Position sensor

Abstract

This position sensor comprises a guide member including a cylinder portion, a flexible printed board having a detecting part disposed so as to surround the cylinder portion, and a shaft member that rotates along the cylinder portion or moves in a straight line along the cylinder portion. The detecting part includes an oscillating coil and a receiving coil for receiving a magnetic field generated by the oscillating coil. The shaft member has a configuration in which a magnetic or electrically conductive recessed portion is formed in a side surface facing the detecting part with the cylinder portion interposed therebetween. Alternatively, the shaft member has a configuration including: a shaft main body in which a recessed portion is formed in a side surface facing the detecting part with the cylinder portion interposed therebetween; and a magnetic or electrically conductive member disposed inside the recessed portion so as to be located further inward than a side surface of the shaft main body. If this member is magnetic, the shaft main body is made from a non-magnetic material. If the member is electrically conductive, the shaft main body has insulating properties.

Description

Position Sensor

[0001] The present disclosure relates to position sensors, and more particularly to position sensors that use magnetic fields to detect rotational or linear movement of an object.

[0002] A position sensor that detects the rotation of a rotating body using a magnetic field is known from Japanese Patent Application Laid-Open No. 2003-222294.

[0003] In this type of position sensor, a magnetic body is provided on the surface of a rotating body, and a flexible printed circuit board is arranged to surround the rotating body. The flexible printed circuit board is arranged to directly face the rotating body with a gap between it and the magnetic body (rotating body). An oscillator coil and a receiver coil are formed on the flexible printed circuit board, and the position of the rotating body is detected by the receiver coil detecting changes in the magnetic field generated by the oscillator coil depending on the position of the magnetic body.

[0004] U.S. Patent Application Publication No. 2020 / 0116529

[0005] In the conventional position sensor, the magnetic body protrudes from the surface of the rotating body, so when the flexible printed circuit board directly surrounds the rotating body, a gap is formed between the flexible printed circuit board and the rotating body.

[0006] Furthermore, there is a risk that the wobble of the rotating body will cause contact between the magnetic body and the flexible printed circuit board, resulting in malfunctions. Therefore, to avoid contact between the magnetic body and the flexible printed circuit board, it is necessary to provide a large gap between the magnetic body and the flexible printed circuit board.

[0007] Therefore, conventional position sensors tend to be large in size to avoid malfunctions.

[0008] The position sensor of the present disclosure can suppress an increase in size and the occurrence of malfunctions.

[0009] The position sensor disclosed herein includes a guide member having a cylindrical portion, a flexible printed circuit board having a detection portion arranged to surround the cylindrical portion, and a shaft member that rotates or moves linearly along the cylindrical portion. The detection portion includes an oscillator coil and a receiver coil that receives a magnetic field generated by the oscillator coil. The shaft member has a magnetic recess formed on a side surface facing the detection portion across the cylindrical portion. Alternatively, the shaft member has a shaft main body having a recess formed on a side surface facing the detection portion across the cylindrical portion, and a separate magnetic member disposed within the recess so as to be located inward of the side surface of the shaft main body. The shaft main body is made of a non-magnetic material.

[0010] The recess of the shaft member may be conductive instead of magnetic. In this case, the recess may be either magnetic or non-magnetic, the shaft body has insulating properties, and the separate member has conductive properties instead of magnetic properties. The shaft body and the separate member may be either magnetic or non-magnetic.

[0011] The magnetic field received by the receiving coil is changed by the magnetic or conductive recess, or by a separate member placed in the recess. In addition, a cylindrical portion of the guide member is interposed between the detection portion of the flexible printed circuit board and the shaft member.

[0012] Since the position sensor of the present disclosure is configured as described above, it is possible to prevent malfunctions while preventing the sensor from becoming larger by separating the detection portion of the flexible printed circuit board from the shaft member, i.e., by increasing the gap between the detection portion and the shaft member.

[0013] FIG. 1 is a perspective view of a position sensor according to the present disclosure. FIG. 2 is a perspective view of a shaft member of the position sensor shown in FIG. 1. FIG. 3 is a rear view of the shaft member of the position sensor shown in FIG. 1. FIG. 4 is a cross-sectional view of the shaft member of the position sensor shown in FIG. 3 taken along line IV-IV. FIG. 5 is a schematic diagram of a flexible printed circuit board of the position sensor shown in FIG. 1. FIG. 6 is a rear view of the position sensor according to the present disclosure. FIG. 7 is a cross-sectional view of the position sensor shown in FIG. 6 taken along line VII-VII. FIG. 8 is a perspective view of yet another position sensor according to the present disclosure. FIG. 9 is a perspective view of the shaft member of the position sensor shown in FIG. 8. FIG. 10 is a schematic diagram of a detection portion of the flexible printed circuit board of the position sensor shown in FIG. 8. FIG. 11A is a perspective view of a shaft member of yet another position sensor according to the present disclosure. FIG. 11B is a rear view of the shaft member shown in FIG. 11A. FIG. 11C is a cross-sectional view of the shaft member shown in FIG. 11B taken along line XIC-XIC. FIG. 11D is an exploded perspective view of the shaft member shown in FIG. 11A. FIG. 12A is a perspective view of yet another shaft member of a position sensor according to the present disclosure. FIG. 12B is a rear view of the shaft member shown in FIG. 12A. FIG. 12C is a cross-sectional view of the shaft member shown in FIG. 12B taken along line XIIC-XIIC. FIG. 12D is a perspective view of another member of the shaft member shown in FIG. 12A. FIG. 13A is a perspective view of yet another shaft member of a position sensor according to the present disclosure. FIG. 13B is a rear view of the shaft member shown in FIG. 13A. FIG. 13C is a cross-sectional view of the shaft member shown in FIG. 13B taken along line XIIIC-XIIIC. FIG. 13D is a perspective view of another member of the shaft member shown in FIG. 13A. FIG. 14 is a perspective view of yet another shaft member of a position sensor according to the present disclosure. FIG. 15A is a perspective view of yet another position sensor according to the present disclosure. FIG. 15B is a rear view of the position sensor shown in FIG. 15A. FIG. 15C is a cross-sectional view of the position sensor shown in FIG. 15B taken along line XVC-XVC. FIG. 16 is a cross-sectional view of yet another position sensor according to the present disclosure.

[0014] Hereinafter, a position sensor according to an embodiment of the present invention will be described. Note that the embodiments disclosed below are all illustrative and merely represent examples of the present invention. In addition, to facilitate understanding by those skilled in the art, detailed descriptions of well-known matters and redundant descriptions of substantially identical configurations may be omitted.

[0015] In addition, to facilitate understanding of the embodiments, directions may be indicated using expressions such as up / down, left / right, and front / back. These directions are used merely for convenience and are not determined by actual applications. Here, up and down refer to directions perpendicular to left and right and front and back. Furthermore, left and right refer to directions perpendicular to front and back.

[0016] 1, 2, and 5, a configuration of a position sensor 100 according to an embodiment of the present disclosure will be described. The position sensor 100 includes a guide member 10, a flexible printed circuit board 20, and a shaft member 30.

[0017] The guide member 10 has a cylindrical portion 11. The cylindrical portion 11 has a cylindrical shape that surrounds a central axis C11 that extends in the up-down direction and extends along the central axis C11. The flexible printed circuit board 20 has a detection portion 21. The detection portion 21 is arranged so as to surround the cylindrical portion 11. More specifically, it is bent along the cylindrical portion 11. The detection portion 21 is formed with an oscillator coil 21a and receiver coils 21b and 21c. The receiver coils 21b and 21c are configured to receive a magnetic field (AC magnetic field) generated by the oscillator coil 21a.

[0018] The shaft member 30 is made of a magnetic material and has a recess 31 formed on a side surface that faces the detection portion 21 across the cylindrical portion 11. The shaft member 30 is configured to be rotatable.

[0019] Here, the magnetic material does not mean that the shaft member 30 is necessarily made of only a magnetic material, and for example, the shaft member 30 may be made of a mixture of a magnetic material and a non-magnetic material or a joint of a magnetic material and a non-magnetic material, and may have magnetism at least in the portion facing the detection part 21. Furthermore, being rotatable includes rotation in the clockwise or counterclockwise direction or both, and rotation of the shaft member 30 around the central axis C11 (of the cylindrical portion 11) through an angle of less than 360 degrees.

[0020] The shaft member 30 may be conductive instead of magnetic. In this case, the shaft member 30 may be either magnetic or non-magnetic. The shaft member 30 does not need to be made of only a conductor. For example, the shaft member 30 may be made of a mixture of a conductor and an insulator or a joint of a conductor and an insulator, and may be conductive at least in the portion facing the detection portion 21.

[0021] The operation of the position sensor 100 will now be described. When the shaft member 30 rotates, the recessed portion 31 also rotates. When the recessed portion 31 moves within the detection portion 21, a change occurs in the magnetic field of the oscillator coil 21a received by the receiving coils 21b and 21c. In other words, when the recessed portion 31 moves within the detection portion 21, a change occurs in the voltage generated in the receiving coils 21b and 21c. From this change in voltage, the position sensor 100 can detect the amount of rotation (rotation angle), rotation speed, rotation direction, etc. of the shaft member 30.

[0022] In this way, in the position sensor 100, the recess 31 that changes the magnetic field received by the receiving coils 21 b and 21 c is formed in the shaft member 30. In other words, changes in the diameter of the shaft member 30 are suppressed. In addition, the cylindrical portion 11 of the guide member 10 is interposed between the detection portion 21 of the flexible printed circuit board 20 and the shaft member 30.

[0023] Therefore, the position sensor 100 can provide a position sensor that can prevent the detection portion 21 of the flexible printed circuit board 20 from becoming too large by separating the detection portion 21 and the shaft member 30 significantly (by providing a large gap between the detection portion 21 and the shaft member 30), while also preventing malfunctions caused by contact between the shaft member 30 and the detection portion 21.

[0024] It should be noted that the shaft member 30 itself does not need to be magnetic, at least in the portion facing the detection portion 21. For example, the shaft member 30 may be made of an insulating non-magnetic material, and in this embodiment, may be a resin member made of resin. In this case, a separate magnetic member may be provided within the recess 31. Examples of magnetic materials or separate members include iron oxide, chromium oxide, cobalt, ferrite, and oxide. This configuration will be described later.

[0025] Furthermore, if the separate member is conductive instead of magnetic, the shaft member 30 itself does not need to be conductive, at least in the portion facing the detection portion 21. For example, the shaft member 30 may be a resin member made of resin. In this case, a separate conductive member may be provided within the recess 31. Examples of conductors and separate members include metals such as iron, aluminum, copper, and SUS. This configuration will be described later.

[0026] Furthermore, although the movement of the shaft member 30 has been described as a rotational movement, the shaft member 30 may also move linearly. Here, linear movement refers to, for example, movement along the up-down direction, movement along the left-right direction, or movement along the front-rear direction.

[0027] 1 to 5, the position sensor 100 will be described in more detail. The position sensor 100 includes a guide member 10, a flexible printed circuit board 20, and a shaft member 30.

[0028] The guide member 10 has a cylindrical portion 11 and a base portion 12. The guide member 10 is a resin molded product, and the cylindrical portion 11 and the base portion 12 are integrally formed. The cylindrical portion 11 protrudes upward from the base portion 12.

[0029] The cylindrical portion 11 has an inner wall portion 11a and an outer wall portion 11b. A gap is formed between the inner wall portion 11a and the outer wall portion 11b. A flexible printed circuit board 20 (a detection portion 21, described later) is disposed in the gap formed between the inner wall portion 11a and the outer wall portion 11b. The upper end of the inner wall portion 11a is connected to the upper end of the outer wall portion 11b.

[0030] The inner wall portion 11a is disposed closer to the shaft member 30 (recess 31) than the outer wall portion 11b. The inner wall portion 11a is formed in an annular shape so as to surround the entire circumference of the shaft member 30.

[0031] The outer wall portion 11b is provided so as to surround (cover) the inner wall portion 11a. The outer wall portion 11b has a slit 13 extending in the vertical direction. The inner wall portion 11a is exposed through the slit 13.

[0032] The guide member 10 can restrict movement of the flexible printed circuit board 20 (detection portion 21) by disposing the flexible printed circuit board 20 (detection portion 21) between the inner wall portion 11 a and the outer wall portion 11 b. Furthermore, by providing the slit 13 in the outer wall portion 11 b, the flexible printed circuit board 20 (detection portion 21) can be easily disposed between the inner wall portion 11 a and the outer wall portion 11 b.

[0033] The flexible printed circuit board 20 has a detection section 21, a control section 22, and a connection section 23. The flexible printed circuit board 20 is a laminate in which a plurality of insulating layers are stacked, and wiring (circuits) is formed between the layers. The detection section 21, the control section 22, and the connection section 23 are integrated.

[0034] The detection portion 21 is bent along the tubular portion 11 and is disposed so as to surround the tubular portion 11. Here, the detection portion 21 is disposed so as to surround approximately half of the tubular portion 11. In other words, the detection portion 21 is configured so as to surround an area of ​​approximately 180 degrees of the shaft member 30.

[0035] The detection portion 21 is formed with an oscillator coil 21a, a receiver coil 21b, and a receiver coil 21c. The receiver coil 21b and the receiver coil 21c receive the magnetic field generated by the oscillator coil 21a. The oscillator coil 21a is electrically insulated from the two receiver coils 21b and 21c via an insulating layer. The receiver coil 21b is also electrically insulated from the receiver coil 21c via an insulating layer. When viewed from above, the two receiver coils 21b and 21c are each located in an area more inward than the oscillator coil 21a.

[0036] The receiver coil 21b has a spiral-shaped portion 21b1 having a sine wave shape. The receiver coil 21c has a spiral-shaped portion 21c1 having a sine wave shape. Here, the relationship between the shapes of the spiral-shaped portion 21b1 and the spiral-shaped portion 21c1 is roughly that of a sine wave and a cosine wave. Note that, when viewed from above, the spiral-shaped portion 21b1 and the spiral-shaped portion 21c1 are not short-circuited within the spiral-shaped portion 21b1 and the spiral-shaped portion 21c1. In other words, the two receiver coils 21b and 21c are formed across multiple insulating layers via through holes that penetrate the insulating layers.

[0037] The magnetic field generated by the transmitter coil 21a interlinks with the receiver coils 21b and 21c. Rotation of the shaft member 30 causes the recess 31 to move left and right and front and rear relative to the receiver coils 21b and 21c, as shown in FIG. 5 . Because the recess 31 has locally low permeability or conductivity, the magnetic field interlinking the portions of the receiver coils 21b and 21c facing the recess 31 changes. By providing two receiver coils 21b and 21c with spiral-shaped portions 21b1 and 21c1 that exhibit a sine wave and cosine wave relationship, a voltage ratio can be obtained from the outputs of the two receiver coils. This voltage ratio changes as the interlinking magnetic field changes. The position sensor 100 can detect the position of the recess 31, i.e., the angular position of the recess 31, with high detection accuracy based on this voltage ratio.

[0038] Furthermore, the detection portion 21 is disposed between the inner wall portion 11a and the outer wall portion 11b. More specifically, the detection portion 21 has a central portion 21d, a left portion 21e, and a right portion 21f. The left portion 21e and the right portion 21f are disposed between the inner wall portion 11a and the outer wall portion 11b. The central portion 21d is disposed so as to be exposed from the slit 13. Here, the left portion 21e is located to the left of the central portion 21d, and the right portion 21f is located to the right of the central portion 21d. In other words, the left portion 21e and the right portion 21f are connected to the central portion 21d and are connected via the central portion 21d.

[0039] The connection portion 23 connects the central portion 21d of the detection portion 21 to the control portion 22. The width of the connection portion 23 (the distance between the right end and the left end) is narrower (smaller) than the widths of the detection portion 21 and the control portion 22. A wiring line that connects the oscillator coil 21a and the two receiver coils 21b and 21c runs through the connection portion 23. The wiring line 23a passes through the central portion 21d and the right portion 21f and is connected to the oscillator coil 21a and the two receiver coils 21b and 21c.

[0040] The control unit 22 is provided with a control circuit 22a. The control unit 22 is disposed on the base 12. The control circuit 22a is connected to the lead wiring 23a. That is, the control circuit 22a is connected to the oscillator coil 21a and the two receiver coils 21b and 21c via the control circuit 22a. The control circuit 22a may be, for example, an integrated circuit (IC). The control circuit 22a converts the output voltage ratio of the two receiver coils 21b and 21c into a linear voltage and outputs it.

[0041] Here, the width of connection portion 23 (the distance between the right end and the left end) is narrower (smaller) than the width of detection portion 21 and the width of control portion 22, so it is possible to prevent heat from detection portion 21 from transferring to control portion 22. Therefore, it is possible to place heat-sensitive components (such as ICs) in control portion 22.

[0042] The shaft member 30 is configured to be rotatable. The shaft member 30 is made of a magnetic material and has two recesses 31 formed on a side surface facing the detection part 21 across the inner wall part 11a of the cylindrical part 11. The two recesses 31 are formed to face each other with the vicinity of the center of the shaft member in between.

[0043] The vertical length of the recessed portions 31 is longer than the horizontal length. The distance between the two recessed portions 31 is set so that when one recessed portion 31 faces the spiral-shaped portion 21b1, the other recessed portion 31 does not face the spiral-shaped portion 21b1. More preferably, the distance between the two recessed portions 31 is set so that when one recessed portion 31 faces the spiral-shaped portion 21c1, the other recessed portion 31 does not face the spiral-shaped portion 21c1.

[0044] More preferably, the distance between the two recesses 31 is set so that only one recess 31 faces each of the spiral-shaped portions 21b1 and 21c1.

[0045] The distance between the recesses 31 is the distance in the circumferential direction (rotational direction) of the shaft member 30, and is the distance between the left end of one recess 31 and the right end of the other recess 31.

[0046] By providing two recesses 31 in this manner, and by positioning one of the two recesses 31 facing the spiral-shaped portions 21b1, 21c1, the length of the detection portion 21 of the flexible printed circuit board 20 can be shortened.

[0047] Although the configuration in which the shaft member 30 has two recesses 31 has been disclosed, the shaft member 30 has only one recess in another position sensor 101 in the embodiment shown in Figures 6 and 7. The position sensor 101 has the same configuration as the position sensor 100 except that the two recesses 31 of the position sensor 100 are combined into one recess 31. The detection portion 21 of the flexible printed circuit board 20 is configured to surround an area of ​​approximately 180 degrees of the shaft member 30. Therefore, it is preferable that the rotation angle of the shaft member 30 of the position sensor 101 be limited to 180 degrees or less.

[0048] Furthermore, shaft member 30 may have three or more recesses. In this case, the distance between each of the plurality of recesses is preferably set so that only one of the three or more recesses faces helical portion 21b1 and helical portion 21c1.

[0049] The operation of the position sensor 100 will now be described. When the shaft member 30 rotates, the two recesses 31 also rotate. One of the two recesses 31 always faces the spiral-shaped portions 21b1 and 21c1 of the detection portion 21. This causes a change in the magnetic field of the oscillator coil 21a received by the receiver coils 21b and 21c (spiral-shaped portions 21b1 and 21c1). In other words, the output voltage of the receiver coils 21b and 21c (spiral-shaped portions 21b1 and 21c1) corresponding to the position of the recess 31 is input to the control circuit 22a.

[0050] The control circuit 22a outputs a voltage that changes linearly with the amount of rotation (rotation angle) of the shaft member 30 based on the output voltage ratio between the receiving coil 21b (spiral-shaped portion 21b1) and the receiving coil 21c (spiral-shaped portion 21c1). More preferably, the control circuit 22a may be configured to detect the rotation speed from the rate of change of the output voltage (ratio). Also, more preferably, the control circuit 22a may be configured to output the rotation direction from the difference (increase / decrease) between the output voltages (ratio).

[0051] In this way, the position sensor 100 can detect the amount of rotation (rotation angle), rotation speed, rotation direction, etc. of the shaft member 30.

[0052] 8 and 9 show a further position sensor 200 according to an embodiment, which is a modification of the previously described position sensor 100. Portions having substantially the same configurations or functions as those of position sensor 100 are given the same reference numerals, and descriptions thereof will be omitted.

[0053] The guide member 10 further has a cylindrical portion 14. The cylindrical portion 14 is disposed below the cylindrical portion 11. The cylindrical portion 11, the base portion 12, and the cylindrical portion 14 are integrally formed. The cylindrical portion 14 protrudes downward from the base portion 12.

[0054] The cylindrical portion 14 has an inner wall portion 14a and an outer wall portion 14b. A gap is formed between the inner wall portion 14a and the outer wall portion 14b. A flexible printed circuit board 20 (a detection portion 24 described later) is disposed in the gap formed between the inner wall portion 14a and the outer wall portion 14b. The lower end of the inner wall portion 14a is connected to the lower end of the outer wall portion 14b.

[0055] The inner wall portion 14a is disposed closer to the shaft member 30 (a recess 32 described later) than the outer wall portion 14b. The inner wall portion 14a is formed in an annular shape so as to surround the entire circumference of the shaft member 30.

[0056] The outer wall portion 14b is provided so as to surround (cover) the inner wall portion 14a. The outer wall portion 14b has a slit 15 extending in the vertical direction. The inner wall portion 14a is exposed through the slit 15.

[0057] The guide member 10 can restrict the movement of the flexible printed circuit board 20 by disposing the flexible printed circuit board 20 between the inner wall portion 14a and the outer wall portion 14b. Furthermore, by providing the slits 15 in the outer wall portion 14b, the flexible printed circuit board 20 can be easily disposed between the inner wall portion 14a and the outer wall portion 14b.

[0058] The flexible printed circuit board 20 further has a detection portion 24 and a connection portion 26. The detection portion 24 is arranged so as to surround the cylindrical portion 14. The detection portion 24 is arranged on the cylindrical portion 14 in the same manner as the detection portion 21. The detection portions 21 and 24, the control portion 22, and the connection portions 23 and 26 are integrated. The detection portion 24 is connected to the control portion 22 via the connection portion 26 and is integrated with it.

[0059] The detection portion 24 is bent along the tubular portion 14 and is disposed so as to surround the tubular portion 14. Here, the detection portion 24 is disposed so as to surround approximately half of the tubular portion 14. In other words, the detection portion 24 is configured so as to surround an area of ​​approximately 180 degrees of the shaft member 30.

[0060] 10 is a schematic diagram of the detection portion 24. The detection portion 24 is disposed between the inner wall portion 14a and the outer wall portion 14b of the tubular portion 14. More specifically, the detection portion 24 has a central portion 24d, a left portion 24e, and a right portion 24f. The left portion 24e and the right portion 24f are disposed between the inner wall portion 14a and the outer wall portion 14b. The central portion 24d is disposed so as to be exposed from the slit 15. Here, the left portion 24e is located to the left of the central portion 24d, and the right portion 24f is located to the right of the central portion 24d. In other words, the left portion 24e and the right portion 24f are connected to the central portion 24d and are connected via the central portion 24d.

[0061] Here, the detection portion 24 has the same configuration as the detection portion 21 shown in Fig. 5 and is provided with an oscillator coil 24a and two receiver coils 24b and 24c. The oscillator coil 24a and two receiver coils 24b and 24c of the detection portion 24 have the same configuration as the oscillator coil 21a and two receiver coils 21b and 21c of the detection portion 21 shown in Fig. 5, respectively, but are rotated 90 degrees and overlapped. That is, the oscillator coil 24a and two receiver coils 24b and 24c of the detection portion 24 are enlarged or reduced from the oscillator coil 21a and two receiver coils 21b and 21c of the detection portion 21 shown in Fig. 5 and rotated 90 degrees and overlapped. The receiver coil 24b has a spiral-shaped portion 24b1 having a sine wave shape, and the receiver coil 24c has a spiral-shaped portion 24c1 having a sine wave shape. The relationship between the shapes of the spiral-shaped portion 24b1 and the spiral-shaped portion 24c1 is roughly that of a sine wave and a cosine wave. When viewed from above, the spiral-shaped portion 24b1 and the spiral-shaped portion 24c1 are not short-circuited within each other. In other words, the two receiver coils 24b and 24c are formed across multiple insulating layers via through-holes that penetrate the insulating layers. In the flexible printed circuit board 20, the detection portion 24 is connected to the detection portion 21 via the control portion 22, forming an integrated circuit.

[0062] The magnetic field generated by the transmitter coil 24a interlinks with the receiver coils 24b and 24c. Linear movement of the shaft member 30 in the vertical direction causes the recess 32 to move vertically relative to the receiver coils 24b and 24c, as shown in FIG. 10 . Because the recess 32 has locally low permeability or conductivity, the magnetic field interlinking the portions of the receiver coils 24b and 24c facing the recess 32 changes. By providing two receiver coils 24b and 24c with spiral-shaped portions 24b1 and 24c1 that exhibit a sine wave and cosine wave relationship, a voltage ratio can be obtained from the outputs of the two receiver coils. This voltage ratio changes as the interlinking magnetic field changes. The position sensor 200 can also detect the position of the recess 32 with high detection accuracy based on this voltage ratio.

[0063] The control portion 22 is provided with a control unit 25 including a control circuit 22a. The control unit 25 is electrically connected to the detection portions 21 and 24. More specifically, the control unit 25 has a control circuit 22a and a control circuit 22b, and the control circuit 22a is electrically connected to the detection portion 21, and the control circuit 22b is electrically connected to the detection portion 24.

[0064] The shaft member 30 is configured to be rotatable and also linearly movable. The shaft member 30 is disposed within the cylindrical portion 11 and the cylindrical portion 14. The shaft member 30 is made of a magnetic material and has a recess 32 formed on the side surface facing the detection portion 24 across the cylindrical portion 14. The recess 32 is formed along the circumferential direction of the shaft member 30. That is, the shape of the recess 32 is longer in the left-right direction and shorter in the up-down direction than the shape of the recess 31. That is, the vertical width of the recess 31 is longer than the vertical width of the recess 32, and the leftward (left-right) width of the recess 31 is shorter than the leftward (left-right) width of the recess 32.

[0065] When the shaft member 30 rotates, the oscillator coil 21a and the two receiver coils 21b and 21c provided in the detection portion 21 detect changes in the magnetic field caused by the movement of the recess 31. When the shaft member 30 moves linearly along the central axis C11 of the cylindrical portion 11, the oscillator coil and the two receiver coils provided in the detection portion 24 detect changes in the magnetic field caused by the movement of the recess 32.

[0066] The control circuit 22a receives inputs from the two receiving coils 21b, 21c of the detection portion 21 and outputs electrical signals corresponding to the amount of rotation (rotation angle), rotation speed, rotation direction, etc. of the shaft member 30. In addition, the control circuit 22b receives inputs from the two receiving coils 24b, 24c and outputs electrical signals corresponding to the amount of movement, movement speed, movement direction, etc. of the shaft member 30 along the central axis C11.

[0067] With this configuration, the position sensor 200 can detect both the rotation and linear movement of the shaft member 30 using a single flexible printed circuit board 20 .

[0068] The position sensor 200 does not have the cylindrical portion 11 and the detection portion 21, and the shaft member 30 does not have to have the recess 31. A position sensor having this configuration cannot detect the rotation of the shaft member 30, but can detect linear movement in the vertical direction.

[0069] It should be noted that the shaft member 30 itself does not need to be magnetic, at least in the portion facing the detection portion 24. For example, the shaft member 30 may be made of an insulating non-magnetic material, and in this embodiment, may be a resin member made of resin. In this case, a separate magnetic member may be provided inside the recess 32. This configuration will be described later.

[0070] Furthermore, if the shaft member 30 is conductive instead of magnetic, the shaft member 30 itself does not need to be conductive, at least in the portion facing the detection portion 24. For example, the shaft member 30 may be a resin member made of resin. In this case, a separate conductive member may be provided inside the recess 32. This configuration will be described later.

[0071] Furthermore, the control unit does not need to have two control circuits 22 a and 22 b. The control circuit 22 a may be configured to receive inputs from the oscillation coils and two receiving coils of both the detection portion 21 and the detection portion 24, and to provide outputs according to the respective inputs.

[0072] Fig. 11A is a perspective view of yet another shaft member 130 of a position sensor according to the present disclosure. The position sensor 100 shown in Fig. 1 may include a shaft member 130 instead of the shaft member 30 shown in Fig. 2. The shaft member 130 has the same overall shape as the shaft member 30.

[0073] FIG. 11B is a rear view of shaft member 130. FIG. 11C is a cross-sectional view of shaft member 130 taken along line XIC-XIC in FIG. 11B. FIG. 11D is an exploded perspective view of shaft member 130. Shaft member 130 includes shaft main body 130A having recess 131 formed on the side surface facing detection portion 21 across tubular portion 11, and magnetic separate member 130B disposed within recess 131 so as to be positioned inward from the side surface of shaft main body 130A. Shaft main body 130A is made of an insulating, non-magnetic material such as resin. Separate member 130B is made of a magnetic material such as iron oxide, chromium oxide, cobalt, ferrite, or oxide. Shaft member 130 operates in the same manner as shaft member 30 shown in FIGS. 1 and 2 and can detect its angular position.

[0074] Separate member 130B may be conductive instead of magnetic. In this case, shaft body 130A is made of an insulating material such as resin, and separate member 130B is made of a conductive material such as a metal such as iron, aluminum, copper, or SUS. Separate member 130B and shaft body 130A may be magnetic or non-magnetic.

[0075] Rotation of the shaft member 30 causes the recess 31 to move left and right and front and rear relative to the receiving coils 21b and 21c as shown in Figure 5. Because the recess 31 has locally high magnetic permeability or conductivity, the magnetic field interlinking the portions of the receiving coils 21b and 21c facing the recess 31 changes. This makes it possible to detect the position of the recess 31, i.e., the angular position of the recess 31.

[0076] Fig. 12A is a perspective view of yet another shaft member 230 of a position sensor according to the present disclosure. The position sensor 100 shown in Fig. 1 may include the shaft member 230 instead of the shaft member 30 shown in Fig. 2. The shaft member 230 has the same overall shape as the shaft member 30.

[0077] FIG. 12B is a rear view of shaft member 230. FIG. 12C is a cross-sectional view of shaft member 230 taken along line XIIC-XIIC in FIG. 12B. Shaft member 230 comprises shaft main body 230A, which has a side surface facing detection portion 21 across tubular portion 11, and separate magnetic member 230B embedded in shaft main body 230A so as not to be exposed from the side surface of shaft main body 230A. FIG. 12D is a perspective view of separate member 230B. Shaft main body 230A is made of an insulating, non-magnetic material such as resin. Separate member 230B is made of a magnetic material such as iron oxide, chromium oxide, cobalt, ferrite, or oxide. Shaft member 230 operates in the same manner as shaft member 30 shown in FIGS. 1 and 2 and can detect its angular position.

[0078] Separate member 230B may be conductive instead of magnetic. In this case, shaft body 230A is made of an insulating material such as resin, and separate member 230B is made of a conductive material such as a metal such as iron, aluminum, copper, or SUS. Separate member 230B and shaft body 230A may be magnetic or non-magnetic.

[0079] Fig. 13A is a perspective view of yet another shaft member 330 of a position sensor according to the present disclosure. The position sensor 100 shown in Fig. 1 may include a shaft member 330 instead of the shaft member 30 shown in Fig. 2. The shaft member 330 has the same overall shape as the shaft member 30.

[0080] FIG. 13B is a rear view of shaft member 330. FIG. 13C is a cross-sectional view of shaft member 330 taken along line XIIIC-XIIIC in FIG. 13B. Shaft member 330 has shaft main body 330A with recess 331 formed on the side surface facing detection portion 21 across tubular portion 11, and magnetic separate member 330B disposed within recess 331 so as to be positioned more inward than the side surface of shaft main body 330A. FIG. 13D is a perspective view of separate member 330B. Shaft main body 330A is made of an insulating non-magnetic material such as resin. Separate member 330B is made of a magnetic material such as iron oxide, chromium oxide, cobalt, ferrite, or oxide.

[0081] Separate member 330B has base portion 1330B extending along central axis C11 and protruding portion 2330B protruding from base portion 1330B. Base portion 1330B is not exposed from the side surface of shaft body 330A, but protruding portion 2330B is exposed from the side surface. Shaft member 330 operates in the same manner as shaft member 30 shown in Figures 1 and 2, and its angular position can be detected.

[0082] Separate member 330B may be conductive instead of magnetic. In this case, shaft body 330A is made of an insulating material such as resin, and separate member 330B is made of a conductive material such as a metal such as iron, aluminum, copper, or SUS. Separate member 330B and shaft body 330A may be magnetic or non-magnetic.

[0083] Fig. 14 is a perspective view of yet another shaft member 430 of the position sensor according to the present disclosure. The position sensor 200 shown in Fig. 8 may include a shaft member 430 instead of the shaft member 30 shown in Fig. 9. The shaft member 430 has the same overall shape as the shaft member 30.

[0084] Shaft member 430 includes shaft main body 530A having recess 531 formed on its side surface facing detection portion 21 across cylindrical portion 11 and recess 532 formed on its side surface facing detection portion 24 across cylindrical portion 11; magnetic separate member 530B disposed within recess 531 so as to be positioned inward from the side surface of shaft main body 530A; and magnetic separate member 530C disposed within recess 532 so as to be positioned inward from the side surface of shaft main body 530A. Shaft main body 530A is made of an insulating non-magnetic material such as resin. Separate members 530B and 530C are made of a magnetic material such as iron oxide, chromium oxide, cobalt, ferrite, or oxide. Shaft member 430 operates similarly to shaft member 30 shown in FIGS. 8 and 9 and can detect its angular position and linear movement.

[0085] Separate members 530B and 530C may be conductive instead of magnetic. In this case, shaft body 530A is made of an insulating material such as resin, and separate members 530B and 530C are made of a conductive material such as a metal such as iron, aluminum, copper, or SUS. Separate members 530B and 530C and shaft body 530A may be magnetic or non-magnetic.

[0086] Figure 15A is a perspective view of yet another position sensor 500 according to the present disclosure. Figure 15B is a rear view of the position sensor 500. Figure 15C is a cross-sectional view of the position sensor 500 shown in Figure 15B taken along line XVC-XVC. In Figures 15A to 15C, the same reference numerals are used to denote the same parts as those in the position sensor 100 shown in Figures 1 to 5.

[0087] The position sensor 500 includes a shaft member 630 instead of the shaft member 30 of the position sensor 100 shown in Figures 1 to 5. The shaft member 30 of the position sensor 100 shown in Figure 1 is surrounded by the cylindrical portion 11 and rotates or moves linearly within the cylindrical portion 11. The shaft member 630 of the position sensor 500 is made of the same material as the shaft member 30 and is disposed outside the cylindrical portion 11 and is not surrounded by the cylindrical portion 11. However, like the shaft member 30, it rotates around the central axis C11 along the cylindrical portion 11 or moves linearly up and down.

[0088] The shaft member 630 has a magnetic surface on the side facing the detection portion 21 across the cylindrical portion 11, and is formed with a recess 631. The shaft member 630 operates in the same manner as the shaft member 30 shown in Figures 1 and 2, and can detect its angular position.

[0089] The shaft member 630 may be conductive instead of magnetic. In this case, the shaft member 630 may be either magnetic or non-magnetic. The shaft member 630 does not need to be made of only a conductor. For example, the shaft member 630 may be made of a mixture of a conductor and an insulator or a joint of a conductor and an insulator, and may be conductive at least in the portion facing the detection portion 21.

[0090] Figure 16 is a cross-sectional view of yet another position sensor 600 according to the present disclosure. In Figure 16, the same parts as those in position sensor 500 shown in Figures 15A to 15C are designated by the same reference numerals.

[0091] 1 to 5 , the position sensor 600 includes a shaft member 630 instead of the shaft member 30 of the position sensor 100 shown in FIG. 1 is surrounded by the cylindrical portion 11 and rotates or moves linearly within the cylindrical portion 11. The shaft member 630 of the position sensor 600 is made of the same material as the shaft member 30 and is disposed outside the cylindrical portion 11 and is not surrounded by the cylindrical portion 11. However, like the shaft member 30, the shaft member 630 rotates around the central axis C11 along the cylindrical portion 11 or moves linearly up and down.

[0092] Shaft member 630 has shaft main body 630A with recess 631 formed on the side facing detection portion 21 across cylindrical portion 11, and magnetic separate member 630B arranged in recess 631 so as to be located inward from the side surface of shaft main body 630A. Shaft main body 630A is made of an insulating non-magnetic material such as resin. Separate member 630B is made of a magnetic material such as iron oxide, chromium oxide, cobalt, ferrite, or oxide. Shaft member 630 operates in the same manner as shaft member 30 shown in FIGS. 1 and 2 and can detect its angular position.

[0093] Separate member 630B may be conductive instead of magnetic. In this case, shaft body 630A is made of an insulating material such as resin, and separate member 630B is made of a conductive material such as a metal such as iron, aluminum, copper, or SUS. Separate member 630B and shaft body 630A may be magnetic or non-magnetic.

[0094] DESCRIPTION OF SYMBOLS 10 Guide member 11 Cylindrical portion (first cylindrical portion) 11a Inner wall portion 11b Outer wall portion 12 Base portion 13 Slit 14 Cylindrical portion (second cylindrical portion) 20 Flexible printed circuit board 21 Detection portion (first detection portion) 21d Center portion 21e Left portion 21f Right portion 21a Oscillating coil (first oscillator coil) 21b Receiving coil (first receiving coil) 21c Receiving coil (second receiving coil) 21b1 Spiral-shaped portion (first spiral-shaped portion) 21c1 Spiral-shaped portion (second spiral-shaped portion) 22 Control portion 22a Control circuit (first control circuit) 22b Control circuit (second control circuit) 23 Connection portion 23a Leading wiring 24 Second detection portion 25 Control unit 30 Shaft member 31 Recess (first recess) 32 Recess (second recess) 100 Position sensor 101 Position sensor 200 Position sensor

Claims

1. A guide member including a first cylindrical portion having a cylindrical shape surrounding a central axis extending in a vertical direction and extending along the central axis; a flexible printed circuit board having a first detection portion arranged to surround the first cylindrical portion; a shaft member that rotates around the central axis or moves linearly in the vertical direction along the first cylindrical portion; Equipped with The first detection moiety is A first oscillator coil; a first receiving coil for receiving a magnetic field generated by the first oscillator coil; Including, The shaft member is a side surface of the first cylindrical portion facing the first detection portion has magnetism and has a first recess formed thereon; or a non-magnetic shaft body having a first recess formed on a side surface facing the first detection portion across the first cylindrical portion; a first separate member having magnetic properties and disposed in the first recess so as to be located inside a side surface of the shaft body; having With configuration, Position sensor.

2. The shaft member is surrounded by the first cylindrical portion and rotates or moves linearly within the first cylindrical portion. The position sensor of claim 1 .

3. the first detection portion further includes a second receiving coil insulated from the first receiving coil; the first receive coil having a first helical portion; the second receive coil has a second helical portion; The relationship between the first spiral-shaped portion and the second spiral-shaped portion is a relationship between a sine wave and a cosine wave. The position sensor of claim 1 .

4. The flexible printed circuit board is a control portion that receives an input from the first detection portion; a connection portion that connects the control portion and the first detection portion and has a width narrower than the control portion and the first detection portion; having the control portion includes a first control circuit; The connection portion includes wiring that connects the first control circuit, the first oscillator coil, and the first receiver coil. A position sensor according to any one of claims 1 to 3.

5. The first cylindrical portion includes: An inner wall portion surrounding the shaft member; An outer wall portion surrounding the inner wall portion; Including, The first detection portion is disposed between the inner wall portion and the outer wall portion.

5. The position sensor of claim 4.

6. The outer wall portion is provided with a slit, The first detection moiety is A central portion exposed from the slit; a left portion located in a left direction perpendicular to the up-down direction from the central portion, connected to the central portion, and disposed between the outer wall portion and the inner wall portion; a right portion located rightward from the central portion, connected to the central portion, and disposed between the outer wall portion and the inner wall portion; having 6. The position sensor of claim 5.

7. The guide member further includes a second cylindrical portion located below the first cylindrical portion, the flexible printed circuit board further includes a second detection portion disposed so as to surround the second cylinder portion and including a second oscillator coil and a third receiver coil that receives a magnetic field generated by the second oscillator coil; the control portion has a control unit electrically connected to the first detection portion and the second detection portion and including the first control circuit; The shaft member is a side surface facing the second detection portion across the second cylindrical portion has magnetism and has a second recess formed thereon; or a second recess is formed on a side surface of the shaft body facing the second detection portion across the second cylindrical portion, The shaft body further includes a second separate member having magnetic properties and disposed in the second recess so as to be located inside the side surface of the shaft body. With the configuration, The width of the first recess in the vertical direction is longer than the width of the second recess in the vertical direction, a width of the first recess in a left direction is longer than a width of the first recess in the left direction; The shaft member rotates and moves in the up and down direction.

7. The position sensor of claim 6.

8. the control unit further includes a second control circuit that receives an input from the second detection portion.

8. The position sensor of claim 7.

9. A guide member including a first cylindrical portion having a cylindrical shape surrounding a central axis extending in a vertical direction and extending along the central axis; a flexible printed circuit board having a first detection portion arranged to surround the first cylindrical portion; a shaft member that rotates around the central axis or moves linearly in the vertical direction along the first cylindrical portion; Equipped with The first detection moiety is A first oscillator coil; a first receiving coil for receiving a magnetic field generated by the first oscillator coil; Including, The shaft member is a first recess is formed on a side surface of the first cylindrical portion that faces the first detection portion and is conductive; or a shaft body having insulating properties and a first recess formed on a side surface facing the first detection portion across the first cylindrical portion; a first separate member having electrical conductivity and disposed in the first recess so as to be located inwardly of a side surface of the shaft body; having With configuration, Position sensor.

10. The shaft member is surrounded by the first cylindrical portion and rotates or moves linearly within the first cylindrical portion.

10. The position sensor of claim 9.

11. the first detection portion further includes a second receiving coil insulated from the first receiving coil; the first receive coil having a first helical portion; the second receive coil has a second helical portion; The relationship between the first spiral-shaped portion and the second spiral-shaped portion is a relationship between a sine wave and a cosine wave.

10. The position sensor of claim 9.

12. The flexible printed circuit board is a control portion that receives an input from the first detection portion; a connection portion that connects the control portion and the first detection portion and has a width narrower than the control portion and the first detection portion; having the control portion includes a first control circuit; The connection portion includes wiring that connects the first control circuit, the first oscillator coil, and the first receiver coil. A position sensor according to any one of claims 9 to 11.

13. The first cylindrical portion includes: An inner wall portion surrounding the shaft member; An outer wall portion surrounding the inner wall portion; Including, The first detection portion is disposed between the inner wall portion and the outer wall portion.

13. The position sensor of claim 12.

14. The outer wall portion is provided with a slit, The first detection moiety is A central portion exposed from the slit; a left portion located in a left direction perpendicular to the up-down direction from the central portion, connected to the central portion, and disposed between the outer wall portion and the inner wall portion; a right portion located rightward from the central portion, connected to the central portion, and disposed between the outer wall portion and the inner wall portion; having 14. The position sensor of claim 13.

15. The guide member further includes a second cylindrical portion located below the first cylindrical portion, the flexible printed circuit board further includes a second detection portion disposed so as to surround the second cylinder portion and including a second oscillator coil and a third receiver coil that receives a magnetic field generated by the second oscillator coil; the control portion has a control unit electrically connected to the first detection portion and the second detection portion and including the first control circuit; The shaft member is a side surface facing the second detection portion across the second cylindrical portion has magnetism and has a second recess formed thereon; or a second recess is formed on a side surface of the shaft body facing the second detection portion across the second cylindrical portion, a second separate member having electrical conductivity and disposed in the second recess so as to be located inwardly of a side surface of the shaft body; With the configuration, The width of the first recess in the vertical direction is longer than the width of the second recess in the vertical direction, a width in a left direction of the second recess is greater than a width in the left direction of the first recess; The shaft member rotates and moves in the up and down direction.

15. The position sensor of claim 14.

16. the control unit further includes a second control circuit that receives an input from the second detection portion.

16. The position sensor of claim 15.

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