JP2006090856A - Drive shaft monitor and its sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new technical means for monitoring a drive shaft by accurately detecting its running torque in operation at all times even on a drive shaft used for a rolling mill, etc. <P>SOLUTION: Magneto-resistance change members 12c, whose magneto-resistance is changed by their distortion in synchronization with the running torque of the drive shaft, are provided on an intermediate flange (part under detection) 1 installed on the drive shaft 50. Further, the intermediate flange 1 is provided with an excitation part which is disposed opposite thereto and equipped with excitation surfaces 7p and 8p for exciting the intermediate flange 1. A detection part is placed there, comprising detection surfaces 7q, 7r, 8q, and 8r disposed opposite to the intermediate flange 1, and forming a magnetic circuit, together with the part under detection and excitation part, on a portion on a peripheral surface of the drive shaft, to detect magnetic flux flowing through the magnetic circuit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive shaft monitoring device that monitors a drive shaft used in rolling equipment and the like, and a sensor device used in the monitoring device.

For example, in a rolling mill for steel, a drive shaft whose one end side is connected to the output shaft side of a drive motor is provided, and this drive shaft rotates a rolling roller connected to the other end side, thereby rolling the steel material. Has been implemented. In such a rolling facility, when the drive shaft rotates abnormally, the quality of the steel material during the rolling process is greatly deteriorated. Therefore, it is desired to constantly monitor the rotational torque of the drive shaft.
On the other hand, for drive shafts incorporated in prime movers, machine tools, etc., in order to control the drive, it has been proposed to detect the rotational torque of the drive shaft using a torque detector using a magnetostrictive sensor or strain gauge. ing. In such a conventional torque detection device, as described in Patent Document 1 below, for example, a magnetostrictive material layer as a detected portion having a “C” -shaped pattern is provided on the outer peripheral surface of the drive shaft. There is a sensor that detects torque by measuring a change in magnetic permeability of the magnetostrictive material layer that changes in accordance with rotational torque by the magnetostrictive sensor. Further, as described in Non-Patent Document 1 below, in the conventional device, the detection portion including the strain gauge is formed in a flange shape, and this flange-shaped detection portion is incorporated in the middle portion of the drive shaft. There is one that detects rotational torque. Therefore, it is conceivable to use such a conventional apparatus for the drive shaft of the rolling equipment.

JP 2000-9558 (pages 4-5, FIG. 3) Nikkan Kogyo Shimbun, Japan, Nikkan Kogyo Shimbun, August 14, 2003, 6th page

By the way, in the conventional apparatus using the magnetostrictive sensor as described above, an annular excitation coil is provided outside the outer periphery of the drive shaft so as to surround the entire outer periphery of the drive shaft. An annular detection coil is arranged outside the outer periphery. And the excitation coil excited the said to-be-detected part, and the rotation torque of the drive shaft was detected by detecting the magnetic permeability in the to-be-detected part which a detection coil changes with a torque change.
However, in the rolling equipment, the two drive shafts are rotationally driven in a state where they are arranged close to each other, and each of these drive shafts has a small diameter of about 80 cm, which is the prime mover in the conventional apparatus. It is very difficult to place the excitation coil and the detection coil on the outside of the outer periphery of the drive shaft in two stages as described above. there were. Moreover, in such a large drive shaft, it is necessary to suspend the drive shaft by, for example, winding a wire around the outer peripheral surface of the drive shaft when performing the replacement operation or the like. When a heavy coil is wound, it may be necessary to move the drive motor connected to the end of the drive shaft. Therefore, it is practically impossible to apply this conventional apparatus. .

Further, in a conventional apparatus using a strain gauge, torque detection is performed by incorporating a detection unit including the gauge into the drive shaft and detecting distortion generated according to the rotational torque by the detection unit.
However, the drive shaft of rolling equipment is different from the drive shaft of a prime mover or the like, and a rotating torque of several tens (ton meter) works even during normal operation. During overload (abnormal) operation such as mis-rolling, Torque exceeding one hundred (ton meter) is applied. For this reason, the detection unit cannot cope with such a high torque in strength, and therefore, this conventional apparatus cannot be applied.
As described above, the drive shaft used in rolling equipment is large and transmits power with extremely high torque, so it is difficult to permanently install a torque sensor, etc. Rotational torque detection and monitoring of the drive shaft using this detection result could not be carried out.

  Accordingly, the present invention provides a new technical means capable of accurately and constantly detecting rotational torque during operation even in a drive shaft used in rolling equipment or the like and monitoring the drive shaft. With the goal.

The present invention is a drive shaft monitoring device for monitoring a drive shaft,
A detected portion that is provided on a flange installed on the drive shaft and is distorted in synchronization with the rotational torque of the drive shaft, and a magnetoresistive change, and a detected portion that is disposed opposite to the detected portion. A magnetic circuit on a part of the outer peripheral surface of the drive shaft together with the detected part and the excitation part. It comprises, and is provided with the detection part which detects the magnetic flux which flows through the said magnetic circuit.

Further, the sensor device of the present invention is a sensor device of a drive shaft monitoring device in which a detected portion whose magnetic resistance changes by being distorted in synchronization with the rotational torque of the drive shaft is provided on a flange installed on the drive shaft. There,
A part on the outer peripheral surface of the drive shaft having an exciting part having an exciting surface for exciting the detected part and a detecting surface arranged opposite to the detected part, together with the detected part and the exciting part And a detection unit configured to detect a magnetic flux flowing through the magnetic circuit.

  In the drive shaft monitoring device and the sensor device configured as described above, a detected portion whose magnetic resistance changes by being distorted in synchronization with the rotational torque of the drive shaft is provided on a flange installed on the drive shaft. ing. In addition, the excitation unit excites the detected part by the excitation surface, and the detection unit forms a magnetic circuit together with the detected part and the excitation unit, and detects the magnetic flux flowing through the magnetic circuit on the detection surface. As a result, when the magnetic resistance of the detected portion changes in synchronization with the rotational torque, the magnetic resistance of the magnetic circuit also changes in response to the torque change, and the magnetic flux flowing through the magnetic circuit also responds to the rotational torque change. Fluctuate. As a result, the magnetic flux passing through the detection surface varies, and the detection unit can detect the rotating magnetic flux by detecting the varying magnetic flux. Also, since the magnetic circuit is configured on a part of the outer peripheral surface of the drive shaft, unlike the conventional example using the magnetostrictive sensor, it is necessary to arrange the excitation coil and the detection coil so as to surround the entire outer periphery of the drive shaft. There is no. Furthermore, since the detection unit and the sensor device including the detection unit are provided independently of the detected unit, the detection unit is different from the conventional example using the strain gauge even when the rotational torque is very high torque. Magnetic flux fluctuations can be detected, and torque can be detected. Moreover, since the detected part is provided on the flange, the detected part can be easily attached to the existing drive shaft, and even when the monitored drive shaft is changed, it is possible to easily cope with it. It becomes.

The drive shaft monitoring device of the present invention is a drive shaft monitoring device that monitors the drive shaft,
Provided on the drive shaft and distorted in synchronism with the rotational torque of the drive shaft, the detected portion whose magnetic resistance changes, and the excitation that is disposed opposite to the detected portion and excites the detected portion An excitation unit having a surface, a detection surface disposed opposite to the detected portion, and a magnetic circuit formed on a part of the outer peripheral surface of the drive shaft together with the detected portion and the excitation portion; A detection unit for detecting a magnetic flux flowing through the magnetic circuit,
The detected part applies a compressive load that changes in synchronization with the rotational torque of the drive shaft to the magnetoresistive change member in which the easy magnetization direction of the easy magnetization axis is aligned in a predetermined direction. Thus, a compression load applying member that changes the easy magnetization direction of the magnetoresistive change member is provided.

  In the drive shaft monitoring apparatus configured as described above, the detected portion is installed on the drive shaft. In addition, the excitation unit and the detection unit constituting the magnetic circuit are provided independently on the detection unit together with the detection unit, and the detection unit is excited by the excitation surface of the excitation unit. And the magnetic flux which flows through the said magnetic circuit is detected in the detection surface of a detection part. As a result, when the magnetic resistance of the detected portion changes in synchronization with the rotational torque, the magnetic resistance of the magnetic circuit also changes in response to the torque change, and the magnetic flux flowing through the magnetic circuit also responds to the rotational torque change. Fluctuate. As a result, the magnetic flux passing through the detection surface varies, and the detection unit can detect the rotating magnetic flux by detecting the varying magnetic flux. Therefore, even when the rotational torque is extremely high, the torque can be detected without arranging the excitation coil and the detection coil so as to surround the entire outer peripheral surface of the drive shaft. Further, since the easy direction of magnetization of the magnetoresistive change member is aligned in a predetermined direction in the detected part, the change of the magnetic resistance according to the compressive load from the compressive load applying member can be maximized. The change in magnetic flux passing through the detection surface can be increased, and the rotational torque can be detected with higher accuracy.

In the drive shaft monitoring device, in the detected portion, the first and second magnetoresistance change members are arranged so as to sandwich the compression load applying member in the circumferential direction of the drive shaft,
The detection unit includes the excitation unit and the first magnetoresistive member to form a first magnetic circuit on a part of the outer peripheral surface of the drive shaft, and detects a magnetic flux flowing through the first magnetic circuit. A magnetic flux that flows through the second magnetic circuit by forming a second magnetic circuit on a part of the outer peripheral surface of the drive shaft together with the first detecting unit, the exciting unit, and the second magnetoresistance change member It is preferable that a second detection unit for detecting the above is provided.
In this case, the compressive load applying member applies a compressive load corresponding to the rotational torque only to one of the magnetoresistance change members when the drive shaft rotates, and the magnetic flux flowing through the first and second magnetic circuits. Difference can be maximized, and rotational torque can be detected with high accuracy. Also, by performing differential processing of the detection results in the first and second detection units, the influence of the ambient temperature can be offset, and a decrease in rotational torque detection accuracy due to the influence of the ambient temperature can be prevented. . Furthermore, since one detection result is necessarily larger than the other detection result, the rotational direction of the drive shaft can also be detected based on the magnitude result.

In the drive shaft monitoring apparatus, it is preferable that a magnetic member that magnetically couples the excitation unit and the detection unit is used for the excitation unit and the detection unit.
In this case, a magnetic circuit in each part of the excitation part and the detection part is formed inside the magnetic member, and the members for configuring the magnetic circuit in each part are shared by the magnetic member. The number of parts of the device can be reduced, and the configuration of the excitation unit and the detection unit, and thus the monitoring device can be simplified.

  According to the present invention, an excitation coil and a detection coil are not disposed so as to surround the entire outer peripheral surface of the drive shaft, and the sensor device including the detection unit is separated from the drive shaft and the detected portion provided on the drive shaft. Since the rotational torque of the drive shaft is detected by detecting the magnetic flux flowing through the magnetic circuit formed on a part of the outer peripheral surface of the drive shaft, it is difficult to permanently install a torque sensor such as a rolling facility. Thus, even with a very high torque drive shaft, the rotational torque during the operation can be detected accurately and constantly, and the drive shaft can always be monitored.

  Hereinafter, a preferred embodiment of a drive shaft monitoring device of the present invention will be described with reference to the drawings. In addition, in the following description, the case where it applies to the drive shaft of rolling equipment is illustrated and demonstrated.

Embodiment 1

  1 and 2 are a plan view and a side view, respectively, showing a main part of a drive shaft monitoring apparatus according to an embodiment of the present invention. In the drawing, the drive shaft 50 of the rolling equipment has a plurality of shaft portions connected via a cross joint 53 in order to allow an impact in the rolling process. That is, the drive shaft 50 includes a drive shaft portion 51 connected to the drive motor side, a driven shaft portion 52 connected to the rolling roller side, and the cross that connects the drive shaft portion 51 and the driven shaft portion 52. The cross shaft joint 53 allows the driven shaft portion 52 to move up and down with respect to the drive shaft portion 51. The cross shaft joint 53 is provided with bearing cups 53a mounted on the four shafts of the cross shaft, and the shaft portions corresponding to the two bearing cups 53a on different straight lines are bolts. By being fixed, the drive shaft 50 transmits the rotational force of the drive motor to the rolling roller side by rotating in the R direction (FIG. 1) with the cross joint 53 incorporated therein. In the rolling equipment, the two drive shafts 50 are arranged in parallel with each other in the vertical direction, and the steel material is subjected to a rolling process by passing a slab or the like between the two rollers connected to the drive shafts 50. It is configured as follows. In the drive shaft 50, for example, the operation state of the drive shaft 50 is monitored by the drive shaft monitoring device of the present invention provided in the drive shaft portion 51, for example.

The drive shaft monitoring device includes an intermediate flange 1 as a detected portion installed in the drive shaft portion 51, a sensor portion 2 as a sensor device arranged to face the intermediate flange 1, and a cable 4. And a data processing device 3 connected to the sensor unit 2 and disposed on the installation surface.
The intermediate flange 1 is provided with first and second flange members 11 and 12 that are separable in the axial direction of the drive shaft 50, and is divided into a drive motor side and a cross shaft joint 53 side. It is connected between the first and second shaft end portions 51a and 51b of the shaft portion 51, and is configured to transmit the motor rotational force from the shaft end portion 51a to the shaft end portion 51b. That is, in the intermediate flange 1, one end side thereof is connected to a flange portion 51 a 1 formed at the tip end portion of the shaft end portion 51 a by, for example, two connecting keys 54 a that are equally arranged in the circumferential direction of the drive shaft 50. Yes. Similarly, the other end portion side of the intermediate flange 1 is connected to a flange portion 51b1 formed at the tip end portion of the shaft end portion 51b by, for example, two connecting keys 54b equally arranged in the circumferential direction. The flange 1 is incorporated in the drive shaft portion 51 so as to transmit the rotational force to the driven shaft portion 52.

In the intermediate flange 1, the first and second flange members 11 and 12 are connected to each other by, for example, eight key members 13 provided at equal intervals in the circumferential direction of the drive shaft 50. Is transmitted from the flange member 11 to the flange member 12 via the key member 13.
Each key member 13 is also configured to function as a compressive load applying member that applies a compressive load that changes in synchronism with the rotational torque when the drive shaft 50 rotates to a magnetoresistive change member described later. .

  Referring to FIG. 3, the first and second flange members 11 and 12 have columnar base portions 11a and 12a, respectively, and the attachment for the key member 13 is abutted with the base portions 11a and 12a. The bases 11a and 12a are configured so that holes are formed. That is, the right end surface of the base portion 11a in FIG. 3A and the left end surface of the base portion 12a in FIG. 3A are formed in an uneven shape, and the drive shaft 50 is brought into contact with the base portions 11a and 12a. The mounting holes opened on the outer peripheral surface side of the base plate 11a are formed so as to straddle the base portions 11a and 12a at 45 degree intervals in the coaxial circumferential direction. The block-like key members 13 are arranged in the mounting holes, and the key members 13 are fixed to at least one side of the base portions 11a and 12a by bolts (not shown) provided in the axial direction of the drive shaft 50. ing.

Specifically, in the first flange member 11, eight fan-shaped magnetic plates 11 b indicated by hatched portions in the drawing on the right end surface of the base portion 11 a are equally distributed in the circumferential direction of the drive shaft 50. is set up. Further, a concave portion 11c into which the left end portion of the key member 13 is fitted and a rectangular flat surface 11d provided so as to sandwich each concave portion 11c are formed on the right end surface side of the base portion 11a.
Further, in the second flange member 12, eight rectangular magnetic plates 12 b indicated by straight portions in the figure installed on the left end surface of the base portion 12 a are installed equally in the circumferential direction of the drive shaft 50. Has been. Further, the flange member 12 has sixteen magnetoresistance change members 12c (shown by a hatched portion rising to the right in the drawing) attached on the left end surface of the base so as to sandwich the magnetic plates 12b. In the flange member 12, the magnetic plate 12 b and the two magnetoresistance change members 12 c sandwiching the magnetic plate 12 form a recess into which the right side portion of the key member 13 is fitted. Further, the recess is a recess in the flange member 11. 11c and the said attachment hole are formed.

  The second flange member 12 is formed with a fan-shaped recess 12d that engages with the magnetic plate 11b between the two magnetoresistance change members 12c. The second flange member 12 is a key member 13. When connected to the first flange member 11, the magnetic plate 11b is disposed in the recess 12d. Furthermore, when these flange members 11 and 12 are connected, the magnetoresistive change member 12c abuts the end face of the rectangular flat surface 11d, and one side and the other side of the change member 12c in the circumferential direction are magnetic. The plate 11b and the key member 13 are in contact with each other. That is, in the intermediate flange 1, as shown in FIG. 3A, the two magnetoresistance change members 12c sandwich the key member 13 and the magnetic plate 12b in the circumferential direction, and also the magnetic plate 11b in the same circumferential direction. It is comprised so that it may pinch | interpose.

In the intermediate flange 1, the magnetoresistance change member 12c is made of, for example, a steel material (for example, SNCM) having a positive magnetostriction constant. In the magnetic domain of the change member 12c, the easy magnetization direction of the easy magnetization axis is, for example, They are aligned in the circumferential direction. In the magnetoresistive change member 12c, a compressive load synchronized with the rotational torque is applied from the key member 13, whereby the direction of easy magnetization is synchronized with the rotational torque and the direction changes. Thereby, in the magnetoresistive change member 12, the magnetic resistance is changed, and the data processing device 3 detects the rotational torque when the sensor unit 2 detects the magnetoresistive change (details will be described later).
The magnetic plates 11b and 12b are made of a soft magnetic material such as a general structural rolled steel (SS material), and are configured to be magnetically coupled to the magnetoresistance change member 12c. And these magnetic plates 11b and 12b comprise the magnetic circuit suitably formed in the said to-be-detected part side with the magnetoresistive change member 12c. However, these magnetic plates 11b and 12b do not receive a compressive load from the key member 13 even if rotational torque is generated on the drive shaft 50, unlike the magnetic resistance change member 12c.
The base portions 11a and 12a and the key member 13 are made of a nonmagnetic structural material such as SUS304, and are configured not to affect the magnetic flux flowing through the magnetic circuit.

The sensor unit 2 is erected on the outer periphery of the drive shaft 50 by a support member 5 (FIG. 2) whose lower end is placed on the installation surface. Further, as shown in FIG. 4, the sensor unit 2 is provided on the bottomed housing 2a having one end opened and on the one end opening side of the housing 2a, and rolls on the outer peripheral surface of the intermediate flange 1. And a moving wheel 2b.
Inside the casing 2a, the cable 4 is connected, and two power supply units 6 that house a power supply circuit and the like, and an excitation coil 21 connected to one unit 6 by wiring not shown in the figure, The magnetic member 7 around which the detection coils 31 and 32 are wound, the exciting coil 22 connected to the other unit 6 by a wiring not shown, and the magnetic member 8 around which the detection coils 33 and 34 are wound are housed. Yes.

Further, in the housing 2a, the first and second magnetic circuits M1 and M2 indicated by a two-dot chain line in FIG. 5 are driven using the intermediate flange (detected portion) 1 and the magnetic member 7. It is formed in a part on the outer peripheral surface of the shaft 50. That is, in the housing 2a, the magnetic circuit M1 is configured together with the first exciting part for exciting the detected part and the detected part and the first exciting part. The first detection unit for detecting the magnetic flux flowing and the magnetic circuit M2 together with the detected portion and the first excitation unit constitute the second detection unit for detecting the magnetic flux flowing in the magnetic circuit M2. Has been.
In addition, in the housing 2a, the third and fourth magnetic circuits M3 and M4 indicated by a two-dot chain line in the same figure use the intermediate flange 1 and the magnetic member 8, and the outer peripheral surface of the drive shaft 50. It is formed in the upper part. That is, in the housing 2a, the magnetic circuit M3 is configured together with the second exciting part for exciting the detected part and the detected part and the second exciting part, and flows in the magnetic circuit M3. A third detection unit for detecting magnetic flux and a fourth detection unit for detecting the magnetic flux flowing in the magnetic circuit M4 are housed together with the magnetic circuit M4 together with the detected portion and the second excitation unit. ing.
The casing 2a is made of a magnetic material such as an SS material, and each of the above-mentioned magnets whose position on the outer peripheral surface of the intermediate flange 1 moves in accordance with the rotation operation of the drive shaft 50 in the R direction. The circuits M1 to M4 are prevented from being influenced by an external magnetic field such as geomagnetism as much as possible.

Specifically, the magnetic member 7 is made of, for example, a soft magnetic material, and has a base portion 7a disposed in the vertical direction inside the housing 2a. The base portion 7a is a nonmagnetic material whose illustration is omitted. The whole magnetic member 7 is attached in the said housing | casing 2a by being fixed to the housing | casing 2a by the fixing member made from a product.
In addition, referring to FIG. 6 as well, the magnetic member 7 is horizontally branched from the central portion, the upper end portion, and the lower end portion of the base portion 7a so as to be parallel to the axial direction A of the drive shaft 50. There are provided portions 7b, 7c, 7d and extending portions 7e, 7f that are obliquely extended from the horizontal portions 7c, 7d at a predetermined angle with respect to the axial direction A and away from each other. In addition, projecting portions 7g, 7h, and 7i that project toward the intermediate flange 1 are provided at the ends of the horizontal portion 7b and the extending portions 7e and 7f, respectively. Further, the surface of the protruding portion 7g facing the outer peripheral surface of the intermediate flange 1 is configured to function as the first excitation surface 7p included in the first excitation portion. Further, the surfaces of the protrusions 7h and 7i facing the outer peripheral surface of the intermediate flange 1 function as first and second detection surfaces 7q and 7r included in the first and second detection units, respectively. It is configured as follows. And in the magnetic member 7, the said magnetic circuit M1 in each part of a 1st excitation part and a 1st detection part comprises a base part 7a, horizontal part 7b, 7c, the extension part 7e, and the protrusion parts 7g, 7h. The magnetic circuit M2 in each part of the first excitation part and the second detection part is configured inside the base part 7a, the horizontal parts 7b and 7d, the extending part 7f, and the protruding parts 7g and 7i. That is, the magnetic member 7 magnetically couples the first excitation unit and the first detection unit, and magnetically couples the first excitation unit and the second detection unit, so It works as a yoke member through which the magnetic fluxes of the circuits M1 and M2 flow.

Specifically, as shown in FIG. 5, the exciting coil 21 connected to the AC power supply 23 is wound around the horizontal portion 7b. The first excitation surface 7p is arranged to face the magnetic plate 12b or the magnetoresistance change member 12c of the intermediate flange 1. When an alternating current is passed from the alternating current power source 23 to the exciting coil 21, a magnetic flux corresponding to the current is generated in the horizontal portion 7b, and the magnetic flux flows in the first and second magnetic circuits M1 and M2. In this way, the first excitation surface 7p excites the intermediate flange (detected portion) 1 by applying an alternating magnetic field to the opposing magnetic plate 12b or magnetoresistive change member 12c.
As described above, the horizontal portion 7b and the protruding portion 7g of the magnetic member 7, the exciting coil 21, and the AC power source 23 constitute the first exciting portion.

Further, the detection coil 31 connected to the voltmeter 35 is wound around the horizontal portion 7c, and the detection coil 32 connected to the voltmeter 36 is wound around the horizontal portion 7d. The first and second detection surfaces 7q and 7r are arranged to face the magnetic plate 11b or the magnetoresistance change member 12c of the intermediate flange 1.
Each voltmeter 35, 36 detects the induced voltage induced by the change of the magnetic flux flowing through the corresponding horizontal portion 7c, 7d, that is, the magnetic flux (flux density) flowing through the first and second magnetic circuits M1, M2. It is supposed to be.

Specifically, when the first exciting part excites the magnetic plate 12b or the magnetoresistive change member 12c and the magnetic flux flows through the first magnetic circuit M1, the magnetic flux passing through the detected part is changed to the first detection surface. It flows into the horizontal part 7c through 7q and the extending part 7e. In the detection coil 31, a voltage corresponding to a change in magnetic flux flowing in the horizontal portion 7 c is induced, and the induced voltage is detected by the voltmeter 35.
Similarly, when the first exciting part excites the magnetic plate 12b or the magnetoresistive change member 12c and the magnetic flux flows through the second magnetic circuit M2, the magnetic flux passing through the detected part becomes the second detection surface 7r. And it flows into the horizontal part 7d through the extending part 7f. In the detection coil 32, a voltage corresponding to a change in magnetic flux flowing through the horizontal portion 7 d is induced, and the induced voltage is detected by the voltmeter 36.
As described above, the horizontal portion 7c, the extending portion 7e, the protruding portion 7h, the detection coil 31, and the voltmeter 35 of the magnetic member 7 constitute the first detection portion, and the horizontal portion of the magnetic member 7 is provided. 7c, the extending portion 7f, the protruding portion 7i, the detection coil 32, and the voltmeter 36 constitute the second detection portion.

Further, in the magnetic member 7, when the magnetic member 7 is disposed opposite to the outer peripheral surface of the intermediate flange 1, the first excitation surface 7 p and the first and second detection surfaces 7 q and 7 r configured to be flat are provided. It is configured to be arranged in parallel to the vertical direction and with the same separation dimension (gap) with respect to the outer peripheral surface. In the magnetic member 7 and the intermediate flange 1, the magnetic circuits M1 and M2 having the same magnetic path length are formed.
In the magnetic member 7, the first detection surface 7 q is configured so as to face the magnetic plate 12 b or the magnetoresistance change member 12 c provided on the rotation direction R side of the drive shaft 50 with respect to the key member 13, and the second The detection surface 7r is configured to be opposed to the magnetic plate 12b or the magnetoresistive change member 12c provided on the side opposite to the rotation direction R of the drive shaft 50 with respect to the key member 13. As a result, when a compressive load corresponding to the rotational torque is applied to the magnetic resistance change member 12c, the magnetic resistance of only the magnetic circuit M1 decreases (details will be described later).

Similarly to the magnetic member 7, the magnetic member 8 is made of, for example, a soft magnetic material, and has a base portion 8a arranged in the vertical direction inside the casing 2a. The base portion 8a is not shown in the figure. The entire magnetic member 8 is attached to the housing 2a by being fixed to the housing 2a by the fixed member made of non-magnetic material.
Further, as shown in FIG. 5, the magnetic member 8 is horizontally branched from the central portion, the upper end portion, and the lower end portion of the base portion 8 a so as to be parallel to the axial direction A of the drive shaft 50. There are provided portions 8b, 8c, 8d and extending portions 8e, 8f that are obliquely extended from the horizontal portions 8c, 8d at a predetermined angle with respect to the axial direction A so as to be separated from each other. Further, projecting portions 8g, 8h, and 8i that project toward the intermediate flange 1 are provided at the ends of the horizontal portion 8b and the extending portions 8e and 8f, respectively. Further, the surface of the protruding portion 8g facing the outer peripheral surface of the intermediate flange 1 is configured to function as the second excitation surface 8p included in the second excitation portion. Further, the surfaces of the protrusions 8h and 8i facing the outer peripheral surface of the intermediate flange 1 function as third and fourth detection surfaces 8q and 8r included in the third and fourth detection units, respectively. It is configured as follows. In the magnetic member 8, the magnetic circuit M3 in each part of the second excitation part and the third detection part is configured inside the base part 8a, the horizontal parts 8b and 8c, the extending part 8e, and the protruding parts 8g and 8h. The magnetic circuit M4 in each part of the second excitation part and the fourth detection part is configured inside the base part 8a, the horizontal parts 8b and 8d, the extending part 8f, and the protruding parts 8g and 8i. That is, the magnetic member 8 magnetically couples the second excitation unit and the third detection unit, and magnetically couples the second excitation unit and the fourth detection unit, so It works as a yoke member through which the magnetic fluxes of the circuits M3 and M4 flow.

Specifically, as shown in FIG. 5, an exciting coil 22 connected to an AC power source 24 is wound around the horizontal portion 8b. The second excitation surface 8p is arranged to face the magnetic plate 11b or the magnetoresistance change member 12c of the intermediate flange 1. When an alternating current flows from the alternating current power supply 24 to the exciting coil 22, a magnetic flux corresponding to the current is generated in the horizontal portion 8b, and the magnetic flux flows in the third and fourth magnetic circuits M3 and M4. In this way, the second excitation surface 8p excites the intermediate flange (detected portion) 1 by applying an AC magnetic field to the opposing magnetic plate 11b or magnetoresistive change member 12c.
As described above, the horizontal portion 8b and the protruding portion 8g of the magnetic member 8, the exciting coil 22, and the AC power supply 24 constitute the second exciting portion.

A detection coil 33 connected to a voltmeter 37 is wound around the horizontal portion 8c, and a detection coil 34 connected to a voltmeter 38 is wound around the horizontal portion 8d. The third and fourth detection surfaces 8q and 8r are arranged to face the magnetic plate 12b or the magnetoresistance change member 12c of the intermediate flange 1.
Each voltmeter 37, 38 detects an induced voltage induced by a change in magnetic flux flowing through the corresponding horizontal portion 8c, 8d, that is, magnetic flux (flux density) flowing through the third and fourth magnetic circuits M3, M4. It is supposed to be.

Specifically, when the second excitation unit excites the magnetic plate 11b or the magnetoresistive change member 12c and the magnetic flux flows through the third magnetic circuit M3, the magnetic flux that has passed through the detected portion becomes the third detection surface. It flows into the horizontal part 8c through 8q and the extending part 8e. In the detection coil 33, a voltage corresponding to a change in magnetic flux flowing in the horizontal portion 8 c is induced, and the induced voltage is detected by the voltmeter 37.
Similarly, when the second exciting part excites the magnetic plate 11b or the magnetoresistive change member 12c and the magnetic flux flows through the fourth magnetic circuit M4, the magnetic flux passing through the detected part becomes the fourth detection surface 8r. And it flows into the horizontal part 8d via the extension part 8f. In the detection coil 34, a voltage corresponding to a change in magnetic flux flowing through the horizontal portion 8 d is induced, and the induced voltage is detected by a voltmeter 38.
As described above, the horizontal portion 8c, the extending portion 8e, the protruding portion 8h, the detection coil 33, and the voltmeter 37 of the magnetic member 8 constitute the third detection portion, and the horizontal portion of the magnetic member 7 is provided. 8c, the extended portion 8f, the protruding portion 8i, the detection coil 34, and the voltmeter 38 constitute the fourth detection portion.

Further, in the magnetic member 8, when the magnetic member 8 is disposed opposite to the outer peripheral surface of the intermediate flange 1, the second excitation surface 8p and the third and fourth detection surfaces 8q, 8r configured to be flat are provided. It is configured to be arranged in parallel to the vertical direction and with the same separation dimension (gap) with respect to the outer peripheral surface. In the magnetic member 8 and the intermediate flange 1, the magnetic circuits M3 and M4 having the same magnetic path length are formed. Further, the magnetic path lengths in the magnetic circuits M3 and M4 are configured to be the same as those in the magnetic circuits M1 and M2.
Further, in the magnetic member 8, the third detection surface 8 q is configured so as to be opposed to the magnetic plate 11 b or the magnetoresistance change member 12 c provided on the rotation direction R side of the drive shaft 50 with respect to the key member 13. The detection surface 8r is configured to be opposed to the magnetic plate 11b or the magnetoresistive change member 12c provided on the opposite side to the rotation direction R of the drive shaft 50 with respect to the key member 13. As a result, when a compressive load corresponding to the rotational torque is applied to the magnetic resistance change member 12c, only the magnetic circuit M3 has its magnetic resistance reduced (details will be described later).

  Further, as shown in FIG. 5, the magnetic member 8 is mounted in the housing 2a while being rotated by 180 degrees with respect to the magnetic member 7, and the first excitation surface 7p is provided on the magnetic plate 12b. When the flange member 12 is opposed to the portion between the two magnetoresistance change members 12c without facing the magnetoresistance change member 12c, the second excitation surface 8p has the magnetic plate 11b or the magnetoresistance change member. It always faces 12c. Thereby, in the sensor part 2, when one detection part of the said 1st and 2nd detection part and the 3rd and 4th detection part cannot detect magnetic flux, the other detection part detects magnetic flux. It is comprised so that rotation torque can always be detected.

Returning to FIG. 2, the data processing device 3 is configured by, for example, a panel computer, and is configured using a detection unit 3 a and a control unit 3 b configured by a CPU and the like, and a nonvolatile memory. And a storage unit 3c for storing data such as programs used in the detection unit 3a and the control unit 3b and information such as detection results of the detection unit 3a.
Each voltage signal from the detection coils 31 to 34 (FIG. 5) is input to the detection unit 3a, and the corresponding voltmeters 35 to 38 (FIG. 5) for obtaining the respective voltage values (induced voltage values). Is functionally provided by software, for example. And the detection part 3a detects the rotational torque of the drive shaft 50 based on the detected induced voltage value. Specifically, the detection unit 3a detects the rotational torque of the drive shaft 50 by performing differential processing of the detected voltage values of the voltmeters 35 and 36 or differential processing of the detected voltage values of the voltmeters 37 and 38. It is configured.

Specifically, the detection unit 3 a flows through the induced voltage value generated by the magnetic flux flowing through the first magnetic circuit M <b> 1 that is the detection result of the voltmeter 35 and the second magnetic circuit M <b> 2 that is the detection result of the voltmeter 36. The difference from the induced voltage value generated by the magnetic flux is obtained. Then, the detection unit 3a has a correlation with the data value after the differential processing by referring to a table or the like stored in advance in the storage unit 3c based on the data value after the differential processing. The rotational torque value of the drive shaft 50 during the rolling process is acquired.
Similarly, the detection unit 3a detects the induced voltage value generated by the magnetic flux flowing through the third magnetic circuit M3, which is the detection result of the voltmeter 37, and the magnetic flux flowing through the fourth magnetic circuit M4, which is the detection result of the voltmeter 38. The difference from the induced voltage value generated by the above is obtained. Then, the detection unit 3a has a correlation with the data value after the differential processing by referring to a table or the like stored in advance in the storage unit 3c based on the data value after the differential processing. The rotational torque value of the drive shaft 50 during the rolling process is acquired.

The control unit 3b is provided with a function for determining whether or not an abnormality has occurred in the rotational operation of the drive shaft 50 based on the rotational torque value detected by the detection unit 3a. That is, when the rotational torque value exceeds a preset allowable upper limit value, the controller 3b causes the drive shaft 50 to flow a steel material having a size larger than the set size between the rolling rollers between the rollers. It is determined that an overload operation such as mis-rolling is being performed, and an instruction signal is output to a protective device such as a torque limiter to urgently stop the drive motor. In addition, when the rotational torque value is smaller than the preset allowable lower limit value, the control unit 3b causes a crack or the like to occur in the portion of the constituent member on the transmission path of the motor rotational force in the drive shaft 50. It is determined that the motor rotational force is not normally transmitted (that is, torque loss has occurred in the drive shaft 50), and the drive motor is urgently stopped.
As described above, the data processing device 3 detects an abnormality in the rotational operation based on the rotational torque of the drive shaft 50 during the rolling process and stops the motor, thereby preventing early deterioration of the quality of the rolled steel product. Can do.

Further, in the data processing device 3, the storage unit 3c accumulates the rotational torque value, and the control unit 3b determines the degree of fatigue (aging over time) of the drive shaft 50 based on this accumulated data, It is designed to judge signs of damage.
Further, in this processing device 3, the control unit 3b includes history information including the induced voltage value and the rotational torque value detected by the detection unit 3a, their waveforms, and the date and time of abnormality detection stored in the storage unit 3c. Etc. are configured to be displayed on a display unit (not shown).
Further, the processing device 3 is configured to be connectable to an information processing terminal such as a PC installed in a monitoring room or the like separated from the rolling facility by a communication line capable of bidirectional communication. Data such as the rotational torque value can be transferred.

Hereinafter, the operation of the drive shaft monitoring apparatus of the present embodiment configured as described above will be described with reference to FIGS.
When the drive shaft 50 is rotationally driven in the R direction with no load, that is, when the steel material to be processed is not flowing between the rolling rollers and the rolling process is not performed, each key member 13 (detected) Part), almost no distortion in synchronism with the rotational torque of the drive shaft 50 occurs. Therefore, a compressive load is hardly applied from the key member 13 to the magnetic resistance change member 12c (detected portion) in contact with each key member 13 in the R direction (the rotation direction of the drive shaft 50). For this reason, in the magnetoresistance change member 12c, distortion (elastic deformation) due to the compression load hardly occurs, and the easy magnetization direction Me of the easy magnetization axis is aligned in advance as shown in FIG. In other words, the direction of the easy axis of magnetization is not changed while maintaining the direction parallel to the circumferential direction C of the drive shaft. Therefore, in the magnetoresistance change member 12c, the magnetoresistance does not change, and the magnetoresistances have the same value in the magnetic circuits M1 and M2, and M3 and M4. As a result, on the magnetic member 7 side, the magnetic flux generated by the alternating magnetic field from the exciting coil 21 is equally divided into the magnetic circuits M1 and M2, and the induced voltage values detected by the voltmeters 35 and 36 also show the same value. . The waveforms of these induced voltage values are also the same waveform that changes sinusoidally according to the frequency of the AC power supply 23. Similarly, on the magnetic member 8 side, the magnetic flux generated by the alternating magnetic field from the exciting coil 22 is equally divided into the magnetic circuits M3 and M4, and the induced voltage values detected by the voltmeters 37 and 38 also show the same value. . The waveforms of these induced voltage values are also the same waveform that changes sinusoidally according to the frequency of the AC power supply 24. As a result, the detection unit 3a reads a predetermined rotational torque value when the rolling process is not performed from the storage unit 3c and notifies the operator.

  Subsequently, when a steel material is supplied between the rolling rollers and the rolling process is started, a compression stress acts on each key member 13 due to the rotation (torsion) torque of the drive shaft 50 that greatly increases with the rolling process. Thus, distortion (elastic deformation) corresponding to this compressive stress occurs. Then, the elastic deformation at each key member 13 acts as a compressive load on the magnetoresistance change member 12c adjacent in the R direction. Thereby, in the magnetoresistive change member 12c, distortion generate | occur | produces according to the applied compressive load, and a direction changes according to the distortion in the magnetization easy axis | shaft of the said magnetoresistive change member 12c. That is, the easy magnetization direction Me is inclined with respect to the circumferential direction C, and as illustrated in FIG. 7B, the direction of the magnetic flux flowing through the corresponding magnetic circuit is inclined at a maximum of 90 degrees (a dotted line in FIG. 7). It changes so as to be parallel to the arrow). Thus, when the easy magnetization direction Me is inclined, in the magnetoresistance change member 12c, the magnetic permeability increases in proportion to the direction change, and the magnetoresistance decreases.

Further, since the compressive load from each key member 13 is applied only to the magnetoresistive change member 12c adjacent in the R direction, it is included in the magnetic circuit M1 among the magnetic circuits M1 and M2 on the magnetic member 7 side. Further, the magnetic resistance of the magnetoresistance change member 12c decreases, and the magnetoresistance of the magnetoresistance change member 12c included in the magnetic circuit M2 does not change. For this reason, the magnetic resistance in the magnetic circuit M2 does not change, only the magnetic resistance in the magnetic circuit M1 is reduced, and the magnetic flux flowing through the magnetic circuit M1 is larger than the magnetic flux flowing through the magnetic circuit M2. As a result, the waveform of the induced voltage value detected by the voltmeter 35 is the waveform of the voltmeter 36 indicated by the dotted line in FIG. 8A, as indicated by the solid waveform 61 in FIG. It is larger than 62.
Similarly, among the magnetic circuits M3 and M4 on the magnetic member 8 side, the magnetic resistance of the magnetoresistance change member 12c included in the magnetic circuit M3 decreases, and the magnetoresistance of the magnetoresistance change member 12c included in the magnetic circuit M4. Does not change. For this reason, the magnetic resistance in the magnetic circuit M4 does not change, only the magnetic resistance in the magnetic circuit M3 becomes small, and the magnetic flux flowing through the magnetic circuit M3 becomes larger than the magnetic flux flowing through the magnetic circuit M4. As a result, the waveform of the induced voltage value detected by the voltmeter 37 is the waveform of the voltmeter 38 indicated by the dotted line in FIG. 8B, as indicated by the solid waveform 63 in FIG. Larger than 64.

Then, the detection unit 3a performs a differential process of subtracting the detection voltage value of the voltmeter 36 from the detection voltage value of the voltmeter 35 to obtain a difference value indicated by “Ta” in FIG. And the detection part 3a acquires a rotational torque value with reference to the memory | storage part 3c based on this calculated | required value, and notifies an operator.
When the first excitation surface 7p of the magnetic member 7 does not face the magnetic plate 12b and the magnetoresistance change member 12c according to the rotation operation of the drive shaft 50, the magnetic circuits M1 and M2 on the magnetic member 7 side It is not formed on the intermediate flange 1, and the detected voltage values of the voltmeters 35 and 36 are almost zero. On the other hand, on the magnetic member 8 side, when the excitation surface 7p does not face the magnetic plate 12b and the magnetoresistance change member 12c, the second excitation surface 8p faces the magnetic plate 11b and the magnetoresistance change member 12c. Magnetic circuits M3 and M4 are formed on the intermediate flange 1. Then, the detection unit 3a performs a differential process for subtracting the detection voltage value of the voltmeter 38 from the detection voltage value of the voltmeter 37, detects the rotational torque value based on the difference value “Tb”, Notify

As described above, the detection unit 3a acquires the rotational torque value by using the differential processing results of the first and second detection units and the differential processing results of the third and fourth detection units in a complementary manner. Therefore, it is possible to prevent a short time period during which the rotational torque value cannot be obtained during monitoring of the drive shaft 50, and it is possible to more reliably perform real-time monitoring of the drive shaft 50.
Further, as described above, as the rotational torque of the drive shaft 50 increases, only the detection results of the first and third detection units on the rotational direction side increase, so that the detection unit 3a is, for example, the first and second detection units. The rotation direction of the drive shaft can also be detected by comparing the detection results of the detectors.

  In the present embodiment configured as described above, the magnetic resistance change member 12c and a key member (compression load application) that applies a compressive load that changes in synchronization with the rotational torque of the drive shaft 50 to the magnetoresistance change member 12c. Member) 13 is provided on the intermediate flange (detected portion) 1 installed on the drive shaft portion 51. And in this to-be-detected part, it is comprised so that the magnetic resistance of the magnetoresistive change member 12c may change according to the said rotational torque. Further, the above-mentioned detected part is excited by excitation coils (excitation parts) 21 and 22 wound around the magnetic members 7 and 8, and the detection coils (detection parts) 31, 32, 33 and 34 are respectively applied to the magnetic members 7 and 8. The magnetic circuits M1 to M4 constituted by the detected part, the excitation part, and the detection part are formed on a part of the outer peripheral surface of the drive shaft 50. And the said detection part detects the induced voltage produced according to the magnetic flux which flows through each magnetic circuit M1-M4, and the detection part 3a calculates the said rotational torque based on the said induced voltage which changes in synchronization with the said rotational torque. Detected. In this way, the rotational torque of the drive shaft 50 can be detected without arranging the excitation coils 21 and 22 and the detection coils 31 to 34 so as to surround the entire outer peripheral surface of the drive shaft 50. Therefore, the magnetostrictive sensor is used. Unlike conventional examples, even a large drive shaft used in rolling equipment or the like can monitor the drive shaft by accurately and constantly detecting rotational torque during operation. Further, since the detection unit and the sensor unit (sensor device) 2 including the detection unit are provided independently of the intermediate flange 1, the sensor unit including the detection unit can be used regardless of the magnitude of the rotational torque of the drive shaft 50. There is no need to increase the structural strength of the detection unit or the like according to this torque. As a result, unlike the conventional example using the strain gauge, even when the rotational torque is very high, the detection unit can detect the magnetic flux fluctuation and perform torque detection. Moreover, since the detected portion is provided in the intermediate flange 1, the detected portion can be easily attached to the existing drive shaft, and even when the monitored drive shaft is changed, it is easy to cope with it. Is possible.

Embodiment 2

FIG. 9 is an enlarged plan view showing a main part of a drive shaft monitoring apparatus according to another embodiment. In the figure, the main difference between this embodiment and the above embodiment is that a DC power source is used instead of the AC power source, and a magnetic sensor is provided instead of the detection coil.
As shown in FIG. 9, in this embodiment, a DC power supply 25 is connected to an excitation coil 21 provided on the magnetic member 7 side, and the excitation unit applies a predetermined DC magnetic field to the intermediate flange (detected portion) 1. Is configured to give to. Magnetic sensors 41 and 42 are provided above the horizontal portions 7c and 7d of the magnetic member 7, respectively. These magnetic sensors 41 and 42 are composed of, for example, MI (Magnet Impedance) sensors, detect the magnetic fluxes flowing through the first and second magnetic circuits M1 and M2 with high sensitivity, and detect the detection signals. Are output to detectors 45 and 46, respectively. The detectors (ammeters) 45 and 46 are functionally provided in the detection unit 3a by, for example, software, and the detection unit 3a detects the detected magnetic flux value output from the magnetic sensors 41 and 42 ( A differential process is performed on the detected Gaussian value, and the rotational torque value of the drive shaft 50 is detected based on the value after the differential process.

  Similarly, a DC power supply 25 is connected to the excitation coil 22 on the magnetic member 8 side, and the excitation unit is configured to apply a predetermined DC magnetic field to the intermediate flange (detected unit) 1. Also, above the horizontal portions 8c and 8d of the magnetic member 8, magnetic sensors 43 and 44 configured by, for example, MI sensors are provided, and flow through the third and fourth magnetic circuits M3 and M4. Magnetic flux is detected with high sensitivity, and the detection signal is output to detectors 47 and 48, respectively. The detectors (ammeters) 47 and 48 are functionally provided in the detection unit 3a by software, for example, and the detection unit 3a detects the detected magnetic flux value (detection) from the magnetic sensors 43 and 44. Differential processing is performed on the Gaussian value), and the rotational torque value of the drive shaft 50 is detected based on the value after the differential processing.

  Specifically, when the drive shaft 50 is rotationally driven in the R direction in the no-load state, the magnetic resistance in all the magnetoresistance change members 12c has not changed, and the first and second In the magnetic circuits M1 and M2 and the third and fourth magnetic circuits M3 and M4, the same magnetic flux flows. For this reason, the detected magnetic flux values at the detectors 45 to 48 show predetermined Gaussian values when the corresponding magnetic circuits M1, M2 or M3, M4 on the intermediate flange 1 are formed. That is, only when the first or second excitation surface 7p, 8p is opposed to the magnetic circuit constituent members (that is, the magnetic plates 11b, 12b and the magnetoresistive change member 12c) provided on the intermediate flange 1. Magnetic circuits M1, M2 or third and fourth magnetic circuits M3, M4 are formed on the intermediate flange 1, and the magnetic flux flowing through the circuits is the first and second detectors or the third and fourth magnetic circuits. It is detected by the detection unit and indicated by the same Gaussian value in the detectors 45 and 46 or the detectors 47 and 48. In addition, since the detectors 45 and 46 and the detectors 47 and 48 have the same detection result as described above, when the detection unit 3a performs the differential processing, the value after the processing becomes zero. Therefore, the detection unit 3a reads a predetermined rotational torque value when the rolling process is not performed from the storage unit 3c and notifies the operator.

Subsequently, when the steel material is supplied between the rolling rollers and the rolling process is started, the compression load from the key member 13 applied to the magnetoresistance change member 12c is applied to the drive shaft 50 as in the case of the above embodiment. Therefore, the direction of the easy axis of magnetization in the magnetoresistive change member 12c changes according to the rotational torque. As a result, in the magnetic resistance change member 12c, the magnetic permeability increases in proportion to the change in direction, and the magnetic resistance decreases. Further, this decrease in magnetic resistance occurs only in the magnetoresistance change member 12c included in the magnetic circuits M1 and M3, and does not occur in the magnetoresistance change member 12c included in the magnetic circuits M2 and M4. The waveform of the detected magnetic flux value detected at 45 is larger than the waveform 72 at the voltmeter 46 indicated by the dotted line in FIG. 10A, as indicated by the solid waveform 71 in FIG. It will be a thing. The waveform of the detected magnetic flux value detected by the detector 47 is a waveform 74 at the voltmeter 48 indicated by a dotted line in FIG. 10B, as indicated by a solid waveform 73 in FIG. Bigger than that.
Then, the detection unit 3a sequentially performs the differential processing on the detection results of the detectors 45 and 46 and the differential processing on the detection results of the detectors 47 and 48, so that “ta” in FIG. The difference value indicated by “and the difference value indicated by“ tb ”in FIG. 5B are respectively obtained, and the detection unit 3a refers to the storage unit 3c based on these values to determine the rotational torque value. Acquire and notify the worker.

  As described above, in the present embodiment, a detection unit configured without providing an excitation coil or a detection coil around the entire circumference of the drive shaft 50 and separately from the intermediate flange (detected unit) 1 and a sensor unit including the detection unit Since the rotational torque of the drive shaft 50 can be detected by the (sensor device) 2, the same effects as those of the first embodiment can be obtained. Further, since the magnetic fluxes flowing through the magnetic circuits M1 to M4 corresponding to the magnetic sensors 41 to 44 can be detected with high sensitivity, the change in the magnetic fluxes in the magnetic circuits M1 to M4 can be detected with high accuracy, and the rotational torque can also be highly accurate. Can be detected. In addition to the above description, the magnetic flux flowing through each magnetic circuit may be detected by another magnetic sensor such as a Hall element or an MR sensor.

  In the above description, the case where the present invention is applied to a drive shaft of a rolling facility has been described. However, the present invention drives a detected portion whose magnetic resistance changes by generating distortion in synchronization with the rotational torque of the drive shaft. Provided on a flange installed on the shaft, and having an excitation portion provided opposite to the detected portion and having an excitation surface for exciting the detected portion, and a detection surface arranged opposite to the detected portion, and It is sufficient that the detection unit and the excitation unit have a detection unit that forms a magnetic circuit on a part of the outer peripheral surface of the drive shaft and detects a magnetic flux flowing through the magnetic circuit. For example, a paper winding roller in a papermaking facility The present invention can also be used for monitoring other drive shafts such as a drive shaft for driving the motor.

  In the above description, the shaft end portion of the drive shaft portion is divided into the first and second shaft end portions, and the first and second flange members are disposed between the flange portions installed at the respective shaft end portions. However, the present invention is not limited to this, and for example, the detected portion may be formed on the flange on the motor side of the drive shaft portion. . In addition, it is possible to install a flange including the detected part on the driven shaft part side, but unlike this driven shaft part, the detected part is provided on the drive shaft part side that does not move up and down at the start of the rolling process. It is preferable to provide it.

  In the above description, a magnetic resistance changing member is provided on the second flange member on the rolling roller side, and a key member that is disposed between the first and second flange members and transmits a rotational force is disposed on the magnetic resistance. The configuration used as a compressive load applying member for applying a compressive load to the change member has been described. However, the detected portion of the present invention may be provided with a magnetoresistive change member and a compressive load applying member. Even with a configuration in which a load corresponding to the rotational torque of the drive shaft is applied to the magnetoresistive variable member installed on the first flange member on the drive motor side by a compression load applying member provided separately from the key member that transmits power between the members Good. Moreover, the structure which provides at least one of the said magnetic resistance change member and a compressive load provision member in the part of the drive shaft other than a flange may be sufficient. However, as described above, the case where the key member is also used as the compression load applying member is preferable in that the number of parts of the detected portion can be reduced.

In the above description, the configuration in which the easy magnetization direction in the magnetoresistive change member is aligned in the circumferential direction has been described. However, the present invention is not limited to this, and the easy magnetization direction may be aligned in the axial direction. In addition, the rotational torque can be detected without aligning the easy magnetization direction depending on the magnitude of the magnetic field applied by the excitation unit. However, as described above, it is preferable to align in advance in a predetermined direction because the change in magnetic resistance synchronized with the rotational torque in the detected portion can be increased and torque detection can be performed with higher accuracy.
In the above description, the case where the magnetoresistance change member is made of a steel material having a positive magnetostriction constant has been described. However, the present invention detects that the magnetoresistance has changed due to the compression load from the compression load application member. There is no limitation as long as it can be detected on the surface, and for example, a material having a high magnetostriction constant or a high magnetostrictive film may be coated only on the surface facing the detection surface.

  In the above description, the sensor unit is provided with the magnetic member for forming the first and second magnetic circuits and the magnetic member for forming the third and fourth magnetic circuits. However, the sensor unit of the present invention is not limited to this, and one sensor unit may be used depending on the magnitude of the compressive load generated according to the rotational torque, the magnitude of the change in magnetoresistance due to the load, or the detection accuracy of the detection coil or the like. The sensor unit can be configured so that only the magnetic circuit is formed. However, the case where the detection results of the two detection units are differentially processed is preferable in that the temperature correction in each detection unit can be automatically performed and the detection accuracy of the rotational torque can be easily improved. Furthermore, as described above, the case where four detection units are provided and the detection results after two differential processes are used in a complementary manner is more preferable in terms of preventing a period during which rotational torque cannot be obtained.

  In the above description, the configuration in which the excitation unit and the detection unit are magnetically coupled using the magnetic member has been described. However, the present invention is not limited to this, for example, the excitation unit and the first detection unit. The magnetic member may be configured to be magnetically coupled using three magnetic members for configuring each of the first detection unit and the second detection unit. However, as described above, the sensor unit (excitation unit and detection unit) having a simple configuration with a small number of parts is used when using a magnetic member in which the excitation unit and the detection unit are magnetically coupled. Is preferable in that it can be configured.

It is a top view which shows the principal part of the drive shaft monitoring apparatus which concerns on one Embodiment of this invention. It is a side view which shows the principal part of the drive shaft monitoring apparatus shown in FIG. (A) is a side view which shows the structure of the intermediate | middle flange (detected part) shown in FIG. 1, (b) and (c) are the 1st and 2nd when it sees from the axial direction of a drive shaft, respectively. It is a top view which shows the structure of a flange member. It is the IV-IV sectional view taken on the line of FIG. It is an enlarged plan view which shows the principal part of the drive shaft monitoring apparatus shown in FIG. (A), (b), and (c) are the side view, top view, and top view of the magnetic member shown in FIG. 5, respectively. It is a figure which shows the magnetic domain distribution in the magnetoresistive change member shown in FIG. 5, (a) and (b) are when the torsional stress is acting on the magnetoresistive change member and when the torsional stress is acting respectively. It is a figure which shows the magnetization easy direction of the said magnetic domain distribution. FIG. 6 is a graph showing a detection waveform of each voltmeter shown in FIG. 5, wherein (a) is a specific detection of the first and second voltmeters when a torsional stress is applied to the magnetoresistance change member. It is a graph which shows a waveform, (b) is a graph which shows the specific detection waveform of the 3rd and 4th voltmeter when the torsional stress is acting on the said magnetoresistive change member. It is an enlarged plan view which shows the principal part of the drive shaft monitoring apparatus which concerns on another embodiment. 10 is a graph showing a detection waveform of each detector shown in FIG. 9, wherein (a) is a specific detection of the first and second detectors when a torsional stress is applied to the magnetoresistive change member. It is a graph which shows a waveform, (b) is a graph which shows the specific detection waveform of the 3rd and 4th detector in case the torsional stress is acting on the said magnetoresistive change member.

Explanation of symbols

1 Intermediate flange (Detected part)
2 Sensor unit (sensor device)
7, 8 Magnetic member (excitation part, detection part)
11 First flange member (detected portion)
11b Magnetic plate (detected part)
12 Second flange member (flange)
12b Magnetic plate (magnetic circuit component)
12c Magnetoresistance change member 13 Key member (compression load applying member)
21, 22 Excitation coil (excitation part)
31, 32, 33, 34 Detection coil (detection unit)
23, 24 AC power supply (excitation part)
35, 36, 37, 38 Voltmeter (detection unit)
25, 26 DC power supply (excitation part)
41, 42, 43, 44 Magnetic sensor (detection unit)
45, 46, 47, 48 Detector (detector)
50 Drive shaft M1, M2, M3, M4 Magnetic circuit

Claims (5)

A drive shaft monitoring device for monitoring a drive shaft,
A detected portion in which the magnetic resistance is changed by being distorted in synchronization with the rotational torque of the drive shaft, provided on a flange installed on the drive shaft,
An excitation unit provided with an excitation surface that is arranged opposite to the detection unit and excites the detection unit;
A magnetic circuit is formed on a part of the outer peripheral surface of the drive shaft together with the detected part and the exciting part, and a magnetic flux flowing through the magnetic circuit is detected. A drive shaft monitoring device, comprising: A drive shaft monitoring device for monitoring a drive shaft,
A detected portion in which the magnetic resistance changes by being distorted in synchronization with the rotational torque of the drive shaft while being provided on the drive shaft,
An excitation unit provided with an excitation surface that is arranged opposite to the detection unit and excites the detection unit;
A magnetic circuit is formed on a part of the outer peripheral surface of the drive shaft together with the detected part and the exciting part, and a magnetic flux flowing through the magnetic circuit is detected. And a detecting unit that
The detected portion includes a magnetoresistive change member in which an easy magnetization direction of an easy magnetization axis is aligned in a predetermined direction;
A compression load applying member that changes a direction of easy magnetization of the magnetoresistance change member by applying a compression load that changes in synchronization with the rotational torque of the drive shaft to the magnetoresistance change member; A drive shaft monitoring device characterized by the above. In the detected part, the first and second magnetoresistance change members are arranged so as to sandwich the compression load application member in the circumferential direction of the drive shaft,
The detection unit includes the excitation unit and the first magnetoresistive member to form a first magnetic circuit on a part of the outer peripheral surface of the drive shaft, and detects a magnetic flux flowing through the first magnetic circuit. A first detector that
A second detection unit configured to form a second magnetic circuit on a part of the outer peripheral surface of the drive shaft together with the excitation unit and the second magnetoresistance change member, and detect a magnetic flux flowing through the second magnetic circuit. The drive shaft monitoring device according to claim 2, wherein the drive shaft monitoring device is provided.   The drive shaft monitoring apparatus according to any one of claims 1 to 3, wherein the excitation unit and the detection unit use magnetic members that magnetically couple the excitation unit and the detection unit. A sensor device for a drive shaft monitoring device in which a detected portion whose magnetic resistance changes by distorting in synchronization with the rotational torque of the drive shaft is provided on a flange installed on the drive shaft,
An excitation unit having an excitation surface for exciting the detected portion;
A magnetic circuit is formed on a part of the outer peripheral surface of the drive shaft together with the detected part and the exciting part, and a magnetic flux flowing through the magnetic circuit is detected. A sensor device for a drive shaft monitoring device, comprising:

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