Description:TECHNICAL FIELD
[0001] The present invention mainly relates to a supply apparatus for supplying a yarn winding machine with a bobbin wound with a yarn spun by a spinning machine.

BACKGROUND ART
[0002] Patent Document 1 is JP 2012-184075 A. Patent Document 2 is JP 2016-3066 A.
[0003] A yarn-supplying bobbin supply apparatus of Patent Document 1 includes a bobbin insertion unit, a bobbin extraction unit, and a tray placement unit. Bobbins transported in a container are inserted into the bobbin insertion unit. The bobbin extraction unit picks up the inserted bobbins one by one, separates such bobbins into individual bobbins, and hands over such individual bobbins to the tray placement unit. The tray placement unit places the bobbins received from the bobbin extraction unit onto a tray. The bobbins placed on the tray are transported to a yarn winding machine by a conveyor.
[0004] Patent Document 2 discloses a yarn-supplying bobbin supply apparatus similar to that of Patent Document 1. The yarn-supplying bobbin supply apparatus of Patent Document 2 includes bobbin detection sensors at various locations on a bobbin transport passage.

SUMMARY OF INVENTION
[0005] Each bobbin detection sensor is used, for example, to determine whether to permit transport of a bobbin. Specifically, if it is determined that a bobbin is not present at a transport destination, the transport of the bobbin is permitted. If it is determined that a bobbin is present at a transport destination, the transport of the bobbin is not permitted. Therefore, a transport device is stopped until it is determined that no bobbin is present at the transport destination. However, with such a method, the transport device is frequently stopped, and as a result, a bobbin supplying efficiency is decreased.
[0006] The present invention is made in view of the above circumstances, and a primary object thereof is to provide a supply apparatus capable of avoiding a decrease in bobbin supplying efficiency caused by a frequent stop of a transport device.
[0007] The problem to be solved by the present invention is thus described, and next, the means for solving such a problem and the effects thereof are described.
[0008] According to an aspect of the present invention, a supply apparatus having the following configuration is provided. That is, the supply apparatus supplies a yarn winding machine with a bobbin formed by winding a yarn spun by a spinning machine around a core tube. The supply apparatus includes a first conveyor, a second conveyor, an arrival sensor, and a control device. The first conveyor separates a plurality of the bobbins into individual bobbins and transports such a bobbin individually. The second conveyor transports the bobbin received from the first conveyor. The arrival sensor detects the bobbin at a position in the second conveyor, the position being an arrival position, where the arrival position is a position at which the bobbin is handed over from the first conveyor. The control device determines whether the bobbin is present at the arrival position, based on a continuous detection time period during which the bobbin is continuously detected at the arrival position. One of conditions for stopping the first conveyor includes determining that the bobbin is present at the arrival position. When the second conveyor is in operation, the control device determines that the bobbin is present at the arrival position as a result of the continuous detection time period reaching a first threshold value. When the second conveyor is stopped, the control device determines that the bobbin is present at the arrival position as a result of the continuous detection time period reaching a second threshold value. The first threshold value is longer than the second threshold value.
[0009] When the second conveyor is in operation, the bobbin is transported by the second conveyor, and thus, there is a high possibility that the bobbin is transported from the arrival position if a certain time elapses. Therefore, when the first threshold value is made longer than the second threshold value, a frequency at which it is determined that the bobbin is present at the arrival position is lowered. Therefore, the first conveyor does not stop frequently, and thus, it is possible to avoid a decrease in a bobbin supply efficiency.
[0010] The above-mentioned supply apparatus preferably has the following configuration. That is, the supply apparatus includes a transit sensor configured to detect the bobbin at a position in the second conveyor, the position being a transit position, where the transit position is downstream of the arrival position in a transport direction of the bobbin. When the second conveyor is in operation, the control device determines that a condition for stopping the first conveyor is satisfied when determining that the bobbin is present at the arrival position irrespective of whether the bobbin is present at the transit position. When the second conveyor is stopped, the control device determines that the condition for stopping the first conveyor is satisfied when determining that the bobbin is present at at least one of the arrival position and the transit position.
[0011] When the second conveyor is in operation, the bobbin at the transit position is immediately transported downstream from the transit position. Therefore, when a detection result of the transit sensor is not considered, it is possible to avoid the first conveyor from stopping at an unnecessary timing.
[0012] The above-mentioned supply apparatus preferably has the following configuration. That is, the supply apparatus includes a supply sensor configured to detect the bobbin at a position in the first conveyor, the position being a supply position, where the supply position is a position at which the bobbin is handed over to the second conveyor. One of conditions for stopping the first conveyor includes the supply sensor detecting the bobbin.
[0013] If there is no bobbin at the supply position, even when the first conveyor is continuously operated, the bobbin is not supplied from the first conveyor to the second conveyor. Therefore, when the above process is performed, it is possible to avoid the first conveyor from stopping at an unnecessary timing.
[0014] In the supply apparatus, a condition for restarting the operation of the first conveyor that is stopping preferably includes the control device determining that the bobbin is not present at either the arrival position or the transit position.
[0015] As a result, it is possible to restart the operation of the first conveyor at a timing when the bobbins do not overlap on the second conveyor.
[0016] The above-mentioned supply apparatus preferably has the following configuration. That is, a time period during which the bobbins are not detected continuously at the arrival position or the transit position is referred to as continuous non-detection time period. When the second conveyor is in operation, the condition for restarting the operation of the stopped first conveyor includes the continuous non-detection time periods of the arrival position and the transit position reaching a first restart threshold value. When the second conveyor is stopped, the condition for restarting the operation of the stopped first conveyor includes the continuous non-detection time periods of the arrival position and the transit position reaching a second restart threshold value. The first restart threshold value is shorter than the second restart threshold value.
[0017] When the second conveyor is in operation, the detected bobbin is immediately transported to the downstream side, and thus, when the continuous non-detection time period is shortened, it is possible to quickly restart the operation of the first conveyor.
[0018] The above-mentioned supply apparatus preferably has the following configuration. That is, the control device calculates an estimated number of bobbins that is an estimated value of the number of bobbins present in an upstream region that is a region from an upstream end to a midway portion of the second conveyor. The control device stops the first conveyor when the time period during which the estimated number of bobbins is two continuously exceeds an upper limit threshold value.
[0019] As a result, if there is a possibility that the bobbins overlap in the upstream region, it is possible to avoid a situation where an additional bobbin is supplied to the second conveyor.
[0020] In the above-mentioned supply apparatus, it is preferable that the control device drives the second conveyor in the reverse direction to discharge the bobbin present in the upstream region if a time period during which the estimated number of bobbins is two continuously exceeds an upper limit threshold value.
[0021] As a result, if the bobbins overlap in the upstream region, the apparatus is capable of eliminating the overlap of bobbins.
[0022] In the above-mentioned supply apparatus, it is preferable that the control device increases the estimated number of bobbins by one if the bobbin is supplied from the first conveyor to the second conveyor.
[0023] As a result, it is possible to appropriately calculate an increase in the number of bobbins in the upstream region.
[0024] The above-mentioned supply apparatus preferably has the following configuration. That is, the control device decreases the estimated number of bobbins by one as a result of the arrival sensor being switched from a state in which the bobbin is detected to a state in which the bobbin is not detected.
[0025] As a result, it is possible to appropriately calculate the decrease in the number of bobbins in the upstream region.

BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1 is a side cross-sectional view of a supply apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of an individualization unit.
FIG. 3 is a perspective view of the individualization unit and a transport unit.
FIG. 4 is a block diagram of a configuration where a process for driving a first conveyor and a second conveyor is performed.
FIG. 5 is a flowchart illustrating a process for determining whether to stop the first conveyor while the first conveyor is in operation.
FIG. 6 is a flowchart illustrating a process for determining whether to restart an operation of the first conveyor while the first conveyor is stopped.
FIG. 7 is a flowchart illustrating a process related to the estimated number of bobbins in an upstream region of the second conveyor.

DESCRIPTION OF EMBODIMENTS
[0027] Next, with reference to the drawings, embodiments of the present invention will be described.
[0028] Firstly, with reference to FIG. 1 to FIG. 4, an overview of a supply apparatus 1 will be described. In the following description, an upstream and a downstream in a direction in which a bobbin 91 is transported are simply referred to as upstream and downstream.
[0029] The supply apparatus 1 supplies the bobbin 91 to a yarn winding machine such as an automatic winder. The bobbin 91 is a yarn-supplying bobbin formed by winding a yarn spun by a spinning machine around a core tube. The yarn winding machine winds the yarn wound around the bobbin 91 to form a package. As illustrated in FIG. 1, the supply apparatus 1 includes a reception unit 10, an individualization unit 20, a setting unit 30, a control device 40, and a transport unit 50.
[0030] A housing body 90 illustrated in FIG. 1 houses a plurality of the bobbins 91 formed by a spinning machine. The housing body 90 is a box-shaped member with a top side formed thereon with an opening. When the housing body 90 is inclined by an operator or an unillustrated loading device so that the opening faces downward, the plurality of bobbins 91 housed in the housing body 90 are loaded into the reception unit 10.
[0031] The reception unit 10 includes a retention part 11, a restriction part 12, and a slope part 13. Each bobbin 91 loaded from the housing body 90 is temporarily retained in the retention part 11. The retention part 11 has an inclined surface with its height decreasing toward the downstream side so that it is possible to transport the bobbin 91 by its own weight. It is noted that the bobbin 91 may be transported by using a conveyor instead of the inclined surface.
[0032] The restriction part 12 is provided between the retention part 11 and the slope part 13 in a transport direction of the bobbin 91. The restriction part 12 is capable of being raised and lowered by a mechanism described later. As the restriction part 12 raises and lowers, the restriction part 12 changes its position between a raised state and a lowered state. While the restriction part 12 is in the raised state, movement of the bobbin 91 is prevented. While the restriction part 12 is in the lowered state, movement of the bobbin 91 is allowed. When the restriction part 12 switches between the raised state and the lowered state at a predetermined timing, it is possible to adjust an amount of bobbins 91 to be supplied from the retention part 11 to the slope part 13.
[0033] The slope part 13 has an inclined surface with its height decreasing toward the downstream side. The slope part 13 transports the bobbin 91 by its own weight. The bobbin 91 rolls or slides down on the slope part 13 in a state in which the bobbin 91 falls down and is supplied to the individualization unit 20. The state in which the bobbin 91 falls down means that the bobbin 91 does not stand upright from a transport surface (such as an inclined surface), and an axial direction of the bobbin 91 is parallel or substantially parallel to the transport surface.
[0034] The individualization unit 20 separates the plurality of bobbins 91 supplied from the slope part 13 of the reception unit 10 into individual bobbins 91 and transports each of the bobbin 91 one by one. The bobbin 91 transported by the individualization unit 20 is transported to the setting unit 30 via the transport unit 50.
[0035] As illustrated in FIG. 2 and FIG. 3, the individualization unit 20 includes a first conveyor 21 configured to transport the bobbins 91 upward. The first conveyor 21 includes a first belt 22, two rotating rollers 23 arranged above and below, and a first drive unit 24.
[0036] The first belt 22 is a band-shaped (sheet-shaped) member. The first belt 22 is bridged across the two rotating rollers 23 in a looped shape. The upper rotating roller 23 is rotationally driven by the first drive unit 24. In the present embodiment, the first drive unit 24 is a stepping motor. The control device 40 operates the first drive unit 24 by transmitting a control command. Rotation of an output shaft of the stepping motor is transmitted to the upper rotating roller 23 via a drive transmission belt or the like. As a result, the first belt 22 is driven to circulate in a vertical direction.
[0037] A support stand 25 is provided on an outer surface of the first belt 22. The support stand 25 includes a plurality of the support stands 25 each provided at equal intervals in a longitudinal direction of the first belt 22. The support stand 25 moves integrally with the first belt 22 in the vertical direction. The support stand 25 scoops up the bobbin 91 loaded by the slope part 13 into the individualization unit 20. As a result, the bobbin 91 is placed on the support stand 25. The support stand 25 supports the bobbin 91 placed thereon and transports the bobbin 91 upward. The support stand 25 has a rectangular surface so that the bobbin 91 in a fallen state is placed thereon. Such a rectangular support stand 25 is attached to the first belt 22 so that a longitudinal direction of the support stand 25 runs along a width direction of the first belt 22.
[0038] A slit 26 is formed in the support stand 25. The slit 26 includes a plurality of the slits 26 formed side by side in the longitudinal direction of the support stand 25. A separation member 27 passes through each of the plurality of slits 26. The separation member 27 is, for example, a metal wire. However, the separation member 27 is not limited to a metal wire.
[0039] As illustrated in FIG. 2, the separation member 27 includes, in order from the bottom, a first straight part 61, a first protrusion 62, a second straight part 63, and a second protrusion 64. The first straight part 61 prevents the bobbin 91 loaded by the slope part 13 from contacting the first belt 22. The first protrusion 62 protrudes toward a distal end of the support stand 25 compared to the first straight part 61. When two of the plurality of bobbins 91 are placed on the support stand 25, a posture of the bobbin 91 placed on the top is disrupted by the first protrusion 62, and thus, the bobbin 91 placed on the top drops. As a result, one bobbin 91 is placed on one support stand 25 on the first conveyor 21 (that is, the bobbins 91 are individualized). The second straight part 63 is located closer to a root side of the support stand 25 compared to the first protrusion 62. The second protrusion 64 protrudes toward the distal end side of the support stand 25 compared to the second straight part 63. The second protrusion 64 causes the bobbin 91 placed and transported on the support stand 25 to drop. The bobbin 91 dropped by the second protrusion 64 is transported to the transport unit 50 by an inclined surface 29.
[0040] As illustrated in FIG. 3, an end 25a of the support stand 25 in the longitudinal direction is located outside a region where the bobbin 91 is transported. The individualization unit 20 includes a stop position sensor 71 configured to detect the end 25a. The stop position sensor 71 is attached not to the first belt 22 but to a frame of the individualization unit 20 or the like. The stop position sensor 71 is, for example, a contact type sensor or a non-contact type sensor (such as a magnetic sensor or an optical sensor). The stop position sensor 71 transmits a detection result to the control device 40. In a state where the first belt 22 is driven, the end 25a moves together with the first belt 22, but a position of the stop position sensor 71 remains unchanged. Therefore, the stop position sensor 71 detects the end 25a only at a timing when the end 25a reaches a predetermined position. A position of the support stand 25 when the stop position sensor 71 detects the end 25a is referred to as a stoppable position. In the individualization unit 20, the support stand 25 being positioned at the stoppable position is one of conditions for stopping the first conveyor 21. A reason why such a condition is set is that the individualization unit 20 is so designed that if the first conveyor 21 is stopped when the support stand 25 is at the stoppable position, the support stand 25 configured to hand over the bobbins 91 stops at a most appropriate position for hand over.
[0041] The stop position sensor 71 is also used as a sensor configured to detect that the first conveyor 21 is not operating normally. That is, in a state where the first belt 22 is driven, the stop position sensor 71 alternately repeats detection and non-detection of the end 25a. On the other hand, in a state where the first belt 22 is not driven, the detection result of the stop position sensor 71 remains unchanged. That is, the stop position sensor 71 maintains a state in which the stop position sensor 71 continues to detect the end 25a, or maintains a state in which the stop position sensor 71 does not detect the end 25a. If the detection result of the stop position sensor 71 remains unchanged, the control device 40 cannot detect the operation of the first conveyor 21. In such a case, it is determined that the reason why the bobbin 91 is not being supplied to the arrival position is that the bobbin 91 interferes with mechanical parts and is not capable of operating normally, and the first conveyor 21 is reversed. As a result, it is possible to eliminate the interference and restart the normal operation.
[0042] As illustrated in FIG. 2, a supply sensor 72 is provided in a region where the bobbin 91 placed on the support stand 25 is transported and also in a region where the second straight part 63 is provided. The supply sensor 72 is a contact type sensor configured to detect the bobbin 91 transported by the support stand 25. The supply sensor 72 is provided at a position passing through the slit 26 and does not contact the support stand 25, but contacts the bobbin 91 placed on the support stand 25. The supply sensor 72 is not limited to a contact type sensor, but may be a non-contact type sensor. A position of the bobbin 91 transported by the individualization unit 20, which is a position around the second protrusion 64 is referred to as a supply position. In a state where the bobbin 91 is present at the supply position, the bobbin 91 is supplied to the transport unit 50 by the second protrusion 64 within a short period of time. The supply sensor 72 detects whether the bobbin 91 is present at the supply position, and transmits a detection result to the control device 40.
[0043] The transport unit 50 transports the bobbins 91 supplied from the individualization unit 20 to the setting unit 30. As illustrated in FIG. 3, the transport unit 50 includes a second conveyor 51. The second conveyor 51 includes a second belt 52 and a second drive unit 53. When an unillustrated pulley is driven with a power generated by the second drive unit 53, the second belt 52 wound around the pulley is driven. As a result, the second conveyor 51 carries the bobbin 91 on the second belt 52 to transport the bobbin 91. The second drive unit 53 is controlled by the control device 40. It is noted that a direction indicated by a thick arrow in FIG. 3 is a driving direction of the second belt 52 when the bobbin 91 is transported toward the setting unit 30. Hereinafter, such a direction is referred to as a forward direction, and the opposite direction is referred to as a reverse direction. In transmitting a control command, the control device 40 is capable of driving the second conveyor 51 in the forward direction or in the reverse direction. An end in the reverse direction of the second conveyor 51 is formed with an opening 54 through which the bobbin 91 is dropped and returned to the slope part 13.
[0044] A position in the second conveyor 51, which is a position at which the bobbin 91 supplied from the individualization unit 20 arrives, is referred to as an arrival position. That is, the arrival position is a position in the second conveyor 51 near the inclined surface 29. Near the arrival position, an arrival sensor 73 configured to detect whether the bobbin 91 is present at the arrival position is provided. A position in the second conveyor 51, which is a position downstream from the arrival position, is referred to as a transit position. Near the transit position, a transit sensor 74 configured to detect whether the bobbin 91 is present at the transit position is provided. The arrival sensor 73 and the transit sensor 74 are non-contact type sensors, for example, optical sensors. The arrival sensor 73 and the transit sensor 74 may be cameras. The arrival sensor 73 and the transit sensor 74 may be contact type sensors. The arrival sensor 73 and the transit sensor 74 transmit detection results to the control device 40. A region from an upstream end to a middle part of the second conveyor 51 is referred to as an upstream region. The arrival position and the transit position are included in the upstream region.
[0045] The setting unit 30 sets the bobbin 91 supplied from the individualization unit 20 on the tray 92. The tray 92 is movable along a transport path 93 configured by a conveyor or the like. The bobbin 91 moves along the transport path 93 while being set on the tray 92, and is supplied to a yarn winding machine.
[0046] The control device 40 illustrated in FIG. 4 includes an arithmetic device such as a CPU, a RAM, and a storage. The storage is an HDD, an SSD, a flash memory, or the like. The storage stores therein a program related to the supply apparatus 1 and data such as a condition necessary for executing such a program. The arithmetic device reads the program stored in the storage into the RAM and executes such a program. As a result, the control device 40 performs various controls for the restriction part 12, the individualization unit 20, and the setting unit 30.
[0047] Next, a process for the operation and the stop of the first conveyor 21 will described.
[0048] The control device 40 changes the operation and the stop of the second conveyor 51, depending on a transport status of the bobbin 91 present downstream of the transport unit 50 or in the setting unit 30 or the like. For example, if the number of bobbins 91 present downstream of the transport unit 50 or in the setting unit 30 is greater than a threshold value, or if the bobbin 91 is already present at a transport destination of the second conveyor 51, the second conveyor 51 is temporarily stopped.
[0049] Therefore, even if the first conveyor 21 supplies the bobbin 91 to the arrival position, the bobbin 91 is not immediately transported downstream when the second conveyor 51 is stopped. If the first conveyor 21 supplies another bobbin 91 to the arrival position in a situation where the bobbin 91 is present at the arrival position, a problem may occur because the two bobbins 91 are present at the arrival position. It is noted that in the following description, a state in which the two or more bobbins 91 are present at a predetermined position on the second conveyor 51 is referred to as an overlap of bobbins 91. In order to avoid the overlap of the bobbins 91, the control device 40 temporarily stops the first conveyor 21 when determining that the bobbin 91 is present at the arrival position.
[0050] However, it may take time to switch between operating and the stop the first conveyor 21, and thus, if the first conveyor 21 is stopped frequently, the efficiency of supplying the bobbin 91 decreases. In particular, in the present embodiment, if the first conveyor 21 is temporarily stopped, a stop position of the support stand 25 is determined depending on a control relationship. Therefore, a time period required to switch between the operation and the stop of the first conveyor 21 is long, and thus, the efficiency of supplying the bobbin 91 is likely to decrease. As described above, when the frequency of stops of the first conveyor 21 is decreased, it is possible to avoid a decrease in efficiency of supplying the bobbin 91.
[0051] Whether the bobbin 91 is present at the arrival position is determined based on the detection result of the arrival sensor 73. In order to prevent a malfunction, the control device 40 determines that the bobbin 91 is present at the arrival position when the time period for the arrival sensor 73 to detect the bobbin 91 exceeds a threshold value. Here, if the second conveyor 51 is in operation, even if the arrival sensor 73 detects the bobbin 91, there is a high possibility that the bobbin 91 immediately moves downstream and the bobbin 91 is removed from the arrival position. On the other hand, when the second conveyor 51 is stopped and the bobbin 91 is present at the arrival position, there is a high possibility that the bobbin 91 continues to be present at the arrival position.
[0052] In consideration of the above, in the present embodiment, the above threshold value is made different depending on whether the second conveyor 51 is in operation or stopped. Specifically, a first threshold value that is a threshold value when the second conveyor 51 is in operation is longer than a second threshold value that is a threshold value when the second conveyor 51 is stopped. For example, when the second conveyor 51 is in operation, a normal time period for the arrival sensor 73 to detect the bobbin 91 is preferably shorter than the first threshold value. As a result, when the second conveyor 51 is in operation, if the bobbin 91 is normally transported, the first conveyor 21 does not stop in principle. As described above, the frequency of stopping of the first conveyor 21 is decreased, and thus, it is possible to avoid a decrease in efficiency of supplying the bobbin 91.
[0053] With reference to the flowchart of FIG. 5, a process of determining whether to stop the operation of the first conveyor 21 will be described below. The process illustrated in FIG. 5 is performed by the control device 40.
[0054] The control device 40 determines whether the bobbin 91 is present at the supply position (S101). Such a determination is made based on the detection result of the supply sensor 72. If the supply sensor 72 does not detect the bobbin 91, the control device 40 determines that there is no bobbin 91 at the supply position. If there is no bobbin 91 at the supply position, there is no possibility that the bobbins 91 overlaps, and thus, there is no need to stop the first conveyor 21. Therefore, the control device 40 does not perform subsequent processes. On the other hand, if the supply sensor 72 detects the bobbin 91, the control device 40 determines that the bobbin 91 is present at the supply position. If the bobbin 91 is present at the supply position, the bobbins 91 may overlap. Therefore, the control device 40 performs the following process.
[0055] The control device 40 determines whether the support stand 25 is at the stoppable position (S102). Such a determination is made based on the detection result of the stop position sensor 71. As described above, when the stop position sensor 71 detects the end 25a, the support stand 25 is at the stoppable position. Therefore, the control device 40 performs the following process.
[0056] The control device 40 determines whether the second conveyor 51 is in operation (S103). The control device 40 is driving the second conveyor 51, and thus, the control device 40 is capable of determining whether the second conveyor 51 is in operation, based on the control command. As described above, such a process is a process for determining whether to use the first threshold value or the second threshold value when determining whether the bobbin 91 is present at the arrival position.
[0057] If the second conveyor 51 is in operation, the control device 40 determines that a time period during which the arrival sensor 73 continuously detects that the bobbin 91 is present at the arrival position (hereinafter referred to as a continuous detection time period at the arrival position) reaches the first threshold value (S104). If the continuous detection time period at the arrival position reaches the first threshold value, the control device 40 determines that the bobbin 91 is present at the arrival position and stops the first conveyor 21 (S105). As described above, the first threshold value is longer than the second threshold value, and thus, a situation in which the first conveyor 21 is stopped is unlikely to occur. On the other hand, if the continuous detection time period at the arrival position does not reach the first threshold value, the bobbin 91 may not be present at the arrival position or the bobbin 91 may be present in a so short period of time that the bobbin 91 is immediately transported to the downstream. Therefore, the control device 40 does not stop the first conveyor 21.
[0058] If the second conveyor 51 is not in operation, the control device 40 determines whether the continuous detection time period at the arrival position reaches the second threshold value (S106). If the continuous detection time period at the arrival position reaches the second threshold value, the control device 40 determines that the bobbin 91 is present at the arrival position and stops the first conveyor 21 (S105). On the other hand, if the continuous detection time period at the arrival position does not reach the second threshold value, it is considered that the bobbin 91 is not present at the arrival position, but the bobbin 91 may be present at the transit position, and thus, the control device 40 performs the following process.
[0059] The control device 40 determines whether a continuous detection time period at the transit position reaches the third threshold value (S107). The third threshold value is used to determine the presence of the bobbin 91 while the second conveyor 51 is not in operation, and thus, the third threshold value may be the same value as the second threshold value. However, the third threshold value and the second threshold value may be different values. If the continuous detection time period at the transit position reaches the third threshold value, the control device 40 determines that the bobbin 91 is present at the transit position, and stops the first conveyor 21 (S108). On the other hand, if the continuous detection time period at the transit position does not reach the third threshold value, it is considered that the bobbin 91 is not present at both the arrival position and the transit position, and thus, there is no need to stop the first conveyor 21.
[0060] In the present embodiment, if the second conveyor 51 is in operation, it is determined whether to stop the first conveyor 21 without determining whether the bobbin 91 is present at the transit position. This is because even if the bobbin 91 is present at the transit position, the second conveyor 51 transports the bobbin 91 to the downstream side, and thus, the bobbins 91 hardly overlap. On the other hand, if the second conveyor 51 is stopped, there is a possibility that the bobbin 91 present at the transit position continues to be present at the transit position, and thus, even if the bobbin 91 is present at the transit position, the control device 40 stops the first conveyor 21.
[0061] Thus, in the present embodiment, preconditions for stopping the first conveyor 21 are (1) that the bobbin 91 is present at the supply position, and (2) that the support stand 25 is present at the stoppable position. A further condition is that, if the second conveyor 51 is in operation, (3) the continuous detection time period at the arrival position reaches the first threshold value. If the second conveyor 51 is stopped, a further condition is (4) that the continuous detection time period at the arrival position reaches the second threshold value, or (5) that the continuous detection time period at the transit position reaches the third threshold value. Such conditions are just examples, and for example, the conditions (1), (2), or (5) above may be omitted. The order in which such conditions are determined is merely an example, and may be changed. For example, it may be determined that any one of the conditions (3) to (5) is satisfied first, and then, the first conveyor 21 may be stopped at a timing when it is determined that the condition (2) is satisfied.
[0062] Next, with reference to the flowchart in FIG. 6, a process for restarting the temporarily stopped operation of the first conveyor 21 will be described. A flowchart in FIG. 6 is performed by the control device 40.
[0063] If the operation of the first conveyor 21 is restarted in a state where the bobbin 91 is present at the arrival position or the transit position, the bobbins 91 may overlap. Therefore, if the control device 40 determines that the bobbin 91 is not present at either the arrival position or the transit position, the control device 40 restarts the operation of the first conveyor 21. The determination that the bobbin 91 is not present is similar to the determination that the bobbin 91 is present. That is, the control device 40 determines that the bobbin 91 is not present at the arrival position or the transit position if a time period during which the bobbin 91 is not continuously detected at the arrival position or the transit position reaches a restart threshold.
[0064] If the second conveyor 51 is in operation, the bobbin 91 is transported downstream by the second conveyor 51 from a timing at which the bobbin 91 is no longer detected at the arrival position and the transit position. Therefore, if the second conveyor 51 is in operation, even if the first conveyor 21 restarts the operation at a relatively early timing after the bobbin 91 is no longer detected at the arrival position and the transit position, the bobbins 91 may overlap. Therefore, in the present embodiment, the above-mentioned restart threshold value is made different depending on whether the second conveyor 51 is in operation or not. Specifically, the first restart threshold value that is the restart threshold value when the second conveyor 51 is in operation is shorter than the second restart threshold value that is the restart threshold value when the second conveyor 51 is stopped. As a result, it is possible to restart the operation of the first conveyor 21 at an early timing, and thus, it is possible to avoid a decrease in supply efficiency of the bobbins.
[0065] A process will be described according to a flowchart illustrated in FIG. 6, below. The control device 40 determines whether the second conveyor 51 is in operation (S201). Such a process is a process for differentiating the restart threshold used when determining whether the bobbin 91 is present at the arrival position and the transit position.
[0066] If the second conveyor 51 is in operation, the control device 40 determines whether a time period during which the bobbin 91 is not detected continuously at the arrival position and the transit position (hereinafter, a continuous non-detection time period at the arrival position and the transit position) reaches the first restart threshold value (S202). If the continuous non-detection time period at the arrival position and the transit position reaches the first restart threshold value, the control device 40 determines that the bobbin 91 is not present at the arrival position and the transit position, and restarts the operation of the first conveyor 21 (S204).
[0067] If the second conveyor 51 is not in operation, the control device 40 determines whether the continuous non-detection time period at the arrival position and the transit position reaches the second restart threshold value (S203). If the continuous non-detection time period at the arrival position and the transit position reaches the second restart threshold value, the control device 40 determines that the bobbin 91 is not present at the arrival position and the transit position, and restarts the operation of the first conveyor 21 (S204).
[0068] In the present embodiment, the restart threshold value is made different depending on whether the second conveyor 51 is in operation or not, but the restart threshold value having the same value may be used regardless of whether the second conveyor 51 is in operation or not. Another condition for restarting the first conveyor 21 may be added.
[0069] Next, a process for estimating the number of bobbins present in the upstream region will be described.
[0070] The above-described processes make it difficult for the bobbins 91 to overlap, but it may not be possible to completely avoid the overlap of the bobbins 91. Therefore, the control device 40 estimates the number of bobbins present in the upstream region, and performs a process for eliminating the overlap of the bobbins 91 according to such an estimation result. Hereinafter, an estimated value of the number of bobbins present in the upstream region is referred to as an estimated number of bobbins.
[0071] The control device 40 determines whether the bobbin 91 is supplied from the first conveyor 21 to the second conveyor 51 (S301). For example, the control device 40 determines that the bobbin 91 is supplied to the second conveyor 51 from the first conveyor 21 if the stop position sensor 71 detects the end 25a after the supply sensor 72 detects the bobbin 91 when the first conveyor 21 operates. Alternatively, the control device 40 may determine that the bobbin 91 is supplied to the second conveyor 51 from the first conveyor 21 if the arrival sensor 73 detects the bobbin 91 from a state where the arrival sensor 73 does not detect the bobbin 91.
[0072] If determining whether the bobbin 91 is supplied from the first conveyor 21 to the second conveyor 51, the control device 40 increases the estimated number of bobbins by one (S302).
[0073] Next, the control device 40 determines whether a state where the arrival sensor 73 detects the bobbin 91 (ON state) is changed to a state where the arrival sensor 73 does not detect the bobbin 91 (OFF state) (S303). When the bobbin 91 is supplied to the arrival position, the arrival sensor 73 detects the bobbin 91 (ON state). Thereafter, when the bobbin 91 is transported by the second conveyor 51, a state where the arrival sensor 73 does not detect the bobbin 91 (OFF state) is established. Therefore, step S303 is a process of determining whether the bobbin 91 passes over the arrival position.
[0074] If determining that the arrival sensor 73 changes from the ON state to the OFF state, the control device 40 decreases the estimated number of bobbins by one (S304).
[0075] Next, the control device 40 determines whether a time period during which the estimated number of bobbins is two or more reaches an upper limit threshold value (S305). If the estimated number of bobbins is two or more, the two bobbins 91 are present in the upstream region. In such a state, the bobbins 91 overlap or are likely to overlap. Therefore, if determining that the time period during which the estimated number of bobbins is two or more reaches the upper limit threshold value, the control device 40 performs a process to eliminate such a state.
[0076] Firstly, the control device 40 stops the first conveyor 21 (S306). As a result, the new bobbin 91 is not supplied to the upstream region, and thus, the number of bobbins 91 present in the upstream region does not increase. Next, the control device 40 drives the second conveyor 51 in the reverse direction until the arrival sensor and the transit sensor are changed to the OFF state (S307). As a result, the bobbin 91 present in the upstream region drops from the opening 54 to the slope part 13 and is returned. Thus, the situation where the bobbins 91 overlap or where the bobbins 91 are likely to overlap is eliminated.
[0077] Thereafter, the control device 40 changes the estimated number of bobbins to 0 (S308). Next, the control device 40 restarts the operation of the first conveyor 21 and drives the second conveyor 51 in the forward direction (S309). As a result, the operation of supplying the bobbin 91 to the yarn winding machine is restarted.
[0078] Instead of the process of reversing the second conveyor 51, a process of notifying an operator that the two or more bobbins 91 are present in the upstream region may be performed.
[0079] The control device 40 may perform a process of returning the bobbin 91 to the slope part 13 or another location by using another member such as an arm, instead of the process of returning the bobbin 91 to the slope part 13 by using the second belt 52 and the opening 54.
[0080] The transit sensor 74 may be omitted and the arrival sensor 73 only may be used to calculate the estimated number of bobbins.
[0081] As described above, the supply apparatus 1 supplies a yarn winding machine with the bobbin 91 formed by winding a yarn spun by a spinning machine around a core tube. The supply apparatus 1 includes the first conveyor 21, the second conveyor 51, the arrival sensor 73, and the control device 40. The first conveyor 21 separates the plurality of bobbins 91 into individual bobbins 91 and transports each of the bobbins 91. The second conveyor 51 transports the bobbin 91 handed over from the first conveyor 21. The arrival sensor 73 detects the bobbin 91 at a position in the second conveyor 51, the position being an arrival position, where the arrival position is a position at which the bobbin 91 is handed over from the first conveyor 21. The control device 40 determines whether the bobbin 91 is present at the arrival position, based on the continuous detection time period during which the bobbin 91 is continuously detected at the arrival position. One of the conditions for stopping the first conveyor 21 includes determining that the bobbin 91 is present at the arrival position. When the second conveyor 51 is in operation, the control device 40 determines that the bobbin 91 is present at the arrival position when the continuous detection time period reaches the first threshold value. When the second conveyor 51 is stopped, the control device 40 determines that the bobbin 91 is present at the arrival position when the continuous detection time period reaches the second threshold value. The first threshold value is longer than the second threshold value.
[0082] If the second conveyor 51 is in operation, the bobbin 91 is transported by the second conveyor 51, and thus, there is a high possibility that the bobbin 91 is transported from the arrival position as a time passes. Therefore, when the first threshold value is set to a time period longer than the second threshold value, the frequency at which it is determined that the bobbin 91 is present at the arrival position is reduced. Therefore, the first conveyor 21 does not stop frequently, and thus, it is possible to avoid a decrease in efficiency of supplying the bobbin 91.
[0083] The supply apparatus 1 of the present embodiment includes the transit sensor 74 configured to detect the position of the second conveyor 51 at a transit position downstream of the arrival position in the transport direction of the bobbin 91. If the second conveyor 51 is in operation, the control device 40 determines that the condition for stopping the first conveyor 21 is satisfied when determining that the bobbin 91 is present at the arrival position, irrespective of the bobbin 91 being present at the transit position. If the second conveyor 51 is stopped, the control device 40 determines that the condition for stopping the first conveyor 21 is satisfied when determining that the bobbin 91 is present at at least one of the arrival position and the transit position.
[0084] If the second conveyor 51 is in operation, the bobbin 91 at the transit position is immediately transported downstream from the transit position. Therefore, when the detection result of the transit sensor 74 is not considered, it is possible to avoid the first conveyor 21 from stopping at an unnecessary timing.
[0085] The supply apparatus 1 of the present embodiment includes the supply sensor 72 configured to detect the position of the first conveyor 21 present at the supply position at which the bobbin 91 is handed over to the second conveyor 51. One of the conditions for stopping the first conveyor 21 includes the supply sensor 72 detecting the bobbin 91.
[0086] If the bobbin 91 is not present at the supply position, the bobbin 91 is not supplied from the first conveyor 21 to the second conveyor 51 even if the first conveyor 21 continues to operate. Therefore, when the above process is performed, it is possible to avoid the first conveyor 21 from stopping at an unnecessary timing.
[0087] In the supply apparatus 1 of the present embodiment, the condition for restarting the operation of the stopped first conveyor 21 includes the control device 40 determining that the bobbin 91 is not present either at the arrival position or the transit position.
[0088] As a result, it is possible to restart the operation of the first conveyor 21 at a timing when the bobbins 91 do not overlap on the second conveyor 51.
[0089] In the supply apparatus 1 of the present embodiment, the time period during which the bobbin 91 is not detected continuously at the arrival position or the transit position is referred to as the continuous non-detection time period. If the second conveyor 51 is in operation, the condition for restarting the operation of the stopped first conveyor 21 includes the continuous non-detection time period at the arrival position and the transit position reaching the first restart threshold value. If the second conveyor 51 is stopped, the condition for restarting the operation of the stopped first conveyor 21 includes the continuous non-detection time period at the arrival position and the transit position reaching the second restart threshold value. The first restart threshold value is shorter than the second restart threshold value.
[0090] If the second conveyor 51 is in operation, the detected bobbin 91 is immediately transported to the downstream side, and thus, when the continuous non-detection time period is shortened, it is possible to quickly restart the operation of the first conveyor 21.
[0091] In the supply apparatus 1 of the present embodiment, the control device 40 calculates the estimated number of bobbins, which is an estimated value of the number of bobbins 91 present in the upstream region, which is a region from the upstream end to the middle part of the second conveyor 51. The control device 40 stops the first conveyor 21 if the time period during which the estimated number of bobbins is two continuously exceeds the upper limit threshold value.
[0092] As a result, if there is a possibility that the bobbins 91 overlap in the upstream region, it is possible to avoid a situation in which another bobbin 91 is supplied to the second conveyor 51.
[0093] In the supply apparatus 1 of the present embodiment, the control device 40 drives the second conveyor 51 in the reverse direction and discharges the bobbin 91 present in the upstream region if the time period during which the estimated number of bobbins is two continuously exceeds the upper limit threshold value.
[0094] As a result, if the bobbins 91 overlap in the upstream region, it is possible to eliminate the overlap of the bobbins 91 on the apparatus side.
[0095] In the supply apparatus 1 of the present embodiment, the control device 40 increases the estimated number of bobbins by one when the bobbin 91 is supplied from the first conveyor 21 to the second conveyor 51.
[0096] As a result, it is possible to appropriately calculate the number of bobbins 91 present in the upstream region.
[0097] In the supply apparatus 1 of the present embodiment, the control device 40 decreases the estimated number of bobbins by one when the arrival sensor 73 is switched from the state where the bobbin 91 is detected to the state where the bobbin 91 is not detected.
[0098] As a result, it is possible to appropriately calculate the decrease in number of bobbins 91 present in the upstream region.
, Claims:We claim:

1. A supply apparatus (1) for supplying a yarn winding machine with a bobbin (91) formed by winding a yarn spun by a spinning machine around a core tube, comprising:
a first conveyor (21) configured to separate a plurality of the bobbins (91) one by one and individually transport the plurality of bobbins (91);
a second conveyor (51) configured to transport the plurality of bobbins (91) handed over from the first conveyor (21);
an arrival sensor (73) configured to detect each of the plurality of bobbins (91) at a position in the second conveyor (51), the position being an arrival position, where the arrival position is a position at which the plurality of bobbins (91) are handed over from the first conveyor (21); and
a control device (40), wherein
the control device (40) determines whether the bobbin (91) is present at the arrival position, based on a continuous detection time period during which the bobbin (91) is continuously detected at the arrival position,
one of conditions for stopping the first conveyor (21) includes determining that the bobbin (91) is present at the arrival position,
if the second conveyor (51) is in operation, the control device (40) determines that the bobbin (91) is present at the arrival position when the continuous detection time period reaches a first threshold value,
if the second conveyor (51) is stopped, the control device (40) determines that the bobbin (91) is present at the arrival position when the continuous detection time period reaches a second threshold value, and
the first threshold value is longer than the second threshold value.
2. The supply apparatus (1) as claimed in claim 1, comprising:
a transit sensor (74) configured to detect the bobbin (91) at a position in the second conveyor (51), the position being a transit position, where the transit position is downstream of the arrival position in a transport direction of the bobbin (91), wherein
if the second conveyor (51) is in operation, the control device (40) determines that a condition for stopping the first conveyor (21) is satisfied, when determining that the bobbin (91) is present at the arrival position irrespective of whether the bobbin (91) is present at the transit position, and
if the second conveyor (51) is stopped, the control device (40) determines that the condition for stopping the first conveyor (21) is satisfied, when determining that the bobbin (91) is present at at least one of the arrival position and the transit position.

3. The supply apparatus (1) as claimed in claim 1 or 2, comprising:
a supply sensor (72) configured to detect the bobbin (91) at a position in the first conveyor (21), the position being a supply position, where the supply position is a position at which the bobbin (91) is handed over to the second conveyor (51), wherein
one of the conditions for stopping the first conveyor (21) includes the supply sensor (72) detecting the bobbin (91).

4. The supply apparatus (1) as claimed in one of claims 1 to 3, wherein
a condition for restarting an operation of the stopped first conveyor (21) includes the control device (40) determining that the bobbin (91) is not present at either the arrival position or the transit position downstream of the arrival position in a transit direction of the bobbin (91).

5. The supply apparatus (1) as claimed in claim 4, wherein
a time period during which the bobbin (91) is not detected continuously at the arrival position or the transit position is referred to as a continuous non-detection time period,
when the second conveyor (51) is in operation, the condition for restarting the operation of the stopped first conveyor (21) includes the continuous non-detection time periods at the arrival position and the transit position reaching a first restart threshold value,
when the second conveyor (51) is stopped, the condition for restarting the operation of the stopped first conveyor (21) includes the continuous non-detection time periods at the arrival position and the transit position reaching a second restart threshold value, and
the first restart threshold value is shorter than the second restart threshold value.

6. The supply apparatus (1) as claimed in one of claims 1 to 5, wherein
the control device (40) calculates an estimated number of the plurality of bobbins (91) being an estimated value of the number of the plurality of bobbins (91) present in an upstream region being a region from an upstream end to a middle part of the second conveyor (51), and
the control device (40) stops the first conveyor (21) if a time period during which the estimated number of the plurality of bobbins (91) is two continuously exceeds an upper limit threshold value.

7. The supply apparatus (1) as claimed in claim 6, wherein
if the time period during which the estimated number of the plurality of bobbins (91) is two continuously exceeds the upper limit threshold value, the control device (40) drives the second conveyor (51) in a reverse direction to discharge the bobbin (91) present in the upstream region.
8. The supply apparatus (1) as claimed in claim 6 or 7, wherein
the control device (40) increases the estimated number of the plurality of bobbins (91) by one when the bobbin (91) is supplied from the first conveyor (21) to the second conveyor (51).

9. The supply apparatus (1) as claimed in one of claims 6 to 8, wherein
the control device (40) decreases the estimated number of the plurality of bobbins (91) by one when a state where the arrival sensor (73) detects the bobbin (91) is switched to a state where the bobbin (91) is not detected.