JP2010043889A - Rotation detection sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation detection sensor that is fixed to a sensor fixation member by a simple fixation structure so that a sensor unit is positioned, and has improved waterproofness and vibration resistance. <P>SOLUTION: The rotation detection sensor is fixed to the sensor fixation member 7 mounted to a bearing for wheels and detects rotation of a rotary ring in the bearing for wheels. A sensor unit B includes: a magnetic sensor element 1 for detecting a body to be detected in the rotary ring; a cable 10 for taking out the output signal to the outside; and a substrate 11 to which one end of the sensor element 1 and one end of the cable 10 are mounted while having a conductive section 3 for connecting an electrode section 2 of the sensor element 1 and a conductor 4 of the cable 10. Recesses 11a or projections at least at one place or more provided on the substrate 11 are fitted to projections 7d or recesses provided in the sensor fixation member 7, thus fixing the sensor unit B to the sensor fixation member 7. By covering the sensor unit B, a molding section 8 obtained by forming a molding material made of thermoplastic elastomer or a rubber material is provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotation detection sensor used as, for example, an automobile ABS sensor.

  The ABS sensor (axle rotation sensor) used by mounting on a hub bearing of an automobile is provided with a magnet or a metal body on a rotating wheel of the hub bearing, and a magnetic sensor such as a magnetic pickup, a hall sensor, or an MR sensor is arranged opposite to the magnet. It has been configured. ABS sensors are required to have mechanical strength, waterproofness, weather resistance, chemical resistance, and the like. Therefore, it is used as a sensor unit structure by overmolding the sensor component with resin or the like.

As a method for overmolding a sensor component, for example, Patent Document 1 proposes a method in which a sensor component is fixed in advance to a sensor fixing holder and is overmolded with a resin.
JP 2000-88984 A

The sensor unit structure for an ABS sensor by the conventional overmolding method has the following problems.
-Since the molding material is resin, the adhesiveness between the built-in product such as sensor parts and sensor fixing holder and the molding material cannot be expected.
-Due to the self-heating of sensor parts, which are electronic parts, and changes in the environmental temperature, there is a risk of a gap between the built-in product and the mold material, resulting in a problem with waterproofness.
-Even when an external force is applied to the sensor unit structure and plastic deformation occurs in the mold material, there is a problem in waterproofness because a gap is formed between the built-in product and the mold material.
-Since the molding material made of resin has low deformation capacity, when an external force is applied to the sensor unit structure, the built-in product may be damaged or deformed by the external force acting directly on the built-in product.
・ Since the mold material made of resin has poor vibration absorption, there is a problem with durability against external vibration.
-If an external force is applied that causes the signal cable section that is a signal transmission path from the sensor unit structure to the outside to bend, the external force may be transmitted to the sensor device inside the sensor unit structure, resulting in failure.
A conventional mold by injection molding requires a nozzle that allows molten resin to flow in, a runner that guides the molten resin to a hollow portion that becomes a molded product, and an inlet (gate) to the hollow portion. In order to increase the yield by smoothing the flow of the molten resin through these, the number of manufactured parts at one time is suitably from several to about ten and the number of molded parts at one time is limited.

  As a countermeasure for solving such a problem, a sensor unit includes a sensor element, a cable for taking out an output signal thereof, and a substrate having a conductive portion that electrically connects an electrode portion of the sensor element and a core wire of the cable. The sensor unit is fixed to the sensor fixing member with the substrate, and a molding part formed by molding a thermoplastic elastomer or rubber material is provided around the sensor unit to maintain waterproofness and earthquake resistance. It is conceivable to manufacture an inexpensive rotation detection sensor.

  However, in the above configuration in which the sensor unit is fixed to the sensor fixing member with the substrate, for example, if a pin is used as a means for fixing the substrate to the sensor fixing member, it is necessary to prevent the pin from coming off, and the substrate fixing structure is It becomes complicated. In addition, as another means for fixing the substrate, for example, it is possible to form two sandwich pieces integrally with the sensor fixing member and sandwich the substrate from above and below with these sandwich pieces, but this makes it difficult to position the substrate. Become. In this case, another component member is required for positioning the substrate, which again complicates the substrate fixing structure.

  An object of the present invention is to provide a rotation detection sensor that can fix a sensor unit to a sensor fixing member with a simple fixing structure so that the sensor unit can be positioned, and is excellent in waterproofness and vibration resistance.

  The rotation detection sensor according to the present invention is a rotation detection sensor which is fixed to a sensor fixing member attached to a wheel bearing and detects the rotation of a rotating wheel of the wheel bearing, and detects a detection object provided on the rotating wheel. A magnetic sensor element, a cable for taking out an output signal of the sensor element to the outside, the sensor element and one end of the cable are attached, and the electrode part of the sensor element and the core of the cable are electrically connected A sensor unit is configured with a substrate having a conductive portion connected to the substrate, and at least one recess or projection provided on the substrate is fitted to the projection or recess provided on the sensor fixing member, The sensor unit is fixed to the sensor fixing member, the sensor unit is covered, and a molding material made of a thermoplastic elastomer or rubber material is molded. Characterized in that a Rudingu portion.

According to the configuration of the present invention, the following effects can be obtained.
・ Since the sensor unit consisting of sensor parts such as sensor elements, cables, and substrates is molded with a mold material made of elastic thermoplastic elastomer or rubber material, when vibration or external force is applied to the rotation detection sensor, Since the external force is absorbed by the molding material, the influence on the sensor component can be reduced and the sensor component can be protected.
-Since the mold material is an elastic thermoplastic elastomer or rubber material, the sensor component and the mold material may experience different thermal expansion and contraction due to changes in environmental temperature and self-heating of the sensor component, which is an electronic component. However, the difference can be absorbed by the elasticity of the molding material, so that a gap is not generated between the sensor component and the molding material, and the waterproof property can be maintained.
In particular, since the substrate, which is a component of the sensor unit, is fixed to the sensor fixing member by fitting at least two or more concave portions provided on the substrate to the convex portions provided on the sensor fixing member, simple fixing With the structure, the sensor unit can be positioned and fixed to the sensor fixing member.

When the mold material is a rubber material, the molding can be performed using a mold. In that case, the mold consists of an upper mold and a lower mold, and the sensor unit and the rubber material are put between the upper mold and the lower mold, and pressure is applied between both molds while heating the upper mold and the lower mold. Thus, the molding part may be compression molded.
If molding of the molding part is compression molding using a mold, a large number of rotation detection sensors can be manufactured by one molding, and the cost can be reduced. Further, if the mold is composed of an upper mold and a lower mold, the sensor unit can be easily positioned and an appropriate pressure can be applied to the molding material. Note that a mold by injection molding requires a nozzle that allows molten resin to flow in, a runner that guides the molten resin to a hollow portion that becomes a molded product, and an inlet (gate) to the hollow portion. In order to increase the yield by smoothing the flow of the molten resin passing through these, the number of manufactured parts at one time is appropriate from several to about ten, and the number of molded parts at one time is limited. In contrast, molding by compression molding can produce a large amount of rotation detection sensor by one molding.

When the molding material is a thermoplastic elastomer, the molding can be injection molding using a mold. In that case, the molding unit is injection-molded by placing a sensor unit in the mold and injecting a thermoplastic elastomer into the mold.
Even when the mold material is a rubber material, the molding may be injection molding using a mold. In that case, the molding unit is injection-molded by placing a sensor unit in the mold and injecting a rubber material into the mold.
If the molding part is molded by injection molding, manufacturing is easy and productivity is excellent.

Further, when the mold material is a rubber material, the molding is performed using a mold composed of an upper mold and a lower mold, and the sensor unit and the rubber material are preliminarily attached to either the upper mold or the lower mold. And the molding part may be molded by injection molding a rubber material from the other mold.
When the molding part is molded in this way, in addition to the effects of molding the molding part by the injection molding alone, a sensor unit and a rubber material are put in advance in either the upper mold or the lower mold. As a result, the operational effect that the positioning of the sensor unit is facilitated can be obtained.

  As the sensor element, a Hall element, a magnetoresistive effect element (MR element), a giant magnetoresistive effect element (GMR element), a tunnel magnetoresistive element (TMR element), or a coil can be used. Whichever is used, a good rotation detection sensor is obtained.

The sensor fixing member may be attached to a fixed wheel of a wheel bearing or a peripheral member thereof.
When the sensor fixing member is attached to the fixed wheel of the wheel bearing or its peripheral member, it is not necessary to provide another member for attaching the rotation detection sensor, and the configuration is simplified.

The sensor fixing member may also serve as a cover that covers an end surface of the wheel bearing.
Also in this case, it is not necessary to provide a separate member for attaching the rotation detection sensor, and the configuration is simplified.

  The rotation detection sensor according to the present invention is a rotation detection sensor which is fixed to a sensor fixing member attached to a wheel bearing and detects the rotation of a rotating wheel of the wheel bearing, and detects a detection object provided on the rotating wheel. A magnetic sensor element, a cable for taking out an output signal of the sensor element to the outside, the sensor element and one end of the cable are attached, and the electrode part of the sensor element and the core of the cable are electrically connected A sensor unit is configured with a substrate having a conductive portion connected to the substrate, and at least one recess or projection provided on the substrate is fitted to the projection or recess provided on the sensor fixing member, The sensor unit is fixed to the sensor fixing member, the sensor unit is covered, and a molding material made of a thermoplastic elastomer or rubber material is molded. Because having a Rudingu part, by a simple fixing structure can be positioned securing the sensor unit to the sensor fixing member, it is assumed that excellent waterproof and vibration resistance.

  An embodiment of the present invention will be described with reference to FIGS. In this rotation detection sensor A, a sensor unit B composed of a plurality of sensor components is fixed to a sensor fixing member 7 and a molding portion 8 is provided so as to cover the sensor unit B. This rotation detection sensor A is used in combination with an object to be detected such as a magnetic encoder 45.

  The sensor unit B includes a magnetic sensor element 1, a cable 10 for taking out an output signal of the sensor element 1, and a substrate 11 to which the sensor element 1 and one end of the cable 10 are attached. The substrate 11 is obtained by forming the conductive portion 3 (FIG. 2) on the surface of an insulating substrate made of resin or the like by printed wiring or the like. The sensor element 1 is, for example, a Hall element, a magnetoresistive effect element (MR element), a giant magnetoresistive effect element (GMR element), a tunnel magnetoresistive element (TMR element), a coil, or another magnetic sensor element. Consists of. In the case of this embodiment, the cable 10 has two cable core wires 4. Each cable core wire 4 is covered with an insulating coating 5 in an electrically insulated state, and each insulating coating 5 is covered with a cable cover 6. It is supposed to be.

  The sensor element 1 has a pair of electrode portions 2 and 2, each electrode portion 2 is electrically connected to a pair of conductive portions 3 and 3 of the substrate 11, and each cable core wire 4 of the cable 10 is also the above-described one. It is electrically connected to the pair of conductive parts 3 and 3. The conductive part 3 is made of a metal having good electrical conductivity such as copper foil. That is, the electrode part 2 of the sensor element 1 and the core wire 4 of the cable 10 are electrically connected via the conductive part 3 of the substrate 11. The conductive portion 3 is attached to the front surface side (FIG. 3) of the substrate 11, and the sensor element 1 is attached to the back surface side (FIG. 3) of the substrate 11. The electrode portion 2 of the sensor element 1 is It extends through the outside of the substrate 11 from the back side to the front side. Although not shown in FIG. 2, as shown in FIG. 4, the surface of the substrate 11 is further electrically connected to the pair of conductive portions 3 and 3 for noise prevention. The capacitor 12 is mounted. Here, since the capacitor 12 is a surface mount type, the sensor unit B can be configured compactly. It is desirable to process both the front and back surfaces of the substrate 11 into a rough surface in order to improve the adhesiveness with the molding material to be the molding portion 8. The electrode part 2 and the conductive part 3 are electrically connected by pressure bonding, soldering, thermocompression bonding, or other joining methods. The cable core 4 and the conductive portion 3 are electrically connected by crimping, soldering, or other joining methods.

  The sensor fixing member 7 also serves as a cover for covering the end face of the wheel bearing (see FIGS. 12 and 13), and is an annular metal product centered on the central axis of the wheel bearing. The sensor fixing member 7 includes a stepped cylindrical portion 7a having a large diameter portion 7aa and a small diameter portion 7ab, and a flange portion 7b extending from the edge of the small diameter portion 7ab of the cylindrical portion 7a toward the inner diameter side. As shown in FIG. 2, the sensor unit B is fixed to the sensor fixing member 7 by fixing the substrate 11 to the flange portion 7 b of the sensor fixing member 7. An opening 7 c is formed in the flange portion 7 b, and the sensor element 1 protrudes through the opening 7 c to the side opposite to the fixed surface of the substrate 11.

  The substrate 11 is fixed to the sensor fixing member 7 by fitting at least two or more concave portions 11 a provided on the substrate 11 to the convex portions 7 d provided on the sensor fixing member 7. Specifically, the recess 11 a of the substrate 11 is formed by cutting out both ends of the sensor fixing member 7 facing the circumferential direction. The convex portion 7 d of the sensor fixing member 7 is formed by cutting and raising the edge of the opening portion 7 c facing the circumferential direction to the fixing surface side of the substrate 11. Thus, by fitting the concave portion 11 a provided on the substrate 11 to the convex portion 7 d provided on the sensor fixing member 7, the substrate 11 can be positioned and fixed to the sensor fixing member 7 with a simple fixing structure. In this case, since the material of the substrate 11 is softer than the sensor fixing member 7 which is a metal product, the concave portion 11a of the substrate 11 bites into the convex portion 7d of the sensor fixing member 7, and the fixing is ensured. Can do. As a result, the sensor unit B can be reliably positioned and fixed to the sensor fixing member 7 with a simple fixing structure. Further, since the above-described fitting can be performed only by pressing the concave portion 11a of the substrate 11 into the convex portion 7d of the sensor fixing member 7, the assemblability is facilitated.

  Instead of providing the substrate 11 with the concave portion 11a and the sensor fixing member 7 with the convex portion 7d, the substrate 11 is provided with the convex portion and the sensor fixing member 7 with the concave portion, and these convex portions and the concave portion are fitted together. The substrate 11 may be fixed to the sensor fixing member 7.

  The cable 10 drawn from the molding part 8 is wired on the flange part 7b of the sensor fixing member 7 in the circumferential direction. As shown in FIG. 1, a combination of three cable support portions 14, 15, and 16 is disposed in the flange portion 7 b of the sensor fixing member 7 at the disposition portion of the molding portion 8 and at a position away from the molding portion 8 in the circumferential direction. A cable support unit set 13 is provided. As shown in FIG. 1, the first and second cable support portions 14 and 15 are support surfaces formed in a circular arc shape that opens toward the opposite side to the direction in which the cylindrical portion 7 a of the sensor fixing member 7 projects. The cable 10 supports the half of the peripheral surface of the portion close to the molding portion 8 in the cable 10. The third cable support portion 16 has a support surface formed in a circular arc shape that opens in a direction opposite to the first and second cable support portions 14 and 15, and the first cable support portion 16 in the cable 10. And the peripheral surface half part on the opposite side to the said peripheral surface half part of the part away from the molding part 8 in the circumferential direction rather than the part supported by the 2nd cable support parts 14 and 15 is supported.

  Here, the cable support portions 14, 15, 16 are integrally formed with the sensor fixing member 7 by press-molding the flange portion 7 b of the sensor fixing member 7 that is a plate material. In the wiring portion of the cable 10 in the flange portion 7b of the sensor fixing member 7, a notch portion 17 formed by cutting out the inner diameter side of the flange portion 7b is formed between the cable support portions 14, 15, and 16. Thereby, after fixing the board | substrate 11 to the sensor fixing member 7, the cable 10 can be easily supported by each cable support part 14,15,16 from the said notch part 17. FIG.

  The molding material used for the mold of the sensor unit B is made of a material having rubber elasticity, and a rubber material or a thermoplastic elastomer is suitable. As the rubber material, nitrile rubber or fluororubber is desirable. These are excellent in heat resistance, low temperature characteristics, and oil resistance. Rubber materials other than the above may be used. As the thermoplastic elastomer, vinyl chloride, ester and amide are desirable. These are excellent in heat resistance and oil resistance.

  When the mold material is a rubber material, the molding of the mold material can be compression molding using a mold. For example, as shown in FIG. 5A, the compression molding using a mold is performed between a sensor unit B, a sensor fixing member 7 (not shown), and a mold material 22 between an upper mold 20 and a lower mold 21 which are molds. Then, as shown in FIG. 5B, the upper mold 20 and the lower mold 21 are heated and pressure is applied between both molds. Since the substrate 11 is fixed to the sensor fixing member 7, the position of the sensor unit B does not move due to the internal pressure in the molds 20 and 21 during compression molding, and the sensor unit B can be easily positioned. Further, when the mold is composed of the upper mold 20 and the lower mold 21, the positioning of the sensor unit B is easy, and an appropriate pressure can be applied to the molding material. Furthermore, if molding of the molding part 8 is compression molding using a mold, a large amount of rotation detection sensor A can be manufactured by one molding, and the cost can be reduced.

  When the molding material is a thermoplastic elastomer, the molding of the molding material is preferably injection molding using a mold. In injection molding using a mold, for example, as shown in FIG. 6A, a sensor unit B and a sensor fixing member 7 (not shown) are placed in molds 20 and 21 that can be divided. By injecting the molding material 22 into the molds 20 and 21 through the molding material injection hole 23, the molding material 22 is molded as shown in FIG. In FIG. 2A, the sensor unit B is fixed at a predetermined position by a sensor fixing member 7 (not shown). When the mold material is a rubber material, it can be similarly molded by injection molding. This injection molding is easy to manufacture and has excellent productivity.

  When the molding material is a rubber material, the molding material may be molded by the method shown in FIG. That is, a mold composed of an upper mold 20 and a lower mold 21 is used, and a sensor unit B is previously placed in either the upper mold or the lower mold (the lower mold 21 in the illustrated example) as shown in FIG. Then, the sensor fixing member 7 (not shown) and the mold material 22 are inserted, and the mold material 22 is inserted from the mold material injection hole 23 of the other mold (the upper mold 20 in the illustrated example) as shown in FIG. Is injected into the molds 20 and 21, and the molding material 22 is injection molded. When the molding part 8 is molded in this way, in addition to the operational effects of molding by the injection molding alone, the sensor unit B and the molding material 22 are put in the lower mold 21 in advance, thereby positioning the sensor unit B. The effect that it becomes easy is obtained.

  In the rotation detection sensor A having the above-described configuration, since the sensor unit B is molded with the molding material 22 made of an elastic rubber material or thermoplastic elastomer, when vibration or external force is applied to the rotation detection sensor A, the vibration or external force is detected. Since the molding part 8 absorbs the influence of the sensor unit B on each sensor part, the sensor part can be protected. Further, since the molding part 8 is made of an elastic rubber material or thermoplastic elastomer, the sensor part and the molding part 8 have different thermal expansion / contraction due to changes in environmental temperature and self-heating of the sensor part which is an electronic part. Even in the case of occurrence of such a phenomenon, the difference can be absorbed by the elasticity of the molding portion 8, and a gap can be prevented from being generated between the sensor component and the molding portion 8, and waterproofness can be maintained.

  In particular, the substrate 11 that is a component of the sensor unit B is fixed to the sensor fixing member 7 by fitting at least two or more concave portions 11 a provided on the substrate 11 to the convex portions 7 d provided on the sensor fixing member 7. Therefore, the sensor unit B can be positioned and fixed to the sensor fixing member 7 with a simple fixing structure.

  Further, in this embodiment, the first and second cable supports having a support surface having an arcuate cross section for supporting a part of the peripheral surface half of the cable 10 at a position away from the molding part 8 of the sensor fixing member 7. A cable comprising a combination of the portions 14 and 15 and a third cable support portion 16 having a support surface having an arcuate cross section that supports the peripheral surface half on the opposite side of the peripheral surface half of the other portion of the cable 10 Since the support unit set 13 is provided, the bending of the cable 10 can be suppressed without caulking the cable 10. In addition, even when a load is applied from the outside, the load can be received by the cable support portions 14, 15, and 16, so that the load can be prevented from being transmitted to the molding portion 8 and the electrode portion 2 of the sensor element 1. . As a result, it is possible to prevent the molding portion 8 from being damaged due to fluctuations in the cable 10 and to ensure the reliability of the rotation detection sensor A.

  In this embodiment, since the sensor fixing member 7 also serves as a cover for the wheel bearing, the rotation detection sensor A can be easily positioned and the number of parts can be reduced. Further, since the sensor fixing member 7 is made of metal, when the molding material is a rubber material, the adhesion between the sensor fixing member 7 and the molding portion 8 is good, and the rotation detection sensor A as a whole has a strong structure. Can do.

  8 and 9 show another embodiment of the rotation detection sensor of the present invention. In the embodiment shown in FIGS. 1 to 4, the rotation detection sensor A of this embodiment fits one concave portion 11 a provided on the substrate 11 to a convex portion 7 d provided on the sensor fixing member 7, and at the same time, the sensor fixing member 7. The substrate 11 is fixed to the sensor fixing member 7 by sandwiching the substrate 11 between the clamping portion 7e provided at a location different from the convex portion 7d and the other portion of the sensor fixing member 7. A concave portion 11a of the substrate 11 is formed by cutting out one end portion of the sensor fixing member 7 facing the circumferential direction, and the convex portion 7d of the sensor fixing member 7 has a mouth of the substrate 11 facing the circumferential direction of the opening portion 7c. It is the same as the case of embodiment shown in FIGS. 1-4 that it cuts and raises to the fixed surface side. The clamping part 7e of the sensor fixing member 7 cuts and raises the edge of the opening 7c facing the circumferential direction opposite to the formation part of the convex part 7d to the fixing surface side of the substrate 11, and then the surface of the substrate 11 is Folded to suppress. Other configurations are the same as those of the embodiment shown in FIGS. In FIG. 8 showing the surface side of the sensor unit B, the illustration of the cable 10 connected to the conductive portion 3 of the substrate 11 is omitted, and in FIG. 9 showing the cross-sectional view, the sensor element 1 and the conductive portion 3 are omitted. The illustration of the cable 10 and the like is omitted.

  In this embodiment, one end of the substrate 11 is clamped by the clamping portion 7e of the sensor fixing member 7, but the other end of the substrate 11 is fitted with the recess 11a of the substrate 11 to 7d of the sensor fixing member 7. The substrate 11 can be positioned and fixed to the sensor fixing member 7. Thereby, the sensor unit B can be positioned and fixed to the sensor fixing member 7 with a simple fixing structure.

  10 and 11 show still another embodiment of the rotation detection sensor of the present invention. In the rotation detection sensor A of this embodiment, in the embodiment shown in FIGS. 1 to 4, the four recesses 11 a formed by cutting out the four corners of the substrate 11 are arranged in the circumferential direction of the opening 7 c of the sensor fixing member 7. The substrate 11 is fixed to the sensor fixing member 7 by fitting with four convex portions formed by cutting and raising the facing edge. Other configurations are the same as those of the embodiment shown in FIGS. In FIG. 10 showing the surface side of the sensor unit B, the illustration of the cable 10 connected to the conductive portion 3 of the substrate 11 is omitted. In FIG. 11 showing the cross-sectional view, the sensor element 1 and the conductive portion 3 are omitted. The illustration of the cable 10 and the like is omitted.

  In this embodiment, since the four corners of the substrate 11 are fixed to the sensor fixing member 7 by fitting, the substrate 11 can be positioned and fixed to the sensor fixing member 7 more reliably. Thereby, the sensor unit B can be more reliably positioned and fixed to the sensor fixing member 7 with a simple fixing structure.

  12 and 13 show a wheel bearing device provided with the rotation detection sensor of the present invention. In this wheel bearing device, as shown in a sectional view in FIG. 12, a rotation detection sensor / fixing member mounting body C in which the rotation detection sensor A is fixed to the sensor fixing member 7 is attached to the bearing portion 30. In the following description, the side closer to the outer side in the vehicle width direction of the vehicle when attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side.

  The bearing portion 30 includes an outer member 31 in which a double row rolling surface 33 is formed on the inner periphery, an inner member 32 in which a rolling surface 34 that faces each of the rolling surfaces 33 is formed, and these outer members. 31 and a double row rolling element 35 interposed between the rolling surfaces 33 and 34 of the inner member 32. The rolling elements 35 in each row are held by a holder 36. Both ends of the bearing space between the outer member 31 and the inner member 32 are sealed by sealing devices 37 and 38, respectively.

  The outer member 31 is a fixed wheel, is an integral part, and is provided with a flange 31a on the outer periphery for attachment to a knuckle (not shown) extending from the suspension device of the vehicle body. The inner member 32 is a rotating wheel, and includes a hub wheel 39 having a wheel mounting flange 39a on the outboard side, and an inner ring 40 fitted to the outer periphery of the inboard side end of the hub wheel 39. Become. The hub ring 39 and the inner ring 40 are formed with the rolling surfaces 34 of the respective rows. The inner member 32 has an axial through hole 41 at the center, and a stem portion (not shown) of one joint member of the constant velocity joint is inserted into the through hole 41.

  In the sealing device 38 on the inboard side of the sealing devices 37 and 38, a magnetic encoder 45 as a detection object is incorporated. The magnetic encoder 45 is provided with a multipolar magnet 45b on a side plate portion of a ring member 45a having an L-shaped cross section. The ring member 45a includes a cylindrical portion that is attached to the outer periphery of the inner member 2 by press fitting, and the side plate portion that extends from the inboard side end of the cylindrical portion to the outer diameter side. The multipolar magnet 45b is a member formed with alternating magnetic poles N and S in the circumferential direction, and is made of a rubber magnet, a plastic magnet, a sintered magnet, or the like. In this embodiment, the magnetic encoder 45 also serves as a component of the inboard side sealing device 38 and functions as a slinger.

The sensor fixing member 7 has a cylindrical portion large-diameter portion 7aa fitted on the outer peripheral surface inboard side of the outer member 31, and the step surface of the cylindrical portion large-diameter portion 7aa and the small-diameter portion 7ab is formed on the outer member 31. It is attached to the outer member 31 in contact with the end face on the inboard side. The sensor fixing member 7 also serves as a cover for the end face on the inboard side of the wheel bearing. In a state where the sensor fixing member 7 is attached, the rotation detection sensor A is positioned facing the magnetic encoder 45.
When the inner member 32, which is a rotating wheel, rotates, the sensor element 1 detects the magnetic poles N and S of the magnetic encoder 45 that rotates with the inner member 32. The detection signal is transmitted to the automobile electric control unit (not shown) via the cable 10, and the rotation speed is calculated from the detection signal of the sensor element 1 by the electric control unit.

The rotation detection sensor A of this embodiment is of a type opposed to the magnetic encoder 45 in the axial direction, but the present invention can also be applied to a type opposed to the magnetic encoder 45 in the radial direction. . As the detected object, a pulse coder may be used instead of the magnetic encoder 45.
Moreover, you may attach the magnetic encoder 45 or pulse coder as a to-be-detected body to the wheel for motor vehicles.
Furthermore, in this embodiment, the sensor fixing member 7 is directly attached to the fixed wheel, but may be attached to the fixed wheel via another member.

(A) is a front view of the rotation detection sensor concerning one Embodiment of this invention, (B) is IB-IB arrow sectional drawing. It is the II section enlarged view of FIG. 1 (A). It is a back surface enlarged view of the II section of Drawing 1 (A). It is an expanded sectional view of the II section of Drawing 1 (A). It is explanatory drawing which shows the shaping | molding method of a mold material. It is explanatory drawing which shows the shaping | molding method of a different mold material. Furthermore, it is explanatory drawing which shows the shaping | molding method of a different mold material. It is a front partial enlarged view of the rotation detection sensor concerning other embodiment of this invention. It is a partial expanded sectional view of the rotation detection sensor. It is a front partial enlarged view of the rotation detection sensor concerning further another embodiment of this invention. It is a partial expanded sectional view of the rotation detection sensor. It is sectional drawing of the wheel bearing apparatus which provided the rotation detection sensor of this invention. It is the front view which looked at the same bearing device from the inboard side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sensor element 2 ... Electrode part 3 ... Conductive part 4 ... Cable core wire 7 ... Sensor fixing member 7d ... Convex part 8 ... Molding part 10 ... Cable 11 ... Substrate 11a ... Concave part 20 ... Upper die (mold)
21 ... Lower mold (mold)
22 ... Mold material 45 ... Magnetic encoder (detected body)
A ... Rotation detection sensor B ... Sensor unit

Claims (8)

  A rotation detection sensor that is fixed to a sensor fixing member that is attached to a wheel bearing and detects rotation of a rotating wheel of the wheel bearing, and a magnetic sensor element that detects a detection object provided on the rotating wheel; A board having a cable for outputting an output signal of the sensor element to the outside, and a conductive part to which the sensor element and one end of the cable are attached and electrically connecting the electrode part of the sensor element and the core wire of the cable The sensor unit is fixed to the sensor fixing member by fitting at least one concave portion or convex portion provided on the substrate to the convex portion or concave portion provided on the sensor fixing member. In addition, the sensor unit is covered and a molding part is formed by molding a molding material made of thermoplastic elastomer or rubber material. Rotation detecting sensor to symptoms.   In Claim 1, the molding is molding using a mold, the mold is composed of an upper mold and a lower mold, and a mold material composed of the sensor unit and a rubber material is inserted between the upper mold and the lower mold, A rotation detection sensor in which the molding part is compression-molded by applying pressure between both molds while heating the upper mold and the lower mold.   2. The molding according to claim 1, wherein the molding is injection molding using a mold, and the molding part is injection molded by placing a sensor unit in the mold and injecting a thermoplastic elastomer into the mold. Rotation detection sensor.   2. The rotation according to claim 1, wherein the molding is injection molding using a mold, and the molding part is injection molded by placing a sensor unit in the mold and injecting a rubber material into the mold. Detection sensor.   2. The molding according to claim 1, wherein the molding is performed using a mold composed of an upper mold and a lower mold. A rubber material is previously placed in one of the upper mold and the lower mold, and the rubber material is injected from the other mold. A rotation detection sensor formed by molding the molding part.   6. The rotation detection sensor according to claim 1, wherein the sensor element is a Hall element, a magnetoresistive effect element, a giant magnetoresistive effect element, a tunnel magnetoresistive element, or a coil.   7. The rotation detection sensor according to claim 1, wherein the sensor fixing member is attached to a fixed wheel of a wheel bearing or a peripheral member thereof.   8. The rotation detection sensor according to claim 1, wherein the sensor fixing member also serves as a cover that covers an end surface of the wheel bearing.

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