JP7231455B2 - Motion conversion mechanism, motor, and wiper motor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a motion conversion mechanism, a motor, and a wiper motor that convert rotational motion of an output shaft into oscillating motion.

As a wiper motor for driving a wiper, for example, the technology described in Patent Document 1 is known. The wiper motor disclosed in Patent Document 1 includes a motor that serves as a drive source, a worm gear provided on the shaft of the motor, a helical gear that meshes with the worm gear, and a crank mechanism that is connected to the helical gear. ing. The wiper blade is connected to a crank mechanism, and is capable of wiping a window glass or the like by the swinging motion of the crank mechanism that operates in conjunction with the rotation of the shaft of the motor.

International Publication No. 2012/029608

In the wiper motor disclosed in Patent Document 1, the gears and crank mechanism may wear out during continued use, and noise may be generated from the gear crank mechanism when the motor is operated in a worn state. In addition, the wiper motor disclosed in Patent Document 1 requires lubricating oil in normal use, and when the lubricating oil is reduced, there is a possibility that noise may be generated from the gear and crank mechanism.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a motion conversion mechanism, a motor, and a wiper motor that can reduce noise generation and wear, and improve durability. do.

A motion conversion mechanism according to one aspect of the present invention includes a first gear that rotates around a first rotation shaft and has a first meshing portion provided on a first side surface portion in a circumferential direction of the first rotation shaft; A second gear that is arranged in a non-contact manner facing the first gear, rotates around a second rotation shaft parallel to the first rotation shaft, and is provided on a second side surface portion in the circumferential direction of the second rotation shaft. and a second gear having a portion, wherein the diameter of a cross section of the first gear taken along a plane perpendicular to the first rotation axis decreases toward the center of the first gear in the direction of the first rotation axis. The first side surface portion has a pair of arcuate recesses recessed toward the first rotation axis in a plan view orthogonal to the first rotation axis, and the second side surface The portion has a rotationally curved surface about the second rotational axis formed along the recessed portion of the first side portion, the first engaging portion and the second engaging portion are magnetic bodies, and the first engaging portion and the second engaging portion are magnetic bodies. One meshing portion includes a first path spirally formed along the circumferential direction of the first rotation shaft and a region continuous with the first path, and the region where the first path is formed In a region on the opposite side of a plane along the radial direction of the shaft and the first gear, a second route is formed spirally so as to be symmetrical with the first route around the plane. The second meshing portion magnetically meshes with the first path and the second path formed in the first meshing portion, and has an arc shape along the circumferential direction of the second side surface portion. A motion conversion mechanism characterized by:

According to the present invention, since the first gear and the second gear are magnetically meshed with each other, the simple structure converts the rotational motion of the first gear in a predetermined direction into the reciprocating rotational motion of the second gear. can do. According to the present invention, since the first meshing portion and the second meshing portion operate without interfering with each other, it is possible to improve quietness, prevent wear of each gear, and extend the life of the gear.

In the above motion conversion mechanism, the first meshing portion is formed such that the first path is spirally formed from one end surface side toward the other end surface side along the first rotating shaft of the first gear, and the A second path is continuous with the first path on the other end surface side, and is spirally formed from the other end surface side toward the one end surface side so as to be symmetrical with the first path with respect to the plane. Further, the second meshing portion may be configured so as to be continuous with the first path on the side of the one end surface and be formed in an annular shape on the curved surface of rotation.

With the above configuration, according to the present invention, as the first gear rotates, the meshing point between the first meshing portion and the second meshing portion moves along the first path and the second path, and the second meshing portion moves along the first path and the second path. The meshing point moves annularly along the second meshing portion. Accordingly, the second gear can reciprocate around the second rotation shaft.

In the motion converting mechanism, the first meshing portion has the first path formed spirally from one end surface side along the first rotating shaft of the first gear toward the central portion, A first magnet having a path continuous with the first path at the central portion and spirally formed from the central portion toward the one end face side so as to be symmetrical with the first path about the plane. A third route that has a route and is spirally formed along the circumferential direction of the first rotation shaft, and a region that is continuous with the third route and in which the third route is formed sandwiches the plane. has a second magnetic path having a fourth path spirally formed so as to be symmetrical with the third path about the plane, and the third path is the The fourth path is spirally formed from the central portion along the first rotation shaft of the first gear toward the other end surface side, and the fourth path is continuous with the third path on the other end surface side, and is connected to the other end surface. The first magnetic path and the second magnetic path have magnetic poles different from each other, and the first magnetic path and the second magnetic path are spirally formed around the plane toward the central portion from the side so as to be symmetrical with the third path, and The second meshing portion includes an arc-shaped fifth path that magnetically meshes with the first magnetic path, and an arc-shaped second path that has a magnetic pole different from that of the fifth path and magnetically meshes with the second magnetic path. 6 paths may be formed on the curved surface of rotation.

With the above configuration, the present invention reverses the magnetic poles of the first meshing portion every half rotation of the first gear, and accordingly the second gear rotates forward or reverse, so that the second gear of the second gear rotates forward. Or the detection of reversal can be facilitated.

In the motion conversion mechanism, the first meshing portion is formed in a spiral shape from the central portion along the first rotating shaft of the first gear toward one end surface, and the second meshing portion A path continues to the first path on the one end surface side and is formed in a spiral shape from the one end surface side toward the central portion so as to be symmetrical with the first path with respect to the plane, a third path having a first magnetic path continuous with the first path in the central portion and spirally formed along the circumferential direction of the first rotating shaft; and continuous with the third path, In an area opposite to the area where the third path is formed with the plane interposed therebetween, a fourth path is formed spirally so as to be plane-symmetrical with the third path around the plane. A second magnetic path is provided, the third path is spirally formed from the central portion along the first rotating shaft of the first gear toward the other end surface side, and the fourth path is the It is continuous with the third path on the other end surface side, and is formed in a spiral shape from the other end surface side toward the central portion so as to be symmetrical with the third path about the plane, and the central portion. , the second meshing portion is formed by an arcuate fifth path that meshes with the first magnetic path and an arcuate sixth path that meshes with the second magnetic path, forming the rotational curved surface It may be configured to be formed in the

With the above configuration, the present invention meshes the first meshing portion and the second meshing portion at two meshing points. Drive torque can be increased.

In the above motion conversion mechanism, the first meshing portion is formed such that the first magnetic path and the second magnetic path have different magnetic poles, and the second meshing portion is formed to have different magnetic poles than the first meshing portion. The fifth path and the sixth path may be formed to have different magnetic poles so as to be magnetically meshed.

With the above configuration, the present invention can increase the driving torque of the motion conversion mechanism by increasing the magnetic attraction force between the first gear and the second gear.

A motor according to an aspect of the present invention is characterized by comprising a rotor that drives the first gear of the motion conversion mechanism.

According to the present invention, since the first gear and the second gear are magnetically meshed with each other, the simple structure converts the rotational motion of the first gear in a predetermined direction into the reciprocating rotational motion of the second gear. can do. According to the present invention, since the first meshing portion and the second meshing portion operate without interfering with each other, it is possible to improve quietness, prevent wear of each gear, and extend the life of the gear.

A wiper motor according to an aspect of the present invention includes a housing that supports the motor and pivotally supports the first gear and the second gear of the motion conversion mechanism; The wiper motor is characterized by comprising a protruding portion that is formed to protrude so as to restrict the wiper motor from rotating beyond an angular range.

With the above configuration, the present invention can operate without interference between the first meshing portion and the second meshing portion, so that quietness can be improved, wear of each gear can be prevented, and the life of the gear can be extended. Furthermore, since the projection restricts the rotational range of the second gear, it is possible to prevent the second gear from stepping out.

According to the present invention, noise generation and wear can be reduced, and durability can be improved.

It is a top view showing composition of a wiper motor concerning an embodiment of the present invention. It is a top view which shows the internal structure of the gear part of a wiper motor. It is a perspective view which shows the structure of a motion conversion mechanism. It is the perspective view seen from the other direction which shows the structure of a motion conversion mechanism. FIG. 4 is a developed view of a first meshing portion of the first gear; It is a front view which shows the structure of a 2nd gear. It is a perspective view which shows operation|movement of a motion conversion mechanism. FIG. 9 is a perspective view showing the configuration of a motion conversion mechanism according to Modification 1; FIG. 9 is a perspective view showing the configuration of a motion conversion mechanism according to Modification 1; FIG. 11 is a perspective view showing the configuration of a motion conversion mechanism according to Modification 2; 14 is another perspective view showing the configuration of the motion conversion mechanism according to Modification 2. FIG. FIG. 11 is a front view showing the configuration of a second gear according to modification 2; FIG. 10 is a diagram showing the operation of a motion conversion mechanism according to Modification 2; FIG. 11 is a front view showing the configuration of a second gear according to modification 3; 14A and 14B are diagrams showing the operation of the motion conversion mechanism according to Modification 3; FIG. It is a front view which shows the structure of the 2nd gear which concerns on another modification. FIG. 11 is a plan view showing the configuration of a second gear according to another modified example; It is a front view which shows the structure of the 2nd gear which concerns on another modification.

A configuration of a fan motor according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the wiper motor 1 is used, for example, as a driving source of a wiper device for wiping the window glass of a vehicle such as an automobile. The wiper motor 1 includes a motor 1A that serves as a drive source, and a gear portion 10 that is driven by the motor 1A to drive the wiper.

The motor 1A is, for example, a general brushed DC motor. The motor 1A includes, for example, a rotor 3 (armature) rotatably supported in a bottomed cylindrical housing 2 . A bottom portion 2A is provided on one side surface of the housing 2, and a bearing B1 for supporting one end surface side of the shaft S of the rotor 3 is attached to the center of the lid of the bottom portion 2A. A partition plate 2B is attached to the other side surface of the housing 2 so as to cover the opening of the housing 2 . A bearing B2 that supports the other end surface of the shaft S of the rotor 3 is attached to the center of the partition plate 2B. A brush holder Z is provided inside the housing 2 to which a plurality of brushes 4 and 5 as electrodes are attached.

A plurality of permanent magnets 8 and 9 are attached to the inner peripheral surface of the housing 2 so as to be aligned in the circumferential direction. The housing 2 and the plurality of permanent magnets 8 and 9 constitute a stator. Inside the plurality of permanent magnets 8 and 9, a rotor 3 is arranged coaxially with the housing 2 with a small gap therebetween so as not to contact them. The rotor 3 is radially provided with a plurality of teeth (not shown) each having a T-shaped cross section when viewed from the axial direction of the shaft S. As shown in FIG. An enamel-coated motor winding is wound around each tooth. As a result, a plurality of armature coils (not shown) (hereinafter also referred to as coils) are radially formed on the rotor 3 when viewed from the axial direction of the shaft S. As shown in FIG.

A cylindrical pedestal 6 is formed concentrically with the shaft S on the other end surface side of the shaft S. As shown in FIG. A commutator (commutator 7 ) consisting of a plurality of segments (not shown) serving as electrodes of each coil is attached to the outer peripheral surface of the base 6 along the curved surface of the outer peripheral surface of the base 6 . The commutator 7 is sandwiched between a plurality of brushes 4 and 5, and at least two segments are in contact with the plurality of brushes 4 and 5.

With such a configuration, when a plurality of brushes 4 and 5 in sliding contact with the commutator 7 are energized, a magnetic field is generated by the current flowing in the coil, and magnetic attraction or magnetic attraction of the rotor 3 generated in the magnetic field formed by the permanent magnets 8 and 9 Magnetic repulsion causes the rotor 3 to rotate. The rotor 3 rotates in a predetermined rotational direction, and a rotational output is output from the other end surface side of the shaft S. As shown in FIG. The shaft S transmits rotational output to the gear portion 10 .

The gear section 10 includes a housing 11 connected to the motor 1A. The housing 11 has a bottomed box-shaped gear housing 11A having an opening, and a cover member 11B that closes the opening of the gear housing 11A. The housing 11 includes a motion converting mechanism 13 that converts the rotational output of the motor 1A into a reciprocating rotary motion, and an output direction converting section 40 that converts the output direction of the motion converting mechanism 13. As shown in FIG.

The shaft S is connected to, for example, a motion conversion mechanism 13 configured by a magnetic gear mechanism provided inside the housing 11 to drive the motion conversion mechanism 13 . The motion conversion mechanism 13 includes a first gear 20 that is rotationally driven by the shaft S, and a second gear 30 that reciprocates in conjunction with the rotation of the first gear 20 . The second gear 30 is supported by the shaft S1. The shaft S<b>1 is connected to, for example, the output direction changing portion 40 and outputs the reciprocating rotation of the second gear 30 to the output direction changing portion 40 . A detailed configuration of the motion conversion mechanism 13 will be described later.

The output direction converter 40 includes, for example, a worm gear 41 supported by the housing 11 via a shaft S<b>1 and a rack gear 42 meshing with the worm gear 41 . The worm gear 41 reciprocates in conjunction with the operation of the shaft S1. The worm gear 41 has a cylindrical body 41A. Spiral gear teeth 41B are formed around the trunk portion 41A.

The rack gear 42 is rotatably supported by a shaft S2 that is erected from the cover member 11B of the housing 11 in a direction perpendicular to the rotation axis direction of the shaft S1. The rack gear 42 has a cylindrical body portion 42A rotatably supported by the gear housing 11A of the housing 11 by means of a shaft S2, and a rack portion 42B protruding from the base end of the body portion 42A. The rack portion 42B is formed in the shape of a fan radially expanding from the base end of the body portion 42A toward the outside in the radial direction of the body portion 42A. Gear teeth 42C that mesh with the gear teeth 41B of the worm gear 41 are formed at the tip of the rack portion 42B. 42 C of gear teeth are formed with the number of teeth for the range which reciprocates.

With such a configuration, the rack gear 42 is interlocked with the reciprocating rotation of the worm gear 41 to reciprocate around the rotation axis in the direction orthogonal to the rotation axis direction of the worm gear 41 . Instead of using the rack gear 42 and the worm gear 41, the output direction conversion unit 40 may be formed by a bevel gear, and any device that converts the output in the orthogonal direction may be used.

The reciprocating rotation of the rack gear 42 is output by the trunk portion 42A. The rotation range of the rack gear 42 is regulated by a pair of projecting portions 50 and 51 formed in a cylindrical shape projecting from the cover member 11B of the housing 11 . The pair of protruding portions 50 and 51 abut on the rack gear 42 to restrict the rotation range of the rack gear 42 when the worm gear 41 exceeds a predetermined angular range during reciprocating rotation. As a result of restricting the rotation range of the rack gear 42 by the protrusions 50 and 51, the rotation range of the second gear 30 is restricted. The cross-sectional shape of the protruding portions 50 and 51 is not limited to circular, but may be square or any other shape as long as it can restrict the rotation of the second gear 30 . Moreover, the protrusions 50 and 51 and the second gear 30 may be formed so as to directly restrict the rotation of the second gear 30 .

A body portion 42A of the rack gear 42 protrudes to the outside from a through hole 11C formed in the gear housing 11A of the housing 11 . For example, the proximal end of a wiper arm (not shown) and a link mechanism (not shown) for swinging the wiper arm are connected to the trunk portion 42A. When the first gear 20 rotates, the rack gear 42 rotates and reciprocates accordingly, and the wiper arm swings in conjunction with the movement of the rack gear 42 to wipe the window glass of the vehicle.

Next, the configuration of the motion converting mechanism 13 will be described.

As shown in FIGS. 3 and 4, in the motion conversion mechanism 13, the first gear 20 and the second gear 30 are arranged without contact. The first gear 20 and the second gear 30 are magnetic gears that are magnetically meshed.

The first gear 20 rotates in a predetermined rotational direction with a shaft S (see FIG. 2) as a rotation axis L1 (first rotation axis). A shaft S is press-fitted into the first gear 20 . The shaft S press-fitted into the first gear 20 may be integrated with the shaft S press-fitted into the rotor 3 or may be provided separately for the first gear 20 .

The first gear 20 is rotationally driven in conjunction with the rotation of the rotor 3 . The first gear 20 is a drum body having a side portion 21 formed in a three-dimensional curved shape. The first gear 20 has a substantially circular cross-section along a plane orthogonal to the rotation axis L1, and is formed in an hourglass shape so that the diameter of the cross-section decreases toward the central portion C, which is the center in the direction of the rotation axis L1. ing. A side surface portion 21 of the first gear 20 is formed with a pair of arcuate recesses 21A that are recessed toward the rotation axis L1 when viewed from a direction perpendicular to the rotation axis L1. It is formed into a curved surface matching the shape of the second gear 30 .

Since the first gear 20 is formed in a symmetrical shape in the vertical and horizontal directions, the occurrence of whirling vibration during rotation is suppressed. A side surface portion 21 of the first gear 20 is formed with a first meshing portion 22 . The first meshing portion 22 meshes with the second meshing portion 32 of the second gear 30 as described later. The details of the first meshing portion 22 and the second meshing portion 32 will be described later. A second gear 30 is rotatably arranged adjacent to the first gear 20 . The second gear 30 is a driven gear that rotates in conjunction with the rotation of the first gear 20 . The term "meshing" as used herein refers not only to the state in which the two gears are in contact with each other, but also to the state in which the two gears are attracted to each other by magnetic attraction.

The second gear 30 is provided with a shaft S1 that serves as a rotation axis L2 (second rotation axis) parallel to the rotation axis L1. The shaft S1 is, for example, press-fitted into the second gear 30 and fixed so as not to rotate with respect to the second gear 30 . The shaft S<b>1 rotates in conjunction with the rotation of the second gear 30 . The shaft S1 is rotatably supported by the gear housing 11A of the housing 11. As shown in FIG.

A side surface portion 31 (second side surface portion) of the second gear 30 is formed in a rotationally curved shape around the rotation axis L2 along the concave portion 21A of the side surface portion 21 . The second gear 30 is, for example, spherical. A second meshing portion 32 is formed on the side surface portion 31 of the second gear 30 .

Shaft S1 and shaft S2 are preferably made of, for example, a non-magnetic material, more preferably ceramic or resin material. Since the first meshing portion 22 and the second meshing portion 32, which will be described later, are formed of magnets, they are prevented from being magnetized, and eddy currents are generated when the first gear 20 and the second gear 30 rotate. This is to prevent rotation resistance from occurring.

The second meshing portion 32 faces toward the side surface portion 21 of the first gear 20 so as to mesh with the first meshing portion 22 . The second meshing portion 32 and the first meshing portion 22 are separated from each other.

Next, the first meshing portion 22 and the second meshing portion 32 will be described. The first meshing portion 22 and the second meshing portion 32 are each made of a magnet, for example. The first meshing portion 22 is formed so that the N-pole or S-pole magnetic lines of force appear on the surface. The second meshing portion 32 is formed so that magnetic lines of force opposite to those of the first meshing portion 22 appear on the surface. That is, the magnetic poles of the first meshing portion 22 and the second meshing portion 32 are opposite to each other so that a magnetic attraction force is generated between the first meshing portion 22 and the second meshing portion 32 to mesh. It is formed to be

The side surface portion 21 is formed with a spiral first path 22A extending from the one end surface 23 side toward the other end surface 24 side in the direction of the rotation axis L1. The first path 22</b>A is formed, for example, in a half area (180° area) of the first gear 20 in the circumferential direction of the side surface portion 21 of the first gear 20 . Therefore, the first path 22A is formed with a helical pitch that reaches the other end surface 24 side from the one end surface 23 side when the first gear 20 rotates half a turn.

Continuing with the first path 22A, a second path 22B is spirally formed on the surface of the side portion 21 from the other end surface 24 side toward the one end surface 23 side in the direction of the rotation axis L1. The second path 22B is formed, for example, on the side surface portion 21 of the first gear 20 in the other half area (180° area) different from the area in the circumferential direction of the first gear 20 where the first path 22A is formed. It is Therefore, the second path 22B is formed to have an equal length with a helical pitch opposite to the pitch of the first path 22A reaching the one end surface 23 side from the other end surface 24 side when the first gear 20 rotates half a turn.

A connection portion 22C that connects the first path 22A and the second path 22B is formed in the side surface portion 21 of the first gear 20 on the other end surface 24 side. A connection portion 22D that connects the second path 22B and the first path 22A is formed in the side surface portion 21 of the first gear 20 on the one end surface 23 side.

In the first meshing portion 22, a path belonging to a first region 20A, which is half from the center portion C of the first gear 20 to the one end surface 23 side in the direction of the rotation axis L1, is called a return path portion. A route from C to the other end surface 24 side belonging to the half of the second region 20B is called an outward route portion.

As shown in FIG. 5, the first meshing portion 22 is formed in a V shape when the first gear 20 is developed in a plane from the connecting portion 22C around the rotation axis L1. With such a configuration, when the first gear 20 rotates once, a path is formed that returns from the first path 22A through the second path 22B and back to the first path 22A. In the first meshing portion 22, the first region 20A is formed with a forward path portion that is a V-shaped path. When connecting the connecting portion 22C in FIG. 5, the second region 20B is formed with a return path portion that is an inverted V-shaped path.

The first meshing portion 22 is formed, for example, by packing magnetic powder into grooves along the first path 22A and the second path 22B formed in the side surface portion 21, sintering it, and then magnetizing it. Alternatively, the first engaging portion 22 may be formed by embedding flexible magnets in grooves along the first path 22A and the second path 22B. Also, the magnet may have a plurality of magnet pieces arranged in grooves along the first path 22A and the second path 22B. The first meshing portion 22 is formed so that either the N pole or the S pole appears on the surface.

As shown in FIG. 6, the second meshing portion 32 of the second gear 30 includes a semicircular arc-shaped first path 32A (outward path) and a semicircular arc-shaped second path 32B (return path). have The first path 32A and the second path 32B are formed symmetrically with respect to the orthogonal direction of the rotation axis L2. The first path 32A rotates the second gear 30 around the rotation axis L2 in a certain direction within a predetermined angle range when meshing with the first meshing portion 22 . The second path 32B rotates the second gear 30 around the rotation axis L2 within a predetermined angle range in a direction opposite to that of the first path 32A when meshing with the first meshing portion 22 .

The second meshing portion 32 is formed in an annular shape by combining the first path 32A and the second path 32B. The second meshing portion 32 is formed of a magnet so that the polarity opposite to the magnetic pole of the first meshing portion 22 appears on the side surface portion 31 . The first path 32A corresponds to the forward path portion in the first region 20A of the first meshing portion 22. As shown in FIG. The second path 32B corresponds to the return path portion in the second region 20B of the first meshing portion 22. As shown in FIG.

As a result, a magnetic attractive force acts between the first meshing portion 22 and the second meshing portion 32, and the first meshing portion 22 and the second meshing portion 32 are brought into a meshed state. is drawn to the position closest to the first meshing portion 22 on the side surface portion 21 of the first gear 20 as the first gear 20 rotates, and rotates around the rotation axis L2 (shaft S2). The closest position between the first meshing portion 22 and the second meshing portion 32 is called the meshing point.

In FIG. 6, the second meshing portion 32 has a characteristic meshing point with the first meshing portion 22, which is a first point 32C located at one of the connection portions between the first path 32A and the second path 32B. , a second point 32D located at a portion rotated 90° counterclockwise from the first point 32C, and a portion rotated 90° counterclockwise from the second point 32D, the first path 32A and the second path 32B. and a fourth point 32F located at a portion rotated 90° counterclockwise from the third point 32E.

Next, the operation of the gear portion 10 will be described. As shown in FIG. 7, for example, the center portion C of the first path 22A of the first meshing portion 22 and the first point 32C of the second meshing portion 32 are meshing points (see FIG. 7(1)). Therefore, when the first gear 20 rotates in the direction of the arrow A, the meshing point of the first meshing portion 22 moves along the first path 22A toward the connecting portion 22D. In the second meshing portion 32, the meshing point moves from the first point 32C toward the second point 32D along the first path 32A (see FIG. 6). Accordingly, the second gear 30 rotates in the direction of arrow C opposite to arrow A. The direction of rotation indicated by arrow C is tentatively referred to as the normal rotation direction.

When the first gear 20 continues to rotate in the direction of arrow A and the second gear continues to rotate in the direction of arrow C, the connecting portion 22D of the first meshing portion 22 and the second point 32D of the second meshing portion 32 is the meshing point (see FIG. 7(2)). When the first gear 20 continues to rotate in the direction of the arrow A, the meshing point of the first meshing portion 22 shifts from the connecting portion 22D to the second path 22B and moves along the second path 22B. In the second meshing portion 32, the meshing point moves from the second point 32D toward the third point 32E along the first path 32A (see FIG. 6).

When the first gear 20 continues to rotate in the direction of arrow A and the second gear continues to rotate in the direction of arrow C, the central portion C of the second path 22B and the third point 32E of the second meshing portion 32 The engagement point is reached, and the rotation of the second gear 30 stops momentarily (see (3) in FIG. 7).

As the first gear 20 continues to rotate in the direction of arrow A, the meshing point of the first meshing portion 22 moves along the second path 22B toward the connecting portion 22C. In the second meshing portion 32, the meshing point moves to the second path 32B (see FIG. 6), and the meshing point moves from the third point 32E to the fourth point 32F along the second path 32B. Accordingly, the second gear 30 rotates in the direction of the arrow B opposite to the direction of the arrow C. As shown in FIG. Arrow B is tentatively called a reversal direction.

When the first gear 20 continues to rotate in the direction of arrow A and the second gear continues to rotate in the direction of arrow B, the connecting portion 22C of the first meshing portion 22 and the fourth point 32F of the second meshing portion 32 is the meshing point (see FIG. 7(4)). When the first gear 20 continues to rotate in the direction of the arrow A, the meshing point of the first meshing portion 22 shifts from the connecting portion 22C to the first path 22A and moves along the first path 22A. In the second meshing portion 32, the meshing point moves along the second path 32B from the fourth point 32F of the second meshing portion 32 toward the first point 32C.

When the first gear 20 continues to rotate in the direction of arrow A and the second gear continues to rotate in the direction of arrow C, the central portion C of the first path 22A and the first point 32C of the second meshing portion 32 are meshed. point, and the rotation of the second gear 30 stops momentarily (see (5) in FIG. 7).

That is, the meshing point of the first gear 20 moves along the first meshing portion 22 so as to go around the side surface portion 21 . The meshing point in the second meshing portion 32 moves so as to rotate along the second meshing portion 32 .

As described above, when the first gear 20 continues to rotate in the direction of the arrow A about the rotation axis L1, the second gear 30 interlocks with the first gear 20 and repeats reciprocating rotation about the rotation axis L2. conduct. That is, when the first gear 20 continues to rotate in a certain direction, the second gear 30 is shifted to the first gear 30 if the second meshing portion 32 is meshing with the first meshing portion 22 included in the first region 20A. When the second meshing portion 32 is meshed with the first meshing portion 22 included in the second region 20B, it rotates in the same direction as the rotation direction of the first gear 20. Rotate.

With the above configuration, for example, when the proximal end of the wiper arm (not shown) or the link mechanism (not shown) is connected to the shaft S2 of the housing 11 that outputs the reciprocating rotation of the second gear 30, the first gear 20 rotates. The wiper arm swings to wipe the window glass of the vehicle.

As described above, in the wiper motor 1, the first gear 20 and the second gear 30 are magnetically meshed with the first meshing portion 22 and the second meshing portion 32, so that the wiper motor 1 can rotate the second gear 30 with a simple device configuration. can be rotated back and forth. In the wiper motor 1, since the first meshing portion 22 and the second meshing portion 32 are meshed by a magnetic attraction force, the wear of the gears is prevented, the life of the wiper motor 1 is extended, and the generation of gear noise is also prevented. Further, in the wiper motor 1, since the first meshing portion 22 and the second meshing portion 32 are meshed by magnetic attraction force, it is not necessary to lubricate the wiper motor 1 unlike gears, and dust and the like are less likely to accumulate in the lubricating oil. At the same time, maintenance work can be saved.

Further, since the first meshing portion 22 and the second meshing portion 32 are meshed by the magnetic attraction force, the wiper motor 1 has a very simple configuration of the meshing surfaces. tolerance can be relaxed. In addition, since the wiper motor 1 has a simple structure, the number of parts can be reduced as compared with a device using gears or the like, and miniaturization can be achieved. In addition, the wiper motor 1 has a simple structure, and the movable range of the second gear 30 (output shaft) can be within 180 degrees, so that the manufacturing cost can be reduced.

[Modification 1]
In the above-described embodiment, in the motion converting mechanism 13 of the wiper motor 1, the first meshing portion 22 is formed of a magnet so that the N-pole or S-pole magnetic lines of force appear on the surface, and the second meshing portion 32 is formed of the first meshing portion. It was made of magnets so that lines of magnetic force of opposite polarity to 22 appeared on the surface. In the gear portion 10 according to the modified example, the first meshing portion 22 and the second meshing portion 32 are formed of magnets so that magnetic lines of force of two poles, the N pole and the S pole, appear on the surface. In the following description, the same names and reference numerals are used for the same configurations as in the above-described embodiment, and redundant descriptions are omitted as appropriate (the same applies hereinafter).

As shown in FIGS. 8A and 8B, in the motion conversion mechanism 13A, when the first gear 20 is divided into the first region 20A and the second region 20B, the first meshing portion 22 included in the first region 20A The path is called a first magnetic pole path X, and the path of the first meshing portion 22 included in the second region 20B is called a second magnetic pole path Y. The first magnetic pole path X is formed of magnets so that the north pole or the south pole appears on the surface. The second magnetic pole path Y is formed of magnets so that the magnetic pole opposite to the first magnetic pole path X appears on the surface.

The first magnetic pole path X is provided with a connecting portion 22C on the one end surface 23 side and a connecting portion 22E at the central portion C of the first gear 20 . The first magnetic pole path X does not necessarily have to be connected at the central portion C.

In the first magnetic pole path X, a first path 22AX is spirally formed in the side portion 21 from the one end surface 23 side toward the central portion C in the direction of the rotation axis L1. The first path 22AX is formed, for example, in a half region (a region of 180°) in the circumferential direction of the first gear 20 on the side surface portion 21 of the first gear 20 . Therefore, the first path 22A is formed with a helical pitch that reaches the central portion C from the one end surface 23 side when the first gear 20 rotates half a turn.

Continuing with the first path 22AX, a second path 22BX is spirally formed on the surface of the side portion 21 from the central portion C toward the one end surface 23 side in the direction of the rotation axis L1. The second path 22BX is formed, for example, on the side surface portion 21 of the first gear 20 in the other half area (180° area) different from the area in the circumferential direction of the first gear 20 where the first path 22AX is formed. It is Therefore, the second path 22BX is formed to have an equal length with a helical pitch opposite to the pitch of the first path 22A reaching the one end face 23 side from the central portion C when the first gear 20 rotates half a turn.

The second magnetic pole path Y is provided with a connecting portion 22D on the other end surface 24 side, and a connecting portion 22F is formed at the central portion C of the first gear 20. As shown in FIG. The two magnetic pole paths Y do not necessarily have to be connected at the central portion C.

In the second magnetic pole path Y, a first path 22AY is spirally formed in the side portion 21 from the other end surface 24 side toward the central portion C in the direction of the rotation axis L1. The first path 22AY is formed, for example, in a half area (180° area) of the first gear 20 in the circumferential direction on the side surface portion 21 of the first gear 20 . Therefore, the first path 22AY is formed with a spiral pitch that reaches the central portion C from the one end surface 23 side when the first gear 20 rotates half a turn.

Continuing with the first path 22AY, a second path 22BY is spirally formed on the surface of the side portion 21 from the central portion C toward the other end surface 24 in the direction of the rotation axis L1. The second path 22BY is formed, for example, on the side surface portion 21 of the first gear 20 in the other half area (180° area) different from the area in the circumferential direction of the first gear 20 where the first path 22AY is formed. It is Therefore, the second path 22BY is formed to have an equal length with a helical pitch opposite to the pitch of the first path 22AY reaching the other end surface 24 side from the center portion C when the first gear 20 rotates half a turn.

22 C of connection parts and the connection part 22D are formed symmetrically with respect to the rotating shaft L1, seeing from the direction orthogonal to the rotating shaft L1. An overlap section V is formed in the central portion C of the first gear 20 so that the connection portion 22C and the connection portion 22D overlap each other in the direction of the rotation axis L1.

With such a configuration, a magnetic attractive force acts between the first meshing portion 22 and the second meshing portion 32, and the first meshing portion 22 and the second meshing portion 32 form a magnetic gear that meshes with magnetic force. .

The second gear 30 is formed of magnets so that a first path 32A corresponding to the first magnetic pole path X has a magnetic pole opposite to that of the first magnetic pole path X, and a second path 32B corresponding to the second magnetic pole path Y It is formed of a magnet so as to have a magnetic pole opposite to that of the second magnetic pole path Y. When the first gear 20 continues to rotate in a certain direction, the first gear 20 further rotates after the central portion C of the first gear 20 becomes the meshing point between the first meshing portion 22 and the second meshing portion 32. In this case, the magnetic poles at the meshing point between the first meshing portion 22 and the second meshing portion 32 are reversed. The operation of the motion converting mechanism 13A is the same as that of the gear section 10. FIG.

When the first gear 20 continues to rotate in a certain direction, the second gear 30 rotates if the second meshing portion 32 meshes with the first magnetic pole path X included in the first region 20A. When the second meshing portion 32 meshes with the second magnetic pole path Y included in the second region 20B, it rotates in the direction opposite to the rotating direction of the first gear 20. . According to the motion conversion mechanism 13A, in the first meshing portion 22, the first magnetic pole path X and the second magnetic pole path Y for swinging and rotating the second gear 30 are formed of magnets having opposite magnetic poles. , a magnetic sensor or the like can easily detect forward or reverse rotation. Further, when the direction of rotation of the second gear 30 is reversed, a step-out occurs temporarily. can be easily detected.

[Modification 2]
In the above-described embodiment and modification 1, basically, the meshing point between the first meshing portion 22 and the second meshing portion 32 is formed so as to be magnetically attracted by a pair of magnetic poles, the N pole and the S pole. . The engagement point is not limited to this, and may be magnetically attracted by more magnetic poles.

As shown in FIGS. 9 and 10, in the motion conversion mechanism 13B, when the first gear 20 is divided into the first region 20A and the second region 20B, the first region 20A has the first meshing portion 22. A first magnetic pole path P is formed, and a second magnetic pole path Q of the first meshing portion 22 is formed in the second region 20B. The first magnetic pole path P is formed of magnets so that the north pole or the south pole appears on the surface. The second magnetic pole path Q is formed of a magnet so that the magnetic pole opposite to the first magnetic pole path X appears on the surface.

In the first magnetic pole path P, a first path 22G and a second path 22H are formed. The first path 22G is spirally formed from the one end surface 23 side along the rotation axis L1 to the center portion C toward the other end surface 24 side. The second path 22H is formed continuously with the first path 22G in the central portion C. As shown in FIG. The second path 22H is spirally formed from the central portion C toward the one end face 23 side with a pitch opposite to that of the first path 22G. The first path 22G and the second path 22H are formed continuously at the connection point 22X closest to the one end face 23. As shown in FIG.

The second magnetic pole path Q is formed with a third path 22I and a fourth path 22J. The third path 22I is spirally formed from the other end surface 24 side along the rotation axis L1 to the central portion C toward the one end surface 23 side. The fourth path 22J is formed continuously with the third path 22I in the central portion C. As shown in FIG. The fourth path 22J is spirally formed from the central portion C toward the other end surface 24 with a pitch opposite to that of the third path 22I. The third path 22I and the fourth path 22J are formed continuously at the connection point 22Y that is closest to the other end surface 24 .

The second path 22H is formed continuously with the first path 22G at the central portion C. As shown in FIG. That is, the third path 22I is formed symmetrically with the first path 22G with respect to a plane that passes through the central portion C and is orthogonal to the rotation axis L1. The first magnetic pole path P is formed symmetrically with the second magnetic pole path Q with respect to a plane passing through the central portion C and perpendicular to the rotation axis L1.

Hereinafter, in the central portion C, the portion where the connecting portion of the first route 22G and the second route 22H and the connecting portion of the third route 22I and the fourth route 22J are closest to each other will be referred to as a starting point W for convenience.

As shown in FIG. 11 , the second meshing portion 32 is formed on the side surface portion 31 of the second gear 30 when the second meshing portion 32 is viewed from the direction perpendicular to the rotation axis L2 from the front. The second meshing portion 32 is formed with an arcuate fifth path 32P that meshes with the first magnetic pole path P included in the first region 20A. Further, the second meshing portion 32 is formed with an arcuate sixth path 32Q that meshes with the second magnetic pole path Q included in the second region 20B. The sixth path 32Q is formed symmetrically with the fifth path 32P with respect to the orthogonal direction of the rotation axis L2. The fifth path 32P and the sixth path 32Q are combined to form the second meshing portion 32 in an annular shape.

When the second meshing portion 32 is viewed from the front in the direction orthogonal to the rotation axis L2, the second meshing portion 32 has a first point at a portion where the fifth path 32P and the sixth path 32Q are connected at one end on the left side. 32R, a second point 32S located at a portion rotated 90° counterclockwise from the first point 32R, a third point 32T located at a portion rotated 90° counterclockwise from the second point 32S, and a fourth point 32U positioned at a portion rotated 90° counterclockwise from the third point 32T.

Next, operation of the motion conversion mechanism 13B will be described. As shown in FIG. 12(1), when the first gear 20 rotates in the direction of the arrow A from the state where the start point W of the first gear 20 and the first point 32R of the second gear 30 are meshed, the The second gear 30 is interlocked with the first gear 20 and rotates in the direction of arrow C, which is the direction of rotation opposite to that of the first gear 20 . When the first gear 20 rotates in the direction of arrow A by 180°, the second gear 30 rotates in the direction of arrow C by 90°, and in the first magnetic pole path P, the connection point 22X and the second point 32S of the second meshing portion 32 are connected. are meshed, and the connection point 22Y and the fourth point 32U of the second meshing portion 32 are meshed in the second magnetic pole path Q (see FIG. 12(2)).

When the first gear 20 rotates further 180° in the direction of arrow A, i.e. 360° from the initial state, the second gear 30 rotates further 90° in the direction of arrow C, i.e. 180° from the initial state, and the starting point W meshes with the third point 32T (see FIG. 12(3)). When the first gear 20 further rotates 180° in the direction of arrow A, that is, 540° from the initial state, the second gear 30 rotates (reverses) 90° in the direction of arrow B opposite to arrow C, The connection point 22X and the second point 32S of the second meshing portion 32 mesh on the first magnetic pole path P, and the connection point 22Y and the fourth point 32U of the second meshing portion 32 mesh on the second magnetic pole path Q. (See FIG. 12(4)).

When the first gear 20 rotates further 180 degrees in the direction of arrow A, that is, 720 degrees from the initial state, the second gear 30 rotates further 90 degrees in the direction of arrow B, that is, 180 degrees from the state of FIG. It rotates, the starting point W and the first point 32R are meshed, and the state shown in FIG. 12(1) is restored (see FIG. 12(5)). As described above, when the first gear 20 rotates twice, the second gear 30 reciprocates at a rotation angle of 180 degrees.

In the motion conversion mechanism 13B according to Modification 2 described above, the first magnetic pole path P of the first meshing portion 22 and the fifth path 32P of the second meshing portion 32 mesh, and the second magnetic pole of the first meshing portion 22 Since the path Q meshes with the sixth path 32Q of the second meshing portion 32, the magnetic attraction force becomes stronger than when the first meshing portion 22 and the second meshing portion 32 are formed by one magnetic pole. , the transmission torque between the first gear 20 and the second gear 30 can be improved.

[Modification 3]
In the motion conversion mechanism 13B according to Modification 2, the rotation angle range of the second gear 30 can be changed by adjusting the range in which the second meshing portion 32 is formed on the second gear 30 .

As shown in FIG. 13, the second gear 30 has a right half area compared to the second meshing portion 32 according to the second modification when the second meshing portion 32 is viewed from the direction orthogonal to the rotation axis L2. is formed in That is, the second meshing portion 32 has a fifth path 32P1 formed half as much as the fifth path 32P, and a sixth path 32Q1 half as much as the sixth path 32Q. have

When the second meshing portion 32 is viewed from the direction orthogonal to the rotation axis L2, the second meshing portion 32 rotates 45° clockwise from the first point 32R at the upper end of the sixth path Q1 and the first point 32R. a third point 32T located at a connecting portion between the sixth path Q1 rotated 45° clockwise from the second point 32S and the fifth path 32P1; It has a fourth point 32U located at a portion of the fifth path 32P1 rotated 45° around and a fifth point 32V located at the lower end of the fifth path 32P1 rotated 45° clockwise from the fourth point 32U. .

Next, the operation of the motion conversion mechanism 13C according to Modification 3 will be described. As shown in FIG. 14(1), the connection point 22X and the fifth point 32V of the second meshing portion 32 mesh on the first magnetic pole path P, and the connection point 22Y and the second mesh on the second magnetic pole path Q. When the first gear 20 rotates in the direction of arrow A from the state in which the first point 32R of the portion 32 is meshed, the second gear 30 interlocks with the first gear 20 and rotates in the opposite direction to the first gear 20. Rotate in the direction of directional arrow C. When the first gear 20 rotates in the direction of arrow A by 90°, the second gear 30 rotates in the direction of arrow B, which is the same direction as arrow A, by 45°. The fourth point 32U of the second meshing portion 32 is meshed, and the middle point of the fourth path 22J and the second point 32S of the second meshing portion 32 are meshed in the second magnetic pole path Q (see FIG. 14(2)). ).

When the first gear 20 rotates further 90° in the direction of arrow A, i.e. 180° from the initial position, the second gear 30 rotates further 45° in the direction of arrow C, i.e. 90° from the initial position, The starting point W of the first gear 20 and the third point 32T of the second meshing portion 32 are meshed (see FIG. 14(3)). When the first gear 20 further rotates in the direction of arrow A by 90°, that is, by 270° from the initial state, the second gear 30 rotates (reverses) by 45° in the direction of arrow B opposite to arrow C, In the first magnetic pole path P, the midpoint of the first path 22G and the fourth point 32U of the second meshing portion 32 are meshed, and in the second magnetic pole path Q, the midpoint of the third path 22I and the fourth point of the second meshing portion 32 are meshed. The two points 32S mesh with each other. (See FIG. 14(4)).

When the first gear 20 rotates further 90° in the direction of arrow A, that is, 360° from the initial state, the second gear 30 rotates further 45° in the direction of arrow B, that is, 45° from the state of FIG. 14(4). Rotating, the connection point 22X and the fifth point 32V of the second meshing portion 32 are meshed on the first magnetic pole path P, and the connection point 22Y and the first point 32R of the second meshing portion 32 are meshed on the second magnetic pole path Q. meshes and returns to the state shown in FIG. 14(1) (see FIG. 14(5)). As described above, when the first gear 20 rotates once, the second gear 30 reciprocates at a rotation angle of 90°.

The wiper motor 1 according to Modification 3 described above can adjust the rotation angle range of the second gear 30 by changing the path length of the second gear 30 .

[Other Modifications]
As shown in FIGS. 15 and 16, the second gear 30 may be formed in the shape of a spheroid shaped like a sphere crushed in the direction of the rotation axis L2. Then, the second meshing portion 32 may be formed in an elliptical shape when viewed from the front in the direction orthogonal to the rotation axis L2. With such a configuration, the second meshing portion 32 rotates over a wider angular range than when the second gear 30 is formed in a spherical shape.

Further, as shown in FIG. 17, the second gear 30 is made of a magnet so that the magnetic poles of the second meshing portion 32 become two poles, and the S pole and the N pole appear on the surface side by side along the path. may be formed. Correspondingly, the first meshing portion (not shown) is also formed of a magnet so that the S pole and the N pole appear on the surface in parallel along the path so as to have magnetic poles in the opposite direction to the second meshing portion 32 . may

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design and the like are included within the scope of the gist of the present invention. For example, in the above-described embodiment, the first meshing portion 22 and the second meshing portion 32 are formed of magnets and are magnetically meshed. The meshing portion may be formed in a concave shape (for example, groove shape) and a convex shape (for example, ball shape).

When one of the first meshing portion and the second meshing portion is made of a magnet, the other meshing portion may be made of a magnetic material other than the magnet. Further, the shape of the first gear and the second gear in the above embodiment is an example, and for example, the first gear and the second gear may be formed in a shape combining a cylindrical shape and a conical shape.

DESCRIPTION OF SYMBOLS 1... Wiper motor 1A... Motor 2... Housing 3... Rotors 8, 9... Permanent magnet 10... Gear part 11... Cases 13, 13A, 13B, 13C... Motion converting mechanism 20... First gear 22... First meshing part 30... Second gear 31 Second side surface portion 31 Side surface portion 32 Second meshing portion 40 Output direction converting portion 41 Worm gear 42 Rack gears 50, 51 Protruding portion Z Brush holder

Claims (7)

a first gear that rotates around a first rotation shaft and has a first meshing portion provided on a first side face portion in the circumferential direction of the first rotation shaft;
A second gear that is arranged in a non-contact manner facing the first gear, rotates around a second rotation shaft parallel to the first rotation shaft, and is provided on a second side surface portion in the circumferential direction of the second rotation shaft. a second gear having a meshing portion;
The first gear has an hourglass shape in which the cross-sectional diameter of the plane perpendicular to the first rotation axis decreases toward the center of the first gear in the direction of the first rotation axis. The side surface portion has a pair of arcuate recesses recessed toward the first rotation axis in plan view orthogonal to the first rotation axis,
the second side surface portion has a rotationally curved surface around the second rotation axis formed along the concave portion of the first side surface portion;
The first meshing portion and the second meshing portion are magnetic bodies,
The first meshing portion includes a first path spirally formed along the circumferential direction of the first rotating shaft, and a region continuous with the first path, where the first path is formed. a second path spirally formed to be symmetrical with the first path with respect to the plane on the opposite side of a plane along the radial direction of the one rotation axis and the first gear; has
The second meshing portion magnetically meshes with the first path and the second path formed in the first meshing portion, and has an arc shape along the circumferential direction of the second side surface portion. characterized by
Motion conversion mechanism. In the first meshing portion, the first path is spirally formed from one end surface side to the other end surface side along the first rotating shaft of the first gear, and the second path is formed in a spiral shape along the first rotating shaft of the first gear. It is continuous with the first path on the side of the end surface and is formed in a spiral shape from the side of the other end surface toward the side of the one end surface so as to be symmetrical with the first path about the plane. continuous with the first path on the end face side,
The second meshing portion is formed in an annular shape on the curved surface of rotation,
A motion conversion mechanism according to claim 1 . The first meshing portion is
The first path is spirally formed from one end surface of the first gear along the first rotating shaft toward the central portion, and the second path is continuous with the first path at the central portion. , a first magnetic path formed spirally so as to be symmetrical with the first path about the plane from the central portion toward the one end surface, and
A third path spirally formed along the circumferential direction of the first rotating shaft, and an area continuous with the third path and opposite to the area where the third path is formed across the plane. a second magnetic path having a fourth path spirally formed so as to be symmetrical with the third path about the plane;
the third path is spirally formed from the central portion along the first rotating shaft of the first gear toward the other end surface,
The fourth path is continuous with the third path on the other end surface side, and is spirally formed from the other end surface side toward the central portion so as to be symmetrical with the third path about the plane. is,
The first magnetic path and the second magnetic path have different magnetic poles,
The second meshing portion includes an arc-shaped fifth path that magnetically meshes with the first magnetic path, and an arc-shaped fifth path that has a magnetic pole different from that of the fifth path and magnetically meshes with the second magnetic path. characterized by being formed on the curved surface of rotation by a sixth path,
A motion conversion mechanism according to claim 1 . The first meshing portion is
The first path is spirally formed from the central portion along the first rotating shaft of the first gear toward one end surface side, and the second path is continuous with the first path on the one end surface side. and is formed spirally from the one end face side toward the central portion so as to be symmetrical with the first path around the plane , and is continuous with the first path at the central portion. A third path having a magnetic path and spirally formed along the circumferential direction of the first rotating shaft, and a region continuous with the third path where the third path is formed are the planes A second magnetic path having a fourth path spirally formed so as to be symmetrical with the third path around the plane in the area on the opposite side across the plane,
the third path is spirally formed from the central portion along the first rotating shaft of the first gear toward the other end surface,
The fourth path is continuous with the third path on the other end surface side, and is spirally formed from the other end surface side toward the central portion so as to be symmetrical with the third path about the plane. and is continuous with the third path at the central portion,
The second meshing portion is formed on the rotationally curved surface by an arcuate fifth path that meshes with the first magnetic path and an arcuate sixth path that meshes with the second magnetic path. do,
A motion conversion mechanism according to claim 1 . The first meshing portion is formed such that the first magnetic path and the second magnetic path have different magnetic poles,
The second meshing portion is formed so that the fifth path and the sixth path have different magnetic poles so as to magnetically mesh with the first meshing portion,
5. A motion conversion mechanism according to claim 4. A rotor for driving the first gear of the motion conversion mechanism according to any one of claims 1 to 5,
motor. a housing that supports the motor according to claim 6 and pivotally supports the first gear and the second gear of the motion conversion mechanism;
The wiper motor, wherein the casing includes a projecting portion formed to project so as to prevent the second gear from rotating beyond a predetermined angular range.

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