JP3515672B2 - Path switching method using stepping motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a permanent magnet type or composite type stepping motor (pulse motor, step motor) to efficiently perform path switching in a sheet conveying path of a sheet processing machine or the like. The present invention relates to a path switching method using the stepping motor.

[0002]

2. Description of the Related Art A flapper is conventionally driven by a solenoid (or a rotary solenoid) for switching the path of a paper sheet conveying path. The flapper is pulled in the exciting direction and restored by using a stress of a spring or the like. It is a thing. in this way,
When the drive voltage for exciting the solenoid becomes smaller, the response speed becomes slower, and the response speed changes depending on the drive voltage. Also, JP-A-57-39
In the case of the path switching mechanism using the stepping motor described in No. 487, the excitation phase is irrelevant when the flapper is rotated, and the photointerrupter for detecting the right position of the flapper is at the right rotation end. A photo interrupter for detecting the left end position of the flapper is provided at the left rotation end. By the way, the stepping motor that is usually used is a hybrid type or a variable reluctance type, in which the rotor is fixed so that the rotor falls to a stable point that matches the magnetic pole on the stator side, and an external force is applied while being excited. After that, even if the external force is removed, it will not return to its original position.

[0003]

Problems to be Solved by the Invention JP-A-57-3948
In the mechanism as shown in No. 7, it is necessary to detect whether or not the flapper has rotated to a position sufficient for switching the passage by the position detector, which complicates the circuit and the mechanism, and its parts. There is also a problem that the installation cost is high. Further, a solenoid of a type that attracts a plunger by excitation for switching a passage and a rotary solenoid that can rotate a shaft by excitation are generally used. However, these attraction forces are proportional to the square of the voltage applied to the solenoid, and there is a drawback that the operating speed becomes extremely slow when the power supply voltage decreases.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to make it possible to easily switch the path of paper sheets by efficiently driving the stepping motor, and at the same time, to obtain the stepping motor. It is to provide a path switching method using a stepping motor in which the response speed is constant by using the.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a paper path switching method using a stepping motor. The above object of the present invention is to drive a flapper by driving a stepping motor to rotate paper sheets. Of the basic excitation phase repeating unit when repeatedly exciting a plurality of types of windings so as to move the excitation position of the stator of the stepping motor in the rotation direction. The rotation angle for each step is determined so that the rotation ends in both directions come within the range, and the flapper is positioned at one end defined as the start point.
Further, a first stopper on the starting point end side is provided between the initial phase position, which is the excitation phase driven by the stepping motor drive circuit, and the excitation phase position adjacent to one step outside the rotation range, and the stepping motor drive circuit is A second stopper on the other end side of the flapper is provided inside the excitation position of the adjacent initial phase in which the combination of the excitation phases is equal to the initial phase in the rotation direction to the flapper when a drive pulse is input. Provided,
In the case of setting the initial position, a pulse of the basic excitation phase number is sent in the direction of the starting point to move the flapper to one end determined as the starting point, and then the excitation phase of the stepping motor is set to the initial phase. , The initial phase is set as the drive start position of the flapper, and the passage is switched.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A flapper is generally used for switching a paper sheet transport passage in a banknote processing machine or the like. In the present invention, however, a stepping motor is used to drive the flapper for passage switching. ing. 4 excitation phases of permanent magnet type stepping motor (4 phases in stator (A phase, * A
Phase, B phase, * B phase (where * A phase indicates the opposite phase of the A phase, * B phase indicates the opposite phase of the B phase, respectively)). By devising the drive angle driven by pulse input, the operating position of the stepping motor is always guaranteed, and the rotation angle of each stepping motor is fixed so that the rotation position is fixed by the excitation phase of the stepping motor. The flapper is made larger and stoppers are provided at both ends of the flapper to limit the rotation. As a result, 1 to 4 phases (A phase, * A phase, B phase) of the stepping motor
It is now possible to control the position of the flapper provided corresponding to the rotor shaft according to the excitation phase (phase, * B phase).

A preferred embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows the structure of a passage switching device to which the present invention is applied. A rotor shaft of a stepping motor 10 has a rotating shaft 20 for passage switching.
Are connected. The stepping motor 10 used in the present invention is a permanent magnet type stepping motor as shown in FIG. 2 (A), and the rotor 11 is composed of permanent magnets magnetized alternately in the circumferential direction in the N and S directions. There is a holding torque even when excited. The step angle is generally 45 ° or 90 ° for alnico magnets, and 7.5 °, 11.25 °, 15 ° for ferrite magnets.
18 ° is common, but in the present invention, the step angle is 7.
Use 5 °.

FIG. 3 shows a permanent magnet type stepping motor 10
FIG. 4 is a developed structural diagram of FIG. 1, in which a rotor shaft 12 is connected to both upper and lower side surfaces of a cylindrical rotor 11 in which N permanent magnets and S permanent magnets are alternately arranged. A stator for pulse excitation is arranged around the rotor 11, and the stator has a structure in which an upper stator 13 and a lower stator 14 are superposed in two stages. Since the upper stator 13 forms the A phase and the * A phase, the lower stator 14 forms the B phase and the * B phase, and the upper stator 13 and the lower stator 14 have the same configuration except for the phase of the teeth, so here, The upper stator 13 will be described. The upper stator 13 has an upper ring 131 and a lower ring 132 of a ring.
Cylindrical tooth materials 133 and 134 having saw-teeth-shaped stator teeth are vertically hung inside the inner ring portions of Nos. 1 and 132, respectively, and the stator teeth of the tooth materials 133 and 134 are arranged so as to mesh with each other. , The upper ring 131 and the lower ring 132 are stacked from above and below. Along with this, the tooth materials 133 and 134 of the upper ring 131 and the lower ring 132 that are overlapped with each other.
A coil 135 for forming the A phase and the * A phase is arranged around the. The upper stator 13 and the lower stator 14 are arranged around the rotor 11. The coil 138 of the lower stator 14 forms the B phase and the * B phase.

Since the permanent magnet type stepping motor has a structure in which the permanent magnet is mounted in a cylindrical shape as shown in FIG. 3, the magnetic poles cannot be made small and the step angle is large, and the basic excitation phase repeating unit. (In the two-phase excitation method, there are four types of A-B phase, * A-B phase, * A- * B phase, and A- * B phase.
It is a set of excitation phases. In the 1-2 phase excitation method, A phase, AB
Phase, B Phase, B- * A Phase, * A Phase, * A- * B Phase, * B
There are eight sets of excitation phases of the A- * B phase and the A- * B phase. The rotation angle corresponding to) is a rotation angle of 4 pulses in the two-phase excitation method, and thus the rotation angle is 7.5 ° × 4 = 30 °, which can be large and is sufficient for passage switching. Can be demonstrated.
The same applies to a composite type stepping motor as shown in FIG. 2 (B). Further, the variable rectance type stepping motor as shown in FIG. 2 (C) generally has a step angle of 15 °, but the rotor is made by processing soft iron into a gear shape and stops in an excited state. When an external force is applied to the rotor during holding, there is no return action due to repulsion between the magnetic poles, so in this case it is necessary to monitor the path switching position.

In the case of 1-2 phase excitation, the excitation of the rotating end portion becomes a single phase by setting the phases A to * B of the above 8 phases as basic excitation phase repeating units. Therefore, the stable holding range is narrower than that of 2-phase excitation.
The flapper stop position is stable and the power consumption is low.

A rotary shaft 20 connected to the stepping motor 10 is provided with flappers 21 and 22 for switching the conveyance path of the paper sheet 1 by swinging (rotating), and is attached to a chassis 31. An engagement piece 23 that engages with the stopper 30 is provided. The stopper 30 has a U-shape, and the engaging piece 23 freely moves in the U-shaped space so as to come into contact with the inside of the stop pieces 32 and 33 on both sides and stop. ing. Flappers 21 and 22
When the paper swings in the P1 direction,
And 22 and are conveyed as they are, and the flapper 21
When 22 and 22 are swung in the P2 direction, the leading end of the paper sheet 1 comes into contact with the flappers 21 and 22, and the conveyance path is switched downward.

The teeth of the stator of the stepping motor 10 are formed by tooth materials 133, 134 and 136, 137, and the number of teeth of each tooth material is 12 in this example. Therefore, it has 12 × 4 = 48 teeth as a whole,
At 0 ° ÷ 48 = 7.5 °, one step is 7.5 °. FIG. 4 is a developed view of the positional relationship of the teeth and the excitation relationship between the A phase, the * A phase, the B phase, and the * B phase. FIG. 4 (A) shows the case where currents are applied to the A phase and B phase, and FIG. 4 (B) shows the case where currents are applied to the B phase and * A phase.
The figure (C) shows the case where a current is passed through the * A phase and the * B phase, and the figure (D) shows the case where a current is passed through the * A phase and the * B phase.

FIG. 5 shows a drive circuit for exciting the stepping motor 10 in two phases. The decoder 50 (74)
The signal EN input to the HC 139) is a drive control signal for controlling the excitation / non-excitation of the stepping motor 10, and the signal RD input to the up / down counter 51 (74HC161A) is a rotation for instructing the rotation direction. It is a direction signal, and when the stepping motor 10 is set to "H" to specify up, the stepping motor 10 rotates in the CW direction,
Rotate in the CCW direction by setting to "L" and designating down. Further, the signal CK is a clock for step generation, the stepping motor 10 rotates in synchronization with the input of the clock CK, and is set by the input "A, B, C, D" in synchronization with the falling edge of the reset signal RS. The determined initial values are output to the outputs "QA, QB, QC, QD". Decoder 5
Depending on the combination of inputs "A, B", 0 is "L" for output YO if "0, 0", and "L" for output Y1 if "0, 1".
If "1,0", the output Y2 outputs "L", and if "1,1", the output Y3 outputs "L". Negative logic OR
The circuit 52 performs two-phase excitation so that two of the four circuits are “L” and is input to the PNP type transistor 53. The transistor 53 outputs a current when there is an “L” input, and turns on the PNP type transistor 54. When the transistor 54 is turned on, the corresponding phase of the stepping motor 10 is excited. When the A and B phases are excited, the stop position shown in FIG. 6 (corresponding to FIG. 4 (A)) is reached, and when the B phase and * A phase are excited, the free position shown in FIG. 7 (corresponding to FIG. 4 (B)) is obtained. , * A phase and * B
When the phases are excited, the free position shown in FIG.
(C)). Moreover, when the A phase and the * B phase are excited, FIG.
Is the stop position (corresponding to FIG. 4D). A reset signal RS is input to the up / down counter 51, and when the reset signal RS is input, the counter 51 is loaded with an initial value 0 and 0 is output from all the outputs QA to QD. Phases A and B are excited.

In such a structure, first the flapper 2
The moving rotation range of 1 and 22 is set to the stepping motor 10
Set within the basic phase of 2-phase excitation. In this embodiment, 7.5
.Degree. / Step is selected, whereby the allowable rotation angle of the flappers 21 and 22 is secured at 7.5.degree..times.3 = 22.5.degree .. The combination of phases excited in the movable range of the flappers 21 and 22 is AB phase excitation, * AB phase excitation,
If two or more of * A- * B phase excitation and A- * B phase excitation exist, two stable positions of the rotor 11 exist, and therefore, the identification cannot be continued. FIG. 11 shows
It shows that the north and south poles of the rotor and the stator are attracted to each other, and the second stable position is reached.

First, the initial position as shown in FIG. 6 is set after the power is turned on. That is, the positions of the rotor 11 and the positions of the flappers 21, 22 determined by the polarities of the excitation phase teeth are matched. When the power is turned on, it is not known at which exciting position the axial position of the rotor 11 is located. Therefore, the axial position of the rotor 11 is set to this exciting position. In this case, unconditionally input the clock CK in the CCW direction (negative direction)
A pulse is sent (see time points t1 to t2 in FIG. 10). As a result, the flappers 21, 22 are pulled toward the left end (or the right end) and stop. In this way, the rotor 11 is fixed by the stopper, and (a), (b), (c) of FIG.
(D) is in the excited state. In addition, (a) of FIG.
(D) shows the excitation phase on the stator side when a pulse is sent unconditionally without considering the initial position. At this stage, there is no guarantee that the excitation phase is also at the left end, but (b) is 1
Since the magnetic poles attracting each other exist at the positions shifted by the phase, the reset signal RS is input on the drive circuit side to reset the excitation phase so that the excitation phase on the stator side comes to the magnetic pole position of the rotor 11. Matching (time point t2 in FIG. 10). At this time, the rotor 11 is fixed at a regular angle, and the flapper is in the state of (e) in FIG. 12A at the starting point.

Next, when the rotation direction signal RD in the CW direction (forward direction) is input and three pulses of the clock CK are sent (see time points t2 to t3 in FIG. 10), the rotor 11 is moved by three pulses. Turn to match the position and excitation phase,
After that, it starts moving in synchronization with the input pulse. After that, the number of pulses of the clock CK and the direction of the rotation direction signal RD are controlled so as not to deviate from the allowable movement range. After sending these three pulses, the position of the teeth of the rotor 11 is at the end of the allowable movement range in the CW direction. In this state, the excitation phase of the stepping motor 10 is fixed with each phase being energized, and the path of the conveyed paper sheet is switched. CC when switching passages
Input the rotation direction signal RD in the W direction and set the clock CK to 3
By sending the pulse, the position where the rotor 11 is rotated comes to the end in the CCW direction.

There is a stopper as shown in FIG.
Only one set of excitation phases of phase, * A-B phase, * A- * B phase, and A- * B phase has an excitation range, and the flapper rotation range is limited. Even if the flapper tries to move inward due to disturbance, the rotor tries to find a stable magnetic path. Figure 1
The excitation on the stator side of No. 1 is the same as in FIG. 6 and shows the initial phase. Normally, the position indicated by the broken line in FIG. 11 is the most stable point of the rotor, but even if it is forcibly brought to the position indicated by the solid line, half the magnetic poles of N and S will attract each other as shown in the figure. It shows that there is a stable point. This second
If there is a flapper at a position other than the stable point of the above, it acts so as to return to the most stable position shown by the dotted line in the figure.

Further, FIG. 12 (A) shows a state in which initial setting is carried out, and (a), (c), ( In (d), the excited state after the circuit is reset is shown in (e). FIG. 12B is a diagram for explaining the case of (A) and (B). In this case, the flapper may be stopped by the stopper after the magnetic field of the stator is moved counterclockwise by four pulses. Without (a position indicated by a wavy line), a stable magnetic circuit can be formed inside by one step, so that the position is indicated by a solid line. By resetting the drive circuit even at the positions (a), (b), (c), and (d), the position becomes the position (c) in FIG. 12A. The flapper will be held stably.

Although an example of driving the permanent magnet type stepping motor by two-phase excitation has been described above, the composite type stepping motor can be applied in a similar manner although there is some problem in terms of price. As for the drive system, the two-phase excitation system has been described above, but the 1-2-phase excitation system is also applicable. According to the 1-2 phase excitation method, A near the stopper
Since the phase or the B phase is excited independently, there is an advantage that the both ends, particularly, the starting point is stabilized. Further, although the stepping motor is used for switching the passage in the above description, it is needless to say that the stepping motor can also be used for an actuator that rotates a small angle.

[0020]

As described above, according to the path switching method using the stepping motor of the present invention, since the flapper is driven by the stepping motor, there is no response delay even if the supply power voltage varies. . Further, since the passage switching range is limited to one cycle of four excitation phases, the position of the flapper can be specified by the excitation phase, and the position detection sensor can be omitted. Therefore, it is possible to provide a low-cost passage switching device.

Compared with the conventional solenoid type path switching device, the rotation is dependent only on the speed of phase movement according to the clock, the response speed is fast, and the rotational position of the flapper is controlled by pulses. Therefore, unlike the passage switching using the solenoid, it does not stop by hitting the stopper, so it can be used at high speed without bouncing that occurs when hitting the stopper when switching the passage.

The stepping motor is inexpensive and can be manufactured at a low cost. The stable point of the rotor of the stepping motor is within the switching range, and it is always held at the moving end by the excitation of the stator, so that a sensor for confirming the operation is unnecessary.

[Brief description of drawings]

FIG. 1 is a perspective structural view showing an example of a passage switching device to which the present invention is applied.

FIG. 2 is a connection diagram showing structural examples of various stepping motors.

FIG. 3 is a development view showing a structural example of a permanent magnet type stepping motor.

FIG. 4 is a diagram for explaining two-phase excitation of a stator.

FIG. 5 is a block diagram showing an example of a drive circuit of a stepping motor.

FIG. 6 is a diagram for explaining the operation of the stepping motor.

FIG. 7 is a diagram for explaining the operation of the stepping motor.

FIG. 8 is a diagram for explaining the operation of the stepping motor.

FIG. 9 is a diagram for explaining the operation of the stepping motor.

FIG. 10 is a time chart showing an operation example of a stepping motor.

FIG. 11 is a diagram for explaining a state in which the N pole and the S pole are attracted to each other and are in the second stable position.

FIG. 12 is a diagram for explaining the operation of the stepping motor.

[Explanation of symbols]

1 paper sheets 10 Stepping motor 20 rotation axis 21, 22 flapper 23 Engaging piece 30 stopper

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Claims (3)

(57) [Claims] 1. A stepper motor is driven to rotate a flapper to switch the path of paper sheets,
In order to move the excitation position of the stator of the stepping motor in the rotation direction, when the plural kinds of windings are repeatedly excited, the rotation ends in both directions come within the rotation angle range by the excitation phase movement of the basic excitation phase repetition unit. The rotation angle of the flapper for each step is determined in advance, and the flapper is positioned at one end defined as the starting point.
Further, a first stopper on the starting point end side is provided between the initial phase position, which is the excitation phase driven by the stepping motor drive circuit, and the excitation phase position adjacent to one step outside the rotation range, and the stepping motor drive circuit is A second stopper on the other end side of the flapper is provided inside the excitation position of the adjacent initial phase in which the combination of the excitation phases is equal to the initial phase in the rotation direction to the flapper when a drive pulse is input. Provided,
In the case of setting the initial position, a pulse of the basic excitation phase number is sent in the direction of the starting point to move the flapper to one end determined as the starting point, and then the excitation phase of the stepping motor is set to the initial phase. A path switching method using a stepping motor, wherein the path is switched using the initial phase as a drive start position of the flapper. 2. The path switching method using a stepping motor according to claim 1, wherein the stepping motor is a permanent magnet type or a composite type. 3. A path switching method using a stepping motor according to claim 1, wherein the stepping motor is driven by a two-phase excitation method or a 1-2-phase excitation method.