JPH0633370Y2 - Rotation detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a rotation detection device, for example, a device effectively used for rotation detection in a drive device for a window regulator of an automobile.

[Conventional technology]

As a drive device for a window regulator of a vehicle such as an automobile, a motor as a drive source is provided with a worm gear reduction device as a reduction mechanism, and a rotation detection device for detecting rotation of the motor is provided. There is something.

As a rotation detecting device used in such a drive device for a window regulator, an object to be detected, which is arranged by partitioning a non-conductive portion and a conductive portion on the outer peripheral surface, is fixed to a motor shaft, and A pair of brushes as detectors are slidably contacted to the detected object, and the rotation of the motor is detected by turning on and off between the two brushes by the non-conductive part and the conductive part of the detected object. There is something.

An example of the object to be detected in the conventional rotation detecting device having such a structure is shown in FIG. The detected body 30 shown in FIG. 5 is a conductive portion 31 in which a thin plate made of a conductive material such as a copper alloy is formed into a substantially cylindrical shape having a C-shaped cross section by press working.
And a non-conductive portion 35 in which the conductive portion 31 is integrally insert-molded. That is, the cylindrical wall portion 32 of the conductive portion 31 is provided with one cutout portion 33 so as to extend in the axial direction, and a plurality of claw portions 34 are equally spaced in the circumferential direction on both end sides. It is arranged and cut and raised on the inside in the radial direction by pressing. Then, when the non-conductive portion 35 is integrally molded into a cylindrical shape, the conductive portion 31 is appropriately arranged in the cavity of the mold and integrally implanted.

[Problems to be solved by the device]

However, the rotation detecting device including such an object to be detected has the following problems.

(1) Since the cylindrical wall portion 32 of the conductive portion 31 is provided with the single cutout portion 33, the weight thereof is not uniform in the radial direction from the central portion of the conductive portion 31, and therefore is synchronized with the drive shaft. The rotating conductive part 31 becomes unbalanced, and it takes a certain amount of time to balance the conductive part 31 in the initial stage of rotation.

(2) When the conductive portion 31 is rotated, the cylindrical wall portion 32 has a predetermined width (an axial distance, although the brush as the detector comes into contact with the brush).
(Indicated by T ₁ in the figure) is required. On the other hand, since the tubular wall portion 32 of the conductive portion 31 is provided with the claw portion 34 group, a space (also T ₂ ) for providing the claw portion 34 group is required. Therefore, since two widths are required in the axial direction, the axial length T of the conductive portion 31 is inevitably long, the conductive portion occupies a large portion in the rotation detecting device, and a space for installing other equipment. Is restricted.

(3) Since the conductive portion 31 is formed into a tubular shape by pressing a plate-like body and then the work for forming the claw portions 34 is performed, the number of manufacturing steps of the conductive portion 31 increases.

The object of the present invention is to eliminate the rotational imbalance of the detected object in the rotation detection device, to shorten the axial length of the detected object, and to simplify the manufacturing process of the detected object. It is to provide a rotation detection device that can be realized.

[Means for Solving the Problems]

In the rotation detection device according to the present invention, a non-conductive portion and a conductive portion are arranged in the circumferential direction on the outer peripheral surface of a cylindrical object to be fixed to a rotation shaft, and the non-conductive portion and the conductive portion are arranged in the circumferential direction. In a rotation detection device in which a detector is in sliding contact with the outer peripheral surface, the conductive portion has an inner cylinder portion having an inner diameter into which the rotation shaft is fitted, and the inner cylinder portion is arranged concentrically with the inner cylinder portion, and A plurality of tubular wall portions each having a substantially arcuate cross-section and arranged at positions symmetrical with respect to the central axis, and a connecting portion that connects the inner tubular portion and the tubular wall portion are provided. The part is insert-molded to the non-conductive part, and the non-conductive part exposes the outer peripheral surface of the cylindrical wall part and is resin-molded to form the same outer peripheral surface as the cylindrical wall part. Is characterized by.

[Action]

According to the above-described means, the detected object is formed in a rotationally symmetrical shape with respect to the rotation axis center by both the conductive portion and the non-conductive portion, so that the rotation balance is maintained. Further, since the conductive portion is prevented from rotating with respect to the non-conductive portion at the plurality of cutout portions, it is not necessary to cut and raise the claw portion in the conductive portion for processing. Therefore, the step of forming the claw portion can be omitted, and the axial length of the conductive portion can be reduced by the claw portion.
That is, the total length of the rotation detecting device can be shortened.

〔Example〕

1 (a) and 1 (b) are a partially cut front view and a partially cut plan view showing a rotation detecting device according to an embodiment of the present invention, FIG. 2 is an external perspective view thereof, and FIG. FIG. 4 is a perspective view showing a conductive portion used, and FIG. 4 is a front sectional view showing a window regulator driving device in which the conductive portion is used.

In the present embodiment, a window regulator drive device including a rotation detection device according to the present invention includes a motor 1 as a drive source and a worm gear speed reducer 2 as a reduction mechanism, and a housing 3 of the motor 1 Is composed of a yoke 4 formed in a tubular shape with one end open, and an end bracket 5 covered with the opening of the yoke 4. On the inner circumference of the yoke 4, a plurality of magnets 6 constituting magnetic poles are fixedly arranged at equal intervals in the circumferential direction, and a rotating shaft 7 of the yoke 4 is concentrically arranged by bearings 8 and 9. It is rotatably supported. The rotating shaft 7 has an armature
10 is disposed so as to face the magnet 6, and is fixedly mounted on the outside. A commutator 11 is fixedly mounted on one side of the armature 10 on the rotary shaft 7. A pair of brushes 12 are attached to the end bracket 5 of the housing 3 in a brush holder.
The brushes 12 are held and mounted on 13, and both brushes 12 are configured to be slidably contacted to the commutator 11 by the biasing force of the brush spring 12A housed in the brush holder 13 to supply power to the armature 10. Further, a circuit breaker 14 is electrically connected to both brushes 12 so that the circuit is automatically cut off when a short circuit or a load larger than a design value is applied.

An object to be detected 15 described later is fixed to the rotating shaft 7 adjacent to the commutator 11, and one brush 16 as a detector is slidably contacted to the object to be detected 15. As will be described later, the brush 16 is electrically connected to the rotary shaft 7 via the conductive portion of the detected body 15, and the brush 16 and the rotary shaft 7 are connected by an electric circuit (not shown). It is designed to be connected to an external rotation determination device.

The worm gear speed reducer 2 includes a gear housing 17, and the gear housing 17 is integrally formed with the end bracket 5 of the motor housing 3. The rotating shaft 7 of the motor is inserted into the gear housing 17 via the end bracket 5. A worm 18 is provided on the outer periphery of the insertion portion of the motor rotation shaft 7 into the gear housing 17.
Are engraved integrally. An output shaft 19 of the worm gear reduction device 2 is rotatably supported by being inserted in a direction perpendicular to the rotary shaft 7 in a substantially central portion of the gear housing 17, and a worm wheel 20 is mounted on the output shaft 19 of the gear housing.
It is fixed inside 17. The worm wheel 20 is meshed with the worm 18 engraved on the rotary shaft 7. Therefore, the output shaft 19 is warmed by the rotary shaft 7 of the motor 1.
18, It is designed to be rotated at a reduced speed via the worm wheel 20. The output shaft 19 is interlocked with the drive shaft of the window regulator outside the gear housing 17, and the window regulator is driven by decelerating rotation of the rotary shaft.

The detected body 15 is provided with a conductive portion 21 as shown in FIG. 3, and this conductive portion 21 is a thin plate made of a conductive material such as a copper alloy or the like. , And the upper end) are integrally formed into a substantially cylindrical shape with a closed end. A pair of cutouts 22, 22 are arranged symmetrically around the axis on the cylindrical wall of the conductive portion 21 and cut in the same shape on the left and right. Therefore, the conductive portion 21 has a pair of cylindrical wall portions 23, 23 symmetrically arranged about the axis and formed in the same shape having a substantially arcuate cross section. An inner cylinder portion 26 is concentrically arranged on the upper end closing wall portion 24 of the conductive portion 21, and is integrally formed in a cylindrical shape having an inner diameter into which the rotary shaft 7 is press-fitted. Inner tube part 26
And a connecting portion that connects the cylindrical wall portions 23, 23 arranged at symmetrical positions with respect to the central axis of the inner cylindrical portion 26, respectively.
24 are formed substantially. In addition, a pair of through holes 25, 25 are formed in the connecting portion 24 on the outer side of the inner cylindrical portion 26 in a symmetrical manner.

The conductive portion 21 having such a shape is different from the non-conductive portion 27 in
It is insert-molded as shown in FIGS. 1 and 2. That is, the non-conductive portion 27 is formed with a cylindrical hollow portion 28 having a diameter slightly larger than the inner diameter of the inner tubular portion 26, and the gap between the outer side of the inner tubular portion 26 and the tubular wall portions 23, 23, The resin solid part 29 is molded in a cylindrical shape in a state where the molding resin wraps around the outer periphery of one end of the through holes 25, 25 and the cylindrical wall parts 23, 23. Therefore, in the circumferential direction of the detected body 15, the cylindrical wall portions 23, 23 made of the conductive portion 21 and the non-conductive portion 27 made of the mold resin are alternately arranged.

The to-be-detected body 15 thus configured is press-fitted and fixed to the rotary shaft 7 in a state of being adjacent to the commutator 11, as shown in FIG.

Next, the operation will be described.

When electric power is supplied to the armature 10 via the brush 12 and the commutator 11, the rotation shaft 7 is rotated by the rotation of the armature 10. The detected body 15 is rotated in synchronization with the rotation of the rotary shaft 7.

At this time, the brush 16 as a detector that is slidably contacted with the detection target 15 has a non-conductive portion 27 made of the molding resin of the detection target 15.
When it is in contact with, the detection target 15 and the brush 16 is turned off, and the brush 16 is in contact with either one of the cylindrical wall portions 23, 23 of the conductive portion 21 of the detection target 15, The two are turned on.

Then, when the on / off between the detected body 15 and the brush 16 is not continued, it is determined that the detected body 15 is not rotating and the motor is not rotating. On the contrary, when the on / off state between the detected body 15 and the brush 16 is continued, it is determined that the motor is rotating.

In such a rotation detection device, the conductive portion 21 has the cylindrical wall portion 23 and the inner cylindrical portion 26 formed by press bending and burring processing on a plate-shaped conductive material. Therefore, the conductive portion 21 can be manufactured only by press bending and burring, and the conductive portion 21 can be easily manufactured.

When the conductive portion 21 is insert-molded into the non-conductive portion 27, the mold resin wraps around the notches 22 and 22 of the cylindrical wall portions 23 and 23, and the inside and outside of the conductive portion 21 is filled with the resin made of the mold resin. It is in a state of being adjacent to the real part 29. Therefore,
A portion of the conductive portion 21 except the outer peripheral surface of the area where the brush 16 is in sliding contact is in a state of being adhered to or embedded in the molded resin solid portion 29, so that the conductive portion 21 and the molding resin are firmly fixed to each other.

Further, since the outer peripheral surface of the conductive portion 21 is not provided with a claw portion or the like for fixing the conductive portion 21 to the solid portion 29 of the molding resin, the outer peripheral surface of the conductive portion 21 has an axial direction in FIG. The area indicated by the length T ₃ is the area where the brush 16 can slide. Therefore, the axial length of the conductive portion 21 can be relatively shortened. As a result, a sufficient installation space for other devices installed near the object to be detected 15 can be secured.

Further, since the conductive part 21 and the non-conductive part 27 are arranged in the detected object 15 so as to have a rotationally symmetrical shape, the detected object 15
The balance when rotating 15 is extremely good.

Further, the brush 16 is a cylindrical wall portion of the conductive portion 21 in the detected body 15.
The brush 16 is sufficient because it is electrically connected to the rotating shaft 7 via the 23, the connecting portion 24, and the inner tubular portion 26. As a result, compared to the case of the conventional example in which a pair of brushes are installed,
Since the space around the detection body can be given a margin, the degree of freedom in designing the motor can be increased, and further,
Since the number of parts can be reduced by omitting one brush and its electrical wiring, the device can be simplified.

Needless to say, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

For example, the cylindrical wall portions 23, 23 in the conductive portion may be rotationally symmetrical, and the number is not limited to a pair, and three or more wall portions having the same shape may be provided at symmetrical positions with respect to the rotation axis.

[Effect of device]

As described above, according to the present invention, the object to be detected comprises the conductive part and the non-conductive part made of the molding resin, and the conductive part and the non-conductive part are rotationally symmetrical with respect to the outer peripheral surface of the object. Therefore, the rotation balance of the detected object that rotates in synchronization with the rotation axis is improved. Also,
The conductive part of the object to be detected is manufactured by press-bending and burring a plate-like body, and it is possible to omit the claws and other parts to secure the fixing to the mold resin. It is possible to effectively utilize the entire length as a region where the brush slides, and it is possible to shorten the axial length of the conductive portion, and as a result, it is possible to sufficiently secure the installation space for other devices and the like.

Furthermore, by providing the inner cylinder portion, the brush can be attached to the cylinder wall portion,
Since the rotary shaft can be electrically connected via the connecting portion and the inner tubular portion, the number of brushes can be reduced to one. As a result, the space around the detector can be made larger, the degree of freedom in motor design can be increased, and the number of parts can be reduced by omitting one brush and its electrical wiring. Can be reduced, so that the device can be simplified.

[Brief description of drawings]

1 (a) and 1 (b) are a partially cut front view and a partially cut plan view showing a rotation detecting device according to an embodiment of the present invention, FIG. 2 is an external perspective view thereof, and FIG. FIG. 4 is a perspective view showing a conductive portion used, and FIG. 4 is a front sectional view showing a window regulator driving device in which the conductive portion is used. FIGS. 5 (a) and 5 (b) are a partially cut front view and a plan sectional view showing an object to be detected in a conventional rotation detecting device. 1 ... Motor, 2 ... Worm gear reducer, 3 ... Motor housing, 4 ... Yoke, 5 ... End bracket, 6 ... Magnet, 7 ... Rotating shaft, 8, 9 ... Bearing, 10 ... … Armature, 11 …… Commutator, 12 …… Brush, 13 …… Brush holder, 14 …… Circuit breaker, 15 …… Detected object, 16 …… Brush (detector), 17 ……
Gear housing, 18 ... Worm, 19 ... Output shaft, 20 ...
… Worm wheel, 21 …… Conductive part, 22 …… Notched part, 23
...... Cylinder wall part, 24 ...... connecting part, 25 ...... through hole, 26 ...... inner cylinder part, 27 …… non-conductive part, 28 …… hollow part, 29 …… resin solid part.

Claims (1)

[Scope of utility model registration request] 1. A non-conductive portion and a conductive portion are arranged in a circumferential direction on the outer peripheral surface of a cylindrical object to be fixed to a rotary shaft, and the non-conductive portion and the conductive portion are arranged on the outer peripheral surface of the object to be detected. In the rotation detecting device in which the child is in sliding contact, the conductive portion has an inner cylinder portion having an inner diameter into which the rotation shaft is inserted, and the inner cylinder portion is arranged concentrically with the inner cylinder portion, and with respect to the central axis thereof. And a plurality of cylindrical wall portions each having a substantially arcuate cross section and arranged at symmetrical positions, and a connecting portion connecting the inner cylindrical portion and the cylindrical wall portion, and the conductive portion is not The conductive portion is insert-molded, and the non-conductive portion is resin-molded so as to expose the outer peripheral surface of the cylindrical wall portion and to form the same outer peripheral surface as the cylindrical wall portion. Rotation detection device.