Thread take-up device for a sewing machine

Abstract

The present invention provides a thread winding device for a sewing machine, which can wind a bobbin without accompanying the operation of the sewing machine. The device includes a winding shaft (20) that holds the bobbin, a winding motor (11) that rotates the winding shaft, a rotation number detection unit (12) of the winding motor, a rotating body (30) that has a stop recess (31) for stopping the rotation of the winding shaft, a bobbin rod (40) that has a rod portion and a claw portion (45) across a fulcrum, and rotates toward the rotating body if the outer diameter of the thread of the bobbin reaches a first predetermined value, and a control device (52) that controls the winding motor to reduce the speed to a second winding speed if the outer diameter of the thread of the bobbin reaches a second predetermined value, and controls the winding motor to stop after rotating a predetermined number of times or a predetermined time at a speed just before stopping if the speed is less than a stop determination speed that is lower than the second winding speed.

Description

Technical Field

[0001] The present invention relates to a thread winding device mounted on a sewing machine. Background Art

[0002] In the past, the winding device installed in the sewing machine included: a driving wheel, the outer periphery of which abuts against a driving pulley equipped on the upper shaft of the sewing machine; a winding shaft, which rotates integrally with the driving wheel; a rotating wrist, which supports the winding shaft so that it can rotate; a winding rod, which is externally connected to the lower wire wound on the bobbin set on the winding shaft; a cam component, which rotates coaxially with the winding rod; and a cam follower, which has a recessed portion that engages with the protrusion of the cam component and is connected integrally with the rotating wrist (for example, refer to patent document 1).

[0003] Moreover, in the above-mentioned winding device, torque is transmitted from the upper shaft of the sewing machine via the drive pulley and the drive wheel relative to the bobbin set on the winding shaft. If the lower thread is wound, the winding rod is gradually rotated according to its winding amount. If the specified amount is reached, the protrusion of the cam component is engaged with the recess of the cam follower, the cam follower and the rotating wrist rotate, the drive wheel is separated from the drive pulley, and the winding is completed.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-29381

[0005] However, the conventional thread winding device utilizes the output of the sewing machine motor as a driving source for thread winding. Therefore, the entire sewing machine must be driven to wind the thread, which is cumbersome. Summary of the Invention

[0006] An object of the present invention is to enable winding of thread on a bobbin without operating a sewing machine.

[0007] The invention described in technical solution 1 is a thread winding device for a sewing machine, which comprises:

[0008] a spool that holds the spool;

[0009] a winding motor that imparts a rotational force to the winding shaft;

[0010] a rotation number detecting unit for detecting the rotation number of the winding motor;

[0011] a rotating body that rotates in conjunction with the winding shaft and has a stopper recess formed on its outer periphery for stopping the rotation; and

[0012] The spool rod has a rod portion at one end thereof that abuts against the outer periphery of the suture wound on the spool held by the winding shaft, and a claw portion at the other end thereof that engages with the stopping recess to stop the rotation of the rotating body, and a support shaft provided between the rod portion and the claw portion, which can rotate around the support shaft.

[0013] The thread winding device of the sewing machine is characterized in that:

[0014] The bobbin lever is configured such that when the outer diameter of the suture wound on the bobbin held by the bobbin reaches a first predetermined value, the claw portion rotates toward the rotating body.

[0015] The winding device of the sewing machine has a control device. If the outer diameter of the suture wound on the bobbin reaches a second specified value smaller than the first specified value, the control device controls the winding motor to decelerate to a second winding speed that is lower than the first winding speed at the start of winding. If the rotation speed based on the detected number of revolutions of the number of revolutions detecting unit is lower than a stop determination speed that is lower than the second winding speed, the control device controls the winding motor to stop after rotating a specified number of times or for a specified time at a speed just before stopping that is lower than the stop determination speed.

[0016] The invention according to claim 2 is characterized in that, in the thread winding device of the sewing machine according to claim 1,

[0017] If the rotation speed based on the detected rotation speed of the rotation speed detection unit is less than the stop judgment speed, the control device controls the winding motor so that it stops after the rotating body rotates for at least one rotation as the specified number of times or the specified time or after one rotation has passed.

[0018] The invention according to claim 3 is characterized in that, in the thread winding device of the sewing machine according to claim 1 or 2,

[0019] A detection unit is provided, which can detect the detected portion provided on the spool rod and output a detection signal,

[0020] The control device determines whether the outer diameter of the suture wound around the bobbin held by the bobbin has reached the second predetermined value in response to the detection signal output from the detection unit.

[0021] The invention according to claim 4 is characterized in that, in the thread winding device of the sewing machine according to any one of claims 1 to 3,

[0022] have:

[0023] a torsion coil spring that imparts an elastic force in a direction in which the claw portion is turned toward the rotating body; and

[0024] a magnet for adsorbing that adsorbs and holds the bobbin shaft at the start of winding,

[0025] If the outer diameter of the thread wound by the bobbin reaches the first prescribed value, the force with which the magnet for adsorbing adsorbs and holds the bobbin shaft is weaker than the elastic force of the torsion coil spring, and the claw portion is turned toward the rotating body.

[0026] Effects of the Invention

[0027] The present invention enables winding of the bobbin by a winding motor other than the sewing machine motor, and thus enables winding of the bobbin without accompanying the operation of the sewing machine.

[0028] Also, in the present invention, it is premised that the winding bobbin is stopped by fitting the locking claw of the bobbin shaft into the stopper recess of the rotating body, but even in the case where the locking claw fails to fit into the stopper recess of the rotating body, the deceleration occurring at that time can be captured by the determination of whether or not it is less than the stop determination speed, and deceleration to the speed just before stopping is stopped, and thus the locking claw can be caused to fit into the stopper recess of the rotating body, and a more reliable motor stop can be achieved. Therefore, winding can be ended at the target winding amount, and the occurrence of excess winding of the thread onto the bobbin can be sufficiently reduced, and appropriate winding can be performed. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is an oblique view of a winding device of a sewing machine as an embodiment of the invention.

[0030] Figure 2 is a plan view in which the structure of a portion of the winding device at the start of winding is omitted.

[0031] Figure 3 is a bottom view in which the structure of a portion of the winding device at the start of winding is omitted.

[0032] Figure 4 is a plan view in which the structure of a portion of the winding device at the end of winding is omitted.

[0033] Figure 5 is a bottom view in which the structure of a portion of the winding device at the end of winding is omitted.

[0034] Figure 6 is a block diagram showing a control system of the winding device.

[0035] Figure 7 is a flowchart of winding control. DETAILED DESCRIPTION

[0036] Hereinafter, the thread winding device of a sewing machine according to the present invention will be described with reference to the accompanying drawings. Figure 1 1 is an oblique view of the winding device 10. Figure 2 This is a top view of the winding device 10 with part of the structure omitted at the start of winding. Figure 3 This is a bottom view. Figure 4 This is a top view of the winding device 10 with part of the structure omitted when winding is completed. Figure 5 This is a bottom view. Figure 6 1 is a block diagram showing a control system of the wire winding device 10 .

[0037] The thread winding device 10 is provided on the upper part of the sewing machine arm in the frame of the sewing machine. In addition, the thread winding device 10 does not utilize the power of the sewing machine motor, which is the sewing drive source of the sewing machine, but is built-in with a thread winding motor 11, which is a drive source for independent thread winding.

[0038] The winding device 10 includes: a winding shaft 20, which holds a bobbin; a winding motor 11, which imparts rotational force to the winding shaft 20; an encoder 12, which is built into a controller 52 described later as a rotation number detection unit for detecting the rotation number of the winding motor 11; a gear cover 30 as a rotating body, which rotates in conjunction with the winding shaft 20 and has a stop groove 31 formed on the outer periphery as a stop recess for stopping the rotation; a bobbin rod 40, which rotates toward the gear cover 30 if the outer diameter of the suture wound on the bobbin (not shown) held by the winding shaft 20 reaches a first specified value; a substrate 50 as a control device, which controls the drive of the winding motor 11; a base 13, which carries the bobbin; and a frame 14, which accommodates the winding motor 11 and the gear cover 30.

[0039] Furthermore, in the winding device 10, the winding shaft 20 is arranged at the center. Figure 1 As shown, the center of the winding shaft 20 is set as the center line C of the winding device 10, one side along the center line C (the base 13 side) is set as "up", and the other side (the substrate 50 side) is set as "down" for the following description.

[0040] Reel 20 as Figure 1 As shown in FIG. 1 , the upper end portion penetrates the center of the base 13 upward, and a slit 21 is formed in the upper end portion along the diameter direction. Figure 2 and Figure 4As shown, a plate-shaped bobbin retaining member 22 is provided, which protrudes radially outward from the bobbin 20. The bobbin 20 is retained by inserting its upper end, which protrudes upward from the base 13, into the bobbin's center hole. The bobbin retaining member 22 protrudes radially outward due to back pressure from a spring member (not shown). Therefore, when the upper end of the bobbin 20 is inserted into the bobbin's center hole, the spring member engages with the bobbin's groove, retaining the bobbin.

[0041] The lower end of the winding reel 20 is connected to the output shaft of the winding motor 11 via a planetary gear mechanism (not shown), and the winding reel 20 rotates at a speed reduced to, for example, one-sixth the output rotational speed of the winding motor 11 .

[0042] The winding motor 11 is exemplified as a three-phase motor, but any motor whose rotational speed can be arbitrarily controlled can be used. The winding motor 11 is housed inside a housing 14 .

[0043] Spool rod 40 as Figure 2 and Figure 4 As shown, it is arranged at the radial outer edge of the upper surface of the frame 14. The spool 40 is fixed to a support shaft 42 that passes through the frame 14 vertically through a long hole 41 by tightening a nut 43. The spool 40 and the support shaft 42 rotate integrally.

[0044] The spool rod 40 is formed by integrating a rod portion 44 and a claw portion 45 via a support shaft 42. Tightening the nut 43 allows these components to become one, rotating about the support shaft 42. The rod portion 44 and the claw portion 45 extend in different radial directions about the support shaft 42. In the following description, one end of the spool rod 40 is referred to as the rod portion 44, and the other end as the claw portion 45.

[0045] The lever portion 44 includes a bent portion 441 that protrudes radially inward about the winding reel 20 , and an operating portion 442 that extends radially outward from the bent portion 441 .

[0046] The bent portion 441 of the spool rod 40 is configured to be inserted between the flanges of the spool loaded on the winding reel 20 and to abut against the outer peripheral portion of the suture wound around the shaft of the spool ( Figure 2 Therefore, the bent portion 441 is pushed back by the suture as the winding amount of the spool increases, and the bent portion 441 is pushed back by the suture. Figure 2 and Figure 4 Clockwise rotation ( Figure 4 location).

[0047] The operating portion 442 extends outward from the outer periphery of the frame 14, and the operator inputs the rotation operation of the spool rod 40 from the operating portion 442. Figure 2 As shown in FIG. 4 , the operating portion 442 is rotated counterclockwise so that the bending portion 441 comes to the center side of the bobbin.

[0048] In addition, the long hole 41 formed in the rod portion 44 of the bobbin rod 40 can move the bent portion 441 in the radial direction when the nut 43 is screwed out. Even in the case of bobbins with different diameters, adjustment can be made so that the bent portion 441 can be pushed back well by the wound suture.

[0049] Claw 45 Figure 4 As shown, a locking claw 451 is formed, and the locking claw 451 can be inserted into the stopper groove 31 formed in the gear cover 30. The locking claw 451 has a tip end facing radially inward with the winding shaft 20 as the center.

[0050] In contrast, the gear cover 30 is generally circular in plan view, with the winding shaft 20 extending through its center and fixed thereto, so that the gear cover 30 and the winding shaft 20 rotate integrally. A retaining groove 31 is formed on the outer periphery of the gear cover 30, concave inward in the radial direction centered on the winding shaft 20.

[0051] Figure 2 The arrow T in FIG. 1 shows the rotation direction of the winding shaft 20 and the gear cover 30 when winding the wire.

[0052] The gear cover 30 is formed with an expanded portion 32. The outer diameter of this expanded portion 32 is larger on the downstream side, across the stop groove 31, than on the upstream side in the rotational direction T during winding. Therefore, when the locking claw 451 advances toward the gear cover 30 due to rotation of the spool lever 40 and abuts the outer circumference of the rotating gear cover 30 excluding the stop groove 31, the locking claw 451 slides along the outer circumference of the gear cover 30, collides with the expanded portion 32, and then plunges into the stop groove 31. This stops the rotation of the spool 20 via the gear cover 30.

[0053] In addition, the support shaft 42 of the spool rod 40, such as Figure 1 As shown, a torsion coil spring 46 is provided to apply elastic force in the direction in which the locking claw 451 of the spool lever 40 rotates radially inward with the winding shaft 20 as the center.

[0054] The support shaft 42 is fixedly provided with an operating arm 47 at its lower end. The operating arm 47 extends radially outward from the support shaft 42 between the bottom surface of the frame 14 and the upper surface of the base plate 50, and the support shaft 42 and the spool rod 40 rotate integrally.

[0055] The working wrist 47 is composed of a magnet, such as Figure 3 As shown, the attracting magnet 48 provided on the bottom surface of the frame 14 is located downstream in the rotational direction associated with the rotation of the spool lever 40 at the start of winding. Therefore, when the spool lever 40 is rotated against the elastic force of the torsion coil spring 46 at the start of winding, the operating arm 47 is attracted and held by the magnetic force of the attracting magnet 48.

[0056] Furthermore, a detection magnet 471, serving as a detected portion, is provided on the lower surface near the rotating end of the operating arm 47. A Hall element 51, serving as a detection unit, is provided on the upper surface of the base plate 50 so as to be closely opposed to the detection magnet 471 of the operating arm 47, which is held by the attracting magnet 48. Therefore, if the spool rod 40 is rotated at the start of winding, this can be detected by the Hall element 51.

[0057] The structure is such that when the working arm 47 begins to be wound onto the spool while being held by the attraction magnet 48, the suture thread wound on the spool contacts the bent portion 441 of the spool rod 40 as the winding progresses, pressing the working arm 47 in the direction of separation from the attraction magnet 48. Furthermore, the structure is adjusted so that when the outer diameter of the suture thread wound on the spool reaches a first predetermined value (equivalent to the target winding amount of the suture thread on the spool), the force of the attraction magnet 48 holding the working arm 47 is weaker than the elastic force of the torsion coil spring 46, the spool rod 40 rotates about the support shaft 42, and the locking claw 451 advances toward the gear cover 30.

[0058] A controller 52 serving as a control device is mounted on the substrate 50 . The controller 52 controls the wire winding operation of the wire winding device 10 .

[0059] The controller 52 is as follows Figure 6 As shown, the winding motor 11 is connected via the drive circuit 111 and the Hall element 51 is directly connected.

[0060] The driving circuit 111 is also mounted on the substrate 50 .

[0061] based on Figure 7 The winding control performed by the above-mentioned controller 52 is described with reference to the flowchart of FIG.

[0062] The empty bobbin is placed on the base 13 and is inserted into and held by the winding bobbin 20. Figure 2 As shown, if the operator rotates the operating portion 442 of the spool lever 40 in the counterclockwise direction, the bent portion 441 enters the inner side of the spool. Figure 3 As shown, the operating arm 47 rotates in the clockwise direction and approaches the adsorption magnet 48 to be adsorbed and held.

[0063] At this time, the controller 52 monitors the proximity (ON) detection of the detection magnet 471 of the working arm 47 by the Hall element 51 (step S1). If the Hall element 51 detects the proximity of the detection magnet 471, the controller 52 starts rotating the winding motor 11 at the first winding speed (e.g., 7200 rpm) (step S3). In addition, the controller 52 starts measuring the elapsed time t1 from the start of winding at the first winding speed using a built-in timer (not shown).

[0064] Next, the controller 52 monitors the separation (OFF) detection of the detection magnet 471 of the operating arm 47 by the Hall element 51 (step S5). Specifically, the separation detection of the detection magnet 471 of the operating arm 47 means that the suture thread wound on the bobbin reaches the target winding amount and its outer diameter exceeds the second predetermined value, the bent portion 441 of the bobbin rod 40 is pushed back, and the operating arm 47 begins to gradually separate from the attracting magnet 48.

[0065] The second predetermined value of the outer diameter of the suture wound on the bobbin is a value smaller than the first predetermined value. The first predetermined value corresponds to the amount of thread wound when the bobbin rod 40 is pushed back by the suture wound on the bobbin, releasing the attraction force of the attraction magnet 48 and causing the locking claw 451 to begin rotating toward the gear cover 30 by the torsion coil spring 46. In other words, the second predetermined value indicates the size of the outer diameter of the suture wound on the bobbin corresponding to the state in which the bobbin rod 40 is pressed by the suture wound on the bobbin and begins rotating against the attraction force of the attraction magnet 48, but has not yet reached a state in which the suture is released from the attraction force.

[0066] Through this monitoring, when the separation of the detection magnet 471 of the working arm 47 is detected by the Hall element 51, the controller 52 controls the winding motor 11 to decelerate to a second winding speed (for example, 1800 [rpm]) lower than the first winding speed (step S7).

[0067] At this time, the controller 52 resets the winding time at the first winding speed t1 started in step S3 to 0. Furthermore, at the same time, the controller 52 starts measuring the elapsed time t2 from the time when the winding at the second winding speed is started.

[0068] On the other hand, when the separation of the detection magnet 471 of the working arm 47 is not detected by the above-mentioned Hall element 51, the controller 52 determines whether the winding time t1 at the first winding speed exceeds the first abnormality judgment value (for example, 120 [sec]) (step S9).

[0069] For example, the first abnormality determination value is set to a value at which the number of times the bobbin is wound is significantly excessive when winding at the first winding speed. If the separation of the detection magnet 471 of the working arm 47 is not detected by the Hall element 51 and a time period corresponding to the first abnormality determination value has elapsed (step S9: YES), it is predicted that an abnormality has occurred in the Hall element 51, or that the bobbin has not been wound with suture thread and has entered an empty winding state, and the controller 52 stops driving the winding motor 11 (step S19), thereby terminating the winding control.

[0070] On the other hand, when it is determined in step S9 that the winding elapsed time t1 at the first winding speed does not exceed the first abnormality determination value (step S9 : NO), the process proceeds to step S11 .

[0071] In addition, when the separation of the detection magnet 471 of the working arm 47 is detected by the Hall element 51 and the speed is reduced to the second winding speed in step S7, the processing is also entered into step S9 to determine whether the winding time t1 at the first winding speed exceeds the first abnormal judgment value. However, in step S7, the winding time t1 at the first winding speed is reset to 0, so in this case, the judgment of step S9 becomes NO, and the processing enters step S11.

[0072] In step S11 , the controller 52 determines whether the winding elapsed time t2 at the second winding speed exceeds a second abnormality determination value (for example, 60 [sec]).

[0073] For example, the second abnormality determination value is set to a value indicating that the number of bobbin windings is significantly excessive when winding is performed at the second winding speed after the separation of the detection magnet 471 of the operating arm 47 is detected by the Hall element 51 .

[0074] When the time that becomes the second abnormal judgment value has passed since the separation of the detection magnet 471 of the working arm 47 was detected by the Hall element 51 (step S11: YES), it is predicted that an abnormality has occurred, such as the thread supply source supplying the suture to the bobbin has run out of sutures or the suture has been cut off in the middle, and the controller 52 stops the drive of the winding motor 11 (step S19), ending the winding control.

[0075] On the other hand, when it is determined in step S11 that the winding elapsed time t2 at the second winding speed does not exceed the second abnormality determination value (step S11 : NO), the process proceeds to step S13 .

[0076] In addition, when the separation of the detection magnet 471 of the working arm 47 is not detected by the Hall element 51 (step S5: NO), and it is determined that the winding time t1 at the first winding speed does not exceed the first abnormal judgment value (step S9: NO), the processing is also entered into step S11 to determine whether the winding time t2 at the second winding speed exceeds the second abnormal judgment value. However, since step S7 is not passed, the winding time t2 at the second winding speed does not start and remains 0. Therefore, in this case, the judgment of step S11 becomes NO, and the processing enters step S13.

[0077] In step S13 , the controller 52 determines based on the output of the encoder 12 whether the current rotation speed of the winding motor 11 is lower than a stop determination speed (eg, 1200 [rpm]) that is lower than the second winding speed.

[0078] That is, the state in which the winding motor 11 is less than the stop judgment speed refers to the following state, namely, the working arm 47 of the spool rod 40 is completely separated from the adsorption magnet 48, and the locking claw 451 collides with the expansion part 32 by rotating through the torsion coil spring 46, so that the rotation of the winding motor 11 is greatly decelerated from the second winding speed, i.e., 1800 [rpm], through the gear cover 30, or the locking claw 451 rushes into the stopping groove 31 and the rotation of the winding motor 11 is stopped through the gear cover 30.

[0079] If the rotation speed of the winding motor 11 is not less than the stop determination speed (step S13: NO), the process returns to step S5 and the separation of the detection magnet 471 of the operating arm 47 is determined again by the Hall element 51.

[0080] If the rotational speed of the winding motor 11 is lower than the stop determination speed (step S13: YES), the rotational speed of the winding motor 11 is decelerated to a speed immediately before stopping (e.g., 300 rpm) that is lower than the stop determination speed (step S15). Furthermore, the controller 52 begins measuring the elapsed time t3 from the moment the deceleration drive starts at the speed immediately before stopping using a built-in timer (not shown).

[0081] Then, when the elapsed time t3 reaches a predetermined time (for example, 0.2 [sec]) (step S17), the driving of the winding motor 11 is stopped (step S19), and the winding control is ended.

[0082] The predetermined time in this case is preferably set to the time (or longer) required to rotate the winding shaft 20 once when driving at the speed just before stopping. For example, if the speed just before stopping is 300 [rpm], the predetermined time is preferably set to 0.2 [sec].

[0083] In addition, the controller 52 performs control to stop the drive of the winding motor 11 when the time t3 reaches the predetermined time, but is not limited to this. The controller 52 may also perform control to stop the winding motor 11 when the winding motor 11 rotates a predetermined number of times at the speed immediately before stopping. The predetermined number of times in this case is preferably set to one rotation (or more).

[0084] [Technical Effects of Embodiments of the Invention]

[0085] The thread winding device 10 winds the thread on the bobbin using the thread winding motor 11 other than the sewing machine motor. Therefore, the thread winding on the bobbin can be performed without operating the sewing machine.

[0086] Furthermore, when the outer diameter of the suture thread wound on the bobbin 20 reaches a second predetermined value that is smaller than the first predetermined value, the controller 52 controls the winding motor 11 to decelerate to a second winding speed that is slower than the first winding speed at the start of winding and faster than the stop determination speed. Therefore, the rotational speed of the gear cover 30 can be set to a low speed at the moment when the outer diameter of the suture thread wound on the bobbin reaches the first predetermined value and the bobbin rod 40 rotates toward the gear cover 30. This can reduce the occurrence of engagement failure of the locking claw 451 and ensure that the locking claw 451 of the bobbin rod 40 is more reliably engaged with the retaining groove 31 of the gear cover 30.

[0087] In addition, if the rotation speed based on the detected number of revolutions of the encoder 12 is lower than the stop determination speed, the controller 52 controls the winding motor 11 so that it rotates for a specified time at a speed just before stopping that is lower than the stop determination speed and then stops, thereby obtaining an opportunity to engage the locking claw 451 of the spool rod 40 with the stopping groove 31 of the gear cover 30 at a lower speed, thereby being able to more reliably engage the locking claw 451 of the spool rod 40 with the stopping groove 31 of the gear cover 30.

[0088] As shown above, the winding device 10 monitors the changes in the outer diameter of the suture wound on the bobbin and the rotational speed of the winding motor 11, and controls the winding motor 11 to stop in two stages, thereby preventing the locking claw 451 of the bobbin rod 40 from failing to engage with the retaining groove 31 of the gear cover 30, and ending the winding with the target winding amount.

[0089] Further, the spool shaft 40 has a detected magnet 471 as a detected portion and a Hall element 51 as a detection unit, so the controller 52 can reliably determine that the outer diameter of the thread wound on the spool 20 reaches the second prescribed value in correspondence with a detection signal output from the Hall element 51.

[0090] Further, the take-up device 10 has a torsion coil spring 46 that imparts an elastic force to the claw portion 45 in a direction in which the claw portion 45 turns toward the gear cover 30, and a suction magnet 48 that holds the spool shaft 40 by suction at the start of take-up, and is configured such that if the outer diameter of the thread wound on the spool reaches the first prescribed value, the force with which the suction magnet 48 holds the spool shaft 40 by suction is weaker than the elastic force of the torsion coil spring 46, and the claw portion 45 turns toward the gear cover 30, so the reaching of the first prescribed value can be detected without sensing or the like. Thus, the structure of the detection can be simplified, and further, detection with stability that is not easily affected by noise or the like can be achieved.

[0091] Further, the controller 52 controls the take-up motor 11 such that if the rotational speed based on the detected number of revolutions of the encoder 12 is less than the stop determination speed, the take-up motor 11 is stopped at least after the gear cover 30 rotates by one revolution or after a time at which one revolution elapses, as a prescribed number of times or a prescribed time, so even in the case where the engagement of the engagement claw 451 of the spool shaft 40 with the stop groove 31 of the gear cover 30 fails, an opportunity for re-engagement is obtained, and the engagement claw 451 of the spool shaft 40 can be more reliably engaged with the stop groove 31 of the gear cover 30.

[0092] [Others]

[0093] Further, the controller 52 of the take-up device 10 can also be configured to execute the function of the controller 52 as one of the functions of a control device of the sewing machine that centrally controls the entire sewing machine.

[0094] Explanation of Reference Numerals

[0095] 10 take-up device

[0096] 11 take-up motor

[0097] 12 encoder (number-of-revolutions detection portion)

[0098] 20 spool

[0099] 30 gear cover (rotating body)

[0100] 31 stop groove (stopper recess)

[0101] 32 expansion portion

[0102] 40 spool shaft

[0103] 42 support shaft

[0104] 45 claws

[0105] 46 Coil Spring

[0106] 47 Working wrist

[0107] 48 magnets for adsorption

[0108] 50 substrates

[0109] 51 Hall element (detection unit)

[0110] 52 controller (control device)

[0111] 451 locking claw

[0112] 471 Magnet for detection (detection part)

Claims

1. A thread winding device for a sewing machine, comprising: a spool that holds the spool; a winding motor that imparts a rotational force to the winding shaft; a rotation number detecting unit for detecting the rotation number of the winding motor; a rotating body that rotates in conjunction with the winding shaft and has a stopper recess formed on its outer periphery for stopping the rotation; and The spool rod has a rod portion at one end thereof that contacts the outer periphery of the suture wound on the spool held by the spool via a support shaft for rotation, and a claw portion at the other end thereof that engages with the stopping recess to stop the rotation of the rotating body. The thread winding device of the sewing machine is characterized in that: The bobbin lever is configured such that when the outer diameter of the suture wound on the bobbin held by the bobbin reaches a first predetermined value, the claw portion rotates toward the rotating body. The winding device of the sewing machine has a control device. If the outer diameter of the suture wound on the bobbin reaches a second specified value smaller than the first specified value, the control device controls the winding motor to decelerate to a second winding speed that is lower than the first winding speed at the start of winding. If the rotation speed based on the detected number of revolutions of the number of revolutions detecting unit is lower than a stop determination speed that is lower than the second winding speed, the control device controls the winding motor to stop after rotating a specified number of times or for a specified time at a speed just before stopping that is lower than the stop determination speed.

2. The thread winding device of a sewing machine according to claim 1, characterized in that If the rotation speed based on the detected rotation speed of the rotation speed detection unit is less than the stop judgment speed, the control device controls the winding motor so that it stops after the rotating body rotates for at least one rotation as the specified number of times or the specified time or after one rotation has passed.

3. The thread winding device of a sewing machine according to claim 1 or 2, characterized in that: A detection unit is provided, which can detect the detected portion provided on the spool rod and output a detection signal, The control device determines whether the outer diameter of the suture wound around the bobbin held by the bobbin has reached the second predetermined value in response to the detection signal output from the detection unit.

4. The thread winding device for a sewing machine according to claim 1 or 2, characterized in that: have: a torsion coil spring that applies elastic force to the claw portion in a direction in which the claw portion rotates toward the rotating body; and An adsorption magnet that adsorbs and holds the spool rod at the start of winding. When the outer diameter of the suture wound on the bobbin reaches the first predetermined value, the force of the attraction magnet to attract and hold the bobbin rod becomes weaker than the elastic force of the torsion coil spring, and the claw rotates toward the rotating body.

5. The thread winding device for a sewing machine according to claim 3, characterized in that: have: a torsion coil spring that applies elastic force to the claw portion in a direction in which the claw portion rotates toward the rotating body; and An adsorption magnet that adsorbs and holds the spool rod at the start of winding. When the outer diameter of the suture wound on the bobbin reaches the first predetermined value, the force of the attraction magnet to attract and hold the bobbin rod becomes weaker than the elastic force of the torsion coil spring, and the claw rotates toward the rotating body.

Images