JP2019063124A - Sewing machine and control method of sewing machine - Google Patents

Abstract

To provide a sewing machine in which an inner presser foot comes into contact with a fabric stably even when a swing state changes, and to provide a control method of a sewing machine.SOLUTION: A sewing machine includes a needle bar, a fabric holding body and an inner presser foot. The needle bar mounts a sewing needle at a lower end. The fabric holding body holds a fabric. The fabric holding body moves in a non-penetration period in which the sewing needle is above the fabric, and stops in the penetration period in which the sewing needle penetrates the fabric. The inner presser foot moves vertically between a contact position to come to contact with the fabric and a retreat position to retreat above the contact position. The sewing machine executes normal mode sewing processing (S29) and special mode sewing processing (S27). In the normal mode sewing processing, the inner presser foot moves to the contact position in the period other than a feeding period in which the fabric holding body moves, and moves to the retreat position after the completion of the penetration period and before the start of the feeding period. In the special mode sewing processing, the inner presser food is located in the contact position while specific sewing which is sewing of a predetermined number of stitches is being executed, and moves to the retreat position after the completion of the penetration period of the final needle number of the specific sewing and before the start of the feeding period.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a sewing machine and a control method of the sewing machine.

  A sewing machine is known that is provided with an intermediate presser that presses the cloth intermittently during sewing. The sewing machine disclosed in Patent Document 1 includes a work cloth holder, a sewing machine main shaft, a sewing machine motor, a needle bar, a presser bar, a cloth presser foot (middle presser), a swing cam, and a cam follower. The work cloth holder holds the work cloth and moves in the X direction and the Y direction. The sewing machine spindle is rotated by the drive of the sewing machine motor. The needle bar attaches a sewing needle at the lower end and moves up and down by the rotational force of the sewing machine main shaft. The presser bar extends vertically in parallel with the needle bar, and mounts the presser foot at the lower end. The swing cam is swingably supported inside the sewing machine and slidably engages with the needle bar. The swing cam swings as the needle bar moves up and down. The cam follower is supported by the presser bar and slidably engaged with the swing cam. When the cam follower slides on the swinging cam, the presser bar vertically moves with the presser foot. The presser foot intermittently presses the work cloth. As the sewing machine changes the sliding range of the cam follower relative to the swing cam, the range in which the presser foot moves up and down changes. When the thickness of the work cloth, which is an example of the sewing state, increases, the range in which the presser foot moves up and down changes to the upper side.

Japanese Examined Patent Publication 7-44983

  However, in the above-described sewing machine, since the presser foot moves up and down by the rotational force of the sewing machine main shaft, the time for the presser foot to press the work cloth is extremely short. Therefore, even if the sewing machine changes the range in which the presser foot vertically moves in accordance with the sewing state, the presser foot may not be able to stably contact the work cloth.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sewing machine and a control method of the sewing machine in which the intermediate presser stably contacts the cloth even when the sewing state changes.

  The sewing machine according to the first aspect of the present invention is capable of holding a cloth, capable of moving up and down above the cloth held in the horizontal direction, and the cloth held by the cloth holder, and mounting a sewing needle at the lower end A sewing machine including a sewing mechanism for sewing the cloth with the sewing needle, and a drive unit for driving the cloth holder and the sewing mechanism, the sewing machine extending in the vertical direction in parallel with the needle bar; An intermediate presser bar capable of moving up and down above the cloth; an intermediate presser drive unit for moving the intermediate presser bar up and down; an intermediate presser mounted on the lower end of the intermediate presser bar; The cloth holder is moved within a non-penetration period in which the sewing needle is above the cloth, and the cloth holder is stopped and the cloth is sewn during the penetration period while the sewing needle pierces the cloth. A sewing control unit, and the middle presser wheel when the sewing control unit sews the cloth A middle pressing control unit moving up and down between a contact position where the middle presser comes in contact with the cloth from above and a retracted position where it is retracted above the contact position; The cloth holder moves during the non-penetration period when the sewing control unit performs sewing on the cloth, and the intermediate press control unit is configured to move the cloth holder other than the feeding period. The intermediate presser is moved from the retracted position to the contact position, and the intermediate presser is moved to the contact position after the penetration period ends and before the feed period starts after the intermediate presser moves to the contact position. Placing the middle presser at the contact position while the first middle presser control unit moving from the second position to the retracted position and the specific sewing which is sewing of a predetermined number of stitches in which the sewing control unit makes two or more needles is executed; The end of the penetration period corresponding to the final stitch number of the specific sewing After that, and before the start of the feeding period, there is provided a second presser control unit that moves the presser to the retracted position, and one of the first presser control unit and the second presser control unit And drive controlling the above-mentioned middle presser drive part.

  According to the above configuration, the sewing machine moves the middle presser up and down by drive control by one of the first middle presser control unit and the second middle presser control unit according to the sewing state. The sewing machine can change the arrangement time at the contact position of the middle presser according to the sewing state. Therefore, a sewing machine is realized in which the middle presser stably contacts the cloth even if the sewing state changes.

  In the sewing machine, the specific sewing is the sewing of the predetermined number of stitches from the start of sewing, and the first middle press control unit controls the middle press drive after the second middle press control unit controls driving of the middle press drive unit. The presser may be driven and controlled. The intermediate presser can stably contact the cloth at the start of sewing.

  The sewing machine includes an input unit to which the setting of the predetermined number of stitches is input, and the second middle press control unit performs the sewing control on the specific sewing which is sewing of the predetermined number of stitches input to the input unit. The fabric may be placed in the contact position while the unit is performing. The operator can set the number of stitches for specific sewing. Therefore, the usability of the sewing machine is improved.

  The sewing machine includes an input unit to which the setting of the vertical position which is the contact position of the middle presser in the drive control by the second middle presser control unit is input, and the second middle presser control unit The middle presser drive unit may be drive-controlled so that the vertical position input to the second position is the contact position. Since the operator can set the vertical position of the contact position, the usability of the sewing machine is improved.

  In the sewing machine, the sewing control unit can change the feeding period, and the second middle pressing control unit changes the middle pressing from the contact position according to the feeding period changed by the sewing control unit. The timing of moving to the retracted position may be changed. Even when the sewing machine changes the feeding period of the cloth holder, the middle presser moved up and down by the second middle presser control portion can contact the cloth stably.

  The control method of the sewing machine according to the second aspect of the present invention is capable of holding the cloth, and capable of moving up and down above the cloth held by the cloth holder and the cloth holder that is moved in the horizontal direction. The sewing machine has a needle bar attached to the lower end, and extends vertically in parallel with the needle bar, a sewing mechanism for sewing the cloth with the sewing needle, a drive unit for driving the cloth holder and the sewing mechanism, A control method of a sewing machine, comprising: a middle presser bar capable of moving up and down above a cloth; a middle presser driving unit for moving the middle presser bar up and down; and a middle presser mounted on a lower end of the middle presser bar; The drive unit is driven and controlled, the sewing needle moves the cloth holder within a non-penetration period above the cloth, and the cloth holder is stopped during the penetration period during which the sewing needle pierces the cloth. A sewing control step of performing sewing on the cloth, and sewing on the cloth in the sewing control step When driving, the middle presser drive unit is drive-controlled to move the middle presser vertically between the contact position where it contacts the cloth from above and the retracted position where it is retracted above the contact position. A control step, wherein the cloth holder moves during the non-penetration period when sewing on the cloth in the sewing control step, and in the middle press control step, the cloth holder moves The intermediate presser is moved from the retracted position to the contact position during the period other than the feed period, and after the intermediate presser moves to the contact position, after the end of the penetration period and before the start of the feed period The first presser control step of moving the presser from the contact position to the retracted position, and the middle presser while executing a specific sewing that is sewing of a predetermined number of stitches having two or more needles in the sewing control step. Arranged at the contact position, And a second middle presser control step of moving the middle presser to the retracted position after the penetration period corresponding to the number of needles and before the start of the feed period, and the first middle presser control step and the second middle presser control step (2) Drive control of the above-mentioned presser driving unit is performed in any one of the two presser control steps. According to the second aspect, the same effect as the first aspect is exerted.

FIG. 1 is a perspective view of a sewing machine 1; Fig. 2 is a left side view of a sewing machine 1; FIG. The fragmentary sectional view in the arrow direction in the AA of FIG. 3 (middle pressing motor 23 illustration abbreviation | omission). The enlarged view of the area | region enclosed with the dashed-two dotted line W1 of FIG. The enlarged view of the area | region enclosed with the dashed-two dotted line W1 of FIG. The graph which shows middle presser-lifting up-and-down timing in normal mode. The graph which shows middle pressing-up / down timing in special mode. FIG. 2 is a diagram showing an electrical configuration of a sewing machine 1; 11 is a configuration diagram of middle presser information 95. FIG. Flow chart of the first main process. Flow chart of the sewing process of the special mode. The front view of the middle presser 21 in a contact position, and the front view of the sewing needle 20 in a top dead center (at the time of standard cloth 51 sewing). The front view of the middle presser 21 in a contact position, and the front view of the sewing needle 20 in a bottom dead center (at the time of standard cloth 51 sewing). The flowchart of sewing processing of normal mode. The front view of the middle presser 21 in a retracted position, and the sewing needle 20 in a top dead center (at the time of standard cloth 51 sewing). The front view of the middle presser 21 in a contact position, and the sewing needle 20 in a top dead center (at the time of thick cloth 52 sewing). The front view of the middle presser 21 in a retracted position, and the sewing needle 20 in a bottom dead center (at the time of special cloth 53 sewing).

  A sewing machine 1 according to an embodiment of the present invention will be described. In the following description, upper and lower, right and left, and front and back indicated by arrows in the drawings are used.

  The structure of the sewing machine 1 will be briefly described. As shown in FIGS. 1 to 3, the sewing machine 1 includes a bed 2, a pillar 3, an arm 4, a presser 9, a cloth feeding device 60, and a controller 30 (see FIG. 9). The bed unit 2 is provided on a sewing machine table, and includes a work table support unit 5 and a storage unit 6. The work platform support 5 projects forward from the front wall of the housing 6. The workbench support 5 includes a workbench 7 on the top surface. The work table 7 is provided with a needle plate 13 substantially at the center in plan view. The needle plate 13 has a needle hole 16 substantially at the center. The housing portion 6 has a substantially rectangular parallelepiped box shape whose upper side is open. The interior of the worktable support 5 and the interior of the housing 6 communicate with each other. A lower shaft extends in the front-rear direction in the housing 6 and the work table support 5. The front end of the lower shaft is connected to a hook inside the worktable support 5 and below the needle plate 13. The kettle accommodates a bobbin wound with a lower thread. The kettle rotates about the lower shaft.

  The pillar 3 is erected upward from the rear of the bed 2. The arm 4 extends forward from the top of the pillar 3. The arm 4 rotatably supports a main shaft extending in the front-rear direction. The main shaft is connected to a main motor 27 provided on the rear side inside the arm 4. The main shaft is connected to the lower shaft via a series extending in the vertical direction inside the pillar 3. Therefore, when the main motor 27 is driven, the hook and the spindle rotate in synchronization with each other. The sewing machine table includes an operation unit 99 (see FIG. 9). The operation unit 99 includes a display unit 98 and an input unit 97. The display unit 98 displays various information, and the input unit 97 receives input of various information.

  The front end of the arm 4 is a tip 8. The lower end of the tip 8 faces the upper surface of the needle plate 13. The tip portion 8 includes a sewing machine frame 14. The sewing machine frame 14 is internally provided with a guide groove and a through hole 48 (see FIG. 4). The guide groove is formed on the left side surface of the sewing machine frame 14. The guide groove extends vertically and opens rightward. The through hole 48 opens in the vertical direction. The distal end portion 8 supports the needle bar 19 so as to be vertically movable. The needle bar 19 is connected to the main shaft. The needle bar 19 extends vertically and protrudes downward from the tip 8. The needle bar 19 mounts the sewing needle 20 at its lower end. The sewing needle 20 has an eye 20A for holding an upper thread. When the needle bar 19 moves up and down by the rotation of the main shaft, the sewing needle 20 moves up and down and passes through the needle hole 16. The vertically moving sewing needle 20 cooperates with the hook to form a stitch on the cloth 50. Hereinafter, the lower shaft, the hook, the connecting rod, the main shaft, and the needle bar 19 will be collectively referred to as a sewing mechanism 15.

  The cloth feeding device 60 includes an X motor 41 (see FIG. 9), an X rail, an X moving plate (not shown), a Y rail, a Y moving plate (not shown), a cloth holder 70, a support portion 67, a shaft portion 68, A Y motor 42 (see FIG. 9) is provided. The X motor 41 is provided on the rear side inside the housing portion 6. The X rail extends in the X direction (left and right direction) inside the housing portion 6 and in front of the X motor 41. The X moving plate is movably coupled to the X rail so as to be laterally movable and coupled to the X motor 41. The X moving plate moves laterally along the X rail by the driving force of the X motor 41. The Y rail is fixed to the upper surface of the X moving plate and extends in the Y direction (longitudinal direction). The Y rail moves laterally with the X moving plate. The Y moving plate is movably connected to the Y rail back and forth. The cloth holder 70 is fixed to the upper surface of the Y moving plate. The cloth holder 70 moves in the left-right direction integrally with the X moving plate and the Y moving plate, and moves in the front-rear direction integrally with the Y moving plate. In other words, the cloth holder 70 is movable in the horizontal direction. The support portion 67 is connected to a rear portion of a pressing arm 65 described later of the cloth holder 70. The support portion 67 supports the cloth holder 70 so as to be movable laterally. The shaft portion 68 is a shaft member that extends rearward from the support portion 67 to the inside of the pillar 3 and can move back and forth. The Y motor 42 is provided inside the pillar 3 and connected to the shaft 68. When the shaft portion 68 moves back and forth by the driving force of the Y motor 42, the support portion 67, the cloth holder 70, and the Y moving plate move back and forth together.

  The cloth holder 70 includes a feed plate 77, a pressing arm 65, a pair of connecting portions 73, a pressing frame 11, and a pair of air cylinders 79. The feed plate 77 has a substantially rectangular shape in plan view, and extends forward from the upper surface of the Y moving plate. The feed plate 77 has a pinch frame 12 at its front end. The clip frame 12 is rectangular and frame-shaped in plan view. The clip frame 12 can support the cloth 50. The pressing arm 65 sandwiches and fixes the rear end of the feed plate 77 with the upper surface of the Y moving plate, extends upward from the rear end of the feed plate 77, and further bends and extends forward. A tip end portion 65A which is a front end portion of the pressing arm 65 is substantially rectangular in a front view. The pair of connecting portions 73 are aligned in the left-right direction, and supported by the tip portion 65A so as to be movable up and down. The pair of connecting portions 73 support the presser frame 11. The pressing frame 11 is substantially rectangular and frame-shaped in a plan view, and faces the sandwiching frame 12 in the vertical direction. A pair of air cylinders 79 are provided on the left and right portions of the presser arm 65, respectively. The pair of air cylinders 79 are connected to the pair of connecting portions 73, respectively. By driving the pair of air cylinders 79 to move the pair of connecting portions 73 up and down, the presser frame 11 separates from the cloth 50 in the holding position at which the cloth 50 supported by the clamp frame 12 is pressed from above. Move up and down between the separated position.

  The sewing machine 1 of the present embodiment can sew a cloth 50 having various thicknesses, and the nipping position of the pressing frame 11 changes in accordance with the thickness of the cloth 50. Hereinafter, the cloth 50 having a predetermined thickness is referred to as a standard cloth 51 (see FIG. 13), and the cloth 50 is referred to as a thick cloth 52 (see FIG. 17) than the standard cloth 51. The soft cloth 50 is referred to as a special cloth 53 (see FIG. 18).

  The configuration of the intermediate pressing device 9 will be described with reference to FIGS. 3 to 6. The middle pressing device 9 includes a rocking rod 31, a pin 34, a middle pressing rod 22, a middle pressing rod holder 26, a middle pressing 21, and a drive mechanism 28. The swinging rod 31 supports the tip end portion 8 so as to move up and down at a left and right position on the left side of the needle rod 19. The rocking rod 31 extends in the vertical direction. The upper portion of the swinging rod 31 enters the through hole 48 of the sewing machine frame 14, and the lower portion of the swinging rod 31 protrudes downward from the tip end portion 8. The swinging rod 31 has a receiving portion 39 and a pin hole. The receiving portion 39 extends in a direction away from the axis of the rocking rod 31. The receiving portion 39 is, for example, a bolt screwed to the swinging rod 31 and can change the fixed position with respect to the swinging rod 31 in the vertical direction. The pin hole is a circular hole penetrating perpendicularly to the lower portion of the rocking rod 31.

  The middle presser bar 22 has a substantially cylindrical shape extending in the vertical direction at a position coaxial with the swinging bar 31. The lower portion of the swinging rod 31 is inserted into a hole 35 which is a cylindrical hole of the middle pressing rod 22. The middle presser bar 22 is provided with an elongated hole 36 which is elongated in the vertical direction at each of the upper end front portion and the upper end rear portion. The pair of elongated holes 36 penetrate the middle presser bar 22 in the front-rear direction. The pair of elongated holes 36 oppose the pin holes in the front-rear direction. The vertical length of the long hole 36 is longer than the inner diameter of the pin hole, and the horizontal length of the long hole 36 is slightly longer than the inner diameter of the pin hole. The pin 34 has a cylindrical shape having an outer diameter substantially the same as the inner diameter of the pin hole, and is inserted into the pair of elongated holes 36 and fitted in the pin hole.

  The middle presser bar holder 26 is provided on the upper part of the middle presser bar 22. The presser bar holder 26 is provided with a through hole 47 which opens in the vertical direction. The middle presser bar holder 26 passes the upper end portion of the middle presser bar 22 through the through hole 47 and is fixed to the middle presser bar 22 with a screw 45. Therefore, the middle presser bar holder 26 moves up and down integrally with the middle presser bar 22. The left portion of the presser bar holder 26 is fitted in the guide groove of the sewing machine frame 14 so as to be vertically movable. The guide groove guides the up and down movement of the presser bar holder 26. The middle presser 21 is attached to the lower end of the middle presser bar 22. The middle presser 21 suppresses lifting of the cloth 50 when the sewing needle 20 is pulled upward. The middle presser 21 has a through hole 21A opened in the vertical direction. The through hole 21A has a circular shape in plan view coaxial with the needle bar 19, and can pass the sewing needle 20 moving up and down.

  The drive mechanism 28 is a mechanism that moves the middle presser bar 22 and the middle presser 21 integrally in the vertical direction. The drive mechanism 28 includes a presser motor 23, an arm 40, a link 33, a connecting member 32, and a biasing member 24. The middle pressing motor 23 is fixed to the upper end of the tip end portion 8. The intermediate presser motor 23 has an output shaft 49 projecting forward. The arm 40 protrudes leftward from the output shaft 49 as an example. The link 33 extends in the vertical direction on the front side of the center presser bar 22 and the swing bar 31. The upper end of the link 33 is rotatably connected to the left end of the arm 40. The lower end of the link 33 is on the front lower side of the middle presser bar holder 26. The connecting member 32 has a substantially rectangular parallelepiped shape. The connecting member 32 is connected to the pin 34 from the outer peripheral side of the middle presser bar 22, and is rotatably connected to the lower end of the link 33 via the threaded screw 43. In other words, the connecting member 32 is connected to the presser bar 22 and rotatably connected to the link 33. The connecting member 32 is provided with a through hole 46 opened in the vertical direction. The through hole 46 passes the presser bar 22 inward.

  The biasing member 24 is a coil spring passing the swinging rod 31 inside, and abuts on the receiving portion 39 of the swinging rod 31 and the upper end of the middle presser bar clamp 26. The presser bar holder 26 contacts the connecting member 32 by the biasing force of the biasing member 24. When an upward force acts on the middle presser 21, the middle presser bar 22 moves upward with the connecting member 32 against the biasing force of the biasing member 24 in the range of the pair of long holes 36 through which the pin 34 is inserted. Do. At this time, the presser bar holder 26 separates from the connecting member 32.

  The intermediate pressing motor 23 reciprocates the output shaft 49 in accordance with the vertical movement of the sewing needle 20 by the drive of the main motor 27. In the present embodiment, the output shaft 49 reciprocates in a range in which the connecting portion of the arm 40 with the link 33 is on the left with respect to the output shaft 49. The link 33 swings as the output shaft 49 reciprocates, whereby the connecting member 32 moves up and down. When the link 33 swings when the connecting member 32 abuts against the middle presser bar clamp 26, the connection member 32 moves up and down together with the middle presser bar 22 via the middle presser bar clamp 26. When the middle presser 21 is lowered, the middle presser bar holder 26 abuts on the connecting member 32 by the biasing force of the biasing member 24. The position of the pin 34 in the vertical direction is slightly below the upper end of the pair of elongated holes 36. At this time, the middle presser 21 is moved to the contact position (see FIGS. 13 and 17) which is the height position at which the cloth holder 70 holds the cloth 50 to be held.

  When the middle presser 21 ascends, the middle presser bar holder 26 abuts on the connecting member 32 by the biasing force of the biasing member 24. The height position of the pin 34 is lower than the upper end of the elongated hole 36. At this time, the middle presser 21 is moved to the retracted position (see FIG. 16) which is a height position at which it is separated upward from the cloth held by the cloth holder 70. The retracted position is a position retracted upward from the contact position. The presser foot 21 is moved to the contact position during a penetration period, which is a period during which the sewing needle 20 sticks to the cloth 50. After the start of the non-penetrating period, which is a period in which the sewing needle 20 is above the cloth 50, the middle presser 21 moves to the retracted position.

  The middle presser 21 may contact the cloth 50 intermittently while in the contact position, or may continuously contact the cloth 50. For example, when the cloth 50 is displaced in the vertical direction as the sewing needle 20 moves up and down, the middle presser 21 at the contact position intermittently contacts the cloth 50 when displaced upward. Also, if the contact position is sufficiently close to the pinching frame 12, the middle presser 21 continuously contacts the cloth 50 while in the contact position.

  The intermediate pressing motor 23 can change the rotation range of the output shaft 49. The change of the rotation range of the output shaft 49 includes the change of the intermediate rotation position in the rotation range of the output shaft 49 and the rotation width (δ1 of FIG. 6) of the output shaft 49. When the rotation range of the output shaft 49 changes, the swing range of the link 33 changes. Therefore, the middle presser 9 can change the range in which the middle presser 21 moves up and down. The change of the range in which the middle presser 21 vertically moves includes the change of the vertical movement amount of the middle presser 21 and the change of the contact position and the retracted position of the middle presser 21. When the rotation width of the output shaft 49 changes, the amount of vertical movement of the middle presser 21 changes. When the specific position which is the lower end of the rotation range of the output shaft 49 changes, the contact position of the middle presser 21 changes. Hereinafter, the angle (rotation angle phase) of the output shaft 49 is referred to as a rotation angle δ. The rotation angle δ is, for example, an angle that makes clockwise clockwise in a front view with reference to an imaginary straight line T extending rightward from the center of the output shaft 49.

  The sewing machine 1 of the present embodiment controls driving of the presser foot motor 23 in one of the normal mode and the special mode. The normal mode is a mode in which the middle presser 21 reciprocates up and down each time the needle bar 19 reciprocates up and down. In other words, in the normal mode, the middle presser 21 reciprocates up and down each time the sewing mechanism 15 performs sewing for one stitch. The special mode is a mode in which the presser foot 21 is in the contact position while the needle bar 19 reciprocates a plurality of times. In other words, in the special mode, the middle presser 21 is located at the contact position while the sewing mechanism 15 performs the specific sewing which is the sewing for the predetermined number of stitches having two or more needles. The specific sewing of this embodiment is, as an example, the sewing of the sewing start of the cloth 50 by the sewing mechanism 15.

  The vertical movement timing and the like of the needle bar 19 and the middle presser 21 in the normal mode will be described with reference to FIG. The vertical axis on the right side of FIG. 7 indicates the height position of the lower end of the sewing needle 20 based on the upper surface of the needle plate 13 (the same applies to FIG. 8). When the spindle angle θ (hereinafter referred to as spindle angle θ) is H1 and when the spindle angle θ is H2, the lower end of the sewing needle 20 is at the same height position as the upper surface of the cloth 50. That is, in FIG. 7, the penetration period of the sewing needle 20 is when the spindle angle θ is larger than H1 and smaller than H2. Further, in FIG. 7, the non-penetration period of the sewing needle 20 is when the spindle angle θ is less than H1 and when the spindle angle θ is larger than H2. H1 and H2 are values that change according to the thickness of the cloth 50. H1 and H2 are respectively values which exist during one rotation of the main shaft.

  The vertical axis on the left side of FIG. 7 indicates the height position of the middle presser 21 based on the contact position (the same applies to FIG. 8). The height position 3 mm of the middle presser 21 is an example of the retracted position. That is, the vertical movement amount of the middle presser 21 in the drawing is 3 mm. The contact position is a position higher than the top surface of the needle plate 13.

  In FIG. 7, when the spindle angle θ becomes K and when the spindle angle θ becomes M are middle presser up and down timings in which the middle presser 21 moves up and down. Specifically, when the spindle angle θ is K, the middle presser 21 moves from the retracted position to the contact position, and when the spindle angle θ is M, the middle presser 21 moves from the contact position to the retracted position. K is less than H1 and M is greater than H2. K and M are initial values stored in the sewing machine 1, and the sewing machine 1 can accept changes in K and M. That is, the sewing machine 1 can accept the change of the middle presser up and down timing. When β, which is the change value of K and M, is a negative number, the middle presser up and down timing is advanced, and when β is a positive number, the middle presser up and down timing is delayed. Second dashed dotted lines P1 and P2 shown in FIG. 7 indicate middle presser up and down timings advanced by β.

  The thick solid line extending in the longitudinal direction when the spindle angle θ is K and M in FIG. 7 indicates the vertical movement of the middle presser 21. The vertically extending thick solid line is exactly at a slight angle to the longitudinal axis. That is, in the actual machine, the middle presser 21 moves between the retracted position and the contact position while the spindle angle θ is within the predetermined angle range. In FIG. 7, a thick solid line extending in the vertical direction is illustrated substantially parallel to the vertical axis (the same applies to FIG. 8) for the sake of easy viewing of the drawing.

  In FIG. 7, a feeding period which is a period in which the cloth holder 70 (see FIG. 1) holding the cloth 50 moves is also illustrated. The movement direction of the cloth holder 70 includes the left-right direction and the front-rear direction. In FIG. 7, the cloth holder 70 moves in the range in which the spindle angle θ is 0 or more and less than J, and the cloth holder 70 stops in the range in which the spindle angle θ is J or more and less than L. The cloth holder 70 moves in the range where the angle θ is L or more and less than 360. J is smaller than K, L is larger than M. Therefore, in the normal mode, the cloth holder 70 moves within the non-penetration period, and the cloth holder 70 stops during the penetration period.

  J and L are initial values stored in the sewing machine 1, and the sewing machine 1 can accept changes in J and L. That is, the sewing machine 1 can accept the change of the sending period. The change of the feeding period is a change of the movement start time and the movement end time of the cloth holder 70. Before and after the change of the feeding period, the time required for the cloth holder 70 to move does not change. When α, which is a modified value of J and L, is a negative number, the sending period is advanced, and when α is a positive number, the sending period is delayed. The second dot-and-dash line Q1, Q2 shown in FIG. 7 indicates a feeding period advanced by α. In the normal mode, J + α is equal to or less than K + β. When J + α is larger than K + β, the middle presser 21 in the contact position comes into contact with the moving cloth 50 when the sewing process in the normal mode (see FIG. 15) is performed. In this case, the intermediate presser 21 inhibits the movement of the cloth 50, which may result in sewing failure.

  The vertical movement timing and the like of the needle bar 19 and the middle presser 21 in the special mode will be described with reference to FIG. The special mode in FIG. 8 illustrates a specific sewing in which the predetermined number of stitches is two, as an example. That is, when the spindle angle θ reaches 720 °, the specific sewing is completed. In the special mode, the middle presser 21 is in the contact position while the sewing mechanism 15 performs the specific sewing. When the spindle angle θ is M + 360 °, the middle presser 21 moves from the contact position to the retracted position. The timing at which the intermediate presser 21 moves to the retracted position is after the end of the penetration period corresponding to the final stitch number of the specific sewing and before the start of the feed period. In the special mode, as in the normal mode, it is possible to receive changes in the middle presser-lifting timing and the feeding period. The sending period in the special mode is the same as the sending period in the normal mode. Α and β in FIG. 8 are the same as α and β shown in FIG.

  The electrical configuration of the sewing machine 1 will be described with reference to FIG. The control unit 30 of the sewing machine 1 includes a CPU 91. The CPU 91 controls the operation of the sewing machine 1. The CPU 91 is connected to the ROM 92, the RAM 93, the storage device 94, and an I / O interface (hereinafter referred to as I / O) 96. The ROM 92 stores programs and the like for executing various processes such as a first main process described later (see FIG. 11). The ROM 92 stores K, M, J, L, etc. shown in FIG. 7 as initial values. The RAM 93 temporarily stores various values. The storage device 94 is non-volatile. The storage device 94 stores sewing information, intermediate presser information 95, and the like. The sewing information is information for forming a stitch on the cloth 50. The sewing information associates and stores a stitch number number and coordinate information indicating a needle drop point. The needle drop point is a position where the sewing needle 20 is to stick the cloth 50 when the needle bar 19 moves up and down. The intermediate presser information 95 will be described later.

  The I / O 96 is connected to the drive circuits 81 to 86 and the input unit 97. The drive circuit 81 is connected to the main motor 27. The drive circuit 82 is connected to the X motor 41. The drive circuit 83 is connected to the Y motor 42. The drive circuit 84 is connected to the intermediate presser motor 23. The X motor 41, the Y motor 42, and the middle pressing motor 23 are all pulse motors. The drive circuit 85 is connected to the pair of air cylinders 79. The drive circuit 86 is connected to the display unit 98. The CPU 91 controls the drive circuits 81 to 86 to drive and control the main motor 27, the X motor 41, the Y motor 42, the intermediate pressing motor 23, and the pair of air cylinders 79. The input unit 97 detects information input by the worker and outputs the detection result to the CPU 91.

  The main motor 27, the X motor 41, the Y motor 42, and the middle pressing motor 23 are connected to the encoders 101 to 104, respectively. The encoder 101 detects the rotational position of the output shaft of the main motor 27. The detection result detected by the encoder 101 corresponds to the spindle angle θ. The encoder 102 detects the rotational position of the output shaft of the X motor 41. The encoder 103 detects the rotational position of the output shaft of the Y motor 42. The encoder 104 detects the rotational position of the output shaft 49 of the presser foot motor 23. The encoders 101 to 104 output the detection result to the CPU 91.

  The middle presser information 95 will be described with reference to FIG. The middle presser information 95 is an output shaft associated with “high”, “middle”, “low” indicating the height position of the contact position, and “middle” or “large” indicating the vertical movement amount of the middle presser 21. 49 rotation angles δ are included. When the rotation angle δ of the output shaft 49 is a1, a2 or a3, the middle presser 21 is in the contact position, and when the rotation angle δ is b1, b2, b3, c1, c2 or c3, the middle presser 21 Is in the retracted position.

  The first main process will be described with reference to FIG. When the operator inputs an instruction to start the first main processing to the input unit 97, the CPU 91 reads a program from the ROM 92 and starts the first main processing. Before starting the first main, the operator places the standard cloth 51 on the sandwiching frame 12, the presser frame 11 is at the separated position, and the middle presser 21 is at the retracted position.

  The CPU 91 drives and controls the pair of air cylinders 79 to move the presser frame 11 to the holding position (S9). The cloth holder 70 holds the standard cloth 51 by moving the pressing frame 11 to the holding position. The CPU 91 receives the selection of the special mode based on the detection result of the input unit 97 (S10). The CPU 91 stands by until the detection result of the input unit 97 is obtained. For example, when the worker inputs the selection “Yes” of the special mode into the input unit 97, the CPU 91 stores information indicating that the special mode is selected in the RAM 93 (S10).

  The CPU 91 refers to the storage device 94 and acquires sewing information (S11). The CPU 91 acquires a predetermined number of stitches (S13). For example, the CPU 91 acquires the predetermined number of stitches input to the input unit 97 by the worker. The CPU 91 specifies an accumulated main spindle angle θ (hereinafter, referred to as a specific main spindle angle θ) at the end of the specific sewing based on the acquired predetermined number of stitches (S13). The cumulative spindle angle θ can be obtained by 360 ° × predetermined number of stitches. When the sewing mechanism 15 finishes sewing a predetermined number of stitches from the start of sewing, the spindle angle θ becomes the specific spindle angle θ. At this time, the sewing needle 20 is above the standard cloth 51.

  The CPU 91 acquires sending change information indicating a change of the sending period (S15). For example, when the worker inputs a value corresponding to α illustrated in FIGS. 7 and 8 to the input unit 97, the CPU 91 acquires the feed change information. If the worker inputs 0 as α to the input unit 97, the sending period remains at the initial value. Therefore, CPU91 acquires the sending period which cloth holder 70 moves within the non penetration period by performing S15. The CPU 91 acquires presser change information indicating a change in the middle presser upper and lower timing (S17). In the present embodiment, the CPU 91 sets the same value as α acquired in S15 as β (S17). When β is 0, the middle presser up and down timing remains at the initial value.

  The CPU 91 acquires the vertical movement amount of the middle presser 21 (S19). The worker inputs, for example, "middle" as the vertical movement amount of the middle presser 21 (S19). The CPU 91 acquires the height position of the contact position of the middle presser 21 (21). The operator inputs, for example, "middle" as the contact position of the middle presser 21 (S21). The CPU 91 acquires the rotation range of the output shaft 49 of the intermediate pressing motor 23 (S23). The CPU 91 refers to the middle presser information 95 (see FIG. 10), and acquires the rotation angle δ corresponding to the vertical movement amount acquired in S19 and the height position of the contact position acquired in S21. For example, the CPU 91 acquires a2 ≦ δ ≦ b2 as the rotation range of the output shaft 49 (S23).

  The CPU 91 refers to the RAM 93, and determines whether the selection of the special mode has been received in S10 (S24). When the worker inputs the selection "YES" of the special mode to the input unit 97 (S10), the CPU 91 determines that the selection of the special mode is received (S24: YES), and shifts the processing to S25.

  The CPU 91 drives and controls the intermediate presser motor 23 to move the intermediate presser 21 to the contact position (S25). The middle presser 21 moves from the upper side to the standard cloth 51 by moving to the contact position (see FIG. 13). At this time, the rotation angle δ of the output shaft 49 is a2 (S25). The CPU 91 executes the sewing process in the special mode (S27).

The sewing process in the special mode will be described with reference to FIGS. 1 and 12 to 14. The CPU 91 drives the sewing mechanism 15 by starting the driving of the main motor 27 (S31). The needle bar 19 and the sewing needle 20 start moving up and down, and the hook rotates in synchronization with the needle bar 19. The CPU 91 controls the X motor 41 and the Y motor 42 to start moving the cloth holder 70 (S33). For example, the cloth holder 70 moves the standard cloth 51 in the left direction (arrow M1 in FIG. 13). The movement direction of the cloth holder 70 may be rightward or longitudinal. The CPU 91 determines whether or not the cloth feeding by the cloth holder 70 is finished (S35). For example, the CPU 91 determines whether or not to end the cloth feeding by determining whether or not the formula (1) is established.
θ = (J + α) + 360 × N (1)
N is an integer greater than or equal to 0, and is incremented by one each time the spindle angle θ increases by 360 °. As the main motor 27 is driven, the spindle rotates and the spindle angle θ increases. The CPU 91 stands by until the equation (1) is established (S35: NO). While the CPU 91 is waiting (S35: NO), the sewing needle 20 is lowered toward the standard cloth 51 (arrow D1 in FIG. 13). Before the sewing needle 20 passes through the through hole 21A and pierces the standard cloth 51, formula (1) is satisfied (S35: YES), the CPU 91 controls the X motor 41 and the Y motor 42 to control the cloth holder 70. Stop moving (S37). After the movement of the cloth holder 70, the sewing needle 20 pierces the standard cloth 51, passes through the needle hole 16 and reaches the hook (see FIG. 14). The rotating hook entangles the lower thread drawn from the bobbin with the upper thread held by the eye 20A of the sewing needle 20.

  The CPU 91 determines whether or not the specific sewing is completed when the sewing needle 20 moving up and down moves above the standard cloth 51 (S39). For example, the CPU 91 acquires the spindle angle θ based on the detection result of the encoder 101. The CPU 91 determines whether the first angle difference, which is the difference between the acquired spindle angle θ and the specific spindle angle θ acquired in S13, is less than 180 (S39). When the first angle difference is 180 or more, the CPU 91 determines that the specific sewing is not completed (S39: NO), and shifts the processing to S41.

The CPU 91 determines whether to start the feeding by the cloth holder 70 (S41). For example, the CPU 91 determines whether or not to start the cloth feeding by determining whether or not the equation (2) is established.
θ = (L + α) + 360 × N (2)
The CPU 91 waits until the equation (2) is established (S41: NO). While the CPU 91 is waiting (S41: NO), the sewing needle 20 moves upward (arrow U1 in FIG. 14). The frictional force generated between the sewing needle 20 and the standard cloth 51 biases the standard cloth 51 upward. The middle presser 21 at the contact position contacts the standard cloth 51, and the sewing machine 1 suppresses the lifting of the standard cloth 51. After the sewing needle 20 is pulled out above the standard cloth 51, the formula (2) is satisfied (S39: YES), and the CPU 91 shifts the processing to S33.

  While the CPU 91 repeats S33 to S41, the sewing needle 20 repeatedly moves up and down. The cloth holder 70 moves the standard cloth 51 within the non-penetration period of the sewing needle 20 and stops the standard cloth 51 during the penetration period of the sewing needle 20. Since the sewing machine 1 places the middle presser 21 at the contact position while the sewing mechanism 15 performs the specific sewing, the middle presser 21 can contact the standard cloth 51 stably.

When the CPU 91 determines that the specific sewing is completed (S39: YES), the process proceeds to S43. The CPU 91 determines whether to move the presser foot 21 to the retracted position (S43). For example, the CPU 91 determines whether or not to move the intermediate presser 21 to the retracted position by determining whether or not Expression (3) is established.
θ = (M + β) + 360 × N (3)
The CPU 91 stands by until the formula (3) is established (S43: NO). While the CPU 91 is waiting (S43: NO), the sewing needle 20 moves upward (arrow U1 in FIG. 14), and is pulled upward from the standard cloth 51. When the equation (3) is established (S43: YES), the CPU 91 drives and controls the intermediate presser motor 23 to move the intermediate presser 21 to the retracted position (S45). At this time, the rotation angle δ of the output shaft 49 is b2 (S45). The sewing needle 20 is pulled upward from the standard cloth 51 (see FIG. 16). The CPU 91 ends the sewing process of the special sewing mode, and returns to the first main process (see FIG. 12). The CPU 91 executes the normal mode sewing process (S29).

  The sewing process in the normal mode will be described with reference to FIGS. The CPU 91 drives and controls the X motor 41 and the Y motor 42 to start the movement of the cloth holder 70 (S51). S51 is the same process as S33. With the intermediate presser 21 in the retracted position, the cloth holder 70 moves the standard cloth 51 to the left (arrow M2 in FIG. 16). The CPU 91 determines whether or not the cloth feeding by the cloth holder 70 is ended (S53). S53 is the same process as S35. While the CPU 91 is waiting (S53: NO), the sewing needle 20 is lowered toward the standard cloth 51 (arrow D3 in FIG. 16). When the equation (1) is established (S53: YES), the CPU 91 stops the cloth holder 70 (S55). S55 is the same process as S33.

The CPU 91 determines whether to move the presser foot 21 to the contact position (S57). The CPU 91 determines whether the middle presser 21 is to be moved to the contact position by determining whether the equation (4) is established.
θ = (K + α) + 360 × N (4)
The CPU 91 waits until the formula (4) is established (S57: NO). Before the descending sewing needle 20 reaches the standard cloth 51, formula (4) is satisfied (S57: YES), and the CPU 91 drives and controls the middle presser motor 23 to move the middle presser 21 to the contact position (S59) . At this time, the rotation angle δ of the output shaft 49 is a2 (S59). After the middle presser 21 reaches the contact position (S59), the sewing needle 20 penetrates the standard cloth 51 and reaches the hook (see FIG. 14). The rotating hook entangles the lower thread drawn from the bobbin with the upper thread held by the eye 20A of the sewing needle 20.

  The CPU 91 determines whether to move the presser foot 21 to the retracted position (S61). S61 is the same process as S43. The CPU 91 waits until the equation (3) is established (S61: NO). While the CPU 91 is waiting, the sewing needle 20 starts moving upward (arrow U1 in FIG. 14), and is pulled upward from the standard cloth 51. When the equation (3) is established (S61: YES), the CPU 91 drives and controls the intermediate presser motor 23 to move the intermediate presser 21 to the retracted position (S63). S63 is the same process as S45.

  The CPU 91 determines whether to start the feeding by the cloth holder 70 (S65). S65 is the same process as S41. The CPU 91 waits until the equation (2) is established (S65: NO). If Formula (2) is materialized (S65: YES), CPU91 will shift processing to S67.

  The CPU 91 determines whether the sewing is completed (S67). For example, the CPU 91 acquires the spindle angle θ based on the detection result of the encoder 101. The CPU 91 determines whether the second angle difference, which is the difference between the acquired spindle angle θ and the spindle angle θ at the end of the last stitch number indicated by the sewing information, is less than 180. When the second angle difference is 180 or more, the CPU 91 determines that the sewing is not completed (S67: NO), and shifts the processing to S51.

  The CPU 91 repeatedly executes S51 to S67 so that the sewing mechanism 15 sequentially performs sewing on the standard cloth 51. At this time, the middle presser 21 moves from the retracted position to the contact position (arrow D3 in FIG. 16) during the period other than the feeding period of the cloth holder 70. The intermediate presser 21 moves from the contact position to the retracted position after the end of the penetration period and before the start of the feeding period of the cloth holder 70 (see arrow U3 in FIG. 16). The vertical movement amount of the middle presser 21 corresponds to the dimension Y1 of FIG.

  When the second angle difference is less than 180, the CPU 91 determines that the sewing is completed (S67: YES), and stops driving the main motor 27 (S69). The CPU 91 ends the sewing process in the normal sewing mode, and returns to the first main process (see FIG. 11). The CPU 91 ends the first main process.

  The first main process when the sewing mechanism 15 (see FIG. 1) sews the thick cloth 52 will be described with reference to FIGS. 11, 12, and 17. FIG. The description overlapping with the first main process described above will be omitted below. Before the start of the first main processing, the worker places the thick cloth 52 on the sandwiching frame 12 instead of the standard cloth 51.

  The CPU 91 executes S9 to S17. At this time, the worker inputs the selection “Yes” of the special mode to the input unit 97 (S10). The operator inputs "middle" to the input unit 97 as the vertical movement amount of the middle presser 21, and inputs "high" to the input unit 97 as the height position of the contact position (S21). The CPU 91 refers to the middle presser information 95 and acquires a1 ≦ δ ≦ b1 as the rotation range of the output shaft 49 (S23). The CPU 91 determines that the selection of the special mode has been received (S24: YES), and moves the middle presser 21 to the contact position (S25). At this time, the rotation angle δ of the output shaft 49 is a1 (S25). The contact position of the middle presser 21 is on the upper side compared to when sewing the standard cloth 51 (see FIG. 17).

  When the special mode sewing process (see FIG. 12) is performed, the cloth holder 70 moves the thick cloth 52 leftward as an example (arrow M3 in FIG. 17). While the sewing mechanism 15 (see FIG. 1) performs the special sewing, the CPU 91 places the middle presser 21 at the contact position. At the timing when the special sewing ends, the CPU 91 moves the intermediate presser 21 to the retracted position (arrow U4). At this time, the rotation angle δ of the output shaft 49 is b1. The retracted position of the intermediate presser 21 is above the sewing position of the standard cloth 51.

  The CPU 91 executes the normal mode sewing process (S29). The middle presser 21 vertically moves between the contact position and the retracted position while the CPU 91 executes S51 to S67. The vertical movement amount of the middle presser 21 is the same as when sewing the standard cloth 51, and corresponds to the dimension Y1 in FIG. The CPU 91 ends the normal mode sewing process and ends the first main process.

  The first main process when the sewing mechanism 15 (see FIG. 1) sews the special cloth 53 will be described with reference to FIGS. 11, 12, and 18. FIG. Before the start of the first main processing, the operator places the special cloth 53 on the sandwiching frame 12 instead of the standard cloth 51.

  After the CPU 91 moves the presser frame 11 to the holding position (S9), the operator inputs the special sewing mode "absent" to the input unit 97 (S10). Since the special cloth 53 is light and soft, when the sewing process in the special mode is performed, the middle presser 21 may be caught by the special cloth 53 and may inhibit the movement of the special cloth 53. Therefore, when sewing the special cloth 53, it is preferable not to apply the special sewing mode. After the CPU 91 executes S11 to S17, the operator inputs "large" as the vertical movement amount of the middle presser 21 to the input unit 97 (S19), and inputs "low" as the height position of the contact position. It inputs into 97 (S21). The CPU 91 refers to the middle presser information 95, and acquires a3 ≦ δ ≦ c3 as the rotation range of the output shaft 49 (S23). The CPU 91 determines that the selection of the special mode is not received (S24: NO), and executes the sewing process of the normal mode (S29).

  The CPU 91 executes S51 to S67. When the CPU 91 executes S59, the middle presser 21 moves to the contact position. At this time, the rotation angle δ of the output shaft 49 is a3, and the contact position of the middle presser 21 is lower than when the standard cloth 51 is sewn (see FIG. 18). When the CPU 91 executes S63, the middle presser 21 moves to the retracted position. The rotation angle δ of the output shaft 49 is c3. The retracted position of the intermediate presser 21 is on the upper side as compared to the time of sewing the standard cloth 51 (see FIG. 18). The vertical movement amount of the intermediate presser 21 moving up and down between the contact position and the retracted position is larger than that at the time of sewing the standard cloth 51, and corresponds to the dimension Y2 in FIG. At the time of execution of the normal mode sewing process, due to the lightness and softness of the special cloth 53, even when the upstream portion (the special cloth 53 right part in FIG. 18) of the special cloth 53 is lifted due to the vertical movement of the sewing needle 20 The middle presser 21 in the retracted position is moved to the upper side than the special fabric 53 which is lifted. Therefore, since the middle presser 21 does not inhibit the movement of the special cloth 53, the sewing machine 1 can sew the special cloth 53 stably.

  As described above, the CPU 91 moves the middle presser 21 to the contact position (S25) before execution of the special mode sewing process (S27). While the sewing mechanism 15 performs the specific sewing, the sewing machine 1 places the presser foot 21 at the contact position. The CPU 91 moves the intermediate presser 21 to the retracted position after the end of the penetration period corresponding to the final stitch number of the specific sewing and before the start of the feeding period (S45). In the normal mode sewing process, the CPU 91 moves the middle presser 21 from the retracted position to the contact position during the period other than the feed period (S59), and after the penetration period is completed after the middle presser 21 moves to the contact position Before the start of the period, the middle presser 21 is moved from the contact position to the retracted position (S63). When the operator inputs the special mode "presence" to the input unit 97 (S24: YES), the sewing machine 1 normally performs the sewing process (S27) in the special mode according to the predetermined number of stitches which is an example of the sewing state. The sewing process (S29) of the mode is executed. The sewing machine 1 can change the arrangement time at the contact position of the middle presser 21 according to the sewing state. Therefore, the sewing machine 1 is realized in which the middle presser 21 stably contacts the cloth 50 even if the sewing state changes.

  Specific sewing is sewing at the beginning of sewing. At the beginning of sewing, the middle presser 21 continues to be placed in the contact position, so the cloth 50 easily contacts the middle presser 21. While the sewing mechanism 15 performs the special sewing at the start of sewing, the sewing machine 1 can stabilize the frictional force generated between the upper thread and the cloth 50. The sewing machine 1 can appropriately supply the upper thread to the cloth 50, and can particularly suppress the falling-off of the upper thread from the eye 20A of the upper thread that is likely to occur at the start of sewing. Therefore, since the sewing machine 1 can suppress eye jumps and the like in which no stitches are formed on the cloth 50, the quality of sewing on the cloth 50 can be improved.

  The operator can input the specific number of stitches to the input unit 97 (S13). The operator can set the number of stitches in the special mode sewing process to a desired number of stitches. That is, the sewing machine 1 keeps arranging the presser foot 21 at the contact position by the number of needles desired by the operator. Therefore, the usability of the sewing machine 1 is improved. The operator can set the contact position of the middle presser 21 in the vertical direction according to the thickness of the cloth 50 (S21). Therefore, the usability of the sewing machine 1 is improved.

  The operator can set the feed period and the middle presser up and down timing (S15, S17). In other words, the sewing machine 1 can change the timing at which the middle presser 21 is moved from the contact position to the retracted position in accordance with the change of the feed period. Even when the movement timing of the cloth holder 70 with respect to the vertical movement of the needle bar 19 during execution of the special mode sewing process changes (S17), the middle presser 21 at the contact position can stably contact the cloth 50.

  As described above, the intermediate presser motor 23 is an example of the intermediate presser driving unit according to the present invention. The main motor 27, the X motor 41, and the Y motor 42 are examples of the drive unit of the present invention. CPU91 which performs S27 and S29 is an example of a sewing control part of the present invention. CPU91 which performs S59 and S63 is an example of the 1st middle pressing control part of this invention. CPU91 which performs S25 and S45 is an example of the 2nd middle press control part of this invention. S27 and S29 are examples of the sewing control unit of the present invention. S59 and S63 are an example of the first presser control process of the present invention. S25 and S45 are an example of the second presser control process of the present invention.

  The present invention is not limited to the above embodiments. The CPU 91 may perform the sewing process for the number of stitches of the sewing information in the special mode sewing process according to the type of the cloth 50. For example, when the worker places the leather cloth 50 on the sandwiching frame 12, the CPU 91 may perform sewing for all the number of stitches in the special mode sewing process. In the present modification, the type of cloth of the cloth 50 is an example of the sewing state. The sewing state may be the thickness of the sewing needle 20, the length of the sewing needle 20, the type of upper thread, or the like. The CPU 91 may execute the sewing process in the normal mode and then execute the sewing process in the special mode, or may alternately execute the sewing process in the normal mode and the sewing process in the special mode. The storage device 94 may store a predetermined number of stitches. At this time, the CPU 91 may not execute S13.

  Instead of inputting “medium” or “large” as the vertical movement amount of the middle presser 21 to the input unit 97 (S19), the operator may input the vertical movement amount of the middle presser 21 to the input unit 97 numerically. Instead of inputting “high”, “middle” or “low” to the input unit 97 as the height position of the contact position (S21), the worker may, for example, measure the height of the contact position based on the upper surface of the needle plate 13. The position may be input to the input unit 97 as a numerical value. At this time, the CPU 91 substitutes the vertical movement amount of the middle presser 21 and the height position of the contact position in a relational expression relating the vertical movement amount of the middle presser 21, the height position of the contact position, and the pivot range of the output shaft 49. By doing this, the rotation range of the output shaft 49 may be acquired (S23).

  The CPU 91 executing S17 may set a value different from α, instead of setting the same value as α as β. For example, the CPU 91 may acquire presser change information by the worker inputting a numerical value corresponding to β illustrated in FIGS. 7 and 8 into the input unit 97.

  The timing at which the middle presser 21 moves to the retracted position may be different between the normal mode sewing process and the special mode sewing process. The contact position of the middle presser 21 may be different between the normal mode and the special mode sewing process.

1 sewing machine 15 sewing mechanism 19 needle bar 20 sewing needle 21 middle presser 22 middle presser bar 23 middle presser motor 27 main motor 41 X motor 42 Y motor 50 cloth 70 cloth holder 91 CPU
97 Input section

Claims (6)

A cloth holder capable of holding a cloth and moving horizontally;
A sewing mechanism capable of moving up and down above the cloth held by the cloth holder and having a needle bar at the lower end of which a sewing needle is mounted, and sewing the cloth with the sewing needle;
In a sewing machine provided with a driving unit for driving the cloth holder and the sewing mechanism,
A presser bar which extends vertically in parallel with the needle bar and which can move up and down above the cloth;
A presser driving unit that moves the presser bar up and down;
An intermediate presser attached to the lower end of the intermediate presser bar,
The drive unit is driven and controlled, and the cloth holder is moved within a non-penetration period in which the sewing needle is above the cloth, and the cloth holder is stopped during a penetration period in which the sewing needle pierces the cloth. A sewing control unit for performing sewing on the cloth;
When the sewing control unit sews the cloth, drive control of the middle presser driving unit is performed to retract the middle presser to a contact position where it contacts the cloth from above and a retraction position above the contact position. A presser foot control unit that moves up and down between positions;
The cloth holder moves during the non-penetration period when the sewing control unit sews the cloth,
The intermediate presser control unit
The intermediate presser is moved from the retracted position to the contact position during a period other than the feeding period, which is a period during which the cloth holder moves, and after the intermediate period is moved to the contact position A first middle press control unit that moves the middle presser from the contact position to the retracted position before the start of the feeding period;
The middle presser is disposed at the contact position while the sewing control unit executes the specific sewing which is the sewing of the predetermined number of stitches having two or more needles, and the penetration period corresponding to the final number of stitches of the specific sewing is ended. And a second presser control unit that moves the presser to the retracted position before the start of the feed period.
A sewing machine in which any one of the first middle pressing control unit and the second middle pressing control unit controls driving of the middle pressing drive unit. The specific sewing is sewing of the predetermined number of stitches from the start of sewing,
The sewing machine according to claim 1, wherein the first middle pressing control unit controls driving of the middle pressing after drive control of the middle pressing drive unit by the second middle pressing control unit. It has an input unit to which setting of the predetermined number of stitches is input,
The second presser control unit arranges the cloth at the contact position while the sewing control unit executes the specific sewing which is sewing of the predetermined number of stitches input to the input unit. The sewing machine according to claim 1 or 2. It has an input unit to which the setting of the vertical direction which is the contact position of the middle presser in the drive control by the second middle presser control unit is input,
The second middle press control unit drives and controls the middle press drive unit such that the vertical position input to the input unit is the contact position. The sewing machine described in one. The sewing control unit can change the feed period,
The second middle press control unit changes the timing of moving the middle presser from the contact position to the retracted position according to the feeding period changed by the sewing control unit. The sewing machine according to any one of 4. A cloth holder capable of holding a cloth and moving horizontally;
A sewing mechanism capable of moving up and down above the cloth held by the cloth holder and having a needle bar at the lower end of which a sewing needle is mounted, and sewing the cloth with the sewing needle;
A drive unit for driving the cloth holder and the sewing mechanism;
A presser bar which extends vertically in parallel with the needle bar and which can move up and down above the cloth;
A presser driving unit that moves the presser bar up and down;
A control method of a sewing machine, comprising: an intermediate presser attached to a lower end of the intermediate presser bar,
The drive unit is driven and controlled, the sewing needle moves the cloth holder within a non-penetration period above the cloth, and the cloth holder is penetrated during the penetration period while the sewing needle pierces the cloth. A sewing control step of stopping and performing sewing on the cloth;
When sewing on the cloth in the sewing control step, drive control of the middle presser drive unit is performed to retract the middle presser from the contact position where it contacts the cloth from above and the retraction position above the contact position. An intermediate presser control process that moves up and down between positions;
The cloth holder moves between the non-penetration periods when sewing on the cloth in the sewing control step,
The intermediate presser control process is
The intermediate presser is moved from the retracted position to the contact position during a period other than the feeding period, which is a period during which the cloth holder moves, and after the intermediate period is moved to the contact position A first middle presser control step of moving the middle presser from the contact position to the retracted position before the start of the feeding period;
The middle presser is disposed at the contact position while performing the specific sewing which is sewing of a predetermined number of stitches having two or more needles in the sewing control process, and the penetration period corresponding to the final number of stitches of the specific sewing is completed. And a second middle presser control step of moving the middle presser to the retracted position before and before the start of the feeding period;
A control method of a sewing machine, wherein drive control of the middle presser driving unit is performed in any one of the first middle presser control process and the second middle presser control process.

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