JP2009264941A - Rotation speed detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation speed detection device manufactured at low cost. <P>SOLUTION: This rotation speed detection device 1 comprises a bar-like sensor section 2 having a detection section 20 having a surface 20a becoming a detection surface at its one end, a ring section 3 having a cylindrical outer cylinder section 30 engaged with a bearing outer ring 62 that does not rotate with respect to a bearing inner ring 60 for holding a rotator 64 to be detected facing the detection section 20 and an annular flange section 31 that is formed at one end of the outer cylinder section 30 and extends in the inner diameter direction, and a resin mold section 4 resin-molded so as to fix the sensor section 2 to the ring section 3 in the state where the detection section 20 is inserted into a sensor insertion hole 33 opened at least in the outer cylinder section 30 from the outer peripheral side to the inner peripheral side and in the state where the detection surface 20a of the detection section 20 is held at a position separated from the surface of the rotator 64 by a predetermined interval. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotation speed detection device that detects a rotation speed of a rotating body that rotates with rotation of a rotation shaft.

  Generally, a plurality of rotational speed detection devices such as a sensor for detecting the rotational speed of a wheel and a sensor for detecting the rotational speed of an engine are assembled in a vehicle.

  Among these rotational speed detection devices, the wheel speed sensor detects the rotation of the rotating body rotating together with the wheel shaft formed on the rotating wheel shaft, and obtains the rotational speed of the wheel from the detection signal. Such rotational speed detection devices are disclosed in, for example, Patent Documents 1 to 3.

  A conventional rotational speed detection device has a configuration in which a sensor for detecting the rotation of a rotating body and a ring-shaped member for fixing the sensor at a position where the rotation of the rotating body can be detected are integrally formed. The sensor is included in the inside of the shaped member.

And since the bearing shape and size of the undercarriage varies from vehicle to vehicle, this ring-shaped member needs to have a shape corresponding to each bearing to be assembled, and the sensor part can be newly designed accordingly. It was requested. That is, there is a problem that a sensor for detecting the rotation of the rotating body needs to be designed for each bearing to be assembled, so that a great cost is required.
JP-A-6-320902 JP-A-8-29440 JP 2007-85906 A

  This invention is made | formed in view of the said actual condition, and makes it a subject to provide the rotational speed detection apparatus which can be manufactured at low cost.

Means and effects for solving the problems

  In order to solve the above-mentioned problems, the present inventor has studied the rotational speed detection device, and as a result, has reached the present invention.

  In other words, the rotational speed detection device of the present invention described in claim 1 includes a rod-shaped sensor portion having a detection portion whose surface is a detection surface formed at one end, and a detected rotating body facing the detection portion. A ring portion having a cylindrical outer tube portion that is fitted to a bearing outer ring that does not rotate with respect to the bearing inner ring that is held, and an annular flange portion that is formed at one end of the outer tube portion and extends in the inner diameter direction And a position where the detection part is inserted from the outer peripheral side to the inner peripheral side in at least the sensor insertion hole opened in the outer cylinder part, and the detection surface of the detection part is spaced from the surface of the rotating body by a predetermined distance. And a resin mold part that is resin-molded so as to fix the sensor part and the ring part.

  In the rotational speed detection device of the present invention, the sensor portion is integrally fixed to the ring portion with the resin mold portion while the detection surface is held at a predetermined position. This configuration indicates that the detection device can be obtained by forming the sensor portion and the ring portion separately and resin molding. That is, the sensor for detecting the rotation of the rotating body and the ring portion for fixing the detection device to the mating member can be manufactured separately, and can be manufactured by resin molding. That is, the sensor unit can be a standard sensor, and the detection device can be manufactured at low cost.

  Moreover, a detection part is fixed and it becomes the structure which the main-body part of the sensor part protruded from the outer peripheral surface of the outer cylinder part of a ring part. At this time, it is possible to freely set the direction in which the main body portion of the sensor portion protrudes.

  Furthermore, since the outer cylinder of the ring portion is shaped to be fitted to the bearing outer ring, the design change according to the dimensions of the bearing outer ring can be easily performed.

  Thus, in the rotational speed detection device of the present invention, the standard type sensor unit for detecting the rotation of the rotating body and the ring unit for fixing the sensor unit to the bearing outer ring can be formed separately, and as a result, The detection device can be manufactured at low cost.

  According to a second aspect of the present invention, there is provided the rotational speed detection device according to the first aspect of the present invention, wherein the ring portion has a cylindrical outer cylinder portion that is partly smaller than the fitting portion and contacts the end surface of the bearing outer ring. A stepped portion to be in contact is formed.

  Since the ring portion has the stepped portion, the axial position of the ring portion with respect to the bearing outer ring can be fixed. Thereby, the axial direction position with respect to the to-be-detected rotary body of the detection surface of a sensor part can be fixed.

  According to a third aspect of the present invention, there is provided the rotational speed detecting device according to the second aspect, wherein the stepped portion is formed over substantially the entire circumference of the portion where the detecting portion of the sensor portion is not disposed. .

  By forming the stepped part over almost the entire circumference of the ring part, it is possible to prevent the flange part from being tilted and assembled, and the inclination of the detection surface of the sensor part relative to the rotating body can be suppressed to achieve positional accuracy. Can be kept high.

  According to a fourth aspect of the present invention, there is provided the rotational speed detecting device according to any one of the first to third aspects, wherein the ring portion has a cylindrical shape extending on the inner diameter side of the flange portion in the same direction as the outer cylindrical portion extends. It has an inner cylinder part, It is characterized by the above-mentioned.

  By having the inner cylinder part, the scattered matter from the radially inner side (rotating shaft that rotates together with the detected rotating body) hits the sensor part, etc., and is detected between the detecting surface and the rotating body. Can be suppressed. Furthermore, by disposing a seal member between the inner peripheral surface on the axial center side of the inner cylinder part and the rotating member, it is possible to further prevent the intrusion of scattered objects.

  According to a fifth aspect of the present invention, in the rotational speed detection device of the present invention, in any one of the first to fourth aspects, the stepped portion has an axial end surface that abuts the bearing outer ring protruding beyond the detection surface of the sensor portion. It is characterized by being.

  Since the end surface in the axial direction of the stepped portion protrudes from the detection surface, the detection surface of the sensor portion does not contact the bearing outer ring. Thereby, it can suppress that a detection surface contact | abuts a bearing outer ring | wheel and a detection part produces a failure.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the resin mold portion is formed on both sides of the sensor insertion hole.

  The sensor insertion hole is formed larger than the outer peripheral shape of the detection unit in order to insert the detection unit from the radially outer side to the radially inner side. For this reason, in the state which inserted the detection part, a clearance gap exists between a sensor part (detection part) and a ring part. And since a resin mold part is formed in the both sides of a sensor insertion hole so that this clearance may be filled, a sensor part (detection part) and a ring part can be fixed more firmly.

  According to a seventh aspect of the present invention, in the rotational speed detection device of the present invention, in any one of the first to sixth aspects, a through hole is formed in the flange portion, and a resin mold portion is formed on both sides of the through hole. It is characterized by.

  By forming the resin mold part on both sides of the through hole of the flange part, the sensor part (detection part) and the ring part can be more firmly fixed.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the sensor unit detects the magnetic field of the detected rotating body.

  That is, the sensor unit can be a sensor that detects a magnetic field change from a magnetic field generated when the detected rotating body rotates. An inexpensive standard sensor can be used for such a sensor, and as a result, the detection device can be manufactured at low cost.

  According to a ninth aspect of the present invention, in the rotational speed detection device of the present invention, in any one of the first to eighth aspects, the resin mold portion is resin-molded in a state where the detection surface and the side surface of the detection portion of the sensor portion are held by a mold. It is characterized by that.

  By forming the resin mold portion with the detection surface of the detection portion held by a mold, the position of the detection surface can be set to a predetermined position. Furthermore, the positioning accuracy of the detection surface is improved.

  According to a tenth aspect of the present invention, in the rotational speed detection device of the present invention, in any one of the first to ninth aspects, a part of the resin mold part is formed on both sides of the detection surface of the sensor part, Is located on the flange side of the stepped portion and at a position protruding from the sensor portion.

  Since a part of the resin mold portion protrudes from the detection surface of the sensor portion, the detection surface of the sensor portion does not contact the bearing outer ring. Thereby, it can suppress that a detection surface contact | abuts a bearing outer ring | wheel and a detection part produces a failure. In addition, since a part of the resin mold portion does not protrude from the stepped portion, the fixing of the axial position of the sensor portion by the stepped portion is not hindered.

  Hereinafter, the present invention will be described using specific embodiments.

  A wheel speed sensor was manufactured as an embodiment of the rotational speed detection device of the present invention.

(First embodiment)
The wheel speed sensor 1 of the present embodiment includes a sensor unit 2, a ring unit 3, and a resin mold unit 4. The wheel speed sensor 1 of this embodiment is shown in FIG.

  As shown in FIG. 2, the sensor unit 2 includes a substantially rectangular plate-shaped detection unit 20 having one surface serving as a detection surface 20a, and a rod-shaped (columnar) main body in which the detection unit 20 is fixed to one end. And a conductor 22 that transmits a detection signal of the detector 20 protruding from the other end of the main body 21.

  The detection unit 20 of the sensor unit 2 detects a change in the magnetic field on the detection surface 20a. The main body 21 is a rod-shaped member extending along the direction in which the detection surface 20a of the detection unit 20 extends. The main body 21 has a diameter larger than the width of the detection unit 20.

  In the present embodiment, the sensor unit 2 is a standard magnetic sensor.

  As shown in FIG. 3, the ring portion 3 is formed of a metal plate, and has a cylindrical outer cylinder portion 30 that is fitted to a bearing outer ring that does not rotate with respect to the bearing inner ring that holds the detected rotating body. An annular flange portion 31 that is formed in one end portion of the outer cylinder portion 30 and is perpendicular to the axial direction and extends in the inner diameter direction, and the same as the outer cylinder portion 30 from the inner diameter side end portion of the flange portion 31. A cylindrical inner cylinder portion 32 extending in the direction.

  In the ring portion 3, a sensor insertion hole 33 into which the detection portion 20 of the sensor portion 2 can be inserted is opened at one end portion where the flange portion 31 of the outer cylinder portion 30 is formed. The sensor insertion hole 33 is opened in a state where a part of the outer cylinder portion 30 and the flange portion 31 are missing. The sensor insertion hole 33 has a substantially rectangular opening shape into which the detection unit 20 of the sensor unit 2 can be inserted and the main body unit 21 cannot pass through.

  The ring portion 3 includes a step 34b and a portion 34b having a diameter smaller than that of the outer cylinder portion 30 over almost the entire circumference in a circumferential direction excluding a portion other than the vicinity of the sensor insertion hole 33 at an end portion on the outer peripheral side of the flange portion 31. Attached portion 34 is formed. An end surface 34 a in the axial direction of the stepped portion 34 is formed in parallel with the direction in which the flange portion 31 spreads. Further, the inner surface 34 b of the stepped portion 34 is coaxial with the outer cylinder portion 30 and the inner cylinder portion 32, and is formed in parallel with the cylinder portions 30 and 32.

  Through holes 35 are opened on both sides in the circumferential direction of the portion where the sensor insertion hole 33 of the flange portion 31 of the ring portion 3 is opened. The through-hole 35 is open to a portion (a position in the circumferential direction) where the stepped portion 34 is not formed.

  As shown in FIG. 3, the resin mold part 4 integrally fixes the sensor part 2 and the ring part 3 in a state where the detection part 20 of the sensor part 2 is inserted into the sensor insertion hole 33 of the ring part 3. Thus, it is formed by resin molding.

  The resin mold portion 4 includes the sensor portion 2 and the ring portion 3 on the inner peripheral surface side (surface side facing the rotating body) and the outer peripheral surface side (surface side facing away from the inner peripheral surface) of the ring portion 3. It is buried inside. The resin mold portion 4 is formed on both sides of the sensor insertion hole 33 and the through hole 35 and fixes the inner peripheral surface side and the outer peripheral surface side of the ring portion. The resin mold portions 4 formed on both sides of the sensor insertion hole 33 and the through hole 35 are connected by the holes 33 and 35 and are firmly fixed on the inner peripheral surface side and the outer peripheral surface side of the ring portion 3. Yes.

  As shown in FIG. 4, the resin mold portion 4 is injected with resin while the detection surface 20 a and the side surfaces 20 b, c and d of the sensor portion 2 and the main body portion 21 are held and fixed by the mold 5. Molded. With this mold 5, the detection surface 20 a of the detection unit 20 is held at a position closer to the flange portion 31 than the end surface 34 a of the stepped portion 34 in the axial direction. Thereby, the detection surface 20a of the sensor unit 2 is formed to extend to a position closer to the flange portion 31 than the end surface 34a of the stepped portion 34.

  Further, resin molding is performed with the molding die 5 holding the side surfaces 20b, c, d of the detection unit 20 of the sensor unit 2, and even after the resin mold unit 4 is formed, the side surfaces 20b, c and d are exposed.

  The wheel speed sensor 1 of the present embodiment is assembled to the hub unit 6 as shown in FIG. 5, for example.

  A flange 61 for fixing a wheel is provided at an outer end portion of the hub 60. The outer ring 62 has a mounting portion 65 formed on the outer peripheral surface for supporting a knuckle (not shown) of the suspension device. A plurality of rolling elements 63, 63 are provided between the hub 60 and the outer ring 62, and the hub 60 is rotatably supported inside the outer ring 62 supported by the suspension device by the mounting portion 65. Yes. A disk-shaped magnetic encoder 64 is fixed to the inner end of the hub 60 in a state of spreading in the radial direction.

  In the wheel speed sensor 1 of the present embodiment, the outer cylinder portion 30 of the ring portion 3 is fitted to the outer periphery of the outer ring 62. The sensor unit 2 is fixed to the ring unit 3 by the resin mold unit 4, and the detection surface 20 a of the detection unit 20 of the sensor unit 2 faces the magnetic encoder 64. Here, between the inner peripheral surface of the outer end 62 of the outer ring 62 or the inner peripheral surface of the inner cylindrical portion 31 of the ring portion 3 and the outer peripheral surface of the hub 60, sealing materials 66, 66 are attached, and a plurality of rolling members are attached. Both end openings of the space in which the moving bodies 63 and 63 and the magnetic encoder 64 are provided are closed.

  When the vehicle including the hub unit 6 travels, the hub 60 rotates. As the hub 60 rotates, the magnetic encoder 64 rotates, and the nearby magnetic field changes. This change in the magnetic field is detected by the detection unit 20 of the sensor unit 2 of the wheel speed sensor 1 and transmitted to the outside through the conductive wire 22. An arithmetic unit such as an ECU (not shown) that has received the detection signal calculates the speed of the vehicle from the detection signal.

  As described above, the wheel speed sensor 1 of the present embodiment can use a standard magnetic sensor for the sensor unit 2 and can form the sensor 1 at a low cost. In addition, the outer peripheral shape of the outer ring 62 of the hub unit 6 and the shape of the outer cylindrical portion 30 of the ring portion 3 can be easily formed. That is, the wheel speed sensor 1 of the present embodiment can easily change the design according to the outer peripheral shape of the outer ring 62.

  Furthermore, in the wheel speed sensor 1 of the present embodiment, the main body portion 21 of the sensor portion 2 extends outward in the radial direction of the hub 2. That is, the main body 21 does not protrude in the axial direction of the bearing. Thereby, the wheel speed sensor 1 of this embodiment does not become long in the whole axial direction length. As a result, it can be set as the structure which is easy to avoid interference with the knuckle which is not shown in figure.

(Second embodiment)
This embodiment is a wheel speed sensor similar to that of the first embodiment except that the sensor unit 2 is assembled to the ring unit 3 in a state of extending in the axial direction of the rotation axis. The sensor constituting the sensor unit 2 of the present embodiment is shown in FIG. 6 in a state where the sensor is assembled to the hub unit 6 of the vehicle as in FIG.

  In the wheel speed sensor of the present embodiment, the sensor insertion hole 33 into which the sensor unit 2 is inserted from the outer peripheral surface side to the inner peripheral surface side of the ring portion 3 is located at a position straddling the outer cylinder portion 30 and the flange portion 31. It is open.

  As for the wheel speed sensor of this embodiment, the main-body part 21 of the sensor part 2 has extended in the axial direction. That is, the entire physique of the wheel speed sensor does not spread in the radial direction. Except for this, as in the first embodiment, it is possible to achieve an effect that can make it easy to avoid interference with the knuckle.

It is the figure which showed the wheel speed sensor of 1st embodiment. It is the figure which showed the sensor which comprises the sensor part of the wheel speed sensor of 1st embodiment. It is the figure which showed the sensor part and ring part of the wheel speed sensor of 1st embodiment. It is the figure which showed the structure of the shaping | molding die which shape | molds the resin mold part of the wheel speed sensor of 1st embodiment. It is the figure which showed the state by which the wheel speed sensor of 1st embodiment was assembled | attached to the hub unit. It is the figure which showed the state by which the wheel speed sensor of 2nd embodiment was assembled | attached to the hub unit.

Explanation of symbols

1: Wheel speed sensor 2: Sensor part 20: Detection part 21: Body part 22: Conductor 3: Ring part 30: Outer cylinder part 31: Flange part 32: Inner cylinder part 33: Sensor insertion hole 34: Stepped part 35: Through-hole 4: Resin mold part 5: Mold 6: Hub unit 60: Hub 61: Flange 62: Outer ring 63: Rolling element 64: Magnetic encoder 65: Mounting part 66: Seal member

Claims (10)

A rod-shaped sensor part having a detection part whose surface is a detection surface formed at one end; and
A cylindrical outer tube portion that is fitted to a bearing outer ring that does not rotate with respect to the bearing inner ring that holds the detected rotating body facing the detection portion, and an inner diameter direction formed at one end of the outer tube portion An annular flange portion extending to the ring portion,
At least the sensor insertion hole opened in the outer cylinder part is in a state where the detection part is inserted from the outer peripheral side to the inner peripheral side, and the detection surface of the detection part has a predetermined distance from the surface of the rotating body. A resin mold part that is resin-molded so as to fix the sensor part and the ring part while being held at a separated position;
A rotational speed detection device comprising:   2. The rotation according to claim 1, wherein the ring portion has a cylindrical outer cylinder portion that is partially smaller than the fitting portion, and is formed with a stepped portion that contacts an end surface of the bearing outer ring. Speed detection device.   The rotational speed detection device according to claim 2, wherein the stepped portion is formed over substantially the entire circumference of a portion of the sensor unit where the detection unit is not disposed.   The rotational speed detection device according to any one of claims 1 to 3, wherein the ring portion has a cylindrical inner tube portion extending in the same direction as the outer tube portion extends on an inner diameter side of the flange portion.   The rotational speed detection device according to any one of claims 1 to 4, wherein the stepped portion has an axial end surface that abuts on the bearing outer ring protrudes from the detection surface of the sensor portion.   The rotational speed detection device according to claim 1, wherein the resin mold part is formed on both sides of the sensor insertion hole.   The rotational speed detection device according to any one of claims 1 to 6, wherein a through hole is formed in the flange portion, and the resin mold portion is formed on both sides of the through hole.   The rotational speed detection device according to claim 1, wherein the sensor unit detects a magnetic field of the detected rotating body.   The rotational speed detection device according to claim 1, wherein the resin mold part is resin-molded in a state where the detection surface and side surfaces of the detection part of the sensor part are held by a mold.   A part of the resin mold part is formed on both sides of the detection surface of the sensor part, and the end face of the part is on the flange side of the stepped part and in a position protruding from the sensor part. Item 10. The rotational speed detection device according to any one of Items 1 to 9.

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