JPH07101179B2 - Sensor built-in motor - Google Patents

Description

Description: “Prior Art” The present invention relates to a sensor built-in motor having a potentiometer for detecting rotational position.

"Prior Art and Problems Thereof" This type of motor is used, for example, for driving a seat slide device and detecting a movement position thereof in a vehicle-related manner. FIG. 3 is a conceptual diagram showing an example thereof, in which a pair of left and right seat tracks 11 are respectively fixed to the vehicle floor surface and a lower rail 12, which is slidable with respect to the lower rail 12 and fixed to the seat S. It consists of the upper rail 13 A rack 14 is integrally fixed to one upper rail 13, and a motor 20 having a pinion 21 that meshes with the rack 14 is fixed to the lower rail 12 or a member related thereto. Therefore, when the pinion 21 is rotated by the motor 20, the upper rail 13, that is, the seat S moves back and forth.

The motor 20 is, as shown in FIGS. 4 and 5, a rotary drive source.
A worm 23 rotatably driven by 22 is engaged with a worm wheel 24, and the pinion 21 is fixed to the tip of the output shaft 25 of the shaft portion of the worm wheel 24.

A potentiometer 30 is located on the opposite side of the worm wheel 24 from the pinion 21. This potentiometer 30
Detects the amount of rotation of the worm wheel 24,
It detects the position of the upper rail 13, and is used, for example, to store an optimum seat position according to the driver. A rotary shaft 31 of the potentiometer 30 is orthogonal to the shaft of the worm wheel 24, and a bevel gear 32 is fixed to the tip of the rotary shaft 31. On the other hand, a bevel gear 26 that meshes with the bevel gear 32 is fixed to the worm wheel 24 of the motor 20.

As is apparent from FIG. 5, the bevel gear 26 is integrally provided on a disc 27 which is separate from the worm wheel 24, and the disc 27 has an eccentric position on the opposite side of the bevel gear 26. In addition, a plurality of fixing pins 28 are projected. The fixing pin 28 is fitted into a fixing hole 29 formed in the worm wheel 24, so that the bevel gear 26 rotates integrally with the worm wheel 24.

However, this conventional device requires the bevel gears 26 and 32 in order to transmit the rotation of the worm wheel 24 to the potentiometer 30. For this reason, the entire thickness becomes large, and it is difficult to use it in a place where there is not enough space. In FIG. 5, the thickness t is the potentiometer.
It is a space added to attach 30. Further, the bevel gears 26 and 32 are expensive gears, and an increase in cost is inevitable as a whole.

[Object of the Invention] The present invention solves the above problems of the conventional sensor built-in motor, and provides a sensor built-in motor that does not use a bevel gear and does not require much space for installing a potentiometer. With the goal. In particular, the present invention has an object of downsizing and thinning for use as a drive source of a seat slide device and a seat position detecting means thereof.

[Outline of the Invention] A sensor-incorporated motor according to the present invention includes a rotary drive source, a worm wheel that meshes with a worm that is rotationally driven by the rotary drive source, and an end surface of the worm wheel that has a smooth distance from the center of rotation. It has a spiral guide formed by changing it and a rotation axis parallel to the rotation axis of the worm wheel,
A rotary potentiometer arranged outside the worm wheel, a sensor arm arranged to face a spiral guide forming end surface of the worm wheel, and one end of which is fixed to a rotary shaft of the rotary potentiometer, and a sensor arm of the sensor arm. A sensor member that engages with the spiral guide of the worm wheel provided at the other end is provided.

"Examples of the Invention" The present invention will be described below with reference to illustrated examples. 1 and 2 show an embodiment of the present invention, in which the same elements as those of the conventional apparatus are designated by the same reference numerals. The potentiometer used in the present invention is a rotary potentiometer 40 having a rotary shaft.
The output changes when 41 rotates. This rotary potentiometer 40 has a casing 46 outside the worm wheel 24,
The rotation shaft 41 is fixed in parallel with the axis of the output shaft 25. The rotary shaft 41 includes an output shaft 25 of the worm wheel 24.
One end of a sensor arm 42 extending on the opposite end face is fixed.

On the other hand, on the worm wheel 24, a spiral groove 43 is formed on the surface on the sensor arm 42 side. The spiral groove 43 is formed by gradually and smoothly changing the distance from the rotation center of the worm wheel 24, and the sensor member 44 fixed to the free end of the sensor arm 42 is fitted in the spiral groove 43. .

In the present apparatus having the above-described structure, the worm 23 is rotated by the rotary drive source 22.
Drive and rotate the worm wheel 24, the output shaft 25
The pinion 21 rotates with. Therefore, in the example of FIG. 3, the upper rail 13 (seat S) can be moved back and forth via the rack 14 as in the conventional apparatus.

On the other hand, when the worm wheel 24 rotates, the sensor arm 42 in which the sensor member 44 at the tip is fitted in the spiral groove 43 swings,
The rotating shaft 41 is rotated. As a result, the output of the rotary potentiometer 40 changes, and from this change in output, the worm wheel
It is possible to detect the rotational position of 24, that is, the position of the upper rail 13 (seat S) in the front-rear direction in the example of FIG.

The sensor built-in motor of the present invention, in addition to the above-described basic functions of driving and rotational position detection, the sensor arm 42 is arranged to face the spiral groove 43 of the worm wheel 24, and the rotary potentiometer 40 is , This warm foil
Since it is arranged outside of 24, the axial dimension of the worm wheel 24 does not increase due to the rotational position detection mechanism, and it is possible to achieve thinning and miniaturization.

[Advantages of the Invention] As described above, according to the present invention, a worm wheel used for extracting power from a rotary drive source is used, and a spiral guide is provided on the end surface of the worm wheel. The sensor arms are arranged so as to face each other, and a sensor unit that engages with the spiral guide is provided at one end of the sensor arm,
Since the other end is fixed to the rotary shaft of the rotary potentiometer provided outside the worm wheel, a small and thin sensor built-in motor having a small axial dimension of the worm wheel can be obtained. Therefore, it is suitable for use, for example, for detecting the drive source and the seat position of a seat slide device that is required to be thin and small. Further, unlike the conventional device, an expensive bevel gear is not used, so that the number of parts can be reduced, the cost can be reduced, and the weight and the size can be reduced. Further, according to the rotary potentiometer, the installation position does not have to be on the worm wheel, and thus the installation position can be freely adjusted.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a sensor built-in motor of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a usage example of a sensor built-in motor having a potentiometer. FIG. 4 is a side view of the seat slide device illustrated as FIG. 4, FIG. 4 is a plan view of a conventional sensor built-in motor, and FIG. 5 is XI- of FIG.
It is sectional drawing which follows the XI line. 22 …… Rotary drive source, 25 …… Output shaft, 24 …… Warm wheel, 40 …… Rotary potentiometer, 42 …… Sensor arm, 43 …… Spiral groove, 44 …… Sensor member.

Claims (1)

[Claims] 1. A rotary drive source; a worm wheel meshing with a worm that is rotationally driven by the rotary drive source; a spiral guide formed on an end face of the worm wheel by smoothly changing a distance from a rotation center; A rotary potentiometer having a rotation axis parallel to the rotation axis of the worm wheel and arranged outside the worm wheel; arranged so as to face the spiral guide forming end surface of the worm wheel, one end of which is the rotary potentiometer. A sensor arm fixed to the rotating shaft of the sensor arm; and a sensor member which is provided at the other end of the sensor arm and engages with the spiral guide of the worm wheel.