JP5847470B2 - Pointer device - Google Patents

Description

  The present invention relates to a pointer device, and in particular, a stepping motor including a plurality of excitation coils and a magnet rotor that rotates following a change in the excitation state of the plurality of excitation coils, and interlocks with the rotation of the magnet rotor. And a rotation control means for controlling the rotation of the magnet rotor by controlling the drive voltage supplied to the exciting coil.

  Conventionally, as the above-described pointer device, for example, one that is mounted on a vehicle and indicates a vehicle speed or the like is known (Patent Documents 1 to 3). The pointer device includes a stepping motor, a pointer that rotates in conjunction with the rotation of the stepping motor, a microcomputer as a rotation control unit that controls the rotation of the stepping motor, and the like. As shown in FIG. 7, the stepping motor 3 described above has two A-phase and B-phase excitation coils 31a and 31b, a stator 32 that supports these A-phase and B-phase excitation coils 31a and 31b, and NS poles alternately. Are provided with a magnet rotor 33 that is magnetized by three poles each and rotates following the change in the excitation state of the A-phase and B-phase excitation coils 31a and 31b, and a gear 34a that transmits the rotation of the magnet rotor 33 to the pointer. .

  Next, the operation of the pointer device described above will be described with reference to FIG. When the ignition switch is turned on and wakes up (Y in step S10), the microcomputer that controls the operation of the entire pointer device described above is in a state in which the drive voltage supply to the A-phase and B-phase excitation coils 31a and 31b is cut off. A drive voltage having a predetermined phase and a predetermined duty is supplied to the A-phase and B-phase exciting coils 31a and 31b to stop the rotation of the magnet rotor 33 (step S11).

  In step S11, as indicated by a black circle in FIG. 12, for example, a driving voltage having a phase of π / 4 and a duty of 70% is output. That is, in response to the ignition switch being turned on, the A-phase and B-phase exciting coils 31a and 31b are suddenly supplied with a large drive voltage with a duty of 70% from the non-excited state as shown in FIG. Thereafter, the microcomputer performs an initialization operation for forcibly rotating the pointer in the reverse direction toward the measured value 0 (step S12), and then performs a normal operation for driving the pointer to indicate the measured value of the sensor (step S12). S13).

  When the A-phase and B-phase exciting coils 31a and 31b are not energized, as shown in FIG. 7 (B) or (C), the position can be balanced from time to time due to the relationship between the iron (stator 32) and the magnet rotor 33. Stop at. In this state, when the magnet rotor 33 is stopped by applying a drive voltage to the A-phase and B-phase exciting coils 31a and 31b, the A-phase and B-phase exciting coils 31a and 31b are generated as shown in FIG. In some cases, the magnet rotor 33 is rotated to a position corresponding to the magnetic field to be generated.

  At this time, as described above, when a large driving voltage of 70% duty is applied to the A-phase and B-phase exciting coils 31a and 31b from the non-excited state (0 point in FIG. 12), The magnet rotor 33 vibrates in the vicinity of the position shown in FIG. 7A, and unnecessary movement (rotation) occurs in the magnet rotor 33. As a result, as shown in FIG. 13, the pointer 2 moves momentarily, and there is a problem that it looks bad. Further, since a large driving voltage with a duty of 70% is applied to the A-phase and B-phase exciting coils 31a and 31b suddenly from the non-excitation, the magnet rotor 33 moves greatly, and the reverse rotation angle in the initialization operation Becomes larger. In addition, there is a problem that it is necessary to perform an initialization operation after the vibration of the magnet rotor 33 is stopped, and it takes time to complete the initialization operation.

  Returning to the operation, after that, when the ignition switch is turned off and the sleep condition is satisfied (Y in step S14), the microcomputer performs the initialization operation again (step S15), and then the A-phase and B-phase excitation coils. A drive voltage having a predetermined phase (π / 4) and a predetermined duty (70%) is supplied to 31a and 31b to stop the rotation of the magnet rotor 33 (step S16). Next, the microcomputer cuts off the supply of the drive voltage to the A-phase and B-phase exciting coils 31a and 31b (step S17) and returns to step S1. That is, the A-phase and B-phase exciting coils 31a and 31b are de-energized from a state where a large driving voltage with a duty of 70% is supplied as shown in FIG.

  When the magnet rotor 33 is stopped by applying a drive voltage to the A-phase and B-phase excitation coils 31a and 31b, the magnet rotor 33 is configured to have the A-phase and B-phase excitation coils 31a and 31b as shown in FIG. When the drive voltage supply to the A-phase and B-phase exciting coils 31a and 31b is cut off, the relationship between the iron (stator 32) and the magnet rotor 33 is stopped at a position corresponding to the magnetic field generated in the stator (including the stator 32). Therefore, as shown in FIGS. 7B and 7C, it may rotate to a position where it can be balanced from time to time.

  At this time, as described above, when a large drive voltage with a duty of 70% is applied to the A-phase and B-phase excitation coils 31a and 31b (black circle in FIG. 12), suddenly no excitation (point 0 in FIG. 12) The magnet rotor 33 vibrates in the vicinity of the position shown in FIGS. 7B and 7C, and unnecessary movement (rotation) occurs in the magnet rotor 33. For this reason, similarly, as shown in FIG. 13, the pointer vibrates momentarily and there is a problem that it looks bad. In addition, since the A-phase and B-phase exciting coils 31a and 31b are suddenly de-energized from a state in which a large driving voltage with a duty of 70% is applied, the magnet rotor 33 moves greatly, and the measured value is slightly smaller than zero. There was also a risk of instructing the disengaged state.

JP 2004-347456 A Japanese Patent No. 3828792 JP 2007-232436 A

  Accordingly, the present invention provides a pointer device that can reduce unnecessary rotation of the magnet rotor and the behavior of the pointer when the excitation coil is switched from the non-excitation state to the excitation state, or when switching from the excitation state to the non-excitation state. Is an issue.

  The invention according to claim 1 for solving the above-described problem is a stepping motor comprising a plurality of exciting coils and a magnet rotor that rotates following changes in the excitation state of the plurality of exciting coils, and the magnet rotor. In the pointer device comprising: a pointer that moves in conjunction with the rotation of the motor; and a rotation control unit that controls a rotation of the magnet rotor by controlling a drive voltage supplied to the excitation coil, the rotation control unit includes: When switching from a non-excitation state in which the supply of drive voltage to the excitation coil is stopped to a state in which a drive voltage of a predetermined phase and a predetermined voltage is supplied to the excitation coil to stop the magnet rotor, the drive of the predetermined phase is performed. The pointer device is characterized in that the voltage value is gradually increased from 0 to obtain the predetermined voltage.

According to a second aspect of the present invention, there is provided a stepping motor composed of a plurality of exciting coils and a magnet rotor that rotates following the change in the excitation state of the plurality of exciting coils, and moves in conjunction with the rotation of the magnet rotor. In a pointer device comprising a pointer and a rotation control means for controlling the rotation of the magnet rotor by controlling a drive voltage supplied to the excitation coil, the rotation control means has a predetermined phase and a predetermined phase on the excitation coil. When switching from the state in which the drive voltage of the voltage is supplied to stop the magnet rotor to the non-excitation state in which the supply of the drive voltage to the excitation coil is stopped, the voltage value of the drive voltage in the predetermined phase is gradually reduced to zero. The pointer device is characterized in that the supply of the driving voltage is stopped by reducing the size.

  As described above, according to the first aspect of the present invention, the rotation control means supplies the drive voltage of the predetermined phase and the predetermined voltage to the excitation coil from the non-excitation state in which the supply of the drive voltage to the excitation coil is stopped. When switching to the state where the magnet rotor is stopped, the voltage value of the drive voltage of the predetermined phase is gradually increased from 0 to become the predetermined voltage, so unnecessary rotation of the magnet rotor when switching from the non-excitation state to the excitation state And the behavior of the pointer can be reduced. Thereby, the start time of the initialization operation performed thereafter is also shortened, and the reverse return angle can be reduced.

  According to the second aspect of the present invention, the rotation control means is the non-excitation in which the supply of the drive voltage to the excitation coil is stopped from the state where the magnet rotor is stopped by supplying the excitation coil with the predetermined phase and the predetermined voltage to the excitation coil. When switching to the state, the drive voltage supply is stopped by gradually decreasing the voltage value of the drive voltage of the predetermined phase, so unnecessary rotation of the magnet rotor and the behavior of the pointer when switching from the excited state to the non-excited state Can be reduced.

It is a block diagram which shows one Embodiment of the pointer apparatus of this invention. FIG. 2 is a partially exploded perspective view of the pointer device shown in FIG. 1. It is a figure which shows the exciting coil, magnet roller, etc. which comprise the stepping motor shown in FIG. It is a flowchart which shows the process sequence of the microcomputer which comprises the pointer apparatus shown in FIG. It is a time chart of the drive voltage supplied to ON / OFF of a power supply, ON / OFF of an ignition switch, and the A phase and B phase excitation coil which comprise the pointer apparatus shown in FIG. It is a figure which shows the relationship between the drive voltage and phase which are supplied to the A phase exciting coil and B phase exciting coil which comprise the pointer apparatus shown in FIG. It is explanatory drawing for demonstrating the behavior of the magnet rotor which comprises the pointer apparatus shown in FIG. It is a graph which shows the rotation angle of the magnet rotor which comprises the pointer apparatus shown in FIG. 1, and the rotation angle of the magnet rotor which comprises the conventional pointer apparatus. It is a time chart of the drive voltage in other embodiments. It is a flowchart for demonstrating operation | movement of the microcomputer which manages control of the conventional pointer apparatus. It is a time chart of on-off of a power supply, on-off of an ignition switch, and the drive voltage supplied to the A-phase and B-phase exciting coil which comprises the conventional pointer apparatus. It is a figure which shows the relationship between the drive voltage supplied to the A-phase and B-phase exciting coil which comprises the conventional pointer apparatus, and a phase. It is explanatory drawing for demonstrating the behavior of the pointer of the conventional pointer apparatus.

  The pointer device of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing an embodiment of the pointer device of the present invention. 2 is a partially exploded perspective view of the pointer device shown in FIG. FIG. 3 is a diagram showing an excitation coil, a magnet roller, and the like that constitute the stepping motor shown in FIG.

  As shown in FIG. 1, the pointer device 1 includes a plurality of pointers 2 (see FIG. 2), a plurality of stepping motors 3 that respectively drive the pointers 2, and rotation control means that controls the rotation of the stepping motors 3. Microcomputer (hereinafter referred to as microcomputer 4) and EEPROM 5 which is a non-volatile memory for storing various data.

  As shown in FIG. 2, the pointer 2 is provided on a dial plate provided with a scale indicating a measurement value of a sensor such as a speed sensor. As shown in FIG. 3, each of the stepping motors 3 includes an A-phase and B-phase excitation coils 31a and 31b, a stator 32 that supports these A-phase and B-phase excitation coils 31a and 31b, and these A-phase and B-phases. Magnet rotor 33 that rotates following the change in the excitation state of excitation coils 31a and 31b, gears 34a to 34c that transmit the driving force of magnet rotor 33 to pointer 2 (see FIG. 2 for gears 34b and 34c), and these A case (see FIG. 2).

  As shown in FIG. 3, the A-phase and B-phase excitation coils 31a and 31b are attached to the stator 32 so that the axial directions intersect at 90 degrees. The stator 32 includes a yoke 32a surrounding the A-phase and B-phase exciting coils 31a and 31b and a magnet rotor 33 described later, and a coil bobbin projecting inward from the yoke 32a and wound with the A-phase and B-phase exciting coils 31a and 31b. And a supporting pole 32b.

  The magnet rotor 33 is provided in a disk shape, and N poles and S poles are alternately magnetized by three poles along the outer periphery thereof. The gear 34 a is fixed to the rotating shaft of the magnet rotor 33. As shown in FIG. 2, the gear 34 b is fixed to the rotating shaft of the pointer 2. As shown in FIG. 2, the gear 34 c is provided so as to mesh with both the gear 34 a fixed to the magnet rotor 33 and the gear 34 b fixed to the pointer 2. Thereby, when the magnet rotor 33 rotates, the pointer 2 also rotates via the gears 34a to 34c.

  Further, as shown in FIG. 2, the stepping motor 3 has a piece 35 that interlocks with the rotation of the magnet rotor 33 and a stopper 36 that abuts the piece 35 and mechanically stops the rotation of the stepping motor 3. doing. The piece 35 protrudes from a disk portion 37 fixed to the gear 34b described above. The stopper 36 protrudes from the case. The pointer 2 is driven into the rotating shaft of the stepping motor 3 so that the pointer 2 indicates the measured value 0 on the scale provided on the dial when the piece 35 and the stopper 36 are in contact with each other.

  As shown in FIG. 1, the microcomputer 4 operates by receiving power from the power supply IC 6. The power supply IC 6 generates a supply voltage for the microcomputer 4 from the in-vehicle battery B. Further, an ignition switch IG is connected to the microcomputer 4 via an interface (hereinafter referred to as I / F) 7. The microcomputer 4 functions as a drive circuit 41 and outputs a drive voltage to the A-phase excitation coil 31a and the B-phase excitation coil 31b of the stepping motor 3. In the present embodiment, the microcomputer 4 functions as the drive circuit 41, but the drive circuit 41 may be provided separately from the microcomputer 4.

  Next, the operation of the pointer device 1 configured as described above will be described with reference to FIG. FIG. 4 is a flowchart showing a processing procedure of the microcomputer 4 constituting the pointer device 1 shown in FIG.

  When the ignition switch IG is turned on and the microcomputer 4 described above shifts from the sleep mode to the normal mode and wakes up (Y in step S1), the microcomputer 4 has a predetermined phase with respect to the A-phase and B-phase excitation coils 31a and 31b. While supplying the drive voltage, the duty of the drive voltage is gradually increased from 0 as shown by the portion surrounded by the dotted line in FIG. 5 (step S2). In the present embodiment, a driving voltage having a phase of π / 4 is output as shown in FIG. That is, the negative side of the A-phase and B-phase excitation coils 31a and 31b is connected to the ground, and drive voltages of the same magnitude (that is, the same duty) are supplied to the positive sides of the A-phase and B-phase excitation coils 31a and 31b. ing. The microcomputer 4 increases the duty of the drive voltage until a predetermined duty (for example, 70%) is reached.

  When the duty of the drive voltage reaches a predetermined duty (Y in step S3), the microcomputer 4 performs an initialization operation for forcibly rotating the pointer 2 backward toward the measured value 0 (step S4). When the rotation of the stepping motor 3 is controlled so as to reversely rotate the pointer 2, the piece 35 and the stopper 36 come into contact with each other when the pointer 2 reaches the measured value 0, and the pointer 2 is forcibly stopped at the 0 position. Thereafter, the microcomputer 4 performs a normal operation in which the pointer 2 is driven so as to indicate the measured value of the sensor (step S5).

  Thereafter, when the ignition switch IG is turned off and the sleep condition is satisfied (Y in step S6), the initialization operation is performed again (step S7), and then a predetermined phase (with respect to the A phase and B phase exciting coils 31a and 31b ( π / 4), a drive voltage with a predetermined duty (70%) is supplied to stop the rotation of the stepping motor 3, and the duty of this drive voltage is gradually increased as shown in the portion surrounded by the one-dot chain line in FIG. (Step S8). The microcomputer 4 reduces the duty of the drive voltage until it reaches 0%.

  When the duty of the drive voltage reaches 0% (Y in step S9), the microcomputer 4 returns to step S1 again, assuming that the A-phase exciting coil 31a and the B-phase exciting coil 31b are controlled to be non-excited.

  Details of the above-described operation will be described with reference to FIGS. When waked up, the microcomputer 4 has a duty of 70% from the 0 point in FIG. 6 where both the A-phase and B-phase excitation coils 31a and 31b are not excited to the + side of the A-phase and B-phase excitation coils 31a and 31b. The duty of the drive voltage is gradually increased along the line connecting the zero point and the black circle so as to go to the black circle in FIG. 6 where the drive voltage is applied. After that, by outputting a drive voltage along the circle shown in FIG. 6, the magnet rotor 33 is rotated forward and backward to perform initialization operation and normal operation.

  When the A-phase and B-phase exciting coils 31a and 31b are not energized, as shown in FIG. 7 (B) or (C), the position can be balanced from time to time due to the relationship between the iron (stator 32) and the magnet rotor 33. However, when the magnet rotor 33 is stopped by outputting a driving voltage of phase π / 4 to the A-phase and B-phase exciting coils 31a and 31b, as shown in FIG. The magnet rotor 33 may rotate to a position corresponding to the magnetic field generated in the excitation coils 31a and 31b.

  At this time, since a large driving voltage with a duty of 70% is suddenly applied from the non-excitation to the A-phase and B-phase exciting coils 31a and 31b, as shown by the dotted line in FIG. The magnet rotor 33 vibrates near the position shown in A), and unnecessary movement (rotation) occurs in the magnet rotor 33. On the other hand, in the present embodiment, from the non-excitation state in which the supply of the drive voltage to the A-phase and B-phase excitation coils 31a and 31b is stopped, the phase π / 4 and the duty are applied to the A-phase and B-phase excitation coils 31a and 31b. When the driving voltage of 70% (= predetermined voltage) is supplied to switch to the state in which the magnet rotor 33 is stopped, the duty of the driving voltage of phase π / 4 is gradually increased to 70%, so that FIG. 7A, the vibration of the magnet rotor 33 is reduced in the vicinity of the position shown in FIG. 7A, and unnecessary rotation of the magnet rotor 33 and the behavior of the pointer 2 are reduced when switching from the non-excitation state to the excitation state. it can. Thereby, the start time of the initialization operation performed thereafter is also shortened, and the reverse return angle can be reduced.

  Thereafter, when the sleep condition is satisfied, the microcomputer 4 starts the A-phase and B-phase excitation coil 31a from the black circle in FIG. 6 in which a driving voltage with a duty of 70% is applied to the + side of the A-phase and B-phase excitation coils 31a and 31b. , 31b, the duty of the drive voltage is gradually decreased along the line connecting the black circle and the zero point so as to go to the zero point in FIG.

  When the magnet rotor 33 is stopped by applying a driving voltage of phase π / 4 to the A-phase and B-phase exciting coils 31a and 31b, the magnet rotor 33 has the A-phase and B-phase as shown in FIG. Although it stops at a position corresponding to the magnetic field generated in the excitation coils 31a and 31b (including the stator 32), if the supply of drive voltage to the A-phase and B-phase excitation coils 31a and 31b is cut off, iron (stator 32) and magnet Because of the relationship with the rotor 33, as shown in FIG. 7B or FIG. 7C, it may rotate to a position where it can be balanced from time to time.

  At this time, conventionally, since the A-phase and B-phase excitation coils 31a and 31b are suddenly de-energized from the state where the driving voltage of 70% is applied, as shown by the dotted line in FIG. ) Or the position shown in (C), the magnet rotor 33 vibrates, and unnecessary movement (rotation) occurs in the magnet rotor 33. On the other hand, in the present embodiment, the A-phase and B-phase excitation is performed from the state in which the magnet rotor 33 is stopped by supplying the driving voltage of phase π / 4 and duty 70% to the A-phase and B-phase excitation coils 31a and 31b. When switching to the non-excitation state in which the supply of the drive voltage to the coils 31a and 31b is stopped, the drive voltage supply is stopped by gradually decreasing the duty of the drive voltage of a predetermined phase, as shown by the solid line in FIG. The vibration of the magnet rotor 33 near the position shown in FIG. 7B or FIG. 7C is reduced, and unnecessary rotation of the magnet rotor 33 and the behavior of the pointer 2 when switching from the excited state to the non-excited state. Can be reduced.

  In the above-described embodiment, the voltage value of the drive voltage is changed by causing the microcomputer to function as a drive circuit and changing the duty of the drive voltage. However, the present invention is not limited to this. A drive circuit different from the microcomputer may be provided to increase or decrease the voltage value itself of the drive voltage.

  In the above-described embodiment, the duty is uniformly increased or decreased during the period from when the driving voltage reaches 0 to 70% or during the period from 70% to 0. However, the present invention is not limited to this. It is not limited. For example, as shown in FIG. 9A, the period in which the duty of the drive voltage starts to increase and the period immediately before reaching the duty of 70% as a result of the increase are gradually increased from the period in between. May be. Further, as shown in FIG. 9B, the period in which the duty of the driving voltage starts to decrease and the period immediately before reaching 0 as a result of the decrease may be reduced more gradually than the period in between. Good.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 Pointer device 2 Pointer 3 Stepping motor 4 Microcomputer (rotation control means)
31a A phase excitation coil (excitation coil)
31b B phase excitation coil (excitation coil)
33 Magnet rotor

Claims (2)

A stepping motor composed of a plurality of excitation coils and a magnet rotor that rotates following changes in the excitation state of the plurality of excitation coils, a pointer that moves in conjunction with the rotation of the magnet rotor, and a supply to the excitation coil In a pointer device provided with a rotation control means for controlling the rotation of the magnet rotor by controlling the drive voltage to be
When the rotation control unit switches from a non-excitation state in which the supply of drive voltage to the excitation coil is stopped to a state in which the magnet rotor is stopped by supplying a drive voltage having a predetermined phase and voltage to the excitation coil. The pointer device characterized by gradually increasing the voltage value of the driving voltage of the predetermined phase from 0 to the predetermined voltage. A stepping motor composed of a plurality of excitation coils and a magnet rotor that rotates following changes in the excitation state of the plurality of excitation coils, a pointer that moves in conjunction with the rotation of the magnet rotor, and a supply to the excitation coil In a pointer device provided with a rotation control means for controlling the rotation of the magnet rotor by controlling the drive voltage to be
When the rotation control unit switches from a state in which a drive voltage of a predetermined phase and a predetermined voltage is supplied to the excitation coil to stop the magnet rotor to a non-excitation state in which the supply of the drive voltage to the excitation coil is stopped. The pointer device characterized in that the voltage value of the drive voltage of the predetermined phase is gradually reduced to 0 to stop the supply of the drive voltage.

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