JP2009118906A - Device for gripping needle thread for sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for gripping a needle thread for a sewing machine capable of easily removing a loop from a thread catching section even when the distal end side of the thread end portion of the needle thread is sewn into the sewing line in the cloth back to form the loop passing through the thread catching section. <P>SOLUTION: The device for holding the needle thread comprises a thread catching section 33 having an opening/closing body 35 arranged openably and closably a cutout 34 and the opening of the cutout 34, and the upper thread holding means 26 is formed between a first holding member 31 in which a first holding section 24 is formed by the site closing the opening of the cutout 34 of the opening/closing body 35 and a second holding member 32 arranged so as to be able to relatively contact with and be separated from the first holding section 24 and having a second holding section 25 holding the thread end portion TA of the needle thread T between the first holding section 24 and the same. The first holding section 24 is movably formed so as to bring the thread catching section 33 into an open condition by the needle thread T after holding the needle thread T. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an upper thread clamp device for a sewing machine such as an industrial sewing machine, and in particular, for holding a thread end portion of an upper thread inserted through a first stitching needle at the start of sewing under a needle plate. The present invention relates to an upper thread clamp device for a suitable sewing machine.

  Conventionally, the thread end of the upper thread (needle thread) inserted through the threading hole of the first stitching needle at the start of sewing is formed below the needle plate for the purpose of reliably forming the stitch at the beginning of sewing. Various types of upper thread gripping devices that can be held (hereinafter simply referred to as upper thread gripping devices) have been proposed (see, for example, Patent Document 1).

  In such an upper thread gripping device, a thread catching portion (through hole) formed in a frame shape is arranged on the vertical movement path of the sewing needle at the start of sewing, and the inside of the thread catching portion at the first stitch at the start of sewing is arranged. After the upper thread is captured, the thread catching portion is separated from the vertical movement path of the sewing needle, and then the first clamping portion constituting a part of the inner hole of the thread catching portion and the first clamping portion are opposed to each other. The upper end of the upper thread, specifically, the vicinity of the upper end of the upper thread (the end of the upper thread) is clamped between the second holding parts that are arranged so as to be able to come into contact with and away from each other. After two or three needles have been dropped, the end of the upper thread that has been clamped is released.

JP 2004-167007 A

  However, in the conventional upper thread clamp device, when the leading end side of the thread end portion of the clamped upper thread is sewn into the seam on the back of the fabric to form a loop passing through the thread capturing portion, the loop is removed from the thread capturing portion. There was a problem that it was not possible.

  In this way, if the loop cannot be released from the thread catcher, that is, if the upper thread end does not come off from the thread catcher, fabric misalignment (sewing shape misalignment), thread breakage, malfunction of the device, etc. Will occur and a stable seam cannot be obtained.

  Here, the back of the fabric refers to a surface on the throat plate side of the fabric as a sewing object placed on the throat plate at the time of sewing.

  The fact that the loop of the upper thread does not come off from the thread catching portion will be specifically described with reference to FIGS.

  In the conventional needle thread clamp device 101, when the first needle drop (first stitch) at the start of sewing is performed, the sewing needle N moves along the vertical movement path NL. At this time, the sewing needle N is a cloth placed on the needle plate P disposed in the bed portion MB in a state where the upper thread T is inserted into the threading hole Na provided near the tip. C is pierced and descends below the needle hole Pa of the needle plate P. The lowering of the sewing needle N is performed through a flat frame-shaped thread catching portion 103 provided on the first clamping member 102. When the sewing needle N is raised, an upper thread loop TL is formed. The upper thread loop TL is scooped with the sword tip Ka of the hook K, so that the tip Ta is in a suspended state, and the upper thread T is captured inside the thread capturing portion 103. The thread catching portion 103 is separated to the side of the vertical movement path NL of the sewing needle N after catching the upper thread T, and then the first clamping portion 104 constituting a part of the inner surface 103a of the thread catching portion 103. And an upper thread T between the second clamping part 106 (disposed so as to face the first clamping part 104) provided in the second clamping member 105 (see FIG. 32).

  In this state, when a predetermined number of stitches are dropped, for example, when the sewing needle N moves up and down by one stitch (second stitch) or two stitches (second and third stitches), the upper thread T A seam S is formed on the fabric C which is knotted and placed on the needle plate P. The upper thread that is clamped between the first clamping part 104 and the second clamping part 106 before the needle drop (third or fourth stitch) after the upper thread T and the lower thread are knotted. T is released, and the stitches S are sequentially formed in this state. Further, the tip Ta of the upper thread T comes out of the thread catcher 103 by feeding the fabric C as the sewing progresses.

  Here, the thread end TA, which is the part of the upper thread T that has been clamped between the first clamping part 104 and the second clamping part 106 at the first stitch and has passed through the thread catching part 103, is the upper thread loop of the second stitch and thereafter. When it is positioned on the TL pulling path, for example, on the passing path of the sword tip Ka of the hook K, the thread end TA enters the inside of the second thread upper thread loop TL (FIG. 33).

  At this time, the length of the yarn end TA of the upper thread T clamped between the first clamping unit 104 and the second clamping unit 106, more specifically, the length from the clamping part of the upper thread T to the tip Ta (hereinafter referred to as the following) , “Thread end length”) is longer than the distance from the pinching point of the upper thread T to the needle drop point DP of the fabric C, the thread end TA of the upper thread T is the upper thread loop TL. When the upper thread T is pulled up by a balance (not shown), the thread end TA of the upper thread T is pulled up together with the upper thread loop TL (FIG. 34).

  Therefore, when the lifting of the upper thread T is completed, the tip Ta side of the thread end TA of the upper thread T that has passed through the thread catching portion 103 is sewn into the seam S on the back of the fabric, and the loop W passing through the thread catching portion 103 is reached. (Different from the upper thread loop TL used for forming the seam S) is formed (FIG. 35).

  The loop W separates the first clamping unit 104 and the second clamping unit 106 from each other, so that even when the clamped upper thread T is released, the loop catching unit 103 does not come off from the yarn capturing unit 103. Therefore, the fabric C is pulled or pulled by the increase in the number of stitches, that is, the feeding of the fabric C as the sewing proceeds, so that the fabric shift (sewing shape shift), Thread breakage, device malfunction, etc. occur.

The “thread end length” of the upper thread T when being held by the upper thread clamp device 101 is mainly:
1: Length from the threading hole Na to the tip Ta of the upper thread T at the start of sewing (hereinafter referred to as “insertion length”)
1-1. “Insertion length” of the upper thread T after thread trimming in the previous sewing cycle
⇒Tension (adjustment value) of upper thread T during thread trimming / resistance of fabric C and upper thread T 1-2. If the upper thread T has been changed, the “insertion length” of the upper thread T (by the operator)
2.1 Resistance of upper thread T and fabric C at the needle stitch 3. Resistance of upper thread T and sewing thread path parts (needle bar guide, needle hole guide, arm thread guide, etc.) at the first stitch
4. Additional tension to upper thread T at the 1st stitch (tension by normal thread tension: adjustment value)
5). Thread take-up spring tension, stroke (adjustment value)
6. It is determined by the six elements of the length of the first stitch seam S and the thickness of the fabric C.

  Here, regarding the elements 2 and 5, when the resistance of the upper thread T and the fabric C is large, when the upper thread T is pulled up by the balance, the resistance of the upper thread T and the fabric C is lost and the amount of movement of the thread take-up spring operates. As a result, the amount of the upper thread pulled up decreases, and the length of the upper thread T remaining on the back of the fabric increases. As a result, the “thread end length” of the upper thread T becomes longer.

  For the element 3, as long as the gauge is not exchanged, the “thread end length” of the upper thread T is constant and no variation occurs. The gauge can include thread path parts such as a needle bar guide, a needle hole guide, and an arm thread guide. Further, the gauge exchange refers to each thread path gauge exchange by sewing thick materials or the like.

  Regarding the element 4, the variation in the “thread end length” of the upper thread T can be suppressed by controlling the thread tension when the upper thread T is clamped higher than the sewing tension value. The thread tension when the upper thread T is pinched is the thread tension at the time of capturing the upper thread T of the first stitch, and is, for example, temporarily increased to the maximum tension and stabilized. The sewing tension value refers to the tension during normal sewing after the second stitch.

  For the element 6, the first clamping member 102 captures the upper thread T by the thread catching portion 103 at the first stitch and then clamps the upper thread T by cooperation with the second clamping member 105 at the second stitch. If the length of the seam S is long and the thickness of the fabric C is thick, the upper thread T is consumed, and the “thread end length” of the upper thread T when the upper thread T is clamped is shortened. In many cases, the “insertion length” is adjusted to a long length. When a small pitch is set at the start of sewing or when the thickness of the fabric C is reduced, the “thread end length” of the upper thread T becomes longer. .

  Note that the resistance of the upper thread T and the fabric C, the length of the seam S (sewing pitch), the thickness of the fabric C, and the like change when the sewing object changes, depending on the quality and characteristics of the upper thread T and the fabric C. In some cases, the resistance changes with each sewing. For this reason, the “insertion length” of the upper thread T at the start of sewing changes depending on the sewing conditions and the condition change, and the “thread end length” of the upper thread T changes accordingly. In many cases, the “insertion length” set by the operator at the time of thread change is made longer in consideration of safety.

  If the “insertion length” at the start of sewing is short, the thread end TA is detached from the thread catching portion 103 of the first clamping member 102 before the upper thread T is clamped, and the upper thread T cannot be clamped. Therefore, the thread catching portion 103 of the first clamping member 102 is brought close to the vertical movement path NL of the sewing needle N so that the upper thread T can be captured and clamped even when the “insertion length” is short.

  However, in such a configuration, when the thread catching portion 103 is in the vicinity of the vertical movement path NL of the sewing needle N and the “insertion length” is long intentionally (adjusted) or due to variations, the second stitch Thereafter, the back of the fabric is sewn and a loop W is generated.

  Further, in the conventional thread clamp device 101, when the “thread end length” of the upper thread T is longer than the distance from the position where the upper thread T is clamped to the needle drop point DP of the fabric C, the clamping time is long. As the (number of stitches) increases, the upper thread loop TL passes repeatedly, so that the thread end TA is pulled up and the frequency of sewing is increased.

  After the upper thread T is pinched by the second stitch, the thread catching portion 103 is moved to a position away from the vertical movement path NL of the sewing needle N while keeping the pinched state, and the pulling path of the upper thread loop TL after the second stitch For example, the thread end TA of the upper thread T clamped from the hook K can be separated, but in this case, the clamped upper thread T is also moved. As a factor, if the clamping force is weak, if the yarn end TA of the upper thread T that is clamped is short, it will come off from the clamping part.

  Therefore, even when the tip of the thread end of the upper thread that is clamped is sewn into the seam on the back of the fabric to form a loop that passes through the thread catcher, the top of the sewing machine that can remove the loop from the thread catcher There is a need for a thread clamp device.

  The present invention has been made in view of this point, and even when the tip end side of the thread end portion of the upper thread being held is sewn into the seam on the back of the fabric and a loop passing through the thread catching portion is formed, An object of the present invention is to provide an upper thread clamp device for a sewing machine that can easily and reliably remove a loop from a catching section.

  In order to achieve the above-mentioned object, the upper thread gripping device of the sewing machine according to claim 1 of the present invention is characterized by the upper thread clamping means for capturing and clamping the thread end of the upper thread, Driving means for driving the upper thread clamping means, and at the beginning of sewing, the thread end of the upper thread inserted through the threading hole of the sewing needle is positioned below the needle plate of the bed section and The sewing machine is formed so that it is captured and clamped at a position separated from the vertical movement path of the sewing needle, and then the needle end of the upper thread that has been clamped is released after the preset number of stitches has been dropped. In the upper thread gripping device, the upper thread clamping means includes a thread catching portion including a notch and an opening / closing body arranged to be able to open and close the opening of the notch, and 1st clamping member in which the 1st clamping part was formed by the site | part which obstruct | occludes opening A second clamping member provided with a second clamping part that is disposed so as to be able to contact and separate relative to the first clamping part and clamps the yarn end part between the first clamping part and the first clamping part. The thread catching portion forms a frame shape as a whole through which the threading hole of the sewing needle that passes through the needle hole of the needle plate can pass through with the opening of the notch closed with the opening / closing body closed. The first clamping part and the second clamping part are formed so that the opening / closing body clamps the thread end part in the closed state of the thread catching part in which the opening of the notch is closed. The drive means is configured such that at least the inside of the yarn catching portion is positioned on the vertical movement path, and the first clamping section and the second clamping section are opposed to both sides via the vertical movement path. And the first clamping part and the second clamping part are spaced apart to the side of the vertical movement path. The upper thread clamping means is configured to be drivable so as to be able to selectively take two positions between the first clamping part and the second clamping part, that is, a clamping position for clamping the thread end. Furthermore, after the upper thread is clamped, the first clamping unit is configured to catch the thread when the tension of the upper thread acts strongly on the opening / closing body and the opening / closing body opens the notch opening by the upper thread. It is in the point which is formed so that it may be in the closed state of a part. And by adopting such a configuration, the tip end side of the thread end of the upper thread clamped between the first clamping part and the second clamping part is sewn into the seam on the back of the fabric, and the thread catching part When the loop passing through is formed, the loop due to the feeding of the fabric as the sewing progresses operates so that the opening / closing body opens the opening of the notch by the force pulling the first clamping part, and the thread catching part is in the open state, The loop and thus the upper thread can be removed from the thread catcher.

  The upper thread gripping device of the sewing machine of the present invention according to claim 2 is characterized in that an upper thread clamping means for capturing and clamping the thread end of the upper thread, and a drive for driving the upper thread clamping means At the beginning of sewing, the thread end of the upper thread inserted through the threading hole of the sewing needle is positioned below the needle plate of the bed and away from the vertical movement path of the sewing needle. In the upper thread clamp device of the sewing machine formed so as to release the thread end portion of the clamped upper thread after the number of stitches that have been preset is dropped after that, The means includes a yarn catching portion including a notch and an opening / closing body arranged to be able to open and close the opening of the notch, and the first clamping portion by a portion of the opening / closing body that closes the opening of the notch The first clamping member formed with a contact and separation relative to the first clamping part And a second clamping member having a second clamping part that clamps the yarn end part with the first clamping part, and the yarn catching part is an opening of the notch Is formed so as to form a frame shape as a whole through which a threading hole of a sewing needle that passes through a needle hole of the needle plate can pass through in a closed state in which the opening / closing body is closed, and the first holding part and the first holding part The two clamping portions are formed so as to clamp the yarn end portion in the closed state of the yarn catching portion in which the opening / closing body closes the opening of the notch, and the driving means includes at least the yarn An initial position in which the inside of the capturing part is located on the vertical movement path and the first clamping part and the second clamping part are opposed to both sides via the vertical movement path, the first clamping part and the first clamping part Two clamping parts are spaced apart from each other in the vertical movement path, and the first clamping part and the second clamping part And the first clamping part and the second clamping part are further spaced apart from the clamping position to the side of the vertical movement path, and the first clamping part and the second clamping part. The upper thread clamping means is configured to be drivable so as to be able to selectively take three positions, a release position for releasing the thread end portion sandwiched between the clamping section and the first clamping section. After the upper thread is clamped, when the upper thread is released, the tension of the upper thread acts strongly on the opening / closing body, and the opening / closing body opens the notch opening by the upper thread. It is in the point which is formed so that it may be in a state. By adopting such a configuration, the thread end is pulled up from the hook, and the leading end side of the thread end of the upper thread that is sandwiched between the first clamping part and the second clamping part is the seam on the back of the fabric. When the loop passing through the thread catching portion is formed, the loop caused by the feeding of the fabric accompanying the sewing progresses so that the opening / closing body opens the notch opening by the force pulling the first clamping portion. The yarn catching portion is opened, and the loop and the upper thread can be removed from the yarn catching portion.

  According to a third aspect of the present invention, the upper thread gripping device of the sewing machine according to the present invention is characterized in that, in the first or second aspect, the opening / closing body normally closes the thread catching portion by the urging force of the urging means. It is in the point formed so that it may be held. By adopting such a configuration, the yarn catching portion can be easily closed, and when the force against the biasing force of the biasing means is applied to the first clamping portion, the yarn catching portion The part can be opened.

  According to a fourth aspect of the present invention, the needle thread clamp device of the present invention is characterized in that, in the third aspect, the urging force adjusting means for adjusting the urging force of the urging means is provided. And by employ | adopting such a structure, the biasing force of a biasing means can be adjusted easily.

  According to the upper thread gripping device of the sewing machine according to the present invention, the front end side of the thread end of the upper thread clamped between the first clamping unit and the second clamping unit is sewn into the seam on the back of the fabric. When a loop that passes through the catching part is formed, the open / close body operates to open the notch opening, the thread catching part is opened, and the loop and the upper thread can be removed from the thread catching part. There is an effect.

  The present invention will be described below with reference to embodiments shown in the drawings.

  A sewing machine to which the upper thread clamp device of the sewing machine of the present embodiment (hereinafter simply referred to as the upper thread clamp device) is applied will be described with reference to FIGS.

(Overall schematic configuration of sewing machine)
As shown in FIG. 1, the sewing machine 1 of the present embodiment includes a bed portion 2 and a connecting cylinder that protrudes upwardly provided at the rear portion of the bed portion 2 shown on the right side of FIG. As a whole, substantially U-shaped including a portion 3 and an arm portion 4 provided so as to extend in parallel with the bed portion 2 from the upper portion of the connecting body portion 3 toward the front shown on the left side of FIG. It is formed in a shape.

  The sewing machine 1 of the present embodiment has a basic configuration of a cylinder bed sewing machine in which the distal end portion of the bed portion 2 is formed in a substantially cylindrical shape, and the width in the X-axis direction described later is set narrower than other portions. It is what it has.

  Here, for convenience of explanation, the vertical movement direction of the sewing needle N, which will be described later, is the Z-axis direction, the longitudinal direction of the bed part 2 and the arm part 4 is the Y-axis direction, and the Z-axis direction and The direction orthogonal to both the Y-axis directions is taken as the X-axis direction.

  When the sewing machine 1 is installed on a horizontal plane, the + side in the Z-axis direction is up, the-side is down, the + side in the X-axis direction is left, the-side is right, and the + side in the Y-axis direction is front. The following explanation will be made with the minus side as the latter.

  The sewing machine 1 is provided at the distal end portion of the arm portion 4, and a sewing needle N that reciprocates in the vertical direction by the driving force of the sewing machine motor 5 (FIG. 17) and an upper portion of the arm portion 4. An upper thread supply source (not shown) for supplying the upper thread T, and the upper thread T is clamped between the upper thread supply source and the sewing needle N with a predetermined load, and resistance to movement in the feeding direction is generated. A thread tension device 6 to be pulled up, a balance device for pulling up the upper thread T by the balance 7 at a predetermined timing between the thread tension device 6 and the sewing needle N, and a sewing needle N Needle plate 8 provided with a needle hole 8a (FIG. 7) through which the tip of the needle thread is inserted, and the needle thread loop TL ( Fig. 5) is picked up and a lower thread (not shown) is inserted into the upper thread loop TL. A hook mechanism 9 provided with a rotary hook, an upper thread gripping device 10 for clamping the thread end TA of the upper thread T when the sewing needle N is raised between the needle plate 8 and the hook mechanism 9; 2, and includes a thread cutting device (not shown) that cuts the upper thread T and the lower thread after sewing, and a control means 11 (FIG. 17) that controls the operation of each unit described later.

  The sewing needle N is formed with a threading hole Na (eye hole: FIG. 7) slightly above the tip shown in FIG. 1, and the upper thread T is inserted into the threading hole Na. ing. Further, the base end portion of the sewing needle N shown in the upper part of FIG. 1 is detachably attached to the lower end portion of the needle bar 12 via a needle clamp (not shown). The needle bar 12 is disposed on the free end side of the arm portion 4 on the left side in FIG. 1, and the lower end portion of the needle bar 12 extends from the lower surface on the free end side of the arm portion 4 to the needle drop of the bed portion 2. The position, more specifically, the needle plate 8 is disposed so as to protrude toward the needle hole 8a. The needle bar 12 is connected to a needle bar driving mechanism (not shown). The needle bar driving mechanism rotationally drives the needle bar 12 with the sewing needle N attached to the lower end portion by the driving force of the sewing machine motor 5. In synchronization with the rotation of the sewing machine main shaft (not shown), it is configured to reciprocate up and down at a predetermined cycle and with a predetermined stroke.

  The sewing machine motor 5 is provided with an encoder 13 (FIG. 17) for detecting the rotational phase angle. The output of the current sewing machine motor 5 is defined as 0 ° when the sewing needle N is located at the top dead center. It is possible to output to the control means 11 which angle position of the axis is 0 to 360 °.

  The balance 7 is provided with a guide hole (not shown) through which the upper thread T is inserted. When the upper thread T is inserted, the balance 7 is moved up and down to be inserted into the threading hole Na of the sewing needle N. The upper thread T is pulled up. The balance device moves the balance 7 up and down at the same cycle as the sewing needle N, but the timing at which the balance 7 is positioned at the top dead center is slightly delayed from the time when the sewing needle N is positioned at the top dead center. Is set.

  As shown in FIG. 8, the shuttle mechanism 9 performs a swinging motion (a reciprocating half-rotating motion in which a half-rotating motion in the forward rotation direction and a half-rotating motion in the reverse rotation direction are alternately repeated) along the circumferential direction. An inner hook 16 that catches the upper thread loop TL by the protruding sword tip 15, a cauldron 17 that rotatably supports the inner hook 16, an upper thread guide plate 18 provided on the upper part of the cauldron 17, and the connecting body 3 side A hook shaft 19 (only a part of which is shown in FIG. 1) is provided extending from the side toward the cauldron 17 in parallel with the longitudinal direction of the bed portion 2 and applying a swing driving force to the inner hook 16 via a driver (not shown). Have.

  The inner hook 16 is formed with rail-like projecting structures 20 along its outer periphery so that the swinging motion can be repeated, and has race surfaces 21 and 22 that are in sliding contact with the support grooves 17a of the cauldron 17 on both sides thereof. Yes. Further, the sword tip 15 is formed at the end of the rail-like protruding structure portion 20, and the thread of the sewing needle N that has entered from the guide hole 18 a of the upper thread guide plate 18 by one half rotation operation of the inner hook 16. The upper thread loop TL can be skimmed by passing immediately next to the through hole Na. For this reason, the tip of the sword 15 is formed in a shape in which the tip thereof is biased in one direction L along the rotation axis RL of the inner hook 16, and the sword tip 15 and the projecting structure 20 are arranged so that It is arranged on the other direction R side along the rotation axis RL with respect to the movement path NL.

  The hook shaft 19 is located on the R side with respect to the inner hook 16 (hereinafter, the direction R side is referred to as the hook shaft side), and is not directly connected to the inner hook 16, but the inner hook 16 A driving force for performing a swinging motion is transmitted to the inner hook 16 via a driver that swings together.

  The hook shaft 19 of the hook mechanism 9 is arranged in parallel to the Y-axis direction, and is positioned on the Y-axis direction negative side with respect to the inner hook 16 and a driving force for swinging the inner hook 16 from this direction. Can be granted. Further, the hook shaft 19 is configured such that the driving force branched from the sewing machine motor 5 is converted into a swinging driving force and transmitted, so that the sewing needle N reciprocates in the vertical direction and the inner hook 16 swings. The dynamic motion is synchronized with a predetermined phase difference.

  The upper thread guide plate 18 has a plate shape for preventing the upper thread T from coming into contact with the race surfaces 21 and 22 of the inner hook 16 and the sliding surface (contact surface) between the cauldron 17 and the race surface 22. As shown in FIG. 5, when viewed from the top indicated by the arrow U in FIG. 8, the end on the Y-axis direction − side widens toward both sides in the X-axis direction, and the end on the Y-axis direction + side A guide hole 18a having a shape expanding toward the X-axis direction-side is provided, and a sword tip 15 of the inner hook 16 is provided at a portion in the X-axis direction-of the central portion of the guide hole 18a in the Y-axis direction. A thread dividing portion 18b is provided for expanding the scooped upper thread loop TL.

  As shown in FIGS. 6 and 7, the upper thread loop TL scooped by the sword tip 15 rotating in the direction indicated by the arrow E in FIG. 7 is connected to the sewing needle N side by the thread dividing portion 18b. The upper thread TF and the upper thread TB on the fabric side are largely separated in the front-rear direction so that the inner hook 16 is prevented from coming into contact with the race surfaces 21 and 22 and being caught.

(Configuration of needle thread clamp device)
The upper thread gripping device 10 reliably forms the stitch S at the start of sewing, that is, in order to prevent the thread end TA of the upper thread T at the start of sewing from being pulled out of the fabric C. The thread end TA of the upper thread T inserted through the sewing needle N is captured and clamped at a position below the needle plate 8 and away from the vertical movement path NL of the sewing needle N, and then set in advance. After the number of stitches has dropped, the thread end TA of the upper thread T that has been clamped is released.

  The upper thread gripping device 10 of the present embodiment includes a first clamping part 24 and a second clamping part 25 that are made relatively close to and separable for capturing and clamping the thread end TA of the upper thread T. A thread clamping unit 26 (hereinafter simply referred to as a clamping unit) and a driving unit 27 for driving the clamping unit 26 are provided. The driving unit 27 further includes a moving unit 28 and a related operation unit 29.

  The moving means 28 has an initial position (FIGS. 8 to 11) positioned on the vertical movement path NL of the sewing needle N, and a vertical movement path NL (parallel to the Z-axis direction) of the sewing needle N from this initial position. A clamping position (FIGS. 12 and 13) spaced rearward (on the connecting body 3 side) with respect to the path connecting the tip position of the sewing needle N at the top dead center to the tip position of the sewing needle N at the bottom dead center , It is possible to move to the release position (FIGS. 14 and 15) spaced further rearward (on the connecting body 3 side) from the clamping position, and move from the initial position to the clamping position at the start of sewing. After stopping for the set number of stitches, the needle is moved from the clamping position to the release position.

  The related operation means 29 is arranged such that when the clamping means 26 is located at the initial position, the second clamping part 25 is disposed at a position closer to the connecting body part 3 than the vertical movement path NL of the sewing needle N and the first clamping part 24. Is arranged at a position opposite to the clamping part 31 across the vertical movement path NL of the sewing needle N, and the first clamping part 24 and the second clamping part 25 are moved when the clamping means 26 moves from the initial position to the clamping position. When the clamping means 26 is moved to the release position, the second clamping part 25 is separated from the first clamping part 24 and is clamped by moving in the approaching direction to clamp the yarn end TA of the upper thread T. The first clamping portion 24 and the second clamping portion 25 are mechanically interlocked with the movement of the moving means 28 so that the yarn end portion TA of the upper thread T is released.

  That is, the drive unit 27 of the present embodiment is configured so that the clamping unit 26 can be operated so as to be able to selectively take the three positions of the initial position, the clamping position, and the release position.

  Here, the upper thread clamp device 10 of the present embodiment will be described in detail below.

(Upper thread clamping means for upper thread clamp device)
2 is a perspective view showing the main overall configuration of the upper thread clamp device, and FIG. 3 is a partially exploded perspective view of FIG.

  As shown in FIGS. 2 and 3, the clamping means 26 of the present embodiment has a first clamping member 31 having a first clamping part 24 and a second clamping member 32 having a second clamping part 25. is doing. Each of these members 31 and 32 has a long plate shape as a whole, and they are overlapped with the second clamping member 32 as the top, and all have their longitudinal directions oriented parallel to the Y-axis direction. Both are supported by the related operation means 29 so that both can slide along the Y-axis direction (front-back direction) in the state.

  Hereinafter, when words indicating directions are used in the description of each part of the clamping means 26, the direction in the state where the clamping means 26 is supported by the related operation means 29 is indicated unless otherwise specified. .

  As shown in an enlarged view in FIG. 4, the first clamping member 31 is provided with a yarn catching portion 33 at a tip portion located on the Y axis direction + side. This thread catching portion 33 has a flat rectangular cutout 34 that is long in the front-rear direction at the front end, and an open / close plate 35 as an opening / closing body that is disposed so that an opening located on the front end side of the cutout 34 can be opened and closed. And. The thread catching portion 33 has a frame shape as a whole through which the threading hole Na of the sewing needle N passing through the needle hole 8a of the needle plate 8 can pass in the closed state in which the opening of the notch 34 is closed by the opening / closing plate 35. It is formed to make. Further, the first clamping portion 24 is formed by a portion of the opening / closing plate 35 that closes the opening of the notch 34.

  On the distal end side of the side surface of the first clamping member 31 located on the −X-axis direction −side, an opening / closing plate mounting plate 36 having a substantially triangular shape extends so as to protrude toward the X-axis direction−side. The lower end of the opening / closing plate support member 37 is attached to the upper surface of the opening / closing plate mounting plate portion 36. A base end portion of the opening / closing plate 35 is rotatably supported by the opening / closing plate support member 37. A torsion coil spring 38 as an urging means is attached to the opening / closing plate support member 37. The torsion coil spring 38 is disposed on the upper surface side of the opening / closing plate 35, one end is hooked on a locking groove 39 formed in the opening / closing plate 35, and the other end is above the upper surface of the opening / closing plate mounting plate portion 36. It is hung on the outer periphery of a pin-shaped spring hanging body 40 projecting toward. The opening / closing plate 35 is a side surface of the rectangular bar-shaped blocking portion 35a formed on the distal end side of the opening / closing plate 35 at the normal side in the Y-axis direction in FIG. 4 due to the biasing force (tension) of the torsion coil spring 38. Is brought into contact with the open end of the notch 34. As a result, the yarn catcher 33 can be held closed. Furthermore, the portion (the portion sandwiched between the portions that are in contact with both opening ends) of the side surface of the closing portion 35a that faces the Y-axis direction in FIG. The opening of the notch 34 is a part that closes the opening, and the first clamping part 24 that is used when the upper thread T is clamped is formed by this part. That is, the first clamping part 24 forms a part of the closing part 35 a of the opening / closing plate 35. Furthermore, the front end of the blocking portion 35a is a rounded portion 41 formed in a planar semicircular shape, a planar arc shape, or the like.

  It should be noted that rounded chamfering is provided on each of the upper edge and the lower edge located on the side facing the notch 34 of the closing portion 35a, as will be described later, from the closing portion 35a, that is, the first clamping portion 24. It is preferable in the sense that the thread breakage can be prevented when the loop W comes out while contacting.

  Therefore, the opening / closing plate 35 is formed so as to hold the yarn catching portion 33 in the closed state by the urging force of the torsion coil spring 38 at all times.

  The biasing force of the torsion coil spring 38 held by the opening / closing plate 35 so as to block the opening of the notch 34 is formed to be larger than the force (load) at which the second clamping portion 25 described later contacts the first clamping portion 24. Has been.

  Of course, when a load greater than the biasing force of the torsion coil spring 38 is applied to the first clamping portion 24 constituting a part of the opening / closing plate 35 in the direction from the inside toward the outside, the opening / closing plate 35 is The thread catching portion 33 is movably formed with the opening / closing plate support member 37 as the center.

  That is, as will be described later, the thread end TA of the clamped upper thread T becomes a loop W and does not come off from the clamping means 26, and the fabric C is fed due to an increase in the number of needles, and high tension is applied to the upper thread T. In some cases, the tension of the upper thread T is applied to the first clamping unit 24 so that the first clamping unit 24 and thus the opening / closing plate 35 can operate so as to open the opening of the notch 34.

  Therefore, after the upper thread T is clamped, the first clamping part 24 is formed to be movable so that the thread catching part 33 in which the opening / closing plate 35 opens the opening of the notch 34 is closed by the upper thread.

  A plurality of spring hanging bodies 40 to which the other end of the torsion coil spring 38 is hung are provided in the present embodiment, and the urging force of the torsion coil spring 38 can be adjusted.

  A biasing force adjusting means 42 for adjusting the biasing force of the torsion coil spring 38 as the biasing means of the present embodiment is configured by providing a plurality of spring hanging bodies 40, two in the present embodiment. .

  The notch 34 of the present embodiment is formed to function also as a guide for guiding the movement of the second clamping part 25 of the second clamping member 32 in the front-rear direction.

  Note that the shape of the notch 34 may be a shape other than a flat rectangular shape, for example, a substantially U shape with a substantially arc-shaped or semicircular bottom, depending on the design concept and the like. The shape is not limited to a planar rectangular shape.

  Further, the closing portion 35a is not limited to a square bar shape, but may be a round bar shape having a circular cross section or a square bar shape having a polygonal cross section. However, rounding the tip is preferable in the sense that thread breakage can be prevented.

  As shown in FIGS. 3 and 4, a flat rectangular through-hole 43 that is long in the front-rear direction is formed at the rear end of the first clamping member 31 located on the negative side in the Y-axis direction. In this through hole 43, a tension spring 44 of the related operation means 29, which will be described later, is arranged to form an operation region for expanding and contracting. One end of a tension spring 44 is connected to the front end of the through hole 43. In addition, a bracket portion 45 extending toward the X-axis direction − side is provided at a position slightly rearward of the first clamping member 31 in the Y-axis direction, and the tip portion extends downward. A protruding round bar-like engagement pin 46 is fixedly mounted with its tip directed downward. The first clamping member 31 is formed such that a moving force in the front-rear direction by the related operation means 29 is input via the engagement pin 46.

  As shown in FIG. 3, the second clamping member 32 is divided into a front side portion 48 and a rear side portion 49, and these are connected to each other by a connecting body 50 so as to be formed into an integral substantially long plate shape. Has been. A second clamping unit 25 is provided at the front end portion of the front side portion 48, and the second clamping unit 25 is connected to the first clamping unit 24 constituting a part of the closed yarn catching unit 33. A holding surface 25a that can contact and separate from the first holding portion 24 and a bent portion 25b that passes below the first holding portion 24 and protrudes forward from the front end surface of the first holding member 31 when contacting the first holding portion 24. is doing.

  Therefore, the upper thread T inserted from above into the yarn catching part 33 of the first clamping member 31 is moved from the first clamping part 24 to the first clamping part 33 by the relative approaching action of the first clamping member 31 and the second clamping member 32. 2 It is formed so that it can be clamped by the clamping surface 25 a of the clamping unit 25. Further, the clamped upper thread T is bent forward by a bent portion 25b extending forward from the lower end of the clamping surface 25a, so that the upper thread T is not lowered from the front to the lower. Be able to. As a result, the yarn end portion TA of the upper thread T hangs down in a state of being more forwardly positioned by the bent portion 25b, so that the position thereof is shifted further forward than the intermediate hook 16 of the hook mechanism 9 positioned below the upper end. Thus, it is formed so as to be able to prevent contact and entrainment with the inner hook 16.

  In addition, as the 1st clamping part 24 and the 2nd clamping part 25, the shape which can contact | abut the clamping surface 25a of the 1st clamping part 24 and the 2nd clamping part 25 via the upper thread T, for example, planar arc shape It may be formed in a curved shape.

  The rear side portion 49 has a through hole 51 formed along the front-rear direction. When the second holding member 32 and the first holding member 31 are overlapped with each other and supported by the related operation means 29, the rear side portion 49 has a through hole. 51 overlaps with the through hole 43 of the first clamping member 31 described above, and the tension spring 44 of the related operation means 29 is arranged inside these to form an operation region for expanding and contracting. The other end of the tension spring 44 is connected to the rear end of the through hole 51.

  Accordingly, the second clamping member 32 is connected to the first clamping member 31 via the tension spring 44, and the first clamping part 24 of the first clamping member 31 and the second clamping part 25 of the second clamping member 32 are connected to each other. The urging force is always applied in a direction in which they approach each other and come into contact with each other.

  A bracket portion 52 extending toward the + side in the X-axis direction is provided at an intermediate portion in the Y-axis direction of the rear side portion 49 of the second clamping member 32, and extends downward at the tip portion. A round bar-like engagement pin 53 is fixedly mounted with its tip facing downward. Then, the moving force in the front-rear direction by the related operation means 29 is input to the second clamping member 32 via the engagement pin 53.

(Moving means of upper thread holding device)
The moving means 28 moves with respect to the first clamping part 24 and the second clamping part 25 of the clamping means 26 in advance to an initial position (FIG. 8) below the vertical movement path NL of the sewing needle N before the start of sewing. After the start of sewing, when the first sewing needle N is pulled out of the fabric, the sewing needle N is moved to a holding position (FIG. 12) which is behind the initial position with respect to the vertical movement path NL of the sewing needle N. When the preset number of needle drops has been performed (for example, 2 to 3 stitches), the sewing needle N is moved to a release position (FIG. 14) that is behind the clamping position with respect to the vertical movement path NL of the sewing needle N. To move to.

  Therefore, the moving means 28 includes a Y-axis moving mechanism 55 that reciprocates the holding means 26 supported by the related operation means 29 along the Y-axis direction, and the holding means 26 is in any of the initial position, the holding position, and the release position. A moving position detecting means 56 for detecting whether or not the position is present, and a moving positioning control means for controlling the operation of the Y-axis moving mechanism 55 based on the detection of the moving position detecting means 56 are provided.

  As shown in FIG. 3, the Y-axis moving mechanism 55 has a thread clamp motor 58 that outputs a rotational driving force as a drive source of the drive means 27, and an output shaft of the thread clamp motor 58. The main link body 59 connected in position, the driven link body 61 that applies a moving force in the Y-axis direction to the relative position adjustment link body 60 of the related operation means 29, and the driving force from the main link body 59 to the driven link body 61. The transmission link body 62 which transmits is provided.

  As the thread gripping motor 58, for example, a stepping motor is used, and is driven at an arbitrary rotation angle amount in the forward and reverse directions by the operation control of the control means 11.

  One end of the main link 59 is fixedly connected to the output shaft of the thread clamp motor 58, and the other end is rotatably connected to one end of the transmission link 62.

  One end of the driven link body 61 is pivotally supported by a guide plate 63 (to be described later) of the related operation means 29, and the other end is rotatably connected to the other end of the transmission link body 62. The substantially U-shaped follower link body 61 is provided with an engagement protrusion 64 for applying a moving force along the Y-axis direction to the relative position adjustment link body 60 of the related operation means 29.

  The transmission link body 62 is disposed substantially along the Y-axis direction, and is configured to swing the driven link body 61 along with the swing of the main link body 59 driven by the thread clamp motor 58.

  With these configurations, when the thread clamp motor 58 is driven, the driven link body 61 swings along with the swing of the main link body 59, and the relative position adjustment link body 60 of the related operation means 29 moves through the engagement protrusion 64. It is formed so as to move along the axial direction.

  The moving position detecting means 56 will be described with reference to FIGS. 10, 13, and 15. FIG. In FIGS. 2 and 3, the movement position detecting means 56 is not shown. 10 is a bottom view when the clamping means 26 is located at the initial position, FIG. 13 is a bottom view when the clamping means 26 is located at the clamping position, and FIG. 15 is a perspective view when the clamping means 26 is at the release position. It is a bottom view when it is located.

  The moving position detecting means 56 includes a light emitting element and a light receiving element, and first and second state sensors 66 and 67 for detecting the presence / absence of a shield between them, and the Y-axis moving mechanism described above. And a shielding plate 70 having first and second shielding regions 68 and 69, which are provided on 55 transmission link bodies 62.

  The first and second state sensors 66 and 67 are arranged side by side along the movement line of the shielding plate 70, and the first state sensor 47 is arranged on the rear side. Thereby, each state sensor 66 and 67 will be in the state located in a line along the Y-axis direction substantially. The light receiving elements of the state sensors 66 and 67 are configured to turn on a state with a shielding object, turn off a state without a shielding object, and output a signal that can identify each state to the control unit 11. .

  On the other hand, the shielding plate 70 is fixedly supported by the transmission link body 62 so as to pass between the light emitting element and the light receiving element with respect to both the first and second state sensors 66 and 67. As shown in FIG. 10, the first shielding area 68 is located between the first state sensor 66 and the second state sensor 67 when the holding means 26 is in the initial position, and is shown when it is in the holding position. 13 in the position where the first state sensor 66 is shielded, and when in the release position, the position in the Y-axis direction and the position where the first state sensor 66 is still shielded as shown in FIG. The length in the Y-axis direction is set.

  As shown in FIGS. 10 and 13, the second shielding area 69 is positioned in front of the second state sensor 67 in any case when the clamping means 26 is in the initial position or the clamping position. The Y-axis direction position is set so that the second state sensor 67 is shielded for the first time as shown in FIG. 15 when in the release position.

  Therefore, the control means 11 can determine that the clamping means 26 is in the initial position because both the first and second state sensors 66 and 67 are in the OFF state, and that the clamping means 26 is in the clamping position. It can be determined from the fact that the first state sensor is in the ON state and the second state sensor 67 is in the OFF state, and both the first and second state sensors 66 and 67 are in the ON state that the clamping means 26 is in the release position. It can be determined from the state.

  The movement positioning control means will be described. This movement positioning control means is actually realized by the control of the control means 11. Thus, the movement positioning control means may be realized by borrowing a part of the function of the control means 11 for controlling the operation of the entire sewing machine, or may be realized by an independent control means.

  The control means 11 as the movement positioning control means previously determines the rotation angle amount of the thread gripping motor 58 for moving the clamping means 26 from the initial position to the clamping position and the rotation angle amount for moving from the clamping position to the release position. When the holding means 26 is positioned at the second and release positions, the operation of the thread clamp motor 58 is controlled with reference to the stored angular position.

  As for the initial position, the control means 11 performs control (initialization operation processing) as an initial position control section using the moving position detection means 56 when the main power of the sewing machine 1 is turned on, and drives the thread clamp motor 58. Then, the position where both the first and second state sensors 66 and 67 are in the OFF state is searched, and it is configured to stand by at that position.

  When the encoder 13 of the sewing machine motor 5 detects that the output shaft angle is 245 °, for example, at the first stitch after the start of sewing, it recognizes that the sewing needle N has been pulled upward from the fabric C and holds the clamping means 26. Control is performed as an upper thread holding control unit that positions the holding position.

  In the sewing machine 1 of the present embodiment, when the top dead center position of the sewing needle N is set to 0 ° with respect to the output shaft of the sewing machine motor 5, when the sewing needle N rotates to 245 °, the sewing needle N passes through the bottom dead center. It is set so as to come out above the plate 8. Further, when a predetermined number of needle drops after the start of sewing is detected by the output of the encoder 13, control as an upper thread release control unit that positions the clamping means 26 at the release position is performed. Here, the number of stitches is recognized by the output of the encoder 13, for example, by counting the number of signal outputs indicating 180 ° by the encoder 13.

(Related operation means of upper thread holding device)
The related operation means 29 will be described with reference to FIGS.

  The related operation means 29 includes a guide plate 63 as a guide means for reciprocally supporting the second clamping member 32 and the first clamping member 31 along the Y-axis direction, and the second clamping part 25 and the first clamping unit. A tension spring 44 as a tension urging means for always applying tension between the second clamping member 32 and the first clamping member 31 in a direction in which the portion 24 approaches each other, and in response to a change in posture due to its own swinging The second clamping part 25 and the first clamping part 24 can be brought into contact with and separated from each other, and are engaged with the second clamping member 32 and the first clamping member 31, respectively. When the relative position adjusting link body 60 to which the moving force is input and the holding means 26 are in the initial position, the second holding section 25 and the first holding section 24 are brought into contact with the relative position adjusting link body 60 to contact with each other. Swing in the direction of separation When the first abutting member 72 and the clamping means 26 are in the release position, the first abutting member 72 abuts on the relative position adjustment link body 60 and swings in a direction to separate the second clamping unit 25 and the first clamping unit 24. And a second abutting member 73 to be moved.

  The guide plate 63 is fixed on the upper portion of the bed portion 2 and behind the needle plate 8.

  Hereinafter, when words indicating directions are used in the description of each part of the related operation means 29, the direction in the state where the guide plate 63 is fixedly mounted on the bed part 2 is indicated unless otherwise specified. To do.

  On the upper surface of the guide plate 63, a guide groove 75 along the Y-axis direction is provided at an intermediate position in the X-axis direction. In this guide groove 75, the first clamping member 31 and the second clamping member 32 of the clamping means 26 are stored in a state where they are overlapped in the longitudinal direction, and a pressing plate 76 is further provided on the first clamping member 31 from above. The second clamping member 32 is covered so as not to fall off the guide groove 75. Thereby, the first clamping member 31 and the second clamping member 32 are guided by the guide groove 75 and can slide along the Y-axis direction.

  However, as described above, since the first clamping member 31 and the second clamping member 32 are connected via the tension spring 44, each member 31, 32 is connected to the first clamping portion 24 unless an external force is applied. The state where the second clamping unit 25 is in contact with the second clamping unit 25 is maintained.

  Through holes 77 and 78 are provided on both sides of the guide plate 63 with the guide groove 75 in between. In one through hole 77, the engagement pin 46 provided in the first clamping member 31 is fitted from above, and in the other through hole 78, the engagement pin 53 of the second clamping member 32 is fitted. Further, each of the through holes 77 and 78 is an engagement pin in the movement from the initial position to the release position of the holding means 26 and the relative movement of the first holding member 31 and the second holding member 32 accompanying this. The length in the Y-axis direction is set so that the front and rear ends of the holes 77 and 78 do not contact 46 and 53, respectively. The engaging pins 46 and 53 inserted through the through holes 77 and 78 have their tips protruding somewhat from the lower surface side of the guide plate 63 and individually engaged with the relative position adjusting link body 60.

  The relative position adjustment link body 60 is arranged along the longitudinal direction thereof, and the rotation engagement portion 79 with the first clamping member 31, the rotation engagement portion 80 with the second clamping member 32, A rotation engaging portion 81 with the moving means 28 located between them is provided.

  That is, the rotation engagement portion 79 with the first clamping member 31 is a long hole-like through hole along the longitudinal direction of the relative position adjustment link body 60, and the engagement pin 46 is inserted therethrough. The rotation engagement portion 80 with the second clamping member 32 is a circular through hole, and the engagement pin 53 is inserted therethrough. The rotation engaging part 81 with the moving means 28 is a long hole-like through hole along the longitudinal direction of the relative position adjusting link body 60, and the engaging protrusion 64 is inserted therethrough.

  FIG. 16 is an explanatory diagram viewed from below showing the relationship between the swinging operation of the relative position adjusting link body 60 and the changes in the response positions of the first clamping member 31 and the second clamping member 32.

  As shown in FIG. 16, as described above, the first clamping member 31 and the second clamping member 32 are in contact between the first clamping part 24 and the second clamping part 25 by the tension spring 44 as long as no external force is applied. Is maintained.

  At this time, with respect to the contact force between the first clamping part 24 and the second clamping part 25 by the tension spring 44, the opening / closing plate 35 by the torsion coil spring 38 and the tip of the first clamping member 31 (the opening end of the notch 34) The abutting force that abuts is set to a sufficiently large load. This state is a state where the upper thread T is clamped. The positions of the engagement pins 46 and 53 are set so that they are aligned at substantially the same position in the Y-axis direction when the first clamping unit 24 and the second clamping unit 25 are in contact with each other.

  Therefore, the relative position adjustment link body 60 connected to the engagement pins 46 and 53 via the rotation engagement portions 79 and 80 is also substantially in the X-axis direction in the normal state due to the biasing force of the tension spring 44. Is maintained (the state indicated by the solid line in FIG. 16).

  Further, in this state, for example, when a counterclockwise rotational force is applied to the relative position adjustment link body 60 by the Y-axis direction movement force from the engagement protrusion 64 of the moving means 28, the relative position adjustment link body 60. Swings and changes its posture. At this time, the rotation engaging portions 79 and 80 are displaced in the Y-axis direction, so that the first clamping portion 24 and the second clamping portion 25 are interposed between the first clamping member 31 and the second clamping member 32. The external force in the direction in which they are separated from each other is applied.

  Accordingly, the first clamping portion 24 and the second clamping portion 25 are separated from each other against the tension of the tension spring 44 and are switched from the holding state of the upper thread T to the released state.

  The first contact member 72 will be described with reference to FIGS.

  The first abutting member 72 separates the first clamping unit 24 and the second clamping unit 25 when the clamping unit 26 is in the initial position, and the first clamping member 72 is moved to the clamping position from the initial position. The part 24 and the second clamping part 25 are moved in a direction in which they approach each other, and the relative position adjusting link body 60 is operated to swing so as to come into contact with each other until reaching the clamping position.

  In order to realize such an operation, the first abutting member 72 is connected to the rotation engaging portion 81 of the moving means 28 and the second clamping member 32 with respect to the relative position adjusting link body 60 located at the initial position. It arrange | positions so that it may contact | abut from the front between this rotation engaging part 80. With this arrangement, when the forward movement force is applied to the relative position adjustment link body 60 by the movement means 28 in order to position the clamping means 26 at the initial position, the relative position adjustment link body 60 is pulled by the tension spring. Oscillates with the contact point with the first contact member 72 as a fulcrum against the tension of 44. At that time, the rotational engagement portion 80 of the second clamping member 32 moves rearward and the rotational engagement portion 79 of the first clamping member 31 moves forward as compared with the contact time.

  Accordingly, the first clamping part 24 moves forward via the first clamping member 31 and the second clamping part 25 moves rearward via the second clamping member 32, so that they are separated from each other (FIG. 16). Two-dot chain line). In this state, the upper thread T is inserted between the first clamping part 24 and the second clamping part 25.

  When the clamping means 26 moves from the initial position to the clamping position, the contact state of the first contact member 72 with the relative position adjustment link body 60 is gradually released, so the relative position adjustment link body 60 is The tension spring 44 rotates clockwise.

  Accordingly, the relative position adjustment link body 60 rotates clockwise until the contact state with the first contact member 72 is completely released, and the second sandwiching portion 25 moves forward via the second sandwiching member 32. And the first clamping part 24 moves rearward via the first clamping member 31. For this reason, the upper thread T is clamped by the first clamping unit 24 and the second clamping unit 25 behind the first clamping unit 24 at the initial position and ahead of the second clamping unit 25 at the initial position. Will be done in position.

  The second contact member 73 will be described with reference to FIGS.

  The second abutting member 73 moves the first clamping part 24 and the second clamping part 25 that are in the clamping state when the clamping means 26 moves from the clamping position to the release position so as to separate them again. The relative position adjusting link body 60 is formed to operate swinging.

  In order to realize such an operation, the second abutting member 73 has an X-axis direction with respect to a region through which the relative position adjustment link body 60 passes when the clamping means 26 moves from the clamping position to the release position. It arrange | positions so that the said relative position adjustment link body 60 may be slidably contacted from the side.

  For this reason, the second position relative to the sliding contact portion 60a provided at the end portion on the X axis direction minus side of the relative position adjustment link body 60 that approaches the release position in a state substantially along the X axis direction (FIG. 13). The contact member 73 is in sliding contact. Since the sliding contact portion 60a of the relative position adjusting link body 60 has a shape in which the front side is gradually extended in the X axis direction minus side, the relative position adjusting link body 60 moves further rearward after the sliding contact starts. Thus, the relative position adjusting link body 60 swings counterclockwise as shown in FIG. 15, and in this state, the clamping means 26 reaches the release position. By this swinging, the rotational engagement portion 80 of the second clamping member 32 moves rearward more greatly than the rotational engagement portion 79 of the first clamping member 31. As a result, the first clamping part 24 and the second clamping part 25 are separated from each other (FIG. 15), and the yarn end of the upper thread T held between the first clamping part 24 and the second clamping part 25 The part TA is released.

(Arrangement of holding part and clamping part at each moving position)
As described above, when the clamping means 26 is moved and positioned to the initial position, the first clamping part 24 and the second clamping part 25 move in directions away from each other. When the initial position is reached, the first clamping portion 24 is positioned in front of the vertical movement path NL of the sewing needle N as shown in FIG.

  Further, the distal end portion of the bent portion 25b of the second sandwiching portion 25 is positioned at least on the rear side of the straight line M. This straight line M is a sewing needle from the rear side edge at the lower end of the needle hole 8a (the position that becomes the Y-axis direction-side end of the diameter along the Y-axis direction of the circular needle hole 8a as viewed from below). This is a straight line determined by connecting the upper end portion of one race surface 128 on the rear side of the inner hook 16 disposed close to the rear side of the N vertical movement path NL.

  By setting the tip portion of the second clamping portion 25 in this way, the upper thread loop TL by the first stitch in sewing is captured by the sword tip 15 of the inner hook 16 and widened by the thread dividing portion 18b of the upper thread guide plate 18. When being extended (expanded), the tip of the second clamping portion 25 contacts the upper thread T, and the yarn dividing section 18b is not prevented from expanding the upper thread loop TL. It is possible to effectively suppress contact with 22.

  Note that the position of the first clamping part 24 and the tip position of the second clamping part 25 are the first abutting member with respect to the length in the Y-axis direction of the first clamping member 31 and the second clamping member 32 and the relative position adjustment link body 60. 72 is determined by the contact position. For example, if the contact position of the first contact member 72 is closer to the rotational engagement portion 81 of the moving means 28, the position of the first holding member 31 is more forward and the tip position of the second holding portion 25 is more forward. Be behind. Further, if the contact position is closer to the rotational engagement portion 80 of the second clamping member 32, the position of the first clamping portion 24 is further rearward, and the tip position of the second clamping portion 25 is more forward.

  The initial position may be a position where the yarn catcher 33 is positioned on the vertical movement path NL and the first clamping part 24 and the second clamping part 25 are opposed to both sides via the vertical movement path NL. .

  As shown in FIG. 13, the clamping position of the clamping means 26 is in the vicinity of the vertical movement path NL of the sewing needle N, and is preferably closer. This is because the length of the thread end TA of the upper thread T hanging from the clamping means 26 can be shortened by clamping the thread end TA of the upper thread T at a position close to the sewing needle N. .

  FIG. 13 is a diagram showing an example of a clamping position where the yarn end TA of the upper thread T is clamped. The clamping position is located slightly on the side of the vertical movement path NL of the sewing needle N. In the present embodiment, both the first clamping part 24 and the second clamping part 25 are configured to move, and when the sewing needle N is on the vertical movement path NL below the needle plate 8, the first clamping part 24 and the second clamping part 25 move together. Since the clamping part 24 and the second clamping part 25 can be positioned at positions where they do not interfere with the vertical movement of the sewing needle N, the clamping position is further brought closer to the vertical movement path NL of the sewing needle N, for example, the vertical movement of the needle It is also possible on the route NL.

  Further, the distance from the clamping position to the vertical movement path NL of the sewing needle N is also determined by the contact position of the first contact member 72 with respect to the relative position adjustment link body 60. For example, if the contact position of the first contact member 72 is close to the rotation engagement portion 81 of the moving means 28, the holding position is closer to the vertical movement path NL, and the contact position is the second holding member 32. If it is close to the rotation engaging portion 80, the holding position is far from the vertical movement path NL.

  As the clamping position, the first clamping part 24 and the second clamping part 25 are separated from each other in the vertical movement path NL, that is, the first clamping part 24 and the second clamping part 25 are moved up and down by the sewing needle N. Any position that deviates from the path NL and does not interfere with the sewing needle N may be used.

  When the clamping means 26 is moved to the release position and positioned, the first clamping part 24 and the second clamping part 25 may be separated by a distance that allows the upper thread T to be released.

  The release position may be a position where the first clamping part 24 and the second clamping part 25 are separated from the vertical movement path NL of the sewing needle N and do not interfere with the sewing needle N. It is set behind the clamping position so as not to interfere with the mechanism.

  Further, the yarn end TA of the upper yarn T may be clamped while moving from the initial position to the clamping position.

  Furthermore, it may be configured such that both the pinching and releasing of the yarn end TA of the upper thread T are performed at the same position as the pinching position, that is, the pinching position, without providing the release positions individually.

(Control means)
As shown in FIG. 15, although not shown in detail, the control means 11 stores a CPU (which may be an MPU) for performing various arithmetic processes and various programs for various processes such as control and determination, It has a stored ROM and a RAM used as a work memory in various processes. The control means 11 includes a sewing machine motor 5, an encoder 13, a thread clamp motor 58, a thread trimming motor 83 of the thread trimming device, and a first state sensor of the moving position detecting means 56 via a system bus and a drive circuit. 66, a second state sensor 67, a start / stop switch 84 for inputting the start and stop of sewing, and the like are connected.

  The control means 11 can recognize the rotation angle of the sewing machine motor 5 based on the pulse signal input from the encoder 13 provided on the output shaft of the sewing machine motor 5.

  Further, the control means 11 can confirm each movement position of the clamping means 26 based on detection signals input from the first state sensor 66 and the second state sensor 67.

  Further, when the sewing start signal is input from the start / stop switch 81, the control means 11 is controlled by the drive means 27 in accordance with the detected rotation angle of the sewing machine motor 5 and the detection of the operation position of the movement position detection means 46. The drive of the thread clamp motor 58 as a drive source can be controlled.

  As the driving means 27, instead of the moving means 28 and the related operation means 29, the entire clamping means 26 is moved to the initial position, the clamping position, and the release position by the driving force of the first actuator (the initial position and the clamping position). 2), and the first clamping unit 24 and the second clamping unit 25 are moved relative to each other by the driving force of the second actuator. You may use together with the structure to make.

  Next, the operation of the present embodiment having the above-described configuration will be described with reference to FIGS.

  FIG. 16 is a flowchart for explaining the operation in the embodiment of the sewing machine provided with the upper thread clamp device according to the present invention.

(Description of sewing machine operation)
As shown in FIG. 16, in the control means 11, the initial position is detected by the movement position detection means 56 based on the sewing start signal from the start / stop switch 84 (step S1). This detection is determined by whether or not both the first and second state sensors 66 and 67 are in the OFF state.

  As described above, in the operation control, the clamping means 26 is positioned at the initial position by the movement position detecting means 56 when the main power source (not shown) is input. Therefore, the clamping means 26 is located on the vertical movement path NL of the sewing needle N, the first clamping part 24 is located in front of the vertical movement path NL of the sewing needle N, and the second clamping part 25 is behind the straight line M. (The state shown in FIGS. 8 to 11). In addition, if any of the first or second state sensors 66 and 67 is detected to be in an ON state due to some factor despite being previously positioned at the initial position, error processing (display, warning, etc.) is performed. (Step Sa1), the operation of each part of the sewing machine 1 is stopped (step Sa2), and the process is terminated.

  On the other hand, when the first or second state sensors 66 and 67 are both detected to be OFF in step S1, the sewing machine motor 5 starts to be driven (step S2). As a result, the sewing needle N passes through the needle hole 8a of the throat plate 8, and the upper thread T passes inside the thread catching section 33 that is closed and between the first clamping section 24 and the second clamping section 25. pass. Further, below that, the upper thread loop TL beside the sewing needle N is captured by the sword tip 15 of the shuttle mechanism 9. Then, the upper thread loop TL is widened by the rotation of the inner hook 16 and the upper thread guide plate 18, but at this time, the tip end portion of the second clamping portion 25 is positioned sufficiently rearward, so that the upper thread guide plate 18 Does not block the expansion of the upper thread loop TL. Therefore, the upper thread T is prevented from contacting the race surface 22 located rearward.

  Further, it is judged from the detection angle of the encoder signal whether or not the first sewing needle N has come out of the fabric C from the encoder 13 of the sewing machine motor 5 and the balance 7 has reached the top dead center (step S3). The process of step S3 is repeated until the set angle is reached. When the output of the encoder 13 indicates that the balance 7 has reached top dead center, the control means 11 starts driving to move the clamping means 26 to the clamping position by the thread gripping motor 58 of the moving means 28. Control is performed (step S4). That is, referring to the storage of the rotation angle amount corresponding to the movement amount from the initial position to the clamping position set in advance, the thread gripping motor 58 is driven in accordance with this.

  Thereby, the clamping means 26 starts to move from the initial position toward the clamping position. As a result, the relative position adjustment link body 60 of the related operation means 29 starts to swing along the X-axis direction by the urging force of the tension spring 44, so that the first clamping portion 24 moves rearward and the second clamping The part 25 moves forward.

  The thread end TA of the upper thread T is clamped by the first clamping part 24 and the second clamping part 25 after the balance 7 reaches the top dead center because the balance 7 with respect to the upper thread T is at the top dead center of the scale 7. The upper thread T located below the needle hole 8a is in the shortest state because the pulling of the upper thread T is completed. When the upper thread T is clamped by the first clamping part 24 and the second clamping part 25 at this time, the upper thread T is clamped. This is because the “thread end length” that is the length of the upper thread T from the portion to the end can be made the shortest.

  Next, when the thread gripping motor 58 is driven and stopped for a preset rotation angle amount, the clamping means 26 reaches the clamping position, and the first clamping part 24 moves rearward and the second The clamping part 25 moves forward, approaches each other, and the clamping surfaces 25a of the first clamping part 24 and the second clamping part 25 come into contact with each other (state shown in FIGS. 12 and 13). Thereby, the yarn end portion TA of the upper yarn T inserted between them is clamped. In practice, the clamping surface 25a of the first clamping part 24 and the second clamping part 25 is brought into contact with the clamping means 26 while it reaches the clamping position.

  Next, when the thread gripping motor 58 corresponding to a preset rotation angle amount is driven and stopped, the control means 11 confirms the outputs of the state sensors 66 and 67 of the moving position detecting means 56 (step). S5).

  In the clamping position, the first state sensor 66 is in the ON state and the second state sensor 67 is in the OFF state, but any other state is detected for any one of the sensors 66 and 67. In this case, error processing (display, warning, etc.) is performed (step Sa1), the operation of each part of the sewing machine 1 is stopped (step Sa2), and the processing is terminated.

  If the sensors 47 and 48 indicate an appropriate state in step S5, the sewing is continued while the upper thread T is held between the holding members 20. That is, the sewing machine 1 performs sewing for the second and subsequent stitches (step S6). The movement to the clamping position is completed while the needle tip of the sewing needle N is above the needle plate 8.

  Next, the control unit 11 determines whether or not a preset number of needle drops (for example, two needle drops) has been performed (step S7). The number of needle drops can be recognized by, for example, counting the number of signal outputs indicating 180 ° by the encoder 13.

  When the control means 11 determines that the predetermined number of needle drops has not been performed (step S7: NO), the process of step S7 is repeated until a predetermined number of needle drops are performed.

  On the other hand, when the control means 11 determines that a predetermined number of needle drops have been performed (step S7: YES), the process proceeds to step S8.

  The control means 11 performs operation control to start driving so that the thread gripping motor 58 of the moving means 28 moves the clamping means 26 to the release position (step S8). That is, referring to the storage of the rotation angle amount corresponding to the preset movement amount from the clamping position to the release position, the thread clamp motor 58 is driven in accordance with this.

  Thereby, the clamping means 26 starts to move from the clamping position toward the release position. Then, the sliding contact portion 60 a of the relative position adjustment link body 60 of the related operation means 29 comes into sliding contact with the second contact member 73 while the sandwiching means 26 approaches the release position. When the movement of the clamping means 26 is further continued, the relative position adjusting link body 60 swings against the urging force of the tension spring 44, and the second clamping part 25 is largely rearward than the first clamping part 24. Moving. Accordingly, the clamping state of the yarn end TA of the upper yarn T is released, and the clamping end 26 reaches the release position while the yarn end TA of the upper yarn T is released from the clamping unit 26 (see FIGS. 14 and 15). Status).

  When the clamping means 26 reaches the release position, the control means 11 confirms the outputs of the state sensors 66 and 67 of the movement position detection means 56 (step S9). In the release position, the first state sensor 66 is in the ON state and the second state sensor 67 is in the ON state, but any other state is detected for any one of the sensors 47 and 48. Therefore, the control unit 11 determines that the clamping unit 26 has not reached the release position, and repeats the process of step S8 until both the sensors 47 and 48 are turned on.

  Next, the control means 11 determines whether or not sewing has been completed (step S10). When the control means 11 determines that the sewing has not been completed (step S10: NO), the process of step S10 is repeated until the sewing is completed.

  On the other hand, when the control means 11 determines that the sewing has been completed (step S10: YES), the process proceeds to step S11.

  When the sewing is completed, the control means 11 outputs a drive signal to the thread trimming motor 82 of the thread trimming mechanism, and the threads (upper thread T and lower thread) used for the sewing by the thread trimming mechanism by the driving force of the thread trimming motor 82. ) Is performed (step S11).

  Then, the control means 11 outputs a drive signal to the thread clamp motor 58 of the moving means 28, and the clamping means 26 returns from the release position to the initial position by the drive force of the thread clamp motor 58 (step S12).

  Then, through the process of step S1 and the process of step S12 (including the processes of step Sa1 and step Sa2), one cycle related to sewing of the sewing machine 1 including the upper thread clamp device 10 is completed.

  When the clamping means 26 is configured to release the upper thread T at the clamping position, the steps S7 to S9 are omitted.

  The above description is the basic operation of the clamping means 26 at each moving position when the “thread end length” of the upper thread T is short, and is useful for improving the quality of the sewing product at the start of sewing.

  Incidentally, when the “thread end length” of the upper thread T clamped by the clamping means 26 is longer than a certain value, the thread end TA clamped by the clamping means 26 is the pulling path of the upper thread loop TL after the second stitch. For example, when it is positioned so as to be hooked on the passage path of the sword tip 15 of the inner hook 16, it is pulled up by the upper thread loop TL (FIG. 19), and is sewn into the seam S on the back of the fabric and passes through the thread catcher 33. A loop W is formed (FIG. 20). By this loop W, the first clamping portion 24, and thus the opening / closing plate 35, rotates around the opening / closing plate support member 37 so that the yarn catching portion 33 is opened. The clamping means 26 can remove the loop W, and consequently the upper thread T, from the thread catching portion 33.

  Here, the “thread end length” of a certain value or more is a case where the distance is longer than the distance from the pinching point of the upper thread T to the needle drop point DP of the fabric C, as described above.

  More specifically, in the thread clamp device 10 of the present embodiment, thread clamping is performed by the opening / closing plate 35 (first clamping part 24) and the second clamping part 25 (clamping surface 25a) at the clamping position, and this clamping position. Is maintained, and the stitched yarn end TA is pulled up by pulling up the upper thread loop TL after the second stitch, and is sewn into the seam S on the back of the fabric and passes through the thread catching section 33. Is formed. When the loop W is strongly sewn into the seam S on the back of the fabric, the clamping means 26 moves to the release position, releasing the upper thread T held between the first clamping part 24 and the second clamping part 25. However, the fabric W and the yarn catching portion 33 remain connected by the loop W without being disengaged from the yarn catching portion 33, specifically, the closing portion 35a of the opening / closing plate 35 constituting the first clamping portion 24. (FIG. 21).

  When the sewing further proceeds in this state, the fabric C moves in the feeding direction, so that the force (tension) for pulling the first clamping portion 24 of the clamping means 26 by the connected loop W gradually increases as the fabric C is fed, The force that pulls the first clamping portion 24, that is, the closing portion 35 a of the opening / closing plate 35 in the Y-axis direction + side biases the closing portion 35 a of the opening / closing plate 35 by the torsion coil spring 38 toward the Y-axis direction − side. When the catching portion 33 is held in the closed state and exceeds the force, the opening / closing plate 35 rotates about the opening / closing plate support member 37 so that the yarn catching portion 33 is opened, and the notch 34 of the closing portion 35a is rotated. The yarn catching portion 33 is in an open state (FIGS. 22 and 23). In FIGS. 19 to 22, only the main parts are denoted by reference numerals.

  The rotation of the opening / closing plate 35 increases as the dough C is fed, so that the portion of the loop W that is in contact with the closing portion 35a contacts the closing portion 35a along the longitudinal direction toward the tip side. If it moves while passing through the rounding portion 41 at the tip of the closing portion 35a, the loop W will be disengaged from the yarn catching portion 33 and thus the clamping means 26 (FIGS. 24 and 25). When the loop W is disengaged from the yarn catching portion 33, the opening / closing plate 35 returns to close the yarn catching portion 33 by the biasing force of the torsion coil spring 38. In FIGS. 19 to 25, only the main parts are denoted by reference numerals.

  Here, when the upper thread T to be used for sewing is thick, such as when the force for pulling the clamping means 26 is high, the spring hanging body 40 on which the other end of the torsion coil spring 38 is hung is replaced and the torsion coil spring 38 is replaced. The spring force of the torsion coil spring 38 is not increased when the upper thread T or the fabric is weak in order to prevent thread breakage or fabric shift.

  Since the rounded portion 41 is formed at the tip of the blocking portion 35a, it is possible to prevent the loop W from being cut accidentally when it exceeds the tip.

  Thus, according to the upper thread gripping device 10 of the present embodiment, the first clamping part 24 is formed so as to be movable so that the thread catching part 33 is opened by the upper thread T after the upper thread T is clamped. Therefore, the tip end side of the thread end TA of the upper thread T clamped between the first clamping part 24 and the second clamping part 25 is sewn into the seam S on the back of the fabric and passes through the thread catching part 33. Even in the case where the loop W is formed, the loop W caused by the feeding of the fabric C as the sewing proceeds advances the yarn catching portion 33 easily and reliably by the force that pulls the first clamping portion 24 in the Y axis direction + side. be able to. Then, by opening the yarn catching portion 33, the loop W and eventually the upper yarn T can be easily and reliably removed from the yarn catching portion.

  Therefore, according to the upper thread clamp device 10 of the present embodiment, the thread catcher 33 sews through the needle hole 8a of the needle plate 8 with the opening of the notch 34 closed at the initial position and the opening / closing plate 35 is closed. The thread end TA of the upper thread T can be captured through the threading hole Na of the needle N, and the clamping means 26 is located between the first clamping part 24 and the second clamping part 25 at the clamping position. The yarn end TA of the yarn T can be clamped and the yarn end TA of the upper yarn T clamped between the first clamping unit 24 and the second clamping unit 25 at the release position can be released.

  Further, according to the upper thread gripping device 10 of the present embodiment, the opening / closing plate 35 serving as an opening / closing body opens the opening of the notch 34 by the upper thread T after the first clamping portion 24 clamps the upper thread T. Since the catching portion 33 is movably formed so as to be in a closed state, the leading end side of the yarn end portion TA of the upper thread T held between the first holding portion 24 and the second holding portion 25 is the seam S. Even when the loop W passing through the thread catching portion 33 is formed, the opening / closing plate 35 as the opening / closing body is cut by the force of pulling the first clamping portion by the loop W due to the feeding of the fabric C as the sewing progresses. Since the thread catching portion 33 can be opened by operating to open the opening of the notch 34, the loop W and eventually the upper thread T can be easily and reliably removed from the yarn catching portion 33. As a result, it is possible to easily and reliably prevent occurrence of fabric shift, thread breakage, device malfunction, and the like, and ensure high sewing product quality.

  Further, according to the upper thread clamp device 10 of the present embodiment, the opening / closing plate 35 as the opening / closing body always keeps the yarn catcher 33 closed by the biasing force of the torsion coil spring 38 as the biasing means. Therefore, the yarn catching portion 33 can be easily closed, and when the force against the biasing force of the torsion coil spring 38 is applied to the first clamping portion 24, the yarn catching portion is It can be in an open state.

  Furthermore, according to the upper thread clamp device 10 of the present embodiment, the biasing force adjusting means 42 for adjusting the biasing force of the torsion coil spring 38 as the biasing means is provided. The power can be easily adjusted.

  Further, according to the upper thread clamp device 10 of the present embodiment, since the thread clamp device 10 can be used even under sewing conditions in which the “insertion length” changes, the quality of the sewing product is improved and the sewing start is started. It has the secondary effect that high speed (productivity) can be maintained and realized.

  Further, according to the upper thread clamp device 10 of the present embodiment, it is not necessary to adjust the “insertion length” in accordance with the thread clamp device 10, and therefore it is not necessary to adjust the “insertion length” when changing the sewing conditions. There is also a secondary effect that productivity is improved.

  Further, according to the upper thread clamp device 10 of the present embodiment, since the thread clamp device 10 can be used regardless of the “insertion length”, the adjustment of the thread take-up spring that affects the “insertion length” and the thread path component There is also a secondary effect that productivity is improved because it is not necessary to replace (gauge).

  Further, according to the upper thread clamp device 10 of the present embodiment, the loop W exceeds the urging force of the torsion coil spring 38 and the opening plate 35, that is, the loop exceeds the urging force of the torsion coil spring 38. Since the loop W is pulled out with the thread catching portion 33 open and the thread catching portion 33 being normally closed, the thread catching portion 33 is normally kept in the closed state. Since the yarn end TA of the yarn T gradually comes out of the yarn catching portion 33, there is also an effect that the nest can be reduced.

  Further, according to the upper thread clamp device 10 of the present embodiment, the driving means 27 moves the upper thread clamping means 26 to the initial position, the clamping position, and the release position by the driving force of one thread gripping motor 58. It can be driven easily and reliably so that it can be taken selectively.

  FIGS. 26 to 31 show another embodiment of the upper thread clamp device of the sewing machine according to the present invention.

  The upper thread clamp device 10A of the present embodiment is configured so that when the first clamping part 24 and the second clamping part 25 are located at the release position, the first clamping part 24 is mechanically opened so that the thread catching part 33 is opened. Forcibly operating means 91 is provided to operate automatically.

  That is, as shown in FIGS. 26 to 28, the upper thread clamp device 10 </ b> A of the present embodiment has an opening / closing plate driving member 92 as the forcible operation means 91. The opening / closing plate driving member 92 is formed in a rod shape that protrudes in the Y-axis direction + side near the X-axis direction − side from the central portion of the tip surface located on the Y-axis direction + side of the guide plate 63A. Further, the front end of the opening / closing plate driving member 92 is a portion between the rotation center and the first sandwiching portion 24 facing the second sandwiching portion 25 in the side surface of the opening / closing plate 35 located on the Y axis direction negative side. It is arrange | positioned in the position facing. Of course, the opening / closing plate driving member 92 is disposed at a position where it does not interfere with the opening / closing plate support member 37.

  Note that the opening / closing plate driving member 92 is not limited to the guide plate 60 </ b> A, and may be disposed at other fixed portions such as the bed portion 2.

  Further, the opening / closing plate driving member 92 rotates the first clamping unit 24 so as to open the yarn catching unit 33 when the first clamping unit 24 and the second clamping unit 25 are positioned at the release position. The angle (opening angle) is preferably an angle at which the loop W can be easily pulled out from the first clamping unit 24.

  Therefore, the opening / closing plate driving member 92 may be configured such that the position of the tip on the + side in the Y-axis direction can be adjusted along the Y-axis direction. For example, there is a configuration in which a screw portion is formed at the base end portion of the opening / closing plate driving member 92 and the screwing amount is changed when the screw portion is screwed into a screw hole provided in the guide plate 60A or another fixing portion. be able to. By adopting such a configuration, the accuracy of parts can be reduced and the cost can be reduced, and the rotation timing and opening angle of the opening / closing plate 35 can be adjusted in detail, and fine settings can be made for the thickness and strength of the upper thread T. If possible, thread breakage can be prevented, and further improvement in sewing quality can be achieved.

  As described above, the first clamping unit 24 is formed to be movable so that the yarn catching unit 33 is opened by the upper yarn T after the upper yarn T is clamped. However, the rotation of the opening / closing plate 35 is gradually increased (opened) by the loop W by the progress of the feeding of the fabric C as the sewing progresses, if the first clamping portion 24 (the closing portion 35a of the opening / closing plate 35) is caught. And the loop W is disengaged from the first clamping unit 24.

  Further, by allowing the first clamping unit 24 and the second clamping unit 25 to move further from the release position to the Y axis direction minus side, the rotation angle (opening angle) of the first clamping unit 24 is adjusted. Also good.

  About another structure, it is the same as that of the upper thread clamp device 10 of embodiment mentioned above, The detailed description is abbreviate | omitted.

  According to the upper thread clamp device 10A of the present embodiment having such a configuration, as shown in FIG. 29, the side surface of the opening / closing plate 35 is driven to open / close the plate while the holding means 26 moves from the holding position to the release position. It contacts the tip of the member 92. Then, when the clamping means 26 reaches the release position, as shown in FIG. 30, the opening / closing plate 35 opens to the angle set in advance with the opening / closing plate support member 37 as the rotation center so that the yarn catching portion 33 is opened. Rotation causes the blocking portion 35a to move away from the opening end located on the distal end side of the notch 34.

  Therefore, according to the upper thread clamp device 10A of the present embodiment, when the first clamping part 24 and the second clamping part 25 are located at the release position, the forced catching means 91 opens the thread catching part 33. Thus, the first clamping unit 24 can be mechanically operated. As a result, a loop in which the tip end side of the thread end TA of the upper thread T clamped between the first clamping part 24 and the second clamping part 25 is sewn into the seam S on the back of the fabric and passes through the thread catching part 33. Even when W is formed, the loop W moves toward the front end side of the closing portion 35a of the opening / closing plate 35 of the yarn catching portion 33 that is opened by the feeding of the fabric C as the sewing progresses, and the closing is performed. After passing through the rounded portion 41 at the tip of the portion 35a, as shown in FIG.

  In other words, according to the upper thread clamp device 10A of the present embodiment, the thread catcher 33 is forcibly closed when the clamping means 26 is located at the release position which is a predetermined timing set in advance by the forcible operating means 91. Since the state can be changed to the open state, the loop W can be removed from the clamping means 26 without applying tension to a low-strength thread or sewing product.

  Therefore, according to the upper thread clamp device 10A of the present embodiment, the same effect as that of the above-described upper thread clamp device 10 can be obtained, and the tip of the thread end portion TA of the upper thread T being clamped can be obtained. Even when the loop W passing through the thread catching portion 33 is formed by sewing the seam S on the back side of the fabric, the loop from the yarn catching portion 33 is not applied to each of the upper thread T, the seam S, and the fabric C. W can be removed easily and more reliably.

  Therefore, according to the upper thread clamp device 10A of the present embodiment, it is possible to more easily and more reliably prevent the occurrence of fabric slippage, thread breakage, device malfunction, and the like, and ensure higher sewing product quality. Can be secured.

  The configuration of the sewing machine thread gripping device that can open and close the thread catching portion by the opening / closing plate of the present invention is used for a sewing machine thread gripping device having an upper thread clamping means having an existing frame-shaped thread holding portion. Can do.

  Further, the present invention is not limited to the above-described embodiments, and various modifications can be made as necessary.

1 is a partially cut external front view showing a main part of a sewing machine provided with an embodiment of an upper thread clamp device of a sewing machine according to the present invention. The perspective view which shows the structure of the principal part of the upper thread clamp apparatus of FIG. 2 is an exploded perspective view of FIG. The expansion exploded perspective view of the 1st clamping part of FIG. Top view of the upper thread guide plate of the hook mechanism of FIG. Front view of the inner hook of the hook mechanism of FIG. The fragmentary perspective view which shows the principal part of a structure of the needle lower part of the sewing machine of FIG. The front view of the principal part in the state in which the upper thread clamping means of the upper thread clamp device in FIG. 1 is located at the initial position FIG. 8 is a partially enlarged view of the main part of the upper thread clamping means. The bottom view of the principal part of the upper thread clamp device of FIG. Partial enlarged view of the main part of FIG. The side view of the principal part in the state where the upper thread clamping means of the upper thread clamp device of FIG. 1 is located at the clamping position The bottom view of the principal part in the state where the upper thread clamping means of the upper thread gripping device of FIG. 1 is located at the clamping position The side view of the principal part in the state where the upper thread clamping means of the upper thread gripping device of FIG. 1 is located at the release position The bottom view of the principal part in the state where the upper thread clamping means of the upper thread gripping device of FIG. 1 is located at the release position Explanatory drawing which shows the relationship between the rocking | fluctuation operation | movement of the relative position adjustment link body of the upper thread clamp device of FIG. 1, and the relative position change of a 1st clamping member and a 2nd clamping member from a downward direction. 1 is a block diagram showing the main part of the control system of the sewing machine of FIG. Flowchart of the operation of the sewing machine of FIG. Explanatory drawing which shows the state in the middle of the upper thread clamp means of the upper thread clamp device of FIG. 1 being located in the clamping position and the thread end of the upper thread being pulled up by the second thread upper thread loop Explanatory drawing which shows the state in which the thread | yarn edge part of the upper thread following FIG. 19 was sewed into the seam of the fabric back, and the loop which passes a thread | yarn capture part was formed. 20 is an explanatory view showing a state in which the fabric and the yarn catching portion are connected by the loop without the loop being detached from the yarn catching portion after the upper yarn clamping means subsequent to FIG. 20 is located at the release position and the yarn end portion of the upper yarn is released. Explanatory drawing which shows the state which the loop act | operated the 1st clamping part so that a thread | yarn capture | acquisition part might be in an open state by the feeding of the cloth | yarn accompanying progress of sewing following FIG. Explanatory drawing which shows the operation state of the 1st clamping part of the upper thread clamp apparatus of FIG. 22 seeing from a downward direction Explanatory drawing which shows the state from which the loop removed from the thread | yarn capture | acquisition part by feeding of the cloth | yarn accompanying the progress of sewing following FIG. Explanatory drawing which shows the state which the loop of FIG. 24 removed from the thread | yarn capture | acquisition part seeing from the downward direction The front view which shows the principal part of the state which the upper thread clamping means of the sewing machine provided with other embodiment of the upper thread clamp device of the sewing machine concerning this invention located in the initial position The bottom view of the principal part of the upper thread clamp device of FIG. The top view of the guide plate of FIG. Explanatory drawing which shows the state which the forced operation means of the upper thread clamp device of FIG. 26 operated the 1st clamping part. Explanatory drawing which shows the operation state of the 1st clamping part of the upper thread clamp apparatus of FIG. 29 seeing from the downward direction Explanatory drawing which shows the state which the loop of FIG. 29 removed from the thread | yarn capture | acquisition part seeing from the downward direction Explanatory drawing which shows the state which clamped the upper thread in the conventional upper thread clamp device of a sewing machine Explanatory drawing which shows the state which a thread | yarn end part enters in the inside of the upper thread | yarn loop in the upper thread clamp device of the conventional sewing machine. Explanatory drawing which shows the state by which the thread end part of an upper thread is pulled up with the upper thread loop following FIG. Explanatory drawing which shows the state in which the thread | yarn end part of the upper thread following FIG. 34 was sewn into the seam of the fabric back, and the loop which passes a thread | yarn capture part was formed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sewing machine 8 Needle plate 8a Needle hole 9 Hook mechanism 10, 10A Upper thread clamp device 11 Control means 24 1st clamping part 25 2nd clamping part 26 Upper thread clamping means 27 Driving means 28 Moving means 29 Related operation means 31 1st clamping Member 32 Second clamping member 33 Yarn catching portion 34 Notch 35 Opening and closing plate 35a Closure portion 38 Torsion coil spring (biasing means)
40 Spring hanging body 42 Energizing force adjusting means 55 Y-axis moving mechanism 56 Moving position detecting means 63 63a Guide plate 91 Forced operation means 92 Opening / closing plate driving member N Sewing needle Na Threading hole NL Vertical movement path T Upper thread TA Thread end TL Upper thread loop W Loop C Fabric

Claims (4)

It has an upper thread clamping means for catching and clamping the thread end of the upper thread, and a driving means for driving the upper thread clamping means, and is inserted into the threading hole of the sewing needle at the start of sewing. After capturing and pinching the thread end portion of the upper thread that is below the needle plate of the bed portion and at a position separated from the vertical movement path of the sewing needle, and then dropping the preset number of needles, In the upper thread clamp device of the sewing machine that is formed so as to release the thread end of the upper thread that has been sandwiched,
The upper thread clamping means includes
A thread catching portion including a notch and an opening / closing body arranged to be able to open and close the opening of the notch, and a first clamping portion is formed by a portion of the opening / closing body that closes the opening of the notch. A first clamping member;
A second clamping member provided with a second clamping part that is arranged so as to be able to contact and separate relative to the first clamping part and clamps the yarn end part with the first clamping part; ,
The thread catching portion is formed so as to form a frame shape as a whole through which a threading hole of a sewing needle passing through a needle hole of the needle plate can pass with the opening of the notch closed with the opening / closing body closed. And
The first clamping portion and the second clamping portion are formed so that the opening and closing body clamps the yarn end portion in the closed state of the yarn catching portion in which the opening of the notch is closed,
The driving means includes at least an initial position where the inside of the yarn catching portion is located on the vertical movement path and the first clamping portion and the second clamping portion are opposed to both sides via the vertical movement path; A clamping position in which the first clamping part and the second clamping part are spaced apart from each other in the vertical movement path and the yarn end part is clamped between the first clamping part and the second clamping part; The upper thread clamping means is configured to be drivable so that two positions can be taken selectively,
Furthermore, the first catching portion has the yarn catching portion in which, after the upper thread is pinched, the tension of the upper thread acts strongly on the opening / closing body, and the opening / closing body opens the opening of the notch by the upper thread. An upper thread clamp device for a sewing machine, which is formed so as to be movable so as to be closed. It has an upper thread clamping means for catching and clamping the thread end of the upper thread, and a driving means for driving the upper thread clamping means, and is inserted into the threading hole of the sewing needle at the start of sewing. After capturing and pinching the thread end portion of the upper thread that is below the needle plate of the bed portion and at a position separated from the vertical movement path of the sewing needle, and then dropping the preset number of needles, In the upper thread clamp device of the sewing machine that is formed so as to release the thread end of the upper thread that has been sandwiched,
The upper thread clamping means includes
A thread catching portion including a notch and an opening / closing body arranged to be able to open and close the opening of the notch, and a first clamping portion is formed by a portion of the opening / closing body that closes the opening of the notch. A first clamping member;
A second clamping member provided with a second clamping part that is arranged so as to be able to contact and separate relative to the first clamping part and clamps the yarn end part with the first clamping part; ,
The thread catching portion is formed so as to form a frame shape as a whole through which a threading hole of a sewing needle passing through a needle hole of the needle plate can pass with the opening of the notch closed with the opening / closing body closed. And
The first clamping portion and the second clamping portion are formed so that the opening and closing body clamps the yarn end portion in the closed state of the yarn catching portion in which the opening of the notch is closed,
The driving means includes at least an initial position where the inside of the yarn catching portion is located on the vertical movement path and the first clamping portion and the second clamping portion are opposed to both sides via the vertical movement path; A clamping position in which the first clamping part and the second clamping part are spaced apart from each other in the vertical movement path and the yarn end part is clamped between the first clamping part and the second clamping part; The yarn end portion in which the first clamping portion and the second clamping portion are further separated from the clamping position to the side of the vertical movement path and are clamped between the first clamping portion and the second clamping portion. The upper thread clamping means is configured to be drivable so that three positions with a release position to be released can be selectively taken,
Further, after the upper thread is clamped, when the upper thread is released, the first clamping unit strongly applies tension of the upper thread to the opening / closing body, and the upper thread opens the opening of the notch by the upper thread. An upper thread clamp device for a sewing machine which is formed so as to be movable so that the thread catching portion is closed.   The upper thread clamp of the sewing machine according to claim 1 or 2, wherein the opening / closing body is formed so as to hold the yarn catching portion in a closed state by a biasing force of a biasing means at all times. apparatus.   4. The upper thread clamp device of the sewing machine according to claim 3, further comprising an urging force adjusting means for adjusting an urging force of the urging means.

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