JP2004020494A - Rotary angle detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that a conventional rotary angle detector has a too long distance x' between a magnetic flux detecting area J7 and a magnet J2, because of providing a potting J6 protecting a fluctuation of magnetic flux detecting means J3 protecting from flying oil splash or metal powder. <P>SOLUTION: By adopting a constitution of rotary angle detector that a magnetic flux detecting means 52 is arranged on the other side of a board 53 facing to a magnet 51, a potting can be eliminated because the magnetic flux detecting means is protected by the board 53 from the flying oil splash or metal powder, therefore the distance x between a flux detecting area α and the magnet 51 can be shortened. By shortening the distance x, precision of detection can be improved, and also the magnetic flux intensity of the magnet 51 is not necessary so strong, therefore an inexpensive ferrite based plastic magnet can be used. Furthermore the cost can be reduced because the fluctuation of magnetic flux detecting means 52 etc., are protected by covering with an inexpensive protecting layer 55 protecting from the dew condensation or the oil instead of the expensive potting 16. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotation angle detection device that detects a rotation angle of a rotating electric machine (hereinafter, referred to as a rotating machine) such as an electric motor or a generator by using a change in magnetic force.
[0002]
[Prior art]
A conventional technique of this kind of rotation angle detecting device will be described with reference to FIG.
This rotation angle detecting device detects the rotation angle of the rotating body J1 in the case of the rotating machine, is arranged concentrically with the rotation axis of the rotating body J1, and has a multi-pole attachment in the rotating direction of the rotating body J1. The magnetized magnet J2, magnetic flux change detecting means J3 (Hall IC, Hall element, MRIC, etc.) for detecting the amount of change of the magnetic flux emitted from the magnet J2, and the magnetic flux change detecting means J3 receive the magnetic flux of the magnet J2. And a housing J5 that covers the substrate J4 from the opposite side of the magnet J2. The substrate J4 is fixed to the housing J5.
The conventional substrate J4 is made of, for example, an insulating epoxy resin containing glass, and the magnetic flux change detecting means J3 is mounted on the surface of the substrate J4 on the magnet J2 side.
[0003]
[Problems to be solved by the invention]
In the case of the rotating machine, oil such as rust-preventive oil adhered to the rotor, oil such as grease applied to the speed reducer, and wear powder (metal powder) of the speed reducer fly. For this reason, in order to protect the magnetic flux change detecting means J3 supported by the substrate J4 from flying oil and metal powder, the magnetic flux change detecting means J3 is potted with a potting agent such as silicon. A protective layer having a predetermined thickness y is formed on the surface by potting J6.
Therefore, the distance x 'between the magnetic flux detection area J7 in the magnetic flux change detection means J3 and the magnet J2 becomes long. Since the magnetic force emitted by the magnet J2 decreases in inverse proportion to the square of the distance, when the distance x 'increases, the magnetic flux reaching the magnetic flux detection area J7 weakens.
[0004]
[Object of the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to increase the distance between the magnetic flux detection area and the magnet in the magnetic flux change detection unit even in an environment where oil or metal powder flies. An object of the present invention is to provide a rotation angle detecting device that can be shortened.
[0005]
[Means for Solving the Problems]
[Means of claim 1]
In the rotation angle detecting device adopting the means of claim 1, the magnetic flux change detecting means is arranged on the opposite side of the magnet of the substrate, so that oil or metal powder flying from the magnet side is guarded by the substrate, and the magnetic flux change detecting means is provided. Is protected.
As a result, the distance between the magnetic flux detection area of the magnetic flux change detecting means and the magnet can be shortened, and the conventionally employed potting for protecting the magnetic flux change detecting means can be eliminated.
[0006]
[Means of Claim 2]
The means of claim 2 may be adopted, and the rotating body may be a rotor in a rotating machine such as an electric motor or a generator.
Thus, the rotation angle of the rotor can be detected with the distance between the magnetic flux detection area and the magnet shortened.
[0007]
[Means of Claim 3]
The means of claim 3 may be employed to join the magnet to the rotor core.
This makes it possible to reduce the thickness of the rotating machine equipped with the rotation angle detecting device.
[0008]
[Means of Claim 4]
A means for detecting magnetic flux change on the surface of the substrate from dew condensation or oil by applying a protection layer on the surface of the substrate on which the magnetic flux change detection means is mounted, the surface being opposite to the magnet. Can be protected.
[0009]
[Means of claim 5]
The means according to claim 5, wherein the substrate is composed of a non-magnetic metal plate and an insulating film substrate provided on the surface of the metal plate on the side opposite to the magnet. A circuit pattern may be provided on a surface that is not touched.
By using a metal plate for the substrate in this way, it is possible to prevent ripples on the substrate, and to prevent a change in the distance between the magnetic flux change detection means and the magnet due to the ripples on the substrate.
Further, by using a metal plate for the substrate, the substrate can be made thinner while maintaining the rigidity of the substrate, and the distance between the magnet and the magnetic flux change detecting means can be further reduced.
Further, since the circuit pattern is provided on the surface of the film substrate that does not touch the metal plate, there is no short circuit caused by the circuit pattern touching the metal plate.
[0010]
[Means of claim 6]
The means of claim 6 is adopted, and a terminal for connecting the substrate is provided on the housing facing the opposite side of the magnet of the substrate, and a part of the film substrate is provided so as to protrude from the metal plate. The film substrate may be provided so as to be turned 180 degrees and connected to the terminal terminal.
With this arrangement, the solder lands to be soldered to the terminal terminals can be formed on the film substrate on the same surface as the circuit pattern. In other words, since a single-sided substrate is sufficient, the cost of the substrate can be reduced.
[0011]
[Means of claim 7]
The means of claim 7 may be adopted, and the magnetic flux change detecting means and peripheral circuits may be modularized and arranged on the surface of the substrate opposite to the magnet.
With this arrangement, the magnetic flux change detecting means and peripheral circuits can be easily assembled.
[0012]
[Means of claim 8]
The means of claim 8 may be employed, and a non-magnetic film member may be provided between the magnet and the rotor core.
With such provision, the influence of the magnetic force applied to the magnet from the rotor core can be cut off, and erroneous detection of the rotation angle detection device can be prevented.
[0013]
[Means of claim 9]
The magnet may be directly joined to the rotor core by adopting the means of claim 9.
When the influence of the magnetic force from the rotor core to the magnet is small, the provision in this manner can reduce the number of parts and cost.
[0014]
[Means of claim 10]
The means of claim 10 may be employed to magnetize the surface of the magnet on the rotating body side for joining, and join the magnet to the rotating body by the magnetic force magnetized on the rotating body side surface.
With such provision, the work of applying the adhesive becomes unnecessary, and the assembling work becomes easy.
[0015]
[Means of claim 11]
The means of claim 11 may be employed, wherein the rotor is provided with a hole, the magnet is provided with a protrusion, and the magnet is positioned in the hole of the rotor by positioning the magnet with respect to the rotor. .
With such provision, the positioning of the magnet with respect to the rotating body is facilitated.
[0016]
[Means of claim 12]
The means of claim 12 may be employed to provide a projection on the rotating body, provide a hole in the magnet, and fit the hole of the magnet on the projection of the rotating body to position the magnet with respect to the rotating body. .
With such provision, the positioning of the magnet with respect to the rotating body is facilitated.
[0017]
[Means of claim 13]
After the magnet is assembled to the rotating body, the magnet for rotation position detection may be provided on the magnet after adopting the means of claim 13.
With this arrangement, the accuracy of the position of the magnetic pole of the magnet with respect to the rotating body is increased, and the rotation angle detection accuracy of the rotating body can be enhanced.
[0018]
[Means of claim 14]
The means of claim 14 may be adopted, wherein a positioning projection for determining the axial position of the rotor core is provided on the rotating shaft, and a magnet may be joined to the axial end face of the rotor core on the side where the positioning projection is located.
With this arrangement, the accuracy of assembling the magnet in the axial direction of the rotating shaft is increased, and the axial error between the magnet and the magnetic flux change detecting means can be reduced.
[0019]
[Means of claim 15]
The means of claim 15 may be employed, in which the inner ring of the rolling bearing supporting the end of the rotating shaft closer to the magnet is press-fitted and fixed to the rotating shaft, and the outer ring of the rolling bearing is press-fitted and fixed to the housing.
With this arrangement, the accuracy of assembling the magnet in the axial direction of the rotating shaft is increased, and the axial error between the magnet and the magnetic flux change detecting means can be reduced.
[0020]
[Means of claim 16]
A magnetic component for forming a magnetic flux loop in which magnetic flux emitted from the magnet passes through the magnetic flux change detecting means and returns to the magnet may be provided near the magnetic flux change detecting means. good.
With this arrangement, the magnetic flux emitted from the magnet passes through the magnetic flux change detecting means efficiently, so that the magnetic flux change can be detected by the magnetic flux change detecting means even if the magnetic force of the magnet is weak.
[0021]
[Means of claim 17]
In the case of a type in which a signal is generated when a magnetic flux flows from the magnet side to the magnetic flux change detecting means, if the magnetic flux change detecting means is arranged on the rotation angle of the stator teeth which generates the magnetic flux from the stator teeth side to the rotor core side, the rotor core becomes There is a possibility that the magnetic flux change detecting means may erroneously detect the magnetic flux generated.
Therefore, when the means of claim 17 is employed, when a magnetic force is generated in the stator teeth by energizing the coil, the stator teeth generate a magnetic flux from the rotor core side to the stator teeth side. The magnetic flux change detecting means is provided so as to be arranged.
With such a configuration, there is no problem that the magnetic flux change detection unit erroneously detects the magnetic force generated in the rotor core.
[0022]
[Means of Claim 18]
Claim 18 is a case where a magnetic flux change detecting means of the opposite type to that of Claim 17 is used. In the case of a type in which a signal is generated when a magnetic flux flows from the magnetic flux change detecting means to the magnet side, a stator tooth from the rotor core side is used. If the magnetic flux change detecting means is arranged on the rotation angle of the stator teeth that generates magnetic flux toward the side, the magnetic flux change detecting means may erroneously detect the magnetic flux generated by the rotor core.
Therefore, when the means of claim 18 is employed, when a magnetic force is generated in the stator teeth by energizing the coil, the stator teeth generate a magnetic flux from the stator teeth side to the rotor core side. The magnetic flux change detecting means is provided so as to be arranged.
With such a configuration, there is no problem that the magnetic flux change detection unit erroneously detects the magnetic force generated in the rotor core.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described using examples and modifications.
〔Example〕
In this embodiment, the present invention is applied to a rotation angle detecting device of an electric motor that generates power for switching in a shift range switching device of an automatic transmission (including a switching device of a parking switching mechanism). The outline of the range switching device will be described.
[0024]
As shown in FIG. 2, the shift range switching device includes a rotating machine 1, a speed reducer 2, a load to be controlled (hereinafter, shift range switching mechanism 3), a rotation angle detecting device 4, and a control circuit 5. The control circuit 5 controls the shift range switching mechanism 3 driven via the speed reducer 2 by detecting the rotation output angle of the rotating machine 1 using the rotation angle detection device 4.
[0025]
(Description of rotating machine 1)
The rotating machine 1 is a synchronous motor that generates power for switching, and will be described in detail with reference to FIGS. This embodiment will be described with the right side of FIG. 4 as front (or front) and the left side as rear (or rear).
The rotating machine 1 includes a rotor 6 rotatably supported, and a stator 7 arranged coaxially with the rotation center of the rotor 6.
[0026]
The rotor 6 includes a rotating shaft 8 and a rotor core 9, and the rotating shaft 8 is rotatably supported by rolling bearings (a front rolling bearing 10 and a rear rolling bearing 11) disposed at a front end and a rear end. .
The front rolling bearing 10 is arranged on the inner periphery of the output shaft 12 of the reduction gear 2, and the output shaft 12 of the reduction gear 2 is rotatable by a metal bearing 14 arranged on the inner periphery of the front housing 13. It is supported by. That is, the front end of the rotating shaft 8 is rotatably supported via the metal bearing 14 → the output shaft 12 → the front rolling bearing 10 provided in the front housing 13.
On the other hand, the rear rolling bearing 11 rotatably supports the end of the rotating shaft 8 on the side closer to the rotation angle detecting device 4, and the details of the rear rolling bearing 11 will be described later.
[0027]
The stator 7 includes a stator core 16 and a coil 17 (specifically, coils 17A to 17L). The stator core 16 is provided with stator teeth 18 projecting at every 30 degrees toward the rotor 6, and coils 17A to 17L are wound around each of the stator teeth 18 (specifically, stator teeth 18A to 18L). Has been turned. Here, the coils 17A, 17D, 17G, and 17J are in the U phase, the coils 17B, 17E, 17H, and 17K are in the V phase, and the coils 17C, 17F, 17I, and 17L are in the W phase.
[0028]
On the other hand, the rotor core 9 is provided with salient poles 19A to 19H protruding toward the stator 7 at every 45 degrees. When the energization is switched in the order of W phase → V phase → U phase from the state of FIG. 3, the rotor 6 rotates clockwise. Conversely, when the energization is switched in the order of V phase → W phase → U phase, the rotor 6 rotates. The rotor 6 rotates counterclockwise, and the rotor 6 rotates 45 degrees each time the U, V, and W phases are energized.
[0029]
(Description of reduction gear 2)
The speed reducer 2 of the present embodiment employs a cycloid speed reducer, and includes an internal gear 21, an external gear 22 and an output shaft 12, as shown in FIG.
The internal gear 21 is fixed to the front housing 13.
The external gear 22 has a smaller number of teeth than the internal gear 21. Further, the external gear 22 is rotatably supported by an eccentric portion 23 of the rotary shaft 8 via a bearing 24, and the external gear 22 eccentrically rotates as the rotary shaft 8 rotates. When the rotating shaft 8 rotates and the external gear 22 rotates eccentrically, the external gear 22 rotates at a reduced speed with respect to the rotating shaft 8, and the reduced rotation is transmitted to the output shaft 12. The output shaft 12 is connected to a control rod 25 (described later) of the shift range switching mechanism 3.
[0030]
(Description of shift range switching mechanism 3)
The shift range switching mechanism 3 (including the parking switching mechanism 30) is switched by the output shaft 12 of the speed reducer 2 described above, and the shift range switching mechanism 3 will be described with reference to FIG.
Switching of each shift range (P, R, N, D) in the automatic transmission is performed by sliding displacement of the manual spool valve 31 to an appropriate position corresponding to the switching.
[0031]
On the other hand, the locking and unlocking of the parking switching mechanism 30 is performed by engaging and disengaging the concave portion 32a of the park gear 32 and the convex portion 33a of the park pole 33. The park gear 32 is connected to an output shaft of an automatic transmission (not shown) through a differential gear (not shown). The driving wheels of the vehicle are locked by restricting the rotation of the park gear 32, and the parking lock is locked. The state is achieved.
[0032]
A detent plate 34 having a substantially fan shape is attached to the control rod 25 by driving a spring pin (not shown) or the like.
The detent plate 34 is provided with a plurality of recesses 34a at the radial end (substantially arcuate arc portion), and is switched by a leaf spring 36 fixed to the hydraulic control box 35 being fitted into the recess 34a. The set shift range is maintained.
[0033]
Pins 37 for driving the manual spool valve 31 are attached to the detent plate 34.
The pin 37 is engaged with a groove 38 provided at the end of the manual spool valve 31, and when the detent plate 34 is rotated by the control rod 25, the pin 37 is driven to rotate in an arc, and The engaged manual spool valve 31 makes a linear movement inside the hydraulic control box 35.
[0034]
When the control rod 25 is rotated clockwise as viewed from the direction of arrow A in FIG. 5, the pin 37 pushes the manual spool valve 31 into the hydraulic control box 35 via the detent plate 34, and the hydraulic control box 35 The oil passage is switched in the order of D → N → R → P. That is, the range of the automatic transmission is switched in the order of D → N → R → P.
When the control rod 25 is rotated in the reverse direction, the pin 37 pulls out the manual spool valve 31 from the hydraulic control box 35, and the oil passage in the hydraulic control box 35 is switched in the order of P → R → N → D. That is, the range of the automatic transmission is switched in the order of P → R → N → D.
[0035]
On the other hand, a park rod 39 for driving the park pole 33 is attached to the detent plate 34. A conical portion 40 is provided at the tip of the park rod 39.
The conical portion 40 is interposed between the projecting portion 41 of the transmission housing and the park pole 33. When the control rod 25 is rotated clockwise as viewed from the direction of arrow A in FIG. (R → P range), the park rod 39 is displaced in the direction of arrow B in FIG. 5 via the detent plate 34, and the conical portion 40 pushes up the park pole 33. Then, the park pole 33 rotates about the shaft 42 in the direction of arrow C in FIG. 5, the projection 33a of the park pole 33 engages with the recess 32a of the park gear 32, and the locked state of the parking switching mechanism 30 is achieved. .
[0036]
When the control rod 25 is rotated in the opposite direction (specifically, from P to R range), the park rod 39 is pulled back in the direction opposite to the direction of arrow B in FIG. Since the park pole 33 is constantly urged by a torsion coil spring (not shown) in the direction opposite to the direction of arrow C in FIG. 5, the projection 33a of the park pole 33 comes off the recess 32a of the park gear 32, and the park gear 32 is free. , And the parking switching mechanism 30 is unlocked.
[0037]
(Description of rotation angle detection device 4)
The rotation angle detection device 4 is an incremental encoder, and as shown in FIG. 4, a magnet 51 rotating integrally with the rotor 6 and a magnetic flux change detection means 52 fixed to the rear housing 15 (specifically, First to third magnetic flux change detecting means 52A, 52B, and 52Z).
The magnet 51 has a substantially ring shape, and is arranged coaxially with the rotation shaft 8 of the rotor 6 as shown in FIG.
As shown in FIG. 7, the magnet 51 is magnetized such that the N pole and the S pole are repeatedly multipolarized in the rotation direction of the rotor 6, and emitted from the N pole in a direction substantially parallel to the rotation shaft 8. The magnetic flux returns to the south pole.
[0038]
Specific magnetization will be described.
As shown in FIG. 7, the N pole and the S pole are repeatedly magnetized at a pitch of 7.5 degrees in the magnet 51, and the N pole and the S pole magnetized on the outer peripheral side of the magnet 51. By repeating, an A-phase output and a B-phase output for detecting a precise rotation angle of the rotor 6 are obtained.
[0039]
On the inner peripheral side of the magnet 51, inner peripheral projections 51a are provided at 45-degree intervals. An S pole is magnetized at the center of the inner peripheral projection 51a, and N poles are magnetized on both sides in the rotation direction. Configuration. The Z-phase output for obtaining the synchronization signal of the rotating machine 1 is obtained by the magnetic pole change by the inner peripheral projection 51a.
[0040]
The first to third magnetic flux change detecting means 52A, 52B, and 52Z detect magnetic flux emitted from the magnet 51, and are constituted by an element for detecting a magnetic flux change such as a Hall IC, a Hall element, and an MRIC. It is attached to the rear housing 15 via 53. The method of attaching the substrate 53 will be described later.
Further, the first to third magnetic flux change detecting means 52A, 52B, 52Z are attached to the substrate 53 as shown in FIG. 9 to detect the A phase, the B phase, and the Z phase (see FIG. 8), respectively. I have.
[0041]
The first and second magnetic flux change detecting means 52A and 52B detect the A phase and the B phase, respectively, and are disposed on a circumference facing the outer peripheral portion of the magnet 51, and the magnetic flux at the outer peripheral portion of the magnet 51 is provided. An A-phase output and a B-phase output are obtained by the change.
The third magnetic flux change detecting means 52Z detects the Z phase, is arranged on a circumference facing the inner peripheral projection 51a of the magnet 51, and obtains a Z phase output by a magnetic flux change received from the inner peripheral projection 51a. Things.
[0042]
Next, the A-phase, B-phase, and Z-phase output waveforms by the rotation angle detection device 4 will be described with reference to FIGS.
The A phase and the B phase are output signals having a phase difference of 90 degrees in electrical angle. In this embodiment, each time the rotor 6 rotates 15 degrees, the A phase and the B phase are output one cycle each. It is configured.
The Z phase is an index pulse that is output once each time the rotor 6 rotates 45 degrees, and the Z phase can define the relative positional relationship between the energized phase of the rotating machine 1 and the A and B phases.
[0043]
Next, the rotation angle detection device 4 will be described in more detail.
As shown in FIG. 1A, each magnetic flux change detecting means 52 is disposed on the surface of the substrate 53 covered by the rear housing 15 on the opposite side of the magnet 51 (the left side of the substrate 53 in FIG. 1). A protection layer 55 for covering the magnetic flux change detecting means 52 and the circuit pattern 54 (see FIG. 9) is formed on the surface of the substrate 53 on which the magnetic flux change detecting means 52 is mounted. ing. Note that the protective layer 55 is formed by sealer coating or the like.
[0044]
The substrate 53 is made of a non-magnetic metal plate 56 (for example, aluminum or stainless steel) and an insulating resin material (for example, polyimide) provided on the surface of the metal plate 56 opposite to the magnet 51. And the like, and a circuit pattern 54 is formed by a printing technique on a surface of the film substrate 57 that does not touch the metal plate 56.
[0045]
As shown in FIG. 10, a terminal terminal 58 for connecting the board, which protrudes toward the board 53, is provided on the rear housing 15 facing the magnet 51 on the board 53.
On the other hand, the film substrate 57 on which the circuit pattern 54 is printed has no metal plate 56 in a portion below the straight line A shown in FIG. This part of the film substrate 57 is hereinafter referred to as a lead film 57a.
[0046]
The lead film 57a is turned 180 degrees in the XX part of FIG. 9A, and the leading end of the lead film 57a is connected to the terminal terminal 58 as shown in FIG.
With this arrangement, the solder land 57b to be soldered to the terminal terminal 58 can be formed on the same surface as the circuit pattern 54 (the surface A in FIG. 9). That is, since the film substrate 57 may be a single-sided substrate, the manufacturing cost of the substrate 53 can be reduced.
[0047]
Here, an example in which the lead film 57a is not inverted by 180 degrees will be described with reference to FIG. The portion within the broken line shown in FIG. 11A is the lead film 57a.
When provided as shown in FIG. 11, the through holes 57c formed in the lead film 57a can be connected to the terminal terminals 58 without inverting the lead film 57a.
However, it is necessary to use a double-sided board in which soldering lands 57b are formed on a surface (surface B in FIG. 11) of the film substrate 57 different from the circuit pattern 54.
[0048]
In this embodiment, as shown in FIGS. 9 and 11, a magnetic flux change detecting means 52 and peripheral circuits (such as a noise filter capacitor 59) associated with the magnetic flux change detecting means 52 are mounted on a substrate 53. Although an example of arrangement is shown, a peripheral circuit may be provided as an integrated module, and the module may be provided on the surface of the substrate 53 opposite to the magnet 51.
[0049]
A plurality of mounting holes 53a are formed in the outer peripheral portion of the substrate 53. After fitting the mounting holes 53a to the resin protrusions 15a of the rear housing 15 (see FIG. 4), the protrusions 15a are heat-sealed. By doing so, the substrate 53 is fixed to the rear housing 15.
[0050]
As shown in FIG. 6, the magnet 51 is joined to the axial end face of the rotor core 9. Therefore, when the magnetic force exerted on the magnet 51 from the rotor core 9 is large, a non-magnetic film member (not shown) is used. The magnet 51 is joined to the rotor core 9 through the not shown).
When the influence of the magnetic force from the rotor core 9 on the magnet 51 is small, the magnet 51 is directly joined to the rotor core 9. As a result, the number of parts can be reduced, and the cost can be reduced.
[0051]
The magnet 51 of this embodiment is made of an inexpensive ferrite plastic magnet, for example, and has a predetermined thickness in the axial direction. The magnet 51 is magnetized for joining on the joining surface of the rotor core 9 and joined to the rotor core 9 by the magnetic force magnetized on the surface on the rotor core 9 side.
With such provision, the work of applying an adhesive when the magnet 51 is joined to the rotor core 9 becomes unnecessary, and the assembling work becomes easy.
[0052]
Next, the assembly of the magnet 51 will be described.
As shown in FIG. 12, holes 9 a for magnet positioning are provided at 45 ° intervals radially extending from the center of rotation on the axial end surface of the rotor core 9. On the other hand, projections 51d at 90-degree intervals are also provided on the joint surface of the magnet 51. Then, the projection 51d of the magnet 51 is inserted into the hole 9a of the rotor core 9 for assembly.
By performing such assembling, the magnet 51 can be easily assembled coaxially with the rotation center of the rotor core 9.
Contrary to the above, the same effect can be obtained by providing a projection on the rotor core 9, providing a hole in the magnet 51, and positioning the magnet 51 with respect to the rotor core 9 by fitting them together. .
[0053]
As shown in FIG. 13, after the magnet 51 is joined to the rotor core 9, magnetization for rotational position detection is performed on a surface different from that of the rotor core 9.
With such provision, the accuracy of the magnetic pole position of the magnet 51 with respect to the rotor core 9 is improved, and the rotation angle detection accuracy of the rotation angle detection device 4 can be increased.
[0054]
Next, the attachment of the rotor core 9 to the rotating shaft 8 will be described.
The rotor core 9 is formed by laminating a large number of thin plates, and is press-fitted and fixed to the rotating shaft 8 as shown in FIG.
Here, a positioning projection 8a for determining the axial position of the rotor core 9 is provided on the rear side of the rotating shaft 8, that is, on the side to which the magnet 51 is joined, as shown in FIG. The positioning projection 8a is provided such that the axial end face of the rotor core 9 coincides with the positioning projection 8a.
With this arrangement, as shown in FIG. 13, even when the lamination thickness L of the rotor core 9 changes, the mounting position of the magnet 51 in the axial direction of the rotating shaft 9 does not change. For this reason, the assembling accuracy of the magnet 51 is improved, and the axial error between the magnet 51 and the magnetic flux change detecting means 52 can be reduced.
[0055]
The rear side of the rotating shaft 8, that is, the side to which the magnet 51 is joined, is supported by a rear housing 15 via a rear rolling bearing 11. Therefore, when the rear rolling bearing 11 slides in the axial direction, the axial distance between the magnet 51 and the magnetic flux change detecting means 52 changes.
Therefore, the inner ring 11a of the rear rolling bearing 11 shown in FIG. 13 is press-fitted and fixed to the rotating shaft 8, and the outer ring 11b of the rolling bearing 11 is press-fitted and fixed to the rear housing 15 (see FIG. 4).
With such provision, the accuracy of managing the axial distance between the magnet 51 and the magnetic flux change detecting means 52 is increased, and deterioration of the detection accuracy of the rotation angle detecting device 4 can be prevented.
[0056]
Here, the magnetic flux change detecting means 52 used in this embodiment is of a type that generates a signal when a magnetic flux flowing from the magnetic flux change detecting means 52 toward the magnet 51 flows, as shown in FIG.
When the magnetic flux change detecting means 52 of this type is used, if the magnetic flux change detecting means 52 is arranged on the rotation angle of the stator teeth 18 which generates a magnetic flux from the rotor core 9 toward the stator teeth 18, the magnetic flux change detecting means 52 generates There is a possibility that the magnetic flux change detecting means 52 may erroneously detect due to the generated magnetic flux.
[0057]
Therefore, in this embodiment, as shown in FIG. 15, when a magnetic force is generated in the stator teeth 18 by energizing the coil 17, the rotation about the center of the stator teeth 18 H that generates a magnetic flux toward the rotor core 9 is performed. The third magnetic flux change detecting means 52Z is disposed on the angle, and the first magnetic flux change detecting means 52A is disposed on a rotation angle substantially at the center of the stator teeth 18J that generate magnetic flux toward the rotor core 9 side. The second magnetic flux change detecting means 52B is provided so as to be disposed at a rotation angle substantially at the center of the stator teeth 18L that generate a magnetic flux toward the second magnetic field.
With such provision, there is no problem that the first to third magnetic flux change detecting means 52A, 52B, 52Z erroneously detect due to the magnetic force generated in the rotor core 9.
[0058]
The above will be described with reference to FIGS.
As shown in FIG. 16, the third magnetic flux change detecting means 52Z is disposed at a rotation angle substantially at the center of the stator teeth 18H that generate magnetic flux toward the rotor core 9 side. As shown, even if the magnetic flux applied to the rotor core 9 from the stator teeth 18H passes through the third magnetic flux change detecting means 52Z, the third magnetic flux change detecting means 52Z detects a magnetic flux change in the opposite direction, and thus malfunctions. do not do.
Then, as shown in FIG. 17, when the inner peripheral projection 51a of the magnet 51 passes through the position facing the third magnetic flux change detecting means 52Z, the third magnetic flux change detecting means 52Z emitted from the inner peripheral projection 51a The Z phase is detected by the magnetic flux heading toward the inner peripheral projection 51a.
A bobbin case 60 in FIGS. 16 and 17 is mounted on the stator teeth 18 after winding the coil 17 around the bobbin case 60.
[0059]
In this embodiment, the case where the magnetic flux change detecting means 52 of a type that generates a signal when a magnetic flux flowing from the magnetic flux change detecting means 52 toward the magnet 51 flows is used. On the other hand, when the magnetic flux change detecting means 52 of a type that generates a signal when a magnetic flux flowing from the magnet 51 to the magnetic flux change detecting means 52 flows is used, when a magnetic force is generated by energizing the stator teeth 18 through the coil 17. Next, the magnetic flux change detecting means 52 is arranged at a rotation angle substantially at the center of the stator teeth 18 that generates a magnetic flux from the rotor core 9 toward the stator teeth 18.
With such provision, erroneous detection of the magnetic flux change detecting means 52 can be prevented.
[0060]
Further, in this embodiment, as shown in FIG. 18, a loop of the magnetic flux emitted from the magnet 51 and passing through the magnetic flux change detecting means 52 and returning to the magnet 51 is formed near the magnetic flux change detecting means 52. (For example, a metal core made of iron). Reference numeral 62 shown in FIG. 18 is a metal component molded on the rear housing 15.
By providing the magnetic component 61, the magnetic flux emitted from the magnet 51 efficiently passes through the magnetic flux change detecting means 52, so that the magnetic flux change can be detected by the magnetic flux change detecting means 52 even if the magnetic force of the magnet 51 is weak.
[0061]
(Effects of the embodiment)
The rotation angle detection device 4 mounted in this embodiment is disposed in the case of the rotating machine, but adopts a configuration in which the magnetic flux change detection means 52 is disposed on the side of the substrate 53 opposite to the magnet 51. Thus, as shown in FIG. 1 (A), oil and metal powder flying from the magnet 51 side are guarded by the substrate 53, and the magnetic flux change detecting means 52 is protected.
As a result, the distance x between the magnetic flux detection area α in the magnetic flux change detection means 52 and the magnet 51 can be shortened, and the conventionally used potting J6 for protecting the magnetic flux change detection means 52 can be eliminated.
[0062]
As described above, since the distance x between the magnetic flux detection area α and the magnet 51 can be reduced, it is possible to reduce the influence of temperature on the detection accuracy, and as a result, the detection accuracy of the rotation angle detection device 4 can be increased. it can.
Further, since the distance x between the magnetic flux detection area α and the magnet 51 can be reduced, even if the magnetic force of the magnet 51 is not strong, it is possible to detect a change in magnetic flux in the magnetic flux detection area α. Inexpensive ferrite-based plastic magnets can be used instead of expensive rare earth elements, and the cost can be reduced.
Furthermore, the expensive potting J6 conventionally used is eliminated, and the surface of the substrate 53 opposite to the magnet 51 is covered with an inexpensive protective layer 55 (for example, a sealer), whereby the substrate 53 is mounted on the substrate 53 from dew condensation water or oil. It is possible to protect the magnetic flux change detecting means 52, the circuit pattern 54, and the like, which are performed, and it is possible to reduce costs.
[0063]
(Modification)
In the above embodiment, an example in which the present invention is applied to the switching device of the shift range switching mechanism 3 (including the parking switching mechanism 30) has been described. However, the present invention is applicable to an apparatus that detects the rotation angle of a rotating body. It may be provided to detect the rotation angle of the rotating body for other uses.
In the above-described embodiment, the example in which the magnet 51 is joined to the rotor core 9 has been described. However, the partner to which the magnet 51 is joined may be any rotating member, and the magnet 51 is joined to a rotating object other than the rotor core 9 to rotate the magnet 51. May be provided.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of a rotation angle detection device.
FIG. 2 is a schematic configuration diagram of a shift range switching device.
FIG. 3 is a schematic configuration diagram of a rotating machine.
FIG. 4 is a sectional view of a unit in which a rotating machine, a speed reducer, and a rotation angle detecting device are combined.
FIG. 5 is a perspective view of a shift range switching mechanism including a parking switching mechanism.
FIG. 6 is a perspective view of a rotor on which a magnet is mounted.
FIG. 7 is a plan view of a magnet showing a magnetized state.
FIG. 8 is an output waveform diagram of A, B, and Z phases when the rotor rotates.
FIG. 9 is a plan view and a side view of a substrate.
FIG. 10 is a cross-sectional view of a main part showing a connection portion between a substrate and a terminal.
FIG. 11 is a plan view and a side view of a substrate.
FIG. 12 is an assembly diagram of a magnet.
FIG. 13 is a sectional view of a rotor.
FIG. 14 is an assembly diagram of a rotating shaft and a rotor core.
FIG. 15 is an explanatory diagram showing a mounting position of a magnetic flux change detecting unit.
FIG. 16 is a sectional view taken along line XX of FIG. 15;
FIG. 17 is a cross-sectional view showing a state in which an inner circumferential protrusion of the magnet approaches the magnetic flux change detecting means.
FIG. 18 is a sectional view taken along the line YY in FIG. 15;
[Explanation of symbols]
1 rotating machine
4 Rotation angle detector
6 rotor
8 Rotary axis of rotor
8a Positioning protrusion
9 Rotor core
9a Hole in rotor core
11 Rolling bearing
11a Inner ring
11b Outer ring
15 Rear housing
17 coils
18 Stator teeth
51 magnet
51d Magnet projection
52 Magnetic flux change detecting means
53 substrate
54 Circuit Pattern
55 protective layer
56 metal plate
57 film substrate
57a Lead film (Film substrate protruding from metal plate)
57b Soldering land
58 Terminal terminal
59 Capacitor
61 Magnetic parts

Claims (18)

A magnet that is arranged concentrically with the rotation axis of the rotating body and is multipolarly magnetized in the rotation direction of the rotating body;
Magnetic flux change detecting means for detecting a change amount of magnetic flux emitted by the magnet;
A substrate for arranging the magnetic flux change detecting means at a position for receiving the magnetic flux of the magnet;
A housing that covers the substrate on which the magnetic flux change detection unit is mounted from the opposite side of the magnet;
A rotation angle detection device comprising:
The rotation angle detection device according to claim 1, wherein the magnetic flux change detection unit is disposed on a side of the substrate opposite to the magnet. The rotation angle detection device according to claim 1,
The rotation angle detector is characterized in that the rotating body is a rotor in a rotating machine such as an electric motor or a generator. The rotation angle detection device according to claim 2,
The rotation angle detecting device, wherein the magnet is provided so as to be joined to a rotor core constituting the rotor. The rotation angle detection device according to claim 1,
A rotation angle detecting device, wherein a protective layer covering the magnetic flux change detecting means and a circuit pattern is formed on a surface of the substrate on which the magnetic flux change detecting means is mounted, opposite to the magnet. The rotation angle detection device according to any one of claims 1 to 4,
The substrate includes a non-magnetic metal plate and an insulating film substrate provided on a surface of the metal plate opposite to the magnet,
A rotation angle detection device, wherein a circuit pattern is printed on a surface of the film substrate that does not touch the metal plate. The rotation angle detection device according to claim 5,
The housing facing the opposite side of the magnet of the board is provided with a terminal terminal for board connection protruding toward the board,
The film substrate on which the circuit pattern is printed is provided so as to partially protrude from the metal plate,
The rotation angle detecting device, wherein the protruding portion of the film substrate is inverted by 180 degrees and connected to the terminal terminal. The rotation angle detection device according to any one of claims 1 to 6,
A module integrating the magnetic flux change detecting means and peripheral circuits such as a reference power supply and a noise filter capacitor attached to the magnetic flux change detecting means,
A rotation angle detecting device, wherein the module is arranged on a surface of the substrate opposite to the magnet. The rotation angle detection device according to claim 3,
A rotation angle detecting device, wherein the magnet is joined to the rotor core via a non-magnetic film member. The rotation angle detection device according to claim 3,
The rotation angle detection device according to claim 1, wherein the magnet is directly joined to the rotor core. The rotation angle detection device according to any one of claims 1 to 9,
A rotation angle detecting device, wherein the magnet is magnetized for bonding on a surface on the rotating body side and is bonded to the rotating body by a magnetic force magnetized on the surface on the rotating body side. The rotation angle detection device according to any one of claims 1 to 10,
A hole is provided in the rotating body, and a protrusion is provided on the magnet,
A rotation angle detection device, wherein the magnet is positioned with respect to the rotating body by inserting a projection of the magnet into a hole of the rotating body. The rotation angle detection device according to any one of claims 1 to 10,
Providing a projection on the rotating body, providing a hole in the magnet,
A rotation angle detecting device, wherein the magnet is positioned with respect to the rotating body by fitting a hole of the magnet into a projection of the rotating body. The rotation angle detection device according to any one of claims 1 to 12,
A rotation angle detecting device, wherein after the magnet is attached to the rotating body, the magnet is magnetized for detecting a rotational position. The rotation angle detection device according to claim 3,
The rotation angle detection device, wherein the rotation shaft includes a positioning protrusion for determining an axial position of the rotor core, and the magnet is joined to an axial end surface of the rotor core on a side where the positioning protrusion is located. . In the rotation angle detection device according to any one of claims 1 to 14,
An end of the rotating shaft closer to the magnet is supported by the housing via a rolling bearing,
A rotation angle detecting device, wherein an inner ring of the rolling bearing is press-fitted and fixed to the rotary shaft, and an outer ring of the rolling bearing is press-fitted and fixed to the housing. The rotation angle detection device according to any one of claims 1 to 15,
In the vicinity of the magnetic flux change detecting means, a magnetic component for forming a loop of magnetic flux emitted from the magnet and returning to the magnet through the magnetic flux change detecting means is provided. Rotation angle detection device. The rotation angle detection device according to claim 3,
When the magnetic flux change detection means is of a type that generates a signal when a magnetic flux flows from the magnet side,
When a magnetic force is generated in the stator teeth by energizing the coils, the magnetic flux change detecting means is disposed on a rotation angle substantially at the center of the stator teeth that generates a magnetic flux from the rotor core toward the stator teeth. A rotation angle detection device characterized by the above-mentioned. The rotation angle detection device according to claim 3,
When the magnetic flux change detecting means is of a type that generates a signal when a magnetic flux flowing from the magnetic flux change detecting means toward the magnet flows,
When a magnetic force is generated by energizing a coil in the stator teeth, the magnetic flux change detecting means is disposed at a rotation angle substantially at the center of the stator teeth that generates a magnetic flux from the stator teeth toward the rotor core. A rotation angle detection device characterized by the above-mentioned.

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