JPS614458A - Stepwise feeding actuator - Google Patents

Abstract

PURPOSE:To obtain an actuator capable of stepwisely feeding in small size and high accuracy by forming the operation corresponding to the teeth of a step motor by a sensor and a controller. CONSTITUTION:A coil movable type linear actuator 10 has a permanent magnet 12 and pole pieces 16 on the inner surface of a stator 11, and coils 15 disposed in the intermediate gaps. A movable unit 13 directly coupled with the coils 15 is supported by slide bearings 14 and laterally moved. A sensor 3 is disposed oppositely to the unit 13, the position of the unit 13 is detected, and the detection signal is applied to a signal processor 6. The sensor 3 generates different 2-phase outputs A, B of 90 deg., the processor 6 forms a reverse conversion signal and applies a voltage command signal Vc to a voltage controller 5 on the basis of one of the signal selected by a command generator 7 by the voltage instructing circuit 5. The controller 5 controls the voltage of the coil 15 to stepwisely feed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a step feed actuator device that can move the position in steps, and in particular,
The present invention relates to a small and highly accurate stamp feeding actuator device.

[Background of the invention]

The recent development of the information industry has been remarkable.

In particular, OA (Qffice Automation)
Equipment is rapidly progressing in response to the need for labor and resource savings.

Along with this, there is a strong demand for actuator devices used in OA equipment to be smaller, faster, and more accurate.

For example, as the density of FDDs increases, it is essential for actuator devices that drive heads of floppy disks (FDDs) to reduce track spacing and increase stopping speed.

Conventionally, step motors have been widely used to drive the head, but as is well known, in order to shorten the interval between step feeds, the number of teeth on the iron core of the step motor must be increased.

However, if you do this, the pitch of the teeth will decrease by 1.
F, -, -7 □ 1781,91.2 ke Therefore, 7~Ai also gets worse.

Furthermore, when the pitch of the teeth becomes small, torque generation and reluctance change related to the slope of the torque become small, so there is a drawback that the generated torque also becomes small.

In response to this, a method has recently been announced in which a feedback signal is recorded on the disk surface of the FDD using a movable coil actuator, and this signal is used to apply the servo, but it is not compatible with the disk method. There is no gender,
There was a drawback that it was difficult to use as a general-purpose actuator device.

[Purpose of the invention]

An object of the present invention is to provide a step feed actuator device that is compact and capable of highly accurate step feed.

[Summary of the invention]

The first aspect of the step feed actuator device of the present invention includes an actuator that has a fixed part and a movable part, and a sensor that generates outputs for each phase, facing the movable part. In this case, the sensor has a two-phase output A.

a signal processing circuit that processes signals a and b related to the sensor outputs A and B, and inversely converted signals a and b based on the sensor outputs A and B; a voltage command circuit that sequentially selects one of the signals a, b, a, and b based on the position command to generate a voltage command; and a voltage control circuit that controls the voltage of the actuator based on the voltage command. It is constructed by providing the following.

Similarly, the second invention has an actuator including a fixed part and a movable part, and a sensor that generates all the outputs of each phase, facing the movable part.
A sensor that generates n-phase (n≧3) pressure is used as the sensor.
a voltage command circuit that sequentially selects one of the n signals based on the position command to generate a voltage command; and a voltage control circuit that controls the voltage of the actuator based on the voltage command. It is configured by having the following.

More detailed information is as follows.

According to the present invention, an operation corresponding to the teeth of a step motor is achieved using a sensor and a control circuit.

That is, a sensor that generates a number of outputs corresponding to the number of steps of the step motor, for example, a two-phase output A, B (for example, for a 1.8° step motor, a sensor that generates a number of outputs corresponding to the number of steps of the step motor, 360/1.8 A two-phase sensor (X 1/4 = 50 pulses/rotation) is provided opposite the movable part of the actuator, and the signals a and b related to the outputs A and B of this sensor are inversely converted to the output power A and B. One of the signals a and b is sequentially switched in synchronization with the command pulse.

Then, the voltage applied to the actuator is controlled in accordance with the selected sensor output signal example.

Since the step operation is based on a sensor signal, the torque generating mechanism of the actuator does not require teeth unlike a step motor, and the sensor and control circuit perform the action of the teeth of the step motor.

The block diagram of FIG. 1 shows the basic configuration of a step feed actuator device based on the above idea.

In the figure, IA is the fixed part of the actuator, 2A is the movable part of the actuator, 3A is the movable part of the actuator, and two-phase output A with a 90 degree phase difference is installed facing the two people.
6A is a sensor that generates signals a, b, and their inversely converted signal a based on the two-phase outputs A and B of the sensor 3A.
, b, 7A is a command generation circuit, and 5A is a signal processing circuit for generating commands θ9. θr (in addition, θ
, is a pulse train related to the number of steps, and θ2 is a command for the moving direction. ), the voltage command circuit 4A sequentially selects only one of the signals a, b, a, and b from the signal processing circuit 6A and generates the i-pressure command signal vc based on the selected signal. 'Based on the voltage command signal v0, the actuator's fixed part IA or OK? This is a voltage control circuit that controls the voltage V applied to two moving parts.

Due to the above configuration, the two-phase output A of the sensor 3A is obtained.

The direction and magnitude of the voltage applied to the actuator are determined by the signals a and b caused by B and the inversely converted signals a and b.

FIG. 2 is an explanatory diagram of the relationship between the sensor output and basic operation, showing the phase relationship of each signal a, b, a, and b.
At the same time, each signal a, b, a.

It shows the phase of the actuator coil voltage (■) based on b.

In Figure 2, a positive voltage causes a positive current to flow and generates a rightward force, and a negative voltage causes a leftward current to flow and generate a leftward force. Then, in the area of position (a) to the left of point al, it always moves to the right, and in the area of position ←) to the right of point al, it always moves to the left, and stops at point 81.

Further, in the area of position C9 on the E side of point a2 in the figure, it moves rightward and stops at point a2.

That is, when the signal a is based on the output A of the sensor 3A, the point al l a2 +... is a stable point, and the motor always stops at this position.

Similarly, the stable points are point al for the inversely transformed signal a, point b1 for the signal, and point b1 for the inversely transformed signal.

From this diagram, when moving the actuator to the right,
As shown in the figure, the signal is aI1) −+,
13-+ l) -+ a. Conversely, when moving to the left, the wave source is switched as shown by the wave source arrow in the figure, a→b→a→b→a.

That is, based on No. 46 a, if the movable part 2A is at the position of point al, then when moving to the next signal, '
rl [Pressure command V. increases from zero at point a1 to V.

As a result, the movable part 2A moves rightward and stops at point b1.Next, when moving to the inverse conversion signal a, the voltage command v0 increases from zero to vo again, and the movable part The two people move to the right and stop at point al.

By repeating this motion, move a, -+b to the right.
, -+a, -+b, -4329 in the order of any number of steps.

The same applies to the left direction.

Therefore, the actuator may be anything that changes the direction of the force depending on the direction of the heavy pressure, and generally includes electromagnetic machines. For example, a DC motor is used in a rotating machine, and a voice coil is used in a linear actuator.

There are still sensors such as rotary encoders for rotating machines and linear encoders for linear actuators.

As can be seen from Fig. 2, there are four stopping points in one cycle: al + aI r bl r bl.
It is obvious that their stopping accuracy depends on the sensor accuracy.

Also, in order to reduce the error regarding the load at the stopping point,
The sensor waveform may be shaped into a trapezoid.

Further, the sensor output may be of n phases (n≧3) including phases related to the three-phase outputs A, B, and C.

[Embodiments of the invention]

Embodiments of the step feed actuator device according to the present invention will be described with reference to FIGS. 3 to 6.

FIG. 3 is a schematic configuration diagram of a step feed actuator device according to an embodiment of the present invention, and FIG. 4 is a time chart diagram illustrating its operation.

According to this embodiment, an actuator consisting of a fixed part and a movable part is provided, and a Yanosa is provided opposite to the movable part to generate an output of each phase, and two sensors are used as sensors for the actuator. A sensor that generates phase outputs A and B is provided, and signals a and b related to B and inversely converted signals a and ゛■ based on the sensor outputs A and B are processed to the sensor output. a signal processing circuit; a voltage command circuit that sequentially selects one of the signals a, b, a, and b based on the position command to generate a voltage command; and a voltage command circuit that controls the voltage of the actuator based on the voltage command. This configuration includes a voltage control circuit.

That is, in FIG. 3, 10 is a coil movable linear actuator, and a permanent magnet 1 is attached to the inner surface of a fixed part 11.
2 and a magnetic pole piece 16.

Then, a coil 15 is arranged in the gap between these,
Thrust is generated by the coil current and magnetic flux.

The movable part 13 directly connected to the coil 15 is supported by a sliding bearing 14 and can move left and right.

Therefore, in order to detect the position of the movable part 13,
The sensor 3 is disposed facing the movable part 13.

This sensor 3 is a magnetoresistive element, and the movable part 13
The position can be measured by the increase or decrease in the magnetic field of the magnetic pole of the magnetic paint 17 applied to the surface.

Therefore, the movable part 13 of the linear actuator 10 in this configuration can linearly move left and right by applying positive and negative voltages to the coil 15 and, as a result, causing positive and negative currents to flow. , In response to this linear movement, the sensor 3 generates two-phase outputs A and B that are 90 degrees out of phase.

6 generates the previously mentioned signals a, b and inversely converted signals a, b using analog inverters 61 and 62 based on the two-phase outputs A and B of the sensor 3, and converts these signals a, b, a ,b
This is a signal processing circuit that outputs .

7 is a command generation circuit; 5 is a signal a from the signal processing circuit 6 based on the command from the command generation circuit 7;

Only one is selected from b, a, and b, and the voltage command signal V is determined based on it. This is a voltage command circuit that generates.

The voltage command circuit 5 is composed of a U, P/I) OWN counter 52 and an analog multiplexer 51. The pulse train command θ related to the pulse train signal that commands the direction command θ makes U
It performs a P count or a DOWN count and generates an address signal Do + DI.

Further, the analog multiplexer 51 outputs the address signal D
Based on the address signals Do, D+, only one of the four switches is closed, for example, based on the address signals Do, D+
Accordingly, the voltage command signal V. is the signal a-+l)-* a
-*b.

4 is a voltage control circuit that controls the voltage of the coil 15.

In other words, 21 is a DC power supply, 23 to 26 are transistors connected in an H type, and the transistors 23.2
By turning on 6 or 24.25, the direction of the coil voltage is controlled, and the magnitude of the coil voltage is controlled by the energization rate.

8 is a predrive circuit that generates firing signals for the transistors 23 to 26 groups based on the voltage command signal v0.

In this predrive circuit 8, the voltage command signal v6 is the triangular wave signal S from the triangular wave generating circuit 9.

, and is matched by the comparator 29.

The triangular wave generation circuit 9 includes two amplifiers 30 and 31, and generates a triangular wave by charging and discharging a capacitor 35.

A duty output Sd is obtained by combining the triangular wave signal St and the voltage command signal v6.

The signal related to this duty output Sa is output from the AND circuit 27.2.
8, and this AND circuit 27.28
The other input is a voltage command signal V. converter 3
4, it is determined whether the direction is positive or negative, and this is inputted to the AND circuit 27 and inputted to the AND circuit 28 through the NOT circuit 33.

Therefore, when the direction is forward, the transistors 23 and 26 are turned on, and when the direction is reversed, the transistors 25 and 244 are turned on.
is turned on.

With the above configuration, following the command of the command generation circuit 7,
The linear actuator 10 is capable of step feeding.

This will be explained in more detail with reference to the time chart shown in FIG.

In the same figure, θ2. θ, as described above, is the command generation circuit 7
In the command, θ is a pulse train command that commands the number of step feeds, θ2 is a command for the moving direction, and 1 in the figure indicates the right direction.
Zero is to the left.

In addition, S is the signal name selected by the voltage command circuit 5, v is the voltage command signal related to the output of the voltage command circuit 5, and the voltage v1 applied to the coil of the actuator is pulse width modulated based on V. As a result, the coil current & of the actuator also becomes approximately equal to the voltage command v8.

N is the speed of the movable part 13 of the linear actuator 10,
X indicates the position of the movable part 13.

That is, from time to to t1, signal a related to the A-phase output from sensor 3 is selected and stopped at a stable point of signal a.

Next, at time tl, when the pulse signal P1 related to the pulse train command θ is input, the signal related to the output B from the sensor 3 is selected, the voltage command signal V becomes a positive value, and the coil voltage increases. When the voltage becomes positive, the coil current begins to flow and the movable part 13 begins to move.

Next, when pulse signals P2 to P4 are input at times t2 to t4, the sensor 3 selects each signal a, b, and a in this order, and the movable part 13 moves as indicated by X in the figure. be.

Next, after a certain period of time from time t4 to t5, the movable part 13 stops. At this time, the movable part 13 has moved four steps to the right.

Next, in the middle of time t4 to t5, the movement direction command θ is 0.
When the pulse signal P5 is input at time t5, the sensor 3
, signals a to b are selected, and the voltage command signal V. becomes negative, the coil voltage becomes negative, the coil current also becomes reversed, and the movable part 13 also begins to move to the left.

Then, at time t6. When the pulse signal P6+P7 is input at t7, the sensor 3 sequentially selects signals a and b, and at time t7.
It will stop after a certain amount of time has elapsed.

As a result, it stops after moving three steps to the left.

Although this embodiment has been described using a two-phase sensor as an example, the concept of the present invention can also be effectively applied to a multi-phase sensor in order to increase the resolution of the sensor.

Next, the case of the multiphase sensor will be explained.

That is, FIG. 5 is a schematic configuration diagram of a step feed actuator device according to another embodiment of the present invention, and FIG. 6 is a relationship between sensor output and basic operation, which also shows the phase relationship of each signal. It is an explanatory diagram.

According to this embodiment, an actuator consisting of a fixed part and a movable part, and a sensor that generates an output of each phase are provided facing the movable part. A sensor that generates n-phase (n≧3) outputs is provided, and n signals related to each of the outputs and n inversely converted signals based on the sensor outputs are provided. a signal processing circuit to be processed, a voltage command circuit that sequentially selects one of the 2n signals based on the position command to generate a voltage command, and a voltage that controls the voltage of the actuator based on the voltage command. It is configured to include a control circuit, and is related to n-3, that is, three phases.

In the figure, the same reference numerals as in FIG. 3 according to the previous embodiment are
The equivalents are shown, 3-1 is a three-phase sensor, 5-1 is a voltage command circuit, 51-1 is an UP/DOWN counter, and 6-
1 is a signal processing circuit, and 61 to 63 are analog inverters.

That is, as shown in Figure tx5.6, this embodiment is a case of a three-phase sensor in which the human phase, B phase, and C phase are separated by 120 degrees, each of which is multiphase. In the case of a 3-phase sensor, 3-phase signals a, b, c related to outputs A, B, and C of sensor 3-1
If we simultaneously use the inverted signals a, b, and c related to the inverted signals of the outputs A, B, and C of the sensor 3-1, we get 6.
Step feeding is possible every 0 degrees.

In Figure 6, the point aI + bI r CI is the physiognomy.

This is the stable point of the signals a, b, and c corresponding to the B phase and C phase,
The point a1 + bl + C1 is the stable point of the signals a, b, and c corresponding to the A phase, B phase, and C phase.

Step feeding every 60 degrees can be performed by switching in the order of a→c-+b→a→C→b→a, as shown by the solid line arrows in FIG.

Therefore, in this embodiment, each of the three-phase signals al
b, c, a, b, ' are used at the same time, but in the case of this three-phase sensor, if only the signals a, b, and c related to the outputs A, B, and C are used, 120 This can be a step feed actuator device that can perform step feed at each step.

That is, in this case, the signal processing circuit 6-1 shown in FIG. 5 is not provided, and the six switches in the UP/DOWN counter 51-1 are connected to the signals a and b.

By configuring only three switches related to C,
Assuming that the step feed is every 120 degrees,
3.

In these cases, even when the polyphase is three or more phases, the configuration can be changed in the same manner and the same effect can be expected.

〔Effect of the invention〕

According to the present invention, an actuator device capable of step feeding can be realized using a sensor and a control circuit without providing teeth on an iron core or the like.

Therefore, by using a highly accurate sensor, an actuator device with an extremely fine step length can be realized.

Further, as the torque generating mechanism, a general one such as a DC machine or a voice coil can be used, and miniaturization and high efficiency can be achieved.

Furthermore, by changing the pitch of the sensor, the number of steps can be changed, and the mass productivity and versatility of the actuator device can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of a step feed actuator device according to the present invention. FIG. 2 is an explanatory diagram of the relationship between the sensor output and basic operation, also showing the phase relationship of each signal. FIG. 3 is a schematic configuration diagram of a step feed actuator device according to an embodiment of the present invention. FIG. 4 is a time chart diagram explaining its operation, FIG. 5 is a schematic configuration diagram of a step feed actuator device according to another embodiment, and FIG. 6 also shows the phase relationship of each signal.
FIG. 3 is an explanatory diagram of the relationship between sensor output and basic operation. 3.3-1...sensor, 4...voltage control circuit, 5,
5-1... Voltage command circuit, 6.6-1... Signal processing circuit, 7... Command generation circuit, 8... Predrive circuit, 9... Triangular wave generation circuit, 10. ...Coil movable linear actuator, 11...Fixed part, 12...
- Permanent magnet, 13... Moving part, 14... Sliding bearing, 15... Coil, 16... Magnetic pole piece, 17... Magnetic paint, 21... DC power supply, 23-26...・Transistor, 27.28...AND circuit, 29...Comparator, 30-31...Amplifier, 33...NOT circuit,
, 3'4... comparator, 35... con f7f,
51.5l-1-UP/DOWN cow 7ri, 52...
Analog multiplexer, 61-+-63...analog inverter.

Claims (1)

[Scope of Claims] 1. An actuator consisting of a fixed part and a movable part, and a sensor that is provided opposite to the movable part and generates an output of each phase, the sensor being a two-phase output. A sensor that generates signals A and B is provided, and signals a and b related to the sensor outputs A and B, and the sensor output A
, B, and a signal processing circuit that processes inversely transformed signals a, b based on
A step feed actuator device comprising: a voltage command circuit that sequentially selects one of the voltage commands to generate a voltage command; and a voltage control circuit that controls the voltage of an actuator based on the voltage command. . 2. An actuator consisting of a fixed part and a movable part, and a sensor that is placed opposite the movable part and generates an output of each phase.
n≧3), a voltage command circuit that sequentially selects one of the n signals based on the position command to generate a voltage command; 1. A step feed actuator device comprising: a voltage control circuit for controlling the voltage of an actuator based on the voltage control circuit; 3. In the product described in claim 2, the n-phase (
a signal processing circuit that processes n signals related to each sensor output that generates an output of n≧3) and n inversely converted signals based on each sensor;
A step feed actuator is a step feed actuator that includes a voltage command circuit that sequentially selects one of the signals to generate a voltage command, and a voltage control circuit that controls the voltage of the actuator based on the voltage command. Device.