JPH0122192B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the speed control method of a spindle-driven winder having a touch roller for applying surface pressure.

Generally, in a spindle-driven winding machine, the bobbin attached to the spindle is brought into contact with a rotatable touch roller, then the induction motor for driving the spindle is started by an inverter, and when the spindle reaches a predetermined operating speed, the yarn is wound. is being carried out.
When the bobbin becomes fully wound by winding the yarn, the touch roller is separated from the bobbin, the spindle is braked and stopped, and the fully wound bobbin is replaced with an empty bobbin. The touch roller separated from the thread winding bobbin continues to rotate at approximately the winding speed even during the bobbin replacement operation. Therefore, when the tachi roller is brought into contact with the empty bobbin that has been replaced, the induction motor is rotated by the tachi roller together with the spindle. At this time, the change in surface speed of the touch roller and spindle is shown in the speed curve a of the touch roller as shown in Figure 2.
decelerates as time passes after contact with the empty bobbin, the speed curve b of the spindle with the empty bobbin increases and becomes the same at a certain speed, and if the induction motor is not started as it is, it will continue to decelerate at speed curve c. Stop. However, normally the tatsuchi roller and empty bobbin are brought into contact and the induction motor is started after a random period of time has elapsed and the induction motor is free-running.Therefore, in the commonly used operating method, there is a certain time constant from the lowest speed to the predetermined operating speed. If a method of accelerating the motor is used, regenerative energy will be fed back to the inverter when the motor is started, and the inverter will need to take measures against regenerative energy, making the inverter itself very large. In addition, as shown by the No. 1 curve in Figure 2, the induction motor temporarily generates braking torque, and the motor that was accelerated to a certain rotational speed by the touch roller (after point Y in Figure 2) is greatly decelerated and restarted. Since the speed is increased to reach a predetermined operating speed, there are problems such as unnecessary operation and a long start-up time, which is not very desirable in terms of the life of the drive system. Furthermore, if a method of direct starting at a predetermined operating speed is adopted, the starting current is large, resulting in a large capacity inverter. Furthermore, if the inverter is equipped with a current limiting circuit, it is possible to suppress the current at startup, but since the synchronous speed of the induction motor is far out of sync (slip is large), the output torque is suppressed and the start-up time is extremely long. There was a problem.

The present invention was obtained as a result of studies aimed at solving the above-mentioned problems when starting a winding machine.

That is, the present invention uses a winding machine configured to drive a bobbin-mounted spindle using an induction motor with a current-limited inverter interposed, and to bring a rotatable touch roller into contact with the bobbin to apply surface pressure. When a bobbin attached to a stopped spindle is brought into contact with a stopped spindle and started, the induction motor is set to a predetermined operating speed and started, and the no-load current of the induction motor is increased by the starting current of the induction motor. A comparator circuit set to a slightly larger current value is operated to decelerate the set speed by a certain time constant, and when this set speed decelerates to around the rotational speed of the induction motor and becomes less than the current value, the comparator circuit is reversed and the set speed is reduced to the set speed. The present invention provides a speed control method for a winder in which the winder is accelerated at a certain time constant to a predetermined operating speed.

An embodiment of a speed control circuit diagram for a winder according to the present invention is shown in FIG. 1 and will be explained based on the drawing.

1 is a speed setting device for setting the operating speed; 2
is an acceleration/deceleration device that sends a predetermined acceleration or deceleration signal to the inverter 3 based on the signal from the speed setting device 1. Inverter 3 controls the speed of induction motor 4 based on the signal from accelerator/decelerator 2 . The induction motor 4 is connected to a spindle 11 on which a bobbin B is mounted. 5 is a relay, and 6 is a memory. 7
is an AND circuit, and 8 is an inverse circuit.
9 is a comparator, and 10 is a current setter. The circuit formed by these is such that when the detected current value of the induction motor 4 is larger than the current value of the current setting device 10, the output of the comparator 9 becomes 1, and this signal and the start signal are passed through the AND circuit 7, and the memory 6 is set and relayed. 5 operates, the contact opens, and the output frequency of the inverter 3 is decelerated toward 0 speed. When the detected current value is smaller than the set current value, the output of the comparator 9 becomes 0, the memory 6 is reset through the inverter circuit 8, and the relay 5 operates to close the contact and return to the operating speed set by the speed setting device 1. It's starting to accelerate towards that direction. Reference numeral 12 denotes a touch roller, which is rotatably attached to a machine stand (not shown).

The speed control operation by the speed control circuit having the above configuration will be explained with reference to speed change diagrams shown in FIGS. 1 and 2.

First, a predetermined operating speed is set in the speed setter 1, an acceleration time constant and a deceleration time constant are set in the accelerator/decelerator 2, and a current value slightly larger than the no-load current of the induction motor 4 is set in the current setter 10, respectively.

Next, the touch roller 12 is brought into contact with the bobbin B mounted on the spindle 11. In this state, a starting switch (not shown) is turned on, the yarn is accelerated with a predetermined acceleration time constant, and the operating speed is increased to a predetermined speed, and the yarn is wound onto a bobbin while being traversed. Bobbin B
When the bobbin is fully wound, the full bobbin of the touch roller 12 and the separation spindle 11 is replaced with an empty bobbin. After replacing the bobbin, the empty bobbin B mounted on the spindle 11 is brought into contact with the touch roller 12 which is rotating at approximately the operating speed. Due to this contact action, the empty bobbin B rotates while accelerating at a predetermined speed, and the touch roller 1
2 rotates while decelerating. When a predetermined time has elapsed since the empty bobbin B was brought into contact with the empty bobbin B, a starting switch (not shown) is turned on and the induction motor 4 connected to the spindle 11 is set at a frequency corresponding to the operating speed set on the speed setting device 1. Start by applying voltage directly. When the induction motor 4 is started, a start signal is sent to the AND circuit 7. On the other hand, the current of the induction motor 4 is detected as a DC current from the inverter 3 and sent to the comparator 9, where it is compared with the current value set in the current setting device 10. Since the induction motor 4 is started by directly applying the frequency and voltage corresponding to the set operating speed, the current value is large and the output of the comparator 9 is 1.
As a result, the memory 6 is set through the AND circuit 7, the relay 5 is operated and the contact is opened, and the output frequency of the inverter 3 is decreased by the deceleration time constant set in the accelerator/decelerator 2 toward 0 speed. When the output frequency of the inverter 3 approaches the rotational speed of the motor 4 and becomes below the set current value of the current setting device 10, the output of the comparator 9 becomes 0, the memory 6 is reset through the inverse circuit 8, and the relay 5 operates to close the contact. is closed, and the output frequency of the inverter 3 drives the induction motor 4 to accelerate toward the operating speed set by the speed setting device 1 with the acceleration time constant set in the accelerator/deceleration device 2 (point X in Figure 2). . It accelerates at a predetermined time constant (No. 2 curve in Figure 2) and when the operating speed is reached, the yarn material is wound.

Speed control conditions of the example Operating speed (frequency of induction motor): 290 Hz (touch roller surface speed at this time 6000 m/min) Acceleration time constant: 7.5 Hz/sec Deceleration time constant: 50 Hz/sec The rise curve under the above conditions is the second This is as shown in Figure No. 2, and as you can see, since the rotation is controlled without generating braking torque, the ramp-up time from startup to reaching operating speed is shortened. Furthermore, by starting the induction motor as described above, even if the frequency and voltage corresponding to the operating speed set in the speed setting device 1 are directly applied to start the motor, the starting current will not increase due to the current limiting circuit of the inverter. Moreover, since the regenerative energy is not fed back to the inverter, the speed of the induction motor can be controlled using an inverter with a normal capacity and no regenerative energy countermeasures.

The initial starting method when the touch roller 12 is not rotating has been briefly described to avoid duplication of explanation, but it is the same as the starting method when the touch roller 12 is rotating.

In the present invention, when a bobbin attached to a stopped spindle is brought into contact with a Tatsuchi roller rotating at a predetermined speed and started, the induction motor is set to a predetermined operating speed and started, and the starting current of the induction motor is used to start the motor. A comparison circuit set to a current value slightly larger than the no-load current of the induction motor is operated to decelerate the set speed with a certain time constant, and when the set speed decelerates to around the rotational speed of the induction motor and becomes below the current value, a comparison is made. By inverting the circuit and controlling the speed so that the set speed is accelerated with a certain time constant and raised to a predetermined operating speed, the following effects can be achieved.

Even if the Γ conductive motor is started by directly applying the frequency and voltage corresponding to the set operating speed, the inverter's current limiting circuit prevents the starting current from increasing, eliminating the need for a large capacity motor, and allowing regenerative energy to be transferred to the inverter. Since the energy is not returned to the inverter, there is no need for regenerative energy measures in the inverter, and the inverter does not become large.

ΓIn order to control the rotation so that no braking torque is generated even if the induction motor is brought into contact with the tatsuchi roller rotating at a predetermined speed and started in a free running state, the time from the start until the predetermined operating speed is reached is determined. Can be shortened.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing one embodiment of a speed control circuit for a winder according to the present invention. FIG. 2 is a schematic diagram showing speed changes. 1: Speed setting device, 2: Accelerator/decelerator, 3: Inverter, 4: Induction motor, 5: Relay, 6: Memory,
7: AND circuit, 8: Inverse circuit, 9: Comparator, 10: Current setting device, 11: Spindle, 1
2: Tatsuchirolla.

Claims (1)

[Claims] 1 The bobbin-mounted spindle is driven by an induction motor with a current-limiting inverter, and the rotatable tatsuchi roller is rotated at a predetermined speed using a winding machine configured to bring the rotatable tatsuchi roller into contact with the bobbin to apply surface pressure. When starting the bobbin by contacting the bobbin attached to the stopped spindle, the induction motor is set to a predetermined operating speed and started, and the starting current of the induction motor generates a current that is slightly larger than the no-load current of the induction motor. The comparison circuit set to the value is operated to reduce the set speed by a certain time constant, and when this set speed decelerates to around the rotational speed of the induction motor and becomes less than the previous current value, the comparison circuit is reversed and the previously set speed is reduced to the same value. A speed control method for a winder, characterized in that the speed is increased to a predetermined operating speed by accelerating with a time constant.