Thread trimming structure of sewing machine

Abstract

The utility model provides a thread trimming structure of a sewing machine, and belongs to the technical field of sewing machines. The thread trimming structure solves the problems that an existing thread trimming structure of the sewing machine is complex in structure and low in use reliability. According to the thread trimming structure of the sewing machine, the sewing machine comprises a machine base, the thread trimming structure comprises a movable cutter and an auxiliary cutter with an auxiliary cutting edge, the movable cutter is rotationally arranged on the machine base and can swing up and down around a rotating shuttle of the sewing machine, and a guide base is arranged on the machine base and located on the front side or the rear side of the movable cutter. The guide seat is provided with a guide groove formed in the front-back direction, a sliding block is slidably connected into the guide groove, the machine base is further provided with a driving mechanism capable of driving the sliding block to slide in a reciprocating mode, the auxiliary cutter is fixed to the sliding block, and an auxiliary cutting edge faces the movable cutter. When the sliding block gets close to the movable cutter, the end, with the auxiliary cutting edge, of the auxiliary cutter can abut against the upper side face of the movable cutter. The thread trimming structure of the sewing machine can simplify the structure and improve the use reliability.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sewing machine technical field relates to a sewing machine's thread cutting structure. BACKGROUND

[0002] Sewing machine is with one or more sewing thread, on the cloth forms one or more stitch, makes two or more cloth interweave or sew up the equipment. In order to improve sewing efficiency, sewing machine usually is equipped with thread cutting structure, and the sewing thread is cut off automatically through thread cutting structure, reduces the thread in clothes, improves the efficiency of subsequent arrangement.

[0003] Such as patent document (application number: 202411329869.0) discloses the thread cutting mechanism of double-moving knife, including first moving knife assembly, second moving knife assembly and drive assembly, first moving knife assembly and second moving knife assembly are rotatably sleeved on the outer circumferential side of adaptive rotating hook mechanism, with rotating hook mechanism as rotation axis, first moving knife assembly is used for hooking sewing thread, second moving knife assembly cooperates first moving knife assembly and is used as thread cutting, drive assembly includes first drive and second drive, two drive can adopt motor, first drive and second drive are indirectly driven first moving knife assembly and second moving knife assembly through sleeve rod structure one by one, sleeve rod structure includes transmission rod one and transmission rod two, transmission rod two is arranged in the inside of transmission rod one or is sleeved on the outside of transmission rod one, first drive drives transmission rod one to rotate through first transmission assembly, transmission rod one drives first moving knife assembly to swing, second drive drives transmission rod two to rotate through second transmission assembly, and transmission rod two drives second moving knife assembly to swing.

[0004] The structure adopts double-swinging moving knife assembly to cut thread, so first moving knife assembly and second moving knife assembly need to swing concentrically, which makes transmission rod one and transmission rod two need to be coaxially arranged, the coaxiality is required to be high, and if any one of transmission rod one and transmission rod two is out of axis, the other will be stuck, especially after the coaxiality of the two, each needs to be connected with the respective drive through the transmission assembly, which all leads to complex structure and reduces stability and reliability. SUMMARY

[0005] The utility model discloses a kind of thread cutting structures of sewing machine, the thread cutting structure of the sewing machine can simplify structure and improve use reliability.

[0006] The utility model discloses a sewing machine's thread cutting structure can be realized through the following technical scheme: a sewing machine's thread cutting structure, sewing machine includes the base, and the thread cutting structure includes the moving knife and the auxiliary knife with the auxiliary cutting edge, the moving knife rotation is arranged on the base and can swing around the rotating hook of sewing machine, characterized by, the base has the guide seat on, and the guide seat is located the front side or the back side of moving knife, and the guide groove along the front -back direction is arranged on the guide seat, and the sliding block is slidably connected in the guide groove, and the driving mechanism that can drive the sliding block reciprocating sliding is also established on the base, the auxiliary knife is fixed on the sliding block, and the auxiliary cutting edge is towards the moving knife, and when the sliding block is close to the moving knife, the one end of auxiliary cutting edge can press on the upper side of moving knife.

[0007] When needing cutting thread, the thread is located on the moving knife, the driving mechanism drives the sliding block to move close to the moving knife, the auxiliary cutting edge of the auxiliary knife towards the moving knife is close to the moving knife, until the lower side is pasted on the upper side of the moving knife, the auxiliary cutting edge can cut the thread when engaging with the moving knife. In which the guide seat is arranged on the base, the sliding block and the guide groove of the guide seat are slidably matched, the guide seat can guide the sliding block, so that the sliding block remains stable, and the stroke accuracy of the sliding block is higher, the auxiliary knife is fixed on the sliding block, the auxiliary knife determines the running track through the sliding block, so that the stability and stroke accuracy of the auxiliary knife can be guaranteed, and the use reliability is improved. Further, the moving knife is still rotationally arranged on the base, but the sliding block is slidably arranged on the front side or the back side of the moving knife, so that the installation and driving of the moving knife and the auxiliary knife do not interfere with each other, and are more stable and reliable. Compared with the coaxial rotation structure of the existing moving knife and auxiliary knife, the sliding connection structure of the sliding block and the guide seat is more simple and stable, and has higher reliability.

[0008] In the above-mentioned sewing machine's thread cutting structure, the opposite two side walls of the guide groove are provided with guide ribs along the front-back direction, the sliding block is slidably matched with the two groove walls of the guide groove, and the two guide ribs are respectively pasted on the two edges of the upper side of the sliding block. The guide seat guides the sliding of the sliding block, and the sliding block is limited in the guide groove through the guide ribs, so that the structure is simple and stable, and has high reliability.

[0009] In the above-mentioned sewing machine's thread cutting structure, the guide seat is blocky and is fixed on the base through fixing screws, and the guide seat is located on the front side of the moving knife. The guide seat is independently arranged, so that the machining accuracy of the guide groove is higher, the matching accuracy with the sliding block is improved, the running track is more accurate, then the guide seat is fixed on the base, so that the structure is simple and stable, and has high reliability.

[0010] In the thread trimming structure of the sewing machine, the driving mechanism comprises an auxiliary motor and a connecting rod, the auxiliary motor is fixed on the front side of the machine base, the motor shaft of the auxiliary motor is vertically upward, a crank is fixed on the end of the motor shaft of the auxiliary motor, one end of the connecting rod is hinged with the crank, and the other end is hinged with the sliding block. The straight-line motion sliding block is still driven by the auxiliary motor, and the auxiliary motor converts the rotation of the motor shaft into the straight-line motion of the sliding block through the crank and the connecting rod, so that the stroke accuracy is higher, and the structure is more stable and reliable. Of course, the driving mechanism can also use a gas cylinder, which is arranged in the front-rear direction and can push the sliding block forward and backward.

[0011] In the thread trimming structure of the sewing machine, the auxiliary knife is in a strip shape and arranged in the front-rear direction, and the front end of the auxiliary knife is fixed on the sliding block. The auxiliary blade is the end edge of the rear end of the auxiliary knife. The strip-shaped auxiliary knife has a certain distance between the sliding block and the moving knife, so that the rotation of the moving knife and the sliding of the sliding block do not interfere with each other, and the use reliability is improved.

[0012] In the thread trimming structure of the sewing machine, the front end of the auxiliary knife is in a straight shape and is horizontally fixed on the sliding block, and the rear end of the auxiliary knife is upwardly arc-shaped and higher than the moving knife. The straight front end of the auxiliary knife is fixed with the sliding block, so that the installation accuracy and connection reliability are higher, the rear end is upwardly arc-shaped, so that the auxiliary blade is closer to the upper needle plate, the thread ends on the cloth after thread trimming are shorter, the sewing quality is improved, and especially the shorter thread ends after the starting thread trimming make the bird nest prevention effect better.

[0013] In the thread trimming structure of the sewing machine, a mounting groove is formed on the upper side of the sliding block in the front-rear direction, a pressing plate is fixed in the mounting groove of the sliding block by locking screws, the front end of the auxiliary knife is inserted between the bottom surface of the mounting groove and the lower side of the pressing plate, the locking screws pass through the auxiliary knife, and the pressing plate is pressed downward on the auxiliary knife when the locking screws are locked. The front end of the auxiliary knife is fixed in the mounting groove by the pressing plate, the mounting groove can also limit the auxiliary knife, so that the installation of the auxiliary knife is more stable and reliable, and the disassembly, replacement, maintenance and the like are more convenient.

[0014] In the thread trimming structure of the sewing machine, the rear end of the pressing plate extends out of the sliding block, two screw holes are formed through the part of the pressing plate extending out of the sliding block, two adjusting studs are screwed in the two screw holes, and the lower ends of the two adjusting studs abut against the upper side of the part of the auxiliary knife extending out of the mounting groove. The part of the auxiliary knife extending out of the mounting groove is in a free state, and abuts against the lower end of the adjusting stud upward by its own elasticity, so that the height of the rear end of the auxiliary knife can be adjusted by rotating the adjusting stud, the parallelism and the pressing force when the auxiliary knife abuts against the moving knife are adjusted, and the thread trimming effect is adjusted.

[0015] In the thread cutting structure of the sewing machine, the upper side of the machine base is provided with a mounting notch, the guide seat is arranged in the mounting notch, a plurality of through holes are formed in the guide seat, and the fixing screws are screwed into the machine base through the through holes. The mounting notch can limit the guide seat and embed the guide seat in the mounting notch, thereby simplifying the structure. The guide seat is fixed to the machine base through the through holes, and the guide seat is convenient to disassemble and assemble.

[0016] In the thread cutting structure of the sewing machine, the upper side of the machine base is provided with a mounting notch, the guide seat is arranged in the mounting notch, a plurality of through holes are formed in the guide seat, and the fixing screws are screwed into the machine base through the through holes. The mounting notch can limit the guide seat and embed the guide seat in the mounting notch, thereby simplifying the structure. The guide seat is fixed to the machine base through the through holes, and the guide seat is convenient to disassemble and assemble.

[0017] Compared with the prior art, the thread cutting structure of the sewing machine has the following advantages:

[0018] 1. The guide seat is arranged on the machine base, the sliding block is in sliding connection with the guide groove of the guide seat, the guide seat can guide the sliding block, the sliding block is stable, the stroke accuracy of the sliding block is higher, the auxiliary cutter is fixed on the sliding block, the auxiliary cutter determines the running track through the sliding block, so that the stability and stroke accuracy of the auxiliary cutter are ensured, and the use reliability is improved, and the sliding connection structure of the sliding block and the guide seat is more simple and stable.

[0019] 2. The auxiliary cutter is fixed on the sliding block in front of the movable cutter, so that the installation and driving of the movable cutter and the auxiliary cutter are not interfered with each other, and are more stable and reliable.

[0020] 3. The rear end of the auxiliary cutter is upwardly arc-shaped, so that the auxiliary blade is closer to the upper needle plate, the thread end on the cloth after cutting is shorter, the sewing quality is improved, and the anti-bird nest effect is better especially for the shorter thread end after cutting of the starting sewing thread.

[0021] 4. The adjusting screw column is screwed at the rear end of the pressing plate, the lower ends of the adjusting screw columns abut against the upper side of the auxiliary cutter extension mounting groove portion, so that the height of the rear end of the auxiliary cutter can be adjusted by rotating the adjusting screw column, the parallelism and the pressing force of the auxiliary cutter and the movable cutter when abutting against each other are adjusted, and the thread cutting effect is adjusted. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a partial perspective view of the thread cutting structure.

[0023] Figure 2 is Figure 1An enlarged view of the structure at point A.

[0024] Figure 3 is a partial perspective view of another view of the shearing line structure.

[0025] Figure 4 is Figure 3 An enlarged view of the structure at point B.

[0026] Figure 5 is a partial structure plan view of the shearing line structure.

[0027] Figure 6 is Figure 5 A partial structure sectional view at point C-C.

[0028] Figure 7 is Figure 5 A partial structure sectional view at point D-D.

[0029] Figure 8 is Figure 5 A partial structure sectional view at point E-E.

[0030] Figure 9 is a partial structure view when the moving knife abuts against the auxiliary knife.

[0031] In the figure, 1 is a machine base; 11 is a mounting notch; 12 is a moving knife base; 13 is a rotating shuttle; 2 is a moving knife; 21 is a line separating tip; 22 is a line hooking groove; 23 is a moving knife blade edge; 3 is an auxiliary knife; 31 is an auxiliary blade edge; 4 is a sliding block; 41 is a mounting groove; 42 is a pressing plate; 43 is a locking screw; 44 is an adjusting stud; 5 is a guide base; 51 is a guide groove; 52 is a guide rib; 53 is a through hole; 54 is a fixing screw; 6 is a driving mechanism; 61 is an auxiliary motor; 62 is a connecting rod; 63 is a crank; and 7 is a main motor. DETAILED DESCRIPTION

[0032] The following is a specific embodiment of the present application and further describes the technical solution of the present application in combination with the accompanying drawings, but the present application is not limited to these embodiments.

[0033] For example, Figures 1 to 4As shown in the figure, a thread cutting structure of a sewing machine, the sewing machine comprises a machine base 1, a rotating hook shaft is rotatably connected to the machine base 1, a rotating hook 13 is arranged at the end of the rotating hook shaft, an annular movable cutter holder 12 is also rotatably connected to the machine base 1, the movable cutter holder 12 is coaxially arranged with the rotating hook 13, a needle plate is also horizontally fixed on the machine base 1, the needle plate has a needle hole, the movable cutter holder 12 and the rotating hook 13 are located below the needle plate. The thread cutting structure comprises a movable cutter 2 and an auxiliary cutter 3, the movable cutter 2 is in a sheet shape and is bent to be arc-shaped, one end of the movable cutter 2 is lap-joint fixed on the movable cutter holder 12, the movable cutter holder 12 can drive the movable cutter 2 to swing up and down around the rotating hook 13 shaft, the other end of the movable cutter 2 has a thread separating tip 21 arranged towards the back, a thread hooking groove 22 is also arranged on the movable cutter 2 in the front-rear direction, the side of the thread hooking groove 22 penetrates the edge of the movable cutter 2, and the rear end edge of the thread hooking groove 22 is a movable cutter edge 23. A guide holder 5 is fixed on the machine base 1, a guide groove 51 is arranged on the guide holder 5, the guide groove 51 is straight and arranged in the front-rear direction, a sliding block 4 is slidably connected in the guide groove 51, the sliding block 4 is located on the front side of the movable cutter 2, a driving mechanism 6 is also arranged on the machine base 1, which can drive the sliding block 4 to reciprocatingly slide along the guide groove 51, the auxiliary cutter 3 is in a strip shape and arranged in the front-rear direction, the front end of the auxiliary cutter 3 is fixed on the sliding block 4, and the rear end has an auxiliary cutter edge 31, the auxiliary cutter edge 31 faces the movable cutter 2, when the sliding block 4 approaches the movable cutter 2, one end of the auxiliary cutter edge 31 presses on the upper side of the movable cutter 2, and the auxiliary cutter edge 31 passes through the movable cutter edge 23.

[0034] Specifically, as shown in the figure, Figure 5 , Figure 6 the upper side of the machine base 1 has a mounting notch 11, the mounting notch 11 is located on the front side of the movable cutter 2, the guide holder 5 is arranged in the mounting notch 11, a plurality of through holes 53 are arranged through the guide holder 5, and fixed screws 54 are arranged in the through holes 53 and screwed on the machine base 1. The guide holder 5 is in a rectangular block shape, the guide groove 51 is arranged on the upper side of the guide holder 5, the opposite two side walls of the guide groove 51 have guide ribs 52 arranged in the front-rear direction, the sliding block 4 is slidably arranged in the guide groove 51, and the two guide ribs 52 are respectively attached to the two edges of the upper side of the sliding block 4, that is, the sliding block 4 is slidably connected to the guide holder 5 in the front-rear direction. The driving mechanism 6 comprises an auxiliary motor 61 and a connecting rod 62, the auxiliary motor 61 is fixed on the front side of the machine base 1, the motor shaft of the auxiliary motor 61 is vertically arranged upwards, a crank 63 is fixed on the end of the motor shaft of the auxiliary motor 61, the crank 63 is perpendicular to the motor shaft of the auxiliary motor 61, one end of the connecting rod 62 is hingedly connected to the crank 63, and the other end is hingedly connected to the sliding block 4. The machine base 1 also has a main motor 7, the motor shaft of the main motor 7 is parallel to the rotating hook 13 shaft, a lower swing arm is vertically fixed on the motor shaft of the main motor 7, the movable cutter holder 12 has an upper swing arm, and the upper swing arm and the lower swing arm are connected through a transmission arm.

[0035] As shown in the figure, Figures 7 to 9As shown, the upper side of the slider 4 is provided with a mounting groove 41 in the front-rear direction, the mounting groove 41 penetrates the rear end face of the slider 4, the slider 4 is fixed with a pressing plate 42 in the mounting groove 41 through a locking screw 43, the front end of the auxiliary cutter 3 is straight, and is inserted between the bottom face of the mounting groove 41 and the lower side of the pressing plate 42, the locking screw 43 penetrates the auxiliary cutter 3, and when the locking screw 43 is locked, the pressing plate 42 is pressed downward on the auxiliary cutter 3. The rear end of the auxiliary cutter 3 is upwardly arc-shaped and higher than the moving cutter 2, and the auxiliary blade edge 31 is the end edge of the rear end of the auxiliary cutter 3. The rear end of the pressing plate 42 extends out of the slider 4, and two screw holes are provided in the part of the pressing plate 42 extending out of the slider 4, two adjusting studs 44 are screwed in the two screw holes, and the lower ends of the two adjusting studs 44 abut against the upper side of the part of the auxiliary cutter 3 extending out of the mounting groove 41.

[0036] The specific embodiments described herein merely exemplify the spirit of the present application. Those skilled in the art to which the present application belongs can make various modifications or supplements to the described specific embodiments or use similar ways to replace, but will not deviate from the spirit of the present application or exceed the scope defined by the appended claims.

[0037] Although the terms such as the base 1, the mounting notch 11, and the moving cutter seat 12 are used more frequently herein, the possibility of using other terms is not excluded. The use of these terms is only for more conveniently describing and explaining the essence of the present application; any kind of additional limitation by interpreting them is contrary to the spirit of the present application.

Claims

1. A thread-cutting structure for a sewing machine, the sewing machine including a base (1), the thread-cutting structure including a movable blade (2) and an auxiliary blade (3) having an auxiliary cutting edge (31), the movable blade (2) being rotatably mounted on the base (1) and capable of swinging up and down around the sewing machine's shuttle (13), characterized in that, The base (1) has a guide seat (5) located on the front or rear side of the moving knife (2). The guide seat (5) has a guide groove (51) arranged in the front-rear direction. A slider (4) is slidably connected in the guide groove (51). The base (1) is also provided with a drive mechanism (6) that can drive the slider (4) to slide back and forth. The auxiliary knife (3) is fixed on the slider (4) and the auxiliary cutting edge (31) faces the moving knife (2). When the slider (4) moves closer to the moving knife (2), one end of the auxiliary knife (3) with the auxiliary cutting edge (31) can press against the upper side of the moving knife (2).

2. The thread-cutting structure of the sewing machine according to claim 1, characterized in that, The guide groove (51) has guide ribs (52) arranged in the front-back direction on both sides of its opposite side walls. The slider (4) slides with the two groove walls of the guide groove (51), and the two guide ribs (52) are respectively attached to the two sides of the upper side of the slider (4).

3. The thread-cutting structure of the sewing machine according to claim 2, characterized in that, The guide seat (5) is block-shaped and fixed to the machine base (1) by fixing screws (54). The guide seat (5) is located on the front side of the moving knife (2).

4. The thread-cutting structure of the sewing machine according to claim 1, 2, or 3, characterized in that, The drive mechanism (6) includes an auxiliary motor (61) and a connecting rod (62). The auxiliary motor (61) is fixed on the front side of the base (1), and the motor shaft of the auxiliary motor (61) is vertically upward. A crank (63) is fixed at the end of the motor shaft of the auxiliary motor (61). One end of the connecting rod (62) is hinged to the crank (63), and the other end is hinged to the slider (4).

5. The thread-cutting structure of the sewing machine according to claim 1, 2, or 3, characterized in that, The auxiliary blade (3) is long and is arranged in the front-to-back direction. The front end of the auxiliary blade (3) is fixed on the slider (4). The auxiliary cutting edge (31) is the end edge of the rear end of the auxiliary blade (3).

6. The thread-cutting structure of the sewing machine according to claim 5, characterized in that, The front end of the auxiliary blade (3) is straight and horizontally fixed on the slider (4), and the rear end of the auxiliary blade (3) is arched upward and higher than the moving blade (2).

7. The thread-cutting structure of the sewing machine according to claim 6, characterized in that, The upper side of the slider (4) is provided with an installation groove (41) along the front-back direction. The slider (4) is fixed with a pressure plate (42) in the installation groove (41) by a locking screw (43). The front end of the auxiliary knife (3) is inserted between the bottom surface of the installation groove (41) and the lower side of the pressure plate (42). The locking screw (43) passes through the auxiliary knife (3), and when the locking screw (43) is tightened, the pressure plate (42) presses down on the auxiliary knife (3).

8. The thread-cutting structure of the sewing machine according to claim 7, characterized in that, The rear end of the pressure plate (42) extends out of the slider (4), and two screw holes are provided through the part of the slider (4) extending out of the rear end of the pressure plate (42). Adjusting studs (44) are screwed into both screw holes, and the lower ends of the two adjusting studs (44) abut against the upper side of the part of the auxiliary knife (3) extending out of the mounting groove (41).

9. The thread-cutting structure of the sewing machine according to claim 3, characterized in that, The upper side of the base (1) has a mounting recess (11), the guide seat (5) is set in the mounting recess (11), and several through holes (53) are opened through the guide seat (5). The fixing screw (54) passes through the through holes (53) and is screwed onto the base (1).

10. The thread-cutting structure of the sewing machine according to claim 1, 2, or 3, characterized in that, A ring-shaped moving blade holder (12) is rotatably connected to the base (1). The moving blade (2) is in the shape of a plate, and one end of the moving blade (2) is fixed on the moving blade holder (12). The other end has a line-splitting tip (21) facing backward. A hook groove (22) is also provided on the moving blade (2) in the front-back direction. The rear edge of the hook groove (22) is the moving blade cutting edge (23). When the slider (4) moves backward, the auxiliary cutting edge (31) of the auxiliary blade (3) can pass through the moving blade cutting edge (23) of the moving blade (2).

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