Position detection device, detection device, and board support

Abstract

To provide a board support for preventing strain from being generated in a board that is a support object, and to provide a position detection device and a detection device having the board support.SOLUTION: A stroke sensor 2 as a position detection device comprises a board 5 in which a wire for detecting the position of a rack shaft 12 is formed, and a board support 21 for supporting the board 5 relative to a rack housing 11, and detects the position of the rack shaft 12 relative to the rack housing 11. The board 5 is disposed in a mounting hole 112 formed in the rack housing 11, and extends along the traveling direction of the rack shaft 12 relative to the rack housing 11. In the board support 21, a core 41 made of a material harder than the resin of a resin member 3 is embedded to the resin member 3 made of resin having multiple support sections 34 for supporting the board 5 in multiple places. The core 41 extends in parallel with the board 5 along the traveling direction of the rack shaft 12.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a position detection device that detects the position of a moving member, a detection device that detects a physical quantity that changes depending on the state of a detection object inside a housing, and a substrate support that supports a long substrate. [Background technology]

[0002] Conventionally, a long substrate may be supported by a resin substrate support. In a position detection device described in Patent Document 1, a substrate on which an excitation coil and a detection coil for detecting the position of a target fixed to a rack shaft are formed by a wiring pattern is fixed to the back surface of a lid of a housing having a metal main body and a resin lid. In an LED light source scanner module described in Patent Document 2, a plurality of LED chips are arranged in a row on one surface of a strip-shaped substrate, and the other surface of the substrate is fixed to a resin substrate holder. In the position detection device described in Patent Document 1, the housing lid corresponds to the substrate support, and in the LED light source scanner module described in Patent Document 2, the substrate holder corresponds to the substrate support. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-174533 [Patent Document 2] JP 2019-50161 A Summary of the Invention [Problem to be solved by the invention]

[0004] When molding a resin substrate support, molten resin is injected into a mold by injection molding. When the injected resin cools and solidifies, the resin may shrink, causing warping of the molded substrate support. This warping of the substrate support may cause distortion of the substrate. Therefore, an object of the present invention is to provide a substrate support that is less likely to cause distortion in the substrate it supports, and a position detection device and detection device that include such a substrate support. [Means for solving the problem]

[0005] The present invention aims to solve the above-mentioned problems and provides a position detection device that detects the position of a movable member moving within a housing, comprising a substrate on which wiring for detecting the position of the movable member is formed, and a substrate support that supports the substrate relative to the housing, wherein the substrate is placed in a mounting hole formed in the housing and extends along the movement direction of the movable member relative to the housing, and the substrate support is a resin member made of resin having multiple support parts that support the substrate at multiple points, in which a core material made of a material harder than the resin is embedded, and the core material extends parallel to the substrate along the movement direction of the movable member.

[0006] In addition, for the purpose of solving the above-mentioned problems, the present invention provides a detection device that detects a physical quantity that changes depending on the state of a detection object within a housing, comprising a substrate and a substrate support that supports the substrate relative to the housing, the substrate being placed in a mounting hole formed in the housing, the substrate support being a resin member made of resin having multiple support portions that support the substrate at multiple points, with a core material made of a material harder than the resin embedded in the resin member, and the core material extending parallel to the substrate.

[0007] In addition, in order to solve the above-mentioned problems, the present invention provides a substrate support for supporting a long substrate, comprising: a resin member made of resin having a plurality of support portions that support the substrate at a plurality of points in the longitudinal direction of the substrate; and a core material made of a material harder than the resin, wherein the core material extends in the longitudinal direction of the substrate and is embedded in the resin member. [Effects of the Invention]

[0008] According to the present invention, it is possible to suppress warping of a substrate supported by a substrate support. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a steer-by-wire steering device including a stroke sensor as a position detection device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view showing a cross section of the steering device taken along line AA in FIG. [Figure 3] FIG. 2 is an external view showing a stroke sensor attached to a rack housing together with a rack shaft. [Figure 4] FIG. 2 is an exploded perspective view of the stroke sensor. [Figure 5] FIG. 2 is an exploded perspective view of the stroke sensor. [Figure 6] 4(a) and 4(b) are cross-sectional views of the stroke sensor taken along lines BB and CC in FIG. 3. FIG. [Figure 7] FIG. 4 is a cross-sectional view of the stroke sensor taken along line DD in FIG. 3. [Figure 8] 1A is a plan view showing an example of a wiring pattern of a first wiring layer and a third wiring layer of a substrate, and FIG. 1B is a plan view showing an example of a wiring pattern of a second wiring layer and a fourth wiring layer of a substrate. [Figure 9] FIG. 2 is a plan view showing the wiring patterns of a first wiring layer, a second wiring layer, a third wiring layer, and a fourth wiring layer of the substrate superimposed on each other. [Figure 10]1(a) is a plan view showing one surface of the substrate support, and FIG. 1(b) is a plan view showing the other surface of the substrate support. [Figure 11] 1A is a cross-sectional view of a jig used in a molding process of a resin member, and FIG. 1B is a perspective view showing the appearance of a part of the jig. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 1 is a schematic diagram of a vehicle equipped with a steer-by-wire steering device 1 equipped with a stroke sensor 2 according to an embodiment of the present invention.

[0011] 1, the steering device 1 includes a stroke sensor 2 as a position detection device, a cylindrical rack housing 11 fixed to the vehicle body, a rack shaft 12 as a moving member that moves within the rack housing 11, ball joints 13 provided at both ends of the rack shaft 12, tie rods 14 connected to the rack shaft 12 via the ball joints 13, a worm reduction mechanism 15 having a pinion gear 151 meshed with rack teeth 121 of the rack shaft 12, an electric motor 16 that applies axial moving force to the rack shaft 12 via the worm reduction mechanism 15, a steering wheel 17 operated by a driver, a steering angle sensor 18 that detects the steering angle of the steering wheel 17, and a steering control device 19 that controls the electric motor 16 based on the steering angle detected by the steering angle sensor 18. The rack shaft 12 steers the left and right steerable front wheels 1L and 1R by moving in the axial direction.

[0012] The rack shaft 12 is supported by a pair of rack bushings 100 attached to the rack housing 11 and is housed in the rack housing 11, with both ends protruding from the rack housing 11. The stroke sensor 2 detects the position of the rack shaft 12 relative to the rack housing 11. In FIG. 1 , the rack housing 11 is indicated by a two-dot chain line, and the rack shaft 12 and worm reduction mechanism 15 inside it are indicated by solid lines. The worm reduction mechanism 15 has a worm wheel 152 and a worm gear 153, and a pinion gear 151 is fixed to the worm wheel 152. The worm gear 153 is fixed to a motor shaft 161 of the electric motor 16.

[0013] The electric motor 16 generates torque by current supplied from the steering control device 19, and rotation of the motor shaft 161 rotates the worm wheel 152 and pinion gear 151 via the worm gear 153. When the pinion gear 151 rotates, the rack shaft 12 moves forward and backward in the axial direction within a predetermined range along the vehicle width direction, thereby steering the left and right front wheels 1L, 1R. The rack shaft 12 can move to the right and left in the vehicle width direction from a neutral position where the steering angle is zero. In FIG. 1, the range R1 within which the rack shaft 12 can move in the vehicle width direction is indicated by a double-headed arrow.

[0014] Fig. 2 is a cross-sectional view showing the steering device 1 taken along line AA in Fig. 1. Fig. 3 is an external view showing the stroke sensor 2 attached to the rack housing 11 together with the rack shaft 12. Figs. 4 and 5 are exploded perspective views of the stroke sensor 2. Figs. 6(a) and 6(b) are cross-sectional views of the stroke sensor 2 taken along lines BB and CC in Fig. 3. Fig. 7 is a cross-sectional view of the stroke sensor 2 taken along line DD in Fig. 3.

[0015] The stroke sensor 2 includes a detection body 20 fixed to the rack shaft 12, a board support 21 in which a core material 41 and a plurality of collars 42 are embedded in a resin member 3 made of resin by insert molding, a board 5 supported by the board support 21, electronic components 61 and connectors 62 mounted on the board 5, a seal member 71 attached to the board support 21, and a sealing member 72 that seals the board 5 and prevents the seal member 71 from coming off. The stroke sensor 2 detects the position of the rack shaft 12 relative to the rack housing 11 based on the position of the detection body 20. The board support 21 supports the board 5 relative to the rack housing 11. 2 and 3 show the central axis C of the rack shaft 12. The rack shaft 12 moves in the axial direction along the central axis C. Wiring for detecting the position of the rack shaft 12 is formed on the board 5.

[0016] The rack housing 11 is made of metal, for example, a die-cast aluminum alloy. The rack housing 11 is formed with an accommodation hole 111 that accommodates the rack shaft 12 and a mounting hole 112 for attaching the stroke sensor 2. The mounting hole 112 is a through-hole that penetrates the rack housing 11 in a direction perpendicular to the central axis C of the rack shaft 12 and opens into a mounting surface 11a to which the rack housing 11 is attached. The rack housing 11 also has a plurality of screw holes 113 that open into the mounting surface 11a formed around the mounting hole 112. The mounting surface 11a is part of the outer surface of the rack housing 11 and is a flat surface that is parallel to the central axis C of the rack shaft 12.

[0017] The rack shaft 12 is a shaft-shaped member made of steel such as carbon steel. The detection body 20 is attached to the outer peripheral surface 12a of the rack shaft 12 by, for example, welding. The detection body 20 is made of a material having a higher magnetic permeability than the rack shaft 12 or a material having a higher electrical conductivity than the rack shaft 12. When using a material having a higher magnetic permeability than the rack shaft 12 as the material for the detection body 20, it is desirable to use a magnetic material such as ferrite, which has a high electrical resistance and is less likely to generate eddy currents. When using a material having a higher electrical conductivity than the rack shaft 12 for the detection body 20, it is possible to use a metal containing aluminum or copper as the main component, for example. The detection body 20 may be formed integrally with the rack shaft 12 as a part of the rack shaft 12.

[0018] The detection body 20 is attached in a position aligned with the circuit board 5 in a direction perpendicular to the central axis C of the rack shaft 12, with the sealing member 72 sandwiched between them, over the entire range R1 within which the rack shaft 12 can move in the vehicle width direction. However, for the sake of explanation, in FIG. 3 , the detection body 20 is shifted from the position aligned with the circuit board 5. The surface 20a of the detection body 20 facing the sealing member 72 is flat. In this embodiment, the magnetic action of the detection body 20 is utilized to detect the position of the detection body 20 by the wiring pattern of the circuit board 5 and the electronic components 61.

[0019] The substrate 5 has a long rectangular shape with the longitudinal direction being parallel to the central axis C of the rack shaft 12. In other words, the substrate 5 extends along the movement direction of the rack shaft 12 relative to the rack housing 11. The entire substrate 5 is disposed within the mounting hole 112 of the rack housing 11. Next, the configuration of the substrate 5 will be described.

[0020] As shown in FIG. 2, the substrate 5 is a four-layer substrate having, from the front surface 5a facing the detection body 20 toward the back surface 5b, a first wiring layer 501, a second wiring layer 502, a third wiring layer 503, and a fourth wiring layer 504. Between the first wiring layer 501 and the second wiring layer 502, between the second wiring layer 502 and the third wiring layer 503, and between the third wiring layer 503 and the fourth wiring layer 504, base materials 50 made of a dielectric such as FR4 (glass fiber impregnated with epoxy resin and subjected to a thermosetting treatment) are disposed. The first wiring layer 501 and the fourth wiring layer 504, which are outer layers, are covered with an electrically insulating resist film 500. Wiring patterns are formed on the first wiring layer 501, the second wiring layer 502, the third wiring layer 503, and the fourth wiring layer 504, respectively, and the wiring patterns of these layers are connected by vias 54 at multiple locations on the substrate 5.

[0021] FIG. 8(a) is a plan view showing an example of the wiring patterns of the first wiring layer 501 and the third wiring layer 503 of the substrate 5. FIG. 8(b) is a plan view showing an example of the wiring patterns of the second wiring layer 502 and the fourth wiring layer 504 of the substrate 5. FIG. 9 is a plan view showing the wiring patterns of the first wiring layer 501, the second wiring layer 502, the third wiring layer 503, and the fourth wiring layer 504 of the substrate 5 superimposed on each other. In FIGS. 8(a), 8(b), and 9, the wiring patterns of the third wiring layer 503 and the fourth wiring layer 504 are shown in gray. In FIGS. 8(a), 8(b), and 9, a portion of the wiring pattern in the longitudinal direction of the substrate 5 is shown. In addition, in FIGS. 8(a), 8(b), and 9, the dimension in the width direction (vertical direction) of the substrate 5 is enlarged relative to the dimension in the longitudinal direction (horizontal direction) of the substrate 5 to clarify the contents of the drawings.

[0022] An excitation coil 51 that generates a magnetic field, and a first detection coil 52 and a second detection coil 53 that detect the magnetic field generated by the excitation coil 51 are formed by a wiring pattern on the substrate 5. The excitation coil 51 is formed on a first wiring layer 501 and a third wiring layer 503 along the periphery of the substrate 5. The first detection coil 52 is formed on the first wiring layer 501 and the third wiring layer 503. The second detection coil 53 is formed on a second wiring layer 502 and a fourth wiring layer 504.

[0023] The first detection coil 52 is made up of a pair of curved portions 521, 522 that form a sine wave when viewed from the front surface 5a of the substrate 5. The second detection coil 53 is made up of a pair of curved portions 531, 532 that form a cosine wave when viewed from the front surface 5a of the substrate 5. The excitation coil 51, the first detection coil 52, and the second detection coil 53 are each formed in a loop shape, and their starting and ending ends are connected to terminals of an electronic component 61. The electronic component 61 is, for example, an ASIC (application-specific integrated circuit), and is arranged at one end in the longitudinal direction of the substrate 5 together with a connector 62. The connector 62 is connected to the steering control device 19 by a cable 10 (see FIG. 1). The pair of curved portions 521, 522 of the first detection coil 52 and the pair of curved portions 531, 532 of the second detection coil 53 are connected by vias 54 at the other end in the longitudinal direction of the substrate 5.

[0024] The excitation coil 51 generates an AC magnetic field in a direction perpendicular to the substrate 5 by a high-frequency current supplied from the electronic component 61, and the spatial magnetic flux generated by the current flowing through the excitation coil 51 interlinks with the first detection coil 52 and the second detection coil 53. The spatial magnetic flux generated by the excitation coil 51 also interlinks with the detection body 20. The magnetic flux interlinking with the detection body 20 affects the magnetic flux intensity distribution on the substrate 5. The intensity of the magnetic field received by the first detection coil 52 and the second detection coil 53 is a physical quantity that changes depending on the state (position relative to the rack housing 11) of the rack shaft 12, which is the detection target of the stroke sensor 2.

[0025] If the detection body 20 is made of a material with high magnetic permeability, magnetic flux flows concentrated in the detection body 20, increasing the magnetic flux density at the position on the board 5 corresponding to the detection body 20. If the detection body 20 is made of a material with high conductivity, eddy currents generated in the detection body 20 reduce the magnetic flux density at the position on the board 5 corresponding to the detection body 20. The spacing between the pair of curved portions 521, 522 of the first detection coil 52 in the width direction of the board 5 and the spacing between the pair of curved portions 531, 532 of the second detection coil 53 vary depending on the position in the longitudinal direction of the board 5, and therefore the induced voltages generated in the first detection coil 52 and the second detection coil 53 vary depending on the positions of the rack shaft 12 and the detection body 20.

[0026] The first and second detection coils 52 and 53 output output signals, which are voltages induced by the AC magnetic field generated by the excitation coil 51, to the electronic component 61. The electronic component 61 calculates the position of the detection body 20 based on the output signals and transmits the calculation result to the steering control device 19. The magnitudes of the voltages induced in the first and second detection coils 52 and 53 change within a range of less than one cycle while the rack shaft 12 moves from one axial end to the other axial end. Furthermore, due to the difference in shape between the first and second detection coils 52 and 53, the phases of the changes in the magnitudes of the voltages induced in the first and second detection coils 52 and 53 as the rack shaft 12 moves are different by 90°. Therefore, the stroke sensor 2 can detect the absolute position of the rack shaft 12 throughout the entire range R1 in which the rack shaft 12 can move axially.

[0027] Furthermore, a plurality of fixing holes 55 for fixing to the substrate support 21 are formed in the substrate 5, penetrating between the front surface 5a and the back surface 5b. Each fixing hole 55 is formed in the center of the width direction of the substrate 5 at a position that does not overlap with the wiring patterns of the excitation coil 51, the first detection coil 52, and the second detection coil 53. Next, the configuration of the substrate support 21 will be described in detail.

[0028] The board support body 21 is a resin molded body in which a core material 41 and a plurality of metal collars 42 are embedded in a resin member 3 by insert molding. The resin material of the resin member 3 is not particularly limited, but suitable examples include PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), and 66 nylon. The core material 41 is made of a material harder than the resin constituting the resin member 3, and extends parallel to the board 5 along the movement direction of the rack shaft 12. The core material 41 is a flat plate parallel to the board 5, and is disposed on the side of the board 5 opposite to the rack shaft 12 side (outside the mounting hole 112). The core material 41 increases the strength of the board support body 21 and suppresses deformation of the board support body 21.

[0029] 3 and 4, the core material 41 has a rectangular shape and extends in the longitudinal direction of the substrate 5. The core material 41 has a plurality of flow holes 411 formed therein to allow the resin to flow when the resin member 3 is molded, and also has a plurality of cutouts 412 formed around its periphery. The core material 41 is made of iron or a metal having higher conductivity than iron, and has a shielding effect against the excitation coil 51, first detection coil 52, and second detection coil 53 formed on the substrate 5.

[0030] In this embodiment, the core material 41 is an aluminum plate whose main component is aluminum, a metal with higher conductivity than iron. However, the material of the core material 41 is not limited to this, and it may be, for example, copper or a copper alloy. The shielding effect of the core material 41 reduces the effect of external electromagnetic waves generated by, for example, the electric motor 16 on the voltages induced in the first detection coil 52 and the second detection coil 53, and also prevents the magnetic field generated by the excitation coil 51 from leaking to the outside.

[0031] Fig. 10(a) is a plan view showing one surface side (substrate 5 side) of the substrate support body 21. Fig. 10(b) is a plan view showing the other surface side (opposite side to the substrate 5) of the substrate support body 21. In Fig. 10(a), the outline of the core material 41 embedded in the resin member 3 is shown by a dashed line. The core material 41 is covered by the resin member 3 except for the portion that is held in a mold in the molding process of the resin member 3, which will be described later.

[0032] The resin member 3 integrally includes a long plate portion 31 in which a core material 41 is embedded, a peripheral wall portion 32 provided to surround the periphery of the long plate portion 31, a connecting portion 33 connecting the long plate portion 31 and the peripheral wall portion 32, a plurality of support portions 34 that support the substrate 5 at a plurality of locations, a rib portion 35 for increasing rigidity, a plurality of fixing portions 36 that are fixed to the rack housing 11, and a connector accommodating portion 37 that accommodates the connector 62. In the molding process of the resin member 3, molten resin is injected from a plurality of injection portions 30 shown in FIG. 10(b). In this embodiment, as an example, molten resin is injected simultaneously from five injection portions 30.

[0033] The long plate portion 31 has a rectangular shape with its longitudinal direction coinciding with the movement direction of the rack shaft 12. Both longitudinal ends of the core material 41 are exposed from the long plate portion 31 on one side of the board support body 21. The width of the long plate portion 31 in the short side direction is wider than the width of the core material 41 in the same direction, and the peripheries of the multiple cutouts 412 of the core material 41 are exposed from the long plate portion 31 on one side of the board support body 21.

[0034] The peripheral wall portion 32 is formed to fit along the inner surface 112a of the mounting hole 112 of the rack shaft 12 and surrounds the entire long plate portion 31. A ring-shaped recess 320 is formed in the peripheral wall portion 32 at a portion corresponding to the rear side (the rack shaft 12 side) of the mounting hole 112, in which the sealing member 71 is disposed. The sealing member 71 is accommodated in the recess 320 and elastically contacts the inner surface 112a of the mounting hole 112, providing a liquid-tight seal between the inner surface 112a of the mounting hole 112 and the peripheral wall portion 32. A ring-shaped protrusion 321 to which the sealing member 72 is bonded is provided at the end of the peripheral wall portion 32 at the rear side of the mounting hole 112. The sealing member 72 is made of, for example, the same type of resin as the resin member 3, and is welded to the protrusion 321 of the peripheral wall portion 32 by laser welding or ultrasonic welding to prevent the sealing member 71 from coming off. The sealing member 72 may also be bonded to the peripheral wall portion 32 by adhesive. The substrate 5 is disposed between the sealing member 72 and the long plate portion 31 , and the space around the substrate 5 is sealed by the sealing member 72 .

[0035] 6(a) and 6(b), the thickness of the long plate portion 31 on one side of the core material 41 in the thickness direction (the side closest to the substrate 5) is equal to the thickness of the long plate portion 31 on the other side of the core material 41 in the thickness direction (the opposite side of the substrate 5). In FIG. 6(b), the thickness of the long plate portion 31 on one side of the core material 41 in the thickness direction is indicated by T1, and the thickness of the long plate portion 31 on the other side of the core material 41 in the thickness direction is indicated by T2. When the absolute value of the difference between T1 and T2 is ΔT (ΔT = |T1 - T2|), ΔT is preferably 10% or less of T1 and T2 (ΔT ≦ T1 × 0.90 and ΔT ≦ T2 × 0.90), and more preferably 5% or less (ΔT ≦ T1 × 0.95 and ΔT ≦ T2 × 0.95). Furthermore, the thickness of the long plate portion 31 on one side of the thickness direction of the core material 41 (the side facing the substrate 5) does not have to be equal to the thickness of the long plate portion 31 on the other side of the thickness direction of the core material 41 (the opposite side of the substrate 5) (for example, ΔT is 75% or less of T1 and T2).

[0036] The thickness T3 of the core material 41 is thinner than the wall thicknesses T1 and T2 of the long plate portion 31 on one and the other sides of the core material 41 in the thickness direction, and is, for example, 1.0 mm. At least a portion of the core material 41 in the thickness direction is disposed within the mounting hole 112 of the rack housing 11. In FIG. 6(b), an extension line L of the mounting surface 11a of the rack housing 11 is shown by a two-dot chain line, and this extension line L intersects with the core material 41. Note that the entire thickness direction of the core material 41 may be disposed within the mounting hole 112. By disposing at least a portion of the thickness direction of the core material 41 within the mounting hole 112 of the rack housing 11, the intrusion or leakage of electromagnetic waves from between the metal rack housing 11 and the core material 41 is suppressed.

[0037] In FIG. 10(b), the connection portions 33 are shown in gray. The connection portions 33 are thin-walled portions provided between both short-side ends of the long plate portion 31 and the peripheral wall portion 32, and are formed in the shape of grooves recessed from one side to the other side of the substrate support 21. As shown in FIG. 6(b), when the thickness of the connection portions 33 in the direction perpendicular to the core material 41 is T4 and the thickness of the long plate portion 31 in the same direction is T5, T4 is 30% to 90% of T5. By forming the connection portions 33 thinner than the long plate portion 31, the occurrence of unfilled portions such as voids and chips in the resin member 3 is suppressed.

[0038] The rib portion 35 is formed on one side and the other side of the long plate portion 31 of the substrate support 21. The rib portion 35 has a vertical rib 351 extending in the longitudinal direction of the long plate portion 31 and a plurality of horizontal ribs 352 intersecting the vertical rib 351. One vertical rib 351 is provided on each of one side and the other side of the substrate support 21. The plurality of horizontal ribs 352 are provided so as to cross between the peripheral wall portions 32 on both sides in the short direction of the long plate portion 31. The injection portion 30 is formed at a portion on the other side of the substrate support 21 where the vertical rib 351 and the horizontal rib 352 intersect. When the resin member 3 is molded, the vertical rib 351 and the plurality of horizontal ribs 352 serve as a passage for the molten resin.

[0039] The plurality of support portions 34 are formed on one side of the substrate support 21 in a portion where the vertical rib 351 is provided, and protrude toward the substrate 5 beyond the tip surface 351a of the vertical rib 351. Some of the plurality of support portions 34 are formed at the portion where the vertical rib 351 and the horizontal rib 352 intersect. As shown enlarged in FIG. 5, the support portion 34 has a cylindrical large diameter portion 341 and a small diameter portion 344, and the large diameter portion 341 is continuous with the vertical rib 351. The small diameter portion 344 is erected at the center of the tip surface 341a of the large diameter portion 341. The small diameter portion 344 is inserted into a fixing hole 55 in the substrate 5 and is prevented from slipping out of the fixing hole 55 by heat crimping. FIG. 5 shows the support portion 34 before heat crimping, and FIGS. 6 and 7 show the support portion 34 after heat crimping. The sealing member 72 is formed with a recess 720 for avoiding interference with the small diameter portion 344 of the support portion 34 after heat crimping.

[0040] A plurality of fixing portions 36 are provided on the outer periphery of the peripheral wall portion 32. In this embodiment, six fixing portions 36 are provided in the resin member 3, and a collar 42 is embedded in each fixing portion 36. The board support 21 is fixed to the rack housing 11 by threading a bolt 101 inserted through the collar 42 into a screw hole 113 formed in the rack housing 11.

[0041] Fig. 11(a) is a top view of a jig 9 used in the molding step of the resin member 3. Fig. 11(b) is a cross-sectional view of the jig 9. In Fig. 11(a), the outline of a core material 41 supported by the jig 9 is shown by a two-dot chain line.

[0042] The jig 9 has a pair of first support portions 91 that support both longitudinal ends of the core material 41, and multiple second support portions 92 that support both lateral ends of the core material 41. The first support portions 91 are formed with fitting recesses 910 into which the longitudinal ends of the core material 41 fit. The second support portions 92 are formed with protrusions 921 that fit into notches 412 formed in the lateral ends of the core material 41. The jig 9 also has stepped holes 90 formed therein for forming the support portions 34 of the resin member 3. The stepped holes 90 are formed in positions corresponding to the positions of the flow holes 411 of the core material 41. This makes it easier for molten resin to flow into the stepped holes 90.

[0043] (Actions and Effects of the Embodiments) According to the embodiment described above, the rigidity of the core material 41 suppresses warpage caused by the molten resin injected into the mold during the molding process of the resin member 3 contracting and solidifying. This maintains a constant distance between the substrate 5 and the detection body 20 even when the rack shaft 12 moves, improving the accuracy of detecting the position of the rack shaft 12. In particular, in this embodiment, the thickness of the long plate portion 31 on one side of the core material 41 in the thickness direction is equal to the thickness of the long plate portion 31 on the other side. This balances the contraction forces of the resin on one side and the other side of the core material 41 in the thickness direction, thereby suppressing curvature of the resin member 3 in the longitudinal direction. According to evaluation results by the inventors, the warpage of the resin member 3 (the dimensional difference between the longitudinal center and both longitudinal ends of the tip surface 351 a of the vertical rib 351 on one side of the substrate support 21 in the thickness direction of the core material 41) is less than 0.20 mm, and is suppressed to approximately 0.19 mm.

[0044] (Summary of the embodiment) Next, the technical ideas grasped from the above-described embodiments will be described by using the reference numerals and the like in the embodiments. However, the reference numerals in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiments.

[0045] [1] A position detection device (stroke sensor 2) for detecting the position of a moving member (rack shaft 12) moving within a housing (rack housing 11), comprising: a substrate (5) on which wiring for detecting the position of the moving member (12) is formed; and a substrate support (21) for supporting the substrate (5) relative to the housing (11), wherein the substrate (5) is disposed in a mounting hole (112) formed in the housing (11) and extends along the direction of movement of the moving member (12) relative to the housing (11), and the substrate support (21) is formed of a resin member (3) made of resin and having a plurality of support portions (34) for supporting the substrate (5) at a plurality of points, in which a core material (41) made of a material harder than the resin is embedded, and the core material (41) extends parallel to the substrate (5) along the direction of movement of the moving member (12).

[0046] [2] The position detection device (2) described in [1] above, wherein the core material (41) is a flat plate parallel to the substrate (5) and is arranged on the opposite side of the substrate (5) from the moving member (12).

[0047] [3] The position detection device (2) described in [2] above, wherein the resin member (3) integrally comprises a long plate portion (31) in which the core material (41) is embedded, a peripheral wall portion (32) provided to surround the periphery of the long plate portion (31), and a connecting portion (33) connecting the long plate portion (31) and the peripheral wall portion (32), and wherein the thickness (T4) of the connecting portion (33) in a direction perpendicular to the core material (41) is thinner than the thickness (T5) of the long plate portion (31) in the same direction.

[0048] [4] A position detection device (2) described in [3] above, wherein the thickness (T1) of the long plate portion (31) on one side of the thickness direction of the core material (41) is equal to the thickness (T2) of the long plate portion (31) on the other side of the thickness direction of the core material (41).

[0049] [5] The position detection device (2) according to any one of [1] to [4] above, wherein the substrate (5) is configured such that an excitation coil (51) that generates a spatial magnetic flux and detection coils (52, 53) that are linked with the spatial magnetic flux are formed by a wiring pattern, and an induced voltage generated in the detection coils (52, 53) changes depending on the position of the moving member (12) relative to the housing (11), and the core material (41) is made of iron or a metal having a higher conductivity than iron and has a shielding effect for the excitation coil (51) and the detection coils (52, 53).

[0050] [6] The position detection device (2) according to [5] above, wherein at least a portion of the core material (41) in the thickness direction is disposed within the mounting hole (112).

[0051] [7] A detection device (2) for detecting a physical quantity that changes depending on the state of a detection object (12) in a housing (11), comprising: a substrate (5); and a substrate support (21) that supports the substrate (5) relative to the housing (11), wherein the substrate (5) is disposed in a mounting hole (112) formed in the housing (11), and the substrate support (21) is formed of a resin member (3) made of resin and having a plurality of support portions (34) that support the substrate (5) at a plurality of points, in which a core material (41) made of a material harder than the resin is embedded, and the core material (41) extends parallel to the substrate (5).

[0052] [8] A substrate support (21) for supporting a long substrate (5), comprising: a resin member (3) made of resin having a plurality of support portions (34) for supporting the substrate (5) at a plurality of locations in the longitudinal direction of the substrate (5); and a core material (41) made of a material harder than the resin, wherein the core material (41) extends in the longitudinal direction of the substrate (5) and is embedded in the resin member (3).

[0053] [9] The substrate support (21) according to [8] above, wherein the core material (41) is made of iron or a plate-shaped metal having a higher conductivity than iron, and is arranged parallel to the substrate (5).

[0054] Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. Furthermore, the present invention can be appropriately modified and implemented without departing from the spirit of the invention, and for example, the following modifications are possible.

[0055] In the above embodiment, an example has been described in which the position detection device of the present invention is embodied as the stroke sensor 2 that detects the position of the rack shaft 12, but the present invention is not limited to this, and the position detection device of the present invention can also be used to detect the position of a moving member other than the rack shaft 12. Furthermore, the present invention can also be embodied as a detection device that detects the physical quantity of a detection target other than a moving member.

[0056] Furthermore, in the above embodiment, the case where the substrate support 21 supports the substrate 5 on which the excitation coil 51 and the first and second detection coils 52 and 53 are formed has been described. However, the substrate supported by the substrate support 21 is not limited to this, and for example, a substrate on which electronic components such as a plurality of light-emitting elements and light-receiving elements are mounted can also be supported by the substrate support of the present invention.

[0057] In the above embodiment, the core material 41 is made of a flat metal plate, but this is not limiting. The core material 41 may be made of a material harder than the resin of the resin member 3, such as a hard plastic such as acrylic, or ceramics. The shape of the core material 41 is not limited to a flat plate, and may be, for example, a rod or pipe. Furthermore, the number of core materials 41 molded into the resin member 3 may be at least one, or may be multiple. [Explanation of symbols]

[0058] 11... Rack housing (housing) 1... Steering device 112...Mounting hole 12...Rack shaft (detection target) 2... Stroke sensor (position detection device, detection device) 21... Substrate support 3...Resin member 31...Long plate portion 32... Peripheral wall portion 33... Connection portion 34...Support portion 41...Core material 5... Substrate 51... Excitation coil 52...First detection coil 53...Second detection coil

Claims

1. A position detection device for detecting the position of a moving member that moves within a housing, a substrate on which wiring for detecting a position of the movable member is formed, and a substrate support that supports the substrate relative to the housing, the substrate is disposed in a mounting hole formed in the housing and extends along a moving direction of the moving member relative to the housing; the substrate support member is a resin member made of resin having a plurality of support portions that support the substrate at a plurality of points, and a core member made of a material harder than the resin is embedded in the resin member, and the core member extends parallel to the substrate along the movement direction of the moving member; Position detection device.

2. the core material is a flat plate parallel to the substrate and is disposed on the opposite side of the substrate from the moving member side; The position detection device according to claim 1 .

3. the resin member integrally includes a long plate portion in which the core material is embedded, a peripheral wall portion provided so as to surround the periphery of the long plate portion, and a connecting portion connecting the long plate portion and the peripheral wall portion, a thickness of the connecting portion in a direction perpendicular to the core material is thinner than a thickness of the long plate portion in the same direction; The position detection device according to claim 2 .

4. the thickness of the long plate portion on one side in the thickness direction of the core material is equal to the thickness of the long plate portion on the other side in the thickness direction of the core material; The position detection device according to claim 3 .

5. the substrate is configured such that an excitation coil that generates a spatial magnetic flux and a detection coil with which the spatial magnetic flux intersects are formed by a wiring pattern, and an induced voltage generated in the detection coil changes depending on the position of the moving member with respect to the housing, the core material is made of iron or a metal having a higher conductivity than iron, and has a shielding effect for the excitation coil and the detection coil; The position detection device according to any one of claims 1 to 4.

6. At least a portion of the core material in the thickness direction is disposed within the mounting hole. The position detection device according to claim 5 .

7. A detection device for detecting a physical quantity that changes depending on the state of a detection target within a housing, comprising: a substrate; and a substrate support that supports the substrate relative to the housing, the substrate being disposed in a mounting hole formed in the housing, the substrate support being a resin member having a plurality of support portions that support the substrate at a plurality of points, the resin member having a core material embedded therein, the core material being made of a material harder than the resin, the core material extending parallel to the substrate. Detection device.

8. A substrate support for supporting a long substrate, a resin member made of resin having a plurality of support portions that support the substrate at a plurality of positions in the longitudinal direction of the substrate; and a core material made of a material harder than the resin, The core material extends in the longitudinal direction of the substrate and is embedded in the resin member. Substrate support.

9. The core material is made of iron or a plate-shaped metal having higher conductivity than iron, and is arranged parallel to the substrate. The substrate support of claim 8 .

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