JP3070273B2 - Thread breakage detection device in ring spinning machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a yarn breakage in a ring spinning machine and a ring twisting machine (hereinafter referred to as a ring spinning machine) in which spindles of respective weights are independently driven by motors provided for the respective weights. Things.

[0002]

2. Description of the Related Art When a yarn break occurs during spinning, it is desirable to detect the yarn break reliably and early in order to quickly repair the yarn break. Therefore, the spinning machine is provided with a yarn breakage detecting device. On the other hand, in recent years, in order to increase the number of spindles of the spinning frame or increase the spindle rotation speed, instead of driving all the spindles of the spinning frame with one motor, a spindle driving motor is provided for each spindle. Provided devices have been proposed. Japanese Patent Application Laid-Open No. 54-88330 and Japanese Patent Application Laid-Open No. 1-2298 disclose a method of detecting a thread break utilizing the characteristics of a device for driving a spindle by a separate motor for each weight.
No. 30 discloses this.

The method disclosed in Japanese Patent Application Laid-Open No. 54-88330 detects the current consumption of a turbine (spindle) that drives the rotor of an open-end spinning machine, and determines the current consumption to be a predetermined value corresponding to a yarn breakage. It is determined that the thread break has occurred when the value has decreased to the set value. A first method disclosed in Japanese Patent Application Laid-Open No. 1-229830 is to detect a current value used by a motor of each spindle in a ring spinning machine or the like, to extract a current change associated with each elevating and lowering of a ring rail. When the current change becomes zero, it is determined that the thread is broken. The second method is to measure the current value used by the motor of each weight, and compare the measured value with a value set in advance in accordance with an increase in the winding amount with the elapsed time from the start of winding. When the difference from the set value is equal to or more than a predetermined amount, it is determined that the thread is broken.

[0004]

Problems to be Solved by the Invention
No. 0 discloses a turbine of an open-end spinning machine in which winding of the yarn is performed by a drive system different from that of the turbine, and the load applied to the turbine is equal to the load of the yarn if the spinning conditions are the same. The current consumption of the turbine is constant from the start to the end of the winding. Therefore, if a predetermined set value corresponding to the yarn breakage is provided for each spinning condition,
Thread breakage can be detected regardless of the time elapsed from the start of winding.

However, in a ring spinning machine or the like, since the yarn is wound on a bobbin on a spindle, the load applied to the spindle driving motor changes with the lapse of time from the start of winding. In addition, the ring rail repeats ascending and descending movements at the time of winding, and the balloon shape of the yarn from the snell wire to the traveler differs depending on the position of the ring rail, thereby changing the load. Therefore, unlike an open-end spinning frame, a ring spinning frame or the like requires a large number of set values corresponding to the lapse of time from the start of winding, even under the same spinning conditions. In addition, since the winding state is different for each weight, it is necessary to store those set values for each weight and to compare the current consumption with the lapse of time. The second method disclosed in Japanese Patent Laid-Open No. 1-229830 corresponds to this. However, this method requires a storage device for storing a large number of data for comparison.

In the first method disclosed in Japanese Patent Laid-Open Publication No. 1-229830, when a change in current corresponding to a change in the tension of the yarn becomes zero, it is determined that the yarn is broken. There is a problem that it takes time from detection to detection.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a simple and simple method for a ring spinning machine or the like in which spindles of each weight are independently driven by motors provided for each weight. An object of the present invention is to provide a yarn breakage detecting device in a ring spinning machine or the like which can reliably and quickly detect a yarn breakage with a configuration.

[0008]

According to the present invention, there is provided a ring spinning machine or the like in which spindles of respective weights are independently driven by motors provided for the respective weights. A current sensor that is provided between the power supply that supplies the motor and each motor, and measures a current supplied to each motor, and obtains a current change rate by inputting an output signal from the current sensor, and calculates the current change rate. A determination means is provided for comparing with a predetermined set value and determining that the yarn breakage occurs when the current change rate exceeds the set value.

[0009]

The spindle of each weight is driven by a single spindle drive motor. The magnitude of the current supplied to the motor of each weight is measured by a current sensor provided for each weight. Electric power is supplied to each motor in accordance with the load of each motor, and a current corresponding to the electric power flows through each motor.
In a state where the yarn is normally spun, the load by the yarn balloon is applied to each motor. However, when the yarn breaks, the load by the yarn balloon is removed, and the current supplied to the motor decreases rapidly. The judging means receives the output signal from the current sensor to obtain a current change rate, and compares the current change rate with a predetermined set value. Then, when the current change rate exceeds the set value, it is determined that the yarn is broken.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. Each spindle 1 of the spinning machine is provided with a spindle driving motor 2. A three-phase induction motor is used as the spindle drive motor 2, and the spindle drive motor 2 is connected to a power supply line 4 connected to a power supply 3 via a power supply line 5. A large number of spindle drive motors 2 (only one is shown) are connected to the power supply line 4 in parallel.

A current sensor 6 for measuring a current supplied to each spindle driving motor 2 is provided on an arbitrary one of the three power supply lines 5 of each weight. The current sensor 6 is preferably a current transformer type sensor, a Hall element sensor or the like, but may be a current shunt type sensor. The current sensor 6 is connected to a judgment circuit 7 as judgment means.

A determination circuit 7 determines a rate of change of the current supplied to the spindle driving motor 2 based on an output signal from the current sensor 6, and compares the output of the differentiation circuit 8 with a predetermined set value. And a comparison circuit 9.
When the output signal of the current sensor 6 is a current, for example, when a current transformer type sensor is used as the current sensor 6, the determination circuit 7 converts the output signal of the current sensor 6 into a voltage, and then inputs the voltage to the differentiating circuit 8. . When the output signal of the current sensor 6 is a voltage, for example, when a Hall element sensor or a shunt type sensor is used as the current sensor 6, the output signal of the current sensor 6 is directly input to the differentiating circuit 8. .
The determination circuit 7 determines that a thread break has occurred when the output of the differentiating circuit 8 exceeds a predetermined set value, and outputs a thread break signal. The power supply line 5 is provided with a normally closed contact of a relay (both not shown), and the relay is excited based on the thread break signal to open the normally closed contact. The power supply is stopped.

Next, the operation of the device configured as described above will be described. Each motor 2 for the spindle drive motor 2
The power corresponding to the load applied to the power supply is supplied. The electric power consumed by the spindle driving motor 2 during spinning is the sum of the electric power for driving the spindle 1, the electric power for rotating the tubing (not shown), and the electric power for the yarn balloon.
Is always constant, and increases as the winding of the yarn progresses, that is, as the yarn becomes larger.
Also, the power varies depending on the shape of the balloon, and the balloon fluctuates during spinning due to the chase motion, so that the power also varies correspondingly.

The value of the current flowing through the power supply line 5 is measured by the current sensor 6, and the measurement signal is output to the determination circuit 7. The signal output to the determination circuit 7 is input to the differentiating circuit 8 as a voltage signal, and the output signal of the differentiating circuit 8 corresponding to the current change rate is output to the comparing circuit 9. Then, the signal is compared with a predetermined set value by the comparing circuit 9, and when the output signal of the differentiating circuit 8 exceeds the set value, it is determined that a thread break has occurred, and a thread break signal is output.

[0015] When a yarn break occurs, the electric power is lost when the balloon of the yarn is lost. Therefore, the current supplied to the spindle drive motor 2 decreases rapidly. The change in the current value at this time varies depending on the spinning conditions, but is 10 to 20%. This current change rate is much larger than the power change rate and the current change rate accompanying the power change. Since the set value of the comparison circuit 9 is set to a value corresponding to the current change rate at the time of the rapid current change, the output signal from the differentiating circuit 8 fluctuates according to the current change rate fluctuating during normal spinning. Even if it does not exceed the set value. When a yarn break occurs, the output signal from the differentiating circuit 8 reliably exceeds the set value, and the yarn break is reliably detected.

Since the electric power fluctuates at the time of spinning due to the chase movement, if the absolute value of the current change is obtained and the change amount (decrease amount) is used to judge the yarn breakage, an erroneous judgment is caused.
However, in the present invention, since the yarn breakage determination is performed based on the current change rate, the current change due to the chase movement can be ignored. or,
Since the current change rate is compared with the set value, there is no need to store a steady-state current value that differs greatly depending on spinning conditions for comparison.

Further, when a yarn break occurs, the current immediately drops sharply, and the current change rate surely becomes larger than a set value, the determination circuit 7 determines that the yarn is broken, and the determination circuit 7 outputs a yarn break signal. Then, the power supply to the spindle driving motor 2 of the weight is immediately stopped by the signal, and the spindle 1 stops. Therefore, it is possible to prevent the adjacent weight from being broken due to the continued rotation of the spindle 1 after the occurrence of the yarn breakage. In addition, the generation of fluff due to the yarn breakage bobbin being rotated for a long time is reliably prevented.

The present invention is not limited to the above embodiment. For example, a current sensor may be provided on each feed line 5 of each weight. Also, the power supply does not necessarily have to be a three-phase alternating current.

[0019]

As described above in detail, according to the present invention, the yarn breakage can be achieved with a simple structure by utilizing the characteristics of the system in which the spindle of each weight is independently driven by the motor provided for each weight. The detection can be performed reliably and quickly, and the breakage of the thread of the adjacent weight due to the occurrence of the thread break can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a change in current value before and after yarn breakage.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... spindle, 2 ... spindle drive motor, 3 ... power supply, 4 ... power supply line, 5 ... power supply line, 6 ... current sensor, 7 ... judgment circuit as judgment means, 8 ... differentiation circuit, 9 ... comparison circuit.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-229830 (JP, A) JP-A-54-88330 (JP, A) JP-A-1-229826 (JP, A) JP-A-51- 32841 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01H 13/16 D01H 1/244

Claims (1)

(57) [Claims] In a ring spinning machine or the like in which spindles of each weight are independently driven by motors provided for the respective weights, the spindle is provided between a power supply for supplying electric power to the respective motors and the respective motors. A current sensor that measures the current supplied to the motor; and an output signal from the current sensor is input to obtain a current change rate, and the current change rate is compared with a predetermined set value. A yarn breakage detecting device in a ring spinning machine or the like, provided with a judging means for judging a yarn breakage when exceeding.