JP5435553B2

JP5435553B2 - Electric razor

Info

Publication number: JP5435553B2
Application number: JP2009128245A
Authority: JP
Inventors: 伸紀八尋
Original assignee: Hitachi Maxell Energy Ltd
Current assignee: Hitachi Maxell Energy Ltd
Priority date: 2009-05-27
Filing date: 2009-05-27
Publication date: 2014-03-05
Anticipated expiration: 2029-05-27
Also published as: JP2010273809A

Description

本発明は、エッチング法で形成されるスリット刃構造の内刃を備えている電気かみそりに関する。 The present invention relates to an electric shaver provided with an inner blade having a slit blade structure formed by an etching method.

エッチング法で形成されるスリット刃構造の内刃は、例えば特許文献１に見ることができる。そこでは小刃の断面を、表側のせん断面と裏側の非せん断面と、これら両者の間に凹み形成される左右の湾曲面とでベルマウス状に形成してある。せん断面の両側には切刃が設けあり、切刃の角度を鋭角にしてひげ切断時の切れ味を向上している。 An inner blade having a slit blade structure formed by an etching method can be found in Patent Document 1, for example. In this case, the cross-section of the blade is formed in a bell mouth shape with a front side shearing surface, a back side non-shearing surface, and left and right curved surfaces formed between them. Cutting edges are provided on both sides of the shear surface, and the sharpness at the time of cutting the beard is improved by making the angle of the cutting edge an acute angle.

本発明に係る内刃は、展開状態における小刃を、波形やジグザグ形や稲妻形などに屈曲させるが、小刃を波形に形成することは特許文献２に公知である。そこでは、半円状に打ち抜かれた小刃の一群を、内刃ホルダーの上面に一定間隔おきに固定して内刃を構成している。小刃の板面は、平面から見て波形に折り曲げてある。このように、小刃の板面を波形に形成することにより、大きな切断負荷が作用するとき、小刃が摺動方向と逆向きにたわむのを防止できる。同様の小刃構造は特許文献３にも見ることができる。 The inner blade according to the present invention bends the small blade in the unfolded state into a corrugated shape, a zigzag shape, a lightning bolt shape, or the like. Here, a group of small blades punched in a semicircular shape is fixed to the upper surface of the inner blade holder at regular intervals to constitute an inner blade. The plate surface of the small blade is bent into a waveform when viewed from the plane. Thus, by forming the plate surface of the small blade in a waveform, it is possible to prevent the small blade from being bent in the direction opposite to the sliding direction when a large cutting load is applied. A similar blade structure can also be seen in US Pat.

特開２００７−２１５５９５号公報（段落番号００２６〜００２７、図１）JP 2007-215595 A (paragraph numbers 0026 to 0027, FIG. 1) 実公昭４２−５３１１号公報（第１頁右欄２８〜３３行、第２図）Japanese Utility Model Publication No. 42-5311 (page 1, right column, lines 28-33, FIG. 2) 特開昭５９−１０１１８２号公報（第２頁右上欄１０〜１２行、第９図）JP-A-59-101182 (page 2, upper right column, lines 10 to 12, line 9)

特許文献２および３の内刃は、主として小刃の構造強度を向上する目的で、小刃の板面を波形に折り曲げている。そのため、単に半円状に打ち抜いた小刃に比べて、素材厚みを一定とする場合の小刃の構造強度を格段に向上できる。問題は、半円状に打ち抜いた小刃の円弧周縁を切刃にしてひげ切断を行なうので、切刃の角度が約９０度にならざるを得ず、切れ味に問題がある。また、切れ味がよくないので、ひげ切断に多くの時間が掛かる。 In the inner blades of Patent Documents 2 and 3, the plate surface of the blade is bent into a corrugated shape mainly for the purpose of improving the structural strength of the blade. Therefore, the structural strength of the blade when the material thickness is constant can be significantly improved as compared with a blade cut simply in a semicircular shape. The problem is that whisker cutting is performed with the arc edge of a small blade punched out in a semicircular shape as the cutting edge, so the angle of the cutting edge must be about 90 degrees, and there is a problem in sharpness. In addition, since the sharpness is not good, it takes a lot of time for cutting the beard.

その点、特許文献１の内刃によれば、切刃の角度が鋭角になっているので、従来の小刃に比べると切れ味を向上できる。ちなみに、エッチング法で形成される内刃の切刃の角度は、蝕刻面による抉り深さを大きくするほど小さくできるので、切刃の角度をさらに小さくして切れ味を向上できることが想定される。 In that respect, according to the inner blade of Patent Document 1, the angle of the cutting blade is an acute angle, so that the sharpness can be improved as compared with the conventional small blade. Incidentally, the angle of the cutting edge of the inner blade formed by the etching method can be reduced as the depth of the cutting by the etched surface is increased, so that it is assumed that the angle of the cutting blade can be further reduced to improve the sharpness.

しかし、切刃の角度を小さくするほど左右の湾曲面（蝕刻面）がせん断面に近づき、しかも、左右の湾曲面によって小刃の肉壁が左右から大きく抉られる。そのため、せん断面の幅を一定とするときの小刃の断面積が小さくなって、その構造強度が小さくなるのを避けられない。小刃のせん断面の幅寸法を大きくすると、湾曲面で抉られた後の断面積を大きくして、小刃の構造強度をある程度は確保できる。しかし、その場合にはせん断面の幅寸法が大きい分だけ、外刃に対する摺動抵抗が増加する。さらに、小刃の幅寸法が大きい分だけ、外刃の刃穴が小刃で塞がれている時間が増加し、ひげの捕捉機会が減少して切断能率が低下するおそれがある。 However, as the angle of the cutting edge is reduced, the left and right curved surfaces (etched surfaces) approach the shearing surface, and the flesh wall of the small blade is greatly squeezed from the left and right by the left and right curved surfaces. Therefore, it is inevitable that the cross-sectional area of the blade is reduced when the width of the shear surface is constant, and the structural strength is reduced. When the width dimension of the shear surface of the blade is increased, the cross-sectional area after being struck by the curved surface can be increased, and the structural strength of the blade can be ensured to some extent. However, in that case, the sliding resistance with respect to the outer cutter increases as the width dimension of the shear surface increases. Furthermore, as the width dimension of the small blade is larger, the time during which the outer blade edge is closed with the small blade increases, and the chance of capturing the whiskers decreases, which may reduce the cutting efficiency.

本発明の目的は、切刃の角度を小さくしてシャープな切れ味を発揮できるにもかかわらず、小刃の構造強度を充分に確保できる内刃を備えている電気かみそりを提供することにある。
本発明の目的は、小刃のせん断面の幅寸法を一定とするときの、小刃の構造強度を十分に確保しながら、切刃の角度を小さくしてシャープな切れ味を発揮でき、したがって、外刃に対する摺動抵抗が大きくなるのを避け、さらに、ひげの捕捉機会を増加して切断能率を向上できる内刃を備えている電気かみそりを提供することにある。 An object of the present invention is to provide an electric razor having an inner blade that can sufficiently secure the structural strength of a small blade, although the angle of the cutting blade can be reduced to exhibit a sharp sharpness.
The purpose of the present invention is to provide a sharp cutting edge by reducing the angle of the cutting edge while sufficiently securing the structural strength of the cutting edge when the width dimension of the shearing surface of the cutting edge is constant. An object of the present invention is to provide an electric razor provided with an inner blade that avoids an increase in sliding resistance with respect to the outer blade and further increases the chance of capturing beards to improve the cutting efficiency.

本発明に係る電気かみそりは、外刃１０と内刃１２を有し、内刃１２は外刃１０の内面に沿って往復駆動される。内刃１２は前後一対の装着壁２０・２０と、両装着壁２０・２０を繋ぐ前後方向に長い小刃２１の一群を備えている。小刃２１は、互いに平行なせん断面３１および非せん断面３２と、これら両者３１・３２の左右側縁間の肉壁を抉る左右の湾曲面３３・３４とで、断面がベルマウス状に構成してある。小刃２１のせん断面３１の左右両側縁には、それぞれ鋭角の切刃３５・３５を形成する。左右の湾曲面３３・３４の抉り深さＭ・Ｎを異ならせて、小刃２１の断面を左右で非対称のベルマウス状に形成し、せん断面３１の一側縁に他の切刃部位より小さな角度α１の切刃３５を形成する。 The electric razor according to the present invention has an outer blade 10 and an inner blade 12, and the inner blade 12 is reciprocated along the inner surface of the outer blade 10. The inner blade 12 includes a pair of front and rear mounting walls 20, 20 and a group of small blades 21 that are long in the front-rear direction connecting the mounting walls 20, 20. The blade 21 is composed of a shearing surface 31 and a non-shearing surface 32 parallel to each other, and left and right curved surfaces 33 and 34 that sandwich the wall between the left and right side edges of both 31 and 32, and the cross section is configured in a bell mouth shape. It is. On the left and right side edges of the shearing surface 31 of the small blade 21, acute-angle cutting blades 35 and 35 are formed, respectively. The cross-section of the small blade 21 is formed in an asymmetric bell mouth shape by changing the depths M and N of the curved surfaces 33 and 34 on the left and right sides. A cutting edge 35 having a small angle α1 is formed.

展開した状態における小刃２１の平面視形状は、凹縁部２６と凸縁部２７とが交互に連続する屈曲形状に形成する。凹縁部２６における湾曲面３３の抉り深さＭを他より大きくして、凹縁部２６における切刃３５の角度α１を他の切刃部位より小さく設定する。 The planar view shape of the blade 21 in the unfolded state is formed in a bent shape in which the concave edge portions 26 and the convex edge portions 27 are alternately continued. The turning depth M of the curved surface 33 in the concave edge portion 26 is set larger than the others, and the angle α1 of the cutting edge 35 in the concave edge portion 26 is set smaller than the other cutting edge portions.

小刃２１の長手方向に隣接する凹縁部２６および凸縁部２７の間で、小刃２１の断面形状を連続して滑らかに変化させる。 The cross-sectional shape of the small blade 21 is continuously and smoothly changed between the concave edge portion 26 and the convex edge portion 27 adjacent to each other in the longitudinal direction of the small blade 21.

小刃２１の長手方向に隣接する凹縁部２６および凸縁部２７において、凹縁部２６における小刃２１の断面形状と、凸縁部２７における小刃２１の断面形状とを線対称に形成する（図５（ａ）および図５（ｃ）参照）。 In the concave edge portion 26 and the convex edge portion 27 adjacent to the longitudinal direction of the small blade 21, the cross-sectional shape of the small blade 21 in the concave edge portion 26 and the cross-sectional shape of the small blade 21 in the convex edge portion 27 are formed in line symmetry. (See FIG. 5 (a) and FIG. 5 (c)).

小刃２１の基端部２８における湾曲面３３・３４の抉り深さを基端部（２８）以外の小刃（２１）の抉り深さより小さくして、基端部２８の断面積Ｓ３を、小刃２１の基端部（２８）以外の断面積より大きく設定する（図５（ｄ）参照）。
The bending depth of the curved surfaces 33 and 34 at the base end portion 28 of the small blade 21 is made smaller than the depth of the small blade (21) other than the base end portion (28), and the cross-sectional area S3 of the base end portion 28 is set. The cross-sectional area other than the base end part (28) of the small blade 21 is set (see FIG. 5D).

小刃２１の基端部２８を、装着壁２０・２０から内刃１２の往復駆動方向と略直交する向きに直線状に連出する。 The base end portion 28 of the small blade 21 is linearly extended from the mounting walls 20 and 20 in a direction substantially orthogonal to the reciprocating drive direction of the inner blade 12.

展開した状態における小刃２１の平面視形状を、それぞれ湾曲する凹縁部２６と凸縁部２７とが交互に連続する波形に形成する。 The planar view shape of the small blade 21 in the unfolded state is formed into a waveform in which the concave edge portions 26 and the convex edge portions 27 that are curved are alternately continued.

基端部２８を除く非せん断面３２の小刃幅Ｂ１・Ｂ２を略一定に設定し、凹縁部２６および凸縁部２７における非せん断面３２の幅方向中央を、せん断面３１の幅方向中心Ｐから左右方向へ交互に偏寄させる。さらに、凹縁部２６と凸縁部２７との中間位置における非せん断面３２の幅方向中央を、せん断面３１の幅方向中心Ｐに位置させる。 The blade widths B1 and B2 of the non-shear surface 32 excluding the base end portion 28 are set to be substantially constant, and the center in the width direction of the non-shear surface 32 at the concave edge portion 26 and the convex edge portion 27 is set in the width direction of the shear surface 31. It is made to deviate alternately from the center P in the left-right direction. Further, the center in the width direction of the non-shear surface 32 at the intermediate position between the concave edge portion 26 and the convex edge portion 27 is positioned at the center P in the width direction of the shear surface 31.

展開した状態における小刃２１の平面視形状を直線状として、せん断面３１の一側縁に他の切刃部位より小さな角度α１の切刃３５を形成する。 A cutting edge 35 having a smaller angle α1 than that of the other cutting edge portions is formed on one side edge of the shear surface 31 by making the planar view shape of the small blade 21 in the developed state linear.

本発明では、せん断面３１と非せん断面３２と左右の湾曲面３３・３４とで小刃２１を構成した。また、両湾曲面３３・３４の抉り深さＭ・Ｎを異ならせて、小刃２１の断面を左右で非対称のベルマウス状に形成することにより、せん断面３１の一側縁に他の切刃部位より小さな角度α１の切刃３５を形成するようにした。つまり、せん断面３１の一方の側縁における切刃３５の角度α１を小さくして、その切れ味を向上しながら、せん断面３１の他方の側縁に臨む湾曲面３４の抉り深さＮを小さくして、小刃２１の断面積が小さくなるのを避けるようにした。 In the present invention, the small blade 21 is constituted by the shear surface 31, the non-shear surface 32, and the left and right curved surfaces 33 and 34. Further, by making the bending depths M and N of the curved surfaces 33 and 34 different so that the cross-section of the small blade 21 is formed in an asymmetric bell mouth shape on the left and right, another cutting edge is formed on one side edge of the shear surface 31. A cutting blade 35 having an angle α1 smaller than the blade portion was formed. That is, the angle α1 of the cutting edge 35 at one side edge of the shearing surface 31 is reduced to improve the sharpness, and the depth N of the curved surface 34 facing the other side edge of the shearing surface 31 is reduced. Thus, the cross-sectional area of the small blade 21 is prevented from becoming small.

したがって、本発明の内刃１２によれば、シャープな切れ味を発揮できる切刃３５を形成しながら、小刃２１の構造強度を充分に確保できる。これにより、切刃３５の切れ味の向上と、小刃２１の構造強度の向上との、相反する要求を同時に実現できる。また、せん断面３１の幅寸法を大きくすることもなく小刃２１の構造強度を向上するので、小刃２１の外刃１０に対する摺動抵抗が大きくなるのを回避でき、しかも、ひげの捕捉機会を増加して切断能率を向上できる。また、小刃２１の断面をベルマウス状とするので、刃穴２２から飛び出ようとする毛屑を、下すぼまり状の両湾曲面３３・３４で受け止めて、内刃１２の内面側へ跳ね返し、あるいは落下案内でき、切断後の毛屑がかみそりヘッド３の外面へ飛び出るのをさらに確実に防止できる。 Therefore, according to the inner blade 12 of the present invention, the structural strength of the small blade 21 can be sufficiently ensured while forming the cutting blade 35 that can exhibit a sharp sharpness. Thereby, the contradicting request | requirement of the improvement of the sharpness of the cutting blade 35 and the improvement of the structural strength of the small blade 21 is realizable simultaneously. Further, since the structural strength of the small blade 21 is improved without increasing the width dimension of the shearing surface 31, it is possible to avoid an increase in sliding resistance of the small blade 21 with respect to the outer blade 10 and to capture the beard. Can improve cutting efficiency. Further, since the cross-section of the small blade 21 has a bell mouth shape, the fluff that is about to jump out of the blade hole 22 is received by the both lower curved surfaces 33 and 34 and bounces back to the inner surface side of the inner blade 12. Alternatively, it is possible to guide the fall and further reliably prevent the cut hair from jumping to the outer surface of the razor head 3.

小刃２１の平面視形状を、凹縁部２６と凸縁部２７とで屈曲形状に形成する内刃１２によれば、せん断面３１の左右両側のそれぞれに凹縁部２６と凸縁部２７を設けて、各凹縁部２６における切刃３５の角度α１を他の切刃部位より小さくできる。したがって、内刃１２が往復するときの往動時と復動時のいずれの場合にも、切刃角度α１が小さく切れ味のよい切刃３５でひげを切断して、ひげの切断能率を向上できる。 According to the inner blade 12 in which the shape of the small blade 21 in a plan view is formed by the concave edge portion 26 and the convex edge portion 27, the concave edge portion 26 and the convex edge portion 27 are respectively formed on the left and right sides of the shear surface 31. The angle α1 of the cutting edge 35 at each concave edge portion 26 can be made smaller than other cutting edge portions. Therefore, in both cases of the forward movement and the backward movement when the inner blade 12 reciprocates, the beard is cut with the cutting edge 35 having a small cutting edge angle α1 and good sharpness, so that the cutting efficiency of the whiskers can be improved. .

小刃２１の長手方向に隣接する凹縁部２６と凸縁部２７の間で、小刃２１の断面形状を連続して滑らかに変化させると、隣接する凹縁部２６から凸縁部２７に至る切刃３５の切れ味の変化を緩やかなものとして、切刃３５によるひげ切断を円滑に行なえる。なお、凸縁部２７における切刃３５の切れ味は悪いわけではなく、従来の内刃と同等程度の切れ味を発揮できるので、凹縁部２６に臨む切刃３５の切れ味が他の切刃部位に比べて優れている分だけ、切刃３５によるひげ切断を円滑に行なえることとなる。また、小刃２１の断面形状を凹縁部２６および凸縁部２７の間で連続して滑らかに変化させると、内刃ブランク１１をプレス加工で逆Ｕ字状に折り曲げるときに、曲げ応力が大きく作用するＵ字頂部の曲げ変形を円滑に行なって、内刃１２の曲げ加工を的確に行なうことができる。 When the cross-sectional shape of the small blade 21 is continuously and smoothly changed between the concave edge portion 26 and the convex edge portion 27 adjacent to each other in the longitudinal direction of the small blade 21, the adjacent concave edge portion 26 changes to the convex edge portion 27. The change in sharpness of the cutting blade 35 that reaches is made gentle, and the beard cutting by the cutting blade 35 can be performed smoothly. In addition, the sharpness of the cutting edge 35 in the convex edge portion 27 is not bad, and the same sharpness as that of the conventional inner blade can be exhibited, so that the cutting edge of the cutting edge 35 facing the concave edge portion 26 is in other cutting edge portions. As long as it is superior, the beard cutting by the cutting blade 35 can be performed smoothly. Further, when the cross-sectional shape of the small blade 21 is continuously and smoothly changed between the concave edge portion 26 and the convex edge portion 27, bending stress is generated when the inner blade blank 11 is bent into an inverted U shape by press working. Bending deformation of the U-shaped top portion which acts greatly can be performed smoothly, and the inner blade 12 can be bent accurately.

小刃２１の長手方向に隣接する凹縁部２６および凸縁部２７において、凹縁部２６の小刃２１の断面形状と、凸縁部２７の小刃２１の断面形状とを線対称に形成すると、内刃１２が往復するときの往動時の切刃３５の切断状況と、復動時の切刃３５の切断状況とを均等なものにして、ひげをさらに効果的に切断できる。 In the concave edge portion 26 and the convex edge portion 27 adjacent to the longitudinal direction of the small blade 21, the cross-sectional shape of the small blade 21 of the concave edge portion 26 and the cross-sectional shape of the small blade 21 of the convex edge portion 27 are formed in line symmetry. Then, the cutting state of the cutting blade 35 during the forward movement when the inner blade 12 reciprocates and the cutting state of the cutting blade 35 during the backward movement can be made equal, and the whiskers can be cut more effectively.

基端部２８の断面積Ｓ３を小刃２１の他の部位における断面積より大きく設定すると、基端部２８の強度を向上して小刃２１の構造強度を大きくできる。したがって、ひげ切断時の負荷が急激に変化して、小刃２１に大きな切断モーメントが作用するような場合であっても、小刃２１を適正な切断姿勢に維持して、ひげ切断を効果的に行なえる。 If the cross-sectional area S3 of the base end portion 28 is set to be larger than the cross-sectional areas at other portions of the small blade 21, the strength of the base end portion 28 can be improved and the structural strength of the small blade 21 can be increased. Therefore, even when the load at the time of cutting the beard changes suddenly and a large cutting moment acts on the cutting blade 21, the cutting blade 21 is maintained in an appropriate cutting posture and the cutting of the beard is effective. It can be done.

小刃２１の基端部２８を、装着壁２０・２０から内刃１２の往復駆動方向と略直交する向きに直線状に連出すると、断面積が大きな基端部２８の前後長さを大きくして、小刃２１の構造強度をさらに増強できる。また、基端部２８と装着壁２０との左右の隣接隅部が危険断面部になるのを避けて、先の隣接隅部に亀裂が発生するのを防止し、その分、小刃２１の構造強度を向上できる。しかも、ひげ切断に殆ど寄与することのない基端部２８の強度を向上して小刃２１の構造強度を向上できるので、小刃構造に無駄がなく、さらにエッチング処理時に増強された基端部２８を同時に形成できる点でコストの無駄を省くことができる。 When the proximal end portion 28 of the small blade 21 is linearly extended from the mounting walls 20 and 20 in a direction substantially orthogonal to the reciprocating drive direction of the inner blade 12, the longitudinal length of the proximal end portion 28 having a large cross-sectional area is increased. Thus, the structural strength of the blade 21 can be further increased. Further, the right and left adjacent corners of the base end portion 28 and the mounting wall 20 are prevented from becoming dangerous cross-sections, and the occurrence of cracks in the previous adjacent corners is prevented. The structural strength can be improved. Moreover, since the strength of the base end portion 28 that hardly contributes to cutting the whiskers can be improved and the structural strength of the small blade 21 can be improved, there is no waste in the structure of the small blade, and the base end portion enhanced during the etching process. Cost can be saved in that 28 can be formed simultaneously.

小刃２１の平面視形状を波形に形成すると、湾曲する凹縁部２６の形が湾曲する凸縁部２７の形に変化するときの、形状の変化を緩やかなものとして、切刃角度α１の小さな切刃３５が形成される領域を、凹縁部２６に沿って広い範囲に拡大できる。したがって、凹縁部２６に臨む状態で捕捉されたひげを、切刃角度が小さく、切れ味のよい凹縁部２６付近の切刃３５で的確に、しかも速やかに切断できる。 When the planar view shape of the small blade 21 is formed into a waveform, the shape change when the shape of the curved concave edge portion 26 changes to the curved convex edge portion 27 is regarded as a gradual change in the cutting blade angle α1. The region where the small cutting edge 35 is formed can be expanded in a wide range along the concave edge portion 26. Therefore, the whisker captured while facing the concave edge portion 26 can be accurately and quickly cut with the cutting blade 35 near the concave edge portion 26 having a small cutting edge angle and good sharpness.

基端部２８を除く非せん断面３２の小刃幅Ｂ１・Ｂ２を略一定とし、凹縁部２６および凸縁部２７における非せん断面３２をせん断面３１の幅方向中心Ｐから左右方向へ交互に偏寄させ、さらに両縁部２６・２７の中間位置の非せん断面３２をせん断面３１の幅方向中心Ｐに位置させると、小刃２１の長手方向の強度を概ね一定にできる。したがって、内刃ブランク１１をプレス加工で逆Ｕ字状に折り曲げるときに、曲げ応力が大きく作用するＵ字頂部の曲げ変形を円滑に行なって、曲げ形状を所定の湾曲形状に形成でき、内刃１２の曲げ加工を適確に行なうことができる。因みに、小刃２１の長手方向の強度にばらつきがある場合には、Ｕ字頂部の曲げ形状がばらつくおそれがある。 The small blade widths B1 and B2 of the non-shear surface 32 excluding the base end portion 28 are made substantially constant, and the non-shear surfaces 32 at the concave edge portion 26 and the convex edge portion 27 alternate from the width direction center P of the shear surface 31 in the left-right direction. If the non-shear surface 32 at the intermediate position between the edges 26 and 27 is positioned at the center P in the width direction of the shear surface 31, the strength in the longitudinal direction of the blade 21 can be made substantially constant. Therefore, when the inner blade blank 11 is bent into an inverted U shape by press working, the U-shaped top portion where the bending stress acts greatly can be bent and deformed smoothly, and the bent shape can be formed into a predetermined curved shape. 12 bending processes can be performed accurately. Incidentally, when the strength of the blade 21 in the longitudinal direction varies, the bent shape of the U-shaped top portion may vary.

小刃２１の平面視形状を直線状として、せん断面３１の一側縁に他の切刃部位より小さな角度α１の切刃３５を形成すると、切刃角度α１が小さな切刃３５を小刃２１の前後方向に沿って連続する状態で形成できる。したがって、内刃１２の往動時、あるいは復動時の少なくともいずれかにおいて、切れ味のシャープな切刃３５でひげを一斉に切断して、内刃１２の全体の切れ味を向上できる。 When the cutting blade 35 having a smaller angle α1 than the other cutting blade portions is formed on one side edge of the shearing surface 31 with the planar view shape of the small blade 21 being a straight line, the cutting blade 35 having a small cutting blade angle α1 is formed into the small blade 21. Can be formed in a continuous state along the front-rear direction. Therefore, at least one of the forward movement and the backward movement of the inner blade 12 can cut the whiskers all at once with the sharp cutting blade 35 to improve the overall sharpness of the inner blade 12.

内刃ブランクを非せん断面の側から見るときの平面図である。It is a top view when an inner blade blank is seen from the non-shear surface side. 電気かみそりの正面図である。It is a front view of an electric razor. かみそりヘッドの縦断側面図である。It is a vertical side view of a razor head. （ａ）から（ｄ）は、エッチング法による小刃の形成過程を示す断面図である。(A)-(d) is sectional drawing which shows the formation process of the small blade by an etching method. 図１における小刃の断面形状を示す断面図であり、（ａ）は図１のＡ−Ａ線断面図、（ｂ）は図１のＢ−Ｂ線断面図、（ｃ）は図１のＣ−Ｃ線断面図、（ｄ）は図１のＤ−Ｄ線断面図を示す。It is sectional drawing which shows the cross-sectional shape of the small blade in FIG. 1, (a) is the sectional view on the AA line of FIG. 1, (b) is the sectional view on the BB line of FIG. 1, (c) is FIG. CC sectional drawing, (d) shows the DD sectional view taken on the line of FIG. 内刃を分解した斜視図である。It is the perspective view which decomposed | disassembled the inner blade. 小刃の形成パターンを変更した図１と同等の平面図である。It is the top view equivalent to FIG. 1 which changed the formation pattern of the small blade. 図７における小刃の断面形状を示す断面図であり、（ａ）は図７のＥ−Ｅ線断面図、（ｂ）は図７のＦ−Ｆ線断面図、（ｃ）は図７のＧ−Ｇ線断面図、（ｄ）は図７のＨ−Ｈ線断面図を示す。It is sectional drawing which shows the cross-sectional shape of the small blade in FIG. 7, (a) is the EE sectional view taken on the line of FIG. 7, (b) is the FF sectional view taken on the line of FIG. 7, (c) is FIG. GG sectional drawing, (d) shows the HH sectional view of FIG. 小刃の形成パターンを変更した図１と同等の平面図である。It is the top view equivalent to FIG. 1 which changed the formation pattern of the small blade. 内刃の別の実施例を示す平面図である。It is a top view which shows another Example of an inner blade. 図１０における小刃の断面形状を示す断面図であり、（ａ）は図１０のＪ−Ｊ線断面図、（ｂ）は図１０のＫ−Ｋ線断面図を示す。It is sectional drawing which shows the cross-sectional shape of the small blade in FIG. 10, (a) is the JJ sectional view taken on the line of FIG. 10, (b) shows the KK sectional view of FIG. 図１０における小刃の断面形状の別の実施例を示す断面図である。It is sectional drawing which shows another Example of the cross-sectional shape of the small blade in FIG.

図１ないし図６は本発明に係るレシプロ式の電気かみそりの実施例を示す。図２において電気かみそりは、本体ケース１と、本体ケース１に組み付けられる作動ユニットとを備えている。本体ケース１の前面にはモーター起動用のスイッチボタン２が設けてあり、背面上部にはきわ剃り刃ユニット（図示していない）が設けてある。作動ユニットは、下半側の電装品ユニットと、電装品ユニットの上部に設けられるかみそりヘッド３とで構成する。電装品ユニットは、回路基板と２次電池４などで構成してある。回路基板には、先のスイッチボタン２でオンオフされるスイッチユニットや、制御回路を構成する電子部品、および表示部用のＬＥＤなどが実装してある。 1 to 6 show an embodiment of a reciprocating electric shaver according to the present invention. In FIG. 2, the electric razor includes a main body case 1 and an operation unit assembled to the main body case 1. A switch button 2 for starting the motor is provided on the front surface of the main body case 1, and a shaving blade unit (not shown) is provided on the upper back surface. The operation unit is composed of an electrical component unit on the lower half side and a razor head 3 provided on the upper portion of the electrical component unit. The electrical component unit includes a circuit board and a secondary battery 4. On the circuit board, a switch unit that is turned on / off by the previous switch button 2, electronic components that constitute a control circuit, LEDs for a display unit, and the like are mounted.

かみそりヘッド３は、ヘッドフレーム５と、その下部に固定されるモーター６と、かみそりヘッド３の上部に配置される切断部と、モーター６の動力を切断部に伝動する駆動構造と、ヘッドフレーム５に対して着脱される外刃ホルダー７などで構成してある。かみそりヘッド３は、本体ケース１で上下フロート可能に、しかも前後傾動、および左右傾動可能に支持してある。本体ケース１に収容されるモーター６および回路基板を含む電装品ユニットは、かみそりヘッド３と本体ケース１との間に設けた成形パッキンでシールしてある。 The razor head 3 includes a head frame 5, a motor 6 fixed to the lower portion of the razor head, a cutting portion disposed on the upper portion of the razor head 3, a drive structure for transmitting the power of the motor 6 to the cutting portion, and the head frame 5. It is comprised with the outer blade holder 7 etc. which can be attached or detached with respect to. The razor head 3 is supported by the main body case 1 so that it can float up and down, and can be tilted back and forth and tilted left and right. The electrical component unit including the motor 6 and the circuit board accommodated in the main body case 1 is sealed with a molding packing provided between the razor head 3 and the main body case 1.

切断部は、左右横長の外刃１０と、外刃１０の内面に沿って左右に往復駆動される左右横長の内刃１２とからなる。外刃１０は電鋳法あるいはエッチング法で形成されるシート状の網刃からなり、先の外刃ホルダー７で逆Ｕ字状に保形してある。内刃１２は、図４に想像線で示す内刃ブランク１１にプレス加工を施して、逆Ｕ字状に折り曲げたスリット刃からなり、内刃ホルダー１３に固定されて逆Ｕ字状に保形してある。後述するように、内刃ブランク１１はエッチング法で形成する。 The cutting part includes a laterally long outer blade 10 and a laterally long inner blade 12 that is driven to reciprocate left and right along the inner surface of the outer blade 10. The outer blade 10 is a sheet-like mesh blade formed by electroforming or etching, and is held in an inverted U shape by the outer blade holder 7. The inner blade 12 is composed of a slit blade that is press-processed on the inner blade blank 11 indicated by an imaginary line in FIG. 4 and bent into an inverted U shape, and is fixed to the inner blade holder 13 and retained in an inverted U shape. It is. As will be described later, the inner blade blank 11 is formed by an etching method.

内刃１２を往復駆動する駆動構造は、モーター６の出力軸に固定される偏心カム１５と、振動子１６と、振動子１６の上部中央に突設される駆動軸１７とで構成してある。モーター６の回転動力は、偏心カム１５と振動子１６とで往復動力に変換され、駆動軸１７を介して内刃１２に伝動される。往復動力はきわ剃り刃ユニットにも伝動される。内刃１２は、振動子１６と内刃ホルダー１３との間に配置した圧縮コイル形のばね１８で押し上げ付勢されて、外刃１０の内面に常に密着している。内刃ホルダー１３には、駆動軸１７と係合する受動片１９が設けてある。 The drive structure for reciprocating the inner blade 12 includes an eccentric cam 15 fixed to the output shaft of the motor 6, a vibrator 16, and a drive shaft 17 projecting from the upper center of the vibrator 16. . The rotational power of the motor 6 is converted into reciprocating power by the eccentric cam 15 and the vibrator 16 and transmitted to the inner blade 12 through the drive shaft 17. The reciprocating power is also transmitted to the sharp shaving blade unit. The inner blade 12 is pushed up and biased by a compression coil spring 18 disposed between the vibrator 16 and the inner blade holder 13, and is always in close contact with the inner surface of the outer blade 10. The inner blade holder 13 is provided with a passive piece 19 that engages with the drive shaft 17.

図１に示すように、先の内刃ブランク１１は左右横長のシート体からなり、シート体の面壁の前後辺部に沿って、内刃ホルダー１３に装着される装着壁２０を有し、両装着壁２０・２０を繋ぐ前後方向に長いリブ状の小刃２１と、隣接する小刃２１の間に形成される刃穴２２とを左右方向へ交互に設けて構成してある。シート体の長辺部の左右（四隅）には、それぞれ内刃ホルダー１３の突起２３に係合する切欠２４がコ字状に形成され、各切欠２４の左右に丸穴からなる固定穴２５が形成してある。内刃１２における前後、左右、上下とは、図６に示す交差矢印と、前後、左右、上下の文字表記に従うこととする。 As shown in FIG. 1, the inner blade blank 11 is formed of a horizontally long sheet body, and has a mounting wall 20 to be mounted on the inner blade holder 13 along the front and rear sides of the surface wall of the sheet body. Ribbed small blades 21 that are long in the front-rear direction connecting the mounting walls 20 and 20 and blade holes 22 formed between adjacent small blades 21 are alternately provided in the left-right direction. Cutouts 24 that engage with the projections 23 of the inner blade holder 13 are formed in the left and right sides (four corners) of the long side portion of the sheet body, respectively, and fixing holes 25 that are round holes are formed on the left and right of each cutout 24. It is formed. The front / rear, left / right, and upper / lower directions of the inner blade 12 follow the crossing arrows shown in FIG.

図１に示すように小刃２１の平面視形状は、内凹み湾曲状の凹縁部２６と外凸湾曲状の凸縁部２７とが交互に連続する波形の屈曲形状に形成されており、その前後端の基端部２８は、それぞれ装着壁２０から内刃１２の往復駆動方向と略直交する向きに直線状に連出してある。小刃２１の両側における凹縁部２６と凸縁部２７とは相似の関係にある。凹縁部２６および凸縁部２７の湾曲方向は、両者２６・２７の湾曲中央部分で逆向きに変わるが、この湾曲方向が逆向きに変わる分を変曲部分という。 As shown in FIG. 1, the planar view shape of the blade 21 is formed into a wave-like bent shape in which inner concave curved concave edges 26 and outer convex curved convex edges 27 are alternately arranged. The base end portions 28 at the front and rear ends thereof are linearly extended from the mounting wall 20 in a direction substantially orthogonal to the reciprocating drive direction of the inner blade 12. The concave edge portion 26 and the convex edge portion 27 on both sides of the small blade 21 are in a similar relationship. The bending directions of the concave edge portion 26 and the convex edge portion 27 change in the opposite directions at the central portions of the curves 26 and 27. The amount of the change in the bending direction is referred to as an inflection portion.

小刃２１の基本的な断面形状は、互いに平行な外面のせん断面３１、および内面の非せん断面３２と、これら両者３１・３２の左右側縁間の肉壁を抉る内凹み状の左右の湾曲面３３・３４とでベルマウス状に形成する。せん断面３１の左右両側縁のそれぞれには、せん断面３１と湾曲面３３・３４に挟まれる鋭角の切刃３５が形成され、これらの切刃３５が外刃１０と協同してひげを切断する。また、非せん断面３２の左右両側縁のそれぞれには、先の切刃３５より角度は大きいが同様に鋭角の隅部３６が形成してある。 The basic cross-sectional shape of the blade 21 is that the outer shearing surface 31 and the inner non-shearing surface 32 parallel to each other, and the left and right inner dents that sandwich the wall between the left and right edges of both 31 and 32. The curved surfaces 33 and 34 are formed into a bell mouth shape. A sharp cutting edge 35 sandwiched between the shearing surface 31 and the curved surfaces 33 and 34 is formed on each of the left and right edges of the shearing surface 31, and these cutting blades 35 cut the beard in cooperation with the outer blade 10. . Further, on both the left and right side edges of the non-shear surface 32, an acute corner 36 is formed in the same manner, although the angle is larger than that of the previous cutting edge 35.

内刃ブランク１１は、厚みが０．２５ｍｍのステンレス板材に、エッチング処理を施して形成するが、その過程で小刃２１を構成する各面壁３１〜３４が形成される。図４に示すようにエッチング処理では、ステンレス板材の表裏両面にそれぞれレジスト膜３８・３９を形成したのち露光し、露光部分を除去してレジスト膜に囲まれる板材表面をエッチング液で蝕刻する。図４（ａ）から図４（ｄ）の各図は、図５（ａ）から図５（ｄ）に示す小刃２１の断面を形成するためのレジスト膜３８・３９の形成パターンを示している。 The inner blade blank 11 is formed by subjecting a stainless steel plate having a thickness of 0.25 mm to an etching process. In the process, the face walls 31 to 34 constituting the small blade 21 are formed. As shown in FIG. 4, in the etching process, resist films 38 and 39 are respectively formed on both the front and back surfaces of a stainless steel plate material, and then exposed. The exposed portion is removed and the surface of the plate material surrounded by the resist film is etched with an etching solution. 4A to 4D show the formation patterns of the resist films 38 and 39 for forming the cross section of the blade 21 shown in FIGS. 5A to 5D. Yes.

いずれの場合にも、裏側（非せん断面３２側）のレジスト膜のパターンは、表側（せん断面３１側）のレジストパターンに比べてひとまわり小さく形成してあり、裏側のレジスト膜に囲まれる板材の表面積は表側のそれに比べて大きい。そのため、ステンレス板材の表面に比べて裏面側の蝕刻の度合が大きくなる。蝕刻によってせん断面３１側から成長した湾曲面と、非せん断面３２側から成長した湾曲面とは、最終的にひとつの湾曲面になって湾曲面３３・３４を形成するが、裏面側の蝕刻の度合が大きい分だけ、裏面側へ向かって先すぼまり状となり、これにより小刃２１の基本的な断面形状がベルマウス状となる。 In any case, the pattern of the resist film on the back side (non-shear surface 32 side) is formed slightly smaller than the resist pattern on the front side (shear surface 31 side), and is a plate material surrounded by the resist film on the back side The surface area of is larger than that of the front side. Therefore, the degree of etching on the back surface side becomes larger than the surface of the stainless steel plate. The curved surface grown from the shearing surface 31 side by the etching and the curved surface grown from the non-shearing surface 32 side eventually become one curved surface to form the curved surfaces 33 and 34. As the degree of is increased, the shape is tapered toward the back surface side, and the basic cross-sectional shape of the blade 21 becomes a bell mouth shape.

裏側のレジストパターンは、表側のレジストパターンに対して、凸縁部２７の側では凸縁部２７と相似に形成するが、凹縁部２６においては、凹縁部２６より湾曲半径が小さくなるように形成する。そのため、凹縁部２６の側の蝕刻の度合は、凸縁部２７の側の蝕刻の度合に比べて大きくなる。この蝕刻作用の違いによって、凹縁部２６側の湾曲面３３は、凸縁部２７側の湾曲面３４に比べてより大きく抉られる。また、凹縁部２６における切刃３５の角度α１は、凸縁部２７における切刃３５の角度α２より小さくなり、したがって、凹縁部２６における切刃３５の切れ味は、他の切刃部位に比べて鋭くなる。 The resist pattern on the back side is formed to be similar to the convex edge portion 27 on the side of the convex edge portion 27 with respect to the resist pattern on the front side. However, the radius of curvature of the concave edge portion 26 is smaller than that of the concave edge portion 26. To form. Therefore, the degree of etching on the concave edge portion 26 side is larger than the degree of etching on the convex edge portion 27 side. Due to the difference in the etching action, the curved surface 33 on the concave edge portion 26 side is sharpened more greatly than the curved surface 34 on the convex edge portion 27 side. In addition, the angle α1 of the cutting edge 35 in the concave edge portion 26 is smaller than the angle α2 of the cutting edge 35 in the convex edge portion 27. Therefore, the sharpness of the cutting edge 35 in the concave edge portion 26 is different from other cutting edge portions. It becomes sharper than that.

凹縁部２６と凸縁部２７の中間位置における左右の切刃３５の角度α３は同じであり、基端部２８における左右の切刃３５の角度α４も同じである。エッチングが完了した時点における、せん断面３１および非せん断面３２の幅は、図４に想像線で示すようにレジストパターンの幅より小さくなる。なお、蝕刻作用で形成される湾曲面３３・３４は、図１に示すように刃穴端部においては、半円状の刃穴２２の端部で消滅する。切欠２４および固定穴２５は、エッチング法で小刃２１を形成する過程で同時に形成してあり、固定穴２５の内面は球面状となる。 The angle α3 of the left and right cutting edges 35 at the intermediate position between the concave edge portion 26 and the convex edge portion 27 is the same, and the angle α4 of the left and right cutting edges 35 at the base end portion 28 is also the same. When the etching is completed, the widths of the shearing surface 31 and the non-shearing surface 32 are smaller than the width of the resist pattern as indicated by an imaginary line in FIG. The curved surfaces 33 and 34 formed by the etching action disappear at the end of the semicircular blade hole 22 at the edge of the blade hole as shown in FIG. The notch 24 and the fixing hole 25 are formed simultaneously in the process of forming the small blade 21 by the etching method, and the inner surface of the fixing hole 25 is spherical.

エッチング処理を経て得られた内刃ブランク１１における小刃２１の断面形状を図５に示している。なお、図５（ａ）から図５（ｄ）の各図は、図１におけるＡ−Ａ線、Ｂ−Ｂ線、Ｃ−Ｃ線、Ｄ−Ｄ線での断面を示している。図５において、
Ｗは、せん断面３１の小刃幅であり、小刃２１の全幅でもある。
Ｂ１は、凹縁部２６および凸縁部２７における非せん断面３２の小刃幅である。
Ｂ２は、凹縁部２６と凸縁部２７の中間位置における非せん断面３２の小刃幅である。
Ｂ３は、基端部２８における非せん断面３２の小刃幅である。
α１は、凹縁部２６における切刃３５の角度であり、この実施例では２７度とした。
α２は、凸縁部２７における切刃３５の角度であり、この実施例では５０度とした。
α３は、凹縁部２６と凸縁部２７の中間部における切刃３５の角度であり、この実施例では４５度とした。
α４は、基端部２８における切刃３５の角度であり、この実施例では６０度とした。
Ｓ１は、凹縁部２６あるいは凸縁部２７における小刃２１の断面積である。
Ｓ２は、凹縁部２６と凸縁部２７の中間位置における小刃２１の断面積である。
Ｓ３は、基端部２８ににおける小刃２１の断面積である。 The cross-sectional shape of the small blade 21 in the inner blade blank 11 obtained through the etching process is shown in FIG. In addition, each figure of Fig.5 (a) to FIG.5 (d) has shown the cross section in the AA line, BB line, CC line, and DD line in FIG. In FIG.
W is the width of the small blade of the shear surface 31 and is also the full width of the small blade 21.
B 1 is the small blade width of the non-shear surface 32 at the concave edge portion 26 and the convex edge portion 27.
B 2 is the small blade width of the non-shear surface 32 at an intermediate position between the concave edge portion 26 and the convex edge portion 27.
B3 is the small blade width of the non-shear surface 32 at the base end portion 28.
α1 is an angle of the cutting edge 35 in the concave edge portion 26, and in this embodiment, it is 27 degrees.
α2 is the angle of the cutting edge 35 in the convex edge portion 27, and in this embodiment, it is 50 degrees.
α3 is an angle of the cutting edge 35 at the intermediate portion between the concave edge portion 26 and the convex edge portion 27, and is set to 45 degrees in this embodiment.
α4 is an angle of the cutting edge 35 at the base end portion 28, and in this embodiment, it is set to 60 degrees.
S 1 is a cross-sectional area of the small blade 21 at the concave edge portion 26 or the convex edge portion 27.
S 2 is a cross-sectional area of the blade 21 at an intermediate position between the concave edge portion 26 and the convex edge portion 27.
S3 is a cross-sectional area of the small blade 21 at the base end portion 28.

この実施例における上記の各部の寸法、角度、および断面積の関係は以下通りとなる。
（Ｗ＞Ｂ３＞Ｂ２＞Ｂ１）
（α４＞α２＞α３＞α１）
（Ｓ３＞Ｓ２＞Ｓ１） The relationship among the dimensions, angles, and cross-sectional areas of the respective parts in this embodiment is as follows.
(W>B3>B2> B1)
(Α4>α2>α3> α1)
(S3>S2> S1)

せん断面３１の幅Ｗは、一方の基端部２８から他方の基端部２８にわたって一定である。非せん断面３２の幅は、凹縁部２６および凸縁部２７が形成してある位置と、隣接する凹縁部２６と凸縁部２７との中間位置との間で連続して滑らかに変化させてある。凹縁部２６と凸縁部２７が形成してある位置における非せん断面３２の幅は小さく、凹縁部２６と凸縁部２７との間の中間位置における非せん断面３２の幅は大きく、基端部２８における非せん断面３２の幅は最大になっている（Ｂ３＞Ｂ２＞Ｂ１）。 The width W of the shear surface 31 is constant from one base end portion 28 to the other base end portion 28. The width of the non-shear surface 32 continuously and smoothly changes between a position where the concave edge portion 26 and the convex edge portion 27 are formed and an intermediate position between the adjacent concave edge portion 26 and the convex edge portion 27. I'm allowed. The width of the non-shear surface 32 at the position where the concave edge portion 26 and the convex edge portion 27 are formed is small, and the width of the non-shear surface 32 at the intermediate position between the concave edge portion 26 and the convex edge portion 27 is large, The width of the non-shear surface 32 at the base end portion 28 is maximized (B3> B2> B1).

凹縁部２６および凸縁部２７における非せん断面３２は、せん断面３１の幅方向中心Ｐから左右いずれかへ偏寄させてあり、これにより左右の湾曲面３３・３４の抉り深さＭ・Ｎが異ならせてある。このように、抉り深さＭ・Ｎを大小に異ならせると、各湾曲面３３・３４の湾曲度合に差が生じ、せん断面に３１における切刃３５の角度α１・α２を大小に異ならせることができる。これに伴ない湾曲面３３・３４の形状は左右で非対称となって、小刃２１の断面を左右で非対称のベルマウス形状とすることができる。 The non-shear surface 32 in the concave edge portion 26 and the convex edge portion 27 is offset to the left or right from the center P in the width direction of the shear surface 31, and thereby the depth M · of the curved surfaces 33 and 34 on the left and right sides. N is different. As described above, when the depths M and N are varied in size, a difference in the degree of curvature of the curved surfaces 33 and 34 occurs, and the angles α1 and α2 of the cutting edge 35 at the shear surface 31 are varied in size. Can do. Accordingly, the shapes of the curved surfaces 33 and 34 are asymmetrical on the left and right, and the cross section of the small blade 21 can be asymmetrical bell mouth shape on the left and right.

詳しくは、図５（ａ）に示すように、非せん断面３２の幅方向中央位置が、せん断面３１の幅方向中心Ｐから右側へ偏寄する場合には、図５（ａ）に向かって左側の湾曲面３３の抉り深さＭが、右側の湾曲面３４の抉り深さＮより大きくなる。これに伴ない、左側の凹縁部２６における切刃３５の角度α１が、右側の凸縁部２７における切刃３５の角度α２より小さくなる。また、図５（ｃ）に示すように、非せん断面３２の幅方向中央位置が、せん断面３１の幅方向中心Ｐから左側へ偏寄する場合には、図５（ｃ）に向かって右側の湾曲面３４の抉り深さＮが、左側の湾曲面３３の抉り深さＭより大きくなる。さらに、右側の凹縁部２６における切刃３５の角度α１が、凸縁部２７における切刃３５の角度α２より小さくなる。図５（ａ）の小刃２１の断面形状と、図５（ｃ）の小刃２１の断面形状とは線対称の関係にあり、切刃３５の角度α１・α２は同じ値となる。 Specifically, as shown in FIG. 5A, when the center position in the width direction of the non-shear surface 32 is shifted to the right side from the center P in the width direction of the shear surface 31, the direction is toward FIG. The depth M of the curved surface 33 on the left side is larger than the depth N of the curved surface 34 on the right side. Accordingly, the angle α1 of the cutting edge 35 in the left concave edge portion 26 becomes smaller than the angle α2 of the cutting edge 35 in the right convex edge portion 27. Further, as shown in FIG. 5C, when the center position in the width direction of the non-shear surface 32 deviates from the width direction center P of the shear surface 31 to the left side, the right side toward FIG. The bending depth N of the curved surface 34 is greater than the bending depth M of the left curved surface 33. Furthermore, the angle α1 of the cutting edge 35 in the right concave edge portion 26 is smaller than the angle α2 of the cutting edge 35 in the convex edge portion 27. The cross-sectional shape of the blade 21 in FIG. 5A and the cross-sectional shape of the blade 21 in FIG. 5C are axisymmetric, and the angles α1 and α2 of the cutting blade 35 have the same value.

凹縁部２６と凸縁部２７との中間位置においては、図５（ｂ）に示すように、非せん断面３２の幅方向中央が、せん断面３１の幅方向中心に位置している。その場合には、左右の湾曲面３３・３４の抉り深さを等しくして、せん断面３１に形成される切刃３５の角度α３を左右で等しくできる。この場合の切刃３５の角度α３は、角度α１と角度α２の中間の角度となる。また、図５（ｄ）に示すように、基端部２８における非せん断面３２の幅寸法を、他の部位より大きくすることにより、湾曲面３３・３４の抉り深さを最小として、基端部２８における切刃３５の角度α４を最大とすることができる。 At the intermediate position between the concave edge portion 26 and the convex edge portion 27, the center in the width direction of the non-shear surface 32 is positioned at the center in the width direction of the shear surface 31 as shown in FIG. In that case, the angle α3 of the cutting edge 35 formed on the shearing surface 31 can be made equal on the left and right by making the depths of the left and right curved surfaces 33 and 34 equal. In this case, the angle α3 of the cutting edge 35 is an intermediate angle between the angles α1 and α2. Further, as shown in FIG. 5 (d), by making the width dimension of the non-shear surface 32 in the base end portion 28 larger than that of other portions, the depth of the curved surfaces 33 and 34 is minimized, and the base end The angle α4 of the cutting edge 35 in the portion 28 can be maximized.

小刃２１の断面形状は、隣接する凹縁部２６と凸縁部２７との間で連続して滑らかに変化しており、切刃角度α１〜α３も同様に連続して滑らかに変化している。なお、本発明における小刃２１とは、外刃１０と摺接してひげ切断を行なう部分はもちろん、ひげ切断に寄与しない部分をも含むリブ状部分の全体を意味する。また、内刃１２と外刃１０とがごく僅かな隙間を介してひげ切断（せん断）を行なう場合の小刃も、本発明の小刃２１に含むこととする。 The cross-sectional shape of the small blade 21 is continuously and smoothly changed between the adjacent concave edge portion 26 and the convex edge portion 27, and the cutting edge angles α1 to α3 are also continuously and smoothly changed. Yes. In addition, the small blade 21 in this invention means the whole rib-shaped part including the part which does not contribute to beard cutting as well as the part which carries out slidable contact with the outer blade 10, and cuts a beard. The small blade 21 of the present invention also includes a small blade when the inner blade 12 and the outer blade 10 perform beard cutting (shearing) through a very small gap.

図６において、内刃ホルダー１３は、左右一対のトンネル断面状の側壁４０と、これらの側壁４０の前後面を繋ぐホルダー基部４１とで、上下に開口する中空枠状に形成してある。前後のホルダー基部４１には、内刃１２を組み付けるための装着座４２が形成してあり、前後の装着座４２の左右両側に突起２３が膨出形成してある。ホルダー基部４１の前後対向面の間には、３個の補強リブ４３が一体に設けてあり、中央の補強リブ４３の下端に駆動軸１７と係合する受動片１９が設けてある（図３参照）。 In FIG. 6, the inner blade holder 13 is formed in a hollow frame shape that opens up and down with a pair of left and right tunnel cross-sectional side walls 40 and a holder base 41 that connects the front and rear surfaces of these side walls 40. The front and rear holder bases 41 are provided with mounting seats 42 for assembling the inner blade 12, and protrusions 23 are formed on both the left and right sides of the front and rear mounting seats 42. Three reinforcing ribs 43 are integrally provided between the front and rear surfaces of the holder base 41, and a passive piece 19 that engages with the drive shaft 17 is provided at the lower end of the central reinforcing rib 43 (FIG. 3). reference).

プレス加工が施されてＵ字状に折り曲げられた内刃１２は、上記構造の内刃ホルダー１３に対して以下のように組み付ける。まず、内刃１２の全体を内刃ホルダー１３の上方から装着座４２にあてがいながら押し下げて切欠２４を突起２３に係合し、内刃１２を仮固定する。この状態で、丸軸状の加熱治具を固定穴２５から差し込んで、その先端部分を装着座４２の肉壁に押し込む。加熱治具で溶融され、その軸端で押し退けられたプラスチックは、図３に示すように、固定穴２５の内面に入り込んだ状態で固化され、溶着塊４４となる。このように内刃１２の前後四隅を溶着することにより、内刃１２を内刃ホルダー１３に対して分離不能に固定して、内刃ユニットを完成できる。固化した状態の溶着塊４４は固定穴２５を概ね充満するが、固定穴２５から溢れ出ることはない。 The inner blade 12 that has been pressed and bent into a U shape is assembled to the inner blade holder 13 having the above structure as follows. First, the entire inner blade 12 is pushed down from above the inner blade holder 13 against the mounting seat 42 to engage the notch 24 with the projection 23 to temporarily fix the inner blade 12. In this state, a round shaft-shaped heating jig is inserted from the fixing hole 25, and its tip is pushed into the wall of the mounting seat 42. As shown in FIG. 3, the plastic melted by the heating jig and pushed away at the shaft end is solidified in a state of entering the inner surface of the fixing hole 25 to form a welded mass 44. By welding the front and rear four corners of the inner blade 12 in this manner, the inner blade 12 can be fixed to the inner blade holder 13 in an inseparable manner, and the inner blade unit can be completed. The welded mass 44 in the solidified state substantially fills the fixing hole 25, but does not overflow from the fixing hole 25.

以上のように構成した内刃１２によれば、凹縁部２６側の切刃３５の角度α１を小さくしながら、凸縁側２７の湾曲面３４の抉り深さＮを小さくして、小刃２１の断面積を充分なものとするので、切刃３５の切れ味の向上と、小刃２１の構造強度の維持とを同時に実現することができる。また、小刃２１の平面視形状をそれぞれ湾曲する凹縁部２６と凸縁部２７とが交互に連続する波形に形成するので、切刃３５の角度α１が小さな領域を、凹縁部２６に沿って広い範囲に形成することができる。これにより、凹縁部２６に臨む状態で捕捉されたひげを、切刃角度が小さく、切れ味のよい凹縁部２６付近の切刃３５で的確に切断できる。 According to the inner blade 12 configured as described above, the angle N1 of the curved surface 34 on the convex edge side 27 is decreased while the angle α1 of the cutting blade 35 on the concave edge portion 26 side is decreased, and the small blade 21 is formed. Therefore, it is possible to simultaneously improve the sharpness of the cutting blade 35 and maintain the structural strength of the small blade 21. In addition, since the concave edge portions 26 and the convex edge portions 27 that are curved in the plan view shape of the small blade 21 are alternately formed, a region where the angle α1 of the cutting blade 35 is small is formed in the concave edge portion 26. It can be formed in a wide range along. As a result, the whiskers captured while facing the concave edge portion 26 can be accurately cut with the cutting blade 35 near the concave edge portion 26 having a small cutting edge angle and good sharpness.

基端部２８における非せん断面３２の小刃幅Ｂ３を他より大きくし、さらに湾曲面３３・３４の抉り深さを他より小さくするので、基端部２８における小刃２１の断面積Ｓ３を小刃２１の他の部位における断面積より大きくできる。したがって、基端部２８の強度を向上して小刃２１の構造強度を向上できる。 Since the small blade width B3 of the non-shear surface 32 at the base end portion 28 is made larger than the others, and the depth of bending of the curved surfaces 33 and 34 is made smaller than the others, the sectional area S3 of the small blade 21 at the base end portion 28 is It can be larger than the cross-sectional area at the other part of the blade 21. Therefore, the strength of the base end portion 28 can be improved and the structural strength of the blade 21 can be improved.

また、小刃２１の全長にわたる断面形状をベルマウス形状とすることにより、左右の湾曲面３３・３４のそれぞれを、内刃１２の外面へ向かって外広がり状に湾曲させることができる。これにより切断後の毛屑が刃穴２２から飛び出ようとするのを湾曲面３３・３４で受け止めて、内刃１２の内面側へ跳ね返すことができ、全体として切断後の毛屑がかみそりヘッド３の外面へ飛び出るのをよく防止できる。 Further, by making the cross-sectional shape over the entire length of the small blade 21 be a bell mouth shape, the left and right curved surfaces 33 and 34 can be curved outwardly toward the outer surface of the inner blade 12. As a result, it is possible to catch the fluff after cutting out of the blade hole 22 by the curved surfaces 33 and 34 and to bounce it back to the inner surface side of the inner blade 12, so that the flint after cutting as a whole is the razor head 3. It can be well prevented from jumping out to the outer surface.

凹縁部２６と凸縁部２７との間の中間位置付近の切刃３５は、斜めに大きく傾斜しており、しかも概ね直線状となるので、いわゆる引き切り作用を発揮して、円滑にひげ切断を行なうことができる。波形に形成した小刃２１の多数個所で、外刃１０の刃面を同時に受け止めることができるので、肌面から受ける押し付け反力によって、外刃１０の刃面の一部が刃穴２２内へ落ち込むのを確実に防止できる。 The cutting edge 35 in the vicinity of the intermediate position between the concave edge portion 26 and the convex edge portion 27 is greatly inclined obliquely and substantially linear, so that a so-called pulling action is exhibited and the whiskers are smoothly smoothed. Cutting can be performed. Since the blade surface of the outer blade 10 can be received simultaneously at many points of the small blade 21 formed in a waveform, a part of the blade surface of the outer blade 10 enters the blade hole 22 by the pressing reaction force received from the skin surface. It can be surely prevented from falling.

図７ないし図９に、本発明に係る小刃２１の形成パターンを変更した別の実施例を示す。図７においては、小刃２１の平面視形状を、凹縁部２６と凸縁部２７とを直線縁で繋いで、凹縁部２６と凸縁部２７とがく字状に連続するジグザグ状の屈曲形状とした。このように小刃２１をジグザグ状に形成すると、凹縁部２６と凸縁部２７とを繋ぐ斜めの直線縁の合計長さを大きくでき、したがって、内刃１２が往復駆動されるときに、斜めの直線縁の引き切り作用によって、ひげを効果的に切断できる。他は、上記の実施例と同じであるので、同じ部材に同じ符号を付してその説明を省略する。以下の実施例においても同じとする。 7 to 9 show another embodiment in which the formation pattern of the blade 21 according to the present invention is changed. In FIG. 7, the planar view shape of the small blade 21 is a zigzag shape in which the concave edge portion 26 and the convex edge portion 27 are connected in a straight line shape by connecting the concave edge portion 26 and the convex edge portion 27 with a straight edge. A bent shape was adopted. When the small blades 21 are formed in a zigzag shape in this way, the total length of the oblique straight edges connecting the concave edge portion 26 and the convex edge portion 27 can be increased. Therefore, when the inner blade 12 is driven to reciprocate, The beard can be effectively cut by the action of the diagonal straight edges. Others are the same as those in the above-described embodiment, and therefore, the same members are denoted by the same reference numerals and description thereof is omitted. The same applies to the following embodiments.

図７に示す内刃ブランク１１における小刃２１の断面形状を図８に示している。なお、図８（ａ）から図８（ｄ）の各図は、図７におけるＥ−Ｅ線、Ｆ−Ｆ線、Ｇ−Ｇ線、Ｈ−Ｈ線での断面を示している。
この実施例における各部の寸法、角度、および断面積の関係は以下通りとなる。
Ｗ＞Ｂ３＞（Ｂ２≒Ｂ１）
α４＞α２＞α３＞α１
Ｓ３＞（Ｓ２≒Ｓ１） FIG. 8 shows a cross-sectional shape of the small blade 21 in the inner blade blank 11 shown in FIG. In addition, each figure of Fig.8 (a)-FIG.8 (d) has shown the cross section in the EE line, FF line, GG line, and HH line in FIG.
The relationship among the dimensions, angles, and cross-sectional areas of the respective parts in this example is as follows.
W>B3> (B2≈B1)
α4>α2>α3> α1
S3> (S2≈S1)

せん断面３１の幅Ｗは、一方の基端部２８から他方の基端部２８にわたって一定である。非せん断面３２の幅は、凹縁部２６および凸縁部２７が形成してある位置の幅Ｂ１と、隣接する凹縁部２６と凸縁部２７との中間位置の幅Ｂ２とが略同じに設定してあり、基端部２８における非せん断面３２の幅Ｂ３は最大になっている（Ｂ３＞Ｂ２≒Ｂ１）。 The width W of the shear surface 31 is constant from one base end portion 28 to the other base end portion 28. The width of the non-shear surface 32 is substantially the same as the width B1 of the position where the concave edge portion 26 and the convex edge portion 27 are formed, and the width B2 of the intermediate position between the adjacent concave edge portion 26 and the convex edge portion 27. The width B3 of the non-shear surface 32 at the base end portion 28 is maximized (B3> B2≈B1).

凹縁部２６および凸縁部２７における非せん断面３２幅方向中央は、せん断面３１の幅方向中心Ｐから左右方向へ交互に偏寄させてあり、これにより左右の湾曲面３３・３４の抉り深さＭ・Ｎが異ならせてある。また、両縁部２６・２７の中間位置の非せん断面３２の幅方向中央は、せん断面３１の幅方向中心Ｐに位置させてある。このように、非せん断面３２の幅を基端部２８以外で概ね一致させ、さらに凹縁部２６および凸縁部２７における非せん断面３２を幅方向中心Ｐから交互に偏寄させるようにすると、湾曲面３３・３４の形状を左右で非対称として、小刃２１の断面を左右で非対称のベルマウス形状とすることができる。また、小刃２１の長手方向の強度を概ね均一にできるので、内刃ブランク１１をプレス加工で逆Ｕ字状に折り曲げるときに、曲げ応力が大きく作用するＵ字頂部の曲げ変形を円滑に行なって、内刃１２の曲げ加工を的確に行なうことができる。 The center in the width direction of the non-shear surface 32 in the concave edge portion 26 and the convex edge portion 27 is alternately offset in the left-right direction from the width-direction center P of the shear surface 31, thereby turning the left and right curved surfaces 33, 34. The depths M and N are different. Further, the center in the width direction of the non-shear surface 32 at the intermediate position between the two edge portions 26 and 27 is positioned at the center P in the width direction of the shear surface 31. As described above, when the width of the non-shear surface 32 is substantially matched except for the base end portion 28, and the non-shear surface 32 in the concave edge portion 26 and the convex edge portion 27 is alternately offset from the center P in the width direction. The shape of the curved surfaces 33 and 34 can be asymmetrical on the left and right, and the cross-section of the small blade 21 can be asymmetrical bell mouth. Further, since the strength in the longitudinal direction of the small blade 21 can be made substantially uniform, when the inner blade blank 11 is bent into an inverted U shape by pressing, the U-shaped top portion where bending stress acts greatly is smoothly bent. Thus, the inner blade 12 can be accurately bent.

図９においては、小刃２１の平面視形状を、凹縁部２６と凸縁部２７とを直線縁で繋いで、凹縁部２６と凸縁部２７とが交互に連続する稲妻形の屈曲形状とした。このように、小刃２１を稲妻形に形成すると、凹縁部２６と凸縁部２７の隣接ピッチが小さい部分と、両者２６・２７の隣接ピッチが大きい部分とが形成される。隣接ピッチが大きい部分には、図８で説明した小刃２１と同様に、凹縁部２６と凸縁部２７とを繋ぐ斜めの直線縁が長く形成されるので、この直線縁の引き切り作用によって、ひげを効果的に切断できる。また、隣接ピッチが小さい部分に臨む凹縁部２６の側においては湾曲面３３（または３４）が３次元平面状に形成されるので、切刃３５の角度α１が小さい場合にも、切刃３５の強度を向上できる。先の各実施例に比べて、凹縁部２６の形成個所数を６箇所に増加できる利点もある。 In FIG. 9, the shape of the small blade 21 in plan view is a lightning-shaped bend in which the concave edge 26 and the convex edge 27 are alternately connected by connecting the concave edge 26 and the convex edge 27 with a straight edge. Shaped. In this way, when the small blade 21 is formed in a lightning bolt shape, a portion where the adjacent pitch between the concave edge portion 26 and the convex edge portion 27 is small and a portion where the adjacent pitch between both the pins 26 and 27 is large are formed. In the portion where the adjacent pitch is large, an oblique straight edge connecting the concave edge portion 26 and the convex edge portion 27 is formed long like the small blade 21 described in FIG. Can effectively cut the beard. In addition, since the curved surface 33 (or 34) is formed in a three-dimensional plane on the side of the concave edge portion 26 facing the portion where the adjacent pitch is small, the cutting blade 35 is formed even when the angle α1 of the cutting blade 35 is small. The strength of can be improved. Compared to the previous embodiments, there is also an advantage that the number of forming portions of the concave edge 26 can be increased to six.

図１０ないし図１１は、本発明に係る内刃１２の構造を変更した別の実施例を示す。そこでは、小刃２１を内刃１２の駆動方向に対して斜めに傾斜する直線リブ状に形成した。小刃２１は、せん断面３１と、非せん断面３２と、左右の湾曲面３３・３４とで構成するが、図１１（ａ）に示すように、左右の湾曲面３３・３４の抉り深さＭ・Ｎを異ならせて、小刃２１の断面が左右で非対称のベルマウス状になるようにした。各小刃２１においては、せん断面３１の左側縁（一側縁）に限って、他の切刃部位より小さな角度α１の切刃３５を形成するようにした。また、図１１（ｂ）に示すように、基端部２８における非せん断面３２の幅をせん断面３１と同じ幅にして、その断面形状を概ね四角形状とすることにより、基端部２８の断面積Ｓ３を他より大きくした。 10 to 11 show another embodiment in which the structure of the inner blade 12 according to the present invention is changed. In this case, the small blade 21 is formed in a linear rib shape inclined obliquely with respect to the driving direction of the inner blade 12. The small blade 21 is composed of a shearing surface 31, a non-shearing surface 32, and left and right curved surfaces 33 and 34. As shown in FIG. The cross section of the small blade 21 is asymmetrical bell mouth shape on the left and right sides by making MN different. In each of the small blades 21, only the left edge (one side edge) of the shear surface 31 is formed with a cutting edge 35 having an angle α 1 smaller than that of the other cutting blade portions. Further, as shown in FIG. 11B, the width of the non-shear surface 32 in the base end portion 28 is set to the same width as that of the shear surface 31 and the cross-sectional shape thereof is substantially a square shape. The cross-sectional area S3 was made larger than the others.

上記のように、小刃２１の平面視形状を直線状にする場合には、切刃角度α１が小さな切刃３５を、小刃２１の前後方向に沿って連続する状態で形成できる。したがって、内刃１２の往動時、あるいは復動時の少なくともいずれかにおいて、切れ味のシャープな切刃３５でひげを一斉に切断して、内刃１２の全体の切れ味を向上できる。 As described above, when the planar view shape of the small blade 21 is linear, the cutting blade 35 having a small cutting edge angle α 1 can be formed in a state of being continuous along the front-rear direction of the small blade 21. Therefore, at least one of the forward movement and the backward movement of the inner blade 12 can cut the whiskers all at once with the sharp cutting blade 35 to improve the overall sharpness of the inner blade 12.

図１１においては、切刃角度α１が小さな切刃３５を、せん断面３１の左側縁に限って形成したが、その必要はなく、切刃角度α１が小さな切刃３５はせん断面３１の左右それぞれに形成することができる。例えば、図１２に示すように、左端の小刃２１において、せん断面３１の左側に角度α１が小さな切刃３５を形成する場合には、その右隣に位置する小刃２１においては、せん断面３１の右側に角度α１が小さな切刃３５を形成する。さらに、右端に位置する小刃２１においては、左端の小刃２１と同様に、せん断面３１の左側に角度α１が小さな切刃３５を形成する。このように、角度α１が小さな切刃３５の形成位置を、隣接する小刃２１ごとに左右に異ならせると、内刃１２が左または右へ駆動されるときの小刃２１の切れ味を概ね均等にできる。 In FIG. 11, the cutting blade 35 having a small cutting edge angle α1 is formed only on the left edge of the shearing surface 31, but this is not necessary, and the cutting blades 35 having a small cutting blade angle α1 are respectively left and right of the shearing surface 31. Can be formed. For example, as shown in FIG. 12, when the cutting edge 35 having a small angle α1 is formed on the left side of the shearing surface 31 in the cutting edge 21 at the left end, A cutting edge 35 having a small angle α1 is formed on the right side of 31. Further, in the small blade 21 positioned at the right end, a cutting blade 35 having a small angle α1 is formed on the left side of the shearing surface 31 in the same manner as the small blade 21 at the left end. As described above, when the formation position of the cutting blade 35 having a small angle α1 is changed to the left and right for each of the adjacent small blades 21, the sharpness of the small blade 21 when the inner blade 12 is driven to the left or right is approximately equal. Can be.

上記の実施例では、凹縁部２６と凸縁部２７を小刃２１の長手方向へ２〜２．５ピッチ分だけ繰り返し形成した場合の小刃形状を示したが、その必要はなく、凹凸縁部２６・２７の隣接ピッチを大小に変更して、小刃２１の長手方向への繰り返し形成回数を任意に設定することができる。また、小刃２１はく字状やＳ字、あるいはＩ字状に形成することができる。Ｉ字状に形成する場合には、小刃２１を内刃１２の駆動方向に対して直交する直線リブ状に形成する。 In the above embodiment, the shape of the small blade is shown when the concave edge portion 26 and the convex edge portion 27 are repeatedly formed in the longitudinal direction of the small blade 21 by 2 to 2.5 pitches. By changing the adjacent pitch of the edge portions 26 and 27 to be larger or smaller, the number of repeated formations in the longitudinal direction of the blade 21 can be arbitrarily set. The small blade 21 can be formed in a square shape, an S shape, or an I shape. When forming in I shape, the small blade 21 is formed in the linear rib shape orthogonal to the drive direction of the inner blade 12.

図５で説明した実施例においては、小刃２１の長手方向に隣接する凹縁部２６と凸縁部２７の各断面形状が線対称になるようにしたが、その必要はなく、凹縁部２６と凸縁部２７の各断面形状は僅かに異なっていてもよい。図１０、図１１および図１２で説明した内刃１２における小刃２１の断面積は、切断頻度が高い前後中央付近の断面積を最小にして、基端部２８へ向かって徐々に増加するように形成することができる。 In the embodiment described with reference to FIG. 5, the cross-sectional shapes of the concave edge portion 26 and the convex edge portion 27 adjacent to each other in the longitudinal direction of the blade 21 are symmetrical with each other. Each cross-sectional shape of 26 and the convex edge part 27 may differ slightly. 10, 11, and 12, the cross-sectional area of the small blade 21 in the inner blade 12 gradually increases toward the base end portion 28 while minimizing the cross-sectional area near the front and rear center where the cutting frequency is high. Can be formed.

１０外刃
１２内刃
２１小刃
２６凹縁部
２７凸縁部
２８基端部
３１せん断面
３２非せん断面
３３湾曲面
３４湾曲面
３５切刃 DESCRIPTION OF SYMBOLS 10 Outer blade 12 Inner blade 21 Small blade 26 Concave edge part 27 Convex edge part 28 Base end part 31 Shear surface 32 Non-shear surface 33 Curved surface 34 Curved surface 35 Cutting blade

Claims

An electric razor having an outer cutter (10) and an inner cutter (12), the inner cutter (12) being driven reciprocally along the inner surface of the outer cutter (10),
The inner blade (12) includes a pair of front and rear mounting walls (20, 20) and a group of small blades (21) long in the front-rear direction connecting the mounting walls (20, 20).
The blade (21) has a shearing surface (31) and a non-shearing surface (32) parallel to each other, and left and right curved surfaces (33, 34) that sandwich the wall between the left and right side edges of both (31, 32). And the cross section is configured in a bell mouth shape,
On both the left and right edges of the shearing surface (31) of the small blade (21), sharp cutting edges (35, 35) are formed, respectively.
The cross-section of the small blade (21) is formed in an asymmetric bell mouth shape on the left and right sides by varying the depth (M · N) of the left and right curved surfaces (33, 34), and one side of the shear surface (31). An electric shaver provided with an inner blade, characterized in that a cutting blade (35) having an angle (α1) smaller than that of other cutting blade portions is formed on the edge.

The planar view shape of the blade (21) in the unfolded state is formed into a bent shape in which the concave edge portion (26) and the convex edge portion (27) are alternately arranged,
The depth (M) of the curved surface (33) in the concave edge (26) is made larger than the others, and the angle (α1) of the cutting edge (35) in the concave edge (26) The electric shaver according to claim 1, further comprising an inner blade set smaller.

The cross-sectional shape of the blade (21) is continuously and smoothly changed between the concave edge portion (26) and the convex edge portion (27) adjacent to each other in the longitudinal direction of the blade (21). The described electric razor.

In the concave edge portion (26) and the convex edge portion (27) adjacent to the longitudinal direction of the small blade (21), the cross-sectional shape of the small blade (21) in the concave edge portion (26) and the convex edge portion (27) The electric shaver according to claim 2 or 3, wherein the cross-sectional shape of the blade (21) is axisymmetric.

The inner blade (12) includes rib-shaped small blades (21) and slit-shaped blade holes (22) alternately,
The small blade portion between the end portions of the adjacent blade holes (22) is the base end portion (28) of the small blade (21),
The base end portion is formed by making the depth of curvature of the curved surface (33 , 34 ) at the base end portion (28) of the small blade (21) smaller than the depth of drilling of the small blades (21) other than the base end portion (28). The electric shaver according to claim 1, 2, 3 or 4, wherein the cross-sectional area (S3) of (28) is set to be larger than the cross-sectional area other than the base end (28) of the blade (21).

The base end portion (28) of the small blade (21) is linearly extended from the mounting wall (20, 20) in a direction substantially orthogonal to the reciprocating drive direction of the inner blade (12). Electric razor.

The planar view shape of the small blade (21) in the unfolded state is formed in a waveform in which concave edge portions (26) and convex edge portions (27), which are curved, are alternately continuous, respectively. The electric razor according to crab.

The small blade widths (B1 and B2) of the non-shear surface (32) excluding the base end (28) are set to be substantially constant,
The center in the width direction of the non-shear surface (32) in the concave edge portion (26) and the convex edge portion (27) is alternately offset in the left-right direction from the width direction center (P) of the shear surface (31),
The center in the width direction of the non-shear surface (32) at an intermediate position between the concave edge portion (26) and the convex edge portion (27) is located at the width direction center P of the shear surface (31). The electric razor according to any one of the above.

The cutting edge (35) having a smaller angle (α1) than the other cutting edge portions is formed on one side edge of the shearing surface (31), with the planar view shape of the small blade (21) in the expanded state being linear. The electric razor according to claim 1.