JP3866325B2 - sewing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewing machine used for sewing or the like.
[0002]
[Prior art]
In general, in a sewing machine, the needle thread is inserted into the cloth to be stitched up and down while the upper thread is passed through the needle hole of the needle that moves up and down, and the upper thread passed through the needle hole is the fabric. The lower thread is entangled with the upper thread from the lower side of the fabric by a hook or looper while penetrating from the upper side to the lower side.
[0003]
By repeating this operation of entwining the upper thread and the lower thread while feeding the fabric, a series of stitches are formed from the upper thread and the lower thread, and the fabrics are sewn together.
[0004]
As described above, after forming a series of stitches from the upper thread and the lower thread, the upper thread and the lower thread are cut by the thread trimming knife below the needle plate to prepare for the next series of stitches.
[0005]
Here, as described above, the upper thread after thread trimming with the thread trimming knife usually varies in length, and if the length from the needle hole is too short, the end of the upper thread will become the fabric during the next sewing. There is a problem of falling out of.
[0006]
On the other hand, although not known at the time of the present application, according to Japanese Patent Application No. 7-212132, a knot is formed in the upper thread after cutting, so that the end of the upper thread does not come off from the fabric at the next sewing. Something like this has been proposed.
[0007]
However, in this case, there is a variation in the position from the needle hole of the knot, and if the distance from the knot to the needle hole is too long, the knot will not reach the fabric, and it is in a complicated state called a bird's nest If the distance from the knot to the needle hole is too short, there is a problem that the fabric is excessively tightened when the seam is formed. Furthermore, since the knot is formed at a position between the end portion of the upper thread and the needle hole, there is a problem that the portion from the knot to the thread end becomes long and the thread may be wasted.
[0008]
Further, as a countermeasure for preventing the cut upper thread from coming off from the fabric at the next sewing, there is one in which the length from the needle hole to the thread end is controlled.
[0009]
However, in this case, at the next stitch formation, even if the amount of protrusion of the upper thread end from the fabric is appropriate up to the first or second stitch, the upper thread will be formed each time a further stitch is formed. Is pulled by the lower thread little by little, and the upper thread end is pulled out to the lower or upper side of the fabric, and the upper thread end that has been pulled out is sewn into the lower thread, or a so-called bird's nest state is formed. There is a problem that.
[0010]
In addition, there is a means to securely stop the upper thread end on the fabric by so-called reverse stitching at the start of sewing, but in this case, there remains a problem that the appearance of the sewing start portion is poor.
[0011]
On the other hand, according to Japanese Patent Application No. 7-337049 (unknown), the present applicant forms a knot from the needle hole to the upper thread end at a predetermined length position after a series of stitches is completed. A thread sewing method and a sewing machine using a sewing machine that prevents excessive tightening of the fabric and the like at the next sewing, and deterioration of the appearance due to a long thread end, have been proposed.
[0012]
This is because a sewing machine is used to sew a needle thread on the needle of the sewing machine and a lower thread to be entangled with the needle thread into a sheet-like article, and then the needle and the sheet-like article. The upper thread is cut at a predetermined length position from the needle, and the needle side end of the cut upper thread is grasped, and a knot is formed in the vicinity of the needle side end. A series of stitches are performed.
[0013]
That is, the upper thread is cut from the needle at a predetermined length position, and a knot is formed at the end thereof, so that the distance from the knot needle can be made constant, so that the fabric can be sewn at the next sewing. The knot can be tightly attached with an appropriate tension to prevent excessive tightening of the fabric by the knot, and the tip side from the knot is cut off, so that the appearance of the sewing start portion does not deteriorate.
[0014]
Here, the knot is gripped by the needle side end of the cut upper thread to form a ring, and the ring is gripped by lowering the first needle during the next series of stitches. And formed by pulling the opposite side.
[0015]
Specifically, the sewing machine grasps the upper thread at a position between the needle and the sheet-like material after a series of stitches is finished, and pulls the upper thread in a lateral direction by pulling it to the side of the needle. A thread gripping device that is stretched over and a position that comes into contact with the upper thread stretched by the thread gripping device, tangling the upper thread to form a ring, and cutting the thread gripping device side of the ring, And a yarn knot device for grasping an end portion of the cut upper thread on the needle side and forming a knot through the ring.
[0016]
In addition, the yarn knotting device is bent about 90 ° continuously from the rotation shaft rotatable about the rotation center axis substantially orthogonal to the upper thread stretched by the yarn gripping device, and the tip of the rotation shaft. A thread knot including an extended claw portion is provided, and the upper thread is wound around an inner corner from the rotation shaft to the claw portion, and the rotation shaft is rotated to wind the rotation shaft. By forming an upper thread ring, an upper thread ring wound around the rotation shaft is formed.
[0017]
Further, the claw portion of the thread knot is substantially overlapped with the claw body, an open position where the tip end side can be opened and closed with respect to the claw body, and is opened to the extent that the upper thread enters. And a clamp portion supported so as to be swingable so as to be able to take a closed position. The upper thread that is wound around the rotation shaft to form a ring can be gripped. The tip of the claw portion is arranged at a position where the upper thread can be removed by the vertical movement of the needle at the end of thread tying, thereby forming an upper thread loop around the rotating shaft.
[0018]
Further, the upper thread is parallel to the rotation axis of the thread knot and in the tip direction at a position where it can contact the stretched upper thread between the needle and the thread knot. There is provided a yarn hooking device for displacing and hooking the upper thread by bending it toward the tip of the hook at the inner corner of the yarn knot.
[0019]
Furthermore, the yarn hooking device is movable substantially parallel to the rotation axis of the yarn knot, and the yarn hooking claw pushes the upper thread in the direction of the rotation shaft tip between the needle and the yarn knot. And an actuator for driving the yarn hooking claw, wherein the yarn hooking claw is at least an amount of the upper thread pushed out and an upper thread pushing position between the needle and the thread knot. One is adjustable.
[0020]
Here, after the upper thread is displaced by the thread hooking device, the inner knot is rotated to an angular position where the inner corner portion is in contact with the stretched upper thread, The actuator includes a cylindrical cam that is disposed in parallel with the rotation shaft and drives a cam follower provided on the yarn hooking claw by a tip cam surface. The cam surface waits for the yarn hooking claw. When the cylindrical cam is rotated in the forward direction, the cam follower is driven from the cam groove to the cam surface and only when the cam follower is rotated in the reverse direction. It is supposed to enter.
[0021]
[Problems to be solved by the invention]
In a sewing machine equipped with the above-described yarn knotting device, the upper thread held by the thread grasping device is entangled with the yarn knotting device to form a ring. At this time, the upper thread is moved from the needle direction by the yarn knotting device. The thread is pulled out by the size of the ring, and the thread amount of the pulled-out part is compensated by first shortening the thread path by bending the thread take-up spring in the thread tensioner.
[0022]
The amount of thread that cannot be compensated for by this thread take-up spring is fed out from the thread tensioner, but the fed-out thread lengthens the needle thread length (the amount of thread fed out by the thread take-up spring is After the thread is formed, the thread take-up spring is pulled back, so that it becomes impossible to form a knot, or at the beginning of sewing, a lump of thread called a bird's nest is formed on the upper surface of the sheet-like material. This causes a problem that it occurs.
[0023]
This can be solved by making the stroke of the thread take-up spring equal to the size of the thread ring when the knot is formed by the thread knot device, but in this way, the tension of the thread take-up spring and the thread tensioner The tension of the thread tensioner, the strength of the tension of the thread tensioner, the twist of the thread, the size, the elongation, etc. cause a new problem that the thread tension spring is often unwound from the thread tensioner. .
[0024]
In the sewing machine, when the upper thread is pulled by the needle at the start of sewing, the loop of the upper thread comes out of the thread knotting device and is tightened to complete the knot. Also, at this time, the yarn path from the thread tensioner to the yarn knot device through the needle is lengthened by the lowering of the needle, whereby the upper thread is pulled and the distance from the needle to the knot is shortened. Can prevent the formation of nests.
[0025]
However, if the tension of the thread tensioner is weak at this time, the upper thread is fed out from the thread tensioner and the upper thread is compensated for the descending stroke when the needle is lowered. It will not be replenished from the device side.
[0026]
Therefore, there is a problem that the thread loop does not come off from the thread knot device side, and the knot is not completed, or even if the knot is formed, the distance from the needle becomes long and the occurrence of bird nest cannot be prevented. Arise.
[0027]
Furthermore, for example, when a needle thread pull-back device is provided and a knot is formed, the thread path between the thread tensioner and the thread knot device is lengthened, and as a result, the thread remaining length from the needle is shortened, It is conceivable that the knot is formed properly. At this time, when the thread path is lengthened by operating the needle thread pull-back device, if the thread take-up spring force is weak, the thread take-up spring is bent to cause a short upper thread. This causes a problem that the thread loop cannot be removed from the thread knotting device and the knot cannot be formed.
[0028]
Furthermore, after the knot is formed, if the sewing machine further rotates and the needle thread lowers and the upper thread pulling of the balance causes the upper thread path to become longer, the shortage amount of the upper thread increases and is clamped by the thread knotting device. The yarn end on the knot side is pulled strongly and may come off from the yarn knot device.
[0029]
However, the yarn end is not clamped by the yarn knotting device while the upper yarn is hooked by the hook for entwining the lower yarn with the upper yarn on the back side of the sheet-like material, and the knot is formed on the sheet-like material. This causes the problem that the stitches are not formed from the first stitches at the start of sewing.
[0030]
Further, for example, the thread gripping device may need to be provided at a position far from the needle in order to improve sewing workability.
[0031]
However, since the remaining length of the upper thread after a series of stitches is finished is determined by the position of the knife located below the sheet-like material, the distance between the thread gripping device and the needle is as described above. There is a limit due to the remaining length of the upper thread, and it cannot be over a certain distance.
[0032]
In order to solve this problem, it is conceivable to increase the remaining length of the needle thread by weakening the pre-tension at the time of sewing. If the distance of the knot is far from the needle after the thread knot is completed, the upper thread becomes excessive at the beginning of sewing and becomes a bird's nest.
[0033]
Furthermore, in the sewing machine, the upper thread stretched between the needle and the needle by the thread gripping device is pushed out by the thread hooking device, and in this state, the upper thread is entangled to form a ring. The upper thread is clamped and cut by the rear thread knot, but when the upper thread is formed by the thread knot, the upper thread is pulled out from the direction of the thread tensioner by being wound around the thread knot. It is.
[0034]
At this time, clamping and cutting of the yarn by the yarn knot are performed at a position (a position returned to the needle direction) further rotated after the yarn knot once pulls the upper thread to the maximum from the needle. Therefore, the upper thread is loosened by the amount returned by the rotation.
[0035]
At this time, if the yarn amount supplied by the rotation of the yarn knot is all supplied from the thread take-up spring, the slack is absorbed by the return of the thread take-up spring, but the thread tensioner exceeds the stroke of the thread take-up spring. The amount of yarn supplied from the yarn causes slack, which causes a problem that it becomes difficult to cut the upper yarn with the yarn knot.
[0036]
The present invention has been made in view of the above-described problems, and provides a sewing machine that can prevent the upper thread from being fed out from a thread tensioner when an upper thread loop is formed by a yarn knotting device. With the goal.
[0037]
In addition, when a knot is formed by a yarn knotting device, a sewing machine is provided that prevents the knot from being formed in the yarn knotting device by making the upper yarn fed out from the thread tensioner and replenishing the yarn. The purpose is to do.
[0038]
Furthermore, when forming the knot in the yarn knot device by pulling back the upper thread with the needle thread pull-back device, the thread take-up spring is stopped so that the upper thread is supplemented from the thread take-up spring so that knot formation is not disabled. The sewing machine prevents the knot from coming out of the back of the sheet-like material when the upper thread is hooked on the hook on the lower side of the sheet-like material. The purpose is to provide.
[0039]
Even if the thread clamp device is moved away from the needle to improve the sewing workability, the upper thread can be pulled by the thread clamp device without the upper thread becoming a bird's nest at the beginning of the next sewing. An object is to provide a sewing machine.
[0040]
Also, when the upper thread end is cut by the thread knot of the thread knot, the upper thread loosening due to the return of the thread knot is absorbed so that the upper thread is always stretched between the needle and the thread clamp device. An object of the present invention is to provide a sewing machine that ensures cutting.
[0041]
[Means for Solving the Problems]
In this invention, an upper thread to be hung on a needle and a lower thread to be entangled with the upper thread are sewn into a sheet-like material, and the upper thread is supplied to the needle through a thread tensioner provided with a thread take-up spring. In the sewing machine, after the series of stitches is finished, the gap between the needle and the sheet Upper thread Hold the needle and pull it to the side of the needle. Diagonally upward from the needle hole of the needle A thread clamp device that is stretched, and a position that comes into contact with the upper thread stretched by the thread clamp device, entangles the upper thread to form a ring, and cuts the thread clamp device side of the ring; and And a pressing member that holds at least one of the thread tension device and the upper thread upstream of the thread take-up spring by grasping the needle-side end of the cut upper thread and forming a knot through the ring. And the upper thread feeding stop device that is operated when the upper thread is entangled by the yarn knotting device to make a ring and stops the feeding of the upper thread.
[0042]
Further, according to the present invention, an upper thread to be hung on a needle and a lower thread to be entangled with the upper thread are sewn into a sheet-like material, and the upper thread is attached to the needle via a thread tensioner provided with a thread take-up spring. In the supplied sewing machine, after the series of stitches is completed, the gap between the needle and the sheet Upper thread Hold the needle and pull it to the side of the needle. Diagonally upward from the needle hole of the needle A thread clamp device that is stretched, and a position that comes into contact with the upper thread stretched by the thread clamp device, entangles the upper thread to form a ring, and cuts the thread clamp device side of the ring; and And a pressing member that holds at least one of the thread tension device and the upper thread upstream of the thread take-up spring by grasping the needle-side end of the cut upper thread and forming a knot through the ring. An upper thread feeding stop device that is activated when the upper thread is entangled by the thread knotting device at the time of lowering the needle at the start of sewing, and stops feeding of the upper thread. When the upper thread is pulled by the needle at the start of sewing, the upper thread loop is pulled out of the thread knotting device and tightened to complete the knot.
[0043]
Furthermore, an upper thread to be hung on the needle and a lower thread to be entangled with the hook by a hook are sewn into the sheet-like material, and the upper thread is supplied to the needle through a thread tensioner equipped with a thread take-up spring. In the sewing machine, after the series of stitches is finished, the gap between the needle and the sheet Upper thread Hold the needle and pull it to the side of the needle. Diagonally upward from the needle hole of the needle A thread clamp device that is stretched, and a position that comes into contact with the upper thread stretched by the thread clamp device, entangles the upper thread to form a ring, and cuts the thread clamp device side of the ring; and A thread knot device for grasping the end of the cut upper thread on the needle side and forming a knot through the ring; and the thread take-up spring can be hooked freely. In addition, the displacement of the thread take-up spring in the upper thread feeding direction is restricted, and the thread take-up spring is opened after the upper thread protruding downward from the sheet-like material by the lowering of the needle at the start of sewing is started after the retracting by the hook. A thread take-up spring stopper, and at the beginning of sewing, the upper thread is pulled by the needle so that the upper thread loop comes out of the thread knotting device and is tightened to complete the knot. To achieve the above objectives It is.
[0044]
Furthermore, according to the present invention, a series of sewing operations are performed in a sewing machine that sews an upper thread that is supplied via a thread tensioner and is hung on a needle and a lower thread that is entangled with the upper thread into a sheet-like material. After finishing, between the needle and the sheet Upper thread Hold the needle and pull it to the side of the needle. Diagonally upward from the needle hole of the needle A thread clamp device that is stretched, and a position that comes into contact with the upper thread stretched by the thread clamp device, entangles the upper thread to form a ring, and cuts the thread clamp device side of the ring; and The needle knot end of the cut upper thread is grasped and a knot is formed through the ring, and the position of the upper thread can be adjusted in the middle of the upper thread path between the thread knot and the thread tensioner. And an upper thread pull-back device including a thread guide that changes the degree of bending of the path.
[0045]
The upper thread pull-back device is configured to reduce the bending of the path immediately before the upper thread is pulled by the thread gripping device after a series of stitches is completed, and at the end of the thread tying by the thread tying apparatus. The yarn guides may be driven in the direction of increasing the bending of the yarn.
[0046]
Further, in a sewing machine that sews an upper thread that is hung on a needle and a lower thread that is entangled with the upper thread into a sheet-like material, after the series of stitches has been completed, a gap between the needle and the sheet-like material Upper thread Hold the needle and pull it to the side of the needle. Diagonally upward from the needle hole of the needle A thread clamp device that is stretched, and a position that comes into contact with the upper thread stretched by the thread clamp device, entangles the upper thread to form a ring, and cuts the thread clamp device side of the ring; and A thread tying device that grips the end of the cut upper thread on the needle side and forms a knot through the ring, and a yarn hooking device, and the yarn tying device is stretched by the thread gripping device. A rotation shaft that is rotatable about a rotation center axis substantially orthogonal to the upper thread, and a thread knot that includes a claw portion that is bent and extended approximately 90 ° continuously from the tip of the rotation shaft. The upper thread is rotated from the rotation shaft to the inner corner from the claw portion to rotate the rotation shaft, thereby forming a loop of the upper thread that winds the rotation shaft. It is arranged at a position where it can contact the stretched upper thread between the needle and the thread knot. The upper thread is displaced parallel to the rotation axis of the thread knot and in the direction of its tip, and the upper thread is bent and hooked at the inner corner of the thread knot toward the tip of the nail. The actuator includes a thread hooking claw and an actuator for driving the thread hooking claw. The actuator has a displacement amount in a tip direction of the thread hooking claw, and a rotation angle of the thread knot is determined by a path length of the upper thread. The above-mentioned object is achieved by driving the thread hooking claw to a position where the upper thread is tensioned when the thread is made the longest and when the upper thread is cut by the yarn knotting device.
[0047]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0048]
As shown in FIG. 1, the sewing machine 80 according to the present invention generally has an upper thread 14 hung on a needle 12 and a lower thread 16 entangled with the upper thread 14 sewn into a sheet-like material such as a fabric 18. After a series of stitches are finished and the upper and lower threads are cut under the needle plate, the sewing machine main body 80A has a structure between the needle 12 and the fabric 18. Upper thread 14 and pull it to the side of the needle 12 to Diagonally upward from the needle hole of the needle It is arranged at a position where it comes in contact with the thread clamp device 82 and the upper thread stretched by the thread clamp device 82, and the upper thread 14 is entangled to form a ring. A thread knotting device 84 that cuts and grasps the end of the cut upper thread on the needle 12 side and forms a knot through the ring.
[0049]
Further, it is disposed at a position where it can come into contact with the stretched upper thread 14 between the needle 12 and the thread knotting device 84, and the upper thread 14 is displaced in the forward direction (operation side) to A yarn hooking device 86 is provided for hooking the yarn to the yarn knotting device 84.
[0050]
The sewing machine 80 includes a wiper (corresponding to the swing arm 40) 88 and a clamping head (corresponding to the thread gripping claw 44) similar to the thread gripping device 82, for example, the wiper and the clamping head in the invention of JP-A-6-190177. ) 90.
[0051]
The wiper 88 is supported at the base end thereof by a rotating shaft 88A driven by an actuator (not shown) such as a solenoid, and between the needle 12 and the fabric 18 at a thread clamp hook 88B at the distal end (free end). Upper thread 14 is pulled through the vicinity of the yarn knotting device 84 to the suction port 90A of the clamping head 90.
[0052]
As shown in FIG. 1, the clamping head 90 communicates with the suction port 90A inside, and with a negative pressure path 90B communicating with a negative pressure source (not shown), and the suction port 90A in the negative pressure path 90B. And a clamping cylinder 90D that presses and separates the ball 90C from the opposite side, and sucks the yarn end of the upper yarn 14 carried by the yarn gripping hook 88B at the tip of the wiper 88 into the negative pressure path 90B. The yarn end sucked in the vicinity of the suction port 90A can be clamped by extruding the ball 90C by the clamping cylinder 90D.
[0053]
As shown in FIGS. 1 and 2, the yarn knot device 84 includes a yarn knot 92, and when the yarn knot 92 is rotated about its rotation axis 94, a clamp is made with respect to the nail portion main body 96. The portion 98 is driven to open and close by rotating in sliding contact with the inner periphery of the eccentric ring-shaped cam 100.
[0054]
The claw portion main body 96 and the clamp portion 98 are claw portions that bend and extend at a substantially right angle from the rotation shaft 94 that is rotatable around a rotation center axis substantially orthogonal to the upper thread 14 stretched by the thread gripping device 82. 102, and the upper thread 14 wraps around the upper shaft by rotating the rotating shaft 94 from the rotating shaft 94 to the inner corner portion 103 extending from the rotating shaft 94 to the claw portion 102. 14 rings can be formed. Further, as shown in FIG. 3, the clamp portion 98 is attached to the claw portion main body 96 so as to be swingable (openable and closable) by a pin 96B. At the time of opening and closing, the upper thread 14 is clamped and cut, and the upper thread end after the cutting is held.
[0055]
As shown in FIG. 3, the slit 96A of the claw portion main body 96 is wider than the thickness of the clamp portion 98, and the clamp portion 98 in the slit 96A has a slit 98A as shown in FIG. One inner surface 99A is disposed so that one surface 98B of the clamp portion 98 is in sliding contact with the clamp portion 98 when the clamp portion 98 is opened and closed, and the difference between the width of the slit 96A and the thickness of the clamp portion 98 sandwiches the upper thread 14 here. It is said that it can be.
[0056]
Further, cutting edges 99B and 98C are respectively formed at opposite corners of the inner surface 99A of the slit 96A and the surface 98B of the clamp portion 98, and as shown in FIG. The upper thread 14 sandwiched (clamped) between the portions 98 is cut by the cutting blades 99B and 98C when the clamp portion 98 is closed. Further, even after cutting, as shown in FIG. 3B, the upper thread 14 is held by the clamp portion 98 and the claw portion main body 96 in the slit 96A, and the clamped state is maintained. Here, in order to securely clamp the upper thread 14, the positional relationship between the portion of the claw portion main body 96 where the thread scissors are started and the cutting edge portion 99 </ b> B is such that the upper thread 14 first contacts the claw portion main body 96, and thereafter It is better that a deviation occurs so as to come into contact with the cutting edge portion 99B and thread trimming.
[0057]
As shown in FIG. 2, the ring-shaped cam 100 is supported on a support plate 104 on the sewing machine body 80A side by a screw 100A so as to be swingable in a plane orthogonal to the rotation shaft 94, and a solenoid. The actuator 100B is oscillated within a certain range about the screw 100A via the oscillating shaft 100C, thereby adjusting the amount of eccentricity relative to the rotating shaft 94, that is, the opening degree of the clamp portion 98 relative to the claw body 96. It is configured as follows. Reference numeral 100 </ b> D in FIG. 2 indicates a long hole formed in the ring-shaped cam 100. The rocking shaft 100C is configured such that the ring-shaped cam 100 can be driven when the hook-shaped end portion 100E engages with the long hole 100D.
[0058]
As shown in FIG. 2, the thread knot 92 is inserted into a mounting hole 106 </ b> A formed at the shaft end of the drive shaft 106 so that the axial position and the rotational position can be adjusted. It is fixed at an arbitrary position by the fixing screw 106B and can be removed.
[0059]
A pulley 106C is attached to the end of the drive shaft 106 opposite to the yarn knot 92, and the pulley 106C is driven by a pulse motor 106E via a timing belt 106D. . As shown in FIG. 4, the pulley 106 </ b> C and the pulse motor 106 </ b> E are provided on the back side of the back plate 80 </ b> C that hangs down on the back side near the base end (side away from the needle 12) of the arm portion 80 </ b> B in the sewing machine body 80 </ b> A. It is fixed to.
[0060]
The yarn hooking device 86 includes a cylindrical cam 108, and the cylindrical cam 108 is attached to the drive shaft 106 with a screw 108A so as to be coaxial and axially and rotationally adjustable.
[0061]
The yarn hooking device 86 includes a yarn hooking claw 110 which is pushed out by a cam surface 108B which is an end surface of the cylindrical cam 108 or returned by a return spring 110A.
[0062]
The thread hooking claw 110 has a thread hooking claw support plate 86A on the side of the cylindrical cam 108 which is parallel to the drive shaft 106 at a position on the needle 12 side of the cylindrical cam 108 and a pin 110B on the cylindrical cam 108 side. Is supported in a swingable manner in a plane parallel to the.
[0063]
Further, a cam follower 110C that is slidably contacted with the cam surface 108B of the cylindrical cam 108 is attached to the yarn hooking claw 110, and the swing amount in the pushing direction of the upper thread 14 is determined according to the lift amount of the cam surface 108B. It has come to be.
[0064]
The cam surface 108B of the cylindrical cam 108 is formed with a low lift surface 109A, a high lift surface 109B, and a cam groove 108C extending obliquely in the proximal direction of the drive shaft 106. The cam groove 108C is formed obliquely in the reverse direction from the cam surface 108B. When the cam follower 110C is located at the bottom of the cam groove 108C, the thread hooking claw 110 is in the standby state most retracted by the return spring 110A. State.
[0065]
Further, when the cylindrical cam 108 is rotated in the forward direction (clockwise in FIG. 2), the cam follower 110C is driven along the cam groove 108C to the low lift surface 109A of the cam surface 108B, whereby the yarn hooking claw 110 is driven. Is protruded against the urging force of the return spring 110A, pushes the upper thread 14 stretched between the needle 12 and the clamping head 90, and the cylindrical cam 108 is further rotated in the forward direction. The thread hooking claw 110 further pushes out the upper thread 14 by the 109 surface.
[0066]
As shown in FIG. 5, the amount of extrusion from the low lift surface 109A to the high lift surface 109B is such that the claw 102 pulls the upper thread 14 to the maximum (CH) and then rotates clockwise to the cutting position. 14 slacks are absorbed.
[0067]
Here, the yarn hooking device 86 includes origin detecting means 112 for detecting that the rotational position of the inlet of the cam groove 108C in the cylindrical cam 108 is in the vicinity of the origin position beyond the positive direction of the cam follower 110C. I have.
[0068]
The origin detecting means 112 includes a rotating plate 112A that rotates coaxially with the driving pulley 106F on the side of the pulse motor 106E that drives the timing belt 106D, and a notch formed at one circumferential direction of the rotating plate 112A. 112B, and a limit switch 112C that comes into rolling contact with the outer periphery of the rotating plate 112A, is turned on at the position of the notch 112B, and outputs an origin detection signal.
[0069]
The sewing machine main body 80A is provided with a thread tensioner 120 for adjusting the tension of the upper thread 14, but in the sewing machine 80, the upper thread tensioner 120 for stopping the feeding of the thread is stopped. A thread take-off stop device 122, a thread take-up spring 124 in the thread tensioner 120, and a thread take-up spring stopper 126 for restricting displacement of the thread take-up spring 124 in the upper thread take-up direction at the time of hooking, the thread tensioner 120 An upper thread pull-back device 128 disposed in the upper thread path between the needle thread 12 and the needle 12 so that the upper thread can be pulled back by changing the amount of bending of the upper thread path. ing.
[0070]
As shown in FIG. 6, the upper thread feeding stop device 122 includes a pressing lever 122A mounted on an end portion of the thread tension spring 120A in the thread tensioner 120, and the pressing lever 122A of the thread tension spring 120A. And a solenoid 122B that is driven in a direction to shorten the set length.
[0071]
The upper thread feeding stop device 122 is composed of a solenoid 122B. In Further, the pressure lever 122A is driven rightward in FIG. 6 to increase the set pressure of the thread tension spring 120A, and the upper thread 14 passing through the thread tensioner 120 is strongly pressed through the thread tension plate 120B. The feeding in the needle direction is stopped. In order to increase the needle thread tension, a linear type motor such as a known hysteresis rotary tension or voice coil motor may be applied.
[0072]
As shown in an enlarged view in FIG. 7, the thread take-up spring stopper 126 includes a stopper lever 126A that can be locked to the thread take-up spring 124, and a solenoid that drives the stopper lever 126A in a direction to lock the thread take-up spring 124. 126B, and when the solenoid is energized, the stopper lever 126A is engaged with the thread take-up spring 124, and in FIG. 7, the swinging in the counterclockwise direction, that is, the swinging in the upper thread feeding direction is restricted. Yes. Reference numeral 126C in FIG. 7 denotes a return spring.
[0073]
The upper thread pull-back device 128 includes an upper thread between the thread tensioner 120 and the needle 12, as shown in FIGS. 8 and 9 (the upper thread feeding stop device 122 and the thread take-up spring stopper 126 are not shown). In the middle of the path, the thread guide 128A is arranged so that the position can be adjusted in the vertical direction and changes the magnitude of the bending of the upper thread path, and the upper steady position indicated by a two-dot chain line in FIG. And a yarn guide driving device 128B that is driven between the upper yarn pull-back position at the lower side, that is, the position for increasing the bending of the upper yarn path.
[0074]
As shown in FIG. 8, the thread guide 128A protrudes from a slit 130 formed on the side of the operator of the sewing machine main body 80A, and is substantially crank-shaped supported on the side of the sewing machine main body 80A by a shaft 128C. The lever structure is configured such that the upper thread 14 is hooked inside the outer corner portion.
[0075]
The yarn guide driving device 128B is supported on a side surface of the sewing machine main body 80A by a swing shaft 129 so as to be swingable, and a substantially L-shaped drive lever 128D whose tip is swingably engaged with the yarn guide 128A. And a solenoid 128E that is swingably engaged with the drive lever 128D.
[0076]
As shown in FIG. Thread When the limit switch 112C of the origin detecting means 112 outputs the origin detection signal when the knot control device 81 is in the mode of driving the yarn hooking claw 110 to the standby position, the pulse motor 106E is rotated in the reverse direction. In addition, the cam follower 110C is reliably positioned at the bottom of the cam groove 108C by driving a predetermined number of pulses in a state where the amount of current is reduced (current down).
[0077]
Here, as described above, the pulse motor 106E is disposed at a position spaced apart from the needle 12 on the lower side near the base end of the arm portion 80B in the sewing machine main body 80A. Therefore, the pulse motor 106E, which is an actuator of the yarn knotting device 84 and the yarn hooking device 86, does not need to be installed in a narrow place near these devices, and the degree of freedom in design can be expanded.
[0078]
The yarn knot control device 81 idles the cylindrical cam 108 to the home position in the forward direction by the pulse motor 106E after one rotation of the sewing machine 80 and before the next yarn hooking, and then the pulse motor The configuration is such that 106E is reversed by a predetermined number of pulses in the current down state.
[0079]
As shown in FIG. 11, the yarn knot control device 81 is configured so that an operator can set conditions using a thread winding number setting switch 81A, a sewing start thread remaining length setting switch 81B, and a thread type setting switch 81C. Further, the pulse motor piece feed switch 81D allows the pulse motor 106E to be finely driven manually to adjust the mutual relationship between the thread clamp device 82, the yarn knot device 84, and the yarn hooking device 86. Further, the operation timing of the solenoid 128E in the thread guide driving device 128B can be adjusted by a needle thread return timing setting switch 81E.
[0080]
Yarns have different rigidity depending on the material and the count, and if the rigidity is large, the resistance during rotation in the yarn knotting device 84 increases, so the rotational speed of the device must be slowed down to increase the torque. Accordingly, a thread type setting switch 81C is provided to optimize the rotation speed of the pulse motor 106E depending on the thread type.
[0081]
Next, the operation of the sewing machine 80 will be described with reference to the flowcharts of FIGS.
[0082]
In step 101, the power is turned on. In step 102, it is determined whether the sewing machine has started rotating. YES If so, go to Step 108.
[0083]
Next, in step 108, the pulse motor 106E is rotated in the forward direction at the set speed CW. In step 109, it is determined whether or not the limit switch 112C of the origin detection means 112 has detected the origin. YES That is, when the origin is detected, in step 110, the pulse motor 106E is stopped, in step 111, the drive current of the pulse motor 106E is reduced in current, and in step 112, the pulse motor 106E is rotated in the reverse direction by a predetermined number of pulses. To drive.
[0084]
This predetermined (set) number of pulses corresponds to a distance slightly longer than the bottom of the cam groove 108C from the origin, but further from the state where the cam follower 110C is at the stroke end with respect to the bottom of the cam groove 108C. Even if the drive 106E is driven, the current motor is in a down state, so that the pulse motor 106E does not become unreasonable.
[0085]
In the next step 113, it is determined whether or not the set number of pulses has been reached. YES If so, the pulse motor 106E is stopped in step 114.
[0086]
Next, in steps 115 to 117, the thread knot control device 81 reads the number of thread windings, the sewing start thread remaining length, and the thread type setting values that are preset by the operator.
[0087]
Next, it is determined in step 118 whether or not a thread trimming operation has been performed, YES If so, the process proceeds to step 119, where it is determined whether or not the upper axis of the sewing machine is placed higher. YES If in step 120 The A negative pressure is applied to the ramping head 90. Further, in step 121, the thread holding is released, and in step 122, it is determined whether or not the thread trimming after the previous series of stitches is finished, YES If so, the process proceeds to step 122A, the solenoid 128E is turned on, and the thread guide 128A is driven to the upper thread feeding position in the upper part in the drawing, and the slack of the thread is formed between the thread tensioner 120 and the needle 12.
[0088]
Next, the timer is activated in step 124, and after a predetermined time, in step 125, the wiper 88 of the thread clamp device 82 is swung to the left in the figure by the rotating shaft 88A, further protrudes forward, and then swung to the right. The upper thread 14 is hooked between the needle 12 and the fabric 18 by the thread clamp hook 88B.
[0089]
These operation times are set by a timer in step 124, and when the set time has elapsed, the swing of the wiper 88 is stopped in step 125.
[0090]
Next, by a timer in step 126, the thread end of the upper thread 14 hooked on the thread gripping hook 88B of the wiper 88 is moved into the negative pressure path 90B by the negative pressure from the suction port 90A of the clamping head 90 after a predetermined time. After the suction time has elapsed, the ball 90C in the clamping head 90 is driven by the clamping cylinder 90D, and the yarn end is pinched between the suction port 90A and the ball 90C to be clamped.
[0091]
Next, after the timer set time in step 128 ends, the negative pressure applied to the clamping head 90 is turned off in step 129. In addition, after holding the end of the upper thread 14 in the clamping head 90, after the timer set time of step 130 is completed, step 131 (hereinafter shown in the figure). 13 The sewing machine rotation is prohibited in
[0092]
If the sewing machine is rotated while the end of the upper thread 14 is held by the clamping head 90, the upper thread 14 is pulled when the needle 12 descends and is pulled out of the clamping head 90. This is to prevent it.
[0093]
Next, in step 132, it is determined whether or not the number of windings set by the operator is one.
[0094]
If it is 1 time, it will progress to step 133, and if it is 2 times or more, it will progress to step 134. In step 134, it is determined whether or not the set thread winding number is two times. YES If so, the process proceeds to step 135, and if it is three or more times, the process proceeds to step 136.
[0095]
In step 136, it is determined whether or not the set number of yarn windings is three times. YES If so, the process proceeds to step 137, and if it is four times or more, the process proceeds to step 138. In the same manner, the number of windings is sequentially increased and determined.
[0096]
When the set number of turns is one, in step 133, the pulse motor 106E is driven in the forward direction at the set speed ACW.
[0097]
At this time, in the process of Step 109 to Step 114 described above, the yarn knot 92 is directed downward as in the sewing machine 80 of FIG. 1, and in this state, the upper thread is hooked by the wiper 88 and the needle is hooked. When the upper thread 14 is stretched between the head 12 and the clamping head 90, the upper thread 14 is hooked on the inner corner 103 of the yarn knot 90 extending from the rotation shaft 94 to the claw 102.
[0098]
In this state, when the pulse motor 106E is rotated in the forward direction in step 133, the cylindrical cam 108 is integrally rotated by the drive shaft 106, and the cam follower 110C of the yarn hooking claw 110 is camped along the cam groove 108C. It is driven toward the surface 108B and gets on the cam surface 108B. Accordingly, the thread hooking claw 110 is pushed out against the return spring 110A, and the upper thread 14 is pushed out between the needle 12 and the cam portion 102 at the tip thereof.
[0099]
In this state, according to the rotation of the pulse motor 106E, the thread knot 92 rotates, and the upper thread is wound around the inner corner 103 of the claw 102 to form a ring. At this time, the sewing machine of FIG. 80 As in, the clamp portion 98 of the yarn knot 92 is opened and closed by the ring-shaped cam 100, and when the rotation is made approximately one turn, the side of the formed ring close to the clamping head 90 is cut and cut into the slit 96A. Clamp the thread end.
[0100]
Whether or not this clamping has been completed is determined in step 139 by determining whether or not the number of pulses for driving the pulse motor 106E has reached the set number of pulses.
[0101]
When the yarn knot 90 rotates approximately once, the process proceeds to step 140, and the speed of the pulse motor 106E is reduced to a speed BCW that can be stopped at any time without causing a step-out.
[0102]
Next, in steps 141 to 146, in the same process as in steps 109 to 114, the cylindrical cam 108 is reversed, and the cam follower 110C of the yarn hooking claw 110 is driven into the cam groove 108C from the cam surface 108B, and the standby position. Let me.
[0103]
Next, in step 147, the prohibition of sewing machine rotation is canceled, the process proceeds to step 163, the set value of the needle thread retracting timing setting switch 81E is read, and in step 164, it is determined whether the sewing machine has started rotating. YES If so, the process proceeds to the next step 165.
[0104]
In step 165, it is determined whether or not the pullback timing L · SW is reached. NO If so, go to step 166. YES If so, go to Step 167.
[0105]
In step 166, it is determined whether the upper shaft of the sewing machine has passed the lower position, YES If so, it is determined in step 168 whether the sewing machine tacho generator has reached the set value A, YES If so, the process proceeds to step 167 described above.
[0106]
In step 167, the solenoid 122B of the needle thread feeding stop device 122 is turned on to suppress the thread tensioner 120 to stop feeding of the upper thread, and in step 168, the solenoid 126B of the thread take-up spring stopper 126 is turned on to remove the thread. The spring 124 is restrained, and the upper thread is fed out by bending the thread take-up spring 124. Therefore, when the loop is formed on the upper thread 14 by the thread knot 92 of the thread knotting device 84, the upper thread is not supplied from the thread tensioner 120 and the thread take-up spring 124.
[0107]
For this reason, since the needle thread length from the needle 12 to the knot is shortened and the upper thread pull-back amount described later is small, variation in the needle thread length is reduced. Therefore, the thread length at the start of the next sewing is stabilized.
[0108]
Also, if the upper thread is loose, even if the needle 12 is lowered at the beginning of sewing, the ring formed on the thread knot 92 cannot be pulled so as to come out of the thread knot 92, so that the knot cannot be made. By restricting the upper thread feeding from the thread tensioner 120 and the thread take-up spring 124 in advance, the knot can be reliably formed.
[0109]
Next, in step 169, the timer is activated, and after a predetermined time, in step 170, the solenoid 128E of the upper thread pull-back device 128 is activated, and the thread guide 128A is pushed down to lengthen the path of the upper thread. Pull back from.
[0110]
At this time, as described above, the thread tensioner 120 and the thread take-up spring 124 are constrained and the upper thread is not drawn out from them, so that the amount of increase in the thread path formed by the descending of the thread guide 128A is exclusively. It is supplemented by the bent thread between the needle 12 and the thread knot 92.
[0111]
Accordingly, if the upper thread pull-back amount is set appropriately in advance, the upper thread loop comes out of the thread knot 92 when the needle 12 is lowered, and a knot is surely formed.
[0112]
Further, after the time set by the timer in the next step 171 has elapsed, the control of the thread take-up spring stopper 126 is released.
[0113]
This is because when the sewing machine further rotates and the needle 12 descends, and the thread path of the balance becomes longer due to thread pulling, the amount of the upper thread becomes insufficient, and the thread end clamped at the tip of the thread knot 92 This is to prevent the separation.
[0114]
Therefore, the knot of the upper thread is maintained so as not to come off from the thread knot 92 by the lowering of the needle 12. If the hook end (not shown) is not clamped while the upper thread 14 is hooked on the lower side of the fabric 18, the knot will come out on the back side of the fabric 18. Has been released.
[0115]
However, since it is necessary to release the clamp of the yarn end by the yarn knot 92 after the hooking of the hook is finished, the timer is operated in step 173, and the eccentric cam is turned on in step 174.
[0116]
That is, the ring-shaped cam 100 is driven by the actuator 100B in the direction in which the clamp 98 is opened, and the upper thread 14 with the knot that is restrained by the thread knot 92 after the previous series of stitches is released.
[0117]
Accordingly, since the needle 12 is in the ascending process at this time, the knot is not drawn into the hole formed in the fabric 18 by the needle 12 and goes out to the lower side of the fabric 18.
[0118]
In step 176, it is checked whether the tacho generator has reached the set value B, whether the yarn has been released, YES If so, the process proceeds to step 178, where the drive of the ring cam 100 by the actuator 100B is turned off. Further, in step 179, the timer is operated, and after the set time, the upper thread feeding stop device 122 is turned off in step 180, the thread tensioner 120 is released, and the process returns to step 115 described above.
[0119]
Next, the process proceeds from step 132 to step 134, and the case where the number of set thread windings is two will be described.
[0120]
In this case, in step 135, the pulse motor 106E is rotated in the forward direction at high speed DCW. This is because the yarn knotting operation is too slow when the set number of yarn windings is the same as that when the number of yarn windings is one.
[0121]
As shown in FIG. 15, the initial position of the yarn knot 92 is at a position substantially orthogonal to the line of the upper thread 14 stretched between the needle 12 and the clamping head 90. In FIG. Shown in °. At this time, the ring-shaped cam 100 is driven in advance by an actuator 100B at a position where its center is eccentric to the needle 12 side with respect to the rotary shaft 94 of the yarn knot 92 (plus eccentricity).
[0122]
Therefore, in this state, when the claw portion 102 is driven to rotate in the clockwise direction in the drawing around the rotation shaft 94, the clamp portion 98 is pushed in the closing direction by the ring-shaped cam 100, and therefore, as shown in FIG. Thus, the nail | claw part 102 does not open slightly.
[0123]
When the ring-shaped cam 100 is in an eccentric state, the clamp portion 98 is slightly opened, and the upper thread 14 may enter here.
[0124]
The claw portion 102 is slightly opened at the initial position indicated by 0 ° in the drawing and the position rotated by 180 ° since the ring cam 100 is the same as the non-eccentric state. However, at the initial position of 0 ° and the position rotated 180 °, the tip of the claw portion 102 is located away from the line of the upper thread 14, so that the upper thread 14 does not enter the claw portion 102.
[0125]
Whether or not the number of drive pulses of the pulse motor 106E has reached the set value A in step 148 whether or not the ring-shaped cam 100 has been decentered toward the needle 12 and has rotated about half a half from the initial position of 0 ° shown in the figure. Judged by no. YES If this is the case, the process proceeds to step 149, where the actuator 100B is turned off and returned to its original position by a return spring (not shown), so that the ring cam 100 is clamped in the drawing on the opposite side from the center of the rotary shaft 94 in the figure. It is eccentric toward the head 90 side. In this state, when the yarn knot 92 further rotates about half a half, the clamp portion 98 is further driven to close by the ring-shaped cam 100 in the same manner as described above, so that the upper portion between the nail portion main body 96 and the clamp portion 98 is raised. There is no thread entering.
[0126]
Whether or not the yarn knot 92 has rotated 180 ° to 360 ° from the initial position is determined based on whether or not the number of drive pulses of the pulse motor 106E has reached the set value B in step 105.
[0127]
Judgment result is YES If so, in step 151, the ring-shaped cam 100 is released from being decentered to the minus side by turning on the actuator 100B. That is, the ring-shaped cam 100 is returned to a state eccentric to the plus side (the needle 12 side).
[0128]
From this state, the thread knot 92 is further rotated about once. As described above, the ring cam 100 is eccentric to the plus side. The clamp portion 98 is closed even when it is caught, and the tip of the claw portion 102 is not opened even slightly, so that the upper thread 14 does not enter the tip.
[0129]
When further rotated about a half turn from there, the clamp portion 98 of the thread knot 92 is opened by the ring-shaped cam 100 eccentric to the plus side, and the upper thread 14 enters there, and in the same manner as described above, clamping, cutting, A process of clamping in the slit 96A is performed.
[0130]
The cut yarn end side is sucked from the suction port 90A toward the negative pressure path 90B by the ball 90C being pulled back by the clamping cylinder 90D, and is collected by the collecting means (not shown).
[0131]
Whether or not the second rotation of the yarn knot 92 has been completed is determined in step 152 based on whether or not the drive pulse of the pulse motor 106E has reached the set number of pulses. YES If so, the process proceeds to step 140 in the case where the number of windings is 1, and the same process as described above is obtained.
[0132]
When it is determined in step 136 that the number of set thread windings is 3, as shown in steps 137 to 161, the same process as in steps 148 to 151 in the case where the number of set thread windings is 2 is repeated twice. From step 161, it is determined in step 162 whether or not the final set number of pulses for one rotation has been reached, and then the process returns to step 140 described above.
[0133]
When the set number of thread windings is 4 or more, the above-described steps 148 to 151 are repeated by the set number of thread windings minus one, and then the process returns to step 140 through the same process as step 162.
[0134]
In the sewing machine 80, the thread hooking claws are all driven by a cylindrical cam. However, the present invention is not limited to this. For example, the thread hooking claws are directly driven by an actuator such as a solenoid. It may be. In this case, a cylindrical cam, a cam follower driven by the cylindrical cam, and a pulse motor reverse rotation control including an origin detecting means are not required.
[0135]
The upper thread feeding stop device 122 is configured to suppress the feeding of the thread from the thread tensioner 120 by pressing the thread tension spring 120A of the thread tensioner 120 with the pressing lever 122A. The invention is not limited to this. In short, it may be anything that can press the upper thread directly or indirectly by the pressing member and stop its feeding, for example, FIG. 17 As shown in FIG. 4, the upper thread 14 wound around the thread tension plate 120B of the thread tensioner 120 is directly pressed by the pressing shoe 132A at the tip of the lever 132 to feed the upper thread. Stop You may do it. Figure 17 Reference numeral 134 denotes a solenoid that swings the lever 132 via a spring 136 and elastically presses the pressing shoe 132A against the upper thread 14.
[0136]
Also, figure 18 As shown in FIG. 4, the upper thread 14 is sandwiched from the disk 138A sucked by the solenoid 138 in the middle of the thread path between the thread tensioner 120 and the needle 12, and the upper thread feeding is stopped. Good.
[0137]
In addition, the figure 19 As shown in FIG. 5, the set pressure of the thread tension spring 120A may be increased by attracting the central shaft 120C of the thread tensioner 120 by the solenoid 120D. In this case, the tension at the time of pulling the upper thread can be controlled in a plurality of stages by setting the tension force by the solenoid 120D in a plurality of stages.
[0138]
Further, the thread take-up spring stopper 126 is adapted to stop the operation of the thread take-up spring 124 by being hooked by the stopper lever 126A. However, the present invention is not limited to this, for example, as shown in FIG. As described above, the stopper 140A may be driven by the solenoid 140B via the lever 140C and brought into contact with the thread take-up spring 124, thereby restricting the displacement of the thread take-up spring 124 in the thread feeding direction.
[0139]
Also, figure 21 As shown in FIG. 5, the upper thread 14 may be pressed by the pressing shoe 142A at a position downstream of the thread take-up spring 124. Other parts are illustrations 17 The description is omitted by using the reference numeral.
[0140]
The upper thread pull-back device 128 adjusts the path length of the upper thread by driving the thread guide 128A moving in the vertical direction up and down by the thread guide driving device 128B. For example, as shown in FIG. 21, the yarn path may be adjusted by a swing lever-like yarn guide 142A.
[0141]
【The invention's effect】
Since the present invention is configured as described above, the knot of the upper thread is formed in the vicinity of the cut end, and the distance between the knot and the needle can be set accurately. Etc. have an excellent effect that the appearance at the start of sewing is not deteriorated by the thread tightly tightened or the thread protruding to the contrary.
[Brief description of the drawings]
FIG. 1 is a front view showing a main part of a sewing machine according to an example of an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the same.
FIG. 3 is a cross-sectional view showing a state of cutting and holding an upper thread by a claw portion of a yarn knot
FIG. 4 is a perspective view showing a mounting state of a pulse motor which is a drive source of the yarn knotting device in the sewing machine.
FIG. 5 is a schematic front view showing a relationship between a thread knot, a needle, and a thread hook claw and a thread in the sewing machine.
FIG. 6 is an enlarged cross-sectional view showing an upper thread feeding stop device in the sewing machine.
FIG. 7 is a schematic front view showing a thread take-up spring stopper in the sewing machine.
FIG. 8 is a schematic front view showing an upper thread pulling device in the sewing machine.
FIG. 9 is a sectional view of the same.
FIG. 10 is a block diagram showing a control system of the sewing machine.
FIG. 11 is a front view showing an arrangement state of switches of the sewing machine.
FIG. 12 is a flowchart showing the operation of the sewing machine.
FIG. 13 is a flowchart showing the operation of the sewing machine.
FIG. 14 is a flowchart showing the operation of the sewing machine.
FIG. 15 is a diagram showing the action and relationship of the yarn knot and the ring cam of the yarn knot device in the sewing machine;
FIG. 16 is a timing chart showing the operation of the sewing machine
FIG. 17 is a schematic front view showing an example of another embodiment of an upper thread feeding stop device;
FIG. 18 is a side view showing an example of still another embodiment of the upper thread feeding stop device.
FIG. 19 is a sectional view showing still another example of the upper thread feeding stop device according to another embodiment.
FIG. 20 is a front view showing an example of another embodiment of the thread take-up spring stopper.
FIG. 21 is a front view showing still another example of still another embodiment of the thread take-up spring stopper.
22 is a schematic front view showing an example of another embodiment of the upper thread pull-back device. FIG.
[Explanation of symbols]
12 ... Needle
14 ... Upper thread
18 ... Fabric
80 ... Sewing machine
80A ... sewing machine
80B ... Arm
81. Yarn knot control device
81A ... Number of spool winding setting switch
81B ... Sewing start thread remaining length setting switch
81C ... Thread type setting switch
81D ... Pulse motor top switch
81E ... Needle thread return timing setting switch
82 ... Thread clamp device
84 ... Yarn knotting device
85 ... Control device
86 ... Yarn hanging device
86B ... Reverse rotation control device
88 ... Wiper
88A ... Rotating shaft
88B ... Thread clamp hook
90 ... Clamping head
92 ... thread knot
94: Rotating shaft
96 ... nail body
96A ... Slit
98 ... Clamp part
100 ... Ring-shaped cam
100B ... Actuator
102 ... nail part
103 ... Inner corner
106: Drive shaft
106A ... Mounting hole
106B ... Fixing screw
106E ... Pulse motor
108 ... Cylindrical cam
108B ... cam surface
108C ... Cam groove
110 ... thread hook nail
110C ... Cam follower
112: Origin detecting means
120 ... thread tensioner
122 ... Upper thread feeding stop device
124 ... thread take-up spring
126 ... Thread take-up spring stopper
128 ... Upper thread pulling device
128A, 142A ... thread guide
128B ... Yarn guide drive device

Claims (6)

In a sewing machine, an upper thread to be hung on a needle and a lower thread to be entangled with the upper thread are sewn into a sheet-like material, and the upper thread is supplied to the needle through a thread tensioner having a thread take-up spring. ,
After a series of stitches is finished, a thread clamp that holds the upper thread between the needle and the sheet-like material and pulls the upper thread obliquely upward from the needle hole of the needle by pulling it to the side of the needle The device and the upper thread stretched by the thread gripping device are arranged in contact with each other, and the upper thread is entangled to form a ring, and the thread gripping device side of the ring is cut and cut. A thread knot device for grasping an end of the upper thread on the needle side and forming a knot through the ring; and a pressing member for pressing at least one of the thread tensioner and the upper thread upstream of the thread take-up spring, A sewing machine comprising: an upper thread feeding stop device that is operated when an upper thread is entangled by a yarn knotting device to form a ring, and stops the upper thread feeding. In a sewing machine, an upper thread to be hung on a needle and a lower thread to be entangled with the upper thread are sewn into a sheet-like material, and the upper thread is supplied to the needle through a thread tensioner having a thread take-up spring. ,
After a series of stitches is finished, a thread clamp that holds the upper thread between the needle and the sheet-like material and pulls the upper thread obliquely upward from the needle hole of the needle by pulling it to the side of the needle The device and the upper thread stretched by the thread gripping device are arranged in contact with each other, and the upper thread is entangled to form a ring, and the thread gripping device side of the ring is cut and cut. A thread knot device for grasping an end of the upper thread on the needle side and forming a knot through the ring; and a pressing member for pressing at least one of the thread tensioner and the upper thread upstream of the thread take-up spring, An upper thread feeding stop device that is operated when making a ring by entwining the upper thread with the thread knotting device at the time of lowering the needle at the start of sewing, and stops the feeding of the upper thread. When the upper thread is pulled by the needle, the loop of the upper thread is Et exit tightened, sewing, characterized in that knot is completed. An upper thread to be hung on the needle and a lower thread to be entangled with the upper thread by a hook are sewn into the sheet-like material, and the upper thread is supplied to the needle through a thread tensioner having a thread take-up spring. In the sewing machine
After completing a series of stitches, a thread clamp that holds the upper thread between the needle and the sheet-like material and pulls the upper thread obliquely upward from the needle hole of the needle by pulling it to the side of the needle The device and the upper thread stretched by the thread gripping device are arranged in contact with each other, and the upper thread is entangled to form a ring, and the thread gripping device side of the ring is cut and cut. A thread knot device for grasping an end of the upper thread on the needle side and forming a knot through the ring, and a thread take-up spring which can be freely hooked to the thread take-up spring and hooked on the thread take-up spring when the needle is lowered at the start of sewing. A thread take-up spring stopper that restricts displacement in the upper thread feeding direction and opens the thread take-up spring after the upper thread protruding below the sheet-like material by the lowering of the needle at the start of sewing is started by the hook. And at the beginning of sewing, the needle thread is By being tensile, wheels of the upper thread, tightened exits from the yarn knot device, a sewing machine, characterized in that knot is completed. In a sewing machine for sewing an upper thread that is supplied via a thread tensioner and is hung on a needle and a lower thread that is entangled with the upper thread into a sheet-like material,
After a series of stitches is finished, a thread clamp that holds the upper thread between the needle and the sheet-like material and pulls the upper thread obliquely upward from the needle hole of the needle by pulling it to the side of the needle The device and the upper thread stretched by the thread gripping device are arranged in contact with each other, and the upper thread is entangled to form a ring, and the thread gripping device side of the ring is cut and cut. In the middle of the path of the upper thread between the thread knotting device and the thread tensioner, the thread knot device for grasping the needle side end of the upper thread and forming a knot through the ring, the position is freely adjustable, An upper thread pull-back device including a thread guide that changes the degree of bending of the path is provided.   5. The upper thread pull-back device according to claim 4, wherein the upper thread pull-back device is configured to reduce the bending of the path immediately before the upper thread is pulled by the thread gripping device after a series of stitches is finished, and A sewing machine characterized in that, at the end, the yarn guide is driven in the direction of increasing the bending of the path. In a sewing machine for sewing an upper thread to be hung on a needle and a lower thread to be entangled with the upper thread into a sheet-like material,
After completing a series of stitches, a thread clamp that holds the upper thread between the needle and the sheet-like material and pulls the upper thread obliquely upward from the needle hole of the needle by pulling it to the side of the needle The device and the upper thread stretched by the thread gripping device are arranged in contact with each other, and the upper thread is entangled to form a ring, and the thread gripping device side of the ring is cut and cut. A yarn knot device for grasping an end of the upper thread on the needle side and forming a knot through the ring, and a yarn hooking device are provided. A rotation shaft that is rotatable about a rotation axis substantially perpendicular to the rotation axis, and a thread knot that includes a claw portion that is bent and extended approximately 90 ° continuously from the tip of the rotation shaft. By rotating the rotary shaft over the inner corner from the rotary shaft to the claw portion Forming a loop of an upper thread that winds around the rotating shaft, and the thread hooking device is disposed at a position that can contact the stretched upper thread between the needle and the thread knot, and the upper thread A thread hooking claw that is parallel to the rotational axis of the thread knot and is displaced in the direction of its tip, and the upper thread is bent and hooked in the direction of the tip of the nail at the inner corner of the thread knot; An actuator for driving the yarn hooking claw, and the actuator has a displacement amount in the tip direction of the yarn hooking claw, and when the rotation angle of the yarn knot makes the upper thread path length the longest. The sewing machine is characterized in that the thread hooking claw is driven to a position where the upper thread is tensioned when the upper thread is cut by the thread knotting device.

Images