JPH1015267A - Hole sewing method and sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perfectly prevent a core thread from being moved without extending the cycle time, by forming a knot at least at one place of core thread sewing, and cutting the core thread so that the knot is remained on the hole edge part at the end of sewing. SOLUTION: Along a core thread guide line 16 from the vicinity of a needle hole 14 of a cloth presser 12, reeling out the core thread 20 by a core thread guide device 18, the core thread 20 is sewn into the stitches formed by needle thread and bobbin thread. First and second thread knotting devices 22 and 24 are equipped on the operator side of the needle hole 14. A knot is formed on at least one place of the vicinity of sewing beginning, the sewing midway, and the vicinity of sewing finish, and the core thread is cut at the sewing finish so that the knot is remained in the hole edge side. Thus moving of the core thread can perfectly be prevented without extending the cycle time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of overlocking a hole edge such as a button hole and a sewing machine.

[0002]

2. Description of the Related Art In a conventional buttonhole edge overlock sewing machine, as shown in FIGS. 21 (A) and 21 (B), a core string guide device 2 extends along a hole edge 1 of a sewing product. While guiding the core 3, the core string 3 is sewn into a seam 5 formed by the upper thread 4 and the lower thread (not shown) so that the hole edge 1 is reinforced.

[0003] In the hole overlock sewing in which the core string 3 is sewn into the seam 5 as described above, the core string 3 is not fixed in the seam 5, so that, for example, the sewn product is made of a knit. In the case of a highly stretchable fabric, when the hole edge 1 is pulled in the direction of the seam 5, the core string 3 moves within the seam 5 and the seam portion is stretched, resulting in a so-called seam laugh. However, the quality of the sewn product may be extremely poor.

[0004]

Conventionally, in order to prevent the core cord 3 from moving within the seam 5 when the hole edge 1 is pulled, two rounds of the seam 5 are conventionally formed or a needle of a needle thread is formed. The swing width is reduced, and the upper thread 4 directly hits (constrains) the core string 3
There was a way to do that.

[0005] However, in the former case, the elongation of the core cord cannot be completely prevented, and the cycle time becomes longer because the seam 5 is formed twice so that the productivity is reduced. There is.

In the case where the needle swing is reduced and the core string 3 is directly restrained by the upper thread 4, especially when a thin thread is used for the core string 3, the upper thread 4 Cannot be restrained.

The present invention has been made in view of the above-mentioned conventional problems, and can completely prevent the movement of the core string without lengthening the sital time, and can reduce the thickness of the core string. Even in such a case, an object of the present invention is to provide a hole overlock sewing method and a sewing machine which can reliably restrain the sewing machine.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method of sewing a hole edge over which a core string is sewn into a seam formed along a hole edge of a sewing product by an upper thread and a lower thread. In the above, a knot is formed at at least one of the vicinity of the sewing start position of the core string, the middle position of the sewing, and the vicinity of the end of the sewing, and the knot remains on the hole edge side when the sewing is completed. In addition, the above object is achieved by a hole edge overlocking method characterized by cutting a core string.

According to a second aspect of the present invention, in the first aspect of the present invention, the knot of the core string is formed by bundling two ends of the core string at the start of sewing and at the end of sewing. It is like that.

According to a third aspect of the present invention, in the first or second aspect, the knot at the start of sewing of the core string and at the end of the sewing are formed in a state where the core string and the upper thread are bundled. It is like that.

According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, the stitch has a bar-tacking portion at the end of sewing and extends to the start of sewing.
The knot at the end of sewing is sewn to the bar-tacking portion.

According to a fifth aspect of the present invention, a knot in the middle of sewing the core string is formed in a state where the middle part of the core string is pulled out like a hairpin and bundled into two pieces.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, at least the former of the core string and the upper thread is gripped and entangled to form a loop, and the loop is used for subsequent sewing. The knot is formed by pulling the opposite side of the loop by the knotting force of the upper thread.

According to a seventh aspect of the present invention, in any one of the first to fifth aspects, at least the former of the core string and the upper thread is gripped and entangled to form a loop, and the loop is gripped. On the opposite side, the knot is formed by pulling the core string.

According to the present invention, a core is provided in a seam formed along a hole edge of a sewn product by an upper thread hung on a needle and a lower thread entangled with the upper thread. In a hole edge overlock sewing machine having a core string guide device for guiding a core string so as to sew a string, in the core string, near a sewing start position to the seam, near a sewing end position,
And, in at least one of the sewing positions,
The object is achieved by providing a thread knot device which can contact the core string, entangles the core string at that position to form a loop, and holds one end of the loop before forming a knot.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, the tying device includes a first tying device near a sewing start position of the core string and a second tying device near a sewing end position.
And a core knot guiding device,
The core string feeding end is adapted to guide the core string from the sewing end position through the first and second tying devices, and wherein the first and second tying devices are On the other hand, the core string is cut at the timing when the formation of the loop and the holding of the core string have been completed on both sides.

According to a tenth aspect of the present invention, in the eighth or ninth aspect of the present invention, after forming the loop of the core string, the thread knot is pulled when the core string is sewn to a seam. Is formed, and the core string is released.

The invention of claim 11 is the invention of claim 8, 9 or 1
In the invention of the first aspect, the yarn knotting device may include a rotation shaft rotatable around a rotation center axis substantially orthogonal to the stretched core cord,
And a yarn knot including a claw portion bent approximately 90 ° continuously from the tip of the rotation shaft, and the core string is formed by an inner angle from the rotation shaft to the claw portion. Over the department
By rotating the rotating shaft, a loop of a core string around which the rotating shaft is wound is formed, and the claw portion of the thread knot is opened and closed on the claw portion main body and the claw portion main body. And a clamp portion swingably supported so as to be able to take an open position opened to an extent that the core string enters and a closed position substantially overlapped with the claw body. A core string wound around a shaft to form a loop can be gripped, and the claw body is provided with a slit into which the clamp section enters in a closed state, and the width of the slit is larger than the thickness of the clamp section. , So as to sandwich the core string.

That is, according to the present invention, the knot of the core string is formed at at least one of the two ends of the core string or the part in the middle of sewing, so that the core string can be pulled in the hole edge direction. The core cord is fixed so as not to move in the knot, so that a so-called seam laugh does not occur.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIGS. 1 and 2, a hole edge overlock sewing machine 10 (all not shown) according to the present invention is arranged along a core string guide line 16 from near a needle hole 14 of a presser foot 12 thereof. While the core string 20 is being fed out by the core string guide device 18, the core string 20 is inserted into the seam formed by the upper thread and the lower thread.
The first and second thread knotting devices 22 and 24 are provided at a position of the needle foot 14 on the operator side of the presser foot 12.

The core string guide line 16 is formed relative to the cloth presser 12 by the cloth being fed by a cloth feeder (not shown).

The first and second yarn knotting devices 22, 24
Are shown in FIGS. 3 to 9 in detail.

Here, the first and second yarn knotting devices 22,
24 has the same configuration, the detailed configuration of the second tying device 24 will be described, and the description of the first tying device 22 will be replaced.

A second knot tying device (hereinafter referred to as a tying device) 24
The rotating shaft 26 is rotatable around a rotation center axis substantially orthogonal to the stretched core cord 20, and the claw 28 bent and extended by approximately 90 ° continuously from the tip of the rotating shaft 26. A thread knot 30 including the core string 20 and an inner corner 30A extending from the rotation shaft 26 to the claw portion 28, and rotating the rotation shaft 26 to thereby rotate the rotation shaft 2
6 is formed so as to form a loop of the core cord 20 around which the core 6 is wound.

As shown in FIGS. 5 and 6, a claw portion 28 of the thread knot claw 30 has a claw body 32 bent approximately 90 ° from the rotation shaft 26 and a claw body 32. , And is pivotally mounted by the pin 32A,
A clamp portion 34 which is openable and closable on the distal end side with respect to the claw body 32 and which can take an open position in which the core cord 20 is opened and a closed position in which the claw body 32 is substantially overlapped; And the core string 20 wound around the rotating shaft 26 to form a loop can be gripped.

The clamp portion 34 includes the claw portion main body 32.
And a cam follower portion 34B which is bifurcated so as to extend on both sides of the rotary shaft 26 when attached to the pin 32A.

The claw portion main body 32 is fitted to a fixed portion 32B, which is a member integral with the rotary shaft 26, and to the pin 32A having the same shape as the fixed portion 32B and penetrating the clamp portion 34. And a detachable portion 32D which is fixed to the fixing portion 32B by a screw 32C via a spacer 33.

The claw portion main body 32 includes the fixing portion 32B.
A slit 36 is formed such that the clamp portion 34 can swing about the pin 32A by interposing the spacer 33 between the mounting portion 32D and the detachable portion 32D.

As shown in FIG. 7 (B), the width of the slit 36 is approximately the sum of the thickness of the clamp portion 34 and the thickness of the core cord 20.
When the core string 4 is closed with the core string 20 sandwiched between the claw body 32, the core string 20 is sandwiched between the clamp portion 34 (tip portion 34 </ b> A) and the claw body 32 in the slit 36. Has become.

As shown in FIG. 7, cutting edges 37A and 37B are formed at opposing corners of the distal end portion 34A and the detachable portion 32D which is slid when the front end portion 34A is closed.
As a result, the clamp portion 34 is
When the is closed, the cutting edge 3 of the inner corner of the tip 34A
The core string 20 is cut by the cutting edge 37A and the cutting edge 37B at the corner of the attaching / detaching portion 32D facing the cutting edge 37A.

As shown in FIG. 7B, the cut core string 20 is held in the slit 36 while being sandwiched between the fixing portion 32B and the distal end portion 34A. Has become.

The tying claw 30 is connected to the rotating shaft 26 in FIG.
As shown in the figure, the rotary drive shaft 38 is inserted into a mounting hole 38A and fixed by a set screw 38B. A ring-shaped cam 42 is mounted on the end face of the casing 40 of the rotary drive shaft 38 so that its rotational direction mounting position can be adjusted.

As shown in FIGS. 5 and 6, the ring-shaped cam 42 has a cam hole 42 eccentric from an outer circumference 42A.
B is provided.

The thread knot 30 has a rotating shaft 26,
By being set in the mounting hole 38A of the rotary drive shaft 38, it is mounted at the center of the outer circumference 42A of the ring cam.

Accordingly, when the pawl portion 28 is rotated about the rotary shaft 26 by the rotary drive shaft 38, the cam follower portion 34B of the clamp portion 34 slides into the cam hole 42B of the ring cam 42. Accordingly, the distal end portion 34A is opened and closed with respect to the claw portion main body 32 according to the amount of eccentricity.

The cutting blades 37A and 37B are formed only on the second knot tying device 24 side. Further, as shown in FIG. 8, the first
Is slightly wider than the yarn knotting device 24, so that the core string 20 can be held without being cut.

As shown in FIG. 1, the first thread knotting device 22 extends from the starting position of the core string sewing line in the core string guide line 16 in the downward (operator side) extension line in the figure. It is arranged so that the inner corner 30 </ b> A of the thread knot 30 is located. Also, the second knotting device 24
The line extending downward from the end position of the core string guide line 16 in FIG.
A.

Further, the core string guide device 18 guides the core string 20 along the core string guide line 16 and then adjusts the inner corners 3 of the yarn knot 30 in the second yarn knot device 24.
1A, further passes through the position of the inner corner 30A of the yarn knot 30 of the first yarn knot device 22, moves to the lower left in FIG. 1, and further returns rightward from that position. To return to the starting position of the core string sewing.

The rotary drive shaft 38 of the first and second yarn knotting devices 22 and 24 has a pulse motor 4
4 and are directly driven by these pulse motors 4
4 is such that the rotation angle thereof is controlled by the control device 46. The position of the core string guide device 18 is also controlled by the control device 46.

Next, a description will be given of a process of sewing the core string 20 into a seam by the hole edge overlock sewing machine.

First, in the case of the first hole overlock stitching, as shown in FIG.
A is formed, and in this state, the first yarn knotting device 22 is held in the slit 36 by the clamp portion 34, and then the core string 20 is moved along the core string guide line 16 by the core string guide device 18. , Relative to the work clamp 12.

At this time, as shown in FIG. 10, the core string 20 is joined to the seam 2 by the upper thread 21A and the lower thread (not shown).
When the sewing operation is started, the core string 20 is pulled by the knotting force of the upper thread and released from the slit 36 of the first thread knotting device 22. The core string 20 is sequentially sewn into the seam 21 to form the upper bar-tacking portion 21B in FIG. 10, and then reaches the vicinity of the sewing end position.

When the sewing of the upper bar-tacking portion 21B is completed, as shown in FIG. 11, the thread tying claws 30 of the first and second thread tying devices 22 and 24 are brought into a horizontal state, and both ends thereof are moved to the horizontal position. However, it is made to stand by toward the needle hole 14. In this state, the core string 20 is passed by the core string guide device 18 to the inside corner position of the yarn knot 30 in the second yarn knot device 24, and then the thread knot 30 of the second yarn knot device 24 is 10, by the pulse motor 44, it is turned downward as shown in FIG.
Hook the core string 20.

From here, the core string guide device 18 further passes the core string 20 through the inner corner portion 30A of the horizontal knot 30 in the first yarn knot device 22. At this time, the core string guide device 18 is moved leftward in the figure to the position indicated by the two-dot chain line in FIG.

Next, as shown by a solid line in FIG. 10, the thread tying claw 30 of the first thread tying device 22 is turned downward.
When driven by the pulse motor 44 and the core string guide device 18 is moved rightward from the position indicated by the two-dot chain line in this state, the core string 20 becomes the inner corner of the yarn knot 30 of the first yarn knot device 22. It will be hooked on the part 30A.

Next, the pulse motor 44 of the second tying device 24 is driven by the control device 46 to
0 is rotated clockwise from the state of FIG. 3 as shown in FIG.

From the state shown in FIG.
When rotated, the tip of the knot 30 causes the core string 2
0 is entangled to form a loop around the rotary shaft 26 (see FIG. 6).

When the thread knot 30 is further rotated in the clockwise direction, the cam follower portion 34B of the closed clamp portion 34 is moved to the cam hole 42B of the ring cam 42.
Of the rotating shaft 26 as a center, the tip portion 34A is opened, and as shown in FIG.
4A and the claw body 32.

Next, the state of the second knotting device 24 is kept as it is, and the first knotting device 22 is rotated by the same procedure as that of the second knotting device 24 described above. Thus, a loop of the core string 20 is formed around the rotation shaft 26.

Next, the knot 3 of the second knot device 24
0 between the claw body 32 and the clamp 34.
7 is further rotated clockwise in a state where the
As shown in (A), the core string 20 has cutting edges 37A, 37A.
Cut by B.

The end of the cut core string 20 on the seam side is
As shown in FIG. 7 (B), it is held in the slit 36. However, when the core thread 20 is further sewn by the upper thread 21A, it is pulled in the direction of the seam 21 and becomes as shown in FIG. 12 (A).
As shown in (B), the loop of the core string 20 slides along the inclined surface 30B of the thread knot 30 and is further pulled to form the knot 20B as shown in FIG. Then, the end of the core string 20 is pulled out of the slit 36 and released, and finally sewn into the stitch 21.

On the other hand, on the side of the first
Unlike the knot tying device 24, the claw portion 28 has no cutting edge, so that the core string 20 is pushed into the slit 36 by the distal end portion 34A of the clamp portion 34, as shown in FIG. In the state, it is held without being cut. Next, as shown in FIG.
But the direction in which the core string 20 is not released (downward in the figure)
And the core string 20 is pulled by the core string guide device 18 to form the knot 20A.

As described above, the yarn knot 30 of the first yarn knot device 22 holds the core string 20 in a state where the knot 20A is formed, and then the yarn knot 30 is moved as shown in FIG. Then, the tip is directed toward the sewing start position in a range where the core cord 20 is not opened, and from here, the next hole edge overlock sewing is started.

Accordingly, the core string 20 is guided by the core string guide device 18 to the position indicated by the two-dot chain line in FIG.
The core string 20 is sewn into the seam 21 of the upper thread 21A and the lower thread. At this time, the core string 20 is pulled by the knotting force of the upper thread 21A.
Released from.

Since the core string 20 is pulled by the knotting force of the upper thread as described above, the knot 20A is pulled up to the start position of the seam 21 as shown in FIG. Is sewn here together with the final knot 20B.

It should be noted that cutting edges 37A and 37B are formed on the yarn knot 30 of the second yarn knotting device 24, so that the core cord 20 is cut off at the time of yarn knotting. This may be cut at the first yarn knotting device 22 side. In this case, the sewn amount of the core string 20 on the side where sewing is finished to the bar-tacking portion 21C is longer than that in the case described above.

The reason why both the first and second yarn knotting devices 22 and 24 are not provided with both cutting edges for cutting the core cord 20 on the yarn knot 30 is that the core The purpose of this is to prevent cutting chips from being generated, and in the case where a suction device is provided, for example, when a suction device is provided, cutting blades may be provided on both.

In the above embodiment, the core string 20 is formed by the first and second thread knotting devices 22 and 24, and the knots 20B and 20A are formed on the sewing start side and the sewing end side, respectively. However, the present invention is not limited to this, and the knot is formed on the core string 20 from the beginning of the sewing to the seam to the end of the sewing or one of its ends. Should be fine.

For example, as in the second embodiment of the embodiment shown in FIGS.
The core string 20 may be formed by bundling both the end portion on the start side and the end portion on the end side of the seam to form the knot 20C.

14 and 15, reference numeral 50 denotes a thread holding spring,
Reference numeral 52 denotes a pin for bundling the end of the core string 20 at the start of sewing and the end of the core string 20 at the end of sewing.

In the example of this embodiment, the core string 20
While the sewing start side end and the sewing end side end are elastically held by the thread holding spring 50 by the core string guide device 18, the thread is entangled by the thread tying device 48 to form a loop. .

Thereafter, the tip of the knot 30 is inserted into the pin 52.
When the hole overlock sewing is started by the needle 54 toward the side, the knotting force of the upper thread 56 pulls the core cord 20 as shown in FIG.
C is formed and pulled further, resulting in knot 2
0C is released from the claw portion 28 and reaches the bar-tacking portion 21C.
It will be sewn here at the time of bar-tacking sewing before the end of overhole sewing.

Next, a description will be given of an example of an embodiment in which a knot is formed during the sewing of the core string into the thread.

FIGS. 16 and 17 show examples of this embodiment.
As shown in FIG. 3, a pair of guide pins 60A, 60A are spaced apart in the core string direction in the middle of the yarn path of the core string 20.
B is provided, and a guide rod 62 that moves across between the guide pins 60A and 60B, and a position where the core string 20 pulled from between the guide pins 60A and 60B can be entangled by the guide rod 62. And a thread tying device 64 arranged. Reference numeral 66 in the figure denotes a motor or a solenoid for swinging the guide rod 62.

The guide rod 62 is driven by a motor 66
The core string 20 passing through the side of the guide pins 60A, 60B is pulled from the side opposite to the guide pins 60A, 60B to the opposite side through the space between these guide pins 60A, 60B, and the pulled core string 20 is As shown in FIG. 17, the loop is formed by entanglement with the tying claw 30 of the tying device 64, and thereafter, as in the second tying device 24, the loop-side end of the core cord 20. Hold. At this time, the core string 20
Has a loop formed by bundling the two.

Next, when the core string 20 is sewn by the upper thread, the knot force is pulled in the same manner as described above, the loop is closed, and the knot 20D is formed. The guide bar 62 returns to its original position when the knot 20D is formed.

Since the knot 20D is sewn to the seam, the core string cannot be moved within the seam.

In the yarn knotting device 64, the core string 20 is not cut after the loop is formed but is formed in a loop shape, but this may be cut.

Next, a fourth example of the embodiment of the present invention shown in FIGS. 18 to 20 will be described.

In this example, the core string 20 and the upper thread 56 are
A knot is formed by a first knotting device 22 and a second knotting device 24 as in the examples in FIGS. 1 and 2.

In this way, the knot 2 formed by the second knot tying device 24 at the end of the hole edge overlock stitching.
0E remains on the seam side as shown in FIG.
The knot 20F formed by the knot tying device 22 is in a state of connecting the upper thread 21A and the core string 20.

At the start of the next hole overlock sewing, as shown in FIG. 20, the knot 20F remains on the upper side of the sewing product 56, thereby preventing the so-called upper thread from slipping off at the start of sewing. As described above, it is possible to prevent the seam from growing. Reference numeral 58 in the figure indicates a lower thread.

The knot 20F may be forcibly pulled into the lower side of the sewing product 56 by the needle 54.
In this case, it is possible to prevent the upper thread from slipping off and prevent the seam from extending as described above, and to improve the quality of the sewn product by the knot 20F entering the lower side of the sewn product 56. The knot 20E formed by the second knot tying device 24 is knotted when the sewing product 56 is moved to the next sewing position.

[0075]

Since the present invention is constructed as described above, by forming a knot on the core string, it is possible to prevent the core string from moving within the seam, thereby preventing so-called seam laughter. Has the effect.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a hole edge overlock sewing machine according to a first example of an embodiment of the present invention.

FIG. 2 is a front view of the main part.

FIG. 3 is a perspective view showing the operation of the thread knotting device in the overhole sewing machine.

FIG. 4 is an enlarged perspective view showing a yarn knitting claw in the yarn knotting device.

FIG. 5 is an exploded perspective view of the thread knot.

FIG. 6 is a sectional view showing the operation of the thread knot;

FIG. 7 is a cross-sectional view showing a cutting and holding process of the core string in the same knot.

FIG. 8 is a sectional view showing a process of holding the core string by the thread knot.

FIG. 9 is a plan view showing a state at the start of sewing of the hole edge overlock sewing machine.

FIG. 10 is a plan view showing a state immediately before the end of the sewing.

FIG. 11 is a plan view showing a state during the sewing.

FIG. 12 is a plan view showing a knot forming process of a core string in the yarn knotting device.

FIG. 13 is a plan view showing a state in which a knot is formed in the hole overlock sewing machine.

FIG. 14 is a plan view showing a main part of a hole edge overlock sewing machine according to a second example of the embodiment of the present invention.

FIG. 15 is a side view of the same.

FIG. 16 is a perspective view showing a main part of a hole edge overlock sewing machine according to a third embodiment of the present invention.

FIG. 17 is a perspective view showing the same operation.

FIG. 18 is a perspective view showing a main part of a hole edge overlock sewing machine according to a fourth embodiment of the present invention.

FIG. 19 is a perspective view showing a state of a knot formed by the fourth example.

FIG. 20 is a perspective view showing the state of the knot at the start of sewing in the fourth example.

FIG. 21 is a plan view showing the relationship between a seam and a core string of a conventional hole edge overlock stitch.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Hole overlock sewing machine 12 ... Cloth presser 14 ... Needle hole 16 ... Core string guide line 18 ... Core string guide device 20 ... Core string 20A, 20B, 20C, 20D, 20E, 20F ... Knot 21 ... Seam 21A ... Upper thread 21B, 21C: Bar-stopping part 22: First tying device 24: Second tying device 26: Rotating shaft 28: Claw portion 30: Thread claw 30A: Inner corner portion 32: Claw body 34: Clamp portion 46 ... Control device 48 ... Thread tying device 54 ... Needle 60A, 60B ... Guide pin 62 ... Guide rod 64 ... Thread tying device 56 ... Sewn product 58 ... Bottom thread

Claims (11)

[Claims] 1. A hole edge overlock stitching method in which a core string is sewn into a seam formed along a hole edge of a sewn product by an upper thread and a lower thread. A knot is formed in at least one of the positions near the sewing position, the middle position of the sewing, and the position near the end of the sewing, and when the sewing is completed, the core cord is cut so that the knot remains on the hole edge side. Overhole sewing method characterized by holes. 2. The knot of the core cord according to claim 1,
A hole overlock stitching method, characterized in that the core string is formed in a state in which the end of sewing and the end of sewing are bundled into two. 3. The hole according to claim 1, wherein the knot at the start of sewing of the core string and at the end of sewing are formed in a state where the core string and the upper thread are bundled. Overlocking method. 4. A stitch according to claim 1, 2 or 3, wherein the stitch has a bar-tacking portion at the end of sewing, leading to the start of sewing, and the knot at the start of sewing on the core string and the knot at the end of sewing. A hole edge overlock sewing method, wherein sewing is performed on the bar-tacking portion. 5. The hole rim according to claim 1, wherein the knot in the middle of the sewing of the core string is formed in a state where the middle part of the core string is pulled out like a hairpin and bundled into two pieces. Sewing method. 6. A loop according to claim 1, wherein at least the former of the core string and the upper thread is gripped and entangled to form a loop, and the knotting force of the upper thread at the time of sewing thereafter. A method according to claim 1, wherein the knot is formed by pulling the opposite side of the loop when the loop is gripped. 7. The core string according to claim 1, wherein at least the former of the core string and the upper thread is gripped and entangled to form a loop. Forming a knot by pulling a hole. 8. A core string is sewn into a seam formed along a hole edge of a sewing product by an upper thread hung on a needle and a lower thread entangled with the upper thread. In the hole edge overlock stitch sewing machine having a core string guiding device for guiding, in the core string, near the sewing start position to the seam, near the sewing end position, and at least one of the sewing middle positions, A hole overlock sewing machine, comprising: a thread knot device capable of making contact with the core string, tangling the core string at that position to form a loop, holding one end of the loop, and forming a knot. 9. The tying device according to claim 8, wherein the tying device comprises: a first tying device near a sewing start position of the core cord;
A second thread knot device in the vicinity of the sewing end position, wherein the core string guide device has a core string feeding end portion for connecting the core string to the first and second positions from the sewing end position. Through the knot tying device, and the first
And the second yarn knotting device, wherein the core string cutting on one side is configured to be performed at a timing when the formation of the loop and the holding of the core string on both sides are completed. . 10. The yarn knotting device according to claim 8, wherein after forming the loop of the core string, when the core string is sewn to a seam, the knot is formed by being pulled, and
A hole edge overlock sewing machine, wherein the core string is released. 11. The tying device according to claim 8, 9 or 10, wherein the tying device comprises: a rotation shaft rotatable around a rotation center axis substantially orthogonal to the stretched core cord; And a thread tying claw including a claw portion bent and extended by approximately 90 °, and rotating the rotation shaft by applying the core cord to an inner corner portion from the rotation shaft to the claw portion. Thereby, a loop of a core string that winds the rotation shaft is formed,
The claw portion of the tying claw has a claw body and an open position where the distal end side is openable and closable with respect to the claw body, and is opened to the extent that the core cord enters, and a closed position substantially overlapped with the claw body. A clamp portion swingably supported so as to be able to take a position, and a core string wound around the rotating shaft to form a loop can be gripped, and the claw portion main body is
In the closed state, a slit into which the clamp portion enters is provided,
A hole overlock sewing machine characterized in that the width of the slit is made larger than the thickness of the clamp portion so as to sandwich the core string.