Sewing machine

Abstract

The invention provides a sewing machine capable of changing the size of a gap formed in a stroke fixing device. The shuttle mechanism (20) has a case (20A), a bobbin case (24), a shuttle hook (25), and a stopper (30). The stopper (30) has a fixed member (31) including an abutment portion (37) and a movable member (32) including an abutment portion (38). The abutting portion and the abutting portion (38) face each other in the front-rear direction. A shuttle stopper portion (26) extending from a base portion (25A) of the shuttle (25) passes through a gap (S) formed between the contact portion (37) and the contact portion (38). The contact portion restricts the forward rotation of the shuttle by coming into contact with the shuttle stopper portion. The contact section (38) restricts the reverse rotation of the shuttle (25) by coming into contact with the shuttle stopper section. The fixing member is fixed relative to the groove (20E) of the box body (20A). The movable member is provided so as to be capable of moving in the front-rear direction by being driven by the direct-acting cylinder.

Description

Technical Field

[0001] The invention relates to a sewing machine. Background Art

[0002] It is known that there is a shuttle device of a sewing machine that limits the rotation of a shuttle within a certain range. For example, the shuttle device described in Patent Document 1 includes a needle plate, a shuttle case, and a shuttle. A pair of stoppers are provided at the lower end of the needle plate in a manner that is spaced apart from each other. The shuttle case can rotate around a vertical axis. The shuttle is housed in the shuttle case and can rotate relative to the shuttle case. A shuttle stopper is provided on the outer periphery of the shuttle. The shuttle stopper is inserted into the gap formed between the pair of stoppers. The rotation of the shuttle is limited within a certain range by the shuttle stopper abutting against the pair of stoppers.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 8-299645 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The shuttle device captures the upper thread passing through the needle and entangles it with the lower thread. If the gap formed between the pair of stoppers is too narrow, the upper thread may be hooked on the pair of stoppers and untwisted. If the gap is too wide, the rotation of the shuttle may not be fully suppressed. Therefore, it is desired that the shuttle device can change the size of the gap.

[0008] An object of the present invention is to provide a sewing machine capable of changing the size of a gap formed in a stopper.

[0009] Solutions for solving problems

[0010] A sewing machine according to one embodiment of the present invention is characterized in that it has a shuttle mechanism for capturing the upper thread passing through the machine needle and winding it with the lower thread, the shuttle mechanism comprising: a shuttle case, which includes a shuttle tip capable of capturing the upper thread and capable of rotating around an axis extending in the up-down direction; a shuttle that accommodates the lower thread and can rotate around the axis relative to the shuttle case on the inner side of the shuttle case; a shuttle stopper that is connected to the outer periphery of the shuttle and can rotate around the axis as a whole with the shuttle and extends in a predetermined first direction in a radial direction centered on the axis; and a stopper that has a first component and a second component.

[0011] The first member has a first abutment portion, which can abut against the shuttle stop portion that rotates in the forward direction during the rotation around the axis line. The second member has a second abutment portion, which can abut against the shuttle stop portion that rotates in the reverse direction opposite to the forward rotation. The first abutment portion and the second abutment portion are relative to each other in a second direction that intersects with and is horizontal to the first direction. By moving at least one of the first member and the second member along the second direction, the size of the gap formed between the first abutment portion and the second abutment portion can be changed.

[0012] According to the above embodiment, in the sewing machine, the stopper uses the first abutment and the second abutment to limit the rotation of the shuttle stopper about the axis. The sewing machine can change the size of the gap formed between the first abutment and the second abutment by moving at least one of the first member and the second member in the second direction.

[0013] Alternatively, a sewing machine according to one aspect of the present invention may include: a driving unit connected to at least one of the first member and the second member to move at least one of the first member and the second member in the second direction; and a control unit that controls the movement of at least one of the first member and the second member in the second direction by the driving unit when sewing using the shuttle mechanism. In this case, the size of the gap of the stopper can be easily changed compared to a case where the sewing machine does not use the driving unit to move at least one of the first member and the second member.

[0014] In a sewing machine of one embodiment of the present invention, the driving unit may be connected to the second member. In the sewing machine, the shuttle stopper is usually rotated in a forward direction integrally with the shuttle, and therefore, it is easy to abut against the first abutment portion of the first member. The sewing machine moves the second member of the first and second members to change the size of the gap through which the stopper penetrates. Therefore, the sewing machine can effectively limit the rotation of the shuttle stopper and the shuttle around the axis.

[0015] In the sewing machine of one aspect of the present invention, the driving unit may be a linear cylinder. In this case, the sewing machine can change the size of the gap of the stopper with a simple structure.

[0016] In the sewing machine of one aspect of the present invention, when the sewing is started, the control component may use the driving unit to move the second member arranged in the initial position in the direction in which the gap in the second direction becomes larger, thereby arranging the second member in the first sewing position. During the sewing process of the sewing machine, the upper thread sometimes gets hooked on the second abutment portion and untwisted. The gap expands when sewing starts, so it is difficult for the upper thread to get hooked on the second abutment portion during the sewing process of the sewing machine. Therefore, the sewing machine can suppress the untwisting of the upper thread.

[0017] In the sewing machine of one aspect of the present invention, it is also possible that, when the sewing is finished, the control member uses the driving unit to move the second member arranged at the first sewing position in the direction in which the gap becomes smaller in the second direction, so that the second member is arranged at the initial position. In this case, the sewing machine moves the second member to reduce the gap when the sewing is finished, so that the rotation of the shuttle stopper and the shuttle around the axis can be well restricted when no sewing is done.

[0018] Alternatively, a sewing machine according to one aspect of the present invention includes: a determining member that determines a travel direction from the position of the Nth needle toward the position of the N+1th needle in the sewing object, wherein N is a natural number; and a judging member that judges whether the travel direction determined by the determining member is within a predetermined range, and when the judging member judges that the travel direction is within the predetermined range, when the sewing of the N+1th needle is started, the control member moves the second member arranged at the first sewing position along the second direction, thereby arranging the second member at a second sewing position different from the first sewing position. In the sewing machine, when the travel direction during sewing is within the predetermined range, an over-wrap stitch is sometimes generated, thereby causing a poor tension balance between the upper thread and the lower thread. The over-wrap stitch is caused by the positional relationship between the upper thread and the lower thread. The sewing machine moves the second member from the first sewing position to the second sewing position, thereby changing the positional relationship between the upper thread and the lower thread. Thus, the sewing machine can suppress the generation of the over-wrap stitch.

[0019] In a sewing machine of one embodiment of the present invention, the second sewing position may be: the position of the second member after the second member arranged at the first sewing position is moved in the direction in which the gap in the second direction becomes smaller by the driving unit, and when the value of N+1 is less than a predetermined value M, the control unit does not arrange the second member arranged at the first sewing position at the second sewing position, wherein M is a natural number greater than 2. In the sewing machine, at the start of sewing, the surface thread sometimes hooks on the second abutment portion and untwists. When the number of stitches is less than a predetermined value, it is set that sewing starts and the second member does not move from the first sewing position to the second sewing position, so that the surface thread is difficult to hook on the second abutment portion at the start of sewing. Therefore, the sewing machine can suppress the untwisting of the surface thread at the start of sewing, and at the same time suppress the generation of winding stitches.

[0020] In a sewing machine according to one aspect of the present invention, the lower ends of the first abutting portion and the second abutting portion may be located above the shuttle tip, and the lower end of the second abutting portion may be located above the lower end of the first abutting portion. During sewing by the sewing machine, the upper thread may be hooked on the second abutting portion and untwisted. The lower end of the second abutting portion is located above the lower end of the first abutting portion, and thus the sewing machine can prevent the upper thread from being hooked on the second abutting portion and untwisting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a perspective view of the sewing machine 1 .

[0022] Figure 2 It is a perspective view of the head 6 and the shuttle mechanism 20.

[0023] Figure 3 yes Figure 2 The enlarged view of the part of the head 6 and the shuttle mechanism 20 is shown as being surrounded by the imaginary line III.

[0024] Figure 4 It is a perspective view of the shuttle mechanism 20.

[0025] Figure 5 It is a perspective view of the stopper 30.

[0026] Figure 6 It is a perspective view of the fixing member 31 .

[0027] Figure 7 This is a perspective view of the movable member 32 as viewed from the upper right front.

[0028] Figure 8 It is a perspective view of the movable member 32 as viewed from the lower right front.

[0029] Fig. 9 It is a right side view of the stopper 30 when the movable member 32 is located at the first position.

[0030] Fig.10 It is a top view of the stopper 30 and the shuttle 23 when the movable member 32 is located at the first position.

[0031] Fig.11 It is a right side view of the stopper 30 when the movable member 32 is located at the second position.

[0032] Fig.12 It is a top view of the stopper 30 and the shuttle 23 when the movable member 32 is located at the second position.

[0033] Fig.13 It is a top view of the stopper 30 and the shuttle 23 when the bottom thread R is sunk below the extending portion 32J.

[0034] Fig.14 1 and 2 are diagrams showing a perfect stitch region and an added stitch region when the movable member 32 is located at the first position.

[0035] Fig.15 1 and 2 are diagrams showing a perfect stitch region and an added stitch region when the movable member 32 is located at the second position.

[0036] Fig.16 It is a block diagram showing the electrical structure of the sewing machine 1.

[0037] Fig.17 The figure shows a workpiece 99 sewn based on a sewing pattern.

[0038] Fig.18 It is a flowchart of sewing process.

[0039] Fig.19 It is a flow chart of fixed-process processing.

[0040] Description of Reference Numerals

[0041] 1. Sewing machine; 20. Shuttle mechanism; 24. Shuttle case; 25. Shuttle; 26. Shuttle stop; 30. Stopper; 31. Fixed member; 32. Movable member; 34. Direct-acting cylinder; 37, 38. Abutment; 50. Control unit; 51. CPU; S. Gap. DETAILED DESCRIPTION

[0042] A sewing machine 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following description, left and right, front and back, and up and down are indicated by arrows in the drawings.

[0043] <Overview of sewing machine 1>

[0044] The sewing machine 1 is a sewing machine for sewing an article 99 (refer to Fig.17 ) is a door-type sewing machine for sewing. Figure 1 As shown, the sewing machine 1 includes a base 2, an operating unit 8, a conveying mechanism 4, a support 3L, a support 3R, a beam 5, a head 6, and a conveying mechanism 7 (see Figure 2 )、synchronizing mechanism 9 (refer to Figure 2 ) and shuttle mechanism 20.

[0045] The machine base 2 has a base 2A and a frame 2B. The base 2A is a box having a rectangular shape when viewed from above. A holding surface 2U extending horizontally is formed on the upper surface of the base 2A. An opening 2Q is formed in the base 2A, which opens on the holding surface 2U and extends in the left-right direction. A needle 11A described later passes through the opening 2Q. A holding plate 2P is provided at the front end of the base 2A. The holding plate 2P extends forward from the front end of the base 2A along the holding surface 2U.

[0046] An opening 2L is formed at the left end of the base 2A and is open to the holding surface 2U. The opening 2L extends in the front-to-back direction and is covered by the serpentine 2C. An opening 2R is formed at the right end of the base 2A and is open to the holding surface 2U. The opening 2R extends in the front-to-back direction and is covered by the serpentine 2D. A pair of guide rails (not shown) extending along the openings 2L and 2R and in the front-to-back direction are accommodated on the inner side of the base 2A. The serpentine 2C and the serpentine 2D extend and retract accordingly with the movement of the conveying mechanism 4 described later in the front-to-back direction. The frame 2B is a lattice-shaped structure that supports the base 2A from below.

[0047] The operation unit 8 is provided at the left front end of the base 2A. The operation unit 8 includes an input unit 8A and a display unit 8B. The input unit 8A receives an operation by an operator and sends an operation to the control unit 50 (see Fig.16 ) Input various instructions corresponding to the operator's operation. The display unit 8B is, for example, a liquid crystal display, and displays various images.

[0048] The conveying mechanism 4 includes a connecting portion 4L and a connecting portion 4R. The connecting portion 4L is connected to a guide rail extending along the opening 2L and protrudes above the holding surface 2U through the opening 2L. The connecting portion 4R is connected to a guide rail extending along the opening 2R and protrudes above the holding surface 2U through the opening 2R. The connecting portion 4L and the connecting portion 4R can be guided by a pair of guide rails and move in the front-rear direction. The conveying mechanism 4 is connected to the Y motor 73 (see FIG. 1 ) described later. Fig.16 ) and moves in the front-rear direction driven by the Y motor 73. The connecting portion 4L and the connecting portion 4R are connected to the holding mechanism 4A above the holding surface 2U.

[0049] The holding mechanism 4A has an upper frame 4U, a lower frame 4V, and cylinders 4C and 4D. The upper frame 4U and the lower frame 4V are rectangular frames when viewed from above. The upper frame 4U is arranged above the lower frame 4V and can move in the up-down direction. The upper frame 4U is connected to the cylinders 4C and 4D and moves in the up-down direction under the drive of the cylinders 4C and 4D. The upper frame 4U clamps the sewn object 99 placed on the lower frame 4V from above under the drive of the cylinders 4C and 4D (see Fig.17 ), so that the sewn object 99 is held by the holding mechanism 4A. The holding mechanism 4A moves the sewn object 99 and the conveying mechanism 4 in an integrated manner in the front-rear direction.

[0050] The support part 3L and the support part 3R are quadrangular prism-shaped boxes. The support part 3L extends upward from the base part 2A at a position between the left end of the base part 2A and the left end of the opening 2L. The main motor 71 (see FIG. 2 ) described later is stored inside the support part 3L. Fig.16 The support column 3R extends upward from the base 2A at a position between the right end of the base 2A and the right end of the opening 2R. An X motor 72 (see FIG. 1 ) described later is accommodated inside the support column 3R. Fig.16 ).

[0051] The beam 5 is installed between the support 3L and the support 3R. The beam 5 is a box that is long in the left-right direction and has a rectangular shape in the front view. An opening 5A extending in the left-right direction is formed on the front surface of the beam 5. The beam 5 has a bellows 5B, a pair of guide rails 5S (see FIG. Figure 2 ). The snake belly 5B covers the opening 5A and expands and contracts in accordance with the movement of the head 6 described later in the left and right directions. Figure 2 As shown, the pair of guide rails 5S are in the shape of bars extending in the left-right direction and are accommodated inside the beam portion 5. The pair of guide rails 5S are arranged at intervals from each other in the up-down direction and support the head 6 so as to be movable in the left-right direction.

[0052] The head 6 is arranged in front of the beam 5 (see Figure 1 ).like Figure 2 As shown, the head 6 has a housing 6A, a needle bar 11, a presser foot 12, a thread take-up lever 13, a thread clamp 14, a sub-thread clamp 15, and a drive mechanism 16. The housing 6A is box-shaped and accommodates the drive mechanism 16. The needle bar 11 is in the shape of a rod extending in the up-down direction and is supported by the drive mechanism 16 so as to be movable in the up-down direction. A needle 11A is installed at the lower end of the needle bar 11. The upper thread passes through the needle 11A.

[0053] The presser foot portion 12 has a through hole 12A (see FIG. 1A ) through which a needle 11A that moves vertically together with the needle bar 11 is inserted. Figure 3 ). The presser foot 12 presses the sewn object 99 from above. The thread take-up lever 13 lifts the upper thread in accordance with the vertical movement of the needle bar 11. The thread tensioner 14 adjusts the tension of the upper thread. The auxiliary thread tensioner 15 adjusts the tension of the upper thread together with the thread tensioner 14.

[0054] The driving mechanism 16 includes an upper shaft 17, a first support mechanism (not shown), a second support mechanism (not shown), a rotation knob 18, and a transmission mechanism 19. The upper shaft 17 is in the shape of a rod with an axis extending in the left-right direction, and is housed in the head 6. The right end of the upper shaft 17 protrudes to the right from the box 6A. The upper shaft 17 can rotate around the axis.

[0055] The first supporting mechanism and the second supporting mechanism are provided at the left end of the upper shaft 17. The first supporting mechanism supports the needle bar 11, and the second supporting mechanism supports the thread take-up lever 13. The first supporting mechanism and the needle bar 11 supported by the first supporting mechanism move in the up-down direction in accordance with the rotation of the upper shaft 17. The second supporting mechanism and the thread take-up lever 13 supported by the second supporting mechanism move in the up-down direction in accordance with the rotation of the upper shaft 17.

[0056] The rotating knob 18 is provided at the right end of the upper shaft 17 and is a circular plate whose axis extends in the left-right direction. The axis of the rotating knob 18 is coaxial with the axis of the upper shaft 17. The rotating knob 18 is located outside the housing 6A and can rotate around the axis under the operation of the operator. The transmission mechanism 19 transmits the drive of the spline shaft 9U described later to the upper shaft 17, so that the upper shaft 17 rotates around the axis.

[0057] The conveying mechanism 7 has an X motor 72 (see Fig.16 ), a transmission mechanism (not shown), and belts 7U and 7V. The transmission mechanism of the conveying mechanism 7 is housed inside the support column 3R, and transmits the drive of the X motor 72 to the belts 7U and 7V. The belt 7U is housed inside the beam portion 5. One end of the belt 7U is connected to the transmission mechanism, and the other end of the belt 7U is connected to the rear end of the box body 6A. The belt 7U transmits the drive of the X motor 72 to the head 6. The belt 7V is housed inside the base 2A. One end of the belt 7V is connected to the transmission mechanism, and the other end of the belt 7V is connected to the shuttle mechanism 20 described later. The belt 7V transmits the drive of the X motor 72 to the shuttle mechanism 20. The head 6 and the shuttle mechanism 20 move in the left-right direction under the drive of the X motor 72.

[0058] The synchronization mechanism 9 has a main motor 71 (see Fig.16 ), a transmission mechanism (not shown), and the spline shaft 9U and the spline shaft 9V. The transmission mechanism of the synchronization mechanism 9 is accommodated inside the support column 3L, and transmits the drive of the main motor 71 to the spline shaft 9U and the spline shaft 9V.

[0059] The spline shaft 9U and the spline shaft 9V are in the shape of a rod with an axis extending in the left-right direction, and a spline groove extending in the left-right direction is formed on the side. The spline shaft 9U is accommodated on the inner side of the beam portion 5. The spline shaft 9U can rotate around the axis. The spline shaft 9U rotates around the axis to transmit the drive of the main motor 71 to the transmission mechanism 19. The spline shaft 9V is accommodated on the inner side of the base 2A. The spline shaft 9V can rotate around the axis. The spline shaft 9V rotates around the axis to transmit the drive of the main motor 71 to the shuttle mechanism 20 described later.

[0060] <Shuttle mechanism 20>

[0061] The shuttle mechanism 20 is stored inside the base 2A (see Figure 1 ).like Figure 2 to Figure 4 As shown, the shuttle mechanism 20 has a housing 20A, a drive mechanism 21, a shuttle 23 and a stopper 30. Figure 2 As shown, the box body 20A is box-shaped and accommodates the drive mechanism 21 and the shuttle 23. The box body 20A is supported by a pair of guide rails 2S so as to be movable in the left-right direction. The pair of guide rails 2S are rod-shaped and extend in the left-right direction. The pair of guide rails 2S are accommodated inside the base 2A and are arranged at intervals from each other in the front-back direction.

[0062] like Figure 3As shown, an opening 20C and a pair of grooves 20D and 20E are formed in the box 20A. The opening 20C opens in the upper surface 20B of the box 20A along the up-down direction. The shuttle 23 described later is stored inside the box 20A through the opening 20C. The left end of the opening 20C is located between the left end of the box 20A and the center of the box 20A in the left-right direction. The right end of the opening 20C is located between the right end of the box 20A and the center of the box 20A in the left-right direction.

[0063] A pair of grooves 20D and 20E are formed by being recessed downward from the center of the upper surface 20B in the left-right direction. A pair of grooves 20D and 20E are located between the two ends of the opening 20C in the left-right direction. The depth of the pair of grooves 20D and 20E in the up-down direction is smaller than the depth of the opening 20C in the up-down direction. The pair of grooves 20D and 20E are arranged in the front-to-back direction. The groove 20D is located at the front end of the box body 20A and in front of the opening 20C. The groove 20E is located at the rear end of the box body 20A and behind the opening 20C.

[0064] like Figure 4 As shown, the drive mechanism 21 includes a lower shaft 22, a first transmission mechanism 21A, a second transmission mechanism (not shown), and a shuttle shaft (not shown). The lower shaft 22 is in the shape of a rod with an axis extending in the left-right direction and is accommodated in the box 20A. The right end of the lower shaft 22 protrudes to the right from the box 20A. The lower shaft 22 can rotate around the axis.

[0065] The first transmission mechanism 21A is connected to the right end of the lower shaft 22. The first transmission mechanism 21A transmits the drive of the spline shaft 9V to the lower shaft 22, so that the lower shaft 22 rotates around the axis. The second transmission mechanism is connected to the lower shaft 22 and the shuttle shaft. Although not shown in the figure, the shuttle shaft is in the shape of a rod extending in the up-down direction and is accommodated in the box 20A through the opening 20C. The shuttle shaft can rotate around the axis. The second transmission mechanism transmits the rotation of the lower shaft 22 around the axis to the shuttle shaft, so that the shuttle shaft rotates around the axis.

[0066] The shuttle 23 is located between the right end of the opening 20C and the center of the case 20A in the left-right direction. The shuttle 23 includes a bobbin case 24 and a shuttle 25. The bobbin case 24 is accommodated inside the case 20A via the opening 20C. The bobbin case 24 includes a base 24A and a shuttle tip 24C.

[0067] The base 24A is a cylinder whose axis extends in the vertical direction. An opening 24B is formed in the base 24A, which is open at the upper end of the base 24A and is circular in top view. The lower end of the base 24A is connected to the upper end of the shuttle shaft. The axis of the base 24A is consistent with the axis of the shuttle shaft. The bobbin case 24 connected to the shuttle shaft rotates around the axis of the base 24A under the drive of the main motor 71. When the sewing machine 1 sews the sewn object 99, the bobbin case 24 rotates clockwise when viewed from above. The clockwise rotation of the shuttle 23 when viewed from above is called forward rotation. The counterclockwise rotation of the shuttle 23 when viewed from above is called reverse rotation.

[0068] The shuttle tip 24C is in the shape of a rod extending from the outer peripheral end of the base 24A in the normal rotation direction of the bobbin case 24. The tip of the shuttle tip 24C is tapered. When the sewing machine 1 sews the workpiece 99, the shuttle tip 24C catches the loop of the upper thread passing through the needle 11A.

[0069] The shuttle 25 has a base 25A, a support shaft 25D, a pressing portion 25E, and a shuttle stopper 26. The base 25A is a cylinder whose axis extends in the vertical direction and is accommodated in the base 24A via the opening 24B. The axis of the base 25A is consistent with the axis of the base 24A. The base 25A can rotate relative to the bobbin case 24. A space 25B is formed in the base 25A, which is open at the upper end of the base 25A. The space 25B is a cylinder whose axis extends in the vertical direction. The bobbin 29 on which the bottom line R is wound is accommodated inside the space 25B.

[0070] The support shaft 25D is in the shape of a rod extending upward from the inner wall of the base 25A at the bottom of the predetermined space 25B. The axis of the support shaft 25D is consistent with the axis of the base 24A. In the up-down direction, the position of the upper end of the support shaft 25D is substantially the same as the position of the upper end of the base 25A. The pressing portion 25E is a plate extending forward from the upper end of the support shaft 25D. The pressing portion 25E presses the shuttle 29 accommodated in the space 25B from above to prevent the shuttle 29 from falling off the shuttle 25. A recess 25F is formed at the front end of the pressing portion 25E and at the end in the reverse direction of the bobbin case 24, which is recessed in the normal rotation direction of the bobbin case 24. The bottom line R wound around the bobbin 29 (refer to Fig.10 ) After being hooked into the recessed portion 25F, it extends toward the needle hole 33A described later.

[0071] The shuttle stopper 26 extends to the left from the outer peripheral end of the base 25A. More specifically, the shuttle stopper 26 is a plate that extends to the left above the base 24A after extending to the upper left from the upper left end of the base 25A. The left end of the shuttle stopper 26 is located to the left of the base 24A. The shuttle stopper 26 can rotate integrally with the shuttle 25. The shuttle 25 and the shuttle stopper 26 can rotate following the rotation of the bobbin case 24, and the rotation range is limited by the stopper 30 described later.

[0072] <Stop 30>

[0073] Reference Figure 3 to Figure 8 , the structure of the timer 30 is described. Figure 3 As shown, the stopper 30 is arranged at the center of the left-right direction of the box body 20A and at the upper left of the shuttle 23. Figure 5 As shown, the stopper 30 includes a fixed member 31 , a fixed member 36 , a movable member 32 , a pinhole member 33 , a linear cylinder 34 , and a connecting member 35 .

[0074] The fixing member 31 is provided inside the groove 20E (see Figure 3 ).like Figure 6 As shown, the fixing member 31 has a base portion 31A, a protruding portion 31B, and an extending portion 31C.

[0075] The base 31A is a plate that is rectangular in shape when viewed from above. The base 31A is provided with a threaded hole 31D, a through hole 31E, and a through hole 31F that penetrate the base 31A in the up-down direction. The threaded hole 31D is formed at a position closer to the right rear end than the center of the base 31A when viewed from above. The through hole 31E is formed at a position closer to the right front end than the center of the base 31A when viewed from above, and the through hole 31F is formed at a position closer to the left rear end than the center of the base 31A when viewed from above. The through holes 31E and 31F are stepped holes with a larger diameter on the upper side. The base 31A is secured by screws 43 (see Figure 4 ) is fixed to the bottom of the groove 20E. The head of the screw 43 is arranged inside the through hole 31E and the through hole 31F.

[0076] The protrusion 31B is in the shape of a rod extending forward from the right front end of the base 31A. The extension 31C is in the shape of a rod extending forward from the front end of the protrusion 31B. In the vertical direction, the position of the lower end of the extension 31C is substantially the same as the position of the lower end of the protrusion 31B. The upper end of the extension 31C is located above the upper end of the protrusion 31B. The front end of the extension 31C is a contact portion 37 extending in the vertical direction and having a rectangular shape in the front view.

[0077] like Figure 4 As shown, the fixing member 36 is a plate having a rectangular shape when viewed from above. A pair of through holes 36A are formed at the front end and rear end of the fixing member 36 in the upper and lower directions. In addition, a threaded hole (not shown) is formed at the front end of the fixing member 36 in the upper and lower directions. Figure 4 One of the pair of through holes 36A is shown in the figure. The through hole 36A is a stepped hole with a larger diameter on the upper side. The fixing member 36 is provided with a screw 44 (see also FIG. 4 ) which penetrates the pair of through holes 36A from above. Figure 5 , Fig.12 ) is fixed to the bottom of the groove 20E. The head of the screw 44 is arranged inside the through hole 36A.

[0078] like Figure 7 , Figure 8 As shown in the figure, the movable member 32 has a base 32A and an extension 32J. The base 32A is a plate extending in the front-rear direction and having a rectangular shape in a top view. The base 32A is formed with a screw hole 32C, a long hole 32D, a long hole 32E, a groove 32F and a through hole 32H. The screw hole 32C, the long hole 32D, the long hole 32E and the through hole 32H penetrate the base 32A in the up-down direction.

[0079] The screw hole 32C is formed at a rearward position relative to the center of the base 32A in the front-rear direction. The long hole 32D is formed at a frontward position relative to the center of the base 32A in the front-rear direction. The long hole 32E is formed between the screw hole 32C and the center of the base 32A in the front-rear direction. The long holes 32D and 32E extend in the front-rear direction.

[0080] The groove 32F is formed by being recessed upward from the lower surface 32B of the base 32A. The groove 32F extends from the right end of the base 32A in the left-right direction to a position between the left end of the base 32A and the center of the base 32A in the left-right direction. The through hole 32H is located inside the groove 32F in the front-back direction. In the front-back direction, the position of the front end of the through hole 32H is roughly the same as the position of the front end of the groove 32F. The rear end of the through hole 32H is located in front of the rear end of the groove 32F. The left end of the through hole 32H is located to the left of the left end of the groove 32F. The right end of the through hole 32H is located to the left of the right end of the groove 32F.

[0081] The extension portion 32J extends from the bottom 32G of the groove 32F (see Figure 8 ) extends downward from the right front end of the base 32A. The extension portion 32J is in the shape of a triangular prism extending in the front-to-back direction. The right surface of the extension portion 32J is inclined toward the lower left. In the left-right direction, the position of the left end of the extension portion 32J is approximately the same as the position of the right end of the through hole 32H. The lower end of the extension portion 32J is located above the lower surface 32B of the base 32A. The rear end of the extension portion 32J is an abutment portion 38 composed of a surface that is the bottom surface of a triangular prism extending in the front-to-back direction and is extended in the up-down direction. The abutment portion 38 is located between the two ends of the through hole 32H in the front-to-back direction.

[0082] like Figure 5 As shown, the pinhole member 33 has a base 33B, a protrusion 33C, an extension 33D and a cylindrical portion 33E. The base 33B is located below the through hole 32H. The base 33B is a plate extending in the front-to-back direction. The base 33B is fixed to the housing 20A. The protrusion 33C extends upward from the upper end of the base 33B. The protrusion 33C penetrates the through hole 32H. The upper end of the protrusion 33C is located below the upper end of the base 32A (see Figure 4 ).

[0083] The extension portion 33D is a plate extending from the upper right end of the protrusion 33C to the right. In the left-right direction, the length of the extension portion 33D is substantially the same as the length of the through hole 32H. The length of the protrusion 33C and the extension portion 33D in the front-to-back direction is smaller than the length of the through hole 32H in the left-to-right direction. That is, the extension portion 33D is accommodated inside the through hole 32H.

[0084] The cylindrical portion 33E is located at the center of the extension portion 33D in the front-back direction and the center in the left-right direction. The cylindrical portion 33E is a cylinder extending upward and downward from the extension portion 33D. The cylindrical portion 33E and the extension portion 33D are formed with a pinhole 33A that penetrates the cylindrical portion 33E and the extension portion 33D in the vertical direction. The pinhole 33A is located to the left of the abutment portions 37 and 38 (see Fig.10 ). The needle 11A moving in the up-down direction passes through the needle hole 33A.

[0085] The direct-acting cylinder 34 is disposed behind the movable member 32 (see Figure 4 ).like Figure 5 As shown, the direct-acting cylinder 34 is a well-known air cylinder, and has a housing 34A, a rod 34B, and an extension 34C. The housing 34A is box-shaped and accommodates a cylinder (not shown) that moves in the front-rear direction using air. A hole 34D is formed on the front surface of the housing 34A.

[0086] The rod 34B is fixed to the cylinder and is a rod protruding to the front of the box 34A through the hole 34D. The rod 34B can move in the front-to-back direction relative to the box 34A. The extension part 34C is in the shape of a rod extending forward from the front end of the rod 34B. A threaded hole (not shown) penetrating in the up-down direction is formed at a portion of the extension part 34C closer to the front end than the center in the front-to-back direction.

[0087] like Figure 5 As shown in FIG. 1 , the connecting member 35 is a plate extending in the front-rear direction and is located between the movable member 32 and the extension portion 34C in the vertical direction. Holes (not shown) penetrating the connecting member 35 in the vertical direction are formed at a portion closer to the front end than the center in the front-rear direction of the connecting member 35 and a portion closer to the rear end than the center in the front-rear direction of the connecting member 35, respectively.

[0088] The stepped screw 41A passes through the hole on the front end side of the connecting member 35 from below. The threaded portion of the stepped screw 41A protrudes upward from the connecting member 35 and is threadedly engaged with the threaded hole 32C of the movable member 32. The connecting member 35 can rotate relative to the movable member 32 around the stepped screw 41A. The stepped screw 41B passes through the hole on the rear end side of the connecting member 35 from above. The threaded portion of the stepped screw 41B protrudes downward from the connecting member 35 and is threadedly engaged with the threaded hole of the extension 34C. The connecting member 35 can rotate relative to the extension 34C around the stepped screw 41B. The movable member 32 is connected to the direct-acting cylinder 34 by means of the connecting member 35.

[0089] The movable member 32 is located above the fixed member 31 and the fixed member 36. The stepped screw 42A passes through the long hole 32D from above. The threaded portion of the stepped screw 42A protrudes downward relative to the lower surface 32B and is threadedly engaged with the threaded hole of the fixed member 36. The stepped screw 42B passes through the long hole 32E from above. The threaded portion of the stepped screw 42B protrudes downward relative to the lower surface 32B and is threadedly engaged with the threaded hole 31D of the fixed member 31 (see FIG. 1 ). Figure 6 The position of the upper end of the abutment portion 37 is substantially the same as the position of the bottom 32G of the groove 32F in the vertical direction (see Fig. 9 ).

[0090] like Figure 3 As shown, in the stopper 30, the abutment portion 37 of the fixed member 31 and the abutment portion 38 of the movable member 32 are opposite in the front-rear direction. A gap S is formed between the abutment portion 37 and the abutment portion 38. The shuttle stopper 26 of the shuttle 25 passes through the gap S. When the shuttle 25 rotates forward, the shuttle stopper 26 abuts against the abutment portion 37, limiting the forward rotation of the shuttle 25. When the shuttle 25 rotates reversely, the shuttle stopper 26 abuts against the abutment portion 38, limiting the reverse rotation of the shuttle 25. That is, the rotation range of the shuttle 25 is determined based on the size of the gap S.

[0091] like Figure 4 As shown in FIG. 1 , the lower end of the contact portion 37 and the lower end of the contact portion 38 are located above the shuttle tip 24C. Therefore, the contact portion 37 and the contact portion 38 do not hinder the rotation of the bobbin case 24. The lower end of the contact portion 38 is located above the lower end of the contact portion 37 (see FIG. 1 ). Fig. 9 ).

[0092] <Movement of the movable member 32>

[0093] The movable member 32 is driven by the direct-acting cylinder 34 and guided by the stepped screws 42A and 42B to move in the front-rear direction. Fig. 9 , Fig.10 The first position shown and Fig.11 , Fig.12 The second position shown moves.

[0094] like Fig. 9 As shown, when the movable member 32 is located at the first position, the position of the contact portion 38 is located forward of the axis C of the pinhole 33A in the front-rear direction. Fig.10 As shown in FIG. 1 , the bobbin thread R extending from the recess 25F extends straightly to the left rearward toward the needle hole 33A. The bobbin thread R passes through the needle hole 33A from below. The contact portion 38 is separated from the bobbin thread R toward the front.

[0095] like Fig.11As shown, when the movable member 32 is located at the second position, the position of the abutment portion 38 is substantially the same as the position of the axis C of the needle hole 33A in the front-rear direction. Fig.12 As shown, the movable member 32 located at the second position is located at a position greater than the movable member 32 located at the first position (refer to Fig.10 ) to the rear. Therefore, the size of the gap S when the movable member 32 is in the second position is smaller than the size of the gap S when the movable member 32 is in the first position. The rotation range of the shuttle 25 and the shuttle stopper 26 around the axis when the movable member 32 is in the second position is smaller than the rotation range around the axis when the movable member 32 is in the first position.

[0096] The bobbin thread R extending from the recess 25F extends leftwardly toward the contact portion 38, then changes direction leftward along the contact portion 38 and extends toward the needle hole 33A. The bobbin thread R passes through the needle hole 33A from below. When the sewing machine 1 is not sewing, the movable member 32 is located at the second position.

[0097] When the movable member 32 moves from the second position to the first position, the abutment portion 38 separates from the bottom line R forward. On the other hand, when the movable member 32 moves from the first position to the second position, the abutment portion 38 abuts against the bottom line R and pushes the bottom line R backward. In this way, the stopper 30 switches the movable member 32 between the first position and the second position, thereby changing the path of the bottom line R toward the needle hole 33A and changing the position of the bottom line R relative to the surface thread passing through the needle 11A.

[0098] When the sewing machine 1 is sewing, the appearance quality of the stitch changes according to the direction of travel from the position of the Nth needle (N is a natural number) toward the position of the N+1th needle. The reason is that the positional relationship between the upper thread and the lower thread R changes according to the direction of travel. The method of deriving the direction of travel will be described later. In the sewing machine 1, the direction of travel includes a direction that becomes a perfect stitch and a direction that becomes a winding stitch. The perfect stitch is a stitch formed by the upper thread and the lower thread R being entangled in a state of being equal to each other. When a perfect stitch is formed, the thread is well wound. The winding stitch is a stitch formed by entanglement in a state where the tension of the upper thread is weakened and the balance of tension with the lower thread R is broken. When a winding stitch is formed, the stitch is formed in a spiral drawn by only the upper thread, and therefore, the stitch quality is reduced.

[0099] like Fig.14 , Fig.15 As shown, when the position of the Nth needle is set as the base point O, the travel direction from the base point O to the position of the N+1th needle is within the range of 0° to 360°. The travel direction to the rear in the sewing machine 1 is 0° (360°), the travel direction to the right is 90°, the travel direction to the front is 180°, and the travel direction to the left is 270°. Fig.14 , Fig.15 In the figure, the area in the direction of travel of the perfect stitch is indicated by white filling, and the area in the direction of travel of the winding stitch is indicated by black filling. Hereinafter, the area in the direction of travel of the perfect stitch is referred to as the perfect stitch area. The area in the direction of travel of the winding stitch is referred to as the winding stitch area.

[0100] In the sewing machine 1, when the movable member 32 is located at the first position (refer to Fig.14 ) and when the movable member 32 is in the second position (refer to Fig.15 ), the added stitch area is different. The reason is that the positional relationship between the upper thread and the lower thread R changes due to the abutment portion 38 of the movable member 32. In the sewing machine 1, the added stitch area when the movable member 32 is in the second position does not overlap with the added stitch area when the movable member 32 is in the first position. Therefore, the sewing machine 1 can suppress the formation of the added stitch by switching the movable member 32 between the first position and the second position. Hereinafter, the added stitch area when the movable member 32 is in the first position is referred to as the added stitch area at the first position.

[0101] The tension of the upper thread at the start of sewing of the sewing machine 1 is smaller than the tension of the upper thread after the start of sewing. In the sewing machine 1, sewing starts from the first stitch to the Mth stitch. M is a natural number greater than 2 and is stored in the ROM 52 described later. When the movable member 32 is located at the second position and sewing starts, the bottom thread R sometimes sneaks under the extension portion 32J (see Fig.13 At this time, there is a possibility that the loop of the upper thread is caught on the contact portion 38, resulting in sewing defects such as untwisting of the upper thread.

[0102] When the sewing machine 1 starts sewing, the movable member 32 is moved from the second position to the first position. The sewing machine 1 does not move the movable member 32 to the second position during the start of sewing. When the movable member 32 is located at the first position, the contact portion 38 is located in front of the bottom thread R extending straight from the recess 25F to the needle hole 33A (see Fig.10 ). Therefore, the sewing machine 1 can prevent the bottom thread R from entering under the extending portion 32J at the start of sewing, thereby preventing sewing defects from occurring.

[0103] When the sewing of the sewing machine 1 is finished, it is determined whether the traveling direction from the sewn Nth needle toward the N+1th needle is in the added stitch area at the first position. When the traveling direction is in the added stitch area at the first position, the sewing machine 1 moves the movable member 32 from the first position to the second position. Thereafter, when the traveling direction is in the perfect stitch area at the first position, the sewing machine 1 moves the movable member 32 from the second position to the first position. When the sewing machine 1 finishes sewing, the movable member 32 is arranged at the second position.

[0104] <Electrical configuration of sewing machine 1>

[0105] like Fig.16 As shown, the control unit 50 of the sewing machine 1 includes a CPU 51, a ROM 52, a RAM 53, a storage device 54, an input / output interface (I / O) 55, and drive circuits 61 to 66. The CPU 51 comprehensively controls the operation of the sewing machine 1.

[0106] The ROM 52 stores programs for executing various processes such as sewing processes described later. The RAM 53 temporarily stores various information generated when executing various processes. The storage device 54 is non-volatile and stores the perfect stitch area and the winding stitch area (see Fig.14 )wait.

[0107] The drive circuits 61 to 66, the encoders 71A to 73A, and the input unit 8A are connected to the I / O 55. The drive circuit 61 is connected to the main motor 71, and drives the main motor 71 based on the control command of the CPU 51. The drive circuit 62 is connected to the X motor 72, and drives the X motor 72 based on the control command of the CPU 51. The drive circuit 63 is connected to the Y motor 73, and drives the Y motor 73 based on the control command of the CPU 51. The drive circuit 64 is connected to the direct-acting cylinder 34, and drives the direct-acting cylinder 34 based on the control command of the CPU 51. The drive circuit 65 is connected to the cylinder 4C and the cylinder 4D, and drives the cylinder 4C and the cylinder 4D based on the control command of the CPU 51. The drive circuit 66 is connected to the display unit 8B, and displays various information on the display unit 8B based on the control command of the CPU 51.

[0108] The encoder 71A detects the rotation direction, rotation position, and rotation speed of the output shaft of the main motor 71, and outputs the detection result to the I / O 55. The detection result of the encoder 71A indicates the rotation direction, rotation position, and rotation speed of the upper shaft 17 and the lower shaft 22 driven by the main motor 71. The encoder 72A detects the rotation direction, rotation position, and rotation speed of the output shaft of the X motor 72, and outputs the detection result to the I / O 55. The detection result of the encoder 72A indicates the moving direction, left-right position, and moving speed of the needle bar 11 and the shuttle 23. The encoder 73A detects the rotation direction, rotation position, and rotation speed of the output shaft of the Y motor 73, and outputs the detection result to the I / O 55. The detection result of the encoder 73A indicates the moving direction, front-back position, and moving speed of the holding mechanism 4A. The input unit 8A receives the operation of the operator and outputs various instructions to the I / O 55.

[0109] <Sewing direction>

[0110] Reference Fig.17, describing the sewing pattern of the sewing machine 1. The sewing machine 1 sews the object 99 based on the sewing pattern. A plurality of sewing patterns are stored in the storage device 54. For example Fig.17 The sewing pattern shown includes coordinate information of a plurality of needle drop points P1 to P4. Needle drop point P1 is the position where the first needle is sewn. Needle drop point P2 is the position where the second needle is sewn. Needle drop point P3 is the position where the third needle is sewn. Needle drop point P4 is the position where the fourth needle is sewn.

[0111] The coordinate information of needle drop points P1 to P4 is stored by combining the left-right direction position and the front-back direction position of the needle bar 11. When moving from needle drop point P1 to needle drop point P2, for example, the CPU 51 calculates the travel direction based on the coordinate information of needle drop points P1 and P2. The storage device 54 stores the perfect stitch area and the winding stitch area when the movable member 32 is in the first position (refer to Fig.14 ). When the movable member 32 is located at the first position and the calculated travel direction is included in the winding stitch area, the CPU 51 moves the movable member 32 to the second position under the action of the direct acting cylinder 34.

[0112] <Sewing Process>

[0113] Reference Fig.18 , which explains the sewing process executed by the CPU 51 of the control unit 50. When the operator inputs the execution instruction of the sewing process through the input unit 8A, the CPU 51 executes the program called from the ROM 52 to start the sewing process. The execution instruction of the sewing process includes information specifying any of the sewing patterns stored in the storage device 54. When the sewing process starts, the movable member 32 is located at the second position (refer to Fig.11 , Fig.12 ). The sewn object 99 is held by the holding mechanism 4A.

[0114] When the sewing process starts, the CPU 51 moves the movable member 32 located at the second position forward under the action of the direct-acting cylinder 34, and arranges the movable member 32 at the first position (see Fig. 9 , Fig.10 )(S1). As a result, the size of the gap S increases. The contact portion 38 separates from the bottom line R forward.

[0115] The CPU 51 sets the value of the variable N indicating the number of stitches to 1 (S2). The CPU 51 obtains the sewing pattern specified by the execution instruction of the sewing process from the storage device 54 (S3). The CPU 51 moves the needle bar 11 and the shuttle 23 to the coordinates of the first stitch based on the sewing pattern obtained in S3 (S4). Driven by the X motor 72, the head 6 and the shuttle mechanism 20 move in the left-right direction relative to the sewn object 99, and driven by the Y motor 73, the sewn object 99 placed on the holding mechanism 4A moves in the front-back direction relative to the head 6 and the shuttle mechanism 20.

[0116] CPU51 drives main motor 71 to rotate upper shaft 17 and lower shaft 22, thereby starting sewing (S5). Needle bar 11 reciprocates in the vertical direction, and bobbin case 24 rotates forward. The shuttle tip 24C catches the loop of the upper thread and winds it with the lower thread R, thereby forming a stitch on the sewn object 99.

[0117] The CPU 51 determines whether a needle trace is formed on the sewn object 99 (S6). The CPU 51 performs the determination of S6 based on the detection result of the encoder 71A. When the CPU 51 determines that a needle trace is not formed (S6: No), the process returns to S6.

[0118] When the CPU 51 determines that the stitch is formed (S6: Yes), it determines whether sewing is completed at all the needle insertion points included in the sewing pattern (S7). When the CPU 51 determines that sewing is not completed (S7: No), it executes the fixed-length processing (S8).

[0119] Reference Fig.19 , for sewing processing (refer to Fig.18 ) will be described below. The fixed-range processing is a processing for moving the movable member 32 to either the first position or the second position.

[0120] If the fixed-range processing starts, the CPU 51 determines whether the value of N+1 is less than the predetermined value M (S11). When the value of N+1 is less than the predetermined value M (S11: Yes), the CPU 51 sets the sewing of the N+1th needle as the start of sewing, and returns the processing to the sewing processing. Fig.18 ) the movable member 32 arranged in the first position does not move and remains in the first position.

[0121] When the value of N+1 is greater than the predetermined value M (S11: No), the CPU 51 assumes that the sewing of the N+1th needle is not the start of sewing, and according to S3 (refer to Fig.18 ) obtains the coordinates of the N+1th stitch from the sewing pattern obtained in (S12). The CPU 51 calculates the direction of travel toward the N+1th stitch based on the coordinates of the Nth stitch and the coordinates of the N+1th stitch (S13).

[0122] The CPU 51 determines whether the traveling direction calculated in S13 is within the winding stitch area at the first position (S14). When the traveling direction is within the winding stitch area at the first position (S14: Yes), the CPU 51 determines whether the position of the movable member 32 is at the first position (S15). When the position of the movable member 32 is at the first position, if the sewing of the N+1th needle is performed directly, there is a possibility of forming a winding stitch. When the CPU 51 determines that the position of the movable member 32 is at the first position (S15: Yes), the movable member 32 at the first position is moved backward under the action of the direct-acting cylinder 34, and the movable member 32 is arranged at the second position (S16), and the processing returns to the sewing processing. As a result, the size of the gap S becomes smaller. In addition, the processing of S16 is executed while the needle 11A is located at a position above the needle hole 33A. When the CPU 51 determines that the movable member 32 is at the second position (S15: No), the processing returns to the sewing processing.

[0123] When the CPU 51 is not in the winding stitch area at the first position in the traveling direction (S14: No), it determines whether the position of the movable member 32 is at the first position (S17). When the position of the movable member 32 is at the first position, if the N+1th needle is sewn directly, a perfect stitch is formed. When the CPU 51 determines that the position of the movable member 32 is at the first position (S17: Yes), the CPU 51 returns the processing to the sewing processing. When the CPU 51 determines that the movable member 32 is at the second position (S17: No), the movable member 32 at the second position is moved forward by the direct-acting cylinder 34, and the movable member 32 is arranged at the first position (S18), and the processing returns to the sewing processing. In addition, the processing of S18 is performed while the needle 11A is at a position above the needle hole 33A.

[0124] like Fig.18 As shown, if the CPU 51 executes the fixed-range processing (S8), the value of the variable N is increased by 1 (S9). Based on the sewing pattern obtained in S3, the CPU 51 moves the needle bar 11 and the shuttle 23 to the coordinates of the Nth stitch (S10). In the processing of S10, the head 6 and the shuttle mechanism 20 and the sewn object 99 are moved relative to each other in the left-right direction and the front-back direction under the drive of the X motor 72 and the Y motor 73, as in the processing of S4. The CPU 51 repeats the processing of S6 to S10 until the sewing is completed.

[0125] When the CPU 51 determines that sewing is completed at all the needle drop points included in the sewing pattern (S7: Yes), the CPU 51 stops driving the main motor 71, the X motor 72, and the Y motor 73, and stops sewing (S21). The CPU 51 moves the movable member 32 to the second position under the action of the direct-acting cylinder 34 (S22). The CPU 51 ends the sewing process.

[0126] When sewing is not being performed, if the operator rotates the rotary knob 18, the upper shaft 17 connected to the rotary knob 18 and the lower shaft 22 to which the power is transmitted by the synchronization mechanism 9 also rotate. Due to the rotation of the lower shaft 22, the bobbin case 24 rotates around the axis extending in the vertical direction. The rotation of the shuttle 25 is limited by the abutment portion 37 and the abutment portion 38. When the shuttle 25 rotates forward, the shuttle stopper 26 abuts against the abutment portion 37, limiting the forward rotation of the shuttle 25. When the shuttle 25 rotates reversely, the shuttle stopper 26 abuts against the abutment portion 38, limiting the reverse rotation of the shuttle 25.

[0127] <Functions and Effects of the Present Embodiment>

[0128] As described above, the shuttle mechanism 20 includes a housing 20A, a bobbin case 24, a shuttle 25, and a stopper 30. The stopper 30 includes a fixed member 31 including a contact portion 37 and a movable member 32 including a contact portion 38. The contact portion 37 and the contact portion 38 are opposite to each other in the front-to-back direction. The shuttle stopper 26 extending from the base 25A of the shuttle 25 passes through the gap S formed between the contact portion 37 and the contact portion 38. The contact portion 37 limits the forward rotation of the shuttle 25 by contacting with the shuttle stopper 26. The contact portion 38 limits the reverse rotation of the shuttle 25 by contacting with the shuttle stopper 26. The fixed member 31 is fixed relative to the groove 20E of the housing 20A. The movable member 32 can move in the front-to-back direction. Thus, the sewing machine 1 can change the size of the gap S. The sewing machine 1 can suppress the upper thread from being caught on the contact portion 38 by changing the size of the gap S, and can sufficiently restrict the rotation of the shuttle 25 .

[0129] In the sewing machine 1, the movable member 32 is connected to the direct-acting cylinder 34. The CPU 51 of the control unit 50 moves the movable member 32 in the front-rear direction under the action of the direct-acting cylinder 34. Thus, the sewing machine 1 can easily move the movable member 32 in the front-rear direction compared to the operator moving the movable member 32 in the front-rear direction by manual operation.

[0130] In the sewing machine 1, the direct-acting cylinder 34 is connected to the movable member 32 of the fixed member 31 and the movable member 32. When the sewing machine 1 is sewing, the bobbin case 24 rotates forward, and the shuttle 25 accommodated in the bobbin case 24 is also easy to rotate forward. When the shuttle 25 rotates forward, it is easy to abut against the abutment portion 37 of the abutment portion 37 of the fixed member 31 and the abutment portion 38 of the movable member 32. In the sewing machine 1, the movable member 32 having the abutment portion 38 is moved under the action of the direct-acting cylinder 34, so that the shuttle 25 can be effectively restricted from rotating when the sewing machine 1 is sewing.

[0131] In the sewing machine 1, the movable member 32 is moved by the drive of the linear cylinder 34. In this case, the sewing machine 1 can change the size of the gap S with a simple structure.

[0132] Before sewing is started by the sewing process, the movable member 32 is located at the second position. When sewing is started by the sewing process, the CPU 51 moves the movable member 32 located at the second position forward under the action of the direct-acting cylinder 34, and arranges the movable member 32 at the first position (S1). The size of the gap S becomes larger. When the sewing machine 1 is sewing, the bottom thread R sometimes sneaks under the extension portion 32J (refer to Fig.13 ), the upper thread loop is hooked on the contact portion 38 and the upper thread is untwisted. When sewing starts, the sewing machine 1 moves the movable member 32 to increase the size of the gap S. Thus, the upper thread loop can be prevented from being hooked on the contact portion 38, and the sewing machine 1 can prevent the upper thread from being untwisted.

[0133] When the sewing process of the sewing process is finished, the CPU 51 uses the direct-acting cylinder 34 to arrange the movable member 32 in the second position (S22). When sewing is not being performed, if the operator rotates the rotary knob 18, the bobbin case 24 rotates around the axis extending in the vertical direction. The rotation of the shuttle 25 is limited by the abutment portion 37 and the abutment portion 38. Regarding the size of the gap S, the size of the gap S when the movable member 32 is in the second position is smaller than the size of the gap S when the movable member 32 is in the first position. Therefore, the sewing machine 1 can effectively limit the rotation of the shuttle 25 when sewing is not being performed.

[0134] CPU51 calculates the direction of travel from the position of the Nth needle toward the position of the N+1th needle (S13). CPU51 determines whether the calculated direction of travel is within the added stitch area at the first position (S14). When the direction of travel is within the added stitch area at the first position, CPU51 moves the movable member 32 located at the first position backward under the action of the direct-acting cylinder 34, and configures the movable member 32 at the second position. The size of the gap S becomes smaller. In this case, the bottom line R is pushed out by the abutment portion 38, changing the path toward the needle hole 33A. As a result, the direction of travel changes from the added stitch area where the movable member 32 is located at the first position (refer to Fig.14) is switched to the perfect stitch region where the movable member 32 is located in the second position (refer to Fig.15 ). Thus, the sewing machine 1 can form a perfect stitch and can suppress the formation of an overwrapped stitch.

[0135] CPU51 determines whether the value of N+1 is greater than a predetermined value M (S11). When the value of N+1 is less than a predetermined value M, CPU51 sets the sewing of the N+1th needle as the start of sewing, and does not move the movable member 32 to the second position. At the start of sewing, the tension of the surface thread is relatively small, so the bottom thread R sometimes sneaks under the extension portion 32J. At this time, there is a possibility that the coil of the surface thread is hooked on the abutment portion 38 and the surface thread is untwisted. When the number of stitches of the sewing machine 1 is less than the predetermined value, the sewing start is set, and the movable member 32 is not shifted from the first position to the second position. As a result, it is difficult for the surface thread to be hooked on the second abutment portion at the start of sewing, and the sewing machine 1 can suppress the untwisting of the surface thread at the start of sewing, and can suppress the formation of the winding stitch.

[0136] The lower ends of the abutting portions 37 and 38 are located above the shuttle tip 24C. The lower end of the abutting portion 38 is located above the lower end of the abutting portion 37. When the sewing machine 1 is sewing, the loop of the upper thread may be caught on the abutting portion 38 and the upper thread may be untwisted. The lower end of the abutting portion 38 is located above the lower end of the abutting portion 37, so the sewing machine 1 can prevent the loop of the upper thread from being caught on the abutting portion 38 and the upper thread from being untwisted.

[0137] <Modification>

[0138] The present invention can be modified in various ways based on the above-mentioned embodiment. The various modifications described below can be combined as long as no contradiction occurs. The type of sewing machine 1 is not limited to a gate-type sewing machine, and can be appropriately modified into various industrial sewing machines, household sewing machines, etc.

[0139] In the above embodiment, the fixed member 31 having the contact portion 37 is fixed to the box body 20A, and the movable member 32 having the contact portion 38 is movable in the front-rear direction. In contrast, the fixed member 31 may be movable in the front-rear direction, and the movable member 32 may be fixed to the box body 20A. Alternatively, either the fixed member 31 or the movable member 32 may be movable in the front-rear direction.

[0140] In the above embodiment, the movable member 32 is guided by the stepped screws 42A and 42B to move in the front-rear direction. In contrast, in the sewing machine 1, the size of the gap S can be changed by the movement of the movable member 32 in the front-rear direction. For example, the movable member 32 may move in an arc shape extending in the front-rear direction. For example, the movable member 32 may reciprocate along an imaginary line extending to the left front and right rear.

[0141] The stopper 30 may not include the direct-acting cylinder 34. In this case, the operator moves the movable member 32 provided in a manner movable in the front-rear direction to change the size of the gap S. The CPU 51 of the control unit 50 may not control the drive of the direct-acting cylinder 34. In this case, the drive of the direct-acting cylinder 34 may also be controlled by the operator pressing a button or releasing the pressing.

[0142] In the above embodiment, the direct-acting cylinder 34 is connected to the movable member 32, but the present invention is not limited thereto. Alternatively, the direct-acting cylinder 34 can be connected to the fixed member 31 and moved to replace the movable member 32, and conversely fix the movable member 32 to the housing 20A. Alternatively, the direct-acting cylinder 34 is connected to the movable member 32, and a direct-acting cylinder different from the direct-acting cylinder 34 is connected to the fixed member 31.

[0143] In the above-mentioned embodiment, the movable member 32 is moved in the front-to-back direction by using a direct-acting cylinder 34 as an air cylinder. In contrast, the direct-acting cylinder 34 may also be, for example, a hydraulic cylinder, an electromagnetic cylinder, a ball screw, etc. The direct-acting cylinder 34 may also move the rod 34B in directions other than the front-to-back direction. Alternatively, in the case of, for example, moving the rod 34B in the left-right direction, a connecting rod mechanism or the like may be used to convert the power in the left-to-right direction generated by the direct-acting cylinder 34 into power for linear movement in the front-to-back direction. The movable member 32 may also be moved by using a drive of a rotary actuator such as a servo motor instead of the direct-acting cylinder 34. In this case, a connecting rod mechanism, a rack-and-pinion mechanism, a timing belt, etc. may also be used to convert the power of the rotational motion generated by the rotary actuator into power for linear movement in the front-to-back direction.

[0144] The sewing process may also be appropriately changed. In the sewing process, the process of S1 may also be omitted. In this case, at the beginning of sewing, the movable member 32 is located at the second position. In the sewing process, the process of S22 may also be omitted. In this case, after the sewing process is finished, the movable member 32 is located at the position configured when sewing was last performed.

[0145] In the sewing process, the process of S8 may be omitted. In this case, the movable member 32 does not move in the front-to-back direction corresponding to the traveling direction of sewing during the sewing process performed by the sewing machine 1. In the fixed-range process, the process of S11 may be omitted. In this case, the movable member 32 moves in the front-to-back direction corresponding to the traveling direction from the first needle toward the second needle.

[0146] In the above embodiment, the travel direction from the position of the Nth needle toward the position of the N+1th needle is calculated based on the sewing pattern stored in the storage device 54. In contrast, the CPU 51 may determine the travel direction using a sensor that detects the travel direction of the needle bar 11. The sensor that detects the travel direction is, for example, the encoder 72A or the encoder 73A.

[0147] In the above embodiment, when the movable member 32 is in the first position, the movable member 32 is switched to the second position based on whether the traveling direction is in the winding stitch area at the first position. In contrast, when the movable member 32 is in the second position, the movable member 32 is switched to the first position based on whether the traveling direction is in the winding stitch area at the second position.

[0148] In the above embodiment, the control is performed by switching the movable member 32 so as to avoid the winding stitch in all the sewing travel directions, but it is not limited to this. For example, even if the movable member 32 is switched, there will be a mode of travel direction that becomes the winding stitch area. In the case where the sewing in the remaining travel direction that becomes the winding stitch area is not included in the sewing data or the sewing is short, this mode can be fully utilized. Even if the winding stitch area is reduced by only changing the position of the movable member 32, it can be effectively and flexibly used to maintain the sewing quality.

[0149] In the above embodiment, the sewing machine 1 uses the direct-acting cylinder 34 to switch and configure the movable member 32 to the first position and the second position. In contrast, the sewing machine 1 may also configure the movable member 32 at one or more positions different from the first position and the second position. In the above embodiment, when the sewing machine 1 is not sewing and the traveling direction is in the winding stitch area at the first position during sewing, the movable member 32 is located at the second position. In contrast, the movable member 32 may be configured at different positions when the sewing machine 1 is not sewing and the traveling direction is in the winding stitch area at the first position during sewing.

[0150] The position of the movable member 32 may be changed to the first position or the second position according to sewing conditions such as the type of the sewn object 99 and the type of yarn. In this case, the control unit 50 of the sewing machine 1 may read the sewing conditions to automatically set the first position and the second position of the appropriate movable member 32. Alternatively, the operator may be able to appropriately set and change the first position and the second position of the movable member 32 by means of the operating unit 8 or the like.

[0151] The lower end of the contact portion 38 may not be located above the lower end of the contact portion 37. For example, the lower end of the contact portion 38 may be located below the lower end of the contact portion 37.

[0152] Other variations are described. The structure of the shuttle mechanism 20 may also be appropriately changed. The shuttle mechanism 20 may not have the fixing member 36. In this case, the stepped screw 42A may also be threadedly coupled to the housing 20A. Alternatively, a protrusion may be formed that protrudes upward from the bottom of the groove 20D or the groove 20E, and the protrusion guides the movement of the movable member 32 in the front-to-back direction. In this case, the shuttle mechanism 20 may not have the stepped screw 42A or the stepped screw 42B. The shuttle 25 may not have the pressing portion 25E. The pinhole member 33 may also be located above the movable member 32. The direct-acting cylinder 34 may also be connected to the movable member 32 without the aid of the connecting member 35.

[0153] The contact portion 37 and the contact portion 38 are not limited to a flat surface, but may be a curved surface, a concave-convex surface, an inclined surface, a protrusion, etc., as long as they can limit the forward or reverse rotation of the shuttle 25 by contacting with the shuttle stopper 26.

[0154] The control unit 50 is not limited to being provided in the sewing machine 1, and may be provided separately from the sewing machine 1. For example, the control unit 50 may be a device (PC, dedicated machine, etc.) connected to the sewing machine 1. For example, a microcomputer, ASIC (Application Specific Integrated Circuits), FPGA (Field Programmable Gate Array), etc. may be used instead of the CPU 51. Sewing processing may be distributed processing or may be processed by combining the CPU 51 and the ASIC.

[0155] The non-temporary storage medium such as ROM52 and storage device 54 may be a storage medium that can retain information in advance regardless of the period of storing the information. The non-temporary storage medium may not include a temporary storage medium (for example, a transmitted signal). Various programs, sewing patterns, etc. may also be downloaded from a server connected to the network (not shown) (that is, sent as a transmission signal) and stored in ROM52 or storage device 54. In this case, the program may be stored in a non-temporary storage medium such as a HDD possessed by the server.

[0156] <Other>

[0157] The left-right direction is an example of the "first direction" of the present invention. The fixed member 31 is an example of the "first member" of the present invention. The movable member 32 is an example of the "second member" of the present invention. The abutment portion 37 is an example of the "first abutment portion" of the present invention. The abutment portion 38 is an example of the "second abutment portion" of the present invention. The front-back direction is an example of the "second direction" of the present invention. The direct-acting cylinder 34 is an example of the "driving portion" of the present invention. The processing of S1, S16, S18, and S22 executed by the CPU 51 is an example of the "control component" of the present invention. The second position is an example of the "initial position" and "second sewing position" of the present invention. The first position is an example of the "first sewing position" of the present invention. The processing of S13 is an example of the "determination component" of the present invention. The winding stitch area at the first position is an example of the "predetermined range" of the present invention. The processing of S14 is an example of the "determination component" of the present invention.

Claims

1. A sewing machine, characterized in that: It has a shuttle mechanism that captures the upper thread that passes through the needle and entangles it with the lower thread. The shuttle mechanism has: A bobbin case, comprising a bobbin tip capable of catching the upper thread, and capable of rotating about an axis extending in an up-down direction; A shuttle that receives the bottom thread and is rotatable about the axis relative to the bobbin case at the inner side of the bobbin case; A shuttle stopper connected to the outer periphery of the shuttle, capable of rotating integrally with the shuttle about the axis, and extending in a predetermined first direction in a radial direction centered on the axis; as well as A timer having a first component and a second component, The first member has a first abutment portion capable of abutting against the shuttle stopper portion that is rotating in a normal direction in the rotation about the axis. The second member has a second abutment portion capable of abutting against the shuttle stopper portion that rotates in a reverse direction opposite to the forward rotation. The first abutment portion and the second abutment portion are opposite to each other in a second direction intersecting and parallel to the first direction, and the size of the gap formed between the first abutment portion and the second abutment portion can be changed by moving at least one of the first member and the second member along the second direction.

2. The sewing machine according to claim 1, characterized in that: The sewing machine comprises: a driving unit connected to at least one of the first member and the second member to move at least one of the first member and the second member along the second direction; and A control member controls movement of at least one of the first member and the second member in the second direction using the drive unit when sewing is performed using the shuttle mechanism.

3. The sewing machine according to claim 2, characterized in that: The driving portion is connected to the second member.

4. The sewing machine according to claim 2, characterized in that: The driving unit is a direct acting cylinder.

5. The sewing machine according to claim 3, characterized in that: When the sewing is started, the control means moves the second member arranged at the initial position in the second direction in a direction in which the gap becomes larger by using the driving unit, thereby arranging the second member at the first sewing position.

6. The sewing machine according to claim 5, characterized in that When the sewing is finished, the control means moves the second member disposed at the first sewing position in the second direction in a direction where the gap becomes smaller by using the drive unit, thereby disposing the second member at the initial position.

7. The sewing machine according to claim 3, characterized in that: The sewing machine comprises: a determining member that determines a traveling direction of the sewn article from the position of the Nth needle toward the position of the N+1th needle, wherein N is a natural number; and a determining means for determining whether the traveling direction determined by the determining means is within a predetermined range, When the determination component determines that the travel direction is within the predetermined range, when starting the sewing of the N+1th needle, the control component moves the second member configured to the first sewing position along the second direction, thereby configuring the second member to a second sewing position different from the first sewing position.

8. The sewing machine according to claim 7, characterized in that The second sewing position is a position of the second member after the second member disposed at the first sewing position is moved by the driving unit in the direction in which the gap is reduced in the second direction. When the value of N+1 is equal to or smaller than a predetermined value M, the control means does not arrange the second member arranged at the first sewing position at the second sewing position. Here, M is a natural number equal to or greater than 2.

9. The sewing machine according to claim 1, characterized in that The lower end of the first abutting portion and the lower end of the second abutting portion are located above the hook tip, and the lower end of the second abutting portion is located above the lower end of the first abutting portion.

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