Cutting mechanism and sewing device

Abstract

To provide a cutting mechanism and a sewing device, which have reduced possibility that a bobbin thread end is caught in a stitch than before.SOLUTION: A cutting mechanism 60 has a stationary blade 61, an energizing member, a movable blade 62, and a blade moving part. The stationary blade 61 is fixed to a lower side of a needle plate 11. The energizing member is fixed to the lower side of the needle plate 11. The movable blade 62 is disposed so as to be horizontally rotatable with respect to the stationary blade 61. The movable blade 62 has a thread nipping part 66 and a thread releasing part 68. The thread nipping part 66 can nip a bobbin thread end of a bobbin thread cut by the movable blade 62. The movable blade 62 has the thread releasing part 68 that cannot nip the bobbin thread end between the thread releasing part and the energizing member. The blade moving part has a motor and turns the movable blade 62 in horizontal direction by power of the motor. The blade moving part moves the movable blade 62 between a blade standby position P1, a releasing position P2, a cutting position P3, and a movable end position P4.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a cutting mechanism of a sewing machine and a sewing machine.

Background Art

[0002] A conventional sewing machine includes a thread cutting mechanism and an upper thread holding mechanism between a needle plate and a rotating bobbin. The thread cutting mechanism has a movable blade and a fixed blade. At the end of sewing, the thread cutting mechanism reciprocates the movable blade horizontally to cut the upper thread extending through the eyelet of the sewing needle and passing through the work cloth, and the lower thread extending from the rotating bobbin. The upper thread holding mechanism includes a first thread holding member and a second thread holding member. When the sewing needle of the first stitch after the start of sewing moves above the needle plate, the second thread holding member rotates to the holding position and cooperates with the first thread holding member to hold the thread end.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional sewing machine, the lower thread end cut by the movable blade may be caught in the newly formed stitch.

[0005] An object of the present invention is to provide a cutting mechanism and a sewing machine that reduce the possibility of the lower thread end being caught in the stitch more than in the prior art.

Means for Solving the Problems

[0006] The cutting mechanism according to claim 1 of the present invention comprises: a fixed blade fixed to the lower side of a needle plate having a needle hole for inserting a sewing needle of a sewing device; a biasing member fixed to the lower side of the needle plate; a movable blade rotatably mounted horizontally relative to the fixed blade, the movable blade having a thread-clamping portion capable of clamping the end of the bobbin thread after cutting with the biasing member and a thread-releasing portion that cannot clamp the end of the bobbin thread with the biasing member; and a blade moving unit having a motor that rotates the movable blade in the horizontal direction with the power of the motor, wherein the movable blade is positioned in front of the fixed blade. The cutting mechanism comprises: a blade standby position in which the thread-holding portion of the movable blade is located at a distance in the horizontal direction and is positioned between the needle plate and the biasing member, facing the biasing member, and the thread-holding portion can hold the end of the lower thread together with the biasing member; a release position in which the thread-releasing portion of the movable blade is positioned between the needle plate and the biasing member, facing the biasing member; a cutting position in which the movable blade intersects with the fixed blade to cut the upper thread and the lower thread; and a blade moving portion that moves the movable blade between the cutting position and a movable end position on the opposite side of the blade standby position. The cutting mechanism of claim 1 can hold the end of the lower thread between the biasing member and the thread-holding portion when the movable blade is in the blade standby position. The cutting mechanism can release the lower thread end from being held between the biasing member and the thread-holding portion when the movable blade is in the release position. The cutting mechanism can use the power of motors that cut the upper and lower threads to grip and release the end of the lower thread.

[0007] The pivot point of the movable blade in the cutting mechanism of claim 2 of the present invention is located on the opposite side of the needle hole from the motor side in the direction from the motor toward the needle hole on a plane parallel to the needle plate. Compared to the case where the pivot point of the movable blade is located on the motor side of the needle hole in the direction from the motor toward the needle hole on a plane parallel to the needle plate, the cutting mechanism of claim 2 allows for greater design freedom on the motor side of the needle hole relative to the needle hole.

[0008] The biasing member of the cutting mechanism according to claim 3 of the present invention is a leaf spring. The cutting mechanism according to claim 3 allows for a relatively simple configuration of the biasing member.

[0009] The thread release portion of the cutting mechanism according to claim 4 of the present invention is an upwardly recessed recess provided on the lower surface of the movable blade, adjacent to the thread clamping portion. The cutting mechanism according to claim 4 allows for a relatively simple configuration of the thread release portion. The cutting mechanism allows for easy adjustment of the position at which the clamping of the lower thread end is released by adjusting the extension range of the thread release portion.

[0010] The sewing apparatus according to claim 5 of the present invention comprises a needle plate having a needle hole for inserting a sewing needle, and a cutting mechanism according to any one of claims 1 to 4. The sewing apparatus according to claim 5 can clamp the end of the lower thread between a biasing member and a thread clamping part when the movable blade of the cutting mechanism is in the blade standby position. The sewing apparatus according to claim 5 can release the lower thread end from being clamped between the biasing member and the thread clamping part when the movable blade is in the release position. The sewing apparatus can clamp and release the end of the lower thread using the power of a motor that cuts the upper and lower threads.

[0011] The sewing apparatus according to claim 6 of the present invention further comprises an upper thread holding mechanism that is driven by the motor and releasably holds the upper thread end of the upper thread that has been passed through the sewing needle on the lower side of the needle plate. The sewing apparatus according to claim 6 can perform both the cutting mechanism and the upper thread holding mechanism with a single motor. The sewing apparatus can suppress problems caused by the upper thread end or lower thread end getting caught in the stitch by holding the lower thread end with the cutting mechanism and the upper thread end with the upper thread holding mechanism.

[0012] The upper thread holding mechanism of the sewing apparatus according to claim 7 of the present invention comprises a first holding member provided on the lower surface of the needle plate, a second holding member rotatably supported on the needle plate by a support and cooperating with the first holding member to hold the end of the upper thread, and a holding movement unit that moves the second holding member in the horizontal direction by the power of the motor, wherein the holding movement unit moves the second holding member to a standby position in which the second holding member is separated from the needle hole and the first holding member in the horizontal direction, and the needle hole is positioned between the first holding member and the second holding member, and to a holding position in which 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 sewing apparatus according to claim 7 has a common power source for the upper thread holding mechanism and the cutting mechanism, so the configuration can be simplified compared to a sewing apparatus in which the power source for the upper thread holding mechanism and the power source for the cutting mechanism are provided separately.

[0013] The support portion of the sewing apparatus according to claim 8 of the present invention is provided on the motor side with respect to the needle hole, in the direction from the motor toward the needle hole on a plane parallel to the needle plate. In the sewing apparatus according to claim 8, if the pivot point of the movable blade of the cutting mechanism is on the opposite side of the needle hole from the motor side with respect to the needle hole, in the direction from the motor toward the needle hole on a plane parallel to the needle plate, the possibility of interference between the upper thread holding mechanism and the cutting mechanism is reduced, and the degree of design freedom on the side of the needle hole opposite to the motor side is increased.

[0014] When the second holding member of the sewing apparatus according to claim 9 of the present invention is in the standby position, the movable blade is in the blade standby position, and when the second holding member is in the holding position, the movable blade and the biasing member grip the end of the lower thread. The sewing apparatus according to claim 9 can synchronize the operation of the upper thread holding mechanism and the cutting mechanism. The sewing apparatus can grip the end of the lower thread with the cutting mechanism when the upper thread holding mechanism is in the standby position and when it is in the holding position.

[0015] The sewing apparatus according to claim 10 of the present invention further comprises a fixed blade fixed to the lower side of the needle plate, the holding and moving part is capable of moving the second holding member to the standby position, the holding position, and an upper thread cutting position in which the upper thread end held by the first holding member and the second holding member is cut by the fixed blade, and when the second holding member is in the upper thread cutting position, the movable blade is in the release position. The sewing apparatus according to claim 10 can synchronize the operation of the upper thread holding mechanism and the cutting mechanism. The sewing apparatus can release the gripping of the lower thread end by the cutting mechanism when the upper thread holding mechanism is in the upper thread cutting position.

[0016] The sewing apparatus according to claim 11 of the present invention further comprises a control device that controls the motor to perform a thread cutting process in which the movable blade is moved from the blade standby position to the movable end position, then to the cutting position to cut the upper thread and the lower thread; a clamping process in which the movable blade is moved from the cutting position to the blade standby position to clamp the lower thread end cut in the thread cutting process between the biasing member and the thread clamping part; and a release process in which the movable blade is moved from the blade standby position to the release position to release the lower thread end clamped in the clamping process. The sewing apparatus according to claim 11 can automatically perform the thread cutting process, the clamping process and the release process. [Brief explanation of the drawing]

[0017] [Figure 1] This is an overall perspective view of sewing machine 1. [Figure 2] This is a perspective view of the cutting mechanism 60 and the upper thread holding mechanism 80. [Figure 3] This is an exploded perspective view of part of the cutting mechanism 60 and part of the upper thread holding mechanism 80. [Figure 4] This is a bottom view of part of the cutting mechanism 60 and part of the upper thread holding mechanism 80. [Figure 5] This is a bottom view of a part of the cutting mechanism 60. [Figure 6] This is a bottom view of the motor 59, the cam plate 70, and links 73 and 74, which are part of the link mechanism 72. [Figure 7] This is a bottom view of a part of the upper thread holding mechanism 80. [Figure 8] Block diagram showing the electrical configuration of the sewing machine 1. [Figure 9] Flowchart of the main process of the sewing machine 1. [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, (B) 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 holding position Q2, and (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 in the upper thread cutting position Q3. [Figure 11] (A) is a bottom view of a part of the cutting mechanism 60 and a part of the upper thread holding mechanism 80 when the second holding member 82 is in the standby position Q1, (B) is a bottom view of a part of the cutting mechanism 60 and a part of the upper thread holding mechanism 80 when the second holding member 82 is in the holding position Q2, and (C) is a bottom view of a part of the cutting mechanism 60 and a part of the upper thread holding mechanism 80 when the second holding member 82 is in the upper thread cutting position Q3. [Figure 12] (A) is a cross-sectional view taken in the arrow viewing direction along the G1-G1 line in Fig. 11(A), (B) is a cross-sectional view taken in the arrow viewing direction along the G2-G2 line in Fig. 11(B), and (C) is a cross-sectional view taken in the arrow viewing direction along the G3-G3 line in Fig. 11(C). [Figure 13] (A) is a cross-sectional view taken in the arrow viewing direction along the F1-F1 line in Fig. 11(A), (B) is a cross-sectional view taken in the arrow viewing direction along the F2-F2 line in Fig. 11(B), and (C) is a cross-sectional view taken in the arrow viewing direction along the F3-F3 line in Fig. 11(C). [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 blade 62 is in the movable end position P4, and (B) is a bottom view of a part of the motor 59, the cam plate 70, and the link mechanism 72 when the movable blade 62 is in the cutting position P3. [Figure 15] (A) is a bottom view of a part of the cutting mechanism 60 and a part of the upper thread holding mechanism 80 when the movable blade 62 is in the movable end position P4, and (B) is a bottom view of a part of the cutting mechanism 60 and a part of the upper thread holding mechanism 80 when the movable blade 62 is in the cutting position P3. [Modes for carrying out the invention]

[0018] Embodiments of the present invention will now be described. The following description will use the left / right, front / back, and up / down directions indicated by arrows in the figures. The left / right direction, front / back direction, and up / down direction of the sewing machine 1 are the X-axis direction, Y-axis direction, and Z-axis direction, respectively.

[0019] Referring to Figure 1, the structure of the sewing machine 1 will be described. The sewing machine 1 can sew in a 360-degree direction by feeding the workpiece 19 in the X-axis and Y-axis directions relative to the sewing needle 15. The workpiece 19 is, for example, cloth, leather, etc. The sewing machine 1 comprises a bed section 2, a leg column section 3, an arm section 4, a fabric feeding device 5, a control section 10 (see Figure 8), and an operating panel 18. The bed section 2 is installed on a sewing machine table 6. The bed section 2 has a work table 7 on its upper front side. The work table 7 has 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 machine 1 has a lower shaft (not shown) and a oscillating vertical bobbin inside the bed section 2. The oscillating vertical bobbin is located below the needle plate 11, and the lower shaft extends in the front-rear direction. The front end of the lower shaft is connected to the oscillating vertical bobbin. The oscillating vertical bobbin houses a bobbin wound with lower thread and oscillates back and forth around the lower shaft.

[0020] The leg column 3 extends upward from the rear of the bed 2. The arm 4 extends forward from the top of the leg column 3 and rotatably supports the main shaft inside. The main shaft extends in the front-rear direction and is connected to the main motor 17 (see Figure 8) located on the rear side inside the arm 4. The connecting rod extends vertically inside the leg column 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 the oscillating vertical bobbin is driven in accordance with the rotation of the main shaft. The sewing machine table 6 has an operating panel 18 on the upper right side. The operating 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 accepts input of various information such as instructions to start sewing.

[0021] The arm portion 4 is equipped with a tip portion 8 at its front end. The lower end of the tip portion 8 faces the upper surface of the needle plate 11. The tip portion 8 supports the needle bar 14 and the presser bar 20 so that they can move up and down. The needle bar 14 extends vertically and protrudes downward from the tip portion 8. A sewing needle 15 is attached to the lower end of the needle bar 14. The sewing needle 15 has an eyelet, and the upper thread is held by passing the upper thread through the eyelet. 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 sewing needle 15 moves up and down and passes through the needle eye 12. The moving sewing needle 15 works in cooperation with the oscillating vertical bobbin to form a stitch in the workpiece 19. The presser bar 20 extends vertically to the left of the needle bar 14 and protrudes downward from the tip portion 8. A presser foot 9 is attached to the lower end of the presser bar 20. The pressing foot 9 intermittently presses down on the workpiece 19 being sewn.

[0022] The fabric feeding device 5 includes an X motor 21 (see Figure 8), a fabric holder 22, a support part 23, a shaft part 24, a Y motor 25 (see Figure 8), etc. The fabric feeding device 5 also includes an X rail, an X moving plate, a Y rail, and a Y moving plate (not shown). The X motor 21 is located on the rear side inside the bed part 2. The X rail extends in the X-axis direction inside the bed part 2 and in front of the X motor 21. The X moving plate is connected to the X rail so as to be movable from side to side and is also connected to the X motor 21. The X moving plate moves from side to side along the X rail by the driving force of the X motor 21. The Y rail is fixed to the upper surface of the X moving plate and extends in the Y-axis direction. The Y rail moves from side to side integrally with the X moving plate. The Y moving plate is connected to the Y rail so as to be movable in the front-rear direction. The fabric holder 22 is fixed to the upper surface of the Y moving plate. The fabric holder 22 moves from side to side integrally with the X moving plate and the Y moving plate, and moves in the front-rear direction integrally with the Y moving plate. Therefore, the cloth holder 22 can move horizontally. The support part 23 is connected to the rear of the pressing arm 32 of the cloth holder 22. The support part 23 can move left and right together with the cloth holder 22. The shaft part 24 extends rearward from the support part 23 to the inside of the leg column part 3 and can move back and forth. The front end of the shaft part 24 is connected to the support part 23 via a slider. The Y motor 25 is installed inside the leg column part 3 and connected to the shaft part 24. When the shaft part 24 moves back and forth by the driving force of the Y motor 25, the support part 23, the cloth holder 22, and the Y moving plate move back and forth as a single unit.

[0023] The fabric holder 22 includes a feed plate 31, a presser arm 32, a pair of connecting parts 33, a presser frame 34, and a pair of air cylinders 35 (only one is shown in Figure 1). The feed plate 31 extends forward from the upper surface of the Y-moving plate and has a clamping frame 36 at its front end. The clamping frame 36 is rectangular in shape in plan view and can support the workpiece 19. The presser arm 32 extends upward from the rear end of the feed plate 31 and then bends forward. The presser arm 32 clamps and fixes the rear end of the feed plate 31 between itself and the upper surface of the Y-moving plate. The tip 37 of the presser arm 32 is roughly rectangular in shape in front view. The pair of connecting parts 33 are aligned horizontally at the tip 37 and can move up and down. The pair of connecting parts 33 support the presser frame 34. The presser frame 34 is roughly rectangular in shape in plan view and faces the clamping frame 36 in the vertical direction. A pair of air cylinders 35 are provided on the left and right sides of the presser arm 32. Each pair of air cylinders 35 is connected to a pair of connecting parts 33. When the pair of air cylinders 35 are driven and the pair of connecting parts 33 move up and down, the presser frame 34 moves up and down between a clamping position and a release position. The clamping position is the position in which the workpiece 19 supported by the clamping frame 36 is pressed from above. The release position is the position in which the presser frame is moved upward away from the workpiece 19. The sewing device 1 can sew in a 360-degree direction by moving the fabric holder 22 that holds the workpiece 19 in the X-axis and Y-axis directions relative to the sewing needle 15.

[0024] As shown in Figure 2, the sewing machine 1 is equipped with a cutting mechanism 60 and an upper thread holding mechanism 80 on the underside of the needle plate 11. The cutting mechanism 60 is driven by the motor 59 and cuts the upper and lower threads at the end of the sewing operation. The upper thread holding mechanism 80 is driven by the motor 59 and holds the upper thread end U (see Figure 12) of the upper thread that has passed through the sewing needle 15 on the underside of the needle plate 11 in a releaseable manner. The upper thread holding mechanism 80 bends and holds the upper thread that has passed under the workpiece 19 with the first stitch at the start of sewing. Therefore, the upper thread holding mechanism 80 prevents the thread from coming out of the sewing needle 15. The sewing machine 1 has the motor 59 fixed to the back side of the bed section 2. The motor 59 is a pulse motor and is the drive source for the cutting mechanism 60 and the upper thread holding mechanism 80.

[0025] As shown in Figures 2 to 5, the cutting mechanism 60 comprises a fixed blade 61, a movable blade 62, a biasing member 65, a support shaft 69, and a moving part 67. As shown in the figures, the fixed blade 61 is fixed to the lower side of the needle plate 11 through which the sewing needle 15 of the sewing device 1 is inserted, and a needle hole 12 is formed. The fixed blade 61 is approximately L-shaped in plan view and is fixed to the lower surface of the needle plate 11 with two screws 611. The fixed blade 61 comprises a blade portion 612. The blade portion 612 is located on the right rear of the fixed blade 61 and extends from the left side of the needle hole 12 toward the front of the needle hole 12.

[0026] The movable blade 62 is provided so as to be able to rotate horizontally relative to the fixed blade 61. The movable blade 62 has a thread handling section 621, a blade section 622, a thread engaging section 623, a thread guide section 624, a thread capturing section 625, a thread clamping section 66, and a thread release section 68, etc. The thread handling section 621 has a tip that is pointed toward the rear and is the part that enters into the upper thread loop formed by the upper thread. The blade section 622 is the end of a circular through hole in the bottom view that penetrates the movable blade 62 in the vertical direction. The thread engaging section 623 is the part that hooks the side of the upper thread loop that extends from the sewing needle 15. The thread guide section 624 is the part that curves between the thread handling section 621 and the thread capturing section 625 on the opposite side of the pin 763 of the link 76 relative to the support shaft 69. The thread guide section 624 guides the side of the upper thread loop that extends from the workpiece 19 to the thread capturing section 625. The thread capturing section 625 is the part that captures the upper thread loop.

[0027] The thread-holding portion 66 is the part of the lower surface of the movable blade 62 that can hold the end of the lower thread D (see Figure 13(A)) after it has been cut by the movable blade 62 between itself and the biasing member 65. The thread-releasing portion 68 is the part of the lower surface of the movable blade 62 that cannot hold the end of the lower thread D between itself and the biasing member 65. The thread-releasing portion 68 is the part of the lower surface of the movable blade 62 that is held between the thread-handling portion 621 and the thread-catching portion 625, the part that is in contact with the thread-catching portion 625, and is an upwardly recessed recess provided adjacent to the thread-holding portion 66. In other words, the thread-holding portion 66 is located below the thread-releasing portion 68.

[0028] Movable blade 62 toInsertion portions 626 and 627 are formed. Insertion portion 626 is a vertically penetrating hole provided at the end of the movable blade 62 opposite to the side where the thread handling portion 621 is provided (the rear end of the movable blade 62 in the position shown in Figure 3). The pin 763 of the link 76, described later, is inserted through the insertion portion 626. Insertion portion 627 is a vertically penetrating hole provided at the center of the movable blade 62 in the longitudinal direction. The support shaft 69 is inserted through the insertion portion 627 and fixed to the lower surface of the needle plate 11, supporting the movable blade 62 so that it can reciprocate and rotate in a horizontal direction parallel to the needle plate 11. The support shaft 69, which is the rotation center of the movable blade 62, is provided on the side opposite to the motor 59 in the front-to-back direction relative to the needle hole 12, in the direction from the motor 59 to the needle hole 12 on a plane parallel to the needle plate 11. The pivot shaft 69 is located to the right of the screw 611.

[0029] As shown in Figure 4, the biasing member 65 is fixed to the underside of the needle plate 11 in front of the needle hole 12 by two screws 651. The biasing member 65 is a bent leaf spring. The biasing member 65 comprises a fixing part 652, a pressing part 653, and guide parts 654 and 655. The fixing part 652 is a plate-like structure parallel to the needle plate 11, extending from the front of the needle hole 12 to the right rear, and is fixed to the needle plate 11 by two screws 651. The pressing part 653 is a U-shaped portion in bottom view, which is bent downward from the left rear end of the fixing part 652 and then bent backward. The pressing part 653 slopes gently downward towards the rear. As shown in Figure 13(A), the guide part 654 is a portion at the rear of the pressing part 653 that slopes downward towards the rear. The guide portion 655 is the part that bends upward from the left end of the guide portion 654. The guide portions 654 and 655 guide the movable blade 62 to move so that it is positioned between the biasing member 65 and the needle plate 11. The biasing member 65 can bias the thread-holding portion 66 of the movable blade 62 upward.

[0030] As shown in Figure 2, the movable unit 67 has a motor 59, which rotates the movable blade 62 horizontally. The movable unit 67 comprises the 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 bed unit 2 (see Figure 1) with its output shaft 98 facing downwards. 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 blade 62 of the cutting mechanism 60 according to the rotation direction and angle of the cam plate 70, cutting the upper and lower threads. The link mechanism 72 drives the second holding member 82 of the upper thread holding mechanism 80 according to the rotation direction and angle of the cam plate 70, holding the upper thread end U at a predetermined time when sewing begins.

[0031] As shown in Figure 6, the cam plate 70 is positioned below the motor 59 and fixed to the tip of the motor 59's output shaft 98. The cam plate 70 is formed in a roughly semicircular shape when viewed from below, with a shaft hole 701 formed in the center. The tip of the motor 59's output shaft 98 is inserted and fixed into the shaft hole 701. The cam plate 70 rotates together with the output shaft 98. The cam plate 70 is equipped with grooved cams 71 in a range of approximately 180 degrees centered on the shaft hole 701. The grooved cams 71 are semicircular in shape when viewed from above and have a groove-like shape that is recessed in the thickness direction on the lower surface of the cam plate 70.

[0032] As shown in Figures 2 and 6, the link mechanism 72 comprises links 73-76 and a roller member 77. Links 73-76 are arranged sequentially from the motor 59 side toward the cutting mechanism 60 side. Link 73 is roughly L-shaped in plan view and is positioned below the cam plate 70. Link 73 rotatably fixes a roller member 77 to the upper side of one end 731. The roller member 77 has a rotation axis extending in the vertical direction. The roller member 77 engages with the groove cam 71 of the cam plate 70. Link 73 has a shaft hole 734 in the central portion 733 which is bent at approximately a right angle between one end 731 and the other end 732. Since the support shaft 735 is inserted into the shaft hole 734, link 73 can rotate around the support shaft 735. . The other end 732 of link 73 is rotatably connected to one end 741 of link 74 via pin 736.

[0033] Link 74 is a rod-shaped member extending in the front-rear direction. The other end 742 of link 74 is fixed to one end 751 of link 75 with a screw 743. Link 75 is a C-shaped plate member that is open to the right when viewed from the front. The other end 752 of link 75 is located above the one end 751 and is fixed to one end 761 of link 76 with a screw 743. The central part 753 of link 75, which extends in the vertical direction, has a support shaft 754 that extends in the vertical direction inserted through it. Link 75 can rotate around the support shaft 754. Link 76 extends in the front-rear direction. As shown in Figures 3 and 4, the other end 762 of link 76 bulges out to the right in a roughly arc shape. The other end 762 of link 76 has pins 763 and 764 that protrude upward. Pin 763 is provided at the front end of link 76 and is inserted into the insertion part 626 of the movable blade 62. The movable blade 62 is connected to link 76 by pin 763 of link 76. Pin 764 is located behind pin 763 and is inserted into the insertion portion 861 of the second retaining member 82 of the upper thread holding mechanism 80, which will be described later. The second retaining member 82 is connected to link 76 by pin 764 of link 76. Link 76 is located below the second retaining member 82 and the movable blade 62.

[0034] The moving part 67, powered by the motor 59, moves the link 76 in the forward and backward directions, thereby rotating the movable blade 62 around the pivot shaft 69 in a horizontal direction parallel to the needle plate 11. In motion The movable part 67 can move the movable blade 62 to the blade standby position P1, release position P2, cutting position P3, and movable end position P4 shown in Figure 5, in response to the drive of the motor 59. In Figure 5, the illustration of members other than the fixed blade 61, movable blade 62, and link 76 is omitted, and the position of the movable blade 62 is shown by the position of the blade portion 622.

[0035] The blade standby position P1 is a position where the movable blade 62 is away from the fixed blade 61, and the thread gripping portion 66 of the movable blade 62 is positioned between the needle plate 11 and the biasing member 65, facing the biasing member 65, and the thread gripping portion 66 is in a position where it can grip the lower thread end D together with the biasing member 65. The release position P2 is a position where the thread release portion 68 of the movable blade 62 is positioned between the needle plate 11 and the biasing member 65, facing the biasing member 65. The cutting position P3 is a position where the movable blade 62 intersects with the fixed blade 61 to cut the upper and lower threads. The movable end position P4 is a position opposite to the cutting position P3 from the blade standby position P1. In other words, the movable end position P4 is in a counterclockwise direction when viewed from below with respect to the cutting position P3, with respect to the pivot shaft 69, and the blade standby position P1 is in a clockwise direction when viewed from below with respect to the cutting position P3, with respect to the pivot shaft 69. On the movement trajectory J1 of the movable blade 62, the cutting position P3 is located between the blade standby position P1 and the movable end position P4, and the release position P2 is located between the blade standby position P1 and the cutting position P3. The main process by which the sewing device 1 moves the movable blade 62 to each position will be described later.

[0036] As shown in Figures 2 to 4 and Figure 7, the upper thread holding mechanism 80 comprises a first holding member 81, a second holding member 82, and a movable part 67. The upper thread holding mechanism 80 of this embodiment further comprises a fixed blade 97. The movable part 67 is common to the upper thread holding mechanism 80 described above. The first holding member 81 is provided below the needle plate 11 through which the sewing needle 15 of the sewing device 1 passes, and through which the needle hole 12 is formed. The first holding member 81 is a plate-shaped member that is long in the left-right direction and extends horizontally parallel to the needle plate 11. The first holding member 81 extends horizontally below the thread guide portion 624 of the movable blade 62. The first holding member 81 is positioned to the left of 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 backward towards the right. As shown in Figure 13(A), the first holding portion 86 of the second holding member 82 is positioned on the same horizontal plane as the movable blade 62. 、 The same horizontal plane refers to any hypothetical horizontal plane that passes 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 overlap in at least part.

[0037] As shown in Figures 2 to 4 and Figure 7, the second retaining member 82 cooperates with the first retaining member 81 to hold the upper thread end U of the upper thread. The second retaining member 82 comprises a first retaining portion 86, a second retaining portion 87, and a support portion 84. The first retaining portion 86 is provided below the needle plate 11 and above the first retaining member 81. The first retaining portion 86 has a plate-like shape that is long in the front-rear direction and has an insertion portion 88 that allows the sewing needle 15 to pass through when the second retaining member 82 is in the standby position Q1 in Figure 7. The first retaining portion 86 has insertion portions 861, 863, and a pair of screw holes 862. The insertion portion 861 is a hole that penetrates vertically and is provided at the end of the first retaining portion 86. The pin 764 of the link 76 is inserted through the insertion portion 861. The insertion portion 863 is a hole that penetrates vertically and is provided in front of the insertion portion 861. The second retaining member 82 is supported by a support portion 84 inserted through the insertion portion 863 of the first retaining portion 86, so as to be rotatable in a horizontal direction parallel to the needle plate 11. The support portion 84 is a pin member provided perpendicular to the needle plate 11. The second retaining member 82 is supported by a support portion 84 inserted through the first retaining portion 86, so as to be rotatable in a horizontal direction parallel to the needle plate 11. The support portion 84 is provided behind the needle hole 12, that is, in the direction from the motor 59 toward the needle hole 12 on a plane parallel to the needle plate 11, in the front-rear direction in this embodiment, on the motor 59 side relative to the needle hole 12. The distance between the center of the pivot shaft 69 and the center of the pin 764 is shorter than the distance E2 between the center of the support portion 84 and the center of the pin 764. Therefore, the amount of rotation of the movable blade 62 with respect to the amount of movement of the link 76 is greater than the amount of rotation of the second retaining member 82 with respect to the amount of movement of the link 76.

[0038] The second retaining portion 87 is plate-shaped and elongated in the front-rear direction, and is positioned below the first retaining member 81. The length of the second retaining portion 87 in the front-rear direction is shorter than the length of the first retaining portion 86 in the front-rear direction. The second retaining portion 87 has an insertion portion 89 that allows the sewing needle 15 to pass through when the second retaining member 82 is in the standby position Q1. The second retaining portion 87 has two holes 872 that penetrate in the left-right direction. When the second retaining portion 87 is superimposed on the first retaining portion 86, it is fixed to the lower surface of the first retaining portion 86 by screws 871 inserted through the holes 872. At this time, the second retaining portion 87 is positioned in front of the support portion 84. In this embodiment, the insertion portions 88 and 89 are notches that open to the left, and the contours of the insertion portions 88 and 89 in plan view overlap each other. The insertion portions 88 and 89 are formed on the second retaining member 82 on the side opposite to the insertion portion 861 side relative to the support portion 84. The second retaining portion 87 is immovable relative to the first retaining portion 86 and moves horizontally together with the first retaining portion 86. As shown in Figure 12(A), the thicknesses of the first retaining portion 86 and the second retaining portion 87 are greater than the thickness of the first retaining member 81. The thickness of the first retaining portion 86 is greater than the thickness of the second retaining portion 87.

[0039] As shown in Figure 3, the fixed scalpel 97 is fixed to the lower side of the needle plate 11, which has a needle hole 12 through which the sewing needle 15 is inserted. The fixed scalpel 97 has a blade portion 96. The blade portion 96 is located to the right of the fixed blade 61 and is positioned to the left of the needle hole 12. As shown in Figure 12(A), the right end of the blade portion 96 is inclined downward to the right. The fixed scalpel 97 has a pair of front and rear holes 971 that penetrate in the vertical direction. The fixed scalpel 97 is located above the first retaining member 81. The fixed scalpel 97 is fixed 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.

[0040] The movable part 67 connects to the second retaining member 82 by inserting the pin 764 of the link 76 into the insertion portion 861 of the second retaining member 82. The movable part 67 moves the link 76 back and forth using the power of the motor 59, thereby rotating the second retaining member 82 around the support portion 84 in a horizontal direction parallel to the needle plate 11. In motionIn other words, the movable part 67 can move the movable blade 62 and the second holding member 82. Specifically, the movable part 67 moves the second holding member 82 to the standby position Q1, the holding position Q2, the upper thread cutting position Q3, the cutting position Q4, and the movable end position Q5, as shown in Figure 7. In Figure 7, the illustration of members other than the first holding part 86, the second holding part 87, the support part 84, the fixed blade 97, and the link 76 is omitted, and the position of the second holding member 82 is shown as the position of a virtual circle inscribed in the arc-shaped right end portion of the insertion part 89.

[0041] The standby position Q1 is the position in the horizontal direction where the needle hole 12 is positioned between the first holding member 81 and the second holding member 82. The holding position Q2 is the position in the horizontal direction where the second holding member 82 is separated from the needle hole 12 and the second holding member 82 overlaps with the first holding member 81 in the vertical direction. The upper thread cutting position Q3 is the position where the upper thread end U held by the first holding member 81 and the second holding member 82 is cut by the fixed scalpel 97. On the movement trajectory 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 correspond to the cutting position P3 and the movable end position P4 of the movable blade 62, respectively. The main process by which the sewing device 1 moves the second holding member 82 to each position will be described later.

[0042] The electrical configuration of the sewing machine 1 will be explained with reference to Figure 8. The control unit 10 of the sewing machine 1 includes a CPU 41, ROM 42, RAM 43, storage device 45, I / O interface (hereinafter referred to as I / O) 46, drive circuits 51-56, etc. The CPU 41 controls the operation of the sewing machine 1. The CPU 41 is connected to the ROM 42, RAM 43, storage device 45, and I / O 46. The ROM 42 stores programs for executing various processes, such as the main process described later (see Figure 9). The RAM 43 temporarily stores various information. The storage device 45 is non-volatile and stores sewing information, etc. Sewing information is information including needle drop points.

[0043] I / O46 is connected to drive circuits 51-56 and 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 57 is connected to motor 59. X motor 21, Y motor 25, and motor 59 are pulse motors. Drive circuit 54 is connected to a pair of air cylinders 35. Drive circuit 55 is connected to the display unit 13. The CPU 41 controls the main motor 17, X motor 21, Y motor 25, and the pair of air cylinders 35 by controlling drive circuits 51-54. The CPU 41 controls the display unit 13 by controlling drive circuit 56. The input unit 16 detects information entered by the operator and outputs the detection result to the CPU 41 via I / O46.

[0044] Encoders 91-93 are connected to the main motor 17, X motor 21, and 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 91-93 output the detection results to the CPU 41 via I / O 46.

[0045] Referring to Figures 9 to 15, the main processing performed in sewing machines 1 of specific examples 1 and 2, in which the upper thread cutting time differs from one another, will be explained. In the main processing, a process is performed to form stitches on the workpiece 19 according to the sewing pattern. When the power to the sewing machine 1 is turned ON, the CPU 41 starts the main processing. When the power to the sewing machine 1 is turned ON, the CPU 41 reads the program for executing the main processing, which is stored in the program storage area of ​​the ROM 42, into the RAM 43. The CPU 41 executes the following steps according to the instructions contained in the program read into the RAM 43. Hereinafter, each step will be abbreviated as S. Various parameters necessary for executing the main processing are stored in the storage device 45. Various data obtained during the main processing are stored in the RAM 43 as appropriate. The upper thread cutting time only needs to be set before the execution of the main processing, and may be set by the operator or automatically according to sewing conditions such as the type and thickness of the workpiece 19.

[0046] As shown in Figure 9, the CPU 41 determines whether it has detected the origin detection instruction (S1). The operator inputs the origin detection instruction by operating the input unit 16. If the origin detection instruction is not detected (S1: NO), the CPU 41 returns to processing S1. If the origin detection instruction is detected (S1: YES), the CPU 41 performs the origin detection (S2) and then raises the presser foot 9 (S3).

[0047] The operator places the workpiece 19 to be sewn between the fabric holders 22 and operates the input unit 16 to input a command to lower the presser foot 9. The CPU 41 determines whether it has detected the command to lower the presser foot 9 (S4). If the command to lower is not detected (S4: NO), the CPU 41 returns to processing S4. If the command to lower is detected (S4: YES), the CPU 41 lowers the presser foot 9 (S5). As shown in Figure 10(A), the roller member 77 provided at one end 731 of the link 73 of the movable part 67 is located at the left end of the groove cam 71. As shown in Figure 11(A), the movable blade 62 of the cutting mechanism 60 is located at the blade standby position P1, and the second holding member 82 of the upper thread holding mechanism 80 is located at the standby position Q1. In other words, when the second holding member 82 is at the standby position Q1, the movable blade 62 is at the blade standby position P1. In a bottom view, the first retaining member 81 and the second retaining member 82 partially overlap in the vertical direction. In a bottom view, the needle hole 12 is surrounded by the first retaining member 81 and the second retaining member 82. The blade portion 622 of the movable blade 62 is located near the boundary between the guide portion 654 and the pressing portion 653. As shown in Figure 12(A), the second retaining 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 hole 12, is surrounded by the first retaining member 81 and the second retaining member 82. As shown in Figure 13(A), the thread clamping portion 66 of the movable blade 62 of the cutting mechanism 60 clamps the lower thread end D in the vertical direction together with the biasing member 65. The upper end of the pressing portion 653 of the biasing member 65 abuts against the thread clamping portion 66 of the movable blade 62.

[0048] The CPU 41 determines whether it has detected a sewing instruction (S6). The operator inputs a sewing instruction by operating the input unit 16. If no sewing instruction is detected (S6: NO), the CPU 41 returns to processing S6. If a sewing instruction is detected (S6: YES), the CPU 41 drives the main motor 17 to start sewing the sewing pattern (S7). Based on the detection result of the encoder 91, the CPU 41 determines whether it is time to hold the upper thread (S8). In this embodiment, the time to hold the upper thread of the sewing device 1 is set after sewing the first stitch and before sewing the second stitch. If it is not time to hold the upper thread (S8: NO), the CPU 41 returns to processing S8. If it is time to hold the upper thread (S8: YES), the CPU 41 executes an upper thread holding control process to move the second holding member 82 from the standby position Q1 to the holding position Q2 (S9).

[0049] The CPU 41 drives the motor 59, rotating the output shaft 98 of the motor 59 clockwise from the origin to the position shown in Figure 10(B) when viewed from below. As shown in Figure 10(B), the roller member 77 moves to a position rotated counterclockwise relative to the left end of the groove cam 71 when viewed from below. The link 73 rotates counterclockwise when viewed from below around the pivot shaft 735, moving links 74 to 76. As shown in Figure 11(B), the movable blade 62 of the cutting mechanism 60 moves behind the blade standby position P1, and the second retaining member 82 of the upper thread holding mechanism 80 moves from the standby position Q1 to the holding position Q2. In the horizontal direction, the second retaining member 82 is separated from the needle hole 12, and the second retaining member 82 overlaps with the first retaining member 81 in the vertical direction. As shown in Figure 12(B), the upper thread holding mechanism 80 holds the upper thread end U in a state where it is bent in an S-shape in a side view between the first holding member 81 and the second holding member 82. As shown in Figure 13(B), the thread clamping portion 66 of the movable blade 62 of the cutting mechanism 60 maintains a state where it clamps the lower thread end D in the vertical direction together with the biasing member 65.

[0050] The CPU 41 determines whether it is time to cut the upper thread based on the detection result of the encoder 91 (S10). In this embodiment, the time to cut the upper thread of the sewing machine 1 can be set after S9. In specific example 1, the time to cut the upper thread is set after the upper thread holding control process and before the second stitch is dropped. In specific example 2, the time to cut the upper thread is set at a predetermined time after the upper thread holding control process and after the second stitch is dropped. The predetermined time in specific example 2 can be set as appropriate, and in this example it is after the third stitch is dropped and before the fourth stitch is dropped. If it is not time to cut the upper thread (S10: NO), the CPU 41 returns to processing S10. Upper thread Cutting When the time is right (S10: YES), the CPU 41 controls the motor 59 to perform an upper thread cutting process that moves the second holding member 82 from the holding position Q2 to the upper thread cutting position Q3 after S9 (S12). The CPU 41 controls the motor 59 to move the movable blade 62 from the blade standby position P1 to the release position P2 and performs a release process that releases the lower thread end D that was held in the previous main process S17 (S12).

[0051] The CPU 41 drives the motor 59, rotating the output shaft 98 of the motor 59 clockwise in a bottom view from the position shown in Figure 10(B) to the position shown in Figure 10(C). As shown in Figure 10(C), the roller member 77 moves to a position rotated counterclockwise relative to the position shown in Figure 10(B) in a bottom view. The link 73 rotates counterclockwise in a bottom view around the pivot shaft 735, moving links 74 to 76. As shown in Figure 11(C), the movable blade 62 of the cutting mechanism 60 moves to the release position P2, and the second retaining member 82 of the upper thread holding mechanism 80 moves from the holding position Q2 to the upper thread cutting position Q3. In the horizontal direction, the second retaining member 82 is separated from the needle hole 12, and the state in which the second retaining member 82 overlaps the first retaining member 81 in the vertical direction is maintained. The second retaining member 82 overlaps the blade portion 96 of the fixed scalpel 97 vertically. When the movable blade 62 of the cutting mechanism 60 is in a position within the range from the blade standby position P1 to the release position P2, the thread handling portion 621 of the movable blade 62 is located in front of the needle hole 12.

[0052] As shown in Figure 12(C), the upper thread holding mechanism 80 maintains the upper thread end U bent in an S-shape in a side view between the first holding member 81 and the second holding member 82, while the first holding portion 86 of the second holding member 82 overlaps with the fixed scalpel 97 in the vertical direction. As a result, the upper thread end U is cut by the fixed scalpel 97. When the second holding member 82 moves from the holding position Q2 to the upper thread cutting position Q3, the first holding member 81 and the second holding member 82 continue to hold the upper thread end U. Therefore, the upper thread end U is cut by the fixed scalpel 97 while being held by the first holding member 81 and the second holding member 82. The position where the upper thread is cut by the fixed scalpel 97 is upstream of the position where the first holding member 81 and the second holding member 82 hold the upper thread, i.e., the upper portion. As shown in Figure 13(C), the thread release portion 68 of the movable blade 62 of the cutting mechanism 60 faces the pressing portion 653 of the biasing member 65, separated vertically. The thread clamping portion 66 is moved to a retracted state from the pressing portion 653 of the biasing member 65, and the state in which it clamps the lower thread end D vertically together with the biasing member 65 is released. As a result, the upper thread end U, which was held by the upper thread holding mechanism 80 at the start of sewing, is cut near the needle hole 12 and released, and the lower thread end D, which was clamped by the cutting mechanism 60, is released.

[0053] The CPU 41 drives the motor 59 to move the movable blade 62 of the cutting mechanism 60 to the blade standby position P1 and the second holding member 82 of the upper thread holding mechanism 80 to the standby position Q1 (S13). The CPU 41 rotates the output shaft 98 of the motor 59 counterclockwise when viewed from the bottom, from the position shown in Figure 10(C) to the position shown in Figure 10(A).

[0054] The CPU 41 determines whether the next needle drop operation of the sewing needle 15 is the final needle operation (S14). The CPU 41 counts the number of needle drops for the sewing pattern currently being sewn and stores it in the RAM 43. Therefore, the CPU 41 can determine whether the next needle drop operation is the final needle operation by referring to the sewing information of the sewing pattern stored in the ROM 42. If it is not the final needle operation (S14: NO), the CPU 41 returns to S14 and continues the sewing operation. If it is the final needle operation (S14: YES), the CPU 41 stops the main motor 17 (S15).

[0055] The CPU 41 controls the motor 59 to move the movable blade 62 from the blade standby position P1 to the movable end position P4, then to the cutting position P3 to perform a thread cutting process that cuts the upper and lower threads (S16). The CPU 41 drives the motor 59 and rotates the output shaft 98 of the motor 59 clockwise in a bottom view from the position shown in Figure 10(A) to the position shown in Figure 14(A), moving the movable blade 62 from the blade standby position P1 to the movable end position P4. As shown in Figure 14(A), the roller member 77 moves to the right end of the groove cam 71 (the end opposite to the left end of the groove cam 71 in Figure 10(A)). The link 73 rotates counterclockwise in a bottom view around the support shaft 735, moving links 74 to 76. As shown in Figure 15(A), the movable blade 62 of the cutting mechanism 60 moves to the movable end position P4. The blade portion 622 of the movable blade 62 is located behind the support shaft 69 and behind the needle hole 12. Both the thread gripping portion 66 and the thread release portion 68 of the movable blade 62 are positioned retracted from the biasing member 65. A portion of the movable blade 62 passes above the first holding member 81 in the process of moving from the blade standby position P1 to the movable end position P4. The second holding member 82 of the upper thread holding mechanism 80 moves to the movable end position Q5. In the horizontal direction, the second holding member 82 is separated from the needle hole 12, and the second holding member 82 does not overlap with either the first holding member 81 or the fixed blade 97 in the vertical direction. The thread handling portion 621 of the movable blade 62 of the cutting mechanism 60 is located behind the support shaft 69 and behind the needle hole 12. The thread handling 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.

[0056] The CPU 41 drives the motor 59, rotating the output shaft 98 of the motor 59 counterclockwise in a bottom view from the position shown in Figure 14(A) to the position shown in Figure 14(B), moving the movable blade 62 from the movable end position P4 to the cutting position P3. As shown in Figure 14(B), the roller member 77 moves to a position that is relatively clockwise in a bottom view from the right end of the groove cam 71. The link 73 rotates clockwise in a bottom view around the pivot shaft 735 from the position shown in Figure 14(A), moving links 74 to 76. As shown in Figure 15(B), the movable blade 62 of the cutting mechanism 60 moves to the cutting position P3. The blade portion 622 of the movable blade 62 is positioned to overlap the needle hole 12 vertically. The front parts of the thread gripping portion 66 and thread release portion 68 of the movable blade 62 are positioned to be retracted from the biasing member 65. The second retaining member 82 of the upper thread holding mechanism 80 moves to the cutting position Q4. In the horizontal direction, the second retaining member 82 is separated from the needle hole 12, and the second retaining member 82 does not overlap with either the first retaining member 81 or the fixed blade 97 in the vertical direction. When the movable blade 62 of the cutting mechanism 60 is in a position within the range from the movable end position P4 to the cutting position P3, the thread handling portion 621 of the movable blade 62 is located behind the needle hole 12.

[0057] The CPU 41 controls the motor 59 to move the movable blade 62 from the cutting position P3 to the blade standby position P1, and performs a clamping process in which the lower thread end D cut in the thread cutting process is clamped between the biasing member 65 and the thread clamping part 66 (S17). The CPU 41 drives the motor 59 and rotates the output shaft 98 of the motor 59 counterclockwise in a bottom view from the position shown in Figure 14(B) to the position shown in Figure 10(A), moving the movable blade 62 from the cutting position P3 to the blade standby position P1. Link 73 rotates clockwise in a bottom view around the pivot shaft 735 from the position shown in Figure 14(B), moving links 74 to 76. As the movable blade 62 moves from the cutting position P3 to the blade standby position P1, it positions the bobbin thread end D cut in S16 onto the thread clamping portion 66, and is guided by the guide portions 654 and 655 of the biasing member 65, so that the thread clamping portion 66 is positioned between the biasing member 65 and the needle plate 11. As a result, as shown in Figure 13(A), when the movable blade 62 moves from the cutting position P3 to the blade standby position P1, the bobbin thread end D is clamped by the thread clamping portion 66 of the movable blade 62 and the pressing portion 653 of the biasing member 65. The bobbin thread end D is clamped by the thread clamping portion 66 of the movable blade 62 and the pressing portion 653 of the biasing member 65 until the next main process S12 is executed. The CPU 41 then completes the main process.

[0058] In the above embodiment, the sewing device 1, needle plate 11, needle hole 12, sewing needle 15, and CPU 41 are examples of the sewing device, needle plate, needle hole, sewing needle, and control device of the present invention, respectively. Cutting mechanism 60, motor 59, fixed blade 61, movable blade 62, support shaft 6 9The biasing member 65, thread clamping part 66, and thread release part 68 are examples of the cutting mechanism, motor, fixed blade, movable blade, pivot center, biasing member, thread clamping part, and thread release part of the present invention, respectively. The moving part 67 is an example of the blade moving part and the holding moving part. The upper thread holding mechanism 80, first holding member 81, second holding member 82, support part 84, and fixed scalpel 97 are examples of the upper thread holding mechanism, first holding member, second holding member, support part, and fixed scalpel of the present invention, respectively. The blade standby position P1, release position P2, cutting position P3, movable end position P4, standby position Q1, holding position Q2, upper thread cutting position Q3, upper thread end U, and lower thread end D are examples of the blade standby position, release position, cutting position, movable end position, standby position, holding position, upper thread cutting position, upper thread end, and lower thread end of the present invention, respectively. The processes in S16 and S17 are examples of thread cutting processes. The process in S17 is an example of clamping processes. The process in S12 is an example of a deallocation process.

[0059] The sewing device 1 of the above embodiment comprises a cutting mechanism 60 including a fixed blade 61, a biasing member 65, a movable blade 62, and a moving part 67. The fixed blade 61 is fixed to the lower side of a needle plate 11 through which a needle hole 12 for inserting the sewing needle 15 of the sewing device 1 is formed. The biasing member 65 is fixed to the lower side of the needle plate 11. The movable blade 62 is provided so as to be able to rotate horizontally relative to the fixed blade 61. The movable blade 62 includes a thread gripping part 66 and a thread release part 68. The thread gripping part 66 can grip the end of the bobbin thread D after it has been cut by the movable blade 62 between itself and the biasing member 65. The movable blade 62 has a thread release part 68 that cannot grip the end of the bobbin thread D between itself and the biasing member 65. The moving part 67 has a motor 59, and the power of the motor 59 rotates the movable blade 62 horizontally. The moving unit 67 moves the movable blade 62 between the blade standby position P1, the release position P2, the cutting position P3, and the movable end position P4. 。The blade standby position P1 is a position where the movable blade 62 is horizontally separated from the fixed blade 61, and the thread gripping portion 66 of the movable blade 62 is positioned between the needle plate 11 and the biasing member 65, facing the biasing member 65, and the thread gripping portion 66 is capable of gripping the lower thread end D together with the biasing member 65. The release position P2 is a position where the thread release portion 68 of the movable blade 62 is positioned between the needle plate 11 and the biasing member 65, facing the biasing member 65. The cutting position P3 is a position where the movable blade 62 intersects with the fixed blade 61 to cut the upper and lower threads. The movable end position P4 is a position opposite to the cutting position P3 from the blade standby position P1. The cutting mechanism 60 can grip the lower thread end D with the biasing member 65 and the thread gripping portion 66 when the movable blade 62 is in the blade standby position P1. The cutting mechanism 60 can release the bobbin thread end D from being gripped by the biasing member 65 and the thread clamping part 66 when the movable blade 62 is in the release position P2. The cutting mechanism 60 can grip and release the bobbin thread end D using the power of the motor 59 that cuts the upper and lower threads.

[0060] The pivot shaft 6 is the rotation center of the movable blade 62. 9 It is located on the opposite side of the needle hole 12 from the motor 59 side, that is, in front of the needle hole 12. The cutting mechanism 60 is a pivot shaft 6 which is the rotation center of the movable blade 62. 9 However, compared to the case where the pinhole 12 is on the motor 59 side, this design allows for greater design flexibility on the motor 59 side relative to the pinhole 12.

[0061] The biasing member 65 is a leaf spring. The cutting mechanism 60 allows for easy adjustment of the position and range of contact between the biasing member 65 and the thread-holding portion 66 of the movable blade 62, and the configuration of the biasing member 65 can be made relatively simple.

[0062] The thread release section 68 is an upwardly recessed area located on the lower surface of the movable blade 62, adjacent to the thread clamping section 66. The cutting mechanism 60 allows for a relatively simple configuration of the thread release section 68. The cutting mechanism 60 allows for easy adjustment of the position at which the clamping of the lower thread end D is released by adjusting the extension range of the thread release section 68.

[0063] The sewing device 1 comprises a needle plate 11 and a cutting mechanism 60. The needle plate 11 has a needle hole 12 through which a sewing needle 15 is inserted. When the movable blade 62 of the cutting mechanism 60 is in the blade standby position P1, the sewing device 1 can clamp the end of the lower thread D with the biasing member 65 and the thread clamping part 66. When the movable blade 62 is in the release position P2, the sewing device 1 can release the lower thread end D from being clamped by the biasing member 65 and the thread clamping part 66. The sewing device 1 can clamp and release the lower thread end D using the power of a motor 59 that cuts the upper and lower threads.

[0064] The upper thread holding mechanism 80 is driven by the motor 59 and releasably holds the upper thread end U of the upper thread that has been passed through the sewing needle 15 on the underside of the needle plate 11. The sewing device 1 can operate both the cutting mechanism 60 and the upper thread holding mechanism 80 with a single motor 59. The sewing device 1 can suppress problems caused by the upper thread end U or lower thread end D getting caught in the stitch by holding the lower thread end D with the cutting mechanism 60 and holding the upper thread end U with the upper thread holding mechanism 80.

[0065] The upper thread holding mechanism 80 comprises a first holding member 81, a second holding member 82, and a moving part 67. The first holding member 81 is provided on the lower surface of the needle plate 11. The second holding member 82 is rotatably supported on the needle plate 11 by a vertical support part 84 and cooperates with the first holding member 81 to hold the upper thread end U. The moving part 67 moves the second holding member 82 horizontally with the power of the motor 59. The moving part 67 moves the second holding member 82 to a standby position Q1 and a holding position Q2. The standby position Q1 is a position in the horizontal direction where the needle hole 12 is located between the first holding member 81 and the second holding member 82. The holding position Q2 is a position in the horizontal direction where the second holding member 82 is separated from the needle hole 12 and the second holding member 82 overlaps the first holding member 81 in the vertical direction. Since the sewing machine 1 shares power for the upper thread holding mechanism 80 with that of the cutting mechanism 60, its configuration is simpler compared to a sewing machine 1 in which the power for the upper thread holding mechanism 80 and the power for the cutting mechanism 60 are provided separately.

[0066] The support portion 84 is located on the motor 59 side relative to the needle hole 12, in the direction from the motor 59 to the needle hole 12, on a plane parallel to the needle plate 11. The sewing device 1 has a support shaft 6 for the movable blade 62 of the cutting mechanism 60. 9 However, if the needle hole 12 is on the opposite side from the motor 59, the possibility of the upper thread holding mechanism 80 interfering with the cutting mechanism 60 is reduced, and the design freedom on the side of the needle hole 12 opposite to the motor 59 is increased.

[0067] When the second holding member 82 is in the standby position Q1, the movable blade 62 is in the blade standby position P1. When the second holding member 82 is in the holding position Q2, the movable blade 62 and the biasing member 65 grip the lower thread end D. The sewing device 1 can synchronize the operation of the upper thread holding mechanism 80 and the cutting mechanism 60. The sewing device 1 can grip the lower thread end D with the cutting mechanism 60 when the upper thread holding mechanism 80 is in the standby position Q1 and when it is in the holding position Q2.

[0068] The sewing machine 1 includes a fixed blade 97. The fixed blade 97 is fixed to the underside of the needle plate 11. The movable part 67 can move the second holding member 82 to a standby position Q1, a holding position Q2, and an upper thread cutting position Q3, where the upper thread end U held by the first holding member 81 and the second holding member 82 is cut by the fixed blade 97. When the second holding member 82 is in the upper thread cutting position Q3, the movable blade 62 is in the release position P2. The sewing machine 1 can synchronize the operation of the upper thread holding mechanism 80 and the cutting mechanism 60. When the upper thread holding mechanism 80 is in the upper thread cutting position Q3, the sewing machine 1 can release the gripping of the lower thread end D by the cutting mechanism 60.

[0069] The CPU 41 controls the motor 59 to move the movable blade 62 from the blade standby position P1 to the movable end position P4, then to the cutting position P3 to perform a thread cutting process (S16, S17) in which the upper and lower threads are cut. The CPU 41 controls the motor 59 to move the movable blade 62 from the cutting position P3 to the blade standby position P1 and performs a clamping process (S17) in which the lower thread end D cut in the thread cutting process is clamped between the biasing member 65 and the thread clamping part 66. The CPU 41 controls the motor 59 to move the movable blade 62 from the blade standby position P1 to the release position P2 and performs a release process (S12) in which the lower thread end D clamped in the clamping process is released. The sewing device 1 can automatically perform the thread cutting process, the clamping process and the release process.

[0070] The cutting mechanism and sewing apparatus of the present invention can be modified in various ways beyond the embodiments described above. The configurations of the sewing apparatus 1 and the cutting mechanism 60 may be changed as appropriate. For example, the sewing apparatus 1 may not include at least one of the fabric feeding device 5, the upper thread holding mechanism 80, the fixed knife 97, or the display unit 13. The biasing member 65 may be a configuration other than a leaf spring, such as a coil spring. The support shaft 69 may be fixed on the motor 59 side, i.e., rearward, relative to the needle hole 12, in the direction from the motor 59 on a plane parallel to the needle plate 11 toward the needle hole 12.

[0071] The configuration of the upper thread holding mechanism 80 may be modified as appropriate. The configuration, shape, size, and arrangement of the first holding member 81 and the second holding member 82 may be modified as appropriate. The first holding part 86 and the second holding part 87 may be an integrated member, or the second holding member 82 may not have the second holding part 87, and the upper thread end U may be sandwiched between the first holding member 81 and the second holding member 82 from above. The insertion parts 88 and 89 may be omitted, and the planar shape of the insertion parts 88 and 89 may be, for example, holes of any shape that penetrate in the vertical direction. The insertion parts 88 and 89 may have the same shape as each other, or they may have different shapes as each other. The first holding member 81 may have insertion parts such as notches and through holes that allow the sewing needle 15 to pass through. The first holding part 86 does not have to be provided on the same horizontal plane as the movable blade 62. The positions of the second holding member 82, standby position Q1 and holding position Q2, may be changed as appropriate. When the second retaining member 82 is in the standby position Q1, the second retaining member 82 may be separated from the needle hole 12 and the first retaining member 81 in the horizontal direction. The upper thread holding mechanism 80 may be powered by a motor other than the motor 59 of the cutting mechanism 60, or the motor 59 may power the second retaining member 82 via a power transmission member other than the link mechanism 72. The correspondence between the position of the movable blade 62 of the cutting mechanism 60 and the position of the second retaining member 82 of the upper thread holding mechanism 80 may be changed as appropriate. The support part 84 only needs to be able to rotatably support the second retaining member 82 and may be a cylindrical member. The support part 84 may be fixed on the side opposite to the motor 59 side of the needle hole 12, i.e., in front of it.

[0072] The program containing the commands for the sewing machine 1 to perform its main processing only needs to be stored in the storage device 45 before the CPU 41 executes the program. Therefore, the method of acquiring the program, the acquisition path, and the device that stores the program can each be changed as appropriate. The program executed by the CPU 41 may be received from another device via cable or wireless communication and stored in a non-volatile storage device. Other devices include, for example, a PC and a server connected via a network.

[0073] Some or all of the processing performed by the sewing machine 1 may be performed by an electronic device other than the CPU 41 (e.g., an ASIC). The processing performed by the sewing machine 1 may be distributed among multiple electronic devices (e.g., multiple CPUs). The order of each step of the processing performed by the sewing machine 1 can be changed, steps can be omitted, or steps can be added as needed. The scope of the present invention also includes embodiments in which an operating system (OS) or the like running on the sewing machine 1 performs some or all of each process at the command of the CPU 41.

[0074] If the sewing device 1 does not have a fixed knife 97, in S10 the CPU 41 may determine whether it is time to release the upper thread end U, and if it is time to release, it may release the upper thread holding mechanism 80 from holding the upper thread end U. In this case, the CPU 41 may move the second holding member 82 to the standby position Q1 as a process to release the upper thread end U. The time when the upper thread holding mechanism 80 releases the lower thread end D and the time when it releases or cuts the upper thread end U may be the same or different. If the sewing device 1 does not have an upper thread holding mechanism 80, the sewing device 1 may omit the processes in S8 and S9. The clamping process in S17 may be performed separately from the process of cutting the upper and lower threads in S17. The CPU 41 does not have to rotate the second holding member 82 in the processes of S16 and S17.

[0075] The fixed blade 97 may be positioned below the first holding member 81, and 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 blade 97 may overlap vertically to cut the upper thread. In this case, the position where the upper thread is cut by the fixed blade 97 is downstream of the position where the first holding member 81 and the second holding member 82 hold the upper thread, i.e., below it. Furthermore, even if the upper thread is cut, it is held upstream of the cutting point by the first holding member 81 and the second holding member 82, so even if the upper thread cutting process is performed before the third stitch falls, there is no risk of the upper thread coming out of the needle eye 12.

[0076] The above modifications may be combined as appropriate, provided they are consistent. The technologies disclosed herein can be implemented in various forms, for example, as a method for controlling a sewing machine, a computer program for implementing the above method, and a recording medium on which the computer program is stored. [Explanation of symbols]

[0077] 1:Sewing device 11: Needle Plate 12: Needle hole 15: Sewing needle 41: CPU 59: Motor 60: Cutting mechanism 61: Fixed blade 62: Movable blade 64: Support shaft 65: Biasing member 66: Thread clamping section 67: Mobile Unit 68: Thread release section 80: Upper thread holding mechanism 81: First retaining member 82: Second retaining member 84: Support part 97: Fixed scalpel D:Bobbin thread end P1: Blade standby position P2: Release position P3: Cutting position P4: Movable end position Q1:Standby position Q2: Holding position Q3: Upper thread cutting position U: Upper thread end

Claims

1. A fixed blade is fixed to the underside of the needle plate, which has a needle hole formed through which the sewing needle of the sewing machine is inserted, A biasing member fixed to the lower side of the needle plate, A movable blade is provided so as to be rotatable in the horizontal direction relative to the fixed blade and the biasing member, When the movable blade is in a blade standby position, separated horizontally from the fixed blade, a thread clamping portion is provided, positioned between the biasing member and the needle plate in the vertical direction, facing the biasing member, biased upward by the biasing member, and capable of clamping the end of the bobbin thread after it has been cut by the movable blade between itself and the biasing member. When the movable blade is in a release position different from the blade standby position, in the vertical direction, between the needle plate and the biasing member, a thread release portion is positioned opposite the biasing member and is unable to clamp the lower thread end between itself and the biasing member. The movable blade having, A blade moving unit having a motor, the power of which rotates the movable blade in the horizontal direction, The aforementioned blade standby position and, The aforementioned release position and, The cutting position where the movable blade intersects with the fixed blade to cut the upper thread and the lower thread, With respect to the cutting position, the movable end position is on the opposite side from the blade standby position. The blade moving part moves the movable blade between and A cutting mechanism characterized by comprising the following features.

2. The cutting mechanism according to claim 1, characterized in that the pivot point of the movable blade is provided on the side opposite to the motor side with respect to the needle hole, in the direction from the motor toward the needle hole on a plane parallel to the needle plate.

3. The cutting mechanism according to claim 1 or 2, characterized in that the biasing member is a leaf spring.

4. The cutting mechanism according to any one of claims 1 to 3, characterized in that the thread release portion is an upwardly recessed portion provided on the lower surface of the movable blade adjacent to the thread gripping portion.

5. A needle plate having a needle hole formed for inserting a sewing needle, A cutting mechanism according to any one of claims 1 to 4 and A sewing device characterized by being equipped with the following features.

6. The sewing apparatus according to claim 5, further comprising an upper thread holding mechanism that is driven by the power of the motor and releasably holds the upper thread end of the upper thread that has been passed through the sewing needle on the lower side of the needle plate.

7. The aforementioned upper thread holding mechanism is A first retaining member provided on the lower surface of the needle plate, A second retaining member is rotatably supported on the needle plate by a support portion and cooperates with the first retaining member to hold the end of the upper thread, A holding and moving unit which moves the second holding member in the horizontal direction using the power of the motor, In the horizontal direction, between the first retaining member and the second retaining member, there is a standby position where the needle hole is located, In the horizontal direction, the second retaining member is separated from the pinhole, and the second retaining member is in a holding position that overlaps with the first retaining member in the vertical direction. The holding moving part moves the second holding member and The sewing apparatus according to claim 6, characterized by having the following features.

8. The sewing apparatus according to claim 7, characterized in that the support portion is provided on the motor side with respect to the needle hole in a direction from the motor toward the needle hole on a plane parallel to the needle plate.

9. When the second holding member is in the standby position, the movable blade is in the blade standby position, The sewing apparatus according to claim 7, characterized in that when the second holding member is in the holding position, the movable blade and the biasing member grip the end of the lower thread.

10. The needle plate is further equipped with a fixed blade that is fixed to the lower side, The holding and moving part is capable of moving the second holding member to the standby position, the holding position, and the upper thread cutting position in which the upper thread end held by the first holding member and the second holding member is cut by the fixed scalpel. The sewing apparatus according to claim 7 or 9, characterized in that when the second holding member is in the upper thread cutting position, the movable blade is in the release position.

11. Controlling the motor, A thread cutting process in which the movable blade is moved from the blade standby position to the movable end position, then to the cutting position to cut the upper thread and the lower thread, The movable blade is moved from the cutting position to the blade standby position, and the end of the lower thread cut in the thread cutting process is clamped between the biasing member and the thread clamping part in a clamping process, The release process involves moving the movable blade from the blade standby position to the release position to release the end of the bobbin thread that was gripped in the gripping process. The sewing apparatus according to any one of claims 7 to 10, further comprising a control device for performing the action.

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