JP2005304620A - Button holing sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimize a cloth feed amount irrelevant to the exchange of a feed dog. <P>SOLUTION: This button holing sewing machine is provided with a needle bar 12 retaining a sewing needle 11, a feed means 70 feeding a work cloth, a looper base 20 having loopers 21 and 22 looping a bobbin thread to a needle thread, a needle plate 25 provided on the looper base, a rotational means rotationally turning the needle bar and the looper base in overlocking, a core thread guiding means 40 guiding a core thread from a core thread feed source to a section between needle locations divided in the both sides by the swinging of the sewing needle, and a bobbin thread cutting means 80 cutting the bobbin thread and the core thread when finishing to form a seam. This machine is so constituted that a first core thread feed means feeds, at least, the core thread necessary for a plurality of seams in a button holing sewing from a time of cutting the core thread by finishing the previous sewing till a time before starting the sewing this time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a buttonhole sewing machine that pulls out a core yarn.

  A conventional buttonhole sewing machine has a needle bar that supports a sewing needle that passes an upper thread through a cloth that is a sewing object, a vertical movement mechanism that moves the needle bar up and down, and a swing that swings the needle bar. A mechanism, a looper that catches the upper thread or lower thread, a spreader that expands the loop of the upper thread or lower thread and engages the lower thread or upper thread, and holds the fabric under the sewing needle in the XY direction A feed base that positions the needle thread, guide means that guides the core thread to the needle drop position, a cloth cutter that forms a button hole in the fabric on the feed base, and a thread cutting mechanism that cuts the lower thread and the core thread after the end of sewing And a core yarn feeding means for feeding out the yarn length for consumption at the time of cutting the core yarn from the supply source (for example, see Patent Document 1).

  At the time of sewing, a button hole is formed by a cloth cutter on the fabric set on the feed base, and along the periphery of the button hole by the cooperation of the vertical movement mechanism of the sewing needle and the needle swing mechanism and the feed base. Overlock sewing is performed. At this time, the upper thread and the lower thread are engaged with each other by the cooperation of the looper and the spreader, and are sewn on the fabric. At that time, the core thread is sewn at the same time for sewing.

Furthermore, when the sewing around the button hole is completed, the feed base is returned to the initial position. At that time, the core thread feeding means operates in conjunction with the movement of the feed base in the return direction. The core yarn is fed out by the movement of the feed base.
In other words, in the above-described conventional example, the thread cutting mechanism carries the lower thread and the core thread to the fixed knife as the movable knife folds, and performs cutting by sandwiching the movable knife and the fixed knife. Therefore, in order to prevent tension from being generated when the core thread is conveyed to the fixed knife and adversely affecting the seam, the core thread for the thread length necessary for cutting by the core thread feeding means is cut before the core thread is cut. It is fed out from the supply source to suppress the seam deformation.
JP 7-328251 A

By the way, a thread spool around which the core thread is wound is set as a core thread supply source, and the core thread is successively fed from the thread spool and supplied to the downstream side. Such a thread spool includes a thread spool R1 having a heel T at both ends as shown in FIG. 8A and a thread spool R2 having no heel at both ends as shown in FIG. 8B. .
When the yarn piece R2 having no heel is used, the core yarn is unwound in order from the outside and is smoothly sent to the downstream side. However, when the yarn piece R1 having the heel T is used, the core yarn is unwound. The core yarn may come into contact with the heel T, and an unexpected resistance may be applied to the downstream feeding. In that case, the core thread is sewn with an excessive tension.

FIG. 9A shows a sewing example in the case where the seam is properly formed in the conventional example. As shown in FIG. 9A, the lower thread DT is sewn into the fabric by the upper thread UT so as to surround the button hole in a continuous annular state, and the core thread CT has a button hole outside the lower thread DT. It is sewn into the fabric by the upper thread UT so as to surround it.
If the core yarn is drawn out smoothly, an appropriate seam is formed as shown in FIG. However, when the thread piece R1 described above is used to contact the heel T, tension is generated in the core thread, so that the core thread CT is close to the button hole side as shown in FIG. 9B. And is hidden under the lower thread DT, and presses the lower thread DT, which may damage the annular shape.

As described above, the conventional buttonhole sewing machine has a disadvantage in that it is affected by the sewing quality due to the disturbance with respect to the feeding of the core thread during sewing.
An object of the present invention is to smoothly feed out the core yarn and improve the sewing quality.

  According to the first aspect of the present invention, there is provided a needle bar for holding the sewing needle through which the upper thread is passed and performing needle swinging in a predetermined direction, a feeding means for transferring the work cloth, and a lower thread in cooperation with the sewing needle. A looper base having a looper to be entangled with the upper thread, a needle plate provided on the looper base, a turning means for turning the needle bar and the looper base at the time of overlock sewing, and a sewing needle from the core thread supply source. Core thread guide means for guiding between needle drop positions divided on both sides by needle swinging, lower thread cutting means for cutting the lower thread and the core thread after completion of the formation of a predetermined hole seam, and core thread guide means A first core yarn feeding means that is arranged in the middle of the guided core yarn path and feeds the core yarn from the core yarn supply source, and includes a predetermined thread consisting of an upper thread, a lower thread, and a core thread around the button hole. In a buttonhole sewing machine that forms a boring seam for the first core thread, Ri, at least, a core yarn of a plurality of stitches amount required for the buttonholing sewing, feeds the later core yarn cutting by the previous sewing completed before the sewing start, and employs a configuration that.

In the above-described configuration, the needle bar moves up and down while swinging the work cloth, which is the workpiece to be sewn on the needle plate. On the other hand, the looper captures the upper thread from the sewing needle, forms a looper, ties it to the lower thread, and performs sewing on the work cloth. At that time, the core yarn guide means supplies the core yarn between two needle drop positions by the needle swing, and causes the core yarn to be sewn into the work cloth with the upper thread.
Then, the feeding means transports the fabric along the button hole, and overlock sewing is performed along the button hole. Further, at the end of the button hole, the needle bar and the looper are turned by the turning means, whereby the sewing direction is turned back at the end of the button hole, and overlock sewing is performed along the periphery of the button hole.
Then, when the over stitching around the button hole is finished, the lower thread and the core thread are cut by the lower thread cutting means.

On the other hand, the first core thread paying-out means is from the previous sewing completion (after cutting the lower thread and the core thread) performed before the above-described sewing to the start of the current sewing (start of driving the first stitch). In the meantime, the core threads for a plurality of stitches in the buttonhole sewing are fed out in advance.
As a result, even if resistance force is generated due to some obstruction factor during the sewing of the core yarn during sewing, at least until the core yarns for several stitches that have been drawn out in advance are consumed, Generation of excess tension is suppressed.
It should be noted that the feeding amount of the core yarn may be less than the amount required for sewing one button hole. In other words, it is possible to suppress the generation of excessive tension in the core yarn until at least the amount of feeding is consumed.

  Also, “from the time when the core thread is cut by the completion of the previous sewing to before the start of the sewing” includes the case where the core thread is fed out for the next sewing after the completion of sewing. The case where the core yarn is fed before the power is turned off and the case where the core yarn is fed before the main power is turned on and the sewing is started are also included.

The invention according to claim 2 has the same configuration as that of the invention according to claim 1, and the first core thread feeding means has at least one button hole button before the start of sewing after completion of the previous sewing. A configuration is adopted in which an amount of core yarn required for hole sewing is fed out.
With the above configuration, during sewing, generation of excessive tension is suppressed until over-locking of one button hole is completed.

The invention described in claim 3 has the same configuration as that of the invention described in claim 1, and the first core thread feeding means has a button hole of one button hole before the start of sewing after the completion of the previous sewing. A configuration is adopted in which the total amount of the core yarn required for the overlock sewing and the core yarn required for the core yarn cutting by the lower thread cutting means is fed out.
In the above configuration, the first core yarn feeding means performs the core yarn feeding of the amount required for the boring sewing and the amount required for the cutting at a time. Thereby, generation | occurrence | production of an excess tension is suppressed until the overlock sewing of one button hole is completed, and generation | occurrence | production of the excess tension at the time of core thread cutting | disconnection is also suppressed.

The invention described in claim 4 has the same configuration as that of the invention described in claim 1 or 2, and the first core thread feeding means has a core formed by the lower thread cutting means after the start of sewing and before cutting the core thread. A configuration is adopted in which an amount of core yarn required for yarn cutting is paid out in advance.
In the above configuration, the first core yarn feeding means performs the second core yarn feeding from the start of sewing to the time of cutting the core yarn. The second core yarn feed is a feed required for cutting the core yarn, and the core yarn on the fabric side is restrained from being tensioned in advance before cutting. It is more desirable that the second core thread feeding is performed until the formation of the seam in the buttonhole overhang is completed and the core thread cutting is started.

  The invention according to claim 5 has the same configuration as that of the invention according to claim 1 or 2, and is located in the middle of the path of the core yarn guided by the core yarn guiding means and downstream from the first core yarn feeding means. A second core yarn feeding means that is arranged and feeds an amount of core yarn required for cutting the core yarn by the lower thread cutting means from the core yarn supply source; A configuration is adopted in which an amount of core yarn required for cutting is fed in advance after the start of sewing and before cutting of the core yarn.

In the above configuration, the second core yarn feeding means feeds the core yarn corresponding to a part or all of the amount consumed when cutting the core yarn after the start of sewing and before cutting the core yarn. By the core yarn feeding by the second core yarn feeding means, the core yarn on the fabric side is restrained from receiving tension by being drawn in advance before cutting.
The feeding by the second core yarn feeding means is more preferably performed from the completion of sewing in this sewing to the cutting. This is because the influence on the fed core yarn in the first core yarn feeding means can be avoided.

The invention described in claim 6 has the same configuration as that of the invention described in any one of claims 1 to 5, and the first core yarn feeding means is driven by the driving means from the core yarn supply source. A core yarn feeding member that feeds the core yarn is provided, and a core yarn holding mechanism is provided that prevents the core yarn from being drawn from the downstream side of the core yarn feeding member when the core yarn feeding member is driven.
In the above-described configuration, when the core yarn is fed by the first core yarn feeding means, the core yarn holding mechanism is configured to feed the core yarn downstream (work cloth side) from the core yarn feeding member of the first core yarn feeding means. Therefore, the core yarn is fed out exclusively from the supply source side of the core yarn. This avoids generation of excessive tension on the downstream side when the core yarn is fed.

  According to the first aspect of the present invention, since the core thread for a plurality of stitches in the buttonhole sewing is fed by the first core thread feeding means before the start of the sewing after the completion of the previous sewing, Even if there is a factor that hinders smooth feeding of the thread, for example, contact between the thread spool and the core thread, or rotation failure of the thread spool, the advance feed is consumed, so at least the advance feed is consumed. Until then, the influence of the excessive tension of the core yarn can be reduced, and the core yarn is sewn at a regular position, and the shape of other yarns is not destroyed, and the sewing quality can be improved.

  According to the second aspect of the present invention, since the core thread for at least one button hole is pre-drawn, generation of excessive tension of the core thread is suppressed for the entire sewing in one button hole, and further sewing quality is improved. Can be improved.

  In the invention according to claim 3, since the core thread is fed out once for the amount required for bobbin stitching and for the amount necessary for cutting before the start of the sewing after the previous sewing is completed, It is possible to suppress the generation of excessive tension until the end of sewing and to suppress generation of excessive tension when cutting the core yarn. Therefore, the influence on the seam by the pulling of the core yarn is further reduced, and the sewing quality can be further improved.

  In the invention according to claim 4, since the second core yarn is fed out in an amount required for the core yarn cutting by the lower thread cutting means after the start of sewing and before the core yarn is cut, the core yarn on the fabric side is cut at the time of cutting. The tension is suppressed, the influence on the seam by the pulling of the core yarn is reduced, and the sewing quality can be improved.

  In the fifth aspect of the present invention, the second core thread feeding means performs the core thread feeding of the amount required for the core thread cutting by the lower thread cutting means after the start of sewing and before the core thread cutting. The core yarn on the fabric side is restrained from being tensioned, the influence on the seam by the pulling of the core yarn is reduced, and the sewing quality can be improved.

  The invention according to claim 6 is provided with a core yarn holding mechanism that prevents the core yarn from being drawn from the downstream side when the core yarn feeding member of the first core yarn feeding means is driven. It is possible to avoid the generation of excessive tension on the arm. Therefore, for example, in the case where the holding means for holding the downstream end portion of the core yarn is provided at the time of non-sewing, it is possible to prevent the falling from the holding means.

(Overall configuration of the embodiment)
A buttonhole sewing machine 10 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side view in which a buttonhole sewing machine 10 is partially cut away. As shown in FIG. 1, the buttonhole sewing machine 10 includes a bed portion 2a that is located at the lower part of the entire sewing machine and has a substantially rectangular box shape, and a vertical body portion 2b that is provided at one end of the bed portion 2a. The sewing machine frame 2 includes an arm portion 2c that extends from the vertical body portion 2b in the same direction as the bed portion 2a. In the following description, the direction in which the vertical body portion 2b is erected is the Z-axis direction, the longitudinal direction of the bed portion 2a and the arm portion 2c is the Y-axis direction, and the Y-axis direction is perpendicular to the Z-axis direction. The direction orthogonal to both the Z-axis directions is taken as the X-axis direction.

  The buttonhole sewing machine 10 includes a needle bar 12 that holds a sewing needle 11 through which an upper thread is passed, a vertical movement mechanism (not shown) that moves the needle bar 12 up and down, and a needle bar 12 that swings (not shown). A swing mechanism, loopers 21 and 22 for capturing the upper thread, a spreader (not shown) for expanding the upper thread and lower thread loops to engage with the upper thread and the lower thread, and the needle plate 25 are held at the upper part thereof. The looper base 20, the needle bar 12, the vertical movement mechanism and the turning means (not shown) for turning the looper base 20 during overlock sewing, and the work cloth C are placed and held by the cloth base 71 and moved from the sewing position. A cloth holding mechanism 70 as a feeding means, a core thread guide means 40 for guiding the core thread CT between needle drop positions divided on both sides by a needle swing of the sewing needle 11 from a core thread supply source (not shown), and an upper part after sewing is completed. Cut the thread (not shown) A thread cutting means, a lower thread cutting means 80 for cutting the lower thread and the core thread CT after the end of the formation of a predetermined hole stitch, and a core thread CT routed by the core thread guiding means. The first and second core yarn feeding means 50 and 60 for pulling out the core yarn CT from the core yarn supply source, and the core yarn holding for preventing the core yarn CT from being drawn from the downstream side of the first core yarn guide means 50. A mechanism 30, lower thread holding means 14 that holds the end of the lower thread DT after cutting and the end of the core thread CT, and an operation control means (not shown) that controls the operation of each of the above-described configurations are provided. .

(Needle bar, vertical movement mechanism and swing mechanism)
The needle bar 12 is provided along the Z-axis direction at one end of the arm portion 2c, and moves up and down while swinging the sewing needle at the tip along the X-axis direction by a well-known vertical movement mechanism and swing mechanism during sewing. I do. Both the vertical movement mechanism and the swing mechanism are given drive force for their vertical movement and swing from an upper shaft driven by a sewing machine motor (not shown). Further, the vertical movement and the swinging are performed in synchronism with each other, and thereby, over-the-counter sewing is performed while swinging the work cloth C with a certain width in the X-axis direction.

  Further, the needle bar 12, the vertical movement mechanism, and the swing mechanism are supported by the sewing machine frame 2 so as to be rotatable about the Z-axis direction. The needle bar 12, the vertical movement mechanism, and the swinging mechanism are given rotational force by the turning means in synchronism with a looper base 20 (to be described later) via the timing belt 13 during sewing. That is, by this turning means, it is possible to perform overlock sewing along the arc shape of the water drop shape portion of the eyelet hole which is the button hole.

(Cloth holding mechanism)
FIG. 2 shows a view of the bed 2a as viewed from above. As shown in FIGS. 1 and 2, the cloth holding mechanism 70 includes a cloth base 71 provided on the upper surface of the head portion 2 a on which the work cloth C is placed, and an arm 72 connected to the cloth base 71. A cloth presser 73 that presses the work cloth C placed on the base 71 from above and holds it with a receiving plate 74 provided on the cloth base 71, and a cloth base 71 provided in the bed portion 2a. Drive means (not shown) that horizontally moves in the axial direction and the Y-axis direction. The cloth base 71 is driven by a driving means, and the work cloth C placed on the upper surface is sewn at a position directly above the needle plate 25 and a retracted position away from directly above the needle plate 25 (the position in FIG. 2). ) Is moved horizontally. That is, at the time of sewing, the cloth bed 71 is set at the sewing position, and is moved to the retracted position when the lower thread and the core thread CT are cut after the sewing.
Further, the cloth base 71 is formed with a split portion 71a along the Y-axis direction in the intermediate portion in the X-axis direction, and needle dropping is performed on the split portion 71a during sewing. In other words, the work cloth C set on the cloth base 71 is sewn within the range of the divided portion 71a.

The drive means is, for example, a servo motor or a stepping motor whose drive amount can be controlled, and this enables cloth feed during sewing via the cloth base 71.
The cloth presser 73 can be switched between a cloth press position that is pressed against the cloth base 71 by an actuator (not shown) and a release position that is separated from the cloth base 71.

(Looper base)
The looper base 20 is supported by the sewing machine frame 2 so as to be rotatable around the Z-axis direction at a position below the needle bar 12 of the bed portion 2a. The looper base 20 includes a main body portion 26 that supports various configurations described later, and a rotating shaft portion 27 that is fixedly mounted in a state of extending from the lower portion of the main body portion 26.

  The looper base 20 is supported by the sewing machine frame in the bed portion 2a so as to be rotatable about the axis of the rotation shaft portion 27 in a state where the rotation shaft portion 27 is along the Z-axis direction. The rotation shaft portion 27 and the needle bar 12 described above are arranged so that the central axes of the needle bar 12 are coaxial when the needle bar 12 is not swinging.

  Here, the rotation shaft portion 27 is provided with a driven pulley 27a, and a rotation driving force of the looper base 20 is applied by a turning means via a timing belt (not shown). Here, the turning means includes a stepping motor which is a driving source for the rotational drive of the looper base 20, and this stepping motor also rotationally drives the needle bar 12, the vertical movement mechanism and the swing mechanism described above. Do. Such a stepping motor synchronizes the looper base 20, the needle bar 12, the vertical movement mechanism, and the swing mechanism and rotates them at the same rotational speed.

  Further, the rotation shaft portion 27 is a cylindrical body, and a cylindrical looper drive shaft 28 is inserted and installed inside thereof, and a spreader drive shaft 29 is inserted and installed inside the looper drive shaft 28. The looper drive shaft 28 and the spreader drive shaft 29 are both concentric with the rotation shaft portion 27 and are supported in a state of being individually rotatable with respect to the rotation shaft portion 27. The looper drive shaft 28 and the spreader drive shaft 29 are each input at the lower end portion by a lower shaft that rotates in synchronization with the above-described upper shaft, while at the upper end portion by a cam mechanism (not shown). A swing driving force is transmitted to the loopers 21 and 22 and the spreader. That is, by this, the loopers 21 and 22 and the spreader are driven to swing in synchronization with the vertical movement cycle of the needle bar 12 with different phases, and loop formation and enlargement for the upper thread or lower thread are executed. .

  The spreader drive shaft 29 is also a cylindrical body, and has a function of guiding the lower thread fed from the lower thread supply source through the inside thereof. The spreader drive shaft 29 guides the lower thread to the loopers 21 and 22 and the spreader side.

A needle plate 25 is provided at the upper end of the looper base 20. The needle plate 25 rotates with the looper base 20, and the loopers 21 and 22 and the spreader are arranged so as to swing under the needle plate 25. A needle hole 25 a is formed in the center of the needle plate 25. The sewing needle 11 is inserted into the needle hole 25a, and the loop of the upper thread is supplied to the lower side of the needle plate 25, and the sewing is performed by being entangled with the lower thread by the predetermined swinging operation of the loopers 21, 21 and the spreader. . The needle hole 25a is formed in a long hole shape along the swinging direction of the needle bar 12. Further, since sewing is performed through the needle hole 25a, the lower thread passes through the needle hole 25a and is sewn to the work cloth.
At this time, the core thread CT is also passed through the core thread threading hole 25b (see FIG. 7) provided penetrating from the side surface of the needle plate 25 to the needle hole 25a. And is sewn to the work cloth by the upper thread.

Furthermore, the upper surface of the needle plate 25 is composed of two flat portions that are parallel to the XY plane and provided with a height difference. This is a structure for separating and cutting the lower thread and the core thread CT individually after the core thread CT is fed from the needle hole 25a together with the lower thread and the hole sewing is performed. In this way, the core yarn CT and the lower yarn are individually divided and cut in order to hold the yarn end portions individually after cutting.
In order to perform such sorting, a core thread passage hole 25b is formed along the boundary between the high place plane 25c (see FIG. 7) and the low place plane 25d (see FIG. 7) of the needle plate 25. The needle hole 25 is formed on both sides of the high place plane 25c and the low place plane 25d, but the hole width is formed wider in the region of the needle hole 25a on the low place plane 25d side.
With the above structure, it is possible to distribute the core thread CT and the lower thread into the high place plane 25c and the low place plane 25d by rotating the needle plate 25 around the Z axis. The operation will be described later.

(Lower thread cutting means and lower thread holding means)
As shown in FIG. 2, the lower thread cutting means 80 includes a movable knife 81 that rotates about the Z-axis direction on the upper surface of the bed portion 2 a, and a movable knife 81 that is positioned at the rotation destination of the movable knife 81. And a fixed knife 82 that slidably contacts and cuts the lower thread and the core thread CT from the loopers 21 and 22 to the work cloth C.
The movable knife 81 has a base end portion rotatably supported on the bed portion 2a, and the rotating end portion is formed in a trifurcated shape as viewed from the Y-axis direction. This is because the lower thread and the core thread CT are arranged on the needle plate 25 with a height difference at the time of cutting, so that the lower thread and the core thread CT can be captured at each branch portion of the trident tip. It has a structure that can be done.
The fixed knife 82 is arranged so as to be able to cut the lower thread and the core thread CT by slidingly contacting the outer side of the rotating movable knife 81 in the rotation radius direction.

The lower thread holding means 14 is positioned ahead of the movable knife 81 in the rotational direction, and the lower thread and the core thread CT captured by the movable knife 81 are delivered and held before each cutting.
The lower thread holding means 14 is provided with two thread holding parts with a difference in height, and holds the lower thread and the core thread CT in each thread holding part.

(Core yarn guiding means)
The core yarn guide means 40 is provided near the upper portion of the vertical body portion 2b, and receives the core yarn CT fed from a yarn stand portion (not shown) as a core yarn supply source that holds a yarn spool around which the core yarn CT is wound. , And supplied between the needle drop positions divided on both sides by the swinging of the work cloth C on the cloth base 71.
The core yarn guiding means 40 includes a guide member 41 that guides the core yarn CT fed from the yarn stand portion from the upper surface to the side surface of the vertical body portion 2b, and the core yarn CT guided by the guide member 41. A guide tube 42 is provided to guide from the base of 2b to the vicinity of the looper base 20 in the bed portion 2a. Strictly speaking, the core thread passage hole 25 b of the needle plate 25 described above also constitutes a part of the core thread guide means 40.

The guide member 41 is a bracket provided with a through hole through which the core yarn CT is inserted, and is fixedly mounted on the side surface of the vertical body portion 2b.
The guide tube 42 is a tubular body having one end opened upward from the vicinity of the vertical body 2b on the upper surface of the bed 2a and the other end opened near the looper base 20 in the bed 2a. The guide tube 42 guides the core thread CT through the inside thereof.

(First core yarn feeding means)
FIG. 3 is a plan view showing the upper surface of the vertical body portion 2b of the sewing machine frame 2, and FIG. 4 is a side view of the first core yarn feeding means 50. As shown in FIG.
As shown in FIGS. 3 and 4, the first core yarn feeding means 50 is provided on the upper surface of the sewing machine frame 2 at a position closer to the core yarn supply source than the guide member 41, and starts sewing. The core yarn CT corresponding to the length required for one button hole in advance before the time is used to advance in advance from the core yarn supply source.
As shown in FIGS. 1, 3, and 4, the first core yarn feeding means 50 includes a support plate 51 that is fixedly mounted on the upper surface of the longitudinal body and a pair of yarns that are mounted to face each other on the support plate 51. From the threading member 52, a feeding member 53 having an insertion hole into which the core thread CT guided between the threading members 52 is inserted, and a non-feeding position between the pair of threading members 52 and the unfeeding position. An air cylinder 54 is provided as drive means for switching the position by moving the feeding member 53 between the separated feeding positions.

The support plate 51 is fixedly mounted on the upper surface of the vertical body portion 2b with its flat plate face along the XY plane.
The pair of threading members 52 are installed upright on the upper surface of the support plate 51 with their flat surfaces facing each other close to each other, and threading holes 52a are formed through the flat surfaces at positions corresponding to each other. ing.

The feeding member 53 is supported by the tip of a plunger 55 that moves the air cylinder 54 fixedly mounted on the upper surface of the support plate 51, and the feeding member 53 in the supported state corresponds to each threading member 52. A flat plate portion parallel to the flat plate surface is provided. A threading hole 53 a through which the core thread CT inserted through the threading hole 52 a of each threading member 52 is inserted between the threading members 52 is formed through the flat plate portion of the feeding member 53.
When the plunger 55 of the air cylinder 54 is retracted (non-projecting state), the threading hole 53a of the feeding member 53 and the threading hole 52a of the two threading members 52 are on one straight line along the Y-axis direction. The plunger 55 is supported so as to be lined up along the axis, and when the plunger 55 moves forward, the core thread CT is fed out between the threading members 52 according to the amount of forward movement.

The air cylinder 54 is connected to an electromagnetic valve 56 whose opening / closing operation is controlled by an operation control means of the buttonhole sewing machine 10 (not shown). The air cylinder 54 is driven by the control of the electromagnetic valve 56 to move the plunger 55 in a certain backward direction. It is possible to switch between a state that is a position (the position of the solid line in FIG. 3) and a state that is a certain forward position (the position of the two-dot chain line in FIG. 3).
As described above, since the feed amount of the core yarn CT is determined by the advance position of the plunger 55, a stopper for determining the advance position of the plunger 55 or the feed member 53 may be provided in the middle of the advance path. . In addition, such a stopper may be capable of adjusting the forward movement position so that the movement can be adjusted along the X-axis direction.

(Core thread holding mechanism)
The core yarn holding mechanism 30 is disposed downstream of the first core yarn feeding means 50 and upstream of the guide member 41 and the second core yarn feeding means 60 in the core yarn path.
The core yarn holding mechanism 30 is provided on the support plate 51 on the downstream side of each threading member 52 and prevents the passage of the core yarn CT. And a release arm 39 for releasing the holding state.

  The thread tension device 31 includes a pair of thread tension trays 32 that sandwich the core thread CT, a pressing spring 33 that presses the thread tension trays 32 together, an adjustment knob 34 that adjusts the pressing force to the thread tension tray 32, A release pin 35 that releases the pressing state of the pressing spring 33, and a support shaft 36 that supports each thread tension plate 32, the pressing spring 33, and the adjustment knob 34 are provided.

The base end portion of the support shaft 36 is bent and supported at one end portion of the support plate 51 and is fixedly supported by an upright portion raised along the YZ plane, and maintains a state along the X-axis direction. ing.
The two thread tension plates 32 are supported so as to be movable along the X-axis direction by inserting a support shaft 36 through the central through hole. Further, the two thread tension plates 32 are restricted from further movement along the X-axis direction up to a certain position in the vicinity of the base end portion of the support shaft 36.
One end of the pressing spring 33 is in contact with one thread tension tray 32 and presses the two thread tension trays 32 toward the restriction position along the X-axis direction. With this pressing force, the core yarn CT passed between the two thread tension plates 32 is clamped, and the feeding of the core yarn CT from the downstream side is stopped.
The adjustment knob 34 is screwed to and supported by the tip end portion of the support shaft and is in contact with the other end portion of the pressing spring 33. Therefore, by rotating the adjustment knob 34, the adjustment knob 34 moves along the X-axis direction, and the amount of expansion and contraction of the pressing spring 33 can be adjusted.
The release pin 35 is provided through the inside of the support shaft 36 and is supported by the support shaft 36 so as to be movable in the X-axis direction. One end portion of the release pin 35 protrudes from the base end portion of the support shaft 36, and the other end portion is engaged with one end portion of the pressing spring 33. Therefore, it is possible to release the pressing state of each thread tension tray 32 by pushing back one end of the release pin 35 to push back the pressing spring 33.

FIG. 5 is a partially enlarged view showing an engaged state between the feeding member of the first core yarn feeding means 50 and the release arm 39.
As shown in FIG. 3, the release arm 39 is swingably supported on the upper surface of the support plate 51 by a support shaft pin 38 in the middle in the longitudinal direction.
One end portion of the release arm 39 is in contact with the release pin 35 of the thread tension device 31 so as to be able to be pushed in, and the other end portion is moved backward with respect to the feed member 53 in the retracted position. In contact with the downstream side in the direction.

That is, the other end of the release arm 39 is pressed in the backward movement direction when the feeding member 53 is in the backward position, and the other end of the release arm 39 is swung around the support shaft pin 38. The release pin 35 of the thread tension device 31 is pushed in on the end side. Then, when the feeding member 53 moves forward, the other end portion of the release arm 39 is released as shown in FIG. 5, and the pressing state of the release pin 35 at the one end portion is also released.
As a result, when the core yarn CT is not delivered by the first core yarn delivery means 50, the core yarn holding mechanism 30 is in a state of not restricting the passage of the core yarn CT, and the core yarn CT is delivered by the first core yarn delivery means 50. Sometimes the core yarn holding mechanism 30 stops the passage of the core yarn CT. For this reason, the first core yarn feeding means 50 can perform the core yarn feeding only from the core yarn supply source side which is the upstream side, without performing the core yarn feeding from the downstream side.

(Second core yarn feeding means)
FIG. 6 is an enlarged view of a main part when the second core yarn feeding means 60 is viewed from the front side (right side in FIG. 1).
As shown in FIGS. 1 and 6, the second core yarn feeding means 60 is a side surface of the longitudinal body portion 2 b and is further downstream than the first core yarn feeding means 50 and the guide member 41 in the core yarn supply direction. It is provided and used to feed out the core yarn CT for the length necessary for the backward movement of the work cloth and the cutting operation of the core yarn CT that is performed after all needle stitches of overlock stitching in one button hole are completed. Is done.
As shown in FIGS. 1 and 6, the second core yarn feeding means 60 is located on the side surface of the longitudinal body 2b and between the guide member 41 and the guide tube 42 of the core yarn guiding means 40 described above. A threading member 61 fixed to the threading member 61, a feeding member 62 supported on the front surface of the sewing machine body 2b on the downstream side of the threading member 61 in the core yarn supplying direction, and swinging with respect to the feeding member 62 And an air cylinder 63 for applying a driving force.

The threading member 61 has a flat portion that is erected perpendicularly to the side surface of the longitudinal body 2b, and a threading hole is formed through which the core thread CT is inserted from the guide member 41 to the guide tube 42. ing.
The feeding member 62 is formed in a bent shape and is pivotally supported by a supporting shaft along the Y-axis direction in front of the vertical body portion 2b at the bent portion. Then, one end of the feeding member 62 has a flat portion facing the flat portion of the threading member 61 at a predetermined swing angle, and a threading hole through which the core yarn CT is inserted into the flat portion of the feeding member 62. Is formed.
Further, the other end portion of the feeding member 62 is connected to the plunger 64 of the air cylinder 63, and in a state where the plunger 64 is retracted (non-projecting state),
The threading hole of the threading member 61 is set so that the threading hole of the threading member 61 and the threading hole of the feeding member 62 are closest to each other, and the threading hole of the feeding member 62 is moved forward by the plunger 64 moving forward. And the guide tube 42 are set apart from each other.

The air cylinder 63 is connected to an electromagnetic valve (not shown) whose opening / closing operation is controlled by an operation control means of the buttonhole sewing machine 10 (not shown), and is driven by the control of the electromagnetic valve to keep the plunger 64 constant. It is possible to switch between a state where the rearward position (the position indicated by the solid line in FIG. 6) becomes a predetermined forward position (the position indicated by the two-dot chain line in FIG. 6).
As described above, since the feed amount of the core yarn CT is determined by the advance position of the plunger 64, a stopper for determining the advance position of the plunger 64 or the swing angle of the feed member 62 is provided in the middle of any of the paths. It may be provided. Further, such a stopper may be capable of adjusting the amount of feeding as the movement of the stopper 64 can be adjusted along the direction of movement of the plunger 64 or the direction of rotation of the feeding member 62.

(Operation of buttonhole sewing machine)
A sewing operation in accordance with control by an operation control means (not shown) of the buttonhole sewing machine 10 having the above-described configuration will be described with reference to FIGS. FIG. 7 is an operation explanatory view showing the change in the direction of the needle plate 25 from the start to the end of sewing in order.
The operation control means controls the operation of each component described above at a timing described later in accordance with a ROM storing various control programs for executing the operation control of the buttonhole sewing machine 10 described later and various defaults required for sewing. The system is mainly composed of a CPU to be performed and a RAM which is a work area for operation control processing by the CPU, and each configuration to be controlled is connected to the CPU via an interface.

  First, at the time after the completion of the previous sewing of the other eyelet hole, the solenoid valve 56 of the air cylinder 54 of the first core thread feeding means 50 is controlled by the operation control means, and the plunger 53 is moved to the advance position. . Therefore, the core yarn CT is in a state where the core yarn has been fed out for the length required for the sewing of the present eyelet hole stitch. Since the plunger 53 is moving forward, the release arm 39 is in a state of not pressing the release pin 35 of the thread tension device 31 and restricts the back flow of the core yarn CT from the downstream side of the thread tension device 31. Is in a state.

Then, the work cloth C is set on the cloth base 71 and held by the cloth presser 73. At this stage, the solenoid valve 56 of the air cylinder 54 is controlled by the operation control means, and the plunger 53 is moved to the retracted position. As a result, the core yarn CT is secured in the first core yarn feeding means 50 by the length that has been previously drawn. Further, the other end portion of the release arm 39 is pressed by the retraction of the feeding member 53, and further, one end portion presses the release pin 35 of the thread tension device 31, and the core yarn CT is switched from the stopped state to the passable state.
Then, the cloth base 71 is moved, and the button hole forming portion of the work cloth C is moved to the sewing position between the needle plate 25 and the needle bar 12. At this time, the needle plate 25 is in a state in which the circular portion is directed in the sewing progressing direction (FIG. 7A). That is, the sewing is performed so that the seam is formed toward the right side in FIG.

First, sewing is performed along the straight portion of the eyelet hole. That is, on one side of the straight portion of the eyelet hole, the needle bar 12 moves up and down while swinging. As a result, the upper thread is captured by the loopers 21 and 22 below the work cloth, the loops are further expanded by the spreaders, and the upper thread or the lower thread DT is inserted into the upper thread loop or the lower thread loop. As a result, the upper thread and the lower thread DT engage with each other and repeat this to perform overlock sewing.
Further, the core thread CT is supplied from the core thread payout hole 25b of the needle plate 25 between the needle drop positions separated on both sides in the X-axis direction by needle swinging, and is sewn into the work cloth C by the upper thread.

Then, when the sewing on one side of the linear portion of the eyelet hole is finished and the process proceeds to the sewing of the arc-shaped portion, the looper base 20 and the needle bar 12 start to rotate in the clockwise direction according to the arc shape. FIG. 7B shows the direction of the needle plate 25 at the apex position of the arcuate portion.
Then, when the sewing progresses and the circular hole portion is finished, the direction of the needle plate 25 is just reversed (FIG. 7C). As described above, the looper base 20 and the needle bar 12 are rotated, whereby the needle bar 12 is oscillated radially, and the stitches of the upper thread are also formed radially.

Then, when the sewing of the other side of the straight portion of the eyelet hole is completed with the needle plate 25 in the inverted state, all of the core yarn of the length previously fed by the first core yarn feeding means 50 is consumed. It will be.
Then, the solenoid valve of the second core yarn feeding means 60 is controlled so that the air cylinder 63 is switched to the operating state, and the core yarn CT is fed out. At this time, the length of the core yarn CT fed from the core yarn supply source side by the second core yarn feeding means 60 is equal to the length drawn from the needle hole 25 when the cloth base 71 moves to the retracted position later ( It is set to be substantially the same as or slightly shorter than the sum of the movement distance of the cloth base 71 and the amount consumed when the movable knife 81 of the lower thread cutting means 80 then cuts the core thread CT. .
Then, the cloth base 71 moves to the retracted position side (left side in FIGS. 2 and 7). Then, the upper thread cutting means (not shown) is operated to cut the upper thread.

  Thereafter, the cloth base 71 is moved greatly to the retracted position, and as shown in FIGS. 2 and 7D, the lower thread DT is pulled out from the needle hole 25a. Further, the needle plate 25 is further rotated in the clockwise direction and is in a state of being somewhat inclined. At this time, since the core thread payout hole 25b is provided in the needle plate 25, when the needle plate 25 faces in an oblique direction and each thread is pulled out by the movement of the cloth base 71, the respective positions are shifted. The core yarn CT is positioned on the high plane on the upper surface of the needle plate 25, and the lower thread D is positioned on the low plane. This sort of distribution is caused by the shape of the needle hole 25a, the orientation of the needle plate 25, the boundary position between the high place plane and the low place plane, and the position setting of the core thread feeding hole 25b.

  The lower thread cutting means 80 is driven in the above state. That is, the movable knife 81 rotates, and the tensioned lower thread DT and the core thread CT are separately captured and drawn toward the fixed knife 82, and the lower thread DT and the core thread CT are respectively pulled by the lower thread. The yarn is transferred to the holding means 14 and held separately, and each thread is cut by sliding with the fixed knife 82. At this time, when the core yarn CT is cut, the portion of the core yarn CT fed out by the second core yarn feeding means 60 is consumed.

Then, after the core yarn is cut, the operation of the electromagnetic valve 56 is controlled by the operation control means, and the air cylinder 54 of the first core yarn feeding means 50 moves the plunger 55 forward. At this time, since the release arm 39 is released from the feeding member 53 and the release pin 35 of the thread tension device 31 is also released, the thread tension device 31 holds the core yarn and stops passage. Therefore, the first core yarn feeding means 50 does not feed the core yarn from the downstream side of the thread tension device 31, and feeds the core yarn from the core yarn supply source side.
The feeding operation secures the core yarn for the length required for the next buttonhole sewing.
Thus, a series of sewing operations are all finished. Since the lower thread DT and the core thread CT are separately held by the lower thread holding means 14, it is possible to resume the next sewing from the holding end.

(Effect of embodiment)
The buttonhole sewing machine 10 is sewn by the first core thread feeding means 50 so that the core threads CT for all the stitches required for one buttonhole in the buttonhole sewing are fed in advance when the previous sewing is completed. Factors that hinder the smooth feeding of the core yarn CT at the time, for example, even if contact between the thread spools and the core yarn occurs, the pre-drawing amount is consumed, so that excessive tension of the core yarn CT is generated. The core thread CT can be sewn at a regular position and the shape of other threads is not destroyed, and the sewing quality can be improved.

Further, the buttonhole sewing machine 10 has a core yarn holding mechanism 30 that prevents the core yarn from being drawn out from the downstream side of the core yarn feeding member 53 when the core yarn feeding member 53 of the first core yarn feeding means 50 is driven. Therefore, it is possible to avoid the generation of excessive tension on the downstream side when the core yarn is fed. Therefore, for example, in the case where the end portion of the core yarn is held at the time of cutting by the lower yarn holding means 14, it is possible to prevent the core yarn CT from dropping off from the lower yarn holding means 14.
Further, although not performed by the buttonhole sewing machine 10, for example, even when the second core yarn feeding means 60 is advanced prior to the first core yarn feeding means 50, It becomes possible to maintain the core yarn fed by the second core yarn feeding means 60 without affecting the secured supply amount of the core yarn, and sufficiently maintain the effect of suppressing the generation of excessive tension of the core yarn at the time of cutting. It becomes possible.

(Other)
In the buttonhole sewing machine 10, the first core yarn feeding means 50 and the second core yarn feeding means 60 are provided. However, the first core yarn feeding means 50 is made common. It is good also as a structure provided only with. In such a case, the feeding amount is the sum of the length of all the stitches required for the overlock sewing of one button hole of the core thread, the length of the amount consumed by the cloth base 71 movement and the lower thread cutting means 80 when cutting the core thread. It is desirable to control the movement control means so that it is fed out after completion of the previous sewing and core thread cutting operation and before the start of the sewing.
In addition, when one core thread feeding means is used, the feeding for the length of all the stitches required for the length sewing of one button hole of the core thread is performed after the completion of the previous sewing and the core thread cutting operation. Control is made so that the sewing machine is fed out before the start of sewing, and after the feeding is performed and before the core thread is cut, the cloth 71 moves when the core thread is cut and the length consumed by the lower thread cutting means 80 Control may be performed so that the minute feed is performed.
As a result, the configuration of the buttonhole sewing machine can be simplified and the productivity can be improved.

Further, in the buttonhole sewing machine 10, an air cylinder is used as a drive source for operating the first core yarn feeding means 50 and the second core yarn feeding means 60. Instead, the operation control means controls the operation. A solenoid may be used. Even in that case, it is desirable to provide the above-mentioned stopper.
Further, an actuator such as a solenoid or a voice coil motor capable of adjusting the feed amount may be used.

1 is a side view of a buttonhole sewing machine according to an embodiment of the present invention with a part cut away. The figure which looked at the bed part indicated in Drawing 1 from the upper part is shown. It is a top view which shows the upper surface of the vertical trunk | drum part of a sewing machine frame. It is a side view of a 1st core yarn delivery means. It is the elements on larger scale which show the engagement state of the drawing | feeding-out member of the 1st core yarn delivery means, and the cancellation | release arm. It is the principal part enlarged view which looked at the 2nd core yarn delivery means from the front side. FIG. 7A is an operation explanatory diagram showing a change in the direction of the needle plate from the start to the end of sewing, FIG. 7A is when sewing is started, and FIG. FIG. 7 (C) shows the time of reversal, and FIG. 7 (D) shows the state when the core yarn is cut. FIG. 8A is a perspective view showing an example of a small yarn piece having a heel at both ends as a core yarn supply source, and FIG. 8B is a perspective view showing an example of a normal yarn piece having no heel at both ends. . FIG. 9A shows an appropriate sewing state using an upper thread, a lower thread, and a core thread by eyelet stitching, and FIG. 9B is an explanatory view showing an inappropriate sewing state.

Explanation of symbols

2 sewing machine frame 10 buttonhole sewing machine 11 sewing needle 12 needle bar 14 lower thread holding means 20 looper base 21, 22 looper 25 needle plate 30 core thread holding mechanism 40 core thread guide means 41 guide member 42 guide tube 50 first core Thread feeding means 51 Support plate 52 Threading member 53 Feeding member 54 Air cylinder 60 Second core thread feeding means 61 Threading member 62 Feeding member 63 Air cylinder 70 Cloth holding mechanism (feeding means)
80 Lower thread cutting means C Work cloth

Claims (6)

A needle bar that holds the sewing needle passed through the upper thread and swings the needle in a predetermined direction;
A feeding means for transferring the work cloth;
A looper base comprising a looper that ties the lower thread to the upper thread in cooperation with the sewing needle;
A needle plate provided on the looper base;
Swiveling means for swiveling the needle bar and the looper base during overlock sewing;
A core thread guide means for guiding the core thread from a core thread supply source between needle drop positions that are separated on both sides by the swinging of the sewing needle;
A lower thread cutting means for cutting the lower thread and the core thread after completion of the formation of a predetermined hole seam;
A first core yarn feeding means arranged in the middle of the path of the core yarn guided by the core yarn guiding means, and for feeding the core yarn from the core yarn supply source;
In a buttonhole sewing machine that forms a predetermined hole seam composed of upper thread, lower thread, and core thread around the buttonhole,
A buttonhole sewing machine characterized in that, by the first core thread delivery means, at least core threads for a plurality of stitches in the buttonhole sewing are delivered before the start of the sewing after completion of the previous sewing. The said 1st core thread delivery means delivers the quantity of core thread required for the buttonhole sewing of one buttonhole before the said sewing start after completion of the last sewing. Buttonhole sewing machine. The amount of core thread required for buttonhole sewing of one button hole and the amount of core thread cut by the lower thread cutting means by the first core thread feeding means before the start of sewing after completion of the previous sewing. The buttonhole sewing machine according to claim 1, wherein a total amount of the core yarn is fed out. 3. The first core yarn feeding means feeds in advance an amount of core yarn required for core thread cutting by the lower thread cutting means after the start of sewing and before core thread cutting. Buttonhole sewing machine. The core yarn is disposed in the middle of the path of the core yarn guided by the core yarn guiding means and downstream of the first core yarn feeding means, and an amount of core yarn required for cutting the core yarn by the lower yarn cutting means is the core yarn. Comprising a second core yarn feeding means for feeding from a supply source;
3. The core thread of an amount required for core thread cutting by the lower thread cutting means is fed in advance by the second core thread feeding means after the start of sewing and before core thread cutting. Buttonhole sewing machine. The first core yarn feeding means includes a core yarn feeding member that is driven by a driving means to feed the core yarn from the core yarn supply source,
6. The button hole according to claim 1, further comprising a core thread holding mechanism that prevents the core thread from being drawn from a downstream side of the feeding member when the core thread feeding member is driven. Overlock sewing machine.

Images