Sewing machine with stitch length adjustment and positioning swing seat zero

Abstract

The utility model provides a sewing machine with needle spacing adjustment and positioning swing seat zero position, specifically relates to sewing machine manufacturing technical field. Including drive source and swing seat zero position positioning mechanism, its characterized in be, drive source drives the slider on the output shaft indirectly to swing seat and executes swing seat zero position positioning. The utility model discloses a sewing machine with needle spacing adjustment and positioning swing seat zero position has the characteristics of high precision of positioning swing seat zero point position compared with prior art, and the static positioning wheel is fixed with the adjusting dynamic wheel, makes the operation more stable, the clearance of each component is smaller after positioning, the mechanical wear degree of each component is smaller, and the noise is relatively lower, has the advantages of stable operation, the drive source of the utility model preferably uses the step motor or servo motor, so that the drive source can be smoothly realized under the intelligent control program of sewing machine, has higher popularization and use value.

Description

TECHNICAL FIELD

[0001] The utility model provides a sewing machine with needle spacing adjustment and positioning swing seat zero position adjustment, and particularly relates to the technical field of sewing machine manufacturing. BACKGROUND

[0002] The swing seat of the sewing machine is one of the key parts of needle spacing adjustment and cloth feeding action. The existing patent technology proposes a sewing machine with zero position positioning function, which comprises a driving motor, a driving wheel, a needle spacing lever, a needle spacing adjustment connecting rod and a swing seat driving motor. The driving wheel drives the needle spacing lever and the needle spacing adjustment connecting rod to act on the swing seat. The driving wheel has a needle spacing adjustment and zero position positioning wheel. The driving motor drives the needle spacing adjustment and zero position positioning wheel to push the sliding member of the needle spacing lever into the cloth feeding tooth zero position positioning groove of the needle spacing adjustment and zero position positioning wheel. The sliding member indirectly acts on the swing seat to make the swing seat in the zero position state. The needle spacing adjustment and zero position positioning wheel has a zero position transition groove one and a zero position transition groove two. The sliding member enters the cloth feeding tooth zero position positioning groove from the zero position transition groove one or the zero position transition groove two. The sliding member entering the cloth feeding tooth zero position positioning groove is the zero position of the cloth feeding tooth of the sewing machine. The needle spacing adjustment and zero position positioning wheel pushes the sliding member to change the action position with the needle spacing adjustment groove of the needle spacing adjustment and zero position positioning wheel under the driving of the driving motor, and then changes the original swing angle of the swing seat through the needle spacing lever and the needle spacing adjustment connecting rod. The sewing machine with zero position positioning function has the beneficial effect that the driving motor drives the cam, the cam drives the rotating rod, and the sewing machine realizes the needle spacing adjustment action in the stop state. Since the driving wheel is installed on the driving motor and rotates with the motor, high requirements are put forward for the machining and installation precision of the driving wheel, which makes the zero position positioning of the swing seat of the sewing machine inaccurate and affects the sewing quality. SUMMARY

[0003] In view of the above-mentioned sewing machine in the positioning zero position technology exists not accurate positioning defects, especially to solve the above problems is provided with stitch length adjustment and positioning swing seat zero sewing machine, including drive source and swing seat zero positioning mechanism, characterized in that, the drive source drive has the output shaft on the slider indirectly to swing seat swing seat zero position positioning; The swing seat zero positioning mechanism includes static positioning wheel, adjusting dynamic wheel, swing seat, connecting rod, slider and feed shaft, the static positioning wheel is fixed, the output shaft of the drive source passes through the static positioning wheel and is fixed with the slider, the slider is arranged on the sliding groove of the adjusting dynamic wheel, the sliding groove is arranged at the center position of the adjusting dynamic wheel, the sliding groove is provided with shaft groove hole and shaft hole, the shaft groove hole is in the shape of a long hole, the shaft hole is communicated with the shaft groove hole, the sliding groove is further provided with a sliding member, the static positioning wheel has a stitch length adjustment and positioning groove, the sliding member is higher than the adjusting dynamic wheel and extends to the inside of the stitch length adjustment and positioning groove, the connecting rod is provided with a ring gap, which is matched with the annular step of the adjusting dynamic wheel, the connecting rod is hinged with the swing seat, and the swing seat is indirectly positioned by the slider on the output shaft of the drive source.

[0004] Preferably, the stitch length adjustment and positioning groove further has transition groove one and transition groove two, the sliding member is arranged at the longitudinal center position of the sliding groove and at the eccentric position of the adjusting dynamic wheel, the sliding member enters the positioning groove from the transition groove one or the transition groove two, the positioning groove is arranged in concentric circles with the output shaft, and the shaft hole is communicated with the shaft groove hole.

[0005] Preferably, the swing seat has a short swing bar and a long swing bar, and the upper planes of the short swing bar and the long swing bar are in parallel or coplanar state under the indirect action of the sliding member.

[0006] Preferably, the stitch length adjustment and positioning groove of the static positioning wheel further has a stitch length adjustment groove, the output shaft of the drive source drives the slider to change the acting position on the stitch length adjustment groove, the adjusting dynamic wheel and the swing seat are connected by the connecting rod, and the acting position between the sliding member and the stitch length adjustment groove is changed to form a new stitch length.

[0007] Preferably, the drive source is fixed on the side of the sewing machine body; or the drive source is fixed on the back of the machine body, and the drive source uses a stepping motor or a servo motor.

[0008] Preferably, the static positioning wheel is fixed on the side of the machine body by a screw, and the static positioning wheel is fixed on the output shaft close to the drive source.

[0009] Preferably, the static positioning wheel has a through hole and the output shaft is arranged in concentric circles, the stitch length adjustment and positioning groove is a closed groove, and the through hole is located in the inside of the stitch length adjustment and positioning groove.

[0010] Preferably, the sewing machine also has a presser foot lifting mechanism and a thread trimming mechanism, after the sliding piece enters the needle spacing adjustment groove positioning swing seat zero position, the driving source drives the output shaft to drive the adjusting gear to rotate in the ring of the connecting rod, at this time the driving source continues to run, the sliding piece gives the connecting rod and the swing seat no swing source transmission, at this time, the sewing machine commands the driving source to perform the presser foot lifting action of the presser foot lifting mechanism and the thread trimming action of the thread trimming mechanism.

[0011] Preferably, the driving source has a needle spacing adjustment operation angle, a swing seat zero position positioning operation angle, a presser foot lifting operation angle and a thread trimming operation angle, and each sewing action is operated at the respective angle, and each operation angle does not interfere with each other, and the driving source driving output shaft is used to implement needle spacing adjustment, swing seat zero position positioning, presser foot lifting and thread trimming action in different time periods and different operation angles.

[0012] Preferably, the thread trimming mechanism has a thread trimming crank, a thread trimming fork wheel and a thread trimming end execution end, the thread trimming crank is provided with a pusher at the deflection position, the thread trimming fork wheel has a return rod and a thread trimming rod, the pusher is located between the return rod and the thread trimming rod, the driving source drives the pusher to rotate and press down the thread trimming rod to transmit the thread trimming end execution end to provide the thread trimming force, and the thread trimming end execution end completes the thread trimming action, after the thread trimming is completed, the driving source continues to rotate with the pusher to the return rod, and the return rod returns to the original position, thereby completing the reset of the entire thread trimming mechanism; the presser foot lifting mechanism has a presser foot lifting cam, a presser foot lifting top rod and a presser foot lifting end execution end, the driving source drives the presser foot lifting cam at the presser foot lifting operation angle, the presser foot lifting cam has an idle surface, and the presser foot lifting cam has a cam surface as a lifting surface for the presser foot lifting action, the driving source drives the output shaft to rotate the presser foot lifting cam to realize the lifting of the presser foot lifting top rod, and the presser foot lifting top rod finally makes the presser foot lifting end execution end execute the presser foot lifting action, the thread trimming crank and the presser foot lifting cam are installed on the output shaft, and the thread trimming crank is located at the outermost side of the output shaft.

[0013] Compared with the prior art, the sewing machine with needle spacing adjustment and swing seat zero position positioning has the characteristics of high accuracy of positioning the swing seat zero position, the static positioning wheel is fixed with the adjusting gear to make the operation more stable, the gap between the components after positioning is small, the mechanical wear of each component is small, the noise is relatively low, and the operation is stable. The driving source of the present application preferably uses a stepping motor or a servo motor, so that the driving source can be smoothly realized under the intelligent control program of the sewing machine, and has high popularization and application value. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a structural schematic diagram of a sewing machine with needle spacing adjustment and swing seat zero position positioning of the present application;

[0015] Figure 2This is a schematic diagram of a sewing machine swing seat zero-position positioning mechanism with stitch length adjustment and positioning swing seat zero position according to this application;

[0016] Figure 3 This is a schematic diagram of the adjusting wheel and output shaft of a sewing machine with stitch length adjustment and positioning swing seat zero position according to this application;

[0017] Figure 4 This is a schematic diagram of the adjustment wheel and connecting rod connection of a sewing machine with stitch length adjustment and positioning swing seat zero position according to this application;

[0018] Figure 5 This is a schematic diagram of the installation of a sewing machine needle pitch groove wheel with needle pitch adjustment and positioning swing seat zero position according to this application;

[0019] Figure 6 This is a structural diagram of the adjusting wheel of a sewing machine with stitch length adjustment and positioning swing seat zero position, as described in this application;

[0020] Figure 7 This is a structural diagram of a sewing machine needle pitch groove wheel with needle pitch adjustment and positioning swing seat zero position according to this application;

[0021] Figure 8 This is a structural diagram of a sewing machine linkage with stitch length adjustment and positioning swing seat zero position according to this application;

[0022] Figure 9 This is a schematic diagram of a sewing machine with a presser foot lifting mechanism and a thread cutting mechanism that has needle pitch adjustment and a zero position positioning swing seat.

[0023] Reference numerals: Sewing machine 10, machine body 11, screw 12, drive source 20, output shaft 21, swing seat zero-positioning mechanism 40, stationary positioning wheel 41, through hole 411, stitch length adjustment and positioning groove 412, adjusting moving wheel 42, slide groove 421, stitch length adjustment groove 4121, positioning groove 4122, transition groove one 4123, transition groove two 4124, shaft groove hole 422, sliding part 423, annular step 424, shaft hole 425, swing seat 43, short swing bar 431, long swing bar 432, connecting rod 44, ring 441, slider 45, feed shaft 46, presser foot lifting mechanism 50, thread cutting mechanism 60, pusher 611, presser foot lifting rod 52, thread cutting fork wheel 62, thread cutting crank 61, presser foot lifting cam 51, return rod 621, thread cutting rod 622, stitch length adjustment 80. Detailed Implementation

[0024] The following is in conjunction with the appendix Figures 1-9 The preferred embodiments of this application are described in detail so that the advantages and features of this application can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the scope of protection of this application. These embodiments are only used to illustrate the present invention and are not intended to limit the present invention.

[0025] Figure 1 Figure 2 The present application provides a general structure of a sewing machine with stitch length adjustment and swing seat zero position positioning, which comprises a driving source 20, a stitch length adjustment 80, a swing seat zero position positioning mechanism 40, a presser foot lifting mechanism 50 and a thread trimming mechanism 60. The output shaft 21 of the driving source 20 is installed and drives the stitch length adjustment 80, the swing seat zero position positioning mechanism 40, the presser foot lifting mechanism 50 and the thread trimming mechanism 60. The sewing machine 10 can adjust the stitch length of the stitch length adjustment 80 under the driving of the driving source 20, and can position the swing seat zero position under the driving of the swing seat zero position positioning mechanism 40. The presser foot lifting mechanism 50 and the thread trimming mechanism 60 can be driven under the driving of the same driving source 20. The driving source 20 drives the four mechanisms in different time periods and different rotation angles to achieve the technical purpose of positioning the swing seat zero position in a stable structure. The driving source 20 is fixed on the side of the machine body 11 or on the back of the machine body 11, and a stepping motor or a servo motor is preferably used in the present application.

[0026] In combination Figures 1 to 8 The swing seat zero position positioning mechanism 40 comprises a static positioning wheel 41, an adjustment driving wheel 42, a swing seat 43, a connecting rod 44, a sliding block 45 and a feed shaft 46. The static positioning wheel 41 is fixed and static. The output shaft 21 of the driving source 20 passes through the through hole 411 of the static positioning wheel 41, and the static positioning wheel 41 is fixed on the side of the machine body 11. The static positioning wheel 41 is fixed on the side of the machine body 11 by screws 12. The output shaft 21 is located in the through hole 411 of the static positioning wheel 41.

[0027] The through hole 411 of the static positioning wheel 41 and the output shaft 21 are concentric circles. The static positioning wheel 41 has a stitch length adjustment and positioning groove 412, which is a closed groove. The through hole 411 is located in the stitch length adjustment and positioning groove 412. The stitch length adjustment and positioning groove 412 has a stitch length adjustment groove 4121, a positioning groove 4122, a transition groove one 4123 and a transition groove two 4124 between the stitch length adjustment groove 4121 and the positioning groove 4122. The stitch length adjustment groove 4121 is used for stitch length adjustment, the positioning groove 4122 is used for positioning the swing seat zero position, and the transition groove one 4123 and the transition groove two 4124 serve as the transition between the stitch length adjustment groove 4121 and the positioning groove 4122.

[0028] The output shaft 21 is further provided with an adjusting driving wheel 42 and a sliding block 45, the sliding block 45 is fixed on the output shaft 21, and in this embodiment, the sliding block 45 is fixed on the output shaft 21 by a small screw in the center hole thereof. The sliding block 45 is located outside the static positioning wheel 41. The center of the adjusting driving wheel 42 is provided with a sliding groove 421, the sliding groove 421 is matched with the sliding block 45 inside the gap, and the sliding groove 421 is used for sliding of the sliding block 45; the adjusting driving wheel 42 is provided with an axle slot hole 422, a sliding part 423 and an axle hole 425, the axle slot hole 422 is located at the center of the adjusting driving wheel 42, the axle slot hole 422 is a long hole through the adjusting driving wheel 42, the axle slot hole 422 extends from the center of the adjusting driving wheel 42 to the edge, the output shaft 21 passes through the axle slot hole 422, and the axle slot hole 422 is used for avoiding the output shaft 21 during rotation of the adjusting driving wheel 42; the axle hole 425 is located at the center of the adjusting driving wheel 42, and is used for operation of the output shaft 21 at the center of the adjusting driving wheel 42, and the axle hole 425 is communicated with the axle slot hole 422. The sliding part 423 is arranged on the sliding groove 421 of the adjusting driving wheel 42, and is arranged at an eccentric position of the adjusting driving wheel 42. The sliding part 423 is higher than the adjusting driving wheel 42 and extends into the needle spacing adjusting and positioning groove 412 of the static positioning wheel 41, the sliding part 423 is limited to operate in the needle spacing adjusting groove 4121 of the needle spacing adjusting and positioning groove 412, and the sliding part 423 slides in each different operation groove in the needle spacing adjusting and positioning groove 412 under the operation of the sliding block 45 to push the adjusting driving wheel 42, and the adjusting driving wheel 42 further generates different swing sources to the connecting rod 44 and the swing seat 43.

[0029] The adjusting driving wheel 42 is connected with the connecting rod 44, the upper end of the connecting rod 44 has a circular ring 441, the connecting rod 44 is sleeved on the annular step 424 of the adjusting driving wheel 42 in the shape of the circular ring 441, the connection between the two is achieved in a sleeved and connected manner, and the gap between the circular ring 441 and the annular step 424 is matched. After the driving source 20 drives the sliding block 45 through the output shaft 21, the sliding block 45 rotates and pushes the sliding part 423 of the sliding groove 421, so that the whole adjusting driving wheel 42 operates correspondingly in the needle spacing adjusting and positioning groove 412 with the sliding block 45. The other end of the connecting rod 44 is indirectly hinged with the swing seat 43, and the swing seat 43 is hinged with the cloth feeding shaft 46 in a swing output mode. The operation of the adjusting driving wheel 42 can drive the connecting rod 44 to generate a swing source on one hand, so that the needle spacing adjusting and swing seat zero positioning can be implemented (the two actions of needle spacing adjusting and swing seat zero positioning only differ in the position of the sliding groove 421 and the sliding part 423), and on the other hand, the operation of the adjusting driving wheel 42 can make the connecting rod 44 be in a relatively static state. When the connecting rod 44 does not exert a pushing force on the swing seat 43, the driving source 20 implements the lifting of the presser foot action or the cutting of the thread action.

[0030] The driving source 20 has a needle spacing adjustment operation angle, a swing seat zero position positioning operation angle, a presser foot lifting operation angle and a thread cutting operation angle. The needle spacing adjustment and swing seat zero position positioning, presser foot lifting and thread cutting are all operated by the driving source 20 according to the preset operation angles. The respective sewing actions are operated at the respective angles. The respective operation angles are performed at different times and do not interfere with each other. The respective actions are clear and distinct.

[0031] The needle spacing adjustment and positioning groove 412 has a needle spacing adjustment groove 4121, a positioning groove 4122, a transition groove one 4123 and a transition groove two 4124 between the needle spacing adjustment groove 4121 and the positioning groove 4122. The needle spacing adjustment groove 4121 is used for needle spacing adjustment. The positioning groove 4122 is used for swing seat zero position positioning and is applied to presser foot lifting or thread cutting.

[0032] When the sewing machine 10 is to perform needle spacing adjustment, the output shaft 21 of the driving source 20 drives the slider 45 to drive the sliding piece 423 to operate at the original operation angle, so as to rotate and change the action position of the sliding piece 423 on the needle spacing adjustment groove 4121. The driving source 20 drives the slider 45 to indirectly perform needle spacing adjustment on the swing seat 43, so that the sewing machine 10 generates a new needle spacing. The connecting rod 44 is connected between the adjusting pulley 42 and the swing seat 43 to transmit the rotation angle. The change of the action position between the sliding piece 423 and the needle spacing adjustment groove 4121 realizes the change of the swing angle of the swing seat 43, so as to form a new needle spacing. The swing seat 43 indirectly transmits the changed actual swing angle to the feed dog of the sewing machine through the feed shaft 46. The feed dog finally sews with a new needle spacing.

[0033] When the sewing machine 10 is to perform the positioning swing seat zero position action, the sliding piece 423 enters the positioning groove 4122 from the needle spacing adjustment groove 4121 through the transition groove one 4123 or the transition groove two 4124. When the sliding piece 423 enters the positioning groove 4122 from the transition groove one 4123 or the transition groove two 4124, that is, the sliding piece 423 enters the positioning groove 4122, the swing seat zero position is determined, and the sliding piece 423 pushes the swing seat 43 into the swing seat zero position state through the connecting rod 44. At this time, the positioning groove 4122 is arranged as a concentric circle with the output shaft 21, and the sliding piece 423 pushes the output shaft 21 in the shaft groove hole 422 of the adjustment gear 42 to the center position of the adjustment gear 42 under the driving of the output shaft 21. The swing seat 43 has a short swing bar 431 and a long swing bar 432, and specifically, the short swing bar 431 and the long swing bar 432 are in a parallel or coplanar state under the indirect action of the sliding piece 423. At this time, the swing seat 43 indirectly makes the feed dog in the zero needle spacing state through the feed shaft 46, that is, the feed dog loses the front and rear feed power. Therefore, the positioning of the swing seat zero position is determined by the interaction of the sliding piece 423 and the needle spacing adjustment groove 4121. The determination of the swing seat zero position effectively solves the problem of inaccurate zero position positioning of the existing sewing machine, improves the stability of sewing, and thus improves the sewing quality.

[0034] When the swing seat zero position is positioned, the gap fit between the annular ring 441 of the connecting rod 44 and the annular step 424 of the adjustment gear 42 makes the position of the connecting rod 44 and the adjustment gear 42 mutually constrained, and the reliable mechanical connection between the adjustment gear 42 and the connecting rod 44 realizes the reliability of the positioning of the swing seat zero position, overcoming the defect of low stability in the positioning of the prior art.

[0035] After the sliding piece 423 enters the needle spacing adjustment groove 4121 to position the swing seat zero position, the sliding piece 423 continues to stay in the needle spacing adjustment groove 4121, and at this time, the driving source 20 continues to operate, and the sliding piece 423 gives the connecting rod 44 and the swing seat 43 no swing source transmission. The driving source 20 drives the output shaft 21 to drive the adjustment gear 42 to idle in the annular ring 441 of the connecting rod 44, and at this time, the sewing machine 10 commands the driving source 20 to perform the lifting presser foot action of the lifting presser foot mechanism 50 and the cutting thread action of the thread cutting mechanism 60.

[0036] Referring to the drawings, Figure 2 Figure 9 The sewing machine with swing seat zero position positioning provided in the present application comprises a lifting presser foot mechanism 50 and a thread cutting mechanism 60. When the sewing machine 10 finishes sewing, the thread cutting action is performed first, and then the lifting presser foot action is performed, and the driving source 20 performs the lifting presser foot action at the lifting presser foot operation angle and performs the thread cutting action at the thread cutting operation angle.

[0037] The thread trimming mechanism 60 has a thread trimming crank 61, a thread trimming fork wheel 62 and a thread trimming end, and the presser lifting mechanism 50 has a presser lifting cam 51, a presser lifting rod 52 and a presser lifting end. The thread trimming crank 61 and the presser lifting cam 51 are installed on the output shaft 21, and the thread trimming crank 61 is located at the outermost side of the output shaft 21, and the presser lifting cam 51 is located between the adjusting driving wheel 42 and the thread trimming crank 61 near the side of the adjusting driving wheel 42.

[0038] The driving source 20 performs the thread trimming action at the thread trimming operation angle, and the output shaft 21 is located at the center of the adjusting driving wheel 42 at this time, and the adjusting driving wheel 42 and the connecting rod 44 are always idling regardless of the operation of the output shaft 21. The whole slot of the positioning slot 4122 is sufficient for the driving source 20 to perform the presser lifting action at the presser lifting operation angle and to perform the thread trimming action at the thread trimming operation angle.

[0039] The eccentric position of the thread trimming crank 61 is provided with a pushing piece 611, the thread trimming fork wheel 62 has a return rod 621 and a thread trimming rod 622, and the pushing piece 611 is located between the return rod 621 and the thread trimming rod 622. The driving source 20 drives the pushing piece 611 to rotate and press down the thread trimming rod 622 to transmit the thread trimming end to provide the thread trimming force, and the thread trimming end completes the thread trimming action. After the thread trimming is completed, the driving source 20 continues to rotate with the pushing piece 611 to the return rod 621, and the return rod 621 is returned to the original position, thereby completing the resetting of the whole thread trimming mechanism 60.

[0040] After the thread trimming is completed, the sewing machine 10 immediately performs the presser lifting action, and the driving source 20 drives the presser lifting cam 51 at the presser lifting operation angle. The presser lifting cam 51 has an idle surface of the circular arc surface, and has a cam surface of the presser lifting action. The driving source 20 drives the output shaft 21 to rotate the presser lifting cam 51 to use the lifting surface to lift the presser lifting rod 52, and the presser lifting rod 52 promotes the presser lifting end to perform the presser lifting action. The idle surface is set to make the output shaft 21 not to have actual effect on the presser lifting action in performing other sewing actions.

[0041] The above is only one of the preferred embodiments of the present application, and does not limit the patent implementation range of the present application. Any equivalent structure or equivalent process transformation using the shape, structure and principle of the contents of the present application specification and drawings, or direct or indirect application in other related technical fields, are all covered in the patent protection range of the present application.

Claims

1. A sewing machine with stitch length adjustment and a zero-position positioning mechanism for the swing seat, comprising a drive source (20) and a zero-position positioning mechanism for the swing seat (40), wherein the drive source (20) has an output shaft (21), characterized in that, The zero-position positioning mechanism (40) of the swing seat includes a stationary positioning wheel (41), an adjusting moving wheel (42), a swing seat (43), a connecting rod (44), a slider (45), and a feeding shaft (46). The stationary positioning wheel (41) is fixed. The output shaft (21) passes through the stationary positioning wheel (41) and is fixedly mounted on the slider (45). The slider (45) is set on the groove (421) of the adjusting moving wheel (42). The groove (421) is set at the center of the adjusting moving wheel (42). The groove (421) is provided with a shaft groove hole (422) and a shaft hole (425). The slot (422) is in the shape of an elongated inner hole. The shaft hole (425) is connected to the shaft slot (422). The sliding groove (421) is also provided with a sliding member (423). The stationary positioning wheel (41) has a needle pitch adjustment positioning groove (412). The sliding member (423) is higher than the adjusting moving wheel (42) and extends all the way to the positioning groove (4122) of the needle pitch adjustment positioning groove (412). The ring (441) of the connecting rod (44) is fitted with a clearance fit on the annular step (424) of the adjusting moving wheel (42). The connecting rod (44) is hinged to the swing seat (43). The needle pitch adjustment positioning groove (412) also has a transition groove one (4123) and a transition groove two (4124). The sliding member (423) is located at the longitudinal center of the sliding groove (421) and at the eccentric position of the adjusting wheel (42). The sliding member (423) enters the positioning groove (4122) from the transition groove one (4123) or the transition groove two (4124). The positioning groove (4122) and the output shaft (21) are arranged in concentric circles. The shaft hole (425) is connected to the shaft groove hole (422). The swing seat (43) has a short swing bar (431) and a long swing bar (432). Under the indirect action of the sliding member (423), the upper planes of the short swing bar (431) and the long swing bar (432) are in a parallel or coplanar state.

2. A sewing machine with stitch length adjustment and a zero-position positioning swing seat according to claim 1, characterized in that, The stationary positioning wheel (41) also has a stitch pitch adjustment groove (4121) in the stitch pitch adjustment positioning groove (4122). The output shaft (21) of the drive source (20) drives the slider (45) at the original running angle to drive the sliding member (423) to change the working position on the stitch pitch adjustment groove (4121). There is a connecting rod (44) between the adjusting wheel (42) and the swing seat (43). The working position between the sliding member (423) and the stitch pitch adjustment groove (4121) changes to form a new stitch pitch. The stationary positioning wheel (41) is fixed to the side of the machine body (11) with screws (12). The stationary positioning wheel (41) is fixed to the side of the output shaft (21) near the drive source (20).

3. A sewing machine with stitch length adjustment and a zero-position positioning swing seat according to claim 1, characterized in that, The drive source (20) is fixed on the side of the sewing machine body (11); or the drive source (20) is fixed on the back of the body (11), and the drive source (20) uses a stepper motor or a servo motor.

4. A sewing machine with stitch length adjustment and a zero-position positioning swing seat according to claim 1, characterized in that, The stationary positioning wheel (41) has a through hole (411) and an output shaft (21) arranged in concentric circles. The needle pitch adjustment positioning groove (412) is a closed groove, and the through hole (411) is located inside the needle pitch adjustment positioning groove (412).

5. A sewing machine with stitch length adjustment and a zero-position positioning swing seat according to claim 1, characterized in that, The sewing machine (10) also has a presser foot lifting mechanism (50) and a thread cutting mechanism (60). After the sliding member (423) enters the stitch length adjustment groove (4121) to position the zero point of the swing seat, the drive source (20) drives the output shaft (21) to drive the adjusting wheel (42) to rotate freely in the ring (441) of the connecting rod (44). At this time, the drive source (20) continues to operate, and the sliding member (423) provides the connecting rod (44) and the swing seat (43) with no swing source transmission. At this time, the sewing machine (10) commands the drive source (20) to perform the presser foot lifting action of the presser foot lifting mechanism (50) and the thread cutting action of the thread cutting mechanism (60).

6. A sewing machine with stitch length adjustment and a zero-position positioning swing seat according to claim 1, characterized in that, The drive source (20) has a needle length adjustment operating angle, a swing seat zero position positioning operating angle, a presser foot lifting operating angle, and a thread cutting operating angle. Each sewing action runs in its own operating angle, and the various operating angles do not interfere with each other. The drive source (20) drives the output shaft (21) to perform needle length adjustment, swing seat zero position positioning, presser foot lifting, and thread cutting actions in different time periods and in different operating angles.

7. A sewing machine with stitch length adjustment and a zero-position positioning swing seat according to claim 5, characterized in that, The wire-cutting mechanism (60) has a wire-cutting crank (61), a wire-cutting fork wheel (62), and a wire-cutting end actuator. A pusher (611) is provided at the eccentric position of the wire-cutting crank (61). The wire-cutting fork wheel (62) has a return rod (621) and a wire-cutting rod (622). The pusher (611) is located between the return rod (621) and the wire-cutting rod (622). The drive source (20) drives the pusher (611) to rotate and press down the wire-cutting rod (622), transmitting the wire-cutting force to the wire-cutting end actuator. The wire-cutting end actuator completes the wire-cutting action. After the wire-cutting is completed, the drive source (20) continues to rotate the pusher (611) to the return rod (621), and in turn, returns the return rod (621) to its original position, thus completing the entire wire-cutting process. The mechanism (60) is reset; the lifting foot mechanism (50) has a lifting foot cam (51), a lifting foot push rod (52) and a lifting foot end execution end. The drive source (20) drives the lifting foot cam (51) at the lifting foot running angle. The lifting foot cam (51) has an arc surface that is a free-rotating surface. The cam surface of the lifting foot cam (51) is a lifting surface for lifting foot action. The drive source (20) drives the output shaft (21) to rotate the lifting foot cam (51) to lift the lifting foot push rod (52). The lifting foot push rod (52) finally causes the lifting foot end execution end to perform the lifting foot action. The wire cutting crank (61) and the lifting foot cam (51) are mounted on the output shaft (21). The wire cutting crank (61) is located on the outermost side of the output shaft (21).

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