Motor device

Abstract

To provide a motor device capable of suppressing degradation in rotation detection accuracy.SOLUTION: A wiper motor 10 comprises a brushless motor part 60, an output shaft SH2, a first sensor magnet 66, a first sensor 104, a second sensor magnet 34, a second sensor 106, a control board 102, and a shield plate 112. The output shaft SH2 rotates by receiving rotational force transmitted from a rotation shaft SH1. The shield plate 112 is positioned so as to intersect with a first virtual plane M1 in a case where a plane which includes a virtual line K1 that connects the outermost periphery of the first sensor magnet 66 and the outermost periphery of the second sensor magnet 34 and is the shortest in length is set as the first virtual plane M1. Furthermore, the shield plate 112 is located at least between the first sensor magnet 66 and the second sensor 106, and between the second sensor magnet 34 and the first sensor 104.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a motor device.

Background Art

[0002] The motor described in Patent Document 1 includes a sensor substrate, a Hall IC facing a first sensor magnet provided on a rotor, and an MR sensor facing a second sensor magnet provided on a helical gear. The Hall IC is mounted on the surface of the sensor substrate. The MR sensor is disposed on the back surface of the sensor substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the motor of Patent Document 1, a Hall IC is mounted on the surface of a single sensor substrate, and an MR sensor is disposed on the back surface of the sensor substrate. Therefore, the distance between the first sensor magnet and the second sensor magnet is closer than in a configuration where the Hall IC and the MR sensor are provided on separate substrates. When the distance between the first sensor magnet and the second sensor magnet is close, interference occurs between the magnetic flux acting on the Hall IC and the magnetic flux acting on the MR sensor. As a result, there is a risk that the rotational detection accuracy of the rotation axis detected by the Hall IC and the rotational detection accuracy of the output axis detected by the MR sensor will decrease. That is, there is a risk that the rotational detection accuracy of the motor device will decrease.

Means for Solving the Problems

[0005] A motor device according to one aspect of the present invention includes a motor unit having a rotating shaft, an output shaft provided parallel to the rotating shaft and rotating by receiving a rotational force transmitted from the rotating shaft, a first sensor magnet that rotates integrally with the rotating shaft, a first sensor that detects the magnetism of the first sensor magnet, a second sensor magnet that rotates integrally with the output shaft, a second sensor that detects the magnetism of the second sensor magnet, a control board to which the first sensor and the second sensor are attached, and a magnetic shield that is positioned to intersect with a first virtual plane, which is a plane including a virtual line having the shortest length among the lines connecting the outermost circumferences of the first sensor magnet and the second sensor magnet, and is located at least on one of the space between the first sensor magnet and the second sensor and the space between the second sensor magnet and the first sensor.

Advantages of the Invention

[0006] According to one aspect of the present invention, even when the first sensor magnet and the second sensor magnet are in positions close to each other, at least part of the magnetic flux from the first sensor magnet toward the second sensor and the magnetic flux from the second sensor magnet toward the first sensor are shielded by the magnetic shield. Therefore, interference between the magnetic flux from the second sensor magnet and the magnetic flux from the first sensor magnet toward the first sensor is suppressed, and interference between the magnetic flux from the first sensor magnet and the magnetic flux from the second sensor magnet toward the second sensor is suppressed. As a result, at least one of the error in detecting the rotation of the rotating shaft by the first sensor and the error in detecting the rotation of the output shaft by the second sensor can be reduced, so that a decrease in the rotation detection accuracy of the motor device can be suppressed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0008] Hereinafter, as examples of embodiments, the first and second embodiments and modified examples will be described with reference to the drawings. In all the drawings for explaining the embodiments, the same or substantially the same components and elements are denoted by the same reference numerals. Also, for the components and elements once described, repeated explanations will not be given in principle.

[0009] In FIGS. 1 to 11, some of the components may be shown enlarged, or some components may be omitted. In the following description, unless otherwise specified, terms such as "first" and "second" are used only to distinguish components from each other and do not represent a specific rank or order.

[0010] 〔First Embodiment〕 The motor device according to the first embodiment is a wiper motor 10 that serves as a drive source for a wiper device (not shown) mounted in front of a vehicle such as an automobile.

[0011] <Overview of Wiper Motor> The wiper motor 10 shown in FIG. 1 is mounted near a windshield (not shown) of the vehicle. The wiper motor 10 operates by operating a wiper switch (not shown) provided in the vehicle interior. A wiper member (not shown) swingably provided on the windshield performs a wiping operation while reciprocating by the operation of the wiper motor 10. The wiper motor 10 includes a gear unit 20, a motor main body unit 40, a control unit 100 (FIG. 2), and a shield plate 112 (FIG. 2). The gear unit 20 and the motor main body unit 40 are firmly fixed by a plurality of fixing screws S1.

[0012] <Gear Unit> As shown in FIG. 2, the gear unit 20 includes a gear housing 22, a helical gear 28, an output shaft SH2, and a second sensor magnet 34. The output shaft SH2 rotates by receiving the rotational force transmitted from a rotation shaft SH1 described later. The gear unit 20 functions as a speed reduction mechanism unit that reduces the rotation of the rotation shaft SH1 and transmits it to the output shaft SH2.

[0013] The gear housing 22 is formed in a stepped substantially dish shape by injection molding a molten aluminum material or the like. The gear housing 22 also has a gear housing portion 24, a base plate mounting portion 26, and a bearing member housing portion 37. The gear housing portion 24 rotatably houses the helical gear 28.

[0014] The gear housing 22 is provided with a cylindrical bearing portion 29 that rotatably supports the output shaft SH2. As a result, the output shaft SH2 is smoothly and rotatably supported by the gear housing 22 without play. The base plate mounting portion 26 is a flat portion to which a base plate 52 described later is mounted.

[0015] In the following description, the "axial direction" means the direction in which the central axis CA of the rotating shaft SH1 described later extends. Here, taking the axial direction as the Z direction, it is indicated by the arrow Z. The Z direction is along the vertical direction as an example. The tip side of the arrow Z corresponds to the upper side, and the base end side of the arrow Z corresponds to the lower side.

[0016] The direction in which the rotating shaft SH1 and the output shaft SH2 are aligned is taken as the Y direction and is indicated by the arrow Y. The Y direction is the left - right direction as an example. The tip side of the arrow Y corresponds to the left side, and the base end side of the arrow Y corresponds to the right side. The direction orthogonal to both the Y direction and the Z direction is taken as the X direction and is indicated by the arrow X. The X direction is the front - rear direction as an example. The tip side of the arrow X corresponds to the front side, and the base end side of the arrow X corresponds to the back side.

[0017] <<Output shaft>> The output shaft SH2 is formed in a substantially cylindrical shape having a central axis CB along the Z direction. Further, the output shaft SH2 is provided in the gear portion 20. Here, the rotating shaft SH1 and the output shaft SH2 are provided "parallel" to each other along the Z direction with a gap in the Y direction. Note that the "parallel" in this embodiment means the arrangement relationship of two shafts including a deviation due to an error within an allowable range, and does not mean only the arrangement relationship where the two shafts are completely parallel.

[0018] The lower end portion of the output shaft SH2 is fixed to a disk - shaped shaft fixing portion 32. The shaft fixing portion 32 is fixed to the upper central portion in the radial direction of the helical gear 28 by pins and screws (not shown). A second sensor magnet 34 described later is fixed to the lower central portion in the radial direction of the helical gear 28.

[0019] The bearing member housing portion 37 is formed in a cylindrical shape. Inside the bearing member housing portion 37, a bearing member 38 is accommodated. The bearing member 38 rotatably supports the upper end portion of the rotating shaft SH1. The bearing member 38 restricts the movement of the rotating shaft SH1 in the radial direction and the thrust direction. A backup portion 39 is provided on the bearing member 38.

[0020] The backup portion 39 is arranged with a minute gap from the outer peripheral surface of a pinion gear 63 described later. When a large external force is applied to the output shaft SH2 and the pinion gear 63 receives a pressing force from the helical gear 28, the backup portion 39 suppresses the bending of the rotating shaft SH1.

[0021] <<Second Sensor Magnet>> The second sensor magnet 34 shown in FIG. 4 is an example of a second magnet that rotates integrally with the output shaft SH2. The second sensor magnet 34 is formed in a disc shape having a predetermined thickness in the Z direction. The second sensor magnet 34 is used for detecting the rotational positions of the helical gear 28 (FIG. 2) and the output shaft SH2 (FIG. 2). Specifically, the second sensor magnet 34 has a disc-shaped base portion 35 having an outer peripheral surface 35A, and a protruding portion 36 protruding radially outward from the outer peripheral surface 35A of the base portion 35.

[0022] As shown in FIG. 9, since the lower end portion of the outer peripheral surface 35A of the second sensor magnet 34 is located most outward in the radial direction, it is included in the outermost periphery of the second sensor magnet 34. Here, a position at the lower end of the outer peripheral surface 35A and closest to the first sensor magnet 66 is defined as position B.

[0023] <Motor Main Body Portion> As shown in FIG. 2, the motor main body portion 40 includes a motor housing 42, a base plate 52, a first ball bearing B1, a second ball bearing B2, and a brushless motor portion 60.

[0024] The motor housing 42 is formed in a stepped, substantially dish-shaped form by injection molding a molten aluminum material or the like. The motor housing 42 has a motor housing portion 44 and a substrate mounting portion 48.

[0025] The motor housing portion 44 includes a bottom wall 45, a mounting wall 46, and a side wall 47. Inside the motor housing portion 44, a brushless motor portion 60 is accommodated. The mounting wall 46 is a cylindrical wall that stands upright upward in the Z direction from the central portion of the bottom wall 45. A first ball bearing B1 is attached to the mounting wall 46.

[0026] The side wall 47 stands upright upward in the Z direction from the outer edge portion of the bottom wall 45. A mounting flange 47A is provided at a part of the upper end portion of the side wall 47. The mounting flange 47A and the base plate mounting portion 26 sandwich the base plate 52 in the Z direction. The mounting flange 47A and the base plate 52 are fixed to the base plate mounting portion 26 by fixing screws S1.

[0027] The substrate mounting portion 48 is located on the right side in the Y direction with respect to the motor housing portion 44. Also, the substrate mounting portion 48 is located below the output shaft SH2, the helical gear 28, and the second sensor magnet 34. Inside the substrate mounting portion 48, a pedestal (not shown) for supporting a control substrate 102 described later is provided.

[0028] As shown in FIG. 3, the base plate 52 covers the motor housing portion 44 from above in the Z direction. Also, the base plate 52 is located above the stator core 72 described later in the Z direction. The base plate 52 is a member having a predetermined thickness in the Z direction. A circular through-hole 53 penetrating in the Z direction is formed in the base plate 52. The rotating shaft SH1 is inserted into the through-hole 53.

[0029] As shown in FIG. 2, a holding portion 54 is provided on the base plate 52. The holding portion 54 is formed in a cylindrical shape extending downward from the peripheral edge of the through hole 53. The holding portion 54 holds the second ball bearing B2. The rotating shaft SH1 is rotatably supported by the first ball bearing B1, the second ball bearing B2, and the bearing member 38.

[0030] <Brushless motor section> As shown in FIG. 4, the brushless motor section 60 includes a rotor unit 62, a stator unit 70, a terminal section 82, a terminal holder 86, and a rotating shaft SH1. The brushless motor section 60 is an example of a motor section.

[0031] As shown in FIG. 2, the rotor unit 62 includes a rotating shaft SH1, a rotor yoke 64, and a plurality of first sensor magnets 66.

[0032] <<Rotating shaft>> The rotating shaft SH1 is made of, for example, a round steel bar. The lower part of the rotating shaft SH1 in the Z direction is rotatably supported by the first ball bearing B1 and the second ball bearing B2. A pinion gear 63 is integrally provided on the upper part of the rotating shaft SH1 than the center in the Z direction. The pinion gear 63 is formed spirally on the rotating shaft SH1 by knurling or the like. The pinion gear 63 meshes with the helical gear 28. Thus, when the rotating shaft SH1 is rotated, the helical gear 28 is rotated, and the output shaft SH2 is rotated.

[0033] The rotor yoke 64 is formed in a substantially U-shaped cross section (substantially dish-shaped) by pressing a steel plate (magnetic material) or the like. Further, the rotor yoke 64 holds a plurality of first sensor magnets 66 and is fixed to the lower part of the rotating shaft SH1.

[0034] <<First sensor magnet>> The plurality of first sensor magnets 66 shown in FIG. 4 are each an example of a first magnet. In FIG. 4, the reference signs are omitted for some of the first sensor magnets 66. Each of the first sensor magnets 66 is formed in a substantially tile shape (substantially arc shape) when viewed from the Z direction. The plurality of first sensor magnets 66 are arranged at equal intervals in the circumferential direction of the rotor yoke 64. Further, the plurality of first sensor magnets 66 are fixed to the inner peripheral surface of the rotor yoke 64. That is, the plurality of first sensor magnets 66 rotate integrally with the rotation axis SH1. Inside the plurality of first sensor magnets 66 in the radial direction, a stator core 72, which will be described later, is inserted.

[0035] The stator unit 70 has, as an example, a stator core 72, an insulator N (FIG. 2), a terminal portion 82 (FIG. 3), and a conductor (not shown).

[0036] The stator core 72 has, as an example, a cylindrical portion 74 extending in the Z direction and a plurality of teeth T. In FIG. 4, the reference signs are omitted for some of the teeth T. A coil portion C, which is an example of a coil, is provided on each of the plurality of teeth T. The coil portion C is formed by winding a conductor (not shown) around the teeth T. When current flows through the coil portion C, a magnetic field acting on the first sensor magnet 66 is generated.

[0037] The insulator N shown in FIG. 2 is made of an insulator such as plastic and covers the upper end portion and the lower end portion of the cylindrical portion 74 (FIG. 4).

[0038] As shown in FIG. 9, the outer peripheral surface 66A of the first sensor magnet 66 is located at the outermost periphery of the first sensor magnet 66. Let the position at the upper end of the outer peripheral surface 66A and closest to the second sensor magnet 34 be position A.

[0039] <<Terminal portion>> The terminal portion 82 shown in FIG. 4 is provided at the upper edge portion of the insulator N (FIG. 2). The terminal portion 82 electrically connects the brushless motor portion 60 and a control board 102 described later. The current supplied at a predetermined timing according to a command from a control portion 100 described later is supplied to a plurality of coil portions C via the terminal portion 82. In this way, the terminal portion 82 is electrically connected to the coil portion C via wiring (not shown).

[0040] Specifically, the terminal portion 82 includes a male terminal portion 83 on the insulator N side and a female terminal portion 84 (FIG. 3) on the terminal holder 86 side described later. The male terminal portion 83 has male terminals T1, T2, and T3 that stand upright along the Z direction in a part of the circumferential direction of the insulator N.

[0041] As shown in FIG. 3, the female terminal portion 84 has female terminals T4, T5, and T6 fixed to the terminal holder 86.

[0042] In the terminal portion 82 shown in FIG. 4, the male terminal T1 and the female terminal T4 (FIG. 3) are connected, the male terminal T2 and the female terminal T5 (FIG. 3) are connected, and the male terminal T3 and the female terminal T6 (FIG. 3) are connected. As an example of three phases (U phase, V phase, W phase) in the brushless motor portion 60, the male terminal T1 and the female terminal T4 correspond to the U phase, the male terminal T2 and the female terminal T5 correspond to the V phase, and the male terminal T3 and the female terminal T6 correspond to the W phase.

[0043] <<Terminal Holder>> The terminal holder 86 shown in FIG. 6 is an example of a holder and houses the female terminal portion 84 (terminal portion 82). Further, the terminal holder 86 supports a shield plate 112 (FIG. 2). The terminal holder 86 has a base portion 88, a notch portion 89, a housing portion 92, a hook portion 94, and a support portion 96.

[0044] The base 88 is formed in a plate shape having a predetermined thickness in the Z direction. Also, the base 88 is formed in a U shape that opens to the right when viewed from the Z direction. In other words, the base 88 has guide portions 88A and 88B that are spaced apart in the X direction. The guide portions 88A and 88B each have a depression formed in the upper part, which houses and supports wiring (not shown). The notch 89 is a part where the central portion of the base 88 in the X direction is cut out in an arc shape. The wiring housed in the guide portion 88A is connected to an external power source (not shown) as an example. The wiring housed in the guide portion 88B is connected to the control board 102 (FIG. 5) via three connection terminals 105 (FIG. 5) to be described later as an example.

[0045] The housing portion 92 is provided integrally with the base 88 and to the left of the base 88. Also, the housing portion 92 extends downward from the base 88. The housing portion 92 is formed in a box shape that opens upward. Inside the housing portion 92, the female terminal portion 84 is housed. The female terminal portion 84 is exposed from the lower surface 92A of the housing portion 92 and can be connected (engaged) with the male terminal portion 83 (FIG. 4). The lower surface 92A is formed in a planar shape along the X-Y plane. A side surface 92B is formed at the lower right end of the housing portion 92 and below the base 88. The side surface 92B is formed in a planar shape along the X-Z plane.

[0046] The engaging portion 94 is composed of two snap fits 95. One snap fit 95 is provided at each of the right end portions of the guide portion 88A and the guide portion 88B. The snap fit 95 is composed of a vertical plate portion 95A that extends in the Z direction and a horizontal plate portion 95B that extends from the lower end of the vertical plate portion 95A to the left. The terminal holder 86 can be attached to the control board 102 (FIG. 5) by the elastic deformation of the vertical plate portion 95A in the X direction.

[0047] <<<Support portion>>> As shown in FIG. 6, the support portion 96 is provided on the terminal holder 86. The support portion 96 supports a shield plate 112 (FIG. 7) described later. The support portion 96 has one engaging portion 97 and two inclined portions 98. One engaging portion 97 is an example of a first support portion. The two inclined portions 98 are examples of second support portions. When viewed from the X direction, the engaging portion 97 and the inclined portion 98 are spaced apart in an intersecting direction (S direction (FIG. 7)) that intersects the thickness direction of the shield plate 112.

[0048] The engaging portion 97 has a column portion 97A that extends downward from the front end portion of the guide portion 88A, and a plate portion 97B that extends leftward from the lower end of the column portion 97A. The plate portion 97B has a bottom surface 97C. The bottom surface 97C is located on a virtual plane substantially the same as the lower surface 92A. The column portion 97A and the plate portion 97B have an L-shaped cross section when viewed from the X direction. Note that the engaging portion 97 is not provided on the guide portion 88B.

[0049] The two inclined portions 98 are provided on the side surface 92B at intervals in the X direction. As an example, the positions of the two inclined portions 98 in the X direction are deeper than the position of the engaging portion 97 in the X direction. Also, the two inclined portions 98 protrude rightward from the side surface 92B respectively. The two inclined portions 98 have the same configuration. For this reason, the front inclined portion 98 will be described, and the description of the rear inclined portion 98 will be omitted.

[0050] The inclined portion 98 is a portion having a substantially triangular cross section in the Y-Z plane. Specifically, the inclined portion 98 includes a bottom surface 98A, an inclined surface 98B, and two side surfaces 98C.

[0051] The bottom surface 98A is located on the same plane as the lower surface 92A. That is, the lower surface 92A, the bottom surface 97C, and the bottom surface 98A are located on the same plane. And the lower surface 92A, the bottom surface 97C, and the bottom surface 98A are in contact with a front-side mounting surface 103A (FIG. 5) described later. In other words, the engaging portion 97 and the inclined portion 98 are supported by the control board 102.

[0052] The inclined surface 98B extends obliquely downward from the upper part of the side surface 92B toward the right end of the bottom surface 98A. In other words, the inclined surface 98B is an example of an inclined surface that is inclined so that the distance from the engaging portion 97 in the thickness direction of the shield plate 112 is different.

[0053] As shown in FIG. 8, the engaging portion 97 supports one end portion in the S direction (FIG. 7) of the shield plate 112 by hooking the one end portion. The inclined surface 98B of the inclined portion 98 supports the other end portion in the S direction of the shield plate 112 by contacting (resting on) the other end portion.

[0054] <Control unit> As shown in FIG. 2, the control unit 100 includes a control board 102, a first sensor 104, a second sensor 106, and a CPU (Central Processing Unit) 108 (FIG. 3). A terminal holder 86 and a shield plate 112 are provided in the control unit 100.

[0055] <<Control board>> As shown in FIG. 5, the control board 102 has a predetermined thickness in the Z direction. The control board 102 is formed in a rectangular shape with the long side along the X direction and the short side along the Y direction. Here, the Y direction is the width direction of the control board 102. The control board 102 is fixed to the board mounting portion 48 (FIG. 2). The control board 102 has a mounting surface 103 on which each electronic component is mounted. The mounting surface 103 includes a front mounting surface 103A located on the upper side in the Z direction and a back mounting surface 103B located on the lower side in the Z direction. The front mounting surface 103A and the back mounting surface 103B are each a plane along the X - Y plane.

[0056] As an example, three connection terminals 105, the second sensor 106, the CPU 108, etc. are attached to the front mounting surface 103A. The first sensor 104, etc. are attached to the back mounting surface 103B.

[0057] <<First sensor>> The first sensor 104 consists of Hall sensors H1, H2, and H3, for example. The Hall sensors H1, H2, and H3 correspond to the U-phase, V-phase, and W-phase of the brushless motor unit 60 (Fig. 2), for example, and detect the magnetism (strength of the vertical magnetic field) of a plurality of first sensor magnets 66 (Fig. 2). The detection signal detected by the first sensor 104 is transmitted to the CPU 108.

[0058] <<Second Sensor>> The second sensor 106 is, for example, an MR (Magneto Resistive) sensor. The detection surface 106A of the second sensor 106 is formed in a planar shape along the X-Y plane, for example. The second sensor 106 detects the rotation position of the output shaft SH2 (Fig. 2) and the helical gear 28 (Fig. 2) by detecting the magnetism (angle of the horizontal magnetic field) of the second sensor magnet 34 (Fig. 2). The detection signal detected by the second sensor 106 is transmitted to the CPU 108.

[0059] < <cpu>> The CPU 108 determines the operation processing of each part of the wiper motor 10 (Fig. 1). Based on the detection signal transmitted from the first sensor 104, the CPU 108 determines the rotation state (such as rotation speed and rotation direction) of the rotating shaft SH1 (Fig. 2), and controls the rotation of the brushless motor unit 60 (Fig. 2) as necessary. Further, based on the detection signal transmitted from the second sensor 106, the CPU 108 determines the rotation position of the output shaft SH2 (Fig. 2), and similarly controls the rotation of the brushless motor unit 60.

[0060] <Shield plate> The shield plate 112 shown in Fig. 7 is an example of a magnetic shield and is made of an iron plate. The thickness direction of the shield plate 112 is defined as the D direction and is indicated by the arrow D. Also, the direction orthogonal to both the D direction and the Y direction is defined as the S direction and is indicated by the arrow S. The S direction is an example of the width direction of the shield plate 112. Note that, among the S direction, the side with a lower Z-direction position is taken as one end side, and the side with a higher Z-direction position is taken as the other end side.

[0061] The shield plate 112 has a rectangular outer shape having a long side along the Y direction and a short side along the S direction when viewed from the D direction. In the shield plate 112, the center position in the Y direction and the center position in the S direction are taken as the center CS. A line passing through the center CS and along the S direction is defined as the virtual line E.

[0062] The shield plate 112 has a predetermined thickness t1 in the D direction. The thickness t1 is, as an example, smaller than the thickness t2 of the control board 102. Also, the shield plate 112 has enhanced rigidity against external forces acting in the D direction. The shield plate 112 is, as an example, located above the control board 102. The shield plate 112 has one end portion 113 located at one end side in the S direction and the other end portion 114 located at the other end side in the S direction.

[0063] A groove portion 115 is provided at one end portion 113. The groove portion 115 is located on the front side in the Y direction with respect to the virtual line E. The groove portion 115 is notched in a rectangular shape having a long side along the Y direction and a short side along the S direction. The length of the short side of the groove portion 115 is shorter than the length in the Y direction of the column portion 97A (FIG. 6). The length of the long side of the groove portion 115 is slightly longer than the length in the X direction of the column portion 97A. That is, the groove portion 115 can be engaged with the engaging portion 97 (FIG. 6).

[0064] Groove portions 116 and 117 are provided at the other end portion 114. The groove portion 116 is located approximately at the center in the Y direction (on the virtual line E) of the other end portion 114. The groove portion 117 is located on the back side in the Y direction with respect to the virtual line E. The groove portion 116 and the groove portion 117 have the same configuration except for the arrangement. For this reason, the groove portion 116 will be described, and the description of the groove portion 117 will be omitted.

[0065] The groove portion 116 is notched in a rectangular shape having a long side along the Y direction and a short side along the S direction. The length of the short side of the groove portion 116 is set to be able to contact the inclined portion 98 (FIG. 6). The length of the long side of the groove portion 116 is slightly longer than the length in the X direction of the inclined portion 98. That is, the groove portions 116 and 117 can be engaged with the two inclined portions 98. In other words, the inclined portion 98 is located so as to be able to contact the other end portion 114 in the S direction of the shield plate 112.

[0066] The shield plate 112 is attached to the terminal holder 86 (FIG. 6) when the groove portion 115 is engaged with the engaging portion 97 (FIG. 6) and the groove portions 116 and 117 are brought into contact with the upper portions of the two inclined portions 98 (FIG. 6). In other words, the shield plate 112 is positioned and supported by the terminal holder 86. Note that the angle formed by the front mounting surface 103A and the shield plate 112 is defined as the angle θB.

[0067] As shown in FIG. 8, the terminal holder 86 is attached to the control board 102. Specifically, the male terminal portion 83 is connected to the female terminal portion 84, and the engaging portion 94 is hooked on the right end portion of the control board 102, whereby the terminal holder 86 is attached to the control board 102. The bottom surface 97C and the bottom surface 98A of the terminal holder 86 are in contact with the front mounting surface 103A. In other words, the engaging portion 97 and the inclined portion 98 are in contact with the mounting surface 103. Thereby, the terminal holder 86 is supported by the control board 102.

[0068] The shield plate 112 supported by the terminal holder 86 is positioned with respect to the control board 102. Specifically, the shield plate 112 is located between the terminal holder 86 and the control board 102.

[0069] As shown in FIG. 9, when viewed from the X direction, a virtual line K1 is defined as the line having the shortest length among the lines connecting the outermost circumference (position A) of the first sensor magnet 66 and the outermost circumference (position B) of the second sensor magnet 34. In other words, the line segment AB represents the shortest distance. Further, a first virtual plane M1 is defined as the plane including the virtual line K1. In FIG. 9, the illustration of the terminal holder 86 (FIG. 6) is omitted.

[0070] Also, a second virtual plane M2 is defined as the plane along the mounting surface 103 between the first sensor magnet 66 and the second sensor magnet 34. As an example, the second virtual plane M2 includes the detection surface 106A of the second sensor 106. Further, a third virtual plane M3 is defined as the plane including the line where the first virtual plane M1 and the second virtual plane M2 intersect and being orthogonal to the first virtual plane M1. In other words, the second virtual plane M2 and the third virtual plane M3 intersect.

[0071] In the Y-Z plane, an angle (acute angle) formed by the second virtual plane M2 and the third virtual plane M3 is defined as an angle θA. The angle θA is larger than the angle θB. A virtual space VA is defined as the space between the second virtual plane M2 and the third virtual plane M3. In the present embodiment, it is assumed that the virtual space VA includes the second virtual plane M2 and the third virtual plane M3.

[0072] Here, the shield plate 112 is positioned to intersect the first virtual plane M1. Also, the shield plate 112 intersects the second virtual plane M2 and is inclined at an angle θB with respect to the X-Y plane. Further, at least a part of the shield plate 112 is positioned between the first sensor 104 and the second sensor magnet 34. At least a part of the shield plate 112 is positioned within the virtual space VA.

[0073] 〔Operation of the First Embodiment〕 In FIG. 10, the magnetic flux lines MB existing between the first sensor magnet 66 and the second sensor magnet 34 are indicated by dotted lines. Also, the magnetic flux line MC with the shortest distance among the magnetic flux lines MB is indicated by a solid line. Further, a virtual shield plate SP orthogonal to the magnetic flux line MC is indicated by a two-dot chain line.

[0074] In the wiper motor 10, the shield plate 112 shields the magnetic flux lines MB and MC. In particular, between the first sensor 104 and the second sensor magnet 34, the shield plate 112 shields the magnetic flux lines MB and MC on the second sensor magnet 34 side. Thereby, it is possible to suppress an error in the detection of magnetism (the magnetic flux lines MB and MC on the first sensor magnet 66 side) by the first sensor 104. That is, in the wiper motor 10, it is possible to suppress a decrease in the rotation detection accuracy of the rotation shaft SH1 (FIG. 2) due to the influence of the magnetic flux line MB near the second sensor magnet 34.

[0075] Also, in the wiper motor 10, since magnetic interference can be suppressed by the shield plate 112, the first sensor magnet 66 and the second sensor magnet 34 can be arranged closer to each other, so that the wiper motor 10 can be miniaturized in the X direction, Y direction, and Z direction.

[0076] As shown in FIG. 9, in the wiper motor 10, the shield plate 112 is disposed in an inclined state with respect to the control board 102. Specifically, at least a part of the shield plate 112 is located within the virtual space VA from the second virtual plane M2 to the third virtual plane M3. In other words, the shield plate 112 is disposed in a state close to the shield plate SP (FIG. 10) where the shielding effect is the highest and the required minimum area is sufficient. Thereby, while reducing the area of the shield plate 112, an increase in the size of the wiper motor 10 in the axial direction (Z direction) can be suppressed.

[0077] In the wiper motor 10, the shield plate 112 is inclined so as to intersect the second virtual plane M2. Thereby, compared with the configuration in which the shield plate 112 is positioned along the second virtual plane M2, the shield plate 112 is disposed in a state closer to the shield plate SP (FIG. 10), so that the shielding effect by the shield plate 112 can be enhanced.

[0078] In the wiper motor 10, in order to control the rotation of the output shaft SH2 on the output side, it is important to control the rotation of the rotation shaft SH1 on the input side. Here, in the wiper motor 10, at least a part of the shield plate 112 is located between the first sensor 104 and the second sensor magnet 34. Thereby, an error due to magnetic interference that affects the detection of the rotation of the rotation shaft SH1 can be reduced, so that as a result of enhancing the rotation accuracy of the rotation shaft SH1, the rotation accuracy of the output shaft SH2 can be enhanced.

[0079] As shown in FIG. 8, in the wiper motor 10, a support portion 96 is provided on the terminal holder 86. The support portion 96 supports the shield plate 112. And the shield plate 112 is located between the terminal holder 86 and the control board 102. Thereby, since the shield plate 112 can be disposed by utilizing the dead space VD between the control board 102 and the terminal holder 86, an increase in the size of the wiper motor 10 in the Z direction can be suppressed as compared with a configuration having no support portion 96. Further, since it is not necessary to provide a member different from the terminal holder 86 for supporting the shield plate 112, an increase in the number of parts can be suppressed.

[0080] In the wiper motor 10, with one end portion of the shield plate 112 in the S direction supported by the engaging portion 97, the other end portion of the shield plate 112 in the S direction contacts the inclined portion 98. Therefore, even when there is a large variation in the size of the shield plate 112 in the S direction, the other end portion of the shield plate 112 in the S direction contacts and is supported by the inclined portion 98 by shifting downward due to its own weight in the Z direction. As a result, even when there are some errors in the dimensions of the shield plate 112, the errors are absorbed, making it easier to support the shield plate 112.

[0081] In the wiper motor 10, groove portions 115, 116, 117 (FIG. 7) are provided in the shield plate 112. The groove portion 115 engages with the engaging portion 97, and the groove portions 116 and 117 engage with the inclined portion 98. Thereby, the movement of the shield plate 112 in the X direction is restricted, so that it is possible to suppress the shield plate 112 from being displaced in the X direction after assembly.

[0082] In the wiper motor 10, the bottom surface 97C of the engaging portion 97 and the bottom surface 98A of the inclined portion 98 are in contact with the front mounting surface 103A of the control board 102. As a result, the engaging portion 97 and the inclined portion 98 are supported by the control board 102, making it difficult for them to be displaced in the Z direction. Consequently, it is possible to suppress the displacement of the shield plate 112 in the Z direction.

[0083] Note that in the wiper motor 10, since the engaging portion 97 and the inclined portion 98 are spaced apart in the Y direction, it is easy to insert the shield plate 112 along the X direction. After the shield plate 112 is inserted in the X direction, the shield plate 112 drops due to its own weight and is supported by the support portion 96. Therefore, it is easy to assemble the shield plate 112 to the terminal holder 86.

[0084] 〔Second Embodiment〕 The motor device according to the second embodiment is a wiper motor 120 (FIG. 11) that serves as a drive source for a wiper device (not shown) mounted in front of a vehicle such as an automobile.

[0085] The wiper motor 120 shown in FIG. 11 is different from the wiper motor 10 (FIG. 2) in that a second sensor 122 is provided instead of the second sensor 106 (FIG. 10), two shield plates 112 are provided, and a shield holder 124 is added. For components that are the same as or identical to those of the wiper motor 10, the same reference numerals as those of the wiper motor 10 are used and the description thereof is omitted. In addition, in FIG. 11, the terminal holder 86 (FIG. 8) is not shown.

[0086] <<Second Sensor>> The second sensor 122 is mounted on the front mounting surface 103A. The second sensor 122 is, for example, an MR sensor. The detection surface 122A of the second sensor 122 is formed in a planar shape along the X-Y plane, for example. The second sensor 122 detects the rotation position of the output shaft SH2 (FIG. 2) and the helical gear 28 (FIG. 2) by detecting the magnetism of the second sensor magnet 34. The detection signal detected by the second sensor 122 is transmitted to the CPU 108 (FIG. 3). Note that, for example, the second sensor 122 is larger in size in the X direction and the Y direction than the second sensor 106 (FIG. 10).

[0087] <<Shield Holder>> The shield holder 124 is an example of another holder that supports only the shield plate 112. A part of the shield holder 124 is fixed to the right side portion of the first sensor 104 on the back mounting surface 103B using screws (not shown). Specifically, the shield holder 124 includes a bottom plate portion 125, a vertical plate portion 126, an upper plate portion 128, and a support portion 132.

[0088] The bottom plate portion 125 is formed in a plate shape having a predetermined thickness in the Z direction. The vertical plate portion 126 stands upright upward from the left end portion of the bottom plate portion 125. The upper plate portion 128 extends to the right from the upper end portion of the vertical plate portion 126. The upper plate portion 128 is in contact with the back mounting surface 103B.

[0089] <<<Support Portion>>> The support part 132 has, as an example, one engaging part 134 and two inclined parts 98. The two inclined parts 98 are provided at intervals in the X direction on the right side surface 126A of the vertical plate part 126.

[0090] The engaging part 134 is a columnar part that stands upright upward from a part of the right end of the bottom plate part 125. The engaging part 134 engages with the groove part 115 (FIG. 7) of the shield plate 112.

[0091] <Shield plate> One shield plate 112 is supported by the terminal holder 86 (FIG. 8) above the control board 102. The other shield plate 112 is supported by the shield holder 124 below the control board 102. In the following description, the two shield plates 112 are distinguished as upper and lower. Here, among the magnetic flux lines MB, those existing on the side of the first sensor magnet 66 are defined as the first magnetic flux line MB1, and those existing on the side of the second sensor magnet 34 are defined as the second magnetic flux line MB2 and distinguished.

[0092] The lower shield plate 112 is positioned so as to shield a part of the first magnetic flux line MB1 when viewed from the X direction. Also, the lower shield plate 112 is inclined with respect to the X - Y plane such that the position of the left end is above the position of the right end. The groove parts 116 and 117 of the shield plate 112 engage with the upper parts of the two inclined parts 98.

[0093] 〔Operation of the Second Embodiment〕 In the wiper motor 120, the upper shield plate 112 shields the second magnetic flux line MB2 on the side of the second sensor magnet 34. Thereby, it is possible to suppress an error in magnetic detection by the first sensor 104. Further, the lower shield plate 112 shields the first magnetic flux line MB1 on the side of the first sensor magnet 66. Thereby, it is possible to suppress an error in magnetic detection by the second sensor 122. That is, in the wiper motor 120, in addition to improving the rotation detection accuracy of the rotation shaft SH1 (FIG. 2) by the first sensor 104, it is possible to improve the rotation detection accuracy of the output shaft SH2 (FIG. 2) by the second sensor 122.

[0094] 〔Modification Example〕 It goes without saying that the present invention is not limited to the above-described first and second embodiments, and may be implemented in various different forms within the scope of its technical idea. Hereinafter, modification examples will be described.

[0095] The wiper motor 10 is not limited to a configuration having a speed reduction mechanism portion, and may have a constant speed or speed increase mechanism portion.

[0096] In the wiper motor 10, the shielding plate 112 may be provided at the position of the shielding plate SP to enhance the effect (shielding effect) of suppressing the intrusion of magnetic flux lines. Further, as an example, a support portion such as a pin may be provided on the control board 102, and the shielding plate 112 may be directly attached to the control board 102 by supporting the shielding plate 112 by the pin. In other words, the support portion 96 may not be provided on the terminal holder 86.

[0097] In the wiper motor 10, the shielding plate 112 may be arranged along the second virtual plane M2. In other words, the shielding plate 112 may not be inclined so as to intersect the second virtual plane M2. Further, the shielding plate 112 may be arranged along the third virtual plane M3. When there is a margin in the space for providing the shielding plate 112, a part of the shielding plate 112 may be located above the third virtual plane M3.

[0098] The shielding plate 112 may be provided only between the second sensor 122 and the first sensor magnet 66. The shielding plate 112 may not be provided with groove portions 115, 116, and 117. For example, the shielding plate 112 may be adhered to the hooking portion 97 and the inclined portion 98. The shielding plate 112 is not limited to having a rectangular outer shape, and may have a square, circular, or elliptical outer shape.

[0099] Also, the number of a plurality of groove portions formed in the shield plate 112 may be different numbers or the same number at one end portion and the other end portion in the S direction. The number of groove portions is not limited to three of the groove portions 115, 116, and 117, and may be two or four or more. Further, the shape of the groove portion is not limited to a rectangular shape, and may be an arc shape. The groove portion formed in the shield plate 112 may engage with at least one of the engaging portion 97 and the inclined portion 98.

[0100] The shield plate 112 is not limited to being linear when viewed from the X direction, and may be curved. The curved state of the shield plate 112 may be either a curved state in which the central portion in the width direction is located on the side approaching the control substrate 102 or a curved state in which the central portion in the width direction is located on the side far from the control substrate 102. The material of the shield plate 112 is not limited to iron, and may be other metals or alloys having ferromagnetism. As another example of the magnetic shield, a magnetic sheet in which a magnetic material is laminated with a film or the like may be used.

[0101] The support portion 96 is not limited to a configuration in which both end portions of the shield plate 112 in the S direction are supported by the engaging portion 97 and the inclined portion 98. For example, the support portion 96 may have two engaging portions 97 facing the shield plate 112 in the S direction, and the two engaging portions 97 may support the shield plate 112. Either one of the engaging portion 97 and the inclined portion 98 may not be supported by the control substrate 102.

[0102] The terminal holder 86 may be located away from the front mounting surface 103A upward. In other words, the support portion 96 (the engaging portion 97 and the inclined portion 98) may not be in contact with the front mounting surface 103A.

[0103] In the wiper motor 120, even in a configuration having only the lower shield plate 112 without the upper shield plate 112, it is possible to suppress a decrease in the rotation detection accuracy of the output shaft SH2. Further, in the wiper motor 120, the lower shield plate 112 may be fixed by attaching it to the back mounting surface 103B without using the shield holder 124.

[0104] According to the wiper motors 10 and 120 of the first and second embodiments and the modified examples, a decrease in the rotation detection accuracy of at least one of the rotation shafts SH1 and SH2 is suppressed, so that variations in the output performance of each product as a motor device can be suppressed. And the production efficiency can be increased, and labor saving of manufacturing energy and suppression of generation of greenhouse gases can be achieved. Thereby, it becomes possible to achieve particularly Goal 7 (ensuring access for all people to affordable, reliable and sustainable modern energy) in the Sustainable Development Goals (SDGs) defined by the United Nations. Furthermore, it becomes possible to achieve Goal 13 (taking urgent measures to mitigate climate change and its impacts).

Explanation of Signs

[0105] 10: Wiper motor, 20: Gear part, 22: Gear housing, 24: Gear accommodating part, 26: Base plate mounting part, 28: Helical gear, 29: Bearing part, 32: Shaft fixing part, 34: Second sensor magnet, 35: Base part, 35A: Outer peripheral surface, 36: Protrusion part, 37: Bearing member accommodating part, 38: Bearing member, 39: Backup part, 40: Motor main body part, 42: Motor housing, 44: Motor accommodating part, 45: Bottom wall, 46: Mounting wall, 47: Side wall, 47A: Mounting flange, 48: Substrate mounting part, 52: Base plate, 53: Through hole, 54: Holding part, 60: Brushless motor part, 62: Rotor unit, 63: Pinion gear, 64: Rotor yoke, 66: First sensor magnet, 70: Stator unit, 72: Stator core, 74: Cylindrical part, 82: Terminal part, 83: Male terminal part, 84: Female terminal part, 86: Terminal holder, 88: Base part, 88A: Guide part, 88B: Guide part, 89: Notch part, 92: Accommodating part, 92A: Lower surface, 92B: Side surface, 94: Hanging part, 95: Snap fit, 95A: Vertical plate part, 95B: Horizontal plate part, 96: Support part, 97: Hanging part, 97A: Column part, 97B: Plate part, 97C: Bottom surface, 98: Tilt part, 98A: Bottom surface, 98B: Inclined surface, 98C: Side surface, 100: Control part, 102: Control substrate, 103: Mounting surface, 103A: Front side mounting surface, 103B: Back side mounting surface, 104: First sensor, 105: Connection terminal, 106: Second sensor, 106A: Detection surface, 108: CPU, 112: Shield plate, 113: One end part, 114: The other end part, 115: Groove part, 116: Groove part, 117: Groove part, 120: Wiper motor, 122: Second sensor, 122A: Detection surface, 124: Shield holder, 125: Bottom plate part, 126: Vertical plate part, 126A: Right side surface, 128: Upper plate part, 132: Support part, 134: Engagement part, A: Position, B: Position, B1: First ball bearing, B2: Second ball bearing, C: Coil part, CA: Central axis, CB: Central axis, CS: Center, D: Direction, E: Virtual line, H1: Hall sensor, H2: Hall sensor, H3: Hall sensor, K1: Virtual line, M: Direction, M1: First virtual surface, M2: Second virtual surface, M3: Third virtual surface, MB: Magnetic flux line, MB1: First magnetic flux line, MB2: Second magnetic flux line, MC: Magnetic flux line, MR: Hall, N: Insulator, S: Direction, S1: Fixing screw, SH1: Rotation axis, SH2: Output axis, SP: Shield plate, T: Teeth, t1: Thickness, t2: Thickness, T1: Male terminal,T2: Male terminal, T3: Male terminal, T4: Female terminal, T5: Female terminal, T6: Female terminal, VA: Virtual space, VD: Dead space, X: Direction, Y: Direction, Z: Direction, θA: Angle, θB: Angle,< / cpu>

Claims

1. A motor unit having a rotating shaft, An output shaft provided parallel to the rotating shaft and rotating by receiving the rotational force transmitted from the rotating shaft, A first sensor magnet that rotates integrally with the rotating shaft, A first sensor that detects the magnetism of the first sensor magnet, A second sensor magnet that rotates integrally with the output shaft, A second sensor that detects the magnetism of the second sensor magnet, A control board to which the first sensor and the second sensor are attached, When a plane including a virtual line having the shortest length among the lines connecting the outermost circumferences of the first sensor magnet and the second sensor magnet is defined as a first virtual plane, a magnetic shield that is positioned so as to intersect the first virtual plane and is located at least one of between the first sensor magnet and the second sensor and between the second sensor magnet and the first sensor, A motor device comprising the above.

2. When a plane along the mounting surface of the control board between the first sensor magnet and the second sensor magnet is defined as a second virtual plane, When a plane orthogonal to the first virtual plane is defined as a third virtual plane, The second virtual plane and the third virtual plane intersect, At least a part of the magnetic shield is located in a virtual space between the second virtual plane and the third virtual plane, The motor device according to claim 1.

3. The magnetic shield is inclined so as to intersect the second virtual plane, The motor device according to claim 2.

4. At least a part of the magnetic shield is located between the first sensor and the second sensor magnet, The motor device according to claim 3.

5. In the motor device according to any one of claims 1 to 4, Further comprising a holder that houses a terminal portion for electrically connecting the motor unit and the control board, The holder is provided with a support portion for supporting the magnetic shield, a motor device.

6. The magnetic shield is located between the holder and the control board, The motor device according to claim 5.

7. The magnetic shield is a shield plate having a predetermined thickness, The support portion has a first support portion and a second support portion that are spaced apart in an intersecting direction intersecting the thickness direction of the shield plate, The first support portion supports one end portion of the shield plate in the intersecting direction, The second support portion includes an inclined surface having a different distance from the first support portion in the thickness direction, The inclined surface supports the other end portion of the shield plate in the crossing direction. The motor device according to claim 6.

8. The shield plate is provided with a groove portion that engages with at least one of the first support portion and the second support portion. The motor device according to claim 7.

9. At least one of the first support portion and the second support portion is supported by the control substrate. The motor device according to claim 7.

Images