Rotation detection device and cable with sensor

Abstract

Rotation detection device (1) comprising: a detected element (2) mounted on a rotating element (11) and having multiple magnetic poles arranged circumferentially around an axis of rotation (O) of the rotating element (11); and a sensor section (3) mounted on a stationary element (9) that does not rotate with the rotation of the rotating element (11) and is arranged so that it faces the detected element (2); wherein a retaining hole (90) for holding the sensor section (3), which penetrates the stationary element (9) in a radial direction to the axis of rotation (O), is formed in the stationary element (12), wherein the sensor section (3) is inserted into the retaining hole (90) in the radial direction to the axis of rotation (O), wherein the sensor section (3) comprises: several magnetic sensors (30), each comprising a plate-shaped detection section (300) comprising a magnetism detection element for detecting a magnetic field from the detected element (2), a signal processing circuit for processing a signal output by the magnetism detection element, and a cover that jointly covers the magnetism detection element and the signal processing circuit, wherein the sensor section (3) comprises a housing section (31) that jointly covers the multiple magnetic sensors (30), wherein the detection sections (300) are stacked in a direction parallel to the axis of rotation (O) in which the sensor section (3) and the detected element (2) face each other, and wherein the sensor section (3) comprises two magnetic sensors (30), wherein the magnetic sensor (30) located furthest from the detected element (2) has a higher sensitivity than the magnetic sensor (30) located closest to the detected element (2), and wherein the magnetic sensor (30) located on a side closer to the detected element (2) comprises a Hall IC and the magnetic sensor (30) located on the side opposite the detected element (2) comprises a GMR sensor, an AMR sensor or a TMR sensor.

Description

Technical field

[0001] The present invention relates to a rotation detection device and a cable with sensor. State of the art

[0002] A rotation detection device is known which is used on a bearing unit of a wheel to detect the rotational speed of an element rotating with the wheel (see, e.g., JP 2013 - 47 636 A).

[0003] JP 2013 - 47 636 A discloses a rotation detection device comprising a detected element attached to a rotating element and having multiple magnetic poles along a circumferential direction of the rotating element, and a magnetic sensor attached to a stationary element rotatably supporting the rotating element and having a detection element for detecting a magnetic field of the detected element.

[0004] DE 10 2005 060 713 A1 discloses a magnetic field sensor arrangement comprising a stacked arrangement of a first and a second magnetic field sensor body.

[0005] US 2009 / 0 058 407 A1 describes a sensor for converting physical quantities with redundant sensor elements that can be arranged in a common housing, for example, stacked.

[0006] German patent DE 10 2015 202 333 A1 discloses a wheel speed sensor device in which a first and a second speed sensor are arranged together in a sensor housing. US patent 2013 / 0277087 A1 relates to a wiring harness for vehicles.

[0007] DE 695 06 755 T2 discloses a device for determining the rotational speed of a rolling bearing, which has a sensor block that is mounted in a radial bore of a support.

[0008] DE 10 2005 022 596 A1 describes an arrangement for wheel speed detection with two signal paths that have different sensitivities.

[0009] EP 2 772 728 A1 shows a detection sensor in which several sensor elements are held with their bodies overlapping in a housing. Summary of the invention: Technical problem

[0010] Rotation detection devices for measuring the rotational speed of a wheel should have multiple magnetic sensors so that the rotational speed of the wheel can be detected even in the event of a failure, etc., of a particular magnetic sensor, or so that the rotational speed of the wheel can be detected more accurately.

[0011] When multiple magnetic sensors are attached to a sensor section, the overall size of the sensor section increases, which can cause problems such as making it impossible to insert the sensor section into a sensor section mounting hole. Therefore, there is a need for a sensor section that can maintain a small size even when multiple magnetic sensors are mounted.

[0012] It is an object of the invention to provide a rotation detection device and a cable with a sensor, in which a sensor section can have several magnetic sensors while being of a small size. Solution to the problem

[0013] The invention is defined in the independent claims.

[0014] The dependent claim defines an embodiment of the invention. Advantageous effects of the invention

[0015] According to one aspect of the invention, a rotation detection device and a cable with a sensor are provided, in which a sensor section can have several magnetic sensors at a small size. Brief description of the drawings Fig. Figure 1 is a cross-sectional view showing a rotation detection device in an embodiment of the present invention and a vehicle wheel bearing device with the rotation detection device. Fig. Figure 2 is a perspective view showing a sensor section. Fig. 3A is a side view showing the sensor section. Fig. 3B is a cross-sectional view of Fig. 3A, in which a housing is shown as a cross-section Fig. 4A is a top view showing the sensor section. Fig. 4B is a cross-sectional view of Fig. 4A, in which the housing is shown as a cross-section. Fig. 4C is a top view showing a magnetic sensor and electrical wires. Fig. Figure 5A is an explanatory illustration showing a cable with a sensor in a modification of the invention. Fig. 5B is a cross-sectional view showing the Fig. 5A represents the cable shown. Description of embodiments (design form)

[0016] One embodiment of the invention is described below in conjunction with the accompanying drawings. (Configuration of wheel bearing device 10)

[0017] Fig. Figure 1 is a cross-sectional view showing a rotation detection device in the present embodiment and a vehicle wheel bearing device with the rotation detection device.

[0018] The wheel bearing device 10 is provided with an inner running ring 11 as a rotating element with a cylindrical main body 110 and a flange 111 to be attached to a wheel, an outer running ring 12 which is arranged on the outer circumferential side of the main body 110 of the inner running ring 11, several spherical rolling elements 13 which are arranged between a pair of running surfaces 11b, 11b which are formed on an outer surface 11a of the inner running ring 11, and a pair of running surfaces 12b, 12b which are formed on an inner surface 12a of the outer running ring 12 and which roll and move on the running surfaces 11b and 12b, and a rotation detection device 1 for detecting a rotational speed of the inner running ring 11 in relation to the outer running ring 12 (i.e. a wheel rotational speed).

[0019] A through-hole is formed in the central section of the main body 110 of the inner race 11 along a rotation axis O thereof, and a splined shaft section 110a for coupling a drive shaft (not shown) is formed on an inner surface of the through-hole. The pair of raceways 11b, 11b of the inner race 11 are parallel to each other and extend in a circumferential direction.

[0020] The flange 111 of the inner race 11 is integrally formed with the main body 110 such that it projects radially outwards from the main body 110. The flange 111 has several through holes 111a into which bolts for attachment to a wheel (not shown) are pressed.

[0021] The outer running ring 12 is formed in a cylindrical shape and is fastened by several screws 91 (only one screw 91 is in Fig. (1 shown) is attached to a steering knuckle 9, which is connected to a vehicle body. The steering knuckle 9 is an example of the stationary element that rotatably supports the inner race 11. The pair of running surfaces 12b, 12b of the outer race 12 are parallel to each other and extend in a circumferential direction such that they face the pair of running surfaces 11b, 11b of the inner race 11. At one end of the outer race 12, on the side where the flange 111 of the inner race 11 is located, a seal 14 is arranged between the inner race 11 and the outer race 12.

[0022] A retaining hole 90 for holding a sensor section 3 of the rotation detection device 1 (described next) is formed on the steering knuckle 9. The retaining hole 90 has a circular cross-section perpendicular to its central axis and penetrates the steering knuckle 9 in a radial direction from the axis of rotation O. (Rotation detection device 1).

[0023] Fig. Figure 2 is a perspective view showing a sensor section. Fig. 3A is a side view showing the sensor section, and Fig. Figure 3B is a sectional view of it, showing a housing as a cross-section. Fig. 4A is a top view showing the sensor section; Fig. 4B is a sectional view of it, showing the housing as a cross-section, and Fig. 4C is a top view showing a magnetic sensor and electrical wires.

[0024] As in Fig. Figures 1 to 4 show the rotation detection device 1 with a magnetic sensor 2 as the detected element, which is attached to the inner running ring 11 as a rotating element and has several magnetic poles (not shown) arranged in a circumferential direction around an axis of rotation (the axis of rotation line O) of the inner running ring 11, and a sensor section 3, which is mounted on the axle 9 as a stationary element that does not rotate with the rotation of the inner running ring 11 and is arranged so that it faces the magnetic sensor 2.

[0025] The magnetic encoder 2 is formed in a ring shape with a thickness in one direction parallel to the axis of rotation O. The magnetic encoder 2 is supported by a support element 112, which is fixed to the outer surface 11a of the inner running ring 11, and is mounted such that it rotates together with the inner running ring. Additionally, the magnetic encoder 2 has N-poles and S-poles facing the sensor section 3, which are arranged alternately along the circumferential direction.

[0026] The sensor section 3 is provided at one end of a cable 4. The cable 4 with the sensor section 3 at one end is a cable with a sensor 100 in the present embodiment. In the present embodiment, the magnetic encoder 2 and a tip of the sensor section 3 face each other in an axial direction parallel to the axis of rotation O.

[0027] In the rotation detection device 1 of the present embodiment, the sensor section 3 comprises several magnetic sensors 30 and a housing section 31 formed from a resin mold that covers the several magnetic sensors 30 together. In this example, the sensor section 3 is described with two magnetic sensors 30.

[0028] The cable 4 has several pairs (in this example, two pairs) of electrical wires 41, corresponding to the several magnetic sensors 30. Each electrical wire 41 has a central conductor 41a, formed from a stranded conductor created by twisting together highly conductive copper strands, and insulation 41b, formed from an insulating resin such as cross-linked polyethylene, covering the outer surface of the central conductor 41a. The cable 4 also has a sheath 42, which covers two pairs of electrical wires 41 (four electrical wires 41 in total).

[0029] The two pairs of electrical wires 41 are exposed at one end of the cable 4 from the sheathing 42, and the center conductors 41a are further exposed at one end of the electrical wires 41 from the insulation 41b. The center conductor 41a, exposed from the insulation 41b, is electrically connected to a connection terminal 301 of the corresponding magnetic sensor 30 by resistance welding.

[0030] The magnetic sensor 30 has a detection section 300 and a pair of connection terminals 301 extending from the detection section 300.

[0031] The detection section 300 comprises a magnetism detection element (not shown) for detecting a magnetic field from the magnet transmitter 2, a signal processing circuit (not shown) for processing a signal output by the magnetism detection element, and a resin mold 300a as a cover that jointly covers the magnetism detection element and the signal processing circuit. In a top view, the detection section 300 is formed in a substantially rectangular plate shape (a rectangular shape in which one of the four corners is chamfered). The detection axis of the magnetism detection element (magnetic field detection direction) is the vertical direction in Fig. 4A (one direction of a tangent to a circle with a center on the axis of rotation O).

[0032] The pair of connecting terminals 301 extends from a long side of the detection section 300 (a long side not connected to the chamfered corner) in a direction perpendicular to the long side, and the two connecting terminals 301 are parallel to each other. In the present embodiment, the two connecting terminals 301 are in a strip shape, and tips thereof are electrically connected to the center conductors 41a of the corresponding electrical wires 41.

[0033] The pair of connection terminals 301 of a magnetic sensor 30, which is located closer to the magnetic transmitter 2, (of the magnetic sensor 30, which is located in the in Fig. (as shown in the example 3B on the lower page) extend linearly and parallel to each other in the same direction as the center conductors 41a. On the other hand, the pair of connecting terminals 301 of the other magnetic sensor 30, which is located further away from the magnetic transmitter 2, (of the magnetic sensor 30 which is located in the one shown in Fig. (as shown in example 3B, arranged on the upper side), bent into a crank shape. Specifically, the pair of connecting terminals 301 of the other magnetic sensor 30 has a section extending horizontally from a connection to the center conductors 41a in the same direction as the center conductors 41a, and a section bent away from the horizontal section and extending to the one magnetic sensor 30 (in which in Fig. 3B (example shown diagonally downwards to the left) and a section which is bent away from the diagonal section and extends horizontally in the same direction as the center conductor 41a.

[0034] Although not shown in the drawings, a capacitive element for noise suppression is connected between the two connection terminals 301, and a protective section for the capacitive element 302, formed from a resin mold, is provided to cover the capacitive element and a section of the connection terminals 301 connected to the capacitive element. The protective section for the capacitive element 302, provided at the other magnetic sensor 30, is positioned 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, effectively utilizing a space formed between the pair of linear connection terminals 301 and the pair of crank-shaped connection terminals 301.

[0035] The rotation detection device 1 of the present embodiment comprises the detection sections 300 of several (in this example, two) magnetic sensors 30 stacked in a direction along which the sensor section 3 and the magnetic transmitter 2 face each other. Furthermore, the detection sections 300 are stacked in a direction that intersects (orthogonally in the present embodiment) with an exit direction along which the cable 4 exits the housing section 31. Additionally, in the present embodiment, the magnetic sensor 30 located furthest from the magnetic transmitter 2 has a higher sensitivity than the magnetic sensor 30 located closest to the magnetic transmitter 2.When the cable 4 is bent and an L-shaped housing section 31 is formed by molding a resin with the bent section of the cable 4, the detection sections 300 are stacked in the same direction as the exit direction along which the cable 4 is led out of the housing section 31.

[0036] The detection sections 300 of the two magnetic sensors 30 are stacked in a direction of thickness. That is, in the present embodiment, the direction in which the sensor section 3 and the magnetic transmitter 2 face each other coincides with the thickness direction (stacking direction) of the detection sections 300. The direction along which the sensor section 3 and the magnetic transmitter 2 face each other need not coincide exactly with the thickness direction (stacking direction) of the detection sections 300 and may deviate slightly. In other words, "the detection sections 300 are stacked in a direction along which the sensor section 3 and the magnetic transmitter 2 face each other" includes the case in which the direction along which the sensor section 3 and the magnetic transmitter 2 face each other deviates, for example, by a few degrees (e.g., ± 10°) from the stacking direction of the detection sections 300.

[0037] In the present embodiment, since the magnetic encoder 2 and the tip of the sensor section 3 face each other in the axial direction parallel to the axis of rotation O, the thickness direction (stacking direction) of the detection sections 300 coincides with the axial direction. However, there is no restriction on this. For example, if the magnetic encoder 2 and the tip of the sensor section 3 face each other in a radial direction perpendicular to the axis of rotation O, the thickness direction (stacking direction) of the detection sections 300 coincides with the radial direction.

[0038] In addition, in the present embodiment, the two detection sections 300 are directly stacked. In other words, a surface of one detection section 300 is in contact with a surface of the other detection section 300. Thus, the size can be smaller, and the distance between the magnetism detection elements of the two detection sections 300 can be more easily kept constant than in the case where the two detection sections 300 are arranged at a distance. Furthermore, the detection accuracy can be improved because the distance between the magnetic transmitter 2 and the magnetic sensor 30, which is located further away from the magnetic transmitter 2, is minimized. In the present embodiment, the two detection sections 300 are not connected / fixed by an adhesive, etc., and the two detection sections 300 are contained in a stacked state in the housing section 31.

[0039] In addition, the two detection sections 300 are preferably stacked such that the two magnetism detection elements overlap at least partially in the direction in which the sensor section 3 and the magnet transmitter 2 are facing each other (in the axial direction).

[0040] Even if one magnetic sensor 30 fails, it is possible to continue detection by one or more other magnetic sensors 30, since multiple magnetic sensors 30 are used, thereby improving the reliability of the rotation detection device 1.

[0041] Additionally, by stacking the detection sections 300 (stacking in the thickness direction), it is possible to arrange the multiple magnetic sensors 30 more compactly compared to the case where, for example, the sensor section 3 is arranged side by side in a width direction perpendicular to the thickness direction. Therefore, the size of the entire sensor section 3 can be kept small even when multiple magnetic sensors 30 are used.

[0042] The thickness of the detection section 300 is, for example, approximately 1 mm. However, if the detection sections 300 of the two magnetic sensors 30 are arranged at a distance for any reason, or if the distance (gap) between the sensor section 3 and the magnetic transmitter 2 is relatively large, the magnetic field strength detected by the magnetic sensor 30 located furthest from the magnetic transmitter 2 could become small, resulting in a reduction in detection accuracy.

[0043] Based on this, in the present embodiment, the sensitivity of the magnetic sensor 30 located furthest from the magnetic transmitter 2 is higher than the sensitivity of the magnetic sensor 30 located closest to the magnetic transmitter 2. When using two magnetic sensors 30 as in the present embodiment, a magnetic sensor with a higher sensitivity than the magnetic sensor 30 located on the side of the magnetic transmitter 2 is used as the magnetic sensor 30 located on the side opposite the magnetic transmitter 2.

[0044] "Higher sensitivity" here means being able to detect a lower magnetic field strength. In other words, "higher sensitivity" means that the minimum detectable magnetic field strength is lower.

[0045] In the present embodiment, a Hall-effect IC is used as a magnetic sensor 30 arranged on the side of the magnetic encoder 2, and a GMR sensor (giant magnetoresistance sensor) with a higher sensitivity than the Hall-effect IC is used as a magnetic sensor 30 arranged on the side opposite the magnetic encoder 2. Alternatively, when the Hall-effect IC is used as the magnetic sensor 30 on the side of the magnetic encoder 2, an AMR sensor (anisotropic magnetoresistance sensor) or a TMR sensor (tunnel magnetoresistance sensor) can be used as the magnetic sensor 30 arranged on the side opposite the magnetic encoder 2.

[0046] Additionally, if a more precise detection of the rotational speed of the inner running ring 11 relative to the outer running ring 12 (a wheel rotation) is required, such as when a detection result of the rotational speed of the inner running ring 11 relative to the outer running ring 12 (the wheel rotation) is to be used for a vehicle body stability control system or an indirect air pressure detection device, a GMR sensor or an AMR sensor can be used as a magnetic sensor 30 located on the side of the magnetic encoder 2, while a TMR sensor with a higher sensitivity than the GMR sensor or AMR sensor can be located as a magnetic sensor 30 on the side opposite the magnetic encoder 2.Alternatively, it is also possible to use the same type of magnetic sensor 30 with different sensitivities in such a way that, for example, one GMR sensor is used as the magnetic sensor 30 located on the side of the magnetic transmitter 2, and another GMR sensor with a higher sensitivity than the one located on the side of the magnetic transmitter 2 is used as the magnetic sensor 30 located on the opposite side of the magnetic transmitter 2. The indirect air pressure detection device is, in this context, a device that compares the rotational speeds of four wheels (wheel speeds) of a vehicle and thereby detects a breakdown, etc., that has occurred at a given wheel.

[0047] If at least three magnetic sensors 30 are used, the sensitivity of the magnetic sensor 30 located further away from the magnetic transmitter 2 is higher. More precisely, all magnetic sensors 30 except the one located closest to the magnetic transmitter 2 have a sensitivity greater than or equal to that of the magnetic sensor(s) 30 located closer to the magnetic transmitter 2. That is, if, for example, four magnetic sensors 30 are used, it is possible to use Hall-effect ICs with the same sensitivity as two magnetic sensors located closer to the magnetic transmitter 2 and GMR sensors with the same sensitivity as two magnetic sensors 30 located further away from the magnetic transmitter 2.

[0048] The housing section 31 incorporates an essentially cylindrical main body 310, which jointly covers the magnetic sensor 30 and one end of the cable 4, and a flange 311 for attaching the sensor section 3 to the steering knuckle 9. A bolt hole 312 for inserting a bolt 92 (see Fig. 1), which is used to fix the sensor section 3 to the steering knuckle 9, is formed on the flange 311 and a metal collar 313 to prevent deformation of the flange 311 due to the bolt fixing is provided at the bolt hole 312 along the inner surface of the bolt hole 312.

[0049] A facing surface 314, which is oriented towards the magnetic encoder 2, is formed on a tip section (an end section opposite the side from which the cable 4 emerges) of the main body 310 of the housing section 31. The sensor section 3 is fixed to the axle 9 in a state in which the facing surface 314 is oriented towards the magnetic encoder 2 (pointing in the axial direction parallel to the axis of rotation O).

[0050] It is possible to use a housing section 31 made, for example, of PA (polyamide) 612, Nylon 66 (Nylon is a registered trademark), or PBT (polybutylene terephthalate), etc. In the present embodiment, PA 612 mixed with glass filler is used as the resin to form the housing section 31. (Modification of the cable with sensor 100)

[0051] Although in this embodiment the cable 4 is formed by jointly covering two pairs of electrical wires 41 with the sheathing 42, it is not limited to this. The cable 4 can contain electrical wires other than the electrical wires 41 for the sensor section 3.

[0052] In a cable with sensor 100a, which is in Fig. 5A and Fig. Figure 5B shows a cable 4a with two twisted double conductors 43, each formed by twisting a pair of electrical wires 41, a pair of power wires 7 with a larger outer diameter and conductor cross-sectional area than the electrical wire 41a, the tape element 45 which is wound spirally around an assembled article 44 formed by twisting the twisted double conductors 43 and the power wires 7, and a sheathing 42 which covers the outer surface of the tape element 45.

[0053] The sensor section 3 is provided at one end of the two twisted pairs of wires 43. A vehicle body-side sensor connector 75 for connection to a wire group within a junction box provided on the body of a vehicle is attached to the other end of the two twisted pairs of wires.

[0054] In the present embodiment, the power cables 7 are used to supply a drive current to a motor (not shown) for an electric parking brake (hereinafter referred to as “EPB”) which is mounted on a wheel of the vehicle.

[0055] EPB is an electric braking system designed to supply a drive current to the motor for a predetermined period (e.g., 1 second) when a parking brake activation switch is moved from an OFF state to an ON state while the vehicle is stationary. This presses the brake pads against the wheel's disc rotor, generating a braking force applied to the wheel. The EPB is also designed to supply a drive current to the motor when the parking brake activation switch is moved from the ON state to the OFF state, or when the accelerator pedal is depressed, thus releasing the brake pads from the wheel's disc rotor and disengaging the braking force from the wheel.In other words, the configuration is such that an operating state of the EPB is maintained from the time the parking brake activation switch is turned on until the time the parking brake activation switch is turned off or the accelerator pedal is pressed down.

[0056] The power wire 7 has a power wire center conductor 71 and a power wire insulation 72 that covers the power wire center conductor 71. The power wire center conductor 71 is made of a stranded conductor formed by twisting highly conductive copper strands, etc., and the power wire insulation 72 is made of an insulating resin such as cross-linked polyethylene.

[0057] A wheel-side power connector 73a for connection to the EPB motor is attached to one end of the pair of power wires 7, and a vehicle body-side power connector 73b for connection to the wire group inside the junction box is attached to the other end of the pair of power wires 7.

[0058] The assembled article 44 is formed by twisting together the two twisted double conductors 43 and the pair of power wires 7. In the present embodiment, the power wires 7 are arranged circumferentially between the two twisted double conductors 43. In the Fig. In the cross-section shown in 5A, one of the twisted twin conductors 43, one of the power wires 7, the other twisted twin conductor 43 and the other power wire 7 are arranged in this order in a clockwise direction.

[0059] If the power wires 7 are arranged adjacent to each other in the circumferential direction (if the two twisted double wires 43 are arranged adjacent to each other), the center of gravity of the assembled article 44 shifts considerably away from the central position of the assembled article 44, and the composite article 44, formed by twisting the two twisted double wires 43 and the power wires 7, is completely distorted in such a state. In this case, it is difficult to produce a straight cable 4a, and there is also the problem that the cable is not flexible in some directions in some sections along a longitudinal direction, resulting in a decrease in flexibility.By alternately arranging the twisted double conductors 43 and the power wires 7 in the circumferential direction as in the present embodiment, it is easily possible to realize the straight cable 4a and also to suppress a decrease in flexibility, since a defect such as inflexibility in some directions is prevented on some sections in the longitudinal direction.

[0060] In the EPB, a drive current is essentially supplied to the motor when the vehicle is stationary. Conversely, the rotation detection device 1 is used when the vehicle is in motion, and the rotation detection device 1 is not used while the drive current is supplied through the power wires 7. Therefore, in the present embodiment, a shielding conductor around the power wires 7 or the twisted pairs 43 is omitted. Omitting the shielding conductor allows the cable 4a to have a smaller outer diameter than when the shielding conductor is provided and also reduces the number of components, thereby reducing costs.

[0061] In addition, in the present embodiment, the two twisted pairs 43, which transmit an electrical signal during the vehicle's movement, are separated by the pair of power wires 7, which primarily supply a drive current to the motor after the vehicle has stopped. This can reduce crosstalk between the two twisted pairs 43 even if shielding conductors around the twisted pairs 43 are omitted.

[0062] Several thread-like (fibrous) fillers extending longitudinally along the cable 4a can be arranged between the twisted twin conductors 43 or the power wires 7 and the tape element 45. In this case, the assembled article 44 is formed by twisting the fillers together with the twisted twin conductors 43 and the power wires 7. Thus, the cross-sectional shape after winding the tape element 45 around the assembled article 44 can be more circular. It is possible to use a fibrous material as the filler, such as polypropylene yarn, staple fiber yarn (rayon staple fiber), aramid fiber, nylon fiber or fiber-reinforced plastic, paper, or cotton yarn.

[0063] The tape element 45 is wound spirally around the assembled article 44. The tape element is in contact with all electrical wires (four electrical wires 41 and one pair of power wires 7) that are covered by the tape element 45. The tape element 45 is positioned between the assembled article 44 and the sheathing 42 and serves to reduce the friction between the assembled article 44 (the electrical wires 41 and the power wires 7) and the sheathing 42 during bending. In other words, providing the tape element 45 reduces the friction between the electrical wires 41 and the power wires 7 and the sheathing 42 without the need for a lubricant such as talc powder, thus reducing the mechanical stress exerted on the electrical wires 41 and the power wires 7 during bending and thereby improving the bending stiffness.

[0064] It is desirable to use a strip element 45 that is sliding (has a low coefficient of friction) with respect to the insulation 41b of the electrical wire 41 or the power wire insulation 72 of the power wire 7, and it is possible to use a strip element 45 made, for example, of a nonwoven fabric, paper, or resin (resin film, etc.). The strip element 45 is wound spirally around the assembled article 44 to overlap at one section in a width direction (a direction perpendicular to the length and thickness direction of the strip element 45). The overlapping section of the strip element 45 is not bonded by an adhesive, etc. (Functions and effects of the embodiment)

[0065] As described above, in the rotation detection device 1 of the present embodiment, the sensor section 3 is provided with several magnetic sensors 30, each of which provides the plate-shaped detection section 300 with a magnetism detection element for detecting a magnetic field from the magnet generator 2, a signal processing circuit for processing a signal output by the magnetism detection element, and the resin mold 300a, which jointly covers the magnetism detection element and the signal processing circuit, and the detection sections 300 are stacked in a direction in which the sensor section 3 and the magnet generator 2 face each other.

[0066] Because of this configuration, the sensor section 3 can be small even when multiple magnetic sensors 30 are used to provide redundancy or to improve detection accuracy. Even if, for example, the gap between the sensor section 3 and the magnetic transmitter 2 is large, or the stacking interval of the detection sections 300 is large, it is still possible to perform detection using multiple magnetic sensors 30.

[0067] In addition, in the present embodiment, the magnetic sensor 30 located furthest from the magnetic encoder 2 has a higher sensitivity than the magnetic sensor 30 located closest to the magnetic encoder 2. For example, if two magnetic sensors 30 were used, sensors with sufficiently high sensitivity could be employed for both magnetic sensors 30. However, in this case, the cost of the rotation detection device 1 would increase, since the highly sensitive magnetic sensor 30 would be expensive. According to the present embodiment, a very reliable rotation detection device 1 can be implemented using multiple magnetic sensors 30, while simultaneously reducing costs. (Summary of embodiments)

[0068] Technical ideas evident from the embodiment are described below with reference to the reference numerals, etc., used for the embodiment. However, it is not the case that each of the reference numerals, etc., described below limits the elements in the claims to those elements, etc., specifically described in the embodiment.

[0069] [1] A rotation detection device (1) comprising: a detected element (2) mounted on a rotating element (11) and having multiple magnetic poles arranged in a circumferential direction around an axis of rotation of the rotating element (11);and a sensor section (3) mounted on a stationary element (9) that does not rotate with the rotation of the rotating element (11) and is arranged to face the detected element (2), the sensor section (3) comprising: several magnetic sensors (30), each comprising a plate-shaped detection section (300) comprising a magnetism detection element for detecting a magnetic field from the detected element (2), a signal processing circuit for processing a signal output by the magnetism detection element, and a cover (300a) that jointly covers the magnetism detection element and the signal processing circuit, and the detection sections (300) are stacked in a direction in which the sensor section (3) and the detected element (2) face each other.

[0070] [2] The rotation detection device (1) defined by [1], wherein the magnetic sensor (30) located furthest from the detected element (2) has a higher sensitivity than the magnetic sensor (30) located closest to the detected element (2).

[0071] [3] The rotation detection device (1) defined by [2], wherein the sensor section (3) comprises the two magnetic sensors (30), the magnetic sensor (30) located on a side closer to the detected element (2) comprising a Hall IC, and the magnetic sensor (30) located on the side opposite the detected element (2) comprising a GMR sensor, an AMR sensor or a TMR sensor.

[0072] [4] The rotation detection device (1) defined by [2], wherein the sensor section (3) comprises the two magnetic sensors (30), the magnetic sensor (30) located on a side closer to the detected element (2) comprising a GMR sensor or an AMR sensor, and the magnetic sensor (30) located on the side opposite the detected element (2) comprising a TMR sensor.

[0073] [5] A cable with sensor (100) used for a rotation detection device (1) comprising a detected element (2) mounted on a rotating element (11) and having multiple magnetic poles arranged in a circumferential direction around an axis of rotation of the rotating element (11), and a sensor section (3) mounted on a stationary element (9) that does not rotate with the rotation of the rotating element (11) and is arranged to face the detected element (2), wherein the cable with sensor (100) comprises: a cable (4);and the sensor section (3) provided at one end of the cable (4), wherein the sensor section (3) comprises several magnetic sensors (30), each comprising a plate-shaped detection section (300) comprising a magnetism detection element for detecting a magnetic field from the detected element (2), a signal processing circuit for processing a signal output by the magnetism detection element, and a cover (300a) that jointly covers the magnetism detection element and the signal processing circuit, and the detection sections (300) are stacked in a direction along which the sensor section (3) and the detected element (2) face each other.

[0074] [6] The cable with sensor (100) defined by [5], wherein the magnetic sensor (30) located furthest from the detected element (2) has a higher sensitivity than the magnetic sensor (30) located closest to the detected element (2).

[0075] [7] The cable with sensor (100a) defined by [5] or [6], wherein the rotation detection device (1) is used to detect a rotational speed of the rotating element (11) which rotates with the wheel of a vehicle, and the cable (4) comprises several pairs of electrical wires (41) corresponding to the several magnetic sensors (30), power wires (7) for supplying a drive current to a motor for an electric parking brake mounted on the wheel, and a sheath (42) covering the several pairs of electrical wires (41) and the power wires (7).

[0076] Although the embodiment of the invention has been described, the invention according to the claims is not limited to the embodiment described above. Furthermore, it should be noted that not all combinations of the features described in the embodiment are necessary to solve the problem of the invention.

[0077] The invention can be modified and implemented in a suitable manner without deviating from its core.

[0078] Although, for example, the rotation detection device 1, which detects a wheel rotation speed, has been described in this embodiment, it is not limited to this. The invention is applicable, for example, to a drive shaft sensor or a crank angle sensor, etc. Reference symbol list 1 Rotation Detection Device 2 MAGNETIC TRANSMITTERS (DETECTED ELEMENT) 3 SENSOR SECTION 30 MAGNETIC SENSOR 300 DETECTION SECTION 300a RESIN FORM (COVER) 301 CONNECTION LINK 31 HOUSING SECTION 4 CABLES 9 AXLE KNOB (STATIONARY ELEMENT) 10 WHEEL BEARING DEVICE 11 INNER RUNNING RING (ROTATING ELEMENT) 12 OUTER RUNNING RING 13 ROLLING ELEMENT 100 Cables with Sensor

Claims

[1] Rotation detection device (1) comprising: a detected element (2) mounted on a rotating element (11) and having multiple magnetic poles arranged circumferentially around an axis of rotation (O) of the rotating element (11); and a sensor section (3) mounted on a stationary element (9) that does not rotate with the rotation of the rotating element (11) and is arranged so that it faces the detected element (2); wherein a retaining hole (90) for holding the sensor section (3), which penetrates the stationary element (9) in a radial direction to the axis of rotation (O), is formed in the stationary element (12), wherein the sensor section (3) is inserted into the retaining hole (90) in the radial direction to the axis of rotation (O), wherein the sensor section (3) comprises: several magnetic sensors (30), each comprising a plate-shaped detection section (300) comprising a magnetism detection element for detecting a magnetic field from the detected element (2), a signal processing circuit for processing a signal output by the magnetism detection element, and a cover that jointly covers the magnetism detection element and the signal processing circuit, wherein the sensor section (3) comprises a housing section (31) that jointly covers the multiple magnetic sensors (30), wherein the detection sections (300) are stacked in a direction parallel to the axis of rotation (O) in which the sensor section (3) and the detected element (2) face each other, and wherein the sensor section (3) comprises two magnetic sensors (30), wherein the magnetic sensor (30) located furthest from the detected element (2) has a higher sensitivity than the magnetic sensor (30) located closest to the detected element (2), and wherein the magnetic sensor (30) located on a side closer to the detected element (2) comprises a Hall IC and the magnetic sensor (30) located on the side opposite the detected element (2) comprises a GMR sensor, an AMR sensor or a TMR sensor. [2] Rotation detection device (1) comprising: a detected element (2) mounted on a rotating element (11) and having multiple magnetic poles arranged circumferentially around an axis of rotation (O) of the rotating element (11); and a sensor section (3) mounted on a stationary element (9) that does not rotate with the rotation of the rotating element (11) and is arranged so that it faces the detected element (2); wherein a retaining hole (90) for holding the sensor section (3), which penetrates the stationary element (9) in a radial direction to the axis of rotation (O), is formed in the stationary element (12), wherein the sensor section (3) is inserted into the retaining hole (90) in the radial direction to the axis of rotation (O), wherein the sensor section (3) comprises: several magnetic sensors (30), each comprising a plate-shaped detection section (300) comprising a magnetism detection element for detecting a magnetic field from the detected element (2), a signal processing circuit for processing a signal output by the magnetism detection element, and a cover that jointly covers the magnetism detection element and the signal processing circuit, wherein the sensor section (3) comprises a housing section (31) that jointly covers the multiple magnetic sensors (30), wherein the detection sections (300) are stacked in a direction parallel to the axis of rotation (O) in which the sensor section (3) and the detected element (2) face each other, and wherein the sensor section (3) comprises two magnetic sensors (30), wherein the magnetic sensor (30) located furthest from the detected element (2) has a higher sensitivity than the magnetic sensor (30) located closest to the detected element (2), and wherein the magnetic sensor (30) located on a side closer to the detected element (2) comprises a GMR sensor or an AMR sensor, and the magnetic sensor (30) located on the side opposite the detected element (2) comprises a TMR sensor. [3] Cable with sensor (100) used for a rotation detection device (1) comprising a detected element (2) mounted on a rotating element and having multiple magnetic poles arranged in a circumferential direction around an axis of rotation (O) of the rotating element (11), and a sensor section (3) mounted on a stationary element (9) that does not rotate with the rotation of the rotating element (11) and is arranged to face the detected element (2), wherein the cable with sensor (100) comprises: a cable (4); and the sensor section (3) which is provided at one end of the cable (4), wherein a retaining hole (90) for holding the sensor section (3), which penetrates the stationary element (9) in a radial direction to the axis of rotation (O), is formed in the stationary element (9), wherein the sensor section (3) is inserted into the retaining hole (90) in the radial direction to the axis of rotation (O), wherein the sensor section (3) comprises several magnetic sensors (30), each comprising a plate-shaped detection section (300) which includes a magnetism detection element for detecting a magnetic field from the detected element (2), a signal processing circuit for processing a signal output by the magnetism detection element, and a cover which jointly covers the magnetism detection element and the signal processing circuit, wherein the sensor section (3) comprises a housing section (31) which jointly covers the multiple magnetic sensors (30), wherein the detection sections (300) are stacked in a direction parallel to the axis of rotation (O) along which the sensor section (3) and the detected element (2) face each other, and wherein the sensor section (3) comprises two magnetic sensors (30), wherein the magnetic sensor (30) located furthest from the detected element (2) has a higher sensitivity than the magnetic sensor (30) located closest to the detected element (2), and wherein the magnetic sensor (30) located on a side closer to the detected element (2) comprises a Hall IC and the magnetic sensor (30) located on the side opposite the detected element (2) comprises a GMR sensor, an AMR sensor or a TMR sensor. [4] Cable with sensor (100) used for a rotation detection device (1) comprising a detected element (2) mounted on a rotating element and having multiple magnetic poles arranged in a circumferential direction around an axis of rotation (O) of the rotating element (11), and a sensor section (3) mounted on a stationary element (9) that does not rotate with the rotation of the rotating element (11) and is arranged to face the detected element (2), wherein the cable with sensor (100) comprises: a cable (4); and the sensor section (3) which is provided at one end of the cable (4), wherein a retaining hole (90) for holding the sensor section (3), which penetrates the stationary element (9) in a radial direction to the axis of rotation (O), is formed in the stationary element (9), wherein the sensor section (3) is inserted into the retaining hole (90) in the radial direction to the axis of rotation (O), wherein the sensor section (3) comprises several magnetic sensors (30), each comprising a plate-shaped detection section (300) which includes a magnetism detection element for detecting a magnetic field from the detected element (2), a signal processing circuit for processing a signal output by the magnetism detection element, and a cover which jointly covers the magnetism detection element and the signal processing circuit, wherein the sensor section (3) comprises a housing section (31) which jointly covers the multiple magnetic sensors (30), wherein the detection sections (300) are stacked in a direction parallel to the axis of rotation (O), along which the sensor section (3) and the detected element (2) are oriented towards each other, and wherein the sensor section (3) comprises two magnetic sensors (30), wherein the magnetic sensor (30) located furthest from the detected element (2) has a higher sensitivity than the magnetic sensor (30) located closest to the detected element (2), and wherein the magnetic sensor (30) located on a side closer to the detected element (2) comprises a GMR sensor or an AMR sensor, and the magnetic sensor (30) located on the side opposite the detected element (2) comprises a TMR sensor. [5] Cable with sensor according to claim 3 or 4, wherein the rotation detection device (1) is used to detect a rotational speed of the rotating element (11) which rotates with the wheel of a vehicle, and the cable comprises several pairs of electrical wires (41) corresponding to the several magnetic sensors (30), power wires (7) for supplying a drive current to a motor for an electric parking brake mounted on the wheel, and a sheath (42) which covers the several pairs of electrical wires (41) and the power wires (7) together.

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