JP6137546B2 - Rotation detector - Google Patents

Description

  The present invention relates to a rotation detection device that detects rotation of a detection target based on rotation of a rotor.

  2. Description of the Related Art Conventionally, a rotation detection device that detects the rotational speed of a wheel has a magnetized rotor that rotates integrally with a wheel shaft at a predetermined position, and detects a magnetic field variation due to the rotation of the magnetized rotor with a sensor element or the like. It is configured. And the rotation speed detection of the wheel is performed based on the signal waveform which a sensor element outputs.

  For example, according to the technique disclosed in Patent Document 1, the means for fixing the sensor element to the fixing member is a resin material, and the resin material is injected and filled between the sensor element and the fixing member by insert molding. It is done by.

Japanese Patent Laid-Open No. 2005-233849

  However, since the conventional technology described above is configured such that the molten resin at the time of injection molding directly contacts the detection unit including the sensor element, the resin pressure and the resin temperature of the molten resin are directly applied to the sensor element. There is a problem that.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a rotation detection device in which a resin pressure and a resin temperature of a molten resin are not easily applied to a detection unit.

In order to achieve the above object, the invention according to claim 1 includes a rotation detection object (103) provided in a rotating part (101a) of a rotating shaft (100) and a fixed part (101b) of a bearing (101). A sensor body (10) fixed to the sensor ring (1) by a resin member (2) so that the detection surface (10b) keeps a predetermined gap between the sensor ring (1) and the rotation detection target (103). The rotation detection device (A) includes a protective member (3, 3a) that covers the outer peripheral surface of the sensor body (10) and is attached so that at least the detection surface (10b) side of the sensor body (10) is open. the protective member (3) includes a ceiling portion (31), and a side portion (32, 32) comprising a two-legged, characterized in tunnel-shaped der Rukoto recessed upwardly from the bottom of the side And

  According to this configuration, the rotation detection device includes the protective member (3, 3a) that covers the outer peripheral surface of the sensor body (10) and is attached so that at least the detection surface (10b) of the sensor body (10) is opened. . Therefore, since the outer peripheral surface of the sensor body (10) is covered with the protective member (3, 3a), molten resin is used to fix the sensor body (10) to the sensor ring (1) with the resin member (2). When filling, since the resin pressure and the resin temperature are not directly applied to the sensor body (10), the sensor body (10) can be prevented from being damaged and the reliability can be improved. . Further, since at least the detection surface (10b) side of the sensor main body (10) is open, the protection member (3, 3a) is reliably detected with the detection surface (10b) facing the rotation detection target (103). It has an excellent effect that it can be performed.

It is the schematic which shows the whole structure of the rotation detection apparatus of this invention with the II sectional view taken on the line of FIG. It is the schematic which shows the whole structure of the rotation detection apparatus provided with the protection member of a deformation | transformation aspect. It is a perspective view which shows the form which integrated the sensor ring, the protection member, and the sensor main body by outsert molding. It is a perspective view of a sensor ring. It is a perspective view of a protection member. It is a perspective view of a sensor main body. It is a perspective view which shows the form which attached the protection member and the sensor main body to the sensor ring for outsert molding.

  Hereinafter, an embodiment in which the rotation detection device of the present invention is embodied will be described with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals, and description of the overlapping parts will be omitted as appropriate.

  The rotation detection device A of this embodiment is a device that is mounted on a vehicle and detects the rotational speed of a wheel. FIG. 1 schematically shows a state in which the rotation detection device A is attached to a vehicle body. As shown in FIG. 1, a bearing 101 is provided on the outer peripheral portion of the wheel shaft (rotary shaft of the present invention) 100 near the wheel. The bearing 101 includes an inner ring (rotating part of the present invention) 101a and outer ring (fixed part of the present invention) 101b having different radii and rolling elements 101c. The inner ring 101a is fixed to the outer peripheral surface of the wheel shaft 100 and rotates together with the wheel shaft 100, and the outer ring 101b is fixed to the vehicle body (not shown). In addition, oil seals 102 are provided at both ends of the inner ring 101a and the outer ring 101b so as to be sandwiched between the inner ring 101a and the outer ring 101b so that the grease filled between the inner ring 101a and the outer ring 101b does not leak. It has become. On the side surface side of the oil seal 102, a magnetized rotor (rotation detection target of the present invention) 103 is connected to the inner ring 101a via a rotating member integral with the inner ring 101a, and is configured to rotate as the inner ring 101a rotates. Has been.

  The magnetized rotor 103 is a ring-shaped rotor, and is magnetized alternately with N and S poles in the circumferential direction, and is arranged coaxially with the wheel shaft 100 so as to surround the outer periphery of the wheel shaft 100.

  The outer ring 101 b of the bearing 101 is fixed to the vehicle body side and is provided so as not to rotate integrally with the wheel shaft 100. A fitting portion 101e is provided on the outer peripheral portion of the outer ring 101b, and the outer ring 101b and the sensor ring 1 are coupled with each other by being fitted to the inner side surface of the outer peripheral portion 1a of the sensor ring 1 so as to be integrated. Has been. At this time, in order to strengthen the coupling between the outer ring 101b and the sensor ring 1, it is desirable that both are coupled by press-fitting.

  As shown in FIG. 4, the sensor ring 1 is formed by bending a metal flat plate and is formed in a ring shape as a whole. The sensor ring 1 shown in FIG. 1 is shown in the cross-sectional shape of the part to which the sensor main body 10 is attached, and the outer peripheral portion 1a has a longer U shape than the inner peripheral portion 1e that is the other side. As shown in FIGS. 3, 4, and 7, the portion of the sensor ring 1 where the sensor body 10 is not attached is perpendicular to the outer peripheral portion 1 a that fits the outer ring 101 b of the bearing 101 and one end portion of the outer peripheral portion 1 a. An outer connecting portion 1b extending in the direction from the end of the outer connecting portion 1b opposite to the outer peripheral portion 1a side, and a middle step portion 1c extending perpendicularly in the opposite direction to the outer peripheral portion 1a, and the outer side of the intermediate step portion 1c. An inner connecting portion 1d extending perpendicularly in the opposite direction to the outer connecting portion 1b from an end opposite to the connecting portion 1b side, and an intermediate connecting portion 1d from the end opposite to the outer connecting portion 1b An inner peripheral portion 1e extending in a shape that is folded vertically to the middle step portion 1c direction side is continuously formed, and has a shape having a step portion on the outer peripheral surface.

  When the sensor ring 1 is fitted into the fitting portion 101e of the outer ring 101b, the inner side surface of the outer connecting portion 1b is the fitting portion 101e that forms a gap G3 between the surface and the detection surface 10b of the sensor body 10. Abuts against the end face. As a result, the bearing 101 and the sensor ring 1 in the axial length direction of the rotary shaft 100 are positioned with high accuracy, and the variation in the gap G4 between the magnetized rotor 103 and the detection surface 10b of the sensor body 10 is effectively suppressed. . In the present embodiment, the gap G3 is 0.3 mm, and the gap G4 is 0.5 to 0.6 mm (the median value when G3 and G4 are both stationary). That is, the gap G4 between the detection surface 10b of the sensor main body 10 and the magnetized rotor 103 is stably secured in a state where none of the surfaces of the sensor main body 10 is in contact with the outer ring 101b.

  As shown in FIGS. 1 and 6, the sensor body 10 includes a rotation detection IC 10a having a rotation detection element. The rotation detection IC 10a includes an MRE (Magneto Resistive Effect) element or a Hall element as a sensing element that generates an output accompanying a change in a magnetic field, and a signal processing circuit that processes an output signal. IC chips and magnets are molded with epoxy resin or the like.

  The rotation detection IC 10a forms a detection surface 10b facing the magnetized rotor 103 on one end side of a hollow case. In addition, a wire 10c formed by twisting a plurality of fine wires is extended to the other end side of the case in order to transmit an input / output signal of the rotation detection IC 10a. This wire 10c is connected to an external device such as an ECU (Electronic Control Unit) for ABS (Anti-Lock Bracket System) control through a connector or the like.

  As shown in FIGS. 1 and 5, the protective member 3 has a tunnel shape having a ceiling portion 31 made of hard plastic or metal and side portions 32, 32 formed of two legs and having a shape recessed upward from the bottom portion. It is a member. However, if the side that appears to be open in FIG. 5 is assumed to be an inlet, the shape of the inlet and its surroundings are preferably appropriately deformed according to the outer shape of the sensor body 10. Moreover, as shown in FIG. 2, the protection member 3a as a modification has a shape in which the opposite side (exit) of the entrance of the tunnel is closed. In this case, the protective member 3a adheres to the front end surface of the sensor main body 10 in addition to the other three side surfaces excluding the detection surface 10b of the sensor main body 10. The protective member may be one that lacks one or more of the above-described three side surfaces and one end surface of the sensor body 10.

  As shown in FIGS. 1, 2, and 7, the protection members 3 and 3 a are attached to the outer peripheral surface of the sensor body 10 so that the bottom of the tunnel is substantially flush with the detection surface 10 b of the sensor body 10. As a result, the detection surface 10 b side of the sensor body 10 is opened and is configured to face the magnetized rotor 103.

  As shown in FIGS. 4 and 7, the sensor main body 10 to which the protection member 3 is attached is inserted into the mounting hole 4 of the sensor ring 1. The thing of this state is arrange | positioned so that the outer periphery and bottom part of the side parts 32 and 32 other than the ceiling part 31 of the protection member 3 may contact with the metal mold cavity which is not illustrated, and it positions correctly in a metal mold cavity. Outsert molding is performed by an injection molding machine (not shown). Thereby, the sensor main body 10 and the protection member 3 outsert to the sensor ring 1 are fixed to the sensor ring 1 by the resin member 2 and integrated.

  In the outsert molding, as shown in FIGS. 1 and 2, the plasticized molten resin of the resin member 2 made of PBT, polyamide, or the like is injected from a gate provided at an appropriate location in the mold cavity, This is done by filling the cavity.

  At this time, the molten resin enters between the inner coupling portion 1d of the sensor ring 1 and the protective members 3 and 3a from the gap G1, and applies the resin pressure and the resin temperature of the molten resin to the protective members 3 and 3a.

  Further, a gap G <b> 2 is provided between the inner side surface of the protection members 3 and 3 a and the back surface of the detection surface 10 b of the sensor body 10. The gap G2 is changed according to the shape and material of the protective member 3 and the type of the resin member 2, and is set to be 0.05 to 0.2 mm when the molten resin is not injected. In this setting, when the sensor body 10 and the protection member 3 are positioned on the mold cavity surface, both the legs of the detection surface 10b and the protection member 3 come into contact with the same cavity surface. Therefore, the leg length H of the protection member 3 shown in FIG. This can be done by adjusting

  When molten resin is injected into the mold cavity, the protective members 3 and 3a bend to reduce the gap G2 by the resin pressure, but the bent portion does not come into contact with the back surface of the detection surface 10b of the sensor body 10. In addition, a gap G2 is set. The molten resin enters the gap G2. However, since the gap G2 is relatively small as described above, the flow of the molten resin at the time of molding is limited, and the penetration length of the molten resin into the gap G2 is about 2 to 3 mm or less from the end surfaces of the protective members 3 and 3a. Can be suppressed. Therefore, the rotation detection IC 10a is protected from the resin pressure and the resin temperature over the entire circumference.

  A through hole 5 is drilled at a position in the vicinity of both sides of the mounting hole 4 in the outer peripheral portion 1 a of the sensor ring 1 and inside the resin member 2. The through-hole 5 flows the molten resin in the front and back direction of the sensor ring 1 during outsert molding, and improves the fixing strength between the resin member 2 formed by solidifying the molten resin and the sensor ring 1.

  A through hole 5 a is drilled at a position in the vicinity of the attachment hole 4 in the inner coupling portion 1 d of the sensor ring 1 and inside the resin member 2. The through holes 5a flow the molten resin in the front and back directions of the sensor ring 1 during the outsert molding, and improve the fixing strength between the resin member 2 formed by solidifying the molten resin and the sensor ring 1.

  As is clear from the above detailed description, the rotation detection device A of the present embodiment covers the outer peripheral surface of the sensor body 10 and is attached so that at least the detection surface 10b of the sensor body 10 is opened. Is provided. Therefore, since the outer peripheral surface of the sensor main body 10 is covered with the protective member 3, when the molten resin is filled to fix the sensor main body 10 to the sensor ring 1 with the resin member 2, the resin pressure and the resin temperature are increased. Since it is not applied directly to the sensor body 10, the sensor body 10 (particularly the rotation detection IC 10a) can be prevented from being damaged and the reliability can be improved. Further, since at least the detection surface 10b side of the sensor body 10 is opened, the protective member 3 has an excellent effect that the detection can be reliably detected with the detection surface 10b facing the magnetized rotor 103.

  Further, since the protection member 3 has a tunnel shape, it can be easily attached to the sensor body 10 and can effectively protect the sensor body 10 from the resin pressure and the resin temperature of the molten resin.

  Further, since the protective member 3a has a shape in which one end of the tunnel is closed, it can be more easily attached to the sensor body 10, and the sensor body 10 is extremely effective from the resin pressure and the resin temperature of the molten resin. Can be protected.

  Further, since the resin member 2 is formed by outsert molding that integrally couples the sensor ring 1, the sensor body 10, and the protection member 3, it is possible to fix them extremely efficiently and effectively. it can.

  Moreover, since the sensor ring 1 is provided with the through-hole (5, 5a) which distribute | circulates the molten resin of the resin member 2, the fixing strength to the sensor ring 1 of the sensor main body 10 can be improved.

  In addition, this invention includes what can be implemented in the aspect which added various change, correction, improvement, etc. based on the knowledge of those skilled in the art. Further, it goes without saying that any of the embodiments to which the above-mentioned changes are added is included in the scope of the present invention without departing from the gist of the present invention.

A Rotation detection device 1 Sensor ring 2 Resin member 3 Protective member 5, 5a Through hole 10 Sensor body 10b Detection surface 100 Vehicle shaft (rotary shaft)
101 Bearing 101a Inner ring (rotating part)
101b Outer ring (fixed part)
103 Magnetized rotor (rotation detection target)

Claims (5)

The rotation detection object (103) provided on the rotation part (101a) of the rotation shaft (100) and the rotation detection object (103) on the sensor ring (1) fixed to the fixing part (101b) of the bearing (101). In the rotation detection device (A) including the sensor body (10) fixed by the resin member (2) so that the detection surface (10b) maintains a predetermined gap between
A protective member (3, 3a) that covers the outer peripheral surface of the sensor body (10) and is attached so that at least the detection surface (10b) side of the sensor body (10) is open ;
The protective member (3) has a ceiling part (31) and side parts (32, 32) formed of two legs, and has a tunnel shape recessed upward from the bottom part of the side part. Rotation detection device. The rotation detection device according to claim 1 , wherein the protection member (3a) has a shape in which one end of the ceiling portion and the side portion is further closed. The rotation detection device according to claim 1 or 2 , wherein the sensor body (10) includes a rotation detection IC (10a) having a rotation detection element .   The said resin member (2) is formed by the outsert molding which couple | bonds the said sensor ring (1), the said sensor main body (10), and the said protection member (3) integrally. The rotation detection device according to any one of 1 to 3.   The rotation detection device according to any one of claims 1 to 4, wherein the sensor ring (1) includes a through hole (5, 5a) through which the molten resin of the resin member (2) flows.

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