JP2006061605A - Rotating thread take-up device of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the tightness of stitches in both left/right needle locations respectively when a needle bar swings between a right needle swing position and a left needle swing position. <P>SOLUTION: A rotating thread take-up device 20 of a zigzag chain stitching machine 1 is provided with; a rotating thread take-up lever 9 interlockedly connected to a main spindle 4 so as to rotate synchronously thereto; a needle swing mechanism 6 swinging a needle bar 10; a transmission supporting member 21 fixed to a needle bar crank 12 connected to the main spindle 4, transmitting the rotating force to the rotating thread take-up lever 9, and supporting the rotating thread take-up lever 9; and a phase adjusting mechanism 22 capable of transmitting the rotating driving force of the transmission supporting member 21 to the rotating thread take-up lever 9, and adjusting the rotation phase of the rotating thread take-up lever 9 to the main spindle 4 by being interlocked with the swing of the needle bar 10. The phase adjusting mechanism 22 is provided with an internal tooth forming member 25 formed with a helical spline internal tooth, and an external tooth forming member 26 having a helical spline external tooth threadedly engaged with the helical spline internal tooth. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotary balance that rotates in synchronization with a main shaft so that the phase with respect to the main shaft can be adjusted as appropriate by swinging the needle bar to the right and to the left.

  2. Description of the Related Art Conventionally, a decorative sewing machine such as an eyelet perforated sewing machine, a double chain stitch sewing machine, a staggered sewing machine or the like is generally provided with a rotary balance that rotates in conjunction with a sewing machine main shaft. This type of rotary balance is formed in a substantially T-shape in front view having an upper thread hook portion, and in the middle of the thread path from the thread supply source to the sewing needle when rotating in synchronization with the main spindle of the sewing machine, Since a part of the upper thread fed from the source engages with the upper thread hook, the amount of thread taken by the rotary balance can be adjusted.

  By the way, the texture of stitches (the degree of stitch clogging) often changes depending on the type and thickness of the work cloth, as well as the type and thickness of the sewing thread. Accordingly, various types of rotary balance devices for sewing machines have been proposed in which the phase of the thread take-up amount curve by the rotary balance can be adjusted so as to be advanced or delayed so that the appearance of the texture can be arbitrarily changed.

For example, a rotary sewing machine for a sewing machine of a sewing machine disclosed in Patent Document 1 is a base disk attached concentrically with a sewing machine main shaft, a base disk rotating in the same direction and at the same angular speed as the main shaft, Several inner thread contact pins attached to the disk, one disk supported concentrically on the front surface of the base disk by the inner thread contact pins, and the number attached to the front surface of the disk And an outer sewing thread contact pin, and an adjustment fixing device that can adjust and fix the mounting angle of the disk with respect to the base disk. By adjusting the mounting angle, the shape of the change curve of the thread take-up amount is changed. It is adjusted so that the thread take-up action can be adapted to various sewing conditions.
Japanese Examined Patent Publication No. 37-17183 (pages 1 and 2, FIGS. 1 and 2)

  As described above, in the rotary sewing machine for a sewing machine described in Patent Document 1, the shape of the change curve of the sewing thread take-up is changed and adjusted by adjusting the mounting angle of the adjusting and fixing device. Alternatively, the appearance of stitching can be changed according to consumer preference.

  By the way, for example, in the case of a staggered sewing machine that forms a staggered stitch, the needle bar swings so that the needle drops alternately on the right side and the left side. For this reason, not only does the timing of the contact between the sword tip of the outer hook of the rotary hook and the eye of the sewing needle differ depending on the right policy swing position and the left policy swing position of the needle bar, but also the upper thread loop hooked on the sword tip. The timing for exiting the rotary hook is also different. In other words, when the rotation direction of the rotary hook is counterclockwise as viewed from the operator, the timing of encountering the stitch hole of the sewing needle and the timing of thread removal of the upper thread loop are earlier when the needle swings to the right. Slower when swinging left.

  However, the rotation phase of the rotary balance and the phase of the needle bar's vertical movement are basically set based on when the blade tip of the rotary hook comes to the approximate center of the needle swinging width. The thread tightening at each of the left and right sides is not optimal.

  Therefore, in the case of adopting the rotary sewing machine of Patent Document 1, the mounting angle of the disk with respect to the base disk so as to obtain the optimum thread tightening for the rightward or leftward swing. Can be adjusted during sewing, but cannot be changed during sewing, so either of the right hand swing position and the left hand swing position is adjusted so that the thread tightening is improved. There is a problem that the thread tightening in the other needle swinging deteriorates and the thread tightening cannot be improved at any of the needle drop positions on the left and right sides of the needle bar.

  The rotary balance device for a sewing machine according to claim 1 is a rotary balance device for a sewing machine having a rotary balance interlocked and connected to the main shaft of the sewing machine and a needle swinging mechanism for swinging the needle bar. A transmission support member that is fixed to the needle bar crank and transmits the rotational driving force to the rotary balance and supports the rotary balance, and the rotational driving force of the transmission support member can be transmitted to the rotary balance and can be used to swing the needle bar. And a phase adjustment mechanism that adjusts the rotation phase of the rotary balance relative to the main shaft.

  When the main shaft is rotated by the sewing machine motor, the transmission support member is rotated through a needle bar crank connected to the main shaft, and the rotational driving force of the transmission support member is transmitted to the rotary balance, and the rotary balance is rotated by the driving force. Since it rotates, the predetermined thread take-up amount curve by the rotary balance with respect to the predetermined hook yarn amount curve is obtained.

  By the way, when the phase adjustment mechanism is adjusted so that the rotation phase of the rotary balance relative to the main shaft is advanced relative to the rotation phase of the main shaft in conjunction with the needle swing of the needle bar, the phase of the balance thread take-up curve is changed. When it is adjusted so as to be delayed with respect to the rotation phase of the main shaft in conjunction with the needle swing of the needle bar, the balance thread take-off curve The phase is delayed with respect to the conventional take-up thread curve (reference) at the center of needle bar swing. Therefore, the optimum thread tightening can be realized in both the rightward swing and the leftward swing of the needle bar.

  A rotary balance device for a sewing machine according to a second aspect of the present invention is the rotary balance device for a sewing machine according to the first aspect, wherein the phase adjusting mechanism includes a groove cam and a first engagement member that engages with each other via a cam portion that engages with the groove cam. A first engagement member, which is mounted on the transmission support member so as to be concentric with the axis of the main shaft and is movable in the axial direction, and is driven to rotate by a rotational driving force from the transmission support member. A combination member, a second engagement member to which a base end portion of the rotary balance is fixed, and a horizontal movement transmission mechanism for transmitting a needle swing horizontal movement of a needle bar base drive shaft of the needle swing mechanism to the first engagement member. It is provided.

  According to a third aspect of the present invention, there is provided a rotary balance device for a sewing machine according to the second aspect, wherein the first engagement member is formed with a first helical spline engagement tooth concentric with the axis of the main shaft. The second engagement member is a second engagement tooth forming member having a second helical spline engagement tooth meshed with the first helical spline engagement tooth.

  According to a fourth aspect of the rotary balance device for a sewing machine of the present invention, in the invention according to any one of the first to third aspects, the phase adjusting mechanism may be used when the rotation direction of the yarn catching hook is counterclockwise as viewed from the operator of the sewing machine. When the needle bar swings to the right, the rotational phase of the rotary balance is advanced, and when the needle bar swings to the left, the rotational phase of the rotary balance is delayed.

  A rotary balance device for a sewing machine according to a fifth aspect of the present invention is the rotary balance device for a sewing machine according to any one of the first to third aspects, wherein the phase adjusting mechanism is configured such that the rotation direction of the yarn catching hook is clockwise when viewed from the operator of the sewing machine. When the needle bar swings leftward, the rotational phase of the rotary balance is advanced, and when the needle bar swings rightward, the rotational phase of the rotary balance is delayed.

  A rotary balance device for a sewing machine according to a sixth aspect of the present invention is the rotary balance device for a sewing machine according to any one of the second to fifth aspects, wherein the horizontal movement transmission mechanism is configured to change a horizontal movement amount by the needle swing mechanism by a distance corresponding to a phase change amount of the rotary balance. The first engaging member has a link mechanism that slides in the axial direction of the main shaft.

  According to the first aspect of the present invention, there is provided a rotary balance device for a sewing machine having a rotary balance interlocked and coupled to rotate synchronously with a main shaft of the sewing machine and a needle swinging mechanism for swinging a needle bar. Since the adjustment mechanism is provided, when the needle bar is swung in the right direction and the rotation phase with respect to the main axis of the rotary balance is adjusted when the needle is swung to the right, It can be advanced with respect to the conventional balance thread take-up curve (reference) at the center of the bar swing, and the optimum thread tightening can be realized for the right hand swinging.

  On the other hand, when the needle bar is swung to the left and the rotation phase with respect to the spindle of the rotary balance is adjusted to be delayed when the needle is swung to the left, the phase of the take-up thread take-up curve is set at the center of the needle bar swing. The thread can be delayed with respect to the conventional balance thread take-up amount curve (reference), and the optimum thread tightening for the left needle swing can be realized.

  According to the invention of claim 2, the phase adjusting mechanism is a first engaging member and a second engaging member that are engaged with each other via a groove cam and a cam portion that engages with the groove cam. A first engagement member mounted on the transmission support member so as to be rotatable concentrically with the axis of the main shaft and movable in the axial direction, and driven to rotate by a rotational driving force from the transmission support member; and a base end of the rotary balance And a horizontal movement transmitting mechanism for transmitting the horizontal movement of the needle bar base drive shaft of the needle swing mechanism to the first engagement member. When the first engagement member is moved in the axial direction of the main shaft by the horizontal movement of the needle bar base drive shaft by the swing mechanism, the first engagement member is engaged with the first engagement member via the groove cam and the cam portion. The mating second engaging member rotates clockwise or counterclockwise depending on the amount of movement of the first engaging member. Therefore, in synchronization with the needle swing to the left and right of the needle bar, a rotational phase with respect to the main axis of the fixed rotary balance with the second engaging member can be easily and reliably adjusted to the advanced side or retarded side. Other effects similar to those of the first aspect are obtained.

  According to a third aspect of the present invention, the first engagement member is a first engagement tooth forming member formed with first helical spline engagement teeth concentric with the axis of the main shaft, and the second engagement member. Is a second engaging tooth forming member having a second helical spline engaging tooth meshed with the first helical spline engaging tooth, and therefore, the first helical spline engaging tooth of the first engaging tooth forming member; The phase adjustment of the rotary balance can be speeded up and smoothed by the engagement (engagement) of the second engagement tooth forming member with the second helical spline engagement teeth. Other effects similar to those of claim 2 are achieved.

  According to a fourth aspect of the present invention, the phase adjusting mechanism rotates when the needle bar swings rightward when the rotation direction of the yarn catching hook is counterclockwise as viewed from the operator of the sewing machine. When the scale of the balance is advanced and the needle bar swings to the left, the rotational phase of the rotary scale is delayed, so the timing of thread removal from the thread catching hook of the upper thread loop is early. Thread tightening with a rotary balance is accelerated, so that it is possible to achieve optimum thread tightening for needle swinging to the right and needle swinging to the left with a slow timing of thread removal from the thread catching hook of the upper thread loop. Occasionally, the thread tightening by the rotary balance is delayed, so that it is possible to realize the thread tightening optimum for the leftward swinging of the needle. Other effects similar to those of any one of claims 1 to 3 are provided.

  According to the invention of claim 5, the phase adjusting mechanism is a rotary balance when the needle bar swings leftward when the rotation direction of the thread catching hook is clockwise as viewed from the operator of the sewing machine. When the needle bar swings to the right, the rotation phase of the rotary balance is delayed, so when the needle swings to the left, the timing of thread removal from the thread catching hook of the upper thread loop is early, Thread tightening with the rotary balance is accelerated, so that it is possible to achieve optimum thread tightening for needle swinging to the left, and at the time of needle swinging to the right where the timing of thread removal from the thread catching hook of the upper thread loop is slow Since the thread tightening by the rotary balance is delayed, it is possible to realize the optimum thread tightening for the rightward needle swing. Other effects similar to those of any one of claims 1 to 3 are provided.

  According to the invention of claim 6, the horizontal movement transmission mechanism slides the first engagement member in the axial direction of the main shaft by a distance corresponding to the phase change amount of the rotary balance by the horizontal movement amount by the needle swing mechanism. Since it has a link mechanism, regardless of the amount of horizontal movement by the needle swing mechanism, the amount of horizontal movement can be easily changed to a distance corresponding to the phase change amount of the rotary balance, regardless of the configuration of the link mechanism. It is possible to realize the phase change of the rotary balance that is optimal for the needle swing width. Other effects similar to those of any one of claims 2 to 5 are achieved.

  The rotary balance device of the sewing machine according to the present embodiment includes a transmission support member that is fixed to a needle bar crank of a needle bar vertical movement mechanism and rotates synchronously with a main shaft, an internal tooth forming member having helical spline internal teeth, and a helical spline external tooth. Rotation mechanism with respect to the main shaft of the rotary balance by providing a phase adjusting mechanism equipped with an external tooth forming member, etc., and horizontally moving the engagement position of the internal tooth forming member with the external tooth forming member in conjunction with the needle swing of the needle bar The phase is adjustable.

  As shown in FIGS. 1 to 3, the main shaft 4 disposed in the left-right direction on the arm portion 2 of the staggered sewing machine 1 is rotatably supported at a plurality of locations on the machine frame 2 </ b> A, and the head 3 of the arm portion 2. Are provided with a needle bar up-and-down moving mechanism 5 that is connected to the left end of the main shaft 4 to drive the needle bar up and down, a needle swinging mechanism 6 that swings the needle bar left and right, and the like. 8 is provided. First, the needle bar vertical movement mechanism 5 will be briefly described.

  The needle bar 10 is supported by a U-shaped needle bar base 11 that is supported by the machine frame 2A so as to be movable in the left-right direction, and can be moved up and down. On the other hand, a needle bar crank (balance weight) 12 having a connecting pin 12a is fixed to the left end portion of the main shaft 4, and the upper end portion of the needle bar crank rod 13 is pivotally attached to the connecting pin 12a.

  A horizontal slide pin 14 is supported at the lower end of the needle bar crank rod 13 so as to be slidable in the left-right direction, and the left end (tip) of the slide pin 14 is fixed to the vicinity of the upper end of the needle bar 10. 15 is connected. Therefore, the rotation of the main shaft 4 causes the needle bar crank rod 13 to move up and down via the needle bar crank 12, so that the needle bar moves up and down simultaneously via the needle bar holder 15 connected thereto.

  Next, since the needle swing mechanism 6 has a general configuration, it will be briefly described. The needle swing mechanism 6 is connected to a needle swing motor (not shown) formed of a stepping motor, a needle bar base drive shaft 17 connected to the needle swing motor, a slide pin 14, and a needle bar base drive shaft 17. It has a needle bar base 11 and the like.

  When the needle swing motor is driven in the forward direction, as shown in FIGS. 2-1 and 4, the needle bar base drive shaft 17 moves horizontally by a predetermined distance to the right, so that the slide pin 14 moves to the right. While sliding, the needle bar base 11 and the needle bar 10 simultaneously swing to the right hand swing position.

  When the needle swing motor is driven in reverse, as shown in FIGS. 3A and 3B, the needle bar base drive shaft 17 moves horizontally by a predetermined distance to the left so that the slide pin 14 slides to the left. At the same time, the needle bar base 11 and the needle bar 10 simultaneously swing to the left hand swing position.

  Next, the rotary balance device 20 will be described. The rotary balance device 20 is fixed to a needle bar crank 12 connected to the main shaft 4, transmits a rotational force to the rotary balance 9 and supports the rotary balance 9, and rotational drive of the transmission support member 21. A phase adjustment mechanism 22 that can transmit force to the rotary balance 9 and adjusts the rotational phase of the rotary balance 9 relative to the main shaft 4 in conjunction with the swinging of the needle bar 10 is provided.

  As shown in FIGS. 2-1 to 3-1, a transmission support member 21 for transmitting a rotational driving force to the rotary balance 9 and supporting the rotary balance 9 is fixed to the left end portion of the connecting pin 12a. As shown in FIG. 2A, the transmission support member 21 has a substantially crank shape when viewed from the front, and a columnar connecting portion 21a is formed at the left end portion thereof as shown in FIG. A key member 23 facing left and right is fixed in a protruding manner at one end of the outer peripheral portion.

  Next, the phase adjustment mechanism 22 will be described. As shown in FIGS. 2-1, 3-1 and 6, the phase adjusting mechanism 22 includes an internal tooth forming member 25 in which helical spline internal teeth 25b (which correspond to first helical spline engaging teeth) are formed. (This is the first engaging member and corresponds to the first engaging tooth forming member), and the helical spline outer teeth 26a meshing with the inner tooth forming member 25 (this corresponds to the second helical spline engaging teeth). ) Formed on the external tooth forming member 26 (this is the second engaging member and corresponds to the second engaging tooth forming member), and the needle swing horizontal movement of the needle bar base drive shaft 17 of the needle swing mechanism 6 The horizontal movement transmission mechanism 27 etc. which transmit this to the internal tooth formation member 25 are provided.

  The inner tooth forming member 25 has helical spline inner teeth 25b concentric with the axis of the main shaft 4 on the inner peripheral portion of the annular tooth forming portion 25a, and the lead angle with respect to the axis of the main shaft 4 is viewed from the left. Thus, helical spline inner teeth 25b having a predetermined angle (for example, about 27 °) are formed counterclockwise. The inner tooth forming member 25 is fitted into the base end portion of the connecting portion 21a, and is supported by the connecting portion 21a so as to be movable in the left-right direction via an annular support wall portion 25c protruding to the inner peripheral side at the right end portion. .

  Further, a key groove 25d facing in the left-right direction is formed at one place on the inner peripheral side of the support wall portion 25c, and is engaged with the key member 23 of the connecting portion 21a so as to be movable in the left-right direction.

  On the other hand, the external tooth forming member 26 in which the helical spline external teeth 26a are formed on the outer peripheral portion has the same lead angle (for example, about 27 °) as the helical spline internal teeth 25b, and the internal tooth forming member 25 from the left side. The left end portion (tip portion) of the connecting portion 21a is fitted into a cylindrical connecting concave portion 26b formed inside thereof, and is connected to the connecting portion 21a by a set screw 28 so as to be rotatable through pressing friction. Has been. The base end portion 9a of the rotary balance 9 is fixed to the left end surface of the external tooth forming member 26 with a plurality of fixing screws (not shown).

  In this way, the inner tooth forming member 25 is parallel to the axis of the main shaft 4 as shown in FIG. 2A with respect to the outer tooth forming member 26 rotatably supported by the left end portion of the transmission support member 21. When the internal tooth forming member 25 is slid to the rightward moving position, the external tooth forming member 26 cannot rotate with respect to the transmission support member 21 via the key member 23 and the key groove 25d. 25b and the helical spline external teeth 26a are rotated clockwise as viewed from the left to advance the rotational phase of the rotary balance 9 relative to the main shaft 4 (see the two-dot chain line in FIG. 1 and FIG. 7).

  On the contrary, as shown in FIG. 3A, the inner tooth forming member 25 is parallel to the axis of the main shaft 4 with respect to the outer tooth forming member 26 rotatably supported by the left end portion of the transmission support member 21. When slid to the leftward movement position, the internal tooth forming member 25 cannot rotate independently with respect to the transmission support member 21 via the key member 23 and the key groove 25d, so that the external tooth forming member 26 becomes the helical spline internal tooth 25b. And the helical spline external teeth 26a are rotated counterclockwise as viewed from the left through the meshing of the helical spline external teeth 26a to delay the rotational phase of the rotary balance 9 relative to the main shaft 4 (see the solid line in FIG. 1 and FIG. 7).

  As shown in FIGS. 1 to 3-1, the rotary balance 9 is composed of a rotating arm portion 9b extending from the base end portion 9a, an upper thread holding portion 9c of the tip end portion, and the like, and rotating with the base end portion 9a. A first upper thread holding point 9d and a second upper thread holding point 9e are formed between the arm portion 9b. By the way, as shown in FIGS. 1 and 2-1, a face plate cover 30 is fixed to an end portion of the machine casing 2A, and a left end portion of the external tooth forming member 26 is inserted into a circular opening 30a formed in the face plate cover 30. It is exposed to the outside.

  As shown in FIGS. 2-1 and 3-1, a balance cover 32 is provided on the head 3 so that the upper thread 18 hooked on the upper thread holding portion 9c of the rotary balance 9 does not come off. Each of the balance covers 32 is formed with a balance recess 32a.

  Therefore, the balance cover 32 is fixed to the face plate cover 30 with a fixing screw 33 via a pair of cylindrical support members 30b formed on the face plate cover 30, and the upper thread holding portion 9c of the rotary balance 9 is connected to the balance recess portion 32a. Therefore, the upper thread 18 is prevented from coming off from the upper thread holding portion 9c during sewing.

  Next, the horizontal movement transmission mechanism 27 will be described. This horizontal movement transmission mechanism 27 causes the internal tooth forming member 25 to move the horizontal movement amount by the needle swing mechanism 6 by a distance (for example, about 3 mm) corresponding to the phase change angle (for example, about 8 °) of the rotary balance 9. 4 has a link mechanism 35 that slides in the axial direction.

  That is, as shown in FIGS. 2-1 and 2-2, the connecting pin 36 is fixed to the upper end portion of the needle bar base 11, and is rotated by the pivot pin 37 to the machine frame 2 </ b> A on the rear side of the needle bar base 11. A connecting pin 36 is fitted into a bifurcated portion 38a formed at the front end portion of the first link 38 that is pivotally supported. A second link 39 arranged in the front-back direction in the face plate cover 30 is pivotally supported by a pivot pin 40 at the center in the longitudinal direction, and the rear end of the first link 38 and the second link 39 is connected to both ends of the third link 43 by connecting pins 41 and 42, respectively.

  A roller 44 is pivotally attached to the front end portion of the third link 43 and is engaged with an annular groove portion 25e formed in the internal tooth forming member 25 from below. Here, the ratio of the distance from the pivot pin 37 to the connection pin 36 of the first link 38 and the distance from the pivot pin 37 to the connection pin 42 is about 2.7: 1, and the maximum needle swing amount of the needle bar 10 is If it is 8 mm, the sliding amount of the internal tooth forming member 25 is about 3 mm.

  As a result, since the lead angle between the helical spline outer teeth 26a and the helical spline inner teeth 25b is about 27 °, the inner tooth forming member 25 moves rightward relative to the outer tooth forming member 26 in parallel with the axis of the main shaft 4. When the position is slid by about 3 mm, the external tooth forming member 26 is rotated about 8 ° clockwise as viewed from the left, and the rotational phase of the rotary balance 9 relative to the main shaft 4 is advanced by 8 °.

  On the contrary, when the internal tooth forming member 25 slides about 3 mm to the left movement position parallel to the axis of the main shaft 4 with respect to the external tooth forming member 26, the external tooth forming member 26 is viewed from the left. It rotates about 8 ° counterclockwise and delays the rotation phase of the rotary balance 9 relative to the main shaft 4 by 8 °. Here, the first to third links 38, 39, 43, the pivot pins 37, 40, the connecting pins 36, 41, 42, and the like constitute a link mechanism 35.

  Next, the operation of the rotary balance device 20 configured as described above will be described.

  As shown in FIG. 1, at the start of sewing, the upper thread 18 extending from a thread spool (not shown) passes through the first thread guide member 45 provided on the face plate cover 30, and then the rotating arm portion 9 b or the upper thread holding portion of the rotary balance 9. After being hooked on 9c, the upper threading is performed along a predetermined thread path through the second thread guide member 46, through the needle bar thread guide (not shown) to the eye hole 7a of the sewing needle 7. .

  When the sewing start switch is operated after the preparation for sewing is completed, the spindle 4 is rotated in a predetermined rotational direction by a sewing motor (not shown), so that the needle bar 10 is moved via the needle bar vertical movement mechanism 5. And the rotational driving force of the main shaft 4 is sequentially transmitted to the transmission support member 21, the internal tooth forming member 25, and the external tooth forming member 26, and the rotary balance 9 is synchronized with the main shaft 4. Driven by rotation. At the same time, the needle bar 10 is alternately switched between the left policy swing position and the right policy swing position by the needle swing mechanism 6. Therefore, zigzag stitches are sequentially formed on the work cloth by cooperation with the sword tip 8a provided on the outer hook of the rotary hook 8 provided on the bed portion of the staggered sewing machine 1.

  In this case, when the rotation direction of the rotary hook 8 is counterclockwise when viewed from the operator of the staggered sewing machine 1, the needle bar 10 swings rightward by the needle swing mechanism 6 (FIGS. 2-1 and 2). 2-2, see FIG. 4), as described above, the internal tooth forming member 25 slides to the rightward moving position by about 3 mm via the link mechanism 35 of the horizontal movement transmitting mechanism 27, so that the external tooth forming member 26 Rotates clockwise as viewed from the left, and advances the phase of the rotary balance 9 fixed to the external tooth forming member 26 by about 8 °. As a result, as shown in FIG. 9, a take-up thread curve (phase advance) obtained by advancing a predetermined phase (about 8 °) with respect to the conventional take-up thread curve (reference) at the center of needle swing is obtained. .

  On the other hand, when the needle bar 10 swings leftward by the needle swing mechanism 6 (see FIGS. 3-1, 3-2, and 5), as described above, the link mechanism 35 of the horizontal movement transmission mechanism 27 is used. Since the internal tooth forming member 25 slides to the left movement position by about 3 mm, the external tooth forming member 26 rotates counterclockwise when viewed from the left, and the rotary balance fixed to the external tooth forming member 26. 9 is delayed by about 8 °. As a result, as shown in FIG. 9, a take-up thread curve (phase delay) delayed by a predetermined phase (about 8 °) with respect to the conventional take-up thread curve (reference) at the center of needle swing is obtained.

  Here, the change of the needle bar 10 to the left and right needle swing positions by the needle swing mechanism 6 is executed near the uppermost position of the needle bar 10 and the rotational phase of the rotary balance 9 is changed at that time. There is absolutely no trouble in each stitch formed while performing the swing.

  As described above, in the rotary balance device 20 of the staggered sewing machine 1 having the rotary balance 9 interlocked and connected to the main shaft 4 and the needle swinging mechanism 6 for swinging the needle bar 10, the transmission support member 21 and Since the phase adjusting mechanism 22 is provided, the phase of the balance thread take-up curve is adjusted when the needle bar 10 is adjusted so that the rotational phase of the rotary balance 9 with respect to the main shaft 4 is advanced in conjunction with the needle swing of the needle bar 10. It can be advanced with respect to the conventional balance thread take-up curve (reference) at the center of the movement, and the optimum thread tightening for the right hand swinging can be realized.

  On the other hand, when adjusted so as to delay the rotational phase of the rotary balance 9 relative to the main shaft 4 in conjunction with the needle swing of the needle bar 10, the phase of the take-up thread take-up curve is changed to the conventional take-up thread take-up amount at the center of needle bar swing. The thread can be delayed with respect to the curve (reference), and the optimum thread tightening for the left hand swing can be realized.

  In addition, the phase adjustment mechanism 22 includes an internal tooth forming member 25 in which helical spline internal teeth 25b are formed, an external tooth forming member 26 having helical spline external teeth 26a, and a horizontal movement transmission mechanism 27. When the internal tooth forming member 25 is moved in the axial direction of the main shaft 4 by the horizontal movement of the needle bar base drive shaft 17 by the needle swing mechanism 6 during swinging, the helical spline internal teeth 25b of the internal tooth forming member 25 are moved. Since the external tooth forming member 26 having the helical spline external teeth 26a meshing with the internal tooth forming member 25 is rotated clockwise or counterclockwise according to the movement amount of the internal tooth forming member 25, the needle bar 10 is synchronized with the needle swinging left and right. Thus, the rotational phase of the rotary balance 9 fixed to the external tooth forming member 26 with respect to the main shaft 4 can be easily and reliably adjusted to the advance side or the delay side with a simple member configuration.

  Further, the phase adjusting mechanism 22 is configured so that when the needle bar 10 swings rightward when the rotation direction of the rotary hook 8 is counterclockwise when viewed from the operator of the staggered sewing machine 1, the rotational phase of the rotary balance 9 is rotated. When the needle bar 10 swings leftward, the rotational phase of the rotary balance 9 is delayed. Therefore, when the needle threading of the upper thread 18 from the rotary hook 8 is early, the rotary balance is swung to the right. Since the thread tightening by 9 is accelerated, the optimum thread tightening can be realized in the needle swinging to the right.

  On the other hand, when the needle threading of the upper thread 18 from the rotary hook 8 is delayed to the left, the thread tightening by the rotary balance 9 is delayed. Can do.

  Further, the horizontal movement transmission mechanism 27 has a link mechanism 35 that slides the internal tooth forming member 25 in the axial direction of the main shaft 4 by the distance corresponding to the phase change amount of the rotary balance 9 by the horizontal movement amount by the needle swing mechanism 6. Therefore, regardless of the amount of horizontal movement by the needle swing mechanism 6, the horizontal movement amount can be easily changed to a distance corresponding to the phase change amount of the rotary balance 9 depending on the configuration of the link mechanism 35. It is possible to realize the phase change of the rotary balance that is optimal for the ten needle swing widths.

  Next, a modified embodiment in which the embodiment is partially modified will be described.

  1] As shown in FIG. 9, one or a plurality of (for example, four) spiral groove cams 26c are formed at equal intervals on the outer periphery of the outer tooth forming member 26A, and the inner periphery of the inner tooth forming member 25A. One or a plurality of (for example, four) helical cam portions 25f that can be engaged with the groove cams 26c are formed in the portion, and the internal tooth forming member 25A is formed via the groove cams 26c and the cam portions 25f. The external tooth forming members 26A may be engaged with each other. Moreover, you may make it comprise the cam part 25f with a pin member.

  Further, one or a plurality of (for example, four) helical cam portions are formed on the outer peripheral portion of the outer tooth forming member 26A, and one or a plurality (for example, four) are formed on the inner peripheral portion of the inner tooth forming member 25A. ) Spiral groove cam, and the inner tooth forming member 25A and the outer tooth forming member 26A may be engaged with each other through the groove cam and the cam portion. Moreover, you may make it comprise a cam part with a pin member.

  2] The phase adjusting mechanism 22 advances the rotational phase of the rotary balance 9 and the needle bar when the needle bar 10 swings leftward when the rotation direction of the rotary hook 8 is clockwise when viewed from the operator. When the hand 10 swings to the right, the rotational phase of the rotary balance 9 may be delayed. In this case, when the needle threading of the upper thread 18 from the rotary hook 8 is early, the thread tightening by the rotary balance 9 is accelerated, so that the optimum thread tightening for the needle swinging to the left is realized. When the needle threading of the upper thread 18 from the rotary hook 8 is delayed to the right, the thread tightening by the rotary balance 9 is delayed, so that the optimum thread tightening for the needle swinging to the right is realized. be able to.

  3] The link mechanism 35 of the horizontal movement transmission mechanism may be composed of various link mechanisms in which one or a plurality of link plates are combined. In this case, the link mechanism 35 can be configured such that the sliding amount of the internal tooth forming member 25 with respect to the maximum needle swing amount of the needle bar 10 can be varied.

  4) The link mechanism 35 may be omitted, and the internal tooth forming member 25 may be directly driven by a solenoid, an air cylinder, or the like, or may be driven by an electric actuator such as a stepping motor or a DC servo motor.

  5] The lead angle and twist direction of the helical spline inner teeth 25b and the helical spline outer teeth 26a may be appropriately set according to the amount of needle swing and the sliding amount of the inner tooth forming member 25.

  6] DLC coating (with diamond-like carbon coating on the helical spline inner teeth 25b, helical spline outer teeth 26a, cam part 25f, etc. The teeth 25b can be slid and driven.

  7) Needless to say, the present invention can be applied to a rotary balance device for various sewing machines having a rotary balance, such as an eyelet-punching sewing machine or a decorative sewing machine that forms a piggy-hole sewing machine.

It is the side view of the head which removed the balance cover of the staggered sewing machine which concerns on the Example of this invention. It is a front view which shows the internal structure (right policy swing state) of the head of a staggered sewing machine. It is a top view of the link mechanism of a right policy swing state. It is a front view which shows the internal structure (left policy swing state) of the head of a staggered sewing machine. It is a top view of the link mechanism of the left policy swing state. It is a rear view of a needle bar and a rotary hook that are swung to the right. It is a rear view of the needle bar and the rotary hook that are swung to the left. It is a disassembled perspective view of a transmission support member, an internal tooth formation member, and an external tooth formation member. It is a table | surface explaining the correlation of needle bar rocking | fluctuation and the rotation phase of a rotary balance. It is a diagram which shows a shuttle thread amount curve and a balance thread take-up amount curve when swinging left and right. FIG. 7 is a diagram corresponding to FIG. 6 according to a modified embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Staggered sewing machine 4 Main shaft 6 Needle swing mechanism 8 Rotary hook 9 Rotary balance 10 Needle bar 12 Needle bar crank 17 Needle bar base drive shaft 20 Rotary balance device 21 Transmission support member 22 Phase adjustment mechanism 25 Internal tooth formation member 25b In a helical spline Tooth 25f Cam portion 26 External tooth forming member 26a Helical spline external tooth 26c Groove cam 27 Horizontal movement transmission mechanism 35 Link mechanism 38 First link 39 Second link 43 Third link

Claims (6)

In a rotary balance device for a sewing machine having a rotary balance interlocked and coupled to rotate synchronously with the main shaft of the sewing machine and a needle swinging mechanism for swinging a needle bar,
A transmission support member that is fixed to a needle bar crank connected to the main shaft, transmits a rotational driving force to the rotary balance, and supports the rotary balance;
A phase adjustment mechanism capable of transmitting a rotational driving force of the transmission support member to a rotary balance and adjusting a rotational phase of the rotary balance with respect to the main shaft in conjunction with a needle swing of a needle bar;
A rotary balance device for a sewing machine comprising: The phase adjustment mechanism includes:
A first engagement member and a second engagement member that are engaged with each other via a groove cam and a cam portion that engages with the groove cam, and the transmission support member can rotate concentrically with the axis of the main shaft. A first engagement member that is mounted so as to be movable in the axial direction and is rotationally driven by a rotational driving force from the transmission support member; a second engagement member to which a base end portion of the rotary balance is fixed;
A horizontal movement transmission mechanism for transmitting the needle movement horizontal movement of the needle bar base drive shaft of the needle movement mechanism to the first engagement member;
The rotary balance device for a sewing machine according to claim 1, further comprising:   The first engagement member is a first engagement tooth forming member formed with a first helical spline engagement tooth concentric with the axis of the main shaft, and the second engagement member is the first helical spline engagement tooth. The rotary balance device for a sewing machine according to claim 2, wherein the rotary balance device is a second engagement tooth forming member having second helical spline engagement teeth meshed with each other.   The phase adjusting mechanism advances the rotational phase of the rotary balance when the needle bar swings to the right when the thread catching hook rotates counterclockwise as viewed from the operator of the sewing machine, and the needle bar 4. The rotary balance device for a sewing machine according to claim 1, wherein when the needle swings leftward, the rotational phase of the rotary balance is delayed.   The phase adjusting mechanism advances the rotational phase of the rotary balance when the needle bar swings to the left when the thread catching hook rotates clockwise as viewed from the operator of the sewing machine, and the needle bar The rotary balance device for a sewing machine according to any one of claims 1 to 3, wherein the rotational phase of the rotary balance is delayed when the needle is swung to the right. The horizontal movement transmission mechanism includes a link mechanism that slides the first engagement member in the axial direction of the main shaft by a distance corresponding to a phase change amount of the rotary balance by a horizontal movement amount by the needle swing mechanism. The rotary balance device for a sewing machine according to any one of claims 2 to 5,