CN214655668U - Sewing machine and thread trimming device thereof - Google Patents
Sewing machine and thread trimming device thereof Download PDFInfo
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- CN214655668U CN214655668U CN202120854532.7U CN202120854532U CN214655668U CN 214655668 U CN214655668 U CN 214655668U CN 202120854532 U CN202120854532 U CN 202120854532U CN 214655668 U CN214655668 U CN 214655668U
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Abstract
The utility model relates to a sewing machine technical field especially relates to a sewing machine's trimming device and sewing machine including this trimming device, this trimming device includes the motor, receive the motor drive and pivoted drive crank, locate the roller on the drive crank and the long crank that is connected with trimming mechanism, long crank includes drive division and spacing portion, the drive division has with roller matched with trimming profile face, trimming profile face is including receiving the roller drive and driving trimming mechanism and carry out the trimming section of trimming action, spacing portion has the medial surface, the medial surface sets up relatively with trimming section interval and forms a orbit groove, the roller is along the orbit groove motion when cutting the line section. The limiting part on the long crank limits the movement of the roller when the roller passes through the line shearing section on the long crank, so that the roller moves along the track groove on the long crank in a closed structure during line shearing, and the noise caused by hard contact collision between the roller and the track surface or the noise caused by throwing due to overhigh line shearing speed can be avoided.
Description
Technical Field
The utility model relates to a sewing machine technical field especially relates to a sewing machine's thread trimming device and a sewing machine including this thread trimming device.
Background
In a sewing machine, basic mechanisms for realizing the purpose of sewing are a needle bar mechanism, a thread hooking mechanism, a thread taking-up mechanism and a feeding mechanism, and the four mechanisms are all driven by the rotation of a main shaft. The thread trimming mechanism is used for achieving the thread trimming purpose, the middle-high end flat sewing machine in the current market drives the thread trimming mechanism to complete thread trimming actions through the stepping motor, so that the effects of low thread trimming sound and improved thread trimming stability can be achieved, and the sewing experience of a user is improved.
The utility model patent of publication number CN205088427U discloses a presser foot device is lifted to sewing machine's trimming to specifically disclose: the motor drives the thread cutting mechanism through the cam assembly, the cam assembly comprises a thread cutting crank and a cutter driving crank, the cutter driving crank is installed on one end shaft of the motor, the thread cutting crank is connected with the thread cutting hand rod, the thread cutting crank is eccentrically connected with the cutter driving crank, the motor drives the cutter driving crank to rotate, and the thread cutting mechanism is driven to perform thread cutting action through the thread cutting crank; the cutter driving crank is provided with a roller which is sleeved through a roller shaft, the tangent crank is provided with a groove, and the roller can rotate in the groove along with the cutter driving crank and drive the tangent crank. In the device, a motor drives a cam (a thread cutting crank) to rotate through a roller (a roller) arranged on a cutter driving crank so as to forcibly drive a thread cutting mechanism to complete thread cutting action or reset, so that the roller is in contact with different track surfaces during thread cutting or reset due to the track shape in the thread cutting crank, collision is generated, and noise is generated. Meanwhile, by analyzing the product applied by the technology, a torsion spring is arranged between a tangent crank and a tangent hand lever, and the cam structure adopted by the device is a force closed structure and is influenced by the force retaining effect of the torsion spring, so that if the rotating speed of the motor is too high, the force of the torsion spring is difficult to retain, the noise during trimming is easily caused by repeated throwing of the cam, and the rotating speed of the motor is controlled by the rotating speed during trimming of the main shaft, therefore, the trimming control method is adopted, the rotating speed of the motor is reduced as far as possible under the premise that the trimming action can be completed by matching with the angle of the main shaft, the rotating speed is defined for many times according to the arc surface of the cam in the rotating process of the motor, the rotating speed of the motor cannot be defined by a simple function, an electric control function can be defined and compiled only under the condition of the fixed trimming rotating speed of the main shaft, all the rotating speeds of the main shaft cannot be linked, and if the rotating speed of the main shaft changes, the electronic control program needs to be modified again, so that the thread cutting speed in the device is fixed, and the thread cutting speed cannot be adjusted to be increased due to the slow thread cutting speed.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is to provide a thread trimming device of sewing machine can not produce because of thread trimming speed is too fast and jump and arouse the noise to overcome prior art's above-mentioned defect.
In order to solve the technical problem, the utility model discloses a following technical scheme:
the utility model provides a sewing machine's trimming device, which comprises a motor, receive the motor drive and pivoted drive crank, locate the last roller of drive crank and the long crank that is connected with trimming mechanism, long crank includes drive division and spacing portion, the drive division have with roller matched with trimming profile face, trimming profile face is including receiving the roller drive and driving the trimming section that trimming mechanism carried out the trimming action, spacing portion has the medial surface, the medial surface sets up a formation orbit groove with trimming section interval relatively, the roller is along the motion of orbit groove when cutting the line section.
Preferably, the inner side surfaces are parallel to the thread trimming sections and are each in contact with the outer peripheral surface of the roller.
Preferably, the limiting part is also provided with a connecting surface, and the connecting surface is connected with the inner side surface and forms a U-shaped groove with the trimming line section.
Preferably, the trimming line profile further comprises a base circle segment connected to the trimming line segment, and the base circle segment is concentrically arranged with the rotation center of the driving crank.
Preferably, the thread cutting mechanism comprises a rotatable thread cutting spool and a thread cutting assembly connected with one end of the thread cutting spool, and the long crank is arranged at the other end of the thread cutting spool.
Preferably, the thread cutting assembly comprises a thread cutting crank, a thread cutting connecting rod, a movable cutter crank, a movable cutter and a fixed cutter, one end of the thread cutting crank is mounted on the thread cutting shaft, the other end of the thread cutting crank is hinged to one end of the thread cutting connecting rod, the other end of the thread cutting connecting rod is hinged to one end of the movable cutter crank, the movable cutter is mounted at the other end of the movable cutter crank, and the fixed cutter is mounted on a bottom plate of the sewing machine.
Preferably, the thread cutting mechanism further comprises a shaft sleeve arranged on the bottom plate of the sewing machine and a torsion spring sleeved on the shaft sleeve, the thread cutting shaft penetrates through the shaft sleeve, and two ends of the torsion spring are respectively abutted to the bottom plate and the thread cutting assembly.
The utility model also provides a sewing machine, include as above sewing machine's trimming device.
Compared with the prior art, the utility model discloses the progress that has showing:
the motion when through the last spacing portion of long crank to the roller through the long crank on the line of cutting segment plays limiting displacement for the line of cutting is carried out the roller and is followed this closed structure motion of long crank on the orbit groove, consequently can not be like the cam structure of power closed type among the prior art because of roller and the rigid contact collision of orbit face produce the noise or because of the line cutting speed is too fast and throw the jump and arouse the noise, so need not come the noise reduction through reducing the line cutting speed, therefore, the utility model discloses can realize the relatively fast line of cutting of cooperation sewing machine main shaft rotational speed and the synchronous control of line cutting speed matching main shaft rotational speed, satisfy the requirement that the line cutting sound is low, the line cutting stability is good simultaneously.
Drawings
Fig. 1 is a schematic structural view of a thread trimming device of a sewing machine according to an embodiment of the present invention.
Fig. 2 is a schematic view showing the cooperation between the roller on the driving crank and the long crank in the thread trimming device of the sewing machine according to the embodiment of the present invention.
Fig. 3 is a schematic structural view of a thread trimming device of a sewing machine according to an embodiment of the present invention, which is provided with a presser foot lifting mechanism.
Fig. 4 is a schematic structural view of a presser foot lifting cam of the presser foot lifting mechanism in fig. 3.
Fig. 5 is a schematic view of the structure of the presser foot lifting mechanism in fig. 3.
Fig. 6 is a timing diagram illustrating a thread trimming control method of a sewing machine according to an embodiment of the present invention.
Fig. 7 is a schematic view of the correspondence between the motor angle and the main shaft angle in the thread trimming control method of the sewing machine according to the embodiment of the present invention.
Fig. 8 is a logic diagram of the thread trimming control of the method of controlling the thread trimming of the sewing machine according to the embodiment of the present invention.
Fig. 9 is a timing diagram illustrating a method for controlling a thread cutting operation of a sewing machine according to an embodiment of the present invention, including a presser foot lifting control.
Fig. 10 is a schematic diagram of a presser foot lifting control logic in the case where the thread trimming control method of the sewing machine according to the embodiment of the present invention includes the presser foot lifting control.
Wherein the reference numerals are as follows:
1. motor 10 and rotating shaft
11. Motor support 2 and driving crank
3. Roller 4, long crank
41. Drive part 410, trimming profile surface
4101. Shear line segment 4102, base circle segment
42. A limit part 420 and an inner side surface
421. Connection surface 43, track groove
5. Thread trimming mechanism 51 and thread trimming shaft
52. Trimming crank 53, trimming connecting rod
54. Moving knife crank 55, moving knife
56. Stationary knife 57 and shaft sleeve
58. Torsion spring 6, lift presser foot cam
60. Lift presser foot profile 601, lift presser foot base circle section
602. Lifting presser foot execution section 603 and presser foot height maintaining section
7. Lift presser foot roller 8, lift presser foot drive crank
9. Lift presser foot mechanism 91, lift presser foot crank axle
92. Lift presser foot axle sleeve 93, lift presser foot lower crank
94. Top rod 95, rear lever
96. Pull rod 97 and front lever
98. Pulling block 99, stop block
101. Presser foot rod 102, presser foot subassembly
103. Pressure foot spring
Detailed Description
The following describes the present invention in further detail with reference to the accompanying drawings. These embodiments are provided only for illustrating the present invention and are not intended to limit the present invention.
In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.
In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.
As shown in fig. 1 to 10, the present invention relates to a thread cutting device of a sewing machine.
Referring to fig. 1, the thread trimming device of the sewing machine of the present embodiment includes a motor 1, a driving crank 2, a roller 3, a long crank 4, and a thread trimming mechanism 5. The motor 1 may be fixedly installed on a bed plate of the sewing machine through a motor bracket 11. The motor 1 is provided with a rotating shaft 10, one end of the driving crank 2 is fixedly arranged on the rotating shaft 10 of the motor 1, the driving crank 2 is driven by the rotating shaft 10 of the motor 1 to synchronously rotate with the rotating shaft 10 of the motor 1, and the rotating center of the driving crank 2 is the axis of the rotating shaft 10 of the motor 1. Preferably, the motor 1 is a stepping motor, and can precisely control the rotation speed and the rotation angle of the rotary shaft 10. The roller 3 is arranged at the other end of the driving crank 2, and the driving crank 2 drives the roller 3 to rotate synchronously therewith when rotating, so that the rotation center of the roller 3 is also the axis of the rotating shaft 10 of the motor 1. Preferably, the roller 3 may be rotatably mounted on the drive crank 2 by a pin. The long crank 4 is connected with a thread trimming mechanism 5. Referring to fig. 2, the long crank 4 includes a driving portion 41 and a stopper portion 42. The driving portion 41 has a trimming contour surface 410 matching with the roller 3, the trimming contour surface 410 includes a trimming segment 4101 driven by the roller 3 to drive the trimming mechanism 5 to perform trimming, that is, when the motor 1 rotates the rotating shaft 10 to drive the driving crank 2 and the roller 3 to rotate, the roller 3 acts on the trimming segment 4101 of the trimming contour surface 410 of the driving portion 41 of the long crank 4 and moves along the trimming segment 4101 to drive the long crank 4 to rotate, and the rotation of the long crank 4 drives the trimming mechanism 5 to perform trimming. The limiting part 42 has an inner side surface 420, the inner side surface 420 of the limiting part 42 and the trimming section 4101 of the trimming contour surface 410 of the driving part 41 are oppositely arranged at intervals to form a track groove 43, and the roller 3 moves along the track groove 43 when passing through the trimming section 4101. The limiting part 42 is used for limiting the movement of the roller 3 when the roller passes through the thread cutting section 4101, so that the roller 3 moves along the track groove 43 on the long crank 4 in a closed structure during thread cutting, and therefore, noise caused by hard contact collision between the roller and a track surface or noise caused by throwing and jumping due to overhigh thread cutting speed can be avoided unlike a force closed cam structure in the prior art, and the noise is not required to be reduced by reducing the thread cutting speed.
Referring to fig. 2, in the present embodiment, preferably, the inner side surface 420 of the limit portion 42 of the long crank 4 is parallel to the trimming section 4101 of the trimming contour surface 410 of the driving portion 41 and is in contact with the outer peripheral surface of the roller 3, that is, the roller 3 keeps in contact with the inner side surface 420 of the limit portion 42 and the trimming section 4101 of the trimming contour surface 410 of the driving portion 41 when moving along the track groove 43, so that the roller 3 is ensured not to collide or jump and generate noise when moving in the track groove 43.
Further, in this embodiment, the limiting portion 42 of the long crank 4 further has a connecting surface 421, the connecting surface 421 connects the inner side surface 420 of the limiting portion 42 and the trimming section 4101 of the trimming contour surface 410 of the driving portion 41 to form a U-shaped groove, that is, the track groove 43 is a U-shaped groove with one end closed, and the connecting surface 421 connects the trimming section 4101 with the inner side surface 420 at the trimming end of the trimming section 4101, therefore, when the wire is cut, the roller 3 enters the U-shaped groove from the open end of the U-shaped groove and moves to the closed end of the U-shaped groove along the U-shaped groove, that is, the end of the trimming in the trimming section 4101, the trimming mechanism 5 is driven to perform the trimming operation, so that, when the trimming is completed, the roller 3 is also in the closed configuration, namely, the U-shaped track groove 43 ensures that the roller 3 moves in a closed structure when the trimming is performed and the trimming is reset, thereby further ensuring that the noise caused by the throwing jump caused by the excessively high trimming speed can not occur.
Referring to fig. 1, in the present embodiment, the thread cutting mechanism 5 may preferably include a thread cutting spool 51 and a thread cutting assembly, wherein the thread cutting spool 51 is rotatably supported on a base plate of the sewing machine, the thread cutting assembly is connected to one end of the thread cutting spool 51, and the long crank 4 is provided at the other end of the thread cutting spool 51. The long crank 4 and the shear line shaft 51 can be in a split structure, and the long crank 4 is fixedly arranged at the other end of the shear line shaft 51; the long crank 4 and the shear spool 51 may also be of one-piece, unitary construction. When the roller 3 acts on the trimming segment 4101 of the trimming contour surface 410 of the driving portion 41 of the long crank 4 to drive the long crank 4 to rotate, the rotation of the long crank 4 drives the trimming shaft 51 to rotate, and the rotation of the trimming shaft 51 drives the trimming assembly to perform the trimming operation.
In this embodiment, the structure of the thread cutting assembly is not limited, and any thread cutting assembly structure capable of performing thread cutting operation by driving the rotation of the thread cutting shaft 51 in the prior art may be adopted. Preferably, referring to fig. 1, the thread cutting assembly may include a thread cutting crank 52, a thread cutting connecting rod 53, a movable cutter crank 54, a movable cutter 55 and a fixed cutter 56, wherein one end of the thread cutting crank 52 is fixedly mounted on the thread cutting shaft 51, the other end of the thread cutting crank 52 is hinged to one end of the thread cutting connecting rod 53, the other end of the thread cutting connecting rod 53 is hinged to one end of the movable cutter crank 54, the movable cutter 55 is fixedly mounted on the other end of the movable cutter crank 54, and the fixed cutter 56 is fixedly mounted on a bottom plate of the sewing machine. When the thread cutting shaft 51 rotates, the thread cutting crank 52 is driven to rotate, the thread cutting crank 52 drives the thread cutting connecting rod 53 and the movable knife crank 54 to rotate, the movable knife crank 54 drives the movable knife 55 to move towards the fixed knife 56, the movable knife 55 firstly hooks a thread to be cut and drives the thread to move towards the fixed knife 56 to complete thread separation in the process of moving towards the fixed knife 56, and then the thread is driven to continuously move towards the fixed knife 56 to be meshed with the fixed knife 56 to cut the thread, so that thread cutting is completed.
Further, the thread trimming mechanism 5 of the embodiment further includes a shaft sleeve 57 and a torsion spring 58, the shaft sleeve 57 is fixedly mounted on the bottom plate of the sewing machine, the torsion spring 58 is sleeved on the shaft sleeve 57, the thread trimming shaft 51 rotatably penetrates through the shaft sleeve 57, and two ends of the torsion spring 58 respectively abut against the bottom plate of the sewing machine and the thread trimming crank 52 of the thread trimming assembly. The torsion spring 58 can drive the thread cutting mechanism 5 and the long crank 4 to move reversely to reset after the thread cutting mechanism 5 finishes thread cutting. When the thread trimming device of the sewing machine of the embodiment is used, after the motor 1 drives the thread trimming mechanism 5 to complete thread trimming, the motor 1 reverses and rotates reversely, and the thread trimming mechanism 5 and the long crank 4 reset under the combined action of the torsion spring 58 and the motor 1.
Referring to fig. 2, in the present embodiment, preferably, the trimming contour surface 410 of the driving portion 41 of the long crank 4 further includes a base circle segment 4102, one end of the trimming segment 4101 is a trimming end, the base circle segment 4102 is connected to the other end of the trimming segment 4101, the base circle segment 4102 is an arc segment, and the base circle segment 4102 is concentrically disposed with the rotation center of the driving crank 2, so that the roller 3 rotates synchronously with the driving crank 2 and does not drive the long crank 4 to rotate when moving along the base circle segment 4102, and at this time, the long crank 4 performs an idle stroke, and the trimming mechanism 5 does not operate. The base circle section 4102 can leave the idle stroke of the thread trimming mechanism 5 for other actuating mechanisms (such as a presser foot lifting mechanism, a tooth height adjusting mechanism and the like) driven by the motor 1, thereby realizing multiple functions by being driven by one motor 1. Preferably, the motor 1 can be a dual output shaft motor, the driving crank 2 is arranged on a rotating shaft at one side of the dual output shaft motor, and the other actuating mechanism is arranged on a rotating shaft at the other side of the dual output shaft motor.
Taking the example that the motor 1 drives the presser foot lifting mechanism to realize the function of lifting the presser foot at the same time, referring to fig. 3, the motor 1 is a motor with double output shafts, the driving crank 2 is fixedly arranged on a rotating shaft 10 at one side of the motor 1, and the other side of the motor 1 is provided with a presser foot lifting cam 6, a presser foot lifting roller 7, a presser foot lifting driving crank 8 and a presser foot lifting mechanism 9. The pressure raising and pressing foot cam 6 is fixedly arranged on a rotating shaft 10 at the other side of the motor 1, the pressure raising and pressing foot cam 6 is driven by the rotating shaft 10 of the motor 1 to synchronously rotate with the rotating shaft 10 of the motor 1, and the rotating center of the pressure raising and pressing foot cam 6 is the axis of the rotating shaft 10 of the motor 1. The presser foot lifting roller 7 is provided at one end of the presser foot lifting drive crank 8, and preferably, the presser foot lifting roller 7 may be rotatably mounted on the presser foot lifting drive crank 8 through a pin shaft. The other end of the presser foot lifting driving crank 8 is connected with a presser foot lifting mechanism 9. Referring to fig. 4, the presser foot lifting cam 6 has a presser foot lifting contour 60 cooperating with the presser foot lifting roller 7, and the presser foot lifting roller 7 is pressed against the presser foot lifting contour 60. The presser foot lifting contour surface 60 comprises a presser foot lifting base circle section 601, a presser foot lifting execution section 602 and a presser foot height maintaining section 603 which are sequentially connected, wherein the presser foot lifting base circle section 601 and the presser foot height maintaining section 603 are both arc sections taking the rotation center of the presser foot lifting cam 6 as the center, the presser foot lifting execution section 602 is connected with the presser foot lifting base circle section 601 and the presser foot height maintaining section 603, and the distance between the presser foot lifting execution section 602 and the rotation center of the presser foot lifting cam 6 is gradually increased. When the rotating shaft 10 of the motor 1 rotates to make the roller 3 move along the trimming section 4101 of the trimming contour surface 410 of the driving part 41 in the track groove 43 on the long crank 4, namely when the motor 1 drives the trimming mechanism 4 to trim and reset, the presser foot lifting cam 6 rotates along the rotating shaft 10 of the motor 1 and the presser foot lifting roller 7 moves along the presser foot lifting base circle section 601 of the presser foot lifting cam 6 without driving the presser foot lifting driving crank 8 to rotate, so that the presser foot lifting mechanism 9 executes an idle stroke and the presser foot lifting mechanism 9 does not act. After the resetting of the trimming is completed, the rotating shaft 10 of the motor 1 continues to rotate, the roller 3 moves along the base circle section 4102 of the trimming contour surface 410 of the driving part 41 of the long crank 4, so that the long crank 4 executes an idle stroke, the trimming mechanism 5 does not act, the presser foot lifting roller 7 enters the presser foot lifting execution section 602 from the presser foot lifting base circle section 601 of the presser foot lifting cam 6 and moves along the presser foot lifting execution section 602, the presser foot lifting execution section 602 drives the presser foot lifting roller 7 to drive the presser foot lifting driving crank 8 to rotate, and the presser foot lifting mechanism 9 is driven by the rotation of the presser foot lifting driving crank 8 to execute the presser foot lifting action. When the presser foot lifting roller 7 moves to the intersection point of the presser foot lifting execution section 602 and the presser foot height maintaining section 603 along the presser foot lifting execution section 602, the presser foot is lifted to the highest height position, the presser foot lifting action is completed, the rotating shaft 10 of the motor 1 continues to rotate, the presser foot lifting roller 7 enters the presser foot height maintaining section 603 and moves along the presser foot height maintaining section 603 without driving the presser foot lifting driving crank 8 to rotate, so that the presser foot lifting mechanism 9 does not act, the presser foot is maintained at the highest height position at the moment, and since the contact force between the presser foot lifting roller 7 and the presser foot lifting cam 6 and the presser foot height maintaining section 603 just points to the center of the presser foot lifting cam 6 at the moment, the tangential force does not exist, the actual load of the motor 1 when the presser foot is maintained at the highest height position can be reduced, and the service life of the motor 1 is prolonged. Then the rotating shaft 10 of the motor 1 rotates reversely, so that the presser foot lifting roller 7 moves reversely along the presser foot lifting contour surface 60 of the presser foot lifting cam 6 to return to the presser foot lifting base circle section 601, and the presser foot lifting mechanism 9 can be reset.
Referring to fig. 3, the presser foot lifting mechanism 9 may include a presser foot lifting crankshaft 91, a presser foot lifting bushing 92, a presser foot lifting lower crank 93, a top bar 94, a rear lever 95, a pull rod 96, a front lever 97, a pull block 98, and a stopper 99. The presser foot lifting shaft sleeve 92 is fixedly installed on a bottom plate of the sewing machine, and the presser foot lifting crank shaft 91 is rotatably arranged through the presser foot lifting shaft sleeve 92. The presser foot lifting roller 7 is provided at one end of the presser foot lifting drive crank 8, and the other end of the presser foot lifting drive crank 8 is fixedly provided at one end of the presser foot lifting crank shaft 91. One end of the presser foot lifting and lowering crank 93 is fixedly arranged at the other end of the presser foot lifting and lowering crank shaft 91, the other end of the presser foot lifting and lowering crank 93 is hinged with one end of a top rod 94, and the other end of the top rod 94 is hinged with one end of a rear lever 95. The rear lever 95 is rotatably hinged to a housing of the sewing machine, the other end of the rear lever 95 is hinged to one end of a pull rod 96, and the other end of the pull rod 96 is hinged to one end of a front lever 97. The front lever 97 is rotatably hinged to a housing of the sewing machine, the other end of the front lever 97 is hinged to one end of the pull block 98, and the other end of the pull block 98 is in contact with the lower surface of the stopper 99. The stopper 99 is mounted on the upper end of a presser bar 101, and the lower end of the presser bar 101 is mounted with a presser foot assembly 102. When the presser foot lifting roller 7 moves along the presser foot lifting execution section 602 of the presser foot lifting cam 6, and the presser foot lifting execution section 602 drives the presser foot lifting roller 7 to drive the presser foot lifting driving crank 8 to rotate, the rotation of the presser foot lifting driving crank 8 can drive the presser foot crank shaft 91 and the presser foot lifting lower crank 93 to synchronously rotate, and the rotation of the presser foot lifting lower crank 93 drives the ejector rod 94, the rear lever 95, the pull rod 96, the front lever 97 and the pull block 98 to act, so that the pull block 98 lifts the stop block 99 to lift, thereby driving the presser foot rod 101 and the presser foot assembly 102 to lift, and realizing the presser foot lifting action. Referring to fig. 5, a presser bar 101 may be sleeved with a presser spring 103, and the presser lifting roller 7 may be constantly pressed against the presser lifting contour surface 60 of the presser lifting cam 6 by the spring force of the presser spring 103.
Based on the thread trimming device of the sewing machine, the embodiment further provides the sewing machine, and the sewing machine of the embodiment comprises the thread trimming device of the sewing machine of the embodiment.
Referring to fig. 6 to 10, the present embodiment further provides a trimming control method of the sewing machine based on the trimming device of the sewing machine. The thread trimming control method of the sewing machine of the present embodiment adopts the thread trimming device of the sewing machine of the present embodiment, and therefore, the thread trimming control method of the sewing machine of the present embodiment is also the working method of the thread trimming device of the sewing machine of the present embodiment. In the thread trimming device of the sewing machine according to the embodiment, a thread trimming interval EF is provided in a circle of the rotation shaft 10 of the motor 1 rotating around the axis of the rotation shaft 10, an end point E of the thread trimming interval EF is a thread trimming starting point, an end point F of the thread trimming interval EF is a thread trimming ending point, and a zero position of the motor (i.e., a zero position of the rotation shaft 10 of the motor 1) is provided at the thread trimming starting point, i.e., at the end point E of the thread trimming interval EF. When the rotating shaft 10 of the motor 1 rotates from the point E to the point F in the thread cutting interval EF, the thread cutting mechanism 5 is driven to complete thread cutting, and meanwhile, the main shaft of the sewing machine rotates by a thread cutting interval angle.
Referring to fig. 6, 7 and 8, the thread cutting control method of the sewing machine of the present embodiment is: when cutting threads, a main shaft of the sewing machine rotates from a main shaft angle A to a main shaft angle C at a main shaft rotating speed n, the main shaft angle A corresponds to a thread cutting starting point E point of a thread cutting interval EF of a rotating shaft 10 of the motor 1 and also corresponds to a motor zero position, the main shaft angle C corresponds to a thread cutting ending point F point of the thread cutting interval EF of the rotating shaft 10 of the motor 1, and a thread cutting interval angle of the main shaft is formed between the main shaft angle A and the main shaft angle C; meanwhile, the motor 1 rotates at a first motor speed n in the trimming interval EF1From the motor zero position to the motor angle a and at a second motor speed n2When the motor rotates from the motor angle a to the motor angle b, the roller 3 on the driving crank 2 moves along the track groove 43 on the long crank 4 under the driving of the motor 1 and drives the long crank 4 to drive the thread trimming mechanism 5 to complete thread trimming. The motor angle a corresponds to a branching time point D in the trimming interval EF and a spindle angle B between the spindle angle A and the spindle angle C, i.e. the motor 1 rotates at a first motor speed n in the trimming interval EF1When the thread cutting mechanism 5 rotates from the zero position of the motor to the angle a of the motor, the movable knife 55 in the thread cutting mechanism 5 is driven to move towards the fixed knife 56 and hook the thread to be cut and drive the thread to move towards the fixed knife 56 to complete thread separation, when a thread separation time point D is reached, the rotating shaft 10 of the motor 1 rotates from the zero position of the motor to the angle a of the motor, and the main shaft of the sewing machine rotates from the angle A of the main shaft to the angle B of the main shaft. Then, the motor 1 rotates at a second motor speed n within the trimming interval EF2And when the thread is cut, the movable knife 55 in the thread cutting mechanism 5 is driven to drive the thread to continuously move towards the fixed knife 56 to be meshed with the fixed knife 56, so that the thread is cut, the rotating speed of the main shaft of the sewing machine is unchanged, the main shaft is continuously rotated to a main shaft angle C from a main shaft angle B, and the motor angle B corresponds to a thread cutting end point F and the main shaft angle C in a thread cutting interval EF.
In the thread trimming control method of the sewing machine of the embodiment, because the roller 3 moves along the closed structure of the track groove 43 on the long crank 4 during thread trimming, noise caused by throwing due to too high thread trimming speed is avoided unlike the force closed cam structure in the prior art, and the noise is not reduced by reducing the thread trimming speed, the first motor rotating speed n during thread trimming can be defined by the determined related function of the main shaft rotating speed n1And a second motor speed n2The method specifically comprises the following steps: n is1＝K1f(n)，n2＝K2f′(n) and, n2>n1，K1And K2To set the coefficients, which are fixed values, f (n) and f′(n) is a set function, and the set function is a fixed function, K1、K2F (n) and f′(n) can be set according to the working parameters of the main shaft of the sewing machine in practical application. The speed of the motor 1 during the cutting of the thread is thus only dependent on the spindle speed n: if the main shaft rotating speed n is increased, the first motor rotating speed n1And a second motor speed n2The synchronous increase enables the thread cutting speed to be faster and the thread cutting time to be shorter; if the main shaft speed n is reduced, the first motor speed n1And a second motor speed n2The synchronous reduction enables the thread cutting speed to be slower and the thread cutting time to be longer; when the spindle rotation speed n changes, the correspondence between the motor angle of rotation of the rotating shaft 10 of the motor 1 and the spindle angle of rotation of the spindle is always maintained. Therefore, the thread cutting control method of the sewing machine of the embodiment can realize the adjustment control of the thread cutting speed only by adjusting the rotation speed n of the main shaft when the thread is cut if necessary. In addition, the thread trimming control method of the sewing machine of the embodiment enables the motor 1 to rotate at the first motor speed n in the thread trimming interval EF at the initial thread trimming stage1Slave motor zeroThe position is rotated to a motor angle a, the first motor speed n1The angle of the motor is matched with the angle of the main shaft, the movable knife 55 can hook the suture, and then the motor 1 rotates at the second motor speed n in the thread cutting interval EF2From motor angle a to motor angle b, the second motor speed n2Greater than the first motor speed n1Therefore, the thread cutting can be accelerated after the movable knife 55 is ensured to hook the thread, and the thread cutting action can be completed quickly.
Further, referring to fig. 8, in the trimming control method of the sewing machine of the embodiment, after the trimming mechanism 5 completes the trimming operation, the motor 1 rotates at the third motor speed n within the trimming interval EF3The wire cutting mechanism 5 and the long crank 4 are reset under the combined action of the torsion spring 58 and the motor 1, and n is that the wire cutting mechanism rotates from the motor angle b to the motor zero position, namely the rotating shaft 10 of the motor 1 is reversely rotated and reset to drive the driving crank 2 and the roller 3 to reversely move and reset, and the wire cutting mechanism 5 and the long crank 4 are reset under the combined action of the torsion spring 58 and the motor 13<n4，n4The rotating speed of the long crank 4 is reset under the independent action of the torsion spring 58 for the thread cutting mechanism 5 and the long crank 4. Therefore, after the thread trimming mechanism 5 and the long crank 4 are reset, when the roller 3 continues to move along the base circle section 4102 of the thread trimming contour surface 410 of the driving part 41 of the long crank 4 to drive the long crank 4 to execute the idle stroke, the roller 3 is always kept in contact with the base circle section 4102, the buffer effect is achieved, and the noise caused by collision due to the fact that the front and back positions of the roller 3 and the long crank 4 are different due to the fact that the resetting speed of the torsion spring 58 is too high is prevented.
Referring to fig. 9 and 10, when the motor 1 is a dual output shaft motor, the driving crank 2 is fixedly mounted on the rotating shaft 10 on one side of the motor 1, and the presser foot lifting cam 6, the presser foot lifting roller 7, the presser foot lifting driving crank 8 and the presser foot lifting mechanism 9 are arranged on the other side of the motor 1, the thread trimming control method of the sewing machine of the embodiment further includes presser foot lifting control. At this time, a presser foot lifting interval EG and a presser foot height maintaining interval GH are further arranged in one circle of the rotation shaft 10 of the motor 1 rotating around the axis of the rotation shaft 10, the presser foot height maintaining interval GH, the presser foot lifting interval EG and the thread trimming interval EF are sequentially connected, an end point E point of the presser foot lifting interval EG is a presser foot height lowest point (also referred to as a motor zero position), and an end point G point of the presser foot lifting interval EG is a presser foot height highest point. When the rotating shaft 10 of the motor 1 rotates from the point E to the point F in the trimming interval EF, the trimming mechanism 5 is driven to finish trimming, then the rotating shaft 10 of the motor 1 reversely rotates from the point F to return to the point E, the trimming mechanism 5 is driven to reset, in the process, the presser foot lifting roller 7 moves along the presser foot lifting base circle section 601 of the presser foot lifting cam 6, and the presser foot lifting mechanism 9 does not act. When the rotating shaft 10 of the motor 1 rotates from the point E to the point G in the presser foot lifting interval EG, the presser foot lifting mechanism 9 is driven to complete the presser foot lifting action, so that the presser foot is lifted to the highest point of the presser foot height, then the rotating shaft 10 of the motor 1 continuously rotates from the point G to the point H in the presser foot height maintaining interval GH, so that the presser foot is maintained at the highest point of the presser foot height, then the rotating shaft 10 of the motor 1 reversely rotates from the point H to return to the point E, so that the presser foot lifting mechanism 9 is reset, in the process, the roller 3 moves along the base circle section 4102 of the trimming profile surface 410 of the driving part 41 of the long crank 4, the long crank 4 executes the idle stroke, and the trimming mechanism 5 does not act.
Therefore, after the thread trimming mechanism 5 finishes the thread trimming action and resets, namely the rotating shaft 10 of the motor 1 resets to the zero position of the motor, the motor 1 can rotate at the fifth motor speed n within the presser foot lifting interval EG5And rotating from the zero position E point of the motor to the highest point G of the presser foot height, driving the presser foot lifting mechanism 9 to complete the presser foot lifting action, so that the presser foot is lifted to the highest point of the presser foot height, and then continuously rotating from the point G to the point H in a presser foot height maintaining interval GH by the motor 1 so that the presser foot is maintained at the highest point of the presser foot height. The presser foot lifting mechanism 9 may be driven to lift and hold the presser foot to the designated presser foot lifting height value by controlling the rotation angle of the motor 1 in the presser foot lifting interval EG. After the presser foot height is kept for the set time, the motor 1 rotates at a sixth motor speed n6The pressure foot lifting mechanism 9 is reset under the combined action of the pressure foot spring 103 and the motor 1, and n is that the pressure foot lifting mechanism is reset6<n7，n7The rotating speed of the presser foot lifting driving crank 8 is raised when the presser foot lifting driving crank 8 and the presser foot lifting mechanism 9 are reset under the independent action of the presser foot spring 103. Let n be6<n7The function of slow falling of the presser foot can be realized when the motor 1 and the presser foot spring 103 jointly drive the presser foot lifting mechanism 9 to reset, thereby greatly reducing the number of the presser feetResetting the noise of collision when descending.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and replacements can be made without departing from the technical principle of the present invention, and these modifications and replacements should also be regarded as the protection scope of the present invention.
Claims (8)
1. A thread trimming device of a sewing machine is characterized by comprising a motor (1), a driving crank (2) driven by the motor (1) to rotate, a roller (3) arranged on the driving crank (2) and a long crank (4) connected with a thread trimming mechanism (5), the long crank (4) comprises a driving part (41) and a limiting part (42), the driving part (41) is provided with a trimming contour surface (410) matched with the roller (3), the trimming contour surface (410) comprises trimming sections (4101) which are driven by the roller (3) to drive the trimming mechanism (5) to perform trimming action, the limiting part (42) is provided with an inner side surface (420), the inner side surface (420) and the shearing line segment (4101) are oppositely arranged at intervals to form a track groove (43), the roller (3) moves along the track groove (43) when passing through the shear line segment (4101).
2. The thread trimming device of a sewing machine according to claim 1, wherein the inner side surface (420) is parallel to the trimming section (4101) and is in contact with the outer peripheral surface of the roller (3).
3. The trimming device of a sewing machine according to claim 1, wherein the limiting portion (42) further has a connecting surface (421), and the connecting surface (421) connects the inner side surface (420) and the trimming section (4101) to form a U-shaped groove.
4. The thread trimming device of a sewing machine according to claim 1, wherein the trimming contour surface (410) further comprises a base circle segment (4102) connected to the trimming segment (4101), the base circle segment (4102) being concentrically arranged with a rotation center of the driving crank (2).
5. The thread cutting device of a sewing machine according to claim 1, characterized in that the thread cutting mechanism (5) comprises a rotatable thread cutting spool (51) and a thread cutting assembly connected to one end of the thread cutting spool (51), and the long crank (4) is provided at the other end of the thread cutting spool (51).
6. The thread trimming device of the sewing machine according to claim 5, wherein the thread trimming assembly comprises a thread trimming crank (52), a thread trimming connecting rod (53), a movable cutter crank (54), a movable cutter (55) and a fixed cutter (56), one end of the thread trimming crank (52) is mounted on the thread trimming shaft (51), the other end of the thread trimming crank is hinged to one end of the thread trimming connecting rod (53), the other end of the thread trimming connecting rod (53) is hinged to one end of the movable cutter crank (54), the movable cutter (55) is mounted on the other end of the movable cutter crank (54), and the fixed cutter (56) is mounted on a bottom plate of the sewing machine.
7. The thread trimming device of sewing machine according to claim 5, wherein the thread trimming mechanism (5) further comprises a shaft sleeve (57) mounted on a bottom plate of the sewing machine and a torsion spring (58) sleeved on the shaft sleeve (57), the thread trimming shaft (51) is arranged through the shaft sleeve (57), and two ends of the torsion spring (58) are respectively abutted against the bottom plate and the thread trimming assembly.
8. A sewing machine characterized by comprising the thread trimming device of the sewing machine according to any one of claims 1 to 7.
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| CN202120854532.7U CN214655668U (en) | 2021-04-23 | 2021-04-23 | Sewing machine and thread trimming device thereof |
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| CN202120854532.7U CN214655668U (en) | 2021-04-23 | 2021-04-23 | Sewing machine and thread trimming device thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022222487A1 (en) * | 2021-04-23 | 2022-10-27 | 杰克科技股份有限公司 | Sewing machine, thread cutting apparatus thereof, and thread cutting control method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022222487A1 (en) * | 2021-04-23 | 2022-10-27 | 杰克科技股份有限公司 | Sewing machine, thread cutting apparatus thereof, and thread cutting control method |
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Address after: 318010 No. 1008, east section of Donghai Avenue, Sanjia, Jiaojiang District, Taizhou City, Zhejiang Province Patentee after: Jack Technology Co.,Ltd. Address before: 318010 No. 1008, east section of Donghai Avenue, Sanjia, Jiaojiang District, Taizhou City, Zhejiang Province Patentee before: JACK SEWING MACHINE Co.,Ltd. |