Sewing machine and feeding and thread trimming integrated driving mechanism thereof

Abstract

The utility model provides a sewing machine and feeding trimming integrated drive mechanism, including drive motor, feed arm and trimming arm that rotate under the drive of drive motor, and trimming drive piece, feed arm is connected with feed mechanism, the trimming arm is provided with trimming ball, the trimming drive piece is provided with trimming drive arm; when the feeding teeth are about to come out of the needle plate, the included angle between the axis of the feeding arm and the axis of the feeding connecting rod is smaller than or equal to 25 degrees. And when the movable cutter and the fixed cutter are about to be engaged, the thread trimming ball is in contact fit with the thread trimming engagement surface. The utility model further provides a sewing machine which comprises the feeding and thread trimming integrated driving mechanism. The utility model has the beneficial effect that the peak load torque acting on the motor in the feeding and trimming process can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of sewing machines, in particular to a sewing machine and a feeding and thread-cutting integrated driving mechanism thereof. Background Art

[0002] In the design of sewing machines, due to many considerations such as streamlining the transmission structure, optimizing the installation space, and reducing production costs, the "one-to-two" technology of using one motor to drive feeding and thread cutting has gradually been applied. However, in actual operation, since the motor needs to cope with different execution conditions at the same time, how to reasonably match the relationship between motor performance and multi-condition loads is a more difficult technical problem. Increasing the motor power to cover different usage scenarios under multiple conditions is a common practice at present, but it will cause excess motor performance and increase production costs. Utility Model Content

[0003] The utility model aims to provide a feeding and thread trimming integrated driving mechanism, which can reduce the peak load torque acting on the motor during the feeding and thread trimming processes.

[0004] The utility model provides a feeding and thread-cutting integrated driving mechanism, which is arranged in a sewing machine. The sewing machine comprises a thread-cutting mechanism, a tooth frame, a feeding tooth fixed on the tooth frame, a feeding mechanism connected to a first end of the tooth frame, and a needle plate allowing the feeding tooth to emerge. The thread-cutting mechanism comprises a thread-cutting shaft rotatably arranged in the sewing machine, a movable knife drivingly connected to the thread-cutting shaft, and a fixed knife fixed in position. The feeding and thread-cutting integrated driving mechanism comprises a driving motor, a feeding arm and a thread-cutting arm rotating under the drive of the driving motor, and a thread-cutting driving member arranged on the thread-cutting shaft. An angle is formed between the extending direction of the feeding arm and the extending direction of the thread-cutting arm. The feeding arm is connected to the feeding mechanism through a feeding connecting rod. A rotatable thread-cutting ball is arranged on the thread-cutting arm. A thread-cutting driving member is provided on the thread-cutting driving member. There is a thread trimmer driving arm, on which a thread trimmer slide groove surface for contacting and cooperating with the thread trimmer ball is provided, and the thread trimmer slide groove surface includes a thread trimmer occlusal surface arranged at the end of the thread trimmer driving arm; the output shaft rotation angle of the driving motor has a feeding area and a thread trimming area that are independent of each other, and when the output shaft operates in the feeding area, the thread trimmer ball is separated from the thread trimmer driving arm, and the feeding arm drives the feeding tooth to reciprocate back and forth; when the feeding tooth is about to emerge from the needle plate, the angle between the axis of the feeding arm and the axis of the feeding connecting rod is less than or equal to 25°; when the output shaft operates in the thread trimming area, the thread trimmer ball contacts and cooperates with the thread trimmer slide groove surface to drive the movable knife to approach or move away from the fixed knife; when the movable knife and the fixed knife are about to end their engagement, the thread trimmer ball contacts and cooperates with the thread trimmer occlusal surface.

[0005] Preferably, one end of the thread cutting shaft is provided with a thread cutting crank, the thread cutting crank is hinged to the first end of the thread cutting connecting rod, the second end of the thread cutting connecting rod is hinged to the moving tool holder, and the moving tool is fixed on the moving tool holder.

[0006] Preferably, the feeding mechanism includes a feeding shaft rotatably arranged in the sewing machine and a tooth rest seat fixed to the first end of the feeding shaft, and the tooth rest seat is hinged to the first end of the tooth rest.

[0007] Preferably, the feeding arm is hinged to the first end of the feeding connecting rod, the second end of the feeding connecting rod is hinged to the first end of the feeding crank, and the second end of the feeding crank is hinged to the second end of the feeding shaft.

[0008] Preferably, the output shaft rotation angle of the driving motor further has a transition area distributed between the feeding area and the thread cutting area.

[0009] Preferably, the driving motor is a single-output shaft motor or a double-output shaft motor at both ends.

[0010] Preferably, the driving motor is a single-output shaft motor, the feeding arm and the thread cutting arm are connected to form a driving crank, and the driving crank is arranged on the output shaft of the driving motor.

[0011] Preferably, the feeding and thread cutting integrated driving mechanism is arranged below the needle plate.

[0012] The present utility model also provides a sewing machine, including the aforementioned feeding and thread cutting integrated driving mechanism.

[0013] Preferably, it further includes a tooth lifting mechanism, and the tooth lifting mechanism includes a tooth lifting shaft rotatably arranged in the sewing machine, a tooth lifting fork-shaped crank fixed to one end of the tooth lifting shaft, and a tooth lifting slider slidably assembled in the opening of the tooth lifting fork-shaped crank, and the tooth lifting slider is hinged to the second end of the tooth rest.

[0014] The beneficial effects of the present utility model are as follows:

[0015] 1. The functions of feeding and thread cutting are realized by driving with one driving motor, with integrated functions and a compact structure;

[0016] 2. By optimizing the feeding driving structure, the driving motor has a smaller load torque during the process of realizing electronic feeding;

[0017] 3. By optimizing the thread cutting driving structure, the driving motor has a smaller load torque during the process of realizing step-by-step thread cutting;

[0018] 4. Through structural optimization, the load distribution of the drive motor in the entire working area is more reasonable, the working performance is better, and the drive motor can be prevented from overheating, thereby extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a perspective view of the feeding and thread-cutting integrated drive mechanism of the present utility model;

[0020] Figure 2 is a force analysis diagram of the feed dog during the feeding process;

[0021] Figure 3 is a schematic diagram of the frictional force and inertial force received by the feed dog within one feeding cycle;

[0022] Figure 4 is a force analysis diagram of the thread-cutting mechanism during the thread-cutting process;

[0023] Figure 5 is a schematic diagram of the working range of the drive motor;

[0024] Figure 6 is a schematic diagram of the relative position of the feed link and the feed arm at the maximum feed load moment t1;

[0025] Figure 7 is a structural diagram of the thread-cutting driving member;

[0026] Figure 8 is a schematic diagram of the relative position of the thread-cutting ball and the thread-cutting driving member at the maximum thread-cutting load moment t2.

[0027] Description of Component Labels:

[0028] 1 Drive motor

[0029] 11 Thread-cutting area

[0030] 12 Transition area

[0031] 13 Feeding area

[0032] 2 Drive crank

[0033] 21 Feed arm

[0034] 22 Thread-cutting arm

[0035] 31 Feed link

[0036] 32 Feed crank

[0037] 4 Feed shaft

[0038] 41 Tooth rest seat

[0039] 51 Thread-cutting ball

[0040] 52 Thread cutting drive

[0041] 521 Thread cutting drive arm

[0042] 521a Thread cutting chute surface

[0043] 521b Thread cutting engaging surface

[0044] 6 Thread cutting shaft

[0045] 61 Thread cutting crank

[0046] 62 Thread cutting connecting rod

[0047] 63 Return spring

[0048] 71 Moving knife

[0049] 711 Moving knife holder

[0050] 72 Fixed knife

[0051] 8 Tooth carrier

[0052] 81 Feed tooth

[0053] 9 Tooth lifting mechanism

[0054] 100 Needle plate

[0055] 200 Sewing material

[0056] 300 Presser foot

[0057] 400 Spring Detailed implementation manners

[0058] The following further describes in detail the detailed implementation manners of the present utility model in conjunction with the accompanying drawings. These implementation manners are only used to illustrate the present utility model and are not intended to limit the present utility model.

[0059] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0060] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0061] Figure 1 The following description is based on the perspective of the three-dimensional view of the integrated driving mechanism for feeding and thread cutting of the present utility model. In the following description, the attached drawings in Figure 1 are used as the reference basis for directions. In Figure 1 it is defined that the length direction of the feeding shaft 4 is the left-right direction, and the driving motor 1 is located on the right side of the tooth carrier 8; the setting direction of the tooth carrier 8 is the front-back direction, and the tooth carrier base 41 is located on the front side of the lifting tooth mechanism 9; the direction perpendicular to the left-right direction and the front-back direction is the up-down direction.

[0062] The present utility model provides an integrated driving mechanism for feeding and thread cutting and a sewing machine including the integrated driving mechanism for feeding and thread cutting.

[0063] As shown in Figure 1 and Figure 2 the sewing machine includes a thread cutting mechanism, a tooth carrier 8, a feeding tooth 81 fixed on the tooth carrier 8, a feeding mechanism connected to the front end (i.e., the first end) of the tooth carrier 8, a lifting tooth mechanism 9 connected to the rear end (i.e., the second end) of the tooth carrier 8, and a needle plate 100 allowing the feeding tooth 81 to protrude.

[0064] Among them, a sewing material 200 is placed on the needle plate 100; the feeding mechanism includes a feeding shaft 4 rotatably arranged in the sewing machine and a tooth carrier base 41 fixed to the left end of the feeding shaft 4, and the tooth carrier base 41 is hinged to the front end of the tooth carrier 8; the lifting tooth mechanism 9 includes a lifting tooth shaft rotatably arranged in the sewing machine, a lifting tooth fork-shaped crank fixed to the left end of the lifting tooth shaft, and a lifting tooth slider slidably assembled in the opening of the lifting tooth fork-shaped crank, and the lifting tooth slider is hinged to the rear end of the tooth carrier 8, and the lifting tooth shaft extends in the left-right direction. When the sewing machine works, the feeding shaft 4 and the lifting tooth shaft rotate, the feeding mechanism drives the tooth carrier 8 and the feeding tooth 81 to perform reciprocating motion in the front-back direction, and the lifting tooth mechanism 9 drives the tooth carrier 8 and the feeding tooth 81 to perform reciprocating motion in the up-down direction. Finally, the feeding tooth 81 performs a compound motion with a trajectory similar to an ellipse as shown in Figure 3 to drive the sewing material 200 to move forward and complete the feeding action.

[0065] As shown in Figure 2 and Figure 3As shown, during the process of the feed dog 81 transporting the sewing material 200 (by default, there is no relative movement between the feed dog 81 and the sewing material 200), the feed dog 81 protrudes from the upper surface of the needle plate 100. The presser foot 300 presses the sewing material 200 under the action of the spring 400 and generates a downward normal force F on the feed dog 81. N (F N The numerical change caused by the change in tooth height is very small, and the numerical change amount ≤ 5%). Due to the normal force F N existing, the feed dog 81 is subjected to a frictional force f in the direction opposite to its feeding direction, and the value of the frictional force f is basically constant during the stable feeding process. At the same time, due to the high-speed operation of the machine, the feeding execution components such as the tooth holder 8 and the feed dog 81 are also subjected to their own inertial force F m in the front-back direction in addition to the frictional force f. When the feed dog 81 is about to sink into the needle plate 100 or about to protrude from the upper surface of the needle plate 100, the speed of the feed dog 81 is the smallest and the acceleration is the largest. Therefore, the inertial force F m has a maximum value at the two extreme points in the front-back direction of the movement trajectory of the feed dog. When the feed dog 81 operates in the first quadrant (i.e., during the process of the feed dog 81 protruding from the needle plate 100 to reaching the highest point), the directions of f and F m are the same, and the overall load of the feeding execution component is f + F m ; when the feed dog 81 operates in the second quadrant (i.e., during the process of the feed dog 81 descending from the highest point to sinking into the needle plate 100), the directions of f and F m are opposite, and the overall load of the feeding execution component is f - F m . It can be judged from this that within one feeding cycle, the moment t1 of the maximum feeding load is the moment when the feed dog 81 is about to protrude from the upper surface of the needle plate 100, and at this time, the load of the feeding execution component is f + F m .

[0066] Such as Figure 1As shown, the thread trimming mechanism includes a thread trimming shaft 6 rotatably arranged in the sewing machine, a return spring 63 sleeved on the thread trimming shaft 6, a movable knife 71 connected to the thread trimming shaft 6, and a fixed knife 72. Specifically, the thread trimming shaft 6 extends in the left and right directions, and a thread trimming crank 61 is provided at its left end. The thread trimming crank 61 is hinged to the first end of the thread trimming connecting rod 62, and the second end of the thread trimming connecting rod 62 is hinged to the movable knife frame 711, and the movable knife 71 is fixed on the movable knife frame 711. The movable knife 71 is arc-shaped, and a thread trimming bulge is provided on its outer arc surface. A through hole is provided in the thread trimming bulge, and the edge where the through hole intersects with the surface of the thread trimming bulge constitutes the thread trimming edge of the movable knife. The front end of the fixed knife 72 is provided with a straight fixed knife thread trimming edge. One end of the return spring 63 is fixed in the sewing machine, and the other end is connected to the thread trimming crank 61. When the thread trimming shaft 6 rotates, the movable knife 71 can be driven to rotate toward the fixed knife 72 and inserted under the fixed knife 72, so that the thread cutting edge of the movable knife and the thread cutting edge of the fixed knife are engaged with each other to complete the thread trimming action. After the thread trimming is completed, the return spring 63 drives the thread trimming shaft 6 to rotate and reset, and when the thread trimming is not needed, the return spring 63 also keeps the thread trimming shaft 6 in its initial position.

[0067] like Figure 4 As shown, during the thread trimming operation of the thread trimming mechanism, the thread trimming crank 61 is subjected to a load torque M generated by the return spring 63. S , M S The size of increases with the swing angle of the thread trimmer crank 61. Before the movable knife 71 and the fixed knife 72 enter the bite stage, the two are separated from each other and there is no interaction force; when the movable knife 71 and the fixed knife 72 bite each other, the movable knife holder 711 is subjected to a load torque M D , load torque M D The sources of M include the extrusion friction between the moving knife 71 and the fixed knife 72, the shear resistance of the suture fibers, etc. Therefore, during the thread trimming process, the maximum thread trimming load moment t2 is the moment when the moving knife 71 and the fixed knife 72 are about to end the bite. S and M D Both have maximum values, and the combined load torque generated by the two is recorded as M SD .

[0068] In order to reduce the peak load torque acting on the motor during feeding and wire cutting, the load distribution of the motor in the whole working area is more reasonable, such as Figure 1As shown in the figure, the integrated driving mechanism for feeding and thread cutting provided by the present utility model includes a driving motor 1, a feeding arm 21 and a thread cutting arm 22 that rotate under the drive of the driving motor 1, and a thread cutting driving member 52 arranged on a thread cutting shaft 6. The integrated driving mechanism for feeding and thread cutting is arranged below a needle plate 100. Among them, there is an included angle between the extending direction of the feeding arm 21 and the extending direction of the thread cutting arm 22, and the specific angle value of this included angle can be set according to working requirements. The feeding arm 21 is connected to a feeding mechanism through a feeding connecting rod 31, and a rotatable thread cutting ball 51 is provided on the thread cutting arm 22. Specifically, the feeding arm 21 is hinged to the first end of the feeding connecting rod 31, the second end of the feeding connecting rod 31 is hinged to the first end of a feeding crank 32, and the second end of the feeding crank 32 is hinged to the right end (i.e., the second end) of a feeding shaft 4. As Figure 7 shown, the thread cutting driving member 52 is provided with an extended thread cutting driving arm 521, and an outer peripheral surface of the thread cutting driving arm 521 has a thread cutting chute surface 521a for contact and cooperation with the thread cutting ball 51, and the thread cutting chute surface 521a includes a thread cutting engaging surface 521b arranged at an end of the thread cutting driving arm 521.

[0069] As Figure 5 shown, the output shaft rotation angle of the driving motor 1 has a feeding area 13 and a thread cutting area 11 that are independent of each other. The two ends of the thread cutting area 11 have angles A1 and A2 respectively, and the two ends of the feeding area 13 have angles A3 and A4 respectively. Along the forward rotation direction of the driving motor 1, A1 < A2 < A3 < A4. That is, the angle range of the thread cutting area 11 is A1 to A2, and the angle range of the feeding area 13 is A3 to A4. At the same time, the output shaft rotation angle of the driving motor 1 also has a transition area 12 distributed between the feeding area 13 and the thread cutting area 11, and the angle range of the transition area 12 is A2 to A3.

[0070] When the sewing machine is sewing normally, the output shaft of the driving motor 1 operates within the feeding area 13, and the thread cutting ball 51 is separated from the thread cutting driving arm 521 and does not transmit power. Therefore, the thread cutting mechanism does not perform a thread cutting action. The feeding arm 21 drives a feed dog 81 to perform a reciprocating forward and backward movement through the feeding connecting rod 31 and the feeding mechanism, and the feed dog 81 feeds normally. As Figure 6 shown, when the feed dog 81 is about to emerge from the needle plate 100, the included angle θ between the axis of the feeding arm 21 and the axis of the feeding connecting rod 31 is less than or equal to 25°. The smaller included angle θ makes the acting force F1 of the feeding connecting rod 31 on the feeding arm 21 have a shorter force arm L1 (L1 ≤ 15 mm), thereby reducing the peak load torque M1 of the driving motor 1.

[0071] When thread cutting is required, the output shaft of the driving motor 1 reversely rotates from the current angle of the feeding area 13 to the starting angle A2 of the thread cutting area 11, and then continuously reversely rotates within the thread cutting area 11 to the end angle A1 of the thread cutting area 11. As Figure 7 and Figure 8As shown, during the process of the output shaft rotating from A2 to A1, the wire-cutting ball 51 is in contact and cooperation with the wire-cutting chute surface 521a. The wire-cutting arm 22 pushes the wire-cutting driving member 52 to drive the wire-cutting shaft 6 to rotate, and then drives the moving knife 71 to move through the wire-cutting crank 61, the wire-cutting connecting rod 62, and the moving knife holder 711, so that the moving knife 71 gradually approaches the fixed knife 72 and inserts below the fixed knife 72. When the moving knife 71 and the fixed knife 72 are about to finish engaging, the wire-cutting ball 51 is in contact and cooperation with the wire-cutting engaging surface 521b. The wire-cutting engaging surface 521b has a specific angle, so that the acting force F2 of the wire-cutting driving member 52 on the wire-cutting arm 22 has a shorter force arm L2 (L2 ≤ 15 mm), thereby reducing the peak load torque M2 of the driving motor 1. When the output shaft of the driving motor 1 rotates within the wire-cutting area 11, the feeding arm 21 and the feeding connecting rod 31 are collinear, and the feeding crank 32 basically remains stationary. Therefore, the displacement of the feeding tooth 81 in the front-back direction is very small, and the feeding action is not performed. After the wire cutting is completed, the output shaft of the driving motor 1 rotates forward to the current angle within the feeding area 13 before wire cutting. Under the action of the return spring 63, the wire-cutting shaft 6 and the wire-cutting driving member 52 rotate and reset, driving components such as the wire-cutting crank 61, the wire-cutting connecting rod 62, the moving knife holder 711, and the moving knife 71 to reset respectively.

[0072] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present invention, several improvements and replacements can be made, and these improvements and replacements should also be regarded as the protection scope of the present invention.

Claims

1. A feeding and thread trimming integrated drive mechanism, arranged in a sewing machine, the sewing machine comprising a thread trimming mechanism, a tooth frame, a feed tooth fixed on the tooth frame, a feeding mechanism connected to a first end of the tooth frame, and a needle plate allowing the feed tooth to emerge, the thread trimming mechanism comprising a thread trimming shaft rotatably arranged in the sewing machine, a moving knife drivingly connected to the thread trimming shaft, and a fixed knife in a fixed position, characterized in that: The feeding and thread-cutting integrated driving mechanism comprises a driving motor, a feeding arm and a thread-cutting arm which rotate under the drive of the driving motor, and a thread-cutting driving member arranged on the thread-cutting shaft, wherein an angle is formed between the extending direction of the feeding arm and the extending direction of the thread-cutting arm, the feeding arm is connected to the feeding mechanism through a feeding connecting rod, a rotatable thread-cutting ball is arranged on the thread-cutting arm, the thread-cutting driving member is provided with a thread-cutting driving arm, the thread-cutting driving arm is provided with a thread-cutting slide groove surface for contacting and cooperating with the thread-cutting ball, and the thread-cutting slide groove surface comprises a thread-cutting bite surface arranged at the end of the thread-cutting driving arm; The output shaft rotation angle of the driving motor has a feeding area and a thread cutting area which are independent of each other. When the output shaft operates in the feeding area, the thread trimming ball is separated from the thread trimming driving arm, and the feeding arm drives the feeding dog to reciprocate forward and backward; when the feeding dog is about to emerge from the needle plate, the angle between the axis of the feeding arm and the axis of the feeding connecting rod is less than or equal to 25°; When the output shaft rotates in the thread trimming area, the thread trimming ball contacts and cooperates with the thread trimming groove surface to drive the movable knife to approach or move away from the fixed knife; when the movable knife and the fixed knife are about to end the bite, the thread trimming ball contacts and cooperates with the thread trimming bite surface.

2. The feeding and thread trimming integrated drive mechanism according to claim 1 is characterized in that: A thread trimmer crank is provided at one end of the thread trimmer shaft. The thread trimmer crank is hinged to the first end of the thread trimmer connecting rod. The second end of the thread trimmer connecting rod is hinged to the moving knife frame. The moving knife is fixed on the moving knife frame.

3. The feeding and thread trimming integrated drive mechanism according to claim 1 is characterized in that: The feeding mechanism comprises a feeding shaft rotatably arranged in the sewing machine and a tooth frame seat fixed to the first end of the feeding shaft, and the tooth frame seat is hinged to the first end of the tooth frame.

4. The feeding and thread trimming integrated drive mechanism according to claim 3 is characterized in that: The feeding arm is hinged to the first end of the feeding connecting rod, the second end of the feeding connecting rod is hinged to the first end of the feeding crank, and the second end of the feeding crank is hinged to the second end of the feeding shaft.

5. The feeding and thread trimming integrated drive mechanism according to claim 1, characterized in that: The output shaft rotation angle of the driving motor also has a transition zone distributed between the feeding zone and the thread cutting zone.

6. The feeding and thread trimming integrated drive mechanism according to claim 1, characterized in that: The driving motor is a single-shaft motor or a double-shaft motor at both ends.

7. The feeding and thread trimming integrated drive mechanism according to claim 6, characterized in that: The driving motor is a single-shaft motor. The feeding arm and the thread trimming arm are connected to each other to form a driving crank. The driving crank is arranged on the output shaft of the driving motor.

8. The feeding and thread trimming integrated drive mechanism according to claim 1, characterized in that: The feeding and thread trimming integrated driving mechanism is arranged below the needle plate.

9. A sewing machine, characterized in that: It comprises the feeding and thread cutting integrated drive mechanism as described in any one of claims 1-8.

10. The sewing machine according to claim 9, characterized in that It also includes a tooth lifting mechanism, which includes a tooth lifting shaft rotatably arranged in the sewing machine, a tooth lifting fork crank fixed at one end of the tooth lifting shaft, and a tooth lifting slider slidably assembled in the opening of the tooth lifting fork crank, and the tooth lifting slider is hinged to the second end of the tooth frame.

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