JP4727284B2 - Multi-rotation absolute angle detection mechanism and detection method - Google Patents

Description

  The present invention relates to a multi-rotation absolute angle detection mechanism and a detection method for detecting an absolute steering angle of a steering.

  As this type of multi-rotation absolute angle detection mechanism, a reduction mechanism combining a worm and a worm wheel, or a reduction mechanism in which spur gears are arranged, and an encoder that detects an absolute angle within one rotation and a multi-rotation amount are detected. An output signal obtained from an encoder is synthesized by a signal processing circuit to detect a multi-rotation absolute angle (Patent Documents 1 and 2).

  A large-diameter gear is provided coaxially with the steering shaft and a small-diameter gear that meshes with the large-diameter gear is used to detect the steering angle of the steering. The rotation angle of the steering shaft is determined based on the output signal of the reference position sensor that detects the magnets arranged at a distance from each other and the output signal of the magnetic sensor that detects the magnetic force lines of the rotation angle detection magnet provided on the small-diameter gear. What has been sought is also proposed (Patent Document 3).

Furthermore, there has also been proposed a configuration in which the rotation angle of the output shaft of the planetary gear mechanism is detected by a sensor so as to detect the multi-rotation absolute angle of the object directly connected to the input shaft of the planetary gear mechanism. (Patent Document 4).
JP 2001-289671 A Japanese Patent Laid-Open No. 2004-45083 JP 2003-344209 A JP 2002-340545 A

  However, in the configuration disclosed in Patent Document 1 using a speed reduction mechanism in which a worm and a worm wheel are combined, the reduction ratio can be increased, but since the axes are orthogonal, the structure becomes complicated and the space for the mechanism also increases.

  Further, in the configuration disclosed in Patent Document 2 using a speed reduction mechanism in which spur gears are arranged, a space in the radial direction of the mechanism is increased for sensor installation. Moreover, since it has a some shaft, a bearing installation space is required and a structure becomes complicated.

  In the configuration disclosed in Patent Document 4 using a planetary gear mechanism, the number of gears increases, and how to support these gears (especially planetary gears) becomes an issue. Further, when trying to increase the reduction ratio, the radial space of the mechanism increases.

  In addition, the multi-rotation absolute angle detection mechanism using each reduction gear described above can detect only the number of rotations corresponding to the reduction ratio (for example, five rotations if the reduction ratio is 1/5).

  An object of the present invention is to provide a multi-rotation absolute angle detection mechanism that can be compactly configured and can detect a wide range of multi-turn absolute angles, and a detection method using the multi-turn absolute angle detection mechanism.

The multi-rotation absolute angle detection mechanism according to the present invention includes an eccentric ring fixed to a rotation shaft, an internal toothed member having inward teeth installed on a fixed member, and an outward tooth engaging with the internal toothed member. Thus, the externally toothed member that decelerates and rotates on the eccentric rotation center of the eccentric ring at a reduction ratio 1 / L (L: an arbitrary value of 1 or more), and the eccentric rotation center that is rotationally transmitted from the externally toothed member. A speed reduction mechanism comprising a speed reduction member that rotates at a speed reduction ratio of 1 / L on the rotary shaft at a speed equal to the rotation of the upper toothed member, and the speed reduction member has one sine wave per rotation or A detection part of a multi-rotation detection unit, which is a rotation detection means for outputting a sawtooth wave, is installed, the detection part of the multi-rotation detection unit is installed on a fixed member so as to face the detection part , and 1 described later this provided the detected portion for rotation detection, and for detecting one rotation detecting unit The features.
According to this configuration, a reduction mechanism having a high reduction ratio by an intermeshing planetary gear mechanism composed of an eccentric ring, an internally toothed member, and an externally toothed member, and a constant speed internal gear mechanism composed of an externally toothed member and a reduction member. Is configured. Therefore, it is possible to detect a wide range of multi-rotation absolute angles by detecting the absolute position of the deceleration member of the deceleration mechanism. Further, by using the inscribed mesh planetary gear mechanism and the constant speed internal gear mechanism as the speed reduction mechanism, a shaft-through multi-rotation absolute angle detection mechanism can be configured. For these reasons, a high reduction ratio can be obtained with a shaft-through type reduction mechanism, so that a wide range of multi-rotation absolute angles can be detected with a compact configuration.

In the present invention, the detected portion may be a magnetic encoder, and the detecting portion may be a sensor housing in which a Hall IC is incorporated. As a result, the multi-rotation detection unit can have a simple configuration.
The detected portion may be a resolver rotor, and the detection portion may be a resolver stator. If a resolver is used, highly accurate detection becomes possible.
The internal gear member may be an internal gear, and the external gear member may be a spur gear. In this case, the configuration is simple.

  In this invention, you may each provide the engaging part which contact | abuts mutually and limits the rotation range of the said deceleration member in the said deceleration member and a fixing member. By providing this engaging portion, the rotation of the speed reducing member can be limited to a range of one rotation in which the absolute angle can be detected by the multi-rotation detecting portion.

The present invention smell Te, as the first rotation part to be detected for detection and for detecting one rotation detection section, the upper Symbol rotary shaft, a sine wave or sawtooth of n mountain one revolution (n = 1, 2, 3 ...) A one-rotation detection detection unit that is a detection unit of the one-rotation detection unit that is a rotation detector to output is installed, and the detection unit of the one-rotation detection unit is opposed to the one-rotation detection detection unit. A detection unit for detecting one rotation is installed.
When the multi-rotation detection unit and the single-rotation detection unit are provided as described above, the rotational speed (integer value) of the rotation shaft is determined from the output signal of the multi-rotation detection unit, and the rotational speed and the output signal of the single-rotation detection unit. By using, multi-turn absolute angle detection with higher accuracy can be performed.
In addition, the multi-rotation detection unit is provided for the reduction mechanism composed of the intermeshing planetary gear mechanism and the constant-velocity internal gear mechanism as described above, and combines the single rotation detection unit coaxially with the multi-rotation detection unit. More accurate multi-turn absolute angle detection can be performed with a compact configuration.

When the one-rotation detection unit is provided, the detection target for one rotation detection may be a magnetic encoder, and the detection unit for one rotation detection may be a sensor housing in which a Hall IC is incorporated. This makes it possible to provide the one rotation detection unit with a simple configuration.
In addition, when a single-rotation detection unit is provided, the single-rotation detection detection unit and the multi-rotation detection detection unit are configured as magnetic encoders, and the single-rotation detection detection unit and the multi-rotation detection detection unit are incorporated with Hall ICs. The sensor housing in the one-rotation detection detection unit and the multi-rotation detection detection unit may be formed integrally with each other. As described above, the sensor housings in the single-rotation detection detection unit and the multi-rotation detection detection unit are formed integrally with each other, whereby the configuration of the detection unit can be made compact.
When a one-rotation detection unit is provided, the one-rotation detection detection unit may be a resolver rotor, and the one-rotation detection detection unit may be a resolver stator. If a resolver is used, accurate rotation detection can be performed.

  In the present invention, means for correcting a signal output from the multi-rotation detection unit or the single-rotation detection unit to an ideal waveform may be used. By using this correcting means, it is possible to detect the angle with high accuracy even if the output characteristics of the multi-rotation detection unit or the single-rotation detection unit are not a beautiful saw wave or sine wave. The correction means may be, for example, one that electrically corrects.

In the multi-turn absolute angle mechanism of the present invention, the multi-turn absolute angle detection mechanism may be used as a steering angle sensor for steering.
Since the steering angle sensor of the steering is required to detect an absolute angle of ± several rotations, the effect of being able to detect a wide range of multiple rotation absolute angles with the compact configuration of the present invention is effectively exhibited.

The multi-rotation absolute angle detection method of the present invention is a detection method using the multi-rotation absolute angle mechanism of the present invention, wherein the number of sine waves or sawtooth waves output by the rotation angle detection device of the one-rotation detection unit is n ( n = 1,2,3..., and the fractional part α of the L value of the reduction ratio 1 / L of the multi-rotation detector is
α ≠ β / n (0 ≦ β ≦ n−1, β: integer)
It is a method.
If the reduction ratio 1 / L of the reduction mechanism for multi-rotation detection is set to an appropriate value in accordance with the number n of sine waves or sawtooth waves output from the rotation angle detection device of the one-rotation detection unit, the motor rotates in the forward direction. Therefore, it is possible to detect the rotational speed up to twice the reduction ratio. For example, if the reduction ratio is 1/5, 10 rotations can be detected.
Decimal part α of the L value of the reduction ratio 1 / L,
α ≠ β / n (0 ≦ β ≦ n−1, β: integer)
Then, a wide range of multi-rotation absolute angle detection over ± L rotations becomes possible.
Since the rotation angle detection range is increased by determining whether the rotation direction is positive or negative, there is no need to increase the reduction ratio of the speed reduction mechanism itself, and a wide range of multi-rotation absolute angle detection is possible with a compact configuration.

Another multi-rotation absolute angle detection method according to the present invention is a detection method using the multi-rotation absolute angle mechanism of the present invention, wherein the reduction ratio 1 / L of the multi-rotation detection unit is a non-integer, and the range of rotation speeds to be detected ± r (r: integer), where the number of sine waves or sawtooth waves output by the rotation angle detection device of the one rotation detection unit is n (n = 1, 2, 3...), And the reduction ratio of the multi-rotation detection unit In this method, the L value of 1 / L is set to L = r + 1 / (2n).
When the L value of the reduction ratio 1 / L is selected as L = r + 1 / (2n), the phase difference between the positive rotation signal and the negative rotation signal in the one rotation detection unit becomes the maximum, and the multiple rotation detection unit Signals can be used to the maximum. Therefore, the rotation direction and the number of rotations can be easily discriminated. Therefore, even if there is play in the speed reduction mechanism or noise appears in the signal, the multi-rotation absolute angle detection can be performed with high accuracy.

Still another multi-rotation absolute angle detection method of the present invention is a detection method using the multi-rotation absolute angle detection mechanism of the present invention, and detects L of the reduction ratio 1 / L of the multi-rotation detection unit as a non-integer. The rotation speed range is ± r (r: integer), the number of sine waves or sawtooth waves output from the rotation angle detection device of one rotation detection unit is n (n = 1, 2, 3...), And a multi-rotation detection unit This is a method in which the decimal part of the L value of the reduction ratio 1 / L is a / n + 1 / (2n) (0 ≦ a <n, a: integer).
Thus, even when the decimal part of the L value of the reduction ratio 1 / L is a / n + 1 / (2n) (0 ≦ a <n, a: integer), The phase difference of the negative rotation signal is maximized, and the signal of the multi-rotation detector can be used to the maximum. Therefore, the rotation direction and the number of rotations can be easily discriminated. Therefore, even if there is play in the speed reduction mechanism or noise appears in the signal, the multi-rotation absolute angle detection can be performed with high accuracy.

The multi-rotation absolute angle detection mechanism according to the present invention includes an eccentric ring fixed to a rotation shaft, an internal toothed member having inward teeth installed on a fixed member, and an outward tooth engaging with the internal toothed member. Thus, the externally toothed member that decelerates and rotates on the eccentric rotation center of the eccentric ring at a reduction ratio 1 / L (L: an arbitrary value of 1 or more), and the eccentric rotation center that is rotationally transmitted from the externally toothed member. A speed reduction mechanism comprising a speed reduction member that rotates at a speed reduction ratio of 1 / L on the rotary shaft at a speed equal to the rotation of the upper toothed member, and the speed reduction member has one sine wave per rotation or The detection unit of the multi-rotation detection unit, which is a rotation detection means for outputting a sawtooth wave, is installed, and the detection unit of the multi-rotation detection unit is installed on the fixed member so as to face this detection unit. In addition, a wide range of multi-turn absolute angle detection is possible. It made.
Detected for one rotation detection, which becomes a detected portion of a one-rotation detection unit that is a rotation detector that outputs a sine wave or sawtooth wave of n peaks (n = 1, 2, 3. part set up, to face the detected portion for the one rotation detection, because the set up for detecting one rotation detecting unit is a detecting unit of the first rotation detecting unit, performs more accurate multiple rotation absolute angle detecting be able to.
The multi-rotation absolute angle detection method of the present invention is a detection method using the multi-rotation absolute angle detection mechanism of the present invention, in which the number of sine waves or sawtooth waves output from the rotation angle detection device of one rotation detection unit is calculated. n (n = 1, 2, 3...), and the fractional portion α of the L value of the reduction ratio 1 / L of the multi-rotation detection unit,
α ≠ β / n (0 ≦ β ≦ n−1, β: integer)
Therefore, it is possible to detect a wide range of multiple rotation absolute angles over ± L rotations.
Another multi-rotation absolute angle detection method according to the present invention is a detection method using the multi-rotation absolute angle detection mechanism according to the present invention, and is a rotation that detects a non-integer L of the reduction ratio 1 / L of the multi-rotation detection unit. The number range is ± r (r: integer), the number of sine waves or sawtooth waves output from the rotation angle detection device of one rotation detection unit is n (n = 1, 2, 3...), And the multi-rotation detection unit Since the L value of the reduction ratio 1 / L is L = r + 1 / (2n), the phase difference between the positive rotation signal and the negative rotation signal in the one rotation detection unit becomes the maximum, and the multiple rotation detection unit Signals can also be used to the maximum, and the direction of rotation and the number of rotations can be easily determined, and multi-turn absolute angle detection can be performed with high accuracy regardless of the play of the speed reduction mechanism and signal noise.
Still another multi-rotation absolute angle detection method of the present invention is a detection method using the multi-rotation absolute angle detection mechanism of the present invention, and detects L of the reduction ratio 1 / L of the multi-rotation detection unit as a non-integer. The range of rotation speed is ± r (r: integer), and the number of sine waves or sawtooth waves output from the rotation angle detector of one rotation detector is n (n = 1, 2, 3. Since the fractional part in the L value of the reduction ratio 1 / L of the part is a / n + 1 / (2n) (0 ≦ a <n, a: integer), also in this case, the positive rotation in the one rotation detection part The phase difference between the signal and the negative rotation signal is maximized, and the signal from the multi-rotation detector can be used to the maximum, making it easy to determine the direction and speed of rotation, regardless of play in the speed reduction mechanism or signal noise. Multi-rotation absolute angle detection can be performed with high accuracy.

An example of a proposal which is the basis of the present invention will be described with reference to FIGS. The multi-rotation absolute angle detection mechanism 1 is used, for example, as a steering angle sensor for steering, and includes a speed reduction mechanism 2 that converts the rotation of the rotary shaft 8 into a speed reduction rotation, and a speed reduction rotation converted by the speed reduction mechanism 2. And a multi-rotation detection unit 3 for detecting. The rotating shaft 8 is rotatably supported on the fixed member 9 by a bearing (not shown) or the like.

  The speed reduction mechanism 2 meshes with the eccentric ring 4 fixed to the rotating shaft 8, the internally toothed member 5 installed concentrically with the rotating shaft 8 on the inner periphery of the fixed member 9, and the internally toothed member 5. The member 6 with external teeth that rotates around the eccentric rotation center O ′ of the eccentric ring 4 and the speed reduction member 7. The speed reduction member 7 is rotatably provided on the outer periphery of the rotating shaft 8, and is transmitted from the external toothed member 6 to rotate at the same speed as the external toothed member 6.

A cylindrical rotor housing 10 is fixed to the outer periphery of the rotary shaft 8 by press-fitting or bonding, and the eccentric ring 4 is fixed to the outer periphery of the rotor housing 10 by press-fitting or bonding. The eccentric ring 4 has an outer peripheral surface that is eccentric with respect to the inner peripheral surface that is fitted to the rotor housing 10, and the eccentric rotation center O ′ that is the center of the outer peripheral circle is offset with respect to the axial center O of the rotary shaft 8. It becomes the position. As a result, the outer peripheral surface of the eccentric ring 4 rotates eccentrically when rotating together with the rotary shaft 8.
The externally toothed member 6 is formed of a spur gear having outward teeth, and rotates around the eccentric rotation center O ′ by being rotatably fitted to the outer periphery of the eccentric ring 4. Although not shown in FIG. 1, in order to make the external toothed member 6 rotatable, it is desirable to provide the external toothed member 6 on the eccentric ring 4 via a bearing. If a sliding bearing is used as a bearing in this case, the installation structure of the member 6 with the external teeth on the eccentric ring 4 can be made more compact.

  A cylindrical stator housing 11 is fixed to the inner periphery of the fixing member 9 by press-fitting or bonding, and the inner toothed member 5 is fixed to the inner periphery of the stator housing 11 by press-fitting or bonding. The internal toothed member 5 is composed of an internal gear having inward teeth. The stator housing 11 is fixed to the inner periphery of the fixing member 9 and the rotor housing 10 is fixed to the outer periphery of the rotating shaft 8. The stator housing 11 and the outer periphery of the rotating shaft 8 are fixed to the inner periphery of the fixing member 9 and the outer periphery of the rotating shaft 8. A step portion for positioning the rotor housing 10 in the axial direction may be provided and fixed with a bolt or the like.

When the outward teeth of the externally toothed member 6 mesh with the inwardly facing teeth of the internally toothed member 5, the externally toothed member 6 rotates about the eccentric rotation center O ′ as the rotational shaft 8 rotates. 8 in a direction opposite to the rotation direction of 8 at a predetermined reduction ratio 1 / L (L: arbitrary value of 1 or more). The relationship between the internally toothed member 5 and the externally toothed member 6 in this case constitutes an intermeshing planetary gear mechanism that is generally well known. If the number of teeth of the externally toothed member 6 is Z ₁ and the number of teeth of the internally toothed member 5 is Z ₂ , the reduction ratio is (Z ₂ −Z ₁ ) / Z ₁ . Here, the externally toothed member 6 and the internally toothed member 5 having a small difference in the number of teeth are engaged and decelerated, but if the teeth are engaged, the internally toothed member 5 and the externally toothed member 6 are used. Any tooth shape may be used.
On the side surface of the externally toothed member 6, a plurality of engagement pins 12 projecting in the axial direction are equally arranged at predetermined intervals in the circumferential direction.

  The speed reduction member 7 is an annular member that is rotatably fitted on the outer periphery of the rotor housing 10, and includes a cylindrical portion 7a that fits on the outer periphery of the rotor housing 10, and a flange that extends from one end of the cylindrical portion 7a to the outer diameter side. Part 7b. The speed reduction member 7 is disposed adjacent to the eccentric ring 4 so that the flange portion 7b faces the engaging pin 12 of the external toothed member 6 in the axial direction.

  On the side surface of the speed reduction member 7 facing the externally toothed member 6 of the flange portion 7b, as shown in FIG. Open and arranged. The guide recess 13 is formed in a circular hole having a diameter sufficiently larger than the shaft diameter of the engagement pin 12 so that the displacement of the engagement pin 12 rotating around the eccentric rotation center O ′ is allowed in the guide recess 13. ing. Thus, the engaging pin 12 of the externally toothed member 6 engages with the guide recess 13 of the speed reducing member 7, whereby the speed reducing member 7 rotates on the rotation shaft 8 at a speed equal to the rotation of the externally toothed member 6. . In this case, the relationship between the externally toothed member 6 and the speed reduction member 7 constitutes a generally known constant speed internal gear mechanism. In this mechanism, the engagement pin 12 may be provided in the speed reduction member 7 and the guide recess 13 may be provided in the externally toothed member 6. Although not shown in FIG. 1, it is desirable to provide the speed reduction member 7 on the rotor housing 10 via a bearing in order to make the speed reduction member 7 rotatable. If a sliding bearing is used as a bearing in this case, the installation structure of the speed reduction member 7 to the rotor housing 10 can be made more compact.

  Since the externally toothed member 6 rotates at a reduced speed around the eccentric rotation center O ′, it is difficult to directly detect this rotational angle. However, the rotation of the externally toothed member 6 causes the axis O of the rotating shaft 8 to rotate. Since it is transmitted to the speed reduction member 7 that rotates around, the speed reduction rotation of the externally toothed member 6 can be easily detected indirectly by detecting the rotation of the speed reduction member 7.

  The multi-rotation detection unit 3 is provided on the detected portion 14 provided on the outer periphery of the cylindrical portion 7a of the speed reduction member 7 and on the inner periphery of the stator housing 11 on the fixed member 9 side so as to face the detected portion 14. And the detected unit 15. In the multi-rotation detection unit 3, the detection unit 15 outputs a single sine wave or sawtooth wave while the deceleration member 7 makes one rotation. The multi-rotation detection unit 3 is configured using, for example, a sensor housing in which a magnetic encoder is disposed as the detected portion 14 and a Hall IC is disposed as the detection portion 15 with a 90 ° phase difference. Alternatively, for example, a resolver rotor is used as the detected portion 14, and a resolver stator is used as the detecting portion 15.

  As shown in FIG. 3, the rotation of the speed reduction member 7 is brought into contact with the outer periphery of the flange portion 7 b of the speed reduction member 7 and the inner periphery of the stator housing 11 opposed to the radial direction by the multi-rotation detection unit 3. If the pair of engaging portions 16 and 17 limited within the range of one rotation capable of detecting the absolute angle is provided, the rotation range can be limited.

  Next, the operation of the multi-rotation absolute angle detection mechanism 1 configured as described above will be described. When the rotating shaft 8 rotates, the externally toothed member 6 rotatably provided on the outer periphery of the eccentric ring 4 meshes with the internally toothed member 5, and the reduction ratio is 1 / L in the direction opposite to the rotating direction of the rotating shaft 8. Decelerate and rotate. The decelerated rotation is transmitted at a constant speed to a decelerating member 7 that is rotatably provided on the outer periphery of the rotor housing 10. The absolute angle within one rotation of the deceleration member 7 can be detected from the output waveform of the detection unit 15 of the multi-rotation detection unit 3. The rotation of the rotating shaft 8 is decelerated and rotated by the reduction mechanism 2 at a reduction ratio 1 / L and converted into the rotation of the reducing member 7, so that one rotation of the reducing member 7 corresponds to L rotation of the rotating shaft 8. Therefore, the absolute angle within L rotations of the rotary shaft 8 can be detected from the output waveform of the detection unit 15 of the multi-rotation detection unit 3.

  As described above, in the multi-rotation absolute angle detection mechanism 1, the internal mesh planetary gear mechanism including the eccentric ring 4, the internally toothed member 5, and the externally toothed member 6, the externally toothed member 6, and the reduction member 7. Since the reduction mechanism 2 having a high reduction ratio is configured with the constant speed internal gear mechanism, a compact shaft penetration type can be obtained, a high reduction ratio can be obtained, and a wide range of multi-rotation absolute angle detection can be performed.

FIG. 4 shows a first embodiment of the present invention. This multi-rotation absolute angle detection mechanism 1 </ b> A is provided with a one-rotation detection unit 18 that detects one rotation of the rotary shaft 8, in addition to the multi-rotation detection unit 3 in the proposed example of FIG. 1. The one-rotation detection unit 18 is provided on the outer periphery of the rotor housing 10 on the rotating shaft 8 side, and on the inner periphery of the stator housing 11 on the fixed member 9 side, facing the detected portion 19. And the detection unit 20. The one-rotation detection unit 18 outputs a sine wave or sawtooth wave of n peaks (n = 1, 2, 3,...) (That is, n is a natural number) while the rotation shaft 8 makes one rotation. The one-rotation detection unit 18 is configured using, for example, a sensor housing in which a magnetic encoder is used as the detection unit 19 and a Hall IC is arranged as a detection unit 20 with a 90 ° phase difference. Alternatively, for example, a resolver rotor is used as the detected portion 19 and a resolver stator is used as the detecting portion 20. FIG. 4 shows an example in which the detected portion 19 is a resolver rotor and the detecting portion 20 is a resolver stator. Other configurations are the same as those in the proposed example of FIG.

In the proposed example shown in FIG. 1, the detection unit 15 in the multi-rotation detection unit 3 outputs one sine wave or sawtooth wave while the speed reduction member 7 rotates once, that is, while the rotation shaft 8 rotates L. Therefore, high-precision absolute angle detection cannot be expected. On the other hand, in the multi-rotation absolute angle detection mechanism 1A of this embodiment, the multi-rotation detection unit 3 can determine the rotation speed of the rotation shaft 8, and the one rotation detection unit 18 can reduce the rotation absolute angle of the rotation shaft 8 to 1 /. Since detection can be performed at intervals of n rotations, highly accurate multi-rotation absolute angle detection can be performed.

  FIG. 5 shows an explanatory diagram of an example of a multi-rotation absolute angle detection method using the multi-rotation absolute angle detection mechanism 1A of the embodiment of FIG. In this multi-rotation absolute angle detection method, in the multi-rotation absolute angle detection mechanism 1A of FIG. 4, the one-rotation detection unit 18 is composed of a resolver with an output of 1X and detects one sawtooth wave S1 for one rotation of the rotation shaft 8. To do. The reduction ratio of the speed reduction mechanism 2 is 1/5. The multi-rotation detection unit 3 is also composed of a resolver having an output of 1X, and detects a single sawtooth wave S2 per rotation of the speed reduction member 7. That is, here, when the rotating shaft 8 rotates 5 times, the sawtooth wave S1 is detected five times from the one-rotation detecting unit 18, and the sawtooth wave S2 is detected once from the multi-rotation detecting unit 3. In this case, since the rotation speed of the rotary shaft 8 can be determined from the output signal S2 of the multi-rotation detection unit 3, the absolute angle within 5 rotations is accurately calculated using the rotation speed and the output signal S1 of the single rotation detection unit 18. can do.

  By the way, when L at the reduction ratio 1 / L of the speed reduction mechanism 2 is set to an integer such as L = 5 as in the multi-rotation absolute angle detection method shown in FIG. 5, L rotation (in one rotation direction) Only an absolute angle within (L rotation) can be detected. Therefore, in FIG. 6, the absolute angle within ± L rotation (L rotation in both positive and negative rotation directions) of the rotating shaft 8 can be detected using the multi-rotation absolute angle detection mechanism 1A of the embodiment of FIG. An example of a rotation absolute angle detection method is shown.

In this multi-rotation absolute angle detection method, in the multi-rotation absolute angle detection mechanism 1A of FIG. 4, the one-rotation detection unit 18 is composed of a resolver with an output of 1X and detects one sawtooth wave S1 for one rotation of the rotary shaft To do. The reduction ratio of the speed reduction mechanism 2 is 1 / 5.5. The multi-rotation detection unit 3 is also composed of a resolver having an output of 1X, and detects a single sawtooth wave S2 per rotation of the speed reduction member 7. With the reduction ratio of 1 / 5.5, when the rotary shaft 8 rotates 5 times, the sawtooth wave S1 of 5 times is detected from the one-rotation detecting unit 18, and the sawtooth wave of 5 / 5.5 times is detected from the multi-rotation detecting unit 3. S2 is detected. In this case, even if the output value S2 of the multi-rotation detection unit 3 is the same for the positive side rotation and the negative side rotation, the output value S1 of the single rotation detection unit 18 is different for the positive side rotation and the negative side rotation. Therefore, it is possible to determine whether the rotation is positive or negative.
Generally, when the number of peaks output from the one-rotation detection unit 18 is n (natural number), the decimal fraction α of L of the reduction ratio 1 / L of the multi-rotation detection unit 3 is
α ≠ β / n (0 ≦ β ≦ n−1, β: integer)
And it is sufficient. α is calculated in the range of 0 ≦ α <1.
In particular, in the case of this embodiment in which a single sawtooth wave S1 is output from the one-rotation detection unit 18 to one rotation of the rotary shaft 8, when the reduction ratio is set to 1 / 5.5, the output value of the one-rotation detection unit 18 (half of the supply voltage V _c) values and the difference between the value of the negative side rotation becomes maximum at the positive side rotation of S1, it is possible to perform the negative decision easily.

In general, the value of L (L: non-integer) in the reduction ratio 1 / L of the reduction mechanism 2 in accordance with the number n of the sawtooth waves S1 output from the one-rotation detection unit 18 is expressed by the following equation: If set, when detecting ± r rotation (r: arbitrary number) of the rotary shaft 8, the difference between the value of the positive rotation and the value of the negative rotation of the output value S1 of the one rotation detector 18 is the largest. Thus, the positive / negative determination can be easily performed.
L = r + 1 / (2n)

Of course, the value of L in the reduction ratio 1 / L may be set to a value larger than the actually detected rotation speed, and only the decimal part of the value of L may be adjusted to the value of 1 / (2n). Further, the decimal part of the value of L may be a / n + 1 / (2n) (0 ≦ a <n, a: integer). If the detected rotational speed r is not an integer, the speed reduction ratio 1 / L may be selected so that the conditions described so far are satisfied and L ≧ r.
As described above, when only the decimal part of the L value in the reduction ratio 1 / L is adjusted to the value of 1 / (2n), or when the decimal part of the L value is a / n + 1 / (2n), one rotation is detected. The phase difference between the positive side rotation signal and the negative side rotation signal in the unit 18 is maximized, and the signal of the multi-rotation detection unit can be used to the maximum. Therefore, the rotation direction and the number of rotations can be easily discriminated. Therefore, even if there is play in the speed reduction mechanism or noise appears in the signal, the multi-rotation absolute angle detection can be performed with high accuracy.

  If such a method is used, the accuracy of the final absolute angle of multiple rotations is equivalent to the accuracy of the single rotation detection unit 18. For example, when a resolver is used for the one-rotation detection unit 18, it is generally said that the angle calculation accuracy is improved as the number of peaks n of the output waveform S1 increases. If the number of peaks n of the output waveform S1 of the one rotation detection unit 18 is 1 <n, the output waveform S1 of the one rotation detection unit 18 corresponds to the number of peaks other than determining the positive and negative rotation numbers. Therefore, the accuracy of the multi-rotation detector 3 is also required.

In the above description, the case where the one-rotation detection unit 18 that outputs a sawtooth wave detection signal (for example, a resolver) has been described, but other examples include, for example, the detection unit of the one-rotation detection unit 18. 20, two Hall ICs arranged with a phase difference of 90 degrees are used to detect sine wave signals a and b having a phase difference of 90 degrees, which makes one cycle per rotation (a: sine wave, b: cosine wave). ), An absolute angle of one rotation may be calculated from a / b and quadrant determination of each output, with half value V _c / 2 of power supply voltage V _c being 0.

  In the detection method described above, a signal output from the multiple rotation detection unit 3 or the single rotation detection unit 18 may be electrically corrected with a correction table. In this correction, when the output waveform is broken due to the output characteristics of the multi-rotation detection unit 3 or the single-rotation detection unit 18, the correction table has data for correcting the sawtooth wave or sine wave in an ideal shape. It is a process to correct. In this case, the absolute angle detection accuracy can be further improved.

  FIG. 5 shows still another embodiment of the present invention. This multi-rotation absolute angle detection mechanism 1A includes, in the embodiment of FIG. 4, a one-rotation detection unit 18, a detection unit 19 including a magnetic encoder, and a detection unit including a sensor housing in which Hall ICs are arranged with a 90 ° phase difference. 20. Here, the multi-rotation detection unit 3 is also composed of a detection unit 14 made of a magnetic encoder and a detection unit 15 made of a sensor housing in which Hall ICs are arranged with a 90 ° phase difference. The rotor housing 10 and the stator housing 11 are separated on the multi-rotation detection unit 3 side and the one-rotation detection unit 18 side. That is, since the rotor housing 10a and the stator housing 11a are provided on the multi-rotation detection unit 3 side, and the rotor housing 10b and the stator housing 11b are provided on the one-rotation detection unit 18 side, the multi-rotation detection unit 3 and the single rotation detection unit 18 are provided. Can be installed separately, increasing design freedom. Other configurations are the same as those of the embodiment of FIG.

  When the sensor housing in which the Hall ICs are arranged with a 90 ° phase difference is used for the multi-rotation detection unit 3 and the single-rotation detection unit 18 in the embodiment of FIGS. The sensor housings serving as both the detection units 15 and 20 may be formed integrally with each other, whereby both detection units 15 and 20 can be configured compactly.

  In each of the above-described embodiments, the case where each component is provided in the rotor housing 10 and the stator housing 11 fixed to the rotating shaft 8 and the fixing member 9 such as the housing is shown. By changing the shape of the member 9, each component may be provided directly on the rotary shaft 8 or the fixed member 9.

It is sectional drawing of the multi-rotation absolute angle detection mechanism based on the proposal example used as the foundation of this invention. It is II-II arrow sectional drawing in FIG. It is a side view of the rotation range limitation mechanism in the multi-rotation absolute angle detection mechanism. It is sectional drawing of the multi-rotation absolute angle detection mechanism which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows an example of the multi-rotation absolute angle detection method using the same multi-rotation absolute angle detection mechanism. It is explanatory drawing which shows another of the multi-rotation absolute angle detection method using the same multi-rotation absolute angle detection mechanism. It is sectional drawing of the multiple rotation absolute angle detection mechanism which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A ... Multi-rotation absolute angle detection mechanism 2 ... Deceleration mechanism 3 ... Multi-rotation detection part 4 ... Eccentric ring 5 ... Internal toothed member 6 ... External toothed member 7 ... Deceleration member 8 ... Rotating shaft 9 ... Fixed member 14 ... Detected part 15 of the multi-rotation detection part ... Detection part 16, 17 of the multi-rotation detection part ... Engagement part 18 ... One-rotation detection part 19 ... Detected part 20 of the one-rotation detection part ... Detection part O of the one-rotation detection part ... Rotation center of rotation axis O '... Eccentric rotation center of eccentric ring

Claims (13)

An eccentric ring fixed to the rotating shaft, an internal toothed member installed on the fixed member and having inward teeth, and an outward tooth and meshing with the internal toothed member, the eccentric rotation center of the eccentric ring The externally toothed member that decelerates and rotates at a reduction ratio 1 / L (L: any value greater than or equal to 1), and the speed equal to the rotation of the externally toothed member transmitted from the externally toothed member and rotated on the eccentric rotation center. in example Bei a reduction mechanism composed on the rotary shaft and a deceleration member at a reduced speed by the speed reduction ratio 1 / L,
Detected for one rotation detection, which becomes a detected portion of a one-rotation detection unit that is a rotation detector that outputs a sine wave or sawtooth wave of n peaks (n = 1, 2, 3. A one-rotation detection detection unit that is a detection unit of the one-rotation detection unit, opposite to the one-rotation detection detection unit,
Installed on Symbol detected portion of the multiple rotation detection unit that is a rotation detecting means for outputting a sine wave or sawtooth wave of one peak in one rotation deceleration member, the multiple rotation detection unit so as to be opposed to the detected part A multi-rotation absolute angle detection mechanism characterized in that the detection part is installed on a fixed member.
Multi-turn absolute angle detection mechanism. Te claim 1 smell, the multiple rotation detection unit on Symbol detected part is a magnetic encoder, the multiple rotation detection unit multiple rotation absolute angle detecting mechanism on the Symbol detector was a sensor housing which is integrated with Hall IC . Claim Te 1 smell, the multiple rotation detection unit upper Symbol detected portion resolver row data of the multiple rotation detection section of the upper Symbol multiple rotation absolute detection unit and a resolver stator angle detection mechanism.   The multi-rotation absolute angle detection mechanism according to any one of claims 1 to 3, wherein the internal gear member is an internal gear, and the external gear member is a spur gear.   5. The multi-rotation absolute angle detection mechanism according to claim 1, wherein the reduction member and the fixed member are provided with engaging portions that contact each other to limit a rotation range of the reduction member. 6. 6. The multi-rotation absolute angle detection mechanism according to claim 1, wherein the detection portion for detecting one rotation is a magnetic encoder, and the detection portion for detecting one rotation is a sensor housing in which a Hall IC is incorporated. . In any one of claims 1 to 5, the one rotation detection part to be detected and the multiple rotation detection part to be detected by the magnetic encoder, the one rotation detection detector and a multiple rotation detection detector A multi-rotation absolute angle detection mechanism in which a sensor housing in which a Hall IC is incorporated and the sensor housings in the one-rotation detection detection unit and the multi-rotation detection detection unit are formed integrally with each other. 6. The multi-rotation absolute angle detection mechanism according to claim 1, wherein the detection portion for one rotation detection is a rotor of a resolver, and the detection portion for one rotation detection is a stator of a resolver. 9. The multi-rotation absolute angle detection mechanism according to claim 1, further comprising means for correcting the signal output from the multi-rotation detection unit or the single rotation detection unit into an ideal waveform. 9. The multi-rotation absolute angle detection mechanism according to claim 1, wherein the multi-rotation absolute angle detection mechanism is used as a steering angle sensor for steering. 6. A detection method using the multi-rotation absolute angle detection mechanism according to claim 1, wherein the number of sine waves or sawtooth waves output from the rotation angle detection device of one rotation detection unit And n (n = 1, 2, 3...), And the fractional portion α of the L value of the reduction ratio 1 / L of the multi-rotation detector is
α ≠ β / n (0 ≦ β ≦ n−1, β: integer)
Multi-rotation absolute angle detection method. A detection method using the multi-rotation absolute angle detection mechanism according to any one of claims 1 to 5, wherein L is a non-integer number for detecting L of the reduction ratio 1 / L of the multi-rotation detection unit. Is the range of ± r (r: integer), the number of sine waves or sawtooth waves output from the rotation angle detection device of one rotation detection unit is n (n = 1, 2, 3...) A multi-rotation absolute angle detection method in which the value of L of the reduction ratio 1 / L is L = r + 1 / (2n). A detection method using the multi-rotation absolute angle detection mechanism according to any one of claims 1 to 5, wherein L is a non-integer number for detecting L of the reduction ratio 1 / L of the multi-rotation detection unit. Is the range of ± r (r: integer), the number of sine waves or sawtooth waves output from the rotation angle detection device of one rotation detection unit is n (n = 1, 2, 3...) A multi-rotation absolute angle detection method in which the decimal part of the L value of the reduction ratio 1 / L is a / n + 1 / (2n) (0 ≦ a <n, a: integer).

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