JP5649381B2 - Wiper motor - Google Patents

Description

  The present invention relates to a wiper motor that converts rotational motion of a rotary shaft into swing motion by a gear mechanism, and swings and drives a wiper member attached to an output shaft between one side reverse position and the other side reverse position.

  2. Description of the Related Art Conventionally, a rear wiper device that wipes a rear glass of a vehicle such as an automobile has a wiper motor that includes a gear mechanism that converts a rotational motion of a rotary shaft into a swing motion. Then, the wiper member attached to the output shaft is driven to swing between the one-side reversal position and the other-side reversal position on the rear glass, thereby wiping rainwater, dust, etc. adhering to the rear glass.

  Such a wiper motor includes a motor case that accommodates a rotating shaft and a gear case that accommodates a gear mechanism, and is formed as one unit by connecting the motor case and the gear case to each other. A reduction mechanism and a motion conversion mechanism that form a gear mechanism are housed inside the gear case, and the reduction mechanism includes a worm that rotates with a rotation shaft and a worm wheel that meshes with the worm. As a result, the rotation of the worm is reduced to a predetermined speed to increase the torque, and the increased torque is output from the worm wheel.

  On the other hand, the motion converting mechanism includes a motion converting member having a sector gear and a connecting portion, an output gear provided on the output shaft so as to be integrally rotatable, and a connecting plate for maintaining meshing between the output gear and the sector gear. The connecting portion of the motion conversion member is rotatably connected to a connecting shaft located away from the rotation center axis of the worm wheel, and the connecting plate is a gear shaft at the center of the sector gear and an output shaft that rotates together with the output gear. Both are rotatably connected. As a result, the motion conversion member swings in accordance with the rotational motion of the worm wheel, and consequently the output gear meshed with the sector gear, that is, the output shaft is driven to swing.

  As a wiper motor provided with such a gear mechanism, for example, a technique described in Patent Document 1 is known. The wiper motor described in Patent Document 1 includes a clutch device coaxially with the output shaft, and the clutch device operates when the load from the wiper blade (wiper member) is large due to, for example, snow or the like. The worm wheel is not transmitted. Thus, the wiper motor can be reduced in size while protecting the internal mechanism (gear mechanism, etc.) of the wiper motor.

JP 2007-302038 A (FIG. 2)

  However, according to the wiper motor described in Patent Document 1 described above, the clutch device is formed by an engagement base, a coil spring, a clutch disk, and an input disk, and these multiple components are arranged coaxially with the output shaft. ing. Therefore, not only the number of parts is increased, but the assembly process is complicated, and the weight of the wiper motor is increased, and further downsizing of the wiper motor is difficult.

  An object of the present invention is to provide a wiper motor that can protect components from a large load with a simple and inexpensive structure without increasing the number of components, and that can meet the needs for downsizing.

The wiper motor of the present invention is a wiper motor that converts the rotational motion of the rotary shaft into a swing motion by a gear mechanism, and swings and drives the wiper member attached to the output shaft between the one-side reverse position and the other-side reverse position. A bottomed gear case that is formed with an opening and accommodates the gear mechanism, a gear cover that closes the opening, an output gear that forms the gear mechanism and is provided so as to be integrally rotatable with the output shaft, A gear tooth provided on the outer peripheral side of the output gear and formed over a substantially half circumference along a circumferential direction of the output gear; a motion converting member that forms the gear mechanism and meshes with the gear tooth; and the output A resin cap that holds the mesh between the gear and the motion conversion member, is provided between the connecting plate provided on the opening side, and between the connecting plate and the gear cover, and is in sliding contact with the inner surface of the gear cover. , A worm wheel that forms the gear mechanism and is rotatably connected to the motion conversion member, a protrusion that is provided in the gear case and projects in the radial direction of the output gear, the gear teeth, A contact surface that is provided so as to be able to contact each other on the protrusion and restricts rotation of the output shaft by a predetermined angle or more, and the contact surface provided on the gear teeth is arranged along the circumferential direction of the output gear. Provided respectively on both ends of the gear teeth, a predetermined gap is formed between the protrusion and each contact surface of the gear tooth, and when the load is applied to the output shaft, each contact surface and the protrusion Are in contact with each other over the entire surface, and the meshing portion of the output gear and the motion converting member and the abutting surface of the protrusion are arranged opposite to each other with the output shaft as a center, and are connected to the output shaft. The output gear when loaded The engagement portion of the spare the motion conversion member, the teeth on the end nearer along the circumferential direction of the output gear and said motion converting member is engaged to said Rukoto.

  The wiper motor of the present invention is characterized in that the protrusion is integrally formed with the gear case.

  According to the wiper motor of the present invention, the gear teeth are provided on the outer peripheral side of the output gear along the circumferential direction of the output gear over a substantially half circumference, and the protrusion that protrudes in the radial direction of the output gear is provided on the gear case. An abutment surface is provided that restricts rotation of the output shaft over a predetermined angle so as to be able to abut against the teeth and the protrusions. As a result, when a large load is applied to the output shaft, the contact surface of the gear teeth and the contact surface of the protrusion are in contact with each other, and the output shaft can be restricted from rotating more than a predetermined angle. At this time, since the contact surface of the protrusion receives a large load, the large load is not transmitted to the other components housed in the gear case. Therefore, the components that form the wiper motor can be protected. In addition, since a large load is not applied to the component parts, it is possible to reduce the weight of the wiper motor by reducing the rigidity of the component parts. Furthermore, since it is only necessary to form contact surfaces on the output gear and the protrusion, the structure can be simplified and inexpensive without increasing the number of parts, the assembly process can be simplified, and the wiper motor can be further downsized. Is possible.

  According to the wiper motor of the present invention, since the protrusion is integrally formed with the gear case, the trouble of assembling the protrusion to the gear case can be saved. Therefore, the assembly process of the wiper motor can be further simplified.

  According to the wiper motor of the present invention, the contact surfaces provided on the gear teeth are provided on both end sides of the gear teeth along the circumferential direction of the output gear, so that output is performed at both the one-side inversion position and the other-side inversion position of the wiper member. Even when a large load is applied to the shaft, the components forming the wiper motor can be protected.

It is explanatory drawing explaining the rocking drive range of the output shaft of the wiper motor which concerns on this invention. It is a top view which shows the detailed structure of the wiper motor of FIG. (A), (b) is explanatory drawing explaining the normal operation state of the output gear which expands and shows the broken-line circle | round | yen A part of FIG. It is operation | movement explanatory drawing when a wiper member exists in a 1st inversion position (stop position). It is operation | movement explanatory drawing when a wiper member exists in a 2nd inversion position.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory view for explaining a swing drive range of an output shaft of a wiper motor according to the present invention, FIG. 2 is a plan view showing a detailed structure of the wiper motor of FIG. 1, and FIGS. FIG. 4 is an explanatory diagram for explaining the normal operation state of the output gear, which is shown by enlarging the broken line circle A of FIG. 2, FIG. 4 is an operation explanatory diagram when the wiper member is in the first reverse position (stop position), and FIG. The operation | movement explanatory drawing in case a wiper member exists in a 2nd inversion position is each represented.

  A wiper motor 10 shown in FIGS. 1 and 2 is used as a drive source of a rear wiper device (not shown) for wiping a rear glass of a vehicle such as an automobile. The wiper motor 10 includes a motor unit 20 that is an electric motor. And a gear portion 30 having a gear mechanism 40. In FIG. 2, the gear cover 32 is omitted in order to explain the internal structure of the gear case 31.

  The motor unit 20 includes a motor case 21 formed into a bottomed cylindrical shape by pressing (deep drawing) a magnetic material such as a steel plate. As shown in FIG. 2, a plurality of permanent magnets 22 (two in the figure) having a substantially arc shape in cross section are fixed inside the motor case 21 so as to face each other. Inside each permanent magnet 22, an armature 24 around which a coil 23 is wound in a predetermined winding manner is rotatably provided, and an armature shaft 25 as a rotating shaft is fixed through the rotation center of the armature 24. ing.

  A cylindrical commutator (commutator) 26 is fixed to a substantially intermediate portion along the axial direction of the armature shaft 25, and the end of the coil 23 is electrically connected to the commutator 26. A pair of brushes 27 are in sliding contact with the outer peripheral portion of the commutator 26, whereby a drive current is supplied to each brush 27 from an in-vehicle controller (not shown), whereby the coil 23 is passed through the commutator 26. Is supplied with a drive current. The supply of drive current to the coil 23 generates a rotational force (electromagnetic force) in the armature 24, so that the armature shaft 25 rotates at a predetermined rotational direction / rotational speed.

  The armature shaft 25 protrudes from the motor case 21 and extends to the inside of the gear case 31 that forms the gear portion 30. A spiral worm 28 (not shown in detail) is integrally provided on the protruding end side of the armature shaft 25, and the worm 28 rotates integrally with the armature shaft 25 by supplying a drive current to the motor unit 20. ing. Here, the worm 28 is formed, for example, by rolling.

  The gear unit 30 includes a bottomed gear case 31, a gear mechanism 40 accommodated in the gear case 31, and a gear cover 32 that closes the opening of the gear case 31. The gear cover 32 has a function as an attachment stay for fixing the wiper motor 10 inside the back door (not shown) of the vehicle. The gear cover 32 has three attachment bolts (not shown) attached thereto. A mounting leg 32a (see FIG. 1) is provided. Here, the gear mechanism 40 accommodated in the gear case 31 is formed of a speed reduction mechanism 41 and a motion conversion mechanism 42.

  The speed reduction mechanism 41 is formed by a worm 28 provided on the armature shaft 25 and a worm wheel 43 rotatably accommodated in the gear case 31. A tooth part 43 a (not shown in detail) is formed on the outer peripheral side of the worm wheel 43, and the tooth part 43 a is engaged with the worm 28. As a result, the rotation of the armature shaft 25 is decelerated to a predetermined speed, and the torque that has been increased in torque is output from the worm wheel 43.

  A rotation center shaft 43b is fixed to the worm wheel 43, and the rotation center shaft 43b passes through the bottom portion 31a of the gear case 31 and is rotatably supported by the bottom portion 31a. A connecting shaft 43c is rotatably provided at a position offset by a predetermined distance radially outward from the rotation center shaft 43b of the worm wheel 43. A connecting portion 45a of the motion converting member 45 is connected to the connecting shaft 43c.

  The motion conversion mechanism 42 includes an output gear 51 fixed to the output shaft 44, a motion conversion member 45, a connecting plate 46, and three resin caps 47, 48, and 49. The motion conversion mechanism 42 converts the rotational motion of the armature shaft 25 into a swing motion via the speed reduction mechanism 41 and transmits it to the output shaft 44 (wiper member).

  The output shaft 44 is formed of a steel round bar, the proximal end side is disposed inside the gear case 31, and the distal end side extends outside the gear case 31. The output shaft 44 is rotatably supported by a boss portion 31b (see FIG. 1) provided integrally with the gear case 31. A rubber seal member 50 is mounted between the output shaft 44 and the boss portion 31 b, and the seal member 50 prevents rainwater, dust, and the like from entering the inside of the gear case 31.

  On the distal end side of the output shaft 44, a serration portion 44a in which a base end side of a wiper arm (not shown) forming a wiper member is fixed so as not to be relatively rotatable, and a base end side of the wiper arm is fixed to the output shaft 44. A male screw portion 44b to which a fixing nut (not shown) is screwed is integrally provided.

  An output gear 51 formed of a sintered material or the like is fixed to the base end side of the output shaft 44 so as to be integrally rotatable. On the outer peripheral side of the output gear 51, gear teeth 51 a are formed along the circumferential direction of the output gear 51 over a substantially half circumference (a range of about 190 °). A first contact surface 51b and a second contact surface 51c as contact surfaces are formed on both ends of the gear teeth 51a along the circumferential direction of the output gear 51. The contact surfaces 51b and 51c can contact substantially the entire surface with the contact surfaces 31d and 31e of the protrusion 31c provided inside the gear case 31, respectively.

  The base end side of the output shaft 44 passes through the central portion of the output gear 51, and one side in the longitudinal direction of the connecting plate 46 is rotatably connected to the portion through which the output shaft 44 passes. A flange-shaped resin cap 47 is attached to the base end portion of the output shaft 44, and the resin cap 47 is in sliding contact with the inner surface of the gear cover 32. The resin cap 47 plays a role of making the relative rotation of the output shaft 44 with respect to the gear cover 32 smooth.

  The motion converting member 45 is formed in a flat plate shape by pressing (punching) a steel plate or the like, and includes a connecting portion 45a and a sector gear 45b. The connecting portion 45 a is disposed near the worm wheel 43 and is fixed to a connecting shaft 43 c that is rotatably provided on the worm wheel 43. That is, the connecting portion 45a is rotatably connected to the worm wheel 43 via the connecting shaft 43c. A hook-shaped resin cap 48 is attached to the connecting shaft 43 c, and the resin cap 48 is configured to slidably contact the inner surface of the gear cover 32. The resin cap 48 plays a role of facilitating relative movement of the connecting shaft 43c with respect to the gear cover 32.

  The sector gear 45 b is a spur gear formed in a substantially sector shape and meshed with the gear teeth 51 a of the output gear 51. A gear shaft 52 is fixed to the axis of the sector gear 45b, and the other end in the longitudinal direction of the connecting plate 46 is rotatably connected to the gear shaft 52. A gear-shaped resin cap 49 is attached to the gear shaft 52, and the resin cap 49 is in sliding contact with the inner surface of the gear cover 32. The resin cap 49 plays a role of facilitating relative movement of the gear shaft 52 with respect to the gear cover 32.

  Between the output shaft 44 and the gear shaft 52, a connecting plate 46 formed in a flat plate shape by pressing (punching) a steel plate or the like is provided. One side and the other side of the connecting plate 46 in the longitudinal direction are swingably connected to the output shaft 44 and the gear shaft 52, respectively, so that the connecting plate 46 engages the gear teeth 51a of the output gear 51 and the sector gear 45b. It comes to hold.

  A protrusion 31c is integrally provided on the output gear 51 side inside the gear case 31, and the protrusion 31c is integrally formed with the gear case 31 when the gear case 31 is formed by, for example, injecting molten aluminum material or the like. The The protrusion 31 c protrudes in the radial direction of the output gear 51, and the tip side thereof is directed to the output shaft 44. The protruding height of the protruding portion 31 c is set to be slightly lower than the protruding height of the gear teeth 51 a of the output gear 51, and both ends of the protruding portion 31 c along the circumferential direction of the output gear 51 are provided as contact surfaces. The third contact surface 31d and the fourth contact surface 31e are formed.

Next, the operation of the wiper motor 10 formed as described above will be described in detail with reference to the drawings.
[Normal operation status]
When a wiper switch (not shown) is operated to drive the wiper motor 10 to rotate, the wiper member (output shaft 44) is driven to swing in the direction of the arrow SW as shown in FIG. A reciprocating wiping operation is performed between the (stop position) and the second reverse position which is the other side reverse position. Thereby, rainwater, dust, etc. adhering to the rear glass can be wiped off. At this time, in a state where a large load is not applied to the output shaft 44 (normal operation state), the swing angle of the output shaft 44 is α ° (for example, 160 °).

When the wiper motor 10 is in a normal operation state and the wiper member is in the first reverse position (stop position), as shown in FIG. 3A, the first contact surface 51b of the gear tooth 51a and the protrusion 31c. A predetermined gap S1 is formed between the third contact surface 31d and the contact surfaces 51b and 31d do not contact each other. Further, when the wiper motor 10 is in a normal operation state and the wiper member is in the second reverse position, as shown in FIG. 3B, the second contact surface 51c of the gear tooth 51a and the first portion of the protrusion 31c. A predetermined gap S2 is formed between the four contact surfaces 31e and the contact surfaces 51c and 31e do not contact each other.
[Loading state]
As shown in FIG. 4, when the wiper member is in the first reverse position (stop position), for example, the snow S that has fallen on the roof of the vehicle slides down on the rear glass, and a large load F1 due to the snow S is applied to the wiper member. When applied, a large load is also applied to the output shaft 44. Then, the output shaft 44 rotates in the arrow R1 direction (positive direction) beyond the swing angle α ° by the load F1 applied to the wiper member. Then, the first contact surface 51b of the gear tooth 51a approaches the third contact surface 31d of the protrusion 31c, and the contact surfaces 51b and 31d come into contact with each other as shown by an arrow CP1. . As a result, the rotation of the output shaft 44 (wiper member) by a predetermined angle or more is restricted, and the driving of the gear mechanism 40 by the load F1 is stopped. Therefore, it is possible to protect the gear mechanism 40 from gear chipping or the like, that is, to protect the components forming the wiper motor 10.

  On the other hand, as shown in FIG. 5, when the wiper member is in the second reversal position, for example, the snow S that has fallen on the roof of the vehicle slides down on the rear glass, and a large load F2 due to the snow S is applied to the wiper member. A large load is also applied to the output shaft 44. Then, the output shaft 44 exceeds the swing angle α ° by the load F2 applied to the wiper member and rotates in the arrow R2 direction (reverse direction). Then, the second contact surface 51c of the output gear 51 approaches the fourth contact surface 31e of the protrusion 31c, and the contact surfaces 51c and 31e come into contact with each other as shown by the arrow CP2. . As a result, the rotation of the output shaft 44 (wiper member) beyond a predetermined angle is restricted, and the driving of the gear mechanism 40 by the load F2 is stopped. Therefore, it is possible to protect the gear mechanism 40 from gear chipping or the like, that is, to protect the components forming the wiper motor 10.

  As described above in detail, according to the wiper motor 10 according to the present embodiment, the gear teeth 51 a are provided on the outer peripheral side of the output gear 51 along the circumferential direction of the output gear 51 over a substantially half circumference, and output to the gear case 31. Protruding portions 31c projecting in the radial direction of the gear 51 are provided, and contact surfaces 51b, 51c, 31d for restricting rotation of the output shaft 44 over a predetermined angle so as to be able to contact the gear teeth 51a and the protruding portions 31c. 31e was provided.

  As a result, when a large load is applied to the output shaft 44, the contact surfaces 51b, 51c of the gear teeth 51a and the contact surfaces 31d, 31e of the protrusion 31c contact each other, and the output shaft 44 has a predetermined angle. The rotation can be restricted as described above. At this time, since each contact surface 31d, 31e of the protrusion 31c receives a large load, the large load is not transmitted to other components (gear mechanism 40, etc.) housed in the gear case 31. Therefore, the components forming the wiper motor 10 can be protected. In addition, since a large load is not applied to the component parts, it is possible to reduce the weight of the wiper motor 10 by weakening the rigidity of the component parts. Furthermore, since it is only necessary to form the contact surfaces 51b, 51c, 31d, and 31e on the output gear 51 and the protrusion 31c, a simple and inexpensive structure can be achieved without increasing the number of parts, and the assembly process can be simplified. At the same time, the wiper motor 10 can be further downsized.

  Further, according to the wiper motor 10 according to the present embodiment, since the protrusion 31c is integrally formed with the gear case 31, troubles such as assembling the protrusion 31c to the gear case 31 can be saved. Therefore, the assembly process of the wiper motor 10 can be further simplified.

  Furthermore, according to the wiper motor 10 according to the present embodiment, the contact surfaces 51b and 51c are provided on both end sides of the gear teeth 51a along the circumferential direction of the output gear 51, so the first reverse position of the wiper member Even when a large load is applied to the output shaft 44 at both the (stop position) and the second reverse position, the components forming the wiper motor 10 can be protected.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the output gear 51 formed of a sintered material or the like and the motion conversion member 45 formed of a metal material such as a steel plate are shown. The gear 51 and the motion converting member 45 can also be formed of a resin material such as plastic.

  Moreover, in the said embodiment, although what employ | adopted the electric motor with a brush as the motor part 20 was shown, this invention is not restricted to this, For example, a brushless electric motor etc. can also be employ | adopted.

  Further, in the above embodiment, the wiper motor 10 is applied to the drive source of the rear wiper device of a vehicle such as an automobile. However, the present invention is not limited to this, and the windshield glass of the vehicle such as an automobile is wiped off. It can also be applied to a drive source of a front wiper device.

  In the above embodiment, the wiper motor 10 is used as a drive source for a wiper device mounted on a vehicle such as an automobile. However, the present invention is not limited to this, and is mounted on a railway vehicle, an aircraft, a ship, or the like. It can also be used as a drive source for the wiper device.

DESCRIPTION OF SYMBOLS 10 Wiper motor 20 Motor part 21 Motor case 22 Permanent magnet 23 Coil 24 Armature 25 Armature axis (rotary axis)
26 Commutator 27 Brush 28 Worm (Gear mechanism, Reduction mechanism)
30 Gear part 31 Gear case 31a Bottom part 31b Boss part 31c Projection part 31d Third contact surface (contact surface)
31e Fourth contact surface (contact surface)
32 Gear cover 32a Mounting leg 40 Gear mechanism 41 Reduction mechanism (gear mechanism)
42 Motion conversion mechanism (gear mechanism)
43 Worm wheel 43a Tooth part 43b Rotation center shaft 43c Connection shaft 44 Output shaft 44a Serration part 44b Male thread part 45 Motion conversion member 45a Connection part 45b Sector gear 46 Connection plate 47, 48, 49 Resin cap 50 Seal member 51 Output gear (gear mechanism) )
51a Gear teeth 51b First contact surface (contact surface)
51c 2nd contact surface (contact surface)
52 Gear shaft α Swing angle S Snow F1, F2 Load S1, S2 Predetermined clearance

Claims (2)

A wiper motor that converts the rotational motion of the rotary shaft into a swing motion by a gear mechanism, and swings and drives the wiper member attached to the output shaft between the one-side reverse position and the other-side reverse position,
A bottomed gear case in which an opening is formed and accommodates the gear mechanism;
A gear cover that closes the opening;
An output gear that forms the gear mechanism and is provided on the output shaft so as to be integrally rotatable;
Gear teeth provided on the outer peripheral side of the output gear and formed over a substantially half circumference along the circumferential direction of the output gear;
A motion conversion member that forms the gear mechanism and meshes with the gear teeth;
Holding the meshing between the output gear and the motion conversion member, and a connecting plate provided on the opening side;
A resin cap that is provided between the connecting plate and the gear cover and is in sliding contact with the inner surface of the gear cover;
A worm wheel that forms the gear mechanism and is rotatably connected to the motion conversion member;
A protrusion provided on the gear case and projecting in a radial direction of the output gear;
A contact surface that is provided so as to be able to contact the gear teeth and the protrusion, and restricts rotation of the output shaft by a predetermined angle or more;
Contact surfaces provided on the gear teeth are provided on both ends of the gear teeth along the circumferential direction of the output gear, and predetermined gaps are formed between the protrusions and the contact surfaces of the gear teeth. , When a load is applied to the output shaft, the contact surfaces and the protrusions are in contact with each other over the entire surface .
The meshing portion of the output gear and the motion conversion member and the contact surface of the protrusion are disposed opposite to each other around the output shaft,
The engagement portion of said output gear and said motion conversion member under a load to said output shaft, and wherein the Rukoto teeth are engaged at the end nearer along the circumferential direction of the output gear and said motion converting member Wiper motor.   2. The wiper motor according to claim 1, wherein the protrusion is formed integrally with the gear case.

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