KR20020067971A - Holding upper thread device for sewing machine - Google Patents

Abstract

PURPOSE: To provide a needle thread clamping device capable of surely holding the tip end of a needle thread by increasing the length of the needle thread left after cutting. CONSTITUTION: The needle thread clamping device comprises tension units 50 and 52 arranged on a thread path leading from a thread supply source to a needle 32 for applying predetermined tension to a needle thread 33, a thread handler 54 arranged on the thread path for drawing up or down the thread through vertical movement, a wiper 60 having a tip end portion 60a capable of intersecting the vertical locus 35 of a needlebar to catch the end of the needle thread thereby after cutting and a holding mechanism 40 for holding the tip end of the needle thread caught by the wiper. The needle thread clamping device further comprises a control means 70 which raises the thread handler before cutting the needle thread to maintain the tension thereof and lowers the same after the completion of cutting the needle thread to release the tension thereof.

Description

Upper thread clamp device of sewing machine {HOLDING UPPER THREAD DEVICE FOR SEWING MACHINE}

The present invention relates to an upper thread clamp device of a sewing machine having a wiper for discarding the thread between the needle and the sewing cloth after cutting and pulling the end of the thread over the sewing cloth.

In the sewing machine provided with the wiper, when a thread cutting signal is generated when sewing is finished, the upper and lower threads are cut below the sewing cloth, and then the upper thread connected to the needle is pulled up to the sewing cloth according to the operation of the wiper. When starting the next sewing in this state, since the tip of the upper thread is located close to the sewing machine needle, the tip of the upper thread is sewn several times to form a so-called thread knot, which is not good in appearance. For this reason, various designs regarding the installation of the upper thread clamp device which hold | maintain the upper thread tip to start sewing in the state which hold | maintained the tip of this upper thread are proposed.

An example of this upper thread clamp device is demonstrated based on FIGS. 15-17. In FIG. 15, the upper thread clamp device 10 is arranged near the sewing machine needle 2 attached to the lower part of the sewing machine 1. The upper thread clamp device 10 is attached to the base 1a of the sewing machine through the holding table 11, and a pipe 12 extending horizontally with respect to the base is provided. One end of the pipe 12 communicates with the negative pressure supply source 4, and the other end has a clamp portion 13 attached thereto.

As shown in FIG. 16, the clamp part is enlarged, and an inner space 13a is formed, and two openings 13b and 13c are formed. The opening 13b is connected to the negative pressure supply source 4 through the pipe 12, and the opening 13c communicates with the suction nozzle 14. Moreover, the cylinder 15 which has the cylinder rod 15a is provided above the clamp part 13, and the ball 16 is accommodated in the internal space 13a of the clamp part 13. As shown in FIG. The ball 16 is made to float in the interior space (13a) when a negative pressure occurs in the interior space (13a), the circle 16 can land in the interior space in accordance with the spherical surface of the ball 16 An abstract landing surface 13d is formed. The clamp portion 13 is attached obliquely to the horizontally extending pipe 12, and the suction port 14a of the suction nozzle 14 attached to the tip thereof is disposed near the lower position of the sewing machine needle 2.

Next, the operation of the sewing machine upper thread clamp device 10 configured as described above will be described with reference to FIG.

First, as shown in Fig. 18A, after the end of sewing, the thread 3 of the needle is cut and pulled up by the wiper (not shown) to the upper surface of the sewing cloth, and the tip 3a of the thread is a sewing machine needle. It is located in the vicinity of (2). In this state, the negative pressure supply source 4 is operated to generate negative pressure into the nozzle 14 through the pipe 12, thereby sucking the tip 3a of the needle thread 3 through the suction port 14a of the nozzle. . At this time, the cylinder 15 is not yet operated, and the ball 16 floats inside the inner space 13a of the clamp portion. When the needle thread is sufficiently sucked by the clamp portion 13, the tip 3a of the thread is sucked into the pipe 12 through the space between the ball 16 and the landing surface 13d.

In this state, as shown in Fig. 18B, the cylinder 15 is operated, and the cylinder rod 15a is pushed onto the ball 16 to press the ball 16 in the direction of the landing surface 13d. do. The ball 16 is squeezed onto the landing surface 13d while sliding on the landing surface 13d, whereby the thread 3 of the needle is held between the ball 16 and the landing surface 13d. This state is as shown in Fig. 18C.

In this manner, sewing is started when the yarn is held in a secure state. The yarn between the point B which is the first contact point and the point A of the nozzle suction port 14a is gradually tensioned by the transfer operation (see Fig. 18 (D)).

As shown in Fig. 19, the knife 20 is fixed to the suction port 14a of the nozzle. When the point B moves to the point B 'as shown in Fig. 17 according to the sewing transfer operation, the thread of the needle becomes the nozzle suction port 14a. By moving relative to, the upper edge of the blade of the knife 20 is gradually pulled, and the thread 3 of the needle is cut. This cut thread end 3a can be discharged to the outside through the negative pressure source 4 at the next sewing.

However, in the upper thread clamp device 10 according to the conventional example, if the remaining length of the upper thread extending from the needle hole of the sewing machine needle 2 after cutting the thread is short, the upper thread cannot be sucked, which may cause a clamp failure. . In particular, in the case of a zigzag sewing machine, since the needle moves left and right, the length of the upper thread after cutting the thread varies depending on which of the left and right positions of the final needle increases, so that a possibility of clamp failure is increased.

In addition, since the distance between the suction port of the clamp device and the needle hole must be shorter than the rest of the upper thread, when the remaining length of the upper thread is short, the suction port of the clamp device can only be disposed near the needle hole. The area becomes narrower.

Accordingly, it is an object of the present invention to provide an upper thread clamp device capable of lengthening the remaining length of the upper thread after cutting so as to securely hold the upper thread end.

Another object of the present invention is to provide an upper thread clamp device which can extend the area where the operator operates the sewing cloth by placing the suction port of the clamp device at a position away from the needle hole by lengthening the remaining length of the upper thread after cutting. .

BRIEF DESCRIPTION OF THE DRAWINGS The principal part external appearance perspective view of embodiment of the upper thread clamp apparatus of the sewing machine which concerns on this invention.

2 is a perspective view showing a state in which the wiper of the apparatus according to the present embodiment is in the standby position.

3 is a perspective view showing a state where the distal end of the wiper of the apparatus according to the present embodiment is moved away from the suction port of the upper thread clamp device and moved to a position beyond the position of the needle.

Fig. 4 is a perspective view showing a state in which the wiper distal end of the device according to the present embodiment intersects the shank trajectory of the needle bar to enclose the upper thread and further lift upwards.

5 is a perspective view illustrating a state in which the tip portion of the wiper is further raised in the state of FIG. 4.

6 is a perspective view showing a state in which the tip portion of the wiper has moved to a position facing the suction port through the state of FIG. 5.

7 is a perspective view showing a state where the upper thread is held by the upper thread clamp device of the present embodiment.

8 is a block diagram illustrating a control system of the apparatus according to the present embodiment.

9 is an operation timing chart of each device controlled by the control device of the device according to the present embodiment.

10 is a flowchart for explaining an operation performed by the controller of the apparatus according to the present embodiment.

11 is a flowchart for explaining an operation performed by the controller of the apparatus according to the present embodiment.

12 is a flowchart for explaining another example of the operation of each device controlled by the control device of the device according to the present embodiment.

13 is a perspective view of another example of a suction port of the upper thread clamp device according to the present invention.

14 is a perspective view of still another example of the suction port of the upper thread clamp device according to the present invention.

Fig. 15 is a side view showing the structure of a device according to the prior art.

16 is an enlarged cross-sectional view illustrating an internal state of the clamp unit of FIG. 15.

17 is a top view of a device according to the prior art.

18 is a cross-sectional view illustrating the operation of the apparatus according to the prior art according to (A) to (D).

Fig. 19 is an explanatory view showing the attachment state of the cutter of the apparatus according to the prior art.

Description of the main parts of the drawing

32: needle 33: upper thread

34: needle bar 35: shanghai east trajectory of the needle bar

40: upper thread holding device (holding means) 44: suction port

44a: protrusion 50: pretension (1st thread adjusting means)

52: rotary tension (second thread control means) 54: thread winding device

54b: Thread winding wire (thread winding member) 60: Wiper

60a: thread forming part (tip) 70: control device

In order to achieve the above object, according to the present invention, the thread adjusting means is disposed on the thread path from the thread source to the sewing needle and imparts a predetermined tension to the upper thread, and has a tip portion that can intersect the shank trajectory of the needle. A wiper capable of enveloping the upper thread end connected to the needle by its distal end, and holding means for holding the upper thread end encapsulated by the wiper, and after the upper thread is cut below the sewing material, the upper thread end enveloped by the wiper An upper thread clamp device of a sewing machine held by a holding means, comprising: a thread winding member disposed on a thread path between the thread adjusting means and a needle, the thread winding member tensioning or releasing the upper thread by reciprocating, and the thread winding member before a thread cutting operation; While maintaining the tension state of the upper thread, and returning the thread winding member after the end of the thread cutting operation, And a control means for controlling so as to reduce the jangsangtae.

Preferably, the control means controls the wiper to operate after a predetermined time after the seal winding member is returned.

It is preferable that the wiper is capable of reciprocating movement and returns by enclosing the upper thread during the return movement, and the retaining means is disposed at the front side suction port so as to face the thread forming portion of the returned wiper.

The control means may reciprocate the thread winding member again after the wiper is operated.

Embodiment of the upper thread clamp apparatus of the sewing machine which concerns on this invention is described according to drawing. First, a schematic configuration will be described with reference to FIG. 1. The present invention is preferably a zigzag sewing machine in which the needle moves to the left and right, but may be applied to a conventional sewing machine in which the needle does not move to the left and right.

The lower part of the jaw of the sewing machine head 30 is provided with a presser foot 31 and a needle bar 34 capable of moving the needle to the bed surface, and an upper thread 33 at the lower end of the needle bar 34. The passing needle 32 is fixed. A suction port 44 provided at the tip of the pipe 42 of the upper thread holding device (holding means) 40 is disposed near the right side of the needle 32. A negative pressure supply source 46 (FIG. 8) is connected to the proximal end side of the pipe 42.

The operation principle of the upper thread holding device 40 is the same as the upper thread clamp device 10 according to the prior art.

On the upper thread path from the upper thread source, not shown, to the needle 32, a pretension (first thread adjusting means; 50) and a rotary tension (second thread adjusting means; 52) are disposed, each of which is a thread of the upper thread. The thread is given a predetermined tension. The thread winding device 54 disposed on the sewing machine head portion 30 in proximity to the pretension 50 and the rotary tension 52 is a wire attachment table 54a supported to be rotatable to the sewing machine head portion 30. And a thread winding wire 54b (thread winding member) whose base is fixed to the wire attaching table 54a. The front end of the thread winding wire 54b may be disposed on the upper thread path between the rotary tension 52 and the needle to be engaged with the upper thread, and the thread winding wire 54b may be rotated by the wire attachment rod 54a. The tip of the pan moves up and down. As a result, when the tip of the thread winding wire 54b is raised, the extra upper thread 33 between the rotary tension 52 and the needle 32 is pulled up to become a tension state, and when the lower end is lowered, the tension state of the upper thread 33 is increased. Released (released).

The wire-shaped wiper 60 which bends the tip (bottom) to form the thread capping part (tip part 60a) has a standby position (FIG. 2) in which the thread capping part 60a faces the suction port 44, and a seal. The threader 60a intersects with the shankdong trajectory 35 of the needle 32 and swings between the moving positions (FIG. 3) beyond the shank trajectory 35 of the needle 32. In order to be able to rotate about the upper end, it is arrange | positioned.

Moreover, the projection part 44a is provided in the outer peripheral part located upward from the center of the suction port 44 of the said pipe 42 facing the outer side of the movement trace of the seal | sticker contact part 60a of a wiper.

Next, the operation of the wiper 60 will be described with reference to FIGS. 2 to 7. In addition, just before the wiper 60 starts moving, the upper thread 33 is cut | disconnected by the thread cutting device not shown.

When the wiper 60 returns from the moving position (FIG. 3), the needle 32 and the upper thread 33 connected to the sewing cloth are enveloped in the thread forming unit 60a (FIG. 4), and then the thread forming unit 60a As shown in FIG. 5, the upper thread 33 continues to approach the suction port 44 while pulling up the upper thread 33, and then moves to the return position. The moving direction A (FIG. 5) of the thread contact part 60a just before a return position is comprised so that it may become substantially the same direction as the suction direction B (FIG. 6) by the upper thread holding apparatus 40. As shown in FIG. In the return position, as shown in Fig. 6, the upper thread 33 touches the protrusion 44a of the suction port 44, and the unnecessary movement of the upper thread 33 is restricted. Thereafter, the upper thread holding operation is performed by the upper thread holding device 40. In addition, the principle of the thread holding operation according to the upper thread holding device 40 is similar to the upper thread clamping device 10 of the prior art, and the suction of the air under negative pressure and the clamping by the ball are performed. It is made using the same parts as the ball 16. As a result, the upper thread 33 is held by the upper thread holding device 40 as shown in FIG.

As can be seen from FIG. 7, in order to hold the upper thread 33 by the upper thread holding device 40, the remaining lengths of the upper thread 33 from the needle hole 32a to the end of the thread are defined by the suction port 44 and the needle ( It is necessary to make it longer than the distance L between the needle holes 32a of the 32.

Next, the control system of the present invention will be described with reference to the control block diagram of FIG. 8. The control device 70 stores a program for controlling a sewing machine and a ROM 71 storing data necessary for sewing, a CPU 72 responsible for various calculations and processing, data calculated by the CPU 72, and the like. RAM 73 is provided. The start switch 76 and the pedal switch 77 are connected to the CPU 72 via the input / output interface 74.

The sewing machine motor 80 connected to the sewing machine main shaft (not shown) is connected to the CPU 72 via the motor driver 82 and the input / output interface 74. On the rotary shaft of the sewing machine motor 80, an angle detector 84 connected to the CPU 72 via the input / output interface 74 is provided, and the rotation angle (rotational phase) is detected. In connection with this embodiment, the angle detector 84 is used to detect the upper and lower parts of the needle bar 34 and the needle 32.

The negative pressure supply source 46 of the upper thread holding device 40 is connected to the CPU 72 via the negative pressure source operating means 86 and the input / output interface 74. In addition, the clamp cylinder 88 (corresponding to the conventional cylinder 15 of the conventional example) that performs the thread holding operation by the upper thread holding device 40 is connected to the CPU via the clamp cylinder driving solenoid valve 100 and the input / output interface 74. It is connected to 72.

Moreover, the wiper which rotates the thread cutting cylinder 90 which operates a thread cutting device (not shown), the thread winding cylinder 92 which rotates the wire attachment stand 54a of the thread winding device 54, and the wiper 60 The cylinder 94 and the presser foot cylinder 96 for moving the presser foot 31 up and down are connected to the CPU 72 through the respective cylinder drive solenoid valves 102 to 108 and the input / output interface 74.

Next, the operation timing chart of each apparatus controlled by the control apparatus 70 is demonstrated based on FIG. In the figure, "high signal" and "low signal" are signals detected and changed by the angle detector 84, and are turned off when the upper and lower portions of the needle bar 34 are detected, respectively. The "thread cutting signal" is an operation signal of the yarn cutting cylinder 90, and is turned on during operation. The thread is actually cut at the end of the operation of the thread cutting cylinder 90, i.e., just before the illustrated thread cutting signal changes from on to off.

The "real winding signal" is turned on at the time of operation as an operation signal of the real winding cylinder 92. When it is turned on, the front end of the thread winding wire 54b is raised to give tension to the upper thread, and the off end is lowered to ease the tension of the upper thread. The "wiper signal" is an operation signal of the wiper cylinder 94, which is turned off during operation to start the movement of the wiper 60. The "presser foot rising signal" is an operation signal of the presser foot cylinder 96, and is turned on during operation to raise the presser foot 31. The "suction signal" is a signal for operating the negative pressure source 46 and is turned on at the time of operation. The " hold signal " is turned on at the time of operation as an operation signal of the clamp cylinder 88.

First, the lower part is detected by the angle detector 84, and the thread cutting cylinder 90 and the thread winding cylinder 92 are turned on by the thread cutting cylinder driving solenoid valve 102 and the thread winding cylinder driving solenoid valve 104. In addition, the negative pressure source 46 is operated by the negative pressure source operating means 86, and the clamp cylinder 88 is turned off by the clamp cylinder driving solenoid valve 100.

Subsequently, after a predetermined time (Ems) has elapsed from the time when the difference of the needle bar 34 is detected by the angle detector 84, the thread is cut by the thread cutting cylinder driving solenoid valve 102 and the thread winding cylinder driving solenoid valve 104. The cutting cylinder 90 and the thread winding cylinder 92 are turned off to terminate thread cutting, and the tip of the thread winding wire 54b is lowered. When a predetermined time Fms has elapsed after the end of the thread cutting, the wiper cylinder 94 is turned on by the wiper cylinder drive solenoid valve 106. The wiper cylinder 94 is kept off for a predetermined time (Gms) and then turned off.

Generally, the wiper 60 is operated at the same time as the end of the thread cutting. In the present embodiment, the wiper 60 is operated at a time point when a predetermined time Fms has elapsed after the end of the thread cutting. In general, the thread winding signal is turned off after a certain time has elapsed after the end of the thread cutting. In this embodiment, the off timing of the thread winding signal is synchronized with the thread cutting end timing. Activate the wiper 60 at intervals.

The remaining length of the upper thread can be lengthened according to the operation timing of the thread cutting, the thread winding wire 54b and the wiper 60.

That is, before the thread cutting operation, the thread winding wire 54b of the thread winding device 54 is raised to maintain the tension state of the upper thread 33, and the thread winding wire 54b is lowered at the end of the thread cutting and the upper thread ( After releasing the tension of 33, the wiper 60 operates to enclose the upper thread 33, so that the remaining length L of the upper thread 33 becomes long.

Therefore, since the remaining length of the upper thread can be lengthened by the thread winding wire 54b, compared with the conventional shorter length of the upper thread 33, the suction port 44 of the holding device 40 is positioned far from the needle hole ( In this embodiment, the wiper 60 can be disposed near the return position of the wiper 60, and the area where the operator operates the sewing cloth is widened. Furthermore, by setting the return position of the wiper 60 upwards, for example, to the vicinity of the same plane as the lower end of the jaw portion of the sewing machine head portion 30, the holding device 40 is above the jaw portion of the sewing machine head portion 30. Being able to be located at can widen the right area of the needle (32).

After the wiper cylinder 94 is turned off, a predetermined time (Hms) has elapsed, and then the presser foot cylinder 96 is turned on by the presser foot cylinder drive solenoid valve 108.

Furthermore, after a predetermined time (Jms) has elapsed at the time when the difference of the needles is detected, the clamp cylinder 88 is turned on by the clamp cylinder driving solenoid valve 100. Then, after a predetermined time Ims has elapsed from the time when the difference is detected, the operation of the negative pressure supply source 46 by the negative pressure source operating means 86 is stopped.

Next, operation | movement of this embodiment performed by the control apparatus 70 based on the flowchart of FIG. 10, FIG. 11 is demonstrated. In the drawings, S1, S2,... Indicates the number of the processing procedure (step). First, in S1, it is determined whether there is a sewing start request according to the operator's pedal operation or the like. That is, it is judged by the control apparatus 70 whether the start switch 76 of FIG. 8 was pressed. If the sewing start request is made, the process proceeds to S2 to turn off the clamp cylinder 88 and release the holding state of the upper thread end by the upper thread holding device 40. Subsequently, the sewing machine motor 80 is rotated in S3 to execute a sewing process.

Next, in S4, it is determined whether the operator requests the actual cutting by stepping on the pedal switch 77. If there is no request, the process returns to S3 to continue the sewing process. If there is a request, the process proceeds to S5, and it is determined whether the lower part is detected by the angle detector 84.

In S6, the thread cutting device and the thread winding device 54 are driven, and suction of the upper thread end is started. Subsequently, the procedure proceeds to S7 to determine whether the needle bar 34 has reached the upper level. After reaching the upper level, the process proceeds to S8 to stop the rotation of the sewing machine motor 80 and proceeds to S9.

In S9, it is determined whether a predetermined time (Ems) has elapsed since the needle bar 34 reaches the upper level, and at this point, the process proceeds to S10 of FIG. Proceed.

In S11, it is determined whether or not the predetermined time Fms has elapsed after the driving stop operation of S10, and when the elapsed time has elapsed, the process proceeds to S12 to drive the wiper 60 for a predetermined time Gms. 60, the upper end of the upper thread is enveloped in the thread encapsulation part 60a and moves to a position opposite to the suction port 44 of the upper thread retaining device 40, and then proceeds to S13.

In S13, it is determined whether the predetermined time (Jms) has elapsed after the needle bar 34 reaches the upper level, and when the elapsed time passes, the process proceeds to S14 to drive the clamp cylinder 88 by the upper thread holding device 40. After maintaining the upper thread end, proceed to S15. In S15, it is determined whether a predetermined time (Ims) has elapsed after the needle bar 34 reaches the upper level, and the flow proceeds to S16 at the time when the needle bar 34 reaches the upper level, and stops the operation of the negative pressure source 46 and stops suction of the upper thread end. do.

Next, another example of the operation timing chart of each device controlled by the control device 70 will be described with reference to FIG. 12. 9 is different from the timing chart of FIG. 9. After the wiper 60 is operated by the wiper cylinder 94, the coil winding cylinder 92 is operated again to raise and lower the winding wire 54b. It is the same, but otherwise. In this way, the upper thread is released from the thread supply source (not shown) by driving the thread winding device 54 again, so that the upper thread tension can be alleviated to prevent the needle from being broken.

Next, based on FIG. 13 and FIG. 14, the example of another embodiment regarding the suction port 44 of the upper thread holding apparatus 40 is demonstrated.

On the outer circumferential portion of the suction port 144 shown in FIG. 13, a protrusion 144a is provided on the outer side of the wiper movement trajectory to hang the upper thread end. The protrusion 144a has a top 144c that is approximately parallel to the end face 144b of the suction port 144.

On the outer circumferential portion of the suction port 244 shown in FIG. 14, a protrusion 244a is provided on the outer side of the wiper movement trajectory to hang the upper thread end. The protrusion 244a has a top 244c that is approximately parallel to the end face 244b of the suction port 244, which is larger than the top 144c of the suction port 144 in FIG.

Since these suction ports 144 and 244 can securely fasten the upper thread 33 by the top parts 144c and 244c, the upper thread 33 can be hold | maintained more reliably than the suction port 44 of FIG.

In addition, in the embodiment of FIG. 10, it is shown that the holding state of the end of the thread is immediately released after the start of the sewing request is issued at the start of sewing (S1), but is used as the one for preventing the thread knot state described in the conventional example. When the sewing machine motor 80 is rotated to start the sewing process in accordance with the sewing start request, and a predetermined number of needle stitches is detected, that is, when a predetermined number of upper signals from the angle detector 84 are counted ( For example, when the two upper signals are counted), the clamp cylinder 88 is turned off to release the upper thread end held by the upper thread holding device 40, thereby making the end of the thread beautiful at the start of sewing.

In addition, this invention is not limited to said embodiment, A various change is possible.

For example, in the above embodiment, the thread winding member is raised before the thread cutting operation, and the thread winding member is lowered after the end of the thread cutting operation. Instead, the thread winding member is lowered before the thread cutting operation and the thread cutting operation is performed. It is also possible to raise the thread winding member after the end of.

Further, by reciprocating in an oblique direction with respect to the thread path through the thread cutting operation, a method of tensioning and relaxing the thread to secure the remaining length of the upper thread of the required amount can be easily considered.

Moreover, in the case of the structure in which the protrusion part which fastens the upper thread end was provided in the outer peripheral part of the suction port of the holding mechanism and fixed to the upper thread end, the upper thread end can be prevented from being disturbed and the thread end can be reliably maintained.

Moreover, when the protrusion part of a holding mechanism is located upward from the suction port center, since the area | region which operates a cloth becomes large, sewing operation becomes easy.

According to the present invention, the remaining length of the upper thread after the cutting of the thread is increased, so that the upper thread end can be securely held, and the retaining mechanism can be installed at a place away from the needle hole, so that the area for manipulating the fabric can be widened, and the sewing operation becomes easy.

When the control means has a structure in which the wiper is operated to operate after the predetermined time has elapsed after the thread winding member is returned, the remaining length of the upper thread after thread cutting becomes longer, so that the upper thread end can be held more reliably.

In the case where the tip side suction port of the retaining means is disposed so as to face the tip end portion of the wiper when the wiper is returned, the tip of the upper thread is reliably sucked and enveloped, so that the stitches of the stitches can be assured.

If the control means is configured to reciprocate the thread winding member again after operation of the wiper, the thread can be released to prevent the needle from breaking.

Claims (4)

Thread adjusting means disposed on the thread path from the thread source to the sewing needle and imparting a predetermined tension to the upper thread; A wiper having a tip that can intersect the shank trajectory of the needle and capable of enveloping the upper thread end connected to the needle by the tip; and It is provided with a holding means for holding the end of the upper thread promoted by the wiper, In the upper thread clamp device of the sewing machine in which the holding means maintains the end of the upper thread promoted by the wiper after the upper thread is cut below the sewing material, A thread winding member disposed on a thread path between the thread adjusting means and the needle and tensioning or releasing the upper thread by reciprocating; and And a control means for moving the thread winding member prior to the thread cutting operation to maintain the tension state of the upper thread and controlling the thread winding member to be relieved after the end of the thread cutting operation to alleviate the tension state of the upper thread. Upper thread clamp device of sewing machine. The upper thread clamp device of claim 1, wherein the control means controls the wiper to operate after a predetermined time after the thread winding member is returned. According to claim 1 or 2, wherein the wiper is capable of reciprocating movement during the return movement to return the upper thread, the holding means is the front side suction port is disposed so as to face the thread forming portion of the returned wiper Upper thread clamp device of the sewing machine characterized in that there is. The upper thread clamp apparatus of claim 2, wherein the control means reciprocates the thread winding member again after the wiper is operated.