamping pieces 31 be set taking into consideration the taper length L of the defective hair 20A. When defective hairs 20A are wrapped around the outer circumferential surfaces of the pair of clamping pieces 31 at a predetermined angle, the drive control unit CONT controls the height drive unit 44 to move the clamping pieces 31 to a third position relative to the head unit 18, which is further away from the first position than the flocked surface 18a and higher than the height H, as shown in Figures 8(a) and (b) (third movement step). As the clamping pieces 31 rise, the defective hairs 20A that were wrapped around the outer circumferential surfaces of the clamping pieces 31 are removed from the head unit 18, including the parts that were folded in half and positioned on the opposite side of the flat wire 24. If the movement speed of the pair of clamping pieces 31 in the third movement process is slow, productivity will decrease, and if the movement speed is fast, there is a possibility that the defective hairs 20A will break off. Therefore, it is preferable to set the movement speed to the fastest possible speed within the range in which the defective hairs 20A do not break off. As described above, in the hair plucking device 30 of this embodiment, even if defective hairs 20A protrude from a predetermined height H after hair implantation, these defective hairs 20A that result in poor hair implantation can be removed without relying on manual labor and without the hairs breaking off at the tip. Therefore, the hair plucking device 30 of this embodiment makes it possible to remove defective hairs 20A without increasing costs or causing quality defects. Furthermore, in the hair removal device 30 of this embodiment, since the pair of clamping pieces 31 are formed in a cylindrical shape with no edges on their outer surface when they move to the clamping position, stress concentration on the defective hairs 20A wrapped around the outer surface and subsequent breakage (tearing) can be suppressed. In addition, in the hair removal device 30 of this embodiment, since the clamping pieces 31 extend parallel to the bristle-planted surface 18a in the width direction of the head portion 18 and are provided to be longer than the width of the head portion 18, it is not necessary to adjust the position of the clamping pieces 31 according to the position of the defective hairs 20A in the width direction of the head portion 18, thereby improving the efficiency of the hair removal process. In the above embodiment, the procedure for performing the winding process after the completion of the second moving process was illustrated, but the procedure for performing the winding process as part of the second moving process is also applicable. For example, after gripping the tip of the defective hair 20A with the pair of clamping pieces 31 at the first position, the pair of clamping pieces 31 may be moved a predetermined distance toward the second position to create a sag in the defective hair 20A so as not to apply excessive tension to the tip of the hair. Then, the movement of the pair of clamping pieces 31 to the second position and the winding of the defective hair 20A around the outer surface by rotating the pair of clamping pieces 31 may be performed in parallel. In this case, by setting the rotation speed of the pair of clamping pieces 31 such that the length of time the defective hair 20A is wrapped around the outer surface due to the rotation of the pair of clamping pieces 31 is shorter than the length of the deflection of the defective hair 20A caused by the movement of the pair of clamping pieces 31 to the second position, it is possible to avoid applying excessive tension to the defective hair 20A. Specifically, if the diameter of the cylindrical clamping piece 31 is D (mm), the rotational speed of the clamping piece 31 due to the operation of the rotational drive unit 43 (i.e., the winding speed of the defective hair 20A) is R (revolutions / sec), pi is π, and the downward speed of the clamping piece 31 due to the operation of the height drive unit 44 is V (mm / sec), then it is preferable that the relationship between the deflection length of the defective hair 20A generated per unit time and the length of the defective hair 20A wound around the outer surface per unit time satisfies the following equation (1). V≧π・R・D…(1) From equation (1), it is preferable to set the rotational speed of the clamping piece 31 to the value shown in equation (2) below. R≦V / (π・D)…(2) Furthermore, considering productivity, it is preferable that the wrapping of defective hairs 20A around the outer surface of the clamping piece 31 is completed when the clamping piece 31 reaches the second position. Therefore, if the distance between the height position where the rotation of the clamping piece 31 begins and the second position is L1 (mm), and the amount of rotation of the pair of clamping pieces 31 that wrap the defective hairs 20A around their outer surfaces is N rotations, then the relationship between the time it takes for the clamping piece 31 to move to the second position and the time it takes to wrap the defective hairs 20A around the outer surface of the clamping piece 31 is expressed by the following equation (3). R・(L1 / V)=N…(3) Therefore, by rotating the clamping piece 31 at the rotational speed R represented by the following equation (4), it becomes unnecessary to separately provide time for wrapping the defective hairs 20A around the outer surface of the clamping piece 31. R=N・(V / L1)...(4) For example, as described above, if the rotation amount of the pair of clamping pieces 31 that wrap the defective hairs 20A around the outer surface is 1 / 2 rotation, then from equation (4), the rotation speed R should be set to V / (2 × L1). In this way, productivity can be improved by performing the process of wrapping defective hairs 20A around the outer surface of the clamping piece 31 in parallel with the second moving process. In particular, by rotating the clamping piece 31 at a rotational speed R that satisfies equation (4), it becomes unnecessary to set aside time for wrapping defective hairs 20A around the outer surface of the clamping piece 31, and productivity can be further improved. [Method and apparatus for manufacturing toothbrushes] Next, the toothbrush manufacturing method and toothbrush manufacturing apparatus will be explained with reference to Figure 9. Figure 9 is a schematic diagram of the toothbrush manufacturing apparatus 50. The toothbrush manufacturing apparatus 50 includes a bristle implantation device 60, a conveying device 70, and the bristle removal device 30 described above. The bristle implantation device 60 implants a predetermined number of tapered bristles 20 bundles and flat wires 24 into the bristle implantation holes 23 of the head portion 18 held in the head holding portion using a bristle implantation needle, thereby folding the tapered bristles 20 in half with the flat wires 24 and implanting them into the bristle implantation holes 23. The bristle implantation device 60 also sequentially implants bundles of tapered bristles 20 into each bristle implantation hole 23 by moving the head portion 18 to adapt to the arrangement of the multiple bristle implantation holes 23. The toothbrush 1, with its bundles of tapered bristles 20 implanted by the bristle implantation device 60, is transported to the bristle removal device 30 by the transport device 70. Once transported to the bristle removal device 30, the toothbrush 1 undergoes detection and removal of any defective bristles 20A that have protruded from the head portion 18, as described above. Thus, in the toothbrush manufacturing apparatus 50 of this embodiment, even if defective bristles 20A that protrude above a predetermined height H occur in the tapered bristles 20 implanted by the bristle implantation device 60, inspection and removal can be performed without relying on manual labor, thereby suppressing quality defects and reducing costs. Furthermore, when transporting the toothbrush 1 from the bristle implantation device 60 to the tweezers device 30, the head holder part holding the head portion 18 in the bristle implantation device 60 may be transported and used as the head holder part in the tweezers device 30 for inspection and tweezing, or the toothbrush 1 removed from the head holder part in the bristle implantation device 60 may be transported to the tweezers device 30, and the transported toothbrush 1 may be held in the head holder part in the tweezers device 30 for inspection and tweezing. Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the constituent members shown in the above examples are merely examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention. For example, in the above embodiment, a configuration in which the opposing surfaces (clamping surfaces) of the clamping pieces 31 are flat was illustrated, but the invention is not limited to this. For example, as shown in Figure 10, the clamping pieces may have interlocking concave and convex shapes at the clamping position. When the clamping pieces 31 have this configuration, there are locations where the clamping direction between the clamping pieces 31 and the clamping direction between the clamping surfaces of each clamping piece 31 are different, making it possible to clamp the defective hairs 20A more firmly. Furthermore, in the above embodiment, the procedure for removing the defective hair 20A from the head portion 18 was illustrated by raising the clamping piece 31, which has wound the defective hair 20A on its outer circumferential surface, from a second position near the base end of the defective hair 20A. However, the procedure is not limited to this. For example, the drive control unit CONT may control the height drive unit 44 to stop the clamping piece 31 at the second position, and then control the rotation drive unit 43 to rotate the clamping piece 31 in the winding direction of the defective hair 20A to remove the defective hair 20A from the head portion 18. By adopting this procedure, the direction in which the defective hairs 20A are removed is inclined with respect to the Z direction in which the flat wires 24 are driven, thereby reducing the resistance caused by the flat wires 24 during removal. Furthermore, although the above embodiment illustrates a configuration in which the clamping piece 31 moves to a second position while winding up the defective hair 20A, the configuration is not limited to this. For example, the clamping piece 31 may clamp the defective hair 20A, then move to the second position, and then rotate to wind up the defective hair 20A with its outer surface. Furthermore, in the above embodiment, a configuration in which a pair (two) of clamping pieces 31 are used to clamp and remove defective hairs 20A is illustrated, but the configuration is not limited to this, and a configuration using three or more clamping pieces is also possible. For example, as shown in Figure 11, a configuration in which three clamping pieces 31 are used to clamp and remove defective hairs 20A by dividing a cylinder at 120° intervals at the clamping position. Also, when using three or more clamping pieces 31, as described above, they may be configured to have interlocking grooves and grooves at the clamping position. In any of the above configurations of multiple clamping pieces 31, the clamping surfaces may be roughened by blasting or other processes to increase the surface area and make them less slippery in order to improve the clamping performance. Furthermore, in the above embodiment, a configuration in which the clamping piece 31 is formed in a cylindrical shape at the clamping position was illustrated, but other configurations, such as one in a rectangular prism shape, may also be used. Figure 12 shows an example of a clamping piece 31 formed in a rectangular prism shape at the clamping position. When the clamping piece 31 is in a rectangular prism shape, it is preferable to form a curved surface, such as an arc shape, at the corner of the clamping piece 31 in order to prevent the breakage of defective hairs 20A during winding. Furthermore, when the pair of clamping pieces 31 clamp the hair tips, they may warp in a direction that causes the clamped positions to move apart from each other. This warping also occurs when the clamping pieces 31 are made of high-hardness chromium-molybdenum steel. Therefore, as shown in Figure 13, it is preferable that the maximum width W1 in the direction of clamping the hair tips is greater than the maximum width W2 in the height direction for the cross-sectional shape of the pair of clamping pieces 31. By making the maximum width W1 greater than the maximum width W2, it is possible to reduce the warping (bending) that occurs when the hair tips are clamped without significantly increasing the circumference of the outer surface. The maximum width W2 in the height direction of the clamping piece 31 is preferably 1 to 3 mm. The ratio (W1 / W2) of the maximum width W1 in the clamping direction to the maximum width W2 in the height direction of the clamping piece 31 is preferably 0.5 or more, more preferably 1.0 or more, and even more preferably 1.2 or more. The circumference of the outer surface of the joined pair of clamping pieces 31 is preferably 14 mm or less, more preferably 12 mm or less, and even more preferably 10 mm or less. As described above, when the hair length H is about 10 to 12 mm and the taper length L is about 8 mm, by setting the maximum width W1 in the clamping direction and the maximum width W2 in the height direction of the clamping piece 31 to the above range, the number of rotations of the clamping piece 31 when wrapping defective hairs 20A around the outer surface can be set to 1 / 2 rotation or more, preferably 3 / 4 rotation or more. The outer surfaces of the pair of clamping pieces 31 are preferably oval in shape, such as an elliptical or oblong shape with the clamping direction as the major axis, so that no edges are formed. Furthermore, although the above embodiment illustrates a configuration in which the clamping piece 31 moves horizontally and vertically relative to the toothbrush 1, the configuration is not limited to this, and the toothbrush 1 may also move horizontally and vertically relative to the clamping piece 31 via the head holding portion. Furthermore, while the above embodiment illustrates a configuration in which defective bristles 20A implanted in a toothbrush 1 are removed using the bristles removal device 30 according to the present invention, the application is not limited to toothbrushes 1. It can be widely used for the inspection and manufacture of brushes that use tapered bristles, or thin brushes with tapered bristles, such as brushes, paintbrushes, or cosmetic brushes. The present invention can be applied to a hair removal method, a hair removal device, a toothbrush manufacturing method, and a toothbrush manufacturing device. 1...Toothbrush (brush), 18...Head section, 18a...Bristle surface, 20...Tapered bristles, 20A...Defective bristles, 30...Hair removal device, 31...Clamping piece, 41...Clamping drive unit (first drive unit), 42...Horizontal drive unit (second drive unit), 43...Rotation drive unit (third drive unit), 44...Height drive unit (second drive unit), 50...Toothbrush manufacturing device, CONT...Drive control unit, H...Height (predetermined height)