KR20080045071A - Sewing machine - Google Patents

Abstract

A sewing machine is provided to hold a sewing initiation end portion of an upper thread by an upper thread-holding unit until the last needle is dropped, thereby preventing the upper thread from being bound with stitches of a lower thread. An upper thread-holding unit holds a sewing initiation end portion of an upper thread below a needle plate(108). A bobbin unit(120) binds the upper thread and a lower thread with each other below the needle plate. A thread-cutting unit(130) cuts the upper thread and the lower thread between the needle plate and the bobbin unit. The upper thread-holding unit is moved along a lower surface of the needle plate between a needle lower position, which is on a passage line of a sewing needle(104), and a standby position, which is away from the needle lower position. The upper thread-holding unit is in a released state at the needle lower position. A thread-holding unit is in a holding state between a mid-position and the standby position, wherein the mid-position is defined on the way from the needle lower position toward the standby position. An operation controller moves the thread-holding unit to the standby position when a needle of a first stitch is dropped, and moves the thread-holding unit to the mid-position when the last needle is dropped. The operation controller moves the thread-holding unit to the mid-position at the cutting time, thereby cutting the sewing initiation end portion of the upper thread.

Description

Sewing machine {SEWING MACHINE}

This invention relates to the sewing machine provided with the upper thread holding | maintenance apparatus holding the sewing start end of an upper thread below a needle plate.

In a conventional sewing machine, the sewing starting end of the upper thread inserted into the sewing needle is maintained on the back side of the fabric so that the sewing starting end of the upper thread is maintained on the lower side of the needle plate so that the needle stitch is properly formed from the initial needle stitch. An upper thread holding device is provided (see Patent Document 1, for example).

In such a sewing machine, when the sewing is started, the knife tip of the bobbin catches the upper thread from the sewing needle of the first needle stitch, pulls the sewing start end to the lower side of the needle plate, and holds the sewing start end thread of the upper thread holding device. The ball is held, and the seal holder moves to the rear side (standing body part side) and waits. When the needle stitches are stabilized by the needle drop of several needles, the sewing start end is released. This prevents the sewing start end of the upper thread from falling off from the back side of the fabric, thereby making it possible to form needle stitches appropriately from the initial needle stitches.

[Patent Document 1] Japanese Patent Laid-Open No. 2000-279666

However, in order to cut the upper thread and the lower thread passing between the needle hole of the needle plate and the bobbin mechanism at the end of sewing, the movable scalpel rotates to cut the needle shanghai path at the lower side of the needle plate to capture the upper thread and the lower thread. In the sewing machine provided with the thread cutting tool to cut | disconnect, when providing the above-mentioned upper thread holding | maintenance apparatus, the following problem occurred at the time of button sealing.

That is, at the time of sealing of a button having two holes, a plurality of needles penetrate through two holes alternately (needle drop), and after completion of the final needle penetration, the thread cutting tool passes between the needle plate and the bobbin case. Cutting of the upper and lower threads. In the case of a button having four holes, the above operation is repeated for every two holes, or after every two holes, the thread is cut.

As described above, at the time of sewing the button which alternately penetrates the needles between the two holes to form a plurality of needle stitches, the sewing start end of the upper thread held by the upper thread holding device is after several needles from the start of sewing. Since the state becomes free and slack, it is wound several times on the bobbin thread passing between the two holes, and the small loops are entangled with each other, so that the sewing quality, that is, the quality of the sewing product, is reduced.

On the other hand, the sewing may be finished in the state stretched by the length of the thread holder without being entangled in the lower thread, and the button is not sewed securely, and it is necessary to sew again, which reduces work efficiency or Traces of the needle penetrating the sewing clothes, etc. remained, causing a decrease in sewing quality.

An object of the present invention is to improve sewing quality or work efficiency by reliably and neatly finishing needle stitch formation at the start of sewing at the time of button sealing.

Invention of Claim 1 is the upper thread holding apparatus 10 which can switch holding | maintenance and release | release of the sewing start end of an upper thread in the lower side of the needle board 108, and below the needle hole 108a of the said needle board. A bobbin mechanism 120 for capturing the upper thread and binding the lower thread, and a thread cutter tool 130 for cutting the upper thread and the lower thread passing between the needle hole of the needle plate and the bobbin mechanism, and at least two button holes. A sewing machine for sewing a button to an object to be sewn by alternately dropping a needle on the sewing machine, wherein the upper thread holding device is arranged between the needle lower position on the passage line of the sewing needle and the standby position away from the needle lower end. It can move along the lower surface of the needle plate, and is released from the lower needle level, from the predetermined intermediate position to the standby position on the way from the lower needle level to the standby position. The thread holder 20 which becomes a holding state between is provided, The said thread holder is made into the needle lower value at the time of the needle needle drop of the needle start of sewing start, and after that, at least at the last needle fall, Operation control means (80) for cutting the sewing start end of the upper thread by holding the retainer at the standby position, moving the thread retainer from the standby position to the intermediate position after the last needle drop, and then operating a thread cutter; It characterized by having a.

The invention according to claim 2 has the same configuration as the invention according to claim 1, and the operation control means is configured to move the thread cutter tool while maintaining the thread holder at the standby position after the final needle drop is completed. And the upper thread and the lower thread passing between the needle hole of the needle plate and the bobbin mechanism of the needle plate, and then, the thread holder is moved to the intermediate position to cut the sewing start end of the upper thread. .

The invention according to claim 3 has the same constitution as that of the invention according to claim 1, and the operation control means includes the needle hole of the needle plate by one operation of the thread cutting tool after the final needle drop is completed. It is characterized in that the upper and lower threads passing between the bobbin mechanism and the sewing start end of the upper thread.

The invention according to claim 4 has the same configuration as the invention according to any one of claims 1 to 3, and also holds and moves the sewing object to which button sealing is made, and the needle to drop the sewing needle at a predetermined position. Moving mechanisms (83, 84, 140), and the operation control means, if the initial needle dropping position and the final needle dropping position do not coincide, after the last needle dropping, the thread holder is moved to the intermediate position; Before moving, it characterized in that for controlling the movement mechanism to position the sewing object to the first needle drop position with respect to the sewing needle.

In the invention according to claim 1, since the sewing start end is held in the upper thread holding device until the final needle drop, the occurrence of a thread knot condition is effectively reduced by winding the needle stitches of the lower thread as in the case of being released in the middle.

Then, the thread cutting tool is operated after the thread holder is moved a predetermined distance from the standby position toward the needle lower tooth side after the last needle drop, so that the upper thread in the state extending from the needle hole toward the thread holder is relaxed. Since it is in the state which fell slightly below the needle hole, the thread cutting tool can cut the sewing start end part similarly to the case of cutting the thread passing between the needle hole and the bobbin case. In addition, at this time, since the upper thread holding device does not release the sewing start end of the upper thread, unlike the case of cutting the stretched thread in a free state, the thread cutting tool can perform the cutting satisfactorily.

Thereby, the thread remaining in the to-be-sealed thing after sewing can be shortened, and the sewing quality can be improved. In addition, it is not necessary to post-treat the yarn remaining after sewing, thereby improving productivity. Furthermore, no thread cutting dedicated to cutting the remaining thread is required, so that the cost in the sewing operation can be reduced.

In the invention according to claim 2, since the upper thread and the lower thread passing between the bobbin mechanism and the sewing start end of the upper thread are cut after the final needle drop is completed, the burden on the thread cutting device as compared with the case where the cutting is performed together It is possible to reduce the pressure and cut more reliably.

In the invention according to claim 3, since the upper thread and the lower thread passing between the sewing start end of the upper thread and the bobbin mechanism after the final needle drop completion are cut at the same time, the cutting time of each thread can be shortened.

In the invention according to claim 4, the motion control means moves the thread holder to the intermediate position after the initial needle drop position is aligned with the sewing needle when the initial needle drop position does not coincide with the final needle drop position. The position at the root of the sewing target side of the sewing start end of the upper thread can be made close to the needle hole of the needle plate. Accordingly, when the thread holder is moved to the intermediate position, the sewing start end of the upper thread can be further relaxed, and the sewing start end of the upper thread can be more surely cut by the thread cutting tool. In addition, it becomes possible to further shorten the sewing start end of the upper thread remaining on the sewing object side after cutting.

(Overall schematic configuration of sewing machine)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail based on FIG. The sewing machine 100 according to the present embodiment moves the button and the cloth relative to the sewing needle in accordance with a predetermined sewing pattern stored in the memory, thereby realizing the needle drop of the set number of times in each hole of the button.

1 is an overall view showing an outline of a sewing machine 100 according to an embodiment of the present invention. The sewing machine 100, the outline of the sewing machine bed 101 is located at its lower portion, the sewing machine standing body portion 102 raised upward from one end of the sewing machine bed 101, sewing machine standing body It is comprised by the sewing machine arm 103 provided in order to follow the sewing machine bed 101 from the upper part of the part 102. As shown in FIG. In addition, the sewing machine 100 corresponds to a so-called cylinder bed sewing machine in which the front end portion of the sewing machine bed 101 is formed in a substantially cylindrical shape and at the same time the width of the X-axis direction described later is narrower than other portions.

In addition, in explaining the structure of the sewing machine 100, the up-and-down movement direction of the sewing needle 104 mentioned later is made into the Z-axis direction, and as a direction orthogonal to this, of the sewing machine bed 101 and the sewing machine arm 103 is shown. The longitudinal direction is referred to as the Y-axis direction, and the direction orthogonal to both the Z-axis direction and the Y-axis direction is referred to as the X-axis direction. In addition, when the sewing machine 100 is installed on a horizontal plane, the + side in the Z-axis direction is up and the-side is in the bottom, the + side in the X-axis direction is right, the-side is left, and the Y-axis direction. Express the + side of Ess front and the-side back.

The sewing machine 100 is provided at the distal end of the sewing machine arm 103 and is provided on the sewing needle 104 reciprocating in the vertical direction by the sewing machine motor 105 and the upper portion of the sewing machine arm 103. Thread tension adjusting device for inserting the upper thread (not shown) for supplying the upper thread to the 104 and the upper thread with a predetermined load between the upper thread supply source and the sewing needle 104 to generate a resistance to movement in the conveying direction ( 106, a thread take-up device for pulling up the upper thread by thread take-up 107 at a predetermined timing between the thread tension adjusting device 106 and the sewing needle 104, and an upper surface of the sewing machine bed 101. And a needle plate 108 formed with a needle hole 108a for inserting the tip end of the sewing needle 104, and installed below the needle plate 108 in the sewing machine bed 101, and the sewing is lowered. While engaging the upper thread loop from the needle 104, A bobbin mechanism 120 for inserting the thread, and an upper thread holding device 10 for maintaining the upper thread end portion at the time of the first needle stitching of the sewing needle 104 between the needle plate 108 and the bobbin mechanism 120; It is installed in the sewing machine bed 101, thread sewing tool 130 for cutting the upper thread and the lower thread passing between the needle hole 108a of the needle plate 108 and the bobbin mechanism 120 after sewing, and cloth and buttons A cloth holding mechanism 140 for holding and giving a movement to the sewing needle, a thread removing mechanism not shown for removing the upper thread cut above the fabric, and an operation control means for controlling the operation of each of the components. ).

The sewing needle 104 has a thread through hole formed near the tip end (lower end) thereof, and an upper thread is inserted through the thread through hole. In addition, the sewing needle 104 is supported at the lower end of the needle bar (104a), the needle bar (104a) is given by converting the rotational driving force from the sewing machine motor 105 by the crank mechanism (not shown) converted to the up and down reciprocating driving force Then, the reciprocating shangdong is performed at a predetermined cycle. The sewing machine motor 105 is provided with an encoder 109 (refer to FIG. 8) for detecting the rotation angle thereof, and the current sewing machine motor 105 is set to 0 ° when the sewing needle 104 is at the top dead center position. ) Outputs to the motion control means 80 which one of the angles is 0 to 360 degrees.

The thread take-up unit 107 is provided with an upper thread insertion hole (not shown), and moves up and down in a state where the upper thread is inserted, thereby pulling up the upper thread inserted into the sewing needle 104 at the time of its rise. In addition, the thread take-up device moves the thread take-up 107 up and down at the same period as the sewing needle 104, the timing that the thread take-up 107 reaches the top dead center, the sewing needle 104 reaches the top dead center. It is set slightly later than the timing.

The thread tension adjusting device 106 is provided with a thread tension solenoid 86 (see Fig. 18) for controlling the thread tension by changing the thread tension adjusting tray for threading the upper thread and the thrust for threading the thread. This thread tension solenoid 86 has its thrust controlled by the operation control means 80.

(Kitchen collection)

As shown in Fig. 3, the drum mechanism 120 is a reciprocating half-rotation, and a medium drum case 122 for capturing a loop of the upper thread by a knife tip 121 protruding along the rotational circumferential direction; , A large drum house 123 rotatably supporting the medium drum house 122, an upper thread guide plate 124 installed on the upper side of the large house house 123, and a sewing machine bed from the sewing machine standing body side toward the large house house 123. It has a drum axis 125 extending parallel to the longitudinal direction of the imparted reciprocating half-rotation driving force to the medium drum 122 through a driver (not shown).

As shown in FIG. 8, the middle drum 122 has a rail-shaped protrusion structure 126 formed over its outer circumference so as to repeat a half rotation, and large drums 123 on both sides of the protrusion structure 126. Race surfaces 127 and 128 in sliding contact with the support grooves 123a of the upper and lower surfaces are formed. Moreover, the knife tip 121 is formed in the edge part of the circumferential direction of the said rail-shaped protruding structure 126, and guides of the upper thread guide plate 124 by the one half rotation operation of the medium drum case 122. As shown in FIG. The loop of the upper thread is hooked by passing right next to the thread passage hole of the sewing needle 104 invading from the hole. Accordingly, the knife tip 121 is formed in a shape in which the tip thereof is biased in one direction L along the rotation center line of the medium drum case 122, and the knife tip 121 and the protruding structure 126 are , The sewing needle 104 is disposed on the other direction (R) side along the rotation center line with respect to the shank east path (N).

Further, the bobbin shaft 125 is located on the R side with respect to the medium bobbin 122 (hereinafter, the direction R side is referred to as the bobbin shaft side), and is not directly connected to the medium bobbin 122, but the medium bobbin 122 ) And the driving force of the reciprocating half-rotation to the medium-sized book house 122 through a driver that performs a reciprocating half-turn together.

The north axis 125 of the north mechanism 120 is arranged parallel to the Y axis direction, and is located on the Y-axis direction (rear) with respect to the medium drum 121, and at the same time, the reciprocating half-rotation driving force is applied from this direction. Grant. In addition, the drum shaft 125 is a configuration in which the driving force branched from the sewing machine motor 105 is converted into a reciprocating rotation and transmitted, and the up and down reciprocating operation of the sewing needle 104 and the reciprocating semi-rotation operation of the medium drum case 122. Synchronization is achieved with a predetermined phase difference.

The upper thread guide plate 124 is a plate-shaped member for preventing contact or winding of the race faces 127 and 128 of the medium bobbin 122 of the upper thread, and is viewed from above in FIG. 3 (arrow U direction). A guide hole 124a having a shape as shown in the drawing is formed, and the thread separation for widening the upper thread loop hooked by the knife tip 121 of the medium-sized bobbin 122 is formed at approximately the center of the right side of the guide hole 124a. The part 124b is provided. As shown in Fig. 3, the upper thread loop hooked by the knife tip 121 has a thread N _F on the sewing needle side bordering the knife tip 121 by the thread separating part 124b. It is largely separated back and forth by the thread N _B of the cloth side, and the contact and the winding of the both race surfaces 127 and 128 of the medium drum case 122 are prevented.

(Cloth holding mechanism)

The cloth holding mechanism 140 is a cloth which can be moved by positioning in the X-axis direction and the Y-axis direction arbitrarily on the upper surface of the sewing machine bed 101 by the X-axis motor 83 and the Y-axis motor 84, which are stepping motors. The first swinging motion of the feed table 141, the cloth holding member 142 equipped to be liftable at the front end of the cloth feed table 141, and the cam 143 provided on the operation motor 82, which is a stepping motor. Transmission arm 144 which moves back and forth in response to oscillation of swing arm 144, the first swing arm 144, and L-shaped second swing arm 146 which swings in response to forward and backward movement of transmission rod 145. And a lifting body 147 to which shank movement is given by the second swinging arm 146, and a swinging rod 148 whose both ends are swingably supported by the cloth feed table 141.

The cloth transfer table 141 is attached to the upper part of the sewing machine bed 101 by the well-known structure so that arbitrary movement is possible along the X-Y plane. In addition, the cloth transfer table 141 is to be transmitted by converting the rotational driving force of the X-axis motor 83 and the Y-axis motor 84 to a moving force in the X-axis direction and Y-axis direction by a known power transmission structure. have.

That is, the cloth holding mechanism 140, the X-axis motor 83, and the Y-axis motor 84 hold the cloth and the buttons, which are to be sewn, move them randomly with respect to the sewing needle, and position them. It functions as a moving mechanism for dropping the needle in position.

The cloth holding member 142 is disposed above the needle plate 108, and can hold the button on the cloth in a state of being folded, and becomes the holding state at the time of falling, and releases the holding state at the time of rising.

The cloth holding member 142 is supported by the cloth transfer table 141 to be elevated, and is connected to one end of the swinging rod 148, and one end of the swinging rod 148 moves up and down by swinging. The cloth holding member 142 is also raised and lowered.

The swinging rod 148 is tensioned upward by a tension spring (not shown) at its other end, and the cloth holding member 142 is always pressed downward by this tension. In the vicinity of the other end of the swinging rod 148, a contact portion 148a is applied to which the pressing force is applied downward by the lower end of the lifting body 147.

The lifting body 147 is arranged so that its longitudinal direction is along the up-down direction, and it raises and lowers along the said longitudinal direction. The upper end of the elevating body 147 is connected to the second swinging arm 146, and the lower end is connected to the operation regulation link body 149 which stabilizes the posture of the elevating body 147. Then, the connecting end of the second swinging arm 146 swings up and down to give the lifting body 147 a vertical movement.

As described above, the second swing arm 146 is substantially L-shaped and is rotatably supported by the sewing machine frame at its bent portion. Then, the lower end of the second swinging arm 146 is connected to the transfer rod 145 to give the swinging motion back and forth, and to give the lifting body 147 a vertical movement on the upper end side.

The rear end portion of the transfer rod 145 is connected to one end of the first swing arm 144, and the other end of the first swing arm 144 is engaged with the cam 143.

The cam 143 is an outer circumferential cam rotated by the operating motor 82, and the other end of the first swinging arm 144 abuts the outer circumference of the cam 143, and the first swing is performed along the outer circumferential shape. Arm 144 is configured to swing.

The cloth holding mechanism 140 is set so that the cloth holding member 142 ascends when the motor output shaft is at a predetermined angle by the rotational driving of the operating motor 82. That is, the cloth and the buttons are maintained and released by the rotation angle control of the operation motor 82.

In addition, in the button sealing, there are a plurality of types of sealing operations for performing a series of sealing operations depending on the number and arrangement of the thread through holes of the button B (Fig. 17), the spacing of the holes, the order in which the threads pass, the presence or absence of thread cutting in the middle. Sewing data is stored in the operation control means 80. Then, one of the sewing data is selected, and button sealing is performed. At that time, the cloth holding mechanism 140 causes each needle to drop the needle through the predetermined number of times in a predetermined order in each thread through hole of the button B. Each time, the X-axis motor 83 and the Y-axis motor 84 are driven at the drive amount determined in the sewing data, and the movement positioning of the cloth feed table 141 and the cloth holding member 142 is performed.

In addition, the thread removal mechanism (not shown) is provided with a thread removal member which performs reciprocation rotation by receiving power from the second swinging arm 146 through a plurality of link bodies. Such a thread removing member is provided on the sewing machine face side side such that its tip portion passes between the needle plate and the lower end portion of the sewing needle at the needle upper position. Then, after the upper thread passing between the needle holes 108a of the needle plate 108 and between the bobbin mechanism 120 is cut, the thread removing member is rotated, so that the end of the cut upper thread can be pulled out above the fabric.

(Thread cutter tool)

4 is a plan view showing the main part of the thread cutting mechanism 130, and FIG. 5 is a view for explaining the operation thereof. As shown in Figs. 1, 4 and 5, the thread cutting mechanism 130 is formed of the first swinging arm 132 and the first swinging arm 132 which are rocked by a cam 131 installed in the operating motor 82. The transmission rod 133 moving back and forth by oscillation, the second swing arm 134 oscillating according to the forward and backward movement of the transmission rod 133, and the fixed blade 135 fixed to the lower surface of the needle plate 108. And a movable blade 136 for performing reciprocating rotation while slidingly contacting the blade edge of the fixed blade 135, and a link member 137 for coupling the movable blade 136 and the second swing arm 134 to each other. .

The cam 131 is a groove cam which is rotationally driven by the operation motor 82, and the upper end of the first swing arm 132 moves through the circumferential groove of the cam 131 to the cam 131. ) Therefore, the first swing arm 132 swings in accordance with the groove shape of the cam 131.

The first swinging arm 132 is pivotally supported on the sewing machine frame at its intermediate portion so as to be rotatable, and is disposed to substantially follow the Z-axis direction. The upper end is connected to the cam 131 as described above, and the lower end is connected to the rear end of the delivery rod 133. Accordingly, when the upper end portion of the first swinging arm 132 is rocked by the cam 131, the reciprocating motion in the front-rear direction is given to the transfer rod 133.

The second swing arm 134 is pivotally supported on the lower surface of the needle plate 108 at its longitudinal middle part, and its one end is connected to the front end of the transfer rod 133. In addition, the other end of the second swinging arm 134 is connected to the movable scalpel 136 through a link body 137, and the operating motor 82 is the first swinging arm 132 and the transfer rod 133. The second swing arm 134 and the link body 137 are finally provided with a reciprocating rotation of the movable blade 136.

The movable knife 136 is axially supported on the lower surface of the needle plate 108 so as to be rotatable, and the reciprocating rotational operation is made while slidingly contacting the upper surface of the movable knife 136 with the lower surface of the fixed knife 135. Do this. The movable scalpel 136 is evacuated at the dashed-dotted line in FIG. 4 and in the standby position shown in FIG. 5A at the time of non-cutting, and is moved forward as shown in FIG. After advancing to the position, the reciprocating rotation to return to the standby position is performed.

However, as described above, the upper thread is captured by the knife tip 121 of the medium drum case 122 to form an upper thread loop, and the upper thread is cut by the thread separating portion 124b of the upper thread guide plate 124. It is divided into a thread (N _F ) on the sewing needle side and a thread (N _B ) on the cloth side at the boundary of 121. In this state, the movable scalpel 136 cuts the upper thread. At this time, if the both sides of the sewing needle thread N _F and the upper thread N _B of the upper thread are cut, the upper thread is cut into two parts. In order to avoid this, only the yarn N _{B on the} fabric side is sorted and cut. In order to perform this sorting, the movable scalpel 136 is provided with a separating protrusion 136a protruding sharply toward the forward edge side.

The separating projection 136a passes between the thread N _F on the sewing needle side of the upper thread divided by the thread separating part 124b and the thread N _B on the cloth side at the time of the forward rotation of the movable knife 136. When the position is set so that the movable blade 136 performs forward rotation, only the thread N _B on the cloth side, which is outside the rotation radius, flows outward in the rotation radius direction of the movable blade 136. It returns to the thread capture part 136b provided in the receding edge part side (refer FIG. 5 (b)).

In addition, the room of cheoncheuk of the movable scalpel 136, the upper surface yarn trapping part (136b) by the retracting rotation of the blade portion, and (136c) are formed, the movable scalpel 136, the step formed than the top surface of the (N _B) Is cut into the cutting edge 136c and the front end of the fixed blade 135 (see Fig. 5 (c)).

As described above, the operation motor 82 can perform the operation of lifting and lowering the thread of the cloth presser foot and the operation of the thread cutter tool 130 through the cam 143 and the cam 131. In addition, each cam shape and its attachment angle are adjusted so that each operation | movement may be performed in the non-overlapping angle range in 1 rotation (0-360 degree) of the operation motor 82, respectively. In addition, as the operating motor 82 rotates in a predetermined direction, the "cloth holding member lowers", "the first movable blade forward", "the first movable blade retracted", "the reciprocating rotation of the thread removing member", " The cam shapes of the cam 143 and the cam 131 are set so that the second movable blade advance, the "second movable blade retreat", and the "cloth holding member raise" are executed in this order, and the operating motor 82 Is attached to.

(Upper thread retainer)

The upper thread holding device 10 has a sewing start end of the upper thread inserted into the sewing needle 104 at the start of sewing in order to prevent the end (sewing starting end) of the upper thread from being sewn out of the fabric. The needle plate 108 is inserted vertically below the needle hole 108a, and the end portion of the upper thread inserted is moved to a position away from the shanghai route of the sewing needle 104 toward the rear.

The upper thread holding device 10 starts the sewing of the upper thread between the holding part 21 holding the sewing start end of the upper thread and the holding part 21 relatively moving in the folding direction relative to the holding part 21. The thread holder 20 having a fitting portion 31 for fitting or releasing the end portion, and the thread holder 20 are positioned on the shank east path N of the sewing needle 104 (see FIG. 8). The tip position of the sewing needle 104 at the bottom dead center from the tip position of the sewing needle 104 at the top dead center, parallel to the shank east path (N; Z-axis direction) of the sewing needle 104 The moving means 40 for moving between the rear end (the sewing machine standing body portion 102 side) to the stand-by position, and the thread holder 20 when the thread holder 20 is located at the lower end of the needle. The holding tool 20 is in the released state, and the thread holding tool 20 is released from the released state between the needle lower position and the standby position. Associated operating means 60 for switching to the fitted state is provided. Hereinafter, each part is explained in full detail.

(Thread holder of upper thread holder)

FIG. 6 is a perspective view showing a major overall configuration of the upper thread holding device 10, and FIG. 7 is an exploded perspective view thereof.

As shown in these, the seal holder 20 is provided with the holding member 22 provided with the holding part 21, and the fitting member 32 provided with the fitting part 31. As shown in FIG. Each of these members 22 and 32 has a long plate shape in its entirety, and these are overlapped with the fitting member 32 facing up, and both of them are in the Y-axis in a state in which their longitudinal direction is parallel to the Y-axis direction. Both sides are supported by the associated operating means 60 so as to be slidable along the direction (front and rear direction). Hereinafter, in the case where a language indicating a direction is used in the description of each part of the thread holder 20, unless otherwise specified, the direction in the state in which the thread holder 20 is supported by the associated operation means 60 will be described. Shall be.

The holding member 22 has rectangular through-holes 23 and 24 formed in the front-rear and rear-side end portions, respectively, along the front-rear direction, and on the inner surface of the through-hole 23 on the front side. The holding part 21 is the site | part which includes the surface located in the most front end and opposes a Y-axis + direction. The through hole 23 on the front side also functions as a guide hole for guiding the movement of the fitting portion 31 in the front and rear directions.

In the through hole 24 at the rear side of the holding member 22, a tension spring 62 of the associated operation means 60, which will be described later, is disposed, and forms an operation region for stretching. One end of the tension spring 62 is connected to the front end of the rear through-hole 24.

In addition, at a position slightly rearward from the middle portion of the Y-axis direction of the retaining member 22, a bracket portion 25 is provided which is installed in the X-axis direction, and the end portion thereof has a round rod-shaped engaging portion extending downward. The pin 26 is fixed. The holding member 22 is input to the moving force in the front and rear direction by the associated operation means 60 through the engaging pin 26.

The fitting member 32 is divided into two parts, the front part 33 and the rear part 34, and are connected by the connecting member 35 to form an integrally long plate shape. A fitting portion 31 is provided at the front end portion of the front side portion 33, and the fitting portion 31 is fitted with the flat portion 30 which can be folded and contacted with respect to the holding portion 21. It has the curved part 36 which protrudes forward rather than the front end surface of the holding member 22 when passing down below the holding part 21 when it contacts.

Accordingly, the upper thread inserted through the front through hole 23 of the holding member 22 from the upper side by the closest approach operation of the holding member 22 and the fitting member 32 is held by the holding portion 21 and the fitting portion ( 31 can be fitted by the flat portion (30). In addition, the upper thread fitted is bent toward the front by the bent portion 36 provided in a row from the lower end of the flat portion 30 toward the front, and the upper thread can be bent from the front downward. As a result, the upper thread end portion is stretched further in the state positioned by the bent portion 36, and thus, the upper thread end portion is moved forward than the medium-sized bobbin 122 of the drum collecting mechanism 120 located below, and the medium bobbin 122 It can prevent contact or winding up.

The rear side portion 34 has a through hole 37 formed along the front and rear direction, and is provided with a through hole when the fitting member 32 and the holding member 22 are supported by the associated operating means 60 in an overlapped state. 37 is polymerized with the rear through-hole 24 of the holding member 22 described above, and a tension spring 62 of the associated operation means 60 is disposed inside thereof, whereby an operation region for stretching and contracting is provided. Form. The other end of the tension spring 62 is connected to the rear end of the through hole 37. Therefore, the fitting member 32 is in a state of being connected through the retaining member 22 and the tension spring 62, the fitting portion 31 of the retaining portion 21 and the fitting member 32 of the retaining member 22 is The elastic force is imparted in the direction of contact with each other at all times.

In addition, a bracket portion 38 which is installed in the middle of the Y-axis direction of the fitting member 32 in the X-axis + direction is provided, and a round bar-shaped engaging pin 39 extending downward is provided at the distal end thereof. Fixed equipment The fitting member 32 receives the moving force in the front-rear direction by the associated operation means 60 through the engaging pin 39.

(Means of movement of upper thread holding device)

The moving means 40 will be described with reference to FIGS. 6 to 14.

The moving means 40 moves the thread holder 20 to the needle lower position, the thread bending position, the standby position, and the thread relaxation position (middle position) for positioning.

When the seal holder 20 is moved in the front-rear direction by the moving means 40 in accordance with the structure of the associated operation means 60 to be described later, the holding member 22 is moved in accordance with each position in this moving direction. The opening and closing state of the holding part 21 and the flat part 30 of the fitting member 32 is changed.

Here, with the needle lower teeth, the holding part 21 of the holding member 22 and the flat part 30 of the fitting member 32 are completely opened, and the tip of the thread holding tool 20 is the shanghai path of the sewing needle. We say position becoming downward of (N).

The thread bending position is rearward of the needle lower end, and means the position before the holding part 21 of the holding member 22 and the flat part 30 of the fitting member 32 are completely closed.

The standby position means a position in which the holding portion 21 of the holding member 22 and the flat portion 30 of the fitting member 32 are completely closed, and are the rearmost of the four positions.

The thread loosening position means a position in which the holding portion 21 of the holding member 22 and the flat portion 30 of the fitting member 32 remain completely closed, and are located between the thread bending position and the standby position.

The movement means 40 includes a Y-axis movement mechanism 41 for reciprocating the yarn holder 20 supported by the associated operation means 60 along the Y-axis direction, and the yarn holder 20 is a needle lower value. And the movement position detecting means 46 for detecting whether or not it is at each position such as the standby position, and by the operation control means 80, the Y axis moving mechanism based on the detection of the movement position detecting means 46. The operation of 41 is controlled.

As shown in Fig. 7, the Y-axis moving mechanism 41 has a main clamping link body whose own swing center position is connected to an output shaft of the seal clamping motor 42 and the seal clamping motor 42 that output rotational driving force. (43), the driven link member (44) for imparting the movement force in the Y-axis direction to the relative position adjusting link (63) of the associated operation means (60), and the driven link member (44) from the main link member (43). The transmission link body 45 which transmits a driving force is provided.

The seal clamping motor 42 is a stepping motor and is driven at an arbitrary rotational angle with respect to the + -direction by the operation control of the operation control means 80.

One end of the main link member 43 is fixedly connected to the output shaft of the seal clamping motor 42, and the other end thereof is rotatably connected to one end of the transmission link member 45.

One end of the driven link member 44 is axially supported by a guide plate 61 to be described later of the associated operation means 60, and the other end thereof is rotatably connected to the other end of the transmission link member 45. . In addition, the substantially U-shaped driven link member 44 is provided with a engaging projection 52 for imparting a moving force along the Y-axis direction to the relative position adjusting link 63 of the associated operation means 60.

The transmission link member 45 is arranged to substantially follow the Y-axis direction, and swings the driven link member 44 along with the swing of the main link member 43 by the drive of the seal clamping motor 42.

With these configurations, when the seal clamping motor 42 is driven, the driven link member 44 swings together with the swinging of the main link member 43, and the associated operating means 60 is connected through the engaging projection 52. The relative position adjustment link 63 moves along the Y axis direction.

The moving position detecting means 46 will be described with reference to FIGS. 8 to 14. 6 and 7, the moving position detecting means 46 is not shown.

The moving position detecting means 46 includes first and second state sensors 47 and 48 having a light emitting element and a light receiving element and detecting the presence or absence of a shield therebetween, and the aforementioned Y axis moving mechanism 41. The shielding plate 51 is provided in the transmission link member 45 and has the 1st-3rd shielding area | regions 51a, 51b, 51c. These first to third shielding regions 51a, 51b, 51c are formed in order from the front end of the shielding plate 51 toward the rear.

The first and second state sensors 47 and 48 are arranged side by side along the moving line of the shielding plate 51 and the first state sensor 47 is disposed at the rear side. As a result, each of the state sensors 47 and 48 is almost in a state arranged side by side along the Y-axis direction. The light receiving elements of the respective state sensors 47 and 48 turn the state with the shield ON and the state without the shield with the OFF state, and output a signal for identifying each state to the operation control means 80. do.

On the other hand, the shielding plate 51 is fixed to the transmission link member 45 so as to pass between the light emitting element and the light receiving element with respect to both of the first and second state sensors 47 and 48. 3 shielding areas 51a, 51b, 51c are formed.

As shown in Fig. 8, when the thread holder 20 is at the lower end of the needle, the first to third shielding areas 51a, 51b, and 51c do not shield any of the sensors 47 and 48. It is. In other words, when the transmission link member 45 and the engaging projection 52 are advanced, the needle when the first state sensor 47 is in the OFF state (unshielded state) and the second state sensor 48 is also in the OFF state. Can be detected as a lower value.

As shown in Fig. 10, when the seal holder 20 is in the thread bending position, the first shielding area 51a does not shield any sensors 47 and 48, and the second shielding area 51b. The first state sensor 48 is shielded, and the third shielding area 51c shields the first sensor 47. That is, when the transmission link member 45 and the engaging projection 52 are retracted from the needle lower value, the first state sensor 47 is in an ON state (shielded state), and the second state sensor 48 is also in an ON state. Can be detected as the actual bending position.

As shown in Fig. 12, when the seal holder 20 is in the standby position, the first shielding area 51a shields the second sensor 48, and the second shielding area 51b is a certain sensor. The shields 47 and 48 are not shielded, and the third shielding area 51c and the sensors 47 and 48 are not shielded. That is, the standby position when the first state sensor 47 is in the OFF state and the second state sensor 48 is in the ON state when the transmission link member 45 and the engaging projection 52 are retracted from the actual bend position. Can be detected.

As shown in Fig. 14, when the seal holder 20 is in the thread relaxation position, the first shielding area 51a does not shield any of the sensors 47 and 48, and the second shielding area 51b. Do not shield any of the sensors 47 and 48, and the third shielding area 51c is arranged to shield the first sensor 47. That is, the thread relaxation position when the first state sensor 47 is in the ON state and the second state sensor 48 is in the OFF state when the transmission link member 45 and the engaging projection 52 are advanced from the standby position. Can be detected.

Here, the control performed on the Y-axis moving mechanism 41 by the operation control means 80 will be described. The operation control means 80 rotates in advance the amount of rotation of the thread clamping motor 42 for moving the thread holder 20 between the needle lower position and the standby position from the standby position to the thread relaxed position. The angle amount is also stored, and when the thread holder 20 is positioned at each position, the operation of the seal clamping motor 42 is also controlled with reference to the storage angle position.

In addition, with respect to the needle lower value, the operation control means 80 performs control as the initial position control part by using the movement position detecting means 46 when the main power is supplied to the sewing machine 100, and the thread clamping motor 42 Drive it to retrieve the needle sub-values and wait at that position.

In addition, the encoder 109 of the sewing machine motor 105 recognizes that the sewing needle 104 has been pulled upward from the cloth in the first needle stitch after sewing start, and then positions the thread holder 20 at the thread bending position. Control as the upper thread holding control unit is performed. In this thread bending position, a slight gap is formed between the holding portion 21 of the holding member 22 and the flat portion 30 of the fitting member 32, so that the upper thread is pulled by the pulling force of the take-up thread. The sewing start end of the upper portion of the upper thread is slidably moved to the sewing needle 14 while causing a sliding movement resistance between the holding portion 21 of the holding member 22 and the flat portion 30 of the fitting member 32. The holding length of the sewing start end can be reduced.

Then, when the second needle detects that the sewing needle 104 is pulled upward from the cloth by the encoder 109 of the sewing machine motor 105, the control for positioning the thread holder 20 in the standby position is performed. do. Thereby, the holding part 21 of the holding member 22 and the flat part 30 of the fitting member 32 are in a closed state, and even after receiving the tension of the thread take-up 107, the sewing start end of the upper thread is slidably moved. Is maintained.

Then, after the last needle drop, the upper thread and the lower thread passing from the needle hole 108a to the medium drum 122 are cut, and when the thread is removed, control is performed to position the thread holder 20 at the thread relaxation position. . Since the thread relaxation position is close to the needle hole 108a with respect to the standby position, the sewing start end of the upper thread is relaxed between the thread holder 20 and the needle hole 108a by this movement. The sewing start end can be infiltrated within the rotation range of the movable knife 136 of the thread cutting tool 130, so that the sewing start end of the upper thread can be cut in accordance with the rotation of the movable knife 136. FIG. In addition, the detailed description regarding the arrangement of the sewing start end of the upper thread and the movable knife 136 in the thread relaxation position will be described later.

(Related operating means of upper thread holding device)

The associated operation means 60 will be described with reference to FIGS. 6 to 16.

The associated operation means 60 includes a guide plate 61 as a guide means for supporting the fitting member 32 and the holding member 22 in a reciprocating manner along the Y-axis direction, and the fitting portion 31 and the holding portion ( 21 is a tension spring 62 serving as a tension pressing means for imparting a constant tension between the fitting member 32 and the retaining member 22 in a direction approaching each other, and the fitting portion according to a change in posture due to its own swing ( 31 and the holding portion 21 to be folded to be engaged with each of the fitting member 32 and the holding member 22, at the same time, each movement position of the seal holder 20 by the moving means 40 When the relative position adjustment link body 63 and the thread holder 20 are moved from the thread relaxation position to the needle lower position, the movement force with respect to the relative position adjustment link body 63 comes into contact with the fitting portion 31. ) And the first contact member 64 and the thread holder 20 for swinging in the direction of dropping the retaining portion 21 from the thread relaxed position. When moving to the stand-by position, the inclination of the relative position adjustment link body 63 is kept constant so as to slide in contact with the relative position adjustment link body 63 to keep the fitting portion 31 and the retaining portion 21 in close contact. It has a second contact member 65 to move rearward.

The guide plate 61 is fixed to the rear of the needle plate 108 above the sewing machine bed 103. Hereinafter, when a language indicating a direction is used in the description of each part of the associated operating means 60, unless there is a special reason, the guide plate 61 indicates the direction in the state in which the sewing machine bed 103 is fixedly equipped. do.

On the upper surface of the guide plate 61, the guide groove 66 along the Y-axis direction is formed in the intermediate position in the X-axis direction. In the guide groove 66, the holding member 22 and the fitting member 32 of the seal holder 20 are accommodated in a state overlapped in the longitudinal direction, and the pressing plate 67 is further provided therefrom. 22) and the fitting member 32 is covered so as not to fall off from the guide groove 66. Accordingly, the holding member 22 and the fitting member 32 are guided to the guide groove 66 so as to slide along the Y-axis direction, respectively. However, as described above, the holding member 22 and the fitting member 32 are connected through the tension spring 62, so that each member 22, 32 is the holding portion 21, unless an external force is applied. And the fitting portion 31 is maintained in contact with it. 9, 11, 13, and 15, the holding member 22 and the fitting member 32 are shown to have different widths in the X-axis direction, which clearly shows the relative positional relationship of the respective members 22, 32. FIG. For the sake of illustration, they are expressed to be different for convenience, and in reality, both the holding member 22 and the fitting member 32 are set to be substantially equal to the width of the X-axis direction of the guide groove 66 in the range in which the sliding movement is possible.

Furthermore, through holes 68 and 69 are formed on both sides with the guide groove 66 of the guide plate 61 interposed therebetween. The engaging pin 26 provided in the holding member 21 is inserted into the through hole 68 from one side, and the engaging pin 39 of the fitting member 32 is inserted into the other through hole 69. It is inserted. In addition, each of the through holes 68 and 69 has an angle in both the movement from the needle lower end of the thread holder 20 to the standby position and the relative movement of the holding member 22 and the fitting member 32 accompanying it. The length of the Y-axis direction is set so that both the front end part and the rear end part of each hole do not contact the engaging pins 26 and 39. In addition, the respective engaging pins 26 and 39 inserted through the through holes 68 and 69 are slightly protruded from the lower surface side of the guide plate 61, and the relative position adjusting link bodies 63 are individually provided. Is engaged in the

The relative position adjustment link member 63 is arranged side by side in the longitudinal direction and rotates between the rotation engaging portion 70 with the retaining member 22 and the fitting member 32 and between them. Rotating engagement portion 72 with the moving means 40 located in the is provided.

That is, the locking engagement portion 70 with the retaining member 22 is a long hole-shaped through hole in the longitudinal direction of the relative position control linkage 63, through which the locking pin 26 is inserted. The locking engagement portion 71 with the fitting member 32 is a circular through hole, through which the engagement pin 39 is inserted. The locking engagement portion 72 with the moving means 40 is a long hole-shaped through hole in the longitudinal direction of the relative position adjustment link member 63, and the locking engagement protrusion 52 is inserted therethrough.

FIG. 16 is an explanatory view as seen from below showing the relationship between the swinging motion of the relative position adjustment link member 63 and the change in the position of engagement of the retaining member 22 and the fitting member 32.

Referring to FIG. 16, the holding member 22 and the fitting member 32 are in contact with the holding portion 21 and the fitting portion 31 by the tension spring 62 unless the external force is applied as described above. maintain. This state becomes the holding state of the upper thread. The engagement pins 26 and 39 are arranged so that they are arranged side by side at substantially the same position with respect to the Y-axis direction when the retaining portion 21 and the fitting portion 31 are in contact with each other. Therefore, the relative position adjusting link member 63 connected through each of the engaging pins 26 and 39 and each of the pivot engaging portions 70 and 71 is also almost in a normal state by the tension of the tension spring 62. The state along the X-axis direction is maintained (state shown by the solid line of FIG. 16).

In this state, when a counterclockwise rotational force is applied to the relative position adjusting link body 63 around the engagement projection 52, the relative position adjusting link body 63 oscillates to change the posture. Cause At this time, by causing displacement in the Y-axis direction to each rotation engaging portion (70, 71), the holding portion 21 and the fitting portion 31 is separated from each other between the holding member 22 and the fitting member (32) External force in the direction is given. Therefore, the holding portion 21 and the fitting portion 31 fall against the tension of the tension spring 62, and the upper thread is switched from the holding state to the released state.

The first contact member 64 will be described with reference to FIGS. 9, 11 and 16. The first contact member 64 keeps the holding portion 21 and the fitting portion 31 apart from each other when the thread holder 20 is at the needle lower portion, and retains the portion when moving from the needle lower position to the standby position. (21) and the fitting part 31 are moved in the direction approaching each other, and the rocking | movement of the relative position adjustment link body 63 is operated so that it may contact at least at the position near a needle lower value rather than a thread relaxation position.

In order to realize the above operation, the first contact member 64 is pivotally engaged with the rotation member 72 and the fitting member 32 of the moving means 40 with respect to the relative position adjusting link member 63 positioned at the lower end of the needle. It is arrange | positioned so that abutting from the front between with the rotation engaging part 71 of (). With this arrangement, when the moving force to the front is applied to the relative position adjusting link member 63 by the moving means 40 to position the thread holder 20 at the needle lower value, the relative position The adjustment link member 63 swings against the tension of the tension spring 62 with the contact point with the first contact member 64 as a supporting point. At that time, the rotation engaging portion 71 of the fitting member 32 moves backward, and the rotating engaging portion 70 of the retaining member 22 moves forward. Therefore, since the holding portion 21 moves forward through the holding member 22 and the fitting portion 31 moves backward through the fitting member 32, they are separated from each other (see the dashed-dotted line in FIG. 16). ). In this state, the upper thread end is inserted between the holding part 21 and the fitting part 31.

Then, when the thread holder 20 moves backward from the needle lower end, the state of contact with the relative position adjusting link member 63 by the first contact member 64 is gradually released, so that the relative position adjusting link The sieve 63 is rotated clockwise by the tension of the tension spring 62. Therefore, the relative position adjustment link member 63 rotates clockwise until the state between the holding portion 21 and the fitting portion 31 is closed and the contact with the first contact member 64 is completely released. The part 31 moves forward through the fitting member 32, while the holding part 21 moves backward through the holding member 22.

In addition, in this embodiment, when the engaging projection 52 is moved to the rear side, the holding | maintenance part 21 and the fitting part 31 will be closed at some point, and if it moves back, the holding part 21 and The fitting part 31 is kept closed. In the sewing machine 100, in the rearward movement of the engaging projection 52, the position at which the gap between the holding portion 21 and the fitting portion 31 is initially closed is set at the thread relaxation position. Furthermore, since the thread bending position needs to be a position before the holding portion 21 and the fitting portion 31 are closed, the thread bending position is set slightly ahead of the thread relaxation position.

The second contact member 65 will be described with reference to FIGS. 11, 13, and 15. The second contact member 65 restricts the swing of the relative position adjusting link member 63 so as to maintain the fitted state when the thread holder 20 moves from the thread relaxed position to the standby position.

In order to realize the above operation, the second contact member 65 has an X-axis direction -side with respect to an area where the relative position adjusting link member 63 passes when the seal holder 20 moves from the thread relaxation position to the standby position. It is arranged to slide in contact with the relative position control linkage (63) from.

The sliding contact surface of the 2nd contact member 65 is formed smoothly along the Y-axis direction. And the sliding contact part 63a provided in the X-axis direction-side edge part of the relative position adjustment link body 63 is also smooth, and parallel to the Y-axis direction when the holding part 21 and the fitting part 31 contact | abut. It is formed so that it may become.

Accordingly, when the relative position adjusting link member 63 reaches the thread loosening position from the needle lower end in the state in which the relative position adjusting link member 63 is almost in the X-axis direction, the second contact member 65 makes sliding contact with the sliding contact portion 63a, In the stroke (stroke) from the thread relaxation position to the standby position, the state in which the sliding contact portion 63a is parallel to the Y-axis direction is maintained, and the contact state between the holding portion 21 and the fitting portion 31 is maintained.

Further, in the section from the thread relaxation position to the standby position, although the holding portion 21 and the fitting portion 31 can be kept closed even without the second contact member 65 by the tension of the tension spring 62. By the steep movement of the engaging projection 52, the holding portion 21 and the fitting portion 31 can be prevented from being opened due to the influence of inertia force or the like.

(Positioning of holding part and fitting part at each moving position)

When the thread holder 20 is positioned at the lower end of the needle, it is as described above that the holder 21 and the fitting portion 31 move in the direction away from each other. Then, when the needle lower reaches, as shown in Fig. 8, the holding portion 21 is located in front of the shank east path (N) of the sewing needle.

The tip portion of the fitting portion 31 is located at least behind the straight line M. The straight line M is a position at which the rear edge at the lower end of the needle hole 108a (the end of the Y-axis direction-side of the diameter along the Y axis direction of the circular needle hole 108a when viewed from below) ) And a straight line determined by connecting the upper end portion of one race surface 128 to be the rear of the medium drum case 122 disposed close to the rear side of the shanghai east path N of the sewing needle. By setting the distal end portion of the fitting portion 31 in this manner, the upper thread loop due to the first needle stitch in sewing is captured by the knife tip 121 of the medium bobbin 122, and the thread separating portion of the upper thread guide plate 124 ( In the case of being widened (expanded) by 124b, the tip of the fitting portion 31 is in contact with the upper thread so that the thread separating part 124b is not prevented from widening the loop, so that the upper thread is in contact with the race face 128. It can be effectively suppressed.

In addition, the position of the holding portion 21 or the line unit value of the fitting portion 31 is the first relative to the Y-axis length or the relative position adjusting link body 63 of the holding member 21 and the fitting member 32. It is determined by the position where the contact member 64 abuts. For example, if the contact position of the first contact member 64 is near the rotation engaging portion 72 of the moving means 40, the position of the retaining member 21 is further forward, and the line unit value of the fitting portion 31 is It is further rearward. In addition, if the abutting position is near the rotation engaging portion 71 of the fitting member 32, the position of the holding portion 21 is further rearward, and the line unit value of the fitting portion 31 is further forward.

When the thread holder 20 reaches the thread-relaxed position from the needle lower position, the holder 21 and the flat portion 30 of the fitting portion 31 abut, and the state of fitting to the rear standby position is maintained. do.

10 and 11 show the yarn bent position, FIGS. 12 and 13 are the standby position, and FIGS. 14 and 15 show the state in which the yarn holder 20 is located in the thread relaxed position.

Here, the relationship between the state of the upper thread in the standby position and the thread relaxation position, and the thread cutting mechanism 130 is demonstrated based on FIG. B is a button having at least two holes, and W is a cloth (sewn material) such as a garment which seals the button.

Fig. 17A shows the arrangement at the moment when the thread holder 20 is in the standby position and the movable blade 136 of the thread cutter tool 130 is switched from the forward rotation to the backward rotation. At this time, the sewing start end of the upper thread extends straight from the needle hole 108a to the tip of the thread holder 20, and the thread holder 20 is located far behind the movable knife 136. That is, the standby position of the thread holder 20 is a position away from the movable knife 136 such that the sewing start end of the upper thread is not captured by the movable knife 136 even if the movable knife 136 performs the retraction rotation. Is set to.

FIG. 17B shows the arrangement at the moment when the thread holder 20 moves from the standby position to the thread relaxation position, and the movable knife 136 of the thread cutter tool 130 is switched from the forward rotation to the retraction rotation. will be. At this time, the sewing start end of the upper thread is relaxed between the needle hole 108a and the thread holder 20 to a position lower than the movable scalpel 136, and the upper thread of the upper thread in the flat fan-shaped region indicating the rotation range of the movable scalpel. The sewing start end has entered. Therefore, when the movable knife 136 performs the retraction rotation, the sewing start end of the upper thread is captured by the movable knife 136 (FIG. 17C), and is conveyed to the fixed knife 135 to start the sewing start end of the upper thread. Is cut.

That is, the thread relaxation position is a position where the upper thread end that has been held can be cut, specifically, the movement trajectory of the movable blade 136 by the sewing start end of the upper thread by loosening the upper thread by movement from the standby position. It is required to set it as the position which can penetrate into the area | region on the plane which shows.

In addition, if only the cutting start end of the upper thread is cut, it is sufficient to set the thread relaxation position to some extent ahead of the standby position in order to satisfy the above condition. However, it is preferable to realize the separation from the thread holder 20 as shown in Fig. 17C together with the cutting of the sewing start end of the upper thread. Therefore, in order to achieve such separation, it is required to make the relaxation length which occurs at the sewing start end of the upper thread shorter than the length consumed by the movable blade 136 to reach the fixed blade.

In addition, in order to satisfy these conditions, (1) the movable knife 136 carries the sewing start end of the upper thread toward the fixed knife 135 and from the needle lower end of the thread holder 20 to the standby position. Comprising moving direction components in which the moving directions are opposite to each other (more preferably in opposite directions), (2) the frictional force at the time of pulling out the sewing start end of the upper thread by the insertion of the thread holder is at least the upper thread It is also required to be below the endurance tension of.

(Operation control means)

The operation control means 80 will be described with reference to FIG. 18 is a block diagram showing a control system of the sewing machine 100. Although not shown in detail, these control means 80 are used as CPUs for performing various arithmetic operations, various programs for various processes such as control and judgment, stored and stored, and a work memory in various processes. It is roughly comprised by RAM and the EEPROM which stored various sewing data. The control means 80 includes a first state sensor 47 of the sewing machine motor 105, its encoder 109, the thread clamping motor 42, and the movement position detecting means 46 via a system bus and a driving circuit. ), The second state sensor 48, the S / S (start stop) switch 81 of the sewing machine 100, the operation panel 85 for inputting sewing setting conditions or selecting sewing data, driving causes such as thread cutting, etc. The operation motor 82, the X-axis motor 83, the Y-axis motor 84, etc. for moving the to-be-sealed object are connected.

The control means 80 can recognize the rotation angle of the sewing machine motor 105 based on the pulse signal input from the encoder 109 provided on the output shaft of the sewing machine motor 105.

In addition, the control means 80 is based on the detection signal input from the first state sensor 47 and the second state sensor 48 of the movement position detecting means 46, each movement position of the seal holder 20 You can check.

In addition, when the sewing start signal is input from the start switch 81, the control means 80 moves according to the rotation angle of the sewing machine motor 105 and the operation position detection of the movement position detection means 46, which are checked and recognized. The drive of the seal clamping motor 42 of the means 40 is controlled.

(Operation explanation of the sewing machine)

An operation of the sewing machine 100 having the above configuration will be described with reference to FIGS. 8 to 19. 19 is a flowchart showing the operation control of the sewing machine 100. In addition, it will be explained on the premise that sewing data and various necessary parameters for setting the needle drop position of each needle in order to perform button sealing are set in advance.

The following processing is realized by the CPU executing the control program stored in the ROM of the control means 80.

First, when the control means 80 receives the input in the input standby state of the S / S switch 81 (step S1), the control means 80 rotates the operating motor 82 at an angle to execute "lower cloth holding member". The cloth holding member 142 is lowered to hold the cloth and the button (step S2).

Then, the needle position value detection (initial position detection) is performed by the movement position detecting means 46 (step S3). When the lower end of the needle drives the thread clamping motor 42 in the direction in which the transmission link member 45 and the engaging projection 52 move forward, the first state sensor 47 is turned off, and the second state sensor ( 48) is also judged by the OFF state. Thereby, the thread holding tool 20 can be arrange | positioned on the shanghai east route N of a sewing needle (state of FIG. 8, 9).

Next, the drive of the sewing machine motor 105 is started (step S4). Further, after that, the driving of the X-axis motor 83 and the Y-axis motor 84 is controlled so that the needle falls to the needle drop position indicated by the sewing data for each needle.

By the operation of the sewing machine motor 105, the needle drop of the initial needle stitch is made, the sewing needle 104 is inserted into the needle hole 108a of the needle plate 108, the holding portion 21 and the fitting portion 31 The upper thread passes between and. In addition, the upper thread loop of the flank of the sewing needle 104 is captured at the knife end of the bobbin mechanism 120 from below. The upper thread loop is widened by the rotation of the middle drum 122 and the upper thread guide plate 124. At this time, the upper thread of the fitting portion 31 is located sufficiently backwards, so that the upper thread by the upper thread guide plate 124 It does not prevent the loop from expanding. Thus, contact of the upper thread to the rear race face 128 is prevented.

Furthermore, if it appears from the encoder 109 of the sewing machine motor 105 that the sewing needle 104 of the first stitches has come out of the cloth, the operation control means 80 is the thread clamping motor 42 of the moving means 40. Operation control is started to start the drive so as to move the yarn holder 20 to the yarn bent position (step S5).

The thread bending position is that when the thread clamping motor 42 is driven in a direction in which the transmission link member 45 and the engaging projection 52 retreat from the needle lower value, the first state sensor 47 is in an ON state, It is determined by whether the second state sensor 48 is also in the ON state. Thereby, the thread holding tool 20 can be arrange | positioned in a thread bending position (state of FIG. 10, 11).

In the process of moving the thread holder 20 from the needle lower end to the thread bending position, the sewing start end of the upper thread is held in the thread holding part. After the movement to the thread bend position, the upper thread is pulled up by the thread take-up 107 (step S6). In the thread bending position, since a small gap is formed between the holding portion 21 and the fitting portion 31, the upper thread slides with a predetermined frictional resistance therebetween, and the upper thread moves from the fitted portion to the end portion. The length of the upper thread can be shortest.

Subsequently, if it appears from the encoder 109 of the sewing machine motor 105 that the sewing needle 104 of the second needle comes out of the cloth, the operation control means 80 is the thread clamping motor 42 of the moving means 40. Is started to drive to move the seal holder 20 to the standby position (step S7).

In the standby position, when the thread clamping motor 42 is driven in the direction in which the transmission link member 45 and the engaging projection 52 retreat from the thread bending position, the first state sensor 47 is turned off. It is determined by whether the state sensor 48 is in the ON state. Thereby, the seal holder 20 can be arrange | positioned in a standby position (state of FIG. 12, 13).

Further, only while the thread holder 20 moves to the standby position, the thread tension solenoid 86 is controlled to reduce the thread tension of the thread tension adjusting device 106 to the normal sewing tension (step S8).

By the movement of the thread holder 20 to the standby position, the sewing start end of the upper thread is pulled vertically backward from the needle hole 108a.

After the movement to the standby position, the upper thread is pulled up by the thread take-up 107 (step S9). In the stand-by position, the gap between the holding portion 21 and the fitting portion 31 is close, so that nodules between the upper thread and the lower thread are tightly tightened, and needle stitches are prevented from being released.

Subsequently, a determination is made as to whether the next needle drop is final from the sewing data (step S10). And if it is not final, sewing is continued according to sewing data.

In the final case, it is determined from the output of the encoder 109 whether the upper shaft rotated by the sewing machine motor 105 is a predetermined thread cutting angle (step S11). The thread cutting angle is an angle at which a loop of the upper thread is picked up from the lowered sewing needle 104, and is sufficiently separated into the thread N _F on the sewing needle side and the thread N _B on the cloth side by the thread separating part 124b. to be.

When the actual cutting angle is detected by the encoder 109, the operation control means 80 rotates the operating motor 82 at an angle for executing the "first moving blade advance", and moves the movable blade 136. It rotates in the direction away from the fixed blade 135, and performs real sorting (step S12).

Subsequently, after the sewing machine motor 105 is stopped (step S13), the operation control means 80 rotates the operation motor 82 at an angle for executing the "first movable blade retraction", and the movable blade ( 136) to rotate in the turning direction being toward the fixed scalpel 135, it is cut cheoncheuk chamber (N _B) and the lower thread of the needle thread (step S14). At this time, as shown in Fig. 17 (A), since the sewing start end of the upper thread is pulled vertically back from the needle hole (108a), it is captured or cut by the movable scalpel 136 performing forward and backward There is no case.

Furthermore, after cutting the thread, the operation control means 80 rotates the operating motor 82 at an angle for performing "reciprocating rotation of the thread removing member", and reciprocates the thread removing member below the sewing needle 104. By rotating, the thread N _F on the sewing needle side of the upper thread is removed from the cloth and removed (step S15).

Subsequently, the operation control means 80 determines whether or not the needle drop position of the first needle stitch and the final needle drop position are the same position from the selected sewing data (step S16).

If the needle drop position of the first needle stitch and the final needle drop position are the same, the process proceeds to step S18, and if different, moves the fabric and the button to the position where the needle drop is made at the needle drop position of the first needle stitch. After drive control of the X-axis motor 83 and the Y-axis motor 84 is performed (step S17), the process proceeds to step S18.

In step S18, operation control is started to start driving the thread clamping motor 42 of the moving means 40 to move the thread holder 20 to the thread relaxed position.

The thread relaxation position is defined by the first state sensor 47 being turned ON when the thread clamping motor 42 is driven in the direction in which the transmission link member 45 and the engaging projection 52 move forward from the standby position. It is determined by whether the state sensor 48 is in the OFF state. Thereby, the thread holding tool 20 can be arrange | positioned in a thread relaxation position (state of FIG. 14, 15).

When the thread holder 20 moves from the standby position to the thread relaxed position, as shown in Fig. 17B, the sewing start end of the upper thread is threaded from the needle hole 108a of the needle plate 108. It is in a state of great relaxation between 20).

Then, the operation control means 80 rotates the operating motor 82 at an angle for executing the "second movable blade advance", and further executes the "second movable blade retraction" for the operating motor 82. The rotary blades are reciprocated by rotating at an angle to be adjusted. At this time, since the sewing start end of the upper thread is largely relaxed downward, it is captured by the movable scalpel 136 rotating back and pulled backward (FIG. 17C). For this reason, the sewing start end of the upper thread is pulled out from the thread holder 20.

Further, the sewing start end of the upper thread is cut by being fitted to the blade portion 136c of the movable blade 136 and the blade portion of the tip of the fixed blade 135 (Fig. 17 (D)). The sewing start end of the cut upper thread falls within the cover of the sewing machine and is recovered. Moreover, you may install the extractable exclusive support tray in the bottom part of a sewing machine.

Subsequently, after cutting the sewing start end of the upper thread, the operation control means 80 rotates the operation motor 82 at an angle for executing the " cloth holding member rise " to raise the cloth holding member 142. , The cloth and the button are released from the holding state (step S20).

(Effect of Embodiment)

As described above, in the sewing machine 100, since the sewing start end is held in the thread holder 20 until the end, the situation in which the thread knot state occurs due to the needle stitches of the lower thread like the case of being released in the middle can be effectively avoided. Will be.

Since the thread cutting tool 130 is operated after moving the thread holder 20 from the standby position to the thread relaxed position after the last needle drop, the needle holder 108a extends from the needle hole 108a toward the thread holder 20. Since the sewing start end of the upper thread in the present state is relaxed and becomes slightly sag under the needle hole 108a, the movable knife 136 of the thread cutting tool 130 can cut the sewing start end. In addition, at this time, the thread holder 20 does not release the sewing start end of the upper thread, unlike the case of cutting the stretched thread in a free state, the thread cutter tool 130 can perform a good cutting. .

Further, when the first needle drop position and the last needle drop position do not coincide with each other, the operation control means 80 sews the first needle drop position by driving the X and Y axis motors 83 and 84. Since the thread holder 20 is moved to the thread-relaxed position after the position is adjusted, the position at the base of the cloth side of the sewing start end of the upper thread can be made close to the needle hole of the needle plate. Accordingly, when the thread holder 20 is moved to the thread loosening position, the sewing starting end of the upper thread can be further relaxed, and the sewing cutting end of the upper thread can be more surely cut by the thread cutting tool 130. do.

In addition, it becomes possible to shorten the sewing start end of the upper thread left on the cloth side after cutting.

(Etc)

Further, the operation control means 80 of the sewing machine 100 cuts the upper thread and the lower thread passing from the needle hole 108a to the medium drum 122, and then cuts the sewing start end of the upper thread by a drive different from that. Although the upper thread, the lower thread and the sewing start end of the upper thread passing from the needle hole 108a to the medium drum 122 may be trimmed and cut in one by one reciprocating rotation of the movable knife 136. In that case, by the rotation of the operation motor 82 in the predetermined direction, "cloth holding member lower", "moving blade advance", "moving blade retraction", "reciprocating rotation of the thread removing member", "cloth holding member raising" The cam shapes of the cam 143 and the cam 131 need to be set so as to be executed in this order. In that case, of the above-described processing of steps S1 to S20, the processing of steps S16 and S17 is performed after step S11, and the processing of step S18 is performed after step S12 or S13, and the processing of step S20 The process can be realized after the step S15 and without the process of the step S19.

1 is an overall side view of a part of the sewing machine outlined.

FIG. 2 is a plan view of the upper thread guide plate viewed from the U direction in FIG. 8. FIG.

3 is a front view of the medium drum of the drum mechanism as seen from the X-axis direction.

4 is a plan view of a thread cutting tool.

5 is an explanatory view of the operation of the thread cutting tool, Figure 5 (a) is a movable blade waiting state, Figure 5 (b) is a movable blade forward rotation state, Figure 5 (c) is a movable blade retraction rotation state The figure shown.

6 is a perspective view showing a major overall configuration of the upper thread holding device.

7 is an exploded perspective view showing the main configuration of the upper thread holding device.

8 is an explanatory view of the operation of the upper thread holding device viewed from the right side when the thread holder is at the needle lower end;

Fig. 9 is an explanatory view of the operation of the upper thread retaining device viewed from below when the thread retaining tool is at the needle lower end;

10 is an explanatory view of the operation of the upper thread holding device viewed from the right side when the thread holder is in the thread bending position.

11 is an operation explanatory view of the upper thread holding device viewed from below when the thread holding tool is in the thread bending position.

12 is an explanatory view of the operation of the upper thread holding device viewed from the right side when the thread holder is in the standby position.

It is explanatory drawing of operation | movement which looked at the upper thread holding | maintenance apparatus from the downward direction when a thread holding | maintenance tool is in a standby position.

14 is an explanatory view of the operation of the upper thread holding device viewed from the right side when the thread holder is in the thread-releasing position.

It is explanatory drawing of the operation which looked at the upper thread holding | maintenance device from the case where a thread holding tool is in a thread relaxation position.

Fig. 16 is an explanatory view viewed from below showing the relationship between the rocking motion of the relative position adjustment link member and the relative position change of the retaining member and the fitting member.

Fig. 17 is an operation explanatory diagram showing the relationship between the state of the upper thread and the thread cutting tool in the standby position and the thread relaxation position, and Fig. 17A shows the movable knife cutting operation state in the thread holding tool standby position, (B) is the moving blade forward rotation state at the thread holder thread relaxation position, FIG. 17 (C) is the moving blade retraction rotation state at the thread holder thread relaxation position, and FIG. 17 (D) is the seal holder thread The figure which shows the cutting state of the sewing start end of the upper thread in the movable blade retraction rotation state in the relaxed position.

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

19 is a flowchart of operation of the sewing machine.

Explanation of symbols on the main parts of the drawings

10: upper thread holding device 20: thread holding device

40: moving means 60: related operation means

80: motion control means 83: X-axis motor

84: Y axis motor 100: sewing machine

104: sewing needle 108: needle plate

108a: needle hole 130: thread cutting tool

140: cloth organic mechanism (moving mechanism)

M: Straight line connecting the edge of the north axis of the needle hole to the upper edge of the race face of the north axis of the medium drum

N: Shanghai East Path of Sewing Needle

Claims (4)

Upper thread holding device which can switch the maintenance and release of the sewing start end of the upper thread from the lower side of the needle plate, A bobbin mechanism for trapping the upper thread under the needle hole of the needle plate to bind the lower thread; A thread cutter tool for cutting the upper thread and the lower thread passing between the needle hole of the needle plate and the bobbin mechanism; A sewing machine for sewing a button to a to-be-sealed object by alternately dropping a needle into at least two button holes, The upper thread retaining device may move along the needle plate between the needle lower value which is on the passage line of the sewing needle and the standby position away from the needle lower value, and the sewing start end of the upper thread at the needle lower value. And a thread holder which is in a released state to be released, and becomes a holding state for holding the sewing start end from a predetermined intermediate position to the standby position on the way from the needle lower position to the standby position, At the first needle drop of the start of sewing, the thread holder is the lower needle level. After that, the thread holder is held at the standby position at least after the last needle drop, and the thread holder is held after the last needle drop. And an operation control means for cutting the sewing start end of the upper thread by moving the thread cutting tool from the standby position to the intermediate position. The method of claim 1, The operation control means cuts the upper thread and the lower thread passing between the needle hole of the needle plate and the bobbin mechanism by operating the thread cutting tool while keeping the thread holder at the standby position after the final needle drop is completed. And then, the thread holder is moved to the intermediate position to cut the sewing start end of the upper thread. The method of claim 1, The operation control means cuts the sewing start end of the upper thread and the lower thread and the upper thread passing between the needle hole of the needle plate and the bobbin mechanism by one operation of the thread cutting tool after the final needle drop is completed. Sewing machine, characterized in that. The method according to any one of claims 1 to 3, It is provided with a moving mechanism of the to-be-sealed object which moves the to-be-sealed object which button sealing is made, and falls the said needle into a predetermined position, The operation control means, if the first needle drop position and the last needle drop position does not coincide, after the last needle drop, before moving the thread holder to the intermediate position, the sewing material with respect to the sewing needle Sewing machine characterized in that for controlling the movement mechanism to be positioned in the initial needle drop position.

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