Sewing machine and control method thereof

Abstract

The present invention provides a sewing machine and a control method thereof. The sewing machine includes a thread trimming mechanism, a first drive source, a second drive source, a first thread trimming drive element driven and rotated by the first drive source, and a second thread trimming drive element driven and rotated by the second drive source. The thread trimming mechanism includes a movable active knife and an auxiliary movable knife, a first thread trimming transmission unit connected between the first thread trimming drive element and the active knife, and a second thread trimming transmission unit connected between the second thread trimming drive element and the auxiliary movable knife. The active knife is provided with a wire dividing groove, a wire hook groove capable of allowing a sewing machine needle to pass through, and a first thread trimming blade. The auxiliary movable knife is provided with a second thread trimming blade, and the first thread trimming blade is capable of engaging with the second thread trimming blade. In the sewing machine involved in the present application, two drive sources are used to drive the active knife and the auxiliary movable knife respectively. In this way, thread trimming can be achieved at the beginning of sewing and at the end of sewing, thereby effectively improving sewing quality.

Description

Technical Field

[0001] The present invention relates to clothing sewing equipment, in particular to a sewing machine and a control method thereof. Background Art

[0002] A sewing machine uses one or more sewing threads to create one or more stitches on fabric, interweaving or stitching one or more layers of fabric. It primarily consists of a base (i.e., housing and bottom plate), a needle bar mechanism, a feed mechanism, a thread hook mechanism, a presser foot mechanism, a thread trimmer mechanism, and accessories. Through the coordinated movement of these mechanisms, the fabric is stitched together in a cycle.

[0003] Currently, sewing machines use functions such as automatic presser foot lifting, automatic thread trimming, tooth height adjustment, and bird nest prevention during the sewing process. A common method is to use an electromagnet or a stepper motor to drive the presser foot lifting and thread trimming mechanisms to achieve automatic presser foot lifting and automatic thread trimming, and another motor to adjust the tooth height. For example, Chinese invention patent application number 202010196339.9 discloses a tooth lifting shaft assembly and a sewing machine having a tooth lifting shaft assembly; another example is Chinese invention patent application number 201811350563.8 discloses a thread trimming structure and a sewing machine. However, this driving method has disadvantages such as a single driving operation, low actual utilization rate, and high cost of use. In addition, some sewing machines use a motor-driven single-moving knife structure thread trimming mechanism to achieve seam start, thread trimming, and bird nest prevention, but the residual thread is long, and there is no substantial improvement in automatic adjustment and sewing quality. Moreover, although the thread trimming mechanism in some sewing machines is a double-moving knife structure, it uses one motor to drive the two moving knives to move at the same time, which can only trim the thread after sewing is completed, but cannot trim the thread at the beginning of sewing to prevent bird nests. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a sewing machine that can perform seam starting and thread cutting.

[0005] To achieve the above-mentioned objectives, the present invention provides a sewing machine, comprising a thread trimming mechanism, a first driving source, a second driving source, a first thread trimming driving member driven to rotate by the first driving source, and a second thread trimming driving member driven to rotate by the second driving source, the thread trimming mechanism comprising a movable active knife and an auxiliary movable knife, a first thread trimming transmission unit connected between the first thread trimming driving member and the active knife, and a second thread trimming transmission unit connected between the second thread trimming driving member and the auxiliary movable knife, the active knife being provided with a wire dividing groove, a wire hooking groove capable of allowing a needle in the sewing machine to pass through, and a first thread trimming blade, the auxiliary movable knife being provided with a second thread trimming blade, and the first thread trimming blade being capable of engaging with the second thread trimming blade.

[0006] Furthermore, the first thread trimming drive component is a thread trimming drive crank, and the first thread trimming transmission unit includes a first thread trimming roller rotatably mounted on the thread trimming drive crank, a thread trimming transmission lever with a fourth fixed fulcrum, a first thread trimming connecting rod, a first thread trimming shaft rotatably supported in the sewing machine base plate, a first thread trimming crank and a second thread trimming crank respectively fixed at two ends of the first thread trimming shaft, a second thread trimming connecting rod, and a main tool holder, the thread trimming transmission lever is provided with a fork groove portion, the first thread trimming roller is slidably mounted in the fork of the fork groove portion, the two ends of the first thread trimming connecting rod are respectively hinged to the thread trimming transmission lever and the first thread trimming crank, the two ends of the second thread trimming connecting rod are respectively hinged to the second thread trimming crank and the main tool holder, and the active knife is fixed on the main tool holder.

[0007] Furthermore, the second thread trimming drive component is provided with a thread trimming arm, and the second thread trimming transmission unit includes a second thread trimming roller rotatably mounted on the thread trimming arm, a second thread trimming shaft rotatably supported in the sewing machine base plate, a thread trimming fork crank and a third thread trimming crank respectively fixed at both ends of the second thread trimming shaft, and an auxiliary knife frame, the second thread trimming roller is slidably mounted in the fork of the thread trimming fork crank, the third thread trimming crank is hinged to the auxiliary knife frame, and the auxiliary movable knife is fixed on the auxiliary knife frame.

[0008] Furthermore, the sewing machine also includes a presser foot assembly, a presser foot lifting mechanism connected to the presser foot assembly, a presser foot lifting driving member, and a presser foot lifting transmission unit, the presser foot lifting driving member is driven to rotate by a first driving source, and the presser foot lifting transmission unit is connected between the presser foot lifting driving member and the presser foot lifting mechanism.

[0009] Furthermore, the presser foot lifting mechanism includes a right lever with a first fixed fulcrum, a presser foot lifting rod, a left lever with a second fixed fulcrum, a presser foot lifting plate, a transmission guide, and a presser rod movably installed in a sewing machine housing, the two ends of the presser foot lifting rod are respectively hinged to the right lever and the left lever, the left lever and the presser foot lifting plate are hinged, the presser foot lifting plate is provided with a lifting hook, the transmission guide is provided with a connecting protrusion engaged with the lifting hook, the transmission guide is fixed to the upper end of the presser rod, and the presser foot assembly is installed at the lower end of the presser rod;

[0010] The presser foot lifting driving component is a presser foot lifting driving cam, and the presser foot lifting transmission unit includes a presser foot lifting transmission crank with a third fixed fulcrum, a presser foot lifting roller rotatably mounted on one end of the presser foot lifting transmission crank, and a presser foot lifting push rod, the presser foot lifting roller can contact and cooperate with the presser foot lifting driving cam, and the two ends of the presser foot lifting push rod are respectively hinged to the other end of the presser foot lifting transmission crank and the right lever.

[0011] Furthermore, the presser foot lifting mechanism includes a right lever with a first fixed fulcrum, a presser foot lifting rod, a left lever with a second fixed fulcrum, a pressure-adjusting slider rotatably mounted on the left lever, a pressure rod movably mounted in a sewing machine housing, a pressure-adjusting sleeve movably sleeved on the pressure rod, a pressure-adjusting spring sleeved on the pressure rod, and an upper guide frame and a lower guide frame both fixed to the pressure rod, the pressure-adjusting sleeve being provided with a pressure-adjusting slot slidably matched with the pressure-adjusting slider, the upper and lower ends of the pressure-adjusting spring respectively abutting against the pressure-adjusting sleeve and the lower guide frame, the pressure-adjusting sleeve being capable of abutting against the upper guide frame, and the presser foot assembly being mounted on the lower end of the pressure rod;

[0012] The presser foot lifting driving component is a presser foot lifting driving crank, and the presser foot lifting transmission unit includes a presser foot lifting transmission connecting rod, a presser foot lifting transmission crank with a third fixed fulcrum, and a presser foot lifting push rod. The two ends of the presser foot lifting transmission connecting rod are respectively hinged to the presser foot lifting driving crank and one end of the presser foot lifting transmission crank, and the two ends of the presser foot lifting push rod are respectively hinged to the other end of the presser foot lifting transmission crank and the right lever.

[0013] Furthermore, the sewing machine also includes a tooth rack, a feed tooth installed on the tooth rack, a tooth lifting mechanism connected to one end of the tooth rack, a tooth lifting drive component, and a tooth lifting transmission unit. The tooth lifting drive component is driven to rotate by a second driving source, and the tooth lifting transmission unit is connected between the tooth lifting drive component and the tooth lifting mechanism.

[0014] Furthermore, the tooth lifting drive component and the second thread cutting drive component are combined into a tooth lifting and thread cutting drive crank.

[0015] Furthermore, the tooth-lifting driving member is provided with a tooth-lifting arm, and the tooth-lifting mechanism includes a tooth-lifting shaft rotatably supported in the sewing machine base, a first tooth-lifting crank fixed at one end of the tooth-lifting shaft, and a first tooth-lifting connecting rod, and the two ends of the first tooth-lifting connecting rod are respectively hinged to the first tooth-lifting crank and the tooth frame; the tooth-lifting transmission unit includes a second tooth-lifting connecting rod, and a second tooth-lifting crank fixed at the other end of the tooth-lifting shaft, and the two ends of the second tooth-lifting connecting rod are respectively hinged to the tooth-lifting arm and the second tooth-lifting crank.

[0016] Furthermore, the sewing machine also includes a thread pressing plate fixed to the bottom plate of the sewing machine, and the thread pressing plate has a thread pressing head; when the sewing machine cuts the thread and starts sewing, the first driving source drives the active knife to move to the bottom of the thread pressing head through the first thread cutting drive component and the first thread cutting transmission unit, and a thread clamping cavity is formed between the active knife and the thread pressing head.

[0017] Furthermore, the first driving source and the second driving source are both motors, the first thread trimming driving component is fixed on the motor shaft of the first driving source, and the second thread trimming driving component is fixed on the motor shaft of the second driving source.

[0018] The present application also provides a sewing machine control method, using the sewing machine as described above, the sewing machine control method comprising the following steps:

[0019] S1. Configuring an electronic control module so that the first driving source and the second driving source are both communicatively connected to the electronic control module;

[0020] The working area of the first driving source has a main knife thread cutting area, and the working area of the second driving source has an auxiliary knife thread cutting area;

[0021] S2. After the sewing machine is powered on and started, the electronic control module controls the first driving source to operate to a working area other than the main knife thread trimming area, and controls the second driving source to operate to a working area other than the auxiliary knife thread trimming area, the active knife is in its retracted position, and the auxiliary moving knife is in its retracted position;

[0022] S3: After the electronic control module receives the sewing start signal, the sewing machine starts to operate:

[0023] When the needle in the sewing machine moves down and is located above the needle plate, the electronic control module controls the first driving source to run to the main knife thread cutting area, drives the active knife to cut out, and makes the thread hook groove be located directly below the needle;

[0024] The sewing machine continues to run. When the needle pierces the fabric and moves up to above the needle plate, the electronic control module controls the first drive source to reverse to the set value within the main knife thread cutting area, drives the active knife to return, and there is a sewing thread end in the thread hook groove of the active knife;

[0025] The sewing machine continues to operate. When the electronic control module determines that the feed dog in the sewing machine has moved below the upper surface of the needle plate, the electronic control module controls the second driving source to operate to the auxiliary knife thread cutting area, drives the auxiliary movable knife to cut out, and then the first thread cutting blade and the second thread cutting blade engage to cut the sewing thread end in the thread hook groove;

[0026] The electronic control module controls the first driving source to reset, and controls the second driving source to reset.

[0027] Furthermore, the sewing machine further comprises a tooth frame, a feed dog mounted on the tooth frame, a tooth lifting mechanism connected to one end of the tooth frame, a presser foot assembly, a presser foot lifting mechanism connected to the presser foot assembly, a presser foot lifting driving member driven to rotate by a first driving source, a tooth lifting driving member driven to rotate by a second driving source, a presser foot lifting transmission unit, and a tooth lifting transmission unit, wherein the presser foot lifting transmission unit is connected between the presser foot lifting driving member and the presser foot lifting mechanism, the tooth lifting transmission unit is connected between the tooth lifting driving member and the tooth lifting mechanism, and the presser foot lifting mechanism does not have a presser foot pressure adjustment function;

[0028] In step S1, the working area of the first driving source further includes a first idle stroke area and a presser foot lifting area, the main knife thread cutting area and the presser foot lifting area are distributed on both sides of the first idle stroke area, and the first idle stroke area, the main knife thread cutting area and the presser foot lifting area are three independent working areas; the working area of the second driving source further includes a tooth lifting area independent of the auxiliary knife thread cutting area, and the tooth lifting area has a lower supply area;

[0029] In step S2, the electronic control module controls the first driving source to operate in the first idle travel area, and controls the second driving source to operate in the tooth lifting area;

[0030] In step S3, when the second driving source moves into the lower feed area, the electronic control module determines that the feed dog in the sewing machine moves to below the upper surface of the needle plate.

[0031] Furthermore, the sewing machine further comprises a tooth frame, a feed dog mounted on the tooth frame, a tooth lifting mechanism connected to one end of the tooth frame, a presser foot assembly, a presser foot lifting mechanism connected to the presser foot assembly, a presser foot lifting driving member driven to rotate by a first driving source, a tooth lifting driving member driven to rotate by a second driving source, a presser foot lifting transmission unit, and a tooth lifting transmission unit, wherein the presser foot lifting transmission unit is connected between the presser foot lifting driving member and the presser foot lifting mechanism, the tooth lifting transmission unit is connected between the tooth lifting driving member and the tooth lifting mechanism, and the presser foot lifting mechanism has a presser foot pressure adjustment function;

[0032] In step S1, the working area of the first driving source further includes a presser foot pressure area and a presser foot lifting area, the main knife thread cutting area and the presser foot lifting area are distributed on both sides of the presser foot pressure area, and the presser foot pressure area, the main knife thread cutting area and the presser foot lifting area are three independent working areas; the working area of the second driving source further includes a tooth lifting area independent of the auxiliary knife thread cutting area, and the tooth lifting area has a lower supply area;

[0033] In step S2, the electronic control module controls the first driving source to operate to the presser foot pressure area, and controls the second driving source to operate to the tooth lifting area;

[0034] In step S3, when the second driving source moves into the lower feed area, the electronic control module determines that the feed dog in the sewing machine moves to below the upper surface of the needle plate.

[0035] Furthermore, the sewing machine control method also includes step S4: after the electronic control module receives the presser foot lifting signal, the electronic control module controls the first driving source to run to the presser foot lifting area, driving the presser foot assembly to move upward; after the presser foot lifting is completed, the electronic control module controls the first driving source to reset.

[0036] Furthermore, in step S4, after the presser foot assembly moves upward, the electronic control module also controls the second driving source to operate to the lower supply area, driving the feed dog to sink below the upper surface of the needle plate; after the presser foot is lifted, the electronic control module also controls the second driving source to reset.

[0037] Furthermore, the sewing machine control method also includes step S5: after the electronic control module receives the thread trimming signal, the electronic control module controls the first driving source to operate to the main knife thread trimming area, drives the active knife to cut out, and the wire dividing groove of the active knife separates the thread; then, the electronic control module controls the first driving source to operate in the reverse direction to the set value in the main knife thread trimming area, drives the active knife to return, and there is a stitch in the wire dividing groove of the active knife; the electronic control module controls the second driving source to operate to the auxiliary knife thread trimming area, drives the auxiliary movable knife to cut out, and the first thread trimming blade and the second thread trimming blade engage to cut the stitch in the wire dividing groove; the electronic control module controls the first driving source to reset, and controls the second driving source to reset.

[0038] Furthermore, the sewing machine is further provided with an air suction mechanism, the air suction mechanism including an air suction power source and an air suction port communicated with the air suction power source, the air suction port being adjacent to the engagement position of the first thread cutting blade and the second thread cutting blade, the air suction power source being communicatively connected to the electronic control module;

[0039] In step S3, when the electronic control module controls the first driving source to run to the main knife thread cutting area and makes the thread hooking groove directly below the needle, the electronic control module simultaneously controls the suction power source to start, so that negative pressure is generated at the suction port; after the active knife and the auxiliary moving knife cut off the suture thread ends in the thread hooking groove, the cut suture thread ends are sucked into the suction port; after that, the electronic control module controls the suction power source to turn off.

[0040] Furthermore, the engagement position of the first thread cutting blade and the second thread cutting blade is adjacent to the machine needle.

[0041] As described above, the sewing machine and the control method thereof according to the present invention have the following beneficial effects:

[0042] In the sewing machine involved in the present application, two driving sources are used to drive the active knife and the auxiliary movable knife respectively, so that the thread can be trimmed at the beginning of sewing and at the end of sewing, thereby effectively improving the sewing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 and Figure 2 Schematic diagram of the structure of the sewing machine of this application at different viewing angles.

[0044] Figure 3 This is a schematic diagram of a first embodiment of the connection structure between the first driving source, the presser foot lifting mechanism and the active knife in the sewing machine of the present application.

[0045] Figure 4 This is a schematic diagram of a second embodiment of the connection structure between the first driving source, the presser foot lifting mechanism and the active knife in the sewing machine of the present application.

[0046] Figure 5This is a schematic diagram of the connection structure between the first driving source, the tooth lifting mechanism and the auxiliary movable knife in the sewing machine of the present application.

[0047] Figure 6 Schematic diagram of tooth height.

[0048] Figure 7 It is a structural diagram of the thread trimming mechanism in the initial state.

[0049] Figure 8 a to Figure 8 c is a schematic diagram of the working process of the thread trimming mechanism of the sewing machine when trimming the thread at the start of sewing.

[0050] Figure 9 a to Figure 9 b is a schematic diagram of the working process of the thread trimming mechanism of the sewing machine when trimming the thread at the end of sewing.

[0051] Figure 10 for Figure 3 Schematic diagram of the distribution of the working area of the first driving source in the embodiment shown.

[0052] Figure 11 for Figure 4 Schematic diagram of the distribution of the working area of the first driving source in the embodiment shown.

[0053] Figure 12 This is a distribution diagram of the working area of the second driving source in this application.

[0054] Figure 13 This is the control principle diagram of the sewing machine in this application.

[0055] Component number description

[0056] 10 dental brackets

[0057] 20 Feed dog

[0058] 30 Tooth lifting mechanism

[0059] 31 tooth lifting axis

[0060] 32 First tooth lift crank

[0061] 33 First tooth lifting connecting rod

[0062] 40 Presser foot lifting mechanism

[0063] 41 Right lever

[0064] 42 Presser foot lifter

[0065] 43 Left lever

[0066] 44 Presser foot lift plate

[0067] 45 transmission guide

[0068] 46 pressure rod

[0069] 47 Pressure adjustment slider

[0070] 48 pressure regulating sleeve

[0071] 49 pressure regulating spring

[0072] 410 upper guide frame

[0073] 411 lower guide frame

[0074] 50 thread trimming mechanism

[0075] 51 Active Knife

[0076] 511 branch trough

[0077] 512 Wire Hook Slot

[0078] 513 First Thread Cutting Edge

[0079] 52 Auxiliary operation

[0080] 521 Second thread cutting blade

[0081] 60 Presser foot lift transmission unit

[0082] 61 Presser foot lifter drive crank

[0083] 62 Presser foot lift roller

[0084] 63 Presser foot lifter

[0085] 64 Presser foot lift transmission connecting rod

[0086] 70 tooth lifting transmission unit

[0087] 71 Second tooth lifting connecting rod

[0088] 72 Second gear crank

[0089] 80 First thread trimming transmission unit

[0090] 81 First thread trimming roller

[0091] 82 Thread trimmer transmission lever

[0092] 83 First thread trimmer link

[0093] 84 First thread trimming shaft

[0094] 85 First trimmer crank

[0095] 86 Second trimmer crank

[0096] 87 Second thread trimmer link

[0097] 88 Main tool holder

[0098] 90 Second thread trimming transmission unit

[0099] 91 Second thread trimming roller

[0100] 92 Second thread trimmer shaft

[0101] 93 Crank handle for trimmer

[0102] 94 Third trimmer crank

[0103] 95 auxiliary tool holder

[0104] 110 presser foot assembly

[0105] 120 First driving source

[0106] 130 Second driving source

[0107] 140 Presser foot lifter drive

[0108] 150 First thread trimming drive element

[0109] 160 tooth lifting drive

[0110] 170 Second thread trimming drive element

[0111] 180 wire pressing plate

[0112] 181 Pressing head

[0113] 190 air intake

[0114] 200 chassis

[0115] 210 base plate

[0116] 220 fixed bracket

[0117] 230 Seam material thickness detection mechanism DETAILED DESCRIPTION

[0118] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0119] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0120] The present application provides a sewing machine, which is a flat sewing machine. Figure 1 and Figure 2 As shown, the sewing machine comprises a fixed housing 200 and a base plate 210, a needle plate fixed to the base plate 210, a main shaft rotatably supported within the housing 200, a main motor driving the main shaft, and a needle bar mechanism connected to the main shaft, which houses a needle that reciprocates up and down. For ease of description, the main shaft's axial direction is defined as the left and right directions, with the left end of the main shaft toward the machine head and the right end toward the machine tail as the right end. The needle bar mechanism is connected to the left end of the main shaft. The direction of fabric movement during sewing is defined as the forward direction.

[0121] Furthermore, if Figures 1 to 5 As shown, the sewing machine involved in the present application also includes a tooth frame 10, a feed dog 20 fixedly mounted on the tooth frame 10, a tooth lifting mechanism 30 connected to the rear end of the tooth frame 10, a presser foot assembly 110, a presser foot lifting mechanism 40 connected to the presser foot assembly 110, a thread trimming mechanism 50, a first driving source 120, a second driving source 130, a first thread trimming driving member 150 driven to rotate by the first driving source 120, and a second thread trimming driving member 170 driven to rotate by the second driving source 130, the thread trimming mechanism 50 includes an active knife 51 and an auxiliary movable knife 52 both of which can move, a first thread trimming transmission unit 80 connected between the first thread trimming driving member 150 and the active knife 51, and a second thread trimming transmission unit 90 connected between the second thread trimming driving member 170 and the auxiliary movable knife 52; as shown Figure 8 a and Figure 8 As shown in b, the active knife 51 is provided with a wire dividing groove 511, a wire hook groove 512 that allows the needle in the sewing machine to pass through, and a first thread cutting blade 513, and the auxiliary movable knife 52 is provided with a second thread cutting blade 521, and the first thread cutting blade 513 can engage with the second thread cutting blade 521.

[0122] The present application also provides a sewing machine control method, using the above sewing machine, the sewing machine control method comprises the following steps:

[0123] S1, configure the electronic control module so that the first drive source 120 and the second drive source 130 are both connected to the electronic control module for communication; Figure 10 As shown, within the range of 360° rotation of the motor shaft of the first driving source 120, the working area of the first driving source 120 has a main knife thread cutting area A2; Figure 12 As shown, within the range of 360° rotation of the motor shaft of the second driving source 130, the working area of the second driving source 130 has an auxiliary knife thread cutting area B1, and the starting point and end point of the auxiliary knife thread cutting area B1 are α1 and α2 respectively.

[0124] S2, after the sewing machine is powered on, the electronic control module controls the first driving source 120 to operate to the working area except the main knife thread cutting area A2, and controls the second driving source 130 to operate to the working area except the auxiliary knife thread cutting area B1, such as Figure 7 As shown, the active knife 51 is at its retracted position, the auxiliary movable knife 52 is at its retracted position, and the thread trimming mechanism 50 is in an initial state.

[0125] S3. After the electronic control module receives the sewing start signal, the sewing machine starts to operate. The tooth lifting mechanism 30 in the sewing machine drives the tooth frame 10 and the feed dog 20 to move up and down. Combined with the cloth feeding mechanism in the sewing machine driving the tooth frame 10 and the feed dog 20 to move back and forth, the feed dog 20 performs a composite motion of up and down reciprocating motion and back and forth reciprocating motion, and performs normal cloth feeding. At the same time, the electronic control module sends an anti-bird nest signal, which specifically includes the following sub-steps:

[0126] S31, the electronic control module receives the signal from the spindle encoder, and determines that the sewing machine needle moves down and is above the needle plate. Figure 10 From the viewing angle, the electronic control module controls the first drive source 120 to rotate counterclockwise from the current set initial angle to the end point of the main knife thread cutting area A2. The first drive source 120 rotates the active knife 51 through the first thread cutting drive component 150 and the first thread cutting transmission unit 80, driving the active knife 51 to cut out, so that the thread hook groove 512 is located directly below the needle.

[0127] S32, the sewing machine continues to run, the needle continues to move downward, such as Figure 8 As shown in a, the needle first passes downward through the thread hook groove 512 of the active knife 51 and pierces the fabric, and then the needle moves up. When the needle moves up to above the needle plate, the electronic control module controls the first driving source 120 to run clockwise from the end point of the main knife thread cutting area A2 to the set value in the main knife thread cutting area A2, driving the active knife 51 to return the knife, as shown in FIG. Figure 8 As shown in b, the active knife 51 moves with the suture thread end, and the suture thread end is in the thread hooking groove 512 of the active knife 51.

[0128] S31, the sewing machine continues to operate. When the electronic control module determines that the feed dog 20 in the sewing machine moves to below the upper surface of the needle plate, the electronic control module controls the second driving source 130 to operate to the end point α2 of the auxiliary knife thread trimming area B1. The second driving source 130 rotates the auxiliary movable knife 52 through the second thread trimming driving member 170 and the second thread trimming transmission unit 90, driving the auxiliary movable knife 52 to cut out. Figure 8 As shown in FIG. 3 , the first thread cutting edge 513 of the active knife 51 engages with the second thread cutting edge 521 of the auxiliary movable knife 52 to cut off the suture thread ends in the thread hooking groove 512 .

[0129] S34 , the electric control module controls the first driving source 120 to reset, and controls the second driving source 130 to reset.

[0130] In the sewing machine involved in the present application, two driving sources are used to drive the active knife and the auxiliary movable knife respectively, so that the thread can be trimmed at the beginning of sewing and at the end of sewing, thereby effectively improving the sewing quality.

[0131] Furthermore, in the sewing machine involved in the present application, the first driving source 120 is also used for presser foot lifting drive, and the second driving source 130 is also used for thread lifting drive. Based on this, the sewing machine also includes a presser foot lifting driver 140 driven to rotate by the first driving source 120, a thread lifting driver 160 driven to rotate by the second driving source 130, a presser foot lifting transmission unit 60 connected between the presser foot lifting driver 140 and the presser foot lifting mechanism 40, and a thread lifting transmission unit 70 connected between the thread lifting driver 160 and the thread lifting mechanism 30. Preferably, the first driving source 120 and the second driving source 130 are both motors, preferably both stepping motors. The presser foot lifting driver 140 and the first thread cutting driver 150 are both fixed to the motor shaft of the first driving source 120 by screws, and the first driving source 120 directly drives the presser foot lifting driver 140 and the first thread cutting driver 150 to rotate. The tooth lifting drive 160 and the second thread cutting drive 170 are both fixed to the motor shaft of the second drive source 130 by screws. The second drive source 130 directly drives the rotation of the tooth lifting drive 160 and the second thread cutting drive 170. The first drive source 120 is fixed to the right end of the housing 200, and the second drive source 130 is fixed to the bottom of the base plate 210.

[0132] Furthermore, in the sewing machine involved in the present application, the presser foot lifting mechanism 40 has two embodiments: Figure 3 The illustrated embodiment 1 of the presser foot lifting mechanism 40 does not have a presser foot pressure adjustment function; Figure 4 The second embodiment of the presser foot lifting mechanism 40 shown in the figure has a presser foot pressure regulating function. Based on this, the sewing machine control method involved in this application also has two embodiments.

[0133] Sewing machine control method embodiment 1: using a configuration having Figure 3 In the sewing machine of the first embodiment of the presser foot lifting mechanism 40 shown, the presser foot lifting mechanism 40 does not have a presser foot pressure regulating function.

[0134] In step S1 of the first embodiment of the sewing machine control method, the motor shaft of the first driving source 120 rotates within a range of 360°. Figure 10 As shown, the working area of the first drive source 120 also includes a first idle travel area A1 and a presser foot lift area A3. The main knife thread trimming area A2 is located counterclockwise of the first idle travel area A1, and the presser foot lift area A3 is located clockwise of the first idle travel area A1. The first idle travel area A1, the main knife thread trimming area A2, and the presser foot lift area A3 constitute three independent working areas. The starting and ending points of the main knife thread trimming area A2 are θ1 and θ2, respectively, and the starting and ending points of the presser foot lift area A3 are θ3 and θ4, respectively. The range of the first idle travel area A1 is θ1 to θ3. When the motor shaft of the first drive source 120 is at the starting point θ3 of the presser foot lift area A3, the presser foot lift height of the sewing machine is minimum, namely zero. When the first drive source 120 is at the end point θ4 of the presser foot lift area A3, the presser foot lift height of the sewing machine is maximum.

[0135] In step S1 of the first embodiment of the sewing machine control method, the motor shaft of the second driving source 130 rotates within a range of 360°. Figure 12 As shown, the working area of the second drive source 130 also includes a tooth lifting area B2 and a second idle travel area B4. The auxiliary knife thread cutting area B1 is located on the clockwise side of the second idle travel area B4, and the tooth lifting area B2 is located on the counterclockwise side of the second idle travel area B4. The second idle travel area B4, the auxiliary knife thread cutting area B1, and the tooth lifting area B2 are three independent working areas. The tooth lifting area B2 has a lower supply area B3. The starting and ending points of the tooth lifting area B2 are α3 and α4, respectively, and the starting and ending points of the lower supply area B3 are α3 and α5, respectively. The range of the second idle travel area B4 is α1 to α3. When the motor shaft of the second driving source 130 is at the end point α5 of the lower supply area B3, the tooth height H of the sewing machine is zero; when the motor shaft of the second driving source 130 is operating in the lower supply area B3, the feed dog 20 sinks downward into the needle plate, and the feed dog 20 is lower than the upper surface of the needle plate; when the motor shaft of the second driving source 130 is operating in the working area other than the lower supply area B3 in the tooth-lifting area B2, the feed dog 20 emerges upward from the needle plate; when the motor shaft of the second driving source 130 is at the end point α4 of the tooth-lifting area B2, the tooth height H of the sewing machine is the largest. The tooth height H of the sewing machine refers to: in the process of the second driving source 130 driving the tooth frame 10 and the feed dog 20 to reciprocate up and down through the tooth-lifting driving member 160, the tooth-lifting transmission unit 70 and the tooth-lifting mechanism 30, when the feed dog 20 moves to the highest point, as shown Figure 6 As shown, the height of the feed dog 20 emerging upward from the needle plate is the vertical distance between the upper end of the feed dog 20 and the upper surface of the needle plate.

[0136] Step S2 of the first embodiment of the sewing machine control method is as follows: after the sewing machine is powered on and started, the electronic control module controls the first driving source 120 to operate to the set initial angle within the first idle stroke area A1, so that the active knife 51 is in its retracted position and the presser foot assembly 110 is in the lowered position; at the same time, the electronic control module controls the second driving source 130 to operate to the set initial angle within the tooth lifting area B2, so that the auxiliary movable knife 52 is in its retracted position. Therefore, the active knife 51 and the auxiliary movable knife 52 in the thread trimming mechanism 50 are both in their respective retracted positions, as shown in FIG. Figure 7 As shown, the thread trimming mechanism 50 is in an initial state.

[0137] Step S3 of the first embodiment of the sewing machine control method is as follows: After the electronic control module receives the sewing start signal, the electronic control module controls the second drive source 130 to swing back and forth within an angular range corresponding to the set tooth height within the tooth lifting area B2. The second drive source 130 drives the tooth carrier 10 and the feed dog 20 to reciprocate up and down through the tooth lifting drive member 160, the tooth lifting transmission unit 70, and the tooth lifting mechanism 30. In combination with the feed mechanism in the sewing machine to drive the tooth carrier 10 and the feed dog 20 to reciprocate back and forth, the feed dog 20 performs a composite motion of up and down reciprocating motion and back and forth reciprocating motion, thereby performing normal cloth feeding. At the same time, the electronic control module sends an anti-bird nesting signal, which specifically includes the following sub-steps:

[0138] S31, the electronic control module receives the signal from the spindle encoder, and determines that when the needle is moving downward and above the needle plate, Figure 10 From the viewing angle, the electronic control module controls the first drive source 120 to rotate counterclockwise from the current set initial angle to the end point θ2 of the main knife thread trimming area A2. The first drive source 120 rotates the active knife 51 through the first thread trimming drive component 150 and the first thread trimming transmission unit 80, driving the active knife 51 to cut out, so that the thread hook groove 512 is located directly below the needle.

[0139] S32, the sewing machine continues to run, the needle continues to move downward, such as Figure 8 As shown in a, the needle first passes downward through the thread hook groove 512 of the active knife 51 and then pierces the fabric, and then the needle moves up. When the needle moves up to above the needle plate, the electronic control module controls the first driving source 120 to run clockwise from the end point θ2 of the main knife thread cutting area A2 to the set value within the main knife thread cutting area A2, driving the active knife 51 to return the knife, as shown in FIG. Figure 8 As shown in b, the active knife 51 moves with the suture thread end, and the suture thread end is in the thread hooking groove 512 of the active knife 51.

[0140] S33, the sewing machine continues to operate, and when the electronic control module determines that the second driving source 130 operates into the lower feeding area B3, the feed dog 20 sinks and is lower than the upper surface of the needle plate. Figure 12From the perspective of the view, the electronic control module controls the second driving source 130 to run clockwise from the current angle in the lower supply area B3 to the end point α2 of the auxiliary knife thread trimming area B1, and the second driving source 130 rotates the auxiliary movable knife 52 through the second thread trimming driving member 170 and the second thread trimming transmission unit 90, driving the auxiliary movable knife 52 to cut out. Figure 8 As shown in Figure c, the first thread cutting blade 513 of the active knife 51 and the second thread cutting blade 521 of the auxiliary movable knife 52 engage with each other to cut off the thread ends in the thread hooking groove 512. Preferably, the engaging positions of the first thread cutting blade 513 and the second thread cutting blade 521 are distributed on one side of the needle and adjacent to the needle, so as to cut the clamped suture within the X range close to the center of the needle, as shown in Figure d. Figure 8 As shown in b, the thread ends remaining on the fabric can be shortened, achieving a short thread cutting effect.

[0141] S34: The electronic control module controls the first drive source 120 to rotate clockwise from the set value within the main knife thread trimming area A2 to the set initial angle within the first idle travel area A1. The first drive source 120 and the active knife 51 are reset. Simultaneously, the electronic control module controls the second drive source 130 to rotate counterclockwise from the end point α2 of the auxiliary knife thread trimming area B1 to the current angle within the lower feed area B3. Thus, the seam start and bird nest prevention function is achieved. Afterwards, the sewing machine sews normally, and the second drive source 130 continues to oscillate back and forth within an angular range within the tooth lifting area B2, which corresponds to the set tooth height. The first drive source 120 maintains the set initial angle within the first idle travel area A1, the presser foot assembly 110 is in the lowered position, and the thread trimming mechanism 50 is in the initial state.

[0142] Furthermore, the sewing machine control method embodiment 1 further includes step S4: after the electronic control module receives the presser foot lifting signal, the presser foot can be lifted midway or after sewing is completed. Figure 10 From a viewing angle, the electronic control module controls the first drive source 120 to rotate clockwise from the currently set initial angle to the presser foot lift area A3, driving the presser foot assembly 110 upward. The first drive source 120 can rotate clockwise to the end point θ4 of the presser foot lift area A3, at which point the presser foot lift reaches its maximum height. The first drive source 120 can also rotate clockwise to a matching angle within the presser foot lift area A3 based on the required presser foot lift height. After the presser foot assembly 110 moves upward, the electronic control module also controls the second drive source 130 to rotate from the current angle to the lower feed area B3, driving the feed dog 20 to sink below the upper surface of the needle plate. At this point, the feed dog 20 can be fed or unloaded. Since the feed dog 20 sinks, it will not contact the fabric, avoiding undesirable phenomena such as fabric dragging. After the presser foot is lifted, the electronic control module controls the first driving source 120 to rotate counterclockwise to the set initial angle in the first idle stroke area A1 and reset, and the electronic control module controls the second driving source 130 to reset to the current angle in the tooth lifting area B2.

[0143] Furthermore, the first embodiment of the sewing machine control method further includes step S5: after sewing is completed and the electronic control module receives the thread trimming signal, the electronic control module controls the first driving source 120 to rotate counterclockwise from the current set initial angle to the end point θ2 of the main knife thread trimming area A2, and drives the active knife 51 to cut out. Figure 9 As shown in a, the line dividing groove 511 of the active knife 51 is divided; then, the electronic control module controls the first driving source 120 to run clockwise from the end point θ2 of the main knife line cutting area A2 to the set value within the main knife line cutting area A2, driving the active knife 51 back, as shown in FIG. Figure 9 As shown in Figure 2b, the dividing groove 511 of the active knife 51 moves with the divided upper thread, and the upper thread is contained in the dividing groove 511 of the active knife 51. The electronic control module then controls the second drive source 130 to move to the end point θ4 of the auxiliary knife thread cutting area B1, driving the auxiliary movable knife 52 to cut. The first thread cutting blade 513 of the active knife 51 and the second thread cutting blade 521 of the auxiliary movable knife 52 engage on one side of the needle, cutting the upper thread in the dividing groove 511. Finally, the electronic control module controls the first drive source 120 to reset to its current angle within the first idle travel area A1 and controls the second drive source 130 to reset to its current angle within the tooth lifting area B2.

[0144] Sewing machine control method embodiment 2: using a configuration having Figure 4 In the sewing machine of the second embodiment of the presser foot lifting mechanism 40 shown, the presser foot lifting mechanism 40 has a presser foot pressure regulating function.

[0145] In step S1 of the second embodiment of the sewing machine control method, the motor shaft of the first driving source 120 rotates within a range of 360°. Figure 11 As shown, the working area of the first driving source 120 also includes a presser foot pressure area A4 and a presser foot lifting area A3. The main knife thread trimming area A2 is distributed on the clockwise side of the presser foot pressure area A4, and the presser foot lifting area A3 is distributed on the counterclockwise side of the presser foot pressure area A4. The presser foot pressure area A4, the main knife thread trimming area A2 and the presser foot lifting area A3 are three independent working areas. The starting point and end point of the main knife thread trimming area A2 are β1 and β2 respectively, the starting point and end point of the presser foot lifting area A3 are β3 and β4 respectively, and the range of the presser foot pressure area A4 is β1 to β3. When the motor shaft of the first driving source 120 is at the starting point β3 of the presser foot lifting area A3, the presser foot lifting height of the sewing machine is the smallest, zero, and the presser foot pressure is the smallest; when the first driving source 120 is at the end point β4 of the presser foot lifting area A3, the presser foot lifting height of the sewing machine is the largest; when the first driving source 120 is at the other end point angle β1 of the presser foot pressure area A4, the presser foot pressure is the largest. Therefore, along Figure 11As the motor shaft of the first drive source 120 rotates clockwise from β3 to β1, the presser foot pressure gradually increases. The working area of the motor shaft of the second drive source 130 is the same as that of the first embodiment of the sewing machine control method, including the independent second idle stroke area B4, auxiliary knife thread trimming area B1, and thread lifting area B2. These descriptions will not be repeated here.

[0146] Step S2 of the second embodiment of the sewing machine control method is as follows: after the sewing machine is powered on and started, the electronic control module controls the first driving source 120 to operate to the set initial angle within the presser foot pressure area A4, so that the active knife 51 is in its retracted position and the presser foot assembly 110 is in the lowered position; at the same time, the electronic control module controls the second driving source 130 to operate to the set initial angle within the tooth lifting area B2, so that the auxiliary movable knife 52 is in its retracted position. Therefore, the active knife 51 and the auxiliary movable knife 52 in the thread trimming mechanism 50 are both in their respective retracted positions, as shown in FIG. Figure 7 As shown, the thread trimming mechanism 50 is in an initial state.

[0147] Step S3 of the second embodiment of the sewing machine control method is as follows: After the electronic control module receives the sewing start signal, the electronic control module controls the second drive source 130 to swing back and forth within an angle range corresponding to the set tooth height in the tooth lifting area B2. The second drive source 130 drives the tooth carrier 10 and the feed dog 20 to reciprocate up and down through the tooth lifting drive member 160, the tooth lifting transmission unit 70, and the tooth lifting mechanism 30. In combination with the feed mechanism in the sewing machine to drive the tooth carrier 10 and the feed dog 20 to reciprocate back and forth, the feed dog 20 performs a composite motion of up and down reciprocating motion and back and forth reciprocating motion, thereby performing normal cloth feeding. At the same time, the electronic control module sends an anti-bird nesting signal, which specifically includes the following sub-steps:

[0148] S31, the electronic control module receives the signal from the spindle encoder, and determines that when the needle is moving downward and above the needle plate, Figure 11 From the viewing angle, the electronic control module controls the first driving source 120 to rotate clockwise from the current set initial angle in the presser foot pressure area A4 to the end point β2 of the main knife thread trimming area A2. The first driving source 120 rotates the active knife 51 through the first thread trimming driving component 150 and the first thread trimming transmission unit 80, driving the active knife 51 to cut out, so that the thread hooking groove 512 is located directly below the needle.

[0149] S32, the sewing machine continues to run, the needle continues to move downward, such as Figure 8 As shown in a, the needle first passes downward through the thread hook groove 512 of the active knife 51 and then pierces the fabric, and then the needle moves up. When the needle moves up to above the needle plate, the electronic control module controls the first driving source 120 to run counterclockwise from the end point β2 of the main knife thread cutting area A2 to the set value within the main knife thread cutting area A2, driving the active knife 51 to return the knife, as shown in FIG. Figure 8 As shown in b, the active knife 51 moves with the suture thread end, and the suture thread end is in the thread hooking groove 512 of the active knife 51.

[0150] S33, the sewing machine continues to operate, and when the electronic control module determines that the second driving source 130 operates into the lower feeding area B3, the feed dog 20 sinks and is lower than the upper surface of the needle plate. Figure 12 From the perspective of the view, the electronic control module controls the second driving source 130 to run clockwise from the current angle in the lower supply area B3 to the end point α2 of the auxiliary knife thread trimming area B1, and the second driving source 130 rotates the auxiliary movable knife 52 through the second thread trimming driving member 170 and the second thread trimming transmission unit 90, driving the auxiliary movable knife 52 to cut out. Figure 8 c, the first thread cutting blade 513 of the active knife 51 engages with the second thread cutting blade 521 of the auxiliary movable knife 52, cutting the thread ends in the thread hooking groove 512. Preferably, the engagement position of the first thread cutting blade 513 and the second thread cutting blade 521 is located on one side of the sewing needle and adjacent to the sewing needle, which can shorten the thread ends remaining on the fabric and achieve a short thread cutting effect.

[0151] S34: The electronic control module controls the first drive source 120 to rotate counterclockwise from the set value within the main knife thread trimming area A2 to the set initial angle within the presser foot pressure area A4. The first drive source 120 and the active knife 51 are reset. Simultaneously, the electronic control module controls the second drive source 130 to rotate counterclockwise from the end point α2 of the auxiliary knife thread trimming area B1 to the current angle within the lower feed area B3. Thus, the seam starter bird nest prevention function is achieved. Afterwards, the sewing machine sews normally, and the second drive source 130 continues to oscillate back and forth within an angular range within the tooth lifting area B2, which corresponds to the set tooth height. The first drive source 120 remains at the set initial angle within the presser foot pressure area A4, the presser foot assembly 110 is in the lowered position, and the thread trimming mechanism 50 is in its initial state.

[0152] Furthermore, the second embodiment of the sewing machine control method further includes step S4: after the electronic control module receives the presser foot lifting signal, the presser foot can be lifted midway or after sewing is completed. Figure 11From the viewing angle, the electronic control module controls the first drive source 120 to rotate counterclockwise from the current set initial angle to the presser foot lifting area A3, driving the presser foot assembly 110 to move upward; the first drive source 120 can rotate counterclockwise to the end point β4 of the presser foot lifting area A3, at which point the presser foot lifting height is maximized; the first drive source 120 can also rotate counterclockwise to a matching angle within the presser foot lifting area A3 according to the required presser foot lifting height. When the presser foot assembly 110 moves upward, the electronic control module also controls the second drive source 130 to rotate from the current angle to the lower feed area B3, driving the feed dog 20 to sink below the upper surface of the needle plate. At this time, the feed dog 20 can be fed or discharged downward. Since the feed dog 20 sinks, it will not contact the fabric, avoiding undesirable phenomena such as scraping or dragging the fabric back. After the presser foot is lifted, the electronic control module controls the first driving source 120 to rotate clockwise to the set initial angle in the presser foot pressure area A4 and reset, and the electronic control module controls the second driving source 130 to reset to the current angle in the tooth lifting area B2.

[0153] Furthermore, the second embodiment of the sewing machine control method further includes step S5: after sewing is completed and the electronic control module receives the thread trimming signal, the electronic control module controls the first driving source 120 to rotate clockwise from the current set initial angle to the end point β2 of the main knife thread trimming area A2, and drives the active knife 51 to cut out. Figure 9 As shown in a, the line dividing groove 511 of the active knife 51 is divided; then, the electronic control module controls the first driving source 120 to run counterclockwise from the end point β2 of the main knife cutting area A2 to the set value within the main knife cutting area A2, driving the active knife 51 back, as shown in FIG. Figure 9 b, the dividing groove 511 of the active knife 51 moves with the divided upper thread, and the upper thread is contained in the dividing groove 511 of the active knife 51. Next, the electronic control module controls the second drive source 130 to move to the end point β4 of the auxiliary knife thread cutting area B1, driving the auxiliary movable knife 52 to cut. The first thread cutting blade 513 of the active knife 51 and the second thread cutting blade 521 of the auxiliary movable knife 52 then engage on one side of the needle, cutting the upper thread in the dividing groove 511. Finally, the electronic control module controls the first drive source 120 to reset to the current angle within the presser foot pressure area A4, and controls the second drive source 130 to reset to the current angle within the tooth lifting area B2.

[0154] Furthermore, if Figure 13 As shown, the sewing machine is also equipped with a foot pedal, an operating screen, a sensor, a connection interface and other signal input devices that are connected to the electronic control module for communication and are used to input various instructions; for example: inputting the seam start instruction and the presser foot lift instruction through the foot pedal or the operating screen.

[0155] The following describes preferred embodiments of the presser foot lifting mechanism 40, the presser foot lifting transmission unit 60, the thread trimming mechanism 50, the first thread trimming transmission unit 80, the second thread trimming transmission unit 90, the tooth lifting mechanism 30, and the tooth lifting transmission unit 70 in the sewing machine.

[0156] Embodiment 1 of the presser foot lifting mechanism 40: Figure 3 As shown, the presser foot lifting mechanism 40 includes a right lever 41 with a first fixed fulcrum, a presser foot lifting rod 42, a left lever 43 with a second fixed fulcrum, a presser foot lifting plate 44, a transmission guide frame 45, and a pressure rod 46 that is movably installed in the sewing machine casing 200. The right end and the left end of the presser foot lifting rod 42 are respectively hinged to the right lever 41 and the left lever 43, and the left lever 43 is hinged to the presser foot lifting plate 44. A lifting hook is provided on the presser foot lifting plate 44, and a connecting protrusion that engages with the lifting hook is provided on the transmission guide frame 45. The transmission guide frame 45 is fixed to the upper end of the pressure rod 46, and the presser foot assembly 110 is installed at the lower end of the pressure rod 46; the right lever 41 and the left lever 43 are both hinged to the sewing machine casing 200 by axial screws extending forward and backward; the first embodiment of the presser foot lifting mechanism 40 does not have a presser foot pressure adjustment function. Based on the presser foot lifting mechanism 40 of this structure, the presser foot lifting driving member 140 is a presser foot lifting driving cam, and the presser foot lifting transmission unit 60 includes a presser foot lifting transmission crank 61 having a third fixed fulcrum, a presser foot lifting roller 62 rotatably mounted on one end of the presser foot lifting transmission crank 61, and a presser foot lifting push rod 63. The presser foot lifting roller 62 can contact and cooperate with the presser foot lifting driving cam, and the two ends of the presser foot lifting push rod 63 are respectively hinged to the other end of the presser foot lifting transmission crank 61 and the right lever 41. Preferably, the sewing machine further has a fixed bracket 220 fixed to the inner wall of the sewing machine housing 200, and the presser foot lifting transmission crank 61 is hinged to the fixed bracket 220 by axial screws extending left and right. When the motor shaft of the first driving source 120 is operating in the first idle stroke area A1 and the main knife thread trimming area A2, the presser foot lifting roller 62 does not contact the presser foot lifting drive cam, or the presser foot lifting roller 62 contacts the equal-diameter surface on the periphery of the presser foot lifting drive cam, then no power is transmitted between the presser foot lifting roller 62 and the presser foot lifting drive cam, the presser foot lifting transmission crank 61 does not rotate, the presser foot lifting mechanism 40 does not operate, and the presser foot lifting action is not performed. When the motor shaft of the first driving source 120 is operating in the presser foot lifting area A3, the presser foot lifting roller 62 contacts the variable-diameter surface on the periphery of the presser foot lifting drive cam, the presser foot lifting drive cam drives the presser foot lifting transmission crank 61 to rotate via the presser foot lifting roller 62, the presser foot lifting transmission crank 61 pulls the right lever 41 via the presser foot lifting push rod 63, the presser foot lifting mechanism 40 operates, and drives the presser foot assembly 110 to move upward, realizing automatic presser foot lifting.

[0157] The second embodiment of the presser foot lifting mechanism 40 is as follows: Figure 4As shown, the presser foot lifting mechanism 40 includes a right lever 41 with a first fixed fulcrum, a presser foot lifting rod 42, a left lever 43 with a second fixed fulcrum, a pressure regulating slider 47 rotatably mounted on the left lever 43, a pressure rod 46 movably mounted in the sewing machine housing 200, a pressure regulating sleeve 48 movably mounted on the pressure rod 46, a pressure regulating spring 49 mounted on the pressure rod 46, and an upper guide frame 410 and a lower guide frame 410 both fixed to the pressure rod 46. 411, a pressure-regulating groove is provided in the pressure-regulating sleeve 48 for sliding cooperation with the pressure-regulating slider 47, the upper and lower ends of the pressure-regulating spring 49 are respectively in contact with the pressure-regulating sleeve 48 and the lower guide frame 411, the pressure-regulating sleeve 48 can be in contact with the upper guide frame 410, and the presser foot assembly 110 is installed at the lower end of the pressure rod 46; the right lever 41 and the left lever 43 are hinged to the sewing machine housing 200 by axial screws extending forward and backward; the second embodiment of the presser foot lifting mechanism 40 has the function of adjusting the pressure of the presser foot. Based on the presser foot lifting mechanism 40 of this structure, the presser foot lifting driving component 140 is a presser foot lifting driving crank, and the presser foot lifting transmission unit 60 includes a presser foot lifting transmission connecting rod 64, a presser foot lifting transmission crank 61 with a third fixed fulcrum, and a presser foot lifting push rod 63. The presser foot lifting transmission crank 61 is hinged to the fixed bracket 220 through axial screws extending left and right. The two ends of the presser foot lifting transmission connecting rod 64 are respectively hinged to the presser foot lifting driving crank and one end of the presser foot lifting transmission crank 61, and the two ends of the presser foot lifting push rod 63 are respectively hinged to the other end of the presser foot lifting transmission crank 61 and the right lever 41. When the motor shaft of the first driving source 120 is running in the presser foot pressure area A4, the first driving source 120 causes the pressure regulating sleeve 48 in the presser foot lifting mechanism 40 to remain in a stable position through the presser foot lifting transmission unit 60, but the pressure regulating sleeve 48 does not abut against the upper guide frame 410, thereby maintaining a stable presser foot pressure; the output angle of the first driving source 120 in the presser foot pressure area A4 can change the height of the pressure regulating sleeve 48, thereby changing the compression degree of the pressure regulating spring 49, and achieving the adjustment of the presser foot pressure. When the motor shaft of the first driving source 120 is running in the presser foot lifting area A3, the first driving source 120 causes the pressure regulating sleeve 48 in the presser foot lifting mechanism 40 to move upward through the presser foot lifting transmission unit 60, and the pressure regulating sleeve 48 pushes the upper guide frame 410 upward, thereby driving the press rod 46 to move upward, and the press rod 46 drives the presser foot assembly 110 to move upward, achieving automatic presser foot lifting. When the motor shaft of the first driving source 120 is running in the main knife thread cutting area A2, the first driving source 120 moves the pressure regulating sleeve 48 in the presser foot lifting mechanism 40 to the lowest position through the presser foot lifting transmission unit 60, and the presser foot assembly 110 is always in a lowered state and always in a pressure state.

[0158] like Figure 3 or Figure 4As shown, the first thread trimming driving member 150 is a thread trimming driving crank, and the first thread trimming transmission unit 80 includes a first thread trimming roller 81 rotatably mounted on the thread trimming driving crank, a thread trimming transmission lever 82 having a fourth fixed fulcrum, a first thread trimming connecting rod 83, a first thread trimming shaft 84 rotatably supported in the sewing machine bottom plate 210, a first thread trimming crank 85 and a second thread trimming crank 86 respectively fixed to the right end and the left end of the first thread trimming shaft 84, a second thread trimming connecting rod 87, and And the main tool holder 88, the thread trimming transmission lever 82 is hinged to the fixed bracket 220 by the axial screws extending to the left and right, the thread trimming transmission lever 82 is provided with a fork groove portion, and the first thread trimming roller 81 is slidably installed in the fork mouth of the fork groove portion, the two ends of the first thread trimming connecting rod 83 are respectively hinged to the thread trimming transmission lever 82 and the first thread trimming crank 85, the two ends of the second thread trimming connecting rod 87 are respectively hinged to the second thread trimming crank 86 and the main tool holder 88, and the active knife 51 is fixed on the main tool holder 88. In particular, the two arms of the fork groove portion of the thread trimmer transmission lever 82 are respectively a longer upper arm and a shorter lower arm; when the motor shaft of the first drive source 120 operates within the main knife thread trimming area A2, the first thread trimmer roller 81 contacts and cooperates with both the upper long arm and the lower short arm of the fork groove portion, transmitting power and driving the active knife 51 to rotate; after the active knife 51 is reset, the first thread trimmer roller 81 slides out along the lower short arm of the fork groove portion, separating the first thread trimmer roller 81 from the fork groove portion of the thread trimmer transmission lever 82. When the motor shaft of the first drive source 120 operates within the first idle travel area A1 and the presser foot lifting area A3, no power is transmitted between the first thread trimmer roller 81 and the thread trimmer transmission lever 82, and the active knife 51 does not rotate and remains in its initial position. Preferably, a buffer pad is installed on the second thread trimmer crank 86, and the contact and cooperation between the buffer pad and the sewing machine base plate 210 realizes that the active knife 51 stops in its initial position.

[0159] like Figure 5 As shown, the tooth lifting drive member 160 and the second thread cutting drive member 170 are combined into a tooth lifting and thread cutting drive crank, and the tooth lifting and thread cutting drive crank is provided with a circumferentially staggered tooth lifting arm and a thread cutting arm, that is: the tooth lifting drive member 160 is provided with a tooth lifting arm, and the second thread cutting drive member 170 is provided with a thread cutting arm; the tooth lifting arm is connected to the tooth lifting transmission unit 70, and the thread cutting arm is connected to the second thread cutting transmission unit 90. The tooth lifting mechanism 30 includes a tooth lifting shaft 31 rotatably supported in the sewing machine base plate 210, a first tooth lifting crank 32 fixed to the left end of the tooth lifting shaft 31, and a first tooth lifting connecting rod 33, the two ends of the first tooth lifting connecting rod 33 are respectively hinged to the first tooth lifting crank 32 and the tooth frame 10; the tooth lifting transmission unit 70 includes a second tooth lifting connecting rod 71, and a second tooth lifting crank 72 fixed to the right end of the tooth lifting shaft 31, the two ends of the second tooth lifting connecting rod 71 are respectively hinged to the tooth lifting arm and the second tooth lifting crank 72. The tooth height H is adjusted by changing the swing angle range of the second driving source 130 in the tooth lifting area B2. Preferably, as Figure 3or Figure 4 As shown, the sewing machine is also equipped with a material thickness detection mechanism 230. The output of the material thickness detection mechanism 230 is connected to the electronic control module. The electronic control module automatically adjusts the output of the second drive source 130 according to the actual thickness of the sewing material, thereby automatically adjusting the tooth height H and automatically matching it to the thickness of the sewing material. When the sewing material is thicker, the tooth height H increases; when the sewing material is thinner, the tooth height H decreases.

[0160] like Figure 5 As shown, the second thread trimming transmission unit 90 includes a second thread trimming roller 91 rotatably mounted on the thread trimming arm, a second thread trimming shaft 92 rotatably supported in the sewing machine base 210, a thread trimming fork crank 93 and a third thread trimming crank 94 respectively fixed to the right and left ends of the second thread trimming shaft 92, and an auxiliary knife frame 95. The second thread trimming roller 91 is slidably mounted in the fork of the thread trimming fork crank 93, the third thread trimming crank 94 is hinged to the auxiliary knife frame 95, and the auxiliary movable knife 52 is fixed on the auxiliary knife frame 95. In particular, the two arms constituting the fork of the wire trimming fork crank 93 are respectively a longer upper long arm and a shorter lower short arm; when the motor shaft of the second driving source 130 operates in the auxiliary knife wire trimming area B1, the second wire trimming roller 91 is in contact with both the upper long arm and the lower short arm of the fork of the wire trimming fork crank 93, and power is transmitted, which can drive the auxiliary movable knife 52 to rotate; when the auxiliary movable knife 52 is reset, the second wire trimming roller 91 slides out along the lower short arm of the fork, realizing the separation of the second wire trimming roller 91 from the fork of the wire trimming fork crank 93, then when the motor shaft of the second driving source 130 operates in the second idle stroke area B4 and the tooth lifting area B2, there is no power transmission between the second wire trimming roller 91 and the wire trimming fork crank 93, and the auxiliary movable knife 52 does not rotate and remains in its initial position. Preferably, a buffer pad is installed on the trimmer fork crank 93, and the auxiliary movable knife 52 is stopped at its initial position through the contact and cooperation between the buffer pad and the sewing machine bottom plate 210.

[0161] Furthermore, if Figure 7 、 Figure 8 a to Figure 8As shown in Figure c, the sewing machine also includes a thread pressing plate 180 fixed to the sewing machine base 210, and an air suction mechanism; the thread pressing plate 180 has a thread pressing head 181; the air suction mechanism includes an air suction power source and an air suction port 190 connected to the air suction power source. The air suction port 190 is adjacent to the engagement position of the first thread cutting blade 513 and the second thread cutting blade 521, and the air suction power source is communicatively connected to the electronic control module. In the above step S31, when the electronic control module controls the first drive source 120 to rotate counterclockwise from the current set initial angle to the end point θ2 of the main knife thread cutting area A2, the electronic control module simultaneously controls the air suction power source to start, turns on the air suction function, and generates negative pressure at the air suction port 190. In the above step S32, when the electronic control module controls the first drive source 120 to run clockwise from the end point θ2 of the main knife thread trimming area A2 to the set value within the main knife thread trimming area A2, the first drive source 120 drives the active knife 51 to move to the bottom of the thread pressing head 181 through the first thread trimming drive member 150 and the first thread trimming transmission unit 80, so that the active knife 51 returns to the thread pressing position, and a clamping cavity is formed between the active knife 51 and the thread pressing head 181. The suture thread end in the hook groove 512 of the active knife 51 is clamped in the clamping cavity, and the suture thread end is just in the negative pressure area of the suction port 190, so that the suture thread end is picked up. In the above step S33, after the active knife 51 and the auxiliary movable knife 52 engage and cut off the suture thread end in the hook groove 512, the cut suture thread end is sucked into the suction port 190, realizing automatic collection of the thread end. Afterwards, the electronic control module controls the air intake power source to be turned off, and the air intake of the air intake port 190 is disconnected.

[0162] In summary, the present application can realize functions such as automatic presser foot lifting, slightly lifting the presser foot at the start of sewing to prevent thread breakage, sinking of the feed dog 20 after lifting the presser foot, automatic thread cutting to prevent bird nests at the start of sewing, automatic thread cutting after sewing, and automatic adjustment of the tooth height. The tooth height can also be automatically adjusted according to the thickness detection of the sewing material, effectively improving the sewing quality. In particular, by separately controlling the first drive source 120 and the second drive source 130, the time for the knife to separate the thread or the time for the knife to hook the thread during thread cutting, the time for cutting the thread, and the cutting position can be precisely controlled, the residual thread on the sewing material is shorter, the range of the sewing thread is wider, the thread cutting sound is lower, and there will be no bird nest thread balls at the start of sewing.

[0163] Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0164] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A sewing machine comprising a thread trimming mechanism (50), wherein the thread trimming mechanism (50) comprises a movable active knife (51) and an auxiliary movable knife (52), wherein: The invention also includes a first driving source (120), a second driving source (130), a first thread trimming driving member (150) driven to rotate by the first driving source (120), and a second thread trimming driving member (170) driven to rotate by the second driving source (130). The thread trimming mechanism (50) also includes a first thread trimming transmission unit (80) connected between the first thread trimming driving member (150) and the active knife (51), and a second thread trimming transmission unit (90) connected between the second thread trimming driving member (170) and the auxiliary movable knife (52). The active knife (51) is provided with a thread dividing groove (511), a thread hooking groove (512) capable of allowing a needle in a sewing machine to pass through, and a first thread trimming blade (513). The auxiliary movable knife (52) is provided with a second thread trimming blade (521). The first thread trimming blade (513) can engage with the second thread trimming blade (521).

2. The sewing machine according to claim 1, characterized in that: The first thread trimming drive member (150) is a thread trimming drive crank, and the first thread trimming transmission unit (80) includes a first thread trimming roller (81) rotatably mounted on the thread trimming drive crank, a thread trimming transmission lever (82) having a fourth fixed fulcrum, a first thread trimming connecting rod (83), a first thread trimming shaft (84) rotatably supported in a sewing machine bottom plate (210), a first thread trimming crank (85) and a second thread trimming crank (86) respectively fixed at two ends of the first thread trimming shaft (84), and a second thread trimming connecting rod (83). A wire connecting rod (87) and a main tool holder (88) are provided. The wire cutting transmission lever (82) is provided with a fork groove portion. The first wire cutting roller (81) is installed in the fork of the fork groove portion in a sliding manner. The two ends of the first wire cutting connecting rod (83) are respectively hinged to the wire cutting transmission lever (82) and the first wire cutting crank (85). The two ends of the second wire cutting connecting rod (87) are respectively hinged to the second wire cutting crank (86) and the main tool holder (88). The active knife (51) is fixed on the main tool holder (88).

3. The sewing machine according to claim 1, wherein: The second thread trimming drive member (170) is provided with a thread trimming arm. The second thread trimming transmission unit (90) comprises a second thread trimming roller (91) rotatably mounted on the thread trimming arm, a second thread trimming shaft (92) rotatably supported in a sewing machine bottom plate (210), a thread trimming fork crank (93) and a third thread trimming crank (94) respectively fixed at two ends of the second thread trimming shaft (92), and an auxiliary knife frame (95). The second thread trimming roller (91) is slidably mounted in the fork of the thread trimming fork crank (93), the third thread trimming crank (94) is hinged to the auxiliary knife frame (95), and the auxiliary movable knife (52) is fixed on the auxiliary knife frame (95).

4. The sewing machine according to claim 1, wherein: The invention also comprises a presser foot assembly (110), a presser foot lifting mechanism (40) connected to the presser foot assembly (110), a presser foot lifting driving member (140), and a presser foot lifting transmission unit (60), wherein the presser foot lifting driving member (140) is driven to rotate by a first driving source (120), and the presser foot lifting transmission unit (60) is connected between the presser foot lifting driving member (140) and the presser foot lifting mechanism (40).

5. The sewing machine according to claim 4, characterized in that: The presser foot lifting mechanism (40) comprises a right lever (41) with a first fixed fulcrum, a presser foot lifting rod (42), a left lever (43) with a second fixed fulcrum, a presser foot lifting plate (44), a transmission guide frame (45), and a presser bar (46) movably mounted in a sewing machine housing (200), the two ends of the presser foot lifting rod (42) being hinged to the right lever (41) and the left lever (43) respectively, the left lever (43) being hinged to the presser foot lifting plate (44), a lifting hook being provided on the presser foot lifting plate (44), a connecting protrusion being engaged with the lifting hook being provided on the transmission guide frame (45), the transmission guide frame (45) being fixed to the upper end of the presser bar (46), and the presser foot assembly (110) being mounted on the lower end of the presser bar (46); The presser foot lifting driving member (140) is a presser foot lifting driving cam, and the presser foot lifting transmission unit (60) includes a presser foot lifting transmission crank (61) with a third fixed fulcrum, a presser foot lifting roller (62) rotatably mounted on one end of the presser foot lifting transmission crank (61), and a presser foot lifting push rod (63), the presser foot lifting roller (62) can contact and cooperate with the presser foot lifting driving cam, and the two ends of the presser foot lifting push rod (63) are respectively hinged to the other end of the presser foot lifting transmission crank (61) and the right lever (41).

6. The sewing machine according to claim 4, characterized in that: The presser foot lifting mechanism (40) comprises a right lever (41) with a first fixed fulcrum, a presser foot lifting rod (42), a left lever (43) with a second fixed fulcrum, a pressure regulating slider (47) rotatably mounted on the left lever (43), a pressure rod (46) movably mounted in a sewing machine housing (200), a pressure regulating sleeve (48) movably mounted on the pressure rod (46), and a pressure regulating spring (49) mounted on the pressure rod (46). ), and an upper guide frame (410) and a lower guide frame (411) both fixed on the pressure rod (46); a pressure regulating slide sleeve (48) is provided with a pressure regulating groove that slides with the pressure regulating slider (47); the upper and lower ends of the pressure regulating spring (49) are respectively in contact with the pressure regulating slide sleeve (48) and the lower guide frame (411); the pressure regulating slide sleeve (48) can be in contact with the upper guide frame (410); and the presser foot assembly (110) is installed at the lower end of the pressure rod (46); The presser foot lifting driving member (140) is a presser foot lifting driving crank, and the presser foot lifting transmission unit (60) includes a presser foot lifting transmission connecting rod (64), a presser foot lifting transmission crank (61) having a third fixed fulcrum, and a presser foot lifting push rod (63), the two ends of the presser foot lifting transmission connecting rod (64) are respectively hinged to the presser foot lifting driving crank and one end of the presser foot lifting transmission crank (61), and the two ends of the presser foot lifting push rod (63) are respectively hinged to the other end of the presser foot lifting transmission crank (61) and the right lever (41).

7. The sewing machine according to claim 1, characterized in that: The invention also includes a tooth frame (10), a feed tooth (20) mounted on the tooth frame (10), a tooth lifting mechanism (30) connected to one end of the tooth frame (10), a tooth lifting driving member (160), and a tooth lifting transmission unit (70), wherein the tooth lifting driving member (160) is driven to rotate by a second driving source (130), and the tooth lifting transmission unit (70) is connected between the tooth lifting driving member (160) and the tooth lifting mechanism (30).

8. The sewing machine according to claim 7, characterized in that: The tooth lifting drive member (160) and the second thread cutting drive member (170) are combined into a tooth lifting and thread cutting drive crank.

9. The sewing machine according to claim 7 or 8, characterized in that: The tooth-lifting driving member (160) is provided with a tooth-lifting arm portion, and the tooth-lifting mechanism (30) includes a tooth-lifting shaft (31) rotatably supported in the sewing machine bottom plate (210), a first tooth-lifting crank (32) fixed at one end of the tooth-lifting shaft (31), and a first tooth-lifting connecting rod (33), the two ends of the first tooth-lifting connecting rod (33) are respectively hinged to the first tooth-lifting crank (32) and the tooth frame (10); the tooth-lifting transmission unit (70) includes a second tooth-lifting connecting rod (71) and a second tooth-lifting crank (72) fixed at the other end of the tooth-lifting shaft (31), the two ends of the second tooth-lifting connecting rod (71) are respectively hinged to the tooth-lifting arm portion and the second tooth-lifting crank (72).

10. The sewing machine according to claim 1, wherein: The invention also includes a thread pressing plate (180) fixed to a sewing machine bottom plate (210), wherein the thread pressing plate (180) has a thread pressing head (181); when the sewing machine is cutting the thread and starting to sew, the first driving source (120) drives the active knife (51) to move to the bottom of the thread pressing head (181) through the first thread cutting driving member (150) and the first thread cutting transmission unit (80), and a thread clamping cavity is formed between the active knife (51) and the thread pressing head (181).

11. The sewing machine according to claim 1, wherein: The first driving source (120) and the second driving source (130) are both motors, the first thread trimming driving component (150) is fixed on the motor shaft of the first driving source (120), and the second thread trimming driving component (170) is fixed on the motor shaft of the second driving source (130).

12. A sewing machine control method, characterized in that: Using the sewing machine according to claim 1, the sewing machine control method comprises the following steps: S1. Configuring an electric control module so that the first driving source (120) and the second driving source (130) are both communicatively connected to the electric control module; The working area of the first driving source (120) has a main knife thread cutting area (A2), and the working area of the second driving source (130) has an auxiliary knife thread cutting area (B1); S2, after the sewing machine is powered on and started, the electric control module controls the first driving source (120) to operate to a working area other than the main knife thread cutting area (A2), and controls the second driving source (130) to operate to a working area other than the auxiliary knife thread cutting area (B1), the active knife (51) is in its retracted position, and the auxiliary movable knife (52) is in its retracted position; S3: After the electronic control module receives the sewing start signal, the sewing machine starts to operate: When the needle in the sewing machine moves downward and is located above the needle plate, the electric control module controls the first driving source (120) to move to the main knife thread cutting area (A2), drives the active knife (51) to cut out, and makes the thread hooking groove (512) located directly below the needle; The sewing machine continues to operate, and when the needle pierces the fabric and moves upward to above the needle plate, the electric control module controls the first driving source (120) to reversely operate to the set value in the main knife thread cutting area (A2), driving the active knife (51) to return the knife, and the thread end of the sewing thread is in the thread hook groove (512) of the active knife (51); The sewing machine continues to operate. When the electronic control module determines that the feed dog (20) in the sewing machine moves to the lower side of the upper surface of the needle plate, the electronic control module controls the second driving source (130) to operate to the auxiliary knife thread cutting area (B1), drives the auxiliary movable knife (52) to cut out, and the first thread cutting blade (513) and the second thread cutting blade (521) engage to cut the thread end of the sewing thread in the thread hooking groove (512); The electric control module controls the first driving source (120) to reset, and controls the second driving source (130) to reset.

13. The sewing machine control method according to claim 12, wherein: The sewing machine further comprises a tooth frame (10), a feed tooth (20) mounted on the tooth frame (10), a tooth lifting mechanism (30) connected to one end of the tooth frame (10), a presser foot assembly (110), a presser foot lifting mechanism (40) connected to the presser foot assembly (110), a presser foot lifting driving member (140) driven to rotate by a first driving source (120), a tooth lifting driving member (160) driven to rotate by a second driving source (130), a presser foot lifting transmission unit (60), and a tooth lifting transmission unit (70), wherein the presser foot lifting transmission unit (60) is connected between the presser foot lifting driving member (140) and the presser foot lifting mechanism (40), and the tooth lifting transmission unit (70) is connected between the tooth lifting driving member (160) and the tooth lifting mechanism (30), and the presser foot lifting mechanism (40) does not have a presser foot pressure regulating function; In step S1, the working area of the first driving source (120) further includes a first idle stroke area (A1) and a presser foot lifting area (A3), the main knife thread cutting area (A2) and the presser foot lifting area (A3) are distributed on both sides of the first idle stroke area (A1), and the first idle stroke area (A1), the main knife thread cutting area (A2) and the presser foot lifting area (A3) are three independent working areas; the working area of the second driving source (130) further includes a tooth lifting area (B2) independent of the auxiliary knife thread cutting area (B1), and the tooth lifting area (B2) has a lower supply area (B3); In step S2, the electric control module controls the first driving source (120) to operate to the first idle travel area (A1), and controls the second driving source (130) to operate to the tooth lifting area (B2); In step S3, when the second driving source (130) moves into the lower feed area (B3), the electronic control module determines that the feed dog (20) in the sewing machine moves to below the upper surface of the needle plate.

14. The sewing machine control method according to claim 12, wherein: The sewing machine further comprises a tooth frame (10), a feed tooth (20) mounted on the tooth frame (10), a tooth lifting mechanism (30) connected to one end of the tooth frame (10), a presser foot assembly (110), a presser foot lifting mechanism (40) connected to the presser foot assembly (110), a presser foot lifting driving member (140) driven to rotate by a first driving source (120), a tooth lifting driving member (160) driven to rotate by a second driving source (130), a presser foot lifting transmission unit (60), and a tooth lifting transmission unit (70), wherein the presser foot lifting transmission unit (60) is connected between the presser foot lifting driving member (140) and the presser foot lifting mechanism (40), and the tooth lifting transmission unit (70) is connected between the tooth lifting driving member (160) and the tooth lifting mechanism (30), and the presser foot lifting mechanism (40) has a presser foot pressure regulating function; In step S1, the working area of the first driving source (120) further includes a presser foot pressure area (A4) and a presser foot lifting area (A3), the main knife thread cutting area (A2) and the presser foot lifting area (A3) are distributed on both sides of the presser foot pressure area (A4), and the presser foot pressure area (A4), the main knife thread cutting area (A2) and the presser foot lifting area (A3) are three independent working areas; the working area of the second driving source (130) further includes a tooth lifting area (B2) independent of the auxiliary knife thread cutting area (B1), and the tooth lifting area (B2) has a lower supply area (B3); In step S2, the electric control module controls the first driving source (120) to operate to the presser foot pressure area (A4), and controls the second driving source (130) to operate to the tooth lifting area (B2); In step S3, when the second driving source (130) moves into the lower feed area (B3), the electronic control module determines that the feed dog (20) in the sewing machine moves to below the upper surface of the needle plate.

15. The sewing machine control method according to claim 13 or 14, characterized in that: The method further includes step S4: after the electric control module receives the presser foot lifting signal, the electric control module controls the first driving source (120) to move to the presser foot lifting area (A3) to drive the presser foot assembly (110) to move upward; After the presser foot is lifted, the electric control module controls the first driving source (120) to reset.

16. The sewing machine control method according to claim 15, wherein: In step S4, after the presser foot assembly (110) moves upward, the electric control module also controls the second driving source (130) to move to the lower supply area (B3), driving the feed dog (20) to sink below the upper surface of the needle plate; after the presser foot is lifted, the electric control module also controls the second driving source (130) to reset.

17. The sewing machine control method according to claim 13 or 14, characterized in that: The method further includes step S5: after the electric control module receives the thread trimming signal, the electric control module controls the first driving source (120) to move to the main knife thread trimming area (A2), drives the active knife (51) to cut out, and the thread dividing groove (511) of the active knife (51) is separated; thereafter, the electric control module controls the first driving source (120) to move in the reverse direction to the set value in the main knife thread trimming area (A2), drives the active knife (51) to return, and the thread is contained in the thread dividing groove (511) of the active knife (51); the electric control module controls the second driving source (130) to move to the auxiliary knife thread trimming area (B1), drives the auxiliary movable knife (52) to cut out, and the first thread cutting blade (513) and the second thread cutting blade (521) are engaged to cut the thread in the thread dividing groove (511); the electric control module controls the first driving source (120) to reset, and controls the second driving source (130) to reset.

18. The sewing machine control method according to claim 12, wherein: The sewing machine is further provided with an air suction mechanism, the air suction mechanism comprising an air suction power source and an air suction port (190) in communication with the air suction power source, the air suction port (190) being adjacent to the engagement position of the first thread cutting blade (513) and the second thread cutting blade (521), and the air suction power source being in communication with the electric control module; In step S3, when the electronic control module controls the first driving source (120) to move to the main knife thread cutting area (A2) so that the thread hooking groove (512) is located directly below the machine needle, the electronic control module simultaneously controls the suction power source to start, so that negative pressure is generated at the suction port (190); after the active knife (51) and the auxiliary movable knife (52) cut the suture thread ends in the thread hooking groove (512), the cut suture thread ends are sucked into the suction port (190); thereafter, the electronic control module controls the suction power source to shut down.

19. The sewing machine control method according to claim 12, wherein: The engagement position of the first thread cutting blade (513) and the second thread cutting blade (521) is adjacent to the machine needle.

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