A needle distance adjustment mechanism and sewing machine based on arc stepping motor

Abstract

The present invention provides a needle distance adjustment mechanism based on an arc stepping motor, comprising a main shaft, a tooth rack, a feed tooth, a feed mechanism, an arc stepping motor, and an adjusting transmission component. The arc stepping motor comprises a stator assembly which is in a non-360° arc shape as a whole, a rotor assembly matched with the stator assembly, and a motor shaft fixed with the rotor assembly. The motor shaft is connected to a feed transmission component in the feed mechanism through the adjusting transmission component. When the arc stepping motor is powered on, the motor shaft rotates through an angle, and the motor shaft changes the inclination angle of the feed transmission component through the adjusting transmission component to achieve needle distance adjustment. The present application adopts the arc stepping motor as a driving source for needle distance adjustment. The arc stepping motor does not generate large working noise when outputting, and can also avoid wear between mechanical structures, thereby ensuring the accuracy of needle distance adjustment, which is beneficial to reducing the cost and weight of the sewing machine.

Description

Technical Field

[0001] The invention relates to a needle distance adjusting mechanism based on an arc-shaped stepping motor.

[0002] The invention also relates to a sewing machine comprising the needle distance adjusting mechanism. Background Art

[0003] At present, in the process of using a sewing machine (such as a lockstitch sewing machine), the function of adjusting the stitch length is debugged by manually turning the stitch length adjustment stud and combining the mechanical method of the dial, and a mechanical mechanism of pulling the reverse stitch electromagnet back and forth is used during the reverse stitching process, so that the stitch length value switches between positive and negative numbers, such as a sewing machine disclosed in the specification of the Chinese invention patent application with application number 201810699812.8. However, the sewing machine has the following defects: when switching between forward stitching and reverse stitching, the rapid movement of the reverse stitch electromagnet will cause collision between mechanical structures, generating a large working noise, and at the same time, due to the impact wear, the adjustment accuracy of the sewing machine stitch length will be affected after long-term operation; in addition, since the distribution position of the dial in the sewing machine cannot achieve high-precision adjustment of the stitch length, the error of the stitch length adjustment is large, and it is difficult to achieve accurate positioning of the forward stitching and reverse stitching within the stitch length of 0.5mm, which ultimately causes problems such as poor sewing quality. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a needle distance adjustment mechanism based on an arc stepping motor, which avoids noise during the adjustment process and has low cost.

[0005] To achieve the above-mentioned purpose, the present invention provides a needle pitch adjustment mechanism based on an arc stepping motor, comprising a rotatable main shaft, a tooth frame, a feed tooth installed on the tooth frame, a feeding mechanism connected between the main shaft and the tooth frame, an arc stepping motor, and an adjusting transmission component, wherein the arc stepping motor comprises a stator assembly that is an overall non-360° arc shape, a rotor assembly that matches the stator assembly, and a motor shaft that is fixed to the rotor assembly, wherein the motor shaft is connected to a feeding transmission component in the feeding mechanism through the adjusting transmission component; when the arc stepping motor is energized, the motor shaft rotates through an angle, and the motor shaft changes the inclination angle of the feeding transmission component through the adjusting transmission component.

[0006] Furthermore, the needle pitch adjustment mechanism also includes a bottom plate and an oil sealing plate fixed to the lower end of the bottom plate, the arc stepping motor is located in the oil sealing plate, and the outside of the stator assembly is wrapped with a sealing layer.

[0007] Furthermore, the feeding mechanism includes a feeding shaft parallel to the main shaft, a first feeding transmission assembly connected between the main shaft and the feeding shaft, and a second feeding transmission assembly connected between the feeding shaft and the tooth frame, and the feeding transmission component is a transmission component in the first feeding transmission assembly.

[0008] Furthermore, the first feeding transmission assembly includes a feeding eccentric wheel fixed on the main shaft, a feeding connecting rod, a feeding swing seat with a fixed swing fulcrum, a first feeding swing plate, a second feeding swing plate, and a feeding crank fixed on the feeding shaft, one end of the feeding connecting rod is rotatably mounted on the outer periphery of the feeding eccentric wheel, the other end of the feeding connecting rod, one end of the first feeding swing plate, and one end of the second feeding swing plate are coaxially hinged, the other end of the first feeding swing plate is hinged to the feeding swing seat, the other end of the second feeding swing plate is hinged to the feeding crank, and the motor shaft is connected to the feeding swing seat through an adjusting transmission assembly.

[0009] Furthermore, the adjusting transmission assembly includes an adjusting crank fixed to the motor shaft, and an adjusting connecting rod, and two ends of the adjusting connecting rod are respectively connected to the adjusting crank and the feeding transmission component.

[0010] Furthermore, the adjusting connecting rod and the adjusting crank, and the adjusting connecting rod and the feeding transmission component are hinged via a connecting pin parallel to the main shaft.

[0011] Furthermore, the stator assembly includes a stator body in a non-360° arc shape, a mounting cavity formed on the inner circumferential side of the stator body, wire slots provided on the inner circumferential surface of the stator body facing the rotor assembly, and stator windings installed in the wire slots, and the rotor assembly is installed in the mounting cavity. The rotor assembly includes a rotor body fixed to the motor shaft and transverse magnetic steel extending radially along the motor shaft.

[0012] Furthermore, the sealing layer is a glue-filled layer formed after the stator assembly is treated with glue.

[0013] Furthermore, the arc-shaped stepper motor also includes a front end cover and a rear end cover respectively fixed at the front and rear ends of the stator assembly, and the motor shaft is rotatably supported in the front end cover and the rear end cover.

[0014] Furthermore, the stitch length adjusting mechanism also includes a motor mounting plate fixed to both the front end cover and the rear end cover, and the motor mounting plate is fixed to the lower end surface of the bottom plate of the sewing machine.

[0015] Furthermore, the arc stepper motor also includes an encoder assembly, which includes a detection magnet fixed to the motor shaft, a linear Hall sensor fixed to the front cover or the rear cover, and a signal processor connected to the linear Hall sensor, and the detection magnet cooperates with the linear Hall sensor.

[0016] The present application also provides a sewing machine, in which the stitch length adjusting mechanism as described above is installed.

[0017] As described above, the stitch distance adjustment mechanism and sewing machine based on the arc-shaped stepping motor according to the present invention have the following beneficial effects:

[0018] The present application can change the inclination angle of the feeding transmission component, thereby changing the movement amplitude of the main shaft driving the tooth rack and the feeding tooth to reciprocate back and forth through the feeding mechanism, thereby realizing stitch length adjustment; in particular, an arc-shaped stepper motor is used as the driving source for stitch length adjustment. The arc-shaped stepper motor will not generate a large working noise during output, and can also avoid wear between mechanical structures, thereby ensuring the accuracy of stitch length adjustment; at the same time, the arc-shaped stepper motor, under the premise of meeting the swing angle of the motor shaft required for stitch length adjustment, uses less material, volume and weight than ordinary stepper motors. The arc-shaped stepper motor can be better applied to sewing machines, which is beneficial to reducing the cost and weight of sewing machines. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figures 1 to 3 Schematic diagram of the structure of the sewing machine in this application at different viewing angles.

[0020] (in, Figure 2 Omitted Figure 1 The bottom plate in Figure 3 Omitted Figure 1 The oil seal in the .

[0021] Figure 4 and Figure 5 Schematic diagram of the connection between the main shaft, feeding mechanism, tooth rack, feeding tooth, arc stepping motor, and adjustment transmission assembly in this application at different viewing angles.

[0022] Figure 6 for Figure 5 Enlarged view of circle I.

[0023] Figure 7 This is a schematic diagram of the structure of the arc stepping motor embodiment 1 in the present application.

[0024] Figure 8 for Figure 7 Schematic diagram of the structure of the stator assembly, rotor assembly, and motor shaft. The sealing layer of the stator assembly is omitted in this figure.

[0025] Fig. 9 for Figure 7 Schematic diagram of the structure of the middle stator assembly after glue filling.

[0026] Fig.10 for Figure 7 Schematic diagram of the structure of the middle stator assembly before glue filling.

[0027] Fig.11 for Fig.10 Enlarged view of circle A.

[0028] Fig.12 for Fig.10 Side view of.

[0029] Fig.13 for Fig.12 Enlarged view of circle B.

[0030] Fig.14 for Figure 7 Schematic diagram of the structure of the middle rotor assembly after glue filling.

[0031] Fig.15 for Figure 7 Schematic diagram of the connection between the motor shaft, front cover and rear cover.

[0032] Fig.16 This is a schematic diagram of the structure of the arc stepping motor embodiment 2 in this application.

[0033] Fig.17 for Fig.16 Schematic diagram of the structure of the encoder assembly.

[0034] Component number description

[0035] 100 Spindle

[0036] 200 Tooth frame

[0037] 300 feed dog

[0038] 400 Feeding mechanism

[0039] 41 Feed shaft

[0040] 42 Feed eccentric wheel

[0041] 43 Feed connecting rod

[0042] 44 Feeding swing seat

[0043] 441 Seat Arm

[0044] 45 First feeding swing plate

[0045] 46 Second feeding swing plate

[0046] 47 Feed crank

[0047] 48 Support pin

[0048] 500 Base Plate

[0049] 600 Oil seal tray

[0050] 700 Arc Stepper Motor

[0051] 71 Motor shaft

[0052] 711 Second step

[0053] 712 Third step

[0054] 72 stator assembly

[0055] 721 stator body

[0056] 7211 Wire Trough

[0057] 7212 Gap

[0058] 722 Mounting cavity

[0059] 723 Stator winding

[0060] 724 longitudinal magnetic steel

[0061] 725 ridges

[0062] 7251 body part

[0063] 7252 convex tooth

[0064] 7253 Tooth

[0065] 73 rotor assembly

[0066] 731 Rotor

[0067] 732 Transverse Magnetic Steel

[0068] 74 Sealing layer

[0069] 75 Front cover

[0070] 751 Shaft hole

[0071] 752 First step

[0072] 76 rear end cover

[0073] 77 Encoder assembly

[0074] 771 Detection Magnet

[0075] 772 Linear Hall Sensor

[0076] 773 Signal Processor

[0077] 774 Magnet Mounting Bracket

[0078] 775 Hall Mounting Bracket

[0079] 776 Connecting wire

[0080] 800 Adjustment drive assembly

[0081] 81 Adjusting crank

[0082] 82 Adjusting connecting rod

[0083] 900 Motor mounting plate DETAILED DESCRIPTION

[0084] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0085] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0086] The present application provides a sewing machine, which is a flat sewing machine; Figure 1 and Figure 2 As shown, the sewing machine has a main shaft 100 driven to rotate by a main motor. For the convenience of description, in the following embodiments, the definitions of various directions are as follows: the axial direction of the main shaft 100 is defined as the left-right direction, and the direction of the main shaft 100 toward the head of the sewing machine is the left direction, and the direction of the main shaft 100 toward the tail of the sewing machine is the right direction; the direction in which the feed dog 300 drives the sewing material to move when the sewing machine is sewing is defined as the front direction; the direction orthogonal to both the left-right direction and the front-back direction is defined as the up-down direction.

[0087] like Figure 1 and Figure 2As shown, the sewing machine includes a main shaft 100 rotatably supported in a casing, a tooth frame 200, a feed tooth 300 fixedly mounted on the tooth frame 200, a feeding mechanism 400 connected between the main shaft 100 and the front end of the tooth frame 200, a tooth lifting mechanism connected between the main shaft 100 and the rear end of the tooth frame 200, a bottom plate 500 fixed to the casing, and an oil sealing plate 600 fixed to the lower end of the bottom plate 500. When the main shaft 100 rotates, the main shaft 100 drives the tooth frame 200 and the feed tooth 300 to perform a back-and-forth reciprocating motion together through the feeding mechanism 400, and the main shaft 100 drives the tooth frame 200 and the feed tooth 300 to perform an up-and-down reciprocating motion together through the tooth lifting mechanism, so the feed tooth 300 performs a compound motion of a back-and-forth reciprocating motion and an up-and-down reciprocating motion, and the motion trajectory of the feed tooth 300 is similar to an ellipse, and the feed tooth 300 cooperates with the presser foot in the sewing machine to move the sewing material forward.

[0088] Furthermore, a stitch length adjustment mechanism is installed in the sewing machine, such as Figures 1 to 3 As shown, the needle distance adjustment mechanism includes not only the spindle 100, tooth frame 200, feed tooth 300, feed mechanism 400, bottom plate 500 and oil sealing plate 600, but also an arc stepping motor 700 and an adjustment transmission assembly 800. The arc stepping motor 700 is located in the oil sealing plate 600. Figures 7 to 10 As shown, the arc stepper motor 700 includes a stator assembly 72 that is not in a 360° arc shape, a rotor assembly 73 that matches the stator assembly 72, and a motor shaft 71 that is fixed to the rotor assembly 73. The outside of the stator assembly 72 is wrapped with a sealing layer 74, and the sealing layer 74 covers the stator assembly 72. The components in the stator assembly 72 will not be exposed, so that the stator assembly 72 has the characteristics of oil resistance and anti-thread hair interference, that is, lubricating oil, thread hair, etc. will not enter the interior of the stator assembly 72, and then the arc stepper motor 700 as a whole has the characteristics of oil resistance and anti-thread hair interference, so that the arc stepper motor 700 can be installed inside the oil sealing plate 600 of the sewing machine. Figure 4 and Figure 5 As shown, the motor shaft 71 is connected to a feeding transmission component in the feeding mechanism 400 through the adjusting transmission assembly 800.

[0089] When the sewing machine is sewing normally, the arc-shaped stepper motor 700 is not powered on, the arc-shaped stepper motor 700 does not output angular displacement, the rotation angle of the motor shaft 71 remains unchanged and maintains the current rotation angle, the motor shaft 71 keeps the feeding transmission component at the current position by adjusting the transmission assembly 800, and the inclination angle of the feeding transmission component does not change. The main motor drives the main shaft 100 to rotate, and the main shaft 100 drives the tooth frame 200 and the feed tooth 300 to reciprocate forward and backward through the feeding mechanism 400. When the stitch length needs to be adjusted, the arc-shaped stepper motor 700 is powered on, the arc-shaped stepper motor 700 outputs angular displacement, the motor shaft 71 rotates an angle, and the motor shaft 71 changes the inclination angle of the feeding transmission component by adjusting the transmission assembly 800; when the sewing machine is running subsequently, the main shaft 100 drives the tooth frame 200 and the feed tooth 300 to reciprocate forward and backward through the feeding mechanism 400, thereby realizing the stitch length adjustment. In particular, an arc-shaped stepper motor 700 is used as a driving source for adjusting the stitch length. The arc-shaped stepper motor 700 does not generate a large working noise when outputting, and can also avoid wear between mechanical structures, thereby ensuring the accuracy of stitch length adjustment. At the same time, the arc-shaped stepper motor 700, while meeting the swing angle of the motor shaft 71 required for stitch length adjustment, uses less material, volume and weight than ordinary stepper motors, that is, the cost of the arc-shaped stepper motor 700 and the required installation space are greatly reduced, so that the arc-shaped stepper motor 700 can be better applied to sewing machines, which is beneficial to reducing the cost and weight of sewing machines. In addition, the arc-shaped stepper motor 700 has oil-proof properties, and the present application installs the arc-shaped stepper motor 700 in the oil sealing tray 600 of the sewing machine, so that the arc-shaped stepper motor 700 works in an oily environment. At this time, when the lubricating oil in the sewing machine drips into the oil sealing tray 600, it will also drip onto the arc-shaped stepper motor 700, which can take away the heat of the arc-shaped stepper motor 700. The oil sealing tray 600 made of aluminum is more conducive to the heat dissipation of the arc-shaped stepper motor 700.

[0090] The preferred structure of the feeding mechanism 400 is as follows: Figures 4 to 6As shown, the feeding mechanism 400 includes a feeding shaft 41 parallel to the main shaft 100, a first feeding transmission assembly connected between the main shaft 100 and the feeding shaft 41, and a second feeding transmission assembly connected between the feeding shaft 41 and the tooth frame 200. The feeding shaft 41 is rotatably mounted in the base plate 500, and the feeding transmission component is a transmission component in the first feeding transmission assembly. The first feeding transmission assembly includes a feeding eccentric wheel 42 fixed on the main shaft 100 by screws, a feeding connecting rod 43, a feeding swing seat 44 with a fixed swing fulcrum, a first feeding swing plate 45, a second feeding swing plate 46, and a feeding crank 47 fixed on the feeding shaft 41 by screws. The upper end of the feeding connecting rod 43 is rotatably mounted on the outer periphery of the feeding eccentric wheel 42, and the lower end of the feeding connecting rod 43, the rear end of the first feeding swing plate 45, and the rear end of the second feeding swing plate 46 are coaxially hinged by a connecting pin extending left and right. The front end of the first feeding swing plate 45 is hinged to the feeding swing seat 44 by a connecting pin extending left and right, and the front end of the second feeding swing plate 46 is hinged to the feeding crank 47 by a connecting pin extending left and right. The motor shaft 71 is connected to the feeding swing seat 44 through the adjusting transmission assembly 800, so the feeding swing seat 44 constitutes the above-mentioned feeding transmission component. When the arc stepper motor 700 is not powered, the inclination angle of the feed swing seat 44 is maintained, and the swing amplitude of the feed shaft 41 driven by the main shaft 100 through the first feed transmission assembly remains unchanged, that is, the transmission efficiency of the first feed transmission assembly remains unchanged. When the arc stepper motor 700 is powered, the motor shaft 71 of the arc stepper motor 700 drives the feed swing seat 44 to rotate an angle around its fixed swing fulcrum through the adjustment transmission assembly 800, and the swing amplitude of the feed shaft 41 driven by the main shaft 100 through the first feed transmission assembly changes, that is, the transmission efficiency of the first feed transmission assembly changes, and the feed shaft 41 drives the tooth frame 200 and the feed tooth 300 to reciprocate back and forth through the second feed transmission assembly. The motion amplitude will also change, thereby realizing needle spacing adjustment. The second feed transmission assembly is a prior art, and the Chinese invention patent specification with application number 201510640562.7 can be referred to, so the second feed transmission assembly will not be described in detail here.

[0091] Preferably, if Figure 6As shown, the feed swing seat 44 has two seat arms 441 arranged opposite to each other, and there are two first feed swing plates 45 and two second feed swing plates 46. The two second feed swing plates 46 are arranged on the left and right sides of the feed crank 47 and between the two seat arms 441 of the feed swing seat 44, respectively. A first feed swing plate 45 is arranged between the seat arm 441 of the feed swing seat 44 and the second feed swing plate 46. Each seat arm 441 is rotatably mounted with a support pin 48 extending left and right on the outer side facing away from the first feed swing plate 45. The support pin 48 is fixed in the bottom plate 500. The feed swing seat 44 can rotate around the support pin 48, and the support pin 48 constitutes a fixed swing fulcrum of the feed swing seat 44.

[0092] Further, the preferred structure of the adjustment transmission assembly 800 is as follows: Figures 4 to 6 As shown, the adjustment transmission assembly 800 includes an adjustment crank 81 fixed to the motor shaft 71 by screws, and an adjustment connecting rod 82, and the two ends of the adjustment connecting rod 82 are respectively connected to the adjustment crank 81 and the feed swing seat 44. Preferably, the motor shaft 71 is parallel to the main shaft 100, and the adjustment connecting rod 82 and the adjustment crank 81, and the adjustment connecting rod 82 and the feed swing seat 44 are hinged by a connecting pin parallel to the main shaft 100, and the adjustment crank 81 and the adjustment connecting rod 82 are both located in the oil sealing plate 600. When the motor shaft 71 rotates an angle, the adjustment crank 81 is driven to rotate the same angle, and the feed swing seat 44 is driven to rotate an angle around the support pin 48 through the adjustment connecting rod 82, so as to change the inclination angle of the feed swing seat 44, so that the feed swing seat 44 rotates to the corresponding position according to the preset parameter needle distance value and remains at this position, so as to achieve needle distance adjustment. When the sewing machine is running, the main shaft 100 drives the tooth frame 200 and the feed tooth 300 to feed according to the preset parameter stitch value through the feeding mechanism 400. Therefore, when it is necessary to reverse the stitch (i.e., the stitch positive and negative switching), or pattern sewing (i.e., the stitch size change), or dense stitch (i.e., small stitch stitch), the user inputs the corresponding command through the operation panel on the sewing machine, and the electric control module in the sewing machine sends the corresponding command signal to the arc stepping motor 700 after receiving the command, and the motor shaft 71 changes the angle of the feed swing seat 44 by adjusting the crank 81 and the adjusting connecting rod 82, thereby changing the working stitch of the sewing machine, achieving the sewing effect of reverse stitching, pattern sewing, or dense stitching, and having strong intelligent adjustment ability. In addition, the adjustment transmission assembly 800 in the present application is composed of two components, namely an adjustment crank 81 and an adjustment connecting rod 82. It has a simple structure and there are no impact and noise problems during the adjustment process. The force transmission of the adjustment transmission assembly 800 is all within the same plane. It has a stable structure, is easy to install, and has low parts cost, which is conducive to ensuring the accuracy of needle spacing adjustment.

[0093] The following describes the preferred structure of the arc stepper motor 700 involved in the present application.

[0094] Arc-shaped stepping motor 700 Embodiment 1

[0095] like Figures 10 to 12 As shown, the stator assembly 72 includes a stator body 721 and a stator winding 723. The stator body 721 is in a non-360° arc shape, so an installation cavity 722 is formed on the inner circumferential side of the stator body 721, and the stator body 721 has a notch 7212 in its circumferential direction, that is, the stator body 721 is an arc-shaped stator body 721 with a notch 7212 in the circumferential direction; a plurality of wire slots 7211 extending forward and backward along the axial direction of the motor shaft 71 and arranged at intervals along the circumferential direction of the stator body 721 are provided on the inner circumferential surface of the stator body 721 facing the rotor assembly 73, and the stator winding 723 is fixedly installed in the wire slots 7211 of the stator body 721. Based on the stator body 721 with a non-360° arc structure, the stator windings 723 installed in the inner peripheral slots 7211 of the stator body 721 are also arranged in a non-360° arc shape, and the stator assembly 72 as a whole is also in a non-360° arc shape. The installation cavity 722 is also formed on the inner peripheral side of the stator assembly 72 facing the rotor assembly 73. Figure 8 As shown, the rotor assembly 73 of the arc stepper motor 700 is installed in the installation cavity 722 of the stator body 721 in the stator assembly 72; Fig.10As shown, the rotor assembly 73 includes a rotor body 731 fixed to the motor shaft 71 and a transverse magnetic steel 732 extending radially along the motor shaft 71, so the rotor body 731 and the transverse magnetic steel 732 are both installed in the installation cavity 722. When the arc stepper motor 700 is powered on, the current flows through the stator winding 723, and the stator winding 723 generates a vector magnetic field, which drives the rotor body 731 and the transverse magnetic steel 732 to rotate by an angle, so that the magnetic field direction of the rotor body 731 is consistent with the magnetic field direction of the stator body 721; when the vector magnetic field of the stator body 721 rotates by an angle, the rotor body 731 rotates by an angle with the magnetic field, and the rotor body 731 drives the motor shaft 71 to rotate by the same angle. For each input of an electric pulse, the motor shaft 71 rotates by an angle and moves forward one step. Therefore, the angular displacement output by the arc stepper motor 700 is proportional to the number of input pulses, and the speed output by the arc stepper motor 700 is proportional to the pulse frequency. By changing the power-on sequence of the stator windings 723, the motor shaft 71 of the arc stepper motor 700 will be reversed. The output of the arc stepper motor 700 is controlled by controlling the pulse quantity, frequency and the power-on sequence of the stator windings 723 of each phase in the stator assembly 72. In particular, in the present application, the stator body 721 of the non-360° arc structure makes the stator assembly 72 as a whole present a non-360° arc shape, and several stator windings 723 are arranged in a non-360° arc shape, so the motor shaft 71 can only swing within a certain angle and does not perform a 360° rotation motion, but the swinging of the motor shaft 71 within a certain angle can meet the needs of most application occasions in industrial sewing machines, such as: as a driving source for adjusting the stitch length, a driving source for adjusting the tooth lifting height, a driving source for the presser foot lifting mechanism, etc. After the stator body 721 and the stator assembly 72 in the arc stepper motor 700 are both in a non-360° arc shape, under the premise that the arc stepper motor 700 can meet the needs of most application scenarios in industrial sewing machines, the stator body 721 and the stator assembly 72 with a non-360° arc structure can greatly reduce the consumables, weight, and volume of the arc stepper motor 700, greatly reduce the cost and installation space, and are very suitable for industrial sewing machines, which is beneficial to saving space and volume of industrial sewing machines and also beneficial to reducing the cost of industrial sewing machines.

[0096] Furthermore, if Figures 10 to 13 As shown, the stator assembly 72 also includes a longitudinal magnetic steel 724 fixed to the stator body 721 and extending axially along the motor shaft 71; by providing the longitudinal magnetic steel 724, the magnetic line cutting can be increased. Under the condition of outputting the same torque, the present application can make the volume of the arc stepping motor 700 smaller, thereby increasing the performance of the arc stepping motor 700. Preferably, the formation structure of the line slot 7211 in the stator assembly 72 and the installation structure of the longitudinal magnetic steel 724 are preferably: Figures 10 to 13As shown, a plurality of convex strips 725 arranged at intervals in the circumferential direction and protruding in the radial direction are provided on the inner circumferential surface of the stator body 721 facing the rotor assembly 73, and the convex strips 725 extend forward and backward along the axial direction of the motor shaft 71; each convex strip 725 includes a main body portion 7251 extending forward and backward, a plurality of convex tooth portions 7252 extending from one end of the main body portion 7251 away from the stator body 721 toward the direction close to the rotor assembly 73, and a tooth groove 7253 formed between two adjacent convex tooth portions 7252, and a plurality of convex tooth portions 7252 at the end of each convex strip 725 are arranged at intervals in the circumferential direction of the stator body 721, and each convex tooth portion 7252 extends forward and backward along the axial direction of the motor shaft 71, so the tooth groove 7253 also extends forward and backward along the axial direction of the motor shaft 71, and the longitudinal magnetic steel 724 is fixedly installed in the tooth groove 7253, and a wire groove 7211 is formed between the main body portions 7251 of two adjacent convex strips 725. At least one longitudinal magnetic steel 724 may be installed in each tooth slot 7253 ; when a plurality of longitudinal magnetic steels 724 are installed in the tooth slot 7253 , the plurality of longitudinal magnetic steels 724 are arranged front to back along the axial direction of the motor shaft 71 .

[0097] Furthermore, if Fig.14 As shown, there are two rotor bodies 731, which are arranged in a front-to-back manner along the axial direction of the motor shaft 71, and the transverse magnetic steel 732 is arranged between the two rotor bodies 731. The rotor assembly 73 as a whole can be in a 360° cylindrical shape or in a fan shape; in this embodiment, the rotor assembly 73 as a whole is in a fan shape, so the rotor body 731 and the transverse magnetic steel 732 are both in a fan shape, which can further save the material, weight and volume of the arc stepper motor 700. In addition, as Fig. 9 As shown, the effective arc of the stator assembly 72 is θ, and the effective arc θ of the stator assembly 72 is also the arc occupied by the plurality of stator windings 723; Fig.14 As shown, the effective curvature of the rotor assembly 73 is β, which is also the curvature of the rotor body 731 and the transverse magnetic steel 732 ; when the rotor body 731 and the transverse magnetic steel 732 are both fan-shaped, the effective curvature β of the rotor assembly 73 is greater than the effective curvature θ of the stator assembly 72 .

[0098] Preferably, the sealing layer 74 wrapped around the outside of the stator assembly 72 is formed by performing a glue pouring treatment on the stator assembly 72, and then a glue pouring layer is formed on the outside of the stator assembly 72, and the glue pouring layer is the sealing layer 74. The sealing layer 74 wraps the stator assembly 72, and the various components in the stator assembly 72 (including the stator body 721, the wire slot 7211, the stator winding 723, the convex strip 725, the tooth slot 7253 and the longitudinal magnetic steel 724) are not exposed. In addition, after the stator assembly 72 is poured with glue, while the sealing layer 74 is formed on the periphery, the stator winding 723 can be fixed in the wire slot 7211 and the longitudinal magnetic steel 724 can be fixed in the tooth slot 7253, and it is also more convenient for heat conduction.

[0099] Furthermore, if Figure 7 As shown, the arc stepper motor 700 also includes a front end cover 75 and a rear end cover 76 respectively fixed at the front and rear ends of the stator assembly 72 by screws, and the motor shaft 71 is rotatably supported in the front end cover 75 and the rear end cover 76. The present application uses the front end cover 75 and the rear end cover 76 to directly support the motor shaft 71, eliminating the structure of using bearings to support the motor shaft 71, and further reducing costs. In addition, the front end cover 75 and the rear end cover 76 can be made of oil-containing materials to achieve self-lubrication; or, the front end cover 75 and the rear end cover 76 can also be made of non-oil-containing materials, but the characteristic of the arc stepper motor 700 being installed in the oil sealing plate 600 of the sewing machine is utilized to achieve lubrication through oil mist. Preferably, as Fig.15 As shown, the front end cover 75 and the rear end cover 76 are both provided with an axial hole 751 for supporting the motor shaft 71, and the axial hole 751 is a stepped hole, that is, the front end cover 75 and the rear end cover 76 have a first step portion 752 on the hole wall of their respective axial holes 751, and the motor shaft 71 has a second step portion 711 engaged with the first step portion 752 in the front end cover 75, and a third step portion 712 engaged with the first step portion 752 in the rear end cover 76, which can prevent axial movement of the motor shaft 71.

[0100] Preferably, if Figure 2 and Figure 3 As shown, the needle distance adjustment mechanism also includes a motor mounting plate 900, which is fixedly connected to the front end cover 75 and the rear end cover 76 of the arc stepper motor 700 by screws. The motor mounting plate 900 is fixed to the lower end surface of the base plate 500 by screws, and the arc stepper motor 700 is fixedly installed as a whole on the lower end surface of the base plate 500, which can improve the stability of the overall structure and save space.

[0101] Arc-shaped stepping motor 700 Embodiment 2

[0102] The difference between the arc-shaped stepping motor 700 embodiment 2 and the arc-shaped stepping motor 700 embodiment 1 is that the arc-shaped stepping motor 700 embodiment 2 further adds an encoder assembly 77 on the basis of the arc-shaped stepping motor 700 embodiment 1. Therefore, the arc-shaped stepping motor 700 embodiment 1 is a non-closed-loop arc-shaped stepping motor 700, and the arc-shaped stepping motor 700 embodiment 2 is a closed-loop arc-shaped stepping motor 700. The encoder assembly 77 can determine the rotation angle of the motor shaft 71, play a positioning role, ensure the accuracy of the arc-shaped stepping motor 700, and improve the precision and accuracy of the needle distance adjustment.

[0103] The second embodiment of the arc stepping motor 700 includes all the structures of the first embodiment of the arc stepping motor 700 and the encoder assembly 77. Fig.16As shown, the arc stepping motor 700 of the second embodiment includes a stator assembly 72 which is in a non-360° arc shape, a rotor assembly 73 matched with the stator assembly 72, and a motor shaft 71 fixed with the rotor assembly 73. The encoder assembly 77 is a magnetic encoder, such as Fig.17 As shown, the encoder assembly 77 includes a detection magnet 771, a magnet mounting bracket 774, a linear Hall sensor 772, a Hall mounting bracket 775, a connecting wire 776, and a signal processor 773; wherein the detection magnet 771 is fixedly mounted on the magnet mounting bracket 774, the magnet mounting bracket 774 is fixed to the motor shaft 71, and the detection magnet 771 is then fixed to the motor shaft 71; the linear Hall sensor 772 is fixedly mounted on the Hall mounting bracket 775, the Hall mounting bracket 775 is fixed to the front end cover 75 or the rear end cover 76, and the linear Hall sensor 772 is then fixed to the front end cover 75 or the rear end cover 76; the linear Hall sensor 772 is connected to the signal processor 773 through the connecting wire 776; the detection magnet 771 cooperates with the linear Hall sensor 772. The linear Hall sensor 772 is distributed on the central axis of the motor shaft 71, and the sensitive surface of the linear Hall sensor 72 is parallel to the central axis of the motor shaft 10, and the detection magnet 771 is distributed on the outer side of the linear Hall sensor 772 along the radial direction of the motor shaft 71. Fig.16 and Fig.17 In the second embodiment of the arc stepper motor 700 shown, the Hall mounting bracket 775 is fixed to the rear end cover 76, so that the linear Hall sensor 772 is fixed to the rear end cover 76. When the motor shaft 71 rotates, the motor shaft 71 drives the magnet mounting bracket 774 and the detection magnet 771 to rotate at the same angle, and the linear Hall sensor 772 detects the magnetic field formed by the detection magnet 771, thereby outputting a changing voltage signal. The signal processor 773 calculates the rotation position of the magnet mounting bracket 774 and the detection magnet 771 according to the voltage signal output by the linear Hall sensor 772, that is, calculates the rotation angle of the motor shaft 71. The encoder assembly 77 in the present application is a non-contact detection, which has high detection accuracy, low cost, convenient installation, and simple debugging. It is very suitable for some use environments that require low cost and high precision, and is particularly suitable for the measurement of the rotation position with a small rotation angle, that is, it is particularly suitable for the arc stepper motor 700 in the present application.

[0104] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0105] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A needle distance adjustment mechanism based on an arc stepping motor, comprising a rotatable main shaft (100), a tooth frame (200), a feed tooth (300) mounted on the tooth frame (200), and a feed mechanism (400) connected between the main shaft (100) and the tooth frame (200), characterized in that: The invention also comprises an arc-shaped stepping motor (700) and an adjusting transmission assembly (800), wherein the arc-shaped stepping motor (700) comprises a stator assembly (72) which is in a non-360° arc shape as a whole, a rotor assembly (73) which matches the stator assembly (72), and a motor shaft (71) which is fixed to the rotor assembly (73), wherein the motor shaft (71) is connected to a feeding transmission component in the feeding mechanism (400) through the adjusting transmission assembly (800); when the arc-shaped stepping motor (700) is powered on, the motor shaft (71) rotates through an angle, and the motor shaft (71) changes the inclination angle of the feeding transmission component through the adjusting transmission assembly (800); The needle distance adjustment mechanism also includes a base plate (500) and an oil sealing plate (600) fixed at the lower end of the base plate (500); the arc stepping motor (700) is located in the oil sealing plate (600); the stator assembly (72) is wrapped with a sealing layer (74) on the outside; the feeding mechanism (400) includes a feeding shaft (41) parallel to the main shaft (100), a first feeding transmission assembly connected between the main shaft (100) and the feeding shaft (41), and a second feeding transmission assembly connected between the feeding shaft (41) and the tooth frame (200); the feeding transmission component is a transmission component in the first feeding transmission assembly; the first feeding transmission assembly includes a feeding eccentric wheel (42) fixed on the main shaft (100), a feeding connecting rod (41) and a feeding connecting rod (42). (43), a feeding swing seat (44) with a fixed swing fulcrum, a first feeding swing plate (45), a second feeding swing plate (46), and a feeding crank (47) fixed on the feeding shaft (41), one end of the feeding connecting rod (43) is rotatably mounted on the outer periphery of the feeding eccentric wheel (42), the other end of the feeding connecting rod (43), one end of the first feeding swing plate (45), and one end of the second feeding swing plate (46) are coaxially hinged, the other end of the first feeding swing plate (45) is hinged to the feeding swing seat (44), the other end of the second feeding swing plate (46) is hinged to the feeding crank (47), and the motor shaft (71) is connected to the feeding swing seat (44) through an adjusting transmission component (800).

2. The needle distance adjustment mechanism according to claim 1, characterized in that: The adjusting transmission assembly (800) comprises an adjusting crank (81) fixed to the motor shaft (71), and an adjusting connecting rod (82), and the two ends of the adjusting connecting rod (82) are respectively connected to the adjusting crank (81) and the feeding transmission component.

3. The needle distance adjustment mechanism according to claim 2, characterized in that: The adjusting connecting rod (82) and the adjusting crank (81), and the adjusting connecting rod (82) and the feeding transmission component are both hingedly connected via a connecting pin parallel to the main shaft (100).

4. The needle distance adjustment mechanism according to claim 1, characterized in that: The stator assembly (72) comprises a stator body (721) in a non-360° arc shape, a mounting cavity (722) formed on the inner circumference of the stator body (721), a wire slot (7211) provided on the inner circumference of the stator body (721) facing the rotor assembly (73), and a stator winding (723) mounted in the wire slot (7211); the rotor assembly (73) is mounted in the mounting cavity (722); and the rotor assembly (73) comprises a rotor body (731) fixed to the motor shaft (71) and a transverse magnetic steel (732) extending radially along the motor shaft (71).

5. The needle distance adjustment mechanism according to claim 1, characterized in that: The sealing layer (74) is a glue-filled layer formed after the stator assembly (72) is subjected to a glue-filling treatment.

6. The needle distance adjustment mechanism according to claim 1, characterized in that: The arc-shaped stepping motor (700) further comprises a front end cover (75) and a rear end cover (76) respectively fixed at the front and rear ends of the stator assembly (72), and the motor shaft (71) is rotatably supported in the front end cover (75) and the rear end cover (76).

7. The needle distance adjustment mechanism according to claim 6, characterized in that: It also includes a motor mounting plate (900) fixed to both the front end cover (75) and the rear end cover (76); the motor mounting plate (900) is fixed to the lower end surface of the bottom plate (500) in the sewing machine.

8. The needle distance adjustment mechanism according to claim 6, characterized in that: The arc stepping motor (700) further comprises an encoder assembly (77), wherein the encoder assembly (77) comprises a detection magnet (771) fixed to the motor shaft (71), a linear Hall sensor (772) fixed to the front end cover (75) or the rear end cover (76), and a signal processor (773) connected to the linear Hall sensor (772), wherein the detection magnet (771) cooperates with the linear Hall sensor (772).

9. A sewing machine, characterized in that: The sewing machine is equipped with a needle distance adjustment mechanism according to any one of claims 1 to 8.

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