JP2017070072A - Outer rotor type rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer rotor type rotary electric machine capable of reducing erroneous detection of a magnetic pole sensor in simple configuration.SOLUTION: An outer rotor type rotary electric machine 1 comprises: an outer rotor 10 which is coupled to a drive shaft 5 of an engine and configured by disposing a plurality of permanent magnets 13 in an inner peripheral part of a bottomed cylindrical yoke 11; a stator core 20 including a plurality of coils 23 configured by winding a winding wire 22 around teeth 21 of a core member; and a magnetic pole sensor 30 which detects a magnetic flux Wa between the permanent magnets 13 with a Hall element 32 and detects a rotation state of the outer rotor 10. In the magnetic pole sensor 30, the Hall element 32 is disposed in a clearance between neighboring teeth 21 of the stator core 20. The magnetic pole sensor 30 includes a case 33 for accommodating the Hall element 32 and a substrate 38 that supports the Hall element 32. Within the case 33, a magnetic substance 40 is provided for shielding a magnetic flux Wb that is generated between the coils 23.SELECTED DRAWING: Figure 13

Description

  The present invention relates to an outer rotor type rotating electric machine, and more particularly, to an outer rotor type rotating electric machine including a magnetic pole sensor that detects a rotation state of an outer rotor by a Hall element.

  2. Description of the Related Art Conventionally, an outer rotor type rotating electrical machine including a stator core formed by winding a coil around a plurality of radial teeth and a bottomed cylindrical outer rotor having a plurality of permanent magnets attached to an inner peripheral surface is known. ing. In such an outer rotor type rotating electrical machine, where to place a magnetic pole sensor for detecting the rotation state of the outer rotor has been studied as an element that affects the miniaturization of the rotating electrical machine and sensor performance. .

  In Patent Document 1, in an outer rotor type rotating electrical machine in which an outer rotor is fixed to a crankshaft that protrudes from a crankcase of a vehicle engine, a magnetic pole sensor unit is disposed in a space between a stator core and the crankcase. A long extension extending from the unit in the crankshaft direction is inserted into the gap between the teeth formed on the outer periphery of the stator core, and the outer rotor is rotated by a hall element incorporated in the extension. A configuration for detecting the state is disclosed.

JP 2009-240071 A

  The magnetic pole sensor disclosed in Patent Document 1 detects the magnetic flux from the north pole to the south pole of an adjacent permanent magnet by arranging the flat portion of the square plate-shaped hall element along the outer peripheral tangent of the stator core. Is configured to do. However, in the manufacturing process of the magnetic pole sensor, if the planar part of the Hall element is enclosed in the extension part in a state inclined with respect to a predetermined position, the magnetic flux from the N pole to the S pole of the adjacent coil is erroneously detected. As a result, the sensor output may be affected. For this reason, the subject that the high precision was calculated | required by the positioning process of a Hall element had arisen.

  An object of the present invention is to provide an outer rotor type rotating electrical machine that solves the problems of the prior art and can reduce erroneous detection of a magnetic pole sensor with a simple configuration.

  In order to achieve the above object, the present invention is provided with a plurality of permanent magnets (13) arranged on the inner peripheral portion of a bottomed cylindrical yoke (11) while being connected to an engine drive shaft (5). The permanent magnet includes a stator core (20) having a plurality of coils (23) formed by winding a winding (22) around a tooth (21) of a core member, and a hall element (32). (13) a magnetic pole sensor (30) for detecting a magnetic flux (Wa) between the magnetic poles (Wa) to detect a rotation state of the outer rotor (10), wherein the magnetic pole sensor (30) is configured such that the Hall element (32) is In the outer rotor type rotating electrical machine (1) disposed in a gap between adjacent teeth (21) of the stator core (20), the magnetic pole sensor (30) includes a sensor element (32) and the sensor element (32). Supporting group (38) and a magnetic body (40) that shields the magnetic flux (Wb) generated between the coils (23) is provided inside the case (33). There is a first feature.

  The sensor element (32) is a rectangular plate-like member, and the flat surface portion (32a) of the sensor element (32) is directed outward in the radial direction of the stator core (20), and the outer periphery of the stator core (20). The magnetic body (40) includes a bottom wall (42) positioned radially inward with respect to the substrate (38) and both circumferential ends of the bottom wall (42). Second side in that the sensor element (32) is disposed in a region surrounded by the bottom wall (42) and the side wall (41). There are features.

  The sensor element (32), the substrate (38), and the magnetic body (40) are housed in an extending portion (31) extending from the case (33) in the direction of the rotation axis of the outer rotor (10). There is a third feature.

  Moreover, the said side wall (41) has the 4th characteristic in the point extended to radial direction outer side rather than the plane part (32a) of the said sensor element (32).

  Furthermore, a fifth feature is that a positioning member (51) of the magnetic body (40) is provided inside the extending portion (31).

  According to the first feature, the magnetic pole sensor (30) includes a case (33) that houses a sensor element (32) and a substrate (38) that supports the sensor element (32). ) Is provided with a magnetic body (40) that shields the magnetic flux (Wb) generated between the coils (23), thereby preventing the magnetic flux generated between the coils from affecting the sensor element and False detection by the sensor can be prevented.

  Specifically, a plate-like sensor element such as a Hall element has a characteristic that it detects magnetic flux penetrating from the direction of the plane portion of the sensor element and does not detect magnetic flux input in parallel with the plane portion. Taking advantage of this characteristic, the rotation state of the outer rotor is detected by detecting the magnetic flux (magnetic pole) generated between the permanent magnets of the outer rotor, and the magnetic flux between the coils generated when the pulse is switched is substantially parallel to the plane portion. However, if the sensor element is tilted and fixed with respect to a predetermined position, it may detect magnetic flux that should not be detected and affect the sensor output. There is. Correspondingly, by providing a magnetic body in the case of the magnetic pole sensor, the magnetic flux between the coils is prevented from hitting the sensor element, so that erroneous detection can be prevented even if the sensor element is slightly tilted. It is also possible to avoid an increase in cost due to an increase in the positioning accuracy of the sensor element.

  According to the second feature, the sensor element (32) is a rectangular plate-like member, and the plane portion (32a) of the sensor element (32) is directed outward in the radial direction of the stator core (20), and The magnetic body (40) is disposed at a position along the outer periphery of the stator core (20). The magnetic body (40) includes a bottom wall (42) positioned radially inward with respect to the substrate (38), and the bottom wall ( 42) and a side wall (41) extending radially outward from both circumferential ends, and the sensor element (32) is disposed in a region surrounded by the bottom wall (42) and the side wall (41). Therefore, by enclosing the sensor element with a magnetic body having a substantially U-shaped cross section, even if a magnetic flux is generated between the coils, it is transmitted from the side wall → the bottom wall → the side wall, thereby preventing detection by the sensor element. be able to. Further, since the magnetic body is substantially U-shaped with the permanent magnet side opened, good sensor output can be obtained without affecting the detection of magnetic flux between the permanent magnets.

  According to the third feature, the sensor element (32), the substrate (38), and the magnetic body (40) are extended from the case (33) in the direction of the rotation axis of the outer rotor (10). Since it is housed in (31), it is possible to increase the detection accuracy of the magnetic pole sensor in the magnetic pole sensor having the extending portion for arranging the sensor element between the teeth of the stator core.

  According to the fourth feature, the side wall (41) extends radially outward from the flat portion (32a) of the sensor element (32), so that the magnetic flux between the coils is easily shielded by the side wall, It is possible to effectively prevent the magnetic flux between the coils from being detected by the sensor element.

  According to the fifth feature, since the positioning member (51) of the magnetic body (40) is provided inside the extension part (31), the extension part inserted between the teeth of the stator core is cut off. Although the area is small and the positioning of the sensor element is difficult, the use of a magnetic positioning member makes it easy to place the substrate and the sensor element in a predetermined position, thereby facilitating assembly.

It is a top view of the outer rotor type rotary electric machine which concerns on this embodiment. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a perspective view of the stator core which attached the magnetic pole sensor unit. It is a perspective view of a magnetic pole sensor unit. It is a bottom view of a magnetic pole sensor unit. It is a front view of the stator core which attached the magnetic pole sensor unit. It is a schematic diagram which shows the relationship between each Hall element and a permanent magnet. It is a partial cross section figure which shows the relationship between each Hall element and a stator core. It is a perspective view of a Hall element. It is a schematic diagram which shows the aspect of the magnetic flux at the time of a motor drive. It is a schematic diagram which shows the aspect of the magnetic flux at the time of pulse switching. FIG. 10 is a sectional view taken along line 10-10 in FIG. 8. It is a schematic diagram which shows the aspect of the magnetic flux at the time of applying the extension part which concerns on this embodiment. It is a schematic diagram which shows the modification of the structure of an extension part.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of an outer rotor type rotating electrical machine 1 according to the present embodiment. 2 is a cross-sectional view taken along line 2-2 of FIG. An outer rotor type rotating electrical machine (hereinafter also simply referred to as a rotating electrical machine) 1 is configured to be interlocked and connected to a drive shaft (crankshaft) 5 protruding from a crankcase 4 of an engine of a motorcycle. A so-called ACG starter motor that functions as a starter motor when the engine is started and functions as a generator after the engine is started.

  The rotating electrical machine 1 is configured as a brushless type rotating electrical machine including an outer rotor 10 that is interlocked and rotated with a drive shaft 5, and a stator core 20 that is housed inside the outer rotor 10 and fixed to the crankcase 4. Has been.

  The outer rotor 10 includes a yoke 11 formed into a bottomed cylindrical shape by appropriately forming a metal plate made of a ferromagnetic member, and a plurality of N poles fixed to the inner peripheral surface of the yoke 11 in the circumferential direction. And a plurality of pairs of permanent magnets 13 for each of the S poles. A boss portion 12 for connecting the yoke 11 and the drive shaft 5 is fixed to the central portion of the yoke 11.

  The stator core 20 is configured by laminating a plurality of plate-like core materials. Each core material is formed with a plurality of teeth 21 projecting radially from each other with a predetermined gap from the outer peripheral edge of the central annular portion provided with a through hole. A coil 23 is formed by winding a winding (coil winding) 22 by.

  The rotating electrical machine 1 functions as a starter that starts an engine by supplying power to each coil 23 based on a control signal from a control unit having a motor driver function. 5 and the outer rotor 10 in which the permanent magnets 13 are disposed rotate around the outer periphery of the stator core 20, thereby functioning as a generator that induces an electromotive force in the coil 23.

  In the present embodiment, a magnetic pole sensor unit (magnetic pole sensor) 30 that detects the rotation state of the outer rotor 10 is disposed between the stator core 20 and the crankcase 4. The magnetic pole sensor unit 30 is provided with a long extending portion 31 in which a Hall element 32 as a rectangular plate-shaped sensor element is enclosed. The magnetic pole sensor unit 30 is adjacent to each other by fixing the magnetic pole sensor unit 30 at a predetermined position. Each extending part 31 is configured to be inserted into a gap between the teeth 21. Thereby, the change in magnetic flux accompanying the rotation of the outer rotor 10 can be detected by the Hall element 32. The sensor harness 3 connected to the magnetic pole sensor unit 30 is routed along the input / output harness 2 of the rotating electrical machine 1 toward the control unit on the vehicle body side.

  FIG. 3 is a perspective view of the stator core 20 to which the magnetic pole sensor unit 30 is attached. 4 is a perspective view of the magnetic pole sensor unit 30, FIG. 5 is a bottom view of the magnetic pole sensor unit 30, and FIG. 6 is a front view of the stator core 20 to which the magnetic pole sensor unit 30 is attached. In the direction indicated by the arrows in the figure, the surface side where the magnetic pole sensor unit 30 is attached to the stator core 20 is “up”, the radially outer side of the stator core 20 is “out”, and the radially inner side is “in”.

  The case 33 of the magnetic pole sensor unit 30 is formed with a substantially fan-shaped storage recess 34 into which a resin mold material is injected after storing an electronic substrate or the like. A mounting boss 35 in which a through hole 37 for fixing the case 33 to the crankcase 4 is formed is formed on the radially outer side of the housing recess 34, and the case 33 is attached to the stator core 20 on the radially inner side of the housing recess 34. A through-hole 36 is formed for fixing to.

  The case 33 is an integrally molded part of synthetic resin, and is formed in an arc shape so as to face five coil portions adjacent in the circumferential direction. The four extending portions 31 extending in the rotation axis direction are each formed into a shape that can be fitted into a gap formed at the outer diameter edge between the coils 23 adjacent in the circumferential direction. The extension 31 is a bottomed cylindrical member provided with a storage space for enclosing the Hall element 32 and a substrate for supporting the Hall element 32, and an upper opening 39 of the storage space is formed at the bottom of the storage recess 34. Has been.

  The magnetic pole sensor unit 30 uses the permanent magnet 13 on the inner peripheral surface of the outer rotor 10 as a detection target, and detects the change in magnetic flux of the permanent magnet 13 accompanying the rotation of the outer rotor 10 by using the Hall element 32. For this reason, in order to detect the rotation state of the rotary electric machine 1 which is a three-phase alternating current type, the three Hall elements 32 corresponding to the U, V, and W phases are necessary.

  On the other hand, the magnetic pole sensor unit 30 is provided with four extending portions 31. This is because three adjacent holes 3 correspond to the U, V, and W phases. This is because each of the elements 32 is built in, and the hall element 32 for judging the ignition timing is built in one extending portion 31 (a) located at the end.

  FIG. 7 is a schematic diagram showing the relationship between each Hall element 32 and the permanent magnet 13. FIG. 8 is a partial cross-sectional view showing the relationship between each Hall element 32 and the stator core 20. As described above, each of the four extending portions 31 of the magnetic pole sensor unit 30 incorporates the hall elements 32. Among these four Hall elements 32, the rotation state of the outer rotor 10 is detected by three adjacent Hall elements (first Hall element 32a, second Hall element 32b, and third Hall element 32c), and at the end. The hall element located (fourth hall element 32d) detects the ignition timing.

  The four extending portions 31 have the same shape, but only the fourth hall element 32d for ignition timing has a different vertical arrangement position. This is for detecting the two-stage magnetized portion 14 provided only at one place among the plurality of permanent magnets 13 arranged in the circumferential direction on the outer rotor 10. The two-stage magnetized portion 14 is formed by forming an N pole on the opening side (the upper side in the drawing) of the outer rotor 10 in the S pole permanent magnet 13, and by the fourth Hall element 32d having a different position in the height direction, It is detected that three N poles appear continuously at one place in the circumferential direction.

  In response to the input of the engine start signal, the control unit controls the coil 23 of the stator core 20 to rotate the outer rotor 10 based on the motor drive signals from the first to third hall elements 32a, 32b, 32c. Further, ignition control is performed based on the rotation state of the outer rotor 10 and the ignition timing signal from the fourth hall element 32d.

  FIG. 9 is a perspective view of the Hall element 32. FIG. 10 is a schematic diagram showing an aspect of the magnetic flux when the motor is driven, and FIG. 11 is a schematic diagram showing an aspect of the magnetic flux when the pulse is switched.

  The Hall element 32 is a rectangular plate-shaped electronic component, and has a property that it cannot detect a magnetic flux that passes substantially parallel to the plane portion 32a while detecting a magnetic flux input from the direction of the plane portion 32a. The magnetic pole sensor unit 30 according to the present embodiment is fixed so that the planar portion 32a of the Hall element 32 faces radially outward in order to detect the rotational state of the outer rotor 10 using this property. More specifically, the surface S parallel to the flat portion 32a of the Hall element 32 is fixed so as to be perpendicular to the straight line C extending radially outward from the center of the rotation axis.

  With this configuration, the rotational state of the outer rotor 10 can be detected by detecting the magnetic flux Wa from the S pole to the N pole of the permanent magnet 13 during motor driving or power generation. On the other hand, as shown in FIG. 11, when the energization pattern to the coil 23 is switched, that is, when the pulse is switched (immediately after the pulse is switched), the magnetic field generated by the permanent magnet 13 and the magnetic field generated by the coil 23 are different. Since they influence each other, the magnetic flux from the N pole of the permanent magnet 13 to the S pole of the permanent magnet 13 via the S pole coil 23 becomes weak. As a result, a magnetic flux Wb along the substantially circumferential direction is generated between the adjacent teeth 21. Normally, the magnetic flux Wb is input substantially parallel to the planar portion 32 a of the Hall element 32. Therefore, the sensor output is not affected.

  However, when the Hall element 32 is sealed in the internal space of the extending portion 31 that is in the shape of a rectangular cylinder, the flat portion 32a of the Hall element 32 may be slightly inclined due to an accuracy error (the Hall element indicated by a broken line in the drawing). 32).

  In the state where the Hall element 32 is tilted, there is no effect on the sensor output during motor driving or power generation, but the angle at which the magnetic flux Wb generated at the time of pulse switching is not parallel to the plane portion 32a of the Hall element 32, that is, the magnetic flux Wb. Is input from an angle at which the sensor can be detected, and this may affect the sensor output. In particular, as shown in FIG. 11, when a magnetic flux Wb input from the back surface side (inner direction in the figure) of the flat portion 32a is detected, a magnetic flux in the direction opposite to the original detection direction is detected, and the sensor output is output. The effect will increase.

  Since this problem does not occur if the Hall element 32 is fixed at an original angle, it can be dealt with by increasing the dimensional accuracy related to the mounting of the Hall element 32. However, such a problem causes an increase in production cost. .

  Therefore, in the magnetic pole sensor unit 30 according to the present invention, a magnetic material having a predetermined shape is enclosed in the extending portion 31 together with the Hall element 32, so that even if the Hall element 32 is slightly inclined, it is affected by the magnetic flux Wb. It is configured so that there is nothing.

  FIG. 12 is a cross-sectional view taken along line 10-10 in FIG. 8, and FIG. 13 is a schematic diagram showing an aspect of magnetic flux when the extending portion 31 according to this embodiment is applied. As shown in FIG. 12, a hall element 32 and a substrate 38 that supports the hall element 32 are disposed in the extension portion 31, and a resin mold material 50 is filled around the hall element 32. It is held in place.

  The magnetic pole sensor unit 30 according to the present invention is characterized in that it further includes a magnetic body 40 having a substantially U-shaped cross section formed so as to surround the substrate 38 and the Hall element 32. The magnetic body 40 made of metal or the like is positioned upright from the bottom wall 42 parallel to the radially inner surface of the substrate 38 and the left and right ends (both ends in the circumferential direction) of the bottom wall 42 and positioned to the left and right of the Hall element 32. The side wall 41 has a shape extending radially outward from the flat portion 32a of the Hall element 32 by a dimensional difference h. Further, since the magnetic body 40 is formed so as to surround the Hall element 32 and the substrate 38, the width dimension (circumferential dimension) t of the bottom wall 42 is larger than the width dimension of the Hall element 32 and the substrate 38.

  As shown in FIG. 13, by providing this magnetic body 40, even when the magnetic flux Wb is generated with the Hall element 32 tilted, the magnetic flux Wb is changed from the side wall 41 to the bottom wall 42 to the side wall of the magnetic body 40. 41 and guided to the adjacent coil 23, it is possible to prevent the Hall element 32 from detecting the magnetic flux Wb. That is, the magnetic body 40 is a shielding plate that shields the input of the magnetic flux Wb to the Hall element 32 by the magnetic flux Wb, and is also an induction plate that changes the path of the magnetic flux Wb so that the Hall element 32 is not affected. Since the magnetic body 40 has a substantially U-shaped cross-section with the radially outer side open, it does not affect the detection of the magnetic flux Wa when the motor is driven or during power generation.

  In the magnetic pole sensor unit 30 according to the present embodiment, by including the magnetic body 40, it is possible to eliminate the influence of the magnetic flux Wb without increasing the positioning accuracy of the Hall element 32. Thereby, an increase in production man-hours due to an increase in positioning accuracy can be avoided, and detection accuracy of the magnetic pole sensor unit 30 can be increased by adding simple parts.

  FIG. 14 is a schematic diagram showing a modification of the structure of the extending portion 31 according to the present embodiment. Also in the above-described embodiment, as compared with the configuration in which only the Hall element 32 and the substrate 38 are sealed, the Hall element 32 is easily positioned by sealing the magnetic body 40 having a shape surrounding them. However, in this modification, the positioning member 51 that contacts the outside of the magnetic body 40 is further provided to facilitate the positioning of the magnetic body 40, and the shielding effect by the magnetic body can be achieved without increasing the assembly accuracy of the magnetic pole sensor unit 30. It is possible to ensure that it is demonstrated. Furthermore, the use amount of the resin molding material 50 is also reduced by enclosing the positioning member 51 made of hard resin or the like.

  The structure and form of the outer rotor type rotating electrical machine, the material and shape of the outer rotor and stator core, the form of the magnetic pole sensor unit, the material and form of the case, the shape of the extension, the shape and form of the Hall element, etc. Various changes are possible without being limited to the form. The magnetic pole sensor of the outer rotor type rotating electrical machine according to the present invention is not limited to a motorcycle engine, and can be applied to an ACG starter used for various engines.

  DESCRIPTION OF SYMBOLS 1 ... Outer rotor type rotary electric machine (rotary electric machine), 4 ... Crankcase, 5 ... Drive shaft, 10 ... Outer rotor, 11 ... Yoke, 13 ... Permanent magnet (magnetic pole), 20 ... Stator core, 21 ... Teeth, 22 ... Winding Wire, 23 ... Coil, 30 ... Magnetic pole sensor unit (magnetic pole sensor), 31 ... Extension part, 32 ... Hall element (sensor element), 32a ... Planar part, 33 ... Case, 40 ... Magnetic body, 41 ... Side wall, 42 ... bottom wall, 50 ... resin molding material, 51 ... positioning member, Wa ... magnetic flux between permanent magnets, Wb ... magnetic flux between coils, h ... dimensional difference

Claims (5)

An outer rotor (10) connected to the drive shaft (5) of the engine and having a plurality of permanent magnets (13) disposed on the inner periphery of a bottomed cylindrical yoke (11);
A stator core (20) having a plurality of coils (23) formed by winding the winding (22) around the teeth (21) of the core member;
A magnetic pole sensor (30) that detects the rotational state of the outer rotor (10) by detecting the magnetic flux (Wa) between the permanent magnets (13) by a Hall element (32),
In the outer rotor type rotating electrical machine (1), the magnetic pole sensor (30) includes the Hall element (32) disposed in a gap between adjacent teeth (21) of the stator core (20).
The magnetic pole sensor (30) includes a case (33) that houses a sensor element (32) and a substrate (38) that supports the sensor element (32).
An outer rotor type rotating electrical machine, wherein a magnetic body (40) for shielding magnetic flux (Wb) generated between the coils (23) is provided inside the case (33). The sensor element (32) is a rectangular plate-like member, and the plane portion (32a) of the sensor element (32) is directed outward in the radial direction of the stator core (20) and along the outer periphery of the stator core (20). Are located at
The magnetic body (40) includes a bottom wall (42) positioned radially inward with respect to the substrate (38), and a side wall (41) extending radially outward from both circumferential ends of the bottom wall (42). And consist of
The outer rotor type rotating electrical machine according to claim 1, wherein the sensor element (32) is disposed in a region surrounded by the bottom wall (42) and the side wall (41).   The sensor element (32), the substrate (38), and the magnetic body (40) are accommodated in an extending portion (31) extending from the case (33) in the rotation axis direction of the outer rotor (10). The outer rotor type rotating electrical machine according to claim 1 or 2, characterized in that   The outer rotor type rotating electric machine according to claim 2, wherein the side wall (41) extends radially outward from the flat portion (32a) of the sensor element (32).   The outer rotor type rotating electrical machine according to claim 3, wherein a positioning member (51) of the magnetic body (40) is provided inside the extending portion (33).