JP4941428B2 - Rotating electric machine for vehicles - Google Patents

Description

  The present invention relates to a vehicular rotating electrical machine such as a vehicular AC generator or a generator motor mounted on a passenger car, a truck, or the like.

2. Description of the Related Art Conventionally, a rotating electrical machine in which a rotational position detector is fixed to an end of a rotating shaft is known (see, for example, Patent Document 1). The rotation position detection unit is fixed by providing four round holes in the annular plate, and passing through these round holes with fasteners such as screws to fasten them to the rotation shaft.
Japanese Patent Laid-Open No. 9-65620 (page 3-5, FIG. 1-3)

  By the way, in the attachment structure of the rotational position detection part disclosed by patent document 1, there exists dispersion | variation in an attachment position (an axial direction position and a circumferential direction position) on account of the tolerance of the round hole for attaching a fastener. There was a problem that the detection accuracy was lowered. In addition, fasteners such as screws are required, which increases the number of parts and the number of man-hours for attachment, which increases the cost and adjusts the position so that the rotational position detector can be attached to the target position. In the case of carrying out, further man-hours are required, and further cost increase is inevitable.

  The present invention was created in view of the above points, and an object of the present invention is to provide a vehicular rotating electrical machine capable of improving the detection accuracy of the rotational position and reducing the cost.

  In order to solve the above-described problems, a rotating electrical machine for a vehicle according to the present invention includes a rotor including a rotating shaft having a pair of slip rings electrically connected to a field winding, and a pair of sliding contacts with the slip rings. A brush device having a brush, a brush holder in which a housing portion for housing the pair of brushes is formed, and a cover member that covers the slip ring together with the brush holder; a rotational position detected portion disposed at one end of the rotation shaft; A rotation position detection unit that detects a rotation position of the position detection unit, and the rotation position detection unit includes a permanent magnet and a metal part to be detected that are integrally formed of resin, and one end of the rotation shaft is provided. It is fixed by press-fitting the detected part side metal part into the rotating shaft side metal part to be formed.

  By press-fitting the detected portion side metal portion into the rotating shaft side metal portion, the rotational position detected portion can be reliably fixed without adding parts such as screws. Moreover, since the axial position and the circumferential position of the rotational position detected part can be adjusted simultaneously when fixing by press-fitting, the rotational position detection accuracy can be improved, and an adjustment process is unnecessary. Therefore, the cost can be reduced. In addition, by integrally molding the permanent magnet and the metal part to be detected with resin, it is possible to reduce costs by reducing the number of parts compared to separately preparing and assembling, and reliably at high speed rotation The permanent magnet can be held to increase the durability holding force.

Moreover, the to-be-detected part side metal part mentioned above has a convex shape, and the rotating shaft side metal part has a concave shape fitted into the convex shape . Thereby, since the fitting part of a to-be-detected part side metal part and a rotating shaft side metal part can be set in a rotating shaft, the axial length at the time of fixing a rotation position detected part can be shortened.

  Moreover, it is desirable that the above-described detected-part-side metal part protrude beyond the end face of the permanent magnet. When the rotational position detected part is press-fitted into the rotating shaft, the end of the detected part side metal part can be pressed to fix the rotational position detected part, thereby reducing the stress applied to the permanent magnet and the resin. can do.

  In addition, it is desirable that the detected portion side metal portion and the rotating shaft side metal portion have the same linear expansion coefficient. As a result, it is possible to prevent stress concentration due to loosening or excessive tightening due to different degrees of expansion when the temperature rises.

  Moreover, it is desirable that the above-described detected portion side metal portion and the rotating shaft side metal portion are formed using a metal having a close ionization tendency. Thereby, generation | occurrence | production and progress of corrosion by the difference in ionization can be prevented.

  Moreover, it is desirable that a groove is formed in the metal part to be detected described above. Thereby, the load added to a rotating shaft at the time of press injection can be reduced.

  Hereinafter, an automotive alternator according to an embodiment to which a rotating electrical machine for a vehicle of the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of an automotive alternator according to an embodiment. 1 includes a front frame 1, a rear frame 2, a stator 3, a rotor 4, a control device 5, a brush device 6, a rotation position sensor 7, a rear cover 8, a pulley 9, and the like. It is configured to include.

  Both the front side frame 1 and the rear side frame 2 have a bowl shape, and are fixed to each other by a plurality of bolts in a state in which the openings 3 face each other and the stator 3 is sandwiched therebetween. A cylindrical bearing box 11 is formed integrally with the front frame 1, and an iron bearing box 21 is attached to the rear frame 2. The stator 3 includes a stator core 31 and a stator winding 32.

  The rotor 4 includes a field winding 41, pole cores 42 and 43, a rotating shaft 44, and the like, and is rotatably held by a pair of bearings 13 and 14 housed in bearing boxes 11 and 21. Cooling fans 45 and 46 are attached to the axial end surfaces of the pole cores 42 and 43. A pulley 9 is coupled to the front end of the rotating shaft 44 by a nut 10 and is rotated by a vehicle engine (not shown). Further, a pair of slip rings 47 and 48 connected to both ends of the field winding 41 are provided at the rear end of the rotating shaft 44 positioned outside the rear frame 2.

  The rotational position sensor 7 detects the rotational position of the rotor 4, is arranged at one end of the rotating shaft 44 and rotates with the rotor 4 as a disk-shaped detected part (rotational position detected part) 71, A detection unit (rotation position detection unit) 72 that detects the rotation position of the detected unit 71 is included.

  So-called electrical components such as the control device 5 and the brush device 6 are fixed to the outer axial end surface of the rear frame 2 by fixing means such as bolts. The control device 5 rectifies the three-phase AC voltage that is the output voltage of the stator winding 32 and converts it into a DC output voltage, and controls the direction and magnitude of the energization of the excitation current flowing in the field winding 41. By doing so, the output voltage of the vehicle alternator 100 is controlled. The brush device 6 is for passing an exciting current from the control device 5 to the field winding 41 of the rotor 4 and presses against each of the slip rings 47 and 48 formed on the rotating shaft 44 of the rotor 4. Brushes 61 and 62 are provided. These electrical components are covered with a rear cover 8.

  FIG. 2 is a view of the vehicle alternator 100 as viewed from the rear side, and shows a state in which the brush device 6 is exposed with the rear cover 8, the control device 5, and the rotational position sensor 7 removed. The stator winding 32 includes two sets of three-phase windings 32A and 32B, each phase coil X, Y, Z of one three-phase winding 32A and each phase coil U of the other three-phase winding 32B, Each end of V and W extends to the rear side through a through hole provided in the rear frame 2. These end portions are connected to the control device 5.

  Next, the detailed structure of the brush apparatus 6 and the to-be-detected part 71 is demonstrated. FIG. 3 is a cross-sectional view of the brush device 6 and the rotational position sensor 7. The brush device 6 includes a brush holder 200, brushes 61 and 62, and a cover member 250.

  The brush holder 200 has a box shape, and has a rectangular parallelepiped-shaped storage portions 211 and 212 that store two brushes 61 and 62 on the positive electrode side and negative electrode side, and flexible brushes 61 and 62, respectively. A pair of terminals 221 and 222 that are electrically connected to a pigtail 63 serving as a lead portion having a characteristic and project outside are provided. The terminals 221 and 222 are insert-molded in a brush holder 200 made of insulating resin.

  Further, the cover member 250 is disposed on the radially outer side with respect to the slip rings 47 and 48 and on one end (end portion on the slip ring 47 or 48 side) of the rotating shaft 44, and together with the brush holder 200, the slip ring 47, 48 is covered. Further, the cover member 250 has an opening portion 262 as an opening portion having a diameter smaller than the outermost diameter portion of the detected portion 71 at a position corresponding to one end of the rotation shaft 44.

  The brushes 61 and 62 are metal graphite containing copper powder in natural graphite and using a phenol resin or the like as a binder. For example, it is manufactured by the manufacturing process shown in FIG. That is, powder processing (step 100) for mixing raw material (natural graphite) and binder (phenol resin), mixing of copper powder (step 101), arrangement of pigtail 63 (step 102), molding (step 103), firing The brushes 61 and 62 are manufactured through each step (Step 104). The brushes 61 and 62 have the same shape, and the same shape is disposed with the pigtails 63 facing each other, and is housed in the housing portions 211 and 212 with the spring 64 interposed. The brushes 61 and 62 are pressed toward the slip rings 47 and 48 by the spring 64 and are in sliding contact within the storage portions 211 and 212.

  The detected portion 71 is press-fitted and fixed to one end of the rotating shaft 44 (the end portion on the slip rings 47 and 48 side). The detection unit 72 is fixed to a part of the control device 5 and is disposed to face the detected unit 71, and detects the position in the rotation direction of the region near the outer periphery of the disc-shaped detected unit 71. . Various methods can be considered as specific detection methods. For example, a magnetic body is arranged in the vicinity of the outer periphery of the detected part 71, and the rotational position of the magnetic body is detected by a detection coil provided in the detecting part 72, or a magnet is arranged in the vicinity of the outer periphery of the detected part 71, The case where the rotation position of this magnet is detected with the Hall element provided in the detection part 72 etc. can be considered. A method other than the above, for example, an optical detection method such as an optical sensor may be used.

  5 is a cross-sectional view taken along line VV in FIG. For example, as shown in FIGS. 3 and 5, in the detected part 71, a permanent magnet 71a and a detected part side metal part 71b are integrally formed of a resin 71c. The detected portion 71 is fixed by press-fitting the detected portion-side metal portion 71 b into the rotating shaft-side metal portion 44 a that forms one end of the rotating shaft 44. The permanent magnet 71a has NS magnetic poles magnetized in one direction along the surface. The detection unit 72 includes two Hall elements 72a and 72b arranged in the vicinity of the outer periphery of the permanent magnet 71a and spaced from each other by 90 °. Based on the outputs of these two Hall elements 72a and 72b, the rotational position of the permanent magnet 71a, that is, the rotational position of the rotor 4 to which the permanent magnet 71a is fixed via the resin 71c or the metal part 71b to be detected is detected. Is possible.

  In the present embodiment, the detected-part-side metal part 71b has a convex shape (specifically, a cylindrical shape) on the side of the rotation shaft 44, and the rotation-axis side metal part 44a is fitted into this convex shape. That is, it has a concave shape with an inner diameter slightly smaller than the outer diameter of the convex shape. Moreover, the to-be-detected part side metal part 71b protrudes slightly from the end surface of the permanent magnet 71a.

  Furthermore, the detected portion side metal portion 71b and the rotating shaft side metal portion 44a have the same linear expansion coefficient (preferably the same), and are subject to stress concentration due to loosening or excessive tightening due to different degrees of expansion when the temperature rises. It is preventing. Further, the detected portion side metal portion 71b and the rotating shaft side metal portion 44a are formed using a metal having a close ionization tendency (preferably, a metal having the same ionization tendency), and the occurrence and progress of corrosion due to the difference in ionization are observed. It is preventing.

  In addition, a groove is formed on the outer peripheral surface of the detected portion side metal portion 71b fitted to the rotating shaft side metal portion 44a. For example, when a groove (unevenness) is formed along the axial direction on the entire outer peripheral surface to form a knurl, a plurality of circular grooves perpendicular to the axial direction are formed, or one or a plurality of spiral grooves For example, the case of forming Thereby, since the outer peripheral surface (especially the top part between the grooves) of the detected-part-side metal part 71b is easily deformed during press-fitting, it is possible to reduce the load applied to the rotating shaft 44 during press-fitting.

  The detection unit 72 and the cover member 250 form a maze structure for preventing intrusion of water and other foreign matters from the top. On the other hand, since air has a smaller mass than water and other foreign substances, it reaches the vicinity of the detected portion 71 through the maze structure formed by the detecting portion 72 and the cover member 250, and passes through the opening portion 262. It is guided to the vicinity of the slip rings 47 and 48. Even if water or other foreign matter reaches the vicinity of the detected portion 71 through the maze structure, it is discharged in the ground direction through a gap between the detecting portions 72 provided in the ground direction.

  The detected portion 71 of the rotational position sensor 7 described above is attached and fixed to one end of the rotating shaft 44 after the brush device 6 is assembled, that is, with the periphery of the slip rings 47 and 48 covered with the cover member 250. . Thereby, attachment of the to-be-detected part 71 larger than the open part 262 becomes easy.

  In the present embodiment, the cover member 250 and the detection unit 72 form a maze structure in a direction along the radial direction of the rotation shaft 44. Specifically, as shown in FIG. 3, a labyrinth structure along the radial direction is formed by partially overlapping the axial positions of the cover member 250 and the detection unit 72. In the structure shown in FIG. 3, the axial position and the radial position of each of the detected portion 71 and the cover member 250 are partially overlapped to form a maze structure along the radial direction and the axial direction between them. Is formed. Thus, while introducing the cooling air through the gap between the cover member 250 and the detection unit 72 (not shown in FIG. 1, the rear cover 8 is provided with a through hole for introducing cooling air, and through this through hole. Cooling air is introduced from the outside to the inside of the rear cover 8 and a part thereof is guided to the gap between the cover member 250 and the detection unit 72), and water penetration is suppressed from the outside through this gap to ensure water resistance. be able to.

  As described above, in the vehicle alternator 100 according to the present embodiment, the detected portion-side metal portion 71b is press-fitted into the rotating shaft-side metal portion 44a, so that the detected portion 71 can be detected without adding screws or other components. Fixing can be performed reliably. Moreover, since the axial position and the circumferential position of the detected portion 71 can be adjusted simultaneously when fixing by press-fitting, the rotational position detection accuracy can be improved, and an adjustment process is unnecessary. Therefore, the cost can be reduced. Furthermore, by integrally molding the permanent magnet 71a and the detected part side metal part 71b with the resin 71c, it is possible to reduce the cost by reducing the number of parts compared to separately preparing and assembling, and at the time of high speed rotation However, the permanent magnet 71a can be reliably held and the durability holding force can be increased.

  Further, since the detected portion side metal portion 71b has a convex shape and the rotating shaft side metal portion 44a has a concave shape, the fitting portion between the detected portion side metal portion 71b and the rotating shaft side metal portion 44a. Can be set in the rotation shaft 44, and the axial length when the detected portion 71 is fixed can be shortened.

  Further, since the detected portion side metal portion 71b protrudes beyond the end face of the permanent magnet 71a, the end portion of the detected portion side metal portion 71b is pressed when the detected portion 71 is pressed into the rotating shaft 44. Thus, since the detected portion 71 can be fixed, the stress applied to the permanent magnet 71a and the resin 71c can be reduced.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the above-described embodiment, the detected-part-side metal part 71b is formed in a convex shape and the rotating shaft-side metal part 44a is formed in a concave shape, and these are fitted. .

  FIG. 6 is a diagram illustrating a modification of the detected portion. The detected portion 171 shown in FIG. 6 has the same basic structure as that of the detected portion 71 in which the permanent magnet 171a and the detected portion side metal portion 171b are integrally formed of the resin 171c, but the following points are different. . That is, in the structure shown in FIG. 6, the metal part 171b to be detected has a concave shape and is fitted to the convex rotating shaft metal part 144a formed by protruding the metal part of the rotating shaft 44. It is supposed to be. In the structure shown in FIG. 6, the metal part 171 b to be detected does not protrude toward the end face side of the permanent magnet 171 a, but a part of the metal part 171 b to be detected is formed in a convex shape like the part 71 to be detected. And you may make it protrude from the end surface of the permanent magnet 171a. Further, grooves such as knurls, circular grooves, and spiral grooves may be formed on the outer peripheral surface of the rotating shaft side metal portion 144a.

  In the above-described embodiment, the vehicular AC generator 100 that performs a power generation operation has been described. However, the present invention can also be applied to a generator motor that drives a rotor by generating a rotating magnetic field in the stator.

It is a figure showing the whole composition of the alternator for vehicles of one embodiment. It is the figure which looked at the alternating current generator for vehicles from the rear side. It is sectional drawing of a brush apparatus and a rotation position sensor. It is a figure which shows the manufacturing process of a brush. It is the VV sectional view taken on the line of FIG. It is a figure which shows the modification of a to-be-detected part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front side frame 2 Rear side frame 3 Stator 4 Rotor 5 Control apparatus 6 Brush device 7 Rotation position sensor 8 Rear cover 9 Pulley 44 Rotating shaft 44a, 144a Rotating shaft side metal part 47, 48 Slip ring 61, 62 Brush 63 Pigtail 64 Spring 71, 171 Detected part 71a, 171a Permanent magnet 71b, 171b Detected part side metal part 71c, 171c Resin 72 Detecting part 100 AC alternator for vehicle 200 Brush holder

Claims (5)

A brush holder in which a rotor including a rotating shaft having a pair of slip rings electrically connected to a field winding, a pair of brushes slidably contacting the slip rings, and a storage portion for storing the pair of brushes are formed And a brush device having a cover member that covers the slip ring together with the brush holder, a rotational position detected portion disposed at one end of the rotational shaft, and a rotational position detection that detects a rotational position of the rotational position detected portion A rotating electrical machine for a vehicle comprising:
In the rotational position detected part, the permanent magnet and the detected part side metal part are integrally formed of resin, and the detected part side metal part is press-fitted into the rotating shaft side metal part forming one end of the rotating shaft. It is fixed by,
The detected part side metal portion has a convex shape, the rotary electric machine for a vehicle wherein the rotation shaft side metal portion, characterized in Rukoto to have a concave shape fitted to the convex shape. In claim 1,
The rotating electrical machine for a vehicle according to claim 1, wherein the detected portion-side metal portion protrudes from an end face of the permanent magnet. In claim 1 or 2,
The rotating electrical machine for vehicles, wherein the detected portion side metal portion and the rotating shaft side metal portion have the same linear expansion coefficient. In any one of Claims 1-3,
The rotating electrical machine for a vehicle according to claim 1, wherein the detected portion side metal portion and the rotating shaft side metal portion are formed using a metal having a close ionization tendency. In any one of Claims 1-4,
A rotating electrical machine for a vehicle, wherein a groove is formed in the metal part to be detected.

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