JP2002206910A - Rotation angle detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle detector used in the detection of a rotation angle in steering of an automobile and capable of reducing a detection error and facilitating processing of a detection circuit. SOLUTION: This rotation angle detector is constituted such that the travel of a moving body 13 in accordance with the rotation of a detection gear 12 meshing with a driving gear 1A of a rotary body 1 is detected as a gradually increasing or decreasing detection signal by a magnet 14 and a magnetism detection element 16 to detect a rotation angle of the rotary body 1 so as to reduce the detection error and facilitate arithmetic processing of the detection circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle detecting device used for detecting a rotation angle of a steering of an automobile.

[0002]

2. Description of the Related Art In recent years, as the functions of automobiles have become more sophisticated, those that detect the rotation angle of a steering by using various rotation angle detecting devices for various controls have been increasing.

Such a conventional rotation angle detecting device will be described with reference to FIGS.

FIG. 7 is a perspective view of a main part of a conventional rotation angle detecting device, and FIG. 8 is a sectional view of the same. In FIG. 7, reference numeral 1 denotes a rotating body having a driving gear 1A formed on the outer periphery.
A first detection gear 2 and a second detection gear 3 having different numbers of teeth mesh with each other.

[0005] The number of teeth of the first detection gear 2 and the second detection gear 3 is determined by a predetermined rotation angle of the rotating body 1, for example, a position where the rotating body 1 is rotated left two times from the neutral position, At the position rotated right two times, the number of teeth having periodicity at a fixed rotation angle is set so as to return to the initial meshing position.

The rotating body 1 is provided with an engaging portion 1B which engages with a shaft of a steering (not shown) inserted into a central portion, and a first detection gear 2 and a second detection gear 3
Are mounted with magnets 4 and 5, respectively.

[0007] A wiring board 6 is disposed on the upper surfaces of the first and second detection gears 2 and 3. At the same time, a detection circuit 9 composed of a microcomputer or the like for processing detection signals from the angle sensors 7 and 8 is formed to constitute a rotation angle detection device.

In the above arrangement, when the steering wheel is rotated, the rotating body 1 is rotated accordingly, and the first detection gear 2 and the second detection gear 3 meshed with the drive gear 1A are also rotated.

The rotation of the first detecting gear 2 and the second detecting gear 3 is detected by angle sensors 7 and 8 opposed to the magnets 4 and 5 mounted on the first detecting gear 2 and the second detecting gear 3, respectively. That is, the rotation angle of the steering is detected.

At this time, since the number of teeth of the first detection gear 2 and the number of teeth of the second detection gear 3 are different from each other, the detection signal shown in FIG.
As shown in the voltage waveform diagram of FIG. 9, in the range where the rotating body 1 makes two rotations to the left and two to the right, FIG.
9B and the phase of the angle sensor 8 in FIG. 9B have different voltage waveforms.

Then, as shown in the enlarged voltage waveform diagram of FIG. 10, from this phase difference, an arbitrary rotation angle θ of the rotating body 1 is determined by the voltage V1 of the angle sensor 7 and the angle sensor 8 at this time.
Is detected by the detection circuit 9 detecting the voltage V2 and calculating the voltage value and the number of teeth of the first detection gear 2 and the second detection gear 3. there were.

[0012]

However, in the conventional rotation angle detecting device, the rotation angle of the rotating body 1 is detected by the first detection gear 2 and the second detection gear 3 meshed therewith. Since the rotation of the two gears is detected and performed, especially at the start of the rotation operation or when reverse rotation is performed, the driving gear 1A of the rotating body 1, the first detection gear 2, and the second detection gear 3,
Due to the play of the two gaps, an error is likely to occur in the angle detection.
There was a problem that complicated arithmetic processing was required.

Further, when the range of the rotation angle to be detected becomes large, it is necessary to increase the number of teeth of each gear due to the periodic relationship between the rotating body 1 and the two detection gears. There was also a problem that it was difficult to achieve.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a rotation angle detection device which has a small detection error and which can easily perform a calculation process of a detection circuit.

[0015]

To achieve the above object, the present invention has the following arrangement.

According to the first aspect of the present invention, the detection means detects the movement of the moving body accompanying the rotation of the detection gear meshed with the driving gear of the rotating body as a detection signal which gradually increases or decreases. , The rotation angle detection device is configured to detect the rotation angle of the rotating body, and by one detecting means, and because the rotation angle of the rotating body is detected as a gradually increasing or decreasing detection signal, With a simple configuration, the rotation angle detecting device having a small detection error and easy calculation processing can be obtained.

According to a second aspect of the present invention, in the first aspect of the present invention, the detecting means is composed of a magnet and a magnetic detecting element. It has the effect of being able to.

According to a third aspect of the present invention, in the first aspect of the present invention, a conversion gear is provided, and a driving gear of a rotating body and a detection gear mesh with each other via the conversion gear. By changing the meshing direction of the gears, it is possible to easily change the moving direction of the moving body in accordance with the state in which the rotation angle detecting device is used, and to reduce the size and thickness of the device.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

The same components as those described in the section of the related art are denoted by the same reference numerals, and detailed description will be omitted.

(Embodiment) FIG. 1 is a perspective view of a main part of a rotation angle detecting device according to an embodiment of the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is an exploded perspective view thereof. Reference numeral 1 denotes a rotating body having a drive gear 1A formed on the outer periphery thereof, and a detection gear 12 having a shaft portion 12A extending downward at the center is meshed with the drive gear 1A.

A spiral screw 12B is formed on the shaft portion 12A of the detection gear 12, and a moving body 13 having a similar spiral screw formed in the inner hole 13A meshes with the spiral screw 12B so as to be able to move up and down. ing.

The rotating body 1 is provided with an engaging portion 1B which engages with a shaft of a steering (not shown) inserted into a central portion, and a magnet 14 is mounted on a side surface of the moving body 13. I have.

The wiring board 1 is located on the side of the moving body 13.
5 is disposed on the wiring board 15 at a position facing the side surface of the moving body 13, for example, a GMR
A magnetic detection element 16 such as an element (an antiparallel magnetic resistance element) is mounted, and a detection circuit 17 including a microcomputer or the like that processes a detection signal from the magnetic detection element 16 is formed.

Reference numeral 18 denotes a case made of an insulating resin;
Reference numeral 20 denotes a cover, which includes a rotating body 1, a detection gear 12, and a wiring board 1.
5 and the like are respectively positioned and accommodated by these to constitute a rotation angle detecting device.

In the above configuration, when the steering wheel is rotated, the rotating body 1 is rotated by this, and the detection gear 12 meshed with the driving gear 1A is rotated.
Moving body 13 in which inner hole 13A meshes with helical screw 12B of A
Moves up or down.

The number of teeth of the rotating body 1, the detection gear 12, the spiral screw 12B and the spiral screw of the inner hole 13A of the moving body 13 is determined by a predetermined rotation angle of the rotating body 1, for example, from the neutral position of the steering. The moving body 13 is set so as to move about 10 mm in the vertical direction when it makes three rotations in each of the left and right directions.

Then, by detecting the magnetism of the magnet 14 mounted on the moving body 13 by the magnetic detecting element 16, the rotation angle of the rotating body 1, that is, the steering rotation angle is detected.

At this time, the detection signal indicates the linear movement of the movable body 13 as shown in the voltage waveform diagram of FIG.
4 and the detecting means of the magnetic detecting element 16 detect the strength of the magnetic field, so that a linear voltage waveform gradually increases.

Then, from this linear voltage waveform, an arbitrary rotation angle θ of the rotating body 1 is detected as a voltage V, which is detected by the detection circuit 17 as the rotating angle of the rotating body 1, and the rotation of the steering wheel is detected. The angle is detected.

As described above, according to the present embodiment, the linear movement of the moving body 13 accompanying the rotation of the detection gear 12 is detected by the detection circuit 17 as a detection signal that gradually increases or decreases, and Since the rotation angle is detected, it is possible to obtain a rotation angle detection device having a simple configuration, a small detection error, and easy calculation processing of the detection circuit 17.

By providing the detecting means with the magnet 14 and the magnetic detecting element 16, it is possible to perform stable non-contact detection with a simple configuration.

In the above description, the shaft portion 12A of the detection gear 12 is extended downward, and the moving body 13 is meshed with the helical screw 12B so as to be vertically movable.
According to the state in which the rotation angle detecting device is used, as shown in the perspective view of the main part of FIG. However, implementation of the present invention is possible.

As shown in the perspective view of the main part of FIG. 6, a conversion gear 23 provided with two gears, a spur gear 23A and a bevel gear 23B, is provided. By meshing the drive gear 1A with the detection gear, for example, as shown in FIG.
The moving body 13 is meshed with the bevel gear portion 23B so that the moving body 13 moves laterally, or the spur gear portion 23A is meshed with the spur gear detection gear 12 as shown in FIG.
The moving direction of the moving body 13 can be easily changed in accordance with the state of use, such as a configuration in which the moving body moves vertically, and the rotation angle detecting device can be reduced in size and thickness.

In the above description, a spiral screw 12B is formed on the shaft portion 12A of the detection gear 12, and the spiral screw 12B is formed.
B and the inner hole 13A of the moving body 13
Although the moving body 13 is described as moving along with the rotation of 2, the spiral cam groove is formed on the outer periphery of the shaft portion 12A of the detection gear 12, and the projection provided on the moving body 13 moves within the cam groove. Accordingly, the present invention can be implemented by using other methods such as moving the moving body 13.

Further, the detecting means is constituted by the magnet 14 and the magnetic detecting element 16 and the movement of the moving body 13 is detected by magnetism. The unevenness and holes are provided, and the movement of the moving body 13 is detected by light using a photodetector mounted on the wiring board 15, or a resistor element is printed on the wiring board 15 and slid thereon. A configuration in which a brush or the like is attached to the movable body 13 and the movement of the movable body 13 is detected by a change in the resistance value of the resistor element may be adopted.

[0037]

As described above, according to the present invention, there is obtained an advantageous effect that it is possible to obtain a rotation angle detecting device which has a simple configuration, has a small detection error, and can be easily operated.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a rotation angle detecting device according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is an exploded perspective view of the same.

FIG. 4 is the same voltage waveform diagram.

FIG. 5 is a perspective view of a main part according to another embodiment.

FIG. 6 is a perspective view of the main part.

FIG. 7 is a perspective view of a main part of a conventional rotation angle detecting device.

FIG. 8 is a sectional view of the same.

FIG. 9 is a voltage waveform diagram of the same.

FIG. 10 is an enlarged voltage waveform chart of the same.

[Explanation of symbols]

 1, 21 Rotating body 1A, 21A Drive gear 1B Engagement part 12, 22 Detection gear 12A Shaft part 12B Helical screw 13 Moving body 13A Inner hole 14 Magnet 15 Wiring board 16 Magnetic detection element 17 Detection circuit 18 Case 19, 20 Cover 23 Conversion gear 23A Spur gear 23B Bevel gear

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiro Tateishi 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Kenhide Onishi 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference)

Claims (3)

[Claims] A rotating body having a driving gear formed on an outer periphery thereof;
A detection gear meshing with the drive gear, a moving body that moves with the rotation of the detection gear, and detection means for detecting the movement of the moving body, wherein the detection means gradually increases the movement of the moving body or A rotation angle detection device that detects the rotation angle of the rotating body by detecting the detection signal as a decreasing detection signal; 2. The rotation angle detecting device according to claim 1, wherein said detecting means comprises a magnet and a magnetic detecting element. 3. The rotation angle detecting device according to claim 1, wherein a conversion gear is provided, and a driving gear and a detection gear of the rotating body are meshed via the conversion gear.