JP6435811B2 - Magnetic position detector - Google Patents

Description

  The present invention relates to a magnetic position detection device.

  As a conventional magnetic position detecting device, a shaft extending in the horizontal direction, a slider movable relative to the shaft in the axial direction of the shaft, a magnetic element for detecting a magnetic flux generated by the shaft, and a detection value of the magnetic element And a position detection unit that detects the position of the slider with respect to the shaft. In such a magnetic position detection device, in order to compensate for the influence caused by the shaft swing (deflection and / or swing) in the vertical direction, the magnetic element may be disposed directly above and below the shaft. (For example, refer to Patent Document 1).

Japanese Utility Model Publication 2-14016

  In the magnetic position detection device as described above, the shaft swings not only in the vertical direction but also in the horizontal direction. Therefore, the slider with respect to the shaft is caused by the shaft swinging (bending and / or shaking) in the vertical direction and the horizontal direction. There is a risk that the position detection accuracy will decrease.

  Therefore, an object of the present invention is to provide a magnetic position detection device that can accurately detect the position of a slider with respect to a shaft.

  The magnetic position detection device of the present invention includes a shaft that extends in the horizontal direction and in which N poles and S poles are alternately arranged in the axial direction, and a slider that is disposed so as to be relatively movable in the axial direction with respect to the shaft. And a magnetic detection unit that is attached to the slider and that detects the magnetic flux generated by the shaft and includes a first magnetic element and a second magnetic element, and a detection value for the shaft based on the detection values of the first magnetic element and the second magnetic element. A position detection unit that detects a position of the slider, and the first magnetic element and the second magnetic element are in a region partitioned by a vertical line and a horizontal line passing through the center line of the shaft on a virtual plane orthogonal to the axial direction. Among these, the first region and the second region that are not adjacent to each other are arranged so as to sandwich the shaft.

  In the magnetic position detection apparatus having this configuration, the first magnetic element and the second magnetic element are arranged with a shaft and a horizontal line passing through the center line of the shaft sandwiching a shaft on a virtual plane orthogonal to the axial direction of the shaft. Yes. For this reason, when the shaft swings in the vertical direction with respect to the first magnetic element and the second magnetic element, the magnetic flux detected by one magnetic element is weakened and the magnetic flux detected by the other magnetic element is strengthened. That is, for example, an addition value of detection values detected by the first magnetic element and the second magnetic element is constant. Thus, since the position of the slider is detected using a constant addition value, the vertical shake of the shaft relative to the first magnetic element and the second magnetic element is compensated. Further, in the magnetic position detection device having this configuration, the first magnetic element and the second magnetic element are arranged on the virtual plane with the shaft and the vertical line passing through the center line of the shaft interposed therebetween. For this reason, when the shaft swings in the horizontal direction with respect to the first magnetic element and the second magnetic element, the magnetic flux detected by one element is weakened and the magnetic flux detected by the other element is increased. That is, for example, an addition value of detection values detected by the first magnetic element and the second magnetic element is constant. Thus, since the position of the slider is detected using a constant addition value, the horizontal shake of the shaft with respect to the first magnetic element and the second magnetic element is compensated. By these actions, even if the shaft is swung in the vertical direction and / or the horizontal direction with respect to the first magnetic element and the second magnetic element due to bending and / or shaking, the shaking can be compensated. As a result, the position of the slider with respect to the shaft can be detected with high accuracy.

  In the magnetic position detection device of the present invention, the slider has a housing having a hole in which the shaft is disposed with a gap and a coil accommodated in the housing, and the slider is formed by the shaft and the coil. The first magnetic element and the second magnetic element can be moved in the axial direction by magnetic interaction, and can be attached to the housing in a state shifted from the coil in the axial direction.

  According to this configuration, the slider can be driven using a magnetic field generated by passing a current through the coil. For this reason, the slider can be moved relative to the shaft without separately providing a drive unit for moving the slider. Moreover, since the 1st magnetic element and the 2nd magnetic element are attached to the housing | casing in the state which shifted | deviated to the axial direction from the coil, the influence of the magnetic flux (leakage magnetic flux) which arises from a coil can be reduced. Thereby, the resolution of the magnetic position detection device can be increased.

  In the magnetic position detection device of the present invention, the first magnetic element and the second magnetic element may be disposed inside the outer shape of the housing when viewed from the axial direction.

  According to this configuration, since the first magnetic element and the second magnetic element can be disposed close to the shaft, the positional accuracy can be further improved.

  In the magnetic position detection apparatus of the present invention, the magnetic detection unit further includes a third magnetic element and a fourth magnetic element that detect magnetic flux generated by the shaft, and the position detection unit includes the first magnetic element, the second magnetic element, The position of the slider with respect to the shaft is detected based on the detection values of the third magnetic element and the fourth magnetic element, and the third magnetic element and the fourth magnetic element are partitioned by a vertical line and a horizontal line on a virtual plane. Are arranged so that the shaft is sandwiched between the third region and the fourth region that are not adjacent to each other, and the first magnetic element and the second magnetic element detect the first direction component of the magnetic flux, The magnetic element and the fourth magnetic element may detect the second direction component of the magnetic flux orthogonal to the first direction component.

  The region indicated by the first region and the second region and the region indicated by the third region and the fourth region may be the same region.

  According to this configuration, since the first magnetic element, the second magnetic element, the third magnetic element, and the fourth magnetic element are arranged on the same virtual plane, the first magnetic element is disposed at a plurality of positions in the axial direction of the shaft. -The arrangement | positioning space of the axial direction of a shaft can be suppressed compared with the case where a 4th magnetic element is provided.

  In the magnetic position detection apparatus of the present invention, the first magnetic element, the second magnetic element, the third magnetic element, and the fourth magnetic element may be arranged in a state shifted by π / 2 around the center line. .

  According to this configuration, an increase in the size of the slider when viewed from the axial direction of the shaft can be suppressed.

  In the magnetic position detection apparatus of the present invention, the position detection unit corresponds to the first triangular wave sin (x) × sin (ωt) by adding the detection values of the first magnetic element and the second magnetic element. The first addition value is output, and the second addition value corresponding to the second triangular wave cos (x) × sin (ωt) is output by adding the detection values of the third magnetic element and the fourth magnetic element. And an adder that outputs a synthesized value corresponding to the synthesized wave sin (ωt ± x) or cos (ωt ± x) using the addition theorem based on the first added value and the second added value; A zero-cross detector that detects a phase x obtained by shifting the synthesized wave sin (ωt ± x) or cos (ωt ± x) with respect to the reference wave sin (ωt) or cos (ωt) based on the synthesized value; Based on the phase x detected by the detector A position calculating unit that calculates the position of the slider.

According to this configuration, the position of the slider in the axial direction with respect to the shaft is calculated based on the combined value that is a signal in which the shake in the vertical direction and the horizontal direction is compensated. Thus, the axial position of the slider relative to sheet Yafuto with high accuracy is calculated.

  In the magnetic position detection apparatus of the present invention, the position detection unit corresponds to the first triangular wave sin (x) × sin (ωt) by adding the detection values of the first magnetic element and the second magnetic element. The first addition value is output, and the second addition value corresponding to the second triangular wave cos (x) × sin (ωt) is output by adding the detection values of the third magnetic element and the fourth magnetic element. And a first synthesized value corresponding to the first synthesized wave sin (ωt ± d + x1) or cos (ωt ± d + x1) using the addition theorem based on the first added value and the second added value And the second corresponding to the second composite wave sin (ωt ± d−x2) or cos (ωt ± d−x2) using the addition theorem of subtraction based on the first addition value and the second addition value. (2) a synthesis unit that outputs a synthesized value, and a first synthesized wave sin (ωt ± + X1) or cos (ωt ± d + x1) is detected based on the first composite value and the first phase ± d + x1 obtained by shifting the reference wave sin (ωt) or cos (ωt) with respect to the second composite wave sin ( The second phase ± d−x2 in which ωt ± d−x2) or cos (ωt ± d−x2) is shifted with respect to the reference wave sin (ωt) or cos (ωt) is detected based on the second composite value. A zero cross detector, and a position calculator that calculates the position of the slider from which ± d, which is a phase variation error, is removed based on the first phase ± d + x1 and the second phase ± d−x2 detected by the zero cross detector. May be included.

According to this configuration, the position of the slider in the axial direction with respect to the shaft is calculated based on the combined value that is a signal in which the shake in the vertical direction and the horizontal direction is compensated. Thus, the axial position of the slider relative to sheet Yafuto with high accuracy is calculated. Furthermore, according to this configuration, since the phase variation error caused by the temperature change in the surrounding environment can be taken into account, the position of the slider in the axial direction with respect to the shaft can be calculated with higher accuracy.

  In the magnetic position detection apparatus of the present invention, on the virtual plane, the regions partitioned by the vertical line and the horizontal line are the first region and the second region that are not adjacent to each other, and the third region and the fourth region that are not adjacent to each other. The first magnetic element has a detection surface for detecting a magnetic flux generated by the shaft, and one of the third region and the fourth region is arranged so that the perpendicular of the detection surface does not intersect the center line of the shaft. The second magnetic element is disposed in an oriented posture, and the second magnetic element has a detection surface for detecting a magnetic flux generated by the shaft, and the other of the third region and the fourth region so that the perpendicular of the detection surface does not cross the center line of the shaft May be arranged in a posture oriented toward the region side.

  According to this configuration, the first magnetic element and the second magnetic element have the third region and the fourth region (or the fourth region) so that the perpendicular (detection direction) perpendicular to the detection surface does not intersect the center line of the shaft. And the second area) are oriented in the respective orientations. When the first magnetic element and the second magnetic element take such a posture, the first magnetic element and the second magnetic element are opposite to each other in the detection direction (perpendicular to the detection surface) with respect to the magnetic flux generated by the shaft. The magnetic flux component along the direction of) is detected. At this time, when the shaft swings, the magnetic flux component detected in one magnetic element becomes stronger, and the magnetic flux component detected in the other magnetic element becomes weaker. That is, for example, when the shaft swings or bends in a direction along a straight line connecting the center line of the first magnetic element, the second magnetic element, and the shaft, the first magnetic element and the second magnetic element Therefore, the strength of the magnetic flux acting on the first magnetic element 241 and the second magnetic element 242 changes equally, but the posture of the first magnetic element 241 and the second magnetic element 242 is the same. Since they are directed in opposite directions, the magnetic flux detected by one magnetic element is weakened and the magnetic flux detected by the other magnetic element is strengthened due to the difference in the detected magnetic flux component. The addition value of the detection values detected by the first magnetic element and the second magnetic element is constant, and the slider position is detected using the constant addition value. Therefore, it is possible to compensate for the shake of the shaft 20 in all directions on the virtual plane F.

  According to the present invention, the position of the slider with respect to the shaft can be detected with high accuracy.

1 is a perspective view of a magnetic position detection device according to a first embodiment. It is sectional drawing of the magnetic position detection apparatus of FIG. It is the side view which looked at the magnetic position detection apparatus of FIG. 1 from the axial direction of the shaft. It is a block diagram which shows the function structure of the magnetic position detection apparatus of FIG. It is a figure explaining the position calculation method in the position calculation part of FIG. It is the side view which looked at the magnetic position detection device concerning a 2nd embodiment from the axial direction of a shaft. It is a block diagram which shows the function structure of the magnetic position detection apparatus of FIG. It is the side view which looked at the magnetic-type position detection apparatus which concerns on 3rd Embodiment from the axial direction of the shaft.

  Hereinafter, embodiments will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent element, and the overlapping description is abbreviate | omitted. The dimensional ratios in the drawings do not necessarily match those described.

(First embodiment)
As shown in FIG. 1, the magnetic position detection device 1 includes a slider 10, a shaft 20, a magnetic detection unit 40, and a position detection unit 70.

  The shaft 20 is disposed such that the axis (center line) CL extends in the X-axis direction, which is one horizontal direction, and the N-pole 20a and the S-pole 20b are along the axial direction (X-axis direction). Are alternately arranged. The shaft 20 is a rod-shaped member having a circular cross-sectional shape when viewed from the axial direction. The axial length of the shaft 20 can be, for example, within 4 m. The N pole 20a and the S pole 20b can be alternately arranged at a pitch of 30 mm, for example.

  The slider 10 is disposed so as to be relatively movable along the axial direction of the shaft 20. As shown in FIGS. 1 and 2, the slider 10 includes a housing 11 and a coil 13.

  The housing 11 has a loose fitting hole 11b (a hole in which the shaft 20 is disposed via a gap) in which the shaft 20 can be loosely fitted, and the axial direction relative to the shaft 20 loosely fitted in the loose fitting hole 11b. Are provided so as to be relatively movable.

  The coil 13 is accommodated in the housing 11 and is disposed at a position facing the shaft 20 that is loosely fitted in the loosely fitting hole 11b. The coil 13 is a coil row constituting a U phase, a V phase, and a W phase, and is arranged along the X-axis direction. The width of each coil in the X-axis direction is the same. In the magnetic position detection device 1, the slider 10 can move in the axial direction of the shaft 20 by the interaction between the shaft 20 and the coil 13. Specifically, when the phase of the magnetic pole pitch (the pitch between the N pole 20a and the S pole 20b) supplied to the coil 13 is 180 degrees, a three-phase current corresponding to a position having a phase difference of 120 degrees A thrust for moving the slider 10 in the X-axis direction is generated by the shaft 20 having the magnetic pole pitch. By controlling the current supplied to the coil 13 according to the position of the slider 10, the movement of the shaft 20 in the X-axis direction is controlled.

  As shown in FIG. 3, the magnetic detection unit 40 includes a first magnetic element 41, a second magnetic element 42, a third magnetic element 45, and a fourth magnetic element 46. The first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are disposed via the cap portion 30. The first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are, for example, Hall elements.

  The cap portion 30 has a loose fitting hole 30a (a hole portion in which the shaft 20 is disposed via a gap) in which the shaft 20 can be loosely fitted, similarly to the housing 11. The cap portion 30 is fixed to one end portion of the housing 11 in the axial direction of the shaft 20, and is provided so as to be relatively movable in the axial direction together with the housing 11 with respect to the shaft 20 loosely fitted in the loose fitting hole 30a. .

  As shown in FIG. 3, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are the same virtual plane orthogonal to the axial direction of the shaft 20 in the cap portion 30. It is arranged on F and is arranged around the axis CL of the shaft 20 when viewed from the axial direction of the shaft 20.

  The first magnetic element 41 and the second magnetic element 42 are in regions (R1 to R4) partitioned by a vertical line VL and a horizontal line HL passing through the axis CL of the shaft 20 on a virtual plane F orthogonal to the axial direction of the shaft 20. Of these, the first region R1 and the second region R2 that are not adjacent to each other are arranged so as to sandwich the shaft 20 therebetween. In other words, the first magnetic element 41 and the second magnetic element 42 are arranged with respect to each other with the shaft 20 interposed therebetween, and pass through the center of the shaft 20 on the above-described virtual plane F, and the horizontal line HL and the vertical line VL are They are arranged on straight lines S1 in different directions. In the present embodiment, the straight line S1 is inclined by α1 (π / 4) with respect to the vertical line VL.

  Further, the first magnetic element 41 and the second magnetic element 42 are arranged so that a direction (detection direction) orthogonal to a detection surface for detecting the magnetic flux generated by the shaft 20 faces the center of the shaft 20 on the virtual plane F. ing.

  The third magnetic element 45 and the fourth magnetic element 46 are arranged in the third region R3 and the fourth region R4 that are not adjacent to each other among the regions (R1 to R4) partitioned by the vertical line VL and the horizontal line HL on the virtual plane F. These are arranged so as to sandwich the shaft 20. In other words, the third magnetic element 45 and the fourth magnetic element 46 are arranged with the shaft 20 in between, and pass through the center of the shaft 20 on the above-described virtual plane F, and the horizontal line HL and the vertical line VL are They are arranged on straight lines S2 in different directions. In the present embodiment, the straight line S2 is inclined by α2 (π / 4) with respect to the vertical line VL. The 3rd magnetic element 45 and the 4th magnetic element 46 are arrange | positioned on the same virtual plane that the gravity center position of the detection surface in the 3rd magnetic element 45 and the 4th magnetic element 46 is located in the same virtual plane F. It means being.

  The magnetic detection unit 40 includes a first magnetic element 41, a second magnetic element 42, a third magnetic element 45, and a fourth magnetic element 46 on the virtual plane F in the circumferential direction of the shaft 20 (around the axis CL of the shaft 20). Are shifted by π / 2. More specifically, on the imaginary plane F, the fourth magnetic element 46 is disposed at a position rotated 90 degrees around the axis CL of the shaft 20 from the position where the first magnetic element 41 is disposed, and the fourth magnetic element 46 is disposed. The second magnetic element 42 is disposed at a position rotated 90 degrees around the axis CL of the shaft 20 from the position. The third magnetic element 42 is disposed at a position rotated 90 degrees around the axis CL of the shaft 20 from the position where the second magnetic element 42 is disposed. The magnetic element 45 is disposed, and the first magnetic element 41 is disposed at a position rotated 90 degrees around the axis CL of the shaft 20 from the position where the third magnetic element 45 is disposed.

  As shown in FIG. 2, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are the top surface of the housing 11 when viewed from the axial direction of the shaft 20. (Outer shape) It is arranged closer to the shaft 20 (inner side) than 11a. In other words, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are arranged on the shaft 20 side with respect to the top surface 11 a of the housing 11 in the radial direction of the shaft 20. ing. Further, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are arranged in a state shifted from the coil 13 in the axial direction of the shaft 20.

  Returning to FIG. 3, the first magnetic element 41 and the second magnetic element 42 detect a first direction component, which is a component parallel to the radial direction of the shaft 20, of the magnetic flux generated from the shaft 20. The third magnetic element 45 and the fourth magnetic element 46 detect a second direction component, which is a component parallel to the axial direction of the shaft 20 perpendicular to the radial direction of the shaft 20, out of the magnetic flux generated from the shaft 20. That is, the magnetic flux detection surfaces of the first magnetic element 41 and the second magnetic element 42 and the magnetic flux detection surfaces of the third magnetic element 45 and the fourth magnetic element 46 are orthogonal to each other.

  In the position detection unit 70 shown in FIG. 4, an addition value obtained by adding the first detection value detected by the first magnetic element 41 and the second detection value detected by the second magnetic element 42 and the third magnetic element 45 detect The position x of the slider 10 in the axial direction (X-axis direction) of the shaft 20 is calculated based on the added third value and the fourth detection value detected by the fourth magnetic element 46. The average value obtained by averaging the detection values detected by the first magnetic element 41 and the second magnetic element 42 and the average value obtained by averaging the detection values detected by the third magnetic element 45 and the fourth magnetic element 46, respectively. Thus, the position x of the slider 10 in the axial direction (X-axis direction) of the shaft 20 may be calculated.

  Next, a method of detecting the position x of the slider 10 in the position detection unit 70 will be specifically described mainly with reference to FIG. The excitation signal output unit 71 excites the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46. The excitation signal output unit 71 has a counter that counts a predetermined high-speed clock pulse, and outputs an excitation AC signal (Asin (ωt)) based on a predetermined count value. For convenience of explanation, it is assumed that the count value 0 corresponds to the 0 phase of the reference signal sin (ωt). For example, assuming that one cycle from the 0 phase to the maximum phase of the reference signal sin (ωt) is generated while the count value of the counter makes one round from 0 to the maximum value, the reference signal sin (ωt) An excitation AC signal sin (ωt) is output from the excitation signal output unit 71 with the same phase.

  At the same time, the slider 10 can move relative to the shaft 20 in the axial direction of the shaft 20. In the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46, the detected magnetic flux changes as the slider 10 moves. That is, the first magnetic element 41 and the second magnetic element 42, and the third magnetic element 45 and the fourth magnetic element 46 output the following two-phase AC signals. That is, the first magnetic element 41 and the second magnetic element 42 output an AC signal SG1 = sin (x) × sin (ωt), and the third magnetic element 45 and the fourth magnetic element 46 have an AC signal SG2 = cos (x ) × sin (ωt) is output.

  The adder 72 differentially amplifies the AC signal SG1 output from each of the first magnetic element 41 and the second magnetic element 42, and AC signal SG11 = sin (x) × sin (ωt) + sin (x) × sin ( ωt) = 2sin (x) × sin (ωt) is output. Similarly, the adder 72 differentially amplifies the AC signal SG2 output from each of the third magnetic element 45 and the fourth magnetic element 46, and AC signal SG21 = cos (x) × sin (ωt) + cos (x) * Sin ([omega] t) = 2 cos (x) * sin ([omega] t) is output.

  The phase shift unit 73 shifts the phase of the AC signal SG1 by 90 degrees and outputs the AC signal SG12 = 2sin (x) × cos (ωt).

  The synthesizer 74 synthesizes the AC signal SG12 and the AC signal SG21. Specifically, the synthesis unit 74 has an addition circuit and a subtraction circuit. The addition circuit adds the AC signal SG12 = 2sin (x) × cos (ωt) output from the phase shift unit 73 and the AC signal SG21 = 2cos (x) × sin (ωt) output from the addition unit 72. Then, an alternating current signal Y1 of SG12 + SG21 = 2sin (x) × cos (ωt) + 2cos (x) × sin (ωt) = 2sin (ωt ± d + x), which is the addition result, is output.

  The subtracting circuit subtracts the AC signal SG21 = 2cos (x) × sin (ωt) output by the adding unit 72 from the AC signal SG12 = 2sin (x) × cos (ωt) output from the phase shift unit 73. The subtraction result SG12−SG21 = 2sin (x) × cos (ωt) −2cos (x) × sin (ωt) = 2sin (ωt ± d−x) is output. Here, “± d” is a phase variation error of the AC signal that varies depending on the temperature characteristic.

  In this way, the AC signal Y1 = 2sin (ωt ± d + x) having the phase angle (+ x) shifted in the positive direction corresponding to the detection target position x and the negative direction corresponding to the same detection target position x. An AC signal Y2 = 2sin (ωt ± d−x) having a shifted phase angle (−x) is obtained.

  The zero cross detection unit 75 detects zero crosses of the AC signals Y1 and Y2 input from the addition circuit and the subtraction circuit, respectively. As a method of detecting the zero cross, for example, a point where the amplitude value of each AC signal Y1, Y2 changes from negative to positive is detected. As shown in FIG. 5, the zero-cross detection pulses detected by the zero-cross detection unit 75 are latched as latch pulses LP1 and LP2, and the count values from the counter are latched at the timings of the latch pulses LP1 and LP2, respectively.

  As described above, the counter corresponds to one cycle of the excitation AC signal (sin (ωt)), and the count value 0 corresponds to the 0 phase of the reference signal sin (ωt). For this reason, the phase shift data (first phase) D1 and the phase shift data (second phase) D2 latched by the zero cross detector 75 are respectively phase shifts of the AC signals Y1 and Y2 with respect to the reference signal sin (ωt). It corresponds to. The zero-cross detector 75 outputs the phase shift data D1 and D2 to the position calculator 76.

The position calculator 76 calculates the detection phase difference x (detection target position x). Specifically, the position calculation unit 76 considers the phase variation error of the AC signal that varies depending on the temperature characteristics, and the phase shift data D1 = ± d + x input from the zero cross detection unit 75 and the phase shift data D2 ==. An average value “(D1 + D2) / 2” with ± d−x is calculated. Thereby, the phase fluctuation error ± d is calculated.
(D1 + D2) / 2 = {(± d + x) + (± d−x)} / 2 = ± 2d / 2 = ± d

  The phase variation error “± d” calculated in this way is subtracted from one phase shift data D1. That is, since the position calculation unit 76 performs subtraction of “D1− (± d)”, D1− (± d) = ± d + x− (± d) = x, and the phase variation error “± d” is removed. Data indicating the correct detection phase difference x is obtained. As a result, data indicating the detected phase difference x (position information within the magnetic pole pitch) is obtained. Thereby, the position calculation unit 76 can calculate the absolute position of the slider 10 from the data indicating the detected phase difference x (position information within the magnetic pole pitch) and the data indicating the number of magnetic pole pitches with reference to the origin. Is possible. The number of magnetic pole pitches can be used as data at the time of position calculation, for example, by counting each time the magnetic pole pitch passes. The position calculator 76 may subtract the phase variation error “± d” from the other phase shift data D2.

  Next, functions and effects of the magnetic position detection apparatus 1 according to the first embodiment will be described. In the magnetic position detection apparatus 1 according to the first embodiment, as shown in FIG. 3, the first magnetic element 41 and the second magnetic element 42 are arranged with the shaft 20 therebetween, and on the virtual plane F. They are arranged across a horizontal line HL passing through the central axis of the shaft 20. Therefore, when the shaft 20 swings in the vertical direction with respect to the first magnetic element 41 and the second magnetic element 42, the magnetic flux detected by one magnetic element 41 (42) is weakened, and the other magnetic element 42 (41). The magnetic flux detected by is strengthened. That is, the added value of the detected values detected by the first magnetic element 41 and the second magnetic element 42 (SG11 = sin (x) × sin (ωt) + sin (x) × sin (ωt) = 2sin (x) × sin (Ωt)) becomes constant. As described above, since the position of the slider 10 is detected using a constant addition value, the vertical deflection of the shaft 20 relative to the first magnetic element 41 and the second magnetic element 42 can be compensated.

  In the magnetic position detection apparatus 1 according to the first embodiment, as shown in FIG. 3, the first magnetic element 41 and the second magnetic element 42 are arranged with the shaft 20 therebetween, and on the virtual plane F. They are arranged with a vertical line VL passing through the central axis of the shaft 20 interposed therebetween. For this reason, when the shaft 20 swings in the horizontal direction with respect to the first magnetic element 41 and the second magnetic element 42, the magnetic flux detected by one magnetic element 41 (42) is weakened, and the other magnetic element 42 (41). The magnetic flux detected by is strengthened. That is, for example, an addition value (SG1 = sin (x) × sin (ωt) + sin (x) × sin (ωt) = 2sin (x) ×) of the detection values detected by the first magnetic element 41 and the second magnetic element 42, respectively. sin (ωt)) is constant. Thus, since the position of the slider 10 is detected using a constant addition value, the horizontal deflection of the shaft 20 relative to the first magnetic element 41 and the second magnetic element 42 is compensated.

  With these actions, in the magnetic position detection device 1 of the first embodiment, both vertical and horizontal shakes of the shaft 20 with respect to the first magnetic element 41 and the second magnetic element 42 are compensated. As a result, the position of the slider 10 with respect to the shaft 20 can be detected with high accuracy.

  In the magnetic position detection apparatus 1 of the first embodiment, the slider 10 can be driven using a magnetic field generated by passing a current through the coil 13. For this reason, the slider 10 can be moved relative to the shaft 20 without separately providing a drive unit for moving the slider 10.

  In the magnetic position detection apparatus 1 of the first embodiment, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are in a state in which they are offset from the coil 13 in the axial direction. 11, the influence of magnetic flux (leakage magnetic flux) generated from the coil 13 can be reduced. Thereby, the resolution of the magnetic position detection apparatus 1 can be increased.

  In the magnetic position detection apparatus 1 of the first embodiment, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are arranged on the top surface of the housing 11 in the radial direction of the shaft 20. It is arranged closer to the shaft 20 by being arranged on the shaft 20 side than 11a. Thereby, position accuracy can be improved more.

  In the magnetic position detection apparatus 1 of the first embodiment, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are arranged on the same virtual plane F. Compared with the case where the first magnetic element to the fourth magnetic element are provided at a plurality of positions in the axial direction of the shaft 20, the arrangement space in the axial direction of the shaft 20 can be suppressed.

(Second Embodiment)
Next, the magnetic position detection apparatus 101 according to the second embodiment will be described mainly with reference to FIGS. The magnetic position detection device 101 of the second embodiment differs from the magnetic position detection device 1 of the first embodiment as shown in FIG. 6 in the magnetic position detection device 1 of the first embodiment. The third magnetic element 45 and the fourth magnetic element 46 are not provided, and the position detection method of the slider 10 in the position detection unit 170 is different. Here, the same components as those of the magnetic position detection device 1 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Only differences from the magnetic position detection device 1 of the first embodiment will be described. .

  As shown in FIG. 6, the magnetic detection unit 140 includes a first magnetic element 41 and a second magnetic element 42. The first magnetic element 41 and the second magnetic element 42 are disposed via the cap part 30. The first magnetic element 41 and the second magnetic element 42 are, for example, Hall elements. The first magnetic element 41 and the second magnetic element 42 are arranged on the same imaginary plane F orthogonal to the axial direction of the shaft 20 in the cap portion 30, and the axis CL of the shaft 20 when viewed from the axial direction of the shaft 20. Placed around.

  The first magnetic element 41 and the second magnetic element 42 are in regions (R1 to R4) partitioned by a vertical line VL and a horizontal line HL passing through the axis CL of the shaft 20 on a virtual plane F orthogonal to the axial direction of the shaft 20. Of these, the first region R1 and the second region R2 that are not adjacent to each other are arranged so as to sandwich the shaft 20 therebetween. In other words, the first magnetic element 41 and the second magnetic element 42 are arranged with respect to each other with the shaft 20 interposed therebetween, and pass through the center of the shaft 20 on the above-described virtual plane F, and the horizontal line HL and the vertical line VL are They are arranged on straight lines S1 in different directions. In the present embodiment, the straight line S1 is inclined by α1 (π / 4) with respect to the vertical line VL.

  The first magnetic element 41 and the second magnetic element 42 pass through the axis CL of the shaft 20 on the imaginary plane F described above, and the straight line S2 (with respect to the vertical line VL) in a direction different from the horizontal line HL and the vertical line VL. [Alpha] 2 ([pi] / 4).

  The first magnetic element 41 and the second magnetic element 42 are arranged so that the direction orthogonal to the magnetic flux detection surface faces the center of the shaft 20 on the virtual plane F. The first magnetic element 41 and the second magnetic element 42 detect a first direction component, which is a component parallel to the radial direction of the shaft 20, of the magnetic flux generated from the shaft 20.

  The position detection unit 170 shown in FIG. 7 is based on the addition value obtained by adding the first detection value detected by the first magnetic element 41 and the second detection value detected by the second magnetic element 42. The position x of the slider 10 in (X axis direction) is calculated. The slider 10 in the axial direction (X-axis direction) of the shaft 20 is based on an average value obtained by averaging the first detection value detected by the first magnetic element 41 and the second detection value detected by the second magnetic element 42. The position x may be calculated.

  Next, a method for detecting the position x of the slider 10 in the position detection unit 170 will be specifically described mainly with reference to FIG. The excitation signal output unit 171 excites the coil 13 accommodated in the housing 11. The excitation signal output unit 171 outputs an AC signal for excitation (Asin (ωt)).

  At the same time, the slider 10 can move relative to the shaft 20 in the axial direction of the shaft 20. The magnetic flux detected by the first magnetic element 41 and the second magnetic element 42 changes as the slider 10 moves. That is, the first magnetic element 41 and the second magnetic element 42 output the AC signal shown below. That is, the first magnetic element 41 and the second magnetic element 42 output an AC signal C = sin (x) × sin (ωt).

  The adder 172 differentially amplifies the AC signal B output from each of the first magnetic element 41 and the second magnetic element 42, and AC signal C1 = sin (x) × sin (ωt) + sin (x) × sin ( ωt) = 2sin (x) × sin (ωt) is output.

  The AD (analog / digital) converter 173 extracts sin (x) from the AC signal C <b> 1 input from the adder 172 and performs AD conversion.

  The direction determination unit 174 determines the moving direction of the slider 10 with reference to past detection information stored in the shift register.

  The position calculation unit 175 calculates the position of the slider 10 based on the result determined by the direction determination unit 174 and the data output from the AD (analog / digital) conversion unit 173. Specifically, the absolute position of the slider 10 is detected from position information in the magnetic pole pitch and information on the number of magnetic pole pitches.

  Next, functions and effects of the magnetic position detection apparatus 101 according to the second embodiment will be described. In the magnetic position detection device 101 of the second embodiment, as in the magnetic position detection device 1 of the first embodiment, as shown in FIG. 6, the first magnetic element 41 and the second magnetic element 42 are mutually connected. In addition to being arranged with the shaft 20 in between, the horizontal line HL and the vertical line VL passing through the central axis of the shaft 20 on the virtual plane F are arranged. Therefore, when the shaft 20 swings in the vertical direction and the horizontal direction with respect to the first magnetic element 41 and the second magnetic element 42, even if the magnetic flux detected by one magnetic element 41 (42) is weakened, The magnetic flux detected by the magnetic element 42 (41) is strengthened. That is, the addition value of the detection values detected by the first magnetic element 41 and the second magnetic element 42 (SG1 = sinx × sin (ωt) + sin (x) × sin (ωt) = 2sin (x) × sin (ωt) ) Is constant. Thus, since the position of the slider 10 is detected using the constant addition value A1, the vertical and horizontal shakes of the shaft 20 with respect to the first magnetic element 41 and the second magnetic element 42 can be compensated. As a result, the position of the slider 10 with respect to the shaft 20 can be detected with high accuracy.

  In addition, in the magnetic position detection device 101 of the second embodiment, the other components common to the magnetic position detection device 1 of the first embodiment obtain the same effects as the magnetic position detection device 1 of the first embodiment. be able to.

(Third embodiment)
Next, a magnetic position detection apparatus 201 according to the third embodiment will be described mainly with reference to FIG. Compared with the magnetic position detection device 1 of the first embodiment, the magnetic position detection device 201 of the third embodiment has a first magnetic element 241, a second magnetic element 242, a third magnetic element 245, and a fourth magnetic element. The difference is in the posture in which the element 246 is arranged. Here, the same components as those of the magnetic position detection device 1 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Only differences from the magnetic position detection device 1 of the first embodiment will be described. .

  That is, in the magnetic detection unit 40 of the first embodiment, the first magnetic element 41 and the second magnetic element 42 are arranged such that the direction orthogonal to the magnetic flux detection surface is directed to the center of the shaft 20 on the virtual plane F. As described with reference to the arrangement example, in the magnetic detection unit 240 of the third embodiment, the first magnetic element 241 and the second magnetic element 242 do not face the center of the shaft 20 on the virtual plane F. Be placed. In other words, the first magnetic element 241 is in such a posture that the perpendicular perpendicular to the detection surfaces of the first magnetic element 241 and the second magnetic element 242 does not intersect the axis (center line) CL of the shaft 20 on the virtual plane F. And the second magnetic element 242 is disposed. The first magnetic element 241 is arranged so that the perpendicular of the detection surface is directed to the third region R3 side, and the second magnetic element 242 is arranged so that the perpendicular of the detection surface is directed to the fourth region R4 side. Is done.

  Specifically, the first magnetic element 241 is located in a direction perpendicular to the straight line S1 (tangential direction of the outer peripheral surface of the shaft) with respect to the straight line S1 inclined by α1 (π / 4) with respect to the vertical line VL. By being arranged at a position that is fixedly offset, the posture is directed to the third region R3 side so that the perpendicular perpendicular to the detection surface does not intersect the axis of the shaft 20. Similarly, the second magnetic element 242 is a position offset by a predetermined amount in a direction orthogonal to the straight line S1 (tangential direction of the outer peripheral surface of the shaft) and a direction opposite to the offset direction of the first magnetic element 41 with respect to the straight line S1. With the arrangement, the vertical direction perpendicular to the detection surface is oriented toward the fourth region R4 side so as not to intersect the axis of the shaft 20. At this time, it is desirable that the first magnetic element 241 and the second magnetic element 242 have the same offset amount.

  Similarly to the first magnetic element 241 and the second magnetic element 242, the third magnetic element 245 and the fourth magnetic element 246 are straight lines with reference to a straight line S2 inclined by α2 (π / 4) with respect to the vertical line VL. Each is offset by a predetermined amount in the orthogonal direction of S2.

  Next, functions and effects of the magnetic position detection device 201 according to the third embodiment will be described. In the magnetic position detection device 201 of the third embodiment, as shown in FIG. 8, the first magnetic element 241 and the second magnetic element 242 are perpendicular to the detection surface (detection direction) is the axis CL of the shaft 20. So that the third region R3 side and the fourth region R4 side are directed to each other so that they do not cross each other. When the first magnetic element 241 and the second magnetic element 242 take such a posture, the detection directions in which the first magnetic element 241 and the second magnetic element 242 are opposite to each other with respect to the magnetic flux generated by the shaft 20. A magnetic flux component along the direction of the normal of the detection surface is detected. At this time, when the shaft swings with respect to the first magnetic element 241 and the second magnetic element 242, the magnetic flux component detected in one magnetic element becomes stronger and the magnetic flux component detected in the other magnetic element becomes weaker. . That is, for example, when the shaft swings or bends in the direction along the straight line S2, the shaft moves away from the first magnetic element 241 and the second magnetic element 242 by an equal distance. The strength of the magnetic flux acting on 241 and the second magnetic element 242 changes equally, but since the postures of the first magnetic element 241 and the second magnetic element 242 are in opposite directions, the detected magnetic flux component Due to the difference, the magnetic flux detected by one magnetic element 241 (242) is weakened, and the magnetic flux detected by the other magnetic element 242 (241) is strengthened. The addition value of the detection values detected by the first magnetic element 241 and the second magnetic element 242 is constant, and the position of the slider 10 is detected using the constant addition value. Therefore, the shake of the shaft 20 in the direction along the straight line S2 (the direction perpendicular to the line connecting the first magnetic element 241, the second magnetic element 242, and the axis CL of the shaft 20) can be compensated for on the virtual plane F. It is possible to compensate for the deflection of the shaft 20 in all directions.

  The magnetic position detection device according to the first to third embodiments has been described above, but the present invention is not limited to the above embodiment. For example, in the magnetic position detection apparatus 1 of the first embodiment, the combining unit 74 in the position detection unit 70 adds the addition from the first addition value (AC signal SG11) and the second addition value (AC signal SG21). The first synthesized wave (AC signal Y1) is output based on the theorem, and the second synthesized wave (AC signal Y2) is output based on the subtraction additive theorem. It is not limited. For example, the synthesis unit of the position detection unit 70 outputs a synthesized value corresponding to the synthesized wave sin (ωt ± x) or cos (ωt ± x) based on the addition theorem from the first addition value and the second addition value. Then, the zero cross detection unit detects the phase x in which the synthesized wave sin (ωt ± x) or cos (ωt ± x) is shifted with respect to the reference wave sin (ωt) or cos (ωt) based on the synthesized value. May be.

  In the magnetic position detection device 1 of the first embodiment and the magnetic position detection device 201 of the third embodiment, a straight line S1 rotated 45 degrees from a vertical line VL passing through the axis CL of the shaft 20 on the virtual plane F. As an example, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element 46 are described by being arranged in a state shifted by π / 2 around the axis CL. However, the present invention is not limited to this. For example, the first magnetic element 41, the second magnetic element 42, the third magnetic element 45, and the fourth magnetic element are based on a straight line rotated 60 degrees from the vertical line VL passing through the axis CL of the shaft 20 on the virtual plane F. 46 may be arranged in a state shifted by π / 2 around the axis CL.

  In the magnetic position detection device 1 of the first embodiment and the magnetic position detection device 201 of the third embodiment, the first magnetic element 41 (241), the second magnetic element 42 (242), and the third magnetic element 45 are used. (245) and the fourth magnetic element 46 (246) have been described by taking an example in which they are arranged in a state of being shifted by an equal angle around the axis CL on the virtual plane F, but the present invention is limited to this. It is not a thing. For example, the first magnetic element 41 (241), the second magnetic element 42 (242), the third magnetic element 45 (245), and the fourth magnetic element 46 (246) are equiangular around the axis CL on the virtual plane F. It does not have to be shifted one by one.

  In the magnetic position detection apparatus 1 of the second embodiment, the first magnetic element 141 and the second magnetic element are on the straight line S1 rotated 45 degrees from the vertical line VL passing through the axis CL of the shaft 20 on the virtual plane F. Although an example in which 142 is arranged has been described, the present invention is not limited to this. For example, the first magnetic element 141 and the second magnetic element 142 may be arranged on a straight line rotated 60 degrees from the vertical line VL passing through the axis CL of the shaft 20 on the virtual plane F.

  In the magnetic position detection device 1 of the first embodiment and the magnetic position detection device 201 of the third embodiment, the first magnetic element 41 (241) and the second magnetic element 42 (242) are in the first region R1. The third magnetic element 45 (245) and the fourth magnetic element 46 (246) are disposed in the third region R3 and the fourth region R4, respectively. However, the present invention is not limited to this. For example, the first magnetic element 41 (241) and the second magnetic element 42 (242) are disposed in the first region R1 and the second region R2, respectively, and the third magnetic element 45 (245) and the fourth magnetic element 46 ( 246) are disposed in the first region R1 and the second region R2, respectively, and the third magnetic element 45 and the region where the first magnetic element 41 (241) and the second magnetic element 42 (242) are disposed, respectively. (245) and the region where the fourth magnetic element 46 (246) is disposed may be the same.

  In the magnetic position detection device 201 of the third embodiment, the first magnetic element 241 is arranged so that the perpendicular of the detection surface is directed to the third region R3 side, and the second magnetic element 242 is perpendicular to the detection surface. Is arranged so as to be directed to the fourth region R4 side, but the first magnetic element 241 is arranged to be directed to the fourth region R4 side, and the second magnetic element 242 is directed to the third region R3 side. May be arranged.

  In the magnetic position detection apparatus 201 of the third embodiment, the first magnetic element 241, the second magnetic element 242, the third magnetic element 245, and the fourth magnetic element 246 are offset with respect to the straight line S1 or the straight line S2. However, for example, even if the first magnetic element 241 and the second magnetic element 242 are offset with respect to the straight line S1, the third magnetic element 245 and the fourth magnetic element 246 are arranged on the straight line S2 without being offset. Good.

  In the magnetic position detection device 1 of the first embodiment and the magnetic position detection device 201 of the third embodiment, the first magnetic element 41 (241) and the second magnetic element 42 (242) are in relation to the straight line S1. The third magnetic element 45 (245) and the fourth magnetic element 46 (246) are offset with respect to the straight line S2, but may be offset with reference to a vertical line or a horizontal line, for example. Similarly, in the second embodiment, the first magnetic element 141 and the second magnetic element 142 may be offset with respect to the straight line S1, or may be offset with reference to a vertical line or a horizontal line.

  In the magnetic position detection device 1 of the first embodiment and the magnetic position detection device 201 of the third embodiment, four magnetic elements are used, and in the magnetic position detection device 101 of the second embodiment, Two magnetic elements are used, but at least two magnetic elements may be used, and three or more magnetic elements may be used.

  The present invention can also be applied to an R / D conversion method or an A / D conversion method in position conversion in slider position detection.

  DESCRIPTION OF SYMBOLS 1,101,201 ... Magnetic-type position detection apparatus, 10 ... Slider, 11 ... Housing | casing, 11a ... Top surface, 11b ... Free fitting hole (hole part), 13 ... Coil, 20 ... Shaft, 30 ... Cap part, 40 , 140, 240... Magnetic detector, 41, 141, 241... First magnetic element, 42, 142, 242... Second magnetic element, 45, 245... Third magnetic element, 46, 246. ... Position detecting unit, 71 ... Excitation signal output unit, 72 ... Addition unit, 73 ... Phase shift unit, 74 ... Composition unit, 75 ... Zero cross detection unit, 76 ... Position calculation unit, 140 ... Magnetic detection unit, 170 ... Position detection 171 ... excitation signal output unit, 172 ... adder, 173 ... AD converter, 174 ... direction discriminator, F ... virtual plane, HL ... horizontal line, VL ... vertical line, R1 ... first region, R2 ... second Region, R3 ... Third region, R4 ... Fourth Frequency, CL ... axis (center line).

Claims (7)

A shaft extending in the horizontal direction and having N and S poles arranged alternately in the axial direction;
A slider arranged to be relatively movable in the axial direction with respect to the shaft;
A magnetic detection unit that is attached to the slider and includes a first magnetic element , a second magnetic element , a third magnetic element, and a fourth magnetic element that detect magnetic flux generated by the shaft;
A position detection unit that detects a position of the slider with respect to the shaft based on detection values of the first magnetic element , the second magnetic element , the third magnetic element, and the fourth magnetic element ;
The first magnetic element and the second magnetic element include a first area and a first area that are not adjacent to each other among areas partitioned by a vertical line and a horizontal line passing through a center line of the shaft on a virtual plane orthogonal to the axial direction. The two regions are arranged so as to sandwich the shaft ,
The third magnetic element and the fourth magnetic element sandwich the shaft between a third area and a fourth area that are not adjacent to each other among the areas partitioned by the vertical line and the horizontal line on the virtual plane. Are arranged respectively.
The first magnetic element and the second magnetic element detect a first direction component of the magnetic flux,
The magnetic position detection device, wherein the third magnetic element and the fourth magnetic element detect a second direction component of the magnetic flux orthogonal to the first direction component. The slider includes a casing having a hole portion in which the shaft is disposed via a gap, and a coil accommodated in the casing.
The slider is movable in the axial direction by magnetic interaction between the shaft and the coil,
2. The magnetic position detection device according to claim 1, wherein the first magnetic element and the second magnetic element are attached to the housing in a state of being shifted from the coil in the axial direction.   The magnetic position detection device according to claim 2, wherein the first magnetic element and the second magnetic element are disposed inside an outer shape of the housing when viewed from the axial direction. The first magnetic element, the second magnetic element, the third magnetic element, and the fourth magnetic element are arranged in a state shifted by π / 2 around the center line . The magnetic position detection device according to any one of claims. The position detector is
By adding the detection values of the first magnetic element and the second magnetic element, a first addition value corresponding to the first triangular wave sin (x) × sin (ωt) is output, and the third An adder that outputs a second added value corresponding to the second triangular wave cos (x) × sin (ωt) by adding the detected values of the magnetic element and the fourth magnetic element;
Based on the first addition value and the second addition value, a synthesis unit that outputs a synthesized value corresponding to the synthesized wave sin (ωt ± x) or cos (ωt ± x) using an addition theorem;
A zero-cross detector that detects a phase x in which the combined wave sin (ωt ± x) or cos (ωt ± x) is shifted with respect to a reference wave sin (ωt) or cos (ωt) based on the combined value;
The zero-cross detecting unit based on the phase x of the detecting comprises: a position calculation unit for calculating the position of the slider, the magnetic position detecting apparatus according to any one of claims 1 to 4. The position detector is
By adding the detection values of the first magnetic element and the second magnetic element, a first addition value corresponding to the first triangular wave sin (x) × sin (ωt) is output, and the third An adder that outputs a second added value corresponding to the second triangular wave cos (x) × sin (ωt) by adding the detected values of the magnetic element and the fourth magnetic element;
Based on the first addition value and the second addition value, the first synthesis value corresponding to the first synthesis wave sin (ωt ± d + x1) or cos (ωt ± d + x1) is output using the addition theorem of addition. Based on the first addition value and the second addition value, the second corresponding to the second composite wave sin (ωt ± d−x2) or cos (ωt ± d−x2) using the addition theorem of subtraction. A synthesis unit for outputting a synthesized value;
Based on the first composite value, the first phase ± d + x1 obtained by shifting the first composite wave sin (ωt ± d + x1) or cos (ωt ± d + x1) with respect to the reference wave sin (ωt) or cos (ωt). Second phase ± d−x2 in which the second synthesized wave sin (ωt ± d−x2) or cos (ωt ± d−x2) is shifted with respect to the reference wave sin (ωt) or cos (ωt) Is detected based on the second combined value,
A position calculation unit that calculates a position of the slider from which ± d that is a phase variation error is removed based on the first phase ± d + x1 and the second phase ± d−x2 detected by the zero-cross detection unit. The magnetic position detection device according to any one of claims 1 to 4 . On the virtual plane, the region partitioned by the vertical line and the horizontal line is composed of the first region and the second region that are not adjacent to each other, and the third region and the fourth region that are not adjacent to each other,
The first magnetic element has a detection surface for detecting a magnetic flux generated by the shaft, and one of the third region and the fourth region is arranged so that the perpendicular of the detection surface does not intersect the center line of the shaft. Arranged in a posture oriented toward the area side,
The second magnetic element has a detection surface for detecting a magnetic flux generated by the shaft, and the other of the third region and the fourth region is arranged so that the perpendicular of the detection surface does not intersect the center line of the shaft. are arranged in a directed posture area side, magnetic position detector according to any one of claims 1-6.

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