JP2016011894A - Rotation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation detection device capable of making an area to install a detection coil smaller than 360° while detecting a rotating operation for at least one rotation.SOLUTION: A rotation detection device 1 includes: a rotation member 10; an exciting coil 11 for generating an alternating magnetic field 110; a detection coil group 16 formed from detection coils disposed within an arrangement area 111 surrounded by the exciting coil 11 and along a part of a circumference of a concentric circle around an intersection 115 of a rotary shaft 100 and a substrate 3; a first alternating magnetic field change section which is disposed in a radial direction of the rotation member 10, has a shape opposite to the plurality of detection coils in the detection coil group 16 and changes the alternating magnetic field 110 acting on the plurality of detection coils at the opposite side; and a second alternating magnetic field change section which is disposed in a radial direction of the rotation member 10 different from the first alternating magnetic field change section, has a shape opposite to one detection coil in the detection coil group 16 and changes the alternating magnetic field 110 acting on the one detection coil at the opposite side.

Description

  The present invention relates to a rotation detection device.

  As a conventional technique, an excitation winding for forming an excitation magnetic field, at least one secondary winding in which a voltage is induced in the presence of the excitation magnetic field, and an internal structure in the presence of the excitation magnetic field There is known a sensor including at least one screen that generates an eddy current and forms a counter magnetic field opposite to an excitation magnetic field (see, for example, Patent Document 1).

  In this sensor, the excitation winding is configured as two annular windings on a disk, the secondary winding is configured in the form of a plane extending radially between the two excitation windings, and a screen is provided. It is configured as a fan-shaped part of the rotor. The screen and the secondary winding are configured to be relatively rotationally moved within the excitation magnetic field. Thus, the sensor can change the voltage induced in the secondary winding based on the rotational movement of the rotor, with the secondary winding being shielded by the screen.

JP-A 61-159101

  However, the conventional sensor requires, for example, an excitation winding and a secondary winding for one rotation, that is, 360 °, in order to detect the rotational movement of one rotation of the rotor, and it is difficult to reduce the size. Met.

  Accordingly, an object of the present invention is to provide a rotation detection device that can detect a rotation operation for at least one rotation, but can make an area where a detection coil is installed smaller than 360 °.

  One embodiment of the present invention is surrounded by a rotating member that rotates around a rotating shaft, an excitation coil that is disposed on a base that faces the rotating member, and that generates an alternating magnetic field based on a supplied AC signal, and the exciting coil. A detection coil group consisting of detection coils arranged along a part of each circumference of a concentric circle centering on the intersection of the rotating shaft and the base body, and arranged in the radial direction of the rotating member A first alternating magnetic field changing unit that has a shape facing a plurality of detection coils of the coil group and changes an alternating magnetic field that acts on the plurality of opposing detection coils, and a first alternating magnetic field changing unit of the rotating member A second alternating magnetic field changing unit that is arranged in different radial directions, has a shape facing one detection coil of the detection coil group, and changes an alternating magnetic field acting on one opposing detection coil; Providing detection equipment That.

  According to the present invention, the region where the detection coil is installed can be made smaller than 360 ° while the rotation operation for at least one rotation can be detected.

FIG. 1A is a schematic diagram of the inside of a vehicle on which the rotation detection device according to the first embodiment is mounted, and FIG. 1B is an enlarged view of the periphery where the rotation detection device is arranged. . FIG. 2A is a perspective view of the rotation detection device according to the first embodiment, and FIG. 2B is a rear view of the rotation member for explaining the arrangement of the metal members. FIG. 3A is a schematic diagram for explaining the arrangement of the excitation coil and the detection coil of the rotation detection device according to the first embodiment, and FIG. 3B is an alternating current supplied to the excitation coil. It is a graph of a signal. FIG. 4A is a block diagram of the rotation detection device according to the first embodiment, and FIG. 4B is a diagram for explaining the connection between the rotation detection device and a vehicle LAN (Local Area Network). FIG. FIG. 5A is a top view for explaining relative movement between the detection coil and the first metal member of the rotation detection device according to the first embodiment, and FIG. 5B is a detection coil. FIG. 5C is a top view for explaining the relative movement between the detection coil and the third metal member. FIG. 6A is a top view for explaining relative movement between the detection coil and the fourth metal member of the rotation detection device according to the first embodiment, and FIG. 6B is a detection coil. FIG. 6C is a top view for explaining the relative movement between the detection coil and the sixth metal member. FIG. 7A is a top view for explaining relative movement between the detection coil and the seventh metal member of the rotation detection device according to the first embodiment, and FIG. 7B is a detection coil. FIG. 7C is a top view for explaining the relative movement between the first metal member and the eighth metal member. FIG. 7C is a top view for explaining the positional relationship between the detection coil, the second metal member, and the third metal member. FIG. FIG. 8A is a graph of a detection signal output from the first detection coil pair of the rotation detection device according to the first embodiment, and FIG. 8B is a graph from the second detection coil pair. FIG. 8C is a graph of the detection signal output, FIG. 8C is a graph of the detection signal output from the third detection coil pair, and FIG. 8D is output from the fourth detection coil pair. It is a graph of a detection signal. FIG. 9 is a rear view of the rotating member for explaining the arrangement of the metal members of the rotation detecting device according to the second embodiment. FIG. 10A is a graph of a detection signal output from the first detection coil pair of the rotation detection device according to the second embodiment, and FIG. 10B is a graph from the second detection coil pair. FIG. 10C is a graph of the detection signal output from the third detection coil pair, and FIG. 10D is a graph of the detection signal output from the fourth detection coil pair. It is a graph of a detection signal.

(Summary of embodiment)
A rotation detection device according to an embodiment includes a rotation member that rotates around a rotation axis, an excitation coil that is disposed on a base that faces the rotation member, and generates an alternating magnetic field based on a supplied AC signal, and an excitation coil A detection coil group consisting of detection coils arranged along a part of each circumference of a concentric circle centered on the intersection of the rotation axis and the base body, and arranged in the radial direction of the rotary member A first alternating magnetic field changing unit that has a shape facing the plurality of detection coils of the detection coil group and changes the alternating magnetic field acting on the plurality of opposing detection coils, and a first alternating magnetic field change of the rotating member A second alternating magnetic field changing unit that is arranged in a radial direction different from the part, has a shape facing one detection coil of the detection coil group, and changes an alternating magnetic field acting on one opposing detection coil, In preparation It has been made.

[First embodiment]
(Overall configuration of rotation detection device 1)
FIG. 1A is a schematic diagram of the inside of a vehicle on which the rotation detection device according to the first embodiment is mounted, and FIG. 1B is an enlarged view of the periphery where the rotation detection device is arranged. . FIG. 2A is a perspective view of the rotation detection device according to the first embodiment, and FIG. 2B is a rear view of the rotation member for explaining the arrangement of the metal members. FIG. 3A is a schematic diagram for explaining the arrangement of the excitation coil and the detection coil of the rotation detection device according to the first embodiment, and FIG. 3B is an alternating current supplied to the excitation coil. It is a graph of a signal. FIG. 4A is a block diagram of the rotation detection device according to the first embodiment, and FIG. 4B is a schematic diagram for explaining the connection between the rotation detection device and the vehicle LAN. Note that, in each drawing according to the embodiment described below, the ratio between figures may be different from the actual ratio. In FIGS. 4A and 4B, the flow of main signals and information is indicated by arrows.

  For example, the rotation detection device 1 is configured to be able to operate electronic devices such as an air conditioner and a car navigation device mounted on the vehicle 5. The rotation detection device 1 according to the present embodiment will be described, for example, when an air conditioner is selected as an operation target.

  The rotation detection device 1 is, for example, a display device 6 disposed on a center console 50 located in front of a driver seat and a passenger seat of the vehicle 5 on the paper surface of FIGS. 1 (a) and 1 (b). Located on the lower side.

  On the display screen 60 of the display device 6, as shown in FIG. 1B, a display image 61 that can confirm the operation status of the air conditioner is displayed. The operator picks the knob 102 of the rotation detection device 1 with the hand 9 and rotates the hand 9 counterclockwise (arrow A direction) and clockwise (arrow B direction) in FIG. It is possible to change the setting value of the selected function.

As shown in FIGS. 2A and 2B, the rotation detection device 1 is arranged and supplied to a rotating member 10 that rotates around a rotating shaft 100 and a base 3 that faces the rotating member 10. An excitation coil 11 that generates an alternating magnetic field 110 based on the AC signal S ₁ , and a concentric circle that is in a region (arrangement region 111) surrounded by the excitation coil 11 and that has an intersection 115 between the rotating shaft 100 and the base 3. A detection coil group 16 composed of detection coils arranged along a part of the circumference of each of the first circle 116 to the fourth circle 119, and a radial arrangement of the rotating member 10, and the detection coil group 16 A first alternating magnetic field changing unit to be described later for changing an alternating magnetic field 110 acting on the plurality of opposing detecting coils, and a first alternating magnetic field changing unit of the rotating member 10. Different radial direction And a second alternating magnetic field changing unit (described later) that changes the alternating magnetic field 110 acting on one opposing detection coil and having a shape facing one detection coil of the detection coil group 16. It is roughly structured.

  The above-described detection coils are, for example, the first detection coil 12a, the third detection coil 13a, the fifth detection coil 14a, and the seventh detection coil 15a indicated by solid lines in FIG.

  In addition, the rotation detection device 1 is provided on the base 3 in such a manner that the detection coils that are paired with the detection coils are stacked while maintaining insulation. As an example, the pair of detection coils are a second detection coil 12b, a fourth detection coil 13b, a sixth detection coil 14b, and an eighth detection coil 15b indicated by dotted lines in FIG.

  In the present embodiment, the first detection coil 12a and the second detection coil 12b are used as the first detection coil pair 12, and the third detection coil 13a and the fourth detection coil 13b are used as the second detection coil pair. 13. The fifth detection coil 14a and the sixth detection coil 14b are the third detection coil pair 14, and the seventh detection coil 15a and the eighth detection coil 15b are the fourth detection coil pair 15. . The detection coil group 16 includes a first detection coil pair 12 to a fourth detection coil pair 15.

  As shown in FIG. 2B, the first alternating magnetic field change unit includes, as an example, a second metal member 22, a fourth metal member 24, a sixth metal member 26, and an eighth metal member 28. is there.

  As shown in FIG. 2B, the second alternating magnetic field changing unit includes, as an example, a first metal member 21, a third metal member 23, a fifth metal member 25, and a seventh metal member 27. is there.

The rotation detection device 1 includes a detection signal S _{2 to be} described later as a first detection signal acquired from the first detection coil 12a, the third detection coil 13a, the fifth detection coil 14a, and the seventh detection coil 15a. The detection signal S ₄ , the detection signal S ₆ , the detection signal S ₈ , and the second detection coil 12b, the fourth detection coil 13b, the sixth detection coil 14b, and the second detection coil 15b acquired from the second detection coil 15b. A control unit 40 is provided as a determination unit that determines the rotation angle of the rotating member 10 based on detection signals S ₃ , detection signals S ₅ , detection signals S ₇ , and detection signals S ₉ described later as signals.

(Configuration of Rotating Member 10)
The rotating member 10 is formed using, for example, a resin. Further, as shown in FIGS. 2A and 2B, the rotating member 10 includes a base 101 having a disk shape and a knob 102 having a columnar shape. The rotating member 10 may have a configuration in which the first metal member 21 to the eighth metal member 28 are disposed on the knob 102 without the base 101.

  The base 101 is located inside the center console 50, the knob 102 is provided on the front surface 101 a, and the first metal member 21 to the eighth metal member 28 are disposed on the back surface 101 b.

  The knob 102 protrudes from the center console 50 as shown in FIGS. 1 (a) and 1 (b). The rotating member 10 is configured so that an operator can rotate the knob 102.

(Configuration of exciting coil 11)
The exciting coil 11 is formed on the base 3 using a conductive metal material. The exciting coil 11 is provided on the base 3 by printing, for example. As shown in FIG. 3A, the exciting coil 11 has a fan shape with a central angle θ ₃ centered on the intersection 115.

As an example, the central angle θ ₃ is 45 °. This central angle θ ₃ is determined based on the detection range and the number of pitches on which the metal members are arranged. In the present embodiment, as an example, the detection range is a rotation operation range of one rotation of the rotation member 10, that is, 0 ° to 360 °, and the number of metal members is eight. Therefore, the central angle θ ₃ is 45 ° obtained by dividing the detection range by the detection coil pair.

As a modification, when the detection range is 0 ° to 360 °, the central angle θ ₃ of the exciting coil 11 is changed based on the widths of the first metal member 21 to the eighth metal member 28 described later. good. For example, when the width of the first metal member 21 to the eighth metal member 28 is based on the fan-shaped center angle θ ₂ that determines the shape of the metal member, the center angle θ ₂ is subtracted from 45 °. The angle may be the central angle θ ₃ of the exciting coil 11. As an example, when the fan-shaped central angle θ ₂ is 10 °, the central angle θ ₃ of the exciting coil 11 is 35 °, and further miniaturization is possible.

  The reference position (0 °) of the range of the rotation operation is, for example, an operation position where the right side 112 of the exciting coil 11 is located at the center of the first metal member 21 on the paper surface of FIG. The range of the rotation operation ranges from this reference position to one rotation (360 °) in the direction of arrow A shown in FIG.

  The first detection coil pair 12 to the fourth detection coil pair 15 are arranged in the arrangement region 111 of the excitation coil 11. The region surrounded by the excitation coil 11 is, for example, a region surrounded by the excitation coil 11 in the top view of FIG. 3A, and the excitation coil 11 is formed in a range where the alternating magnetic field 110 acts. This is a region including the upper and lower layers.

The exciting coil 11 is, for example, as shown in FIG. 3 (b), the AC signals S ₁ which changes periodically current I is supplied. Based on the AC signal S ₁ , the exciting coil 11 changes in size and direction alternately in the normal direction of the front surface 30 of the base 3 and the normal direction of the back surface 31 as shown in FIG. An alternating magnetic field 110 is generated.

The exciting coil 11 is electrically connected to a control unit 40 of a control IC (Integrated Circuit) 4 disposed on the base 3. The excitation coil 11 is supplied with an AC signal S ₁ from the control unit 40.

(Configuration of first detection coil pair 12 to fourth detection coil pair 15)
The first detection coil pair 12 to the fourth detection coil pair 15 are formed on the base 3 using a conductive metal material. The first detection coil pair 12 to the fourth detection coil pair 15 are provided on the base 3 by printing, for example.

  The first detection coil pair 12 is disposed along a first circle 116 centering on the intersection 115 as shown by a one-dot chain line in FIG. The second detection coil pair 13 is arranged along a second circle 117 centering on the intersection 115 as shown by a one-dot chain line in FIG. The third detection coil pair 14 is arranged along a third circle 118 centering on the intersection 115 as shown by a one-dot chain line in FIG. The fourth detection coil pair 15 is arranged along a fourth circle 119 centered on the intersection 115 as shown by a one-dot chain line in FIG.

  The first detection coil pair 12 includes a first detection coil 12a and a second detection coil 12b that is provided on a different layer from the first detection coil 12a and insulated. The second detection coil pair 13 includes a third detection coil 13a and a fourth detection coil 13b that is provided on a different layer from the third detection coil 13a and insulated. The third detection coil pair 14 includes a fifth detection coil 14a and a sixth detection coil 14b that is provided in a different layer from the fifth detection coil 14a and insulated. The fourth detection coil pair 15 includes a seventh detection coil 15a and an eighth detection coil 15b that is provided on a different layer from the seventh detection coil 15a and insulated.

  The first detection coil 12a, the third detection coil 13a, the fifth detection coil 14a, and the seventh detection coil 15a indicated by solid lines in FIG. 3A are provided in the same layer, for example. The second detection coil 12b, the fourth detection coil 13b, the sixth detection coil 14b, and the eighth detection coil 15b indicated by dotted lines in FIG. 3A are provided in the same layer. The detection coil 12a, the third detection coil 13a, the fifth detection coil 14a, and the seventh detection coil 15a are provided below the layer provided.

  As for the 1st detection coil 12a-the 8th detection coil 15b, the one end part and the other end part are electrically connected to the control part 40 like the exciting coil 11 shown to Fig.3 (a). Further, in FIG. 3A, the detection coils are configured such that portions other than the end portions do not contact each other.

  The first detection coil 12 a and the paired second detection coil 12 b have different shapes and have a shape that is line symmetric with respect to an axis of symmetry passing through the intersection 115. This axis of symmetry is a straight line that becomes a fold when the exciting coil 11 is folded back so as to overlap. Similarly, the other detection coils and the pair of detection coils have different shapes and have a shape that is line-symmetric with respect to an axis of symmetry passing through the intersection 115.

  For example, as shown in FIG. 3A, the first detection coil 12a has a shape in which two first ring portions having a ring shape (the ring portion 120a and the ring portion 121a) are connected, The areas surrounded by the first ring portion are configured to be substantially equal to each other.

That is, the first detection coil 12a, for example, the detection signal S ₂ output, (see Fig. 8 to be described later (a)) that has a shape such that the sine wave for one cycle. The third detection coil 13a, the detection coil 15a of the fifth detection coil 14a and the seventh, as in the first detection coil 12a, the detection signal _{S 4} that is output, the detection signal _{S 6} and the detection signal _{S 8} Is shaped to be a sine wave for one cycle.

  In addition, as shown in FIG. 3A, for example, the second detection coil 12b as a pair includes a ring part 121b as a second ring part having a ring shape and a ring part 121b concentrically (first circle). 116) and two half-ring parts (half-ring part 120b and half-ring part 122b) that are cut in the radial direction have a shape connected around the ring part 121b. Further, the second detection coil 12b has an area of a region surrounded by the ring part 121b and an area of two regions surrounded by the half ring part, and the ring part 120a and the ring part of the corresponding first detection coil 12a. It is comprised so that it may become substantially equal to the area of 121a.

That second in the detection coil 12b is, for example, the detection signal _{S 3} output, paired first detection coil 12a and with phase shifts, the amplitude of the half-ring portion 120b and the Hanwa portion 122b is ring portion 121b The shape is smaller than the amplitude of. The fourth detection coil 13b, the detection coil 15b of the detection coil 14b and the eighth sixth, like the second detection coil 12b, the detection signal _{S 5} output the detection signal _{S 7} and the detection signal _{S 9} However, the phase is shifted from that of the pair of detection coils, and the amplitude in the half ring portion is smaller than the amplitude of the ring portion.

  Similarly, the 3rd detection coil 13a has a shape which connected the ring part 130a and the ring part 131a. The fifth detection coil 14a has such a shape that the ring part 140a and the ring part 141a are connected. The seventh detection coil 15a has such a shape that the ring part 150a and the ring part 151a are connected.

  The fourth detection coil 13b paired with the third detection coil 13a has a shape in which the half ring part 130b and the half ring part 132b are connected with the ring part 131b as the center. The sixth detection coil 14b paired with the fifth detection coil 14a has a shape in which the half ring part 140b and the half ring part 142b are connected with the ring part 141b as the center. The eighth detection coil 15b paired with the seventh detection coil 15a has a shape in which the half ring part 150b and the half ring part 152b are connected with the ring part 151b as the center.

  In addition, the part that the ring part and the ring part are connected, and the part that the ring part and the semi-ring part are connected are not connected, but are the parts that intersect vertically while the coils are insulated. is there.

For example, when the alternating magnetic field 110 acts in the normal direction of the paper surface of FIG. 3A, the first detection coil 12a generates a magnetic field that cancels the alternating magnetic field 110 in the first detection coil 12a. Current flows. Therefore, since the ring part 120a and the ring part 121a intersect, a clockwise current flows in the ring part 120a of the first detection coil 12a, and a counterclockwise current flows in the ring part 121a. Flowing. In other words, since the first detection coil 12a has substantially the same area of the ring part 120a and the ring part 121a, the ring part 120a and the ring part 121a have the same size and the opposite direction based on electromagnetic induction. A current is generated. Therefore detection signal S ₂ output from the first detection coil 12a becomes zero. The detection signal S _2, the direction of the alternating magnetic field 110 is also turned in the opposite direction, the zero of symmetry of the first detection coil 12a.

For example, when the alternating magnetic field 110 acts in the normal direction of the paper surface of FIG. 3A, the second detection coil 12b generates a magnetic field that cancels the alternating magnetic field 110 in the second detection coil 12b. Current flows. Accordingly, a clockwise current flows through the half ring portion 120b of the second detection coil 12b, a counterclockwise current flows through the ring portion 121b, and a clockwise current flows through the half ring portion 122b. . In other words, the first detection coil 12a is configured such that the area obtained by adding the area of the half ring part 120b and the area of the half ring part 122b is substantially equal to the area of the ring part 121b. ₃ is zero. The detection signal S _3, even if the direction of the alternating magnetic field 110 becomes reversed, the zero of symmetry of the second detection coil 12b.

Accordingly, when the first detection coil pair 12 is acted by the alternating magnetic field 110 in the direction normal to the paper surface of FIG. 3A and in the direction opposite to the normal direction, the metal members are not opposed to each other. the detection signal _{S 2} and the detection signal _{S 3} is zero.

Since the second detection coil pair 13 to the fourth detection coil pair 15 have a shape similar to that of the first detection coil pair 12, what is the normal direction and normal direction of the paper surface of FIG. When the alternating magnetic field 110 in the opposite direction acts, the detection signals S ₄ to S ₉ become zero when the metal members are not facing each other.

(Configuration of first metal member 21 to eighth metal member 28)
FIG. 5A is a top view for explaining relative movement between the detection coil and the first metal member of the rotation detection device according to the first embodiment, and FIG. 5B is a detection coil. FIG. 5C is a top view for explaining the relative movement between the detection coil and the third metal member.

  FIG. 6A is a top view for explaining relative movement between the detection coil and the fourth metal member of the rotation detection device according to the first embodiment, and FIG. 6B is a detection coil. FIG. 6C is a top view for explaining the relative movement between the detection coil and the sixth metal member.

  FIG. 7A is a top view for explaining relative movement between the detection coil and the seventh metal member of the rotation detection device according to the first embodiment, and FIG. 7B is a detection coil. FIG. 7C is a top view for explaining the relative movement between the first metal member and the eighth metal member. FIG. 7C is a top view for explaining the positional relationship between the detection coil, the second metal member, and the third metal member. FIG.

  FIG. 8A is a graph of a detection signal output from the first detection coil pair of the rotation detection device according to the first embodiment, and FIG. 8B is a graph from the second detection coil pair. FIG. 8C is a graph of the detection signal output, FIG. 8C is a graph of the detection signal output from the third detection coil pair, and FIG. 8D is output from the fourth detection coil pair. It is a graph of a detection signal.

8A to 8D, the vertical axis represents the voltage V of the detection signal, and the horizontal axis represents the rotation angle θ of the rotating member 10. The FIG. 8 (a), the solid line is a detection signal _{S 2} of the first detection coil 12a, a dotted line is a detection signal _{S 3} of the second detection coil 12b. FIG. 8 (b), the solid line is a detection signal _{S 4} of the third detection coil 13a, a dotted line is a detection signal _{S 5} of the fourth detection coil 13b. FIG. 8 (c), the solid line is a detection signal _{S 6} of the fifth detection coil 14a, a dotted line is a detection signal _{S 7} of the sixth detection coil 14b. FIG. 8 (d) is the solid line is a detection signal _{S 8} of the seventh detection coil 15a, a dotted line is a detection signal _{S 9} of the detection coil 15b of the eighth.

  The first metal member 21 to the eighth metal member 28 are formed in a plate shape using a metal material such as copper. The first metal member 21 to the eighth metal member 28 are disposed on the back surface 101 b of the base 101 of the rotating member 10.

  As shown in FIG. 2B, the first metal member 21 has an inner side of the outer circle 200 centered on the rotation center 105 and an outer side of the inner circle 201 so as to face the first detection coil pair 12. It is arranged along the area surrounded by.

  The second metal member 22 is surrounded by the inner side of the outer circle 202 centered on the rotation center 105 and the outer side of the inner circle 205 so as to face the second detection coil pair 13 and the third detection coil pair 14. It is arranged along the area.

  The third metal member 23 is disposed along a region surrounded by the inner side of the outer circle 206 around the rotation center 105 and the outer side of the inner circle 207 so as to face the fourth detection coil pair 15. Yes.

  The fourth metal member 24 is surrounded by the inner side of the outer circle 200 centered on the rotation center 105 and the outer side of the inner circle 203 so as to face the first detection coil pair 12 and the second detection coil pair 13. It is arranged along the area.

  The fifth metal member 25 is disposed along a region surrounded by the inner side of the outer circle 204 and the outer side of the inner circle 205 around the rotation center 105 so as to face the third detection coil pair 14. Yes.

  As shown in FIG. 2B, the sixth metal member 26 includes a metal piece 26a and a metal piece 26b. The metal piece 26 a is disposed along a region surrounded by the inner side of the outer circle 200 and the outer side of the inner circle 201 around the rotation center 105 so as to face the first detection coil pair 12. Further, the metal piece 26 b is disposed along a region surrounded by the inner side of the outer circle 206 centered on the rotation center 105 and the outer side of the inner circle 207 so as to face the fourth detection coil pair 15. .

  The seventh metal member 27 is disposed along a region surrounded by the inner side of the outer circle 202 around the rotation center 105 and the outer side of the inner circle 203 so as to face the second detection coil pair 13. Yes.

  The eighth metal member 28 is surrounded by the inner side of the outer circle 204 centered on the rotation center 105 and the outer side of the inner circle 207 so as to face the third detection coil pair 14 and the fourth detection coil pair 15. It is arranged along the area.

  Therefore, when the metal member rotates and moves with the rotation of the rotating member 10 and faces the detection coil pair, an eddy current that generates a magnetic field in a direction that cancels the alternating magnetic field 110 is generated by the action of the alternating magnetic field 110 of the excitation coil 11. Occurs in the member. The magnetic field that cancels this alternating magnetic field 110 is proportional to the area of the detection coil pair facing the metal member. Therefore, the detection signal output from the detection coil pair is not zero, but has a value corresponding to the position of the metal member.

As shown in FIG. 2B, the first metal member 21 to the eighth metal member 28 are predetermined, which are obtained by equally dividing the rotation detection range of the rotary member 10 by the number of metal members. They are arranged based on the angle θ ₁ .

Specifically, the first metal member 21 to the eighth metal member 28 have a detection range of 0 ° to 360 ° as described above, and the number of metal members is eight, so 45 °. Are arranged at intervals of That is, the predetermined angle θ ₁ is 45 °. That is, the metal members are arranged at a 45 ° pitch.

  Accordingly, the first metal member 21 is disposed such that the angle between the first metal member 21 and the second metal member 22 with respect to the rotation center 105 is 45 °. Therefore, the second metal member 22 to the eighth metal member 28 are arranged such that the angle with the adjacent metal member is 45 °.

The first metal member 21 to the eighth metal member 28 have, for example, a shape that is a part of a fan shape with a center angle of θ ₂ in a circle centered on the rotation center 105.

Since the first metal member 21 to the eighth metal member 28 include a metal member that faces one detection coil pair and a metal member that faces two detection coil pairs, their areas are different. In the case where the radius differences R ₁ to R ₄ between the outer circle and the inner circle shown in FIG. 2A are equal and the outer circle has a smaller radius, r, 2r, 3r, and 4r are approximated. The ratio of the areas of the third metal member 23, the fifth metal member 25, the seventh metal member 27, and the first metal member 21, which are metal members facing the pair, is approximately 1: 4: 9: 16. It becomes. The area of the first metal member 21 to the eighth metal member 28 based on this area is, for example, the third metal member 23 <the fifth metal member 25 <the eighth metal member 28 <the seventh metal. The member 27 <the second metal member 22 <the first metal member 21 <the sixth metal member 26 <the fourth metal member 24.

Accordingly, the amplitudes of the detection signals S ₂ to S ₉ output from the first detection coil pair 12 to the fourth detection coil pair 15 are proportional to the above-described area.

As shown in FIG. 2B, the first metal member 21 has a shape surrounded by a sector having a central angle θ ₂ formed based on the outer circle 200 and a region outside the inner circle 201. have. The difference in radius between the outer circle 200 and the inner circle 201 is R _1, which is the radial width of the first metal member 21.

  The shape of the first metal member 21 is, for example, in the top view of FIG. 5A, the ring portion and the half ring of the first detection coil 12a and the second detection coil 12b that are hidden by the first metal member 21. The area of the part is a shape that is substantially constant regardless of the position of the first metal member 21.

Incidentally, the difference R _{1 ~} difference R ₄ in this embodiment is equal, in the following referred to as R. Further, the difference in radius between the inner circle 201 and the outer circle 202, the inner circle 203 and the outer circle 204, and the inner circle 205 and the outer circle 206 is described as ΔR as shown in FIG.

As shown in FIG. 2B, the second metal member 22 has a shape surrounded by a sector having a central angle θ ₂ formed based on the outer circle 202 and a region outside the inner circle 205. have. The difference in radius between the outer circle 202 and the inner circle 203 is 2R + ΔR, which is the radial width of the second metal member 22.

  The shape of the second metal member 22 is, for example, an annular portion and a half ring of the third detection coil 13a to the sixth detection coil 14b hidden in the second metal member 22 in the top view of FIG. The area of the part is a shape that is substantially constant regardless of the position of the second metal member 22.

As shown in FIG. 2B, the third metal member 23 has a shape surrounded by a sector shape having a central angle θ ₂ formed based on the outer circle 206 and a region outside the inner circle 207. have. The difference in radius between the outer circle 206 and the inner circle 207 is R, which is the radial width of the third metal member 23.

  The shape of the third metal member 23 is, for example, the ring portion and the half ring of the seventh detection coil 15a and the eighth detection coil 15b hidden in the third metal member 23 in the top view of FIG. The area of the part is a shape that is substantially constant regardless of the position of the third metal member 23.

As shown in FIG. 2B, the fourth metal member 24 has a shape surrounded by a sector having a central angle θ ₂ formed based on the outer circle 200 and a region outside the inner circle 203. have. The difference in radius between the outer circle 200 and the inner circle 203 is 2R + ΔR, which is the radial width of the fourth metal member 24.

  The shape of the fourth metal member 24 is, for example, in the top view of FIG. 6A, the first detection coil 12 a to the fourth detection coil 13 b that are hidden by the fourth metal member 24 and the half ring. The area of the part is a shape that is substantially constant regardless of the position of the fourth metal member 24.

As shown in FIG. 2B, the fifth metal member 25 has a shape surrounded by a sector having a central angle θ ₂ formed based on the outer circle 204 and a region outside the inner circle 205. have. The difference in radius between the outer circle 204 and the inner circle 205 is R, which is the radial width of the fifth metal member 25.

  The shape of the fifth metal member 25 is, for example, in the top view of FIG. 6B, the ring part and the half ring of the fifth detection coil 14a and the sixth detection coil 14b hidden by the fifth metal member 25. The area of the part is a shape that is substantially constant regardless of the position of the fifth metal member 25.

As shown in FIG. 2A, the metal piece 26 a of the sixth metal member 26 includes a sector shape having a central angle θ ₂ formed based on the outer circle 200, and a region outside the inner circle 201. It has an enclosed shape. The difference in radius between the outer circle 200 and the inner circle 201 is R, which is the radial width of the first metal member 21. Further, the metal piece 26 _b has a shape surrounded by a sector having a central angle θ ₂ formed based on the outer circle 206 and a region outside the inner circle 207. The difference in radius between the outer circle 206 and the inner circle 207 is R, which is the radial width of the third metal member 23.

  The shape of the metal piece 26a of the sixth metal member 26 is the same as that of the first metal member 21 as shown in FIG. 6C, for example. The shape of the metal piece 26b is the same as that of the third metal member 23 as shown in FIG. 6C, for example.

As shown in FIG. 2B, the seventh metal member 27 has a shape surrounded by a sector having a central angle θ ₂ formed based on the outer circle 202 and a region outside the inner circle 203. have. The difference in radius between the outer circle 202 and the inner circle 203 is R, which is the radial width of the seventh metal member 27.

  The shape of the seventh metal member 27 is, for example, in the top view of FIG. 7A, the ring part and the half ring of the third detection coil 13a and the fourth detection coil 13b hidden by the seventh metal member 27. The area of the part is a shape that is substantially constant regardless of the position of the seventh metal member 27.

As shown in FIG. 2B, the eighth metal member 28 has a shape surrounded by a sector having a central angle θ ₂ formed based on the outer circle 204 and an area outside the inner circle 207. have. The difference in radius between the outer circle 204 and the inner circle 207 is 2R + ΔR, which is the radial width of the eighth metal member 28.

  The shape of the eighth metal member 28 is, for example, in the top view of FIG. 7B, the ring part and the half ring of the fifth detection coil 14a to the fifth detection coil 15b hidden by the eighth metal member 28. The area of the part is a shape that is substantially constant regardless of the position of the eighth metal member 28.

  Therefore, the shape of the metal member is not limited to the fan shape of the present embodiment. In the top view of FIG. 5A, the area of the ring part and the half ring part of the detection coil pair hidden by the metal member is in the position. Regardless, it may be a shape that is substantially constant.

3A, after the right side 112 of the exciting coil 11 and the side surface 210 of the first metal member 21 coincide with each other, the left side 113 of the exciting coil 11 and the first side opposite sides 211 of the side surface 210 of the first metal member 21, the rotation angle until the match, since it is the side surface 151 and side surface 152 is an angle based on the central angle theta _2, the 55 °.

  Rotation until the side 113 of the exciting coil 11 and the side surface 221 of the second metal member 22 coincide after the side 112 of the exciting coil 11 and the side surface 220 of the second metal member 22 coincide. The angle is similarly 55 °.

  Rotation until the side 113 of the exciting coil 11 and the side surface 231 of the third metal member 23 coincide with each other after the side 112 of the exciting coil 11 and the side surface 230 of the third metal member 23 coincide with each other. The angle is 55 °.

  Rotation from when the side 112 of the exciting coil 11 and the side surface 240 of the fourth metal member 24 coincide with each other until the side 113 of the exciting coil 11 and the side surface 241 of the fourth metal member 24 coincide with each other. The angle is 55 °.

  Rotation from when the side 112 of the exciting coil 11 and the side surface 250 of the fifth metal member 25 match until the side 113 of the exciting coil 11 and the side surface 251 of the fifth metal member 25 match. The angle is 55 °.

  After the side 112 of the exciting coil 11, the side surface 260a of the metal piece 26a of the sixth metal member 26, and the side surface 260b of the metal piece 26b coincide, the side 113 of the exciting coil 11 and the sixth metal member The rotation angle until the side surface 261a of the metal piece 26a and the side surface 261b of the metal piece 26b coincide with each other is 55 °.

Rotation from when the side 112 of the exciting coil 11 and the side surface 270 of the seventh metal member 27 coincide with each other until the side 113 of the exciting coil 11 coincides with the side surface 271 of the seventh metal member 27 The angle is 55 ° because the side surface 270 and the side surface 271 are angles based on the central angle θ ₂ .

  Rotation from when the side 112 of the exciting coil 11 and the side surface 280 of the eighth metal member 28 coincide with each other until the side 113 of the exciting coil 11 and the side surface 281 of the eighth metal member 28 coincide with each other. The angle is 55 °.

  Here, as shown in FIG. 7C, the rotation detection device 1 may have two metal members positioned on the excitation coil 11 depending on the rotation angle of the rotation member 10. For example, when adjacent metal members having a pitch are positioned in a region sandwiched between the same outer circle and inner circle, when the adjacent metal members having a pitch are positioned on the excitation coil 11, a detection signal is output from the same detection coil pair. Therefore, accurate detection accuracy cannot be obtained. Therefore, the metal members and metal pieces having adjacent pitches are not arranged in a region sandwiched between the same outer circle and inner circle.

(Configuration of control unit 40)
The control unit 40 includes, for example, a CPU (Central Processing Unit) that performs operations and processing on acquired data according to a stored program, a RAM (Random Access Memory) that is a semiconductor memory, a ROM (Read Only Memory), and the like. Microcomputer. In this ROM, for example, a program for operating the control unit 40 is stored. For example, the RAM is used as a storage area for temporarily storing calculation results and the like.

As shown in FIGS. 8A to 8D, the control unit 40 determines the rotation angle of the rotating member 10 based on the detection signals S ₂ to S ₉ acquired from the detection coil group 16. It is configured.

Specifically, as illustrated in FIG. 8A, the control unit 40 rotates the rotation angle from −5 ° to 50 ° based on the detection signal S ₂ and the detection signal S ₃ of the first detection coil pair 12. Determine.

Control unit 40, as shown in FIG. 8 (b) and FIG. 8 (c), the a detection signal _{S 4} and the detection signal _{S 5} of the second detection coil pair 13, the detection signal of the third detection coil pair 14 based on the S ₆ and the detection signal _{S 7} determines the rotation angle of up to 40 ° to 95 °.

Control unit 40, as shown in FIG. 8 (d), determining the rotational angle of up to 85 ° to 140 ° based on the detection signal _{S 8} and the detection signal _{S 9} of the fourth detection coil pair 15.

As shown in FIGS. 8A and 8B, the control unit 40 detects the detection signal S ₂ and the detection signal S _{3 of} the first detection coil pair 12 and the detection signal of the second detection coil pair 13. based on the S ₄ and the detection signal _{S 5} determines a rotation angle of up to 130 ° to 185 °.

As illustrated in FIG. 8C, the control unit 40 determines the rotation angle from 175 ° to 230 ° based on the detection signal S ₆ and the detection signal S ₇ of the third detection coil pair 14.

Control unit 40, as shown in FIG. 8 (a) and FIG. 8 (d), the a detection signal _{S 2} and the detection signal _{S 3} of the first detection coil pair 12, the detection signal of the fourth detection coil pairs 15 based on the S ₈ and the detection signal _{S 9} determines a rotation angle of up to 220 ° to 275 °.

As shown in FIG. 8B, the control unit 40 determines a rotation angle from 265 ° to 320 ° based on the detection signal S ₄ and the detection signal S ₅ of the second detection coil pair 13.

Control unit 40, as shown in FIG. 8 (c) and FIG. 8 (d), the a detection signal _{S 6} and the detection signal _{S 7} of the third detection coil pair 14, the detection signal of the fourth detection coil pairs 15 determining a rotation angle of up to 310 ° ~365 °, based on the S ₈ and the detection signal _{S 9.}

As described above, the control unit 40, for example, on the basis of the detection signal S _{2 ~} detection signal S ₉ obtained, with determining the combination of the detection coil pair which outputs a detection signal, based on the obtained detection signal The rotation angle θ is determined.

Control unit 40 is configured to generate operation information S ₁₀ including the information of the rotational angle θ based on the determination result. Hereinafter, the determination of the rotation angle θ of the rotating member 10 will be described.

(About determination of rotation angle θ)
In the first metal member 21, for example, on the paper surface of FIG. 5A, the side surface 210 moves from the right side 112 of the exciting coil 11 to the left side 113 along with the rotation of the rotating member 10. By this movement, as shown in FIG. 8 (a), after the side surface 210 exceeds the edge 112, the detection signal toward the _{S 3} of the first detection coil 12a of the detection signal _S than ₂ second detection coil 12b Rises steeply. In the present embodiment, the rotation angle θ in a state where the side surface 210 and the side 112 of the first metal member 21 coincide with each other is set to −5 °.

Since the position where the side surface 210 of the first metal member 21 exceeds the side 112 of the exciting coil 11 is the end of the ring portion 120a of the first detection coil 12a, the area covered by the first metal member 21 is a detection signal S ₂ is also almost zero almost becomes zero.

On the other hand, the position where the side surface 210 of the first metal member 21 exceeds the side 112 of the exciting coil 11 is the end of the half ring portion 120b of the second detection coil 12b. since the width is covered portions is the maximum, the detection signal S ₃ rises becomes steep than the detection signal S _2.

However, the half ring portion 120b has only about half the area of the ring portion 120a. Therefore the detection signal S ₃ when the semi-ring portion 120b is covered in the second detection coil 12b, as shown in FIG. 8 (a), although the rise is steep, the ring portion of the first detection coil 12a the maximum voltage _{V 2} is about half the magnitude of the maximum voltages _{V 1} at 120a.

When the rotating member 10 further rotates, the first metal member 21 has the largest area covering the ring part 120a of the first detection coil 12a, and the areas of the half ring part 120b and the ring part 121b of the second detection coil 12b. Move to a position that equally covers. This position has a rotation angle of 11.25 °. Therefore, in this rotation angle detection signal _{S 2,} the maximum voltages _{V 1,} and the detection signal _{S 3} is zero.

When the rotating member 10 further rotates, the first metal member 21 covers the ring part 120a and the ring part 121a of the first detection coil 12a equally, and the area covered by the ring part 121b of the second detection coil 12b is maximized. Move to a position. This position has a rotation angle of 22.5 °. Therefore, at this rotation angle, the detection signal S ₂ is zero, and the detection signal S ₃ is a voltage (−V ₁ ) having the maximum absolute value.

When the rotating member 10 further rotates, the first metal member 21 has the largest area covering the ring part 121a of the first detection coil 12a, and the areas of the ring part 121b and the half ring part 122b of the second detection coil 12b. Move to a position that equally covers. This position has a rotation angle of 33.75 °. Therefore, in this rotation angle detection signal S _2, the voltage absolute value becomes maximum (-V _1), and the detection signal S ₃ is zero.

When the rotating member 10 further rotates, the side surface 210 of the first metal member 21 coincides with the side 113 of the exciting coil 11. The rotation angle for reaching this position is 40 °. Then, the first metal member 21, to go out of the exciting coil 11, it is necessary to rotate further 10 °, upon reaching the rotation angle 50 °, the detection signal S ₂ and the detection signal S _3, Both become zero.

When the rotation angle θ of the rotating member 10 reaches 40 °, the side surface 220 of the second metal member 22 reaches the side 112 as shown in FIGS. 5B, 8B, and 8C. To do. The second metal member 22, so has a size over the second detection coil pair 13 and the third detection coil pair 14, the detection signal S _{4 ~} detection signal S ₇ is outputted.

The graph of the detection signals S ₄ and the detection signal S ₆ has a shape in which the amplitude of the graph of the detection signal S ₂ shown in FIG. 8 (a) is reduced according to the area of the metal member. The maximum voltage of the detection signal _{S 4} and the detection signal _{S 6} is a voltage _{V 3} and the voltage _{V 5.} A graph of the detection signals S ₅ and the detection signal S ₇ has a shape in which the amplitude of the graph of the detection signal S ₃ shown in FIG. 8 (a) is reduced according to the area of the metal member. The maximum voltage of the detection signal _{S 5} and the detection signal _{S 7} is a voltage _{V 4} and the voltage _{V 6.}

  The rotation angle θ of the rotary member 10 from when the side surface 220 of the second metal member 22 reaches the side 112 to when the opposite side surface 221 reaches the side 113 is 40 ° to 95 °.

When the rotation angle θ of the rotating member 10 reaches 85 °, the side surface 230 of the third metal member 23 reaches the side 112 as shown in FIGS. 5C and 8D. Third metal member 23, so opposite to the fourth detection coil pair 15, the detection signal S ₈ and the detection signal S ₉ is output.

The graph of the detection signal S _8, the amplitude of the graph of the detection signal S ₂ has a shape having the reduced according to the area of the metal member. The maximum voltage of the detection signal _{S 2} is the voltage _{V 7.} A graph of the detection signal S _9, the amplitude of the graph of the detection signal S ₃ has a shape which becomes smaller in accordance with the area of the metal member. The maximum voltage of the detection signal _{S 3} is a voltage _{V 8.}

  The rotation angle θ of the rotating member 10 from when the side surface 230 of the third metal member 23 reaches the side 112 to when the opposite side surface 231 reaches the side 113 is 85 ° to 140 °.

When the rotation angle θ of the rotating member 10 reaches 130 °, the side surface 240 of the fourth metal member 24 reaches the side 112 as shown in FIGS. 6 (a), 8 (a), and 8 (b). To do. Fourth metal member 24, so opposite to the first detection coil pair 12 and the second detection coil pair 13, the detection signal S _{2 ~} detection signal S ₅ is output.

  The rotation angle θ of the rotating member 10 from when the side surface 240 of the fourth metal member 24 reaches the side 112 to when the opposite side surface 241 reaches the side 113 is 130 ° to 185 °.

When the rotation angle θ of the rotating member 10 reaches 175 °, the side surface 250 of the fifth metal member 25 reaches the side 112 as shown in FIGS. 6B and 8C. The fifth metallic member 25, so opposite to the third detection coil pair 14, the detection signal S ₆ and the detection signal S ₇ is outputted.

  The rotation angle θ of the rotating member 10 from when the side surface 250 of the fifth metal member 25 reaches the side 112 to when the opposite side surface 251 reaches the side 113 is 175 ° to 230 °.

When the rotation angle θ of the rotating member 10 reaches 220 °, as shown in FIGS. 6C, 8A, and 8D, the sixth metal member 25 (the metal piece 26a and the metal piece 26b is used). ) Side surfaces (side surface 260 a and side surface 260 b) reach side 112. Since the sixth metal member 26 faces the first detection coil pair 12 and the fourth detection coil pair 15, the detection signal S ₂ , the detection signal S ₃ , the detection signal S ₈ and the detection signal S ₉ are output. The

  The rotation angle θ of the rotating member 10 from when the side surfaces (side surface 260a and side surface 260b) of the sixth metal member 26 reach the side 112 to when the opposite side surfaces (side surface 261a and side surface 261b) reach the side 113 is 220 ° to 275 °.

When the rotation angle θ of the rotating member 10 reaches 265 °, the side surface 270 of the seventh metal member 27 reaches the side 112 as shown in FIGS. 7A and 8B. The metal member 27 of the seventh, since facing the second detection coil pair 13, the detection signal S ₄ and the detection signal S ₅ is output.

  The rotation angle θ of the rotating member 10 from when the side surface 270 of the seventh metal member 27 reaches the side 112 to when the opposite side surface 271 reaches the side 113 is 265 ° to 320 °.

When the rotation angle θ of the rotating member 10 reaches 310 °, the side surface 280 of the eighth metal member 28 reaches the side 112 as shown in FIGS. 7B, 8C, and 8D. To do. Metal member 28 of the eighth, because opposite to the third detection coil pair 14 and the fourth detection coil pair 15, the detection signal S _{6 ~} detection signal S ₉ is output.

  The rotation angle θ of the rotating member 10 from when the side surface 280 of the eighth metal member 28 reaches the side 112 to when the opposite side surface 281 reaches the side 113 is 310 ° to 365 °.

Here, as shown in FIG. 7C, when the adjacent metal members (for example, the second metal member 22 and the third metal member 23) are located above the exciting coil 11, the detection is performed. Signal S ₃ to detection signal S ₈ have non-zero voltages. However, since the detection signal S ₃ to the detection signal S ₈ are input in parallel, the control unit 40 can be distinguished. Therefore, the control unit 40 can determine the rotation angle of the rotating member 10 even when the adjacent metal member is located above the exciting coil 11.

  Moreover, since the detection coil pair is composed of two detection coils having different connection patterns of the ring portion and the half ring portion, the detection signals for the detection coils are different. Therefore, the control unit 40 can accurately determine the rotation angle based on the acquired detection signal.

  The rotation detection device 1 can detect the rotation angles of the rotation member 10 in the arrow A direction and the arrow B direction on the paper surface of FIG.

(About connection with vehicle LAN55)
The rotation detection device 1 is electromagnetically connected to the vehicle LAN 55 as shown in FIG. 4B, for example. A display device 6, an air conditioner 7, and a navigation device 8 are electromagnetically connected to the vehicle LAN 55.

  Note that the above-described electromagnetic connection is a connection using at least one of a connection using a conductor, a connection using light which is a kind of electromagnetic wave, and a connection using radio wave which is a kind of electromagnetic wave.

  Below, operation | movement of the rotation detection apparatus 1 which controls the air conditioner 7 as a to-be-controlled apparatus is demonstrated.

(Operation)
When the power of the vehicle 5 is turned on, the control unit 40 of the rotation detection device 1 generates an AC signal S ₁ and outputs it to the exciting coil 11.

The exciting coil 11 generates an alternating magnetic field 110 based on the AC signal S ₁ supplied.

  When the operator rotates the knob 102 of the rotating member 10, at least one detection coil of the first detection coil pair 12 to the fourth detection coil pair 15 according to the metal member located above the excitation coil 11. A detection signal from the pair is obtained.

Control unit 40 determines the rotation angle θ of the rotating member 10 based on the obtained detection signal, and generates operation information S ₁₀ based on the rotation angle θ which is determined, the air conditioning system 7 via the vehicle LAN55 Output.

Air conditioner 7 executes based on the operation information S ₁₀ acquired functions.

(Effects of the first embodiment)
The rotation detection device 1 according to the present embodiment can detect the rotation operation for at least one rotation, but can make the region where the detection coil is installed smaller than 360 °. Specifically, in the rotation detection device 1, the first detection coil 12a to the eighth detection coil 15b are arranged along a part of the circumference of the concentric circle, and the first detection coil 12a to the eighth detection coil. An excitation coil 11 forming a 45 ° fan-shaped arrangement region 111 is arranged so as to surround the detection coil 15b. Accordingly, in the rotation detection device 1, the area occupied by the excitation coil 11, the first detection coil 12a to the sixth detection coil 14b is smaller than when the detection coil is arranged along the entire circumference. Can be downsized.

  In the rotation detection device 1, the detection coil is arranged along a part of the circumference, and can detect a rotation angle larger than the rotation angle based on the part.

  Since the rotation detection device 1 detects the rotation angle of the rotating member 10 based on two different detection signals of a detection coil pair in which detection coils having different patterns are combined, the rotation angle is detected by the detection coil of one pattern. Compared with, accuracy is improved. For example, when the detection signal has a sinusoidal shape, two rotation angles correspond to at least the same voltage. However, since this rotation detection device 1 makes a determination based on two different detection signals, as shown in FIGS. 8A to 8D, two rotation angles are applied to the voltage of the sinusoidal detection signal. However, it is possible to determine which rotation angle is based on other detection signals, and the accuracy is improved.

In addition, since the rotation detection device 1 is provided so that the metal member covers the plurality of detection coil pairs, the rotation angle θ can be determined by a combination of the plurality of detection coil pairs. The rotation detection device 1 determines the rotation angle θ by a combination of a plurality of detection coil pairs, thereby reducing the number of detection coil pairs and the number of excitation coils 11 compared to the case where no combination of detection coil pairs is used. The central angle θ ₃ is reduced and the size can be reduced.

  As a modification, the control unit 40 stores the acquired detection signals, and detects a rotation angle of 360 ° or more in the arrow A direction and the arrow B direction of the rotating member 10 based on the stored detection signals. It may be configured.

[Second Embodiment]
The second embodiment is different from the first embodiment in the combination of metal members.

  FIG. 9 is a rear view of the rotating member for explaining the arrangement of the metal members of the rotation detecting device according to the second embodiment. FIG. 10A is a graph of a detection signal output from the first detection coil pair of the rotation detection device according to the second embodiment, and FIG. 10B is a graph from the second detection coil pair. FIG. 10C is a graph of the detection signal output from the third detection coil pair, and FIG. 10D is a graph of the detection signal output from the fourth detection coil pair. It is a graph of a detection signal. In the following embodiments, portions having the same functions and configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  In the rotation detection device 1 of the present embodiment, as shown in FIG. 9, the first metal member 21 a to the eighth metal member 28 a are arranged on the back surface 101 b of the rotation member 10 at a 45 ° pitch.

  The first metal member 21 a is disposed at a position facing the first detection coil pair 12 and the second detection coil pair 13 as shown in FIGS. 9, 10 (a), and 10 (b). In addition, it has a shape that spans the first detection coil pair 12 and the second detection coil pair 13.

  The second metal member 22 a is disposed at a position facing the third detection coil pair 14 and the fourth detection coil pair 15 as shown in FIGS. 9, 10 (c) and 10 (d). In addition, it has a shape that spans the third detection coil pair 14 and the fourth detection coil pair 15.

  As shown in FIGS. 9 and 10A, the third metal member 23 a is disposed at a position facing the first detection coil pair 12 and has a shape corresponding to the first detection coil pair 12. Have.

  The fourth metal member 24 a is disposed at a position facing the second detection coil pair 13 and the third detection coil pair 14 as shown in FIGS. 9, 10 (b) and 10 (c). In addition, it has a shape that spans the second detection coil pair 13 and the third detection coil pair 14.

  As shown in FIG. 9, the fifth metal member 25a includes a metal piece 25b and a metal piece 25c. The metal piece 25 b is disposed at a position facing the first detection coil pair 12 and has a shape corresponding to the first detection coil pair 12. The metal piece 25 c is disposed at a position facing the fourth detection coil pair 15 and has a shape corresponding to the fourth detection coil pair 15.

  As shown in FIGS. 9 and 10B, the sixth metal member 26 c is disposed at a position facing the second detection coil pair 13 and has a shape corresponding to the second detection coil pair 13. Have.

  As shown in FIG. 9, the seventh metal member 27a includes a metal piece 27b and a metal piece 27c. The metal piece 27 b is disposed at a position facing the first detection coil pair 12 and has a shape corresponding to the first detection coil pair 12. The metal piece 27 c is disposed at a position facing the third detection coil pair 14 and has a shape corresponding to the third detection coil pair 14.

  As shown in FIGS. 9 and 10D, the eighth metal member 28 a is disposed at a position facing the fourth detection coil pair 15 and has a shape corresponding to the fourth detection coil pair 15. Have.

  As shown in FIGS. 10 (a) to 10 (d), in the rotation detection device 1, if adjacent metal members face the same detection coil pair, detection signals overlap and it is difficult to determine the rotation angle θ. The adjacent metal members are arranged so as not to face the same detection coil.

(effect)
Since the rotation detection device 1 of the present embodiment is arranged around a metal member having a large amplitude of the detection signal, the determination is easy.

  As a modification, the above-described detection coil has a curved shape in the ring portion and the semi-ring portion, but may have a rectangular shape.

  As another modification, the metal member may be disposed on the base 3, and the detection coil and the excitation coil may be disposed on the rotating member 10.

  The rotation detection device 1 in the above-described embodiment is configured to detect the rotation of the rotating member due to the operation, but is not limited thereto, and as an example, configured to detect the rotation of the driven shaft or the like. May be.

  According to the rotation detection device 1 of at least one embodiment described above, the region where the detection coil is installed can be made smaller than 360 ° while the rotation operation for at least one rotation can be detected. Become.

  In the rotation detection device 1 according to the above-described embodiment and modification, for example, a part or all of the functions of the control unit 40 are executed by a computer, a program executed by a computer, an ASIC (Application Specific Integrated Circuit), and an FPGA (Field Programmable Gate Array). ) Or the like.

  The ASIC is an application specific integrated circuit, and the FPGA is an LSI (Large Scale Integration) that can be programmed.

  As mentioned above, although some embodiment and modification of this invention were demonstrated, these embodiment and modification are only examples, and do not limit the invention based on a claim. These novel embodiments and modifications can be implemented in various other forms, and various omissions, replacements, changes, and the like can be made without departing from the scope of the present invention. In addition, not all combinations of features described in these embodiments and modifications are necessarily essential to the means for solving the problems of the invention. Furthermore, these embodiments and modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Rotation detection apparatus, 3 ... Base | substrate, 5 ... Vehicle, 6 ... Display apparatus, 7 ... Air conditioner, 8 ... Navigation apparatus, 9 ... Hand, 10 ... Rotating member, 11 ... Excitation coil, 12-15 ... 1st Detection coil pair to fourth detection coil pair, 12a ... first detection coil, 12b ... second detection coil, 13a ... third detection coil, 13b ... fourth detection coil, 14a ... fifth detection coil , 14b ... sixth detection coil, 15a ... seventh detection coil, 15b ... eighth detection coil, 16 ... detection coil group, 21-28 ... first metal member to eighth metal member, 21a-25a ... first metal member to fifth metal member, 25b ... metal piece, 25c ... metal piece, 26a ... metal piece, 26b ... metal piece, 26c ... sixth metal member, 27a ... seventh metal member, 27b ... Metal piece, 27c ... Metal piece, 28a ... Eighth metal 30 ... front surface, 31 ... back surface, 40 ... control unit, 50 ... center console, 55 ... vehicle LAN, 60 ... display screen, 61 ... display image, 100 ... rotating shaft, 101 ... base, 101a ... front surface, 101b ... Back surface, 102 ... knob, 105 ... center of rotation, 110 ... alternating magnetic field, 111 ... arrangement region, 112 ... side, 113 ... side, 115 ... intersection, 116-119 ... first circle to fourth circle, 120a ... ring Part, 120b ... half ring part, 121a ... ring part, 121b ... ring part, 122b ... half ring part, 130a ... ring part, 130b ... half ring part, 131a ... ring part, 131b ... ring part, 132b ... half ring part 140a ... ring part, 140b ... semi-ring part, 141a ... ring part, 141b ... ring part, 142b ... semi-ring part, 150a ... ring part, 150b ... semi-ring part, 151 ... side face, 151a ... ring part, 151b ... Ring part, 152 ... side , 152b ... semi-annular part, 200 ... outer circle, 201 ... inner circle, 202 ... outer circle, 203 ... inner circle, 204 ... outer circle, 205 ... inner circle, 206 ... outer circle, 207 ... inner circle, 210 ... side face , 211 ... side surface, 220 ... side surface, 221 ... side surface, 230 ... side surface, 240 ... side surface, 241 ... side surface, 250 ... side surface, 251 ... side surface, 260a ... side surface, 260b ... side surface, 261a ... side surface, 261b ... Side, 270 ... Side, 271 ... Side, 280 ... Side, 281 ... Side

Claims (7)

A rotating member that rotates about a rotation axis;
An exciting coil that is disposed on the substrate facing the rotating member and generates an alternating magnetic field based on the supplied AC signal;
A detection coil group consisting of detection coils that are located in a region surrounded by the excitation coil and arranged along a part of the circumference of each concentric circle centering on the intersection of the rotating shaft and the base;
A first alternating magnetic field changing unit that is arranged in the radial direction of the rotating member, has a shape that faces a plurality of detection coils of the detection coil group, and changes the alternating magnetic field that acts on the plurality of opposing detection coils. When,
The alternating member that is arranged in a radial direction different from the first alternating magnetic field changing portion of the rotating member, has a shape that faces one detection coil of the detection coil group, and acts on the one detection coil that faces the other. A second alternating magnetic field changing section for changing the magnetic field;
Rotation detection device with The first alternating magnetic field changing unit and the second alternating magnetic field changing unit are formed based on a circle centering on an intersection between the rotation surface on which the alternating magnetic field changing unit is arranged and the rotation axis. Having a shape surrounded by a sector having a predetermined center angle and a region outside the circle centered on the intersection and having a different radius from the circle,
The rotation detection device according to claim 1. The detection coil that is paired with the detection coil is provided on the base body while being laminated while maintaining insulation.
The rotation detection device according to claim 1 or 2. The detection coil and the pair of detection coils have different shapes, and have a line-symmetric shape with respect to an axis of symmetry passing through the intersection.
The rotation detection device according to claim 3. The detection coil has a shape in which two first ring portions having a ring shape are connected, and areas of regions surrounded by the first ring portions are substantially equal to each other,
The rotation detection device according to claim 3 or 4. The pair of detection coils includes a second ring portion having a ring shape, and two half-ring portions obtained by cutting the second ring portion in a radial direction of the concentric circle, and the second ring portion is The area of the region surrounded by the second ring portion and the area of two regions surrounded by the half ring portion have shapes connected as centers, and the area of the first ring of the corresponding detection coil Substantially equal to the area of two of the annulus,
The rotation detection device according to claim 5. A determination unit that determines a rotation angle of the rotating member based on a first detection signal acquired from the detection coil and a second detection signal acquired from the pair of detection coils;
The rotation detection device according to any one of claims 3 to 6.

Images