JP2015052494A - Cable-equipped electronic module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable-equipped electronic module that can reduce an effect of an external magnetic field.SOLUTION: A sensor module 2 comprises: a magnetic sensor 31 formed by a magnetic encoder 6 for detecting magnetism; a cable 30 for transmitting a detection signal of the magnetic sensor 31; a first molded body 21 composed of a non-magnetic material for retaining the magnetic sensor 31; and a second molded body 22 and a third molded body 23 composed of magnetic materials scattered in non-magnetic materials for retaining the first molded body 21. The second molded body 22 and the third molded body 23 retain the first molded body 21 on an area except for at least part of an area between the magnetic encoder 6 and the magnetic sensor 31.

Description

  The present invention relates to an electronic module with a cable having a detection element held by a holding member.

  2. Description of the Related Art Conventionally, as an electronic module with a cable, for example, a vehicle rotation detection device that is mounted on a vehicle and detects a rotation state of wheels is known (see, for example, Patent Document 1).

  A rotation detection device for a vehicle described in Patent Document 1 includes a rotation detection IC that detects the number of rotations of a rotor interlocked with a wheel, and an external device such as an ABS (anti-lock brake system) that outputs a detection signal output from the rotation detection IC. And a housing that houses and protects the rotation detection IC.

  The rotation detection IC includes a detection unit having a detection element (Hall IC) and a processing circuit, and a lead unit that electrically connects the detection unit and the conductor of the insulated wire. The housing is formed by insert-molding a resin such as polyethylene terephthalate (PBT), for example, and has a bottomed cylindrical housing portion with one end opened, and a stay for attaching the vehicle rotation detection device to the vehicle. Yes. The detection unit of the rotation detection IC is disposed on the bottom surface side of the housing accommodating portion, and is disposed at a position facing the rotor in a state where the vehicle rotation detection device is attached to the vehicle.

JP 2012-68161 A

  In the vehicle rotation detection device disclosed in Patent Document 1, if there is a noise source such as a signal line or a control device that transmits a high-frequency signal around the detection element, the influence of noise (radiated electromagnetic field) from the noise source is reduced. The detection accuracy of the detection element may be reduced. For this reason, measures such as sufficiently increasing the distance between the detection element and the noise source or interposing a conductive shield member between the detection element and the noise source may be required. Or increased costs and weight.

  Accordingly, an object of the present invention is to provide an electronic module with a cable that can reduce the influence of an external magnetic field.

  In order to solve the above-mentioned problems, the present invention comprises a magnetic sensor for detecting magnetism formed by a magnetic source, a cable for transmitting a detection signal of the magnetic sensor, and a non-magnetic material. A first holding member for holding the sensor; and a second holding member configured to hold the first holding member by dispersing a magnetic material in a non-magnetic material, wherein the second holding member is the magnetic source And an electronic module with a cable that holds the first holding member except at least a part of a region between the magnetic sensor and the magnetic sensor.

  The electronic module with cable according to the present invention can reduce the influence of an external magnetic field.

(A) is sectional drawing which shows the structural example of the wheel bearing apparatus by which the sensor module which concerns on embodiment of this invention was used, and its periphery part. (B) is a top view which shows the structural example of the magnetic encoder of a rotation detection apparatus. The sensor module is shown, (a) is a front view, (b) is a bottom view, and (c) is a right side view. It is the sectional view on the AA line of FIG.2 (b). FIG. 4 is a sectional view taken along line BB in FIG. 3.

[Embodiment]
In the present embodiment, a case where the electronic module with cable of the present invention is used in a rotation detection device of a wheel bearing device mounted on a vehicle will be described.

  Fig.1 (a) is sectional drawing which shows the structural example of the wheel bearing apparatus 1 with which the sensor module which concerns on embodiment of this invention was used, and its peripheral part. FIG. 1B is a plan view illustrating a configuration example of the magnetic encoder 6 of the rotation detection device 10.

(Configuration of wheel bearing device 1)
The wheel bearing device 1 includes an inner ring 11 having a cylindrical main body part 111 and a flange part 112 to which a wheel (not shown) is attached, an outer ring 12 disposed on the outer peripheral side of the main body part 111 of the inner ring 11, an inner ring 11 and an outer ring. A plurality of rolling elements 13 disposed between the inner ring 11 and the rotation detecting device 10 for detecting a rotation speed of the inner ring 11 relative to the outer ring 12.

  A spline fitting portion 111 a for connecting a drive shaft (not shown) along the rotation axis O is formed on the inner periphery of the main body 111 of the inner ring 11. A plurality of through holes 112a into which bolts (not shown) for attaching the wheels are press-fitted are formed in the flange portion 112 of the inner ring 11.

  The outer ring 12 is formed in a cylindrical shape, and is fixed to a knuckle 4 connected to the vehicle body via a suspension device (not shown) by a plurality of bolts 40 (only one is shown in FIG. 1). The knuckle 4 is formed with a through hole 4a for attaching a sensor module 2 described later. The sensor module 2 is fixed to the knuckle 4 with bolts 41.

  An annular space between the inner ring 11 and the outer ring 12 is sealed by the first seal member 14 and the second seal member 15 including the metal core 151 and the elastic member 152. The first seal member 14 is disposed on the flange portion 112 side of the inner ring 11, and the second seal member 15 is disposed on the opposite side (vehicle body side) from the flange portion 112.

  The metal core 151 of the second seal member 15 includes a mounting plate 151 a to which the elastic member 152 is attached, and a side wall 151 b that is press-fitted between the outer ring 12 and the knuckle 4. The cross section formed by the mounting plate 151a and the side wall 151b is L-shaped. The elastic member 152 is bonded to the mounting plate 151a of the cored bar 151 by vulcanization bonding.

(Configuration of the rotation detection device 10)
The rotation detection device 10 includes a magnetic encoder 6 as a magnetic generation source fixed to the outer peripheral surface 111 b of the main body 111 of the inner ring 11, and a sensor module 2 that detects magnetism generated as the magnetic encoder 6 rotates. doing. The sensor module 2 is an aspect of the electronic module with cable of the present invention.

  As shown in FIG. 1B, the magnetic encoder 6 has a plurality of N poles 61 and a plurality of S poles 62 arranged alternately along the circumferential direction. Further, a cover member 16 that suppresses adhesion of foreign matter to the magnetic encoder 6 is provided at an end of the outer peripheral surface 111b of the main body 111 of the inner ring 11 on the vehicle body side (the side opposite to the flange portion 112).

  The magnetic encoder 6 rotates around the rotation axis O together with the inner ring 11, and the magnetic pole (N pole 61 or S pole 62) of the portion facing the sensor module 2 changes with the rotation of the inner ring 11. The sensor module 2 detects this magnetic pole change, that is, the strength of the magnetic field formed by the magnetic encoder 6. The intensity of the magnetic field detected by the sensor module 2 is converted into, for example, a high-frequency signal and transmitted to an external device such as ABS (anti-lock brake system) via the cable 30. The change in the magnetic field formed by the magnetic encoder 6 corresponds to the rotation of the wheel attached to the flange portion 112 of the inner ring 11.

(Configuration of sensor module 2)
2A and 2B show the sensor module 2, wherein FIG. 2A is a front view, FIG. 2B is a bottom view, and FIG. 2C is a right side view.

  The sensor module 2 includes a later-described magnetic sensor 31, a cable 30 that transmits a detection signal of the magnetic sensor 31, and a housing 20 that houses a part of the cable 30 and the magnetic sensor 31.

  The housing 20 includes a shaft-shaped main body portion 201, a cable holding portion 203 formed along the lead-out direction of the cable 30, and an attachment portion 204 attached to the knuckle 4 (see FIG. 1). As shown in FIG. 2B, the attachment portion 204 is formed with a bolt insertion hole 204a through which the bolt 41 (see FIG. 1) is inserted.

  The main body 201 is composed of a first shaft portion 201a, a second shaft portion 201b, a third shaft portion 201c, and a fourth shaft portion 201d that have different radial dimensions. The radial dimensions of the first shaft portion 201a, the second shaft portion 201b, the third shaft portion 201c, and the fourth shaft portion 201d are the first shaft portion 201a, the second shaft portion 201b, the third shaft portion 201c, and The fourth shaft portion 201d is formed larger in order.

  As shown in FIG. 2A, the cable 30 is led out from the end portion of the cable holding portion 203 in the direction intersecting the axial direction of the main body portion 201. As shown in FIG. 2C, the cable 30 includes a plurality (three in the present embodiment) of insulated wires 301 and a tubular sheath 302 that collectively covers the plurality of insulated wires 301. .

  FIG. 3 is a cross-sectional view taken along line AA in FIG. 4 is a cross-sectional view taken along line BB in FIG.

  The magnetic sensor 31 includes a sensor body 311 including a pair of detection elements 311a (only one is shown in FIG. 3) that detects the strength of the magnetic field formed by the magnetic encoder 6 (see FIG. 1A), and a sensor body. And a plurality of lead wires 312 led out from the portion 311. In FIG. 3, only one lead wire 312 arranged on the most front side among the plurality of lead wires 312 is shown.

  The detection element 311 a is electrically connected to the lead wire 312 inside the sensor main body 311. In the present embodiment, the detection element 311a is a Hall element, and detects the intensity of a magnetic field that changes as the wheel rotates (a magnetic field that changes as the magnetic pole of the magnetic encoder 6 changes). In FIG. 3, the detection element 311 a sealed inside the sensor main body 311 is indicated by a broken line.

  In the cable 30, a plurality of insulated wires 301 are exposed from the sheath 302 inside the housing 20. In FIG. 3, only one insulated wire 301 arranged on the most front side among the plurality of insulated wires 301 is shown. The sheath 302 contains a magnetic material. More specifically, the sheath 302 is formed by mixing a metal powder such as iron or a metal fiber into a resin such as vinyl chloride.

  The insulated wire 301 has a center conductor 301a and an insulator 301b that covers the center conductor 301a. The center conductor 301a is connected to the lead wire 312 of the magnetic sensor 31 at the tip portion by, for example, welding or soldering.

  The magnetic field of the magnetic encoder 6 (see FIG. 1A) detected by the detection element 311a is converted into a detection signal in the sensor body 311 and transmitted to the external device via the lead wire 312 and the cable 30. The

  As shown in FIG. 3, the housing 20 includes a primary molded body 21, a secondary molded body 22, a tertiary molded body 23, and a case member 24.

  The primary molded body 21 is an aspect of the first holding member of the present invention that holds the magnetic sensor 31 and is made of a nonmagnetic material. In the present embodiment, the primary molded body 21 is made of resin, and is molded including the magnetic sensor 31 and the end of the insulated wire 301 in which the central conductor 301a is connected to the lead wire 312 of the magnetic sensor 31. ing. As for the magnetic sensor 31, the whole sensor main-body part 311 is covered with the primary molding body 21. FIG.

  The insulated wire 301 is fixed along the extending direction of the lead wire 312 inside the primary molded body 21. In the primary molded body 21, a first lead-out portion 21 a for leading out the insulated wire 301 is formed on the side opposite to the magnetic sensor 31.

  The case member 24 is made of, for example, a resin formed by injection molding, and is formed in a bottomed cylindrical shape that covers an end portion of the primary molded body 21 on the side where the magnetic sensor 31 is disposed. A magnetic encoder 6 (see FIG. 1A) is disposed on the bottom surface side of the case member 24.

  The secondary mold molded body 22 and the tertiary mold molded body 23 are one mode of the second holding member of the present invention that holds the primary mold molded body 21, and are configured by dispersing a magnetic body in a non-magnetic body. The ratio of the volume of the magnetic body to the volume of the secondary mold body 22 and the tertiary mold body 23 is preferably 40 to 97%.

  In the present embodiment, the secondary mold molded body 22 and the tertiary mold molded body 23 are formed by dispersing metal powder such as iron or metal fiber in a resin. Therefore, the secondary mold molded body 22 and the tertiary mold molded body 23 have a shielding function. In addition, the primary mold molded body 21 does not contain a magnetic body.

  The secondary mold molded body 22 and the tertiary mold molded body 23 hold the primary mold molded body 21 except at least a part of the region between the magnetic encoder 6 and the magnetic sensor 31. In the present embodiment, the secondary molded body 22 and the tertiary molded body 23 hold the primary molded body 21 except for the entire area between the magnetic encoder 6 and the magnetic sensor 31. That is, in the present embodiment, the secondary molded product 22 and the tertiary molded product 23 are not interposed between the magnetic encoder 6 and the magnetic sensor 31.

  More specifically, the secondary molded body 22 includes an end on the opening side (the side opposite to the detection element 311 a), the primary molded body 21 exposed from the case member 24, and the insulated wire 301 of the cable 30. It is molded including the end portion on the exposed portion side. In addition, the secondary molded body 22 has a second lead-out portion 22a formed on the side opposite to the first lead-out portion 21a with the insulated wire 301 led out from the first lead-out portion 21a of the primary mold-molded body 21. Is derived from

  More specifically, the tertiary molded body 23 is molded so as to cover the outer surface including the second lead-out portion 22a of the secondary molded body 22, and constitutes the cable holding portion 203 and the mounting portion 204 of the housing 20. ing. The tertiary molded body 23 is fixed in a state where the cable 30 is bent in a direction intersecting with a direction parallel to the longitudinal direction (extension direction) of the lead wire 312 of the magnetic sensor 31.

  The mounting portion 204 is provided with a cylindrical collar 204b made of a metal such as aluminum molded in the tertiary molded body 23, and a through hole of the collar 204b serves as a bolt insertion hole 204a.

  As shown in FIG. 4, the outer side of the primary mold molded body 21 is covered with the secondary mold molded body 22, and the secondary mold molded body 22 is covered with the tertiary mold molded body 23. The primary molded body 21 for molding the magnetic sensor 31 is formed only from a resin that is a non-magnetic material, and the outside is dispersed with a metal powder or metal fiber that is a magnetic material in a resin that is a non-magnetic material. Further molding is performed by the secondary mold molded body 22 and the tertiary mold molded body 23 configured.

  The first shaft portion 201 a and the second shaft portion 201 b in the main body portion 201 of the housing 20 are configured by the primary mold body 21 and the case member 24. The third shaft portion 201 c in the main body portion 201 is configured by the primary mold molded body 21, the secondary mold molded body 22, and the case member 24. The fourth shaft portion 201 d in the main body 201 is constituted by a primary mold molded body 21, a secondary mold molded body 22, and a tertiary mold molded body 23.

(Operation and effect of the embodiment)
According to the embodiment described above, the following operations and effects can be obtained.

(1) The primary molded body 21 that holds the magnetic sensor 31 is a metal powder or metal fiber that is a magnetic substance in a resin that is a non-magnetic substance except at least a part of the area between the magnetic encoder 6 Are held by the secondary mold molded body 22 and the tertiary mold molded body 23 configured by dispersing the magnetic field, etc., so that the magnetic effect due to the shielding effect of the magnetic material dispersed in the secondary mold molded body 22 and the tertiary mold molded body 23 The magnetic field generated from an external device such as a control device provided outside the wheel bearing device 1 is generated by the secondary mold molded body 22 and the tertiary mold molded body 23 while suppressing a decrease in detection accuracy of the magnetic field strength of the encoder 6. It is possible to shield. Thereby, the influence of the magnetic field from the outside on the magnetic sensor 31 can be reduced, which leads to suppression of malfunction in the magnetic sensor 31.

(2) Since the primary molded body 21 is composed only of a resin that is a non-magnetic material, the strength of the magnetic field accompanying the rotation of the magnetic encoder 6 can be reduced without shielding the magnetic field formed by the magnetic encoder 6. The change can be reliably detected by the detection element 311a.

(3) Since the secondary mold molded body 22 and the tertiary mold molded body 23 are configured by dispersing metal powder, metal fibers, etc., which are magnetic materials, in a resin, which is a non-magnetic material, Generation of noise in the high-frequency signal used for the detection signal can be shielded by the secondary mold body 22 and the tertiary mold body 23.

(4) Since the sheath 302 of the cable 30 contains a magnetic material such as metal powder or metal fiber, the shield function in the sensor module 2 is further improved.

(Summary of embodiment)
Next, the technical idea grasped from the embodiment described above will be described with reference to the reference numerals in the embodiment. However, the reference numerals and the like in the following description are not intended to limit the constituent elements in the claims to the members and the like specifically shown in the embodiments.

[1] A magnetic sensor (31) for detecting magnetism formed by a magnetic generation source (magnetic encoder 6), a cable (30) for transmitting a detection signal of the magnetic sensor (31), and a nonmagnetic material. A first holding member (primary molding body 21) that holds the magnetic sensor (31) and a second holding member (secondary body) that holds the primary molding body (21) by dispersing the magnetic body in a non-magnetic body. A secondary mold molded body 22 and a tertiary mold molded body 23), and the secondary mold molded body 22 and the tertiary mold molded body 23 are regions between the magnetic encoder 6 and the magnetic sensor 31. An electronic module with a cable (sensor module 2) holding the primary molded body (21) except for at least a part thereof.

[2] The sensor module (2) according to [1], wherein the primary mold molded body (21), the secondary mold molded body (22), and the tertiary mold molded body (23) are molded molded bodies. ).

[3] The sensor module (2) according to [1] or [2], wherein the ratio of the volume of the magnetic body to the volume of the secondary mold molded body 22 and the tertiary mold molded body 23 is 40 to 97%.

[4] The cable (30) includes a central conductor (301a) and an insulated wire (301) having an insulator (301b) covering the central conductor (301a), and a sheath (302) covering the insulated wire (301). The sensor module (2) according to any one of [1] to [3], wherein the sheath (302) contains a magnetic substance.

  While the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

  The present invention can be appropriately modified and implemented without departing from the spirit of the present invention. For example, in the above-described embodiment, the sensor module 2 used in the rotation detection device of the wheel bearing device mounted on the vehicle has been described. is there. In this case, the case member or the like that directly holds the current sensor is made of a nonmagnetic material, and the housing or the like that covers the outside of the case member or the like is formed by dispersing the magnetic material in the nonmagnetic material.

  Moreover, in the said embodiment, although the tertiary mold molded object 23 was also comprised by disperse | distributing a magnetic body to a nonmagnetic body, the tertiary mold molded object 23 is comprised by disperse | distributing a magnetic body to a nonmagnetic body. It does not have to be. That is, it is only necessary that the secondary mold molding 22 covering at least the primary mold molding 21 is configured by dispersing a magnetic material in a non-magnetic material.

  Moreover, in the said embodiment, although the outer side of the primary mold molded object 21 was covered with the secondary mold molded object 22 and the tertiary mold molded object 23, it is not restricted to this but only the secondary mold molded object 22 It may be covered, or the outer side of the tertiary molded body 23 may be covered with a molded body, a holding member, or the like.

DESCRIPTION OF SYMBOLS 1 ... Wheel bearing apparatus, 2 ... Sensor module (electronic module with a cable), 4 ... Knuckle, 4a ... Through-hole, 6 ... Magnetic encoder (magnetic source), 10 ... Rotation detection apparatus, 11 ... Inner ring, 12 ... Outer ring, DESCRIPTION OF SYMBOLS 13 ... Rolling body, 14, 15 ... Seal member, 16 ... Cover member, 20 ... Housing, 21 ... Primary molding body (1st holding member), 21a ... 1st derivation | leading-out part, 22 ... Secondary molding body ( (Second holding member), 22a ... second lead-out portion, 23 ... tertiary molded body (second holding member), 24 ... case member, 30 ... cable, 31 ... magnetic sensor, 40, 41 ... bolt, 61 ... N Pole, 62 ... S pole, 111 ... body part, 111a ... spline fitting part, 111b ... outer peripheral surface, 112 ... flange part, 112a ... through hole, 151 ... cored bar, 151a ... mounting plate, 151b ... side wall, 15 ... elastic member, 201 ... main body part, 201a ... first shaft part, 201b ... second shaft part, 201c ... third shaft part, 201d ... fourth shaft part, 203 ... cable holding part, 204 ... attachment part, 204a ... Bolt insertion hole, 204b ... collar, 301 ... insulated wire, 301a ... center conductor, 301b ... insulator, 302 ... sheath, 311 ... sensor body, 311a ... detection element, 312 ... lead wire, O ... rotation axis

Claims (4)

A magnetic sensor for detecting magnetism formed by a magnetic source;
A cable for transmitting a detection signal of the magnetic sensor;
A first holding member made of a non-magnetic material and holding the magnetic sensor;
A second holding member configured to disperse a magnetic material in a non-magnetic material and hold the first holding member;
The electronic module with a cable, wherein the second holding member holds the first holding member except for at least a part of a region between the magnetic generation source and the magnetic sensor. The first holding member and the second holding member are molded molded bodies that are molded.
The electronic module with a cable according to claim 1. The ratio of the volume of the magnetic body to the volume of the second holding member is 40 to 97%.
The electronic module with a cable according to claim 1 or 2. The cable is
An insulated wire having a central conductor and an insulator covering the central conductor;
A sheath covering the insulated wire,
The sheath contains a magnetic material,
The electronic module with a cable according to any one of claims 1 to 3.

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