JP2020187025A - Rotation angle detector - Google Patents

Abstract

To configure a device which, by using a plurality of magnetic sensors capable of canceling magnetic noise, can detect a larger angle, and which hardly becomes unable to detect.SOLUTION: A permanent magnet M has four or more of divided magnetic pole faces into which a plane perpendicular to the axial core P is divided by a plurality of parallel virtual straight lines. The magnetic sensor MS has a function to cancel a disturbance magnetic field and is constituted so as to detect the rotation angle of the magnetic sensor MS on the basis of the magnetic flux of the permanent magnet M. A plurality of magnetic sensors MS are arranged on the same plane, and the permanent magnet M has such a positional relationship that the parallel directions of four or more of magnetic poles and the arrangement directions of the plurality of magnetic sensors MS can be parallel in a range in which the permanent magnet M rotates relatively to the magnetic sensors MS.SELECTED DRAWING: Figure 6

Description

The present invention relates to a rotation angle detecting device that detects a rotation angle by a permanent magnet and a magnetic sensor that detects the magnetic flux of the permanent magnet.

As a rotation angle detection device having the above configuration, Patent Document 1 describes a permanent magnet (magnet in the document) in which an N pole and an S pole are arranged at the end of a rotating body, and a permanent magnet at a position facing the permanent magnet. A configuration is described in which the two giant magnetoresistive elements are provided and the directions of the magnetic flux acting on the two giant magnetoresistive elements are output as a sine wave signal and a cosine wave signal.

In Patent Document 1, two giant magnetoresistive sensors are configured to detect the directions of magnetic fluxes of permanent magnets at angles different from each other by 90 ° and output them as a two-phase signal of a sine wave signal and a chord wave signal. , It is possible to detect the rotation angle from the two-phase signal.

Further, Patent Document 2 discloses a rotating magnetic field sensor in which a first applied magnetic field and a second applied magnetic field are formed by providing a pair of magnets on the rotating shaft to generate a magnetic field. A configuration is described in which a first detection unit that detects a first applied magnetic field and a second detection unit that detects a second applied magnetic field are arranged at positions sandwiched between the pair of magnets.

In Patent Document 2, the first detection unit has a first detection circuit and a second detection circuit that output detection signals having different phases. Further, the second detection unit has a third detection circuit and a fourth detection circuit that output detection signals having different phases. In this configuration, when a noise magnetic field other than the rotating magnetic field acts from the outside, the noise can be removed by an arithmetic expression based on the signals from the four detection circuits.

Further, although it is not a rotation angle detection device, Patent Document 3 describes a magnetic sensor in which a plurality of Hall elements are used to form a magnetic sensor, which enables cancellation of unnecessary magnetic flux components acting on the magnetic sensor. Is disclosed.

Japanese Unexamined Patent Publication No. 2014-163876 Japanese Unexamined Patent Publication No. 2012-37466 WO2007 / 116823 (paragraph number [0041] Fig. 9)

For example, considering that a rotation angle detection device is used to acquire the amount of depression of the brake pedal in a vehicle such as an automobile, it is desirable that the angle that can be detected by the rotation angle detection device is larger.

Further, in order to enable reliable detection of magnetic flux, a single permanent magnet and a plurality of magnetic sensors for detecting the relative rotation angle of the permanent magnets are used, for example, even if one magnetic sensor fails. It is also conceivable to use a signal detected by another magnetic sensor.

Since the magnetic sensor described in Patent Document 3 takes the difference between the signals from the pair of Hall elements, for example, the magnetic flux acting on one of the pair of Hall elements arranged in the XX direction. The direction of the magnetic flux acting on the other Hall element must be opposite to the direction of. Similarly, it is necessary that the magnetic flux acts in the opposite direction on the pair of Hall elements arranged in the YY direction.

In particular, since the magnetic sensor having this configuration takes the difference between the voltages of the two Hall elements, for example, when magnetic noise (magnetic flux) acts on the pair of Hall elements in one direction from the outside, the difference is taken by the calculation. , Magnetic noise cancellation is realized.

For this reason, there is a need for a device that can detect a larger angle by using a plurality of magnetic sensors capable of canceling magnetic noise and is less likely to fall into undetectable state.

The characteristic configuration of the rotation angle detection device according to the present invention is that a permanent magnet and a plurality of magnetic sensors arranged opposite to the permanent magnet and detecting the magnetic flux of the permanent magnet are provided so as to be relatively rotatable around the axis. The permanent magnet has a magnetic pole surface in which a plane orthogonal to the axis is divided into four or more poles by a plurality of virtual straight lines parallel to the axis, and the magnetic sensor has a function of canceling a disturbance magnetic field. The permanent magnets are configured to calculate the relative rotation angle with respect to the permanent magnets based on the magnetic flux of the permanent magnets, and a plurality of the magnetic sensors are arranged in parallel on the same plane. In the range of rotation relative to the magnetic sensor, the parallel direction of the magnetic poles having four or more poles and the arrangement direction of the plurality of magnetic sensors can be parallel.

According to this characteristic configuration, the permanent magnet has a magnetic pole surface divided into four or more poles, and when the permanent magnet and the plurality of magnetic sensors rotate relative to each other, the parallel direction of the four or more poles and the plurality of magnetic poles It is configured so that the arrangement direction of the magnetic sensor can be parallel to the above. From this configuration, when the permanent magnet and the plurality of magnetic sensors rotate relative to each other, the relative rotation angles in the form in which one N pole and one S pole correspond to one magnetic sensor. Detection is possible. Further, since the magnetic sensor has a function of canceling the disturbance magnetic field as described in Patent Document 3, erroneous detection is not caused even when the disturbance magnetic field acts from the outside. Further, according to this configuration, when the magnetic sensors are normal, the calculated values of the rotation angles are all the same, so when the calculated values of the rotation angles are different, it is detected that one of the magnetic sensors has failed. be able to. Even in such a case, since a plurality of magnetic sensors are used, it is still possible to detect the correct rotation angle.
Therefore, by using a plurality of magnetic sensors capable of canceling magnetic noise, it is possible to detect a larger angle, and a device that is unlikely to fall into undetectable is configured.

As another configuration, the magnetic sensor has a pair of magnetic electric conversion elements arranged along a first direction of a detection surface having a posture orthogonal to the axis, and a second direction different from the first direction on the detection surface. The magnetic sensor has another pair of magnetic electric conversion elements arranged along the above, and the magnetic sensor has a pair of the magnetic electric powers in a situation where the magnetic flux of the permanent magnet acts on each of the two pairs of the magnetic electric conversion elements. A magnetic detection signal is output from the difference between the voltage generated in response to the magnetic flux from one of the conversion elements and the voltage generated in response to the magnetic flux from the other magnetic conversion element, and the first direction. From the phase difference between the magnetic detection signal of the pair of magnetic electric conversion elements arranged along the second direction and the magnetic detection signal of the pair of magnetic electric conversion elements arranged along the second direction, the permanent magnet The permanent magnet is relative to the magnetic sensor in one of the pair of magnetic conversion elements, the magnetic conversion element and the other magnetic conversion element, so as to calculate the relative rotation angle of the magnetic flux. Magnetic fluxes of different polarities may always act in the rotating range.

According to this, the magnetic detection signal is acquired from the voltage difference of the pair of magnetic and electric conversion elements arranged along the first direction, and the magnetism is obtained by the voltage difference of the pair of magnetic and electric conversion elements arranged along the second direction. The detection signals can be acquired, and the rotation angle between the permanent magnet and the magnetic sensor can be calculated from the phase difference between these magnetic detection signals. Further, in the range in which the permanent magnet rotates relative to the magnetic sensor, one magnetron conversion element and the other magnetron conversion element are always provided with a complicated circuit because magnetic fluxes of different polarities act on them. The rotation angle can be reliably detected without performing any calculation.

It is sectional drawing of the rotation angle detection device. It is an exploded perspective view of the rotation angle detection device. It is a perspective view which shows the magnetic sensor of the detection board and a rotating member. It is sectional drawing which shows the magnetic flux acting on a magnetic sensor. It is a figure which shows the positional relationship between a permanent magnet in an initial posture, and a magnetic sensor. It is a figure which shows the positional relationship between a permanent magnet in an intermediate posture, and a magnetic sensor. It is a figure which shows the positional relationship between the permanent magnet in the limit posture, and a magnetic sensor. It is a figure which shows the positional relationship between the permanent magnet in the initial posture, and the magnetic sensor in another embodiment (a). It is a figure which shows the positional relationship between a permanent magnet in an intermediate posture, and a magnetic sensor in another embodiment (a).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration]
As shown in FIGS. 1 to 3, the rotation angle detecting device A includes a housing 10, a holder 20, a rotating member 30, and a cover 40.

In the rotation angle detection device A, the detection substrate 14 is housed in a sealing space T formed between the housing 10 and the holder 20 by connecting them. The rotating member 30 is arranged between the holder 20 and the cover 40, and by connecting the holder 20 and the cover 40, the rotating member 30 cannot move in the direction along the shaft core P and can rotate around the shaft core P. Be supported.

The holder 20 is provided with a partition wall portion 21 at a position where the sealing space T is closed. A single permanent magnet M is provided at one end of the rotating member 30 in the direction along the axis P, and the rotating member 30 is close to the partition wall 21 in order to bring the permanent magnet M close to the detection substrate 14. Have been placed. Further, the rotating member 30 is provided with an arm 35 that projects outward in the radial direction, and a torsion type return spring is provided in the spring accommodating space 33 on the side opposite to the end of the rotating member 30 where the permanent magnet M is arranged. 36 are housed.

The rotation angle detection device A is provided on the vehicle body to detect the operation angle of the pedal or the like when the accelerator pedal, the brake pedal or the like is depressed in a vehicle such as an automobile. Further, in the state of being mounted on the vehicle body, as shown in FIG. 1, the contact member 50 provided on the pedal or the like comes into contact with the contact portion 35a at the outer end of the arm 35 of the rotating member 30.

When the pedal is depressed and the contact member 50 is displaced in this state, the rotating member 30 is integrally rotated with the arm 35 about the axis P. This rotation operation is in a direction that opposes the urging force of the return spring 36, and the pedal depression angle is detected by detecting the rotation angle of the rotating member 30 with the magnetic sensor MS of the detection substrate 14. After that, when the pedal operation is released, the rotating member 30 returns to the initial posture Ra (see FIG. 5) by the urging force of the return spring 36. The details of the detection form will be described later.

[Housing, holder, rotating member, cover]
The housing 10, the holder 20, the rotating member 30, and the cover 40 are made of resin, and the arm 35 is made of metal. The housing 10 and the holder 20 are integrated by ultrasonic welding or an adhesive technique. Further, the holder 20 and the cover 40 are integrated by ultrasonic welding or an adhesive technique, and the rotating member 30 is sandwiched between the holder 20 and the cover 40 in the direction along the axis P. ..

The housing 10 has a concave portion that creates the sealing space T described above, and an outer wall portion 11 that surrounds the concave portion and a connector portion 12 are integrally formed. Further, a lead portion 13 made of a conductor is embedded between the concave portion and the connector portion 12. Of the lead portions 13, the detection side terminal 13a arranged inside the concave portion is electrically connected to the circuit of the detection board 14. On the other hand, among the lead portions 13, the output side terminal 13b arranged inside the connector portion 12 is exposed inside the connector portion 12.

The partition wall portion 21 of the holder 20 is in a form in which a part of the partition wall portion 21 of the holder 20 is fitted into the concave portion of the housing 10, and the concave portion is closed, and the rotation angle detection device A is assembled in a posture orthogonal to the axis P. Become. A connecting wall portion 22 is formed on the outer peripheral portion of the partition wall portion 21, and the outer wall portion 11 of the housing 10 is joined to the connecting wall portion 22 by a technique such as welding or adhesion. A circular smooth surface 21S is formed on the partition wall portion 21 facing the rotating member 30.

Further, an annular frame portion 23 centered on the axis P is formed in a region surrounding the smooth surface 21S, and a holding portion 24 joined to the cover 40 is formed outward from the annular frame portion 23. The end portion of the rotating member 30 on the side where the permanent magnet M is arranged is rotatably accommodated with respect to the annular frame portion 23. Further, the side wall portion 41 of the cover 40 is arranged so as to come into contact with the inner circumference of the holding portion 24, and these are integrated by welding or adhesion.

In particular, as shown in FIG. 2, a pair of flange portions 25 are formed in the holder 20 so as to project outward from the holding portion 24. The flange portion 25 has a bolt insertion hole, and when the rotation angle detection device A is mounted on the vehicle body, the flange portion 25 is fastened and fixed to the vehicle body by a bolt inserted through the bolt insertion hole.

As shown in FIGS. 1 to 3, the rotating member 30 has a disk shape centered on the shaft core P, a permanent magnet M is inserted in a portion facing the partition wall 21, and a spring is housed in a portion facing the cover 40. Space 33 is formed. A first support shaft 34 that engages with one end of the return spring 36 is formed in the spring accommodating space 33.

In the rotary member 30, a rotary support portion 31 that rotatably fits into the annular frame portion 23 is formed on one end side in a direction along the axis P, and faces the partition wall portion 21 of the rotary support portion 31. The contact surface 31S is formed at the end position in a posture orthogonal to the axis P.

Further, the rotating member 30 is formed with a large diameter portion 32 connected to the rotating support portion 31, and the base end portion of the arm 35 is inserted into the large diameter portion 32. The arm 35 has a contact portion 35a formed by bending an extended portion. Further, as shown in FIG. 1, the side wall portion 41 of the cover 40 is arranged so as to embrace the outer peripheral surface of the portion inserted into the base end portion of the arm 35.

Further, the cover 40 has a support recess 42 in which the end of the rotating member 30 on the side where the spring accommodating space 33 is formed is rotatably fitted. A second support shaft 43 is formed in which the other end of the return spring 36 engages with the support recess 42.

From such a configuration, in the rotation angle detection device A, the rotation support portion 31 of the rotation member 30 is fitted into the annular frame portion 23 of the holder 20, and the contact surface 31S of the rotation support portion 31 is formed on the partition wall portion 21. Contact. Further, the cover 40 comes into contact with the end of the rotating member 30 opposite to the permanent magnet M. Further, the inner circumference of the side wall portion 41 comes into contact with the outer circumference of the large diameter portion 32 of the rotating member 30. As a result, the rotating member 30 is rotatably supported around the shaft core P in a state where the displacement is restricted in the direction along the shaft core P.

When accommodating the return spring 36 in the spring accommodating space 33, one end of the return spring 36 is engaged with the first support shaft 34, and the other end of the return spring 36 is engaged with the second support shaft 43. Gain the urging force to return 30 to the initial posture Ra (see FIG. 5).

[Magnetic sensor]
As shown in FIGS. 3, 5 and 7, the permanent magnet M is rectangular as a whole, and a plurality of (three in this embodiment) virtual straight lines having a posture orthogonal to the axis P are formed. It has a divided magnetic pole surface, and N poles and S poles are alternately arranged in four divided regions of the magnetic pole surface. In the figure, the N pole is marked with an "N" and the S pole is marked with an "S". That is, the permanent magnet M has a predetermined surface of a single rectangular ferromagnet as a magnetic pole surface, is divided by virtual straight lines having a posture parallel to the magnetic pole surfaces, and N poles and S are divided into divided regions. It is magnetized so that the poles appear alternately. As the permanent magnet M, a ferrite magnet, an alnico magnet, a neodymium magnet, a plastic magnet, or the like can be used.

As shown in FIGS. 1 to 3, a plurality of (two in this embodiment) magnetic sensor MSs are formed on the surface of the detection substrate 14 facing the partition wall 21, and the detection surfaces of these magnetic sensor MSs are the magnetic pole surfaces. They are arranged on the same plane in a parallel posture. The two magnetic sensor MSs have a function of canceling a disturbance magnetic field, and in the two magnetic sensor MSs, the magnetic poles of the permanent magnets M are in a state where the permanent magnets M are in the intermediate posture Rb shown in FIG. It is arranged parallel to the parallel direction (vertical direction in the figure).

That is, as shown in FIG. 6, when the permanent magnet M is rotated about the axis P, the plurality of virtual straight lines that divide the magnetic poles and the direction in which the two magnetic sensor MSs are arranged can be perpendicular to each other. The positional relationship is set in.

As shown in FIGS. 5 to 7, the magnetic sensor MS includes a pair of first elements 1 (an example of a magnetron conversion element) arranged along a first direction (XX) of a detection surface, and the detection surface. A pair of second elements 2 (an example of a magnetron conversion element) arranged along a second direction (YY) in a direction (an example of a different direction) orthogonal to the first direction (XX). doing. In this magnetic sensor MS, a pair of first element 1 and a pair of second element 2 are formed as an integrated circuit formed by Hall elements with respect to the element support base material 3. A Hall element is an element that generates a voltage according to the magnitude of magnetic flux.

The distance between the pair of first elements 1 and the distance between the pair of second elements 2 are set to be equal. In this embodiment, the pair of elements arranged along the first direction (XX) is referred to as the first element 1, and the pair of elements arranged along the second direction (YY) is referred to as the first element 1. It is called the second element 2. The first element 1 and the second element 2 are Hall elements having the same configuration.

The detection board 14 is provided with an arithmetic circuit (not shown) that calculates the rotation angle of the permanent magnet M from the signals acquired by the two magnetic sensors MS. The arithmetic circuit may be provided on the element support base material 3. Further, the magnetic sensor MS uses an IC provided on the element support base material 3 with a circuit for detecting the rotation angle from the phase difference between the voltage generated from the pair of first elements 1 and the voltage generated from the pair of second elements 2. You may.

FIG. 4 shows an outline of the detection form of the magnetic flux by the pair of first elements 1 of the magnetic sensor MS. That is, the figure shows a configuration in which a pair of first elements 1 made of Hall elements are formed on the element supporting base material 3. When the magnetic flux is detected by the pair of first elements 1, the magnetic flux F from the north pole of the permanent magnet M penetrates the first element 1 on one side (left side in the figure) from top to bottom in the figure, and this magnet The magnetic flux F penetrates the other first element 1 (on the right side in the figure) from bottom to top and reaches the S pole.

Further, since the pair of the first element 1 and the pair of the second element 2 are formed by Hall elements, the magnetic flux of the magnet is tilted at an angle α with respect to the detection surface of the first element 1 as shown in FIG. When F penetrates, among the magnetic flux Bf penetrating the first element, a voltage having a value corresponding to the vertical component Bv perpendicular to the first element 1 is generated in the first element 1.

In this configuration, since the directions in which each element of the pair of first elements 1 is penetrated by the magnetic flux of the permanent magnet M are opposite, the voltage of one of the pair of first elements 1 and the voltage of the other first element Is a reverse potential, and by obtaining a magnetic detection signal that is the difference between these voltages, it is possible to detect the strength of the magnetic flux. Similarly, the pair of second elements 2 can detect the strength of the magnetic flux by obtaining the magnetic detection signal which is the difference in voltage.

In particular, in the detection mode shown in FIG. 4, for example, even when magnetic noise (magnetic flux) acts equally on one first element 1 and the other first element, one of the first elements is obtained by obtaining the above-mentioned difference. The magnetic noise acting on the element 1 and the other first element 1 is canceled, and as a result, the disturbance magnetic field is canceled (removed). The function of canceling the disturbance magnetic field in this way is also provided in the pair of second elements 2.

In the magnetic sensor MS having this configuration, as described above, the first direction (XX) and the second direction (YY) are in an orthogonal positional relationship, and as shown in FIGS. 5 to 7, the magnetic sensor MS On the other hand, when the permanent magnet M rotates about the axis P, the magnetic detection signal (change in magnetic flux) detected by the pair of first elements 1 is detected as a sine wave, and the pair The magnetic detection signal (change in magnetic flux) detected by the second element 2 is detected as a cosine wave.

Based on this, the rotation angle of the permanent magnet M with respect to the magnetic sensor MS is acquired by calculating the arctangent (arctan) based on the detection value of the first element 1 and the detection value of the second element 2 (taking a phase difference). Will be done. These operations are performed by an arithmetic circuit. As described above, as a magnetic sensor MS, a circuit that realizes a process for detecting a rotation angle from the voltage of a pair of first element 1 and a pair of second element 2. It is also possible to use an IC configured as an IC provided on the element support base material 3.

As described above, the two magnetic sensor MSs are arranged in parallel with the direction in which the magnetic poles of the permanent magnets M are parallel (vertical direction in the figure) with the permanent magnets M in the intermediate posture Rb shown in FIG. There is. In particular, when the permanent magnet M is in the intermediate posture Rb shown in FIG. 6, the two magnetic sensor MSs have virtual lines (not shown) connecting the second directions (YY) of the respective magnetic sensor MSs. , The north and south poles of the permanent magnet are orthogonal to each other in the parallel direction.

The widths of the north and south poles of the permanent magnet M are set to be equal to each other, and are set to about 1.5 times the distance between the pair of first elements 1 (equal to the distance between the pair of second elements 2). Further, the angle of the permanent magnet M from the initial posture Ra shown in FIG. 5 to the limit posture Rc shown in FIG. 7 is set to 90 °.

In the pair of second elements 2 of the two magnetic sensors MS, when the permanent magnet M rotates about the axis P from the initial posture Ra to the limit posture Rc, the opposing magnetic poles do not switch. That is, to explain based on the vertical direction shown in FIGS. 5 to 7, even if the permanent magnet M rotates, the upper second element 2 always faces the S pole, and the lower second element 2 faces the N pole. opposite.

On the other hand, when the permanent magnet M (rotating member 30) rotates about the axis P, the rotation angle faces the pair of first elements 1 in the vicinity of the angle of the intermediate posture Rb (about 45 °). The magnetic poles are configured to switch at the same time. That is, when the permanent magnet M rotates, the magnetic pole facing the first element 1 on the left side switches from the S pole to the N pole, and at the same time, the magnetic pole facing the first element 1 on the right side changes from the N pole to the S pole. Switch to. As described above, magnetic fluxes of different magnetic poles always act on the pair of first elements 1 and the pair of second elements except for the timing when the magnetic poles are switched by the permanent magnet M.

In this rotation angle detection device A, the rotation angle of the rotating member 30 is detected based on the detection signals of the two magnetic sensors MS, and when one of the MSs of the two magnetic sensors fails, the arithmetic circuit is the other. It is configured so that the rotation angle detected by the magnetic sensor MS of the above can be selected.

[Action and effect of the embodiment]
The rotation angle detection device A includes a pair of first elements 1 composed of Hall elements on the detection surface as a magnetic sensor MS, and a pair of second elements composed of Hall elements in a direction orthogonal to the direction in which the pair of first elements 1 are arranged. Since 2 is provided, it is possible to remove magnetic noise acting from the outside. Further, when the permanent magnets M rotate, the magnetic detection signal detected by the pair of first elements 1 is output as a sine wave, and the magnetic detection signal detected by the pair of second elements 2 is output as a cosine wave. Therefore, the rotation angle of the permanent magnet M can be detected from the phase difference between the two magnetic detection signals.

The permanent magnet M is divided by a plurality of virtual straight lines with respect to the magnetic pole surface to form four magnetic poles in which the north pole and the south pole are alternately arranged, and the width of the north pole and the south pole (parallel direction). (Width in the vertical direction in FIG. 6) is set to about 1.5 times the distance between the pair of first elements 1 (equal to the distance between the pair of second elements 2). Further, two magnetic sensors MS are arranged in parallel along the direction in which the magnetic poles are lined up (vertical direction in FIG. 6). In particular, the virtual line connecting the second directions (YY) of the two magnetic sensor MSs is oriented so as to be orthogonal to the direction in which the north and south poles of the permanent magnet are parallel to each other and overlap with the axis P. Is set to.

Further, when the permanent magnet M is rotated, magnetic fluxes of different magnetic poles are applied to the pair of first elements 1 of the two magnetic sensor MSs, and magnetic fluxes of different magnetic poles are applied to the pair of second elements 2. The configuration that can be made is realized.

As a specific detection mode, for example, when the permanent magnet M starts rotating from the initial posture Ra about the axis P with the pedal operation, the two magnetic sensors MS detect the rotation angle equally. Further, when the permanent magnet M reaches the vicinity of the intermediate posture Rb as the permanent magnet M rotates, the magnetic poles corresponding to the pair of first elements 1 are switched, but the magnetic poles after the switching are performed in the pair of first elements 1. The rotation angle can be detected. As a result, it is possible to detect the rotation of the permanent magnet M at a large angle.

In particular, in the present embodiment, the two magnetic sensors MS are configured so that the calculated values of the rotation angles are the same when they are normal. Therefore, when the calculated values of the rotation angles are different, one of them is used. It is possible to detect that the magnetic sensor MS has failed. Even in such a case, since the two magnetic sensor MSs are used, it is possible to detect the correct rotation angle based on the magnetic detection signal detected by the other magnetic sensor MS.

[Another Embodiment]
The present invention may be configured as follows in addition to the above-described embodiment (those having the same functions as those in the embodiment are designated by the same number and reference numeral as those in the embodiment).

(A) As shown in FIGS. 8 and 9, the permanent magnets M have a plurality of (three in this embodiment) parallel virtual planes having a posture orthogonal to the axis P as in the configuration described in the embodiment. It has a magnetic pole plane divided by a virtual straight line. The north pole and the south pole are alternately arranged in the four divided regions formed by the division. In the figure, the letter "N" is attached to the north pole and the letter "S" is attached to the south pole.

Further, in the other embodiment (b), the detection substrate 14 is provided with three magnetic sensors MS. That is, these three magnetic sensor MSs are arranged in parallel with the direction in which the magnetic poles of the permanent magnets M are parallel to each other in a state where the permanent magnets M are in the intermediate posture Rb shown in FIG.

In this configuration of the other embodiment (b), it is possible to detect the rotation angle in a range of about 80 °, which is slightly smaller than the rotation angle that can be detected in the embodiment. As described above, the number of magnetic sensor MSs may be three.

(B) The number of magnetic poles formed on the magnetic pole surface of the permanent magnet M is set to 4 or more. Further, four or more magnetic sensors MS are used. Even with such a configuration, even if the magnetic sensor MS fails, it is possible to output an appropriate detection signal without using the signal of the failed magnetic sensor MS.

(C) The first direction (XX) in which the pair of first elements 1 are arranged and the second direction (YY) in which the pair of second elements 2 are arranged are directions along the axis P. It does not necessarily have to intersect at an angle of 90 ° in the visual sense. For example, it can be configured to intersect at 60 °.

Even if the pair of first elements 1 and the pair of second elements 2 are arranged as in the other embodiment (c), the magnetic detection signals of the pair of first elements 1 and the pair of second elements 2 are arranged. It is also possible to calculate the angle of rotation based on the phase difference between the element 2 and the magnetic detection signal.

The present invention can be used in a rotation angle detection device that detects the rotation angle by a permanent magnet and a magnetic sensor that detects the magnetic flux of the permanent magnet.

1 1st element (magnetron conversion element)
2 Second element (magnetron conversion element)
M Permanent magnet MS Magnetic sensor P Axis core XX 1st direction YY 2nd direction

Claims (2)

With permanent magnets
A plurality of magnetic sensors arranged opposite to the permanent magnet and detecting the magnetic flux of the permanent magnet,
Is provided so that it can rotate relative to the center of the shaft.
The permanent magnet has a magnetic pole surface in which a plane orthogonal to the axis is divided into four or more poles by a plurality of parallel virtual straight lines.
The magnetic sensor has a function of canceling a disturbance magnetic field, and is configured to calculate a rotation angle relative to the permanent magnet based on the magnetic flux of the permanent magnet.
The plurality of magnetic sensors are arranged in parallel on the same plane, and the plurality of magnetic sensors are arranged in parallel.
The permanent magnet is a rotation angle detecting device in which the parallel direction of magnetic poles having four or more poles and the arrangement direction of the plurality of magnetic sensors can be parallel in a range of relative rotation with respect to the magnetic sensor. The magnetic sensor is arranged along a pair of magnetron conversion elements arranged along a first direction of a detection surface having a posture orthogonal to the axis, and a second direction different from the first direction on the detection surface. With another pair of magnetron conversion elements
In the situation where the magnetic flux of the permanent magnet acts on each of the pair of pairs of magnetic and electrical conversion elements, the magnetic sensor is a voltage generated from one of the pair of magnetic and electrical conversion elements according to the magnetic flux. And the magnetic detection signal of the pair of magnetic and electrical conversion elements arranged along the first direction while outputting a magnetic detection signal from the difference between the magnetic and electrical conversion elements and the voltage generated in response to the magnetic flux. , The relative rotation angle with respect to the permanent magnet is calculated from the phase difference between the pair of magnetic electric conversion elements arranged along the second direction and the magnetic detection signal.
A claim that magnetic fluxes of different polarities always act on one of the pair of magnetron-converting elements and the other magnetron-converting element in a range in which the permanent magnet rotates relative to the magnetometer. Item 1. The rotation angle detecting device according to Item 1.

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