A sewing machine with a novel presser foot lifting structure and thread trimming structure

Abstract

This patent belongs to the technical field of sewing equipment, and specifically refers to a sewing machine with a new presser foot lifting structure and a thread trimming structure, including a feed shaft, a tooth lifting shaft, a presser foot lifting assembly, a thread trimming assembly and a first motor, and also includes: a linkage sleeve, which is sleeved on the feed shaft and driven to swing by the first motor; a second crank is fixed to one end of the linkage sleeve; a presser foot lifting cam is fixed on the motor shaft of the first motor and driven to swing by the first motor; this patent uses the structure of the linkage sleeve to realize the thread trimming action and the presser foot lifting action through the forward and reverse rotation of a single stepping motor, and since the first motor is arranged on one side of the sewing machine casing, it does not occupy the internal volume of the sewing machine and is easy to install.

Description

Technical Field

[0001] This patent belongs to the technical field of sewing equipment, and specifically refers to a sewing machine with a new presser foot lifting structure and a thread cutting structure. Background Art

[0002] Chinese invention patent CN201910097866 discloses a sewing machine thread trimming, presser foot lifting and dense stitching device and a sewing machine, which includes a power part, a thread trimming cam and a transmission assembly. The power part drives the thread trimming cam and the transmission assembly to rotate synchronously, and the transmission assembly drives the presser foot lifting and dense stitching driving shaft to rotate. The presser foot lifting and dense stitching driving shaft is provided with a presser foot lifting crank and a dense stitching cam. The thread trimming contour surface on the thread trimming cam can cooperate with the thread trimming ball on the thread trimming driving crank to drive the thread trimming driving crank to rotate and drive the thread trimming mechanism to perform the thread trimming action. The rotation of the presser foot lifting crank can drive the presser foot lifting mechanism to perform the presser foot lifting action. The dense stitching contour surface on the dense stitching cam can drive the stitch length adjustment mechanism to perform the stitch length adjustment action.

[0003] The invention has the following defects:

[0004] The motor is arranged at the lower end of the sewing machine casing. Since the overall size of the motor is large, it is not convenient to install it and it will make it difficult to arrange the internal parts of the sewing machine. Summary of the invention

[0005] The purpose of this patent is to provide a sewing machine with a new presser foot lifting structure and a thread cutting structure, which has a simple layout, is easy to assemble, and has a good driving effect.

[0006] The purpose of this patent is achieved in this way:

[0007] A sewing machine with a novel presser foot lifting structure and a thread trimming structure comprises a feeding shaft, a tooth lifting shaft, a presser foot lifting assembly, a thread trimming assembly and a first motor, and also comprises:

[0008] A linkage sleeve is sleeved on the feeding shaft and driven to swing by the first motor; a second crank is fixed to one end of the linkage sleeve;

[0009] A presser foot lifting cam is fixed on the motor shaft of the first motor and driven by the first motor to swing; a stopper is provided on the upper side of the presser foot lifting cam, the lower end of the stopper abuts against the wheel surface of the presser foot lifting cam, a presser foot lifting connecting rod is fixed on the stopper, and the upper end of the presser foot lifting connecting rod is connected to the presser foot lifting assembly;

[0010] The thread trimmer crank is driven by the swinging part of the second crank; the thread trimmer crank is fixed on the thread trimmer shaft of the thread trimmer assembly.

[0011] Furthermore, the presser foot lifting cam and the stop seat, and the swinging portion of the second crank and the thread trimming crank can be separated intermittently;

[0012] When the presser foot lifting cam drives the stopper, the swinging portion of the second crank is separated from the thread trimming crank;

[0013] When the swinging part of the second crank drives the thread trimming crank, the presser foot lifting cam is separated from the stop seat.

[0014] Furthermore, a fine-tuning assembly is provided at the upper end of the presser foot lifting connecting rod, including:

[0015] A driving block, the outer end of which is connected to the presser foot lifting assembly, and a threaded hole is provided in the driving block;

[0016] The adjusting bolt is rotatably arranged in the threaded hole; the lower end of the adjusting bolt is fixedly connected to the upper end of the presser foot lifting connecting rod.

[0017] Furthermore, a spring is mounted on the adjusting bolt, and the spring abuts between the head of the adjusting bolt and the driving block.

[0018] Furthermore, two presser foot lifting cams are provided, which are respectively arranged on the motor shaft of the first motor in front and behind, and a limiting groove is formed between the two presser foot lifting cams; the presser foot lifting connecting rod is arranged in the limiting groove.

[0019] Furthermore, the left and right sides of the butt seat are both provided with abutment bosses extending downwards, and the two abutment bosses are respectively abutted on one side plane of the two presser foot lifting cams.

[0020] Furthermore, the thread trimmer crank is provided with a strip groove, and one end of the strip groove is provided with an opening;

[0021] The swinging portion of the second crank slides in the strip-shaped groove and drives the thread trimming crank;

[0022] When the lifting seat drives the presser foot lifting connecting rod, the swinging portion of the second crank is separated from the thread trimming crank from the opening.

[0023] Furthermore, a first crank is fixed to the other end of the linkage sleeve, and the first crank is connected to a driving connecting rod; a motor crank is fixed to the motor shaft of the first motor, and two ends of the driving connecting rod are respectively connected to the motor crank and the first crank.

[0024] Furthermore, a connecting plate is provided on one side of the motor crank, through which a mounting shaft axially opposite to the motor shaft of the first motor is connected, and the presser foot lifting cam is provided on the mounting shaft.

[0025] Furthermore, it also includes:

[0026] The second motor drives the needle distance adjustment component; the needle distance adjustment component controls the reverse stitching or forward stitching of the needle distance, and the needle distance is set by the needle distance adjustment component.

[0027] Furthermore, a gear assembly is provided on the motor shaft of the first motor, the gear assembly includes a driving wheel provided on the motor shaft and a driven wheel meshing with the driving wheel, the driven wheel drives a driven shaft, and the driven shaft is connected to the motor crank

[0028] Compared with the prior art, the outstanding and beneficial technical effects of this patent are:

[0029] This patent uses the structure of the linkage sleeve to realize the thread trimming action and the presser foot lifting action through the forward and reverse rotation of a single stepping motor. Since the first motor is arranged on one side of the sewing machine housing, it does not occupy the internal volume of the sewing machine, which is convenient for installation, and makes the overall layout simple and the coordination between various parts is good. At the same time, this patent realizes the separation of the thread trimming action and the presser foot lifting action through the intermittent separation structure between the lifting seat and the presser foot lifting connecting rod and between the swing part of the second crank and the thread trimming crank, so as to prevent their synchronous operation from affecting the use of the sewing machine.

[0030] The presser foot lifting assembly in this patent is also equipped with a fine-tuning assembly. When the presser foot lifting cam or the butt seat is worn for a long time, the gap between the presser foot lifting cam and the butt seat increases, causing the presser foot to be unable to be lifted to the original height. The user can turn the adjusting bolt downward to move the presser foot lifting connecting rod downward to reduce the distance between the butt block and the presser foot lifting cam, thereby compensating for the lifting height difference caused by the wear of the presser foot lifting cam or the butt seat.

[0031] There are two presser foot lifting cams in this patent, and a limiting groove is formed between the two presser foot lifting cams. The left and right sides of the abutment seat are provided with abutment bosses extending downward; the limiting groove and the abutment boss are used to prevent the presser foot lifting connecting rod from shifting to one side during operation, thereby affecting the lifting of the presser foot. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic structural diagram of Example 1;

[0033] Figure 2 It is a schematic diagram of the structure of the linkage sleeve in Example 1.

[0034] Figure 3 It is a schematic diagram of the explosion at the linkage sleeve in Example 1.

[0035] Figure 4 It is an exploded schematic diagram of the presser foot lifting connecting rod in Example 1.

[0036] Figure 5 yes Figure 2 Enlarged view of point A in the middle.

[0037] Figure 6 This is a schematic diagram of the first motor in Example 2.

[0038] The meaning of the symbols in the figure:

[0039] 1. Feeding shaft; 2. Tooth lifting shaft; 3. Presser foot lifting assembly; 31. Presser foot rod; 4. Thread trimming assembly; 41. Thread trimming shaft; 5. First motor; 51. Motor shaft; 52. Motor crank; 53. Driving connecting rod; 54. Connecting plate; 55. Mounting shaft; 56. Driving gear; 57. Driven gear; 58. Driven shaft; 6. Linkage sleeve; 61. First crank; 7. Second crank; 71. Swinging part; 81. Presser foot lifting cam; 82. Butt seat; 83. Presser foot lifting connecting rod; 84. Driving block; 85. Threaded hole; 86. Adjusting bolt; 87. Spring; 88. Limiting groove; 89. Butt boss; 9. Thread trimming crank; 91. Strip groove; 92. Opening; 10. Second motor; 11. Stitch adjustment assembly. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with specific embodiments:

[0041] Embodiment 1:

[0042] A sewing machine with a novel presser foot lifting structure and a thread trimming structure, comprising a feed shaft 1, a thread lifting shaft 2, a presser foot lifting assembly 3, a thread trimming assembly 4 and a first motor 5;

[0043] like Figure 1 As shown, the feeding shaft 1 and the tooth lifting shaft 2 are used to drive the tooth lifting assembly to rotate reciprocatingly in a circular manner to feed the teeth; the presser foot lifting assembly 3 is used to lift the presser foot, and its left end is connected to the presser foot rod 31 of the sewing machine, and the presser foot rod 31 drives the presser foot, and the right end of the presser foot lifting assembly 3 is connected to the longitudinally arranged presser foot lifting connecting rod 83; the thread trimming assembly 4 is arranged on one side of the tooth lifting assembly, and the thread is trimmed by driving the moving knife in the thread trimming assembly 4 to move toward the top knife. The above-mentioned tooth lifting assembly, thread trimming assembly 4 and presser foot lifting assembly 3 are all existing structures, and this patent will not go into details; the first motor 5 is a stepping motor, which is arranged on the right side of the overall sewing machine casing, and is relatively easy to install, and has less impact on the layout of the internal parts of the sewing machine.

[0044] Furthermore, it also includes a linkage sleeve 6, which is sleeved on the feeding shaft 1 and driven to swing by the first motor 5; a second crank 7 is fixed to one end of the linkage sleeve 6;

[0045] A presser foot lifting cam 81 is fixed on the motor shaft 51 of the first motor 5 and is driven by the first motor 5 to swing; a stopper 82 is provided on the upper side of the presser foot lifting cam 81, the lower end of the stopper 82 abuts against the wheel surface of the presser foot lifting cam 81, a presser foot lifting connecting rod 83 is fixed on the stopper 82, and the upper end of the presser foot lifting connecting rod 83 is connected to the presser foot lifting assembly 3;

[0046] The thread trimmer crank 9 is driven by the swinging portion 71 of the second crank 7 ; the thread trimmer crank 9 is fixed on the thread trimmer shaft 41 of the thread trimmer assembly 4 .

[0047] like Figure 2 As shown, a first crank 61 is fixed to the other end of the linkage sleeve 6, and the first crank 61 is connected to a driving connecting rod 53; a motor crank 52 is fixed to the motor shaft 51 of the first motor 5, and the two ends of the driving connecting rod 53 are respectively connected to the motor crank 52 and the first crank 61. A bearing member is provided between the linkage sleeve 6 and the feeding shaft 1 to enable the linkage sleeve 6 to rotate on the feeding shaft 1, so that the linkage sleeve 6 does not rotate with the rotation of the feeding shaft 1, so that the linkage sleeve 6 is only driven to rotate by the first motor 5; refer to Figure 2 , 3 The first crank 61 and the second crank 7 are arranged on both sides of the linkage sleeve 6 by integral molding or a clamping structure, wherein the first crank 61 is fixed on the left side of the linkage sleeve 6 by integral molding and arranged close to the first motor 5, and the second crank 7 is fixed on the right side of the linkage sleeve 6 by a clamping structure.

[0048] The sewing machine in the present invention also includes a second motor 10, which is located on the right side of the sewing machine housing. The second motor 10 is used to drive the stitch length adjustment component 11, and drives the feed shaft 1 to swing back and forth through the stitch length adjustment component 11. The stitch length adjustment component 11 is arranged on the feed shaft 18, and the stitch length adjustment component 11 includes an adjustment pendulum seat, a first connecting rod, a second connecting rod and an adjustment connecting rod. The adjustment pendulum seat, the first connecting rod, the second connecting rod and the adjustment connecting rod are connected in sequence, and the adjustment connecting rod is connected to the sewing machine main shaft; the second motor 10 is connected to the adjustment pendulum seat, and drives the adjustment connecting rod by driving the adjustment pendulum seat to work, thereby adjusting the stitch length. The present invention uses the first motor 5 and the second motor 10 to adjust the stitch length and lift the presser foot and trim the thread respectively, and uses the linkage sleeve 6 to make the sewing machine's lifting teeth, lifting the presser foot and trimming the thread independently operate without interfering with each other, and greatly reduces the number of parts, thereby reducing costs and reducing assembly difficulty.

[0049] Specifically, when the present invention is working, the presser foot lifting cam 81 and the stop 82, and the swinging portion 71 of the second crank 7 and the thread trimming crank 9 can be separated intermittently;

[0050] When the presser foot lifting cam 81 drives the stop 82, the swinging portion 71 of the second crank 7 is separated from the thread trimming crank 9;

[0051] When the swinging portion 71 of the second crank 7 drives the thread trimming crank 9 , the presser foot lifting cam 81 is separated from the stop seat 82 .

[0052] Combination Figure 2 , 3 As shown, a clamp is provided at one end of the motor crank 52, which is integrally formed with the motor crank 52, and the motor crank 52 is fixed to the motor shaft 51 of the first motor 5 by the clamp; an axially arranged connecting plate 54 is provided on one side of the motor crank 52, and a mounting shaft 55 is connected through the connecting plate 54, and the mounting shaft 55 is axially opposite to the motor shaft 51 of the first motor 5, and the mounting shaft 55 is integrally formed with the connecting plate 54 and the motor crank 52, and the mounting shaft 55 is supported on the outside of the motor crank 52 by the connecting plate 54, and a gap for placing the driving connecting rod 53 is formed between the motor crank 52 and the mounting shaft 55.

[0053] The presser foot lifting cam 81 is integrally formed on the mounting shaft 55, and a stop 82 is provided on the upper side of the presser foot lifting cam 81, and the lower end of the stop 82 abuts against the wheel surface of the presser foot lifting cam 81, and a presser foot lifting connecting rod 83 is fixed on the stop 82, and the presser foot lifting connecting rod 83 is longitudinally arranged and connected to the presser foot lifting assembly 3. In this patent, the raised portion on the presser foot lifting cam 81 faces the front side of the sewing machine. When working, the first motor 5 rotates upward, driving the presser foot lifting cam 81 to rotate a fixed angle, and causing the raised portion of the presser foot lifting cam 81 to move upward and abut against the bottom of the butt seat 82. The butt seat 82 is lifted by the upward rotation of the presser foot lifting cam 81, and the presser foot lifting connecting rod 83 is driven to rise. The rise of the presser foot lifting connecting rod 83 drives each component of the presser foot lifting assembly 3 in turn, and finally drives the presser foot rod 31 to rise, completing the presser foot lifting; when the presser foot needs to be lowered, the first motor 5 rotates downward in the opposite direction, causing the non-raised portion of the presser foot lifting cam 81 to abut against the bottom of the butt seat 82 or directly separating the presser foot lifting cam 81 from the butt seat 82, thereby causing the butt seat 82 to descend, and then causing the presser foot rod 31 to descend. At this time, the presser foot rod 31 loses the supporting force to lift it up and descends due to the gravity of the presser foot rod 31 itself, thereby causing the presser foot to descend.

[0054] It should be noted that generally, the presser foot rod 31 is provided with an elastic member for pressing the presser foot. The presser foot lifting action in the sewing machine is to overcome the elastic member to make the presser foot rod 31 rise to lift the presser foot. On the contrary, when the sewing machine no longer lifts the presser foot, the elastic member will press the presser foot rod 31 downward and reset the presser foot lifting assembly 3 at the same time. The resetting of the presser foot lifting assembly 3 will cause the presser foot lifting connecting rod 83 to drop to a specified position. In this patent, since the presser foot lifting cam 81 and the butt 82 are in contact with each other, the user can adjust the position between the presser foot lifting cam 81 and the butt 82. When the presser foot lifting cam 81 does not rotate to lift the presser foot, the presser foot lifting cam 81 is separated from the butt 82. Only when the presser foot lifting cam 81 rotates upward so that the raised part on the presser foot lifting cam 81 faces the butt 82, the presser foot lifting cam 81 is abutted against the butt 82 to lift the presser foot due to the change in the position of the raised part of the presser foot lifting cam 81.

[0055] The thread trimming action in this patent is also completed by the first motor 5. When trimming the thread, the first motor 5 rotates downward, driving the motor crank 52 to rotate downward, and driving the first crank 61 to swing downward by driving the connecting rod 53. While the first crank 61 swings downward, the second crank 7 is driven to swing downward through the linkage sleeve 6. The swinging part 71 of the second crank 7 is connected to the thread trimming crank 9, and the thread trimming assembly 4 is driven to work through the thread trimming crank 9, so that the thread trimming assembly 4 is driven to work through the downward movement of the second crank 7 to perform thread trimming.

[0056] By changing the structure of the thread trimmer crank 9, the swinging portion 71 of the second crank 7 and the thread trimmer crank 9 can be intermittently separated. Figure 3 , 5 The thread trimming crank 9 is provided with a strip groove 91, and one end of the strip groove 91 is provided with an opening 92; wherein, the thread trimming crank 9 is connected to the thread trimming assembly 4 in the form of a clamp, and the strip groove 91 is integrally formed beside the clamp, the strip groove 91 is arranged to be inclined downward, and is provided with a vertical opening 92, the swinging portion 71 of the second crank 7 is specifically a horizontal axis arranged at the end of the second crank 7, and the horizontal axis is located in the strip groove 91, when the second crank 7 swings downward, the thread trimming crank 9 is pushed downward by the swinging portion 71 to swing downward for thread trimming, and when the second crank 7 is upward, the horizontal axis swings upward and disengages from the strip groove 91 from the opening 92, thereby separating the thread trimming crank 9 from the second crank 7, so that the two are no longer linked.

[0057] This patent realizes the thread trimming action and presser foot lifting action through the structure of the linkage sleeve 6 and the forward and reverse rotation of a single stepping motor, and because the first motor 5 is arranged on one side of the sewing machine housing, it does not occupy the internal volume of the sewing machine, which is convenient for installation, and makes the overall layout simple and the coordination between various parts is good. At the same time, this patent realizes the separation of the thread trimming action and the presser foot lifting action through the intermittent separation structure between the lifting seat and the presser foot lifting connecting rod 83 and between the swinging part 71 of the second crank 7 and the thread trimming crank 9, so as to prevent their synchronous operation from affecting the use of the sewing machine.

[0058] Furthermore, a fine-tuning assembly is provided at the upper end of the presser foot lifting connecting rod 83, including:

[0059] A driving block 84, the outer end of which is connected to the presser foot lifting assembly 3, and a threaded hole 85 is provided in the driving block 84;

[0060] The adjusting bolt 86 is rotatably disposed in the threaded hole 85 ; the lower end of the adjusting bolt 86 is fixedly connected to the upper end of the presser foot lifting connecting rod 83 .

[0061] like Figure 4 As shown, the driving block 84 includes a square connecting block, and a connecting rod for connecting the presser foot lifting assembly 3 is provided on the side of the driving block 84 facing the presser foot lifting assembly 3, and a longitudinal threaded hole 85 is provided in the middle of the driving block 84; the adjusting bolt 86 is longitudinally arranged in the driving block 84, and a connecting hole is provided at the lower end of the adjusting bolt 86, and the upper end of the presser foot lifting connecting rod 83 is connected through the connecting hole. The fine adjustment assembly is generally used when the presser foot lifting cam 81 or the butt 82 is worn for a long time, and the gap between the presser foot lifting cam 81 and the butt 82 increases, so that the presser foot cannot be lifted to the original height. The user can reduce the distance between the butt block and the presser foot lifting cam 81 by turning the adjusting bolt 86 downward to make the presser foot lifting connecting rod 83 move downward, thereby compensating for the lifting height difference caused by the wear of the presser foot lifting cam 81 or the butt 82.

[0062] Furthermore, the adjusting bolt 86 is also provided with a spring 87, which abuts up and down between the head of the adjusting bolt 86 and the driving block 84. The spring 87 can be used to limit the maximum adjustment distance, that is, when the adjusting bolt 86 is turned downward, the upward reaction force of the spring 87 will prompt the user to prevent the user from over-adjusting and causing damage to the presser foot lifting cam 81.

[0063] Furthermore, two presser foot lifting cams 81 are provided, which are respectively arranged on the motor shaft 51 of the first motor 5 in front and back, and a limiting groove 88 is formed between the two presser foot lifting cams 81; the presser foot lifting connecting rod 83 is arranged in the limiting groove 88. Figure 1 , 4The two presser foot lifting cams 81 are respectively arranged at the front and rear ends of the mounting shaft 55, and the limiting groove 88 is formed between the inner side surfaces of the presser foot lifting cams 81; the presser foot lifting connecting rod 83 has a certain length, which is through-set on the stop seat 82 and connected to the stop seat 82; when working, the presser foot lifting connecting rod 83 is located in the limiting groove 88, and the limiting groove 88 is used to prevent the presser foot lifting connecting rod 83 from deviating to one side during work, thereby affecting the lifting of the presser foot.

[0064] Furthermore, the left and right sides of the abutment seat 82 are both provided with abutment bosses 89 extending downward. Figure 2 As shown, the distance between the two abutment bosses 89 can just accommodate the two presser foot lifting cams 81. When the presser foot lifting cams 81 rotate upward, the two presser foot lifting cams 81 can be embedded between the two abutment bosses 89, so that the two abutment bosses 89 are respectively abutted on one side plane of the two presser foot lifting cams 81; the abutment bosses 89 can further limit the presser foot lifting connecting rod 83 to prevent the presser foot lifting connecting rod 83 from shifting to one side during operation.

[0065] Embodiment 2:

[0066] Most structures of this embodiment are the same as those of the embodiment 1, except that: a reduction gear assembly is provided on the motor shaft 51 of the first motor 5, and a driving connecting rod 53 for driving the linkage sleeve 6 to move is connected through the reduction gear assembly; wherein the reduction gear assembly includes a driving gear 56 provided on the motor shaft 51 and a driven gear 57 provided on the upper end of the driving gear 56, and a driven shaft 58 is provided in the driven gear 57, and the driven shaft 58 is generally fixed on the housing of the first motor 5 or the housing of the sewing machine, and the motor crank 52 is provided on the driven shaft 58, and the driving connecting rod 53 is connected through the motor crank 52. The purpose of providing the reduction gear assembly is to increase the torque of the first motor 51 through the reduction gear assembly, and to reduce the rated power required by the first motor 5, reduce the size of the first motor 5, and thus reduce the purchase cost of the motor, under the premise that the first motor 5 can provide sufficient driving force for the driving connecting rod 53.

[0067] The above embodiments are only preferred embodiments of this patent and are not intended to limit the protection scope of this patent. Therefore, any equivalent changes made based on the structure, shape, and principle of this patent should be covered within the protection scope of this patent.

Claims

1. A sewing machine with a novel presser foot lifting structure and a thread trimming structure, comprising a feed shaft (1), a thread lifting shaft (2), a presser foot lifting assembly (3), a thread trimming assembly (4) and a first motor (5), characterized in that: Also includes: A linkage sleeve (6) is sleeved on the feeding shaft (1) and driven to swing by the first motor (5); a second crank (7) is fixed to one end of the linkage sleeve (6); A presser foot lifting cam (81) is fixed on the motor shaft (51) of the first motor (5) and driven by the first motor (5) to swing; a stopper (82) is provided on the upper side of the presser foot lifting cam (81), the lower end of the stopper (82) abuts against the wheel surface of the presser foot lifting cam (81), a presser foot lifting connecting rod (83) is fixed on the stopper (82), and the upper end of the presser foot lifting connecting rod (83) is connected to the presser foot lifting assembly (3); A thread trimmer crank (9) is driven by the swinging portion (71) of the second crank (7); the thread trimmer crank (9) is fixed on the thread trimmer shaft (41) of the thread trimmer assembly (4); The presser foot lifting cam (81) and the stop seat (82), and the swinging portion (71) of the second crank (7) and the thread trimming crank (9) can be separated intermittently; When the presser foot lifting cam (81) drives the stopper (82), the swinging portion (71) of the second crank (7) is separated from the thread trimming crank (9); When the swinging portion (71) of the second crank (7) drives the thread trimming crank (9), the presser foot lifting cam (81) is separated from the stop seat (82); The upper end of the presser foot lifting connecting rod (83) is provided with a fine adjustment component, including: A driving block (84), the outer end of the driving block (84) is connected to the presser foot lifting assembly (3), and a threaded hole (85) is provided in the driving block (84); An adjusting bolt (86) is rotatably disposed in the threaded hole (85); the lower end of the adjusting bolt (86) is fixedly connected to the upper end of the presser foot lifting connecting rod (83); The thread trimmer crank (9) is provided with a strip groove (91), and one end of the strip groove (91) is provided with an opening (92); The swinging portion (71) of the second crank (7) slides in the strip groove (91) and drives the thread trimming crank (9); When the presser foot lifting cam (81) drives the stop seat (82), the swinging portion (71) of the second crank (7) is separated from the thread trimming crank (9) from the opening (92); The sewing machine with the novel presser foot lifting structure and thread cutting structure also includes: The second motor (10) drives the needle distance adjustment component (11); the needle distance adjustment component (11) controls the reverse stitching or forward stitching of the needle distance, and the needle distance is set by the needle distance adjustment component (11).

2. The sewing machine with a novel presser foot lifting structure and a thread trimming structure according to claim 1, characterized in that: The adjusting bolt (86) is also provided with a spring (87), and the spring (87) abuts between the head of the adjusting bolt (86) and the driving block (84) in an upper and lower manner.

3. The sewing machine with a novel presser foot lifting structure and a thread trimming structure according to claim 1, characterized in that: Two presser foot lifting cams (81) are provided, which are respectively arranged on the motor shaft (51) of the first motor (5) in front and back, and a limiting groove (88) is formed between the two presser foot lifting cams (81); the presser foot lifting connecting rod (83) is arranged in the limiting groove (88).

4. The sewing machine with a novel presser foot lifting structure and a thread trimming structure according to claim 3 is characterized in that: The left and right sides of the buttress (82) are both provided with abutment bosses (89) extending downwards, and the two abutment bosses (89) are respectively abutted on one side plane of the two presser foot lifting cams (81).

5. The sewing machine with a novel presser foot lifting structure and a thread trimming structure according to claim 1 or 2, characterized in that: A first crank (61) is fixed to the other end of the linkage sleeve (6), and the first crank (61) is connected to a driving connecting rod (53); a motor crank (52) is fixed to the motor shaft (51) of the first motor (5), and two ends of the driving connecting rod (53) are respectively connected to the motor crank (52) and the first crank (61).

6. The sewing machine with a novel presser foot lifting structure and a thread trimming structure according to claim 5, characterized in that: A connecting plate (54) is also provided on one side of the motor crank (52), and a mounting shaft (55) axially opposite to the motor shaft (51) of the first motor (5) is connected via the connecting plate (54), and the presser foot lifting cam (81) is provided on the mounting shaft (55).

7. The sewing machine with the novel presser foot lifting structure and thread trimming structure according to claim 6 is characterized in that: A gear assembly is provided on the motor shaft (51) of the first motor (5), the gear assembly comprising a driving gear (56) arranged on the motor shaft (51) and a driven gear (57) meshing with the driving gear (56), the driven gear (57) driving a driven shaft (58), and the driven shaft (58) is connected to the motor crank (52).

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