JP5315535B2 - Rotation angle detector - Google Patents

Description

  The present invention relates to a rotation angle detection device.

  As such a rotation angle detection device, a rotary encoder or a resolver is used. The rotary encoder optically or magnetically detects a periodic structure formed on the rotor. On the other hand, the resolver is provided with a coil in the stator and detects the rotation angle by detecting the phase of the alternating current that appears according to the relative angle between the stator and the rotor when alternating current is passed through the stator. is there.

  In general, a rotary encoder can detect an angular position with high accuracy, and an absolute rotary encoder can also detect an absolute angular position, but the problem is that the apparatus is expensive and lacks durability. is there. On the other hand, the resolver is widely used for detecting the rotation angle because the device is inexpensive and has excellent durability (see Patent Document 1).

JP 2009-8536 A

  As such a resolver, an axial double angle type is generally used. Such a double angle resolver repeatedly outputs the same angle data a plurality of times during one rotation of the rotor. For example, in the case of a resolver having a shaft angle multiplier of n, the same angle data is repeatedly output n times while the rotor rotates once. That is, when the rotor rotates 1 / n, the signal phase changes 360 degrees. Therefore, an absolute position cannot be obtained during one rotation of the rotor.

  For this reason, if the initial position at which the rotor starts rotating is always the same, it is not impossible to recognize the absolute position by integrating the number of signals from the initial position. Absent.

  The present invention has been made to solve the above problems, and provides a rotation angle detection device capable of recognizing an absolute rotation angle position while using an inexpensive and durable resolver. Objective.

  The invention according to claim 1 is a shaft multiplication angle provided with a rotor that rotates about an axis, an excitation coil disposed on an outer periphery of the rotor, and a detection coil disposed on the outer periphery of the rotor. The resolver, a plurality of magnetic sensors arranged at predetermined angles on the outer periphery of the rotor in the resolver, and the rotor in the resolver attached to the rotor and rotating in synchronization with the rotor, corresponding to the rotational angular position One magnetic sensor of the plurality of magnetic sensors or two adjacent magnetic sensors are provided with a magnet configured to detect magnetism.

According to a second aspect of the present invention, in the first aspect of the present invention, the magnetic sensor is composed of a Hall IC that is an IC element using a Hall element.

  According to a third aspect of the present invention, in the invention of the second aspect, the resolver has an axial multiplication angle of n when n is an integer of 3 or more, and the Hall IC is an outer peripheral portion of the rotor. N are arranged.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the motor for moving the valve between the open position and the closed position, and the operation of the motor is moved by the valve. A rotation angle of the motor is detected with respect to an electric valve actuator provided with a motion conversion mechanism for converting motion.

  According to the first aspect of the present invention, the absolute rotation angle can be obtained while using an inexpensive and durable resolver by the action of a plurality of magnetic sensors arranged at predetermined angles on the outer periphery of the rotor. It becomes possible to recognize the position.

  According to the second aspect of the present invention, it is possible to digitally recognize the change in magnetic force accompanying the rotation of the rotor using the Hall IC. For this reason, it becomes possible to recognize an absolute rotation angle position more reliably.

  According to the third aspect of the present invention, the absolute angular position can be surely recognized at all the angular positions.

  According to the fourth aspect of the present invention, the opening degree information in the electric valve actuator can be recognized using an inexpensive device, and the durability can be improved.

It is a schematic diagram of an electric valve actuator to which a rotation angle detection device according to the present invention is applied. It is a front view of the operation part 18 of an electric valve actuator. 2 is a schematic diagram showing a basic configuration of a resolver 14. FIG. 4 is a graph showing output signals of a pair of detection coils 33 and 35 in the resolver 14. 2 is a schematic diagram showing the resolver 14 together with a converter 36. FIG. It is a schematic diagram which shows the basic composition of a rotation angle detection apparatus. It is explanatory drawing which shows the relationship between the digital signal S output from the resolver 14 via the converter 36, and the magnetic detection signal of the magnet 37 by each Hall IC41,42,43,44.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the configuration of an electric valve actuator to which the present invention is applied will be described. FIG. 1 is a schematic view of an electric valve actuator to which a rotation angle detection device according to the present invention is applied.

  This electric valve actuator is for moving the valve 11 between the fully open position and the closed position, and controls the motor 12, the operation unit 18 for inputting the operation of the motor 12, and the motor 12. A driver 24 and a control unit 25 including a computer that transmits a control signal to the driver 24 based on an operation signal from the operation unit 18 are provided. The control unit 25 is connected to an operation panel 26 for executing a remote operation via the terminal block 19. The driver 24 is connected to the power source 27 via the terminal block 19.

  One end of a rotary shaft 13 that is rotationally driven by the motor 12 is connected to a drive sleeve 15 that is a motion conversion mechanism using a screw, via a resolver 14 that constitutes a rotation angle detection device according to the present invention. For this reason, the rotational driving force of the rotating shaft 13 is converted into a driving force for reciprocating the valve 11 between the fully open position and the closed position. Further, the rotation angle position of the rotation shaft 13 at that time is detected by a rotation angle detection device including the resolver 14. Further, the other end of the rotating shaft 13 is connected to the handle wheel 16 via a springless clutch 17. This handle wheel 16 is used when the valve 11 is manually opened and closed.

  FIG. 2 is a front view of the operation unit 18 described above.

  The operation unit 18 includes a first operation changeover switch 21, a second operation changeover switch 22, and a display unit 23. The first operation changeover switch 21 can execute a mode selection operation between a direct operation mode in which the valve is directly operated using the operation unit 18 and a remote operation mode in which the valve is remotely operated using the operation panel 26. Is. The second operation changeover switch 22 can execute a mode selection operation of an opening operation mode for opening the valve 11, a closing mode for closing the valve 11, and a stop mode for stopping the opening / closing operation of the valve 11. And the display part 23 is for displaying the opening degree of the valve 11, the mode selection state by the 1st operation changeover switch 21 or the 2nd operation changeover switch 22, an operation state, a setting value, etc.

  In this electric valve actuator, when the valve is operated remotely, the first operation changeover switch 21 is rotated and switched to the “REMOTE” side. Thereby, the valve is opened and closed by operating the operation panel 26 shown in FIG. 1 through the electric valve actuator.

  On the other hand, in this electric valve actuator, when the valve is directly operated using the operation unit 18, the first operation changeover switch 21 is rotated and switched to the "LOCAL" side. When the second operation changeover switch 22 is rotated and switched to the “open” side, the valve 11 in the valve moves toward the open position, and when switched to the “closed” side, the valve 11 in the valve moves toward the closed position. Moving. If the second operation changeover switch 22 is rotated and switched to the “stop” side, the valve 11 in the valve stops at that position.

  Next, the structure of the resolver 14 used for this invention is demonstrated. FIG. 3 is a schematic diagram showing the basic configuration of the resolver 14.

  The resolver 14 is disposed at a position different from the rotor 32 rotating around the shaft 31, the excitation coil 34 disposed on the outer periphery of the rotor 32, and the excitation coil 34 on the outer periphery of the rotor 32. A pair of detection coils 33 and 35 are provided. The excitation coil 34 and the pair of detection coils 33 and 35 are wound around a stator (not shown).

  The gap between the rotor 32 and the stator around which the excitation coil 34 and the pair of detection coils 33, 35 are wound changes according to the angular position of the rotor 32, and the pair of detection coils 33, 35 is the rotor 32. And a two-phase output signal having a sin curve and a cos curve based on the change in the gap between the stator and the stator.

The resolver 14 is of a type with a shaft angle multiplier of 4, and the rotor 32 has a substantially cross shape. In the resolver 14, the same output signal is repeatedly output four times during one rotation of the rotor 32. That is, in the resolver 14, the rotor 32 is 1/4.
When rotated, the phase of the output signal changes 360 degrees. In the case of a type with a shaft angle multiplier of 3, the rotor has a substantially triangular shape, and the same output signal is repeatedly output three times during one rotation of the rotor.

  FIG. 4 is a graph showing output signals of the pair of detection coils 33 and 35 in the resolver 14. FIG. 5 is a schematic diagram showing the resolver 14 together with a converter 36 that converts the output signals of the detection coils 33 and 35 into digital signals.

  Between the terminals S1 and S3 of the detection coil 33, an output signal is generated in which the change in voltage indicated by the symbol A in FIG. On the other hand, between the terminals S2 and S4 of the detection coil 35, an output signal is generated in which the change in voltage indicated by B in FIG. These output signals are converted into a digital signal S described later in the converter 36.

  Next, the configuration of the rotation angle detection device according to the present invention will be described. FIG. 5 is a schematic diagram showing the resolver 14 together with the converter 36. FIG. 6 is a schematic diagram showing a basic configuration of the rotation angle detection device. Note that numerals 0, 90, 180, and 270 in FIG.

  This rotation angle detection device includes four Hall ICs 41, 42, 43, 44 disposed on the outer periphery of the rotor 32 in the resolver 14 at 90 degree angles, and a magnet 37 attached to the rotor 32. Is provided. The magnet 37 has an N pole on the outer side of the rotor 32 and an S pole on the inner side, and is disposed in a region reaching an angular range of about 100 degrees on the outer peripheral portion of the rotor 32. The magnet 37 rotates in synchronization with the rotor 32, and one of the four Hall ICs 41, 42, 43, and 44, or two adjacent ones of the Hall ICs 41, 42, 43, and 44 correspond to the rotation angle position. The Hall IC is configured to detect magnetism.

  FIG. 7 is an explanatory diagram showing the relationship between the digital signal S output from the resolver 14 via the converter 36 and the magnetic detection signals of the magnets 37 by the Hall ICs 41, 42, 43, 44. Note that the numbers 0, 90, 180, 270, and 360 in FIG.

  As described above, the resolver 14 repeatedly outputs the same output signal four times during one rotation of the rotor 32, and the output signal is converted into the digital signal S by the converter 36. The digital signal S is a linear signal output every 90 degrees with respect to one rotation of the rotor 32. On the other hand, the magnetism detection signal of the magnet 37 by the four Hall ICs 41, 42, 43, 44 is a signal shown in a rectangular shape below in FIG. In this figure, each of the magnetic detection signals of the magnet 37 by the four Hall ICs 41, 42, 43, 44 is given the same reference numeral in parentheses.

  As described above, the magnet 37 is disposed in a region reaching the angle range of about 100 degrees on the outer peripheral portion of the rotor 32, and corresponds to the rotational angle position of the rotor 32, and the four Hall ICs 41, 42, One Hall IC 43 or 44 or two adjacent Hall ICs are configured to detect magnetism. For this reason, the magnetism detection signals of the magnets 37 by the four Hall ICs 41, 42, 43, 44 partially overlap each other.

  According to the magnetic detection signal of the magnet 37 by the four Hall ICs 41, 42, 43, 44, the origin of the rotor 32 is any of the four quadrants formed by the four Hall ICs 41, 42, 43, 44. Whether it is in an angular position can be recognized. That is, the digital signal S output four times during one rotation of the rotor 32 can be distinguished. The absolute angular position of the rotor 32 can be recognized based on the digital signal S. For this reason, according to this rotation angle detection device, it is possible to recognize the absolute rotation angle position while using the resolver 14.

  As described above, the magnetism detection signals of the magnets 37 by the four Hall ICs 41, 42, 43, 44 partially overlap each other, and the four Hall ICs 41, 42, 43, 44 are among the four Hall ICs 41, 42, 43, 44. One Hall IC or two adjacent Hall ICs are always configured to detect magnetism. For this reason, it is possible to always recognize the rotational angle position of the rotor 32 by recognizing which of the four Hall ICs 41, 42, 43, 44 detects magnetism. In the state where the two Hall ICs detect magnetism, the position may be recognized by referring to the digital signal S at that time.

  In the above-described embodiment, the resolver 14 is of the type whose axial double angle is 4, but the type of n when n is an integer of 3 or more, such as the type of 3 or the type of 5, Can be used. Note that when using a type with a shaft angle multiplier of 2, it is difficult to recognize the position in a state where the two Hall ICs detect magnetism. It becomes difficult to appropriately determine the absolute angular position.

  In the embodiment described above, since a Hall IC that is an IC element using a Hall element is used as the magnetic sensor, a change in magnetic force accompanying the rotation of the rotor 32 can be digitally recognized. However, the present invention is not limited to this, and other magnetic sensors can be used.

14 Resolver 31 Axis 32 Rotor 33 Detection Coil 34 Excitation Coil 35 Detection Coil 36 Converter 37 Magnet 41 Hall IC
42 Hall IC
43 Hall IC
44 Hall IC
S Digital signal

Claims (4)

A rotor that rotates about an axis, an excitation coil disposed on an outer periphery of the rotor, and a resolver having a shaft angle multiplier provided on a detection coil disposed on the outer periphery of the rotor;
A plurality of magnetic sensors arranged at predetermined angles on the outer periphery of the rotor in the resolver;
One of the plurality of magnetic sensors or two adjacent magnetic sensors is attached to a rotor in the resolver and rotates in synchronization with the rotor, and corresponding to the rotational angle position. A magnet configured to detect magnetism;
A rotation angle detection device comprising: The rotation angle detection device according to claim 1,
The said magnetic sensor is a rotation angle detection apparatus comprised from Hall IC which is an IC element using a Hall element. In the rotation angle detection device according to claim 2,
The resolver has an axial multiplication angle of n, where n is an integer of 3 or more,
The number of the Hall ICs is a rotation angle detection device arranged n on the outer periphery of the rotor. In the rotation angle detection device according to any one of claims 1 to 3,
The rotation angle of the motor with respect to an electric valve actuator comprising a motor for moving the valve between an open position and a closed position and an operation conversion mechanism for converting the operation of the motor into a movement operation of the valve Rotation angle detection device for detecting

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