JPH0736480Y2 - Carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a transfer device for transferring an object to be transferred to a predetermined position.

[Prior Art] Conventionally, a carrier device using an AC motor as a drive source is known, and most of them are controlled by ON / OFF control of the AC motor by a signal from a limit switch operated by contact of a carrier object. It is provided with a simple control circuit for stopping the conveyed object at a desired position. In this type of transfer device, advanced and complicated speed / position feedback control of the AC motor and transfer direction switching control are required to accurately stop the transferred object, increasing the number of parts and manufacturing cost. Such a problem occurs.

Therefore, a conveyance device using a stepping motor instead of the AC motor has been considered. That is, since the stepping motor is easy to control the speed / position and to switch the rotation direction and the control circuit can be easily manufactured, it is used in a paper transport device or a carriage transport device of a printer.

[Problems to be solved by the invention] However, the stepping motor can be accurately controlled in position and speed at a light load or at low / medium speed rotation, and thus is used as a carrier device for carrying lightweight objects or low / medium speed conveyors. Although it can be used, it is easy to get out of step when the load is large or when it is rotated at high speed. Therefore, it is difficult to use it for a conveyor device for carrying heavy objects or high speed, such as a belt conveyor.

Therefore, the present invention has been made for the purpose of providing a carrying device capable of carrying a heavy object or a high speed object with high accuracy by using a stepping motor.

[Means for Solving the Problems] The gist of the present invention is to provide a carrying means for carrying an object to a predetermined position, a stepping motor for driving the carrying means, and a stepping motor built in the stepping motor. Step detection means for detecting the step motion of the stepping motor and outputting a detection signal, reference signal creating means for creating a reference signal for determining the step motion timing of the stepping motor, and the stepping operation based on the created reference signal. Energizing means for energizing each phase of the motor in a predetermined circulation order, phase difference detecting means for detecting a phase difference between the reference signal of the reference signal creating means and the detection signal of the step motion detecting means, and the phase difference detecting means. Peak value detecting means for detecting the peak value of the phase difference detected by the means, and the energizing hand based on the peak value detected by the peak value detecting means. In conveying apparatus characterized by and a control means for controlling the amount of energization.

[Operation] In the carrier device of the present invention configured as described above,
The energizing means energizes each phase of the stepping motor in a predetermined circulation order based on the reference signal created by the reference signal creating means. Then, the stepping motor rotates to drive the conveying means, and the floor movement detecting means detects the floor movement of the stepping motor and outputs a detection signal.

Then, the phase difference detecting means detects the phase difference between the reference signal of the reference signal generating means and the detection signal of the step detection means, and the peak value detecting means detects the peak value of the phase difference detected by the phase difference detecting means. To detect. Further, the control means controls the energization amount of the energizing means based on the peak value detected by the peak value detecting means.

Here, when the weight of the conveyed object conveyed by the conveying means is large, or when high-speed conveyance is performed, the output torque of the stepping motor is insufficient with respect to the load, and the stepping motor is moved more than the reference signal. (Rotation phase) is delayed.

Then, since the phase difference detected by the phase difference detecting means increases and the peak value of the phase difference detected by the peak value detecting means also increases, the energizing amount of the energizing means is increased by the control means. Therefore, the output torque of the stepping motor is increased, and the stepping motor raises the carrying speed of the carrying means to a predetermined set speed without stepping out.

Then, when the conveyance speed increases, the difference between the reference signal and the stepping motion of the stepping motor decreases, and the phase difference detected by the phase difference detecting means also decreases. However, the control means uses the peak value detecting means. Since the energization amount of the energizing means is continuously controlled based on the peak value of the phase difference detected by, the energizing current to each phase of the stepping motor is maintained at the increased level. Therefore, after that, even when the stepping motor is decelerated to stop the transported object, a sufficient current corresponding to the inertial force of the transported object is continuously supplied to each phase of the stepping motor. The transported object can be stopped quickly and accurately.

In other words, the energization current to each phase of the stepping motor is set according to the maximum value of the load generated in the process of transporting the transported object, so the stepping motor must lose the load at the start of transportation. Accelerate the transported object without stopping, and stop the transported object without losing inertial force at the end of the transportation. In all situations, move steplessly (that is, in synchronization with the reference signal). .

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

1 (A) and 1 (B) are a front view and a plan view of a carrier device to which the present invention is applied, and FIG. 2 is a block diagram showing a configuration of a controller of the carrier device.

As shown in the figure, the carrying device 1 includes a stepping motor 3
A drive pulley 5 fitted to the drive shaft 3a of the stepping motor 3, a driven pulley 7 rotatably arranged at the end opposite to the stepping motor 3, a drive pulley 5 and a driven pulley 7. A main part is a timing belt 9 that is looped around and circulated around the carriage, a carriage 11 that is attached to the timing belt 9 for mounting an object to be conveyed (not shown), and a support frame 13 to which these respective parts 3 to 11 are attached. Is configured as.

In this embodiment, the timing belt 9 and the carriage
Reference numeral 11 corresponds to the transportation means.

The stepping motor 3 is a so-called claw pole PM type (inductor permanent magnet type) four-phase stepping motor, and is a rotor having a cylindrical shape and N poles and S poles alternately arranged in the circumferential direction (not shown). ) And a large number of comb teeth acting as claw poles have two rings protruding from the upper surface or the lower surface, the two rings are stacked vertically so that the comb teeth mesh with each other, and the coils are arranged on the outer circumference of each ring. It is provided with a stator (not shown) formed by being wound, a part of the comb teeth is cut out, and the magnetic sensor 15 is arranged there to detect the rotor magnetic pole. The stepping motor 3 is drive-controlled by the control unit 20.

In the present embodiment, the magnetic sensor 15 corresponds to the floor movement detecting means.

As shown in FIG. 2, the control unit 20 includes a control circuit 22 and an operation panel 24.

The control circuit 22 includes a well-known stabilized power supply 30 and a voltage-frequency converter (hereinafter, V / F) that creates a clock pulse (square wave signal) CLK having a predetermined frequency according to the voltage input from the stabilized power supply 30. 32), a distribution circuit 34 that creates drive pulses φ1 to φ4 based on the clock pulse CLK input from the V / F converter 32, and each phase winding of the stepping motor 3 based on the drive pulses φ1 to φ4. A drive circuit 36 for energizing L, a counter 40 for counting magnetic pole detection pulses P input from the magnetic sensor 15 via the waveform shaping circuit 38, a magnetic pole detection pulse P and a clock pulse CLK.
And a phase comparator 42 that creates a voltage signal Vdet corresponding to the phase difference between them and an integrating circuit 46 that integrates the voltage Vdet input from the phase comparator 42 through the noise removal filter 44. A peak hold circuit 47 that holds the peak level of the voltage ΔV input from the integration circuit 46 and a drive power supply 48 that supplies power to the drive circuit 36 are mainly configured.

In this embodiment, the V / F converter 32 corresponds to the reference signal creating means, and the distribution circuit 34 and the drive circuit 36 correspond to the energizing means. Further, the phase comparator 42 and the peak hold circuit 47 correspond to the phase difference detecting means and the peak value detecting means, respectively, and the drive power supply 48 corresponds to the controlling means.

On the operation panel 24, a start switch 50 and a digital switch 52 for presetting a transport distance (stop position)
And a speed setting switch 54 for setting the carrying speed, that is, the rotation speed of the stepping motor 3 to either high or low.
And a forward / reverse changeover switch 56.

The stabilized power supply 30 outputs a high or low reference voltage to the V / F converter 32 according to the output level of the speed setting switch 54, that is, according to the High level or the Low level. The V / F converter 32 creates a clock pulse CLK having a high or low frequency according to the reference voltage.

The distribution circuit 34 is composed of logic elements, and distributes the input serial clock pulse CLK in a predetermined forward (CW) or reverse (CCW) sequence to energize each phase winding L of the stepping motor 3. Drive pulses φ1 to φ4 that determine timing are created and distributed. This preparation / distribution is started when the signal S1 is input from the start switch 50 and stopped when the count completion signal S2 is input from the counter 40.

The drive circuit 36 is mainly composed of a power transistor array Tr, and each power transistor Tr is a distribution circuit.
By turning on and off by the drive pulses φ1 to φ4 from 34, the phase winding L of the stepping motor 3 is energized. The drive voltage VDD supplied from the drive power source 48 is applied to the power transistor array Tr and the phase winding L, and the current flowing through the phase winding L according to the rise or fall of the drive voltage VDD, and therefore the stepping motor. The output torque of 3 is
It is designed to increase or decrease.

The counter 40 counts the magnetic pole detection pulses P input from the waveform shaping circuit 38, and the count value is the digital switch 52.
When the preset work transport distance is reached (count up), or when it reaches zero (zero count),
The counting completion signal S2 is output to the distribution circuit 34. In this embodiment, the counter 40 is preset to count down.

The drive power supply 48 includes a reference voltage power supply 48a that creates a reference voltage VST to be supplied to the drive circuit 36, and an integration circuit 46 for the reference voltage VST.
The peak hold circuit 47 is provided with an adder 48b that outputs a drive voltage VDD to which an input voltage ΔV is added, and a current buffer 48c that amplifies a current and outputs the input voltage from the adder 48b as it is. .

Next, the operation of the carrier device 1 will be described.

In the carrying device 1, the operation panel 24 is used to set the carrying distance, the carrying speed high / low, and the forward / reverse rotation, and the start switch 50
When is pressed, the conveyance of the conveyed object is started. That is,
The stepping motor 3 rotates in synchronism with the clock pulse CLK, the conveyed object is conveyed, and the stepping (step operation) of the stepping motor 3 is input to the counter 40 as the magnetic pole detection pulse P, and the counter 40 detects the magnetic pole detection pulse. P
Is counted.

At this time, the phase comparator 42 compares the input clock pulse CLK with the magnetic pole detection pulse P and outputs a voltage Vdet corresponding to the phase difference to the integrating circuit 46, and the integrating circuit 46 inputs the input voltage Vd.
The voltage ΔV obtained by integrating et is output. Then, drive power 48
In, the drive voltage VDD is increased / decreased by adding the input voltage ΔV from the integration circuit 46 to the reference voltage VST.
For example, in the case of high speed conveyance or heavy object conveyance (low speed), the output torque of the stepping motor 3 is insufficient for the load,
The stepping of the stepping motor 3 (rotational phase, that is, the magnetic pole detection pulse P) lags behind the clock pulse CLK. At this time, the output voltage VDET of the phase comparator 42 rises, and as a result, the drive voltage VDD rises and the conduction current increases. Therefore, the output torque of the stepping motor 3 is increased to overcome the load and the conveyance speed is increased to a predetermined set speed.

Then, the output voltage Vdet of the phase comparator 42 decreases and the output voltage ΔV of the integrating circuit 46 also decreases as the transport speed increases, but the peak voltage of the integrating circuit 46 is maintained by the peak hold circuit 47. The current supplied from the drive power source 48 to the power transistor array Tr and the phase winding L is maintained at the increased level. Therefore, even when the stepping motor 3 is decelerated thereafter to stop the transported object,
A sufficient current corresponding to the inertial force of the transported object is continuously supplied to the phase winding L, and the transported object is quickly stopped.

That is, the energization current to the phase winding L is set according to the maximum value of the load generated in the process of transporting the transported object, and the stepping motor 3 does not lose the load at the start of the transportation. The clock pulse CL is used in all situations, such as accelerating the transported object and stopping it at the end of transportation without losing inertial force.
It will move up and down in synchronization with K. The peak hold circuit 47 is reset when the distribution circuit 34 stops operating.

In this way, the stepping motor 3 uses the clock pulse CLK
, The counter 40 continues counting and counts to zero, and at the same time outputs the counting completion signal S2 to the distribution circuit 34. Therefore, since the distribution circuit 34 stops the distribution / output of the drive pulses φ1 to φ4, the stepping motor 3 also stops.

As described above, in the carrier device 1 of this embodiment,
A magnetic sensor 15 built in the stepping motor 3 detects a stepping motion of the stepping motor 3, and a phase comparator 42 detects a phase difference between the clock pulse CLK and the magnetic pole detection pulse P, which holds the peak value. Since the energizing current of the phase winding L is controlled according to the output of the hold circuit 47, the energizing current to the phase winding L becomes the maximum value of the load generated in the process of conveying the transported object. It will be set accordingly.

Therefore, according to the carrying apparatus 1 of the present embodiment, the stepping motor 3 is set to the clock pulse CLK regardless of the weight of the object to be carried or the carrying speed thereof and in all situations including the start and the end of the carrying. It is possible to move the floors in synchronism with each other, and it is possible to quickly and accurately convey the object to be conveyed to a desired position.

In addition, the forward / reverse selector switch 56
Since the rotation direction of the stepping motor 3 can be switched only by switching the distribution sequence of the drive pulses φ1 to φ4 in 34, the transfer direction can be easily switched.

Further, the control circuit 22 has a simple structure, and thus is easy to manufacture.

Although the present embodiment is configured to carry the paper in the forward direction or the reverse direction and stop at the set stop position, in addition to this, after the stepping motor 3 is stopped, the counter 40 is activated by the counting completion signal S2. The count mode may be switched from count down to count up and the distribution sequence of the drive pulses φ1 to φ4 of the distribution circuit 34 may be switched. In this case, the carriage 11 can be returned to the initial position by lowering the conveyed product at the stop position and pressing the start switch 50 again.

[Advantages of the Invention] As described in detail above, in the transport apparatus of the present invention, the phase difference between the reference signal and the stepping (rotational phase) of the stepping motor is detected, and the energizing means is energized according to the peak value. Since the amount is controlled, the energization current to each phase of the stepping motor is set according to the maximum value of the load generated in the process of conveying the transported object.

Therefore, according to the transporting apparatus of the present invention, the stepping motor is synchronized with the reference signal regardless of the weight of the transported object or its transporting speed and in all situations including the start and end of the transport. Therefore, it is possible to move the object to be conveyed to a desired position quickly and accurately.

[Brief description of drawings]

FIG. 1 (A) is a front view of the carrier device of the embodiment, FIG. 1 (B) is a plan view thereof, and FIG. 2 is a block diagram of a controller of the carrier device. 1 ... Conveying device, 3 ... Stepping motor 9 ... Timing belt, 11 ... Carriage 15 ... Magnetic sensor, 20 ... Control section 22 ... Control circuit, 24 ... Operation panel 32 ... V / F converter , 34 ...... Distribution circuit 36 ...... Drive circuit, 40 ...... Counter 42 ...... Phase comparator, 48 ...... Drive power supply 47 ...... Peak hold circuit

Claims (1)

[Scope of utility model registration request] 1. A conveying means for conveying an object to be conveyed to a predetermined position, a stepping motor for driving the conveying means, a stepping motor built in the stepping motor for detecting a stepping motion of the stepping motor and outputting a detection signal. Detecting means, reference signal creating means for creating a reference signal for determining the stepping timing of the stepping motor, and energization for energizing each phase of the stepping motor in a predetermined circulation order based on the created reference signal. Means, a phase difference detecting means for detecting a phase difference between the reference signal of the reference signal generating means and a detection signal of the step motion detecting means, and a peak value of the phase difference detected by the phase difference detecting means. A peak value detecting means; and a control means for controlling the energization amount of the energizing means based on the peak value detected by the peak value detecting means. Conveying apparatus according to claim.