JPH11183113A - Angle detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the output of analog signals in a simple structure by relatively rotating a magnetic field detecting means and a magnetic field generating means about the center part of a magnetic path forming part, rotating one direction of a magnetic field from the magnetic field generating means, and changing the impedance of each coil installed to each shaft of the magnetic path forming part. SOLUTION: When an external magnetic field is exerted on a magnetic path forming part, the X-component Hx of the external magnetic field and a magnetic filed Hd by an exciting voltage is opposite in direction is an X-axis coil X2, the intensity of a magnetic filed at this part is lowered, the impedance of the coil becomes great, and the exciting voltage of the end of a resistor R6 becomes great. The X-component Hx and the magnetic field Hd are the same in direction in a coil X1, the intensity of its magnetic field is increased, its impedance becomes small, and the exciting voltage of the end of a resistor R7 becomes small. In other words, an X-axis output Vx is outputted according to the X-axis component Hx of the external magnetic filed. An output proportional to the intensity of the Y-axis component Hy of the external magnetic filed is obtained on a Y-axis in a similar way. Therefore, a magnetic filed detecting sensor 10 obtains output is signals by the external magnetic field from the rotator of a rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle detecting device suitably used in machine tools, industrial equipment, general office automation equipment and the like, and more particularly, to an analog signal for detecting an absolute angle when a shaft or the like rotates. The present invention relates to an output angle detection device.

[0002]

2. Description of the Related Art Conventionally, machine tools, industrial equipment, general O
In order to detect the rotation angle of a rotating unit such as a shaft in an A-apparatus or the like, various angle detection devices are used. Among these sensors, an angle detection device that outputs a signal in accordance with a change in the rotation angle of the rotating unit, and that performs an absolute angle detection, includes an absolute rotary encoder that outputs a digital signal and a precision rotation encoder that outputs an analog signal. Potentiometer, synchro, resolver and the like can be mentioned.

Here, the absolute rotary encoder has a disk-shaped rotary slit having a complicatedly coded slit on the rotary shaft side, and a fixed slit mounted on the stator (stator) side. There is widely known an optical structure in which a plurality of light receiving elements are turned on / off by transmitting and blocking light emitted from a light emitting element emitted through a rotary slit through a rotating slit.

An absolute rotary encoder that outputs a digital signal always supplies an incremental encoder with a backup power supply such as a battery and holds the count value as an absolute value, or generates an absolute rotary signal from two different wavelengths of an incremental scale. Based on the phase difference, the absolute value of a set section is calculated (Japanese Patent Publication No. Sho 5
No. 0-23618, "Measuring device") is known.

Furthermore, the absolute rotary encoder directly records absolute value information on a scale,
For reading the information, a binary code such as binary gray is recorded as a pattern on a scale, and the binary code is detected by detecting the pattern to read the binary code. A magnetic code which records a cyclic code such as a code on a scale as a pattern, detects the pattern, reads the cyclic code, and converts it into absolute value information of a position (Japanese Patent Laid-Open No. 57-175211, A device for detecting the angle of a rotating body ") is known.

On the other hand, a precision rotary potentiometer is a device for directly or indirectly transmitting a mechanical displacement to a drive shaft, and detecting an electrical displacement corresponding to the displacement by a partial pressure method by a rotation operation of the drive shaft. Among them, those having particularly high resolution and high precision performance are defined. The principle of operation of this precision rotary potentiometer is that the slider attached to the drive shaft slides on the resistance element, and the voltage on the resistance element corresponding to the mechanical angle is output from the slider mechanism. Things.

The synchro is similar in appearance and structure to a three-phase winding synchronous generator, and includes a comb-shaped core, a three-phase winding part and a sliding contact part. And Further, the resolver has a structure similar to a synchro, and the winding part is not a three-phase winding but a quadrature (two-phase) winding.

[0008]

By the way, the angle detecting devices such as the precision rotary potentiometer, the synchro, and the resolver for outputting the analog signal have conventionally had the following problems. For example, the precision rotary potentiometer has a structure in which the slider moves by contacting the resistive element as described above, so that both parts are inevitably worn, the element and performance are degraded, the basic product life, etc. There was a problem that the existence of the inevitable. Further, the structure of the synchro and the resolver is considerably complicated as compared with the above-described absolute rotary encoder, and since the structure has a sliding contact portion as described above, similarly, the performance is deteriorated and the basic There is a problem that the existence of a typical product life is inevitable. Note that there is a variable reluctance (VR) type resolver without a sliding contact portion, but the structure of the comb-shaped core and the winding portion is also the same in this type, and the above-described absolute rotary encoder is used. The structure was complicated as compared with.

As described above, among angle detection devices that perform absolute angle detection, those that output an analog signal are conventionally known.
There were structural problems such as a complicated structure and a short life. On the other hand, from the principle and structure of the above-described absolute rotary encoder that outputs a digital signal, it has been difficult to simply configure a magnetic angle detection device that outputs an analog signal.

The present invention has been proposed in view of such circumstances, and has as its object to provide a magnetic angle detecting device that outputs an analog signal with a simple structure.

[0011]

In order to solve the above-mentioned problems, an angle detecting device according to the present invention is made of a material having high magnetic permeability, and has a plurality of shafts extending radially on the same plane from a central portion. A magnetic path forming unit, a magnetic field detecting unit having a coil attached to each axis of the magnetic path forming unit, and a magnetic field detecting unit disposed close to each axis of the magnetic field detecting unit at equal intervals, Magnetic field generating means for generating a magnetic field in one direction parallel to the plane on which the magnetic field is formed, and the magnetic field detecting means and the magnetic field generating means are supported so as to rotate relative to the center of the magnetic path forming portion as the center of rotation. .

In the angle detecting device, the magnetic field detecting means and the magnetic field generating means rotate relative to each other about the center of the magnetic path forming part, so that the magnetic field in one direction from the magnetic field generating means rotates, The impedance of each coil attached to each axis of the forming section changes.

[0013]

Embodiments of the present invention will be described in detail with reference to the drawings. The directions such as up, down, left, right, and XY used in the following description are based on the drawings.

FIG. 1 is a plan view showing an example of the structure of a magnetic path forming portion which is a component of the magnetic field detection sensor 10 described later. The magnetic path forming portion 1 has a substantially cross-shaped planar shape, and four bars 1a, 1b, 1c, and 1d have a central portion 1
e and extend radially on the same plane.

The central portion 1e has a disk shape.
A hole 1f is formed at the center. In addition, each bar 1
a to 1d are bars 1a and 1b, as shown in FIG.
And the bar 1c and the bar 1d are respectively linear,
The bars 1a to 1d are connected to each other by a central portion 1e so as to form an angle of 90 degrees with each other. Hereinafter, for convenience of explanation, the bars 1a and 1b are collectively called a bar 1X, and the bars 1c and 1d are collectively called a bar 1Y.

The magnetic path forming section 1 has a cross-shaped open magnetic path composed of bars 1X and 1Y which are two axes orthogonal to each other. The dimensions of the magnetic path forming part 1 are the bars 1X,
The distance from the end of 1Y to the boundary between the bars 1X, 1Y and the center 1e is 7 mm, respectively, and the radius of the circle of the center 1e is 1.
5 mm (there is a bar 1X, 1Y
7 mm), the width of each of the bars 1X and 1Y is 0.6 mm,
The diameter of the hole 1f is 0.8 mm, and the thickness of each of the bars 1X and 1Y and the center 1e is 0.05 mm.
(Note that the dimensions are merely examples, and are not intended to limit the invention. The same applies to each of the following parts.) As the material of the magnetic path forming part 1, permalloy is used. In processing the magnetic path forming portion 1, a plate made of permalloy is formed into the above-described shape and dimensions by etching. The mechanical strength may be reinforced by bringing a nonmagnetic material having substantially the same shape into close contact with the magnetic path forming portion 1.

The material of the magnetic path forming portion 1 may be any material as long as it is a high permeability magnetic material. In addition to permalloy, amorphous metal and the like are preferable materials for the magnetic path forming portion 1. As the amorphous metal, those having a FeCoSiB composition are generally used in many cases.

As shown in FIG. 2, the magnetic field detecting sensor 10 has a bobbin 2 with respect to each bar 1a to 1d of the magnetic path forming section 1.
And a coil body 3 including a coil. Here, when the coil body 3 is attached, the bobbin 2 (2a, 2b, 2
The coils X1, X2, Y1, and Y2 are wound around c, 2d) with the same number of turns. At this time, the coils X1 to Y2
Coils X1 to Y
Increase the number of turns of 2. In this embodiment, by setting the number of turns to 1200 turns at this time, the inductance can be obtained relatively easily and a large value of about 10 mH, leading to a high impedance, and low power consumption of the entire apparatus. Made possible.

The number of turns may be less than 1200 turns unless it is necessary to reduce the power consumption. As a result of conducting an experiment in which the number of windings was reduced, it was confirmed that even when the number of turns was reduced to about 50 turns, the function was sufficient.

The magnetic field detection sensor 10 in which the coil body 3 is mounted on each bar of the magnetic path forming section 1 is further mounted on the substrate 4 as shown in FIG. This substrate 4
It is formed in a substantially circular planar shape by an insulating material, and a planar annular rising wall portion 5 is formed at the center of one main surface 4A. A hole 11 having substantially the same diameter as the hole 1f of the magnetic path forming portion 1 is formed at the center of the main surface 4A of the substrate 4 surrounded by the rising wall 5. The rising wall 5 has cutouts 6, 7, 8, and 9 having substantially the same width as the width of each bar of the magnetic path forming section 1. Of these, the notch 6 and the notch 8 face each other around the hole 11, and the notch 7 and the notch 9 also
They are facing each other around 1.

The substrate 4 having such a configuration is attached so that the ends of the bars in the magnetic path forming portion 1 of the magnetic field detection sensor 10 are fitted into the cutout portions 6, 7, 8, and 9, respectively. . At this time, as shown in FIG. 3, the hole portion 1f of the magnetic path forming portion 1 is positioned so that the hole 11 of the substrate 4 and the plane position coincide with each other. Then, in this state, the hole 1
The magnetic field detection sensor 10 is fixed to the board 4 by fitting a fixed guide pin (not shown) into the hole f and the hole 11. The fixed guide pin is provided in the magnetic path forming portion 1.
It also has a function as an index indicating the center of.

Further, on the main surface 4A of the substrate 4 surrounded by the rising wall 5, each coil X
Eight metal pin members 12 to which the conductors from 1 to Y2 are connected by soldering are attached. Each pin member 12
Penetrates to the other main surface 4B of the substrate 4. On the other main surface 4B of the substrate 4, a chip component (not shown) such as an IC constituting an exciting means 42, a smoothing circuit 43 and the like, which will be described later, is attached.
Is a cable 1 to be described later through terminals of the chip component.
3 will be connected.

On the other hand, a plurality of mounting holes 14, 14 are formed in both main surfaces of the substrate 4 outside the rising wall portion 5. Here, the number of the mounting holes 14 is two in the drawing, but the number of the mounting holes 14 may be three or more.

For convenience of explanation, the substrate 4 on which the above-described magnetic field detection sensor 10, fixed guide pins, pin members 12, chip components, cables 13 and the like are mounted is referred to as a detection sensor unit 20.

FIG. 4 is a sectional view of a main part of the angle detecting device 30 of the present invention. In the angle detecting device 30, a stator 22 is mounted inside a substantially cup-shaped housing 21, and a rotor 23, supports 26, 26, and a space 23 formed in the space formed by the housing 21 and the stator 22. The detected sensor unit 20 is provided.

The rotor 23 includes a disk-shaped rotor 24 and a shaft 25 integrally attached to the center of the main surface of the rotor 24. The shaft 25 is formed at the center of the stator 22. The ball bearings 28, 28 and the spacer 29
It is rotatably mounted via. More specifically, the shaft portion 25 has a ball bearing 28, 28
It is almost the same as the inside diameter of Further, the shaft portion 25
On the side attached to the rotor 24, an abutment portion 25a having a diameter larger than the inner diameter of the ball bearing 28 is formed. Then, the rotor 23 is
Is abutted against the ball bearing 28 so as to be rotatably attached to the rotor attachment opening 27 of the stator 22.

Here, the structure of the rotor 23 will be described with reference to FIG. The rotor 23 has its rotor 24
Is formed into a disk shape by a plastic magnet. The rotor 24 is magnetized in one direction in the plane of the disk-shaped surface as shown by the arrow in FIG. The rotor 24 having such a configuration has a function as a means for generating an external magnetic field with respect to the magnetic field detection sensor 10 described above.

The rotor 24 has a small-diameter guide hole 3 at a rotation center point in the plane of the board facing the magnetic field detection sensor 10.
1 is engraved. The guide hole 31 is used for positioning the detection sensor unit 20 when the detection sensor unit 20 is attached to the stator 22.

The detection sensor unit 20, as shown in FIG.
By being attached to the stator 22 in which the rotor 23 is incorporated via the supporting columns 26, 26 formed integrally with the stator 22, it serves as means for detecting a magnetic field from the rotor 24 of the rotor 23. More specifically, the detection sensor unit 20 is configured such that the rising wall 5 of the substrate 4 faces the direction facing the rotor 23, and the screws 32 are attached to the mounting holes 1.
It is fixed to the stator 22 by screwing into the screw holes (not shown) of the columns 26, 26 via the holes 4, 14.

At this time, as shown in FIGS. 6A and 6B, the hole 1 of the magnetic path forming section 1 in the detection sensor section 20 is formed.
Positioning is performed so that the center of f and the guide hole 31 of the rotor 24 are coaxial. Specifically, the center of the above-mentioned fixed guide pin fitted into the hole 1f of the magnetic path forming portion 1 and the hole 11 of the substrate 4 is positioned so that the guide hole 31 of the rotor 24 is coaxial. Fine-tune the alignment. At this time, as shown in FIGS. 6A and 6B, the plane formed by the board of the rotor 24 and the plane formed by the magnetic path forming unit 1 are substantially parallel with a predetermined interval. Make fine adjustments so that With these fine adjustments, the angle detection device 30 can obtain an accurate output signal.

Note that, as shown in FIG.
The cable 13 is connected to the main surface 4B side of the substrate 4 at 0 as described above. This cable 13 is
The housing 21 is drawn out of the housing 21 via a packing member 34 attached to the hole 33.

Here, referring to FIG.
The principle of detecting a magnetic field at 0 will be described. As described above, since the rotor 24 of the rotor 23 uses the plastic magnet magnetized in one direction in the plane of the board, the magnetic field generated by the plastic magnet to the outside (hereinafter, referred to as an external magnetic field). A substantially uniform magnetic field in one direction is applied to the magnetic field detection sensor 10 in the detection sensor unit 20. The magnetic field applied to the magnetic field detection sensor 10 rotates with the rotation of the rotor 23. Therefore, the output signal from each axis of the magnetic field detection sensor 10 is an output corresponding to the strength of the axial component of the external magnetic field. Specifically, as described later, the output signal is output from the rotor 24.
As a result, the magnetic field changes in a sinusoidal manner by rotation.

Next, referring to FIG.
The method by which the magnetic field detection sensor 10 detects the rotation angle of the rotor 23 will be described. FIG. 8 shows the detection sensor unit 20.
FIG. 3 is a diagram showing an example of the circuit configuration of FIG. In this figure,
Regarding the magnetic field detection sensor 10, the magnetic path forming part 1 contributing to the operation function and the coil X1 located on each axis (each bar) thereof
Only Y2 is extracted and shown.

In this circuit shown in FIG.
1, and R2, R3, transistors TR1 and TR2, a capacitor C1, and a high-frequency oscillator 41 composed of IC1 and an excitation means 42 composed of a transformer T are used to excite. The high-frequency oscillator 41 uses a multivibrator circuit.

The output side of this circuit includes a resistor R8,
R9, R10, R11, capacitors C2, C3, C4
A smoothing circuit 43 including C5 and capacitors C6 and C7 is connected to the magnetic field detection sensor 10 via diodes D2 to D5.

Here, the output of the high-frequency oscillator 41 is set so that the period at which the detection sensitivity of the exciting means 42 becomes the best is about 40 μS and the pulse width is about 2 μS. The IC1 of the high-frequency oscillator 41 uses a Schmitt inverter having hysteresis to prevent chattering.
Since this output has a large inductance of the coil, the transformer T boosts the output three times so that the magnetic field of the magnetic path forming unit 1 becomes Hd, and excites the magnetic path forming unit 1 as described later.

When the excitation voltage is applied, the direction of the magnetic field of each of the coils wound around the magnetic path forming unit 1 becomes outward in the X-axis coils X1 and X2, and the Y-axis coils Y1 and Y2
Are wound inward, and one of the coils is connected to one side of the transformer T and the other is connected to the other side of the transformer T via resistors R4 to R7. The strength of the magnetic field when the excitation voltage is applied is determined by the magnetic field Hd at which the impedance of each coil wound around the magnetic path forming unit 1 changes sharply.
Excited until.

Here, assuming that no external magnetic field is applied, the shape of the magnetic path forming portion 1, the number of turns of each coil, and the magnetic field Hd due to the excitation voltage are also equal. Therefore, since the impedance of the coils of each axis in the magnetic path forming unit 1 becomes equal, the magnitudes of the excitation voltages generated at both ends of the resistors R4 to R7 are all equal, and the resistors R8 to R11 are connected via the diodes D2 to D5.
The outputs of the capacitors C2, C3, C4, C5 and the capacitors C6, C7 that have passed through the smoothing circuit 43 are also equal, so that the outputs of the X-axis output Vx and the Y-axis output Vy become zero. The smoothing circuit 43 has a time constant sufficiently larger than the period of the excitation voltage.

Next, considering a case where an external magnetic field is applied to the magnetic path forming unit 1, in the X-axis coil X2, the direction of the X component Hx of the external magnetic field and the direction of the magnetic field Hd due to the excitation voltage are mutually different. Because it is the opposite, the magnetic field strength in this part decreases,
As is well known, the impedance of the coil increases, and the excitation voltage at the end of the resistor R6 also increases. Conversely, X-axis coil X
In 1, the direction of the X component Hx of the external magnetic field is the same as the direction of the magnetic field Hd due to the excitation voltage, and the magnetic field strength increases, so that the impedance decreases and the excitation voltage at the end of the resistor R7 decreases.

As a result, the voltage on the X-axis coil X2 through the smoothing circuit 43 increases, and the voltage on the X-axis coil X1 decreases, so that the X-axis output Vx appears in the direction indicated by the arrow in the figure. If the direction of the X component Hx of the external magnetic field is reversed, X
It is not necessary to explain that the shaft output Vx is also in the opposite direction. As described above, an output corresponding to the intensity of the X-axis component Hx of the external magnetic field is obtained as the X-axis output Vx.

Hereinafter, the magnetic path forming unit 1
Are the same except that the direction of the magnetic field Hd due to the excitation voltage is opposite to that of the X-axis coil and the spatial arrangement is different by 90 °, so that the Y-axis component Hy of the external magnetic field is similarly strong. Thus, an output proportional to the output will be obtained.

Therefore, as described above, the rotor 23
A substantially uniform magnetic field in one direction is applied to the magnetic field detection sensor 10 by an external magnetic field from the rotor 24 of FIG. Then, the output signal from the X-axis of the magnetic field detection sensor 10 changes sinusoidally due to the rotation of the magnetic field accompanying the rotation of the rotor 23. On the other hand, the output signal from the Y-axis of the magnetic field detection sensor 10 is a signal shifted by 90 degrees in phase from the output signal from the X-axis.

FIG. 9 shows the result of measuring the relationship between the rotation angle of the rotor 23 and the output voltage in the angle detection device 30. As is clear from this characteristic diagram, analog outputs of sine and cosine waves whose phases are shifted from each other by 90 degrees are obtained with high accuracy with small errors as the output signals Vx and Vy. Further, it can be seen that the cycle of each of the output signals Vx and Vy becomes one cycle when the rotor 23 makes one rotation.

As described above, according to the angle detecting device 30,
A magnetic field detection sensor 10 in which a pair of coils are provided on bars 1X and 1Y, which are two axes orthogonal to each other in the cross-shaped magnetic path forming unit 1, and circuits such as an exciting unit 42 and a smoothing circuit 43;
While having a simple configuration of a rotor 23 having a plastic magnet rotor 24 that applies a substantially uniform magnetic field in one direction to the magnetic field detection sensor 10, the rotor 23 has a simple structure.
Can output signals of analog sine and cosine waves having a period proportional to the rotation of.

According to the angle detecting device 30, since the magnetic path forming portion 1 is processed by using the etching method as described above, the dimensions and the shape of the magnetic path forming portion 1 are accurately obtained. As a result, accurate output can be obtained for each of the output signals Vx and Vy without adjusting the phase difference.

Further, according to the angle detecting device 30, since there is no sliding portion between the rotor 23 and the detecting sensor section 20, it is not necessary to consider the life due to abrasion of the sliding parts.

Further, according to the angle detecting device 30,
The coil body 3 in which the coil is wound around the bobbin 2 is connected to the magnetic path forming unit 1.
, The coil can be easily wound, multiple windings can be easily performed, and the winding operation can be performed in a separate step, so that the assembling efficiency is greatly improved.

Further, according to the angle detecting device 30, since the hole 1f, the hole 11, and the guide hole 31 are provided at the center positions of the magnetic path forming portion 1, the substrate 4, and the rotor 24, respectively. It is possible to perform accurate positioning on the basis of the above, thereby providing a low-cost and high-performance product.

FIGS. 10 and 11 show a modified example of the rotor 23. FIG. Note that the same parts as those in the above-described embodiment are denoted by the same reference numerals. FIG. 10 shows a case where the rotor has a rectangular plate shape with respect to the rotor. In this rotor 23A shown in FIG.
Is a bar-shaped magnet magnetized in the longitudinal direction.

The rotor 23B shown in FIG. 11 is obtained by attaching two magnets 44 and 45 to a rotor 24B having a substantially disk shape. Specifically, the rotor 23B is
A pair of cutouts 46, 46 are formed at symmetrical positions around the guide hole 31 outside the main surface of the rotor 24B, and the magnets 44, 45 are fitted into the cutouts 46, 46. As a result, it has a substantially circular shape in a plane.
In this rotor 23B, two magnets 4
For 4,45, the magnetization directions are the same as each other,
The magnet is magnetized so that the outside of the magnet 44 has an N pole and the inside of the magnet 45 has an N pole. In addition, rotor 2
Needless to say, the number of magnets attached to 3B is not limited to this example.

The rotor 24A of the rotor 23A
As for the materials of the magnets 44 and 45 of the rotor 23B, in addition to the above-mentioned plastic magnets, sintered magnets such as ferrite magnets, CuNiFe, FeCrC
An alloy magnet such as o may be used. In addition, the shape of the rotor is not limited to the above-described example, but may be any as long as it applies a substantially uniform external magnetic field to the magnetic field detection sensor 10 of the detection sensor unit 20. .

Next, another example of the configuration of the angle detecting device will be described with reference to FIGS. The same parts as those in the above-described embodiment are denoted by the same reference numerals,
The description is omitted as appropriate. In the angle detecting device 50 shown in FIG. 12, a housing 52 in which the rotor 24 made of the above-described plastic magnet is incorporated is attached to a main surface 51A on the distal end side of the rotating shaft 51.

As the rotating shaft 51, for example, a rotating shaft of a predetermined machine tool (not shown) for measuring a rotation angle can be used.

As shown in FIG. 13, the housing 52 has a substantially ring-shaped outer shape, and is formed at the center thereof with the same diameter as the diameter of the rotor 24 in order to mount the rotor 24 thereon. It has a circular mounting portion 53 with four holes 54 formed in its main surface. In the angle detecting device 50, the rotor 24 is fitted into the mounting portion 53 of the housing 52, and in this state, the housing 52 contacts the main surface 51A of the rotating shaft 51. The housing 52 and the rotor 24 are attached to the main surface 51 </ b> A of the rotating shaft 51 by screwing the housing 52 with the screw 55. In this attachment, positioning is performed so that the rotation center of the rotation shaft 51 and the guide hole 31 of the rotor 24 are coaxial.

In the angle detecting device 50, the rising wall 5 of the substrate 56 in which the magnetic field detecting sensor 10 shown in FIG. The substrate 56 has the same structure as that of the substrate 4 except that the outer shape is substantially square in a plane.
The upright wall portion 5 is formed at the center of one main surface 56A, and the other main surface 56B
The I, which constitutes the exciting means 42, the smoothing circuit 43, etc.
A chip component such as C and a cable 13 are attached.

The substrate 56 is attached to, for example, a predetermined fixing device or the like (not shown). On the other hand, the rotating shaft 51 on which the housing 52 and the rotor 24 are disposed is rotated in a direction indicated by an arrow AB by a bearing (not shown). Supported as possible. Here, the rotor 24 and the rising wall 5 of the substrate 56 are connected to the hole 1 of the magnetic path forming unit 1 in the same manner as in the above-described embodiment.
f and the center of the fixed guide pin fitted into the hole (not shown) of the substrate 56 and the guide hole 31 of the rotor 24 are coaxial, as shown in FIGS. 6 (a) and 6 (b). Then, the positioning is performed so that the plane formed by the board surface of the rotor 24 and the plane formed by the magnetic path forming portion 1 incorporated in the rising wall portion 5 are substantially parallel with a predetermined interval.
By performing the positioning in this manner, the angle detection device 50 can obtain an accurate output signal.

In this embodiment, the rotor 24 made of a plastic magnet is attached to the main surface 51A on the distal end side of the rotary shaft 51 via the housing 52. However, this rotor 24 is attached to the main surface 51A of the rotary shaft 51. Needless to say, it may be configured to be directly attached to the camera.

According to the angle detecting device 50, the rotor 24 is attached to the main surface 51A on the tip end side of the rotating shaft 51 of the machine tool or the like whose rotational angle is to be measured. Mechanical parts such as the stator 22 can be omitted, and a further simple configuration can be achieved.

According to the angle detecting device 50, the detection sensitivity of the magnetic field detection sensor to the magnetic field is very high. Therefore, even when the rotor 24 is a plastic magnet using ferrite magnetic powder, the rotor It has been confirmed that it is possible to arrange each of them with a sufficient distance from the detection sensor. Further, it was confirmed that this interval can be changed by selecting the magnetic material, size, and shape of the rotor 24.

In the angle detecting device 50, for example, when the range of the rotation angle of the rotating shaft 51 is narrow, the substrate 56 is fixed to the main surface 51A of the rotating shaft 51 and the rotor 24 is fixed. Needless to say, such a configuration may be adopted.

Next, a modification of the magnetic path forming section 1 will be described with reference to FIG.
4 and FIG. The magnetic path forming part 1A shown in FIG. 14 has six bars 1a, 1b, 1c, 1d, 1
g and 1h extend radially from the center 1e on the same plane. Here, similarly to the magnetic path forming portion 1 shown in FIG. 1, the central portion 1e has a disk shape, and a hole 1f is formed in the center thereof. Also, each bar 1a, 1b,
1c, 1d, 1g, and 1h are as shown in FIG.
Bar 1a and bar 1b, bar 1c and bar 1d, and bar 1
g and the bar 1h are respectively linear, and each bar 1a, 1b, 1c, 1d, 1g, and 1h is 60
They are connected by a central portion 1e so as to form an angle of degrees.

The angle detector 30 or the angle detector 5
In the case of using the magnetic path forming part 1A to form the magnetic field detection sensor 0, six coil bodies 3 are attached to each bar in order to form a magnetic field detection sensor. Since the configuration is the same as that of the embodiment, the description is omitted. According to the magnetic field detection sensor using the magnetic path forming portion 1A, three phases (U, V, W phases) which are shifted from each other by 120 degrees.
Can be output.

The angle between the bars of the magnetic path forming portions 1 and 1A may not be set to be equal to each other as in the above-described embodiment, or may be changed to a predetermined angle as necessary. .

The magnetic path forming part 1B shown in FIG. 15 has a structure in which every other bar 1a, 1h, 1d is omitted from the above magnetic path forming part 1A, that is, three bars 1b, 1c, 1g are arranged at the center. 1e, extending radially on the same plane,
Each of the bars extends from the central point at an angle of 120 degrees on the same plane by the same length.

In this case, the three coil bodies 3 are arranged on each axis to constitute a magnetic field detection sensor, but the operation thereof is different from that of the previous embodiments, and Since only one coil corresponds, it does not operate differentially, and outputs a signal only in one direction in one direction. The other points are the same as those of the above-described embodiments, and the description thereof is omitted. According to the magnetic field detection sensor using the magnetic path forming unit 1B, similarly to the magnetic field detection sensor using the magnetic path forming unit 1A, the three phases (U,
(V, W phase) analog signals can be output.

In the magnetic field detection sensor using the magnetic path forming section 1B, the number of signals can be increased by further increasing the number of bars of the magnetic path forming section 1B. Also, the angle between the bars of the magnetic path forming portion 1B may not be set to be equal to each other, and may be changed to a predetermined angle as needed.

Next, another embodiment of the angle detecting device will be described with reference to FIGS. FIG.
FIG. 10 is a cross-sectional view of a main part of an angle detection device 60 according to another embodiment. In this angle detecting device 60, a housing 61 and a stator 62 are combined and coupled at each end, and a shaft mounting shaft 64 is provided in a space formed by the housing 61 and the stator 62. A rotor 63 composed of a rotor 65 and a detection sensor unit 80 composed of a magnetic field detection sensor 70, a sensor mounting member 72, a circuit board 73 and the like are provided.

The housing 61 has a substantially cup-shaped outer shape, and has a circular hole 61a formed in the center thereof.

The stator 62 has a substantially donut shape on a plane, and has a cylindrical rising wall portion 62a formed at the center thereof, and the inner peripheral surface of the rising wall portion 62a has a rotor mounting opening 66 for mounting the rotor 63. Has become.

The rotor 63 comprises a shaft mounting shaft 64 and a disk-shaped rotor 65, as shown in FIG. The shaft mounting shaft 64 has a substantially ring-shaped locking portion 64 for locking the rotor 65 on the upper portion of the substantially pipe-shaped main body 64a.
b are provided, and both are integrally formed. Here, the diameter of the main body 64a is slightly smaller than the diameter of the hole 61a of the housing 61 described above. As shown in FIG. 16, the main body 64 a is located below the locking portion 64 b in the drawing.
Abutment portion 64c slightly larger than the diameter of the contact portion 64c is formed.

The shaft mounting shaft 64 has a shaft insertion portion 64d formed so as to penetrate in the longitudinal direction of the main body portion 64a, so that a rotating shaft of a machine tool or the like (not shown) can be inserted into the shaft insertion portion 64d. It has become. Further, the shaft mounting shaft 64 is formed with a shaft mounting hole 64e, which is a screw hole for fixing the rotating shaft, at an upper portion of the main body 64a. This allows
The shaft mounting shaft 64 does not require coupling with a rotating shaft of a machine tool or the like.

The rotor 65 is formed into a disk shape by a plastic magnet magnetized in one direction, as shown by an arrow in FIG. 17, and has a circular hole 65 at its center.
a is provided. The diameter of the hole 65a is substantially equal to the diameter of the abutting portion 64c of the shaft mounting shaft 64. Then, by inserting the hole 65a of the rotor 65 into the main body 64a of the shaft mounting shaft 64 from the lower side in the drawing, the hole 65a fits into the abutting portion 64c, and the rotor 65 is mounted on the shaft mounting shaft. The rotor 63 is fixed to the rotor 64 and the rotor 63 is assembled.

As shown in FIG. 18, the detection sensor section 80 has a magnetic field detection sensor 70 formed by attaching the coil body 3 to each bar of the magnetic path forming section 71, and this magnetic field detection sensor 70 is a sensor mounting member. The sensor mounting member 72 is mounted on the sensor mounting member 72 from below in the drawing.

The magnetic path forming portion 71 of the magnetic field detection sensor 70
Has a substantially cross-shaped planar shape similarly to the magnetic path forming portion 1 shown in FIG. 1, and has a configuration in which four bars are radially extended on the same plane from a disk-shaped central portion 74. The central portion 74 and the hole 7 formed inside the central portion 74
5 is different from the magnetic path forming section 1 in that it has a large diameter.

The sensor mounting member 72 has a substantially cruciform planar shape similarly to the magnetic path forming portion 71, and four sensor mounting pieces are formed from the side surface of the cylindrical base portion 76 in which the mounting hole 77 is formed. 78 has a structure formed to project in four orthogonal directions. Here, the diameter of the mounting hole 77 is determined by the magnetic path forming portion 7.
It is equal to the diameter of one hole 75. Each sensor mounting piece 78 has a substantially rectangular planar shape, and
A rising protrusion 79 is formed on the base end side connected to 6, and a cutout 81 is formed in the center of the upper end of the rising protrusion 79. Further, each of the sensor mounting pieces 78 has a protruding portion 82 formed on the tip end side. This projection 8
2 is formed so as to protrude vertically from the front end side of the sensor mounting piece 78, and has a cutout 83 formed at the center of the upper end thereof, and the lower end position thereof is equal to the lower end position of the base portion 76.

The sensor mounting member 7 configured as described above
As shown in FIG. 18, the base end side of each bar of the magnetic path forming portion 71 is fitted into each notch 81 of each rising protrusion 79, and the distal end side of each bar is formed as a projection 82.
The magnetic field detection sensor 70 is attached to the sensor attachment member 72 by being fitted into the notch 83 of the sensor.

The circuit board 73 has a plate shape having a substantially donut shape in a plane, and a circular hole 84 is formed at the center thereof. In the circuit board 73, the diameter of the hole 84 is the same as that of the base 7 in the sensor mounting member 72 described above.
6 is approximately equal to the diameter. On both main surfaces of the circuit board 73, chip parts such as ICs constituting the exciting means 42, the smoothing circuit 43 and the like shown in FIG.

The circuit board 73 is formed such that the hole 84 is fitted into the base 76 of the sensor mounting member 72 from below in FIG. Are bonded to each other, and the bonding portion is bonded with, for example, an adhesive to form the sensor mounting member 72.
Attached to

The detection sensor unit 80 completed as described above
As shown in FIG. 16, the fitting of the mounting hole 77 of the base portion 76 of the sensor mounting member 72 into the rising wall portion 62a of the stator 62 allows the
Mounted on top.

On the other hand, as shown in FIG. 16, the rotor 63 has a shaft mounting shaft 64 rotatably mounted on a rotor mounting opening 66 of the stator 62 via ball bearings 67, 67 and a spacer 68. At this time, the rotor 63 is formed by the plane formed by the rotor 65 and the magnetic path forming part 71 by fixing the abutting part 64c of the shaft mounting shaft 64 at a position where it abuts on the ball bearing 67. The plane is kept parallel and at a constant distance.

Then, in this state, the end of the housing 61 is connected to the end of the stator 62 so that the hole 61 a of the housing 61 allows the main body 64 of the shaft mounting shaft 64 to be connected.
Part of a is exposed. In addition, about the cable 13,
A hole (not shown) is provided on the side surface of the housing 61, and the hole is drawn out from the hole via the packing member 34.

The angle detecting device 60 having such a configuration
According to the above, by rotating the rotor 63, the same effects as those of the above-described angle detecting device 30 can be obtained. Further, according to the angle detecting device 60, a rotating shaft of a machine tool or the like can be directly mounted on the shaft mounting shaft 64 without requiring a coupling. It becomes possible to output a corresponding analog signal.

[0083]

As described above in detail, in the angle detecting device of the present invention, the magnetic field detecting means and the magnetic field generating means rotate relative to the center of the magnetic path forming portion as the center of rotation, thereby generating the magnetic field. The unidirectional magnetic field from the means rotates,
Since the impedance of each coil attached to each axis of the magnetic path forming unit changes, by applying an excitation voltage to each coil, a multi-phase analog output signal corresponding to the change in the impedance can be obtained.

Therefore, according to the present invention, it is possible to provide a magnetic angle detection device that outputs an analog signal while having a simple structure. Further, according to the angle detecting device of the present invention, since there is no sliding portion between the magnetic field detecting means and the magnetic field generating means, there is no risk of performance degradation due to wear of the sliding parts.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating an example of a structure of a magnetic path forming portion that is a component of a magnetic field detection sensor.

FIG. 2 is a plan view illustrating a configuration of a magnetic field detection sensor.

FIG. 3 is a perspective view showing a state where a magnetic field detection sensor is attached to a substrate.

FIG. 4 is a sectional view of a main part of the angle detecting device of the present invention.

FIG. 5 is a perspective view illustrating a configuration of a rotor of the angle detection device.

6A and 6B are diagrams showing a positional relationship between the rotor and a magnetic path forming portion, wherein FIG. 6A is a perspective view and FIG. 6B is a front view.

FIG. 7 is a diagram illustrating a principle of detecting a magnetic field in the angle detection device.

FIG. 8 is a diagram illustrating an example of a circuit configuration in the angle detection device.

FIG. 9 is a characteristic diagram illustrating a relationship between a rotation angle and an output voltage in the angle detection device.

FIG. 10 is a perspective view showing another configuration example of the rotor of the angle detection device.

FIG. 11 is a perspective view showing another configuration example of the rotor of the angle detection device.

FIG. 12 is a diagram showing another configuration example of the angle detection device.

FIG. 13 is a perspective view showing a configuration of a housing and a rotor.

FIG. 14 is a plan view showing another example of the structure of the magnetic path forming unit.

FIG. 15 is a plan view showing another example of the structure of the magnetic path forming unit.

FIG. 16 is a cross-sectional view showing another embodiment of the angle detection device.

FIG. 17 is a perspective view showing a configuration of a rotor.

FIG. 18 is a perspective view illustrating a configuration of a detection sensor unit.

[Explanation of symbols]

1, 1A, 1B, 71 Magnetic path forming part, 1a, 1b, 1
c, 1d, 1g, 1h bar, 2 (2a to 2d) bobbin, 3 coil body, 4,56 substrate, 5 rising wall, 10, 70 magnetic field detection sensor, 20, 80 detection sensor unit, 30, 50, 60 Angle detecting device, 21, 61
Housing, 22, 62 stator, 23, 63 rotor, 24, 24A, 24B, 65 rotor, 25 shaft part, 31 guide hole, 41 high-frequency oscillator, 42 excitation means, 43 smoothing circuit, 64 shaft mounting axis, X
1, X2, Y1, Y2 coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichi Sato 3-9-17-1 Nishi-Gotanda, Shinagawa-ku, Tokyo In-house Sony Precision Technology Co., Ltd. (72) Inventor Yasuo Nemon 3 Nishi-Gotanda 3, Shinagawa-ku, Tokyo Sony Precision Technology Co., Ltd. In-house (72) Inventor Hideki Tsuchiya 3-9-17 Nishigotanda, Shinagawa-ku, Tokyo Sony Precision Technology Co., Ltd. In-house

Claims (1)

[Claims] 1. A magnetic path forming portion made of a high magnetic permeability material and having a plurality of shafts radially extending from a center portion on the same plane, and a coil attached to each axis of the magnetic path forming portion. A magnetic field detecting means having: a magnetic field generating means arranged in close proximity to each axis of the magnetic field detecting means at equal intervals and generating a magnetic field in one direction parallel to a plane on which each axis of the magnetic field detecting means is located; Wherein the magnetic field detecting means and the magnetic field generating means are supported so as to rotate relative to each other about the center of the magnetic path forming portion.