JP6941284B2 - Rotation detector and cable with sensor - Google Patents

Description

The present invention relates to a rotation detection device and a cable with a sensor.

Conventionally, for example, a rotation detection device used for a wheel bearing unit and detecting a rotation speed of a rotating member rotating together with a wheel is known (see, for example, Patent Document 1).

In Patent Document 1, a member to be detected that is attached to a rotating member and has a plurality of magnetic poles along the circumferential direction of the rotating member and a fixing member that rotatably supports the rotating member are attached to generate a magnetic field of the member to be detected. A rotation detection device including a magnetic sensor having a detection element for detection is described.

Japanese Unexamined Patent Publication No. 2013-47636

By the way, as described above, in the rotation detection device that measures the rotation speed of the wheel, the rotation speed of the wheel can be detected even if a failure of the magnetic sensor occurs, or the rotation speed of the wheel can be detected more accurately. There is a demand to use a plurality of magnetic sensors so that it can be used.

When a plurality of magnetic sensors are mounted on the sensor unit, the size of the entire sensor unit becomes large, and there is a possibility that, for example, the sensor unit cannot be inserted into the holding hole for holding the sensor unit. Therefore, there is a demand for keeping the sensor unit small even when a plurality of magnetic sensors are mounted.

Therefore, an object of the present invention is to provide a rotation detection device and a cable with a sensor, which are provided with a plurality of magnetic sensors and whose sensor unit can be miniaturized.

The present invention aims to solve the above problems, and includes a member to be detected, which is attached to a rotating member and has a plurality of magnetic poles provided along a circumferential direction centered on the rotation axis of the rotating member. It is attached to a fixed member that does not rotate with the rotation of the rotating member, and includes a sensor unit that is arranged so as to face the detected member, and the sensor unit detects a magnetic field from the detected member. It has a plate-shaped detector having a magnetic detection element, a signal processing circuit for processing a signal output from the magnetic detection element, and a covering body that collectively covers the magnetic detection element and the signal processing circuit. Each of the detection units is laminated in a direction opposite to the sensor unit and the member to be detected, and the magnetic sensor arranged farthest from the member to be detected is a magnetic sensor. Provided is a rotation detection device having a higher sensitivity than the magnetic sensor arranged closest to the member to be detected.

Further, in the present invention, for the purpose of solving the above-mentioned problems, the detected member is attached to the rotating member and has a plurality of magnetic poles provided along the circumferential direction about the rotation axis of the rotating member. A cable with a sensor used in a rotation detection device, which is attached to a fixing member that does not rotate with the rotation of the rotating member, and has a sensor unit arranged so as to face the detected member. , The sensor unit provided at the end of the cable, and the sensor unit is output from the magnetic detector element and the magnetic detector element that detect a magnetic field from the member to be detected. A signal processing circuit for processing a signal and a plurality of magnetic sensors having a plate-shaped detection unit having a resin mold that collectively covers the magnetic detection element and the signal processing circuit are provided, and each of the detection units includes a signal processing circuit. Provided is a cable with a sensor, which is laminated in a direction opposite to the sensor unit and the member to be detected.

According to the present invention, it is possible to provide a rotation detection device and a cable with a sensor, which are provided with a plurality of magnetic sensors and whose sensor unit can be miniaturized.

It is sectional drawing which shows the structural example of the rotation detection device which concerns on one Embodiment of this invention, and the wheel bearing device for a vehicle which has this rotation detection device. It is a perspective view of a sensor part. (A) is a side view of the sensor unit, and (b) is a fracture surface view showing the housing in cross section. (A) is a top view of the sensor unit, (b) is a fracture surface view showing the housing in cross section, and (c) is a top view of the magnetic sensor and the electric wire. It is a figure which shows the cable with a sensor which concerns on one modification of this invention, (a) is a schematic block diagram, (b) is a sectional view of a cable.

[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Structure of Wheel Bearing Device 10)
FIG. 1 is a cross-sectional view showing a configuration example of a rotation detection device according to the present embodiment and a wheel bearing device for a vehicle having the rotation detection device.

The wheel bearing device 10 includes an inner ring 11 as a rotating member having a cylindrical main body 110 and a flange 111 to which the wheels are attached, an outer ring 12 arranged on the outer peripheral side of the main body 110 of the inner ring 11, and an inner ring 11. It is arranged between a pair of raceway surfaces 11b and 11b formed on the outer peripheral surface 11a and a pair of raceway surfaces 12b and 12b formed on the inner peripheral surface 12a of the outer ring 12, and rolls both raceway surfaces 11b and 12b. A plurality of spherical rolling elements 13 and a rotation detection device 1 for detecting the rotation speed (that is, wheel speed) of the inner ring 11 with respect to the outer ring 12 are provided.

A through hole is formed in the central portion of the main body 110 of the inner ring 11 along the rotation axis O, and a spline fitting portion 110a for connecting a drive shaft (not shown) is formed on the inner surface of the through hole. ing. Further, the pair of raceway surfaces 11b and 11b of the inner ring 11 are formed in parallel with each other so as to extend in the circumferential direction.

The flange portion 111 of the inner ring 11 projects outward in the radial direction of the main body portion 110 and is provided integrally with the main body portion 110. The flange portion 111 is formed with a plurality of through holes 111a into which bolts for attaching wheels (not shown) are press-fitted.

The outer ring 12 is formed in a cylindrical shape and is fixed to a knuckle 9 connected to the vehicle body by a plurality of bolts 91 (only one is shown in FIG. 1). The knuckle 9 is an example of a fixing member that rotatably supports the inner ring 11. The pair of raceway surfaces 12b, 12b of the outer ring 12 are formed parallel to each other so as to face the pair of raceway surfaces 11b, 11b of the inner ring 11 and extend in the circumferential direction. A seal 14 is arranged between the outer ring 12 and the inner ring 11 at the end of the inner ring 11 on the flange portion 111 side.

The knuckle 9 is formed with a holding hole 90 for holding the sensor unit 3 of the rotation detection device 1 described below. The holding hole 90 has a circular cross section orthogonal to the central axis, and penetrates the knuckle 9 in the radial direction of the rotation axis O.

(Explanation of rotation detection device 1)
FIG. 2 is a perspective view of the sensor unit. FIG. 3A is a side view of the sensor unit, and FIG. 3B is a cross-sectional view showing the housing in cross section. 4 (a) is a top view of the sensor unit, FIG. 4 (b) is a fracture surface view showing the housing in cross section, and FIG. 4 (c) is a top view of the magnetic sensor and the electric wire.

As shown in FIGS. 1 to 4, the rotation detection device 1 is attached to the inner ring 11 as a rotating member, and has a plurality of magnetic poles (non-magnetic poles) along the circumferential direction centered on the rotation axis (rotation axis O) of the inner ring 11. A sensor that is attached to a magnetic encoder 2 as a member to be detected and a knuckle 9 as a fixing member that does not rotate with the rotation of the inner ring 11 and is arranged so as to face the magnetic encoder 2. It is provided with a part 3.

The magnetic encoder 2 is formed in an annular shape having a thickness in a direction parallel to the rotation axis O. The magnetic encoder 2 is supported by a support member 112 fixed to the outer peripheral surface 11a of the inner ring 11, and is attached so as to rotate integrally with the inner ring 11. Further, the magnetic encoder 2 has N magnetic poles and S magnetic poles that are alternately arranged along the circumferential direction facing the sensor unit 3.

The sensor unit 3 is provided at the end of the cable 4. The cable 100 with a sensor according to the present embodiment is provided with the sensor unit 3 at the end of the cable 4. In the present embodiment, the magnetic encoder 2 and the tip of the sensor unit 3 face each other in the axial direction parallel to the rotation axis O.

In the rotation detection device 1 according to the present embodiment, the sensor unit 3 has a plurality of magnetic sensors 30 and a housing unit 31 made of a resin mold that collectively covers the plurality of magnetic sensors 30. There is. Here, a case where the sensor unit 3 has two magnetic sensors 30 will be described.

The cable 4 has a plurality of pairs (here, two pairs) of electric wires 41 corresponding to the plurality of magnetic sensors 30. Each electric wire 41 is covered with a central conductor 41a made of a stranded conductor obtained by twisting good conductive strands such as copper and an outer periphery of the central conductor 41a, and is made of an insulating resin such as cross-linked polyethylene. It has a body 41b and. Further, the cable 4 further has a sheath 42 that collectively covers two pairs (four) of electric wires 41.

At the end of the cable 4, two pairs of electric wires 41 are exposed from the sheath 42, and at the end of the electric wires 41, the central conductor 41a is exposed from the insulator 41b. The central conductor 41a exposed from the insulator 41b is electrically connected to the connection terminal 301 of the corresponding magnetic sensor 30 by resistance welding.

The magnetic sensor 30 has a detection unit 300 and a pair of connection terminals 301 extending from the detection unit 300.

The detection unit 300 includes a magnetic detection element (not shown) that detects a magnetic field from the magnetic encoder 2, a signal processing circuit (not shown) that processes a signal output from the magnetic detection element, and a magnetic detection element and a signal processing circuit. It has a resin mold 300a as a covering body that collectively covers the above. The detection unit 300 is formed in a substantially rectangular plate shape (a shape in which one of four rectangular corners is chamfered) in a plan view. The detection axis (magnetic field detection direction) of the magnetic detector element is the vertical direction (tangential direction of the circle centered on the rotation axis O) in FIG. 4A.

The pair of connection terminals 301 extend from one long side of the detection unit 300 (the long side on the side not connected to the chamfered corner) in a direction perpendicular to the long side, and both connection terminals 301. Are formed parallel to each other. In the present embodiment, both connection terminals 301 are formed in a band shape, and the central conductor 41a of the corresponding electric wire 41 is electrically connected to the tip end portion (the end portion opposite to the detection portion 300). There is.

Further, the pair of connection terminals 301 of one magnetic sensor 30 (lower magnetic sensor 30 in FIG. 3B) on the side closer to the magnetic encoder 2 is in the same direction as the extension direction of the central conductor 41a. It extends in a straight line in parallel. On the other hand, the pair of connection terminals 301 of the other magnetic sensor 30 (upper magnetic sensor 30 in FIG. 3B) on the side farther from the magnetic encoder 2 are formed by being bent into a crank shape. Specifically, the pair of connection terminals 301 of the other magnetic sensor 30 has a portion extending parallel to the extending direction of the central conductor 41a from the connection portion with the central conductor 41a, and one of the connection terminals 301 is bent from the portion. It has a portion extending in the direction of the magnetic sensor 30 (in the diagonally downward direction to the left in FIG. 3B), and further has a portion that is bent from the portion and extends in parallel with the extending direction of the central conductor 41a. ..

Although not shown, a capacitance element for suppressing noise is connected between both connection terminals 301 so as to cover the capacitance element and the connection terminal 301 of the portion connected to the capacitance element. , The capacitive element protection portion 302 formed by the resin mold is provided. The capacitive element protection unit 302 provided on the other magnetic sensor 30 is a linear pair between the pair of connection terminals 301 of one magnetic sensor 30 and the pair of connection terminals 301 of the other magnetic sensor 30. It is arranged while effectively utilizing the space created between the connection terminal 301 of the above and the pair of crank-shaped connection terminals 301.

In the rotation detection device 1 according to the present embodiment, the detection units 300 of the plurality of (two in this case) magnetic sensors 30 are stacked in the opposite direction of the sensor unit 3 and the magnetic encoder 2. Further, the detection units 30 are stacked in a direction in which the cable 4 intersects the lead-out direction derived from the housing portion 31 (in the present embodiment, the directions orthogonal to each other). Further, in the present embodiment, the magnetic sensor 30 arranged farthest from the magnetic encoder 2 has higher sensitivity than the magnetic sensor 30 arranged closest to the magnetic encoder 2. When the cable 4 is bent and the bent portion of the cable 4 is resin-molded to form an L-shaped housing portion 30, each detection portion 30 has a lead-out direction in which the cable 4 is led out from the housing portion 31. Are stacked in the same direction as.

The detection units 300 of both magnetic sensors 30 are stacked in the thickness direction thereof. That is, in the present embodiment, the opposite direction of the sensor unit 3 and the magnetic encoder 2 and the thickness direction (stacking direction) of the detection unit 300 coincide with each other. The opposite direction of the sensor unit 3 and the magnetic encoder 2 and the thickness direction (stacking direction) of the detection unit 300 do not have to be exactly the same, and may be slightly deviated. That is, "each detection unit 300 is stacked in the direction opposite to the sensor unit 3 and the magnetic encoder 2" means that the direction in which the sensor unit 3 and the magnetic encoder 2 face each other and the stacking direction of the detection unit 300 It also includes cases where the deviation is several degrees (for example, about ± 10 °).

In the present embodiment, since the magnetic encoder 2 and the tip of the sensor unit 3 face each other in the axial direction parallel to the rotation axis O, the thickness direction (stacking direction) of the detection unit 300 is one with the axial direction. I am doing it. Not limited to this, for example, when the magnetic encoder 2 and the tip of the sensor unit 3 are opposed to each other in the radial direction perpendicular to the rotation axis O, the thickness direction (stacking direction) of the detection unit 300 is set. , It is good to match in the radial direction.

Further, in the present embodiment, both detection units 300 are directly laminated. That is, the surface of one detection unit 300 and the surface of the other detection unit 300 are in contact with each other. As a result, the size can be reduced as compared with the case where the two detection units 300 are arranged apart from each other, the distance between the magnetic detection elements in both detection units 300 can be easily maintained, and the magnetic encoder 2 can be used. The detection accuracy can be improved by minimizing the distance of the magnetic sensor 30 arranged further away to the magnetic encoder 2. In the present embodiment, both detection units 300 are not adhesively fixed by an adhesive or the like, and both detection units 300 are held in the housing portion 31 in a laminated state.

Further, in both detection units 300, it is desirable that at least a part of both magnetic detection elements is laminated so as to overlap in the facing direction (axial direction) between the sensor unit 3 and the magnetic encoder 2.

By using the plurality of magnetic sensors 30, even if one magnetic sensor 30 fails, the other magnetic sensors 30 can be used to continue the detection, and the reliability of the rotation detection device 1 is improved.

Further, by stacking the detection units 300 (stacking in the thickness direction), the plurality of magnetic sensors 30 are arranged more compactly as compared with the case where the sensor units 3 are arranged side by side in the width direction perpendicular to the thickness direction, for example. This makes it possible to keep the entire sensor unit 3 compact even when a plurality of magnetic sensors 30 are used.

The thickness of the detection unit 300 is, for example, about 1 mm, but when the detection units 300 of both magnetic sensors 30 are arranged apart from each other for some reason, the distance (gap) between the sensor unit 3 and the magnetic encoder 2 is compared. If the target is large, the strength of the magnetic field detected by the magnetic sensor 30 arranged at a position away from the magnetic encoder 2 may be reduced, and the detection accuracy may be lowered.

Therefore, in the present embodiment, the sensitivity of the magnetic sensor 30 arranged farthest from the magnetic encoder 2 is made higher than the sensitivity of the magnetic sensor 30 arranged closest to the magnetic encoder 2. When two magnetic sensors 30 are used as in the present embodiment, the magnetic sensors 30 arranged on the opposite side of the magnetic encoder 2 have higher sensitivity than the magnetic sensors 30 arranged on the magnetic encoder 2 side. It will be used.

In addition, "high sensitivity" here means that the intensity of a smaller magnetic field can be detected. That is, "high sensitivity" means that the minimum value of the detectable magnetic field intensity is smaller.

In the present embodiment, the Hall IC is used as the magnetic sensor 30 arranged on the magnetic encoder 2 side, and the GMR (Giant Magneto Resistive) having higher sensitivity than the Hall IC is used as the magnetic sensor 30 arranged on the opposite side of the magnetic encoder 2. effect) A sensor was used. When a Hall IC is used as the magnetic sensor 30 arranged on the magnetic encoder 2 side, the magnetic sensor 30 arranged on the opposite side of the magnetic encoder 2 includes an AMR (Anisotropic Magneto Resistive) sensor or a TMR (Tunneling Magneto Resistive). A sensor may be used.

Further, for example, when the detection result of the rotation speed (wheel speed) of the inner ring 11 with respect to the outer ring 12 is used for the vehicle body stability control device or the indirect air pressure detection device, the rotation speed (wheel speed) of the inner ring 11 with respect to the outer ring 12 can be increased. When accurate detection is required, a GMR sensor or AMR sensor is used as the magnetic sensor 30 arranged on the magnetic encoder 2 side, and a GMR sensor 30 is used as the magnetic sensor 30 arranged on the opposite side of the magnetic encoder 2. Or a TMR sensor having a higher sensitivity than the AMR sensor may be used. For example, a GMR sensor is used as the magnetic sensor 30 arranged on the magnetic encoder 2 side, and the magnetic sensor 30 arranged on the opposite side of the magnetic encoder 2 has higher sensitivity than the GMR sensor arranged on the magnetic encoder 2 side. It is also possible to use the same type of magnetic sensor 30 having different sensitivities, such as using a high GMR sensor. The indirect air pressure detection device detects the occurrence of a flat tire on any wheel by comparing the rotation speeds (wheel speeds) of the four wheels of the vehicle.

When three or more magnetic sensors 30 are used, it is preferable that the sensitivity increases as the distance from the magnetic encoder 2 increases. More specifically, the sensitivity of the magnetic sensor 30 other than the magnetic sensor 30 arranged on the magnetic encoder 2 side is higher than the sensitivity of the magnetic sensor 30 arranged on the magnetic encoder 2 side of the magnetic sensor 30. It would be nice to have one. That is, for example, when four magnetic sensors 30 are used, Hall ICs having the same sensitivity are used as the two magnetic sensors 30 arranged closer to each other by the magnetic encoder 2, and the Hall ICs are arranged further apart from the magnetic encoder 2. It is also possible to use a GMR sensor having the same sensitivity as the magnetic sensor 30.

The housing portion 31 integrally forms a substantially cylindrical main body portion 310 that collectively covers the magnetic sensor 30 and the end portion of the cable 4, and a flange portion 311 for fixing the sensor portion 3 to the knuckle 9. It becomes. The flange portion 311 is formed with a bolt hole 312 for passing a bolt 92 (see FIG. 1) for fixing the sensor portion 3 to the knuckle 9, and the bolt hole 312 is formed on the inner peripheral surface of the bolt hole 312. Along the line, a collar 313 made of metal for suppressing deformation of the flange portion 311 when fixing the bolt is provided.

A facing surface 314 facing the magnetic encoder 2 is formed at the tip of the main body 310 of the housing 31 (the end opposite to the extending side of the cable 4). The sensor unit 3 is fixed to the knuckle 9 in a state where the facing surface 314 is opposed to the magnetic encoder 2 (a state in which the facing surface 314 is opposed to the magnetic encoder 2 in the axial direction parallel to the rotation axis O).

As the housing portion 31, for example, one made of PA (polyamide) 612, nylon 66 (nylon is a registered trademark), PBT (polybutylene terephthalate), or the like can be used. In the present embodiment, as the resin used for the housing portion 31, a resin in which a glass filler is mixed with PA612 is used.

(Modification example of cable 100 with sensor)
In the above embodiment, the cable 4 covers two pairs of electric wires 41 together with a sheath 42, but the cable 4 is not limited to this, and the cable 4 covers electric wires other than the electric wire 41 for the sensor unit 3. It may include.

In the sensor-equipped cable 100a shown in FIGS. 5A and 5B, the cable 4a has two pairs of twisted wires 43 formed by twisting a pair of wires 41, and has an outer diameter and a conductor cross-sectional area larger than those of the wires 41. A large pair of power supply wires 7, a tape member 45 spirally wound around an aggregate 44 formed by twisting both twisted wires 43 and a power supply wire 7, and a coating on the outer periphery of the tape member 45. The sheath 42 and the sheath 42 are provided.

A sensor unit 3 is provided at one end of both stranded wires 43. At the other end of both stranded wires 43, a vehicle body side sensor connector 75 for connecting to a group of electric wires in a relay box provided on the vehicle body is attached.

In the present embodiment, the power supply line 7 includes a power supply line for supplying a drive current to an electric motor (not shown) for an electric parking brake (hereinafter, EPB) mounted on a wheel of a vehicle.

EPB means that when the parking brake operation switch is operated from the off state to the on state when the vehicle is stopped, the brake pad is pressed by the electric motor by outputting the drive current to the electric motor for a predetermined time (for example, 1 second). It is an electric braking device that generates braking force on the wheels by pressing them against the disc rotor of the wheels. In EPB, when the parking brake operation switch is operated from the on state to the off state, or when the accelerator pedal is depressed, the drive current is output to the electric motor and the brake pad is moved from the disc rotor of the wheel. It is configured to be separated to release the braking force on the wheels. That is, the operating state of the EPB is maintained after the parking brake operating switch is turned on until the parking brake operating switch is turned off or the accelerator pedal is depressed.

The power supply line 7 has a power supply line center conductor 71 and a power supply line insulator 72 coated on the outer periphery of the power supply line center conductor 71. The power line center conductor 71 is made of a stranded conductor obtained by twisting good conductive strands such as copper, and the power line insulator 72 is made of an insulating resin such as cross-linked polyethylene.

A wheel-side power connector 73a for connecting to an electric motor for EPB is attached to one end of the pair of power supply lines 7, and a group of electric wires in the relay box is attached to the other end of the pair of power supply lines 7. A vehicle body side power connector 73b for connection with is attached.

The assembly 44 is formed by twisting both pairs of twisted wires 43 and a pair of power supply wires 7. In the present embodiment, the power supply line 7 is arranged between the double stranded wires 43 in the circumferential direction. In the cross section of FIG. 7B, one paired wire 43, one power supply line 7, the other paired twisted wire 43, and the other power supply line 7 are sequentially arranged in the clockwise direction.

When the power supply lines 7 are arranged so as to be adjacent to each other in the circumferential direction (when the double twisted wires 43 are arranged so as to be adjacent to each other), the center of gravity of the aggregate 44 is largely deviated from the center position of the aggregate 44. In this state, if the double-stranded wire 43 and the power supply line 7 are twisted to form the aggregate 44, the aggregate 44 will be in a twisted state as a whole. Therefore, it becomes difficult to manufacture the linear cable 4a, and there is a problem that the flexibility is lowered because a direction that is difficult to bend is generated in a part of the longitudinal direction. By configuring the anti-twisted wires 43 and the power supply wires 7 to be alternately arranged in the circumferential direction as in the present embodiment, the linear cable 4a can be easily realized and a part in the longitudinal direction. It is possible to suppress a defect such as a direction in which it is difficult to bend, and to suppress a decrease in flexibility.

The EPB basically supplies a drive current to the electric motor when the vehicle is stopped. On the other hand, the rotation detection device 1 is used when the vehicle is traveling, and the rotation detection device 1 is not used when the drive current is supplied to the power supply line 7. Therefore, in the present embodiment, the shield conductor provided around the power supply line 7 and the anti-twisted wire 43 is omitted. By omitting the shield conductor, the outer diameter of the cable 4a can be reduced as compared with the case where the shield conductor is provided, and the number of parts can be reduced to reduce the cost.

Further, in the present embodiment, the pair of stranded wires 43 that transmit electric signals when the vehicle is traveling are separated by a pair of power supply lines 7 that mainly supply a drive current to the electric motor after the vehicle is stopped. As a result, even if the shield conductor provided around the anti-twisted wire 43 is omitted, the crosstalk between the two anti-twisted wires 43 can be reduced.

A plurality of thread-like (fibrous) interpositions extending in the longitudinal direction of the cable 4a may be arranged between the double-stranded wire 43, the power supply line 7, and the tape member 45. In this case, the aggregate 44 may be formed by twisting the interposition, the double-stranded wire 43, and the power supply line 7 together. As a result, the cross-sectional shape when the tape member 45 is wound around the outer periphery of the assembly 44 can be made closer to a circular shape. As the interposition, a fibrous material such as polypropylene yarn, rayon staple fiber, aramid fiber, nylon fiber, or fibrous plastic, or paper or cotton thread can be used.

A tape member 45 is spirally wound around the assembly 44, and the tape member 45 comes into contact with all the electric wires (four electric wires 41 and a pair of power lines 7) covered by the tape member 45. ing. The tape member 45 is interposed between the assembly 44 and the sheath 42, and plays a role of reducing friction between the assembly 44 (electric wire 41 and the power supply line 7) and the sheath 42 at the time of bending. That is, by providing the tape member 45, the friction between the electric wire 41 or the power supply line 7 and the sheath 42 is reduced without using a lubricant such as talc powder, and the stress applied to the electric wire 41 or the power supply line 7 at the time of bending is reduced. It is possible to reduce the amount and improve the bending resistance.

As the tape member 45, it is desirable to use a slippery material (having a small coefficient of friction) with respect to the insulator 41b of the electric wire 41 and the power line insulator 72 of the power supply line 7, for example, non-woven fabric, paper, or the like. Alternatively, one made of a resin (resin film or the like) can be used. The tape member 45 is spirally wound around the assembly 44 so that parts of the tape member 45 in the width direction (direction perpendicular to the longitudinal direction and the thickness direction of the tape member 45) overlap. The portion where the tape members 45 overlap is not adhered by an adhesive or the like.

(Actions and effects of embodiments)
As described above, in the rotation detection device 1 according to the present embodiment, the sensor unit 3 is a magnetic detection element that detects the magnetic field from the magnetic encoder 2 and a signal processing circuit that processes the signal output from the magnetic detection element. , And a plurality of magnetic sensors 30 having a plate-shaped detector 300 having a resin mold 300a that collectively covers the magnetic detector element and the signal processing circuit, and each detector 300 includes the sensor unit 3 and magnetism. It is laminated in the direction facing the encoder 2.

As a result, the sensor unit 3 can be miniaturized even when a plurality of magnetic sensors 30 are used for redundancy or improvement of detection accuracy, and for example, a gap between the sensor unit 3 and the magnetic encoder 2 can be reduced. Even when the size is large or the stacking interval of the detection units 300 is large, detection using a plurality of magnetic sensors 30 becomes possible.

Further, in the present embodiment, the magnetic sensor 30 arranged farthest from the magnetic encoder 2 has higher sensitivity than the magnetic sensor 30 arranged closest to the magnetic encoder 2. For example, when two magnetic sensors 30 are used, it is conceivable to use both magnetic sensors 30 having sufficiently high sensitivity. However, since the magnetic sensor 30 having high sensitivity is expensive, the cost of the rotation detection device 1 increases. According to this embodiment, it is possible to realize a highly reliable rotation detection device 1 using a plurality of magnetic sensors 30 while suppressing costs.

(Summary of embodiments)
Next, the technical idea grasped from the above-described embodiment will be described with reference to the reference numerals and the like in the embodiment. However, the respective reference numerals and the like in the following description are not limited to the members and the like in which the components in the claims are specifically shown in the embodiment.

[1] The detected member (2), which is attached to the rotating member (11) and is provided with a plurality of magnetic poles along the circumferential direction about the rotation axis of the rotating member (11), and the rotating member. A sensor unit (3) that is attached to a fixing member (9) that does not rotate with the rotation of (11) and is arranged so as to face the detected member (2) is provided, and the sensor unit ( 3) includes a magnetic detection element that detects a magnetic field from the member to be detected (2), a signal processing circuit that processes a signal output from the magnetic detection element, and the magnetic detection element and the signal processing circuit. A plurality of magnetic sensors (30) having a plate-shaped detector (300) having a covering body (300a) are provided, and each of the detectors (300) is the sensor unit (3) and the sensor unit (3). A rotation detection device (1) laminated in a direction facing the member to be detected (2).

[2] The magnetic sensor (30) arranged farthest from the member to be detected (2) is larger than the magnetic sensor (30) arranged closest to the member to be detected (2). The rotation detection device (1) according to [1], which has high sensitivity.

[3] The sensor unit (3) has two magnetic sensors (30), and the magnetic sensor (30) arranged on the detected member (2) side is composed of a hall IC and is the subject. The rotation detection device (1) according to [2], wherein the magnetic sensor (30) arranged on the side opposite to the detection member (2) includes a GMR sensor, an AMR sensor, or a TMR sensor.

[4] The sensor unit (3) has two magnetic sensors (30), and the magnetic sensor (30) arranged on the detected member (2) side comprises a GMR sensor or an AMR sensor. The rotation detection device (1) according to [2], wherein the magnetic sensor (30) arranged on the side opposite to the detected member (2) comprises a TMR sensor.

[5] The detected member (2), which is attached to the rotating member (11) and has a plurality of magnetic poles provided along the circumferential direction about the rotation axis of the rotating member (11), and the rotating member. A rotation detection device (11) including a sensor unit (3) attached to a fixing member (9) that does not rotate with rotation and arranged to face the detected member (2). The sensor-equipped cable (100) used in 1), which has the cable (4) and the sensor unit (3) provided at the end of the cable (4), and has the sensor unit (3). ) Is a collective combination of the magnetic detection element that detects the magnetic field from the member to be detected (2), the signal processing circuit that processes the signal output from the magnetic detection element, and the magnetic detection element and the signal processing circuit. A plurality of magnetic sensors (30) having a plate-shaped detector (300) having a covering body (300a) are provided, and each of the detectors (300) has the sensor unit (3) and the cover. A cable with a sensor (100) laminated in a direction facing the detection member (2).

[6] The magnetic sensor (30) arranged farthest from the member to be detected (2) is larger than the magnetic sensor (30) arranged closest to the member to be detected (2). The cable with a sensor (100) according to [5], which has high sensitivity.

[7] The rotation detection device (1) detects the rotation speed of the rotating member (11) that rotates together with the wheels of the vehicle, and the cable (4) is attached to the plurality of magnetic sensors (30). The corresponding plurality of pairs of electric wires (41), the power supply line (7) for supplying a driving current to the electric motor for the electric parking brake mounted on the wheel, the plurality of pairs of electric wires (41) and the said. The cable with a sensor (100a) according to [5] or [6], comprising a sheath (42) that collectively covers the power line (7).

Although the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. It should also be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

The present invention can be appropriately modified and implemented without departing from the spirit of the present invention.

For example, in the above embodiment, the case where the rotation detection device 1 detects the wheel speed has been described, but the present invention is not limited to this, and the present invention can be applied to, for example, a drive shaft sensor, a crank angle sensor, and the like. be.

1 ... Rotation detection device 2 ... Magnetic encoder (detected member)
3 ... Sensor unit 30 ... Magnetic sensor 300 ... Detection unit 300a ... Resin mold (cover)
301 ... Connection terminal 31 ... Housing part 4 ... Cable 9 ... Knuckle (fixing member)
10 ... Wheel bearing device 11 ... Inner ring (rotating member)
12 ... Outer ring 13 ... Rolling element 100 ... Cable with sensor

Claims (6)

A rotation detection device that detects the rotation speed of a rotating member using a magnetic sensor.
The member to be detected attached to the rotating member and the member to be detected
A sensor unit attached to a fixing member that does not rotate with the rotation of the rotating member, and
With
The fixing member is formed with a through hole penetrating in a direction intersecting the rotation axis of the rotating member.
The sensor unit
A plurality of the magnetic sensors having a detection unit having a magnetic detection element and a covering body covering the magnetic detection element, and a plurality of the magnetic sensors.
A housing portion that covers the plurality of the magnetic sensors, and a housing portion that covers the plurality of magnetic sensors.
With
The housing portion is inserted into the through hole in a direction intersecting the rotation axis.
A rotation detection device in which each of the detection units is arranged side by side with the member to be detected in a direction deviated from the rotation axis and in a direction in which the housing portion intersects the insertion direction of being inserted into the through hole. The housing portion has a flange portion for fixing the sensor portion to the fixing member.
The flange portion extends in a direction in which each of the detected portions and the detected member are aligned.
The rotation detection device according to claim 1. The housing portion comprises any of polyamide, nylon and polybutylene terephthalate.
The rotation detection device according to claim 1 or 2. The magnetic sensor located farthest from the member to be detected is more sensitive than the magnetic sensor located closest to the member to be detected.
The rotation detection device according to any one of claims 1 to 3. A rotation detection device including a member to be detected attached to a rotating member and a sensor unit attached to a fixing member that does not rotate with the rotation of the rotating member, and detecting the rotation speed of the rotating member by a magnetic sensor. It is a cable with a sensor used for
With the cable
With the sensor unit provided at the end of the cable,
Have,
The fixing member is formed with a through hole penetrating in a direction intersecting the rotation axis of the rotating member.
The sensor unit
A plurality of the magnetic sensors having a detection unit having a magnetic detection element and a covering body covering the magnetic detection element, and a plurality of the magnetic sensors.
A housing portion that covers the plurality of the magnetic sensors, and a housing portion that covers the plurality of magnetic sensors.
With
The housing portion is inserted into the through hole in a direction intersecting the rotation axis.
Each of the detection units is a cable with a sensor that is arranged side by side with the member to be detected in a direction that intersects the insertion direction in which the housing portion is inserted into the through hole at a position deviated from the rotation axis. Each of the plurality of magnetic sensors has a connection terminal extending from the detection unit.
The cable has a plurality of electric wires connected to the connection terminals of the plurality of magnetic sensors.
It is provided with one connector common to the plurality of electric wires provided at the ends of the plurality of electric wires.
The cable with a sensor according to claim 5.

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