JP2010264140A - Electric razor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric razor, provided with an cutter, capable of improving sharpness while sufficiently securing structural strength of a small blade, and effectively preventing leak of hair to the outside surface after cutting. <P>SOLUTION: The rib-shaped small blade 21 to compose the cutter 12 is formed of a shearing surface 25 on the outer surface, a non-shearing surface 26 on an inner surface, and a right and a left side parts 27 inwardly recessed in curvature. On the right and the left of the shearing surface 25, sharp cutting edges 28 are formed to secure sharpness of the cutter 12. The total width W at the top of the small blade 21 is set to be almost similar to the total width B at the base end of the small blade 21. An angle &alpha;2 of the cutting edge 28 at the base end part is set to be larger than an angle &alpha;1 of the cutting edge at the top. Sectional area S2 of the small blade 21 at the base end is set to be larger than sectional area S1 of the small blade 21 at the top to secure structural strength of the small blade 21. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electric shaver provided with an inner blade having a slit blade structure formed by an etching method.

  Although the inner blade of the slit blade structure is bent, for example, in an inverted U shape, Patent Document 1 discloses that adjacent small blades are connected by a reinforcing rib in order to increase the structural strength of each small blade. . Furthermore, in patent document 1, the width dimension of the small blade near the top part of the inner blade is made larger than the width dimension of the small blade at the base end part, so that a relatively short whiskers can be easily introduced on the top side. It makes it easy to introduce long hairs and comb hairs.

  Regarding the width dimension of the small blade, Patent Document 2 shows that the width dimension of the base end portion of the small blade is made larger than the width dimension of the top portion of the small blade. The base end portion of the small blade is formed in an isosceles trapezoidal shape, and the small blade is formed with an equal width in a state where the upper sides are connected to each other.

  In the inner blade of the slit blade structure according to the present invention, the cross-section of the rib-shaped small blade is formed in an isosceles trapezoidal shape or an inverted isosceles trapezoidal shape. This kind of small blade structure is known in Patent Document 3. . Here, the cross section of the small blade is formed in an isosceles trapezoidal shape, and the hypotenuse portion is curved in an indented shape. An acute angle cutting blade is provided on the side of the small blade that is in sliding contact with the outer blade, and a trapping blade for capturing the beard is provided on both sides of the non-shear surface of the small blade. The width dimension of the catching blade is set to be larger than the width dimension of the cutting edge. By capturing the whisker with the catching blade prior to the cutting edge, the whisker can be dragged toward the inner surface side of the inner blade and deeply shaved.

JP 08-126781 (paragraph numbers 0012 to 0013, FIG. 4) Japanese Patent Publication No. 49-017507 (page 2, lines 26-27, Fig. 4) JP 2007-215595 A (paragraph number 0027, FIG. 1)

  According to the inner blades of Patent Documents 1 and 2, the structural strength of the small blade can be improved by the reinforcing ribs and the isosceles trapezoidal base end structure. However, since the angle of the cutting edge portion provided on both side edges of the small blade is approximately 90 degrees, the sharpness is dull and lacks sharpness. Further, in the inner blade of Patent Document 1, the reinforcing ribs obstruct the introduction of the whiskers. Further, since the width dimension of the small blade near the top is made larger than the width dimension of the small edge at the base end portion, it is inevitable that the capture rate of the whiskers is lowered as a whole, and it takes much time for cutting the whiskers.

  In that respect, according to the inner blade of Patent Document 3, the cutting blades on both sides of the small blade are formed at an acute angle, so that sharper sharpness can be exhibited compared to the previous small blade. However, since the cross-sectional shape and the blade width of the blade are both the same in the longitudinal direction of the blade, a large bending moment is likely to act on the proximal end portion of the blade when cutting the beard.

  The objective of this invention is providing the electric shaver provided with the inner blade which can improve sharpness, fully ensuring the structural strength of a small blade. The objective of this invention is providing the electric shaver provided with the inner blade which can perform the press work of an inner blade blank exactly.

  The present invention is premised on an electric razor having left and right laterally long outer blades 10 and an inner blade 12, and the inner blade 12 is driven to reciprocate along the inner surface of the outer blade 10. The inner blade 12 includes rib-shaped small blades 21 and slit-shaped blade holes 22 alternately. The small blade 21 is formed by an outer shearing surface 25, an inner non-shearing surface 26, and left and right side portions 27 that are curved in an indented shape. Further, the cross-sectional shape of the small blade 21 including the top is formed in an inverted isosceles trapezoidal shape, and acute cutting edges 28 are provided on the left and right side edges of the shear surface 25. The full width W at the top of the small blade 21 and the full width B at the base end of the small blade 21 are set to be substantially the same. Accordingly, the angle α2 of the cutting edge 28 at the base end portion is set to be larger than the angle α1 of the cutting edge at the top portion, and the cross-sectional area S2 of the small blade 21 at the base end portion is set to the cross-sectional area S1 of the small blade 21 at the top portion. Set larger.

  The blade width B2 of the non-shear surface 26 at the base end is set to be larger than the blade width W2 of the non-shear surface 26 at the top.

  The small blade width W 2 · B 2 on the non-shear surface 26 is gradually increased from the top to the base end of the small blade 21.

  The small blade width W1 of the shearing surface 25 at the top and the small blade width B1 of the shearing surface 25 at the base end are set to be substantially the same. The small blade width B1 of the shearing surface 25 at the base end is set to be larger than the small blade width B2 of the non-shearing surface 26 at the base end, and the cross section from the top of the small blade 21 to the base end is indented. It is formed in an inverted isosceles trapezoidal shape with a hypotenuse 27.

  The small blade width W1 of the shearing surface 25 at the top and the small blade width B1 of the shearing surface 25 at the base end are set to be substantially the same. The cutting edge width B1 of the shearing surface 25 at the base end portion is set equal to the cutting edge width B2 of the non-shearing surface 26 at the base end portion, and the cross section of the cutting edge 21 at the base end portion is set to be an indented side. It is formed in a quadrangular shape with a portion 27.

  The small blade width B1 of the shear surface 25 at the base end portion is set smaller than the small blade width W1 of the shear surface 25 at the top portion. The small blade width B2 of the non-shear surface 26 at the base end portion is set larger than the small blade width B1 of the shear surface 25 at the base end portion, and the cross-section of the small blade 21 at the base end portion is a slanted side portion 27 having an indented shape. Is formed in an isosceles trapezoidal shape.

  The small blade width B1 of the shear surface 25 at the base end portion is set smaller than the small blade width W1 of the shear surface 25 at the top portion. The small blade width B1 of the shearing surface 25 at the base end portion is set larger than the small blade width B2 of the non-shearing surface 26 at the base end portion, and the cross-section of the small blade 21 at the base end portion is a slanted side portion 27 having an indented shape. It is formed in a reverse isosceles trapezoid shape.

  The present invention is premised on an electric razor having left and right laterally long outer blades 10 and an inner blade 12, and the inner blade 12 is driven to reciprocate along the inner surface of the outer blade 10. The inner blade 12 includes rib-shaped small blades 21 and slit-shaped blade holes 22 alternately. The small blade 21 is formed by an outer shearing surface 25, an inner non-shearing surface 26, and left and right side portions 27 curved in an indented shape, and a cross section extending from the top to the base end of the small blade 21 is equal. It is formed into a leg trap shape. The full width W at the top of the small blade 21 and the full width B at the base end of the small blade 21 are set to be substantially the same. The small blade width B1 of the shearing surface 25 at the base end portion is set to be larger than the small blade width W1 of the shearing surface 25 at the top portion, and the cross-sectional area S2 of the small blade 21 at the base end portion is determined by the cutting of the small blade 21 at the top portion. It is set larger than the area S1.

  In the present invention, in the inner blade 12 having a slit blade structure, the shearing surface 25 and the non-shearing surface 26 and the inner concave side portion 27 form the small blade 21, and the cross-sectional shape of the small blade 21 including the top portion. Are formed in an inverted isosceles trapezoidal shape, and sharp cutting edges 28 are provided on the left and right side edges of the shearing surface 25. In addition, the cross-sectional area S2 of the small blade 21 at the base end portion is made larger than the cross-sectional area S1 of the small blade 21 at the top portion to enhance the strength of the base end portion where the bending moment tends to concentrate, and the structure of the small blade 21 Increased strength. Therefore, according to the present invention, it is possible to efficiently cut the whiskers by sufficiently securing the structural strength of the small blade 21 while improving the sharpness by the sharp cutting edge 28. In addition, since the cross-sectional shape of the small blade 21 including the top, which has a higher cutting frequency than other parts, is formed in an inverted isosceles trapezoidal shape, it is the hypotenuse that the chips after cutting are about to jump out of the blade hole 22 It can be received by the portion 27 and bounced back to the inner surface side of the inner blade 12, and it is possible to well prevent the cut fuzz from jumping to the outer surface of the razor head 3.

  When the blade width B2 of the non-shear surface 26 at the base end is set larger than the blade width W2 of the non-shear surface 26 at the top, the difference between the cross-sectional area S2 of the base end and the cross-sectional area S1 of the top is further increased. Thus, the structural strength of the small blade 21 can be further improved. Moreover, it can suppress that the cut | judged fluff jumps out from the base end part side by the part which the small blade width B2 of the non-shear surface 26 in a base end part is large.

  When the blade width W2 · B2 on the non-shear surface 26 is gradually increased from the top to the base end of the blade 21, the cross-sectional area of the blade 21 gradually and steplessly from the top to the base end. Can be bigger. Therefore, when the inner blade blank 11 is bent into an inverted U shape by press working, the top blade where bending stress acts greatly can be smoothly deformed, and the inner blade 12 can be bent accurately.

  When the small blade width B1 of the shearing surface 25 at the base end portion is set to be larger than the small blade width B2 of the non-shearing surface 26, the cross section from the top of the small blade 21 to the base end portion is provided with a slanted side portion 27 having an indented shape. It can be formed in an inverted isosceles trapezoidal shape. That is, the entire cross section of the small blade 21 can be formed in an inverted isosceles trapezoidal shape, and the slanted side portion 27 can be formed in the shape of a concavity that hangs down to the left and right of the small blade 21. Accordingly, the slanted side portion 27 formed over the entire length in the longitudinal direction of the small blade 21 can receive the fluff that is about to jump out of the blade hole 22 and bounce it back to the inner surface side of the inner blade 12 or guide it to fall. It is possible to more reliably prevent the hair after cutting from jumping to the outer surface of the razor head 3.

  When the small blade width B1 of the shearing surface 25 at the base end portion and the small blade width B2 of the non-shearing surface 26 are set equal, the cross section of the small blade 21 at the base end portion is a square having an indented side portion 27. The cross-sectional area S2 of the base end portion can be maximized as compared with the case where the base end portion is formed in a shape and the cross section of the base end portion is formed in the shape of an isosceles trapezoid or an inverted isosceles trapezoid. Therefore, not only can the structure strength of the small blade 21 be sufficiently secured to effectively perform whisker cutting, but even in an extreme whisker cutting situation where the load during whisker cutting changes rapidly, The beard cutting can always be performed appropriately while maintaining the blade 21 in an appropriate cutting posture. Furthermore, since the small blade width B2 of the non-shear surface 26 at the base end portion is substantially the same as the small blade width W1 of the shear surface 25 at the top portion, it is more effective that the cut fuzz pops out from the base end side. Can be prevented.

  The blade width B1 of the shear surface 25 at the base end is set smaller than the blade width W1 of the shear surface 25 at the top, and the blade width B2 of the non-shear surface 26 at the base end is set to the blade width of the shear surface 25. The area of the shearing surface 25 of the small blade 21 can be reduced by setting the cross section of the small blade 21 at the base end portion to be isosceles trapezoidal by setting it larger than B1. As a result, the opening area on the outer surface side of the blade hole 22 can be increased by an amount corresponding to the small blade width B1 of the shearing surface 25 at the proximal end portion. Therefore, when cleaning the razor head 3 with water, the blade hole 22 at the proximal end portion is cleaned. It is possible to promote water intrusion into the inner surface of the inner blade and effectively perform cleaning with water. In addition, if the area of the shearing surface 25 of the small blade 21 at the base end is small, the sliding resistance when the small blade 21 near the base end is in sliding contact with the outer blade 10 at the time of cutting the whiskers is reduced, and the electric razor Power consumption can be reduced.

  When the small blade width B1 of the shearing surface 25 at the base end is set smaller than the small blade width W1 of the shearing surface 25 at the top, the cross section of the small blade 21 at the base end is formed in an inverted isosceles trapezoidal shape. While forming the entire cross section of the blade 21 in an inverted isosceles trapezoidal shape, the sliding resistance between the small blade 21 and the outer blade 10 can be reduced by the small blade width B1. Accordingly, it is possible to prevent the fluff from jumping to the outer surface of the razor head 3 by receiving the fluff that is about to jump out of the blade hole 22 by the inner concave inclined side portion 27, and to further reduce the sliding resistance. , Can reduce the power consumption of electric razor.

  In the electric razor of the present invention, in the inner blade 12 having the slit blade structure, the small blade 21 is formed by the shearing surface 25 and the non-shearing surface 26 and the inner concave side portion 27, and from the top to the base end. The cross-sectional shape of the leading small blade 21 is formed in an isosceles trapezoidal shape, and acute-angled cutting blades 28 are provided on both left and right edges of the shear surface 25. In addition, the cross-sectional area S2 of the blade 21 at the base end is made larger than the cross-sectional area S1 of the blade 21 at the top to enhance the strength of the base end where the bending moment tends to concentrate, thereby Increased strength. Therefore, according to the present invention, it is possible to efficiently cut the whiskers by sufficiently securing the structural strength of the small blade 21 while improving the sharpness by the sharp cutting edge 28. Furthermore, since the small blade width W1 of the shearing surface 25 at the top portion where the frequency of use is the largest is made smaller than other portions, the aperture ratio in the vicinity of the top portion can be increased to improve the whisker introduction effect, and the whisker cutting efficiency is increased accordingly. Can be done well.

It is a top view when an inner blade blank is seen from the non-shear surface side. It is a front view of an electric razor. It is a vertical side view of a razor head. It is the perspective view which decomposed | disassembled the inner blade. It is a front view of an inner blade unit. FIG. 6 is a sectional view taken along line ZZ in FIG. 5. FIG. 2 is a cross-sectional view taken along line XX and a cross-sectional view taken along line YY in FIG. 1. It is sectional drawing which shows the formation process of the small blade by an etching method. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade. It is a top view which shows another Example which changed the shape of the small blade. It is a top view which shows another Example which changed the shape of the small blade. It is a top view which shows another Example which changed the shape of the small blade. It is a top view which shows another Example which changed the shape of the small blade. It is a front view of the inner blade unit which shows another Example of the attachment structure of an inner blade. It is a perspective view of the inner blade holder which shows another Example of the attachment structure of an inner blade. It is sectional drawing which shows another Example of the cross-sectional shape of a small blade.

  1 to 8 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.

  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 is sealed with a molding packing provided between the razor head 3 and the main body case 1.

  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 pressed into the inner blade blank 11 indicated by an imaginary line in FIG. 4 and bent into an inverted U shape, and is fixed in an inverted U shape by the inner blade holder 13. is there. Details thereof will be described later. Further, as will be described later, the inner blade blank 11 is formed by an etching method.

  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.

  As shown in FIG. 1, the inner blank 11 has a horizontally long sheet body, and rib-shaped small blades 21 and slit-shaped blade holes 22 are alternately formed in the left-right direction on the surface wall of the sheet body. It is. 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, and fixing holes 40 that are round holes are formed on the left and right of each cutout 24. It is formed. A flange (thin wall portion) 41 by half etching is provided on the inner edge of the notch 24. The edge portion 42 at the inner edge of the flange 41 is formed in a tapered shape that swells inward. The meaning will be described later.

  As shown in FIG. 7, the blade 21 has an outer shear surface 25, an inner non-shear surface 26, and left and right oblique sides (side portions) 27 that are curved inwardly, and the cross section is reverse isosceles. Form a trapezoid. Along with this, acute cutting edges 28 are formed on the left and right side edges of the shearing surface 25, and these cutting edges 28 cut the beard in cooperation with the outer cutter 10. In addition, acute corner portions 29 similar to the previous cutting edge 28 are formed on the left and right side edges of the non-shear surface 26. 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 whisker cutting (shearing) through a very small gap.

  The inner blade blank 11 is formed by subjecting a stainless steel plate 30 having a thickness of 0.25 mm to an etching process. In the process, the face walls 25 to 27 constituting the small blade 21 are formed. As shown in FIG. 8, in the etching process, resist films 31 and 32 are formed on both the front and back surfaces of the stainless steel plate 30 and then exposed, and the exposed portions are removed and the surface of the plate surrounded by the resist pattern is etched with an etching solution.

  The resist pattern on the back side is formed larger than the resist pattern on the front side. Therefore, the degree of etching on the back surface side becomes larger than the surface of the stainless steel plate 30. The curved surface grown from the front surface (shear surface 25) side by etching and the curved surface grown from the back surface (non-shear surface 26) side eventually become one curved surface to form the hypotenuse 27. As the degree of etching on the back surface side is large, the shape is tapered toward the back surface side. As a result, the entire cross section of the small blade 21 is formed in an inverted isosceles trapezoid shape. Similarly, the notch 24 and the fixing hole 40 are formed by etching from both front and back surfaces. Therefore, the inner surface 43 of the fixing hole 40 is formed in a spherical shape whose upper and lower surfaces are open.

  In order to make the cross-sectional shape of the center portion (top) in the longitudinal direction of the small blade 21 different from the cross-sectional shape of the base end portion of the small blade 21, the front and back resist patterns are formed as follows. First, the width of the resist pattern on the front side is formed to be substantially the same width from the top of the blade 21 to both base ends. Therefore, the small blade width on the surface (shear surface 25) side is substantially the same width from the top of the small blade 21 to both base end portions. On the other hand, the width of the resist pattern on the back side is gradually increased from the top of the blade 21 to both base ends. Therefore, the small blade width on the back surface (non-shearing surface 26) side in the vicinity of the top of the small blade 21 is small, and the small blade width increases as the base end portion is approached. That is, the degree of etching on the back side near the top of the small blade 21 is increased, and the degree of etching on the back side becomes smaller as it approaches the base end. The oblique side portion 27 formed by the etching action is formed along the peripheral edge of the semicircular blade hole 22 at the edge portion of the blade hole as shown in FIG. A position corresponding to the top of the small blade 21 is indicated by a cross-section indicating line XX in FIG. 1, and a position corresponding to the base end portion of the small blade 21 is indicated by a cross-sectional indicating line YY in FIG. 1. Show.

FIG. 7 shows a cross-sectional shape of the small blade 21 in the inner blade blank 11 obtained through the etching process. FIG. 7A shows a cross section of the blade 21 at the top, and FIG. 7B shows a cross section of the blade 21 at the base end. In FIG.
W1 is the blade width of the shear surface 25 at the top, and is also the full width W.
W2 is the blade width of the non-shear surface 26 at the top.
B1 is the width of the small blade of the shear surface 25 at the base end, and is also the full width B.
B2 is the small blade width of the non-shear surface 26 at the base end.
α1 is the angle of the cutting edge 28 at the top.
α2 is the angle of the cutting edge 28 at the base end.
β1 is the angle of the corner 29 at the top.
β2 is the angle of the corner 29 at the base end.

The dimensions and angles of the above-mentioned parts in this embodiment are as follows.
(W1 = B1)
(B2> W2)
(Α2> α1)
(Β1> β2)

  As described above, after setting the full width W at the top of the small blade 21 and the full width B at the base end of the small blade 21 to be the same, the angle α2 of the cutting blade 28 at the base end is set to the cutting edge at the top. By setting it larger than the angle α1 of 28, the cross-sectional area S2 of the small blade 21 at the base end can be set larger than the cross-sectional area S1 of the small blade 21 at the top. This is because the smaller the angle of the cutting edge 28, the larger the volume of the etched portion that is struck by the hypotenuse 27. Further, since the cross-sectional area of the small blade 21 is gradually increased from the top toward the base end, the strength of the base end can be improved and the structure strength of the small blade 21 as a whole can be made sufficient. . Further, the sharpness of the cutting blade 28 at the time of cutting the beard can be improved by setting the angle of the cutting blade 28 to an acute angle of 37 degrees.

  Since the left and right oblique sides 27 are curved outwardly toward the outer surface of the inner blade 12, the oblique sides 27 accept that the cut chips are about to jump out of the blade hole 22. It is possible to bounce back to the side, and it is possible to well prevent the cut hair as a whole from jumping to the outer surface of the razor head 3. In addition, since the cross-sectional area of the small blade 21 is gradually increased from the top toward the base end, when the inner blade blank 11 is bent into an inverted U shape by press working, bending of the top where bending stress acts greatly The inner blade blank 11 can be accurately bent by performing the deformation smoothly.

  The inner blade holder 13 is formed in a hollow frame shape that opens up and down by a pair of left and right tunnel cross-sectional side walls 45 and a holder base 46 that connects the front and rear surfaces of these side walls 45. A mounting seat 47 for assembling the inner blade 12 is formed on the front and rear holder bases 46, and protrusions 23 bulge on both the left and right sides of the front and rear mounting seats 47. Three reinforcing ribs 48 are integrally provided between the front and rear surfaces of the holder base 46, and a passive piece 19 that engages with the drive shaft 17 is provided at the lower end of the central reinforcing rib 48 (FIG. 5). reference).

  The inner blade 12 bent into an inverted U shape by pressing is assembled to the inner blade holder 13 having the above structure in the following manner. First, the entire inner blade 12 is pushed down from above the inner blade holder 13 while being applied to the mounting seat 47, and the notch 24 is engaged with the projection 23 as shown in FIG. At this time, as shown in FIG. 6, the edge portions 42 of the flange 41 bite into both side surfaces of the protrusion 23, temporarily fix the inner blade 12 without rattling, and simultaneously position it in the left-right direction and the up-down direction. In the process of engaging the notch 24 with the protrusion 23, the edge portion 42 is formed in a tapered shape, so that the notch 24 can be inserted into and engaged with the protrusion 23 more smoothly.

  In the above state, as shown in FIG. 6, the round shaft-shaped heating jig 51 is inserted from the fixing hole 40, and the tip portion thereof is pushed into the meat wall of the mounting seat 47. Thereby, the plastic melted by the heating jig 51 and pushed away at the end of the shaft enters the spherical inner surface 43 of the fixing hole 40. Therefore, by solidifying the plastic that has entered the fixing hole 40, the four corner portions of the inner blade 12 are fixed to the inner blade holder 13 in an inseparable manner, thereby completing the inner blade unit. The welded mass 52 in the solidified state substantially fills the fixing hole 40 but does not overflow from the inner surface 43.

The inner blade unit can be suitably implemented in the following form.
An inner blade unit composed of an inner blade 12 bent into an inverted U shape and an inner blade holder 13 for fixing and supporting the inner blade 12,
The inner blade holder 13 has a pair of left and right side walls 45 and a holder base 46 that connects the front and rear surfaces of both side walls 45, and is formed in a hollow frame shape that opens up and down.
A mounting base 47 for assembling the inner blade 12 is formed on the holder base 46, and protrusions 23 for fixing the inner blade 12 are provided at a plurality of locations on the mounting seat 47.
The inner blade 12 has a notch 24 inserted into and engaged with the protrusion 23, and a fixing hole 40 is formed in the vicinity of the notch 24.
A thinner flange 41 is formed on the inner edge of the notch 24,
When the inner blade 12 is assembled to the mounting seat 47 of the inner blade holder 13 and the notch 24 is engaged with the protrusion 23, the edge portion 42 of the flange 41 bites into the peripheral surface of the protrusion 23, and the inner blade 12 It is temporarily fixed to the holder 13,
By inserting the heating jig 51 into the fixing hole 40 of the inner blade 12 in the temporarily fixed state, the meat wall of the mounting seat 47 is melted, and the melted plastic is intruded into the fixing hole 40 to be solidified. Is an inner blade unit of an electric razor that is permanently fixed to the inner blade holder 13.

  According to the inner blade unit configured as described above, the edge portion 42 bites into the peripheral surface of the protrusion 23 in a state where the inner blade 12 is temporarily fixed to the mounting seat 47, so that the inner blade 12 is moved relative to the inner blade holder 13. Thus, the positioning can be performed accurately without rattling and the temporary fixed state can be maintained. Further, since the welding operation can be performed while the inner blade 12 is positioned, it is possible to concentrate exclusively on the welding operation, and the welding operation can be performed more reliably and easily. There is no need to use a positioning jig or a jig for holding the temporarily assembled state. In the conventional work mode, since it is necessary to perform the welding work in a state where the inner blade is positioned and held, the welding result may vary.

The edge portion 42 provided on the inner edge of the notch 24 is formed in a tapered shape that tapers from the insertion start end side of the notch 24 toward the insertion end side, that is, a taper shape that tapers inwardly of the notch 24. Can do.
In that case, the amount of biting of the edge portion 42 when biting into both side surfaces of the projection 23 is gradually increased, and the insertion engagement operation of the notch 24 with respect to the projection 23 can be performed smoothly and easily. . Note that the shape of the edge portion 42 does not have to be a tapered shape that is tapered toward the inner depth of the notch 24, and may be a U-shape similar to the notch 24. In that case, if the notch 23 is formed in an isosceles trapezoidal shape or a trapezoidal shape having a hypotenuse only on one side, the same biting action as when the edge 42 is formed in a tapered shape can be exhibited.

The fixing hole 40 can be simultaneously formed in the process of forming the inner blade 12 by an etching method.
In that case, the inner blade 12 can be fixed in an inseparable manner by filling the fixing hole 40 having the inner surface 43 formed in a spherical shape with molten plastic and then solidifying it. The inner blade 12 can be welded and fixed to the inner blade holder 13.

  Another embodiment of the inner blade 12 according to the present invention will be shown below. FIGS. 9 to 17 are views in which the cross-sectional shape of the blade 21 is changed, and FIGS. 18 and 19 are views in which the formation pattern of the blade 21 is changed. In any case, different parts from the above embodiment will be mainly described, and the same members as those in the above embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

  In FIG. 9, the small blade width B1 of the shearing surface 25 at the base end portion is slightly smaller than the small blade width W1 of the shearing surface 25 at the top portion. Strictly speaking, it becomes (W> B), but when W1 is 0.43 mm, the actual dimension can be regarded as (W≈B) because B1 is 0.38 mm. Further, the blade width B2 of the non-shear surface 26 at the base end portion was set to be larger than the blade width W2 of the non-shear surface 26 at the top portion (B2> W2). Also in this example, the cross section of the small blade 21 at the base end portion and the cross section of the small blade 21 at the top portion were each formed in an inverted isosceles trapezoidal shape. Further, regarding the cross-sectional area of the base portion and the top portion, the structural strength at the base end portion of the blade 21 was ensured so as to satisfy the relationship of (S2> S1). Similarly, in the examples of FIGS. 9 to 17, the relationship of (S2> S1) is satisfied.

  In FIG. 10, the small blade width W1 of the shear surface 25 at the top is the same as the small blade width B2 of the non-shear surface 26 at the base end portion, and is set to (W = B). Further, the small blade width B2 of the non-shear surface 26 at the base end portion was set larger than the small blade width B1 of the shear surface 25 (B2> B1). In this embodiment, the cross-section of the small blade 21 at the base end portion is formed in an isosceles trapezoidal shape so that the cross-sectional area of the top portion and the base end portion can satisfy the relationship of the formula (S2> S1). Thus, when the width of the small blade of the shear surface 25 is narrowed from the top to the base end, the structural strength of the small blade 21 can be improved while reducing the contact area of the small blade 21 with the outer blade 10. In addition, the amount of power consumed by the electric razor can be reduced by reducing the sliding resistance when cutting the whiskers by the amount that the contact area of the small blade 21 can be reduced.

  As in FIG. 10, the blade 21 shown in FIG. 11 is formed in the shape of an isosceles trapezoidal cross section at the base end, and the blade width B2 of the non-shear surface 26 at the base end is set at the top. It was made smaller than the small blade width W1 of the shearing surface 25. Strictly speaking, it becomes (W> B). However, when W1 is 0.43 mm, B2 is 0.38 mm, and can be regarded as (W≈B).

  The small blade 21 shown in FIG. 12 has a cross section of the small blade 21 at the base end portion formed in an inverted isosceles trapezoidal shape, and the small blade width B1 of the shear surface 25 at the base end portion is set to the small blade of the shear surface 25 at the top portion. It was larger than the width W1. Strictly speaking, it becomes (W <B). However, when W1 is 0.43 mm, the actual dimension can be regarded as (W≈B) because B1 is 0.45 mm. Thus, if the full width B at the base end portion is made larger than the full width W at the top portion, the cross-sectional area S2 of the base end portion can be enlarged and the structural strength of the blade 21 can be improved.

  The small blade 21 shown in FIG. 13 has an isosceles trapezoidal cross section at the proximal end portion, and the small blade width B2 of the non-shear surface 26 at the proximal end portion and the small blade of the shear surface 25 at the top portion. It was larger than the width W1. Strictly speaking, it becomes (W <B). However, when W1 is 0.43 mm, B2 is 0.45 mm, so that it can be regarded as (W≈B).

  The small blade 21 shown in FIG. 14 has a cross section of the small blade 21 at the base end portion formed in an inverted isosceles trapezoidal shape, and the small blade width B1 of the shear surface 25 and the small blade width of the non-shear surface 26 at the base end portion. Each of B2 was made larger than the small blade width W1 of the shearing surface 25 at the top. Strictly speaking, it becomes (W <B). However, when W1 is 0.43 mm, B1 is 0.48 mm and B2 is 0.45 mm (W≈B). it can.

  The small blade 21 shown in FIG. 15 has a cross-section of the small blade 21 at the base end portion in an isosceles trapezoidal shape, and the small blade width B1 of the shear surface 25 and the small blade width B2 of the non-shear surface 26 at the base end portion. Each was made larger than the small blade width W1 of the shearing surface 25 at the top. Strictly speaking, it becomes (W <B). However, when W1 is 0.43 mm, B1 is 0.45 mm and B2 is 0.48 mm (W≈B). it can.

  The small blade 21 shown in FIG. 16 is such that the oblique side 27 formed by the etching process ends at the base end, and the small blade width B1 of the shear surface 25 and the small blade width B2 of the non-shear surface 26 at the base end. Made the same. Thus, by setting (B1 = B2), the cross-sectional shape of the base end portion can be made into a quadrangular shape including the side portion 27 having an indented shape, and the cross-sectional area S2 at the base end portion is enlarged. The structural strength of the small blade 21 can be improved.

  The small blade 21 shown in FIG. 17 forms the oblique side portion 27 formed by the etching process only from the top to the vicinity of the base end, and the small blade width B1 of the shear surface 25 in a certain region including the base end The small blade width B2 of the non-shear surface 26 in a certain region including the base end portion was made the same. Thus, the structural strength of the blade 21 can be improved by setting (B1 = B2) in a certain region including the base end. The constant region including the base end portion can be selected within the range of the length of the small blade portion that does not slide in contact with the outer blade 10, and the cross-sectional shape thereof is a quadrangular shape including the side portion 27 having an indented shape. It becomes.

  The inner blade 12 shown in FIG. 18 has fleece discharge holes 35 formed at regular intervals adjacent to both end portions of the blade hole 22 of the inner blade 12 described in FIG. The fluff discharge hole 35 is formed for every two adjacent blade holes 22. Thus, by providing the fluff discharge hole 35, it is possible to prevent the cut fluff from accumulating inside the inner blade holder 13. In addition, at the time of washing with water, the chips in the inner blade 12 can be effectively discharged from the chip discharge holes 35 together with the drainage.

  The inner blade 12 shown in FIG. 19 is arranged with a group of small blades 21 and blade holes 22 inclined obliquely. Thus, the small blade 21 and the blade hole 22 do not need to be formed in parallel with the short side portion of the inner blade 12. Moreover, the small blade 21 can be formed in a partial arc shape as needed, or can be formed in a continuous waveform.

  FIG. 20 shows another embodiment in which the fixing structure of the inner blade 12 to the inner blade holder 13 is changed. In this case, the protrusions 23 are provided at the left and right centers of the mounting seats 47 before and after the inner blade holder 13. In addition, fixing holes 40 are provided in the left and right corners of the mounting wall before and after the inner blade 12 so that the inner blade 12 can be fixed to the mounting seat 47 with a welded mass 52 filled therein. Others are the same as those in the embodiment described with reference to FIG. 5, and therefore, the same reference numerals are given to equivalent members and the description thereof is omitted.

  In the embodiment of FIG. 20, a part of the mounting seat 47 is melted to form the welded mass 52, but if necessary, a welding projection 55 having a small protruding dimension at a position corresponding to the fixing hole 40 of the mounting seat 47. The amount of plastic filling the fixing hole 40 can be increased. In this case, as shown in FIG. 21, a welding projection 55 that engages with the fixing hole 40 is provided on the mounting seat 47 and is inclined downward from the upper end of the peripheral edge of the welding projection 55 toward the projection end surface of the projection. A guide surface 56 is provided. In this way, when the guide surface 56 is provided on the welding projection 55, the inner blade 12 can be guided over the guide surface 56 when the notch 24 is inserted and engaged with the projection 23, so that the welding projection 55 is attached to the mounting seat 47. Even if the inner blade 12 is provided, the inner blade 12 can be smoothly and temporarily fixed to the inner blade holder 13. In addition, the cross-sectional shape of the welding protrusion 55 can be formed in arbitrary cross-sectional shapes, such as a circle and a polygon. The inner blade holder 13 described in FIG. 21 is an embodiment in which a welding protrusion 55 is added to the mounting seat 47 of the inner blade holder 13 described in FIG. 4, but the welding protrusion 55 is the inner blade holder described in FIG. 13 can be added similarly.

  FIG. 22 shows still another embodiment of the inner blade 12. There, the small blade width W2 · B2 of the non-shear surface 26 at the top and the base end is set larger than the small blade width W1 · B1 of the shear surface 25 at the top and the base end, and the cross section of the small blade 21 is set. An isosceles trapezoidal shape was formed from the top to the base end. Further, the blade width W2 of the non-shear surface 26 at the top and the blade width B2 of the non-shear surface 26 at the base end are the same, but the blade width B1 of the shear surface 25 at the base end is set to the top. The cross-sectional area S2 of the base end portion is set to be larger than the cross-sectional area S1 of the top portion.

The dimensions and angles of the above-mentioned parts in this embodiment are as follows.
(W1 <B1)
(W2 = B2)
(Α2> α1)
(Β1 <β2)

  The inner blade 12 can be formed by performing an etching process on the press-molded inner blade blank 11. The present invention can be applied to all inner blades having a slit blade structure, and can be applied not only to a main blade but also to an inner blade of a center blade that mainly cuts long hairs and comb hairs.

10 Outer blade 12 Inner blade 21 Small blade 25 Shear surface 26 Non-shear surface 27 Side portion (slope side portion)
28 Cutting blade

Claims (8)

An electric razor having a laterally long outer cutter (10) and an inner cutter (12), the inner cutter (12) being driven to reciprocate along the inner surface of the outer cutter (10),
The inner blade (12) includes rib-shaped small blades (21) and slit-shaped blade holes (22) alternately,
The small blade (21) is formed by an outer shearing surface (25), an inner non-shearing surface (26), and left and right side portions (27) curved in an inner dent shape,
The full width (W) at the top of the small blade (21) and the full width (B) at the base end of the small blade (21) are set to be substantially the same,
The angle (α2) of the cutting edge (28) at the base end is set to be larger than the angle (α1) of the cutting edge at the top, and the cross-sectional area (S2) of the small blade (21) at the base end is An electric razor characterized by being set larger than the cross-sectional area (S1) of the small blade (21).   The electric shaver according to claim 1, wherein the blade width (B2) of the non-shear surface (26) at the base end portion is set larger than the blade width (W2) of the non-shear surface (26) at the top portion.   The electric shaver according to claim 1 or 2, wherein the blade width (W2 · B2) on the non-shear surface (26) is gradually increased from the top to the base end of the blade (21). The small blade width (W1) of the shear surface (25) at the top and the small blade width (B1) of the shear surface (25) at the proximal end are set to be substantially the same,
The small blade width (B1) of the shear surface (25) at the base end is set to be larger than the small blade width (B2) of the non-shear surface (26) at the base end, and the base from the top of the small blade (21). The electric razor according to claim 1, 2 or 3, wherein a cross section extending over the end portion is formed in an inverted isosceles trapezoidal shape having an indented oblique side (27). The small blade width (W1) of the shear surface (25) at the top and the small blade width (B1) of the shear surface (25) at the proximal end are set to be substantially the same,
The blade width (B1) of the shear surface (25) at the base end portion is set equal to the blade width (B2) of the non-shear surface (26) at the base end portion, and the blade (21) at the base end portion is set. The electric shaver according to claim 1, 2 or 3, wherein the cross section is formed in a quadrangular shape having a side portion (27) having an inner concave shape. The blade width (B1) of the shear surface (25) at the base end portion is set smaller than the blade width (W1) of the shear surface (25) at the top portion,
The blade width (B2) of the non-shear surface (26) at the base end portion is set larger than the blade width (B1) of the shear surface (25) at the base end portion, and the blade (21) at the base end portion is set. The electric razor according to claim 1, 2 or 3, wherein the cross section of said is formed in an isosceles trapezoidal shape with an inclined side portion (27) having an indented shape. The blade width (B1) of the shear surface (25) at the base end portion is set smaller than the blade width (W1) of the shear surface (25) at the top portion,
The blade width (B1) of the shear surface (25) at the base end portion is set to be larger than the blade width (B2) of the non-shear surface (26) at the base end portion, and the blade (21) at the base end portion is set. The electric razor according to claim 1, 2 or 3, wherein the cross section is formed in an inverted isosceles trapezoidal shape having an indented oblique side (27). An electric razor having a laterally long outer cutter (10) and an inner cutter (12), the inner cutter (12) being driven to reciprocate along the inner surface of the outer cutter (10),
The inner blade (12) includes rib-shaped small blades (21) and slit-shaped blade holes (22) alternately,
The small blade (21) is formed by an outer shearing surface (25), an inner non-shearing surface (26), and left and right side portions (27) curved in an indented shape. The cross section from the top to the base end is formed in an isosceles trapezoid shape,
The full width (W) at the top of the small blade (21) and the full width (B) at the base end of the small blade (21) are set to be substantially the same,
The cross-sectional area of the blade (21) at the base end is set by setting the blade width (B1) of the shear surface (25) at the base end to be larger than the blade width (W1) of the shear surface (25) at the top. An electric shaver in which (S2) is set larger than the cross-sectional area (S1) of the blade (21) at the top.

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