Electric equipment

Abstract

To reciprocally swing a working part provided at a tip of a functional member with an appropriate amplitude by improving a motion conversion structure of electric equipment in which functional components perform reciprocating swing motion, and prevent the entire electric equipment from enlarging due to increase in the length of a casing.SOLUTION: A motion converting structure 32 of electric equipment comprises an eccentric cam 34 fixed to an output shaft 5A of a motor 5, and swing conversion means 35 for converting rotating motion of the eccentric cam 34 into a reciprocating swing motion. The swing conversion means 35 is composed of a double lever mechanism including a support body 38 constituting a horizontal fixed link, a driver 39 disposed below the support body 38, having a drive shaft 33 protruding upward and constituting a connection link longer than the fixed link, and a pair of left and right swing arms 40 and 40 provided between the support body 38 and the driver 39 and constituting a swing link having the same length dimension.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric appliance such as an electric toothbrush in which a functional member having an operating portion provided on one end of a shaft performs a reciprocating swing motion. [Background technology]

[0002] An electric toothbrush, one such electrical device, as shown in Patent Document 1, for example, comprises a vertically long, hollow cylindrical case (casing), a drive motor supported by a frame within the case, a toothbrush body (functional component) protruding from the top end of the case, a connecting rod to which the toothbrush body is connected, and a motion conversion device (motion conversion structure) that converts the rotational motion of the drive motor into reciprocating vibrations in the left-right direction. The toothbrush body is composed of a vertically long shaft, with brush bristles (working parts) attached to its tip. The connecting rod is supported for swinging motion by a neck portion formed at the top end of the frame. The rotational motion of the drive motor is converted into reciprocating vibrations in the left-right direction by an eccentric cam and a long groove that constitute the motion conversion device, and transmitted to the connecting rod. This reciprocating vibration is converted into a seesaw-like reciprocating swing motion of the connecting rod, with the neck portion serving as the swing fulcrum. As a result, the connecting rod and the toothbrush body connected to the connecting rod swing back and forth in the left-right direction, with the neck portion serving as the swing fulcrum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-357 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in an electric toothbrush, it is desirable to make the amplitude of the bristles (tips of the toothbrush body) that oscillate back and forth relatively small. This is because if the amplitude of the bristles is relatively large, when the bristles are pressed against the teeth, a wider area can be brushed, but there is a risk of damaging the surface of the teeth or gums. Also, the reaction force from the oscillating motion of the toothbrush body acts on the case, causing the entire electric toothbrush to vibrate greatly, making it difficult to press the bristles into the desired position.

[0005] In the electric toothbrush of Patent Document 1, in order to make the amplitude of the brush bristles that oscillate back and forth like a seesaw around the oscillating fulcrum smaller than the amplitude of the reciprocating vibration converted by the eccentric cam and the long groove, the oscillating fulcrum (neck portion of the frame) between the connecting rod that oscillates back and forth like a seesaw and the toothbrush body needs to be located between the eccentric cam (motion conversion device) and the bristles, closer to the bristles. However, because the toothbrush body connected to the connecting rod needs to be long enough to be inserted deep inside the mouth, there is a limit to how short the overall length of the toothbrush body can be, and this inevitably requires increasing the distance from the neck portion to the eccentric cam, which increases the length of the case and the size of the toothbrush body.

[0006] The present invention aims to improve the motion conversion structure of an electrical device in which a functional member performs a reciprocating oscillating motion, thereby allowing the operating part provided at the tip of the functional member to perform a reciprocating oscillating motion with an appropriate amplitude, and to prevent the entire electrical device from becoming larger due to an increase in the length of the casing. [Means for solving the problem]

[0007] The electrical device according to the present invention comprises a vertically long casing 1 that also serves as a grip, a motor 5 housed within the casing 1, a drive shaft 33 driven by the motor 5 via a motion converting structure 32, and functional members 2, 102, 112 having operating portions 3, 103, 113 connected to the drive shaft 33 so as to extend upward from the casing 1. The motion converting structure 32 includes an eccentric cam 34 fixed to the output shaft 5A of the motor 5, and a swing motion converting means 35 that converts the rotational motion of the eccentric cam 34 into a reciprocating swing motion. The swing motion converting means 35 is characterized in that it is composed of a lever mechanism having a support 38 that constitutes a horizontal fixed link, a driver 39 that is disposed below the support 38 and has a drive shaft 33 that protrudes upward, and that constitutes a connecting link that is longer than the fixed link, and a pair of left and right swing arms 40 that are provided between the support 38 and the driver 39 and have the same length.

[0008] A pair of front and rear supports 38 are provided, and the upper side of each swing arm 40 is supported between the pair of supports 38 so as to be able to swing freely.

[0009] Each support body 38 is attached to the upper end of a vertical support frame 42 extending vertically. The lower ends of the front and rear vertical support frames 42 are connected by a horizontal support frame 43 extending longitudinally, and a support frame body 44 is formed by the pair of supports 38, the pair of vertical support frames 42, and the horizontal support frame 43.

[0010] The support frame 44 is made of an integrally formed metal molded product.

[0011] The motor holder 16 is disposed inside the casing 1 and has the motor 5 fixed thereto. The motor 5 and a support frame 44 are fixed to the motor holder 16.

[0012] The support body 38 and the oscillating arm 40 are connected to each other so as to be freely rotatable relative to each other by an upper pin 55 provided on one of them and an upper pin hole 56 provided on the other and fitted onto the upper pin 55, and the oscillating arm 40 and the driver 39 are connected to each other so as to be freely rotatable relative to each other by a lower pin 51 provided on one of them and a lower pin hole 54 provided on the other and fitted onto the lower pin 51.

[0013] The device includes an internal frame 15 disposed within the casing 1 and a switch board 8 on which an operation switch 7 for switching the drive state of the motor 5 is mounted. The internal frame 15 includes a motor holder 16 to which the motor 5 is fixed, and a battery holder 17 to which a battery 6 for supplying drive power to the motor 5 is fixed. The switch board 8 is held across the motor holder 16 and the battery holder 17.

[0014] The switch board 8 and the control board 9 are held at opposing positions on the outer circumferential surface of the inner frame 15. The control board 9 is provided with a control unit mounted thereon that controls the entire electrical device.

[0015] The power supply device C includes a power receiving board 10 having a power receiving coil that can be electromagnetically inductively coupled to the power supply coil of the power supply device C. The control board 9 and the power receiving board 10 are held on the outer circumferential surface of the internal frame 15, aligned vertically.

[0016] The motor holder 16 has a peripheral wall 18 that surrounds the side periphery of the motor 5. The battery holder 17 is provided with a pair of surrounding walls 25, 25 that cover the peripheral wall 18 of the motor holder 16 at opposing positions.

[0017] The peripheral wall 18 of the motor holder 16 and each surrounding wall 25 of the battery holder 17 are integrally joined by fixing means 26. [Effects of the Invention]

[0018] The electric device according to the present invention includes a motion converting structure 32 that includes an eccentric cam 34 fixed to the output shaft 5A of the motor 5, and a swing converting means 35 that converts the rotational motion of the eccentric cam 34 into a reciprocating swing motion. The swing converting means 35 is configured as a double lever mechanism having a support 38 that forms a horizontal fixed link, a driver 39 that is disposed below the support 38 and has a drive shaft 33 that projects upward, and that forms a connecting link that is longer than the fixed link, and a pair of left and right swing arms 40, 40 that are provided between the support 38 and the driver 39 and have the same length and form a swing link.

[0019] According to the electrical equipment configured as described above, when the rotation center between the support body 38 and the swing arm 40 is defined as R1 and the rotation center between the swing arm 40 and the driver 39 is defined as R2, a double lever mechanism can be configured in which, in the neutral position of the swing conversion means 35 shown in FIG. 9(b), a quadrangle with its vertices at the left and right rotation centers R1 and R2 is formed into an isosceles trapezoid whose bottom base is longer than its top base. Therefore, as shown in FIG. 1, a virtual swing fulcrum F of the driver 39 can be set at the position where virtual lines V·V passing through the upper and lower rotation centers R1·R2 of each swing arm 40 intersect. This virtual fulcrum F can be moved closer to or farther away from the driver 39 by changing the length of each link constituting both lever mechanisms (the length ratio between the fixed link and the connecting link, or the length of the oscillating link) and thereby changing the inclination angle of the oscillating arm 40 relative to the vertical direction. Therefore, by setting the virtual fulcrum F according to the length of the functional members 2, 102, and 112, the amplitude of the action units 3, 103, and 113 can be adjusted. Furthermore, since the drive shaft 33 provided on the driver 39 oscillates back and forth around the virtual fulcrum F rather than a physical fulcrum, there is no need to provide a physical fulcrum (neck portion) on the casing, as in conventional electric toothbrushes, and this prevents the casing from becoming too long. As described above, according to the electric device of the present invention, the action units 3, 103, and 113 provided at the tips of the functional members 2, 102, and 112 can be oscillated back and forth with an appropriate amplitude. Furthermore, according to the electric device of the present invention, the overall size of the electric device can be prevented from increasing due to an increase in the length of the casing 1. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a front view of a main part of an electric device (electric toothbrush) according to a first embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 2 is a vertical cross-sectional side view showing the internal structure of the casing. [Figure 5] FIG. [Figure 6] FIG. 2 is an exploded perspective view of the motion conversion structure. [Figure 7] FIG. 2 is an exploded side view of the internal structure of the casing. [Figure 8] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 9] 10 is a diagram for explaining the operation of the motion converting structure, and is an explanatory diagram showing an exaggerated amplitude of the drive body caused by the operation of the eccentric cam. FIG. [Figure 10] FIG. 10 is a vertical sectional front view showing the motion converting structure of an electric device (electric toothbrush) according to a second embodiment of the present invention. [Figure 11] FIG. 10 is a vertical sectional front view showing a motion converting structure of an electric device (electric toothbrush) according to a third embodiment of the present invention. [Figure 12] FIG. 10 is a vertical sectional plan view showing a motion converting structure of an electric device (electric toothbrush) according to a fourth embodiment of the present invention. [Figure 13] FIG. 10 is a front view schematically showing an electric device (massage device) according to a fifth embodiment of the present invention. [Figure 14] FIG. 10 is a front view schematically showing an electric appliance (shaver) according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] (First embodiment) Figures 1 to 9 show a first embodiment in which the electrical device of the present invention is applied to an electric toothbrush. In this embodiment, the front, back, left, right, and top and bottom refer to the crossed arrows shown in Figures 2 and 3 and the indications of front, back, left, right, and top and bottom written near each arrow. The same applies to the second and subsequent embodiments.

[0022] As shown in Figure 2, an electric toothbrush comprises a vertically elongated casing 1 that also serves as a grip, and a brush body (functional member) 2 that is detachably attached to the upper end of the casing 1. The brush body 2 is composed of a bristle bundle (working portion) 3 made up of countless brush bristles, and a brush shaft 4 that supports the bristle bundle 3. The lower part of the brush shaft 4 is formed in a truncated cone shape that widens downward, and the upper part of the brush shaft 4 is formed in an oval disk shape with its thickness extending in the front-to-back direction, with the bristle bundle 3 attached to the front side. When the bristle bundle 3 deteriorates with use, the brush body 2 can be removed from the casing 1 and replaced with a new one.

[0023] As shown in FIG. 3, the upper part of the hollow cylindrical casing 1 houses a motor 5, and the lower part houses a battery 6, which is a secondary battery. The cross section of the casing 1 where the motor 5 and battery 6 are housed is rectangular with rounded corners (see FIG. 8), and the cross section above this part gradually changes to a circular shape as it extends upward. The front part of the casing 1 houses a switch board 8 on which an operation switch 7 that switches the drive state of the motor is mounted, and the rear part houses a control board 9 on which a control unit that controls the entire electric toothbrush is mounted, and a power receiving board 10 for charging the battery 6, which has a power receiving coil. By distributing the relatively heavy motor 5 and battery 6 on both sides of the length (vertical direction) of the casing 1, the center of gravity of the electric toothbrush can be positioned at or near the center of the casing 1, making it easier for a user to hold the casing 1 by gripping the center of the casing 1.

[0024] As shown in FIG. 4, the operation switches 7 are arranged on the front of the switch board 8 and consist of a power switch 7A at the top and a speed change switch 7B at the bottom. Both switches 7A and 7B are momentary switches, and a display unit 11 consisting of a full-color LED is arranged between the switches 7A and 7B. As shown in FIG. 3, vertically long switch windows are opened in the front wall of the casing 1 overlooking each of the switches 7A and 7B. A power button 12A is arranged in the switch window overlooking the power switch 7A, and a speed change button 12B is arranged in the switch window overlooking the speed change switch 7B. Each of the buttons 12A and 12B is made of an elastic elastomer, and each button 12A and 12B itself functions as a packing to seal the switch window watertight and prevent water from entering the casing 1.

[0025] A user of the electric toothbrush can switch the drive state of the motor 5 by pressing the switches 7A and 7B via the buttons 12A and 12B. In this embodiment, the motor 5 is driven and stopped each time the power switch 7A is pressed, and the output of the motor 5 is switched from low to medium to high each time the variable speed switch 7B is pressed. The light color of the display unit 11 changes according to the drive state of the motor 5; for example, when the motor 5 is at low output, it emits yellow light, when the output is medium, it emits green light, and when the output is high, it emits blue light. Furthermore, when the battery 6 is being charged, the display unit 11 emits a color different from when the motor 5 is driven, such as orange. The front wall of the casing 1 is thinned in the portion directly facing the display unit 11 to form a transparent portion 11A (see FIG. 7 ), and the light emitted by the LED is displayed on the outer surface of the casing 1 through the transparent portion 11A.

[0026] When a non-contact power supply device C, shown by an imaginary line in Figure 3, is brought close to the power receiving board 10 and a current is passed through the power supply coil on the power supply board S provided in the power supply device C, a current flows through the power receiving coil on the power receiving board 10 due to electromagnetic induction, and this current charges the battery 6 via the control board 9. Although not shown, the battery 6 is shrink-wrapped and packaged together with a protection board. Note that the battery 6 may be a replaceable primary battery, in which case the power receiving board 10 can be omitted.

[0027] The motor 5, battery 6, and each of the circuit boards 8 to 10 are fixed to an internal frame 15 disposed within the casing 1. As shown in FIG. 3, the internal frame 15 is composed of a motor holder 16 to which the motor 5 is fixed and a battery holder 17 to which the battery 6 is fixed, and is formed as a whole in a vertically elongated shape similar to the casing 1. As shown in FIG. 4, the motor holder 16 is composed of a peripheral wall 18 that surrounds the sides of the motor 5 and an upper wall 19 that closes the upper opening of the peripheral wall 18, and the motor 5 is fixed to the motor holder 16 by being inserted through the lower opening of the peripheral wall 18. The output shaft 5A of the motor 5 protrudes upward from a shaft window 20 formed through the upper wall 19.

[0028] As shown in FIG. 7 , the battery holder 17 includes a motor frame portion 21 in the upper half to which the motor holder 16 is fixed, and a battery frame portion 22 in the lower half to which the battery 6 is fixed. The battery frame portion 22 is formed into a rectangular frame shape when viewed from the front, and the battery 6 is housed and fixed to the battery frame portion 22. The motor frame portion 21 is composed of a cylindrical lower frame portion 23 that is continuous with the upper side of the battery frame portion 22, and an upper frame portion 24 that is U-shaped in cross section and continuous with the upper side of the lower frame portion 23. As shown in FIG. 8 , the motor holder 16 is joined to the battery holder 17 so that it fits inside the upper frame portion 24. The upper frame portion 24 includes a pair of left and right surrounding walls 25. When the motor holder 16 is fitted inside the upper frame portion 24, the surrounding walls 25 overlap opposite positions on the left and right of the peripheral walls 18 of the motor holder 16.

[0029] As shown in Figures 4 and 8, the motor holder 16 and battery holder 17 are joined with screws (fastening means) 26. Specifically, the peripheral wall 18 of the motor holder 16 and the surrounding wall 25 of the battery holder 17 are fastened together with the screws 26, joining the two holders 16 and 17 together. The peripheral wall 18 has two bosses 27 on each of the top and bottom of its left and right faces, and each surrounding wall 25 has screw holes 28 that correspond to the bosses 27 and through which screws 26 are inserted. The two holders 16 and 17 can be joined together by placing the motor holder 16 inside the upper frame portion 24 from the front, aligning the bosses 27 with the screw holes 28, and then screwing the screws 26 into the bosses 27 through the screw holes 28.

[0030] As shown in Fig. 3, each of the circuit boards 8-10 is engaged and held by a pair of left and right retaining claws 29 provided on the inner frame 15. As shown in Fig. 7, two upper and lower retaining claw pairs 29A (29) for the switch circuit boards 8 are provided on the front surface of the peripheral wall 18 of the motor holder 16, and one retaining claw pair 29A for the switch circuit boards 8 is provided on the front surface of the lower frame portion 23 of the battery holder 17. Additionally, three upper and lower retaining claw pairs 29B (29) for the control circuit boards 9 are provided on the rear surface of the motor frame portion 21 of the battery holder 17. Additionally, three upper and lower retaining claw pairs 29C (29) for the power receiving circuit boards 10 are provided on the rear surface of the battery frame portion 22 of the battery holder 17.

[0031] The switch board 8 is locked and held by each of the retaining claw pairs 29A by pushing the switch board 8 toward the inner frame 15 from the front so as to elastically deform the retaining claw pairs 29A. Similarly, the control board 9 is locked and held by each of the retaining claw pairs 29B by pushing the control board 9 toward the inner frame 15 from the rear so as to elastically deform the retaining claw pairs 29B. Similarly, the power receiving board 10 is locked and held by each of the retaining claw pairs 29C by pushing the power receiving board 10 toward the inner frame 15 from the rear so as to elastically deform the retaining claw pairs 29C. The switch board 8 and the control board 9 are held in opposing positions at the front and rear of the outer circumferential surface of the inner frame 15, and the control board 9 and the power receiving board 10 are held side by side in the vertical direction on the rear surface of the outer circumferential surface of the inner frame 15.

[0032] The rotational motion of the output shaft 5A of the motor 5 is converted into a reciprocating swinging motion by the motion converting mechanism 32 and transmitted to the drive shaft 33, causing the brush assembly 2 connected to the drive shaft 33 to swing back and forth. As shown in FIGS. 4 and 5 , the motion converting mechanism 32 includes an eccentric cam 34 fixed to the output shaft 5A of the motor 5 and a swinging motion converting means 35 that converts the rotational motion of the eccentric cam 34 into a reciprocating swinging motion. The swinging motion converting means 35 is composed of two lever mechanisms and includes a pair of front and rear supports 38, 38 that form horizontal fixed links of the two lever mechanisms, a driver 39 that is disposed below the supports 38 and has a drive shaft 33 that protrudes upward and that forms a connecting link of the two lever mechanisms and is longer than the fixed links, and a pair of left and right swinging arms 40, 40 that are provided between the supports 38 and the driver 39 and have the same length and form swing links of the two lever mechanisms. In this embodiment, the length ratio between the fixed links and the connecting links of the two lever mechanisms is set to 1:1.3.

[0033] As shown in FIG. 6 , each support 38 is a curved, oval-shaped plate with a thickness in the front-to-rear direction. Retaining holes 41 for upper pins 55 (described later) are formed at the left and right ends of each support 38, extending front-to-rear. Each support 38 is integrally attached to the upper end of a vertically extending vertical support frame 42. The lower ends of the front and rear vertical support frames 42 are connected by a horizontal support frame 43 that also extends front-to-rear. Each vertical support frame 42 is formed of a plate with a thickness in the front-to-rear direction, and the horizontal support frame 43 is formed of a plate with a thickness in the up-to-down direction. The pair of supports 38, the pair of vertical support frames 42, and the horizontal support frame 43 form a support frame 44 that supports the swing arm 40 and the driver 39. The support frame 44 is a metal molded product formed by bending a metal plate cut into a predetermined shape. In FIG. 6 , reference numeral 45 denotes an insertion hole formed in the front of the horizontal support frame 43 for inserting the output shaft 5A of the motor 5. Also, in Figure 6, symbol 46 indicates screw holes through which screws 47 are inserted to fix the support frame body 44 to the internal frame 15, and the screw holes 46 are formed in three places on the support horizontal frame 43.

[0034] 4 and 5, bosses 48 into which screws 47 for fixing the support frame body 44 are screwed are formed on the left, right, and rear sides of the upper end of the peripheral wall 18 of the motor holder 16 to which the motor 5 is fixed. After aligning the motor holder 16 and the support frame body 44 so that the bosses 48 and the screw holes 46 match, the screws 47 are screwed into the bosses 48 through the screw holes 46, thereby fixing the two (motor holder 16 and support frame body 44) together.

[0035] As shown in Figure 6, the driver 39 is formed in the shape of a flat block extending in the vertical direction. Lower pins 51 are embedded and fixed in the front-rear direction at the left and right ends of the driver 39, with the front and rear ends of each lower pin 51 protruding outward from the left and right front and rear surfaces of the driver 39, respectively. A drive shaft 33 protrudes upward from the center of the left and right sides of the upper surface of the driver 39, and the drive shaft 33 is composed of a square-shaped base shaft 52 forming the lower half and a round-shaped connecting shaft 53 forming the upper half.

[0036] A pair of front and rear swing arms 40 are disposed between a pair of supports 38, 38, with one pair disposed in front of and one pair disposed behind the driver 39, for a total of four swing arms 40. Each swing arm 40 is formed in a rod shape, and a lower pin hole 54 is formed in its lower end so as to penetrate the front and rear of the swing arm, and an upper pin hole 56 is formed in its upper .... Bearings or bushings can be fitted on the inner peripheral surfaces of the upper pin hole 56 and the lower pin 51. The upper and lower pins 55, 51 are each formed from a metal round bar.

[0037] The swing conversion means 35 is assembled after the motor holder 16, to which the motor 5 is fixed, and the support frame 44 are integrally fixed. Specifically, the lower pin holes 54 of each swing arm 40 are first fitted onto the lower pins 51 of the driver 39, and the driver 39 and four swing arms 40 are assembled. Next, the upper pins 55 are inserted into the retaining holes 41 located on the left of the rear support 38, then into the upper pin holes 56 of the two swing arms 40 located on the left of the driver 39, and then into the retaining holes 41 located on the left of the front support 38, and each retaining hole 41 and the upper pin 55 are joined by welding, caulking, or the like. The two swing arms 40 located on the right side are assembled in a similar manner. In this way, the members constituting the swing conversion means 35 can be assembled to the support frame 44. The distance between the opposing surfaces of the front and rear supports 38 is set to the sum of the front-to-rear thickness of the driver 39 and the thickness of the front and rear swing arms 40, and each swing arm 40 and driver 39 is supported so as to be able to swing freely while positioned between the front and rear supports 38.

[0038] When the rotation center between the support 38 and the swing arm 40 is defined as R1 and the rotation center between the swing arm 40 and the driver 39 is defined as R2, the swing conversion means 35 of this embodiment is configured as a double-lever mechanism in which a quadrangle (quadrilateral R1(left)R1(right)R2(right)R2(left)) with the left and right rotation centers R1 and R2 as vertices is formed as an isosceles trapezoid with the bottom base longer than the top base when the swing conversion means 35 is in the neutral position shown in Figure 9(b). With this double-lever mechanism configured as above, a virtual swing fulcrum F of the driver 39 can be set at the position where virtual lines V·V passing through the upper and lower rotation centers R1·R2 of each swing arm 40 intersect, as shown in Figure 1. The virtual swing fulcrum F is set above the upper end of the casing 1 (outside the casing 1), and the driver 39 swings back and forth between Figure 9(a) and Figure 9(c) and traces a movement trajectory T that is a downward-projecting arc when viewed from the front.

[0039] As shown in Figure 6, a cam pin 57 protrudes upward from the eccentric cam 34 at a position eccentric to the output shaft 5A of the motor 5, and the tip of the cam pin 57 is formed into a spherical shaft. A cam groove 58, which is a groove extending in the front-rear direction and into which the cam pin 57 engages, is provided in the center of the left-right direction on the underside of the driver 39. The cam pin 57 and the cam groove 58 engage when the motor holder 16 and the support frame 44 are assembled. Forming the tip of the cam pin 57 into a spherical shaft keeps the contact state between the cam pin 57 and the inner surface of the cam groove 58 constant even when the driver 39 swings and tilts the cam groove 58. This allows the rotation of the motor 5 to be transmitted to the driver 39 accurately and without delay.

[0040] When the motor 5 is driven, as shown in Figures 9(a) to 9(c), the rotational motion of its output shaft 5A is converted into a reciprocating vibration motion of the driver 39 by the cam pin 57 and cam groove 58 of the eccentric cam 34. This converted reciprocating vibration motion is converted by the vibration conversion means 35 into a reciprocating vibration motion of the driver 39 about the virtual vibration fulcrum F described above, and is transmitted to the drive shaft 33. As a result, the brush body 2 connected to the drive shaft 33 performs a seesaw-like reciprocating vibration motion about the virtual vibration fulcrum F shown in Figure 1. In this embodiment, the virtual vibration fulcrum F is set closer to the bristle bundle 3 between the bristle bundle 3 (the tip of the brush body 2) and the driver 39 (the part that generates the reciprocating vibration), and therefore the amplitude of the bristle bundle 3 is smaller than the amplitude of the driver 39.

[0041] As shown in Figure 5, a shaft through-hole 61 is provided in the top wall of the casing 1 to allow the connecting shaft 53 portion of the drive shaft 33 to pass through, and the diameter of the shaft through-hole 61 is formed to be sufficiently larger than the outer diameter of the connecting shaft 53. To prevent water from entering the casing 1 through the shaft through-hole 61, a shaft packing 62 forms a watertight seal between the connecting shaft 53 and the opening edge of the shaft through-hole 61. The peripheral edge of the shaft packing 62 is sandwiched from above and below by the top wall of the casing 1 and an annular packing ring 63 fixed to its outer surface. A cylindrical packing tube 64 is formed in the center of the shaft packing 62 and penetrates it from top to bottom. The inner diameter of the packing tube 64 is the same as or slightly smaller than the diameter of the connecting shaft 53. In order to improve the watertightness between the connecting shaft 53 and the packing tube 64, a tightening spring 65 made of a tightly wound coil spring whose coil inner diameter is smaller than the outer diameter of the packing tube 64 is attached to the outer surface of the packing tube 64. When the connecting shaft 53 is inserted into the packing tube 64, the elastic restoring force of the tightening spring 65 presses the packing tube 64 against the connecting shaft 53, improving the watertightness between the two (connecting shaft 53 and packing tube 64).

[0042] The electric toothbrush is assembled in the following manner. The driver 39 and swing arm 40 that constitute the swing converter 35 are assembled to the support frame 44 as a unit, and the motor 5 and eccentric cam 34 are assembled to the motor holder 16 as a unit. First, the unit including the swing converter 35 and the unit including the motor 5 are fastened together with screws 47, and then these combined units are fastened to the battery holder 17 with screws 26 to integrate the inner frame 15. Next, while routing wiring (not shown), the battery 6 and each of the circuit boards 8 to 10 are fixed to the inner frame 15 to construct the inner unit, and the inner unit is then inserted into the casing 1 through the insertion opening 66 provided on the bottom surface of the casing 1.

[0043] After the internal unit is inserted into the casing 1, the insertion opening 66 is closed by a bottom cover 67. As shown in FIG. 7, the bottom cover 67 is formed with an engaging protrusion 69 that engages with an engaging recess 68 formed as a recess on the inner surface of the lower part of the casing 1, and as shown in FIG. 3, the bottom cover 67 that closes the insertion opening 66 is held in place by the engaging protrusion 69 engaging with the engaging recess 68. The bottom cover 67 is formed with a holding protrusion 70 that supports the internal frame 15 from below, and the internal frame 15 is held in a predetermined position within the casing 1 by the holding protrusion 70. A rubber O-ring 71 is disposed on the bottom cover 67, and this O-ring 71 comes into close contact with the inner peripheral surface of the casing 1, thereby forming a watertight seal between the insertion opening 66 and the bottom cover 67.

[0044] When the internal frame 15 is assembled to the casing 1, the upper half of the connecting shaft 53 of the drive shaft 33 protrudes upward from the upper end of the casing 1. A vertically elongated connecting hole 72 is recessed in the underside of the brush shaft 4, and by inserting the protruding portion of the connecting shaft 53 into this connecting hole 72, the brush body 2 is connected to the drive shaft 33 and the brush body 2 can be attached to the casing 1.

[0045] In the above embodiment, the upper pin 55 is fixed to the support 38 and the lower pin 51 is fixed to the driver 39, but the upper and lower pins 55 and 51 can be fixed to the swing arm 40. In this case, an upper pin hole 56 is formed in the support 38 and a lower pin hole 54 is formed in the driver 39.

[0046] Second Embodiment FIG. 10 shows a second embodiment in which the electrical device of the present invention is applied to an electric toothbrush. This embodiment differs from the first embodiment in that supports 38 are integrally formed on the inner surface of casing 1. Supports 38 protrude inward from the left and right sides of the upper inner surface of casing 1, and retaining holes 41 are formed in each of the left and right supports 38. Casing 1 is composed of a pair of halves 1A, divided into front and rear halves. The upper pin 55, oscillating arm 40, and driver 39 constituting oscillation conversion means 35, as well as an inner frame 15 to which these components are fixed, are assembled to one half 1A. The other half 1A is then placed over the casing 1, and the two halves 1A are fastened together by a fastening structure (not shown). The components are housed within the casing 1. Since the casing 1 is composed of front and rear halves 1A, the bottom cover 67 is eliminated. The rest of the configuration is the same as in the first embodiment, so the same components are denoted by the same reference numerals and the description thereof will be omitted.

[0047] (Third Embodiment) Figure 11 shows a third embodiment in which the electrical device of the present invention is applied to an electric toothbrush. This embodiment differs from the first embodiment in that the driver 39, swing arm 40, and upper pin 55 are integrally formed from a plastic molded product. By integrally forming the driver 39 and swing arm 40, the driver 39 is swingably supported relative to the swing arm 40 by connection with an elastic hinge 75, instead of a rotation pair between the lower pin 51 and the lower pin hole 54. It is also possible to integrally form the support body 38, driver 39, and swing arm 40, and swingably support the support body 38 and swing arm 40, and the swing arm 40 and driver 39, respectively, with elastic hinges.

[0048] In each of the above embodiments, the support body 38 and the swing arm 40, and the swing arm 40 and the driver 39 are swingably connected by a revolute pair or hinge consisting of a pin and a pin hole, but the swing arm 40 may be configured so that the entire body of the swing arm 40 elastically deforms to swingably connect the above members.

[0049] (Fourth Embodiment) Figure 12 shows a fourth embodiment in which the electrical device of the present invention is applied to an electric toothbrush. This embodiment differs from the first embodiment in that the manner in which the oscillation conversion means 35 is operated by the eccentric cam 34 has been changed. An interlocking pin 76 protrudes downward from the left lower surface of the driver 39. This interlocking pin 76 and the cam pin 57 are connected by an interlocking link 77, so that the driver 39 of the oscillation conversion means 35 is operated by the eccentric cam 34. Accordingly, the cam groove 58 into which the cam pin 57 engages is eliminated. As a variation of this embodiment, the interlocking pin 76 can be provided on either the left or right oscillation arm 40. In this case, the interlocking pin 76 and the cam pin 57 are connected by the interlocking link 77, and the oscillation arm 40 of the oscillation conversion means 35 is operated by the eccentric cam 34.

[0050] Fifth Embodiment Fig. 13 shows a fifth embodiment in which the electrical device of the present invention is applied to a handheld massager. This massager includes a vertically elongated casing 1 that also serves as a grip, and a treatment member (functional member) 102 detachably attached to the upper end of the casing 1. The treatment member 102 is composed of a spherical treatment element (working unit) 103 and a treatment shaft 104 that supports the treatment element 103. In this embodiment, the vertical distance between the fixed link and the connecting link of both lever mechanisms is the same as in the first embodiment, but the length ratio between the fixed link and the connecting link is set to 1:1.8. Accordingly, in the neutral position of the oscillation conversion means 35, the inclination angle of the oscillation arm 40 relative to the vertical direction is larger than in the first embodiment, and the virtual oscillation fulcrum F is closer to the driver 39. The virtual oscillation fulcrum F is set to a substantially midpoint between the treatment element 103 (the tip of the treatment element 102) and the driver 39 (the part that generates the reciprocating vibration). As a result, the amplitude of the drive body 39 and the amplitude of the treatment element 103 are substantially the same.

[0051] Sixth Embodiment Figure 14 shows a sixth embodiment in which the electrical device of the present invention is applied to a shaver. The shaver comprises a vertically elongated casing 1 that also serves as a grip, and an inner blade member (functional member) 112 that is removably attached to the upper end of the casing 1. The inner blade member 112 is composed of a cutting blade group (working portion) 113 consisting of multiple cutting blades, and a cutting blade base 114 that supports the cutting blade group 113. An outer blade member 115 is removably attached to the upper end of the casing 1 so as to cover the inner blade member 112. The outer blade member 115 is composed of a mesh blade 116 that cooperates with the inner blade member 112 to cut hair growing on the body surface, and a mesh blade holder 117 that holds the mesh blade 116.

[0052] In this embodiment, the vertical distance between the fixed link and the connecting link of both lever mechanisms remains the same as in the first embodiment, but the length ratio between the fixed link and the connecting link is set to 1:2.3. Accordingly, when the swing converter 35 is in its neutral position, the inclination angle of the swing arm 40 relative to the vertical direction is larger than in the fifth embodiment, and the virtual swing fulcrum F is closer to the driver 39. However, since the overall length of the inner blade member (functional member) 112 is shorter, the virtual swing fulcrum F is set closer to the cutting edge group 113 (the tip of the inner blade member 112) and the driver 39 (the part that generates the reciprocating vibration). As a result, the amplitude of the cutting edge group 113 is smaller than that of the driver 39.

[0053] As described above, in the electric devices (electric toothbrushes, massagers, shavers) according to each embodiment of the present invention, the motion converting structure 32 is configured to include the eccentric cam 34 fixed to the output shaft 5A of the motor 5, and the swing motion converting means 35 that converts the rotational motion of the eccentric cam 34 into a reciprocating swing motion. In addition, the swing motion converting means 35 is configured as a double lever mechanism having a support 38 that constitutes a horizontal fixed link, a driver 39 that is disposed below the support 38 and has a drive shaft 33 that protrudes upward and constitutes a connecting link that is longer than the fixed link, and a pair of left and right swing arms 40, 40 that are provided between the support 38 and the driver 39 and constitute a swing link having the same length.

[0054] According to the electrical equipment configured as described above, when the rotation center between the support body 38 and the swing arm 40 is defined as R1 and the rotation center between the swing arm 40 and the driver 39 is defined as R2, a double lever mechanism can be configured in which, in the neutral position of the swing conversion means 35 shown in FIG. 9(b), a quadrangle with its vertices at the left and right rotation centers R1 and R2 is formed into an isosceles trapezoid whose bottom base is longer than its top base. Therefore, as shown in FIG. 1, a virtual swing fulcrum F of the driver 39 can be set at the position where virtual lines V·V passing through the upper and lower rotation centers R1·R2 of each swing arm 40 intersect. This virtual fulcrum F can be moved closer to or farther away from the driver 39 by changing the length of each link constituting both lever mechanisms (the length ratio between the fixed link and the connecting link, or the length of the oscillating link) and thereby changing the inclination angle of the oscillating arm 40 relative to the vertical direction. Therefore, by setting the virtual fulcrum F according to the length of the functional members 2, 102, and 112, the amplitude of the action units 3, 103, and 113 can be adjusted. Furthermore, since the drive shaft 33 provided on the driver 39 oscillates back and forth about the virtual fulcrum F rather than a physical fulcrum, there is no need to provide a physical fulcrum (neck portion) on the casing, as in conventional electric toothbrushes, and this prevents the casing from becoming too long. As described above, according to the electric device of this embodiment, the action units 3, 103, and 113 provided at the tips of the functional members 2, 102, and 112 can be oscillated back and forth with an appropriate amplitude, and the overall size of the electric device can be prevented from increasing due to the length of the casing 1.

[0055] A pair of front and rear supports 38, 38 are provided, and the upper side of each swing arm 40 is supported so that it can swing freely while being positioned between the pair of supports 38, 38.By supporting the front and rear outer sides of the swing arm 40 with the supports 38, it is possible to prevent the swing axis of the swing arm 40, which swings back and forth relative to the supports 38, from tilting, and the swing arm 40 can be accurately supported to swing around the specified swing axis.

[0056] The lower ends of the front and rear vertical support frames 42, each having a support 38 at its upper end, are connected by a horizontal support frame 43 extending forward and backward, and a support frame body 44 is formed by the pair of supports 38, 38, the pair of vertical support frames 42, 42, and the horizontal support frame 43.This prevents the swing axis of the swing arm 40 from tilting and prevents the opposing distance between the pair of supports 38 from changing, allowing the swing arm 40 to be swingably supported more accurately around the specified swing axis.

[0057] Since the support frame 44 is made of an integrally formed metal molded product, the structural strength of the support frame 44 is increased compared to a support frame made of a plastic molded product, making it possible to prevent the opposing distance between the pair of supports 38, 38 from changing over the long term, thereby improving the reliability of the motion converting structure 32.

[0058] Since the motor 5 and the support frame 44 are fixed to the motor holder 16 to which the motor 5 is fixed, it is possible to maintain the accuracy of the relative position between the motor 5 and the support frame 44, that is, the relative position between the eccentric cam 34 and the oscillation conversion means 35, while properly defining it, and the rotational motion of the motor 5 can be converted into a reciprocating oscillation motion without loss.

[0059] The support body 38 and the oscillating arm 40 are connected to each other so as to be rotatable relative to each other by the upper pin 55 and the upper pin hole 56 that fits onto the upper pin 55, and the oscillating arm 40 and the driver 39 are connected to each other so as to be rotatable relative to each other by the lower pin 51 and the lower pin hole 54 that fits onto the lower pin 51. This makes it possible to smooth the movement of each oscillating rotating part, convert the rotational motion of the motor 5 into a reciprocating oscillating motion without loss, and also reduces the driving noise to make the electrical equipment quieter.

[0060] The device comprises an internal frame 15 disposed within the casing 1 and a switch board 8 on which an operation switch 7 for switching the drive state of the motor 5 is mounted, and the internal frame 15 is configured to include a motor holder 16 to which the motor 5 is fixed and a battery holder 17 to which a battery 6 for supplying drive power to the motor 5 is fixed. In addition, the switch board 8 is held across the motor holder 16 and the battery holder 17, so that even if the casing 1 is subjected to an external impact due to a fall or the like and the impact is transmitted to one of the holders 16 (17) of the motor holder 16 or the battery holder 17, the switch board 8 is firmly held by the other holder 17 (16), preventing the switch board 8 from falling off the internal frame 15.

[0061] The device is provided with a control board 9 on which a control unit that controls the entire electrical equipment is mounted, and the switch board 8 and the control board 9 are held in opposing positions on the outer circumferential surface of the inner frame 15. This makes it possible to selectively remove one of the switch board 8 and the control board 9 compared to when the switch board 8 and the control board 9 are held on the outer circumferential surface of the inner frame 15 in an overlapping state, thereby improving workability during repairs.

[0062] The power supply device C is provided with a power receiving board 10 having a power receiving coil that can be electromagnetically inductively coupled to the power supply coil of the power supply device C, and the control board 9 and the power receiving board 10 are held vertically side by side on the outer surface of the internal frame 15. This makes it possible to selectively remove one of the control board 9 and the power receiving board 10 compared to when the control board 9 and the power receiving board 10 are held on the outer surface of the internal frame 15 in an overlapping state, thereby improving workability during repairs.

[0063] The motor holder 16 has a peripheral wall 18 that surrounds the side periphery of the motor 5, and the battery holder 17 is provided with a pair of surrounding walls 25, 25 that cover opposite positions of the peripheral wall 18 of the motor holder 16. Therefore, if the casing 1 receives an external shock due to being dropped, for example, the external shock can be absorbed by the peripheral wall 18 and the surrounding wall 25, thereby protecting the motor 5.

[0064] The peripheral wall 18 of the motor holder 16 and each surrounding wall 25 of the battery holder 17 are joined together by fastening means 26, so the internal frame 15 is integrated without the need for a separate structure to join the motor holder 16 and battery holder 17, preventing the structure inside the casing 1 from becoming complicated.

[0065] The electrical device according to the present invention can contribute to Goal 9 (build resilient infrastructure, promote inclusive and sustainable industrialization, innovate and foster innovation) of the Sustainable Development Goals (SDGs) advocated by the United Nations. [Explanation of symbols]

[0066] 1 casing 2 Functional component (brush body) 3. Working part (hair bundle) 5 motors 5A output shaft 6 batteries 7 Operation switch 8 Switch board 9 Control board 10 Power receiving board 15 Internal Frame 16 Motor holder 17 Battery holder 18 Peripheral wall 25 Siege Wall 26 Fixing means (screws) 32 Action transformation structure 33 Drive shaft 34 Eccentric Cam 35 Swing conversion means 38 Support 39 Driver 40 Swing arm 42 Support vertical frame 43 Support horizontal frame 44 Support frame 51 Lower pin 54 Lower pin hole 55 Upper pin 56 Upper pin hole 102 Functional components (treatment components) 103 Action part (treatment element) 112 Functional parts (inner blade parts) 113 Working part (cutting blade group) C. Power supply device

Claims

1. A long casing (1) that doubles as a grip, a motor (5) housed in the casing (1); a drive shaft (33) driven by a motor (5) via a motion conversion structure (32); a functional member (2, 102, 112) having an operating portion (3, 103, 113) connected to a drive shaft (33) so as to extend upward from the casing (1); Equipped with The motion converting structure (32) includes an eccentric cam (34) fixed to the output shaft (5A) of the motor (5), and a swing converting means (35) for converting the rotational motion of the eccentric cam (34) into a reciprocating swing motion; The electric device is characterized in that the swing conversion means (35) is composed of a lever mechanism having a support (38) constituting a horizontal fixed link, a driver (39) arranged below the support (38) and having a drive shaft (33) protruding upward, constituting a connecting link longer than the fixed link, and a pair of left and right swing arms (40, 40) provided between the support (38) and the driver (39) and constituting a swing link of the same length.

2. A pair of front and rear supports (38, 38) are provided, 2. An electrical device according to claim 1, wherein the upper side of each swing arm (40) is supported so as to be swingable between a pair of supports (38, 38).

3. Each support (38) is provided at the upper end of a vertically extending support frame (42), 3. The electrical equipment according to claim 2, wherein the lower ends of the front and rear vertical support frames (42) are connected by a horizontal support frame (43) extending in the front-to-rear direction, and a support frame body (44) is formed by the pair of supports (38, 38), the pair of vertical support frames (42, 42), and the horizontal support frame (43).

4. 4. The electrical device according to claim 3, wherein the support frame (44) is an integrally formed metal molding.

5. The motor holder (16) is disposed in the casing (1) and has a motor (5) fixed thereto.

5. An electric device according to claim 4, wherein the motor (5) and the support frame (44) are fixed to a motor holder (16).

6. 6. An electrical device according to claim 1, wherein the support (38) and the oscillating arm (40) are connected to each other so as to be rotatable relative to each other by an upper pin (55) provided on one of them and an upper pin hole (56) provided on the other and fitted onto the upper pin (55), and the oscillating arm (40) and the driver (39) are connected to each other so as to be rotatable relative to each other by a lower pin (51) provided on one of them and a lower pin hole (54) provided on the other and fitted onto the lower pin (51).

7. The device includes an internal frame (15) disposed within the casing (1) and a switch board (8) on which an operation switch (7) for switching the driving state of the motor (5) is mounted. The internal frame (15) includes a motor holder (16) to which the motor (5) is fixed, and a battery holder (17) to which a battery (6) that supplies driving power to the motor (5) is fixed.

5. The electrical device according to claim 1, wherein the switch board (8) is held across the motor holder (16) and the battery holder (17).

8. The device is provided with a control board (9) on which a control unit for controlling the entire electrical device is mounted, 8. The electric device according to claim 7, wherein a switch board (8) and a control board (9) are held at opposing positions on the outer peripheral surface of the inner frame (15).

9. a power receiving substrate (10) having a power receiving coil that can be electromagnetically inductively coupled to a power feeding coil of the power feeding device (C); 9. The electric device according to claim 8, wherein the control board (9) and the power receiving board (10) are held on the outer peripheral surface of the inner frame (15) in a vertically aligned arrangement.

10. The motor holder (16) has a peripheral wall (18) that surrounds the side periphery of the motor (5), 8. The electric device according to claim 7, wherein the battery holder (17) is provided with a pair of surrounding walls (25, 25) that cover opposing positions of the peripheral wall (18) of the motor holder (16).

11. 11. The electrical device according to claim 10, wherein the peripheral wall (18) of the motor holder (16) and each surrounding wall (25) of the battery holder (17) are integrally joined by fixing means (26).

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