Rotation angle detection device and sensor device

Abstract

To provide a rotation angle detection device and a sensor device capable of achieving high water resistance with a low cost configuration.SOLUTION: A steering angle sensor unit 2, functioning as a rotation angle detection device and a sensor device that detect a rotational position of a steering shaft 11, comprises: a large-diameter gear 31 and a small-diameter gear 32 that rotate in conjunction with rotation of the steering shaft 11; first and second magnets 41 and 42 that are mounted on the large-diameter gear 31 and the small-diameter gear 32; first and second magnetic field detection elements 51 and 52 that detect the magnetic fields of the first and second magnets 41 and 42; and a substrate 6 on which the first and second magnetic field detection elements 51 and 52 are mounted. The first and second magnetic field detection elements 51 and 52 are sealed together with at least a part of the substrate 6 by a hot-melt adhesive 20.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a rotation angle detection device that detects the rotation angle of a rotating detection object, and a sensor device having a sensor element that detects a physical quantity. [Background technology]

[0002] BACKGROUND ART Conventionally, for example, detection devices for detecting the steering angle of a steering member of a vehicle are known from Patent Documents 1 and 2.

[0003] The position detector described in Patent Document 1 includes first and second rotating members having gear teeth meshed with a rack shaft of a steering mechanism, a first magnet attached to the first rotating member, a second magnet attached to the second rotating member, and a magnetic field detection element that detects the magnetic fields of the first and second magnets, and detects the position of the rack shaft that moves back and forth in the axial direction. The magnetic field detection element is mounted on a circuit board and disposed at a position where the rotation axis of the first rotating member intersects with the rotation axis of the second rotating member.

[0004] The rotation detection device described in Patent Document 2 has a main gear that rotates together with a steering shaft that rotates around a central axis, a first detection gear meshed with the main gear, a second detection gear meshed with the first detection gear, a first magnet that rotates integrally with the first detection gear, a second magnet that rotates integrally with the second detection gear, a first magnetic sensor that detects the magnetic field of the first magnet, a second magnetic sensor that detects the magnetic field of the second magnet, a board on which the first magnetic sensor and the second magnetic sensor are mounted, and a housing consisting of a case and a cover that accommodates these. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-141620 [Patent Document 2] Japanese Patent Application Publication No. 2023-155639 Summary of the Invention [Problem to be solved by the invention]

[0006] In a detection device configured as described above, if moisture adheres to the lead wires of the magnetic field detection element or magnetic sensor, it may adversely affect the magnetic field detection accuracy or cause short circuits. Furthermore, if moisture adheres to the circuit board, it may cause corrosion. Therefore, if the detection device is to be installed in a location where it is exposed to water splashes, it is necessary to house the magnetic field detection element, magnetic sensor, and circuit board in a housing that is liquid-tightly sealed, for example, with a sealing member. However, to reliably seal the housing, including the power lines that supply power to the magnetic field detection element and magnetic sensor and the signal lines that transmit detection signals, many waterproofing components and labor-intensive assembly work are required, which increases the cost of the device.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotation angle detection device and a sensor device that can achieve high water resistance with an inexpensive configuration. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a rotation angle detection device that detects the rotation angle of a detection object, comprising: a rotating body that rotates in accordance with the rotation of the detection object; a magnet attached to the rotating body; a magnetic field detection element that detects the magnetic field of the magnet; and a substrate on which the magnetic field detection element is mounted, wherein the magnetic field detection element is sealed together with at least a portion of the substrate by a sealing material.

[0009] Furthermore, in order to solve the above-mentioned problems, the present invention provides a sensor device comprising: a sensor element for detecting a physical quantity; an insulated wire formed by covering a metal conductor with an insulator; and a terminal connected to the metal conductor, wherein the sensor element and the terminal are sealed together with an end of the insulator with a sealing material. [Effects of the Invention]

[0010] According to the rotation angle detection device and sensor device of the present invention, it is possible to obtain high water resistance with an inexpensive configuration. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a vehicle equipped with an electric power steering device including a rotation angle detection device and a steering angle sensor unit as a sensor device according to an embodiment of the present invention; [Figure 2] FIG. 2 is an external view of a steering angle sensor unit and a steering shaft. [Figure 3] FIG. 2 is an exploded perspective view of the steering angle sensor unit. [Figure 4] FIG. 4 is an exploded perspective view of the steering angle sensor unit as seen from the opposite side to FIG. 3. [Figure 5] 1A is a plan view showing the mounting surface of the substrate and the first and second magnetic field detection elements, and FIG.1B is a plan view showing the non-mounting surface of the substrate. [Figure 6] FIG. [Figure 7] FIG. 2 is a perspective view of a portion of first to fourth terminals and first to fourth insulated wires. [Figure 8] FIG. [Figure 9] FIG. 7 is a cross-sectional view of the sub-assembly taken along line AA in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Embodiment Mode] FIG. 1 is a schematic diagram of a vehicle equipped with an electric power steering device 1 including a rotation angle detection device and a steering angle sensor unit 2 as a sensor device according to an embodiment of the present invention.

[0013] As shown in FIG. 1, the electric power steering device 1 includes a steering wheel 10 that is steered by a vehicle driver, a steering shaft 11 connected to the steering wheel 10, a steering angle sensor unit 2 for detecting the steering angle, a torque sensor 12 for detecting the steering torque, a rack shaft 13 that extends in the vehicle width direction, left and right tie rods 14 that are swingably connected to both ends of the rack shaft 13, an electric motor 15 for power assist, a speed reduction mechanism 16 that reduces the rotation of an output rotating shaft 151 of the electric motor 15 and transmits the rotation to the steering shaft 11, and a control device 17 that controls the electric motor 15.

[0014] A portion of the steering shaft 11 in the longitudinal direction is formed by a torsion bar 110, and a torque sensor 12 detects steering torque based on the amount of torsion of the torsion bar 110. An end of the steering shaft 11 is provided with pinion teeth 111 that mesh with rack teeth 131 provided on a rack shaft 13. When the steering shaft 11 rotates, the rack shaft 13 moves forward and backward in the axial direction, thereby steering the left and right steered front wheels 18, 19. Based on steering angle information obtained from the steering angle sensor unit 2 and steering torque information obtained from the torque sensor 12, a control device 17 controls the electric motor 15 so that an assist torque corresponding to the steering angle and steering torque is applied to the steering shaft 11.

[0015] The steering shaft 11 rotates together with the steering wheel 10 around its central axis. The steering angle sensor unit 2 sets the rotational position of the steering shaft 11 when the steering wheel 10 is in the neutral position as a reference position, and detects the rotation angle of the steering shaft 11 from the reference position. In this embodiment, the steering shaft 11 is the detection target whose rotation angle is detected by the steering angle sensor unit 2, and rotates 360° or more to one side and the other side from the reference position.

[0016] Fig. 2 is an external view of the steering angle sensor unit 2. Fig. 2 shows a part of the steering shaft 11 together with the steering angle sensor unit 2. Fig. 3 is an exploded perspective view of the steering angle sensor unit 2. Fig. 4 is an exploded perspective view of the steering angle sensor unit 2 as viewed from the opposite side to that of Fig. 3. Fig. 5(a) is a plan view showing the mounting surface 6a of the substrate 6 of the steering angle sensor unit 2, the first magnetic field detection element 51, and the second magnetic field detection element 52. Fig. 5(b) is a plan view showing the non-mounting surface 6b of the substrate 6.

[0017] The steering angle sensor unit 2 includes a large diameter gear 31 and a small diameter gear 32 that are meshed with each other, a first magnet 41 attached to the large diameter gear 31, a second magnet 42 attached to the small diameter gear 32, a first magnetic field detection element 51 that detects the magnetic field of the first magnet 41, a second magnetic field detection element 52 that detects the magnetic field of the second magnet 42, a substrate 6 on which the first magnetic field detection element 51 and the second magnetic field detection element 52 are mounted, and a hot melt adhesive 20 that functions as a sealant that seals the first magnetic field detection element 51 and the second magnetic field detection element 52 together with at least a part of the substrate 6. In Fig. 3 and Figs. 6 and 9 described below, the outline of the hot melt adhesive 20 is indicated by a two-dot chain line, and its internal structure is indicated by a solid line.

[0018] The steering angle sensor unit 2 also includes a cable 7 having a sheath 70 and first to fourth insulated wires 71 to 74, first to fourth terminals 75 to 78 connected to the ends of the first to fourth insulated wires 71 to 74, a device case 8 that houses the substrate 6 and the first and second magnetic field detection elements 51 and 52, and a holder 9 as a resin molded body that engages and is positioned within the device case 8. The holder 9 is formed by injection molding. The hot melt adhesive 20 functions as a sealant that seals the first magnetic field detection element 51 and the second magnetic field detection element 52, and also functions as an adhesive that adheres the holder 9 to the substrate 6. The device case 8 is formed with an outlet 80 through which the first to fourth insulated wires 71 to 74 are led out.

[0019] The substrate 6 is a printed circuit board in which wiring patterns and electrodes are formed on the surface of a plate-shaped base material 60 made of an insulating material such as FR4 (glass fiber cloth impregnated with epoxy resin and subjected to a thermosetting treatment). The first and second magnetic field detection elements 51, 52 are one form of sensor elements that detect the strength of a magnetic field as a physical quantity in the steering angle sensor unit 2 as a sensor device.

[0020] The large diameter gear 31 and the small diameter gear 32 are rotating bodies that rotate in conjunction with the rotation of the steering shaft 11. The large diameter gear 31 integrally includes a cylindrical portion 311, a disk portion 312 and a large diameter gear portion 313 provided on the outer periphery of the cylindrical portion 311, and a pair of engaging protrusions 314 provided so as to protrude inward from an inner circumferential surface 311a of the cylindrical portion 311. The disk portion 312 and the large diameter gear portion 313 are aligned in the axial direction of the cylindrical portion 311. The steering shaft 11 is inserted inside the cylindrical portion 311. The pair of engaging protrusions 314 respectively engage with a pair of grooves 112 formed in the steering shaft 11, and the large diameter gear 31 rotates integrally with the steering shaft 11.

[0021] The diameter of the disk portion 312 of the large-diameter gear 31 is larger than the diameter of the tooth tip circle of the large-diameter gear portion 313. A recess 312b is formed in the end face 312a of the disk portion 312 opposite the large-diameter gear portion 313 side, and a first magnet 41 is housed therein. A groove 311c is formed in the outer circumferential surface 311b of the cylindrical portion 311, and the groove 311c extends in the axial direction and communicates with the recess 312b. Two grooves 311c and two recesses 312b are formed in the cylindrical portion 311 and the disk portion 312, at symmetrical positions with respect to the central axis C of the steering shaft 11. One of the grooves 311c and recess 312b is shown in FIG. 4. A first magnet 41 is housed in each of the two recesses 312b.

[0022] In this embodiment, the steering angle sensor unit 2 detects the steering angle by detecting the rotational position of the steering shaft 11, but this is not limiting, and the steering angle sensor unit 2 may be configured to detect the steering angle by detecting the position in the vehicle width direction of the rack shaft 13 that moves in the axial direction. In this case, rack teeth that mesh with the large diameter gear portion 313 of the large diameter gear 31 are formed on the rack shaft 13, and the steering angle sensor unit 2 is arranged so that the large diameter gear 31 rotates as the rack shaft 13 moves in the axial direction.

[0023] The small diameter gear 32 integrally includes a gear portion 321 that meshes with the gear portion 313 of the large diameter gear 31, a cylindrical shaft portion 322 provided on one axial side of the gear portion 321, and a boss portion 323 provided on the other axial side of the gear portion 321. The pitch circle diameter of the gear portion 321 of the small diameter gear 32 is smaller than the pitch circle diameter of the gear portion 313 of the large diameter gear 31, so that when the steering shaft 11 rotates, the small diameter gear 32 rotates at a faster speed than the large diameter gear 31. The number of teeth of the gear portion 313 of the large diameter gear 31 is a non-integer multiple of the number of teeth of the gear portion 321 of the small diameter gear 32. In this embodiment, the number of teeth of the gear portion 313 of the large diameter gear 31 is 44, and the number of teeth of the gear portion 321 of the small diameter gear 32 is 26.

[0024] A recess 322b is formed in the shaft portion 322 of the small diameter gear 32, recessed in the axial direction from the tip surface 322a facing the substrate 6. A second magnet 42 is attached to the recess 322b, for example, by adhesive. The small diameter gear 32 rotates with the shaft portion 322 supported by the holder 9. The first magnet 41 and the second magnet 42 are, for example, single-sided, two-pole permanent magnets made of ferrite. Note that the method of attaching the second magnet 42 to the small diameter gear 32 is not limited to adhesive, and it may also be fixed by insert molding or snap fitting.

[0025] The holder 9 integrally includes a main plate 91 having a support hole 90 formed therein that accommodates a portion of the shaft 322 of the small-diameter gear 32 together with the second magnet 42, two protrusions 92 protruding from a surface 91a of the main plate 91 facing the board 6 toward the board 6, a pair of side walls 93 protruding from the facing surface 91a of the main plate 91 toward the board 6 so as to sandwich the two protrusions 92, a terminal holding portion 94 that holds the first to fourth terminals 75-78, and two engagement portions 95 that engage with the device case 8. The two protrusions 92 each have a large-diameter portion 921 on the main plate 91 side and a small-diameter portion 922 on the tip side. The two engagement portions 95 are protrusions formed continuously with each of the pair of side walls 93 and extend perpendicular to the main plate 91.

[0026] The first magnetic field detection element 51 is a magnetic field switch that outputs a pulsed detection signal according to the strength of the magnetic field when the first magnet 41 approaches. The second magnetic field detection element 52 is a magnetic field sensor that can detect the strength of the magnetic field perpendicular to the rotation axis of the small-diameter gear 32. The direction of the magnetic field can be determined based on the strength of the magnetic field output by the second magnetic field detection element 52. The first magnetic field detection element 51 can be, for example, a Hall element. The second magnetic field detection element 52 can be, for example, a GMR (Giant Magneto-Resistive effect) element or a TMR (Tunneling Magneto-Resistive) element. When the small-diameter gear 32 rotates at a constant speed, the strength of the magnetic field detected by the second magnetic field detection element 52 changes sinusoidally. Hereinafter, the detection signal output by the first magnetic field detection element 51 will be referred to as the "first detection signal," and the detection signal output by the second magnetic field detection element 52 will be referred to as the "second detection signal."

[0027] The first magnetic field detection element 51 outputs a first detection signal indicating that the first magnet 41 has approached multiple times while the steering wheel 10 rotates from the maximum steering angle position on one side to the other side. As described above, the number of teeth of the gear portion 313 of the large-diameter gear 31 is a non-integer multiple of the number of teeth of the gear portion 321 of the small-diameter gear 32. Therefore, the detection angle based on the phase of the second detection signal when the first magnetic field detection element 51 outputs the first detection signal differs for each first detection signal. This allows the control device 17 to determine the steering angle as an absolute angle based on the second detection signal when the first magnetic field detection element 51 outputs the first detection signal.

[0028] As an example, the first insulated wire 71 is a signal line that transmits a detection signal of the first magnetic field detection element 51, and the second insulated wire 72 is a signal line that transmits a detection signal of the second magnetic field detection element 52. The third insulated wire 73 and the second insulated wire 74 are power supply lines that supply power to the first magnetic field detection element 51 and the second magnetic field detection element 52.

[0029] The substrate 6 has a rectangular shape with the long side aligned with the large diameter gear 31 and the small diameter gear 32. Two through holes 600 are formed in the base material 60 of the substrate 6, into which the small diameter portions 922 of the two protrusions 92 of the holder 9 are respectively inserted. The mounting surface 6a of the substrate 6 is provided with a plurality of pads 61 to which the plurality of lead wires 511 of the first magnetic field detection element 51 are respectively soldered, and a plurality of pads 62 to which the plurality of lead wires 521 of the second magnetic field detection element 52 are respectively soldered.

[0030] The substrate 6 is also formed with a plurality of through holes 63 into which the first to fourth terminals 75 to 78 are inserted and soldered, respectively. Wiring patterns connecting the plurality of through holes 63 and the plurality of pads 61, 62 are provided on the mounting surface 6a and non-mounting surface 6b of the substrate 6, but the wiring patterns are not shown in FIGS. 5(a) and 5(b). A resist film made of solder resist is formed on the mounting surface 6a and non-mounting surface 6b of the substrate 6, except for the areas where the plurality of pads 61, 62 and the plurality of through holes 63 are provided. The plurality of pads 61, 62 and the plurality of through holes 63 are electrodes of the substrate 6.

[0031] The device case 8 includes a case main body 81 and a lid 82. The case main body 81 integrally includes a bottom wall portion 811, a peripheral wall portion 812 provided along the periphery of the bottom wall portion 811, a fixing portion 813 for fixing to an attachment object, two engaged portions 814 with which the two engaging portions 95 of the holder 9 respectively engage, and an outlet forming portion 815 that forms part of the outlet 80. FIG. 3 shows one of the two engaged portions 814. An insertion hole 811a through which the steering shaft 11 is inserted is formed in the bottom wall portion 811. Each engaged portion 814 is formed by a pair of protrusions 814a that extend along the inner surface 812a of the peripheral wall portion 812 in a direction perpendicular to the bottom wall portion 811, and the engaging portion 95 of the holder 9 engages between the pair of protrusions 814a.

[0032] The lid body 82 integrally includes a flat lid portion 821 facing and parallel to the bottom wall portion 811 of the case main body 81, a plurality of protruding pieces 822 having locking protrusions 822a at their tips that are locked to the case main body 81, and an outlet forming portion 823 that forms part of the outlet 80. An insertion hole 821a through which the steering shaft 11 is inserted is formed in the lid portion 821. The outlet forming portion 823 protrudes from the lid portion 821 toward the case main body 81. The locking protrusions 822a of the plurality of protruding pieces 822 are locked to a plurality of locking portions 812b formed on the peripheral wall portion 812 of the case main body 81. In this embodiment, the plurality of locking portions 812b are formed by holes formed in the peripheral wall portion 812.

[0033] The manufacturing process of the steering angle sensor unit 2 includes a sub-assembly assembling process of assembling a sub-assembly 21, which is an assembly consisting of a substrate 6 on which the first magnetic field detection element 51 and the second magnetic field detection element 52 are mounted, a cable 7, a holder 9, and a hot melt adhesive 20, and an assembly process of accommodating the sub-assembly 21, the large diameter gear 31 to which the first magnet 41 is attached, and the small diameter gear 32 to which the second magnet 42 is attached, in a case main body 81, and assembling a cover 82 to the case main body 81. Next, the configuration of the sub-assembly 21 will be described in detail with reference to FIGS.

[0034] Fig. 6 is a perspective view of the sub-assembly 21. Fig. 7 is a perspective view showing a portion of the first to fourth terminals 75 to 78 and the first to fourth insulated wires 71 to 74. Fig. 8 is an exploded perspective view of the sub-assembly 21. Fig. 9 is a cross-sectional view of the sub-assembly 21 taken along line AA in Fig. 6.

[0035] 7, the first to fourth insulated wires 71 to 74 respectively have metal conductors 711, 721, 731, and 741 and insulators 712, 722, 732, and 742 covering the metal conductors 711, 721, 731, and 741. The first to fourth terminals 75 to 78 are angle-shaped terminals bent 90° into an L shape at corners 750, 760, 770, and 780 between one end and the other end, and have conductor connecting portions 751, 761, 771, and 781 at one end connected to the metal conductors 711, 721, 731, and 741 of the first to fourth insulated wires 71 to 74, and board connecting portions 752, 762, 772, and 782 at the other end connected to the through-holes 63 of the board 6.

[0036] The first to fourth terminals 75 to 78 are parallel to the substrate 6 between the corners 750, 760, 770, 780 and the conductor connecting portions 751, 761, 771, 781, and perpendicular to the substrate 6 between the corners 750, 760, 770, 780 and the substrate connecting portions 752, 762, 772, 782. The conductor connecting portions 751, 761, 771, 781 are connected to the metal conductors 711, 721, 731, 741 of the first to fourth insulated wires 71 to 74 by crimping. The substrate connecting portions 752, 762, 772, 782 are connected to the through holes 63 of the substrate 6 by soldering.

[0037] A plurality of insertion holes 941 to 944 are formed in the terminal holding portion 94 of the holder 9, through which the portions between the corners 750, 760, 770, 780 of the first to fourth terminals 75 to 78 and the board connecting portions 752, 762, 772, 782 of the first to fourth terminals 75 to 78 are inserted. The board connecting portions 752, 762, 772, 782 of the first to fourth terminals 75 to 78 are inserted into the through holes 63 from the mounting surface 6a side of the board 6, with their tips protruding from the non-mounting surface 6b of the board 6, and are soldered to the through holes 63 with solder S (see FIG. 9).

[0038] The hot melt adhesive 20 adheres to a surface 91a of the main plate portion 91 of the holder 9 that faces the mounting surface 6a of the board 6 and to a side surface 91b on the terminal holding portion 94 side, thereby fixing the holder 9 to the board 6 and sealing the first magnetic field detection element 51 and the second magnetic field detection element 52. The hot melt adhesive 20 also covers the entire mounting surface 6a and non-mounting surface 6b of the board 6, except for the portions of the holder 9 and the main bodies 510, 520 of the first magnetic field detection element 51 and the second magnetic field detection element 52 that contact the board 6. The end surface 6c of the board 6 is also covered with the hot melt adhesive 20.

[0039] However, the present invention is not limited to this, and the hot melt adhesive 20 may cover at least a portion of the substrate 6, including the periphery of the pads 61, 62 on the mounting surface 6a of the substrate 6. In this case, a coating agent having waterproof, moisture-proof, and anti-corrosion properties may be applied or sprayed to the portion not covered with the hot melt adhesive 20 to form a coating layer.

[0040] In addition, the hot melt adhesive 20 liquid-tightly seals the first to fourth terminals 75 to 78 in the exposed portions from the insertion holes 941 to 944 of the terminal holding portion 94 of the holder 9, the metal conductors 711, 721, 731, 741 exposed from the insulators 712, 722, 732, 742 of the first to fourth insulated electric wires 71 to 74, and the ends of the insulators 712, 722, 732, 742 on the side of the first to fourth terminals 75 to 78.

[0041] In the hot melt adhesive 20, the portion that seals the insulators 712, 722, 732, and 742 is a rectangular parallelepiped insulator sealing portion 200. As shown in FIG. 9 , the length L of the portion of the insulators 712, 722, 732, and 742 covered by the insulator sealing portion 200 is longer than the outer diameter D of the insulators 712, 722, 732, and 742, and is at least twice the outer diameter D. The insulator sealing portion 200 is disposed between the outlet forming portion 815 of the case body 81 and the outlet forming portion 823 of the lid 82 so as to close the outlet 80 of the device case 8. This prevents excessive moisture from entering the device case 8 through the outlet 80.

[0042] The sub-assembly 21 is assembled by attaching the holder 9 to the substrate 6 on which the first magnetic field detection element 51 and the second magnetic field detection element 52 are mounted, holding the first to fourth terminals 75 to 78 to which the first to fourth insulated wires 71 to 74 are connected in the terminal holding portion 94 of the holder 9, soldering the substrate connection portions 752, 762, 772, 782 of the first to fourth terminals 75 to 78 to the through holes 63 of the substrate 6, and then sealing the ends of the first magnetic field detection element 51 and the second magnetic field detection element 52, the substrate 6, the first to fourth terminals 75 to 78, and the insulators 712, 722, 732, 742 with hot melt adhesive 20.

[0043] When assembling the holder 9 to the substrate 6, the small-diameter portion 922 of the protrusion 92 of the holder 9 is inserted into the through-hole 600 of the substrate 6, and the holder 9 is positioned on the substrate 6. After that, the small-diameter portion 922 is heated and crushed to perform thermal crimping, thereby fixing the holder 9 to the substrate 6. The distance between the opposing surface 91a of the main plate portion 91 and the substrate 6 is determined by the thickness of the large-diameter portion 921 of the protrusion 92. When sealing each part with the hot-melt adhesive 20, the substrate 6 on which the first magnetic field detection element 51 and the second magnetic field detection element 52 are mounted, the holder 9, the first to fourth terminals 75 to 78, and portions of the first to fourth insulated wires 71 to 74 in the longitudinal direction, including the ends of the insulators 712, 722, 732, and 742, are set in a mold, and the hot-melt adhesive 20, which has been heated to a liquid state, is filled into the cavity of the mold and solidified.

[0044] When the sub-assembly 21 is housed in the case body 81, the two engaging portions 95 of the holder 9 are respectively engaged with the two engaged portions 814 of the case body 81, and the holder 9 is positioned in the case body 81. Thereafter, the large diameter gear 31 to which the first magnet 41 is attached and the small diameter gear 32 to which the second magnet 42 is attached are housed in the case body 81, and the cover 82 is assembled to the case body 81, thereby completing the steering angle sensor unit 2.

[0045] (Actions and Effects of the Embodiments) According to the embodiment described above, the lead wires 511, 521 of the first magnetic field detection element 51 and the second magnetic field detection element 52, the first to fourth terminals 75-78, and the metal conductors 711, 721, 731, 741 exposed from the insulators 712, 722, 732, 742 of the first to fourth insulated wires 71-74 are sealed with the hot melt adhesive 20, so that corrosion and electrical short circuits caused by moisture can be prevented even if moisture enters the device case 8. This ensures the water resistance of the steering angle sensor unit 2 without using a sealing member to liquid-tightly seal the inside of the device case 8, for example, and enables the steering angle sensor unit 2 to be configured inexpensively.

[0046] Furthermore, according to this embodiment, since the insulators 712, 722, 732, and 742 are partially sealed with the hot melt adhesive 20, the first to fourth insulated wires 71 to 74 can be led out of the lead-out port 80 of the device case 8 in parallel with each other.

[0047] (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.

[0048] [1] A rotation angle detection device (steering angle sensor unit 2) that detects the rotation angle of a detection object (steering shaft 11 or rack shaft 13), comprising: a rotating body (large diameter gear 31, small diameter gear 32) that rotates in conjunction with the rotation of the detection object (11, 13); magnets (41, 42) attached to the rotating body (31, 32); magnetic field detection elements (51, 52) that detect the magnetic field of the magnets (41, 42); and a substrate (6) on which the magnetic field detection elements (51, 52) are mounted, wherein the magnetic field detection elements (51, 52) are sealed together with at least a portion of the substrate (6) by a sealing material (hot melt adhesive 20).

[0049] [2] The rotation angle detection device (2) according to the above [1], comprising insulated wires (71-74) each formed by covering a metal conductor (711, 721, 731, 741) with an insulator (712, 722, 732, 742), and terminals (75-78) connected to the metal conductor (711, 721, 731, 741) and an electrode (through hole 63) of the substrate (6), wherein ends of the terminals (75-78) and the insulator (712, 722, 732, 742) are sealed with the sealing material (20).

[0050] [3] The rotation angle detection device (2) described in [1] above, comprising a device case (8) that houses the substrate (6) and the magnetic field detection elements (51, 52), and a resin molded body (holder 9) that engages and is positioned within the device case (8), and the resin molded body (9) is fixed to the substrate (6) by the sealing material (20).

[0051] [4] The rotation angle detection device (2) according to the above item [1], comprising a plurality of the rotating bodies (31, 32), a plurality of the magnets (41, 42) respectively attached to the plurality of rotating bodies (31, 32), and a plurality of the magnetic field detection elements (51, 52) for detecting the magnetic fields of the respective magnets (41, 42), wherein the plurality of the magnetic field detection elements (51, 52) are mounted on the substrate (6), and the plurality of the magnetic field detection elements (51, 52) are sealed together with at least a part of the substrate (6) by the sealing material (20).

[0052] [5] The rotation angle detection device (2) according to any one of [1] to [4] above, wherein the sealing material (20) is a hot melt adhesive.

[0053] [6] A sensor device (2) comprising: a sensor element (51, 52) for detecting a physical quantity; insulated wires (71-74) each formed by covering a metal conductor (711, 721, 731, 741) with an insulator (712, 722, 732, 742); and terminals (75-78) connected to the metal conductor (711, 721, 731, 741), wherein the sensor element (51, 52) and the terminals (75-78) are sealed together with ends of the insulator (712, 722, 732, 742) by a sealing material (20).

[0054] [7] The sensor device (2) according to [6] above, further comprising a substrate (6) on which the sensor elements (51, 52) are mounted and to which the terminals (75-78) are connected, and at least a portion of the substrate (6) is sealed with the sealing material (20).

[0055] [8] The sensor device (2) described in [7] above, comprising: a device case (8) that houses the substrate (6) and the sensor elements (51, 52); and a resin molded body (9) that engages and is positioned within the device case (8), and the resin molded body (9) is fixed to the substrate (6) by the sealing material (20).

[0056] [9] The sensor device (2) according to the above [8], wherein the resin molded body (9) is provided with a terminal holding portion (94) that holds the terminals (75 to 78).

[0057]

[10] The sensor device (2) according to any one of [6] to [9] above, wherein the sealing material (20) is a hot melt adhesive.

[0058] 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 implemented by making appropriate modifications, for example, as follows, without departing from the spirit of the invention.

[0059] In the above embodiment, the hot melt adhesive 20 is used as a sealing material. However, any sealing material other than the hot melt adhesive 20 may be used as long as it can liquid-tightly seal the first and second magnetic field detection elements 51, 52, etc. In addition, in the above embodiment, the hot melt adhesive 20 is filled into the cavity of a mold. However, this is not limited to this. A liquid or gel hot melt may be applied and solidified without using a mold. Furthermore, in the above embodiment, the first and second magnetic field detection elements 51, 52 that detect a magnetic field are used as sensor elements that detect a physical quantity. However, the present invention can also be applied to a sensor device that uses sensor elements that detect physical quantities other than a magnetic field, such as temperature or vibration intensity. The present invention can also be applied to a position detection device that detects the position of a detection target. [Explanation of symbols]

[0060] 11...Steering shaft (detection target) 2...Steering angle sensor unit (rotation angle detection device, sensor device) 20...Hot melt adhesive (sealant) 31...Large diameter gear (rotating body) 32...Small diameter gear (rotating body) 41...First magnet 42...Second magnet 51...First magnetic field detection element 52...Second magnetic field detection element 6...Substrate 61, 62...Pads (electrodes) 63...Through hole (electrode) 71 to 74: First to fourth insulated wires 711, 721, 731, 741...Metal conductors 712, 722, 732, 742...insulators 75~78...Terminals 1 to 4 8...Device case 9...Holder (resin molded body) 94...Terminal holding part

Claims

1. A rotation angle detection device for detecting a rotation angle of a detection object, a rotating body that rotates in accordance with the rotation of the detection target, a magnet attached to the rotating body, a magnetic field detection element that detects a magnetic field of the magnet, and a substrate on which the magnetic field detection element is mounted, the magnetic field detection element is sealed together with at least a part of the substrate by a sealing material; Rotation angle detection device.

2. The insulated wire is made of a metal conductor covered with an insulator, and a terminal is connected to the metal conductor and an electrode of the substrate, the terminal and the end of the insulator are sealed with the sealing material; The rotation angle detection device according to claim 1 .

3. a device case that houses the substrate and the magnetic field detection element; and a resin molded body that is engaged with and positioned within the device case, the resin molded body is fixed to the substrate by the sealing material; The rotation angle detection device according to claim 1 .

4. a plurality of the rotating bodies, a plurality of the magnets attached to the plurality of rotating bodies, respectively, and a plurality of the magnetic field detection elements that detect the magnetic fields of the plurality of magnets, the plurality of the magnetic field detection elements being mounted on the substrate; the plurality of magnetic field detection elements are sealed together with at least a portion of the substrate by the sealing material; The rotation angle detection device according to claim 1 .

5. The sealing material is a hot melt adhesive. The rotation angle detection device according to any one of claims 1 to 4.

6. The device comprises a sensor element for detecting a physical quantity, an insulated wire formed by covering a metal conductor with an insulator, and a terminal connected to the metal conductor, the sensor element and the terminal are sealed together with an end of the insulator by a sealing material; Sensor device.

7. a substrate on which the sensor element is mounted and to which the terminals are connected; At least a portion of the substrate is sealed with the sealing material. The sensor device according to claim 6.

8. a device case that houses the substrate and the sensor element; and a resin molded body that is engaged with and positioned within the device case, the resin molded body is fixed to the substrate by the sealing material; The sensor device according to claim 7.

9. The resin molded body is provided with a terminal holding portion that holds the terminal. The sensor device according to claim 8 .

10. The sealing material is a hot melt adhesive. The sensor device according to any one of claims 6 to 9.

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