CN209836493U - Driving device for trimming and lifting presser foot on sewing machine - Google Patents

Abstract

The utility model provides a last drive arrangement who is used for trimming and lifts presser foot of sewing machine belongs to clothing manufacturing equipment technical field. The thread trimming and presser foot lifting driving device solves the technical problems of poor sensitivity, low efficiency and the like of the thread trimming and presser foot lifting driving device of the existing sewing machine. The sewing machine comprises a machine shell, a machine base, a presser bar, a presser foot and a thread trimming mechanism, the driving device comprises a presser foot lifting shaft, a thread trimming shaft and a driving motor, a thread trimming cam and a presser foot lifting cam are fixedly arranged on an output shaft of the driving motor respectively, the thread trimming cam and the presser foot lifting cam are provided with convex parts, and the convex parts of the thread trimming cam and the presser foot lifting cam are arranged in a staggered manner; the thread trimming cam can drive the thread trimming shaft to move axially through the thread trimming crank, and the end part of the thread trimming shaft is connected with the thread trimming mechanism; the pressure foot lifting cam can drive the pressure foot lifting shaft to rotate through the pressure foot lifting swing rod, and the end part of the pressure foot lifting shaft is connected with the pressure foot rod. The utility model provides a drive arrangement is sensitive high-efficient, and is accurate reliable.

Description

Driving device for trimming and lifting presser foot on sewing machine

Technical Field

The utility model belongs to the technical field of garment manufacturing equipment, a sewing machine is related to, especially a sewing machine is last to be used for the trimming and to lift the drive arrangement of presser foot.

Background

A sewing machine is a machine that uses one or more sewing threads to form one or more stitches in a material to be sewn, thereby interweaving or stitching one or more layers of material. The sewing machine can sew fabrics such as cotton, hemp, silk, wool, artificial fiber and the like and products such as leather, plastic, paper and the like, and the sewed stitches are neat, beautiful, flat and firm, the sewing speed is high, and the use is simple and convenient. The sewing machine is generally composed of four parts, namely a feeding device, a machine base, a transmission part and an accessory part, and sewing materials are sewn through reasonable cooperation and circular work of the movement of each mechanism. The sewing machine can use the functions of automatic thread trimming and automatic presser foot lifting in the sewing process; the sewing machine on the existing market generally uses two electromagnets with different powers to drive the thread trimming and lift the presser foot function respectively, the driving mode structure is complex, the transmission efficiency is low, the electromagnets can generate collision noise, the long-time electrification is easy to generate heat, and the failure rate is high.

Chinese patent (publication No. CN207031720U, published as 2018-02-23) discloses a single thread and pressure foot lifting drive device for sewing machine thread trimming, which comprises a stepping motor, a first main shaft connected with the thread and pressure foot lifting device, a thread trimming device and a second main shaft connected with the thread trimming device, wherein the first main shaft is connected with the thread and pressure foot lifting device through a linkage rod assembly, and an output shaft of the stepping motor is provided with a crank mechanism of the thread and pressure foot lifting device connected with the first main shaft and a crank mechanism of the thread and pressure foot lifting device connected with the second main shaft. The presser foot lifting device crank mechanism comprises a first cam and a first crank, one end of the first crank is fixed on the first main shaft, and the other end of the first crank is rotationally connected with the first cam; the wire shearing device crank mechanism comprises a second cam and a second crank, one end of the second crank is fixed on the second main shaft, and the other end of the second crank is connected with the second cam in a sliding manner; the second cam is provided with a sliding block, and the second crank is provided with a sliding groove in sliding fit with the sliding block. The linkage rod assembly comprises a pull rod arranged above the first main shaft and a top rod respectively connected with the pull rod and the first main shaft; the first main shaft is provided with a third crank for driving the ejector rod to lift, and the third crank is provided with a transverse through hole for mounting the first main shaft and a connecting part for driving the ejector rod to lift.

In the patent documents, a stepping motor is used as a driving source to realize the functions of trimming and lifting the presser foot, but the trimming mechanism is not suitable for long-distance transmission, the structure adaptability is poor, and the cam structure is not flexible and rapid to control, so that the efficiency is low.

Disclosure of Invention

The utility model discloses to the above-mentioned problem that prior art exists, provide a last drive arrangement who is used for the trimming and lifts the presser foot of sewing machine, the utility model aims to solve the technical problem be: the control sensitivity and the efficiency of the drive of the thread trimming and presser foot lifting of the sewing machine are improved.

The purpose of the utility model can be realized by the following technical proposal:

a sewing machine is used for shearing thread and lifting the drive arrangement of the presser foot, the sewing machine includes the body case, bed plate, presser foot bar set up on the said body case and set up in the presser foot of the lower end of the said presser foot bar, the position that is located under the said presser foot on the said bed plate also has thread trimming mechanisms, characterized by that, the said drive arrangement includes lifting the presser foot axle, thread trimming axle and driving motor that can be turned forward and backward, the said driving motor is set firmly on the said body case, set firmly thread trimming cam and lifting the presser foot cam on the output shaft of the said driving motor respectively, the said thread trimming cam and lifting the presser foot cam are equipped with the bulge, the said thread trimming cam and lifting the bulge of the presser foot cam are staggered to set up; the thread trimming cam can drive the thread trimming shaft to move axially through the thread trimming crank, and the end part of the thread trimming shaft is connected with the thread trimming mechanism through the swing rod and can drive the thread trimming mechanism to do shearing movement; the pressure foot lifting cam can drive the pressure foot lifting shaft to rotate through a pressure foot lifting swing rod, and the end part of the pressure foot lifting shaft is connected with the pressure foot rod through a connecting plate and can drive the pressure foot rod to move up and down.

The principle is as follows: when the thread cutting is needed after the sewing is finished, the driving motor receives a thread cutting signal of the main controller, an output shaft of the driving motor rotates to drive the thread cutting cam to rotate, the thread cutting cam drives the thread cutting shaft to move axially through the thread cutting crank, and the thread cutting shaft drives the swing rod to swing so as to drive the movable cutter to finish the cutter discharging action; the driving motor continues to move, the thread trimming mechanism resets to finish thread trimming and clamp a bottom thread, then, the protruding part of the presser foot lifting cam on the output shaft of the driving motor drives the presser foot lifting swing rod to move, the presser foot lifting shaft is driven to rotate, and the presser foot lifting shaft drives the presser foot rod and the presser foot on the presser foot rod to move through the connecting plate, so that the presser foot lifting action is realized. When the presser foot needs to be lifted midway in the thread trimming process, the driving motor rotates reversely to drive the presser foot lifting cam to rotate, the protruding part of the presser foot lifting cam drives the presser foot lifting swing rod to move, the presser foot lifting shaft is further driven to rotate, the presser foot lifting shaft drives the presser foot rod and the presser foot on the presser foot rod to move through the connecting plate, the presser foot lifting action is realized, and then the presser foot is rotated forwardly and returned.

In the technical scheme, the forward rotation and the reverse rotation of the driving motor are opposite, and the rotating direction of the driving motor can be adjusted or changed by adjusting the angles of the thread trimming cam and the presser foot lifting cam. As an equivalent alternative, it is not described herein in detail.

Adopt driving motor drive trimming mechanism and presser foot among this technical scheme, replace the electro-magnet and reduced the driving source, the drive mode of trimming cam and lift presser foot cam adopts the contact to connect, and the noise is little, and the profile drive stroke through the cam is more accurate reliable, and the drive mechanism design is the subassembly module, assembles simply.

According to the technical scheme, the action stroke is enlarged through the plurality of link mechanisms, the requirements of the thread trimming action and the presser foot lifting action can be met only by driving the motor to do small-amplitude action, meanwhile, the thread trimming cam and the presser foot lifting cam are both provided with the two symmetrically arranged convex parts, the presser foot is lifted when the thread trimming returns, and the integral time of the presser foot lifting action after thread trimming is shortened; therefore, the driving motor can drive the thread cutting action and the presser foot lifting action in a positive and negative rotation mode, and the thread cutting action and the presser foot lifting action are more sensitive and efficient.

According to the technical scheme, the lifting height of the presser foot can be set through the operation panel on the main electronic control unit, and the set parameters can correspond to the rotating angle of the driving motor, so that the function of adjusting the height of the presser foot is realized.

According to the technical scheme, the connecting rod structure for trimming the wire and the connecting rod assembly for lifting the presser foot are wide in applicability, and applicable to long-distance transmission of the driving motor, the position of the driving motor can be randomly arranged, and the wire trimming and the presser foot lifting action can be completed by long-distance power transmission. In addition, the inertia of the thread trimming cam and the presser foot lifting cam is small, the reversing is flexible, the rotating reversing delay of the driving motor is lower, the thread trimming cam and the presser foot lifting cam cannot be jammed, the seam breakage rate can be reduced, and the vibration noise of the presser foot lifting is reduced.

In the driving device for trimming and lifting the presser foot on the sewing machine, a mounting seat is fixedly arranged on the machine shell, and the driving motor is fixed on the mounting seat through a connecting bolt; the thread cutting shaft is hinged to the mounting seat, and the pressure lifting and pressing shaft is rotatably arranged on the machine shell.

In the driving device for trimming and lifting the presser foot on the sewing machine, the driving motor is a stepping motor; the thread cutting shaft and the presser foot lifting shaft are arranged in parallel at intervals; the included angle of the long axes of the thread trimming cam and the presser foot lifting cam is 30-60 degrees. The thread trimming cam and the presser foot lifting cam in the technical scheme can be in an oval shape and can be fixedly arranged on the output shaft of the driving motor at intervals, and the long axis in the technical scheme is a connecting line between the outermost ends of two convex parts of the thread trimming cam and the presser foot lifting cam. By adjusting the included angle of the long axes of the thread trimming cam and the presser foot lifting cam, the minimum time interval between the thread trimming action and the presser foot lifting action can be preset, so that the high-efficiency requirement is met.

In the driving device for trimming and lifting the presser foot on the sewing machine, a presser foot lifting wrench is hinged on the machine shell, one end of the presser foot lifting wrench is provided with a wrenching part, the upper end of the presser foot lifting swing rod is fixedly connected to the other end of the presser foot lifting wrench, the lower end of the presser foot lifting swing rod extends downwards, and the side part of the presser foot lifting swing rod can abut against the presser foot lifting cam; the pressure foot lifting shaft is fixedly provided with a pressure foot lifting crank, the outer end of the pressure foot lifting crank is hinged with a connecting arm, and the connecting arm is connected with the pressure foot lifting wrench through a wrench shaft and a wrench crank.

In the driving device for trimming and lifting the presser foot on the sewing machine, the presser foot rod is fixedly provided with a lifting block, the end part of the presser foot lifting shaft is fixedly provided with a connecting plate crank, one end of the connecting plate is hinged with the outer end of the connecting plate crank, the other end of the connecting plate is provided with a strip-shaped hole along the length direction of the connecting plate, and the lifting block is fixedly provided with a shaft position screw inserted in the strip-shaped hole; and a presser foot reset shaft spring is sleeved on the presser foot lifting shaft.

In the driving device for trimming and lifting the presser foot on the sewing machine, the trimming crank is fixedly arranged on the trimming shaft, the mounting seat is provided with the swinging connecting rod, the upper end of the swinging connecting rod is hinged on the mounting seat, and the lower end of the swinging connecting rod is movably connected with the trimming crank through the connecting short plate.

In the driving device for trimming and lifting the presser foot on the sewing machine, the mounting seat is provided with two mounting plates which are arranged in parallel at intervals near the lower end, the trimming spool is arranged on the two mounting plates in a sliding manner, the trimming crank is positioned between the two mounting plates, the trimming spool is further sleeved with a trimming reset shaft spring, and two ends of the trimming reset shaft spring respectively act on the trimming crank and one of the mounting plates.

In the driving device for trimming and lifting the presser foot on the sewing machine, the middle part of the swing rod is hinged on the base, the end part of the trimming shaft is connected with the pulling plate through the connecting column, the pulling plate is hinged with one end of the swing rod, and the other end of the swing rod is connected with the trimming mechanism.

In the driving device for trimming and lifting the presser foot on the sewing machine, the trimming mechanism comprises an upper knife rest, a movable knife fixedly arranged at the end part of the upper knife rest, a lower knife rest and a fixed knife fixedly arranged at the end part of the lower knife rest; the upper tool rest is movably arranged on the base, the lower tool rest is fixedly arranged on the base, a groove is formed in one side of the middle of the upper tool rest, and the end portion of the swing rod is inserted into the groove.

In the driving device for trimming and lifting the presser foot on the sewing machine, the trimming cam and the presser foot lifting cam are respectively provided with an idle stroke part, and an axisymmetric line of the idle stroke part on the trimming cam, an axisymmetric line of the convex part and one radial central line of an output shaft of the driving motor are collinear; the axial symmetry line of the idle stroke part on the pressure lifting and pressing foot cam, the axial symmetry line of the protruding part and one radial central line of the output shaft of the driving motor are collinear. The part between the idle stroke part and the bulge part on the trimming cam and the presser foot lifting cam can be arranged in other shapes.

Compared with the prior art, the utility model provides a mounting structure has following advantage:

1. the utility model provides a drive arrangement adopts driving motor drive trimming mechanism and presser foot, replaces the electro-magnet to have reduced the driving source, and the trimming cam adopts the contact to connect with the drive mode of lifting the presser foot cam, and the noise is little, and the profile drive stroke through the cam is more accurate reliable, and the drive mechanism design is the subassembly module, and the equipment is simple.

2. The driving device in the utility model enlarges the action stroke through a plurality of link mechanisms, only needs the driving motor to do small-amplitude action, can meet the requirements of the thread trimming action and the presser foot lifting action, simultaneously, because the thread trimming cam and the presser foot lifting cam are both provided with two symmetrically arranged convex parts, the presser foot is lifted when the thread trimming returns, and the whole time of the presser foot lifting action after thread trimming is shortened; therefore, the driving motor can drive the thread cutting action and the presser foot lifting action in a positive and negative rotation mode, and the thread cutting action and the presser foot lifting action are more sensitive and efficient.

3. The utility model provides a drive arrangement presser foot lifts up the height and can set up through the main automatically controlled operating panel that goes up, and the parameter of setting can correspond driving motor pivoted angle to the realization is lifted presser foot height-adjustable's function.

4. The utility model provides a drive arrangement connecting rod structure with lift link assembly extensive applicability of presser foot is general, applicable in driving motor long distance transmission, realizes that the driving motor position arranges wantonly, and remote transmission power is accomplished the trimming and is lifted the presser foot action. In addition, the inertia of the thread trimming cam and the presser foot lifting cam is small, the reversing is flexible, the rotating reversing delay of the driving motor is lower, the thread trimming cam and the presser foot lifting cam cannot be jammed, the seam breakage rate can be reduced, and the vibration noise of the presser foot lifting is reduced.

Drawings

Fig. 1 is a schematic view of the mounting structure of the present driving apparatus.

Fig. 2 is a partially enlarged schematic view of the driving device.

Fig. 3 is a schematic perspective view of the driving device.

Fig. 4 is a partially enlarged schematic view of a portion a in fig. 3.

In the figure, 1, a housing; 2. a machine base; 3. a presser bar; 4. a thread trimming mechanism; 41. an upper tool rest; 41a, a groove; 42. a lower tool rest; 43. moving a knife; 44. fixing a cutter; 5. a drive motor; 6. lifting the presser foot shaft; 7. a thread cutting shaft; 8. a trimming cam; 9. lifting a presser foot cam; 9a, an idle stroke part; 9b, a projection; 10. a thread cutting crank; 11. a swing rod; 12. lifting a presser foot swing lever; 13. a connecting plate; 13a, a strip-shaped hole; 14. a mounting seat; 14a, a mounting plate; 15. a connecting bolt; 16. lifting a pressure foot wrench; 16a, a pulling part; 17. lifting a presser foot crank; 18. a connecting arm; 19. a wrench shaft; 20. a wrench crank; 21. a lifting block; 22. a presser foot; 23. an axial screw; 24. a presser foot reset shaft spring; 25. a swing link; 26. a trimming reset shaft spring; 27. pulling a plate; 28. and connecting a plate crank.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

As shown in fig. 1 to 4, the sewing machine includes a machine shell 1, a machine base 2, a presser bar 3 arranged on the machine shell 1, and a presser foot 22 arranged at the lower end of the presser bar 3, wherein a thread trimming mechanism 4 is further arranged on the machine base 2 at a position right below the presser foot 22, the driving device includes a presser foot lifting shaft 6, a thread trimming shaft 7 and a driving motor 5 capable of rotating forward and backward, a mounting seat 14 is fixedly arranged on the machine shell 1, and the driving motor 5 is fixed on the mounting seat 14 through a connecting bolt 15; the thread cutting shaft 7 is rotatably arranged on the mounting seat 14, the presser foot lifting shaft 6 is rotatably arranged on the machine shell 1, the output shaft of the driving motor 5 is fixedly provided with a thread cutting cam 8 and a presser foot lifting cam 9 respectively, the thread cutting cam 8 and the presser foot lifting cam 9 are both provided with a convex part 9b and an idle stroke part 9a, and the axial symmetry line of the idle stroke part 9a on the thread cutting cam 8, the axial symmetry line of the convex part 9b and one radial center line of the output shaft of the driving motor 5 are collinear; the axial symmetry line of the idle stroke part 9a on the pressure raising and pressing foot cam 9, the axial symmetry line of the convex part 9b and one radial central line of the output shaft of the driving motor 5 are collinear. The thread trimming cam 8 and the bulge part 9b of the presser foot lifting cam 9 are arranged in a staggered manner, and the staggered angle of the thread trimming cam and the bulge part is an acute angle; the thread trimming cam 8 can drive the thread trimming shaft 7 to axially move through the thread trimming crank 10, and the end part of the thread trimming shaft 7 is connected with the thread trimming mechanism 4 through the swing rod 11 and can drive the thread trimming mechanism 4 to do shearing motion; the presser foot lifting cam 9 can drive the presser foot lifting shaft 6 to rotate through the presser foot lifting swing rod 12, and the end part of the presser foot lifting shaft 6 is connected with the presser foot rod 3 through the connecting plate 13 and can drive the presser foot rod 3 to move up and down. Further, a presser foot lifting wrench 16 is hinged to the machine shell 1, one end of the presser foot lifting wrench 16 is provided with a wrenching portion 16a, the upper end of the presser foot lifting swing rod 12 is fixedly connected to the other end of the presser foot lifting wrench 16, the lower end of the presser foot lifting swing rod 12 extends downwards, and the side portion of the presser foot lifting swing rod can abut against the presser foot lifting cam 9; a pressure lifting and foot crank 17 is fixedly arranged on the pressure lifting and foot shaft 6, the outer end of the pressure lifting and foot crank 17 is hinged with a connecting arm 18, and the connecting arm 18 is connected with a pressure lifting and foot wrench 16 through a wrench shaft 19 and a wrench crank 20; a lifting block 21 is fixedly arranged on the presser foot rod 3, a connecting plate crank 28 is fixedly arranged at the end part of the presser foot lifting shaft 6, one end of a connecting plate 13 is hinged with the outer end of the connecting plate crank 28, a strip-shaped hole 13a along the length direction of the connecting plate 13 is formed in the other end of the connecting plate 13, and a shaft position screw 23 inserted in the strip-shaped hole 13a is fixedly arranged on the lifting block 21; a presser foot reset shaft spring 24 is sleeved on the presser foot lifting shaft 6; the thread cutting crank 10 is fixedly arranged on the thread cutting shaft 7, the mounting seat 14 is provided with a swinging connecting rod 25, the upper end of the swinging connecting rod 25 is hinged on the mounting seat 14, and the lower end of the swinging connecting rod 25 is movably connected with the thread cutting crank 10 through a connecting short plate; the mounting seat 14 is provided with two mounting plates 14a which are arranged in parallel at intervals near the lower end, the thread cutting shaft 7 is arranged on the two mounting plates 14a in a sliding manner, the thread cutting crank 10 is positioned between the two mounting plates 14a, the thread cutting shaft 7 is further sleeved with a thread cutting reset shaft spring 26, and two ends of the thread cutting reset shaft spring 26 respectively act on the thread cutting crank 10 and one of the mounting plates 14 a; the middle part of the swing rod 11 is hinged on the base 2, the end part of the thread cutting shaft 7 is connected with a pulling plate 27 through a connecting column, the pulling plate 27 is hinged with one end of the swing rod 11, and the other end of the swing rod 11 is connected with the thread cutting mechanism 4. The thread cutting mechanism 4 comprises an upper cutter frame 41, a movable cutter 43 fixedly arranged at the end part of the upper cutter frame 41, a lower cutter frame 42 and a fixed cutter 44 fixedly arranged at the end part of the lower cutter frame 42; the upper tool rest 41 is movably arranged on the machine base 2, the lower tool rest 42 is fixedly arranged on the machine base 2, a groove 41a is formed in one side of the middle of the upper tool rest 41, and the end portion of the swing rod 11 is inserted into the groove 41 a.

When the thread cutting is needed after the sewing is finished, the driving motor 5 receives a thread cutting signal of the main controller, an output shaft of the driving motor 5 rotates to drive the thread cutting cam 8 to rotate, the thread cutting cam 8 drives the thread cutting shaft 7 to move axially through the thread cutting crank 10, and the thread cutting shaft 7 drives the swing rod 11 to swing so as to drive the thread cutting mechanism 4 to perform the thread cutting action; the driving motor 5 continues to move, the thread trimming mechanism 4 resets, then, the protruding part 9b of the presser foot lifting cam 9 on the output shaft of the driving motor 5 drives the presser foot lifting swing rod 12 to move, further drives the presser foot lifting shaft 6 to rotate, the presser foot lifting shaft 6 drives the presser foot rod 3 and the presser foot 22 on the presser foot rod 3 to move through the connecting plate 13, and the action of the presser foot 22 is realized. When the presser foot 22 needs to be lifted midway in the thread trimming process, the driving motor 5 rotates reversely to drive the presser foot lifting cam 9 to rotate, the protruding part 9b of the presser foot lifting cam 9 drives the presser foot lifting swing rod 12 to move, and further drives the presser foot lifting shaft 6 to rotate, the presser foot lifting shaft 6 drives the presser foot rod 3 and the presser foot 22 on the presser foot rod 3 to move through the connecting plate 13, the action of lifting the presser foot 22 is realized, and then the presser foot 22 rotates forwards and returns.

The driving device in the embodiment adopts the driving motor 5 to drive the trimming mechanism 4 and the presser foot 22, the electromagnet is replaced, the driving source is reduced, the trimming cam 8 and the presser foot lifting cam 9 are in contact connection in a driving mode, the noise is low, the driving stroke is more accurate and reliable through the contour of the cam, the driving mechanism is designed into an assembly module, and the assembly is simple.

The lifting height of the presser foot 22 of the driving device in the embodiment can be set through an operation panel on the main electronic control, and the set parameters can correspond to the rotating angle of the driving motor 5, so that the function of adjusting the height of the presser foot 22 is realized.

The connecting rod structure of the trimming and the connecting rod assembly of the presser foot lifting 22 in the driving device in the embodiment have wide applicability, and can be suitable for long-distance transmission of the driving motor 5, so that the position of the driving motor 5 can be randomly arranged, and the power can be transmitted in a long distance to finish the actions of trimming and the presser foot lifting 22. In addition, the inertia of the trimming cam 8 and the presser foot lifting cam 9 is small, the reversing is flexible, the rotating reversing delay of the driving motor 5 is lower, the trimming and presser foot lifting 22 cannot be blocked, the sewing and thread breakage rate can be reduced, and the vibration noise of the presser foot lifting 22 is reduced.

Further, the driving motor 5 in this embodiment is a stepping motor; the thread cutting shaft 7 and the presser foot lifting shaft 6 are arranged in parallel at intervals; as the preferred scheme, the included angle of the long axes of the trimming cam 8 and the presser foot lifting cam 9 is 30-60 degrees; preferably 45 in this embodiment. The trimming cam 8 and the presser foot lifting cam 9 may be elliptical, and both may be fixed on the output shaft of the driving motor 5 at intervals, and the long axis in this embodiment is the longest connecting line between the two outer ends of the trimming cam 8 and the presser foot lifting cam 9. By adjusting the included angle of the long axes of the trimming cam 8 and the presser foot lifting cam 9, the minimum time interval between the trimming action and the presser foot lifting action 22 can be preset, thereby meeting the requirement of high efficiency.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Although 1, a housing is used more herein; 2. a machine base; 3. a presser bar; 4. a thread trimming mechanism; 41. an upper tool rest; 41a, a groove; 42. a lower tool rest; 43. moving a knife; 44. fixing a cutter; 5. a drive motor; 6. lifting the presser foot shaft; 7. a thread cutting shaft; 8. a trimming cam; 9. lifting a presser foot cam; 9a, an idle stroke part; 9b, a projection; 10. a thread cutting crank; 11. a swing rod; 12. lifting a presser foot swing lever; 13. a connecting plate; 13a, a strip-shaped hole; 14. a mounting seat; 14a, a mounting plate; 15. a connecting bolt; 16. lifting a pressure foot wrench; 16a, a pulling part; 17. lifting a presser foot crank; 18. a connecting arm; 19. a wrench shaft; 20. a wrench crank; 21. a lifting block; 22. a presser foot; 23. an axial screw; 24. a presser foot reset shaft spring; 25. a swing link; 26. a trimming reset shaft spring; 27. pulling a plate; 28. web crank, etc., but does not exclude the possibility of using other terms. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed in a manner that is inconsistent with the spirit of the invention.

Claims (10)

1. A driving device for trimming and lifting a presser foot on a sewing machine, the sewing machine comprises a machine shell (1), a machine base (2), a presser foot rod (3) arranged on the machine shell (1) and a presser foot (22) arranged at the lower end of the presser foot rod (3), a thread trimming mechanism (4) is arranged on the machine base (2) and is positioned right below the presser foot (22), it is characterized in that the driving device comprises a pressure foot lifting shaft (6), a thread cutting shaft (7) and a driving motor (5) which can rotate forward and backward, the driving motor (5) is fixedly arranged on the shell (1), the output shaft of the driving motor (5) is respectively and fixedly provided with a thread cutting cam (8) and a presser foot lifting cam (9), the trimming cam (8) and the presser foot lifting cam (9) are both provided with a convex part (9b), the thread trimming cam (8) and the bulge part (9b) of the presser foot lifting cam (9) are arranged in a staggered manner; the thread trimming cam (8) can drive the thread trimming shaft (7) to axially move through a thread trimming crank (10), and the end part of the thread trimming shaft (7) is connected with the thread trimming mechanism (4) through a swing rod (11) and can drive the thread trimming mechanism (4) to perform shearing motion; the presser foot lifting cam (9) can drive the presser foot lifting shaft (6) to rotate through a presser foot lifting swing rod (12), and the end part of the presser foot lifting shaft (6) is connected with the presser foot rod (3) through a connecting plate (13) and can drive the presser foot rod (3) to move up and down.

2. The driving device for trimming and lifting the presser foot of a sewing machine according to claim 1, wherein a mounting seat (14) is fixedly arranged on the machine shell (1), and the driving motor (5) is fixed on the mounting seat (14) through a connecting bolt (15); the thread cutting shaft (7) is hinged to the mounting seat (14), and the presser foot lifting shaft (6) is rotatably arranged on the machine shell (1).

3. The drive device for trimming and lifting presser foot on sewing machine according to claim 2, characterized in that said drive motor (5) is a stepping motor; the thread cutting shaft (7) and the presser foot lifting shaft (6) are arranged in parallel at intervals.

4. The driving device for trimming and presser foot lifting of a sewing machine according to claim 2 or 3, characterized in that a presser foot lifting wrench (16) is hinged on the machine shell (1), one end of the presser foot lifting wrench (16) is provided with a wrenching part (16a), the upper end of the presser foot lifting swing rod (12) is fixedly connected to the other end of the presser foot lifting wrench (16), the lower end of the presser foot lifting swing rod (12) extends downwards, and the side part can abut against the presser foot lifting cam (9); a pressure lifting and pressing foot crank (17) is fixedly arranged on the pressure lifting and pressing foot shaft (6), the outer end of the pressure lifting and pressing foot crank (17) is hinged with a connecting arm (18), and the connecting arm (18) is connected with a pressure lifting and pressing foot wrench (16) through a wrench shaft (19) and a wrench crank (20).

5. The driving device for trimming and lifting the presser foot on the sewing machine according to claim 4, wherein a lifting block (21) is fixedly arranged on the presser foot rod (3), a connecting plate crank (28) is fixedly arranged at the end of the presser foot lifting shaft (6), one end of the connecting plate (13) is hinged with the outer end of the connecting plate crank (28), a strip-shaped hole (13a) along the length direction of the connecting plate (13) is formed at the other end of the connecting plate (13), and a shaft position screw (23) inserted into the strip-shaped hole (13a) is fixedly arranged on the lifting block (21); and a presser foot reset shaft spring (24) is sleeved on the presser foot lifting shaft (6).

6. The driving device for trimming and presser foot lifting on a sewing machine according to claim 2 or 3, wherein the trimming crank (10) is fixedly arranged on the trimming shaft (7), the mounting seat (14) is provided with a swinging connecting rod (25), the upper end of the swinging connecting rod (25) is hinged on the mounting seat (14), and the lower end of the swinging connecting rod (25) is movably connected with the trimming crank (10) through a connecting short plate.

7. The driving device for trimming and presser foot lifting on a sewing machine according to claim 6, wherein said mounting seat (14) has two mounting plates (14a) arranged in parallel and spaced at a distance near the lower end, said trimming spool (7) is slidably arranged on the two mounting plates (14a), said trimming crank (10) is located between the two mounting plates (14a), said trimming spool (7) is further sleeved with a trimming return shaft spring (26), and two ends of said trimming return shaft spring (26) respectively act on said trimming crank (10) and one of the mounting plates (14 a).

8. The driving device for trimming and presser foot lifting on a sewing machine according to claim 7, wherein the middle part of the swing link (11) is hinged on the machine base (2), the end part of the trimming shaft (7) is connected with a pulling plate (27) through a connecting column, the pulling plate (27) is hinged with one end of the swing link (11), and the other end of the swing link (11) is connected with the trimming mechanism (4).

9. The driving device for trimming and presser foot lifting of a sewing machine according to claim 8, wherein said trimming mechanism (4) comprises an upper blade holder (41), a movable blade (43) fixed to an end of the upper blade holder (41), a lower blade holder (42), and a stationary blade (44) fixed to an end of the lower blade holder (42); the upper tool rest (41) is movably arranged on the base (2), the lower tool rest (42) is fixedly arranged on the base (2), a groove (41a) is formed in one side of the middle of the upper tool rest (41), and the end portion of the swing rod (11) is inserted into the groove (41 a).

10. The driving device for trimming and lifting the presser foot on the sewing machine according to claim 1, 2 or 3, wherein the trimming cam (8) and the presser foot lifting cam (9) are provided with idle stroke parts (9a), and the axial symmetry line of the idle stroke part (9a) on the trimming cam (8), the axial symmetry line of the convex part (9b) and one radial center line of the output shaft of the driving motor (5) are collinear; the axial symmetry line of the idle stroke part (9a) on the pressure lifting and pressing foot cam (9), the axial symmetry line of the protruding part (9b) and one radial center line of the output shaft of the driving motor (5) are collinear.