JP2009288013A - Rotation detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation detector with high detection accuracy, which is easily fixed to a detection object having a circumferential side without the need for complicated processes to the joint of an encoder pattern. <P>SOLUTION: This rotation detector is equipped with: a pattern support member 12 which has an annular pattern holding part 11 for holding the encoder pattern 11a and is supported by a drive shaft 1 whose rotation is to be detected; and a detection means 20 which detects the pattern change at a specific rotation detection position on a pattern rotation circumference when the pattern support member 12 is rotated. The pattern support member 12 is constituted by a plurality of division objects 31, 32 having circular sections, respectively, and the division objects 31, 32 are connected to each other. The detection means 20 has a plurality of detection parts 21, 22 which detect the change of the pattern 11a at the plurality of rotation detection positions P1, P2 having different spacing angle θs from the center angles of the circular sections of the division objects 31, 32 on the circumference where the pattern 11a is rotated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotation detection device, and more particularly to a rotation detection device suitable for a magnetic rotary encoder.

  Conventionally, as rotation detection devices for detecting rotation and fluctuations thereof, there have been an optical device using a laser and a magnetic device using a magnetic gear, but when used in a relatively severe environment, for example, a vehicle When detecting rotation of wheels and axles, and detecting rotation of drive shafts, propeller shafts, etc., a magnetic detection type is often used from the viewpoint of stability and reliability of the apparatus.

  As a conventional rotation detection device of this type, for example, a magnetic encoder is known in which a magnetic material using rubber as a binder is vulcanized and formed into a string shape and bonded and fixed to the outer peripheral surface of a cylindrical portion to reduce costs. In this encoder, the boundary of the magnetic pole between the N pole and the S pole is made to coincide with the joint portion of the string-like magnetic body (see, for example, Patent Document 1).

  In addition, the annular magnetic encoder is bonded to the magnetic material with a thermoplastic resin, and is divided into a plurality of segments adjacent in the circumferential direction. What constitutes a magnetic encoder is known (see, for example, Patent Document 2).

  In addition, a magnetic pattern is formed directly by magnetizing the outer peripheral surface portion of the rotating shaft having an outer peripheral surface with high cylindrical accuracy, and a magnetic sensor is arranged close to the magnetic pattern to ensure the required resolution. Is also known (see, for example, Patent Document 3).

A detection circuit board having a Hall element is supported in the sensor block, and a cylindrical rotor mounting block is integrally coupled to the sensor block so as to cover the opening of the sensor block, thereby forming a magnetic pattern on the outer periphery. When the magnet rotor rotates in the rotor mounting block, there is one that detects the change of the magnetic field by the Hall element while suppressing the influence of moisture or the like on the detection part (for example, Patent Document 4). reference).
JP 2007-333718 A JP 2007-192653 A JP 2001-165946 A JP 09-138240 A

  However, in the conventional rotation detection device as described above, the magnetic pattern is fixed to the annular holding member by adhesion or the like, so that the detected object whose rotation is to be detected has a large diameter at both ends. If a large-diameter component is mounted, the rotation detector cannot be mounted on the subject, and the object to be detected is a large component even when the magnetic pattern is formed directly on the outer peripheral surface of a cylindrical or columnar shaft. When a large part is assembled, there is a problem that it is not easy to form a magnetic pattern directly on the outer peripheral surface of a cylindrical or columnar shaft.

  In addition, a rotation detection device with a relatively low cost and a relatively high detection accuracy (resolution) can be realized by making the magnetic pattern into a magnetic tape shape. However, as in the above-described conventional example, the magnetic tape is formed into an annular holding member. When affixing to the outer peripheral surface of the magnetic tape, not only the processing of the joint of the magnetic tape is complicated, but also the detection accuracy is somewhat lowered even if such processing is performed.

  Accordingly, the present invention provides a rotation detection device with high detection accuracy that does not require complicated processing at the joint of encoder patterns and can be easily attached to a detection target having a circumferential surface. With the goal.

  In order to achieve the above object, the rotation detection device according to the present invention includes: (1) a pattern having an annular pattern holding unit that holds an encoder pattern for rotation detection, and supported by a detection target to be detected for rotation. A rotation member comprising: a support member; and a detection unit that detects a change in the encoder pattern at a specific rotation detection position on a circumference around which the encoder pattern rotates when the pattern support member rotates together with the detection target. In the detection device, the pattern support member is configured by a plurality of divided bodies each having an arcuate cross section, the plurality of divided bodies are coupled to each other, and the detection means is arranged on a circumference around which the encoder pattern rotates. Changes in the encoder pattern are detected at a plurality of rotation detection positions that are spaced apart from the central angle of the arcuate section of the divided body. And it has a detection unit number.

  With this configuration, even if the encoder pattern is interrupted at the joint portion of the plurality of divided bodies, when the interrupted portion reaches the rotation detection position of any one of the plurality of detectors, the uninterrupted encoder pattern portion is Since it is located at the rotation detection position of the other detection unit among the plurality, and any of the plurality of detection units can reliably detect a change in the encoder pattern with high accuracy, complicated processing is performed at the joint of the encoder pattern. There is no need to do it. Moreover, since the pattern support member is composed of a plurality of divided bodies, the pattern support member can be easily attached to a detected body having a circumferential surface.

  In the rotation detection device having the configuration described in (1) above, (2) the plurality of divided bodies are preferably a pair of divided bodies each having a semicircular cross section.

  With this configuration, since the number of joints of the divided bodies is reduced, the configuration can be simply suppressed, and the encoder pattern is less interrupted and arranged symmetrically, so that the required detection accuracy can be ensured. .

  In the rotation detection device having the configuration described in the above (1) and (2), (3) the encoder pattern is formed so as to periodically change at a certain rotation angle, and the plurality of rotation detections It is preferable that the position is set with a separation angle equal to or greater than the certain rotation angle.

  With this configuration, since the encoder pattern is simple and the pattern change becomes clear, reliable detection can be performed, and the joint section of the encoder pattern can be easily set according to the change cycle of the encoder pattern.

  In the rotation detection device having the configuration described in the above (1) to (3), (4) the encoder pattern is a fastening portion of the plurality of divided bodies of the pattern support member, and a predetermined allowable breakage angle. It is preferable that the rotation is interrupted within a narrow angle range, and the plurality of rotation detection positions are set with a separation angle larger than the allowable clearance.

  With this configuration, the encoder pattern is interrupted at any one of the rotation detection positions, and even if the interrupted state is continued within the allowable angle of interruption, the encoder pattern is not interrupted at the other rotation detection positions. Thus, any one of the plurality of detection units can reliably detect a change in the encoder pattern with high accuracy. Here, it is preferable that the allowable angle of break is somewhat small, but it is not necessary to be within the shortest cycle of the change of the encoder pattern, and can be set to an angle range for a plurality of cycles.

  In the rotation detection device having the configuration described in the above (3) and (4), (5) the encoder pattern is configured by a magnetic pattern in which a magnetic pole periodically changes at a certain rotation angle. It is preferable that a plurality of detection units detect changes in the magnetic poles at the plurality of different rotation detection positions.

  With this configuration, the rotation detection device can maintain good detection accuracy and reliability against moisture and dust compared to the optical detection method, and the cost of forming the magnetic encoder pattern and the cost of the detection means can be reduced. it can.

  In the rotation detection device having the configuration described in (5) above, (6) the pattern holding unit is configured by a magnetic tape.

  With this configuration, the magnetic encoder pattern can be finely formed at low cost.

  In the rotation detection device having the configuration described in the above (1) to (6), (7) the pattern support member is provided with a cylindrical support member main body and a diameter extending radially outward from the support member main body. It is preferable that it is comprised by the formed flange part and the pattern holding part located in the outer periphery of this flange part.

  With this configuration, the encoder pattern can be easily manufactured, the length of the encoder pattern in the circumferential direction can be sufficiently secured, and the required detection accuracy can be secured.

  In the rotation detection device having the configuration described in (7) above, (8) an outer cylinder member that is rotatably coupled to the support member main body of the pattern support member via a bearing is provided, and the outer cylinder member The plurality of detection units of the detection unit may be supported in the vicinity of the plurality of rotation detection positions.

  With this configuration, even if the detection target is not only rotating but also a rotating shaft that swings, for example, a drive shaft or a propeller shaft that drives a driving wheel of a vehicle, a plurality of detection portions of the detection means are encoded with an encoder pattern. Therefore, it is possible to support at a necessary detection position with respect to the rotation axis, which has conventionally been difficult to detect rotation not only from the encoder pattern but also from the point of sensor support. Rotation detection can be performed.

  Here, the interruption of the encoder pattern is not limited to the case where the magnetic tape having the pattern is cut, for example, and even if the tape itself is continuous, it may be bent radially inward of the pattern support member. It is intended to include a case in which the change in the encoder pattern is partially undetectable due to being covered. Moreover, the coupling | bonding of the division bodies of a pattern support member can ensure the precision of a required circumferential surface, for example by using together fastening members, such as a volt | bolt, and the uneven | corrugated fitting for positioning. Further, each encoder pattern fixed to the plurality of divided bodies has a plurality of pattern portions of a continuous annular encoder pattern in a reading region other than both ends fixed to the joint portion of the plurality of divided bodies by adhesion or the like. It is desirable that they are phase-aligned to form

  According to the present invention, even when the encoder pattern is interrupted at the joint portion of the plurality of divided bodies, when the interrupted portion reaches the rotation detection position of any one of the plurality of detectors, the other detector The encoder pattern is not interrupted at the rotation detection position, and the encoder pattern change can be reliably detected by one of the plurality of detection units with high accuracy, so that complicated processing is performed at the joint of the encoder pattern. The necessity can be eliminated, and the pattern support member is constituted by a plurality of divided bodies, so that the pattern supporting member can be easily attached to a detected body having a circumferential surface. As a result, it is possible to provide a rotation detection device with high detection accuracy that does not require complicated processing at the joint of encoder patterns and can be easily mounted on a detection target having a circumferential surface.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a longitudinal sectional view showing a schematic configuration of the rotation detection device according to the first embodiment of the present invention, and FIG. 2 is a schematic configuration of detection means of the rotation detection device according to the first embodiment. It is a schematic diagram which shows. FIG. 3 is an exploded perspective view showing the configuration of main components of the rotation detection device according to the first embodiment. In addition, the rotation detection apparatus of this embodiment detects the rotation fluctuation | variation of the drive shaft which drives the driving wheel of a vehicle.

  First, the configuration will be described.

  As shown in FIGS. 1 to 3, the rotation detection device 10 of the present embodiment has an annular pattern holding portion 11 that holds an encoder pattern 11 a for detecting rotation, and a drive shaft 1 that should detect rotation. A pattern support member 12 supported in a pressure contact state via a silicon rubber sheet 13 which is an elastic sheet (detected body), and a circle around which the encoder pattern 11a rotates when the pattern support member 12 rotates together with the drive shaft 1 Detecting means 20 for detecting a change in the encoder pattern at a specific rotation detection position on the circumference.

  Although not shown in detail, the drive shaft 1 is connected to the differential output portion of the transmission at one end in the axial direction via a constant velocity joint, and is connected to the drive wheel side at the other end in the axial direction. When the vehicle is running, it swings in the vertical direction or the like almost in synchronization with a suspension arm (not shown).

  The pattern holding unit 11 is made of a magnetic material, for example, a magnetic tape, which is integrally fixed to the outer peripheral surface of the pattern support member 12 by adhesion or the like. Is held. Specifically, the encoder pattern 11a has N poles and S poles alternately arranged at equal intervals in the circumferential direction, and is directly magnetized on a magnetic tape made of a magnetic material using resin or rubber as a binder. Then, the magnetic pole is formed and is held by the pattern holding unit 11.

  Although the magnetic encoder pattern itself is well known and will not be described in detail, the encoder pattern 11a is not limited to a plurality of magnetic poles arranged at equal intervals. Further, the encoder pattern 11a may be formed by forming a plurality of rows of different annular magnetic patterns so as to be adjacent to each other in the axial direction of the detection target. Of course, it is not necessarily limited to the magnetic pattern, and may be another non-contact detection element such as an optical encoder pattern or may be configured as a contact type detection element. The pattern holding unit 11 may be a thin metal layer or a sheet metal that holds a magnetic tape on which a magnetic encoder pattern is formed.

  The pattern support member 12 includes a cylindrical support member main body 12a and a cored bar portion 12c including a flange portion 12b having a circular collar shape that is radially expanded from one end of the support member main body 12a. The pattern holding portion 11 is integrally fixed to the flange portion 12b so as to be positioned on the outer periphery of the flange portion 12b of the core metal portion 12c.

  As shown in FIGS. 2 and 3, the pattern support member 12 includes a plurality of divided bodies 31 and 32 each having an arcuate cross section having the same central angle. In the present embodiment, the plurality of divided bodies 31, Reference numeral 32 denotes a pair of substantially semi-cylindrical divided bodies each having a semicircular (center angle of 180 degrees) cross section.

  The plurality of divided bodies 31, 32 are made to coincide with the central axes of the plurality of divided bodies 31, 32 by fitting a plurality of bolts 33 as fastening members with a plurality of positioning pins 34 and concave / convex fitting of the round holes 35. At the same time, they are positioned relative to each other in the axial direction, and the required circumferential accuracy and coaxial accuracy required for the inner peripheral surface of the support member main body 12a and the outer peripheral surface of the flange portion 12b are ensured. It is like that. The silicon rubber sheet 13 is divided into semi-cylindrical sheet portions 13a and 13b bonded to the inner peripheral sides of the plurality of divided bodies 31 and 32.

  As shown in FIG. 2, the detection unit 20 includes a plurality of detection units 21 and 22, and the plurality of detection units 21 and 22 are divided bodies 31 and 22 on the circumference around which the encoder pattern 11 a rotates. Changes in the encoder pattern 11a are detected at a plurality of rotation detection positions P1 and P2 that are spaced apart from the central angle of the arcuate section of 32 (180 degrees in this embodiment). The plurality of detection units 21 and 22 of the detection means 20 are configured by known magnetic sensors using, for example, magnetoresistive elements or Hall elements, and output according to changes in the magnetic poles passing through the rotation detection positions P1 and P2, respectively. The signal is inverted.

  The plurality of detection units 21 and 22 are taken into a detection circuit 23 that constitutes an OR circuit, and the detection circuit 23 outputs a detection signal of a specific magnetic pole from at least one of the plurality of detection units 21 and 22. At this time, a rotation signal corresponding to the detection signal is output to an ECU (electronic control unit) (not shown).

  On the other hand, around the support member main body 12a of the pattern support member 12, an outer cylinder member 37 that is rotatably coupled to the support member main body 12a of the pattern support member 12 via a roller bearing 36 (bearing) is provided. The plurality of detection portions 21 and 22 of the detection means 20 are supported in the vicinity of the plurality of rotation detection positions P1 and P2 by sensor support portions 37i and 37j protruding from the outer cylinder member 37. Needless to say, the posture and position of the detection units 21 and 22 in the support state are such that the magnetic pole change in the encoder pattern 11a can be detected.

  Here, the roller bearing 36 has a pair of retainers 36b and 36c that hold a plurality of bearing rollers 36a, and is divided into a plurality at the same central angle as the divided bodies 31 and 32 of the pattern support member 12. The outer cylinder member 37 is also divided into a plurality of outer cylinder division bodies 37a and 37b at the same central angle as the division bodies 31 and 32 of the pattern support member 12, and the plurality of outer cylinder division bodies 37a and 37b are not shown. The outer cylinder member 37 is formed by being integrally fastened by a plurality of bolts.

  The outer cylinder member 37 is elastically connected to a lower suspension arm 43 (a part of a suspension device not shown in detail) positioned below the drive shaft 1 by a pair of front and rear tension coil springs 41 and 42. The rotation is always constrained by the downward biasing force on the vehicle front side and the downward biasing force on the vehicle rear side. Thereby, when the drive shaft 1 rotates, the outer cylinder member 37 has a plurality of detection units 21 and 22 of the detection means 20 with respect to the rotation of the pattern support member 12 and the encoder pattern 11a. The rotation detection positions P1 and P2 are held in a constant posture and position.

  As described above, the encoder pattern 11a is configured by a magnetic pattern in which N poles and S poles are alternately arranged at equal intervals in the circumferential direction, and the magnetic poles change periodically at a certain rotation angle. In the rotation detection positions P1 and P2, the magnetic pole detected at every fixed rotation angle (for example, 1 degree or 10 degrees) of the drive shaft 1 periodically changes, but the plurality of rotation detection positions P1 and P2 are It is set with a separation angle equal to or greater than the certain rotation angle.

  In addition, the encoder pattern 11a is disconnected at a fastening portion of the plurality of divided bodies 31 and 32 of the pattern support member 12 within an angle range narrower than the predetermined allowable breakage angles ga and gb. The positions P1 and P2 are set with a separation angle θs sufficiently larger than the allowable breakage angles ga and gb. And the some detection parts 21 and 22 of the detection means 20 each detect the change of a magnetic pole in several different rotation detection positions P1 and P2.

  The encoder pattern 11a has a plurality of continuous annular encoder patterns in a reading region (a portion outside the range of the allowable gaps ga and gb in FIG. 2) apart from the coupling portion of the plurality of divided bodies 31 and 32. The rotational phases of the magnetic patterns of the encoder pattern 11a1 on the divided body 31 and the encoder pattern 11a2 on the divided body 32 are aligned so as to form a pattern portion when the magnetic tape is bonded or when the magnetic pattern is formed.

  The drive shaft 1 is connected to a differential output portion of the transmission at one end in the axial direction via a constant velocity joint and is connected to the drive wheel side at the other end, together with a suspension arm (not shown) when the vehicle is running. Swing.

  Next, the operation will be described.

  In the rotation detection device of the present embodiment configured as described above, the encoder pattern 11a is interrupted at the joint portion of the plurality of divided bodies 31 and 32 on the circumferential surface where the encoder pattern 11a is arranged. .

  When the drive shaft 1 rotates in this state, the sensor A signal from one detection unit 21 and the sensor B signal from the other detection unit 22 among the plurality of detection units 21 and 22 of the detection unit 20 are respectively For example, it is output as a signal as shown in FIG.

  A portion surrounded by a dotted circle in the figure shows a change in the sensor A signal when the encoder pattern 11a is interrupted at the joint portion of the plurality of divided bodies 31 and 32. At this time, the sensor B signal is The signal has a constant period corresponding to the pitch between the magnetic poles.

  FIG. 5 shows an output pulse of the rotation signal output from the detection circuit 23 when the sensor A signal and the sensor B signal from the plurality of detection units 21 and 22 as shown in FIG. ing.

  As apparent from FIG. 5, when the sensor A signal and the sensor B signal are taken into the detection circuit 23 that constitutes the OR circuit, the detection circuit 23 receives a specific signal from at least one of the plurality of detection units 21 and 22. A rotation signal (signal corresponding to ON in FIG. 5) corresponding to the magnetic pole detection signal (signal corresponding to ON in FIG. 4) is output to the ECU side.

  As described above, in this embodiment, when the interrupted portion of the encoder pattern 11a reaches the rotation detection position P1 or P2 of any one of the detectors 21 or 22, a plurality of encoder pattern portions without the interrupt are plural. Among these, the detection position P2 or P1 of the other detection unit 22 or 21 is located, and any one of the plurality of detection units 21 and 22 can reliably detect the change in the encoder pattern 11a. Therefore, it is not necessary to perform complicated processing at the joint of the encoder pattern 11a. In addition, since the pattern support member 12 is composed of a plurality of divided bodies 31 and 32, it can be easily mounted on a detected body such as the drive shaft 1 having a circumferential surface.

  In the present embodiment, since the plurality of divided bodies are a pair of divided bodies 31 and 32 each having a semicircular cross section, the number of divided body coupling portions is reduced, and the configuration can be simply suppressed. Since the encoder pattern 11a is hardly interrupted and is supported symmetrically by the divided bodies 31 and 32, the required detection accuracy can be ensured.

  Furthermore, the encoder pattern 11a is formed so as to periodically change at a certain rotation angle corresponding to the detection unit angle, and a plurality of rotation detection positions P1, P2 are set with a separation angle equal to or greater than the certain rotation angle. Therefore, the encoder pattern 11a is simple and the pattern change becomes clear. Accordingly, reliable rotation detection can be performed, and the joint section of the encoder pattern can be easily set according to the change cycle of the encoder pattern 11a (a constant rotation angle corresponding to the detection unit angle).

  In addition, the encoder pattern 11a is interrupted at fastening portions of the plurality of divided bodies 31 and 32 of the pattern support member 12 within an angle range narrower than the predetermined allowable disconnection angles ga and gb, and a plurality of rotation detection positions P1 and P2. However, since it is set with a separation angle larger than the allowable break angles ga and gb, the encoder pattern 11a is interrupted at any one rotation detection position P1 or P2, and the interrupted state is continued within the allowable break angle. In the meantime, since the encoder pattern 11a is not interrupted at the other rotation detection positions P2 or P1, the magnetic pole change of the encoder pattern 11a can be reliably detected with high accuracy by one of the plurality of detection units 21 and 22. .

  In addition, the encoder pattern 11a is configured by a magnetic pattern in which the magnetic poles periodically change at a certain rotation angle, and the plurality of detection units 21 and 22 of the detection unit 20 are at different rotation detection positions P1 and P2. Since each change in the magnetic pole is detected, the rotation detection device can maintain better detection accuracy and reliability for moisture and dust than the optical detection method, and the cost of the magnetic encoder pattern 11a and the detection means 20 is increased. Can also be suppressed.

  Further, since the pattern holding unit 11 is made of a magnetic tape, the magnetic encoder pattern can be formed finely (in small increments) at low cost, and a high-resolution rotation detection device can be obtained.

  In the present embodiment, the pattern support member 12 further includes a cylindrical support member main body 12a, a flange portion 12b that is radially expanded from the support member main body 12a, and an outer periphery of the flange portion 12b. Since the encoder pattern 11a can be easily manufactured, the length of the encoder pattern 11a in the circumferential direction can be sufficiently secured, and the required detection accuracy can be secured. Become.

  In addition, an outer cylinder member 37 that is rotatably coupled to the support member main body 12a of the pattern support member 12 via a bearing 36 is provided, and the plurality of detection portions 21 and 22 of the detecting means 20 are provided by the outer cylinder member 37. Since it is configured to be supported in the vicinity of the rotation detection positions P1 and P2, a plurality of detection units 21 of the detection means 20 are used even if the rotating shaft that swings as well as the rotation is the detected object, such as the drive shaft 1. , 22 can be supported with a certain distance from the encoder pattern 11a, and detection is necessary not only for the encoder pattern 11a but also for the rotation axis, which is not easily detected from the point of sensor support. Thus, accurate rotation detection can be performed at the position.

  In the above-described embodiment, the pattern holding unit 11 formed of the magnetic tape on which the encoder pattern 11a is formed is slightly shorter than the length of the circumferential surface of each divided body 31 or 32. , The pattern holder itself of the encoder pattern such as a magnetic tape is continuous over substantially the entire outer periphery of the flange portion 12b of the pattern support member 12, and the joined portions of the divided bodies 31 and 32 on the outer periphery of the flange portion 12b. You may make it interrupt only in one place.

  Further, in that case, a concave portion is provided on the outer periphery of the flange portion 12b at the joint portion of the divided bodies 31 and 32, and the magnetic tape is bent to the radial inner side of the flange portion 12b of the pattern support member 12, or the magnetic tape is partially In other words, it may be covered with another member or an adhesive. That is, the magnetic tape itself does not necessarily need to be divided into a plurality of parts as long as the change in the encoder pattern is not detected partially and is interrupted.

  Further, the allowable break angles ga and gb of the encoder pattern 11a are preferably small to some extent. However, the encoder pattern 11a need not be within the shortest period (period corresponding to the detection unit angle) of the change of the encoder pattern 11a. The range can be set as described above.

  As described above, the present invention, even if the encoder pattern is interrupted at the joint portion of the plurality of divided bodies, when the interrupted portion reaches the rotation detection position of any one of the plurality of detection units, Since the encoder pattern is not interrupted at the rotation detection position of other detectors, and any of the detectors can reliably detect changes in the encoder pattern, the encoder pattern seams are complicated. In addition, since the pattern support member is composed of a plurality of divided bodies, it can be easily mounted on a detected object having a circumferential surface, and as a result, the joint of the encoder pattern Providing a rotation detection device with high detection accuracy that does not require complicated processing and can be easily mounted on a detection object having a circumferential surface. It is intended to achieve the effect that it is Rukoto, the rotation detecting device, which is particularly useful in a suitable rotation detecting device in general to magnetic rotary encoder.

It is the longitudinal section which shows schematic structure of the rotation detection apparatus which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows schematic structure of the detection means of the rotation detection apparatus which concerns on 1st Embodiment. It is a disassembled perspective view which shows the structure of the main components of the rotation detection apparatus which concerns on 1st Embodiment. FIG. 2 is an explanatory diagram of the operation of the rotation detection device according to the first embodiment, illustrating a sensor A signal output from one detection unit of the detection means and a sensor B signal output from the other detection unit at that time. is doing. FIG. 6 is an operation explanatory diagram of the rotation detection device according to the first embodiment, and shows an output pulse of a rotation signal output from the detection circuit when the sensor A signal and the sensor B signal of FIG. 4 are input to the detection circuit. ing.

Explanation of symbols

1 Drive shaft (detected object)
DESCRIPTION OF SYMBOLS 10 Rotation detection apparatus 11 Pattern holding part 11a Encoder pattern 12 Pattern support member 12a Support member main body 12b Flange part 12c Metal core part 13a, 13b Sheet part (elastic sheet)
20 detection means 21, 22 detection unit 23 detection circuit 31, 32 divided body (multiple divided bodies, a pair of divided bodies)
33 Bolt (fastening member)
34 Positioning pin 36 Roller bearing (bearing)
36a Bearing roller 36b, 36c Retainer 37 Outer cylinder member 37a, 37b Outer cylinder division 37i, 37j Sensor support 43 Lower suspension arm ga, gb Permissible breakage P1, P2 Rotation detection position θs Separation angle

Claims (8)

A pattern support member that has an annular pattern holding portion that holds an encoder pattern for rotation detection, and is supported by a detection target to detect rotation;
In the rotation detection device, comprising: a detecting unit that detects a change in the encoder pattern at a specific rotation detection position on a circumference around which the encoder pattern rotates when the pattern support member rotates together with the detection target object.
The pattern support member is constituted by a plurality of divided bodies each having an arcuate cross section, and the plurality of divided bodies are coupled to each other,
The detection means detects a change in the encoder pattern at a plurality of rotation detection positions that are spaced apart from the central angle of the arc-shaped cross section of the divided body on a circumference around which the encoder pattern rotates. A rotation detection device comprising a detection unit.   The rotation detection device according to claim 1, wherein the plurality of divided bodies are a pair of divided bodies each having a semicircular cross section.   The encoder pattern is formed so as to periodically change at a certain rotation angle, and the plurality of rotation detection positions are set with a separation angle equal to or greater than the certain rotation angle. The rotation detection device according to claim 1 or 2. The encoder pattern is discontinued within an angle range narrower than a predetermined discontinuity allowable angle at a fastening portion of the plurality of divided bodies of the pattern support member,
The rotation detection device according to any one of claims 1 to 3, wherein the plurality of rotation detection positions are set with a separation angle larger than the break-off allowable angle. The encoder pattern is composed of a magnetic pattern in which the magnetic poles periodically change at every fixed rotation angle,
5. The rotation detection device according to claim 3, wherein the plurality of detection units of the detection unit detect changes in the magnetic poles at the plurality of different rotation detection positions, respectively. 6.   The rotation detection device according to claim 5, wherein the pattern holding unit is formed of a magnetic tape.   The pattern support member is composed of a cylindrical support member main body, a flange portion that is radially expanded from the support member main body, and a pattern holding portion located on the outer periphery of the flange portion. The rotation detection device according to any one of claims 1 to 6, wherein the rotation detection device is provided.   An outer cylinder member that is rotatably coupled to a support member main body of the pattern support member via a bearing is provided, and the plurality of detection portions of the detection means are supported in the vicinity of the plurality of rotation detection positions by the outer cylinder member. The rotation detection device according to claim 7, wherein