JP2016114425A - Location detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a location detection device that can ensure flexibility in the number of windings of exciting coils when installing plural systems of exciting coils.SOLUTION: A location detection device 1 detects a rotational location of a detected part according to a detection signal output from a detection coil due to mutual induction with an exciting coil 3 at a magnetic field. When installing a plurality (plural systems) of exciting coils 3 on the location detection device 1, each exciting coil 3 designed to be a folded shape over a first layer 6a and a second layer 6b of a substrate 6 is arranged in a rotational direction of the detected part (an arrow R direction) after being rotated for a specified amount.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a position detection device that detects a rotational position of a detected portion.

  Conventionally, position detection that calculates the position of a detected part (movable object) by applying a magnetic field to a plurality of detection coils from an excitation coil and detecting a change in the magnetic field applied to the detection coil according to the rotation of the metal rotor. An apparatus (eddy current sensor) is well known (see Patent Document 1). In this type of position detection device, the excitation coil and the detection coil are electromagnetically coupled, and the induced electromotive force appearing in the detection coil changes according to the rotational position of the metal rotor, so that the detected portion is detected from the change in the induced electromotive force. A rotational position is detected.

JP 2002-365006 A

  By the way, as a countermeasure against the malfunction of the excitation coil, it has been studied to provide a plurality of excitation coils, that is, to have a plurality of systems. In this way, even if the excitation coil of a certain system becomes defective, the magnetic field is applied to the detection coil by the excitation coil of another normal system, so that the position can be continuously detected. However, in this case, there is a problem that the degree of freedom of the number of turns of the exciting coil is limited because the exciting coil has to be wound in a limited space of the substrate.

  An object of the present invention is to provide a position detection device capable of ensuring the degree of freedom of the number of turns of an exciting coil even when a plurality of exciting coils are provided.

  A position detection device that solves the above problems includes a plurality of excitation coils that are excited by flowing current, a plurality of detection coils that can detect a magnetic field output from the excitation coil, and a position detection target. A metal part that changes a magnetic field applied to the detection coil in accordance with a rotation position of the movable detection part, and detects a rotation position of the detection part based on a detection signal of the detection coil. In the configuration, the plurality of excitation coils are arranged in a ring shape along the rotation direction of the metal part, and the windings of the excitation coils are formed to be folded over the first layer and the second layer of the substrate. , It is arranged so that a part of it overlaps with the adjacent one.

  According to this configuration, when a plurality of (a plurality of systems) excitation coils are provided in the position detection device, the shape of each excitation coil is a folded shape extending over the first layer and the second layer of the substrate. In addition, it is arranged to rotate by a specified amount in the rotation direction of the detected part. For this reason, when providing a plurality of (a plurality of systems) excitation coils, the winding pattern is formed using both the first layer and the second layer of the substrate, so that the degree of freedom of the number of excitation coil turns can be ensured. It becomes.

  In the position detection device, the exciting coil includes a first winding portion provided in the first layer and a second winding portion provided in the second layer, and the first winding portion and It is preferable that the length of the second winding portion in the rotation direction of the metal portion is the same. According to this configuration, it is advantageous to apply the magnetic field output from the excitation coil evenly to the detection coil.

  In the position detection device, the detection coil includes a plurality of detection loops corresponding to a range in which the rotation position of the detected part can be detected over the entire circumference of the metal part in the rotation direction. It is preferable that the first winding portion and the second winding portion are formed in a shape, and are formed at the same angle with respect to a loop angle that is a range of angles at which the detection loop is disposed. According to this configuration, since the first winding portion and the second layer winding have the same size as the detection coil, it is advantageous to efficiently apply the magnetic field of the excitation coil to the detection coil.

  In the position detection device, a plurality of the detection coils form one set, and a detection loop corresponding to a range in which the rotation position of the detected portion can be detected is shifted by a specific phase in the same set. And a plurality of position calculation units for calculating the position of the detected portion based on the detection signal of the detection coil are provided for each set of detection coils. It is preferable to calculate the rotational position of the detected portion. According to this configuration, since a plurality of sets of detection coils are provided, position calculation can be continued with a set of detection coils of another system even if the detection coil set of a certain system becomes defective. Become. Therefore, it becomes advantageous for ensuring fail-safe.

  The position detection device includes an abnormality monitoring unit that monitors the presence or absence of malfunction of the excitation coil based on the detection signals of the detection coils provided in a plurality of sets or the calculation result of the rotation position of the detected portion. Is preferred. According to this configuration, when a malfunction occurs in the exciting coil, it can be recognized by the position detection device. Therefore, it is possible to take measures to be taken when the exciting coil becomes defective.

  According to the present invention, even when a plurality of excitation coils are provided in the position detection device, the degree of freedom of the number of turns of the excitation coil can be ensured.

The block diagram of the position detection apparatus of one Embodiment. The perspective view which shows the external appearance of an exciting coil typically. The electrical block diagram of a position detection apparatus. The voltage waveform figure which shows the output change of a detection coil when a to-be-detected part rotates. The schematic diagram which shows the state which the excitation coil of a certain system fell into malfunction. Schematic which shows how to wind the excitation coil positioned conventionally.

Hereinafter, an embodiment of the position detection device will be described with reference to FIGS.
As shown in FIG. 1, the position detection device 1 detects a rotation position (rotation position) of a detection target 2 that rotates, and is used to detect an operation position of an in-vehicle device. The position detection device 1 of the present example includes a plurality of excitation coils 3 that are excited by flowing current, a plurality of detection coils 4 that can detect a magnetic field (magnetic flux) output from the excitation coil 3, and a position detection target. And a metal part 5 that changes the magnetic field applied to the detection coil 4 in accordance with the rotation position of the rotation-type detected part 2. The detected part 2 is attached with a metal part 5 (in this example, a metal rotor) and rotates integrally with the metal part 5.

  As shown in FIG. 2, the exciting coil 3 is formed in an annular shape by being arranged over the entire circumference in the rotation direction of the metal part 5 (the direction of the arrow R in FIG. 2). The exciting coil 3 includes a plurality (four in this example) of coils (hereinafter referred to as a first exciting coil 3a, a second exciting coil 3b, a third exciting coil 3c, and a fourth exciting coil 3d) that are sequentially folded in the circumferential direction. It has such an arrangement shape. This is realized by forming the first exciting coil 3a to the fourth exciting coil 3d so as to extend along both the first layer 6a and the second layer 6b of the substrate 6 of the position detecting device 1. The first layer 6 a is preferably the front surface of the substrate 6, and the second layer 6 b is preferably the back surface of the substrate 6.

  Each of the first exciting coil 3a to the fourth exciting coil 3d includes a first winding portion 7 mounted on the first layer 6a, a second winding portion 8 mounted on the second layer 6b, and a first winding. A coil shape having a through hole 9 provided in the substrate 6 so as to connect the wire portion 7 and the second winding portion 8 is formed. The first winding portion 7 and the second winding portion 8 are wired in a substantially U-shape with the through hole 9 as the root. The through hole 9 is formed to extend perpendicular to the thickness direction of the substrate 6.

  In the case of this example, the first exciting coil 3a includes a first winding portion 7a, a second winding portion 8a, and a through hole 9a, and the second exciting coil 3b includes a first winding portion 7b and a second winding portion. 8b and a through hole 9b, the third excitation coil 3c includes a first winding part 7c, a second winding part 8c and a through hole 9c, and the fourth excitation coil 3d includes a first winding part 7d and a second winding part 7d. It is assumed that a winding portion 8d and a through hole 9d are provided.

  The exciting coil 3 is arranged so that the first winding portion 7a of the first exciting coil 3a and the second winding portion 8b of the second exciting coil 3b are opposed to each other, and the first winding portion 7b of the second exciting coil 3b. And the second winding portion 8c of the third exciting coil 3c are arranged to face each other. The exciting coil 3 is arranged so that the first winding portion 7c of the third exciting coil 3c and the second winding portion 8d of the fourth exciting coil 3d are opposed to each other, and the first winding portion of the fourth exciting coil 3d. 7d and the second winding portion 8a of the first exciting coil 3a are arranged to face each other.

  Returning to FIG. 1, the detection coil 4 is formed in an annular shape by being arranged over the entire circumference in the rotation direction of the metal part 5 (in the direction of arrow R in FIG. 1). A total of 12 detection coils 4 of this example are provided by providing a total of 4 sets of three coil groups. In the example of FIG. 1, only three of a certain set of detection coils 4 are illustrated, and each of them is referred to as a first detection coil 4a, a second detection coil 4b, and a third detection coil 4c.

  Each of the detection coils 4 has a coil shape in which a plurality (five in this example) of detection loops 10 in which the output of the detection coil 4 has one cycle are arranged in the rotation direction of the metal part 5 (the direction of arrow R in FIG. 1). I am doing. Each of the detection loops 10 is a unit coil formed in a shape in which the wiring is formed in an approximately eight-letter shape. For example, the loop angle θk is set to “72 °”. When one detection coil 4 is used as a reference coil, the other set of three detection coils 4 in the same set is arranged at a position that is different in phase by “24 °” from the reference coil, and the other is used as a reference coil. On the other hand, the phase is arranged at a position different by “48 °”. Note that the three detection coils 4 in the same group and the detection coils 4 in each group may be provided on the same substrate or different substrates. Moreover, the exciting coil 3 and the detection coil 4 may be provided on the same board | substrate, and may be provided in a different board | substrate.

  On the outer periphery of the metal part 5, a plurality of projecting pieces 5b projecting radially outward from the rotor body 5a are formed. The plurality of protruding pieces 5b are arranged at equal intervals in the rotation direction of the metal part 5 (the direction of the arrow R in FIG. 1). On the outer periphery of the metal part 5, a gap part 5 c is formed between the adjacent protruding pieces 5 b, and the protruding pieces 5 b and the gap parts 5 c are alternately arranged at equal intervals in the rotation direction of the metal part 5. The protruding piece 5b is formed in a substantially fan shape, for example. The arrangement angle θ1 of the projecting piece 5b and the arrangement angle θ2 of the gap 5c are formed to be a value half the loop angle θk (“36 °”). The metal part 5 rotates around the same axis P as the detected part 2.

  As shown in FIG. 2, the loop angle θa of the first winding portion 7 and the loop angle θb of the second winding portion 8 of the exciting coil 3 are both the same value as the loop angle θk of the detection coil 4 (in this example, 72 °). That is, in each of the first exciting coil 3a to the fourth exciting coil 3d, the loop angle θa of the first winding portion 7 and the loop angle θb of the second winding portion 8 are the loop angle θk of the detection coil 4 and Are set the same. The interval between the first excitation coil 3a to the fourth excitation coil 3d is set to “18 °” so that the first excitation coil 3a to the fourth excitation coil 3d are evenly arranged in the circumferential direction.

  As shown in FIG. 3, the position detection device 1 includes a position calculation unit 11 that calculates the rotation position of the detected unit 2 based on the detection signal S <b> 1 of the detection coil 4. A plurality (four in this example) of position calculation units 11 in this example are provided for each set of detection coils 4. Specifically, the first position calculation unit 11a is connected to the first detection coil 4a, the second detection coil 4b, and the third detection coil 4c via the detection circuit 12a. The second position calculation unit 11b is connected to the fourth detection coil 4d, the fifth detection coil 4e, and the sixth detection coil 4f via the detection circuit 12b. The third position calculation unit 11c is connected to the seventh detection coil 4g, the eighth detection coil 4h, and the ninth detection coil 4i via the detection circuit 12c. The fourth position calculation unit 11d is connected to the tenth detection coil 4j, the eleventh detection coil 4k, and the twelfth detection coil 4l via the detection circuit 12d.

  The first excitation coil 3a is excited by an AC voltage input from the oscillation circuit 13a via the excitation circuit 14a and generates a magnetic field applied to the detection coil 4. The second excitation coil 3b is excited by an AC voltage input from the oscillation circuit 13b via the excitation circuit 14b and generates a magnetic field applied to the detection coil 4. The third excitation coil 3c is excited by an AC voltage input from the oscillation circuit 13c via the excitation circuit 14c and generates a magnetic field applied to the detection coil 4. The fourth excitation coil is excited by an AC voltage input from the oscillation circuit 13d via the excitation circuit 14d, and generates a magnetic field applied to the detection coil 4.

  The position detection device 1 includes an abnormality monitoring unit 25 that monitors an abnormality related to the operation of the position detection device 1. The abnormality monitoring unit 25 of this example monitors the presence / absence of an abnormality in the position detection device 1 based on the detection signal S1 input from a plurality of detection coils 4 provided. The abnormality monitoring unit 25 of the present example monitors the abnormality of the first excitation coil 3a to the fourth excitation coil 3d, and then executes a process according to the abnormality mode.

Next, operation | movement of the position detection apparatus 1 is demonstrated using FIGS.
[Position detection during normal operation]
As shown in FIG. 4, the position detection of a specific set of three detection coils (here, the first detection coil 4a to the third detection coil 4c) will be described. When an AC voltage is applied to the first excitation coil 3a to the fourth excitation coil 3d, an induced electromotive force is generated in the first detection coil 4a to the third detection coil 4c by the mutual induction action. In this state, when the metal part 5 rotates around the axis P of the rotation center, detection is output from the first detection coil 4a to the third detection coil 4c according to the position of the protruding piece 5b of the metal part 5. The voltage (amplitude) changes to an alternating wave (for example, a sine wave or a triangular wave). That is, when the first detection signal S1-a output from the first detection coil 4a is used as a reference, the second detection coil 4b has a phase delayed by “24 °” from the first detection signal S1-a. 2 detection signal S1-b is output, and a third detection signal S1-c with a phase delayed by “48 °” from the first detection signal S1-a is output from the third detection coil 4c.

  The first position calculation unit 11a uses the first detection signal S1-a to the third detection signal S1-c that have a signal waveform in a linear (substantially linear) region (exist in the region U). Two are selected, for example, the difference or sum of these signals is calculated, and the detection angle θr corresponding to the rotational position of the detected portion 2 is calculated. That is, when the rotor angle (the rotation angle of the metal part 7) is 0 ° to 6 °, the second detection signal S1-b and the third detection signal S1-c are used, and the rotor angle is 6 ° to 18 °. In this case, the first detection signal S1-a and the second detection signal S1-b are used. When the rotor angle is 18 ° to 30 °, the first detection signal S1-a and the third detection signal S1-c Is used. In this way, the first position calculation unit 11a calculates the detection angle θr in which one cycle is 72 °.

  When the metal part 5 is rotated, a set of the fourth detection coil 4d to the sixth detection coil 4f, a set of the seventh detection coil 4g to the ninth detection coil 4i, and a set of the tenth detection coil j to the twelfth detection coil 4l are also included. The detection signal S1 having the same waveform change as the set of the first detection coil 4a to the third detection coil 4c is output. Therefore, similarly to the first detection coil 4a to the third detection coil 4c, the set of the fourth detection coil 4d to the sixth detection coil 4f, the set of the seventh detection coil 4g to the ninth detection coil 4i, and the tenth detection. Even in the set of the coil 4j to the twelfth detection coil 4l, an angle calculation of one cycle of 72 ° is executed.

  Specifically, the second position calculation unit 11b includes the fourth detection signal S1-d, the fifth detection signal S1-e, and the sixth detection signal S1-f input from the fourth detection coil 4d to the sixth detection coil. Based on this, the detection angle θr is calculated. The third position calculation unit 11c detects the detection angle based on the seventh detection signal S1-g, the eighth detection signal S1-h, and the ninth detection signal S1-i input from the seventh detection coil 4g to the ninth detection coil 4i. θr is calculated. The fourth position calculation unit 11d detects the detection angle based on the tenth detection signal S1-j, the eleventh detection signal S1-k, and the twelfth detection signal S1-l input from the tenth detection coil 4j to the twelfth detection coil 4l. θr is calculated.

  The position detection device 1 detects the rotational position of the detected part 2 based on the calculation results of the first position calculation unit 11a to the fourth position calculation unit 11d. Specifically, the position detection device 1 uses the specific one of the four calculation results of the first position calculation unit 11a to the fourth position calculation unit 11d to turn the detected position 2 (rotation angle). ) Is calculated.

  The abnormality monitoring unit 25 sequentially monitors whether or not an abnormality has occurred in the first excitation coil 3a to the fourth excitation coil 3d based on the detection signal S1 input from the plurality of detection coils 4 provided. Specifically, it is monitored whether or not the detection signal S1 takes a value within a specified range for a specific one or a set of the plurality of detection coils 4 present. Here, since the normal operation of the position detection device 1 is assumed, the detection signal S1 (amplitude) takes a normal value. That is, the abnormality monitoring unit 25 confirms that the detection signal S1 is within the specified range, and determines that there is no abnormality in the first excitation coil 3a to the fourth excitation coil 3d. Thereby, the position detection apparatus 1 performs angle calculation of the to-be-detected part 2 by normal operation | movement.

[Position detection operation in case of abnormality]
FIG. 5 illustrates an example in which one of the four excitation coils 3 (an example is the first excitation coil 3a) has stopped operating (an example is an open failure). By the way, the detection coil 4 (the first detection coil 4a to the twelfth detection coil 4l) is output even if one or a plurality of the first excitation coil 3a to the fourth excitation coil 3d is stopped. The output ratio is arranged so as not to change. For this reason, even if the output of one exciting coil 3 is stopped due to an open failure or the like, it is possible to obtain the same angle calculation result before and after the failure. Therefore, even if one exciting coil 3 fails, the angle calculation can be continued.

  By the way, when a plurality (for example, two or three) of the first excitation coil 3a to the fourth excitation coil 3d fails, the output ratio of the detection coil 4 (first detection coil 4a to twelfth detection coil 4l) does not change. Since the magnetic field of the exciting coil 3 is significantly reduced, the output value of each of the detection coils 4 is lowered by a certain amount and deviates from the specified range. Therefore, when the abnormality monitoring unit 25 detects that the detection signal (detection voltage) S1 of the detection coil 4 has become equal to or less than the specified value (threshold value), the abnormality monitoring unit 25 may notify that fact. Examples of the notification include “warning” on the vehicle side and “emergency stop of the vehicle”.

[Degree of freedom of number of excitation coil turns]
FIG. 6 illustrates how to wind the excitation coil 3 positioned conventionally. The conventionally positioned exciting coil 3 has a circular winding shape and the same number of turns in each system. In the case of this winding pattern, the exciting coil 3 has to be two systems because of the arrangement space of the substrate 6. Specifically, the first coil 6 is wound around the first layer 6a and the second layer 6b is wound around twice as the first excitation coil 3, and the second layer 6a is wound around the first layer 6a. The coil 6 wound around the layer 6b is referred to as a second excitation coil 3. Thus, in the conventional position detection device 1, the degree of freedom of the number of turns of the exciting coil 3 is not high.

  On the other hand, in the case of this example, the excitation coils 3 (the first excitation coil 3a to the fourth excitation coil 3d) of each system have a shape that folds over the first layer 6a and the second layer 6b while being substantially arc-shaped. Are arranged so as to overlap in order in the rotation direction of the detected portion 2. For this reason, in this example, each system of the exciting coil 3 (the first exciting coil 3a to the fourth exciting coil 3d) is half-turned, and the total number of windings is two while realizing the four systems of the exciting coil 3. It becomes possible. Thus, if the winding pattern of the exciting coil 3 of this example is employed, the degree of freedom of the number of turns of the exciting coil 3 can be ensured.

According to the configuration of the present embodiment, the following effects can be obtained.
(1) When a plurality of (a plurality of systems) excitation coils 3 are provided in the position detection device 1, the shape of each excitation coil 3 is a folded shape extending over the first layer 6a and the second layer 6b of the substrate 6, and this shape. The coil was rotated by a specified amount in the direction of rotation of the detected portion 2 (the direction of arrow R in FIG. 1). For this reason, when providing a plurality (ex. A plurality of systems) of exciting coils 3, a winding pattern is formed using both the first layer 6a and the second layer 6b of the substrate 6, so that the degree of freedom of winding of the exciting coil 3 is increased. Can be secured.

  (2) The exciting coil 3 includes a first winding portion 7 provided on the first layer 6 a of the substrate 6 and a second winding portion 8 provided on the second layer 6 b of the substrate 6. The first winding portion 7 and the second winding portion 8 are formed to have the same length (loop angle θk: 72 °) in the rotation direction of the metal portion 5 (detected portion 2). Therefore, it is advantageous to apply the magnetic field output from the excitation coil 3 equally to the detection coil 4.

  (3) The detection coil 4 includes a plurality of substantially eight-shaped detection loops 10 corresponding to an angular range detectable by itself over the entire circumference of the metal part 5 (detected part 2) in the rotational direction. It is formed in a different shape. The first winding portion 7 and the second winding portion 8 are formed at the same angle (72 ° in this example) as the loop angle θk of the detection coil 4. Therefore, since the setting angles of the first winding part 7 and the second winding part 8 are made to coincide with the detection loop 10, it is advantageous to apply the magnetic field of the excitation coil 3 to the detection coil 4 efficiently.

  (4) A plurality (three in this example) of detection coils 4 form one set, and the detection loop 10 is arranged with a specific phase (24 ° in this example) shifted by one in the same set, This example has 4 sets). A plurality of position calculation units 11 are provided for each set of detection coils 4, and each position calculation unit 11 calculates the rotation position of the detected unit 2. For this reason, even if a set of detection coils 4 of a certain system becomes defective in operation, position calculation can be continued with a set of detection coils 4 of another system. Therefore, it becomes advantageous for ensuring fail-safe.

  (5) The position detection device 1 is provided with an abnormality monitoring unit 25 that can determine whether the exciting coil 3 is malfunctioning. For this reason, when a malfunction occurs in the exciting coil 3, it can be recognized by the position detection device 1. Therefore, it is possible to accurately execute the actions to be taken when the exciting coil 3 becomes defective, such as an error notification or an emergency stop of the vehicle.

Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
The abnormality monitoring unit 25 may determine the presence or absence of malfunction of the exciting coil 3 from the calculation results of the first position calculation unit 11a to the fourth position calculation unit 11d. Specifically, it may be determined that an operation failure has occurred in a certain excitation coil 3 when the calculation result is different from a predetermined value.

  The abnormality monitoring unit 25 is not limited to the operation of monitoring the malfunction of the exciting coil 3. For example, when the detection coil 4 falls into a malfunction, the output of the detection coil 4 takes a value different from the normal value. Therefore, this is monitored by the abnormality monitoring unit 25 to determine whether the detection coil 4 is malfunctioning. You may judge.

The detection coils 4 are not limited to having the same phase position in each set, and may be arranged with a predetermined amount shifted in the rotation direction of the detected portion 2.
-Only one set of the detection coils 4 may be formed.

The detection coil 4 is not limited to the shape of the detection loop 10 having a substantially eight-letter shape, and can be appropriately changed to other shapes.
The number of detection coils 4 per set is not limited to three, and can be changed to other values.

The number of exciting coils 3 is not limited to four, and can be changed to other numbers.
The exciting coils 3 are not limited to be evenly (equally spaced) in the circumferential direction of the metal part 5 and may be non-uniformly arranged.

-The shape of the 1st coil part 7 and the 2nd coil part 8 can be changed into other shapes, such as the shape which has a curve, for example.
The first winding part 7 and the second winding part 8 may be formed at a setting angle different from the loop angle θk of the detection coil 4.

The shape and setting angle may be changed between the first winding portion 7 and the second winding portion 8.
-The overlapping range of the 1st coil part 7 and the 2nd coil part 8 can be changed freely suitably.

The metal part 5 is not limited to a shape having a protruding piece protruding outward in the radial direction, and can be changed to another shape such as a shape in which a hole is formed in a predetermined portion of a flat metal plate.
The substrate 6 may be a multilayer substrate.

The coil group may be attached to the movable side, and the metal part 5 may be attached to the fixed side.
The first excitation coil 3a is connected to the first position calculation unit 11a, the second excitation coil 3b is connected to the second position calculation unit 11b, the third excitation coil 3c is connected to the third position calculation unit 11c, The operation of each excitation coil 3 may be managed by the corresponding position calculation unit 11 by connecting the four excitation coils 3d to the fourth position calculation unit 11d.

The position detection device 1 can be applied to various devices and apparatuses.
Next, technical ideas that can be grasped from the above-described embodiment and other examples will be described below together with their effects.

  (A) In the position detection device, the position calculation unit calculates the position using an output of a linear region in the detection signal input from the detection coil. According to this configuration, it is advantageous to calculate the rotation position of the detected portion more correctly.

  (B) In the position detection device, the plurality of detection coils are arranged so as to partially overlap each other. This configuration is advantageous for reducing the size of the apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Position detection apparatus, 2 ... Detected part, 3 ... Excitation coil, 3a ... 1st excitation coil, 3b ... 2nd excitation coil, 3c ... 3rd excitation coil, 3d ... 4th excitation coil, 4 (4a-4l) ) ... detection coil, 5 ... metal part, 6 ... substrate, 6a ... first layer, 6b ... second layer, 7 (7a-7d) ... first winding part, 8 (8a-8d) ... second winding , 10 ... detection loop, 11 (11a to 11d) ... position calculation part, 25 ... abnormality monitoring part, S1 (S1-a to S1-l) ... detection signal, R ... rotation direction, P ... axis, θk ... loop angle.

Claims (5)

A plurality of exciting coils that are excited by passing a current, a plurality of detecting coils that can detect a magnetic field output from the exciting coil, and a rotational position of a rotational detection target that is a position detection target And a metal part that changes a magnetic field applied to the detection coil according to a position detection device that detects a rotation position of the detected part based on a detection signal of the detection coil.
The plurality of exciting coils are arranged in a ring shape along the rotation direction of the metal part, and the winding of the exciting coil is formed to be folded over the first layer and the second layer of the substrate. A position detection device, wherein the position detection device is arranged so that a part thereof overlaps with a position. The exciting coil includes a first winding portion provided in the first layer and a second winding portion provided in the second layer,
The position detection device according to claim 1, wherein the first winding portion and the second winding portion are formed to have the same length in the rotation direction of the metal portion. The detection coil is formed in a shape in which a plurality of detection loops corresponding to a range in which the rotation position of the detected part can be detected are arranged over the entire circumference of the rotation direction of the metal part,
The said 1st winding part and the 2nd winding part are formed in the same angle as this with respect to the loop angle which is the range of the angle by which the said detection loop was arrange | positioned. The position detection device described. A plurality of the detection coils form one set, and in the same set, detection loops corresponding to a range in which the rotation position of the detected part can be detected are shifted by a specific phase, and a plurality of the detection coils are arranged. Has
A plurality of position calculation units for calculating the position of the detected portion based on the detection signal of the detection coil are provided for each set of the detection coils, thereby calculating the rotational position of the detected portion for each set. The position detection apparatus according to claim 1, wherein the position detection apparatus is a position detection apparatus. An abnormality monitoring unit for monitoring the presence or absence of malfunction of the exciting coil based on a detection signal of the detection coil provided in a plurality of sets or a calculation result of a rotation position of the detected portion. Item 5. The position detection device according to any one of Items 1 to 4.