JP2011027448A - Rotation detector and bearing provided with rotation detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation detector selecting the detection resolution in accordance with the rotation speed of a rotator to be detected, and processing a rotation detection signal even by an ordinary processing control device of input-signal resolution, and also to provide a bearing provided with a rotation detector with this rotation detector mounted thereon. <P>SOLUTION: A rotation detector 1 has: an encoder 2 having a plurality of poles 2c to be detected arranged in a circumference direction at equal intervals; and a sensor 3 for detecting the poles 2c to be detected, and detects rotation of a detection target rotator having the encoder 2 attached thereto. The rotation detector 1 is provided with: a multiplying means 4 for multiplying the phase of the poles 2c to be detected from output from the sensor 3; a pulse generation means 5 to which the multiplied output is input and which generates pulses of at least two different magnifications; a speed detection means 10 for detecting the rotation speed of the rotator; and a pulse selection output means 11 for selecting a pulse of one magnification from the pulses generated by the pulse generation means 5 in accordance with the detected rotation speed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotation detection device used for rotation detection and rotation angle detection of wheels and various devices, and a bearing with a rotation detection device equipped with the rotation detection device.

In order to accurately detect the rotation state of a rotating body such as an automobile or a railway vehicle, there is a demand for obtaining a high-resolution, high-accuracy rotation signal. In a wheel bearing that supports a wheel rotatably with respect to a vehicle body, there is an ABS sensor used for antilock brake system control, that is, ABS control. This ABS sensor is not so high in resolution at present. When such a sensor can detect rotation with high resolution, it can be used for more advanced vehicle control such as future automatic driving, driving assistance, and safety control.
Conventionally, as a rotation detection device, a circuit method has been proposed in which a multiplied signal is obtained with high resolution from a rotation signal input of SIN and COS detected by a magnetic sensor (Patent Document 1). A schematic configuration of the rotation detection device is shown in a block diagram in FIG.

Special Table 2002-541485

  When the rotation detection device disclosed in Patent Document 1 is mounted on a wheel bearing, the behavior of the vehicle can be detected in detail by the multiplication signal, so that more advanced vehicle control can be performed. However, since the output signal resolution of the rotation detection device is different from the input signal resolution of the ABS control device used as a standard, the rotation detection device can be used as it is connected to a standard ABS control device. Can not. In order to be connectable, a new ABS control device with improved input signal resolution is required. That is, in the ABS control device, the input data increases to the number of data multiplied by the conventional number of data. For example, in the conventional rotation detection device, the rotation of the wheel is detected by a rotation detection signal of 48 pulses per rotation, whereas when the multiplication number in the rotation detection device is 40, one rotation of the wheel is 1920. It is detected by a pulse rotation detection signal. For this reason, there is a problem that the input data to the ABS control device per unit time becomes enormous, especially in the high-speed rotation range, and the processing cannot be performed by the standard ABS control device or the processing becomes slow.

  An object of the present invention is to provide a rotation detection device capable of selecting a detection resolution in accordance with the rotation speed of a rotating body to be detected, and capable of processing a rotation detection signal even with a processing control device having a standard input signal resolution, and the rotation detection device It is providing the bearing with a rotation detection apparatus which mounts.

A rotation detection device according to the present invention includes an encoder provided rotatably and provided with a plurality of detected poles arranged in a circumferential direction, and a sensor for detecting the detected pole of the encoder, wherein the encoder In the rotation detection device for detecting the rotation of the attached rotating body, a multiplying means for multiplying the phase of the detected pole from the output of the sensor, and an output of the multiplying means is inputted to at least two kinds of different magnifications. A pulse generating means for generating a pulse, a speed detecting means for detecting the rotational speed of the rotating body, and one of the magnifications of the pulses generated by the pulse generating means according to the rotational speed detected by the speed detecting means. Pulse selection output means for selecting and outputting a pulse is provided.
According to this configuration, a multiplying pulse having a high magnification obtained by multiplying the phase in the detection pole of the encoder is generated from the multiplying means, and based on the multiplied pulse, two or more types of rotation pulses having different magnifications are generated in the pulse generating means. Is done. Further, the pulse selection output means selects and outputs one kind of magnification pulse among the pulses generated by the pulse generation means in accordance with the rotational speed of the detection target rotating body detected by the speed detection means. Therefore, the detection resolution can be selected in accordance with the rotation speed of the rotating body, and the rotation detection signal can be processed even by a processing control device having a standard input signal resolution, so that highly accurate rotation detection can be performed.

  In the present invention, the pulse selection output means selects and outputs a pulse with a high magnification when the rotation speed detected by the speed detection means is low, and selects a pulse with a low magnification when the rotation speed is high. May be output. In the case of this configuration, the number of output pulses per unit time can be reduced without being influenced by the rotation speed, so that a processing control device such as an ABS control device that inputs and processes this output pulse is a conventional standard. Even if the input signal resolution is high, it can be adequately supported.

  In the present invention, the pulse generation means can continuously change the magnification of the generated pulse, and the pulse selection output means continuously applies the pulse having the magnification according to the rotational speed detected by the speed detection means. It is also possible to variably select and output. In the case of this configuration, the output pulse magnification can be finely selected in accordance with the change in rotational speed.

In this invention, the speed detecting means may detect a rotational speed from the output of the sensor.
In the present invention, the speed detecting means may detect a rotational speed from an output of a sensor different from the sensor.

  In the present invention, the pulse magnification of the lowest magnification among the pulses generated by the pulse generation means may be set to 1.

  In the present invention, a magnification changing means for changing the magnification setting of the pulse generated by the pulse generating means from the outside may be provided.

  In the present invention, one encoder may be used, and a detection output of a sensor for detecting a detected pole of the encoder may be input to the multiplication means. In the case of this configuration, it is not necessary to provide two types of sensors to simultaneously generate a high resolution (high magnification) rotation pulse and a low resolution (low magnification) rotation pulse, thereby suppressing an increase in space and weight. Can do.

  In the present invention, the encoder may be a magnetic encoder.

  In this invention, the sensor is composed of a line sensor in which sensor elements are arranged along the arrangement direction of the detected poles of the encoder, and generates a two-phase sinusoidal signal by calculation to obtain a phase within one detected pole. May be detected. In this configuration, the distortion of the detected pole pattern and the influence of noise are reduced, so that the phase of the encoder can be detected with high accuracy.

In the present invention, at least one type of magnification pulse generated by the pulse generation means may be a phase difference signal of A phase and B phase having different phases. Moreover, it is good also as a phase difference signal of A phase and B phase from which a phase difference differs 90 degree | times.
As described above, the rotation direction can be detected by outputting the phase difference signals of the A phase and the B phase whose phases are different from each other by 90 degrees as the rotation pulse signals having the same magnification. When this rotation detection device is installed in a vehicle wheel bearing, it is possible to detect forward and backward movement of the vehicle.

  In the present invention, the sensor, the multiplication unit, the pulse generation unit, and the pulse selection output unit may be integrated and integrated on a common IC chip. As a result, the rotation detection device can be mounted compactly on a wheel bearing or the like, and the weight can be reduced.

  In the present invention, the IC may be covered with a molding material. Further, the molding material may be a resin. Thereby, the waterproof and impact resistance of the rotation detection device can be ensured.

  In the present invention, a voltage / current conversion circuit for converting a pulse output from the pulse output means into a current output may be provided. A voltage / current conversion circuit for converting a pulse having the lowest magnification among the pulses output from the pulse output means into a current output may be provided. In this case, the voltage / current conversion circuit may alternately output a pulse signal having a current value of 7 mA and a pulse signal having a current value of 14 mA as the current output. Thereby, it can respond to the input signal form of the process control apparatus which processes the output signal of a rotation detection apparatus.

The bearing with a rotation detection device according to the present invention is obtained by incorporating the rotation detection device according to any one of the above configurations of the present invention into a bearing.
According to this configuration, the detection resolution can be selected according to the rotational speed of the rotating body to be detected, and the rotation detection signal can be processed even by a processing control device having a standard input signal resolution. Further, when the bearing with the rotation detection device is a wheel bearing, the detection resolution can be selected according to the vehicle speed, and the rotation detection signal can be processed even by an ABS control device having a standard input signal resolution.

  In the present invention, the bearing may be a wheel bearing for supporting a driven wheel, and the sensor may be covered with a cap. In the case of this configuration, intrusion of muddy water from the outside can be prevented, and the reliability of the rotation detection device can be improved.

  In the present invention, the bearing is a wheel bearing for driving wheel support, and a bearing end portion of a bearing space formed between an outer member and an inner member which are relatively rotatable via a rolling element is sealed. The sensor may be provided at a position inside the bearing with respect to the seal. Also in this configuration, entry of muddy water from the outside can be prevented, and the reliability of the rotation detecting device can be improved.

A rotation detection device according to the present invention includes an encoder provided rotatably and provided with a plurality of detected poles arranged in a circumferential direction, and a sensor for detecting the detected pole of the encoder, wherein the encoder In the rotation detection device for detecting the rotation of the attached rotating body, a multiplying means for multiplying the phase of the detected pole from the output of the sensor, and an output of the multiplying means is inputted to at least two kinds of different magnifications. A pulse generating means for generating a pulse, a speed detecting means for detecting the rotational speed of the rotating body, and one of the magnifications of the pulses generated by the pulse generating means according to the rotational speed detected by the speed detecting means. Since it has pulse selection output means for selecting and outputting pulses, the detection resolution can be selected according to the rotational speed of the rotating body to be detected, and the standard input signal resolution can be selected. It can process the rotation detection signal in management controller.
In the bearing with a rotation detection device of the present invention, since the rotation detection device of the present invention is incorporated in the bearing, the detection resolution can be selected according to the rotation speed of the bearing rotating wheel. The rotation detection signal can be processed. Further, when the bearing with the rotation detection device is a wheel bearing, the detection resolution can be selected according to the vehicle speed, and the rotation detection signal can be processed even by an ABS control device having a standard input signal resolution.

It is a block diagram which shows schematic structure of the rotation detection apparatus which concerns on one Embodiment of this invention. (A) is a half sectional view showing a configuration example of an encoder in the rotation detection device, and (B) is a perspective view of the encoder. (A) is a half sectional view showing another configuration example of the encoder in the rotation detection device, and (B) is a perspective view of the encoder. It is explanatory drawing of the example of 1 structure of the sensor in the rotation detection apparatus. It is a block diagram of the example of 1 structure of the multiplication means in the rotation detection apparatus. It is a block diagram which shows schematic structure of the rotation detection apparatus which concerns on other embodiment of this invention. It is a block diagram which shows schematic structure of the rotation detection apparatus which concerns on further another embodiment of this invention. It is a block diagram which shows schematic structure of the rotation detection apparatus which concerns on further another embodiment of this invention. It is sectional drawing of the example of 1 structure of the wheel bearing with a rotation detection apparatus equipped with the rotation detection apparatus in any one of the said each embodiment. It is the side view which looked at the wheel bearing with the same rotation detection device from the inboard side. It is sectional drawing of the other structural example of the wheel bearing with a rotation detection apparatus. It is the side view which looked at the wheel bearing with the same rotation detection device from the inboard side. It is sectional drawing of the further another structural example of the wheel bearing with a rotation detection apparatus. It is the side view which looked at the wheel bearing with the same rotation detection device from the inboard side. It is a block diagram which shows schematic structure of a prior art example.

  An embodiment of the present invention will be described with reference to FIGS. The rotation detection device 1 according to this embodiment includes a ring-shaped encoder 2 in which a plurality of detected poles arranged in the circumferential direction are equally arranged, a sensor 3 that detects the detected poles of the encoder 2, and the sensor 3 A multiplier 4 for generating a multiplied pulse b by multiplying the phase in the detected pole by a multiplication number N from the output of the output, and at least two different magnifications based on the multiplied pulse b generated from the multiplier 4 Pulse generation means 5 for generating a rotation pulse, speed detection means 10 for detecting the rotation speed of the rotating body to which the encoder 2 is attached, and the pulse generation means 5 according to the rotation speed detected by the speed detection means 10 And a pulse selection output means 11 for selecting and outputting a rotation pulse of one kind of magnification among the rotation pulses generated by the.

  The encoder 2 has, for example, a plurality of magnetic pole pairs (a pair of magnetic poles N and S) in the circumferential direction of the peripheral surface as a detected pole, as shown in a half sectional view and a perspective view in FIGS. It consists of one ring-shaped magnetic encoder in which 2c are magnetized by being arranged at equal positions, and can be rotated by being concentrically attached to a rotating body to be detected (not shown). In this case, the sensor 3 is a magnetic sensor that detects the magnetic poles N and S of the magnetic encoder 2 and is disposed, for example, on the outer diameter side so as to face the peripheral surface of the magnetic encoder 2.

  The configuration example of the magnetic encoder 2 in FIG. 2 is a radial type in which a magnetic pole pair 2c is magnetized on the peripheral surface. The magnetic encoder 2 is shown in FIGS. 3 (A) and 3 (B) in a half sectional view and a perspective view. It may be of the axial type shown. In the configuration example of FIG. 3, for example, a plurality of magnetic pole pairs 2c are provided in the circumferential direction of the side surface of the upright plate portion 12b extending from one end of the cylindrical portion 12a of the ring-shaped cored bar 12 having an L-shaped cross section to the outer diameter side. The magnets are aligned and arranged at equal positions, and are attached to the rotating body by fitting the cylindrical portion 12a of the cored bar 12 to the outer peripheral surface of the rotating body such as a rotating shaft. In this case, the magnetic sensor 3 is arranged in the axial direction so as to face the magnetized surface of the magnetic encoder 2.

  Here, the magnetic sensor 3 includes line sensors 3A and 3B and an operational amplifier 30 as shown in FIG. The line sensors 3 </ b> A and 3 </ b> B are configured by arranging a plurality of magnetic sensor elements 3 a so as to be aligned along the arrangement direction of the magnetic poles of the magnetic encoder 2. The operational amplifier 30 includes a plurality of adder circuits 31, 32, 33, 34 and an inverter 35. FIG. 4A is a waveform diagram in which a magnetic pole section of the magnetic encoder 2 is converted into a magnetic field strength. In this case, the first line sensor 3A is arranged in association with the 90-degree phase section of the 180-degree phase section in FIG. 4A, and the second line sensor 3B is the remaining 90-degree phase section. It is arranged in association with. With such an arrangement, the signal S1 obtained by adding the detection signal of the first line sensor 3A by the addition circuit 31 and the signal S2 obtained by adding the detection signal of the second line sensor 3B by the addition circuit 32 are added separately. By adding in the circuit 33, a sin signal corresponding to the magnetic field signal as shown in FIG. 4C is obtained. Further, the signal S1 and the signal S2 via the inverter 35 are added by another adding circuit 34 to obtain a cos signal corresponding to the magnetic field signal as shown in FIG. The phase in the magnetic pole can be detected from the two-phase output signal thus obtained.

  When the magnetic sensor 3 is constituted by the line sensor in this way, the influence of the distortion of the magnetic field pattern and noise are reduced, so that the phase of the magnetic encoder 2 can be detected with high accuracy.

As another example of the magnetic sensor 3, when the pitch λ of one magnetic pole pair of the magnetic encoder 2 is one cycle, the magnetic sensors 3 are arranged apart from each other in the arrangement direction of the magnetic poles so that the phase difference is 90 degrees (λ / 4). The magnetic pole phase (φ = tan ^-1 (sinφ / cos φ)) is multiplied from the two-phase signals (sinφ, cosφ) obtained by these two magnetic sensor elements. It is good also as what calculates.

As shown in FIG. 5, the multiplication unit 4 in this case includes a signal generation unit 41, a sector detection unit 42, a multiplexer unit 43, and a fine interpolation unit 44.
The signal generation means 41 has the same amplitude A0 and the same average value C0 from the two-phase signal sin, cos which is the output of the magnetic sensor 3, m is a positive integer less than n, and i is 1. As a positive integer of ˜2 ^m−1 , it is means for generating 2 ^m−1 signals si that are successively shifted in phase by 2π / 2 ^m−1 .
The sector generating means 42 generates m digital signals bn-m + 1, bn-m + 2,..., Bn-1, bn coded to define 2 ^m equal sectors Pi. This means is for detecting 2 ^m sectors Pi divided by 2 ^m-1 signals si.
The multiplexer means 43 is controlled by the m digital signals bn-m + 1, bn-m + 2,..., Bn-1 and bn generated from the sector generating means 42, and is generated from the signal generating means 41. 2 ^m−1 of the above-mentioned signals si are processed, and the amplitude is constituted by a portion of the series of 2 ^m−1 of the signals si between the average value C0 and the first threshold value L1. One signal A, the amplitude of which is between the first threshold value L1 of the series of 2 ^m-1 signals si and the second threshold value L2 higher than this threshold value. This is an analog means for generating the other signal B constituted by the portion.
Fine interpolation unit 44, in order to obtain the desired resolution, the angle 2 [pi / 2 2 ^m pieces of each angle 2π / 2 2 ^nm number code to subdivide the same sub-sector of the ⁿ of the sector Pi of ^m The (n−m) digital signals b1, b2,..., Bn-m−1, bn-m (here, b1, b2,..., B8, b9) are multiplied to rotation pulses.

  The pulse generation means 5 is means for generating at least two types of rotation pulses having different magnifications from the multiplication pulse b which is phase data in the detected pole (magnetic pole pair) 2c inputted from the multiplication means 4. is there. Here, rotation pulses having three different magnifications are generated simultaneously from the high-resolution rotation pulse generators 6A, 6B, and 6C. Assuming that the multiplication number N in the multiplication means 4 is 20, the first high-resolution rotation pulse generation unit 6A outputs a rotation pulse having a multiplication factor (× 20) as it is, for example. That is, the position (phase) within the magnetic pole pair 2c of the magnetic encoder 2 is detected by 20 rotation pulses. The second high-resolution rotation pulse generator 6B divides the multiplied pulse b to generate a rotation pulse having a predetermined magnification (× 10) lower than the multiplication number N, for example. Further, from the third high-resolution rotation pulse generator 6C, the multiplied pulse b is further divided, for example, a rotation pulse of 1 × magnification (× 1) (one rotation pulse for one magnetic pole pair). Is generated. That is, the third high-resolution rotation pulse output unit 6C serves as a normal rotation pulse generation unit.

  Here, the magnification of the rotation pulse generated in the pulse generating means 5 is fixed to 20 times, 10 times, and 1 time. However, as indicated by a virtual line in FIG. It is also possible to change the magnification of the rotation pulse output by a command from the magnification changing means 7.

  The speed detection means 10 detects the rotation speed of the rotating body to be detected from the output of the magnetic sensor 3. The magnetic sensor 3, the multiplication means 4, the pulse generation means 5, the speed detection means 10, and the pulse selection output means 11 are integrated and integrated on a common IC chip 8, and one type is selected by the pulse selection output means 11. There is provided one output terminal for outputting a rotation pulse with a magnification of. Thereby, the rotation detector 1 can be mounted compactly on a wheel bearing or the like, and the weight can be reduced.

  Of a plurality of types of rotation pulses having different magnifications generated by the pulse generation unit 5 and selected and output by the pulse selection output unit 11, the rotation pulse having the lowest magnification, that is, in this embodiment, a magnification of 1 × The rotation pulse of (× 1) is converted into a current output by the voltage / current conversion circuit 9 provided in the next stage. Specifically, a pulse signal having a current value of 7 mA and a pulse signal having a current value of 14 mA are alternately output as current outputs. Thereby, it can respond to the input signal form of the process control apparatus which processes the output signal of the rotation detection apparatus 1.

  The voltage / current conversion circuit 9 is mounted on a printed board (not shown) together with the IC chip 8 and is entirely covered with a molding material. The mold material is, for example, a resin. Thereby, the waterproof and impact resistance of the rotation detector 1 can be ensured.

  According to the rotation detecting device 1 having this configuration, the multiplying pulse b having a high magnification obtained by multiplying the phase in the detected pole 2c of the encoder 2 is generated from the multiplying means 4, and the pulse generating means 5 based on the multiplied pulse b Two or more types of rotation pulses having different magnifications are generated, and rotation of one type of the rotation pulses generated by the pulse generation unit 5 according to the rotation speed of the rotating body to be detected detected by the speed detection unit 10. Since the pulse is selected and output by the pulse selection output means 11, the detection resolution can be selected according to the rotation speed of the rotating body, and the rotation detection signal can be processed even by a processing control device having a standard input signal resolution. High-precision rotation detection can be performed.

  That is, for example, when a wheel bearing is equipped with a high-resolution rotation detection device and used for wheel rotation detection, if the signal processing capability of the vehicle ABS control device, which is a processing control device, is standard, it is high when traveling at high speed. When a resolution rotation pulse is input, the ABS control device cannot process the input signal or the processing is delayed. In the case of this rotation detector 1, even if the resolution is high, the pulse selection output means 11 selects a low-magnification rotation pulse during high-speed driving and inputs it to the ABS control device, and selects a high-magnification rotation pulse during low-speed driving. By inputting the data to the ABS control device, signal processing can be sufficiently performed even with a standard ABS control device.

For example, when the high-resolution rotation pulse generation units 6A, 6B, and 6C of the pulse generation unit 5 are prepared to generate rotation pulses with magnifications of 40 times, 20 times, and 2 times, the above pulse selection output As an example of the pulse selection by means 11, each magnification is selected by a selection method in which a rotation pulse with a magnification of 40 times is selected in a speed range up to 40 km / h, and a rotation pulse with a magnification of 2 is selected in a speed region higher than that. The rotation pulse can be selected according to the speed.
As another example, a rotation pulse with a magnification of 40 times is selected in a speed range up to 40 km / h, a rotation pulse with a magnification of 20 times is selected in a speed range of 40 to 80 km / h, and a speed range higher than that. Then, it is possible to select the rotation pulse of each magnification according to the speed by the selection method of selecting the rotation pulse having a magnification of 2 times.

  Thus, the pulse selection output means 11 selects and outputs a rotation pulse with a high magnification when the rotation speed detected by the speed detection means 10 is low, and selects a rotation pulse with a low magnification when the rotation speed is high. Since the number of rotation pulses per unit time can be reduced without being influenced by the rotation speed, a processing control device such as an ABS control device that inputs and processes this rotation pulse is a conventional method. Even a standard input signal resolution can be adequately accommodated.

  In this embodiment, since there is one encoder 2 and the detection output of the sensor 3 for detecting the detected pole 2c of this encoder 2 is input to the multiplication means 4, rotation with high resolution (high magnification) is possible. In order to simultaneously generate a pulse and a low resolution (low magnification) rotation pulse, it is not necessary to provide two types of sensors, and an increase in space and weight can be suppressed.

  FIG. 6 shows another embodiment of the rotation detection device of the present invention. In this rotation detection device 1, the speed detection means 10 </ b> A detects the rotation speed of the rotating body to be detected from the output of an external sensor (not shown) different from the magnetic sensor 3. As a rotation pulse generation unit in the pulse generation unit 5A, a high-resolution rotation pulse generation unit 6A (for example, magnification 40) that generates a high-magnification rotation pulse from the output of the multiplication unit 4, and a high-resolution rotation that generates a low-magnification rotation pulse It has a pulse generation unit 6B. Other configurations are the same as those in the embodiment of FIG.

FIG. 7 shows still another embodiment of the rotation detection device of the present invention. In the rotation detection device 1, in the embodiment of FIG. 1, the high-resolution rotation pulse generation unit 6D in the pulse generation unit 5B is configured to be capable of continuously changing the rotation pulse magnification (for example, 40 times to 2 times). The pulse selection output means 11 continuously variably selects and outputs a rotation pulse having a magnification corresponding to the rotation speed detected by the speed detection means 10. Other configurations are the same as those in the embodiment of FIG.
In the case of this embodiment, the output pulse magnification can be finely selected in accordance with the change in rotational speed.

  FIG. 8 shows still another embodiment of the rotation detection device of the present invention. In the rotation detection device 1, in the embodiment of FIG. 1, as a high-resolution rotation pulse generation unit that generates at least one type of magnification rotation pulse in the pulse generation means 5 </ b> C, A pair of high-resolution rotation pulse generators that individually generate B-phase rotation pulses are provided. Here, a pair of high-resolution rotation pulse generators 6AA and 6AB (magnification 40) for generating high-magnification A-phase / B-phase rotation pulses and a pair of low-magnification A-phase / B-phase rotation pulses are generated. High-resolution rotation pulse generators 6BA and 6BB are provided. The pulse selection output means 11 outputs both A-phase and B-phase rotation pulses when selecting a high-magnification rotation pulse or when selecting a low-magnification rotation pulse. Therefore, the pulse selection output means 11 is provided with two output terminals for A phase and B phase. Other configurations are the same as those in the embodiment of FIG.

  As described above, the rotation direction can be detected by outputting the phase difference signals of the A phase and the B phase whose phases are different from each other by 90 degrees as the rotation pulse signals having the same magnification. When this rotation detection device 1 is mounted on a wheel bearing of a vehicle, it is possible to detect forward / backward movement of the vehicle.

  FIG. 9 shows a cross-sectional view of a wheel bearing which is an example of a bearing equipped with the rotation detection device 1 of any of the above-described embodiments. This wheel bearing is attached to a vehicle such as an automobile. In this specification, the side closer to the outer side in the vehicle width direction when attached to the vehicle is referred to as the outboard side, and the center side in the vehicle width direction. This is called the inboard side. FIG. 10 is a side view of the wheel bearing as viewed from the inboard side.

  This wheel bearing has a double-row rolling element 53 interposed between an outer member 51 and an inner member 52, and supports the wheel rotatably with respect to the vehicle body. It is equipped with. The outer shape of the encoder 2 and the sensor unit of the rotation detection device 1 is a shape corresponding to the mounting form for each example.

  The outer member 51 is a fixed member, and the inner member 52 is a rotating member. The rolling elements 53 of each row are held by the cage 54 for each row, and are formed on the outer circumference of the inner row 52 and the double row rolling surfaces 55 formed on the inner circumference of the outer member 51. Further, it is interposed between the double row rolling surfaces 56. These wheel bearings are of a double row angular contact ball bearing type, and the rolling surfaces 55, 55, 56, 56 of both rows are formed such that the contact angles are back to back.

The example of FIG. 9 is a so-called third generation type, and is an example applied to driving wheel support. The inner member 52 includes two members, a hub wheel 57 and an inner ring 58 fitted to the outer periphery of the inboard side portion of the shaft portion 57a of the hub wheel 57. The rolling surfaces 56 of each row are formed on the outer periphery of 58. The shaft portion 57a of the hub wheel 57 has a center hole 57c through which a stem portion (not shown) of a constant velocity joint is inserted. The inner ring 58 is fitted in a stepped portion formed in the shaft portion 57a of the hub wheel 57, and is fixed to the hub wheel 57 by a crimping portion 57aa provided at the inboard side end of the shaft portion 57a. The hub wheel 57 has a wheel mounting flange 57b on the outer periphery in the vicinity of the end portion on the outboard side, and a wheel and a brake rotor (both not shown) are attached to the wheel mounting flange 57b by a hub bolt 59. The hub bolt 59 is press-fitted into a bolt mounting hole provided in the wheel mounting flange 57b. The outer member 51 is an integral member as a whole, and has a vehicle body mounting flange 51b on the outer periphery. The outer member 51 is attached to a knuckle (not shown) of the suspension device by a knuckle bolt inserted through the bolt insertion hole 60 of the vehicle body attachment flange 51b.
Both ends of the bearing space between the outer member 51 and the inner member 52 are sealed by sealing devices 61 and 62 made of contact seals or the like.

  A sensor portion (portion in which the sensor 3 is embedded) 13 of the rotation detection device 1 is attached to the inboard side end of the outer member 51 via a sensor attachment member 72. The sensor mounting member 72 is a ring-shaped metal plate that fits on the outer peripheral surface of the outer member 51 and contacts the end surface, and has a sensor mounting piece 72a for mounting the rotation detection device 1 on a part of the circumferential direction. ing. The magnetic encoder 2 of the rotation detection device 1 is of the axial type shown in FIG. 3, and is provided with a multipolar magnet on the upright portion 12 b of the cored bar 12 having an L-shaped cross section. Is fitted. The magnetic encoder 2 also serves as a part of the sealing device 61 on the inboard side. The magnetic encoder 2 and the sensor 3 face each other in the axial direction. A cable 8A is drawn from the sensor portion 13.

  According to the wheel bearing with the rotation detection device of this configuration, the detection resolution of the rotation detection device 1 can be selected according to the vehicle speed, so the ABS control device of the ECU on the vehicle body that processes the output signal of the rotation detection device 1 is standard. Even if it is a thing, a rotation detection signal can be processed. That is, if the signal processing capability of the ABS control device is standard, the input signal cannot be processed by the ABS control device when a high-resolution rotation pulse is input during high-speed driving, or the processing is delayed. If a high-speed rotation pulse is selected and input during low-speed driving, a standard ABS control device can sufficiently perform signal processing.

  FIGS. 11 and 12 are for the driven wheel in the example shown in FIGS. 9 and 10, and the hub wheel 57 does not have a center hole and is solid. The end portion on the inboard side of the outer member 51 extends in the axial direction from the inner member 52, and the end face opening is covered with a cap 74. The cap 74 is fitted and attached to the inner periphery of the outer member 51 with a flange 74a provided on the outer peripheral edge. The sensor portion 13 is attached to the cap 74 so as to face the magnetic encoder 2. In the cap 74, at least the sensor portion 13 of the rotation detection device 1 is fitted, the rotation detection device main body is detachably provided using a bolt, a nut, or the like not shown. In a state where the sensor portion 13 is fitted into the cap 74, the annular gap of the cap 74 that can be formed between the rotation detecting device main body is tightly sealed by the elasticity of the molding material (elastic member) that covers the sensor portion 13. It is configured to be. The magnetic encoder 2 is fitted and attached to the outer periphery of the inner ring 58, and faces the rotation detection device 1 in the axial direction.

  In the case of this configuration, the application to the driven wheel is limited. However, since the entire end opening of the outer member 51 is covered by the cap 74, intrusion of muddy water or the like from the outside into the installation portion of the rotation detection device 1 The reliability of the rotation detection device 1 can be improved.

FIGS. 13 and 14 show an example in which the sealing device 61 for the bearing space on the inboard side is arranged outside the magnetic encoder 2 in the example shown in FIGS. 9 and 10. That is, a sealing device 61 made of a contact seal or the like is provided between the annular sensor mounting member 72 attached to the outer member 51 and the inner ring 58.
In the case of this configuration, the magnetic encoder 2 is sealed with respect to the external space by the sealing device 61, and foreign matter is prevented from being caught between the magnetic encoder 2 and the sensor portion 13. Other configurations and effects are the same as those in the examples of FIGS.

  In addition, although the wheel bearing of each said embodiment described the example of the 3rd generation type | mold, the wheel bearing with a rotation detection apparatus of this invention is the 1st generation type | mold and the 1st generation type in which a hub and a bearing are provided separately. It can also be applied to second generation type wheel bearings for the 4th generation type in which the inner member is composed of a hub ring and a constant velocity joint outer ring, and the outer member is for the rotation side and the inner member is for the fixed side wheel. It can also be applied to bearings. Further, the present invention is not limited to the angular ball bearing type, and can be applied to various wheel bearings. Furthermore, the detection target in the rotation detection device 1 is not limited to the magnetic encoder, and may be a metal gear-shaped pulsar ring, for example.

DESCRIPTION OF SYMBOLS 1 ... Rotation detection apparatus 2 ... Encoder 3 ... Sensor 4 ... Multiplication means 5, 5A, 5B ... Pulse generation means 6A, 6AA, 6AB, 6B, 6C, 6D ... High resolution rotation pulse generation part 7 ... Magnification change means 8 ... Integration Circuit 9 ... Voltage / current conversion circuit 10, 10A ... Speed detection means 11 ... Pulse selection output means

Claims (21)

The encoder includes a plurality of detected poles that are rotatably provided and are arranged in the circumferential direction, and a sensor that detects the detected poles of the encoder, and rotates the rotating body to which the encoder is attached. In the rotation detection device to detect,
A multiplier for multiplying the phase of the detected pole from the output of the sensor; a pulse generator for generating pulses of at least two different magnifications by inputting the output of the multiplier; and a rotational speed of the rotating body. And a pulse selection output means for selecting and outputting a pulse of one kind of magnification among the pulses generated by the pulse generation means according to the rotational speed detected by the speed detection means. A rotation detection device characterized by that.   2. The pulse selection output unit according to claim 1, wherein the pulse selection output unit selects and outputs a high-magnification pulse when the rotation speed detected by the speed detection unit is low, and selects a low-magnification pulse when the rotation speed is high. Rotation detection device that is supposed to be output.   2. The pulse generation unit according to claim 1, wherein the pulse generation unit can continuously change the magnification of the generated pulse, and the pulse selection output unit continuously applies the pulse having the magnification according to the rotation speed detected by the speed detection unit. Rotation detection device that is variably selected and output.   4. The rotation detection device according to claim 1, wherein the speed detection unit detects a rotation speed from an output of the sensor. 5.   4. The rotation detection device according to claim 1, wherein the speed detection unit detects a rotation speed from an output of a sensor different from the sensor. 5.   6. The rotation detection device according to claim 1, wherein a pulse magnification of the lowest magnification among the pulses generated by the pulse generation means is set to 1.   7. The rotation detection device according to claim 1, further comprising a magnification changing unit that changes the magnification setting of a pulse generated by the pulse generating unit from the outside.   6. The rotation detection device according to claim 1, wherein the encoder is one and a detection output of a sensor for detecting a detected pole of the encoder is input to the multiplication means.   9. The rotation detection device according to claim 1, wherein the encoder is a magnetic encoder.   10. The sensor according to claim 1, wherein the sensor includes a line sensor in which sensor elements are arranged along an arrangement direction of the detection poles of the encoder, and generates a two-phase sinusoidal signal by calculation. And a rotation detecting device for detecting a phase in one detected pole.   11. The rotation detection device according to claim 1, wherein at least one type of magnification pulse generated by the pulse generation unit is used as a phase difference signal of A phase and B phase having different phases.   12. The rotation detection device according to claim 11, wherein at least one type of magnification pulse generated by the pulse generation means is used as a phase difference signal of A phase and B phase whose phases are different from each other by 90 degrees.   13. The rotation detection device according to claim 1, wherein the sensor, the multiplication unit, the pulse generation unit, and the pulse selection output unit are integrated and integrated on a common IC chip. .   The rotation detection device according to claim 13, wherein the IC is covered with a molding material.   The rotation detection device according to claim 14, wherein the molding material is resin.   16. The rotation detection device according to claim 1, further comprising a voltage / current conversion circuit that converts a pulse output from the pulse output means into a current output.   17. The rotation detection device according to claim 16, further comprising a voltage / current conversion circuit for converting a pulse having the lowest magnification among the pulses output from the pulse output means into a current output.   18. The rotation detection device according to claim 16, wherein the voltage / current conversion circuit alternately outputs a pulse signal having a current value of 7 mA and a pulse signal having a current value of 14 mA as the current output. .   A bearing with a rotation detection device, wherein the rotation detection device according to any one of claims 1 to 18 is incorporated in the bearing.   The bearing with a rotation detection device according to claim 19, wherein the bearing is a wheel bearing for supporting a driven wheel, and the sensor is covered with a cap.   The bearing end of the bearing space according to claim 20, wherein the bearing is a wheel bearing for driving wheel support, and is formed between an outer member and an inner member that are relatively rotatable via a rolling element. A bearing with a rotation detecting device, which is sealed with a seal and has the sensor provided at a position inside the bearing with respect to the seal.

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