A sewing machine with adjustable stitch length and differential ratio, and a method for adjusting the sewing machine

Abstract

The application provides a sewing machine with adjustable stitch length and differential ratio, and a sewing machine adjusting method. The sewing machine comprises a main shaft, a main feed dog rack, main feed teeth, a differential feed dog rack, differential feed teeth, a main feed mechanism, a differential feed mechanism, an adjusting driving source, a main feed adjusting gear driven by the adjusting driving source, a differential feed adjusting gear in transmission connection with the main feed adjusting gear, and a differential feed adjusting unit. The main feed adjusting gear is coaxially fixed with a main feed transmission member. The differential feed adjusting unit is connected between the differential feed adjusting gear and a differential feed transmission member. The number of teeth of the differential feed adjusting gear is N, and the number of teeth of the main feed adjusting gear is n*N+1. The application can automatically adjust the stitch length and differential ratio of the sewing machine. By controlling the output of the adjusting driving source, the stitch length or differential ratio of the sewing machine can be accurately adjusted to a target value. Therefore, the adjustment precision of the stitch length and differential ratio is very high, and the adjustment is intelligent, saving time and effort.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sewing machines, in particular to a sewing machine with adjustable stitch length and differential ratio, and a method for adjusting the sewing machine using the same. BACKGROUND

[0002] Currently, when adjusting the stitch length of an overlock machine, the user needs to press down the needle opening shaft, block the pawl, and then rotate the main shaft to adjust the stitch length. This method of adjusting the stitch length has the following defects: 1. The precision of the stitch length adjustment is not high, there is no adjustment scale, and the user does not know the value of the adjusted stitch length, which is a blind adjustment; 2. The operation is laborious; 3. When adjusting the differential ratio, the user needs to rotate the screw to move the differential lever, which makes the adjustment of the differential ratio not precise and the operation very complicated and laborious. Therefore, the existing overlock machine is not intelligent in adjusting the stitch length and the differential ratio, and especially in adapting to different fabrics, the adjustment is mainly based on experience, resulting in low adjustment precision. SUMMARY

[0003] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present application is to provide a sewing machine with adjustable stitch length and differential ratio, which can accurately adjust the stitch length and the differential ratio.

[0004] To achieve the above-mentioned purpose, the present application provides a sewing machine with adjustable stitch length and differential ratio, which comprises a main shaft, a main feed dog rack, a main feed tooth fixed on the main feed dog rack, a differential feed dog rack, a differential feed tooth fixed on the differential feed dog rack, a main feed mechanism connected between the main shaft and the main feed tooth, and a differential feed mechanism connected between the main shaft and the differential feed tooth, wherein the main feed mechanism has a main feed transmission member that determines the transmission efficiency of the main feed mechanism, and the differential feed mechanism has a differential feed transmission member that determines the transmission efficiency of the differential feed mechanism; the sewing machine further comprises an adjustment driving source, a main feed adjustment gear driven to rotate by the adjustment driving source, a differential feed adjustment gear in transmission connection with the main feed adjustment gear, and a differential feed adjustment unit, wherein the main feed adjustment gear is coaxially fixed with the main feed transmission member, the differential feed adjustment unit is connected between the differential feed adjustment gear and the differential feed transmission member, the number of teeth of the differential feed adjustment gear is N, the number of teeth of the main feed adjustment gear is n*N+1, and n is a positive integer.

[0005] Further, the adjustment driving source is an electric motor, and the main feed adjustment gear is coaxially fixed with the motor shaft of the adjustment driving source.

[0006] Further, the main feed adjustment gear and the differential feed adjustment gear are in engagement and constitute a gear transmission mechanism.

[0007] Further, the main feed adjusting gear and the differential feed adjusting gear are connected by a synchronous belt, and the main feed adjusting gear, the differential feed adjusting gear and the synchronous belt constitute a synchronous belt wheel transmission mechanism.

[0008] Further, the main shaft is provided with a feed concentric shaft section, the main feed mechanism and the differential feed mechanism both include a feed eccentric wheel fixed on the feed concentric shaft section, a feed connecting rod and a feed connecting shaft, one end of the feed connecting rod is rotatably sleeved on the outer periphery of the feed eccentric wheel, the other end of the feed connecting rod is rotatably connected with the feed connecting shaft, the end of the feed connecting shaft is fixed with a sliding block part, and a pitch adjusting sliding groove is formed in the main feed transmission member and slidably connected with the sliding block part; the main feed mechanism further includes a main feed transmission unit connected between the feed connecting shaft and the main feed rack; the differential feed mechanism further includes a differential feed transmission unit connected between the feed connecting shaft and the differential feed rack.

[0009] Further, the main feed transmission unit includes a main feed connecting rod, a main feed lever with a fixed rotation fulcrum and a main feed sliding block, one end of the main feed connecting rod is rotatably connected with the feed connecting shaft, the other end of the main feed connecting rod is hingedly connected with the main feed lever, the main feed sliding block is rotatably installed on the main feed lever, a main feed sliding groove is formed in the main feed rack, and the main feed sliding block is movably assembled in the main feed sliding groove.

[0010] Further, the differential feed transmission unit includes a differential feed connecting rod, a differential feed lever, a differential adjusting sliding block and a differential feed sliding block, one end of the differential feed connecting rod is rotatably connected with the feed connecting shaft, the other end of the differential feed connecting rod is hingedly connected with the differential feed lever, the differential feed sliding block is rotatably installed on the differential feed lever, a differential feed sliding groove is formed in the differential feed rack, and the differential feed sliding block is movably assembled in the differential feed sliding groove; the differential feed lever is provided with a differential adjusting sliding groove slidably connected with the differential adjusting sliding block, and the differential feed transmission member is a differential adjusting shaft rotatably connected with the differential adjusting sliding block, which constitutes the rotation fulcrum of the differential feed lever.

[0011] Further, the differential feed adjusting unit includes a differential adjusting eccentric shaft and a differential adjusting connecting rod, the differential adjusting eccentric shaft includes a first shaft part coaxially fixed with the differential feed adjusting gear and a second shaft part eccentrically arranged with the first shaft part, and the two ends of the differential adjusting connecting rod are rotatably connected with the second shaft part and the differential adjusting shaft respectively.

[0012] Further, the main shaft has a lifting eccentric shaft section, and the sewing machine further comprises a lifting slider rotatably sleeved on the lifting eccentric shaft section.

[0013] The present application further provides a sewing machine adjusting method for adjusting the differential ratio of the sewing machine, which uses the sewing machine as described above, and comprises the following steps:

[0014] A1, configuring an electric control module, and connecting an adjusting driving source to the electric control module in communication;

[0015] A2, the sewing machine has a current stitch length and a current differential ratio;

[0016] A3, when the sewing machine needs to adjust the differential ratio, the electric control module calculates the number of teeth P that the differential feed adjusting gear needs to feed according to the current differential ratio and the target differential ratio of the sewing machine, and controls the adjusting driving source to drive the main feed adjusting gear to rotate P turns;

[0017] Then, the main feed adjusting gear drives the main feed transmission member to rotate P turns, the main feed transmission member remains in the original state, and the transmission efficiency of the main feed mechanism remains unchanged; at the same time, the main feed adjusting gear drives the differential feed adjusting gear to feed P teeth, and the differential feed adjusting gear acts on the differential feed transmission member through the differential feed adjusting unit, changes the state of the differential feed transmission member, and changes the transmission efficiency of the differential feed mechanism.

[0018] The present application further provides a sewing machine adjusting method for adjusting the stitch length of the sewing machine, which uses the sewing machine as described above, and comprises the following steps:

[0019] B1, configuring an electric control module, and connecting an adjusting driving source to the electric control module in communication;

[0020] B2, the sewing machine has a current stitch length and a current differential ratio;

[0021] B3, when the sewing machine needs to adjust the stitch length, or adjust the stitch length and the differential ratio, the electric control module calculates the number of teeth Q that the main feed adjusting gear needs to feed according to the current stitch length and the target stitch length of the sewing machine, and controls the adjusting driving source to drive the main feed adjusting gear to feed Q teeth;

[0022] The main feed adjustment gear drives the main feed transmission member to rotate the same angle, changes the state of the main feed transmission member, and changes the transmission efficiency of the main feed mechanism. At the same time, the main feed adjustment gear drives the differential feed adjustment gear to rotate an angle, and the differential feed adjustment gear acts on the differential feed transmission member through the differential feed adjustment unit, changes the state of the differential feed transmission member, and changes the transmission efficiency of the differential feed mechanism. At this time, the sewing machine has an intermediate differential ratio;

[0023] B4, the electric control module calculates the number of teeth R that the differential feed adjustment gear needs to feed according to the intermediate differential ratio and the target differential ratio of the sewing machine, and the electric control module controls the adjustment driving source to drive the main feed adjustment gear to rotate R turns;

[0024] The main feed adjustment gear drives the main feed transmission member to rotate R turns, and the main feed transmission member maintains the state in step B3, and the sewing machine maintains the target stitch length. At the same time, the main feed adjustment gear drives the differential feed adjustment gear to feed R teeth, and the differential feed adjustment gear acts on the differential feed transmission member through the differential feed adjustment unit, changes the state of the differential feed transmission member, and adjusts the sewing machine from the intermediate differential ratio to the target differential ratio.

[0025] As described above, the stitch length and differential ratio adjustable sewing machine and the sewing machine adjustment method have the following beneficial effects:

[0026] The present application can automatically adjust the stitch length and differential ratio of the sewing machine, and by controlling the output of the adjustment driving source, the stitch length or differential ratio of the sewing machine can be accurately adjusted to the target value, so the adjustment accuracy of the stitch length and differential ratio is very high, and it is intelligent adjustment, which saves time and effort, and greatly improves the user's experience. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a structure diagram of the stitch length and differential ratio adjustable sewing machine in the present application.

[0028] Figure 2 It is an exploded view of Figure 1

[0029] Figure 3 It is a connection diagram between the main feed adjustment gear and the main feed mechanism in the present application.

[0030] Figure 4 It is a connection diagram between the differential feed adjustment gear and the differential feed mechanism in the present application.

[0031] Figure 5 It is a connection diagram between the feed eccentric, the feed connecting rod, the feed connecting shaft, the main feed transmission member and the feed adjustment gear in the present application.​

[0032] Element No. Explanation

[0033] 10 main shaft

[0034] 101 feed dog concentric shaft section

[0035] 102 lifting dog eccentric shaft section

[0036] 21 main feed dog rack

[0037] 211 main feed dog chute

[0038] 22 main feed dog tooth

[0039] 23 differential feed dog rack

[0040] 231 differential feed dog chute

[0041] 24 differential feed dog tooth

[0042] 25 lifting dog chute

[0043] 30 adjustment drive source

[0044] 41 main feed adjustment gear

[0045] 42 differential feed adjustment gear

[0046] 50 differential feed adjustment unit

[0047] 51 differential adjustment eccentric shaft

[0048] 511 first shaft portion

[0049] 512 second shaft portion

[0050] 513 connecting disc portion

[0051] 52 differential adjustment link

[0052] 61 feed dog eccentric

[0053] 62 feed dog link

[0054] 63 feed dog connecting shaft

[0055] 631 slider portion

[0056] 71 main feed dog transmission member

[0057] 711 pitch adjustment chute

[0058] 712 connecting shaft portion

[0059] 72 main feed dog link

[0060] 73 main feed dog lever

[0061] 74 main feed dog

[0062] 81 differential feed drive

[0063] 82 differential feed link

[0064] 83 differential feed lever

[0065] 831 differential adjustment slot

[0066] 84 differential adjustment dog

[0067] 85 differential feed dog

[0068] 90 lift dog DETAILED DESCRIPTION

[0069] The present application will be described in greater detail by specific embodiments, and other advantages and effects of the present application can be easily understood by those skilled in the art from the contents disclosed in the present specification.

[0070] It should be understood that the structures, proportions, sizes, etc. shown in the drawings of the present specification are merely used to understand and read the contents disclosed in the present specification by those skilled in the art, and are not used to limit the conditions that the present application can be implemented, and therefore do not have technical substantial meanings. Any modification of the structures, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present application can produce and the purposes that the present application can achieve, should still fall within the scope of the technical contents disclosed in the present application. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle", etc. cited in the present specification are merely used for clear description, and are not used to limit the scope of the present application, and the change or adjustment of the relative relationship, without substantially changing the technical contents, should also be considered as the scope of the present application.

[0071] The present application provides a sewing machine with adjustable stitch length and differential ratio, and the model of the sewing machine is an overlock machine. As shown in Figure 1 and Figure 2 , the sewing machine comprises a main shaft 10, a main feed dog rack 21, a main feed dog 22 fixed on the main feed dog rack 21, a differential feed dog rack 23, a differential feed dog 24 fixed on the differential feed dog rack 23, a main feed mechanism connected between the main shaft 10 and the main feed dog 22, and a differential feed mechanism connected between the main shaft 10 and the differential feed dog 24, the main feed dog rack 21 and the differential feed dog rack 23 are arranged side by side along the axial direction of the main shaft 10, the main feed dog 22 and the differential feed dog 24 are arranged side by side along the feed direction of the overlock machine, the main feed mechanism has a main feed drive 71 for determining the transmission efficiency of the main feed mechanism, and the differential feed mechanism has a differential feed drive 81 for determining the transmission efficiency of the differential feed mechanism.

[0072] In particular, the sewing machine further comprises an adjusting driving source 30, a main feed adjusting gear 41, a differential feed adjusting gear 42, and a differential feed adjusting unit 50, an output end of the adjusting driving source 30 is in transmission connection with the main feed adjusting gear 41 to drive the main feed adjusting gear 41 to rotate, the main feed adjusting gear 41 is coaxially fixed with a main feed transmission member 71 in a main feed mechanism and synchronously rotates with the main feed transmission member 71, the main feed adjusting gear 41 is in transmission connection with the differential feed adjusting gear 42, and the differential feed adjusting gear 42 is in transmission connection with a differential feed transmission member 81 in a differential feed mechanism through the differential feed adjusting unit 50; and the differential feed adjusting gear 42 has N teeth, the main feed adjusting gear 41 has n*N+1 teeth, and n is a positive integer. Therefore, the number of teeth of the main feed adjusting gear 41 can be N+1, or 2N+1, or 3N+1, or other. Thus, when the main feed adjusting gear 41 rotates through a whole circle, the differential feed adjusting gear 42 rotates through several whole circles plus the number of teeth corresponding to the number of rotations of the main feed adjusting gear 41. In this way, after the main feed adjusting gear 41 rotates through M whole circles, it remains in the original state without feeding the number of teeth, and the differential feed adjusting gear 42 feeds M teeth relative to the original state.

[0073] When the sewing machine operates, the adjusting driving source 30 does not act, and then the main feed transmission member 71 and the differential feed transmission member 81 remain in the current state, that is, remain in the current position angle. The main shaft 10 rotates to drive the main feed tooth bar 21 and the main feed tooth 22 to reciprocate forward and backward through the main feed mechanism to perform the feeding action. The transmission efficiency of the main feed mechanism is constant, and the movement amplitude of the main feed tooth 22 in the forward and backward direction is also constant. The movement amplitude of the main feed tooth 22 in the forward and backward direction is the stitch length of the sewing machine, and then the stitch length of the sewing machine remains constant. Meanwhile, the main shaft 10 also drives the differential feed tooth bar 23 and the differential feed tooth 24 to reciprocate forward and backward through the differential feed mechanism to perform the feeding action. The transmission efficiency of the differential feed mechanism is constant, and the movement amplitude of the differential feed tooth 24 in the forward and backward direction is also constant. The ratio of the movement amplitude of the main feed tooth 22 in the forward and backward direction to the movement amplitude of the differential feed tooth 24 in the forward and backward direction is the differential ratio of the sewing machine, and then the differential ratio of the sewing machine remains constant.

[0074] Further, the present application also provides a sewing machine adjusting method using the above sewing machine, which can be used to adjust the differential ratio and the stitch length of the sewing machine.

[0075] When the sewing machine adjusting method is used to adjust the differential ratio of the sewing machine alone, the sewing machine adjusting method comprises the following steps:

[0076] A1, configuring an electric control module, and making the adjusting driving source 30 in communication connection with the electric control module;

[0077] A2, the sewing machine has a current stitch length and a current differential ratio;

[0078] A3, when the sewing machine needs to adjust the differential ratio, the electric control module calculates the number of teeth P that the differential feed adjustment gear 42 needs to feed according to the current differential ratio and the target differential ratio of the sewing machine, the number of teeth P corresponds to the angle of feed of the differential feed adjustment gear 42, the electric control module controls the adjustment driving source 30 to act, so that the adjustment driving source 30 drives the main feed adjustment gear 41 to rotate P turns. After the main feed adjustment gear 41 rotates P turns, the main feed adjustment gear 41 drives the main feed transmission member 71 to rotate P turns together. Since the main feed adjustment gear 41 and the main feed transmission member 71 both rotate a full turn, the main feed adjustment gear 41 does not feed teeth, and the main feed adjustment gear 41 and the main feed transmission member 71 both remain in the original state, and the respective position angles do not change. In this way, after the electric control module drives the main feed adjustment gear 41 to rotate P full turns, the transmission efficiency of the main feed mechanism remains unchanged, so that the stitch length of the sewing machine remains unchanged, still being the current stitch length. At the same time, the main feed adjustment gear 41 also drives the differential feed adjustment gear 42 to rotate several full turns and then feeds P teeth, that is, the differential feed adjustment gear 42 feeds P teeth relative to its original state. Then, the differential feed adjustment gear 42 acts on the differential feed transmission member 81 through the differential feed adjustment unit 50. The differential feed adjustment gear 42 rotates through the feed angle corresponding to P teeth, so that the state of the differential feed transmission member 81 changes, that is, the position angle of the differential feed transmission member 81 changes, thereby changing the transmission efficiency of the differential feed mechanism. As a result, the movement amplitude of the differential feed teeth 24 in the front and back directions changes, and finally the adjustment of the differential ratio of the sewing machine is realized.

[0079] When the sewing machine adjustment method is used to simultaneously adjust the stitch length and the differential ratio of the sewing machine, the sewing machine adjustment method comprises the following steps:

[0080] B1, the electric control module is configured to communicate with the adjustment driving source 30;

[0081] B2, the sewing machine has a current stitch length and a current differential ratio;

[0082] B3、When the sewing machine needs to adjust the stitch length, the electric control module calculates the number of teeth Q that the main feed adjustment gear 41 needs to feed according to the current stitch length and the target stitch length of the sewing machine, the number of teeth Q corresponds to the angle that the main feed adjustment gear needs to feed, the electric control module controls the adjustment driving source 30 to act, so that the adjustment driving source 30 drives the main feed adjustment gear 41 to rotate through the corresponding angle and then feed Q teeth. After the main feed adjustment gear 41 rotates through the angle corresponding to Q teeth, the main feed adjustment gear 41 drives the main feed transmission member 71 to rotate through the same angle, changes the state of the main feed transmission member 71, that is, changes the position angle of the main feed transmission member 71, thereby changing the transmission efficiency of the main feed mechanism, so that the movement amplitude of the main feed tooth 22 in the front and back directions changes, and finally the adjustment of the stitch length of the sewing machine is realized. At the same time, the main feed adjustment gear 41 also drives the differential feed adjustment gear 42 to rotate an angle, and the differential feed adjustment gear 42 acts on the differential feed transmission member 81 through the differential feed adjustment unit 50 to change the state of the differential feed transmission member 81 and change the transmission efficiency of the differential feed mechanism. At this time, the sewing machine has an intermediate differential ratio, that is, the differential ratio of the sewing machine changes from the current differential ratio to the intermediate differential ratio.

[0083] B4、According to the operation in the above-mentioned step A3, the differential ratio of the sewing machine is adjusted from the intermediate differential ratio to the target differential ratio. Specifically, the electric control module calculates the number of teeth R that the differential feed adjustment gear 42 needs to feed according to the intermediate differential ratio and the target differential ratio of the sewing machine, the number of teeth R corresponds to the angle that the differential feed adjustment gear 42 needs to feed, and the electric control module controls the adjustment driving source 30 to act, so that the adjustment driving source 30 drives the main feed adjustment gear 41 to rotate R turns. After the main feed adjustment gear 41 rotates R turns, the main feed adjustment gear 41 drives the main feed transmission member 71 to rotate R complete turns, then the main feed adjustment gear 41 and the main feed transmission member 71 both remain in the original state, the transmission efficiency of the main feed mechanism remains unchanged, so that the stitch length of the sewing machine remains the target stitch length after the above-mentioned step B3 is executed. At the same time, the main feed adjustment gear 41 also drives the differential feed adjustment gear 42 to rotate several complete turns and then feed R teeth, and the differential feed adjustment gear 42 changes the position angle of the differential feed transmission member 81 through the differential feed adjustment unit 50, thereby changing the transmission efficiency of the differential feed mechanism and adjusting the differential ratio of the sewing machine from the intermediate differential ratio to the target differential ratio.

[0084] When the sewing machine adjustment method is used to adjust the stitch length of the sewing machine alone, the target differential ratio in the above-mentioned step B4 is the original current differential ratio, that is, the above-mentioned step B4 adjusts the differential ratio of the sewing machine from the intermediate differential ratio to the current differential ratio.

[0085] Therefore, the sewing machine can automatically adjust the stitch length and the differential ratio, can independently adjust the stitch length of the sewing machine, can independently adjust the differential ratio of the sewing machine, and can simultaneously adjust the stitch length and the differential ratio of the sewing machine; by controlling the output of the adjustment driving source 30, the stitch length or the differential ratio of the sewing machine can be accurately adjusted to a target value, so that the adjustment accuracy of the stitch length and the differential ratio is very high, and the adjustment is intelligent, without manual operation process, saving time and effort, and greatly improving the user experience.

[0086] Preferably, the sewing machine is further provided with a display screen, and the display screen is in communication connection with the electric control module, so that the current stitch length and the current differential ratio of the sewing machine can be directly displayed on the display screen, realizing digital and visual adjustment.

[0087] Further, the adjustment driving source 30 is a motor, preferably a stepper motor, and the main feed adjustment gear 41 is coaxially fixed with the motor shaft of the adjustment driving source 30. In this embodiment, as shown in Figure 1 and Figure 2 , the main feed driving member 71 is provided with a connecting shaft part 712 parallel to the main shaft 10, and the main feed adjustment gear 41 is fixed on the connecting shaft part 712 by screw locking; the connecting shaft part 712 and the motor shaft of the adjustment driving source 30 are fixedly connected through a shaft coupling; in this way, the motor shaft of the adjustment driving source 30, the main feed driving member 71 and the main feed adjustment gear 41 are coaxially fixed.

[0088] Further, the transmission connection mode between the main feed adjustment gear 41 and the differential feed adjustment gear 42 can be direct engagement and fixation, or connection through a synchronous belt. In this embodiment, the main feed adjustment gear 41 and the differential feed adjustment gear 42 are engaged, so that the main feed adjustment gear 41 and the differential feed adjustment gear 42 constitute a gear transmission mechanism; the main feed adjustment gear 41 and the differential feed adjustment gear 42 can be helical gear engagement or spur gear engagement. Of course, in other embodiments, the main feed adjustment gear 41 and the differential feed adjustment gear 42 are connected through a synchronous belt, so that the main feed adjustment gear 41, the differential feed adjustment gear 42 and the synchronous belt constitute a synchronous belt wheel transmission mechanism.

[0089] Further, as shown in Figure 2 , the main shaft 10 has a feed concentric shaft section 101, and the feed concentric shaft section 101 is concentric with the main shaft 10; as shown in Figures 3 to 5As shown, the main feed mechanism and the differential feed mechanism both include a feed eccentric wheel 61, a feed connecting rod 62, and a feed connecting shaft 63 parallel to the main shaft 10, the upper end of the feed connecting rod 62 is rotatably sleeved on the outer periphery of the feed eccentric wheel 61 through a bearing, and the lower end of the feed connecting rod 62 is in rotational cooperation with the feed connecting shaft 63, that is, the feed connecting shaft 63 is rotatably arranged at the lower end of the feed connecting rod 62; the end of the feed connecting shaft 63 is integrally provided with a sliding block part 631, a stitch length adjusting sliding groove 711 is formed in the main feed transmission part 71 and in sliding cooperation with the sliding block part 631, and the stitch length adjusting sliding groove 711 is a radially extending groove; the main feed mechanism further includes a main feed transmission unit connected between the feed connecting shaft 63 and the main feed rack 21; the differential feed mechanism further includes a differential feed transmission unit connected between the feed connecting shaft 63 and the differential feed rack 23. When the main feed transmission part 71 rotates a full circle with the main feed adjusting gear 41, the position angle of the stitch length adjusting sliding groove 711 in the main feed transmission part 71 does not change, so that the motion track of the subsequent feed connecting shaft 63 remains unchanged, so that the transmission efficiency of the main feed mechanism remains unchanged. When the main feed transmission part 71 rotates a non-full circle with the main feed adjusting gear 41, the position angle of the stitch length adjusting sliding groove 711 in the main feed transmission part 71 changes, so that the motion track of the subsequent feed connecting shaft 63 changes, so that the transmission efficiency of the main feed mechanism changes, thereby realizing the adjustment of the stitch length of the sewing machine.

[0090] In addition, the adjusting driving source 30 is provided with an encoder for detecting the angle of the motor shaft. When adjusting the stitch length and / or the differential ratio, the main shaft 10 needs to be rotated first, the main shaft 10 acts on the feed connecting shaft 63 through the feed eccentric wheel 61 and the feed connecting rod 62, until the feed connecting shaft 63 is concentric with the main feed adjusting gear 41, and then the adjusting driving source 30 is actuated to adjust the stitch length and / or the differential ratio; in this process, the feed connecting shaft 63 acts on the motor shaft of the adjusting driving source 30 through the main feed transmission part 71 and the main feed adjusting gear 41, and the output of the encoder can be used to determine whether the feed connecting shaft 63 is concentric with the main feed adjusting gear 41.

[0091] Further, as shown in FIG. 6, Figure 1 , Figure 2 and Figure 3As shown, the main feed drive unit includes a main feed connecting rod 72, a main feed lever 73 with a fixed rotation fulcrum, and a main feed slider 74. One end of the main feed connecting rod 72 is rotationally connected with the feed connecting shaft 63, the other end of the main feed connecting rod 72 is hingedly connected with the lower end of the main feed lever 73, and the main feed slider 74 is rotationally installed at the upper end of the main feed lever 73. A main feed sliding slot 211 is formed in the main feed rack 21, and the main feed slider 74 is movably assembled in the main feed sliding slot 211. Preferably, the front side and the rear side of the main feed slider 74 are in surface contact with the slot walls of the main feed sliding slot 211.

[0092] Further, as shown in Figure 1 , Figure 2 and Figure 4 , the differential feed drive unit includes a differential feed connecting rod 82, a differential feed lever 83, a differential adjustment slider 84, and a differential feed slider 85. One end of the differential feed connecting rod 82 is rotationally connected with the feed connecting shaft 63, the other end of the differential feed connecting rod 82 is hingedly connected with the lower end of the differential feed lever 83, the differential feed slider 85 is rotationally installed at the upper end of the differential feed lever 83, a differential feed sliding slot 231 is formed in the differential feed rack 23, and the differential feed slider 85 is movably assembled in the differential feed sliding slot 231. A differential adjustment sliding slot 831 is formed in the differential feed lever 83 and slidably connected with the differential adjustment slider 84, and the differential feed drive 81 is a differential adjustment shaft rotationally connected with the differential adjustment slider 84, which constitutes the rotation fulcrum of the differential feed lever 83. By changing the up-and-down position of the differential adjustment shaft in the differential adjustment sliding slot 831, or the up-and-down position of the rotation fulcrum of the differential feed lever 83, the transmission efficiency of the differential feed mechanism is changed, thereby adjusting the differential ratio of the sewing machine. In addition, in this application, the lower end of the feed connecting rod 62, one end of the main feed connecting rod 72, and one end of the differential feed connecting rod 82 are coaxially hingedly connected through the feed connecting shaft 63. Preferably, the front side and the rear side of the differential feed slider 85 are in surface contact with the slot walls of the differential feed sliding slot 231.

[0093] Further, as shown in Figure 1 , Figure 2 and Figure 4As shown, the differential feed adjustment unit 50 comprises a differential adjustment eccentric shaft 51 and a differential adjustment connecting rod 52, the differential adjustment eccentric shaft 51 comprises a first shaft part 511 coaxially fixed with the differential feed adjustment gear 42, a second shaft part 512 eccentrically arranged with the first shaft part 511, and a connecting disc part 513 connected between the first shaft part 511 and the second shaft part 512, and two ends of the differential adjustment connecting rod 52 are respectively rotationally matched with the second shaft part 512 and the differential adjustment shaft. When the differential feed adjustment gear 42 rotates, the first shaft part 511 of the differential adjustment eccentric shaft 51 is driven to rotate synchronously, and then the differential adjustment shaft is driven to move by the second shaft part 512 of the differential adjustment eccentric shaft 51 and the differential adjustment connecting rod 52, the up-down position of the differential adjustment shaft is changed, the up-down position of the rotation fulcrum of the differential feed lever 83 is changed, and the differential ratio of the sewing machine is adjusted.

[0094] Further, as shown in Figure 1 and Figure 2 shown, the main shaft 10 has a lifting tooth eccentric shaft section 102, the lifting tooth eccentric shaft section 102 is eccentric with the main shaft 10; the sewing machine further comprises a lifting tooth sliding block 90 rotationally sleeved on the lifting tooth eccentric shaft section 102, the main feed tooth holder 21 and the differential feed tooth holder 23 are both provided with a lifting tooth sliding groove 25, and the lifting tooth sliding block 90 is movably assembled in the lifting tooth sliding groove 25 of the main feed tooth holder 21 and the differential feed tooth holder 23. Preferably, the upper side and the lower side of the lifting tooth sliding block 90 are both surface-contacting matched with the groove walls of the lifting tooth sliding groove 25.

[0095] The following provides a specific embodiment of the sewing machine.

[0096] In the sewing machine, the stitch length adjustment range is 0-4.5mm, the differential ratio adjustment range is 0.7-2.0, the number of teeth of the differential feed adjustment gear 42 is 29, and the number of teeth of the main feed adjustment gear 41 is 4*29+1=117; thus, when the main feed adjustment gear 41 rotates one circle, the differential feed adjustment gear 42 rotates four circles and feeds one tooth number again; when the main feed adjustment gear 41 rotates two circles, the differential feed adjustment gear 42 rotates eight circles and feeds two tooth numbers again; and so on. The current stitch length of the sewing machine is 2.5mm, and the angle of the main feed adjustment gear 41 is 30°; the current differential ratio of the sewing machine is 1:1, and the height of the rotation fulcrum of the differential feed lever 83 is 25.5mm.

[0097] I. Only adjust the differential ratio of the sewing machine, adjust the differential ratio of the sewing machine from 1:1 to 1:2. The differential ratio 1:2 corresponds to the height of the rotation fulcrum of the differential feed lever 83 of 17mm, and the feed angle of the differential feed adjusting gear 42 of 75.51°, and the feed angle corresponding to one tooth of the differential feed adjusting gear 42 of 12.4°, so that the differential feed adjusting gear 42 needs to feed 6 teeth. Therefore, the electric control module controls the action of the adjusting drive source 30, the adjusting drive source 30 drives the main feed adjusting gear 41 to rotate 6 whole turns, and the angle of the main feed adjusting gear 41 is still 30°, the position angle of the stitch length adjusting slot 711 of the main feed transmission member 71 remains unchanged, and the stitch length of the sewing machine is still 2.5mm; the main feed adjusting gear 41 drives the differential feed adjusting gear 42 to rotate 24 whole turns and then feed 6 teeth, and the differential feed adjusting gear 42 moves the differential feed transmission member 81 downward through the differential adjusting eccentric shaft 51 and the differential adjusting connecting rod 52, so as to adjust the differential ratio of the sewing machine to 1:2.

[0098] II. Only adjust the stitch length of the sewing machine, adjust the stitch length of the sewing machine from 2.5mm to 3.5mm. The stitch length of 3.5mm corresponds to the angle of the main feed adjusting gear 41 of 12°. First, the electric control module controls the action of the adjusting drive source 30, and the adjusting drive source 30 drives the main feed adjusting gear 41 to rotate from 30° to 12°, thereby adjusting the stitch length of the sewing machine to 3.5mm. However, in this process, the main feed adjusting gear 41 drives the differential feed adjusting gear 42 to rotate through an angle, which changes the height position of the rotation fulcrum of the differential feed lever 83, resulting in that the differential ratio of the sewing machine is adjusted from 1:1 to the intermediate transmission ratio at this time. Thus, by the above process of only adjusting the differential ratio of the sewing machine, the differential ratio of the sewing machine is adjusted back from the intermediate transmission ratio to the original differential ratio 1:1, thereby realizing the adjustment of only the stitch length of the sewing machine.

[0099] III. Adjust the differential ratio and the stitch length of the sewing machine at the same time, combine the above two processes, and adjust the differential ratio and the stitch length of the sewing machine to the target values respectively, first adjust the stitch length, and then adjust the differential ratio.

[0100] In summary, the present application effectively overcomes the shortcomings in the prior art and has high industrial utilization value.

[0101] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A sewing machine adjustment method using a sewing machine with adjustable stitch length and differential ratio, the sewing machine comprising a main shaft (10), a main feed dog rack (21), a main feed dog (22) fixed on the main feed dog rack (21), a differential feed dog rack (23), a differential feed dog (24) fixed on the differential feed dog rack (23), a main feed mechanism connected between the main shaft (10) and the main feed dog (22), and a differential feed mechanism connected between the main shaft (10) and the differential feed dog (24), the main feed mechanism having a main feed driving part (71) determining the driving efficiency of the main feed mechanism, the differential feed mechanism having a differential feed driving part (81) determining the driving efficiency of the differential feed mechanism, characterized in that: The adjusting device further comprises an adjusting driving source (30), a main feed adjusting gear (41) driven by the adjusting driving source (30), a differential feed adjusting gear (42) in transmission connection with the main feed adjusting gear (41), and a differential feed adjusting unit (50) connected between the differential feed adjusting gear (42) and a differential feed transmission member (81), wherein the main feed adjusting gear (41) is coaxially fixed with the main feed transmission member (71), the differential feed adjusting unit (50) is connected between the differential feed adjusting gear (42) and the differential feed transmission member (81), the differential feed adjusting gear (42) has N teeth, and the main feed adjusting gear (41) has n*N+1 teeth, wherein n is a positive integer. The sewing machine adjusting method comprises the following steps: A1, configuring an electric control module, so that the adjusting driving source (30) is in communication connection with the electric control module; A2, the sewing machine has a current stitch length and a current differential ratio; A3, when the sewing machine needs to adjust the differential ratio, the electric control module calculates the number of teeth P that the differential feed adjusting gear (42) needs to feed according to the current differential ratio and a target differential ratio of the sewing machine, and controls the adjusting driving source (30) to act, so that the adjusting driving source (30) drives the main feed adjusting gear (41) to rotate P turns; Then the main feed adjusting gear (41) drives the main feed transmission member (71) to rotate P turns, the main feed transmission member (71) remains in the original state, and the transmission efficiency of the main feed mechanism remains unchanged; at the same time, the main feed adjusting gear (41) drives the differential feed adjusting gear (42) to feed P teeth, and the differential feed adjusting gear (42) acts on the differential feed transmission member (81) through the differential feed adjusting unit (50), changes the state of the differential feed transmission member (81), and changes the transmission efficiency of the differential feed mechanism.

2. The sewing machine adjustment method of claim 1, wherein: The adjusting driving source (30) is a motor, and the main feed adjusting gear (41) is coaxially fixed with a motor shaft of the adjusting driving source (30).

3. The sewing machine adjustment method of claim 1, wherein: The main feed adjusting gear (41) and the differential feed adjusting gear (42) are in meshing engagement and constitute a gear transmission mechanism.

4. The sewing machine adjustment method of claim 1, wherein: The main feed adjusting gear (41) and the differential feed adjusting gear (42) are connected through a synchronous belt, and the main feed adjusting gear (41), the differential feed adjusting gear (42) and the synchronous belt constitute a synchronous belt wheel transmission mechanism.

5. The sewing machine adjustment method of claim 1, wherein: The main shaft (10) has a cloth feeding concentric shaft section (101), the main cloth feeding mechanism and the differential cloth feeding mechanism both include a cloth feeding eccentric wheel (61), a cloth feeding connecting rod (62) and a cloth feeding connecting shaft (63) fixed on the cloth feeding concentric shaft section (101), one end of the cloth feeding connecting rod (62) is rotatably sleeved on the outer periphery of the cloth feeding eccentric wheel (61), the other end of the cloth feeding connecting rod (62) is rotatably connected with the cloth feeding connecting shaft (63), the end of the cloth feeding connecting shaft (63) is fixed with a sliding block part (631), the main cloth feeding transmission part (71) is provided with a pitch adjusting sliding groove (711) slidably connected with the sliding block part (631); the main cloth feeding mechanism further includes a main cloth feeding transmission unit connected between the cloth feeding connecting shaft (63) and the main cloth feeding rack (21); the differential cloth feeding mechanism further includes a differential cloth feeding transmission unit connected between the cloth feeding connecting shaft (63) and the differential cloth feeding rack (23).

6. The sewing machine adjustment method of claim 5, wherein: The main cloth feeding transmission unit includes a main cloth feeding connecting rod (72), a main cloth feeding lever (73) having a fixed rotation supporting point and a main cloth feeding sliding block (74), one end of the main cloth feeding connecting rod (72) is rotatably connected with the cloth feeding connecting shaft (63), the other end of the main cloth feeding connecting rod (72) is hingedly connected with the main cloth feeding lever (73), the main cloth feeding sliding block (74) is rotatably installed on the main cloth feeding lever (73), the main cloth feeding rack (21) is provided with a main cloth feeding sliding groove (211), the main cloth feeding sliding block (74) is movably assembled in the main cloth feeding sliding groove (211).

7. The sewing machine adjustment method of claim 5, wherein: The differential cloth feeding transmission unit includes a differential cloth feeding connecting rod (82), a differential cloth feeding lever (83), a differential adjusting sliding block (84) and a differential cloth feeding sliding block (85), one end of the differential cloth feeding connecting rod (82) is rotatably connected with the cloth feeding connecting shaft (63), the other end of the differential cloth feeding connecting rod (82) is hingedly connected with the differential cloth feeding lever (83), the differential cloth feeding sliding block (85) is rotatably installed on the differential cloth feeding lever (83), the differential cloth feeding rack (23) is provided with a differential cloth feeding sliding groove (231), the differential cloth feeding sliding block (85) is movably assembled in the differential cloth feeding sliding groove (231); the differential cloth feeding lever (83) is provided with a differential adjusting sliding groove (831) slidably connected with the differential adjusting sliding block (84), the differential cloth feeding transmission part (81) is a differential adjusting shaft rotatably connected with the differential adjusting sliding block (84), the differential adjusting shaft forms the rotation supporting point of the differential cloth feeding lever (83).

8. The sewing machine adjustment method of claim 7, wherein: The differential cloth feeding adjusting unit (50) includes a differential adjusting eccentric shaft (51) and a differential adjusting connecting rod (52), the differential adjusting eccentric shaft (51) includes a first shaft part (511) coaxially fixed with the differential cloth feeding adjusting gear (42) and a second shaft part (512) eccentrically arranged with the first shaft part (511), the two ends of the differential adjusting connecting rod (52) are rotatably connected with the second shaft part (512) and the differential adjusting shaft respectively.

9. The sewing machine adjustment method of claim 1, wherein: The main shaft (10) has a lifting eccentric shaft section (102), the sewing machine further comprises a lifting slider (90) rotatably sleeved on the lifting eccentric shaft section (102), the main feed dog rack (21) and the differential feed dog rack (23) are both provided with lifting sliding grooves (25), and the lifting slider (90) is movably assembled in the lifting sliding grooves (25) of the main feed dog rack (21) and the differential feed dog rack (23).

10. A sewing machine adjustment method using a sewing machine with adjustable stitch length and differential ratio, the sewing machine comprising a main shaft (10), a main feed dog rack (21), a main feed dog (22) fixed on the main feed dog rack (21), a differential feed dog rack (23), a differential feed dog (24) fixed on the differential feed dog rack (23), a main feed mechanism connected between the main shaft (10) and the main feed dog (22), and a differential feed mechanism connected between the main shaft (10) and the differential feed dog (24), the main feed mechanism having a main feed driving member (71) determining driving efficiency of the main feed mechanism, the differential feed mechanism having a differential feed driving member (81) determining driving efficiency of the differential feed mechanism, characterized in that: Further comprising an adjusting driving source (30), a main feed adjusting gear (41) driven to rotate by the adjusting driving source (30), a differential feed adjusting gear (42) in transmission connection with the main feed adjusting gear (41), and a differential feed adjusting unit (50), the main feed adjusting gear (41) is coaxially fixed with the main feed transmission member (71), the differential feed adjusting unit (50) is connected between the differential feed adjusting gear (42) and the differential feed transmission member (81), the differential feed adjusting gear (42) has N teeth, the main feed adjusting gear (41) has n*N+1 teeth, and n is a positive integer; The sewing machine adjusting method comprises the following steps: B1, configuring an electric control module, so that the adjusting driving source (30) is in communication connection with the electric control module; B2, the sewing machine has a current stitch length and a current differential ratio; B3, when the sewing machine needs to adjust the stitch length or the stitch length and the differential ratio, the electric control module calculates the number of teeth Q that the main feed adjusting gear (41) needs to feed according to the current stitch length and the target stitch length of the sewing machine, and controls the adjusting driving source (30) to drive the main feed adjusting gear (41) to feed Q teeth; Then the main feed adjusting gear (41) drives the main feed transmission member (71) to rotate by the same angle, changes the state of the main feed transmission member (71), changes the transmission efficiency of the main feed mechanism, at the same time, the main feed adjusting gear (41) drives the differential feed adjusting gear (42) to rotate by an angle, the differential feed adjusting gear (42) acts on the differential feed transmission member (81) through the differential feed adjusting unit (50), changes the state of the differential feed transmission member (81), changes the transmission efficiency of the differential feed mechanism, and at this time the sewing machine has an intermediate differential ratio; B4, the electric control module calculates the number of teeth R that the differential feed adjusting gear (42) needs to feed according to the intermediate differential ratio and the target differential ratio of the sewing machine, and controls the adjusting driving source (30) to drive the main feed adjusting gear (41) to rotate R turns. The main feed adjustment gear (41) drives the main feed transmission member (71) to rotate R turns, the main feed transmission member (71) keeps the state in step B3, and the sewing machine keeps the target stitch length; meanwhile, the main feed adjustment gear (41) drives the differential feed adjustment gear (42) to feed R teeth, the differential feed adjustment gear (42) acts on the differential feed transmission member (81) through the differential feed adjustment unit (50), changes the state of the differential feed transmission member (81), and adjusts the sewing machine from the intermediate differential ratio to the target differential ratio.

11. The sewing machine adjustment method of claim 10, wherein: The adjustment driving source (30) is an electric motor, and the main feed adjustment gear (41) is coaxially fixed with the motor shaft of the adjustment driving source (30).

12. The sewing machine adjustment method of claim 10, wherein: The main feed adjustment gear (41) and the differential feed adjustment gear (42) are engaged and constitute a gear transmission mechanism.

13. The sewing machine adjustment method of claim 10, wherein: The main feed adjustment gear (41) and the differential feed adjustment gear (42) are connected through a synchronous belt, and the main feed adjustment gear (41), the differential feed adjustment gear (42), and the synchronous belt constitute a synchronous belt wheel transmission mechanism.

14. The sewing machine adjustment method of claim 10, wherein: The main shaft (10) has a feed concentric shaft section (101), the main feed mechanism and the differential feed mechanism both include a feed eccentric wheel (61), a feed connecting rod (62), and a feed connecting shaft (63) fixed on the feed concentric shaft section (101), one end of the feed connecting rod (62) is rotatably sleeved on the outer periphery of the feed eccentric wheel (61), the other end of the feed connecting rod (62) is rotatably connected with the feed connecting shaft (63), the end of the feed connecting shaft (63) is fixedly provided with a sliding block part (631), and the main feed transmission member (71) is provided with a stitch length adjustment sliding groove (711) slidably connected with the sliding block part (631); the main feed mechanism further includes a main feed transmission unit connected between the feed connecting shaft (63) and the main feed rack (21); and the differential feed mechanism further includes a differential feed transmission unit connected between the feed connecting shaft (63) and the differential feed rack (23).

15. The sewing machine adjustment method of claim 14, wherein: The main feed transmission unit includes a main feed connecting rod (72), a main feed lever (73) with a fixed rotation fulcrum, and a main feed sliding block (74), one end of the main feed connecting rod (72) is rotatably connected with the feed connecting shaft (63), the other end of the main feed connecting rod (72) is hingedly connected with the main feed lever (73), the main feed sliding block (74) is rotatably installed on the main feed lever (73), and the main feed rack (21) is provided with a main feed sliding groove (211), and the main feed sliding block (74) is movably arranged in the main feed sliding groove (211).

16. The sewing machine adjustment method of claim 14, wherein: The differential feed transmission unit comprises a differential feed connecting rod (82), a differential feed lever (83), a differential adjustment slider (84), and a differential feed slider (85), one end of the differential feed connecting rod (82) is in rotational cooperation with the feed connecting shaft (63), the other end of the differential feed connecting rod (82) is hinged with the differential feed lever (83), the differential feed slider (85) is rotatably installed on the differential feed lever (83), the differential feed slider (85) is movably assembled in the differential feed slide groove (231) in the differential feed jaw (23); the differential feed lever (83) is provided with a differential adjustment slide groove (831) in sliding cooperation with the differential adjustment slider (84), and the differential feed transmission member (81) is a differential adjustment shaft in rotational cooperation with the differential adjustment slider (84), which constitutes the rotational fulcrum of the differential feed lever (83).

17. The sewing machine adjustment method of claim 16, wherein: The differential feed adjustment unit (50) comprises a differential adjustment eccentric shaft (51) and a differential adjustment connecting rod (52), the differential adjustment eccentric shaft (51) comprises a first shaft part (511) coaxially fixed with the differential feed adjustment gear (42) and a second shaft part (512) eccentrically arranged with the first shaft part (511), and the two ends of the differential adjustment connecting rod (52) are respectively in rotational cooperation with the second shaft part (512) and the differential adjustment shaft.

18. The sewing machine adjustment method of claim 10, wherein: The main shaft (10) is provided with a lifting jaw eccentric shaft section (102), the sewing machine further comprises a lifting jaw slider (90) rotatably sleeved on the lifting jaw eccentric shaft section (102), the main feed jaw (21) and the differential feed jaw (23) are both provided with a lifting jaw slide groove (25), and the lifting jaw slider (90) is movably assembled in the lifting jaw slide groove (25) of the main feed jaw (21) and the differential feed jaw (23).

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