Sewing machine

Abstract

To provide a sewing device in which the degree of freedom in setting the length of a needle thread and a bobbin thread is improved more than before.SOLUTION: A control device of a sewing machine drives a needle bar mechanism and a feed dog, and executes sewing work for forming a seam on a workpiece with a thread (S7). The control device executes a yarn catching process of moving the movable blade from the standby position to a yarn catching position where the movable blade catches the yarn, and further moving the movable blade to a movable position on a side opposite to the standby position with respect to the yarn catching position. The control device executes length adjustment processing for positioning the lower end of the needle above the throat plate to make the workpiece movable in a state where the movable blade catches the thread by the thread catching processing (S11). After the length adjustment processing, the control device executes cut processing for moving the movable blade to a cut position where the movable blade crosses the fixed blade and cutting the thread (S14).SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a sewing device. [Background technology]

[0002] A conventional sewing device includes a thread length adjustment mechanism, a guide, and a cutting member. The cutting member cuts the upper and lower threads between the needle plate hole and the cutting member. The thread length adjustment mechanism includes an adjusting knife. The adjusting knife is disposed between the needle plate hole and the cutting member and captures and moves the upper and lower threads to adjust the length of the upper and lower threads from the needle plate hole to the cutting member. The guide is disposed between the needle plate hole and the adjusting knife and guides the upper and lower threads as the adjusting knife moves. The guide can change the length of a second thread feed path connecting the needle plate hole, the guide, and the adjusting knife, relative to a first thread feed path that directly connects the needle plate hole and the adjusting knife. Because the length of the first thread feed path is set longer than the second thread feed path, the sewing device can obtain the same remaining thread amount as that obtained by the first thread feed path with a smaller movement of the adjusting knife. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-115365 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional sewing devices, the length of the upper thread and the lower thread is limited by the amount of movement of the adjusting knife portion.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a sewing device that allows greater freedom in setting the lengths of the upper thread and bobbin thread than in the past. [Means for solving the problem]

[0006] The sewing device of claim 1 of the present invention comprises a needle bar mechanism having a needle bar at the lower end of which a sewing needle can be attached and which swings the needle bar up and down, a needle plate located below the needle bar, a feed dog which feeds a sewing material in at least one direction relative to the needle bar mechanism, a cutting mechanism capable of cutting threads, the cutting mechanism having a fixed blade fixed to the underside of the needle plate, a movable blade which is provided so as to be rotatable in a horizontal direction relative to the fixed blade, and a blade moving part which rotates the movable blade in the horizontal direction, and a control device which controls the needle bar mechanism, the feed dog, and the cutting mechanism, and the control device controls the needle bar mechanism. The sewing device performs a sewing process in which the movable blade and the feed dog are driven to form a stitch on the sewn material with the thread; a thread capturing process in which the movable blade is moved from a standby position to a thread capturing position where the movable blade captures the thread, and then to a movable position opposite the standby position with respect to the thread capturing position; a length adjustment process in which, with the movable blade capturing the thread as a result of the thread capturing process, the lower end of the sewing needle is positioned above the needle plate to allow the sewn material to move; and a cutting process in which, after the length adjustment process, the movable blade is moved to a cutting position where it intersects with the fixed blade and cuts the thread. The sewing device can adjust the length of the thread from the last stitch in the sewing sequence by pulling out the sewn material by a desired amount in the length adjustment process. The length adjustment process of the sewing device contributes to improving the degree of freedom in the length of the thread extending from the last stitch.

[0007] The sewing device of claim 2 of the present invention further comprises an input unit, and when an adjustment instruction to execute the length adjustment process is acquired by the input unit, the sewing device executes the thread catching process and the length adjustment process. The sewing device contributes to facilitating input of instructions for when to execute the thread catching process and the length adjustment process.

[0008] The sewing device of claim 3 of the present invention further includes a tension applying mechanism that applies tension to the thread, and the control device drives the tension applying mechanism during the length adjustment process to perform a reduction process that reduces the tension applied to the thread to a level lower than the tension during the sewing process. The sewing device contributes to making it easier to move the sewn material between the length adjustment process and the cutting process compared to when the reduction process is not performed.

[0009] The sewing device of claim 4 of the present invention further includes a thread reeling mechanism that reels out the thread, and the control device further executes a reeling process that drives the thread reeling mechanism to reel out a predetermined amount of the thread during the length adjustment process. The sewing device contributes to making it easier to move the sewn material between the length adjustment process and the cutting process compared to when the reeling process is not executed.

[0010] In the sewing device of claim 5 of the present invention, the cutting position is the same as the standby position. Compared to a sewing device in which the cutting position is not the same as the standby position, the sewing device can be made more compact and drive control can be simplified.

[0011] The control device of the sewing device of claim 6 of the present invention stops the movable blade at a stop position between the movable position and the cutting position in the length adjustment process, and executes the cutting process when a cutting instruction to execute the cutting process is received. Compared to when the sewing device does not stop at the stop position, the length adjustment process makes it easier for the sewing device to secure the time required to transport the sewn material a predetermined distance.

[0012] In the sewing device of claim 7 of the present invention, the thread includes an upper thread and a lower thread, the movable blade has a lower thread scooping portion capable of cutting the lower thread in cooperation with the fixed blade, and a blade portion capable of cutting the upper thread in cooperation with the fixed blade, and the stop position is a position just before cutting the lower thread and the upper thread, where the horizontal distance from the cutting edge of the fixed blade to the lower thread scooping portion or the blade portion of the movable blade is within 5 mm. The sewing device can properly cut the upper thread and the lower thread in the cutting process compared to when the horizontal distance from the cutting edge of the fixed blade to the lower thread scooping portion or the blade portion of the movable blade is greater than 5 mm.

[0013] In the sewing device of claim 8 of the present invention, the thread includes an upper thread and a bobbin thread. The sewing device can adjust the length of the upper thread and the bobbin thread from the last stitch in the sewing sequence by pulling out the sewn material by a desired amount using a length adjustment process. The length adjustment process of the sewing device contributes to improving the degree of freedom in the length of the upper thread and the bobbin thread extending from the last stitch.

[0014] In the sewing device of claim 9 of the present invention, the feed dog has a needle hole formed therein through which the sewing needle can be inserted. The length adjustment process of the sewing device contributes to improving the degree of freedom in the length of the thread extending from the last stitch in a sewing device in which a needle hole is formed in the feed dog. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an overall perspective view of a sewing device 1. [Figure 2] FIG. 2 is a perspective view of the shuttle mechanism 50 and the cutting mechanism 60. [Figure 3] 2 is a perspective view of a part of the shuttle mechanism 50 and the cutting mechanism 60. FIG. [Figure 4] 10 is a perspective view of the shuttle mechanism 50 and the cutting mechanism 60 when the movable blade 62 is at a stop position P4 in a state where the movable blade 62 has caught the upper thread U and the lower thread L. FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. [Figure 6] (A) is a plan view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the standby position P1, (B) is a plan view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the movable position P3, (C) is a plan view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the stop position P4, and (D) is a plan view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the cutting position P5. [Figure 7] (A) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the standby position P1, (B) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the movable position P3, (C) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the stop position P4, and (D) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the cutting position P5. [Figure 8](A) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the standby position P1, (B) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the movable position P3, (C) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the stop position P4, and (D) is an oblique view of the shuttle mechanism 50 and cutting mechanism 60 when the movable blade 62 is in the cutting position P5. [Figure 9] 2 is a block diagram showing the electrical configuration of the sewing device 1. FIG. [Figure 10] 3 is a flowchart of the main process of the sewing device 1. [Figure 11] FIG. 10 is an explanatory diagram showing the relationship between the position of the left end of the cam surface 681 of the thread cutting cam 68 that faces the contact portion 672, the operation of the thread cutting solenoid 59, the position of the movable blade 62, and the main shaft angle, which is the rotation angle of the main shaft motor 21, at the end of sewing. DETAILED DESCRIPTION OF THE INVENTION

[0016] The physical configuration of the sewing device 1 of the present invention will be described below. In the following description, arrows in the drawings will be used to indicate left and right, front and back, and up and down. As shown in Figure 1, the sewing device 1 is an integrated feed sewing machine, and includes a bed 2, a pillar 3, an arm 4, and a head 20.

[0017] 1 to 3, bed portion 2 has needle plate 14 on its upper surface and accommodates lower shaft 32, shuttle mechanism 50, feed mechanism (not shown), cutting mechanism 60, etc. Lower shaft 32 extends in the left-right direction and rotates in synchronization with main shaft 31.

[0018] As shown in FIG. 2, the shuttle mechanism 50 includes a shuttle base 54, a shuttle shaft (not shown), an outer shuttle 51, and an inner shuttle 52. The shuttle base 54 is disposed below the needle plate 14. A shuttle shaft gear and a shuttle shaft (not shown) are provided inside the shuttle base 54. The shuttle base 54 rotatably supports the shuttle shaft. The shuttle shaft extends vertically and rotates in response to the rotation of the lower shaft 32. The outer shuttle 51 is fixed to the upper end of the shuttle shaft and rotates together with the shuttle shaft. The outer shuttle 51 has a point 53 that captures the upper thread loop. A recess 55 is formed around the point 53 of the outer shuttle 51, recessed downward. The outer shuttle 51 rotatably supports the inner shuttle 52. The shuttle mechanism 50 is driven by the rotation of the lower shaft 32 and entangles the upper thread U and the bobbin thread L (shown in FIG. 4) below the needle plate 14.

[0019] The feed mechanism includes a feed dog 17, and drives the feed dog 17 in synchronization with the rotation of the lower shaft 32 to move the sewn material in a feed direction by a predetermined feed amount. The feed direction is either backward or forward. The sewing device 1 of this embodiment is a so-called integrated feed sewing machine, and the feed dog 17 has a needle eye 23 formed therein through which the sewing needle 7 can be inserted. Therefore, as the feed dog 17 is driven, the feed dog 17 protrudes upward from a rectangular hole 24 formed in the throat plate 14, and the needle eye 23 also moves in the front-to-back and up-to-down directions. The cutting mechanism 60 is driven by the power of the thread cutting solenoid 59 and the main shaft motor 21 shown in FIG. 9, and cuts the upper thread U and the bobbin thread L at the end of the sewing operation. Details of the cutting mechanism 60 will be described later.

[0020] As shown in Figure 1, pillar 3 extends upward from the right end of bed 2 and houses main shaft motor 21, presser motor 22 (see Figure 9), etc. Main shaft motor 21 rotates main shaft 31. Presser motor 22 is a pulse motor located to the left and rear of main shaft motor 21, and adjusts the downward presser pressure applied to the sewing material by presser foot 11 attached to the lower end of presser bar 10.

[0021] The arm 4 extends leftward from the upper end of the pillar 3. The arm 4 has a display 15, a touch screen 16, a switch 19, and a tensioning mechanism 13 on its front surface. The display 15 is a liquid crystal display that displays images. The touch screen 16 is provided on the front surface of the display 15 and allows various instructions to be input to the control unit 30. The switch 19 is provided to the right of the display 15 and inputs various instructions to the control unit 30.

[0022] As shown in FIG. 5, the tension applying mechanism 13 includes a thread tension table 28, a thread tension motor 25, and thread tension discs 26 and 27. The thread tension table 28 is an annular member that is fitted onto the output shaft 29 of the thread tension motor 25. The thread tension motor 25 is fixed to the inside of the arm portion 4. The output shaft 29 of the thread tension motor 25 protrudes forward from the front surface of the arm portion 4. The thread tension discs 26 and 27 are fixed forward of the output shaft 29. The thread tension disc 26 is positioned in front of the thread tension disc 27. The upper thread U is sandwiched between the thread tension discs 26 and 27 and wound around it about one or two times. The thread tension discs 26 and 27 are rotated by the drive of the thread tension motor 25. The tension applying mechanism 13 applies a predetermined tension to the upper thread U by the drive of the thread tension motor 25.

[0023] As shown in FIG. 1, the arm portion 4 houses the thread tension motor 25, the main shaft 31, etc. The thread tension motor 25 is a pulse motor, and the sewing device 1 can adjust the tension applied to the upper thread U by adjusting the drive voltage supplied to the thread tension motor 25. The main shaft 31 extends in the left-right direction. The right end of the main shaft 31 is connected to the main shaft motor 21, and the left end is connected to the needle bar mechanism 33 shown in FIG. 9.

[0024] The head 20 is mounted on the left end of the arm 4, and has a thread take-up lever 12 mounted on its front surface. The thread take-up lever 12 pulls up the upper thread U and forms a knot with the bobbin thread L. The head 20 has a thread reeling mechanism 40 mounted on its left surface. The thread reeling mechanism 40 is configured to reel out a predetermined amount of the upper thread U. The thread reeling mechanism 40 includes a thread reeling air cylinder 43 and a reeling lever 42. The output shaft 41 of the thread reeling air cylinder 43 extends in the front-rear direction and is extendable between a normal position and a protruding position in which the front end of the output shaft 41 protrudes further forward than when the front end of the output shaft 41 is in the normal position. One end 44 of the reeling lever 42 is connected to the front end of the output shaft 41. The other end of the reeling lever 42 has a bent portion 45 bent in a loop shape. When the output shaft 41 is in the normal position, the bent portion 45 is located to the right of the output shaft 41 in a plan view, and forms a thread path between the output shaft 41 and the sewing needle 7. When the output shaft 41 is in the extended position, the bending portion 45 is located further forward than when the output shaft 41 is in the normal position, making the thread path longer. The thread reeling air cylinder 43 reels out a predetermined amount of the upper thread U passed through the bending portion 45 by extending the output shaft 41 from the normal position to the extended position and then returning it to the normal position.

[0025] The sewing device 1 is provided with a needle bar 6, an outer presser bar 10, and an intermediate presser bar 8, which are mounted below the head 5 and are swung up and down by the drive of a main shaft motor 21. The needle bar 6 extends up and down in front of the intermediate presser bar 8, and a sewing needle 7 can be attached and detached to its lower end. A thread spool (not shown) supplies an upper thread U to the eye of the sewing needle 7. An intermediate presser foot 9 can be attached to the lower end of the intermediate presser bar 8, and the intermediate presser foot 9 presses down from above a sewing item placed on a needle plate 14. An outer presser foot 11 can be attached to the lower end of the outer presser bar 10, and the outer presser foot 11 presses down from above a sewing item placed on the needle plate 14. The outer presser bar 10 and the intermediate presser bar 8 are moved up and down by the power of the presser motor 22 between an elevated position where the intermediate presser foot 9 and the outer presser foot 11 are above the needle plate 14 and a lowered position where the intermediate presser foot 9 and the outer presser foot 11 are lower than when they are in the elevated position and closer to the needle plate 14.

[0026] The cutting mechanism 60 will be described with reference to Figs. 2 to 8(D). The cutting mechanism 60 includes a fixed blade 61, a movable blade 62, a support shaft 63, and a moving section 69. The fixed blade 61 is disposed below the needle plate 14 and behind the outer shuttle 51. The fixed blade 61 is generally L-shaped in plan view, and is fixed to the shuttle base 54 with a screw 611. The fixed blade 61 includes a cutting edge 612. The cutting edge 612 is provided at the left front end of the fixed blade 61 and extends in the front-to-rear direction.

[0027] The movable blade 62 is supported by the shuttle base 54 to the right of the outer shuttle 51 and is rotatable about an axis J extending in the vertical direction. The movable blade 62 is curved in an arc shape that is convex rearward in a plan view and convex upward in a front view, extends leftward from the axis J, and is rotatable horizontally relative to the fixed blade 61 about the axis J.

[0028] As shown in FIG. 4, the movable blade 62 has a tip portion 621, a blade portion 622, a bobbin thread scooping portion 623, a thread guide portion 624, and a thread catcher portion 625. The tip portion 621 is shaped to be pointed forward. The blade portion 622 is a recess formed on the left surface of the movable blade 62 that is recessed upward and forward. The blade portion 622 is a portion that hooks the side of the upper thread loop that extends from the sewing needle 7. The blade portion 622 is capable of cutting the upper thread U in cooperation with the fixed blade 61. The bobbin thread scooping portion 623 is a recess formed on the left surface of the movable blade 62, behind the blade portion 622, that is recessed upward and forward. The bobbin thread scooping portion 623 is a portion that hooks the bobbin thread L extending from the bobbin and is capable of cutting the bobbin thread L in cooperation with the fixed blade 61. The thread guide 624 is a portion that curves in an arc shape between the tip 621 and the thread catcher 625. The thread guide 624 guides the side of the upper thread loop that extends from the sewn material to the thread catcher 625. The thread catcher 625 is a portion that catches the upper thread loop.

[0029] 3, the support shaft 63 extends in the vertical direction below the needle plate 14. The support shaft 63 is supported by the shuttle base 54 so as to be rotatable about an axis J. An upper end 631 of the support shaft 63 is disposed above the shuttle base 54, and the right end of the movable blade 62 is fixed thereto by a screw 629.

[0030] The moving part 69 has a thread cutting solenoid 59, a link member 64, and a thread cutting cam 68, and rotates the movable blade 62 horizontally around the axis J by the power of the thread cutting solenoid 59 and the main shaft motor 21. The thread cutting solenoid 59 has an output shaft 591 that extends forward, and is switchable between an OFF state and an ON state in which the output shaft 591 protrudes further forward than in the OFF state.

[0031] The link member 64 is connected to the output shaft 591 of the thread cutting solenoid 59 and rotates the support shaft 63 around axis J in response to the drive of the thread cutting solenoid 59 and the rotational position of the thread cutting cam 68. The link member 64 is an E-shaped member when viewed from the right side and includes an output shaft connecting portion 65, a support shaft connecting portion 66, and an abutment portion 67. The output shaft connecting portion 65 includes a connecting portion 651, a shaft 652, and a support portion 653. The connecting portion 651 is connected to the front end of the output shaft 591 of the thread cutting solenoid 59. The shaft 652 extends in the vertical direction and supports the connecting portion 651 to be rotatable around axis K, which also extends in the vertical direction. The support portion 653 supports the upper and lower ends of the shaft 652. The support shaft connecting portion 66 extends rearward from the lower right end of the support portion 653. The support portion 653 includes a support portion 661 and a fixing member 662. The support portion 661 is formed in a ring shape in a plan view, and the support shaft 63 is inserted therethrough. The fixing member 662 fixes the support shaft 63 inserted through the support portion 661. The abutment portion 67 includes an arm portion 671 and an abutment portion 672. The arm portion 671 extends downward and forward from the front end of the support shaft connecting portion 66. The abutment portion 672 protrudes downward and rearward in a hemispherical shape from the front end portion of the back surface of the arm portion 671.

[0032] The thread cutting cam 68 is fitted onto the lower shaft 32 and rotates together with the lower shaft 32. The left surface of the thread cutting cam 68 is a curved cam surface 681. The thread cutting cam 68 determines the left-right position of the abutment portion 672 when the thread cutting solenoid 59 is in the ON state. Specifically, when the thread cutting solenoid 59 is in the OFF state, the abutment portion 672 is located at the left end of its left-right movement range and does not generally come into contact with the cam surface 681. When the thread cutting solenoid 59 is switched from the OFF state to the ON state, the abutment portion 672 is pressed against the cam surface 681 and moves along the cam surface 681 within the left-right movement range of the abutment portion 672. As the abutment portion 672 moves, the movable blade 62 rotates horizontally around the axis J. When the thread cutting solenoid 59 is switched from the ON state to the OFF state, the contact portion 672 is pushed leftward by the thread cutting cam 68 and moved to the left end of the left-right movement range of the contact portion 672, and then does not move from that position. As the contact portion 672 moves, the movable blade 62 moves clockwise in a plan view around the axis J, and then does not move from the standby position P1.

[0033] The moving unit 69 rotates the link member 64 around the axis J using the power of the thread cutting solenoid 59 and the main shaft motor 21, thereby moving the movable blade 62 around the support shaft 63, more specifically the axis J, to each of the standby position P1, the thread capturing position P2, the movable position P3, the stop position P4, and the cutting position P5 shown in Figures 6(A) to 8(D).

[0034] 6(A), 7(A), and 8(A), the standby position P1 is a position where the movable blade 62 is horizontally spaced apart from the needle hole 23 and is close to the fixed blade 61. When the movable blade 62 is in the standby position P1, the movable blade 62 is horizontally spaced apart from the rectangular hole 24 of the needle plate 14. The standby position P1 is the rear end of the movable range of the movable blade 62.

[0035] 6(B), the thread catching position P2 is a position where the movable blade 62 catches the lower thread L near the needle eye 23. Compared to when the movable blade 62 is in the standby position P1, the thread catching position P2 is a position where the movable blade 62 rotates counterclockwise in a plan view and is positioned above the outer hook 51.

[0036] 6(B), 7(B), and 8(B), the movable position P3 is a position where the movable blade 62 is disposed forward relative to the outer shuttle 51. In other words, the movable blade 62 at the movable position P3 is located on the opposite side of the outer shuttle 51 from the side where the movable blade 62 is located at the standby position P1. The movable position P3 is the front end of the movable range of the movable blade 62, and is the position farthest from the standby position P1.

[0037] As shown in FIGS. 6(C), 7(C), and 8(C), stop position P4 is a position just before the lower thread L and the upper thread U are cut, and is between movable position P3 and cutting position P5. Stop position P4 is preferably a position where the horizontal distance from the cutting edge 612 of the fixed blade 61 to the lower thread scooping portion 623 or the blade portion 622 of the movable blade 62 is within 5 mm. As shown in FIG. 4, stop position P4 in this embodiment is a position where the horizontal distance D from the cutting edge 612 of the fixed blade 61 to the lower thread scooping portion 623 of the movable blade 62 is within 5 mm. Stop position P4 is a position just before cutting position P5 on the movement path of the movable blade 62 when moving from movable position P3 toward cutting position P5. On the movement path of the movable blade 62, stop position P4 is between movable position P3 and cutting position P5. When the movable blade 62 is at the stop position P4, the tip 53 of the outer hook 51 is located to the left of the movable blade 62, and the lower thread scooping portion 623 and the blade portion 622 of the movable blade 62 face the recessed portion 55 of the outer hook 51. The main process in which the sewing device 1 moves the movable blade 62 to each position will be described later.

[0038] 6(D), 7(D), and 8(D), cutting position P5 is a position where the movable blade 62 cooperates with the fixed blade 61 to cut the upper thread U and the lower thread L, and is a position where the movable blade 62 is disposed rearward relative to the outer hook 51. The blade portion 622 in this embodiment is hook-shaped in a side view, and cuts the upper thread U and the lower thread L as it moves rearward after moving to movable position P3. Therefore, the tip of the blade portion 622 in this embodiment is the front end portion of the blade portion 622. The cutting position P5 in this embodiment is the same position as the standby position P1.

[0039] The electrical configuration of the sewing device 1 will be described with reference to Figure 9. The control unit 30 of the sewing device 1 has a CPU 91, a ROM 92, a RAM 93, a storage device 94, an input / output interface (I / O) 95, drive circuits 81 to 86, etc. The CPU 91 controls the overall operation of the sewing device 1. The ROM 92 stores in advance programs and the like for executing various processes. The RAM 93 temporarily stores various information generated during the execution of various processes. The storage device 94 is non-volatile and stores various setting values.

[0040] Each of the drive circuits 81 to 86 is connected to the I / O 95. The drive circuit 81 is connected to the main shaft motor 21 and drives the main shaft motor 21 in response to a control command from the CPU 91. The drive circuit 82 is connected to the presser foot motor 22 and drives the presser foot motor 22 in response to a control command from the CPU 91. The drive circuit 83 is connected to the thread tension motor 25 and drives the thread tension motor 25 in response to a control command from the CPU 91. The drive circuit 84 is connected to the thread cutting solenoid 59 and drives the thread cutting solenoid 59 in response to a control command from the CPU 91. The drive circuit 85 is connected to the thread reeling air cylinder 43 and drives the thread tension motor 25 in response to a control command from the CPU 91. The drive circuit 86 is connected to the display unit 15 and drives the display unit 15 in response to a control command from the CPU 91.

[0041] Encoders 56, 57, touch screen 16, switch 19, and pedal 18 are connected to I / O 95. Encoder 56 detects the rotational position and rotational speed of main shaft 31 connected to the output shaft of main shaft motor 21, and inputs the detection results to I / O 95. In this embodiment, the angle of main shaft 31 is set to 0 degrees when needle bar 6 is at the top dead center. Encoder 57 detects the rotational position and rotational speed of the output shaft of presser foot motor 22, and inputs the detection results to I / O 95. Touch screen 16 and switch 19 detect various instructions, and input the detection results to I / O 95. Pedal 18 detects the operation direction and operation amount of pedal 18, and inputs the detection results to I / O 95.

[0042] The main processing executed by the sewing device 1 will be described with reference to Figures 9 to 14. In the main processing, a process for forming stitches on a sewn material is executed. When the power of the sewing device 1 is turned on, the CPU 91 starts the main processing. When the power of the sewing device 1 is turned on, the CPU 91 reads out a program for executing the main processing stored in the program storage area of ​​the ROM 92 into the RAM 93. The CPU 91 executes the following steps in accordance with instructions contained in the program read out into the RAM 93. Hereinafter, step is abbreviated as S. Various parameters required to execute the main processing are stored in the storage device 94. Various data obtained in the course of the main processing is stored in the RAM 93 as appropriate.

[0043] 10, the CPU 91 determines whether an origin detection command has been detected (S1). The operator operates the touch screen 16 to input the origin detection command. If the origin detection command has not been detected (S1: NO), the CPU 91 returns the process to S1. If the origin detection command has been detected (S1: YES), the CPU 91 executes origin detection (S2), drives the presser motor 22, and raises the outer presser bar 10 and the inner presser bar 8 to their raised positions (S3).

[0044] The operator places the sewing material between the needle plate 14 and the presser feet 9, 11 and operates the pedal 18 to input a command to lower the presser foot 9. The CPU 91 determines whether a command to lower the presser feet 9, 11 has been detected (S4). If a command to lower the presser feet 9, 11 has not been detected (S4: NO), the CPU 91 returns the process to S4. If a command to lower the presser feet 9, 11 has been detected (S4: YES), the CPU 91 drives the presser motor 22 to lower the outer presser bar 10 and the inner presser bar 8 to their lowered positions (S5). As shown in Figures 6(A), 7(A), and 8(A), the movable blade 62 of the cutting mechanism 60 is located at the standby position P1.

[0045] The CPU 91 determines whether a sewing instruction has been detected (S6). The operator inputs the sewing instruction by operating the pedal 18. If a sewing instruction has not been detected (S6: NO), the CPU 91 returns the process to S6.

[0046] When a sewing instruction is detected (S6: YES), the CPU 91 drives the main shaft motor 21 to start sewing (S7). The CPU 91 determines whether an adjustment instruction is detected based on the detection result of the pedal 18 (S8). When an adjustment instruction is not detected (S8: NO), the CPU 91 returns the process to S8. When the operator operates the pedal 18 and an adjustment instruction to execute the length adjustment process is acquired, the sewing device 1 of this embodiment executes the thread capturing process of S9 and the length adjustment process of S11.

[0047] When an adjustment instruction is detected (S8: YES), the CPU 91 performs a thread catching process (S9). The thread catching process moves the movable blade 62 from the standby position P1 to a thread catching position P2 where the movable blade 62 catches the lower thread L, and then moves the movable blade 62 to a movable position P3 on the opposite side of the standby position P1 with respect to the thread catching position P2. Specifically, as shown in FIG. 11, the CPU 91 switches the thread cutting solenoid 59 from an OFF state to an ON state during a period T1 from when the adjustment instruction is detected until the main shaft angle reaches a first predetermined angle. The output shaft 591 of the thread cutting solenoid 59 protrudes forward and rotates the link member 64 counterclockwise in a plan view around the axis J. The contact portion 672 contacts a cam surface 681 of the thread cutting cam 68, restricting movement of the link member 64 around the axis J. The contact portion 672 moves rightward along the cam surface 681. As the abutment portion 672 moves, the movable blade 62 of the cutting mechanism 60 moves from the standby position P1 shown in Fig. 6(A) to the thread catching position P2 shown in Fig. 6(B). The lower thread catcher 623 of the movable blade 62 catches the lower thread L near the needle eye 23 at the thread catching position P2. The movable blade 62 further moves from the thread catching position P2 to a movable position P3 shown in Fig. 6(B). When the main shaft angle is at the first predetermined angle, the abutment portion 672 is located at the right end of the movable range of the abutment portion 672, and the movable blade 62 is positioned at the movable position P3.

[0048] The CPU 91 drives the presser motor 22 to raise the outer presser bar 10 and the inner presser bar 8 to their raised positions. The CPU 91 switches the energization pattern for the thread tension motor 25 and drives it to reduce the tension of the upper thread U (S10). Alternatively, the CPU 91 drives the thread tension motor 25 to rotate a predetermined amount in the direction in which the upper thread U is fed. The sewing device 1 of this embodiment drives the tension applying mechanism 13 to reduce the tension applied to the upper thread U during the length adjustment process to be lower than the tension during the sewing process.

[0049] The CPU 91 starts the length adjustment process (S11). The length adjustment process is a process for positioning the lower end of the sewing needle 7 above the needle plate 14, with the movable blade 62 capturing the upper thread U and the bobbin thread L as a result of the thread capturing process of S9, thereby enabling the movement of the sewn product. Specifically, in the length adjustment process, the CPU 91 further moves the movable blade 62 of the cutting mechanism 60 from the thread capturing position P2 to the movable position P3, and then stops the movable blade 62 at a stop position P4 between the movable position P3 and the cutting position P5. During the process of moving from the movable position P3 to the stop position P4, the thread capturing portion 625 of the movable blade 62 captures the upper thread U near the needle eye 23 at the thread capturing position P2. More specifically, as shown in FIG. 11 , the CPU 91 maintains the thread cutting solenoid 59 in the ON state during a period T2 during which the main shaft angle is changed from the first predetermined angle to the second predetermined angle. In this embodiment, the CPU 91 drives the thread cutting solenoid 59 with less power during period T2 than during period T1 to suppress heat generation in the thread cutting solenoid 59. During period T2, the contact portion 672 moves leftward along the cam surface 681 of the thread cutting cam 68. The first and second predetermined angles may be set as appropriate; for example, the first predetermined angle is 290 degrees and the second predetermined angle is 10 degrees. When the main shaft angle is at the second predetermined angle, the CPU 91 turns off the thread cutting solenoid 59 and stops the main shaft motor 21. When the main shaft angle is at the second predetermined angle, the lower end of the sewing needle 7 is positioned above the needle plate 14.

[0050] The CPU 91 drives the thread reeling mechanism 40 to reel out a predetermined length of the upper thread U (S12). Based on a control command from the CPU 91, the thread reeling air cylinder 43 protrudes the output shaft 41 forward by a predetermined amount. As the output shaft 41 protrudes, the reeling lever 42 also moves forward by a predetermined amount and then returns to its normal position. Prior to the processing of S12, the processing of S10 reduced the tension applied to the upper thread U compared to during sewing, so that the upper thread U is smoothly reeled out by the driving of the thread reeling mechanism 40. Furthermore, the movable blade 62 is positioned at stop position P4, and the lower thread scooping portion 623 and the blade portion 622 of the movable blade 62 face the recessed portion 55 of the outer hook 51. Therefore, in the sewing device 1, the upper thread U captured by the blade portion 622 and the lower thread L captured by the lower thread scooping portion 623 can be more easily pulled out above the needle plate 14 through the space formed by the recessed portion 55, compared to when the blade portion 622 that captures the upper thread U and the lower thread scooping portion 623 that captures the lower thread L do not face the recessed portion 55 of the outer hook 51.

[0051] The CPU 91 determines whether a cutting instruction to execute the cutting process has been detected based on the detection result of the pedal 18 (S13). The sewing device 1 of this embodiment executes the cutting process when a cutting instruction is acquired after stopping the movable blade 62 at the stop position P4. After moving the sewn product a desired distance, the operator operates the pedal 18 to input the cutting instruction. In S10, the outer presser bar 10 and the inner presser bar 8 are raised to their raised positions, in S11 the sewing needle 7 is positioned above the needle plate 14, and further in S12 the upper thread U is fed out by a predetermined amount, making it easy for the operator to move the sewn product horizontally.

[0052] If a cutting instruction is not detected (S13: NO), the CPU 91 returns the process to S13. If a cutting instruction is detected (S13: YES), the CPU 91 performs the cutting process (S14). In this embodiment, the cutting process is performed when the outer presser bar 10 and the inner presser bar 8 are in their raised positions and the tension applied to the upper thread U is reduced compared to during sewing. Specifically, during the period T3 in which the main shaft angle is from the second predetermined angle to the third predetermined angle, the CPU 91 drives the main shaft motor 21 to move the contact portion 672, which is in contact with the thread cutting cam 68, to the left and rotate the link member 64 clockwise in a plan view. The third predetermined angle may be set as appropriate; for example, the third predetermined angle is 65 degrees. As shown in FIGS. 6(D), 7(D), and 8(D), the movable blade 62 moves to the cutting position P5 and cuts the upper thread U and the bobbin thread L. The CPU 91 stops the main shaft motor 21 when the main shaft angle reaches the third predetermined angle (S15). In S15, the lower end of the sewing needle 7 is positioned above the sewing material. The CPU 91 then ends the main process.

[0053] In the above embodiment, the sewing device 1, needle bar 6, sewing needle 7, tensioning mechanism 13, needle plate 14, feed dog 17, needle bar mechanism 33, cutting mechanism 60, fixed blade 61, movable blade 62, CPU 91, bobbin thread scoop 623, and blade 622 are examples of the sewing device, needle bar, sewing needle, tensioning mechanism, needle plate, feed dog, needle bar mechanism, cutting mechanism, fixed blade, movable blade, control device, bobbin thread scoop, and blade, respectively, of the present invention. The standby position P1, thread capturing position P2, movable position P3, stop position P4, and cutting position P5 are examples of the standby position, thread capturing position, movable position, stop position, and cutting position, respectively, of the present invention.

[0054] The sewing device 1 of the above embodiment is equipped with a needle bar mechanism 33 which has a needle bar 6 at the lower end to which a sewing needle 7 can be attached and which swings the needle bar 6 up and down, a needle plate 14 located below the needle bar 6, a feed dog 17 which feeds the sewn material in at least one direction relative to the needle bar mechanism 33, a cutting mechanism 60 which can cut the thread and which has a fixed blade 61 fixed to the underside of the needle plate 14, a movable blade 62 which is rotatable horizontally relative to the fixed blade 61, and a blade moving part which rotates the movable blade 62 horizontally, and a CPU 91 which controls the needle bar mechanism 33, the feed dog 17, and the cutting mechanism 60, and the CPU 91 drives the needle bar mechanism 33 and the feed dog 17 to perform a sewing process which forms a stitch on the sewn material with the thread (S7). The CPU 91 executes a thread capturing process in which the movable blade 62 moves from the standby position P1 to a thread capturing position P2 where the movable blade 62 captures the bobbin thread L, and then moves the movable blade 62 to a movable position P3 on the opposite side of the standby position P1 from the thread capturing position P2 (S9). With the movable blade 62 capturing the upper thread U and the bobbin thread L through the thread capturing process, the CPU 91 executes a length adjustment process in which the lower end of the sewing needle 7 is positioned above the needle plate 14 to enable movement of the sewn material (S11). After the length adjustment process, the CPU 91 executes a cutting process in which the movable blade 62 moves to a cutting position P5 where the movable blade 62 intersects with the fixed blade 61 and cuts the upper thread U and the bobbin thread L (S14). The sewing device 1 pulls out the sewn material by a desired amount through the length adjustment process, thereby adjusting the lengths of the upper thread U and the bobbin thread L from the last stitch in the sewing sequence. The length adjustment process of the sewing device 1 contributes to improving the degree of freedom in the lengths of the upper thread U and the bobbin thread L extending from the last stitch.

[0055] The sewing device 1 further includes a pedal 18 as an input unit, and when an adjustment instruction to execute the length adjustment process is acquired by the pedal 18 (S8: YES), the sewing device 1 executes the thread catching process and the length adjustment process (S11). The sewing device 1 contributes to facilitating input of instructions for when to execute the thread catching process and the length adjustment process.

[0056] The sewing device 1 further includes a tension applying mechanism 13 that applies tension to the upper thread U, and the CPU 91 executes a reduction process (S10) by driving the tension applying mechanism 13 to reduce the tension applied to the upper thread U during the length adjustment process to a level lower than the tension during the sewing process. The sewing device 1 contributes to making it easier to move the sewn material between the length adjustment process and the cutting process compared to when the reduction process is not executed.

[0057] The sewing device 1 further includes a thread reeling mechanism 40 that reels out the upper thread U, and the CPU 91 drives the thread reeling mechanism 40 during the length adjustment process to further execute a reeling process (S12) that reels out a predetermined amount of the upper thread U. The sewing device 1 contributes to making it easier to move the sewn material between the length adjustment process and the cutting process compared to when the reeling process is not executed.

[0058] In the sewing device 1, the cutting position P5 is the same as the standby position P1. This contributes to making the sewing device 1 more compact and simplifying drive control compared to a case in which the cutting position P5 is not the same as the standby position P1.

[0059] In the length adjustment process, the CPU 91 of the sewing device 1 stops the movable blade 62 at a stop position P4 between the movable position P3 and the cutting position P5, and executes the cutting process when a cutting instruction to execute the cutting process is acquired. Compared to when the sewing device 1 does not stop at the stop position P4, the length adjustment process contributes to making it easier to secure the time required to transport the sewn material a predetermined distance.

[0060] In the sewing device 1, the threads include an upper thread U and a lower thread L, the movable blade 62 has a lower thread scooping portion 623 that can cut the lower thread L in cooperation with the fixed blade 61, and a blade portion 622 that can cut the upper thread U in cooperation with the fixed blade 61, and the stop position P4 is a position just before the lower thread L and the upper thread U are cut, and is a position where the horizontal distance from the cutting edge 612 of the fixed blade 61 to the lower thread scooping portion 623 or the blade portion 622 of the movable blade 62 is within 5 mm. Compared to when the horizontal distance from the cutting edge 612 of the fixed blade 61 to the lower thread scooping portion 623 or the blade portion 622 of the movable blade 62 is greater than 5 mm, the sewing device 1 contributes to appropriately cutting the upper thread U and the lower thread L in the cutting process without the upper thread U and the lower thread L coming off the movable blade 62.

[0061] In the sewing device 1, the threads include an upper thread U and a lower thread L. The sewing device 1 can adjust the lengths of the upper thread U and lower thread L from the last stitch in the sewing sequence by pulling out the sewn material by a desired amount through the length adjustment process. The length adjustment process of the sewing device 1 contributes to improving the degree of freedom in the lengths of the upper thread U and lower thread L extending from the last stitch.

[0062] In the sewing device 1, a needle eye 23 through which the sewing needle 7 can be inserted is formed in the feed dog 17. The length adjustment process of the sewing device 1 contributes to improving the degree of freedom in the length of the thread extending from the last stitch in the sewing device 1 in which the needle eye 23 is formed in the feed dog 17.

[0063] The sewing device of the present invention can be modified in various ways beyond the above-described embodiment. The configuration of the sewing device 1 may be changed as needed. For example, the sewing device 1 may be a sewing device other than a combined feed sewing machine, such as a top-and-bottom feed sewing machine. The feed mechanism of the sewing device 1 is not limited to a combined feed mechanism, but may be a needle feed mechanism, a bottom feed mechanism, or a top-and-bottom feed mechanism. In the case of a bottom feed mechanism or a top-and-bottom feed mechanism, the needle eye 23 is formed in the needle plate 14 rather than in the feed dog 17, and the needle eye does not move during sewing. The sewing device 1 may omit at least one of the tensioning mechanism 13 and the thread reeling mechanism 40. The configuration, arrangement, etc. of the thread reeling mechanism may be changed as needed. The thread reeling mechanism may include a motor that rotates an output shaft, and the upper thread U may be reeled out by rotating the output shaft in the process of S12. The sewing device 1 may also include a thread reeling mechanism that reel out the bobbin thread L. The configuration, arrangement, etc. of the tensioning mechanism 13 may be changed as needed. The tension applying mechanism 13 may be provided with a solenoid capable of changing the biasing force applied to the thread tension discs 26, 27, instead of the thread tension motor 25. In this case, the CPU 91 may drive the solenoid to reduce the tension of the upper thread U in the processing of S10.

[0064] The configurations, arrangements, etc. of the fixed blade 61, the movable blade 62, and the cutting mechanism 60 may be changed as appropriate. The cutting edge 612 of the fixed blade 61 may extend horizontally. The fixed blade 61 and the movable blade 62 may be configured to cut only either the upper thread U or the bobbin thread L. The configuration of the shuttle mechanism 50 may be changed as appropriate, and the shuttle mechanism 50 may include a vertical shuttle.

[0065] The program including the commands for the sewing device 1 to perform the main processing may be stored in the storage device 94 before the CPU 91 executes the program. Therefore, the program acquisition method, acquisition path, and device for storing the program may each be changed as appropriate. The program executed by the CPU 91 may be received from another device via a cable or wireless communication and stored in a non-volatile storage device. The other device may include, for example, a PC or a server connected via a network.

[0066] A part or all of the processes performed by the sewing device 1 may be performed by an electronic device (e.g., an ASIC) separate from the CPU 91. The processes performed by the sewing device 1 may be distributed among multiple electronic devices (e.g., multiple CPUs). The order of each step of the processes performed by the sewing device 1 may be changed, steps may be omitted, or steps may be added as necessary. The scope of the present invention also includes an embodiment in which an operating system (OS) running on the sewing device 1 performs a part or all of each process in response to a command from the CPU 91.

[0067] The sewing device 1 may rotate the movable blade 62 at a low speed in the process of S17 without stopping the movable blade 62 at the stop position P4, within a range where the main shaft motor 21 is on the movable position P3 side of the cutting position P5. The stop position P4 may be changed as appropriate, and may be a position before the cutting position P5 where the upper thread U and the lower thread L are cut, where the horizontal distance from the cutting edge 612 of the fixed blade 61 to the lower thread scooping portion 623 or the blade portion 622 of the movable blade 62 is greater than 5 mm.

[0068] The standby position P1, the thread capturing position P2, the cutting position P5, the stop position P4, and the movable position P3 of the movable blade 62 may be changed as needed. The cutting position P5 and the standby position P1 may be different positions, or the cutting position P5 may be located between the movable position P3 and the standby position P1.

[0069] At least one of the process of moving the presser feet 9, 11 to the raised position in S10, the reduction process in S10, and the reeling process in S12 may be omitted or may be performed when an instruction from the operator is detected. If the sewing device 1 is equipped with a bobbin thread reeling mechanism that reels out the bobbin thread L, the process of S12 may drive the bobbin thread reeling mechanism to reel out the bobbin thread L. The cutting process in S14 may be performed with the outer presser bar 10 and the intermediate presser bar 8 in the lowered position. The cutting process in S14 may be performed with the same tension applied to the upper thread U as during sewing.

[0070] The above-mentioned modified examples may be combined as appropriate within the scope of not being inconsistent. The technology disclosed in this specification can be realized in various forms, for example, a method for controlling a sewing device, a computer program for realizing the above-mentioned method, and a recording medium on which the computer program is recorded. [Explanation of symbols]

[0071] 1:Sewing device 6: Needle bar 7: Sewing needle 13: Tensioning mechanism 14: Needle plate 17: Feed dog 23: Needle hole 33: Needle bar mechanism 40: Yarn reeling mechanism 60: Cutting mechanism 61: Fixed blade 62: Movable blade 69: Moving part 91: CPU 622:Blade 623: Lower thread scoop P1: Standby position P2: Thread capture position P3: Movable position P4: Stop position P5: Cutting position

Claims

1. a needle bar mechanism having a needle bar at the lower end of which a sewing needle can be attached, and which swings the needle bar up and down; a needle plate located below the needle bar; a feed dog that feeds the sewing material in at least one direction relative to the needle bar mechanism; A cutting mechanism capable of cutting a thread, a fixed blade fixed to the underside of the needle plate; a movable blade that is rotatable horizontally relative to the fixed blade; a blade moving unit that rotates the movable blade in the horizontal direction; the cutting mechanism having a control device for controlling the needle bar mechanism, the feed dog, and the cutting mechanism; The control device a sewing process of driving the needle bar mechanism and the feed dog to form a stitch on the sewing material with the thread; a thread catching process in which the movable blade is moved from a standby position to a thread catching position where the movable blade catches the thread, and further moved to a movable position on the opposite side of the standby position with respect to the thread catching position; a length adjustment process for positioning the lower end of the sewing needle above the needle plate while the movable blade has captured the thread through the thread capturing process, thereby making the sewing material movable; a cutting process in which, after the length adjusting process, the movable blade moves to a cutting position where it intersects with the fixed blade and cuts the yarn; A sewing device characterized by performing the steps of:

2. further comprising an input unit, The sewing device according to claim 1, wherein the thread capturing process and the length adjusting process are executed when an adjustment instruction for executing the length adjusting process is acquired by the input unit.

3. Further provided is a tensioning mechanism that applies tension to the thread, The control device 2. The sewing device according to claim 1, wherein the tension applying mechanism is driven during the length adjustment process to perform a reduction process in which the tension applied to the thread is reduced to a level lower than the tension during the sewing process.

4. Further provided is a yarn reeling mechanism that reels out the yarn, The control device 2. The sewing device according to claim 1, further comprising a reeling process for driving the thread reeling mechanism to reel out a predetermined amount of the thread during the length adjustment process.

5. 2. The sewing device according to claim 1, wherein the cutting position is the same as the standby position.

6. The control device In the length adjustment process, the movable blade is stopped at a stop position between the movable position and the cutting position, The sewing device according to claim 1, wherein the cutting process is executed when a cutting instruction for executing the cutting process is received.

7. The threads include an upper thread and a lower thread, the movable blade has a lower thread scooping portion capable of cutting the lower thread in cooperation with the fixed blade, and a blade portion capable of cutting the upper thread in cooperation with the fixed blade, 7. The sewing device according to claim 6, wherein the stop position is a position just before the lower thread and the upper thread are cut, and the horizontal distance from the tip of the fixed blade to the lower thread scooping portion or the blade portion of the movable blade is within 5 mm.

8. 2. The sewing device according to claim 1, wherein the thread includes an upper thread and a lower thread.

9. 9. The sewing device according to claim 1, wherein the feed dog has a needle hole through which the sewing needle can be inserted.

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