JP4642376B2 - Electric toothbrush appliance - Google Patents

Description

  The present invention relates to an electric toothbrush device that vibrates a toothbrush portion with a driving power source such as an electric motor.

  An electric toothbrush device is known in which a drive shaft protruding upward from a main body is reciprocated in a length direction (axial direction, vertical direction), and a toothbrush portion is detachably attached to the protruding end of the drive shaft from above. is there.

Japanese Patent No. 2523304 JP-A-4-364806 JP-A-11-253232

  Patent Document 1 discloses a drive mechanism in which rotation of an electric motor housed in a main body is decelerated by a bevel gear mechanism, and a drive shaft is reciprocally oscillated in an axial direction (vertical direction) by an eccentric cam.

  Patent Document 2 shows that a seal member (waterproof cap) is mounted between the main body and the drive shaft in order to prevent water droplets dripping from the toothbrush from entering the main body from the vicinity of the drive shaft. Yes. Here, the seal member has one end fitted to the drive shaft and the other end attached to the main body, and the lower portion of the toothbrush portion is made larger (larger diameter) than one end (upper end) fitted to the drive shaft of the seal member. ing. That is, the water-drop effect is improved by dropping water drops that are transmitted to the outer surface of the toothbrush portion to the outside of the end (upper end) of the seal member by the large (large-diameter) portion of the lower portion.

  In Patent Document 2, the waterproof effect in the main body can be improved by connecting the lower surface (base end portion) of the toothbrush portion and the shaft fitting portion (one end, upper end) of the waterproof cap seamlessly in the axial direction. (Paragraphs 0021 and 0027).

  Cited Document 3 shows that a spring body for preventing rattling is provided to urge a drive shaft that reciprocates in the axial direction to one side in the axial direction. The spring body is preferably a substantially conical coil spring, for example (paragraph 0006).

  Patent Document 2 shows that the sealing member and the toothbrush portion are continuously connected to improve waterproofness, but here, by applying a preload to the drive shaft, the play of the drive system is improved. It has not been shown to prevent the generation of noise.

  Patent Document 3 shows that by applying a preload (preload) in one direction to the drive shaft (5) by the spring body (7), the generation of rattling noise (operation noise) is suppressed ( Paragraphs 0005, 0019, etc.). However, this spring body (7) is mounted separately from the waterproof packing (13), and since the spring body (7) is, for example, a coil spring, it is totally expected that the spring body (7) will have a waterproof function. Not done. For this reason, the spring body and the waterproof packing must be used separately, the number of parts increases, the structure becomes complicated, and the assemblability also deteriorates.

  In addition, in the actual product, play between the toothbrush portion and the drive shaft may also occur, and if this play occurs, noise is also generated from here, but in the conventional product, this noise was not considered. .

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide an electric toothbrush device that can prevent generation of rattling noise (operation noise) with improved waterproofness with a small number of parts. And

  According to the present invention, the object is to attach a toothbrush part detachably from above to a drive shaft that protrudes upward from a body part containing a drive part and is vibrated by the drive part, and the body part and the toothbrush part In the electric toothbrush appliance having a seal member interposed between the opposed surfaces thereof, the seal member includes an inner annular portion that is liquid-tightly fixed to the drive shaft, and an outer annular portion that is liquid-tightly fixed to the main body portion, An upper surface annular portion that is above the inner and outer annular portions and press-contacted to the lower surface of the toothbrush portion is provided, and a preload in a constant direction is always applied to the drive shaft in a mounted state of the toothbrush portion. This is achieved by an electric toothbrush device (Claim 1).

  The same purpose is to attach a toothbrush part detachably from above to a drive shaft that protrudes upward from a body part containing a drive part and is vibrated by the drive part, and between the opposing surfaces of the body part and the toothbrush part. In the electric toothbrush device having a seal member interposed therebetween, the seal member includes an inner annular portion that is liquid-tightly fixed to the drive shaft and an outer annular portion that is liquid-tightly fixed to the main body portion, and the toothbrush portion The restoring force f applied to the drive shaft by the relative displacement between the inner annular portion and the outer annular portion in the non-attached state always applies a preload in a certain direction to the drive shaft in the attached state of the toothbrush portion. It is also achieved by the electric toothbrush device (claim 8).

  According to the first aspect of the present invention, the inner annular portion of the seal member is fixed to the drive shaft, the outer annular portion is fixed to the main body side, and the upper annular portion is pressed down on the lower surface of the toothbrush portion. When the toothbrush portion is mounted on the drive shaft, a load (restoring force F) synthesized by the restoring force due to the relative displacement between the inner and outer annular portions of the seal member and the displacement of the upper annular portion is applied to the driving shaft. Join. Since this combined restoring force F always applies a preload in a fixed direction to the drive shaft with reference to the main body, noise caused by rattling is restricted by controlling play of the drive system of the drive shaft. Can be prevented.

  Further, the pressing force applied to the upper annular portion of the seal member can surely prevent generation of noise due to play between the toothbrush portion and the drive shaft. For this reason, the operation can be made extremely quiet. Furthermore, since the two effects of absorbing the waterproof and the play of the drive system and the play of the drive shaft and the toothbrush portion are obtained with only the seal member, the number of parts can be reduced, the structure is simplified, and the assemblability is improved.

  According to the invention of claim 8, since a preload in a fixed direction is applied to the drive shaft by the relative displacement between the inner annular portion and the outer annular portion of the seal member, the play of the drive system of the drive shaft is restricted and noise is reduced. Occurrence can be prevented. Moreover, the waterproofness of the main body side is also improved.

  If the force applied to the drive shaft is analyzed, the restoring force f applied to the drive shaft by the seal member in a state where the toothbrush portion is not mounted (free state), and the lower surface of the toothbrush portion (with the main body portion with the toothbrush portion mounted) A pressing force α that presses (presses down) the upper surface annular portion by the opposing surface) restore force kα applied to the drive shaft (generated in the inner annular portion by pressing the upper surface annular portion with reference to the outer annular portion of the seal member) It is a resilience).

  Here, the restoring force f is generated as follows. That is, when the seal member is attached to the main body, the outer annular portion is fixed to the main body, while the drive shaft to which the inner annular portion is fixed has its movable range restricted by the drive system. For this reason, the seal member is deformed by a predetermined amount between the main body portion and the drive shaft even when the toothbrush portion is not mounted, and a restoring force f is generated by this deformation.

  At this time, the total restoring force applied to the drive shaft, that is, the total load F is F = f + kα. In the present invention, the total load F is always in one direction regardless of the reciprocating position of the drive shaft (claim 2).

  Generally, the seal member applies a preload downward (in the direction toward the main body) to the drive shaft (Claim 3). In this case, when the tip of the toothbrush portion is pressed toward the tooth, etc. Even when a downward external load is applied to the toothbrush, no adverse effect (such as increased noise) due to drive system play does not occur. However, the present invention can also apply a preload upward (in the direction toward the toothbrush).

  When the restoring force f is downward and the load kα is upward, the total load F can be made downward by setting | f |> | kα |. In this case, since the restoring forces f and kα have opposite directions, the total load F can be reduced, which is convenient for reducing the load of a driving source such as a motor.

  When the restoring force f and the restoring force kα are both downward, the absolute values | f | and | kα | of f and kα may be reduced in order to prevent the total load F = f + kα from becoming excessive. desirable. If | kα | is smaller than | f | at this time, the amount of deformation of the seal member accompanying attachment / detachment of the toothbrush portion is reduced, and the durability of the seal member is improved. If | f | and | kα | are large, the amount of change in these values increases as the stroke amount (reciprocating distance) of the drive shaft increases, so the load on the drive system increases. Therefore, this case is suitable for the case where the stroke amount is small, for example, the stroke amount (mm) is reduced and the reciprocating frequency (stroke number) (times / second) is increased.

  When the restoring force f is upward, an upward preload can be applied to the drive shaft. In this case, the play of the drive system cannot be absorbed when a downward external load larger than the load F is applied to the toothbrush portion, but conversely, when a large upward external load is applied, the play is not adversely affected (such as noise) and the toothbrush portion Can be pulled downward with strong force.

  In general, the drive shaft reciprocates in the axial direction (Claim 7). However, the present invention is such that the drive shaft reciprocates around the axial direction, and the vicinity of the inner annular portion of the seal member. Including those that swing as a fulcrum in a direction perpendicular to the axial direction. This is because, in such a case, if the seal member applies a preload in the axial direction of the drive shaft, play in the axial direction of the drive system can be suppressed.

  In this invention, the drive shaft protrudes upward from the main body and the toothbrush portion is attached and detached from above. However, when the main body is turned upside down and the drive shaft protrudes downward from the main body, the vertical relationship is It is just the opposite, and it does not essentially change the action or effect. Accordingly, the present invention naturally includes those upside down.

  FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a part thereof, and FIG. In FIGS. 1 and 2, reference numeral 10 denotes a main body, and the lower part is slightly bent and the whole is substantially cylindrical. An electric motor 12 is housed near the center of the main body, and a battery 14 is housed in the lower part. The battery 14 may be a primary battery such as a dry battery, or a rechargeable secondary battery.

  A drive shaft 16 is held at the upper part in the main body 10 so as to be able to reciprocate in the vertical direction (the central axis direction of the main body 10). That is, the drive shaft 16 is held by a linear bearing 20 that is sandwiched between the left and right inner cases 18, 18, and an upper portion thereof protrudes above the main body 10. The lower part of the drive shaft 16 is reciprocated in the vertical direction by the drive unit 22.

  The drive unit 22 includes a cylindrical eccentric cam 28 that is rotated by the electric motor 12 via the bevel gears 24 and 26, and a cam follower 30 that engages with the cam 28. The cam 28 is held by a horizontal shaft 32 that is orthogonal to the drive shaft 16. The cam follower 30 is fixed to the lower end of the drive shaft 16. The horizontal shaft 32 and the electric motor 12 are held between the inner cases 18 and 18.

  The inner cases 18 and 18 incorporating the electric motor 12, the drive shaft 16, and the drive unit 22 in this manner are inserted into the outer case 34 of the main body 10 from below while being coupled to each other by engagement claws or the like. Do not engage with the engaging claws. In FIG.

  A seal member 38 is attached to the outer periphery of the upper ends of the inner cases 18 and 18. That is, the seal member 38 is provided with an upper surface annular portion 44 that is annularly and bulged upwardly between the inner annular portion 40 and the outer annular portion 42, and is entirely formed of synthetic rubber, synthetic resin, or the like. Has been. The inner annular portion 40 engages with an annular groove 46 formed in the drive shaft 16 having a circular cross section. The outer annular portion 42 is fitted to the upper outer periphery of the inner cases 18, 18 of the main body portion 10, and further, when the inner cases 18, 18 are inserted into the outer case 34 from below, The case 34 is sandwiched between the inner circumferential step portion 34A.

  50 is a toothbrush part. The toothbrush portion 50 has a substantially inner cone shape that expands downward, and the lower outer periphery is continuous with the outer peripheral surface of the outer case 34 of the main body 10. A toothbrush 52 is implanted in the upper part of the toothbrush portion 50. In the toothbrush portion 50, the drive shaft 16 can be fitted and fixed from below. The upper end of the drive shaft 16 is a flat plate portion 54.

  Here, the toothbrush part 50 is formed with a split cylinder part 56 opened downward as shown in FIG. 3, and a half body 56A of the cylinder part 56 is fixed by a plurality of radial ribs 58, The other half body 56B returns to the half body 56A direction with elasticity. Around the half body 56B, ribs 60 are formed radially with a gap between the half body 56B.

  The half body 56B is formed with an engaging protrusion 62 toward the inside of the cylindrical portion 56, and the drive shaft 16 is formed with an annular groove 64 into which the protrusion 62 is engaged. Further, a flat plate-like portion 54 of the drive shaft 16 is engaged with the upper portion of the cylindrical portion 56, and the rotation of the toothbrush portion 50 is restricted. For this reason, when the drive shaft 16 is inserted into the cylindrical portion 58 of the toothbrush portion 50, the protrusion 62 is prevented from engaging with the groove 64 and the toothbrush portion 50 is prevented from being pulled out. The toothbrush portion 50 can be extracted from the portion 64.

  Next, the operation of the seal member 38 will be described with reference to FIG. In a free state where the inner annular portion 40 is not fixed to the drive shaft 16, the seal member 38 is at a position indicated by a virtual line 38 </ b> A in FIG. 3. When the seal member 38 is fixed to the annular groove 46 of the drive shaft 16, the reciprocating movable range of the drive shaft 16 is limited by the cam 28 and the cam follower 30 of the drive unit 22, so that the drive shaft 16 shown in FIG. When it is at the bottom dead center (position moved most downward), the inner annular portion 40 of the seal member 38 comes to the maximum deformation position pulled downward as shown in FIG. At this time, an upward restoring force f is generated at the inner annular portion 40 (point A in FIG. 3).

  The restoring force f is generated by the deformation of the seal member 38 regardless of whether the toothbrush portion 50 is attached or detached. When the toothbrush portion 50 is mounted, the upper surface annular portion 44 (point B in FIG. 3) of the seal member 38 comes into contact with the lower surface of the toothbrush portion 50, actually the lower ends of the ribs 58 and 60, and the half body 56B of the cylindrical portion 56 When the protrusion 62 engages with the annular groove 64 of the drive shaft 16, the ribs 58 and 60 press the upper surface annular portion 44 (point B) with the pressing force α.

  This pressing force α acts on the drive shaft 16 so as to separate the annular grooves 46 and 64 from each other, but this force does not act to raise or lower the drive shaft 16. However, due to the deformation of the sealing member 38 due to the pressing force α, an upward (or downward) restoring force kα is generated at the point A with reference to the fixing position of the main body 10 (point C in FIG. 3). Here, k is a constant determined by the shape and material of the seal member 38. Accordingly, the resultant force F = f + kα of the restoring force f and kα acts on the point A. Since the restoring force kα is a restoring force with respect to the force α that crushes the seal member 38, it usually becomes an upward restoring force.

  According to this embodiment, the resultant force F always applies an upward restoring force, that is, a preload, to the drive shaft 16, so that play of the drive shaft 16 due to play of the drive unit 22 can be regulated and noise generation can be prevented. Can do. Further, since the inner annular portion 40 is in close contact with the drive shaft 16 and the outer annular portion 42 is in close contact with the main body portion 10 of the seal member 38, the waterproofness of the main body portion 10 can be ensured. Further, when the toothbrush portion 50 is mounted, a tensile force is always applied between the toothbrush portion 50 and the drive shaft 16 due to the reaction force of the pressing force α, and therefore, rattling between the toothbrush portion 50 and the drive shaft 16, that is, the protrusion 62. And the play with the annular groove 64 can be suppressed, and the generation of noise here can also be prevented.

  FIG. 4 is a partially enlarged sectional view showing another embodiment. In this embodiment, the inner annular portion 40a is pulled up with respect to the free state (imaginary line position) of the seal member 38a and fixed to the drive shaft 16. For this reason, the restoring force f is downward. If the restoring force kα is upward, the restoring forces f and kα are opposite to each other, and the difference between them is the resultant force F.

  In this case, by setting so that | f |> | kα |, a downward restoring force (preload) can always be applied to the drive shaft 16. For this reason, when the toothbrush portion 50 is pressed against the teeth, the pressure acts on the drive shaft 16 in a direction that suppresses play of the drive system, so that noise generation when a large pressure is applied to the toothbrush portion 50 during use is prevented. be able to. In FIG. 4, the same parts as those in FIG.

  FIG. 5 is a partially enlarged cross-sectional view showing another embodiment. In this embodiment, the sealing member 38b has a downward restoring force f as in the embodiment of FIG. 4, and a protrusion 80 is provided on the lower surface of the toothbrush portion 50 (the lower surfaces of the ribs 58 and 60, see FIG. 3). This protrusion 80 is brought into contact with the upper surface of the seal member 38b.

  According to this embodiment, even if the upper surface of the seal member 38b is flat, the projecting portion 80 hits, so the setting of the pressing force α on the seal member 38b of the toothbrush portion 50 can be managed with high accuracy. That is, since the upper surface of the seal member 38a in FIG. 4 is flat, the setting accuracy of the contact position and the contact area with the toothbrush portion 50 is deteriorated, and the set value of the pressing force α tends to be inaccurate, but the seal member 38b in FIG. This eliminates such inconvenience.

  FIG. 6 is a partially enlarged cross-sectional view showing another embodiment. In this embodiment, the upper surface annular portion 44 of the seal member 38c is formed in close contact with the drive shaft 16 so as to stand upward. Therefore, the upper surface annular portion 44 c can be brought into contact with the lower end of the cylindrical portion 56 of the toothbrush portion 50. Since the cylindrical part 56 is divided into two parts divided by the slits in the axial direction, except for the slit part, the upper surface annular part 44c is in contact with the lower surface of the toothbrush part 50 at almost the entire circumference of the lower end of the cylindrical part 56. Therefore, the waterproofness between the drive shaft 16 and the seal member 38c is improved. Further, since the contact area between the upper surface annular portion 44c and the toothbrush portion 50 increases, uneven wear on the upper surface of the seal member 38c can be prevented, and the durability of the seal member 38c can be improved.

  FIG. 7 is a partially enlarged cross-sectional view showing another embodiment. In this embodiment, the seal member 38d does not contact the toothbrush portion 50, and a preload is applied to the drive shaft 16 only by the restoring force f between the inner annular portion 40 and the outer annular portion 42.

  That is, the inner annular portion 40 of the seal member 38d was liquid-tightly fixed to the drive shaft 16 in a state where the inner annular portion 40 was pulled up with respect to the free state (imaginary line position). Therefore, the restoring force f applied to the drive shaft 16 is downward, and the preload F (= f) is also downward. The preload F (= f) changes with the reciprocating motion of the drive shaft 16, but is set to always be in a constant direction within the reciprocating motion range of the drive shaft 16. Therefore, the play of the drive system of the drive shaft can be absorbed to prevent the drive system from generating noise.

Side view of one embodiment of the present invention A partially enlarged cross-sectional view Action diagram of the seal member Action explanatory drawing of the seal member which is other examples Action explanatory drawing of the seal member which is other examples Action explanatory drawing of the seal member which is other examples Action explanatory drawing of the seal member which is other examples

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main-body part 12 Motor 16 Drive shaft 22 Drive part 38, 38a, 38b, 38c, 38d Seal member 40 Inner annular part 42 Outer annular part 44 Upper surface annular part 50 Toothbrush part

Claims (8)

A toothbrush part is detachably attached from above to a drive shaft that protrudes upward from a main body part containing the drive part and is vibrated by the drive part, and a seal member is provided between the opposing surfaces of the main body part and the toothbrush part. In the interposed electric toothbrush device,
The seal member includes an inner annular portion that is liquid-tightly secured to the drive shaft, an outer annular portion that is liquid-tightly secured to the main body portion, and a lower surface of the toothbrush portion that is above the inner and outer annular portions. An electric toothbrush device comprising an upper surface annular portion to be press-contacted, and constantly applying a preload in a fixed direction to the drive shaft in a mounted state of the toothbrush portion.   The seal member has a restoring force f applied to the drive shaft by the relative displacement between the inner annular portion and the outer annular portion when the toothbrush portion is not attached, and the lower surface of the toothbrush portion presses the upper annular portion when the toothbrush portion is attached. The electric toothbrush device according to claim 1, wherein the sum F = f + kα of the pressing force α to be applied to the restoring force kα applied to the drive shaft always applies a preload in a fixed direction to the drive shaft.   The electric toothbrush device according to claim 2, wherein the seal member always applies a downward preload to the drive shaft.   The electric toothbrush device according to claim 3, wherein the restoring force f is downward and the restoring force kα is upward, and the expression | f |> | kα | is established.   The electric toothbrush device according to claim 3, wherein both the restoring force f and the restoring force kα are downward, and the restoring force kα is smaller than the restoring force f.   The electric toothbrush device according to claim 2, wherein the restoring force f is upward, and an upward preload is always applied to the drive shaft.   The electric toothbrush according to claim 1, wherein the drive shaft reciprocates in the axial direction. A toothbrush part is detachably attached from above to a drive shaft that protrudes upward from a main body part containing the drive part and is vibrated by the drive part, and a seal member is provided between the opposing surfaces of the main body part and the toothbrush part. In the interposed electric toothbrush device,
The seal member includes an inner annular portion that is liquid-tightly fixed to the drive shaft, and an outer annular portion that is liquid-tightly fixed to the main body, and the inner annular portion and the outer annular portion are not mounted on the toothbrush portion. An electric toothbrush instrument in which a restoring force f applied to the driving shaft by a relative displacement between the two and the driving force always applies a preload in a certain direction to the driving shaft in a mounted state of the toothbrush portion.

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