Rotation angle detection device

Abstract

A rotation angle detection device (30) comprises: a rotating member (34) that rotates about a rotation axis (CL) together with an object to be detected; a switch magnet (44) that rotates together with the rotating member (34); and a switch detection element (462) that outputs a signal corresponding to a change in a magnetic field corresponding to the rotation angle of the object to be detected, the change in magnetic field being caused by the rotation of the switch magnet (44). In an orthogonal direction (Do) that is a direction orthogonal to the rotation axis (CL), the switch magnet (44) is disposed outward of the rotation axis (CL) in the orthogonal direction (Do).

Description

Rotation Angle Detection Device Cross - reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2024 - 172499 filed on October 1, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a rotation angle detection device.

[0003] Conventionally, as described in Patent Document 1, a rotation angle detection device for an automotive brake including a housing, a rotating member, and a magnet is known. The housing houses a magnetic detection unit that detects changes in magnetic force. The rotating member is rotatably supported with respect to the housing. The magnet is held by the rotating member and rotates integrally with the rotating member. Further, the magnetic detection unit includes a stroke detection unit disposed on a substrate and a switch detection unit disposed on the substrate. Furthermore, the stroke detection unit detects the rotation angle by which the rotating member has rotated from a reference position based on the magnetic force of the magnet. The switch detection unit detects that the rotating member has rotated by a predetermined angle or more from the reference position. At least a part of the stroke detection unit is disposed at a position overlapping the magnet in a view along the axial direction of the rotation axis of the rotating member.

[0004] Japanese Unexamined Patent Application Publication No. 2019 - 70568

[0005] In the rotation angle detection device described in Patent Document 1, since the magnetic force changes only due to the rotation of the magnet, the change in magnetic force due to only the rotation of the magnet is relatively small. As a result, the minimum value of the rotation angle that can be detected by the switch detection unit, which is farther from the magnet than the stroke detection unit, becomes larger. Therefore, it is difficult to detect the rotation angle finely. Thus, the detection accuracy of the switch detection unit decreases.

[0006] An object of the present disclosure is to provide a rotation angle detection device that suppresses a decrease in the detection accuracy of the rotation angle.

[0007] According to one aspect of this disclosure, the rotation angle detection device comprises a rotating member that rotates together with the object to be detected about a rotation axis, a magnet that rotates together with the rotating member, and a detection element that outputs a signal corresponding to the change in the magnetic field due to the rotation of the magnet, wherein the magnet is positioned outside the rotation axis in the orthogonal direction, which is perpendicular to the rotation axis.

[0008] As a result, the strength of the magnetic field in the direction detected by the detection element changes not only due to the rotation of the magnet, but also due to the change in the relative distance of the detection element to the magnet. Therefore, the change in the strength of the magnetic field in the direction detected by the detection element is larger compared to the case where only the rotation of the magnet is considered. Consequently, the minimum value of the rotation angle that the detection element can detect becomes smaller, allowing for finer detection of the rotation angle. Thus, the decrease in the accuracy of rotation angle detection is suppressed.

[0009] A diagram showing the configuration of a vehicle using the rotation angle detection device of the first embodiment. A cross-sectional view of the brake pedal device of the vehicle. A cross-sectional view of the rotation angle detection device. A cross-sectional view of line IV-IV in Figure 3. A diagram showing the relationship between the rotation angle and the strength of the magnetic field in the detection direction of the switch detection element. A diagram showing the relationship between the rotation angle and the strength of the magnetic field in the detection direction of the switch detection element. A cross-sectional view of the magnet and detection unit of the comparative example. A diagram showing the relationship between the rotation angle and magnetic flux density of the comparative example. A cross-sectional view of the switch magnet and switch detection unit of the rotation angle detection device of the first embodiment. A diagram showing the relationship between the rotation angle and magnetic flux density of the comparative example and the first embodiment. A cross-sectional view of the rotation angle detection device of the second embodiment. A cross-sectional view of the rotation angle detection device of the third embodiment. A cross-sectional view of the rotation angle detection device. A cross-sectional view of the rotation angle detection device of the fourth embodiment.

[0010] The embodiments will be described below with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numeral, and their descriptions will be omitted.

[0011] (First Embodiment) The rotation angle detection device of this embodiment suppresses a decrease in the accuracy of rotation angle detection. This rotation angle detection device is used, for example, in the brake pedal device of a vehicle. First, this vehicle will be described.

[0012] As shown in Figure 1, the vehicle 10 is equipped with a brake pedal device 20, an ECU 80, and a brake system 90.

[0013] As shown in Figures 1 and 2, the brake pedal device 20 is, for example, a suspended or pendant type. Therefore, the brake pedal 25, described later, rotates in response to an increase in the driver's force on the brake pedal 25, with the portion of the brake pedal 25 that is rear of the vehicle 10 relative to the rotation axis CL rotating towards the floor side or the dashboard panel side (not shown) inside the vehicle 10.

[0014] Specifically, the brake pedal device 20 comprises a brake pedal 25, a rotation angle detection device 30, a pedal housing 60, and an elastic member 70.

[0015] The brake pedal 25 corresponds to the object to be detected and rotates around the rotation axis CL. The brake pedal 25 also includes a lever portion 27 and a pad 29.

[0016] The lever portion 27 is formed from metal or the like in a rod or plate shape. The pad 29 is made of resin, rubber or the like. Furthermore, the pad 29 is connected to the lower part of the lever portion 27 of the vehicle. The pad 29 is also stepped on by the driver of the vehicle 10.

[0017] The rotation angle detection device 30 is positioned on the rotation axis CL. Furthermore, the rotation angle detection device 30 detects the rotation angle of the brake pedal 25. The rotation angle detection device 30 also outputs a signal corresponding to the detected rotation angle to the ECU 80, which will be described later. Details of the rotation angle detection device 30 will be described later.

[0018] The pedal housing 60 is formed in a box shape from resin or the like. Furthermore, the pedal housing 60 is attached to the dashboard panel (not shown) of the vehicle 10. The pedal housing 60 also supports the upper part of the lever portion 27 of the brake pedal 25 so that it can rotate around the rotation axis CL. Furthermore, a rotation angle detection device 30 is attached to the pedal housing 60.

[0019] As shown in Figure 2, the elastic member 70 is housed in the pedal housing 60. The elastic member 70 is, for example, a coil spring. Furthermore, one end of the elastic member 70 is supported by the lever portion 27. The other end of the elastic member 70 is supported by the portion of the inner wall of the pedal housing 60 that faces the lever portion 27. Therefore, when the brake pedal 25 rotates, the elastic member 70 elastically deforms due to the force from the brake pedal 25, thereby generating a reaction force to the driver's pedaling force on the vehicle 10.

[0020] Returning to Figure 1, the ECU 80 is mainly composed of a microcontroller and includes a CPU, ROM, flash memory, RAM, I / O, communication interface, and bus lines connecting these components. Furthermore, the ECU 80 acquires a signal from the rotation angle detection device 30. This activates the ECU 80. The ECU 80 also controls the brake system 90 based on the signal from the rotation angle detection device 30. In this way, the ECU 80 controls the braking of the vehicle 10.

[0021] The brake system 90 is either a hydraulic system in which the brake pedal device 20 and a master cylinder (not shown) are directly connected, or a by-wire system in which the brake pedal device 20 and the master cylinder are not connected and the master cylinder is driven using electrical signals. Furthermore, the brake system 90 brakes the vehicle 10 in response to signals from the ECU 80.

[0022] As described above, the vehicle 10 is configured as described. Next, the details of the rotation angle detection device 30 will be explained with reference to Figures 3 to 6.

[0023] As shown in Figures 3 and 4, the rotation angle detection device 30 comprises a connecting member 32, a rotating member 34, a stroke magnet 36, a stroke soft magnetic material 38, a stroke detection unit 40, and stroke wiring 42. The rotation angle detection device 30 also comprises a switch magnet 44, a switch detection unit 46, a switch wiring 48, and a housing 50.

[0024] Here, let Da be the axial direction in which the rotation axis CL extends. Let Do be the orthogonal direction perpendicular to the axial direction Da.

[0025] The connecting member 32 is connected to the lever portion 27 near the rotation axis CL. Therefore, the connecting member 32 rotates together with the brake pedal 25 around the rotation axis CL. Furthermore, the connecting member 32 extends in the axial direction Da.

[0026] The rotating member 34 is connected to the lever portion 27 via a connecting member 32. Therefore, the rotating member 34 rotates together with the brake pedal 25 and the connecting member 32 around the rotation axis CL. The rotating member 34 is formed in the shape of a plate extending in the orthogonal direction Do, for example, from metal.

[0027] The stroke magnet 36 is formed in a prismatic shape. Furthermore, the stroke magnet 36 is attached to the periphery of the rotation axis CL of the rotating member 34. Therefore, the stroke magnet 36 rotates together with the brake pedal 25, the connecting member 32, and the rotating member 34 around the rotation axis CL.

[0028] The soft magnetic material 38 for the stroke is made of a material with relatively high magnetic permeability and is formed in a plate shape. The two stroke magnets 36 face each other in a direction Do perpendicular to each other, and the two soft magnetic materials 38 for the stroke face each other in a direction Do perpendicular to each other, so that the soft magnetic materials 38 for the stroke are connected to the stroke magnets 36. In this way, the soft magnetic materials 38 for the stroke form a magnetic circuit with the stroke magnets 36. Furthermore, the soft magnetic materials 38 for the stroke are attached to the rotating member 34 together with the stroke magnets 36. For this reason, the soft magnetic materials 38 for the stroke rotate together with the brake pedal 25, the connecting member 32, the rotating member 34 and the stroke magnets 36 around the rotation axis CL.

[0029] The stroke detection unit 40 includes a stroke package 400 and a stroke detection element 402. The stroke package 400 is made of resin or the like. The stroke package 400 also covers the stroke detection element 402, which will be described later.

[0030] The stroke detection element 402 is, for example, a Hall element. However, the stroke detection element 402 is not limited to a Hall element, and may be a magnetoresistive element such as a TMR element, GMR element, or AMR element. TMR stands for Tunnel Magneto Resistive. GMR stands for Giant Magneto Resistive. AMR stands for Anisotropic Magneto Resistive.

[0031] Furthermore, the stroke detection element 402 is positioned on the rotation axis CL and surrounded by the stroke magnet 36 and the stroke soft magnetic material 38. The stroke detection element 402 also detects the strength of the magnetic field in a specific direction. The direction of the magnetic field detected by the stroke detection element 402 is perpendicular to the axial direction Da, that is, parallel to the orthogonal direction Do.

[0032] Furthermore, as the brake pedal 25 rotates, the stroke magnet 36 rotates. At this time, the strength of the magnetic field generated by the stroke magnet 36 changes in the direction of the magnetic field detected by the stroke detection element 402, which is the magnetic field that passes through the stroke detection element 402. This change in the strength of the magnetic field corresponds to the rotation angle of the brake pedal 25.

[0033] Therefore, the stroke detection element 402 detects a change in the magnetic field corresponding to the rotation angle of the brake pedal 25, which is a change in the magnetic field caused by the rotation of the stroke magnet 36. The stroke detection element 402 also outputs a signal corresponding to this detected change in the magnetic field to the ECU 80 via the stroke wiring 42. The ECU 80 uses this signal from the stroke detection element 402 to calculate the stroke amount of the brake pedal 25. Furthermore, the ECU 80 controls the brake system 90 based on this calculated stroke amount. The stroke amount is, for example, the translational movement of the brake pedal 25 toward the front of the vehicle 10.

[0034] The switch magnet 44 is formed in a prismatic shape. Furthermore, in the orthogonal direction Do, the switch magnet 44 is positioned outside the rotation axis CL and the stroke magnet 36 in the orthogonal direction Do. As a result, the switch magnet 44 is separated from the stroke magnet 36. Moreover, when the switch magnet 44 is projected in the orthogonal direction Do, the projected switch magnet 44 overlaps with the stroke magnet 36 or the stroke soft magnetic material 38. In addition, the magnetization direction of the switch magnet 44 is perpendicular to the axial direction Da. Furthermore, the switch magnet 44 is attached to the rotating member 34. For this reason, the switch magnet 44 rotates about the rotation axis CL together with the brake pedal 25, the connecting member 32, the rotating member 34, the stroke magnet 36, and the stroke soft magnetic material 38.

[0035] The switch detection unit 46 includes a switch package 460 and a switch detection element 462. The switch package 460 is made of resin or the like. The switch package 460 also covers the switch detection element 462, which will be described later.

[0036] The switch detection element 462 is, for example, a Hall element. However, the switch detection element 462 is not limited to a Hall element, and may be a magnetoresistive element such as a TMR element, GMR element, or AMR element.

[0037] Furthermore, the switch detection element 462 is positioned outside the direction of the switch magnet 44 in the orthogonal direction Do. Therefore, the distance from the rotation axis CL to the switch detection element 462 in the orthogonal direction Do is longer than the distance from the rotation axis CL to the switch magnet 44 in the orthogonal direction Do. In addition, the switch detection element 462 is positioned on a plane that passes through the switch magnet 44 and is perpendicular to the axial direction Da. Furthermore, the switch detection element 462 detects the strength of the magnetic field in a specific direction.

[0038] Here, the direction of the magnetic field detected by the switch detection element 462 is defined as the switch detection direction Dsw. The magnetization direction of the switch magnet 44 is defined as the switch magnetization direction Dmw.

[0039] Furthermore, the switch detection direction Dsw is perpendicular to the axial direction Da, that is, parallel to the orthogonal direction Do. Also, the switch detection direction Dsw is parallel to the switch magnetization direction Dmw when the switch magnet 44 rotates and approaches the switch detection element 462 most closely.

[0040] Furthermore, as the brake pedal 25 rotates, the switch magnet 44 rotates. At this time, the strength of the magnetic field generated by the switch magnet 44 that passes through the switch detection element 462 changes in the switch detection direction Dsw. This change in the strength of the magnetic field corresponds to the rotation angle of the brake pedal 25.

[0041] Therefore, the switch detection element 462 detects a change in the magnetic field corresponding to the rotation angle of the brake pedal 25, which is a change in the magnetic field caused by the rotation of the switch magnet 44. The switch detection element 462 also outputs a signal corresponding to this detected change in the magnetic field to the ECU 80 via the switch wiring 48. This starts up the ECU 80 from a stopped state. For example, the stopped ECU 80 starts up when it receives a signal from the switch detection element 462 indicating that the rotation angle of the brake pedal 25 has changed from less than a predetermined angle to greater than or equal to a predetermined angle. The predetermined angle is set through experiments or simulations so that the stopped ECU 80 is properly started up.

[0042] Furthermore, the position of the switch magnet 44 when the brake pedal 25 is not pressed is taken as the reference position. The brake pedal 25 and the switch magnet 44 have rotated several degrees from this reference position, and this is considered to be immediately after the brake pedal 25 has been pressed.

[0043] The relative positions of the switch magnet 44 and the switch detection element 462 are adjusted so that the value of the signal output from the switch detection element 462 changes immediately after the brake pedal 25 is pressed.

[0044] Therefore, for example, as shown in FIG. 5, immediately after the brake pedal 25 is depressed, the strength of the magnetic field in the switch detection direction Dsw of the magnetic field generated by the switch magnet 44 and passing through the switch detection element 462 increases. As a result, immediately after the brake pedal 25 is depressed, H_Dsw changes from less than H_Dsw_th to greater than or equal to H_Dsw_th. For this reason, immediately after the brake pedal 25 is depressed, when the rotation angle of the brake pedal 25 changes from less than a predetermined angle to greater than or equal to the predetermined angle, the switch detection element 462 outputs a signal to the ECU 80. Therefore, immediately after the brake pedal 25 is depressed, the ECU 80 in the stopped state is activated. Note that H_Dsw is the strength of the magnetic field in the switch detection direction Dsw passing through the switch detection element 462. H_Dsw_th is the strength of the magnetic field in the switch detection direction Dsw corresponding to the above-mentioned predetermined angle.

[0045] Further, for example, as shown in FIG. 6, immediately after the brake pedal 25 is depressed, the strength of the magnetic field in the switch detection direction Dsw of the magnetic field generated by the switch magnet 44 and passing through the switch detection element 462 decreases. As a result, immediately after the brake pedal 25 is depressed, H_Dsw changes from greater than or equal to H_Dsw_th to less than H_Dsw_th. For this reason, immediately after the brake pedal 25 is depressed, when the rotation angle of the brake pedal 25 changes from less than a predetermined angle to greater than or equal to the predetermined angle, the switch detection element 462 outputs a signal to the ECU 80. Therefore, immediately after the brake pedal 25 is depressed, the ECU 80 in the stopped state is activated.

[0046] Therefore, immediately after the brake pedal 25 is depressed, the value of the signal output from the switch detection element 462 changes, making it easier to activate the ECU 80 in the stopped state.

[0047] Returning to FIG. 3, the housing 50 is formed of resin or the like. Further, the housing 50 is attached to the pedal housing 60. The housing 50 also has a housing plate portion 500, a stroke accommodating portion 502, and a switch accommodating portion 504.

[0048] The housing plate portion 500 is formed in a plate shape extending in the orthogonal direction Do. The stroke housing portion 502 extends from the housing plate portion 500 in the axial direction Da. Furthermore, the stroke housing portion 502 covers a part of the stroke package portion 400 and the stroke wiring 42. Thus, the stroke housing portion 502 houses the stroke detection portion 40. In addition, the stroke housing portion 502, together with the housing plate portion 500, houses the stroke wiring 42.

[0049] The switch housing 504 extends axially Da from the housing plate 500. Furthermore, the switch housing 504 covers a portion of the switch package 460 and the switch wiring 48. Thus, the switch housing 504 houses the switch detection unit 46. The stroke housing 502, together with the housing plate 500, houses the switch wiring 48.

[0050] As described above, the rotation angle detection device 30 of the first embodiment is configured as described. Next, it will be explained how the rotation angle detection device 30 suppresses a decrease in the accuracy of rotation angle detection.

[0051] In the rotation angle detection device described in Patent Document 1, as shown in Figure 7, the magnetic force changes solely due to the rotation of the magnet. As shown in Figure 8, the change in magnetic force due to the rotation of the magnet alone is relatively small. As a result, the minimum value of the rotation angle that can be detected by the switch detection unit, which is further away from the magnet than the stroke detection unit, becomes larger. Therefore, it is difficult to detect the rotation angle precisely. Consequently, the detection accuracy of the switch detection unit decreases.

[0052] In contrast, the rotation angle detection device 30 of this embodiment comprises a rotating member 34, a switch magnet 44, and a switch detection element 462. The switch magnet 44 corresponds to a magnet and a first magnet. The switch detection element 462 corresponds to a detection element and a first detection element.

[0053] Furthermore, the switch magnet 44 is positioned outside the rotation axis CL in the orthogonal direction Do.

[0054] As a result, as shown in Figure 9, the strength of the magnetic field in the switch detection direction Dsw changes not only due to the rotation of the switch magnet 44, but also due to the change in the relative distance of the switch detection element 462 to the switch magnet 44. Therefore, as shown in Figure 10, the change in the strength of the magnetic field in the switch detection direction Dsw is larger compared to the case where only the switch magnet 44 rotates. Consequently, the minimum value of the rotation angle that the switch detection element 462 can detect becomes smaller, allowing for finer detection of the rotation angle. Thus, a decrease in the accuracy of rotation angle detection is suppressed.

[0055] Furthermore, the first embodiment also provides the following effects.

[0056] [1-1] The distance from the rotation axis CL to the switch detection element 462 in the orthogonal direction Do is longer than the distance from the rotation axis CL to the switch magnet 44 in the orthogonal direction Do.

[0057] As a result, when the stroke magnet 36 is positioned on the rotation axis CL, the switch detection element 462 is relatively far from the stroke magnet 36. Therefore, the switch detection element 462 is less affected by the magnetic field generated by the stroke magnet 36. Consequently, a decrease in the detection accuracy of the switch detection element 462 is suppressed.

[0058] Furthermore, temperature changes in the switch detection element 462 due to environmental temperature changes and driving, as well as aging of the switch detection element 462, can cause misalignment of the switch detection element 462. Moreover, it is assumed that the distance from the rotation axis CL in the orthogonal direction Do to the switch detection element 462 is less than or equal to the distance from the rotation axis CL in the orthogonal direction Do to the switch magnet 44. In this case, the distance from the rotation axis CL in the orthogonal direction Do to the switch detection element 462 becomes relatively short. Therefore, when misalignment of the switch detection element 462 occurs in this case, the angular deviation of the orientation of the switch detection element 462 becomes large, resulting in a large change in the switch detection direction Dsw. This reduces the detection accuracy of the switch detection element 462.

[0059] In contrast, in the first embodiment, by using the above length relationship, the distance from the rotation axis CL to the switch detection element 462 in the orthogonal direction Do becomes relatively long. Therefore, when a positional displacement occurs in the switch detection element 462, the angular displacement of the orientation of the switch detection element 462 becomes small, and thus the change in the switch detection direction Dsw becomes small. Consequently, the decrease in the detection accuracy of the switch detection element 462 is suppressed.

[0060] Furthermore, it is assumed that the distance from the rotation axis CL in the orthogonal direction Do to the switch detection element 462 is less than or equal to the distance from the rotation axis CL in the orthogonal direction Do to the switch magnet 44. In this case, the distance from the rotation axis CL in the orthogonal direction Do to the switch magnet 44 becomes relatively long, and the range of movement due to the rotation of the switch magnet 44 becomes relatively large. For this reason, the size of the rotation angle detection device 30 becomes larger.

[0061] In contrast, in the first embodiment, by using the above-described length relationship, the distance from the rotation axis CL to the switch magnet 44 becomes relatively short. As a result, the range of movement due to the rotation of the switch magnet 44 becomes relatively small. Therefore, an increase in the size of the rotation angle detection device 30 is suppressed.

[0062] [1-2] The switch detection direction Dsw is parallel to the magnetization direction of the switch magnet 44 when it is closest to the switch detection element 462 due to its rotation. Furthermore, the magnetization direction of the switch magnet 44 is perpendicular to the axial direction Da. Note that the terms parallel and perpendicular include the manufacturing tolerance range.

[0063] As a result, compared to the case where the above directions are not parallel, the maximum strength of the magnetic field in the switch detection direction Dsw, which is generated by the switch magnet 44 and passes through the switch detection element 462, becomes larger. Therefore, the change in the magnetic field detected by the switch detection element 462 becomes larger. Consequently, the minimum value of the rotation angle that the switch detection element 462 can detect becomes smaller. Therefore, the rotation angle can be detected more precisely. Thus, the decrease in detection accuracy of the switch detection element 462 is suppressed.

[0064] [1-3] The switch detection element 462 is a Hall element. Since Hall elements are relatively inexpensive, the cost of the switch detection element 462 can be reduced. This reduces the cost of the rotation angle detection device 30.

[0065] [1-4] The switch detection element 462 is a magnetoresistive element. As magnetoresistive elements have relatively high detection accuracy, a decrease in the detection accuracy of the switch detection element 462 is suppressed.

[0066] [1-5] The signal output from the switch detection element 462 is used to activate the ECU 80, which controls the braking of the vehicle 10. Also, immediately after the brake pedal 25 is operated, the value of the signal output from the switch detection element 462 changes. The ECU 80 corresponds to the control unit.

[0067] This allows the ECU 80, which is in a stopped state, to be activated immediately after the brake pedal 25 is operated. As a result, power consumption by the ECU 80 is suppressed, and the activation of the ECU 80 is faster, thus suppressing a decrease in the drivability of the vehicle 10.

[0068] [1-6] The rotation angle detection device 30 includes a stroke magnet 36 and a stroke detection element 402. The signal output from the stroke detection element 402 is used to calculate the stroke amount of the brake pedal 25. This allows the calculation of the stroke amount in addition to starting the ECU 80. The stroke magnet 36 corresponds to the second magnet. The stroke detection element 402 corresponds to the second detection element.

[0069] [1-7] The rotation angle detection device 30 is equipped with a soft magnetic material 38 for stroke. The soft magnetic material 38 for stroke forms a magnetic circuit with the stroke magnet 36. Furthermore, when the stroke magnet 36 and the soft magnetic material 38 for stroke are projected in the orthogonal direction Do, the projected stroke magnet 36 and the soft magnetic material 38 for stroke overlap with the switch magnet 44.

[0070] As a result, the magnetic field generated by the switch magnet 44 and directed toward the stroke magnet 36 is absorbed by the stroke soft magnetic material 38. Also, the magnetic field generated by the stroke magnet 36 and directed toward the switch magnet 44 is absorbed by the stroke soft magnetic material 38. For these reasons, the mutual influence between the magnetic field of the switch magnet 44 and the magnetic field of the stroke magnet 36 is suppressed. Consequently, a decrease in the detection accuracy of the stroke detection element 402 and the switch detection element 462 is suppressed.

[0071] (Second Embodiment) In the second embodiment, as shown in Figure 11, the shape of the rotating member 34 differs from that of the first embodiment. Also, the positional relationship between the stroke magnet 36, the stroke soft magnetic material 38, and the switch magnet 44 differs from that of the first embodiment. Other than these differences, it is the same as the first embodiment.

[0072] The rotating member 34 has a base portion 340, a first extension portion 341, and a second extension portion 342. The base portion 340 is formed in a plate shape extending in the orthogonal direction Do.

[0073] The first extension 341 is connected to the base 340 at a point on the outside in the direction Do, orthogonal to the stroke magnet 36 and the stroke soft magnetic material 38. Furthermore, the first extension 341 extends from the base 340 in the axial direction Da.

[0074] The second extension 342 is connected to the first extension 341. The second extension 342 also extends from the first extension 341 in a direction perpendicular to the first extension 341, towards the stroke magnet 36 and the stroke soft magnetic material 38.

[0075] Furthermore, the switch magnet 44 is attached to the second extension 342. As a result, when the switch magnet 44 is projected in the axial direction Da, the projected switch magnet 44 overlaps with the stroke magnet 36 or the stroke soft magnetic material 38.

[0076] As described above, the rotation angle detection device 30 of the second embodiment is configured as described. This second embodiment also provides the same effects as the first embodiment. Furthermore, the second embodiment also provides the effects described below.

[0077] [2] When the switch magnet 44 is projected in the axial direction Da, the projected switch magnet 44 overlaps with the stroke magnet 36.

[0078] This makes it possible to reduce the size of the rotation angle detection device 30 in the orthogonal direction Do compared to the case where the stroke magnet 36 and the switch magnet 44 are aligned in the orthogonal direction Do.

[0079] (Third Embodiment) In the third embodiment, as shown in Figures 12 and 13, the positional relationship between the switch magnet 44 and the switch detection element 462 is different from that of the first embodiment. Otherwise, it is the same as the first embodiment.

[0080] Specifically, the switch detection element 462 is not positioned on a plane perpendicular to the axial direction Da while passing through the switch magnet 44. Therefore, the shortest distance from the switch magnet 44 to the switch detection element 462 in the axial direction Da is greater than zero.

[0081] As described above, the rotation angle detection device 30 of the third embodiment is configured as described above. This third embodiment also provides the same effects as the first embodiment.

[0082] (Fourth Embodiment) In the fourth embodiment, as shown in Figure 14, the shape of the switch magnet 44 is different from that of the first embodiment. Otherwise, it is the same as the first embodiment.

[0083] Specifically, the switch magnet 44 is formed in a cylindrical shape instead of a rectangular prism shape.

[0084] As described above, the rotation angle detection device 30 of the fourth embodiment is configured as described above. This fourth embodiment also provides the same effects as the first embodiment.

[0085] (Other Embodiments) This disclosure is not limited to the embodiments described above, and modifications can be made to these embodiments as appropriate. Furthermore, it goes without saying that, in each of the embodiments described above, the elements constituting the embodiment are not necessarily essential, except in cases where they are explicitly stated to be particularly essential or where they are clearly essential in principle.

[0086] In each of the above embodiments, the brake pedal device 20 is of the suspended or pendant type. However, the brake pedal device 20 is not limited to being of the suspended or pendant type, and may be of the organ type. In this case, when the brake pedal 25 rotates, the portion of the brake pedal 25 that is in front of the rotation axis CL of the vehicle 10 rotates towards the floor side or the dashboard panel side of the vehicle 10 in accordance with the increase in the driver's pedaling force of the vehicle 10.

[0087] In each of the above embodiments, the elastic member 70 is a coil spring. However, the elastic member 70 is not limited to a coil spring; for example, it may be made of rubber or the like.

[0088] In each of the above embodiments, the number of elastic members 70 is one. However, the number of elastic members 70 is not limited to one, and may be two or more.

[0089] In each of the above embodiments, the switch detection element 462 is positioned outside the orthogonal direction Do compared to the switch magnet 44. However, the switch detection element 462 is not limited to being positioned outside the orthogonal direction Do compared to the switch magnet 44. The switch detection element 462 may be positioned between the rotation axis CL and the switch magnet 44 in the orthogonal direction Do. In this case, the distance from the rotation axis CL to the switch detection element 462 in the orthogonal direction Do is shorter than the distance from the rotation axis CL to the switch magnet 44 in the orthogonal direction Do.

[0090] In each of the above embodiments, the switch magnet 44 is separated from the stroke magnet 36. In contrast, the switch magnet 44 is not limited to being separated from the stroke magnet 36, but may be in contact with the stroke magnet 36.

[0091] In each of the above embodiments, the object to be detected is the brake pedal 25. However, the object to be detected is not limited to the brake pedal 25. The object to be detected may be, for example, the electronic throttle of the vehicle 10.

[0092] In the first embodiment described above, the magnetization direction and switch detection direction Dsw of the switch magnet 44 are perpendicular to the axial direction Da. In contrast, the magnetization direction and switch detection direction Dsw of the switch magnet 44 are not limited to being perpendicular to the axial direction Da, but may be parallel to the axial direction Da.

[0093] The above embodiments may be combined as appropriate.

[0094] (Perspective of this Disclosure) [Perspective 1] A rotation angle detection device comprising: a rotating member (34) that rotates together with a detection target (25) about a rotation axis (CL); a magnet (44) that rotates together with the rotating member; and a detection element (462) that outputs a signal corresponding to a change in the magnetic field due to the rotation of the magnet, wherein the magnet is positioned outside the rotation axis in the orthogonal direction (Do), which is perpendicular to the rotation axis. [Perspective 2] The rotation angle detection device according to Perspective 1, wherein the magnet is a first magnet, the detection element is a first detection element, and the rotation angle detection device comprises a second magnet (36) that rotates together with the rotating member and the first magnet, and a second detection element (402) that outputs a signal corresponding to the change in the magnetic field due to the rotation of the second magnet, wherein when the first magnet is projected in the direction (Da) from which the rotation axis extends, the projected first magnet overlaps with the second magnet. [Perspective 3] The rotation angle detection device according to Perspective 1 or 2, wherein the distance from the rotation axis to the detection element in the orthogonal direction is longer than the distance from the rotation axis to the magnet in the orthogonal direction. [Perspective 4] The rotation angle detection device according to any one of Perspectives 1 to 3, wherein the direction (Dsw) of the magnetic field detected by the detection element is parallel to the magnetization direction of the magnet when the magnet approaches the detection element as it rotates. [Perspective 5] The rotation angle detection device according to Perspective 4, wherein the magnetization direction of the magnet is perpendicular to the direction (Da) in which the rotation axis extends. [Perspective 6] The rotation angle detection device according to any one of Perspectives 1 to 5, wherein the detection element is a Hall element. [Perspective 7] The rotation angle detection device according to any one of Perspectives 1 to 5, wherein the detection element is a magnetoresistive element. [Perspective 8] The rotation angle detection device according to any one of Perspectives 1 to 7, wherein the object to be detected is the brake pedal (25) of a vehicle (10). [Perspective 9] The rotation angle detection device according to Perspective 8, wherein the signal output from the detection element is used to activate a control device (80) that controls the braking of the vehicle.[Perspective 10] The rotation angle detection device according to Perspective 9, wherein the value of the signal output from the detection element changes immediately after the brake pedal is operated.

Claims

1. A rotation angle detection device comprising: a rotating member (34) that rotates together with a detection target (25) about a rotation axis (CL); a magnet (44) that rotates together with the rotating member; and a detection element (462) that outputs a signal corresponding to a change in the magnetic field due to the rotation of the magnet, wherein the magnet is positioned outside the rotation axis in the orthogonal direction (Do), which is perpendicular to the rotation axis.

2. The rotation angle detection device according to claim 1, wherein the magnet is a first magnet, the detection element is a first detection element, the rotation angle detection device comprises a second magnet (36) that rotates together with the rotating member and the first magnet, and a second detection element (402) that outputs a signal corresponding to the change in the magnetic field due to the rotation of the second magnet, which corresponds to the change in the magnetic field due to the rotation of the object to be detected, and when the first magnet is projected in the direction (Da) from which the rotation axis extends, the projected first magnet overlaps with the second magnet.

3. The rotation angle detection device according to claim 1 or 2, wherein the distance from the rotation axis in the orthogonal direction to the detection element is longer than the distance from the rotation axis in the orthogonal direction to the magnet.

4. The rotation angle detection device according to claim 1 or 2, wherein the direction of the magnetic field (Dsw) detected by the detection element is parallel to the magnetization direction of the magnet when the magnet rotates and comes closest to the detection element.

5. The rotation angle detection device according to claim 4, wherein the magnetization direction of the magnet is perpendicular to the direction (Da) in which the rotation axis extends.

6. The rotation angle detection device according to claim 1 or 2, wherein the detection element is a Hall element.

7. The rotation angle detection device according to claim 1 or 2, wherein the detection element is a magnetoresistive element.

8. The rotation angle detection device according to claim 1 or 2, wherein the object to be detected is the brake pedal (25) of the vehicle (10).

9. The rotation angle detection device according to claim 8, wherein the signal output from the detection element is used to activate a control device (80) that controls the braking of the vehicle.

10. The rotation angle detection device according to claim 9, wherein the value of the signal output from the detection element changes immediately after the brake pedal is operated.

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