JP6256122B2 - Rolling bearing unit with rotational speed detector - Google Patents

Description

  The present invention relates to an improvement in a rolling bearing unit with a rotational speed detecting device for rotatably supporting a vehicle wheel (driven wheel) with respect to a suspension device and detecting the rotational speed of the wheel.

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

  As an example of a conventional structure of a rolling bearing unit with a rotational speed detection device used for such a purpose, Patent Document 1 describes a structure as shown in FIGS. This rolling bearing unit 1 with a rotational speed detection device having a conventional structure rotatably supports a hub 3 as a rotating ring on the inner diameter side of an outer ring 2 as a stationary ring.

  Outer ring 2 has double-row outer ring raceways 4a and 4b on the inner peripheral surface and stationary flange 5 on the outer peripheral surface. Further, the outer ring 2 is supported and supported by a knuckle (not shown) that constitutes a suspension device in use.

  The hub 3 is a combination of a hub body 6 and an inner ring 7. The hub 3 has double-row inner ring raceways 8 a and 8 b on the outer peripheral surface, and is supported concentrically with the outer ring 2 on the inner diameter side of the outer ring 2. Yes. Specifically, the inner ring raceway 8a in the axially outer row is directly formed at the axially intermediate portion of the outer peripheral surface of the hub body 6, and also the inner end of the axial direction (the inner side in the axial direction is assembled to the suspension device. In the state, it refers to the side closer to the center of the vehicle body in the width direction, and the outside in the axial direction refers to the side closer to the vehicle body in the width direction, which is the same throughout the present specification and claims.) The inner ring 7 having the inner ring raceway 8b in the axially inner row formed on the outer peripheral surface is externally fitted and fixed to the small-diameter step portion 9 formed on the outer periphery. The axial inner end surface of the inner ring 7 is held down by a caulking portion 10 formed by plastically deforming the axial inner end of the hub body 6 radially outward. A rotation-side flange 11 for supporting the wheel is provided at a portion of the hub body 6 that protrudes outward in the axial direction from the axial outer end opening of the outer ring 2 at the axial outer end. Yes.

  A plurality of rolling elements 12, 12 are provided between the outer ring raceways 4a, 4b and the inner ring raceways 8a, 8b, respectively, and the hub 3 is rotatable on the inner diameter side of the outer ring 2. I support it.

  Further, an encoder 13 is fitted and fixed to a portion of the outer peripheral surface of the inner ring 7 in the axially inner end portion that is displaced inward in the axial direction from the inner ring raceway 8b. This encoder 13 is formed by combining a support ring 14 formed of a magnetic metal plate with a substantially L-shaped cross section and formed into an annular shape as a whole, and an encoder body 16 attached to the side surface of an annular portion 15 constituting the support ring 14. . The encoder body 16 is formed in a ring shape by a permanent magnet such as a rubber magnet mixed with ferrite powder. The encoder body 16 is magnetized in the axial direction, and the direction of magnetization is alternately and equally in the circumferential direction. It is changed at intervals. Therefore, the south pole and the north pole are alternately arranged at equal intervals on the inner side surface in the axial direction, which is the detected surface of the encoder body 16.

  Further, a seal ring 17 is installed between the axially outer end opening of the outer ring 2 and the axially intermediate part outer peripheral surface of the hub body 6, and a cap 19 is attached to the axially inner end opening of the outer ring 2. Wearing. As a result, both axial end openings of the space 18 in which the rolling elements 12 and 12 and the encoder 13 are installed are closed, and the grease sealed in the space 18 leaks into the external space or exists in the external space. Foreign matter is prevented from entering the space 18.

  The cap 19 has a bottomed cylindrical cap body 20 made by injection molding of a synthetic resin, and a fitting ring formed in a circular shape with an L-shaped cross section by press molding a nonmagnetic metal plate. 21. The cap main body 20 includes a cap cylindrical portion 22 and a cap bottom portion 23 that closes an axially inner end opening of the cap cylindrical portion 22. The fitting ring 21 is fixed (molded) to the inner diameter side portion of the tip end portion of the cap cylindrical portion 22. In addition, a mounting portion 24 that bulges inward in the axial direction (having a larger axial thickness dimension) than the other portions is provided at a radially outward portion of the cap bottom 23. A through hole 25 penetrating in the axial direction is formed in a portion of the mounting portion 24 facing the detected surface of the encoder 13 (encoder main body 16) in the axial direction. And in this through-hole 25, the bottomed cylindrical sensor insertion ring 26 made from a nonmagnetic stainless steel plate is fitted. The sensor insertion ring 26 is embedded in the mounting portion 24 by insert molding at the time of injection molding of the cap body 20. Further, a mounting nut 27 having an internal thread formed on the inner peripheral surface is embedded in the portion of the mounting portion 24 that is removed from the through hole 25 by insert molding.

  A sensor unit 28 for detecting the rotational speed is supported and fixed to the cap 19. The sensor unit 28 includes a sensor 29 and a sensor holder 30. The sensor 29 includes a magnetic detecting element such as a Hall element or a magnetoresistive element provided in the detection unit, and changes an output signal in response to a change in characteristics of the detected surface of the encoder 13. The sensor holder 30 is formed by injection-molding synthetic resin, and includes an insertion portion 31 that holds the sensor 29 and an attachment flange portion 32 that is fixed to the cap 19. In such a sensor unit 28, the male thread portion of the bolt 34 inserted through the through hole formed in the mounting flange portion 32 in a state where the insertion portion 31 is inserted into the sensor insertion ring 26, the mounting nut 27. It is fixed to the cap 19 (attachment portion 24) by being screwed into the female screw portion.

  According to the rolling bearing unit 1 with the rotational speed detection device having the conventional structure having the above-described configuration, the wheel fixed to the hub 3 can be rotatably supported with respect to the suspension device supporting the outer ring 2. Further, when the encoder 13 is rotated together with the hub 3 with the rotation of the wheel, the vicinity of the detection portion of the sensor 29 facing the detection surface of the encoder 13 through the bottom plate portion 35 of the sensor insertion ring 26. The N pole and the S pole existing on the detected surface of the encoder 13 pass alternately. As a result, the direction of the magnetic flux flowing in the magnetic detection elements constituting the sensor 29 is alternately changed, and the characteristics of the magnetic detection elements are alternately changed. Since the frequency at which the characteristic of the magnetic detection element changes in this way is proportional to the rotational speed of the hub 3, the ABS and TCS can be appropriately controlled by sending the output signal of the sensor 29 to a controller (not shown). Further, in the case of the conventional structure, even if the sensor unit 28 is in a state before being assembled on an assembly line of an automobile manufacturer or the like, the space 18 in which the encoder 13 is installed can be replaced with the cap 19 (and the sensor insertion ring). 26), it is possible to effectively prevent foreign matter from adhering to the encoder 13.

However, in the case of the conventional structure as described above, the following problems may occur.
That is, in the case of the conventional structure, a pair of upper mold 36 and lower mold 37 as shown in FIG. Specifically, the synthetic resin melted in the cavity 38 having a shape that matches the outer surface shape of the cap 19 is defined in a state where the upper die 36 and the lower die 37 are in contact with each other in the axial direction. Send in. Particularly in the case of a conventional structure, synthetic resin is fed into the cavity 38 with the sensor insertion ring 26 set (insert molding is performed). Further, when performing such insert molding, the bottom plate portion 35 constituting the sensor insertion ring 26 is brought into contact with a part of the lower die 37 in order to regulate the installation position of the sensor insertion ring 26. Similarly, a part of the upper die 36 is abutted against (intruded into) the axially inner side surface (convex curved surface) of the bent portion 41 which is a continuous portion of the cylindrical portion 39 and the flange portion 40 constituting the sensor insertion ring 26. .

  When insert molding is performed as described above, the cylindrical portion 39 of the sensor insertion ring 26 may be elastically deformed (expanded) radially outward based on the pressing force of the upper mold 36 against the sensor insertion ring 26. There is. When injection molding is performed in such a state, and then the cap 19 is taken out from the cavity 38 (the pressing force by the upper die 36 is removed), the cylindrical portion 39 is elastically restored (becomes a small diameter). In addition, there is a possibility that a gap is formed on the coupling surface between the outer peripheral surface of the cylindrical portion 39 and a portion of the synthetic resin that exists around the cylindrical portion 39. When a foreign substance such as water enters the gap, the foreign substance may further move outward in the axial direction and enter the space 18 from the axial inner end of the coupling surface.

  It is generally known that a synthetic resin contracts due to a decrease in volume when cooled and solidifies. For this reason, among the synthetic resins constituting the cap body 20, it is conceivable that the gaps caused by the above-mentioned causes disappear or decrease due to the shrinkage of the portions present around the cylindrical portion 39. However, the inner diameter of the through hole 25 is usually as small as about 10 mm, and the amount of shrinkage accompanying solidification is small, so it is difficult to completely eliminate the gap.

JP 2011-80500 A

  The present invention has been invented to realize a rolling bearing unit with a rotational speed detection device that can sufficiently secure the sealing performance by a cap in view of the above-described circumstances.

The rolling bearing unit with a rotational speed detection device of the present invention is used to rotatably support a wheel for a driven wheel with respect to a suspension device such as a knuckle, and includes an outer ring, a hub, and a plurality of rolling elements. And an encoder, a cap, and a sensor unit.
Among these, the outer ring has a double row outer ring raceway on the inner peripheral surface, and does not rotate during use.
The hub has a double-row inner ring raceway on the outer peripheral surface, and a rotation-side flange for supporting a wheel on a portion of the outer peripheral surface that protrudes axially outward from the axial outer end of the outer ring. And is supported concentrically with the outer ring on the inner diameter side of the outer ring.
Each of the rolling elements is provided between the outer ring raceways and the inner ring raceways so as to be capable of rolling plurally for each row.
The encoder is formed by alternately changing the magnetic characteristics of the inner surface in the axial direction with respect to the circumferential direction, and is supported concentrically with the hub at the inner end in the axial direction of the hub.
The cap is attached to an inner end portion in the axial direction of the outer ring and closes an opening portion in the axial direction of the outer ring.
The sensor unit includes a sensor and a sensor holder.
Among these sensors, the output signal is changed in response to a change in the characteristics of the detected surface of the encoder while facing the detected surface of the encoder.
The sensor holder holds the sensor and is supported by a portion of the cap that faces the encoder in the axial direction.

Particularly in the case of the rolling bearing unit with a rotational speed detection device of the present invention, the cap has a cap body and a fitting core.
The fitting cored bar is entirely made of a magnetic material, and has a bottomed cylindrical shape including a cored bar cylindrical part and a cored bar bottom part. Further, a cored bar through-hole penetrating the cored bar bottom portion in the axial direction is formed in a portion of the cored bar bottom portion facing the encoder.
The cap body is entirely made of synthetic resin, and is coupled to the fitting core bar so as to cover the outer surface of the fitting core bar, and is formed into a bottomed cylindrical shape including a cap cylindrical portion and a cap bottom portion. ing. Also, this cap bottom is insertable part (insertion part) of said sensor holder on the inside, only the axially inward is open, and is disposed inside the metal core through hole Rutotomoni The sensor holding portion is provided in a state where the outer end portion in the axial direction faces the encoder without the fitting metal core .
Cap such as the above mentioned, in a state that opens axially outward, the metal core cylindrical portion of the fitting metal core, by being fixed fitted directly within the axially inner end of said outer ring, said outer ring It is assembled | attached to the axial direction inner end part.

According to the present invention , the sensor holder constituting the sensor unit includes an insertion portion that holds the sensor, and a mounting flange portion that is coupled and fixed to the inner end surface of the cap body at the proximal end portion of the insertion portion. And provide. Further, a nut holding portion is formed at the bottom of the cap with only the inner side in the axial direction opened.
Further, the mounting nut is arranged inside the nut holding portion by, for example, a mold.
Furthermore, in a state where the insertion portion is inserted inside the sensor holding portion, a bolt inserted through the through hole of the mounting flange portion is screwed into the mounting nut, whereby the sensor unit is attached to the cap. To fix.

When the present invention is carried out, the cored bar through hole is formed as a long hole as in the invention described in claim 2 , for example. And the said sensor holding | maintenance part and nut holding | maintenance part are provided in the state arrange | positioned inside the said core metal through-hole, respectively.
Or like the invention described in Claim 3 , the said sensor holding | maintenance part is arrange | positioned inside the said metal core through-hole. The nut holding portion is provided in a state where an intermediate portion thereof is disposed inside a second core metal through hole formed at a position different from the core metal through hole in the core metal bottom portion.

Further , when the present invention is carried out, preferably, as in the invention described in claim 4 , a recess opened axially outwardly and radially inwardly on the inner peripheral surface of the axially outer end portion of the cap cylindrical portion. Grooves are formed over the entire circumference. And in a state where the axial outer end surface of the cap cylindrical portion is in contact with the axial inner end surface of the outer ring, a portion of the outer peripheral surface of the core metal cylindrical portion that overlaps with the concave groove in the radial direction. The ring-shaped seal member is externally fitted. Then, the seal member is compressed in the axial direction between the axial inner end surface of the outer ring and the axial side surface of the concave groove.

According to the present invention configured as described above, the sealing performance by the cap can be sufficiently secured.
In other words, in the case of the present invention, the sensor holding portion provided on the cap body is formed so as to open only inward in the axial direction. For this reason, even when foreign matter such as water enters the outer end in the axial direction between the outer peripheral surface of the sensor holder (insertion portion) and the inner peripheral surface of the sensor holding portion, There is no entry into the space where the encoder is installed. That is, a gap is formed between the through hole provided in the cap body and the sensor insertion ring fitted in the through hole, which is problematic in the case of the conventional structure described above, leading to the space where the encoder is installed. It will not be done. Therefore, according to the present invention, the sealing performance by the cap can be sufficiently secured.
In the case of the present invention, the nut holding portion formed on the cap body is formed so as to be opened only inward in the axial direction. For this reason, even when foreign matter such as water enters the outer end in the axial direction between the outer peripheral surface of the mounting nut and the inner peripheral surface of the nut holding portion, this foreign matter installs the rolling elements and encoder. There is no intrusion into the space. As a result, the sealing performance by the cap can be sufficiently secured.
In the case of the present invention, the cored bar cylindrical part is directly fitted to the axially inner end part of the outer ring. For this reason, the cap cylindrical portion is deformed by use, as in the case where the core metal cylindrical portion is fitted to the inner end in the axial direction of the outer ring via the cap cylindrical portion of the cap body made of synthetic resin. There is no occurrence of a gap between the inner peripheral surface of the outer ring and the outer peripheral surface of the cap cylindrical portion. Therefore, the sealing performance by the cap can be sufficiently secured.
And like the invention described in claim 4 , in the outer peripheral surface of the cored bar cylindrical part, in the position overlapping with the concave groove formed in the axially outer end inner peripheral surface of the cap cylindrical part in the radial direction, If an annular seal member is externally fitted, it is possible to effectively prevent foreign substances such as water from entering the fitting portion between the outer peripheral surface of the cored bar cylindrical portion and the inner peripheral surface of the axially inner end of the outer ring. .

Sectional drawing which shows the rolling bearing unit with a rotational speed detection apparatus which shows the 1st example of embodiment of this invention. Similarly, the figure equivalent to the B section of Drawing 1 shown in the state where a sensor unit was omitted. Similarly, the figure which looked at the sensor holding | maintenance part and nut holding part of the cap main body from the axial direction inner side. The figure similar to FIG. 2 which shows the 2nd example of embodiment of this invention. The figure similar to FIG. 2 which shows the 3rd example. Similarly, the same figure as FIG. Sectional drawing which shows the rolling bearing unit with a rotational speed detection apparatus of the conventional structure. The A section enlarged view of FIG. 7 similarly. The fragmentary sectional view of a metal mold | die shown in order to demonstrate the manufacturing process of a cap similarly.

[First example of embodiment]
1 to 3 show a first example of an embodiment of the present invention. The feature of this example is that the structure of the cap 19a that closes the axially inner end opening of the outer ring 2 is devised. Since the configuration and operational effects of the other parts are basically the same as those of the above-described conventional structure, overlapping illustrations and explanations are omitted or simplified. The description will focus on the parts that were not explained.

  The rolling bearing unit 1a with a rotational speed detection device of this example supports a wheel that is a driven wheel rotatably with respect to a suspension device such as a knuckle and detects the rotational speed of the wheel. A hub 3 that is a rotating wheel is rotatably supported on a radially inner side of a certain outer ring 2 via a plurality of rolling elements 12 and 12.

  The hub body 6 constituting the outer ring 2 and the hub 3 is made of medium carbon steel such as S53C, and at least the surfaces of the tracks 4a, 4b, and 8a are subjected to a hardening process such as induction hardening. On the other hand, the inner ring 7 and the respective rolling elements 12 and 12 constituting the hub 3 are made of high carbon chrome bearing steel such as SUJ2, and are subjected to a hardening process by, for example, quenching. The rolling elements 12 to be used are not limited to the balls as shown in FIG. When the rolling bearing unit with a rotational speed detection device 1a of this example is used for an automobile having a heavy weight, a tapered roller can be used as the rolling element 12.

  In addition, an encoder 13a is externally fitted and fixed (press-fit) to the axially inner end (right end in FIG. 1) of the outer peripheral surface of the inner ring 7. The encoder 13a includes a support ring 14a and an encoder body 16a. Of these, the support ring 14a is formed into an annular shape with a substantially L-shaped cross section by pressing a ferritic stainless steel plate such as SUS430 or a cold rolled steel plate such as SPCC subjected to rust prevention treatment. Has been. Further, the support ring 14a is provided with a cylindrical fitting tube portion 42 and an outward direction that is bent in a radially outward direction from the axially outer end portion (left end portion in FIG. 1) of the fitting tube portion 42. It is comprised from the collar part 43 and the annular ring part 15a provided in the state bent from the axial direction inner end part of the said fitting cylinder part 42 to radial inside. The fitting tube portion 42 is provided in the outer half portion in the axial direction, and is provided on the inner half portion in the axial direction with a small diameter portion directly fitted on the inner end portion in the axial direction of the inner ring 7. And a taper portion that is inclined in a direction in which the outer diameter dimension increases as it goes to. The encoder body 16a is formed in a ring shape by a permanent magnet such as a rubber magnet or a plastic magnet mixed with a magnetic material such as ferrite powder. The encoder body 16a is magnetized in the axial direction and the direction of magnetization. These are changed alternately and at equal intervals in the circumferential direction. Then, with such an encoder main body 16a attached to the inner surface in the axial direction of the annular portion 15a, the inner surface in the axial direction (detected surface) of the encoder main body 16a is set in the axial direction of the hub main body 6. The caulking portion 10 formed at the end portion is positioned radially outward.

The cap 19a attached to the inner end in the axial direction of the outer ring 2 includes a cap body 20a made of synthetic resin, a metal fitting core 44 disposed inside the cap body 20a, and the cap body. It is comprised from the nut 27a for attachment arrange | positioned inside 20a (insert).
Of these, the cap body 20a is made by, for example, injection molding a polyamide resin mixed material in which glass fiber is appropriately added to polyamide 66 resin. If an amorphous aromatic polyamide resin (modified polyamide 6T / 6I) and a low water-absorbing aliphatic polyamide resin (polyamide 11 resin, polyamide 12 resin, polyamide 610 resin, polyamide 612 resin) are appropriately added to the polyamide resin, the water resistance becomes higher. In addition, calcium chloride resistance can be improved.
The cap body 20a made of synthetic resin thus made is coupled to the fitting core metal 44 so as to cover the entire outer surface of the fitting core metal 44, and the cap cylindrical portion 22a and the cap cylinder It is formed in the bottomed cylindrical shape provided with the cap bottom part 23a which block | closed the axial direction inner end opening part of the part 22a.

  A concave groove 45 having a rectangular cross section that is open outward in the axial direction and inward in the radial direction is formed over the entire circumference on the inner peripheral surface of the outer end portion in the axial direction of the cap cylindrical portion 22a. Further, of the axial outer end surface of the cap cylindrical portion 22a, the outer diameter side portion from the axial outer end opening of the concave groove 45 abuts against the axial inner end surface of the outer ring 2, and thus a flat surface shape. Is formed.

Further, a mounting portion 24a is provided on one part of the cap bottom 23a in the circumferential direction so as to bulge inward in the axial direction (the thickness dimension in the axial direction becomes larger) than other parts.
In addition, a sensor holding cylinder 46 corresponding to the sensor holding portion of the claims is provided in a portion of the mounting portion 24a that faces the detection surface of the encoder 13a (encoder main body 16a) in the assembled state. However, it is formed in a bottomed cylindrical shape that is opened only inward in the axial direction. The sensor holding cylinder 46 is for holding an insertion portion 31a of a sensor unit 28a, which will be described later, on the inside thereof, and is provided in a state of closing the cylindrical portion 48 and the axially outer end opening of the cylindrical portion 48. And a bottom 47. Further, the thickness dimension W ₄₇ in the axial direction of the bottom portion 47 is made smaller than the thickness dimension W ₄₈ in the radial direction of the cylindrical portion 48 (W ₄₇ <W ₄₈ ). Specifically, the thickness dimension W ₄₈ in the radial direction of the cylindrical portion 48 is set to be two to three times the thickness dimension W ₄₇ in the axial direction of the bottom portion 47 {W ₄₈ = (2-3) W ₄₇ }. . In this way, when the cap body 20a is formed by injection molding, the occurrence of sink marks due to the difference in thickness between the cylindrical portion 48 and the bottom portion 47 is prevented. The sensor holding cylinder 46 as described above is inserted in the radially outer half inside the cored bar through hole 55 of the fitting cored bar 44 described later, while the axially intermediate part is inserted therethrough, and the axially outer side of the bottom part 47 is disposed. The side surface is arranged in the state of facing the encoder 13a. In this state, a part in the circumferential direction (upper part in FIG. 1) of the outer half in the axial direction of the cylindrical part 48 constituting the sensor holding cylinder 46 is formed on the fitting cored bar 44. While being fixed to a part of the inner peripheral surface of the cored bar cylindrical part 53, a part of the cylindrical part 48 in the axial direction and a part of the cored bar through hole 55 in the circumferential direction (the upper part in FIG. 1) ).

Further, a nut holding cylinder 49 corresponding to the nut holding part in the claims is positioned inward in the axial direction at a position shifted from the sensor holding cylinder 46 inward in the radial direction of the cap bottom part 23a. It is formed in a bottomed cylindrical shape that is open only at the bottom. Specifically, the nut holding cylinder 49 is for holding the mounting nut 27a on the inside thereof, and is provided in a state in which the cylindrical portion 50 and the axially outer end opening of the cylindrical portion 50 are closed. The bottom 51 is formed. Such a nut holding cylinder 49 is disposed in a radially inner half portion inside the cored bar through-hole 55 of the fitting cored bar 44 with its axially intermediate part inserted therethrough. Also, in this state, a part of the axially intermediate part of the cylindrical part 50 constituting the nut holding cylinder 49 and a part of the circumferential direction of the cored bar through hole 55 (the lower part of FIG. 1). ).
The sensor holding tube 46 and the nut holding tube 49 are continuous only at the inner ends in the axial direction between the cylindrical portions 48 and 50. Specifically, the axial inner end of the cylindrical portion 48 of the sensor holding cylinder 46 and the axial inner end of the cylindrical portion 50 of the nut holding cylinder 49 are connected to the sensor and nut holding cylinders 46, 49. It continues by the continuous part 52 provided in the part between each other.

The fitting core bar 44 is formed into a bottomed cylindrical shape (cross-section) by pressing a cold rolled steel plate such as SPCC, SPCD, or SPCE, an austenitic stainless steel plate, an aluminum alloy plate or the like. The shape is a petri dish with a substantially U-shape. Such a fitting cored bar 44 includes a cored bar cylindrical part 53 and a cored bar bottom part 54 that closes the axially inner end opening of the cored bar cylindrical part 53.
A part of the cored bar bottom 54 in the circumferential direction, which is opposed to the surface to be detected of the encoder 13a (encoder main body 16a) in the axial direction, has an elliptical cored bar through hole 55 that is long in the radial direction. The cored bar bottom 54 is formed so as to penetrate in the axial direction. In the case of this example, the fitting mandrel 44 does not exist between the detected surface of the encoder 13a (encoder main body 16a) and the detection portion of the sensor 29a described later. For this reason, the metal material of the fitting core metal 44 may be made of a magnetic material or a non-magnetic material. If this fitting mandrel 44 is made of a cold-rolled steel sheet for deep drawing such as SPCE which is inexpensive and easy to press, it is expensive and difficult to press like austenitic stainless steel. Compared with the case of making a magnetic metal plate, the manufacturing cost can be reduced. If the fitting cored bar 44 is made of a magnetic metal plate, the cored bar bottom 54 is on the side opposite to the encoder 13a (inward in the axial direction) with respect to the sensor 29a in the assembled state. Therefore, the sensitivity of the sensor can be improved by adjusting the flow of the magnetic flux coming out of the detection surface of the encoder 13a.

  The fitting cored bar 44 having such a configuration is molded at the time of injection molding of the cap body 20a on the inner diameter side of the cap cylindrical part 22a of the cap body 20a and on the outer side in the axial direction of the cap bottom part 23a. The cap body 20a is fixed.

  Specifically, the axially inner half of the cored bar cylindrical portion 53 is fixed to the inner diameter side of the cap cylindrical portion 22a, and the axially outer half is similarly outside the axial direction of the cap cylindrical portion 22a. It protrudes outward in the axial direction from the end face. The core metal bottom portion 54 has an inner surface in the axial direction fixed to an outer surface in the axial direction of the cap bottom portion 23a. In this state, the sensor holding cylinder 46 and the nut holding cylinder 49 of the cap body 20a are inserted inside the cored bar through hole 55 in a state where the respective axial intermediate portions are arranged.

  The mounting nut 27a has a bottomed cylindrical shape in which an internal thread portion 56 is formed on the inner peripheral surface. Further, concave grooves 57a and 57b are formed over the entire circumference at two positions in the axial direction on the outer peripheral surface of the mounting nut 27a. Such a mounting nut 27 a is embedded inside the nut holding cylinder 49.

  Then, in a state where the mounting nut 27a is embedded in the cap body 20a (nut holding cylinder 49), both side surfaces in the axial direction of the recessed grooves 57a and 57b and the recessed grooves of the cap body 20a. The portions filled inside 57a and 57b engage in the axial direction, thereby preventing the relative displacement in the axial direction of the mounting nut 27a with respect to the cap body 20a. The inner end surface in the axial direction of the mounting nut 27a is located on the same virtual plane as the inner surface in the axial direction of the mounting portion 24a, and the female screw portion 56 opens to the inner surface in the axial direction of the mounting portion 24a. ing.

  In the case of this example, the mounting nut 27a has a structure that does not penetrate in the axial direction (cap nut). For this reason, it is not necessary to screw with a male screw as shown in FIG. 9 at the time of insert molding, and the workability of insert molding can be improved. On the other hand, when the mounting nut has a structure penetrating in the axial direction, insert molding is performed in a state of being screwed with a male screw (see FIG. 9) so that the resin does not enter inside the mounting nut.

  Further, the fixing method of the mounting nut 27a to the cap body 20a (nut holding cylinder 49) is not limited to insert molding, and a portion corresponding to the nut holding cylinder 49 of the cap body 20a has a bottomed cylindrical shape, A nut insertion hole in which a long locking groove is formed in the axial direction on the inner peripheral surface in advance, and a mounting nut provided with a locking protrusion that is long in the axial direction on the outer peripheral surface is used to lock these nuts. Serrated on the outer peripheral surface of a nut insertion hole formed in a bottomed cylindrical shape that is press-fitted in a state where the phase of the ridge and the locking groove is matched, or where the inner peripheral surface is not formed with a groove or the like It is also possible to press-fit a nut having a long ridge in the axial direction, and to form a groove on the inner peripheral surface of the nut insertion hole, thereby locking the nut.

  The cap 19a having the above-described configuration has a pair of molds (as shown in FIG. 9) partially having a shape that matches the inner peripheral shape of the sensor holding cylinder 46 and the nut holding cylinder 49. An apparatus comprising one mold of the upper mold 36 and the lower mold 37) and the other mold partially having a shape that matches the outer peripheral surface shape of the sensor holding cylinder 46 and the nut holding cylinder 49 is used. In addition, it can be formed by injection molding (axial draw molding) in a state where the mounting nut 27a and the fitting core metal 44 are disposed in a cavity 38 defined between the two molds.

  The cap 19a having the above-described configuration is formed on the outer peripheral surface of the cored bar cylindrical part 53 in a ring shape that overlaps with the concave groove 45 of the cap cylindrical part 22a in the radial direction. In a state where a rubber O-ring 58 having a circular cross section corresponding to a seal member is attached (externally fitted), the outer peripheral surface of the axially outer half portion of the fitting metal core 44 is arranged in the axial direction of the outer ring 2. While fitting directly to the inner peripheral surface of the end portion (metal fitting), the outer end surface in the axial direction of the cap cylindrical portion 22a is abutted against the inner end surface in the axial direction of the outer ring 2 so that the outer ring 2 is assembled. . In this assembled state, the outer surface in the axial direction of the bottom 47 of the sensor holding cylinder 46 is in close proximity to the detected surface of the encoder 13a via a predetermined axial gap (air gap). ing.

Further, the O-ring 58 is clamped in an axially compressed state between the axial side surface of the concave groove 45 and the axial inner end surface of the outer ring 2 in the assembled state as described above. Is done. For this reason, even when foreign matter such as water enters from the abutting portion between the axial outer end surface of the cap cylindrical portion 22a and the axial inner end surface of the outer ring 2, such foreign matter is caused by the O-ring 58. Thus, it is possible to effectively prevent the metal fitting portion between the outer peripheral surface of the cored bar cylindrical portion 53 and the inner peripheral surface of the outer ring 2 in the axial direction from being reached.
In the case of this example, the end portion of the coupling surface between the cap main body 20a and the fitting cored bar 44 (the boundary surface between the members 20a and 44) of the cap 19a is not exposed to the outside. Further, the only end portion of this coupling surface (the portion corresponding to the radially inner end portion of the axial side surface of the groove 45) is sealed by the O-ring 58. For this reason, even when a gap occurs in the coupling surface, the foreign matter can be effectively prevented from entering the space 18 through the gap.

In the case of this example, the sensor unit 28a for detecting the rotational speed is supported and fixed to the cap 19a having the above-described configuration. The sensor unit 28a includes a sensor 29a, and a sensor holder 30a. Among them, the sensor 29a has a magnetic detecting element such as a Hall element or a magnetoresistive element installed in the detecting section, and changes the output signal in response to a change in the characteristics of the detected surface of the encoder 13a. The sensor holder 30a is intended that the synthetic resin such as polyamide resin formed by injection molding, comprising the interpolation join the club 31a, and a flange portion 32a INSTALLATION. Of these, the insertion portion 31a holds the sensor 29a at the distal end portion (axially outer end portion) and has an outer diameter dimension that is the same as or slightly smaller than the inner diameter dimension of the sensor holding cylinder 46.
The mounting flange portion 32a is for fixing the sensor holder 30a (sensor 29a) to the cap 19a, and is provided at the base end portion of the insertion portion 31a. In such a sensor unit 28a, the male thread of the bolt 34 inserted through the sleeve 60 fitted in the through hole 59 formed in the mounting flange portion 32a in a state where the insertion portion 31a is directly inserted into the sensor holding cylinder 46. The portion 33 is fixed to the cap 19a (mounting portion 24a) by screwing into the female thread portion 56 of the mounting nut 27a.

  In addition, in a state where the sensor unit 28a is supported and fixed to the cap 19a, the distal end surface (axial outer end surface) of the insertion portion 31a and the axial inner side surface of the bottom portion 47 of the sensor holding cylinder 46 are in the axial direction. It will be in the state of facing or abutting through a minute gap. In such a state, the sensor 29a (the detecting portion thereof) held at the distal end portion of the insertion portion 31a faces the detection surface of the encoder 13a via the bottom portion 47.

  Also in this example having the above-described configuration, the wheel fixed to the hub 3 can be rotatably supported with respect to the suspension device that supports the outer ring 2. When the encoder 13a is rotated together with the hub 3 along with the rotation of the wheels, the vicinity of the detection portion of the sensor 29a facing the detection surface of the encoder 13a via the bottom portion 47 of the encoder 13a. The N pole and S pole existing on the detection surface pass alternately. As a result, the direction of the magnetic flux flowing in the magnetic detection element constituting the sensor 29a is alternately changed, and the characteristics of the magnetic detection element are alternately changed. Since the frequency at which the characteristics of the magnetic detection element change in this way is proportional to the rotational speed of the hub 3, the ABS and TCS can be appropriately controlled by sending the output signal of the sensor 29a to a controller (not shown).

In particular, in the case of this example, the sealing performance by the cap 19a can be sufficiently secured.
That is, in the case of this example, the sensor holding cylinder 46 provided on the cap body 20a is formed in a bottomed cylindrical shape that is opened only inward in the axial direction. For this reason, even if foreign matter such as water enters the axially outer end portion between the outer peripheral surface of the insertion portion 31a and the inner peripheral surface of the sensor holding cylinder 46, the foreign matter is transferred to the rolling elements 12, 12 and the space 18 in which the encoder 13a is installed does not enter. That is, between the through hole 25 provided in the cap main body 20 (see FIG. 7) and the sensor insertion ring 26 fitted in the through hole 25, which is problematic in the case of the conventional structure described above, A gap that leads to the space 18 is not formed. Therefore, according to the rolling bearing unit 1a with the rotational speed detection device of this example, the sealing performance by the cap 19a can be sufficiently ensured.

In the case of this example, the nut holding cylinder 49 formed on the cap body 20a is formed in a bottomed cylindrical shape opened only in the axial direction. For this reason, even when foreign matter such as water enters the outer end in the axial direction between the outer peripheral surface of the mounting nut 27a and the inner peripheral surface of the nut holding cylinder 49, the foreign matter is retained in the space 18. There is no intrusion. As a result, the sealing performance by the cap 19a can be sufficiently secured.
In the case of this example, the sensor 29a faces the detected surface of the encoder 13a without the fitting cored bar 44 interposed therebetween. For this reason, even if this fitting core 44 is made of any metal material made of magnetic material or non-magnetic metal, press processing or surface processing (roughening processing) for improving adhesiveness with resin. After the above, an annealing process for removing magnetism becomes unnecessary. As a result, the manufacturing cost can be reduced.

In the case of this example, the outer peripheral surface of the cored bar cylindrical portion 53 of the fitting cored bar 44 is directly fitted to the inner peripheral surface of the inner end portion in the axial direction of the outer ring 2. For this reason, even when the use is continued, it is possible to prevent a gap or the like from being generated in the fitting portion.
That is, like the conventional structure described above, the fitting ring 21 (see FIG. 7) is fitted to the inner peripheral surface of the inner end portion in the axial direction of the outer ring 2 through the cap cylindrical portion 22 of the cap body 20 made of synthetic resin. In the case of a structure to be combined, there is a possibility that a deformation such as sag occurs in the cap cylindrical portion 22 by use, and a gap may be formed between the outer ring 2 and the fitting portion of the cap cylindrical portion 22. On the other hand, in the case of this example, the metal cored bar cylindrical portion 53 is directly metal-fitted to the outer ring 2. For this reason, it can prevent that the clearance gap based on deformation | transformation of a sag etc. arises in this cored bar cylindrical part 53. FIG. Therefore, according to this example, the sealing performance by the cap 19a can be sufficiently ensured. It is also possible to easily ensure a constant gap in the axial direction between the sensor 29a and the encoder 13a over a long period of time.

Further, in the case of this example, the engagement core metal 44 and the cap body 20a are separated and relatively rotated by the engagement of the peripheral portion of the core metal through hole 55 with the sensor holding cylinder 46 and the nut holding cylinder 49. Can be prevented (rotation prevention). For this reason, it is not necessary to separately provide means such as a notch, a bent portion, or adhesion for preventing separation and relative rotation between the fitting core metal 44 and the cap body 20a. As a result, the manufacturing cost can be reduced.
Furthermore, in the case of this example, the O-ring 58 is externally fitted to a portion of the outer peripheral surface of the cored bar cylindrical portion 53 that overlaps the concave groove 45 of the cap cylindrical portion 22a in the radial direction. For this reason, it penetrate | invades from the clearance gap which arose between the axial direction inner end surface of the said outer ring | wheel 2 and the axial direction outer end surface of the said cap cylindrical part 22a, and the joint surface of the said cap main body 20a and the said fitting metal core 44. It is possible to effectively prevent foreign substances such as water from entering the fitting portion between the outer peripheral surface of the cored bar cylindrical portion 53 and the inner peripheral surface of the inner end portion in the axial direction of the outer ring 2.

[Second Example of Embodiment]
Figure 4 shows a second example of the embodiment of the present invention.
In the case of the rolling bearing unit with the rotational speed detection device of this example, the fitting cored bar 44a includes a cored bar cylindrical part 53a, a cored bar bottom part 54a for closing the axially inner end opening of the cored bar cylindrical part 53a, a flange The unit 61 is configured. The flange portion 61 is formed in a state in which it is bent at a right angle outwardly in the radial direction from the axial inner end of the cored bar cylindrical portion 53a and its intermediate portion is folded back 180 degrees radially inward. The radially inner end of the flange portion 61 is continuous with the radially outer end of the cored bar bottom portion 54a. In the case of this example, the axially inner side surfaces of the flange portion 61 and the cored bar bottom portion 54a are located on the same plane.

In the case of this example as well, a part of the cored bar bottom 54a in the circumferential direction has a long oval shape in the radial direction at a portion facing the detection surface of the encoder 13a (encoder main body 16a) in the axial direction. A cored bar through hole 55 is formed. As in this example, in the case where the flange portion 61 is provided on the fitting core metal 44a, the core metal through hole 55 can be formed stably and easily.
That is, when the structure in which the cored bar cylindrical portion 53a of the fitting cored bar 44a is directly fitted to the inner peripheral surface of the axially inner end of the outer ring 2 as in this example is adopted, the cored bar cylindrical part 53a is The outer ring 2 needs to be formed concentrically with high accuracy with respect to the inner peripheral surface of the inner end portion in the axial direction. For this reason, the cored bar through hole 55 is formed in the cored bar bottom 54a after the fitting cored bar 44a is formed in a bottomed cylindrical shape (petriform). However, when the cored bar through hole 55 is formed near the cored bar cylindrical part 53a in the cored bar bottom part 54a, the fitting cored bar 44 ( If the flange portion 61 is not formed in FIG. 1), the core metal cylindrical portion 53 of the fitting core metal 44 of the die (not shown) used when forming the core metal through hole 55 is used. However, there is a possibility that the portion located radially outward cannot be stably supported. On the other hand, in the case of the structure in which the fitting cored bar 44a is provided with the flange portion 61 as in this example, the die is positioned radially outward from the cored bar cylindrical part 53a of the fitting cored bar 44a. The cored bar through hole 55 can be formed in a state in which the portion to be supported is stably supported by the axial inner side surface of the flange portion 61.
Further, the flange portion 61 can prevent the fitting core metal 44a and the cap body 20a from coming off (preventing separation) by engaging with the cap body 20a in the axial direction. Other configurations and operations / effects are the same as those in the first example of the embodiment described above.

[Third example of embodiment]
FIG. 5 shows a third example of the embodiment of the present invention.
In the case of the rolling bearing unit with the rotational speed detection device of this example, a round circle is formed on a portion of the cored bar bottom 54b of the fitting cored bar 44b that faces the detected surface of the encoder 13a (encoder body 16a) in the axial direction. A cored bar through-hole 55a having a shape is formed.
Further, a second circular metal core through hole 62 having a circular shape is formed at a position radially inward of the metal core through hole 55a so as not to be continuous with the metal core through hole 55a.

Then, the sensor holding cylinder 46a is engaged with the peripheral portion of the cored bar through hole 55a of the cored bar bottom part 54b over the entire circumference in the axial direction, and the axially outer end surface (bottom part 47). Of the encoder 13a (encoder main body 16a) is provided in close proximity to the surface to be detected.
Further, the nut holding tube 49a is put around the entire circumference in the axial direction and engaged with the peripheral portion of the second cored bar through hole 62 of the cored bar bottom part 54b, and the axially outer end surface thereof. (The outer surface in the axial direction of the bottom 51) is provided in a state of being arranged at substantially the same position as the outer end surface in the axial direction of the sensor holding cylinder 46a.
The sensor holding cylinder 46a and the nut holding cylinder 49a are part of the cap bottom 23b, and the sensor and nut holding cylinders 46a, 49a of the cored bar bottom 54b as described above. The part between them is continuous by continuous parts 52a that respectively cover both sides in the axial direction.

In the case of this example having the above-described configuration, the peripheral portion of the core metal through hole 55a and the sensor holding tube 46a are engaged, and the peripheral portion of the second core metal through hole 62 and the nut holding tube 49a. By this engagement, separation of the fitting core metal 44b and the cap body 20b and prevention of relative rotation (rotation prevention) can be achieved. For this reason, it is not necessary to separately provide means such as a notch, a bent portion, or adhesion for preventing separation and relative rotation between the fitting core metal 44b and the cap body 20b. As a result, the manufacturing cost can be reduced.
In the case of this example, the shape of the cored bar through hole 55a and the second cored bar through hole 62 are both formed in a simple regular circle. For this reason, the metal mold | die at the time of performing a press work (drilling process) can be made into a simple shape, and reduction of manufacturing cost can be aimed at.
Further, in the case of this example, the cored bar bottom portion 54b is opposite to the encoder 13a (inner side in the axial direction) with respect to the sensor 29a (see FIG. 1). It exists all around. For this reason, if the fitting metal core 44b is made of a magnetic metal plate, the flow of the magnetic flux coming out of the detection surface of the encoder 13a can be adjusted, and the sensitivity of the sensor can be further improved. Other configurations and operations / effects are the same as those in the first example of the embodiment described above.

The present invention can also be implemented by appropriately combining the structures of the examples of the above-described embodiments.
The shape or arrangement of the sensor holding portion (sensor holding cylinder) is not limited to the case of each example of the above-described embodiments. In short, it is possible to adopt various structures in which only the inner side in the axial direction is open and the outer end surface in the axial direction faces the encoder without using a fitting cored bar.
Furthermore, the material of the fitting Goshinkin may be either a magnetic material made of a non-magnetic material. As described above, if it is made of cold-rolled steel sheets for deep drawing such as SPCE, which is inexpensive and easy to press, not only can the manufacturing cost be reduced, but also the degree of freedom in design related to the shape of the fitting core bar. It can also be raised.

DESCRIPTION OF SYMBOLS 1, 1a Rolling bearing unit with a rotational speed detector 2 Outer ring 3 Hub 4a, 4b Outer ring raceway 5 Stationary side flange 6 Hub body 7 Inner ring 8a, 8b Inner ring raceway 9 Small diameter step part 10 Caulking part 11 Rotation side flange 12 Rolling element 13, 13a Encoder 14, 14a Support ring 15, 15a Ring portion 16, 16a Encoder body 17 Seal ring 18 Space 19, 19a Cap 20, 20a, 20b Cap body 21 Fitting ring 22, 22a Cap cylindrical portion 23, 23a, 23b Cap Bottom portion 24, 24a Mounting portion 25 Through hole 26 Sensor insertion ring 27, 27a Mounting nut 28, 28a Sensor unit 29, 29a Sensor 30, 30a Sensor holder 31, 31a Insertion portion 32, 32a Mounting flange portion 33 Male thread portion 34 Bolt 35 Bottom plate 36 Mold 37 Lower mold 38 Cavity 39 Cylindrical part 40 Eaves part 41 Bent part 42 Fitting cylinder part 43 Outward eaves part 44, 44a, 44b Fitting cored bar 45 Concave groove 46, 46a Sensor holding cylinder 47 Bottom part 48 Cylindrical part 49, 49a Nut holding cylinder 50 Cylindrical part 51 Bottom part 52, 52a Continuous part 53, 53a Core metal cylindrical part 54, 54a, 54b Core metal bottom part 55, 55a Core metal through hole 56 Female thread part 57a, 57b Concave groove 58 O-ring 59 Through hole 60 Sleeve 61 Flange 62 Second metal core through hole

Claims (4)

An outer ring having a double-row outer ring raceway on the inner peripheral surface and not rotating during use;
The outer ring has a double-row inner ring raceway and is supported concentrically with the outer ring on the inner diameter side of the outer ring, and on the part of the outer circumferential surface that protrudes outward in the axial direction from the axial outer end of the outer ring. A hub provided with a rotation side flange for supporting the wheel;
Between the both outer ring raceways and the both inner ring raceways, a plurality of rolling elements provided so as to be freely rollable for each row,
An annular encoder that is formed by alternately changing the magnetic properties of the inner surface in the axial direction with respect to the circumferential direction, and is supported concentrically with the hub at the inner end in the axial direction of the hub;
A cap that is attached to the axially inner end of the outer ring and closes the axially inner end opening of the outer ring;
A sensor that changes an output signal in response to a change in the characteristics of the detected surface of the encoder in a state of being opposed to the detected surface of the encoder, and holding the sensor, A sensor unit comprising a sensor holder supported on the opposing part;
A rolling bearing unit with a rotational speed detection device comprising:
The cap has a cap body and a fitting core,
The fitting metal core is entirely made of a magnetic material and has a bottomed cylindrical shape composed of a metal core cylinder part and a metal core bottom part, and a part of the metal core bottom part facing the encoder is disposed on the core metal part. A cored bar through-hole penetrating the bottom of the metal in the axial direction is formed,
The cap body is entirely made of synthetic resin, and is coupled to the fitting core bar so as to cover the outer surface of the fitting core bar, and has a bottomed cylindrical shape including a cap cylindrical part and a cap bottom part. the bottom is insertable part of the sensor holder on the inside, only the axially inward is opened, and the is disposed inside the metal core through hole Rutotomoni, its axially outer end portion the a sensor holding portion which is the encoder and the counter without passing through the fitting metal core, with only axially inwardly is opened, and a nut holding portion mounting nut is located is provided on its inner side cage,
Before SL cap, while opening axially outward, the metal core cylindrical portion of the fitting metal core, by being fixed fitted in direct axially inner end portion of the outer ring, the axial direction of the outer ring It is assembled at the inner end ,
The sensor holder includes an insertion portion that holds the sensor, and a mounting flange portion that is provided at a proximal end portion of the insertion portion and is coupled and fixed to an axially inner side surface of the cap body.
The sensor unit is attached to the cap by screwing a bolt inserted through the through hole of the mounting flange portion into the mounting nut in a state where the insertion portion is inserted inside the sensor holding portion. Fixed,
Rolling bearing unit with rotation speed detector. The cored bar through hole is a long hole,
The rolling bearing unit with a rotational speed detection device according to claim 1 , wherein the sensor holding part and the nut holding part are provided in a state of being arranged inside the cored bar through hole. The sensor holding part is disposed inside the cored bar through hole,
The nut holding portion, wherein the said metal core through-hole of the metal core bottom is provided in a state of being arranged inside the second metal core through-hole formed in different positions, in claim 1 The rolling bearing unit with the described rotational speed detector. On the inner peripheral surface of the axial outer end of the cap cylindrical portion, a concave groove that is opened outward in the axial direction and radially inward is formed over the entire circumference.
In the state where the axial outer end surface of the cap cylindrical portion is in contact with the axial inner end surface of the outer ring, on the outer circumferential surface of the core metal cylindrical portion, The seal member is externally fitted, and the seal member is clamped in the axial direction between the axial inner end surface of the outer ring and the axial side surface of the concave groove . A rolling bearing unit with a rotational speed detection device according to item 1 .

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