JP3409990B2 - sewing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine for synchronously controlling a shuttle drive motor so as to drive a main shaft and a thread wheel catching hook independently while rotating the thread wheel catching hook in synchronization with the main shaft. In particular, the present invention relates to a device in which a shuttle drive motor is temporarily stopped or decelerated at the time of thread cutting to ensure a sufficient upper thread remaining amount after thread cutting.

[0002]

2. Description of the Related Art Conventionally, instead of a vertical shaft drive type that drives a lower shaft that drives a shuttle for catching a yarn wheel by connecting a lower shaft to a main shaft that vertically drives a sewing needle or a balance, By driving the hook with a dedicated drive motor independently of the sewing machine spindle, the thread-wheel catch hook is driven synchronously with the sewing machine spindle while controlling the momentary rotation state of the thread-loop catch hook according to the sewing conditions. The sewing machine of the shuttle shaft independent drive type
Duke Akira 60-21750, JP-A No. 3-234291
It is proposed in the official gazette.

By the way, in this kind of general sewing machine,
When driving the yarn hooking hook to synchronize with the rotation of the main shaft by the hook drive motor, the upper thread loop formed in the yarn hooking hook is temporarily caught for a predetermined period from a predetermined timing. The upper thread holding mechanism (so-called picker mechanism) is provided adjacent to the thread catcher, and at the timing during the ascending period of the balance before thread cutting during thread cutting operation,
The upper thread catching member provided in the upper thread holding mechanism is operated to temporarily catch the upper thread loop, and the upper thread remaining amount ahead of the eye of the sewing needle is sufficiently secured, and then the upper and lower threads are removed. The needle thread is cut so as to prevent the upper thread end from coming off from the eyelet hole of the sewing needle during the balance raising period at the start of the next sewing.

As described above, in the sewing machine in which the thread catching hook is independently driven, and the needle thread holding mechanism is additionally provided in the bed section adjacent to the thread catching hook, the bed section becomes large and There are problems such as high cost. In view of this, the applicant of the present application, in this type of sewing machine, controls the drive of the shuttle for catching the yarn wheel independently of the main shaft by a shuttle drive motor, and cooperates with the fixed blade in each bed by the reciprocating motion of the movable blade. A thread cutting mechanism that cuts the thread by operation is provided, and when the thread is cut at the final stitch of the sewing operation, by temporarily stopping or decelerating the drive of the hook drive motor for a predetermined period,
Sewing machine designed to secure a sufficient upper thread remaining amount (Japanese Patent Application No. 8
--83352) was proposed.

That is, in this embroidery sewing machine, at the time of cutting the thread of the final stitch, a predetermined timing immediately before the upper thread loop formed by the thread catcher is removed from the thread catcher,
For example, about 300 ° when the uppermost position of the needle bar is 0 °
The drive of the shuttle drive motor is temporarily stopped or decelerated from the timing of the rotation phase of to the rotation phase of about 335 °, and the balance is raised during this temporary stop period, whereby the shortage of thread is fed from the thread spool. When the drive of the shuttle drive motor is restarted and the upper thread loop is disengaged from the thread catcher, the movable blade that moves to the thread cutting position while catching the upper thread loop moves up and down with the fixed blade. By cutting both threads, the upper thread remaining amount can be sufficiently secured without providing an upper thread holding mechanism, and the bed portion can be downsized.

[0006]

[Patent Document 1] Japanese Patent Application No. 8-83
In the sewing machine proposed by the applicant of the present application in No. 352,
When the rotation of the hook for catching the yarn wheel is temporarily stopped or decelerated from a rotational position of about 300 ° to about 335 °, and the insufficient upper thread amount is fed from the thread spool due to the lifting of the balance during this temporary stop period, The movable blade is in the state of moving toward the fixed blade while engaging the upper thread loop at its engaging portion, and a large tension acts on the upper thread loop formed in the thread catcher hook. In this state, when the drive of the shuttle drive motor is restarted and the needle thread loop is disengaged from the shuttle for catching the yarn wheel, the needle thread loop jumps due to the reaction that the tension that has been acting up to now disappears all at once. When the yarn is a thin yarn with a particularly high elasticity, the jumping becomes large, and the needle thread loop that was engaged with the engaging portion of the moving movable blade is disengaged from the engaging portion to the outside by the jumping. Will end up
There is a problem that the thread cannot be cut.

An object of the present invention is to remove from the yarn wheel catching hook when the hook driving motor is temporarily stopped or decelerated and then the driving is restarted so as to secure a sufficient upper thread remaining amount at the time of thread cutting. Another object of the present invention is to provide a sewing machine that can reliably perform thread cutting even when the needle thread loop jumps up and down.

[0008]

Means for Solving the Problems A sewing machine according to claim 1 is
The sewing needle is driven by the sewing machine motor via the main shaft, the thread-wheel catching hook that catches the thread wheel in cooperation with the sewing needle, and the thread-wheel catching hook is driven to rotate independently of the sewing machine motor in synchronization with the main shaft. In a sewing machine equipped with a hook drive motor and a thread cutting mechanism that cuts a thread on the lower side of the needle plate, when the thread is cut by the thread cutting mechanism, the upper thread remaining amount ahead of the eyelet of the sewing needle is secured. Therefore, a control means for temporarily stopping or decelerating the shuttle drive motor for a predetermined period from a predetermined timing before the thread cutting during the thread cutting operation and immediately before the needle thread loop is disengaged from the thread catching shuttle. When the drive of the thread catching hook is restarted after the elapse of a predetermined period of time by the control means, the upper thread loop that has jumped out of the thread catching hook does not come off from the engaging portion of the moving blade during movement. With a guide member that guides you
Close to the moving area of the engaging part of the movable blade of the thread trimming mechanism.
And a guide member disposed so as to be provided.

The control means, when executing the thread cutting operation,
It is a predetermined timing before thread cutting during the thread cutting operation, for example, a timing of a rotation phase of about 300 ° when the uppermost position of the needle bar is 0 °, just before the needle thread loop is disengaged from the hook for catching the wheel. The shuttle drive motor is temporarily stopped or decelerated from a predetermined timing for a predetermined period of about 30 ° to 40 °. During this temporary stop or deceleration period, when the amount of upper thread that is insufficient due to the lifting of the balance is fed out from the thread spool,
The movable blade is in a state of rotating toward the fixed blade while engaging the upper thread loop at its engaging portion, and a large tension acts on the upper thread loop formed in the thread catcher. ing.

When the control means restarts the drive of the thread catching hook after a predetermined period of time, the needle thread loop is disengaged from the thread catching hook, and the tension that has been acting up to now disappears suddenly, causing a large reaction. You will jump. At this time, the guide member guides the jumped upper thread loop so as not to be disengaged from the engaging portion of the moving movable blade, and the thread cutting is surely performed by the cooperation of the movable blade and the fixed blade. .

[0011] In this case, the guide member is so is brought closer to the movement area of the engagement portion of the movable blade of the thread cutting mechanism is disposed, collide with the guide member during rotation for thread cutting of the movable blade Moreover, the guide member does not obstruct the movement of the needle thread loop in a normal sewing operation other than the thread cutting operation .

A sewing machine according to a second aspect of the present invention is the sewing machine according to the first aspect of the invention, wherein the guide member is arranged so as to overlap an outer peripheral side portion of a moving region of the engaging portion of the movable blade in plan view. is there. In this case, since the guide member is arranged so as to overlap the outer peripheral side portion of the moving region of the engaging portion of the movable blade in plan view, the jumping of the needle thread loop is large and the engagement of the movable blade is large. Even when jumping in the direction of coming off the joining portion, it is possible to reliably prevent the needle thread loop from coming off from the engaging portion. Other than that, the same operation as in claim 1 is achieved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is a multi-head embroidery sewing machine including three embroidery sewing machines, and in each of the embroidery sewing machines, all rotary hooks for catching the thread ring are rotationally driven by a hook drive motor independently of the sewing machine motor. This is a case where the present invention is applied. The multi-head embroidery sewing machine M will be described. As shown in FIG. 1, a sewing machine support plate 2 having a predetermined length in the left-right direction and having a predetermined length in the left-right direction is provided on the rear side of the upper surface of a base frame 1 extending in the left-right direction. And a support frame 3 extending in the left-right direction is erected at the rear end portion of the sewing machine support plate 2.
In addition, the three head portions 4 to 6 are juxtaposed in the left-right direction at predetermined intervals, and the base frame 1 located at the front end portion of the sewing machine support plate 2 corresponds to each of the head portions 4 to 6. The rear end portions of the cylindrical bed portions 7 to 9 formed in the bed units 10 to 12 are respectively supported.

That is, three multi-needle type embroidery sewing machines M1 to M3, which are composed of heads 4 to 6 provided on the support frame 3 and bed units 10 to 12 having an independent structure, are arranged in parallel. At the front end of each of the head portions 4 to 6 of the embroidery sewing machines M1 to M3, twelve needle bars (not shown) arranged in a row in the left-right direction and having sewing needles 22 attached to the lower ends can be moved up and down. The needle bar cases 20 that support the 12 scales 23 in a swingable manner are supported by the needle bar changing motor 115.
By a needle bar changing mechanism (not shown) driven by (see FIG. 8), the needle bars can be simultaneously moved in the left-right direction and changed to different embroidery threads having different thread colors at the same time.

Further, at the front end of each of the head portions 4 to 6, in addition to a needle bar vertical drive mechanism (not shown) for vertically driving the needle bar, a needle bar jump mechanism for jumping the needle bar to its uppermost position. (Not shown) and the like are provided. On the other hand, a work table 13 is horizontally arranged so as to be flush with the upper surfaces of the bed units 10 to 12 on the front side of the sewing machine support plate 2, and the work table 13 is included in the work table 13. A movable frame 16 having a rectangular frame shape in plan view extending in the left-right direction is placed over the pair of auxiliary tables 14 and 15 provided on both the left and right sides.

The drive frame portion 16b at the right end of the movable frame 16 is driven to move in the X-axis direction (left-right direction) by an X-axis drive mechanism (not shown), and at the same time as the drive frame portion 16a at the left end thereof. This drive frame portion 16b is moved and driven in the Y-axis direction (front-back direction) by a Y-axis drive mechanism (not shown).
Therefore, the movable frame 16 includes the X-axis drive mechanism driven by the X-axis drive motor 117 (see FIG. 8) and the Y-axis drive motor 119.
(See FIG. 8) The Y-axis drive mechanism drives the XY
It is movable on the plane. Also, auxiliary table 1
On the rear side of 6b, a display 18a for displaying a message relating to embroidery sewing is provided, and an operation panel 18 for executing various commands is provided.

Next, the bed units 10 to 12 will be described with reference to FIGS. Since the three bed units 10 to 12 have the same configuration, the leftmost bed unit 10 will be described. A bed case 50 having a substantially U-shaped cross section extending in the front-rear direction has a pair of support brackets 5 fixed to a base frame 1 extending in the left-right direction at the front end of the sewing machine support plate 2 at its rear end.
1, and a hook module 55 is detachably fixed to the front end portion of the bed case 50. here,
The upper side of the bed case 50 is covered with a needle plate 52 at its front end portion, and is also covered with a cover plate 53 which is continuous with the needle plate 52 and extends in the front-rear direction.

Next, the shuttle module 55 will be described. As shown in FIGS. 3 to 4, a mounting block 56 is detachably fixed to the front end portion of the bed case 50 with screws 57, and a shuttle drive motor composed of a pulse motor is provided on the rear end side of the mounting block 56. 58 is attached. On the other hand, on the front end side of the attachment block 56, a full rotary hook 59 for catching the yarn wheel is provided, and the hook shaft 60 fixed to the full rotary hook 59 is pivotally mounted on the attachment block 56 so that the position thereof can be adjusted in the front-rear direction. It is supported. The first connecting member 62 attached to the rear end of the shuttle shaft 60 and the second connecting member 63 attached to the front end of the drive shaft 58a of the shuttle drive motor 58 are connected to each other. That is, the shuttle shaft 60 and the drive shaft 58a are connected by the coupling 61 including both connecting members 62 and 63.

A brief description of the full-rotary hook 59 will now be given. As shown in FIG. 7, an inner hook 59a for holding a bobbin case 67 for accommodating a bobbin and an outer hook 59b for rotating the outside of the inner hook 59a. The outer hook 59b is formed with a sword tip 59c for hooking the upper thread 47 to form an upper thread loop 47c. When the main shaft 18 of the sewing machine is about “200 °”, the sword point 59c and the sewing needle 22
It is the timing of the encounter with the eye's eye and the sword tip 59c
At this meeting timing, the upper thread 47 extending from the eyelet of the sewing needle 22 is hooked and the outer hook 59b is rotated to form an upper thread loop 47c which moves between the inner hook 59a and the outer hook 59b.

Further, a disc encoder 64 is attached to the second connecting member 63, and a plurality of slits formed in the disc encoder 64 are optically detected to output from a photo sensor which outputs a shuttle shaft rotation signal. Become second
The encoder sensor 65 is attached to the attachment block 56. Then, by driving the shuttle drive motor 58, the shuttle shaft 60 is rotationally driven via the drive shaft 58a and the coupling 61, and the full rotary shuttle 59 is doubled in the predetermined rotation direction with respect to the sewing machine main spindle 17. It is driven to rotate at a rotation speed K. Here, the front end portion of the bed unit 10 is covered with a protective cover 66 that is pivotally supported at the lower end of the front end portion of the bed case 50 so as to be openable and closable via a hinge mechanism.

Here, a pivotal support structure for pivotally supporting the full rotary hook 59 so that its position can be adjusted in the front-rear direction will be briefly described. Immediately inside the cylindrical portion of the mounting block 56, a cylindrical bearing case 70 is provided slidably in the front-rear direction, and a bearing 71 is press-fitted into the bearing case 70. Then, the eccentric pin 72 is attached to the left side wall portion of the attachment block 56, and
The pin portion at the tip of the eccentric pin 72 is the bearing case 7.
0 is engaged with a vertically elongated pin hole formed on the left side wall,
On the other hand, a set screw 73 capable of fixing the bearing case 70 is detachably provided on the right side wall portion of the mounting block 56.

That is, by loosening the set screw 73 and rotating the eccentric pin 72 in the clockwise direction or the counterclockwise direction, the bearing case 70 is moved forward or backward by a minute distance (for example, 1 to 1) through the pin hole. 2 mm), and at the same time, the position of the entire rotary hook 59 can be finely adjusted in the front-rear direction and the needle gap can be adjusted. Next, a thread cutting mechanism 80 that is provided in each of the bed units 10 to 12 and cuts the upper thread 47 and the lower thread 48 will be described with reference to FIGS. 2 to 7. A movable blade 81 is pivotally supported on the lower surface of the needle plate 52 so as to be swingable between a standby position shown by a solid line in FIG. 5 and a rotating position shown by a two-dot chain line.

The upper thread 4 cooperates with the movable blade 81.
7 and the lower thread 48 are fixed blades 82 for cutting the movable blade 8
1 is attached to the lower side of the throat plate 52 so as to face the upper side of the No. 1 so that the blade portion faces the engaging portion 81a of the movable blade 81. On the other hand, the thread cutting operation lever 8 connected to the movable blade 81
3 extends through the inside of the bed case 50 and extends rearward.

That is, by moving the thread cutting operation lever 83 forward, the movable blade 81 rotates the needle side upper thread 47a of the upper thread 47, which has been separated, in the clockwise direction.
In the state of being hooked on 1b (see FIG. 11), after moving forward to the rotation position shown by the chain double-dashed line in FIG.
While the movable blade 81 is returning in the counterclockwise direction by the backward movement of 3, the work cloth side upper thread 47b and the lower thread 48 of the upper thread 47 are engaged with the engaging portion 81a of the movable blade 81. The work cloth side upper thread 47c and the lower thread 48 are simultaneously cut by the engagement of the movable blade 81 and the fixed blade 82.

Next, the thread trimming drive mechanism 85 for driving the thread trimming mechanism 80 will be described with reference to FIGS. 2 and 6. A rear end portion of the thread trimming operation lever 83 is horizontally attached to the rear end portion of the bed case 50 so as to be horizontally rotatable.
It is connected to the driven portion 86 a of the character-shaped rotating plate 86. On the other hand, at the left end of the base frame 1, the base frame 1
A thread trimming motor 88 is attached to a mounting plate 87 fixed to the lower side from below, and a fan-shaped swinging member 90 meshing with a drive gear 89 of the thread trimming motor 88 is rotated to the mounting plate 87 by a stepped bolt 91. It is movably pivoted. Furthermore,
A base end portion of a plate-shaped connecting plate 92 is attached to the swing member 90, and a left end portion of a thread trimming operation shaft 93 extending in the left-right direction is connected to a tip end portion of the connecting plate 92.

A drive portion 86b of the rotary plate 86 is connected to the thread cutting operation shaft 93. This allows
Rotation of the thread cutting motor 88 in the counterclockwise direction causes the swing member 90 to rotate clockwise by a predetermined angle, and the thread cutting operation shaft 93 moves rightward by a predetermined distance via the connecting plate 92. As a result, the rotating plate 86 is rotated in the clockwise direction and the thread trimming operating lever 83 is moved forward to move the movable blade 8
1 moves forward to the maximum rotation position. After that, the rotation of the thread cutting motor 88 in the clockwise direction causes the rotary plate 86 to rotate in the counterclockwise direction through the movement of the thread cutting operation shaft 93 to the left, and the thread cutting operation lever 83 moves backward. To the work cloth side upper thread 47, which is moved to the movable cloth 81 and is engaged with the movable blade 81 as described above.
c and the lower thread 48 are simultaneously cut by the movable blade 81 and the fixed blade 82.

By the way, a moving position detecting sensor 94 composed of a photosensor is attached to the mounting plate 87 near the swinging member 90, and the swinging member 90 detects the moving position detecting sensor 94. A shield plate 95 is attached. That is, since the moving position detection sensor 94 does not detect the shielding plate 95 when the movable blade 81 is moving within the moving range from the cutting position to the maximum rotation position, the moving position detection of the “L” level is performed. On the other hand, while outputting a signal, when the movable blade 81 moves to the cutting position in the backward movement direction, the shield plate 95 is detected and an “H” level moving position detection signal is output.

Next, when the thread is cut by the thread cutting mechanism 80,
Even when the upper thread loop 47c formed on the full rotary hook 59 jumps off from the full rotary hook 59, the work cloth side upper thread 47b is guided so as not to come off from the engaging portion 81a of the movable blade 81. The guide member 30 will be described with reference to FIGS. 5 and 7. At a position slightly lower than the height position of the movable blade 81 and facing the substantially right half portion of the entire rotary hook 59, the engaging portion 81a of the movable blade 81 is wrapped around the outer peripheral portion of the moving area Z. As described above, the guide member 30 is horizontally arranged, and the guide member 30 is fixed to the lower side of the needle plate 52 by a mounting portion 30a extending rightward.

That is, the guide member 30 is shown in FIGS.
As shown in FIG. 1, when the upper thread loop 47c comes off the full rotary hook 59, the movable blade 81 moving toward the standby position.
Of the engaging portion 81a and the fixed blade 52 so as to surround the right side (outside) of the space between the engaging portion 81a and the fixed blade 52 so as to wrap around the outer peripheral side portion of the moving region Z of the engaging portion 81a. Therefore, even when the upper thread loop 47c formed on the full-rotary hook 59 is recoiled when it is disengaged from the full-rotary hook 59, the guide member 30 allows the work cloth to move to the side closer to the work cloth even if the upper thread loop 47c jumps greatly to the right of the full-rotary hook 59. Upper thread 4
7b is reliably guided so as not to come off from the engaging portion 81a to the outside.

Next, the outline of the control system of the multi-head embroidery sewing machine M will be described with reference to the block diagram of FIG. A sewing machine control device 100 that controls the entire embroidery sewing machine M other than the hook drive control includes a CPU 101, a ROM 102, and a RAM.
And an input interface (not shown) and an output interface (not shown) connected to the microcomputer via a bus such as a data bus.

With respect to the head section 4, a drive circuit 105 for the needle bar jump solenoid 41 provided in the needle bar jump mechanism and a thread break sensor 108 are connected to the sewing machine control device 100, and other heads are connected. The parts 5 and 6 are similarly connected. Further, the sewing machine control device 10
0 is a drive circuit 111 for driving the sewing machine motor 110.
And a first output of 1000 slit signals by one rotation of a disk encoder provided on the sewing machine motor 110.
The encoder sensor 112, the spindle origin sensor 113 that outputs one spindle origin signal by one revolution of the first encoder sensor 112, and the stop position of the needle bar (the rotation position of the sewing machine spindle 17 of about 100 °) are detected. Stop position sensor 11
4, a drive circuit 116 for a needle bar changing motor 115 for changing the needle bar to be driven by moving the needle bar case 20, and X
A drive circuit 118 for the axis drive motor 117, a drive circuit 120 for the Y axis drive motor 119, a plurality of switches for instructing sewing start and various commands, and a display 18a are provided. Operation panel 18
Are connected to each other.

On the other hand, it is connected to the sewing machine controller 100,
The shuttle shaft control device 150 (corresponding to a control unit) that controls the drive of the shuttle drive motor 58 and the thread cutting mechanism 80 is the CPU 1
51, a ROM 152 and a RAM 153, and an input interface (not shown) and an output interface (not shown) connected to the microcomputer via a bus such as a data bus. With respect to the bed unit 10, a drive circuit 154 for the shuttle drive motor 58 and a second encoder sensor 65 that outputs 50 slit signals per revolution of the disk encoder 64 are provided to the shuttle shaft control device 150.
And a hook shaft origin sensor 155 that outputs one hook shaft synchronizing signal by one rotation of the disk encoder 64, and the other bed units 11 and 12 are connected in the same manner.

Furthermore, the shuttle shaft control device 150 includes a movable blade 8
The moving position detection sensor 94 for detecting the moving position of No. 1 and the drive circuit 156 for the thread trimming motor 88 are respectively connected. Here, the shuttle shaft control device 150 corresponds to a control means. Next, the operation of the guide member 30 at the time of thread cutting at the final stitch of the sewing operation will be described. When sewing of this multi-head type embroidery sewing machine M is started, the sewing machine main shaft 17 and shuttle shaft 6 are
After 0 is initialized respectively, the sewing machine motor 110 and the shuttle drive motor 58 are synchronously driven and controlled based on the embroidery data having the needle drop data for N stitches created in advance to sew N stitches. Is executed.

By the way, at the time of the final stitch of the Nth stitch, when a thread cutting command is received from the sewing machine control device 100 and the hook shaft control device 150 executes the thread cutting, as shown in FIG. During the sewing operation of the sewing machine, the shuttle shaft 60 is rotationally driven at a predetermined rotation speed K until the sewing machine main spindle 17 reaches the rotational position of about 300 °.
When the rotation position of 7 reaches about 300 ° (corresponding to the predetermined timing before thread cutting), the sewing machine spindle 17 moves about 3
Until the angle reaches 35 ° (this corresponds to a predetermined period), the drive of the shuttle drive motor 58 is temporarily stopped, and the rotation of the shuttle shaft 60 is forcibly stopped temporarily.

That is, when the sewing machine main shaft 17 is about 300 ° to about 335 ° during the sewing of the Nth stitch, the full rotary hook 59 is in the stopped state at the rotation position shown in FIGS. When the loop 47c is maximally formed and cannot be disengaged from the full rotary hook 59, and since the balance 23 is in the ascending period, the shortage of yarn amount according to the ascent of the balance 23 is
Since it is fed from a thread spool (not shown), a large tension acts on the upper thread loop 47c formed on the full rotary hook 59.

On the other hand, in the thread cutting mechanism 80, the thread cutting motor 88 is driven by the thread cutting command, and first the movable blade 8 is moved.
1 is rotated to the rotation position. At this time, the full rotary hook 59
Only the needle side upper thread 47a from the sewing needle 22 is separated by the bifurcated thread guide portion 59d (see FIG. 7) formed on the outer peripheral portion of the outer hook 59b facing the sword tip 59c. The thread 47a is hooked and separated by the protruding portion 81b of the movable blade 81, and the lower thread 48 and the upper thread 47b on the work cloth side can be engaged with the engaging portion 81a of the movable blade 81.

Then, when the thread cutting motor 88 is driven in the reverse direction to move the movable blade 81 counterclockwise and the sewing machine main shaft 17 is at the rotation position of about 335 °, as shown in FIG. The thread 48 and the upper thread 47b on the work cloth side are engaged with the engaging portion 81a. Here, in FIG. 10, for convenience of description, the upper thread (needle thread) 47a from the sewing needle 22 and the work cloth W on the horizontal plane where the movable blade 81 is located.
The upper thread 47b and the lower thread 48 connected to each other are shown.

On the other hand, when the sewing machine main shaft 17 reaches the rotational position of about 335 °, when the shuttle drive motor 58 is restarted and the full rotary shuttle 59 is rotated again, the upper thread loop 47c is fully rotated. It will come off from the kettle 59 at a stretch,
At the time of this disengagement, as shown in FIGS. 7 and 11, the upper thread loop 47c is a reaction that the tension that has been acting up to now disappears at once, and jumps to the upper side on the right side of the full rotary hook 59. The upper thread loop 47c that is jumped up by the guide member 30 is engaged with the engaging portion 81 of the movable blade 81 during movement.
The yarn is reliably guided so as not to come off from a, and thereafter, the thread cutting is reliably performed by the cooperation of the movable blade 81 and the fixed blade 82.

As described above, when the upper thread loop 47c is disengaged from the full rotary hook 59, the right side of the space between the fixed blade 52 and the engaging portion 81a of the movable blade 81 moving toward the standby position is surrounded. Since it is provided so as to wrap around the outer peripheral side portion of the moving area Z of the engaging portion 81a, the sewing machine main shaft 17 is approximately 335
When the driving of the full rotary hook 59 is restarted after a predetermined period of reaching 0 °, when the upper thread loop 47c is disengaged from the full rotary hook 59 at once, the tension acting on the upper thread loop 47c is released. Even if the upper thread loop 47c jumps largely to the upper side, it can be reliably guided by the guide member 30 so that the upper thread loop 47c that jumps does not come off from the engaging portion 81a of the movable blade 81 in the middle of movement, and the thread cutting mechanism 80 Thread cutting can be reliably performed.

Further, since the guide member 30 is disposed close to the moving area Z of the engaging portion 81a of the movable blade 81 of the thread cutting mechanism 80, it is guided when the movable blade 81 is rotated for thread cutting. The guide member 30 does not collide with the member 30, and the movement of the needle thread loop 47c in a normal sewing operation other than the thread cutting operation is not obstructed by the guide member 30. Here, as a modification of the embodiment, the guide member 30 is configured by a wire member or a guide rod arranged so as to wrap with the outer peripheral side portion of the moving region of the engaging portion of the movable blade in plan view. May be. Various modifications may be made to the above-described embodiment based on existing technology or technology obvious to those skilled in the art.

For example, in the embodiment, the full rotary hook 59
However, a half-turn hook may be used. Also,
In the embodiment, the drive of the full rotary hook 59 is stopped for a predetermined period when the sewing machine main shaft 17 reaches from about 300 ° to about 335 °, but the drive of the full rotary hook 59 is decelerated to a substantially stop for a predetermined period. By rotating at a similar speed, the same operation as stopping may be performed. Further, it is needless to say that the present invention can be applied to various sewing machines which are provided with one embroidery sewing machine and in which the thread catcher hook is driven independently of the sewing machine motor.

[0042]

According to the sewing machine of claim 1, a sewing needle driven by a sewing machine motor via a main shaft, a thread wheel catching hook for catching a thread wheel in cooperation with the sewing needle, and a thread wheel catching hook are provided. In a sewing machine equipped with a shuttle drive motor that is driven to rotate independently of the sewing machine motor in synchronization with the main shaft, and a thread cutting mechanism that cuts the thread on the lower side of the needle plate, the upper thread loop is disengaged from the thread catcher hook. Since the control means for temporarily stopping or decelerating the shuttle drive motor for a predetermined period from the immediately preceding predetermined timing and the guide member are provided, even when the needle thread loop jumps due to its reaction when it is disengaged from the thread catcher. By the guide member, the jumped upper thread loop can be reliably guided so as not to be disengaged from the engaging portion of the moving blade during movement, and the thread cutting by the thread cutting mechanism can be reliably performed.

[0043] Then, the guide member is so is brought closer to the movement area of the engagement portion of the movable blade of the thread cutting mechanism is arranged,
The movable blade does not collide with the guide member at the time of turning for thread cutting, and the movement of the upper thread loop in a normal sewing operation other than the thread cutting operation is not obstructed by the guide member. The sewing machine according to claim 2 has the same effect as that of claim 1, but the guide member is arranged so as to overlap the outer peripheral side portion of the moving region of the engaging portion of the movable blade in plan view. Therefore, even when the jumping of the needle thread loop is large and jumps in the direction of coming off the engaging portion of the movable blade, it is possible to reliably prevent the needle thread loop from coming off the engaging portion of the needle thread loop.

[Brief description of drawings]

FIG. 1 is a perspective view of a multi-head type embroidery sewing machine.

FIG. 2 is a plan view of relevant parts showing a work table and a bed unit.

FIG. 3 is a partial plan view of a bed unit provided with a shuttle module.

FIG. 4 is a partial vertical sectional side view of a bed unit provided with a shuttle module.

FIG. 5 is a partially enlarged plan view of the leading end of the bed unit.

FIG. 6 is an enlarged plan view of a thread trimming drive mechanism.

FIG. 7 is a front view of a full rotary hook when the main shaft of the sewing machine is about 300 °.

FIG. 8 is a block diagram of a control system of the multi-head type embroidery sewing machine.

FIG. 9 is a diagram showing a rotary speed of a shuttle shaft during thread cutting.

FIG. 10 is a plan view of the thread trimming mechanism when the driving of the full rotary hook is restarted.

FIG. 11 is a schematic perspective view of the movable blade, the fixed blade, and the guide member when the driving of the full rotary hook is restarted.

[Explanation of symbols]

M Multi-head embroidery sewing machine 17 sewing machine spindle 22 sewing needles 30 Guide member 47 Upper thread 47c needle thread loop 59 full rotary hook 80 thread trimming mechanism 81 movable blade 81a engaging part 82 fixed blade 110 sewing machine motor 150 hook axis control device Z movement area 58 hook drive motor

Continuation of front page (56) Reference JP-A-9-239173 (JP, A) JP-A-8-215468 (JP, A) JP-A-3-234291 (JP, A) JP-A-8-299649 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D05B 1/00-97/12

Claims (2)

(57) [Claims] 1. A sewing needle driven by a sewing machine motor via a main shaft, a yarn wheel catching hook for catching a yarn wheel in cooperation with the sewing needle, and a thread wheel catching hook for the main spindle independently of the sewing machine motor. A sewing machine equipped with a shuttle drive motor that is driven to rotate synchronously and a thread trimming mechanism that cuts a thread on the lower side of the needle plate. In order to secure the remaining amount of thread, the hook drive motor is temporarily stopped for a predetermined period from the predetermined timing before thread cutting during thread cutting operation and immediately before the needle thread loop comes off from the thread catcher Alternatively, the control means for decelerating, and when the control means restarts the driving of the shuttle for catching the yarn wheel after the predetermined period of time, the upper thread loop that has jumped off from the shuttle for catching the yarn wheel catches the moving blade of the moving blade. A plan to guide the engagement part so that it does not come out A member thread cutting machine
It was placed close to the moving area of the engaging part of the movable blade of the structure
A sewing machine comprising: a guide member . 2. The sewing machine according to claim 1, wherein the guide member is arranged so as to overlap an outer peripheral side portion of a moving region of the engaging portion of the movable blade in a plan view.