A linkage drive structure for a pattern sewing machine

Abstract

The present invention relates to an interlocking transmission structure for a pattern sewing machine. In this interlocking transmission structure, the power of the main shaft is efficiently transmitted to the auxiliary shaft through the first and second power dividing shafts of the power divider. Moreover, a crank whose first end is rotatably connected to the first power dividing shaft can, with the support of the second power dividing shaft, transmit its rotational force to the auxiliary shaft, causing the auxiliary shaft to drive the shuttle to reciprocate relative to the main shaft synchronously, thereby realizing the thread picking function. In addition, the power dividing shafts extend in the same direction as the main shaft and the auxiliary shaft, making each transmission part of the interlocking transmission structure clear and distinct, which is very conducive to maintenance. And when it is necessary to change the thread picking mode from the shuttle to the rotary hook, it only needs to remove the crank and install gears with corresponding gear ratios on the first and second power dividing shafts, and efficient replacement can be achieved without any complex disassembly and assembly.

Description

Technical Field

[0001] The present invention relates to the field of sewing equipment, and more particularly to a linkage transmission structure for a pattern sewing machine. Background Art

[0002] To meet the thread take-up requirements during sewing of a pattern sewing machine, the vast majority of pattern sewing machines are provided with a corresponding rotating shuttle or oscillating shuttle mechanism. Usually, a servo motor is used as the power source. By controlling the forward and reverse rotation of the servo motor within a set angular range and through a series of complex transmissions, the power is transmitted to the oscillating shuttle to directly achieve the reciprocating rotation and swing of the oscillating shuttle.

[0003] For example, the Chinese utility model patent with the patent number CN201220126340.5 discloses a "Crank and Connecting Rod Type Oscillating Shuttle Driving Mechanism for an Embroidery Machine", which includes a base, an oscillating shuttle member and a driving device. The base is a cube box divided into an inner box and an outer box by rib plates. A pair of connecting arms extend from the inner box. The oscillating shuttle member is installed under the connecting arms, and its rotating shaft passes through the inner box and the rib plates and extends into the outer box. The driving device includes a transmission pinion installed on the extended end of the rotating shaft and a transmission shaft perpendicular to the rotating shaft and avoiding each other. The end of the transmission shaft extends out of the inner box and is driven by an external power source. There are also a driving bevel gear on the transmission shaft, a connecting rod driving device and a sector rotating and swinging gear installed on the rib plates. The connecting rod driving device includes a driven bevel gear, an output shaft, a crank and a connecting rod connected thereto. The connecting rod drives the sector rotating and swinging gear to reciprocate within a set angular range, so that it meshes with the transmission pinion to drive the oscillating shuttle member.

[0004] In the above mechanism, the transmission structure is complex. Since the power source for the oscillation of the oscillating shuttle comes from the main shaft, multiple transmission components are required to achieve power transmission. The axes of rotating elements such as pinions and sector gears intersect at multiple points, which means that the power transmission direction changes multiple times between the elements, greatly increasing the energy loss. And due to the change of the transmission direction, the contact between components is increased, affecting the service life and being unfavorable for maintenance. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a linkage transmission structure for a pattern sewing machine with a simple structure and direct power transmission in view of the current situation of the prior art.

[0006] The second technical problem to be solved by the present invention is to provide a linkage transmission structure for a pattern sewing machine that can effectively adjust the gap between the sector rotating and swinging gear and the tooth part of the connecting head in view of the current situation of the prior art.

[0007] The technical solution adopted by the present invention to solve the above first technical problem is as follows: A linkage transmission structure for a pattern sewing machine, comprising:

[0008] A main shaft;

[0009] A driver, arranged adjacent to the first end of the main shaft, and its power output end is drivingly connected to the main shaft, thereby driving the main shaft to rotate about its own axis;

[0010] A secondary shaft, extending in the same direction as the main shaft, and a shuttle is provided at its second end;

[0011] A power divider, arranged adjacent to the secondary shaft, including a first power dividing shaft and a second power dividing shaft arranged side by side. Both the first power dividing shaft and the second power dividing shaft extend in the same direction as the main shaft and the secondary shaft. Among them, the first power dividing shaft is linked with the main shaft, and the second power dividing shaft is arranged adjacent to the secondary shaft;

[0012] A crank, with its first end rotatably connected to the first power dividing shaft and its second end drivingly connected to the secondary shaft. Under the rotational action of the first power dividing shaft, the crank intermittently acts on the secondary shaft, so that the secondary shaft drives the shuttle to reciprocate relative to the main shaft synchronously.

[0013] The sector swing gear can achieve power transmission in different positions. Preferably, the power divider is arranged below the secondary shaft. The crank extends upward at the top of its second end with a sector swing gear, which acts on the secondary shaft and can drive the secondary shaft to swing. The secondary shaft is provided with a tooth portion meshing with the sector swing gear at the corresponding position. Such a design form of the sector swing gear makes the arc tooth portion of the sector swing gear always extend upward and swing within a certain range, avoiding the situation of lateral extension or downward extension. Therefore, no matter how the power source is arranged, the center of gravity of the entire sector swing gear always remains on the secondary shaft and will not shift significantly, avoiding excessive local wear of the gear caused by uneven force in the above other situations and ensuring the service life.

[0014] To ensure the sector swing gear and drive the secondary shaft to swing, preferably, a connecting head is provided on the secondary shaft, the tooth portion is arranged on the outer wall of the connecting head, and a retaining edge for restricting the sector swing gear from disengaging from the connecting head is also provided on the connecting head.

[0015] The swing can be achieved by setting different positions. One form is eccentricity. Therefore, preferably, the crank is eccentrically connected to the first power dividing shaft.

[0016] To ensure that the power of the main shaft can be transmitted to the first power dividing shaft, a first transmission wheel is provided on the first power dividing shaft, a second transmission wheel is provided on the main shaft, and the first power dividing shaft is linked by a transmission belt sequentially wound around the first transmission wheel and the second transmission wheel.

[0017] The above-mentioned components work in an oil pressure environment. Preferably, the linkage transmission structure further includes a transfer case. The interior of the transfer case is hollow to form an oil pressure chamber. The first transfer shaft and the second transfer shaft are both arranged in the oil pressure chamber, and the first end of the countershaft extends into the oil pressure chamber.

[0018] To ensure that the swing of the sector swing gear is not affected by the outside world, preferably, a partition is arranged in the transfer case to divide the oil pressure chamber into a first chamber and a second chamber. The first transmission wheel is arranged in the first chamber, and the crank and the sector swing gear are both arranged in the second chamber.

[0019] To further solve the above-mentioned second technical problem, the technical solution adopted by the present invention is that the linkage transmission structure for the pattern sewing machine further includes a backlash elimination structure for adjusting the clearance between the sector swing gear and the tooth part of the connecting head. The backlash elimination structure includes an eccentric bushing and a backlash elimination hole opened on the partition. The eccentric bushing is sleeved on the periphery of the second transfer shaft and embedded in the backlash elimination hole. Since the eccentric bushing itself has an inner ring and an outer ring, the outer ring is fixed to the backlash elimination hole, and the inner wall of the outer ring is an eccentric structure. In this way, the inner ring connected to the second transfer shaft can trace and move on the inner wall of the outer ring. It is precisely because the circumferential clearance between the inner ring and the outer ring can be adjusted actively. When the cooperation between the sector swing gear and the tooth part is too tight or too loose, the second transfer shaft can drive the sector swing gear to move synchronously with the movement of the inner ring, thereby providing a certain amount of movement allowance to compensate or adjust the cooperation clearance between the sector swing gear and the tooth part, so that the cooperation between the sector swing gear and the tooth part of the connecting head is always in a delicate dynamic balance, thereby meeting the requirements of backlash elimination and clearance adjustment. This not only greatly reduces the strict standards for the assembly process but also effectively reduces the noise during the operation of the machine.

[0020] Preferably, oil seals extend radially outward at both ends in the length direction of the eccentric bushing. There is a gap between at least one oil seal and the corresponding side wall of the partition. Since the teeth on the sector swing gear are usually arranged obliquely, once there is a tooth position difference between the sector swing gear and the tooth part of the connecting head, an axial force will be generated. Therefore, due to the gap design between the oil seal and the partition, the axial force generated when the sector swing gear and the tooth part of the connecting head are meshed and matched will act on the sector swing gear in the reverse direction through the rotation of the countershaft and will ultimately be offset by the displacement of the eccentric bushing itself.

[0021] Specifically, a sealing cover for sealing the oil pressure chamber is further arranged on the transfer case.

[0022] Compared with the prior art, the advantages of the present invention are as follows: For the linkage drive structure of the pattern sewing machine, the power of the main shaft is efficiently transmitted to the auxiliary shaft through the first and second power dividing shafts of the power divider. Moreover, the crank whose first end is rotatably connected to the first power dividing shaft can transmit its rotational force to the auxiliary shaft with the support of the second power dividing shaft, enabling the auxiliary shaft to drive the oscillating shuttle to reciprocate relative to the main shaft synchronously, thereby realizing the thread picking function. In addition, the coaxial extension of each power dividing shaft with the main shaft and the auxiliary shaft makes each transmission part of the linkage drive structure clear and distinct, which is very conducive to maintenance. And when it is necessary to change the thread picking mode from the oscillating shuttle to the rotating shuttle, only the crank needs to be disassembled, and gears with corresponding gear ratios are installed on the first and second power dividing shafts. Without any complex disassembly and assembly, efficient replacement can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the overall structure of the pattern sewing machine in an embodiment of the present invention;

[0024] Figure 2 is Figure 1 a schematic diagram of the overall structure with some parts omitted;

[0025] Figure 3 is a schematic diagram of the overall linkage drive structure;

[0026] Figure 4 is Figure 3 a schematic diagram from another angle;

[0027] Figure 5 is a schematic diagram of the bottom of the power divider (the sealing cover is omitted). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The present invention will be further described in detail below in conjunction with the embodiments of the drawings.

[0029] Such as Figures 1 to 5As shown, this is a preferred embodiment of the present invention. In this embodiment, the linkage transmission structure for a pattern sewing machine includes a main shaft 31, a driver 32, a sub-shaft 33, and a power divider 34. The above-mentioned driver 32 is arranged adjacent to the first end of the main shaft 31, and its power output end is drivingly connected to the main shaft 31, thereby driving the main shaft 31 to rotate about its own axis. The sub-shaft 33 extends in the same direction as the main shaft 31, and a shuttle 38 is provided at its second end. The above-mentioned power divider 34 is arranged adjacent to the sub-shaft 33, and specifically includes a first power dividing shaft 341 and a second power dividing shaft 342 arranged side by side. Here, both the first power dividing shaft 341 and the second power dividing shaft 342 extend in the same direction as the main shaft 31 and the sub-shaft 33. Among them, the first power dividing shaft 341 is linked with the main shaft 31, and the second power dividing shaft 342 is arranged adjacent to the sub-shaft 33. The first end of the above-mentioned crank 343 is rotatably connected to the first power dividing shaft 341, and the second end is drivingly connected to the sub-shaft 33. Under the rotational action of the first power dividing shaft 341, the crank 343 intermittently acts on the sub-shaft 33, so that the sub-shaft 33 drives the shuttle to reciprocate relative to the main shaft 31 synchronously.

[0030] The power divider 34 can be of different design forms. In this embodiment, the above-mentioned power divider 34 is arranged below the sub-shaft 33. The crank 343 extends upward at the top of its second end with a sector-shaped swing gear 344. This sector-shaped swing gear 344 acts on the sub-shaft 33 and can drive the sub-shaft 33 to swing. The sub-shaft 33 is provided with a tooth portion 332 meshing with the sector-shaped swing gear 344 at the corresponding position. Specifically, a connector 331 is provided on the sub-shaft 33, the tooth portion 332 is arranged on the outer wall of the connector 331, and a retaining edge 333 for restricting the sector-shaped swing gear 344 from disengaging from the connector 331 is also provided on the connector 331. Such a design form of the crank 343 and the sector-shaped swing gear 344 makes the arc-shaped tooth portion of the sector-shaped swing gear 344 always extend upward and swing within a certain range, avoiding the situation of lateral extension or downward extension. Therefore, no matter how the power source is arranged, the center of gravity of the entire sector-shaped swing gear 344 always remains on the sub-shaft 33 and will not shift significantly, avoiding excessive local wear of the sector-shaped swing gear 344 caused by uneven force in the above other situations and ensuring the service life. The swing of the sub-shaft 33 can be achieved through different actions of the sector-shaped swing gear 344. One form is eccentricity. Therefore, in this embodiment, the above-mentioned crank 343 is eccentrically connected to the first power dividing shaft 341.

[0031] In addition, the above-mentioned components work in an oil pressure environment. The linkage transmission structure further includes a transfer case 36. The interior of the transfer case 36 is hollow to form an oil pressure chamber 360. A sealing cover for sealing the oil pressure chamber 360 is also provided on the transfer case 36. The above-mentioned first transfer shaft 341 and second transfer shaft 342 are both arranged in the oil pressure chamber 360, and the first end of the countershaft 33 extends into the oil pressure chamber 360. In order to ensure that the swing of the sector swing gear is not affected by the outside world, a partition 361 is provided in the transfer case 36 to divide the oil pressure chamber 360 into a first chamber 36a and a second chamber 36b. The first transmission wheel 351 is arranged in the first chamber 36a, and the crank 343 and the sector swing gear 344 are both arranged in the second chamber 36b.

[0032] In this embodiment, in order to ensure that the power of the main shaft can be transmitted to the first transfer shaft, a first transmission wheel 351 is provided on the above-mentioned first transfer shaft 341, a second transmission wheel 352 is provided on the main shaft 31, and the first transfer shaft 341 is linked by a transmission belt 353 that is sequentially wound around the first transmission wheel 351 and the second transmission wheel 352.

[0033] There may be a situation of being too tight or too loose between the sector swing gear 344 and the tooth part 332 of the connector 331 after assembly. Therefore, the linkage transmission structure for the pattern sewing machine further includes a backlash elimination structure 37 for adjusting the clearance between the sector swing gear 344 and the tooth part 332 of the connector 331. The backlash elimination structure 37 includes an eccentric bushing 371 and a backlash elimination hole 372 formed in the partition plate 361. The eccentric bushing 371 is sleeved around the outer periphery of the second sub-driving shaft 342 and is embedded in the backlash elimination hole 372. With such a design and installation form of the eccentric bushing 371 and the backlash elimination hole 372, since the eccentric bushing 371 itself has an inner ring and an outer ring, the outer ring is fixed to the backlash elimination hole 372, and the inner wall of the outer ring is an eccentric structure, so that the inner ring connected to the second sub-driving shaft 342 can trace and move on the inner wall of the outer ring. It is precisely because the clearance between the inner ring and the outer ring in the circumferential direction can be adjusted actively. When the cooperation between the sector swing gear 344 and the tooth part 332 of the connector 331 is too tight or too loose, the second sub-driving shaft 342 can drive the sector swing gear 344 to move synchronously along with the movement of the inner ring, and then provide a certain movement margin to compensate and adjust the cooperation clearance between the sector swing gear 344 and the tooth part 332 of the connector 331, so that the cooperation between the sector swing gear 344 and the tooth part 332 of the connector 331 is always in a delicate dynamic balance, thereby meeting the requirement of backlash elimination. This not only greatly reduces the strict standards for the assembly process but also effectively reduces the noise during the operation of the machine. During actual adjustment, first loosen the locking screw that fixes the sector swing gear 344 and the second sub-driving shaft 342 to make all components operate normally. After each gear rotates to a suitable position without jamming (the tooth part 332 of the sector swing gear 344 and the connector 331 automatically matches to a suitable position), lock the locking screw again.

[0034] In this embodiment, oil seals 373 extend radially outward along both ends of the length direction of the eccentric bushing 371, and there is a gap between at least one of the oil seals 373 and the corresponding side wall of the partition plate 361. Since the teeth on the sector swing gear 344 are usually arranged obliquely, once there is a tooth position difference between the sector swing gear 344 and the tooth part 332 of the connector 331, an axial force will be generated. Therefore, with the gap design between the oil seal and the partition plate, the axial force generated when the sector swing gear and the tooth part of the connector are meshed and matched will act on the sector swing gear in the reverse direction through the rotation of the auxiliary shaft and will ultimately be offset by the displacement of the eccentric bushing itself, thereby realizing the adjustment of the tooth position. Similar to the above adjustment process, this process also requires unlocking and relocking the corresponding locking screw, which will not be elaborated here.

[0035] In addition, terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", etc., are used in the description and claims of the present invention to describe various exemplary structural parts and elements of the present invention. However, these terms are used herein only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to the directions opposite to or consistent with the direction of gravity.

Claims

1. A linkage drive structure for a pattern sewing machine, comprising: a main shaft (31); a driver (32) arranged adjacent to the first end of the main shaft (31), and the power output end thereof is drivingly connected to the main shaft (31), thereby driving the main shaft (31) to rotate about its own axis; a sub-shaft (33) extending in the same direction as the main shaft (31), and a bobbin shuttle (38) is provided at the second end thereof; characterized in that it further comprises: a transfer case (34) arranged adjacent to the sub-shaft (33), including a first transfer shaft (341) and a second transfer shaft (342) arranged side by side, the first transfer shaft (341) and the second transfer shaft (342) both extend in the same direction as the main shaft (31) and the sub-shaft (33), wherein the first transfer shaft (341) is linked with the main shaft (31), and the second transfer shaft (342) is arranged adjacent to the sub-shaft (33); and a crank (343), the first end of which is rotatably connected to the first transfer shaft (341), and the second end of which is drivingly connected to the sub-shaft (33). Under the rotational action of the first transfer shaft (341), the crank (343) intermittently acts on the sub-shaft (33) so that the sub-shaft (33) drives the bobbin shuttle (38) to reciprocate relative to the main shaft (31) synchronously; the transfer case (34) is arranged below the sub-shaft (33), and a sector swing gear (344) extends upward at the top of the second end of the crank (343), and the sector swing gear (344) acts on the sub-shaft (33) and can drive the sub-shaft (33) to swing. A tooth portion (332) meshing with the sector swing gear (344) is provided at the corresponding position of the sub-shaft (33); a connector (331) is provided on the sub-shaft (33), the tooth portion (332) is provided on the outer wall of the connector (331), and a retaining edge (333) for restricting the sector swing gear (344) from disengaging from the connector (331) is further provided on the connector (331); A first transmission shaft (341) is provided with a first transmission wheel (351), a main shaft (31) is provided with a second transmission wheel (352), and the first transmission shaft (341) is linked through a transmission belt (353) sequentially wound around the first transmission wheel (351) and the second transmission wheel (352); the linkage transmission structure further includes a transfer case (36), the interior of the transfer case (36) is hollow to form an oil pressure chamber (360), the first transmission shaft (341) and the second transmission shaft (342) are both arranged in the oil pressure chamber (360), and a first end of the auxiliary shaft (33) extends into the oil pressure chamber (360); a partition plate (361) is arranged in the transfer case (36) to divide the oil pressure chamber (360) into a first chamber (36a) and a second chamber (36b), the first transmission wheel (351) is arranged in the first chamber (36a), and the crank (343) and the sector swing gear (344) are both arranged in the second chamber (36b); a clearance eliminating structure (37) for eliminating the clearance between the tooth part (332) of the sector swing gear (344) and the connector (331) is further included, the clearance eliminating structure (37) includes an eccentric bushing (371) and a clearance eliminating hole (372) formed in the partition plate (361), and the eccentric bushing (371) is sleeved around the second transmission shaft (342) and embedded in the clearance eliminating hole (372).

2. The linkage transmission structure according to claim 1, wherein: the crank (343) is eccentrically connected to the first transmission shaft (341).

3. The linkage transmission structure according to claim 1, wherein: oil seals (373) extend radially outward at both ends in the length direction of the eccentric bushing (371), and at least one of the oil seals (373) has a gap with the corresponding side wall of the partition plate (361).

4. The linkage transmission structure according to claim 3, wherein: a sealing cover for sealing the oil pressure chamber (360) is further arranged on the transfer case (36).

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