JP6499517B2 - Electric razor - Google Patents

Description

  The present invention relates to an electric razor having a vibration generating structure for vibrating a rotationally driven cutting blade.

  This type of electric shaver is known, for example, from Patent Document 1 according to the proposal of the present applicant. There, a vibration generating mechanism is constituted by hemispherical minute protrusions provided on both side surfaces of the rotary inner blade and guide pins provided on a bearing wall facing the minute protrusions. The microprotrusions are arranged at regular intervals in the circumferential direction. When one microprotrusion gets over the corresponding guide pin, the inner blade moves to the right away from the guide pin, and the other microprotrusion is the corresponding guide pin. When moving over, the inner blade moves to the left in the direction away from the guide pin. In this way, the inner blade is moved left and right while being driven to rotate, thereby causing the inner blade to exert a cutting action and improving the sharpness.

JP 2006-81710 A (paragraph number 0027, FIG. 1)

  In the electric razor of Patent Document 1, a rotating microprojection is relatively pushed out by a guide pin, and the inner blade is mechanically and forcibly moved left and right. In such a vibration generating mechanism, a large frictional resistance is generated between the minute projections and the guide pins, so that the guide pins and the minute projections are easily worn relatively early. Further, as the guide pin and the minute projections are worn, the moving stroke of the inner blade in the left-right direction is gradually reduced, and the trimming effect tends to be weakened. Compared to an electric razor that does not have an oscillating mechanism, the amount of power consumption increases by the rotational resistance of the oscillating mechanism, and there is also a problem in which a tapping sound is generated continuously when a microprojection collides with a guide pin. .

An object of the present invention is to provide an electric razor that can reciprocate a cutting blade by reducing the friction and effectively perform whisker cutting, and can accurately reciprocate the cutting blade even during long-term use. There is.
An object of the present invention is to provide an electric razor that can reciprocate a cutting blade with a simpler structure than a conventional vibration generating structure, and thus can reduce the cost despite having a cutting function. There is.

  The electric razor according to the present invention transmits the rotational power of the motor 10 to the cutting blade 9 provided on the razor head 2 via the final gear pair. As shown in FIG. 1, the final gear pair includes a final gear 19 connected to the cutting blade shaft 9 a of the cutting blade 9 and a drive gear 18 that meshes with the final gear 19. A thrust drive structure is provided at the meshing portion of the drive gear 18 and the final gear 19 to apply a thrust force in the direction of the rotation center axis to the final gear 19. The cutting blade 9 is reciprocated by a thrust drive structure while being rotationally driven by a drive gear 18.

  The thrust drive structure includes a forward tooth surface 22 and a reverse tooth surface 23 provided on the gear teeth 20 of the drive gear 18 and / or the gear teeth 21 of the final gear 19. At the time of power transmission of the forward tooth surface 22, the final gear 19 is forwardly displaced by a thrust force generated between both gear teeth 20 and 21. Further, at the time of power transmission of the backward tooth surface 23, the forwardly displaced final gear 19 is backwardly moved in the direction opposite to the forward displacement direction by the thrust force generated between the gear teeth 20 and 21.

  The forward tooth surface 22 and the backward tooth surface 23 are inclined in opposite directions, and forward displacement and backward displacement are positively performed.

  The number of forward tooth surfaces 22 and the number of backward tooth surfaces 23 formed on the gear teeth 20 of the drive gear 18 and / or the gear teeth 21 of the final gear 19 are set to the same number.

  At least two sets of forward tooth surfaces 22 and reverse tooth surfaces 23 are provided on the gear teeth 20 of the drive gear 18 and / or the gear teeth 21 of the final gear 19, and the cutting blade 9 is rotated when the final gear 19 makes one rotation. Is reciprocated twice or more.

  The thrust drive structure includes a spur gear and a tooth inclination gear in which the tooth center axis P of the gear teeth 31 is inclined with respect to the rotation center axis. One of the drive gear 18 and the final gear 19 is formed by a spur gear, and the other is formed by a tooth inclination gear.

  The tooth width B1 of the drive gear 18 or the final gear 19 formed by a spur gear is set to be larger than the rotation area width B3 in the axial direction of the drive gear 18 or the final gear 19 formed by a tooth inclination gear.

  The pressurizing tooth surface 32 of the dentition inclined gear is formed by an outwardly curved surface.

  The inclination angle θ of the dentition center axis P exceeds 0 degree and is less than 45 degrees.

  In the electric shaver according to the present invention, a thrust drive structure is provided at the meshing portion of the drive gear 18 and the final gear 19, and the thrust force in the direction of the rotation center axis is applied to the final gear 19 to rotate the cutting blade 9. It can be reciprocated while driving. According to such an electric razor, the cutting blade 9 can be driven to reciprocate in a constantly stable state, and the cutting action can be exhibited, so that the beard cutting can be performed effectively. Further, since the thrust force is generated by utilizing the meshing operation of the drive gear 18 and the final gear 19, the thrust drive structure can be simplified as compared with the conventional vibration generating mechanism. Although it is a razor, the cost required for its manufacture can be reduced.

  According to the thrust drive structure composed of the forward tooth surface 22 and the reverse tooth surface 23 provided on the gear teeth 20 and 21 of the drive gear 18 and / or the final gear 19, the final gear is transmitted during the power transmission of the forward tooth surface 22. The forward gear 19 can be moved forward while being driven to rotate, and the final gear 19 can be driven to move backward while the drive gear 23 is being driven. Specifically, the final gear 19 is displaced forward by the thrust force generated by the driving force component on the forward tooth surface 22 of the gear teeth 20 and 21, and the final gear is generated by the thrust force generated by the driving force component on the return tooth surface 23. 19 can be moved backward. In this way, when the final gear 19 is displaced forward or backward using the meshing operation of the forward tooth surface 22 and the backward tooth surface 23, the friction is different from the conventional vibration generating mechanism. The cutting blade 9 can reciprocate while reducing. Furthermore, since the final gear 19 is reciprocally displaced by utilizing the meshing operation of the forward tooth surface 22 and the backward tooth surface 23, the gear teeth 20 and 21 are prevented from being worn out at an early stage, and can be used even for long-term use. The cutting blade 9 can be reciprocated accurately, and the cutting effect of the cutting blade 9 can be maintained.

  When the forward tooth surface 22 and the backward tooth surface 23 are inclined in directions opposite to each other and the forward movement and the backward movement are positively performed, the final gear 19 and the cutting blade 9 are made smooth and mechanical. It can be forcibly reciprocated. Along with this, the final gear 19 and the cutting blade 9 can always be forced to reciprocate with a constant reciprocating stroke, so that the cutting action by the cutting blade 9 can be exerted more accurately and the sharpness at the time of cutting the beard can be improved.

  When the number of forward tooth surfaces 22 and the number of backward tooth surfaces 23 formed on the gear teeth 20 and 21 are set to the same number, the number of forward movements and the number of backward movements when the cutting blade 9 makes one rotation are made the same number, The drawing action can be exhibited an integer number of times. Further, when the interval between the forward displacement and the backward displacement is set at an equal interval, the load variation acting on the motor 10 can be made periodic, and the final gear 19 and the cutting blade 9 can be driven back and forth more smoothly. .

  If at least two pairs of forward tooth surfaces 22 and backward tooth surfaces 23 are provided on the gear teeth 20 and 21, the cutting blade 9 can reciprocate twice or more when the final gear 19 makes one rotation. The cutting effect by can be improved and beard cutting can be performed efficiently. For example, when the driving rotation speed of the cutting blade 9 is several thousand rpm, the cutting blade 9 can perform cutting for the number of times more than twice, thereby effectively cutting the whiskers.

  When a thrust drive structure is constituted by a spur gear and a tooth inclination gear, and either the drive gear 18 or the final gear 19 is formed by a spur gear and the other is formed by a tooth inclination gear, the tooth inclination gear rotates halfway. Each time the cutting blade 9 can be driven to reciprocate by generating a thrust force in the opposite direction. In a state where the dentition inclination gear rotates once, the contact position between the pressure tooth surface and the pressure receiving tooth surface changes continuously, and each time the dentition inclination gear rotates halfway, the dentition center axis P of the gear teeth 31 is obtained. Thus, the forward and reverse thrust forces act on the final gear 19. As described above, when the final gear 19 is displaced forward or backward using the meshing operation of the spur gear and the tooth inclination gear, the thrust drive structure is simplified compared to the conventional vibration generating mechanism. Therefore, although it is an electric razor provided with a drawing function, the cost required for its manufacture can be reduced. Furthermore, since the end gear 19 is reciprocally displaced by utilizing the meshing operation of the spur gear and the tooth inclination gear, the gear teeth 20 and 21 are prevented from being worn out at an early stage, and the cutting blade can be accurately cut even during long-term use. 9 can be reciprocated to maintain the cutting effect of the cutting blade 9.

  If the tooth width B1 of the drive gear 18 or the final gear 19 formed by the spur gear is set larger than the rotation region width B3 in the axial direction of the drive gear 18 or the final gear 19 formed by the tooth inclination gear, the spur gear and the tooth The meshing amounts of the row tilt gears are always equalized, and the rotational power of the drive gear 18 can be transmitted to the final gear 19 without variation.

  For example, when the gear teeth of the tooth inclination gear are the drive gear 18 and the gear tooth profile of the drive gear 18 is simply formed as an involute tooth profile, the gear teeth of the drive gear 18 are inclined in the right and left directions. The front end or the rear end of the tooth 31 contacts the pressure receiving tooth surface of the final gear 31. Further, the driving reaction force concentrates on the front end or the rear end of the gear teeth 31 and is easily worn away, and the transmission efficiency is lowered. However, if the pressure tooth surface 32 of the dentition inclined gear is formed as an externally curved surface, the contact position between the pressure tooth surface and the pressure receiving tooth surface is the longitudinal direction along the externally curved surface. Therefore, it is possible to eliminate the concentrated action of the driving load and the driving reaction force on the front end or the rear end of the gear tooth 31. Therefore, the rotational power can be efficiently transmitted from the drive gear 18 to the final gear 19 while eliminating the wear of the front end or the rear end of the gear teeth 31.

  The inclination angle θ of the dentition center axis P exceeds 0 degree and is less than 45 degrees because a thrust force cannot be generated when the inclination angle θ is 0 degree. Also, as the inclination angle θ approaches 45 degrees, a large thrust reaction force acts on the gear teeth 20 of the drive gear 18 and wears easily.

It is a side view which shows the last stage gear pair which concerns on Example 1 of this invention. 1 is a front view of an electric razor according to Embodiment 1. FIG. It is a front view which shows the power transmission structure of the electric shaver which concerns on Example 1. FIG. It is the sectional view on the AA line in FIG. It is an expanded view which shows the arrangement | positioning pattern and thrust direction of a forward tooth surface and a backward tooth surface in a last stage gear pair. It is the front view of the last stage gear pair which concerns on Example 2 of this invention, and the side view of a last stage gear pair. It is an expanded view which shows the arrangement pattern of the forward tooth surface and the backward tooth surface which concern on Example 3 to Example 8. FIG. It is an expanded view which shows the arrangement pattern of the forward tooth surface and the backward tooth surface which concern on Example 9 to Example 13. FIG. It is a front view which shows the power transmission structure and final stage gear pair which concern on Example 14. It is the BB sectional view taken on the line in FIG. It is a front view which shows the state which the drive end gear which concerns on Example 14 rotated. It is CC sectional view taken on the line in FIG. It is a front view which shows schematic structure of the electric shaver which concerns on Example 15. FIG. It is a front view which shows schematic structure of the electric shaver which concerns on Example 16. FIG.

  1 to 5 show Embodiment 1 of an electric shaver according to the present invention. In the present invention, front / rear, left / right, and upper / lower refer to the cross arrows shown in FIG. 2 and the character display indicating the direction. In FIG. 2, the electric razor includes a main body case 1 also serving as a grip, and a razor head 2 provided on the upper portion of the main body case 1. The main body case 1 accommodates a secondary battery (battery) 3, a control board (not shown), and the like, and a switch knob 4 is provided on the front surface of the case.

  The razor head 2 is provided with a head case 5 and an outer blade unit 8 to be attached to the case 5, and a cutting blade (inner blade) 9, a motor 10, and a motor 10 are provided inside these both 5 and 8. Is provided with a transmission structure for transmitting the rotational power to the cutting blade 9. The cutting blade 9 is driven to rotate about a horizontal axis (horizontal axis) and performs whisker cutting by a rotational shearing action in cooperation with the outer blade 12 fixed to the outer blade unit 8. Since the head case 5 is floatingly supported by a float spring (not shown), the entire razor head 2 can tilt with respect to the main body case 1 in the front-rear, left-right, up-down, and diagonal directions. The outer blade unit 8 includes a cap-shaped outer blade holder 11 and a mesh blade-shaped outer blade 12 attached to the outer blade holder 11. The outer blade 12 is held in an inverted U shape by the outer blade holder 11. is there. The outer blade holder 11 is detachably mounted on the head case 5 and is fixed so as not to be separated by a lock structure (not shown). The cutting blade 9 includes a cutting blade shaft 9a, a plurality of disks fixed to the coaxial 9a, and a mesh-shaped cutting blade 9b fixed around the disk. The blade surface of the cutting blade 9b is inclined with respect to the rotation center axis of the cutting blade shaft 9a. The cutting blade shaft 9 a of the cutting blade 9 is rotatably supported by a reverse portal type inner blade holder 13.

  In order to perform a whisker cutting by a pulling action at the time of whisker cutting by the rotational shearing action of the cutting blade 9 and the outer blade 12, a thrust drive structure is configured using the previous transmission structure, and the cutting blade 9 is used as a rotation center axis. It can be reciprocated along. In FIG. 3, the transmission structure is disposed between the first gear 15 fixed to the output shaft of the motor 10, the final gear 19 fixed to the cutting blade shaft 9 a, and the first gear 15 and the final gear 19. The gears 16, 17, and 18 are configured. The thrust drive structure is composed of a final gear pair consisting of a final gear 19 and a drive gear 18 meshing with the gear 19 in the previous gear train. A rotational force and a thrust force in the direction of the rotation center axis are applied to the cutting blade 9 to reciprocate while the cutting blade 9 is driven to rotate. The first gear 15 to the third gear 17 and the drive gear 18 are each formed of a normal spur gear. The final gear 19 is basically a spur gear. However, as shown in FIG. 1, the forward tooth surface 22 and the reverse tooth surface 23 are formed on the pressure receiving tooth surface side of each gear tooth 21. Is different.

  Specifically, as shown in the developed view of FIG. 5A, the forward tooth surface 22 and the backward tooth surface 23 are alternately formed on the pressure receiving tooth surface side of the adjacent gear tooth 21 while being inclined in opposite directions. It is. Therefore, in the state where the forward tooth surface 22 is driven by the drive gear 18, the thrust gear is generated by a component of the driving force applied from the drive gear 18 to the final gear 19, and the final gear 19 is directed leftward as indicated by an arrow in FIG. Displaces forward. Further, in a state in which the return tooth surface 23 is driven by the drive gear 18, it is moved backward in the right direction by the thrust force generated by the component force of the driving force acting on the return tooth surface 23. Thus, the final gear 19 is positively displaced in the forward movement direction and the backward movement direction to reciprocate the cutting blade 9. FIG. 5B shows a change in the direction of the thrust force received by the final gear 19 when the final gear 19 makes one revolution. In order to prevent the gear teeth 20 of the drive gear 18 from protruding from the side edges of the gear teeth 21 of the final gear 19 when the final gear 19 is reciprocally displaced, the tooth width B1 of the gear teeth 21 of the final gear 19 is It is set larger than the tooth width B2 of the 18 gear teeth 20.

  As described above, when the final gear 19 is reciprocated, the cutting edge 9b of the cutting blade 9 that reciprocates while rotating can be cut to improve the sharpness when performing whisker cutting. Further, since the cutting blade 9 is positively reciprocated by the thrust force generated when the final gear 19 is driven by the drive gear 18, unlike the conventional vibration generating mechanism, the forward movement formed on each gear tooth 21. It is possible to eliminate the early wear of the tooth surface 22, the return tooth surface 23, or the tooth surface of the gear tooth 20. Accordingly, even when the electric razor is used for a long period of time, the cutting blade 9 can be accurately reciprocated to maintain the cutting effect.

  Further, since the forward tooth surface 22 and the backward tooth surface 23 are formed on the gear tooth 21 and the cutting blade 9 is reciprocated, the pulling action is achieved with a simpler structure than the conventional vibration generating mechanism. It is possible to reduce the cost required for the manufacture of the electric razor having a pulling function. In addition, since the forward displacement and the backward displacement can be positively performed and the cutting effect can be reliably exhibited, the whiskers can be cut efficiently. In this embodiment, the number of teeth of the final gear 19 is 10, and five forward tooth surfaces 22 and five backward tooth surfaces 23 are provided alternately. Therefore, the cutting blade 9 is rotated five times while the cutting blade 9 rotates once. Can reciprocate.

  FIG. 6 shows an electric razor according to the second embodiment. Here, the first gear 15 to the third gear 17 in the first embodiment are omitted, and the rotational power of the motor 10 is transmitted to the drive gear 18 of the final gear pair with a wound transmission structure. The winding transmission structure includes a timing pulley 26 fixed to the output shaft of the motor 10, a timing pulley 27 fixed to the gear shaft of the drive gear 18, and a timing belt 28 wound around these pulleys 26 and 27. Further, in this embodiment, the final gear 19 constituting the final gear pair is formed by a normal spur gear, and the forward tooth surface 22 and the reverse tooth surface 23 are formed on each gear tooth 20 of the drive gear 18. A thrust drive structure was adopted. The forward tooth surface 22 and the backward tooth surface 23 were alternately formed on the pressure tooth surface side of the adjacent gear tooth 20 so as to incline in opposite directions. Since others are the same as those of the first embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted. As can be understood from this embodiment, the forward tooth surface 22 and the backward tooth surface 23 may be provided on either the drive gear 18 or the final gear 19 constituting the final gear pair. However, if necessary, the forward tooth surface 22 and the backward tooth surface 23 can be formed on both the drive gear 18 and the final gear 19 in a helical gear shape.

The arrangement pattern of the forward tooth surface 22 and the backward tooth surface 23 can be variously changed as shown in FIGS. 7 (a) to 7 (f). In FIG. 7A to FIG. 7F, the return tooth surface 23 or the forward tooth surface 22 is formed on all of the ten gear teeth 21 (or the gear teeth 20).
In FIG. 7A according to the third embodiment, the return tooth surface 23 is formed on the adjacent five gear teeth 21 (or gear teeth 20) among the ten gear teeth 21 (or gear teeth 20). The forward tooth surface 22 was formed on the remaining five gear teeth 21 (or gear teeth 20). According to this tooth surface arrangement pattern, the cutting blade 9 can reciprocate once each time the final gear 19 makes one rotation. Thus, when the same number of forward tooth surfaces 22 and backward tooth surfaces 23 are provided, the cutting blade 9 can reciprocate once when the final gear 19 makes one rotation.
In FIG. 7B according to the fourth embodiment, the return tooth surface 23 and the forward tooth surface 22 are alternately formed for every two gear teeth 21 (or gear teeth 20). According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 can be reciprocated twice by alternately displacing it three times in the backward movement direction and twice in the forward movement direction.

In FIG. 7C according to the fifth embodiment, a return tooth surface 23 is formed on two adjacent gear teeth 21 (or gear teeth 20), and the remaining eight gear teeth 21 (or gear teeth 20) are formed. The forward tooth surface 22 and the backward tooth surface 23 were alternately formed. According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 can reciprocate four times.
In FIG. 7D according to the sixth embodiment, the return tooth surface 23 is formed on the four adjacent gear teeth 21 (or gear teeth 20), and the remaining six gear teeth 21 (or gear teeth 20) are formed. A forward tooth surface 22 was formed. According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 can be reciprocated once. However, the rest time at the forward displacement position is reduced by the number of forward tooth surfaces 22. Slightly longer than the rest time at the dynamic displacement position.

In FIG. 7E according to the seventh embodiment, a return tooth surface 23 is formed on the first, second, sixth, ninth, tenth gear teeth 21 (or gear teeth 20). The forward tooth surfaces 22 were formed on the third to fifth, and seventh and eighth gear teeth 21 (or gear teeth 20). According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 can be reciprocated twice, and the reciprocation interval becomes irregular.
In FIG. 7F according to the eighth embodiment, a return tooth surface 23 is formed on the first, second, sixth, and seventh gear teeth 21 (or gear teeth 20), and the third one. Forward tooth surfaces 22 were formed on the fifth and eighth and tenth gear teeth 21 (or gear teeth 20). That is, two adjacent return tooth surfaces 23 and three adjacent forward tooth surfaces 22 were alternately formed. According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 can be reciprocated twice, and the reciprocation interval becomes irregular.

The arrangement pattern of the forward tooth surface 22 and the backward tooth surface 23 can be variously changed as shown in FIGS. 8 (a) to 8 (e). 8A to 8E, the return tooth surface 23 or the forward tooth surface 22 is formed only on a part of the ten gear teeth 21 (or the gear teeth 20).
In FIG. 8A according to the ninth embodiment, the return tooth surface 23 is formed on the odd-numbered gear teeth 21 (or the gear teeth 20), and the even-numbered gear teeth 21 (or the gear teeth 20) are Formed as normal gear teeth. In the case of this tooth surface arrangement pattern, the cutting blade 9 or the final gear 19 pushed by the return tooth surface 23 collides with the bearing portion of the inner blade holder 13 and slightly returns in the forward direction by the collision reaction force. The final gear 19 moves again in the backward movement direction on the backward movement tooth surface 23 to reciprocate the cutting blade 9. The cutting blade 9 reciprocates five times when the final gear 19 makes one rotation. Alternatively, the cutting gear 9 may be reciprocated by urging the final gear 19 and the cutting blade 9 toward the forward displacement position with a spring.
In FIG. 8B according to the tenth embodiment, the return tooth surface 23 is formed on the first, fifth, and ninth gear teeth 21 (or the gear teeth 20), and the third and seventh teeth. The forward tooth surface 22 was formed on the gear tooth 21 (or gear tooth 20). The remaining gear teeth 21 (or gear teeth 20) were formed as normal gear teeth. According to this tooth surface arrangement pattern, when the final gear 19 makes one revolution, the cutting blade 9 can be reciprocated twice and a half.

In FIG. 8C according to the eleventh embodiment, a return tooth surface 23 is formed on the first gear tooth 21 (or gear tooth 20), and the sixth gear tooth 21 (or gear tooth 20) is moved forward. A moving tooth surface 22 was formed. The remaining gear teeth 21 (or gear teeth 20) were formed as normal gear teeth. According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 can be reciprocated only once, but the forward displacement and the backward displacement are performed at equal intervals.
In FIG. 8D according to the twelfth embodiment, a return tooth surface 23 is formed on the first gear tooth 21 (or gear tooth 20), and the second gear tooth 21 (or gear tooth 20) is moved forward. A moving tooth surface 22 was formed. The remaining gear teeth 21 (or gear teeth 20) were formed as normal gear teeth. According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 can be reciprocated only once, but the time to pause at the forward displacement position is long.

  In FIG. 8E according to the thirteenth embodiment, a return tooth surface 23 is formed on the first and third gear teeth 21 (or the gear teeth 20), and the second and fourth gear teeth 21 are formed. The forward tooth surface 22 was formed on (or the gear tooth 20). The remaining gear teeth 21 (or gear teeth 20) were formed as normal gear teeth. According to this tooth surface arrangement pattern, when the final gear 19 makes one rotation, the cutting blade 9 reciprocates twice and then stops at the forward displacement position.

  9 to 12 show an electric shaver according to the fourteenth embodiment. Here, as in the first embodiment, the rotational power of the motor 10 is transmitted to the final gear pair by the first gear 15, the second gear 16, and the third gear 17, so that the cutting blade 9 is driven to rotate. I made it. In this embodiment, as shown in FIG. 9, a driving gear 18 composed of a tooth inclination gear and a final gear 19 composed of a spur gear constitute a final gear pair to form a thrust driving structure. As shown in FIG. 9, in the dentition inclination gear, the dentition center axis P of the gear teeth 31 of the drive gear 18 is inclined with respect to the rotation center axis, and the pressure tooth surface 32 is as shown in FIG. It is formed with an outwardly projecting curved surface. According to such a thrust drive structure, when the final gear 19 is driven by the drive gear 18, the cutting blade 9 can be driven to reciprocate by generating a reverse thrust force every time the drive gear 18 rotates halfway. The inclination angle θ of the dentition center axis P is preferably greater than 0 degrees and less than 45 degrees. In this embodiment, the inclination angle θ is 20 degrees. If the inclination angle θ is 0 degree, a thrust force cannot be generated. Further, as the inclination angle θ approaches 45 degrees, a large thrust reaction force acts on the gear teeth 31 of the drive gear 18 and is easily worn away.

  In the drive gear 18 composed of a tooth inclination gear, the position at which the individual gear teeth 31 and the gear teeth 21 of the final gear 19 mesh with each other always changes. Therefore, every time the drive gear 18 makes a half rotation, the posture of the tooth row of the gear teeth 31 changes between a state indicated by a solid line and a state indicated by an imaginary line in FIG. Further, when the posture of the tooth row of the gear teeth 31 changes from the state indicated by the solid line to the state indicated by the imaginary line, the final gear 19 undergoes forward displacement in response to the thrust force in the forward movement direction. On the other hand, when the posture of the dentition of the gear teeth 31 changes from the state indicated by the imaginary line to the state indicated by the solid line, the final gear 19 receives the thrust force in the backward movement direction and moves backward. Therefore, the cutting blade 9 can reciprocate only once while the final gear 19 makes one rotation, whereby when cutting the beard by performing cutting with the cutting blade 9b of the cutting blade 9 reciprocating while rotating. Can improve the sharpness.

  As described above, the amount of engagement between the gear teeth 31 of the drive gear 18 and the gear teeth 21 of the final gear 19 is determined in both cases where the tooth row of the drive gear 18 is tilted to the left and tilted to the right. In order to equalize, the tooth width B1 of the final gear 19 is set larger than the rotation area width B3 of the tooth row of the drive gear 18. For the same reason, the tooth width of the third gear 17 is the same as the tooth width B1 of the final gear 19. Further, when the drive gear 18 is simply formed in an involute tooth profile, the front end or the rear end of the gear tooth 31 is in contact with the pressure receiving tooth surface of the final gear 31 when the tooth row of the drive gear 18 is tilted left and right. Accordingly, the driving reaction force concentrates on the front end or the rear end of the gear teeth 31 and is easily worn away, and the transmission efficiency is lowered. In order to solve such problems peculiar to the dentition inclination gear, the pressing tooth surface 32 of the dentition inclination gear is formed by a protruding curved surface, and the contact position between the pressing tooth surface and the pressure receiving tooth surface Is changed in the front-rear direction along the protruding curved surface to eliminate the concentrated action of the driving load and the driving reaction force on the front end or the rear end of the gear teeth 31. Accordingly, the rotational power can be efficiently transmitted from the drive gear 18 to the final gear 19 while eliminating the wear of the front end or the rear end of the gear teeth 31.

  FIG. 13 shows a fifteenth embodiment in which the thrust driving structure according to the present invention is applied to an electric razor in which a cutting blade (inner blade) 9 is driven to rotate about a vertical axis (vertical axis). There, the rotational power of the motor 10 is transmitted to the drive gear 18 of the final gear pair by the first gear 15 and the second gear 16, and the forward tooth surface 22 and the pressure receiving tooth surface of the gear tooth 21 of the final gear 19. The return tooth surface 23 is alternately formed to form a thrust drive structure. According to this thrust drive structure, the cutting blade 9 can reciprocate a plurality of times while the final gear 19 makes one rotation, and the cutting blade 9 can hit the skin surface via the outer blade 12. By striking the skin surface with the outer blade 12, the comb hair and the beard falling on the skin surface can be moved and introduced into the blade hole of the outer blade 12, so that the beard cutting with the cutting blade 9 can be performed effectively.

  FIG. 14 shows an embodiment 16 in which the thrust drive structure according to the present invention is applied to an electric razor in which a cutting blade (inner blade) 9 is driven to rotate about a vertical axis (vertical axis). There, the rotational power of the motor 10 was transmitted to the drive gear 18 of the final gear pair by the first gear 15, the second gear 16, the third gear 17 and the fourth gear 34. A thrust gear is constituted by a drive gear 18 composed of an inclining gear and an end gear 19 composed of a spur gear, in which the tooth center axis P of the gear teeth 31 is inclined with respect to the rotation center axis. A drive structure was adopted. According to this thrust drive structure, similarly to the thrust drive structure described in the fourteenth embodiment, the cutting blade 9 can be reciprocated by the thrust force generated when the final gear 19 is driven by the drive gear 18. The tooth width B1 of the final gear 19 and the fourth gear 34 is set to be larger than the rotation region width B3 of the tooth row of the drive gear 18.

  In the above embodiment, the final gear 19 is fixed to the cutting blade shaft 9a. However, the final gear 19 may be connected to the cutting blade shaft 9a in a separable manner. The present invention may be applied to an electric razor not provided with the outer blade 12. In the fourteenth embodiment, the drive gear 18 is formed of a tooth inclination gear, but the final gear 19 may be formed of a tooth inclination gear, and the drive gear 18 may be formed of a spur gear.

1 Body case 2 Razor head 9 Cutting blade (inner blade)
9a Cutting blade shaft 10 Motor 12 Outer blade 18 Drive gear 19 Final gear 20 Drive gear gear teeth 21 Final gear gear teeth 22 Forward tooth surface 23 Reverse gear surface

Claims (9)

An electric razor that transmits the rotational power of the motor (10) to the cutting blade (9) provided in the razor head (2) via the final gear pair,
The final gear pair includes a final gear (19) connected to the cutting blade shaft (9a) of the cutting blade (9), and a drive gear (18) meshing with the final gear (19).
A thrust drive structure is provided at the meshing portion of the drive gear (18) and the final gear (19) to apply a thrust force in the direction of the rotation center axis to the final gear (19).
An electric razor characterized in that the cutting blade (9) is reciprocated by a thrust drive structure while being rotationally driven by a drive gear (18). The thrust drive structure is composed of forward tooth surfaces (22) and reverse tooth surfaces (23) provided on the gear teeth (20) of the drive gear (18) and / or the gear teeth (21) of the final gear (19). Has been
During the power transmission of the forward tooth surface (22), the final gear (19) is forwardly displaced by the thrust force generated between both gear teeth (20, 21),
At the time of power transmission of the return tooth surface (23), the forwardly displaced final gear (19) is moved backward by a thrust force generated between both gear teeth (20, 21) in the direction opposite to the forward displacement direction. The electric razor according to claim 1.   The electric shaver according to claim 2, wherein the forward movement and the backward movement are positively performed by inclining the forward movement tooth surface (22) and the backward movement tooth surface (23) in opposite directions.   The number of forward tooth surfaces (22) and the number of backward tooth surfaces (23) formed on the gear teeth (20) of the drive gear (18) and / or the gear teeth (21) of the final gear (19) are the same. The electric shaver according to claim 2 or 3, wherein   At least two sets of forward tooth surfaces (22) and reverse tooth surfaces (23) are provided on the gear teeth (20) of the drive gear (18) and / or the gear teeth (21) of the final gear (19), The electric shaver according to claim 4, wherein when the final gear (19) makes one rotation, the cutting blade (9) is reciprocated twice or more. The thrust drive structure is composed of a spur gear, and a dentition inclination gear in which the dentition center axis (P) of the gear teeth (31) is inclined with respect to the rotation center axis,
2. An electric shaver according to claim 1, wherein one of the drive gear (18) and the final gear (19) is formed by a spur gear, and the other is formed by a tooth inclination gear.   The tooth width (B1) of the drive gear (18) or the final gear (19) formed by the spur gear is the rotation region width in the axial direction of the drive gear (18) or the final gear (19) formed by the dentition inclined gear. The electric shaver according to claim 6, wherein the electric shaver is set larger than (B3).   The electric razor according to claim 6 or 7, wherein the pressing tooth surface (32) of the dentition inclined gear is formed as an outwardly curved surface.   The electric shaver according to any one of claims 6 to 8, wherein the inclination angle (θ) of the dentition center axis (P) is more than 0 degree and less than 45 degrees.

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