KR101115189B1 - Sewing machine - Google Patents

Abstract

The present invention is to suppress the upper thread from the sewing needle at the start of sewing.

As a sewing machine (10) having a rotary thread take-up (20) which is disposed upstream from the sewing needle (101) on the upper thread path, and imparts a tension that periodically changes to the upper thread at the same period as the vertical movement of the sewing needle (101). The rotary thread take-up 20 has a base portion 21 serving as the rotation center side, and an arm portion 22 for reciprocating the upper thread T along its longitudinal direction by rotating in a state in which the upper thread T is stretched. And the concave portion 23 in which the upper thread T falls from the thread take-up top dead center position 26 of the upper thread T is formed in the arm portion 22, and one needle stitch is formed. It is a structure provided with the position change means 30 which moves the upper thread T to the recessed part 23 before.

Description

Sewing machine {SEWING MACHINE}

1 is an explanatory view of the operation of the sewing machine according to the embodiment of the present invention seen from the front direction;

(A) shows a case where the upper shaft rotation angle is 60 °, (B) shows a case where the upper shaft rotation angle is 80 °, and (C) shows a case where the upper shaft rotation angle is 100 °.

2 is a partially cutaway plan view showing a position changing means and a peripheral configuration thereof;

3 is a front view of the sewing machine omitting the illustration of the rotary thread take-up.

4 is a block diagram showing a control system of the sewing machine.

5 is a plan view of a second embodiment;

6 is a front view of a third embodiment;

7 is a front view of a fourth embodiment.

8 is a front view of a fifth embodiment;

FIG. 9 (A) shows after cutting the upper thread of the sewing machine according to the sixth embodiment, a front view of the state in which the drive of the upper shaft is stopped, and FIG. 9 (B) shows that the operation control means executes the operation control as the position changing means. Front view of the condition.

10 is a front view of a sewing machine of the conventional rotary thread take-up method.

FIG. 11 is a cross-sectional view taken along the line X-X of FIG. 10.

12 is a side view of a sewing machine of the conventional rotary thread take-up method.                 

13 is an operation explanatory diagram when a conventional sewing machine operates properly.

(A) shows a case where the upper shaft rotation angle is 60 °, (B) shows a case where the upper shaft rotation angle is 80 °, and (C) shows a case where the upper shaft rotation angle is 100 °.

14 is a line diagram showing the supply amount of the upper thread (T) supplied by the rotating thread take-up and bobbin toward the sewing needle in accordance with the change of the upper axis reference angle.

15 is an operation explanatory diagram showing a problem of the conventional sewing machine,

(A) shows the case of an upper axis rotation angle of 60 degrees, (B) shows the case of an upper axis rotation angle of 80 degrees, and (C) shows the operation | movement figure which showed the case of an upper axis rotation angle of 100 degrees.

              Description of the main parts of the drawing

10,10B, 10C, 10D, 10E: Sewing machine 20: Rotating thread take-up

21: base portion 22: arm portion

23: recess 25: slot

26: thread take-up top dead center position 30,30A, 30B: position change means

30D: Position change means (blowing means) 31,31A, 31B, 31C: Engagement member

40: upper thread holding means 50: operation control means

101: sewing needle 102: needle bar

T: upper thread

The present invention relates to a sewing machine of a rotary take-up method.

10 is a front view of a conventional rotating thread take-up sewing machine 100, Figure 11 is a cross-sectional view taken along the line X-X of Figure 10, Figure 12 is a side view. The conventional sewing machine 100 is a needle bar (102) for holding the sewing needle 101 at its lower end, and a needle bar swing arm (103) for supporting the needle bar (102) to move up and down and to move up and down at the same time; , The upper shaft 104 which imparts a shanghai driving force to the needle bar 102, the torque fluctuation canceling weight 105 provided at the distal end of the upper shaft 104, and the needle bar crank installed in the eccentric state on the weight 105. (106), a needle bar crank rod (107) for connecting the needle bar crank (106) and the needle bar (102) and transmitting the up and down driving force, and a bottom plate (108) fixed to the tip side of the needle bar crank (106), The rotary thread take-up 109 fixed to the bottom plate 108 is provided (for example, refer patent document 1).

In addition, the sewing machine 100 is located directly downstream of the supply source of the upper thread along the path of the upper thread T, the first tension 110 to impart a predetermined tension to the upper thread, and the second tension 111 of the rotary method. ), The thread guide 112, and the thread raising device 113 for pulling up the upper thread T guided by the first thread guide 112 as necessary, and downstream of the first thread guide 112. A second thread guide 114 disposed further in front of the needle bar 102 while being further downstream of the rotary thread take-up 109 located therein, and a needle bar thread hanger 115 provided on the needle bar 102. Further, further downstream of the sewing needle 101 is provided with a thread cutting device (not shown) for cutting the upper thread (T) in conjunction with the sewing material not shown.

The operation of the rotary thread take-up 109 of the conventional sewing machine 100 will be described. FIG. 13 is an operation explanatory diagram when the operation is performed properly, and FIG. 13 (A) shows a case where the upper shaft rotation angle is 60 °, and FIG. 13 (B) shows a case where the upper shaft rotation angle is 80 °. (C) shows the case where the upper shaft rotation angle is 100 °. In addition, Figure 14 is a line diagram showing the supply amount of the upper thread (T) supplied by the rotary thread take-up and the bobbin to the sewing needle in accordance with the change of the upper axis reference angle. Reference numeral C1 denotes a rotary thread take-up, and reference numeral C2 denotes a bobbin case. In addition, the supply amount is shown to increase as it goes down.

As shown in Fig. 13, the rotary thread take-up 109 has the upper thread T over the arm portion 109a extending radially outward from the rotational center position, and the length thereof according to the change of the angle of the arm portion 109a. The upper thread T moves along the direction, and the upper thread T approaches and is separated from the center of rotation so that the upper thread supply amount is adjusted.

At the position where the upper shaft rotation angle is 80 °, the amount of thread harvested by the rotary thread take-up 109 is the largest, that is, the amount of thread feed is the smallest. The position of the upper thread T becomes a thread take-up top dead center position (the upper thread position of FIG. 13 (B)). Further, the upper thread T falls to the recess 109b formed at the center of rotation rather than the thread take-up top dead center position before the rotation thread take-up 109 rotates to reach 100 ° (Fig. 13C). By this, the upper thread T is supplied toward the sewing needle 101 by the bent portion generated by the recess 109b, and the needle bar 102 moves downward at this timing.

[Patent Document 1] Japanese Patent Application Laid-Open No. 8 (1996) -155171 (Fig. 1)

15 is an operation explanatory diagram showing a problem of the conventional sewing machine 100, Figure 15 (A) shows the case of the upper shaft rotation angle 60 °, Figure 15 (B) shows the case of the upper shaft rotation angle 80 degrees. 15 (C) is an explanatory diagram showing a case where the upper shaft rotation angle is 100 °.

In the above-described sewing machine 100, after the end of the sewing, the upper thread is cut by the thread cutting device, the upper shaft rotation angle is stopped at a position of 60 °. Therefore, when sewing the next time, the upper shaft rotation angle is started from 60 °, at the time of sewing start, because the upper thread (T) fitted to the sewing needle 101 is not fitted to the base fabric, it is free without friction holding force. For this reason, when the upper thread T is easy to receive the influence of the centrifugal force by the rotation of the rotary thread take-up 109, and the upper thread T which should originally move along the arm part 109a toward the rotation center does not move. (FIG. 15 (B)).

In this case, when the needle bar 102 starts lowering in a state where the upper thread does not reach the concave portion 109b and the predetermined thread supply amount cannot be secured, the upper thread T is separated from the sewing needle 101. There was a problem that sewing may not be performed.

An object of the present invention is to suppress the upper thread from falling out of the sewing needle at the start of sewing.

The invention according to claim 1 is a sewing machine provided with a rotating thread take-up which is disposed upstream of a sewing needle on the upper thread path and which gives the upper thread a tension which is periodically changed at the same period as the vertical movement of the sewing needle. A base portion serving as the center of rotation, and an arm portion for reciprocating the upper thread along its longitudinal direction by rotating in a state where the upper thread is extended, and having a concave portion in which the upper thread falls from the thread take-up top dead center position of the upper thread. And position changing means for moving the upper thread to the recess before one needle stitch is formed.

The term " before one needle stitch is formed " means a period before and after the last sewing finish, a period from when it is completely finished until sewing starts, and when the formation of the first needle stitch after the start of sewing is completed (more preferred. Preferably, the period from the first start until the needle bar is at its lowest position.

In the above configuration, the rotary thread take-up rotates at the same period as the up-and-down movement period of the needle bar, so that the upper thread reciprocates along the longitudinal direction of the arm portion, and at this time, the upper thread is moved downstream in accordance with the position in which the upper thread is in sliding contact with the edge of the arm portion. The supply amount of the upper thread supplied changes. The position where the upper thread becomes the highest position is determined in the arm part according to the direction and the shape of the arm part. This position becomes the take-up top dead center. Thereafter, as the upper thread immediately falls into the recessed portion by the rotation of the arm portion, the upper thread approaches the sewing needle and the thread supply amount increases.

By the way, in the above-described configuration, for example, the sewing is made the previous time, and the end of the thread is cut and the upper thread is inserted into the thread fitting hole of the sewing needle, before the shanghaidong of the needle bar is started or before reaching the lowest position. The upper thread is moved by the position changing means to fall through the thread take-up top dead center position to the recessed portion. Therefore, the upper thread is forced to pass through the thread take-up top dead center position before the lower end of the needle bar where the thread supply amount is largely required, and the upper thread is placed in the recess which gives room to the thread supply amount.

Therefore, even if the amount of the upper thread already inserted in the threading hole of the sewing needle is small and the environment is likely to cause the backflow of the upper thread, the upper thread has already passed the thread take-up top dead center. The upper thread is prevented from moving outward by the centrifugal force than the point position, and as the upper thread is positioned in the concave portion, the upper thread supply amount is afforded so that the upper thread can be prevented from falling out of the sewing needle.

Invention of Claim 2 has the structure similar to invention of Claim 1, and a position change means is a structure which has the engagement member which engages with an upper thread, and moves from a thread take-up top dead center position to a recessed part.

In the above configuration, before the vertical movement of the needle bar is started or before reaching the lowest position, the engaging member is engaged with the upper thread engaged with the arm of the rotary thread take-up when the position changing means is operated. In the engaged state, move to the recess of the rotary thread take-up. That is, the engagement member carries the upper thread to the recess.

Invention of Claim 3 has the structure similar to invention of Claim 2, and an arm part has a flat plate shape which an upper thread hangs from the surface to the back surface, and the engaging member extends to the surface side of an upper thread. It is a structure which moves to the recessed part in the state engaged with both of the part extended to the back surface side.

In the above configuration, the engaging member is simultaneously engaged with portions of the upper thread extending toward both sides of the rotary thread take-up to transport to the recess.

Invention of Claim 4 has the structure similar to invention of Claim 3, The slot part along the direction from the thread take-up top dead center position to the recessed part is formed through the flat part of an arm part, and the engaging member is a slot. The upper thread is moved by moving the inside.

In the above configuration, since the engaging member moves the upper thread by moving in the slot along the direction toward the recess, the locking member is simultaneously engaged with the portions of the upper thread extending to both sides of the rotary thread taker to transport to the recess.

The invention as set forth in claim 5 has the same configuration as the invention as set forth in claim 2, and the engaging member has flexibility, and its tip end is brought into sliding contact with the surface of the arm to move the upper thread to the recess. to be.

In the above configuration, when the engaging member is engaged with the upper thread, the leading end of the engaging member is brought into sliding contact with the surface of the arm part of the rotary thread take-up. Therefore, there is no gap between the surface of the arm part and the engaging member, and the upper thread in the overlaid state is more securely engaged with the engaging member and moved.

Invention of Claim 6 has the structure similar to invention of Claim 2, and the engagement member is arrange | positioned upstream rather than rotation thread take-up, and is recessed from the thread take-up top dead center position with respect to the upper thread by the movement. Apply tension in the direction of movement to the negative side.                     

In the above configuration, the engaging member is engaged with the upper thread and gives tension to the upper thread in the direction of movement from the thread take-up top dead center position to the concave portion in the engaging state. Therefore, the upper thread is moved to the recessed portion by the tension.

Invention of Claim 7 has the structure similar to invention of Claim 1, and a position change means is a structure which is a blowing means which blows air from the thread take-up top dead center position to a recessed part side.

In the above configuration, before the vertical movement of the needle bar is started or before reaching the lowest position, air is blown to the upper thread by the position changing means, whereby the upper thread is sent to the recess beyond the thread take-up top dead center position.

The invention described in claim 8 has the same configuration as the invention described in claim 1, and the rotary thread taker is arranged so that the rotation radius outer end moves up and down by the rotational motion, and the recessed portion is more than the thread take-up top dead center position. It is provided in a position close to the base portion, the position changing means is a configuration that is a control means for rotating at a lower speed than when sewing to move the outer radius of the rotating radius of the rotary thread take-up upwards and return to the current position by reverse rotation.

In the above configuration, the upper thread passes through the thread take-up top dead center position to move to the recessed portion by moving the rotation radius outer end of the rotary thread take-up upward. Moreover, even if it passes through the recessed part, when tension is given to the upper thread by the lowering of the sewing needle at the next sewing start, it can move to the recessed part and enter into the recessed part.                     

In addition, the rotation of the rotating thread take-up is performed at a slower speed than normal correction in order to reduce the influence of the centrifugal force.

The invention according to claim 9 has the same configuration as the invention according to any one of claims 1 to 8, and is disposed upstream of the sewing needle on the upper thread path and downstream of the rotary thread taker, Upper thread holding means for regulating the movement of the upper thread in the return direction during operation is provided.

In the above configuration, the upper thread is prevented from being returned from the sewing needle side when the upper thread is moved from the thread take-up top dead center position by the position changing means. Therefore, it is possible to more effectively prevent the upper thread from falling out of the sewing needle.

(Overall Configuration of First Embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, the sewing machine 10 of the rotary thread take-up system which concerns on 1st Embodiment of this invention is demonstrated based on FIG. In addition, in the sewing machine 10 of embodiment, the same code | symbol is used about the same structure as the conventional sewing machine 100 mentioned above, and the overlapping description is abbreviate | omitted.

1 is a view illustrating the operation of the sewing machine 10 in the front direction, FIG. 1 (A) shows a case in which the upper shaft rotation angle is 60 °, and FIG. 1 (B) shows a case in which the upper shaft rotation angle is 80 °. 1 (C) shows a case where the upper shaft rotation angle is 100 °.

The sewing machine 10 is a needle bar (102) for holding the sewing needle 101 at its lower end, a needle bar swing arm (103) for supporting the needle bar (102) to move up and down and to move up and down, and the needle bar An upper shaft 104 which imparts a shank copper driving force to the 102, a torque fluctuation canceling weight 105 provided at the distal end of the upper shaft 104, and a needle bar crank 106 provided in an eccentric state on the weight 105. ), A needle bar crank rod 107 that connects the needle bar crank 106 and the needle bar 102, and transmits a vertical driving force, a bottom plate 11 fixed to the tip side of the needle bar crank 106, and a bottom plate. Rotating thread take-up 20 which is fixedly supported by (11) and imparts a periodically changing tension to the upper thread T at the same period as the vertical movement of the sewing needle 101, and the upper thread before one needle stitch at the start of sewing is formed. (T) will be described later from the thread take-up top dead center position 26 of the rotary thread take-up 20. And a repositioning means for moving into the recess 23, 30 (see Fig. 10).

The sewing machine 10 is also the first tension 110, the second tension 111, the thread guide 112, the thread lifting device 113, the rotary thread take-up 20, along the path of the upper thread (T), A second thread guide 114 and a needle bar thread hanger 115 provided on the needle bar 102 are provided, and a thread cutting device 13 (not shown) is provided further downstream of the sewing needle 101 (see FIG. 4). ). And between the rotary thread take-up 20 and the second thread guide 114, the upper thread holding means (40) and the angle of the upper thread holding means for restricting the movement in the return direction of the upper thread (T) during the operation of the position changing means (30) Motion control means 50 of the configuration.

(Bottom plate)

Hereinafter, each part will be described in detail. The above-described bottom plate 11 is formed in a disc shape and rotates concentrically with the upper shaft 104. The bottom plate 11 is fixed to and supports the base portion 21 of the rotary thread take-up 20 near its center position, and at the same position corresponding to the slot 25 formed in the rotary thread take-up 20 to be described later. The cutout 11a which is penetrated by the same size is formed in (refer FIG. 2 and FIG. 3).

(Rotary thread take-up)

The rotary thread take-up 20 is provided with the base part 21 which becomes a rotation center side, and the arm part 22 which reciprocates the upper thread T along the longitudinal direction by rotating in the state which the upper thread T extended. . In addition, the upper thread T is further rotated from the thread take-up top dead center position 26 so that the recess 23 in which the upper thread T falls is provided in the arm part 22. Same as).

When the upper thread T is sewn, the upper thread T is released from the first thread guide 112 side positioned downward and is bent in the state spanned by the arm part 22 of the rotary thread take-up 20 to be positioned below the second thread guide. Follow the path leading to (114). At this time, the arm portion 22 of the rotary thread take-up 20 is formed in a flat plate shape over its entire length and faces the rear surface (bottom plate 11) on its surface (surface shown in FIG. 1). Face) over the upper thread (T).

And, since the rotary thread take-up 20 rotates about the upper shaft 104 installed in the horizontal direction from the base portion 21, the outer end portion (rotation) in the rotation radius direction of the arm portion 22 (rotation). End) is operated to change its position up and down per revolution.

In addition, the rotary end of the rotary thread take-up 20 is formed with protrusions 24 protruding to both sides along the circumferential direction of the rotation source, the upper thread (T) is the arm portion in accordance with the rotation operation of the rotary thread take-up 20 Reciprocating movement between the protrusion part 24 and the recessed part 23 along the 22 is carried out. In detail, the longitudinal direction of the arm part 22 of the rotary thread take-up 20 becomes close to the horizontal state in the section in which the upper shaft rotation angle is about 60 °, and the recess 23 is opened upward. It becomes a state.

In this state, the upper thread T is located in the vicinity of the protruding portion 24, and when the arm portion 22 further rotates, the protruding portion 24 moves upwards, and the upper thread T is a concave portion which becomes the bottom portion. Go to (23). In this movement process, the position just in front of the recess 23 is formed in a shape projecting slightly toward the opposite side in the depth direction of the recess 23, the portion where the upper thread (T) is bent when passing through the top ( At the highest position, immediately after that, the upper thread T falls into the recess 23 to be out of the highest position. That is, the highest position immediately in front of the recess 23 becomes the thread take-up top dead center position 26.

Moreover, the arm part 22 of the rotary thread take-up 20 is provided with the slot 25 which penetrates the flat surface along the longitudinal direction. The slot 25 extends from the longitudinal intermediate position of the arm portion 22 to the vicinity of the base portion 21. This is used when guiding the upper thread T from the take-up top dead center position 26 to the recess 23 in the position changing means 30, the details of which will be described later.

(Position change means)

2 is a partially cut-away plan view showing the position changing means 30 and its peripheral configuration, and FIG. 3 is a front view of the sewing machine 10 not shown. Position change means 30 is engaged with the upper thread (T) engaging member 31 for moving from the take-up top dead center position to the recess 23 of the rotary thread take-up 20, and engaging member 31 And a support means 32 for supporting the rotation of the locking member 31 in a predetermined direction through the support 32, and the support 32 for supporting the pivot 32 so as to be able to swing up and down at its distal end. It is provided with a contact body 33 for contacting the engaging member 31 by one direction of movement) to promote ups and downs.

The support 32 is fixed to the inside of the sewing machine housing than the bottom plate 11, and is located slightly above and to the left in Figure 1 from the center line of the bottom plate (11). In addition, the support body 32 is supported by the drive means 34 which consists of an electromagnetic solenoid, for example, so that the front-end | tip may advance and retract along the left-right direction.

The front end portion of the support 32 is formed in a hook shape so that the rotational end portion is easy to hook the upper thread (T), the locking member 31 is provided so that the rotation can be rotated along the center line in the vertical vertical direction of FIG. Supported. The engaging member 31 is provided with an elastic force in a direction in which the longitudinal direction of the engaging member 31 crosses along the support 32 by a spring (not shown).

On the other hand, the contact body 33 is fixed to the bottom plate 11 so that its longitudinal direction is parallel to the reciprocating drive direction of the support body 32 while the upper shaft rotation angle is 60 ° and the upper shaft 104 is stopped. have. The contact body 33 is fixedly supported by the bottom plate 11 in a cantilever state. On the other hand, the engaging member 31, the support 32 and the drive means 34 is fixed to the fixed position on the frame side of the sewing machine 10.

Then, in the state where the upper shaft rotation angle is 60 °, the free end side tip of the abutting body 33 and the tip end of the support body 32 are arranged so as to face each other. Then, when the support 32 is driven to the right side of FIG. 2 by the driving means in the state where the upper shaft rotation angle is 60 °, the proximal end side edge of the engaging member 31 supported by the distal end of the support 32 is aligned. In contact with the tip of the contact member 33, the up and down rotation is promoted.

At the time of the undulating rotation, the notches 11a and the slots (11a) and the slot ( Since 25) is formed, the engaging member 31 can rotate smoothly without hitting the bottom plate 11 or the rotary thread take-up 20. Thereby, the engagement member 31 rotates about 90 degrees, and is in a state which is substantially perpendicular to the bottom plate 11 and protrudes out of the bottom plate 11.

Moreover, the upper thread T which is in the state spanned by the arm part 22 of the rotary thread take-up 20 by the up-and-down movement of the engagement member 31 is recessed part 23 toward the base part 21 side. Is moved to the position of.

Moreover, as mentioned above, the notch 11a is formed in the bottom plate 11, and the slot 25 is formed in the rotary thread take-up 20. As shown in FIG. These are all formed so as to be disposed on the relief rotation path of the engaging member 31 in the state of the upper shaft rotation angle 60 °, so as not to interfere with the rotation of the engaging member 31 in the state of the upper shaft rotation angle 60 °. have.

On the other hand, the upper shaft rotation angle 60 ° is the prescribed upper shaft stop angle in a state where the upper thread is cut at the end of sewing by the operation control means 50 described later and the driving of the sewing machine motor 51 is stopped. The upper shaft 104 usually stops at the angle at all times, and when starting sewing, the upper shaft 104 starts to be driven at the angle.

(Upper thread retaining means)                     

The upper thread holding means 40 is disposed immediately in front of the second thread guide 114, and includes pinching means for pinching the upper thread T passing therethrough, and driving means such as a solenoid for driving the pinching operation. The driving means is driven according to the operation control of the operation control means 50 which will be described later, and the upper thread holding means 40 of the upper thread T passing at a predetermined timing at a position immediately before the second thread guide 114. Can regulate movement

Thereby, for example, the upper thread T inserted into the thread fitting hole of the sewing needle 101 can be prevented from being pulled out of the sewing needle 101 by being pulled toward the rotary thread take-up 20.

(Operation control means)

The operation control means 50 will be described with reference to FIG. 4 is a block diagram showing a control system of the sewing machine 10.

As shown in Fig. 4, the operation control means 50 includes a ROM 52 in which various functions to be described later of the sewing machine 10, a control program for executing an operation, control data or various sewing data are written, and a control program. Accordingly, an MPU 51, which is a microcomputer that centrally controls the operations of each unit, and a RAM 53 that stores processing data of the MPU 51 and various data relating to sewing processing in a work area.

Further, the operation control means 50 is a sewing machine motor 12, the drive means of the position changing means 30, the thread cutting device 13, the first tension 110, the second tension 111, the thread lifting device 113, the upper thread holding means 40, and the operation input means 14 are connected via a driver not shown, and operation control can be executed on them. In addition, the sewing machine motor 12 is a stepping motor, and outputs a reference position signal to the operation control means 50 every one revolution of the output shaft. On the other hand, the operation control means 50 executes the drive control for the sewing machine motor 12, and can recognize the current variation angle from the reference position signal.

In addition, the operation input means 14 is connected to the operation control means 50. The operation input means 14 inputs an instruction for cutting the thread at the start of sewing or at the end of the sewing. The operation timing of the first tension 110, the second tension 111, the thread lifting device 113, and the like, the tension strength, the lifting amount, and the like, are set with respect to the rotation angle. By the program stored in the ROM 52 of the operation control means 50, the MPU 51 controls the operation of each unit on the basis of the respective settings at the time of sewing.

In addition, by the program stored in the ROM 52, the MPU 51 receives an instruction to cut the thread and controls the operation of the sewing machine motor 12 so that the upper shaft rotation angle of the upper shaft 104 stops at 60 degrees. The thread cutting operation of the thread cutting device 13 is performed.

Furthermore, after stopping the drive of the sewing machine motor 12, the MPU 51 drives the drive means of the upper thread holding means 40 to perform the operation control for pinching the upper thread and at the same time drive the upper thread position changing means 30. The solenoid which is the means 34 is driven to control operation to move the engaging member 31 from the retracted position on the left side of FIG. Thereby, the upper thread T is moved along the arm part 22 of the rotary thread take-up 20 to the recessed part 23, and the upper thread T falls to the said recessed part 23. As shown in FIG.

Subsequently, the MPU 51 drives the driving means of the upper thread holding means 40 to release the pinching state of the upper thread and simultaneously drives the solenoid which is the driving means 34 of the upper thread position changing means 30. Operation control to move the engaging member 31 to the retracted position on the left side from the drive position on the right side of FIG.

(Explanation of operation of sewing machine)

The operation of the sewing machine 10 having the above-described configuration will be described with reference to FIGS. 1 and 2.

That is, when sewing start is input from the operation input means 14, the MPU 51 starts the drive of the sewing machine motor 12 at the set rotation speed. At this time, the first tension 110, the second tension 111, and the thread lifting device 113 operate at a predetermined driving timing and a predetermined driving amount. Thereby, sewing is performed according to the drive amount of each part.

Subsequently, when the instruction for cutting the thread is input by the operation input means 14, the upper shaft rotation angle of the upper shaft 104 stops at 60 degrees, and the thread is cut by the thread cutting device 13. As a result, the upper thread in front of the sewing thread 101 is cut in a state where the upper thread T is fitted by a predetermined length from the thread fitting hole of the sewing needle 101.

Further, as shown in Fig. 1A, the upper thread holding means 40 is driven and pinched so that the upper thread T does not return to the upstream side. In this state, the support body 32 is projected by the driving means 34 of the position changing means 30, whereby the edge portion of the proximal end of the engaging member 31 is brought into contact with the contact body 33, and is illustrated. The engagement member 31 rotates up and down against the spring that is not. In response to the ups and downs rotation, the engaging member 31 moves along the slot 25 of the rotary thread take-up 20, so that both the portion located on the front surface of the arm portion 22 and the portion located on the rear side of the upper thread T Is engaged with the engaging member 31, the upper thread (T) falls to the recess 23 to move to the recess 23 side.

Thereafter, the support 32 is retracted to return to the retracted state from the protruding state again, and the contact state with the contact body 33 is released, and the engaging member 31 moves toward the support 32 by the elasticity of the spring. Fall down and return to the retracted position. In addition, the upper thread holding state of the upper thread holding means 40 is released.

Thereby, in the next time sewing, sewing starts in the state which the upper thread T fell to the recessed part 23 of the rotary thread take-up 20, and ensures the upper thread length downstream of the rotary thread take-up 20 is sufficient. Therefore, even when the sewing needle 101 is lowered, the amount of the upper thread returned from the downstream side of the sewing needle 101 can be reduced, so that the upper thread T from the sewing needle 101 can be suppressed from falling out. Therefore, it is possible to prevent sewing defects to improve the reliability of the sewing machine.

In addition, since the slot 25 is formed in the rotary thread take-up 20 to engage with the upper thread T in a state where the engaging member 31 is inserted, the engaging member 31 is formed by the arm portion 22. Simultaneously engaged with both parts of the upper thread (T) extending to both sides, the upper thread (T) is moved to the recess 23 more reliably, more effectively avoiding the upper thread (T) from falling out of the sewing needle (101) Since it is possible, the reliability of the sewing machine 10 can be further improved.

In addition, since the engaging member 31 moves in the slot 25 and moves the upper thread T, the engaging member 31 is wound around both sides of the arm part 22 of the rotary thread take-up 20. It is possible to adopt a straight simple shape as shown in Fig. 2 without forming a complicated shape such as the above, and the productivity of the device can be improved.                     

(Etc)

In the operation control means 50 of the sewing machine 10, the operation control to move the upper thread T to the recess 23 of the rotary thread take-up 20 after the upper thread cutting operation at the end of sewing, the upper thread T ) May be performed until the needle bar of the first needle stitch reaches the lowest position after starting the next sewing thereafter. If it is such a timing, the effect which suppresses that the edge part of the upper thread T falls out from the sewing needle 101 can be acquired.

In addition, it is the same also about other embodiment mentioned later.

(2nd embodiment)

5 shows a second embodiment of the position changing means.

In this embodiment, since the structure other than the said position change means 30A is the same as that of the sewing machine 10, overlapping description is abbreviate | omitted.

FIG. 5 is a plan view of the position changing means 30A, and the arrangement in the sewing machine is supported by a frame not shown from the outside of the bottom plate 11, unlike the position changing means 30. As shown in FIG.

That is, the position changing means 30A includes a link body 32A supported by the frame so as to be able to swing around the vertical direction in the vertical direction, a locking member 31A fixed and supported by the base portion of the link body 32A, Driving means for imparting the swinging motion of the link body 32A is provided.

The engagement member 31A swings in accordance with the swing of the link body 32A, and its tip portion is formed in a key shape. In addition, the tip end portion of the engaging member 31A is swinged into the slot 25 of the rotary thread take-up 20 at the rotational angle of 60 ° by the swing, and is arranged to move along the slot 25.

In the above configuration, after the thread cutting operation, the upper thread holding means 40 is driven so that the upper thread T is pinched so as not to return to the upstream side. In this state, the link body 32A is rocked in a predetermined direction by the drive means of the position changing means 30A, whereby the engaging member 31A is rocking. That is, the tip portion of the engaging member 31A moves along the slot 25 of the rotary thread take-up 20, and the portion located on the surface side of the arm portion 22 in the upper thread T is the engaging member 31A. The upper thread (T) falls to the concave portion 23 by moving toward the concave portion 23 while being engaged.

Thereafter, the drive means swings the link member 32A in the reverse direction, and the engaging member 31A swings in a direction in which the distal end thereof is spaced apart from the recess 23 so that the upper thread holding state of the upper thread holding means 40 is maintained. Is released.

Even when the position changing means 30A having such a configuration is applied, the same effects as those of the sewing machine 10 described above can be obtained.

(Third embodiment)

3 shows a third embodiment of the position changing means.

In the present embodiment, redundant description is omitted in the fact that the slot 25 is not required to be formed in the rotary thread take-up 20 and that the configuration other than the position changing means 30B is the same as that of the sewing machine 10. Shall be.

6 is a front view of the sewing machine 10B having the position changing means 30B.                     

The position changing means 30B is fixedly supported on the link body 32B supported by the frame and the base portion of the link body 32B so as to be able to swing around the horizontal direction (direction parallel to the upper axis 104). A locking member 31B and a motor 33B as drive means for imparting a swinging motion of the link member 32B are provided.

The engaging member 31B swings in accordance with the swinging of the link body 32B, and the front end thereof is slid into contact with the front side face portion (face portion shown in FIG. 6) of the rotary thread take-up 20. At the same time, the engaging member 31B is formed of a flexible or elastic material. Moreover, arrangement | positioning set so that the front-end | tip part of the engagement member 31B may slide in contact with the concave part 23 from the position outside the rotation radius rather than the thread take-up top dead center position 26 by 60 degree of rotation by an oscillation. It is.

In the above configuration, the upper thread holding means 40 is driven after the thread cutting operation so that the upper thread T is pinched so as not to return to the upstream side. In this state, the drive means 33B of the position changing means 30B is driven to rotate in a predetermined direction to oscillate the link body 32B in a predetermined direction, whereby the engaging member 31B of the rotary thread take-up 20 Sliding contact on the front face from the position immediately before the top of the thread take-up top dead center position to the position of the recess 23, the upper thread (T) is dragged by the front end portion to move toward the recess 23, the recess 23 Drop the upper thread (T).

Thereafter, the driving means 33B swings the link member 32B in the reverse direction, and the engaging member 31B swings in the direction in which the distal end thereof is spaced apart from the recess 23, so that the upper thread holding means 40 The upper thread holding state is released.

Even when the position changing means 30B having such a configuration is applied, the same effect as that of the sewing machine 10 described above can be obtained. Furthermore, a gap is formed between the surface of the arm portion 22 and the engaging member 31B. Since the upper thread T in the state spanned by the arm part 22 can be captured more reliably and moved to the recessed part 23, the upper thread T is moved to the recessed part 23 very reliably, and the upper thread It is possible to more effectively avoid the T from slipping away from the sewing needle 101 and further improve the reliability of the sewing machine 10B.

(Fourth Embodiment)

4 shows a fourth embodiment of the position changing means.

In the present embodiment, the redundant description is omitted in the fact that the slot 25 is not required to be formed in the rotary thread take-up 20 and that the configuration other than the position changing means is the same as that of the sewing machine 10. .

7 is a front view of the sewing machine 10C having a position changing means.

The position changing means is on the same plane as the bottom plate 11, and in the arrangement from the thread guide 112 to the rotary thread take-up 20, the latch supported to be movable in the vertical direction along the slit formed in the frame. 31 C of engagement members, and drive means, such as a solenoid, which is not shown in figure which switches the said engagement member 31C to an up-down 2 position.

The engaging member 31C moves upwardly and substantially vertically from the vicinity of the thread guide 112, thereby moving from the thread take-up top dead center position 26 with an upper shaft rotation angle of 60 ° with respect to the upper thread T toward the concave portion 23. Apply tension in the direction of movement.

In addition, if tension can be applied to the upper thread T in the direction moving from the take-up top dead center position 26 toward the concave portion 23, the engaging member 31C is not limited to the above-described moving direction. no.

In the above configuration, the upper thread holding means 40 is driven after the thread cutting operation so that the upper thread T is pinched so as not to return to the upstream side. In this state, the drive means of the position changing means moves the engaging member 31C upward from the position near the thread guide 112. Thus, tension is applied in the direction in which the engaging member 31C moves from the thread take-up top dead center position 26 toward the recess 23 with respect to the upper thread T, thereby dropping the upper thread T into the recess 23. Let's do it.

Thereafter, the driving means lowers the engaging member 31C to a position near the thread guide 112 to release the tensioning state on the upper thread T, and at the same time, the upper thread holding state of the upper thread holding means 40 is released. do.

Even when the position changing means 30C having such a configuration is applied, the same effect as that of the sewing machine 10 described above can be obtained, and the engaging member 31C directly directs the upper thread T to the recess 23. Since the guide member is guided by tensioning rather than moving, the latching member 31C does not necessarily need to be arranged so as to reach the target position, thereby improving the degree of freedom in terms of layout design.

(Fifth Embodiment)

5 shows a fifth embodiment of the position changing means.

In the present embodiment, redundant description is omitted in the fact that the slot 25 is not required to be formed in the rotary thread take-up 20 and that the configuration other than the position changing means 30D is the same as that of the sewing machine 10. Shall be.

8 is a front view of the sewing machine 10D having a position changing means.

The position changing means 30D is supported by the frame and moves the upper thread T toward the concave portion 23 from the thread take-up top dead center position 26 of the rotary thread take-up 20 in the state of the upper shaft rotation angle of 60 °. Blowing means for blowing at an angle that can be.

The blowing means may be, for example, a fan that draws in and blows outside air around, or may blow out a compressor body enclosed in a cylinder or the like.

In the above configuration, after the thread cutting operation, the upper thread holding means 40 is driven so that the upper thread T is pinched so as not to return to the upstream side. In this state, the position changing means 30D performs blowing. As a result, the upper thread T moves from the thread take-up top dead center position 26 toward the recess 23 by the blowing air, and reaches the recess 23.

Thereafter, the position changing means 30D stops and the upper thread holding state of the upper thread holding means 40 is released.

Even when the position changing means 30D having such a configuration is applied, almost the same effect as that of the sewing machine 10 described above can be obtained, and the position changing means 30D directly directs the upper thread T to the recess 23. Since it is guided by blowing instead of moving to the upper side, the member engaged with the upper thread T and the driving means for carrying out the movement are unnecessary, and the operation of releasing from the upper thread guided state is unnecessary. In addition, the productivity can be improved by simplifying the control. In addition, since the blowing means is not strict in the blowing direction, it is possible to improve the degree of freedom in terms of layout design.

(Sixth Embodiment)

9 shows a sixth embodiment of the position changing means.

In the present embodiment, there is no need to form the slot 25 in the rotary thread take-up 20, and the configuration except that the position changing means is realized by the operation control in the operation control means 50 described above. Since the same as the sewing machine 10, duplicate description will be omitted.

FIG. 9 (A) shows after cutting the upper thread of the sewing machine 10E, and is a front view of the state in which the driving of the upper shaft 104 is stopped, and FIG. 9 (B) shows the operation control by the operation control means 50 as the position changing means. This is a front view of the state which is running.

As described above, the rotary thread take-up 20 is provided in a configuration in which the recess 23 is closer to the base 21 than the thread take-up top dead center position 26. That is, since the thread take-up top dead center position 26 is located outside the rotation radius than the concave portion 23, the MPU 51 of the operation control means 50 has an upper shaft 104 in accordance with a program stored in the ROM 52 in advance. ) Is stopped at a position where the rotation angle is 60 °, and after cutting the upper thread, the angle at which the tip portion of the arm portion 22 is located above the base portion 21 (that is, rotated 90 degrees further, that is, The upper shaft rotation angle (up to 150 degrees) is driven to rotate the upper shaft 104 at a slower speed than the normal rotation speed, and the operation of the sewing machine motor 12 is controlled to return to the position of the rotation angle 60 degrees by reverse rotation. As a result, the operation control means 50 executes a function as the position changing means.                     

In the above configuration, the upper shaft 104 is stopped at the upper shaft rotation angle of 60 °, and the upper thread T is cut. Further, the driving means of the upper thread holding means 40 is driven to bring the upper thread into a pinching state (Fig. 9 (A)). In this state, the upper thread T is located at the arm portion 22 of the rotary thread take-up 20, outside the thread take-up top dead center position 26 in the rotation radius direction, and is used to control the operation of the operation control means 50. As a result, the upper shaft 104 is driven to rotate 90 degrees further clockwise. It is preferable that the rotation speed at this time is a slow speed in the range which does not interfere with the next sewing operation. That is, in order not to provide centrifugal force to upper thread T (FIG. 9 (B)).

As a result, the upper thread T moves in the falling direction and passes through the thread take-up top dead center position 26 to enter the recess 23. Thereafter, the upper shaft 104 is driven to rotate 90 degrees counterclockwise so that the rotary thread take-back is returned to the position as shown in Fig. 9A. In addition, the upper thread holding state of the upper thread holding means 40 is released.

Even when the position changing means of the second to sixth embodiments is executed by the operation control means 50, the same effect as that of the sewing machine 10 described above can be obtained, and the position changing means is directly connected to the upper thread ( Since the member which moves T) to the recessed part 23, and the drive means which performs the movement of the member are not required, productivity can be improved by simplifying the apparatus structure.

In the invention according to claim 1, since the upper thread is moved to the recess by passing through the thread take-up top dead center position in advance by the position changing means, the amount of the upper thread inserted in the thread fitting hole of the sewing needle is small, and the environment in which the upper thread is easily reversed Even if the upper thread has already passed, the upper thread has already passed the thread take-up top dead center, so that the upper thread is prevented from moving outward by centrifugal force than the position of the top take-up top dead center, and the upper thread is placed in the recess to allow the upper thread to be supplied. Since the upper thread can effectively avoid falling out of the sewing needle, it is possible to improve the reliability of the sewing machine to prevent sewing failure.

In the invention according to claim 2, since the engaging member of the position changing means is moved to the concave portion in a state of engaging with the upper thread, the upper thread is conveyed in a physical contact state, and the upper thread moves to the concave portion very reliably. By more effectively avoiding the upper thread from the sewing needle, it is possible to further improve the reliability of the sewing machine.

In the invention according to claim 3, since the engaging member of the position changing means is configured to simultaneously engage with portions of the upper thread extending to both sides of the rotating thread take-up, and to carry the engaging member to the concave, only the front and rear surfaces. Compared to the case of engaging with the part extending to either side, such as caught on the part extending to the other side occurs, it is possible to further suppress the effect of the injustice problem that the upper thread is not sufficiently moved, It is possible to reliably move the upper thread to the concave portion more effectively avoiding the upper thread from falling out of the sewing needle to further improve the reliability of the sewing machine.

In the invention according to claim 4, since the engaging member moves the upper thread by moving in the slot along the direction toward the recess, the upper thread is moved to the recess very reliably to improve the reliability of the sewing machine and at the same time insert the through hole. Since it is passed through, it is not necessary to form the engaging member into a complicated shape such as winding it on both sides of the rotary thread take-up, thereby improving productivity of the apparatus.

According to the invention of claim 5, since the distal end of the engaging member moves in sliding contact with the arm surface of the rotary thread take-up, there is no gap between the surface of the arm portion and the engaging member, so that the upper thread in the extended state Since it is surely captured and moved to the concave portion, it is possible to more effectively avoid the upper thread from moving to the concave portion and the upper thread from falling out of the sewing needle, thereby further improving the reliability of the sewing machine.

In the invention according to claim 6, since the engaging member tensions the upper thread and guides the upper thread into the recess, the engaging member itself does not have to be directly disposed in the vicinity of the recess of the rotary thread take-up. A wide choice of can improve design freedom.

The invention according to claim 7 is a configuration in which the upper thread is moved from the thread take-up top dead center position in the rotary thread take-up to the recess by blowing, so that a member engaged with the upper thread and guided to the recess is unnecessary and guided toward the recess. Since it is easy to set aside in the blowing direction, the degree of freedom of arrangement of the configuration for the blowing is high, so that the degree of freedom of design can be improved.

The invention according to claim 8 is a configuration in which the upper thread is moved to the recess by the operation control of rotating the rotating end of the rotating thread take-up upward, and thus, the member for directly moving the upper thread to the recess as the position changing means and the movement of the member. There is no need for a driving means to execute the above, and the productivity can be improved by simplifying the device configuration.

According to the invention of claim 9, the movement of the upper thread returning direction at the time of operation of the position changing means is controlled by the upper thread holding means, so that the upper thread from the sewing needle can be more effectively avoided.

Claims (9)

A sewing machine having a rotating thread take-up which is disposed upstream from a sewing needle on the upper thread path and which imparts a periodically changing tension to the upper thread at the same period as the vertical movement of the sewing needle. The rotary thread take-up unit has a base portion which is the rotation center side, and an arm portion for reciprocating the upper thread along its longitudinal direction by rotating in the state where the upper thread is spread, Forming a recess in which the upper thread falls from the thread take-up top dead center position of the upper thread, And a position changing means for moving said upper thread to said recess before one needle stitch is formed. The method of claim 1, The position changing means, the sewing machine characterized in that it has a locking member for engaging the upper thread to move from the thread take-up top dead center position to the concave portion. 3. The method of claim 2, The arm portion has a flat plate portion in which the upper thread extends from the surface to the back surface thereof, The locking member is a sewing machine characterized in that for moving to the concave portion in the state coupled to both of the portion extending toward the surface of the upper thread and the portion extending toward the rear surface. The method of claim 3, In the flat plate portion of the arm portion, a slot along the direction from the thread take-up top dead center position toward the recess is formed. Sewing machine characterized in that the engaging member moves the upper thread by moving in the slot. 3. The method of claim 2, And said engaging member has flexibility, and its front end is slid in contact with the surface of said arm portion to move said upper thread to said recessed portion. 3. The method of claim 2, The engaging member is disposed on the upstream side of the rotary thread take-up, and the tensioner in the direction moving from the thread take-up top dead center position to the concave portion with respect to the upper thread by the movement. The method of claim 1, And the position changing means is a blowing means for blowing air from the thread take-up top dead center position toward the concave portion. The method of claim 1, The rotary thread take-up machine is installed so that the rotation radius outer end moves up and down by the rotation operation, and the recess is disposed in a position closer to the base portion than the thread take-up top dead center position. The position changing means is a sewing machine, characterized in that the control means for rotating at a lower speed than when sewing to move the outer radius of the rotating radius of the rotary take-up upward and return to the current position by reverse rotation. The method according to any one of claims 1 to 8, A sewing machine having an upper thread side upstream from the sewing needle on the upper thread path and a lower side than the rotary thread take-up, and having upper thread holding means for restricting the movement of the upper thread in the return direction when the position changing means is operated. .

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