WO2018079471A1

WO2018079471A1 - Angle detecting device

Info

Publication number: WO2018079471A1
Application number: PCT/JP2017/038150
Authority: WO
Inventors: 小池　孝誌; 靖之福島; 裕也山口
Original assignee: Ntn株式会社
Priority date: 2016-10-31
Filing date: 2017-10-23
Publication date: 2018-05-03
Also published as: JP2018072192A

Abstract

Provided is an angle detecting device with which it is possible for an electrical circuit board to be secured without performing resin molding, which is simple to manufacture, and with which assembly time and manufacturing costs can be reduced. A magnetic encoder (8) having a magnetic track in which N poles and S poles are arranged alternately is secured to a rotating wheel (2) of a rolling bearing (7). An electrical circuit board (14) on which a magnetic sensor (13) is mounted is secured to a fixed wheel (2) of the rolling bearing (7) in such a way that the magnetic sensor (13) is disposed in a position facing a magnetic track member (10) of the magnetic encoder (8) across a gap. The electrical circuit board (14) is secured by means of a fixture such as screws or another threaded member, or by means of an adhesive, to a sensor housing (12) supported integrally with the fixed wheel (2).

Description

Angle detector

Related applications

This application claims the priority of Japanese Patent Application No. 2016-212743 filed on Oct. 31, 2016, which is incorporated herein by reference in its entirety.

The present invention relates to an angle detection device capable of detecting a rotation angle, for example, a technique applied to an angle detection device capable of high-resolution output or absolute angle detection.

In a bearing with a rotation sensor disclosed in Patent Document 1, a plastic film (flexible substrate) mounted on a rotating sensor fitted to an inner ring of a rolling bearing and an annular sensor housing fixed to a core metal fitted to an outer ring. The detection elements on the electric circuit board formed in (1) are arranged so as to face each other in close proximity. The rotation detection device and the bearing with the rotation detection device disclosed in Patent Document 2 include two magnetic encoders having different numbers of magnetic poles and two magnetic sensors for detecting the magnetic fields, and the absolute angle is determined from the phase difference between them. Is detected.

In the bearing with the rotation detection device, in which the rotation detection device is applied to the bearing, two magnetic encoders are arranged in the rotation axis direction on the outer diameter surface of the ring-shaped metal core that is press-fitted into the outer diameter surface of one end surface of the inner ring. Arranged side by side. The two magnetic sensors are integrated as a sensor module together with a signal processing circuit, and are resin-molded in a state of being inserted inside a ring-shaped metal sensor housing. It is attached to the inner diameter surface.

JP 2004-125455 A Japanese Patent No. 5081553

The bearing with a rotation sensor disclosed in Patent Document 1 curves a film-like electric circuit board coated with polyimide resin to an inner circumferential surface of an arc-shaped groove provided in an annular sensor housing fixed to an outer ring. Is attached. However, it is difficult to fix the film-like electric circuit board, and generally, a resin mold is applied to flow and solidify the resin material. In addition, the film-like electric circuit board has a problem that the unit price is higher than that of the epoxy board. In the bearing with a rotation detection device disclosed in Patent Document 2, a signal processing circuit including two magnetic sensors is resin-molded and integrated as a sensor module, and then the inner diameter of one end portion of the outer ring via the sensor housing Attached to the surface.

In the resin molding process, a fluid resin material (for example, epoxy resin) is filled in the electric circuit board (signal processing circuit) and the gap around the electric circuit board (signal processing circuit). In addition, many man-hours such as a degassing step (evacuation) are required in the middle so that cavities and bubbles do not remain, and there is a problem that the assembly cost becomes high.

The present invention solves the above-described problems, and provides an angle detection device that can fix an electric circuit board without performing resin molding, is easy to manufacture, and can reduce assembly man-hours and manufacturing costs. The purpose is to provide.

In the angle detection device according to the present invention, a magnetic encoder having a magnetic track in which N poles and S poles are alternately arranged is fixed to a rotating wheel of a bearing, and magnetically positioned at a position facing the magnetic track of the magnetic encoder via a gap. An angle detection device in which an electric circuit board on which the magnetic sensor is mounted is fixed to a fixed ring of the bearing so that the sensor is disposed,
The electric circuit board is fixed to a sensor housing integrally supported with the fixed ring by a fixing element made of a fixing tool or an adhesive.

In this specification, the “fixing tool” means a part for fixing an object, for example, a shaft-like part that fits into a hole of a screw member, a rivet, a press-fit pin or the like and has a fixing action. Even if it exists, the clip etc. which pinch | interpose and show | play a fixing effect may be sufficient. Further, the angle detection device may detect the rotation speed by detecting the angle.

According to this configuration, since the electric circuit board is fixed by the fixing element, the electric circuit board can be fixed without performing resin molding, and the manufacture of the angle detection device is simple, and the number of assembly steps and the manufacturing cost are reduced. Is possible.

In this invention, the fixture may be a screw member. The “screw member” includes bolts, screws, nuts, and the like, as well as similar members. The fixing by the screw member can be fixed by a tightening operation by rotation, so that the fixing operation is simpler and can be detachably fixed. Therefore, in the case of fixing with a screw member, the replacement is easy even when the electric circuit board fails.

In this invention, the electric circuit board may be fixed to the sensor housing in a detachable manner. If the electric circuit board is fixed detachably without being limited to the screw member, the electric circuit board can be easily replaced even if it breaks down.

In the present invention, a flat surface perpendicular to the radial direction and a radial hole or groove communicating with the flat surface are formed on the outer peripheral surface of the annular sensor housing, and the circuit board is fixed to the flat surface. The magnetic sensor may face the magnetic track of the magnetic encoder through the hole or groove. In this case, the magnetic sensor may be housed in the hole or groove, or may be outside the hole or groove and face the hole or groove. When the electric circuit board is fixed to the flat surface provided on the outer peripheral surface of the sensor housing, the electric circuit board, particularly the position of the magnetic sensor can be stabilized and accurate detection can be performed. It is preferable in terms of durability.

In this invention, the electric circuit board may have a quadrangular shape, and may be disposed along the axial direction of the bearing, and the axial width of the electric circuit board may be equal to or less than the width dimension of the magnetic encoder. If the electric circuit board has a quadrangular shape and the axial width thereof is equal to or smaller than the width dimension of the magnetic encoder, the axial dimension of the angle detection device can be reduced, and the space can be saved.

In the present invention, the magnetic encoder has two magnetic tracks having different numbers of magnetic poles, and the magnetic sensor detects the two magnetic tracks and outputs a signal indicating an absolute angle of the rotating wheel. You may make it have. Even in such an angle detection device for detecting an absolute angle, the present invention can omit the resin molding step and can be provided at low cost.

Any combination of at least two configurations disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the invention.

The present invention will be understood more clearly from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in a plurality of drawings indicate the same or corresponding parts.

It is a longitudinal cross-sectional view of the angle detection apparatus which concerns on one Embodiment of this invention. It is the front view which looked at the same angle detection apparatus in the arrow II direction of FIG. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1. It is explanatory drawing which shows the modification of a magnetic sensor. It is sectional drawing of the angle detection apparatus which concerns on other embodiment of this invention. It is the front view which looked at the same angle detection apparatus in the arrow VI direction of FIG. It is sectional drawing of the angle detection apparatus which concerns on other embodiment of this invention. It is explanatory drawing of the magnetic pole of the magnetic encoder in the same angle detection apparatus.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of the angle detection device, FIG. 2 is a view taken in the direction of arrow II in FIG. 1, and FIG. In FIG. 3, the description of the metal ring 11 described later is omitted. This angle detection device 1 has an N pole and an S pole on the outer diameter surface of the end of the rotating wheel 2 in the rolling bearing 7 composed of the rotating wheel 2, the fixed wheel 3, the rolling element 4, the cage 5, and the seal 6. Alternately magnetized magnetic encoders 8 are fixed in a fitted state. In the illustrated example, the rotating wheel 2 is an inner ring and the fixed wheel 3 is an outer ring. Instead of the rolling bearing 7, a sliding bearing may be used.

The magnetic encoder 8 includes a cored bar 9 and a magnetic track member 10. The magnetic track member 10 is formed by integrally molding a cored bar 9 with a rubber kneaded with magnetic powder in a mold together with a cored bar 9 or by vulcanizing and bonding a plastic and magnetic powder mixed together. Thus, the N pole and the S pole are alternately magnetized in the circumferential direction.

An annular sensor housing 12 is concentrically attached to the metal ring 11 that is fixed in a fitted state on the inner diameter surface of the end portion of the fixed ring 3. As a material of the sensor housing 12, a resin may be used. As shown in FIG. 3, a flat surface 12a perpendicular to the radial direction and a radial hole 12b communicating with the flat surface 12a are formed on the outer peripheral surface of the sensor housing 12. A groove may be formed instead of the hole 12b. The electric circuit board 14 on which the magnetic sensor 13 is mounted is fixed to the flat surface 12a with the fixture 15 so that the magnetic sensor 13 is accommodated in the hole 12b. In this example, the fixture 15 is made of a screw that is a screw member. Fixing by the fixing tool 15 is performed on both sides of the electric circuit board 14. A screw hole (not shown) is machined in the flat surface 12a, and the fixture 15 made of the screw member is screwed into the screw hole. As shown in FIG. 1, when the electric circuit board 14 and the metal ring 11 interfere with each other, the notch 11a is provided in the metal ring 11 to avoid the interference.

The electrical circuit board 14 is obtained by mounting electrical components on, for example, a glass epoxy printed board, for example, having a quadrangular shape, and the connector 16 is mounted on the surface opposite to the mounting surface of the magnetic sensor 13. If the axial width of the electric circuit board 14 is set to be equal to or smaller than the width dimension of the magnetic encoder 8, the axial dimension of the angle detection device 1 can be reduced, and space saving is possible.

According to the angle detection device 1 of this configuration, since the electric circuit board 14 is fixed by the fixing member 15 made of a screw member, the conventional resin molding process is not required, the number of assembling steps is reduced, and the manufacturing cost is reduced. To do. Further, since the electric circuit board 14 is fixed by a fixing member 15 made of a screw member, the electric circuit board 14 can be easily replaced even when the electric circuit board 14 breaks down. When the magnetic encoder 8 and the electric circuit board 14 are arranged on one end surface of the rolling bearing 7, oil repellent and water repellent are provided so that no problem occurs even if the grease of the rolling bearing 7 adheres to the surface of the electric circuit board 14. A liquid repellent having an action may be applied to the surface of the electric circuit board 14 as well. Further, instead of the liquid repellent, an epoxy resin-based molding agent may be partially brushed.

In the angle detection device 1 of this embodiment, the magnetic sensor 13 outputs a pulse-shaped rectangular signal as the magnetic encoder 8 rotates. As the magnetic sensor 13, for example, the magnetic signal is electrically output as follows. It is also possible to use a signal that can be multiplied by 2 to obtain a high-resolution rectangular signal.

FIG. 4 shows an example of the magnetic sensor 33 that multiplies and obtains a high-resolution rectangular signal. The magnetic sensor 33 includes a sensor array including a plurality of individual

magnetic sensors

33a and 33b, and signal processing for generating an output signal capable of detecting the rotational speed and direction of the rotating wheel 2 from the outputs of the

magnetic sensors

33a and 33b. A sensor module in which the circuit 33c is included in one package is used. The magnetic sensor 33 according to the present embodiment outputs two-layer output signals of multiplied A phase and B phase. The electrical phase difference between the A-phase output signal and the B-phase output signal output from the magnetic sensor 33 is 90 degrees.

The signal processing circuit 33c can be programmed from the outside to set the resolution in accordance with the count multiplication or the magnetic pole width of the magnetic track of the magnetic track member 10. For example, even if the track magnetic pole width of the magnetic track member 10 is changed, the magnetic sensor 33 can be adjusted by programming, and can flexibly cope with a specification change.

In this embodiment, as the magnetic sensor 33 satisfying the above-mentioned high function, the MPS40S manufactured by NTN-SNR ROULEMENTS disclosed in Non-Patent Document 1 is employed, and the magnetic track member 10 is also formed correspondingly. ing.

FIG. 5 shows a cross-sectional view of an angle detection device 17 according to another embodiment of the present invention, and FIG. 6 shows a view taken along arrow VI of FIG. The configuration of the angle detection device 17 is the same as that of the angle detection device 1 shown in FIG. 1 except for the matters to be specifically described. However, the sensor housing 18 covers the rolling bearing 7 around the outer periphery of the fixed ring 3 as the outer ring. The metal ring 11 is omitted. Similar to the flat surface 12a, a flat surface 18a perpendicular to the radial direction and a radial hole 18b communicating with the flat surface 18a are formed on the outer peripheral surface of the sensor housing 18, and a magnetic field is formed in the hole 18b. The electric circuit board 14 on which the magnetic sensor 13 is mounted is fixed to the flat surface 18a with screws 15 so that the sensor 13 is accommodated. A groove may be provided instead of the hole 18b. As a material of the sensor housing 18, for example, a metal material (iron-based, aluminum-based, etc.) is used.

Also in this configuration, each operation and effect described in the previous embodiment can be obtained. Also in this embodiment, the magnetic sensor 33 capable of obtaining a high-resolution rectangular signal by multiplication as described with reference to FIG. 4 may be used.

FIG. 7 shows a sectional view of still another embodiment of the angle detection device, and FIG. 8 shows the magnetic encoder and the magnetic sensor. This embodiment is the same as the first embodiment except for the matters specifically described. The magnetic encoder 20 of the angle detection device 19 of this embodiment is composed of a magnetic track member 22 (first magnetic track 22a, second magnetic 22b) having a cored bar 21 and two rows of

magnetic tracks

22a, 22b. The magnetic track 22a and the second magnetic track 22b have different numbers of magnetic poles. For example, the first magnetic track 22a is magnetized with 32 pole pairs and the second magnetic track 22b is magnetized with 31 pole pairs. The magnetic sensor 13 detects the magnetic fluxes of the first magnetic track 22a and the second magnetic track 22b, and detects the absolute angle inside the magnetic sensor 13 using the difference between the one pole pair.

Specifically, the magnetic sensor 13 includes two individual magnetic sensors (not shown) constituting the

magnetic tracks

22a and 22b and a signal processing circuit (both not shown), and the signal processing circuit includes: For example, the absolute angle is calculated as follows. When the magnetic encoder 20 is rotated, a phase shift corresponding to one magnetic pole pair occurs in one rotation between the signals of the two individual magnetic sensors that detect these magnetic fields. The signal processing circuit (not shown) detects this phase difference by a phase difference detection unit, and calculates an absolute angle in one rotation section by an angle calculation unit based on the phase difference.

Even with such an angle detection device 19 capable of detecting an absolute angle, the electric circuit board 14 can be fixed with a fixture 15 such as a screw member, and the resin molding step can be omitted, so that it can be provided at low cost. An adhesive may be used instead of the fixture 15.

In each of the above-described embodiments, the electric circuit board 14 is fixed by the fixing member 15 such as a screw member. However, as the fixing member 15, a rivet or a pin may be used instead of the screw member. Instead of using or in combination with the fixing tool 15, it may be fixed by other fixing methods such as bonding with an adhesive.

As described above, the preferred embodiments have been described with reference to the drawings, but various additions, modifications, and deletions are possible without departing from the spirit of the present invention. Therefore, such a thing is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Angle detection apparatus 2 ... Rotating wheel 3 ... Fixed wheel 7 ... Rolling bearing 8 ... Magnetic encoder 9 ... Core metal 10 ... Magnetic track member 11 ... Metal ring 12 ... Sensor housing 12a ... Flat surface 12b ... Hole 13 ... Magnetic sensor 14 ... electric circuit board 15 ... fixture 17 ... angle detector 18 ... sensor housing 18a ... flat surface 18b ... hole 19 ... angle detector 20 ... magnetic encoder 22 ...

magnetic track members

22a and 22b ... magnetic track 33 ...

magnetic sensor

33a, 33b: Individual magnetic sensor 33c: Signal processing circuit

Claims

A magnetic encoder having a magnetic track in which N poles and S poles are alternately arranged is fixed to a rotating wheel of a bearing, and a magnetic sensor is disposed at a position facing the magnetic track of the magnetic encoder via a gap. An angle detection device in which an electric circuit board on which the magnetic sensor is mounted is fixed to a fixed ring of the bearing,
The electric circuit board is an angle detection device fixed to a sensor housing integrally supported with the fixed ring by a fixing tool or an adhesive.
2. The angle detection device according to claim 1, wherein the fixture is a screw member.
3. The angle detection device according to claim 1 or 2, wherein the electric circuit board is fixed to the sensor housing in a detachable manner.
4. The angle detection device according to claim 1, wherein an outer peripheral surface of the annular sensor housing is provided with a flat surface perpendicular to the radial direction and a radial direction communicating with the flat surface. An angle detection device in which a hole or a groove is formed, the circuit board is fixed to the flat surface, and the magnetic sensor faces the magnetic track of the magnetic encoder through the hole or groove.
5. The angle detection device according to claim 1, wherein the electric circuit board has a quadrangular shape and is disposed along an axial direction of the bearing, and an axial width of the electric circuit board. Is an angle detection device that is equal to or smaller than the width dimension of the magnetic encoder.
6. The angle detection device according to claim 1, wherein the magnetic encoder includes two magnetic tracks having different numbers of magnetic poles, and the magnetic sensor includes the two magnetic tracks. An angle detection device having a function of detecting and outputting a signal indicating an absolute angle of the rotating wheel.