JP4193795B2 - Encoder and rolling bearing unit with encoder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform fastening work for externally fitting and fixing an encoder 19d to a shoulder portion 35 of an inner ring 6 in the state in which the center axis of the encoder 19d corresponds to that of the inner ring 6. <P>SOLUTION: A supporting ring 20c constituting the encoder 19d has first and second cylindrical portions 44, 45. The first cylindrical portion 44 is externally fitted and fixed to the shoulder portion 35. During externally fitting and fixing work, the second cylindrical portion 45 is fitted into a circular recessed portion 43 of a press-in jig 42 with no looseness. In the state in which the center axis of the press-in jig 42 corresponds to the center axis of the inner ring 6, the pres-in jig 42 is pushed against the inner ring 6 and the first cylindrical portion 44 is externally fitted and fixed to the shoulder portion 35. Thus, the center axis of the press-in jig 42 accurately corresponds to that of the supporting ring 20c. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The rolling bearing unit with an encoder according to the present invention supports the wheel of an automobile so as to be rotatable with respect to the suspension device, and is used for detecting the rotational speed of the wheel in combination with a sensor for detecting the rotational speed. A rolling bearing unit with a rotational speed detecting device can be obtained by combining a rolling bearing unit with an encoder and a rotational speed detecting sensor installed on a stationary part such as a cover coupled to the outer ring.

  A rolling bearing unit is used to rotatably support the wheels of the automobile with respect to the suspension system. Further, in order to control the anti-lock brake system (ABS) and the traction control system (TCS), it is necessary to detect the rotational speed of the wheel. For this reason, the rolling bearing unit with a rotational speed detection device incorporating the rotational speed detection device in the rolling bearing unit can support the wheel rotatably with respect to the suspension device and detect the rotational speed of the wheel. In recent years, it has been widely performed.

  As a rolling bearing unit with a rotational speed detection device used for such a purpose, Patent Document 1 has a structure as shown in FIGS. 11 to 12, and Patent Document 2 has a structure as shown in FIG. Are listed. First, the rolling bearing unit 1 with the rotational speed detection device of the first example of the conventional structure shown in FIG. 11 is constructed by incorporating the rotational speed detection device 3 into the rolling bearing unit 2. Among these, the rolling bearing unit 2 is configured by rotatably supporting a hub 5 and an inner ring 6 on the inner diameter side of the outer ring 4. The outer end of the hub 5 (outside with respect to the axial direction means the outside in the width direction in the assembled state to the vehicle, and the left side of each figure except FIGS. 2, 7, and 9. On the contrary, FIGS. The first flange 7 for attaching the wheel to the outer peripheral surface of the right side of each figure except for the right side of each figure in the assembled state to the vehicle is referred to as the inside. A first inner ring raceway 8 is provided on each outer peripheral surface. The first inner ring raceway 8 may be provided integrally with the hub, or may be provided on the outer peripheral surface of the inner ring separate from the hub.

  The inner ring 6 has a second inner ring raceway 9 on the outer peripheral surface thereof, is formed near the inner end of the hub 5, and has an outer diameter dimension larger than that of the portion where the first inner ring raceway 8 is provided. The outer portion is fitted to the stepped portion 10 which has become smaller. A first outer ring raceway 11 facing the first inner ring raceway 8 and a second outer ring raceway 12 facing the second inner ring raceway 9 are arranged on the outer peripheral surface of the outer ring 4 on the inner peripheral surface. Second flanges 13 are formed for supporting the outer ring 4 on the suspension device. A plurality of rolling elements 14 and 14 are provided between the first and second inner ring raceways 8 and 9 and the first and second outer ring raceways 11 and 12, respectively. The hub 5 and the inner ring 6 are rotatably supported on the side. In the state where the inner ring 6 is externally fitted to the stepped portion 10, a nut 15 is screwed into a male screw portion formed at the inner end portion of the hub 5, and the inner ring 6 is held down. The separation from the hub 5 is prevented.

  Further, the opening of the inner end (right end in FIG. 11) of the outer ring 4 is closed by a cover 16. The cover 16 includes a bottomed cylindrical main body 17 formed by injection molding synthetic resin, and a fitting cylinder 18 coupled to an opening of the main body 17. The fitting cylinder 18 is joined to the opening of the main body 17 by molding the base end portion thereof at the time of injection molding of the main body 17. The cover 16 configured in this manner is configured such that the front half of the fitting cylinder 18 (the left half in FIG. 11) is fitted and fixed to the inner end of the outer ring 4 by an interference fit. The inner end opening is blocked.

  On the other hand, in order to constitute the rotational speed detection device, the encoder 19 is attached to the outer peripheral surface of the inner end portion of the inner ring 6 that is externally fitted and fixed to the inner end portion of the hub 5 at a portion that is separated from the second inner ring raceway 9. It is fitted and fixed. The encoder 19 includes a support ring 20 and a permanent magnet 21. Of these, the support ring 20 is formed by bending a magnetic metal plate such as a carbon steel plate such as SPCC, so that the whole is formed in an annular shape with an L-shaped cross section, and is fitted and fixed to the inner end of the inner ring 6 by an interference fit. ing. The permanent magnet 21 is formed by, for example, attaching rubber mixed with ferrite powder to the inner surface of the annular portion constituting the support ring 20 by baking or the like. The permanent magnet 21 is magnetized, for example, in the axial direction (left-right direction in FIG. 11), and the magnetization direction is changed alternately and at equal intervals in the circumferential direction. Therefore, the south pole and the north pole are alternately arranged at equal intervals in the circumferential direction on the inner surface of the encoder 19, which is the detected portion.

  Further, a part of the main body 17 constituting the cover 16 and a portion facing the inner surface of the permanent magnet 21 constituting the encoder 19 are inserted with an insertion hole 22 through the main body 17 so that the outer ring 1 is inserted. Is formed in the axial direction. A sensor 23 (including a sensor unit in which a detection element or the like is embedded in a synthetic resin is included) is inserted into the insertion hole 22. This sensor 23 is an IC incorporating a magnetic detecting element such as a Hall element, a magnetoresistive element (MR element) or the like that changes its output in accordance with the flow direction of magnetic flux, and a waveform shaping circuit for adjusting the output waveform of the magnetic detecting element. And a pole piece made of a magnetic material for guiding the magnetic flux from the permanent magnet 21 (or flowing into the permanent magnet 21) to the magnetic detection element is embedded in a synthetic resin.

  Such a sensor 23 is provided near the distal end (the left end in FIG. 11), and has a cylindrical insertion portion 24 that can be inserted through the insertion hole 22 without rattling, and a base end portion (see FIG. 11). 11 and the flange portion 25 having an outward flange shape. A locking groove is formed on the outer peripheral surface of the intermediate portion of the insertion portion 24, and an O-ring 26 is locked in the locking groove.

  On the other hand, a part of the outer surface of the cover 16 (the right side surface in FIG. 11 on the side surface opposite to the space 27 in which the rolling elements 14 and 14 are installed, which should be closed by the cover 16), and around the opening of the insertion hole A locking cylinder 28 is provided in the part. The sensor 23 is inserted into the locking cylinder 28 by the insertion portion 24 and the locking cylinder 29 is pressed against the distal end surface of the locking cylinder 28 by the locking spring 29. 28 is bonded and supported. Incidentally, such a coupling support structure by the locking spring 29 is described in detail in the above-mentioned patent document 1 and is not related to the gist of the present invention, and therefore detailed illustration and description are omitted.

  When the rolling bearing unit with a rotational speed detection device as described above is used, the second flange 13 fixed to the outer peripheral surface of the outer ring 4 is coupled and fixed to a suspension device by a bolt (not shown), and the hub 5 By fixing the wheel to the first flange 7 fixed to the outer peripheral surface of the first flange 7 by the stud 30 provided on the first flange 7, the wheel is rotatably supported with respect to the suspension device. When the wheel rotates in this state, the N pole and the S pole existing on the inner surface of the permanent magnet 21 alternately pass through the vicinity of the end face of the detection portion of the sensor 23. As a result, the direction of the magnetic flux flowing through the sensor 23 changes, and the output of the sensor 23 changes. The frequency at which the output of the sensor 23 changes in this way is proportional to the rotational speed of the wheel. Therefore, if the output of the sensor 23 is sent to a controller (not shown), the ABS and TCS can be appropriately controlled.

  In the case of the second example of the conventional structure described in Patent Document 1 shown in FIG. 12, a cylindrical portion 31 is formed at the inner end of the hub 5a, and the inner ring 6a is formed at the tip of the cylindrical portion 31. A caulking portion 34 is formed by caulking and extending a portion protruding from the inner end surface outward in the diameter direction, and the caulking portion 34 joins and fixes the inner ring 6a to the hub 5a. If such a structure is employed, the number of parts can be reduced and the assembly can be reduced as compared with the structure in which the inner ring 6 is coupled and fixed to the hub 5 by the nut 15 as in the first example of the conventional structure shown in FIG. The cost can be reduced by reducing the labor. In the case of the second example of the conventional structure shown in FIG. 12, the structure of the portion where the sensor 23a is coupled and supported to the locking cylinder 28 provided on the main body 17 of the cover 16 by the locking spring 29a is the first described above. Different from the example. However, such a coupling support structure by the locking spring 29a is also described in detail in the above-mentioned patent document 1 and is not related to the gist of the present invention, and therefore detailed illustration and description thereof are omitted.

  In the case of the structure of the second example, the encoder 19a is also different from the case of the first example. That is, the encoder 19a of the present example is formed by bending a magnetic metal plate such as a mild steel plate so that the cross-sectional shape is an L shape having an annular portion 32, and the whole is formed in an annular shape. A plurality of through holes 33 are formed radially in the annular portion 32, and the magnetic characteristics of the annular portion 32 are changed alternately and at equal intervals in the circumferential direction. In accordance with this, the internal structure of the sensor 23a is also different from that of the first example described above. In the case of the structure of the second example, a small diameter step portion 36 is formed in the inner half portion of the shoulder portion 35 provided at the inner end portion of the inner ring 6a, and the inner diameter of the encoder 19a is formed in the small diameter step portion 36. A cylindrical portion 37 formed on the peripheral edge portion is externally fitted by an interference fit. By adopting such a structure, the width dimension in the radial direction of the annular portion 32 is secured, and the output of the sensor 23a facing the inner surface of the annular portion 32 can be secured.

  Further, in the case of the third example of the conventional structure shown in FIG. 13, the encoder 19b that is fitted and fixed to the inner end of the inner ring 6a is supported by a magnetic metal plate as in the case of the first example. The ring 20a and the permanent magnet 21 are combined. Of these, the support ring 20 a is formed in a circular shape with a T-shaped cross section, and includes a fitting cylinder portion 38 and an annular portion 39. The permanent magnet 21 is attached to the inner side surface of the annular ring portion 39. Such an encoder 19b is supported and fixed to the inner end portion of the inner ring 6a by fitting the fitting cylinder portion 38 to the outer peripheral surface of the shoulder portion 35 provided at the inner end portion of the inner ring 6a by an interference fit. is doing. In this state, the permanent magnet 21 is made to enter a small diameter step portion 36 provided in the inner half portion of the shoulder portion 35 at a portion near the inner periphery.

  On the other hand, the inner end opening of the outer ring 4 is closed by fitting and fixing a bottomed cylindrical cover 16a formed of a metal plate such as a steel plate or stainless steel plate to the inner end of the outer ring 4. The sensor 23b is held and fixed inside the cover 16a while being embedded in the synthetic resin 40. In this state, the sensor 23b is opposed to a part of the permanent magnet 21 in the circumferential direction through a minute gap. Also in the case of the rolling bearing unit with the rotational speed detection device of the present example configured as described above, the width dimension in the diameter direction of the permanent magnet 21 constituting the encoder 19b is increased, and the permanent magnet 21 extends in the circumferential direction. It is possible to increase the change in magnetic characteristics and improve the accuracy of rotation speed detection by the rotation speed detection device.

The present invention was invented to prevent the inner surface of the permanent magnet 21 from being damaged when transported from an encoder manufacturing factory to an encoder rolling bearing unit assembly factory. That is, when transporting from the encoder manufacturing factory to the encoder rolling bearing unit assembly factory, the encoder 19b is externally fitted to the holding cylinder. In this case, in order to improve the efficiency of the work at the assembly factory of the roller bearing unit with encoder, all the encoders 19b are fitted in the holding cylinder in the same direction and overlapped in the axial direction.

In this manner, when the encoders 19b are overlapped in the axial direction and the axial ends of the adjacent encoders 19b are in contact with each other, the permanent magnet 21 is not a smooth surface but a cut surface by pressing. When a portion with sharp fine irregularities comes into contact, the inner surface of the permanent magnet 21 may be damaged by vibrations applied during conveyance.

Japanese Patent Laid-Open No. 11-23596 Japanese Patent Laid-Open No. 10-332723

In the rolling bearing unit with an encoder of the present invention, in view of the circumstances as described above, the inner surface of the permanent magnet constituting the encoder may be damaged when the encoder rolling factory unit is transported to the assembly factory. It was invented to realize a structure that can be prevented .

Of the encoder and the rolling bearing unit with an encoder according to the present invention, the encoder according to claim 1 bends the magnetic metal plate in the same manner as the encoder incorporated in the above-described conventionally known rolling bearing unit with an encoder. An annular support ring having a cylindrical part and an annular part, and a permanent magnet attached to a side surface of the annular part of the support ring. And this permanent magnet and the said cylindrical part have mutually overlapped regarding the axial direction. And it uses in the state which carried out external fitting fixation of this cylindrical part to the inner ring.
In particular, in the encoder according to the present invention , a bent portion or a bent portion that is bent or folded radially outward at the tip edge of the cylindrical portion of the support ring that is in the axially opposite position to the permanent magnet. Forms a folded portion.

In addition, the rolling bearing unit with an encoder according to claim 2 includes a rolling bearing unit and an encoder, similarly to the above-described rolling bearing unit with an encoder.
Of these, the rolling bearing unit is provided with a first flange for mounting a wheel on the outer peripheral surface of the outer end portion, and a first inner ring raceway on the outer peripheral surface of the axially intermediate portion, either directly or via a separate inner ring. A second inner ring raceway formed on the outer peripheral surface of the hub, and a step portion provided at the inner end of the hub and having a smaller outer diameter than the portion provided with the first inner ring raceway. To support the outer ring on the outer ring, the first outer ring raceway facing the first inner ring raceway and the second outer ring raceway facing the second inner ring raceway on the outer peripheral surface on the outer peripheral surface. A plurality of rolling elements each provided between the outer ring, the first and second inner ring raceways, and the first and second outer ring raceways. With.
In addition, the encoder has a ring-shaped detected portion in which the magnetic characteristics of the inner surface are alternately changed in the circumferential direction, and is a portion deviated from the second inner ring track on the outer peripheral surface of the inner end of the inner ring. The inner ring is fixed concentrically.
In particular, in the rolling bearing unit with an encoder of the present invention, the encoder is the encoder described in claim 1 described above.

The encoder and the rolling bearing unit with an encoder of the present invention configured as described above are configured such that a plurality of encoders are overlapped in the axial direction, and axial end portions of adjacent encoders are outside the bent portion or the folded portion. The side surface contacts the inner surface of the permanent magnet. The outer surface of the bent portion or the folded portion is not a cut surface obtained by pressing, but is a smooth surface, and the outer surface portion does not have sharp fine irregularities. Therefore, the inner surface of the permanent magnet is not damaged regardless of vibrations applied during conveyance.

1-3 have shown the 1st example of the reference example regarding this invention. The feature of this reference example is that the shape of the support ring 20c constituting the encoder 19d is devised so that the encoder 19d and the inner ring 6 are aligned with the central axis of the encoder 19d and the central axis of the inner ring 6. It is in the point which makes it possible to fix by external fitting . Hereinafter, the characteristic part of this reference example will be mainly described.

The encoder 19d is a combination of the support ring 20c and an annular permanent magnet 21. Of these, the support ring 20 c is formed in an annular shape as a whole, and includes first and second cylindrical portions 44 and 45, a continuous portion 46, and an annular portion 47. Of these, the first cylindrical portion 44 is provided at the outer end portion, and is fitted and fixed to the shoulder portion 35 provided at the inner end portion of the inner ring 6 by an interference fit in the assembled state. The second cylindrical portion 45 is provided concentrically with the first cylindrical portion 44 at the inner end, and in the case of this reference example , has a larger diameter than the first cylindrical portion 44. Yes. The continuous portion 46 is formed by connecting the inner end edge of the first cylindrical portion 44 and the outer end edge of the second cylindrical portion 45. In the case of this reference example , the continuous portion 46 is formed in a partially conical cylindrical shape. is doing. Further, the annular portion 47 is formed on the same side as the continuous portion 46 in the radial direction from the inner end edge of the second cylindrical portion 45, or on the inner diameter side in the case of this reference example , on the second cylindrical portion 45. It is bent at a right angle to.

Such a support ring 20c is integrally formed by bending and forming a magnetic metal plate such as a carbon steel plate or a stainless steel plate in a process as shown in FIG. That is, first, a circular base plate 48 as shown in FIG. 2A is obtained by punching a metal plate as a material. Next, by drawing the base plate 48, a petri-shaped first intermediate material 49 as shown in FIG. The cylindrical portion formed on the outer peripheral edge of the first intermediate material 49 is the second cylindrical portion 45. Next, the first intermediate material 49 is subjected to the first stage curl processing, and the second intermediate material 50 as shown in FIG. The third intermediate material 51 as shown is assumed. The cylindrical portion present in the opening of the third intermediate material 51 becomes the first cylindrical portion 44. Finally, the bottom central portion of the third intermediate material 51 is punched out, and the bottom portion is used as the circular ring portion 47 to complete the support ring 20c as shown in FIG. It should be noted that the punching of the bottom center portion can be performed immediately after the formation of the first intermediate material 49 or the second intermediate material 50, and at the same time as the punching of the base plate 48. The encoder 19d is attached to the inner surface of the annular portion 47 of the support ring 20c thus manufactured concentrically with the annular portion 47, and the inner surface of the annular portion 47 is connected to the S pole. It is assumed that the detected parts are alternately arranged with N poles.

The rolling bearing unit with an encoder of the present reference example configured by incorporating the support ring 20c as described above uses the second cylindrical portion 45, whereby the central axis of the encoder 19d and the central axis of the press-fitting jig 42 are used. Can be matched. That is, by inserting the second cylindrical portion 45 having a sufficiently large axial dimension as compared with the conventional structure into a circular recess 43 provided in the press-fitting jig 42, the central axis of the press-fitting jig 42 is obtained. And the center axis of the encoder 19d can be matched. In this case, it is necessary to make the outer diameter of the second cylindrical portion 45 substantially coincide with the inner diameter of the circular recess 43, but it is easy to make these dimensions coincide with each other.

  In this way, if the second cylindrical portion 45 having an outer diameter substantially coincident with the inner diameter of the circular recess 43 is fitted into the circular recess 43 without looseness as shown in FIG. And the center axis of the press-fitting jig 42 automatically coincide with each other. As long as the second cylindrical portion 45 does not come out of the circular concave portion 43, the central axis of the encoder 19d and the central axis of the press-fitting jig 42 are kept matched regardless of an external force such as gravity. Is done. Therefore, by pressing the press-fitting jig 42 against the inner ring 6 in a state where the central axis of the press-fitting jig 42 and the central axis of the inner ring 6 coincide with each other, a shoulder provided at the inner end of the inner ring 6 is provided. The first cylindrical portion 44 of the support ring 20c constituting the encoder 19d can be fitted and fixed to the portion 35 in a state where the central axis of the encoder 19d and the central axis of the inner ring 6 are aligned. In addition, the leading edge of the first cylindrical portion 44 does not bite the outer peripheral surface of the shoulder portion 35 with the external fitting fixing work. In addition, as described above, since the two central axes can be prevented from being inconsistent even when an external force is applied, compared to the case where the two central axes are matched with each other using the magnetic force of the permanent magnet 21. Sometimes the function of preventing the tilt of the encoder 19d is ensured.

4 to 5 show a second example of the reference example related to the present invention. In the case of this reference example , the diameter relationship between the first and second cylindrical portions 44a and 45a constituting the support ring 20d of the encoder 19e is reversed from that in the case of the reference example 1 described above. That is, in the case of this reference example , the inner end edge of the relatively large-diameter first cylindrical portion 44a and the outer end edge of the relatively small-diameter second cylindrical portion 45a are connected to a partially conical cylindrical continuous portion. It is made continuous by 46a. An annular portion 47a for installing the permanent magnet 21 is bent at a right angle outward from the inner end edge of the second cylindrical portion 45a.

  When the first cylindrical portion 44a of the support ring 20d of the encoder 19e as described above is externally fitted and fixed to the shoulder portion 35 of the inner ring 6, a circular convex portion 52 is formed at the center portion of the outer surface as shown in FIG. The provided press-fitting jig 42a is used. And in the state where the second cylindrical portion 45a is externally fitted to the circular convex portion 52 without rattling, the central axis of the press-fitting jig 42a and the central axis of the inner ring 6 are kept in agreement with each other. The press-fitting jig 42a is pressed against the inner ring 6. As a result, the encoder 19e is externally supported with respect to the inner ring 6 in a state where the center axes of the encoders 19e coincide with each other.

FIGS. 6-7 has shown the 3rd example of the reference example regarding this invention. Among the reference examples, the basic shape of the support ring 20e constituting the encoder 19f is the same as that of the reference example 1 described above. However, in the case of this reference example , the continuous part 46b which comprises the said support ring 20e is formed in the orthogonal | vertical direction with respect to the 1st, 2nd cylindrical parts 44 and 45. FIG. Therefore, the continuous portion 46b and the annular ring portion 47 are parallel to each other.

The structure of this reference example is different from the reference example 1 and the reference example 2 described above in that the cover 16b that closes the inner end opening of the outer ring 4 and the sensor 23c attached to the cover 16b. . First, in order to constitute the cover 16b, the fitting cylinder 18a made of a metal plate inserted into the opening of the synthetic resin main body 17a protrudes from the inner peripheral edge of the opening of the main body 17a. In order to increase the inner diameter of the cover 16b as much as possible with such a structure, the inner peripheral surface of the fitting cylinder 18a is exposed to the inner peripheral surface of the cover 16b over the entire axial length. In addition, a plurality of through holes are formed in the outward flange-like flange portion formed at the base end portion (inner end portion, right end portion in FIG. 6) of the fitting cylinder 18a so as to penetrate in the axial direction. By allowing the synthetic resin constituting the main body 17a to flow into the through hole, the coupling strength between the main body 17a and the fitting cylinder 18a is secured. In the state where the inner end opening of the outer ring 4 is closed by the cover 16b having such a configuration, the fitting cylinder 18a is fitted into the inner end of the outer ring 4 with an interference fit, and the front end of the main body 17a. The surface is abutted against the inner end surface of the outer ring 4. And this abutting part is sealed with an O-ring. The inner peripheral side surface of the fitting cylinder 18a constitutes the inner diameter side surface of the locking groove for mounting the O-ring.

  Further, in order to install the insertion hole 22a formed in the cover 16b as far as possible in the radial direction for mounting the sensor 23c, a part of the peripheral wall 53 constituting the cover 16b corresponds to the insertion hole 22a. The portion protrudes radially outward from the other portions. However, the opening half (outer half) of the peripheral wall 53 needs to form a locking groove for molding the base half of the fitting cylinder 18a and locking the O-ring. In addition to being thicker than the part, it is formed in a simple cylindrical shape whose diameter does not change midway. For this reason, a stepped portion is formed on the peripheral wall 53 side portion at the end portion on the space 27 side of the opening portions at both ends of the insertion hole 22a. On the other hand, a circumferential step portion 54 is formed at a portion of the peripheral wall 53 that is out of the insertion hole 22a at the intermediate portion of the outer peripheral surface. The circumferential step portion 54 pushes the front end surface of the pressing jig when the fitting tube 18a is press-fitted into the inner end portion of the outer ring 4 so as to block the inner end opening portion of the outer ring 4 with the cover 16b. Use to hit. Since the circumferential step portion 54 is discontinuous at the insertion hole 22a portion, the pressing portion of the pressing jig has a partially cylindrical shape with the discontinuous portion missing. Since the discontinuous portion is only a part in the circumferential direction, the presence of the discontinuous portion does not cause a problem in the press-fitting operation.

The reason why the insertion hole 22a is installed near the outer diameter of the cover 16b with such a structure is to increase (strong) the magnetic flux flowing through the sensor 23c and improve the reliability of rotation speed detection. That is, since the magnetized areas of the permanent magnets 21 constituting the encoder 19f are each fan-shaped, the width dimension in the circumferential direction becomes wider outward in the radial direction. The intensity of the magnetic flux that exits from the inner surface of the permanent magnet 21 that is the detected surface and reaches the sensor 23c increases as the width dimension increases and the magnetization area increases. From this point of view, in the case of the present reference example , the insertion hole 22a is disposed closer to the outer diameter of the cover 16b.

Particularly in the case of this reference example , the insertion portion 55 to be inserted into the insertion hole 22a of the sensor 23c has a cylindrical shape, and the insertion portion 55 serves as a detection portion of the sensor 23c, as shown in FIG. A rectangular IC 56 is embedded. Accordingly, the structure must be such that the IC 56 does not exist at the radially outermost position of the sensor 23c. In order to improve the rotational speed detection performance, it is necessary to dispose the IC 56 and the inner surface of the permanent magnet 21 as radially outward as possible so that the opposing area of both is as large as possible. For this reason, in the case of a structure in which a rectangular IC 56 is embedded in a cylindrical insertion portion 55 and an insertion portion 55 that is located closer to the outer diameter than the IC 56 is provided in the radial direction of the cover 16b. As in the structure of this reference example , it is important to increase the facing area between the IC 56 and the inner surface of the permanent magnet 21.

Further, in the case of this reference example, the sensor 23c having a mounting flange 57 at the base end portion (the right end portion and the inner end portion in FIG. 6) of the insertion portion 55 is used. In order to assemble the sensor 23c to the cover 16b, the distal end portion (the lower end portion in FIG. 6) of the mounting flange 57 is provided at the center of the cover 16b with the insertion portion 55 inserted into the insertion hole 22a. The screw holes 58 are coupled with bolts 59. The watertightness between the outer peripheral surface of the insertion portion 55 and the inner peripheral surface of the insertion hole 22a is held by an O-ring locked in the locking groove on the outer peripheral surface of the intermediate portion of the insertion portion 55, and the screw hole 58 The watertightness of the part is held by a blind plate 60 formed at the back end of the screw hole 58.

  In order to form the screw hole 58, the blind plate 60 is molded in the main body 17a together with the nut piece 61 when the nut piece 61 is inserted into the center portion of the main body 17a of the cover 16b. That is, the blind plate 60 formed in a hat shape is abutted against an opening of one end (the left end in FIG. 6) of the nut piece 61, and is fixedly coupled by spot welding or the like. A number of protrusions are formed on the outer peripheral surface of the nut piece 61, and in a state where the nut piece 61 is molded on the main body 17a, the nut piece 61 is rotated axially with respect to the main body 17a. Is not displaced. When such a nut piece 61 is molded in the central portion of the main body 17a, a positioning projection protruding into the cavity of the injection mold is inserted into the concave portion formed in the central portion of the blind plate 60, With the nut piece 61 positioned, the main body 17a is injection molded.

  A portion where the synthetic resin does not exist is formed in a portion that is aligned with the screw hole 58 formed by the nut piece 61 at the center portion of the main body 17a by inserting the positioning protrusion into the concave portion. It is blocked by the blind plate 60. Therefore, foreign matter such as rainwater does not enter the cover 16b through the screw hole 58. The nut piece 61 may have a bottomed cylindrical shape, and the blind plate 60 may be omitted. Furthermore, the positioning of the nut piece 61 when the main body 17a is injection-molded can be performed only by another positioning projection inserted into the nut piece 61 from the inner end (right end in FIG. 6) opening of the nut piece 61. Thus, if the discontinuous portion of the synthetic resin is eliminated from the central portion of the main body 17a, the entry of the foreign matter can be more reliably prevented. However, even in this case, in order to prevent the synthetic resin from entering the screw hole 58, it is necessary to provide the blind plate 60 or use a bottomed cylindrical one as the nut piece 61. .

FIG. 8 shows an embodiment of the present invention. This embodiment and Reference Example 4 to be described later are based on the premise that the detected portion of the encoder is made of a permanent magnet made of a material softer than a metal such as a rubber magnet or a plastic magnet. And it is set as the structure which prevents that the said permanent magnet is damaged when conveying only the encoder in the state piled up in the axial direction. The reason for such consideration is as follows.

From the encoder manufacturing plant to the assembly plant of the rolling bearing unit with encoder, a large number of encoders are externally or internally fitted in a holding cylinder such as a paper cylinder in order to improve the efficiency of transportation work (to make it compact and not bulky). Then, it is conveyed in the state of being overlapped in the axial direction. In this case, in order to improve the efficiency of the work at the assembly factory of the rolling bearing unit with encoder, all the encoders are oriented in the same direction and are fitted or fitted into the holding cylinder. That is, the trouble of the direction alignment at the time of assembling work, which occurs when they are alternately stacked, is eliminated. Therefore, in the case of the structure of the reference example 1 shown in FIG. 1 described above, the permanent magnet 21 and the first cylindrical portion 44 of the support ring 20c overlap each other in the axial direction. The edge of 20c hits the permanent magnet 21 of the adjacent encoder 19d. At the edge of the support ring 20c, there are fine and pointed irregularities based on burrs generated when the support ring 20c is cut by pressing as shown in FIG. For this reason, there is a possibility that the surface of the permanent magnet 21 may be damaged due to vibration during transportation. And when a remarkable crack is attached, it becomes difficult to ensure the reliability of rotation speed detection by the encoder 19d.

In view of such circumstances, in the case of the embodiment shown in FIG. 8 and Reference Example 4 described later, a plurality of encoders each combining a support ring and a permanent magnet formed by bending a metal plate, When overlapping in the axial direction toward the same direction, the end edge (cutting edge) of the metal plate is prevented from coming into contact with the permanent magnet.

First, in the case of the embodiment shown in FIG. 8, the end portion of the first cylindrical portion 44 of the support ring 20f constituting the encoder 19g is bent or folded 90 to 180 degrees radially outward. A bent portion 62 or a folded portion is formed at the outer end portion of the first cylindrical portion 44. Such an encoder 19g is externally fitted to the holding cylinder 63 as shown in FIG. 9 so as to be conveyed from the encoder manufacturing factory to the assembly factory of the rolling bearing unit with encoder. In this case, all the encoders 19g and 19g are externally fitted to the holding cylinder 63 in the same direction and overlapped in the axial direction in order to improve the efficiency of work in the assembly factory of the roller bearing unit with encoder.

With the encoders 19g and 19g overlapped in the axial direction in this way, the axial ends of the adjacent encoders 19g and 19g are brought into contact with the outer surface of the bent portion 62 and the inner surface of the permanent magnet 21. Touch. The outer surface of the bent portion 62 is not a cut surface by press working but a smooth surface, and the outer surface portion has no sharp fine irregularities. Therefore, the inner surface of the permanent magnet 21 is not damaged regardless of vibrations applied during conveyance. Note that when the outer end portion of the first cylindrical portion 44 is folded back 180 degrees densely, the outer end edge of the folded portion abuts against the permanent magnet 21. Even in this case, since there are no sharp irregularities on the outer edge of the folded portion that damage the inner surface of the permanent magnet 21, damage to the permanent magnet 21 can be prevented. In the case of this embodiment, the permanent magnet 21 covers the outer peripheral surface of the second cylindrical portion 45 and the inner peripheral edge of the annular portion 47 constituting the support ring 20f, thereby ensuring the dimensional accuracy of the encoder 19g. However, the cost of the mold is reduced. That is, the encoder 19g having the required dimensional accuracy can be obtained without extremely increasing the dimensional accuracy of the support ring 20f and the mold. Since the configuration and operation of the other parts are the same as those in the case of the reference example 1 shown in FIG. 1 described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

FIG. 10 shows Reference Example 4 relating to the present invention. In the case of this reference example 4 , the edge and outer peripheral surface of the 1st cylindrical part 44 of the support ring 20g which comprise the encoder 19h are covered with soft materials 64, such as rubber | gum. In this way, since the edge of the first cylindrical portion 44 is covered with the soft material 64, a plurality of encoders 19h are arranged in the axial direction so as to be conveyed from the encoder manufacturing factory to the assembly factory of the rolling bearing unit with encoder. In the overlapped state, the axial ends of the encoders 19 h adjacent to each other come into contact with the soft material 64 and the inner surface of the permanent magnet 21. Therefore, the inner surface of the permanent magnet 21 is not damaged regardless of vibrations applied during conveyance.

  Note that rubber is preferably used as the soft material 64, but whether the material of the permanent magnet 21 is changed or not depends on when the permanent magnet 21 is magnetized. When this magnetizing operation is performed before the encoder 19h is fitted on the inner ring 6, a general rubber (which may be a synthetic resin) that does not contain ferromagnetic powder such as ferrite is used as the soft material 64. use. The reason for this is that the magnetized permanent magnet 21 and the soft material 64 prevent the encoders 19h that are overlapped in the axial direction from being easily separated from each other and prevent the rolling bearing unit with the encoder from being assembled. This is to improve efficiency. Therefore, in this case, the permanent magnet 21 and the soft material 64 are molded separately.

  On the other hand, when the magnetizing operation is performed after the encoder 19h is externally fitted to the inner ring 6, the soft material 64 includes a ferromagnetic powder such as ferrite as in the permanent magnet 21. Is used. The reason is that the permanent magnet 21 and the soft material 64 are simultaneously molded to improve the efficiency of the molding operation and reduce the cost. Since the magnetizing operation is performed after the outer fitting to the inner ring 6, it is not difficult to separate the encoders 19h that are stacked in the axial direction and are adjacent to each other.

Sectional drawing which shows the reference example 1 regarding this invention. Sectional drawing which shows one example of the manufacturing method of the support ring integrated in Reference Example 1 in order of a process. The fragmentary sectional view which shows the state which carries out the external fitting fixation of the encoder comprised including this support ring to an inner ring | wheel. Sectional drawing which shows the reference example 2 regarding this invention. The fragmentary sectional view which shows the state which carries out external fitting fixation of the encoder to an inner ring | wheel so that the structure of the reference example 2 may be assembled. Sectional drawing which shows the reference example 3 regarding this invention. The schematic which shows the installation state of IC which comprises the sensor integrated in the reference example 3 in the state seen from the side of FIG. Sectional drawing which shows the Example of this invention. Sectional drawing which shows the state which piled up the encoder incorporated in an Example in the axial direction. Sectional drawing which shows the reference example 4 regarding this invention. Sectional drawing which shows the 1st example of a conventional structure. The fragmentary sectional view which shows the 2nd example. The fragmentary sectional view which shows the 3rd example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling bearing unit with a rotational speed detection apparatus 2 Rolling bearing unit 3 Rotational speed detection apparatus 4 Outer ring 5, 5a Hub 6, 6a Inner ring 7 First flange 8 First inner ring track 9 Second inner ring track 10 Step part 11 First One outer ring raceway 12 Second outer ring raceway 13 Second flange 14 Rolling element 15 Nut 16, 16a, 16b Cover 17, 17a Main body 18, 18a Fitting cylinders 19, 19a , 19b, 19d to 19h Encoder 20, 20a, 20c to 20g Support ring 21 Permanent magnet 22, 22a Insertion hole 23, 23a to 23c Sensor 24 Insertion part 25 Gutter part 26 O-ring 27 Space 28 Locking cylinder 29, 29a Locking spring 30 Stud 31 Cylindrical part
32 circular ring part 33 through hole 34 caulking part 35 shoulder part 36 small diameter step part
37 cylindrical part 38 fitting cylinder part 39 annular part 40 synthetic resin
42 , 42a Press-fitting jig 43 Circular recess 44, 44a First cylindrical portion 45, 45a Second cylindrical portion 46, 46a, 46b Continuous portion 47, 47a Annular portion 48 Base plate 49 First intermediate material 50 Second intermediate Material 51 Third intermediate material 52 Circular convex part 53 Perimeter wall 54 Peripheral step part 55 Insertion part 56 IC
57 Mounting flange 58 Screw hole 59 Bolt 60 Blind plate 61 Nut piece 62 Bending part 63 Holding cylinder 64 Soft material

Claims (2)

A support ring that is formed by bending a magnetic metal plate and has a cylindrical portion and an annular portion, and a permanent magnet attached to the side surface of the annular portion of the support ring, and the permanent magnet In the encoder used in a state where the cylindrical portion overlaps with each other in the axial direction and the cylindrical portion is fitted and fixed to the inner ring, the cylindrical portion of the support ring is opposite to the permanent magnet in the axial direction. An encoder characterized in that a bent portion or a folded portion , which is bent or folded outward in a radial direction , is formed at a tip edge existing at a position. The first flange for mounting the wheel on the outer peripheral surface of the outer end, the first inner ring raceway on the outer peripheral surface in the axial direction, or the hub provided on the outer peripheral surface either directly or via a separate inner ring Forming an inner ring raceway, an inner ring fitted on a step portion provided on the inner end of the hub and having a smaller outer diameter than the portion provided with the first inner ring raceway, and an inner circumference A second flange for supporting the first outer ring raceway facing the first inner ring raceway and the second outer ring raceway facing the second inner ring raceway on the surface, and a suspension on the outer peripheral surface, respectively. A rolling bearing unit comprising: an outer ring formed; and a plurality of rolling elements each provided between the first and second inner ring raceways and the first and second outer ring raceways so as to freely roll. The sensor has a ring-shaped detected part in which the magnetic properties of the inner surface are changed alternately in the circumferential direction. The portion outside the inner end portion outer peripheral surface of the inner ring from the second inner ring raceway, at the encoder rolling bearing unit with an encoder which is fixed to the inner ring concentrically, wherein the encoder to claim 1 encoder rolling bearing unit, characterized in that it is the encoder.

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