CN105862276B - Sewing machine - Google Patents

Abstract

The invention provides a sewing machine, which shortens the sewing starting end of the lower thread of the sewed object. In a sewing machine (10) having a needle hole (15) formed in a needle plate (17) or a feed dog (14), the sewing machine (10) is provided with: a lower thread inserting mechanism (2) which inserts the sewing starting end part of the lower thread (D) into the needle hole from the lower side by using air; a sewing starting end holding mechanism (50) which holds the sewing starting end of the lower thread passing through the needle hole on the upper side of the needle plate; a first thread cutting device (60) for cutting the sewing starting end of the lower thread held by the sewing starting end holding mechanism; and a control device (110) for controlling the operation of the sewing machine, wherein the sewing starting end holding mechanism (50) holds the lower thread which passes through the needle hole by the lower thread inserting mechanism (2), and the first thread cutting device (60) cuts the lower thread, thereby shortening the sewing starting end of the lower thread.

Description

Sewing machine

Technical Field

The present invention relates to a sewing machine with a thread cutting device.

Background

The conventional sewing machine is provided with a needle thread catching mechanism which catches the sewing starting end part of the needle thread from a needle for dropping the needle of a first needle by using a catching component at the lower side of a needle plate and releases the sewing starting end part of the needle thread after dropping the needle of a plurality of needles, thereby preventing the sewing starting end part of the needle thread from being pulled out from the needle dropping position of the first needle due to lifting of a balance and causing poor sewing.

The catching member of the catching mechanism has opposite surfaces which can contact and separate from each other, needle fall of the sewing needle is performed between the opposite surfaces, and when the sewing starting end part of the top thread is pulled out downwards by the tip of the kettle, the opposite surfaces are closed to catch the sewing starting end part of the top thread.

However, if the sewing start end of the needle thread is caught in the above manner, the sewing start end of the needle thread hangs down long from the needle drop position of the first needle on the back surface of the cloth.

Therefore, in the conventional needle thread catching mechanism, the holding force of the opposite surface of the catching member after the needle drop of the first needle is reduced as compared with the normal state, and the holding force is adjusted so that the sewing start end portion of the needle thread is slid to a degree that the sewing start end portion is not pulled out from the whole catching member by lifting the balance, and the catching length is shortened (for example, refer to patent document 1).

Patent document 1: japanese patent laid-open No. 2006-320365

However, in the conventional sewing machine, although the sewing start end portion of the upper thread is considered to be shortened, the sewing start end portion remains with respect to the lower thread, and the lower thread hangs down from the object to be sewn to be long, which results in a reduction in sewing quality. In addition, in order to improve the sewing quality, the sewing starting end portion of the lower thread must be cut by a manual operation after sewing, which increases the work load.

Disclosure of Invention

The invention aims to shorten the sewing starting end of a lower thread left at a sewed object.

The invention described in claim 1 is characterized in that,

a sewing machine, which is provided with a needle hole formed at a needle plate or a feed gear,

the sewing machine is characterized by comprising:

a lower thread inserting mechanism having an air blowing mechanism for inserting a sewing start end portion of the lower thread into the needle hole from a lower side by air;

a sewing start end holding mechanism for holding a sewing start end of the lower thread passing through the needle hole on an upper side of the needle plate;

a first thread cutting device for cutting the sewing starting end of the lower thread held by the sewing starting end holding mechanism; and

and a control device for controlling the operation of the sewing machine.

The invention described in claim 2 is characterized in that, in the sewing machine described in claim 1,

the air blowing mechanism is provided with a nozzle for blowing air toward the needle hole, and the nozzle is provided with a slit part for allowing the sewing starting end part of the lower thread to pass through at the front end part.

The invention described in claim 3 is characterized in that, in the sewing machine described in claim 1 or 2,

the sewing starting end holding mechanism comprises a sliding plate, an upper thread catching hole and a lower thread catching hole are formed in the sliding plate in an aligned manner along the sliding direction, the sewing starting end of the lower thread and the sewing starting end of the upper thread can be clamped and held between the opposite surface of the needle plate and the sliding plate,

the sliding plate is movable to an upper thread insertion position where the upper thread catching hole and the needle hole coincide, a lower thread insertion position where the lower thread catching hole and the needle hole coincide, and a retreat position where both the lower thread catching hole and the upper thread catching hole are separated from the needle hole.

The invention described in claim 4 is characterized in that, in the sewing machine described in claim 3,

the slide plate is arranged at the retreating position, and clamps and keeps the sewing starting end part of the upper thread and the sewing starting end part of the lower thread between the opposite surface of the needle plate and the slide plate,

the control device controls the sewing machine in such a manner that the sliding plate is positioned at the lower thread insertion position before the needle of the first needle is dropped, the sliding plate is positioned at the upper thread insertion position after the sewing start end portion of the lower thread is inserted into the needle hole and the lower thread catching hole from the lower side by the blowing mechanism, the sliding plate is positioned at the retreat position after the sewing start end portion of the upper thread is inserted into the needle hole and the upper thread catching hole by the needle dropping of the first needle, and the sewing start end portion of the upper thread and the sewing start end portion of the lower thread are cut by the first thread cutting device after the needle dropping of the second needle and the needle dropping of the second needle.

The invention described in claim 5 is characterized in that, in the sewing machine described in claim 3 or 4,

the cutter of the first thread cutting device is arranged below the sliding plate,

the sewing machine is provided with a thread pulling mechanism which moves downwards when the sliding plate is at the retreating position, pulls the sewing starting end part of the upper thread and the sewing starting end part of the lower thread pulled by the sliding plate and enables the sewing starting end parts to be clamped with the first thread cutting device,

the control device controls the sewing machine in such a manner that the first thread cutting device cuts the sewing starting end portion of the upper thread and the sewing starting end portion of the lower thread after the thread pulling mechanism is moved downward.

The invention described in claim 6 is characterized in that, in the sewing machine described in any one of claims 3 to 5,

a second thread cutting device for cutting the lower thread after sewing and holding the end part of the cut lower thread on the side of the kettle as the sewing starting end part of the next sewing,

the inserting mechanism of inserting lower line has:

a holding releasing mechanism for releasing the holding state of the sewing starting end of the lower thread by the second thread cutting device; and

and a thread collecting mechanism for collecting the sewing starting end of the lower thread below the needle hole.

The invention described in claim 7 is characterized in that, in the sewing machine described in claim 6,

the thread collecting mechanism is provided with a thread collecting component which collects the sewing starting end part of the lower thread at the lower side of the needle hole through forward movement,

the wire collecting member includes: a first inclined portion formed at a front end portion to move a sewing start end portion of the lower thread upward; a recessed portion formed at an upper portion of the distal end portion and configured to catch a sewing start end portion of the lower thread; and a second inclined part formed inside the concave part to make the sewing starting end part of the lower thread move downwards,

an upper end portion of the second inclined portion is formed higher than an upper end portion of the first inclined portion.

The invention described in claim 8 is characterized in that, in the sewing machine described in claim 6 or 7,

the control device controls the sewing machine in such a manner that the thread collecting mechanism is driven to collect the sewing starting end portion of the lower thread on the lower side of the needle hole before the sewing starting end portion of the lower thread is inserted into the needle hole and the lower thread catching hole from the lower side by the blowing mechanism, and the holding releasing mechanism is driven to release the holding state of the sewing starting end portion of the lower thread by the second thread cutting device.

ADVANTAGEOUS EFFECTS OF INVENTION

The invention provides a sewing machine, which uses a lower thread inserting mechanism to blow up the sewing starting end of a lower thread from the lower side and insert the sewing starting end into a needle hole, the sewing starting end holding mechanism holds the sewing starting end of the lower thread on the upper side of a needle plate, and a first thread cutting device cuts the sewing starting end of the held lower thread, therefore, the sewing starting end of the lower thread can be cut from a sewed object without depending on manual operation, the sewing starting end of the lower thread remained at the sewed object can be shortened, and the sewing quality can be improved. Further, since no manual operation is required, the burden of the cutting operation of the sewing start end portion of the lower thread can be eliminated.

Drawings

FIG. 1 is a side view showing a structure of a periphery of a needle of an integrated feed sewing machine.

Fig. 2 is a plan view of an end portion of the base portion of the sewing machine opposite to the longitudinal machine body portion side.

Fig. 3 is a block diagram showing a control system of the sewing machine.

FIG. 4 is a side view showing the structure of the periphery of a horizontal tank.

Fig. 5 is an oblique view of the wire-concentration mechanism.

Fig. 6 is a top view of the wire-concentration mechanism.

Fig. 7(a) is an enlarged plan view showing the position before and after the operation of the line concentration hook when the lower line is at the low position, and fig. 7(B) is an enlarged plan view showing the position before and after the operation of the line concentration hook when the lower line is at the high position.

FIG. 8 is a perspective view showing a state where a nozzle of an air blowing mechanism is retracted and a structure around a horizontal tank.

FIG. 9 is a perspective view showing the state of entry of the nozzle of the blowing mechanism and the structure of the periphery of the horizontal tank.

Fig. 10 is an oblique view of a flat nozzle.

Fig. 11 is a sectional view of a flat nozzle.

Fig. 12 is an oblique view of a circular nozzle.

FIG. 13 is a cross-sectional view of a circular nozzle.

Fig. 14 is a plan view of the needle board.

FIG. 15 is a perspective view of the periphery of a needle plate showing the cutting operation of the sewing starting end of the lower thread and the upper thread.

Fig. 16 is a perspective view of the periphery of the needle plate showing the cutting operation of the sewing start end of the lower thread and the upper thread after fig. 15.

Fig. 17 is a perspective view of the periphery of the needle plate showing the cutting operation of the sewing start end of the lower thread and the upper thread after fig. 16.

Fig. 18 is a perspective view of the periphery of the needle plate showing the cutting operation of the sewing start end of the lower thread and the upper thread after fig. 17.

Fig. 19 is a perspective view of the periphery of the needle plate showing the cutting operation of the sewing start end of the lower thread and the upper thread after fig. 18.

Fig. 20 is a perspective view of the periphery of the needle plate showing the cutting operation of the sewing start end of the lower thread and the upper thread after fig. 19.

Fig. 21 is an oblique view of the first wire cutting device.

Fig. 22 is a perspective view showing the cutting operation of the movable knife and the fixed knife in the first cutting device.

Fig. 23 is a perspective view showing the cutting operation of the movable cutter and the fixed cutter of the first cutting device shown in fig. 22 and thereafter.

Fig. 24 is a perspective view showing the cutting operation of the movable knife and the fixed knife in the first cutting device after fig. 23.

Fig. 25 is a side view showing the cutting operation of the movable cutter and the fixed cutter of the first cutting device.

Fig. 26(a) is an explanatory operation diagram showing a cutting operation of the sewing start end portion of the lower thread and the upper thread, fig. 26(B) is an explanatory operation diagram following fig. 26(a), and fig. 26(C) is an explanatory operation diagram following fig. 26 (B).

Fig. 27(a) is an explanatory view showing an operation of cutting the sewing start end portion of the lower thread and the upper thread after fig. 26(C), fig. 27(B) is an explanatory view of the operation after fig. 27(a), and fig. 27(C) is an explanatory view of the operation after fig. 27 (B).

Fig. 28(a) is an explanatory view showing the operation of cutting the sewing start end portion of the lower thread and the upper thread after fig. 27(C), fig. 28(B) is an explanatory view of the operation after fig. 28(a), and fig. 28(C) is an explanatory view of the operation after fig. 28 (B).

Fig. 29 is an explanatory view showing the operation of cutting the sewing start end portions of the lower thread and the upper thread after fig. 28 (C).

FIG. 30 is a flowchart showing the control of the cutting operation of the sewing starting end portion of the lower thread and the upper thread.

Fig. 31 is an oblique view of another example of the wire pulling mechanism.

Fig. 32 is a plan view of another example of the sewing starting end holding mechanism.

Fig. 33 is a perspective view of another example of the sewing starting end holding mechanism.

Fig. 34 is a perspective view showing a restricting plate of the wire pulling member.

Description of the reference numerals

10 Sewing machine

11 stitch

14 feed tooth

15 pinhole

17 needle plate

18 horizontal kettle

19 catching mechanism

2 inserting mechanism for inserting lower line

20 holding release mechanism

30 line concentration mechanism

31 line concentration hook (line concentration component)

40 air blowing mechanism

41 spray nozzle

411 slit part

42 nozzle

421 slit part

50. 50A start end holding mechanism

51. 51A sliding plate

511 first opening part (Upper line catching hole)

512 second opening (lower line trap hole)

60 first tangent device

61 Movable cutting knife

62 fixed cutter

621 hook part

70 second thread cutting device

71 Movable knife

72 fixed cutter

73 plate spring

80. 80A wire pulling mechanism

81 stay wire component

81A first wire drawing member

83A second wire drawing member

85A, 86A limiting plate

110 control device

117 sewing machine motor

C cloth (quilt sewing)

Detailed Description

[ outline of Sewing machine ]

The sewing machine 10 of the present invention will be described below with reference to the drawings. The sewing machine 10 is a so-called integrated feed sewing machine, and as shown in fig. 1, includes: a needle bar and a sewing needle 11 which move up and down and swing in a cloth conveying direction (see fig. 18); a transport leg 12 that moves up and down and swings back and forth in synchronization with the needle bar; a presser foot part 13 which moves up and down alternately with the conveying foot part 12; and a feed tooth 14 which is periodically moved in the conveying direction in synchronization with the needle bar.

That is, the integrated feed sewing machine has a through hole 12a into which the needle 11 is inserted formed in the feed leg 12, and a needle hole 15 into which the needle 11 is inserted is formed in the feed tooth 14.

When the sewing needle 11 and the feed leg 12 are lowered, the feed teeth 14 are raised, and all of them move forward in the cloth feed direction. Thereby, the cloth is nipped by the feed leg 12 and the feed tooth 14, and is passed through by the sewing needle 11 and fed to the front side in the cloth feeding direction.

Further, while the presser foot part 13 is lowered when the presser needle 11 and the transport foot part 12 are raised and the cloth is pressed from above by the presser foot part 13, the presser needle 11 and the transport foot part 12 are retreated and needle dropping is performed while the material to be sewn is transported again.

In the case of the integrated feed sewing machine, the needle hole 15 is formed in the feed dog 14 which performs the circular motion, and the position of the needle hole 15 is varied together with the circular motion of the feed dog 14, but in the following description, as a description of a relative positional relationship with the needle hole 15, the position of the needle hole 15 in the case where the feed dog 14 is at the upper axis angle of 0 ° (needle bar top dead center) is assumed unless otherwise specified.

The sewing machine 10 includes all the structures that are generally provided as a general feed sewing machine, such as a needle bar vertical movement mechanism, a cloth feed mechanism, a pot drive mechanism, a thread adjuster, a balance, and the like, but these are well known structures, and therefore, detailed description thereof is omitted.

In the following description, in a state where the sewing machine 10 is placed on a horizontal plane, the vertical upper side is "upper", the vertical lower side is "lower", the downstream side in the cloth conveying direction is "front", the upstream side in the cloth conveying direction (operator side) is "rear", the left-hand side is "left" in a state facing forward, and the right-hand side is "right" in a state facing forward.

Fig. 2 is a plan view of an end portion of the base portion 16 of the sewing machine 10 opposite to the longitudinal machine body portion side (left side), and the upper cover and a part of the internal structure are omitted. Fig. 3 is a block diagram showing the overall structure of the sewing machine.

As shown in the figure, the sewing machine 10 includes: a needle plate 17 provided above the sewing machine base part 16; a horizontal kettle 18 provided on the lower right side of the needle plate 17; a lower thread inserting mechanism 2 for inserting the sewing starting end of the lower thread into the needle hole 15 from the lower side; a sewing starting end holding mechanism 50 for holding the sewing starting end of the lower thread and the upper thread passing through the needle hole 15 on the upper side of the needle plate 17; a first thread cutting device 60 for cutting the sewing starting end of the lower thread held by the sewing starting end holding mechanism 50; a second thread cutting device 70 for cutting the lower thread after sewing and holding the end of the cut lower thread on the side of the kettle as the sewing starting end of the next sewing; a thread pulling mechanism 80 for pulling downward the sewing starting end portions of the upper thread and the lower thread pulled out in the sliding direction by the sliding plate 51 of the sewing starting end portion holding mechanism 50; a collecting mechanism 19 for collecting the cut pieces of the lower line and the upper line cut by the first cutting line device 60; and a control device 110 that controls each configuration of the sewing machine 10.

The lower wire insertion mechanism 2 has a structure including: a holding releasing mechanism 20 for releasing the holding state of the sewing starting end of the lower thread by the second thread cutting device 70; a thread collecting mechanism 30 for collecting the thread at the sewing starting end of the lower thread below the needle hole 15; and an air blowing mechanism 40 for inserting the sewing starting end of the lower thread into the pinhole 15 by using air after the holding state is released.

As described above, the sewing machine 10 includes the following mechanisms: a needle up-and-down moving mechanism for giving up-and-down movement and forward and backward swing to the needle bar and the sewing needle 11; a presser foot vertical moving mechanism which makes the conveying foot part 12 and the presser foot part 13 move up and down alternately; a cloth conveying mechanism which enables the feed teeth 14 to enter and exit from the opening of the needle plate 17 and conveys the cloth along the front and back directions; and a pot mechanism for rotationally driving the horizontal pot 18 at a speed twice as fast as the vertical movement of the sewing needle 11, and these mechanisms all use a sewing machine motor as a common driving source.

The above-described respective configurations will be explained in order below.

[ second line cutting device ]

FIG. 4 is a side view showing the structure of the periphery of the horizontal kettle 18, and FIG. 8 is a perspective view. As shown in fig. 2 to 4 and 8, the second thread cutting device 70 is disposed at a lower position than the needle plate 17 and in front of the needle hole 15. The second thread cutting device 70 includes: a hook-shaped movable cutter 71; a fixed cutter 72 fixed to the sewing machine frame; and a plate spring 73 that presses the movable knife 71 to the fixed knife 72 side.

The second thread cutting device 70 catches and cuts the upper thread and the lower thread that have passed from the needle hole 15 to the horizontal kettle 18 after the needle drop of the last needle, and holds the end of the cut lower thread. The lower thread end portion becomes a sewing start end portion at the next sewing.

The movable knife 71 is long in the front-rear direction and is connected to the second tangent solenoid 74 via a link in a state where the front end portion thereof is directed rearward, and performs a reciprocating operation of traveling rearward by the second tangent solenoid 74, catching the upper line and the lower line, and returning forward to the lower position.

Therefore, the distal end portion of the movable cutter 71 has a sharp shape, a hook-shaped return portion is formed near the distal end portion, and a cutting edge with a cutting edge directed forward is formed inside the return portion.

The fixed knife 72 is disposed above the movable knife 71, and the lower surface thereof is in sliding contact with the upper surface of the movable knife 71. The fixed cutter 72 is in the form of a cantilever beam extending rearward, and a cutting edge having a cutting edge directed rearward is formed at a distal end portion thereof. Thereby, the upper thread and the lower thread captured by the return portion of the movable knife 71 in the reciprocating forward path are sandwiched and cut by the cutting edge of the movable knife 71 and the cutting edge of the fixed knife 72 in the reciprocating return path.

Since the plate spring 73 is pressed upward from the lower side of the movable knife 71, the movable knife 71 can be pressed against the fixed knife 72, and a gap can be prevented from being generated between them, thereby enabling more reliable cutting.

Further, the plate spring 73 can hold the end portion of the cut lower thread on the side of the pot (the sewing start end portion of the next sewing) between the movable knife 71 and the plate spring 73, and the position of the sewing start end portion of the lower thread can be specified.

[ line concentration mechanism ]

The wire-collecting mechanism 30 has the following functions: guiding the sewing starting end portion of the lower thread to a proper position by the blowing mechanism 40 so that the sewing starting end portion of the lower thread can be inserted upward through the needle hole 15; and drawing the appropriate length of lower line from the spool inside the horizontal kettle 18.

Fig. 5 is a perspective view of the wire collecting mechanism 30, fig. 6 is an enlarged plan view showing a position before and after an operation of a wire collecting hook 31 described later, and fig. 7 is an explanatory view showing an operation of a lower wire at a tip end portion of the wire collecting hook 31. As shown in fig. 2 and 5, the thread collecting mechanism 30 is disposed at a position lower than the needle plate 17, and is disposed behind and slightly to the left of the needle holes 15.

The yarn collecting mechanism 30 includes: a thread collecting hook 31 as a thread collecting member for catching a sewing start end portion of a lower thread passing from the horizontal kettle 18 to the second thread cutting device 70 by a forward and backward movement; a first thread take-up cylinder 32 for moving the thread take-up hook 31 forward and backward; a support plate 33 that supports the entire wire-collecting mechanism 30; a support member 34 that can slide the first wire-collecting cylinder 32 in a predetermined direction with respect to the support plate 33; and a second thread take-up cylinder 35 that reciprocates the first thread take-up cylinder 32 in the predetermined direction with respect to the support plate 33.

The support plate 33 is attached to be horizontal to the sewing machine base 16, and has a long hole 331 for guiding the advancing/retreating movement direction of the first thread take-up cylinder 32. The long hole 331 is formed in the diagonally right forward direction, and if the first thread-collecting cylinder 32 is pushed out by the second thread-collecting cylinder 35, it moves forward and moves in a direction approaching the right.

The support member 34 is composed of a holding plate that holds the first thread collecting cylinder 32 on the back surface side of the support plate 33 so as not to come off, and a slide body, not shown, that slides in the long hole 331 and is coupled to the support plate 33 so as to be able to move forward and backward by the first thread collecting cylinder 32.

The first thread take-up cylinder 32 supported by the support plate 33 is held in a state where the advancing and retreating direction of the plunger coincides with the longitudinal direction of the thread take-up hook 31, and the advancing and retreating direction of the plunger is along the right oblique front side having a smaller right component than the long hole 331.

The wire-collecting hook 31 is moved diagonally forward to the right in two stages from the retreat position by the first and second wire-collecting cylinders 32, 35.

The line collecting hook 31 and the lower line shown by the solid line in fig. 6 show the positions in the state where both the first and second line collecting cylinders 32, 35 are driven forward, and the line collecting hook 31 and the lower line shown by the two-dot chain line show the positions in the state where only the second line collecting cylinder 35 is retracted from the state where both the line collecting cylinders 32, 35 are driven forward.

The line-collecting hook 31 is advanced the farthest so that its leading end portion reaches a position crossing the lower line crossing from the horizontal kettle 18 to the second line-cutting device 70.

Further, by retracting only the second thread collecting cylinder 35 from the state where both the first and second thread collecting cylinders 32 and 35 are advanced, the lower thread which has passed from the horizontal kettle 18 to the second thread cutting device 70 can be collected on the path which passes between the tip end of the nozzle 41 of the air blowing mechanism 40 and the needle hole 15.

As shown in fig. 7, the tip end portion of the wire collecting hook 31 includes: a first inclined portion 311 formed at the front end portion to move the sewing start end portion of the lower thread upward; a recess 312 formed at an upper portion of the front end portion to catch a sewing start end portion of the lower thread; a second inclined portion 313 formed on a rear end portion side (opposite side to the front end portion side) inside the concave portion 312 to move a sewing start end portion of the lower thread downward; and a third inclined portion 314 facing the second inclined portion 313 in the concave portion 312, and an upper end portion of the second inclined portion 313 is formed higher than an upper end portion of the first inclined portion 311 in a front end portion of the thread trap 31.

The first inclined portion 311 is inclined in a direction ascending toward the rear as indicated by an inclination angle θ 1, and is inclined so as to push up the lower wire that abuts the first inclined portion 311 when the wire-collecting hook 31 advances.

The second inclined portion 313 is an obtuse angle as indicated by the inclination angle θ 2, and is inclined in a direction descending toward the rear, and an upper end portion of the second inclined portion 313 is formed higher than an upper end portion of the first inclined portion 311. Therefore, when the thread collecting hook 31 moves forward, the lower thread pushed up by the first inclined portion 311 can be lowered and guided into the concave portion 312.

The third inclined portion 314 is an obtuse angle as indicated by the inclination angle θ 3, and is inclined in a direction descending toward the rear, and the upper end portion thereof is at the same height as the first inclined portion 311. Therefore, when the thread-collecting hook 31 retreats, the lower thread guided into the recess 312 is caught, and the lower thread is prevented from being accidentally dropped from the recess 312.

According to these configurations, when the lower thread is at a position lower than the upper end portion of the first inclined portion 311, as shown in fig. 7(a), the advancing of the thread collecting hook 31 causes the lower thread to abut against the first inclined portion 311 and be pushed upward, and the lower thread is caught by the second inclined portion 313 and introduced into the concave portion 312. Further, if the line concentrating hook 31 is retreated, the lower line in the concave portion 312 is caught by the third inclined portion 314 and is held so as to be prevented from falling off from the concave portion 312. The lower line in the concave portion 312 is blown upward by a blowing mechanism described later, and moves along the third inclined portion 314 at this time, so that the movement is not hindered.

Further, when the lower wire is at a position higher than the upper end portion of the first inclined portion 311 and lower than the second inclined portion 313, the lower wire can be directly brought into contact with the second inclined portion 313 and introduced into the recess 312 by the advancement of the wire collecting hook 31 as shown in fig. 7 (B). The operation of the lower line when the wire collecting hook 31 retreats is the same as in the case of fig. 7 (a).

[ air blowing mechanism ]

Fig. 8 is a perspective view showing a retreated state of the nozzle 41 of the blowing mechanism 40, and fig. 9 is a perspective view showing an advanced state of the nozzle 41 of the blowing mechanism 40.

As shown in these figures, the air blowing mechanism 40 includes: a nozzle 41 that ejects air from a distal end portion toward the pinhole 15 from below the pinhole 15; a nozzle holding portion 43 that detachably holds the nozzle 41 and is connected to an air supply source (such as a compressor); a nozzle lift cylinder 44 for moving the nozzle 41 forward and backward via the nozzle holding portion 43; and a switching valve 45 that switches between supply and stop of air from the air supply source to the nozzle holding portion 43 (see fig. 3).

The nozzle holding portion 43 includes: a cylindrical nozzle insertion portion 431; and a frame portion 432 that connects the nozzle insertion portion 431 and the plunger of the nozzle lifting cylinder 44.

The nozzle insertion portion 431 can insert the nozzle 41, and the nozzle 41 can be fixed by a screw. Further, the nozzle 41 can be easily detached by screwing out the screw, and the flat nozzle 41 can be replaced with a circular nozzle 42 described later.

The nozzle holder 43 is connected to a hose for supplying air, and can eject air from the tip of the nozzle 41 by the supplied air.

The nozzle 41 held by the nozzle holding portion 43 is inclined forward. The plunger of the nozzle lift cylinder 44 can impart forward and backward movement to the nozzle 41 in the same direction as the longitudinal direction of the nozzle 41. As shown in fig. 9, the tip end of the nozzle 41 can be brought close to the position immediately below the pinhole 15 in the advanced state of the plunger of the nozzle elevation cylinder 44.

As shown in fig. 10 and 11, the nozzle 41 has a flat opening with a tip end portion extending substantially in the left-right direction, and can blow out compressed air at high speed. Further, a slit portion 411 is formed in the middle of the width direction of the tip end portion of the nozzle 41, and the sewing start end portion of the lower thread can be accommodated inside when the nozzle 41 moves in. That is, the air blowing mechanism 40 is disposed so that the lower thread start end portion of the thread gathered by the thread gathering hook 31 of the thread gathering mechanism 30 is just received in the slit portion 411 when the nozzle 41 enters.

The nozzle 41 may be replaced with a circular nozzle 42 shown in fig. 12 and 13. The circular nozzle 42 also has a slit 421 formed at its tip end to accommodate a lower line.

Since the opening of the circular nozzle 42 is wide, the air can be blown over a wide range.

[ holding releasing mechanism ]

As shown in fig. 4 and 8, the holding release mechanism 20 includes: a locking member 21 for locking the plate-like spring 73 of the second thread cutting device 70; and a release cylinder 22 for lifting the locking member 21.

The locking member 21 is disposed vertically and has its upper end bent at a right angle to the right. The bent portion 211 at the upper end of the locking member 21 is disposed so as to be close to and opposed to the upper surface of the middle portion of the plate spring 73 in the longitudinal direction from above.

The release cylinder 22 can be driven in a direction in which the locking member 21, which has the bent portion 211 at a position close to and facing the upper surface of the plate spring 73, is lowered, and the plate spring 73 can be pulled down via the locking member 21.

By this pulling down, the tip end portion of the plate spring 73 is separated from the movable knife 71, and the sewing start end portion of the lower thread held between the movable knife 71 and the plate spring is released.

[ needle plate ]

Fig. 14 is a plan view of the needle plate 17. The needle plate 17 is a rectangular flat plate horizontally attached to the upper surface of the sewing machine bed 16, and is disposed so that the longitudinal direction thereof is in the front-rear direction.

The needle plate 17 has a rectangular opening 171 in the center of the upper surface for inserting and removing the feed dog 14, and a notch 172 is formed in the opening 171, and the notch 172 is used for arranging the movable knife 61, the fixed knife 62, and the thread pulling member 81 of the first thread cutting device 60. They are formed vertically through the needle plate 17.

Further, a guide groove 173 of the slide plate 51 of the sewing starting end holding mechanism 50, which will be described later, is formed in front of the opening 171 so as to be continuous with the opening 171. The guide groove 173 has the same width as the opening 171.

[ Sewing starting end holding mechanism ]

The sewing starting end holding mechanism 50 includes: a slide plate 51 having a first opening 511 and a second opening 512 (see fig. 15 to 20) as an upper thread catching hole and a lower thread catching hole for holding the sewing start end portions of the upper thread and the lower thread, respectively; a first wire holding cylinder 52 for imparting a forward and backward movement to the slide plate 51; and a second wire holding cylinder 53 for applying a longitudinal movement to the slide plate 51 and the first wire holding cylinder 52 (see fig. 3).

The slide plate 51 is a long flat plate extending straight, and is disposed in the front-rear direction in the guide groove 173 of the needle plate 17. A first opening 511 for holding the sewing start end portion of the upper thread is formed through the rear end portion of the slide plate 51, and a second opening 512 for holding the sewing start end portion of the lower thread is formed through the rear end portion.

The slide plate 51 moves forward and backward, thereby positioning the first or second opening portions 511 and 512 directly above the needle hole 15, and moving the sewing start end portion of the lower thread D or the upper thread U forward after inserting the sewing start end portion, whereby the sewing start end portion of the lower thread D or the upper thread U is held by being sandwiched between the lower surface of the slide plate 51 and the inner surface of the guide groove 173 of the needle plate 17.

The slide plate 51 is first inserted with the sewing start end of the lower thread D blown up by the blowing mechanism 40 at the lower thread insertion position where the second opening 512 is positioned with respect to the needle hole 15 (fig. 16), and is moved forward from this state to become the upper thread insertion position where the first opening 511 is positioned with respect to the needle hole 15 (fig. 19). At the upper thread inserting position, the sewing start end portion of the lower thread D is sandwiched and held between the slide plate 51 and the needle plate 17, and the sewing start end portion of the upper thread U can be inserted. After the needle thread U is inserted, the slide plate 51 is further moved to the retracted position forward, and the lower thread D and the sewing start end portion of the needle thread U are held between the slide plate 51 and the needle plate 17 (fig. 20).

Therefore, the slide plate 51 needs to be moved and positioned among three positions, i.e., a lower thread insertion position, an upper thread insertion position, and a retracted position.

The plunger of the first thread holding cylinder 52 is directly connected to the slide plate 51, and moves the slide plate 51 from the lower thread insertion position to the upper thread insertion position.

And a second wire holding cylinder 53 having a plunger directly connected to the main body of the first wire holding cylinder 52, for moving the slide plate 51 and the first wire holding cylinder 52 from the upper thread insertion position to the retreat position.

Further, the first thread holding cylinder 52 may be supported by a sliding guide or the like movable in the front-rear direction in the sewing machine bed portion 16.

[ first tangent line device ]

Fig. 21 is a perspective view of the first wire cutting device 60, fig. 22 to 24 are perspective views of the movable cutter 61 and the fixed cutter 62 of the first wire cutting device 60, and fig. 25 is a rear view.

The first wire cutting device 60 includes: a movable knife 61 that is long in the left-right direction and has a blade edge facing rightward at the right end; a fixed cutter 62 that is long in the left-right direction and has a hook 621 at the right end; and a first thread cutting cylinder 63 for imparting reciprocating movement in the left-right direction to the movable cutter 61 (see fig. 3).

The tip of the movable cutter 61 is flat in the front-rear direction and is superimposed on the fixed cutter 62. Further, the base end portion of the movable cutter 61 is fixed to a support plate 64 by screw fastening, and the support plate 64 is attached to the plunger of the first thread cutting cylinder 63.

The movable knife 61 is positioned leftward of the slide plate 51 and the fixed knife 62 in the slit 172 of the needle plate 17 when not cutting, and moves rightward to enter the lower side of the slide plate 51 when cutting.

The fixed knife 62 has a blade edge facing leftward formed inside the hook 621 at the right end thereof, and the blade edge of the fixed knife 62 and the blade edge of the movable knife 61 are configured to cut the lower line and the upper line entering the inside of the hook 621.

The fixed knife 62 is disposed so as to extend rightward beyond the movable knife 61 at the time of non-cutting and to enter the lower side of the slide plate 51.

[ thread-pulling mechanism ]

As shown in fig. 22 to 25, the wire pulling mechanism 80 includes: a thread pulling member 81 which catches and pulls downward the lower thread D held by the slide plate 51 and the sewing start end portion of the upper thread U; and a wire pulling cylinder 82 for moving the wire pulling member 81 in a predetermined wire pulling direction (see fig. 3).

The wire member 81 includes: a holding portion 811 for pressing the sewing start end portions of the lower thread D and the upper thread U from above; a claw portion 812 that is bent downward at a front end portion (right end portion) of the holding portion 811 and holds the lower thread D and the sewing start end portion of the upper thread U so as not to fall off from the holding portion 811; and an extension portion 813 extending in the pull-out direction (obliquely left downward direction) from the holding portion 811, and a base end portion of the extension portion 813 is connected to the plunger of the pull-out cylinder 82.

The leading end of the wire member 81 is disposed adjacent to the front side of the fixed cutter 62 of the first wire cutting device 60. The wire member 81 is formed in a substantially U shape by the holding portion 811, the claw portion 812, and the projecting portion 813, and is disposed so that the sliding plate 51 passes through the inside thereof. Therefore, if the slide plate 51 moves to the forward retreat position and holds the sewing start end portions of the lower thread D and the upper thread U, the sewing start end portions of the lower thread D and the upper thread U pass through the U-shaped inner space.

At this time, as shown in fig. 22, the lower thread D and the upper thread U are positioned at the upper right with respect to the hook 621 of the fixed cutter 62, and thus cannot be cut in this state.

However, since the thread pulling member 81 is moved obliquely downward to the left by the thread pulling cylinder 82 as shown in fig. 25, the lower thread D and the sewing starting end portion of the upper thread U can be pulled into engagement with the inside of the hook 621 of the fixed cutter 62 as shown in fig. 23.

Accordingly, the lower thread D and the sewing start end portion of the upper thread U can be cut by moving the movable knife 61 in the left direction.

[ trapping mechanism ]

The catch mechanism 19 is disposed inside the sewing machine base portion 16 and below the first thread cutting device 60. The trap mechanism 19 includes: a frame body, the upper part of which is opened; a fan 191 provided inside the housing (see fig. 3); and a catcher for catching the cut pieces drawn to the lower line and the upper line in the frame, and the catcher can catch the cut pieces by driving the fan 191.

[ control System of Sewing machine ]

Based on fig. 3, a control system of the sewing machine is explained.

The control device 110 of the sewing machine 10 is roughly constituted by: a ROM 112 that stores and stores various programs for various processing such as control and judgment; a CPU 111 that performs various arithmetic processes according to these various programs; a RAM 113 used as a work memory in various processes; an EEPROM 114, which stores various sewing data and setting data.

The control device 110 is connected to the following components via a system bus, a drive circuit, and the like: a sewing machine motor 117 serving as a driving source of sewing, a release cylinder 22 of the holding release mechanism 20, a first thread collecting cylinder 32 and a second thread collecting cylinder 35 of the thread collecting mechanism 30, a nozzle lifting cylinder 44 and a switching valve 45 of the blowing mechanism 40, a first thread holding cylinder 52 and a second thread holding cylinder 53 of the start end holding mechanism 50, a first thread cutting cylinder 63 of the first thread cutting device 60, a second thread cutting solenoid 74 of the second thread cutting device 70, a thread pulling cylinder 82 of the thread pulling mechanism 80, a fan 191 of the catch mechanism 19, an operation input unit 115 for inputting various operations, a start pedal 116 for inputting start of sewing, and the like.

The control device 110 actually controls the solenoid valves that operate the release cylinder 22, the first wire-collecting cylinder 32, the second wire-collecting cylinder 35, the nozzle lift cylinder 44, the first wire holding cylinder 52, the second wire holding cylinder 53, the first wire cutting cylinder 63, the second wire cutting solenoid 74, and the wire pulling cylinder 82, but the solenoid valves are not shown here.

The sewing machine motor 117 and the fan 191 are controlled via a driver circuit, but the illustration thereof is omitted.

[ cutting control of the starting end of sewing ]

Fig. 30 is a flowchart of the cutting control of the sewing start end portion of the lower thread D and the upper thread U. The control of cutting the sewing start end portion of the lower thread D and the upper thread U at the start of sewing, which is performed by the control device 110 of the sewing machine 10 configured as described above, will be described mainly based on the oblique views of fig. 15 to 20, the operation explanatory diagrams of fig. 26 to 29, and the flowchart of fig. 30. In fig. 26 to 29, reference symbol C denotes a cloth as a material to be sewn.

In the cutting operation of the sewing start end portion to be described below, it is assumed that the sewing machine motor 117 is first stopped with the needle bar at the top dead center, and the front end portion of the lower thread is clamped by the second thread cutting device 70 by the sewing performed in the previous time. In addition, the sliding plate 51 is controlled to be at the retreat position (fig. 26(a)) in a state that the power of the sewing machine is OFF, and if the power of the sewing machine is ON, the sliding plate 51 is controlled to move to the lower thread insertion position (fig. 26 (B)). In the following description, the state in which the slide plate 51 is moved to the lower thread insertion position in the state in which the power source of the sewing machine is turned ON will be described.

The first and second wire holding cylinders 52 and 53 are set to the advanced state, and the slide plate 51 is positioned at the lower wire insertion position where the second opening 512 overlaps the needle hole 15 (step S1 in fig. 30). At this time, the wire pulling cylinder 82 is in the entered state, and the wire pulling member 81 is located on the upper side of the slide plate 51 (fig. 15).

As shown in fig. 4, the first and second thread collecting cylinders 32 and 35 of the thread collecting mechanism 30 are set to an entering state with respect to the sewing starting end portion of the lower thread passing from the horizontal kettle 18 to the second thread cutting device 70, and the thread collecting hook 31 is advanced. Thus, after the sewing start end of the lower thread is caught in the recess 312, only the second thread take-up cylinder 35 is set to the retreated state. Accordingly, the lower thread is drawn out from the horizontal kettle 18, and the sewing start end of the lower thread is drawn along the path passing directly below the needle hole 15.

Then, the nozzle lift cylinder 44 of the blower mechanism 40 is set to the on state, and the nozzle 41 is raised so that the tip end of the nozzle 41 approaches the lower line and the pinhole 15.

Then, the release cylinder 22 of the release mechanism 20 is set to the retreated state, and the locking member 21 is lowered, thereby releasing the holding state of the sewing start end portion of the lower thread by the second thread cutting device 70. Then, the switching valve 45 of the blower mechanism 40 is controlled to switch to the air supply state. As a result, the sewing start end of the lower thread D is blown up from below the needle hole 15 and inserted into the needle hole 15 and the second opening 512 (fig. 16, 26(B), and step S5 of fig. 30).

Then, the first thread holding cylinder 52 is set to the retreated state, and the slide plate 51 is moved to the upper thread insertion position where the first opening 511 overlaps the needle hole 15 (fig. 17, 26(C), and step S7 of fig. 30). Thereby, the sewing start end portion of the lower thread D is held between the slide plate 51 and the needle plate 17. At this time, the nozzle lift cylinder 44 is set to the retreated state. The nozzle 41 is lowered.

Then, the sewing machine motor 117 is driven to start sewing (step S9 in fig. 18 and 30).

As a result, the needle 11 is lowered to drop the first needle, the upper thread U enters the first opening 511 and the needle hole 15, and is caught by the tip of the horizontal kettle 18 that starts to rotate by the driving of the sewing machine motor 117, and the sewing start end portion of the upper thread U is pulled to the lower side of the needle hole 15 (fig. 19 and 27 a).

Then, the second wire holding cylinder 53 is set in the retreated state at the timing when the needle 11 is lifted and pulled out from the needle hole 15, and the slide plate 51 is moved to the retreated position (fig. 20, 27(B), step S11 of fig. 30).

Thereby, the lower thread D and the sewing start end portion of the upper thread U are drawn forward, and extend forward and backward below the thread drawing member 81.

Then, the wire pulling cylinder 82 is set to the retracted state, and the wire pulling member 81 is lowered (fig. 27C, step S13 of fig. 30).

As a result, as shown in fig. 23, the thread pulling member 81 catches and pulls the sewing starting end portions of the lower thread D and the upper thread U downward, and is pulled into the inside of the hook portion 621 of the fixed cutter 62 of the first thread cutting device 60.

Then, the needle movement by the sewing machine motor 117 is continued, and the second needle drop is performed (fig. 28 a).

At this time, the thread pulling cylinder 82 maintains the retreated state, and the thread pulling member 81 continues to apply a downward pulling force to the lower thread D and the sewing start end portion of the upper thread U. Therefore, if the sewing is performed and the fabric C is advanced, the lower thread D and the upper thread U are further lowered by an excessive length of the thread pulling member 81 (fig. 28B), and the sewing start end portion of the lower thread D and the upper thread U is further pulled into the inside of the hook 621 of the fixed cutter 62.

During this time, the control device 110 continues to monitor the position of the needle bar by the driving of the sewing machine motor 117, and continues to wait for the lift timing of the needle of the third needle (step S15 of fig. 30).

If the needle lift timing of the third needle is reached, the needle drop position of the first needle is directly above the thread cutting position of the first thread cutting device 60. At this timing, the first thread cutting cylinder 63 of the first thread cutting device 60 is set in the on state, and the movable knife 61 is advanced to cut the lower thread D and the sewing start end portion of the upper thread U (fig. 24, 28(C), and step S17 of fig. 30).

If the lower thread D and the sewing start end portion of the upper thread U are cut at the above-mentioned timing, the sewing start end portion of the upper thread U can be made shortest. Further, since the knot is not formed at the first needle, the sewing start end portion of the lower thread D can be sufficiently shortened even though the lower thread D hangs down from the needle drop position of the second needle of the fabric C.

In addition, when the sewing start end portion of the lower thread D is desired to be shortened more preferentially, the thread cutting may be performed at the timing of lifting up the needle of the fourth needle next time.

After the sewing is completed, the first and second thread holding cylinders 52 and 53 are set to the advanced state, and the slide plate 51 is moved to the lower thread insertion position where the second opening 512 overlaps the needle hole 15 (step S19 in fig. 29 and 30). At the same time, the fan 191 of the trap mechanism 19 is operated (step S21 in fig. 30).

Thereby, the lower thread D and the cut-off piece of the upper thread U held by the slide plate 51 are released and fall, and are captured by the capture mechanism 19.

Thereby, the cutting control of the lower thread D and the sewing start end portion of the upper thread U is finished.

[ technical effects of embodiments of the invention ]

The sewing machine 10 includes: a lower thread inserting mechanism 2 for inserting the sewing starting end of the lower thread D into the needle hole from the lower side; a sewing starting end holding mechanism 50 for holding the sewing starting end of the lower thread D passing through the needle hole 15 on the upper side of the needle plate 17; and a first thread cutting device 60 for cutting the sewing starting end of the lower thread D held by the sewing starting end holding mechanism 50.

Therefore, the sewing start end portion of the lower thread D remaining on the fabric C can be cut shorter, and the sewing quality can be improved.

The sewing machine 10 further includes a second thread cutting device 70 for cutting the lower thread D that has been completed in sewing, and for holding the bottom end portion of the cut lower thread D on the pot side as a sewing start end portion of the next sewing, the lower thread insertion mechanism 2 includes: a holding releasing mechanism 20 for releasing the holding state of the sewing starting end of the lower thread D by the second thread cutting device 70; a thread collecting mechanism 30 for collecting the thread at the sewing starting end of the lower thread D below the needle hole 15; and an air blowing mechanism 40 for inserting the sewing starting end of the lower thread D into the pinhole 15 by air after the holding state is released.

Thus, the end portion of the lower thread D on the bottom side can be held as the starting end portion of the next sewing at the end of the sewing. Further, the sewing start end portion of the lower thread D can be automatically inserted into the needle hole by the cooperative operation of the holding and releasing mechanism 20, the thread collecting mechanism 30, and the blowing mechanism 40.

Further, along with this, since the sewing start end portion of the lower thread D inserted upward from the needle hole 15 is held by the sewing start end portion holding mechanism 50 and cut by the first thread cutting device 60, the above-described series of operations can be automatically performed, and the work load can be reduced and the work efficiency can be improved.

The thread take-up mechanism 30 of the sewing machine 10 has a thread take-up hook 31, and the thread take-up hook 31 takes up the sewing start end portion of the lower thread D below the needle hole 15 by the forward movement, and the thread take-up hook 31 includes: a first inclined portion 311 formed at the front end portion to move the sewing start end portion of the lower thread D upward; a concave part 312 formed on the upper part of the front end part and used for catching the sewing starting end part of the lower thread D; and a second inclined portion 313 formed inside the concave portion 312 to move a sewing start end portion of the lower thread D downward, wherein an upper end portion of the second inclined portion 313 is formed higher than an upper end portion of the first inclined portion 311 in the thread trap hook 31.

This can widen the vertical range in which the lower thread D can be caught by the thread collecting hook 31, and can more reliably guide the lower thread D to the lower side of the pinhole 15.

The air blowing mechanism 40 of the sewing machine 10 includes nozzles 41 and 42 for blowing air toward the needle hole 15, and the nozzles 41 and 42 have slits 411 and 421 at the tip ends thereof through which the sewing start end of the lower thread D passes.

Therefore, the sewing start end portion of the lower thread D can be guided and held in the slits 411 and 421 when the nozzles 41 and 42 are raised, and the sewing start end portion of the lower thread D can be more reliably blown up and inserted into the needle hole 15.

The sewing start end holding mechanism 50 of the sewing machine 10 includes a slide plate 51, the slide plate 51 having a first opening 511 and a second opening 512 arranged in a sliding direction, and the sewing start end of the lower thread D can be held between the slide plate 51 and the opposing surface of the needle plate 17 by sliding from the lower thread insertion position where the second opening 512 and the needle hole 15 overlap, and the sewing start end of the lower thread D and the upper thread U can be held between the slide plate 51 and the opposing surface of the needle plate 17 by sliding from the upper thread insertion position where the first opening 511 and the needle hole 15 overlap.

Therefore, both the lower thread D and the sewing start end portion of the upper thread U can be held by one member, and the number of components can be reduced, and along with this, the mechanism can be made compact.

In the sewing machine 10, the slide plate 51 slides to the downstream side in the feed direction of the feed dog 14 which is the feed mechanism of the cloth, and the sewing start end portions of the upper thread U and the lower thread D are held, and the first thread cutting device 60 is disposed on the downstream side in the feed direction of the feed dog 14 of the feed mechanism with respect to the needle hole 15.

The control device 110 controls the sewing start end holding mechanism 50 to hold the sewing start end of the lower thread D before the needle drop of the first needle, to hold the sewing start end of the upper thread U after the needle drop of the first needle, and to cut the sewing start ends of the upper and lower threads by the first thread cutting device 60 after the needle drop of the second needle and the needle drop of the second needle.

This makes it possible to bring the root portions of the lower thread D and the upper thread U hanging down from the fabric close to the first thread cutting device 60 located on the downstream side in the fabric conveying direction, and to shorten the sewing start end portions of the lower thread and the upper thread remaining on the fabric side after cutting.

The sewing machine 10 is provided with a thread pulling mechanism 80 in which the movable knife 61 and the fixed knife 62 of the first thread cutting device 60 are disposed below the sliding plate 51, and the thread pulling mechanism 80 pulls down the sewing start end portions of the upper thread U and the lower thread D pulled out in the sliding direction by the sliding plate 51.

Therefore, the movable knife 61 and the fixed knife 62 of the first thread cutting device 60 can be disposed so as not to be damaged by coming into contact with the fabric, thereby protecting the fabric, and the lower thread D and the sewing start end portion of the upper thread U can be appropriately moved to the movable knife 61 and the fixed knife 62, thereby enabling more reliable cutting.

[ other examples of wire drawing mechanisms ]

The thread pulling mechanism 80 pulls the sewing starting end portions of the lower thread D and the upper thread U toward the fixed cutter 62 of the first thread cutting device 60 by one thread pulling member 81, but two thread pulling members may be used.

That is, the wire drawing device 80A shown in fig. 31 includes: a first wire member 81A having a holding portion 811A, a claw portion 812A, and an extended portion 813A; a second wire drawing member 83A having a holding portion 831A, a claw portion 832A, and an extending portion 833A; a first wire pulling cylinder 82A that supports the second wire pulling member 83A, and that pushes and contacts the holding portion 811A of the first wire pulling member 81A by raising the holding portion 831A of the second wire pulling member 83A; and a second wire drawing cylinder 84A for supporting and lifting the first wire drawing member 81A, the second wire drawing member 83A, and the first wire drawing cylinder 82A.

In the above configuration, by setting the first wire drawing cylinder 82A to the entering state, the holding portion 831A of the second wire drawing member 83A can be raised to be brought into pressure contact with the holding portion 811A of the first wire drawing member 81A, and the lower thread D and the sewing start end portion of the upper thread U can be sandwiched therebetween.

In addition, by setting the second thread pulling cylinder 84A to the retreated state in the state of sandwiching the sewing starting end portions of the lower thread D and the upper thread U, the sewing starting end portions of the lower thread D and the upper thread U can be pulled toward the cutters 61 and 62 of the first thread cutting device 60.

As described above, since the lower thread D and the sewing start end portion of the upper thread U are held and pulled, the sewing start end portions of the lower thread and the upper thread are prevented from being accidentally detached from the thread pulling members 81A and 83A, and the thread pulling operation can be performed more reliably.

[ other examples of the mechanism for holding the starting end portion of sewing ]

The sewing starting end holding mechanism 50 described above includes the linear slide plate 51, but the shape is not limited to the linear shape. For example, as shown in fig. 32 and 33, a sewing starting end holding mechanism 50A including an arc-shaped slide plate 51A may be employed.

The sewing starting end holding mechanism 50A includes: a first wire holding cylinder 52A in which a first opening 511A and a second opening 512A, which are an upper wire catching hole and a lower wire catching hole, are formed in the vicinity of one end and one end of an arc-shaped slide plate 51A, and the first wire holding cylinder 52A supports the slide plate 51A rotatably about the center of the arc as a rotation center and imparts a rotational motion to an input arm portion 54A that rotates in conjunction with the slide plate 51A coaxially; and a second wire holding cylinder 53A that moves the first wire holding cylinder 52A forward and backward in the same direction as the moving direction of the plunger of the first wire holding cylinder 52A.

In this case, the slide plate 51A is disposed so that the pinhole 15 is located on the circumference including the arc of the slide plate 51A, and the input arm 54A and the plunger of the first wire holding cylinder 52A are coupled by a shaft and a long hole, and are configured to be interlocked while allowing displacement by the arc.

Further, each configuration is arranged such that the needle hole 15 overlaps the second opening portion 512A of the slide plate 51A when both the first wire holding cylinder 52A and the second wire holding cylinder 53A are in the advanced state, the needle hole 15 overlaps the first opening portion 511A when either one of the first wire holding cylinder 52A and the second wire holding cylinder 53A is in the advanced state, and the needle hole is a retracted position which is a position where the entire slide plate 51A is separated from the needle hole 15 when both the first wire holding cylinder 52A and the second wire holding cylinder 53A are in the retracted state.

Thus, the starting end holding mechanism 50A can switch the slide plate 51A to the insertion position of the sewing starting end of the lower thread D, the insertion position and the retreat position of the sewing starting end of the upper thread U by controlling the thread holding cylinders 52A and 53A, similarly to the starting end holding mechanism 50.

Further, in the case where the sliding plate is linear, it is necessary to secure a large space for disposing the sliding plate 51 in front of the pinhole 15, but in the case where the sliding plate 51A is arc-shaped, the space for disposing can be reduced in front of the pinhole 15, and the size can be reduced.

[ limiting plate for stay wire Member ]

When the arc-shaped slide plate 51A is used, since the opening portions 511A and 512A move along an arc as shown in fig. 34, the sewing start end portions of the lower thread D and the upper thread U are deviated from each other in the front-rear direction in the left-right direction (in the case where the slide plate 51A is bent to the left side as shown in fig. 34) and are pulled when the sewing start end portions are held.

Further, since the sliding plate 51A is curved, if the width of the holding portion 811 of the wire member 81 is not designed to be larger than the width of the sliding plate 51A, the sliding plate cannot pass through the inside.

Accordingly, the sewing start end of the lower thread D or the upper thread U is too close to the end in the left-right direction of the holding portion 811 of the thread member 81, and even if the thread member 81 moves in a predetermined direction, the sewing start end of the lower thread D or the upper thread U may not be properly guided to the inside of the hook 621 of the fixed cutter 62.

Therefore, when the arc-shaped slide plate 51A is used, it is preferable that the restricting plates 85A and 86A are provided on one side in the front-rear direction of the thread pulling member 81 so as to restrict the sewing start end portions of the lower thread and the upper thread from moving in the left-right direction with respect to the width of the slide plate 51A.

Further, it is preferable that the regulating plate 85A on the inner diameter side in the bending direction of the sliding plate 51A is provided with an inclination 851A so that the sewing start end portion of the lower thread D and the upper thread U does not dig into the lower thread. Further, since the sewing start end portions of the lower thread D and the upper thread U are hard to come close to the outer diameter side, the regulating plate 86A on the outer diameter side can be omitted.

[ other examples of holding mechanisms ]

The bent portion 211 at the upper end of the locking member 21 may be configured to be adjacent from below and face the lower surface of the middle portion in the longitudinal direction of the plate spring 73.

In this configuration, the plate spring 73 is supported below the movable cutter 71 so as to be separated when no external force is applied, the release cylinder 22 is driven in a direction to raise the locking member 21 located at a position where the bent portion 211 and the lower surface of the plate spring 73 are opposed to each other in proximity, and the plate spring 73 is pressed upward via the locking member 21. By this pressing, the tip end portion of the plate spring 73 presses the movable knife 71, and the sewing start end portion of the lower thread held between the movable knife 71 and the tip end portion is held.

When the lower line is released from being held, the release cylinder 22 is driven to pull down the locking member 21 and separate the locking member 21, so that the pressing of the plate spring 73 by the locking member 21 can be released.

[ others ]

The sewing machine 10 is exemplified by a general feed sewing machine, but the respective structures for holding and cutting the sewing start end portions of the lower thread and the upper thread may be applied to other sewing machines (for example, a sewing machine for a flat seam) in which the needle bar does not swing.

Further, the case where the needle hole 15 is formed in the feed dog 14 has been described as an example, but the present invention is not limited to this, and the respective configurations for holding and cutting the sewing start end portion of the lower thread and the upper thread may be applied to a sewing machine in which a needle plate is formed with a needle hole.

Claims (7)

1. A sewing machine, which is provided with a needle hole formed at a needle plate or a feed gear,

the sewing machine is characterized by comprising:

a lower thread inserting mechanism having an air blowing mechanism for inserting a sewing start end portion of the lower thread into the needle hole from a lower side by air;

a sewing start end holding mechanism for holding a sewing start end of the lower thread passing through the needle hole on an upper side of the needle plate;

a first thread cutting device for cutting the sewing starting end of the lower thread held by the sewing starting end holding mechanism; and

a control device for controlling the operation of the sewing machine,

the air blowing mechanism is provided with a nozzle for blowing air toward the needle hole, and the nozzle is provided with a slit part for allowing the sewing starting end part of the lower thread to pass through at the front end part.

2. The sewing machine of claim 1,

the sewing starting end holding mechanism comprises a sliding plate, an upper thread catching hole and a lower thread catching hole are formed in the sliding plate in an aligned manner along the sliding direction, the sewing starting end of the lower thread and the sewing starting end of the upper thread can be clamped and held between the opposite surface of the needle plate and the sliding plate,

the sliding plate is movable to an upper thread insertion position where the upper thread catching hole and the needle hole coincide, a lower thread insertion position where the lower thread catching hole and the needle hole coincide, and a retreat position where both the lower thread catching hole and the upper thread catching hole are separated from the needle hole.

3. The sewing machine of claim 2,

the slide plate is arranged at the retreating position, and clamps and keeps the sewing starting end part of the upper thread and the sewing starting end part of the lower thread between the opposite surface of the needle plate and the slide plate,

the control device controls the sewing machine in such a manner that the sliding plate is positioned at the lower thread insertion position before the needle of the first needle is dropped, the sliding plate is positioned at the upper thread insertion position after the sewing start end portion of the lower thread is inserted into the needle hole and the lower thread catching hole from the lower side by the blowing mechanism, the sliding plate is positioned at the retreat position after the sewing start end portion of the upper thread is inserted into the needle hole and the upper thread catching hole by the needle dropping of the first needle, and the sewing start end portion of the upper thread and the sewing start end portion of the lower thread are cut by the first thread cutting device after the needle dropping of the second needle and the needle dropping of the second needle.

4. The sewing machine of claim 2,

the cutter of the first thread cutting device is arranged below the sliding plate,

the sewing machine is provided with a thread pulling mechanism which moves downwards when the sliding plate is at the retreating position, pulls the sewing starting end part of the upper thread and the sewing starting end part of the lower thread pulled by the sliding plate and enables the sewing starting end parts to be clamped with the first thread cutting device,

the control device controls the sewing machine in such a manner that the first thread cutting device cuts the sewing starting end portion of the upper thread and the sewing starting end portion of the lower thread after the thread pulling mechanism is moved downward.

5. The sewing machine of claim 2,

a second thread cutting device for cutting the lower thread after sewing and holding the end part of the cut lower thread on the side of the kettle as the sewing starting end part of the next sewing,

the inserting mechanism of inserting lower line has:

a holding releasing mechanism for releasing the holding state of the sewing starting end of the lower thread by the second thread cutting device; and

and a thread collecting mechanism for collecting the sewing starting end of the lower thread below the needle hole.

6. Sewing machine as in claim 5,

the thread collecting mechanism is provided with a thread collecting component which collects the sewing starting end part of the lower thread at the lower side of the needle hole through forward movement,

the wire collecting member includes: a first inclined portion formed at a front end portion to move a sewing start end portion of the lower thread upward; a recessed portion formed at an upper portion of the distal end portion and configured to catch a sewing start end portion of the lower thread; and a second inclined part formed inside the concave part to make the sewing starting end part of the lower thread move downwards,

an upper end portion of the second inclined portion is formed higher than an upper end portion of the first inclined portion.

7. Sewing machine as in claim 5,

the control device controls the sewing machine in such a manner that the thread collecting mechanism is driven to collect the sewing starting end portion of the lower thread on the lower side of the needle hole before the sewing starting end portion of the lower thread is inserted into the needle hole and the lower thread catching hole from the lower side by the blowing mechanism, and the holding releasing mechanism is driven to release the holding state of the sewing starting end portion of the lower thread by the second thread cutting device.

Images