JP2008206567A - Electric shaver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric shaver capable of sufficiently exerting spring characteristics required for a tension spring while forming the tension spring flush with the surface wall of a cutter, simplifying the tension structure of the cutter, and being simply assembled with reduced manhours. <P>SOLUTION: The tension spring 24 is formed integrally with a screen wall 21 of the cutter 11. The screen wall 21 of the cutter 11 in a developed state is alternately formed with spring elements 30 and partition spaces 31 and the plurality of spring elements 30 constitute the tension spring 24. Each spring element 30 consists of an upper support wall 33, a lower support wall 33, an upper spring arm 35 and a lower spring arm 36 continued to the support wall 33 and 34, an arm end wall 37 connecting the side ends of the upper/lower spring arms 35 and 36, and a separation slit 38 formed between the upper/lower spring arms 35 and 36. The upper/lower spring arms 35 and 36 and the upper/lower support wall 33 and 34 are elastically deformed in the mutually separating direction to tension and energize the cutter 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an outer blade of an electric razor, and more particularly to a tension structure of the outer blade.

  In electric razors, a tension structure is used between the outer blade and the outer blade holder to prevent the outer blade from floating away from the inner blade due to sudden fluctuations in the cutting load, or damage to the outer blade due to excessive cutting load. Provided. In many cases, the tension structure includes a small torsion coil spring, a leaf spring, or a plastic-molded spring as a buffer, and the work of assembling the outer blade, the tension spring, or the like on the inner surface of the outer blade holder is likely to be complicated. Providing a tension spring integrally with the outer blade has been proposed for a long time in order to eliminate the complexity of such assembling work and to further simplify the tension structure and realize cost reduction (Patent Document 1, 2, 3).

  In Patent Document 1, a tension spring provided with a pair of spring arms is bent on one side of the front and rear edges of the outer blade, and the free ends of both spring arms are hooked and attached to the inner surface recess of the outer blade holder. The arm is bent and deformed to pull and urge the outer blade toward the tension spring. In patent document 2, a leg part is provided in the right and left of the front-and-back edge of an outer blade, and the protrusion side of each leg part is each wound in the shape of a spiral, and is used as the tension spring. In Patent Document 3, burring is performed on both corners of one side edge of the outer blade to form a rectangular retaining hole, and the periphery of the retaining hole excluding the bridging portion at the center of each side portion is an L-shape. It is surrounded by a notch, and further, the outside of the bridge is surrounded by a notch parallel to each side, and the divided face wall around the retaining hole is used as a tension spring. The latching hole is latched by an engaging projection provided on the inner surface of the outer blade holder.

Japanese Utility Model Publication No. 54-13792 (Page 2, lines 7-11, Fig. 3) JP-A-60-100991 (page 3, upper right column, second sentence, FIG. 1) Japanese Utility Model Publication No. 54-44092 (Page 3, lines 3-12, Fig. 3)

  Each of the conventional tension springs described above is formed by pressing a metal sheet material for forming an outer blade. For this reason, the position accuracy and shape accuracy of the tension springs are likely to vary, and therefore, the tension forces of the individual outer blades tend to vary. Since the outer blade of Patent Document 1 pulls and biases the outer blade using the elasticity when the spring arm is bent and deformed in the thickness direction, the spring has a good response and the spring has a large elastic deformation range. Similarly, the tension spring of Patent Document 2 basically uses the elasticity when the spring portion bends and deforms in the thickness direction, and the thickness direction merely changes continuously in a spiral shape. The spring response is good and the elastic deformation range of the spring is large. However, in any case, the tension spring protrudes greatly on the outer surface of the face wall of the outer blade, so that the structure for assembling the outer blade to the outer blade holder is complicated, and the space for accommodating the tension spring is increased. It is necessary to secure it inside the holder.

  In that respect, the outer blade of Patent Document 3 is provided with a divided face wall (tension spring) surrounding the retaining hole so as to be flush with the face wall of the outer blade, so that the assembly structure of the outer blade to the outer blade holder is simplified. And can save the labor of assembly. The space for accommodating the tension spring can also be minimized. However, since the structure of the tension spring is unique, the spring characteristics required for the tension spring such as the responsivity of the spring and the elastic deformation range of the spring cannot be sufficiently exhibited.

  Specifically, the divided face wall (tension spring) surrounding the retaining hole is formed to be flush with the other face wall of the outer blade, and is divided only at the left and right corners of the front and rear edges of the outer blade. For example, even if a tensile force corresponding to the cutting load is applied to the outer blade, the divided surface wall is not stretched and deformed, so long as no excessive external force is applied. There is no deformation. Moreover, the elastic deformation range from the start of elastic deformation until reaching the elastic limit is very small.

  This means that when an outer blade formed by a precision press method or an outer blade formed by an etching method or an electroforming method is assumed, it is easy to exert elasticity by bending the outer blade in the thickness direction. However, even if a tensile force parallel to the sheet surface is applied to the outer cutter, it will be easily understood that it is extremely difficult to elastically deform the outer cutter. Incidentally, the outer blade formed by the electroforming method is extremely thin compared to the outer blade formed by the precision press method or the etching method, so a part of the outer blade blank is formed after forming the outer blade blank by the electroforming method. Even if the tension spring is bent and formed by pressing, a sufficient spring elasticity cannot be obtained.

  Although the object of the present invention is a tension spring formed flush with the face wall of the outer blade in the unfolded state, the spring characteristics required for the tension spring can be sufficiently exerted. An object of the present invention is to provide an electric razor that simplifies the tension structure and can be easily assembled to the outer blade holder with less effort.

  The electric razor of the present invention includes an outer blade 11 that is held in an inverted U shape by an outer blade holder 12, and an inner blade 9 that is in sliding contact with the inner surface of the outer blade 11. The outer blade 11 is integrally provided with a blade main portion 20 and a pair of front and rear waist walls 21 continuous with the blade main portion 20, and a tension spring that pulls and biases the outer blade 11 against the waist wall 21 of the outer blade 11. 24 is formed integrally. The tension spring 24 is composed of one or more spring elements 30 that are formed flush with the face wall of the outer blade 11 in the deployed state.

  A spring side mounting portion 25 including a retaining hole 26 is formed at the end of the spring element 30 constituting the tension spring 24.

  The spring side mounting portion 25 of the outer blade 11 is continuously formed in a state where the spring elements 30 are bridged.

  The width dimension of each component part of the spring element 30 is set larger than the thickness dimension of the spring element 30.

  A plurality of spring elements 30 and partitioned spaces 31 for partitioning adjacent spring elements 30 are alternately formed on the waist wall 21, and the waist wall 21 and the spring-side mounting portion 25 are interposed only via the spring elements 30. Try to connect.

  The spring element 30 includes an upper support wall 33 that is continuous with the wall 21, a lower support wall 34 that is continuous with the spring-side mounting portion 25, an upper spring arm 35 and a lower spring arm 36 that are continuous with these support walls 33, 34. The arm end wall 37 connecting the side ends of the upper and lower spring arms 35 and 36 and the dissociation slit 38 formed between the upper and lower spring arms 35 and 36.

  Both end portions of the upper spring arm 35 and the lower spring arm 36 are connected by an end wall 37. The upper spring arm 35, the lower spring arm 36, the arm end wall 37, and the dissociation slit 38 are line symmetric with respect to a virtual center connecting the centers of the upper branch wall 33 and the lower branch wall 34 in the width direction. To form.

  In a state where the spring element 30 is tensioned, each of the upper spring arm 35 and the lower spring arm 36 is elastically deformed in opposite directions.

  The bending elastic force of the upper support wall 33 and the bending elastic force of the lower support wall 34 are made different in magnitude. Specifically, the total length c in the vertical direction of the upper support wall 33 is set larger than the total length d in the vertical direction of the lower support wall 34. Further, the width dimension “a” of the upper support wall 33 in the left-right direction is set smaller than the width dimension “b” of the lower support wall 34 in the left-right direction.

  In the present invention, the tension spring 24 for pulling and biasing the outer blade 11 is composed of one or more spring elements 30 that are formed flush with the surface wall of the outer blade 11 in the deployed state. Compared with the case where they are provided as independent parts, the work for assembling the outer blade 11 and the tension spring 24 to the outer blade holder 12 and the like can be simplified, and the cost can be reduced as much as the tension structure can be simplified. Since the spring element 30 is formed flush with the face wall of the outer blade 11, the space for accommodating the tension spring 24 inside the outer blade holder 12 can be minimized. In particular, when the outer blade 11 is formed by electroforming, the spring characteristics of the tension spring 24 can be variously changed by simply changing the shape and arrangement pattern of the spring element 30, and the outer blade 11 and the inner blade 11. The tension spring 24 adapted to the shearing condition by the blade 9 can be easily formed.

  If the spring side mounting portion 25 is formed integrally with the end of the spring element 30, it is not necessary to provide a mounting structure separately from the tension spring 24, and the outer blade 11 and the tension spring 24 are assembled to the outer blade holder 12 and the like accordingly. Can be further simplified, and at the same time, the tension structure can be simplified.

  In the outer blade 11, when the spring side mounting portion 25 is continuously formed in a state of bridging each spring element 30, the protruding ends of adjacent spring elements 30 can be bridged and reinforced by the spring side mounting portion 25, so 11 can prevent a part of each spring element 30 from being damaged or deformed during handling, thereby improving durability. In particular, when the outer cutter 11 is manufactured by the electroforming method, when the outer cutter 11 is peeled off from the mother mold after completion of the electroforming, a part of each spring element 30 is damaged or the spring element 30 is cracked. Can be eliminated, and the yield of the outer blade 11 can be improved. Furthermore, since the spring element 30 can be formed at the same time when the outer blade 11 is formed, variations in positional accuracy and shape accuracy of the tension spring 24 can be eliminated, and variations in tension force in the individual outer blades 11 can be eliminated. When forming the outer blade 11 by electroforming, the thickness of the spring element 30 and the blade main portion 20 can be partially adjusted as necessary, and the function can be improved by making it different from the thickness of other portions. The present invention can be applied to the case where the strengths of the upper and lower support walls 33 and 34 are different from each other.

  When the width dimension of each component part of the spring element 30 is set to be larger than the thickness dimension of the spring element 30, the tension spring 24 that can exhibit sufficient elasticity while securing the strength of each component part of the spring element 30 is obtained. Incidentally, when the width dimension of each component part of the spring element 30 is smaller than the thickness dimension of the spring element 30, the spring element 30 is easily elastically deformed, but is easily damaged and is durable when an impact force or a large external force is applied. There is a problem with sex.

  According to the outer blade 11 that alternately forms a plurality of spring elements 30 on the waist wall 21 and partitioned spaces 31 for partitioning adjacent spring elements 30, the waist wall 21 and the spring-side mounting portion 25 are spring elements. Since it becomes the structure connected only through 30, the external force which acts on the outer blade 11 is made to act directly on each spring element 30, and the spring element 30 can be elastically deformed equally. In addition, the tension can be applied uniformly in the width direction of the blade main portion 20 to improve the sharpness over the entire width direction of the outer blade 11. When the tension spring 24 is formed by a single spring element 30, it is inevitable that the stress of the spring element 30 when an external force acts on the outer blade 11 is concentrated in one place. It is difficult to apply a uniform tension force in the width direction of the blade 11, and it becomes difficult to ensure sharpness over the entire width direction of the outer blade 11.

  Upper and lower support walls 33, 34, upper spring arms 35 and lower spring arms 36 continuous to these support walls 33, 34, arm end walls 37 connecting the side ends of the upper and lower spring arms 35, 36, and upper and lower support walls 33, 34 According to the spring element 30 constituted by the dissociation slit 38 formed between the spring arms 35 and 36, the upper and lower spring arms 35 and 36 are deformed in the thickness direction in opposite directions, so that spring elasticity can be exhibited. Even though it is formed of a thin face wall, a tension spring 24 that can exhibit sufficient spring elasticity and is excellent in durability can be obtained. Since the spring element 30 is formed flush with the surface wall of the outer blade 11, the tension structure can be simplified and the cost can be reduced, and the work for assembling the outer blade 11 and the tension spring 24 to the outer blade holder 12 and the like can be simplified. it can.

  The upper and lower spring arms 35, 36, arm end walls 37, and dissociation slits 38 are formed in line symmetry with a virtual center connecting the centers of the upper and lower support walls 33 and 34 in the width direction as axes of line symmetry. Since the external force acting on the outer blade 11 can be applied equally to each spring element 30, the setting and management of the spring characteristics of the tension spring 24 can be simplified, and the entire surface of the mesh blade portion 20A of the outer blade 11 can be simplified. Can be evenly adhered to the inner blade 9.

When the upper spring arm 35 and the lower spring arm 36 are elastically deformed in opposite directions in a state where the spring element 30 is tensioned, the outer blade 11 is moved using the spring elasticity consisting of a gentle upward straight line. I can be nervous. That is, the outer blade 11 can be tensioned in a deformation region in which the change in spring elasticity is small compared to the change in the amount of deflection deformation, whereby the outer blade 11 can be brought into close contact with the inner blade 9 with a substantially uniform spring elastic force. .

  If the bending elastic force of the upper branch wall 33 and the bending elastic force of the lower branch wall 34 are different from each other, the individual spring elements 30 precede the branch wall and the spring arm on the side where the bending elastic force is small. After the elastic deformation, the other spring arm can be elastically deformed in the opposite direction to equalize the tension force on the outer blade 11. If the bending elastic force of the upper branch wall 33 is set to be smaller than the bending elastic force of the lower branch wall 34, when the external force acts on the outer blade 11, the upper branch wall 33 is elastically deformed in advance, and the lower branch wall 34 can be elastically deformed in the opposite direction. At the same time, the upper support wall 33 is elastically deformed away from the inner wall of the outer blade holder 12 to prevent the upper spring arm 35 from contacting and interfering with the inner wall of the outer blade holder 12, and the tension spring 24 can expand and contract. The operation can be smoothed.

When the overall length c in the vertical direction of the upper support wall 33 is set to be larger than the overall length d in the vertical direction of the lower support wall 34, the upper support wall 33 is easily elastically deformed in the thickness direction as much as the overall length c is larger. Therefore, the upper support wall 33 and the upper spring arm 35 can be elastically deformed prior to the lower support wall 34 and the lower spring arm 36, and the upper support walls 33 and the upper spring arms 35 of all the spring elements 30 are stepped. The upper spring arm 35 is elastically deformed in the direction away from the portion 42, and at the same time, all the lower support walls 34 and the lower spring arms 36 are elastically deformed in the direction opposite to the upper support walls 33 and the upper spring arms 35, so that the upper spring arms 35 are Therefore, it is possible to prevent the tension spring 24 from expanding and contracting smoothly. Incidentally, although rarely, depending on how the assembling operator assembles, the upper support wall 33 and the upper spring arm 35 may be elastically deformed in a direction approaching the stepped portion 42. If 33 is more easily elastically deformed than the lower support wall 34, the upper support wall 33 and the upper spring arm 35 can be more reliably elastically deformed in a direction away from the step portion 42.

  If the width dimension a in the left-right direction of the upper support wall 33 is set smaller than the width dimension b in the left-right direction of the lower support wall 34, the deformation stress of the upper support wall 33 can be reduced by the smaller width dimension a. The wall 33 and the upper spring arm 35 can be elastically deformed prior to the lower support wall 34 and the lower spring arm 36. Thereby, the upper spring arms 35 of all the spring elements 30 can be further elastically deformed in a direction away from the stepped portion 42, and the upper spring arms 35 contact and interfere with the inner wall of the outer blade holder 12. Thus, the expansion and contraction of the tension spring 24 can be further smoothed.

(Example) FIGS. 1-8 shows the Example of the electric shaver provided with the outer blade which concerns on this invention. In FIG. 2, the electric razor includes a main body case 1 formed in a Y shape, and a head portion 2 that is floatably supported by the main body case 1 so as to be vertically movable, tilted forward and backward, and horizontally tiltable. Two secondary batteries 3, a circuit board and a switch (not shown), and the like are arranged inside. On the front surface of the main body case 1, there are arranged a push button type switch button 4 for switching the previous switch, an indicator lamp 5 that lights up when the switch button 4 is turned on, and a charging indicator lamp 6 that lights up when charging. It is.

  The head portion 2 is configured such that an inner blade driving motor 8, an inner blade 9, a gear mechanism 10 that transmits the rotational power of the motor 8 to the inner blade 9, and the like are housed in the head case 7. The outer blade holder 12 for holding the sheet-shaped outer blade 11 in an inverted U shape is detachably mounted on the upper outer surface of the head case 2a. As shown in FIG. 3, the inner blade 9 includes a cylindrical blade shaft 15, an inner blade shaft 16 fixed along the axis of the blade shaft 15, and a spiral shape along the peripheral surface of the blade shaft 15. A group of blades 17 are provided. The inner blade 9 is rotationally driven in the counterclockwise direction as indicated by an arrow, and cuts the beard in cooperation with the outer blade 11.

  As shown in FIG. 1 and FIG. 3, the outer blade 11 integrally has a blade main portion 20 that is curved along the inner blade 9 in use and a pair of front and rear waist walls 21, 21 that are continuous with the blade main portion 20. The fixed side mounting part 23 provided with the five retaining holes 22 is formed along the front edge of the waist wall 21 on the upper side of the rotation, and the tension part 28 continues to the waist wall 21 on the lower side of the rotation. Is provided. A tension spring 24 that pulls and biases the outer blade 11 and a spring-side mounting portion 25 that includes four retaining holes 26 are formed integrally with the waist wall 21 in the tension portion 28. The blade main portion 20 is mainly formed with a mesh blade portion 20A for cutting short hairs, and a slit blade portion 20B for mainly cutting comb hairs and long hairs is formed from the mesh blade portion 20A to the waist wall 21 on the rotating upper side. It is.

  The outer blade 11 is formed by an electroforming method, an etching method, and a precision press method, and when forming the mesh blade portion 20A and the slit blade portion 20B, the fixed side mounting portion 23, the tension spring 24, and the spring side mounting portion 25 are provided. Form at the same time. In the electroforming method, nickel, a nickel-cobalt alloy, or the like is electrodeposited on the surface of the base material, and necessary portions corresponding to the respective members 20A to 25 are formed in the grown electrodeposition layer. Using the inserted stainless steel sheet as a raw material, the unnecessary portions are removed by the corrosive action of the etching solution to form the respective members 20A-25. Similarly, in the precision press method, unnecessary portions are punched and removed to form the respective members 20A to 25. In this embodiment, the outer cutter 11 is described as being formed by electroforming. Although not shown in the figure, the waist walls 21 and 21 are formed with heat radiating holes made of fine holes on one side.

  As shown in FIG. 1, the tension spring 24 includes seven spring elements 30 formed along the edge of the lower wall 21 of the lower rotation side. Each spring element 30 is made independent by dividing | segmenting by the division space 31 hollowed out in the shape of a character. Thereby, the waist wall 21 and the spring side mounting part 25 will be connected through only the seven spring elements 30, and the tensile force acting on the outer blade 11 is caused to act equally on the individual spring elements 30, The spring element 30 can be elastically deformed moderately.

  The spring element 30 includes a pair of upper and lower spring walls 35 and 36 that are elastically deformed in the thickness direction, and is formed flush with the other surface walls of the outer cutter 11. Specifically, an upper support wall 33 that continues to the waist wall 21, a lower support wall 34 that continues to the spring-side mounting portion 25, and an upper spring arm 35 that is formed to project from the support walls 33 and 34 to the left and right. And a lower spring arm 36, a pair of arm end walls 37, 37 that connect both ends of the upper and lower spring arms 35, 36, and a dissociation slit 38 that separates the upper and lower spring arms 35, 36. When an imaginary center connecting the centers of the upper and lower support walls 33 and 34 in the width direction is an axis of line symmetry, the upper spring arm 35 and the lower spring arm 36, both arm end walls 37, and the dissociation slit 38 are Both are formed so as to be line symmetric on the left and right.

  As shown in FIG. 3, the outer blade 11 configured as described above has the left and right horizontally attached mounting pieces 41 and 42 welded and fixed to the fixed side mounting portion 23 and the spring side mounting portion 25, respectively. By receiving 42 with step portions 43 and 44 provided on the inner surfaces of the front and rear walls of the outer blade holder 12, the outer blade holder 12 holds the shape in an inverted U shape. Each of the mounting pieces 41, 42 is formed of a horizontally long strip-shaped plastic molded product, and welding pins 45, 46 corresponding to the respective retaining holes 22, 26 are integrally provided on the respective plate surfaces (see FIG. 5). .

  As shown in FIG. 3, when the outer blade holder 12 is engaged with the head case 2 a, an inverted U-shape is obtained with the inner surface of the outer blade 11 mainly received by the blade 17 of the inner blade 9. In the tension spring 24 in this state, each spring element 30 is elastically deformed, and the outer blade 11 is brought into close contact with the inner blade 9. At this time, since the entire outer cutter 11 is pushed up by the inner cutter 9 and retained in an inverted U shape, each spring element 30 is elastically deformed. Specifically, the upper spring arm 35 is pulled upward and the lower spring arm 36 is pulled downward, so that each spring arm 36 extends and deforms in the opposite direction. As a result, in each spring element 30, the upper support wall 33 and the left and right center portion of the upper spring arm 35 facing the dissociation slit 38 (the portion on the line connecting the left and right centers of the upper support wall 33 and the lower support wall 34) are stepped portions 42. Elastically deforms in a direction away from the lower support wall 34 and at the same time elastically deforms in a direction in which the left and right central portions of the lower spring arm 36 facing the dissociation slit 38 approach the stepped portion 42 to pull and bias the outer blade 11. Yes. Each of the upper branch wall 33 and the lower branch wall 34 bends in a direction intersecting with the deformation direction of the upper spring arm 35 and the lower spring arm 36. That is, the upper and lower support walls 33 and 34 and the upper and lower spring arms 35 and 36 are deformed in different thickness directions to exert elastic force, and when viewed as a whole of the spring element 30, each part is deformed three-dimensionally. Will be. The elastic deformation amount of the spring element 30 at this time is a deformation amount near the center of the free state and the elastic deformation limit as will be described later, and the outer blade 11 is lifted away from the inner blade 9 or the outer blade 11 is When the inner blade 9 is pulled toward the lower side in the rotational direction, the amount of elastic deformation of the upper and lower spring arms 35 and 36 is increased or decreased, so that the outer blade 11 can always be in close contact with the inner blade 9.

  As shown in FIG. 8B, in the case of a general spring such as a wire spring, a leaf spring, or a coil spring, the amount of deformation of the spring is substantially proportional to the spring elasticity, and the change characteristic thereof is an inclined straight line. Can be represented. At this time, the horizontal axis represents the amount of deformation X of the spring, and the vertical axis represents the spring elastic force F. As long as the amount of deformation of the flexure changes, the tension force acting on the outer blade 11 can be made substantially constant as the amount of change in the spring elastic force is small. That is, it is possible to prevent the tension force acting on the outer blade 11 from changing extremely as the inclination angle of the previous change characteristic line becomes gentler.

  In the case of the spring element 30 described above, the upper support wall 33 and the upper spring arm 35 and the lower support wall 34 and the lower spring arm 36 are elastically deformed in opposite directions, respectively, and the upper end portions of the arm end walls 37 and 37 The lower half is elastically deformed so as to be twisted in the opposite direction, and the resultant force becomes the spring elasticity of each spring element 30, and the change characteristic becomes a gentle straight line as shown in FIG. A plurality of spring elements 30 having such characteristics are formed in parallel with the waist wall 21 in an even manner. Therefore, in the state where the outer blade holder 12 is mounted on the head case 2a, the outer blade 11 is moved while preventing the spring elasticity from greatly changing both in the case where the spring element 30 is deformed and contracted. The inner blade 9 can be brought into close contact with a substantially uniform spring elastic force. In the spring element 30 in this embodiment, when the outer blade holder 12 is mounted on the head case 2a, the bending angle of the upper and lower support walls 33 and 33 is about 45 as shown in FIG. Set to degrees. The reason why the change characteristic is a gentle straight line is that the upper support wall 33, the upper spring arm 35, the lower spring arm 36, and the lower support wall 34 are integrally connected in series.

  The difference between the state of the spring element 30 in the free state and the state in which the spring element 30 is elastically deformed is shown in FIGS. 6 (a) and 6 (b) and FIGS. 7 (a) and 7 (b). As shown in FIGS. 6A and 7A, when the spring element 30 is in a free state, the upper and lower spring arms 35 and 36 are flush with the waist wall 21, and at this time The tension spring 24 does not exhibit elastic force. As shown in FIGS. 6B and 7B, when the spring element 30 is elastically deformed, the upper support wall 33 and the upper spring arm 35, and the lower support wall 34 and the lower spring arm 36 are opposite to each other. By elastically deforming, the outer blade 11 is pulled and biased toward the spring side mounting portion 25. At this time, as the upper support wall 33 and the upper spring arm 35 and the lower support wall 34 and the lower spring arm 36 are elastically deformed, the vertical length of the spring element 30 is extended by the dimension E shown in FIG.

  As described above, the spring element 30 exhibits spring elasticity by the upper and lower support walls 33 and 34 and the upper and lower spring arms 35 and 36 being elastically deformed in opposite directions, but is higher than the lower support wall 34. If the support wall 33 is easily bent and deformed, the upper spring arm 35 can be elastically deformed before the lower spring arm 36 is elastically deformed when an external force is applied to the outer blade 11. In addition, when the upper support wall 33 and the upper spring arm 35 are elastically deformed away from the stepped portion 42, the upper spring arm 35 is prevented from contacting and interfering with the inner wall of the outer blade holder 12, and the tension spring. 24 expansion / contraction operations can be smoothed. Therefore, in this embodiment, the dimensional relationship between the upper branch wall 33 and the lower branch wall 34 is set as follows. The upper support wall 33 is set to have a vertical length a that is larger than the vertical length b of the lower support wall 34 to make the upper support wall 33 flexible. The upper support wall 33 is easily bent by being set smaller than the width dimension d of the lower support wall 34 in the left-right direction.

  Specifically, when the thickness of the outer cutter 11 is 55 μm, the previous dimension a is 0.96 mm, the dimension b is 1.06 mm, the dimension c is 0.50 mm, and the dimension d is 0.30 mm. The horizontal width of the upper and lower spring arms 35 and 36 (the horizontal width of the dissociation slit 38) was 4.00 mm, the vertical width of the dissociation slit 38 was 0.150 mm, and the horizontal width of the arm end wall 37 was 5.450 mm.

(Comparative example) The present inventors made several trial manufactures of tension springs having different formation patterns by electroforming prior to the above-described example, and confirmed the spring characteristics of the tension springs. For example, as shown in FIG. 9A, when the outer blade 51 is formed by electroforming, a group of zigzag spring elements 53 are formed at the same time, and the tension spring 52 is configured by these spring elements 53. Further, as shown in FIG. 9B, the tension spring 52 is formed of a group of spring elements 53 including ribs 54 intersecting vertically and horizontally and rings 55 formed at regular intervals along the longitudinal ribs 54. Configured. In this case, when the outer blade 51 is peeled off from the matrix after the electroforming is completed, the spring elements 53 are not partially damaged or cracked in the spring elements 5. The outer side of the spring element 53 is connected by a connecting wall 57.

  However, no matter how the formation pattern of the spring element 53 is changed, the tension spring 52 that can exhibit sufficient elasticity cannot be obtained. As a result of further trial and error, it has been found that the fact that the outer sides of the spring elements 53 positioned at both ends are connected and restrained by the connecting wall 57 is a factor that cannot exert sufficient elasticity. That is, when the connecting wall 57 is removed, the external force directly acts on the spring element 53, so that the spring element 53 is easily elastically deformed. As a result of such trial and error, it was confirmed that the spring structure described in the above embodiment is suitable.

  FIG. 10 shows another embodiment of the outer blade 11. The spring element 30 is composed of upper and lower support walls 33 and 34, a pair of upper and lower spring arms 35 and 36, both arm end walls 37 and 37, a dissociation slit 38, etc. A spring side mounting portion 25 having a hooking hole 26 is provided continuously to the lower end. That is, the spring-side mounting portion 25 in an independent state is provided for each spring element 30. In this case, by attaching the attachment piece 42 to the outer blade 11, each spring-side attachment portion 25 is integrated via the attachment piece 42. In addition, the spring side mounting part 25 can be formed to project from the left and right sides of the lower support wall 34 as necessary, and a plurality of retaining holes 26 can be provided. Since others are the same as the previous embodiment, the same reference numerals are assigned to the same members, and descriptions thereof are omitted.

  In the previous embodiment, the upper spring arm 35 and the lower spring arm 36 are formed so as to project on both sides of the upper and lower support walls 33 and 34, but this is not necessary, and as shown in FIG. The spring arm 36 can be formed to protrude only on one side of the upper and lower support walls 33, 34, and the protrusion of both the spring arms 35, 36 can be connected by the arm end wall 37 to form the spring element 30. One end of the dissociation slit 38 communicates with the partitioned space 31 at the side end edge of the both proximal ends of the spring arms 35 and 36. In this case, the section space 31 has a horizontally long U shape.

  In the above-described embodiment, the upper spring arms 35 are elastically deformed in a specific direction by making the bending elasticity of the upper and lower support walls 33 and 34 different, but this is not necessary. For example, the upper spring arm 35 and the lower spring arm 36 in the free state can be realized in advance in the direction in which they are desired to be elastically deformed. Further, in a state where the outer blade 11 is assembled to the outer blade holder 12, each spring element 30 is elastically deformed, and therefore, the upper spring arm 35 and the lower spring arm 36 are moved in a specific direction using a jig at the time of assembly. It can be elastically deformed. Further, if a pin for forcibly pushing the upper spring arm 35 away from the step portion 42 is provided on the inner surface of the outer blade holder 12 facing the upper spring arm 35, the outer blade 11 is simply attached to the outer blade holder 12. The upper spring arm 35 can be elastically deformed in a direction away from the step portion 42 simply by assembling.

  In addition to the above embodiment, the upper support wall 33 and the upper spring arm 35, and the lower support wall 34 and the lower spring arm 36 are formed in a Y shape in addition to being formed in a T shape. The shape can be a long rhombus. In the above embodiment, the electric razor provided with the rotary inner blade 9 has been described. However, the outer blade 11 according to the present invention can also be applied to a reciprocating electric razor. In that case, the tension spring 24 can be provided in each of the front and rear waist walls 21.

It is an expansion | deployment top view of an outer blade. It is a front view of an electric razor. It is a vertical side view of a head part. It is a disassembled front view of the state which separated the outer blade and the outer blade holder. It is a disassembled perspective view of an outer blade. It is a perspective view which shows the elastic deformation state of a spring element. It is sectional drawing which shows the elastic deformation state of a spring element. It is a characteristic view which shows the difference of the characteristic of the conventional spring and the tension spring which concerns on this invention. It is a principal part top view of the tension spring prototyped prior to this invention. It is an expansion | deployment top view of only the principal part which shows another Example of a tension spring. It is an expansion | deployment top view of only the principal part which shows another Example of a tension spring.

Explanation of symbols

9 inner blade 11 outer blade 22 retaining hole 23 fixed mounting portion 24 tension spring 25 spring side mounting portion 30 spring element 31 section space 33 upper support wall 34 lower support wall 35 upper spring arm 36 lower spring arm 37 arm end wall 38 dissociation slit

Claims (11)

An outer blade (11) that is held in an inverted U shape by the outer blade holder (12), and an inner blade (9) that is in sliding contact with the inner surface of the outer blade (11),
The outer blade (11) is integrally provided with a blade main portion (20) and a pair of front and rear waist walls (21) continuous to the blade main portion (20), and the outer wall (21) of the outer blade (11). In addition, a tension spring (24) that pulls and biases the outer blade (11) is integrally formed,
An electric razor in which the tension spring (24) is composed of one or more spring elements (30) formed flush with the face wall of the outer blade (11) in the deployed state.   The electric razor according to claim 1, wherein a spring side mounting portion (25) including a retaining hole (26) is formed at an end portion of a spring element (30) constituting the tension spring (24).   The electric shaver according to claim 2, wherein the spring side mounting portion (25) of the outer blade (11) is continuously formed in a state of bridging each spring element (30).   The electric shaver according to claim 2 or 3, wherein the width dimension of each component part of the spring element (30) is set larger than the thickness dimension of the spring element (30). A plurality of spring elements (30) and partitioned spaces (31) for partitioning adjacent spring elements (30) are alternately formed on the waist wall (21),
The electric shaver according to claim 3 or 4, wherein the waist wall (21) and the spring-side mounting portion (25) are connected only through the spring element (30).   The spring element (30) has an upper branch wall (33) continuous with the waist wall (21), a lower branch wall (34) continuous with the spring side mounting portion (25), and these branch walls (33, 34). An upper spring arm (35) and a lower spring arm (36) continuous to each other, an arm end wall (37) connecting the side ends of the upper and lower spring arms (35, 36), and an upper spring arm (35, 36) The electric shaver according to any one of claims 3 to 5, comprising a dissociation slit (38) formed therebetween. Each of both ends of the upper spring arm (35) and the lower spring arm (36) are connected by an arm end wall (37),
The upper spring arm (35), the lower spring arm (36), and the arm end wall (37) with the virtual center connecting the centers in the width direction of the upper branch wall (33) and the lower branch wall (34) as line symmetry axes. And the dissociation slit (38) are symmetrically formed.   The electric razor according to 6 or 7, wherein each of the upper spring arm (35) and the lower spring arm (36) is elastically deformed in opposite directions in a state where the spring element (30) is in tension.   The electric shaver according to claim 6, 7 or 8, wherein the bending elastic force of the upper branch wall (33) and the bending elastic force of the lower branch wall (34) are made different in size.   The electric razor according to any one of claims 6 to 9, wherein the total length (c) in the vertical direction of the upper branch wall (33) is set larger than the total length (d) in the vertical direction of the lower branch wall (34).   The electrical width according to any one of claims 6 to 10, wherein a width dimension (a) in the left-right direction of the upper support wall (33) is set smaller than a width dimension (b) in the left-right direction of the lower support wall (34). Razor.

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