JP2008086427A - Pattern sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewing machine which can feed a cloth avoiding a needle thread that passes through an eye of a sewing needle from being wound around the sewing needle when feeding a processed cloth, can tighten the thread well, and can form neat stitches. <P>SOLUTION: When feeding the cloth during each of the sewing motions, an amount of cloth fed in X direction and an amount of cloth fed in Y direction based on a pattern data of a pattern are evaluated. After the point of the sewing needle moves above a needle plate, the cloth is first fed in -X direction by a predetermined small feed amount being the amount of cloth fed in X direction (for example around 0.5 mm), and then feeding of the cloth in -Y direction starts. Then feeding of the cloth in X direction based on the remaining amount of cloth fed in X direction and feeding of the cloth in Y direction based on the remaining amount of cloth fed in Y direction are executed. This process achieves avoiding the needle thread that passes through the eye of the sewing needle from being wound around the sewing needle, tightening the thread well, and forming neat stitches even if feeding of the cloth in Y direction is in the -Y direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pattern sewing machine that sews a pattern pattern while moving a cloth holding frame holding a work cloth in an X direction and a Y direction based on pattern data of a selected pattern pattern.

  Conventionally, a pattern sewing machine such as an electronic cycle sewing machine forms a pattern while moving a work cloth held by a cloth holding frame independently in the X direction and the Y direction. When a pattern pattern is sewn with this type of sewing machine, various fabric feed control devices have been proposed in which the fabric feed is controlled so that all stitches to be sewn are not stitch stitches but perfect stitches.

For example, the automatic sewing machine control device described in Patent Document 1 moves the cloth holding means in the X and Y directions by a servo motor driven based on the sewing data of the stitch pattern when sewing the stitch pattern. The stitch pattern is sewn in the forward direction, but if the stitch line length that causes hitch stitching in the sewing data is longer than a predetermined value, the cloth holding means is driven by the servomotor driven based on the reverse stitching data. Is moved in the X and Y directions to sew the stitch pattern in the reverse direction.
Japanese Patent Laid-Open No. 6-31065 (pages 3 to 5, FIGS. 2 and 4)

  In the automatic sewing machine control device described in Patent Document 1, the sewing direction is switched between the normal direction and the reverse direction based on the sewing data so as to avoid hitch stitches. Depending on the feed order in the Y direction, the upper thread may be entangled (wound) around the sewing needle. In this case, since the upper thread pulling resistance increases, there is a problem that upper thread pulling failure occurs, the thread tightening is poor, and a beautiful seam cannot be formed.

  For example, as shown in FIG. 13, the upper thread 9 is threaded through the eye of the sewing needle 18 from the rear (−Y direction) to the front (+ Y direction), and from the previous needle drop position N0 to the −X direction. In addition, a case where a stitch is formed at the next needle drop position Na in the −Y direction is shown. When the cloth is fed in the -X direction after the cloth is fed in the -Y direction first, the upper thread 9 threaded forward through the eye hole 18a is caught on the right side of the tip of the sewing needle 18. The left side of the sewing needle 18 is wound around the tip of the sewing needle 18, and the sewing needle 18 is stuck in the work cloth W in this winding state. In this case, as described above, the thread tightening is poor and a beautiful seam cannot be formed.

  On the other hand, as shown in FIG. 14, a case is shown in which a stitch is formed from the previous needle drop position N0 to the next needle drop position Nb that is in the + X direction and the −Y direction. When the cloth feed is executed in the + X direction after the cloth is fed in the -Y direction first, after the upper thread 9 threaded forward through the eye hole 18a is caught on the left side of the tip of the sewing needle 18. It happens to turn right so as to wind around the tip of the sewing needle 18, and the sewing needle 18 pierces the work cloth W in this wound state. In this case as well, the thread tightening is poor, and a beautiful seam cannot be formed.

  The object of the present invention is to feed the work cloth so that the upper thread inserted through the stitch hole of the sewing needle does not wrap around the sewing needle, so that the thread can be tightened and a beautiful stitch can be formed. It is to be.

  The pattern sewing machine according to claim 1 is an X direction in which a sewing mechanism including a sewing needle, a rotary hook, and a balance that are provided on a needle bar and driven by a motor, and a cloth holding frame that holds a work cloth on the upper surface of a needle plate are orthogonal to each other in a horizontal plane. And frame moving means that can be independently driven in the Y direction, the pattern sewing that can be sewn based on the pattern pattern data, with the X direction as the direction perpendicular to the main axis and the Y direction as the direction parallel to the main axis In the sewing machine, based on the pattern pattern data, the cloth feed is such that the X feed start timing for feeding the cloth in the X direction for each cloth feed of each sewing operation is earlier than the Y feed start timing for feeding the cloth in the Y direction. A cloth feed control means for determining the start timing is provided.

  The upper thread supplied from the thread supply source is threaded through the stitch hole of the sewing needle through the balance. In this case, the stitch holes of the sewing needle are formed in the Y direction, which is a direction parallel to the main shaft, and the upper thread is threaded from the Y direction rear side (−Y direction side) to the Y direction front side (+ Y direction side). ing. Therefore, when the cloth is fed for each sewing operation, the cloth feed in the X direction is executed before the cloth feed in the Y direction. Therefore, the upper thread inserted through the eye of the sewing needle is wound around the sewing needle. Without being determined, either the left side or the right side of the sewing needle is determined.

  That is, in the cloth feed in the −X direction, the upper thread is directed to the left side from the eye hole, and in the cloth feed in the + X direction, the upper thread is directed to the right side from the eye hole. Thus, after the direction of the upper thread extending from the eye hole with respect to the sewing needle is determined, the cloth is fed in the Y direction. Therefore, even if the Y-direction cloth feed is in the -Y direction and the upper thread is in the direction opposite to the insertion direction through which the eye thread is inserted, the upper thread does not wrap around the sewing needle. Therefore, the stitches at the next needle entry position after the cloth feeding is completed become beautiful and the thread tightening is improved.

  The pattern sewing machine according to claim 2, wherein the cloth feed control means feeds the cloth in the Y direction from the Y feed start timing after feeding the cloth in the X direction by a predetermined amount after the X feed start timing. It is.

  The pattern sewing machine according to claim 3 is the pattern sewing machine according to claim 2, wherein the cloth feed control means determines whether or not a predetermined amount of cloth feed in the X direction and cloth feed in the Y direction are possible at the time of cloth feed in each sewing operation. It has a cloth feed judging means for judging, and when receiving a judgment result indicating that the cloth feed is impossible from this cloth feed judging means, it instructs to reduce the rotational speed of the sewing machine motor.

  A pattern sewing machine according to a fourth aspect of the present invention is the pattern sewing machine according to the third aspect, wherein the cloth feed determining means stores speed feed amount information in which the rotation speed of the sewing machine motor is associated with the Y-direction cloth feed amount in each sewing operation. Therefore, the determination is made based on the speed feed amount information.

  The pattern sewing machine according to claim 5 is the pattern sewing machine according to any one of claims 1 to 4, wherein the exit position of the lower thread that exits from the rotary hook toward the needle hole of the needle plate is on the right side of the extension line of the vertical movement locus of the sewing needle. A lower thread exit detecting means for detecting whether the X direction feed amount based on the pattern data is smaller than a predetermined amount. Of the directions, the + X direction or the −X direction is determined based on the exit position received from the lower thread exit detection means.

  According to the first aspect of the present invention, the sewing machine and the frame moving means are provided, and the pattern can be sewn based on the pattern data of the pattern, with the X direction being a direction orthogonal to the main axis and the Y direction being a direction parallel to the main axis. In the pattern sewing machine, based on the pattern pattern data, the X feed start timing for feeding the cloth in the X direction at each cloth feed of each sewing operation is earlier than the Y feed start timing for feeding the cloth in the Y direction. Since the cloth feed control means for determining the cloth feed start timing is provided, first, by executing the cloth feed in the X direction, the upper thread is directed to the left side from the eye hole in the cloth feed in the -X direction. In the cloth feed in the + X direction, the upper thread is directed to the right side from the eye hole.

  That is, after the direction of the upper thread extending from the stitch hole of the sewing needle is determined, the cloth is fed in the Y direction. Therefore, the Y direction cloth feed is in the -Y direction, and the insertion direction in which the upper thread is inserted through the stitch hole. The upper thread does not wrap around the sewing needle even in the opposite direction, and the thread tightening at the next needle drop position after the cloth feeding is completed becomes good and the stitches become clean.

  According to the invention of claim 2, the cloth feed control means feeds the cloth in the Y direction from the Y feed start timing after feeding the cloth in the X direction by a predetermined amount after the X feed start timing. After the direction of the extending upper thread with respect to the sewing needle is determined, the cloth feed in the X direction and the cloth feed in the Y direction can be executed simultaneously, and the cloth feed time is not prolonged. Other effects similar to those of the first aspect are obtained.

  According to the invention of claim 3, the cloth feed control means determines whether or not a predetermined amount of cloth feed in the X direction and cloth feed in the Y direction are possible at the time of cloth feed of each sewing operation. If a determination result indicating that the cloth feed is impossible is received from the cloth feed determining means, a command is issued to decelerate the rotation speed of the sewing machine motor. By extending the possible period, it is possible to determine the direction of the lower thread with respect to the sewing needle at the time of cloth feeding for each sewing operation, and it is possible to reliably perform the cloth feeding for each sewing operation. Other effects similar to those of the second aspect are achieved.

  According to the invention of claim 4, the cloth feed determining means stores speed feed amount information in which the rotational speed of the sewing machine motor is associated with the Y-direction cloth feedable amount in each sewing operation. Since the determination is based on the quantity information, the cloth feed for each sewing operation can be performed with priority over the sewing speed. Other effects similar to those of the third aspect are achieved.

  According to the invention of claim 5, it is detected whether the exit position of the lower thread coming out from the rotary hook toward the needle hole of the needle plate is on the right side or the left side with respect to the extension line of the vertical movement locus of the sewing needle. A bobbin thread exit detecting means is provided, and the cloth feed control means, when the X direction feed amount based on the pattern data is smaller than a predetermined amount, the + X direction or -X direction of the X directions for executing the predetermined amount of cloth feed Is determined based on the exit position received from the bobbin thread exit detecting means, so even if the cloth feed amount in the X direction is “zero” or “substantially zero” smaller than the predetermined amount, the position in the X direction is determined. With a certain amount of cloth feed, the direction of the upper thread extending forward from the stitch hole of the sewing needle can be determined according to the exit position of the lower thread coming out of the rotary hook, that is, the + X direction or -X direction where no hitch stitch is generated. In addition, it is possible to reliably prevent the needle thread from being wound around the sewing needle. Can. Other effects similar to those of any one of claims 1 to 4 can be achieved.

  The pattern sewing machine according to the present embodiment drives the frame moving mechanism based on the pattern data of the pattern pattern to move the cloth presser device in the X direction and the Y direction, and sequentially feeds the cloth to the next stitch. When executing, the X direction cloth feed is started first, after the predetermined amount of cloth feed is executed in the X direction, the cloth feed in the Y direction is started, and the upper thread is not wound around the sewing needle and is beautiful. It can be sewn with.

  As shown in FIG. 1, the pattern sewing machine 1 includes a bed portion 5 and an arm portion 6 arranged on the upper surface side of the sewing machine table 3. A needle plate 7 is fixed to the front upper surface of the bed portion 5, and a presser foot device 8 is provided on the upper side of the needle plate 7.

  The cloth presser 8 holds an X-direction drive mechanism (not shown) that drives the feed plate 10 by the X-axis drive motor 45 while holding the work cloth W to be sewn by the cloth presser plate 12 and the feed plate 10. Via a Y-direction drive mechanism (not shown) driven by a Y-axis drive motor 47, and a front-back direction (Y direction) parallel to the main axis. To be moved. As shown in FIG. 2, the presser foot device 8 includes a feed plate 10 that can move back and forth and right and left on the needle plate 7, a presser arm 11 provided on the feed plate 10, and a front end portion of the presser arm 11. It is comprised from the rectangular frame-shaped cloth presser board 12 etc. which were attached so that raising / lowering was possible.

  The rectangular frame-shaped cloth presser plate (cloth holding frame) 12 is always urged and lifted by a spring and is away from the feed plate 10, but is urged by a presser solenoid 14 attached to the arm portion 6. When it is done, it descends to a position where it contacts the feed plate 10 and is movable in the X and Y directions in synchronism with the feed plate 10 while sandwiching the work cloth W between the feed plate 10 and the feed plate 10. ing. Here, the X-direction drive mechanism and the Y-direction drive mechanism that move the cloth presser plate 12 and the feed plate 10 in the X direction and the Y direction correspond to the frame moving means.

  The arm portion 6 is provided with a main shaft (not shown) in the front-rear direction, a needle bar 16 that reciprocates up and down, and a balance (not shown). A sewing needle 18 is attached to the lower end of the needle bar 16. ing. The bed 5 is provided with a vertical full rotary hook 25 (see FIG. 3) that forms a seam in cooperation with the sewing needle 18. A sewing mechanism is constituted by the needle bar 16 to which the sewing needles 18 are attached, the balance, the vertical full rotary hook 25 and the like. As shown in FIG. 1, an operation panel 20 operated by an operator is erected on the right side of the upper surface of the sewing machine table 3. The operation panel 20 is mainly operated when various commands for the pattern sewing machine 1 are input.

  As shown in FIG. 1, a control box 22 is provided below the sewing machine table 3. The control box 22 incorporates a control device 35 to be described later. On the lower side of the sewing machine table 3, a pedal-type start / stop switch 24 is arranged for starting / ending the sewing operation and switching the operation of raising and lowering the presser foot 12.

Next, a brief description will be given of a switching mechanism for switching the exit position of the lower thread DT from the vertical full rotary hook provided in the bed portion to the left or right side of the extension line N of the vertical movement locus of the sewing needle 18.
As shown in FIGS. 3 and 4, the vertical full rotary hook 25 is attached to the outer hook 26 that can be rotated by the lower shaft 32 and the outer hook 26 so as to be relatively rotatable with respect to the outer hook 26. The inner hook 27, a bobbin case 28 attached to the inner hook 27, and a hook stopper 29 attached to the needle plate 7 and restraining the inner hook 27 from rotating. The lower thread DT is wound around a lower thread bobbin (not shown) accommodated in the bobbin case 28. However, the eye hole 18a of the sewing needle 18 is formed in the front-rear direction, and the upper thread UT supplied from the balance is threaded through the eye hole 18a from the rear to the front.

  A lower thread guide portion 27a that integrally projects from the upper side of the inner hook 27 is formed, and a locking hole portion 27b into which a left side engaging portion 29a of a hook stopper member 29 described later is inserted into the lower thread guide portion 27a. Is formed. A locking wall portion 27c is formed at the right end of the lower thread guide portion 27a with respect to the locking hole portion 27b.

  By the way, as shown in FIG. 3, a thread tension spring 30 capable of adjusting the thread tension applied to the lower thread DT drawn out from the inner lower thread bobbin to the right shoulder portion of the outer peripheral wall of the bobbin case 28. Is attached. As shown in FIG. 5, two bobbin thread outlet holes 28 a and 28 b are provided on the outer peripheral wall of the bobbin case 28. The lower thread outlet hole 28a and the lower thread outlet hole 28b are arranged at positions facing each other across the center line Q in plan view. Accordingly, the lower thread DT passes between the thread tension spring 30 and the outer peripheral wall, and is drawn out from the lower thread outlet hole 28a or the lower thread outlet hole 28b through the tip of the thread tension spring 30. When the lower thread is pulled out from the lower thread outlet hole 28 a, the lower thread outlet of the lower thread DT extending from the vertical full rotary hook 25 is on the left side with respect to the extension line N of the vertical movement locus of the sewing needle 18. When the lower thread is pulled out from the lower thread outlet hole 28b, the lower thread outlet of the lower thread DT extending from the vertical full rotary hook 25 is on the right side with respect to the extension line N of the vertical movement locus of the sewing needle 18.

  A bifurcated portion including left and right engaging portions 29a and 29b is formed at the rear end portion of the plate-shaped hook stopper member 29, and the left engaging portion 29a is inserted into the locking hole portion 27b of the inner hook 27, and the right engaging portion. The joint portion 29b is in contact with the right edge of the locking wall portion 27c of the inner hook 27. That is, since the locking wall portion 27c is locked by the left and right engaging portions 29a and 29b, the rotation position of the inner hook 27 is positioned.

Next, the control system of the pattern sewing machine 1 will be described.
As shown in FIG. 7, the control device 35 is constituted by a computer including a CPU 36, a ROM 37, a RAM 38, and the like. The control device 35 includes a start / stop switch 24, a presser switch 39 for switching the presser arm 11 between a presser position and a presser release position, a spindle rotation angle detection sensor 40 for detecting the rotation angle of the spindle, and an operation panel. 20, a drive circuit 43 for the sewing machine motor 42, a drive circuit 44 for the presser solenoid 14 capable of switching the presser arm 11 to the presser position, a drive circuit 46 for the X-axis drive motor 45, and a Y-axis drive motor 47 And a lower thread outlet setting switch 34 for setting whether the outlet position of the lower thread outlet is the lower thread outlet hole 28a or the lower thread outlet hole 28b.

  The operation panel 20 is provided with a small liquid crystal display 20a, a numeric keypad 20b for inputting numerical values, switches 20c including various switches for setting sewing parameters, and the like.

  In the ROM 37, in addition to various control programs for controlling the pattern sewing machine 1 and a cloth feed control program unique to the present application described later, a plurality of pattern data for sewing a plurality of pattern patterns to be used for sewing are stored in advance. Yes. The ROM 37 further stores a speed feed amount table shown in FIG. In this speed feed amount table, the rotational speed of the sewing machine motor 42 and the Y-direction cloth feedable amount at the rotational speed are stored in association with each other.

  The RAM 38 is appropriately provided with a counter memory and a buffer which are necessary for sewing processing of a pattern pattern and executing a cloth feed control to be described later, such as a memory and a work memory for temporarily storing calculation results calculated by the CPU 36. Yes.

  Next, the cloth feed control executed by the control device 35 will be described based on the flowchart of FIG. However, the symbol Si (i = 11, 12, 13,...) In the figure is each step.

  When this control is started, first, it waits until a sewing start command is output from the start / stop switch 24 (S11: No). When a desired pattern pattern to be sewn is selected by the operator and the start / stop switch 24 is activated (S11: Yes), an initial value “1” is set to the count value N of the stitch counter (S12). The pattern data of the stitch number specified by the stitch count value N is read, and the X-direction feed amount XD and the Y-direction feed amount YD of this pattern data are calculated (S13).

  Next, the current rotational speed of the sewing machine motor 42 obtained from the sensor signal (encoder signal) input from the spindle rotation angle sensor 40 at a predetermined minute time and the data set in the speed feed amount table shown in FIG. Based on this, it is determined whether or not cloth feed is possible by adding a predetermined minute feed amount in the X direction (this is a predetermined amount, for example, about 2 mm) to the Y direction feed amount YD. If the X-direction feed amount XD is larger than a predetermined feed amount (for example, about 2 mm) (S15: Yes), the process waits until the feed start timing is reached (S16: No).

  When the sewing needle 18 moves to the upper side of the needle plate 7 and the feed start timing at which cloth feed is possible (S16: Yes), the cloth feed in the X direction is first performed before the cloth feed in the Y direction. The process is started (S17). Although not shown here, the X-axis drive motor 45 is driven pulse by pulse by motor drive control. Therefore, every time the X-axis drive motor 45 is driven by one pulse, it is determined whether or not the X-direction cloth feed has reached the predetermined minute feed amount (S18: No), and S18 is repeated. Executed.

  Next, when the X-direction cloth feed reaches a predetermined minute feed amount (S18: Yes), the Y-direction feed is started (S19). Thereafter, the Y-direction cloth feed of the Y-direction feed amount YD and the remaining X-direction cloth feed of the X-direction feed amount XD are executed in parallel. Therefore, when the X-direction cloth feed of the X-direction feed amount XD and the Y-direction cloth feed of the Y-direction feed amount YD are completed (S20: Yes), the stitch count value N indicates the final stitch. When there is no sewing, that is, when sewing is in progress (S21: No), the stitch count value N is incremented by one (S22), and the steps after S13 are repeated.

  When the stitch count value N is the final stitch and all the stitches are formed (S21: Yes), the process returns to S11. Based on the rotation speed of the sewing machine motor 42 and the data set in the speed feed amount table, when the cloth feed amount of the Y direction feed amount YD plus the predetermined minute feed amount in the X direction is impossible. (S14: No), the rotational speed of the sewing machine motor 42 is reduced so that the cloth feed amount can be fed, that is, the cloth feedable period is extended (S23).

  Incidentally, when the X-direction feed amount XD is equal to or less than the predetermined feed amount (S15: No), the lower thread exit position is detected based on the signal of the lower thread exit setting switch 34 (S24), and the dummy is based on the result. Specifically, the X direction (+ X direction or -X direction) for feeding the cloth in the X direction is set (S25). This dummy X-direction cloth feed is performed forward from the eye hole 18a of the sewing needle 18 so that hitch stitches are not generated even when the X-direction feed amount XD is “zero” or “substantially zero”. The direction (+ X direction or -X direction) of the extending upper thread UT with respect to the sewing needle 18 is set.

  That is, when the cloth feed is in the −X direction and the lower thread outlet setting switch 34 sets that the lower thread is coming out of the lower thread outlet hole 28a (see FIG. 3), that is, it extends from the vertical full rotary hook 25. When the lower thread exit of the lower thread DT is on the left side with respect to the extension line N of the vertical movement locus of the sewing needle 18, the “left side: −X direction” is forced so that the upper thread UT is placed on the left side with respect to the sewing needle 18. Is set automatically. However, when the cloth feed is in the + X direction and the lower thread outlet setting switch 34 sets that the lower thread is coming out of the lower thread outlet hole 28b (see FIG. 6), that is, the lower thread extending from the vertical full rotary hook 25 When the lower thread exit of the thread DT is on the right side with respect to the extension line N of the vertical movement locus of the sewing needle 18, “right side: + X direction” is forcibly set so that the upper thread UT is hooked on the right side with respect to the sewing needle 18. Is set.

  Next, the cloth feed is executed in the X direction (+ X direction or −X direction) set in S25 with the X direction feed amount XD and the dummy feed amount DD (for example, about 2 mm) less than the predetermined feed amount (S26). Then, the Y-direction feed by the Y-direction feed amount YD is executed (S27). Thus, even if the X-direction cloth feed is less than or equal to the predetermined feed amount, the direction of the upper thread with respect to the sewing needle has been determined, so the dummy feed amount DD that has been fed excessively is reversely fed (S28), and the steps after S20 are executed. Is done.

  Here, the control device 35 that executes the cloth feed control (S12 to S28) of FIG. 9 corresponds to the cloth feed control means. The control device 35 that executes S14 of the cloth feed control corresponds to the cloth feed determining means. The speed feed amount table data (FIG. 8) stored in the ROM 37 corresponds to the speed feed amount information. The control device 35 that executes S24 of the cloth feed control corresponds to the bobbin thread outlet detecting means.

Next, the operation and effect of the cloth feed control configured as described above will be described.
As shown in FIGS. 10 and 11, when the phase angle of the main shaft when the tip of the sewing needle 18 is at the uppermost position is 0 °, based on the rotational speed of the sewing machine motor 42 and the setting information of the speed feed amount table, the Y direction It is determined whether or not the cloth feed obtained by adding a predetermined minute feed amount in the X direction to the feed amount YD is possible within the feedable period. For example, the case where the X-direction feed amount XD for forming the next stitch Na after forming the current stitch N0 is “−2 mm” and the Y-direction feed amount YD is “−2 mm” will be described. To do.

  In this case, when the rotation speed of the sewing machine motor 42 is 2800 rpm or less, cloth feeding is possible. Therefore, at the start timing of the feedable period in which the tip of the sewing needle 18 has moved to the upper side of the needle plate 7, the cloth is first fed forward in the −X direction by a predetermined minute feed amount (for example, about 0.5 mm). When the cloth feed of a predetermined minute feed amount in the −X direction is completed, the cloth feed in the −Y direction is started. Thereafter, the remaining feed amount “1.5 mm” obtained by subtracting the predetermined minute feed amount “0.5 mm” from the X-direction feed amount XD is fed in the −X direction, and also in the −Y direction. The Y-direction feed amount YD “−2 mm” is fed.

  That is, as shown in FIG. 11, since the cloth feed is first fed in the −X direction by a predetermined minute feed amount, the sewing needle 18 moves in the + X direction by 0.5 mm from the needle drop position N0 at this time. This corresponds to the point “N0x” on the X axis. At this time, as shown in FIG. 12, the lower thread DT inserted through the eye hole 18 a of the sewing needle 18 from the rear to the front does not wrap around the sewing needle 18, but is directed to the previous stitch Na, that is, to the left. It extends. From this point of time, the remaining cloth feed in the -X direction is executed, and the cloth feed in the -Y direction is executed. As a result, as shown in FIGS. 11 and 12, the sewing needle 18 is positioned on the next stitch Na. At this time, the upper thread UT is directed to the previous needle drop position N0 without being wound around the sewing needle 18.

  By the way, when the X-direction feed amount XD is “−0.2 mm” close to “substantially zero” and the predetermined minute feed amount cannot be achieved by the first cloth feed in the X direction, the lower thread outlet setting switch 34. Is fed in the −X direction by a minute feed amount (about −2.2 mm) obtained by adding a dummy feed amount DD (for example, 2 mm) to the X direction feed amount XD. As a result, even if the X-direction cloth feed amount XD is “substantially zero”, the direction of the upper thread UT with respect to the sewing needle 18 can be set to a desired direction so that hitch stitches do not occur. However, in order to eliminate dummy extra cloth feed in the X direction, the dummy feed amount DD is reversely fed after the cloth feed is completed.

Next, a modified embodiment in which the above embodiment is partially modified will be described.
1) At the time of cloth feeding for each sewing operation, the predetermined minute feed amount that is first executed in the X direction is about 0.5 mm for driving the X-axis drive motor 45 by 10 pulses. An arbitrary feed amount may be used according to the thickness and type of the upper thread UT or the thickness of the sewing needle 18.

2) At the time of cloth feed for each sewing operation, the cloth feed start timing in the X direction was the start time of the cloth feed available period, but the cloth feed amount in the X direction and the Y direction is small, and the X If the direction cloth feed amount XD is larger than the Y direction cloth feed amount YD, the X direction cloth feed amount XD and half of the Y direction cloth feed amount YD are fed at the uppermost position of the sewing needle (0 ° of the main shaft). The X-direction cloth feed and the Y-direction cloth feed may be started individually at the feed start timing that ends, that is, the X-direction cloth feed may be started first.

3) When the cloth feed amount for each sewing operation is small and the sewing speed is slow, even if the X-direction cloth feed amount XD and the Y-direction cloth feed amount YD are added, the total fabric feed is within the cloth feedable period. In such a case, all the X-direction cloth feed amount XD may be fed first, and then all the Y-direction cloth feed amount YD may be fed.
4) In this embodiment, the lower thread outlet position is switched by the two lower thread outlet holes 28a and 28b provided in the bobbin case, and the lower thread outlet position setting switch 34 allows the controller 35 to recognize the lower thread outlet position. However, the bobbin case may be provided with one bobbin thread exit hole and a mechanism for moving the bobbin case to the left and right from the outside so that the controller 35 can recognize the position of the mechanism. Good.
5) In this embodiment, a vertical full rotary hook is described as a hook, but it can also be applied to a half rotary hook.

It is a perspective view of the pattern sewing machine which concerns on the Example of this invention. It is a principal part expansion partial perspective view of a pattern sewing machine. It is a front view of a vertical full rotary hook when the lower thread outlet hole is in the left position. It is a top view of a vertical full rotation hook. It is a top view of a bobbin. It is a front view of a vertical full rotary hook when the lower thread outlet hole is in the right position. It is a block diagram of a control system of a pattern sewing machine. It is a chart which shows the setting data of a speed feed amount table. It is a flowchart of cloth feed control. It is a time chart of the vertical movement of the sewing needle and the X-direction and Y-direction cloth feed. It is explanatory drawing explaining the movement locus | trajectory of a X direction cloth feed and a Y direction cloth feed. It is explanatory drawing explaining the positional relationship of a needle thread, a sewing needle, and a needle drop position. It is FIG. 12 equivalent figure which concerns on a prior art. It is FIG. 12 equivalent figure which concerns on a prior art.

Explanation of symbols

1 Pattern sewing machine 10 Feed plate 12 Work clamp plate 18 Sewing needle 16 Needle bar 34 Lower thread exit setting switch 35 Controller 37 ROM
45 X-axis drive motor 47 Y-axis drive motor W Work cloth

Claims (5)

A sewing mechanism that includes a sewing needle on the needle bar, a rotary hook, and a balance, and is driven by a motor, and a cloth holding frame that holds the work cloth on the top surface of the needle plate can be independently driven in the horizontal and X directions. Frame sewing means, wherein the X direction is a direction orthogonal to the main axis, and the Y direction is a direction parallel to the main axis.
Based on the pattern data of the pattern pattern, the cloth feed is performed so that the X feed start timing for feeding the cloth in the X direction for each cloth feed of each sewing operation is earlier than the Y feed start timing for feeding the cloth in the Y direction. A pattern sewing machine comprising a cloth feed control means for determining a start timing.   2. The pattern sewing according to claim 1, wherein the cloth feed control unit feeds the cloth in the Y direction from the Y feed start timing after feeding the cloth in the X direction by a predetermined amount after the X feed start timing. 3. sewing machine.   The cloth feed control means includes a cloth feed determining means for determining whether or not a predetermined amount of cloth feed in the X direction and a cloth feed in the Y direction are possible at the time of cloth feed in each sewing operation. 3. The pattern stitching sewing machine according to claim 2, wherein when a determination result indicating that cloth feeding is impossible is received from the determination means, a command is issued to decelerate the rotational speed of the sewing machine motor.   The cloth feed determining means stores speed feed amount information in which the rotational speed of the sewing machine motor is associated with the Y-direction cloth feedable amount in each sewing operation, and is determined based on the speed feed amount information. The pattern sewing machine according to claim 3, wherein: There is provided a lower thread outlet detecting means for detecting whether the lower thread exit position from the rotary hook toward the needle hole of the needle plate is on the right side or the left side with respect to the extension line of the vertical movement locus of the sewing needle. When the X-direction feed amount based on the pattern data is smaller than the predetermined amount, the cloth feed control means sets the + X direction or the −X direction out of the X directions for executing the predetermined amount of cloth feed to the lower side. 5. The pattern sewing machine according to claim 1, wherein the sewing machine is determined based on an exit position received from the yarn exit detecting means.

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