JP2010142536A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewing machine which when sewing a first stitch after setting an intermittent presser foot and a throat plate in the same position in starting sewing, prevents the intermittent presser foot from colliding with the throat plate thereby preventing generation of noise due to the collision between the intermittent presser foot and the throat plate in bobbin winding processing. <P>SOLUTION: When the bobbin winding processing is performed, a default value stored in a RAM 64 is first read to lift the intermittent presser foot 6 to a position shown by the default value (5 mm above an upper surface of the throat plate 2a) (S30). Then, a sewing machine motor 72 is started to perform bobbin winding processing by a bobbin winding mechanism 50. When the bobbin winding processing is performed, a start pedal 70 enters an OFF waiting state. When a worker turns off the start pedal 70 (S32: Yes), the sewing machine motor 72 is stopped (S33), after that, the intermittent presser foot 6 is lowered to a preset position (S34), then operation of the sewing machine is returned to the S3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sewing machine, in particular, an intermittent presser that prevents the work cloth from being lifted when the sewing needle is raised, an intermittent presser position changing mechanism that can change the position of the intermittent presser, and a lower thread in conjunction with the rotation of the spindle. The present invention relates to a device provided with a bobbin winding mechanism that winds the bobbin.

  Conventionally, when forming a seam on a work cloth, an intermittent presser drive device that moves the intermittent presser up and down in synchronization with the vertical movement of the needle bar is provided to prevent the work cloth from lifting when the sewing needle is raised. Sewing machines are popular.

In the sewing machine described in Patent Document 1, switching that switches the setting position of the intermittent presser between the use position where the work cloth can be pressed by the vertical movement of the intermittent presser during sewing and the standby position above the use position. A mechanism (corresponding to an intermittent presser position changing mechanism) is provided. Since the position of the intermittent presser can be freely set, it can be set to an appropriate position according to the thickness of the work cloth.
Therefore, in this sewing machine, the lower limit position of the intermittent presser is set at the same position as the upper surface of the needle plate at the start of sewing, and the upper thread is sandwiched between the work cloth and the intermittent presser to prevent the thread from coming off at the start of sewing. After the upper and lower threads are entangled, it is possible to use the intermittent presser by moving the position of the intermittent presser slightly upward.

The prevention of thread dropout will be described in a little more detail.
In order to form a stitch in which the upper thread is entangled with the lower thread, the upper thread needs to go around the bobbin. In the sewing machine, the balance loosens the upper thread and the hook pulls the upper thread to rotate it, and then the balance pulls up the upper thread that the hook retracts to form a seam.
However, since the upper thread end that has passed through the stitch hole of the sewing needle is not restrained anywhere at the start of sewing, when the hook performs the operation of pulling the upper thread, the hook also draws the upper thread end. There was a problem that the upper thread could come out of the eye hole.

  In order to solve the problem, the lower limit position of the intermittent presser is set at the same position as the upper surface of the needle plate. Since the vertical movement of the intermittent presser is synchronized with the needle bar, considering the thickness of the work cloth, it is intermittent during the period when the sewing needle is stuck in the work cloth, that is, the hook is pulling the upper thread. The upper thread end portion is sandwiched between the presser and the work cloth, and the upper thread end portion can be prevented from coming out of the stitch hole of the sewing needle.

Further, as disclosed in Patent Document 2, a sewing machine equipped with a bobbin winding mechanism for winding a lower thread around a bobbin in conjunction with the rotation of the main spindle of the sewing machine has become widespread. In a sewing machine equipped with a bobbin winding mechanism, when the start pedal is depressed while pressing the bobbin winding key on the operation panel, the bobbin winding process is performed by rotating only the main spindle of the sewing machine without moving the XY table.
JP 2008-43360 A JP 7-275549 A

  In a sewing machine that emphasizes productivity such as industrial use, each mechanism is designed to wait in the state at the start of sewing so that sewing is started immediately by the sewing start operation of the operator. Therefore, when sewing the first stitch after setting the lower limit position of the intermittent presser to the same position as the upper surface of the needle plate at the start of sewing, the intermittent presser stands by at the position where the lower limit position is in contact with the upper surface of the needle plate. Become. If the operator performs the thread winding operation at this time, the thread winding process rotates only the sewing machine main shaft regardless of the sewing operation, and therefore the intermittent presser remains in the position in contact with the upper surface of the needle plate in conjunction with the rotation of the sewing machine main shaft. Move up and down. Therefore, there is a problem that noise is generated because the intermittent presser keeps colliding with the needle plate during the winding process.

  The object of the present invention is to prevent the intermittent presser from colliding with the needle plate during the thread winding process when the first stitch is sewn after the intermittent presser is set at the same position as the upper surface of the needle plate at the start of sewing. It is an object of the present invention to provide a sewing machine that can prevent noise generated by a collision between a presser foot and a needle plate.

  The sewing machine according to claim 1 is an intermittent presser that moves up and down in conjunction with the vertical movement of the needle bar and presses the work cloth on the needle plate from above, and an intermittent presser position change mechanism that can change the vertical movement position of the intermittent presser. And a thread winding mechanism that winds the lower thread around the bobbin in conjunction with the rotation of the sewing machine main shaft, an instruction means for instructing lower thread winding to wind the lower thread around the bobbin by the thread winding mechanism, and the instruction Detecting means for detecting the lower thread winding instruction by means, and when the detecting means detects the lower thread winding instruction by the indicating means, the intermittent presser moves up and down to a position where it does not contact the needle plate. A bobbin thread winding control means for rotating the sewing machine main shaft after controlling the intermittent presser position changing mechanism so as to change the vertical movement position of the intermittent presser is provided.

  In this sewing machine, when the detection means detects the lower thread winding instruction by the instruction means, the lower thread winding control means changes the vertical movement position of the intermittent presser to a position where it does not contact the needle plate even if the intermittent presser moves up and down. The intermittent presser position changing mechanism is controlled. Next, the bobbin winding control means rotationally drives the sewing machine main shaft and starts the bobbin winding process. The intermittent presser moves up and down in conjunction with the rotation of the sewing machine main shaft during the bobbin winding process. However, even if the intermittent presser moves up and down, the intermittent presser does not come into contact with the needle plate, so the intermittent presser does not collide with the needle plate.

  The sewing machine according to claim 2 is the sewing machine according to claim 1, wherein: the stop instruction means for instructing to stop the lower bobbin winding by the bobbin winding mechanism; and the stop detection means for detecting an instruction to stop the lower bobbin winding by the stop instruction means. The bobbin thread winding control means presets the vertical movement position of the intermittent presser after stopping the rotational drive of the sewing machine spindle when the stop detecting means detects the instruction to stop the bobbin thread winding. The intermittent presser position changing mechanism is controlled so as to change to a position.

  According to a third aspect of the present invention, in the invention of the first or second aspect, an intermittent presser position input means for inputting the vertical movement position of the intermittent presser is provided.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the vertical movement position is set at a lower limit position of a vertical movement range in which the intermittent presser moves up and down.

  According to the first aspect of the present invention, when the detection means detects the bobbin winding instruction by the instruction means, the vertical movement position of the intermittent presser is changed to a position where it does not contact the needle plate even if the intermittent presser moves up and down. After controlling the intermittent presser position changing mechanism, it is equipped with a lower thread winding control means that rotationally drives the sewing machine main shaft, so even if the intermittent presser moves up and down in conjunction with the rotation of the sewing machine main shaft during bobbin winding, the intermittent presser Do not collide with. Therefore, even if the bobbin winding process is performed when sewing the first stitch after setting the intermittent presser to the same position as the upper surface of the needle plate at the start of sewing, the noise generated by the collision between the intermittent presser and the needle plate is reduced. Can be prevented. In this case, since the vertical movement position of the intermittent presser can be automatically changed, the convenience of the sewing machine is improved.

  According to the invention of claim 2, the bobbin winding control means presets the vertical movement position of the intermittent presser after stopping the rotational driving of the sewing machine spindle when the stop detecting means detects the instruction to stop the bobbin winding. Since the intermittent presser position change mechanism is controlled to change to the position, when the first stitch is sewn after the thread winding process, the upper thread is pinched between the work cloth and the intermittent presser so that the thread at the start of sewing is removed. Can be prevented.

  According to the invention of claim 3, since the intermittent presser position input means for inputting the vertical movement position of the intermittent presser is provided, the vertical presser movement of the intermittent presser is based on the vertical presser position of the intermittent presser input by the intermittent presser position input means. The position can be changed. Therefore, even when the sewing data does not include intermittent presser data, the intermittent presser can be automatically changed to the same position as the upper surface of the needle plate when sewing the first stitch.

  According to the invention of claim 4, since the vertical movement position is set at the lower limit position of the vertical movement range in which the intermittent presser moves up and down, the intermittent presser is intermittently moved to a position where it does not come into contact with the needle plate even if the intermittent presser moves up and down. The presser can be easily and reliably changed.

  Hereinafter, the best mode for carrying out the present invention will be described.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the sewing machine 1 includes a bed portion 2, a pedestal portion 3 erected on the rear end portion of the bed portion 2 (upper left in FIG. 1), and the pedestal portion. 3 is provided with an arm portion 4 extending forward from the upper end of 3. A main shaft 5 is arranged in the front-rear direction inside the arm portion 4. The sewing machine motor 72 (see FIG. 10) drives the main shaft 5 to rotate. As shown in FIGS. 1 and 2, a presser bar 7 and a needle bar 8 (omitted in FIG. 1) are provided at the front end of the arm part 4. A sewing needle 9 is detachably attached to the lower end of the needle bar 8 protruding downward from the arm portion 4. An intermittent presser 6 having a cylindrical cloth presser portion 6 a is attached to the lower end of the presser bar 7 protruding downward from the arm portion 4. The intermittent presser 6 moves up and down in conjunction with the vertical movement of the needle bar 8 and presses the work cloth W from above.

  The intermittent presser vertical drive device 10 will be described with reference to FIGS. The intermittent presser vertical drive device 10 includes a swing mechanism 11, an intermittent presser vertical movement mechanism 12, and an intermittent presser position change mechanism 13. The swing mechanism 11 swings the first lever 24 in response to the rotational driving force of the main shaft 5. The intermittent presser vertical movement mechanism 12 is connected to the output end portion at the tip of the first lever 24 to move the intermittent presser 6 up and down. The intermittent presser position changing mechanism 13 changes the position (vertical movement position) of the range in which the intermittent presser 6 by the intermittent presser vertical movement mechanism 12 moves up and down.

  As shown in FIG. 6, the swing mechanism 11 includes an eccentric cam 20, an annular member 21 with an arm, a rotating shaft 22, and a lever member 23. The eccentric cam 20 is attached in the vicinity of the front end portion of the main shaft 5. The annular member 21 with an arm has an annular portion 21b that is externally fitted to the eccentric cam 20, and an arm portion 21a that protrudes from the outer periphery of the annular portion 21b.

  The rotary shaft 22 is rotatably supported on the machine frame F (see FIG. 1) in a front-rear direction parallel to the main shaft 5 at a position higher than the annular member 21 with arm. The rear end portion of the rotating shaft 22 is fixed to the upper end portion of the lever member 23. The upper end portion of the first lever 24 is fixed to the front end portion of the rotating shaft 22.

  As shown in FIG. 6, the lever member 23 has an arc hole 23 a having a predetermined width and having an arc shape with a radius R around the center of the eccentric cam 20 (which coincides with the axis of the main shaft 5). Is formed. A sliding pin 25 fixed to the left end of the arm portion 21a protruding leftward from the annular member 21 with arm is rotatably connected to the arc hole 23a. The connecting position of the arm portion 21a can be switched to an arbitrary position by changing the position of the sliding pin 25 within the length range of the arc hole 23a.

When the sewing operation is started, the main shaft 5 is rotationally driven in a predetermined rotational direction (clockwise as viewed from the front), and the eccentric cam 20 is rotationally driven based on the rotational driving of the main shaft 5. Based on the rotation of the eccentric cam 20, the annular member 21 with the arm reciprocates in the left-right direction by the amount of the eccentric cam 20.
Therefore, the lever member 23 connected to the arm portion 21a via the slide pin 25 swings around the rotation shaft 22 (see the arrow in FIG. 6). The swing of the lever member 23 is transmitted to the first lever 24 connected to the rotating shaft 22, and the first lever 24 also swings (see FIG. 7). The swing angle of the lever member 23 and the first lever 24 can be adjusted by moving the sliding pin 25 in the arc hole 23 a provided in the lever member 23.

  The intermittent presser vertical movement mechanism 12 will be described. As shown in FIGS. 3, 4, and 7, the intermittent presser vertical movement mechanism 12 includes a first link 30, a second link 31, and a third link 32. The first link 30 is disposed sideways. The left end portion of the first link 30 is connected to the lower portion of the first lever 24.

  The second link 31 includes a vertical link portion 31a and a horizontal link portion 31b and is integrally formed in an L shape in a front view. The upper end portion of the vertical link portion 31 a is rotatably connected to the right end portion of the first link 30. The left end portion of the horizontal link portion 31b is connected to the upper end portion of the vertically connecting link 33. The presser bar 7 is fixed to the lower end portion of the connecting link 33 through a presser bar holder 34. The presser bar holder 34 is fixed to the middle part of the presser bar 7 in the vertical direction. An intermittent presser 6 is detachably fixed to the lower end of the presser bar 7.

  As shown in FIG. 3, the sewing needle 9 moves up and down through the center portion of the presser portion 6a. Therefore, as shown in FIG. 2, the upper thread 15 extending from the eye hole of the sewing needle 9 also passes through the inside of the presser portion 6a.

  The third link 32 is disposed so as to overlap the front portion of the horizontal link portion 31 b of the second link 31. A right end portion of the third link 32 is connected to a connecting portion of the vertical link portion 31 a and the horizontal link portion 31 b of the second link 31. The support shaft 32 a at the left end of the third link 32 is supported by a support portion (not shown) provided on the machine frame F.

  As shown in FIG. 5, the third link 32 has a spring receiving portion 32 a on the rear side of the second link 31. The spring receiving portion 32 a is always biased downward based on the spring force of the compression coil spring 35 that is externally mounted on the presser bar 7. The inclination angle of the third link 32 with respect to the horizontal direction can be changed based on the operation of the intermittent presser position changing mechanism 13 described later.

  The first, second and third links 30 to 32 become parallel links when the needle bar 8 is at a sewing stop position slightly lowered from the uppermost position, for example. At this time, as shown in FIGS. 7 and 8, the connecting point between the first lever 24 and the first link 30 is P1, the connecting point between the first link 30 and the second link 31 is P2, and the second link 31 and the third link 31 are connected. If the connection point of the link 32 is P3, and the connection point of the third link 32 and the machine frame F is P4, the side P1-P2 and the side P4-P3 are parallel, and the side P2-P3 and the side P1-P4 are Become parallel.

  When the sewing machine motor 72 rotates, the main shaft 5 is driven to rotate. When the main shaft 5 is driven to rotate, the first lever 24 swings as described above, and the swing of the first lever 24 is transmitted to the second link 31 via the first link 30. As shown by the arrow in FIG. 7, the second link 31 swings about the connection point P3 with the third link 32 as the rotation center, so that the left end portion of the horizontal link portion 31b of the second link 31 moves up and down. . The presser bar 7 and the intermittent presser 6 that are connected to the left end of the horizontal link part 31b via the connecting link 33 and the presser bar holder 34 move up and down. Therefore, the intermittent presser 6 moves up and down within a predetermined vertical movement range in conjunction with the vertical movement of the needle bar 8. That is, the first link 30 converts the rotational drive of the main shaft 5 into the swing of the first lever 24 and transmits it to the second link 31. The second link 31 transmits the swing converted by the first link 30 to the intermittent presser 6 to move the intermittent presser 6 up and down.

  The intermittent presser position changing mechanism 13 that changes the vertical movement position of the intermittent presser 6 will be described. As shown in FIG. 1, a drive unit case 40 that houses a drive system is provided in the pedestal 3. As shown in FIG. 3, the drive unit case 40 rotatably supports the cam shaft 41 to which the cam body 42 is fixed. The intermittent presser pulse motor 43 (see FIG. 1) is attached to the outside of the drive unit case 40. The intermittent presser pulse motor 43 rotationally drives the cam shaft 41 via a gear mechanism (not shown).

  The intermittent presser pulse motor 43 can change the rotational position with high accuracy in accordance with the number of drive pulses. The cam surface of the cam body 42 is set so that the intermittent presser 6 becomes higher in proportion to the number of drive pulses for driving the intermittent presser pulse motor 43.

  A substantially L-shaped swing lever 45 is supported in the drive unit case 40 through a support shaft 44 above the cam shaft 41 in a side view. The lower end portion of the swing lever 45 rotatably supports a driven wheel 46 that contacts the cam body 42 from the outside. The upper end portion of the swing lever 45 connects the rear end portion of the connecting rod 47 extending in the front-rear direction. As shown in FIG. 1, the connecting rod 47 extends forward inside the arm portion 4. The rear end portion of the support lever 48 that is rotatably supported by the machine frame F is connected to the front end portion of the connecting rod 47. As shown in FIG. 5, the front end portion 48 a of the support lever 48 extending forwardly contacts and supports the spring receiving portion 32 a of the third link 32 from below.

  When the cam shaft 41 and the cam body 42 are driven to rotate forward by a predetermined angle (clockwise in FIG. 3) based on the driving of the intermittent presser pulse motor 43, the connecting rod 47 moves rearward and the support lever 48 moves clockwise. Rotate around (in FIG. 5). Therefore, the front end portion 48 a of the support lever 48 rises, and the third link 32 is lifted upward against the spring force of the compression coil spring 35. FIG. 7 shows a state where the third link 32 is lifted upward, and the state is switched from the right lowering posture (shown in FIG. 8) to the right rising posture (shown in FIG. 7). In the state shown in FIG. 7, the connecting point P3, which is the center of rotation, rises, so that the position of the intermittent presser 6 increases.

  The intermittent presser 6 moves up and down the needle bar 8 in the vertical movement range indicated by an arrow with the position of the intermittent presser 6 shown by the solid line in FIG. 7 as the upper limit position and the position of the intermittent presser 6 shown by the two-dot chain line as the lower limit position. Moves up and down in conjunction. The position of the vertical movement range can be changed by the intermittent presser position changing mechanism 13.

  When the camshaft 41 and the cam body 42 are reversely rotated by a predetermined angle based on the driving of the intermittent presser pulse motor 43, the connecting rod 47 moves forward and the support lever 48 rotates counterclockwise (in FIG. 5). To turn. The front end portion 48 a of the support lever 48 is lowered, and the third link 32 is pushed downward based on the spring force of the compression coil spring 35.

  FIG. 8 shows a state in which the third link 32 is pushed downward to switch to the right lowering posture. At this time, since the connection point P3 which is the rotation center is lowered, the intermittent presser 6 is pushed down, and the position of the intermittent presser 6 is lowered. As described above, the intermittent presser position changing mechanism 13 can set the lower limit position of the intermittent presser 6 to the same position as the upper surface of the needle plate.

  As described above, when the position of the intermittent presser 6 is the position shown in FIG. 7, the intermittent presser 6 moves up and down at a position that does not contact the upper surface of the needle plate 2 a in synchronization with the vertical movement of the sewing needle 9. Based on the adjustment of the rotation amount of the intermittent presser pulse motor 43, the position of the intermittent presser 6 in the vertical movement range (vertical movement position) can be set to an arbitrary position from the upper surface of the needle plate 2a. In the present embodiment, the lower limit position of the vertical movement range can be set to an arbitrary position of 0 to 10 mm above the upper surface of the needle plate 2a. The lower limit position of the vertical movement range of the intermittent presser 6 is set to a position 5 mm above the upper surface of the needle plate 2a as a position where the intermittent presser 6 does not come into contact with the needle plate 2a even if the intermittent presser 6 moves up and down at the start of the bobbin winding process.

Next, the bobbin winding mechanism 50 will be described.
As shown in FIG. 9, a thread winding mechanism 50 that winds the lower thread 51 around the bobbin 52 is provided on the upper portion of the arm portion 4. The pulley 5 a is provided on the main shaft 5. In the bobbin winding mechanism 50, the tip protrudes from the machine frame F of the arm portion 4, and a bobbin winding shaft 53 on which the bobbin 52 can be mounted is formed integrally with the bobbin winder 54. A bobbin bearing 55 that is displaceable in the front-rear direction (left-right direction in FIG. 9) supports the bobbin shaft 53. The bobbin bearing 55 is movable between a rotation position where the bobbin wheel 54 abuts on the pulley 5a and a retracted position where the bobbin wheel 54 does not abut on the pulley 5a. The bobbin winder 54 abuts on the pulley 5 a and transmits the rotation of the pulley 5 a to the bobbin shaft 53. The peripheral edge of the spool 54 is covered with a rubber ring 54a.

  A bobbin presser 57 is provided in the vicinity of the portion of the spool 4 that protrudes from the machine frame F of the arm portion 4. The bobbin presser 57 is fixed to a bobbin presser shaft 56 that is rotatably inserted into the machine frame F of the arm 4 by an adjusting screw 56a. The adjustment screw 56a is for adjusting the attachment position of the bobbin presser 57 to the bobbin presser shaft 56. The bobbin presser 57 comes into contact with the lower thread 51 wound around the bobbin 52. The bobbin presser 57 rotates around the bobbin presser shaft 56 according to the bobbin winding amount of the bobbin 52.

  The bobbin presser 57 is provided with a hole 57a for loosely fitting the flange 52a of the bobbin 52, so that the operation part of the bobbin presser 57 is widened. The pincushion bearing 55 is connected to the bobbin presser shaft 56 via a link mechanism 58. The pincushion bearing 55 moves between the rotational position and the retracted position by operating the bobbin presser 57.

  The operator attaches the bobbin 52 to the bobbin winding shaft 53 and then operates the bobbin presser 47 to move the bobbin bearing 55 to a rotational position where it abuts against the pulley 5a. After that, the bobbin winding process is executed by turning on the start pedal 70 (see FIG. 10) with the bobbin winding key 67 (see FIG. 10) turned on. The main shaft 5 rotates together with the pulley 5a based on the drive of the sewing machine motor 72, and the bobbin shaft 55 and the bobbin 52 rotate along with the rotation of the pulley 5a. Therefore, the lower thread 51 can be wound around the bobbin 52. When the activation pedal 70 is turned off, the driving of the sewing machine motor 72 is stopped and the thread winding process is terminated.

Next, the electrical configuration of the control system of the sewing machine 1 will be described.
As shown in FIG. 10, the control device 60 includes a microcomputer including a CPU 62, a ROM 63, and a RAM 64, an input interface 61 and an output interface 65 connected to the microcomputer via a data bus or the like.

  The input interface 61 includes an operation panel 66 having a thread winding key 67, a programmer 68, a presser pedal 69 for outputting a position setting command for the intermittent presser 6 by a stepping operation by an operator, and a sewing start command by a stepping operation by the operator. Is connected to an activation pedal 70 or the like. A sewing machine motor 72, an XY feed pulse motor 74, and an intermittent presser pulse motor 43 are connected to the output interface 65 via drive circuits 71, 73, and 75, respectively.

  The operation panel 66 is configured to be able to input data for instructing the lower limit position of the intermittent presser 6, a default value for instructing the position of the intermittent presser 6 set at the start of the thread winding process, and the like. The bobbin winding key 67 outputs a bobbin winding command by an operator's pressing operation. The start pedal 70 outputs a bobbin winding stop command by an operator's stepping operation during the bobbin winding process. The operation panel 66 corresponds to intermittent presser position input means, the thread winding key 67 corresponds to instruction means, and the activation pedal 70 corresponds to stop instruction means.

  The programmer 68 is a device that creates sewing data for forming stitches on the work cloth W. By operating the numeric keys and function keys provided in the programmer 68, sewing data of a desired pattern can be created. The sewing data created by the programmer 68 is stored in the RAM 64. The sewing data may be stored in advance in an external storage device such as the ROM 63 or a memory card. In this case, the sewing data read from the ROM 63 or the like is stored in the RAM 64 and then the sewing process is executed.

  The ROM 63 includes a control program for sewing control including drive control of various drive mechanisms, pattern selection control for selecting various patterns, and various display controls, a control program for intermittent presser position control (see FIG. 12), and intermittent A presser lowering process control program (see FIG. 13), a thread winding process control program (see FIG. 14), a sewing process control program (see FIG. 15), and the like are stored in advance.

  The RAM 64 stores data indicating the lower limit position of the intermittent presser 6 input via the operation panel 66 and a default value input via the operation panel 66. As shown in FIG. 11, the RAM 64 includes a plurality of stitch data for instructing needle drop points for forming stitches on the work cloth created by the programmer 68, and intermittent presser data for instructing the lower limit position of the intermittent presser 6. Sewing data including is stored. The RAM 64 corresponds to default value storage means and sewing data storage means.

Next, sewing data for forming stitches on the work cloth will be described.
As shown in FIG. 11, the sewing data is composed of a data order indicating the order of reading, and data contents including the type of sewing data, various settings, instruction values, and the like. In this embodiment, the sewing data consists of a total of 13 pieces of data in the order of data 0 to 12. The sewing data includes stitch data, intermittent presser data, and end data.

  The stitch data is designated by relative coordinates composed of the X direction (front-rear direction in FIG. 1) and the Y direction (left-right direction in FIG. 1). The intermittent presser data sets the lower limit position of the intermittent presser 6. The end data instructs the end of the sewing process. The sewing data may include data indicating various parameters necessary for sewing, such as temporary stop data, thread color data indicating the thread color, and sewing speed data indicating the vertical movement speed of the needle bar 8. .

Next, the intermittent presser position control executed by the control device 60 based on the sewing data of FIG. 11 and the flowcharts of FIGS. 12 to 15 will be described. In the figure, Si (i = 1, 2,...) Indicates each step.
First, when the operator turns on the sewing machine 1 and selects sewing data, the XY feed pulse motor 74 is driven to move the needle position to the sewing start position (S1). A data order counter N for sequentially reading out the sewing data is set to 0 (S2). Next, when the operator turns on the presser pedal 69 (S3; Yes), it is determined whether or not the intermittent presser 6 is in the standby position. The standby position is a position of the intermittent presser 6 that does not hinder the operator from placing the work cloth on the needle plate 2a, and is a position higher than the height at the time of sewing.

When the intermittent presser 6 is in the standby position (S4; Yes), the intermittent presser lowering process is executed (S6).
When the intermittent presser lowering process is executed, the value of the data rank counter N is copied to the check counter M (S20). If the data content indicated by the check counter M is intermittent presser data (S21; Yes), the intermittent presser pulse motor 43 is driven to lower the intermittent presser 6 to the position indicated by the intermittent presser data (S25), and then to S7. Transition. Here, since the data order counter N and the check counter M are 0, the position of the intermittent presser 6 is changed to 0 in the sewing data of FIG. This position represents the lower limit position, and the position of 0 is the same position (contact) with the upper surface of the needle plate 2a.

If the position of the intermittent presser 6 of the first stitch is not indicated in the sewing data, it is determined that the data order indicated by the check counter M is stitch data (S21; No, S22; Yes), and the operator operates After the intermittent presser 6 is lowered to the lower limit position set in advance via the panel 66 (S24), the process proceeds to S7. For example, when the data contents of the data order indicated by the check counter M, such as thread color data and sewing speed data, are neither intermittent presser data nor stitch data (S21; No, S22; No), the check counter M is set to 1. After incrementing (S23), the process returns to S21.
If the intermittent presser 6 has already been lowered and is not at the standby position (S4; No), the intermittent presser 6 is raised to the standby position (S5), and then the process proceeds to S7.

  In S7, the presser pedal 69 is in an OFF waiting state. When the operator turns the presser pedal 69 OFF (S7; Yes, S3; No), it is next determined whether or not the activation pedal 70 is turned ON (S8). ). When the operator turns on the activation pedal 70 and also turns on the thread winding key 67 (S8; Yes, S9; Yes), the thread winding process is executed (S10).

  When the thread winding process is executed, first, the default value stored in the RAM 64 is read and the intermittent presser 6 is raised to the position indicated by the default value (S30). In this embodiment, the default value is 5, and the intermittent presser 6 is positioned 5 mm above the upper surface of the needle plate 2a. Next, the sewing machine motor 72 is started to execute the bobbin winding process by the bobbin winding mechanism 50. When the bobbin winding process is executed, the activation pedal 70 is in an OFF waiting state. When the operator turns off the activation pedal 70 (S32; Yes), the drive of the sewing machine motor 72 is stopped (S33), and then the intermittent presser 6 is lowered to a preset position as in the case of S24 and S25. (S34) and return to S3.

  Next, when the operator turns on the activation pedal 70 (S8; Yes), if the thread winding key 67 is turned off (S9; No), the sewing process is executed (S11). When the sewing process is executed, the sewing machine motor 72 is first activated (S40), and then the data of the data rank N is read (S41). It is determined whether or not the data order N is stitch data. When the data is stitch data (S42; Yes), when the feed start timing is reached (S43; Yes), the XY feed pulse motor 74 is driven to perform sewing. (S44). Next, after the data rank N is incremented by 1 (S47), the process returns to S41.

  If the data rank N is intermittent presser data (S42; No, S45; Yes), the position of the intermittent presser 6 is changed based on the intermittent presser data (S46). Next, after the data rank N is incremented by 1 (S47), the process returns to S41. In FIG. 11, when the operation of data rank 0 is performed, since the intermittent presser lowering process is executed in S6, the intermittent presser 6 is in contact with the needle plate 2a based on the intermittent presser data. Therefore, the intermittent presser 6 maintains its position. In FIG. 11, when the operation of the data rank 2 is performed, the intermittent presser 6 is changed to a position 3 mm above the needle plate 2a based on the intermittent presser data.

  If the data order N is not intermittent presser data in S45, that is, if the operation of data order 12 is performed, that is, if it is end data (S45; No), the drive of the sewing machine motor 72 is stopped (S48). . Next, after raising the intermittent presser 6 to the standby position (S12), the process returns to S1. The CPU 62 that executes the process of S9 in the flowchart shown in FIG. The CPU 62 that executes the processes of S30 to S34 in the flowchart shown in FIG. 14 corresponds to the bobbin thread winding control means. The CPU 62 that executes the process of S32 in the flowchart shown in FIG. 14 corresponds to the stop detection unit.

Next, functions and effects of the sewing machine 1 described above will be described.
When an instruction for thread winding by the thread winding key 67 is detected, the intermittent presser position changing mechanism 13 is controlled so as to change the vertical movement position of the intermittent presser 6 to a position where it does not contact the needle plate 2a even if the intermittent presser 6 moves up and down. After that, since the main shaft 5 is driven to rotate, even if the intermittent presser 6 moves up and down in conjunction with the rotation of the main shaft 5 during the yarn winding process, the intermittent presser 6 does not collide with the needle plate 2a. Therefore, even if the bobbin winding process is executed when sewing the first stitch after setting the intermittent presser 6 at the same position as the upper surface of the needle plate 2a at the start of sewing, the intermittent presser 6 and the needle plate 2a collide with each other. The generated noise can be prevented. In this case, since the vertical movement position of the intermittent presser 6 can be automatically changed, the usability of the sewing machine 1 is improved.

  When an instruction to stop the bobbin winding is detected, the intermittent presser position is set so that the vertical movement position of the intermittent presser 6 is changed to the same position as the preset upper surface of the needle plate 2a after the spindle 5 is stopped from rotating. Since the change mechanism 13 is controlled, when the first stitch is sewn after the thread winding process, the upper thread 15 is sandwiched between the work cloth W and the intermittent presser 6 to prevent the thread from coming off at the start of sewing. .

  Since the operation panel 66 for inputting the vertical movement position of the intermittent presser 6 is provided, the vertical movement position of the intermittent presser 6 can be changed based on the vertical movement position of the intermittent presser 6 input by the operation panel 66. Therefore, even when the sewing data does not include intermittent presser data, the intermittent presser 6 can be automatically changed to the same position as the upper surface of the needle plate 2a when sewing the first stitch. Since the vertical movement position is set at the lower limit position of the vertical movement range in which the intermittent presser 6 moves up and down, the intermittent presser 6 can be easily and reliably positioned so that it does not come into contact with the needle plate 2a even if the intermittent presser 6 moves up and down during the bobbin winding process. Can be changed.

Next, a modified example in which the above embodiment is partially modified will be described.
1] Intermittent presser position control can also be applied to a sewing machine having an outer presser mechanism that moves an outer presser having a substantially rectangular planar shape up and down. In this case, when the intermittent presser lowering process is executed in FIG. 13, the outer presser is first lowered to a position where the work cloth W is pressed, and then the processes after S20 are sequentially performed. In S5, the intermittent presser 6 and the outer presser are raised to the standby position.
2] In the present embodiment, the vertical movement position of the intermittent presser 6 is defined by the lower limit position of the vertical movement range, but may be defined by the upper limit position. Moreover, you may prescribe | regulate in the center position of the up-and-down movement range.

1 is a perspective view of a sewing machine according to an embodiment of the present invention. It is a front view of a sewing machine at the time of sewing standby. It is a perspective view of an intermittent presser vertical movement drive device. It is a perspective view of the principal part of an intermittent presser vertical movement drive device. It is a right view of an intermittent presser vertical movement drive device. It is a front view of a rocking mechanism. It is a front view of an intermittent presser vertical movement mechanism when an intermittent presser is in an upper position. It is a front view of an intermittent presser up-and-down movement mechanism when an intermittent presser is in a lower position. It is a side view of a bobbin winding mechanism. It is a block diagram which shows the control system of a sewing machine. It is explanatory drawing for demonstrating sewing data. It is a flowchart of an intermittent presser position control program. It is a flowchart of the control program of an intermittent presser lowering process. It is a flowchart of the control program of a thread winding process. It is a flowchart of the control program of a sewing process.

Explanation of symbols

1 sewing machine 5 spindle 6 intermittent presser 8 needle bar 13 intermittent presser position changing mechanism 50 bobbin winding mechanism 51 lower thread 52 bobbin 62 CPU
64 RAM
66 Operation panel 67 Bobbin key 70 Start pedal W Work cloth

Claims (4)

Intermittent presser that moves up and down in conjunction with the vertical movement of the needle bar and presses the work cloth on the needle plate from above, an intermittent presser position change mechanism that can change the vertical movement position of the intermittent presser, and rotation of the sewing machine spindle In a sewing machine having a bobbin winding mechanism that winds a bobbin thread around a bobbin
Instruction means for instructing bobbin winding by which the bobbin is wound around the bobbin by the bobbin winding mechanism;
Detecting means for detecting the lower thread winding instruction by the instruction means;
When the detection means detects the lower thread winding instruction by the instruction means, the intermittent presser is moved so as to change the vertical movement position of the intermittent presser to a position where it does not contact the needle plate even if the intermittent presser moves up and down. A sewing machine comprising: a bobbin winding control means for rotating the sewing machine main shaft after controlling the position changing mechanism. Stop instruction means for instructing to stop the lower bobbin winding by the bobbin winding mechanism;
A stop detecting means for detecting an instruction to stop the lower bobbin winding by the stop instructing means,
The lower bobbin winding control means changes the vertical movement position of the intermittent presser to a preset position after stopping the rotational driving of the sewing machine spindle when the stop detection means detects an instruction to stop the lower bobbin winding. The sewing machine according to claim 1, wherein the intermittent presser position changing mechanism is controlled as described above.   The sewing machine according to claim 1 or 2, further comprising intermittent presser position input means for inputting the vertical movement position of the intermittent presser.   The sewing machine according to any one of claims 1 to 3, wherein the vertical movement position is set at a lower limit position of a vertical movement range in which the intermittent presser moves up and down.

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