JP6785607B2 - Drive device - Google Patents

Description

The present invention relates to a drive device.

Conventionally, in toilets, trash cans, and the like, a drive device has been used to automatically open and close the lid. For example, the drive device includes a drive source such as a motor, a gear that transmits the output of the drive source to the output shaft, an output shaft, and the like, and rotates the output shaft coupled with the lid by the output of the drive source. Then, the lid is opened and closed automatically.

Japanese Unexamined Patent Publication No. 7-116084

By the way, in the above-mentioned driving device, an elastic body such as a spring is used to assist the driving force related to the opening and closing of the lid. For example, the output shaft is provided with a spring that urges the lid to rotate in the opening direction (the direction in which the lid is rotated against gravity), so that the driving force applied to the opening and closing of the lid is assisted. Further, as such a drive device, a drive device provided with a plurality of springs with respect to the output shaft is also known in order to further increase the urging force. Here, in recent years, there has been a demand for a thinner drive device while maintaining an urging force due to restrictions on the arrangement location of the drive device.

The present invention has been made in view of the above, and an object of the present invention is to provide a drive device that can be formed thinner while maintaining an urging force.

In order to solve the above-mentioned problems and achieve the object, the drive device according to one aspect of the present invention includes a gear group that rotates by the output of the drive source and a shaft that rotates by the torque transmitted through the gear group. A portion, a first elastic body that urges the shaft portion in the rotational direction, and a gear that meshes with a gear in the previous stage of a gear formed on the shaft portion among the gears included in the gear group. It includes a second elastic body that assists the rotation of the shaft portion in the rotation direction by urging a gear different from the gear that transmits the output of the drive source to the shaft portion .

According to one aspect of the present invention, it can be formed thinner while maintaining the urging force.

FIG. 1 is a side view showing a toilet seat and a toilet lid of a toilet bowl provided with a drive device according to the first embodiment. FIG. 2 is a perspective view showing the outer shape of the drive device according to the first embodiment. FIG. 3A is a top view showing the drive device according to the first embodiment. FIG. 3B is a bottom view showing the drive device according to the first embodiment. FIG. 4 is a perspective view showing a drive device according to the first embodiment. FIG. 5 is a perspective view showing a drive device according to the first embodiment. FIG. 6A is a diagram for explaining braking by the braking unit according to the first embodiment. FIG. 6B is a diagram for explaining braking by the braking unit according to the first embodiment. FIG. 7 is a diagram for explaining the sensor gear unit according to the first embodiment. FIG. 8A is a diagram showing the results of simulation in the drive device according to the first embodiment. FIG. 8B is a diagram showing the results of simulation in the drive device according to the first embodiment.

Hereinafter, the drive device according to the embodiment will be described with reference to the drawings. The relationship between the dimensions of each element in the drawing, the ratio of each element, and the like may differ from the reality. Even between drawings, there may be parts with different dimensional relationships and ratios.

(First Embodiment)
First, an application example of the drive device according to the present embodiment will be described. The drive device according to the present embodiment is applied to various devices having a lid, and automatically opens and closes the lid. For example, a drive device is provided in a toilet, a trash can, a washing machine, etc., and automatically opens and closes a toilet seat, a toilet lid, a trash can lid, a washing machine lid, and the like. Hereinafter, an example of application of the drive device to the toilet will be described with reference to FIG. FIG. 1 is a side view showing a toilet seat and a toilet lid of a toilet bowl including the drive device 100 according to the first embodiment. As shown in FIG. 1, the toilet bowl 2 includes two drive devices 100 in a casing 3 provided at one end on the upper surface side of the base 6. The two drive devices 100 automatically open and close either the toilet seat 4 or the toilet lid 5, respectively.

For example, one drive device 100 is provided on one end side of both ends of the rotation shaft of the toilet seat 4 attached to the casing 3, and automatically drives the toilet seat 4 by driving a drive source (for example, a motor) described later. Open and close. Further, for example, another drive device 100 is provided on one end side of both ends of the rotation shaft of the toilet lid 5 attached to the casing 3, and the toilet lid 5 is automatically opened and closed by driving the drive source. In the example shown in FIG. 1, the case where the two drive devices 100 are provided in the same direction is shown, but the two drive devices 100 may be provided at the opposite ends. The details of the automatic opening and closing of the toilet seat 4 and the toilet lid 5 by the drive device 100 will be described later.

Next, the outer shape of the drive device 100 will be described with reference to FIG. FIG. 2 is a perspective view showing the outer shape of the drive device 100 according to the first embodiment. As shown in FIG. 2, the drive device 100 is formed by projecting the output shaft 21 of the shaft portion 20 from the housing 10. The housing 10 houses each configuration such as a drive source (for example, a motor), a gear group, and a shaft portion 20 (not shown) in an internal space. Here, the housing 10 is formed so that the thickness of the shaft portion 20 in the axial direction is reduced. Then, the drive device 100 transmits torque from a drive source (not shown) to the lid by attaching the output shaft 21 to a mechanism for attaching the output shaft 21 provided on the lid of a toilet, a trash can, a washing machine, or the like. Rotate (open and close) the lid. For example, when the toilet bowl 2 shown in FIG. 1 is provided, the two drive devices 100 are provided in the casing 3 so that the axial direction of the shaft portion 20 coincides with the axial direction of the rotation shafts of the toilet seat 4 and the toilet lid 5. Be prepared. Then, the output shaft 21 of one drive device 100 is attached to the attachment mechanism provided at one end of the rotation shaft of the toilet seat 4. Further, the output shaft 21 of the other drive device 100 is attached to an attachment mechanism provided at one end of the rotation shaft of the toilet lid. That is, the drive device 100 formed so that the thickness corresponding to the axial direction of the rotation shafts of the toilet seat 4 and the toilet lid 5 becomes thin is attached to the toilet bowl 2. Then, the two drive devices 100 automatically open and close the toilet seat 4 and the toilet lid 5 by transmitting the torque from the drive source to the rotation shafts of the toilet seat 4 and the toilet lid 5.

Next, the configuration of the drive device 100 will be described with reference to FIGS. 3A to 5. FIG. 3A is a top view showing the drive device 100 according to the first embodiment. Note that FIG. 3A shows a diagram in which the surface on which the output shaft 21 protrudes is used as the upper surface and the upper surface of the housing 10 is removed. FIG. 3B is a bottom view showing the drive device 100 according to the first embodiment. Note that FIG. 3B shows a diagram in which the surface opposite to the surface on which the output shaft 21 protrudes is set as the lower surface and the lower surface of the housing 10 is removed. 4 and 5 are perspective views showing the drive device 100 according to the first embodiment. Note that FIG. 4 shows a perspective view when the drive device 100 is viewed from the lower surface side except for the housing 10. Further, FIG. 5 shows a perspective view when the drive device 100 is viewed from the upper surface side except for the housing 10.

The drive device 100 includes a shaft unit 20, a motor 31, a shaft conversion unit 40, a first gear unit 50, a second gear unit 60, an assist gear unit 70, a sensor gear unit 80, and a braking unit 90. Has. For example, in the drive device 100, the output shaft 21 of the shaft portion 20 is projected to the outside of the housing 10, and the shaft portion 20, the motor 31, the shaft conversion unit 40, the first gear portion 50, the second gear portion 60, and the assist gear The unit 70, the sensor gear unit 80, and the braking unit 90 are housed in the housing 10. The shaft conversion unit 40, the first gear unit 50, the second gear unit 60, and the assist gear unit 70 are collectively referred to as a gear group.

As shown in FIG. 3A, the motor 31 functions as a drive source / power source for rotating the lid to which the drive device 100 is attached. A drive signal is supplied to the motor 31 from a controller (not shown) via a lead wire (not shown). Further, the output rotation shaft 32 of the motor 31 is rotated by the supply of the drive signal. The motor 31 is not particularly limited, such as a DC motor, a DC brushless motor, and a stepping motor.

A worm 33 is attached to the tip of the output rotating shaft 32 of the motor 31. That is, the worm 33 rotates about the rotation axis of the motor 31 which is a drive source. For example, the worm 33 is a worm in a worm gear. The worm 33 is a screw-shaped gear formed in a cylindrical shape. For example, as the worm 33, three worms are used. Further, for example, the worm 33 may be formed of metal, resin, or the like. Any material may be used for the worm 33 as long as it satisfies predetermined conditions such as strength.

As shown in FIGS. 3A to 4, the shaft conversion unit 40 has a worm wheel 41 and a gear 42. The worm wheel 41 and the gear 42 rotate with their axes aligned with each other around the shaft rod. The worm wheel 41 of the shaft conversion unit 40 meshes with the worm 33. That is, the worm wheel 41 of the axis conversion unit 40 functions as a worm wheel for the worm 33.

For example, in FIG. 3A, the output rotation shaft 32 of the motor 31 extends in the left-right direction. On the other hand, the shaft rod of the shaft conversion unit 40 is orthogonal to the output rotation shaft 32 of the motor 31. For example, the axial direction of the output rotating shaft 32 of the motor 31 is orthogonal to the axial direction of the rotating shaft of the shaft conversion unit 40. In this way, the shaft conversion unit 40 converts the rotating shaft that transmits the driving force of the motor 31 from the output rotating shaft 32 of the motor 31 to the rotating shaft of the shaft conversion unit 40.

As shown in FIGS. 3A and 3B, the first gear portion 50 is a member for transmitting the torque transmitted from the motor 31 to the second gear portion 60 via the shaft conversion unit 40. The first gear portion 50 is formed of metal, resin, or the like, and has a first large-diameter gear 51 and a first small-diameter gear 52 coaxially fixed to the first large-diameter gear 51. The first large-diameter gear 51 meshes with the gear 42 of the shaft conversion unit 40. The first small-diameter gear 52 is formed to have a smaller diameter than the first large-diameter gear 51, rotates along the axis with the first large-diameter gear 51, and transmits the torque transmitted from the motor 31 to the second gear portion 60. .. The first large-diameter gear 51 and the first small-diameter gear 52 of the first gear portion 50 may be integrally formed.

As shown in FIGS. 3A to 5, the second gear portion 60 is a member for transmitting the torque transmitted from the motor 31 to the shaft portion 20 and the assist gear portion 70 via the first gear portion 50. The second gear portion 60 has a second large-diameter gear 61 formed of metal, resin, or the like, and a second small-diameter gear 62 coaxially fixed to the second large-diameter gear 61. The second large-diameter gear 61 meshes with the first small-diameter gear 52 of the first gear portion 50. The second small-diameter gear 62 is formed to have a smaller diameter than the second large-diameter gear 61, rotates with the axis aligned with the second large-diameter gear 61, and the torque transmitted from the motor 31 to the shaft portion 20 and the assist gear portion 70. To convey. The second large-diameter gear 61 and the second small-diameter gear 62 of the second gear portion 60 may be integrally formed.

As shown in FIGS. 3A to 5, the shaft portion 20 is a member for transmitting the torque transmitted from the motor 31 to a lid (for example, a toilet seat and a toilet lid, a trash can and a washing machine lid). is there. For example, the shaft portion 20 is rotated by a motor 31 which is a drive source, and the lid is rotated in a predetermined direction. The shaft portion 20 has an output shaft 21, an output gear 22, and a first spring member 23 (first elastic body). The shaft portion 20 is formed in a columnar shape, an output shaft 21 is formed at one end in the axial direction, and an output gear 22 is formed at the other end in the axial direction. The output shaft 21 is formed in a shape in which a tip portion is partially cut out. Further, the mechanism for attaching the tip end portion of the output shaft 21 provided on the lid allows the output shaft 21 to be attached to the lid, so that the torque from the motor 31 is transmitted to the lid and the lid rotates. The output gear 22 is provided in the circumferential direction of the shaft portion 20 and meshes with the second small diameter gear 62 of the second gear portion 60. As a result, torque is transmitted from the second gear portion 60 to the shaft portion 20.

Here, the shaft portion 20 has an internal space along the axial direction, and the first spring member 23 is arranged. The first spring member 23 is formed in a coil shape and is arranged in the internal space of the shaft portion 20. For example, the first spring member 23 is a so-called assist spring, and a torsion spring (torsion spring) is used. The first spring member 23 urges the shaft portion 20 in one direction in the rotation direction by engaging with the housing 10 and the shaft portion 20, respectively, and the details will be described later.

As shown in FIGS. 3A to 5, in the assist gear portion 70, the assist gear 71 is formed in the circumferential direction of one end of the shaft rod. The assist gear 71 meshes with the second small diameter gear 62 of the second gear portion 60. That is, the assist gear unit 70 rotates with the shaft rod as the rotation shaft by the torque transmitted from the motor 31. Here, the assist gear portion 70 has an internal space along the axial direction on the assist gear 71 side, and the second spring member 72 (second elastic body) is arranged. The second spring member 72 is formed in a coil shape and is arranged in the internal space of the assist gear portion 70. For example, the second spring member 72 is a so-called assist spring, and a torsion spring is used. The second spring member 72 urges the assist gear portion 70 in one direction of rotation by engaging with the housing 10 and the assist gear portion 70, respectively, and details of this will be described later. Further, as shown in FIG. 5, the assist gear portion 70 is provided with a protrusion 73 and acts on the braking portion 90 as the assist gear portion 70 rotates. The details of this will be described later.

As shown in FIGS. 3B and 4, the sensor gear portion 80 includes a first sensor gear 81 (first gear) and a second sensor gear 82 (second gear) in the circumferential direction of one end of the shaft rod. Are formed so as to be overlapped with each other, and a rotation resistor (potency meter) 83 for detecting the rotation angle of the output gear 22 is arranged according to the rotation of the first sensor gear 81 and the second sensor gear 82. The first sensor gear 81 and the second sensor gear 82 mesh with the output gear 22 of the shaft portion 20, respectively, and rotate with the shaft rod as a rotation shaft by the torque transmitted from the motor 31. The rotation resistor 83 outputs the resistance values corresponding to the rotation angles of the first sensor gear 81 and the second sensor gear 82 to a controller (not shown), thereby transmitting the rotation angle of the output gear 22 to a controller (not shown). The controller that receives the rotation angle of the output gear 22 controls the motor 31 by supplying a drive signal to the motor 31. For example, the controller controls the output of the motor 31 so that the lid is in the open or closed state. Here, the first sensor gear 81 and the second sensor gear 82 are rotationally urged in opposite directions by a spring member (not shown), and the details will be described later.

As shown in FIGS. 3A to 5, the braking portion 90 includes a braking lever 91 and a third spring member 92 (urging member). The braking lever 91 has a shaft formed by forming a lever that is acted on by the protrusion 73 of the assist gear portion 70 at one end of the shaft rod and receiving the pushing force of the protrusion 73 accompanying the rotation of the assist gear portion 70 by the lever. Rotate with the rod as the axis of rotation. The third spring member 92 is formed in a coil shape and is arranged at a position through which the shaft rod of the braking lever 91 is inserted. For example, the third spring member 92 is a so-called assist spring, and a torsion spring is used. The third spring member 92 urges the braking lever 91 in one direction of rotation by engaging with the housing 10 and the braking lever 91, respectively, and the details will be described later.

The configuration of the drive device 100 has been described above. Next, the operation of the drive device 100 will be described. In the drive device 100, for example, when the lid is opened, a controller (not shown) supplies a drive signal to rotate the motor 31 in one direction. Due to the rotation of the motor 31, the worm 33 mounted on the output rotation shaft 32 rotates, and the worm wheel 41 meshing with the worm 33 rotates. Further, as the worm wheel 41 rotates, the gear 42 rotates, and the first large-diameter gear 51 meshing with the gear 42 rotates.

Along with the rotation of the first large-diameter gear 51, the first small-diameter gear 52 rotates, and the second large-diameter gear 61 that meshes with the first small-diameter gear 52 rotates. Further, as the second large-diameter gear 61 rotates, the second small-diameter gear 62 rotates, and the output gear 22 that meshes with the second small-diameter gear 62 rotates. Then, as the output gear 22 rotates, the output shaft 21 rotates and the lid opens. On the other hand, when closing the lid, the controller rotates the motor 31 in the reverse rotation. In this case, the rotational force of the rotation opposite to the above-mentioned rotation is transmitted to the output shaft 21 to close the lid.

Here, the drive device 100 has the second spring member 72 in the assist gear portion 70 in addition to the first spring member 23 in the shaft portion 20, so that the drive device 100 can be formed thin while maintaining the urging force. To do. That is, the drive device 100 urges the first spring member 23 that urges the shaft portion 20 in the rotational direction, and the assist gear 71 that rotates on a rotation shaft different from the shaft portion 20 among the gears included in the gear group. By having the second spring member 72 that assists the rotation of the shaft portion 20 in the rotation direction, it is possible to reduce the thickness of the device while maintaining the urging force against the rotation of the output shaft 21 when the lid is opened. To do.

For example, in the drive device 100, the first spring member 23 urges the rotation of the output shaft 21 corresponding to the direction in which the lid is opened. Further, the second spring member 72 urges the rotation of the assist gear 71 corresponding to the direction in which the lid is opened. That is, the assist gear 71 that meshes with the second small-diameter gear 62, which is the front gear of the output gear 22, rotates in the direction in which the lid opens in the same direction as the output gear 22. Therefore, the second spring member 72 urges the assist gear 71 to rotate in the same direction as the rotation in the direction in which the lid of the output gear 22 opens. In this way, the second spring member 72 urges the assist gear 71 to assist the rotation of the second small diameter gear 62 that meshes with the assist gear 71 in the opening direction, and further, the lid of the output gear 22. The rotation in the opening direction will be assisted.

In a drive device used to automatically open and close the lid, a large load torque is applied when the lid is opened from the closed state. Therefore, it is conceivable to reduce the load torque by arranging a spring or the like that urges the rotation corresponding to the direction in which the lid of the output shaft opens. However, when a larger spring is arranged on the output shaft or a plurality of springs are arranged on the output shaft in order to obtain a larger urging force, the drive device becomes larger (the thickness of the device increases). It will be.

However, like the drive device 100, a plurality of springs are rotationally urged to an assist gear 71 which has a rotation shaft different from that of the shaft portion 20 and can transmit the urging force to the output gear 22. It is possible to reduce the thickness of the drive device 100 (suppress the increase in thickness) while maintaining the urging force when the drive device 100 is arranged. Here, the urging by the second spring member 72 not only assists in the direction in which the lid opens, but also assists in the direction in which the lid closes. When the lid is closed, the output shaft 21 rotates in the direction opposite to the rotation in the opening direction. That is, when the lid is closed, the output shaft 21 rotates in the direction opposite to the urging direction of the first spring member 23, and the rotational force is transmitted to the assist gear 71 via the output gear 22 and the second small diameter gear 62. Will be done. Here, the rotation direction of the rotation transmitted to the assist gear 71 is opposite to the opening direction of the lid, and is opposite to the urging direction of the second spring member 72. Therefore, the second spring member 72 exerts a braking effect when the lid is closed by urging the second spring member 72 in the direction opposite to the rotation in the direction in which the lid is closed.

The assist gear portion 70 is arranged so as to mesh with the second small diameter gear 62 in the front stage of the shaft portion 20 in order to efficiently transmit the urging force of the second spring member 72 to the output gear 22. The embodiment is not limited to this, and for example, the assist gear portion 70 may be arranged at an arbitrary position of the gear group. Further, the assist gear portion 70 is not a gear that transmits the output of the motor 31 to the shaft portion 20, but the rotation of the shaft portion 20 is assisted by the urging of the second spring member 72 to assist the rotation of the second small diameter gear 62. It is a newly added gear to assist. The second spring member 72 may be arranged not only in the newly added gear but also in the gear that transmits the output of the motor 31 to the shaft portion 20. For example, the second spring member 72 may be arranged in the second gear portion 60 or the first gear portion 50.

Here, the direction in which the second spring member 72 is urged changes according to the position in which it is arranged. For example, when arranged in the second gear portion 60, the second spring member 72 is urged against a rotation in the direction opposite to the rotation corresponding to the direction in which the lid of the output shaft 21 is opened. On the other hand, when arranged in the first gear portion 50, the second spring member 72 is urged against the rotation corresponding to the opening direction of the lid of the output shaft 21. That is, the rotation direction of the second spring member 72 changes according to the number of gears passing through to the output gear 22 formed on the shaft portion 20.

Further, by having the braking unit 90, the driving device 100 makes it possible to apply braking from an arbitrary position in the rotation of the lid in the closing direction. That is, the drive device 100 has a braking unit 90 that brakes the rotation from the first angle to the second angle in the rotation of the gear group, so that the drive device 100 can rotate the lid in the closing direction from an arbitrary position. Braking can be applied.

For example, in the drive device 100, the assist gear 71 is provided with a protrusion 73, and the protrusion 73 rotates with the rotation of the assist gear 71. That is, the protrusion 73 rotates with the rotation of the assist gear 71 when the lid is opened and closed. The braking portion 90 includes a third spring member 92 that biases from a first angle to a second angle, and a protrusion 73 formed on any of the gear groups (for example, a protrusion 73 formed on the assist gear 71). ) Is provided, and the protrusion 73 rotating in the rotation direction corresponding to the closing direction of the lid is urged in the opposite direction to brake the rotation of the lid in the closing direction. .. Further, in the braking portion 90, braking from an arbitrary position is possible by adjusting the rotation angle at which the urging is started in the opposite direction to the protrusion 73.

6A and 6B are diagrams for explaining braking by the braking unit 90 according to the first embodiment. Note that FIG. 6A shows the positional relationship between the braking lever 91 and the protrusion 73 when the lid is open. Further, FIG. 6B shows the positional relationship between the braking lever 91 and the protrusion 73 when the lid is closed. That is, in FIGS. 6A and 6B, when the lid is rotated in the closing direction, the assist gear 71 rotates in the left direction on the paper surface.

For example, when the lid is open, the braking lever 91 is held in the raised state by the urging force of the third spring member 92, as shown in FIG. 6A. Then, when the lid is closed and the protrusion 73 rotates to the left on the paper surface, the braking lever 91 comes into contact with the protrusion 73 at a predetermined position. For example, the protrusion 73 rotates to the left from the position indicated by the dotted circle in the upper right portion in FIG. 6B, and abuts on the braking lever 91 at the position indicated by the dotted circle in the upper left portion in FIG. 6B. Further, the protrusion 73 rotates as the lid rotates in the closing direction until the lid is closed. That is, the braking lever 91 is pressed by the leftward rotation of the protrusion 73, and is pushed down to the position shown in FIG. 6B.

Here, the braking lever 91 is urged in the direction of pushing up the lever by the urging force of the third spring member 92 as described above. That is, the third spring member 92 of the braking lever 91 urges the protrusion 73 in the direction opposite to the closing direction of the lid until the lid is closed after the protrusion 73 comes into contact with the braking lever 91. To do. As a result, the drive device 100 makes it possible to apply braking from an arbitrary position when the lid is rotated in the closing direction. Further, by using the third spring member 92, the braking force can be applied most immediately before the lid, which receives the most load, is closed. That is, the third spring member 92 is acted to be tightened most immediately before the lid is closed, so that the braking force is applied most immediately before the lid, which receives the most load, is closed. Therefore, the drive device 100 can apply an appropriate braking force according to the angle of the lid.

Here, the urging by the third spring member 92 not only brakes in the direction in which the lid closes, but also assists in the direction in which the lid opens. When the lid is opened, the output shaft 21 rotates in the direction opposite to the rotation in the closing direction. That is, when the lid is opened, the protrusion 73 rotates in the forward direction with the urging direction by the third spring member 92. Therefore, the third spring member 92 exerts an assist effect when the lid is opened by rotating the lid in the opening direction and urging the protrusion 73 in the forward direction.

Further, the assist gear 71 is formed so that the gear ratio with the output gear 22 is 1: 1. That is, by forming the assist gear 71 so that the rotation angle of the output gear 22 (the angle of the lid) and the rotation angle of the assist gear 71 match, it is easy to set the braking position depending on the position where the protrusion 73 is attached. Can be adjusted to. For example, when the state where the lid is closed is set to "0 °" and braking is applied from an angle of "40 °", the braking lever is rotated "40 °" in the reverse direction from the position of the protrusion 73 when the lid is closed. The position of the braking lever 91 and the position of the protrusion 73 are adjusted so that the 91 and the protrusion 73 come into contact with each other.

In the above example, the case where the braking portion 90 has the braking lever 91 and the braking lever 91 urged by the third spring member 92 is pressed against the protrusion 73 has been described. However, the embodiment is not limited to this, and for example, the braking unit 90 may not include the braking lever 91. In such a case, the protrusion 73 is brought into contact with the third spring member 92 and pressed in the direction opposite to the urging direction.

Further, in the above-mentioned example, the case where the protrusion 73 is attached to the assist gear 70 has been described. However, the embodiment is not limited to this, and may be attached to other gears. In such a case, the gear to which the protrusion 73 is attached is determined based on the gear ratio with the output gear 22. For example, the protrusion 73 is attached to a gear in which the gear ratio between the attached gear and the output gear 22 is 2: 1. That is, the protrusion 73 is attached to a gear whose rotation associated with opening and closing the lid is less than one rotation.

Further, the drive device 100 has the sensor gear unit 80, which makes it possible to detect an accurate rotation angle of the output shaft 21 (output gear 22). That is, the drive device 100 is based on the rotation of the first sensor gear 81 and the second sensor gear 82 and the first sensor gear 81 and the second sensor gear 82 that mesh with the output gear 22 formed on the shaft portion 20. A rotation resistor 83 for detecting the rotation angle of the output gear 22 formed on the shaft portion 20 is provided, and the first sensor gear 81 and the second sensor gear 82 are rotationally urged in opposite directions by the elastic member. This makes it possible to detect the accurate rotation angle of the output shaft 21.

FIG. 7 is a diagram for explaining the sensor gear unit 80 according to the first embodiment. Note that FIG. 7 is a diagram showing a part of meshing between the first sensor gear 81 and the second sensor gear 82 and the output gear 22. For example, the first sensor gear 81 and the second sensor gear 82 are arranged so as to be overlapped with each other as shown in FIG. Here, by arranging a spring member (not shown) between the first sensor gear 81 and the second sensor gear 82, the first sensor gear 81 and the second sensor gear 82 are rotationally urged in opposite directions, respectively. To. For example, one end of the torsion spring engages with the first sensor gear 81, and the other end engages with the second sensor gear 82 to urge the first sensor gear 81 in one direction of rotation. The second sensor gear 82 is urged in the direction opposite to the rotation direction of the first sensor gear 81.

As a result, the drive device 100 reduces backlash between the sensor gear unit 80 and the output gear 22, and makes it possible to detect an accurate rotation angle of the output shaft 21. For example, in a drive device that opens and closes the lid, an output gear or a sensor gear that synchronizes with the gear in the previous stage is installed, the resistance change of the rotary resistor is detected, and the output shaft is detected and controlled. There is. However, due to the backlash between the output gear and the sensor gear, the accurate rotation position cannot be detected, and hunting may occur especially in the control just before the lid is closed or just before it is opened. .. However, like the drive device 100, the output gear 22 and the two sensor gears (the first sensor gear 81 and the second sensor gear 82) are simultaneously engaged with each other, and a spring member (not shown) is used to engage the first sensor gear. By urging the 81 and the second sensor gear 82 in the reverse rotation direction, the rotation error is eliminated. As a result, since the drive device 100 eliminates the dead zone during the opening / closing control, the control immediately before closing and immediately before opening can be stably performed.

As described above, in the drive device 100 according to the first embodiment, the first spring member 23 urges the rotation of the output shaft 21 corresponding to the direction in which the lid is opened. Further, the second spring member 72 urges the rotation of the assist gear 71 corresponding to the direction in which the lid is opened. Therefore, it is possible to reduce the thickness of the drive device 100 (suppress the increase in thickness) while maintaining the urging force when a plurality of springs are arranged. FIG. 8A is a diagram showing the result of the simulation in the drive device 100 according to the first embodiment. In FIG. 8A, the vertical axis shows the relative load torque (%) under each condition, and the horizontal axis shows the opening / closing angle (deg). Further, in FIG. 8A, the upper graph shows the load torque when neither the first spring member 23 nor the second spring member 72 is arranged, and the middle graph shows the load torque when either one is arranged. The lower graph shows the load torque when both are arranged.

As shown in FIG. 8A, in the drive device 100, by arranging the first spring member 23 and the second spring member 72, the maximum torque at the time of opening and closing can be reduced. Further, in the drive device 100, the assist gear portion 70 is arranged between the output gear 22 and the second small diameter gear 62 by arranging the assist gear portion 70 so as to mesh with the second small diameter gear 62 which is the gear in the front stage of the output gear 22. Backlash can be reduced and the stability of opening / closing operation can be improved. Further, in the drive device 100, the maximum torque at the time of opening and closing can be reduced, and a motor having a smaller torque can be used. Further, in the drive device 100, the torque transmitted by the gear is reduced, so that the strength of the gear can be reduced. As a result, for example, a metal part can be formed by changing it to a resin, and the manufacturing cost can be reduced and the labor for manufacturing can be reduced. Further, in the drive device 100, the reduction ratio can be reduced by reducing the maximum torque, so that the motor 31 and each gear can be miniaturized.

Further, the drive device 100 according to the first embodiment has a third spring member 92 that urges the rotation of the gear group with respect to the rotation from the first angle to the second angle. In the rotation in the closing direction, braking can be applied from an arbitrary position, and control with a more appropriate operation feeling can be realized according to the actual opening / closing operation. Further, in the drive device 100, the maximum torque can be reduced, and the motor 31 and each gear can be miniaturized.

FIG. 8B is a diagram showing the result of the simulation in the drive device 100 according to the first embodiment. In FIG. 8B, the vertical axis shows the relative load torque (%) under each condition, and the horizontal axis shows the opening / closing angle (deg). Further, in FIG. 8B, the upper graph shows the load torque when the third spring member 92 is not arranged, and the lower graph shows the load torque when the third spring member 92 is arranged. As shown in FIG. 8B, in the drive device 100, by arranging the third spring member 92, the maximum torque at the time of opening and closing can be reduced.

When such a drive device 100 is applied to, for example, the toilet bowl 2 shown in FIG. 1, the maximum torque when opening and closing the toilet seat 4 and the toilet lid 5 can be reduced. That is, the first spring member 23 urges the rotation of the output shaft 21 corresponding to the direction in which the toilet seat 4 opens, and the second spring member 72 causes the rotation of the assist gear 71 corresponding to the direction in which the toilet seat 4 opens. By urging the toilet seat 4, the toilet seat 4 is opened from the closed state (the opening / closing angle “0 °” in FIGS. 8A and 8B) in which the bottom surface 411 of the toilet seat 4 is in contact with the contact surface of the base 6. The torque at the start of rotation (torque at the start of lifting the toilet seat 4) when the toilet seat 4 is rotated so as to be in the open state (the state of the opening / closing angle “120 °” in FIGS. 8A and 8B) is reduced. be able to. Further, in the drive device 100, the urging force of the first spring member 23 and the second spring member 72 in the opening direction causes the toilet seat 4 to rotate (rotate in the closing direction) from the open state to the closed state. The load torque can also be reduced. The load torque can also be reduced in the toilet lid 5 to which the drive device 100 is attached in the same manner as described above.

Further, in the above-mentioned drive device 100, the braking unit 90 brakes against the rotation from the first angle to the second angle in the rotation of the gear group, so that the toilet lid 5 rotates in the closing direction. Appropriate braking can be applied to it. For example, when the toilet seat 4 rotates from the open state to the closed state, the drive device 100 applies braking from the time when the angle of the toilet seat 4 becomes "40 °" and smoothly until the toilet seat 4 is closed. It can be rotated. Here, as shown in FIG. 8B, by applying braking from a certain angle, the load torque that gradually increases until the closed state can be sharply reduced. As a result, the drive device 100 can further reduce the maximum torque applied in the closed state. Further, by using the third spring member 92 in the braking unit 90, the braking force in the closed state where the maximum torque is applied can be maximized. That is, since the third spring member 92 exerts a force in the direction opposite to the urging direction as the toilet seat 4 rotates in the closing direction, the third spring member 92 exerts a stronger urging force as it rotates in the closing direction. It will be. Further, in the drive device 100, the load torque applied to the rotation (rotation in the open direction) of the toilet seat 4 from the closed state to the open state can be reduced by the braking force of the braking unit 90. The load torque can also be reduced in the toilet lid 5 to which the drive device 100 is attached in the same manner as described above.

The drive device 100 according to the first embodiment has been described above. The above-described embodiment is merely an example, and the embodiment is not limited to this. For example, in the above-described embodiment, the case where the output of the motor 31 is transmitted to the shaft portion 20 via the shaft conversion unit 40, the first gear unit 50, and the second gear unit 60 has been described. However, the embodiment is not limited to this, and for example, a clutch portion may be arranged between them.

In such a case, for example, instead of the first gear portion 50, when a torque equal to or higher than a predetermined threshold value is applied by an external force from the shaft portion 20 side, the clutch portion suppresses the transmission of the torque to the drive source side. May be placed.

Moreover, the present invention is not limited by the above-described embodiment. The present invention also includes a configuration in which the above-mentioned components are appropriately combined. Further, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

20 Shaft 21 Output shaft 22 Output gear 23 First spring member (first elastic body)
31 Motor 70 Assist gear part 71 Assist gear 72 Second spring member (second elastic body)
73 Protrusion 80 Sensor gear 81 1st sensor gear (1st gear)
82 2nd sensor gear (2nd gear)
83 Rotating resistor 90 Braking part 91 Braking lever 92 Third spring member (urging member)
100 drive device

Claims (2)

A group of gears that rotate according to the output of the drive source,
A shaft portion that rotates by the torque transmitted through the gear group, and
A first elastic body that biases the shaft portion in the rotational direction,
Of the gears included in the gear group, a gear that meshes with a gear in front of the gear formed on the shaft portion and is different from the gear that transmits the output of the drive source to the shaft portion is urged. As a result, the second elastic body that assists the rotation of the shaft portion in the rotation direction and
A drive device equipped with. The first gear and the second gear meshed with the gear formed on the shaft portion,
An elastic member that urges the first gear in the first rotation direction and the second gear in the second rotation direction opposite to the first rotation direction.
The drive device according to claim 1, further comprising a rotation resistor for detecting the rotation angle of the gear formed on the shaft portion based on the rotation of the first gear and the second gear.