JP6654025B2 - Sensor for torque measurement and bearing with sensor - Google Patents

Description

  The present invention relates to a magnetostrictive torque measuring sensor that is used by being incorporated in various types of mechanical devices and that can measure a torque applied to a detected member, and a sensor-equipped bearing.

  In the field of automobiles, in recent years, torque transmitted by a torque transmission member constituting a power train (power transmission mechanism) is measured, and the output of the power source (engine, electric motor) is controlled or the speed is changed using the measurement result. The development of a system for executing gear shift control of a machine is in progress.

  On the other hand, Patent Literature 1 discloses a magnetostrictive torque measuring sensor that measures torque transmitted by a rotating shaft by utilizing an inverse magnetostrictive effect generated on the rotating shaft. The torque measuring sensor described in Patent Document 1 includes a pair of impedance units each including a plurality of detection coils that increase inductance when a torque in a predetermined direction is applied to the rotating shaft; There is provided a bridge circuit in which a total of four impedance units are arranged on four sides, including a pair of impedance units composed of a plurality of detection coils for reducing inductance when a torque is applied to a shaft in a predetermined direction. Then, the torque can be measured based on a midpoint potential difference of the bridge circuit when an AC voltage is applied to the bridge circuit.

  In the case of the torque measuring sensor described in Patent Document 1, when the bridge circuit breaks down, the torque measurement cannot be continued.

Japanese Patent No. 4888015

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and invents a magnetostrictive torque measuring sensor to realize a structure capable of continuously measuring torque even when one bridge circuit breaks down.

The torque measurement sensor according to the present invention includes a plurality of coil layers provided on a member to be detected to which a torque is applied and opposed to a portion to be detected which changes a magnetic permeability by applying a torsional stress according to the torque. .
The coil layers are stacked and arranged in a direction facing the detection target.
Each of the coil layers includes a plurality of detection coils (for example, arranged in a circumferential direction of the detected member).
In addition, a bridge circuit in which four impedance portions each of which is a part of the detection coils constituting each of the coil layers is arranged on four sides, and a remaining one of the detection coils constituting each of the coil layers is provided. And a bridge circuit in which four impedance sections each composed of a detection coil are arranged on four sides.
Each of the bridge circuits generates a midpoint potential difference corresponding to a torque applied to the detected member in a state where an AC voltage is applied.

In a first aspect of the torque measuring sensor of the present invention, as well as to eight the total number of the coil layer, that make up the impedance unit, one for each of the coil layer.
In this case, for example, for each of the bridge circuits, of the four impedance units (four coil layers), each detection coil that constitutes two impedance units (constitutes two coil layers) is connected to the detected coil. When a torque is applied to the member in a predetermined direction, the inductance is increased, and each of the detection coils constituting the remaining two impedance units (constituting the remaining two coil layers) is provided to the detected member by a predetermined amount. The inductance can be reduced when a directional torque is applied.

Further, in the second embodiment of the torque measuring sensor of the present invention, as well as to four of the total number of the coil layer, that make up the impedance unit two per the coil layer.
In this case, for example, for each of the bridge circuits, each of the detection coils constituting two impedance units (constituting one coil layer) among the four impedance units (two coil layers) is connected to the detection target. When a torque is applied to the member in a predetermined direction, the inductance is increased, and each of the detection coils constituting the remaining two impedance units (constituting the remaining one coil layer) is provided to the detected member by a predetermined value. The inductance can be reduced when a directional torque is applied.

  Further, when implementing the sensor for torque measurement of the present invention, the respective coil layers are opposed to the detected portion provided on the axial side surface of the detected member in the axial direction of the detected member. For example, when a torque in a predetermined direction is applied to the detected member, the detection coil that increases the inductance may be radiated with respect to the radiation direction about the central axis of the detected member. The outer side of the direction may have a one-side inclined side inclined toward the one side in the circumferential direction of the detected member (preferably 40 to 50 °, more preferably 45 °). At the same time, the detection coil, which reduces the inductance when a torque in a predetermined direction is applied to the detected member, is moved outward in the radial direction with respect to the radial direction about the central axis of the detected member. In addition, the detected member may have another side inclined side inclined toward the other side in the circumferential direction (preferably 40 to 50 °, more preferably 45 °).

  Further, when implementing the sensor for torque measurement of the present invention, the respective coil layers are centered on the center axis of the detected member with respect to the detected portion provided on the peripheral surface of the detected member. In the case where the detection member is to be opposed in the radial direction (radial direction), for example, a detection coil that increases inductance when a torque in a predetermined direction is applied to the detection target member is provided in the axial direction of the detection target member. The one-sided inclined side may be inclined toward the one side in the circumferential direction of the member to be detected (preferably 40 to 50 °, more preferably 45 °) toward one side in the axial direction. it can. Along with this, the detection coil, which reduces the inductance when a torque in a predetermined direction is applied to the detected member, is moved toward one side in the axial direction with respect to the axial direction of the detected member. It is possible to have another side inclined side inclined toward the other side in the circumferential direction (preferably 40 to 50 °, more preferably 45 °).

  The sensor-equipped bearing of the present invention includes a bearing and the above-described torque measuring sensor of the present invention supported on a portion of the bearing that does not rotate during use (for example, a stationary wheel). Prepare.

  In the case of the torque measuring sensor and the sensor-equipped bearing of the present invention configured as described above, two bridge circuits for measuring torque are provided. Therefore, even if one of the bridge circuits fails, the measurement of torque can be continued by the other bridge circuit.

FIG. 4 is a cross-sectional view schematically illustrating a torque measuring sensor in a used state according to a first example of an embodiment of the present invention. Similarly, FIG. 2 is a diagram illustrating eight coil layers constituting a detection unit of the torque measurement sensor as viewed from the right side in FIG. 1. Similarly, an exploded perspective view of eight coil layers constituting a detection unit of the torque measurement sensor. Similarly, the figure which looked at the 1st-4th coil layer from the right side of FIG. Similarly, FIGS. 4A and 4D are enlarged views of the upper ends of FIGS. 4A and 4D, and FIGS. 4B and 4C are enlarged views of the upper ends of FIGS. 4B and 4C. FIG. 3 is a diagram showing two bridge circuits constituting the torque measurement sensor. FIG. 9 is a cross-sectional view schematically showing a torque measuring sensor in a used state according to a second example of the embodiment of the present invention. Similarly, FIG. 8 is a diagram of four coil layers constituting a detection unit of the torque measurement sensor, as viewed from the right side in FIG. 7. Similarly, an exploded perspective view of four coil layers constituting a detection unit of the torque measurement sensor. Similarly, the figure which looked at the 1st, 2nd coil layer from the right side of FIG. The figure similar to FIG. 10 regarding the 3rd example of Embodiment of this invention. FIG. 14 is a half sectional view showing a fourth example of the embodiment of the present invention, with a part thereof omitted; FIG. 14 is a half sectional view showing a fifth example of an embodiment of the present invention, with a part thereof omitted; The figure (A) which looked at the sensor for torque measurement about the 6th example of an embodiment of the invention from the outside in the use state, and the figure (B) which looked at (A) from the right. Similarly, the development view which looked at the eight coil layers which comprise the detection part of the sensor for torque measurement from the radial outside. Similarly, the development view which looked at the 1st-4th coil layer from the radial direction outer side in the state of a single body, respectively. The figure (A) which looked at the sensor for torque measurement about the 7th example of an embodiment of the invention from the outside in the use state, and the figure (B) which looked at (A) from the right. Similarly, the development view which looked at four coil layers which comprise the detection part of the sensor for torque measurement from the radial outside. Similarly, the development view which looked at the 1st, 2nd coil layer from the radial direction outside in the state of a single body, respectively. The figure similar to FIG. 19 regarding the 8th example of Embodiment of this invention. FIG. 21 is a half sectional view showing a ninth example of the embodiment of the present invention, with a part thereof omitted; FIG. 19 is a half sectional view showing a tenth example of an embodiment of the present invention with a part thereof omitted;

[First Example of Embodiment]
A first example of an embodiment of the present invention will be described with reference to FIGS.
The torque measuring sensor 1 of the present embodiment constitutes a torque measuring device together with a detected member 2 as schematically shown in FIG. 1, for example.

  The member to be detected 2 may constitute various mechanical devices (for example, constitute a power train of an automobile), a gear, a pulley, a flywheel, a sprocket, a flange for a joint, or a crankshaft of an engine and a case of a torque converter. Is a disk-shaped member to which torque is applied (transmitted), such as a drive plate for transmitting torque, and is assembled at a predetermined use location. The detected member 2 has a detected portion 3 and at least a part or the whole including the detected portion 3 is made of a material having magnetostrictive characteristics. In particular, in the case of this example, as the material having the magnetostrictive property, iron-based alloy steel such as iron or pure iron having good magnetostrictive property, SUS (stainless steel), SNCM (nickel chrome molybdenum steel), carbon steel Use｝. Further, in the case of the present example, the detected member 2 is sandwiched between a portion of the one side in the axial direction (the right side surface in FIG. 1) of the detected member 2 in the radial direction (points P and Q in FIG. 1). 2) is a toroidal detection part 3 whose axial position does not change in the circumferential direction and the radial direction.

  Further, the torque measuring sensor 1 includes a ring-shaped detection unit 4 and a pair of bridge circuits 5a and 5b (FIG. 6) including the detection unit 4. In such a torque measuring sensor 1, the detection unit 4 is arranged coaxially with the detected unit 3, and the detection unit 4 is axially closely opposed to the detected unit 3 (over the entire circumference). In a state where the interval in the axial direction is constant).

The detection unit 4 includes eight coil layers (first to fourth coil layers 6 to 9 and first to fourth coil layers 6 to 9). These eight coil layers (first to fourth coil layers 6 to 9 and first to fourth coil layers 6 to 9) are each configured in a ring shape, and are coaxially arranged with each other. They are stacked in the axial direction. Of these eight coil layers (first to fourth coil layers 6 to 9 and first to fourth coil layers 6 to 9), they are located on the side closer to the detected portion 3 (the left side in FIG. 1). One coil layer group composed of four coil layers (first to fourth coil layers 6 to 9) and four coil layers (first to fourth coil layers) located farther from the detected portion 3 (right side in FIG. 1). The other coil layer group composed of the fourth coil layers 6 to 9) has the same configuration as that of the other coil layer group except that the axial distance from the detected portion 3 is different. Therefore, in the case of this example, for convenience, the first to fourth coil layers forming the one coil layer group and the first to fourth coil layers forming the other coil layer group are the same. It is represented by reference numerals 6 to 9.
Further, of the two bridge circuits 5a and 5b, one bridge circuit 5a is configured for the one coil layer group, and the other bridge circuit 5b is configured for the other coil layer group. Have been.

  The first to fourth coil layers 6 to 9 constituting the both coil layer groups are arranged such that the first coil layer 6, the second coil layer 7, and the third coil The layers 8 and the fourth coil layers 9 are stacked and arranged in this order. The first coil layer 6 and the second coil layer 7 are formed separately on one side and the other side of a single substrate (including a flexible substrate) not shown. The third coil layer 8 and the fourth coil layer 9 are formed separately on one side and the other side of another substrate (including a flexible substrate) not shown. An insulating layer (not shown) is provided between the second coil layer 7 and the third coil layer 8. Further, an insulating layer (not shown) is provided between the fourth coil layer 9 of the one coil layer group and the first coil layer 6 of the other coil layer group.

  As shown in (A) {(B), (C), (D)} of FIG. 4, the first coil layer 6 (the second coil layer 7, the third coil layer 8, the fourth coil layer 8, The coil layer 9) includes a plurality of first detection coils 10, 10 (second detection coils 11, 11, third detection coils 12, 12, and fourth detection coils 13, 13). Each of these first detection coils 10 and 10 (second detection coils 11 and 11, third detection coils 12 and 12, and fourth detection coils 13 and 13) has their respective axial directions aligned with the axial direction of the detected part 3. In a state where they are made to coincide with each other, they are arranged at equal pitches in the circumferential direction on a circumference that can face the detected portion 3 in the axial direction. The first detection coils 10, 10 (second detection coils 11, 11, third detection coils 12, 12, and fourth detection coils 13, 13) are adjacent to each other in the circumferential direction. A pair of first detection coils 10, 10 (second detection coils 11, 11, third detection coils 12, 12, fourth detection coils 13, 13) adjacent to each other at any one position in the circumferential direction is excluded. Are connected in series to form the first impedance section 18 (second impedance section 19, third impedance section 20, and fourth impedance section 21) of the bridge circuit 5a (5b). . 2 to 5, the first detection coils 10, 10 (second detection coils 11, 11, third detection coils 12, 12, fourth detection coils 13, 13) adjacent in the circumferential direction are connected to each other. Illustration of wiring (wiring structure including vias) is omitted.

  The total number of the first detection coils 10 and 10 constituting the first coil layer 6, the total number of the second detection coils 11 and 11 constituting the second coil layer 7, and the total number of the third coil layers 8 The total number of the third detection coils 12 and 12 and the total number of the fourth detection coils 13 and 13 constituting the fourth coil layer 9 are made equal to each other. In the case of this example, the phases of the first to fourth coil layers 6 to 9 in the circumferential direction of the first to fourth detection coils 10 to 13 match each other.

  Each of the first to fourth detection coils 10 to 13 has a substantially rhombic shape in plan view (shape viewed from the axial direction). That is, the first to fourth detection coils 10 to 13 are formed by a pair of radial side portions (14 a, 14 b, 14 c, 14 d) existing on both sides in the radial direction of the first to fourth coil layers 6 to 9. ), (15a, 15b, 15c, 15d) and a pair of circumferential side portions (16a, 16b, 16c, 16d) present on both sides in the circumferential direction of the first to fourth coil layers 6 to 9. ), (17a, 17b, 17c, 17d). The planar shape of each of the radial side portions (14a, 14b, 14c, 14d) and (15a, 15b, 15c, 15d) is the center axis of the first to fourth coil layers 6 to 9, respectively. It has an arc shape with the center as a center or a straight line in contact with the arc. The planar shape of each of the circumferential side portions (16a, 16b, 16c, 16d) and (17a, 17b, 17c, 17d) is the central axis of the first to fourth coil layers 6 to 9, respectively. And a straight line inclined by 45 ° with respect to the radiation direction centered at. However, the circumferential sides (16a, 16d) and (17a, 17d) constituting the first and fourth detection coils 10, 13 and the second and third detection coils 11, 12 are formed. At the circumferential side portions (16b, 16c) and (17b, 17c), the inclination directions at 45 ° with respect to the radiation direction are opposite to each other. In other words, the circumferential side portions (16a, 16d) and (17a, 17d) of the first and fourth detection coils 10, 13 are located more outward in the radiation direction with respect to the radiation direction. It is inclined 45 ° (inclined by + 45 ° with respect to the radial direction) in a direction toward one side in the circumferential direction (clockwise direction in FIGS. 2 to 5). On the other hand, the circumferential side portions (16b, 16c) and (17b, 17c) constituting the second and third detection coils 11, 12 are located outside the radiation direction with respect to the radiation direction. As it moves, it is inclined at 45 ° (−45 ° with respect to the radial direction) in the direction toward the other side in the circumferential direction (counterclockwise direction in FIGS. 2 to 5).

  The first to fourth detection coils 10 to 13 constituting the first to fourth coil layers 6 to 9 are in a circular plate shape or a disk shape in a state where mutual electrical contact (short circuit) is prevented. Are supported and fixed to one side surface and the other side surface of each substrate formed in a flat plate shape. When each of the substrates is a flexible substrate, the flexible substrate may be made of, for example, a circular plate or a disk having a non-conductive property and a strength necessary to maintain the shape of the detection unit 4. It can be fixed to a side surface of a support member having a shape (a side surface facing the detected portion 3). Although not shown, a circular plate or a circle is provided on the back side of the first to fourth coil layers 6 to 9 (on the right side in FIG. 1 which is opposite to the detected portion 3 in the axial direction). A plate-shaped magnetic core or the like can be arranged adjacently. Further, the magnetic core may be used as the support member.

  As described above, of the two bridge circuits 5a and 5b, one bridge circuit 5a is configured for the one coil layer group, and the other bridge circuit 5b is connected to the other coil layer group. It is composed of groups. As shown in FIG. 6, each of the two bridge circuits 5a and 5b includes a bridge unit 22, an oscillator 23, and a lock-in amplifier 24.

  The bridge portion 22 is formed by connecting the first impedance portion 18 and the third impedance portion 20 in series and by connecting the second impedance portion 19 and the fourth impedance portion 21 in series. Are connected in parallel with each other. In the case of the present example, the first impedance section 18 and the second impedance section are provided on one set of opposite sides α and β of the two sets of opposite sides (α, β) (γ, δ) of the bridge section 22. 19, and the third impedance section 20 and the fourth impedance section 21 are arranged on another pair of opposite sides γ and δ.

Further, the oscillator 23 applies an AC voltage to both ends of the bridge section 22.
The lock-in amplifier 24 detects the midpoint potential difference (the potential difference between the point X between the two sides α and γ and the point Y between the two sides β and δ) of the bridge section 22. -Amplify and generate output V. When the present invention is implemented, a device other than the lock-in amplifier 24 can be used as the potential difference detecting element for detecting the midpoint potential difference.
In the case of this example, the oscillator 23 and the lock-in amplifier 24 are supported and fixed on any one of the substrates on which the first to fourth coil layers 6 to 9 are supported and fixed. However, when practicing the present invention, the oscillator 23 and the lock-in amplifier 24 can be supported and fixed on a substrate different from the substrate on which the first to fourth coil layers 6 to 9 are supported and fixed.

  In the case of this example, the first to fourth impedance units 18 to 21 (the first to fourth detection coils 10 to 13) are applied by applying an AC voltage to both ends of the bridge unit 22 by the oscillator 23. ), The first detection coils 10, 10 (second detection coils 11, 11, third detection coils 12, 12, fourth detection coils 13, 13) that are circumferentially adjacent to each other flow. The direction of the current is as shown by arrows A and B in FIGS. 4A and 5D and FIG. 5A, or as shown in FIGS. 4B and 5C and FIG. As shown by arrows C and 2, the directions are opposite to each other. Thus, among the first detection coils 10, 10 (second detection coils 11, 11, third detection coils 12, 12, and fourth detection coils 13, 13) circumferentially adjacent to each other, they are arranged adjacently in the circumferential direction. The directions of the currents flowing through the circumferential side portions 16a, 17a {(16b, 17b), (16c, 17c), (16d, 17d)} of each other are the same as each other. In the case of this example, in order to realize the above-described current flow (direction), the detection coils adjacent to the first to fourth detection coils 10 to 13 in the winding direction of the conductor wire and in the circumferential direction are related. It regulates the way in which they are connected in series. In the case of this example, in the neutral state in which no torque is applied to the detected member 2, the first to fourth bridges 22 are in an equilibrium state (a state in which the midpoint potential difference is 0). The configuration of the impedance units 18 to 21 is regulated.

  In the case of the torque measuring device of the present embodiment configured as described above, in use, by applying an AC voltage to both ends of the bridge section 22 by the oscillator 23 for each of the two bridge circuits 5a and 5b, A magnetic field is generated around the first to fourth detection coils 10 to 13 by passing an alternating current through the first to fourth impedance units 18 to 21 (the first to fourth detection coils 10 to 13). In this state, when the torque T is applied to the detected member 2, the equilibrium state of the bridge portion 22 is broken, and the midpoint potential difference of the bridge portion 22 changes by an amount corresponding to the torque T. This point will be specifically described below.

  First, when a torque T as shown in FIG. 5 is applied to the detected member 2, a torsional stress corresponding to the torque T is applied to the detected portion 3. That is, the detected portion 3 has a tensile stress (+ σ) in the + 45 ° direction with respect to the radial direction about the center axis of the detected member 2 and a compression stress in the −45 ° direction with respect to the radial direction. Stress (−σ) acts. In the + 45 ° direction in which the tensile stress (+ σ) acts, the magnetic permeability of the detected portion 3 increases, and in the −45 ° direction in which the compressive stress (−σ) acts, The magnetic permeability of the detected part 3 decreases (reverse magnetostriction effect).

  On the other hand, among the first to fourth detection coils 10 to 13 that constitute the detection unit 4 of the torque measurement sensor 1 (constitute the first to fourth impedance units 18 to 21), The circumferential side portions (16a, 16d) and (17a, 17d) of the four detection coils (+ 45 ° coils) 10, 13 are located at the center axes of the first and fourth coil layers 6, 9 (the detected portions). (Central axis 3) is inclined by + 45 ° with respect to the radiation direction. That is, the circumferential side portions (16a, 16d) and (17a, 17d) of the first and fourth detection coils 10, 13 are located in the direction in which the magnetic permeability of the detection target 3 decreases (in the radiation direction). It is installed so that the magnetic flux passes through it (in the −45 ° direction relative to it) (to reduce the inductance of the first and fourth detection coils 10 and 13). On the other hand, the circumferential side portions (16b, 16c) and (17b, 17c) of the second and third detection coils (−45 ° coils) 11 and 12 are arranged in the second and third coil layers 7. , 8 (-45 °) with respect to the radiation direction about the center axis of the detected part 3 (center axis of the detected part 3). That is, the circumferential side portions (16b, 16c) and (17b, 17c) of the second and third detection coils 11, 12 are located in the direction in which the magnetic permeability of the detection target 3 increases (in the radiation direction). It is installed so that the magnetic flux passes through (in the + 45 ° direction) (the inductance of the second and third detection coils 11 and 12 increases).

  For this reason, when the above-described torque T is applied to the detection target member 2, the inductance of the first to fourth detection coils 10 to 13 (the impedance of the first to fourth impedance units 18 to 21) increases. , And changes by an amount corresponding to the torque T. Accordingly, the equilibrium state of the bridge portion 22 is broken, and the midpoint potential difference of the bridge portion 22 changes by an amount corresponding to the torque T. Therefore, by detecting and amplifying the midpoint potential difference by the lock-in amplifier 24, an output V corresponding to the torque T can be obtained.

When the direction of the torque T applied to the detection target member 2 is opposite to the direction shown in FIG. 5, the first and fourth detection coils 10 and 13 are opposite to the above case. As the inductance increases, the inductance of the second and third detection coils 11, 12 decreases. In this case as well, the output V is in accordance with the torque T. Note that the polarity of the output V is reversed depending on the direction of the torque T applied to the detected member 2.
Therefore, if the relationship between the output V and the torque T is checked in advance, the direction and the magnitude of the torque T can be obtained from the output V using the relationship.

  In particular, in the case of this example, the circumferential side portions (16a, 16d) and (17a, 17d) of the first and fourth detection coils 10, 13 are inclined at + 45 ° with respect to the radiation direction. At the same time, the circumferential sides (16b, 16c) and (17b, 17c) of the second and third detection coils 11, 12 are inclined by -45 ° with respect to the radiation direction. . At the same time, a configuration is adopted in which the first to fourth detection coils 10 to 13 are arranged at equal pitches over the entire circumference on a circumference that can be opposed to the detection target 3 in the axial direction. I have. Therefore, by adopting these configurations, it is possible to increase the change in impedance of the first to fourth impedance units 18 to 21 per unit torque. Therefore, it is possible to increase the amount of change in the midpoint potential difference and the output V of the bridge section 22 per unit torque. As a result, in the case of the present example, the shape of the portion provided with the detected portion 3 in the axial side surface of the detected member 2 does not need to be specially devised. The torque applied to the detection target member 2 can be reduced without employing a configuration that increases the processing cost, such as forming a plurality of ribs (parts for increasing the change in magnetic permeability per unit torque) in the bent portion. T can be measured with high sensitivity.

  Further, the torque measuring sensor 1 of the present embodiment includes two bridge circuits 5a and 5b for measuring the torque T applied to the detected member 2. Therefore, even if one of the bridge circuits 5a (5b) fails, the measurement of the torque T can be continued by the other bridge circuit 5b (5a). In the case of this example, for example, the measurement error can be improved by taking the average of the measured values of the torque T by the two bridge circuits 5a and 5b. Further, for example, by comparing the measured values of the torque T by the two bridge circuits 5a and 5b, it is possible to determine whether or not the bridge circuits 5a and 5b have a failure.

[Second Example of Embodiment]
A second example of the embodiment of the present invention will be described with reference to FIGS.
In the case of this example, the total number of the coil layers constituting the detecting unit 4a of the torque measuring sensor 1a is four. Among these four coil layers (the first and second coil layers 6a and 7a and the first and second coil layers 6a and 7a), the one located on the side closer to the detection target 3 (the left side in FIG. 7). One coil layer group consisting of two coil layers (first and second coil layers 6a and 7a) and two coil layers (first and second coil layers) located on the side (the right side in FIG. The other coil layer group composed of the two coil layers 6a and 7a) has the same configuration as that of the other coil layer group except that the axial distance from the detected portion 3 is different.
Also, in the case of this example, one bridge circuit 5a (see FIG. 6A) is formed for the one coil layer group, and one bridge circuit is formed for the other coil layer group. A bridge circuit 5b (see FIG. 6B) is configured.

  The first and second coil layers 6a and 7a constituting the two coil layer groups are arranged in the order of the first coil layer 6a and the second coil layer 7a from the side closer to the detected part 3 in the axial direction. Are stacked. The first coil layer 6a and the second coil layer 7a are formed separately on one side and the other side of one substrate (including a flexible substrate). Further, an insulating layer is provided between the second coil layer 7a of the one coil layer group and the first coil layer 6a of the other coil layer group.

  In the case of the present example, the first coil layer 6a includes the first detection coils 10, 10 and the fourth detection coils 13, 13, which are alternately arranged one by one in the circumferential direction and at equal pitches. It consists of. Each of the first detection coils 10, 10 is circumferentially adjacent to each other (except for a pair of first detection coils 10, 10 adjacent to each other at any one position in the circumferential direction). By being connected in series with each other, a first impedance section 18 constituting the bridge circuit 5a (5b) is constituted. The fourth detection coils 13 are adjacent to each other in the circumferential direction (excluding a pair of fourth detection coils 13 adjacent to each other at any one position in the circumferential direction). ) Are connected in series to form a fourth impedance section 21 constituting the bridge circuit 5a (5b). When measuring the torque, the direction of the current flowing through each of the first detection coils 10 and 10 and each of the fourth detection coils 13 and 13 is indicated by arrows A and B in FIG. , So that they are opposite to each other. For this reason, regarding the first and fourth detection coils 10 and 13, the first detection coils 10 and 10 adjacent to each other and the fourth detection coils 13 and 13 adjacent to each other in the winding direction of the conductive wire and the circumferential direction. Regulates how to connect in series. 8 to 10, illustration of wirings (wiring structures including vias) connecting the first detection coils 10, 10 and the fourth detection coils 13, 13, which are adjacent in the circumferential direction, is omitted.

  On the other hand, the second coil layer 7a is configured by arranging the second detection coils 11, 11 and the third detection coils 12, 12 alternately one by one in the circumferential direction and at equal pitches. ing. The second detection coils 11, 11 are adjacent to each other in the circumferential direction (however, a pair of second detection coils 11, 11 adjacent to each other at any one position in the circumferential direction is excluded). ) Are connected in series to form a second impedance section 19 that forms the bridge circuit 5a (5b). Each of the third detection coils 12, 12 adjacent to each other in the circumferential direction (except for a pair of third detection coils 12, 12 adjacent to each other at any one position in the circumferential direction). ) Are connected in series to form a third impedance unit 20 that forms the bridge circuit 5a (5b). Also, when measuring the torque, the direction of the current flowing through each of the second detection coils 11, 11 and each of the third detection coils 12, 12, as shown by arrows C and D in FIG. , So that they are opposite to each other. For this reason, regarding the second and third detection coils 11 and 12, the winding direction of the conductor wire and the second detection coils 11 and 11 adjacent to each other in the circumferential direction and the third detection coils 12 and 12 Regulates how to connect in series. 8 to 10, illustration of wirings (wiring structures including vias) connecting the second detection coils 11, 11 adjacent to each other in the circumferential direction and the third detection coils 12, 12 is omitted.

  Note that the total number of the first and fourth detection coils 10 and 13 constituting the first coil layer 6a and the total number of the second and third detection coils 11 and 12 constituting the second coil layer 7a are mutually different. Equal. Further, in the case of this example, the phase of the arrangement of the first and fourth detection coils 10 and 13 constituting the first coil layer 6a in the circumferential direction and the phase constituting the second coil layer 7a are described. The phases of the arrangement of the second and third detection coils 11 and 12 in the circumferential direction are matched with each other.

In the case of the torque measuring sensor 1a according to the present embodiment having such a configuration, two bridge circuits 5a and 5b for measuring the torque T applied to the detected member 2 are provided. Even when the bridge circuit 5a (5b) fails, the measurement of the torque T can be continued by the other bridge circuit 5b (5a).
Further, in the case of this example, the number of coil layers for forming one bridge circuit 5a (5b) is two instead of four, so that the detection unit 4a is made thinner and the manufacturing cost is reduced. Is easy to reduce.
Other configurations and operations are the same as those of the first example of the above-described embodiment.

[Third Example of Embodiment]
A third example of the embodiment of the present invention will be described with reference to FIG.
In the case of the torque measuring sensor of the present embodiment, a first coil layer 6b and a second coil layer which form a pair of coil layer groups for forming a pair of bridge circuits 5a and 5b (see FIG. 6). The configuration of 7b (how to arrange each detection coil) is different from the case of the second example of the above-described embodiment.

  In the case of this example, each of the first coil layers 6b is arranged in one of the pair of semicircular arcs divided into two equal parts in the circumferential direction (the left semicircular arc in FIG. 11A). By arranging the first detection coils 10 and 10 in the semicircular range on the other side (to the right in FIG. 11A), the fourth detection coils 13 and 13 are arranged at equal pitches in the circumferential direction. It is configured. Further, when measuring the torque, of the first detection coils 10 and 10 and the fourth detection coils 13 and 13 constituting the first coil layer 6b, the two detection coils adjacent to each other in the circumferential direction flow. The directions of the currents are opposite to each other as shown by arrows A and B in FIG. For this reason, regarding the first and fourth detection coils 10 and 13, the first detection coils 10 and 10 adjacent to each other and the fourth detection coils 13 and 13 adjacent to each other in the winding direction of the conductive wire and the circumferential direction. Regulates how to connect in series.

  In the case of the present example, the second coil layer 7b is one of a pair of semicircular arcs divided into two equal parts in the circumferential direction (the left semicircular arc in FIG. 11B). And the third detection coils 12, 12 are arranged at equal pitches in the circumferential direction, respectively, in a semicircular area of the other {right side of FIG. 11B}. It is composed of things. Further, when measuring the torque, of the second detection coils 11 and 11 and the third detection coils 12 and 12 that constitute the second coil layer 7b, the two detection coils that are adjacent to each other in the circumferential direction flow. The directions of the currents are opposite to each other as shown by arrows C and D in FIG. For this reason, regarding the second and third detection coils 11 and 12, the winding direction of the conductor wire and the second detection coils 11 and 11 adjacent to each other in the circumferential direction and the third detection coils 12 and 12 Regulates how to connect in series.

As described above, in the case of the structure of the present example, the first coil layer 6b (second coil layer 7b) is divided into a pair of semicircular arc-shaped regions divided in the circumferential direction into two. The first detection coils 10 and 10 and the fourth detection coils 13 and 13 (the second detection coils 11 and 11 and the third detection coils 12 and 12) are located in the arc-shaped range, respectively. They are arranged side by side in the circumferential direction. For this reason, a wiring structure for connecting the first detection coils 10 and 10 in series and a wiring structure for connecting the fourth detection coils 13 and 13 in series (the second detection coils 11 and 11 The wiring structure for connecting in series and the wiring structure for connecting the third detection coils 12, 12 in series can be easily simplified. Therefore, it is easy to achieve downsizing by simplifying each of these wiring structures.
Other configurations and operations are the same as those in the second example of the above-described embodiment.

[Fourth Example of Embodiment]
A fourth example of the embodiment of the present invention will be described with reference to FIG.
This example shows a specific usage of the torque measuring sensor 1 (1a) according to the first to third examples of the above-described embodiment.
In the usage mode of this example, an annular drive plate 29 made of an iron-based alloy having magnetostrictive characteristics and connecting a crankshaft 26 of an engine 25 and a case 28 forming an outer shell of a torque converter 27 so as to transmit torque is provided. As the member to be detected, the torque applied to the drive plate 29 is measured by the torque measuring sensor 1 (1a). For this reason, on one axial side surface of the drive plate 29, a ring-shaped flat surface portion present near the radial inner end is defined as the detected portion 3a. Then, in a state where the detecting section 4 (4a) of the torque measuring sensor 1 (1a) is axially opposed to the detected section 3a, the torque measuring sensor 1 (1a) is connected to the engine 25. It is supported and fixed to the cylinder block 30.

[Fifth Example of Embodiment]
A fifth example of the embodiment of the present invention will be described with reference to FIG.
This example also shows a specific usage of the torque measuring sensor 1 (1a) of the first to third examples of the above-described embodiment.
In the case of this example, the torque measuring sensor 1 (1a) axially opposed to the detected portion 3a of the drive plate 29a constitutes a sensor-equipped bearing by being combined with the rolling bearing 31. .
The rolling bearing 31 includes an outer ring 32 that is a stationary wheel that does not rotate during use, an inner ring 33 that is a rotating wheel that rotates during use, an outer ring raceway formed on an inner peripheral surface of the outer ring 32, and an outer periphery of the inner ring 33. A plurality of rolling elements (balls in the illustrated example) 34 are provided so as to roll freely between the inner raceway formed on the surface. The outer ring 32 is internally fitted and fixed in a holding recess 35 provided in the cylinder block 30, and the inner ring 33 is externally fitted to a cylindrical portion 36 provided near a radially inner end of the drive plate 29 a. By fixing, the drive plate 29a is rotatably supported with respect to the cylinder block 30.
The torque measuring sensor 1 (1a) is supported and fixed to one axial end (the left end in FIG. 11) of the outer race 32 via an annular holder 37.
Other configurations and operations are the same as those in the fourth example of the above-described embodiment.

[Sixth Example of Embodiment]
A sixth example of the embodiment of the present invention will be described with reference to FIGS.
Each of the torque measuring sensors of the above-described embodiments is of the axially opposed type (facing the detected member in the axial direction), whereas the torque measuring sensor of the present embodiment is of the radial type. It is a facing type (facing in the radial direction with respect to the detected member).

  The torque measuring sensor 1b of the present example constitutes a torque measuring device together with the detected member 2a as schematically shown in FIG. 14, for example.

  The detected member 2a is a rotating shaft that constitutes various mechanical devices (for example, constitutes a power train or a steering device of an automobile) and receives (transmits) torque, and is assembled at a predetermined use location. I have. Such a detected member 2a has a cylindrical outer peripheral surface as a detected portion 3b. The detected member 2a is made of a material having magnetostrictive properties at least partially or entirely including the detected portion 3b. In particular, in the case of this example, as the material having the magnetostrictive property, iron-based alloy steel such as iron or pure iron having good magnetostrictive property, SUS (stainless steel), SNCM (nickel chrome molybdenum steel), carbon steel Use｝.

  Further, the torque measuring sensor 1b has a cylindrical detecting portion 4b arranged coaxially with the detected portion 3b on the radially outer side of the detected portion 3b, and the detecting portion 4b on the inner peripheral surface. And a pair of bridge circuits 5a and 5b (see FIG. 6) including the detection section 4b, and are supported by a portion such as a housing that does not rotate when used. I have.

  The magnetic core 38 is formed in a cylindrical shape by abutting the circumferential ends of a pair of semi-cylindrical magnetic core elements 39, 39.

The detection unit 4b includes eight coil layers (first to fourth coil layers 6c to 9c and first to fourth coil layers 6c to 9c). These eight coil layers (first to fourth coil layers 6c to 9c and first to fourth coil layers 6c to 9c) are each configured in a cylindrical shape, and are arranged coaxially with each other. They are arranged radially. Among these eight coil layers (first to fourth coil layers 6c to 9c and first to fourth coil layers 6c to 9c), 4 located on the side (radially inward) closer to the detected portion 3b. One coil layer group including one coil layer (first to fourth coil layers 6c to 9c) and four coil layers (first to fourth coil layers) located farther (radially outward) from the detected portion 3b. The other coil layer group including the coil layers 6c to 9c) has the same configuration as that of the other coil layer group except that the radial distance (radial dimension) from the detected portion 3b is different. Therefore, in the case of this example, for convenience, the first to fourth coil layers forming the one coil layer group and the first to fourth coil layers forming the other coil layer group are the same. It is represented by reference numerals 6c to 9c.
Further, of the two bridge circuits 5a and 5b, one bridge circuit 5a is configured for the one coil layer group, and the other bridge circuit 5b is configured for the other coil layer group. Have been.

  The first to fourth coil layers 6c to 9c constituting the two coil layer groups are arranged such that the first coil layer 6c and the second coil layer are arranged from the side (radially inside) closer to the detected portion 3b in the radial direction. 7c, the third coil layer 8c, and the fourth coil layer 9c are stacked and arranged in this order. The first coil layer 6c and the second coil layer 7c are formed separately on one side and the other side of a band-shaped flexible substrate (not shown), and are formed by rolling the flexible substrate into a cylindrical shape. , And have a cylindrical shape. The third coil layer 8c and the fourth coil layer 9c are formed separately on one side and the other side of another band-shaped flexible substrate (not shown), and the flexible substrate is rolled into a cylindrical shape. Therefore, it is formed in a cylindrical shape. An insulating layer is provided between the second coil layer 7c and the third coil layer 8c. Further, an insulating layer is also provided between the fourth coil layer 9c of the one coil layer group and the first coil layer 6c of the other coil layer group.

  FIG. 15 is a development view of the two coil layer groups as viewed from the outside in the radial direction. FIGS. 16A to 16D show the diameters of the first to fourth coil layers 6c to 9c. The development view seen from the direction outside is shown.

  The first coil layer 6c (the second coil layer 7c, the third coil layer 8c, and the fourth coil layer 9c) correspond to (A) {(B), (C), (D)} in FIG. As shown, a plurality of first detection coils 10a and 10a (second detection coils 11a and 11a, third detection coils 12a and 12a, and fourth detection coils 13a and 13a) are provided. Each of the first detection coils 10a and 10a (the second detection coils 11a and 11a, the third detection coils 12a and 12a, and the fourth detection coils 13a and 13a) respectively has its own coil surface on the first coil layer 6c (the The second coil layer 7c, the third coil layer 8c, and the fourth coil layer 9c) are arranged at equal pitches in the circumferential direction in the radial direction (the direction facing the detected portion 3b). ing.

  The first detection coils 10a and 10a (second detection coils 11a and 11a, third detection coils 12a and 12a, and fourth detection coils 13a and 13a) are adjacent to each other in the circumferential direction. A pair of first detection coils 10a, 10a (second detection coils 11a, 11a, third detection coils 12a, 12a, and fourth detection coils 13a, 13a) adjacent to each other across both ends of the flexible substrate are excluded. Are connected in series to form the first impedance section 18 (second impedance section 19, third impedance section 20, and fourth impedance section 21) of the bridge circuit 5a (5b). . In FIGS. 15 and 16, the first detection coils 10a and 10a (second detection coils 11a and 11a, third detection coils 12a and 12a, and fourth detection coils 13a and 13a) adjacent in the circumferential direction are connected to each other. Illustration of wiring (wiring structure including vias) is omitted.

  In addition, the total number of the first detection coils 10a and 10a constituting the first coil layer 6c, the total number of the second detection coils 11a and 11a constituting the second coil layer 7c, and the total number of the third coil layers 8c are formed. The total number of the third detection coils 12a, 12a to be formed is equal to the total number of the fourth detection coils 13a, 13a constituting the fourth coil layer 9c. In the case of this example, the first to fourth coil layers 6c to 9c have the same phase of the arrangement of the first to fourth detection coils 10a to 13a in the circumferential direction.

  In the first to fourth detection coils 10a to 13a, the circumferential side portions 40a, 40b, 40c, and 40d are inclined by 45 ° with respect to the axial direction of the first to fourth coil layers 6c to 9c. I have. However, the circumferential side portions 40a and 40d of the first and fourth detection coils 10a and 13a, and the circumferential side portions 40b and 40c of the second and third detection coils 11a and 12a, The inclination directions at 45 ° to the axial direction are opposite to each other. In other words, the circumferential side portions 40a, 40d of the first and fourth detection coils 10a, 13a are arranged so that the circumferential direction is closer to one side (the right side in FIGS. 15 to 16) in the axial direction with respect to the axial direction. It is inclined by 45 ° in the direction toward one side (the upper side in FIGS. 15 and 16) (inclined by + 45 ° with respect to the axial direction). On the other hand, the circumferential side portions 40b, 40c of the second and third detection coils 11a, 12a are more circular toward the one side (the right side in FIGS. 15 to 16) in the axial direction with respect to the axial direction. It is inclined 45 ° (−45 ° with respect to the axial direction) in the direction toward the other side in the circumferential direction (the lower side in FIGS. 15 and 16).

  As described above, of the two bridge circuits 5a and 5b (see FIG. 6), one bridge circuit 5a is configured for the one coil layer group, and the other bridge circuit 5b is The other coil layer group is configured. Also in the case of this example, as in the case of the first example of the above-described embodiment, each of the bridge circuits 5a and 5b includes a bridge section 22 in which the four impedance sections 18 to 21 are arranged on four sides, and a bridge section. An oscillator 23 for applying an AC voltage to both ends of the bridge unit 22 and a lock-in amplifier 24 for detecting and amplifying a midpoint potential difference of the bridge unit 22 to generate an output V are provided.

  Also, in the case of the present example, similarly to the case of the first example of the above-described embodiment, the oscillator 23 applies an AC voltage to both ends of the bridge section 22 to thereby apply the first to fourth impedance sections. 18 to 21 (the first to fourth detection coils 10a to 13a), when an alternating current is applied, the first detection coils 10a and 10a (second detection coils 11a and 11a, the third detection coils The directions of the currents flowing through the coils 12a, 12a and the fourth detection coils 13a, 13a) are as shown by arrows A and B in FIGS. 16A and 16D, or as shown by arrows B and C in FIG. ), The directions are opposite to each other as shown by arrows C and 2. For this reason, also in the case of this example, the winding direction of the conductive wire and the manner in which the detection coils adjacent in the circumferential direction are connected in series with respect to the first to fourth detection coils 10a to 13a are regulated. Also in the case of the present example, in the neutral state where the torque is not applied to the detected member 2a, the first to the second are set so that the bridge portion 22 is in an equilibrium state (a state in which the midpoint potential difference is 0). The configuration of the four impedance units 18 to 21 is regulated.

  Also in the case of the torque measuring device of the present example configured as described above, in use, by applying an AC voltage to both ends of the bridge section 22 by the oscillator 23 for each of the two bridge circuits 5a and 5b, A magnetic field is generated around the first to fourth detection coils 10a to 13a by passing an alternating current through the first to fourth impedance units 18 to 21 (the first to fourth detection coils 10a to 13a). . In this state, when the torque T is applied to the detected member 2a, the equilibrium state of the bridge portion 22 is broken according to the same principle as in the first example of the above-described embodiment, and the bridge portion 22 Is changed by an amount corresponding to the torque T. Therefore, by detecting and amplifying the midpoint potential difference by the lock-in amplifier 24, an output V corresponding to the torque T can be obtained.

  Further, also in the case of this example, two bridge circuits 5a and 5b for measuring the torque T applied to the detected member 2a are provided. Therefore, even if one of the bridge circuits 5a (5b) fails, the measurement of the torque T can be continued by the other bridge circuit 5b (5a). Also in the case of the present example, for example, the measurement error can be improved by taking the average of the measured values of the torque T by the two bridge circuits 5a and 5b.

[Seventh Example of Embodiment]
A seventh example of the embodiment of the present invention will be described with reference to FIGS.
In the case of this example, the total number of the coil layers constituting the detecting unit 4c of the torque measuring sensor 1c is four. Among these four coil layers (first and second coil layers 6d and 7d and first and second coil layers 6d and 7d), two of the coil layers located on the side closer to the detected portion 3b (radially inside). One coil layer group including coil layers (first and second coil layers 6d and 7d) and two coil layers (first and second coils) located farther (radially outward) from the detected portion 3b. The other coil layer group composed of the layers 6d and 7d) has the same configuration as that of the other coil layer group except that the radial distance (radial dimension) from the detected part 3b is different.
Also in the case of the present embodiment, one bridge circuit 5a (see FIG. 6A) is configured for the one coil layer group, and one bridge circuit 5a is configured for the other coil layer group. A bridge circuit 5b (see FIG. 6B) is configured.

  The first and second coil layers 6d and 7d constituting the two coil layer groups are arranged such that the first coil layer 6d and the second coil layer 7d are arranged in the radial direction from the side closer to the detected portion 3b (in the radial direction). Are arranged in a stacked state. The first coil layer 6d and the second coil layer 7d are formed separately on one side and the other side of a band-shaped flexible substrate (not shown), and are formed by rolling the flexible substrate into a cylindrical shape. , And have a cylindrical shape. An insulating layer (not shown) is provided between the second coil layer 7d of the one coil layer group and the first coil layer 6d of the other coil layer group.

  FIG. 18 is a development view of the two coil layer groups as viewed from the outside in the radial direction. FIGS. 19A and 19B show the outer sides in the radial direction of the first and second coil layers 6d and 7d. FIG.

  In the case of this example, the first coil layer 6d is configured by arranging the first detection coils 10a and 10a and the fourth detection coils 13a and 13a alternately one by one in the circumferential direction and at equal pitches. Have been. The first detection coils 10a and 10a are adjacent to each other in the circumferential direction (however, a pair of first detection coils 10a and 10a adjacent to each other across both ends of the flexible substrate is excluded. ) Are connected in series to form the first impedance section 18 of the bridge circuit 5a (5b). Further, the fourth detection coils 13a, 13a are adjacent to each other in the circumferential direction (however, a pair of fourth detection coils 13a, 13a adjacent to each other across both ends of the flexible substrate is excluded. ) Are connected in series to form a fourth impedance section 21 constituting the bridge circuit 5a (5b). In FIGS. 18 and 19, the wiring (wiring structure including vias) for connecting the first detection coils 10a and 10a and the fourth detection coils 13a and 13a adjacent to each other in the circumferential direction is omitted.

  On the other hand, the second coil layer 7d is configured by arranging the second detection coils 11a, 11a and the third detection coils 12a, 12a alternately one by one in the circumferential direction and at equal pitches. ing. Also, the second detection coils 11a, 11a are adjacent to each other in the circumferential direction (however, a pair of second detection coils 11a, 11a adjacent to each other across both ends of the flexible substrate is excluded. ) Are connected in series to form a second impedance section 19 that forms the bridge circuit 5a (5b). The third detection coils 12a, 12a are adjacent to each other in the circumferential direction (however, a pair of third detection coils 12a, 12a adjacent to each other across both ends of the flexible substrate is excluded. ) Are connected in series to form a third impedance unit 20 that forms the bridge circuit 5a (5b). In FIGS. 18 and 19, the wiring (wiring structure including vias) connecting the second detection coils 11a and 11a and the third detection coils 12a and 12a adjacent to each other in the circumferential direction is omitted.

  Note that the total number of the first and fourth detection coils 10a and 13a constituting the first coil layer 6d and the total number of the second and third detection coils 11a and 12a constituting the second coil layer 7d are mutually different. Equal. Further, in the case of the present example, the phase of the arrangement of the first and fourth detection coils 10a and 13a constituting the first coil layer 6d in the circumferential direction and the second phase constituting the second coil layer 7d. The phases of the arrangement of the second and third detection coils 11a and 12a in the circumferential direction are matched with each other.

In the case of the torque measuring sensor 1c of the present example having such a configuration as well, since the two bridge circuits 5a and 5b for measuring the torque T applied to the detected member 2a are provided, either one of them is used. Even when the bridge circuit 5a (5b) fails, the measurement of the torque T can be continued by the other bridge circuit 5b (5a).
Further, in the case of this example, the number of coil layers for forming one bridge circuit 5a (5b) is two instead of four, so that the detection unit 4c is made thinner and the manufacturing cost is reduced. Is easy to reduce.
Other configurations and operations are the same as those in the first, second, and sixth embodiments.

[Eighth Example of Embodiment]
An eighth example of the embodiment of the present invention will be described with reference to FIG.
In the case of the torque measuring sensor according to the present embodiment, the first coil layer 6e and the second coil layer constitute a pair of coil layer groups for constituting a pair of bridge circuits 5a and 5b (see FIG. 6). The configuration of 7e (the manner of arranging each detection coil) is different from that of the seventh example of the above-described embodiment.

  In the case of the present example, the first coil layer 6e is located at one of the semi-cylindrical ranges divided into two equal halves in the circumferential direction, which is located in the upper half of FIG. Each of the first detection coils 10a and 10a is arranged in a circle, and each of the fourth detection coils 13a and 13a is arranged in a circle in the other semi-cylindrical area {the area located in the lower half of FIG. It is constituted by arranging in the direction. Further, when measuring the torque, of the first detection coils 10a and 10a and the fourth detection coils 13a and 13a constituting the first coil layer 6e, the two detection coils adjacent to each other in the circumferential direction flow. The directions of the currents are opposite to each other as shown by arrows A and B in FIG. For this reason, regarding the first and fourth detection coils 10a and 13a, the winding direction of the conducting wire and the first detection coils 10a and 10a adjacent to each other in the circumferential direction and the second detection coils 13a and 13a Regulates how to connect in series.

  Further, in the case of the present example, the second coil layer 7e is one half of the pair of semi-cylindrical regions divided in the circumferential direction into two semi-cylindrical regions {the upper half of FIG. And the third detection coils 12a and 12a in the other semi-cylindrical range {the range located in the lower half of FIG. 20B}. It is constituted by arranging in the circumferential direction. Also, when measuring the torque, of the second detection coils 11a, 11a and the third detection coils 12a, 12a constituting the second coil layer 7e, two of the detection coils adjacent to each other in the circumferential direction flow. The directions of the currents are opposite to each other as shown by arrows C and D in FIG. For this reason, regarding the second and third detection coils 11a and 12a, the winding direction of the conductive wire and the second detection coils 11a and 11a adjacent to each other in the circumferential direction and the third detection coils 12a and 12a Regulates how to connect in series.

As described above, in the case of the structure of the present example, the first coil layer 6e (second coil layer 7e) is divided into a pair of semi-cylindrical regions divided in the circumferential direction into two. The first detection coils 10a and 10a and the third detection coils 13a and 13a (the second detection coils 11a and 11a and the third detection coils 12a and 12a) are located in a cylindrical area, respectively. They are arranged side by side in the circumferential direction. Therefore, a wiring structure that connects the first detection coils 10a and 10a in series and a wiring structure that connects the fourth detection coils 13a and 13a in series (the second detection coils 11a and 11a The wiring structure connected in series and the wiring structure connecting the third detection coils 12a, 12a in series can be simplified. Therefore, it is easy to achieve downsizing by simplifying each of these wiring structures.
Other configurations and operations are the same as in the case of the seventh example of the above-described embodiment.

[Ninth Example of Embodiment]
A ninth embodiment of the present invention will be described with reference to FIG.
This example shows a specific usage of the torque measuring sensors 1b (1c) of the sixth to eighth examples of the above-described embodiment.
In the usage mode of this example, an annular drive plate 29b made of an iron-based alloy having magnetostrictive characteristics and connecting a crankshaft 26 of the engine 25 and a case 28 forming an outer shell of the torque converter 27 so as to transmit torque is provided. As a member to be detected, the torque applied to the drive plate 29b is measured by the torque measuring sensor 1b (1c). For this reason, the outer peripheral surface of the cylindrical portion 36a provided near the radial inner end of the drive plate 29b is defined as the detected portion 3c. The torque measuring sensor 1b (1c) is connected to the engine 25 in a state where the detecting section 4b (4c) of the torque measuring sensor 1b (1c) is radially opposed to the detected section 3c. It is supported and fixed to the cylinder block 30.

[Tenth Example of Embodiment]
A tenth example of an embodiment of the present invention will be described with reference to FIG.
This example also shows a specific usage of the torque measuring sensors 1b (1c) of the sixth to eighth examples of the above-described embodiment.
In the case of this example, the torque measuring sensor 1b (1c) radially opposed to the detected portion 3c of the drive plate 29b constitutes a sensor-equipped bearing by being combined with the rolling bearing 31. .
The rolling bearing 31 includes an outer ring 32 that is a stationary wheel that does not rotate during use, an inner ring 33 that is a rotating wheel that rotates during use, an outer ring raceway formed on an inner peripheral surface of the outer ring 32, and an outer periphery of the inner ring 33. A plurality of rolling elements (balls in the illustrated example) 34 are provided so as to roll freely between the inner raceway formed on the surface. Then, the outer ring 32 is fitted and fixed in a holding recess 35a provided in the cylinder block 30, and the inner ring 33 is fixed to the base end of the cylindrical portion 36a of the drive plate 29b (the right end in FIG. 20). The drive plate 29b is rotatably supported with respect to the cylinder block 30 by being externally fitted and fixed to an adjacent portion on the base end side.
The torque measuring sensor 1b (1c) is supported and fixed to one axial end (the left end in FIG. 22) of the outer race 32 via an annular holder 37a.
Other configurations and operations are the same as those of the ninth example of the above-described embodiment.

When the torque measuring sensor of the present invention is used by being incorporated in a power train of an automobile, the target device is not particularly limited. For example, an automatic transmission (AT), a belt-type continuously variable transmission, a toroidal-type continuously variable transmission, an automatic manual transmission (AMT), a double clutch transmission (DCT), and other transmissions that perform gear shifting by vehicle-side control, or a transfer. Can be targeted. Further, the drive system (FF, FR, etc.) of the target vehicle is not particularly limited.
Further, the torque measuring sensor of the present invention is used not only in a power train of an automobile but also incorporated in various mechanical devices such as a windmill, a railway vehicle, a rolling mill, a machine tool, a construction machine, an agricultural machine, a household electric appliance, and the like. Can do things.
Further, the bearing constituting the bearing with the sensor of the present invention is not limited to a rolling bearing, but may be a sliding bearing. Various types of rolling bearings such as needle bearings, deep groove ball bearings, angular ball bearings, tapered roller bearings, cylindrical roller bearings, and self-aligning roller bearings can be used. Further, the rolling bearing is not limited to a single-row rolling bearing, but may be a double-row rolling bearing.
Further, when the present invention is implemented, the detected portion provided on the axial side surface or the peripheral surface of the detected member is the axial side surface or the peripheral surface itself of the detected member, and further, on the axial side surface or the peripheral surface. A fixed magnetostrictive material can also be used.

1, 1a, 1b, 1c Torque measurement sensor 2, 2a Detected member 3, 3a, 3b, 3c Detected portion 4, 4a, 4b, 4c Detected portion 5a, 5b Bridge circuit 6, 6a, 6b, 6c, 6d , 6e First coil layer 7, 7a, 7b, 7c, 7d, 7e Second coil layer 8, 8c Third coil layer 9, 9c Fourth coil layer 10, 10a First detection coil 11, 11a Second detection coil 12 , 12a Third detection coil 13, 13a Fourth detection coil 14a, 14b, 14c, 14d Radial side 15a, 15b, 15c, 15d Radial side 16a, 16b, 16c, 16d Circumferential side 17a, 17b, 17c, 17d Circumferential side portion 18 First impedance portion 19 Second impedance portion 20 Third impedance portion 21 Fourth impedance portion 22 Ridge part 23 Oscillator 24 Lock-in amplifier 25 Engine 26 Crankshaft 27 Torque converter 28 Case 29, 29a, 29b Drive plate 30 Cylinder block 31 Rolling bearing 32 Outer ring 33 Inner ring 34 Rolling element 35, 35a Holding recessed part 36, 36a Cylindrical part 37, 37a holder 38 magnetic core 39 magnetic core element 40a, 40b, 40c, 40d circumferential side

Claims (3)

A plurality of coil layers are provided on the detected member to which the torque is applied, and are opposed to the detected portion that changes the magnetic permeability by applying a torsional stress according to the torque,
The coil layers are stacked and arranged in a direction facing the detection target portion,
Each of the coil layers includes a plurality of detection coils,
A bridge circuit in which four impedance portions, each of which is a part of each of the detection coils constituting each of the coil layers, are arranged on four sides; and a remaining detection coil among the detection coils constituting each of the coil layers And a bridge circuit in which four impedance units are arranged on four sides.
Each of the bridge circuits generates a midpoint potential difference corresponding to a torque applied to the detected member when an AC voltage is applied.
A torque measuring sensor,
The total number of the coil layers is eight,
The impedance unit is configured one for each coil layer,
Sensor for measuring torque. A plurality of coil layers are provided on the detected member to which the torque is applied, facing a detected portion that changes the magnetic permeability by applying a torsional stress according to the torque,
The coil layers are stacked and arranged in a direction facing the detection target portion,
Wherein each of the coil layers includes a plurality of detection coils that are arranged along the circumferential direction of the detected member,
A bridge circuit in which four impedance portions, each of which is a part of each of the detection coils constituting each of the coil layers, are arranged on four sides; and a remaining detection coil among each of the detection coils constituting each of the coil layers And a bridge circuit in which four impedance units are arranged on four sides.
Each of the bridge circuits generates a midpoint potential difference corresponding to a torque applied to the detected member when an AC voltage is applied.
A torque measuring sensor,
The total number of the coil layers is four,
The impedance unit is configured two by two for each coil layer,
Sensor for measuring torque. Bearings,
A sensor-equipped bearing, comprising: the torque measurement sensor according to claim 1, which is supported on a portion of the bearing that does not rotate during use.

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