JP6532060B2 - Rotation angle detection device - Google Patents

Description

  The present invention relates to a rotation angle detection device that detects a rotation angle of a rotating body, and more particularly to a rotation angle detection device that detects a rotation angle using a permanent magnet and a magnetic detection element.

  A rotating body rotating around a rotation center axis is used in various devices in various fields. At that time, in many cases, it has become necessary to detect the rotation angle of the rotating body. In the rotation angle detection device for detecting the rotation angle of the rotating body, a contact type for detecting the rotation angle by bringing the rotor into contact with the rotating body and a non-contact type for detecting the rotation angle without contacting the rotating body Use any type of detection scheme. In particular, in recent years, a non-contact type detection system has been used which can achieve long life because it has no contact portion.

  In such non-contact type rotation angle detection devices, detection methods (magnetic detection types) having magnetic detection means using permanent magnets and magnetic detection elements have been increasing year by year. In this magnetic detection type detection method, in order to facilitate the electrical connection with the magnetic detection element, it is general to arrange the magnetic detection element on the fixed side and arrange the permanent magnet on the rotation side. .

  Patent Document 1 (Conventional Example 1) proposes a throttle position sensor 800 for detecting the throttle opening of an internal combustion engine such as a car as this magnetic detection type rotation angle detection device. FIG. 13 is a view for explaining a throttle position sensor 800 of Conventional Example 1, and is a cross-sectional view showing an internal configuration.

  A throttle position sensor 800 shown in FIG. 13 includes a hollow housing 801, a hollow rotor 805 rotatably supported by bearings and made of a magnetic material, a lever fixed to the rotor 805 and receiving rotation of a throttle valve, and A strip-like holder 825 housing a permanent magnet 815 magnetized in a direction orthogonal to the rotation axis (rotation center axis), a Hall element 821 disposed around the rotation axis of the rotor, and the Hall element 821 And are configured. The throttle position sensor 800 changes the magnetic field as the permanent magnet 815 rotates via the lever and rotor 805 as the throttle valve rotates, and the change in the magnetic field is detected by the Hall element 821 to It is configured to detect the opening degree. Thus, the size of the expensive permanent magnet 815 can be increased by arranging the magnetic detection element (Hall element 821) around the rotation axis and arranging the permanent magnet 815 so as to surround the magnetic detection element. It can be made smaller and the external size of the rotation angle detection device (throttle position sensor 800) can be made smaller.

  On the other hand, there is a rotation angle detection device of a type in which the magnetic detection means can not be disposed at the center of the rotation axis, and in Patent Document 2 (Conventional Example 2), a rotation detection device 900 provided in a lens barrel 918 such as a camera is proposed. It is done. FIG. 14 is a view for explaining a rotation detection device 900 according to Conventional Example 2, and FIG. 14 (a) is a perspective view showing an example of the rotation detection device 900 provided in the lens barrel 918. (B) is a perspective view which shows the example of the inside of the rotation detection apparatus 900. FIG.

  A rotation detection device 900 shown in FIG. 14A is mounted on the front side of a lens barrel 918 such as a digital video camera recorder, and the amount and direction of rotation of a manually operated focus lens 931 rotated by the user's hand. Detection is in progress.

  Further, as shown in FIG. 14B, the rotation detecting device 900 includes a rotating body 920 that holds the focus lens 931 and rotates about the optical axis OL, and a magnet 930 held inside the rotating body 920, And a magnetic detection sensor 950 disposed to the side of the magnet 930. For this reason, the magnetic detection means (the magnet 930 or the magnetic detection sensor 950) can not be disposed in the portion of the optical axis OL of the focus lens 931. Then, in the rotation detection device 900, the magnet 930 rotates with the rotation of the rotating body 920 rotated by the user's hand, and the rotation of the magnet 930 causes a change in the magnetic field. It is configured to detect and detect the amount of rotation and the direction of rotation of the focus lens 931. As described above, in the case where the magnetic detection means can not be disposed around the rotation axis, there is a problem that the expensive permanent magnet (magnet 930) has to be enlarged. That is, there is a problem that the cost becomes higher.

JP-A-6-74708 JP 2001-255171 A

  Furthermore, for example, when there is a metallic throttle bar at the center, such as a throttle of a steering wheel portion of a motorcycle, and a rotation angle of a grip disposed around the center is detected, it is permanent on the outside of the throttle bar. The problem of having to arrange a magnet, an expensive permanent magnet becoming larger, and becoming more expensive has become increasingly prominent.

  On the other hand, by dividing the permanent magnet into several parts to reduce one size and arranging the plurality of permanent magnets apart, an effect equivalent to the case of using one large permanent magnet is obtained. It is expected that the rotation angle detector can be manufactured more inexpensively. However, since the small divided permanent magnets are disposed apart from each other, there is a possibility that a region where the change of the magnetic field becomes small may occur and detection accuracy of the rotation angle may be poor or undetectable rotation angle may occur. The

  The present invention solves the above-mentioned problem, and an object of the present invention is to provide a rotation angle detection device with high detection accuracy, in which a plurality of permanent magnets are disposed apart from each other.

In order to solve this problem, the rotation angle detection device of the present invention comprises a plurality of permanent magnets that rotate in conjunction with the rotational movement of a rotating body that rotates about a rotation center axis, and the generation of the permanent magnets In a rotation angle detection device comprising: a magnetic detection element that detects a magnetic field to be detected; and a processing unit that calculates a rotational angle of the rotating body based on a detection signal of the magnetic detection element, each of the plurality of permanent magnets The arc shape is obtained by dividing an annular shape along a virtual circle centered on the rotation center axis when viewed from the vertical plane side where the rotation center axis penetrates perpendicularly, and on the outer side of the rotating body The centers of the circular arc shapes are disposed at equal intervals at positions along the imaginary circle, and the plurality of permanent magnets are magnetized to a pair of S pole and N pole respectively, Among a plurality of permanent magnets, a center magnet and the center magnet The magnetic detection element is disposed to face the center magnet in an initial state, as viewed from the magnetic detection element side. The magnetized pole of the center magnet and the magnetized pole of the side magnet are different , and a plurality of the magnetic detection elements are provided, and one of the center magnet and two for each of the plurality of magnetic detection elements. so that the side magnets are characterized and arranged child said plurality of permanent magnets.

According to this, even when the small divided arc-shaped permanent magnets are arranged to be separated from each other, the rotation angle detection device of the present invention can form one permanent that is integrally formed within the measurement range. It is possible to obtain detection accuracy equal to or more than that in the case where the magnet is magnetized with a plurality of magnetic poles. In addition, since the permanent magnet divided into small pieces is used, it can be miniaturized and manufactured inexpensively. As a result, it is possible to provide a rotation angle detection device with high detection accuracy in which a plurality of permanent magnets are disposed separately. Further, the measurement range can be expanded by combining the rotation angles obtained from the plurality of magnetic detection elements. Also, a permanent magnet used as a center magnet for one magnetic detection element is used as a side magnet for another magnetic detection element, or another magnetic detection is used for a permanent magnet used as a side magnet for a magnetic detection element. It can also be used as a center magnet for the element, and the measurement range can be extended with fewer permanent magnets.

  In the rotation angle detection device according to the present invention, the magnetization direction of the plurality of permanent magnets is a first magnetization direction parallel to the rotation center axis, and the magnetic detection element is any one in the first magnetization direction. It is characterized in that it is disposed on one side so as to face the center magnet.

  According to this, the magnetic detection element is disposed on the side of the center magnet, and the external size in the radial direction can be reduced. In addition, the rotating body interlocked with the permanent magnet is disposed on the side side, and can be easily disposed with the magnetic detection element.

  In the rotation angle detection device according to the present invention, when viewed from the vertical plane side, in the initial state, a position corresponding to the center of the arc shape of the center magnet is a reference position, and the arc shape of the side magnet A position corresponding to the center is a separated position, a position where the center magnet is rotated from the initial state to move the center of the arc shape is a moved position, and the reference position and the moved position are the central axis of rotation. The angle to the angle is ± θ1 degrees, the angle between the separated position and the reference position to the rotation center axis is ± θ2 degrees, and both ends of the arc shape in the side magnet are the rotation center axis Assuming that the angle to be formed is θ3 degrees, XA and YA are constants, and XA is 1 ≦ XA ≦ 2.2, θ1 and θ2 have a relationship of θ1 ≦ θ2 ≦ XA × θ1 and θ3 is It is the relationship of θ3 = YA × θ1, θ Equation for minimizing the is characterized by YA = a XA-0.9.

  According to this, since θ1, θ2 and θ3 are determined so that the above-mentioned relational expression holds, it is possible to detect the rotation angle with higher accuracy. In particular, if θ3 (width size of the side magnet) is determined so that “YA = XA−0.9”, the width size of the side magnet becomes the smallest size. As a result, since the smallest permanent magnet can be used while securing detection accuracy, the size can be further reduced and the cost can be reduced.

  In the rotation angle detection device according to the present invention, the magnetization direction of the plurality of permanent magnets is a second magnetization direction in the radial direction orthogonal to the rotation center axis, and the magnetic detection element is a second magnetization direction. It is characterized by arrange | positioned so that the said center magnet may be opposed to the opposite side of the said rotation center axis in.

  According to this, the magnetic detection element is disposed on the outer side of the center magnet, and is disposed at a position where the change of the magnetic field is large when the permanent magnet is rotationally moved. Therefore, the magnetic detection element can more surely detect the change of the magnetic field, and the detection accuracy can be improved.

In the rotation angle detection device according to the present invention, when viewed from the vertical plane side, in the initial state, a position corresponding to the center of the arc shape of the center magnet is a reference position, and the arc shape of the side magnet A position corresponding to the center is a separated position, a position where the center magnet is rotated from the initial state to move the center of the arc shape is a moved position, and the reference position and the moved position are the central axis of rotation. The angle to the angle is ± 4 degrees, the angle between the separated position and the reference position to the rotation center axis is ± 5 degrees, and both ends of the arc shape in the side magnet are the rotation center axis Assuming that the angle to be formed is θ6 degrees, XB and YB are constants, and when XB is 1 ≦ XB ≦ 1.4, θ4 and θ5 have a relationship of θ4 ≦ θ5 ≦ XB × θ4, θ6 is The relationship of θ6 = YB × θ4, θ Equation for minimizing the is characterized here is ^{YB = 0.8 × XB 2 -0.3 ×} XB.

According to this, since θ4, θ5 and θ6 are determined so that the above-mentioned relational expression holds, it is possible to detect a rotation angle with higher accuracy. In particular, when θ6 (the width size of the side magnet) is determined so that “YB = 0.8 × XB ² −0.3 × XB”, the width size of the side magnet becomes the smallest size. As a result, since the smallest permanent magnet can be used while securing detection accuracy, the size can be further reduced and the cost can be reduced.

  According to the rotation angle detection device of the present invention, even when the small divided arc-shaped permanent magnets are arranged apart from each other, a plurality of magnetic poles can be formed on one permanent magnet integrally formed within the measurement range. It is possible to obtain detection accuracy equal to or higher than that in the case where the magnetizing is performed. In addition, since the permanent magnet divided into small pieces is used, it can be miniaturized and manufactured inexpensively. As a result, it is possible to provide a rotation angle detection device with high detection accuracy in which a plurality of permanent magnets are disposed separately.

It is a figure explaining the rotation angle detection apparatus of 1st Embodiment of this invention, Comprising: It is a schematic diagram of the handle with which a rotation angle detection apparatus is mounted | worn. It is a block diagram explaining the rotation angle detection apparatus of 1st Embodiment of this invention, Comprising: It is sectional drawing in the II-II line shown in FIG. It is a block diagram explaining the rotation angle detection apparatus of 1st Embodiment of this invention, Comprising: It is the top view seen from Z 1 side shown in FIG. It is a model figure used for the simulation in the rotation angle detection apparatus of 1st Embodiment of this invention, Comprising: The schematic diagram which showed the positional relationship of three permanent magnets and one magnetic detection element of this application. FIG. 4B is a schematic view showing the positional relationship between one permanent magnet and one magnetic detection element of the comparative example. It is a graph of the result of simulation AA in the rotation angle detection device of the first embodiment of the present invention, FIG. 5 (a) is the result of the model of the present invention, and FIG. 5 (b) is the model of the comparative example. It is a result. It is a graph of the result of simulation BB in the rotation angle detection apparatus of 1st Embodiment of this invention, Comprising: Fig.6 (a) is a result of the model of this application, FIG.6 (b) is a several permanent magnet. It is the result which showed the relation of each other. It is a block diagram explaining the rotation angle detection apparatus of 2nd Embodiment of this invention, Comprising: It is sectional drawing in the II-II line when a rotation angle detection apparatus is applied to the handle shown in FIG. It is a block diagram explaining the rotation angle detection apparatus of 2nd Embodiment of this invention, Comprising: It is the top view seen from Z 1 side shown in FIG. It is a block diagram explaining the rotation angle detection apparatus of 2nd Embodiment of this invention, Comprising: It is the figure which showed the flow of the magnetic field in the cross-section block diagram shown in FIG. It is a figure explaining the simulation result in the rotation angle detection apparatus of 2nd Embodiment of this invention, Comprising: Fig.10 (a) is a model figure used for simulation CC, Comprising: FIG.10 (b) is simulation CC It is the graph which showed the mutual relationship of several permanent magnets by the result of. It is a block diagram explaining the modification 1 of the rotation angle detection apparatus of 1st Embodiment of this invention, Comprising: It is the cross-section block diagram compared with FIG. It is a block diagram explaining the modification 3 of the rotation angle detection apparatus of 2nd Embodiment of this invention, Comprising: It is the cross-section block diagram compared with FIG. It is a figure explaining the throttle position sensor of the prior art example 1, Comprising: It is sectional drawing showing an internal structure. It is a figure explaining the rotation detection apparatus of the prior art example 2, Comprising: Fig.14 (a) is a perspective view which shows an example of the rotation detection apparatus provided in the lens-barrel, FIG.14 (b) is rotation detection. It is a perspective view which shows the example inside an apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1 is a schematic view of a handle HN on which a rotation angle detection device 100 according to a first embodiment of the present invention is mounted. FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. FIG. 3 is a top plan view seen from the Z1 side shown in FIG. In FIG. 3, the flow of the magnetic field is indicated by a two-dot chain line in order to make the description easy to understand. 1 to 3 show a state in which a rotating body RB10 described later is rotated from a stationary position and located at an intermediate position of the rotational movement range of the rotating body RB10. Note that this intermediate position is in the initial state.

  The rotation angle detection device 100 according to the first embodiment of the present invention is attached to a portion of the steering wheel HN such as a two-wheeled motor vehicle or a three-wheeled motor vehicle as shown in FIG. It is used to detect the rotation of the grip portion SH). The rotation angle detection device 100 is incorporated in the handle HN between the root of the brake lever RV and the attachment portion of the grip portion SH.

  As shown in FIGS. 2 and 3, rotation angle detection apparatus 100 detects magnetism generated by three permanent magnets 11 interlocked with rotating body RB 10 rotated by the operation of the operator and three permanent magnets 11. A magnetic detection element 13 and a processing unit 17 that calculates the rotation angle of the rotating body RB 10 based on the detection signal of the magnetic detection element 13 are configured.

  First, the permanent magnet 11 of the rotation angle detection device 100 will be described. The permanent magnet 11 is made of a magnet such as a neodymium magnet, and as shown in FIGS. 2 and 3, it comprises a center magnet 11C and side magnets 11S disposed one on each side of the center magnet 11C. There is. The three permanent magnets 11 (one center magnet 11C, two side magnets 11S) are disposed on the outer side of the rotating body RB10 and engaged with the rotating body RB10 (not shown). 2) in synchronization with the rotational movement of the rotating body RB10, about the rotation center axis RBj of the rotating body RB10 shown in FIG.

  Further, each of the three permanent magnets 11 is a virtual centering on the rotation center axis RBj when viewed from the vertical plane side where the rotation center axis RBj vertically penetrates, that is, viewed from the Y direction side (state of FIG. 2) It becomes circular arc shape which divided ring shape along a circle of. In other words, with respect to a virtual ring locus RT centered on the rotation center axis RBj, it has a ring divided piece shape which is divided by overlapping with the ring locus RT. Then, each of the three permanent magnets 11 is disposed at equal intervals at positions along the imaginary circle centered on the rotation center axis RBj, with the center of the arc shape (the center of the ring divided piece shape) There is. That is, they are disposed such that the angle θ2 shown in FIG. 2 (the angle (central angle) between the reference position described later and the separated position with respect to the rotation center axis RBj) is the same.

  Here, the definition of the positional relationship between the center magnet 11C and the side magnet 11S will be briefly described.

  First, as shown in FIG. 2, in the initial state (in the middle position of the rotational movement range of the rotating body RB10) as seen from the vertical plane side (Y direction side) where the rotation center axis RBj penetrates perpendicularly, as shown in FIG. A position corresponding to the center of the arc shape (ring divided piece shape) is taken as a reference position. Next, the position where the center magnet 11C is rotated from the initial state to move the center of the arc shape is set as the movement position. At that time, the side magnet 11S also moves in the same direction and in the same moving distance. Next, in the initial state, the position where the side magnet 11S is disposed, that is, the position corresponding to the center of the arc shape (ring divided piece shape) of the side magnet 11S is taken as the separated position.

  Then, as shown in FIG. 2, the angle (central angle) that the reference position and the movement position make with the rotation center axis RBj is ± θ1 degree. This ± θ1 degree is an angle range of measurement in the rotation angle detection device 100. Further, an angle (central angle) formed by the separated position and the reference position with respect to the rotation center axis RBj is ± θ2 degrees. This θ2 degree is the arrangement position of the side magnet 11S in the rotation angle detection device 100. At this time, the direction from the reference position exists in one direction (rotation direction to the X1 side shown in FIG. 2) and the other direction (rotation direction to the X2 side shown in FIG. 2). , Plus (one direction) and minus (other direction) values. In the first embodiment of the present invention, since the rotation angle detection device 100 is used to detect the rotation of the operation portion (grip portion SH) of the throttle, the angle range of θ1 degrees is 15 ° ≦ θ1. It is about ≦ 90 °.

  Furthermore, the angle (central angle) that the both ends of the arc shape in the side magnet 11S make with the rotation center axis RBj is θ3 degrees. The θ3 degree is the width size of the side magnet 11S in the rotation angle detection device 100.

  As described above, the positional relationship between the center magnet 11C and the side magnet 11S is defined.

  As shown in FIG. 3, the three permanent magnets 11 arranged in this manner are respectively magnetized to a pair of S pole and N pole, and the magnetization direction of the three permanent magnets 11 is the rotation center The first magnetization direction MD1 (Y direction shown in FIG. 3) is parallel to the axis RBj.

  Further, as shown in FIG. 3, the center magnet 11C and the side magnet 11S have different magnetization directions, and as shown in FIG. 2, when viewed from the magnetic detection element 13 side. (The state of the reference position in FIG. 2), the magnetized pole of the center magnet 11C and the magnetized pole of the side magnet 11S are different. Specifically, in FIG. 2, the magnetized pole of the center magnet 11 </ b> C is a south pole, and the magnetized pole of the side magnet 11 </ b> S is a north pole. As a result, as shown in FIG. 3, the flow of the magnetic field from the center magnet 11C to the left and right side magnets 11S and from the left and right side magnets 11S to the center magnet 11C is adjusted and formed.

  Next, the magnetic detection element 13 of the rotation angle detection device 100 will be described. The magnetic detection element 13 uses two Hall elements, and although not shown in detail, the magnetic detection element 13 is packaged with a thermosetting synthetic resin and mounted on a circuit board (not shown). The two Hall elements have sensitivity axes in the X and Y directions shown in FIG.

  Further, the magnetic detection element 13 is disposed to face the center magnet 11C in the initial state, and one side in the first magnetization direction MD1 of the center magnet 11C in the vicinity of the center magnet 11C (Y2 shown in FIG. Side). Thus, the magnetic detection element 13 is disposed on the side of the center magnet 11C, and the external size in the radial direction centering on the rotation center axis RBj can be reduced. In addition, the magnetic detection element 13 can be easily disposed because the magnetic body 13 is disposed on the side with respect to the rotating body RB 10 interlocked with the permanent magnet 11.

  Then, the magnetic detection element 13 detects a change in the magnetic field caused by the rotational movement of the three permanent magnets 11 by means of a two-axis Hall element to detect the rotational movement of the permanent magnet 11. In the first embodiment of the present invention, the magnetic detection element 13 is disposed on one side (Y2 side shown in FIG. 3) in the first magnetization direction MD1 of the center magnet 11C, but the present invention is not limited thereto. It may be disposed on the other side (the Y1 side shown in FIG. 3) in the first magnetization direction MD1.

  Finally, the processing unit 17 of the rotation angle detection device 100 is configured using an integrated circuit (IC, Integrated Circuit), and is connected to the magnetic detection element 13 (two Hall elements). The rotation angle of the rotating body RB10 is calculated based on the detection signal. The processing unit 17 is packaged together with the magnetic detection element 13 although not shown in detail.

  As described above, in the initial state, the rotation angle detection device 100 according to the first embodiment of the present invention has the arc-shaped center magnet 11C facing the magnetic detection element 13 and one each on both sides of the center magnet 11C. An arc-shaped side magnet 11S is provided, arranged at equal intervals, and viewed from the side of the magnetic detection element 13 (the state of FIG. 2), the magnetized pole of the center magnet 11C and The magnetic poles of the side magnets 11S are different from each other. As a result, even when the arc-shaped permanent magnets 11 divided into small pieces are arranged apart from each other, one magnet integrally formed in the measurement range is magnetized with a plurality of magnetic poles. It is possible to obtain equal or better detection accuracy. And since the permanent magnet 11 divided into small pieces is used, compared with the case where it forms with one big magnet, it can be miniaturized and it can manufacture at low cost.

Furthermore, when arranging the center magnet 11C and the side magnet 11S, if the following relational expression 1 is established, it is possible to detect a rotation angle with higher accuracy.
<Relational expression 1>
XA and YA are constants,
Let XA be 1 ≦ XA ≦ 2.2,
θ1 and θ2 satisfy θ1 ≦ θ2 ≦ XA × θ1
When YA is set to YA <XA,
θ3 is θ3 = YA × θ1.
That is, the separated position (θ2) of the side magnet 11S is not less than the measurement angle range (θ1) of the rotation angle detection device 100 and 2.2 times or less of the measurement angle range (θ1), and the width size of the side magnet 11S ( θ3) may be determined in consideration of the measurement angle range (θ1) and the separated position (θ2) of the side magnet 11S.

  In particular, if the width size (θ3) of the side magnet 11S is determined such that the ratio of the width size (θ3) of the side magnet 11S to the measurement angle range (θ1) is “YA = XA−0.9” The width size (θ3) of the side magnet 11S at this time is the smallest. As a result, since the smallest magnet can be used while securing the detection accuracy, the size can be further reduced and the cost can be reduced.

  Next, in order to verify the effect of the rotation angle detection device 100 according to the first embodiment of the present invention, two types of simulations, simulation AA and simulation BB, were performed. Below, this verification result is explained.

  FIG. 4 is a model diagram used for the simulation, and FIG. 4A shows three permanent magnets 11 (one center magnet 11 C, two sides in the rotation angle detection device 100 according to the first embodiment of the present invention). FIG. 4B is a model M01 showing the positional relationship between the magnet 11S) and one magnetic detection element 13, and FIG. 4B shows one permanent magnet H11 and one magnetic detection element 13 in the rotation angle detection device H100 of the comparative example. It is model ME1 which showed positional relationship. In the model ME1 of the comparative example, as shown in FIG. 4B, only one permanent magnet H11 is used, and the shape has a semicircular ring shape of about 180 °. Further, the permanent magnet H11 is divided into three segments and magnetized at equal intervals (each 60 °).

  First, simulation AA will be described. In the simulation AA, in the model M01 of the rotation angle detection device 100, the measurement angle range (θ1) and the separated position (θ2) of the side magnet 11S shown in FIG. The width size (θ3) of the two center magnets 11C and the two side magnets 11S) was set to 25 °. The radius R1 of the inner arc of the permanent magnet 11 was set to 15.6 (mm), and the radius R2 of the outer arc of the permanent magnet 11 was set to 18.3 (mm). Further, the distance between the permanent magnet 11 and the magnetic detection element 13 was set to 2.55 (mm). On the other hand, in the model ME1 of the rotation angle detection device H100 of the comparative example, each size {measurement angle range (θ1), radius R1 of inner arc, radius R2 of outer arc at portions other than the number and shape of permanent magnets H11 described above The distance between the permanent magnet H11 and the magnetic detection element 13} is the same as that of the model M01 of the rotation angle detection device 100.

  Next, the results of simulation AA using the above model M01 and model ME1 will be described. FIG. 5 shows the result of simulation AA, and FIG. 5 (a) is a graph showing an example of the output value in model M01 of the present application, and FIG. 5 (b) shows the output value in model ME1 of the comparative example. FIG. The horizontal axis is a measurement angle range (θ1 degree), and the vertical axis is an output value from the magnetic detection element 13.

  As shown in FIG. 5A, the output value of the rotation angle detection device 100 according to the first embodiment of the present invention changes almost linearly in the measurement angle range (θ1 degree). With such excellent linearity (linearity), the processing unit 17 can easily correct it into an ideal straight line.

  On the other hand, in the rotation angle detection device H100 of the comparative example, as shown in FIG. 5B, in the measurement angle range (θ1 degree), the output value is changed to a curve having several inflection points . As described above, when the output value changes in a curvilinear manner, it is difficult not only to correct to an ideal straight line by the processing unit 17 but also to be unable to correct in some cases.

  From these results, in the rotation angle detection apparatus 100 according to the first embodiment of the present invention, a plurality of permanent magnets 11 are disposed apart from each other, and one permanent magnet H11 integrally formed within the measurement range is provided. An effect is obtained that it is possible to obtain detection accuracy equal to or higher than that in the case of magnetizing with a plurality of magnetic poles.

  Next, simulation BB will be described. The simulation BB was performed by varying the separated position (θ2) of the side magnet 11S and the width size (θ3) of the permanent magnet 11 using the model M01 shown in FIG. 4A. 6 is a simulation BB, and FIG. 6 (a) is a graph showing another example different from the output value shown in FIG. 5 (a), and FIG. 6 (b) is a graph showing three permanent magnets 11 Are a graph that summarizes the constant XA and constant YA that represent the mutual relationship of and the result of the obtained output value. The horizontal axis in FIG. 6B is a constant XA, and the vertical axis is a constant YA. In addition, the white circle shown in FIG.6 (b) is a result equivalent to the output value shown to Fig.5 (a), and the black circle is a result equivalent to the output value shown to Fig.6 (a).

  The rotation angle detection device 100 according to the first embodiment of the present invention, as shown in FIG. 6A, has an output value in the measurement angle range (θ1 degree) depending on the relationship between the three permanent magnets 11. In some cases, a singular point PP (discontinuous point) may occur. However, except for the portion of the singular point PP, the output value changes linearly, which is different from the case of the curved output value having the inflection point as in the comparative example, by the processing unit 17 It is possible to correct to an ideal straight line including the portion of the singular point PP.

  On the other hand, as shown in FIG. 6B, the constant XA is 1 or more, that is, the separated position (θ2) of the side magnet 11S is the measurement angle range (θ1) or more of the rotation angle detection device 100, and the constant XA is 2.2. Hereinafter, the separated position (θ2) of the side magnet 11S is 2.2 times or less of the measurement angle range (θ1). Furthermore, the constant YA is set to 1.3 or less when "XA-0.9" or more.

  If it is this range mentioned above (portion of triangular cross hatching HB1 shown in FIG. 6 (b)), a value equivalent to the output value shown in FIG. 5 (a) can be obtained. In particular, when the width size (θ3) of the side magnet 11S is determined to be “θ1 × (XA−0.9)” (straight line LB1 shown in FIG. 6B), the width size of the side magnet 11S is most It becomes a small size. Thereby, the rotation angle detection apparatus 100 according to the first embodiment of the present invention has an effect that the smallest magnet can be used while securing the detection accuracy.

  The effects of the rotation angle detection apparatus 100 according to the first embodiment of the present invention configured as described above will be collectively described below.

  In the initial state, the rotation angle detection device 100 according to the first embodiment of the present invention has an arc-shaped center magnet 11C facing the magnetic detection element 13 and an arc shape disposed one on each side of the center magnet 11C. Side magnets 11S are provided, arranged at equal intervals, and when viewed from the magnetic detection element 13 side, the magnetized pole of the center magnet 11C and the magnetized pole of the side magnet 11S are different. Configured. As a result, even when the arc-shaped permanent magnets 11 divided into small pieces are arranged apart from each other, one magnet integrally formed in the measurement range is magnetized with a plurality of magnetic poles. It is possible to obtain equal or better detection accuracy. And since the permanent magnet 11 divided into small pieces is used, compared with the case where it forms with one big magnet, it can be miniaturized and it can manufacture at low cost. As a result, it is possible to provide the rotation angle detection device 100 with high detection accuracy, in which the plurality of permanent magnets 11 are disposed apart from each other.

  Further, the magnetic detection element 13 is disposed on one side (the Y2 side shown in FIG. 3) in the first magnetization direction MD1 parallel to the rotation center axis RBj so as to face the center magnet 11C. Is disposed on the side of the center magnet 11C, and the external size in the radial direction about the rotation center axis RBj can be reduced. In addition, the magnetic detection element 13 can be easily disposed because the magnetic body 13 is disposed on the side with respect to the rotating body RB 10 interlocked with the permanent magnet 11.

  Further, since θ1, θ2 and θ3 are determined so that the above-mentioned relational expression holds, it is possible to detect a rotation angle with higher accuracy. In particular, when θ3 (the width size of the side magnet 11S) is determined so that YA = XA−0.9, the width size of the side magnet 11S becomes the smallest size. As a result, since the smallest magnet can be used while securing detection accuracy, the size can be further reduced and the cost can be reduced.

Second Embodiment
FIG. 7 is a configuration diagram for explaining the rotation angle detection device 200 according to the second embodiment of the present invention, and a cross section along line II-II when the rotation angle detection device 200 is applied to the handle HN shown in FIG. FIG. FIG. 8 is a top view seen from the Z1 side shown in FIG. FIG. 9 is a diagram showing the flow of the magnetic field in a cross-sectional view shown in FIG. 7 by a two-dot chain line. Moreover, the rotation angle detection apparatus 200 of 2nd Embodiment differs in the magnetization direction of the permanent magnet 21, and the arrangement | positioning position of the magnetic detection element 23 with respect to 1st Embodiment. About the same composition as a 1st embodiment, the same numerals are attached and detailed explanation is omitted. Also, in FIGS. 4 to 6, as in the first embodiment, the rotating body RB10 is rotated from the stationary position, and is shown at the middle position of the rotational movement range of the rotating body RB10. . Note that this intermediate position is in the initial state.

  The rotation angle detection device 200 according to the second embodiment of the present invention is attached to a portion of the steering wheel HN such as a two-wheeled motor vehicle or a three-wheeled motor vehicle as shown in FIG. 1 as in the first embodiment. It is used to detect the rotation of the operation part (gripping part SH) of the throttle operated by.

  As shown in FIGS. 7 and 8, rotation angle detection apparatus 200 detects magnetism generated by three permanent magnets 21 interlocked with rotating body RB10 rotated by the operation of the operator and by three permanent magnets 21. A magnetic detection element 23 and a processing unit 27 that calculates the rotation angle of the rotating body RB 10 based on the detection signal of the magnetic detection element 23 are configured.

  First, the permanent magnet 21 of the rotation angle detection device 200 will be described. The permanent magnet 21 is made of a magnet such as samarium cobalt magnet and, as shown in FIGS. 7 and 8, includes a center magnet 21C and side magnets 21S disposed one on each side of the center magnet 21C. ing. The three permanent magnets 21 (one center magnet 21C and two side magnets 21S) are disposed on the outer side of the rotating body RB10 and engaged with the rotating body RB10 (not shown). 7) in synchronization with the rotational movement of the rotating body RB10, about the rotation center axis RBj of the rotating body RB10 shown in FIG.

  Further, as in the first embodiment, each of the three permanent magnets 21 rotates as viewed from the vertical plane side where the rotation center axis RBj penetrates perpendicularly, that is, viewed from the Y direction side (state in FIG. 7) It has an arc shape obtained by dividing an annular shape along a virtual circle centered on the central axis RBj. In other words, with respect to a virtual ring locus RT centered on the rotation center axis RBj, it has a ring divided piece shape which is divided by overlapping with the ring locus RT. Then, each of the three permanent magnets 21 is arranged at equal intervals at positions along the imaginary circle centered on the rotation center axis RBj, with the center of the arc shape (the center of the ring divided piece shape) There is. That is, they are arranged such that the angle θ5 (the angle (central angle) formed by the reference position and the separated position described later with respect to the rotation center axis RBj) shown in FIG. 7 is the same.

  Here, the definition of the positional relationship between the center magnet 21C and the side magnet 21S is similar to that of the first embodiment, but will be briefly described.

  First, as shown in FIG. 7, in the initial state (in the middle position of the rotational movement range of the rotating body RB10) as viewed from the vertical plane side (Y direction side) where the rotation center axis RBj penetrates perpendicularly, as shown in FIG. A position corresponding to the center of the arc shape (ring divided piece shape) is taken as a reference position. Next, the position where the center magnet 21C is rotated from the initial state to move the center of the arc shape is set as the movement position. At that time, the side magnet 21S also moves in the same direction and in the same moving distance. Next, in the initial state, the position where the side magnet 21S is disposed, that is, the position corresponding to the center of the arc shape (ring divided piece shape) of the side magnet 21S is taken as the separated position.

  Then, as shown in FIG. 7, the angle (central angle) that the reference position and the movement position make with the rotation center axis RBj is ± 4 degrees. This ± θ4 degree is an angle range of measurement in the rotation angle detection device 200. Further, the angle (central angle) formed by the separated position and the reference position with respect to the rotation center axis RBj is ± 5 degrees. The θ5 degree is the arrangement position of the side magnet 21S in the rotation angle detection device 200. At this time, the direction from the reference position exists in one direction (rotation direction to the X1 side shown in FIG. 7) and the other direction (rotation direction to the X2 side shown in FIG. 7). , Plus (one direction) and minus (other direction) values. Also in the second embodiment of the present invention, since the rotation angle detection device 200 is used to detect the rotation of the operation portion (grip portion SH) of the throttle, the angle range of θ4 degrees is 15 ° ≦ It is about θ4 ≦ 90 °.

  Furthermore, the angle (central angle) that the both ends of the arc shape in the side magnet 21S make with the rotation center axis RBj is θ6 degrees. The θ6 degree is the width size of the side magnet 21S in the rotation angle detection device 200.

  As described above, the positional relationship between the center magnet 21C and the side magnet 21S is defined.

  As shown in FIG. 7, the three permanent magnets 21 arranged in this manner are respectively magnetized to a pair of S pole and N pole, and the magnetization direction of the three permanent magnets 21 is the rotation center The second magnetization direction MD2 in the radial direction orthogonal to the axis RBj is obtained.

  Further, as shown in FIG. 7, the center magnet 21C and the side magnet 21S have different magnetization directions, and as shown in FIG. 8, when viewed from the magnetic detection element 23 side. (The state of the reference position in FIG. 8), the magnetized pole of the center magnet 21C and the magnetized pole of the side magnet 21S are different. Specifically, in FIG. 8, the magnetized pole of the center magnet 21C is the N pole, and the magnetized pole of the side magnet 21S is the S pole. As a result, as shown in FIG. 9, the flow of the magnetic field from the center magnet 21C to the left and right side magnets 21S and from the left and right side magnets 21S to the center magnet 21C is adjusted and formed.

  Next, the magnetic detection element 23 of the rotation angle detection device 200 will be described. Similar to the first embodiment, the magnetic detection element 23 uses two Hall elements, and although not shown in detail, it is packaged with a thermosetting synthetic resin and is not shown. Mounted on the. The two Hall elements have sensitivity axes in the X direction and the Z direction shown in FIG.

  In the initial state, the magnetic detection element 23 is disposed to face the center magnet 21C, and in the vicinity of the center magnet 21C, on the opposite side of the rotation center axis RBj in the second magnetization direction MD2 of the center magnet 21C. (It is arrange | positioned at Z1 side shown in FIG. 7). As a result, the magnetic detection element 23 is disposed on the outer side of the center magnet 21C, and is disposed at a position where the change in the magnetic field is large when the permanent magnet 21 is rotationally moved. For this reason, the magnetic detection element 23 can detect the change of the magnetic field more reliably.

  Then, the magnetic detection element 23 detects a change in the magnetic field caused by the rotational movement of the three permanent magnets 21 by means of a two-axis Hall element to detect the rotational movement of the permanent magnet 21. In the second embodiment of the present invention, the magnetic detection element 23 is disposed on the opposite side (Z1 side shown in FIG. 7) of the rotation center axis RBj in the second magnetization direction MD2 of the center magnet 21C. The present invention is not limited to the above, and it may be disposed between the rotational axis RBj in the second magnetization direction MD2 (the Z2 side shown in FIG. 7) and the rotating body RB10.

  Finally, as in the first embodiment, the processing unit 27 of the rotation angle detection device 200 is configured using an integrated circuit (IC, Integrated Circuit), and is connected to the magnetic detection element 23 (two Hall elements). Then, the rotation angle of the rotating body RB10 is calculated based on the detection signal of the magnetic detection element 23. The processing unit 27 is packaged together with the magnetic detection element 23 though not shown in detail.

  As described above, in the initial state, the rotation angle detection device 200 of the second embodiment of the present invention has the arc-shaped center magnet 21C facing the magnetic detection element 23, and one each on both sides of the center magnet 21C. An arc-shaped side magnet 21S is provided, arranged at equal intervals, and viewed from the magnetic detection element 23 side (the state of FIG. 8), the magnetized pole of the center magnet 21C and The magnetic poles of the side magnets 21S are different from each other. As a result, even when the arc-shaped permanent magnets 21 divided into small pieces are arranged separately from each other, one magnet integrally formed in the measurement range is magnetized with a plurality of magnetic poles. It is possible to obtain equal or better detection accuracy. Moreover, since the permanent magnet 21 divided into small pieces is used, it can be miniaturized and manufactured at low cost as compared with the case where it is formed by one large magnet.

Furthermore, when arranging the center magnet 21C and the side magnet 21S, if the following relational expression 2 is established, it is possible to detect a rotation angle with higher accuracy.
<Relational equation 2>
XB and YB are constants,
Let XB be 1 ≦ XB ≦ 1.4,
θ4 and θ5 satisfy θ4 ≦ θ5 ≦ XB × θ4,
When YB is YB <XB,
θ6 is θ6 = YB × θ4.
That is, the separated position (θ5) of the side magnet 21S is not less than the measurement angle range (θ4) of the rotation angle detection device 200 and 1.4 times or less of the measurement angle range (θ4), and the width size of the side magnet 21S ( θ6) may be determined in consideration of the measurement angle range (θ4) and the separated position (θ5) of the side magnet 21S.

In particular, the width size of the side magnet 21S is set such that the ratio of the width size (θ6) of the side magnet 21S to the measurement angle range (θ4) is “YB = 0.8 × XB ² −0.3 × XB”. If θ6) is determined, the width size (θ6) of the side magnet 21S at this time is the smallest. As a result, since the smallest magnet can be used while securing the detection accuracy, the size can be further reduced and the cost can be reduced.

  Next, simulation CC was performed in order to verify the effect in rotation angle detection apparatus 200 of a 2nd embodiment of the present invention. Below, this verification result is explained.

  FIG. 10 is a view for explaining the result of simulation CC in the rotation angle detection apparatus 200 of the second embodiment of the present invention, and FIG. 10 (a) is a model M02 used for the simulation CC. (B) is the graph which put together the result of the obtained output value with the constant XB and constant YB which represent the relationship of the three permanent magnets 21 mutually. The horizontal axis of FIG. 10B is the constant XB, and the vertical axis is the constant YB. The white circle shown in FIG. 10 (b) is the same result as the output value shown in FIG. 5 (a) as in the first embodiment, and the black circle is equivalent to the output value shown in FIG. 6 (a) Is the result of

  In the simulation CC, in the model M02 of the rotation angle detection device 200, the measurement angle range (± θ4) shown in FIG. 10A is ± 60 ° as in the first embodiment, and the radius of the inner arc of the permanent magnet 21 R1 is set to 15.6 (mm), radius R2 of the outer arc of permanent magnet 21 is set to 18.3 (mm), and the distance between permanent magnet 21 and magnetic detection element 23 is set to 2.55 (mm) . Then, the separation position (θ5) of the side magnet 21S and the width size (θ6) of the permanent magnet 21 were varied.

As a result, in the range of the cross hatching HB2 shown in FIG. 10B, a value equivalent to the output value shown in FIG. 5A can be obtained. That is, the separation position (θ5) of the side magnet 21S is the measurement angle range (θ4) when the separation position (θ5) of the side magnet 21S is the measurement angle range (θ4) or more of the rotation angle detection device 200 (constant XB is 1 or more). It is preferable to set the constant YB to 1.4 times or less (constant XB is 1.4 or less) and constant YB is “YB = 0.8 × XB ² −0.3 × XB” or more and 1.15 or less. In particular, when the width size (θ6) of the side magnet 21S is determined to be “θ4 × (0.8 × XB ² −0.3 × XB)” (straight line LB2 shown in FIG. The width size of the magnet 21S is the smallest. As a result, the rotation angle detection device 200 according to the second embodiment of the present invention has an effect that the smallest magnet can be used while securing detection accuracy.

  The effects of the rotation angle detection apparatus 200 according to the second embodiment of the present invention configured as described above will be collectively described below.

  In the initial state, the rotation angle detection device 200 according to the second embodiment of the present invention has an arc-shaped center magnet 21C facing the magnetic detection element 23 and an arc shape provided one on each side of the center magnet 21C. Side magnets 21S are provided at equal intervals, and when viewed from the magnetic detection element 23 side, the magnetized pole of the center magnet 21C and the magnetized pole of the side magnet 21S are different. Configured. As a result, even in the case where the arc-shaped permanent magnets 21 divided into small pieces are arranged to be separated from each other, one permanent magnet 21 integrally formed within the measurement range is magnetized by a plurality of magnetic poles. It is possible to obtain detection accuracy equal to or more than that in the case. Moreover, since the permanent magnet 21 divided into small pieces is used, it can be miniaturized and manufactured at low cost as compared with the case where it is formed by one large magnet. As a result, it is possible to provide the rotation angle detection device 200 with high detection accuracy, in which the plurality of permanent magnets 21 are disposed apart from each other.

  Since the magnetic detection element 23 is disposed opposite to the center magnet 21C on the opposite side of the rotation central axis RBj in the second magnetization direction MD2 orthogonal to the rotation central axis RBj, the magnetic detection element 23 is a center magnet It is disposed on the outer side of 21 C, and is disposed at a position where the change of the magnetic field is large when the permanent magnet 21 is rotationally moved. For this reason, the magnetic detection element 23 can detect the change of the magnetic field more reliably, and the detection accuracy can be improved.

Further, since θ4, θ5 and θ6 are determined so that the above-described relational expression holds, it is possible to detect a rotation angle with higher accuracy. In particular, when θ6 (the width size of the side magnet 21S) is determined so that YB = 0.8 × XB ² −0.3 × XB, the width size of the side magnet 21S becomes the smallest size. As a result, since the smallest magnet can be used while securing detection accuracy, the size can be further reduced and the cost can be reduced.

  The present invention is not limited to the above embodiment, and can be implemented, for example, as follows, and these embodiments also fall within the technical scope of the present invention.

  FIG. 11 is a configuration diagram for explaining a modification 1 of the rotation angle detection device 100 according to the first embodiment of the present invention, and is a cross-sectional configuration diagram of the rotation angle detection device D100 compared to FIG. FIG. 12 is a configuration diagram for explaining a modification 3 of the rotation angle detection device 200 according to the second embodiment of the present invention, and is a cross-sectional configuration diagram of the rotation angle detection device E200 compared to FIG.

<Modification 1><Modification2>
In the first embodiment, one set of the combination of the permanent magnet 11 of one center magnet 11C and two side magnets 11S and one magnetic detection element 13 is used. However, the present invention is not limited thereto. You may use a set. For example, as shown in FIG. 11, two sets of combinations of permanent magnets D1 of one center magnet D1C and two side magnets D1S and one magnetic detection element D13 may be used {Modified Example 1}. As a result, by combining the rotation angles obtained from the two magnetic detection elements D13, the measurement range can be expanded with a small number of permanent magnets E1. Also in the configuration of the second embodiment, a plurality of sets may be used {Modification 2}.

<Modification 3>
In the second embodiment, one set of the combination of the permanent magnet 21 of one center magnet 21C and two side magnets 21S and one magnetic detection element 23 is used. However, the present invention is not limited to this. The permanent magnet E1 and the plurality of magnetic detection elements E23 may be combined to form several sets. For example, as shown in FIG. 12, an EF set, an EG set, and two sets may be configured using five permanent magnets E1 and two magnetic detection elements E23. That is, the side magnet E1S used for one magnetic detection element E23 is used as the side magnet E1S for another magnetic detection element E23 and the permanent magnet E1 is shared {Modification 3 }. As a result, the measurement range can be expanded with a small number of permanent magnets E1.

<Modification 4><Modification5><Modification6>
Also, in the same manner, a combination of two sets can be configured using four permanent magnets E1 and two magnetic detection elements E23. That is, the permanent magnet E1 used as the center magnet E1C for one magnetic detection element E23 is used as the side magnet E1S for another magnetic detection element E23, and for one magnetic detection element E23. The permanent magnet E1 used as the side magnet E1S is used as the center magnet E1C with respect to another magnetic detection element E23, and the permanent magnet E1 is shared {Modification 4}. Also in the configuration of the first embodiment, the configuration of the third modification may be made {Modification 5}, and the configuration of the fourth modification may be made {Modification 6}.

<Modification 7>
In the above embodiment, Hall elements are used as the magnetic detection element 13 and the magnetic detection element 23. However, the present invention is not limited thereto. For example, GMR (Giant Magneto Resistive) elements, MR (Magneto Resistive) elements, AMR (Anisotropic Magneto) It may be a Resistive element, a TMR (Tunnel Magneto Resistive) element, or the like.

<Modification 8>
In the above-mentioned embodiment, although it applied suitably to the portion of the throttle provided in grip part SH of steering wheel HN, such as motorcycles and three-wheeled vehicles, it is not restricted to this and application is possible if it is a rotating part .

  The present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the scope of the present invention.

11, 21, D1, E1 Permanent magnets 11C, 21C, D1C, E1C Center magnets 11S, 21S, D1S, E1S Side magnets 13, 23, D13, E23 Magnetic detection elements 17, 27 Processing unit RB10 Rotor RBj Central axis of rotation MD1 First magnetization direction MD2 Second magnetization direction 100, 200, D100, E200 Rotation angle detection device

Claims (5)

A plurality of permanent magnets that rotate in conjunction with the rotational movement of the rotating body that rotates about the central axis of rotation;
A magnetic detection element for detecting the magnetism generated by the permanent magnet;
A processing unit configured to calculate a rotation angle of the rotating body based on a detection signal of the magnetic detection element;
Each of the plurality of permanent magnets has an arc shape obtained by dividing an annular shape along a virtual circle centered on the central axis of rotation, as viewed from the vertical plane side where the central axis of rotation penetrates perpendicularly, It is disposed on the outer side of the rotating body, and is disposed so that the center of the arc shape is equally spaced at a position along the imaginary circle,
The plurality of permanent magnets are respectively magnetized to a pair of S pole and N pole,
Among the plurality of permanent magnets, it has a center magnet and side magnets disposed one on each side of the center magnet,
The magnetic detection element is disposed to face the center magnet in an initial state,
When viewed from the magnetic detection element side, the magnetized pole of the center magnet and the magnetized pole of the side magnet are different ,
A plurality of the magnetic detection elements are provided,
Wherein for each of a plurality of magnetic detection elements, one of the such that the center magnet and two of the side magnets, the rotation angle detecting device comprising a disposed child said plurality of permanent magnets. The magnetization direction of the plurality of permanent magnets is a first magnetization direction parallel to the rotation center axis,
The rotation angle detection device according to claim 1, wherein the magnetic detection element is disposed on one side in the first magnetization direction so as to face the center magnet. Seen from the vertical plane side,
In the initial state, a position corresponding to the center of the arc shape of the center magnet is set as a reference position, and a position corresponding to the center of the arc shape of the side magnet is set as the separated position.
From the initial state, the center magnet is pivoted to move the center of the arc shape to a moving position,
The angle between the reference position and the movement position with respect to the rotation center axis is ± θ1 degree,
The angle between the separated position and the reference position with respect to the rotation center axis is ± θ2 degrees,
The angle between both ends of the arc shape in the side magnet and the rotation center axis is θ3 degrees,
XA and YA are constants,
When XA is 1 ≦ XA ≦ 2.2,
θ1 and θ2 have a relationship of θ1 ≦ θ2 ≦ XA × θ1
θ3 has a relationship of θ3 = YA × θ1,
The relational expression for minimizing θ3 is YA = XA−0.9.
The rotation angle detection device according to claim 2, characterized in that: The magnetization direction of the plurality of permanent magnets is a second magnetization direction in the radial direction orthogonal to the rotation center axis,
The rotation angle detection device according to claim 1, wherein the magnetic detection element is disposed on the opposite side of the rotation center axis in the second magnetization direction so as to face the center magnet. . Seen from the vertical plane side,
In the initial state, a position corresponding to the center of the arc shape of the center magnet is set as a reference position, and a position corresponding to the center of the arc shape of the side magnet is set as the separated position.
From the initial state, the center magnet is pivoted to move the center of the arc shape to a moving position,
The angle between the reference position and the movement position with respect to the rotation center axis is ± 4 degrees,
The angle between the separated position and the reference position with respect to the rotation center axis is ± 5 degrees,
The angle between the two end portions of the arc shape in the side magnet and the rotation center axis is θ 6 degrees,
XB and YB are constants,
When XB is 1 ≦ XB ≦ 1.4,
θ4 and θ5 have a relationship of θ4 ≦ θ5 ≦ XB × θ4,
θ6 has a relationship of θ6 = YB × θ4,
The relational expression for minimizing θ 6 is YB = 0.8 × XB2−0.3 × XB
The rotation angle detection device according to claim 4, wherein