Torque measurement device, magnetic field generation device for torque measurement device, and magnetic field detection device for torque measurement device

Abstract

To provide a torque measurement device that can achieve further miniaturization in comparison with a conventional device.SOLUTION: A torque measurement device 100 of the present invention comprises: a drive-side flange 110; a follower-side flange 120; a strain body 130 that is integrally provided between the drive-side flange 110 and the follower-side flange 120; a magnet 161 that is provided in a prescribed position of a peripheral-side face on an outer peripheral side in the follower-side flange 120; an annular multipolar magnetic ring 140 that is integrally attached to a disc-like edge face in the follower-side flange 120; and a detection device 300 that includes a first detection element 162 detecting a first magnetic field in which the magnet 161 is generated during rotation of the follower-side flange 120, and a second detection element 170 detecting a second magnetic field that arises during rotation of the multipolar magnetic ring 140 rotating with the follower-side flange 120. The first detection element 162 is configured to output a signal representing the follower-side flange 120 having rotated once when a sum of the first magnetic field and the second magnetic field exceeds a prescribed threshold.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a torque measuring device, a magnetic field generating device for a torque measuring device, and a magnetic field detecting device for a torque measuring device.

Background Art

[0002] Conventionally, in a torque measuring device, it is provided on a rotating shaft between a rotating body and a load, and measures the rotational torque between the rotating body and the load non-contactingly. For example, in a drive shaft that serves to transmit the power of an automobile engine to wheels, a shaft torque measuring device that measures the shaft torque has been proposed (see, for example, Patent Document 1).

[0003] In this shaft torque measuring device, the rotation direction is discriminated by A-phase and B-phase signals detected by two magnetic sensors such as Hall elements arranged so as to face the periphery of a ring-shaped magnetic encoder, and the twist direction and twist amount of the drive shaft are measured from the difference between the signals of both the A-phase and B-phase, and the shaft torque is calculated from the twist amount.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the shaft torque measuring device of Patent Document 1, in order to detect the rotational speed and rotational angle from the A-phase and B-phase signals, a configuration using two rotation detectors each including an angular sensor target and a sensor-side unit is adopted. In such a shaft torque measuring device, since it has a configuration using two rotation detectors, it is likely to be enlarged as a whole, and there has been a desire to further miniaturize it conventionally.

[0006] The present invention has been made in view of the above background, and an object thereof is to provide a torque measuring device that can be further miniaturized compared to the prior art.

Means for Solving the Problems

[0007] The above problems are solved by the following present invention. That is, the torque measuring device of the present invention includes a drive-side flange, a driven-side flange, and a strain generating body that is integrally provided between the drive-side flange and the driven-side flange and on the same axis as both the drive-side flange and the driven-side flange, and to which a strain gauge is attached, a magnet provided at a predetermined position on the circumferential side surface on the outer peripheral side of the driven-side flange, an annular multi-pole magnetic ring integrally attached to the disk-shaped end surface of the driven-side flange, a first detection element that detects a first magnetic field generated by the magnet during rotation of the driven-side flange, and a second detection element that detects a second magnetic field generated by the multi-pole magnetic ring during rotation of the multi-pole magnetic ring that rotates together with the driven-side flange. The detection device includes a first detection element that outputs a signal indicating that the driven-side flange has made one rotation when the sum of the first magnetic field and the second magnetic field exceeds a predetermined threshold value.

[0008] The magnetic field generating device for the torque measuring device of the present invention includes a drive-side flange, a driven-side flange, a strain generating body that is integrally provided between the drive-side flange and the driven-side flange and on the same axis as both the drive-side flange and the driven-side flange, a magnet that is arranged to face the detection device and that generates a magnetic field at a predetermined position on the circumferential side surface on the outer peripheral side of the driven-side flange, and an annular multi-pole magnetic ring that is integrally attached to the disk-shaped end surface of the driven-side flange and that generates a magnetic field.

[0009] The magnetic field detection device for the torque measurement device of the present invention includes a first detection element that detects the magnetic field generated by a magnet during the rotation of the driven-side flange, and a second detection element that detects the magnetic field generated by a multi-pole magnetic ring that rotates together with the driven-side flange during the rotation of the multi-pole magnetic ring. The first detection element outputs a signal indicating that the driven-side flange has made one full rotation when the sum of the magnetic field generated by the magnet and the magnetic field generated by the multi-pole magnetic ring exceeds a predetermined threshold value.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0011] <Embodiment> Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of a torque measuring device according to an embodiment of the present invention. FIG. 2 is a schematic front view showing the arrangement of a magnet of a Hall sensor, a Hall element, a TMR element, and a multi-pole magnetic ring in the torque measuring device according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing the configuration of a multi-pole magnetic ring used in the torque measuring device according to an embodiment of the present invention. FIG. 4 is a pulse waveform diagram showing the A-phase, B-phase, and Z-phase pulses detected by the torque measuring device according to an embodiment of the present invention. FIG. 5 is a waveform diagram showing the relationship between the strength (A) of the magnetic field generated by the multi-pole magnetic ring of the torque measuring device according to an embodiment of the present invention, the strength (B) of the magnetic field generated by the magnet of the Hall sensor, and the sum of the strengths of the magnetic fields generated by the multi-pole magnetic ring and the magnet of the Hall sensor and the threshold value, respectively.

[0012] In the description of the present embodiment, in the following description, for convenience, the direction in which the axis X of the torque measuring device 100 extends is referred to as the rotation axis X direction or the axis X direction. Also, in the following description, for convenience, in the rotation axis X direction, the arrow a direction is the driving side or the left side, and the arrow b direction is the driven side or the right side. In the radial direction perpendicular to the axis X, the arrow c direction away from the axis X is the outer peripheral side, and the arrow d direction approaching the axis X is the inner peripheral side. Further, in the torque measuring device 100, the upper side (arrow e direction) and the lower side (arrow f direction) mean the vertical relationship in the gravitational direction of the torque measuring device 100 on the drawing.

[0013] As shown in FIGS. 1 and 2, the torque measuring device 100 includes a driving side flange 110, a driven side flange 120, and a hollow cylindrical strain generating body 130 having a predetermined thickness and a predetermined outer diameter between the driving side flange 110 and the driven side flange 120. However, in FIG. 1, the strain generating body 130 is in a state of being hidden between the driving side flange 110 and the driven side flange 120.

[0014] The driving-side flange 110 is a disc-shaped member. A plurality of screw holes 112 are provided at equal intervals on concentric circles while penetrating through the driving-side flange 110.

[0015] In the driving-side flange 110, on the end face 110s on the left side (in the direction of arrow a) of the driving-side flange 110 in the figure, for example, a driving-side connecting member (not shown) connected to a measurement roller of a chassis dynamo rotated by a vehicle wheel, a dynamometer, a brake mechanism, etc. is connected via a plurality of screw holes 112.

[0016] Also, the circumferential side surface of the driving-side flange 110 is covered by a cover body 152 having an annular half-divided structure provided on the fixed base 150. Note that the cover body 152 does not cover the end face 110s of the driving-side flange 110 and is exposed. The cover body 152 is fixed to the fixed base 150 by screws or the like (not shown).

[0017] The driven-side flange 120 is a disc-shaped member having the same outer diameter as the driving-side flange 110. The driving-side flange 110 and the driven-side flange 120 are integrally formed via a strain generating body 130 provided between them. That is, the driving-side flange 110, the strain generating body 130, and the driven-side flange 120 are integrated around the axis X. Note that, unlike the driving-side flange 110, the driven-side flange 120 is not covered by the cover body 152 and is in a state of being completely exposed on the upper side (in the direction of arrow e) of the fixed base 150.

[0018] Also in the driven-side flange 120, a plurality of screw holes 122 are provided at equal intervals on concentric circles while penetrating through the driven-side flange 120. The driven-side flange 120 is connected to a load member (not shown) via a plurality of screw holes 122.

[0019] The driven-side flange 120 has a plurality of bottomed holes (hereinafter simply referred to as "holes") 124 formed at regular intervals with respect to the circumferential side surface (hereinafter referred to as the "circumferential side surface") 120a. Inside the plurality of holes 124 in the driven-side flange 120, light-emitting elements (not shown) such as light-emitting diodes constituting a light sensor (not shown) are respectively embedded.

[0020] At a predetermined position of the fixed base 150 facing the circumferential side surface 120a of the driven-side flange 120 having the holes 124 in which the light-emitting elements of the light sensor are embedded, a detection unit 300 as a magnetic field detection device is attached.

[0021] In the detection unit 300, a light-receiving element such as a photodiode for receiving the light output from the light-emitting element of the above-described light sensor is provided. This light sensor transmits the signal detected by a strain gauge (described later) attached to the strain body 130 between the light-emitting element of the driven-side flange 120 and the light-receiving element of the detection unit 300 in a non-contact manner.

[0022] In any one of the plurality of holes 124 provided in the circumferential side surface 120a of the driven-side flange 120, a magnet 161 constituting the Hall sensor 160 is embedded together with the above-described light-emitting element (not shown) of the light sensor. That is, any one of the plurality of holes 124 in the driven-side flange 120 is shared by both the light-emitting element and the magnet 161 of the Hall sensor 160.

[0023] The magnet 161 of the Hall sensor 160 is provided at a position that serves as a mechanical origin for outputting a Z-phase signal when the driven-side flange 120 makes one rotation (one revolution). This is for detecting the rotational position of a rotating shaft (not shown) such as a shaft as a load member connected to the driven-side flange 120 in the torque measuring device 100.

[0024] This Hall sensor 160 is configured to be non-contact by a magnet 161 provided on the driven-side flange 120 and a Hall element 162 provided on the detection unit 300. The Hall sensor 160 is a magnetic sensor that uses the Hall effect to convert the first magnetic field generated by the magnet 161 or the first magnetic field generated by the current into an electrical signal by the Hall element 162 as the first detection element and outputs it.

[0025] Further, on the driven-side flange 120, an annular multi-pole magnetic ring 140 having substantially the same outer diameter as the driven-side flange 120 is integrally attached to the end face 120b on the right side (in the direction of arrow b) where a plurality of screw holes 122 are formed.

[0026] That is, since the driven-side flange 120 and the multi-pole magnetic ring 140 are in an integrated state, the multi-pole magnetic ring 140 rotates simultaneously with the drive-side flange 110 and the driven-side flange 120. Note that the outer diameter of the multi-pole magnetic ring 140 may be larger or smaller than the outer diameter of the driven-side flange 120.

[0027] The multi-pole magnetic ring 140 is a magnetic ring made of a thin plate and an annular ring member, and is a plastic magnetic ring that is lightweight so as not to be a load during high-speed rotation with respect to the integrally attached driven-side flange 120.

[0028] As shown in FIG. 3, the multi-pole magnetic ring 140 is an axial-type magnetic ring composed of a total of 16 poles (sets) in which a set of S poles and N poles are magnetized at equal intervals along the circumferential direction on its end face 140s. Note that the multi-pole magnetic ring 140 does not have to be limited to 16 poles, and may have 8 poles, 24 poles, or more poles, and the number of poles may be set according to the required rotational resolution.

[0029] The strain generating body 130 is a hollow cylindrical member located between the drive-side flange 110 and the driven-side flange 120 and integrally formed with both. A plurality of strain gauges (not shown) are attached to the inner peripheral surface of the strain generating body 130. The plurality of strain gauges are connected so as to form a Wheatstone bridge circuit.

[0030] Incidentally, in the torque measuring device 100, the drive-side flange 110, the driven-side flange 120, and the strain generating body 130 formed therebetween need to receive power from the outside when measuring the torque amount. Therefore, in the torque measuring device 100, for example, power transmission is performed non-contact from the outside in the form of a rotary transformer.

[0031] By the way, in the torque measuring device 100, the detection unit 300 is arranged so as to face the circumferential side surface 120a of the driven-side flange 120. In the detection unit 300, a Hall element 162 is attached at a position facing the magnet 161 of the Hall sensor 160 embedded in the hole 124 of the circumferential side surface 120a of the driven-side flange 120. In practice, the light receiving element of the optical sensor and the Hall element 162 of the Hall sensor 160 are attached to the circuit board 180 of the detection unit 300.

[0032] Furthermore, in the detection unit 300, a TMR (Tunneling Magneto Resistance) element 170, which is a second detection element that detects the magnetic field (second magnetic field) of the multi-pole magnetic ring 140 and outputs an A-phase signal and a B-phase signal, is also attached at a position on the circuit board 180 facing the multi-pole magnetic ring 140.

[0033] The TMR element 170 is a tunnel magnetoresistance effect element that utilizes the tunnel magnetoresistance effect. In fact, when the multi-pole magnetic ring 140 rotates together with the driven-side flange 120, the direction of the magnetic field acting on the TMR element 170 rotates according to the rotation, and an A-phase signal and a B-phase signal with a phase shift from each other are output.

[0034] Actually, as shown in FIG. 4, the phase of the B-phase signal is shifted by 90 degrees with respect to the A-phase signal output by the TMR element 170. For example, when the driven-side flange 120 rotates in the clockwise direction, the A-phase signal is output with a phase advanced by 90 degrees compared to the B-phase signal, and when the driven-side flange 120 rotates in the counterclockwise direction, the A-phase signal is output with a phase lagged by 90 degrees compared to the B-phase signal.

[0035] Incidentally, the Hall element 162 of the Hall sensor 160 detects the magnetic field of the magnet 161 when it faces the magnet 161 when the driven-side flange 120 rotates, and outputs a Z-phase signal once per rotation (one revolution) of the driven-side flange 120.

[0036] Note that it is necessary to align the magnet 161 embedded in the hole 124 on the circumferential side surface 120a of the driven-side flange 120 with the position (polarity) of the multi-pole magnetic ring 140. For example, the driven-side flange 120 and the multi-pole magnetic ring 140 are integrally attached so that the peak of the magnetic field of the S pole in the magnet 161 coincides with the peak of the magnetic field of the S pole of the multi-pole magnetic ring 140.

[0037] Specifically, on the end face 140s (FIG. 2) of the multi-pole magnetic ring 140 facing the driven-side flange 120 at an arbitrary position, a columnar convex portion 142 (FIG. 3) protruding to the left (in the direction of arrow a) is formed. Also, on the side 120b of the driven-side flange 120 facing the multi-pole magnetic ring 140, there is a concave portion which is a columnar hole fitted with the above-mentioned convex portion 142. End face 120b is formed with a concave portion which is a columnar hole fitted with the above-mentioned convex portion 142. 123 is formed.

[0038] Therefore, in a state where the convex portion 142 of the multi-pole magnetic ring 140 and the concave portion of the driven-side flange 120 are fitted, it is preset so that the peak of the magnetic field of the S pole in the magnet 161 of the Hall element coincides with the peak of the magnetic field of the S pole of the multi-pole magnetic ring 140. For example, as shown in FIG. 2, in the axial direction X of the driven-side flange 120, the Hall element 123 and the peak of the magnetic field of the S pole of the multi-pole magnetic ring 140 coincide. For example, as shown in FIG. 2, in the axial direction X of the driven-side flange 120, the Hall element 162 is preset so that the peak of the magnetic field of the S pole in the magnet 161 of the Hall element coincides with the peak of the magnetic field of the S pole of the multi-pole magnetic ring 140. For example, as shown in FIG. 2, in the axial direction X of the driven-side flange 120, the Hall element 162The magnet 161 and the S pole of the multi-pole magnetic ring 140 are arranged adjacent to each other. In the torque measuring device 100, a magnetic field generating device for the torque measuring device is constituted by the driven side flange 120, the magnet 161, and the multi-pole magnetic ring 140.

[0039] In the detection unit 300, not limited to the TMR element 170, as long as it is a magnetoresistive effect element, a DMR (Double Magneto Resistance) element, a GMR (Giant Magneto Resistive effect) element, an AMR (Anisotropic Magneto Resistive) element, etc. may be used. Incidentally, the TMR element 170 is also attached to the circuit board of the detection unit 300.

[0040] As shown in FIG. 3, the TMR element 170 is an element capable of outputting 256 pulses with respect to the angle from a set of S poles to N poles (in this case, 22.5 degrees (360÷16 = 22.5)) among the 16 poles of the multi-pole magnetic ring 140.

[0041] Therefore, as shown in FIG. 4, when the driven side flange 120 (multi-pole magnetic ring 140) makes one rotation (one revolution), one pulse of the Z-phase signal is output from the Hall element 162, while 4096 (256×16) pulses are output from the TMR element 170 as the A-phase and B-phase signals.

[0042] Since the TMR element 170 outputs 4096 pulses per one rotation of the driven side flange 120, an arithmetic processing unit (not shown) mounted on the circuit board 180 of the detection unit 300 can obtain the rotation speed (rpm) of the driven side flange 120, that is, the rotation speed, based on the number of pulses per unit time.

[0043] Also, as shown in FIG. 4, the phase of the signal of phase A or phase B output from the TMR element 170 will advance or lag according to the rotation direction of the driven-side flange 120. Therefore, in the arithmetic processing unit of the circuit board 180, the rotation direction of the driven-side flange 120 can also be determined based on the phases of phase A and phase B output from the TMR element 170.

[0044] In the detection unit 300, the Hall element 162 and the TMR element 170 are arranged in parallel at positions on the circuit board 180 facing the magnet 161 and the multi-pole magnetic ring 140 of the driven-side flange 120, respectively. This detection unit 300 serves as a magnetic field detection device for the torque measurement device.

[0045] That is, in the detection unit 300, the Hall element 162 of the Hall sensor 160 and the TMR element 170 for detecting the magnetic field of the multi-pole magnetic ring 140 are provided in parallel at positions close to each other. Therefore, in the detection unit 300, it contributes to space saving compared to the case where the Hall element 162 and the TMR element 170 are provided at positions far from each other, and miniaturization can be achieved.

[0046] By the way, in the torque measurement device 100, both the Hall element 162 and the TMR element 170 are mounted on the circuit board 180 of the detection unit 300 at positions close to each other, but the Hall element 162 and the TMR element 170 are arranged at a certain distance along the axis X direction so that the magnetic fields of the magnet 161 and the multi-pole magnetic ring 140 do not affect each other too much.

[0047] The Hall element 162 of the Hall sensor 160 detects the radial magnetic field in the magnet 161 embedded in the hole 124 on the circumferential side surface 120a of the driven-side flange 120. In contrast, the TMR element 170 detects the axial magnetic field in the multi-pole magnetic ring 140. That is, the Hall element 162 and the TMR element 170 have different directions for detecting the magnetic field.

[0048] As shown in FIG. 5(A), when the magnetic field of the multi-pole magnetic ring 140 is detected by the TMR element 170, the magnetic field strengths corresponding to the A-phase and B-phase are, for example, 2.0 mT (millitesla). On the other hand, as shown in FIG. 5(B), when only the magnetic field of the magnet 161 of the Hall sensor 160 is detected by the Hall element 162, the magnetic field strength corresponding to the Z-phase is 1.5 mT.

[0049] As described above, in the axial direction X of the driven-side flange 120, it is preset so that the peak of the magnetic field of the S-pole in the magnet 161 attached to the hole 124 of the circumferential side surface 120a coincides with the peak of the magnetic field of the S-pole of the multi-pole magnetic ring 140. For this reason, as shown in FIG. 5(C), the Hall element 162 detects a magnetic field of 3.5 mT in which the magnetic field strength of the magnet 161 (1.5 mT) and the magnetic field strength of the multi-pole magnetic ring 140 (2.0 mT) are superimposed.

[0050] Here, the Hall element 162 is configured to output a Z-phase signal when the detected magnetic field strength exceeds 3.0 mT set as a threshold value. That is, when the Hall element 162 detects the magnetic field of the magnet 161, even if it is affected by the magnetic field of the multi-pole magnetic ring 140, when it does not detect the magnetic field of the magnet 161, it does not detect a magnetic field of 2.0 mT or more from the multi-pole magnetic ring 140, so it does not exceed the threshold value of 3.0 mT and does not output a Z-phase signal.

[0051] Also, as described above, in the axial direction X of the driven-side flange 120, the peak of the magnetic field of the S-pole in the magnet 161 coincides with the peak of the magnetic field of the S-pole of the multi-pole magnetic ring 140. However, at the timing when the TMR element 170 detects only the magnetic field of the multi-pole magnetic ring 140, since it is not affected by the magnetic field of the magnet 161, it outputs only the signals of the A-phase and B-phase.

[0052] In this case, since the arithmetic processing unit on the circuit board 180 of the detection unit 300 is not affected by the magnetic field of the magnet 161 of the Hall sensor 160, the rotational speed and direction of rotation of the driven flange 120 can be accurately calculated based on the A-phase and B-phase signals output from the TMR element 170 that detects the magnetic field of the multi-pole magnetic ring 140.

[0053] If, hypothetically, the magnetic field of the magnet 161 of the Hall sensor 160 has a value that is very much stronger than 3.0 mT to the extent that the magnetic field of the multi-pole magnetic ring 140 can be ignored, and the threshold value is set high in accordance with the strong magnetic field of the magnet 161, the Hall element 162 can surely detect the Z-phase signal.

[0054] However, there is a risk that the strong magnetic field of the magnet 161 will have an adverse effect on the magnetic field of the multi-pole magnetic ring 140 and cause the TMR element 170 to malfunction. Therefore, in the torque measuring device 100, it is necessary to set the magnetic field of the magnet 161 of the Hall sensor 160 so that it is not too strong.

[0055] Also, consider the case where the magnetic field of the magnet 161 of the Hall sensor 160 is very weak compared to 1.5 mT, for example, 0.5 mT which is lower than 2.0 mT, which is the magnetic field strength of the multi-pole magnetic ring 140. In this case, the Hall element 162 will detect the superposition of the magnetic field strength of the magnet 161 (0.5 mT) and the magnetic field strength of the multi-pole magnetic ring 140 (2.0 mT), and the total magnetic field strength is 2.5 mT, which does not exceed the threshold value of 3.0mT Therefore, if the threshold value is lowered from 3.0 mT to a value close to 2.0 mT, the Hall element 162 may output a Z-phase signal based on the magnetic field strength (2.0 mT) of the multi-pole magnetic ring 140 even when it is not detecting the magnetic field of the magnet 161.

[0056] That is, based on parameters such as the strength of the magnetic field of the magnet 161 of the Hall sensor 160, the strength of the magnetic field of the multi-pole magnetic ring 140, and the distance between the Hall element 162 and the TMR element 170 in the detection unit 300, it is important to set an appropriate magnetic field strength and distance, and to set a threshold value at which the Hall element 162 does not malfunction.

[0057] <Function and Effect> In the above configuration, in the torque measuring device 100, since the driven-side flange 120 and the multi-pole magnetic ring 140 are integrally attached, it is possible to reduce the size and make it more compact compared to the case where the multi-pole magnetic ring 140 is provided separately from the driven-side flange 120.

[0058] Further, in the torque measuring device 100, the Hall element 162 disposed opposite to the magnet 161 attached to the hole 124 on the circumferential side surface 120a of the driven-side flange 120 and the TMR element 170 disposed opposite to the multi-pole magnetic ring 140 are provided in a state parallel to the circuit board 180 of the detection unit 300. Therefore, the torque measuring device 100 can be made smaller and more compact as a whole without increasing the size of the detection unit 300.

[0059] In the detection unit 300, since the Hall element 162 and the TMR element 170 are disposed at positions close to each other on the circuit board 180, the Hall element 162 detects the magnetic field of the multi-pole magnetic ring 140, and the TMR element 170 detects the magnetic field of the magnet 161.

[0060] However, for the Hall element 162 of the detection unit 300, the maximum strength of the magnetic field of the magnet 161 is 1.5 mT, and the maximum strength of the magnetic field of the multi-pole magnetic ring 140 is 2.0 mT. Therefore, the sum of the magnetic fields of the two is 3.5 mT, which is the sum of the magnetic force vectors according to the superposition principle. Also, as a reference for outputting the Z-phase signal, the Hall element 162 is set to 3.0 mT as a threshold value to ensure that the Z-phase signal is output without error when detecting 3.5 mT, taking safety into consideration.

[0061] As a result, the Hall element 162 can output a Z-phase signal only when detecting the magnetic field of the multi-pole magnetic ring 140 and at the same time detecting the magnetic field of the magnet 161. Thus, the arithmetic processing circuit provided on the circuit board 180 of the detection unit 300 can also calculate the rotational position of the driven-side flange 120 based on the Z-phase signal.

[0062] In addition, since only one magnet 161 of the driven-side flange 120 is attached to the TMR element 170 of the detection unit 300, when detecting the magnetic field of the multi-pole magnetic ring 140, the A-phase and B-phase signals can be output in the portion where the magnetic field of the magnet 161 is not detected. As a result, the arithmetic processing circuit provided on the circuit board 180 of the detection unit 300 can accurately obtain the rotational speed and rotational direction of the driven-side flange 120.

[0063] According to the above configuration, it is possible to provide a torque measurement device 100 that is further miniaturized compared to the conventional one, and it is possible to obtain the rotational position of the driven-side flange 120 as well as the rotational speed and rotational direction of the driven-side flange 120.

[0064] <Other Embodiments> In the torque measurement device 100 of the present embodiment, the case where the axial type multi-pole magnetic ring 140 is used has been described. However, the present invention is not limited to this, and a radial type multi-pole magnetic ring may be used.

[0065] As described above, the torque measurement device of the present invention has been described with reference to the preferred embodiments. However, the torque measurement device of the present invention is not limited to the configuration of the above embodiments. In addition, those skilled in the art can appropriately modify the torque measurement device of the present invention in accordance with the conventionally known knowledge. As long as the configuration of the present invention is still provided by such modifications, of course, it is included in the scope of the present invention.

Explanation of Reference Numerals

[0066] 100…Torque measuring device, 110…Drive-side flange, 120…Driven-side flange, 130…Strain body, 140…Multi-pole magnetic ring, 150…Fixed base, 160…Hall sensor, 161…Magnet, 162…Hall element, 170…TMR element, 180…Circuit board, 300…Detection unit.

Claims

1. A driving-side flange, a driven-side flange, a strain generating body provided integrally between the driving-side flange and the driven-side flange on the same axis as both the driving-side flange and the driven-side flange, with a strain gauge attached thereto, a magnet provided at a predetermined position on the circumferential side surface on the outer peripheral side of the driven-side flange, an annular multi-pole magnetic ring integrally attached to the disc-shaped end face of the driven-side flange, a detection device including a first detection element for detecting a first magnetic field generated by the magnet during rotation of the driven-side flange, and a second detection element for detecting a second magnetic field generated by the multi-pole magnetic ring during rotation of the multi-pole magnetic ring rotating together with the driven-side flange comprising, the first detection element outputs a signal indicating that the driven-side flange has made one rotation when the sum of the first magnetic field and the second magnetic field exceeds a predetermined threshold value a torque measuring device.

2. The first detection element is arranged to face the magnet, and the second detection element is arranged to face the multi-pole magnetic ring The torque measuring device according to Claim 1.

3. The first detection element and the second detection element are arranged in a parallel state along the axis in the detection device The torque measuring device according to Claim 2.

4. The driven-side flange and the multi-pole magnetic ring are integrally attached so that the peak of the first magnetic field coincides with the peak of the second magnetic field The torque measuring device according to Claim 1.

5. On the end face where the multi-pole magnetic ring is attached to the driven-side flange, a positioning convex portion is formed, On the end face where the driven-side flange is attached to the multi-pole magnetic ring, a concave portion engaged with the convex portion is formed The torque measuring device according to Claim 4.

6. The first detection element is a Hall element, The second detection element is a TMR element The torque measuring device according to any one of Claims 1 to 5.

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