A sewing machine

Abstract

The present application belongs to sewing technical field, more particularly to a sewing machine, including frame, and the stitch length adjusting mechanism, the thread trimming mechanism and the presser foot lifting mechanism arranged on the frame, the lower part of the frame is provided with motor, the first output shaft of motor is used to drive the swing seat of the stitch length adjusting mechanism, one side of the swing seat is provided with first support shaft, one end of first support shaft drives the swing seat to swing within the set angle, the other end of first support shaft extends towards the position of motor and is installed with first knob, the first knob is provided with first sliding slot, the first output shaft is installed with first crank, the first crank is installed with sliding block, the sliding block slides in the first sliding slot, so that the overall structure is more compact, in addition, the area of the lower part of the frame can be better utilized.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewing technology field, in particular to a sewing machine. BACKGROUND

[0002] The existing sewing machine is a machine for sewing materials by sewing thread. The sewing machine includes needle bar mechanism, thread tension mechanism, feeding mechanism, thread hooking mechanism, pressing mechanism, presser foot lifting mechanism, stitch length adjusting mechanism, thread cutting mechanism, etc. With the development of automation, these mechanisms are gradually improved and configured with driving members, including motors, electromagnets, air cylinders and oil cylinders, etc. When the stitch length adjusting mechanism adjusts the stitch length to a negative value, the sewing machine realizes reverse sewing.

[0003] In the existing design, the driving of the motor to the stitch length adjusting mechanism is usually achieved by rotating the cam to adjust the stitch length adjusting mechanism. For example, in Chinese patent application No. 202011225730.3, a driving device for thread cutting, presser foot lifting and stitch length adjusting, the stitch length adjusting cam is a curved quadrilateral, the stitch length adjusting mechanism abuts against the outer wall of the stitch length adjusting cam, and by swinging the stitch length adjusting roller on the top rod to abut against and contact different surfaces of the curved quadrilateral, the sewing machine adjusts the stitch length under different movements.

[0004] One motor simultaneously drives the thread cutting mechanism, the presser foot lifting mechanism and the stitch length adjusting mechanism, which essentially divides the rotation angle of the motor shaft. Within the 360° rotation range, three angles corresponding to the thread cutting mechanism, the presser foot lifting mechanism and the stitch length adjusting mechanism are reasonably divided. Under normal circumstances, the motor shaft is in the stitch length adjusting area, when thread cutting or presser foot lifting is needed, the corresponding thread cutting area or presser foot lifting area is entered, and after the execution is completed, it returns to the stitch length adjusting area.

[0005] The disadvantages of the prior art are that when the curved quadrilateral rotates, it is easy to collide with the stitch length adjusting roller and cause damage, and the movement between the two is unstable, the overall structure is complex and not compact. SUMMARY

[0006] The purpose of the present application is to provide a sewing machine with more concentrated transmission, lower cost and two or three actions realized by one motor.

[0007] The purpose of the present application is achieved as follows:

[0008] A sewing machine, comprising a frame, a thread cutting mechanism, a presser foot lifting mechanism and a stitch length adjusting mechanism, the lower part of the frame is provided with a motor,

[0009] The second output shaft of the motor extends forward and drives the thread cutting mechanism,

[0010] The first output shaft of the motor extends backward and drives the presser foot lifting mechanism and the stitch length adjusting mechanism,

[0011] The first output shaft is provided with a first crank, and the first crank drives the needle spacing adjustment mechanism;

[0012] The swing base of the needle spacing adjustment mechanism is provided with a first supporting shaft, and the first supporting shaft drives the swing base to swing within a set angle; one end of the first supporting shaft, which faces the motor, is provided with a first actuating member, the first actuating member is provided with a first sliding slot, and the first sliding slot is provided with a sliding block; and the outer end of the first crank is provided with the sliding block.

[0013] Preferably, the first output shaft is provided with a first cam, and the first cam drives the presser foot lifting mechanism.

[0014] The rack is rotatably provided with a double swing lever, and the double swing lever has a first swing arm and a second swing arm; the swing arm end of the first swing arm is hingedly provided with a presser foot lifting link, and the swing arm end of the second swing arm abuts against the first cam.

[0015] Preferably, the double swing lever is arranged below the first actuating member, and the first actuating member is located between the first swing arm and the second swing arm of the double swing lever.

[0016] Preferably, the swing arm end of the second swing arm of the double swing lever is hingedly provided with a roller, and the roller abuts against the wheel surface of the first cam.

[0017] Preferably, the other side of the swing base is provided with a second supporting shaft; the first supporting shaft and the second supporting shaft are arranged on the same axis and respectively extend into the two side portions of the swing base.

[0018] The first supporting shaft is further provided with a second actuating member, and the second actuating member is provided with a second sliding slot.

[0019] The side portion of the swing base, which is adjacent to the first supporting shaft, is provided with an actuating pin, and the actuating pin is arranged in the second sliding slot.

[0020] Preferably, the second output shaft is provided with a second crank, and the second crank is provided with a second cam, and the second cam drives the thread trimming mechanism.

[0021] The second cam is provided with a through hole, one end of the second crank is arranged in the through hole, and the working surface of the second cam is the inner wall of the through hole.

[0022] Preferably, the first cam comprises a rotating end and a protruding end, the rotating end is connected with the first output shaft, and the protruding end is used for actuating the second swing arm.

[0023] The first cam has a working surface and a non-working surface, the working surface is the peripheral surface of the protruding end, and the non-working surface is the peripheral surface of the rotating end.

[0024] Preferably, the motor is laterally arranged at the lower side of the middle portion of the frame.

[0025] Preferably, a rotation axis is provided on the double rocker arm, and the double rocker arm rotates around the rotation axis;

[0026] A return spring for returning the presser foot is arranged on the rotating shaft, one end of the return spring is arranged on the frame, and the other end is arranged on the double rocker arm.

[0027] Preferably, a trimming assembly is provided at the front end of the frame, and the trimming assembly includes

[0028] A bearing seat, which is arranged on the sewing machine body;

[0029] A driving motor is mounted on the bearing base and is used to provide power;

[0030] The trimming assembly is arranged on a bearing seat and can be raised and lowered vertically;

[0031] The crank-connecting rod assembly is arranged in the bearing seat, one end of which is a power input end and the other end is a power output end; the power input end is connected to the motor shaft of the drive motor, and the power output end is connected to the trimming assembly;

[0032] The tool holder guide frame is arranged in the bearing seat and has a vertical slide groove; the power output end is provided with a slider, the slider is located in the slide groove, and the slider is connected to the guide column of the trimming assembly; the crank connecting rod assembly converts the rotation of the motor shaft into the vertical lifting of the trimming assembly.

[0033] Preferably, the crank-connecting rod assembly includes a crank sleeve connecting rod and a guide column; the crank sleeve is passed through the motor shaft, the swinging end of the crank sleeve is hinged to the upper end of the connecting rod, the lower end of the connecting rod is mounted on the guide column, one end of the guide column is fixedly connected to the upper end of the trimming assembly, and the other end of the guide column is connected to the slider.

[0034] Preferably, the trimming assembly is provided with a knife bar and a knife holder; the knife holder includes a fixed bracket and an adjustment bracket; the fixed bracket is mounted on the lower end of the knife bar, and the top end of the adjustment bracket is formed with a groove adapted to the fixed bracket, and the adjustment bracket is assembled on the fixed bracket through the groove;

[0035] An adjusting groove is provided on the surface of the adjusting bracket, and a bolt passes through the adjusting groove to screw the fixing bracket and the adjusting bracket into one piece;

[0036] A cutter is installed at the lower part of the adjusting bracket.

[0037] Preferably, the lower part of the frame is further provided with a knee rest assembly, which comprises: a sensor for obtaining a trigger signal; a sensing part for triggering the sensor; a knee rest execution part for driving the sensing part to move along a set trajectory; a knee rest driving part for driving the knee rest execution part; a connecting frame for being fixed on an adapted sewing machine and directly or indirectly bearing the remaining parts; the knee rest execution part comprises a rotating rod and a mounting sleeve; the rotating rod comprises a rotating part, a swing part and a limiting part; the rotating part, the swing part and the limiting part are integrally formed; the rotating part is rotatably mounted on the connecting frame; one end of the rotating part extends out of the connecting frame and is connected with the knee rest driving part; the swing part is arranged at the other end of the rotating part and is bent to one side; the limiting part is arranged at the swing end of the swing part and is bent to the other side; the end of the limiting part extends into the waist-shaped hole of the connecting frame; the mounting sleeve is arranged on the swing part or the limiting part, and the sensing part is arranged on the mounting sleeve.

[0038] According to an embodiment of the present application, the mounting sleeve is provided with a mounting groove fixing part, a fixing cap part and a side leaning part; the mounting sleeve is arranged at the corner where the swing part and the limiting part are connected; the fixing cap part is sleeved on the limiting part; the side leaning part leans against the swing part; the side leaning part is provided with a fixing hole, and is fixed to the swing part through a screw passing through the fixing hole; the mounting sleeve is a plastic part.

[0039] The present application has the following prominent and beneficial technical effects compared with the prior art:

[0040] 1、The first sliding groove can limit the movement of the sliding block at all times when the motor drives the first crank to rotate and further drives the needle pitch adjusting assembly, so that the sliding block can only move linearly back and forth along the extension direction of the first sliding groove, and the first crank can rotate more stably when driving the first driving part to rotate, and the first driving part can also move more stably when driving the needle pitch adjusting assembly to move, thereby reducing the error rate of the needle pitch adjusting assembly and improving the yield of the product; during the rotation of the first crank by 360°, the sliding block always slides in the first sliding groove, so that the working angle of the motor shaft can be divided into a cutting area and a presser foot lifting area in sequence; when only the presser foot needs to be lifted and the thread needs not to be cut, the motor shaft enters the presser foot lifting area but not the cutting area; when the thread needs to be cut and the presser foot needs to be lifted, the motor shaft rotates in the opposite direction, enters the cutting area and further enters the presser foot lifting area, and the motor shaft can rotate by 360° and return to the set needle pitch position without repeated forward and reverse rotation, which is beneficial to the response of the motor and prolongs the service life.

[0041] 2. The first support shaft and the first output shaft of the present invention are arranged up and down in the vertical plane and front and back in the horizontal plane; the first shifting member is arranged downward, so that the working area of ​​the first shifting member forms a fan-shaped area with a certain angle of deflection; the working area of ​​the first crank is a circular area within the fan-shaped area, so that the overall structure is more compact; in addition, the area at the bottom of the frame can be better utilized.

[0042] 3. The double-linked rocker arm of the present invention is positioned below the first toggle member, which is located between the first and second rocker arms of the double-linked rocker arm. The fan-shaped area formed by the first toggle member's angular deflection does not interfere with the double-linked rocker arm, compacting multiple components and reducing the installation space to a smaller area, thereby saving overall installation space. Furthermore, the system is adaptable to existing structures such as the presser foot lifter linkage, eliminating the need for extensive adjustments.

[0043] 4. The double rocker of the present invention, driven by the protruding end of the first cam, tilts the double rocker to a certain angle, allowing the presser foot to be raised or lowered, and the return spring to be tightened. When the non-working surface (i.e., the rotating end) of the double rocker contacts the roller, the return spring resets itself, simultaneously driving the double rocker to reset, ultimately resetting the presser foot. This simple and effective reset mechanism ensures a simple and effective reset.

[0044] 5. The trimming assembly of the present invention is provided with a separate driving motor, and no longer requires the motor drive of the sewing machine. When the angle of the fabric is rotated, the trimming assembly can still perform the trimming action.

[0045] 6. The knee support assembly of the present invention is provided with a rotating rod and a mounting sleeve. The sensed part is arranged on the mounting sleeve. The rotating rod is an integrally formed design, which not only avoids signal interference with the sensor, but also simplifies the structure of the rotating rod and improves the strength of the rotating rod, avoids loosening, and increases the service life of the assembly; further, due to the simplified structure, the difficulty of installing the assembly is reduced, the installation accuracy is improved, and the processing cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Schematic diagram of the overall structure of a sewing machine.

[0047] Figure 2 This is a schematic diagram of the structure of the thread trimming, presser foot lifting and stitch length adjustment mechanisms.

[0048] Figure 3 It is a partial structural diagram of the presser foot lifting and needle length adjustment mechanism.

[0049] Figure 4 Schematic diagram of the connection structure between the second cam and the second crank.

[0050] Figure 5 Schematic diagram of the motor's rotation angle division.

[0051] Figure 6 is a structural diagram of a knee rest assembly.

[0052] Figure 7 is an exploded structural diagram of a knee rest assembly.

[0053] Figure 8 is a structural diagram of a knee rest assembly.

[0054] Figure 9 is a structural diagram of a knee rest assembly.

[0055] Figure 10 is a sectional structural diagram of a knee rest assembly.

[0056] Figure 11 is a structural diagram of a mounting sleeve of a knee rest assembly.

[0057] Figure 12 is a structural diagram of a mounting sleeve of a knee rest assembly.

[0058] Figure 13 is one of structural diagrams of a trimming assembly.

[0059] Figure 14 is another of structural diagrams of a trimming assembly.

[0060] Figure 15 is an exploded diagram of a trimming assembly.

[0061] Figure 16 is a structural diagram of a trimming assembly after being assembled with a sewing machine body.

[0062] Figure 17 is Figure 16 is an enlarged view of A in FIG. 4.

[0063] Figure 18 is a sectional view of a trimming assembly after being assembled with a sewing machine body.

[0064] Reference signs: 1, frame; 2, thread cutting mechanism; 3, presser foot lifting mechanism; 4, stitch length adjusting mechanism; 5, motor; 6, second output shaft; 7, first output shaft; 8, first crank; 9, swing base; 10, first support shaft; 11, first actuating member; 12, first sliding groove; 13, sliding block; 14, first cam; 15, double swing lever; 16, first swing arm; 17, second swing arm; 18, roller; 19, second support shaft; 20, second actuating member; 21, second sliding groove; 22, actuating pin; 23, second crank; 24, second cam; 25, through hole; 26, rotating end; 27, protruding end; 28, rotating shaft; 29, return spring; 30, rolling wheel; 31, thread cutting shaft; 32, thread cutting crank;

[0065] a1 -pitch adjustment area; a2 - thread trimming area; a3 - presser foot lifting area;

[0066] a100, knee rest driving component; a200, knee rest driven component; a10, knee rest plate; a20, connecting rod; a30, rotating block; a40, rotating rod; a50, connecting frame; a60, cover; a70, sensor; a80, sensed component; a90, mounting sleeve;

[0067] a41, rotating part; a42, swinging part; a43, limiting part; a44, circlip groove; a51, mounting hole; a52, waist-shaped hole; a53, side plate; a54, bottom plate; a91, mounting groove part; a92, fixing cap part; a93, side leaning part; a94, fixing hole; a110, circlip; a120, limiting sleeve; a130, torsion spring; a140, shaft sleeve; a150, rubber sleeve;

[0068] b1, bearing seat; b11, tool holder guide frame; b12, sliding groove; b13, sliding block; b14, cover; b15, sleeve; b16, assembly hole; b2, edge trimming assembly; b20, tool bar; b21, guide post; b22, tool holder; b221, adjusting support; b222, fixing support; b23, groove; b24, adjusting groove; b25, cutter; b26, U-shaped groove; b27, adjusting bolt; b28, gasket; b29, adjusting threaded hole; b3, driving motor; b31, motor shaft; b32, crank connecting rod assembly; b33, crank shaft sleeve; b34, connecting rod; b4, sewing machine housing; b41, thread stabbing mechanism; b42, stabbing needle; b43, needle bar; b44, presser foot lifting mechanism; b45, presser foot; b46, presser foot lifting rod; b47, needle plate; b48, tungsten steel sheet; b100, upper shaft motor of sewing machine. DETAILED DESCRIPTION

[0069] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0070] As shown in Figure 1 , a sewing machine comprises thread trimming, presser foot lifting and pitch adjustment mechanisms. As shown in Figure 2 , the thread trimming, presser foot lifting and pitch adjustment mechanisms comprise a frame 1, on which a thread trimming mechanism 2, a presser foot lifting mechanism 3 and a pitch adjustment mechanism 4 are arranged; the lower part of the frame 1 is further provided with a motor 5. Among them, the second output shaft 6 of the motor 5 extends forward and drives the thread trimming mechanism 2, and the first output shaft 7 of the motor 5 extends backward and drives the presser foot lifting mechanism 3 and the pitch adjustment mechanism 4. Thus, the synchronous driving of the thread trimming mechanism 2, the presser foot lifting mechanism 3 and the pitch adjustment mechanism 4 is realized through the motor 5 and the two output shafts.

[0071] In particular, in combination with Figure 2 ,Figure 3 The first output shaft 7 is provided with a first crank 8, and the first crank 8 drives the needle spacing adjustment mechanism 4 to move. The swing seat 9 of the needle spacing adjustment mechanism 4 is provided with a first supporting shaft 10 on one side, and the first supporting shaft 10 drives the swing seat 9 to swing within a set angle. The end of the first supporting shaft 10 facing the motor is provided with a first driving piece 11, and the first driving piece 11 is provided with a first sliding groove 12. The first sliding groove 12 is provided with a sliding block 13, and the outer end of the first crank 8 is provided with the sliding block 13.

[0072] Therefore, through the design of the sliding groove and the sliding block 13, the motor drives the first driving piece 11 to rotate through the first crank 8, and then drives the needle spacing adjustment assembly to move. The inner wall of the first sliding groove 12 can always limit the movement of the sliding block 13, so that the sliding block 13 can only move linearly along the extension direction of the first sliding groove 12. Therefore, the first crank 8 can drive the first driving piece 11 to rotate more stably, and the first driving piece 11 can drive the needle spacing adjustment assembly to move more stably. Finally, the error rate of the needle spacing adjustment assembly is reduced, and the yield of the product is improved.

[0073] In combination with Figure 2 and Figure 3 , the first output shaft 7 is provided with a first cam 14, and the first cam 14 drives the presser foot mechanism 3. Specifically, the frame 1 is rotatably provided with a double swing rod 15, and the double swing rod 15 has a first swing arm 16 and a second swing arm 17. The swing arm end of the first swing arm 16 is hingedly provided with a presser foot connecting rod, and the swing arm end of the second swing arm 17 abuts against the first cam 14. Therefore, the motor 5 drives the first cam 14 to rotate, and then the first cam 14 drives the second swing arm 17 to move. The second swing arm 17 drives the first swing arm 16 to move through the main body of the middle part of the double swing rod 15. Finally, the first swing arm 16 drives the presser foot mechanism 3 to move.

[0074] In combination with Figure 1 , Figure 2 and Figure 3 , the double swing rod 15 is arranged below the first driving piece 11, and the first driving piece 11 is located between the first swing arm 16 and the second swing arm 17 of the double swing rod 15. Therefore, multiple components can be arranged without interfering with each other, and multiple components can be as compact as possible, so as to shrink the installation space to a smaller range, thereby saving the overall installation space.

[0075] In combination with Figure 1 and Figure 3The double pendulum lever 15 is provided with a rotating shaft 28, and the double pendulum lever 15 rotates around the rotating shaft 28. The rotating shaft 28 is provided with a reset spring 29 for resetting the presser foot. One end of the reset spring 29 is arranged on the frame 1, and the other end is arranged on the double pendulum lever 15. When the double pendulum lever 15 is tilted by a certain angle by the protruding end 27 of the first cam 14, the presser foot can be lifted or lowered, and the reset spring 29 can also be tightened. When the non-working surface, i.e. the rotating end 26 of the double pendulum lever 15, is in contact with the roller 18, the reset spring 29 resets itself and drives the double pendulum lever 15 to reset, and finally, the presser foot is reset. The reset structure is simple and effective.

[0076] As shown in Figure 3 , the second swing arm 17 of the double pendulum lever 15 is hinged with a roller 18, and the roller 18 abuts against the wheel surface of the first cam 14. Thus, through the roller 18, part of the friction force between the second swing arm 17 and the first cam 14 is converted into the action force of the rotation of the roller 18, and then the movement between the second swing arm 17 and the second cam 24 is smoother, and the friction force when they touch together is reduced, and the damage caused by scratching is reduced.

[0077] Among them, in combination with Figure 2 and Figure 3 , the first cam 14 includes a rotating end 26 and a protruding end 27. The rotating end 26 is connected with the first output shaft 7, so that the motor 5 drives the first cam 14. The protruding end 27 protrudes outward to drive the second swing arm 17, so as to realize the movement of the presser foot lifting mechanism 3. The first cam 14 has a working surface and a non-working surface. The working surface is the peripheral surface of the protruding end 27, and the non-working surface is the peripheral surface of the rotating end 26. The diameters of the rotating end 26 and the protruding end 27 are different. When the first cam 14 rotates, the non-working surface of the first cam 14 is in contact with the roller 18, and the double pendulum lever 15 remains fixed and does not swing. When the working surface is in contact with the roller 18, the protruding end 27 pushes away the roller 18, drives the double pendulum lever 15 to swing, and drives the presser foot lifting mechanism 3 to move.

[0078] As shown in Figure 3As shown, the other side of the swing seat 9 is provided with a second support shaft 19, the first support shaft 10 and the second support shaft 19 are provided with the same axis, and respectively extend into the two side portions of the swing seat 9, so as to stabilize the two ends of the swing seat 9 through the first support shaft 10 and the second support shaft 19. The first support shaft 10 is further provided with a second shifting piece 20, and the second shifting piece 20 is provided with a second sliding groove 21; the side portion of the swing seat 9 close to the first support shaft 10 is provided with a shifting pin 22, and the shifting pin 22 is arranged in the second sliding groove 21. Further, the stable sliding of the shifting pin 22 in the second sliding groove 21 can make the second shifting piece 20 shift the needle spacing adjusting mechanism 4 assembly more stably. The first support shaft 10 supports the swing seat 9, and also drives the swing seat 9 through the shifting pin 22.

[0079] In combination Figure 2 With Figure 4 , the second output shaft 6 is installed with a second crank 23, the second crank 23 is provided with a second cam 24, the second cam 24 drives the line cutting mechanism 2, the second cam 24 is provided with a through hole 25, one end of the second crank 23 is arranged in the through hole 25, and the working surface of the second cam 24 is the inner wall of the through hole 25. In the second crank 23 of the embodiment, the part arranged in the through hole 25 is a rolling wheel 30, and the second crank 23 rolls on the working surface of the second cam 24 through the rolling wheel 30 after rotating, drives the second cam 24 to rotate, and the second cam 24 drives the line cutting mechanism 2. Therefore, the movement of the rolling wheel 30 is limited by the inner wall of the through hole 25, so that the rolling wheel 30 drives the second cam 24 on the inner side of the second cam 24, prevents the rolling wheel 30 from separating from the second cam 24, and makes the movement between the second cam 24 and the second crank 23 more stable.

[0080] As Figure 1 shown, in the embodiment, the motor 5 is preferably horizontally arranged at the lower side of the middle portion of the rack 1, so that the components on both sides of the motor 5 can have almost equal installation space, so that the line cutting mechanism 2, the presser lifting mechanism 3 and the needle spacing adjusting mechanism 4 and other components can more reasonably utilize the installation space in the rack 1.

[0081] The lower part of the frame of the present application is further provided with a knee rest assembly, which comprises: a sensor a70 for obtaining a trigger signal; an inductive element a80 for triggering the sensor a70; a knee rest execution component a100 for driving the inductive element a80 to move along a set trajectory; a knee rest driving component a200 for driving the knee rest execution component a100; a connecting frame a50 for being fixed on an adapted sewing machine and directly or indirectly bearing the remaining components; the knee rest execution component a100 comprises a rotating rod a40 and a mounting sleeve a90; the rotating rod a40 comprises: a rotating part a41, a swing part a42 and a limiting part a43; the rotating part a41, the swing part a42 and the limiting part a43 are integrally formed; the rotating part a41 is rotatably mounted on the connecting frame a50; one end of the rotating part a41 protrudes out of the connecting frame a50 and is connected with the knee rest driving component a200 (see Figure 6 ); the swing part a42 is arranged at the other end of the rotating part a41 and is bent to one side; the limiting part a43 is arranged at the swing end of the swing part a42 and is bent to the other side; the end of the limiting part a43 protrudes into the waist-shaped hole a52 of the connecting frame a50; the mounting sleeve a90 is arranged on the swing part a42 or the limiting part a43; the inductive element a80 is arranged on the mounting sleeve a90.

[0082] The rotating rod a40 is integrally formed, which avoids signal interference to the inductor, simplifies the structure of the rotating rod, improves the strength of the rotating rod, avoids loosening during rotation, improves the service life of the assembly, further simplifies the structure, reduces the installation difficulty of the assembly, improves the installation precision, and reduces the processing cost.

[0083] According to an embodiment of the present application, referring to Figure 8 , Figure 10 and Figure 11 and Figure 12 , the mounting sleeve a90 is provided with a mounting groove fixing part a91, a fixing cap part a92 and a side leaning part a93; referring to Figure 8 and Figure 10 , the mounting sleeve is arranged at the corner connecting the swing part a42 and the limiting part a43; the fixing cap part a92 is sleeved on the limiting part a43; the fixing cap part a92 covers the upper side, the front side and the rear side of the limiting part a43. That is to say, the structure of the fixing cap part a92 limits the four degrees of freedom between the mounting sleeve a90 and the rotating rod a40, i.e. limits the three degrees of rotation freedom and one degree of movement freedom in the three directions of the right-angle coordinate axis between the mounting sleeve a90 and the rotating rod.

[0084] Further, the side leaning part a93 is attached to the swing part a42; the side leaning part a93 is provided with a fixing hole a94, which is fixed to the swing part a42 through a screw; the mounting sleeve a90 is a plastic part. As shown inFigure 8 Only one screw is needed to fix the mounting sleeve a90 on the swing part a42, that is, the structure of the side-lying part a93, the fixing hole a94 cooperates with the fixing cap part a92, so that the position between the mounting sleeve a90 and the rotating rod a40 is completely fixed, and the mounting sleeve a90 and the rotating rod a40 are convenient to mount and stable to connect.

[0085] Further, the knee-lying assembly is used to trigger the down signal or the up signal of the pressure foot lifting mechanism, referring to Figure 6 The knee-lying driving part a200 includes a knee-lying disc a10, a connecting rod a20 and a rotating block a30; the knee-lying disc a10 is in a plate structure; one end of the connecting rod a20 is connected with the knee-lying disc a10; the rotating block a30 is connected with the other end of the connecting rod a20; the rotating rod a40 is connected with the rotating block a30 and is arranged perpendicularly to the connecting rod a20; the rotation of the knee-lying disc a10 can sequentially make the connecting rod a20, the rotating block a30 and the rotating rod a40 rotate, and drive the inductive element a80 to trigger the sensing signal of the sensor a70.

[0086] Further, referring to Figure 7 , 8 and Figure 10 , the limiting part a43 and the waist-shaped hole a52 are provided with a rubber sleeve a150, and the limiting part a43 passes through the rubber sleeve a150 to contact the waist-shaped hole a52. During the rotation of the rotating rod a40, the limiting part a43 swings to make flexible contact with the waist-shaped hole a52 of the connecting frame a50, so as to reduce the impact force and impact vibration, make the movement track of the inductive element a80 more stable, improve the signal accuracy of the sensor a70, and also make the connecting part in the assembly less likely to loosen, thereby improving the service life of the whole assembly.

[0087] Further, referring to Figure 7 and Figure 10 , the rotating part a41 is provided with a snap spring groove a44 near the swing part a42; a snap spring a110 is assembled at the snap spring groove a44; the connecting frame a50 is provided with a U-shaped bending, which includes two side plates a53 and a bottom plate a54, and the mounting hole a51 is arranged on the two side plates a53; the rotating part a41 is further provided with a limiting sleeve a120, and the two side plates a53 are arranged between the snap spring a110 and the limiting sleeve a120.

[0088] Specifically, referring to Figure 10 , the rotating part a41 further includes a shaft sleeve a140, and the rotating part a41 is rotationally connected with the mounting hole a51 through the shaft sleeve a140. The shaft sleeve a140 passes through the mounting hole a51 on the two side plates a53 and is located between the snap spring a110 and the limiting sleeve a120, so that the rotating rod a40 is prevented from jumping axially along the rotating part a41, thereby improving the stability of the power rotation process.

[0089] Further, referring to Figure 7 and Figure 8 , a torsion spring a130 is arranged between the two side plates a53, one end of the torsion spring a130 abuts against the limiting portion a43, and the other end of the torsion spring a130 abuts against the bottom plate a54; the rotating portion a41 penetrates the torsion spring a130. The "one end of the torsion spring a130" specifically refers to Figure 9 one force arm of the torsion spring a130 abutting against the limiting portion a43; the "other end of the torsion spring a130" specifically refers to Figure 7 or Figure 8 the other force arm of the torsion spring a130 abutting against the bottom plate a54.

[0090] The design of the torsion spring enables the rotating rod a40 to automatically reset after the power of the knee leaning driving component a200 disappears.

[0091] Further, referring to Figure 10 , the sensor a70 and the sensed member a80 are arranged in the housing a60.

[0092] According to an embodiment of the present application, the sensor a70 is a Hall sensor arranged on a circuit board; the sensed member a80 is a magnet; the mounting sleeve a90 is a low-permeability material; and the rotating rod a40 is an iron rod. The present application is not limited thereto.

[0093] As shown in Figures 13-15 , the edge trimming assembly of the sewing machine comprises

[0094] a bearing seat b1 arranged on the main body of the sewing machine;

[0095] an edge trimming motor b3 mounted on the bearing seat b1 and used for providing power;

[0096] an edge trimming assembly b2 arranged on the bearing seat b1 and vertically liftable;

[0097] a crank connecting rod assembly b32 arranged in the bearing seat b1, one end of which is a power input end b35 and the other end of which is a power output end b36; the power input end b35 is connected with the motor shaft b31 of the driving motor b3, and the power output end b36 is connected with the edge trimming assembly b2;

[0098] a knife holder guide b11 arranged in the bearing seat b1 and having a vertical sliding groove b12; the power output end b36 is provided with a sliding block b13, the sliding block b13 is located in the sliding groove b12, and the sliding block b13 is connected with a guide column b21 of the edge trimming assembly b2; the crank connecting rod assembly b32 converts the rotation of the motor shaft b31 into the vertical lifting of the edge trimming assembly b2.

[0099] The trimming assembly b2 is driven by the trimming motor b3. When the trimming motor b3 is started, the power input end b35 transmits power to the trimming assembly b2 connected to the power output end b36 through the crank connecting rod assembly b32.

[0100] Since the tool holder guide frame b11 is vertically fixed on the bearing seat b1, the horizontal displacement of the sliding block b13 is limited by the sliding groove b12, so that the sliding block b13 can only move up and down. Since the sliding block b13 is connected to the guide column b12, when the guide column b21 is driven to move by the power output end b36, the sliding block b13 limits the horizontal displacement of the guide column b12 at the same time, realizing the conversion of the rotation of the motor shaft b31 into the vertical lifting of the trimming assembly b2, reducing the shaking of the trimming assembly b2, and improving the accuracy of the trimming cutter b25.

[0101] As shown in Figures 13-15 , the crank connecting rod assembly b32 includes a crank shaft sleeve b33, a connecting rod b34 and a guide column b21; the crank shaft sleeve b32 is arranged on the motor shaft b31, the swinging end of the crank shaft sleeve b32 is hinged to the upper end of the connecting rod b33, the lower end of the connecting rod b33 is sleeved on the guide column b21, one end of the guide column b21 is fixedly connected to the upper end of the trimming assembly b2, and the other end of the guide column b21 is connected to the sliding block b13.

[0102] When the trimming motor b3 is started, the crank shaft sleeve b33 fixed on the motor shaft b31 also rotates with the motor shaft b31, and drives the guide column b21 to move through the connecting rod b33. Since one end of the guide column b21 is connected to the sliding block b13 in the tool holder guide frame b11, the guide column b21 can only move in the direction of the tool holder guide frame b11.

[0103] The other end of the guide column b21 is connected to the cutter bar b20 of the trimming assembly b2, so when the guide column b21 is driven by the trimming motor b3 and starts to move, it will drive the cutter bar b20 to move in the direction of the tool holder guide frame b11, thereby realizing the transmission of the power generated by the driving motor b3 to the trimming assembly b2.

[0104] As shown in Figures 13-15 , the trimming assembly b2 is provided with a cutter bar b20 and a tool holder b22; the tool holder b22 includes a fixed support b221 and an adjusting support b222; the fixed support b222 is installed at the lower end of the cutter bar b20, the top end of the adjusting support b222 is formed with a groove b23 matched with the fixed support b221, and the adjusting support b222 is assembled on the fixed support b221 through the groove b23;

[0105] The knife holder b22 is used for connecting the knife rod b20 and the cutting knife b25. One end of the fixed support b221 is connected to the bottom end of the knife rod b20. The top end of the adjusting support b222 is shaped with a groove b23 matched with the fixed support b222. The adjusting support b222 is assembled on the other end of the fixed support b221 through the groove b23.

[0106] The surface of the adjusting support b222 is provided with an adjusting groove b24. The fixed support b221 and the adjusting support b222 are screwed into one body through the adjusting groove b24. The cutting knife b25 is mounted on the lower part of the adjusting support b222.

[0107] During operation, the function of moving the adjusting support b222 can be realized by changing the position of the bolt passing through the adjusting groove b24, and then the position of the cutting knife b25 in the left-right direction can be adjusted.

[0108] As shown in Figures 15-18 , the top end of the cutting knife b25 is shaped with a U-shaped groove b26. The adjusting support b222 is provided with a plurality of adjusting threaded holes b29. The adjusting bolt b27 is assembled into the adjusting threaded hole b29 through the U-shaped groove b26. The adjusting bolt b27 and the U-shaped groove b26 are provided with a gasket b28 therebetween.

[0109] The screwing between the cutting knife b25, the gasket b28 and the adjusting support b22 is realized through the adjusting bolt b27. The cutting knife b25 is fixed on the adjusting support b22, so that the cutting knife b25 can move with the cutting edge assembly b2.

[0110] After the adjusting bolt b27 is fastened, the U-shaped groove b26 shaped on the top end of the cutting knife b25 is pressed by the gasket b28, so that the cutting knife b25 is fixed. The adjusting bolt b27 can be installed into the adjusting threaded hole b29 of different heights to realize the function of adjusting the height of the cutting knife b25. During the adjustment of the cutting knife b25, the upper end of the cutting edge assembly b2 is limited by the knife holder guide frame, so that the displacement in the front-back direction is not easy to occur, and the positioning of the cutting knife b25 is more accurate. A plurality of holes are provided on the gasket b28, which can facilitate the installation of the adjusting bolt b27 in cooperation with the U-shaped groove b26.

[0111] When installed on different models of sewing machines, the height of the cutting knife 25 needs to be adjusted. The adjusting bolt 27 can be connected to the adjusting threaded hole 29 of different heights, and the position of the gasket 28 can be changed, so that sufficient clamping force can be provided for the cutting knife 25, and the cutting knife 25 is fixed on the adjusting support 222.

[0112] As shown in Figure 13 and Figure 14 , the width of the fixed support b221 is smaller than the distance between the needle rod b43 and the presser foot rod b46, so that the fixed support b221 extends from between the needle rod b43 and the presser foot rod b46.

[0113] In order to reduce the cost of upgrading the sewing machine on the market, the present application is a separate structure, which can be installed on the existing sewing machine shell b4 to realize the upgrading of the sewing machine without the need for special production of new sewing machines. Therefore, the width of the fixed support b221 should be less than the distance between the needle bar b43 and the presser foot lifting rod b46, so as to facilitate installation and not affect the normal operation of the sewing machine.

[0114] Due to the use of a separate trimming motor b3, the transmission between the trimming assembly b2 and other mechanisms is separated, reducing mutual interference. The controller can send signals to the trimming motor b3 of the trimming assembly b2 and the driving motor of the sewing machine synchronously, realizing the synchronization of the presser foot lifting action, the needle bar action and the trimming action, and improving the accuracy and stability of the sewing machine during operation.

[0115] As shown in Figure 17 and Figure 18 , the cutter b25 abuts against the tungsten sheet b48 inside the needle plate 47, and the tungsten sheet b48 has the function of a fixed cutter. Correspondingly, replacing the tungsten sheet b48 with other wear-resistant hard metal materials is also an equivalent replacement. Since tungsten has high hardness and strength, and is resistant to corrosion and rust, the tungsten sheet b48 made of tungsten has good wear resistance, which reduces the wear of the needle plate b47 caused by the frequent up-and-down movement of the cutter b25, and also plays a positioning role for the cutter b25, increasing the beauty of the finished product.

[0116] As shown in Figure 16 and Figure 18 , the bearing seat b1 is an end cover of the sewing machine;

[0117] The bearing seat b1 is installed on the sewing machine shell b4.

[0118] The bearing seat b1 can be connected to the sewing machine shell b4 in the form of an end cover, which can reduce the cost of upgrading the existing sewing machine, complete the assembly of the trimming assembly of the sewing machine without affecting the overall appearance of the sewing machine, and also does not occupy too much space.

[0119] The cutter rod b20 is sleeved with the sleeve b15, and the cutter rod b20 passes through the sleeve b15 and comes out from the assembly hole b16.

[0120] Through the sleeve b15, the shaking of the cutter rod b20 can be further reduced, the displacement of the trimming assembly b2 can be reduced, and the accuracy of the trimming assembly b2 can be improved. At the same time, the sleeve b15 can protect the cutter rod b20 from colliding with the assembly hole b16, reducing the wear of the cutter rod b20 caused by friction.

[0121] The trimming motor b3 is arranged transversely, and the motor shaft b31 is parallel to the main shaft of the sewing machine.

[0122] The motor shaft b31 of the driving motor b3 is parallel to the main shaft of the sewing machine, so that the reciprocating stroke between the cutting action, the material piercing action and the presser foot lifting action is equivalent, and the frequency between the cutting motor b3 and the sewing motor can be synchronized by the controller, so that the sewing machine can work normally without the frequency difference between the cutting action and other actions.

[0123] As shown in Figure 16 and Figure 18 , the bearing seat b1 is provided with a cover b14 for protecting the cutting motor b3; the cover b14, the bearing seat b1 and the sewing machine shell b4 are connected by bolts.

[0124] The cutting motor b3 is arranged in the cover b14, and the cover is arranged behind the bearing seat b1 to facilitate the installation of the cutting motor b3 and protect the cutting motor b3. The power is transmitted to the cutting assembly b2 through the crank connecting rod assembly b32 in the bearing seat b1 to drive the cutting assembly b2 to move. The cover b14, the bearing seat b1 and the sewing machine shell b4 are connected by bolts, which is convenient for installation and can provide good fixation.

[0125] As shown in Figure 13 , the knife holder guide b11 is a separate component independent of the bearing seat b1; accordingly, those skilled in the art should understand that the present application also does not exclude that the knife holder guide b11 and the bearing seat b1 are integrally formed, and the knife holder guide b11 is formed on the corresponding part of the bearing seat b1.

[0126] The basic principles and main features of the present application and the advantages of the present application have been shown and described. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A sewing machine comprising a frame, and a stitch length adjustment mechanism, a thread trimming mechanism and a presser foot lifting mechanism arranged on the frame, characterized in that: A driving motor (5) is provided at the lower part of the frame, and a first output shaft (7) of the driving motor is used to drive the swing seat (9) of the stitch length adjustment mechanism (4); a second output shaft (6) of the driving motor (5) extends forward and drives the thread trimming mechanism; and a first output shaft (7) of the driving motor (5) extends backward and drives the presser foot lifting mechanism and the stitch length adjustment mechanism. A first support shaft (10) is provided on one side of the swing seat (9), and one end of the first support shaft (10) drives the swing seat (9) to swing within a set angle; the other end of the first support shaft (10) extends toward the position of the drive motor and is installed with a first toggle member (11), and a first sliding groove (12) is provided on the first toggle member (11); a first crank (8) is installed on the first output shaft (7), and a slider (13) is installed on the first crank (8), and the slider (13) slides in the first sliding groove (12); The presser foot lifting mechanism comprises: a first cam (14) mounted on the first output shaft (7); A double swing arm (15) is rotatably mounted on the frame (1); the double swing arm (15) comprises a first swing arm (16) and a second swing arm (17); a swing arm end of the first swing arm (16) is hingedly connected to a presser foot lifting connecting rod, and a swing arm end of the second swing arm (17) abuts against the first cam (14); The double-linked rocker (15) is arranged below the first toggle member (11), and the first toggle member (11) is located between the first rocker arm (16) and the second rocker arm (17) of the double-linked rocker (15); A rotating shaft (28) is provided on the double-jointed rocker (15), and the double-jointed rocker (15) rotates around the rotating shaft (28); A return spring (29) for returning the presser foot is provided on the rotating shaft (28), one end of the return spring (29) is provided on the frame (1), and the other end is provided on the double rocker (15).

2. A sewing machine according to claim 1, characterized in that: The first support shaft (10) and the first output shaft (7) are arranged up and down in a vertical plane and front and back in a horizontal plane; the slider (13) is rotatably mounted on the swing end of the first crank (8).

3. A sewing machine according to claim 1, characterized in that: A second support shaft (19) is provided on the other side of the swing seat (9); the first support shaft (10) and the second support shaft (19) are provided on the same axis and extend into two sides of the swing seat (9) respectively; A second shifting member (20) is further provided on the first supporting shaft (10), and a second sliding groove (21) is provided on the second shifting member (20); A toggle pin (22) is provided on the side of the swing seat (9) adjacent to the first support shaft (10), and the toggle pin (22) is arranged in the second sliding groove (21).

4. A sewing machine according to claim 1, characterized in that: The first cam (14) includes a rotating end (26) and a protruding end (27), wherein the rotating end (26) is connected to the first output shaft (7), and the protruding end (27) is used to move the second swing arm (17); The first cam (14) has a working curved surface and a non-working curved surface, the working curved surface being the circumferential surface of the protruding end (27), and the non-working curved surface being the circumferential surface of the rotating end (26).

5. A sewing machine according to any one of claims 1 to 3, characterized in that: The thread cutting mechanism comprises: a second cam (24) for driving the thread trimmer shaft (31) and the thread trimmer crank (32); A through hole (25) is formed on the second cam (24); one end of the second crank (23) is disposed in the through hole (25); and the working curved surface of the second cam (24) is the inner wall of the through hole (25); The second crank (23) is mounted on the second output shaft (6) of the driving motor; the second crank (23) is used to drive the second cam (24).

6. A sewing machine according to claim 1, characterized in that: A knee support assembly is provided at the lower portion of the frame, which includes: A sensor (a70) for obtaining a trigger signal; A sensed component (a80), used for triggering the sensor (a70); The knee-rest actuator (a100) is used to drive the sensing element (a80) to move along a set trajectory; A knee-rest driving component (a200), used for driving the knee-rest actuator component (a100); A connecting frame (a50), which is used to be fixed on an adapted sewing machine and directly or indirectly carry other components; The knee-rest actuator (a100) includes a rotating rod (a40) and a mounting sleeve (a90); The rotating rod (a40) includes: a rotating portion (a41), a swinging portion (a42) and a limiting portion (a43); the rotating portion (a41), the swinging portion (a42) and the limiting portion (a43) are integrally formed; The rotating part (a41) is rotatably mounted on the connecting frame (a50); one end of the rotating part (a41) extends out of the connecting frame (a50) and is connected to the knee support driving component (a200); The swinging portion (a42) is provided at the other end of the rotating portion (a41) and is bent to one side; The limiting portion (a43) is arranged at the swinging end of the swinging portion (a42) and is bent toward the other side; the end of the limiting portion (a43) extends into the waist-shaped hole (a52) of the connecting frame (a50); The mounting sleeve (a90) is provided on the swing portion (a42) or the limiting portion (a43), and the sensing component (a80) is provided on the mounting sleeve (a90); The installation sleeve (a90) is provided with an installation groove fixing portion (a91), a fixing cap portion (a92) and a side leaning portion (a93); The mounting sleeve is arranged at the corner where the swing portion (a42) and the limiting portion (a43) are connected; A fixed cap portion (a92) is sleeved on the limiting portion (a43); A side leaning portion (a93) rests on the swinging portion (a42); The side leaning portion (a93) is provided with a fixing hole (a94) and is fixed to the swinging portion (a42) by screws passing through the fixing hole (a94); The installation sleeve (a90) is a plastic part.

7. A sewing machine according to claim 1, characterized in that: The end cover at the front of the frame forms a bearing seat (b1); the bearing seat (b1) is equipped with a trimming motor (b3), a cutter assembly (b2), a crank connecting rod assembly (b32) and a cutter guide frame (b11); The cutter assembly (b2) is arranged on the supporting seat (b1) and can be lifted and lowered vertically; the crank connecting rod assembly (b32) is arranged in the supporting seat (b1), one end of which is a power input end (b35) and the other end is a power output end (b36); the power input end (b35) is connected to the motor shaft (b31) of the trimming motor (b3), and the power output end (b36) is connected to the cutter assembly (b2); the knife holder guide frame (b11 ), is arranged in the bearing seat (b1), and has a vertical slide groove (b12); the power output end (b36) is provided with a guide slider (b13), the guide slider (b13) is located in the slide groove (b12), and the guide slider (b13) is connected to the guide column (b21) of the cutter assembly (b2); the crank connecting rod assembly (b32) converts the rotation of the motor shaft (b31) into the vertical lifting of the cutter assembly (b2).

8. A sewing machine according to claim 7, characterized in that: The crank-connecting rod assembly (b32) includes a crank sleeve (b33), a connecting rod (b34) and a guide column (b21); the crank sleeve (b33) is provided on the motor shaft (b31); the swing end of the crank sleeve (b33) is hinged to the upper end of the connecting rod (b34); the lower end of the connecting rod (b34) is sleeved on the guide column (b21); one end of the guide column (b21) is fixedly connected to the upper end of the cutter assembly (b2); and the other end of the guide column (b21) is connected to the guide slider (b13); The cutter assembly (b2) is provided with a cutter bar (b20) and a cutter holder (b22); the cutter holder (b22) includes a fixed bracket (b221) and an adjustment bracket (b222); the fixed bracket (b221) is mounted on the lower end of the cutter bar (b20), and the top end of the adjustment bracket (b222) is formed with a groove (b23) adapted to the fixed bracket (b221), and the adjustment bracket (b222) is assembled on the fixed bracket (b221) through the groove (b23); The surface of the adjusting bracket (b222) is provided with an adjusting groove (b24), and a bolt passes through the adjusting groove (b24) to screw the fixing bracket (b221) and the adjusting bracket (b222) into one body; A cutter (b25) is installed at the lower part of the adjustment bracket (b222).

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