JP4030864B2 - Upper thread holding device for sewing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an upper thread holding device of a sewing machine, and more particularly to an upper thread holding device of a sewing machine that holds an end portion of an upper thread up to a predetermined number of stitches at the start of sewing.
[0002]
[Prior art]
In the sewing operation of the sewing machine, the upper thread is inserted into the threading hole of the sewing needle and the first stitch is started with the tip of the needle free, so the length of the upper thread remaining on the back side of the cloth at the start of sewing Upper thread holding device that holds the end of the upper thread on the back side of the needle plate from the first stitch at the start of sewing to the needle drop of a predetermined number of stitches in order to reliably form the seam at the beginning of sewing while shortening the length Are being used (see, for example, Patent Document 1 and Patent Document 2).
[0003]
In Patent Document 1, a thread clamp provided with a through hole is provided with a capturing position for capturing an end of a sewing needle, a retaining position for retaining the captured upper thread end, and an retained upper thread end. An upper thread holding device (described as “thread grasping device” in the literature) that is moved to a release position to be opened is disclosed. Such an upper thread holding device positions the thread clamp through hole in the vertical movement path of the sewing needle at the capture position, and retracts it to the holding position along the hook shaft direction after the first sewing needle is raised. At the holding position, the upper end portion captured by the through hole is clamped between the clamping surface provided on the needle plate and the upper surface of the thread clamp. Furthermore, when the predetermined number of stitches have been sewn, the thread clamp is rotated in a direction away from the needle plate, and released by releasing the pinching state of the upper thread end between the needle plate and the thread clamp. ing.
[0004]
Patent Document 2 includes a thread gripping plate and a thread gripping wire supported so as to be movable along the outer edge thereof. The thread gripping wire is fed forward from the tip of the thread gripping plate to form a loop. An upper thread holding device is disclosed in which the upper thread end inserted through the loop is clamped between the distal end of the thread gripping plate and the thread gripping wire by pulling the gripping wire (in the literature, “the sewing machine bird Nest prevention device ”). In such an upper thread holding device, the thread gripping wire and the thread gripping plate are positioned so that the loop is positioned on the vertical movement path of the sewing needle in a state where the loop is formed, and the thread gripping wire is moved after the first stitching needle is raised. To hold the upper thread end. The holding force at this time is set to be weaker than the lifting force of the balance, the holding length of the upper thread end is shortened by the pulling force of the balance, and further, sewing of several needles is repeated to feed the fabric. Thus, the upper thread is pulled out naturally between the thread gripping wire and the thread gripping plate. Thereafter, the thread gripping wire and the thread gripping plate are retracted to the retracted position.
[0005]
[Patent Document 1]
Japanese Patent No. 2671478
[Patent Document 2]
JP 2000-325683 A
[0006]
[Problems to be solved by the invention]
However, in each of the above-described conventional upper thread holding devices described in Patent Documents 1 and 2, the direction in which the member that clamps the upper thread moves is closer to the tip of the sewing machine bed than the vertical movement path of the needle. The member that holds the needle is also arranged on the tip side of the sewing bed with respect to the vertical movement path of the needle, and a space for storing the upper thread holding device is required on the tip side of the sewing bed. Such an upper thread holding device cannot be used in a cylinder bed sewing machine in which the front end side of the sewing machine bed is required to be thin and long.
[0007]
The present invention provides an upper thread holding device for a sewing machine that can be applied to a cylinder bed sewing machine while improving the inconvenience of the conventional example and maintaining the length of the end side after holding the upper thread short. For that purpose.
[0008]
[Means for Solving the Problems]
In the invention according to claim 1, the end portion of the upper thread inserted through the sewing needle at the beginning of sewing is below the needle plate, and Of the inner hook driven by the hook shaft The needle thread is clamped above the passing path of the sword tip with respect to the sewing needle, and the end of the clamped upper thread is moved to a position away from the vertical movement path of the sewing needle. In the upper thread holding device of the sewing machine that opens the part, the upper part between the holding part that holds the end part of the upper thread and the holding part that moves relative to the holding position and the holding position relative to the holding part. A first moving position that is positioned on the vertical movement path of the sewing needle, and a vertical body side of the sewing machine from the first movement position to the vertical movement path of the sewing needle. A second moving position separated from the second moving position and a third moving position further separated from the vertical movement path of the sewing needle toward the standing body side of the sewing machine from the second moving position, and at the beginning of sewing the holding means After moving from the first movement position to the second movement position and stopping for a predetermined number of stitches, When the moving means for moving from the moving position to the third moving position and the holding means are located at the first moving position, the holding part is disposed at a position closer to the vertical body part of the sewing machine than the vertical movement path of the sewing needle, The holding part is arranged at a position facing the holding part across the vertical movement path of the sewing needle, and when the holding means moves from the first movement position to the second movement position, both the holding part and the holding part are brought close to each other. The end of the upper thread is clamped and the clamping means is moved to the second movement position, and the clamping means moves from the second movement position to the third movement position or at the third movement position. And a related operation means for mechanically interlocking the holding portion and the holding portion with the movement of the moving means so as to open the end portion of the upper thread that is held by separating the holding portion and the holding portion. Adopted.
[0009]
In the above configuration, the clamping means is positioned at the first movement position, and the holding portion is disposed on one side of the sewing body standing body portion across the vertical movement path of the sewing needle, and the clamping portion is disposed on the other side. In this state, the upper thread end portion is inserted between the holding portion and the clamping portion by the lowering and raising of the first stitch of the sewing needle.
In this state, the clamping means is moved from the first movement position to the second movement position that is separated toward the sewing machine upright body side. In this movement, the holding portion moves toward the holding portion, and the holding portion moves toward the holding portion. Therefore, the holding position where the holding portion abuts is greater than the position of the holding portion in the first movement position. Approach the vertical movement path.
Then, the holding means waits at that position after reaching the second movement position, and when a predetermined number of needle drops are performed, the clamping means moves toward the third movement position that is further away from the sewing machine upright body. At this time, since the holding portion and the clamping portion are separated by the related operation means, the upper thread end portion is released.
[0010]
In this configuration, the clamping means moves from the position where the sewing needle moves up and down toward the standing body portion of the sewing machine. The fact that the clamping means moves toward the vertical body side of the sewing machine means that it is not necessary to secure a space for moving the clamping means closer to the tip side than the vertical movement path of the sewing needle of the sewing machine bed. Such a configuration can be applied to a cylinder bed.
Further, when the clamping means is moved from the first movement position to the second movement position on the sewing machine stand trunk side, and the upper thread is clamped during this movement, only the holding part is used as the sewing machine stand drum part. When the upper thread is clamped by moving toward the gripping part located on the side, in order to shorten the length of the upper thread end part remaining on the cloth back, the clamping part is positioned close to the vertical movement path of the sewing needle. In this case, it is necessary to expand the upper thread loop scooped by the hook of the hook and prevent the upper thread from being extended by the upper thread guide plate that prevents the hook from contacting the race surface of the hook. This causes a problem that the upper thread touches the hook shaft side race surface of the inner hook and gets dirty, or is pulled into the hook shaft side race surface of the inner hook. On the other hand, in order to avoid the occurrence of such a problem, if the position of the clamping portion is arranged at a position away from the vertical movement path of the needle, this time, the clamping position of the upper thread end is separated from the vertical movement path of the needle. This causes a problem that the remaining thread length remaining on the cloth back cannot be shortened.
However, in the invention described in claim 1, when the upper thread end is clamped, the clamping part also moves toward the holding part. Therefore, when the sword tip of the inner hook scoops the upper thread loop, the clamping part is moved to the needle. The needle is moved a predetermined distance away from the vertical movement path of the sewing needle, and then the needle is removed from between the clamping part and the holding part, and then the clamping part is moved to a clamping position close to the vertical movement path of the sewing needle to move the upper thread. Can be pinched. Therefore, the remaining thread length remaining on the cloth back can be shortened without preventing the upper thread guide plate from expanding the upper thread.
[0011]
The invention according to claim 2 has the same configuration as that of the invention according to claim 1, and the related operation means is arranged such that the arrangement of the tip end portion of the clamping part when the clamping means is located at the first movement position The hook means is moved from the first movement position to the second movement position with respect to the hook shaft side from the straight line connecting the hook shaft side edge of the needle hole provided in the hook and the upper edge of the hook shaft side race surface of the intermediate hook. The position where the end portion of the upper thread is clamped by the holding portion and the clamping portion is used in the vicinity of the vertical movement path of the sewing needle.
[0012]
In the above configuration, the same effect as that of the first aspect of the invention can be obtained, and when the clamping means is in the first movement position, the clamping portion has a tip end portion at the hook shaft side edge of the needle hole and the hook of the inner hook. It is located on the shuttle shaft side of the straight line connecting the upper end edge of the shaft side race surface, and is arranged so as not to enter the vertical movement path side of the sewing needle from the straight line. The straight line connecting the hook shaft side edge of the needle hole and the upper end edge of the hook shaft side race surface of the inner hook indicates the boundary of the range through which the upper thread passes, and the clamping part is located on the hook shaft side from the straight line. Therefore, it is possible to reliably prevent the upper thread loop from being hindered from being expanded by the upper thread guide plate, and to more effectively avoid contact between the hook shaft side race surface of the intermediate hook and the upper thread.
[0013]
The invention described in claim 3 has the same configuration as that of the invention described in claim 1 or 2, and the holding means includes a holding member provided with a holding part and a holding member provided with a holding part, and related operation means. Is a guide means for supporting the holding member and the holding member so as to reciprocate in the direction along the shuttle shaft, and a constant tension is applied between the holding member and the holding member in a direction in which the holding portion and the holding portion approach each other. The tension biasing means to be applied and the clamping means and the holding member are connected to and separated from each other so that the clamping part and the holding part can be brought into contact with and separated from each other according to a change in posture due to their own swinging. The relative position adjusting link body to which the moving force to each moving position is input, and the direction in which the holding portion is separated from the holding position when the holding means is at the first moving position. The first contact part that swings And a second abutting member that abuts on the relative position adjusting link body and swings the clamping part and the holding part in a direction to separate them when the clamping means is in the third movement position. The position adjustment link body includes a rotation engagement portion between the rotation engagement portion with the holding member, the rotation engagement portion with the holding member, and the moving means positioned therebetween, along the longitudinal direction thereof. The first abutting member is configured to abut at a position between the rotational engagement portion with the clamping member and the rotational engagement portion with the moving means.
[0014]
In the above configuration, the same effect as that of the first or second aspect of the invention can be obtained, and when the clamping means is disposed at the first movement position, the relative position adjustment link body is moved to the contact position by the first contact member. Is used as a fulcrum to separate the holding part and the clamping part against the tension urging means.
And when moving to a 2nd movement position, the contact state of the 1st contact member with respect to a relative position adjustment link body is cancelled | released with a movement. Therefore, the relative position adjusting link body swings in a direction to be returned by the tension urging means with the contact point with the first contact member as a fulcrum. Since the relative position adjustment link body swings between the rotation engagement portion with the holding member and the rotation engagement portion with the holding member in this way, the holding portion and the holding portion are in directions of approaching each other. Moved to. For this reason, the upper thread end is held when the clamping means moves to the second movement position.
Further, when moving from the second movement position to the third movement position, the second abutting member swings the relative position adjustment link body as the third movement position is approached, The upper part of the upper thread ends which are held apart from the holding part are opened.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
(Overall schematic configuration of sewing machine)
A sewing machine 100 to which an upper thread holding device 10 according to an embodiment of the present invention is applied will be described with reference to FIGS. FIG. 1 is an overall view showing an outline of the sewing machine 100. The outline of the sewing machine 100 is roughly outlined from the top of the sewing machine bed 101, the sewing machine bed 101 that is raised upward from one end of the sewing machine bed 101, and the sewing machine stand 102. A sewing machine arm 103 is provided so as to extend along the sewing machine bed 101. The sewing machine 100 corresponds to a so-called cylinder bed sewing machine in which the front end portion of the sewing machine bed 101 is formed in a substantially cylindrical shape and the width in the X-axis direction described later is set narrower than other parts.
In describing the configuration of the sewing machine 100, the vertical movement direction of the sewing needle 104, which will be described later, is the Z-axis direction, and the longitudinal direction of the sewing bed 101 and the sewing machine arm 103 is the Y-axis direction. A direction orthogonal to both the Z-axis direction and the Y-axis direction is taken as an X-axis direction. When the sewing machine 100 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 right, the − side is left, the + side in the Y-axis direction is front, − Express the side as the back.
[0016]
The sewing machine 100 is provided at the tip of the sewing machine arm 103 and is driven by a sewing machine motor 105 to reciprocate in the vertical direction. The sewing machine 104 is provided at the upper part of the sewing machine arm 103 and supplies an upper thread to the sewing needle 104. An upper thread supply source that is not used, a thread tension device 106 that clamps the upper thread with a predetermined load between the upper thread supply source and the sewing needle 104, and generates resistance in movement in the feed direction, and this thread tension A balance device that pulls the upper thread with a balance 107 at a predetermined timing between the device 106 and the sewing needle 104, and a needle hole 108a that is provided on the upper surface of the sewing machine bed 101 and through which the tip of the sewing needle 104 is inserted. The needle plate 108, which is provided in the sewing machine bed 101 and below the needle plate 108, scoops the upper thread loop from the lowered sewing needle 104 and lowers it to the loop. A hook mechanism 120 for inserting the needle thread, a needle thread holding device 10 for holding the upper thread end when the first stitch of the sewing needle 104 is raised between the needle plate 108 and the hook mechanism 120, and the sewing machine bed 101. , A thread trimming device (not shown) for cutting the upper thread and the lower thread after sewing, and an operation control means 80 for controlling the operation of each of the above-described configurations.
[0017]
The sewing needle 104 is formed with a threading hole somewhat above its tip (lower end), and the upper thread is inserted into this threading hole. The sewing needle 104 is supported at the lower end of the needle bar 104a. The needle bar 104a is applied by converting a rotational driving force from the sewing machine motor 105 into a vertical reciprocating driving force by a crank mechanism (not shown). Reciprocates up and down in a cycle. The sewing machine motor 105 is provided with an encoder 109 for detecting the amount of rotation angle. When the sewing needle 104 is at the top dead center position, the current output shaft of the sewing machine motor 105 is 0 to 360 degrees. Which angle position is present is output to the operation control means 80.
[0018]
The balance 107 is provided with an upper thread insertion hole (not shown), and moves up and down while the upper thread is inserted, thereby pulling up the upper thread inserted into the sewing needle 104 when the upper thread is lifted. The balance device moves the balance 107 up and down at the same cycle as the sewing needle 104, but the timing of the balance 107 adjacent to the top dead center is set to be somewhat delayed from the top dead center of the sewing needle.
[0019]
As shown in FIG. 6, the shuttle mechanism 120 performs reciprocating half rotation, and the inner hook 122 that captures the loop of the upper thread by the sword tip 121 protruding along the circumferential direction of rotation, and the inner hook 122 is rotatably supported. A cauldron 123, an upper thread guide plate 124 provided on the upper portion of the cauldron 123, and extending in parallel to the longitudinal direction of the sewing machine bed from the sewing machine stand trunk side to the cauldron 123, and reciprocating back and forth to the intermediate hook 122 via a screwdriver (not shown) And a hook shaft 125 for applying a half-rotation driving force.
[0020]
The inner hook 122 is formed with a rail-like projecting structure 126 across its outer periphery so that half rotation can be repeated, and provided with race surfaces 127 and 128 in sliding contact with the support groove 123a of the hook 123 on both sides thereof. Further, the sword tip 121 is formed at the end of the rail-shaped protruding structure 126, and the threading of the sewing needle 104 that has entered from the guide hole of the upper thread guide plate 124 by one half rotation of the inner hook 122. Scoop the upper thread loop by passing directly next to the hole. For this reason, the tip of the sword 122 is formed in a shape in which the tip end thereof is biased in one direction L along the rotation center line of the inner hook 122, and the sword tip 121 and the protruding structure 126 are arranged on the upper and lower sides of the sewing needle 104. It is arranged on the other direction R side along the rotation center line with respect to the moving path N.
[0021]
The hook shaft 125 is positioned on the R side with respect to the inner hook 122 (hereinafter, the direction R side is referred to as the hook shaft side) and is not directly connected to the inner hook 122. In addition, a driving force for half-reciprocal rotation is transmitted to the inner hook 122 through a driver that reciprocates half-rotation.
The shuttle shaft 125 of the shuttle mechanism 120 is disposed in parallel to the Y-axis direction, and is positioned on the negative side of the Y-axis direction with respect to the intermediate shuttle 121 and applies reciprocating half-rotation driving force from this direction. The shuttle shaft 125 is configured such that the driving force branched from the sewing machine motor 105 is converted into reciprocating rotation and transmitted, and the vertical reciprocating operation of the sewing needle 104 and the reciprocating half-rotating operation of the inner shuttle 122 are performed. Synchronization is achieved with a predetermined phase difference.
[0022]
The upper thread guide plate 124 is a plate-like member for preventing the upper thread inner hook 122 from coming into contact with the race surfaces 127 and 128, and is shown in FIG. 4 when viewed from above (in the direction of arrow U). A guide hole 124 a having such a shape is provided, and a thread dividing portion 124 b for spreading the upper thread loop scooped by the sword tip 121 of the inner hook 122 is provided at a substantially central portion on the right side of the guide hole 124 a. As shown in FIGS. 5 and 17, the upper thread loop scooped by the sword tip 121 rotating in the direction of arrow S is thread N on the sewing needle side with the sword tip 121 as a boundary by this thread dividing portion 124b. _F And thread N on the fabric side _B Therefore, the inner hook 122 is prevented from coming into contact with the race surfaces 127 and 128 and from being caught.
[0023]
(Configuration of upper thread holding device)
In order to prevent the upper thread end portion at the start of sewing from being pulled out of the fabric, the upper thread holding device 10 moves the end portion of the upper thread inserted through the sewing needle 104 at the beginning of the sewing to the lower side of the needle plate 108. In addition, the needle is clamped above the passage of the sword tip of the inner hook 121 with respect to the sewing needle 104, and the end portion of the clamped upper thread is moved to a position away from the vertical movement path of the sewing needle 104 so that a predetermined number of stitches are obtained. After the needle drop, the end of the clamped upper thread is opened.
[0024]
The upper thread holding device 10 has a holding part 21 that holds the end part of the upper thread, and moves relative to the holding part 21 between the holding position and the release position, so that the upper thread is held between the holding part 21 and the upper part. A clamping means 20 having a clamping part 31 for clamping and releasing the end part, and a clamping means 20 from the first movement position and the first movement position located on the vertical movement path N (see FIG. 6) of the sewing needle 104 Up and down movement path N of the sewing needle 104 (path parallel to the Z-axis direction and connecting the tip position of the sewing needle 104 at the top dead center to the tip position of the sewing needle 104 at the bottom dead center) It is possible to move to the second movement position separated to the body part 102 side) and to the third movement position separated further to the rear side (sewing stand body part 102 side) than the second movement position, and at the start of sewing. Move from the first movement position to the second movement position, and the needle drop of the specified number of stitches When the moving means 40 for moving from the second movement position to the third movement position after stopping for a while and the holding means 20 are located at the first movement position, the holding portion 31 is moved from the vertical movement path of the sewing needle 104 to the vertical stand of the sewing machine. The holding part 21 is arranged at a position facing the holding part 31 across the vertical movement path N of the sewing needle 104, and the holding means 20 is moved from the first movement position to the second movement position. When this is done, both the holding part 21 and the holding part 31 are moved in a direction approaching each other to hold the end part of the upper thread, and the holding means 20 is moved to the second movement position. When moving from the second movement position to the third movement position, or at the third movement position, the holding part 31 and the holding part 21 are opened so that the end part of the upper thread clamped with the holding part 31 isolated from the holding part 21 is released. The moving means 20 And a relevant operating means 60 for mechanically interlocking. Hereinafter, each part will be described in detail.
[0025]
(Clamping means of upper thread holding device)
2 is a perspective view showing a main overall configuration of the upper thread holding device 10, and FIG. 3 is an exploded perspective view thereof.
As shown in these figures, the clamping means 20 includes a holding member 22 having a holding part 21 and a clamping member 32 having a clamping part 31. Each of these members 22 and 32 has a long plate shape as a whole, and they are overlapped with the sandwiching member 32 as the top, and both have their longitudinal directions oriented parallel to the Y-axis direction. Both are supported by the related operation means 60 so as to be slidable along the Y-axis direction (front-rear direction). Hereinafter, when words indicating directions are used in the description of each part of the clamping means 20, the direction in the state where the clamping means 20 is supported by the related operation means 60 is indicated unless otherwise specified. .
[0026]
The holding member 22 has rectangular through holes 23 and 24 formed in the front and rear ends at the front and rear ends, respectively, and is the inner surface of the front through hole 23 and located at the most front end, and Y A portion including a surface facing the axis + direction is the holding portion 21. The front through-hole 23 also functions as a guide hole for guiding the movement of the clamping part 31 of the clamping member 32 in the front-rear direction.
The through-hole 24 on the rear side of the holding member 22 is provided with a tension spring 62 of the related operation means 60 described later, and forms an operation region for expanding and contracting. One end of the tension spring 62 is connected to the front end of the rear through hole 24.
In addition, a bracket portion 25 extending toward the X-axis direction is provided at a position slightly rearward of the holding member 22 in the Y-axis direction, and a round portion extending downward is provided at the tip portion thereof. A rod-like engagement pin 26 is fixedly equipped. The holding member 22 receives a moving force in the front-rear direction by the related operation means 60 through the engagement pin 26.
[0027]
The clamping member 32 is divided into a front side portion 33 and a rear side portion 34, and these are connected by a connecting body 35 to form an integral substantially long plate shape. A clamping portion 31 is provided at the front end portion of the front side portion 33, and the clamping portion 31 is disposed below the holding portion 21 at the time of contact with the flat surface portion 30 that can contact and separate from the holding portion 21. And a bent portion 36 that protrudes forward from the front end surface of the holding member 22.
Therefore, the upper thread inserted from above into the front through hole 23 of the holding member 22 by the closest approach between the holding member 22 and the holding member 32 is held between the holding portion 21 and the flat portion 30 of the holding portion 31. Is possible. Further, the clamped upper thread is bent forward by a bent portion 36 extending forward from the lower end of the flat surface portion 30 so that the upper thread is not lowered from the front. it can. As a result, the upper thread end portion hangs down in a state of being positioned forward by the bent portion 36, and is therefore shifted forward from the intermediate hook 122 of the hook mechanism 120 positioned below the upper thread end, Contact with 122 and entrainment can be prevented.
[0028]
When the rear side portion 34 is formed with a through hole 37 along the front-rear direction and the sandwiching member 32 and the holding member 22 are overlapped and supported by the related operation means 60, the through hole 37 holds the above-described holding hole. Overlapping with the rear through hole 24 of the member 22, the tension spring 62 of the related operation means 60 is arranged inside these to form an operation region for expanding and contracting. The other end of the tension spring 62 is connected to the rear end of the through hole 37. Accordingly, the holding member 32 is connected to the holding member 22 via the tension spring 62, and the holding portion 21 of the holding member 22 and the holding portion 31 of the holding member 32 are always close to each other and elastic force is applied in the abutting direction. Will be granted.
[0029]
In addition, a bracket portion 38 extending in the X-axis + direction is provided at the intermediate portion in the Y-axis direction of the clamping member 32, and a round bar-like engagement pin extending downward is provided at the tip portion thereof. 39 is fixedly equipped. The pinching member 32 receives a moving force in the front-rear direction by the related operation means 60 via the engagement pin 39.
[0030]
(Moving means of upper thread holding device)
The moving means 40 will be described with reference to FIGS.
The moving means 40 is positioned in advance at the first moving position below the vertical movement path N of the sewing needle before the start of sewing with respect to the holding portion 21 and the holding portion 31 of the holding means 20, and after the start of sewing. When the first sewing needle is pulled out from the fabric, the sewing needle is positioned at the second movement position behind the first movement position with respect to the vertical movement path N of the sewing needle. When performed (for example, the second to third stitches), three-stage positioning is performed in which the sewing needle is positioned at the third movement position behind the second movement position with respect to the vertical movement path N of the sewing needle.
Therefore, the moving means 40 includes a Y-axis moving mechanism 41 that reciprocates the holding means 20 supported by the related operation means 60 along the Y-axis direction, and the holding means 20 is in each of the first to third movement positions. A moving position detecting means 46 for detecting whether or not, and a moving positioning control means for controlling the operation of the Y-axis moving mechanism based on the detection of the moving position detecting means 46.
[0031]
As shown in FIGS. 2 and 3, the Y-axis moving mechanism 41 includes a thread gripping motor 42 that outputs a rotational driving force, and a main link in which its swing center position is connected to the output shaft of the thread gripping motor 42. A body 43, a driven link body 44 that applies a moving force in the Y-axis direction to the relative position adjustment link 63 of the related operation means 60, and a transmission link body 45 that transmits a driving force from the main link body 43 to the driven link body 44. It has.
[0032]
The thread gripping motor 42 is a stepping motor and is driven by an arbitrary rotation angle amount in the positive and negative directions by the operation control of the operation control means 80.
One end of the main link 43 is fixedly connected to the output shaft of the thread gripping motor 42, and the other end is rotatably connected to one end of the transmission link 45.
One end of the driven link body 44 is pivotally supported by a guide plate 61 (to be described later) of the related operation means 60, and the other end is rotatably connected to the other end of the transmission link body 45. Further, the substantially U-shaped follower link body 44 is provided with an engagement protrusion 52 for applying a moving force along the Y-axis direction to the relative position adjustment link 63 of the related operation means 60.
The transmission link body 45 is disposed substantially along the Y-axis direction, and swings the driven link body 44 along with the swing of the main link body 43 driven by the thread gripping motor 42.
With these configurations, when the thread gripping motor 42 is driven, the driven link body 44 swings with the swing of the main link body 43, and the relative position adjustment link 63 of the related operation means 60 is moved in the Y-axis direction via the engagement protrusion 52. Move along.
[0033]
The moving position detecting means 46 will be described with reference to FIGS. 2 and 3, the movement position detecting means 46 is not shown.
The moving position detecting means 46 includes a first and second state sensors 47 and 48 that have a light emitting element and a light receiving element and detect the presence or absence of a shield between them, and the Y-axis moving mechanism 41 described above. The transmission link body 45 includes a shielding plate 51 having first and second shielding regions 49 and 50.
[0034]
The first and second state sensors 47 and 48 are arranged side by side along the movement line of the shielding plate 51 and the first state sensor 47 is arranged on the rear side. Thereby, each state sensor 47 and 48 will be in the state located in a line along the Y-axis direction. The light receiving elements of the state sensors 47 and 48 turn on the state with the shielding object, turn off the state without the shielding object, and output a signal that can identify each state to the operation control means 80.
[0035]
On the other hand, the shielding plate 51 is fixedly supported by the transmission link body 45 so as to pass between the light emitting element and the light receiving element with respect to both the first and second state sensors 47 and 48.
Then, as shown in FIG. 6, the first shielding area 49 is located between the first state sensor 47 and the second state sensor 48 when the clamping means 20 is in the first movement position, and the second movement position. 10 is in a position to shield the first state sensor 47 as shown in FIG. 10, and when in the third movement position, it is still in a position to shield the first state sensor 47 as shown in FIG. The Y-axis direction position and the Y-axis direction length are set.
Further, as shown in FIGS. 6 and 10, the second shielding area 50 is more forward than the first state sensor 47 in any case when the clamping means 20 is in the first movement position or the second movement position. The position in the Y-axis direction is set so as to be a position where the first state sensor 47 is shielded for the first time as shown in FIG.
[0036]
Accordingly, the operation control means 80 can confirm that the clamping means 20 is in the first movement position because both the first and second state sensors 47 and 48 are in the OFF state, and the clamping means 20 is in the second movement. It can be confirmed from the fact that the first state sensor is in the ON state and the second state sensor 48 is in the OFF state, and the first and second state sensors indicate that the clamping means 20 is in the third movement position. It can be confirmed that both 47 and 48 are in the ON state.
[0037]
The movement positioning control means will be described. Such movement positioning control means is actually realized by the control of the operation control means 80. Thus, the movement positioning control means may be realized by borrowing a part of the function of the control means for controlling the operation of the entire sewing machine, or may be realized by an independent control means.
The operation control means 80 as the movement positioning control means is previously provided with a rotational angle amount of the thread gripping motor 42 for moving the clamping means 20 from the first movement position to the second movement position, and from the second movement position to the third movement position. The rotation angle amount to be moved is stored, and when the clamping means 20 is positioned at the second and third movement positions, the operation of the thread gripping motor 42 is controlled with reference to the stored angle position.
For the first movement position, the operation control means 80 performs control as the initial position control section using the movement position detection means 46 when the main power of the sewing machine 100 is turned on, and drives the thread gripping motor 42 to change the first movement position. A position where both the first and second state sensors 47 and 48 are in the OFF state is searched, and standby is performed at that position.
In addition, when the encoder 109 of the sewing machine motor 105 detects that the output shaft angle is 245 [°] at the first stitch after the start of sewing, it recognizes that the sewing needle 104 has been pulled upward from the fabric and holds the clamping means 20. Control as an upper thread holding control unit for positioning at the second movement position is performed. In the sewing machine 100, when the top dead center position of the sewing needle 104 is set to 0 ° with respect to the output shaft of the sewing machine motor 105, the sewing needle 104 passes the bottom dead center when rotated to 245 °, and the needle plate 108 It is set so as to come out upward.
Further, when the needle drop is detected a predetermined number of times after the start of correction by the output of the encoder 109, control as an upper thread release control unit for positioning the clamping means 20 at the third movement position is performed.
[0038]
(Related operation means of upper thread holding device)
The related operation means 60 will be described with reference to FIGS.
The related operation means 60 includes a guide plate 61 as a guide means for reciprocally supporting the holding member 32 and the holding member 22 along the Y-axis direction, and a direction in which the holding section 31 and the holding section 21 approach each other. A tension spring 62 as a tension urging means that constantly applies tension between the clamping member 32 and the holding member 22, and the clamping part 31 and the holding part 21 are brought into contact with and separated from each other according to a change in posture due to its own swing. The relative position adjustment link body 63 to which the moving force to the moving position of the holding means 20 by the moving means 40 is input and the holding means 20 are first engaged with each other. The first abutting member 64 that abuts the relative position adjustment link body 63 and swings the clamping part 31 and the holding part 21 away from each other when in the one movement position, and the clamping means 20 are moved third. When in location, and a second abutting member 65 allowed to swing in a direction to separate the clamping portion 31 and the holding portion 21 in contact with the relative position adjustment link member 63 equivalents, the.
[0039]
The guide plate 61 is fixed on the upper part of the sewing machine bed 103 and behind the needle plate 108. Hereinafter, when words indicating directions are used in the description of each part of the related operation means 60, the direction in a state where the guide plate 61 is fixedly mounted on the sewing machine bed 103 is indicated unless otherwise specified. To do.
On the upper surface of the guide plate 61, a guide groove 66 along the Y-axis direction is provided at an intermediate position in the X-axis direction. In the guide groove 66, the holding member 22 and the holding member 32 of the holding means 20 are stored in a state where they are overlapped with each other in the longitudinal direction, and further from above, the holding plate 22 is guided by the holding member 22 and the holding member 32. Cover so that it does not fall off the groove 66. As a result, the holding member 22 and the clamping member 32 are each guided by the guide groove 66 and can slide along the Y-axis direction. However, as described above, since the holding member 22 and the holding member 32 are connected via the tension spring 62, each member 22, 32 contacts the holding portion 21 and the holding portion 31 unless an external force is applied. The contacted state will be maintained. 7, 9, 11, and 13, the holding member 22 and the sandwiching member 32 are illustrated so that the widths in the X-axis direction are different, but this clearly shows the relative positional relationship between the members 22 and 32. For the sake of illustration, they are expressed differently. Actually, both the holding member 22 and the holding member 32 are set to be approximately equal to the width of the guide groove 66 in the X-axis direction within a range in which the holding member 22 and the holding member 32 can slide.
[0040]
Furthermore, through holes 68 and 69 are provided on both sides of the guide groove 66 of the guide plate 61, respectively. In one through hole 68, the engagement pin 26 provided in the holding member 21 is inserted from above, and in the other through hole 69, the engagement pin 39 of the holding member 32 is inserted. Further, each of the through holes 68 and 69 has an engagement pin in the movement of the holding means 20 from the first movement position to the third movement position and the relative movement of the holding member 22 and the holding member 32 associated therewith. The length in the Y-axis direction is set so that the front end and the rear end of each hole do not come into contact with 26 and 39, respectively. Further, the engaging pins 26 and 39 inserted through the through holes 68 and 69 have their tips protruding somewhat from the lower surface side of the guide plate 61 and individually engaged with the relative position adjusting link body 63.
[0041]
The relative position adjustment link bodies 63 are arranged along the longitudinal direction, and the rotation engagement portion 70 with the holding member 22, the rotation engagement portion 71 with the clamping member 32, and the movement located therebetween. A rotation engaging portion 72 with the means 40 is provided.
That is, the rotation engagement portion 70 with the holding member 22 is a long hole-like through hole along the longitudinal direction of the relative position adjustment link body 63, and the engagement pin 26 is inserted therethrough. The rotation engagement portion 71 with the holding member 32 is a circular through hole, and the engagement pin 39 is inserted therethrough. The rotation engaging part 72 with the moving means 40 is a long hole-like through hole along the longitudinal direction of the relative position adjusting link body 63, and the engaging protrusion 52 is inserted therethrough.
[0042]
FIG. 14 is an explanatory diagram viewed from below showing the relationship between the swinging operation of the relative position adjustment link body 63 and the change in the response position of the holding member 22 and the clamping member 32.
Referring to FIG. 14, as described above, the holding member 22 and the holding member 32 maintain the contact state between the holding unit 21 and the holding unit 31 by the tension spring 62 unless an external force is applied. This state is the upper thread holding state. The positions of the engaging pins 26 and 39 are set so that they are aligned at substantially the same position in the Y-axis direction when the holding portion 21 and the clamping portion 31 are in contact with each other. Accordingly, the relative position adjustment link body 63 connected to the engagement pins 26 and 39 via the rotation engagement portions 70 and 71 is also substantially in the X-axis direction in the normal state due to the tension of the tension spring 62. The state along is maintained (the state shown by the solid line in FIG. 14).
In such a state, for example, when a rotational force in the counterclockwise direction is applied to the relative position adjustment link body 63 by the movement force in the Y-axis direction from the engagement protrusion 52 of the moving means 40, the relative position adjustment link body 63 is rocked. Move and change its posture. At this time, the rotational engagement portions 70 and 71 are displaced in the Y-axis direction, so that an external force in a direction in which the holding portion 21 and the holding portion 31 are separated from each other is provided between the holding member 22 and the holding member 32. Will be granted. Accordingly, the holding portion 21 and the holding portion 31 are separated from each other against the tension of the tension spring 62, and the upper thread holding state is switched to the releasing state.
[0043]
The first contact member 64 will be described with reference to FIGS. The first abutting member 64 separates the holding portion 21 and the holding portion 31 when the holding means 20 is in the first movement position, and holds the holding portion 21 when moving from the first movement position to the second movement position. 21 and the clamping part 31 are moved in a direction in which they approach each other, and the swing of the relative position adjustment link body 63 is operated so as to come into contact with the second movement position.
[0044]
In order to realize the above operation, the first abutting member 64 rotates the rotation engaging portion 72 of the moving means 40 and the holding member 32 with respect to the relative position adjustment link body 63 located at the first movement position. It arrange | positions so that it may contact | abut from the front between the engaging parts 71. FIG. With this arrangement, when a forward moving force is applied to the relative position adjustment link body 63 by the movement means 40 in order to position the clamping means 20 at the first movement position, the relative position adjustment link body 63 is concerned. Swings with the contact point with the first contact member 64 as a fulcrum against the tension of the tension spring 62. At this time, the rotation engaging portion 71 of the holding member 32 moves rearward and the rotation engaging portion 70 of the holding member 22 moves forward as compared with the contact time. Accordingly, the holding portion 21 moves forward through the holding member 22 and the holding portion 31 moves rearward through the holding member 32, so that they are separated from each other (see the two-dot chain lines in FIGS. 6 and 14). . In such a state, the upper thread end portion is inserted between the holding portion 21 and the clamping portion 31.
[0045]
When the clamping means 20 moves from the first movement position to the second movement position, the contact state of the first contact member 64 with the relative position adjustment link body 63 is gradually released, so that the relative position adjustment is performed. The link body 63 is rotated clockwise by the tension of the tension spring 62. Therefore, the relative position adjustment link body 63 rotates clockwise until the contact state with the first contact member 64 is completely released, and the sandwiching portion 31 moves forward via the sandwiching member 32. The holding part 21 moves backward via the holding member 22. For this reason, clamping of the upper thread by the holding unit 21 and the clamping unit 31 is performed at a position behind the holding unit 21 at the first movement position and ahead of the clamping unit 31 at the first movement position. It becomes.
[0046]
The second contact member 65 will be described with reference to FIGS. The second abutting member 65 is relatively moved so that the holding portion 21 and the holding portion 31 that are in the holding state are moved away from each other again when the holding means 20 moves from the second movement position to the third movement position. The swing of the position adjustment link body 63 is operated.
[0047]
In order to realize the above operation, the second abutting member 65 is arranged in the X-axis direction with respect to the region through which the relative position adjustment link body 63 passes when the clamping means 20 moves from the second movement position to the third movement position. It arrange | positions so that the said relative position adjustment link body 63 may be slidably contacted from-side.
For this reason, with respect to the sliding contact portion 63a provided at the end on the X axis direction minus side of the relative position adjustment link body 63 that approaches the third movement position in a state substantially along the X axis direction (see FIG. 11). The second contact member 65 is in sliding contact. Since the sliding contact portion 63a of the relative position adjusting link body 63 has a shape in which the front side is gradually extended in the X-axis direction minus side, the relative position adjusting link body 63 moves further rearward after the sliding contact starts. The relative position adjusting link body 63 swings counterclockwise as shown in FIG. 13, and in this state, the clamping means 20 reaches the third movement position. By such swinging, the rotation engaging portion 71 of the holding member 32 moves rearward more greatly than the rotation engaging portion 70 of the holding member 22. As a result, the holding unit 21 and the clamping unit 31 are separated from each other (see FIG. 13). In this process, the upper thread end held between the holding part 21 and the clamping part 31 is released.
[0048]
(Arrangement of holding part and clamping part at each moving position)
As described above, when the holding means 20 is positioned at the first movement position, the holding unit 21 and the holding unit 31 move in directions away from each other. Then, when the first movement position is reached, as shown in FIG. 6, the holding portion 21 is located in front of the vertical movement path N of the sewing needle.
In addition, the sandwiching portion 31 has a distal end portion of the bent portion 36 positioned at least behind 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 108a (the position that becomes the Y-axis direction-side end of the diameter along the Y-axis direction of the circular needle hole 108a as viewed from below). This is a straight line determined by connecting the upper end of one of the race surfaces 128 on the rear side of the inner hook 122 arranged close to the rear side of the vertical movement path N. By setting the arrangement of the tip portion of the pinching portion 31 in this way, the upper thread loop by the first stitch in sewing is supplemented by the sword tip 121 of the inner hook 122 and expanded by the thread dividing portion 124b of the upper thread guide plate 124 (expansion). In this case, the tip of the pinching portion 31 is in contact with the upper thread and the yarn dividing portion 124b is not prevented from expanding the loop, and therefore, the upper thread is effectively prevented from contacting the race surface 128. Is possible.
The position of the holding portion 21 and the tip position of the holding portion 31 are determined by the lengths of the holding member 21 and the holding member 32 in the Y-axis direction and the contact position of the first contact member 64 with respect to the relative position adjustment link body 63. Is done. For example, if the contact position of the first contact member 64 is closer to the rotational engagement portion 72 of the moving means 40, the position of the holding member 21 is more forward, and the tip position of the clamping portion 31 is more rearward. Further, if the contact position is closer to the rotation engaging portion 71 of the holding member 32, the position of the holding portion 21 is further rearward, and the tip position of the holding portion 31 is further forward.
[0049]
A position where the holding unit 21 and the flat surface portion 30 of the clamping unit 31 come into contact with each other in the process in which the clamping unit 20 is positioned from the first movement position to the second movement position (hereinafter referred to as “clamping position”). As shown in FIG. 8, it is set near the vertical movement path N of the sewing needle, and is preferably closer. This is because the length of the upper thread end that hangs down from the clamping means 20 can be shortened by clamping the upper thread end at a position close to the sewing needle 104.
FIG. 8 is a diagram showing an example of a clamping position where the upper thread end is clamped, and the clamping position is located slightly on the side of the vertical movement path N of the sewing needle. The holding portion 21 and the clamping city 31 are configured to move together, and when the sewing needle 104 is in the vertical movement position below the needle plate 108, the holding portion 21 and the clamping portion 31 do not interfere with the vertical movement of the sewing needle 104. Therefore, the clamping position can be made closer to the vertical movement path N of the sewing needle, for example, on the vertical movement path N of the needle.
The distance from the clamping position to the vertical movement path of the sewing needle is also determined by the contact position of the first contact member 64 with respect to the relative position adjustment link body 63. For example, if the contact position of the first contact member 64 is close to the rotation engagement portion 72 of the moving means 40, the holding position is closer to the vertical movement path N, and the contact position is the rotation of the holding member 32. If it is close to the moving engagement portion 71, the holding position is far from the vertical movement path N.
[0050]
When the holding means 20 is positioned at the second movement position, the holding portion 21 and the holding portion 31 are already in contact with each other, so that the mutual arrangement is in agreement.
Note that the second movement position may be a position where the holding portion 21 and the clamping portion 31 are separated from the vertical movement path N of the sewing needle and do not interfere with the sewing needle 104.
When the clamping means 20 is positioned at the third movement position, the holding part 21 and the clamping part 31 may be separated by a distance that allows the upper thread to be released.
The third movement position may be a position where the holding portion 21 and the clamping portion 31 are separated from the vertical movement path N of the sewing needle and do not interfere with the sewing needle 104, but may interfere with other mechanisms necessary for sewing. In order to avoid this, it is set behind the second movement position.
[0051]
(Operation control means)
The operation control means 80 will be described with reference to FIG. FIG. 15 is a block diagram showing a control system of the sewing machine 100. Although not shown in detail, the control means 80 includes a CPU that performs various arithmetic processes, a ROM that stores various programs for various processes such as control and determination, and a RAM that is used as a work memory in various processes. And is roughly composed. The control means 80 includes a sewing machine motor 105, its encoder 109, a thread gripping motor 42, a first state sensor 47 of the moving position detection means 46, a second state sensor 48, and the like via a system bus and a drive circuit. An S / S (start / stop) switch 81 of the sewing machine 100 is connected.
[0052]
The control means 80 can recognize the rotation angle of the sewing machine motor 105 based on the pulse signal input from the encoder 109 provided on the output shaft of the sewing machine motor 105.
Further, the control means 80 can confirm each movement position of the clamping means 20 based on detection signals input from the first state sensor 47 and the second state sensor 48 of the movement position detection means 46.
Further, when a sewing start signal is input from the start switch 81, the control means 80 detects and recognizes the rotation angle of the sewing machine motor 105 and the operation position of the movement position clamping means 46, and the thread grip of the movement means 40 is detected. The drive of the motor 42 is controlled.
[0053]
(Description of sewing machine operation)
The operation of the sewing machine 100 having the above configuration will be described with reference to FIGS. FIG. 16 is a flowchart showing operation control of the sewing machine 100.
[0054]
First, the control means 80 performs first movement position detection (initial position detection) by the movement position detection means 46 based on the sewing start signal from the S / S switch 81 (step S1). Such detection is determined by whether or not both the first and second state sensors 47 and 48 are in the OFF state.
As described above, in the operation control 80, the clamping means 20 is positioned at the first movement position by the movement position detection means 46 when the main power is input. Therefore, the clamping means 20 is located on the vertical movement path N of the sewing needle, the holding part 21 is located in front of the vertical movement path N of the sewing needle, and the clamping part 31 is located behind the straight line M ( 6 and 7).
In addition, if any of the first or second state sensors 47 and 48 is detected to be in an ON state due to some factor despite being previously positioned at the first movement position, error processing (display, warning, etc.) (Step Sa1), the operation of each part of the sewing machine 100 is stopped (step Sa2), and the process is terminated.
[0055]
On the other hand, when the first and second state sensors 47, 48 are both detected to be OFF in step S1, the sewing machine motor 105 starts to be driven (step S2). As a result, the sewing needle 104 is inserted into the needle hole 108 a of the needle plate 108, and the upper thread passes between the holding portion 21 and the clamping portion 31. Further, below that, the upper thread loop on the side of the sewing needle 104 is captured by the sword tip of the shuttle mechanism 120. Then, the upper thread loop is widened by the rotation of the inner hook 122 and the upper thread guide plate 124. At this time, the leading end portion of the clamping portion 31 is located sufficiently rearward. Does not block the expansion of Accordingly, contact of the upper thread with the rear race surface 128 is prevented.
[0056]
Further, it is judged from the detection angle of the encoder signal whether or not the sewing needle 104 of the first stitch has come out of the cloth from the encoder 109 of the sewing machine motor 105 and the balance 107 has reached the top dead center (step S3). The process of step S3 is repeated until When the output of the encoder 109 indicates that the balance 107 has reached top dead center, the operation control means 80 starts driving the thread gripping motor 42 of the moving means 40 to move the clamping means 20 to the second moving position. Operation control is performed (step S4). That is, the storage of the rotation angle amount corresponding to the movement amount from the first movement position to the second movement position set in advance is referred to, and the thread gripping motor 42 is driven accordingly.
[0057]
Thereby, the clamping means 20 starts moving from the first movement position toward the second movement position. As a result, the relative position adjustment link body 63 of the related operation means 60 starts swinging along the X-axis direction by the tension of the tension spring 62, so that the holding portion 21 moves rearward and the clamping portion 31 moves forward. The holding part 21 and the planar part 30 of the clamping part 31 come into contact with each other as they move and approach each other (FIGS. 8 and 9). As a result, the upper thread end portion inserted between them is clamped. Since the holding portion 21 and the holding portion 31 that are located on both front and rear sides of the vertical movement path N of the sewing needle come into contact with each other, the holding position comes into contact with each other. The clamping position is closer to the vertical movement path N of the sewing needle than the arrangement.
The upper thread end is clamped by the holding part 21 and the clamping part 31 after the balance 107 reaches the top dead center because the lift of the balance with respect to the upper thread is completed at the top dead center of the balance 107. The upper thread at the lower position is in the shortest state, and when the upper thread is clamped by the holding part 21 and the clamping part 31 at this time, the length of the upper thread from the clamped part to the end can be shortened. Because it can.
[0058]
Since the nipping position is ahead of the second movement position, the nipping means 20 is further moved backward by the moving means 40. When the thread gripping motor 42 is driven and stopped for a preset rotation angle amount, the operation control means 80 confirms the outputs of the state sensors 47 and 48 of the movement position detection means 46 (step). S5). At the second movement position, the first state sensor 47 is in the ON state and the second state sensor 48 is in the OFF state, but any other state is detected for any one of the sensors 47 and 48. If this occurs, error processing (display, warning, etc.) is performed (step Sa1), the operation of each part of the sewing machine 100 is stopped (step Sa2), and the processing is terminated.
[0059]
In step S5, when each sensor indicates an appropriate state, sewing is continued while the upper thread is held by the clamping member 20. That is, the sewing machine 100 performs sewing after the second stitch (step S6). Note that the clamping means 20 that has reached the second movement position is only rearward, and the relative positional relationship between the holding part 21 and the clamping part 31 does not change after the upper thread is clamped. Therefore, even after reaching the second movement position, the upper thread end is held (FIGS. 10 and 11). The movement to the second movement position is completed while the needle point of the sewing needle 104 is above the needle plate 108.
[0060]
Next, the control means 80 determines whether or not a predetermined number of needle drops (for example, two needle drops) has been performed (step S7). The number of needle drops can be recognized as a predetermined number of needle drops, for example, by counting the number of signal outputs indicating 180 ° by the encoder 109.
If the control means 80 determines that the predetermined number of needle drops has not been performed (step S7; NO), the process of step S7 is repeated until the predetermined number of needle drops has been performed.
On the other hand, when the control means 80 determines that the predetermined number of needle drops has been performed (step S7; YES), the process proceeds to step S8.
[0061]
The operation control unit 80 performs operation control to start driving so that the thread gripping motor 42 of the moving unit 40 moves the clamping unit 20 to the third movement position (step S8). That is, referring to the storage of the rotation angle amount corresponding to the preset movement amount from the second movement position to the third movement position, the thread gripping motor 42 is driven in accordance with this.
[0062]
Thereby, the clamping means 20 starts moving from the second movement position toward the third movement position. When the clamping means 20 approaches the third movement position, the sliding contact portion 63 a of the relative position adjustment link body 63 of the related operation means 60 comes into sliding contact with the second contact member 65. When the movement of the clamping means 20 is further continued, the relative position adjustment link body 63 swings against the tension of the tension spring 62, and the clamping part 31 moves rearward larger than the holding part 21. Therefore, the clamping state of the upper thread end is released, and the upper thread end is released from the clamping means 20, while the clamping means 20 reaches the third movement position (FIGS. 12 and 13).
[0063]
After reaching the third movement position, the operation control means 80 confirms the outputs of the state sensors 47 and 48 of the movement position detection means 46 (step S9). At the third movement position, it is normal that the first state sensor 47 is in the ON state and the second state sensor 48 is in the ON state, but any other state is detected for any one of the sensors 47 and 48. If the error occurs, error processing (display, warning, etc.) is performed (step Sb1), and the processing is terminated.
[0064]
Next, the control means 80 determines whether or not sewing has been completed (step S10). When the control means 80 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 80 determines that the sewing has been completed (step S10; YES), the process proceeds to step S11.
[0065]
When the sewing is finished, the operation control means 80 outputs a drive signal to a thread trimming motor (not shown) of the thread trimming mechanism, and the driving force of the thread trimming motor 82 causes the upper thread by the thread trimming mechanism and the thread related to the sewing to be sewn. Thread trimming is performed (step S11).
Then, the operation control means 80 outputs a drive signal to the thread gripping motor 42 of the moving means 40, and the clamping means 20 moves from the third movement position to the first movement position by the driving force of the motor 42 (step S12). .
[0066]
Then, through these step S1 processing to step S12 processing (including step Sa1 processing, step Sa2 processing, and step Sb1 processing), one cycle related to sewing of the sewing machine 100 including the upper thread holding device 10 is completed.
As described above, the operation of the sewing machine 100 is performed.
[0067]
(Effect of embodiment)
The effect of the upper thread holding device 10 will be described with reference to FIGS. FIG. 17 is an explanatory diagram illustrating the pinching means 20 of the upper thread holding device 10 in a simplified manner with a two-dot chain line, and FIG. It is explanatory drawing shown in figure.
In the comparative example of FIG. 18, the holding portion 231 is close to the vertical movement path side of the sewing needle. Therefore, the upper thread loop is formed narrow by contact with the holding portion 231, and the guide hole of the upper thread guide plate 124 is formed. The yarn splitting by the yarn splitting portion 124b provided in 124a is not sufficiently performed, and the hook shaft side race surface 128 of the inner hook 122 is likely to contact.
On the other hand, when the pinching means 20 of the upper thread holding device 10 shown in FIG. 17 is located at the first movement position by the related operation means 60, the pinching portion 31 is behind (the hook) behind the straight line M (see FIG. 6). Since it is arranged on the shaft side), it can be separated from the vertical movement path of the sewing needle, and contact between the upper thread end and the clamping part 31 can be avoided when the upper thread end is held. Accordingly, the upper thread end does not come into contact with the hook shaft side race surface 128 of the inner hook 122, and the yarn separation by the yarn dividing section 124b is performed reliably, and the loop is greatly enlarged, and the upper thread end is contaminated with dirt and the hook. It is possible to effectively reduce the occurrence of entrainment.
On the other hand, the related operation means 60 moves the holding part 21 to the holding part 31 side and the holding part 31 to the holding part 21 side when the holding means 20 is moved from the first movement position to the second movement position. Thus, the position of the clamping part 31 when clamping can be moved to the vertical movement path N side of the sewing needle. As a result, the upper thread end is held in the vicinity of the vertical movement path N of the sewing needle, and the end side length of the upper thread end after the clamping can be shortened.
In particular, even when the clamping portion is retracted to a position away from the vertical movement path N of the sewing needle so that contact with the upper thread can be avoided as in this embodiment, Since the portion can be moved closer, it is possible to shorten the upper thread end after clamping while avoiding the upper thread end from contacting the inner hook 122.
[0068]
【The invention's effect】
According to the first aspect of the present invention, the clamping thousand steps move from the position where the sewing needle moves up and down toward the standing body portion of the sewing machine. The fact that the clamping means moves toward the vertical body side of the sewing machine means that the clamping means moves in the longitudinal direction of the sewing machine bed, and the clamping means is located closer to the tip than the vertical movement path of the needle of the sewing machine bed. It is not necessary to secure a space for moving the upper thread holding device, and it is possible to provide an upper thread holding device that can also be applied to the cylinder bed.
Further, when the clamping means moves from the first movement position to the second movement position, the holding part moves to the clamping part side, and the clamping part moves to the holding part side so that the upper thread end is clamped between them. Therefore, when the upper thread is clamped, the upper thread after clamping is located near the vertical movement path of the sewing needle without being arranged in the vicinity of the vertical movement path of the sewing needle in the first movement position. It is possible to shorten the end.
Accordingly, since the holding portion can be arranged away from the vertical movement path of the sewing needle at the first movement position, expansion by the upper thread guide plate of the upper thread loop scooped by the sword tip of the inner hook is not hindered. Thus, the restriction that the length of the upper thread remaining on the cloth back cannot be shortened can be eliminated because the clamping part cannot be arranged sufficiently close to the vertical movement path of the sewing needle. The length of the remaining upper thread end can be sufficiently shortened.
[0069]
According to a second aspect of the present invention, when the clamping means is in the first movement position, the tip of the clamping part connects the hook shaft side edge of the needle hole and the upper edge of the hook shaft side race surface of the intermediate hook. By arranging the hook on the hook shaft side from the straight line, it is possible to effectively avoid the contact between the holding part and the upper thread when the upper thread loop of the first stitch is spread by the upper thread guide plate, and the upper thread is in contact with the holding part. Occurrence of a situation of being brought close to the hook shaft side race surface side by contact can be effectively suppressed, and contact between the hook shaft side race surface and the upper thread can be prevented more effectively.
[0070]
According to the third aspect of the invention, the relative position adjusting link body swings the relative position adjusting link body, and both the holding portion and the clamping portion are brought into contact with and separated from each other, and the relative position adjusting link body is swung at the first and third moving positions. Since it has the abutting member to be squeezed, it is possible to move both the holding part and the clamping part and move them toward and away from each other with the movement of the clamping means to each moving position.
Therefore, it is possible to carry out the operation described in claim 1 or 2 with only one drive source for moving each movement position of the clamping means, improving the productivity of the apparatus and providing the control means. Even in this case, the control system can be simplified.
[Brief description of the drawings]
FIG. 1 is an overall side view with a part cut away showing an outline of a sewing machine.
FIG. 2 is a perspective view showing a main overall configuration of an upper thread holding device.
FIG. 3 is an exploded perspective view showing a main overall configuration of the upper thread holding device.
4 is a plan view of an upper thread guide plate as viewed from the U direction in FIG. 6;
FIG. 5 is a front view of the inner hook of the hook mechanism as viewed from the X-axis direction.
FIG. 6 is an operation explanatory view of the upper thread holding device as viewed from the right when the clamping means is in the first movement position.
FIG. 7 is an operation explanatory view of the upper thread holding device as viewed from below when the holding means is in the first movement position.
FIG. 8 is an operation explanatory view of the upper thread holding device in a state where the holding portion and the flat portion of the holding portion are in contact with each other before the second movement position, as viewed from the right side.
FIG. 9 is an operation explanatory view of the upper thread holding device as viewed from below in a state where the holding portion and the flat portion of the holding portion are in contact with each other before the second movement position.
FIG. 10 is an operation explanatory view of the upper thread holding device as viewed from the right when the clamping means is in the second movement position.
FIG. 11 is an operation explanatory view of the upper thread holding device as viewed from below when the clamping means is in the second movement position.
FIG. 12 is an operation explanatory view of the upper thread holding device as viewed from the right when the clamping means is in the third movement position.
FIG. 13 is an operation explanatory view of the upper thread holding device as viewed from below when the clamping means is in the third movement position.
FIG. 14 is an explanatory view seen from below showing the relationship between the swing operation of the relative position adjusting link body and the relative position change of the holding member and the holding member.
FIG. 15 is a block diagram showing a control system of the sewing machine.
FIG. 16 is an operation flowchart of the sewing machine.
FIG. 17 is a perspective view in which each configuration under the needle of the embodiment is partly cut away for explaining the effect of the embodiment.
FIG. 18 is a perspective view in which each configuration under the needle of the comparative example is partially cut away for explaining the effect of the embodiment.
[Explanation of symbols]
10 Upper thread holding device
21 Holding part
22 Holding member
31 Clamping part
32 Clamping member
40 Moving means
60 Related operation means
61 Guide plate (guide means)
62 Tension spring (tension biasing means)
63 Relative position adjustment link body
64 First contact member
65 Second contact member
100 sewing machines
104 Sewing needle
M Straight line connecting the hook shaft side edge of the needle hole and the upper edge of the hook shaft side race surface of the intermediate hook
N Vertical movement path of sewing needle

Claims (3)

At the beginning of sewing, the end of the upper thread inserted through the sewing needle is clamped below the needle plate and above the passing path of the sword tip with respect to the sewing needle of the intermediate hook driven by the hook shaft. In the upper thread holding device of the sewing machine, the end of the upper thread is moved to a position away from the vertical movement path of the sewing needle and the end of the clamped upper thread is released after a predetermined number of needle drops.
A holding portion that holds the end portion of the upper thread, and a holding portion that moves relative to the holding position and the release position with respect to the holding portion to sandwich and release the end portion of the upper thread. With
A first movement position located on the vertical movement path of the sewing needle; a second movement position spaced from the first movement position toward the vertical body part of the sewing machine with respect to the vertical movement path of the sewing needle; Clamping means for moving from a second movement position to a third movement position that is further away from the vertical movement path of the sewing needle toward the standing body side of the sewing machine;
Moving means for moving the clamping means from the first moving position to the second moving position at the start of sewing, and stopping from the second moving position to the third moving position after stopping for a predetermined number of stitches; ,
When the clamping means is located at the first movement position, the clamping part is arranged at a position closer to the standing body part of the sewing machine than the vertical movement path of the sewing needle, and the holding part is moved up and down by the sewing needle. Arranged in a position facing the clamping part across the path,
When the clamping means moves from the first movement position to the second movement position, both the holding portion and the clamping portion are moved in directions approaching each other to clamp the end portion of the upper thread and Moving the clamping means to the second movement position;
When the clamping means moves from the second movement position to the third movement position, or at the third movement position, the clamping part and the holding part are separated from each other so that the end part of the clamped upper thread is released. An upper thread holding device for a sewing machine comprising: related operation means for mechanically interlocking the holding portion and the holding portion with movement of the moving means. The related operation means includes
The arrangement of the tip of the clamping portion when the clamping means is located at the first movement position is determined between the hook shaft side edge of the needle hole provided in the needle plate and the hook shaft side race surface of the intermediate hook. From the straight line connecting the upper edge to the hook shaft side,
The position where the end portion of the upper thread is clamped by the holding portion and the clamping portion when the clamping means moves from the first movement position to the second movement position is set near the vertical movement path of the sewing needle. The upper thread holding device for a sewing machine according to claim 1, wherein: The clamping means has a holding member provided with the holding part, and a clamping member provided with the clamping part,
The related operation means includes
Guide means for supporting the holding member and the holding member so as to reciprocate in the direction along the shuttle shaft,
Tension urging means for constantly applying tension between the clamping member and the holding member in a direction in which the clamping unit and the holding unit approach each other;
The holding part and the holding part can be brought into contact with and separated from each other according to a change in posture due to their own swinging, and each of the moving positions of the holding means by the moving means is engaged with the holding member and the holding member. A relative position adjustment link body to which the moving force to is input,
A first abutting member that abuts on the relative position adjustment link body and swings the clamping part and the holding part apart in a direction in which the clamping means is in the first movement position;
A second abutting member that abuts on the relative position adjustment link body and swings the clamping part and the holding part away from each other when the clamping means is in the third movement position. ,
The relative position adjusting link body is configured to rotate along a longitudinal direction of the rotation engaging portion with the clamping member, the rotation engaging portion with the holding member, and the moving means positioned therebetween. A dynamic engagement portion is provided,
3. The first abutting member abuts at a position between a rotational engagement portion with the clamping member and a rotational engagement portion with the moving means. Upper thread holding device for sewing machines.

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