Bobbin winding device

Abstract

Ensure proper winding of the lower thread onto the bobbin. [Solution] A bobbin winding device 60 comprises a bobbin 20 having a shaft portion 23 and disc portions 21 and 22 provided at both ends of the shaft portion, a rotating mechanism 61 that imparts rotational motion to the bobbin, and a bobbin supply mechanism 63 having a nozzle 64 that feeds out bobbin thread D from a bobbin thread supply source together with air, wherein the bobbin winding device 60 winds the bobbin thread onto the shaft portion of the bobbin by rotating the bobbin while the bobbin supply mechanism feeds the bobbin thread toward the bobbin, the bobbin shaft portion is provided with a thread-through hole 231 that penetrates in a direction perpendicular to the shaft portion, and the bobbin supply mechanism inserts the bobbin thread through the thread-through hole before winding the bobbin thread.

Description

Technical Field

[0001] The present invention relates to a lower thread winding device for winding a lower thread around a bobbin of a sewing machine.

Background Art

[0002] A conventional lower thread winding device includes a rotating part that applies rotation to a bobbin stored in a bobbin case, and a lower thread supply part that introduces and feeds out the lower thread into a nozzle that discharges air. The tip of the nozzle is brought close to the vicinity of the shaft part of the rotating bobbin to feed out the lower thread and wind the lower thread around the bobbin (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional lower thread winding device, at the start of the winding operation, in order to improve the winding of the lower thread around the shaft part of the rotating bobbin, a friction sheet such as paper or emery is attached to the surface of the shaft part, or a thread loosening device for loosening the fibers of the thread is installed in order to improve the engagement between the lower thread and the friction sheet. However, the friction sheet is easily worn out, and there is a problem that the lower thread cannot be wound after multiple uses. The thread loosening device has a problem that the winding is not stable even when the thread is loosened. Also, when these are used in combination, there is a problem that the tip of the lower thread loosened by the friction sheet becomes entangled, and when dealing with the remaining thread, the remaining thread of the lower thread cannot be removed well from the bobbin.

[0005] An object of the present invention is to wind the lower thread around the bobbin well.

Means for Solving the Problems

[0006] The present invention A bobbin having a shaft portion and disc portions provided at both ends of the shaft portion, The system comprises a rotating mechanism that imparts rotational motion to the bobbin, and a bobbin supply mechanism having a nozzle that feeds out bobbin thread from a bobbin supply source together with air. In a bobbin winding device in which the bobbin is wound around its shaft by the rotation mechanism while the bobbin is rotated by the rotation mechanism, the bobbin winding mechanism feeds the bobbin towards the bobbin by the bobbin supply mechanism, The shaft of the bobbin is provided with a thread-threading hole that penetrates the shaft in a direction perpendicular to the shaft. The aforementioned bobbin thread supply mechanism is characterized by inserting the bobbin thread through the thread hole and then winding the bobbin thread. [Effects of the Invention]

[0007] With the above configuration, the present invention makes it possible to wind the lower thread onto the bobbin smoothly. [Brief explanation of the drawing]

[0008] [Figure 1] This is a front view of a sewing machine and an automatic bobbin thread feeding device, which are embodiments of the invention. [Figure 2] This is a front view of the automatic bobbin thread feeding device. [Figure 3] This is a perspective view of an automatic bobbin thread feeding device. [Figure 4] This is a perspective view of the automatic bobbin thread feeding device, seen from a different direction than Figure 3. [Figure 5] This is a perspective view of a bobbin stored in a bobbin case. [Figure 6] This is a perspective view of a bobbin. [Figure 7] This is a side view of the bobbin. [Figure 8] This is a cross-sectional view perpendicular to the bobbin axis. [Figure 9] This is an objective view of the rotating mechanism. [Figure 10] This is a perspective view of the bobbin thread feeding mechanism. [Figure 11] It is a right side view of the lower thread feeding mechanism. [Figure 12] It is a block diagram showing the control system of the lower thread automatic feeding device. [Figure 13] It is a flowchart showing the feeding control of the lower thread by the lower thread automatic feeding device. [Figure 14] It is a flowchart showing the operation control during the lower thread winding of the lower thread winding device in the lower thread feeding control. [Embodiments for Carrying Out the Invention]

[0009] [Schematic Configuration of the Embodiment] Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a front view of a sewing machine 1 according to an embodiment of the invention and a lower thread automatic feeding device 100 installed together with the sewing machine 1, FIG. 2 is a front view of the lower thread automatic feeding device 100, FIG. 3 is a perspective view of the lower thread automatic feeding device 100, and FIG. 4 is a perspective view of the lower thread automatic feeding device 100 viewed from a direction different from FIG. 3. Hereinafter, the front side of the paper surface of FIGS. 1 and 2 is referred to as "front", the back side of the paper surface of FIGS. 1 and 2 is referred to as "rear", the left side of the paper surface of FIGS. 1 and 2 is referred to as "left", the right side of the paper surface of FIGS. 1 and 2 is referred to as "right", the upper side of the paper surface is referred to as "upper", and the lower side of the paper surface is referred to as "lower". The front-back direction, left-right direction, and up-down direction are perpendicular to each other. In the following description, it is assumed that the sewing machine 1 and the lower thread automatic feeding device 100 are installed on a horizontal plane, and the front-back direction and the left-right direction are horizontal.

[0010] The sewing machine 1 can be of any type as long as it uses a bobbin, and is the object of the lower thread supply of the lower thread automatic feeding device 100. The sewing machine 1 is, for example, a straight stitch sewing machine. The bobbin 2 of the sewing machine 1 is a vertical bobbin and can take in and out the bobbin 20 and the bobbin case 30 from the front side.

[0011] [Lower Thread Automatic Feeding Device] As shown in FIG. 1, the lower thread automatic feeding device 100 includes a standby bobbin holding portion 11, a bobbin conveying device 40, a waste thread removing device 50, a lower thread winding device 60, and a control device 90 (see FIG. 12). When the lower thread automatic supply device 100 detects a reduction in the amount of lower thread wound around the bobbin 20 in the bobbin case 2 on the sewing machine 1 side, the bobbin transfer device 40 holds the bobbin 20 and the bobbin case 30 (hereinafter referred to as "the bobbin 20 etc.") in the bobbin case 2, transports them to the residual thread removal device 50 to remove the lower thread D remaining on the bobbin 20, transports them to the lower thread winding device 60 to wind the lower thread D around the bobbin 20 until it reaches a specified amount, and then transports them to the standby bobbin holding part 11 to set the bobbin 20 etc. Also, while the residual thread of the bobbin 20 taken out from the sewing machine 1 is being removed, the bobbin transfer device 40 sets the bobbin 20 around which the lower thread D has already been wound in the standby bobbin holding part 11 in the bobbin case 2 of the sewing machine 1.

[0012] [Lower thread automatic supply device: Bobbin transfer device] The bobbin transfer device 40 includes a holding arm 41 that can pivot around an axis along the front-rear direction, a pivoting mechanism 42 that imparts a pivoting motion to the holding arm 41 around an axis along the front-rear direction, and a moving mechanism 43 that imparts a moving motion in the front-rear direction to the holding arm 41.

[0013] The holding arm 41 has a gripping mechanism at the tip in the pivoting direction for gripping the forward-facing bobbin 20 etc. located behind it. At the central part of the bobbin case 2 of the sewing machine 1 described above, a bobbin support shaft 2a standing upright forward is provided. This support shaft 2a is passed through the central part of the bobbin 20, and the slide piece provided on the front surface part 32 of the bobbin case 30 is inserted into the constricted locking groove formed at the tip of the support shaft 2a, thereby holding the bobbin 20 etc. with respect to the bobbin case 2. Also, support shafts 112, 512 having the same structure as the bobbin support shaft 2a provided on the bobbin case 2 are provided in each of the standby bobbin holding part 11 and the residual thread removal device 50, and the holding arm 41 can attach and detach the bobbin 20 etc. with respect to each support shaft 112, 512.

[0014] The slide piece of the bobbin case 30 can release the locked state by raising and lowering and pivoting the lever 33 provided on the front surface side of the bobbin case 30 forward. The gripping mechanism at the tip of the holding arm 41 includes a gripping claw that grips the bobbin 20 or the like by rotating the lever 33 in an up-and-down motion. The gripping claw can be operated by an actuator, such as an air cylinder.

[0015] The slewing mechanism 42 includes a slewing motor 421 that serves as the driving source for the slewing of the holding arm 41, a slewing support shaft 422 that supports the base end of the holding arm 41, and a transmission mechanism 423 consisting of multiple belts and pulleys that transmits the torque of the slewing motor 421 to the slewing support shaft 422. The pivot shaft 422 is provided along the front-rear direction and imparts a pivoting motion to the holding arm 41 via a spline mechanism that allows the holding arm 41 to move along the pivot shaft 422.

[0016] At various points along the rotational movement path of the tip of the holding arm 41 as the rotation of the rotation mechanism 42, the support shaft 2a of the bobbin 2 of the sewing machine 1, the support shaft 112 of the standby bobbin holding section 11, the support shaft 512 of the leftover thread removal device 50, and the clutch member 62 of the lower thread winding device 60 are arranged, which serve as installation positions for bobbins 20 and the like. The rotational movement of the holding arm 41 allows the bobbins 20 and the like to be transported to each support shaft.

[0017] The moving mechanism 43 includes a moving motor 431 that serves as the driving source for the forward and backward movement of the holding arm 41, a slide block 432 that can move forward and backward along the pivot axis 422 together with the holding arm 41 while allowing the holding arm 41 to rotate, and a transmission mechanism 433 consisting of multiple belts and pulleys that converts the torque of the moving motor 431 into forward and backward movement and applies it to the slide block 432.

[0018] The slide block 432 has a ring shape through which the pivot shaft 422 passes, and its upper end is connected to a belt stretched in the front-rear direction of the transmission mechanism 433, thereby providing it with front-rear movement. Since the holding arm 41 is movable forward and backward by a spline mechanism, it is given forward and backward movement through the slide block 432. Therefore, the holding arm 41 can perform both forward and backward movement and pivoting movement. As a result, the holding arm 41 transports the bobbin 20, etc., to the respective positions of the support shaft 2a of the bobbin 2 of the sewing machine 1, the support shaft 112 of the standby bobbin holding section 11, the support shaft 512 of the leftover thread removal device 50, and the clutch member 62 of the lower thread winding device 60. By moving backward, the bobbin 20, etc., is attached to each support shaft, etc., and by moving forward, the bobbin 20, etc., can be removed from each support shaft, etc.

[0019] [Automatic bobbin thread feeder: Standby bobbin holder] The standby bobbin holder 11 is positioned between the bobbin case 2 of the sewing machine 1 and the leftover thread removal device 50 in the pivoting movement path of the tip of the holding arm 41. The standby bobbin holder 11 includes a base 111 on which the bobbin 20 etc. is placed, and a support shaft 112 that is inserted into the center of the bobbin 20 etc. to hold it in place. The base 111 has a roughly circular front surface, and a support shaft 112 is provided at its center, extending forward. The base 111 is also provided with a rotation stopper 113 for the bobbin case 30. As a result, the bobbin 20 and the like can be attached to and detached from the standby bobbin holding unit 11 from the front by the holding arm 41.

[0020] [Bobbin thread automatic supply device: Remaining thread removal device] The leftover thread removal device 50 is located on the lower side of the entire rotational movement path of the tip of the holding arm 41. The leftover yarn removal device 50 includes a bobbin arrangement section 51, a drawing mechanism 52 for drawing out leftover lower yarn D from bobbins 20 etc. arranged in the bobbin arrangement section 51, and a discharge mechanism 53 for sucking up the drawn-out lower yarn D and sending it to a collection section (not shown).

[0021] The bobbin arrangement section 51 includes a base 511 on which the bobbins 20 and the like are placed, and a support shaft 512 that is inserted into the center of the bobbins 20 and the like to hold them in place. The base 511 has a flat front side, and a support shaft 512 is provided in its center, extending forward. As a result, the bobbin 20 and other components can be attached to and detached from the bobbin arrangement section 51 from the front by the holding arm 41.

[0022] The support shaft 512 has the same structure as the support shaft 2a of the aforementioned boiler 2 and rotatably supports the bobbin 20. On the other hand, the base 511 is provided with a rotation stopper for the bobbin case 30 (not shown), and the bobbin case 30 is held in place so as not to rotate.

[0023] The drawer mechanism 52 is located below the bobbin arrangement section 51 and includes a pair of drawer rollers 521 that grip the lower thread D hanging from the bobbin 20 with the nip section and feed it downward, and a drawer motor 522 (see Figure 12), which is a drive source for the drawer rollers 521 (not shown). A pair of pull-out rollers 521 rotate in opposite directions while being pressed together by a pull-out motor 522, feeding the lower thread D at the pressed-together section downwards.

[0024] The discharge mechanism 53 includes a discharge nozzle 531 that sucks up the lower yarn D fed out by a pair of pull-out rollers 521, and an ejector 532 that generates suction pressure in the discharge nozzle 531. The discharge nozzle 531 has a suction port at one end that is positioned upwards, directly below the nip portion of the pair of pull-out rollers 521. The ejector 532 generates an airflow in a predetermined passage, which is connected to the lower end of the discharge nozzle 531. As a result, negative pressure is created inside the discharge nozzle 531, allowing the lower thread D to be sucked out from the suction port. A recovery section consisting of a net or recovery box (not shown) is installed downstream of the flow path of the ejector 532, and the remaining yarn of the lower thread D can be fed into this recovery section.

[0025] [Bobbins and bobbin cases] Here, we will describe the bobbin 20 and the bobbin case 30. Figure 5 is a perspective view of the bobbin 20 stored in the bobbin case 30, Figure 6 is a perspective view of the bobbin 20, Figure 7 is a side view of the bobbin 20, and Figure 8 is a cross-sectional view perpendicular to the axis of the bobbin 20.

[0026] The bobbin 20 has a shaft portion 23 and a first disc portion 21 and a second disc portion 22 provided at both ends of the shaft portion 23. The first disc portion 21, the second disc portion 22, and the shaft portion 23 are concentrically and integrally connected, and a central hole 24 is formed in the center of these, passing through the entire structure along the center line. The bobbin 20 is held in each position with the aforementioned support shafts 2a, 112, and 512 inserted into this central hole 24.

[0027] The first disc portion 21 and the second disc portion 22 are discs of the same diameter. The first disc portion 21 has two circular positioning holes 211 formed at both ends in the perpendicular direction, penetrating the disc surface perpendicularly. These positioning holes 211 engage with two engaging protrusions 624 of the clutch member 62 of the bobbin winding device 60 (described later), and rotational force is input to wind the bobbin D onto the bobbin 20.

[0028] The shaft portion 23 has a larger diameter on the side of the first disc portion 21 compared to the side of the second disc portion 22. Two thread-through holes 231 are formed through the larger diameter portion of the shaft portion 23 on both sides in the diametrical direction, with the central hole 24 in between, and parallel to each other in directions perpendicular to the central hole 24. As shown in Figure 8, each thread-through hole 231 is also perpendicular to the diametrical direction in which the two positioning holes 211 of the first disc portion 21 are aligned.

[0029] Furthermore, each thread hole 231 has an enlarged diameter at both open ends and a reduced diameter in the middle. The two thread holes 231 in the shaft portion 23 are used to insert the tip of the bobbin thread D into one of them by blowing it from a nozzle 64 (described later) of the bobbin winding device 60, and then winding the bobbin thread D onto the shaft portion 23 by applying rotation to the bobbin 20 in that state.

[0030] The bobbin case 30 includes a cylindrical portion 31 that can house the bobbin 20 inside, a front portion 32 that closes one end of the cylindrical portion 31, a slide piece (not shown) that is inserted into a locking groove (not shown) of the support shafts 2a, 112, 512 within a through hole formed through the center of the front portion 32 through which the tips of the support shafts 2a, 112, 512 pass, a lever 33 that is provided on the front portion 32 so as to be able to pivot forward and backward to release the locking state of the slide piece, and a corner portion 34 that extends radially outward from the front portion 32.

[0031] The cylindrical portion 31 has an inner diameter that is slightly larger than the outer diameters of the first and second disc portions 21 and 22 of the bobbin 20, allowing the entire bobbin 20 to be stored inside from the rear. A notch 311 is formed at a predetermined position in the circumferential direction of the cylindrical portion 31, extending from the rear edge to the vicinity of the front end. Furthermore, the cylindrical portion 31 also has a feed hole (not shown) for feeding the lower thread D from the inner bobbin 20 to the outside of the bobbin case 30. A thread tension spring is provided on the outer surface of the cylindrical portion 31, near the feed hole for the lower thread D, to apply tension to the fed-out lower thread D.

[0032] [Bottom thread winding device] As shown in Figures 2 to 4, the bobbin winding device 60 includes a rotating mechanism 61 that holds the bobbin 20 and the like and applies rotational motion, a bobbin supply mechanism 63 that can position a nozzle 64 that feeds out the bobbin thread D together with air to a bobbin supply position where the tip of the nozzle 64 is closest to the shaft portion 23 of the bobbin 20, and a bobbin feeding mechanism 65 that pulls out the bobbin thread D, which is fed out from a thread spool (not shown) located on the thread stand 12 (see Figure 1) that serves as the bobbin supply source, from the thread spool and supplies it to the bobbin supply mechanism 63. Furthermore, the lower thread winding device 60 assumes that the bobbin case 30 containing the bobbin 20 is held by the holding arm 41 of the bobbin transport device 40 while the lower thread D is wound onto the bobbin 20.

[0033] Figure 9 is a perspective view of the rotating mechanism 61. In Figure 9, the bobbin case 30 is omitted from the illustration in order to explain the structure of the clutch member 62, which will be described later, and the bobbin 20 is shown in a position shifted forward. As shown in Figures 4 and 9, the rotating mechanism 61 includes a rotary motor 611 (see Figure 12) which serves as a rotational drive source for winding the bobbin thread D onto the bobbin 20, a clutch member 62 which can be fitted to the bobbin 20 to transmit torque, a cylindrical support 612 which supports the clutch member 62, and a belt mechanism (not shown) which transmits torque from the rotary motor 611 to the support 612.

[0034] The rotary motor 611 is a motor capable of arbitrarily controlling rotational movements such as shaft angle, rotational speed, and rotational velocity, such as a servo motor or a stepping motor. The rotary motor 611 has its output shafts arranged parallel to each other in the front-to-back direction.

[0035] The support body 612 is a substantially cylindrical rotating body that concentrically supports the rotation axis 621 of the clutch member 62. The substantially cylindrical support 612 has grooves on its inner circumferential surface that slidably support a radially outward projection provided on the outer circumference of the rotating shaft 621 along the direction of the rotational centerline, thereby supporting the rotating shaft 621 so that it can move back and forth along the direction of the rotational centerline (front and rear direction) and rotating integrally with the rotating shaft 621.

[0036] Furthermore, the support 612 incorporates a compression spring that presses the clutch member 62 forward (towards the bobbin 20). This compression spring maintains the clutch member 62 in the furthest forward position shown in Figure 9, and when the clutch member 62 is pushed backward from the furthest forward position, it provides a return force to the clutch member 62 to move forward.

[0037] The belt mechanism includes a driving pulley provided on the output shaft of the rotary motor 611, a driven pulley concentrically and integrally connected to the support 612, and a timing belt stretched across the driving and driven pulleys simultaneously. The belt mechanism transmits torque to the clutch member 62 via the support 612 when driven by the rotary motor 611.

[0038] The clutch member 62 includes a rotating shaft 621, a circular base plate 622 to which the front end of the rotating shaft 621 is fixedly connected at the center of its rear surface, a central projection 623 provided at the center of the front surface of the base plate 622, and a pair of engaging projections 624 provided at both ends in the diametrical direction on the front surface of the base plate 622, which protrude forward. The central projection 623 is inserted into the central hole 24 of the bobbin 20, and the pair of engaging projections 624 are provided to be fitted into a pair of positioning holes 211 of the bobbin 20.

[0039] When the control device 90 transports the bobbin 20, etc., to a predetermined transport target position relative to the lower thread winding device 60 using the holding arm 41 of the bobbin transport device 40, it positions the bobbin 20, etc., at a position where the rotation axis 621 and central projection 623 of the clutch member 62 and the central hole 24 of the bobbin 20 are concentric, and the rear surface of the first disc portion 21 of the bobbin 20 is slightly in front of the tip of the central projection 623 of the clutch member 62. Then, the control device 90 moves the bobbin 20 held by the holding arm 41 backward using the moving mechanism 43. As a result, the central projection 623 of the clutch member 62 is inserted into the central hole 24 of the bobbin 20. On the other hand, since the orientation of the bobbin 20 held by the holding arm 41 around its central axis is not fixed, there is a high possibility that the positions of the pair of engaging projections 624 and the pair of positioning holes 211 around the central axis will not coincide, and the tips of the pair of engaging projections 624 will come into contact with the rear surface of the first disc portion 21. In this state, the control device 90 drives the rotary motor 611 to rotate the clutch member 62 half a turn at a low speed, and during this rotation, the positions of the pair of engaging projections 624 around the central axis will coincide with the pair of positioning holes 211, and the bobbin 20 will fit into the clutch member 62 and become capable of linked rotation. Here, the series of controls performed by the control device 90 to engage the clutch member 62 and the bobbin 20 will be referred to as "engagement control."

[0040] Since the rotary motor 611 is a motor whose axis angle can be arbitrarily controlled, the control device 90 can control the orientation of the bobbin 20 around its central axis via the clutch member 62 after the fitting control. Specifically, the control device 90 controls the rotary motor 611 and waits so that the bobbin 20 is in a predetermined orientation (receiving position) for receiving the bobbin thread D from the nozzle 64 of the bobbin thread supply mechanism 63. The receiving position is a position in which either of the thread holes 231 of the bobbin 20 can be positioned to face the tip of the nozzle 64 at the lower thread supply position, as described later. For example, as shown in Figure 5, the two thread holes 231 of the bobbin 20 are tilted slightly to the upper right with respect to the vertical direction, with the upper opening ends of each thread hole 231 aligned horizontally, and the lower opening ends of each thread hole 231 also aligned horizontally. The two thread holes 231 are formed such that when the bobbin 20 is rotated 180°, one and the other are swapped while maintaining the same position and orientation. Therefore, the feeding positions are two positions: one where one opening end of one thread hole 231 on the bobbin 20 is directly facing the tip of the nozzle 64 at an angle around the central axis, and the other where, after a 180° rotation, one opening end of the other thread hole 231 is directly facing the tip of the nozzle 64 at an angle around the central axis.

[0041] As shown in Figures 3 and 4, the bobbin thread supply mechanism 63 includes a nozzle 64, a rotating motor 631 which is the driving source for the rotational movement of the nozzle 64, a holding block 632 which holds the nozzle 64, and a belt mechanism 633 which transmits torque from the rotating motor 631 to rotate the holding block 632.

[0042] The nozzle 64 is a tubular body that feeds the bobbin thread D from the inside using air. The nozzle 64 is supported by a holding block 632 so as to be rotatable around an axis along the front-rear direction, and can be switched between a bobbin thread supply position (shown as a dashed line in Figures 3 and 4) where the tip is directly facing the lower opening end of the thread thread hole 231 located to the left of the bobbin 20 in the receiving position, and a retracted position (shown as a solid line in Figures 3 and 4) where the tip is separated from the bobbin 20 to the lower left.

[0043] As shown in Figure 5, the nozzle 64 is formed such that, at the lower thread supply position, its tip is oriented parallel to the longitudinal direction of the thread hole 231 of the bobbin 20 at the receiving position. Therefore, since the direction of air discharge coincides with the thread hole 231, the ejected lower thread D can be fed into the thread hole 231 effectively and smoothly.

[0044] The rotating motor 631 is positioned with its output shaft facing forward. The belt mechanism 633 includes a driving pulley provided on the output shaft of the rotating motor 631, a driven pulley positioned next to the rotating motor 631, and a timing belt stretched across the driving pulley and the driven pulley simultaneously.

[0045] The retaining block 632 is fixedly supported by the driven pulley of the belt mechanism 633 and rotates together with the driven pulley. The holding block 632 has an airflow channel and a thread supply channel that merges with it. The upstream side of the air supply passage is connected to an air supply source such as a blower, and the downstream side is connected to the base of the nozzle 64. The upstream side of the yarn feeding channel is connected to a yarn feeding hose 656, which receives the lower yarn D from the lower yarn feeding mechanism 65.

[0046] Figure 10 is a perspective view of the bobbin thread feeding mechanism 65, and Figure 11 is a right side view. The bobbin thread feeding mechanism 65 includes three thread tension controls 651, 653, and 654, a bobbin thread feeding amount detection device 652, an intermittent feeding unit 66, a thread guide 655 positioned directly in front of the intermittent feeding unit 66, and a thread feeding hose 656 that forms a conduit for sending the bobbin thread D from the intermittent feeding unit 66 to the holding block 632.

[0047] The three thread tensioners 651, 653, and 654 are all mechanisms that sandwich the lower thread D between a pair of thread tension discs and apply tension to the lower thread D on the downstream side. The lower thread D is passed through the thread tensioners 651, 653, and 654 in that order from the upstream side, and passes through the feed amount detection device 652 between thread tensioner 651 and thread tensioner 653.

[0048] The feed amount detection device 652 consists of a measuring pulley that rotates when the bobbin thread D is passed and sent downstream, and an encoder that rotates together with the pulley and detects the amount of bobbin thread D fed out from its rotation angle. This feed amount detection device 652 is used to detect the amount of winding when winding the bobbin thread onto the bobbin 20.

[0049] The intermittent feeding unit 66 is located between the thread guide 655 and the inlet of the thread supply hose 656. The intermittent feeding unit 66 includes a feeding arm 662 as a bobbin thread feeding member that feeds the bobbin thread D from the upstream side by rotation, a feeding solenoid 661 as a drive source that provides rotational movement around an axis along the vertical direction to the base end of the feeding arm 662, and a gripping air cylinder 663 as a gripping unit that extends a plunger and grips the bobbin thread D together with the opposing plate 664.

[0050] The clamping air cylinder 663 and the opposing plate 664 are positioned just in front of the inlet of the yarn delivery hose 656, and the clamping air cylinder 663 can extend its plunger 663a forward. In front of the plunger 663a, the flat surface of the opposing plate 664 is positioned opposite. When the plunger 663a extends forward, the lower thread D, which runs from the thread guide 655 to the entrance of the thread supply hose 656, is clamped between the plunger 663a and the opposing plate 664, preventing the lower thread D from moving downstream of the clamping position.

[0051] The feeding arm 662 is positioned upstream of the clamping air cylinder 663 in the path of the lower thread D from the thread guide 655 to the entrance of the thread feed hose 656. The feeding arm 662 has its base end supported by the output shaft of the feeding solenoid 661, and its rotating end has a through hole through which the lower thread D is inserted. The feed arm 662 is rotated by the feed solenoid 661 from the standby position to the draw-out position, where the rotating end moves to the rear. This allows the bobbin thread D from the thread guide 655 to the entrance of the thread feed hose 656 to change from a state where it runs almost straight to a state where it is sharply bent backward in the middle. When the bobbin thread D transitions from a straight state between the thread guide 655 and the entrance of the thread supply hose 656 to a state where it bends sharply backward, the path length of the bobbin thread D increases.

[0052] Therefore, with the clamping air cylinder 663 clamping the lower thread D downstream of the feeding arm 662, the feeding arm 662 rotates backward, allowing the increased path length to be drawn from the thread supply source side. After the thread is pulled out, the feeding arm 662 returns to its standby position, allowing the bobbin thread D to have some slack due to the amount of thread pulled out. By retracting the plunger 663a of the clamping air cylinder 663, the pulled-out bobbin thread D can be supplied to the downstream side in a low-tension state.

[0053] [Control system for automatic bobbin thread feeding device] Figure 12 is a block diagram showing the control system of the automatic bobbin thread feeding device 100. As shown in the figure, the automatic bobbin thread feeding device 100 is equipped with a control device 90 that controls the operation of each component. Furthermore, the control device 90 is connected to the following via drive circuits (not shown): the swivel motor 421 of the swivel mechanism 42 and the move motor 431 of the move mechanism 43 of the bobbin transport device 40, the pull-out motor 522 of the pull-out mechanism 52 and the ejector 532 of the discharge mechanism 53 of the leftover yarn removal device 50, the rotary motor 611 of the rotation mechanism 61 of the lower yarn winding device 60 and the rotary motor 631 of the lower yarn supply mechanism 63, and the pull-out solenoid 661 of the lower yarn feed mechanism 65. Furthermore, the control device 90 is connected to the clamping air cylinder 663 of the bobbin thread feeding mechanism 65 via a solenoid valve and drive circuit (not shown) that control its operation. Furthermore, the control device 90 is connected to a thread feed amount detection device 652 of the bobbin thread feed mechanism 65 via an interface (not shown).

[0054] The control device 90 includes a CPU 91, ROM 92, RAM 93, and data memory 94, and performs various operation controls as described later. ROM92 stores the basic system programs. Furthermore, the data memory 94 stores various setting data and control programs. The data memory 94 can be any non-volatile storage device such as EEPROM (registered trademark), flash memory, EPROM, or HDD. The CPU 91 executes various programs stored in the ROM 92 and data memory 94. RAM 93 is the memory that serves as the CPU 91's workspace.

[0055] Furthermore, the control device 90 is connected to a communication unit 95 that communicates with a control device (not shown) of the sewing machine 1, and communicates information such as when the amount of lower thread D in the bobbin 20 on the sewing machine 1 decreases and the status of the sewing operation.

[0056] [Lower thread supply control] The supply control of the lower thread D by the automatic lower thread supply device 100, executed by the CPU 91 of the control device 90, will be explained based on the flowchart in Figure 13. When the control device of the sewing machine 1 notifies the CPU 91 that the remaining amount of bobbin thread in the bobbin 20 currently in use has reached a predetermined reduced state, the CPU 91 starts controlling the supply of the bobbin thread D.

[0057] First, the CPU 91 checks with the control device of the sewing machine 1 to see whether or not sewing is in progress (operation) (step S1). If sewing machine 1 is in operation, the check is repeated until the operation is completed.

[0058] Furthermore, if the sewing machine 1 is not in operation, the CPU 91 moves the holding arm 41 to the position of the bobbin 2 of the sewing machine 1 and removes the bobbin 20 and other items from inside (step S3).

[0059] Next, the CPU 91 transports the bobbin 20 and other components to the bobbin placement section 51 of the leftover yarn removal device 50 and places them there. Then, it drives the pull-out motor 522 and operates the ejector 532 to remove and recover the leftover yarn from the bobbin 20 (step S5).

[0060] While removing excess thread from the bobbin 20, the CPU 91 moves the holding arm 41 to the standby bobbin holding unit 11 to pick up the bobbin 20 with the lower thread D wound on it, transport it to the sewing machine 1, and set it in the bobbin case 2 (step S7). The CPU 91 notifies the control device of the sewing machine 1 that the replenishment of the bobbin 20 with the lower thread D wound on it is complete (sewing can be resumed).

[0061] Next, the CPU 91 moves the holding arm 41 back to the leftover thread removal device 50, picks up the bobbin 20 etc. from which the leftover thread has been removed, and transports it to the lower thread winding device 60. Furthermore, in the lower thread winding device 60, the bobbin 20 etc. is set on the clutch member 62 and the winding of the lower thread D is performed (step S9).

[0062] Then, once the winding of the lower thread D onto the bobbin 20 is complete, the CPU 91 uses the holding arm 41 to pick up the bobbin 20, etc., and transports it to the standby bobbin holding unit 11, and attaches the bobbin 20, etc., to its support shaft 112, thus completing the series of operations (step S11).

[0063] A more detailed explanation of the operation control of the bobbin winding device 60 during bobbin winding in the above-mentioned bobbin thread supply control will be given based on the flowchart in Figure 14. When the CPU 91 transports the bobbin 20, etc., from the leftover thread removal device 50 to the bobbin winding device 60 after the removal of the lower thread D has been completed, the CPU 91 uses the aforementioned fitting control to fit the pair of engaging protrusions 624 of the clutch member 62 into the pair of positioning holes 211 of the bobbin 20 (step S31).

[0064] Then, the CPU 91 adjusts the angle of the bobbin 20 around its centerline via the clutch member 62 so that one of the bobbin 20's thread holes 231 is in a feeding position that can directly face the tip of the nozzle 64 of the lower thread winding device 60 (step S33).

[0065] Next, the CPU 91 controls the rotary motor 631 to rotate the nozzle 64 to a lower thread supply position where the tip of the nozzle 64 faces one of the thread holes 231 of the bobbin 20 (step S35).

[0066] Next, as shown in Figure 11, the CPU 91 activates the clamping air cylinder 663 of the bobbin thread feeding mechanism 65 to clamp the bobbin thread D between the plunger 663a and the opposing plate 664. Furthermore, the feed solenoid 661 is controlled to rotate the feed arm 662 backward on the upstream side of the clamping air cylinder 663, causing the first feed of the lower thread D from the thread supply source side (step S37), and the discharge of air from the nozzle 64 is started (step S39).

[0067] Next, the CPU 91 retracts the plunger 663a of the clamping air cylinder 663 to release the bobbin thread D, and controls the feed solenoid 661 to rotate the feed arm 662 forward at a slower speed than in the case of the second feed described later. As a result, the bobbin thread D is supplied from the tip of the nozzle 64 into the thread hole 231 of the bobbin 20 at a slow speed (step S41).

[0068] Furthermore, the CPU 91 operates the clamping air cylinder 663 to clamp the bobbin thread D, and the feed solenoid 661 rotates the feed arm 662 backward to feed out the bobbin thread D a second time (step S43). Next, the feeding arm 662 is rotated forward to return to its original position, and once the bobbin thread D has become slack and has some slack, the clamping air cylinder 663 is activated to release the bobbin thread D (step S45). As a result, the slack in the bobbin thread D is supplied to the threading hole 231 of the bobbin 20, and the bobbin thread D is inserted with a sufficient length protruding from the opening end of the threading hole 231 opposite to the nozzle 64 (bobbin thread insertion process).

[0069] In this state, the CPU 91 starts rotating the bobbin 20 with the rotary motor 611 (winding process: step S47). At this point, the discharge of air from the nozzle 64 may be stopped. The tip of the lower thread D protrudes outward from the thread hole 231 of the bobbin 20 with sufficient length, so that when the bobbin 20 starts to rotate, the lower thread D does not come out of the thread hole 231 and cannot be wound onto the shaft 23, and the lower thread D is wound onto the bobbin 20 smoothly.

[0070] At a certain time after the bobbin 20 starts rotating, the nozzle 64 rotates to a retracted position, and its tip separates from the bobbin 20. In this state, a thread handling member (not shown) of the lower thread winding device 60 handles the thread between the nozzle 64 and the bobbin 20, guiding the lower thread D in the correct direction. Furthermore, the amount of winding of the lower thread D is determined from the amount of pulley rotation detected by the encoder of the feed amount detection device 652 relative to the bobbin 20, to determine whether the winding amount has reached the target amount (step S49).

[0071] Then, when it is detected that a predetermined amount of winding has been completed, the rotation of the bobbin 20 is stopped (step S51), and the lower thread D is cut by the thread cutting blade provided in the thread handling mechanism mentioned above, and the lower thread winding control ends. After the lower thread winding control is completed, the bobbin 20 is sent to the standby bobbin holding unit 11, as shown in step S11 of Figure 13.

[0072] [Technical Effects of Embodiments of the Invention] The automatic bobbin thread supply device 100 works by having the bobbin thread supply mechanism 63 insert the bobbin thread D through the thread thread hole 231 that penetrates the shaft portion 23 of the bobbin 20 using a nozzle 64 along with air, and then the rotating mechanism 61 winds the bobbin thread D. As a result, the bobbin thread D is wound well around the shaft portion 23, and stable winding of the bobbin thread D becomes possible. Furthermore, unlike conventional methods, it is no longer necessary to attach a friction sheet to the shaft portion 23 of the bobbin 20 or to loosen the tip of the lower thread D, making it possible to quickly and efficiently wind the lower thread D onto the bobbin 20. Furthermore, a bobbin thread unraveling device for unraveling the tip of the bobbin thread D becomes unnecessary, making it possible to reduce the device cost and miniaturize the automatic bobbin thread supply device 100.

[0073] Furthermore, the bobbin winding device 60 of the automatic bobbin supply device 100 has a rotating mechanism 61 that imparts rotational motion to the bobbin 20, which allows the bobbin 20 to be positioned at a rotational angle such that the thread hole 231 of the bobbin 20 faces directly toward the tip of the nozzle 64 at the bobbin supply position. This allows the lower thread D to be inserted through the thread hole 231 of the bobbin 20 before winding the lower thread, enabling smooth and stable winding of the lower thread D onto the bobbin 20.

[0074] Furthermore, in the bobbin winding device 60, the threading hole 231 of the bobbin 20 and the tip of the nozzle 64 at the bobbin supply position are facing each other, and the threading hole 231 and the tip of the nozzle 64 are facing the same direction. Therefore, when the lower thread D is fed out from the tip of the nozzle 64 along with air, it can be effectively fed into the thread-threading hole 231 of the bobbin 20, and the lower thread D can be wound onto the bobbin 20 more smoothly and stably.

[0075] Furthermore, the rotation mechanism 61 of the bobbin winding device 60 includes a clutch member 62 that fits onto the bobbin 20 and transmits rotational motion to the bobbin 20, and a rotary motor 611 that acts as a drive unit capable of controlling the rotation angle of the clutch member 62. Then, the rotary motor 611 rotates the clutch member 62, making it possible to position the bobbin 20 at a rotation angle such that the thread hole 231 of the bobbin 20 faces directly towards the tip of the nozzle 64 that is closest to the bobbin 20. Therefore, the lower thread D can be stably fed into the thread-threading hole 231 of the bobbin 20, and the lower thread D can be wound onto the bobbin 20 more smoothly and stably.

[0076] Furthermore, the disc portion 21 of the bobbin 20 has a positioning hole 211 that penetrates perpendicularly through the disc surface, the clutch member 62 has an engaging projection 624 that engages with the positioning hole 211, and the rotating mechanism 61 has a pressing spring that presses the clutch member 62 toward the bobbin 20. Thus, the clutch member 62 and the bobbin 20 can be fitted together when the positioning hole 211 and the engaging projection 624 are at a constant relative rotation angle. Therefore, even if the orientation of the bobbin 20 set in the lower thread winding device 60 is not constant, rotating the clutch member 62 allows the positioning hole 211 and the engaging projection 624 to engage, making it possible to adjust the orientation of the bobbin 20 integrally with the clutch member 62. Therefore, even without a detection device to detect the orientation of the bobbin 20, the rotating mechanism 61 can hold the bobbin 20 in a predetermined orientation, the orientation of the bobbin 20 can be adjusted arbitrarily, and the bobbin 20 can be positioned at a rotation angle in which the thread-threading hole 231 of the bobbin 20 faces directly toward the tip of the nozzle 64 at the lower thread supply position. Consequently, it becomes possible to easily automate the process of winding the lower thread D onto the bobbin 20.

[0077] Furthermore, under the control of the control device 90, the lower thread winding device 60 prevents the lower thread D from moving toward the nozzle 64 using the clamping air cylinder 663, while the feeding arm 662 feeds out the lower thread D, and inserts the lower thread D into the thread hole 231 of the bobbin 20 with slack in the lower thread D. Therefore, since the lower thread D can be inserted through the thread hole 231 with sufficient length, winding can be performed, resulting in better and more stable winding of the lower thread D onto the bobbin 20.

[0078] Furthermore, since the bobbin 20 is provided with a thread-threading hole 231 that penetrates the shaft portion 23 in a direction perpendicular to the shaft portion 23, it is possible to wind the lower thread D onto the bobbin 20 more smoothly and stably without winding a friction sheet around the shaft portion 23 or unraveling the end of the lower thread D. Therefore, the winding of the lower thread D onto the bobbin 20 can be performed easily and smoothly. In addition, since a friction sheet is not used, it is possible to avoid the lower thread D becoming entangled in the shaft portion and becoming difficult to remove. Furthermore, since there is no need to loosen the tip of the lower thread D, it becomes possible to eliminate the need to install a mechanism for loosening the tip of the lower thread D on the lower thread winding device side that winds the lower thread D onto the bobbin 20.

[0079] The shaft portion 23 of the bobbin 20 is provided with two thread holes 231, and these two thread holes 231 are formed so that when the bobbin 20 is rotated 180°, one of them remains in the same position and orientation while being swapped with the other. Therefore, alignment can be achieved with a rotation of less than 180° to align the thread holes 231 of the bobbin 20 with the tip of the nozzle 64, thereby speeding up the work.

[0080] Furthermore, the bobbin winding device 60, under the control of the control device 90, performs a bobbin winding method that includes a bobbin thread insertion step of inserting the bobbin thread D into the thread hole 231 provided in the bobbin 20, and a winding step of applying a rotational motion to the bobbin 20 after the bobbin thread D has been inserted into the thread hole 231. As a result, the bobbin thread D can be wound onto the bobbin 20 smoothly and stably.

[0081] [others] Embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above. For example, a component integrally formed from a single member in an embodiment may be replaced with a component divided into multiple members that are connected or fixed to each other. Also, a component formed by connecting multiple members may be replaced with a component integrally formed from a single member. Furthermore, details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention.

[0082] For example, the bobbin winding device 60 starts rotating the bobbin 20 after unwinding the thread twice from the thread supply source, but the number of thread unwinding cycles may be one or three or more. [Explanation of Symbols]

[0083] 1 Sewing machine 2 kettles 2a spindle 11 Standby bobbin holder 112 Spindle 20 bobbins 21 First disc section 211 Positioning holes 22 Second disc section 23 Shaft section 231 Threading holes 24 Center hole 30 Bobbin Cases 33 Lever 40 Bobbin transport device 41 Holding arm 42 Swivel mechanism 421 Swivel motor 43 Moving mechanism 431 Mobile Motor 50 Remaining thread removal device 60. Bobbin winding device 61 Rotation mechanism 611 Rotary Motor 62 Clutch component 621 Rotation axis 622 Base Plate 623 Central protrusion 624 Engagement protrusion 63 Lower thread supply mechanism 631 Rotary Motor 632 Holding block 64 nozzles 65. Bobbin thread feeding mechanism 655 Thread Guide 656 Yarn delivery hose 66 Intermittent dispensing section 661 Retractable solenoid 662 Thread feed arm (lower thread feed component) 663 Clamping air cylinder (gripping part) 664 Opposing plate 90 Control device 91 CPU 100 Automatic bobbin thread feeder D Bobbin thread

Claims

1. A bobbin having a shaft portion and disc portions provided at both ends of the shaft portion, The system comprises a rotating mechanism that imparts rotational motion to the bobbin, and a bobbin supply mechanism having a nozzle that feeds out bobbin thread from a bobbin supply source together with air. In a bobbin winding device in which the bobbin is wound around its shaft by the rotation mechanism while the bobbin is rotated by the rotation mechanism, the bobbin winding mechanism feeds the bobbin towards the bobbin by the bobbin supply mechanism, The shaft of the bobbin is provided with a thread-threading hole that penetrates the shaft in a direction perpendicular to the shaft. The bobbin thread supply mechanism is characterized by inserting the bobbin thread through the thread hole and then winding the bobbin thread.

2. The bobbin winding device according to claim 1, characterized in that the threading hole of the bobbin and the tip of the nozzle are facing each other and the threading hole and the tip of the nozzle are facing the same direction.

3. The rotation mechanism includes a clutch member that fits onto the bobbin and transmits rotational motion to the bobbin, and a drive unit capable of controlling the rotational motion of the clutch member. The lower thread winding device according to claim 2, characterized in that the drive unit rotates the clutch member to position the bobbin at a rotation angle such that the thread hole of the bobbin faces the tip of the nozzle that is closest to the bobbin.

4. The disc portion of the bobbin has a positioning hole formed that penetrates the disc surface perpendicularly. The clutch member has an engaging projection that engages with the positioning hole, The lower thread winding device according to claim 3, characterized in that the rotation mechanism has a pressing spring that presses the clutch member toward the bobbin, and the rotational motion is transmitted to the bobbin by the engagement of the positioning hole and the engaging projection.

5. In the lower thread supply path from the lower thread supply source to the nozzle, a gripping portion prevents the movement of the lower thread toward the nozzle, It has a lower thread feeding member that feeds out the lower thread on the lower thread supply source side of the gripping portion, The bobbin winding device according to any one of claims 1 to 4, characterized in that the movement of the bobbin thread toward the nozzle is prevented by the gripping portion, the bobbin thread is fed out by the bobbin threading member, and the bobbin thread is inserted into the threading hole of the bobbin while slack is given to the bobbin thread.

6. The shaft portion of the bobbin is provided with two thread-threading holes. The bobbin winding device according to any one of claims 1 to 4, characterized in that the two thread holes are formed such that when the bobbin is rotated 180°, one and the other are swapped while maintaining the same position and orientation.

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