JP5059680B2 - Eyelet hole sewing machine - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eyelet-borehole sewing machine that performs overlock stitching on the periphery of an eyelet hole formed in a sewing object.

  Conventionally, as a kind of sewing machine, provided with a looper for forming a seam in cooperation with a sewing needle, with respect to the peripheral edge of an eyelet hole (sometimes a sleep hole) formed in a cloth as a sewing object, There is known a blind hole sewing machine capable of forming a stitch by automatically performing the stitching (see, for example, Patent Document 1).

  In addition, some eyelet sewing machines are provided with a cloth cutting mechanism for forming eyelet holes on a cloth as a sewing object fixedly set on a feed base by pressing (for example, patents). Reference 2).

  In such an eyelet sewing machine, during the sewing operation, the cloth is moved together with the feed base so that the sewing needle attached to the needle bar moves along the periphery of the eyelet hole formed in the cloth as the sewing object. While driving, the needle bar and the looper are driven by the driving mechanism to perform the over stitching around the periphery of the eyelet hole.

  That is, during the sewing operation of the eyelet sewing machine, the needle bar having the sewing needle attached to the lower end portion is reciprocated in the up and down direction in conjunction with the main spindle rotated by the driving force of the sewing machine motor. Each time the main shaft makes one revolution, the sewing needle moves from the edge of the eyelet hole H and the inner needle position IP adjacent to the edge that is the periphery of the eyelet hole H formed on the cloth C as the sewing object shown in FIG. The needle thread is swung by the needle swinging mechanism so that the needle drops alternately to the distant outer needle position OP, and in the inner needle cycle in which the sewing needle drops to the inner needle position IP, the needle thread one stitch before In the outer needle cycle in which the knotted seam is entangled with the lower thread, and the needle thread passes through the workpiece, the knot does not entangle with the lower thread. By forming a seamless seam, Made the eyelet H seam S of the overlock sewing the periphery of that so is formed.

  That is, in the overlock stitching of the eyelet hole H, the needle thread and the lower thread are knotted when the sewing needle moves from the outer needle cycle to the inner needle cycle.

  Therefore, the top dead center of the needle bar in the inner needle cycle is set as the initial position so that a thread drop does not occur by always forming a knot at the needle drop at the start of sewing. Note that, as described above, the eyelet sewing machine has one cycle constituted by two rotations of the main spindle of the sewing machine. Therefore, this cycle is divided at the bottom dead center of the needle bar, and the sewing needle is moved to the inner needle position IP. The half cycle in which the needle is dropped is called an inner needle cycle, and the half cycle in which the sewing needle is dropped to the outer needle position OP is called an outer needle cycle.

  Here, the binding portion is indicated by a symbol J in FIG. Further, the position indicated by the symbol SP in FIG. 6 in the inner needle position IP is the sewing start point at which the first needle drop occurs, and the sewing end point at which the position indicated by the symbol EP in FIG. 6 is the last needle drop. It is said that. The seam S in FIG. 6 shows a state viewed from the looper side that is the back side of the cloth C in the sewing state. Furthermore, in FIG. 6, the inner needle position IP is shown slightly apart from the edge of the eyelet hole H.

  Here, as shown in the timing chart of FIG. 7, the relationship between the rotational phase angle of the sewing machine main shaft and the position of the needle bar indicates that when the rotational phase angle of the sewing machine main shaft is 0 °, the needle bar moves to the inner needle cycle and the outer needle. The operation timing is set so that the needle bar is positioned at the bottom dead center of each of the inner needle cycle and the outer needle cycle when the rotational phase angle of the sewing machine main shaft is 180 °. Yes.

  Since one sewing cycle is constituted by two rotations of the sewing machine main shaft, for convenience of explanation, as shown in FIG. 7, the rotational phase angle of the sewing machine main shaft in one sewing cycle is set to 0 to 720 °. In the inner needle cycle, the rotational phase angles of the main spindle at the top dead center of the needle bar are 0 ° and 720 °, the rotational phase angles of the main spindle at the bottom dead center are 180 ° and 540 °, and the needle in the outer needle cycle The inner needle cycle and the outer needle cycle are distinguished from each other by setting the rotational phase angle of the main shaft of the sewing machine at the top dead center of the rod to 360 ° and the rotational phase angles of the main shaft of the sewing machine at the bottom dead center of 180 ° and 540 °.

  By the way, in an eyelet-punching sewing machine, an initialization operation (initialization operation) is performed when power is supplied to the sewing machine.

  As one of such initialization operations, an initialization operation of the needle bar position is performed. The initialization operation of the position of the needle bar is performed by detecting the position of the needle bar with a position sensor.

  As shown in FIGS. 8 and 9, the conventional position sensor 101 includes a photo interrupter 102 and a shielding plate 103.

  The photo interrupter 102 is attached to the sewing machine frame via a mounting plate (not shown), and the shielding plate 103 has a rotation ratio of 1/2 with respect to the sewing machine main shaft, that is, a shaft 104 that rotates once when the sewing machine main shaft rotates twice, For example, it is attached to a balance drive shaft and is rotationally driven in the direction indicated by the arrow in FIG. 8 in the sewing state.

  The shielding plate 103 is divided into four parts by alternately arranging two large-diameter parts and small-diameter parts, and the first large-diameter part 103a shown on the left side of FIG. 8 is an optical path of the photo interrupter 102. Is detected, and the position of the needle bar corresponding to 0 to 180 ° (exceeding 0 ° to 180 °) of the rotational phase angle of the main spindle of the sewing machine is detected, and an ON signal as the detection signal is output to the control means (not shown) Can be done. This control means is for controlling the operation of each part, and is mainly composed of a CPU and a memory.

  Further, the first small diameter portion 103b shown in the lower part of FIG. 8 adjacent to the downstream side in the rotation direction of the first large diameter portion 103a opens the optical path of the photo interrupter 102, and the rotation phase angle of the sewing machine main shaft is 180 to 180 °. The position of the needle bar corresponding to 360 ° (over 180 ° and below 360 °) can be detected, and an OFF signal as a detection signal can be output to the control means.

  Further, the second large-diameter portion 103c shown on the right side of FIG. 8 adjacent to the downstream side in the rotation direction of the first small-diameter portion 103b blocks the optical path of the photo interrupter 102, and the rotational phase angle 360 of the main spindle of the sewing machine is blocked. The position of the needle bar corresponding to ˜540 ° (exceeding 360 ° and not more than 540 °) can be detected, and an ON signal as the detection signal can be output to the control means.

  Furthermore, the second small-diameter portion 103d shown in the upper part of FIG. 8 adjacent to the downstream side in the rotation direction of the second large-diameter portion 103c opens the optical path of the photo interrupter 102, and the rotational phase angle 540 of the main spindle of the sewing machine. The position of the needle bar corresponding to ˜720 ° (exceeding 540 ° and 720 ° or less) can be detected, and an OFF signal as the detection signal can be output to the control means.

  A slit 103e that opens the optical path from the radially outer side toward the center at a position where the rotational phase angle of the sewing machine main shaft slightly exceeds 360 ° on the first small diameter portion 103b side of the outer periphery of the second large diameter portion 103c. The control means can determine that the position of the needle bar is in the outer needle cycle by changing the output signal.

  Here, a conventional initialization operation of the needle bar position will be described with reference to the flowchart of FIG.

  As shown in FIG. 10, the initialization operation for the position of the needle bar in the conventional eyelet sewing machine starts when the user turns on the power by turning on the power switch.

  In step ST52, the control means determines whether or not the output signal from the position sensor 101 is an ON signal. If the determination result is YES (ON signal), the control means proceeds to the next step ST53, and step ST53. Then, the sewing machine motor is reversely rotated (counterclockwise drive, hereinafter referred to as CCW drive) in the reverse direction to the rotational direction at the time of sewing, and the process proceeds to the next step ST54.

  Here, the sewing machine motor is CCW-driven in step ST53 because the position of the needle bar is in the range of 0 to 180 ° (inner needle cycle) of the rotational phase angle of the sewing machine spindle shown in FIG. 7 or 360 to 540 ° (outside This is because safety can be ensured by moving the head from the bottom dead center side toward the top dead center side.

  Next, in step ST54, the control means determines whether or not the output signal from the position sensor 101 has changed to an OFF signal. If the determination result is NO (ON signal continues), the control means returns to step ST52. On the other hand, if the determination result in step ST54 is YES (changed to an OFF signal), the control means proceeds to the next step ST55 and determines whether or not there is a slit 103e by generating an OFF signal by the slit 103e. Determine presence or absence. In step S55, when the determination result is NO (slit 103e “none”), the control means proceeds to step S56, and after the position sensor signal is determined to be OFF in step ST54, the sewing machine motor moves to a predetermined angle CCW. It is determined whether or not it has been driven. This predetermined angle is an angle at which the presence or absence of the slit 103e can be determined, and is an angle at which the main spindle of the sewing machine can be reversely rotated by an angle equal to or larger than the angle S shown in the output waveform of the position sensor in FIG.

  If the determination result in step S56 is NO (the sewing machine motor has not yet been driven by the predetermined angle CCW after the output signal of the position sensor 101 is turned off), the control means returns the process to step S55 to return to the predetermined angle. If the determination result of step S56 is YES (the sewing machine motor has been driven CCW by a predetermined angle after the output signal of the position sensor 101 is turned OFF), the slit 103e is detected. Therefore, it is determined that the position of the needle bar has reached the top dead center of the inner needle cycle, the process proceeds to the next step ST58, the drive of the sewing machine motor is stopped, and the initialization operation is terminated. As a result, the position of the needle bar is held at the initial position set at the top dead center of the inner needle cycle. The initial position is set in a range including 0 ° (720 °) of the rotational phase angle of the sewing machine main shaft, which is the top dead center of the inner needle cycle.

  If the determination result in step ST55 is YES (slit 103e “Yes”), the control means determines that the position of the needle bar has almost reached the top dead center of the outer needle cycle, and the next step The process proceeds to ST57, an error is displayed on the display screen in step ST57, and then the process proceeds to step ST58. In step ST58, the sewing machine motor is stopped and the process is terminated.

  Returning to the step ST52, if the determination result in the step ST52 is NO (OFF signal), the process proceeds to the next step ST59. In the step ST59, the machine motor rotates in the forward direction in the rotation direction at the time of sewing. Driving (clockwise driving, hereinafter referred to as CW driving) proceeds to the next step ST60.

  Here, the sewing machine motor is driven in CW in step ST59 because the position of the needle bar is in the range of 180 to 360 ° (outer needle cycle) of the rotational phase angle of the main spindle of the sewing machine shown in FIG. This is because safety can be ensured by moving the head from the bottom dead center side toward the top dead center side.

  Next, in step ST60, the control means determines whether or not the output signal from the position sensor 101 has changed to an ON signal. If the determination result is NO (OFF signal continues), the control unit returns to step ST59.

  If the determination result in step ST60 is YES (changed to an ON signal), the process proceeds to the next step ST61, and the control means determines whether or not there is a slit 103e in step ST61 and whether there is an OFF signal by the slit 103e. Determined by

  If the determination result in the step ST61 is YES (slit 103e “exists”), it is determined that the needle bar is located at substantially the top dead center of the outer needle cycle, the process proceeds to the step ST57, and the step ST57. In step ST58, an error is displayed on the display screen, and then the process proceeds to step ST58. In step ST58, the sewing machine motor is stopped and the process ends.

  If the determination result in step ST61 is NO (slit 103e “none”), it is determined in step ST62 whether or not the sewing machine motor has been driven by a predetermined angle CW after the position sensor signal is determined to be ON in step ST60. To do. The predetermined angle is an angle at which the presence or absence of the slit 103e can be determined, and is an angle at which the sewing machine main shaft can be rotated forward by an angle equal to or larger than the angle S shown in the output waveform of the position sensor in FIG. If the determination result in step S62 is NO (the sewing machine motor has not yet been driven at the predetermined angle CW after the position sensor signal is determined to be ON), the process proceeds to step ST61 to continue the CW drive at the predetermined angle. If the determination result in step S62 is YES (the sewing machine motor has been driven at a predetermined angle CW after the position sensor signal is determined to be ON), the needle bar is positioned at approximately the top dead center of the inner needle cycle. The process proceeds to step ST58 where the sewing machine motor is stopped and the initialization operation is terminated. Thereby, the position of the needle bar is held at the top dead center of the inner needle cycle, specifically, the initial position set within a predetermined range centering on the top dead center.

  If the position of the needle bar is moved to and maintained at the top dead center of the outer needle cycle, the position of the needle bar is moved to the top dead center of the inner needle cycle which is the initial position by manual operation of the operator. Thus, the error display is canceled, that is, a manual initialization operation for moving the needle bar position to the initial position by manual operation is performed.

  More specifically, in a state where the sewing machine motor is stopped, an operation handle (operation pulley) for manually operating the sewing machine motor is rotated to rotate the sewing machine main shaft once.

JP 2001-137484 A (FIG. 1) Japanese Patent Laying-Open No. 2001-334088 (FIG. 1)

  By the way, in the initialization operation of the position of the needle bar in the conventional eyelet sewing machine, the rotational phase angle of the sewing machine main shaft that moves the needle bar up and down during the initialization operation of the position of the needle bar is 0 to 180 ° and 540 to 540. In the case of 720 °, that is, in the inner needle cycle, it is moved and held at the initial position set at the top dead center of the inner needle cycle.

  However, when the rotational phase angle of the main spindle that moves the needle bar up and down at the time of turning on the power is 180 to 540 °, that is, in the outer needle cycle, it is not the top dead center of the inner needle cycle but the upper needle cycle. It is moved to the dead point and held, and an error is displayed.

  For this reason, moving the position of the needle bar to the top dead center of the outer needle cycle increases the operation amount when performing the manual initialization operation by the manual operation of the operator, that is, the movement amount of the needle bar. As a whole, there is a problem in that the initialization operation of the position of the needle bar cannot be performed efficiently, and a wasteful operation is required, that is, the usability is poor.

  Therefore, there is a demand for a eyelet-punching sewing machine that can easily improve the efficiency of the initialization operation of the needle bar position and improve the usability.

  The present invention has been made in view of this point, and an object of the present invention is to provide an eyelet sewing machine that can easily improve the efficiency and ease of use of the initialization operation of the needle bar position.

  In order to achieve the above-described object, the eyelet sewing machine according to the present invention is characterized by a needle bar having a sewing needle attached to the lower end portion in order to carry out sewing over the periphery of the eyelet hole formed in the sewing object. A needle bar drive mechanism that moves the needle bar up and down in conjunction with a sewing machine main shaft that is rotationally driven by a driving force of a sewing machine motor, and the needle bar is moved toward the edge of the eyelet hole every time the sewing machine main shaft rotates once. Eyelet having a needle swinging mechanism that swings alternately to an inner needle position and an outer needle position away from the edge of the eyelet hole, and control means for controlling the operation of each part In a boring machine, the needle bar causes the needle to fall to the inner needle position and the needle to the outer needle position in one rotation of the main spindle of the sewing machine since the needle bar is located at the bottom dead center. Any support with the outer needle cycle to drop A needle bar position detecting means for detecting whether the needle bar is positioned on the clue; and a top dead center front-and-rear range detecting means for detecting whether the needle bar is located in a range before or after the top dead center in any of the cycles; The control means is provided only when it is detected by the needle bar position detecting means that the position of the needle bar when the eyelet sewing machine is turned on is located in the inner needle cycle. The sewing machine motor is driven based on the detection result of the top dead center front-rear range detecting means to cause the needle bar to reach the top dead center of the inner needle cycle. By adopting such a configuration, when the needle bar is in the inner needle cycle, the sewing machine motor is driven to automatically move the needle bar to the initial position, which is the top dead center of the inner needle cycle. When the needle bar position is in the outer needle cycle, the needle bar position cannot be moved without driving the sewing machine motor.

  According to the eyelet hole sewing machine according to the present invention, only when the position of the needle bar is in the inner needle cycle, the sewing machine motor is driven to automatically move the position of the needle bar to the initial position. Since the needle bar position is not moved without driving the sewing machine motor during the outer needle cycle, it is possible to easily improve the efficiency and ease of use of the initialization of the needle bar position. There is an effect.

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

  FIG. 1 to FIG. 4 show an embodiment of an eyelet hole sewing machine according to the present invention, FIG. 1 is a partially cut schematic external view showing a configuration of a main part, and FIG. 2 is a configuration of a needle bar position detecting means. FIG. 3 is a timing chart showing the relationship between the rotational phase angle of the main spindle of the sewing machine, the position of the needle bar, and the detection signal from the needle bar position detecting means, and FIG. 4 is a block diagram showing the configuration of the main part. .

  The eyelet hole sewing machine of this embodiment has a basic configuration of a conventionally known eyelet hole sewing machine.

  As shown in FIG. 1, a sewing machine frame 2 of an eyelet hole sewing machine 1 according to the present embodiment is provided on a bed portion 2a having a substantially rectangular box shape and a rear portion of the bed portion 2a shown on the right side of FIG. The connecting body 2b projecting upward is provided extending from the upper part of the connecting body 2b to the front shown on the left side of FIG. 1 so as to extend in parallel with the bed 2a. It has an arm portion 2c and is formed in a substantially U shape as a whole. The sewing machine frame 2 is placed on a sewing machine table (not shown).

  Here, for convenience of explanation, the left side of the sewing machine body 2 shown in FIG. 1 is the front side FS, the right side of FIG. 1 opposite to the front side FS is the rear side BS, and the front side of the sewing machine body 2 shown in FIG. In the following, the back side of the sewing machine body 2 shown in FIG.

  Inside the arm portion 2c, a sewing machine main shaft 3 (upper shaft: only a part of which is shown in FIG. 1) is rotatable so that its longitudinal direction extends horizontally in the front-rear direction shown in the left-right direction in FIG. It is supported by. Further, at the substantially central portion in the longitudinal direction of the sewing machine main shaft 3, a secondary shaft (not shown) that intersects the sewing machine main shaft 3 so as to be orthogonal to the sewing machine main shaft 3 is rotated so as to extend horizontally in the left-right direction shown in the vertical direction of FIG. It is freely disposed along the left-right direction. One end of the auxiliary shaft is arranged so as to protrude outward from the right side surface 2ca shown on the front side in FIG. 1 among the side surfaces of the arm portion 2c, and the one end protruding outside is rotated by the operator. An operation handle (operation pulley) 4 to be operated is attached.

  The sewing machine main shaft 3 is directly driven to rotate by a sewing machine motor 5 (FIG. 4) such as an AC servo motor through a rotation transmission mechanism such as a toothed belt transmission. The auxiliary shaft is connected to the sewing machine main shaft 3 via a hypoid gear (not shown) by pushing the operation handle 4 and is formed so that the connection with the sewing machine main shaft 3 is released by pulling the operation handle 4 toward the front. Yes.

  Therefore, when the operator pushes the operation handle 4 in the stopped state of the sewing machine motor 5 and then rotates the operation handle 4 clockwise or counterclockwise, the sewing machine main shaft 3 is manually operated so that the rotation direction during the sewing operation is positive. It can be rotated (clockwise, hereinafter referred to as CW) or reversely rotated (counterclockwise, hereinafter referred to as CCW).

  A free end side of the arm portion 2c shown on the left side in FIG. 1 is a sewing head 6, and a needle bar 7 is disposed on the sewing head 6. The needle bar 7 is disposed so that the lower end of the needle bar 7 protrudes from the lower surface facing the bed 2 of the sewing head 6 toward the bed 2. A base end portion of the sewing needle 8 is detachably attached via a clasp. Further, the needle bar 7 can be reciprocated in a vertical direction with a predetermined stroke by a needle bar drive mechanism and a needle swing mechanism (both not shown), and in the front-rear direction shown in the left-right direction in FIG. 1 with a predetermined stroke. On the other hand, it can be swung along a right-and-left direction (perpendicular to the plane of FIG. 1) orthogonal thereto. As is conventionally known, the needle bar driving mechanism and the needle swinging mechanism are formed so as to be able to be driven in conjunction with the rotation of the sewing machine main shaft 3 that is rotationally driven by the driving force of the sewing machine motor 5.

  The bed portion 2 includes a looper portion 10 having a pair of left and right loopers facing the needle bar 7 and a pair of left and right spreaders (both not shown) for assisting these loopers. A looper base 11 is provided. These loopers and spreaders are driven in synchronism with the vertical movement of the needle bar 7 by a looper driving mechanism (not shown). Further, the looper drive mechanism is formed so as to be able to be driven in conjunction with the rotation of the lower shaft 12 that is directly driven to rotate by the sewing machine motor 5 through a rotation transmission mechanism such as a toothed belt transmission. The lower shaft 12 is disposed inside the bed portion 2 and has a rotation ratio of 1/2 with respect to the sewing machine main shaft 3. That is, the lower shaft 12 is configured to rotate once when the sewing machine main shaft 3 rotates twice.

  The lower shaft 12 may be driven by a driving force of a dedicated lower shaft driving motor such as a pulse motor instead of the sewing machine motor 5.

  A feed base 13 on which a cloth C (FIG. 6) as a sewing object is set is disposed on the upper surface portion of the bed portion 2, and an upper surface portion of the feed base 13 is a sewing object. A pair of pressers 14 for pressing the cloth C are provided. The feed base 13 is formed in a thin rectangular box shape having an open lower surface as a whole, and an upper opening is provided on the upper surface between the pair of pressers 14 in the front-rear direction. . The feed base 13 is driven by a feed mechanism (not shown) driven by a driving force of a pair of feed motors 15 such as a pulse motor and the like in the front-rear direction (left-right direction in FIG. 1) and the left-right direction (in FIG. 1). It is designed to move horizontally in the direction perpendicular to the paper surface.

  In the eyelet sewing machine 1 according to this embodiment, a cloth cutting device 16 (only a part of which is shown) for forming the eyelet H (see FIG. 6) in the cloth C as a sewing object is disposed.

  The eyelet sewing machine 1 according to the present embodiment has a first sensor 17 that detects half of one rotation of the sewing machine spindle 3 and turns off the other half, and a rotation ratio with respect to the sewing machine spindle 3 is 1/2. A second sensor 18 is provided for detecting that half of one rotation of the lower shaft 12 as an axis is ON and the other half is OFF.

  Note that the shaft whose rotation ratio to the sewing machine main shaft 3 is ½ is not limited to the lower shaft 12, and a dedicated shaft may be provided.

  The first sensor 17 includes a first shielding plate 17a attached to the sewing machine main shaft 3 and a first optical sensor 17b attached to the sewing machine frame 2 via an attachment stay (not shown). The first optical sensor 17b is electrically connected to the control means 19 to be described later, and turns on half of the needle bar 7 in one rotation of the sewing machine spindle 3 from the top dead center to the bottom dead center. The other half of the needle bar 7 positioned from the bottom dead center to the top dead center is turned OFF, and the detection signal, that is, the ON signal or the OFF signal can be output to the control means 19.

  The second sensor 18 includes a second shielding plate 18a attached to the lower shaft 12, and a second optical sensor 18b attached to the sewing machine frame 2 via an attachment stay (not shown). The second optical sensor 18b is electrically connected to the control means 19 to be described later. The detection signal, that is, the ON signal, is set such that half of one rotation of the lower shaft 12 is ON and the other half is OFF. Alternatively, it is configured so that an OFF signal can be output to the control means 19.

  As shown in FIG. 2, each of the first shielding plate 17 a and the second shielding plate 18 a includes an annular attachment portion 20 attached to the sewing machine main shaft 3 and the lower shaft 12 by screwing or the like, and an outer periphery of the attachment portion 20. And a meniscus-shaped shielding plate portion 21 extending radially outward from one end of the surface.

  Here, the detection signals from the first optical sensor 17b and the second optical sensor 18b will be specifically described with reference to the timing chart of FIG.

  As shown in FIG. 3, the relationship between the rotational phase angle of the sewing machine main shaft 3 and the position of the needle bar 7 is such that when the rotational phase angle of the sewing machine main shaft 3 is 0 °, the needle bar 7 has an inner needle cycle and an outer needle cycle. The operation timing is set so that the needle bar 7 is positioned at the bottom dead center of each of the inner needle cycle and the outer needle cycle when the rotational phase angle of the sewing machine main shaft 3 is 180 °. Yes. In the eyelet hole sewing machine 1 according to the present embodiment, one cycle of sewing is constituted by two rotations of the main spindle 3 of the sewing machine, as in the conventional case. The half cycle in which the sewing needle 8 is dropped to the inner needle position IP in one rotation of the sewing machine spindle 3 when the needle bar 7 is located at the bottom dead center is the inner needle cycle, and the sewing needle 8 is removed. A half cycle for dropping the needle to the needle position OP is called an outer needle cycle.

  Here, as shown in FIG. 3, the sewing machine main shaft 3 at the top dead center of the needle bar 7 in the inner needle cycle is set so that the rotational phase angle of the sewing machine main shaft 3 in one sewing cycle is 0 to 720 °, as in the conventional case. The rotation phase angle of the sewing machine main shaft 3 at the top dead center of the needle bar 7 in the outer needle cycle is set to 0 ° and 720 °, and the rotation phase angle of the sewing machine main shaft 3 at the bottom dead center is 180 ° and 540 °. The inner needle cycle and the outer needle cycle are distinguished from each other by setting the angle to 360 ° and the rotational phase angles of the main spindle 3 at the bottom dead center to 180 ° and 540 °.

  The first optical sensor 17b corresponds to the shielding plate portion 21 of the first shielding plate 17a attached to the sewing machine main shaft 3, and the rotational phase angle of the sewing machine main shaft 3 is 0 to 180 ° (over 0 ° and 180 °). Control means with detection signals at the time of 360 ° to 540 ° (over 360 ° and below 540 °: sometimes over 360 ° to below 540 °) as ON signals 19 can be output. The first optical sensor 17b has a rotational phase angle of the sewing machine main shaft 3 of 180 to 360 ° (over 180 ° and 360 ° or less: 180 ° or more and less than 360 °) and 540 to 720 ° (540 °). The detection signal at the time of exceeding 720 ° and below: 540 ° and below 720 °) may be output to the control means 19 as an OFF signal.

  Therefore, for example, when the sewing machine spindle 3 is rotating forward, the signal output from the first optical sensor 17b is the needle bar 7 in either the inner needle cycle or the outer needle cycle as shown in FIG. Needle bar across the top dead center so that an OFF signal is output before the top dead center (rotation phase angles 0 °, 360 °, and 720 ° of the main spindle 3) and an ON signal is output after the top dead center. The control means 19 switches the position of the needle bar 7 before and after the top dead center in either the inner needle cycle or the outer needle cycle according to the signal from the first optical sensor 17b. It is possible to detect in which range. In other words, the first optical sensor 17b functions as a range before and after the top dead center of the needle bar 7.

  The second optical sensor 18b corresponds to the shielding plate portion 21 of the second shielding plate 18a attached to the lower shaft 12, and the rotational phase angle of the sewing machine main shaft 3 interlocked with the lower shaft 12 is 0 to 180 ° ( 0 ° to 180 ° or less: 0 ° to less than 180 °) and 540 to 720 ° (over 540 ° to 720 ° or less: 540 ° to less than 720 °) Can be output to the control means 19 as an ON signal. The second optical sensor 18b has a rotational phase angle of 180 to 540 ° (over 180 ° and 540 ° or less: 180 ° or more and less than 540 ° in some cases) of the sewing machine main shaft 3 linked to the lower shaft 12. The detection signal can be output to the control means 19 as an OFF signal. This is because the lower shaft 12 is configured such that the rotation ratio with respect to the sewing machine main shaft 3 is 1/2, that is, the lower shaft 12 makes one rotation when the sewing machine main shaft 3 rotates twice.

  Of course, as the outputs from the first sensor 17b and the second optical sensor 18b, the ON signal and the OFF signal may be reversed.

  As said 1st optical sensor 17b and 2nd optical sensor 18b, a light-emitting device and a light receiver may be an individual thing, and a photo interrupter may be sufficient.

  A proximity sensor may be used instead of the first optical sensor 17b and the second optical sensor 18b.

  In the case where the sewing machine motor 5 is provided with a so-called Z-phase output that can output the output signal with half of one rotation of the output shaft turned ON and the other half turned OFF. Since the output signal (Z-phase output) of the sewing machine motor 5 can be used in place of the first sensor 17, it is not necessary to provide the first sensor 17 on the sewing machine main shaft 3 individually. In this case, it is important that the rotation ratio between the output shaft of the sewing machine motor 5 and the sewing machine main shaft 3 is 1: 1.

  By the second sensor 18, the needle bar 7 of the present embodiment causes the needle needle 7 to drop the needle 8 to the inner needle position IP (see FIG. 6) and the needle 8 to the outer needle position OP (see FIG. 6). The needle bar position detecting means is configured to detect which cycle is divided with the bottom dead center of the needle bar 7 between the outer needle cycle to drop the needle and the needle bar 7).

  As shown in FIG. 4, the control means 19 is for controlling the operation of each part of the eyelet sewing machine 1 of the present embodiment. Like the microcomputer, the control means 19 is a CPU 23 (MPU) that functions as at least an arithmetic unit. The memory 24 and a system controller (not shown).

  The control means 19 of this embodiment includes at least various drive motors such as a sewing machine motor 5 that drives a needle bar drive mechanism, a needle swing motor 9 that drives a needle swing mechanism, and a feed motor 15 that drives a feed mechanism, and top dead Various sensors used for detection of various operations such as the first optical sensor 17b of the point front-rear range detection means and the second optical sensor 18b of the needle bar position detection means, and a power switch used for supplying and stopping power 25, various operation switches such as a start switch used for starting and stopping a sewing operation, and display means 26 having a display screen used for displaying various information are electrically connected. In accordance with a control command sent from the CPU 23, the operation control of each part of the eyelet-cutting sewing machine 1 is performed. Note that a part of the operation switch, for example, a switch for inputting information such as the shape and size of the eyelet hole H, and the display unit 26 may be integrally configured by a touch panel.

  The memory 24 includes at least ROM and RAM having appropriate capacities, and an auxiliary storage device such as a removable memory card or a flash memory is used in combination with the design concept.

  The memory 24 is provided with at least a needle bar initialization operation setting unit 27. The needle bar initialization operation setting unit 27 of the present embodiment includes the first optical sensor 17b and the second optical sensor 18b during the initialization operation of the position of the needle bar 7 that is performed when the eyelet sewing machine 1 is turned on. Only when it is detected by the detection signal that the position of the needle bar 7 is in the inner needle cycle, the needle bar 7 is moved in the inner needle cycle based on the detection position of the needle bar detected by the first optical sensor 17b. A program and data for reaching the initial position which is the top dead center are stored. A specific example of the operation of initializing the position of the needle bar 7 performed based on the program and data stored in the needle bar initialization operation setting unit 27 will be described in detail later.

  The memory 24 forms the eyelet hole H in the program C and data for processing various kinds of information necessary for executing the sewing operation for performing the stitching operation on the periphery of the eyelet hole H, and the cloth C as the sewing object. Program and data for processing various information necessary for the operation, program and data for executing the initialization operation of the position of each part driven by each drive mechanism such as the feed base 13 excluding the needle bar 7, and operating system Device drivers are also stored.

  Since other configurations are formed in the same manner as a conventional eyelet-holed sewing machine, detailed description thereof is omitted.

  Next, the operation of the present embodiment having the above-described configuration will be described.

  FIG. 5 is a flowchart for explaining the initialization operation of the position of the needle bar when the power is turned on in the embodiment of the eyelet sewing machine according to the present invention.

  Various operation controls such as the sewing operation except for the initialization operation of the needle bar position are the same as the conventional ones. Therefore, only the initialization operation of the needle bar position which is the gist of the present invention will be described below. To do.

  As shown in FIG. 5, the operation of initializing the position of the needle bar 7 in the eyelet sewing machine 1 of this embodiment is started when the operator turns on the power switch 25. It should be noted that after the power switch 25 is turned on, an operation for initializing the position of the needle bar 7 may be started by further turning on a not-shown preparation switch (key). In step ST01, when the power is turned on, the control unit 19 determines whether the output signal from the second optical sensor 18b is an ON signal based on the program and data stored in the needle bar initialization operation setting unit 27. If the determination result is YES (ON signal), the position of the needle bar 7 is 0 to 180 ° (inner needle cycle) or 540 to 720 of the rotational phase angle of the sewing machine spindle 3 shown in FIG. It is determined that it is in the range of ° (inner needle cycle), and the process proceeds to the next step ST02.

  Next, in step ST02, the control means 19 determines whether or not the output signal from the first optical sensor 17b is an ON signal. If the determination result is YES (ON signal), the position of the needle bar 7 is determined. 3, it is determined that the rotational phase angle of the sewing machine main shaft 3 is in the range of 0 to 180 ° (after the top dead center of the inner needle cycle), and the process proceeds to the next step ST03. The sewing machine motor 5 is driven CCW so as to reach the top dead center of the inner needle cycle, and the process proceeds to the next step ST04.

  Here, the sewing machine motor 5 is CCW-driven in step ST03 when the position of the needle bar 7 is 0 to 180 ° (after the top dead center of the inner needle cycle) of the rotational phase angle of the sewing machine spindle 3 shown in FIG. Since it is within the range, safety can be ensured by driving the sewing machine main shaft 3 from 180 ° side to 0 ° side of its rotational phase angle to move the needle bar 7 upward. is there.

  Next, in step ST04, it is determined whether or not the output signal from the first optical sensor 17b is an OFF signal, that is, whether or not the ON signal has changed to an OFF signal, and the determination result is NO (ON signal continues). Since the needle bar 7 is moving toward the top dead center of the inner needle cycle, the process returns to step ST03 until the determination result in step ST04 is YES, that is, the output from the first optical sensor 17b. The CCW drive of the sewing machine motor 5 is continued until the signal changes from the ON signal to the OFF signal.

  If the determination result in step ST04 is YES (changed to an OFF signal), it is determined that the position of the needle bar 7 has reached the top dead center (0 °) of the inner needle cycle, and the next step ST05 is performed. In step ST05, the sewing machine motor 5 is stopped and the initialization operation is terminated. Thereby, the position of the needle bar 7 is held at the initial position set at the top dead center of the inner needle cycle.

  The initial position may be set in a range including 0 ° (720 °) of the rotational phase angle of the sewing machine main shaft 3 that is the top dead center of the inner needle cycle, and is not limited to the top dead center.

  Returning to the step ST02, if the determination result in the step ST02 is NO (OFF signal), the position of the needle bar 7 is 540 to 720 ° (inner needle) of the rotational phase angle of the sewing machine spindle 3 shown in FIG. In step ST06, the sewing machine motor 5 is driven in CW so that the needle bar 7 reaches the top dead center in step ST06, and the next step Proceed to ST07.

  Here, the CW drive of the sewing machine motor 5 in step ST06 is performed when the position of the needle bar 7 is 540 to 720 ° (before the top dead center of the inner needle cycle) of the rotational phase angle of the sewing machine spindle 3 shown in FIG. Since it is in the range, safety can be ensured by driving the sewing machine main shaft 3 from the 540 ° side to the 720 ° side of the rotational phase angle to move the needle bar 7 upward. is there.

  Next, in step ST07, it is determined whether or not the output signal from the first optical sensor 17b is an ON signal, that is, whether or not the signal has changed from an OFF signal to an ON signal, and the determination result is NO (OFF signal continues). Since the needle bar 7 is moving toward the top dead center of the inner needle cycle, the process returns to step ST06 until the determination result in step ST07 becomes YES, that is, the output from the first optical sensor 17b. The CW drive of the sewing machine motor 5 is continued until the signal changes from the OFF signal to the ON signal.

  If the determination result in step ST07 is YES (changed to an ON signal), it is determined that the position of the needle bar 7 has reached the top dead center (720 °) of the inner needle cycle, and the process proceeds to step ST05. In step ST05, the sewing machine motor 5 is stopped and the initialization operation is terminated. Thereby, the position of the needle bar 7 is held at the initial position set at the top dead center of the inner needle cycle.

  Returning to step ST01, if the determination result in step ST01 is NO (OFF signal), the position of the needle bar 7 is 180 to 540 ° (outer needle) of the rotational phase angle of the sewing machine spindle 3 shown in FIG. In step ST08, an error is displayed on the display screen of the display means 26, and the sewing machine motor 5 is not driven and held in a stopped state. finish.

  When the position of the needle bar 7 is in the outer needle cycle, the error display is canceled by moving the position of the needle bar 7 to the top dead center of the inner needle cycle, which is the initial position, by an operator's manual operation. Then, a manual initialization operation for moving the position of the needle bar 7 to the initial position by manual operation is performed.

  Specifically, the operation is performed by rotating the operation handle 4 for manually operating the sewing machine motor 5 and rotating the sewing machine main shaft 3 while the sewing machine motor 5 is stopped.

  At this time, when the operator manually operates the operation handle 4 to move the position of the needle bar 7 to the top dead center of the inner needle cycle which is the initial position, the output signal from the first optical sensor 17b changes. When the output signal of the first optical sensor 17b changes, the error display is canceled and the manual initialization operation ends.

  The error display is canceled based on the program and data stored in the needle bar initialization operation setting unit 27.

  As described above, according to the eyelet sewing machine 1 of the present embodiment, when the position of the needle bar 7 is initialized, it is determined whether or not the position of the needle bar 7 is in the inner needle cycle. When it is determined that the needle is in the needle cycle, the needle bar 7 is moved to reach the top dead center of the inner needle cycle. Therefore, when the needle bar 7 is in the inner needle cycle, the sewing machine motor 5 can be driven to automatically move the needle bar 7 to the initial position.

  Further, according to the eyelet hole sewing machine 1 of the present embodiment, when the position of the needle bar 7 is initialized, when the position of the needle bar 7 is in the outer needle cycle, the sewing machine motor 5 is not driven. Since the position of the needle bar 7 is not moved, the operation amount when the manual initialization operation for moving the position of the needle bar 7 in the outer needle cycle to the initial position by manual operation, that is, the movement amount of the needle bar 7 is set. Thus, the position of the needle bar at the top dead center of the outer needle cycle in the conventional manual initialization operation can be reduced as compared with the case where the needle bar is moved to the initial position.

  Therefore, according to the eyelet-punching sewing machine 1 of the present embodiment, when the position of the needle bar 7 is in the outer needle cycle, the needle bar 7 is not moved by causing the sewing machine motor 5 to perform a useless operation. Only when the position is in the inner needle cycle, it is possible to move to the top dead center, which is the initial position, and therefore it is possible to easily improve the efficiency and ease of use of the initialization operation of the position of the needle bar 7. .

  Here, the second optical sensor 18b as the needle bar position detecting means of the eyelet sewing machine 1 of this embodiment is only used for detecting whether the position of the needle bar 7 is in the inner needle cycle or the outer needle cycle. In addition, since it is also used for adjusting the timing of operation control of each part of the sewing machine such as the bobbin thread feeding timing, the overall cost does not increase compared to the case where a dedicated sensor is provided.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.

1 is a partially cut schematic external view showing a configuration of a main part of an embodiment of an eyelet sewing machine according to the present invention. The perspective view which shows the structure of the needle bar position detection means of FIG. FIG. 1 is a timing chart showing the relationship between the rotational phase angle of the sewing machine spindle, the position of the needle bar, and the detection signal from the needle bar position detecting means. The block diagram which shows the structure of the principal part of FIG. The flowchart explaining the initialization operation | movement of the position of the needle bar at the time of power activation in the embodiment of the eyelet-punching sewing machine according to the present invention. Explanatory drawing explaining the eyelet hole and its seam Timing chart showing the relationship between the rotational phase angle of the sewing machine main shaft, the position of the needle bar, and the detection signal from the position sensor in a conventional eyelet sewing machine Schematic front view showing the main part of a position sensor in a conventional eyelet-holed sewing machine Plan view of FIG. Flowchart for explaining the operation of initializing the position of the needle bar in a conventional eyelet sewing machine

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eyelet hole sewing machine 3 Sewing machine spindle 4 Operation handle 5 Sewing motor 7 Needle bar 8 Sewing needle 9 Needle swing motor 10 Looper part 12 Lower shaft 13 Feed stand 15 Feed motor 17 1st sensor 17a 1st optical sensor 17b 1st shielding board 18 2nd sensor 18a 2nd optical sensor 18b 2nd shielding board 19 Control means 21 Plate part 23 for shielding 23 CPU
24 Memory 25 Power switch 26 Display means 27 Needle bar initialization operation setting part FS Front side BS Rear side C Cloth H Eyelet hole IP Inner needle position OP Outer needle position S Seam J Knot part SP Sewing start point EP

Claims (1)

In order to overlock the edge of the eyelet hole formed in the sewing object,
A needle bar drive mechanism that moves the needle bar, with a sewing needle attached to the lower end, up and down in conjunction with a sewing machine main shaft that is rotationally driven by the driving force of the sewing machine motor;
The needle bar is swung so that the sewing needle alternates between the inner needle position on the edge side of the eyelet hole and the outer needle position away from the edge of the eyelet hole every time the main spindle of the sewing machine makes one rotation. A needle swing mechanism;
In the eyelet-punching sewing machine having control means for controlling the operation of each part,
In one rotation of the main spindle of the sewing machine since the needle bar is located at the bottom dead center, the needle bar causes the needle needle to drop the sewing needle to the inner needle position and the outer needle cycle to drop the needle to the outer needle position. Needle bar position detecting means for detecting which cycle of
A top dead center front-rear range detecting means for detecting whether the needle bar is located in either front or rear range across the top dead center in any one of the cycles,
The control means is the range before and after the top dead center only when the position of the needle bar at the time of turning on the eyelet sewing machine is detected by the needle bar position detecting means to be located in the inner needle cycle. An eyelet-punching sewing machine configured to drive the sewing machine motor based on the detection result of the detection means so that the needle bar reaches the top dead center of the inner needle cycle.

Images