WO2015056528A1

WO2015056528A1 - Electric toothbrush

Info

Publication number: WO2015056528A1
Application number: PCT/JP2014/074978
Authority: WO
Inventors: 行紀和田; 山本　淳; 正洋西浦
Original assignee: サンスター株式会社
Priority date: 2013-10-17
Filing date: 2014-09-20
Publication date: 2015-04-23
Also published as: JPWO2015056528A1; CN105682604A; SG11201602981PA; TW201529047A

Abstract

[Problem] To provide an electric toothbrush capable of enhancing cleaning properties between teeth while adequately maintaining cleaning properties on a tooth surface or tooth neck. [Solution] An electric toothbrush (1) having a brush part (2) in which bristle bundles (14) are implanted in implantation holes (13) of an implantation base (12), a handle part (3) as a grip for operating the brush part (12), and a vibration generating means (5) housed in the handle part (3), the vibration generating means (5) for rotating an eccentric weight (32) about an axis aligned with a length direction of the handle part (3) and causing the brush part (2) to vibrate, wherein level-difference bristle bundles (14A) implanted in the implantation holes (13) so that a level difference (H) is formed in a distal-end part thereof are provided as the bristle bundles (14).

Description

electric toothbrush

The present invention relates to an electric toothbrush having a bristle bundle (hereinafter referred to as a step bristle bundle) planted so that a step is formed at the tip.

As an electric toothbrush, a linear motion type equipped with a conversion means for converting the rotational motion of the motor into a reciprocating linear motion of the brush portion, or a reversal motion type equipped with a conversion means for converting the rotational motion of the motor into a reciprocating reverse motion of the brush portion In addition, a weight vibration type in which an eccentric weight is rotated by a motor to vibrate the brush portion, a linear vibration type in which the brush portion is reciprocally vibrated by a linear actuator, and the like are widely used.

On the other hand, as a method of planting hair bundles, in a state where a plurality of brush hairs are bundled, a flat wire is arranged at a substantially central portion in the length direction, and a plurality of brush hairs are bent around the flat wire. A hair bundle (hereinafter referred to as a contour hair bundle) having the tip aligned so that the bent portion of the brush hair is driven into the flock hole together with a flat line so that the length from the flocking base is the same. The planting method is widely adopted. In addition, as a method for planting hair bundles using this flat wire, a flat wire is arranged around a position shifted in one direction from a substantially central portion in the length direction in a state where a plurality of brush hairs are bundled. By bending a plurality of brush bristles around the flat line and driving the bent part of the bristles into the flock hole together with the flat line, two types of brush bristles with different heights (lengths) are implanted. There has also been proposed a method for planting a stepped hair bundle in which a hair bundle is implanted as if it is, and a step is formed at the hair tip of one hair bundle (see, for example, Patent Documents 1 to 4). .)

Special table 2010-531181 Special table 2012-511944 JP 2012-75725 A JP 2010-154900 A

By the way, in the toothbrush in which the step bristle bundle is implanted, the density of the bristle at the tip is lowered, and the tip of the brush bristle is easily elastically deformed, so that the cleaning ability of the tooth surface and the neck is lowered. Although it has demerits, it has a merit that the tip of the brush bristles can be easily inserted between the teeth and the cleanability between the teeth is improved.

On the other hand, the present applicant has considered applying the stepped bristle bundle to the brush portion of the electric toothbrush. However, the electric toothbrushes such as the linear motion type, the reverse motion type, and the linear vibration type have sufficient improvement in cleaning performance. I found that it was not allowed. And since these electric toothbrushes have a relatively high frequency for a large stroke of the brush part, the brush bristles that vibrate at a position facing each other during the forward movement are adjacent to each other. After elastically deforming in contact with the tooth surface of the tooth, when moving back to the other tooth surface side, when the tip of the bristle returns to the original shape between the teeth, It has been found that there is a problem that the interdental space cannot be sufficiently cleaned because the tip of the bristle is not sufficiently inserted between the teeth due to contact and elastic deformation.

An object of the present invention is to provide an electric toothbrush that can improve cleanability between teeth while sufficiently ensuring cleanability of a tooth surface and a neck.

An electric toothbrush according to the present invention includes a brush part in which a hair bundle is implanted in a flock hole of a flocking table, a handle part as a handle for operating the brush part, and a length direction of the handle part. In the electric toothbrush having the vibration generating means built in the handle portion that rotates the eccentric weight around the axis along the axis and vibrates the brush portion, a step is formed at the tip as the bristle bundle. It is provided with a stepped hair bundle planted in the flock hole.

In this electric toothbrush, the hair bundle is provided with a stepped hair bundle planted on the hair transplant table so that a step is formed at the tip portion. Further, it protrudes outward from the tip of the lower hair bundle and is easily inserted between the teeth, so that the cleanability between the teeth can be improved. Further, as the vibration generating means, the vibration generating means for vibrating the brush part by rotating the eccentric weight around the axial center along the length direction of the handle part is used. It vibrates in the radial direction centering on the axial center along the length direction, and has a vibration component in the direction orthogonal to the axial direction of the handle part, having almost no vibration component in the axial direction of the handle part. For this reason, the tip of the hair bundle having the higher stepped hair bundle vibrates mainly between the teeth when the handle portion is not brushed, and the cleaning performance between the teeth can be remarkably improved. In addition, in this electric toothbrush, it is preferable to perform a brushing operation by combining an electric brushing operation and a manual brushing operation. However, in the manual brushing operation, although the stroke of the brush portion is increased, the frequency is the electric toothbrush. Since the tip of the bristle is elastically deformed at the position facing the tooth surface and can return to the original shape at the position facing the tooth, the tip of the bristle is A part will be fully inserted between teeth and the cleaning property between teeth can be improved. In stepped hair bundles, not only the base end of the stepped hair bundle, but also the tip of the higher hair bundle tends to vibrate around the position corresponding to the tip of the lower hair bundle. This can further improve the performance.

It is a preferred embodiment that the step of the stepped hair bundle is set to 1 mm to 5 mm. If the step of the stepped hair bundle is less than 1 mm, the cleaning ability between the teeth can be obtained only to the same degree as that of the uniform hair bundle, and if it exceeds 5 mm, the cleaning ability between the teeth is higher than that of the uniform hair bundle. In this case, the thickness is preferably set to 1 mm to 5 mm.

It is also preferable that the cross-sectional shape of the bristle of the step bristle bundle is configured as a sea-island shape, and the core hair composed of the island portion protrudes from the sea portion at the tip of the brush hair. When such brush hair is used, the cleanability between teeth can be improved as compared with the case where the tip of the brush hair is cut into pieces.

It is also a preferred embodiment to set the protruding length of the core hair from the sea part to 0.5 mm to 1.0 mm. If the protruding length of the core hair is too short, the cleaning property between the teeth will be lowered, and if it is too long, the hair will be weak, the cleaning property will be lowered and the feeling of use will be lowered. It is preferable to set to.

It is a preferred embodiment that the natural frequency of the brush portion consisting only of the bristles is close to the natural frequency of the electric toothbrush body other than the brush portion. If comprised in this way, the vibration of a brush part can be enlarged as much as possible, and the cleaning property of a tooth surface, between teeth, and a tooth neck can be improved.

The flocking area of the hair bundle in the flocking table can be set to 0.5 cm ² or more, and the number of flocking holes can be set to 35 or more. As described above, when the stepped hair bundle is implanted in the flocking table, the density of the brush hair at the tip is halved, so that the hair flocking area of the hair bundle with respect to the flocking table is increased, and the number of flock holes is increased. It is possible to sufficiently maintain the cleanability in between. In addition, in this specification, the flocking area of a hair | bristle bundle means the area of the part enclosed by the straight line | region circumscribed to the flock hole which comprises the outer edge of a brush part.

It is also a preferred embodiment that two rows of the stepped hair bundles are planted along the length direction of the flocking table at the center of the flocking table in the width direction. By comprising in this way, between teeth | gears can fully be cleaned by a level | step difference hair | bristle bundle.

The stepped hair bundle and the uniform hair bundle having the same tip position can be planted on the flocking table. Thus, when the stepped hair bundle and the contoured hair bundle are planted on the same flocking table, the gap between the teeth can be improved by the stepped hair bundle, and the tooth surface and the boundary between the tooth and the gingiva by the contoured hair bundle. Cleanability can be improved.

It is preferable to set the length of the above-mentioned contour hair bundle to the same length as that of the lower hair bundle of the stepped hair bundle. By comprising in this way, it becomes possible to clean a space | interval between teeth reliably by a stepped hair | bristle bundle.

According to the electric toothbrush according to the present invention, as the bristle bundle, the step bristle bundle is provided on the flocking table so that a step is formed at the tip portion. The tip of the bundle protrudes outward from the tip of the lower hair bundle and is easily inserted between the teeth, so that the cleaning property between the teeth can be improved. Further, as the vibration generating means, the vibration generating means for vibrating the brush part by rotating the eccentric weight around the axial center along the length direction of the handle part is used. It vibrates in the radial direction centering on the axial center along the length direction, and has a vibration component in the direction orthogonal to the axial direction of the handle part, having almost no vibration component in the axial direction of the handle part. For this reason, the tip of the hair bundle having the higher stepped hair bundle vibrates mainly between the teeth when the handle portion is not brushed, and the cleaning performance between the teeth can be remarkably improved. In addition, in this electric toothbrush, it is preferable to perform a brushing operation by combining an electric brushing operation and a manual brushing operation. However, in the manual brushing operation, although the stroke of the brush portion is increased, the frequency is the electric toothbrush. Since the tip of the bristle is elastically deformed at the position facing the tooth surface and can return to the original shape at the position facing the tooth, the tip of the bristle is A part will be fully inserted between teeth and the cleaning property between teeth can be improved. In stepped hair bundles, not only the base end of the stepped hair bundle, but also the tip of the higher hair bundle tends to vibrate around the position corresponding to the tip of the lower hair bundle. This can further improve the performance.

(A) of the electric toothbrush is a front view, (b) is a cross-sectional view taken along the line bb of (a). (A)-(c) is a front view of a replacement brush provided with hair bundles with different arrangements Explanatory drawing of calculation method of flocked area Expanded sectional view of hair bundle planting structure (a) is a side view of the tip of the bristle, (b) is a side view of the tip of the bristle of another configuration (A) is a perspective view and (b) is a cross-sectional view of a brush hair having a core-sheath structure. (B) is a perspective view, (c) is a cross-sectional view, and (d) and (e) are cross-sectional views of other configurations of sea-island brush hair. The graph which shows the test result of the cleaning evaluation evaluation test with or without the stepped hair bundle The graph which shows the test result of the evaluation test of the cleanability due to the density of the hair bundle The graph which shows the test result of the evaluation test of the cleanability with the difference of the flocked area The graph which shows the relationship between the flocked area of the commercially available manual toothbrush and the electric toothbrush of this invention, and the number of flock holes The graph which shows the relationship between the flocked area of the commercially available electric toothbrush and the electric toothbrush of this invention, and the number of flock holes (A) Photo of # 24 and # 25 of jaw model after brushing by electric toothbrush of the present invention, (b) Photo of # 24 and # 25 of jaw model after brushing by manual toothbrush of commercial product P The graph which shows the test result of the evaluation test of the cleaning property of commercially available manual toothbrush P and S and the electric toothbrush of this invention Graph of the test results of the cleaning evaluation test with and without vibration by the vibration generating means

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In this embodiment, the upper and lower sides and the front and rear sides are defined with reference to a state in which the replacement brush is on the upper side, the electric toothbrush is in the vertical direction, and the brush part side is on the front side.

As shown in FIG. 1, the electric toothbrush 1 includes a toothbrush body 4 having a brush part 2 and a handle part 3 for manually operating the brush part 2, vibration generating means 5 for vibrating the brush part 2, and vibration. And a battery 6 for driving the generating means 5.

The toothbrush body 4 includes a handle portion 3 and a replacement brush 10 that is detachably attached thereto. A flocking table 12 is provided at the upper end of the handle 11 of the replacement brush 10, and a plurality of flocking holes 13 are formed in a predetermined arrangement on the flocking table 12, and a hair bundle 14 is planted in the plurality of flocking holes 13. The brush portion 2 is formed by the plurality of hair bundles 14. The specific configuration of the brush unit 2 will be described later in detail.

The handle portion 3 will be described. A cylindrical casing 21 such as a substantially cylindrical shape is provided, the upper end portion of the casing 21 is closed by the upper wall 21a, and a metal connection projecting upward at the center portion of the upper wall 21a. The shaft 22 is integrally provided with the lower half embedded in the upper wall 21a, and a reinforcing ring 23 is fitted and fixed to the upper portion of the upper wall 21a so that a load from the connecting shaft 22 acting on the upper wall 21a can be applied. The reinforcement ring 23 can be efficiently received.

The lower end portion of the replacement brush 10 is formed in a cylindrical shape, and a holding cylinder 15 in which the connecting shaft 22 is detachably fitted is formed in the lower end portion of the replacement brush 10. The holding cylinder 15 is divided into two parts so that the holding cylinder 15 can be expanded and contracted, and the connecting shaft 22 is held in the holding cylinder 15 by the elasticity of the material of the replacement brush 10. Further, an engaging groove 22a is formed in the middle portion of the connecting shaft 22 in the length direction, and an engaging protrusion 15a that can be engaged with the engaging groove 22a is formed in the holding cylinder 15 of the replacement brush 10, and the connecting shaft 22 is connected. When the shaft 22 is fitted to the inner part of the holding cylinder 15, the engagement groove 22 a is engaged with the engagement protrusion 15 a, and in this state, the replacement brush 10 does not easily fall off with a force equivalent to a brushing operation. Is held by the connecting shaft 22. However, as a connection structure of the replacement brush 10 with respect to the connection shaft 22, a well-known structure can be adopted. For example, after the connection shaft 22 is inserted into the holding cylinder 15 of the replacement brush 10, the replacement brush 10 is rotated by a certain angle. Thus, the replacement brush 10 can be connected to the connecting shaft 22.

A lid member 24 for inserting and removing the battery 6 is provided at the lower end portion of the casing 21, and a small-diameter fitting portion 24 a that is detachably fitted and fixed to the lower end portion of the casing 21 at the upper end portion of the lid member 24. Is formed in a protruding shape. A seal ring 25 is provided on the base of the fitting portion 24a so as to be fitted externally. With the lid member 24 fixed to the casing 21, the seal ring 25 is pressed against the lower end portion of the casing 21, The casing 21 is configured to be held in a liquid-tight state.

The battery 6 is housed inside the lower part of the casing 21, and the motor 30 is housed inside the upper part of the casing 21 with the rotary shaft 30 a facing the length direction of the handle portion 3. Includes a switch 31 for switching an energization circuit to the motor 30 between an ON state and an OFF state.

The vibration generating means 5 has a motor 30 and an eccentric weight 32 fixed to the upper end portion of the rotating shaft 30a of the motor 30. By rotating the eccentric weight 32 by the motor 30, the upper portion of the casing 21 is vibrated. By transmitting this vibration to the replacement brush 10 via the connecting shaft 22, the brush portion 2 of the replacement brush 10 is configured to vibrate.

The battery 6 that drives the motor 30 is a primary battery, but a secondary battery such as a nickel hydride secondary battery or a lithium ion secondary battery can also be used. Moreover, when using a secondary battery, it is also preferable to incorporate an induction coil into the lid member 24 so that the secondary battery can be charged without contact by an external power source.

The present invention is characterized in that the stepped hair bundle 14A is used as the hair bundle 14 in the electric toothbrush 1 as described above, and the configuration of the flocking table 12 and the brush portion 2 will be described in detail below.

The arrangement of the flock holes 13 formed on the flock base 12 (the arrangement of the hair bundles 14) can be set to any known arrangement. In addition to the arrangement shown in FIG. 1A, for example, the arrangement shown in FIGS. 2A to 2C and other known arrangements can be set. The width of the vegetation table 12 can be set to an arbitrary width according to the number of hair bundles 14 to be planted, but if it is too small, the number of hair bundles 14 that can be planted decreases and the tooth surface and the neck are cleaned. If it is too large, the operability in the oral cavity is deteriorated, so it is preferable to set it to 8 mm to 18 mm.

The diameter of the flock hole 13 is preferably set to 1.2 mm to 1.5 mm, but may be larger. In addition, when the stepped hair bundle 14A is planted on the flocking table 12, the density of the bristles 16 at the tip is halved. In order to ensure sufficient cleanability between the teeth while improving the cleanability of the tooth surface and the neck, the hair transplantation area of the hair bundle 14 in the hair transplant table 12 should be set to 0.5 cm ² or more. However, considering operability in the oral cavity, it is preferably set to 0.5 cm ² or more and 3.5 cm ² or less. In addition, the number of flock holes 13 is preferably set in the range of 35 to 60, preferably 35 to 50. In addition, the flocked area of the hair | bristle bundle 14 means the area S of the part enclosed by the straight line L circumscribed to the flock hole 13 which comprises the outer edge of the brush part 2, as shown in FIG.

As the hair bundle 14 that can be implanted in the flock hole 13, a stepped hair bundle 14A and a contour hair bundle 14B having the following configuration can be adopted. Only the stepped hair bundle 14A can be planted on the flocking table 12, or the stepped hair bundle 14A and the contoured hair bundle 14B can be arbitrarily mixed and planted.

As shown in FIG. 4, the stepped hair bundle 14 </ b> A is centered at a position shifted in one direction from the substantially central portion in the length direction in a state where a plurality of filaments constituting the bristles 16 are bundled with their tips aligned. In a state where the flat wire 17 is disposed inside the bent portion, the bent portion of the brush hair 16 is press-fitted into the flock hole 13 together with the flat wire 17, and the high hair bundle 14AH and the low hair bundle having different heights are fitted. It is planted so that two types of hair bundles of 14AL are formed.

As shown in FIG. 4, the contour hair bundle 14 </ b> B is formed by bending a plurality of filaments constituting the brush hair 16 around the substantially central portion in the length direction in a state where a plurality of filaments are bundled with their tips aligned. In the state where the flat wire 17 is arranged inside the wire, the bent portion of the brush bristles 16 is press-fitted into the flock hole 13 together with the flat wire 17 so as to form a hair bundle having the same height. .

Only the stepped hair bundle 14A can be planted on the hair transplant table 12, or the stepped hair bundle 14A and the contoured hair bundle 14B can be arbitrarily mixed and planted. When the stepped hair bundle 14A and the contoured hair bundle 14B are mixed and planted, for example, as shown in FIG. Consists of the hair bundle 14A, and the two rows on the both sides (the hair bundle shown by white circles) can each be constituted by the contour hair bundle 14B. However, in this case, the height of the uniform hair bundle 14B is set to the same length as that of the low hair bundle 14AL, and the tip of the high hair bundle 14AH projects from the uniform hair bundle 14B and the low hair bundle 14AL. It is preferable to configure.

The height of the low hair bundle 14AL from the flocking table 12 can be set to 5 mm to 12 mm, the height of the high hair bundle 14AH from the flocking table 12 can be set to 6 mm to 13 mm, and the low hair bundle 14AL and the high hair bundle 14AH If the step height H at the tip is too small, the insertion between the teeth will be reduced, and if it is too large, the fur will be weak and sufficient cleaning properties will not be obtained, so it is set to 1 to 5 mm, preferably 2 to 4 mm. It is preferable to do.

The number of the bristle 16 of the low bristle bundle 14AL and the high bristle bundle 14AH is the same because the middle part of the bristle 16 is bent and planted in the tuft hole 13, and can be set to 7 to 225, for example. The diameter of the brush bristles 16 can be set to 0.1 mm to 0.26 mm, preferably 0.15 mm to 0.2 mm.

Here, a method of setting the step H between the low hair bundle 14AL and the high hair bundle 14AH will be described.
The natural frequency fn of the brush part 2 that does not include the flocking table 12 can be obtained by the following calculation formula.

fn = (kn ² / 2π) √ (EI / ρAL ⁴ ) (1)

kn: constant corresponding to eigenvalue E: Young's modulus (longitudinal elastic modulus) of brush hair
I: Section moment of inertia (depends on the fourth power of brush bristle diameter)
A: Cross-sectional area of brush hair L: Length of brush hair ρ: Density of brush hair

From Equation 1, the natural frequency of the brush portion 2 is much higher than the natural frequency of the electric toothbrush 1 excluding the brush portion 2. Therefore, in order to make the natural frequency of the brush part 2 close to the natural frequency of the electric toothbrush 1 excluding the brush part 2 and increase the vibration of the brush hair by resonance, the brush part 2 can be configured as follows. preferable.
(1) Lower the Young's modulus of the brush hair.
(2) Make the brush hair thicker.
(3) Increase the level difference.
(4) Increase the specific gravity.

Among the above parameters, parameters having a large influence on the natural frequency are the cross-sectional area of the bristle 16 and the step H. However, since the cross-sectional area of the brush bristles 16 becomes harder, the influence on the feeling of use is great, and some people prefer softer specifications, so the degree of freedom in parameter selection is low. Therefore, since the influence on the feeling of use is relatively small, it is important to set the level difference H appropriately. About the level | step difference H, although the direction which enlarged is approached the natural frequency of the electric toothbrush 1 except the brush part 2, when a level | step difference becomes large too much, the rigidity of a brush hair will fall and cleaning property will fall.
Therefore, the step H is preferably set to 1 to 5 mm, preferably 2 to 4 mm.

The material constituting the bristles 16 is a polyamide resin such as nylon or aramid, or a polyester resin such as polybutylene terephthalate (PBT), polypropylene terephthalate (polytrimethylene terephthalate, PPT or PTT) or polyethylene terephthalate (PET), polypropylene. Known synthetic resins can be used as the bristles of toothbrushes, such as polyolefin resins such as (PP) and polyethylene (PE).

The brush bristles 16 can be configured to be tapered, but the bristle becomes weak and the cleaning between the teeth decreases, so the length direction of the brush bristles 16 as shown in FIG. It is preferable to form a flat-cut shape cut in a direction orthogonal to the shape or a rounded shape obtained by rounding the tip of the brush bristles 16 into a hemispherical shape as shown in FIG. However, a tip shape having a known configuration other than the above can be adopted.

Further, as the bristles 16, brush bristles made of a single synthetic resin monofilament can be used, and brush bristles 16A and 16B made of a composite monofilament of a plurality of synthetic resin core-sheath structures or sea-island structures are employed. You can also. When the

brush hairs

16A and 16B having a core-sheath structure or a sea-island structure are employed, a structure in which the core portion 16a and the island portion 16c are exposed from the tip ends of the

brush hairs

16A and 16B can be employed.

As shown in FIG. 6, the core-sheathed bristle 16A is a bristle made of a composite monofilament configured so that the core 16a formed at the center is surrounded by the sheath 16b formed at the outer periphery. The synthetic resin material that constitutes the core portion 16a and the sheath portion 16b is extruded from a die at the same time and formed so that the cross-sectional shape at an arbitrary position of the brush bristles 16A is the same shape. is there.

The core portion 16a can be composed of a material mainly composed of polyamide resin such as nylon or aramid, and the sheath portion 16b can be composed of a material mainly composed of polyester resin such as polybutylene terephthalate.

As shown in FIG. 6A, the core hair 18 made of the core portion 16a protrudes from the tip of the brush hair 16A. As a method of projecting the core hair 18, for example, a polyamide resin is used for the core portion 16a and a polyester resin such as PBT is used for the sheath portion 16b, and the tip side of the brush hair 16A is made of an alkaline material such as caustic soda (NaOH). The bristle 16A in which the core portion 16a is exposed by being immersed in a chemical solution or the like and the core hair 18 protrudes from the tip can be configured. However, a means for removing the sheath 16b by a mechanical method other than the chemical method can also be adopted.

The outer diameter b2 of the sheath portion 16b is set to 0.16 mm to 0.25 mm, and the outer diameter b1 of the core portion 16a is set to 40 to 90%, more preferably 60 to 80% of the outer diameter of the sheath portion 16b. The exposed length of the core hair 18 from the sheath portion 16b is preferably set in a suitable range of 0.5 to 1.0 mm.

As shown in FIGS. 7A to 7C, the sea-island-structured bristle 16B has three island portions 16c arranged at the apexes of a triangle, and a sea portion 16d is formed so as to surround these three island portions 16c. As shown in FIG. 7D, the brush bristles made of the composite monofilament in which the sea portion 16d is formed so as to surround the two island portions 16c arranged at intervals, as shown in FIG. As shown in e), the four island portions 16c are arranged at the vertices of a quadrangle, and are brush hairs made of a composite monofilament in which a sea portion 16d is formed so as to surround the four island portions 16c. A synthetic resin material that forms the sea portion 16d is extruded from a die at the same time, and the cross-sectional shape at an arbitrary position of the brush bristles 16B is the same. One in which the.

The island 16c can be made of a material mainly composed of a polyamide resin such as nylon or aramid, and the sea 16d can be made of a material mainly composed of a polyester resin such as polybutylene terephthalate.

As shown in FIGS. 7A and 7B, a core hair 18 made of an island portion 16c protrudes from the tip of the brush hair 16B. As a method for causing the core hair 18 to protrude, for example, the sea portion 16d is made of polyester resin and the island portion 16c is made of nylon resin. The sea bristle brush hair 16B is dipped in caustic soda (NaOH), and then pulled up, the sea portion 16 d is dissolved and removed from the tip, the island 16 c is exposed, and the bristle 16 having a plurality of core hairs 18 protruding from the tip of the sea portion 16 d constituting the outer surface of the brush bristle 16 can be manufactured. In this case, the taper shape at the tip of the sea portion 16d and the exposed length of the core hair 18 can be adjusted as appropriate depending on the concentration of sodium hydroxide, the immersion time, the pulling speed from the sodium hydroxide, and the like.

The diameter of the sea part 16d may be set to a preferable range of 0.150 to 0.300 mm, the diameter of the core hair 18 is 0.03 to 0.07 mm, and the exposed length of the core hair 18 is 0.5 to 1.0 mm. preferable.

The cross-sectional shape of the bristles can be formed in any shape other than circular. Further, brush hairs having different cross-sectional shapes can be arbitrarily mixed, or brush hairs made of monofilaments and brush hairs made of composite monofilaments can be mixed.

This electric toothbrush 1 brushes teeth while vibrating the brush portion 2 by the vibration generating means 5, but it is preferable that the brushing operation is performed in combination with a manual brushing operation. If comprised in this way, the small thing of a comparatively weak output can be employ | adopted as the motor 30 of the vibration generation means 5, and the handle | steering-wheel part 3 of the electric toothbrush 1 is comprised by a small diameter and slim, and is suitable for manual brushing operation. While the toothbrush 1 can be realized and a small motor 30 having a relatively weak output is used as the motor 30 of the vibration generating means 5, the operability of the manual brushing operation can be improved and the brushing performance can be sufficiently secured. Moreover, since the step bristle bundle 14A is provided, the density of the brush hairs 16 at the tip of the brush part 2 is reduced, and the brush hairs 16 are easily inserted between the teeth, so that the cleaning between the teeth can be improved, Further, by setting the height of the low hair bundle 14AL and the equal hair bundle 14B of the stepped hair bundle 14A to be the same, it is possible to sufficiently ensure the cleanability of the tooth surface and the tooth neck. Moreover, as shown in FIG. 4, in the contour hair bundle 14B, the hair bundle 14 tries to vibrate around the base end portion P1 of the hair bundle 14 protruding from the flock base 12, but in the step hair bundle 14A, the step hair Since not only the base end portion P1 of the bundle 14A but also the tip portion of the high hair bundle 14AH easily vibrates around the position P2 corresponding to the tip portion of the low hair bundle 14AL, the cleaning performance between the teeth can be further improved. Become.

Next, an evaluation test of the electric toothbrush 1 in which the step bristle bundle 14A is implanted will be described.

(Evaluation test for cleaning performance with or without steps)
For the 48 flock holes 13 of the flock 12 shown in FIG. 1, the 18 brush bristles 16 configured as shown in Table 1 are arranged in the middle so that the bristles as shown in Table 1 are obtained. Were bent and planted together with the flat wire 17 to produce replacement brushes of Examples 1 and 2 and Comparative Examples 1 and 2.

Then, using a jaw model (Nissin Co., Ltd.), apply occlude (Pascal Company Inc. Inc.) as a pseudo plaque to the upper left second premolar (# 25) and upper left first molar (# 26) of the jaw model. The upper left second premolar (# 25) and the upper left first premolar under the brushing conditions shown in Table 2 with respect to the electric toothbrush 1 to which the replacement brushes of Examples 1 and 2 and Comparative Examples 1 and 2 were attached, respectively. (# 26) was brushed. The upper left second premolar (# 25) and the upper left first premolar (# 26) were photographed from the side, and the removal rate of dirt in specific areas between the teeth was calculated by image analysis. The results are shown in Table 1 and FIG.

From Table 1 and FIG. 8, the replacement brushes of Examples 1 and 2 in which a stepped hair bundle having a level difference of 3 mm was implanted were compared with the replacement brush in Comparative Example 1 in which a uniform hair bundle without a step was implanted. It can be seen that the cleaning property between the two is improved. However, in Comparative Example 2 where the level difference is 6 mm, the cleaning property is lower than in Comparative Example 1 where there is no level difference, and it is understood that the level difference is preferably set to be less than 6 mm.

(Evaluation test for cleanability by density of hair bundles)
Next, since the density of the tip end portion of the brush portion is lowered when the stepped hair bundle is used, the following test was performed in order to examine the change in the cleaning force due to the decrease in the density of the tip end portion of the brush portion.

Using a replacement brush before planting a bristle having a flocking table of the same dimensions as in Example 1, as Comparative Example 3, with respect to 6 rows and 48 flocking holes of the replacement brush used in Example 1 A replacement brush in which brush hairs of the same sea-island structure are planted so that no step is formed is manufactured, and as a comparative example 4, the second row of flock holes from the outside of the replacement brush planting holes of comparative example 3 is omitted. And the replacement brush comprised similarly to the comparative example 3 except having planted the hair | bristle bundle in 4 rows 32 flocking holes, and the outer side of the flocking holes in the comparative example 3 as the comparative example 5 was manufactured. The configuration is the same as that of Comparative Example 3 except that the second row of flocked holes is omitted, and every other flocked hole in the remaining four rows is omitted, and hair bundles are implanted in four rows of 18 flocked holes. I made a replacement brush.

Then, an evaluation test was performed on the electric toothbrush 1 to which the replacement brushes of Example 1 and Comparative Examples 3 to 5 were attached by the same test method as the cleaning test for the presence or absence of steps. The results are shown in Table 3 and FIG.

From Table 3 and FIG. 9, even when using the bristle made of the same sea island structure composite monofilament, Example 1 in which a step hair bundle having a step height of 3 mm was implanted, not only between the teeth, but also between Comparative Examples 3, It can be seen that the plaque removal rate is also high on the tooth surface and the tooth neck. Further, in Example 1 in which only the tip of the brush portion is hairless, compared to Comparative Examples 4 and 5 in which the brush portion is generally hairless, plaques on all tooth surfaces, interdental teeth, and tooth necks. It can be seen that the removal rate is high.

(Evaluation test of cleanability by the difference in the flocked area)
As Comparative Examples 6 to 8, three types of replacement brushes having a flocking table in which the flocked area, the number of flocked holes, and the arrangement of hair bundles were arranged as shown in Table 4 were produced.

Then, an evaluation test was performed on the electric toothbrush 1 to which the replacement brushes of Comparative Example 3 and Comparative Examples 6 to 8 were attached, respectively, by the same test method as the cleaning evaluation test based on the presence or absence of the step. The results are shown in Table 4 and FIG.

From Table 4 and FIG. 10, as the number of rows of flock holes increases, the brushing pressure is dispersed and the load acting on each brush hair decreases, so that the plaque removal rate is generally lowered. I understand.

(Comparison with commercial products)
FIG. 11 is a graph showing the relationship between the flocked area and the number of flock holes of a commercially available manual toothbrush and the electric toothbrush of the present invention, and the region surrounded by the one-dot chain line represents the flocked area applicable to the electric toothbrush of the present invention It is the range which shows the number of flock holes. FIG. 12 is a graph showing the relationship between the flocked area and the number of flock holes of a commercially available electric toothbrush and the electric toothbrush of the present invention. It is the range which shows an area and the number of flock holes.

From FIG. 11 and FIG. 12, although the range of the flocked area and the number of flock holes applicable to the electric toothbrush of the present invention partially overlaps with the commercial product in the manual toothbrush, it is not seen in the commercial electric toothbrush. Numeric range not allowed.

(Evaluation test for cleanability with commercially available manual toothbrushes)
As the commercially available manual toothbrushes, commercially available manual toothbrushes P and S as shown in Table 5 were used.
And the evaluation test was done by the test method similar to the evaluation test of the cleaning property by the presence or absence of the said level | step difference with respect to the electric toothbrush 1 which attached the replacement brush of Example 1, and the manual brush of commercial item P, S. The results are shown in FIGS.

From FIG. 13, FIG. 14, the electric toothbrush 1 which attached the replacement brush of Example 1 has a high plaque removal rate in all of a tooth surface, an interdental area, and a tooth neck compared with the manual toothbrush of commercial item P and S. You can see that

(Evaluation test of cleanability with and without electric drive)
The electric toothbrush 1 to which the replacement brush of Example 1 was attached was used. And the cleaning property evaluation test by the presence or absence of vibration by the vibration generating means was performed by the same test method as the cleaning property evaluation test by the presence or absence of the step, except that the brushing pressure was set to 100 g and the stroke was set to 15 mm. The result is shown in FIG.

From FIG. 15, it is clear that the manual brushing while applying vibration to the replacement brush with the vibration generating means, compared with the case of brushing only by hand, is the plaque removal rate in all tooth surfaces, interdental teeth, and tooth necks. Can be seen to be higher.

As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above at all, Of course, the structure can be changed in the range which does not deviate from the summary of this invention.

1: Electric toothbrush 2: Brush part 3: Handle part 4: Toothbrush body 5: Vibration generating means 6: Battery 10: Replacement brush 11: Pattern 12: Flocking table 13: Flocking hole 14: Hair bundle 14A Stepped hair bundle 14AH: High Hair bundle 14AL: Low hair bundle 14B: Equal hair bundle 15: Holding tube 15a: Engaging projection 16: Brush hair 16A: Brush hair 16B: Brush hair 16a: Core portion 16b: Sheath portion 16c: Island portion 16d: Sea portion 17: Flat wire 18: Core hair 21: Casing 21a: Upper wall 22: Connection shaft 22a: Engaging groove 23: Reinforcement ring 24: Lid member 24a: Fitting portion 25: Seal ring 30: Motor 30a: Rotating shaft 31: Switch 32: eccentric weight b1: outer diameter b2: outer diameter H: step

Claims

Eccentricity centering on a brush part formed by planting hair bundles in the flock holes of the flocking table, a handle part as a handle for operating the brush part, and an axis along the length direction of the handle part In the electric toothbrush having the vibration generating means built in the handle portion, which rotates the weight to vibrate the brush portion,
As the hair bundle, provided with a stepped hair bundle planted in the flock hole so that a step is formed at the tip,
An electric toothbrush characterized by that.
The electric toothbrush according to claim 1, wherein the step of the stepped hair bundle is set to 1 mm to 5 mm.
The electric toothbrush according to claim 1 or 2, wherein a cross-sectional shape of the bristle of the stepped bristle bundle is configured as a sea-island shape, and a core hair composed of an island portion protrudes from the sea portion at a tip portion of the brush hair.
The electric toothbrush according to claim 3, wherein a protruding length of the core hair from the sea part is set to 0.5 mm to 1.0 mm.
The electric toothbrush according to any one of claims 1 to 4, wherein the natural frequency of the brush part including only the hair bundle is made close to the natural frequency of the electric toothbrush body other than the brush part.
The electric toothbrush according to any one of claims 1 to 5, wherein a planting area of the hair bundle in the flocking table is set to 0.5 cm 2 or more, and the number of flock holes is set to 35 or more.
The electric toothbrush according to any one of claims 1 to 6, wherein the stepped hair bundle is planted in two rows at least along the length direction of the flocking table at a center portion in the width direction of the flocking table.
The electric toothbrush according to any one of claims 1 to 7, wherein the stepped hair bundle and a contoured hair bundle having the same tip position are planted on the flocking table.
The electric toothbrush according to claim 8, wherein the length of the contour hair bundle is set to be the same as the length of the lower bundle of stepped hair bundles.