JP2008045913A - Rotation angle detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation angle detector having proper assemblability and maintainability. <P>SOLUTION: The rotation angle detector 800 for detecting the rotation angle of a rotating element 150 comprises a rotation angle sensor 100 (200, 300, or the like) having the main part which is radially split into two parts. The rotation sensor comprises a rotor 104 corotating with the rotating element, a stator 106, and a coil (an exciting coil and a detecting coil) 108, and the rotation angle detector detects the rotation angle of the rotating element, by using magnetic flux resistance which changes periodically with the rotation of the rotor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device that detects a rotation angle of a rotating body.

Conventionally, a rotation angle is characterized in that a housing is formed by joining a plurality of divided housings in which a through hole is provided in the axial direction and a resolver is accommodated in the through hole in the axial direction. A sensor is known (see, for example, Patent Document 1).
JP 2005-43140 A

  However, since the conventional rotation angle detection device has a configuration in which the rotation shaft is inserted into and removed from the central hole of the rotation angle detection device, as in the invention described in Patent Document 1 above, assembly and maintenance are possible. There is a problem that the nature is bad. For example, when removing the rotation angle detection device from the rotation shaft, if other components are attached to the rotation shaft, remove the other components and then move the rotation angle detection device along the axial direction of the rotation shaft. It is necessary to remove it, and the work becomes complicated.

  In view of the above, an object of the present invention is to provide a rotation angle detection device with good assemblability and maintainability.

In order to achieve the above object, a first invention is a rotation angle detection device for detecting a rotation angle of a rotating body,
A rotation angle sensor having a main body divided in two in the radial direction is provided. Thereby, the assembly property between a rotary body and a rotation angle sensor, and the maintainability of a rotation angle sensor improve.

2nd invention is the rotation angle detection apparatus which concerns on 1st invention,
The rotation angle sensor includes a rotor that rotates together with a rotating body, a stator, an excitation coil, and a detection coil, and the rotation angle detection device rotates using a magnetic flux resistance that periodically changes as the rotor rotates. When detecting the rotation angle of the body,
The rotation angle detection device includes a signal processing unit that processes an output signal input from the detection coil and outputs rotation angle information of the rotating body,
The signal processing unit generates the rotation angle information of the rotating body using the characteristics of the output signal generated due to the joint of the divided rotors. Thereby, angle detection accuracy can be improved using the division structure of a rotor.

3rd invention is the rotation angle detection apparatus which concerns on 1st or 2nd invention,
The diameter of the rotor is determined so as to change according to a substantially sine wave function in which the rotation angle of the rotor is a variable and the period is determined by the shaft angle multiplier,
The rotor is characterized in that it is divided so that the two features of the output signal due to both sides of the split rotor seam appear at different phases in the sinusoidal function. As a result, the characteristics of the two points of the output signal (two points corresponding to both sides of the divided rotor joints) are generated in different phases, so that they are not confused. Therefore, when the characteristics of the two output signals are used, the opportunity for correction can be ensured twice in one cycle of the mechanical angle.

2nd invention is the rotation angle detection apparatus which concerns on 1st-3rd invention,
The rotor is characterized in that the rotor is configured to change abruptly at the joint where the diameter is divided. Thereby, the feature of the output signal is emphasized, and the appearance of the feature can be detected with high accuracy.

  According to the present invention, it is possible to obtain a rotation angle detection device that is particularly easy to assemble and maintain. Further, the angle detection accuracy can be improved by utilizing the divided structure of the rotor.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a two-plane view showing an embodiment of a rotation angle sensor 100 in the rotation angle detection device according to the present invention, and FIG. 1 (A) is a plan view of the rotation angle sensor 100 in an assembled state. FIG. 2B is a side view of the rotation angle sensor 100. FIG. The rotation angle sensor 100 of the present embodiment may be used for detecting the rotation angle of the steering shaft, for example.

  The rotation angle sensor 100 is configured as, for example, a VR type (variable reluctance) resolver, and is disposed coaxially with respect to the rotation axis of a rotating body 150 (for example, a steering shaft) that is a detection target of the rotation angle.

  FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 2A is a cross-sectional view of the rotation angle sensor 100 of the present embodiment, and FIG. It is sectional drawing of the rotation angle sensor 200 of other Examples.

  The rotation angle sensor 100 includes a casing (housing cover) 102. The casing 102 has an annular shape in the assembled state. The casing 102 may be manufactured by injection molding a resin material such as PBT (Polybutylene terephthalate).

  As shown in FIG. 2A, the rotor 102, the stator 106, the coil 108, and the bearings 110 and 112 that rotate together with the rotating body 150 are accommodated in the casing 102. The casing 102 is fixedly supported on the vehicle body via a bracket (not shown).

  When the rotation angle sensor 100 is a one-phase input / two-phase output type sensor, the coil 108 includes an excitation coil and two detection coils (sin phase and cos phase output coils).

  The stator 106 is made of an iron-based magnetic material, and is assembled on the outer peripheral side in the casing 102. The stator 106 has an annular shape in an assembled state (a closed state of the rotation angle sensor 100 shown in FIG. 1). The stator 106 has a plurality of protrusions (teeth) protruding toward the rotation center along the circumferential direction. An excitation coil and a detection coil are appropriately wound around the protrusion.

  The bearings 110 and 112 are assembled on the inner peripheral side of the casing 102. The bearings 110 and 112 are arranged in an annular shape around the rotating body 150 in the assembled state (the rotation angle sensor 100 shown in FIG. 1 is closed), and support the rotating body 150 rotatably with respect to the casing 102.

  As shown in FIG. 2A, the casing 102 is formed with a protrusion 103 that is convex in the axial direction on the surface facing the rotor 104 along the circumferential direction. The protrusion 103 is slidably fitted in a circumferential groove 109 formed in a corresponding portion of the rotor 104, and functions to define a rotation trajectory of the rotor 104. However, as in the rotation angle sensor 200 according to another embodiment shown in FIG. 2B, the rotation trajectory of the rotor can be maintained by the spacer 202 instead of the protrusion.

  The rotation angle sensor 100 is configured by aligning two substantially symmetric portions in the radial direction along the dividing line T shown in FIG. That is, the rotation angle sensor 100 has a configuration that is divided into two in the radial direction. In the following description, the symbol “L” is added to the end of the reference symbol of the component of one part, and the symbol “R” is added to the end of the reference symbol of the component of the other portion.

  In such a divided configuration, the rotor 104L, the stator 106L, the coil 108L, and the bearings 110L and 112L are accommodated in the casing 102L. The casing 102L is integrated with the stator 106L, the coil 108L, and the bearings 110L and 112L (in a state where these components are assembled) to constitute one half of the main body of the rotation angle sensor 100.

  Similarly, the rotor 104R, the stator 106R, the coil 108R, and the bearings 110R and 112R are accommodated in the casing 102R. The casing 102R is integrated with the stator 106R, the coil 108R, and the bearings 110R and 112L to form the other half of the body of the rotation angle sensor 100.

  FIG. 3 is a diagram illustrating an open state of the rotation angle sensor 100 of the present embodiment. In FIG. 3, in order to show the inside of the rotation angle sensor 100, the part B is shown in a partially cut state.

  As shown in FIG. 3, the rotation angle sensor 100 is preferably configured to be openable and closable in the radial direction in a state where the two divided parts are connected to each other. Specifically, the casing 102L and the casing 102R are configured to be openable and closable in the radial direction via a hinge portion 122 that connects the casing 102R so as to be openable and closable. In the illustrated configuration, the casing 102 </ b> L and the casing 102 </ b> R are configured to be rotatable around the rotation shaft 123 while being connected to each other via a hinge portion 122.

  The dividing line T is preferably set so as to pass between the teeth of the stator 106 as shown in the drawing in consideration of the assembling property of the coil 108L and the coil 108R. However, the rotation angle sensor 100 does not necessarily have to be divided symmetrically. A preferable setting mode of the dividing line T will be described later.

  4 is an enlarged view of a portion B in FIG. 3, FIG. 4A is a cross-sectional view of the rotation angle sensor 100 of the present embodiment, and FIG. 4B is a rotation angle of the other embodiments. 2 is a cross-sectional view of a sensor 300. FIG.

  The coil 108L and the coil 108R are connected to each other on one side to which the casing 102L and the casing 102R are coupled. On the other hand, the coil 108L and the coil 108R are respectively connected to an AC power source or a signal processing device 700 (described later) (not shown) on the other side. In the illustrated example, the coil 108 </ b> L and the coil 108 </ b> R are not connected to each other on the open side (the upper side in FIG. 3), and are connected to the AC power supply or the signal processing device 700 via a connector (not shown).

  The connection between the coil 108L and the coil 108R may be realized by being wound in a connected state (continuous state) as shown in FIG. That is, the coil 108L and the coil 108R may be formed without dividing the winding on the closed side (the lower side in FIG. 3) in a state where the two stators 106L and 106R forming a pair are combined. Alternatively, like the rotation angle sensor 300 according to another embodiment shown in FIG. 4B, the coil 308L on the stator 306 side and the coil 308R on the stator 308 side are closed (the lower side in FIG. 3) with the connector 360. May be connected to each other via

  FIG. 5 is a diagram showing an example of the shape of the rotor 104, FIG. 5A is a plan view of the rotor 104 of the rotation angle sensor 100 of the present embodiment, and FIG. 5B is another implementation. It is a top view of the rotor 204 of the rotation angle sensor 200 of an example (type without the circumferential groove 109).

  6 is a cross-sectional view taken along line CC in FIG. 5A, and FIGS. 6A and 6B are cross-sectional views showing two different connection modes, respectively. is there.

  FIG. 7 is a cross-sectional view taken along line DD in FIG. 5B, and FIGS. 7A and 7B are cross-sectional views showing two different connection modes, respectively. is there.

  The rotor 104 is made of an iron-based magnetic material. The rotor 104 has a hole 105 through which the rotating body 150 is inserted at the center. In the illustrated example, the hole 105 has a circular shape, and a concave portion 114 is formed in a part of the circular shape, corresponding to a convex portion (not shown) formed on the surface of the rotating body 150. Thereby, the rotation direction of the rotor 104 is constrained with respect to the rotating body 150 and rotates together with the rotating body 150.

  As shown in FIG. 5, the outer contour line of the rotor 104 is defined not by a constant diameter but by a periodically changing diameter in the assembled state (the closed state of the rotation angle sensor 100 shown in FIG. 1). That is, the diameter of the rotor 104 is determined so as to change according to a substantially sinusoidal function whose period is determined by the shaft angle multiplier N, with the rotation angle of the rotor 104 as a variable. The shaft angle multiplier N that defines the diameter change period may be appropriately determined according to the required resolution. In the example shown in the figure, the axial multiplication angle is 3, which is a 3X resolver.

  As described above, the rotor 104 includes two rotors 104L and 104R divided into two. The two rotors 104L and 104R have portions that overlap each other, and at the overlapping portions, as shown in FIGS. 6A and 6B, a fastener 130 (for example, press-fitting a pin or fastening by a screw) Etc.) can be connected to each other. In addition, as shown in FIGS. 1 and 3, the casings 102L and 102R are formed with holes 140 through which the fasteners 130 are inserted.

  Similarly, the rotors 204 of the other embodiments shown in FIG. 5B may also be configured to have portions that overlap each other and can be connected to each other by pins or screws or the like in the overlapping portions.

  As shown in FIG. 5A, the dividing line T in the rotor 104 is preferably such that the points α and β on the outermost circumference (both sides) of the divided rotor are on different diameters (r2 ≠ r1). Decided to come to. Further, preferably, as shown in FIG. 5 (A), the rotor 104 is configured so that the diameter of the rotor 104 changes suddenly at least one of the outermost points α and β of the joint of the divided rotor 104. Configured. In the illustrated example, the rotor 104 has a notch (concave portion) 107 formed at the outermost peripheral point α having the maximum diameter. As a result, the diameter of the rotor 104 changes suddenly at the outermost peripheral point α where the maximum diameter is obtained. The technical significance of these configurations will be described later.

  In addition, for the rotor 204 of another embodiment shown in FIG. 5B, the two points on the outermost periphery (both sides) of the joint of the divided rotor are on different diameters. You may have.

  Next, an assembly mode of the rotation angle sensor 100 and the rotating body 150 having the above configuration will be described. In addition, since it is the same also about the rotation angle sensors 200 and 300 by another Example, description is abbreviate | omitted.

  The assembly method is extremely simple. First, an open state of the rotation angle sensor 100 shown in FIG. 3 is formed, and the rotating body 150 is placed inside the rotation angle sensor 100 (bearing 110) in the direction of the arrow P in FIG. , 112). Next, the rotation angle sensor 100 is closed to form the closed state shown in FIG. Next, the screw 132 (FIG. 1B) is tightened at the connecting portion 124 on the open / close side, and the casings 102 </ b> L and 102 </ b> R are integrated. Further, the overlapping portions of the rotors 104L and 104R are connected by the fastener 130 as described above, and the rotors 104L and 104R are integrated. Thereby, the assembly of the rotation angle sensor 100 and the rotating body 150 is completed.

  FIG. 8 is a view showing a rotation angle sensor 400 according to another embodiment, FIG. 8A is a plan view of the rotation angle sensor 400 in an assembled state (closed state), and FIG. 4 is a side view of the rotation angle sensor 400. FIG. FIG. 9 shows the rotation angle sensor 400 in the open state.

  The rotation angle sensor 400 of the embodiment shown in FIG. 8 is different from the rotation angle sensor 100 according to the above-described embodiment in that the two divided parts are connected to each other by snap fit. The rotation angle sensor 400 has casings 402L and 402R which are divided into two as in the above-described embodiment.

  In the casing 402L, half of the rotor, the stator, the coil, and the bearing are accommodated as in the above-described embodiment. The casing 402L is integrated with these components housed therein (in the state where these components are assembled), and constitutes one half of the body of the rotation angle sensor 400. Similarly, half of the rotor, the stator, the coil, and the bearing are accommodated in the casing 102R. The casing 402 </ b> R is integrated with these components housed inside to constitute one half of the main body of the rotation angle sensor 400.

  The claws 410 are formed on both sides of the casing 402L. A non-engaging portion 412 with which the claw 410 is engaged is formed in the casing 102R. The casing 402L and the casing 102R are connected to each other when the claw 410 is engaged (snap-fit) with the non-engaging portion 412.

  As for the assembly mode, the open state of the rotation angle sensor 400 shown in FIG. 9 is formed, and the rotating body 150 is received inside the rotation angle sensor 400 (inner peripheral side of the bearing). Next, the casing 402L and the casing 102R are combined (see the Q direction in FIG. 9), and the rotation angle sensor 400 is closed to form the closed state shown in FIG. At this time, the casings 402L and 402R are integrated by snap fit. Next, the overlapping portions of the two divided rotors are connected by the fastener 130 in the same manner as in the above-described embodiment, and the two divided rotors are integrated. Thereby, the assembly of the rotation angle sensor 400 and the rotating body 150 is completed.

  As described above, according to the present embodiment (including other embodiments, the same applies hereinafter), the following effects can be obtained.

  First, as described above, the rotation angle sensor 100 (the same applies to the rotation angle sensors 200, 300, and 400) is divided in the radial direction so that the rotation angle sensor 100 and the rotating body 150 are assembled. Becomes easy. For example, in the conventional configuration in which the central hole of the rotation angle sensor is assembled through the shaft from the axial end of the shaft as the rotating body, the stepped shaft is a rotating body 150 as shown in FIG. In some cases, the rotation angle sensor cannot be moved in the axial direction and assembled to a predetermined position due to the step. The same applies to the case where other parts are attached in place of the steps, and the other parts must be assembled after the rotation angle sensor. Such inconvenience occurs not only when the rotation angle sensor is assembled, but also when the rotation angle sensor is replaced (when removed), as indicated in the column “Problems to be Solved by the Invention”. . In contrast, according to the present embodiment, as described above, the rotation angle sensor 100 is divided in the radial direction, so that even a stepped shaft as shown in FIG. Can be assembled directly. That is, according to the present embodiment, the rotation angle sensor 100 can be easily attached to and detached from the rotating body 150 without being affected by the diameter of the rotating body 150 and the components attached to the rotating body 150. The replacement work becomes very easy.

  Further, in the other embodiment shown in FIG. 8 in particular, the casing 402L and the casing 102R are connected to the snap fit by the claw 410, so that fastening by a screw or the like is unnecessary, and the number of work steps is reduced together with the number of parts. be able to.

  Further, since the rotation angle sensor 100 is divided in the radial direction, the winding work for forming the coil 108 is facilitated.

  In addition, distortion occurs in the sine wave output from the coil 108 due to the divided portion (joint) of the rotor 104, so that phase alignment can be performed using the distortion. This will be described in detail below.

  FIG. 11 is a system configuration diagram showing an embodiment of the rotation angle detection device 800 according to the present invention. The rotation angle detection device 800 includes the rotation angle sensor 100 described above. As the rotation angle sensor, instead of the rotation angle sensor 100, rotation angle sensors 200, 300, and 400 according to other embodiments may be used.

  The rotation angle detection device 800 includes a signal processing unit 700 that processes an output signal from the rotation angle sensor 100 and outputs rotation angle information of the rotating body 150.

  The signal processing unit 700 includes a resolver digital converter 710 (hereinafter referred to as “R / D 710”), a zero point pass determination unit 720, and a zero point count-up correction unit 730. The function of the zero point passage determination unit 720 may be realized by a microcomputer as in the case of the function of the zero point count up correction unit 730, or may be realized by hardware using an IC or the like. Also, the zero point passage determination unit 720 and the zero point count up correction unit 730 may be incorporated in the R / D 710.

  During operation, an excitation voltage is applied to the excitation coil of the rotation angle sensor 100 by an AC power source (not shown). For example, the AC power source applies an AC input voltage of, for example, 4 V to both ends of the exciting coil. When the excitation coil is excited and a magnetic force is generated, the detection coil generates electricity. As described above, the outer contour line of the rotor 104 is defined not by a constant diameter but by a periodically changing diameter. Therefore, when the rotor 104 rotates, the radial distance between the teeth of the rotor 104 and the stator 106 changes periodically, and accordingly, the magnetic flux resistance changes and is induced in the detection coil around the teeth of the stator 106. The output current (output voltage) changes. By utilizing such a phenomenon, the rotation angle of the rotor 104 and thus the rotation angle θ of the rotating body 150 are magnetically detected.

  An R / D 710 is connected to the rotation angle sensor 100. Output signals from the detection coil of the coil 108 (sin phase output voltage and cos phase output voltage) are input to the R / D 710.

The R / D 710 outputs a digital signal representing the rotation angle θ of the rotor 104 based on the sin-phase output voltage and the cos-phase output voltage. The rotation angle θ of the rotor is derived using, for example, the relationship of the following equation.
θ = 1 / N · tan-1 (E _SIN-GND / E _COS-GND )
Here, E _COS-GND represents a cos-phase output voltage, and E _SIN-GND represents a sin-phase output voltage.

  FIG. 12A shows a normal sin phase output waveform and a cos phase output waveform, and a sin phase peak waveform (envelope waveform) and a cos phase peak waveform. FIG. 12B shows a normal relative angle output waveform.

  FIG. 13 shows the same output waveform of the rotation angle sensor 100 including the rotor 104 divided into two as described above. FIG. 14 shows another output waveform of the rotation angle sensor 100 including the rotor 104 divided into two as described above.

  In a normal configuration, that is, in a configuration in which the rotor is not divided, there is no distortion in the output waveform of the sin phase and the output waveform of the cos phase. In the case of the rotation angle sensor 100 including the rotor 104 divided in two as described above. Due to the joint of the divided rotor 104, distortion occurs in the output waveform.

  In the example shown in FIG. 13, the notch 107 (see FIG. 5A) at the joint of the divided rotor 104 is set at a position corresponding to a mechanical angle of about 180 degrees. As indicated by R1, a sharp gap increases between the rotor 104 and the stator 106 in the vicinity of a mechanical angle of 180 degrees, and distortion occurs in the output waveform of the sin phase and the output waveform of the cos phase. Accordingly, as indicated by R2 in FIG. 13B, distortion also occurs in the output waveform of the relative angle in the vicinity of the mechanical angle of 180 degrees.

  Similarly, in the example shown in FIG. 14, the notch 107 (see FIG. 5A) at the joint of the divided rotor 104 is set at a position corresponding to a mechanical angle of about 150 degrees. As indicated by S1 in (A), a sudden gap increase occurs between the rotor 104 and the stator 106 near a mechanical angle of 150 degrees, and distortion occurs in the sin phase output waveform and the cos phase output waveform. To do. Accordingly, as indicated by S2 in FIG. 14B, distortion also occurs in the output waveform of the relative angle near the mechanical angle of 150 degrees.

  The rotation angle detection apparatus 800 performs phase matching using such waveform distortion (characteristics of the output signal). Hereinafter, this configuration will be specifically described.

  FIG. 15 is a flowchart showing a main processing flow realized by the signal processing unit 700. FIG. 16 is an explanatory diagram of the zero-point passage determination process. Hereinafter, as a premise, a description will be given of a case where a point where the above-described distortion occurs is a “zero point” of a relative angle. The processing routine shown in FIG. 15 is repeatedly executed at a cycle corresponding to the rotation angle calculation cycle (resolution).

In step 100, the zero-point passage determination unit 720 of the signal processing unit 700 is based on the change amount θe / θm of the electrical angle with respect to the change of the mechanical angle in the current cycle, that is, the gradient of the relative angle waveform shown in FIG. Based on θe / θm, it is determined whether or not zero point passage has occurred. Here, the determination conditions may be as follows.
Xa <θe / θm <Xb or -Xb <θe / θm <-Xa
Here, as conceptually shown in FIG. 16, Xa corresponds to the amount of change during normal time, that is, the amount of change when not passing through the zero point and the sign change point, and Xb is the cos phase and sin phase. Corresponds to the amount of change when the sign changes.

  When the zero point passage occurs, although it is smaller than Xb, a relatively large change amount occurs due to the above-described distortion. The above conditions are set by paying attention to such a phenomenon, and the zero point passage can be determined with high accuracy.

  When the zero point passage determination unit 720 determines that the zero point passage has occurred, the zero point count up correction processing by the zero point count up correction unit 730 of the signal processing unit 700 is executed. On the other hand, when it is determined that the zero point passage has not occurred, the zero point passage determination unit 720 repeats the determination in step 100 using the relative angle information input in the next cycle.

  FIG. 17 is a flowchart showing the flow of zero point count-up correction processing realized by the zero point count-up correction unit 730. FIG. 18 is an explanatory diagram of the zero-point count-up correction process and shows the state of the count-up value under each situation. As shown in FIG. 18A, the count-up value changes every 180 degrees of electrical angle. For example, the count-up value is increased or decreased when the sign changes between the cos phase and the sin phase. In the example shown in FIG. 18, there is distortion in the waveform at the position of the count-up value “4”. That is, there is a discrimination point for passing the zero point at the position of the count-up value “4”.

  In step 112, the zero-point count-up correction unit 730 compares the zero-point count-up value Na at the current zero-point passage with the reference zero-point count-up value Nb (Nb = 4 in this example). Process. The zero count-up value is a count-up value when the zero point passage is determined.

  As a result of the comparison processing, when the zero point count-up value Na and the reference zero point count-up value Nb are equal (YES in step 114), the zero point count-up value Na is held as it is. On the other hand, when the zero point count-up value Na and the reference zero point count-up value Nb are different (NO in step 114), the zero point count-up value Na is changed to the reference zero point count-up value Nb and stored (step). 118).

  Here, it is assumed that the ignition switch is turned off in the state shown in FIG. 18A, that is, the current count-up value is “7”. When the steering wheel is not operated with the ignition switch turned off, the stored value “7” of the count-up value is valid and can be used as it is when the next ignition switch is turned on. However, it is assumed here that the steering wheel is operated (returned by about one cycle in electrical angle) with the ignition switch turned off, and the actual count-up value becomes “5”. In this case, when the next ignition switch is turned on, the count-up value is incremented or decremented assuming that the stored value of the count-up value is “7”. During the subsequent driving or the like, when the steering wheel is operated and the zero point is passed, the zero point count-up correction process shown in FIG. 17 is executed. Here, as shown in FIG. 18C, it is assumed that the steering wheel is returned by an electrical angle by about a half cycle. At this time, the zero point count-up value Na when passing through the zero point this time is “6”. That is, an error occurs as much as the steering wheel is operated with the ignition switch off. At this time, the zero point count-up value Na is corrected from “6” to the correct count-up value “4” by the zero-point count-up correction process (see step 116) shown in FIG.

  As described above, according to the present embodiment, for example, when the steering wheel is operated with the ignition switch turned off, or when the count-up value is lost due to temporary interruption of the power source, the divided rotor 104 is adjusted. Phase matching (correction of the count-up value) can be performed using the characteristics of the output waveform generated due to the eyes. Thereby, rotation angle information can always be obtained with high accuracy.

  In the present embodiment, as described above, the notch 107 is set on one side of the joint of the rotor 104, and one point that is generated only once in one cycle of the mechanical angle due to the notch 107 is set. Phase matching is performed using feature points. That is, a relatively small strain generated on the other side of the joint of the rotor 104 is ignored, and a relatively large strain caused by the notch 107 is used to use one feature point in one cycle of the mechanical angle. Phase matching. However, it is also possible to perform phase alignment using two feature points generated on both sides of the joint of the rotor 104. In this case, if the above-described division line T is set so that the characteristics of the output waveform caused by the joints of the divided rotors 104 are generated at phases of different electrical angles, it is possible to distinguish between the respective characteristic points. In this case, an opportunity for phase alignment can be obtained twice in one cycle of the mechanical angle.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, one rotation angle sensor (resolver) is used. However, two or more rotation angle sensors can be similarly divided and configured. For example, as shown in FIG. 19, when two systems of rotation angle sensors are provided close to each other in order to ensure redundancy, the two rotation angle sensors can be configured to be divided (integrally) in the radial direction. It is.

  In the above-described embodiment, the rotation angle is detected as a relative angle. However, the present invention is not limited to this, and a second resolver having a different shaft multiple angle is set so that the rotation angle is an absolute angle. It is also possible to detect with.

  In the above-described embodiment, the number of divisions is two, but three or more divisions are possible.

  In the above-described embodiment, the notch 107 whose diameter rapidly decreases is set at the joint of the rotor 104 to make the distortion generated in the output waveform more obvious. You may set the convex part which increases rapidly.

  In the above-described embodiment, the configuration is one-phase input / 2-phase output. However, two-phase input / 1-phase output may be used, and the phase mode is arbitrary.

  In addition, the rotation angle sensor (resolver), as in the above-described embodiment, winds windings (excitation coil and detection coil) around a convex stator (teeth) that faces the rotor in the radial direction. The present invention is not limited to the type that performs angle detection using the change in magnetoresistance. For example, a rotation angle sensor is a type in which a winding (excitation coil and detection coil) is wound around a convex stator core that is axially opposed to a rotor, and angle detection is performed using changes in the axial magnetic resistance. It may be. In this type, when the rotor rotates, the shielding width between the outer peripheral portion of the rotor and the upper surface of the stator core changes, and the width that shields the magnetic flux passing through the stator core changes periodically. The current (output voltage) induced in the detection coil around the core changes. In this case, the excitation coil and the detection coil do not necessarily need to be of a winding type, and can be thinned using a coil on a film (a coil printed on a substrate).

  As described above, the present invention can be used in any device that needs to detect the rotation angle of a rotating body, including a rotation angle detection device that detects the rotation angle of a steering shaft in a power steering device.

It is a 2nd page figure which shows one Example of a rotation angle sensor. It is sectional drawing at the time of cut | disconnecting along line AA of FIG. It is a figure which shows the open state of the rotation angle sensor 100 of a present Example. FIG. 4 is an enlarged view of a portion B in FIG. 3 and is a diagram for illustrating a connection mode of coils. FIG. 4 is a diagram illustrating an example of a shape of a rotor 104. It is sectional drawing at the time of cut | disconnecting along the line DD of FIG. 5 (A). It is sectional drawing at the time of cut | disconnecting along the line DD of FIG. 5 (B). It is a 2nd page figure showing rotation angle sensor 400 by other examples. It is a figure which shows the rotation angle sensor 400 of an open state. It is explanatory drawing of the assembly | attachment property with respect to the stepped shaft as the rotary body 150. FIG. It is a system block diagram which shows one Example of the rotation angle detection apparatus 800 by this invention. It is a figure which shows a normal waveform. It is a figure which shows the same output waveform of the rotation angle sensor 100 provided with the rotor 104 divided into two. It is a figure which shows the other output waveform of the rotation angle sensor 100 provided with the rotor 104 divided into two. 5 is a flowchart showing a main processing flow realized by a signal processing unit 700. It is explanatory drawing of 0 point passage determination processing. 10 is a flowchart showing a flow of zero point count-up correction processing realized by a zero point count-up correction unit 730. It is explanatory drawing of a 0 point count-up correction process. It is a figure which shows the installation state of the rotation angle sensor by another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Rotation angle sensor 102 Casing 104 Rotor 106 Stator 107 Notch 108 Coil 110,112 Bearing 122 Hinge part 130 Fastener 150 Rotating body 410 Claw 700 Signal processing part 710 R / D
720 0-point passage determination unit 730 0-point count up correction unit 800 rotation angle detection device

Claims (4)

A rotation angle detection device for detecting a rotation angle of a rotating body,
A rotation angle detection device comprising a rotation angle sensor having a main body divided into two in the radial direction. The rotation angle sensor includes a rotor that rotates together with the rotating body, a stator, an excitation coil, and a detection coil, and detects the rotation angle of the rotating body using magnetic flux resistance that periodically changes as the rotor rotates. The rotation angle detection device according to claim 1,
A signal processing unit that processes an output signal input from the detection coil and outputs rotation angle information of the rotating body,
The rotation angle detection device, wherein the signal processing unit generates rotation angle information of a rotating body using a feature of an output signal generated due to a split rotor joint. The diameter of the rotor is determined so as to change according to a substantially sine wave function in which the rotation angle of the rotor is a variable and the period is determined by the shaft angle multiplier,
The rotation according to claim 1 or 2, wherein the rotor is split such that two points of the output signal due to both sides of the split rotor seam appear at different phases in the sinusoidal function. Angle detection device.   The rotation angle detection device according to any one of claims 1 to 3, wherein the rotor is configured to change abruptly at a joint having a divided diameter.

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