Claims:I/We claim:

1. An abnormality diagnosing device (60) that diagnoses an abnormality in a yarn cutting device (40), the yarn cutting device (40) including a cutting blade (42) operated by a solenoid (41) to cut a yarn (Y) by positioning the yarn (Y) between a receiving portion (43b) and the cutting blade (42), comprising:
a diagnosing section (61) that diagnoses at least one between an abnormality in an operation of the cutting blade (42) and a shape of the cutting blade (42) based on a temporal change in an electric current flowing in the solenoid (41).

2. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in Claim 1, wherein the diagnosing section (61) diagnoses an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade (42) based on one between
a peak electric current value at a peak point at which the electric current flowing in the solenoid (41) reaches a maximum value after an operation command to operate the cutting blade (42) is output, and
presence or absence of the peak point.

3. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in Claim 2, wherein the peak point corresponds to an electric current value when the electric current reaches an initial maximum value.

4. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in Claim 2 or 3, wherein the peak point corresponds to an electric current value when the electric current reaches a subsequent maximum value after the initial maximum value.

5. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in one of Claims 1 to 4, wherein the diagnosing section (61) diagnoses an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade (42) based on any of
a valley electric current value at a valley point when the electric current flowing in the solenoid (41) reaches a minimum value after the operation command to operate the cutting blade (42) is output,
presence or absence of the valley point, and
a valley time required to reach the valley point.

6. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in Claim 5, wherein the valley point corresponds to an electric current value when the electric current reaches the initial maximum value, decreases, and then reaches an initial minimum value.

7. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in Claim 5 or 6, wherein the valley point corresponds to the electric current value when the electric current reaches the initial maximum value, decreases, reaches the initial minimum value and then reaches a subsequent minimum value after the initial minimum value.

8. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in one of Claims 1 to 7, wherein the diagnosing section (61) diagnoses an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade (42) based on one between
an electric current difference between a peak electric current value at a peak point at which an electric current value of the electric current flowing in the solenoid (41) reaches a maximum value after an operation command to operate the cutting blade (42) is output and a valley electric current value at a valley point at which the electric current value of the electric current reaches a minimum value immediately after the peak point, and
a time difference between a peak time, which is the time required to reach the peak point, and a valley time, which is the time required to reach the valley point.

9. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in Claim 8, wherein the peak point corresponds to an electric current value when the electric current reaches an initial maximum value, and the valley point corresponds to an electric current value when the electric current decreases immediately after the peak point and reaches a minimum value.

10. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in Claim 8 or 9, wherein
the peak point corresponds to an electric current value when the electric current reaches a subsequent maximum value after the electric current reached an initial maximum value, and
the valley point corresponds to an electric current value when the electric current decreases immediately after the peak point is reached, and then reaches the minimum value.

11. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in one of Claims 1 to 10, wherein the diagnosing section (61) diagnoses an abnormality in the operation of the cutting blade (42) based on one standard deviation among
a peak electric current value at a peak point at which the electric current value of the electric current flowing in the solenoid (41) reaches a maximum value immediately after an operation command to operate the cutting blade (42) is output,
a valley electric current value at a valley point at which the electric current value of the electric current decreases and reaches a minimum value after the peak point,
an electric current difference between the peak electric current value and the valley electric current value,
a valley time that is the time required to reach the valley point, and
a time difference between a peak time, which is the time required to reach the peak point, and the valley time.

12. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in any one of Claims 1 to 11, wherein the diagnosing section (61) diagnoses an abnormality in the operation of the cutting blade (42) based on comparison between at least one present value and a reference value of the one present value at the time of manufacturing, the one present value being selected from among
a peak electric current value at a peak point at which the electric current value of the electric current flowing in the solenoid (41) reaches a maximum value immediately after an operation command to operate the cutting blade (42) is output,
a valley electric current value at a valley point at which the electric current value of the electric current decreases and reaches a minimum value after the peak point,
an electric current difference between the peak electric current value and the valley electric current value,
a valley time that is the time required to reach the valley point, and
a time difference between a peak time, which is the time required to reach the peak point, and the valley time.

13. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in any one of Claims 1 to 12, wherein the diagnosing section (61) diagnoses an abnormality in the shape of the cutting blade (42) based on one among
a valley electric current value at a valley point at which the electric current value of the electric current flowing in the solenoid (41) reaches a minimum value after an operation command to operate the cutting blade (42) is output,
an electric current difference between a peak electric current value at a peak point at which the electric current value of the electric current reaches a maximum value immediately before the valley point and the valley electric current value,
a valley time that is the time required to reach the valley point, and
a time difference between a peak time, which is the time required to reach the peak point, and the valley time.

14. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in one of Claims 1 to 13, wherein
the yarn cutting device (40) is included in a yarn monitoring device (1) that includes a detecting section (21, 22, 23, 24) that monitors a state of the yarn (Y) that is running through a detection space (11), and
the yarn monitoring device (1) outputs an operation command to operate the cutting blade (42) based on a result of the monitoring.

15. The abnormality diagnosing device (60) that diagnoses an abnormality in the yarn cutting device (40) as claimed in one of Claims 1 to 14, comprising:
a shunt resistor that is connected to the solenoid (41);
an operational amplifier that is connected to both ends of the shunt resistor to amplify an input electric voltage; and
a reading device (50) that reads an electric voltage value amplified by the operational amplifier, wherein
the diagnosing section (61) diagnoses a temporal change in the electric current flowing in the solenoid (41) based on the electric voltage value read by the reading device (50).

16. An abnormality diagnosing method used by a yarn cutting device (40) in which a cutting blade (42) is operated by a solenoid (41) and a yarn (Y) is cut by positioning the yarn (Y) between a receiving portion and the cutting blade (42), wherein
an abnormality in at least one between an operation of the cutting blade (42) and a shape of the cutting blade (42) is diagnosed based on a temporal change in an electric current flowing in the solenoid (41).

, Description:BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device and method for diagnosing abnormality in a yarn cutting device.

2. Description of the Related Art
A yarn cutting device in which a yarn is cut by operating a cutting blade with a solenoid is provided in a yarn monitoring device of a yarn winding machine. Techniques for detecting, judging, or diagnosing an abnormality in the solenoid are known in the art. For example, in the solenoid control device and the diagnosing method disclosed in the Japanese Patent Application Laid-open No. 2018-052226, when the detected value of an electric current flowing in the solenoid falls within an abnormal range, the solenoid is judged to be abnormal.
In the yarn monitoring device disclosed in the Japanese Patent Application Laid-open No. 2016-124629, presence or absence of disconnection in internal wiring is determined based on an electric signal input to a control module when an impact is applied to the internal wiring.

Problem to be solved by the Invention
In the conventional diagnosing methods explained above, it is difficult to diagnose an abnormality in an operation or a shape of a cutting blade of a yarn cutting device. For example, a method of determining an abnormality in the operation or the shape of the cutting blade by monitoring the electric voltage in a solenoid driving capacitor can be considered. However, even with such a method, it is difficult to accurately diagnose an abnormality in the operation or the shape of the cutting blade.

SUMMARY OF THE INVENTION
It is an object of the present invention to provide a device and method for diagnosing abnormality in a yarn cutting device that allows accurate diagnosis of at least one between an abnormality in an operation of a cutting blade and a shape of the cutting blade.
According to one aspect of the present invention, an abnormality diagnosing device diagnoses an abnormality in a yarn cutting device including a cutting blade operated by a solenoid to cut a yarn by positioning the yarn between a receiving portion and the cutting blade. The abnormality diagnosing device includes a diagnosing section that diagnoses at least one between an abnormality in an operation the cutting blade and a shape of the cutting blade based on a temporal change in an electric current flowing in the solenoid.
According to another aspect of the present invention, an abnormality diagnosing method is implemented on a yarn cutting device in which a cutting blade is operated by a solenoid and a yarn is cut by positioning the yarn between a receiving portion and the cutting blade. In the above abnormality diagnosing method, an abnormality in at least one between an operation of the cutting blade and a shape of the cutting blade is diagnosed based on a temporal change in an electric current flowing in the solenoid.
The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a yarn winding machine to which a yarn cutting device according to an embodiment of the present invention is applied.
FIG. 2 is a schematic view of a configuration of the yarn cutting device shown in FIG. 1.
FIG. 3 is a graph showing a typical example of a temporal change in an electric current flowing in a solenoid.
FIG. 4 is a table showing items that can be diagnosed by an abnormality diagnosing device in shown in FIG. 2 and diagnostic criteria thereof.
FIG. 5 is another table showing items that can be diagnosed by the abnormality diagnosing device in FIG. 2 and diagnostic criteria thereof.
FIG. 6 is a graph showing an example of an abnormality in the temporal change in the electric current flowing in the solenoid.

DETAILED DESCRIPTION
A yarn monitoring device 1 according to an embodiment of the present invention will be explained below with reference to the drawings. Identical elements are indicated by the same reference symbols in the drawings and redundant explanation thereof is omitted. The dimensional proportions in the drawings do not necessarily correspond to those explained in the explanation. The yarn monitoring device 1 shown in FIGS. 1 and 2 detects change in yarn thickness and foreign substances such as presence of colored yarn in a yarn Y. The yarn monitoring device 1 is mounted on, for example, an automatic winder 200 (yarn winding machine) as shown in FIG. 1. The automatic winder 200 includes a plurality of winder units (yarn processing units) 201 arranged side by side. Each winder unit 201 winds the yarn Y onto a not-shown winding bobbin. The yarn monitoring device 1 is mounted on each winder unit 201 to detect the state of the running yarn Y.
As shown in FIG. 2, the yarn monitoring device 1 includes a casing 10, a holder 15, a light projection section 21, a first reflected light receiving section 22, a second reflected light receiving section 23, a transmitted light receiving section 24, wirings 31a to 31d, a yarn cutting device 40, and a control module (control section) 50.
The casing 10 is a resin housing. The holder 15, the yarn cutting device 40, and the control module 50 are accommodated in the casing 10. The light projection section 21, the first reflected light receiving section 22, the second reflected light receiving section 23, and the transmitted light receiving section 24 that constitute a detecting section of the yarn monitoring device 1 are accommodated in the holder 15. The detecting section is a so-called optical detection unit. The wirings 31a to 31d are accommodated in the casing 10 and the holder 15. The wirings 31a to 31d are cables and / or printed wirings formed on a circuit board. The control module 50 is electrically connected to a not-shown unit controller provided for each winder unit 201 and a not-shown power source that supplies power to the control module 50.
A yarn passage 11 that functions as a detection space is formed on the holder 15 along a running direction of the yarn Y. The yarn passage 11 includes a portion that is used as a yarn path through which the yarn Y runs. The yarn passage 11 is open toward a front side of the yarn monitoring device 1.
The light projection section 21 projects light onto the yarn passage 11. The light projection section 21 is, for example, a light-emitting diode (LED), and projects light in one direction. An electric signal of a suitable voltage output from the control module 50 is input to the light projection section 21 via the wiring 31a. The light projection section 21 projects light based on the voltage of the input signal. The light projected from the light projection section 21 falls on and reflected by the yarn Y. The first reflected light receiving section 22 receives the light reflected from the yarn Y. The first reflected light receiving section 22 receives the light falling on a light receiving surface thereof. The first reflected light receiving section 22 is a photo diode. The first reflected light receiving section 22 outputs to the control module 50, via the wiring 31b, an electric signal according to the amount of the received light. The second reflected light receiving section 23 receives the light projected from the light projection section 21 that is reflected by the yarn Y. The second reflected light receiving section 23 receives light falling on a light receiving surface thereof. The second reflected light receiving section 23 is a photo diode. The second reflected light receiving section 23 outputs to the control module 50, via the wiring 31c, an electric signal according to the amount of the received light. The transmitted light receiving section 24 receives the light, projected from the light projection section 21, passing through the yarn Y. The transmitted light receiving section 24 is a photo diode. The transmitted light receiving section 24 outputs to the control module 50, via the wiring 31d, an electric signal according to the amount of the received light.
The yarn cutting device 40 includes a solenoid 41, a cutting blade 42, and an anvil 43. The solenoid 41 is an actuator that converts electrical energy into mechanical energy. The solenoid 41 includes a plunger 44 that is capable of moving linearly in a predetermined direction and a coil 45 that surrounds the plunger 44. The plunger 44 can also be referred to as a shaft. The cutting blade 42 is fixed to a tip end of the plunger 44 and is moved linearly along the predetermined direction by the driving force applied by the solenoid 41. The yarn cutting device 40 operates the cutting blade 42 by supplying an electric current to the solenoid 41. The anvil 43 is formed in an angular U shape and a pair of side walls thereof is arranged facing each other across the yarn passage 11. The solenoid 41 is fixed to a first side wall 43a of the anvil 43. When the plunger 44 moves toward the yarn Y, the cutting blade 42 collides with a second side wall (receiving portion) 43b of the anvil 43. With such an operation, the yarn Y is cut.
The yarn cutting device 40 is accommodated in the casing 10 such that the direction of movement of the cutting blade 42 is orthogonal to the running direction of the yarn Y. The yarn cutting device 40 is fixed to the casing 10 by fixing means such as screws. The cutting blade 42 traverses the yarn passage 11 with the driving force applied from the solenoid 41 and collides with the second side wall 43b of the anvil 43 accommodated in the casing 10. The yarn Y is cut when sandwiched between the cutting blade 42 and the anvil 43. The shape of the anvil 43 is not limited to U-shape. Moreover, instead of providing the anvil 43 as an independent member from the casing 10, the yarn cutting device 40 can be directly mounted on the casing 10 and the surface that forms the yarn passage 11 can be used as a receiving portion of the cutting blade 42.
The control module 50 is constituted by CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an analog front-end section, and the like. The analog front-end section includes a filter unit, a signal amplification unit, an A/D conversion unit, and the like. The control module 50 controls the operation of various parts of the yarn cutting device 40.
The yarn monitoring device 1 monitors the state of the yarn Y that runs through the yarn passage 11 during the winding operation of the yarn Y. Specifically, the control module 50 judges the state of the yarn Y based on the electric signal output by the light receiving sections 22, 23, and 24. Upon judging that the yarn Y has uneven thickness or contains foreign matter, the control module 50 outputs an operation command to the yarn cutting device 40 so as to operate the cutting blade 42 to cut the yarn Y.
The yarn monitoring device 1 includes an abnormality diagnosing device 60 that detects (diagnoses) an abnormality in at least one between an operation of the cutting blade 42 and a shape of the cutting blade 42 by monitoring the electric current flowing in the solenoid 41. The abnormality diagnosing device 60 is, for example, mounted on each winder unit 201 and is provided for one yarn cutting device 40. In the yarn cutting device 40, even when the electric current flows in the coil 45 of the solenoid 41 and the capacitor is discharged, an abnormality can occur in a sliding part of the solenoid 41, or in the components that constitute the plunger 44 or the cutting blade 42. The abnormality diagnosing device 60 is capable of diagnosing an abnormality in various parts of such yarn cutting device 40. Moreover, the abnormality diagnosing device 60 can also predict failure in various parts of the yarn cutting device 40.
An electric current path of the solenoid 41 is explained below. The coil 45 of the solenoid 41 is connected to a power supply voltage, and a shunt resistor is connected to one end side of the coil 45. A switch is connected between the coil 45 and the shunt resistor, and the electric current flows in the coil 45 when a switch signal is input. Furthermore, an operational amplifier is connected to both ends of the shunt resistor. The potential difference between the two ends of the shunt resistor is then input to the operational amplifier. Subsequently, the voltage value amplified by the operational amplifier is read by the control module 50 (reading device) connected to the electric current path of the solenoid 41. Accordingly, the electric current flowing in the solenoid 41 can be diagnosed by reading the potential difference in the shunt resistor.
The abnormality diagnosing device 60 includes a diagnosing section 61 that is connected to the control module 50. The diagnosing section 61 functions to diagnose the value of electric current flowing in the solenoid 41. In the present specification, the "electric current flowing in the solenoid 41" refers to the "electric current flowing in the coil 45 of the solenoid 41" that can be measured as explained above. The diagnosing section 61 diagnoses an abnormality in at least one between the operation of the cutting blade 42 and shape of the cutting blade 42 based on a temporal change in the electric current flowing in the solenoid 41. However, the diagnosing section 61 can be configured to diagnose abnormality only in the operation of the cutting blade 42 based on the temporal change in the electric current flowing in the solenoid 41, or can be configured to diagnose abnormality only in the shape of the cutting blade 42 based on the temporal change in the electric current flowing in the solenoid 41. Alternatively, the diagnosing section 61 can be configured to diagnose abnormality both in the operation and the shape of the cutting blade 42 based on the temporal change in the electric current flowing in the solenoid 41. The diagnosing section 61 is constituted as a computer device that includes, for example, a processor such as CPU, memory such as ROM and RAM, a storage, and a communication device. As shown in FIG. 2, the diagnosing section 61 is provided in, for example, the abnormality diagnosing device 60, which is an external device of the yarn monitoring device 1, and is capable of communicating with the yarn monitoring device 1.
The diagnosing section 61 includes an acquiring section 62, an arithmetic section 63, and a determining section 64 as functional elements thereof. For example, the electric signal that indicates the value of the electric current flowing in the solenoid 41 is output from the control module 50. In this manner, the acquiring section 62 acquires the value of the electric current flowing in the solenoid 41. The arithmetic section 63 calculates, based on the value of the electric current flowing to the solenoid 41, various numerical values (electric current value, electric current difference, time, time difference, and standard deviation) related to diagnostic criteria used to diagnose an abnormality in at least one between the operation of the cutting blade 42 and shape of the cutting blade 42. The determining section 64 compares one or more of the numerical value calculated by the arithmetic section 63 with the previously-stored corresponding threshold values, and based on the result of the comparison determines the presence or absence of an abnormality in the operation or the type (to which diagnosable item the type corresponds) of the abnormality in the operation of the cutting blade 42. The determining section 64 compares one or more of the numerical value calculated by the arithmetic section 63 with the previously-stored corresponding threshold values, and based on the result of the comparison determines whether there is an abnormality in the shape of the cutting blade 42. Details of the various numerical values calculated by the arithmetic section 63 and the various threshold values used for the determination performed by the determining section 64 will be explained later. In the diagnosing section 61, a processor executes a predetermined software (computer program) that is loaded into memory, controls the reading and writing of data in memory and storage and communication by communication devices to realize various functional elements of the diagnosing section 61.
The inventors of the present invention found that the electric current flowing in the solenoid 41 shows peculiar waveforms when the operation of the cutting blade 42 is normal or abnormal. Moreover, the inventors of the present invention found that the electric current flowing in the solenoid 41 shows peculiar waveforms when the shape of the cutting blade 42 is normal or abnormal. In the following explanation, both "normal or abnormal operation of the cutting blade 42" and "normal or abnormal shape of the cutting blade 42" will be simply referred to as "normal or abnormal state of the cutting blade 42". FIG. 3 shows a typical example of the temporal change in the electric current flowing in the solenoid 41. In FIG. 3, the horizontal axis indicates time (ms), and the vertical axis indicates current (A). The electric current waveform shown in FIG. 3 is a waveform generated when the cutting blade 42 is operating normally. The time at which the operation command for the cutting blade 42 is output by the control module 50 is 0 (ms) on the horizontal axis.
As shown in FIG. 3, because of a reactance component of the coil 45, the electric current value increases from time 0 (ms) until Point a, an initial maximum value (peak point), is reached. The electric current value (peak electric current value) at Point a is denoted as ia (A). The time (peak time) of Point a is denoted as ta (ms). The electric current value decreases after Point a (after crossing Point a) and reaches Point b, an initial minimum value (valley point). The electric current value (valley electric current value) at Point b is denoted as ib (A). The time (valley time) of Point b is denoted as tb (ms). After Point b (after crossing Point b), the electric current value increases again and reaches Point c, a second maximum value (peak point). The electric current value (peak electric current value) at Point c is denoted as ic (A). The time (peak time) of Point c is denoted as tc (ms). Subsequently, the electric current value decreases gradually. Generally, no maximum values are seen after Point c. However, a second minimum value (valley point), Point b', followed by a third maximum value (peak point) and a third minimum value (valley point) may appear after Point c.
In such a standard waveform, Point a corresponds to an instance around which the plunger 44 starts to move with respect to the coil 45. To be specific, the plunger 44 starts to move little before Point a. In other words, when the electric current is flowing in the solenoid 41 but Point a does not appear, it can be determined that there is an abnormality, such as wiring disconnection or ground fault, in the solenoid 41 cable.
In such a standard waveform, Point b corresponds to an instance at which the plunger 44 bounces back after the cutting blade 42 collides against the second side wall 43b of the anvil 43. For example, if the solenoid 41 does not move due to some reason, like Point b shown in FIG. 3, no point will appear at which the electric current value starts to increase again. Therefore, it can be determined that there is an abnormality based on the presence or absence of Point b.
In such a standard waveform, Point c corresponds to an instance around which the plunger 44 starts moving toward the second side wall 43b again. This is because the capacitor discharge driving is continued after the cutting blade 42 collided against the second side wall 43b of the anvil 43 and the plunger 44 bounced back at Point b. To be specific, the plunger 44 starts to move again little before Point c.
Examples of abnormalities (defects/faults) in the operation of the cutting blade 42 that can be diagnosed by the abnormality diagnosing device 60 are explained below. As a first example, non-movement of the plunger 44 is cited. Non-movement of the plunger 44 is a phenomenon in which the plunger 44 and the cutting blade 42 have a mechanical fault. In this case, the electric current flows in the solenoid 41, but the plunger 44 and the cutting blade 42 do not move (hereinafter referred to as "non-movement"). As a second example, insufficient cutting capability of the cutting blade 42 in cutting the yarn Y (hereinafter, "insufficient cutting capability") is cited. For example, the presence or absence of the insufficient cutting capability is judged at the time of shipment. As a third example, a phenomenon in which the plunger 44 does not return to a waiting position thereof after the cutting blade 42 is operated (hereinafter, "return-defect of cutter") is cited. As a fourth example, a phenomenon in which the electric current does not flow to the solenoid 41 because of the wiring disconnection or ground fault of the solenoid 41 cable (hereinafter, "Non-movement (wiring disconnection or ground fault)") is cited. In a fifth example, a phenomenon in which the efficiency of the cutting blade 42 that cuts the yarn Y deteriorates (hereinafter, "deterioration of cutting efficiency") due to an increase in the frictional force of a sliding part of the solenoid 41 (caused by changes over time, etc.) is cited. The deterioration of cutting efficiency is a type of failure prediction (predictive diagnosis) item. For example, the presence or absence of the deterioration of cutting efficiency is judged at the time of use. As an example of an abnormality (defect) in the shape of the cutting blade 42 that can be diagnosed by the abnormality diagnosing device 60, the deformation of an edge of the cutting blade 42 is cited. For example, the presence or absence of deformation of the edge of the cutting blade 42 is determined at the time of use. Furthermore, in the present specification documents, "non-movement" includes both the meanings that the plunger 44 or the cutting blade 42 does not move at all, or move a little, but does not move to the final position (the position where the cutting blade 42 reaches the second side wall 43b). The "deformation of the blade edge" refers to the deformation of the edge of the cutting blade 42 due to collision.
These diagnosable items can be diagnosed by the diagnosing section 61 of the abnormality diagnosing device 60 based on the diagnostic criteria shown in FIGS. 4 and 5. The diagnosable items are shown in the leftmost column of the table, and the diagnostic criteria are shown in the topmost row of the table. For items diagnosable by the diagnosing section 61, "detectable" is indicated in the table.
As shown in FIG. 4, when the electric current value ib at Point b is lower than the predetermined electric current value (first valley electric current threshold value), the diagnosing section 61 diagnoses insufficient cutting capability, deterioration of cutting efficiency, or deformation of the edge of the cutting blade of the yarn cutting device 40. When the electric current value ib at Point b is higher than the predetermined electric current value (second valley electric current threshold value), the diagnosing section 61 diagnoses return-defect of cutter of the yarn cutting device 40. For example, the first valley electric current threshold value shown in FIG. 3 is set to a value that is lower than the reference valley electric current value read based on the standard (ideal) electric current waveform in the yarn cutting device 40. The second valley electric current threshold value is set to a value higher than the reference valley electric current value.
When the difference in the electric current Δi between Point a and Point b (the difference in electric current between the peak electric current value and the valley electric current value) is the maximum value, the diagnosing section 61 diagnoses the abnormality as the non-movement of the yarn cutting device 40. The maximum value of the difference in electric current is set to a value that is sufficiently high to detect "non-movement" in the yarn cutting device 40 based on, for example, a standard waveform as shown in FIG. 3. The "sufficiently high value" explained here means that the value is higher than a "first electric current difference threshold value" explained later. When the difference in the electric current Δi between Point a and Point b is higher than the predetermined electric current difference (first electric current difference threshold value), the diagnosing section 61 diagnoses that the yarn cutting device 40 has insufficient cutting capability, deterioration of cutting efficiency, or deformation of the edge of the cutting blade. When the difference in the electric current Δi between Point a and Point b is lower than the predetermined electric current difference (second electric current difference threshold value), the diagnosing section 61 diagnoses return-defect of cutter as an abnormality in the yarn cutting device 40. For example, the first electric current difference threshold value is set higher than the reference electric current difference that is read from the standard (ideal) electric current waveform of the yarn cutting device 40 as shown in FIG. 3. The second electric current difference threshold value is set lower than the reference electric current difference. Furthermore, it is explained that the diagnosis can be made based on the difference in electric current between Point a and Point b; however, the diagnosis is not limited to such, and can be made in the same way as explained above based on the difference in the electric current between any two points such as Point a, Point b, Point c, and Point b' (when Point b' appears). In addition to the diagnosis based on the difference in the electric current between the two points, the diagnosis can also be performed in the same way as given above based on the maximum (peak electric current value) and minimum values (valley electric current values) detected after the third time.
When the time (valley time) tb at Point b is equal to the maximum value, the diagnosing section 61 diagnoses that the yarn cutting device 40 is not moving. The maximum value of the time, for example, is set to a value that is sufficiently high to detect "non-movement" based on the standard waveform in the yarn cutting device 40 as shown in FIG. 3. The "sufficiently high value" explained here refers to a value that is higher than a "first valley time threshold value" explained later. When the time tb at Point b is higher than the predetermined time period (first valley time threshold value), the diagnosing section 61 diagnoses insufficient cutting capability, deterioration of cutting efficiency, or deformation of the edge of the cutting blade of the yarn cutting device 40. When the time tb at Point b is lower than the predetermined time period (second valley time threshold value), the diagnosing section 61 diagnoses return-defect of cutter in the yarn cutting device 40. The first valley time threshold value, for example, is set to a value that is higher than the reference valley time that is read from the standard (ideal) electric current waveform in the yarn cutting device 40 as shown in FIG. 3. The second valley time threshold value is set to a value that is lower than the reference valley time. Furthermore, the time tb' at Point b' and the minimum value (valley electric current value) detected after the third time can be diagnosed in the same manner as explained above.
The time (valley time) tb at Point b need not necessarily be based on the time at which the operation command by the control module 50 for the cutting blade 42 is output. In other words, the time at Point a (peak time) can be used as a reference. The time (peak time) at Point a does not change significantly irrespective of deterioration due to aging. Therefore, the time difference between Point a and Point b can be set as the time tb (valley time) at Point b. For the same reason, the time at Point a (peak time), for example, can also be used as a reference time (fixed value) read from a standard (ideal) electric current waveform in the yarn cutting device 40 as shown in FIG. 3.
When the time difference Δt between Point a and Point b (time difference between the peak time and the valley time) is the maximum value, the diagnosing section 61 diagnoses non-movement of the yarn cutting device 40. The maximum value of this time difference is set, for example, to a value that is sufficiently high to detect "non-movement" based on standard waveforms in the yarn cutting device 40 as shown in FIG. 3. The "sufficiently high value" explained here refers to the value that is higher than a "first time difference threshold value" explained later. When the time difference Δt between Point a and Point b is higher than the predetermined time difference (first time difference threshold value), the diagnosing section 61 diagnoses that the yarn cutting device 40 has insufficient cutting capability, deterioration of cutting efficiency, and deformation of the edge of the cutting blade. When the time difference Δt between Point a and Point b is lower than the predetermined time difference (second time difference threshold value), the diagnosing section 61 diagnoses return-defect of cutter in the yarn cutting device 40. The first time difference threshold value is set, for example, higher than the reference time difference value that is read from the standard (ideal) electric current waveform of the yarn cutting device 40 shown in FIG. 3. A second time difference threshold value is set lower than the reference time difference. Furthermore, it is explained that the diagnosis can be made based on the difference in time between Point a and Point b; however, the diagnosis is not limited to such a method, and can be made in the same way as explained above based on the time difference between any two points such as Point a, Point b, Point c, and Point b' (when Point b' appears). Moreover, not only based on the time difference between the two points, but an abnormality can be diagnosed in the same manner as explained above based on the maximum value (peak electric current value) and the minimum value (valley electric current value) detected after the third time.
When Point b does not appear, the diagnosing section 61 diagnoses the non-movement or non-movement (wiring disconnection or ground fault) of the yarn cutting device 40. In such a case, it can be said that the time difference is infinite and cannot be measured, and that Point b cannot be measured. FIG. 6 shows an electric current waveform based on which diagnosis can be performed in the same way. Moreover, if Point a and Point b do not appear, the diagnosing section 61 diagnoses the non-movement (wiring disconnection or ground fault) of the yarn cutting device 40. In such a case, for example, the electric current value (peak electric current value) at Point a is zero, the electric current value (valley electric current value) at Point b is zero, and the time difference between Point a and Point b is infinite. Based on these values, it can be considered that the measurement is not possible, or the electric current difference between Point a and Point b is 0. Although the non-movement (wiring disconnection or ground fault) of the yarn cutting device 40 can only be diagnosed based on the absence of Point a, an abnormality can be diagnosed accurately based on the absence of Points a and b.
Furthermore, as shown in FIG. 5, the standard deviation of various numerical values can also be used for diagnosis by using the value obtained when the yarn cutting device 40 is operated multiple times (used over time). For example, when the standard deviation σia of the electric current values (peak electric current values) at Point a is higher than a predetermined standard deviation (peak current standard deviation threshold value), the diagnosing section 61 diagnoses that the yarn cutting device 40 has insufficient cutting capability or deterioration of cutting efficiency. The peak electric current standard deviation threshold value is set, for example, higher than the reference peak electric current standard deviation that is calculated based on a variation in the peak electric current values shown in the standard (ideal) electric current waveform of the yarn cutting device 40 as shown in FIG. 3 when the yarn cutting device 40 is used multiple times.
Furthermore, when the standard deviation σib of the electric current values (valley electric current values) ib at Point b is higher than a predetermined standard deviation (valley electric current standard deviation threshold value), the diagnosing section 61 diagnoses insufficient cutting capability or deterioration of cutting efficiency in the yarn cutting device 40. The valley current standard deviation threshold value is set, for example, higher than a reference valley electric current standard deviation that is obtained based on the variation in the valley electric current values shown in the standard (ideal) electric current waveform in the yarn cutting device 40 shown in FIG. 3 when the yarn cutting device 40 is used multiple times.
When the standard deviation σΔi of the electric current differences Δi between Point a and Point b is higher than a predetermined standard deviation (electric current difference standard deviation threshold value), the diagnosing section 61 diagnoses insufficient cutting capability or deterioration of cutting efficiency in the yarn cutting device 40. The electric current difference standard deviation threshold value is set, for example, higher than a reference electric current difference standard deviation that is obtained based on the variation in the electric current difference shown in the standard (ideal) electric current waveform in the yarn cutting device 40 shown in FIG. 3 when the yarn cutting device 40 is used multiple times.
When the standard deviation σtb of the times (valley time) tb at Point b is higher than a predetermined standard deviation (valley time standard deviation threshold value), the diagnosing section 61 diagnoses insufficient cutting capability or deterioration of cutting efficiency of the yarn cutting device 40. The valley time standard deviation threshold value is set, for example, higher than a reference valley time standard deviation that is obtained based on the variations in the valley time shown in a standard (ideal) electric current waveform shown in FIG. 3 when the yarn cutting device 40 is used multiple times.
When the standard deviation σΔt of the time differences Δt between Point a and Point b is higher than a predetermined standard deviation (time difference standard deviation threshold value), the diagnosing section 61 diagnoses insufficient cutting capability or deterioration of cutting efficiency of the yarn cutting device 40. The time difference standard deviation threshold value is set, for example, higher than a reference time difference standard deviation that is obtained based on the variation in the time difference shown in the standard (ideal) electric current waveform shown in FIG. 3 when the yarn cutting device 40 is used multiple times.
Furthermore, in the same manner explained above, an abnormality can be diagnosed based on the standard deviation at any of Point c, Point b', maximum values (peak electric current values) or minimum values (valley electric current values) detected after the third time onward.
Alternatively, though not shown in the figure, when the result of comparison between any value of at least one type of the electric current value at Point a, the electric current value at Point b, the electric current difference between Point a and Point b, time of Point b, and the time difference between Point a and Point b, and a reference value of those various values at the time of manufacturing, is higher than a predetermined change amount (change amount threshold value), the diagnosing section 61 diagnoses insufficient cutting capability or deterioration of cutting efficiency in the yarn cutting device 40. The change amount threshold value is set, for example, higher than the reference change amount based on the changes over time shown in the standard (ideal) electric current waveform of the yarn cutting device 40 as shown in FIG. 3. With respect to the reference value, similar diagnosis can be performed based on any of Point c, Point and b', a maximum value (peak electric current value) or a minimum value (valley electric current value) detected after the third time in the same manner explained above.
As explained above, non-movement can be detected by the diagnosing section 61 based on the electric current difference Δi between Point a and Point b, the time tb at Point b, the time difference Δt between Point a and Point b, or the absence (lack) of Point b. The diagnosing section 61 can use all of these diagnostic criteria, or can use only few of these diagnostic criteria. Alternatively, the diagnosing section 61 can use only one of these diagnostic criteria.
The insufficient cutting capability can be detected by the diagnosing section 61 based on the electric current value ib at Point b, the electric current difference Δi between Point a and Point b, the time tb at Point b, the time difference Δt between Point a and Point b, the standard deviation σia of the electric current value at Point a, the standard deviation σib of the electric current value ib (valley electric current value) at Point b, the standard deviation σΔi of the electric current difference Δi between Point a and Point b, the standard deviation σtb of the time tb at Point b, the standard deviation σΔt of the time difference Δt between Point a and Point b, or the amount of change based on the a reference value of those various values at the time of manufacturing explained above. Among these criteria, the electric current value ib, the electric current difference Δi, the time tb, and the time difference Δt are suitable as diagnostic criteria for detecting insufficient cutting capability. The diagnosing section 61 can use all of these diagnostic criteria, or can use a few of these diagnostic criteria. Alternatively, the diagnosing section 61 can only use only one of these diagnostic criteria.
Deterioration of cutting efficiency can be detected by the diagnosing section 61 based on the electric current value ib at Point b, the electric current difference Δi between Point a and Point b, the time tb at Point b, the time difference Δt between Point a and Point b, the standard deviation σia of the electric current value at Point a, the standard deviation σib of the electric current value ib (valley electric current value) at Point b, the standard deviation σΔi of the electric current difference Δi between Point a and Point b, the standard deviation σtb of the time tb at Point b, the standard deviation σΔt of the time difference Δt between Point a and Point b, or on the amount of change based on a reference value of those various values at the time of manufacturing explained above. Among these diagnostic criteria, the standard deviation σia, the standard deviation σib, the standard deviation σΔi, the standard deviation σtb, the standard deviation σΔt, and the amount of change based on a reference value of those various values at the time of manufacturing are suitable as diagnostic criteria for detecting the deterioration of cutting efficiency. The diagnosing section 61 can use all of these diagnostic criteria, or can use a few of these diagnostic criteria. Alternatively, the diagnosing section 61 can use only one of these diagnostic criteria.
The return-defect of cutter is detectable by the diagnosing section 61 based on the electric current value ib at Point b, the electric current difference Δi between Point a and Point b, the time tb at Point b, or the time difference Δt between Point a and Point b. The electric current value ib, the electric current difference Δi, the time tb, and the time difference Δt are suitable as the diagnostic criteria for diagnosing return-defect of cutter. The diagnosing section 61 can use all of these diagnostic criteria, or can use some of these diagnostic criteria. Alternatively, the diagnosing section 61 can only use one of these diagnostic criteria.
Non-movement (wiring disconnection or ground fault) is detectable by the diagnosing section 61 based on the absence (lack) of Point b or the absence of Points a and b (lack of both points). The diagnosing section 61 can use all of these diagnostic criteria, or can use some of these diagnostic criteria. Alternatively, the diagnosing section 61 can only use one of these diagnostic criteria.
A defective assembly of peripheral mechanisms at the time of shipment, for example, can be considered as a specific cause for the occurrence of non-movement, and damage caused by deterioration due to aging can be considered as a specific cause of non-movement after shipment. Poor sliding of the plunger 44 at the time of shipment, for example, can be considered as a specific cause of the insufficient cutting capability. Malfunction of peripheral functions or spring abnormality at the time of shipment can be considered as a specific cause of the return-defect of cutter, and sliding obstruction due to foreign matter can be considered as a specific cause of the cutter return failure after shipment. Biting of cables at the time of shipment, for example, can be considered as a specific cause of the non-movement (wiring disconnection or ground fault). After the shipment, there can be wiring disconnection or peeling of the coating of the wiring due to deterioration over time.
The deformation of the edge of the cutting blade can be detected by the diagnosing section 61 based on the electric current value ib at Point b, the electric current difference Δi between Point a and Point b, the time tb at Point b, or the time difference Δt between Point a and Point b. The diagnosing section 61 can use all of these diagnostic criteria, or can use some of these diagnostic criteria. Alternatively, the diagnosing section 61 can only use one of these diagnostic criteria. Although not shown in the figure, the deformation of the edge of the cutting blade can be detected by the diagnosing section 61 based on the electric current difference (change in the electric current) between Point b and Point c. The diagnosing section 61 can detect the deformation of the edge of the cutting blade only based on the electric current difference between Point b and Point c. In addition to the electric current difference between Point b and Point c, the diagnosing section 61 can detect the deformation of the edge of the cutting blade based on the time tb at Point b (timing of Point b). The diagnosing section 61 can detect the degree of deformation of the edge of the cutting blade by checking the difference in the electric current between Point b and Point c, or between Point b and Point b' (the second minimum value (valley point) explained above). The electric current value at Point b' is lower than the electric current value at Point b. Therefore, checking the current difference between Point b and Point b' refers to checking the attenuation of the rebound of the cutting blade 42. Although it is explained that the diagnosis can be made based on the difference in the electric current between Point b and Point b´, the diagnosis is not limited to such, and can be performed in the same way as explained above based on the difference in the electric current or the time difference between any two points such as Point a, Point b, Point c, and Point b´.
As explained above, predictive diagnosis of a failure of the solenoid 41 can be performed based on the changes in the electric current flowing in the solenoid 41 over time. According to the studies conducted by the inventors of the present invention, the time taken to reach up to the collision point (Point b) in the solenoid 41 extends each time the operation is repeated. This is because, for example, the abrasion powder generated due to friction makes the plunger 44 of the solenoid 41 less slippery, causing it to take longer time to collide. If the time required for collision exceeds a certain value, the yarn cannot be sufficiently cut, and it can be judged that the failure has occurred.
Next, an abnormality diagnosing method of the yarn cutting device 40 will be explained. The abnormality diagnosing device 60 diagnoses an abnormality in the yarn cutting device 40 while a winding operation of the yarn Y is being performed in the winder unit 201. In other words, an abnormality in the yarn cutting device 40 is diagnosed while the state of the yarn Y is being monitored by the yarn monitoring device 1. First, the acquiring section 62 (see FIG. 2) acquires a value of the electric current flowing in the solenoid 41 of the yarn cutting device 40. The acquiring section 62 acquires the value of the electric current flowing in the solenoid 41, for example, for each predetermined time period. The acquiring section 62 stores the acquired electric current value by associating the same with the time at which the electric current value is detected. Furthermore, when storing the electric current value, the detected electric current value is stored by associating the same with a predetermined time period elapsed after the operation command is output, or the time at which the operation command is output once and the capacitor is being discharged.
Based on the electric current value acquired and stored by the acquiring section 62, the arithmetic section 63 calculates different types of numeric values related to the diagnostic criteria explained above. The arithmetic section 63 calculates the initial maximum value (peak point; Point a) of the electric current and a subsequent minimum value (valley point; Point b) based on the electric current value acquired for each predetermined time period. Furthermore, the arithmetic section 63 calculates the peak electric current value, the valley electric current value, the electric current difference, the peak time, the valley time, and the time difference. Moreover, the arithmetic section 63 stores the calculated numeric values and calculates the standard deviation of those values based on the result of the operation of the yarn cutting device 40 (cutting of the yarn Y by the cutting blade 42) over multiple times. The time period used to calculate the standard deviation can be an entire time period elapsed between start of use of the yarn cutting device and the diagnosis, or can be the time period elapsed between the predetermined period after the start of use of the yarn cutting device and the time at which an abnormality is diagnosed.
The determining section 64 compares the numeric value calculated by the arithmetic section 63 and a threshold value stored beforehand. The determining section 64 determines presence or absence of an abnormality in the state of the cutting blade 42 or a type of the abnormality in the state (to which diagnosable item the abnormality corresponds to) in accordance with whether the numeric values are higher or lower than the respective threshold values and the like. With the processing explained above, the diagnosing section 61 diagnoses the abnormality in the state of the cutting blade 42 based on the temporal change in the electric current flowing in the solenoid 41. The abnormality diagnosing device 60 can display the abnormality in the state of the cutting blade 42 on a display device such as a display device of the automatic winder 200 and the like (for example, a display device 205 shown in FIG. 1). The abnormality diagnosing device 60 can notify the abnormality in the state of the cutting blade 42 by generating a warning and the like.
Furthermore, immediately after the blade tip is replaced, the abnormality diagnosing device 60 can execute a test mode in which whether the blade tip is worn out is diagnosed. The abnormality diagnosing device 60 operates the cutting blade 42 in the test mode multiple times and determines whether the electric current waveform is within a normal range. However, a timing at which the test mode is executed is not limited to immediately after the blade tip replacement and can be executed at some other time. The abnormality diagnosing device 60 records the replacement history of the blade tip.
In the abnormality diagnosing device 60 and the abnormality diagnosing method of the yarn cutting device 40 according to the present embodiment, an abnormality in the state of the cutting blade 42 is diagnosed by the diagnosing section 61 based on the temporal change in the electric current flowing in the solenoid 41. The electric current flowing in the solenoid 41 (the electric current waveform) well reflects the movement of the cutting blade 42. Accordingly, in such an abnormality diagnosing device, an abnormality in the state of the cutting blade 42 can be diagnosed accurately.
When the cutting blade 42 starts moving normally, at least the normal peak electric current value is detected. By diagnosing an abnormality in the state of the cutting blade 42 based on the peak electric current value, the abnormality in the state of the cutting blade 42 can be diagnosed more accurately.
When the cutting blade 42 collides normally with the second side wall 43b, which is a metal portion that faces the cutting blade 42, at least the normal valley electric current value is detected. By diagnosing an abnormality in the state of the cutting blade 42 based on the valley electric current value, the abnormality in the state of the cutting blade 42 can be diagnosed more accurately.
By using the electric current difference between the peak electric current value and the valley electric current value, not moving of the cutting blade 42 (non-movement of the cutting blade 42), insufficient cutting capability, return-defect of the cutting blade 42, and the like can be diagnosed suitably.
According to the detected presence or absence of the peak point, not moving of the cutting blade 42 (non-movement of the cutting blade 42) can be diagnosed suitably.
By using the presence or absence of the valley point, not moving of the cutting blade 42 (non-movement of the cutting blade 42) can be diagnosed suitably.
By using the valley time, not moving of the cutting blade 42 (non-movement of the cutting blade 42), insufficient cutting capability, return-defect of the cutting blade 42, and the like can be diagnosed suitably.
By using the time difference between the peak time and the valley time, not moving of the cutting blade 42 (non-movement of the cutting blade 42), insufficient cutting capability, return-defect of the cutting blade 42, and the like can be diagnosed suitably.
Insufficient cutting capability, deterioration of cutting efficiency, and the like can be diagnosed suitably by using the peak electric current value, the valley electric current value, the electric current difference between the peak electric current value and the valley electric current value, the valley time, or the standard deviation of time difference between the peak time and the valley time. Based on the diagnosis of the deterioration of cutting efficiency, failures that have actually occurred at the time of diagnosis and failures that may occur in the future can be predicted. For example, measures (predictive maintenance) such as in-advance replacement of parts (plunger 44 and the like) that constitutes the solenoid 41 can be performed.
Insufficient cutting capability, deterioration of cutting efficiency, and the like can be diagnosed suitably by using the peak electric current value, the valley electric current value, the electric current difference between the peak electric current value and the valley electric current value, or a change in the time difference between the peak time and the valley time with that at the time of manufacturing. Based on the diagnosis of the deterioration of cutting efficiency, prediction of failures explained above becomes possible, and the same measures (predictive maintenance) as explained above can be implemented.
Embodiments of the present invention are explained above; however, the present invention is not limited to the embodiments explained above. For example, based on the determination result, the abnormality diagnosing device 60 can transmit a notification (visual notification using the display device and like and / or an audio notification using a speaker and the like) that prompts an operator to purchase parts. By prompting the operator to purchase parts, parts such as the cutting blade 42 can be replaced before the yarn cutting device 40 breaks down. As a result, operation downtime can be shortened.
The abnormality diagnosing device 60 can transmit a notification that prompts an operator to perform a task in accordance with the occurred phenomenon (abnormality or defect explained above) (visual notification using the display and like and / or an audio notification using a speaker and the like). The abnormality diagnosing device 60 can prompt the operator for an inspection or a replacement depending on the occurred phenomenon. The abnormality diagnosing device 60 can prompt the operator, for example, for the inspection in accordance with the occurrence of return-defect of cutter, or can prompt the operator for the replacement in accordance with the occurrence of wiring disconnection or ground fault.
The abnormality diagnosing device 60 can determine a life level of all the winder units 201 (that is, all spindles) and display the respective life levels in a distinctive manner. The life level of the winder units 201 can be determined in levels that is constituted by several phases. Accordingly, the operator can easily recognize the cutting blade 42 and / or the solenoid 41 of which winder unit 201 is nearing the end of their lifespan.
The electric current waveform explained with reference to the accompanying drawings in the embodiments explained above is derived based on the capacitor discharge driving; however, DC power supply drive can be used instead of the capacitor discharge driving to derive the electric current waveform. The shape of the electric current waveform derived based on the DC power supply is different from that derived based on the capacitor discharge driving. However, the waveforms are the same on the point that the abnormality is diagnosed based on the temporal change in the electric current flowing in the solenoid.
The yarn cutting device 40 explained above is not limited to a type in which the plunger 44 and the cutting blade 42 move reciprocally. The yarn cutting device can be a device that includes a so-called rotary solenoid in which a cutting blade rotates around a rotation shaft and collides with a receiving means of an anvil.
In the yarn monitoring device 1 according to the embodiments explained above, a configuration in which an optical detection unit that includes a light projection section and a light receiving section as the detecting section is cited as an example; however, a capacitance-type detector that includes a measuring capacitor that includes a pair of electrodes facing each other with the yarn Y in between can be used.
The yarn monitoring device 1 according to the embodiments explained above is a detection device that mainly detects uneven thickness of the yarn Y and foreign matter stuck to the yarn Y; however, the present invention is not limited thereto. For example, the yarn monitoring device can be an optical-type fixed length device that detects (monitors) the length of the wound yarn, or can be a tension detecting device that detects (monitors) the tension of the yarn. In other words, the present invention is applicable as long as the yarn monitoring device 1 is a device that monitors the state of the yarn (uneven thickness, foreign matter contamination, length, tension, and the like) and includes wiring for supplying an electric signal or electric power.
The yarn monitoring device 1 according to the embodiments explained above includes one among the optical detection unit and a capacitance-type detecting section; however, the yarn monitoring device 1 can include both of the optical detection unit and the capacitance-type detecting section. In such a configuration, by arranging each detecting section along the running direction of the yarn Y, the state of the yarn Y can be monitored from different positions in the running direction of the yarn Y.
The abnormality diagnosing device 60 that includes a diagnosing section 61 can be provided inside the control module 50 of the yarn monitoring device 1. Moreover, irrespective of where the abnormality diagnosing device 60 that includes a diagnosing section 61 is installed, the control module 50, the shunt resistor, and operational amplifier can be provided in the diagnosing device 60. Moreover, the abnormality diagnosing device 60 that includes the diagnosing section 61 can be provided in a main management device (for example, the main management device 204 shown in FIG. 1) that is provided at a base end of the yarn winding machine and manages the entire yarn winding machine.
The abnormality diagnosing device and the yarn monitoring device that includes the yarn cutting device can be applied to a yarn processing unit other than the winder unit 201. The abnormality diagnosing device and the yarn monitoring device that include the yarn cutting device can be applied to a spinning unit (yarn processing unit) such as an air spinning unit. Even when the yarn processing unit is a spinning unit, a plurality of yarn processing units (units indicated by the reference numeral 201) is arranged in the same manner as explained in the embodiment shown in FIG. 1, and a yarn monitoring device and an abnormality diagnosing device are provided for these yarn processing units.
According to one aspect of the present invention, an abnormality diagnosing device diagnoses an abnormality in a yarn cutting device including a cutting blade operated by a solenoid to cut a yarn by positioning the yarn between a receiving portion and the cutting blade. The abnormality diagnosing device includes a diagnosing section that diagnoses an abnormality in at least one between an operation of the cutting blade and a shape of the cutting blade based on a temporal change in an electric current flowing in the solenoid.
In the above abnormality diagnosing device, the diagnosing section diagnoses an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on a temporal change in the electric current flowing in the solenoid. The electric current flowing in the solenoid (electric current waveform) well reflects the movement of the cutting blade. Accordingly, in such an abnormality diagnosing device, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed accurately.
In the above abnormality diagnosing device, the diagnosing section can diagnose an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on one between a peak electric current value at a peak point at which the electric current flowing in the solenoid reaches a maximum value after an operation command to operate the cutting blade is output, and presence or absence of the peak point. When the cutting blade starts moving normally, at least the normal peak electric current value is detected. By diagnosing an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on the peak electric current value, an abnormality in at least one between the operation of the cutting blade and shape of the cutting blade can be diagnosed more accurately. Moreover, based on the presence or absence of the peak point, no movement of the cutting blade (non-movement of the cutting blade) can be diagnosed suitably.
In the above abnormality diagnosing device, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed by corresponding the peak point to an electric current value when the electric current reaches an initial maximum value. Accordingly, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed based on the initial maximum value.
In the above abnormality diagnosing device, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed by corresponding the peak point to an electric current value when the electric current reaches a subsequent maximum value after the initial maximum value. The subsequent maximum value is a maximum value observed from the second time onward. The subsequent maximum value is not limited to the second maximum value, and can be the third or fourth maximum value. By diagnosing the abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on multiple maximum values, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed more accurately.
In the above abnormality diagnosing device, the diagnosing section can diagnose an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on any of a valley electric current value at a valley point when the electric current flowing in the solenoid reaches a minimum value after the operation command to operate the cutting blade is output, presence or absence of the valley point, and a valley time required to reach the valley point. When the cutting blade normally collides with a metal portion that faces the cutting blade, at least a normal valley electric current value is detected. By diagnosing the abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on the valley electric current value, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed more accurately. Moreover, by using the presence or absence of the valley point, non-movement of the cutting blade can be diagnosed suitably. Furthermore, by using the valley time, non-movement of the cutting blade, insufficient cutting capability, a return-defect of the cutting blade, and the like can be diagnosed suitably.
In the above abnormality diagnosing device, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed by corresponding the valley point to an electric current value when the electric current reaches the initial maximum value, decreases, and then reaches an initial minimum value. Accordingly, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed based on the initial minimum value.
In the above abnormality diagnosing device, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed by corresponding the valley point to the electric current value when the electric current reaches the initial maximum value, decreases, reaches the initial minimum value and then reaches a subsequent minimum value after the initial minimum value. The electric current value that reaches the subsequent initial minimum value is a minimum value observed from the second time onward. The subsequent initial minimum value is not limited to the second minimum value, and can be the third or fourth minimum value. By diagnosing the abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on multiple minimum values, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed more accurately.
In the above abnormality diagnosing device, the diagnosing section can diagnose an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on one between an electric current difference between a peak electric current value at a peak point at which an electric current value of the electric current flowing in the solenoid reaches a maximum value after an operation command to operate the cutting blade is output and a valley electric current value at a valley point at which the electric current value of the electric current reaches a minimum value immediately after the peak point, and a time difference between a peak time, which is the time required to reach the peak point, and a valley time, which is the time required to reach the valley point. By using the electric current difference between the peak electric current value and the valley electric current value, non-movement of the cutting blade, insufficient cutting capability, a return-defect of the cutting blade, and the like can be diagnosed suitably. Moreover, by using the time difference between the peak time and the valley time, non-movement of the cutting blade, insufficient cutting capability, a return-defect of the cutting blade, and the like can be diagnosed suitably.
In the above abnormality diagnosing device, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed by corresponding the peak point to an electric current value when the electric current reaches an initial maximum value, and by corresponding the valley point to an electric current value when the electric current decreases immediately after the peak point and reaches a minimum value. Accordingly, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed based on the initial maximum value and the minimum value.
In the above abnormality diagnosing device, the peak point corresponds to an electric current value when the electric current reaches a subsequent maximum value after the electric current reached an initial maximum value, and the valley point corresponds to an electric current value when the electric current decreases immediately after the peak point is reached, and then reaches the minimum value. The subsequent maximum value is a maximum value observed from the second time onward. The value is not limited to the second maximum value, and can be the third or fourth maximum value. By diagnosing the abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade based on multiple maximum values, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed more accurately.
In the above abnormality diagnosing device, the diagnosing section can diagnose an abnormality in the operation of the cutting blade based on one standard deviation among a peak electric current value at a peak point at which the electric current value of the electric current flowing in the solenoid reaches a maximum value after an operation command to operate the cutting blade is output, a valley electric current value at a valley point at which the electric current value of the electric current decreases and reaches a minimum value after the peak point, an electric current difference between the peak electric current value and the valley electric current value, a valley time that is the time required to reach the valley point, and a time difference between a peak time, which is the time required to reach the peak point, and the valley time. By using at least one standard deviation among the peak electric current value, the valley electric current value, the electric current difference between the peak electric current value and the valley electric current value, the valley time, and the time difference between the peak time and the valley time, insufficient cutting capability, deterioration of cutting efficiency, and the like can be diagnosed suitably.
In the above abnormality diagnosing device, the diagnosing section can diagnose an abnormality in the operation of the cutting blade based on comparison between at least one present value and a reference value of the one present value at the time of manufacturing. The one present value can be selected from among a peak electric current value at a peak point at which the electric current value of the electric current flowing in the solenoid reaches a maximum value after an operation command to operate the cutting blade is output, a valley electric current value at a valley point at which the electric current value of the electric current decreases and reaches a minimum value after the peak point, an electric current difference between the peak electric current value and the valley electric current value, a valley time that is the time required to reach the valley point, and a time difference between a peak time, which is the time required to reach the peak point, and the valley time. Insufficient cutting capability, deterioration of cutting efficiency, and the like can be diagnosed suitably by comparing at least one of the peak electric current value, the valley electric current value, the electric current difference between the peak electric current value and the valley electric current value, the valley time, and the time difference between the peak time and the valley time, with a reference value of those various values at the time of manufacturing. Instead of the value at the time of manufacturing, a value at the time of shipment from the factory can be used. Instead of the value at the time of manufacturing, a value when the use of the yarn cutting device is started can be used. The change in the present value from the value at the time of manufacturing can be replaced with a change in the present value compared with the value when the use of the yarn cutting device was started.
In the above abnormality diagnosing device, the diagnosing section can diagnose an abnormality in the shape of the cutting blade based on one among a valley electric current value at a valley point at which the electric current value of the electric current flowing in the solenoid reaches a minimum value after an operation command to operate the cutting blade is output, an electric current difference between a peak electric current value at a peak point at which the electric current value of the electric current reaches a maximum value immediately before the valley point and the valley electric current value, a valley time that is the time required to reach the valley point, and a time difference between a peak time, which is the time required to reach the peak point, and the valley time. By using the valley electric current value, the electric current difference between the peak electric current value and the valley electric current value, the valley time at the valley point, or the time difference between the peak time and the valley time, deformation of the edge of the cutting blade can be diagnosed suitably.
In the above abnormality diagnosing device, the yarn cutting device is included in a yarn monitoring device that monitors a state of the yarn that is running through a yarn passage during a winding operation of the yarn, and the yarn monitoring device can output an operation command to operate the cutting blade based on a result of the monitoring. Accordingly, an abnormality in at least one between an operation of the cutting blade and a shape of the cutting blade in the yarn monitoring device that monitors a state of the yarn can be diagnosed.
The above abnormality diagnosing device can include a shunt resistor that is connected to the solenoid; an operational amplifier that is connected to both ends of the shunt resistor to amplify an input electric voltage; and a reading device that reads an electric voltage value amplified by the operational amplifier. The diagnosing section can diagnose a temporal change in the electric current flowing in the solenoid based on the electric voltage value read by the reading device. Accordingly, even when the electric current flowing in the solenoid cannot be measured directly, the electric current flowing in the solenoid can be diagnosed by reading an electric potential difference in the shunt resistor.
According to another aspect of the present invention, an abnormality diagnosing method is implemented on a yarn cutting device in which a cutting blade is operated by a solenoid and a yarn is cut by positioning the yarn between a receiving portion and the cutting blade. In the above abnormality diagnosing method, an abnormality in at least one between an operation of the cutting blade and a shape of the cutting blade is diagnosed based on a temporal change in an electric current flowing in the solenoid.
In the above abnormality diagnosing method, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade is diagnosed based on a temporal change in the electric current flowing in the solenoid. The electric current flowing in the solenoid (electric current waveform) well reflects the movement of the cutting blade. Accordingly, in such an abnormality diagnosing method, an abnormality in at least one between the operation of the cutting blade and the shape of the cutting blade can be diagnosed accurately.
According to the present invention, an abnormality in at least one between an operation of a cutting blade and a shape of a cutting blade can be diagnosed accurately.
In the above explanation, the meaning of "a plurality of" also includes "a predetermined number of".
Although the invention has been explained with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the scope of the claims.