JP6059917B2 - Double chain stitch machine - Google Patents

Description

  The present invention relates to a double chain stitch sewing machine having one or more sewing needles.

FIG. 38 shows a state in which a seam of a general double chain stitch in a two-needle is viewed from the back side of the fabric.
Double chain stitching is a looper thread that is formed when a needle is dropped with two sewing needles, a looper is inserted into the loop of each needle thread, and the looper is pulled out from the loop of each needle thread. The next needle drop is performed on this loop, and these are repeated to form a seam in a state where the loops and looper threads of each needle thread are alternately inserted.
In the double chain stitch, the loop L1 of the looper thread L formed between the loop T21 of the right needle thread T2 and the loop T11 of the left needle thread T1, and the loop L2 of the looper thread L drawn from the needle thread loop T11, Is formed.
At the sewing end position, the thread end T22 of the right needle thread T2 is inserted into the loop L1 of one looper thread L, and the thread end T12 of the left needle thread T1 is inserted into the loop L2 of the other looper thread. Will be inserted.

Even if the thread end L3 of the looper thread L is pulled at the thread end of the double chain stitch seam, the thread end L3 is passed through the loop T21 of the right needle thread T2. The seam of the seam is maintained without fraying.
However, when the yarn end portion L3 of the looper yarn L is pulled to some extent, the yarn end portion T22 passed through the loop L1 comes out, and further, the loop L2 of the looper yarn L comes out of the loop T11 of the left needle yarn T1, In addition, the right needle thread T2 comes out of the loop T21. Since the looper thread L is a stitch having a structure in which the loops L1 and L2 formed by the next needle entry hold the loops L1 and L2 formed by the previous needle entry, the looper thread L is the loop T11 of the needle threads T1 and T2. When it begins to come off from T21, all the looper yarns L are eventually frayed.
When all the looper threads L are thus removed from the loops T11 and T21 of the needle threads T1 and T2, the needle threads T1 and T2 cannot maintain the seams, and the thread ends T12 and T22 are pulled. All you can do is fray.

In this way, the double chain stitches are prone to fraying, and a double chain stitch formation method as shown in FIG. 39 has been proposed to prevent this.
In this double ring stitch formation method, the looper connected from the fabric to the looper's eye hole with the needle at the top dead center at the end of sewing and the looper most advanced to the left (right side in FIG. 39). The thread L is hooked on the hook on the left side of the left needle to form a loop L2. In this state, the needle and looper are driven by one stitch. Thereafter, the hook knife is moved back and forth to hook the two needle threads T1 and T2 that are connected to the lower part of the blade of the looper from the cloth, and the looper thread (corresponding to L3 in the figure) that is connected to the eye of the looper from the cloth. Then, the hook needle and fixed knife engage the hooked two needle threads T1, T2 and the looper thread L3 to cut between the fabric and the looper. Further, when the hook rotates and returns to the position of the receiving knife, the loop L2 of the looper thread is cut by the receiving knife and a new thread end L4 of the looper thread L is formed.
The double chain stitch formed in this way remains in a state of being sandwiched between the loop end L4 of the looper thread L knotted through the loop T11 of the left needle thread T1 and the loops T11 and T21 of the needle threads T1 and T2. The loop L1 of the looper yarn is not continuous. Therefore, when the looper thread L1 is pulled out from the loops T11 and T21 by pulling the thread end L3, the thread end L4 of the looper thread L does not come out of the loop T11 of the left needle thread T1, and the thread of the looper thread L The state where the end L4 is knotted through the loop T11 of the left needle thread T1 is maintained.
In this state, fraying does not occur even if the yarn end L4 of the looper yarn L is pulled, so that the seam can be stably held (see, for example, Patent Document 1).

Japanese Patent No. 3318482

  However, even when the seam of FIG. 39 is formed, if the looper thread L is pulled in the middle and the thread end L4 is pulled out from the final loops T11 and T21 of the needle threads T1 and T2, FIG. There was a problem that all the looper yarn L and needle yarns T1 and T2 were frayed in the same state as in No. 38.

  An object of the present invention is to more effectively prevent yarn fraying.

According to the first aspect of the present invention, a feed mechanism that conveys the sewing product in a certain direction, a needle vertical movement mechanism that moves the sewing needle up and down, and a looper along a direction that intersects the conveyance direction of the sewing product. In a double chain stitch sewing machine that has a looper mechanism for moving forward and backward, and that performs double chain stitching, the knot forming device that connects the end ends of the needle thread and the looper thread , and the looper thread and the needle thread are bundled together A knot forming device having a hook member for capturing the knot, and the knot forming device forms a knot on the looper thread and the needle thread captured by the thread locking device. .

According to the second aspect of the present invention, a feed mechanism that conveys the sewing product in a certain direction, a needle vertical movement mechanism that moves the sewing needle up and down, and a looper along a direction that intersects the conveyance direction of the sewing product. A double chain stitch sewing machine that performs double chain stitching, and includes a knot forming device that connects the sewing thread end ends of the needle thread and looper thread, and the knot forming device is rotatable. A yarn winding member that is supported and extends in a direction deviating from the rotation center line, and a clamp member that is attached to the yarn winding member and is rotatably provided to the yarn winding member; A fixed knife attached to the clamp member, a rotation driving unit that integrally applies a rotation operation to the yarn winding member, the clamp member, and the fixed knife, and rotation by the rotation driving unit. In, characterized in that it comprises a cam mechanism to impart rotational movement to the clamping member.

The invention described in claim 3 has the same configuration as that of the invention described in claim 2 , and the knot forming device passes the needle thread and the looper thread within the capturing range of the thread winding member. It comprises a pair of guide portions that are supported in an inclined state with respect to the rotation center line of the yarn winding member .

The invention described in claim 4 has the same configuration as that of the invention described in claim 3 , and the knot forming device is configured such that one of the guide portions moves toward the rotation center of the yarn winding member. The tip is extended to the inside of the radius of rotation .

The invention according to claim 5 has the same configuration as that of the invention according to any one of claims 1 to 4, and the knot forming device is provided on the sewing end end side of the needle thread and the looper thread. It is characterized by performing thread trimming and knotting operation at the end of sewing .

The invention according to claim 6 has the same configuration as that of the invention according to any one of claims 1 to 5, and a plurality of sewing needles arranged in a line along the advancing / retreating movement direction of the looper, The knot forming device is characterized in that when the looper protrudes most, a needle thread of a sewing needle that is located closest to a distal end side of the looper and a sewing end end of the looper thread are connected to each other .

Since the knot forming device ties the stitching end portions of the needle thread and the looper thread to each other, the invention according to claim 1 prevents the loop of the needle thread from coming out even if the looper thread is pulled after the completion of the sewing. The fraying of the yarn can be effectively suppressed.
Moreover, since the looper thread and the needle thread are bundled and captured by the hook member, it is possible to more easily and reliably perform the operation of connecting the looper thread and the sewing thread end ends of the needle thread by the knot forming device.

In the invention according to claim 2, since the knot forming device ties the stitching end portions of the needle thread and the looper thread, even if the looper thread is pulled after completion of the sewing, it is prevented from coming out of the loop of the needle thread. The fraying of the yarn can be effectively suppressed.
Further, since the yarn winding member extends in a direction deviating from the rotation center, when the loop winding yarn and the needle yarn are arranged within the rotation radius of the tip portion of the yarn winding member, the yarn winding member is rotated. The tip portion of the looper thread and the needle thread can be caught so as to be caught.
The clamp member provided alongside the yarn winding member rotates by the cam mechanism as the yarn winding member rotates, so that the looper yarn and needle thread captured by the yarn winding member in cooperation with the fixed knife. Can be cut off.
Furthermore, the needle thread and looper thread wound around the tip of the thread winding member are pulled out while the thread winding member holds the end of the cut needle thread and looper thread, so that a knot is finally formed. can do.
Thus, in the above-described invention, it is possible to form a knot between a needle thread and a looper thread without requiring a complicated structure .

According to the third aspect of the present invention, since the guide portion supports the needle thread and the looper thread in a slanted state, the needle thread and the looper thread can be easily wound around the thread take-up member and captured. It is possible to perform the formation more reliably .

In the invention according to claim 4, since one of the guide portions extends to the inside of the rotation radius of the tip portion of the yarn winding member toward the rotation center side of the yarn winding member, the needle yarn and the looper yarn are The yarn winding member can be disposed at a deeper position within the catching range of the yarn winding member, and the yarn catching can be performed more reliably .

According to the fifth aspect of the present invention, the knot forming device performs the thread trimming and knotting on the side of the sewing end of the needle thread and the looper thread, so that, for example, the thread trimming operation by the operator is unnecessary at the end of the sewing. be able to.
Further, since the thread trimming and knotting are performed, the needle thread and the looper thread are not separated after the thread trimming, and it is possible to perform these knotting operations more reliably without failing .

In the invention according to claim 6, since the knot forming device ties the needle thread of the sewing needle located closest to the tip end side of the looper and the sewing end ends of the looper thread, the loops of the looper thread are loops of the respective needle threads. It is possible to prevent the thread from coming out of the thread, and to more effectively suppress fraying of the yarn .

It is a perspective view of the double chain stitch sewing machine which is an embodiment of the invention. It is explanatory drawing of the sewing operation | movement of a double ring stitch. FIG. 3 is an explanatory diagram of a sewing operation of double chain stitch following FIG. 2. It is explanatory drawing of the sewing operation | movement of the double chain stitch following FIG. It is explanatory drawing of the sewing operation | movement of the double chain stitch following FIG. It is explanatory drawing of the thread trimming operation | movement of one needle thread. It is a top view of a knotter device and a thread locking device. It is a side view of a knotter device and a thread locking device. It is a side view which shows the whole knotter apparatus. It is a disassembled perspective view of a knotter. It is the expanded side view which notched a part by the side of the front-end | tip part of a knotter apparatus. It is an enlarged front view by the side of the front-end | tip part of a knotter apparatus. It is a top view of an upper guide plate. It is a block diagram which shows the control system of a double chain stitch sewing machine. It is a flowchart which shows the operation control of the thread trimming at the time of completion | finish of sewing, and a thread knotting operation | movement. FIGS. 16A and 16B are operation explanatory views of thread trimming and thread knotting at the end of sewing, FIG. 16A is a front view, and FIG. 16B is a side view. FIG. 17 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 16, FIG. 17 (A) is a front view, and FIG. 17 (B) is a side view. FIG. 18 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 17, FIG. 18 (A) is a front view, and FIG. 18 (B) is a side view. FIG. 19 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 18, FIG. 19 (A) is a front view, and FIG. 19 (B) is a side view. FIG. 20 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 19, FIG. 20 (A) is a front view, and FIG. 20 (B) is a side view. FIG. 21 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 20, FIG. 21 (A) is a front view, and FIG. 21 (B) is a side view. FIG. 22 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 21, FIG. 22 (A) is a front view, and FIG. 22 (B) is a side view. FIG. 23 is an operation explanatory view of thread trimming and thread knotting at the end of sewing subsequent to FIG. 22, in which FIG. 23 (A) is a front view, FIG. 23 (B) is a side view, and FIG. 23 (C) is an enlarged side view. FIG. 24 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 23, FIG. 24 (A) is a front view, and FIG. 24 (B) is a side view. FIG. 25 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 24, FIG. 25 (A) is a front view, and FIG. 25 (B) is a side view. 26 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 25, FIG. 26 (A) is a front view, and FIG. 26 (B) is a side view. FIG. 27 is an operation explanatory view of thread trimming and thread knotting at the end of sewing following FIG. 26, FIG. 27 (A) is a front view, and FIG. 27 (B) is a side view. It is the figure which looked at the needle thread | yarn tied with the knotter apparatus and the looper thread | yarn from the back side of the fabric. It is a figure which shows the example which performed the thread trimming and the thread knot to the seam of FIG. It is operation | movement explanatory drawing for performing the yarn knot of FIG. It is operation | movement explanatory drawing following FIG. It is operation | movement explanatory drawing following FIG. FIG. 33 is an operation explanatory diagram following FIG. 32. It is operation | movement explanatory drawing following FIG. It is the figure which applied thread trimming and thread knot to double chain stitching in case there is one sewing needle. It is the figure which applied thread trimming and thread knot to other double chain stitches when there is one sewing needle. It is a figure which shows the example which formed the projection part extended to the rotation center line side from the lower surface of a guide plate. It is a figure which shows the example of the seam of the conventional double ring stitch. It is a figure which shows the example of the stitch of other conventional double ring stitches.

[Outline of sewing machine]
The double chain stitch sewing machine 100 according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a double chain stitch sewing machine 100. In this figure, the longitudinal direction of the arm 10 and the bed 20 which will be described later is the Y-axis direction, and is horizontal and orthogonal to the Y-axis direction. The direction to perform is the X-axis direction. A direction orthogonal to both the X-axis direction and the Y-axis direction is taken as a Z-axis direction. If necessary, as shown in FIG. 1, the downstream side in the cloth feeding direction, that is, one in the X-axis direction is “front”, the other is “rear”, and one in the Y-axis direction is “left”. The other is described as “right”.

  The double chain stitch sewing machine 100 (hereinafter referred to as the sewing machine 100) is a sewing machine that forms a seam by entwining a looper thread passed through a looper with a needle thread loop formed by a needle thread passed through a sewing needle. is there. Some double chain stitch sewing machines include one or more sewing needles. In this embodiment, a case where two sewing needles are provided is illustrated.

[Thread path]
The sewing machine 100 includes an arm portion 10 and a bed portion 20 that supports the arm portion 10.
The arm portion 10 is provided with an upper shaft (not shown) along the Y-axis direction, and the upper shaft is rotated by a sewing machine motor 15 (see FIG. 14). A crank mechanism as a needle up-and-down movement mechanism is provided at the tip of the upper shaft, and the vertical movement is applied to the needle bar 14 by the crank mechanism. Two sewing needles 11 and 12 are provided at the lower end of the needle bar 14 along the Y-axis direction.
A thread tension device 30 that applies tension to each thread (needle threads T1, T2, looper thread L) guided from a thread winding (not shown) that is a thread supply source is provided on the front surface of the arm unit 10.

The thread tension device 30 applies tension to the needle threads T1 and T2 and the looper thread L, and three sets of thread tension plates individually clamp the needle threads T1 and T2 and the looper thread L, and each of them is held by the clamping force. Adjust the tension of the threads T1, T2, L.
The needle threads T1, T2 whose tension is adjusted by the thread tension device 30 are inserted into the eye holes of the sewing needles 11, 12 via a plurality of thread hooks 31, 33 and the balances 32, 34 arranged therebetween. ing.
Further, the looper yarn L whose tension is adjusted by the thread tension device 30 is inserted into the eye hole of the looper 13 via the plurality of yarn hooking portions 35 and 36 and the looper yarn adjusting mechanism 37.

  The balance 32 is provided on the upper surface of the arm portion, and the balance 34 is provided on the front surface of the arm portion 10, and moves up and down together with the needle bar 14. The balances 32 and 34 are formed with insertion holes for needle threads T1 and T2, and when the balances 32 and 34 are raised, the needle threads T1 and T2 are fed out from the yarn supply source side and the needle threads T1 from the fabric side. , T2 is raised.

[Looper related]
In the bed part 20, a lower shaft 21 is provided along the longitudinal direction of the bed part 20 (the left-right direction of the sewing machine). The lower shaft rotates in conjunction with the above-described upper shaft and a belt mechanism or a gear mechanism.
The lower shaft 21 is provided with a looper shaft (not shown) in parallel with the lower shaft. This looper shaft is provided with a looper 13. When the lower shaft 21 is rotated, the looper 13 is reciprocated so that the rotation is transmitted to the looper shaft so as to be in contact with and separated from the needle drop position of the sewing needle 11.
In the bed portion 20, a looper yarn adjusting mechanism 37 is provided on the looper yarn L path between the looper 13 and the thread tension device 30.

  The looper yarn adjusting mechanism 37 includes an outer circumferential cam that is in sliding contact with the looper yarn L, and the outer circumferential cam is rotated by the lower shaft 21. The outer peripheral cam has a shape in which the distance from the rotation center to the outer periphery is not uniform, and the rotation of the lower shaft 21 causes the looper yarn L to be periodically fed out from the yarn supply source side and the looper yarn from the fabric side. L is pulled back.

The looper 13 includes a sword that extends toward the surface of the sewing machine. The looper 13 has a length along the Y-axis direction by combining a reciprocating motion along the Y-axis direction and a reciprocating motion along the X-axis direction by a looper mechanism (not shown). A circular motion is given.
That is, the tip of the looper 13 moves while drawing a trajectory around the needle drop position of the sewing needles 11, 12, and the looper 13 moves to the left to move the two sewing needles 11, 12. It passes between the sewing needles 11 and 12 and the needle threads T1 and T2 while passing the front side (downstream side of the cloth feed), and then moves somewhat backward to the rear side (upstream side of the cloth feed) of the needle drop position. The sewing needles 11 and 12 move toward the triangular space surrounded by the loops T11 and T21 of the needle threads T1 and T2 supplemented by the loop L11 and the looper 13 of the looper thread L. storm in. By repeating this movement, double chain stitching is performed (see FIGS. 2 to 5).
The looper mechanism provides a looper support bar 38 that holds the looper 13 at its tip and a revolving operation around the Y axis while allowing the looper support bar 38 to reciprocate in the Y axis direction. A rotating table, an eccentric cam mechanism for converting the rotating operation of the lower shaft 21 into a reciprocating rotating operation and transmitting it to the rotating table, and a crank mechanism disposed along the X-axis direction and from the lower shaft 21. A looper shaft that reciprocates around the X-axis, and a rotation device that is fixedly mounted on the looper shaft and rotates around the X-axis, and also reciprocates along the Y-axis direction with respect to the looper support rod 38 And mainly an arm member.
With these configurations, the looper support rod 38 and the looper 13 are synchronously provided with the reciprocating motion along the Y-axis direction and the reciprocating rotational motion around the Y-axis, so that the looper 13 is substantially X−. An ellipse motion along the Y plane is realized.

[Cloth feed mechanism]
Further, the bed portion 20 has a well-known cloth feed mechanism (not shown) including a feed dog that moves in and out of the needle plate by an ellipse motion along the XZ plane and a drive unit that imparts an ellipse motion to the feed dog. Built in. The cloth feed mechanism moves forward when the feed dog emerges from the needle plate, and performs a cloth feed operation at a predetermined pitch on the cloth W (see FIG. 2) that is a sewing object.

[Double chain stitch operation]
Here, a basic double chain stitch formation operation by the sewing machine 100 will be described with reference to FIGS.
As shown in FIG. 2, the looper 13 moves to the left and enters the two loops T11 and T21 of the needle threads T1 and T2 to capture the loops T11 and T21.
Then, as shown in FIG. 3, the respective sewing needles 11, 12 are lowered into the triangular space surrounded by the loop L <b> 11 of the looper thread L and the loops T <b> 11, T <b> 21 of the needle threads T <b> 1 and T <b> 2. Thereafter, as shown in FIG. 4, the looper 13 is retracted to the right, and the state in which the loop L11 of the looper thread L is inserted into the loops T11 and T21 of the needle threads T1 and T2 by the sewing needle 11 is maintained.
Then, as shown in FIG. 5, when the sewing needles 11 and 12 start to rise, the looper 13 again moves to the left and passes through the front side (downstream side of the cloth feed) of the two sewing needles 11 and 12. However, it enters between the sewing needles 11 and 12 and the needle threads T1 and T2, and loops T11a and T21a of the needle threads T1 and T2 supplemented by the looper 13 are formed.
As described above, by repeating the operations of FIGS. 2 to 5, the operation of inserting the loop of the looper thread L and the loops of the needle threads T1 and T2 is repeated to form a double chain stitch. .
As described above, the double chain stitch illustrated in the present application is of the type defined as the stitch type display symbol 406 in Japanese Industrial Standards (JIS), but other types are used. May be.

[Thread trimming device]
The double chain stitch sewing machine 100 has a knot that is formed by cutting the needle thread T11 and the looper thread L of the sewing needle 11 located on the left side (most in the protruding direction of the looper 13) at the end of the sewing and tying them together. A knotter device 50 as a forming device, and a yarn locking device 70 for capturing the left needle thread T11 and the looper thread L in advance and drawing them to the knotter device 50 side in order to perform thread trimming and knotting by the knotter device 50. And a thread trimming device 75 for cutting the right needle thread T12.

The thread trimming device 75 has a loop T21a of a needle thread T2 formed with the looper 13 protruding most to the left after the needle drop of the final needle and the sewing needles 11 and 12 being stopped at the top dead center position. Capture and cut. For this reason, as shown in FIG. 6, the thread trimming device 75 has a hook knife 76 instructed to be able to reciprocate along the Y-axis direction at the nearest position above the looper 13, and a needle thread in cooperation with the hook knife 76. A fixed knife 77 that cuts T2 and an air cylinder 78 (see FIG. 14) serving as an actuator that provides the reciprocating motion of the hook knife 76 are provided.
The hook knife 76 is provided with a return claw at the tip, and the tip of the hook knife 76 enters the loop T21a of the needle thread T2 and then retreats to the right, with the looper 13 of the loop T21a interposed therebetween. The part can be captured and pulled to the fixed knife 77 side.
The fixed knife 77 is provided with an edge that comes into sliding contact with the needle thread T2 drawn during the retreating movement and cuts. The thread trimming device 75 is controlled to perform thread trimming after the thread trimming and knotting by the knotter device 50 is performed.

[Thread locking device]
7 is a plan view of the knotter device 50 and the thread locking device 70, and FIG. 8 is a side view thereof.
The thread locking device 70 is formed in a state where the looper 13 protrudes to the left most after the last needle drop and the sewing needles 11 and 12 are stopped at the top dead center position (stopped in the state of FIG. 2). The loop T11 of the needle thread T1 and the loop L11 of the looper thread L are captured. Therefore, as shown in FIG. 7, the yarn locking device 70 includes a hook member 71 that moves forward and backward in the vicinity of the looper 13 and an air cylinder 72 that serves as an actuator that gives the hook member 71 forward and backward movement. Yes.

The hook member 71 is a rod-like body along its forward / backward movement direction, and a hook catch 71a for catching a thread having a return structure is formed at the tip. The hook member 71 is disposed so as to be substantially parallel to the looper 13 in a plan view and to be inclined downwardly in a side view.
The hook member 71 enters the inside of the loop L11 of the looper thread L and the loop T11 of the needle thread T1 when the hook member 71 is advanced to the right, and the hook claw 71a that protrudes to the lower left when retracted to the left is the looper thread. In the loop L11 of L, the portion of the looper 13 extending from the eye of the looper 13 to the fabric and the portion of the needle thread T1 extending from the looper 13 to the fabric W are caught in a hooked state, and the looper thread L and the needle thread T1 are Pull out in a bundled state.

[Knotter device]
FIG. 9 is a side view showing the entire knotter device 50. As illustrated, the knotter device 50 includes a knotter 60 that captures the needle thread T1 and the looper thread L drawn by the above-described thread locking device 70, and a rotation motor as a rotation driving unit that imparts a rotation operation to the knotter 60. 51, an air cylinder 52 serving as an actuator for applying an advancing / retreating operation to the knotter 60 along the rotation center line C, and a yarn cutting and knotting operation of the knotter 60 by rotation applied from the rotary motor 51. The cam mechanism 53 includes a needle thread T1, a looper thread L, and a pair of guide plates 58 and 59 as a pair of guide members for guiding them to positions suitable for thread cutting and thread knotting.

As shown in FIG. 10 which is an exploded perspective view of the knotter 60, a yarn winding which is a claw-like member extended while gradually bending outward in the rotational radial direction along the rotation center line C. A member 61, a clamp member 62 provided adjacent to the thread winding member 61, and a fixed knife 63 provided adjacent to the clamp member 62. The fixed knife 63 is attached to the thread winding member 61 with the clamp member 62 interposed therebetween. On the other hand, they are connected by screws (not shown).
The yarn winding member 61 includes a columnar base portion 61 a centering on the rotation center line C and a yarn catching portion 61 b that is bent from the base portion 61 a and extends so as to be tapered, and the base portion 61 a has a coupling 64. To the output shaft of the rotary motor 51.
The clamp member 62 is provided so as to be rotatable with respect to the yarn winding member 61 and the fixed knife 63 via a shaft member 61c.
The fixed knife 63 has a blade 63a at the side edge of the extending portion, and can be cut by inserting a thread between the side edge of the clamp member 62 that rotates.
The clamp member 62 and the fixed knife 63 extend in the same direction while being bent in the same manner as the yarn winding member 61, and these can be integrally overlapped.

FIG. 11 is an enlarged side view in which a part of the tip portion side of the knotter device 50 is cut away, and FIG. 12 is an enlarged front view.
The cam mechanism 53 includes a round bar-shaped cam follower 54 fixedly mounted on the opposite side of the extending end of the clamp member 62, and a substantially semicircular outer peripheral cam 55 with which the inner portion of the cam follower 54 is in sliding contact The cam follower 54 includes an inner peripheral cam 56 that is in sliding contact with the outer portion.
The knotter 60 is normally rotated in the clockwise direction as indicated by an arrow in FIG. Hereinafter, this rotation direction is defined as forward rotation, and the reverse rotation direction is defined as reverse rotation.
12, P0 to P2 indicate positions of the cam follower 54, P0 is a standby position of the cam follower 54, P1 is an opening start position of the clamp member 62, and P2 is an opening completion position.
When the cam follower 54 is at the opening start position P1, it is closest to the rotation center line C, and the clamp member 62 is completely closed. When the forward rotation is applied to the knotter 60 from the opening start position P <b> 1, the cam follower 54 comes into sliding contact with the outer periphery of the outer cam 55.
The outer peripheral cam 55 is formed so that the outer peripheral radius from the rotation center line C gradually increases in a 180 ° section from the opening start position P1 to the opening completion position P2 in the forward rotation direction. Thus, the clamp member 62 can be changed from the closed state to the fully opened state.
On the other hand, the inner peripheral cam 56 is formed so that the inner peripheral radius from the rotation center line C gradually decreases in the middle of a 180 ° section from the opening end position P2 to the opening start position P1 in the forward rotation direction. Thus, the clamp member 62 can be changed from the fully opened state to the closed state.
The standby position P0 is set to have the same distance from the rotation center line C as the opening start position P1, and the rotation motor 51 is rotated backward by 180 ° with the cam follower 54 at the opening start position P1. As a result, the cam follower 54 can be moved to the standby position P0.
That is, the standby position P0 is a position for turning the tip of the knotter 60 downward with the clamp member 62 closed. The outer peripheral cam 55 is formed with a recess 55a into which the cam follower 54 at the standby position P0 is fitted.

FIG. 13 is a plan view of the guide plate 58. Each of the pair of guide plates 58 and 59 is a flat plate body, and has guide portions 58a and 59a cut out in a slit shape at the leading end portion in the advancing movement direction of the knotter device 50.
Each of these guide portions 58a and 59a is formed in parallel to the rotation center line C direction, and the tip portion thereof is expanded.
7 and 8, the knotter device 50 is located above the thread locking device 70, and like the hook member 71 of the thread locking device 70, the knotter 60 and the guide plates 58 and 59 are provided. It is arranged to advance to the right. Further, the knotter device 50 has the needle thread drawn out to the hook member 71 of the thread locking device 70 when the knotter 60 and the guide plates 58 and 59 are inclined slightly downward and the guide plates 58 and 59 are advanced. The arrangement is set so that T1 and the looper yarn L can be guided into the guide portions 58a and 59a.
Also, as shown in FIG. 12, the guide portions 58a and 59a are formed offset with respect to the rotation center line C in the width direction (X direction orthogonal to the rotation center line C) of the guide portions 58a and 59a. Yes. As a result, the loop T11 of the needle thread T1 and the loop L11 of the looper thread L spanned between the two guide portions 58a and 59a can always be held at a fixed position with respect to the knotter 60.
Further, a slit is formed deeper in the direction of the guide portion 59a of the lower guide plate 59 than the guide portion 58a of the upper guide plate 58, whereby, as shown in FIG. 11, the two guide portions 58a, 59a The loop T11 of the needle thread T1 and the loop L11 of the looper thread L that are stretched between them are inclined with respect to the rotation center line C. By inclining the needle thread T1 and the looper thread L in this way, the needle thread T1 and the looper thread L are not reached when the tip of the knotter 60 faces upward. Further, when the tip of the knotter 60 is directed downward, the clamp member 62 is opened by the outer peripheral cam 55, but the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are fixed to the thread winding member 61 (fixed). The depths of the guide portions 58a and 59a are set so as to be positioned between the knife 63) and the clamp member 62.

[Sewing machine control system]
As shown in FIG. 14, the double chain stitch sewing machine 100 includes a control device 90 as an operation control means for controlling the operation of each part and each member described above. The control device 90 includes a CPU 91 that stores and executes various control programs and sewing pattern data.
The CPU 91 is connected to a sewing machine motor drive circuit 15 a that drives the sewing machine motor 15 via the interface 15 b and controls the rotation of the sewing machine motor 15.
Further, the CPU 91 is connected to a rotary motor drive circuit 51a that drives the rotary motor 51 via the interface 51b, and controls forward / reverse rotational drive, stop position, and the like of the knotter 60.
Further, the CPU 91 is connected to drive circuits 52a, 72a, 78a for driving the air cylinders 52, 72, 78 of the knotter device 50, the thread locking device 70 and the thread trimming device 75 via the interfaces 52b, 72b, 78b. The air cylinders 52, 72, 78 are operated at a predetermined timing.
The CPU 91 is connected to an operation pedal 92 through which an operator inputs sewing start and end via an interface 92a.
Further, the CPU 91 is connected to a reverse completion switch 93 as a micro switch for detecting that the knotter 60 has completed reverse at the end of sewing through the interface 93a.

[Description of sewing operation with thread trimming and thread knotting]
Next, with respect to the thread trimming and thread knotting operation at the end of sewing in the double chain stitch sewing machine 100 having the above-described configuration, the flow chart showing the operation control of the control device 90 in FIG. 15 and the operation explanatory diagrams in FIGS. I will explain later.
First, the control device 90 determines whether or not the operation pedal 92 has been depressed (step S1). When the operation pedal 92 has been depressed, the sewing machine motor 15 is started to start sewing (step S3). That is, when the sewing machine motor 15 starts to be driven, the above-described double chain stitch sewing operation shown in FIGS.

Next, the control device 90 determines whether or not the depression of the operation pedal 92 has been released (step S5), and when the depression has been released, stops the driving of the sewing machine motor 15 (step S7).
At this time, as shown in FIG. 2, after the needle drop of the final needle, the control device 90 causes the looper 13 to protrude most to the left, and the sewing needles 11 and 12 become the top dead center position. The motor 15 is stopped.

Then, the control device 90 determines whether or not the operation pedal 92 has been depressed (step 8), and repeats the same determination until the depression is performed. When the stepping back is performed, the air cylinder 72 of the thread locking device 70 is operated to advance and retract the hook member 71, and the loop T11 of the needle thread T1 formed by the final needle Pull out the loop L11 of the looper yarn L to the left of the looper 13 (step S9: see FIGS. 7 and 8).
In this state, the control device 90 operates the air cylinder 52 of the knotter device 50 to advance the knotter 60 and the guide plates 58 and 59. As a result, the needle thread T1 and the looper thread L forming the loop T11 and the loop L11 are suspended between the guide portions 58a and 59a of the two guide plates 58 and 59 (step S11: see FIG. 16). ). In the initial state of the knotter device 50, the cam follower 54 is positioned at the standby position P0 (the cam follower 54 is fitted in the recess 55a), and the tip of the knotter 60 is closed downward. .

  From this state, the drive of the rotary motor 51 is started in the normal rotation (step S13). As a result, the cam follower 54 moves to the opening start position P1 (a state in which the tip of the knotter 60 faces directly above). During this time, the cam follower 54 does not move in the radial direction, and the knotter 60 maintains the clamp member 62 closed. Further, the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are captured at the tip of the closed knotter 60, and are wound around the tip of the knotter 60 by a half turn until reaching the opening start position P1. (See FIG. 17).

Further, the forward rotation of the rotary motor 51 is continued, and the cam follower 54 is brought into sliding contact with the outer periphery of the outer peripheral cam 55 and moves from the clamp member opening start position P1 toward the opening completion position P2. During this time, the cam follower 54 comes into sliding contact with the outer periphery of the outer cam 55 and moves gradually away from the rotation center line C toward the radially outer side, and the knotter 60 starts to gradually open the clamp member 62 ( FIG. 18 and FIG. 19).
Then, the cam follower 54 reaches the opening completion position P2 (a state in which the tip of the knotter 60 is directed downward), and the clamp member 62 is fully opened. Further, the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are wound around the tip of the knotter 60 by one turn (see FIG. 20).

Further, the forward rotation of the rotary motor 51 is continued, and the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are started to be wound around the tip of the knotter 60 at the second turn. Since 62 is opened to the maximum extent, the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are wound in a state of being interposed between the thread winding member 61 and the fixed knife 63 and the open clamp member 62 ( (See FIG. 21).
Further, when the rotation of the rotary motor 51 is continued, the cam follower 54 slides in contact with the inner periphery of the inner peripheral cam 56 and moves gradually closer to the inside in the radial direction from the rotation center line C. 62 is gradually closed. In the process of closing the clamp member 62, the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are sandwiched between the clamp member 62 and the thread take-up member 61 and fixed between the clamp member 62 and the fixed knife 63. Since the knife 63a is formed on the knife 63, the needle thread T1 and the looper thread L are cut (see FIG. 22).

Further, when the rotation of the rotary motor 51 is continued, the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are further sandwiched between the clamp member 62 and the thread winding member 61 (see FIG. 23). The cam follower 54 stops the rotary motor 51 immediately before reaching the opening start position P1, and stops the knotter 60 at the stop position (step S15: FIG. 23). This stop position is a state in which the tip of the knotter 60 faces upward, and it is desirable that the tip of the knotter 60 be closest to the guide portion 58a of the guide plate 58.
At this time, as shown in FIG. 23 (C), the needle thread T1 and the looper thread L are wound around the tip of the knotter 60 for one round, and their cut ends (sewing end ends) T13, L12 is in a state of being clamped by the yarn winding member 61 and the clamp member 62 inside the annular portion formed by winding.

With the knotter 60 stopped at the stop position, the air cylinder 52 of the knotter device 50 is operated to move the knotter 60 and the guide plates 58 and 59 backward (step S16). When the knotter 60 moves backward, the loop T11 of the needle thread T1 and the loop L11 of the looper thread L in the state of FIG. 23 (C) are released from the unclamped annular portions around the cut ends T13 and L12. As a result, the cut ends T13 and L12 are drawn into the inside of the annular portion, and are brought into a solid state (see FIG. 24).
When the knotter 60 is further moved backward, the clamped end portions T13 and L12 can also be pulled out from between the yarn winding member 61 and the clamp member 62 (see FIG. 25).

On the other hand, the control device 90 waits for detection of a reverse completion switch 93 indicating that the knotter 60 has completed reverse movement (step S17). The knotter 60 is rotated in the reverse direction to return the cam follower 54 to the standby position P0 (step S19: see FIG. 26).
Due to the reverse rotation of the knotter 60, the cam follower 54 does not move radially outward from the rotation center line C, but fits into the recess 55a, which is the standby position P0, with the clamp member 62 closed. The motor 51 stops (step S21: see FIG. 27).
Then, the air cylinder 78 of the thread trimming device 75 is operated to advance and retract the hook knife 76, and the needle thread T2 is cut (step S23).
Then, the sewing operation is completed.

The thread trimming operation of the needle thread T2 of the thread trimming device 75 may be executed at any timing after the thread knotting between the needle thread T1 and the looper thread L is completed. For example, it may be performed before step S19 or in parallel.
In addition, if the stepping motor or the like is used for the rotary motor 51, the cam follower 54 of the knotter 60 can be controlled to stop at the standby position P0, the stop position of FIG. 24, etc. by counting the number of steps. Is possible. As another method, a sensor for detecting each stop position may be provided in the knotter 60, and the rotation may be controlled to be stopped by the detection.
In the sewing machine 100, after the loop T11 of the needle thread T1 and the loop L11 of the looper thread L are cut, the air kinder 52 is operated to move the knotter 60 backward, thereby completing the thread knot. Alternatively, a yarn wiping mechanism for the looper yarn L may be provided, and the yarn knot may be executed by automatic control.

[Technical effect]
FIG. 28 is a view of the needle thread T1 and the looper thread L tied by the knotter device 50 as viewed from the back side of the fabric W. Thus, in the double chain stitch sewing machine 100, the knotter device 50 can cut the needle thread T1 and the looper thread L of the sewing needle 11 on the advancing direction side of the looper 13 and tie the cut ends together. Therefore, even when the looper thread L is pulled, it is tied to the needle thread T1, so the looper thread L does not come out of the loop T11 of the needle thread T1 and fraying of the seam does not occur. Further, as long as the looper thread L does not come off from the loop T11 of the needle thread T1, the looper thread L is prevented from coming off from the loop T21 of the needle thread T2. Therefore, fraying of the seam does not occur from the cutting step portion of the needle thread T1 and the looper thread L, so that the seam can be more reliably maintained.

  Further, since the knotter device 50 performs thread trimming of T13 and L12, which are sewing end ends of the needle thread T1 and the looper thread L, a dedicated thread trimming apparatus for the needle thread T1 and the looper thread L can be eliminated. . Further, the knotter device 50 continuously performs thread trimming and thread knotting of the needle thread T1 and the looper thread L at T13 and L12, so that the end of the needle thread T1 and the looper thread L after thread trimming. The parts T13 and L12 are not separated, and it is possible to perform these yarn knotting operations more reliably without failing.

  In addition, prior to the thread trimming and knotting operation of the knotter device 50, the yarn locking device 70 binds and captures the looper yarn L and the needle thread T1, so that the guide portions 58a of the guide plates 58, 59 of the knotter device 50, It becomes easy to guide the looper thread L and the needle thread T1 to 59a, and it becomes possible to more easily and surely perform the operation of connecting T13 and L12 which are the sewing end ends.

[Other examples of double chain stitching (1)]
As shown in FIG. 29, in the seam of FIG. 39 formed by the seam forming device described in Japanese Patent No. 3318482, the needle thread T1 and the looper thread L of the sewing needle 11 at the end of the looper 13 in the advancing direction are provided. It is also possible to tie the cut end (sewing end). The method will be described below.
A looper thread engagement hook 101 that can be rotated by an actuator shown in FIG. 30 is provided near the needle drop position of the sewing needle 11 between the needle plate and the looper 13.
Then, after the last needle drop, the sewing needles 11 and 12 are stopped at the top dead center position, and the looper 13 is stopped at the most advanced position.
In this state, as shown in FIG. 31, the looper thread engagement hook 101 is rotated to capture the loop L11 of the looper thread L at a position closer to the looper tip than the loop T11 of the needle thread T1.
Further, as shown in FIG. 32, the looper 13 is retracted and the sewing machine motor 15 is driven again to execute another needle drop by the sewing needles 11 and 12, and the looper thread engagement hook 101 is captured. The needle drop of the sewing needle 11 is performed on the loop T11.
Again, the sewing needles 11 and 12 are stopped at the top dead center position, and the looper 13 is stopped at the re-advance position.
33, the thread locking device 70 advances the hook member 71 and captures the looper thread L and the needle thread T1. At this time, the looper thread L passes through the eye of the looper 13. The loop L11 captured by the looper thread engagement hook 101 and the loop T14 of the needle thread T1 formed by performing a new needle drop are captured and pulled out, not the portion over the fabric W. The hook member 71 of the thread locking device 70 is preferably adjusted so that its reciprocating movement trajectory and the direction of the claw 71a are suitable for capturing the loop T14 of the needle thread T1 and the loop L11 of the looper thread L. .
Then, as shown in FIG. 34, with respect to the loop T14 of the needle thread T1 and the loop L11 of the looper thread L drawn by the thread locking device 70, the yarn end portion It is possible to form the knot shown in FIG. 29 by executing the cutting and knotting.

[Other examples of double chain stitching (2)]
FIG. 35 shows a double chain stitch sewing machine having only one sewing needle 11, and in the double chain stitch that is formed by alternately passing the loop with the needle thread T 1 and the looper thread L, the thread is made by the knotter device 50. The stitches when cutting and tying are executed are shown. In this case, the knotting shown in FIG. 35 can be executed by the knotter device 50 and the yarn locking device 70 shown in FIGS.
Further, FIG. 36 shows a double chain stitch sewing machine having only one sewing needle 11, and the loop of the needle thread T1 is captured by the looper thread engagement hook 101 shown in FIGS. The stitches when thread cutting and thread knotting are performed after needle entry is shown. Also in this case, the yarn knot shown in FIG. 36 can be executed by using the yarn locking device 70 and the knotter device 50 shown in FIGS.

[Other examples of knotter devices]
FIG. 37 shows an example in which a protruding portion 58b as an extending portion extending from the lower surface of the guide plate 58 toward the rotation center line C side is formed in the guide portion 58a of the upper guide plate 58 of the knotter device 50. .
The protrusion 58 b extends at least the tip of the protrusion 58 b to the inside of the radius of rotation at the tip of the knotter 60.
As a result, the needle thread T1 and the looper thread L spanned over the guide portions 58a and 59a can be more reliably captured at the tip of the knotter 60.

[Others]
The present invention is not limited to the above embodiment. For example, the number of sewing needles of the double chain stitch sewing machine may be one or three or more. When there are three or more sewing needles, it is desirable to tie the end of the sewing end of the needle thread and looper thread of the sewing needle closest to the forward movement direction of the looper 13.
In addition, the knotter device 50 is also provided in the case where a well-known spreader mechanism for manipulating a decorative thread on the sewing needle is provided and decorative sewing which is a kind of double chain stitching in which a decorative thread is sewn into a double chain stitch stitch. It is possible to apply.

11, 12 Sewing needle 13 Looper 50 Knotter device (knot forming device)
51 Rotating motor (Rotating drive)
53 Cam mechanism 58a, 59a Guide part 58b Protrusion part 60 Notter 61 Thread winding member 62 Clamp member 63 Fixed knife 70 Thread locking device 71 Hook member 100 Double chain stitch machine C Rotation center line L Looper thread L11 Looper thread loop T1 , T2 Needle thread T11, T21 Needle thread loop T13, L12 Cutting end (end of sewing)
W Fabric (Sewing product)

Claims (6)

A feed mechanism for transporting the workpiece in a certain direction;
A needle up-and-down movement mechanism for moving the sewing needle up and down;
A looper mechanism for moving the looper forward and backward along a direction intersecting the conveyance direction of the sewing product,
In the double chain stitch sewing machine that performs double chain stitch,
A knot forming device for connecting the end ends of sewing of the needle thread and the looper thread ;
A thread locking device having a hook member that binds and captures the looper thread and the needle thread;
The double knot sewing machine characterized in that the knot forming device forms a knot on the looper yarn and the needle yarn captured by the yarn locking device . A feed mechanism for transporting the workpiece in a certain direction;
A needle up-and-down movement mechanism for moving the sewing needle up and down;
A looper mechanism for moving the looper forward and backward along a direction intersecting the conveyance direction of the sewing product,
In the double chain stitch sewing machine that performs double chain stitch,
It has a knot forming device that connects the end ends of the needle thread and looper thread ,
The knot forming device includes:
A yarn winding member supported rotatably and extending in a direction deviating from the rotation center line from the rotation center;
A clamp member that is attached to the yarn winding member and is rotatably provided to the yarn winding member;
A fixed knife attached to the clamp member;
A rotational drive unit that integrally imparts a rotational motion to the yarn winding member, the clamp member, and the fixed knife;
A double chain stitch sewing machine , comprising: a cam mechanism that imparts a rotating motion to the clamp member during rotation by the rotation driving unit . The knot forming device includes a pair of guides that support the needle thread and the looper thread in a state in which the needle thread and the looper thread are slanted with respect to the rotation center line of the thread winding member so as to pass through the capture range of the thread winding member. The double chain stitch sewing machine according to claim 2, further comprising a portion. The knot forming device, one of said guide portion, according to claim 3, characterized in that by extending to the inside of the turning radius of the tip of the line winding member toward the rotation center side of the winding member Double chain stitch sewing machine. The knot forming device, to any one of claims 1 4, characterized in that the tie operation of thread cutting and the sewing end edge of the sewing end end side of the looper thread and the needle thread The double chain stitch sewing machine described. A plurality of the sewing needles are provided in a state of being aligned along the advancing / retreating movement direction of the looper,
The knot forming device from claim 1, characterized in that connecting the needle thread of the needle to be positioned at the front end side of the most the looper when the looper is the most prominent, the sewing end edge portions of the looper thread The double chain stitch sewing machine according to claim 5.

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