JP2003270258A - Bearing unit with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing unit with sensor capable of obtaining original point signals without newly placing a sensor for original point detection and a ring for original point detection. <P>SOLUTION: A pulser ring 3 consists of an annular support member 7 and a strip magnetized body 8 pasted along its circumference direction. Magnetic poles at both ends of the magnetized body 8 are made the same pole. A gap G is formed at the butting part of the magnetized body 8, so that a part to be detected 8b for reference position signals of which the small bottom value exists in the peak of the output signal is formed at one location on the circumference of the pulser ring 3. To the signal processing means of the sensor device, a reference position signal detector for detecting the part to be detected 8b for the reference position signal of the pulser ring 3 is provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile ABS.
The present invention relates to a pulser ring that constitutes a rotation speed sensor used in, for example, and a bearing unit with a sensor having this pulser ring.

[0002]

2. Description of the Related Art In a railroad vehicle or an automobile, a rolling bearing and a sensor device and a detected portion provided on the rolling bearing are provided for supporting an axle or a rotary shaft for transmitting rotation to the axle and detecting the rotational speed of the axle. A rolling bearing unit with a sensor with a certain pulser ring is used.

[0003]

In the conventional bearing unit with a sensor, the pulser ring has magnetic poles formed at equal pitches so that a uniform output can be obtained continuously. Could not be asked. Therefore, in order to detect the absolute angle with respect to the origin, a sensor for origin detection and a ring for detection of the origin (or the point to be detected) are required, which complicates the mechanical structure and makes them more difficult to incorporate. There was a problem that a new space was needed.

An object of the present invention is to provide a sensor-equipped bearing unit that can obtain an origin signal without newly installing an origin detection sensor and an origin detection ring.

[0005]

A bearing unit with a sensor according to the present invention has a pulsar ring in which N poles and S poles are alternately arranged to output a rotation signal, and a pulsar ring arranged opposite to the pulsar ring. In a bearing unit with a sensor in which a magnetic sensor and a sensor device having a signal processing unit that performs signal processing based on an output from the magnetic sensor are rotated relative to each other, the pulser ring includes an annular support member and a periphery thereof. The output signal is formed by at least one band-shaped magnetized body attached along the direction, the end magnetic poles of the magnetized body facing each other have the same pole, and a gap is formed in the butted portion of the magnetized body. The detected part for the reference position signal, which has a small bottom value at the peak of, is formed at least at one position on the circumference of the pulser ring. In which, in the signal processing means of the sensor device, it is characterized in that the reference position signal detection unit for detecting the detected portion for the reference position signal of the pulsar ring is provided.

When the detected portion for the reference position signal is formed at one place on the circumference, the reference position signal corresponds to the conventional origin signal output once per rotation. The reference position signal detected portions may be formed at a plurality of locations on the circumference. In this case, the plurality of reference position signals are used as the origin signal and other reference positions.

According to the bearing unit with a sensor of the present invention, the pulser ring can also serve as the origin detection ring, and the magnetic sensor of the sensor device can also serve as the origin detection sensor. There is no need to install a ring for origin detection separately, and there is no need to install a sensor for origin detection separately from the magnetic sensor that detects the rotation signal, simplifying the structure of the bearing unit with sensor that obtains the rotation signal and the origin signal. can do.

Regarding the width of the end magnetic poles of the magnetized body which face each other and the gap formed in the butted portion of the magnetized body,
It is appropriately set so that the peak value of the output signal from the detected part for detecting the reference position signal is substantially equal to the output signal from the other part and the small bottom value of the peak part of the output signal is not too small. .

The areas of the end poles of the magnetized body facing each other are preferably substantially the same, and the end portions of the magnetized body are
It may be a surface perpendicular to the length direction, or may have an end surface other than the surface perpendicular to the length direction.

The signal processing means of the above-mentioned bearing unit with a sensor has, for example, a first threshold value smaller than the small bottom value of the output signal from the reference position signal detecting target portion and the reference position signal detecting target portion. A second threshold value larger than the small bottom value of the output signal and smaller than the output peak of the reference position signal detection target portion, and outputs a rotation signal when the input signal exceeds the first threshold value. The reference position signal is output when the input signal becomes smaller than the second threshold value and again exceeds the second threshold value before reaching the first threshold value.

More specifically, the signal processing means for obtaining both the rotation signal and the reference position signal uses, for example, a first threshold value smaller than the small bottom value of the output signal from the reference position signal detecting portion. A first comparator that outputs an ON signal as an A signal when the input signal is greater than or equal to the threshold value; and a reference position signal detection target value greater than a small bottom value of the output signal from the reference position signal detection target unit. A second threshold having a second threshold smaller than the output peak of the detector and outputting an ON signal as a B signal when the input signal is equal to or larger than this threshold.
Exclusive of the comparator, a flip-flop that outputs an ON signal when the input signal exceeds the first threshold value and an OFF signal when the input signal falls below the second threshold value as the C signal, and the B signal and the C signal A first exclusive OR circuit for outputting the exclusive OR signal as the D signal and a second exclusive OR circuit for outputting the exclusive OR signal of the C signal and the D signal as the E signal, The A signal is used as the rotation signal and the E signal is used as the origin output signal.

In this specification, the small bottom value, the output peak and the threshold value of the output signal refer to the case where the output voltage is positive, and the absolute value thereof when the output voltage is negative. To do.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an upper half of an embodiment of a bearing unit with a sensor according to the present invention. In the following description, the left and right means the left and right in the figure.

As shown in FIG. 1, the rolling bearing unit with a sensor comprises a rolling bearing (1), a sensor device (2) provided on the rolling bearing (1), and a pulsar ring (3) as a detected portion.

The rolling bearing (1) is an outer ring (4) which is a fixed ring,
It is provided with an inner ring (5) which is a rotating wheel, and balls (6) which are a plurality of rolling elements arranged between them. Although illustration is omitted,
The outer ring (4) is fixed to a housing or the like, and the inner ring (5) is fixed to a rotating shaft or the like.

The pulsar ring (3) comprises a support member (7) fixed to the inner ring (5) and a magnetized body (8) fixed to the support member (7).
And consists of. The support member (7) is a small-diameter cylindrical portion (7a) fitted on the outer circumference of the inner ring (5), and a perforated disk portion (flange portion) extending radially outward from the right end of the small-diameter cylindrical portion (7a). (7b),
It is composed of a large-diameter cylindrical portion (7c) extending from the outer peripheral edge portion of the perforated disc portion (7b) to the right, and has an annular shape as a whole.

An annular seal groove (9) is formed in the shoulder of the inner diameter of the right end of the outer ring (4). The outer peripheral edge portion of the contact seal (10) is fitted to the seal groove (9), and the inner peripheral edge portion of the seal (10) is a small diameter cylindrical portion (7) of the support member (7) of the pulsar ring (3).
It touches the left edge of a).

The sensor device (2) comprises a case (11) fixed to the outer ring (4) and a sensor (12) provided in the case (11).
And a signal processing means (13) for performing signal processing based on the output from the sensor (12).

The case (11) is composed of a short cylindrical outer peripheral wall (11a) and an inner peripheral wall (11b), and a perforated disc-shaped side wall (11c) connecting the right end portions of these to each other. The hollow portion has a substantially U-shaped cross section. The free end (left end) of the outer peripheral wall (11a) extends to the left of the inner peripheral wall (11b), and the free end of this outer peripheral wall (11a) is tightly fitted onto the shoulder of the right end of the outer ring (4). The free end of the inner peripheral wall (11b) is close to the right end surface of the inner ring (5) near the inner diameter.

As shown in FIG. 2, the pulsar ring (3) has a magnetized body (8) formed in a strip shape so that the front side magnetic poles have N poles and S poles alternately and at equal pitches. , The magnetized body (8) has its ends opposed to each other and is a support member.
The outer peripheral surface of (7) is fixedly formed over the entire outer peripheral surface. Here, both ends of the magnetized body (8) are N poles having a width approximately half that of the other N poles, and at the abutting portion of the magnetized body (8), these N poles of substantially half width are separated from each other. Opposite each other at (G).

Further, for example, the end portions of two strip-shaped magnetized bodies having a substantially half circumference length may be opposed to each other and fixed over the entire outer circumference of the support member (7), and the reference position may be detected every half circumference. .

This gap (G) forms a reference position signal detected portion (8b) having a weaker magnetic force than the other portions (8a) at least at one location on the circumference of the pulsar ring (3). As a result, as shown in FIG. 3, the output from the pulsar ring (3) is the same as the standard signal peak portion (Sa) that forms the sine curve with the output signal from the portion (8a) other than the butt portion. , The peak part has an inverted W shape and the small bottom value (Sb1) exists between the two peak values (Sb2) and (Sb3).
(Sb) are formed.

FIG. 3 shows the signal processing means of the sensor device for obtaining the rotation signal and the reference position signal, and FIG. 4 shows the signal obtained by this signal processing means.

In FIG. 3, the signal processing means (13) of the sensor device includes a small bottom value (Sb1) of the reference position signal peak portion (Sb) of the output signal from the reference position signal detecting target portion (8b).
A first comparator (31) which has a smaller first threshold value and outputs an ON signal as an A signal (SIG-A) when the input signal is equal to or more than this threshold value, and a reference position signal detection detected part
Smaller bottom value (Sb1) of the peak position (Sb) for the reference position signal of the output signal from (8b) and the peak part for the reference position signal
If the input signal has a second threshold value smaller than the output peaks (Sb2) and (Sb3) of (Sb) and the input signal is equal to or more than this threshold value, the ON signal is
A second comparator (32) that outputs as a signal (SIG-B),
A signal that is turned on when the input signal exceeds the first threshold,
When it falls below the second threshold, the signal of OFF is changed to the C signal (SIG
-C) output flip-flop (33) and B signal (SI
GB) and C signal (SIG-C) are exclusive OR signals and D signal (SI
The first exclusive OR circuit (34) which outputs as GD) and the exclusive OR signal of the C signal (SIG-C) and the D signal (SIG-D) is output as the E signal (SIG-E). And a second exclusive OR circuit (35).

As shown in FIG. 4, the first comparator (31)
The A signal (SIG-A) output from is the reference position signal peak part (Sb) of the output signal from the reference position signal detected part (8b).
Also in, the signal becomes an ON signal like the signal from the portion (8a) other than the butted portion. Thus, the A signal (SIG-A) can be used as the rotation signal. Second comparator (32)
The B signal (SIG-B) output from the unit is one peak (Sa) for the output signal from the part (8a) other than the butted part.
However, the output signal from the reference position signal detected portion (8b) is an ON-OFF-ON signal. The C signal (SIG-C) output from the flip-flop (33) becomes an ON signal when the A signal (SIG-A) is ON, and then when the B signal (SIG-B) is OFF. Then, it becomes an off signal. Thus flip-flop
The C signal (SIG-C) output from (33) turns on when the first threshold rises, and turns off when the second threshold falls. The D signal (SIG-D) output from the first exclusive OR circuit (34) is turned on between the first threshold value and the second threshold value, and the peak value (Sb) has a small bottom value. (Sb
When there is 1), it is turned on from the time when it reaches the second threshold after passing the small bottom value (Sb1) to the time when it falls below the second threshold. The E signal (SIG-E) output from the second exclusive OR circuit (35) is the detected portion (8b) for reference position signal.
Is only on for the output signal from
The signal (SIG-E) can be used as the reference position signal such as the origin output signal.

Therefore, when the pulsar ring (3) rotates relative to the sensor device (2), the pulsar ring (3)
The magnetic flux density generated by the magnetic force of the magnetized body (8) changes, and this change is detected by the sensor device (2). Among the signals output at this time, the A signal (SIG-A) is It is used for detecting the rotational speed, and the E signal (SIG-E) is used for detecting a reference position signal such as an origin signal. As a result, it is possible to obtain a bearing unit with a sensor which can detect the reference position signal even though the number of parts constituting the bearing unit with a sensor is the same as that for obtaining only the rotation speed.

The reference position signal is not the second exclusive OR circuit (35) but the negation of the C signal (SIG-C) and the D signal (SIG-C).
It can also be obtained by a logical product with D), and each circuit (31) (32) (33) (34) (35) of the signal processing means (13) has a function equivalent to this. Of course, it can be replaced by a plurality of circuits.

In the above description, the end portion is the N pole and the voltage from the N pole is positive, but the end portion is the S pole and the voltage from the S pole is negative. Of course, of course, in this case, the terms small bottom value, output peak and threshold value are replaced by the terms small peak value absolute value, output bottom absolute value and threshold absolute value, respectively.

Furthermore, in FIG. 1, the pulsar ring (3) is fixed to the inner ring (5).
(3) can also be used by fixing it to the outer ring (4). In this case, similarly to the above, the small-diameter cylindrical portion of the support member may be fitted to the outer ring so that the magnetized body is fixed to the inner peripheral surface of the large-diameter cylindrical portion. It is possible to fit the magnetized body to the inner peripheral surface of the small diameter cylindrical portion by fitting the portion to the outer ring.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a bearing unit with a sensor according to the present invention.

FIG. 2 is a perspective view showing an example of a pulser ring used in the bearing unit with a sensor according to the present invention.

FIG. 3 is a circuit diagram showing an embodiment of signal processing means of the bearing unit with a sensor according to the present invention.

FIG. 4 is a diagram showing each signal obtained during and at the final stage of the signal processing means of the bearing unit with a sensor according to the present invention.

[Explanation of symbols]

(1) Rolling bearing (2) Sensor device (3) Pulsar ring (8) Magnetized body (8a) Detected part for reference position signal detection (12) Magnetic sensor (G) Gap

Claims (2)

[Claims] 1. A pulser ring in which N poles and S poles are alternately arranged to output a rotation signal, a magnetic sensor arranged to face the pulser ring, and signal processing based on an output from the magnetic sensor is performed. In the sensor-equipped bearing unit in which the sensor device having the signal processing means is rotated relative to each other, the pulser ring includes an annular support member and at least one band-shaped magnetized body attached along the circumferential direction of the support member, Since the end magnetic poles of the magnetized body facing each other have the same pole and a gap is formed in the butted portion of the magnetized body, a small bottom value exists in the peak portion of the output signal. Is formed in at least one place on the circumference of the pulsar ring, and the signal processing means of the sensor device is provided with a reference position signal test object for the pulsar ring. A bearing unit with a sensor, which is provided with a reference position signal detecting portion for detecting the protruding portion. 2. The signal processing means comprises a first threshold value smaller than the small bottom value of the output signal from the reference position signal detecting target portion and a small bottom value of the output signal from the reference position signal detecting target portion. A second threshold value that is larger and smaller than the output peak of the reference position signal detection target portion, outputs a rotation signal when the input signal exceeds the first threshold value, and outputs the rotation signal when the second input signal exceeds the second threshold value. The sensor-equipped bearing unit according to claim 1, wherein the reference position signal is output when the second threshold value is exceeded again after reaching a first threshold value after being less than the first threshold value.