Magnetic detector, magnetic detection module, magnetic detection system, gear drive detector, motor drive detector, and encoder

Abstract

To provide a magnetic detector that has a smaller number of components and can be configured compactly, and a magnetic detection module and the like comprising the magnetic detector.SOLUTION: A magnetic detector comprises a first detection part, a magnet, and a second detection part arranged in order along one direction. The first detection part detects a change in magnetism from the magnet occurring due to a first projection row formed of one or more projections provided on a movable body passing between the first detection part and the magnet along with the movement of the movable body. The second detection part detects a change in magnetism from the magnet occurring due to a second projection row formed of one or more projections provided on the movable body passing between the magnet and the second detection part along with the movement of the movable body.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a magnetic detection device, a magnetic detection module, a magnetic detection system, a gear drive detection device, a motor drive detection device, and an encoder. [Background technology]

[0002] Various detection devices are known that detect the rotation angle of a rotating body or the displacement position of a linear moving body. Among them, magnetic detection devices have the characteristic of being able to detect the angle and position of the moving body to be detected without contact, and are therefore widely used even in environments with a lot of ambient light, dust, etc. that are unfavorable for sensing. For example, they are used as rotation angle detection devices for internal combustion engines (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 177794 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0004] When detecting the rotation angle of a rotating body or the displacement position of a linear moving body, it is sometimes desirable to detect the absolute rotation angle or displacement position relative to a measurement reference, rather than the relative rotation angle (i.e., rotation amount) or displacement position (i.e., displacement amount). In such cases, a separate detection unit for detecting the measurement reference provided on the moving body is generally provided in addition to the detection unit for detecting the relative rotation angle or displacement position. However, considering that magnetic detection devices are used in a variety of environments, it is desirable to configure them with as few parts as possible and in a compact size.

[0005] The present invention has been made to solve such problems, and provides a magnetic detection device that can be configured compactly with a small number of parts, as well as a magnetic detection module, a magnetic detection system, a gear drive detection device, and a motor drive detection device that are equipped with the magnetic detection device. [Means for solving the problem]

[0006] A magnetic detection device in a first aspect of the present invention comprises a first detection unit, a magnet, and a second detection unit arranged in sequence along one direction, wherein the first detection unit detects a change in magnetic field from the magnet caused by a first convex row consisting of at least one convex portion provided on a moving body passing between the first detection unit and the magnet as the moving body moves, and the second detection unit detects a change in magnetic field from the magnet caused by a second convex row consisting of at least one convex portion provided on the moving body passing between the magnet and the second detection unit as the moving body moves.

[0007] A magnetic detection module according to a second aspect of the present invention includes the magnetic detection device described above, and a base portion that positions the first detection portion, the magnet, and the second detection portion of the magnetic detection device.

[0008] A magnetic detection system according to a third aspect of the present invention includes the above magnetic detection device and the above moving body.

[0009] Moreover, a gear drive detection device according to a fourth aspect of the present invention includes the above-described magnetic detection system.

[0010] A motor drive detection device according to a fifth aspect of the present invention includes the above magnetic detection system.

[0011] Moreover, an encoder according to a sixth aspect of the present invention includes the above magnetic detection system. [Effects of the Invention]

[0012] The present invention provides a magnetic detection device that can be configured compactly with a small number of parts, as well as a magnetic detection module, a magnetic detection system, a gear drive detection device, and a motor drive detection device that include the magnetic detection device. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an overall view showing the overall configuration of a magnetic detection system according to a first embodiment. [Figure 2] FIG. 2 is an enlarged partial perspective view showing a main part of the magnetic detection system. [Figure 3] FIG. 2 is an enlarged view of a main part for explaining the arrangement and function of the magnetic detection device. [Figure 4] 5A and 5B are diagrams showing changes in the output of each sensor with the rotation of a rotating body. [Figure 5] 10 is a diagram illustrating the relationship between the interval between adjacent first protrusions and the width of the first protrusions. FIG. [Figure 6] FIG. 10 is a diagram showing a simulation result of detected magnetic flux distribution with respect to tooth width ratio. [Figure 7] 10 is a diagram for explaining the difference in output of the third sensor depending on whether or not a yoke is present. FIG. [Figure 8] FIG. 10 is an overall view showing the overall configuration of a magnetic detection system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, components with the same reference numerals have the same or similar configurations. Furthermore, when multiple structures with the same or similar configurations exist in each drawing, some may be referenced with the same reference numerals and others may not be referenced with the same reference numerals to avoid complication. Note that the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problem.

[0015] 1 is an overall view showing the overall configuration of a magnetic detection system 10 according to a first example of this embodiment. The magnetic detection system 10 is composed of a rotor 200 attached and fixed to a rotating shaft 910, and a magnetic detection module 100 that detects the rotation angle of the rotor 200.

[0016] Rotating body 200 is mainly composed of a disk portion 210, a joint portion 220, a first convex portion 230, and a second convex portion 240. Rotating body 200 is formed entirely from a plate-shaped soft magnetic material, and more specifically, joint portion 220, first convex portion 230, and second convex portion 240 are produced by punching and bending processes.

[0017] The disc portion 210 functions as a base material of the rotating body 200. The disc portion 210 may be hollowed out in the radial direction, for example. The joint portion 220 functions as an attachment portion for attachment to the rotating shaft 910. The joint portion 220 may be crimped to the rotating shaft 910, or may be attached via an attachment / detachment mechanism. The rotating body 200 rotates integrally with the rotating shaft 910 by being attached to the rotating shaft 910 via the joint portion 220. Note that in this embodiment, the rotating shaft 910 will be described as being capable of rotating both clockwise (CW) and counterclockwise (CCW) as shown in the drawing.

[0018] A plurality of first protrusions 230 are provided along the circumferential direction on the periphery of the disc portion 210. Specifically, each first protrusion 230 is formed by bending each of the tongue pieces provided radially on the periphery of the disc portion 210 so that they stand upright relative to the plane of the disc portion 210. The width direction of the first protrusions 230 formed in this manner is the direction along the circumferential direction of the disc portion 210. In this embodiment, a case will be described as an example in which 30 first protrusions 230 are formed at equal intervals along the periphery of the disc portion 210. These first protrusions 230 that stand upright along the circumferential direction collectively form a first protrusion row.

[0019] The second protrusion 240 is formed by bending a tongue piece formed by punching on the circular plate portion 210 on the inner side of the periphery where the first protrusion 230 is provided so that the tongue piece stands upright relative to the plane of the circular plate portion 210, similar to the first protrusion 230. The width direction of the second protrusion 240 is the direction along the circumferential direction of the circular plate portion 210, similar to the width direction of the first protrusion 230. As will be described later, a plurality of second protrusions 240 may be provided along concentric circles, but in this embodiment, a case where one second protrusion 240 is formed on the inner side of the periphery of the circular plate portion 210 will be described as an example. One or more second protrusions 240 formed in this manner are considered to collectively constitute a second protrusion row.

[0020] The magnetic detection module 100 is attached and fixed to a support (not shown) via an attachment portion 120. A housing 110 of the magnetic detection module 100 functions as a base portion that positions each element of a magnetic detection device (described later). The magnetic detection device provided in the housing 110 detects the first convex portion 230 of the first convex row and the second convex portion 240 of the second convex row, which move relative to the magnetic detection module 100, by detecting changes in magnetism.

[0021] In this embodiment, as shown by the coordinate axes in the drawing, the rotation axis direction of the rotating shaft 910 is defined as the Z-axis direction, and the two axes that are opposite the Z-axis direction are defined as the X-axis and Y-axis directions. In the subsequent drawings, similar coordinate axes based on the state in which the magnetic detection system 10 is installed as in FIG. 1 are also included to indicate the orientation of the structure depicted in each drawing.

[0022] 2 is an enlarged partial perspective view showing a main part of the magnetic detection system 10. A housing 110 of the magnetic detection module 100 supports each element of the magnetic detection device, and an output signal of a magnetic sensor (described later) is output to a signal processing circuit via a connector (not shown) inserted into a connector insertion port 130.

[0023] Housing 110 has first slit 141 and second slit 142. First slit 141 is a space that allows rotating first convex portion 230 to pass through. Second slit 142 is a space that allows similarly rotating second convex portion 240 to pass through. As will be described in detail later, the magnetic sensor detects magnetism that changes when first convex portion 230 passes through first slit 141 and when second convex portion 240 passes through the second slit.

[0024] 3 is an enlarged view of the main part for explaining the arrangement and function of the magnetic detection device. a 1 and 2. The device includes a first detection unit 160, a magnet 150, a yoke 151, and a second detection unit 170, which are arranged along a straight line (shown by a dashed line in the figure) that passes through the first protrusion 230 and is parallel to the Y axis. In this embodiment, the first detection unit 160 is composed of a first sensor 161 and a second sensor 162, which are arranged along the movement direction of the first protrusion 230 so as to sandwich the straight line. The first detection unit 160, the magnet 150, the yoke 151, and the second detection unit 170 are supported and fixed at predetermined positions on the housing 110 shown in FIGS. 1 and 2. However, in FIG. 3, the housing 110 is not shown except for the dotted lines that indicate the spaces of the first slit 141 and the second slit 142.

[0025] First sensor 161 and second sensor 162 constituting first detection unit 160 are both magnetic sensors, such as a linear Hall IC. As rotating body 200 rotates, first convex portion 230 passes through first slit 141 set between first sensor 161 and second sensor 162 and magnet 150. As will be described in detail later, when first convex portion 230 passes through first slit 141, the magnetism from magnet 150 is temporarily blocked, and therefore first sensor 161 and second sensor 162 each output an analog signal corresponding to the passage of first convex portion 230.

[0026] In this embodiment, the second detection unit 170 is composed of one magnetic sensor, and is therefore referred to as the third sensor 170. The third sensor 170 is, for example, a switch-type Hall IC. As the rotating body 200 rotates, the second convex portion 240 passes through a second slit 142 that is set between the magnet 150 and the third sensor 170. As will be described in detail later, when the second convex portion 240 passes through the second slit 142, the magnetism from the magnet 150 is temporarily blocked, and the third sensor 170 outputs a binary signal (digital signal) corresponding to the passage of the second convex portion 240.

[0027] Magnet 150 is a permanent magnet, and in this embodiment, a Hall IC is used as the magnetic sensor, so its magnetization direction is parallel to the direction indicated by the dashed line. Yoke 151 is disposed adjacent to the surface of magnet 150 facing third sensor 170, and limits the magnetic field from magnet 150 toward third sensor 170. Yoke 151 has an opening 151a near its center, which is involved in limiting the magnetic field from magnet 150 toward third sensor 170. The specific functions of yoke 151 and opening 151a will be described later.

[0028] 4 is a diagram showing changes in the output of each sensor as the rotating body 200 rotates. The upper diagram in FIG. 4 shows the analog signal output of each sensor when the rotating body 200 rotates counterclockwise (CCW), particularly showing the state before and after the second convex portion 240 passes through the second slit 142. The horizontal axis represents the rotation angle (deg), and the vertical axis represents the detected magnetic flux density (T). The solid line L1 represents the output of the first sensor 161, the dotted line L2 represents the output of the second sensor 162, and the dashed-dotted line S represents the analog output of the third sensor 170.

[0029] The output of the first sensor 161 decreases as the first protrusion 230 approaches the gap between the first sensor 161 and the magnet 150 and increases as the gap moves away. When one first protrusion 230 passes, its output signal forms an approximately sinusoidal curve of one wavelength, and this signal repeatedly increases and decreases with each passing first protrusion 230. In other words, if the rotation speed of the rotor 200 is constant, the output of the first sensor 161 becomes an approximately sinusoidal signal with a constant period. Furthermore, the bottom-to-bottom distance C in the figure of the output represents the rotation angle corresponding to adjacent first protrusions 230, and in this embodiment, since 30 first protrusions 230 are provided along the periphery of the disc portion 210 as described above, this distance corresponds to 12°.

[0030] The output of the second sensor 162 is similar to the output of the first sensor 161. That is, the output decreases as the first convex portion 230 approaches the gap between the second sensor 162 and the magnet 150 and increases as the gap moves away. The second sensor 162 is disposed apart from the first sensor 161 along the movement direction of the first convex portion 230. Therefore, when the rotation direction of the rotating body 200 is counterclockwise, the output of the second sensor 162 exhibits a fluctuation that follows the output of the first sensor 161 with a delay, as shown in the figure. Conversely, when the rotation direction of the rotating body 200 is clockwise, the output of the first sensor 161 exhibits a fluctuation that follows the output of the second sensor 162 with a delay. Therefore, as in this embodiment, if the first detection unit 160 is composed of two sensors (the first sensor 161 and the second sensor 162) installed along the movement direction of the first convex portion 230, the rotation direction of the rotating body 200 can also be detected by observing the fluctuations in the outputs of the two sensors.

[0031] In this embodiment, multiple first protrusions 230 are provided at regular intervals along the periphery of disc portion 210, and therefore the outputs of first sensor 161 and second sensor 162 each exhibit periodic fluctuations as described above. On the other hand, as described above, only one second protrusion 240 is provided slightly inward from the periphery of disc portion 210. Therefore, the internal analog signal of third sensor 170 exhibits fluctuations that are constant when second protrusion 240 is sufficiently far away, decrease as second protrusion 240 approaches between magnet 150 and third sensor 170, and increase as the second protrusion 240 moves away from magnet 150, before recovering to a constant output.

[0032] The third sensor 170 is a switch-type IC as described above, and when the value of the internal analog signal falls below the threshold Th1, the binary output of the IC becomes V low From V high When the value of the internal analog signal recovers to the threshold value Th2, the binary output of the IC changes to V high From V low The signal processing circuit, for example, switches from the binary output of an IC to V low From V high The attitude of the rotating body 200 at the time when the state is switched to the reference state can be determined as the measurement reference (for example, rotation angle = 0°). Then, by observing the fluctuations in the outputs of the first sensor 161 and the second sensor 162 from that reference point, the rotation angle of the rotating body 200 from the measurement reference can be calculated. In other words, the attitude of the rotating body 200 at the time of measurement can be identified.

[0033] In the above description, the outputs of first sensor 161 and second sensor 162 are described as being approximately sinusoidal curves. If the outputs are sinusoidal curves, the rotation angle at a point between two adjacent first convex portions 230 can also be calculated using an inverse trigonometric function. Therefore, if it is desired to measure the rotation angle of rotating body 200 as a continuous value, the outputs of at least one of first sensor 161 and second sensor 162 must be sinusoidal curves. However, in order for the outputs to be sinusoidal curves, the positions of magnet 150, first sensor 161, and second sensor 162 must be adjusted, and consideration must also be given to the shape of first convex portion 230.

[0034] 5 is a diagram for explaining the relationship between the interval between adjacent first protrusions 230 and the width of the first protrusions 230. As shown in the figure, the interval between adjacent first protrusions 230 is determined by the rotation center S of the rotating body 200. a The angle between the diameters is C S In this embodiment, 30 first protrusions 230 are provided along the periphery of the disk portion 210, so C S = 12°. a The angle between the diameters connecting these points is C W Then, the ratio R of the width of the first protrusion 230 to the distance between two adjacent first protrusions 230 is c is R c =C W / C S It can be defined as:

[0035] R c When R is small, the first sensor 161 is not blocked much by the first protrusion 230 and receives the magnetic field of the magnet 150 for a long period of time, so the solid line L1, which is the output curve of the first sensor 161 shown in FIG. 4, has a flat portion at the maximum value. cWhen R is large, the period during which the first sensor 161 is blocked by the first protrusion 230 becomes longer and the period during which it is directly subjected to the magnetism of the magnet 150 becomes shorter, so the solid line L1, which is the output curve of the first sensor 161 shown in FIG. 4, has a shallower valley shape including the minimum value and becomes smaller. The same is true for the output of the second sensor 162. That is, R c If is not in the appropriate range, the sensor output will not form a sine wave curve.

[0036] After much trial and error by the inventors, R c It was found that the sensor output can be easily adjusted to a sine wave curve when the tooth width ratio (R c ) is a graph showing the simulation results of the detected magnetic flux distribution with respect to the rotation angle (deg), and the vertical axis represents the detected magnetic flux density (T). As shown in the legend, each curve is c This shows the change when R is 5%, 8%, 20%, 30%, 40%, 50%, and 75%. c It can be seen that when R is between 8% and 40%, it can be treated as a sine wave. In particular, the waveform at 20% matches the sine wave well, so R c It can be said that it is preferable that R is in the range of 10% to 30%, for example. c By adopting a first convex row, which is a collection of first convex portions 230 adjusted to fall within such a range, the arrangement of the magnet 150 and each sensor can be adjusted relatively easily, and as a result, each sensor can be made to output a curve that at least approximates a sine wave curve.

[0037] The second slit 142 is located closer to the center of rotation S than the position where the magnet 150 is disposed. a The third sensor 170 is further provided on the rotation center S aThe third sensor 170 is provided on the magnet 150 side. Therefore, the area in which the third sensor 170 can be placed is often limited. Ideally, it would be desirable to optimally place the magnet 150 in order to obtain an appropriate output, as with the first sensor 161 and the second sensor 162, but such optimal placement is difficult for the third sensor 170. Therefore, in this embodiment, a yoke 151 is disposed adjacent to the surface of the magnet 150 facing the third sensor 170 so that an appropriate output can be obtained even when the third sensor 170 is placed in a limited area. The yoke 151 serves to adjust the magnetic field reaching the third sensor 170 from the magnet 150.

[0038] 7 is a diagram illustrating the difference in output of third sensor 170 depending on whether yoke 151 is present or not. The horizontal axis represents the rotation angle (deg), and the vertical axis represents the detected magnetic flux density (T). The solid line represents the analog stage output of third sensor 170 when yoke 151 is not provided, and the dashed line represents the analog stage output of third sensor 170 when yoke 151 is provided.

[0039] In many cases, the placement position of the third sensor 170 is limited to an area close to the magnet 150. If the third sensor 170 is placed in an area close to the magnet 150, the magnetic detection module 100 as a whole can be made smaller. However, if the third sensor 170 is placed in such an area, the magnetic flux density detected by the third sensor 170 becomes larger overall, as shown by the solid line, and the amount of decrease (D n ) is also insufficient, resulting in flat areas near the bottom of the valley.

[0040] On the other hand, even if the third sensor 170 is disposed in the same position, if the yoke 151 is provided, the magnetic flux density detected by the third sensor 170 will be slightly smaller overall, as shown by the dashed line, and when the second convex portion 240 passes, the amount of decrease (D e ) forms a large V-shaped valley. In particular, in this embodiment, the opening 151a is provided in the yoke 151, so the amount of drop D eIn other words, the magnetic flux density detected when the second convex portion 240 passes by changes more significantly. When the detected magnetic flux density changes more significantly in this way, V low From V high This makes the timing of switching to more stable, allowing for more accurate detection of the measurement standard.

[0041] The size of opening 151a provided in yoke 151 is determined appropriately depending on the magnetic force of magnet 150 and the arrangement position of third sensor 170. Depending on these conditions, opening 151a may not be provided. Opening 151a may be formed in a slit shape in yoke 151 (for example, yoke 151 may be composed of two independent parts with a gap between them). Also, yoke 151 may be formed in a U-shape. That is, it is sufficient that yoke 151 is configured so as not to cover a portion of magnet 150. In this embodiment, yoke 151 is disposed adjacent to the surface of magnet 150 facing third sensor 170. However, depending on the relationship between magnet 150 and first sensor 161 and second sensor 162, yoke 151 may be disposed adjacent to the surfaces facing the sensors. In this case, two openings 151a may be provided corresponding to first sensor 161 and second sensor 162, respectively.

[0042] Next, a second example according to this embodiment will be described. Fig. 8 is an overall view showing the overall configuration of a magnetic detection system 20 according to the second example. In the magnetic detection system 10 according to the first example, the moving body to be detected by the magnetic detection module 100 was a rotating body 200. That is, the magnetic detection system 10 was a system that detected the rotation angle of the rotating body 200, and ultimately the rotating shaft 910. In the magnetic detection system 20 according to the second example, the moving body to be detected by the magnetic detection module 100 is, for example, a linear moving body 300 that reciprocates in the horizontal direction (the X-axis direction in Fig. 8).

[0043] The magnetic detection system 20 is composed of a linear moving body 300 attached and fixed to a reciprocating slider 920, and a magnetic detection module 100. In this embodiment, the magnetic detection module 100 detects the displacement position of the linear moving body 300, and therefore the reciprocating slider 920.

[0044] The linear moving body 300 is mainly composed of a flat plate portion 310, a joint portion 320, a first convex portion 330, and a second convex portion 340. The linear moving body 300 is formed entirely from a plate-shaped soft magnetic material, and more specifically, the joint portion 320, the first convex portion 330, and the second convex portion 340 are produced by punching and bending.

[0045] The flat plate portion 310 functions as the base material of the linear moving body 300. The joint portion 320 functions as an attachment portion for attachment to the reciprocating slider 920. The linear moving body 300 is attached to the reciprocating slider 920 via the joint portion 320, and thereby moves linearly integrally with the reciprocating slider 920. Note that in this embodiment, the reciprocating slider 920 will be described as moving reciprocally to the right (R) and left (L) as shown in the drawing.

[0046] A plurality of first protrusions 330 are provided along the linear motion direction on one side edge of the flat plate portion 310. Specifically, each first protrusion 330 is formed by bending each of the comb-shaped tongue pieces provided on the side edge portion of the flat plate portion 310 so that they stand upright relative to the plane of the flat plate portion 310. The width direction of the first protrusions 330 formed in this manner is the direction along the longitudinal direction (linear motion direction) of the flat plate portion 310. These first protrusions 330 standing upright along the longitudinal direction collectively form a first protrusion row.

[0047] The second protrusion 340 is formed by bending a tongue piece formed by punching on the flat plate portion 310 on the inner side of the side edge where the first protrusion 330 is provided so that the tongue piece stands upright relative to the plane of the flat plate portion 310, similar to the first protrusion 330. The width direction of the second protrusion 340 is the direction along the longitudinal direction of the flat plate portion 310, similar to the width direction of the first protrusion 330. Although a plurality of second protrusions 340 may be provided along the longitudinal direction, in this embodiment, one second protrusion 340 is formed on the inner side of the side edge of the flat plate portion 310. One or more second protrusions 340 formed in this manner are considered to constitute a second protrusion row as a whole.

[0048] The configuration of the magnetic detection module 100 is the same as that of the magnetic detection module 100 in the first embodiment. In the magnetic detection system 20 configured in this manner, the first sensor 161 and the second sensor 162 detect the first convex portions 330 passing through the first slit 141, and the third sensor 170 detects the second convex portions 340 passing through the second slit 142. More specifically, the first sensor 161 and the second sensor 162 detect the displacement of the linear moving body 300 by detecting the first convex portions 330 arranged at regular intervals, and the third sensor 170 detects the reference position of the linear moving body 300 by detecting the second convex portions 340. The signal processing circuit can calculate the absolute position of the linear moving body 300 from these detection results.

[0049] The first and second embodiments described above can be modified in various ways. For example, each convex portion is not limited to being formed by bending a plate-shaped member. It may be formed separately from the base portion, which is a disk or a flat plate, and then attached to the base portion. Alternatively, the base portion may be divided into a first base portion having a first convex ridge and a second base portion having a second convex ridge, and these may be positioned relative to each other and attached to a driven object such as the rotating shaft 910 or the reciprocating slider 920. In this case, the base portion does not need to be made of a soft magnetic material. Furthermore, the magnetic sensor does not need to be a Hall IC; for example, an MR element may be used. In this case, the magnetization direction of the magnet can be changed depending on the magnetic sensor used.

[0050] In the first and second embodiments described above, the second convex row is made up of one second convex portion, but if multiple reference positions to be detected are set, the number of second convex portions can be increased accordingly. Also, while the first convex row is arranged on the edge and the second convex row is arranged inside the base of the movable body, these arrangements may be reversed.

[0051] In the first and second embodiments described above, the first detection unit 160 is configured with two sensors (first sensor 161 and second sensor 162). However, in cases where it is not necessary to detect the moving direction of the moving object, the first detection unit 160 may be configured with a single sensor. In such cases, as in the first and second embodiments, it is preferable that the first detection unit, the magnet, and the second detection unit are arranged along a direction perpendicular to the moving direction of the moving object. Note that "perpendicular" here does not have to mean strictly 90°, but rather may be within a range in which the first detection unit and the second detection unit can detect the magnetism of the magnet, as described above. Arranged in this manner, the magnetic detection device and the magnetic detection module including the same can be configured compactly. Here, "arranged along a single direction" does not necessarily mean aligned in a straight line, but may be aligned along a single imaginary line as a whole, to the extent that the magnetic detection device and the magnetic detection module including the same can be configured compactly.

[0052] Furthermore, the magnetic detection systems 10 and 20 in the first and second embodiments described above are particularly effective when incorporated into gear-driven detection devices and motor-driven detection devices. Devices driven by gears or motors are often used in environments where dust and oil are present, but compared to contact-type or optical detection devices, measurement results are less susceptible to such environments. They are also suitable for incorporation into encoders, which are often used in such environments. [Explanation of symbols]

[0053] 10, 20...magnetic detection system, 100...magnetic detection module, 110...housing, 120...mounting portion, 130...connector insertion port, 141...first slit, 142...second slit, 150...magnet, 151...yoke, 151a...opening, 160...first detection portion, 161...first sensor, 162...second sensor, 170...second detection portion (third sensor), 200...rotating body, 210...disk portion, 220...joint portion, 230...first convex portion, 240...second convex portion, 300...linear body, 310...flat portion, 320...joint portion, 330...first convex portion, 340...second convex portion, 910...rotating shaft, 920...reciprocating slider

Claims

1. a first detector, a magnet, and a second detector arranged in this order along one direction; the first detection unit detects a change in magnetism from the magnet that occurs when a first convex row consisting of at least one convex portion provided on the moving body passes between the first detection unit and the magnet as the moving body moves, The second detection unit is a magnetic detection device that detects changes in the magnetic field from the magnet that occur when a second convex row consisting of at least one convex portion provided on the moving body passes between the magnet and the second detection unit as the moving body moves.

2. The magnetic detection device according to claim 1 , wherein the first detection unit includes at least two magnetic sensors arranged along the direction of movement of the moving body.

3. The magnetic detection device according to claim 1 , wherein the magnet has a yoke on either a first surface side facing the first detection unit or a second surface side facing the second detection unit.

4. 4. The magnetic detection device according to claim 3, wherein the yoke has an opening through which the magnetic field of the magnet passes.

5. 2. The magnetic detection device according to claim 1, wherein the magnetization direction of the magnet is parallel to the one direction.

6. the number of the convex portions constituting the second convex row is smaller than the number of the convex portions constituting the first convex row, the first detection unit outputs a change in the magnetic field from the magnet as an analog signal; The second detection unit outputs a change in the magnetism from the magnet as a digital signal. The magnetic detection device according to claim 1 .

7. The magnetic detection device according to any one of claims 1 to 6, a base portion that positions the first detection portion, the magnet, and the second detection portion; A magnetic detection module comprising:

8. The magnetic detection device according to any one of claims 1 to 6, The moving body A magnetic detection system comprising:

9. 9. The magnetic detection system according to claim 8, wherein the ratio of the width of the convex portion to the spacing between two adjacent convex portions constituting the first convex row in the direction of movement of the moving body is 8% or more and 40% or less.

10. the moving body is a rotating body having a rotation center on a straight line along the one direction, The magnetic detection system according to claim 8 , wherein the magnetic detection device detects a rotation angle of the rotating body.

11. the moving body is a linear moving body that moves along a straight line perpendicular to the one direction, The magnetic detection system according to claim 8 , wherein the magnetic detection device detects the position of the linear moving body.

12. A gear drive sensing device comprising the magnetic detection system of claim 8.

13. A motor drive sensing device comprising the magnetic detection system according to claim 8.

14. An encoder comprising the magnetic detection system according to claim 8.

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