A sewing machine

Abstract

The application provides a sewing machine and particularly relates to the technical field of sewing machine manufacturing. The application drives the feed dog mechanism in the feed dog driving area by using the feed motor and the lift dog motor to realize that the feed dog has the feed function. The feed motor and / or the lift dog motor indirectly drives the feed dog of the feed dog mechanism in the idle area. In this case, the feed motor and / or the lift dog motor performs the thread cutting action and / or the presser foot lifting action. The sewing machine breaks the traditional technical scheme, cancels the traditional feed link, the lift dog link and the transmission cam on the main shaft, can manufacture the lift dog shaft to be shorter to reduce the manufacturing cost, cancels the original sewing machine vertical shaft, reduces the manufacturing cost of the sewing machine, improves the intelligent control level of the stitch length, and improves the sewing quality of the sewing machine. The sewing machine technology has high popularization and application value.

Description

TECHNICAL FIELD

[0001] The application provides a sewing machine, and particularly relates to the technical field of sewing machine manufacturing. BACKGROUND

[0002] In the driving mechanism of the sewing machine, the feed motor and the presser foot motor are provided with a main shaft motor on the head of the sewing machine, the main shaft motor is connected with an output main shaft, a transmission cam is fixed on the output main shaft, the main shaft motor drives the feed connecting rod and the presser foot connecting rod to move to provide the feed motion of the feed dog by the eccentric rotation of the cam. The feed connecting rod drives the feed shaft to rotate at a certain angle through the swing seat assembly, and the presser foot connecting rod drives the presser foot shaft to swing at a certain angle through the presser foot crank; the swing of the feed connecting rod and the feed shaft drives the feed dog frame to swing, thereby generating the forward and backward motion of the feed dog; the swing of the presser foot connecting rod and the presser foot shaft drives the presser foot fork on the presser foot shaft to swing, thereby generating the up and down motion of the feed dog; the combination of the forward and backward motion and the up and down motion forms the feed motion of the feed dog. The above-mentioned structure for providing the feed motion of the feed dog is complex, and the cost is also high.

[0003] For the swing seat of the stitch control, many enterprises have proposed intelligent control technical solutions for the feed stitch. A patent solution provides a feed shaft driving source, a connecting crank, a feed shaft, a feed dog frame and a feed dog, a swing rod, the feed shaft driving source has an output shaft, the output shaft is provided with the swing rod, the swing rod is hingedly connected with the connecting crank, the connecting crank is fixed on the feed shaft, the feed shaft is movably connected with the feed dog frame, and the feed dog frame is fixed with the feed dog. Actually, the solution drives the swing rod by using the feed shaft driving source to replace the original feed connecting rod of the sewing machine, adjusts the stitch of the stitch adjusting mechanism and positions the zero point of the zero position positioning mechanism, which has a positive stitch adjusting effect. However, the movement of the presser foot connecting rod still stays in the prior art, so that the up and down feed motion of the feed dog cannot reach the intelligent control level.

[0004] In addition, the main shaft motor is further provided with an umbrella gear on the output main shaft, the umbrella gear is provided with a vertical shaft and a lower shaft, so that the rotating hook runs under the driving of the main shaft motor, and the vertical shaft and the umbrella gear increase the manufacturing cost of the sewing machine. SUMMARY

[0005] In view of the defects of the above-mentioned complex structure of the sewing machine, the low intelligent control level and the high manufacturing cost, the application provides a sewing machine, a sewing machine is provided with a feed dog mechanism, the feed dog mechanism is driven by a feed motor and a presser foot motor, characterized in that the feed motor and the presser foot motor drive the feed dog mechanism in the feed dog driving area, and the feed motor and / or the presser foot motor indirectly push the feed dog of the feed dog mechanism in the idle area.

[0006] Preferably, the lifting tooth motor drives the lifting tooth shaft to drive the feed dog to swing back and forth repeatedly, the lifting tooth motor is connected with a lifting tooth front output shaft, a lifting tooth crank is fixed on the lifting tooth front output shaft, the lifting tooth crank is connected with a lifting tooth first connecting rod, the lifting tooth first connecting rod is connected with a lifting tooth second connecting rod and a lifting tooth third connecting rod, the lifting tooth third connecting rod is connected with a lifting tooth rear cam, the lifting tooth rear cam is fixed on the lifting tooth shaft, a lifting tooth front cam is connected with the lifting tooth shaft, and a feed dog holder is mechanically matched with the lifting tooth front cam, and the feed dog holder is fixed with a feed dog.

[0007] Preferably, the feed dog motor drives the feed dog shaft to swing back and forth repeatedly, a feed dog crank one is fixed on a feed dog output shaft connected with the feed dog motor, the feed dog crank one is connected with a feed dog connecting rod, the feed dog connecting rod is connected with a feed dog crank two, the feed dog crank two is fixed on the feed dog shaft, a feed dog seat is fixed on the feed dog shaft, a feed dog holder is arranged on the feed dog seat, and the feed dog holder is fixed with a feed dog.

[0008] Preferably, the lifting tooth first connecting rod is connected with the lifting tooth second connecting rod at a connecting end, and the lifting tooth third connecting rod is connected with the lifting tooth second connecting rod at the connecting end, and the connecting end is in concentric relationship with the lifting tooth front output shaft.

[0009] Preferably, the lifting tooth front cam has a movable rod located on one side of an eccentric position of the lifting tooth front cam, and the movable rod is matched in a socket of the feed dog holder.

[0010] Preferably, the lifting tooth rear cam has a connecting part located on one side of an eccentric position of the lifting tooth rear cam, the lifting tooth third connecting rod is connected with the connecting part of the lifting tooth rear cam, a fixed end of the lifting tooth second connecting rod is connected with a support shaft, and the fixed end of the lifting tooth second connecting rod is movably connected with the support shaft, and the other end of the support shaft is fixed on a support shaft support of the sewing machine.

[0011] Preferably, the feed dog motor and the lifting tooth motor are installed and fixed under a base plate of the sewing machine, the feed dog motor and the lifting tooth motor are fixed on both sides of the base plate, and the feed dog motor and the lifting tooth motor are step motors.

[0012] Preferably, the sewing machine further has a rotating shuttle mechanism, the rotating shuttle mechanism comprises a rotating shuttle motor, a lower shaft and a shuttle core, the rotating shuttle motor drives the rotating shuttle to perform a thread feeding work, the rotating shuttle motor is installed under the base plate of the sewing machine, and the rotating shuttle motor is located between the feed dog motor and the lifting tooth motor.

[0013] Preferably, the sewing machine further has a thread cutting and lifting presser foot mechanism, the feed dog motor and / or the lifting tooth motor performs a thread cutting action and / or a lifting presser foot action of the thread cutting and lifting presser foot mechanism when the feed dog motor and / or the lifting tooth motor enters an idle area.

[0014] Preferably, the thread trimming presser foot mechanism has a presser foot lifting motor, a thread trimming crank and a thread trimming fork wheel, the thread trimming crank is installed on the front output shaft connected with the presser foot lifting motor, the thread trimming crank has a pusher, the pusher is arranged at the eccentric position of the end of the thread trimming crank, the thread trimming fork wheel has a thread trimming return rod and a thread trimming push rod, the pusher is arranged between the thread trimming return rod and the thread trimming push rod, the thread trimming presser foot mechanism further has a presser foot lifting motor, a presser foot cam, a presser foot lifting rod, a presser foot lever and a presser foot lifting rod, the presser foot cam is fixed on the rear output shaft connected with the presser foot lifting motor, the presser foot lever is fixed below the base plate of the sewing machine, and the two ends of the presser foot lever are located below the presser foot cam and the presser foot lifting rod.

[0015] Compared with the prior art, the sewing machine provided in the application drives the feed dog mechanism in the feed dog driving area by using the feed dog motor and the presser foot lifting motor to realize the feed dog function of the feed dog, indirectly drives the feed dog of the feed dog mechanism by using the feed dog motor and / or the presser foot lifting motor in the idle area, and performs the thread trimming action and / or the presser foot lifting action by using the feed dog motor and / or the presser foot lifting motor in this case. The sewing machine provided in the application breaks the traditional technical solution, cancels the traditional feed link, the presser foot lifting link and the transmission cam on the main shaft, can manufacture the presser foot shaft to be shorter to reduce the manufacturing cost, cancels the vertical shaft of the original sewing machine, reduces the manufacturing cost of the sewing machine and improves the intelligent control level of the stitch length, thereby improving the sewing quality of the sewing machine, and the sewing machine technology provided in the application has high popularization and application value. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A structure schematic diagram of a sewing machine is shown;

[0017] Figure 2 A feed dog mechanism and a rotating hook mechanism of a sewing machine are shown;

[0018] Figure 3 A front and rear feed dog assembly of a sewing machine is shown;

[0019] Figure 4 A front and rear feed dog assembly of a sewing machine is shown;

[0020] Figure 5 A front and rear feed dog assembly of a sewing machine is shown;

[0021] Figure 6 A feed dog frame connection schematic diagram of a front and rear feed dog assembly of a sewing machine is shown;

[0022] Figure 7 A front and rear feed dog assembly of a sewing machine is shown;

[0023] Figure 8The diagram shown is a structural diagram of a thread-cutting and presser foot lifting mechanism for a sewing machine.

[0024] Figure 9 The diagram shows a sewing machine thread-cutting crank and thread-cutting fork wheel;

[0025] Figure 10 The diagram shown is a schematic diagram of a sewing machine embodiment 2 with a feed motor driving a feed dog mechanism.

[0026] Figure 11 The diagram shown is a schematic diagram of a sewing machine embodiment 2, which uses a fabric feeding motor to drive a thread cutting and presser foot lifting mechanism.

[0027] The reference numerals in the attached drawings are as follows: base plate 11, support shaft bracket 12, front output shaft support frame for lifting teeth 13, feed motor 21, feed output shaft 211, feed shaft 22, feed crank one 23, feed connecting rod 24, feed crank two 25, feed tooth seat 26, feed tooth frame 27, insertion port 271, feed tooth 28, needle plate flat surface 29, lifting motor 31, front output shaft for lifting teeth 311, rear output shaft for lifting teeth 312, lifting shaft 32, lifting crank 33, first lifting connecting rod for lifting teeth 34, second lifting connecting rod for lifting teeth 35. Hinged end 351, fixed end 352, third link for lifting teeth 36, rear cam for lifting teeth 37, connecting part 371, front cam for lifting teeth 38, movable rod 381, support shaft 39, rotary shuttle motor 41, lower shaft 42, bobbin 43, thread cutting crank 51, pusher 511, thread cutting fork wheel 52, thread cutting return rod 521, thread cutting push rod 522, push link 523, fixed shaft 53, lifting pressure foot cam 54, idle surface 541, pressure foot lifting surface 542, lifting pressure foot lever 55, lifting pressure foot top rod 56. Detailed Implementation

[0028] The following is in conjunction with the appendix Figures 1-11 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.

[0029] Example 1

[0030] The sewing machine of the present application has a feed dog mechanism, a rotating shuttle mechanism, a thread trimming and presser foot lifting mechanism, and a control system. The present application aims to promote a sewing machine with efficient lubrication-free mechanical transmission. In addition to the above-mentioned mechanisms and systems, the present sewing machine also has all other sewing functions that can realize normal sewing work. The feed dog mechanism refers to the feed dog 28 and the transmission parts and power devices that operate the feed dog 28 under the control of the control system. The sewing machine of the present application drives the feed dog 28 to perform the feed work by the feed motor 21 and the lift motor 31 of the feed dog mechanism under the control of the control system, and simultaneously drives the rotating shuttle to perform the thread trimming work by the rotating shuttle motor 41 of the rotating shuttle mechanism. After completing the sewing work, the thread trimming and presser foot lifting actions of the thread trimming and presser foot lifting mechanism are performed and completed by the lift motor 31 of the feed dog mechanism.

[0031] The feed dog mechanism described above has a feed motor 21, a lift motor 31, a feed dog 28, and various components that indirectly drive the feed dog 28 between the feed motor 21 and the lift motor 31. These components are the main components of the feed dog 28 that have the feed action assembly function. The feed motor 21 and the lift motor 31 are installed and fixed below the base plate 11 of the sewing machine. The feed motor 21 and the lift motor 31 are fixed on both sides of the base plate 11. The feed motor 21 and the lift motor 31 are electrically connected to the control system of the sewing machine. Here, the feed motor 21 and the lift motor 31 preferably use a stepping motor.

[0032] The operation angle of the feed motor 21 and the lift motor 31 of the present application consists of a feed dog driving area and an idle area. The feed dog driving area is used to drive the feed dog mechanism by the feed motor 21 and the lift motor 31. The idle area is used to avoid the power output by the lift motor 31 from acting on the feed dog mechanism. In other words, the lift motor 31 entering the idle area will not indirectly push the feed dog 28 through various components. Under the control of the control system of the sewing machine, the feed motor 21 and the lift motor 31 simultaneously start driving the swing source transmission to the feed dog 28 in the feed dog driving area. Both are operated in a repeated back-and-forth swing manner to indirectly transmit the swing source to the feed dog 28 through the feed shaft 22, the lift shaft 32, and many other components. After completing the driving work, the feed motor 21 and the lift motor 31 simultaneously stop driving in the feed dog driving area. The feed motor 21 and the lift motor 31 work in coordination under the control of the control system, so that the feed dog 28 has complete sewing feed action, and the normal sewing work of the sewing machine is realized.

[0033] The above feed dog mechanism includes up-and-down feed dog assembly and front-and-back feed dog assembly. The up-and-down feed dog assembly includes lift dog motor 31, lift dog shaft 32, lift dog crank 33, lift dog first connecting rod 34, lift dog second connecting rod 35, lift dog third connecting rod 36, lift dog rear cam 37, lift dog front cam 38, feed dog seat 26, feed dog holder 27 and feed dog 28. Generally, the lift dog motor 31 drives the lift dog shaft 32 to indirectly drive the feed dog 28 to swing back and forth repeatedly, so that the feed dog 28 has up-and-down feed dog action. The power output shaft connected with the lift dog motor 31 is the lift dog front output shaft 311. The lift dog crank 33 is fixed on the lift dog front output shaft 311, the other end of the lift dog crank 33 is hinged to the lift dog first connecting rod 34, the other end of the lift dog first connecting rod 34 is hinged to the hinged end 351 of the lift dog second connecting rod 35, the fixed end 352 of the lift dog second connecting rod 35 is connected with the support shaft 39, the fixed end 352 of the lift dog second connecting rod 35 is movably connected on the support shaft 39 so that the lift dog second connecting rod 35 can swing, the other end of the support shaft 39 is fixed on the support shaft support 12 of the sewing machine. The hinged end 351 of the second connecting rod 35 is also hinged to the lift dog third connecting rod 36, forming the lift dog first connecting rod 34, the lift dog third connecting rod 36 and the second connecting rod 35 hinged together. The other end of the lift dog third connecting rod 36 is hinged to the connecting part 371 of the lift dog rear cam 37, the connecting part 371 is located on the side of the eccentric position of the lift dog rear cam 37. The lift dog motor 31 drives the lift dog crank 33 on the lift dog front output shaft 311 to swing back and forth repeatedly, the lift dog crank 33 drives the lift dog first connecting rod 34, the lift dog second connecting rod 35 and the lift dog third connecting rod 36 to swing back and forth, prompting the lift dog rear cam 37 to swing at the same angle, here, the lift dog second connecting rod 35 plays a role in assisting the lift dog first connecting rod 34 and the lift dog third connecting rod 36 to swing repeatedly.

[0034] The lift dog rear cam 37 is fixed on the side of the lift dog shaft 32 close to the lift dog motor 31; on the side of the lift dog shaft 32 close to the feed dog 28, the lift dog front cam 38 is connected on the lift dog shaft 32, and the lift dog front cam 38 mechanically cooperates with the feed dog holder 27. The lift dog front cam 38 has a movable rod 381, the movable rod 381 is located on the side of the eccentric position of the lift dog front cam 38, and the movable rod 381 can swing axially under the repeated swing of the lift dog shaft 32. The movable rod 381 is matched in the socket 271 of the feed dog holder 27. Under the repeated swing of the lift dog front cam 38, the movable rod 381 moves repeatedly inside the socket 271, so that the side of the socket 271 of the feed dog holder 27 fixed on the feed dog seat 26 has up-and-down movement, and the feed dog 28 fixed on the feed dog holder 27 has up-and-down feed dog action.

[0035] In addition, the center position of the hinge end 351 is arranged in a concentric relationship with the lifting tooth front output shaft 311. After the lifting tooth motor 31 stops transmitting the up-and-down feeding action power to the feeding tooth 28, the lifting tooth motor 31 needs to leave the feeding tooth driving area and enter the idling area. When the lifting tooth motor 31 rotates the lifting tooth crank 33, the lifting tooth first connecting rod 34 acts on the lifting tooth second connecting rod 35, so that the center position of the hinge end 351 of the lifting tooth second connecting rod 35 is in a concentric position state with the lifting tooth front output shaft 311. In this case, the lifting tooth motor 31 continues to rotate the lifting tooth crank 33, which does not generate a pushing action on the lifting tooth second connecting rod 35 and the lifting tooth third connecting rod 36. The lifting tooth motor 31 of the up-and-down feeding assembly enters the idling area from the working area of the feeding tooth mechanism of the feeding tooth 28, effectively avoiding the pushing influence of the power of the lifting tooth motor 31 on the up-and-down feeding assembly. The lifting tooth motor 31 can utilize the idling area to perform the cutting line lifting presser foot mechanism cutting line action and lifting presser foot action of the lifting tooth front output shaft 311 and the lifting tooth rear output shaft 312 connected to the lifting tooth motor 31.

[0036] In the front-and-back feeding assembly, the feeding motor 21, the feeding shaft 22, the feeding crank one 23, the feeding connecting rod 24, the feeding crank two 25, the feeding tooth seat 26, the feeding tooth frame 27, and the feeding tooth 28 are included. In the present scheme, the feeding motor 21 drives the feeding shaft 22 in a repeated back-and-forth swinging manner, indirectly causes the feeding tooth 28 to repeatedly swing, and makes the feeding tooth 28 have a front-and-back feeding action. Specifically, the output end of the feeding motor 21 is a feeding output shaft 211, the feeding crank one 23 is fixed on the feeding output shaft 211, the other end of the feeding crank one 23 is hinged to the feeding connecting rod 24, the other end of the feeding connecting rod 24 is hinged to the feeding crank two 25, and the feeding crank two 25 is fixed on the feeding shaft 22 close to the side of the feeding motor 21. The feeding shaft 22 is connected and fixed with the feeding tooth seat 26 on the front end close to the feeding tooth 28, the feeding tooth seat 26 is connected and arranged with the feeding tooth frame 27, and the feeding tooth frame 27 is fixed with the feeding tooth 28, so that the feeding tooth 28 has a repeated front-and-back movement action, and the feeding tooth 28 fixed on the feeding tooth frame 27 has a repeated front-and-back feeding action. Here, the feeding crank one 23, the feeding connecting rod 24, and the feeding crank two 25 indirectly make the feeding tooth 28 have a repeated front-and-back feeding action through the repeated back-and-forth swinging drive of the feeding motor 21.

[0037] The up-and-down feeding motion of the feed dog 28 and the forward-and-backward feeding motion of the feed dog 28 are combined, so that the feed dog 28 with the up-and-down feeding motion and the forward-and-backward feeding motion combined has the complete feeding function of the sewing machine, and normal sewing can be performed. The sewing machine breaks the traditional technical solution of driving the feed dog by the main shaft motor, cancels the original feeding link, the up-and-down link, the transmission cam on the main shaft, and the linkage gear set, so that the structure of the sewing machine is stable and simple. In addition, the up-and-down shaft 32 and the feed shaft 22 can be made shorter to reduce the manufacturing cost. At the same time, after the swing seat, a traditional important component for adjusting the stitch length, is cancelled, the stitch length required for the feed dog 28 to sew is controlled and adjusted by the control system, and the intelligent level of sewing is further improved. The sewing machine of the present application has all the functions of the swing seat. Since the repeated back-and-forth swinging mode of the feed motor 21 and the up-and-down motor 31 is preset by the control system, the feeding motion of the feed dog 28 is always at a constant stitch length for sewing, that is, the stitch length under the feeding and the up-and-down is in a constant state, overcoming the deviation of the stitch length of the existing sewing machine, effectively improving the sewing quality and the stability of the sewing work, which also reflects the advantage of the sewing machine of the present application having multiple adjustable stitch lengths, that is, the stitch length of the sewing machine can be adjusted at will in the stopped state. In addition, the feed motor 21 and the up-and-down motor 31 start driving and stop driving at the same time under the control of the control system, to achieve the purpose of coordinated feeding motion of the feed dog mechanism, avoid uncoordinated sewing action of the feed dog 28 or only feeding motion without up-and-down motion, or only up-and-down motion without feeding motion, and improve the stability of the sewing machine.

[0038] The sewing machine of the present application also has a zero-stitch-length positioning function, that is, the function of positioning the feed dog 28 below the flat surface 29 of the needle plate. The up-and-down motor 31 drives the up-and-down crank 33 fixed on the up-and-down front output shaft 311, which indirectly positions the feed dog 28 below the flat surface 29 of the needle plate through various components, thereby overcoming the adverse effects of the existing sewing machine caused by the feed dog 28 being above the flat surface 29 of the needle plate, and making the sewing work proceed smoothly and improving the sewing quality.

[0039] The rotating hook mechanism of the present application comprises a rotating hook motor 41, a lower shaft 42 and a hook core 43. The rotating hook motor 41 is installed below the base plate 11 of the sewing machine and between the feed motor 21 and the presser foot lifting motor 31. The rotating hook motor 41 is connected to the lower shaft 42 and drives the hook core 43 under the control of the control system to complete the rotating hook thread delivery work of the rotating hook mechanism, which is synchronized with the feed dog thread delivery work of the feed dog mechanism, and there is no difference from the prior art. The rotating hook motor 41 directly drives the lower shaft 42 to perform the rotating hook thread delivery work of the hook core 43, which cancels the original vertical shaft and transmission gear of the sewing machine and shortens the length of the lower shaft, thereby reducing the manufacturing cost of the sewing machine in production. In addition, the rotating hook motor 41 uses a stepping motor, which is conducive to the control of the rotating hook thread delivery work by the control system, thereby improving the intelligent control level of the sewing machine and improving the sewing quality.

[0040] After the presser foot lifting motor 31 enters the idling area, the presser foot lifting motor 31 of the present application does not install the parts of the thread trimming and presser foot lifting mechanism on the front output shaft 311 and the rear output shaft 312, at which time the thread trimming and presser foot lifting mechanism of the sewing machine performs the thread trimming and presser foot lifting actions by the traditional electromagnet.

[0041] In addition, the thread trimming and presser foot lifting mechanism is also provided with the following several situations. In the thread trimming and presser foot lifting mechanism, the thread trimming crank 51 is installed on the front output shaft 311 connected to the presser foot lifting motor 31, the thread trimming crank 51 is fixed between the presser foot lifting motor 31 and the presser foot lifting crank 33, and the thread trimming crank 51 and the presser foot lifting crank 33 are further provided with the front output shaft support frame 13 of the sewing machine, a bearing is arranged between the front output shaft support frame 13 and the front output shaft 311, and the front output shaft support frame 13 is arranged to make the presser foot lifting motor 31 have a fixed and reliable structure when it is running. The presser foot cam 54 is fixed on the rear output shaft 312 connected to the presser foot lifting motor 31.

[0042] Here, in addition to the above-mentioned thread trimming crank 51 installed on the front output shaft 311 connected to the presser foot lifting motor 31 and the presser foot cam 54 installed on the rear output shaft 312, it is pointed out that the front output shaft 311 and the rear output shaft 312 connected to the presser foot lifting motor 31 can not be installed with the thread trimming crank 51 and the presser foot cam 54, and the thread trimming and presser foot lifting actions are performed by the traditional electromagnet of the sewing machine. In addition, the presser foot lifting motor 31 is connected to the front output shaft 311, and the presser foot cam 54 is not installed on the rear output shaft 312, and the presser foot is executed by the traditional electromagnet, or the presser foot lifting motor 31 is connected to the rear output shaft 312, and the presser foot cam 54 is not installed on the front output shaft 311, and the thread trimming action is executed by the electromagnet. In short, there are many ways to realize the thread trimming and presser foot lifting actions of the thread trimming and presser foot lifting mechanism.

[0043] The aforementioned thread-cutting and presser foot lifting mechanism includes a tooth-lifting motor 31, a thread-cutting crank 51, and a thread-cutting fork wheel 52. The thread-cutting crank 51 is mounted on the tooth-lifting front output shaft 311 connected to the tooth-lifting motor 31. The thread-cutting crank 51 has a pusher 511, which is located at an eccentric position at the end of the thread-cutting crank 51. The pusher 511 pushes the thread-cutting fork wheel 52 to achieve the thread-cutting action. The thread-cutting fork wheel 52 has a thread-cutting return rod 521 and a thread-cutting push rod 522. The pusher 511 is located between the thread-cutting return rod 521 and the thread-cutting push rod 522 to prevent the power from being transmitted to the thread-cutting return rod 521 or the thread-cutting push rod 522 when the tooth-lifting motor 31 drives the feed tooth mechanism. When the lifting motor 31 drives the thread-cutting crank 51 of the lifting front output shaft 311, the pusher 511 pushes the thread-cutting push rod 522 and the push connecting rod 523, causing the subsequent thread-cutting actuator to perform the thread-cutting action. The thread-cutting fork wheel 52 is positioned by the fixed shaft 53, so that the thread-cutting action of the thread-cutting fork wheel 52 has a stable rotation structure. The fixed shaft 53 is fixedly connected to the lifting front output shaft support frame 13 of the sewing machine.

[0044] Furthermore, the thread-cutting and presser foot-lifting actions in this application are performed in the idle zone. The thread can be cut at the feed dog 28 below the needle plate plane 29 to minimize the excess thread. This timing is selected by the control system during the idle zone. Similarly, the presser foot-lifting action is also selected by the control system during the idle zone, making the presser foot-lifting action more consistent with the sewing process and timing. Relatively speaking, the thread-cutting and presser foot-lifting actions, selected by the control system, offer the highest degree of optimal timing, increasing the requirements on the sewing machine.

[0045] After the thread-cutting action is completed, the sewing machine's control system immediately commands the tooth-lifting motor 31 to lift the presser foot.

[0046] The thread trimming and presser foot lifting mechanism further comprises a presser foot lifting motor 31, a presser foot lifting cam 54, a presser foot lifting rod 56, a presser foot lifting lever 55 and the like. The presser foot lifting cam 54 is fixed on the rear output shaft 312 of the presser foot lifting motor 31. The presser foot lifting lever 55 is fixed under the base plate 11 of the sewing machine and located at the rear side of the presser foot lifting motor 31. The two ends of the presser foot lifting lever 55 are located below the presser foot lifting cam 54 and the presser foot lifting rod 56. The presser foot lifting motor 31 drives the presser foot lifting cam 54 to press down or release the presser foot lifting rod 56 to lift or lower the presser foot lifting rod 56. The presser foot lifting cam 54 is actually a cam. The presser foot lifting cam 54 has an idle surface 541 and a presser foot lifting surface 542. The idle surface 541 and the presser foot lifting surface 542 can alternately act on the presser foot lifting lever 55 under the drive of the presser foot lifting motor 31. The idle surface 541 is used to avoid power transmission to the presser foot lifting lever 55 and the presser foot lifting rod 56 when the thread trimming crank 51 on the thread trimming and presser foot lifting mechanism is driven by the presser foot lifting motor 31.

[0047] The presser foot lifting surface 542 is the cam portion of the presser foot lifting cam 54. The presser foot lifting cam 54 rotates from the idle surface 541 to the presser foot lifting surface 542 under the drive of the presser foot lifting motor 31, so that the presser foot lifting surface 542 gradually acts on the presser foot lifting rod 56 through the presser foot lifting lever 55 to lift the presser foot lifting rod 56. The highest point of the cam portion of the presser foot lifting surface 542 abuts against the presser foot lifting lever 55, i.e. the presser foot lifting rod 56 is in the highest position, and the presser foot lifting state is the lifting state. The highest point of the cam portion is the highest point of the cam arc surface of the presser foot lifting surface 542.

[0048] After the thread trimming and presser foot lifting are completed, the presser foot lifting motor 31 drives the thread trimming crank 51 to continue rotating through the thread trimming and presser foot lifting mechanism, so that the pusher 511 acts on the thread trimming return rod 521 until it returns to the original position. At the same time, the presser foot lifting cam 54 rotates from the highest point of the presser foot lifting to the idle surface 541 within a predetermined time set by the control system, and the presser foot lifting rod 56 is lowered through the presser foot lifting lever 55 to realize the presser foot lifting action.

[0049] Embodiment Two

[0050] The feed dog mechanism of the second embodiment and the first embodiment is also driven by the feed motor 21 and the lift dog motor 31, and the difference is that the up and down feed action of the feed dog 28 of the feed dog mechanism is driven by the feed motor 21, and the front and rear feed action of the feed dog 28 of the feed dog mechanism is driven by the lift dog motor 31. Among them, the feed motor 21 drives the feed dog 28 of the feed dog mechanism to generate the up and down feed action, and the structure of the lift dog motor 31 driving the feed dog 28 of the feed dog mechanism to generate the up and down feed action in the first embodiment is the same. The lift dog motor 31 drives the feed dog 28 of the feed dog mechanism to generate the front and rear feed action, and the structure of the feed motor 21 driving the feed dog 28 of the feed dog mechanism to generate the front and rear feed action in the first embodiment is the same, and the specific repeated same parts are not marked. Figure 10 Figure 11 The specific repeated same parts are not marked.

[0051] The motor running angle of the feed motor 21 and the lift dog motor 31 of the present application is also composed of a feed dog driving area and an idling area. The feed motor 21 and the lift dog motor 31 drive the feed dog mechanism in the feed dog driving area, and the lift dog motor 31 uses the idling area to perform the cutting line action and the lifting foot action of the cutting line lifting foot mechanism. The feed motor 21 enters the idling area and indirectly uses each part to push the feed dog 28 of the feed dog mechanism. In this idling area, the front output shaft and the rear output shaft connected by the feed motor 21 perform the cutting line action and the lifting foot action of the cutting line lifting foot mechanism.

[0052] Of course, the front output shaft connected by the feed motor 21 is provided with a cutting line crank 51, and the rear output shaft is not provided with a lifting foot cam 54, and the lifting foot is performed by a traditional electromagnet, or the rear output shaft connected by the feed motor 21 is provided with a lifting foot cam 54, and the front output shaft is not provided with a cutting line crank 51, and the cutting line action is performed by an electromagnet, or the rear output shaft connected by the feed motor 21 is not provided with a lifting foot cam 54 and a cutting line crank 51, or the front output shaft connected by the feed motor 21 is not provided with a cutting line crank 51, and the rear output shaft is not provided with a lifting foot cam 54, and the feed motor 21 does not perform the cutting line and lifting foot action.

[0053] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields is also included in the patent protection scope of the present application.

Claims

1. A sewing machine having a feed dog mechanism driven by a feed motor and a lift dog motor, characterized by, The feed motor and the lift tooth motor drive the feed tooth mechanism in the feed tooth driving area, and the feed motor or the lift tooth motor indirectly pushes the feed tooth of the feed tooth mechanism when entering the idle area; The lift tooth motor drives the lift tooth shaft to drive the feed tooth to swing back and forth repeatedly, the lift tooth motor is connected with a lift tooth crank, the lift tooth crank is connected with a first lift tooth connecting rod, the first lift tooth connecting rod is connected with a second lift tooth connecting rod and a third lift tooth connecting rod, the third lift tooth connecting rod is connected with a lift tooth rear cam, the lift tooth rear cam is fixed on the lift tooth shaft, the lift tooth shaft is connected with a lift tooth front cam, and the lift tooth front cam is matched with the feed tooth holder. The lift tooth motor is further connected with a thread cutting and presser foot lifting mechanism, the thread cutting and presser foot lifting mechanism is provided with a thread cutting crank and a thread cutting fork wheel, the thread cutting crank is installed on the front output shaft of the lift tooth motor, the thread cutting crank is provided with a pushing piece, the pushing piece is arranged at an eccentric position of the thread cutting crank, the thread cutting fork wheel is provided with a thread cutting return rod and a thread cutting pushing rod, and the pushing piece is arranged between the thread cutting return rod and the thread cutting pushing rod. The thread cutting and presser foot lifting mechanism is further provided with a lift tooth motor, a presser foot cam, a presser foot lifting rod, a presser foot lever and a presser foot lifting rod, the presser foot cam is fixed on the rear output shaft of the lift tooth motor, the presser foot lever is fixed below the base plate of the sewing machine, and the two ends of the presser foot lever are located below the presser foot cam and the presser foot lifting rod.

2. The sewing machine of claim 1, wherein The feed motor drives the feed shaft to swing back and forth repeatedly, the feed motor is connected with a feed output shaft, the feed output shaft is fixed with a feed crank one, the feed crank one is connected with a feed connecting rod, the feed connecting rod is connected with a feed crank two, the feed crank two is fixed on the feed shaft, the feed shaft is fixed with a feed tooth seat, the feed tooth seat is connected with a feed tooth holder, and the feed tooth holder is fixed with a feed tooth.

3. The sewing machine of claim 1, wherein The first lift tooth connecting rod is connected with the second lift tooth connecting rod, and the connecting end of the first lift tooth connecting rod is connected with the third lift tooth connecting rod.

4. The sewing machine of claim 1, wherein The lift tooth front cam is provided with a movable rod, the movable rod is arranged at an eccentric position of the lift tooth front cam, and the movable rod is matched in a socket of the feed tooth holder.

5. The sewing machine of claim 1, wherein The lift tooth rear cam is provided with a connecting portion, the connecting portion is arranged at an eccentric position of the lift tooth rear cam, the third lift tooth connecting rod is connected with the connecting portion of the lift tooth rear cam, the second lift tooth connecting rod is connected with a fixed end and a supporting shaft, the fixed end of the second lift tooth connecting rod is movably connected with the supporting shaft, and the other end of the supporting shaft is fixed on a supporting shaft support of the sewing machine.

6. The sewing machine of claim 1, wherein, The feed motor and the lift tooth motor are fixed below the base plate of the sewing machine, the feed motor and the lift tooth motor are fixed on the two sides of the base plate, and the feed motor and the lift tooth motor are step motors.

7. The sewing machine of claim 1, wherein The rotary hook mechanism is further provided with a rotary hook motor, a lower shaft and a bobbin, the rotary hook motor drives the rotary hook to perform the thread feeding work, the rotary hook motor is installed below the base plate of the sewing machine, and the rotary hook motor is located between the feed motor and the lift tooth motor.

Images