JPH0466929B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for preventing the occurrence of roving fine spots in a roving frame.

Prior Art In general, in a roving machine, when the machine is stopped and then restarted, excessive tension is applied to the roving yarn between the front roller and the bobbin, causing fine spots on the roving yarn.
There was a problem in that it caused inconvenience in the post-process. This is because, as shown in Figure 1, there is a difference in inertia between the rotational transmission systems that transmit the rotation of the driving pulley 1 to the front roller 2, bobbin 3, and flyer 4, respectively. It is thought that this is because the harmony between them is momentarily disrupted and an incorrect draft is given to the spun roving. Conventionally, as a method to prevent the occurrence of fine spots on the roving yarn when restarting the machine, there has been a method of
No. 42-19900 discloses that an electromagnetic clutch 8 is provided on a short cone shaft 7 between a bottom cone drum 5 and a differential gear mechanism 6, which constitute a bobbin rotation system of a rover frame, to connect the bottom cone drum 5 to the bobbin 3. A roving fine unevenness prevention device has been proposed that can control the transmission of rotation. In this roving fine unevenness prevention device, as shown in Fig. 2, when the timer TR1, which starts counting with the machine stop command, times up, the electromagnetic clutch 8, which had been kept connected until then, is disconnected, and the bobbin rotates. As the inertia of the system decreases, the winding speed slows down and the roving becomes slack between the front roller 2 and the flyer top 4a, and the electromagnetic clutch 8 is turned on again after a certain period of time by the timer TR2 which starts counting at the same time as the timer TR1 times up. is connected, the bobbin rotation system returns to steady rotation, and when the machine is completely stopped, the 3rd
As shown in the figure, the roving R transitions from an excessively slack state indicated by a chain line to an appropriately slack state indicated by a broken line. However, since the braking load torque of the machine generally changes over time, the winding speed (shown by the solid line) and spinning speed (shown by the chain line) after the machine stop command in Figure 2 decreases with long-term use. The slope of changes. In the conventional apparatus, since the set times of the timers TR1 and TR2 are fixed values, there is a problem that the amount of slack in the roving yarn when the machine is completely stopped may not be appropriate.

Purpose This invention has been made in view of the above-mentioned problems, and its purpose is to be able to always obtain an appropriate amount of roving slack when stopped in response to changes in braking load torque over time, and to be able to regenerate. It is an object of the present invention to provide a method for preventing the occurrence of roving fine spots in a roving machine, which can completely prevent the occurrence of roving fine spots at the time of startup.

Structure of the Invention In order to achieve the above-mentioned object, the present invention provides a non-contact sensor that can continuously detect the position of the roving between the front roller and the flyer top, and adjusts the winding speed after the machine is stopped. A speckle generation prevention device is activated to reduce the speed of the roving so that it is slower than the feeding speed, and the value indicating the slack of the roving calculated by the microcomputer based on the detection signal of the sensor becomes equal to a predetermined reference value. At this point, the operation of the device for preventing the occurrence of fine spots is stopped, and after the machine has completely stopped, the amount of slack in the roving yarn is calculated, and if the value deviates from the predetermined range, it is possible to prevent the occurrence of fine spots at the next stop. The reference value for determining the timing for stopping the operation of the prevention device is modified.

Examples Examples 4 to 9 which embody this invention will be described below.
This will be explained according to the diagram. In the apparatus of this embodiment, as shown in FIG. 4, a non-contact type sensor 9 for continuously detecting the position of the roving yarn R is disposed between the front roller 2 and the flyer top 4a. This device is different from the conventional device, but the other configurations are basically the same, and the same parts are designated by the same reference numerals and the explanation thereof will be omitted. As shown in FIG. 5, the sensor 9 includes a light emitting part 10 and a light receiving part 11 which are arranged opposite to each other, and the roving R is arranged between them. The light emitting section 10 is composed of an infrared light emitting diode array, and the light emitting section 11 has a light receiving element array consisting of a large number of light receiving elements 11a arranged vertically in parallel at a pitch of about half the diameter of the roving R (about 1 mm). have. Each light receiving element 11a emits an electric signal corresponding to the intensity of the light it receives, and inputs it to a microcomputer (hereinafter abbreviated as microcomputer) M. Since the roving R blocks part of the light from the light emitting part 10, the light receiving element 11a corresponding to the position of the roving R no longer receives light, so the position of the roving R can be determined by detecting the light receiving element 11a. You can ask for it. In the device of this embodiment, the pitch of the light receiving elements 11a is approximately 1 mm, and
Since the diameter of the infrared light from each light receiving diode 10a is smaller than the diameter of the roving R, which is a shielding object, and has the property of diffusion, the infrared light is shielded by the roving R as shown in FIGS. 6a to 6c. 1 to 3 light receiving elements 11 at a time
a senses. The light receiving element 11 that sensed this shielding
Read the value of a and convert it to a position value. Three light receiving elements 11 as shown in FIG. 6a
If a senses the shielding at the same time, the center position of the central light receiving element 11a is determined to be the position of the roving R,
When the two light-receiving elements 11a detect shielding at the same time as shown in FIG. 3b, the intermediate position between them is
When only one light-receiving element 11a senses the shielding as shown in FIG. 3c, the center position of the light-receiving element 11a is determined to be the position of the roving R, respectively. The pitch of this position data is one half of the pitch of the light receiving element 11a, and in the apparatus of this embodiment, position data with a pitch of 0.5 mm can be obtained.

Next, a method for determining the slack amount of the roving yarn R using the input signal from the sensor 9 in the microcomputer M will be explained. During operation of the machine, the roving R vibrates due to factors such as vibration of the machine or rotation of the flyer top 4a, so first, position data is collected for a predetermined time T1 as shown in Fig. 7. ,
Find the maximum value MAX and minimum value MIN between them, repeat this n times, and obtain n maximum values (MAX
1 to n) and the minimum value (MIN1 to n). Then, based on the value, level data L corresponding to the amount of roving slack defined by the following equation is calculated.

L=(1/n) _o 〓 ^k=1 (MAXk×MINk) Next, the operation of the device configured as described above will be explained. The device is operated according to the flowchart of FIG. When the machine stop command causes driving pulley 1 to rotate due to inertia, timer TR1 is activated.
starts counting. When the timer TR1 times out after a predetermined set time has elapsed, the electromagnetic clutch 8, which serves as a speckling prevention device, is held in a disconnected state. As a result, the inertia of the winding system decreases, and the decrease in the winding speed becomes greater than the decrease in the spinning speed, and eventually the winding speed becomes smaller than the spinning speed, and the roving R begins to slacken. Simultaneously with the disengagement of the electromagnetic clutch 8, the microcomputer M calculates the amount of slack in the roving R based on the detection signal from the sensor 9, and compares the calculated value with a reference value α. When the slack amount of the roving reaches the reference value α, the microcomputer M issues a signal to connect the electromagnetic clutch 8. This signal causes the electromagnetic clutch 8 to be held in the connected state again, and the inertial rotation of the bottom cone drum 5 is again transmitted to the short cone shaft 7. Then, as shown in Figure 9, the winding speed becomes faster than the spinning speed again, the amount of slack in the roving yarn R, which had been too slack, becomes smaller, the inertial rotation stops, and the machine completely stops. The yarn R will be in a state with an appropriate amount of slack. After the machine has completely stopped, the amount of slack in the roving is measured again, and it is determined whether the amount of slack is within a predetermined reference range β, and it is determined whether the amount of slack in the roving R deviates from the reference range β. In this case, the reference value α, which determines the timing of issuing the connection signal to the electromagnetic clutch 8, is modified. As a result, the machine is stopped in a state where the roving yarn R has an appropriate amount of slack even when the machine is stopped next time, and it is possible to reliably prevent the occurrence of fine spots in the roving yarn when the machine is restarted. Note that the value of the reference range β is set to a range narrower than the range of slack amount in which fine spots of the roving do not occur when the machine is restarted.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and for example, instead of providing the electromagnetic clutch 8 on the short cone shaft 7 as a speckle generation prevention device that reduces the winding speed to be slower than the feeding speed. As shown in FIG. 10, a solenoid 14 is attached to a belt shifter 13 mounted on a long rack 12, and one end of a lever 16, on which a pivot shaft 15 is supported on the belt shifter 13, is connected to a plunger 17 of the solenoid 14. A device in which the other end is connected to a fork 19 that clamps the belt 18 may be used. In this device, the solenoid 14 is energized by the time-up of the timer TR1, and the belt 18 is moved in the direction of arrow P in FIG. The amount of slack in R increases. Then, the excitation of the solenoid 14 is canceled by the microcomputer M's stop signal for the prevention device, and the belt 18 returns to its normal position, and the winding speed increases in the same way as when the electromagnetic clutch 8 is connected. The slack amount of R becomes small, and when the machine is completely stopped, the slack amount of the roving R becomes a predetermined appropriate value.

Effects As detailed above, according to the present invention, the operating time of the speckle generation prevention device is automatically adjusted, so that the roving is always adjusted to the appropriate level when stopped in response to changes in braking load torque over time. It is possible to obtain the amount of slack, and this has an excellent effect of reliably preventing the occurrence of roving fine spots when restarting the machine.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view showing the drive mechanism of a roving frame equipped with an electromagnetic clutch as a speckling prevention device, and Fig. 2 is a line showing the relationship between spinning speed and winding speed in a conventional speckling prevention device. 3 is a schematic side view showing the condition of the roving between the front roller and the flyer top, FIG. 4 is a side view showing the sensor mounting position of the device for embodying this invention, and FIG. Front view showing the relationship between the thread and the sensor, Figure 6a
~c is a schematic diagram showing the state of shielding of light from the light emitting part by the roving, FIG. 7 is a diagram showing the change in the position of the roving,
Figure 8 is a flowchart for explaining the action.
FIG. 9 is a diagram showing the relationship between winding speed and spinning speed, and FIG. 10 is a perspective view of a main part showing a modification of the device for preventing occurrence of fine spots. Front roller...2, bobbin...3, flyer top...4a, electromagnetic clutch...8, sensor...9, belt shifter...13, microcomputer...M, roving...R.

Claims (1)

[Claims] 1 A non-contact sensor that can continuously detect the position of the roving between the front roller and flyer top is installed to reduce the winding speed to be slower than the feed speed after the machine is commanded to stop. activating the prevention device, and stopping the operation of the speckle generation prevention device when a value indicating the slack of the roving calculated by a microcomputer based on the detection signal of the sensor becomes equal to a predetermined reference value; After the machine has completely stopped, the amount of slack in the roving is calculated, and if the value deviates from a predetermined range, the reference value that determines the timing for stopping the operation of the speckle generation prevention device at the next stop is corrected. A method for preventing the occurrence of roving fine spots in a roving frame.