Magnetostrictive torque angle sensor and magnetostrictive torque angle sensing system

Abstract

A magnetostrictive torque angle sensor (100) is provided with a shaft (10) having a magnetostrictive part (12) disposed around the shaft (10), and a magnetic pole part (101) formed in an arc shape and provided with a first magnetic pole segment (101A) and a second magnetic pole segment (101B) disposed so as to face the first magnetic pole segment (101A) at an interval in the axial direction. The first magnetic pole segment (101A) has a first protruding magnetic pole (110) protruding in the radial direction toward the shaft (10), the second magnetic pole segment (101B) has a second protruding magnetic pole (120) protruding in the radial direction toward the shaft (10) at a position different from the first protruding magnetic pole (110) in the circumferential direction, an excitation coil (130) and an angle detection coil (150) are wound around the first protruding magnetic pole (110), and a torque detection coil (140) is wound around the second protruding magnetic pole (120). The magnetic resistance between the magnetostrictive portion (12) and the first protruding magnetic pole (110) is configured to periodically vary with rotation of the shaft (10).

Description

Technical Field

[0001] This invention relates to a magnetostrictive torque-angle sensor and a magnetostrictive torque-angle sensing system, and particularly to a magnetostrictive torque-angle sensor and a magnetostrictive torque-angle sensing system capable of detecting torque and angle using the same sensor. Background Technology

[0002] A magnetostrictive torque sensor is known, in which a magnetostrictive film with magnetostrictive properties is pre-placed on the surface of a shaft, and the torque caused by rotation acting on the shaft is detected by detecting the magnetostrictive properties of the magnetostrictive film. This magnetostrictive torque sensor has a magnetic circuit and windings arranged around the shaft at a direction of +45° or -45° relative to the shaft center.

[0003] When a torque is applied to a shaft equipped with a magnetostrictive diaphragm, strain will be generated in the diaphragm on the shaft surface, and the permeability of the diaphragm will change due to the Villari effect. The impedance of the windings of the magnetostrictive torque sensor will change accordingly with the change in the permeability of the magnetostrictive diaphragm. As a result, the magnetostrictive torque sensor can obtain a detection signal corresponding to the torque applied to the shaft based on the impedance change corresponding to the torque applied to the shaft.

[0004] In cases where not only the torque applied to the shaft is detected, but also the angle of the shaft, an angle sensor is required on the same shaft in addition to the torque sensor. Such a magnetostrictive torque-angle sensor is described in Patent Document 1.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2008-76066 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In the case of the torque and angle sensors described in Patent Document 1, two sensors need to be physically installed. This results in a larger overall sensor size and incurs the cost of two sensors. Furthermore, the probability of failure may increase with the increase in the number of components. Therefore, ideally, instead of physically installing two sensors, a single sensor can be used to detect torque and angle by sharing the stator.

[0010] Conventional magnetostrictive sensors are constructed by arranging annular magnetic poles around a shaft. Therefore, it is difficult to easily replace the magnetic poles while the shaft remains in place.

[0011] The present invention was made to solve the problems mentioned above, and its object is to provide a magnetostrictive torque-angle sensor and a magnetostrictive torque-angle sensing system that can detect torque and angle using the same sensor and whose magnetic poles can be easily replaced.

[0012] Solution for solving the problem

[0013] The magnetostrictive torque angle sensor of the present invention has a shaft and a magnetic pole portion. The shaft has a magnetostrictive portion, and the magnetic pole portion is disposed around the shaft. In the magnetostrictive torque angle sensor, the magnetic pole portion is formed in an arc shape and has a first magnetic pole segment and a second magnetic pole segment disposed opposite to the first magnetic pole segment at an axial distance. The first magnetic pole segment has a first protruding magnetic pole that protrudes radially toward the shaft. The second magnetic pole segment has a second protruding magnetic pole that protrudes radially toward the shaft at a position different from the first protruding magnetic pole in the circumferential direction. An excitation coil and an angle detection coil are wound around the first protruding magnetic pole, and a torque detection coil is wound around the second protruding magnetic pole. The magnetic resistance between the magnetostrictive portion and the first protruding magnetic pole is configured to change periodically with the rotation of the shaft.

[0014] In the magnetostrictive torque angle sensor of the present invention, the magnetoresistive force is configured to vary periodically in the circumferential direction by means of the radius distance from the central axis of the shaft to the magnetostrictive part, or by means of the size of the magnetostrictive part in the direction along the axis of the circumference periodically.

[0015] In the magnetostrictive torque angle sensor of the present invention, the mechanical center angle of the arc in the magnetic pole section is set to an electrical angle of 360°. The excitation coil is arranged in the first magnetic pole section to form the first protruding magnetic pole at four locations with electrical angles of 90° intervals. The angle detection coil is arranged in the first magnetic pole section to form the first protruding magnetic pole at four locations with electrical angles of 90° intervals. The torque detection coil is arranged in the second magnetic pole section to form the second protruding magnetic pole at two locations with electrical angles of 180°.

[0016] In the magnetostrictive torque angle sensor of the present invention, the mechanical center angle of the arc in the magnetic pole section is set to an electrical angle of 360°, the excitation coil is disposed at least at one location of the first protruding magnetic pole, the angle detection coil is disposed at least at two locations of the first protruding magnetic pole in the first magnetic pole section, and the torque detection coil is disposed at two locations of the second protruding magnetic pole in the second magnetic pole section, forming an electrical angle of 180°.

[0017] In the magnetostrictive torque angle sensor of the present invention, the mechanical center angle of the arc in the magnetic pole section is set to an electrical angle of 360°, the excitation coil is arranged at least in the first magnetic pole section to form two first protruding magnetic poles with an electrical angle of 180°, the angle detection coil is arranged at least in the first magnetic pole section to form two first protruding magnetic poles, and the torque detection coil is arranged in the second protruding magnetic pole in one part of the second magnetic pole section.

[0018] The magnetostrictive torque-angle sensing system of the present invention includes: the aforementioned magnetostrictive torque-angle sensor, wherein a torque detection coil is disposed at two locations within a second magnetic pole segment; and a processing unit that processes a torque detection signal from the torque detection coil and an angle detection signal from the angle detection coil, the processing unit being configured to: supply an excitation signal to an excitation coil; detect the torque applied to the shaft using the torque detection signal from the torque detection coil; and detect the angle of the shaft using the angle detection signal from the angle detection coil.

[0019] The magnetostrictive torque-angle sensing system of the present invention includes: the aforementioned magnetostrictive torque-angle sensor, wherein a torque detection coil is disposed at any location within a second magnetic pole segment; and a processing unit that processes a torque detection signal from the torque detection coil and an angle detection signal from the angle detection coil, the processing unit being configured to: supply an excitation signal to an excitation coil; detect the angle of the shaft using the angle detection signal from the angle detection coil; and correct the torque detection signal from the torque detection coil using the angle detection signal from the angle detection coil, thereby detecting the torque applied to the shaft.

[0020] The magnetostrictive torque angle sensor of the present invention has a shaft and a magnetic pole portion. The shaft has a magnetostrictive portion, and the magnetic pole portion is disposed around the shaft. In the magnetostrictive torque angle sensor, the magnetic pole portion is formed in an arc shape and has a first magnetic pole segment and a second magnetic pole segment disposed opposite to the first magnetic pole segment at axial intervals. The first magnetic pole segment has a plurality of first protruding magnetic poles that protrude radially toward the shaft. An excitation coil and an angle detection coil are each wound around at least four of the plurality of first protruding magnetic poles. The at least four-pole excitation coil is configured by alternating first excitation coils and second excitation coils. First excitation signals and second excitation signals with different phases are supplied to the first excitation coils and the second excitation coils, respectively. The second magnetic pole segment has a second protruding magnetic pole that protrudes radially toward the shaft at a position different from the first protruding magnetic poles in the circumferential direction. At least one pole of the torque detection coil is wound around the second protruding magnetic pole. The magnetic resistance between the magnetostrictive portion and the first protruding magnetic pole is configured to change periodically with the rotation of the shaft.

[0021] In the magnetostrictive torque angle sensor of the present invention, the magnetoresistive force is configured to vary periodically in the circumferential direction by means of the radius distance from the central axis of the shaft to the magnetostrictive part, or by means of the size of the magnetostrictive part in the direction along the axis of the circumference periodically.

[0022] In the magnetostrictive torque angle sensor of the present invention, when n is set to an integer greater than or equal to 2, in the first magnetic pole segment, the excitation coil and the angle detection coil are each wound around the first protruding magnetic pole of the 2n pole, and the excitation coil of the 2n pole is formed by the first excitation coil of the n pole and the second excitation coil of the n pole being arranged alternately in the circumferential direction.

[0023] In the magnetostrictive torque angle sensor of the present invention, a first excitation signal is supplied to a first excitation coil, and a second excitation signal with a phase that differs from the first excitation signal by a fixed angle is supplied to a second excitation coil.

[0024] In the magnetostrictive torque angle sensor of the present invention, the torque detection coil is disposed in the second magnetic pole segment located in the middle of the first protruding magnetic poles of two adjacent poles in the circumferential direction.

[0025] The magnetostrictive torque-angle sensing system of the present invention includes: the magnetostrictive torque-angle sensor described above; and a processing unit that processes a torque detection signal from a torque detection coil and an angle detection signal from an angle detection coil. The processing unit is configured to: supply a first excitation signal and a second excitation signal with different phases to a first excitation coil and a second excitation coil, respectively; detect the torque applied to the shaft using the torque detection signal from the torque detection coil; and detect the angle of the shaft using the angle detection signal from the angle detection coil.

[0026] In the magnetostrictive torque angle sensing system of the present invention, the processing unit corrects the torque detection signal by means of the angle detection signal, thereby detecting the torque.

[0027] Invention Effects

[0028] In the magnetostrictive torque-angle sensor of the present invention, since an arc-shaped magnetic pole portion is arranged around the shaft, a torque detection signal is obtained from the torque detection coil and an angle detection signal is obtained from the angle detection coil. Therefore, a magnetostrictive torque-angle sensor and a magnetostrictive torque-angle sensing system that can detect torque and angle with the same sensor and whose magnetic pole portions can be easily replaced can be provided. Attached Figure Description

[0029] Figure 1 This is a perspective view showing the configuration of the magnetostrictive torque angle sensor according to Embodiment 1.

[0030] Figure 2 It means Figure 1 A sectional view of the section at line II-II.

[0031] Figure 3 It means Figure 1 A sectional view of the section at line III-III.

[0032] Figure 4 This is an explanatory diagram showing the configuration of the first and second protruding magnetic poles of the magnetostrictive torque angle sensor of Embodiment 1 in a unfolded state on a plane.

[0033] Figure 5 This is a configuration diagram showing the structure of the shaft of the magnetostrictive torque angle sensor according to Embodiment 1.

[0034] Figure 6 This is a configuration diagram showing the structure of the shaft of the magnetostrictive torque angle sensor according to Embodiment 1.

[0035] Figure 7 This is a configuration diagram showing the structure of the shaft of the magnetostrictive torque angle sensor according to Embodiment 1.

[0036] Figure 8 This is a configuration diagram showing the structure of the shaft of the magnetostrictive torque angle sensor according to Embodiment 1.

[0037] Figure 9 This is a configuration diagram showing the structure of the shaft of the magnetostrictive torque angle sensor according to Embodiment 1.

[0038] Figure 10 This is a configuration diagram showing the structure of the shaft of the magnetostrictive torque angle sensor according to Embodiment 1.

[0039] Figure 11 This is a characteristic diagram showing the magnetoresistive characteristics of the magnetostrictive torque angle sensor according to Embodiment 1.

[0040] Figure 12 This is a configuration diagram showing the structure of the magnetostrictive torque angle sensing system of Embodiment 1.

[0041] Figure 13 This is a characteristic diagram showing the output voltage characteristics obtained by processing the voltage generated in the torque detection coil when the shaft rotates in the magnetostrictive torque angle sensor of Embodiment 1.

[0042] Figure 14 This is a characteristic diagram showing the output voltage characteristics obtained by processing the voltage generated in the angle detection coil when the shaft rotates in the magnetostrictive torque angle sensor of Embodiment 1.

[0043] Figure 15This is a characteristic diagram showing the output voltage characteristics obtained by processing the voltage generated in the torque detection coil when torque is input in the magnetostrictive torque angle sensor of Embodiment 1.

[0044] Figure 16 This is a characteristic diagram showing the output voltage characteristics obtained by processing the voltage generated in the angle detection coil when torque is input in the magnetostrictive torque angle sensor of Embodiment 1.

[0045] Figure 17 This is a perspective view showing the configuration of the magnetostrictive torque angle sensor of Embodiment 2.

[0046] Figure 18 It means Figure 17 A sectional view of the section at line XVIII-XVIII.

[0047] Figure 19 It means Figure 17 A cross-sectional view of the section at the XIX-XIX line.

[0048] Figure 20 This is an explanatory diagram showing the configuration of the first and second protruding magnetic poles of the magnetostrictive torque angle sensor of Embodiment 2 in a planar unfolded state.

[0049] Figure 21 This is a characteristic graph showing the voltage characteristics obtained by processing the torque detection signal when the shaft rotates in the magnetostrictive torque angle sensing system of Embodiment 2.

[0050] Figure 22 This is a characteristic graph showing the voltage characteristics obtained by processing the angle detection signal when the shaft rotates in the magnetostrictive torque angle sensing system of Embodiment 2.

[0051] Figure 23 This is a characteristic graph showing the voltage characteristics obtained by processing the torque detection signal when torque is input in the magnetostrictive torque angle sensing system of Embodiment 2.

[0052] Figure 24 This is a characteristic graph showing the voltage characteristics obtained by processing the angle detection signal when torque is input in the magnetostrictive torque angle sensing system of Embodiment 2. Detailed Implementation

[0053] Hereinafter, embodiments of the magnetostrictive torque angle sensor 100 and the magnetostrictive torque angle sensing system 1 of the present invention will be described using the accompanying drawings. It should be noted that in each figure, the same reference numerals are used to label the same parts.

[0054] Implementation method 1.

[0055] First, use Figures 1-4 The basic configuration of the magnetostrictive torque angle sensor 100 of Embodiment 1 will be described. This Embodiment 1 is based on Japanese Invention Application No. 2023-125353.

[0056] [Composition of the magnetostrictive torque angle sensor 100]

[0057] Figure 1 This is a perspective view showing the configuration of the magnetostrictive torque angle sensor 100 according to Embodiment 1. Figure 2 It means Figure 1 A sectional view of the section at line II-II. Figure 3 It means Figure 1 A sectional view of the section at line III-III. Figure 4 This is an explanatory diagram showing the arrangement of the first protruding magnetic pole 110 and the second protruding magnetic pole 120 of the magnetostrictive torque angle sensor 100 of Embodiment 1 in a state unfolded on a plane.

[0058] The magnetostrictive torque angle sensor 100 mainly includes a shaft 10 and a magnetic pole portion 101. The shaft 10 has a magnetostrictive portion 12 on its outer peripheral surface. The shaft 10 is held by a bearing (not shown) or the like and is configured to rotate relative to the magnetic pole portion 101. The shaft 10 rotates together with a test object (not shown) or is subjected to torque.

[0059] The magnetic pole section 101 is formed in an arc shape and is disposed around the shaft 10. The magnetic pole section 101 includes a first magnetic pole segment 101A and a second magnetic pole segment 101B which is disposed opposite to the first magnetic pole segment 101A in the axial direction with a gap adjustment section 190.

[0060] An arc is a part of a circle. It should be noted that if the outer or inner circumference of the magnetic pole portion 101 is not a part of a smooth circle, but is a part of a polygon such as “7”, ">”, “V”, “L”, “]” or “]”, or if the end of the arc is extended as in “U” or “J”, it is also treated as an “arc” in this application specification.

[0061] The angle between the center of the circle forming the arc and the two ends of the arc is defined as the central angle of the arc. In Embodiment 1, in order to distinguish the central angle of the arc from the electrical angle described later, it is sometimes referred to as the mechanical central angle of the arc.

[0062] exist Figure 1In the specific example shown, the central angle of the arc in the magnetic pole section 101 is formed to be approximately 180°. Theoretically, the central angle of the arc is greater than 0° and less than 360°. In practice, ideally, the central angle of the arc should be a first central angle (e.g., around 30°) or greater, satisfying a first condition where the magnetostrictive torque angle sensor 100 can be equipped with the magnetic poles and coil described later, and ideally, a second central angle (e.g., around 225°) or less, satisfying a second condition where the magnetic pole section 101 can be easily assembled and disassembled relative to the shaft 10. Furthermore, ideally, the magnetic resistance of the shaft 10 changes periodically in accordance with the central angle of the arc.

[0063] The first magnetic pole section 101A is provided with a plurality of first protruding magnetic poles 110 that protrude radially toward the shaft 10. Figure 1 In the specific example shown, four first protruding magnetic poles 110a, 110b, 110c and 110d are provided at equal angular intervals as the first protruding magnetic pole 110.

[0064] In the second magnetic pole segment 101B, a second protruding magnetic pole 120 is provided at a position different in the circumferential direction from the first protruding magnetic pole 110, protruding radially toward the axis 10. Figure 1 In the specific example shown, two second protruding magnetic poles 120a and 120c are provided as the second protruding magnetic pole 120. It should be noted that, as the second protruding magnetic pole 120, a second protruding magnetic pole (not shown) may also be provided at the middle position between the second protruding magnetic poles 120a and 120c.

[0065] An excitation coil 130 and an angle detection coil 150 are wound around the first protruding magnetic pole 110. Figures 1-4 In the specific example shown, an excitation coil 130a and an angle detection coil 150a are wound around the first protruding magnetic pole 110a, an excitation coil 130b and an angle detection coil 150b are wound around the first protruding magnetic pole 110b, an excitation coil 130c and an angle detection coil 150c are wound around the first protruding magnetic pole 110c, and an excitation coil 130d and an angle detection coil 150d are wound around the first protruding magnetic pole 110d.

[0066] A torque detection coil 140 is wound around the second protruding magnetic pole 120. Figures 1-4 In the specific example shown, a torque detection coil 140a is wound around the second protruding magnetic pole 120a, and a torque detection coil 140c is wound around the second protruding magnetic pole 120c.

[0067] like Figure 4As shown, the mechanical center angle of the arc in the magnetic pole section 101 is treated as an electrical angle of 360°. It should be noted that the electrical angle is used for the configuration of the first protruding magnetic poles 110a to 110d and the second protruding magnetic poles 120a and 120c, the excitation signal, the angle detection signal, and the phase of the angle detection signal.

[0068] The first protruding magnetic poles 110a to 110d are arranged at electrical angle intervals of 90° within a range of 360° electrical angle. It should be noted that the angular interval between the first protruding magnetic poles 110a to 110d is not strictly limited to 90° and may include some variations and errors.

[0069] The second protruding magnetic pole 120a is configured to be located circumferentially between the first protruding magnetic poles 110a to 110b. The second protruding magnetic pole 120c is configured circumferentially between the first protruding magnetic poles 110c to 110d.

[0070] therefore, Figure 4 The horizontal magnetic circuit H shown is formed between the first protruding magnetic pole 110a, the magnetostrictive portion 12, and the first protruding magnetic pole 110b; between the first protruding magnetic pole 110b, the magnetostrictive portion 12, and the first protruding magnetic pole 110c; and between the first protruding magnetic pole 110c, the magnetostrictive portion 12, and the first protruding magnetic pole 110d.

[0071] Figure 4 The first inclined magnetic circuit Diag_1, which is about 45° as shown, is formed between the second protruding magnetic pole 120a, the magnetostrictive portion 12, and the first protruding magnetic pole 110a, and between the second protruding magnetic pole 120c, the magnetostrictive portion 12, and the first protruding magnetic pole 110c.

[0072] Figure 4 The second inclined magnetic circuit Diag_2, which is approximately -45°, is formed between the second protruding magnetic pole 120a, the magnetostrictive portion 12, and the first protruding magnetic pole 110b, and between the second protruding magnetic pole 120c, the magnetostrictive portion 12, and the first protruding magnetic pole 110d.

[0073] Regarding the excitation coil 130, a specific example of four poles of the excitation coils 130a to 130d is illustrated. It should be noted that the excitation coil 130 may be configured at least in two poles with an electrical angle of 180° within the first magnetic pole segment 101A, or at least in any one location within the first magnetic pole segment 101A.

[0074] Regarding the angle detection coil 150, the illustration shows a specific example of a four-pole angle detection coil 150a-150d, which is composed of angle detection coils 150a and 150b of the first angle detection phase, and angle detection coils 150c and 150d of the second angle detection phase. It should be noted that the angle detection coil 150 can also be composed of one of the angle detection coils 150a and 150b of the first angle detection phase, and one of the angle detection coils 150c and 150d of the second angle detection phase.

[0075] Regarding the torque detection coil 140, the illustration shows two specific examples of two locations within the second magnetic pole section 101B of the torque detection coil 140a and the torque detection coil 140c that are at an electrical angle of 180° to each other, but it is acceptable for the coil to be positioned at any one location within the second magnetic pole section 101B.

[0076] [Characteristics of magnetoresistance]

[0077] Next, refer to Figures 5-11 The structure of shaft 10 and the characteristics of its magnetic reluctance are explained. Figures 5-10 This is a configuration diagram showing the structure of the shaft 10 of the magnetostrictive torque angle sensor 100 in Embodiment 1. Figure 11 This is a characteristic diagram showing the magnetoresistive characteristics of the magnetostrictive torque angle sensor 100 of Embodiment 1.

[0078] exist Figure 5 In this configuration, the shaft 10 includes an inner shaft portion 11 and a magnetostrictive portion 12 disposed on the outer periphery of the inner shaft portion 11, and is configured such that the radius of the shaft 10 changes periodically in the circumferential direction. Thus, as... Figure 11 As shown, the first magnetic resistance between the magnetostrictive portion 12 and the first protruding magnetic poles 110a to 110d, and the second magnetic resistance between the magnetostrictive portion 12 and the second protruding magnetic poles 120a and 120c, are configured to change periodically with the rotation of the shaft 10.

[0079] It should be noted that, ideally, the first magnetoresistive field, required for angle detection, changes periodically with the rotation of shaft 10. Therefore, as... Figure 6 As shown, as long as the magnetostrictive region 12a on the shaft 10, which is opposite to the first protruding magnetic poles 110a to 110d, has such Figure 5 Such a cross-sectional shape is acceptable. The magnetostrictive region 12b on the shaft 10, which is opposite to the second protruding magnetic poles 120a to 120c, can also be a circular cross-sectional shape.

[0080] Here, axis 10 is formed as shown in any of the following examples. Figure 5The outer peripheral surface of the inner shaft portion 11 is coated or thermally sprayed with a magnetostrictive portion 12, which serves as a magnetostrictive film, to form the shaft 10. Alternatively, the inner shaft portion 11 is pressed into... Figure 5 or Figure 6 The outer cylindrical portion 12 is shaped as a magnetostrictive part, thereby forming the shaft 10. Alternatively, both the inner shaft portion 11 and the magnetostrictive part 12 may be made entirely of a magnetostrictive material, and the shaft 10 may be entirely formed by the magnetostrictive part 12. It should be noted that the same manufacturing method can be applied to other forms of the shaft 10 shown below.

[0081] exist Figure 7 In this design, a magnetostrictive portion 12 is formed on a portion of the outer circumferential surface of the cylindrical inner shaft portion 11, at a position where the first protruding magnetic poles 110a-110d and the second protruding magnetic poles 120a-120c are opposite to the shaft 10, by applying a coating or thermal spraying. Alternatively, the shaft 10 is formed by pressing the inner shaft portion 11 into the magnetostrictive portion 12, which serves as the outer cylinder portion. Here, the magnetostrictive portion 12 is formed such that its axial size periodically varies in the circumferential direction. Thus, as... Figure 11 As shown, the first magnetic resistance between the magnetostrictive part 12 and the first protruding magnetic poles 110a to 110d, and the second magnetic resistance between the magnetostrictive part 12 and the second protruding magnetic poles 120a to 120c, change periodically with the rotation of the shaft 10.

[0082] It should be noted that, in Figure 7 In the middle, the cross-section of the inner shaft portion 11 is not limited to a perfect circle, but can also be as follows: Figure 5 That is configured so that the radius changes periodically in the circumferential direction.

[0083] exist Figure 8 In this design, a magnetostrictive portion 12, formed on a portion of the outer peripheral surface of the inner shaft portion 11 by coating or thermal spraying, has a magnetostrictive region 12a and a magnetostrictive region 12b. Here, the magnetostrictive region 12a is the region opposite to the first protruding magnetic poles 110a to 110d. The magnetostrictive region 12b is the region opposite to the second protruding magnetic poles 120a to 120c. The magnetostrictive region 12a is formed such that its axial size changes periodically in the circumferential direction. On the other hand, the magnetostrictive region 12b is formed such that its axial size does not change. Thus, as... Figure 11 As shown, the first magnetic reluctance between the magnetostrictive region 12a and the first protruding magnetic poles 110a-110d changes periodically with the rotation of the shaft 10. On the other hand, the second magnetic reluctance between the magnetostrictive region 12b and the second protruding magnetic poles 120a-120c does not change with the rotation of the shaft 10, but remains constant.

[0084] It should be noted that, in Figure 8In the middle, the cross-section of the inner shaft portion 11 is not limited to a perfect circle, but can also be as follows: Figure 5 That is configured so that the radius changes periodically in the circumferential direction.

[0085] exist Figure 9 In the inner shaft portion 11, a magnetostrictive portion 12 is formed by applying a coating or thermal spraying process at a position where the first protruding magnetic poles 110a-110d and the second protruding magnetic poles 120a-120c are opposite to the shaft 10, with the axial size periodically varying in the circumferential direction and protruding from the inner shaft portion 11. Thus, as... Figure 11 As shown, the first magnetic resistance between the magnetostrictive part 12 and the first protruding magnetic poles 110a to 110d, and the second magnetic resistance between the magnetostrictive part 12 and the second protruding magnetic poles 120a to 120c, change periodically with the rotation of the shaft 10.

[0086] It should be noted that, in Figure 9 In the middle, the cross-section of the inner shaft portion 11 is not limited to a perfect circle, but can also be as follows: Figure 5 That is configured so that the radius changes periodically in the circumferential direction.

[0087] exist Figure 10 In this design, a magnetostrictive portion 12, formed on a portion of the outer peripheral surface of the inner shaft portion 11 by means of coating or thermal spraying, protruding from the inner shaft portion 11, has a magnetostrictive region 12a and a magnetostrictive region 12b. Here, the magnetostrictive region 12a is opposite to the first protruding magnetic poles 110a-110d and is formed such that its axial size changes periodically in the circumferential direction. The magnetostrictive region 12b is opposite to the second protruding magnetic poles 120a-120c and is formed such that its axial size does not change. Thus, as... Figure 11 As shown, the first magnetic reluctance between the magnetostrictive region 12a and the first protruding magnetic poles 110a-110d changes periodically with the rotation of the shaft 10. On the other hand, the second magnetic reluctance between the magnetostrictive region 12b and the second protruding magnetic poles 120a-120c does not change with the rotation of the shaft 10, but remains constant.

[0088] It should be noted that, in Figure 10 In the middle, the cross-section of the inner shaft portion 11 is not limited to a perfect circle, but can also be as follows: Figure 5 That is configured so that the radius changes periodically in the circumferential direction.

[0089] about Figure 5 and Figure 6 The cross-sectional shape of shaft 10 shown and Figures 7-10 The shape of the magnetostrictive part 12 shown and Figure 11The magnetoresistance change rate shown illustrates the shape along a smooth sine wave, but is not limited to it. For example, instead of a sine wave, various periodic shapes such as triangular waves, rectangular waves, and multi-segment stepped waves can be used to determine the cross-sectional shape of shaft 10. Figures 6-7 The shape of the magnetostrictive part 12 shown and Figure 11 The rate of change of magnetic reluctance is shown.

[0090] [Processing of the magnetostrictive torque angle sensing system 1]

[0091] The following is for reference Figure 12 The magnetostrictive torque angle sensing system 1 will be described. Figure 12 This is a configuration diagram showing the structure of the magnetostrictive torque angle sensing system 1 according to Embodiment 1. The magnetostrictive torque angle sensing system 1 includes a magnetostrictive torque angle sensor 100 and a processing unit 200. Here, in relation to the processing unit 200, the magnetostrictive torque angle sensor 100 shows an excitation coil 130, a torque detection coil 140, and an angle detection coil 150.

[0092] The processing unit 200 supplies an excitation signal to the excitation coil 130. The processing unit 200 receives a torque detection signal from the torque detection coil 140, detects the torque applied to the shaft 10 based on the voltage change of the torque detection signal, and outputs torque data. The processing unit 200 receives multiple angle detection signals from the angle detection coil 150, detects the angle of the shaft 10, and outputs angle data.

[0093] The following is for reference Figures 13-16 The angle detection signal and torque detection signal during the rotation and torque input of shaft 10 are described in detail.

[0094] • Torque detection when shaft 10 rotates without torque input:

[0095] Figure 13 This is a characteristic graph showing the characteristics of the voltages generated in the torque detection coil 140a and torque detection coil 140c when the shaft 10 rotates without any torque input to the shaft 10 in the magnetostrictive torque angle sensor 100 of Embodiment 1. Figure 13 The figure shows the torque detection signals generated in torque detection coils 140a and 140c when shaft 10 rotates without torque input.

[0096] The phase difference between the torque detection signals generated in torque detection coils 140a and 140c is 180°, resulting in a voltage change of one cycle over an electrical angle of 360°. Therefore, the composite torque detection signal obtained by combining the torque detection signals generated in torque detection coils 140a and 140c becomes a flat state without voltage change. Consequently, the processing unit 200 outputs torque data indicating torque = 0. That is, even when the shaft 10 rotates, it does not affect torque detection.

[0097] It should be noted that when only one torque detection coil is used, it is impossible to obtain the desired torque during rotation without torque. Figure 13 Such a flat characteristic. In this case, by correcting the torque detection signal using the angle detection signal, a result such as... Figure 13 Such a flat characteristic can be addressed without adversely affecting torque sensing.

[0098] In addition, Figure 13 The torque detection signal is represented as a sinusoidal wave, but it is not limited to this. When the waveform of the excitation signal supplied from the processing unit 200 to the excitation coil 130 and the reluctance change rate of the shaft 10 are various periodic shapes such as triangular wave, rectangular wave, and multi-segment stepped wave, the torque detection signal also becomes a waveform of the same shape.

[0099] • Angle detection when shaft 10 rotates without torque input:

[0100] Figure 14 This is a characteristic diagram showing the characteristics of the voltage generated in the angle detection coils 150a to 150d when the shaft 10 rotates without any torque input to the shaft 10 in the magnetostrictive torque angle sensor 100 of Embodiment 1. Figure 14 The diagram shows the angle detection signals generated in the angle detection coils 150a to 150d when the shaft 10 rotates without torque input.

[0101] The angle detection signal (hereinafter, "first angle detection signal") generated in the angle detection coils 150a and 150b, which serve as the first angle detection phase, produces a voltage change of one cycle over an electrical angle of 360°. The angle detection signal (hereinafter, "second angle detection signal") generated in the angle detection coils 150c and 150d, which serve as the second angle detection phase, has a phase difference of 90° from the first angle detection signal and produces a voltage change of one cycle over an electrical angle of 360°.

[0102] Therefore, the processing unit 200 calculates the angle of rotation of the shaft 10 by comparing the amplitude values ​​of the first angle detection signals from angle detection coils 150a and 150b with the amplitude values ​​of the second angle detection signals from angle detection coils 150c and 150d, and outputs this as angle data. It should be noted that... Figure 14 The angle detection signal is represented as a sinusoidal wave, but it is not limited to this. When the waveform of the excitation signal supplied from the processing unit 200 to the excitation coil 130 and the reluctance change rate of the shaft 10 are various periodic shapes such as triangular wave, rectangular wave, and multi-segment stepped wave, the angle detection signal also becomes a waveform of the same shape.

[0103] • Torque detection when there is no rotation of shaft 10 during torque input:

[0104] Figure 15 This is a characteristic diagram showing the characteristics of the voltages generated in the torque detection coil 140a and torque detection coil 140c in the magnetostrictive torque angle sensor 100 of Embodiment 1 when there is a torque input to the shaft 10 without rotation. Figure 15 The diagram shows the torque detection signals generated in torque detection coils 140a and 140c when torque is input without rotation of shaft 10. When focusing on the torque input... Figure 4 When the torque detection signals obtained by the first inclined magnetic circuit Diag_1 and the second inclined magnetic circuit Diag_2 are obtained respectively, the first torque detection signal obtained by the first inclined magnetic circuit Diag_1 and the second torque detection signal obtained by the second inclined magnetic circuit Diag_2 have different voltage change rates.

[0105] Based on the difference between the first torque detection signal obtained from the first inclined magnetic circuit Diag_1 and the second torque detection signal obtained from the second inclined magnetic circuit Diag_2, a synthetic torque detection signal with a voltage change rate linearly corresponding to the torque is obtained. Therefore, the processing unit 200 calculates the input torque to the shaft 10 based on the synthetic torque detection signal and outputs it as torque data.

[0106] • Angle detection during torque input without rotation of shaft 10:

[0107] Figure 16 This is a characteristic diagram showing the characteristics of the voltage generated in the angle detection coils 150a to 150d when there is a torque input to the shaft 10 without rotation in the magnetostrictive torque angle sensor 100 of Embodiment 1. Figure 16 The diagram shows the angle detection signals generated in the angle detection coils 150a to 150d when torque is input without rotation of shaft 10.

[0108] Here, the first angle detection signal generated in angle detection coils 150a and 150b and the second angle detection signal generated in angle detection coils 150c and 150d have the same characteristics with respect to torque. Therefore, the synthesized angle detection signal synthesized by calculating the difference between the first and second angle detection signals becomes a flat state without voltage change. As a result, the processing unit 200 outputs angle data indicating angle = 0. That is, even when there is torque input on the shaft 10, it will not affect the angle detection.

[0109] The above Figures 13-16 The characteristics of shaft 10 rotation without torque input to shaft 10, and torque input to shaft 10 without rotation of shaft 10, have been described. In reality, it is possible for torque to be input to shaft 10 while shaft 10 is rotating. In such cases, the processing unit 200 utilizes parallel processing... Figures 13-16 The process described is used to calculate both the angle and the torque.

[0110] [Change of extreme numbers]

[0111] In Embodiment 1 above, excitation coils 130a to 130d are wound around all the first protruding magnetic poles 110a to 110d in the first magnetic pole segment 101A, but the magnetostrictive torque angle sensor 100 is not limited to this state. That is, the excitation coil 130 can be disposed at least in the first magnetic pole segment 101A as two poles with an electrical angle of 180°, or at least in any one part of the first magnetic pole segment 101A.

[0112] In Embodiment 1 above, angle detection coils 150a to 150d are wound around all the first protruding magnetic poles 110a to 110d of the first magnetic pole segment 101A, but the magnetostrictive torque angle sensor 100 is not limited to this state. That is, the angle detection coil 150 may also be composed of at least one of the angle detection coils 150a and 150b of the first angle detection phase and one of the angle detection coils 150c and 150d of the second angle detection phase.

[0113] In Embodiment 1 above, torque detection coils 140a and 140c are wound around the second protruding magnetic poles 120a and 120c of the second magnetic pole segment 101B, but the magnetostrictive torque angle sensor 100 is not limited to this state. That is, the torque detection coil 140 can be disposed at least at any one location within the second magnetic pole segment 101B.

[0114] It should be noted that, by reducing the excitation coil 130, torque detection coil 140, and angle detection coil 150, the first protruding magnetic pole 110, which does not contain the excitation coil 130 and angle detection coil 150, may not be provided in the first magnetic pole section 101A. Similarly, the second protruding magnetic pole 120, which does not contain the torque detection coil 140, may not be provided in the second magnetic pole section 101B.

[0115] [Effects obtained from Implementation Method 1]

[0116] The following describes Implementation Method 1 and its effects.

[0117] (1-1):

[0118] The magnetostrictive torque angle sensor 100 described in Embodiment 1 has a shaft 10 and a magnetic pole portion 101. The shaft 10 has a magnetostrictive portion 12, and the magnetic pole portion 101 is disposed around the shaft 10. In the magnetostrictive torque angle sensor 100, the magnetic pole portion 101 is formed in an arc shape and has a first magnetic pole segment 101A and a second magnetic pole segment 101B that is axially spaced apart from the first magnetic pole segment 101A. The first magnetic pole segment 101A has a radial direction toward the shaft 10. The first protruding magnetic pole 110 protrudes upward, and the second magnetic pole segment 101B has a second protruding magnetic pole 120 protruding radially toward the shaft 10 at a different position in the circumferential direction from the first protruding magnetic pole 110. An excitation coil 130 and an angle detection coil 150 are wound around the first protruding magnetic pole 110, and a torque detection coil 140 is wound around the second protruding magnetic pole 120. The magnetic resistance between the magnetostrictive part 12 and the first protruding magnetic pole 110 is configured to change periodically with the rotation of the shaft 10.

[0119] In this magnetostrictive torque-angle sensor 100, a torque detection signal can be obtained from the torque detection coil 140 and an angle detection signal can be obtained from the angle detection coil 150 within the same sensor. Furthermore, by arranging an arc-shaped magnetic pole portion 101 around the shaft 10, the replacement of the magnetic pole portion 101 becomes easy.

[0120] (1-2):

[0121] In the magnetostrictive torque-angle sensor 100 described in (1-1) above, the magnetoresistive force is configured to vary periodically in the circumferential direction by the radial distance from the central axis of the shaft 10 to the magnetostrictive portion 12, or by the periodic variation in the circumferential direction of the size of the magnetostrictive portion 12 along the axis. Therefore, using the same shaft 10 and magnetic pole portion 101, not only torque but also angle can be detected.

[0122] (1-3):

[0123] In the magnetostrictive torque-angle sensor 100 described in (1-1) to (1-2) above, the mechanical center angle of the arc in the magnetic pole section 101 is set to an electrical angle of 360°. The excitation coil 130 is arranged in the first magnetic pole section 101A at four locations with electrical angle intervals of 90°, forming the first protruding magnetic pole 110. The angle detection coil 150 is arranged in the first magnetic pole section 101A at four locations with electrical angle intervals of 90°, forming the first protruding magnetic pole 110. The torque detection coil 140 is arranged in the second magnetic pole section 101B at two locations with electrical angle intervals of 180°, forming the second protruding magnetic pole 120. As a result, angle and torque can be detected in a non-interfering manner using a single sensor, and the replacement of the magnetic pole section 101 relative to the shaft 10 becomes easy.

[0124] (1-4):

[0125] In the magnetostrictive torque-angle sensor 100 described in (1-1) to (1-3) above, the mechanical center angle of the arc in the magnetic pole section 101 is set to an electrical angle of 360°. The excitation coil 130 is disposed at least at one location of the first protruding magnetic pole 110, the angle detection coil 150 is disposed at least at two locations of the first protruding magnetic pole 110 within the first magnetic pole section 101A, and the torque detection coil 140 is disposed at two locations of the second protruding magnetic pole 120 within the second magnetic pole section 101B, forming an electrical angle of 180°. Therefore, angle and torque can be detected in a non-interfering manner using a single sensor, and the interchangeability of the magnetic pole section 101 relative to the shaft 10 becomes easy.

[0126] (1-5):

[0127] In the magnetostrictive torque angle sensor 100 described in (1-1) to (1-3) above, the mechanical center angle of the arc in the magnetic pole section 101 is set to an electrical angle of 360°. The excitation coil 130 is disposed at least at two locations within the first magnetic pole section 101A, forming two first protruding magnetic poles 110 with an electrical angle of 180°. The angle detection coil 150 is disposed at least at two locations within the first magnetic pole section 101A, forming two first protruding magnetic poles 110. The torque detection coil 140 is disposed at one location within the second magnetic pole section 101B, forming a second protruding magnetic pole 120. Here, the angle detection signal from the angle detection coil 150 is used to correct the torque detection signal from the torque detection coil 140, thereby detecting the torque applied to the shaft 10. Thus, even with a minimally configured single sensor, angle and torque can be detected in a non-interfering manner without any adverse effects on torque detection, and the replacement of the magnetic pole section 101 relative to the shaft 10 becomes easy.

[0128] (1-6):

[0129] The magnetostrictive torque-angle sensing system 1 described in Embodiment 1 includes: a magnetostrictive torque-angle sensor 100 as described in any of (1-1) to (1-4) above; and a processing unit 200 that processes the torque detection signal from the torque detection coil 140 and the angle detection signal from the angle detection coil 150. The processing unit 200 supplies an excitation signal to the excitation coil 130, detects the torque applied to the shaft 10 using the torque detection signal from the torque detection coil 140, and detects the angle of the shaft 10 using the angle detection signal from the angle detection coil 150. In this magnetostrictive torque-angle sensing system 1, the same sensor can obtain both the torque detection signal from the torque detection coil 140 and the angle detection signal from the angle detection coil 150. Furthermore, by arranging the arc-shaped magnetic pole portion 101 around the shaft 10, the replacement of the magnetic pole portion 101 becomes easy.

[0130] (1-7):

[0131] The magnetostrictive torque-angle sensing system 1 described in Embodiment 1 includes: a magnetostrictive torque-angle sensor 100 as described in (1-5) above; and a processing unit 200 that processes the torque detection signal from the torque detection coil 140 and the angle detection signal from the angle detection coil 150. The processing unit 200 supplies an excitation signal to the excitation coil 130, detects the angle of the shaft 10 using the angle detection signal from the angle detection coil 150, and corrects the torque detection signal from the torque detection coil 140 using the angle detection signal from the angle detection coil 150, thereby detecting the torque applied to the shaft 10. In this magnetostrictive torque-angle sensing system 1, the same sensor can obtain both the torque detection signal from the torque detection coil 140 and the angle detection signal from the angle detection coil 150. Furthermore, even with a minimally configured single sensor, angle and torque can be detected in a non-interfering manner without adversely affecting torque detection, and the replacement of the magnetic pole portion 101 relative to the shaft 10 becomes easy.

[0132] Implementation method 2.

[0133] First, use Figures 17-20 The basic configuration of the magnetostrictive torque angle sensor 100 in Embodiment 2 will be described. This Embodiment 2 is based on Japanese Invention Application No. 2023-125354.

[0134] [Composition of the magnetostrictive torque angle sensor 100]

[0135] Figure 17 This is a perspective view showing the configuration of the magnetostrictive torque angle sensor 100 according to Embodiment 2. Figure 18 It means Figure 17A sectional view of the section at line XVIII-XVIII. Figure 19 It means Figure 17 A cross-sectional view of the section at the XIX-XIX line. Figure 20 This is an explanatory diagram showing the configuration of the first protruding magnetic pole 110 and the second protruding magnetic pole 120 of the magnetostrictive torque angle sensor 100 of Embodiment 2 in a state unfolded on a plane.

[0136] The magnetostrictive torque angle sensor 100 mainly comprises a shaft 10 and a magnetic pole portion 101. The shaft 10 has a magnetostrictive portion 12 on its outer peripheral surface. The shaft 10 is held by a bearing (not shown) or the like and is configured to rotate relative to the magnetic pole portion 101. The shaft 10 rotates together with a test object (not shown) or is subjected to torque. The configuration of the shaft 10 and the characteristics of its magnetic resistance are described in detail below. Figures 5 to 11 As explained.

[0137] The magnetic pole portion 101 is formed in an arc shape and is disposed around the shaft 10. The magnetic pole portion 101 has a first magnetic pole segment 101A and a second magnetic pole segment 101B. The second magnetic pole segment 101B is disposed opposite to the first magnetic pole segment 101A in the axial direction with a spacing adjustment portion 190 between them.

[0138] An arc is a portion of a circle. The angle between the two ends of the arc and the center of the circle containing the arc is called the central angle of the arc. In embodiment 2, in order to distinguish the central angle of the arc from the electrical angle described later, it is sometimes referred to as the mechanical central angle of the arc.

[0139] It should be noted that if the outer or inner periphery of the magnetic pole portion 101 is not part of a smooth circle, but is part of a polygon such as “7”, ">”, “V”, “L”, “]” or “]”, or if the end of the arc is extended such as “U” or “J”, it is treated as an arc.

[0140] exist Figure 17 In the specific example shown, the central angle of the arc in the magnetic pole section 101 is formed to be approximately 180°. Theoretically, the central angle of the arc is greater than 0° and less than 360°.

[0141] In reality, the ideal central angle of the arc is a first central angle (e.g., around 30°) or higher, satisfying the first condition that the magnetostrictive torque angle sensor 100 can be equipped with the magnetic poles and coils described later. Ideally, it is also a second central angle (e.g., around 225°) or lower, satisfying the second condition that allows for easy assembly and disassembly of the magnetic pole portion 101 relative to the shaft 10. Furthermore, it is ideal that the magnetic resistance of the shaft 10 changes periodically in accordance with the central angle of the arc.

[0142] The first magnetic pole section 101A is provided with a plurality of first protruding magnetic poles 110 that protrude radially toward the shaft 10. Figure 17 In the specific example shown, four first protruding magnetic poles 110a, 110b, 110c and 110d are provided at equal angular intervals as a plurality of first protruding magnetic poles 110.

[0143] In the second magnetic pole segment 101B, at least one second protruding magnetic pole 120 is provided at a position different in the circumferential direction from the first protruding magnetic poles 110 (110a, 110b, 110c, and 110d), protruding radially toward the axis 10. Figure 17 In the specific example shown, a second protruding magnetic pole 120 is provided at a position corresponding to the midpoint between the first protruding magnetic poles 110b and 110c in the circumferential direction. It should be noted that the position of the second protruding magnetic pole 120 can also be at a position corresponding to the midpoint between the first protruding magnetic poles 110a and 110b in the circumferential direction, or at a position corresponding to the midpoint between the first protruding magnetic poles 110c and 110d in the circumferential direction. Furthermore, the second protruding magnetic pole 120 can be not only one pole, but also two or more poles.

[0144] At least four-pole excitation coils 130 and angle detection coils 150 are each wound around a plurality of first protruding magnetic poles 110.

[0145] exist Figures 17-20 In the specific example shown, as a plurality of first protruding magnetic poles 110, there are first protruding magnetic poles 110a, 110b, 110c and 110d. An excitation coil 130a and an angle detection coil 150a are wound around the first protruding magnetic pole 110a, an excitation coil 130b and an angle detection coil 150b are wound around the first protruding magnetic pole 110b, an excitation coil 130c and an angle detection coil 150c are wound around the first protruding magnetic pole 110d, and an excitation coil 130d and an angle detection coil 150d are wound around the first protruding magnetic pole 110d.

[0146] The excitation coil 130, with at least four poles, is constructed by alternating arrangements of a first excitation coil 131 and a second excitation coil 132. Figures 17-20 In the specific example shown, excitation coils 130a and 130c are the first excitation coil 131, and excitation coils 130b and 130d are the second excitation coil 132.

[0147] Here, a first excitation signal and a second excitation signal with different phases are supplied to the first excitation coil 131 and the second excitation coil 132, respectively. The first excitation signal and the second excitation signal are implemented, for example, by a sin-phase excitation signal and a cos-phase excitation signal with a phase difference of 90°. It should be noted that the sin-phase excitation signal and the cos-phase excitation signal are just examples, and can also represent various periodic waveforms such as triangular waves, rectangular waves, and multi-segment stepped waves, instead of sin waves and cos waves. The phase difference between the first excitation signal and the second excitation signal is not strictly limited to 90°.

[0148] like Figure 20 As shown, the mechanical center angle of the arc in the magnetic pole section 101 is treated as an electrical angle of 360°. It should be noted that the electrical angle is used for the configuration of the first protruding magnetic poles 110a to 110d and the second protruding magnetic pole 120, the configuration of the excitation coil 130, the configuration of the torque detection coil 140, the configuration of the angle detection coil 150, the excitation signal, the angle detection signal, and the phase of the angle detection signal.

[0149] exist Figure 20 In this configuration, the first protruding magnetic poles 110a to 110d are arranged at 90° intervals within a 360° electrical angle range. The second protruding magnetic pole 120 is positioned circumferentially between the first protruding magnetic poles 110b to 110c. It should be noted that the angular interval between the first protruding magnetic poles 110a to 110d is not strictly limited to 90° and may include some variations and errors.

[0150] like Figure 20 As shown, a horizontal magnetic circuit H, a first inclined magnetic circuit Diag_1, and a second inclined magnetic circuit Diag_2 are formed by the first protruding magnetic poles 110a to 110d and the second protruding magnetic pole 120 in the following manner.

[0151] The horizontal magnetic circuit H is formed between the first protruding magnetic pole 110a, the magnetostrictive portion 12, and the first protruding magnetic pole 110b, between the first protruding magnetic pole 110b, the magnetostrictive portion 12, and the first protruding magnetic pole 110c, and between the first protruding magnetic pole 110c, the magnetostrictive portion 12, and the first protruding magnetic pole 110d.

[0152] The first inclined magnetic circuit Diag_1 is formed at approximately 45° between the second protruding magnetic pole 120, the magnetostrictive portion 12, and the first protruding magnetic pole 110b. The second inclined magnetic circuit Diag_2 is formed at approximately -45° between the second protruding magnetic pole 120, the magnetostrictive portion 12, and the first protruding magnetic pole 110c.

[0153] exist Figures 17-20In the specific example shown, the first protruding magnetic poles 110a to 110d, arranged at electrical angle intervals of 90° within a range of electrical angles, are respectively wound with excitation coils 130a to 130d and angle detection coils 150a to 150d with four poles.

[0154] It should be noted that within the first magnetic pole segment 101A, four protruding magnetic poles 110 can be arranged at angular intervals narrower than 90°. Specifically, four protruding magnetic poles 110 can be arranged at electrical angle intervals of approximately 80° to 85°, which are narrower than 90°.

[0155] [Processing of the magnetostrictive torque angle sensing system 1]

[0156] The processing of Embodiment 2 in the magnetostrictive torque angle sensing system 1 will be described. The configuration and operation of the magnetostrictive torque angle sensing system 1 are as follows: Figure 12 As explained below. (Refer to the following...) Figures 21-24 The angle detection signal and torque detection signal during the rotation and torque input of shaft 10 are described in detail.

[0157] • Torque detection when shaft 10 rotates without torque input:

[0158] Figure 21 This is a characteristic diagram showing the characteristics of the voltage obtained by processing the torque detection signal when the shaft 10 rotates without any torque input to the shaft 10 in the magnetostrictive torque angle sensing system 1 of Embodiment 2.

[0159] Specifically, Figure 21 The characteristics of the magnetostrictive torque angle sensing system 1 in Embodiment 2 are shown, which are obtained by the processing unit 200 correcting the torque detection signal when the shaft 10 rotates without any torque input to the shaft 10 using the angle detection signal.

[0160] Here, when the shaft 10 rotates without any torque input, the processing unit 200 outputs torque data indicating that the torque is 0. That is, even if the torque detection coil 140 has only one pole or multiple poles in an unbalanced position in the circumferential direction, the torque detection will not be adversely affected by the rotation of the shaft 10. It should be noted that when the torque detection coil 140 is set to a multi-pole position in which it is balanced in the circumferential direction, the processing unit 200 can output torque data indicating that the torque is 0 without correcting the torque detection signal using an angle detection signal.

[0161] • Angle detection when shaft 10 rotates without torque input:

[0162] Figure 22This is a characteristic diagram showing the characteristics of the voltage obtained by processing the angle detection signal when the shaft 10 rotates without any torque input to the shaft 10 in the magnetostrictive torque angle sensing system 1 of Embodiment 2.

[0163] Specifically, Figure 22 The characteristics of the phase difference and rotation angle obtained by the processing unit 200 comparing the angle detection signal with the excitation signal when the shaft 10 rotates without any torque input to the shaft 10 are shown in the magnetostrictive torque angle sensing system 1 of Embodiment 2.

[0164] Such as Figure 22 As shown, the phase difference between the angle detection signal and the excitation signal is proportional to the rotation angle of the shaft 10. Therefore, the processing unit 200 pre-creates a table of phase difference and rotation angle, calculates the phase difference between the angle detection signal and the excitation signal, substitutes the phase difference into the table, calculates the angle when the shaft 10 rotates, and outputs it as angle data.

[0165] • Torque detection when there is no rotation of shaft 10 during torque input:

[0166] Figure 23 This is a characteristic diagram showing the characteristics of the voltage obtained by processing the torque detection signal when there is a torque input to the shaft 10 without rotating it in the magnetostrictive torque angle sensing system 1 of Embodiment 2.

[0167] Specifically, Figure 23 This refers to the voltage characteristics obtained by the processing unit 200 processing the torque detection signal in the magnetostrictive torque angle sensing system 1 of Embodiment 2 when there is a torque input to the shaft 10 without rotating the shaft 10.

[0168] When focusing on the reason Figure 20 When the torque detection signals obtained from the first inclined magnetic circuit Diag_1 and the second inclined magnetic circuit Diag_2 are described, the first torque detection signal obtained from the first inclined magnetic circuit Diag_1 and the second torque detection signal obtained from the second inclined magnetic circuit Diag_2 have different voltage change rates. Therefore, based on the difference between the first torque detection signal obtained from the first inclined magnetic circuit Diag_1 and the second torque detection signal obtained from the second inclined magnetic circuit Diag_2, a composite torque detection signal with a voltage change rate linear with respect to the torque is obtained. That is, the processing unit 200 calculates the input torque to the shaft 10 based on the composite torque detection signal and outputs it as torque data.

[0169] • Angle detection during torque input without rotation of shaft 10:

[0170] Figure 24This is a characteristic diagram showing the characteristics of the voltage obtained by processing the angle detection signal when there is a torque input to the shaft 10 without rotating it in the magnetostrictive torque angle sensing system 1 of Embodiment 2.

[0171] Specifically, Figure 24 This indicates the phase difference and rotation angle characteristics obtained by the processing unit 200 by comparing the angle detection signal with the excitation signal when the shaft 10 is not rotating and there is a torque input to the shaft 10.

[0172] Such as Figure 24 As shown, regardless of the torque input, the phase difference between the angle detection signal and the excitation signal is 0. Therefore, the processing unit 200 uses a table to input the phase difference = 0 and outputs angle data indicating that the rotation angle = 0. That is, even if there is a torque input on the shaft 10, it will not have any effect on the angle detection.

[0173] The above Figures 21-24 The characteristics of the shaft 10 rotating without torque input to the shaft 10, or torque input to the shaft 10 without rotation of the shaft 10, have been described. In reality, it is possible for torque input to the shaft 10 to occur simultaneously with its rotation. In such cases, the processing unit 200 can be used in parallel. Figures 21-24 The process described is used to calculate both the angle and the torque.

[0174] [Change of extreme numbers]

[0175] In the above-described embodiment 2, the four-pole excitation coils 130a-130d and the four-pole angle detection coils 150a-150d are wound around the first protruding magnetic poles 110a-110d of the four poles of the first magnetic pole segment 101A, but this is not limited to this state. That is, it is not limited to this state. Figures 17-20 For example, the number of poles of the excitation coil 130 and the angle detection coil 150 can be increased.

[0176] When the mechanical center angle of the arc in the magnetic pole section 101 is set to an electrical angle of 360° and n is set to a positive integer of 2 or more, a first protruding magnetic pole 110 with 2n poles spaced at electrical angle intervals of (360 / 2n)° can be provided within the first magnetic pole section 101A, and the excitation coil 130 and the angle detection coil 150 can be wound around the first protruding magnetic pole 110 with 2n poles respectively. In this case, the first excitation coil 131 and the second excitation coil 132 are alternately arranged at electrical angle intervals of (360 / 2n)°. It should be noted that within the first magnetic pole section 101A, the first protruding magnetic pole 110 with 2n poles can be provided at an angular interval narrower than the electrical angle (360 / 2n)°. Specifically, when n = 4, eight first protruding magnetic poles 110 can be provided at an interval of approximately 40°, which is narrower than the electrical angle (360 / 8)° = 45°. Therefore, excitation coils 130 and angle detection coils 150 with any number of poles can be used to detect angle and torque in a non-interfering manner using a single sensor, and the replacement of magnetic pole section 101 relative to shaft 10 becomes easy.

[0177] Alternatively, a first protruding magnetic pole 110 that does not wind around the first excitation coil 131 and the second excitation coil 132 can be provided within the first magnetic pole segment 101A for more than 2n.

[0178] [Effects obtained from Implementation Method 2]

[0179] The following describes Implementation Method 2 and its effects.

[0180] (2-1):

[0181] The magnetostrictive torque angle sensor 100 described in Embodiment 2 has a shaft 10 and a magnetic pole portion 101. The shaft 10 has a magnetostrictive portion 12, and the magnetic pole portion 101 is disposed around the shaft 10. The magnetic pole portion 101 is formed in an arc shape and has a first magnetic pole section 101A and a second magnetic pole section 101B disposed opposite to the first magnetic pole section 101A at an axial distance. The first magnetic pole section 101A has a plurality of first protruding magnetic poles 110 that protrude radially toward the shaft 10. An excitation coil 130 and an angle detection coil 150 are each wound around at least four poles of the plurality of first protruding magnetic poles 110. The at least four-pole excitation coil 130 is configured by alternating arrangements of first excitation coils 131 and second excitation coils 132. First excitation signals and second excitation signals with different phases are supplied to the first excitation coils 131 and the second excitation coils 132, respectively. The second magnetic pole segment 101B has a second protruding magnetic pole 120 that protrudes radially toward the shaft 10 at a position different in the circumferential direction from the first protruding magnetic pole 110. A torque detection coil 140 with at least one pole is wound around the second protruding magnetic pole 120. The magnetic resistance between the magnetostrictive portion 12 and the first protruding magnetic pole 110 is configured to change periodically with the rotation of the shaft 10. In this magnetostrictive torque-angle sensor 100, a torque detection signal can be obtained from the torque detection coil 140, and an angle detection signal can be obtained from the angle detection coil 150, all within the same sensor. Furthermore, by arranging the arc-shaped magnetic pole portion 101 around the shaft 10, the exchange of the magnetic pole portion 101 becomes easy.

[0182] (2-2):

[0183] In the magnetostrictive torque-angle sensor 100 described in (2-1) above, the magnetoresistive force is configured to vary periodically in the circumferential direction by the radial distance from the central axis of the shaft 10 to the magnetostrictive portion 12, or by the periodic variation in the circumferential direction of the size of the magnetostrictive portion 12 along the axis. Therefore, using the same shaft 10 and magnetic pole portion 101, not only torque but also angle can be detected.

[0184] (2-3):

[0185] In the magnetostrictive torque-angle sensor 100 described in (2-1) to (2-2) above, when n is set to an integer of 2 or more, in the first magnetic pole section 101A, the excitation coil 130 and the angle detection coil 150 are each wound around a first protruding magnetic pole 110 with 2n poles. The excitation coil 130 with 2n poles is configured by alternating poles of a first excitation coil 131 with n poles and a second excitation coil 132 with n poles in the circumferential direction. As a result, the angle and torque can be detected in a non-interfering manner using a single sensor by using an excitation coil 130 and an angle detection coil 150 with any number of poles, and the replacement of the magnetic pole section 101 relative to the shaft 10 becomes easy.

[0186] (2-4):

[0187] In the magnetostrictive torque-angle sensor 100 described in (2-1) to (2-3) above, a first excitation signal is supplied to the first excitation coil 131, and a second excitation signal with a phase difference of 90° from the first excitation signal is supplied to the second excitation coil 132. Thus, angle and torque can be detected in a non-interfering manner using a single sensor, and the replacement of the magnetic pole portion 101 relative to the shaft 10 becomes easy.

[0188] (2-5):

[0189] In the magnetostrictive torque-angle sensor 100 described in (2-1) to (2-4) above, the torque detection coil 140 is disposed in the second magnetic pole segment 101B located between two adjacent first protruding magnetic poles 110 in the circumferential direction. Therefore, not only the angle but also the torque can be detected using the same shaft 10 and the magnetic pole segment 101. Furthermore, the angle and torque can be detected in a non-interfering manner using a single sensor, and the replacement of the magnetic pole segment 101 relative to the shaft 10 becomes easy.

[0190] (2-6):

[0191] The magnetostrictive torque-angle sensing system 1 described in Embodiment 2 includes: a magnetostrictive torque-angle sensor 100 as described in any of (2-1) to (2-5) above; and a processing unit 200 that processes the torque detection signal from the torque detection coil 140 and the angle detection signal from the angle detection coil 150. The processing unit 200 supplies a first excitation signal and a second excitation signal with different phases to the first excitation coil 131 and the second excitation coil 132, respectively, detects the torque applied to the shaft 10 using the torque detection signal from the torque detection coil 140, and detects the angle of the shaft 10 using the angle detection signal from the angle detection coil 150. Therefore, it is possible to realize a magnetostrictive torque-angle sensor 100 and a magnetostrictive torque-angle sensing system 1 that are easy to replace and can detect torque and angle using the same sensor.

[0192] (2-7):

[0193] In the magnetostrictive torque angle sensing system 1 described above (2-6), the processing unit 200 corrects the torque detection signal using the angle detection signal, thereby detecting the torque. Here, even when the torque detection coil 140 has only one pole or multiple poles in an unbalanced position in the circumferential direction, the torque detection will not be adversely affected by the rotation of the shaft 10 due to the above correction. Therefore, a magnetostrictive torque angle sensor 100 and a magnetostrictive torque angle sensing system 1 that are easy to replace and can detect both torque and angle using the same sensor can be realized.

[0194] Explanation of reference numerals in the attached figures

[0195] 1: Magnetostrictive torque and angle sensing system; 10: Shaft; 11: Inner shaft section; 12: Magnetostrictive section; 100: Magnetostrictive torque and angle sensor; 101: Magnetic pole section; 101A: First magnetic pole section; 101B: Second magnetic pole section; 110, 110a-110d: First protruding magnetic pole; 120, 120a, 120c: Second protruding magnetic pole; 130, 130a-130d: Excitation coil; 131: First excitation coil; 132: Second excitation coil; 140, 140a, 140d: Torque detection coil; 150, 150a-150d: Angle detection coil; 190: Interval adjustment section; 200: Processing section; H: Horizontal magnetic circuit; Diag_1: First inclined magnetic circuit; Diag_2: Second inclined magnetic circuit.

Claims

1. A magnetostrictive torque angle sensor having a shaft and a magnetic pole portion, the shaft having a magnetostrictive portion, the magnetic pole portion being disposed around the shaft, wherein in the magnetostrictive torque angle sensor, The magnetic pole portion is formed in an arc shape and includes a first magnetic pole segment and a second magnetic pole segment that is axially spaced apart from the first magnetic pole segment. The first magnetic pole segment has a first protruding magnetic pole that projects radially toward the axis. The second magnetic pole segment has a second protruding magnetic pole that protrudes radially toward the axis at a position different in the circumferential direction from that of the first protruding magnetic pole. An excitation coil and an angle detection coil are wound around the first protruding magnetic pole. A torque detection coil is wound around the second protruding magnetic pole. The magnetic resistance between the magnetostrictive portion and the first protruding magnetic pole is configured to change periodically as the shaft rotates.

2. The magnetostrictive torque angle sensor according to claim 1, wherein, The magnetoresistive force is configured to vary periodically in the circumferential direction by the radial distance from the central axis of the shaft to the magnetostrictive part, or by the circumferential direction by the size of the magnetostrictive part along the axis.

3. The magnetostrictive torque angle sensor according to claim 1, wherein, The mechanical center angle of the arc in the magnetic pole section is set to an electrical angle of 360°. The excitation coil is positioned at four protruding magnetic poles within the first magnetic pole segment, spaced at electrical angles of 90°. The angle detection coil is positioned at four protruding magnetic poles within the first magnetic pole segment, at electrical angle intervals of 90°. The torque detection coil is positioned within the second magnetic pole segment as the second protruding magnetic pole at two locations with an electrical angle of 180°.

4. The magnetostrictive torque angle sensor according to claim 1, wherein, The mechanical center angle of the arc in the magnetic pole section is set to an electrical angle of 360°. The excitation coil is disposed at least at one location on the first protruding magnetic pole. The angle detection coil is disposed at least at two locations within the first magnetic pole segment on the first protruding magnetic pole. The torque detection coil is positioned within the second magnetic pole segment as the second protruding magnetic pole at two locations with an electrical angle of 180°.

5. The magnetostrictive torque angle sensor according to claim 1, wherein, The mechanical center angle of the arc in the magnetic pole section is set to an electrical angle of 360°. The excitation coil is disposed at least at two locations within the first magnetic pole segment, forming the first protruding magnetic pole at an electrical angle of 180°. The angle detection coil is disposed at least at two locations within the first protruding magnetic poles of the first magnetic pole segment. The torque detection coil is positioned at a location on the second protruding magnetic pole within the second magnetic pole segment.

6. A magnetostrictive torque angle sensing system, comprising: The magnetostrictive torque angle sensor as described in any one of claims 1 to 4; and The processing unit processes the torque detection signal from the torque detection coil and the angle detection signal from the angle detection coil. The processing unit is configured to: An excitation signal is supplied to the excitation coil; The torque applied to the shaft is detected by a torque detection signal from the torque detection coil; and The angle of the shaft is detected by an angle detection signal from the angle detection coil.

7. A magnetostrictive torque angle sensing system, comprising: The magnetostrictive torque angle sensor as described in claim 5; and The processing unit processes the torque detection signal from the torque detection coil and the angle detection signal from the angle detection coil. The processing unit is configured to: An excitation signal is supplied to the excitation coil; The angle of the shaft is detected by an angle detection signal from the angle detection coil; and The torque detection signal from the torque detection coil is corrected using the angle detection signal from the angle detection coil, thereby detecting the torque applied to the shaft.

8. A magnetostrictive torque angle sensor having a shaft and a magnetic pole portion, the shaft having a magnetostrictive portion, the magnetic pole portion being disposed around the shaft, wherein in the magnetostrictive torque angle sensor, The magnetic pole portion is formed in an arc shape and includes a first magnetic pole segment and a second magnetic pole segment that is axially spaced apart from the first magnetic pole segment. The first magnetic pole segment has a plurality of first protruding magnetic poles that project radially toward the axis. The excitation coil and the angle detection coil are each wound around at least four of the plurality of first protruding magnetic poles. The at least four-pole excitation coil is composed of alternating first and second excitation coils. A first excitation signal and a second excitation signal with different phases are supplied to the first excitation coil and the second excitation coil, respectively. The second magnetic pole segment has a second protruding magnetic pole that protrudes radially toward the axis at a position different in the circumferential direction from that of the first protruding magnetic pole. A torque detection coil with at least one pole is wound around the second protruding magnetic pole. The magnetic resistance between the magnetostrictive portion and the first protruding magnetic pole is configured to change periodically as the shaft rotates.

9. The magnetostrictive torque angle sensor according to claim 8, wherein, The magnetoresistive force is configured to vary periodically in the circumferential direction by the radial distance from the central axis of the shaft to the magnetostrictive part, or by the circumferential direction by the size of the magnetostrictive part along the axis.

10. The magnetostrictive torque angle sensor according to claim 8, wherein, When n is set to an integer greater than 2 In the first magnetic pole segment, the excitation coil and the angle detection coil are each wound around the first protruding magnetic pole of the 2n pole. The excitation coil of the 2n pole is composed of the first excitation coil of the n pole and the second excitation coil of the n pole, which are arranged alternately in the circumferential direction.

11. The magnetostrictive torque angle sensor according to claim 8, wherein, The first excitation signal is supplied to the first excitation coil. A second excitation signal with a phase difference of a fixed angle from the first excitation signal is supplied to the second excitation coil.

12. The magnetostrictive torque angle sensor according to claim 8, wherein, The torque detection coil is positioned in the second magnetic pole segment, which is located in the middle of the first protruding magnetic poles, which are adjacent to each other in the circumferential direction.

13. A magnetostrictive torque angle sensing system, comprising: The magnetostrictive torque angle sensor as described in any one of claims 8 to 12; and The processing unit processes the torque detection signal from the torque detection coil and the angle detection signal from the angle detection coil. The processing unit is configured to: A first excitation signal and a second excitation signal with different phases are supplied to the first excitation coil and the second excitation coil, respectively; The torque applied to the shaft is detected by a torque detection signal from the torque detection coil; and The angle of the shaft is detected by an angle detection signal from the angle detection coil.

14. The magnetostrictive torque angle sensing system according to claim 13, wherein, The processing unit corrects the torque detection signal using the angle detection signal, thereby detecting the torque.

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