Upper thread holding mechanism and sewing device

Abstract

The present invention provides a surface thread holding mechanism and a sewing device, which reduce the possibility of the surface thread end being caught in the stitch compared with the past. The surface thread holding mechanism (80) includes a first holding member (81), a second holding member (82) and a holding movable portion. The first holding member (81) is arranged below the needle plate (11), and the second holding member (82) includes a first holding portion (86), a second holding portion (87) and a supporting portion (84). The first holding portion is arranged below the needle plate (11) and above the first holding member (81). The second holding portion (87) is arranged below the first holding member. The supporting portion (84) supports the first holding portion and the second holding portion so that they can move in the horizontal direction. The holding movable portion has a motor, and uses the power of the motor to move the second holding member (82) in the horizontal direction. The holding movable portion can move the second holding member (82) to a standby position (Q1) and a holding position (Q2).

Description

Technical Field

[0001] The present invention relates to an upper thread holding mechanism and a sewing device. Background Art

[0002] Conventional sewing devices have a thread cutting mechanism and an upper thread clamping mechanism between the needle plate and the rotary hook. The thread cutting mechanism has a movable knife and a fixed knife. At the end of sewing, the thread cutting mechanism causes the movable knife to rotate back and forth in the horizontal direction to cut the upper thread extending from the eye of the needle through the processed fabric and the lower thread extending from the rotary hook. The upper thread clamping mechanism has a first thread clamping member and a second thread clamping member. When the needle of the first stitch after sewing starts moves to the upper side of the needle plate, the upper thread clamping mechanism rotates the second thread clamping member to the clamping position and clamps the thread end in cooperation with the first thread clamping member.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-278928 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In conventional sewing devices, when the length of the upper thread clamped by the upper thread clamping mechanism is relatively long, the end of the upper thread may be entangled in the stitch.

[0008] An object of the present invention is to provide an upper thread holding mechanism and a sewing device in which the possibility of an upper thread end being caught in a stitch is reduced compared to conventional ones.

[0009] Solutions for solving problems

[0010] Technical solution 1 of the present invention provides a surface thread holding mechanism, wherein the surface thread holding mechanism comprises: a first holding member, which is arranged below the needle plate, and the needle plate is formed with a needle hole for the needle of the sewing device to be inserted; a second holding member, which cooperates with the first holding member to hold the thread end of the surface thread, the second holding member having a first holding part arranged below the needle plate and above the first holding member, a second holding part arranged below the first holding member, and a supporting part that supports the first holding part and the second holding part so as to be movable in the horizontal direction; and a holding moving part, which has a motor, which uses the power of the motor to move the second holding member in the horizontal direction, and the holding moving part can move the second holding member to a standby position and a holding position, the standby position is the position when the needle hole is arranged between the first holding member and the second holding member in the horizontal direction, and the holding position is the position when the second holding member is separated from the needle hole in the horizontal direction and the second holding member overlaps with the first holding member in the vertical direction. The needle thread holding mechanism of Technical Solution 1 is capable of holding the needle thread end portion in an S-shaped state bent along the first and second holding members by positioning the second holding member in the holding position. Compared to a mechanism that does not hold the needle thread end portion in an S-shaped state, the needle thread holding mechanism can extend the length of the portion held by the needle thread holding mechanism, thereby reducing the possibility of the needle thread end portion being entangled in the stitch compared to conventional mechanisms.

[0011] In the needle thread holding mechanism of technical solution 2 of the present invention, at least one of the first holding portion and the second holding portion is formed with an insertion portion that allows the needle to pass through when the second holding member is located in the standby position. The needle thread holding mechanism of technical solution 2 guides the end of the needle thread to the position held by the first holding member and the second holding member when the second holding member moves to the holding position by the insertion portion provided in at least one of the first holding portion and the second holding portion, thereby being able to more stably hold the end of the needle thread.

[0012] In the needle thread holding mechanism of Technical Solution 3 of the present invention, the support portion of the second holding member is a pin member perpendicular to the needle plate, and the second holding member is rotatably supported by the needle plate via the support portion and can be rotated to the standby position and the holding position about the support portion. The needle thread holding mechanism of Technical Solution 3 enables the second holding member to stably move to the standby position and the holding position about the pin member.

[0013] In the needle thread holding mechanism according to claim 4 of the present invention, the support portion is provided on the motor side relative to the needle receiving hole in a direction extending from the motor toward the needle receiving hole on a surface parallel to the needle plate. The needle thread holding mechanism can increase the degree of freedom in design of the side of the needle receiving hole opposite to the motor side in a direction extending from the motor toward the needle receiving hole on a surface parallel to the needle plate.

[0014] Technical solution 5 of the present invention provides a sewing device, wherein the sewing device comprises: a needle bar mechanism having a needle bar capable of assembling a machine needle at the lower end so that the needle bar can swing in the up-down direction; a needle plate formed with a needle hole for inserting the machine needle; and an upper thread holding mechanism according to any one of technical solutions 1 to 4. In the sewing device of technical solution 5, by positioning the second holding member of the upper thread holding mechanism in the holding position, the upper thread end portion can be held in a state bent into an S-shape along the first holding member and the second holding member. In the sewing device, the length of the portion held by the upper thread holding mechanism can be extended compared to a mechanism that holds the upper thread end portion without bending the upper thread end portion into an S-shape, thereby reducing the possibility of the upper thread end portion being caught in the stitch compared to the past.

[0015] The sewing device of technical solution 6 of the present invention includes a cutting mechanism for cutting the upper thread and the lower thread, the cutting mechanism including a fixed knife and a movable knife. The fixed knife is fixed below the needle plate, and the movable knife is configured to be rotatable in the horizontal direction relative to the fixed knife. The movable knife is capable of moving between a knife standby position when the upper thread is separated from the fixed knife, a cutting position when the upper thread and the lower thread are cut by crossing the fixed knife, and a movable end position on the opposite side of the knife standby position relative to the cutting position. The movable knife is moved by the power of the motor. In the sewing device of technical solution 6, the power of the upper thread holding mechanism is shared with the cutting mechanism, thereby simplifying the structure compared to a sewing device in which the power of the upper thread holding mechanism and the power of the cutting mechanism are provided separately.

[0016] In the sewing device according to technical solution 7 of the present invention, the rotation center of the movable knife is located on the side opposite to the motor side relative to the needle receiving hole in the direction from the motor toward the needle receiving hole on a plane parallel to the needle plate. In the sewing device according to technical solution 7, when the second holding member of the upper thread holding mechanism rotates about the rotation center located on the motor side relative to the needle receiving hole in the direction from the motor toward the needle receiving hole on a plane parallel to the needle plate, the possibility of interference between the upper thread holding mechanism and the cutting mechanism can be reduced, and the degree of freedom in design of the motor side relative to the needle receiving hole can be increased.

[0017] The sewing device of technical solution 8 of the present invention further includes a control device that performs a needle thread holding control process for moving the second holding member from the standby position to the holding position after the first stitch is performed and before the second stitch is performed. In the sewing device of technical solution 8, the needle thread end can be held by moving the second holding member from the standby position to the holding position after the first stitch is performed and before the second stitch is performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is an overall perspective view of the sewing device 1.

[0019] Figure 2 It is a perspective view of the cutting mechanism 60 and the needle thread holding mechanism 80 .

[0020] Figure 3 It is an exploded perspective view of a part of the cutting mechanism 60 and a part of the needle thread holding mechanism 80 .

[0021] Figure 4 It is a bottom view of a part of the cutting mechanism 60 and a part of the upper thread holding mechanism 80 .

[0022] Figure 5 It is a bottom view of a part of the cutting mechanism 60 .

[0023] Figure 6 It is a bottom view of the motor 59 , the cam plate 70 , and the connecting rods 73 and 74 which are part of the link mechanism 72 .

[0024] Figure 7 It is a bottom view of a part of the needle thread holding mechanism 80 .

[0025] Figure 8 It is a block diagram showing the electrical configuration of the sewing device 1.

[0026] Figure 9 This is a flowchart of the main process of the sewing device 1.

[0027] Figure 10 (A) is a bottom view of a part of the motor 59, the cam plate 70 and the link mechanism 72 when the second holding member 82 is in the standby position Q1. Figure 10 (B) is a bottom view of a portion of the motor 59, the cam plate 70, and the link mechanism 72 when the second holding member 82 is in the holding position Q2. Figure 10 (C) is a bottom view of a part of the motor 59, the cam plate 70, and the link mechanism 72 when the second holding member 82 is at the needle thread cutting position Q3.

[0028] Figure 11(A) is a bottom view of a portion of the cutting mechanism 60 and a portion of the upper thread holding mechanism 80 when the second holding member 82 is in the standby position Q1. Figure 11 (B) is a bottom view of a portion of the cutting mechanism 60 and a portion of the upper thread holding mechanism 80 when the second holding member 82 is in the holding position Q2. Figure 11 (C) is a bottom view of a part of the cutting mechanism 60 and a part of the needle thread holding mechanism 80 when the second holding member 82 is at the needle thread cutting position Q3.

[0029] Figure 12 (A) is Figure 11 A cross-sectional view of the G1-G1 line of (A), Figure 12 (B) is Figure 11 (B) is a cross-sectional view of the G2-G2 line, Figure 12 (C) is Figure 11 (C) is a cross-sectional view taken along the G3-G3 line.

[0030] Figure 13 (A) is Figure 11 A cross-sectional view of the F1-F1 line of (A), Figure 13 (B) is Figure 11 (B) is a cross-sectional view of the F2-F2 line, Figure 13 (C) is Figure 11 (C) is a cross-sectional view taken along the F3-F3 line.

[0031] Figure 14 (A) is a bottom view of a part of the motor 59, the cam plate 70 and the link mechanism 72 when the movable knife 62 is at the movable end position P4. Figure 14 (B) is a bottom view of a part of the motor 59, the cam plate 70, and the link mechanism 72 when the movable knife 62 is at the cutting position P3.

[0032] Figure 15 (A) is a bottom view of a portion of the cutting mechanism 60 and a portion of the upper thread holding mechanism 80 when the movable knife 62 is at the movable end position P4. Figure 15 (B) is a bottom view of a part of the cutting mechanism 60 and a part of the needle thread holding mechanism 80 when the movable knife 62 is at the cutting position P3.

[0033] Description of Reference Numerals

[0034] 1. Sewing device; 11. Needle plate; 12. Needle hole; 14. Needle bar; 15. Needle; 30. Needle bar mechanism; 41. CPU; 59. Motor; 60. Cutting mechanism; 61. Fixed knife; 62. Movable knife; 69. Support shaft; 67. Moving part; 80. Upper thread holding mechanism; 81. First holding member; 82. Second holding member; 84. Support part; 86. First holding part; 87. Second holding part; 88. Insertion part; P1. Knife standby position; P3. Cutting position; P4. Movable end position; Q1. Standby position; Q2. Holding position; U. Upper thread end. DETAILED DESCRIPTION

[0035] The following description uses arrows in the drawings to indicate left, right, front, and back directions. The left, right, front, and back directions of the sewing device 1 are the X-axis, Y-axis, and Z-axis directions, respectively.

[0036] Reference Figure 1 , the structure of the sewing device 1 is described. In the sewing device 1, the sewing object 19 is transported along the X-axis direction and the Y-axis direction relative to the needle 15, and sewing can be performed in a 360-degree direction. The sewing object 19 is, for example, cloth, leather, etc. The sewing device 1 includes a base portion 2, a support portion 3, an arm portion 4, a cloth feeding device 5, and a control portion 10 (see Figure 8 ) and an operating panel 18. The base portion 2 is provided on the sewing machine table 6. The base portion 2 is provided with a workbench 7 on the front side of the upper surface. The workbench 7 is provided with a needle plate 11 approximately in the center. A needle hole 12 is formed approximately in the center of the needle plate 11. The sewing device 1 is provided with a lower shaft and a vertical shuttle (not shown) inside the base portion 2. The vertical shuttle is arranged below the needle plate 11, and the lower shaft extends in the front-to-back direction. The front end portion of the lower shaft is connected to the vertical shuttle. The vertical shuttle accommodates a bobbin wound with the bottom thread and swings back and forth around the lower shaft.

[0037] The support part 3 extends upward from the rear part of the base part 2. The arm part 4 extends forward from the upper part of the support part 3 and supports the main shaft rotatably inside. The main shaft extends in the front-to-back direction and is connected to the main motor 17 (see Figure 8 ) is connected. The connecting rod extends in the vertical direction inside the support portion 3. The main shaft is connected to the lower shaft via the connecting rod. Therefore, when the main motor 17 is driven, the main shaft rotates, and as the main shaft rotates, the vertical shuttle is driven. The sewing machine table 6 is provided with an operation panel 18 on the right side of the upper surface. The operation panel 18 is, for example, a touch panel, and includes a display unit 13 and an input unit 16. The display unit 13 displays various information, and the input unit 16 receives input of various information such as instructions for starting sewing.

[0038] The arm portion 4 has a top portion 8 at the front end. The lower end of the top portion 8 is opposite to the upper surface of the needle plate 11. The top portion 8 supports the needle bar 14 and the pressure bar 20 so that they can move up and down. The needle bar 14 extends in the up and down direction and protrudes downward from the top portion 8. The needle bar 14 is equipped with a needle 15 at the lower end. The needle 15 has an eye, and the upper thread is passed through the eye to hold the upper thread. The needle bar 14 is connected to the main shaft. When the needle bar 14 moves up and down due to the rotation of the main shaft, the needle 15 moves up and down and passes through the needle hole 12. The needle 15 moving up and down cooperates with the vertical shuttle to form a stitch on the sewing object 19. The pressure bar 20 extends in the up and down direction to the left of the needle bar 14 and protrudes downward from the top portion 8. The presser foot 9 is equipped with the presser foot 9 at the lower end of the presser bar 20. The presser foot 9 intermittently presses the sewing object 19 downward.

[0039] The cloth feeding device 5 includes an X motor 21 (see Figure 8 ), cloth holding body 22, support portion 23, rod portion 24, Y motor 25 (refer to Figure 8 ) etc. The cloth feeding device 5 includes an X-guide rail, an X-moving plate, a Y-guide rail, and a Y-moving plate (not shown). The X-motor 21 is provided at the rear side inside the machine base 2. The X-guide rail extends in the X-axis direction inside the machine base 2 and in front of the X-motor 21. The X-moving plate is connected to the X-guide rail and to the X-motor 21 so as to be movable left and right. The X-moving plate moves left and right along the X-guide rail under the driving force of the X-motor 21. The Y-guide rail is fixed to the upper surface of the X-moving plate and extends in the Y-axis direction. The Y-guide rail moves left and right as a whole with the X-moving plate. The Y-moving plate is connected so as to be movable forward and backward relative to the Y-guide rail. The cloth holding body 22 is fixed to the upper surface of the Y-moving plate. The cloth holding body 22 moves left and right as a whole with the X-moving plate and the Y-moving plate, and moves forward and backward as a whole with the Y-moving plate. Therefore, the cloth holding body 22 can move in the horizontal direction. The support part 23 is connected to the rear part of the pressure arm 32 of the cloth holding body 22. The support portion 23 is capable of left-right movement along with the cloth holder 22. A rod 24 extends rearward from the support portion 23 into the interior of the support column 3 and is capable of forward and backward movement. The front end of the rod 24 is connected to the support portion 23 via a slider. A Y motor 25 is located within the support column 3 and is connected to the rod 24. When the rod 24 moves forward and backward under the driving force of the Y motor 25, the support portion 23, the cloth holder 22, and the Y movable plate move forward and backward in unison.

[0040] The cloth holding body 22 includes a conveying plate 31, a pressing arm 32, a pair of connecting parts 33, a pressing frame 34 and a pair of air cylinders 35 (in Figure 1Only one is shown in the figure). The conveying plate 31 extends forward from the upper surface of the Y movable plate and is provided with a clamping frame 36 at the front end. The clamping frame 36 is rectangular in shape when viewed from above and can support the sewing object 19. The pressing arm 32 extends upward from the rear end of the conveying plate 31 and then bends and extends forward. The pressing arm 32 clamps the rear end of the conveying plate 31 between the pressing arm 32 and the upper surface of the Y movable plate to fix the conveying plate 31. The top end 37 of the pressing arm 32 is roughly rectangular in shape when viewed from the front. A pair of connecting parts 33 are arranged in the left and right directions at the top end 37 and can move up and down. The pair of connecting parts 33 support the pressing frame 34. The pressing frame 34 is roughly rectangular in shape when viewed from above and is opposite to the clamping frame 36 in the up and down directions. A pair of cylinders 35 are provided on the left and right parts of the pressing arm 32. The pair of cylinders 35 are respectively connected to the pair of connecting parts 33. When the pair of air cylinders 35 are driven to move the pair of connecting parts 33 up and down, the pressing frame 34 moves up and down between a clamping position and a release position. The clamping position is the position of the pressing frame 34 when it presses the sewing object 19 supported by the clamping frame 36 from above. The release position is the position of the pressing frame 34 when it moves upward away from the sewing object 19. The sewing device 1 can sew in a 360-degree direction by moving the cloth retaining body 22 holding the sewing object 19 relative to the needle 15 in the X-axis and Y-axis directions.

[0041] like Figure 2 In this way, the sewing device 1 is provided with a cutting mechanism 60 and an upper thread holding mechanism 80 on the lower surface side of the needle plate 11. The cutting mechanism 60 is driven by the power of the motor 59 and cuts the upper thread and the lower thread at the end of the sewing operation. The upper thread holding mechanism 80 is driven by the power of the motor 59 and releasably holds the upper thread end U of the upper thread after passing through the needle 15 on the lower side of the needle plate 11 (refer to FIG. Figure 12 ). The upper thread holding mechanism 80 bends and holds the upper thread that has passed under the sewing object 19 when the first needle is passed at the start of sewing. Therefore, the upper thread holding mechanism 80 prevents the upper thread from coming out of the needle 15. The motor 59 is fixed to the back side of the machine base 2 of the sewing device 1. The motor 59 is a pulse motor and is the driving source of the cutting mechanism 60 and the upper thread holding mechanism 80.

[0042] like Figures 2 to 5 As such, the cutting mechanism 60 includes a fixed knife 61, a movable knife 62, a force-applying member 65, a support shaft 69, and a movable portion 67. As shown in the figure, the fixed knife 61 is fixed to the lower side of the needle plate 11, which is formed with a needle hole 12 for inserting the needle 15 of the sewing device 1. The fixed knife 61 is roughly L-shaped when viewed from above and is fixed to the lower surface of the needle plate 11 by two screws 611. The fixed knife 61 includes a knife portion 612. The knife portion 612 is provided at the right rear portion of the fixed knife 61 and extends from the left side of the needle hole 12 toward the front of the needle hole 12.

[0043] The movable knife 62 is configured to be able to rotate horizontally relative to the fixed knife 61. The movable knife 62 includes a line dividing portion 621, a knife portion 622, a thread engaging portion 623, a thread guide portion 624, a thread catching portion 625, a thread clamping portion 66, and a thread loosening portion 68. The line dividing portion 621 has a top portion that tapers toward the rear and is the portion that enters the upper thread loop formed by the upper thread. The knife portion 622 is the end of a through hole that passes through the movable knife 62 in the vertical direction and is circular when viewed from above. The thread engaging portion 623 is the portion of the upper thread loop that is hooked on the side extending from the needle 15. The thread guide portion 624 is a portion that bends between the line dividing portion 621 and the thread catching portion 625 on the side opposite to the pin 763 of the connecting rod 76 relative to the support shaft 69. The thread guide portion 624 guides the side of the upper thread loop that extends from the sewing object 19 to the thread catching portion 625. The thread catching portion 625 is a portion that catches the upper thread loop.

[0044] The thread clamping portion 66 is a bottom line end portion D of the bottom surface of the movable blade 62 that can clamp the bottom line cut by the movable blade 62 between the bottom surface and the biasing member 65 (see FIG. Figure 13 (A)). The thread release portion 68 is the portion of the lower surface of the movable blade 62 that cannot clamp the bottom thread end D between the movable blade 62 and the biasing member 65. The thread release portion 68 is the portion of the lower surface of the movable blade 62 that contacts the thread catching portion 625 and is located adjacent to the thread clamping portion 66. This portion is recessed upward. In other words, the thread clamping portion 66 is located below the thread release portion 68.

[0045] Insertion portions 626 and 627 are formed in the movable blade 62. The insertion portion 626 is an end portion (in the longitudinal direction of the movable blade 62) provided on the side opposite to the side provided with the dividing line portion 621. Figure 3 The position is the rear end portion of the movable knife 62) and is a hole that passes through in the up-down direction. The insertion portion 626 is for the pin 763 of the connecting rod 76 described later to be inserted. The insertion portion 627 is a hole that is provided in the center portion in the longitudinal direction of the movable knife 62 and passes through in the up-down direction. The support shaft 69 is inserted through the insertion portion 627 and is fixed to the lower surface of the needle plate 11, supporting the movable knife 62 so as to be able to reciprocate in a horizontal direction parallel to the needle plate 11. The support shaft 69, which serves as the rotation center of the movable knife 62, is in a direction from the motor 59 toward the needle hole 12 on a surface parallel to the needle plate 11. In this embodiment, it is in the front-to-back direction and is provided on the side opposite to the motor 59 side relative to the needle hole 12. The support shaft 69 is located to the right of the screw 611.

[0046] like Figure 4In this way, the force member 65 is fixed to the lower side of the needle plate 11 at a position in front of the specific volume needle hole 12 by two screws 651. The force member 65 is a bent leaf spring. The force member 65 includes a fixing portion 652, a pressing portion 653 and guide portions 654 and 655. The fixing portion 652 is a plate-shaped portion extending from the front of the specific volume needle hole 12 to the right rear and parallel to the needle plate 11, and is fixed to the needle plate 11 by two screws 651. The pressing portion 653 is a portion that is bent downward from the left rear end portion of the fixing portion 652 and then bent backward to form a U-shape when viewed from above. The pressing portion 653 is gently inclined toward the lower rear side. As shown in FIG. Figure 13 As shown in (A), guide portion 654 is a portion located behind pressing portion 653, tilting downward as it moves toward the rear. Guide portion 655 is a portion that curves upward from the left end of guide portion 654. Guide portions 654 and 655 guide the movement of movable blade 62, positioned between biasing member 65 and needle plate 11. Biasing member 65 biases thread clamping portion 66 of movable blade 62 upward.

[0047] like Figure 2 The moving part 67 has a motor 59 and uses the power of the motor 59 to rotate the movable knife 62 in the horizontal direction. The moving part 67 includes a motor 59, a cam plate 70 and a link mechanism 72. The motor 59 is a pulse motor and is fixed to the lower back of the base 2 with the output shaft 98 facing downward (see FIG. Figure 1 The cam plate 70 converts the rotational force of the output shaft 98 of the motor 59 into power to drive the link mechanism 72. The link mechanism 72 drives the movable knife 62 of the cutting mechanism 60 in accordance with the rotational direction and angle of the cam plate 70, thereby cutting the upper thread and the lower thread. The link mechanism 72 drives the second holding member 82 of the upper thread holding mechanism 80 in accordance with the rotational direction and angle of the cam plate 70, thereby holding the upper thread end U at a predetermined timing at the start of sewing.

[0048] like Figure 6 Thus, the cam plate 70 is positioned below the motor 59 and fixed to the top end of the output shaft 98 of the motor 59. The cam plate 70 is formed into a generally semicircular shape when viewed from above, with a shaft hole 701 formed in the center. The top end of the output shaft 98 of the motor 59 is inserted into and fixed to the shaft hole 701. The cam plate 70 rotates integrally with the output shaft 98. The cam plate 70 includes a grooved cam 71 extending approximately 180 degrees around the shaft hole 701. The grooved cam 71 is semicircular in shape when viewed from above, and is formed as a groove formed by recessing the lower surface of the cam plate 70 in the thickness direction.

[0049] like Figure 2 and Figure 6Thus, the link mechanism 72 includes links 73 to 76 and a roller member 77. Links 73 to 76 are arranged in sequence from the motor 59 side toward the cutting mechanism 60 side. Link 73 has a roughly L-shaped plate shape when viewed from above and is located below cam plate 70. Roller member 77 is rotatably fixed above one end 731 of link 73. Roller member 77 includes a vertically extending rotational axis. Roller member 77 engages with grooved cam 71 of cam plate 70. A shaft hole 734 is provided in the center portion 733 of link 73, which is curved at a substantially right angle between one end 731 and the other end 732. A support shaft 735 is inserted into shaft hole 734, allowing link 73 to rotate about support shaft 735. Roller member 77 engages with grooved cam 71 of cam plate 70. The other end 732 of link 73 is rotatably connected to one end 741 of link 74 via a pin 736.

[0050] The connecting rod 74 is in the shape of a rod extending in the front-to-back direction. The other end 742 of the connecting rod 74 is fixed to the one end 751 of the connecting rod 75 by means of a screw 743. The connecting rod 75 is a C-shaped plate member with the right side open when viewed from the front. The other end 752 of the connecting rod 75 is located above the one end 751 and is fixed to the one end 761 of the connecting rod 76 by means of a screw 744. The central portion 753 extending in the vertical direction of the connecting rod 75 is provided for the support shaft 754 extending in the vertical direction to be inserted. The connecting rod 75 can rotate around the support shaft 754. The connecting rod 76 extends in the front-to-back direction. As Figure 3 and Figure 4 In this way, the other end portion 762 of the connecting rod 76 bulges out in a roughly arc shape to the right. The other end 762 of the connecting rod 76 has pins 763 and 764 protruding upward. The pin 763 is provided at the front end portion of the connecting rod 76 and is inserted into the insertion portion 626 of the movable knife 62. The movable knife 62 is connected to the connecting rod 76 through the pin 763 of the connecting rod 76. The pin 764 is provided at a position farther back than the pin 763 and is inserted into the insertion portion 861 of the second holding member 82 of the surface thread holding mechanism 80 described later. The second holding member 82 is connected to the connecting rod 76 through the pin 764 of the connecting rod 76. The connecting rod 76 is located below the second holding member 82 and the movable knife 62.

[0051] The moving part 67 uses the power of the motor 59 to move the connecting rod 76 in the front-back direction, thereby enabling the movable knife 62 to rotate in the horizontal direction parallel to the needle plate 11 around the support shaft 69. The moving part 67 can move the movable knife 62 to the front-back direction according to the driving of the motor 59. Figure 5 The knife shown is in the standby position P1, the release position P2, the cutting position P3, and the movable end position P4. Figure 5 In FIG, members other than the fixed blade 61 , the movable blade 62 , and the link 76 are omitted from illustration, and the position of the movable blade 62 is represented by the position of the blade portion 622 .

[0052] The knife standby position P1 is when the movable knife 62 is spaced apart from the stationary knife 61, and the thread clamping portion 66 of the movable knife 62 is positioned between the needle plate 11 and the biasing member 65, facing the biasing member 65. The thread clamping portion 66 can, together with the biasing member 65, clamp the bobbin thread end D. The release position P2 is when the thread release portion 68 of the movable knife 62 is positioned between the needle plate 11 and the biasing member 65, facing the biasing member 65. The cutting position P3 is when the movable knife 62 and the stationary knife 61 intersect to cut the upper and lower threads. The movable end position P4 is located on the opposite side of the knife standby position P1 relative to the cutting position P3. Specifically, the movable end position P4 is located counterclockwise relative to the cutting position P3 when viewed from above, with the support shaft 69 as the center, while the knife standby position P1 is located clockwise relative to the cutting position P3 when viewed from above, with the support shaft 69 as the center. On the moving track J1 of the movable knife 62, the cutting position P3 is located between the knife standby position P1 and the movable end position P4, and the releasing position P2 is located between the knife standby position P1 and the cutting position P3. The main process of the sewing device 1 moving the movable knife 62 to each position will be described later.

[0053] like Figures 2 to 4 and Figure 7 As such, the upper thread holding mechanism 80 includes a first holding member 81, a second holding member 82 and a moving portion 67. The upper thread holding mechanism 80 of this embodiment further includes a fixed cutter 97. The moving portion 67 is common to the above-mentioned cutting mechanism 60. The first holding member 81 is provided below the needle plate 11, and the needle plate 11 is formed with a needle hole 12 for the needle 15 of the sewing device 1 to pass through. The first holding member 81 is a plate-shaped member that is longer in the left-right direction and extends in a horizontal direction parallel to the needle plate 11. The first holding member 81 extends in the horizontal direction at a position lower than the thread guide portion 624 of the movable knife 62. The first holding member 81 is arranged on the left relative to the needle hole 12 and is fixed to the lower side of the needle plate 11 by a pair of front and rear screws 811. The right end of the first holding member 81 is inclined more and more rearward as it moves toward the right. As shown Figure 13 As shown in (A), the first holding portion 86 of the second holding member 82 and the movable blade 62 are arranged on the same horizontal plane. Here, the same horizontal plane refers to an arbitrary imaginary horizontal plane passing through both the first holding portion 86 and the movable blade 62, and the vertical extension range of the first holding portion 86 and the vertical extension range of the movable blade 62 at least partially overlap.

[0054] like Figures 2 to 4 and Figure 7In this way, the second holding member 82 cooperates with the first holding member 81 to hold the needle thread end U of the needle thread. The second holding member 82 includes a first holding portion 86, a second holding portion 87, and a support portion 84. The first holding portion 86 is provided below the needle plate 11 and above the first holding member 81. The first holding portion 86 is provided with an insertion portion 88, which is a plate-like shape that is long in the front-to-back direction and is located at the second holding member 82. Figure 7 The needle 15 is allowed to pass through when the needle 15 is in the standby position Q1. The first holding portion 86 is formed with insertion portions 861, 863 and a pair of threaded holes 862. The insertion portion 861 is a hole that passes through in the up-down direction and is provided at the end of the first holding portion 86. The pin 764 of the connecting rod 76 is inserted into the insertion portion 861. The insertion portion 863 is a hole that passes through in the up-down direction and is provided in front of the insertion portion 861. The second holding member 82 is supported by the support portion 84 inserted into the insertion portion 863 of the first holding portion 86 so as to be able to rotate in a horizontal direction parallel to the needle plate 11. The support portion 84 is a pin member arranged perpendicular to the needle plate 11. The second holding member 82 is supported by the support portion 84 inserted into the first holding portion 86 so as to be able to rotate in a horizontal direction parallel to the needle plate 11. The support portion 84 is provided behind the needle hole 12. Specifically, the support portion 84 is located on the side of the motor 59 with respect to the needle receiving hole 12, both in the direction from the motor 59 toward the needle receiving hole 12 and in the opposite direction (in this embodiment, the front-to-back direction) on a surface parallel to the needle plate 11. The distance between the center of the support shaft 69 and the center of the pin 764 is smaller than the distance between the center of the support portion 84 and the center of the pin 764. Therefore, the amount of rotation of the movable knife 62 relative to the movement of the connecting rod 76 is greater than the amount of rotation of the second retaining member 82 relative to the movement of the connecting rod 76.

[0055] The second holding portion 87 is a plate-shaped portion that is longer in the front-to-back direction and is located below the first holding member 81. The length of the second holding portion 87 in the front-to-back direction is shorter than the length of the first holding portion 86 in the front-to-back direction. The second holding portion 87 is formed with an insertion portion 89 that allows the needle 15 to pass through when the second holding member 82 is in the standby position Q1. The second holding portion 87 is formed with two holes 872 that pass through in the upper and lower directions. The second holding portion 87 is fixed to the lower surface of the first holding portion 86 by screws 871 inserted into the holes 872 in a state where it overlaps with the first holding portion 86. At this time, the second holding portion 87 is located in a position that is further forward than the support portion 84. The insertion portions 88 and 89 of this embodiment are notches that are open to the left, and the outlines of the insertion portions 88 and 89 when viewed from above overlap each other. The insertion portions 88 and 89 are formed on the side opposite to the insertion portion 861 in the second holding member 82 relative to the support portion 84. The second holding portion 87 cannot move relative to the first holding portion 86, but moves horizontally together with the first holding portion 86. Figure 12As shown in (A), the thickness of the first holding portion 86 and the second holding portion 87 is greater than the thickness of the first holding member 81. The thickness of the first holding portion 86 is greater than the thickness of the second holding portion 87.

[0056] like Figure 3 In this way, the fixed cutter 97 is fixed to the lower side of the needle plate 11, and the needle plate 11 is formed with a needle hole 12 for the needle 15 to be inserted. The fixed cutter 97 has a knife part 96. The knife part 96 is provided on the right side of the fixed cutter 97 and is arranged on the left side of the needle hole 12. Figure 12 As shown in (A), the right end of the blade portion 96 is tilted downward and to the right. The fixed cutter 97 has a pair of front and rear holes 971 extending vertically therethrough. The fixed cutter 97 is positioned above the first retaining member 81. The fixed cutter 97 is secured to the lower side of the needle plate 11 together with the first retaining member 81 by screws 811 inserted through the pair of holes 971.

[0057] The movable portion 67 is connected to the second holding member 82 by inserting the pin 764 of the connecting rod 76 into the insertion portion 861 of the second holding member 82. The movable portion 67 uses the power of the motor 59 to move the connecting rod 76 back and forth, thereby enabling the second holding member 82 to rotate in a horizontal direction parallel to the needle plate 11 with the support portion 84 as the center. In other words, the movable portion 67 can move the movable knife 62 and the second holding member 82 separately. Specifically, the movable portion 67 moves the second holding member 82 to Figure 7 The standby position Q1, holding position Q2, upper thread cutting position Q3, cutting position Q4 and movable end position Q5 are shown. Figure 7 In the figure, the illustration of components other than the first retaining portion 86, the second retaining portion 87, the supporting portion 84, the fixed cutter 97 and the connecting rod 76 is omitted, and the position of the second retaining member 82 is represented by the position of an imaginary circle inscribed in the arc-shaped right end portion of the insertion portion 89.

[0058] The standby position Q1 is the position when the needle hole 12 is arranged horizontally between the first holding member 81 and the second holding member 82. The holding position Q2 is the position when the second holding member 82 is separated from the needle hole 12 in the horizontal direction and the second holding member 82 and the first holding member 81 overlap in the vertical direction. The upper thread cutting position Q3 is the position when the upper thread end U held by the first holding member 81 and the second holding member 82 is cut by the fixed cutter 97. On the movable track J2 of the second holding member 82, the holding position Q2 is located between the standby position Q1 and the upper thread cutting position Q3. The cutting position Q4 and the movable end position Q5 are positions corresponding to the cutting position P3 and the movable end position P4 of the movable knife 62, respectively. The main process of the sewing device 1 moving the second holding member 82 to each position will be described later.

[0059] Reference Figure 8 The electrical structure of the sewing device 1 is described. The control unit 10 of the sewing device 1 includes a CPU 41, a ROM 42, a RAM 43, a storage device 45, an I / O interface (hereinafter referred to as I / O) 46, and drive circuits 51 to 56. The CPU 41 controls the operation of the sewing device 1. The CPU 41 is connected to the ROM 42, the RAM 43, the storage device 45, and the I / O 46. The ROM 42 stores the main processing (see FIG. 4) to be executed. Figure 9 ) and other processing programs. RAM43 temporarily stores various information. Storage device 45 is non-volatile and stores sewing information, etc. Sewing information is information including needle drop points.

[0060] I / O 46 is connected to drive circuits 51-56 and the input unit 16. Drive circuit 51 is connected to the main motor 17. Drive circuit 52 is connected to the X motor 21. Drive circuit 53 is connected to the Y motor 25. Drive circuit 56 is connected to motor 59. X motor 21, Y motor 25, and motor 59 are pulse motors. Drive circuit 54 is connected to the pair of air cylinders 35. Drive circuit 55 is connected to the display unit 13. The CPU 41 controls the drive circuits 51-54 to drive and control the main motor 17, X motor 21, Y motor 25, and the pair of air cylinders 35. The CPU 41 controls the display unit 13 by controlling the drive circuit 56. The input unit 16 detects information input by the operator and outputs the detection results to the CPU 41 via I / O 46.

[0061] Encoders 91 to 93 are connected to the main motor 17, the X motor 21, and the Y motor 25, respectively. Encoder 91 detects the rotational position of the output shaft of the main motor 17. Encoder 92 detects the rotational position of the output shaft of the X motor 21. Encoder 93 detects the rotational position of the output shaft of the Y motor 25. Encoders 91 to 93 output the detection results to the CPU 41 via the I / O 46.

[0062] Reference Figures 9 to 15, describing the main processing performed by the sewing device 1 of specific examples 1 and 2 in which the timing of cutting the upper thread is different from each other. In the main processing, a process of forming a stitch on the sewing object 19 according to the sewing pattern is performed. When the power of the sewing device 1 is turned on, the CPU 41 starts the main processing. When the power of the sewing device 1 is turned on, the CPU 41 reads the program for executing the main processing stored in the program storage area of ​​the ROM 42 to the RAM 43. The CPU 41 executes the following steps according to the instructions contained in the program read to the RAM 43. Hereinafter, the steps will be referred to as S. Various parameters required for executing the main processing are stored in the storage device 45. Various data obtained during the main processing are appropriately stored in the RAM 43. The timing of cutting the upper thread only needs to be set before executing the main processing. It can be set by the operator or automatically set according to the sewing conditions such as the type and thickness of the sewing object 19.

[0063] like Figure 9 Then, the CPU 41 determines whether an origin detection instruction has been detected (S1). The operator operates the input unit 16 to input an origin detection instruction. If no origin detection instruction has been detected (S1: No), the CPU 41 returns the process to S1. If an origin detection instruction has been detected (S1: Yes), the CPU 41 performs origin detection (S2) and then raises the presser foot 9 (S3).

[0064] The operator places the sewing object 19 to be sewn between the cloth retaining body 22, operates the input unit 16, and inputs the lowering instruction of the presser foot 9. The CPU 41 determines whether the lowering instruction of the presser foot 9 is detected (S4). When the lowering instruction is not detected (S4: No), the CPU 41 returns the processing to S4. When the lowering instruction is detected (S4: Yes), the CPU 41 lowers the presser foot 9 (S5). Figure 10 As shown in (A), the roller member 77 provided at one end 731 of the link 73 of the moving portion 67 is located at the left end of the groove cam 71. Figure 11 As shown in (A), the movable knife 62 of the cutting mechanism 60 is located at the knife standby position P1, and the second holding member 82 of the surface thread holding mechanism 80 is located at the standby position Q1. That is, when the second holding member 82 is located at the standby position Q1, the movable knife 62 is located at the knife standby position P1. When viewed from above, the first holding member 81 and the second holding member 82 partially overlap in the up and down directions. When viewed from above, the needle hole 12 is surrounded by the first holding member 81 and the second holding member 82. The knife portion 622 of the movable knife 62 is located near the boundary between the guide portion 654 and the pressing portion 653. As Figure 12 As shown in (A), the second holding member 82 of the upper thread holding mechanism 80 is separated from the upper thread end U. The upper thread end U located below the needle receiving hole 12 is surrounded by the first holding member 81 and the second holding member 82. Figure 13As shown in FIG. 1A , the thread clamping portion 66 of the movable blade 62 of the cutting mechanism 60 vertically clamps the bottom thread end D together with the urging member 65 . The upper end of the pressing portion 653 of the urging member 65 abuts against the thread clamping portion 66 of the movable blade 62 .

[0065] The CPU 41 determines whether a sewing instruction is detected (S6). The operator operates the input unit 16 to input a sewing instruction. When no sewing instruction is detected (S6: No), the CPU 41 returns the process to S6. When a sewing instruction is detected (S6: Yes), the CPU 41 drives the main motor 17 and starts sewing the sewing pattern (S7). Based on the detection result of the encoder 91, the CPU 41 determines whether it is the upper thread holding timing (S8). The upper thread holding timing of the sewing device 1 of this embodiment is set after the first needle sewing is performed and before the second needle sewing is performed. When it is not the upper thread holding timing (S8: No), the CPU 41 returns the process to S8. When it is the upper thread holding timing (S8: Yes), the CPU 41 executes the upper thread holding control process (S9) to move the second holding member 82 from the standby position Q1 to the holding position Q2.

[0066] The CPU 41 drives the motor 59 so that the output shaft 98 of the motor 59 rotates clockwise from the origin to the Figure 10 (B) position. Figure 10 As shown in (B), the roller member 77 moves relatively from the left end of the groove cam 71 to a position after rotating in the counterclockwise direction when viewed from above. The connecting rod 73 rotates in the counterclockwise direction when viewed from above around the support shaft 735, moving the connecting rods 74 to 76. Figure 11 As shown in (B), the movable knife 62 of the cutting mechanism 60 moves to the rear of the knife standby position P1, and the second holding member 82 of the upper thread holding mechanism 80 moves from the standby position Q1 to the holding position Q2. The second holding member 82 is separated from the needle hole 12 in the horizontal direction, and the second holding member 82 overlaps with the first holding member 81 in the vertical direction. Figure 12 As shown in (B), the needle thread holding mechanism 80 holds the needle thread end U in a state bent into an S-shape in side view between the first holding member 81 and the second holding member 82. Figure 13 As shown in FIG. 1B , the thread clamping portion 66 of the movable blade 62 of the cutting mechanism 60 maintains a state of clamping the bottom thread end portion D in the vertical direction together with the urging member 65 .

[0067] Based on the detection result of the encoder 91, the CPU 41 determines whether it is the time to cut the upper thread (S10). The upper thread cutting timing of the sewing device 1 of this embodiment can be set after S9. In specific example 1, the upper thread cutting timing is set after the upper thread holding control process and before the needle drops of the second needle. In specific example 2, the upper thread cutting timing is set at a predetermined timing after the upper thread holding control process and after the needle drops of the second needle. The predetermined timing of specific example 2 can be set appropriately. In this example, it is after the needle drops of the third needle and before the needle drops of the fourth needle. When it is not the time to cut the upper thread (S10: No), the CPU 41 returns the processing to S10. When it is the time to hold the upper thread (S10: Yes), the CPU 41 controls the motor 59 to execute the upper thread cutting processing (S12) of moving the second holding member 82 from the holding position Q2 to the upper thread cutting position Q3 after S9. The CPU 41 controls the motor 59 to move the movable knife 62 from the knife standby position P1 to the release position P2, and executes a release process (S12) to release the bobbin thread end portion D clamped in the process of S17 of the previous main process.

[0068] The CPU 41 drives the motor 59 so that the output shaft 98 of the motor 59 moves from Figure 10 The position of (B) is rotated clockwise from looking up to Figure 10 (C) position. Figure 10 As in (C), the roller member 77 is Figure 10 The position of (B) moves relatively to the position after rotating in the counterclockwise direction when viewed from above. The connecting rod 73 rotates in the counterclockwise direction when viewed from above around the support shaft 735, so that the connecting rods 74 to 76 move. Figure 11 As shown in (C), the movable knife 62 of the cutting mechanism 60 moves to the released position P2, and the second holding member 82 of the needle thread holding mechanism 80 moves from the holding position Q2 to the needle thread cutting position Q3. The second holding member 82 is maintained in a state where it is separated from the needle hole 12 in the horizontal direction and the second holding member 82 and the first holding member 81 overlap in the vertical direction. The second holding member 82 overlaps with the knife portion 96 of the fixed cutter 97 in the vertical direction. When the movable knife 62 of the cutting mechanism 60 is in the range from the knife standby position P1 to the released position P2, the line dividing portion 621 of the movable knife 62 is located in front of the needle hole 12.

[0069] like Figure 12As shown in (C), the surface thread holding mechanism 80 maintains a state in which the surface thread end U is bent into an S-shape when viewed from the side between the first holding member 81 and the second holding member 82, and the first holding portion 86 of the second holding member 82 overlaps with the fixed cutter 97 in the up and down directions. As a result, the surface thread end U is cut by the fixed cutter 97. When the second holding member 82 moves from the holding position Q2 to the surface thread cutting position Q3, the first holding member 81 and the second holding member 82 continue to hold the surface thread end U. Therefore, the surface thread end U is cut by the fixed cutter 97 in a state held by the first holding member 81 and the second holding member 82. The position where the surface thread is to be cut by the fixed cutter 97 is the upstream side of the surface thread, i.e., the upper part, than the position where the surface thread is held by the first holding member 81 and the second holding member 82. As shown Figure 13 As shown in (C), the thread release portion 68 of the movable blade 62 of the cutting mechanism 60 and the pressing portion 653 of the biasing member 65 are separated and opposed in the vertical direction. The thread clamping portion 66 moves to a position retracted from the pressing portion 653 of the biasing member 65, and the state in which the thread end D is clamped in the vertical direction together with the biasing member 65 is released. As a result, the upper thread end U held by the upper thread holding mechanism 80 near the needle receiving hole 12 at the start of sewing is released after being cut, and the lower thread end D clamped by the cutting mechanism 60 is released.

[0070] The CPU 41 drives the motor 59 to move the movable knife 62 of the cutting mechanism 60 to the knife standby position P1 and the second holding member 82 of the needle thread holding mechanism 80 to the standby position Q1 (S13). The CPU 41 drives the output shaft 98 of the motor 59 from Figure 10 The position of (C) is rotated counterclockwise while looking up to Figure 10 The position of (A).

[0071] The CPU 41 determines whether the next needle drop action of the needle 15 is the last needle of the sewing action (S14). The CPU 41 counts the number of needle drops of the sewing pattern currently being sewn and stores it in the RAM 43. Therefore, the CPU 41 can determine whether the next needle drop action is the last needle by referring to the sewing information of the sewing pattern stored in the ROM 42. When it is not the last needle (S14: No), the CPU 41 returns the processing to S14 and continues the sewing action. When it is the last needle (S14: Yes), the CPU 41 stops the main motor 17 (S15).

[0072] The CPU 41 controls the motor 59 so that the movable knife 62 moves from the knife standby position P1 to the movable end position P4 and then moves to the cutting position P3 to execute the thread cutting process (S16) of cutting the upper thread and the lower thread. The CPU 41 drives the motor 59 so that the output shaft 98 of the motor 59 moves from the upper thread standby position P1 to the movable end position P4. Figure 10 The position of (A) is rotated clockwise from top to Figure 14 (A) position, the movable knife 62 moves from the knife standby position P1 to the movable end position P4. Figure 14 As shown in (A), the roller member 77 moves to the right end portion of the grooved cam 71 (aligned with the right end portion of the grooved cam 71). Figure 10 The connecting rod 73 rotates counterclockwise when viewed from above about the support shaft 735, so that the connecting rods 74 to 76 move. Figure 15 As shown in (A), the movable knife 62 of the cutting mechanism 60 moves to the movable end position P4. The knife portion 622 of the movable knife 62 is located behind the support shaft 69 and is located behind the larger volume needle hole 12. The thread clamping portion 66 and the thread loosening portion 68 of the movable knife 62 are both arranged in a position retracted relative to the force applying member 65. Part of the movable knife 62 passes above the first holding member 81 in the process of moving from the knife standby position P1 to the movable end position P4. The second holding member 82 of the surface thread holding mechanism 80 moves to the movable end position Q5. The second holding member 82 is separated from the larger volume needle hole 12 in the horizontal direction, and the second holding member 82 does not overlap with the first holding member 81 and the fixed cutter 97 in the vertical direction. The line dividing portion 621 of the movable knife 62 of the cutting mechanism 60 is located behind the support shaft 69 and is located behind the larger volume needle hole 12. The dividing line portion 621 of the movable blade 62 of the cutting mechanism 60 is located in front of the pin 764 and does not interfere with the second holding member 82 .

[0073] The CPU 41 drives the motor 59 so that the output shaft 98 of the motor 59 moves from Figure 14 The position of (A) is rotated counterclockwise while looking up to Figure 14 The movable blade 62 is moved from the movable end position P4 to the cutting position P3. Figure 14 As shown in (B), the roller member 77 moves relatively from the right end of the groove cam 71 to a position in which the roller member 77 moves in the clockwise direction when viewed from above. Figure 14 The position (A) is rotated clockwise in the upward direction around the support shaft 735 to move the connecting rods 74 to 76. Figure 15As shown in (B), the movable knife 62 of the cutting mechanism 60 moves to the cutting position P3. The knife portion 622 of the movable knife 62 is located at a position that overlaps with the needle hole 12 in the upper and lower directions. The front portion of the thread clamping portion 66 and the thread loosening portion 68 of the movable knife 62 is arranged in a position that is retracted relative to the force applying member 65. The second holding member 82 of the surface thread holding mechanism 80 moves to the cutting position Q4. The second holding member 82 is separated from the needle hole 12 in the horizontal direction, and the second holding member 82 does not overlap with the first holding member 81 and the fixed cutter 97 in the upper and lower directions. When the movable knife 62 of the cutting mechanism 60 is located in a position ranging from the movable end position P4 to the cutting position P3, the line dividing portion 621 of the movable knife 62 is located at a position farther rearward than the needle hole 12.

[0074] The CPU 41 controls the motor 59 to move the movable knife 62 from the cutting position P3 to the knife standby position P1, and performs a clamping process (S17) in which the bottom thread end D cut in the thread cutting process is clamped by the force applying member 65 and the thread clamping portion 66. The CPU 41 drives the motor 59 to move the output shaft 98 of the motor 59 from the cutting position P3 to the knife standby position P1. Figure 14 The position of (B) is rotated counterclockwise while looking up to Figure 10 The movable knife 62 is moved from the cutting position P3 to the knife standby position P1. The connecting rod 73 is moved from Figure 14 The position (B) is rotated clockwise when viewed from above with the support shaft 735 as the center, so that the connecting rods 74 to 76 move. In the process of moving the movable knife 62 from the cutting position P3 to the knife standby position P1, the bottom line end D cut in S16 is arranged on the thread clamping portion 66, and the thread clamping portion 66 is guided by the guide portions 654 and 655 of the force member 65, and is arranged between the force member 65 and the needle plate 11. As a result, as shown in FIG. Figure 13 As shown in (A), when the movable knife 62 moves from the cutting position P3 to the knife standby position P1, the bottom thread end D is clamped by the thread clamping portion 66 of the movable knife 62 and the pressing portion 653 of the biasing member 65. The bottom thread end D is clamped by the thread clamping portion 66 of the movable knife 62 and the pressing portion 653 of the biasing member 65 until the next main process is executed at S12. The CPU 41 then terminates the main process.

[0075] In the above embodiment, the sewing device 1, needle plate 11, needle hole 12, needle bar 14, needle 15, needle bar mechanism 30, and CPU 41 are examples of the sewing device, needle plate, needle hole, needle bar, needle, needle bar mechanism, and control device of the present invention, respectively. The upper thread holding mechanism 80, first holding member 81, second holding member 82, first holding portion 86, second holding portion 87, support portion 84, motor 59, and moving portion 67 are examples of the upper thread holding mechanism, first holding member, second holding member, first holding portion, second holding portion, support portion, motor, and holding and moving portion, respectively, of the present invention. The insertion portions 88 and 89 are examples of the insertion portion of the present invention. The cutting mechanism 60, fixed knife 61, movable knife 62, and support shaft 69 are examples of the cutting mechanism, fixed knife, movable knife, and rotation center of the present invention, respectively. The knife standby position P1, cutting position P3, movable end position P4, standby position Q1, and holding position Q2 are examples of the knife standby position, cutting position, movable end position, standby position, and holding position of the present invention, respectively. The process of S9 is an example of the needle thread holding control process of the present invention.

[0076] In the sewing device 1 of the above-described embodiment, the upper thread holding mechanism 80 includes a first holding member 81, a second holding member 82, and a moving portion 67. The first holding member 81 is located below the needle plate 11, which has a needle hole 12 formed therein for inserting the needle 15 of the sewing device 1. The second holding member 82 cooperates with the first holding member 81 to hold the upper thread end U. The second holding member 82 includes a first holding portion 86, a second holding portion 87, and a support portion 84. The first holding portion 86 is located below the needle plate 11 and above the first holding member 81. The second holding portion 87 is located below the first holding member 81. The support portion 84 supports the first holding portion 86 and the second holding portion 87 so that they can move horizontally. The moving portion 67 includes a motor 59, which uses the power of the motor 59 to move the second holding member 82 horizontally. The moving portion 67 moves the second holding member 82 between a standby position Q1 and a holding position Q2. The standby position Q1 is a position in which the needle hole 12 is arranged horizontally between the first holding member 81 and the second holding member 82. In the holding position Q2, the second holding member 82 is separated from the needle hole 12 in the horizontal direction. By positioning the second holding member 82 in the holding position Q2, the needle thread holding mechanism 80 can hold the needle thread end U in an S-shaped state bent along the first holding member 81 and the second holding member 82. Compared to a mechanism that does not hold the needle thread end U in an S-shape, the needle thread holding mechanism 80 can extend the length of the portion held by the needle thread holding mechanism 80, thereby reducing the possibility of the needle thread end U being caught in the stitch compared to the past.

[0077] The first holding portion 86 is formed with an insertion portion 88 that allows the needle 15 to pass through when the second holding member 82 is located in the standby position Q1, and the second holding portion 87 is formed with an insertion portion 89 that allows the needle 15 to pass through when the second holding member 82 is located in the standby position Q1. The surface thread holding mechanism 80 guides the surface thread end U to the position held by the first holding member 81 and the second holding member 82 when the second holding member 82 moves to the holding position Q2 by providing the insertion portion 88 in at least one of the first holding portion 86 and the second holding portion 87, thereby being able to more stably hold the surface thread end U.

[0078] The support portion 84 of the second holding member 82 is a pin member perpendicular to the needle plate 11. The second holding member 82 is rotatably supported by the needle plate 11 via the support portion 84 and can be rotated to the standby position Q1 and the holding position Q2 about the support portion 84. The needle thread holding mechanism 80 can stably move the second holding member 82 to the standby position Q1 and the holding position Q2 about the support portion 84.

[0079] The support portion 84 is provided on the motor 59 side relative to the needle receiving hole 12, in the direction from the motor 59 toward the needle receiving hole 12 on a surface parallel to the needle plate 11, that is, it is provided behind the needle receiving hole 12. The upper thread holding mechanism 80 can increase the degree of freedom in the design of the side of the needle receiving hole 12 opposite to the motor 59 side.

[0080] The sewing device 1 includes a needle bar mechanism 30, a needle plate 11, and an upper thread holding mechanism 80. The needle bar mechanism 30 includes a needle bar 14 to which a needle 15 can be attached at the lower end, so that the needle bar 14 can swing in the up and down directions. The needle plate 11 is formed with a needle hole 12 for the needle 15 to pass through. In the sewing device 1, by positioning the second holding member 82 of the upper thread holding mechanism 80 at the holding position Q2, the upper thread end U can be held in a state bent into an S-shape along the first holding member 81 and the second holding member 82. In the sewing device 1, the length of the portion held by the upper thread holding mechanism 80 can be extended compared to a mechanism that does not hold the upper thread end U bent into an S-shape, thereby reducing the possibility of the upper thread end U being caught in the stitches compared to the past.

[0081] The sewing device 1 includes a cutting mechanism 60 for cutting the upper thread and the lower thread. The cutting mechanism 60 includes a fixed knife 61, a movable knife 62, and a moving portion 67. The fixed knife 61 is fixed below the needle plate 11. The movable knife 62 is configured to be rotatable in the horizontal direction relative to the fixed knife 61, and is capable of moving between a knife standby position P1 when it is in a position separated from the fixed knife 61, a cutting position P3 when it crosses the fixed knife 61 to cut the upper thread and the lower thread, and a movable end position P4 on the side opposite to the knife standby position P1 relative to the cutting position P3. The moving portion 67 moves the movable knife 62 using the power of the motor 59. In the sewing device 1, the power of the upper thread holding mechanism 80 is shared with the cutting mechanism 60, so that the structure can be simplified compared to the sewing device 1 in which the power of the upper thread holding mechanism 80 and the power of the cutting mechanism 60 are independently provided. Furthermore, in the sewing device 1, the link mechanism 72 of the upper thread holding mechanism 80 is also shared with the cutting mechanism 60. Therefore, compared with a case where both are independent, the structure can be simplified and the degree of freedom in designing the space below the needle plate 11 can be increased.

[0082] The support shaft 69 of the movable knife 62 is provided on the side of the needle receiving hole 12 opposite to the motor 59 side in the direction from the motor 59 toward the needle receiving hole 12 on a surface parallel to the needle plate 11. In the sewing device 1, since the second holding member 82 of the upper thread holding mechanism 80 rotates around the support shaft 69 located on the motor 59 side relative to the needle receiving hole 12, the possibility of interference between the upper thread holding mechanism 80 and the cutting mechanism 60 can be reduced, thereby increasing the degree of freedom in design of the motor 59 side relative to the needle receiving hole 12.

[0083] Furthermore, the movable knife 62 of the sewing device 1 is arranged on the same horizontal plane as the first retaining member 86. When the movable knife 62 moves to the cutting position P3, the second retaining member 82 does not need to move to the cutting position Q4. However, if the second retaining member 82 is in the standby position Q1 while the movable knife 62 is in the cutting position P3, the movable knife 62 will interfere with the second retaining member 82. In contrast, the movable knife 62 and the second retaining member 82 are connected to the same connecting rod 76, with the support portion 84 and the support shaft 69 located on the needle receiving hole 12 side, i.e., in front of the connecting rod 76. Therefore, when the movable knife 62 rotates about the support shaft 69, the second retaining member 82 also rotates about the support portion 84. When the movable knife 62 moves from the knife standby position P1 to the cutting position P3, the ends of the second retaining member 82 on the insertion portions 88 and 89 side rotate counterclockwise when viewed from above about the support portion 84, moving away from the needle receiving hole 12. Therefore, when the movable knife 62 is located at the cutting position P3, the second holding member 82 moves to the cutting position Q4, and there is no interference between the movable knife 62 and the second holding member 82. Therefore, in the sewing device 1, the upper thread holding mechanism 80 and the cutting mechanism 60 can be compactly configured with a relatively simple structure.

[0084] After the first stitch is sewn and before the second stitch is sewn, the CPU 41 executes the upper thread holding control process (S9) of moving the second holding member 82 from the standby position Q1 to the holding position Q2. In the sewing device 1, after the first stitch is sewn and before the second stitch is sewn, the second holding member 82 is moved from the standby position Q1 to the holding position Q2, thereby being able to hold the upper thread end U.

[0085] In addition to the above-mentioned embodiments, the upper thread holding mechanism and sewing device of the present invention can be modified in various ways. The structures of the sewing device 1 and the upper thread holding mechanism 80 can be modified appropriately. For example, the sewing device 1 may not include at least one of the cloth feeding device 5, the cutting mechanism 60, the fixed cutter 97, and the display unit 13. The structure, shape, size, and configuration of the first holding member 81 and the second holding member 82 can be modified appropriately. The first holding portion 86 and the second holding portion 87 can also be an integral member. At least one of the first holding portion 86 and the second holding portion 87 can also not be formed with the insertion portion 88 or 89 that allows the needle 15 to pass through when the second holding member 82 is in the standby position Q1. The top view shape of the insertion portion 88 or 89 is sufficient as long as it can limit the movement of the upper thread end U in a direction perpendicular to the movement direction of the second holding member 82 during the process of the second holding member 82 moving from the standby position Q1 to the holding position Q2. The top view shape of the insertion portion 88 or 89 can also be, for example, a hole of any shape that penetrates in the vertical direction. The insertion portions 88 and 89 may be of the same shape or different shapes. The first holding member 81 may also be formed with insertion portions such as a notch and a through hole that allow the needle 15 to pass through. The first holding portion 86 may also not be arranged on the same horizontal plane as the movable knife 62. The position of the second holding member 82 may be appropriately changed between the standby position Q1 and the holding position Q2. Alternatively, when the second holding member 82 is in the standby position Q1, the second holding member 82 is separated from the needle hole 12 and the first holding member 81 in the horizontal direction. The support portion 84 may be a cylindrical member as long as it can support the second holding member 82 so that it can rotate. The support portion 84 may also be fixed to the front side opposite to the motor 59 side relative to the needle hole 12.

[0086] The structure of the cutting mechanism 60 can be changed as appropriate. The cutting mechanism 60 may not include at least one of the biasing member 65, the thread clamping portion 66, and the thread loosening portion 68, or it may be that, after the upper thread and the lower thread are cut, the lower thread end D cannot be held between the biasing member 65 and the biasing member 65 in S17. The cutting mechanism 60 may be operated by the power of a motor different from the motor 59 of the upper thread holding mechanism 80, or the movable knife 62 may be moved by the power of the motor 59 via a power transmission member different from the link mechanism 72. The corresponding relationship between the position of the movable knife 62 of the cutting mechanism 60 and the position of the second holding member 82 of the upper thread holding mechanism 80 may be changed as appropriate. The biasing member 65 may also be a structure other than a leaf spring such as a coil spring. The support shaft 69 may also be fixed to the side of the motor 59, i.e., the rear, relative to the needle hole 12.

[0087] The program containing instructions for causing the sewing device 1 to perform the main processing can be stored in the storage device 45 before the CPU 41 executes the program. Therefore, the method for obtaining the program, the acquisition path, and the device for storing the program can also be appropriately changed. Alternatively, the program executed by the CPU 41 can be received from another device via a cable or wireless communication and stored in a non-volatile storage device. The other device includes a PC and a server connected via a network.

[0088] Part or all of the processing performed by the sewing device 1 may also be performed by other electronic devices (such as ASICs) different from the CPU 41. The processing performed by the sewing device 1 may also be distributed processing by multiple electronic devices (such as multiple CPUs). The steps of the processing performed by the sewing device 1 can be changed in order, omitted, and added as needed. The scope of the present invention also includes the following mode: a part or all of the processing is performed by an operating system (OS) running on the sewing device 1 using instructions from the CPU 41.

[0089] In the case where the sewing device 1 does not have a fixed cutter 97, the CPU 41 may determine in S10 whether it is time to release the upper thread end U, and if it is time to release, release the upper thread end U held by the upper thread holding mechanism 80. In this case, the CPU 41 may move the second holding member 82 to the standby position Q1 as a process for releasing the hold of the upper thread end U. The timing when the cutting mechanism 60 releases the lower thread end D and the timing when the upper thread end U is released or cut may be the same as or different from each other. In the case where the sewing device 1 does not have a cutting mechanism 60, the sewing device 1 may omit the processes of S16 and S17. The sewing device 1 may not rotate the second holding member 82 during the processes of S16 and S17.

[0090] Alternatively, the fixed cutter 97 can be positioned below the first holding member 81. When the second holding member 82 moves from the holding position Q2 to the upper thread cutting position Q3, the second holding portion 87 of the second holding member 82 and the fixed cutter 97 overlap in the vertical direction to cut the upper thread. In this case, the upper thread to be cut by the fixed cutter 97 is located downstream of, or below, the position where the upper thread is held by the first and second holding members 81, 82. Furthermore, even if the upper thread is cut, it is held upstream of the cutting portion by the first and second holding members 81, 82. Therefore, even if the upper thread is cut before the third needle is inserted, the upper thread will not escape from the needle hole 12.

[0091] The above modifications may be combined as appropriate within the scope of non-contradiction. The technology disclosed in this specification can be implemented in various forms, for example, in the form of a control method for a sewing device, a computer program for implementing the above method, and a recording medium recording the computer program.

Claims

1. A needle thread holding mechanism, characterized in that: The upper thread holding mechanism has: a first holding member disposed below a needle plate having a needle hole formed therein for inserting a sewing needle of the sewing device; a second holding member that cooperates with the first holding member to hold an end portion of the upper thread, the second holding member comprising a first holding portion provided below the needle plate and above the first holding member, a second holding portion provided below the first holding member, and a support portion that supports the first holding portion and the second holding portion so as to be movable in the horizontal direction; as well as A holding and moving portion having a motor, which uses the power of the motor to move the second holding member along the horizontal direction. The holding and moving portion can move the second holding member to a standby position and a holding position. The standby position is a position when the pinhole is arranged between the first holding member and the second holding member in the horizontal direction. The holding position is a position when the second holding member is separated from the pinhole in the horizontal direction and the second holding member overlaps with the first holding member in the up and down directions.

2. The upper thread holding mechanism according to claim 1, wherein: At least one of the first holding portion and the second holding portion is formed with an insertion portion that allows the sewing needle to pass therethrough when the second holding member is located at the standby position.

3. The upper thread holding mechanism according to claim 1 or 2, characterized in that: The support portion of the second holding member is a pin member perpendicular to the needle plate. The second holding member is rotatably supported by the needle plate via the support portion, and is rotatable about the support portion to the standby position and the holding position.

4. The upper thread holding mechanism according to claim 3, wherein: The support portion is provided on the motor side with respect to the pinhole in a direction from the motor toward the pinhole on a surface parallel to the pin plate.

5. A sewing device, characterized in that: The sewing device has: A needle bar mechanism having a needle bar capable of being fitted with a machine needle at its lower end, such that the needle bar is swung in an up-and-down direction; a needle plate having a needle hole formed thereon for the needle to be inserted therethrough; and The upper thread holding mechanism according to any one of claims 1 to 4.

6. The sewing device according to claim 5, characterized in that The sewing device is provided with a cutting mechanism for cutting the upper thread and the lower thread, and the cutting mechanism is provided with a fixed knife and a movable knife. The fixed knife is fixed to the lower side of the needle plate. The movable knife is configured to be rotatable relative to the fixed knife in the horizontal direction and to be movable between a knife standby position when the movable knife is at a position separated from the fixed knife, a cutting position when the movable knife intersects with the fixed knife to cut the upper thread and the lower thread, and a movable end position on the side opposite to the knife standby position relative to the cutting position. The movable knife moves using the power of the motor.

7. The sewing device according to claim 6, characterized in that: The rotation center of the movable knife is provided on a side of the needle receiving hole opposite to the motor side in a direction from the motor toward the needle receiving hole on a surface parallel to the needle plate.

8. The sewing device according to any one of claims 5 to 7, characterized in that: The sewing device further includes a control device configured to execute a needle thread holding control process for moving the second holding member from the standby position to the holding position after the first stitch is performed and before the second stitch is performed.

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