KR100274359B1 - Indicator and its operation method - Google Patents

Abstract

The indicator 50, which is a measuring device, is a synthesized coil magnetic field driven by a step motor and supplied with a sine wave drive current and a cosine wave drive current by a rotor magnetic field formed by a field coil in the step motor 4. The indicator is returned from the stopper located in the zero position of the meter by the rotor field. Place the indicator on the stopper to prevent the rotor part from disconnecting the indicator from the stopper, then from the sine and cosine wave in the phase angle range between -340 ° and-(180 ° -Δa °) in the zero return process. The magnetic field portion to be formed is blocked.

Description

Indicator and its operation method

1 is a block diagram illustrating an indicator in accordance with the present invention.

2 is a perspective view illustrating the step motor and indicator portion shown in FIG.

3 is a partial cross-sectional view illustrating a stator and a magnet rotor of the step motor shown in FIG.

4 is a schematic diagram of the stator and magnet rotor of the step motor shown in FIG.

5 is a flowchart showing processing of the microcomputer of the indicator according to the first embodiment.

6 is a flowchart of a zero return routine according to the first embodiment.

7 is a flowchart of a zero return routine according to the first embodiment.

8 is a graph showing the relationship between the zero return current supplied to each of the windings of the stepper motor and the phase angle of the zero displacement current of the indicator at the end of each setting cycle according to the first embodiment.

9 is a flowchart of a zero position return routine according to the second embodiment.

10 is a flowchart of a zero position return routine according to the second embodiment.

FIG. 11 is a graph showing the relationship between the waveform of the zero return current supplied to each winding and the phase angle of the zero return current of the stepper motor at each end of the setting cycle, according to the second embodiment. .

12 is a graph showing the relationship between the waveform of the zero return current supplied to each winding of the step motor, the phase angle of the zero return current of the conventional step motor, and the angular displacement of the indicator.

* Explanation of symbols for main parts of the drawings

4 step motor 10 cylinder case

12: rod type stopper 40: permanent magnet rotor

70: drive circuit

The present invention relates to an indicator, and more particularly, to an indicator driven by a stepper motor and a method of operating the same.

Indicators driven by two-phase box-type step motors have been used for the garage. The stepper motor of the indicator has a pair of annular stators, each of which has a ring-shaped winding and a plurality of magnetic poles and a permanent magnet rotor with the same number of magnets as each stator. One stator pole is placed between the remaining stator poles and one of the windings causes the current to flow through the sinusoidal current while the other passes through the current simultaneously with the cosine wave current. As the permanent magnet rotor is driven in one direction and the two currents supplied to the windings change sinusoidally so that the indicator or pointer of the indicator moves with the magnet rotor, a rotating magnetic field is generated by the stator change. The indicator is usually adjusted to stay in the zero position when manufacturing it.

However, if shock is applied to the indicator before loading, the magnet rotor may be rotated, and the indicator may also be separated from the zero position and may not be able to return to the zero position.

The indicating waste disclosed in Japanese Patent Laid-Open No. 6-38593 has a stoppertle positioned close to the zero position, and the sinusoidal current and the cosine wave current are angled to form a reverse direction rotor field so that the indicator can start to move from the zero position. Supplying a zero return current to the windings causes the magnet rotor and indicator to be in the zero position, and the indicator is on the stopper before starting operation (forward rotation).

However, if the reverse rotor field is longer than about half a cycle while the indicator and magnet rotor are spanned by the stopper, the magnetic force of the rotor field moves the opposite side of the indicator and drives the magnet rotor to separate the indicator from the stopper again. . As a result, the indicator cannot start from the zero position when it is operated in normal use (forward rotation).

For example, if a half cycle of sinusoidal wave current (180 °) is supplied to the winding when the indicator returns from the angle 30 ° position to the zero position (angle 0 ° position), the indicator is zero as shown in FIG. It fluctuates between positions repeatedly and repeatedly, and cannot stay in zero position as long as a sinusoidal wave current is supplied to the winding.

US Patent No. 5,287,050 proposes zero return control of an indicator to block zero return current when an abutment of the indicator with stop is detected from a voltage induced across both terminals of the step motor. .

However, the switching operation of the drive circuit and the voltage detection circuit has a complicated structure.

In view of the above-described state, the main object of the present invention is to provide a method for reliably operating the indicator and the zero return of the indicator having an improved indicator and a simple structure.

Another object of the invention is a means for controlling the drive circuit to form a magnetic field for supplying a zero return current to the field excitation coil of the stepper motor and to rotate the indicator towards the stopper located in the zero position, and the indicator as a stopper. It is to provide an indicator having a means for preventing a zero return current portion by forming a magnetic field separated from.

The preventing means may be means for blocking a zero return current portion forming a magnetic field to separate the indicator from the stopper. The zero return current portion is generally located in the phase angle range between -340 ° and-(180 ° -Δa °).

The means for controlling means means for supplying a zero return current to rotate the indicator at a set angle or for controlling the drive circuit to repeatedly supply a zero return current at a set period short enough for the operator to overlook the fluctuation of the indicator. Can be.

Another object of the present invention is to provide an improved method of operating the indicator, wherein the indicator feeds the cosine wave current and the sine wave current to shift the phase angle by a preset angle at the end of each set time. (field) A step for forming a full range of rotating magnetic fields in the excitation coil and rotating in the zero return direction, and the sine and cosine wave currents are zeroed so that the indicator is on the stopper without being separated from the stopper by the rotor field portion. To provide an indicator having a step of shifting the phase angles of the sine and cosine wave signals from the first angle to the second angle when moved at one angle.

It is still another object of the present invention to provide a driving circuit with a cosine wave signal and a sine wave signal for shifting the phase angle by a preset angle at the end of each set time, thereby forming a rotating magnetic field in which the rotating magnetic field rotates in the zero return direction. The present invention provides a method for operating an indicator comprising a step, a step of repeating the step by a set number of times, and a step of stopping the step of repeating when the set number of times is completed.

It is still another object of the present invention that the indicator provides a zero return current to the feed-excited coil which changes its amplitude by a preset level at the end of each set time, thereby forming a full range rotating magnetic field rotating in the zero return direction. And a step of increasing the preset level when the zero return current forms a rotor magnetic portion separating the indicator from the stopper.

Other objects, features and features of the present invention as well as the functions of the elements of the present invention will become apparent from a review of the following detailed description, the appended claims and the drawings.

Example 1

The indicator according to the first embodiment will be described with reference to FIGS. 1 to 8.

The step motor 4 has the cylinder case 10 of FIG. 2 and the rotor 40 of FIG. The cylinder case 10 accommodates a pair of upper and lower stators 20 and 30 formed in an annular shape arranged coaxially and has a rod-type stopper 12 on its upper wall 11. The upper stator 20 is composed of a pair of upper and lower yokes 21 and 22 formed in an annular shape, which is an annular phase coil (hereinafter referred to as an A phase coil) housed in the bobbin 23 as shown in FIG. Surround (). The upper yoke 21 has a flat yoke member and a plurality of (12 in this embodiment) pole teeth 21a inside the flat yoke member, and the lower yoke 22 has an L-shaped cross section. And a yoke member having the same number of pole teeth 22a on the inner side of the L-shaped yoke member between the pole teeth 21a at equal intervals (15 ° in this embodiment). The pole teeth 21a and 22a are arranged to face the rotor 40 in the air gap.

The lower stator 30 consists of a pair of upper and lower annular yokes 31, 32, which surround an annular phase coil (hereinafter referred to as B phase coil) 34 housed in the bobbin 33. The upper yoke 30 has a flat yoke member 31 and a plurality of (12 in this embodiment) pole teeth 31a inside the flat yoke member 31, and the lower yoke 31 is L. FIG. It has a yoke member 32 having a shaped cross section and a pole tooth 32a that is inside the yoke member between the pole teeth 31a at equal intervals (15 ° in this embodiment). The pole teeth 31a and 32a are arranged to face the rotor 40 in the air gap.

Each of the pole teeth 31a of the lower stator 30 is circumferentially half of the distance (7.5 ° in this embodiment) from adjacent ones of the teeth 21a of the upper stator 20 as shown in FIG. Move it. Each of the faulties 32a is equally moved from an adjacent one of the faulties 22a.

The magnet rotor 40 has an output shaft 41 and a plurality of (12 in this embodiment) N-poles and an equal number of S-pole permanent magnets, which are on the outer periphery at equal intervals (15 ° in this embodiment). Alternately placed. The output shaft 41 is supported by a bearing (not shown) fixed to the center of the upper wall of the cylinder case 10.

The indicator 50 is supported by the boss member 51 carried by the end of the output shaft 41. The shaft 41 can move the indicator 50 through the dial plate (not shown) in the upper wall of the cylinder case 10. When the indicator 50 is driven in the reverse direction by the magnet rotor 40 to return to the zero position of the dial plate, the angle δ is formed between the indicator 50 and the zero position as shown in FIG. The part 50 is eventually caught by the stopper 12.

When a positive current is supplied to the A phase coil 24, each of the pole teeth 21a indicated by A + becomes the N pole and each of the pole teeth 22a indicated by A- becomes the S pole, and the other On the other hand, when a minus current is supplied to the A phase coil 24, each of the pole teeth 21a denoted by A + becomes the S pole and each of the pole teeth 22a becomes the N pole.

When a positive current is supplied to the B phase coil 34, each of the pole teeth 31a indicated by B + becomes the N pole and each of the pole teeth 32a indicated by the B- becomes the S pole. On the other hand, when the negative current is supplied to the B phase coil 34, each of the pole teeth 31a indicated by B + becomes the S pole and each of the pole teeth 32a indicated by the B- becomes N pole. .

Therefore, when the cosine wave current and the sine wave current of the steady state angle are respectively supplied to the A phase coil 24 and the B phase coil 34 respectively, the position shown in Fig. 4 (the S pole of the magnet rotor is A + of the stator). Lastone rotor 40 at the pole) is driven in a forward direction (clockwise in FIG. 4) by 7.5 ° for every 90 ° phase angle, and on the other hand, inverse phase angle (as shown in FIG. 12). When a cosine wave current and a sine wave current of phase (starting at 0 ° toward the phase angle) are simultaneously supplied to the A phase coil 24 and the B phase coil 34, respectively, the magnet rotor 40 causes an angle of the sinusoidal wave. It is driven in the reverse direction (counterclockwise direction in FIG. 4) by 7.5 ° every 90 ° phase angle.

The indicator has a first terminal directly connected to the plus terminal of the vehicle battery 1 and a second terminal connected to the plus terminal of the same battery via the ignition switch 2.

The microcomputer 60 controls the drive circuit 70 for driving the step motor 4 through the A phase coil 24 and the B phase coil 34. The microcomputer 60 has a ROM that stores relationship data between the phase angle (per 1 °) and amplitude percentage (%) of sine and cosine wave drive currents.

The drive circuit 70 is controlled by the microcomputer 60 (control unit) to supply sinusoidal drive currents having different phases (eg 90 °) to the A phase coil 24 and the B phase coil 34. Supply.

Since the indicator as the speed meter indicates the vehicle speed in a known manner, the operation description of the preferred embodiment is mainly made for the zero return operation in the following.

The microcomputer 60 starts the zero return operation, as shown in FIG. 5, at which time the indicator is installed in the vehicle, and the microcomputer 60 is connected to the plus terminal of the battery 1.

When the microcomputer 60 operation starts, an initialization process is performed in step 100 and performed as shown in FIGS. 5 and 6 of the zero return routine from the 300 ° angular displacement of the indicator 50. . Assume that the indicator is at a 30 ° angle as shown in FIG. The horizontal axis of the graph of FIG. 8 indicates the phase angles of the cosine curve and the sinusoid in the reverse direction without the portion corresponding to the phase angle range between 180 ° and 340 °. Because the magnetic field generated in that range separates the indicator from the stopper. The phase angles designated -430 ° and -520 ° less than -360 ° indicate the phase angles of the second turn corresponding respectively to 90 ° and 180 ° of the first turn. In other words, the same or similar designations appear in the following graphs shown in FIGS. 11 and 12.

The number of zero return processing j of the indicator 50 is set to zero in step 111 shown in FIG. Then, the phase angle i is set to 0 ° and the timer of the microcomputer 60 is set to start at step 112. As a result, the amplitude values of the sine wave current and the cosine wave current corresponding to the phase angle 0 are read from the ROM, and as shown in FIG. 8, SIN (i) = SIN (0 °) COS (I) = COS ( 0 °) = 100% is applied to the drive circuit 70.

When the timer measures the set period T (e.g., 0.3 msec) that changes the phase angle by 1 ° in step 114, YES is determined to proceed to step 114a, where phase angle i = i -1 ° = -1 ° is set. The set time T is determined so that the indicator can be synchronized with the change in the rotor field generated by the phase coils 24 and 34.

Then, in step 115, the phase angle (i) is in the range between -340 ° and (180 °-Δa °) is compared. This range generally corresponds to the second half cycle of sine wave and cosine wave drive current. However, the range between -340 ° and -360 ° of the drive current constitutes a magnetic field to return the indicator to the zero position.

Since the phase angle (i) is set at −1 ° and Δa ° less than 100 ° (typically about 45 °) at this moment, NO is determined in this step and then YES is determined in step 116 so that the step ( Return to 113). The drive circuit 70 continues with the A phase coils 24 and B until the same series of steps 113, 114, 114a, 115 and 116 are repeated and step 115 determines YES as shown in FIG. The sine wave current and the cosine wave current are respectively supplied to the phase coil 34 to reduce the phase angle by 1 °, respectively.

This step removes the magnetic field that separates the rotor and indicator 50 from the stopper. As a result, as the step motor 4 rotates, the indicator 50 moves to the zero position without shaking (swinging) the stopper 12.

Then, phase angle i is updated to i = -340 ° in step 115a. Thereafter, the sinusoidal current amplitude SIN (-340 °) and the cosine wave current COS (-340 °) corresponding to the phase angle i = -340 ° are read out of the ROM to control the drive circuit 70, thereby controlling the step motor 4 ) To rotate the indicator towards the stopper 12.

Then, NO is determined at step 115 and YES is determined at step 116, and steps 113, 114, 114a, 115 and 116 are repeated until the phase angle i is equal to -360 °. .

When the phase angle (i) becomes 360 °, NO is determined in step 116, the phase angle (i) is set to 0 ° and the number of zero return processes (j) is set to j-1 in step 116a. do. If YES is determined by comparing in the next step 117 whether the number of zero return processes j is greater than -10, it means that the 30 ° return process repeats ten times, in other words, a 300 ° zero return is performed. do. Therefore, even if the indicator is moved below 300 °, the zero position can be returned without shaking the stopper during the zero return.

Thereafter, steps 113 to 117 are repeated (NO in this case 9 times) until NO is determined at step 117. When NO is determined at step 117, the timer is stopped at step 118 and the zero return process is performed. 110 ends.

The 300 ° zero return process is performed only once in the routine 130 because the indicator 50 of the instrument installed in the vehicle is not moved beyond the zero position than before the indicator 50 of the instrument is installed.

Then, each time the ignition switch 2 of the vehicle is turned on, the microcomputer 60 executes the 30 ° zero return processing routine 130 as shown in FIGS. 5 and 7.

The series of steps 131 to 135 of the zero return routine 130 shown in FIG. 7 is the same series of steps 111 to 116 of the zero return process routine 110.

When NO is determined in step 135, the phase angle i is set to 0 ° in step 136 and the sinusoidal current amplitude SIN (0 °) and the cosine wave current COS (0) corresponding to the phase angle i = 0 °. °) is read out of the ROM so that the drive circuit 70 drives the step motor 4 to have the indicator 50 at the stopper 12. The timer then stops at step 138 and the zero return routine 130 ends.

The zero return routines 110 and 130 may be applied to the indicator 50 in the zero position in order to control the indicator 50 and return from the 30 ° position. In such a case, the indicator 50 is controlled in the above manner.

After the routine 130, the process proceeds to steps 140 and 150 for speed display (forward driving), as shown in FIG. 5, where the input signal is read out and the set angular displacement θ of the indicator 50 is ₀ ) is calculated, and then the current angular displacement θa is compared with the set angular displacement θ ₀ to drive the motor 4 in the forward direction (step 151) and the reverse direction (step 152). Or proceed to step 160, where it is detected whether the ignition switch 2 is turned off. When the ignition switch 2 is turned off, YES is determined and the step motor 4 is controlled to cause the indicator 50 to be in the zero position from the current angular displacement [theta] a.

Example 2

The second embodiment will be described with reference to FIGS. 9, 10 and 11. Step 115a of the first embodiment is replaced with 115b in the third embodiment.

While the phase angle (i) varies in the range between 340 ° and-(180 ° -Δa °), the zero return operating speed of the indicator 50 is such that the fluctuation of the indicator 50 cannot be perceived by the operator. Increase at a rate of 2 times.

As the indicator moves, it can follow the increased speed of the zero return operation. As long as the indicator can follow the cycle of change of the sinusoidal current, the speed can be increased by twice the speed in the remaining range.

The invention can be applied to three phase step motors including permanent magnets and other hybrid motors. If a zero return structure is provided it can also be applied to the single phase motor of the present invention.

The sinusoidal control current supplied to the winding can be replaced by the rest of the control current, such as approximate sinusoidal current, trapezoidal current, and so on.

The stopper 12 may be disposed except for the upper wall 11 of the cylinder case 10.

The control step of the zero return operation may be placed in a hard logic element.

While the invention has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, numerous modifications will be apparent to those skilled in the art.

It will be understood that such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.

Claims (13)

A step motor 4 having a pair of field excitation coils and a permanent magnet rotor 47, an indicator 50 rotatable with the step motor, and a drive current to generate a magnetic field. A drive circuit 70 for supplying to the excitation coil, a control unit 60 for controlling the drive circuit according to a given state, a ROM, and the indicator at the zero position of the indicator when the indicator returns to the zero position. An indicator having a stopper (12) which stops the control, wherein the control unit supplies a zero return current to the feed exciting coil to form a magnetic field to control the drive circuit to rotate the indicator toward the stopper. And means for preventing the zero return current portion from forming a magnetic field separating the indicator from the stopper. 2. The indicator according to claim 1, wherein said prevention means comprises means for disconnecting said indicator from said stopper to block said zero return current portion forming a magnetic field. The indicator as claimed in claim 2, wherein the control means supplies the zero return currents to control the driving circuit by rotating the indicator by a set angle. 4. The indicator according to claim 3, wherein the control means controls the drive circuit by repeatedly supplying the zero return current within a set period. 2. The combined exciting magnetic field according to claim 1, wherein the shielded excitation coil has a pair of phase windings 24 and 34, and the control means supplies each of a pair of sinusoidal wave currents having different phase angles. And an indicator configured to control the driving circuits. 6. The indicator as set forth in claim 5, wherein said preventing means comprises means for interrupting a pair of sinusoidal current portions in which said indicator is separated from said stopper to form a magnetic field. A step motor 4 having a shielded excitation coil and a permanent magnet rotor 40, an indicator 50 rotatable with the step motor, a control current signal generator for generating a control signal, and according to the control signal A driving circuit 70 for supplying a driving current to the feed exciting coil to form a rotating magnetic field; and a stopper 12 for stopping the indicator at the zero position of the indicator when the ROM and the indicator return to the zero position. The control current signal generator, wherein the control current signal generator supplies a zero return current to the feed excitation coil to generate a signal to control the drive circuit by the indicator to rotate the stopper to form a composite magnetic field Means for blocking said signal portion forming a magnetic field to separate said indicator from said stopper. Watch group. A step motor 4 having at least two feed excitation coils 24 and 34 and a permanent magnet rotor 40, an indicator 50 rotatable with the step motor, and a control current signal for generating a control signal A generator, a driving circuit 70 for supplying a driving current to the feed excitation coil in accordance with a signal of the control current signal generator, a ROM, and the zero position of the indicator when the indicator returns to the zero position. An indicator having a stopper for stopping an indicator, the control current signal generator comprising: means for generating a pair of sinusoidal signals such that the feed-excited coil forms a synthetic magnetic field to rotate the indicator toward the stopper; And means for blocking said sinusoidal signal portion such that said permanent magnet rotor is not separated from said stopper. A step motor 4 having at least two feed excitation coils 24 and 34 and a permanent magnet rotor 40, the step motor and the rotatable indicator 50, and a control current signal for generating a control signal. A generator, a driving circuit for supplying a drive current to the feed excitation coil in accordance with a signal from the control current signal generator, and stopping the indicator at the zero position of the indicator when the ROM and the indicator return to the zero position. In a method of operating an indicator with a stopper 12, a rotating magnetic field that provides a cosine wave signal and a sine wave signal for shifting a phase angle by a preset angle when each set time is completed, and rotates in the zero return direction. And a sinusoidal and cosine wave such that the indicator is on the stopper and does not leave the stopper caused by the rotor field portion. Skipping phase signals of the sine wave and cosine wave from the first angle to the second angle when the signal is shifted to the first angle. A motor 4 having a shielded excitation coil and a permanent magnet rotor 40, an indicator 50 rotatable with the stepper motor, a drive circuit 70 for driving the motor, a ROM, and the indicator A method of operating an indicator comprising a stopper 12 for stopping the indicator at the zero position of the indicator when the signal is returned to the zero position, wherein the zero return current changes the amplitude to a preset level at the end of each set time. Providing the feed excitation coil to form a complete rotor field rotating in the zero return direction, and the current forming the rotor field portion so that the indicator is on the stopper and does not leave the dropper. And a step of exceeding the range. A step motor 4 having at least two shielded coils 24 and 34 and a permanent magnet rotor 40, an indicator 50 rotatable with the step motor, and a control current signal generator for generating a control signal; And a driving circuit 70 for supplying a driving current to the feed excitation coil according to the signal of the control current signal generator, a ROM, and the indicator zero when the indicator is returned to the zero position. A method of operating an indicator with a stopper 12 for stopping at a position, the driving circuit comprising a cosine wave signal and a sine wave signal for shifting a phase angle by a preset angle at the end of each set time of less than 10 milliseconds. A step of forming a rotating magnetic field rotating in the zero return direction, a step of repeating the step by a set number of times, and a step of stopping the repetition when the set number of times ends. Indicator operating method characterized in that the comparison. A step motor 4 having a feed excitation coil 24 and 34, a permanent magnet rotor 40, an indicator 50 which can rotate with the motor, a drive circuit for driving the step motor, a ROM And a stopper 12 which stops the indicator at the zero position of the indicator when the indicator returns to the zero position, wherein the amplitude is set by a preset level at the end of each set time. Providing a zero return current to the feed exciting coil to form a full range rotating magnetic field that rotates in the zero return direction; and a portion of the magnetic field in which the zero return current separates the indicator from the stopper. And the step of increasing the preset level when forming. A step motor 4 having at least two feed excitation coils 24 and 34 and a permanent magnet rotor 40, the step motor and the rotatable indicator 50, and a control to generate a signal at a cycle rate A current signal generator, a drive circuit 70 for supplying a drive current to the field excitation coil in accordance with a signal from the control current signal generator, a ROM, and the indicator when the indicator returns to the zero position. In a method of operating an indicator with a stopper 12 for stopping at a zero position, a cosine wave signal and a sine wave signal for shifting a phase angle by a preset angle at the end of each set time are provided to the drive circuit, thereby returning to zero. Forming a rotating magnetic field in a full range rotating in the direction; and separating the indicator from the stopper by the cosine wave signal and the sine wave signal. And a step of increasing the cycle speed when the rotor magnetic portion is formed.