JP2003247863A - Composite detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resolver which detects an absolute angle value, and has a simple structure in addition, in spite of being a brushless multipolar resolver. <P>SOLUTION: A brushless resolver which has a rotary transformer provided together and supplies the power of a rotor 5 by noncontact action, is provided with a circular surface to be detected 101 which is fixed to the end surface of the inside core 3 of the rotary transformer and is displaced from the center of the rotor 5, and two sensors 10A, 10B which are fixed to the outer core portion 4 of the rotary transformer so as to be opposed to the surface 101, and are separated by 90 degrees in the direction of rotation of the rotor 5. When the surface 101 rotates, one sensor 10A generates a sinusoidal wave of one period per rotation, and the other sensor 10B generates a cosine wave of one period per rotation. Along with the function of the brushless resolver, the resolver performs detection of an absolute angle of multiple rotation and detection of the direction of rotation. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a multi-revolution detector capable of detecting a high-resolution absolute angle in a multi-revolution detector composed of a brushless multi-pole resolver and a multi-rotation detector. .

[0002]

2. Description of the Related Art As a detector for detecting the rotational position of a rotary machine such as a motor, a brushless resolver has been well known in the past. The structure is as shown in FIG. 4, and is composed of a rotary transformer section, a rotor section, and a stator section that play a role of brushless. The rotary transformer section is composed of a rotary side inner core 3 and an inner coil 31, and a fixed side outer core 4 and an outer coil 41. The inner core 3 and the outer core 4 face each other in a radial direction with a minute gap therebetween. ing. When the alternating current is supplied from the input / output lead 7, the alternating voltage is applied to the inner coil 31 through the gap between the inner core 3 and the outer core 4.
The inner core 3 is fixed to the follow shaft 22, and the outer core 4 is fixed to the frame 8.
The rotor portion is composed of the rotor 5 and the rotor coil 51,
The rotor 5 is fixed to the follow shaft 22. The inner coil 31 and the rotor coil 51 are electrically connected inside. The stator portion is the stator 6
And a stator coil 61, and the stator 6 is fixed to the frame 8. The follow shaft 22 is fixed to the shaft 1 of the motor (not shown), and the frame 8 is fixed to the bracket 11 of the motor. Further, the rotor 5 and the stator 6 are opposed to each other in the radial direction via a small gap.

FIG. 5 shows a connection relationship between a brushless resolver, a control circuit for processing the signal, and a waveform of a detection signal. Brushless resolver 2 and control circuit 91
Are connected by an input / output lead 7, and the control circuit 91 outputs two signals of A3S channel and B3S channel. When the shaft 1 of the motor rotates, the rotor 5
The electromagnetic coupling state between the stator 6 and the stator 6 changes, and a voltage having a phase difference proportional to the rotation angle is induced in the stator coil 61. This phase difference is controlled by the control circuit 91 to generate a sine wave A
The 3S channel signal and the cosine wave B3S channel signal are extracted to obtain a position detection signal.

As resolver types, a 1X resolver capable of obtaining a sine wave signal of one cycle per revolution and n per revolution.
NX for obtaining (n = 2, 3, ...) Cycle sine wave
(Hereinafter referred to as multipole) Classified as a resolver. FIG. 5 shows an example of a multi-pole 3X resolver, showing that a sine wave of 3 cycles is output to the A3S channel and a cosine wave is output to the B3S channel for one rotation. 1X
Although the resolver can detect the absolute value angle within one rotation, the resolution can be increased only up to about 1000 divisions due to the limit of the assembly accuracy of the rotor portion and the stator portion, and the resolution is further increased. There is a problem that you cannot do it. The multi-pole resolver cannot detect the absolute angle within one rotation, but it can obtain the signal of n cycles in one rotation, so the resolution is n times (n × 1000 division).
Is obtained.

[0005]

However, when a brushless resolver is used for positioning the motor,
The motor generally makes multiple revolutions, and since one resolver is used, the absolute value angle of multiple revolutions cannot be detected. Then, it is mounted on a motor. These structures are disclosed in JP-A-59-1.
Although disclosed in publications such as No. 54319 “multi-rotation absolute encoder” and Japanese Patent No. 2733504 “multi-rotation position detector”, there is a problem that the structure of the resolver is complicated and the cost is increased. Therefore, gear life and noise generated from gears have become problems. Therefore, there has been a demand from the market for a resolver that is a brushless multi-pole resolver but that can detect an absolute angle and has a simple structure.

Therefore, the present invention has a simpler structure than the conventional resolver composed of a plurality of resolvers and gears.
It is an object of the present invention to provide a composite type detector capable of detecting absolute angles with high resolution and multiple rotations at low cost without reliability problems such as gear life.

[0007]

In order to solve the above-mentioned problems, the present invention is a brushless resolver which is provided with a rotary transformer and supplies electric power of a rotor in a non-contact manner. The brushless resolver is fixed to an end face of an inner core of the rotary transformer. And a disc that is 90 degrees apart in the rotation direction of the rotor, and is fixed to the outer core portion of the rotary transformer so as to face the disc, and the disc functions as a surface to be detected.
Two sensors, and when the disk rotates, the two
One of the two sensors produces a sine wave of one cycle per revolution while the other sensor produces one sine wave per revolution.
It is characterized by generating a cosine wave with a period, and detecting the absolute angle of multiple rotations and the direction of rotation together with the function of the brushless multipole resolver. Further, according to the present invention, the surface of the disc is formed with a reflecting portion that reflects light and a non-reflecting portion that does not reflect light, and the shape of the non-reflecting portion is an annular shape whose center is the rotor. The two sensors are eccentric from the center, and each of the two sensors includes a light emitting unit that emits light to apply light to the surface of the disc, and a light receiving unit that receives the light reflected by the surface of the disc. It has a feature. Further, according to the present invention, the disk is a magnet magnetized in a radial direction so that the inner and outer poles are different from each other, and the boundary between the inner and outer magnetic poles is a circle, and the center thereof is the center of the rotor. Is eccentric, and the two sensors are magnetic sensors. As described above, it is possible to provide a composite detector that has a simple structure, is low in cost, has no reliability problem such as gear life, and can detect absolute angles with high resolution in multiple rotations. is there.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the structure of the composite detector of the present invention. In this figure, what is different from FIG. 4 showing a conventional composite detector is only a part of an inner core 3 and an outer core 4 which constitute a rotary transformer, and multi-rotation and an absolute angle are detected in this part. A detector is added. A light reflection type sensor is attached as a detector for detecting multiple rotations and an absolute angle, and the reflection type sensor 10A,
10B and the reflector 101. Reflector 101
Is composed of an eccentric circular reflective track portion and a hatched non-reflective portion, and is attached to the inner core 3. The two reflective sensors 10A and 10B are arranged at an angle of 90 degrees in the rotation direction of the shaft 1. The reflection type sensors 10A and 10B are composed of a light emitting element and a light receiving element, and the light emitting element applies light to the reflection track portion and the light receiving element detects the reflected light. Since the reflection track portion has an eccentric circular shape, when the shaft rotates, the detection signal becomes an analog signal of one cycle per rotation according to the change of the reflected light. Therefore, by shaping this signal into a rectangular wave and counting the rectangular wave, it is possible to detect how many revolutions the shaft 1 of the motor has made. And two reflective sensors 10A,
Since 10B is arranged at an angle of 90 degrees, the rotation direction of the shaft 1 can also be detected. Also, 1
Since the rotation changes by one cycle, the absolute angle within one rotation can be detected. This indicates that it has the same function as the 1X resolver.

FIG. 2 is a diagram for explaining the connection relationship between the composite detector of the present invention, that is, the brushless resolver 2 and the control circuit 9, and the waveform of the output signal of the control circuit 9. The brushless resolver 2 and the reflection sensor are shown in FIG. It is shown that four signals are output when the signals detected by 10A and 10B are input to the control circuit 9 through the input / output lead 7.
Further, the relationship between each detection signal of the control circuit 9 and the phase is also shown. As the detection signals of the reflective sensors 10A and 10B of this embodiment, the same AS channel signal as that of the 1X resolver can be obtained, so if this signal is shaped into a rectangular wave and counted,
The number of rotations of the motor shaft 1 can be detected. In addition, since the BS channel signal can be obtained in the same way, the AS
When used in combination with the channel signal, the rotation direction can be detected. Since the AS channel signal and the BS channel signal change by one cycle per rotation, the absolute angle within one rotation can be detected, and it has the same function as the 1X resolver. In this way, if the multi-rotation and the absolute angle are detected by the reflective sensor and the multi-polar resolver performs the high-resolution angle detection, the multi-rotation high-resolution absolute value of the rotation angle can be detected. In this example,
Inner core of rotary transformer with reflective sensor and reflector 3
Since it can be easily attached to the outer core 4, the structure of the composite detector is simple and small, and the cost can be reduced. As a specific method of use, a power source of the control circuit 9 that outputs signals of the AS channel and the BS channel and a power source of a receiving circuit (not shown) that inputs the signals of the AS channel and the BS channel and counts multiple rotations are used. If a battery is used so that it can be energized at all times, it is possible to detect the amount of multi-revolution without being affected by a power failure of the commercial power supply. A method for constantly energizing the circuit of such a multi-rotation detecting unit is disclosed in Japanese Patent Publication No. 6-4.
No. 1853, "Multi-rotation type absolute value encoder", etc., and is applicable to the composite detector of the present invention.

Next, as an application modification of the present invention, a magnetic sensor can be used in place of the reflection type sensor shown in FIG. 1, so this configuration is shown in FIG. In an environment with oil mist or the like, the reliability of the light reflection type sensor becomes a problem, but if a magnetic sensor is used as in this application modification, that problem can be avoided and the same function as that of the above embodiment can be obtained. be able to. Compared with FIG. 1, FIG. 3 shows reflective sensors 10A and 1A.
Only 0B and the reflector 101 are different, and the rest are the same. A Hall element can be used for the magnetic sensors 11A and 11B as an example, and the inner core 3 is
The disk of the ferrite magnet 111 is attached.
The circular plate is magnetized in the radial direction to the inner diameter side, and the boundary between the N pole and the S pole of the magnetized magnetic pole is an eccentric circle as in the case of the light reflection type sensor. The magnetic poles (N and S poles) are magnetized. As the detection signal, an analog signal of one cycle per one rotation is obtained as in the light reflection type sensor. Since the inner core 3 is made of a magnetic material that constitutes a rotary transformer, it can also function as a yoke of the ferrite magnet 111.

[0011]

As described above, according to the present invention, in the combined detector composed of the brushless multipole resolver and the detector for detecting multiple rotations, the rotary transformer section of the brushless multipole resolver is used. Since the detection function that detects multiple rotations and absolute angles is added to the inner inner core and outer outer core that make up the detector, the detector configuration becomes simple, compact and low cost, and the multi-rotation absolute angle has high resolution. There is an effect that it is possible to provide a compound type detector which can detect and is reliable. As an embodiment of the present invention, the case of the light reflection type sensor and the magnetic type sensor has been described, but a sensor such as a light transmission type, an electromagnetic type or an electrostatic type which can obtain an analog signal of one cycle per rotation is attached. Needless to say, the same function can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a composite detector of the present invention.

FIG. 2 is a diagram for explaining output signals of the composite detector of the present invention.

FIG. 3 is a diagram showing the configuration of another composite detector.

FIG. 4 is a diagram showing a configuration of a conventional brushless resolver.

FIG. 5 is a diagram for explaining an output signal of a conventional brushless resolver.

[Explanation of symbols]

1 shaft 11 bracket 2 Brushless resolver 22 Follow shaft 3 inner core 31 Inner coil 4 Outer core 41 outer coil 5 rotor 51 rotor coil 6 stator 61 Stator coil 7,71 I / O lead 8 frames 9, 91 Control circuit 10A, 10B Reflective sensor 101 reflector 11A, 11B Magnetic sensor 111 ferrite magnet

Claims (3)

[Claims] 1. A brushless multi-pole resolver for supplying electric power to a rotor in a non-contact manner with a rotary transformer, comprising: a disc fixed to an end face of an inner core of the rotary transformer; and 90 degrees in a rotating direction of the rotor. And two sensors that are provided separately from each other and are fixed to the outer core portion of the rotary transformer so as to face the disk, and that function as the surface to be detected by the disk. , One of the two sensors produces a sine wave of one cycle per revolution, while the other sensor produces a cosine wave of one cycle per revolution,
A composite type detector characterized in that, in addition to the function of the brushless type multi-pole resolver, the multi-angle absolute angle detection and the rotation direction detection are performed. 2. The surface of the disk is formed with a reflecting portion that reflects light and a non-reflecting portion that does not reflect light, and the shape of the non-reflecting portion is annular and its center is the rotor. The two sensors are eccentric from the center, and each of the two sensors includes a light emitting unit that emits light to apply light to the surface of the disc, and a light receiving unit that receives the light reflected by the surface of the disc. The hybrid detector according to claim 1, wherein the detector is a hybrid detector. 3. The disk is a magnet magnetized in the radial direction so that the inner and outer poles are different poles, and the boundary between the inner and outer magnetic poles forms a circle whose center is the center of the rotor. 2. The combined detector according to claim 1, wherein the two sensors are magnetic sensors and are eccentric to each other.