CN1458327A - Sewing machine - Google Patents

Abstract

A sewing machine has: a wire cutting mechanism (10), a presser-bar-lifting mechanism (30), a back off mechanism (50) and a driving mechanism for driving the mechanisms, wherein the driving mechanism is a single pulse motor (80) and is provided with: a 1 st cam (61) having a wire cutting action part for converting the rotary driving force of the pulse motor into the driving force corresponding to the wire cutting mechanism, and a 2 nd cam (62) having a wire rewinding action part and a presser bar lifting action part for converting the rotary driving force of the pulse motor into the driving force corresponding to the back off mechanism and the presser bar lifting mechanism. The 1 st cam and the 2 nd cam are arranged with a phase difference by the rotation of the pulse motor according to the sequential action of the wire cutting mechanism, the back off mechanism and the presser-bar lifting mechanism. On a sewing machine with a thread cutting mechanism, a presser-bar-lifting mechanism and a back off mechanism, simplification of the mechanism and control can be realized, the cycle period is prevented from slowing, and the action of the presser-bar-lifting mechanism is restrained according to requirements, thereby realizing high efficiency of sewing operation.

Description

sewing machine

technical field

The invention relates to a sewing machine with a thread cutting mechanism, a presser foot lifting mechanism and a thread wiping mechanism.

Background technique

In recent years, sewing machines having a thread cutting mechanism for cutting the thread immediately after sewing, a presser foot lifting mechanism for moving the presser foot device upward, and a thread wiping mechanism for loosening the upper thread have been put into practical use.

Above-mentioned conventional sewing machine, owing to be provided with each drive mechanism that is used to drive thread cutting mechanism, thread trimming mechanism, presser foot lifting mechanism, so structure is complicated and parts quantity is many, and sewing machine is also cumbersome, large-scale, and because as sewing Most of the main operators of sewing machines in the factory are women, so the operation of using heavy benzene becomes a burden, and there is a problem that the work efficiency is reduced due to the need to expand the sewing space.

However, among sewing machines having such devices, there are also cycle sewing sewing machines. When using this cycle sewing sewing machine, after forming one cycle stitch, it is sometimes necessary to continue to form another cycle stitch near this stitch. For example, when nailing a 4-hole button on the fabric, first pass through two of the four holes to form a stitch, and then cut the thread so as not to leave a transition line, and then form a stitch through the remaining two holes In this case, it is best to carry out continuous stitching without moving the presser unit upwards from the loop stitch used to form the first two holes to the loop stitch used to form the remaining two holes, while keeping the fabric as it is. sewing work.

In addition, when it is not desired to form a transition line between the first loop stitch and the next loop stitch for the sake of appearance, it is necessary to perform the thread cutting operation and the thread rewinding operation after forming the first loop stitch.

The present applicant first applied for the invention of a sewing machine that uses the same drive mechanism to operate the thread trimming mechanism and the presser foot lifting mechanism. , the presser foot lifting mechanism is also linked, and the presser foot will temporarily leave, so there is a problem that the fabric moves, and the starting position of the next stitch deviates from the desired position.

In particular, on a sewing machine of the cloth-pressing type with the presser foot device clamping the button, once the presser foot device moves upward, the button and the cloth also move upward together, and then when the presser foot device descends, or when the button is If the position is deviated or the fabric is pressed down while the fabric is folded, the needle may break once the stitches are formed.

The object of the present invention is to reduce the number of parts of a sewing machine having a thread cutting mechanism, a presser foot lifting mechanism, and a thread wiping mechanism, and reduce the weight and size of the sewing machine.

And, according to the need, the method of controlling the action of the presser foot lifting mechanism can be used to relieve the discomfort of the sewing operation, and realize the high efficiency of the work while improving the quality of the sewn product.

In addition, the work efficiency is improved by shortening the sewing cycle regardless of the sewing conditions.

Contents of the invention

In order to solve the above problems, the sewing machine described in 1 of the present invention, as shown in Figures 1 to 10, has:

Equipped with a thread cutting mechanism 10 for cutting the thread connected to the needle under the sewing object, a movable blade 15d, a presser foot lifting mechanism 30 for lifting the presser foot 71 that presses the cloth by elastic force from above the sewing object, and a cross The thread winding mechanism 50 that moves on the thread path between the needle and the sewing object and has a thread rewinding piece (sliding piece 58 ) that pulls the thread cut by the thread cutting mechanism on the sewing object is characterized in that it has : single drive motor (pulse motor 80), and

a first cam 61 that is rotatable in conjunction with the above-mentioned driving motor and that has a thread cutting cam portion X2 that operates the above-mentioned thread cutting mechanism by changing the rotational phase; and

It is rotatable in conjunction with the drive motor, and includes a thread reeling cam part that operates the thread threading mechanism by a change in rotational phase having a predetermined phase difference with respect to the first cam, and a thread rewinding cam part that operates the thread winding mechanism by a change in the rotational phase. The second cam 62 of the presser lift cam unit Y2 that operates the presser lift mechanism, and

a first connecting member (thread cutting link 11) arranged to connect the above-mentioned thread cutting cam portion of the above-mentioned first cam to the above-mentioned thread cutting mechanism, and

A second connecting member (presser foot lifting link 31) arranged to connect the thread rewinding cam portion and the presser foot lifting cam portion of the second cam to the thread threading mechanism and the presser foot lifting mechanism;

The predetermined phase difference between the first cam and the second cam is configured such that the thread cutting mechanism and the presser foot lifting mechanism are operated after the thread cutting mechanism completes the thread cutting operation by the rotation of the driving motor.

According to the first aspect of the present invention, since the thread cutting mechanism, the presser foot lifting mechanism and the thread threading mechanism can be driven by a single drive motor, the number of parts can be reduced and the weight of the sewing machine can be reduced, and the sewing machine can be miniaturized, cheap and can improve work efficiency.

In addition, these thread trimming mechanisms, thread trimming mechanisms, and presser foot lifting mechanisms are always operated at certain timings. For example, the delay time from the end of the thread trimming and thread rewinding operations to the start of the presser foot lifting operation can always be constant. As a result, cycle-cycle delays can be prevented.

The second aspect of the present invention is the sewing machine according to the first aspect of the present invention, wherein the drive motor can rotate forward and reverse,

The thread cutting cam portion of the first cam, the thread reversing cam portion of the second cam, and the presser foot lifting cam portion are formed so that the operation of the thread cutting mechanism, the thread wiping mechanism, and the presser foot lifting mechanism and the driving The same respectively symmetrical shape regardless of the direction of rotation of the motor.

According to the second aspect of the present invention, the operations of the thread trimming mechanism, the thread threading mechanism, and the presser lifting mechanism and the rotation of the drive motor are constituted by the thread cutting cam portion of the first cam, the thread reversing cam portion of the second cam, and the presser foot lifting cam portion. The symmetrical shapes that perform the same action regardless of the direction, so no matter which direction the drive motor rotates, the same thread trimming, thread rewinding, and presser foot lifting actions can be performed. Therefore, smooth sewing work can be realized. Furthermore, according to such a structure, after thread trimming, only the thread rewinding motion is performed without the presser foot lifting motion, and the thread rewinding motion and the presser foot lifting motion are performed after thread trimming.

The third aspect of the present invention is the sewing machine according to the second aspect of the present invention, as shown in Fig. 8, Fig. 11, Fig. 12 and Fig. 14, characterized in that:

The above-mentioned first cam 61 and the above-mentioned second cam 62,

A non-operating area that is arranged to hold the thread cutting mechanism 10, the thread-trimming mechanism 50, and the presser foot lifting mechanism 30 in which none of the mechanisms operates,

And it is equipped with a control mechanism CPU90, which can be flexibly switched and realized: the first control mode of rotating the above-mentioned driving motor in the rotation direction that makes the above-mentioned thread cutting mechanism, the above-mentioned thread-swiping mechanism and the above-mentioned presser foot lifting mechanism operate in this order, and After turning the drive motor in the direction in which the thread cutting mechanism and the thread wiping mechanism operate in this order, turn the drive motor in the opposite direction before operating the presser foot lifting mechanism, and set the rotation position of the drive motor at The second control mode in the above-mentioned non-operating area.

According to the third aspect of the present invention, since there is a first control mode that can be flexibly switched and realized to rotate the drive motor in the rotation direction that makes the thread cutting mechanism, the thread lifting mechanism and the presser foot lifting mechanism act in this order, and in the direction of making the thread cutting mechanism, the thread lifting mechanism After the thread mechanism rotates the drive motor in the rotation direction in which this sequence operates, and then rotates the drive motor in the opposite direction before operating the presser foot lifting mechanism, and makes the rotation position of the drive motor in the non-operating area, it is the control mechanism of the second control mode. Reliable sewing operations corresponding to various situations can be performed.

Thereby, for example, when the 4-hole button is nailed to the cloth without leaving the thread, the presser foot of the presser foot device is not moved upward, and the cloth is kept intact for continuous sewing, because no pressure due to The foot lifting mechanism operates and the presser foot of the presser foot device moves upward to cause discomfort such as fabric deviation, so high efficiency of sewing operations can be realized.

In addition, when it is not desired to form a connecting line between the previous stitch and the next stitch for the sake of appearance, first, the second control mode is realized by the control mechanism, and the thread is cut after the previous stitch is formed. Action and thread rewinding action and suppress the action of the presser foot lifting mechanism, and then, after forming the next stitch, use the control mechanism to realize the first control mode, so that the presser foot can be lifted at the end and the sewing can be completed. Therefore, since the connecting line connecting the previous stitch and the next stitch is not formed, the quality of the sewn product can be improved and high efficiency of work can be realized.

In addition, when it is not desired to form a connecting line connected between the first stitch and the next stitch for the sake of appearance, first, by realizing the second control mode by the control mechanism, after the first stitch is formed, the thread cutting mechanism and The thread threading mechanism acts, and suppresses the action of the presser foot lifting mechanism, and then, the next stitch can be formed by realizing the first control mode by the control mechanism, and finally the presser foot is raised to finish sewing. Therefore, since the connecting line between the first stitch and the next stitch is not formed, the quality of the sewn product can be improved.

A fourth aspect of the present invention is the sewing machine according to the third aspect of the present invention, characterized in that:

A movable area changing mechanism CPU90 is provided for changing the movable area of the thread rewinding piece (sliding piece 58 ) of the threading mechanism when the threading mechanism 50 operates in the second control mode.

According to the fourth aspect of the present invention, since the above-mentioned rewinding piece of the above-mentioned thread-swiping mechanism is changed when the thread-swiping mechanism operates in the second control mode (that is, when the thread-swiping mechanism continues to operate and the presser foot lifting mechanism does not operate), The movable area change mechanism of the movable area, so the movable area of the rewinding piece can be set appropriately according to the thickness of the fabric to be sewn or the thickness of the suture used for sewing. Therefore, unnecessary swinging of the rewinding reel can be suppressed, and the time required for the rewinding reel's swinging can be shortened, thereby improving sewing efficiency.

According to the inventions 5 to 7, the structure can be simplified, and weight reduction and miniaturization can be realized.

Description of drawings

FIG. 1 is an explanatory view for explaining a thread cutting mechanism, a presser foot lifting mechanism, and a thread threading mechanism included in a backtacking sewing machine according to an embodiment of the present invention.

Fig. 2 is a plan view showing operations of a fixed knife member and a movable knife member constituting the thread cutting mechanism shown in Fig. 1 during thread cutting.

Fig. 3 is an enlarged perspective view of the presser foot lifting mechanism and the thread wiping mechanism shown in Fig. 1 .

Fig. 4 is an enlarged perspective view showing a state before the operation of the thread-swiping mechanism shown in Fig. 1 .

Fig. 5 is an enlarged side view showing the state before the operation of the thread threading mechanism and the presser foot lifting mechanism shown in Fig. 1 .

Fig. 6 is an enlarged perspective view showing an operating state of the thread-swiping mechanism shown in Fig. 4 .

Fig. 7 is an enlarged side view showing the operating state of the thread threading mechanism and the presser foot lifting mechanism shown in Fig. 5 .

Fig. 8(a) is a perspective view of a cam member included in the backtacking sewing machine shown in Fig. 1, (b) is a plan view of a first cam of the cam member shown in (a), and (c) is a top view of a first cam of the cam member shown in (a). The top view of the 2nd cam of the cam assembly.

Fig. 9 is an explanatory view for explaining the thread cutting and presser foot raising operation of the backtacking sewing machine shown in Fig. 1 .

Fig. 10 is an explanatory view for explaining the thread cutting and presser foot raising operation of the backtacking sewing machine shown in Fig. 1 .

Fig. 11 is a block diagram illustrating an electrical configuration of a bartacking sewing machine according to an embodiment of the present invention.

Fig. 12 is a flowchart for explaining the control operation of the backtacking sewing machine according to the embodiment of the present invention.

Fig. 13 is a diagram showing an example of control data for controlling the backtacking sewing machine according to the embodiment of the present invention.

Fig. 14 is a schematic view showing the control operation of the backtacking sewing machine according to the embodiment of the present invention, centering on the movement amounts of the thread trimmer link and the presser foot lift link.

Among the figure: 10-thread trimmer mechanism, 11-thread trimmer connecting rod, 11a-fitting pin, 11b-curved part, 11c-lower end, 12-support pin, 13-thread trimmer connecting rod, 14-fixed cutter part, 14a- Fixed blade, 15-movable cutter part, 16-installation plate, 17, 21, 55-screw, 18, 41-shading part, 18a, 41a-shading plate, 19, 40-photo-circuit breaker, 20-movable Knife connecting part, 22-connecting pin, 23-thread cutting lever, 24-movable knife link, 25-fixing screw, 30-presser foot lifting mechanism, 31-presser foot lifting link, 31a-upper end, 31b -bending part, 31c-lower end, 32-presser foot lifting drive link, 33-connecting arm, 34-shaft member, 35-driving arm, 35a-front end, 36-presser foot lifting driving foot, 37-support Rod, 38-pin, 42-fulcrum pin, 43-roller, 44-coil spring, 50-wire mechanism, 51-sliding piece connecting rod, 51a-rear end, 51b-front end, 51c-horizontal Hole, 52-sliding sheet L-shaped connecting rod, 52a-fitting pin, 53-coil spring, 54-limit pin, 56-sliding sheet connecting plate, 57-support plate, 58-sliding sheet, 58a-one end, 58b -Thread unwinding part, 59-support plate, 60-cam member, 61-1st cam, 61a-cam groove, 62-2nd cam, 62a-cam surface, 70-cloth press device, 71-presser foot, 72- Support seat, 73-presser foot drive link, 73a-one end, 73b-upper extension, 73c-joint pin, 74-axis component, 80-pulse motor, 81-spindle, 90-CPU, 91-ROM, 92-RAM, 93-operation panel, 94-button switch, 95-start switch, 100-spindle motor, S1-initial rotation direction setting step, S2-cloth pressing step, S3-data address initialization step, S4-sewing Data reading step, S5-thread cutting and rewinding step, S6-other command implementation step, S7, S8-data address updating step, S9-presser foot lifting step, S10-pulse motor stop step, S11-mark reversal step, S12-pulse motor reverse step, X1, Y1-arc part, X2-variable curvature part, Y2-ellipse part.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In this embodiment, taking the sewing machine of the present invention as an example, a backtack sewing machine for forming zigzag stitches with flat seams will be described. The backtacking sewing machine of this embodiment sews according to the prescribed sewing pattern stored in the unillustrated memory by the cooperative action of the needle and the shuttle, and after sewing, according to the tangent included in the sewing pattern Command or presser foot lift command starts thread trimming and presser foot lift operation at the specified timing.

The backtack sewing machine of this embodiment includes: a thread trimming mechanism 10 for cutting the upper thread and the lower thread immediately after the sewing operation is finished, and a presser foot lifting mechanism 30 for raising the presser foot 71 of the presser foot device 70 before and after the sewing operation After cutting the upper thread with the thread cutting mechanism 10 and before the presser foot 71 of the presser foot device 70 rises, the upper thread that is connected to the cloth is poured out from the needle and the thread end on the needle side is drawn to the thread-striking mechanism 50 on the cloth. Hereinafter, the thread cutting mechanism 10, the presser foot lifting mechanism 30, and the thread wiping mechanism 50 will be described with reference to FIGS. 1 to 10 .

FIG. 1 is an explanatory view for explaining the configurations of the thread cutting mechanism 10 , the presser lifting mechanism 30 , and the thread wiping mechanism 50 . Fig. 2 is a plan view showing the operation of the fixed knife member 14 and the movable knife member 15 constituting the thread cutting mechanism 10 during thread cutting. 3 , 4 and 6 are enlarged perspective views of the presser foot lifting mechanism 30 and the thread-swiping mechanism 50 , and FIGS. 5 and 7 are enlarged perspective views of the presser-foot lifting mechanism 30 and the thread-swiping mechanism 50 .

8( a ) is a perspective view of a cam member 60 (to be described later), FIG. 8( b ) is a top view of the first cam 61 of the cam member 60 , and a top view of the second cam 62 of the cam member 60 in FIG. 8( c). 9 and 10 are plan views centering on the cam member 60 for explaining the thread trimming and presser foot lifting operation.

First, the structure of the thread cutting mechanism 10 will be described. The thread cutting mechanism 10 is composed of a thread cutting link 11, a thread cutting link 13, a fixed cutter member 14, a movable cutter member 15, and the like.

The thread cutting link 11 as the first connecting member is an elongated rod-shaped body slightly bent in the middle. On the upper end portion of the thread cutting link 11 , as shown in FIG. 9 , a fitting pin 11 a that fits into a cam groove 61 a of a first cam 61 of a cam member 60 described later is provided. In addition, the thread cutting link 11 is rotatably attached to an unillustrated sewing machine frame by means of a support pin 12 on the bent portion 11b.

The lower end 11c of the thread cutting link 11 is mounted on the mounting plate 16 by screws 17 in a state of flexibly rotating together with the rear end of the thread cutting link 13 . A light shielding member 18 having a light shielding plate 18 a is fixed to an end portion of the mounting plate 16 . On the other hand, in the vicinity of the light shielding member 18, a photointerrupter 19 is fixed to an unshown sewing machine frame. The photo-interrupter 19 is a device for detecting the origin position of the thread cutting mechanism 10. When the light-shielding plate 18a is located between the light-emitting element and the light-receiving element of the photo-interrupter 19, it outputs a signal indicating the origin position to the above-mentioned control circuit.

The thread cutting connecting rod 13 is an elongated rod-shaped member slightly bent upward at a predetermined point, and its front end portion 13a reaches directly below the needle plate 2a. As shown in FIG. 2 , the movable cutter connecting member 20 is rotatably connected to the front end portion 13 a with screws 21 . Also, the thread cutting lever 23 is fixed to the movable knife connecting member 20 . A connecting pin 22 fixed to the needle plate 2 a passes through the movable knife connecting member 20 and the thread cutting lever 23 , and the movable knife connecting member 20 and the thread cutting lever 23 can rotate around the connecting pin 22 at the same time. One end 24 a of the movable cutter link 24 is flexibly connected to the front end of the thread cutting lever 23 .

The central portion of the movable cutter member 15 is rotatably connected to the other end 24b of the movable cutter link 24 . The end portion 15 a of the movable cutter member 15 is rotatably mounted on a fixing screw 25 . Fixing screws 25 are fixed to the needle plate 2a. The front end of the movable cutter part 15 is formed with a thread-reversing portion 15b that does not cut off but only loosens the upper thread and the bottom thread during the cutting action, and grabs the suture that is loosened by the thread-reversing portion 15b and bends inwardly. The thread part 15c, and the movable blade 15d for cutting the suture. In the vicinity of the movable knife member 15, there is provided a fixed knife member 14 fixed to the needle plate 2a by screws, and at the front end of the fixed knife member 14, there is formed a needle thread clamp between the movable knife edge 15d and the movable knife edge 15d. and the fixed blade 14a that cuts off the bobbin thread.

Next, the operation of the thread cutting mechanism 10 will be described. The thread cutting mechanism 10 mainly having the above-mentioned structure is in the state shown in FIG. The support pin 12 is rotated in the counterclockwise direction (direction of arrow A) in FIG. 1 , and its lower end moves forward. Therefore, as shown in FIG. 2( b ), the thread cutting connecting rod 13 moves forward, and since the movable knife connecting member 20 is pushed by the screw 21, the movable cutting knife connecting member 20 and the thread cutting lever 23 center on the connecting pin 22. turn.

By the movement of the thread cutting lever 23 , the movable knife link 24 connected to the front end is pushed backward, and the movable knife member 15 rotates clockwise around the fixing screw 25 . Due to this turning action, the upper thread and the lower thread are straightened out by the thread unwinding portion 15b, and only the upper thread and the lower thread to be cut are positioned between the thread gripping portion 15c and the fixed blade 14a.

On the other hand, the thread cutting link 11 rotates clockwise around the support pin 12, and when its lower end returns to the rear, the various components constituting the thread cutting mechanism 10 perform opposite actions. That is to say, the movable cutter member 15 is rotated from the state shown in Fig. 2(b), and at this time, the upper thread and the lower thread are rotated by the thread gripping part 15c while grasping the upper thread and the lower thread, so that the upper thread and the lower thread are brought close to the fixed blade. 14a, as shown in FIG. 2(c), the movable blade 15d is matched with the fixed blade 14a to cut the suture. The movable cutter member 15 continues its reversal and returns to the state of Fig. 2(a).

Next, the structure of the presser foot lifting mechanism 30 will be described. The presser foot lifting mechanism 30 is composed of a presser foot lifting link 31 , a presser foot lifting drive link 32 , a presser foot driving arm 35 , a presser foot driving foot 36 and the like.

The presser foot lifting link 31 as the second connecting member is slightly in the shape of a "k", and is rotatably mounted on an unillustrated sewing machine frame with a fulcrum pin 42 at the bent portion 31b. The roller 43 (refer to FIG. 9 ) is fixed on the lower end portion 31c of the presser foot lifting link 31, and the roller 43 and the cam surface 62a of the second cam 62 of the cam member 60 described later (refer to FIG. 8(a) , (c)) docking.

In addition, although it is not shown in FIG. 1 , a small pin protruding inward is provided on the presser foot lifting link 31 actually. The coil spring 44 is hung on the small pin, and the coil spring 44 applies a pulling force to the presser lift link 31 so that the roller 43 always abuts against the cam surface 62 a of the presser lift cam portion 62 . One end 32a of the presser foot lift drive link 32 is flexibly connected to the upper end 31a of the presser foot lift link 31 .

The presser foot lifting drive link 32 is a long flat bar-shaped part, and its other end 32 b is connected to the lower end of the link arm 33 in a flexible and rotatable manner. A light shielding member 41 having a light shielding plate 41a bent in the horizontal direction is fixed to a side surface near one end portion 32a of the presser lift drive link 32 . On the other hand, in the vicinity of the light shielding member 41, a photointerrupter 40 composed of a light emitting element and a light receiving element is fixed to an unillustrated sewing machine frame. The photo-interrupter 40 is used to detect the original position of the presser foot lifting mechanism 30. When the light-shielding plate 41a is located between the light-emitting element and the light-receiving element of the photo-interrupter 40, it outputs an indication to the control circuit not shown in the original position. location signal.

The linkage arm 33 is fixed at its upper end by an abutment to a shaft member 34 flexibly and rotatably supported on a frame not shown, and is formed as a horizontally long presser foot drive arm on the inner side of the linkage arm 33. 35, is fixed by the abutment and swings relative to the shaft part 34 with the shaft part 34 as a fulcrum. Therefore, when the link arm 33 swings around the shaft member 34 as a fulcrum, the presser driving arm 35 also swings around the shaft member 34 in conjunction with the swing of the link arm 33 . A vertically long presser foot driving leg 36 is rotatably connected to the front end portion 35 a of the presser foot driving arm 35 .

The presser foot driving foot 36 has a substantially U-shaped cross-section in the horizontal direction, and abuts against the abutment pin 73a of the cloth presser 70 when its lower edge portion 36a is descending. One end of the horizontally long support rod 37 is rotatably supported in the middle of the presser foot driving foot 36 . The other end of the support rod 37 is rotatably mounted on an unillustrated sewing machine frame through a pin 38, and the direction in which the presser foot driving foot 36 descends is restricted by the support rod 37 .

A gap of a predetermined size is provided between the presser driving foot 36 and the abutment pin 73c of the cloth presser 70 located below it. Therefore, the presser driving foot 36 abuts against the abutment pin 73c of the cloth presser 70 only after the gap portion from the start of the descent.

Here, the presser foot driving foot 36 and the interlocking arm 33 are configured to interlock as described above, and a slide link link 51 of the thread-wiping mechanism 50 described later is connected to the interlocking arm 33 . Therefore, at the same time that the presser driving foot 36 starts to descend, the thread-swiping mechanism 50 described later also operates. On the other hand, since the above-mentioned gap is provided between the presser foot driving leg 36 and the contact pin 73c of the cloth press device 70, the contact pin of the cloth press device 70 will not move after a predetermined time has elapsed since the drive leg 36 starts to descend. 73c is depressed, and the presser foot 71 rises.

That is, the gap provided between the presser foot driving foot 36 and the contact pin 73c of the cloth press device 70 serves as a difference between the start of the operation of the thread setting mechanism 50 and the start of the operation of the presser foot lifting mechanism 30. The function of the differential mechanism.

In addition, the cloth presser 70 arranged below the presser foot lifting mechanism 30 is constituted by a presser foot 71 , a support base 72 , a presser foot drive link 73 , and the like.

The support base 72 is fixed on a sewing machine table (not shown), and has a function of supporting the presser foot drive link 73 . The presser foot driving link 73 is rotatably mounted on the support base 72 by the shaft member 74 as shown in FIG. In addition, an upper extension portion 73 b is provided on a part of the presser foot driving link 73 . A contact pin 73c is provided at the front end of the upward extension portion 73b, and the contact pin 73c is disposed near the lower side of the presser driving foot 36 of the presser lifting mechanism 30 (see FIGS. 1 and 3).

Once the presser foot driving foot 36 of the presser foot lifting mechanism 30 descends, the abutment pin 73c is pressed downward by the presser foot driving foot 36, and the presser foot driving link 73 moves toward the reverse side of FIG. 1 around the shaft member 74. Turn clockwise, presser foot 71 rises.

Next, the configuration of the thread-swiping mechanism 50 will be described. The wire threading mechanism 50 is composed of a sliding piece connecting rod 51, a sliding piece L-shaped connecting rod 52, a sliding piece connecting plate 56, a sliding piece (rewinding piece) 58, and the like.

The thread cutting mechanism 50 has the function of pouring out the upper thread connected to the cloth from the needle and pulling the thread end on the needle side to the cloth after the upper thread is cut by the thread cutting mechanism 10 and before the presser foot 71 of the presser foot device 70 is raised. Function. The sliding piece of the thread thread mechanism 50 is connected to the rear end portion 51a of the link 51, and is connected to the middle of the link arm 33 of the presser foot lifting mechanism 30 (see FIG. 1 ).

A horizontally long horizontal hole 51c is formed at the front end portion 51b of the slider connection link 51 . In addition, near the front end portion 51b, a sliding piece L-shaped link 52 that is rotatably mounted on an unillustrated sewing machine frame with a mounting screw 55 at a curved portion formed in a substantially L-shape is disposed. And, the engaging pin 52 a fixed to the upper end of the L-shaped link 52 of the sliding piece passes through the horizontal hole 51 c of the connecting link 51 of the sliding piece.

The coil spring 53 in a stretched state is installed on the inner surface of the sliding piece connecting link 51 . One end of the helical spring 53 is hung on a part of the sliding piece connecting rod 51, and the other end is hung on the matching pin 52a of the sliding piece L-shaped connecting rod 52. Therefore, the sliding piece L-shaped connecting rod 52 is always screwed. The spring 53 applies a force to the right in FIG. 3 .

However, in the vicinity of the sliding piece L-shaped link 52, a stopper pin 54 is protrudingly fixed to an unillustrated sewing machine frame. The thread threading mechanism 50 continues to operate and the presser foot lifting drive link 32 used for the action of the presser foot lifting mechanism 30 moves further to the rear. The sliding piece L-shaped connecting rod 52 also stops when abutting against the limit pin 54 .

In addition, the force of the coil spring 53 is not strong enough to pull the slide piece L-shaped link 52 backward due to the resistance of the slide piece connection link 51 and the presser foot lifting mechanism 30 . Therefore, only when the presser foot lifting mechanism 30 operates and the connecting link 51 of the sliding piece moves backward, the coil spring 53 can pull and move the L-shaped connecting rod 52 of the sliding piece backward through the engaging pin 52a.

The vertically long sliding piece connection plate 56 is rotatably connected to the front end portion of the sliding piece L-shaped link 52 . An extension portion 56a extending rearward in FIG. 1 is formed at the lower end of the slider connecting plate 56 . In the vicinity of the slider connecting plate 56, a support plate 57 fixed to an unillustrated sewing machine frame is fixed. The sliding piece 58 , which is slightly L-shaped in plan view, is flexibly and rotatably connected to the support plate 57 by mounting screws 59 at its bent portion.

One end portion 58a of the sliding piece 58 is connected to the extension portion 56a in a flexible and rotatable manner. A thread unwinding portion 58b protruding forward is provided at a lower end portion of the sliding piece 58, and the upper thread is unwound by the thread unwinding portion 58b. FIG. 4 is an enlarged perspective view showing the vicinity of the thread-swiping mechanism 50 in a pre-operation state. In addition, FIG. 5 is an enlarged side view showing the presser foot lifting mechanism 30 and the thread-swiping mechanism 50 in a pre-operation state.

Next, the operations of the presser foot lifting mechanism 30 and the thread wiping mechanism 50 will be described. With the presser foot lifting mechanism 30 and the thread wiping mechanism 50 having the above structure, after the upper thread and the lower thread are cut, when the presser foot lifting link 31 rotates counterclockwise (in the direction of arrow B) in FIG. The rod 32 is pulled backward. Due to this movement, the interlocking arm 33 swings rearward about the shaft member 34 , thereby causing the presser driving arm 35 to also rotate clockwise about the shaft member 34 . With the rotation of the presser driving arm 35 , the presser driving leg 36 descends while being restricted by the support rod 37 .

On the other hand, by the swing of the linkage arm 33 to the rear, the sliding piece connecting link 51 moves backward, so the engaging pin 52a in the horizontal hole 51c also moves backward due to the tension of the coil spring 53, so the sliding piece L-shaped The connecting rod 52 rotates counterclockwise in FIG. 1 around the screw 55 . The sliding piece connecting plate 56 rises due to the rotation, and one end 58a of the sliding piece 58 rises due to the rising, and the sliding piece 58 rotates in the counterclockwise direction of FIG. Noodles.

In addition, the sliding piece L-shaped connecting rod 52 stops rotating when it collides with the limit pin 54, and the part where the sliding piece connecting connecting rod 51 moves backward is the sliding of the matching pin 52a along the horizontal hole 51c, and does not Affects the action of the L-shaped connecting rod 52 of the sliding sheet. FIG. 6 shows an enlarged perspective view of the operating state of the wire threading mechanism 50 . In addition, an enlarged side view of the operating state of the presser foot lifting mechanism 30 and the thread wiping mechanism 50 is shown in FIG. 7 .

At this time, since there is a gap between the presser driving foot 36 and the contact pin 73c of the cloth press device 70 as described above, the lowering of the presser driving foot 36 is delayed for a predetermined time from the start, and after the end of the reverse thread , the presser foot driving foot 36 presses down the contact pin 73c of the cloth presser device 70, and moves the presser foot 71 upward.

In addition, when the presser foot driving leg 36 is raised by turning the presser foot lifting link 31 clockwise in FIG. 1 , the presser foot 7 is lowered by its own weight. And, because the linkage arm 33 returns to the original position, the sliding piece connection link 51 returns to the front, and the wire-wiping mechanism 50 returns to the state shown in FIG. 4 and FIG. 5 as a whole.

As described above, the thread trimming mechanism 10 operates from the thread trimming link 11 , and the presser lift mechanism 30 and the thread swiping mechanism 50 operate from the presser lift link 31 . The driving force of the pulse motor 80 is transmitted to the thread cutting link 11 and the presser lift link 31 through the cam member 60 at predetermined timings, and they are operated. Hereinafter, the pulse motor 80 and the cam member 60 will be described.

A pulse motor 80 as a driving motor of the present invention is fixed to a sewing machine frame (not shown). The output shaft 81 of the pulse motor 80 is fixed to the central portion of the cam member 60 described later. The cam member 60 is rotated by a predetermined angle by the pulse motor 80 .

The pulse motor 80 is driven and controlled by a control unit CPU 90 described later. The CPU 90 controls the operation of the cam member 60 while counting the rotation direction of the pulse motor 80 and the number of pulses in operation for each operation of the thread cutting mechanism 10, the presser foot lifting mechanism 30, and the thread wiping mechanism 50.

Cam member 60, as shown in Figure 1 and Figure 8 (a), viewed from the front of Figure 1, its profile consists of the first cam 61 of a slightly circular box comprising a straight line part and the integrally located cam on the front side. The second cam 62 constitutes.

The first cam 61, as shown in FIG. 8(a), has a substantially heart-shaped cam groove 61a formed on its inner side. The fitting pin 11a of the thread cutting link 11 is fitted into the cam groove 61a and slides along the surface thereof.

Figure 8(b) shows the shape of the cam groove 61a. P1 to P7 are key angular positions in one circle shown for convenience. The cam groove 61a forms an arc at an equal distance from the rotation center C1 from P2 to P7 through P3. On the other hand, between P2 and P7 centered on P1, a symmetrical shape facing P1 and shortening the distance from the rotation center is formed. Hereinafter, the section from P2 through P3 to P7 will be referred to as "arc section X1", and the section from P2 to P7 around P1 will be referred to as "variable curvature section X2".

As shown schematically in FIG. 8( b ), as the cam member 60 rotates, the fitting pin 11 a moves relative to the cam groove 61 a. For this purpose, for example, when the pulse motor 80 is rotated in a predetermined direction (positive direction) to move the fitting pin 11a from P2 of the arc portion X1 through P3 to P7, the distance between the fitting pin 11a and the rotation center C1 constant, and the tangent connecting rod 11 does not rotate.

On the other hand, the fitting pin 11a gradually approaches the rotation center C1 when moving from P7 to P1. Therefore, the thread cutting link 11 rotates in the counterclockwise direction in FIG. 1, and the movable cutter member 15 moves over the fixed blade 14a as described above.

Then, when the fitting pin 11a moves from P1 to P2, it gradually moves away from the center of rotation C1, and the thread cutting link 11 rotates clockwise in FIG. The upper and lower threads are cut between the fixed blades 14a. The same is true when the pulse motor 80 rotates in the opposite direction and the fitting pin 11a moves from P2 to P7 via P1. That is, the variable curvature portion X2 is the thread tangential cam portion of the present invention.

The second cam 62 is integrally fixed on the front side of the thread cutting cam portion 61, as shown in FIG. Q1 to Q7 in FIG. 8( c ) are key angular positions in one circle shown for convenience. The cam surface 62a forms an arc at an equal distance from the rotation center C1 from Q6 to Q3 through Q1.

On the other hand, between Q3 and Q4, and between Q6 and Q5, a symmetrical shape is formed facing Q4 and Q5 respectively, and the distance from the rotation center becomes longer. And, between Q4 and Q5, a circular arc having an equal distance from the rotation center C1 is formed. Hereinafter, the section from Q6 through Q1 to Q3 is referred to as "arc section Y1", and the section from Q3 including Q4, Q5 to Q6 is referred to as "elliptical section Y2".

As shown schematically in FIG. 8( c ), as the cam member 60 rotates, the roller 43 relatively moves along the cam surface 62 a. For this reason, for example, the pulse motor 80 rotates in the above-mentioned positive direction, and when the roller 43 moves from Q6 through Q1 to Q3, the distance between the roller 43 and the rotation center C1 remains unchanged, and the presser foot lifting link 31 does not rotate. .

On the other hand, the roller 43 gradually moves away from the rotation center C1 while moving from Q3 to Q4. Therefore, the presser foot lifting link 31 rotates counterclockwise in FIG.

In addition, the pulse motor 80 rotates in the opposite direction, the roller 43 returns from Q4 to Q3 and gradually approaches the rotation center C1, the presser foot lift link 31 rotates clockwise as shown in Figure 1, and the presser foot lift drive link 32 returns to the front , the presser foot 71 descends while the sliding piece 58 returns to the pre-action position. Also between Q6-Q5, when facing Q5, the presser foot lifting link 31 is rotated counterclockwise in FIG. 1 by the roller 43, and rotates clockwise when facing Q6. That is, the elliptical portion Y2 is the thread rewinding cam portion and the presser lifting cam portion of the present invention.

In addition, the reason why an arc is formed between Q4-Q5 of the second cam 62 is as follows. The presser foot 71 seldom moves up and down continuously, for example, after going down, sewing and then going up. When the roller 43 reaches Q4 or Q5 and lifts the presser foot 71, even if the pulse motor 80 stops, a mechanical deviation occurs to the stop of the rotation of the corresponding cam member 60, passing through Q4 or Q5 slightly. Since the arc between Q4 and Q5 is formed, even if the stop is delayed and the rotation exceeds Q4 or Q5, the start of the descending action can be prevented.

The first cam 61 and the second cam 62, as described above, consider the mutual phase relationship and the respective abutment positions of the fitting pin 11a and the roller 43 in consideration of cutting the suture and then lifting the presser foot. Specifically, the angles between P1-P7, P1-P2, Q1-Q7, and Q1-Q2 are all the same (angle ml), when the fitting pin 11a moves from P7 to P2 through P1 , it happens that the roller 43 also moves from Q7 to Q2 through Q1. That is, during the thread cutting operation, the presser foot lifting mechanism 30 does not operate.

In addition, when the roller 43 lifts the presser from Q3 to Q4, the fitting pin 11a moves between P3-P4, and the thread cutting mechanism 10 does not operate. Even when the roller 43 moves between Q5-Q6 to activate the presser foot lifting mechanism 30, the thread cutting mechanism 10 does not operate because the fitting pin 11a moves between P5-P6. In addition, when the roller 43 is located between Q4-Q5, the fitting pin 11a is located between P4-P5.

In addition, the cam member 60 is provided with a region (non-operating region) where the driving force of the pulse motor 80 is not transmitted to any one of the thread cutting mechanism 10 , the presser lifting mechanism 30 , and the thread wiping mechanism 50 . That is, when the fitting pin 11a is located between P2-P3 and the roller 43 is located between Q2-Q3, and, when the fitting pin 11a is located between P6-P7 and the roller 43 is located between Q6-Q7, The thread cutting mechanism 10, the presser foot lifting mechanism 30 and the thread wiping mechanism 50 do not operate. That is, the regions between P2-P3 and P6-P7 in FIG. 8(b), and the regions between Q2-Q3 and Q6-Q7 in FIG. 8(c) are inactive regions.

Next, operations of the thread cutting mechanism 10, the presser foot lifting mechanism 30, and the thread wiping mechanism 50 around the cam member 60 will be described with reference to FIGS. 9 and 10 . 9 and 10 are explanatory diagrams for explaining the operation centering on the cam member 60 . In addition, here, the operation|movement which operates the thread cutting mechanism 10, the thread cutting mechanism 50, and the presser foot lifting mechanism 30 in this order is demonstrated.

First, the thread cutting operation is started from the state I shown in Fig. 9(a). In this state I, the fitting pin 11 a is located on the arc portion X1 of the cam groove 61 a of the first cam 61 , and the roller 43 is in contact with the arc portion Y1 of the cam surface 62 a of the second cam 62 .

From this state I, as the pulse motor 80 rotates in the forward direction (direction of arrow F in FIG. 9 ), the cam member 60 rotates clockwise in FIGS. 1 and 9 . The fitting pin 11a moves relatively along the arc portion X1, and the roller 43 moves along the arc portion Y1, but soon, the fitting pin 11a moves to the boundary position between the arc portion X1 and the variable curvature portion X2 (Fig. 8(b) State II of P7).

From then on, the fitting pin 11a starts to move in the variable curvature portion X2, and the thread cutting mechanism 10 starts to operate. Then, once the fitting pin 11a is in the state III (refer to FIG. 9(c)) that reaches the central portion (P1 of FIG. 8(b)) of the variable curvature portion X2, the movable cutter member 15 is in the above-mentioned state of FIG. (b) The maximum mobile state. In addition, regardless of the state II or state III, the roller 43 moves in the arc portion Y1, and the presser foot lifting mechanism 30 does not operate.

Then, the fitting pin 11a enters from P1 into P2 in the variable curvature portion X2. During this process, the movable cutter member 15 performs a recovery action, and catches the upper thread and the lower thread in the middle of its movement, and contacts with the fixed cutter. Component 14 fits and cuts the upper thread and the lower thread. Then, the fitting pin 11a reaches the terminal position (P2) of the variable curvature part X2, and is in state IV shown in FIG. 10(a). At this point, the operation of the thread cutting mechanism 10 ends. And, the cam member 60 continues to rotate in the same direction, the fitting pin 11a moves between P2-P3 in FIG. 8(b) (non-operating region), and the roller 43 moves between Q2-Q3 in FIG. 8(c). (no action area). At this moment, the thread cutting mechanism 10, the presser foot lifting mechanism 30 and the thread threading mechanism 50 are not in action.

Next, as shown in Fig. 10(b), the roller 43 reaches the ellipse Y2 of the cam surface 62a (position Q3 in Fig. 8(c)) (state V), and since then, the presser foot lifting link 31 starts to move toward the ellipse in Fig. 10(b). 1 and FIG. 10 in the counterclockwise direction, and continue the rotation of the sliding piece 58 of the thread-swiping mechanism 50 to become the lifting action of the presser foot 71. Then, as shown in Figure 10 (c), the roller 43 is in the state VI between Q4-Q5, the rotation of the sliding piece 58 of the thread-wiping mechanism 50 and the lifting action of the presser foot 71 are completed, and the pulse motor is stopped at this time. 80. In addition, regardless of the state V or state VI, since the fitting pin 11a moves along the arc portion X1, the thread cutting mechanism 10 does not operate.

Next, the electrical configuration of the backtacking sewing machine of this embodiment will be described with reference to FIG. 11. FIG. Fig. 11 is a block diagram for explaining the electrical configuration of the backtacking sewing machine of this embodiment.

The backtack sewing machine has: a control mechanism CPU (Central Processing Unit) 90 for driving and controlling various devices such as a pulse motor 80, a ROM (Read Only Memory) 91 for storing various information such as control data and programs, and a CPU 90 for storing information. RAM (Random Access Memory) 92 based on various data read from ROM 91 or data calculated by programs, etc., operation panel 93 for inputting sewing conditions, etc., push button switch for driving cloth pressing device 70 for pressing cloth 94. Start switch 95, pulse motor 80, spindle motor 100, etc. for sewing start.

The CPU 90 uses the RAM 92 as a work area, and performs various calculations based on graphic data and sewing programs stored in the ROM 91 . Specifically, the CPU 90 selects and changes sewing data based on data input from an operation panel connected through an input interface not shown. And, when the instruction signal is input from the button switch 94 and the start switch 95 connected through the input interface not shown, the CPU 90 controls the pulse motor 80 and the spindle motor 100 through the output interface not shown according to the above-mentioned graphic data, so that they Carry out the specified sewing work.

Next, a specific control operation example of the backtacking sewing machine of this embodiment will be described with reference to a flowchart and the like. Fig. 12 is a flowchart for explaining the control operation of the backtacking sewing machine according to the embodiment of the present invention, and Fig. 13 is an example diagram of control data (graphic data) for controlling the control operation of the backtacking sewing machine according to the embodiment of the present invention. 14 is a schematic view showing the control operation of the backtacking sewing machine according to the embodiment of the present invention, centering on the movement amounts of the thread trimmer link 11 and the presser foot lift link 31.

First, the control operation of the backtacking sewing machine of this embodiment will be described with reference to the flowchart in Fig. 12 . First, under the control of the CPU 90, the flag for determining the rotation direction of the pulse motor 80 is set to an initial value (initial rotation direction setting step: S1). Then, when the user operates the push button switch 94, the CPU 90 receives the operation signal from the push button switch 94, drives the pulse motor 80, rotates the cam member 60, and moves the cloth press device 70 through the presser foot lifting link 31 and the like. The presser foot 71 descends to press the cloth (cloth pressing step: S2).

Subsequently, the CPU 90 sets the address of the graphics data read from the ROM 91 as an initial value (data address initialization step: S3). And, when the operator does not operate the push button switch 94, the CPU 90 does not drive the pulse motor 80 until the push button switch 94 is operated.

Next, once the user operates the start switch 95 that is used to start sewing, the CPU 90 that has received the operation signal from the start switch 95 reads the sewing data including the graphic data of the ROM91 (sewing data read-in step: S4) , and carry out sewing according to the sewing data. In addition, when the user does not operate the start switch 95, the CPU 90 waits until the start switch 95 is operated without reading the sewing data.

Next, when the instruction continuous with the sewing data in the graphic data of ROM91 is "thread cutting instruction" (for example, the data address 1056 of Fig. 13 (a)), CPU 90 drives pulse motor 80, and makes cam member 60 move from Fig. The state of I in 9(a) passes through the state V in Fig. 10(b), and then rotates slightly in the clockwise direction (arrow F direction in Fig. 9 and Fig. 10), and only the thread cutting mechanism 10 and the thread threading mechanism 50 operations (thread cutting and thread rewinding step: S5).

At this time, since there is a gap between the lower end 36a of the presser foot driving foot 36 of the presser foot lifting mechanism 30 and the abutment pin 73c of the cloth presser 70, the cam member 60 moves from the state V in FIG. In the state of turning slightly clockwise, the lower end 36a of the presser foot driving leg 36 does not abut against the contact pin 73c of the cloth presser 70, and the presser foot 71 does not rise.

In addition, when the instruction that is continuous with the sewing data in the pattern data of ROM91 is not "thread cutting instruction" (for example, the data address 1001 of Fig. 13 (a)), CPU 90 executes other instructions in the pattern data (for example, empty After sending instruction) (other instruction implementation steps: S6), update the address in the graphic data (data address update step: S7), and return to the sewing data read-in step S4, and continue the sewing operation.

After the thread cutting/rewinding step S5, the CPU 90 updates the address of the graphic data in the ROM 91 (data address updating step: S8). When the instruction following the thread cutting instruction in the graphic data is "sewing end instruction" (for example, the data address 107C of Fig. 13(a)), the CPU 90 drives the pulse motor 80 to rotate to the state VI of Fig. 10(b) The cam member 60 actuates the presser foot lifting mechanism 30 (presser foot lifting step: S9), and the sewing operation ends.

In addition, when the instruction following the thread cutting instruction in the graphic data is not "sewing end instruction" (for example, "jump data" of data address 1057 in Fig. 13(a)), CPU 90 only stops pulse motor 80 for a prescribed time (Pulse motor stop step: S10). At this time, the cam member 60 is in the state of turning slightly clockwise from the V state in FIG. Foot 71 does not rise.

Then, CPU90, will determine the sign reversal of pulse motor 80 rotation direction (mark reversal step: S11), reverse pulse motor 80 makes cam member 60 reach the state IV of Fig. 10 (a) and after making it stop (pulse motor Reverse step: S12), return to other instructions to implement step S6, and continue the sewing operation.

When the cam member 60 is between the state IV of Fig. 10(a) and the state V of Fig. 10(b), as mentioned above, the fitting pin 11a is located between P2-P3 of Fig. 8(b) (no action area), and the roller 43 is located between Q2-Q3 in Figure 8(c) (non-action area). Therefore, the thread cutting mechanism 10, the presser foot lifting mechanism 30, and the thread wiping mechanism 50 do not operate.

As mentioned above, the control operation to end the sewing operation through the sewing data reading step S4, thread cutting and rewinding step S5, data address updating step S8 and presser foot lifting step S9 is the "first control mode" in the present invention. . This first control mode can be realized regardless of forward rotation and reverse rotation of the pulse motor 80 . This is because the thread cutting cam portion X2 of the first cam 61 of the cam member 60, the thread rewinding cam portion of the second cam 62, and the presser foot lifting cam portion Y2 are functions of the thread cutting mechanism 10, the thread wiping mechanism 50, and the presser foot lifting mechanism 30. The same respective symmetrical shapes operate regardless of the rotation of the pulse motor 80 .

On the other hand, after the sewing data reading step S4, the thread cutting and rewinding step S5, the data address updating step S8, the pulse motor stop step S10, the mark reversing step S11 and the pulse motor reversing step S12, the sewing operation is continued The control action is the "second control mode" in the present invention.

Figure 13(a) shows that after the initial sewing is performed according to one sewing data, the presser foot lifting mechanism is not activated, but the next sewing is performed according to other sewing data and the sewing operation is completed. Graphical data (A) of the control action. In addition, shown in FIG. 13( b ) is graphic data (B) for realizing the control operation of performing sewing based on one sewing data and ending the sewing operation.

Using the pattern data (A) shown in Fig. 13(a), it is possible to carry out the X-reinforcement work without leaving a thread, or to nail a 4-hole button on the fabric. When the pattern data (A) is realized, it will go through the sewing data reading step S4 shown in Fig. The motor reverses step S12 to continuously perform the sewing operation (implementation of the second control mode). Subsequently, through the sewing data read-in step S4, thread cutting and rewinding step S5, data address updating step S8, presser foot lifting step S9 and end the sewing operation (realization of the first control mode). In this case, the first control mode can be realized by driving the pulse motor 80 in a state in which the rotation direction is reversed.

On the other hand, normal reinforcement work can be realized by the graphic data (B) shown in FIG. 13(b). When realizing the graphic data (B) shown in Fig. 13(b), it will go through the sewing data reading step S4 shown in Fig. 12, the thread trimming and rewinding step S5, the data address updating step S8 and the presser foot lifting step S9 And end the sewing operation (realization of the first control mode).

FIG. 14 schematically shows the movement amount of the thread cutting link 11 and the movement amount of the presser lifter link 31 when the cam member 60 makes one rotation (0° to 360°). In Fig. 14, "Cam starting point" corresponds to state I in Fig. 9(a), "tangent starting point" corresponds to state II in Fig. 9(b), and "tangential front point" corresponds to Fig. 9(c) State III, "tangent end point" corresponds to State IV in Fig. 10(a). In addition, the "slider start point" corresponds to the state V of FIG. 10(b), and the "presser foot uppermost point" corresponds to the state VI of FIG. 10(c).

<Example A> in Figure 14 is a schematic representation of the control action when performing X-reinforcement operations without remaining connections, or nailing 4-hole buttons on fabrics, which can be used as shown in Figure 13(a) Graph data (A) implementation. In this <Example A>, first, the sewing data reading step S4, the thread cutting/rewinding step S5, the data address updating step S8, and the pulse motor stopping step S10 shown in FIG. 12 are performed. At the time when the pulse motor stop step S10 ends, the cam member 60 is in a state corresponding to the "end point of the sliding piece" in FIG. 13 .

The state corresponding to the "end point of the sliding piece" means a state in which the state V of FIG. 10 (b) is slightly rotated clockwise. In addition, the presser foot 71 of the cloth presser 70 is in a state of not rising. The reason why this state is possible by providing a gap between the lower end 36a of the presser driving foot 36 of the presser lifting mechanism 30 and the contact pin 73c of the cloth presser 70 is as described above.

Next, the mark reversing step S11 and the pulse motor reversing step S12 are performed to reverse the pulse motor 80 from this "slider end point". When the pulse motor reversing step S12 is completed, the cam member 60 is in a state corresponding to the "slide start point" in FIG. 14 (state V in FIG. 10( b )).

Then, by the reverse pulse motor 80, the sewing operation is completed through the sewing data reading step S4, the thread cutting and rewinding step S5, the data address updating step S8 and the presser foot lifting step S9. When the presser foot lifting step S9 is completed, the cam member 60 is in a state corresponding to the "presser foot uppermost point" in FIG. 14 (state VI in FIG. 10( c )).

<Example B> in Fig. 14 is a schematic representation of the control action during normal reinforcement work, which can be realized with graphic data (B) as shown in Fig. 13(b). In this <Example B>, the sewing operation ends after the sewing data read-in step S4, the thread cutting and rewinding step S5, the data address updating step S8 and the presser foot lifting step S9. When the presser foot raising step S9 is finished, the cam member 60 is in a state corresponding to the "highest presser foot point" in FIG. 14 (state VI in FIG. 10( c )).

In the backtacking sewing machine of this embodiment, since one drive motor (pulse motor 80) can be used to stagger and continuously perform the three actions of mechanical thread trimming, thread rewinding, and presser foot lifting, it is not necessary to The driving mechanism for driving the thread cutting mechanism 10 (and the presser foot lifting mechanism 30 ) and the mechanism for driving the thread threading mechanism 50 are respectively arranged and controlled separately. Therefore, the thread cutting mechanism 10, the presser foot lifting mechanism 30, and the thread wiping mechanism 50 can always be operated at a fixed timing.

In particular, in this embodiment, since there is a gap between the lower end 36a of the presser foot driving foot 36 of the presser foot lifting mechanism 30 and the abutment pin 73c of the presser foot device 70, it is possible not to simultaneously perform the thread rewinding action and Presser foot lifting action, and can always maintain a stable delay time from the end of the rewinding action to the start of the presser foot lifting action.

In addition, since the driving mechanism for driving the thread cutting mechanism 10, the presser foot lifting mechanism 30, and the thread threading mechanism 50 is one driving motor (pulse motor 80) on the backtack sewing machine of this embodiment, it is not necessary to separately install them as in the past. A driving mechanism that drives the thread cutting mechanism 10 and the presser foot lifting mechanism 30 , and a mechanism that drives the thread wiping mechanism 50 . Therefore, the sewing machine cost can be reduced.

In addition, because on the backtack sewing machine of this embodiment, the thread cutting cam portion X2 of the first cam 61, the thread rewinding cam portion and the presser foot lifting cam portion Y2 of the second cam 62 form the thread cutting mechanism 10 and the thread threading mechanism 50. And the action of the presser foot lifting mechanism 30 is a symmetrical shape that can perform the same action regardless of the rotation direction of the pulse motor 80, so no matter which direction the pulse motor 80 rotates, the same thread cutting action, thread rewinding action and pressing action can be performed. Foot lift action. Therefore, smooth sewing work can be realized.

In addition, since the backtacking sewing machine of this embodiment is equipped with a first control mode that can flexibly switch and realize the rotation direction of the pulse motor 80 to operate in the order of the thread cutting mechanism 10, the thread wiping mechanism 50, and the presser foot lifting mechanism 30 , and after the pulse motor 80 is rotated in the direction of rotation in which the thread cutting mechanism 10, the thread removal mechanism 50, and the presser foot lifting mechanism 30 are operated in sequence, the pulse motor 80 is rotated in the opposite direction before the presser foot lifting mechanism 30 is operated. The rotation position of the pulse motor 80 is located in the second control mode of the control mechanism CPU90 in the non-operating area, so reliable sewing operations corresponding to various situations can be performed.

Therefore, for example, when it is desired to fasten a 4-hole button to the cloth (refer to Fig. 14 <Example A>), without moving the presser foot 71 of the cloth presser 70 upward, the cloth is kept intact. During sewing operation, at first, by realizing the 2nd control mode with CPU90, after forming initial seam trace, make thread cutting mechanism 10 and thread threading mechanism 50 action and suppress the action of presser foot lifting mechanism 30, then, by realizing the 2nd control pattern by CPU90 1 control mode, the next stitch can be formed. Therefore, since the presser foot 71 of the cloth presser device 70 moves upward due to the operation of the presser foot lifting mechanism 30, there will be no discomfort such as fabric deviation, so high efficiency of the sewing operation can be realized.

In addition, when it is not desired to form a connecting line connected between the first stitch and the next stitch for the sake of appearance, first, by realizing the second control mode by the CPU 90, only the thread cutting mechanism is activated after the first stitch is formed. And thread thread mechanism action, and suppress the action of presser foot lifting mechanism 30, then, can form the next stitch by realizing the 1st control mode by CPU90. Therefore, since the connecting line between the first stitch and the next stitch is not formed, the quality of the sewn product can be improved.

In addition, of course, this invention is not limited to the said Example, It goes without saying that it can change suitably. For example, when the presser foot lifting mechanism 30 is not operated (the second control mode) following the operation of the thread-swiping mechanism 50, the rotation position of the pulse motor 80 when the thread-swiping mechanism 50 is driven is controlled by the CPU 90, and the sliding plate 58 can be adjusted to The swing range is changed to a range smaller than the range limited by the stopper pin 54 .

That is, as mentioned above, the stopper pin 54 is a component that restricts the sliding piece 58 from swinging more than necessary with the action of the presser foot lifting mechanism 30, but does not make the presser foot lifting mechanism sway when the action of the thread threading mechanism 50 continues. In the second control mode of the 30 action, the movement amount of the presser foot lifting drive link 32 can be controlled by the control of the CPU 90, so that the swing of the sliding piece 58 stops before being restricted by the limit pin 54, and the sliding piece can be changed. 58 movable areas. In addition, the movable area at this time can be set using the operation panel 93 . That is, the CPU 90 has a function of a movable region changing mechanism for changing the movable region of the sliding piece 58 of the wire threading mechanism 50 .

With the CPU 90 provided with such a movable region changing mechanism, the movable region of the slide piece 58 can be appropriately set according to the thickness of the material to be sewn or the thickness of the thread used for sewing. Therefore, unnecessary swinging of the slide sheet 58 can be suppressed, and the time required for the swinging of the slide sheet 58 can be shortened, thereby improving sewing efficiency.

(invention effect)

According to the above-mentioned invention, since one drive motor can be used to stagger and continuously perform the three actions of mechanical thread trimming, thread rewinding, and presser foot lifting, it is not necessary to separately set up and control the driving thread trimming as in the past. The driving mechanism of the mechanism (and the presser foot lifting mechanism), and the mechanism of driving the threading mechanism. Therefore, it is possible to make the thread cutting mechanism, the thread threading mechanism and the presser foot lifting mechanism always operate at a fixed time. As a result, cycle delays can be prevented.

In addition, according to the first aspect of the present invention, since the driving mechanism for driving the thread trimming mechanism, the presser foot lifting mechanism and the thread wiping mechanism is a single drive motor, it is not necessary to separately provide the driving mechanism for driving the thread cutting mechanism (and the presser foot lifting mechanism), and the driving mechanism. The driving mechanism of the threading mechanism. Therefore, it is possible to reduce the cost, size and weight of the sewing machine.

In addition, reliable sewing operations corresponding to various situations can be performed.

For example, when it is desired to carry out the sewing operation without moving the presser foot of the cloth press device upward and keep the cloth intact as it is when nailing a 4-hole button on the cloth, first, realize the second step with the control mechanism. control mode, so as to form the stitches passing through the two buttonholes, and then make the thread trimming mechanism and the thread threading mechanism act and at the same time suppress the action of the presser foot lifting mechanism, and then use the control mechanism to realize the first control mode, so as to form threading Trace through the remaining two holes.

Therefore, since the presser foot of the cloth presser device moves upward due to the operation of the presser foot lifting mechanism, there will be no discomfort such as cloth deviation, so high efficiency of the sewing operation can be realized.

In addition, when it is not desired to form a connection line between the first stitch and the next stitch for the sake of appearance, first, the second control mode is realized by the control mechanism, and after forming the first stitch, only By operating the thread trimming mechanism and the thread wiping mechanism, and suppressing the operation of the presser lifting mechanism, the next stitch can be formed by realizing the first control mode by the control mechanism. Therefore, since the connecting line between the first stitch and the next stitch is not formed, the quality of the sewn product can be improved.

Furthermore, unnecessary swinging of the sliding sheet can be suppressed, and the time required for swinging of the sliding sheet can be shortened, thereby improving sewing efficiency.

Claims (7)

1. A sewing machine having: a thread cutting mechanism provided with a movable blade for cutting off a thread connected to a machine needle under a sewn object; The lifting mechanism, the thread-rewinding mechanism that crosses and moves on the suture path between the machine needle and the sewing object and has the thread rewinding piece that pulls the suture cut by the thread cutting mechanism on the sewing object, is characterized in that it has: single drive motor, and a first cam that is rotatable in conjunction with the drive motor and includes a thread cutting cam portion that operates the thread cutting mechanism by changing the rotational phase; and The thread reeling cam unit is rotatable in conjunction with the drive motor, and includes a thread reeling cam portion that operates the thread winding mechanism by a change in a rotational phase having a predetermined phase difference with respect to the first cam, and a cam portion that operates by the rotational phase The second cam of the presser foot lift cam section that makes the presser foot lift mechanism actuate, and a first connecting member configured to connect the thread cutting cam portion of the first cam to the thread cutting mechanism, and a second connecting member configured to connect the thread reversing cam portion and the presser foot lifting cam portion of the second cam with the thread threading mechanism and the presser foot lifting mechanism; The predetermined phase difference between the first cam and the second cam is formed so that after the thread trimming mechanism completes the thread trimming operation by the rotation of the drive motor, the thread trimming mechanism and the presser foot Lift the structure of the mechanism action. 2. The sewing machine according to claim 1, characterized in that: The drive motor can rotate forward and reverse, The thread cutting cam portion of the first cam, the thread rewinding cam portion of the second cam, and the presser lifting cam portion are formed as the thread cutting mechanism, the thread slendering mechanism, and the presser. The movement of the foot lift mechanism is independent of the rotation direction of the drive motor, the same respectively symmetrical shape. 3. The sewing machine according to claim 2, characterized in that: the first cam and the second cam, a non-operating area configured to clamp any of the thread cutting mechanism, the thread slitting mechanism, and the presser foot lifting mechanism in which none of the mechanisms operates, It also has a control mechanism that can be flexibly switched to realize the first control mode of rotating the drive motor in the rotation direction that makes the thread cutting mechanism, the thread threading mechanism, and the presser foot lifting mechanism operate in this order. , and after turning the drive motor in the rotation direction for operating the thread cutting mechanism and the thread slitting mechanism in this order, and turning the drive motor in the reverse direction before operating the presser foot lifting mechanism, and A second control mode in which the rotational position of the drive motor is set within the non-operating region. 4. The sewing machine according to claim 3, characterized in that: A movable range changing mechanism is provided for changing a movable range of the thread reeling blade of the thread-swiping mechanism when the thread-swiping mechanism is in operation in the second control mode. 5. The sewing machine according to claim 1 or 2, characterized in that: The first cam and the second cam are arranged at intervals along the axial direction and fixed on the output shaft of the drive motor. 6. The sewing machine according to claim 5, characterized in that: The first cam and the second cam are integrally provided on a cam member fixed to the output shaft of the drive motor. 7. The sewing machine according to claim 1 or 2, characterized in that: The second cam forms the thread rewinding cam portion and the presser foot lifting cam portion according to the rotation direction.

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