JP2007029517A - Thread cutting device of eyelet sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the strenuous control of the dispersion of the quantity of the remaining thread after cutting at the time of the completion of the eyelet hole overcasting even when the seam length of an eyelet hole sewing varies. <P>SOLUTION: When an air cylinder for cutting the thread 24 is driven at the time of the completion of the sewing, an upper blade member 21 and a lower blade member 22 are turned in reverse directions by the turning of a first actuation link 30 and a drive link 35, and a situation that a drive shaft 34 of a second actuation link 39 and a third pin 41 and a fourth pin 42 of a second connection link 40 are located on one straight line continues for a prescribed period while the lower blade 22 is turned. At this time, although the second actuation link 39 is turned, only the upper blade 21 is continuously turned in a clockwise direction in the situation that the turning of the lower blade 22 is substantially stopped. Thereby, the bobbin thread and the core thread are cut by only the turning of the upper blade 21 in the situation that the turning of the lower blade 22 is substantially stopped. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thread trimming device for an eyelet sewing machine, in particular, when thread trimming after sewing a seam stitching so that the remaining thread amount after cutting is stable even when the stitch length is different. The present invention relates to an improved thread trimming device.

  Conventionally, in an eyelet sewing machine having a needle bar or looper, a feed base for placing a workpiece to be used for eyelet stitching is provided, and when the eyelet stitching is finished, the inside of the feed base is finished. The equipped thread trimming device cuts the lower thread and the core thread at the same time.

  For example, in a thread trimming device for an eyelet sewing machine described in Patent Document 1, the upper knife and the lower knife are pivotably pivoted by a step screw at a position away from the stitch center line of the right feed plate to the right. On the other hand, a connecting link is connected to the thread trimming drive arm, and one end of the upper knife is connected to the connecting link via the upper knife link, and one end of the lower knife is connected to the lower knife link. It is connected.

  When the cylinder is driven to advance during thread trimming, the thread trimming link arm is rotated and the connecting link moves via the thread trimming driving arm, so that the upper knife and the lower knife simultaneously rotate toward each other. The lower thread and core thread extending from the eyelet seam are cut at the same time by the upper knife and the lower knife at a position near the sewing end position of the eyelet hole stitching.

JP 2001-3218589 A (pages 4-6, FIGS. 1 and 4)

  As described above, in the thread trimming device of the eyelet sewing machine described in Patent Document 1, the upper knife and the lower knife are rotated by a step screw on the right feed plate at a position away from the stitch center line to the right. Since the upper knife and the lower knife are simultaneously pivoted to cut the thread while rotating simultaneously, the cutting trajectory of both the knifes is inclined by a predetermined angle with respect to the center line of the eyelet seam. On a diagonal line.

  That is, when the stitch lengths of the eyelet stitches to be sewn are different, as shown in FIG. 6 according to the embodiment, the cutting position by both the scalpels changes obliquely and linearly as indicated by a one-dot chain line L0. Thus, there is a problem that the cutting position of the thread extending from the stitching end position of the eyelet stitching varies depending on the stitch length difference. That is, as the stitch length is longer, the thread end length after thread cutting varies than when the stitch length is shorter.

  A thread trimming device for an eyelet perforated sewing machine according to claim 1 is provided on a feed base of a feeding device that feeds a workpiece, and an upper blade member and a lower blade member that are rotatably attached to a common vertical shaft member, respectively. The thread extending from the sewing end position of the eyelet stitching formed on the sewing product is cut when the blade portion of the upper blade member and the blade portion of the lower blade member meet in the vicinity of the sewing end position. A thread trimming device for an eyelet perforating sewing machine having a thread trimming operation mechanism that operates a thread trimming operation on an upper blade member and a lower blade member, and an actuator that drives the thread trimming operation mechanism. In the vicinity of the position, one of the upper blade member and the lower blade member is configured to perform the thread trimming operation in a state where the rotation of the blade member is stopped.

  When an eyelet seam is formed on the work to be sewn, and the thread trimming mechanism is driven by the actuator at the end of the seam of the eyelet stitching, the upper and lower blade members are thread trimmed by the thread trimming mechanism. Operate. By the way, at the time of this thread trimming, with one blade member of the upper blade member and the lower blade member stopped to rotate, the thread is cut by the rotation of only the other blade member.

  That is, the cutting trajectory by the upper blade member and the lower blade member is the rotation position of one of the upper blade member and the lower blade member that has stopped rotating, and therefore any of the rotation stops. If the direction of one of the blade members is stopped along the center line of the seam of the eyelet hole, the cutting position relative to the sewing end position is different when the seam length of the eyelet seam is different. Is suppressed as much as possible, and variations in the length of the cut yarn end are suppressed.

  A thread trimming device for an eyelet sewing machine according to claim 2 is provided on a feed base of a feeding device for feeding a workpiece, and an upper blade member and a lower blade member which are rotatably attached to a common vertical shaft member, respectively. The thread extending from the sewing end position of the eyelet stitching formed on the sewing product is cut when the blade portion of the upper blade member and the blade portion of the lower blade member meet in the vicinity of the sewing end position. A thread trimming device for an eyelet perforating sewing machine having a thread trimming operation mechanism that operates a thread trimming operation on an upper blade member and a lower blade member, and an actuator that drives the thread trimming operation mechanism. In the vicinity of the position, one of the upper blade member and the lower blade member is configured to perform the thread trimming operation while returning and rotating from the position where the blade member is rotated to the side closer to the counterpart blade member. .

  When an eyelet seam is formed on the work to be sewn, and the thread trimming mechanism is driven by the actuator at the end of the seam of the eyelet stitching, the upper and lower blade members are thread trimmed by the thread trimming mechanism. Operate. By the way, at the time of this thread trimming, the one blade member of the upper blade member and the lower blade member is returned and rotated from the position where the blade member is rotated to the side closer to the counterpart blade member, while the other blade portion is rotated. The thread is trimmed.

  That is, the cutting trajectory by the upper blade member and the lower blade member is the rotation position of one of the upper blade member and the lower blade member that rotates to return, and therefore the rotation of one blade member. By setting the return point to the middle position between the maximum and minimum lengths within the range of stitch lengths that can be cut, the cut position relative to the sewing end position when the stitch lengths of the eyelet stitches are different Is significantly suppressed, and variations in the length of the cut yarn end are greatly suppressed.

  According to a third aspect of the present invention, the thread trimming device of the eyelet perforated sewing machine according to the first or second aspect is such that the actuator is constituted by one air cylinder.

  According to a fourth aspect of the present invention, there is provided the thread trimming device for the eyelet sewing machine according to the first aspect, wherein the actuator includes a first actuator that operates the upper blade member, and a second actuator that operates the lower blade member independently of the first actuator. And an actuator.

  According to a fifth aspect of the present invention, the thread trimming device for the eyelet perforated sewing machine according to any one of the first to third aspects, wherein the lower blade member constitutes a part of the needle plate when the sewing is performed, and the thread trimmer operating mechanism The thread trimming operation is performed with the blade member stopped rotating.

  The thread trimming device of the eyelet sewing machine according to claim 6 is characterized in that in claim 1 or 2, the thread trimming operation mechanism transmits the driving force of the actuator to the upper blade member and the lower blade member via the link mechanism. It is configured.

  According to a seventh aspect of the present invention, the thread trimming device of the eyelet sewing machine according to the first or second aspect is such that the thread trimming operation mechanism transmits the driving force of the actuator to the upper blade member and the lower blade member via the cam mechanism. It is configured.

  According to the first aspect of the present invention, the eyelet is provided with an upper blade member and a lower blade member, and cuts a thread extending from the stitching end position of the eyelet stitching formed in the sewing product in the vicinity of the stitching end position. The thread trimming device for a boring machine has a thread trimming operation mechanism and an actuator, and the thread trimming mechanism has one of the upper blade member and the lower blade member stopped rotating in the vicinity of the sewing end position. Since the thread trimming operation is performed in this state, if the direction of one of the blade members that stops the rotation at the time of thread cutting is stopped along the center line of the eyelet stitching seam, When the stitch lengths of the eyelet stitches are different, the change in the cutting position with respect to the sewing end position can be suppressed as much as possible, and the variation in the remaining thread amount after cutting can be suppressed.

  According to the second aspect of the present invention, the eyelet is provided with an upper blade member and a lower blade member, and cuts a thread extending from the sewing end position of the eyelet hole stitching formed in the sewing product in the vicinity of the sewing end position. In a thread trimming device for a boring machine, it has a thread trimming operation mechanism and an actuator, and the thread trimming mechanism is in the vicinity of the sewing end position, and one of the upper blade member and the lower blade member is a counterpart blade member. Since the thread trimming operation is performed while returning and rotating from the position that has been rotated to the side closest to the thread, the rotation return point of the one blade member that rotates and returns when the thread is cut can be cut. By setting the middle position between the maximum length and the minimum length in the stitch length range, when the stitch length of the eyelet stitching is different, the change in the cutting position with respect to the stitching end position can be remarkably suppressed. Large variation in yarn remaining after cutting It can be suppressed to.

  According to invention of Claim 3, since the said actuator was comprised by one air cylinder, a thread trimming apparatus can be simplified. In addition, the thread extending from the end of the eyelet stitching can be cut only by driving one air cylinder. Other effects similar to those of the first or second aspect are achieved.

  According to the invention of claim 4, the actuator includes the first actuator that operates the upper blade member and the second actuator that operates the lower blade member independently of the first actuator. The upper and lower blade members can be operated independently by the first and second actuators, and when the stitch lengths of the eyelet stitches are different by combining the operations of the first and second actuators, the sewing end position The cutting position with respect to can always be set at the same position, and variations in the remaining yarn amount after cutting can be reliably eliminated. Other effects similar to those of the first aspect are obtained.

  According to the invention of claim 5, since the lower blade member constitutes a part of the needle plate in the sewing state, and the thread trimming operation mechanism operates to trim the thread with the lower blade member stopped, the needle plate The lower blade member can be configured by effectively utilizing a part of the thread, and thread cutting can be performed by stopping the rotation of the lower blade member. Other effects similar to those of any one of claims 1 to 3 to 4 are achieved.

  According to invention of Claim 6, since the said thread trimming operation mechanism was comprised so that the drive force of an actuator might be transmitted to an upper blade member and a lower blade member via a link mechanism, the structure of a thread trimming operation mechanism is comprised. It can be simplified by the link mechanism. Other effects similar to those of the first or second aspect are achieved.

  According to the invention of claim 7, since the thread trimming operation mechanism is configured to transmit the driving force of the actuator to the upper blade member and the lower blade member via the cam mechanism, the configuration of the thread trimming mechanism is configured. It can be simplified by the cam mechanism. Other effects similar to those of the first or second aspect are achieved.

  The thread trimming device of the eyelet sewing machine of the present embodiment moves the upper blade member and the lower blade member simultaneously in the encounter direction at the end of the sewing of the eyelet stitching while stopping the rotation of the lower blade member. The thread trimmer is activated.

  As shown in FIG. 1, an eyelet sewing machine 1 is used to sew eyelet stitching stitches HN (see FIG. 3) having a flow tacking shape used for denim (jeans), and is a substantially rectangular box having an open top. A bed 2 having a shape, a bed 3 placed so as to be fitted into the bed 2, a pedestal 4 erected from the rear of the bed 3, and the pedestal 4 The arm portion 5 extends forward from the upper portion, and is placed and fixed on a sewing machine table (not shown).

  A needle bar (not shown) provided with a sewing needle (not shown) is provided at the lower end of the arm portion 5 so as to be movable up and down. Although not shown in detail, the rotational force of the main shaft that is rotated by the driving of the sewing machine motor is a cam. It is transmitted to the mechanism and is driven up and down while swinging left and right by a predetermined width. In this case, every time the main shaft rotates twice, the needle bar swings between a left swing position and a right swing position.

  The bed 3 is provided with a looper base (not shown) provided with two loopers (not shown) so as to face the needle bar, and these two loopers are connected to the main shaft via a cam mechanism (not shown). By rotating the needle bar, the needle bar is driven in synchronism with the vertical movement of the needle bar. Further, the needle bar and the looper base are integrally rotated around the vertical axis in a horizontal plane by a rotation mechanism (not shown) including a θ-direction drive motor and a gear mechanism provided in the bed portion 3. It has become.

  The bed 3 is detachably mounted with a knife (not shown) for forming a fixed eyelet located on the rear side of the looper base, and is punched so as to contact and separate from the knife from above. A hammer main body (not shown) is swingably provided. A hammer (not shown) for eyelet holes is detachably attached to the tip of the hammer body, and is driven by a hammer drive mechanism (not shown) made up of an air cylinder or the like provided in the bed 3. A hole is drilled in the work cloth.

  A feed base 7 on which a work cloth is set is provided on the upper surface of the bed 3. The feed table 7 has a thin rectangular box shape as a whole, and a pair of left and right cross plates 8 and 9 are provided on the upper surface of the central portion of the feed table 7 in the left-right direction, as shown in FIG. ing. The right throat plate 10 and the left throat plate 11 are fixed to the middle portions of the cross plates 8 and 9 in the front-rear direction by screws 12, respectively. Further, the substantially front end portions of the cross plates 8 and 9 are covered with a cover plate 13.

  Here, the left and right needle plates 10 and 11 can sew eyelet stitches HN having different lengths of about 8 mm. For example, needle plates 10 and 11 that can sew eyelet stitches HN having a length of 14 mm to 22 mm, and needle plates 10 and 11 that can sew eyelet stitches HN having a length of 22 mm to 30 mm; A plurality of types of throat plates 10, 11 such as throat plates 10, 11 that can sew eyelet seams HN having a length of 34 mm to 42 mm are prepared in advance.

  In the bed portion 3, an X-direction moving mechanism (not shown) that moves the feed base 7 in the X direction (left and right direction) by driving the X direction feed motor, and the Y direction (not shown) by driving the Y direction feed motor. A Y-direction moving mechanism (not shown) is provided for feeding and moving in the front-rear direction. Here, the feed base 7, the X-direction moving mechanism, and the Y-direction moving mechanism constitute a feeding device that feeds the workpiece.

  A pair of left and right cloth presser levers 15 and 16 for holding a workpiece are provided on the upper surface of the feed base 7, and a presser foot (not shown) is attached to the tip of each of the presser foot levers 15 and 16. . These presser foot levers 15 and 16 are driven by an air cylinder (not shown) to be switched between an upper retracted position and a lower pressed position.

Next, the thread trimming device 20 provided inside the feed base 7 for cutting the lower thread and the core thread will be described.
The thread trimmer 20 includes an upper blade member 21 and a lower blade member 22 that are pivotally supported on the upper surface of the right cross plate 8, and a thread trimmer operating mechanism 23 that operates the both blade members 21 and 22 with a thread trimmer. The thread trimming operation mechanism 23 is configured by a thread trimming air cylinder 24 and the like.

  As shown in FIGS. 2 and 3, the lower blade member 22 positioned on the lower side and the upper side positioned on the upper side of the lower blade member 22 on the front side of the right needle plate 10 on the upper surface of the right cross plate 8. The blade member 21 is pivotally supported by a first stage screw 26 so as to be rotatable. An upper blade 21a is formed at the hooked tip portion of the upper blade member 21, and a thread holder 27 for holding a lower thread and a core thread to be cut is fixed. However, the lower blade member 22 constitutes a part of the right throat plate 10 so that the thread cutting position is as close as possible to the sewing end position of the eyelet stitching stitch HN.

  As shown in FIGS. 2 to 4, a thread trimming air cylinder 24 is disposed in the left-right direction at the front end portion inside the feed base 7, and the piston rod 24 a has a substantially U-shape when viewed from the top. The connecting member 28 is fixed. The thread trimming air cylinder 24 receives compressed air from a valve unit (not shown) during thread trimming, and drives the piston rod 24a to advance.

  On the rear side of the connecting member 28, there is provided a thread trimming operation mechanism 23 that operates the upper blade member 21 and the lower blade member 22, and includes a link mechanism. Next, the thread trimming operation mechanism 23 will be described.

  As shown in FIGS. 3 and 4, the bent portion of the substantially actuated first operating link 30 is pivotally supported on the lower surface of the right cross plate 8 by a second stage screw 31 as a pivot point. ing. An upper end portion of a downward support shaft 32 is fixed to the front end portion of the first operation link 30, and a roller member 33 is pivotally attached to the support shaft 32. Immediately behind the first operating link 30, a drive shaft 34 (which corresponds to a common vertical shaft member) is pivotally supported so as to pass through from the lower side of the right cross plate 8 to the upper side thereof. .

  A bent portion of a drive link 35 having a substantially square shape in plan view is fixed to a lower end portion of the drive shaft 34, that is, a lower end portion projecting to the lower side of the right cross plate 8 as a rotation fulcrum. Further, the rear end portion of the first operating link 30 and the right end portion of the first connecting link 36 are connected by a first pin 37, and the left end portion of the first connecting link 36 and the front end portion of the drive link 35 are second. The pins 38 are connected.

  On the other hand, on the upper side of the right cross plate 8, the bent portion of the substantially V-shaped second operation link 39 in plan view is the upper end portion of the drive shaft 34, that is, the upper end portion protruding above the right cross plate 8 as a rotation fulcrum. It is fixed. The distal end portion of the first arm portion 39a of the second operating link 39 and the left end portion of the second connecting link 40 are connected by the third pin 41, and protrudes from the right end portion of the second connecting link 40 and the lower blade member 22. The lower blade connecting portion 22b formed on the second pin 42 is connected by a fourth pin 42.

  Furthermore, the tip end portion of the second arm portion 39b of the second operation link 39 and the front end portion of the third connection link 43 are connected by the fifth pin 44, and the rear end portion of the third connection link 43 and the upper blade member 21 are connected. The upper blade connecting portion 21 b formed in a protruding shape is connected by a sixth pin 45. Here, as shown by a two-dot chain line in FIG. 3, a substantially V-shaped concave portion 8a is formed on the upper surface portion of the right cross plate 8, and the second connecting link 40 and the third connecting link 43 are formed in the concave portion. 8a. Therefore, the second operating link 39, the lower blade member 22, and the upper blade connecting portion 21 b of the upper blade member 21 are disposed so as to contact the upper surface of the right cross plate 8.

  By the way, on the lower side of the right cross plate 8, the rear end portion of the plate member 46 in the front-rear direction is fixed to the drive link 35, and the screws 47 fixed to the front end portion of the plate member 46 and the lower surface of the right cross plate 8. On the other hand, a tension coil spring 48 is hung. Therefore, the first operating link 30 abuts on the standby position regulating screw 49 fixed to the lower surface of the right cross plate 8 through the link mechanism composed of the plurality of links 30, 35, 36, 39, 40, 43. Therefore, it is always elastically biased to the standby position shown in FIG.

  Therefore, as shown in FIG. 3, the lower blade member 22 is located at a standby position that functions as a part of the right needle plate 10, and the upper blade member 21 is at a standby position that is largely open toward the left needle plate 11. positioned. In this state, when the thread trimming air cylinder 24 is driven and the piston rod 24a is driven to advance to the advanced position indicated by a two-dot chain line in FIG. 3, the first operating link 30 is connected to the first operating link 30 via the connecting member 28 in FIG. It rotates counterclockwise to the operation completion position shown in -3.

  By the way, when the blade portion 21a of the upper blade member 21 and the blade portion 22a of the lower blade member 22 meet each other, the lower thread and the core thread extending from the sewing end position are formed at the end of sewing of the eyelet stitching stitch HN. When cutting, as shown in FIGS. 5-2 and 6, the drive shaft 34 of the second operation link 39 and the second connection link 40 are connected to each other, although the second operation link 39 is rotating. The 3 pin 41 and the 4th pin 42 may be located on a straight line.

  In this case, since the third pin 41 moves on an arc centered on the drive shaft 34, the lower blade member 22 does not receive any rotational force from the second connection link 40 at the lower blade connection portion 22b. The rotation of the blade member 22 stops. However, since the third connecting link 43 is pulled forward by the rotation of the second operation link 39 and the upper blade member 21 continues to receive the turning force in the clockwise direction, it continues to rotate toward the lower blade member 22. . Thus, in a state where the lower blade member 22 is substantially stopped from rotating, the lower thread and the core thread are cut by the rotation of only the upper blade member 21.

  That is, as described above, a plurality of types of eyelet seams HN having different lengths of about 8 mm can be sewn by the pair of left and right needle plates 10 and 11 mounted on the left and right cross plates 8 and 9. It is like that. Therefore, when forming the eyelet stitched seam HN having the flow tack-stopped shape shown in FIG. 6, the end of stitching of the eyelet stitched seam HN of the minimum length with respect to the position KC at the top of the eyelet stitched seam HN There is a difference of about 8 mm between the position SC and the sewing end position LC of the maximum length eyelet seam HN.

  In this case, the thread trimming operation mechanism 23 is configured so that the lower blade member 22 substantially stops rotating until the thread trimming is performed at the sewing end position SC that is about 8 mm away from the thread trimming position at the sewing end position LC. ing. Therefore, the cutting trajectory by these two blade members 21 and 22 is, as shown by the solid line L in FIG. 6, the blade portion 22a of the lower blade member 22 in the cut state with respect to the seam center line C of the eyelet seam HN. It is on an inclined straight line determined by the tip. That is, the sewing end position LC and the sewing end position SC that are about 8 mm apart differ from each other by a minute dimension δ (for example, about 0.9 mm) in the left-right direction.

Next, the operation and effect of the thread trimming device 20 configured as described above will be described.
During sewing preparation or during sewing, as shown in FIG. 5-1, the thread trimming air cylinder 24 is not driven, so that the upper blade member 21 and the lower blade member 22 are positioned at the standby positions as described above. is doing. When the thread trimming air cylinder 24 is driven at the end of sewing, as described above, the upper blade member 21 and the lower blade member 22 rotate in directions opposite to each other by the rotation of the first operation link 30 and the drive link 35. During the rotation of the lower blade member 22, the drive shaft 34 of the second operating link 39 and the second connecting link are moved from the cutting state shown in FIG. 5-2 to the cutting state shown in FIG. 5-3. A state in which the forty third pins 41 and the fourth pins 42 are positioned in a straight line continues for a predetermined period.

  At this time, as described above, only the upper blade member 21 is rotated in the clockwise direction in a state where the lower blade member 22 is substantially stopped while the second operation link 39 is rotating. That is, it continues to rotate toward the lower blade member 22. Therefore, in a state where the lower blade member 22 is substantially stopped from rotating, the lower thread and the core thread are cut by the rotation of only the upper blade member 21.

  As described above, the upper blade member 21 and the lower blade member 22, the thread trimming operation mechanism 23, and the thread trimming air cylinder 24 are provided. Since the thread trimming operation is performed in a state where the rotation is substantially stopped, the lower blade member 22 that stops the rotation is stopped so that the direction of the lower blade member 22 is along the seam center line C of the eyelet seam HN. In addition, when the stitch lengths of the eyelet stitching stitches HN are different, the change in the cutting position with respect to the sewing end position can be suppressed as much as possible, and the variation in the remaining thread amount after cutting can be suppressed.

  Further, since the thread trimming operation mechanism 23 is actuated by the thread trimming air cylinder 24, the thread trimming device 20 can be simplified, and only one thread trimming air cylinder 24 is driven. The thread extending from the end of the eyelet stitching can be cut.

  Further, when the lower blade member 22 is in the sewing state, it constitutes a part of the right throat plate 10, and the thread trimming operation mechanism 23 operates when the lower blade member 22 stops rotating. The lower blade member 22 can be configured by effectively utilizing a part, and thread cutting can be performed by stopping the rotation of the lower blade member 22.

  Further, since the thread trimming operation mechanism 23 is configured to transmit the driving force of the thread trimming air cylinder 24 to the upper blade member 21 and the lower blade member 22 through the link mechanism, the configuration of the thread trimming operation mechanism 23 is configured. Can be simplified by the link mechanism.

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

1) Partially changing the above-described thread trimming operation mechanism 23, the thread trimming air cylinder 24 is driven, the upper blade member 21 and the lower blade member 22 are rotated, and the lower blade member 22 is rotated. In the middle, the thread trimming operation mechanism 23A may be configured to return and rotate from the position where the maximum rotation is performed.

  That is, as shown in FIG. 7A, the thread trimming operation mechanism 23A includes a second operation link 39A in which the first arm portion 39a of the above embodiment is elongated by a predetermined dimension and a third connection link 43 that is elongated by a predetermined dimension. The third connection link 43A, and the other links 30, 35, 36, 40 similar to those in the above-described embodiment. Therefore, during sewing preparation when the thread trimming air cylinder 24 is not driven or during sewing, the positional relationship between the first operating link 30, the lower blade member 22, and the upper blade member 21 is shown in FIG. As shown in FIG. 5-1.

  However, when the thread trimming air cylinder 24 is driven at the end of sewing, the upper blade member 21 and the lower blade member 22 are rotated in opposite directions by the rotation of the first operation link 30 and the drive link 35, During the rotation of the lower blade member 22, in the cut state shown in FIG. 7-2, the drive shaft 34 of the second operation link 39A and the third pin 41 and the fourth pin 42 of the second connection link 40 are in a straight line. Further, in the cut state shown in FIG. 7-3, the third pin 41 of the second connecting link 40 further rotates beyond the straight line.

  Therefore, while the second operation link 39A is rotating, the lower blade member 22 returns and rotates from the position where the lower blade member 22 rotates to the side closer to the upper blade member 21, while the upper blade member 21 is rotated. Only keeps rotating clockwise. That is, since the upper blade member 21 rotates so as to follow the lower blade member 22 at a speed faster than the rotational speed at which the lower blade member 22 returns and rotates, the upper blade member 21 and the lower blade member 22 The lower thread and the core thread are cut.

  As described above, the upper blade member 21, the lower blade member 22, the thread trimming operation mechanism 23A, and the thread trimming air cylinder 24 are provided. The thread trimming operation mechanism 23A is located near the sewing end position and the lower blade member 22 is disposed. Since the thread trimming operation is performed while returning and rotating from the position where the upper blade member 21 is rotated to the side approaching the upper blade member 21 as much as possible, the rotation return time point of the lower blade member 22 that is rotated and returned upon thread cutting is determined. By setting the intermediate position between the maximum length and the minimum length in the range of cuttable stitch lengths, the change in the cutting position with respect to the sewing end position when the stitch length of the eyelet stitching hole HN is different Can be remarkably suppressed, and variations in the remaining yarn amount after cutting can be greatly suppressed.

2] A thread trimming mechanism 23B obtained by partially changing the above-described thread trimming mechanism 23 transmits the driving force of the thread trimming air cylinder 24 to the upper blade member 21A and the lower blade member 22A via the cam mechanism. I have to.

  That is, as shown in FIG. 8A, instead of the second operation link 39 used in the thread trimming operation mechanism 23 of the above embodiment, the operation cam 55 is fixed to the drive shaft 34 and the upper blade of the upper blade member 21B. An upper blade cam contact portion 21c is provided in place of the connecting portion 21b, and a thread trimming mechanism 23B is provided in which a lower blade cam contact portion 22c is provided in place of the lower blade connection portion 22b of the lower blade member 22B. .

  However, the upper blade cam contact portion 21 c is biased toward the operation cam 55 by the spring member 56, and the lower blade cam contact portion 22 c is biased toward the operation cam 55 side by the spring member 57. Therefore, during sewing preparation when the thread trimming air cylinder 24 is not driven or during sewing, the positional relationship between the first operating link 30, the upper blade member 21B, and the lower blade member 22B is as shown in FIG. The same as FIG. 5-1.

  However, when the thread trimming air cylinder 24 is driven at the end of sewing, the operation cam 55 is rotated clockwise by the rotation of the first operation link 30 and the drive link 35, and the upper blade member 21B and the lower blade member are rotated. 22B is rotated in a direction opposite to that of the lower blade member 22B. In the middle of the rotation of the lower blade member 22B, the short lower portion of the operating cam 55 is changed from the cutting state shown in FIG. 8-2 to the cutting state shown in FIG. The state where the cam direction of the blade cam portion 55a and the contact surface of the lower blade cam contact portion 22c are orthogonal continues for a predetermined period.

  At this time, only the upper blade member 21B is used for the upper blade of the operation cam 55 in a state where the lower blade member 22B is substantially stopped while the operation cam 55 is rotated in the clockwise direction. The cam portion 55b continues to rotate clockwise, that is, toward the lower blade member 22. Therefore, in a state where the lower blade member 22B is substantially stopped from rotating, the lower thread and the core thread are cut by the rotation of only the upper blade member 21B.

  As described above, the thread trimming operation mechanism 23B is configured to transmit the driving force of the thread trimming air cylinder 24 to the upper blade member 21B and the lower blade member 22B via the cam mechanism. As a result, the configuration of the thread trimming operation mechanism 23B can be simplified by the cam mechanism.

3) Partially changing the above-described thread trimming operation mechanism 23, omitting the thread trimming air cylinder 24, while operating the lower blade member 22 with a dedicated lower blade solenoid 61 (this corresponds to the second actuator). The thread cutting operation mechanism 23C may be configured to operate the upper blade member 21 with a dedicated upper blade solenoid 62 (which corresponds to the first actuator).

  That is, as shown in FIG. 9A, the rear end portion of the fourth connecting link 60 is connected to the lower blade connecting portion 22 b of the lower blade member 22, and the lower blade solenoid 61 is connected to the front end portion of the fourth connecting link 60. The plunger 61a is connected. The rear end portion of the fifth connecting link 62 is connected to the upper blade connecting portion 21 b of the upper blade member 21, and the plunger 63 a of the upper blade solenoid 63 is connected to the front end portion of the fifth connecting link 62.

  Here, the direction of the upper blade solenoid 63 is opposite to the direction of the lower blade solenoid 61. When the lower blade solenoid 61 is driven, the plunger 61a advances backward, and the fourth connecting link 60 moves rearward. However, when the upper blade solenoid 63 is driven, the plunger 63a advances forward, and the fifth connecting link 62 is moved forward.

  During sewing preparation or during sewing, as shown in FIG. 9A, since the upper and lower solenoids 61 and 63 are not driven, the positional relationship between the lower blade member 22 and the upper blade member 21 is as shown in FIG. As shown, it is similar to FIG.

  However, at the end of sewing, as shown in FIG. 9-2, first, when the lower blade solenoid 61 is driven, the fourth connecting link 60 is moved backward by the advancement of the plunger 61a, and the lower blade member 22 is It rotates to the same position as FIG. 5-2 of the said Example. Subsequently, as shown in FIG. 9C, when the upper blade solenoid 63 is driven, the fifth connecting link 62 is moved forward by the advancement of the plunger 63a, and the upper blade member 21 is shown in the above embodiment. Rotate to the same position as 5-3.

  Therefore, as in the above-described embodiment, the direction of the lower blade member 22 that stops turning is stopped so as to be along the seam center line C of the eyelet seam HN, and the seam of the eyelet seam HN. When the lengths are different, a change in the cutting position with respect to the sewing end position can be suppressed as much as possible, and variations in the remaining thread amount after cutting can be suppressed.

4] The thread trimming operation mechanism 23D may be configured to stop at a predetermined position after the upper blade member 21 is first rotated and then the lower blade member 22 is thread-triggered. About other members, it is provided similarly to the said Example. In this case, the lower blade member 22 is driven by a dedicated lower blade solenoid (not shown), and the upper blade member 21 is driven by a dedicated upper blade solenoid (not shown).

  That is, at the end of sewing, as shown in FIG. 10-1, first, when the upper blade solenoid is driven, the upper blade member 21 is moved clockwise to a predetermined position via the fifth connecting link 62 by the advancement of the plunger. It is rotated until. In this case, the direction of the blade portion 21a of the upper blade member 21 is parallel to the stitch center line C of the eyelet stitching stitch HN. Subsequently, as shown in FIG. 10B, the lower blade solenoid is driven, and the lower blade member 22 is rotated counterclockwise via the fourth connection link 60.

  Therefore, the upper blade member 21 is stopped when the direction of the blade portion 21a becomes parallel to the stitch center line C, and the lower thread and the core thread are cut by the rotation of only the lower blade member 22. Is done. In this case, even if the stitch length of the eyelet stitched seam HN is different, the cutting position with respect to the sewing end position does not change, so that the variation in the remaining thread amount after cutting is surely eliminated and suppressed. Can do.

5] The present invention is not limited to the embodiment described above, and those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention. The present invention includes such modifications.

1 is a perspective view of an eyelet-punching sewing machine according to an embodiment of the present invention. It is a top view of a feed stand. It is a top view of a thread trimming device. It is a principal part vertical side view of a feed stand. It is a top view of a thread trimming operation mechanism. FIG. 5 is a diagram corresponding to FIG. 5-1, at the start of thread trimming. FIG. 5 is a view corresponding to FIG. 5-1, at the end of thread trimming. It is explanatory drawing explaining a thread trimming operation | movement. FIG. 5 is a view corresponding to FIG. 5A according to a first modification. It is FIG. 5-2 equivalent figure which concerns on a 1st modification. FIG. 5 is a view corresponding to FIG. 5-3 according to a first modification. FIG. 10 is a view corresponding to FIG. 5A according to a second modification. It is FIG. 5-2 equivalent figure which concerns on a 2nd modification. FIG. 6 is a view corresponding to FIG. 5-3 according to a second modification. FIG. 10 is a view corresponding to FIG. 5A according to a third modified embodiment. It is FIG. 5-2 equivalent figure which concerns on a 3rd modification. It is FIG. 5-3 equivalent figure which concerns on a 3rd modification. It is FIG. 5-2 equivalent figure which concerns on a 4th modification form. It is FIG. 5-3 equivalent figure which concerns on a 4th modification form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eyelet hole sewing machine 7 Feed base 10 Right needle plate 11 Left needle plate 20 Thread trimmer 21 Upper blade member 21B Upper blade member 22 Lower blade member 22B Lower blade member 23 Thread trimming operation mechanism 23A Thread trimming operation mechanism 23B Thread trimming operation Mechanism 23C Thread trimming mechanism 23D Thread trimming mechanism 24 Thread trimming air cylinder 30 First actuating link 34 Drive shaft 35 Drive link 36 First connecting link 39 Second actuating link 40 Second connecting link 43 Third connecting link 55 Actuating Cam 60 Fourth connection link 61 Lower blade solenoid 62 Fifth connection link 63 Upper blade solenoid

Claims (7)

Eyelet hole stitching formed on the sewing product, which is provided on the feed base of the feeding device that feeds the workpiece, and includes an upper blade member and a lower blade member that are rotatably attached to a common vertical shaft member, respectively. In the thread trimming device of the eyelet sewing machine that cuts the thread extending from the sewing end position of the upper blade member and the blade part of the lower blade member in the vicinity of the sewing end position,
A thread trimming operation mechanism for performing a thread trimming operation on the upper blade member and the lower blade member;
An actuator for driving the thread trimming operation mechanism,
The thread trimming operation mechanism is configured to perform a thread trimming operation in a state where one of the upper blade member and the lower blade member stops rotating in the vicinity of the sewing end position.
A thread trimming device for an eyelet sewing machine characterized by that. Eyelet hole stitching formed on the sewing product, which is provided on the feed base of the feeding device that feeds the workpiece, and includes an upper blade member and a lower blade member that are rotatably attached to a common vertical shaft member, respectively. In the thread trimming device of the eyelet sewing machine that cuts the thread extending from the sewing end position of the upper blade member and the blade part of the lower blade member in the vicinity of the sewing end position,
A thread trimming operation mechanism for performing thread trimming operation on the upper blade member and the lower blade member;
An actuator for driving the thread trimming operation mechanism,
The thread trimming operation mechanism is configured to return and rotate from the position where one of the upper blade member and the lower blade member is rotated to the side closer to the counterpart blade member in the vicinity of the sewing end position. Configured to actuate,
A thread trimming device for an eyelet sewing machine characterized by that.   The thread trimming device for eyelet-operated sewing machine according to claim 1 or 2, wherein the actuator is one air cylinder.   2. The eyelet hole according to claim 1, wherein the actuator includes a first actuator that operates the upper blade member and a second actuator that operates the lower blade member independently of the first actuator. Thread trimming device for overlock sewing machine.   5. The lower blade member constitutes a part of a needle plate in a sewing state, and the thread trimming operation mechanism operates to trim a thread while the lower blade member stops rotating. A thread trimming device for an eyelet-punching sewing machine according to any one of the above.   3. The eyelet boring according to claim 1, wherein the thread trimming operation mechanism is configured to transmit the driving force of the actuator to the upper blade member and the lower blade member via a link mechanism. Sewing machine for thread trimming. 3. The eyelet punching mechanism according to claim 1, wherein the thread trimming operation mechanism is configured to transmit a driving force of the actuator to the upper blade member and the lower blade member via a cam mechanism. Sewing machine for thread trimming.

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