Position detecting device

Abstract

To provide a position detection device capable of suppressing deterioration of detection accuracy.SOLUTION: A position detection device includes a substrate 100, a transmission coil 110, a first reception coil 120 and a second reception coil 130 arranged inside the transmission coil, and a plate-like housing part 500 for housing the substrate. The housing part has an arrangement part 511 on which the substrate is arranged, and an attachment part 512 for attaching the housing part. The arrangement portion includes rigid portions 600, 610, 620, 630, 631, 632, 633, 634, 635, 636, and 637 having a larger size in the plate thickness direction than other portions.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a position detection device. [Background technology]

[0002] Conventionally, a rotation angle detection sensor has been known that includes a sensor main body in which a coil is arranged on a plate-shaped substrate, and a rotor that is arranged opposite the sensor main body and has an encoder structure formed thereon (see, for example, Patent Document 1). This rotation angle detection sensor detects the rotation angle of the rotor based on the magnetic flux that passes through the coil, which changes as the rotor rotates and changes the width dimension of the conductor pattern of the encoder structure that faces the coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5226694 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in order to protect a plate-shaped substrate on which a coil is arranged as described in Patent Document 1, the substrate may be enclosed in an enclosure. For this reason, the inventors considered enclosing the substrate in a plate-shaped enclosure similar to the substrate. The inventors then considered placing the enclosure with the substrate enclosed in a position facing the detection body, which is the rotor, and attaching the enclosure to the surface of an attachment object that cannot rotate relative to the detection body using a fastening member such as a screw.

[0005] However, the attachment object and the enclosure member may thermally expand and deform due to temperature changes in the environment in which they are placed. When the attachment object and the enclosure member thermally expand, if the amount of deformation of the attachment object and the enclosure member differs due to the difference in the thermal expansion coefficients of the attachment object and the enclosure member, there is a risk that the plate-shaped enclosure member may warp and deform.

[0006] As a result, the substrate housed in the enclosure warps together with the enclosure, changing the distance between the detection body and the coil disposed on the substrate. This change in the distance between the detection body and the coil changes the magnetic flux passing through the coil when detecting the position of the detection body. This reduces the detection accuracy when detecting the position of the detection body.

[0007] An object of the present disclosure is to provide a position detection device that can suppress a decrease in detection accuracy. [Means for solving the problem]

[0008] The invention described in claim 1 is A position detection device, a substrate (100) disposed opposite a rotatable detection body (30); a transmitting coil (110) formed on the substrate; a first receiving coil (120) and a second receiving coil (130) disposed inside the transmitting coil in a normal direction to the surface direction of the substrate; a plate-like accommodation portion (500) that accommodates the substrate and has a plate thickness direction in the normal direction; The housing portion has a placement portion (511) in which the substrate is placed and an attachment portion (512) for attaching the housing portion, The arrangement portion has rigid portions (600, 610, 620, 630, 631, 632, 633, 634, 635, 636, 637) that are formed to be larger in size in the plate thickness direction than other portions of the arrangement portion.

[0009] This allows the rigidity of the placement section to be increased compared to a configuration in which the placement section does not have a rigid portion. Therefore, when the entire accommodation section deforms due to thermal expansion, the placement section is less likely to deform compared to a configuration in which the placement section does not have a rigid portion. Therefore, even when the entire accommodation section deforms due to thermal expansion while the mounting section is attached, the amount of deformation of the placement section is suppressed. Furthermore, the amount of deformation of the board placed on the placement section when it deforms integrally with the placement section is suppressed.

[0010] As a result, the amount of change in the distance between the detected object and each of the first and second receiving coils is reduced, and the amount of change in the magnetic flux passing through each of the first and second receiving coils when detecting the position of the detected object is reduced, thereby preventing a decrease in detection accuracy when detecting the position of the detected object.

[0011] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a block diagram of an electric motorization system configured using a position detection device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating the relationship between a position detection device and a drive unit. [Figure 3] FIG. 2 is a plan view of the rotating plate and the position detection device. [Figure 4] 1 is a perspective view of a position detection device according to a first embodiment. [Figure 5] 5 is a cross-sectional view of the position detection device taken along line VV in FIG. 4. [Figure 6] 2 is a schematic diagram showing the shapes of a transmitter coil, a first receiver coil, and a second receiver coil. FIG. [Figure 7] FIG. 2 is a block diagram of a position detection device. [Figure 8] FIG. 10 is a perspective view of a position detection device according to a second embodiment. [Figure 9] 9 is a side view of the position detection device according to the second embodiment as seen from the direction of the arrow indicated by IX in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments will be given the same reference numerals, and their description may be omitted. Furthermore, in the embodiments, when only some of the components are described, the components described in the preceding embodiments can be applied to the remaining components. The following embodiments can be partially combined with each other, even if not specifically stated, as long as there is no particular problem with the combination.

[0014] (First embodiment) This embodiment will be described with reference to Fig. 1 to Fig. 7. In this embodiment, a position detection device that detects the rotation of a detection body will be described as an example of the position detection device. Note that this embodiment will describe an example in which the position detection device is applied to an electrification system mounted on a vehicle.

[0015] [Electrification system] As shown in FIG. 1 , the electrification system includes an actuator 1, a gear 2, a drive unit 3, an ECU 4 (short for Electronic Control Unit), and a position detection device S1. The electrification system operates as follows: The actuator 1 is controlled by the ECU 4 and rotates the gear 2 under the control of the ECU 4. The drive unit 3 includes a detection body (described later) and is composed of components that operate in response to the rotation of the gear 2. The position detection device S1 detects the displacement of the detection body provided in the drive unit 3 and outputs a detection signal to the ECU 4. In this embodiment, the detection body is a rotating flat plate 30, as described later, and outputs the rotation angle of the rotating flat plate 30 to the ECU 4. The ECU 4 controls the actuator 1 taking into account the detection signal from the position detection device S1.

[0016] Next, a description will be given of the configuration of the drive unit 3 in which the position detection device S1 is disposed. In this embodiment, an example in which the position detection device S1 is disposed in a motor such as a main motor or an in-wheel motor will be described.

[0017] The driving unit 3 is assumed to be, for example, a rotor for a motor, and as shown in Fig. 2, includes a shaft 10 as a rotating shaft, a rotating plate 30, and a fixed base 40. These members 10, 30, and 40 are arranged coaxially with the axial direction Da of the shaft 10 as the center. In the following description, the axial direction Da of the shaft 10 will be simply referred to as the axial direction Da.

[0018] The shaft 10 is, for example, a drive shaft, and is made up of a cylindrical member. The shaft 10 is provided with a tire on one end side, and is arranged so that the other end side opposite the one end side faces the vehicle body. For example, in FIG. 2, the upper side of the page is the one end side of the shaft 10, and the lower side of the page is the other end side of the shaft 10. Although details are omitted, the shaft 10 is equipped with, for example, a rotating wheel and bearing members (not shown), and the rotating wheel is supported by the bearing members in a rotatable state.

[0019] The rotating flat plate 30 is made of metal and has a circular ring shape with through holes 30a formed therein. Furthermore, as shown in FIG. 3 , the rotating flat plate 30 of this embodiment has a plurality of recesses 31 evenly formed on the outer edge portion. In other words, the rotating flat plate 30 has a configuration in which a plurality of protrusions 32 are arranged on the outer edge portion along the rotation direction of the shaft 10. In other words, the rotating flat plate 30 has a configuration in which a concave-convex structure 33 having recesses 31 and protrusions 32 on the outer edge portion is formed along the rotation direction of the shaft 10.

[0020] 2, the rotating flat plate 30 is fixed to the shaft 10 with one end of the shaft 10 inserted into the through hole 30a so as to rotate with the rotation of the shaft 10. In this embodiment, the rotating flat plate 30 corresponds to the detection body.

[0021] The fixed base 40 is plate-shaped with a through-hole 40a formed therein. The other end of the shaft 10 is inserted into the through-hole 40a of the fixed base 40, and a rotating wheel (not shown) is rotatably disposed thereon. The fixed base 40 is also provided with a position detector S1 so as to face the protrusion 32 of the rotating flat plate 30 in the axial direction Da. The fixed base 40 is an object to which the position detector S1 is attached. The position detector S1 is disposed so as to have a predetermined gap (i.e., distance) d between it and the rotating flat plate 30, as shown in FIG. 3.

[0022] When the position detector S1 detects the rotation angle of the shaft 10 of the motor, the position detector S1 detects the rotation angle of the rotating plate 30, which is the detection body, thereby detecting the rotation angle of the shaft 10 that rotates integrally with the rotating plate 30. The position detector S1 is attached to the stator of the motor, which functions as the fixed base 40, for example.

[0023] [Position detection device] Next, the configuration of the position detection device S1 of this embodiment will be described. As shown in FIGS. 4 and 5, the position detection device S1 of this embodiment has a printed circuit board 100 having one surface 100a and another surface 100b. The position detection device S1 is configured such that a circuit board 200 and terminals 400 are arranged on the one surface 100a of the printed circuit board 100, and these are integrally sealed by a sealing member 500. In the following description, the normal direction to the surface direction (i.e., the board thickness direction) of the printed circuit board 100 will simply be referred to as the normal direction. Note that the normal direction of the printed circuit board 100 coincides with the axial direction Da when the position detection device S1 is mounted on the fixing base 40. Furthermore, although not particularly shown, various electronic components such as capacitors and resistors are also appropriately arranged on the printed circuit board 100.

[0024] The printed circuit board 100 of this embodiment is an arc-shaped plate. More specifically, the printed circuit board 100 is configured to coincide with the arc of an imaginary circle whose center is the shaft 10. In other words, the printed circuit board 100 is shaped such that an imaginary circle whose arc is the printed circuit board 100 coincides with a circle whose center is the shaft 10.

[0025] 6, a transmitting coil 110, a first receiving coil 120, and a second receiving coil 130 are formed on the printed circuit board 100. Also, as shown in Fig. 7, connection wiring 150 is formed on the printed circuit board 100 to connect the circuit board 200 to each of the coils 110, 120, and 130. Note that Fig. 5 simply shows each of the coils 110, 120, and 130.

[0026] Specifically, the printed circuit board 100 of this embodiment is a multilayer board in which insulating films and wiring layers are alternately stacked. Then, as shown in Fig. 6, the wiring layers formed on each layer are appropriately connected through vias 140 to form the coils 110, 120, 130, and also form connection wiring 150 that connects the coils 110, 120, 130. Hereinafter, the configurations of the transmitter coil 110, first receiver coil 120, and second receiver coil 130 of this embodiment will be described with reference to Fig. 6.

[0027] The transmitting coil 110 is wound multiple times in the normal direction and is formed in the shape of an arc frame with one direction (i.e., the circumferential direction of the printed circuit board 100) as the longitudinal direction. Note that the circumferential direction of the printed circuit board 100 coincides with the rotation direction of the shaft 10 when the position detection device S1 is provided on the fixed base 40.

[0028] The first receiver coil 120 and the second receiver coil 130 are disposed inside the transmitter coil 110 in the normal direction. The first receiver coil 120 and the second receiver coil 130 are configured by appropriately connecting different wiring layers through vias 140 so as not to interfere with each other (i.e., not to overlap within the same layer). In this embodiment, the transmitter coil 110, the first receiver coil 120, and the second receiver coil 130 are configured by connecting two adjacent wiring layers among wiring layers stacked in order by vias 140. More specifically, in this embodiment, the transmitter coil 110, the first receiver coil 120, and the second receiver coil 130 are formed by connecting the outermost wiring layer located on the side of the first surface 100a of the printed circuit board 100 with the wiring layer that is the layer next to the outermost wiring layer. 6, the wiring layer formed on the top surface of the printed circuit board 100 is indicated by a solid line, the wiring layer formed on the layer next to the top surface layer is indicated by a dotted line, and wiring layers different from the wiring layers formed on the top surface and the layer next to it are indicated by a dashed-dotted line. Note that the transmitting coil 110 is configured by connecting the top surface wiring layer and the wiring layer next to the top surface layer, but all are indicated by a solid line in FIG. 6. In reality, the transmitting coil 110 has a shape configured by drawing it with one stroke.

[0029] The first receiver coil 120 of this embodiment is formed to have a closed-loop sine wave shape in the normal direction. The second receiver coil 130 of this embodiment is formed to have a closed-loop cosine wave shape in the normal direction. As described above, the first receiver coil 120 and the second receiver coil 130 are configured by appropriately connecting different wiring layers through vias 140 so as not to interfere with each other.

[0030] Furthermore, a plurality of pads (not shown) are formed on the printed circuit board 100. As shown in FIG. 5, one end of a rod-shaped terminal 400 is connected to the printed circuit board 100 so as to be connected to the pads. The terminal 400 includes, for example, three terminals: one for power supply, one for ground, and one for output. For example, the output terminal 400 is connected to the ECU 4 and is used to output the rotation angle of the detection object to the ECU 4. The number of terminals 400 is not particularly limited, and the connection destinations can be changed as appropriate depending on the number of terminals 400.

[0031] The circuit board 200 is disposed via a bonding member (not shown) in a portion of the printed circuit board 100 different from the portions where the transmitter coil 110, the first receiver coil 120, and the second receiver coil 130 are formed. The circuit board 200 is connected to the transmitter coil 110, the first receiver coil 120, and the second receiver coil 130 via connection wiring 150 formed on the printed circuit board 100.

[0032] The circuit board 200 includes a microcomputer or the like equipped with a CPU and storage units such as ROM, RAM, and nonvolatile RAM, and is connected to the transmitting coil 110, the first receiving coil 120, and the second receiving coil 130. The circuit board 200 realizes various control operations by the CPU reading and executing programs from the ROM or nonvolatile RAM. Note that the ROM or nonvolatile RAM stores various data (e.g., initial values, lookup tables, maps, etc.) used when executing the programs. The storage medium such as the ROM is a non-transitory tangible storage medium. CPU stands for Central Processing Unit, ROM stands for Read Only Memory, and RAM stands for Random Access Memory.

[0033] 7, the circuit board 200 includes a signal processing unit 210 that is connected to the transmitting coil 110, the first receiving coil 120, and the second receiving coil 130 and performs predetermined processing. The signal processing unit 210 includes, for example, an oscillator 220, a demodulator 230, an AD converter 240, an angle calculator 250, an output unit 260, and a power supply unit 300. Note that, although an example in which signals are converted into digital signals and processed will be described below as a representative example, when analog signals are processed, the signal processing unit 210 does not need to include the AD converter 240, etc.

[0034] 4 and 5, sealing member 500 integrally seals printed circuit board 100, circuit board 200, and terminal 400 such that one end of terminal 400 connected to printed circuit board 100 and the other end opposite thereto are exposed. Sealing member 500 is formed in the shape of an arc-shaped plate with its thickness direction in the normal direction, and houses printed circuit board 100 and circuit board 200.

[0035] More specifically, like the printed circuit board 100, the sealing member 500 is configured to coincide with the arc of an imaginary circle centered on the shaft 10. In other words, the sealing member 500 is shaped so that an imaginary circle whose arc is the sealing member 500 coincides with a circle centered on the shaft 10. In the following description, the longitudinal direction of the arc forming the arc-plate-shaped sealing member 500 will be referred to as the circumferential direction Db, and the direction extending radially from the center of the arc forming the sealing member 500 will be referred to as the radial direction Dc. In addition, in the sealing member 500, the portion that is arc-plate-shaped to fit the shape of the printed circuit board 100 will be referred to as a main portion 510, and the portion that seals the terminal 400 and is intended to connect to an external connector will be referred to as a connector portion 520.

[0036] The main portion 510 is formed, for example, along the shape of the printed circuit board 100, and at least the inner edge portion is formed so as to coincide with the arc of an imaginary circle centered on the shaft 10. The connector portion 520 is, for example, formed in a substantially rectangular cylindrical shape extending along the normal direction, and has an opening 520a that exposes the other end of the terminal 400 on the side opposite to the main portion 510. The sealing member 500 is made of, for example, a thermosetting resin or a thermoplastic resin. The sealing member 500 functions as a housing that houses the printed circuit board 100. Details of the sealing member 500 will be described later.

[0037] The above is the configuration of the position detector S1 in this embodiment. As shown in Fig. 2, the position detector S1 is disposed on the fixed base 40 so as to face the rotating flat plate 30 in the axial direction Da. Specifically, as shown in Figs. 2 and 3, the position detector S1 is disposed so that, when the rotating flat plate 30 rotates, the coils 110, 120, and 130 alternate between facing and not facing the protrusions 32 of the rotating flat plate 30 in the axial direction Da. Furthermore, the sealing member 500 of the position detector S1 is disposed on the fixed base 40 so as to form a predetermined gap d between the rotating flat plate 30 and the coils 110, 120, and 130.

[0038] [Signal Processing Section] Next, the operation of the signal processing unit 210 in the circuit board 200 will be described. As shown in FIG. 7, the oscillator 220 is connected to both ends of the transmitting coil 110 and applies an AC current of a predetermined frequency. Two capacitors 161 and 162 are connected in series between both ends of the transmitting coil 110 and the oscillator 220, and the part connecting the capacitors 161 and 162 is connected to ground. The transmitting coil 110 generates a magnetic field in the axial direction Da that passes through the area surrounded by the first receiving coil 120 and the area surrounded by the second receiving coil 130. However, the manner in which the transmitting coil 110 and the oscillator 220 are connected can be changed as appropriate. For example, one capacitor may be disposed between both ends of the transmitting coil 110 and the oscillator 220.

[0039] The demodulation unit 230 is connected to both ends of the first receiving coil 120 and both ends of the second receiving coil 130. The demodulation unit 230 generates a first demodulated signal by demodulating the first voltage value V1 of the first receiving coil 120, and generates a second demodulated signal by demodulating the second voltage value V2 of the second receiving coil 130.

[0040] The AD conversion unit 240 is connected to, for example, the demodulation unit 230 and the angle calculation unit 250. The AD conversion unit 240 outputs a first converted signal S obtained by AD converting the first demodulated signal and a second converted signal C obtained by AD converting the second demodulated signal to the angle calculation unit 250. The angle calculation unit 250 calculates the rotation angle of the rotating flat plate 30 by calculating, for example, an arctangent function using the first converted signal S and the second converted signal C.

[0041] The output unit 260 outputs, for example, the rotation angle of the rotating flat plate 30 obtained by the calculation in the angle calculation unit 250 to an output terminal 400 .

[0042] The power supply unit 300 is connected to the respective units 220, 230, 240, 250, and 260 of the signal processing unit 210, and supplies power to the respective units 220, 230, 240, 250, and 260.

[0043] The basic configuration of the signal processing unit 210 has been described above.

[0044] Next, the first voltage value V1 of the first receiving coil 120 and the second voltage value V2 of the second receiving coil 130 when the rotating flat plate 30 rotates will be described.

[0045] First, an alternating current of a predetermined frequency is applied to the transmitting coil 110 from the oscillator 220. This generates a magnetic field in the axial direction Da that passes through the area surrounded by the first receiving coil 120 and the area surrounded by the second receiving coil 130. Furthermore, since the magnetic field changes due to the alternating current, the first voltage value V1 generated in the first receiving coil 120 and the second voltage value V2 generated in the second receiving coil 130 change due to electromagnetic induction.

[0046] When the convex portion 32 of the rotating flat plate 30 faces the coil 110, the first receiving coil 120, and the second receiving coil 130, an eddy current is generated in the convex portion 32, and a magnetic field caused by the eddy current is also generated. Therefore, the magnetic field passing through the portion of the magnetic field in the axial direction Da that passes through the area surrounded by the first receiving coil 120 and the area surrounded by the second receiving coil 130 that faces the convex portion 32 is canceled out by the magnetic field caused by the eddy current.

[0047] As described above, the convex portions 32 are arranged side by side at intervals in the circumferential direction Db, and concave portions 31 are formed between adjacent convex portions 32. As a result, the area facing the convex portions 32 changes as the rotating flat plate 30 rotates, and the size of the portion facing the convex portions 32 in the magnetic field in the axial direction Da that passes through the area surrounded by the first receiving coil 120 and the area surrounded by the second receiving coil 130 changes periodically. Therefore, as the rotating flat plate 30 rotates, the first voltage value V1 generated in the first receiving coil 120 and the second voltage value V2 generated in the second receiving coil 130 change periodically. In this embodiment, the first voltage value V1 generated in the first receiving coil 120 is sinusoidal because the first receiving coil 120 is formed sinusoidally. The second voltage value V2 generated in the second receiving coil 130 is cosine-shaped because the second receiving coil 130 is formed cosine-shaped.

[0048] Next, details of the sealing member 500 will be described. As described above, the sealing member 500 of this embodiment is a member that seals the printed circuit board 100 and the circuit board 200. The sealing member 500 protects the printed circuit board 100 and the circuit board 200. As shown in FIGS. 4 and 5 , the sealing member 500 has a main portion 510 in the shape of an arc plate extending in the circumferential direction Db, and a connector portion 520 that seals the terminal 400.

[0049] More specifically, the main portion 510 has an encapsulation portion 511 that extends in the circumferential direction Db and encapsulates the printed circuit board 100 and the circuit board 200, and two plate-shaped mounting portions 512 that are disposed at both ends of the main portion 510 in the circumferential direction Db and attached to the fixed base 40. The main portion 510 also has two plate-shaped connecting portions 513 that connect the two mounting portions 512 to the encapsulation portion 511, respectively. The encapsulation portion 511, the two mounting portions 512, and the two connecting portions 513 are integrally formed.

[0050] The encapsulating portion 511 has an arcuate plate shape extending in the circumferential direction Db, and both ends in the circumferential direction Db are connected to the connecting portions 513. The encapsulating portion 511 has both ends in the circumferential direction Db connected to the attachment portion 512 via the connecting portions 513. The encapsulating portion 511 corresponds to the placement portion on which the substrate is placed.

[0051] The two mounting portions 512 are portions through which fastening members are inserted to mount the position detection device S1 to the fixed base 40. Each of the two mounting portions 512 is formed with a collar portion 530 through which a fastening member is inserted to fix the sealing member 500 of the position detection device S1 to the fixed base 40. The collar portion 530 is configured by arranging a metal collar 532 in a through hole 531 that penetrates the main portion 510 in the plate thickness direction. In this embodiment, the sealing member 500 is fixed to the fixed base 40 by tightening a screw inserted through the collar 532.

[0052] The fastening members used to fasten the sealing member 500 to the fixing base 40 are not limited to screws, and fastening members other than screws, such as nuts, can be used. Furthermore, the fastening method of the sealing member 500 to the fixing base 40 is not limited to using fastening members, and methods other than fastening, such as welding or fusing, can be used.

[0053] The two mounting portions 512 are formed offset in the axial direction Da with respect to the encapsulation portion 511. That is, the two mounting portions 512 and the encapsulation portion 511 are arranged offset from each other in the axial direction Da and are formed in a stepped shape. Specifically, the two mounting portions 512 are formed offset with respect to the encapsulation portion 511 in the same direction as the direction in which the connector portion 520 protrudes from the main portion 510 in the axial direction Da. Hereinafter, the direction in which the connector portion 520 protrudes from the main portion 510 in the axial direction Da will also be referred to as a first axial direction Da1, and the direction opposite to the first axial direction Da1 in the axial direction Da will also be referred to as a second axial direction Da2. That is, the two mounting portions 512 are formed offset in the first axial direction Da1 with respect to the encapsulation portion 511.

[0054] 5, the two mounting portions 512 are formed so that the size in the plate thickness direction (i.e., the size in the axial direction Da) is larger than the size of the enclosed portion 511. Specifically, the mounting portions 512 are formed so that the size in the axial direction Da is approximately twice the size of the enclosed portion 511. However, the size in the axial direction Da of the mounting portions 512 is not limited to this, and may be smaller than twice the size of the enclosed portion 511, or may be larger than twice the size of the enclosed portion 511. Connection portions 513 are connected between each of the two mounting portions 512 and the enclosed portion 511.

[0055] The connection portions 513 are connecting members for connecting the encapsulating portion 511 and the mounting portions 512, and are formed to extend from each of the two mounting portions 512 toward the encapsulating portion 511. Specifically, the two connection portions 513 connected to each of the encapsulating portions 511 in the circumferential direction Db are formed in a plate shape extending in the axial direction Da and the circumferential direction Db, with the plate surfaces extending along the radial direction Dc. In other words, each of the two connection portions 513 is formed to be inclined in the second axial direction Da2 from each of the two mounting portions 512 toward the encapsulating portion 511.

[0056] Furthermore, the two connection portions 513 are arranged side by side with the encapsulation portion 511 and the two mounting portions 512 in the circumferential direction Db. Specifically, one of the two mounting portions 512, one of the two connection portions 513, the encapsulation portion 511, the other of the two connection portion 513, and the other of the two mounting portions 512 are arranged side by side in this order in the circumferential direction Db. Therefore, in this embodiment, the axial direction Da corresponds to the first direction, and the circumferential direction Db corresponds to the second direction. Furthermore, the radial direction Dc intersects with the axial direction Da and the circumferential direction Db. Therefore, the radial direction Dc corresponds to the third direction.

[0057] 5, the two connecting portions 513 are formed so that the size in the plate thickness direction is approximately equal to the size in the plate thickness direction of the encapsulating portion 511. In other words, the size in the plate thickness direction of the two connecting portions 513 is formed so that the size in the plate thickness direction is smaller than the size in the plate thickness direction of the mounting portion 512.

[0058] 4, the two connecting portions 513 are formed so that the size in the radial direction Dc intersecting the axial direction Da and the circumferential direction Db is smaller than the size in the radial direction Dc of the encapsulation portion 511. In other words, each of the two connecting portions 513 having a plate surface extending along the radial direction Dc is formed so that the size in the plate width direction is smaller than the size in the plate width direction of the plate-shaped encapsulation portion 511 extending in the arc direction.

[0059] Specifically, the two connecting portions 513 are formed so that the size in the radial direction Dc is approximately half the size of the size in the radial direction Dc of the enclosed portion 511. Note that the size in the radial direction Dc of the connecting portions 513 is not limited to this, and as long as it is smaller than the size in the radial direction Dc of the enclosed portion 511, it may be smaller than half the size of the enclosed portion 511, or may be larger than half the size of the enclosed portion 511.

[0060] The reason why the size of the connecting portion 513 in the radial direction Dc is formed smaller than the size of the enclosed portion 511 will be described below.

[0061] The position detection device S1 has a sealing member 500 fixed to the fixed base 40. Specifically, the position detection device S1 is fixed to the fixed base 40 by tightening a screw, which is a fastening member, inserted into a collar 532 arranged in a through hole 531 of an attachment portion 512 of the sealing member 500. Therefore, the attachment portion 512 of the position detection device S1 is fixed to the fixed base 40 in a state where it cannot move relative to the fixed base 40. In contrast, the connection portion 513 and the encapsulation portion 511 of the position detection device S1 are not directly fixed to the fixed base 40.

[0062] Here, we consider deformation of the position detection device S1 due to temperature changes occurring in the environment in which the fixed base 40 and the position detection device S1 are placed. For example, if the position detection device S1 is used in an electrification system mounted on a vehicle, temperature changes occur in the environment in which the fixed base 40 and the position detection device S1 are placed due to changes in the outside air temperature and heat generated when the devices constituting the electrification system are operating. When the environmental temperature in which the fixed base 40 and the position detection device S1 are placed rises, the sealing member 500 of the fixed base 40 and the position detection device S1 may thermally expand and deform. When the fixed base 40 and the sealing member 500 thermally expand, if there is a difference in the thermal expansion coefficients of the fixed base 40 and the sealing member 500, the amount of deformation of the fixed base 40 and the sealing member 500 will differ. For example, if the thermal expansion coefficient of the sealing member 500 is larger than that of the fixed base 40, the sealing member 500 will deform more than the fixed base 40.

[0063] However, when the mounting portion 512 of the sealing member 500 is fixed to the fixed base 40 by a fastening member, the mounting portion 512 deforms while being fixed to the fixed base 40 when the entire sealing member 500 deforms. In this case, since the mounting portion 512 of the sealing member 500 cannot move relative to the fixed base 40, when the connecting portion 513 and the enclosing portion 511 of the sealing member 500, excluding the mounting portion 512, deform, there is a risk that the connecting portion 513 and the enclosing portion 511 will be warped and deformed in the axial direction Da.

[0064] Then, as the encapsulation portion 511 warps and deforms in the axial direction Da, the printed circuit board 100 enclosed in the encapsulation portion 511 warps integrally with the encapsulation portion 511. As a result, the distance between the rotating flat plate 30, which is the detection body, and the first receiving coil 120 and the second receiving coil 130 arranged on the printed circuit board 100 changes. When the distance between the rotating flat plate 30 and the first receiving coil 120 and the second receiving coil 130 changes, the magnetic flux passing through the first receiving coil 120 and the second receiving coil 130 when detecting the rotation angle of the rotating flat plate 30 changes. This may result in a decrease in detection accuracy when detecting the rotation angle of the rotating flat plate 30.

[0065] Furthermore, when the mounting portion 512 is fixed to the fixing base 40 by a fastening member, stress generated by the thermal expansion of the sealing member 500 is concentrated on the mounting portion 512. As a result, there is a risk that the mounting portion 512 may be damaged by the stress caused by the thermal expansion.

[0066] In contrast to these, in the sealing member 500 of this embodiment, the size of the connection portion 513 in the radial direction Dc is formed smaller than the size of the encapsulation portion 511. Therefore, the rigidity of the connection portion 513 is smaller than the rigidity of the encapsulation portion 511. As a result, when the entire sealing member 500 deforms due to thermal expansion, the connection portion 513 is more likely to deform than the encapsulation portion 511.

[0067] Therefore, even if the entire sealing member 500 is deformed due to thermal expansion when the attachment portion 512 is fixed to the fixing base 40, the amount of deformation of the encapsulation portion 511 is suppressed by making the connection portion 513 into a shape that is easy to deform. Also, the amount of deformation of the printed circuit board 100 when the printed circuit board 100 enclosed in the encapsulation portion 511 deforms integrally with the encapsulation portion 511 is suppressed.

[0068] As a result, the amount of change in the distance between the rotating flat plate 30 and each of the first receiving coil 120 and the second receiving coil 130 is suppressed, and the amount of change in the magnetic flux passing through each of the first receiving coil 120 and the second receiving coil 130 when detecting the rotation angle of the rotating flat plate 30 is suppressed. This makes it possible to suppress a decrease in detection accuracy when detecting the rotation angle of the rotating flat plate 30.

[0069] Furthermore, even when stress due to thermal expansion occurs in attachment portion 512 of sealing member 500, by forming connection portion 513 in a shape that is easily deformed, it is possible to reduce the stress concentrated on attachment portion 512. Therefore, it is possible to prevent attachment portion 512 from being damaged due to the concentration of stress due to thermal expansion.

[0070] (Modification of the first embodiment) In the above-described first embodiment, an example has been described in which the connecting portion 513 is formed so that its size in the plate thickness direction is approximately equal to that of the encapsulating portion 511 and its size in the radial direction Dc is smaller than that of the encapsulating portion 511. However, this is not limiting. For example, the connecting portion 513 may be formed so that its size in the radial direction Dc is approximately equal to that of the encapsulating portion 511 and its size in the plate thickness direction is smaller than that of the encapsulating portion 511. Furthermore, the connecting portion 513 may be formed so that its size in the plate thickness direction and its size in the radial direction Dc are smaller than those of the encapsulating portion 511.

[0071] (Second embodiment) Next, a second embodiment will be described with reference to FIGS. 8 and 9. In this embodiment, the shape of the sealing member 500 is different from that of the first embodiment. Other than this, the second embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar parts to the first embodiment may be omitted.

[0072] 8 and 9, the sealing member 500 of this embodiment does not have the connecting portion 513 of the first embodiment. In contrast, the sealing member 500 of this embodiment has a plurality of ribs 600. Specifically, the rib 600 includes one inner peripheral rib 610 formed along the inner edge of the arc-plate-shaped encapsulation portion 511, and one outer peripheral rib 620 formed along the outer edge of the encapsulation portion 511. The rib 600 also includes a plurality of radial ribs 630 formed along the radial direction Dc from the inner edge toward the outer edge of the arc-plate-shaped encapsulation portion 511.

[0073] The inner circumferential rib 610 extends along the axial direction Da from the end on the inner edge of the encapsulating portion 511 toward the opposite side to the side connected to the encapsulating portion 511. That is, the inner circumferential rib 610 is formed extending along the first axial direction Da1 from the end on the inner edge of the encapsulating portion 511. The inner circumferential rib 610 is formed up to a position where the end on the first axial direction Da1 side overlaps with the end of the mounting portion 512 on the first axial direction Da1 side.

[0074] The inner circumferential rib 610 is formed from one end to the other end in the circumferential direction Db at the inner edge of the encapsulating portion 511. That is, the inner circumferential rib 610 is formed from the attachment portion 512 on one side formed at both ends of the arc-plate-shaped encapsulating portion 511 in the circumferential direction Db to the attachment portion 512 on the other side.

[0075] The outer circumferential rib 620 extends in the axial direction Da from the end on the outer edge of the encapsulation portion 511 toward the opposite side to the side connected to the encapsulation portion 511. That is, the outer circumferential rib 620 is formed extending in the first axial direction Da1 from the end on the outer edge of the encapsulation portion 511. However, the outer circumferential rib 620 is not formed to a position where its end on the first axial direction Da1 side overlaps with the end of the attachment portion 512 on the first axial direction Da1 side. That is, the size of the outer circumferential rib 620 in the axial direction Da is smaller than the size of the inner circumferential rib 610 in the axial direction Da.

[0076] The outer peripheral rib 620 is formed from one end to the other end in the circumferential direction Db at the outer edge of the encapsulation portion 511. In other words, the outer peripheral rib 620 is formed from the attachment portion 512 on one side formed at both ends of the arc-plate-shaped encapsulation portion 511 in the circumferential direction Db to the attachment portion 512 on the other side.

[0077] Therefore, the size of the axial direction Da in the portion of the encapsulation portion 511 where the inner circumferential rib 610 and the outer circumferential rib 620 are formed is larger than the size of the axial direction Da in the portion where the inner circumferential rib 610, the outer circumferential rib 620, and the radial rib 630 are not formed. In this embodiment, the inner circumferential rib 610 and the outer circumferential rib 620 function as rigid portions.

[0078] The inner circumferential rib 610 and the outer circumferential rib 620 are formed so that their sizes in the radial direction Dc are smaller than the size of the enclosing portion 511 in the radial direction Dc. Specifically, the inner circumferential rib 610 and the outer circumferential rib 620 are formed so that their sizes in the radial direction Dc are smaller than ¼ of the size of the enclosing portion 511 in the radial direction Dc. Note that the size of the inner circumferential rib 610 in the radial direction Dc is not limited to this, and as long as it is smaller than the size of the enclosing portion 511 in the radial direction Dc, it may be smaller than ¼ the size of the enclosing portion 511 or may be larger than ¼ the size of the enclosing portion 511. In this embodiment, the inner circumferential rib 610 and the outer circumferential rib 620 are formed so that their sizes in the radial direction Dc are approximately the same.

[0079] The inner circumferential rib 610 and the outer circumferential rib 620 are each formed to have a constant size in both the axial direction Da and the radial direction Dc from one end to the other end in the circumferential direction Db. A plurality of radial ribs 630 are connected to the outer side of the inner circumferential rib 610 in the radial direction Dc.

[0080] Each of the multiple radial ribs 630 protrudes from one surface 100a of the encapsulation portion 511 toward the first axial direction Da1, and is formed along the radial direction Dc from the inner edge end of the encapsulation portion 511 to the outer edge end. Therefore, the size of the axial direction Da at the portion of the encapsulation portion 511 where each of the multiple radial ribs 630 is formed is larger than the size of the axial direction Da at the portion where the inner circumferential rib 610, the outer circumferential rib 620, and the radial rib 630 are not formed. In this embodiment, the radial rib 630 functions as a rigid portion.

[0081] Furthermore, the size of each of the plurality of radial ribs 630 in the axial direction Da decreases from the inside to the outside in the radial direction Dc. That is, each of the plurality of radial ribs 630 is formed to be inclined so that the size of the axial direction Da decreases from the inside to the outside in the radial direction Dc.

[0082] The plurality of radial ribs 630 are formed on one surface 100a, lined up at predetermined intervals in the circumferential direction Db. In this embodiment, seven radial ribs 630 are formed on one surface 100a, lined up at predetermined intervals in the circumferential direction Db. In the following description, the seven radial ribs 630 formed lined up in the circumferential direction Db will also be referred to as a first radial rib 631 to a seventh radial rib 637 in the order in which they are lined up in the circumferential direction Db.

[0083] The first radial rib 631 is formed at one end of the encapsulating portion 511 in the circumferential direction Db. That is, the first radial rib 631 is connected to the attachment portion 512 connected to one side of the encapsulating portion 511 in the circumferential direction Db. The seventh radial rib 637 is formed at the other end of the encapsulating portion 511 in the circumferential direction Db. That is, the seventh radial rib 637 is connected to the attachment portion 512 connected to the other side of the encapsulating portion 511 in the circumferential direction Db.

[0084] The second radial rib 632, the third radial rib 633, the fourth radial rib 634, the fifth radial rib 635 and the sixth radial rib 636 are formed in this order in the circumferential direction Db at approximately constant intervals between the first radial rib 631 and the seventh radial rib 637.

[0085] In this embodiment, the sizes of the first to seventh radial ribs 631 to 637 in the circumferential direction Db are not constant. Specifically, the fourth radial rib 634 is formed to have the smallest size in the circumferential direction Db among the first to seventh radial ribs 631 to 637. The fourth radial rib 634 is a rib formed in approximately the center of the enclosing portion 511 in the circumferential direction Db.

[0086] In contrast, the sixth radial rib 636 is formed to have the largest size in the circumferential direction Db among the first radial rib 631 to the seventh radial rib 637. The third radial rib 633 and the fifth radial rib 635 are formed to have approximately the same size in the circumferential direction Db. The first radial rib 631, the second radial rib 632, and the seventh radial rib 637 are formed to have approximately the same size in the circumferential direction Db.

[0087] The reason why the inner peripheral rib 610, the outer peripheral rib 620, and the first to seventh radial ribs 631 to 637 are formed in the encapsulating portion 511 of this embodiment will be described below.

[0088] By forming the inner circumferential rib 610, the outer circumferential rib 620, and the first to seventh radial ribs 631 to 637 in the encapsulation portion 511 of this embodiment, the rigidity of the encapsulation portion 511 is increased compared to when these ribs are not formed. For example, when the encapsulation portion 511 has the inner circumferential rib 610 and the outer circumferential rib 620, the bending rigidity in particular in the axial direction Da can be improved compared to when the encapsulation portion 511 does not have the inner circumferential rib 610 or the outer circumferential rib 620. Furthermore, when the encapsulation portion 511 has the first to seventh radial ribs 631 to 637, the torsional rigidity as well as the bending rigidity in the axial direction Da can be improved compared to when the encapsulation portion 511 does not have the first to seventh radial ribs 631 to 637.

[0089] Therefore, when the entire sealing member 500 deforms due to thermal expansion, the encapsulation portion 511 is less likely to deform than if the inner circumferential rib 610, the outer circumferential rib 620, and the first radial rib 631 to the seventh radial rib 637 were not formed in the encapsulation portion 511.

[0090] Therefore, even if the entire sealing member 500 is deformed due to thermal expansion while the attachment portion 512 is fixed to the fixing base 40, the amount of deformation of the encapsulation portion 511 is suppressed. Furthermore, the amount of deformation of the printed circuit board 100 when the printed circuit board 100 enclosed in the encapsulation portion 511 deforms integrally with the encapsulation portion 511 is suppressed.

[0091] As a result, the amount of change in the distance between the rotating flat plate 30 and each of the first receiving coil 120 and the second receiving coil 130 is suppressed, and the amount of change in the magnetic flux passing through each of the first receiving coil 120 and the second receiving coil 130 when detecting the rotation angle of the rotating flat plate 30 is suppressed. This makes it possible to suppress a decrease in detection accuracy when detecting the rotation angle of the rotating flat plate 30.

[0092] (First modified example of the second embodiment) In the second embodiment described above, an example in which the encapsulation portion 511 is formed with the inner circumferential rib 610, the outer circumferential rib 620, and the radial rib 630 has been described. However, this is not limiting. For example, the encapsulation portion 511 may be configured to have one or two of the inner circumferential rib 610, the outer circumferential rib 620, and the radial rib 630. Specifically, the encapsulation portion 511 may be configured to have the inner circumferential rib 610 and the outer circumferential rib 620, but not the radial rib 630. Alternatively, the encapsulation portion 511 may be configured to have the inner circumferential rib 610 and the radial rib 630, but not the outer circumferential rib 620. Alternatively, the encapsulation portion 511 may be configured to have the outer circumferential rib 620 and the radial rib 630, but not the inner circumferential rib 610. Alternatively, the encapsulation portion 511 may be configured to have only one of the inner circumferential rib 610, the outer circumferential rib 620, and the radial rib 630.

[0093] (Second Modification of the Second Embodiment) In the second embodiment described above, an example has been described in which seven radial ribs 630 are formed in the encapsulation portion 511, and the size of each of the seven radial ribs 630 in the circumferential direction Db is not constant. Furthermore, an example has been described in which each of the seven radial ribs 630 is formed inclined such that the size in the axial direction Da decreases from the inside to the outside in the radial direction Dc, but this is not limiting. For example, the number of radial ribs 630 formed in the encapsulation portion 511 may be less than seven or more than seven. Furthermore, the size in the circumferential direction Db of each of the multiple radial ribs 630 formed in the encapsulation portion 511 can be changed as appropriate. For example, the size in the circumferential direction Db of each of the multiple radial ribs 630 may be constant. Furthermore, each of the seven radial ribs 630 may be formed inclined such that the size in the axial direction Da increases from the inside to the outside in the radial direction Dc, or may be formed with a constant size in the axial direction Da.

[0094] (Other embodiments) Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as follows.

[0095] In the above embodiment, the position detection device S1 is applied to an electrification system mounted on a vehicle, but the present invention is not limited to this. For example, the position detection device S1 may be mounted on a device other than a vehicle.

[0096] In the above embodiment, the position detector S1 detects the rotation angle of a rotating detection object, but the present invention is not limited to this. For example, the position detector S1 may detect the displacement of a linearly moving detection object.

[0097] In the above-described embodiment, an example in which the encapsulating portion 511 and the mounting portion 512 are formed offset in the axial direction Da has been described, but the present invention is not limited to this. For example, the encapsulating portion 511 and the mounting portion 512 do not have to be formed offset in the axial direction Da.

[0098] In the above embodiment, the sealing member 500 is formed in an arc-shaped plate shape, but the present invention is not limited to this. The shape of the sealing member 500 can be appropriately changed to a square plate shape, a circular ring shape, or the like.

[0099] In the above-described embodiment, an example has been described in which the attachment portions 512 are disposed at both ends in the circumferential direction Db of the arc-shaped encapsulation portion 511, but the present invention is not limited to this. For example, the attachment portions 512 may be disposed at positions different from both ends in the circumferential direction Db of the encapsulation portion 511.

[0100] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0101] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless they are specifically stated as essential or are clearly limited to a specific number in principle.

[0102] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., the shapes, positional relationships, etc. are not limited to those unless otherwise specified or when they are fundamentally limited to specific shapes, positional relationships, etc.

[0103] The ECU 4 and method of the present disclosure may be implemented on a special-purpose computer by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. The control unit and method of the present disclosure may be implemented on a special-purpose computer by configuring a processor with one or more dedicated hardware logic circuits. The control unit and method of the present disclosure may be implemented on one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions and a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium. [Explanation of symbols]

[0104] 100 boards 110 Transmitting Coil 120 First receiving coil 130 Second receiving coil 500 storage compartment 511 Placement section 512 Mounting part 513 Connection

Claims

1. A position detection device, a substrate (100) disposed opposite the detection body (30); a transmitting coil (110) formed on the substrate; a first receiving coil (120) and a second receiving coil (130) disposed inside the transmitting coil in a normal direction to a surface direction of the substrate; A plate-shaped accommodation portion (500) that accommodates the substrate and has a plate thickness direction in the normal direction, The housing portion has a placement portion (511) in which the substrate is placed and an attachment portion (512) for attaching the housing portion, The arrangement portion has rigid portions (600, 610, 620, 630, 631, 632, 633, 634, 635, 636, 637) formed to have a larger size in the plate thickness direction than other portions of the arrangement portion, The rigid portion is disposed at a position where at least a portion of the rigid portion overlaps with the substrate in the first direction, when the thickness direction of the plate is defined as a first direction.

2. The arrangement portion has an arc-shaped plate shape, The position detection device according to claim 1 , wherein the rigid portion is formed along at least one of an inner edge side and an outer edge side of the arrangement portion.

3. The arrangement portion has an arc-shaped plate shape, The position detection device according to claim 1 or 2, wherein when a direction in which the arc forming the arrangement portion extends is defined as a circumferential direction, a plurality of the rigid portions are provided side by side in the circumferential direction.

4. The position detection device described in claim 3, wherein the rigid portion is formed along the radial direction, where the direction extending radially from the center of the arc forming the arrangement portion is defined as the radial direction, and the size in the plate thickness direction decreases as the direction goes from the inside to the outside in the radial direction.

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