JP6560913B2 - sewing machine - Google Patents

Description

  The present invention relates to a sewing machine that performs processing of a sewing start end portion of an upper thread.

The conventional sewing machine is provided with an upper thread holding device having a clamping means for clamping the sewing start end of the upper thread between the needle plate and the shuttle, and when the first needle is dropped, the upper end of the upper thread is sewn. When the needle is pulled up by the balance after dropping the first stitch where no knot is formed, the sewing start end of the upper thread is prevented from being pulled out from the eye hole of the fabric or the sewing needle.
In addition, since this upper thread holding device prevents the upper thread sewing start end from being pulled out, the length of the upper thread sewing start end that is passed through the stitch hole of the sewing needle is set to the minimum necessary length in advance. Thus, the length of the sewing start end of the upper thread that hangs down from the cloth after sewing can be shortened.

  In addition, the upper thread holding device releases the sewing thread from the start of sewing until the sewing start end is continuously clamped until a plurality of stitches are sewn. By sewing the stitches in the sequentially formed seams, the sewing start end is prevented from hanging down for a long time after being released from the upper thread holding device (see, for example, Patent Document 1).

JP 2004-187858 A

  However, as described above, in the method in which the sewing start end portion of the upper thread is sewn into the formed seams, the stitches are disturbed by the stitch start end portions that are sewn together, and the appearance of the seams around the sewing start position is impaired. It has been a problem to deteriorate the sewing quality.

  An object of the present invention is to improve the sewing quality.

The invention according to claim 1 is a sewing machine,
A needle plate in which a needle hole into which a sewing needle is inserted is formed;
A needle up-and-down movement mechanism for moving up and down the sewing needle;
A hook mechanism that captures the upper thread from the sewing needle below the needle plate and entangles the lower thread,
A thread trimmer provided between the needle plate and the shuttle mechanism, and for cutting an upper thread by a cutting operation of a moving knife;
An upper thread holding device that is provided between the thread trimming device and the shuttle mechanism and holds a sewing start end of the upper thread;
In a sewing machine comprising:
Controlling the upper thread holding device so as to perform the holding operation of the sewing start end of the upper thread after the first needle drop and before the second needle drop,
A control device is provided for controlling the thread trimming device so as to cut the sewing start end of the upper thread after the second needle drop.

Furthermore, the invention of claim 1
The thread trimming device includes a moving knife that performs a reciprocating operation including forward and backward movements, a fixed knife that cuts the sewing end ends of the upper thread and the lower thread in cooperation with the moving knife, and a reciprocating operation to the moving knife. With actuator to give
The moving knife has a threading part that sorts the cutting part of the upper thread and the lower thread and the non-cutting part of the upper thread when moving forward, and a blade part that performs cutting when moving backward,
The control device waits the blade portion of the moving knife on the downstream side in the forward direction from the needle hole before the needle drop of the first needle, and moves the blade portion of the moving knife to the fixed knife after the needle drop of the second stitch The actuator is controlled to move backward.

The invention according to claim 2 is the sewing machine according to claim 1 ,
The moving knife has a through hole in which the blade portion is formed at an opening edge portion,
The control device controls the actuator so that the moving knife waits at a position where the through hole and the needle hole overlap before the first needle drop.

The invention according to claim 3 is the sewing machine according to claim 1 or 2 ,
A moving mechanism for moving the workpiece along the upper surface of the needle plate;
A remaining end excision mechanism provided on the needle plate or around the needle plate and excising an end of an upper thread that hangs down from the sewing product;
The control device is configured to move a sewing start end portion of the upper thread or a sewing end end portion of the upper thread of the sewing product to the remaining end excision mechanism, and to execute a cutting operation by the remaining end excision mechanism. It is characterized by performing.

The invention according to claim 4 is the sewing machine according to any one of claims 1 to 3 ,
A suction mechanism for collecting a sewing start end of an upper thread cut from a sewing product is provided.

The invention according to claim 5 is the sewing machine according to any one of claims 1 to 4 ,
The upper thread holding device is
The sewing needle at the time of lowering is loosely inserted, and includes a thread catching portion formed in a frame shape for surrounding the periphery of the sewing needle at the time of lowering,
The thread catching portion surrounds the periphery of the sewing needle by a U-shaped portion having an opening directed to the vertical movement path of the sewing needle and an opening / closing body capable of opening and closing the opening of the U-shaped portion. It has a frame shape,
The thread catcher holds the sewing thread start end of the upper thread inside the U-shaped part,
The control device is configured to disengage the upper thread holding device so as to open the opening of the U-shaped portion closed by the opening / closing body after the sewing start end portion of the upper thread is cut by the thread trimming device. It is characterized by controlling.

In the present invention, the upper thread holding device holds the sewing start end of the upper thread when the first stitch is dropped, and the thread trimming device cuts the sewing start end of the upper thread after the second stitch is dropped. Shortening the sewing start end of the upper thread generated in the sewing product while avoiding the sewing start end of the shortened upper thread after cutting from coming off from the first needle drop position in the sewing product Is possible. As a result, the sewing quality can be improved.
In addition, since the sewing start end of the upper thread is cut after the second stitch, the sewing start end of the upper thread can be avoided from being sewn into the stitch, and the sewing quality can be improved. Become.

It is a schematic block diagram of the sewing machine which is embodiment of this invention. It is a perspective view of a sewing machine. It is a block diagram of the control system of a sewing machine. It is a bottom view of a thread trimming device. It is a disassembled perspective view which shows an upper thread holding | maintenance apparatus. It is the perspective view which looked at the upper thread holding | maintenance apparatus from the bottom. It is (A) top view (B) side view for demonstrating the "initial position" of each member which comprises a clamping means, a drive means, and a detection means. It is a perspective view for demonstrating the "initial position" of a clamping means. It is (A) top view (B) side view for demonstrating the "intermediate holding position" of each member which comprises a clamping means, a drive means, and a detection means. It is (A) top view (B) side view for demonstrating the "upper thread holding position" of each member which comprises a clamping means, a drive means, and a detection means. It is a perspective view for demonstrating the "upper thread holding position" of a clamping means. It is sectional drawing which shows the state just before the 1st stitch of the composition below the needle plate. It is sectional drawing which shows the state just before the 2nd needle | hook of the structure of the lower side of a throat plate. It is sectional drawing which shows the state immediately after the 2nd needle | hook of the structure of the lower side of a throat plate. It is a flowchart of the thread trimming operation at the time of sewing. It is a disassembled perspective view of the principal part in the other example of an upper thread holding | maintenance apparatus. FIG. 17A is a perspective view of an upper plate in another example of the upper thread holding device, FIG. 17A shows a state in which the opening / closing plate is closed, and FIG. 17B shows a state in which the opening / closing plate is opened. FIG. 18A is a bottom view of the upper plate in another example of the upper thread holding device, FIG. 18A shows a state in which the opening / closing plate is closed, and FIG. 18B shows a state in which the opening / closing plate is opened.

[First embodiment: Overall schematic configuration of a lockstitch machine]
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 is a schematic configuration diagram of a sewing machine 10 according to the present embodiment, FIG. 2 is a perspective view, and FIG. 3 is a block diagram of a control system.
The sewing machine 10 is a so-called electronic cycle sewing machine, and includes a sewing machine frame 20, a needle vertical movement mechanism 30 that moves the needle bar 12 that holds the sewing needle 11 up and down, and a needle drop position of the sewing machine bed portion 21 of the sewing machine frame 20. A needle plate 16 provided on the needle plate 16, a hook mechanism 50 that entangles the upper thread U of the sewing needle 11 with the lower thread D on the lower side of the needle plate 16, and the cloth K as the sewing object X− A feed mechanism 60 as a moving mechanism that arbitrarily moves along the Y plane, an upper thread holding device 130 that holds a sewing start end U0 of the upper thread U, and an upper thread U and a lower thread D after the needle drop of the final needle Is cut from the lower end of the upper thread holding device 130, the thread cutting device 80 for cutting the thread, the remaining end cutting mechanism 100 for cutting the remaining ends of the upper and lower threads U and D after being cut by the thread cutting device 80. A suction mechanism 110 that performs the above-described operation and the operation control of each of the above-described configurations. And a control unit 120 that performs.
Since the thread tension device, the balance, the intermediate presser mechanism and the like are well-known mechanisms mounted on the sewing machine, illustration and detailed description thereof are omitted.
Hereafter, each said structure is demonstrated in order.

[Sewing frame]
The sewing machine frame 20 extends along the sewing machine bed part 21 from the upper part of the sewing machine bed part 21, the sewing machine standing part 22 raised upward from one end part of the sewing machine bed part 21, and the sewing machine bed part 21. The sewing machine arm portion 23 extends in this manner.
Here, in describing the configuration of the sewing machine 10, a vertical movement direction of a needle bar 12 to be described later is a Z-axis direction, which is a direction perpendicular to the Z-axis direction and parallel to the longitudinal direction of the sewing machine bed portion 21 and the sewing machine arm portion 23. The direction is the Y-axis direction, and the direction orthogonal to both the Z-axis direction and the Y-axis direction is the X-axis direction. In addition, when the sewing machine 10 is installed on a horizontal plane, the Z-axis direction is a vertical vertical direction, and the X-axis direction and the Y-axis direction are horizontal directions.

A horizontal work table 14 is provided at one end (front side) of the upper portion of the sewing machine arm 23, and a needle plate 16 having a needle hole 161 is provided at the needle drop position. .
Inside the sewing machine arm portion 23, a main shaft 32 directed parallel to the longitudinal direction (Y-axis direction) is rotatably supported.
In addition, on the inner side of the sewing machine bed portion 21, a lower shaft 51 directed parallel to the longitudinal direction (Y-axis direction) is rotatably supported.
The main shaft 32 and the lower shaft 51 are respectively fixedly equipped with sprockets 33 and 52, and torque is transmitted from the main shaft 32 to the lower shaft 51 via a toothed belt 53.

[Needle vertical movement mechanism]
As shown in FIG. 1, the needle up-and-down moving mechanism 30 includes a sewing machine motor 31 including a servo motor provided on the upper portion of the sewing machine standing body 22, and a main shaft 32 that rotates by being connected to an output shaft of the sewing machine motor 31. A needle bar crank 34 fixedly provided at an end of the main shaft 32 on the sewing machine surface side, a crank rod 35 having one end connected to a position eccentric from the rotation center of the main shaft 32 in the needle bar crank 34, a needle The needle bar 12 is connected to the other end portion of the crank rod 35 through a bar holder 36.
The needle bar 12 holds the sewing needle 11 at its lower end, and is supported by the sewing machine arm 23 so as to be capable of reciprocating up and down along the Z-axis direction.
The sewing machine motor 31 is a servo motor and includes an encoder 37 (see FIG. 2). Then, the control device 120 detects the rotation speed, the spindle angle, and the like of the sewing machine motor 31 from the encoder 37, and performs operation control on the sewing machine motor 31.
The configurations of the needle bar crank 34, the crank rod 35, the needle bar holder 36, etc. are the same as known ones, and therefore detailed description thereof is omitted.

[Feed mechanism]
As shown in FIGS. 1 and 2, the feed mechanism 60 moves the fabric K along the upper surface of the horizontal needle plate 16 and arbitrarily moves and positions the sewing needle 11.
Therefore, the feed mechanism 60 is supported on the upper surface of the sewing machine bed portion 21 so as to be movable up and down by the lower plate 61 and the base 62 movably supported along the X-axis direction and the Y-axis direction. A cloth presser 63 for holding the cloth K from above the plate 61, a lifting motor 64 for moving the cloth presser 63 up and down, and a drive source for moving the cloth presser 63 along the X-axis direction via the base 62 And an Y-axis motor 66 serving as a drive source for moving the cloth presser 63 along the Y-axis direction via the base 62.

The lower plate 61 is a long flat plate provided along the XY plane, and the front end portion thereof has a rectangular frame shape, and the center portion is wide open.
The base 62 is erected on the rear end side of the upper surface of the lower plate 61, and the base 62 and the lower plate 61 move along the XY plane together with the cloth presser 63.
A cloth presser 63 supported by the base 62 is disposed above the front end of the lower plate 61. The cloth presser 63 has a rectangular frame shape and is supported so as to be movable up and down along a long hole formed in the front end portion of the base 62. The base 62 is equipped with a lift lever (not shown) whose tip is swung up and down by a lift motor 64, and the cloth presser 63 is engaged with the tip of the lift lever to be lifted. .

  Each of the X-axis motor 65 and the Y-axis motor 66 is a stepping motor whose operation amount is controlled by the control device 120. The sewing machine bed portion 21 incorporates a known transmission mechanism that converts the torques of the X-axis motor 65 and the Y-axis motor 66 into linear motions in the X-axis direction and the Y-axis direction, respectively. Linear motions in the X-axis direction and the Y-axis direction are transmitted from the shaft motor 66 to the base 62 and the lower plate 61.

[Hook mechanism]
The hook mechanism 50 has a horizontal hook, an inner hook that houses a bobbin wound with a lower thread D on the inside, an outer hook that rotates around the inner hook and captures the upper thread U from the sewing needle 11, and an outer hook. A hook shaft that applies rotational force to the hook, a gear mechanism that transmits torque from the lower shaft 51 to the hook shaft, and a hook base are provided.
The hook shaft is supported by the hook base so as to be rotatable around the Z axis, and rotation is transmitted from the lower shaft 51 at double speed. That is, the outer hook of the hook mechanism 50 rotates at a double speed of the main shaft 32.

[Thread trimming device]
FIG. 3 shows a bottom view of the thread trimming device 80.
The thread trimmer 80 includes a moving knife 81 that rotates about the Z axis, a fixed knife 82 that cuts the upper thread U and the lower thread D in cooperation with the moving knife 81, and a rotating operation of the moving knife 81. And a plurality of link bodies 83 to 85 that transmit the reciprocating rotation from the thread trimming motor 83 to the moving knife 81.

The moving knife 81 cuts the sewing end ends of the upper thread U and the lower thread D by reciprocating rotation by forward and backward movement. Further, the moving knife 81 also cuts the sewing start end portion of the upper thread U by operation control described later.
Here, first, the structure of the moving knife 81 and the cutting operation of the sewing end ends of the upper thread U and the lower thread D will be described.
The moving knife 81 stands by at the position P1 when not in use, and moves forward from the position P1 to the position P4 through the positions P2 and P3, and then passes from the position P4 to the positions P2 and P3. Backward rotation is performed up to P1, and the upper end of the upper thread U and lower thread D are cut.

Note that the upper thread U and the lower thread D are suspended from the needle hole 161 of the needle plate 16 after the needle drop of the last needle at the end of sewing. At this time, since the upper thread U is pulled out in a loop shape by the horizontal hook, the part on the sewing needle 11 side and the part on the fabric side of the upper thread U are suspended below the needle hole 161.
The thread trimming device 80 needs to cut only the fabric side portion of the upper thread U on the sewing needle 11 side and the fabric side portion and the lower thread D. The upper thread U is separated into a portion on the sewing needle 11 side (non-cut portion), a portion of the upper thread U on the fabric side (cut portion), and the lower thread D, and the upper thread is rotated when moving backward. Cut the fabric side portion of U and the lower thread D.

For this reason, the moving knife 81 has a threading portion for selecting a portion on the sewing needle side, a portion on the fabric side, and a lower thread D on the side edge portion on the downstream side in the forward direction (referred to as the front side). 811, and a concave capturing portion 813 that captures the fabric side portion of the upper thread U and the lower thread D and carries them to the fixed knife 82 at the side edge on the downstream side (rear side) in the backward direction. Yes.
Further, a through hole 814 is formed between the stringing portion 811 and the capturing portion 813 and closer to the front side, and a blade portion 812 is formed at the front inner edge of the through hole 814.

  The stringing portion 811 is formed in a sharp shape in the forward direction, and is formed at a position that passes just below the needle hole 161 when the moving knife 81 rotates. The leading end of the threading portion 811 has a radius at a portion of the upper thread U hanging from the needle hole 161 on the sewing needle 11 side, a portion on the fabric side, and a portion of the lower thread D on the sewing needle 11 side. On the inner side in the direction, the fabric side portion of the upper thread U and the lower thread D are selected radially outward.

The fabric side portion and the lower yarn D of the upper yarn U selected radially outward by the stringing portion 811 follow the outer edge portion of the moving knife 81 and wrap around to the catching portion 813 on the downstream side in the backward direction. Part 813 is captured.
When the moving knife 81 moves backward and rotates, if the catching portion 813 passes the fixed knife blade edge 821, the upper thread U between the upper surface of the moving knife 81 and the lower surface of the fixed knife 82 and the lower portion of the upper thread U The thread D is sandwiched.
When the moving knife 81 continues to further rotate backward, the upper thread U sandwiched between the upper surface of the moving knife 81 and the lower surface of the fixed knife 82 and the lower thread D are pushed through so that the lower thread D is pushed in. When entering the hole 814 and the blade portion 812 and the blade edge of the fixed knife 82 pass each other, the cloth side portion of the upper thread U and the lower thread D are cut.

Next, the structure of the moving knife 81 and the cutting operation of the sewing start end of the upper thread U will be described.
The thread trimmer 80 captures the sewing start end of the upper thread U when the first stitch is dropped, and performs cutting after the second stitch is dropped.
As described above, the moving knife 81 has the through hole 814 formed therein, and this through hole 814 has a long hole shape, and the through hole 814 overlaps the needle hole 161 by the rotation of the moving knife 81. It is an arrangement. The through hole 814 has a long hole shape along the circumferential direction by rotation, and is somewhat wider than the diameter of the needle hole 161.

  The moving knife 81 is previously positioned at the position P3 before the first needle drop at the start of sewing. In this position P3, the through hole 814 overlaps the needle hole 161, and the sewing needle 11 drops the first stitch inside the through hole 814. When the first stitch is dropped, the upper thread U is pulled out to the lower side of the fabric K by the horizontal hook, so that the knot with the loop and the lower thread D is not formed, and the thread end is It will be in the state of hanging down through the through hole 814.

Then, the moving knife 81 rotates in the backward direction and moves to the position P2 in order to avoid interference with the sewing needle 11 that performs needle drop of the second stitch. This position P2 is a state in which the entire moving knife 81 is on the rear side of the needle hole 161, and the blade portion 812 located at the front end portion of the through hole 814 is located somewhat before the cutting edge 821 of the fixed knife 82. It is.
This position P2 is a position for maintaining the state where the sewing start end portion of the upper thread U in the through hole 814 is not cut while avoiding interference between the moving knife 81 and the sewing needle 11.

  Then, when the sewing needle 11 after dropping the second stitch is raised above the needle plate 16, the moving knife 81 is rotated to the position P1 by the backward rotation, and the upper thread U passed through the through hole 814 is sewn. Cut off the starting edge.

  As described above, since the moving knife 81 needs to be positioned at the four positions P1 to P4, the thread trimming motor 83 serving as a driving source for the rotation operation is a motor that can control the operation amount, for example, stepping. A motor is used.

[Upper thread holding device]
As shown in FIGS. 5 to 11, the upper thread holding device 130 has a holding state in which the end portion of the upper thread is clamped (held) between the holding surface and the clamping surface, and the upper thread holding device is held (held). Thread grip A as a clamping means that can be switched between a release state in which the end is opened, a drive means B that relatively moves the thread grip A to switch between a holding state and a release state, and an operating position of the drive means B It is comprised with the detection means C which detects this.

  The thread clamp A includes a lower plate 131 as a holding member having a holding surface 1316 and an upper plate 144 having a clamping surface 1325 disposed to face the holding surface 1316.

As shown in FIG. 5, the lower plate 131 is a substantially flat plate-like member that is long in a certain direction, and the longitudinal direction of the lower plate 131 is parallel to the Y-axis direction while being supported by the driving unit B. A rectangular through hole 1312 is formed in the front end portion 1311 of the lower plate 131 along the longitudinal direction of the lower plate 131, and an inner surface that is the most distal side among the four inner peripheral surfaces corresponding to the quadrangle of the through hole 1312. Becomes the holding surface 1316. The holding surface 1316 is parallel to the XZ plane when the lower plate 131 is supported by the driving unit B. Further, a slit-shaped hole 1313 is formed on the rear end side of the lower plate 131 along the longitudinal direction of the lower plate 131. Further, the lower plate 131 is provided with a front pin 1314 that protrudes downward from the lower surface thereof, and a left pin 1315 that protrudes downward slightly to the left rear of the front pin 1314.
The holding surface 1316 functions as a holding surface for sandwiching the upper thread U between the holding surface 1325 and the holding surface 1325.

As shown in FIG. 5, the upper plate 144 includes a tip member 132 having a clamping surface 1325 and an upper plate body 133 that connects and holds the tip member 132 to the front end portion 1331.
The tip member 132 has a sandwiching portion 1322 that extends downward in FIG. 5 on the front end side of the tip member main body 1321, and a protrusion 1323 that projects forward from the lower end of the sandwiching portion 1322 in FIG. A connecting hole 1324 is formed on the rear end side of the member main body 1321. The front surface of the clamping portion 1322 functions as a clamping surface 1325 for clamping the upper thread U between the holding surface 1316 and the holding surface 1316. The clamping surface 1325 is parallel to the XZ plane in a state where the tip member 132 (upper plate 144) is supported by the driving unit B.
The upper plate body 133 is a substantially flat member that is slightly shorter than the lower plate 131. A connecting projection 1332 that protrudes downward is provided at the lower portion of the front end portion 1331 of the upper plate body 133. Further, the upper plate 144 is provided with a rear pin 1333 that protrudes downward from the lower surface thereof, and a right pin 1334 that protrudes downward slightly to the right of the rear pin 1333.
Then, by fitting and connecting the connecting hole 1324 of the tip member 132 and the connecting protrusion 1332 of the upper plate main body 133, the tip member 132 and the upper plate main body 133 are assembled together to form the upper plate 144. .

In the thread clamp A, the sandwiching portion 1322 and the protruding portion 1323 of the tip member 132 in the upper plate 144 are inserted into the through hole 1312 of the lower plate 131, and the rear pin 1333 of the upper plate 144 is the hole portion 1313 of the lower plate 131. The upper plate 144 and the lower plate 131 are overlapped with each other so that the upper plate 144 and the lower plate 131 are relatively movable in the longitudinal direction.
The front pin 1314 of the lower plate 131 and the rear pin 1333 of the upper plate 144 are inserted through a hole portion 1372 of a guide 137 described later, and are connected via a coil spring 139 below the guide 137. .
In the state in which the coil spring 139 is most contracted, the front pin 1314 of the lower plate 131 and the rear pin 1333 of the upper plate 144 are closest to each other, and the left pin 1315 of the lower plate 131 and the right pin 1334 of the upper plate 144 are both The closest. That is, in this state, the left pin 1315 and the right pin 1334 sandwich the lower plate 131 (upper plate 144) and are arranged in a direction perpendicular to the longitudinal direction of the lower plate 131 (upper plate 144).
Further, the coil spring 139 is a tension spring, and always biases the front pin 1314 and the rear pin 1333 in a direction approaching each other, whereby the holding surface 1316 of the lower plate 131 and the clamping surface 1325 of the upper plate 144 are As long as no external force is applied, the contact state is always maintained.

  The drive means B is a drive source of the upper thread holding device 130, and a holding motor 134 as an actuator for switching the state of the thread clamp A, and a swing link fixedly mounted on the rotating shaft 1341 of the holding motor 134. 140, a connecting member 135 having one end connected to the swing end 1402 of the swing link 140 and the other end connected to the thread clamp A via a cam plate link 136, which will be described later, and the cam plate link 136. A guide 137 that holds the thread grip A that is held and guides the moving operation thereof, and a guide lid 138 that covers the thread grip A held by the guide 137 are provided.

  The holding motor 134 is a stepping motor that rotates by a predetermined angle in accordance with an operation command signal from the control device 120, and is driven at a specified main shaft angle according to a pulse signal based on the main shaft 32 angle output from the encoder 37. .

  The connecting member 135 is arranged along the Y direction in the figure, and a hole 1351 is formed at one end thereof, and a hole 1352 is formed at the other end. The connecting member 135 transmits the displacement in the Y direction at the swing end portion 1402 of the swing link 140 to the thread grip A via the cam plate link 136.

  The cam plate link 136 is arranged so as to cross the lower plate 131 (upper plate 144), and the longitudinal direction thereof is arranged along the X-axis direction in the drawing. The cam plate link 136 is provided with a cam plate pin 1361 that protrudes downward from the lower surface thereof. Therefore, the cam plate link 136 can swing around the cam plate pin 1361. The cam plate link 136 has a left hole 1362 at one end in the longitudinal direction and a right hole 1363 at the other end. A left pin 1315 of the lower plate 131 and a right pin 1334 of the upper plate 144 are connected to the left hole portion 1362 and the right hole portion 1363, respectively. Further, a cam shape portion 1364 that is slightly curved is provided at the left end portion of the cam plate link 136 so as to correspond to the outer peripheral surface of the roller 142 described later.

The guide 137 is fixed inside the sewing machine bed portion 21.
The guide 137 has a groove portion 1371 having a predetermined width at the center thereof along the front-rear direction, and the groove portion 1371 is formed with an intermediate hole portion 1372 along the front-rear direction. Further, slit-like left hole portions 1373 and right hole portions 1374 are respectively formed along the front-rear direction on both the left and right sides of the groove portion 1371 of the guide 137. Here, the left hole portion 1373 and the right hole portion 1374 are formed in parallel to each other, but the left hole portion 1373 and the right hole portion 1374 are in a slightly shifted positional relationship in the front-rear direction. The left hole 1373 is formed on the front side, and the right hole 1374 is formed on the rear side. A roller 142 is attached to the lower portion of the left edge of the guide 137 with a screw 1375.
The width of the groove portion 1371 is substantially the same as the width of the lower plate 131 and the upper plate 144.

  The guide lid 138 is a substantially flat plate-like member, and is fixed to the guide 137 at two positions on the front side and the rear side by four screws 1381. Thus, the lower plate 131 and the upper plate 144 described above are sandwiched between the guide 137 and the guide lid 138 and guided by the groove portion 1371 of the guide 137 to prevent the lower plate 131 and the upper plate 144 from rattling. To do.

  In the driving means B, a shaft portion 1401 that is one end portion of the swing link 140 is fixed to the rotation shaft 1341 of the holding motor 134. Then, the connecting member 135 is connected to the swing end 1402 of the swing link 140 by a step screw 141 inserted so as to be slidable in a hole 1351 formed at one end of the connecting member 135. . Further, the cam plate link 136 is attached to the hole portion 1352 formed in the other end portion of the connecting member 135 in a state where the cam plate link 136 is pivotally supported by the cam plate pin 1361. With such a configuration, the connecting member 135 moves back and forth along the Y-axis direction by the swing of the swing link 140 accompanying the rotation of the rotation shaft 1341 of the holding motor 134 within a predetermined angle range. The longitudinal movement of the connecting member 135 is transmitted to the cam plate link 136.

Further, a left pin 1315 of the lower plate 131 and a right pin 1334 of the upper plate 144 are inserted into the left hole portion 1373 and the right hole portion 1374 of the guide 137, respectively. The left pin 1315 and the right pin 1334 are The cam plate link 136 is attached by stoppers 143 and 143 so as to be slidable in the left hole portion 1362 and the right hole portion 1363, respectively.
Therefore, the driving force accompanying the rotation of the rotation shaft 1341 of the holding motor 134 is transmitted to the left pin 1315 and the right pin 1334 via the cam plate link 136. Since the left pin 1315 and the right pin 1334 are arranged so as to be movable back and forth by the left hole portion 1373 and the right hole portion 1374, respectively, the driving force thereof is lower plate 131 and upper plate 144 (thread gripping A ) Is moved to move back and forth relatively.

  The detection means C includes a first sensor 151 and a second sensor 151 that detect the presence or absence of the slit plate 150 fixed to the connecting member 135 and the slit plate 150 fixed to the inside of the sewing machine bed portion 21 and moving together with the connecting member 135. Sensor 152.

  The slit plate 150 is fixed to the connecting member 135 and is a member that moves back and forth together with the connecting member 135. The slit plate 150 enters and exits a position corresponding to the first sensor 151, and enters and exits a position corresponding to the first detected part 1501 where the presence or absence is detected by the first sensor 151 and the second sensor 152. , And a second detected portion 1502 whose presence or absence is detected by the second sensor 152.

Each of the first sensor 151 and the second sensor 152 includes light emitting elements 1511 and 1521 and light receiving elements 1512 and 1522. For example, an LED is used as the light emitting element and a photosensor is used as the light receiving element. In the following description, it is defined as an off state when the light receiving element receives light emitted from the light emitting element, and an on state when the light receiving element does not receive light emitted from the light emitting element.
Specifically, when the first detected part 1501 blocks the light emitted from the first sensor 151 as the slit plate 150 moves back and forth, the first sensor 151 detects the first detected part 1501 and turns it on. The first sensor 151 is turned off when it is in a state and is not shielded. Then, the first sensor 151 outputs a detection signal indicating whether it is in an on state or an off state to the control device 120.
Similarly, when the second detected portion 1502 blocks the light emitted from the second sensor 152, the second sensor 152 detects the second detected portion 1502 and is turned on, and when not blocked, the second sensor 152 is turned on. Is turned off. Then, the second sensor 152 outputs a detection signal indicating whether it is in an on state or an off state to the control device 120.
7, 9, and 10, an optical path 155 in which emitted light output from the light emitting element travels toward the light receiving element is indicated by a dotted line in the (A) plan view, and by a dot in the (B) side view.
In addition to the position detection by the combination of the light emitting element and the light receiving element, the detection means C may be provided with an encoder in the holding motor 134 and detect the position by detecting the angle of the encoder.

Next, the operation of the upper thread holding device 130 will be described.
First, with reference to FIG. 5, the operation from before the start of sewing to immediately after the start of sewing will be described.

  Based on the initial position signal from the control device 120, the holding motor 134 rotates the rotating shaft 1341 counterclockwise in the drawing at a predetermined angle. As the rotation shaft 1341 rotates, the swing link 140 swings around the shaft portion 1401 (see arrow L0 in FIG. 7A). Further, the connecting member 135 slidably attached to the swing link 140 by the step screw 141 moves (forwards) to the front side as the swing link 140 swings (arrow M0 in FIG. 7A). reference).

  The cam plate link 136 pivotally supported by the connecting member 135 moves forward as a whole as the connecting member 135 moves forward.

  The right pin 1334 of the upper plate 144 coupled to the right hole portion 1363 of the cam plate link 136 moves forward along the right hole portion 1374 of the guide 137 in accordance with the forward movement of the cam plate link 136, and the right hole portion. The front wall of 1374 collides (abuts), and the forward movement of the right pin 1334 is restricted. At this time, the upper plate 144 integrated with the right pin 1334 also moves forward, and the upper plate 144 is positioned at the foremost position.

  Similarly, the left pin 1315 of the lower plate 131 coupled to the left hole portion 1362 of the cam plate link 136 moves forward along the left hole portion 1373 of the guide 137 as the cam plate link 136 moves forward. At this time, since the left hole portion 1373 and the right hole portion 1374 of the guide 137 are formed relatively forward of the right hole portion 1374, the right pin 1334 of the upper plate 144 is Even after hitting (contacting) the front wall of the right hole portion 1374, the left pin 1315 of the lower plate 131 follows the left hole portion 1373 of the guide 137 so that the right pin 1334 of the upper plate 144 serves as a fulcrum. Move forward. The forward movement of the left pin 1315, that is, the forward movement of the lower plate 131 is continued until the through hole 1312 of the lower plate 131 reaches a predetermined frontmost position directly below the needle hole 161 of the needle plate 16. When the position is reached, the control device 120 stops by holding the holding motor 134. In addition, the front length of the left hole portion 1373 of the guide 137 is formed to have a margin so that the left pin 1315 does not collide with the front wall of the left hole portion 1373 even after reaching the foremost position. The step-out of the holding motor 134 is prevented.

  When the lower plate 131 and the upper plate 144 are positioned at the foremost position, the front pin 1314 of the lower plate 131 and the rear pin 1333 of the upper plate 144 are separated from each other in the Y-axis direction against the biasing force of the coil spring 139. It becomes. In this case, the front pin 1314 of the lower plate 131 and the rear pin 1333 of the upper plate 144 are urged toward each other in the front-rear direction by the urging force of the coil spring 139, but from the urging force of the coil spring 139. In addition, since the driving force of the holding motor 134 is larger, the lower plate 131 can be positioned at the foremost position against the urging force of the coil spring 139.

Further, when the lower plate 131 and the upper plate 144 are positioned at the foremost position, the holding surface 1316 in the through hole 1312 of the lower plate 131 and the clamping surface 1325 and the protrusion of the tip member 132 attached to the front end portion 1331 of the upper plate 144 The front end of the portion 1323 is separated in the Y-axis direction, and the through hole 1312 is open. At this time, the through hole 1312 and the needle hole 161 of the needle plate 16 overlap each other, and the sewing needle 11 of the first stitch after the start of sewing is connected to the through hole 1312 and the needle hole 161 of the needle plate 16. It will be possible to move up and down through. Thus, the position where the thread clamp A is positioned on the vertical movement path of the sewing needle 11 is referred to as an “initial position” in the following description. In this initial position, the thread clamp A is in a “released state” in which the upper thread is not held or pinched.
In this “initial position”, the slit plate 150 of the detecting means C is moved forward with the forward movement of the connecting member 135, and the first detected portion 1501 and the second detected portion 1502 of the slit plate 150 are The first sensor 151 and the second sensor 152 are in non-detection positions, respectively, and are in the off state.

  When the thread clamp A is at the “initial position”, the sewing needle 11 of the first stitch through which the end U0 on the sewing start side of the upper thread U is inserted passes through the needle hole 161 and the through hole 1312. Move up and down. The end U0 of the upper thread U is pulled downward by the blade tip of the horizontal hook of the hook mechanism when the sewing needle 11 is lowered, and then when the sewing needle 11 is raised, as shown in FIG. In a state where the end U0 of the upper thread U is inserted through 1312, the upper thread U hangs down.

  Next, with reference to FIG. 9, the operation of the upper thread holding device 130 after the start of sewing (after the first sewing needle 11 moves up and down) will be described.

  Based on the intermediate holding position signal from the control device 120, the holding motor 134 rotates the rotation shaft 1341 clockwise to a predetermined angle in the drawing. As the rotation shaft 1341 rotates, the swing link 140 swings about the shaft portion 1401 (see arrow L1 in FIG. 9A). Further, the connecting member 135 slidably fixed to the swing link 140 by the step screw 141 moves (rearly moves) to the rear side as the swing link 140 swings (the arrow in FIG. 9A). See M1).

  The cam plate link 136 that is pivotally supported by the connecting member 135 moves rearward as a whole as the connecting member 135 moves rearward.

  When the cam plate link 136 starts moving backward, first, the rear pin 1333 of the upper plate 144 is pulled in the direction of the front pin 1314 of the lower plate 131 by the biasing force of the coil spring 139. With the pin 1334 still in contact with the front wall of the right hole 1374 of the guide 137, only the lower plate 131 starts to move backward. When the lower plate 131 is moved by a predetermined amount and stopped, the holding surface 1316 of the lower plate 131 is positioned behind the tip of the protrusion 1323 of the upper plate 144, and the through hole 1312 is closed. "

This “intermediate holding position” is a state in which only the lower plate 131 is moving backward, the cam plate pin 1361 of the cam plate link 136, the right pin 1334 of the upper plate 144, and the left pin of the lower plate 131. Reference numeral 1315 denotes an arrangement until it is arranged in a line in a direction substantially perpendicular to the longitudinal direction of the thread clamp A (lower plate 131, upper plate 144). During this time, the holding motor 134 rotates at a predetermined angle corresponding to the “intermediate holding position”.
In this “intermediate holding position”, the slit plate 150 of the detecting means C is moved rearward with the rearward movement of the connecting member 135, and the first sensor 151 detects the first detected portion 1501 of the slit plate 150. In position and on. In addition, the second detected portion 1502 is in the non-detection position in the second sensor 152 and is in the off state.

The movement of the lower plate 131 from the “initial position” to the “intermediate holding position” is completed by the time the lift of the balance is started. In this “intermediate holding position”, the upper surface 131 and the holding surface 1316 of the lower plate 131 are moved upward. It is not in contact with the clamping surface 1325 of the plate 144, and the upper thread is not clamped or held. In this state, the upper thread U that the balance pulls upward is bent, and resistance to lifting of the upper thread U is given.
By imparting such resistance, it is possible to prevent the upper thread U pulled up by the balance from sagging due to inertial force, and to prevent the needle thread U from coming off from the thread grip A. The length from the hole to the end portion U0 of the sewing start of the upper thread U can be kept constant.

  Next, with reference to FIG. 10, the operation of the upper and lower thread holding device 130 before and after the thread gripper A clamps and holds the upper thread U after the “intermediate holding position” will be described.

The holding motor 134 rotates clockwise from the above-mentioned “intermediate holding position” to swing the swing link 140, and the cam is moved by the rearward movement of the connecting member 135 accompanying the swing of the swing link 140. The plate pin 1361, the right pin 1334, and the left pin 1315 are arranged in a row in a direction perpendicular to the longitudinal direction of the thread clamp A. In this state, the front pin 1314 of the lower plate 131 and the rear pin 1333 of the upper plate 144 are biased by the biasing force of the coil spring 139 so as to be closest to each other in the front-rear direction. Accordingly, the holding surface 1316 of the lower plate 131 and the clamping surface 1325 of the upper plate 144 come into contact (actually, since the upper thread U is interposed, the state becomes close to contact without contact), and FIG. As shown in FIG. 4, the thread grip A is the “upper thread clamping position” where the upper thread U is clamped. At this upper thread clamping position, the thread clamp A is in a “clamping state”.
In this upper thread holding position, the control device 120 executes the cutting of the sewing start end portion of the upper thread U by the thread trimming device 80 described above.

  After reaching the “upper thread clamping position”, the holding motor 134 continues to rotate the rotation shaft 1341 clockwise at a predetermined angle in the drawing based on the retraction position signal from the control device 120. As the rotation shaft 1341 rotates, the swing link 140 swings around the shaft portion 1401 (see arrow L2 in FIG. 10A). Further, the connecting member 135 slidably fixed to the swing link 140 by the step screw 141 moves (rearly moves) rearward as the swing link 140 swings (the arrow in FIG. 10A). M2).

Next, based on the release position signal from the control device 120, the holding motor 134 rotates the rotation shaft 1341 clockwise to a predetermined angle in the drawing. As the rotation shaft 1341 rotates, the cam plate link 136 moves rearward.
At this time, the left pin 1315 of the cam plate link 136 moves rearwardly along the left hole portion 1373 of the guide 137 with the rear movement of the cam plate link 136 and comes into contact with the rear wall of the left hole portion 1373. The rear movement of 1315 is restricted.
Similarly, the right pin 1334 moves backward along the right hole 1374 of the guide 137, and after the left pin 1315 contacts the rear wall of the left hole 1373, only the right pin 1334 moves and moves downward. The plate 131 and the upper plate 144 are separated from each other in the front-rear direction, and the through hole 1312 is opened. At this time, the through hole 1312 is located behind the needle hole 161 of the needle plate 16.
Then, the through hole 1312 is opened and the thread clamp A is released. The position where the thread grip A is in the open state is referred to as “release position”. As described above, since the control device 120 cuts the sewing start end of the upper thread U at the upper thread holding position, the thread gripper A uses the sewing start end U1 of the excised upper thread U. Although it is in the held state, it becomes possible to release the sewing start end U1 of the cut upper thread U and remove it from the thread grip A by entering the released state.

  As described above, the upper thread holding device 130 can switch between the clamping state and the releasing state of the end portion U0 of the upper thread U at the start of sewing by the forward / backward movement operation.

[Suction mechanism]
The suction mechanism 110 includes a suction nozzle (not shown) disposed below the thread grip A of the upper thread holding device 130 in the release position in the sewing bed portion 21 and a suction pump 114 for making the suction nozzle negative pressure. (See FIG. 3) and a dust collection trap that collects the sewing start end of the upper thread U after excision sucked from the suction nozzle.
With this configuration, after cutting the sewing start end of the upper thread U, the sewing start end U1 of the upper thread U cut from the thread grip A moved to the release position can be sucked and collected in the dust trap. .

[Residual edge excision mechanism]
As shown in FIG. 2, the remaining end excision mechanism 100 is provided at two openings in the work table 14. Each remaining end cutting mechanism 100 has a remaining end on the back surface of the fabric after the sewing start end of the upper thread U is cut by the thread trimming device 80 and the sewing end ends of the upper thread U and the lower thread D are cut. In some cases, this is to cut it shorter.
Each remaining end excision mechanism 100 has a moving knife and a fixed knife arranged so as to be movable up and down in the opening of the work table 14, and a moving air cylinder 102 (see FIG. 3) for moving the moving knife and the fixed knife up and down. And a thread cutting air cylinder 103 (see FIG. 3) that performs a cutting operation with a knife.
The remaining end excision mechanism 100 normally stands by at a position lower than the upper surface of the work table 14 so as not to hinder sewing. When the remaining end is excised, the feed mechanism 60 is used to remove the cloth. The sewing start end portion or the sewing end end portion can be conveyed to the opening portion, and the moving knife and the fixed knife can be raised to the vicinity of the upper surface of the work table 14 to cut off the remaining end.
Since the remaining end excision mechanism 100 is provided in two on both sides of the needle drop position, the control device 120 has the remaining end excision mechanism closer to the sewing start end or the sewing end end of the fabric at the final needle. 100 is selected and conveyed, and the remaining edge processing is performed.

[Sewing machine control system]
As shown in FIG. 3, the control device 120 includes a ROM 122 that stores and stores various control programs, a CPU 121 that performs various arithmetic processes according to these various programs, and a RAM 123 that is used as a work memory in the various processes. , And an EEPROM 124 storing various sewing data and setting data.
The control device 120 is connected to the sewing machine motor 31 and the encoder 37 of the needle up-and-down moving mechanism 30, the X-axis motor 65 of the feeding mechanism 60, the Y-axis motor 66, and the lifting / lowering via a system bus, an interface and a drive circuit (not shown). Motor 64, thread trimming motor 83 of thread trimming device 80, air cylinder 102 for raising and lowering remaining end cutting mechanism 100 and air cylinder 103 for thread trimming, suction pump 114 of suction mechanism 110, and motor for holding upper thread holding device 130 134, the first sensor 151, the second sensor 152, and the like are connected.
Note that the control device 120 controls the lifting / lowering air cylinder 102 and the thread cutting air cylinder 103 in practice for the solenoid valves that operate them, but the illustration of each solenoid valve is omitted here.

Further, the control device 120 is connected to an operation input unit 125 for inputting various settings related to sewing and a pedal 126 as signal input means for executing sewing.
In the operation input unit 125, for example, various commands such as the number of stitches in the sewing pattern data, the needle drop position, and whether or not the remaining end process is executed are set.
The pedal 126 inputs an instruction to start sewing when the pedal 126 is depressed.

[Thread cutting control during sewing]
The thread cutting control performed by the control device 120 during sewing will be described with reference to the operation explanatory diagrams of FIGS. 12 to 14 and the flowchart of FIG. 15.
The sewing operation of the sewing machine 10 reads the sewing pattern data and moves the cloth presser 63 to a needle drop position corresponding to the sewing pattern for each stitch to perform operation control for forming a stitch according to a predetermined sewing pattern.
Here, the control of the cutting operation of the upper thread U and the lower thread D executed from the start to the end of the sewing will be mainly described.

First, when a sewing start instruction is input by the pedal 126, the CPU 121 drives the thread trimming motor 83 to position the moving knife 81 at the position P3 (step S1), and drives the holding motor 134 to thread. The grip A is moved to the initial position (step S3, FIG. 12).
As a result, the moving knife 81 has the through hole 814 below the needle hole 161 and can cause the first hole to be dropped in the through hole 814.
In addition, the thread grip A is positioned below the needle hole 161 in the opened state, and the needle drop of the first stitch to the through hole 1312 can be performed.

  Then, the driving of the sewing machine motor 31 is started (step S5), and the first needle drop is performed on the through hole 814 of the moving knife 81 and the through hole 1312 of the thread clamp A. Further, the sewing needle 11 temporarily forms a loop of the upper thread U below the fabric K. When the sewing needle 11 is caught by the sword tip of the horizontal hook, the tip end of the sewing start end of the upper thread U is a moving knife. It passes through the through-hole 814 of 81 and the through-hole 1312 of the thread clamp A, and is pulled out to the lower side of the fabric K and is in a suspended state. Therefore, the loop of the upper thread U disappears and no knot with the lower thread D is not formed at the first needle drop position.

  Next, the CPU 121 obtains the spindle angle from the output of the encoder 37, and determines whether or not the sewing needle 11 that has dropped the first stitch has risen above the needle plate 16 (step S7). For example, when the main shaft angle is 0 ° when the sewing needle 11 is at the top dead center, it is determined whether or not the main shaft angle has reached 270 °.

The CPU 102 continues monitoring until the main shaft angle is reached, and when it reaches, the thread grip A is moved to the intermediate holding position by driving the holding motor 134 (step S9).
As a result, the upper thread U is gently held by the thread clamp A, and sliding resistance is given to the lifting of the balance.

  Further, the feed mechanism 60 moves the cloth presser 63 to the next needle drop position, and the CPU 121 prevents the second needle drop from being performed on the through hole 814 of the moving knife 81 and yet the sewing needle 11. The moving knife 81 is moved to the position P2 so as not to interfere with the moving knife 81 (step S11, FIG. 13). Thus, the sewing start end portion of the upper thread U is gently held by the thread grip A through the needle hole 161 and the through hole 814 of the moving knife 81.

  Further, the CPU 121 moves the thread clamp A to the upper thread clamping position at a spindle angle that becomes the top dead center of the balance (step S13). Thereby, the sewing start end portion of the upper thread U is held by the thread grip A.

Next, the CPU 121 determines whether or not the sewing needle 11 that has dropped the second stitch has risen above the needle plate 16 (step S15). Then, the CPU 102 continues monitoring until the sewing needle 11 reaches the spindle angle that is above the needle plate 16, and when it reaches, the moving knife 81 is moved to the position P1 (step S17, FIG. 14).
As a result, the sewing start end of the upper thread U that has been inserted into the through hole 814 of the moving knife 81 is cut in cooperation with the fixed knife 82.

Then, the CPU 121 moves the thread clamp A to the release position (step S19). As a result, the thread clamp A has the through-hole 1312 greatly opened, and the sewing start end U1 of the upper thread U that has been cut off is released from the held state.
Then, the CPU 121 operates the suction pump 114 of the suction mechanism 110 to suck and collect the sewing start end portion U1 of the cut upper thread U from the nozzle (step S21).

Thereafter, the sewing machine 10 forms a sewing pattern according to the sewing pattern data. Then, the CPU 121 determines whether or not the needle drop of the final needle set in the sewing pattern data has been completed and the sewing needle 11 has reached the spindle angle above the needle plate 16 (step S23).
When the spindle angle reaches a predetermined position, the CPU 121 performs an operation of moving the moving knife 81 located at the position P1 forward and rotated to the position P4 and then returning it to the position P1 by reverse rotation (step S25).
As a result, the cloth side portion of the upper end of the upper thread U that hangs down from the needle hole 161 and the end of the lower end of the lower thread D are selected and cut.

Then, the CPU 121 stops the driving of the sewing machine motor 31 (step S27).
Further, it is determined whether or not the remaining pattern cutting is set to be executed in the sewing pattern data (step S29). If execution is not set, the sewing is finished as it is.
On the other hand, when execution of the remaining end excision is set, the feed mechanism 60 moves the sewing start position and the sewing end position of the fabric K to the position immediately above the remaining end excision mechanism 100 in order and for lifting and lowering. The air cylinder 102 and the yarn cutting air cylinder 103 are operated to cut off the remaining end of the upper thread U at the sewing start position and cut off the remaining ends of the upper thread U and the lower thread D at the sewing end position (step S31). ).
Then, the sewing is finished.

[Technical effects of the embodiment of the invention]
The sewing machine 10 controls the upper thread holding device 130 so that the control device 120 performs the holding operation of the sewing start end portion of the upper thread U after the first needle drop and before the second needle drop. Since the thread trimming device 80 is controlled so that the sewing start end of the upper thread U is cut after the needle drop, the sewing start end of the shortened upper thread U after the cutting is the first needle in the fabric K. It is possible to shorten the sewing start end portion of the upper thread U generated in the fabric K while avoiding coming off from the fall position. As a result, the sewing quality can be improved.
In addition, since the sewing start end of the upper thread U is cut after the second stitch, the sewing start end of the upper thread U can be prevented from being sewn into the seam, and the sewing quality can be improved. It becomes possible.

In the sewing machine 10, the thread trimming device 80 cuts the sewing end of the upper thread U and the lower thread D in cooperation with the moving knife 81 that performs a reciprocating operation including forward movement and backward movement, and the moving knife 81. The moving knife 81 is provided with a fixed knife 82 and a thread trimming motor 83 that applies a reciprocating motion to the moving knife 81. The moving knife 81 is a portion on the fabric side of the upper thread U and a portion on the sewing needle side of the lower thread D and the upper thread when moving forward. The control device 120 moves the blade portion 812 of the moving knife 81 forward of the needle hole 161 before the needle drop of the first stitch. The thread trimming motor 83 is controlled so as to wait on the downstream side (position P3) and to move the blade portion 812 of the moving knife 81 backward to the fixed knife 82 (moving to the position P2) after the second needle drop.
Thereby, the sewing start end of the upper thread can also be cut by the thread trimming device 80 for cutting the sewing end ends of the upper thread U and the lower thread D, and the configuration of the apparatus can be reduced. It becomes possible to reduce the manufacturing cost of the sewing machine.
In addition, it is possible to use the existing thread trimming device of the sewing machine as it is or with a minimum modification to cut the sewing thread start end.

  Further, the moving knife 81 of the thread trimming device 80 has a through hole 814 in which the blade portion 812 is formed at the opening edge, and the control device 120 has the through hole 814 and the needle hole 161 before the needle drop of the first stitch. Since the thread trimming motor 83 is controlled so that the moving knife 81 waits at the position P3 where the needle thread overlaps, the sewing start end of the upper thread U can be held inside the through-hole 814 in advance, and more reliably. It is possible to cut the sewing start end.

  In addition, the sewing machine 10 cuts off the ends of the upper thread U and the lower thread D that are provided around the needle plate 16 and move around the needle plate 16 along the upper surface of the needle plate 16 and hang from the fabric K. Since the cloth K is conveyed to the remaining end cutting mechanism 100 by the feed mechanism 60 after sewing, the sewing start end portion of the upper thread U shortened by cutting by the thread trimming device 80 is provided. Further, cutting can be performed, and the sewing start end portion of the upper thread can be further shortened.

  Further, since the sewing machine 10 includes the suction mechanism 110 that collects the sewing start end portion of the upper thread U cut from the fabric K, the processing operation of the sewing start end portion U1 of the cut upper thread U is not required. Therefore, it is possible to increase the efficiency of the sewing work.

[Other examples of upper thread holding device]
Other examples of the upper thread holding device are shown in FIGS. This upper thread holding device 130A differs from the upper thread holding device 130 described above only in the structure of the tip portion of the lower plate 131, and the other parts and other members are the same as the upper thread holding device 130. Therefore, the same parts are denoted by the same reference numerals and the description thereof is omitted, and only different parts are described.

  A lower plate 131A of the upper thread holding device 130A has a U-shaped portion opened toward the front (the needle vertical movement path side) instead of the rectangular through hole 1312 extending along the Y-axis direction at the front end portion thereof. 1312A is formed, and an opening / closing plate 171A as an opening / closing body capable of closing the open end of the U-shaped portion 1312A is provided at the front end of the lower plate 131A. The remaining structure of the lower plate 131A is the same as that of the lower plate 131.

The opening / closing plate 171A is a substantially U-shaped rotating member with the opening portion directed leftward, and is supported by the lower plate 131A so as to be rotatable about the Z axis by a step screw 172A at the right rear end thereof. Yes. The open / close plate 171A is provided with an open / close arm 1711A extending leftward at a front end portion thereof and an input arm 1712A extending leftward at a rear end portion thereof.
Both the open / close arm 1711A and the input arm 1712A can be rotated integrally back and forth around the step screw 172A, and the input arm 1712A is stretched between the lower thread 131A at the rotating end portion. The rear turning force is input by the tension of the spring 173A. Accordingly, the backward turning force is simultaneously input to the opening / closing arm 1711A.

  The open / close arm 1711A is disposed so as to close the opened front portion of the U-shaped portion 1312A, and when the thread clamp A is in the initial position, the U-shaped portion 1312A is received by the tension of the spring 173A. The closed position is maintained. When the thread clamp A is in the initial position, a rectangular frame in which the U-shaped portion 1312A of the lower plate 131A and the open / close arm 1711A of the open / close plate 171A surround the sewing needle 11 when lowered (bottom dead center). Shape. That is, the U-shaped portion 1312A and the opening / closing body 171A constitute a yarn catching portion.

Further, the opening / closing arm 1711A has a rear end surface of the opening / closing arm 1711A that is far away from the clamping surface 1325 of the tip member 132 when the thread clamp A is in the initial position, and the rear end surface of the opening / closing arm 1711A is the tip member in the intermediate holding position. It approaches to the clamping surface 1325 of 132 through a slight gap. That is, in this state, the upper thread U that is lifted upward by the balance is bent, and resistance to the upper thread U is pulled up.
Further, the open / close arm 1711A has a state in which the rear end surface of the open / close arm 1711A is in contact with or closer to the holding surface 1325 of the tip member 132 and the upper thread U can be held when the thread grip A is in the upper thread holding position. Become.

Further, the input arm 1712A of the opening / closing plate 171A is provided with a protrusion 1713A that abuts on the front end portion of the guide 137 by the backward movement of the lower plate 131A when the thread grip A moves from the upper thread clamping position to the release position. The opening / closing arm 1711A and the input arm 1712A of the opening / closing plate 171A are rotated forward by the contact of the projection 1713A (see FIGS. 17 and 18).
As a result, the open / close arm 1711A of the open / close plate 171A that has closed the U-shaped portion 1312A of the lower plate 131A opens the U-shaped portion 1312A.

  The operation control to the upper thread holding device 130A by the control device 120 is the same as the operation control to the upper thread holding device 130 described above. That is, the holding motor 134 is controlled in the same manner at the same timing under the same conditions based on the detections of the sensors 151 and 152.

Thus, the upper thread holding device 130A forms a U-shaped portion 1312A instead of the through-hole 1312 in the lower plate 131A, is closed by the opening / closing plate 171A to form a frame shape, and when released, the opening / closing plate 171A rotates forward. Thus, control is performed to open the front of the U-shaped portion 1312A.
When the upper thread U is entangled with the front portion of the through hole 1312, the lower plate 131 having the through hole 1312 is continuous with the periphery of the through hole 1312. However, the upper thread holding device 130A is in an open state in which the opening / closing plate 171A is separated from the U-shaped portion 1312A on the lower plate 131A, so that the upper thread U of the entangled upper thread U can be removed. The sewing start end U1 is easily detached from the opening / closing arm 1711A, and the sewing start end U1 of the cut upper thread U can be sucked more reliably.

[Others]
In the present embodiment, the electronic cycle sewing machine has been exemplified. However, the present invention is not limited to this, and the control for cutting the sewing start end portion of the upper thread U can be applied to other types of sewing machines having a thread trimming device. is there.

Moreover, although the thing provided with the horizontal hook was illustrated as the hook mechanism 50, the kind of hook other than that may be sufficient.
Further, the thread trimmer 80 is exemplified by the moving knife 81 rotating about the vertical axis, but is not limited thereto, and the thread trimmer includes a linear moving knife and a moving knife rotating around the horizontal axis. Even in the case of the apparatus, it is possible to apply the control for cutting the sewing start end of the upper thread U.

DESCRIPTION OF SYMBOLS 10 Sewing machine 11 Sewing needle 12 Needle bar 131A Lower plate 1312A U-shaped part 171A Opening / closing body 1711A Opening / closing arm 1713A Protrusion part 14 Worktable 16 Needle plate 161 Needle hole 20 Sewing frame 30 Needle up-and-down moving mechanism 31 Sewing motor 50 Hook mechanism 60 Feed Mechanism 63 Cloth presser 80 Thread trimming device 81 Moving knife 811 Threading portion 812 Blade portion 813 Capture portion 814 Through hole 82 Fixed knife 83 Thread trimming motor (actuator)
DESCRIPTION OF SYMBOLS 100 Remaining end cutting mechanism 110 Suction mechanism 120 Control apparatus 130 Upper thread holding | maintenance apparatus K Cloth (sewing thing)
D Lower thread P1 to P4 Position U Upper thread

Claims (5)

A needle plate in which a needle hole into which a sewing needle is inserted is formed;
A needle up-and-down movement mechanism for moving up and down the sewing needle;
A hook mechanism that captures the upper thread from the sewing needle below the needle plate and entangles the lower thread,
A thread trimmer provided between the needle plate and the shuttle mechanism, and for cutting an upper thread by a cutting operation of a moving knife;
An upper thread holding device which is provided between the thread trimming device and the shuttle mechanism and holds a sewing start end of the upper thread;
In a sewing machine comprising:
Controlling the upper thread holding device so as to perform the holding operation of the sewing start end of the upper thread after the first needle drop and before the second needle drop,
A control device for controlling the thread trimming device so as to cut a sewing start end of the upper thread after a second needle drop ;
The thread trimming device includes a moving knife that performs a reciprocating operation including forward and backward movements, a fixed knife that cuts the sewing end ends of the upper thread and the lower thread in cooperation with the moving knife, and a reciprocating operation to the moving knife. With actuator to give
The moving knife has a threading part that sorts the cutting part of the upper thread and the lower thread and the non-cutting part of the upper thread when moving forward, and a blade part that performs cutting when moving backward,
The control device waits the blade portion of the moving knife on the downstream side in the forward direction from the needle hole before the needle drop of the first needle, and moves the blade portion of the moving knife to the fixed knife after the needle drop of the second stitch A sewing machine that controls the actuator to move backward . The moving knife has a through hole in which the blade portion is formed at an opening edge portion,
2. The sewing machine according to claim 1 , wherein the control device controls the actuator so that the moving knife waits at a position where the through hole and the needle hole overlap before the needle drop of the first stitch. . A moving mechanism for moving the workpiece along the upper surface of the needle plate;
A remaining end excision mechanism provided on the needle plate or around the needle plate and excising an end of an upper thread that hangs down from the sewing product;
The control device is configured to move a sewing start end portion of the upper thread or a sewing end end portion of the upper thread of the sewing product to the remaining end excision mechanism, and to execute a cutting operation by the remaining end excision mechanism. The sewing machine according to claim 1 or 2 , wherein The sewing machine according to any one of claims 1 to 3 , further comprising a suction mechanism that collects a sewing start end portion of the upper thread cut from the workpiece. The upper thread holding device is
The sewing needle at the time of lowering is loosely inserted, and includes a thread catching portion formed in a frame shape for surrounding the periphery of the sewing needle at the time of lowering,
The thread catching portion surrounds the periphery of the sewing needle by a U-shaped portion having an opening directed to the vertical movement path of the sewing needle and an opening / closing body capable of opening and closing the opening of the U-shaped portion. It has a frame shape,
The thread catcher holds the sewing thread start end of the upper thread inside the U-shaped part,
The control device is configured to disengage the upper thread holding device so as to open the opening of the U-shaped portion closed by the opening / closing body after the sewing start end portion of the upper thread is cut by the thread trimming device. The sewing machine according to any one of claims 1 to 4 , wherein the sewing machine is controlled.

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