Presser foot lifting height adjusting mechanism, presser foot lifting mechanism and sewing machine thereof

Abstract

The embodiment of the utility model provides a presser foot lifting height adjusting mechanism, a presser foot lifting mechanism and a sewing machine thereof.The presser foot lifting height adjusting mechanism comprises a transmission assembly and a driving device which is connected with a crank lever assembly in a drivable mode and provides rotation driving force for the crank lever assembly; the crank lever assembly is in transmission connection between the transmission assembly and the driving device, and is used for transmitting the rotary driving force to the transmission assembly and driving the presser foot assembly to execute the presser foot lifting action through the transmission assembly; the crank lever assembly comprises a cam, a crank assembly and a presser foot lifting pull rod, the cam under rotary motion acts on a second eccentric part of the crank assembly, the crank assembly continuously amplifies driving torque acting on the presser foot lifting pull rod during rotation, and after the presser foot lifting pull rod drives the transmission assembly to rotate, the transmission assembly drives the presser foot assembly to execute lifting and pressing actions. Therefore, the technical effects of reducing driving energy consumption, saving energy and improving efficiency are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of sewing equipment, and in particular to a presser foot lift height adjustment mechanism, a presser foot lift mechanism and a sewing machine thereof. Background Art

[0002] A sewing machine is a machine that forms sewing patterns on sewing materials. Stitch Sewing equipment used to sew one or more layers of fabric together is widely used in daily life. The component that directly sews the fabric is the presser foot lifter. This mechanism controls the presser foot assembly's lift height, performing a reciprocating lift and press motion to achieve the desired stitching effect.

[0003] At present, the presser foot lifting mechanism on the market that can control the presser foot height mainly adopts a stepper motor to drive a sliding driven part to adjust the presser foot height. Although the presser foot height can be adjusted, the complex sliding structure between the driving structural parts results in high energy consumption, and the energy loss of the stepper motor that provides power is large. In addition, the adjustment structure is relatively complicated, resulting in low efficiency and high cost. Utility Model Content

[0004] The embodiments of the present application provide a presser foot lift height adjustment mechanism, a presser foot lift mechanism and a sewing machine thereof, which have a simple structure, stable and efficient operation, and can significantly improve the technical problem of high driving energy consumption.

[0005] In a first aspect, an embodiment of the present application provides a presser foot lift height adjustment mechanism, comprising:

[0006] a driving device for drivably connecting to the crank lever assembly and providing a rotational driving force to the crank lever assembly;

[0007] a crank lever assembly connected to the drive device for transmitting the rotational driving force to the transmission assembly;

[0008] A transmission assembly, fixedly connected to the presser foot assembly and transmission-connected to the crank lever assembly, the transmission assembly being used to connect to the presser foot assembly, and the transmission assembly being configured to drive the presser foot assembly to perform a presser foot lifting action under the action of a rotational driving force;

[0009] The crank lever assembly includes: a cam, a crank assembly and a presser foot lifting connecting rod, the cam is fixedly arranged on the driving end of the driving device, the crank assembly is fixedly connected to an external device through a rotating part, and the first eccentric part and the second eccentric part on the crank assembly located on both sides of the rotating part are respectively rotatably connected to the presser foot lifting rod and the cam are transmission-connected, the cam under the rotating motion acts on the second eccentric part so that the crank assembly amplifies the driving torque acting on the presser foot lifting rod during rotation, and the presser foot lifting rod drives the transmission assembly to rotate and then drives the presser foot assembly to perform the lifting and pressing action.

[0010] In a possible implementation manner, a distance between a center of the second eccentric portion and a center of the rotating portion is greater than a distance between a center of the first eccentric portion and a center of the rotating portion.

[0011] In a possible embodiment, the crank assembly includes a presser foot lift crank, a bearing, a first locking member, a center locking member, and a second locking member;

[0012] The presser foot lifting crank comprises the rotating portion, a first crank rod radially extending horizontally from the rotating portion, the first eccentric portion provided at an end portion of the first crank rod, a second crank rod radially extending upward from the rotating portion, and a second eccentric portion provided at an end portion of the second crank rod;

[0013] The rotating part is provided with a rotating center hole, the first eccentric part is provided with a first connecting hole, and the second eccentric part is provided with a second connecting hole. The rotating center hole and the center locking piece passing through the rotating center hole constitute the rotating part, the first connecting hole, the first locking piece passing through the presser foot lifting rod and the first connecting hole constitute the first eccentric part, and the second connecting hole, the bearing and the second locking piece passing through the bearing and the second connecting hole constitute the second eccentric part.

[0014] In a possible implementation manner, the angle between the first crank rod and the second crank rod is greater than 90 degrees.

[0015] In a possible implementation manner, the first locking member and the central locking member are distributed on the outside of the presser foot lifter crank, and the second locking member is distributed on the inside of the presser foot lifter crank.

[0016] In one possible implementation,

[0017] The cam includes a rotating portion provided at the center and a flange portion provided on the outer edge surface of the rotating portion;

[0018] The flange portion is provided with an initial contour surface, an outwardly convex pushing contour surface and an outwardly convex retaining contour surface. The initial contour surface is set at the initial action position with the bearing. The pushing contour surface is used to accelerate the outward pushing of the bearing so that the presser foot assembly is lifted and pressed to the maximum height. The retaining contour surface is used to achieve the maintenance of the maximum lifting height. The initial contour surface, the pushing contour surface and the retaining contour surface are smoothly connected in sequence.

[0019] In a possible implementation, the presser foot lifting rod includes an upper vertical rod, a lower vertical rod and a connecting rod;

[0020] The upper end portion of the upper vertical rod is rotatably connected to the connecting end of the presser foot lifting connecting rod of the transmission assembly, the lower vertical rod is arranged on the lower outer side of the upper vertical rod, and the lower end portion of the lower vertical rod is rotatably connected to the first eccentric portion of the crank assembly, and the connecting rod obliquely connects the upper vertical rod and the lower vertical rod to avoid the rotating presser foot lifting crank.

[0021] In a possible implementation, the driving device includes a driving motor, which is fixed to a housing of the sewing machine, and the cam is fixedly mounted on a motor shaft of the driving motor.

[0022] In a second aspect, an embodiment of the present application provides a presser foot lifting mechanism, comprising:

[0023] Presser foot assembly;

[0024] a presser foot lift height adjustment mechanism connected to the presser foot assembly and used to control the presser foot lift height of the presser foot assembly, wherein the presser foot lift height adjustment mechanism is any one of the presser foot lift height adjustment mechanisms described above;

[0025] The clamping mechanism is used to press down the transmission assembly in the presser foot height adjustment mechanism so that the presser foot assembly is always in contact with the working surface of the needle plate.

[0026] In a third aspect, an embodiment of the present application provides a sewing machine, comprising a housing and a needle plate mounted on the housing, and further comprising:

[0027] A presser foot lifting mechanism, wherein the presser foot lifting mechanism is the presser foot lifting mechanism described above;

[0028] The electric control system is communicatively connected to the presser foot lifting mechanism and is used to control the presser foot lifting action of the presser foot lifting mechanism.

[0029] The presser foot lift height adjustment mechanism, presser foot lift mechanism and sewing machine provided in the embodiment of the present application replace the traditional height adjustment scheme of a stepping motor combined with a sliding drive structure, and adopt a crank lever adjustment scheme, which can significantly reduce the driving energy consumption of the driving device and achieve the technical effect of energy saving and efficiency improvement.

[0030] Specifically, the present application adopts a driving scheme combining a crank lever assembly and a driving device, utilizing the driving device to provide a rotational driving force to a cam in the crank lever assembly. During the rotation of the cam, the second eccentric portion of the crank assembly is acted on, thereby driving the second eccentric portion to rotate around its rotating portion. During the rotation of the crank assembly, its rotational force arm continues to increase, and thus the crank assembly continuously amplifies the output torque of the driving device, thereby increasing the torque of the presser foot lifter crank driving the presser foot lifter pull rod. Therefore, under the same presser foot pressure, a less powerful driving device can be used, thereby reducing the energy consumption of the driving device, reducing costs, and achieving the technical effect of energy saving and efficiency improvement. In addition, the crank lever assembly in the present application avoids the traditional complex sliding linkage action structure, has a simpler structure, a compact layout, and adopts a transmission scheme, which is more stable, efficient, and low-noise, thereby improving the efficiency of the presser foot lifter and further reducing costs.

[0031] Due to the above-mentioned presser foot lifting height adjustment mechanism, the presser foot lifting movement of the presser foot lifting mechanism is stable and efficient.

[0032] In addition, the sewing machine provided by the present application includes the above-mentioned presser foot lifting mechanism, which has low energy consumption, stable performance and low noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0034] Figure 1 A schematic diagram of the structure of the sewing machine provided in this application;

[0035] Figure 2 A structural schematic diagram of the sewing machine provided in this application from another perspective;

[0036] Figure 3 for Figure 1 The main view;

[0037] Figure 4 An exploded view of the presser foot lifting mechanism provided in this application;

[0038] Figure 5 This is a schematic diagram of the crank lever assembly in the presser foot lift height adjustment mechanism provided in this application in the initial position;

[0039] Figure 6 This is a schematic diagram of the crank lever assembly in the presser foot lift height adjustment mechanism provided in this application being in the end position;

[0040] Figure 7 An enlarged view of the crank lever in the presser foot lift height adjustment mechanism provided in this application;

[0041] Figure 8 for Figure 5 and Figure 6 Schematic diagram of the presser foot lift stroke angle and the presser foot lift maximum height holding angle shown in FIG.

[0042] Description of main component symbols.

[0043] 1- presser foot lifting mechanism, 2- housing, 3- electronic control system, 4- needle plate;

[0044] 10-presser foot height adjustment mechanism, 20-presser foot assembly, 30-pressing mechanism;

[0045] 11-transmission assembly, 12-driving device, 13-crank lever assembly;

[0046] 111-presser foot shaft, 112-presser foot sleeve, 113-reset spring, 114-presser foot connecting rod, 115-locking crank, 116-presser foot arm, 131-cam, 132-crank assembly, 133-presser foot lifting rod, 301-presser rod sleeve, 302-pressure adjusting screw assembly, 303-presser foot spring, 304-presser foot rod, 305-presser foot rod top block;

[0047] 1141-presser foot connecting rod stopper, 1151-locking crank stopper, 1311-rotating part, 1312-flange part, 1313-initial contour surface, 1314-pushing contour surface, 1315-maintaining contour surface, 1321-presser foot lifting crank, 1322-bearing, 1323-first locking member, 1324-center locking member, 1325-second locking member, 1326-rotating part, 1327-first eccentric part, 1328-second eccentric part, 1329-first crank rod, 1330-second crank rod, 1331-upper vertical rod, 1332-connecting rod, 1333-lower vertical rod.

[0048] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0049] It should be noted that when a component is referred to as being "fixed to" or "fixed to" or "set on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right", "front", "rear" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0051] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first feature is directly in contact with the second feature, or that the first feature and the second feature are indirectly in contact through an intermediary. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower horizontal height than the second feature.

[0052] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the relevant listed items.

[0053] At present, there are three main types of presser foot lifting mechanisms on the market: the first is an electromagnet automatic presser foot lifting mechanism, the second is a cylinder-driven presser foot lifting mechanism, and the third is a stepper motor-driven presser foot lifting mechanism.

[0054] The first and second presser foot lift mechanisms mentioned above use mechanical stroke control via an electromagnet and a pneumatic cylinder, respectively. Consequently, they can only reach a fixed height, resulting in poor adjustability. The third presser foot lift mechanism, driven by a stepper motor, can adjust the presser foot height, but due to the sliding drive scheme between the driven components, the adjustment structure is complex and requires multiple linkages. Consequently, the stepper motor consumes a lot of energy, suffers from significant energy losses, and is therefore expensive.

[0055] To this end, the present application provides a presser foot lift height adjustment mechanism, which improves the utilization efficiency of the motor output torque as the presser foot height increases by optimizing the cam working trajectory and coordinating the presser foot lift crank.

[0056] The crank lever assembly in the present application is based on the lever balance principle. The rotating portion at the center of its movement is rotatably connected to an external device. The first eccentric portion on one side of the rotating portion is rotatably connected to the presser foot lifter lever, and the second eccentric portion on the other side of the rotating portion is rotatably connected to the cam. The crank lever assembly moves according to a set lever ratio, thereby driving the presser foot lifter lever to rotate under the rotational force of the driving device. The presser foot lifter lever drives the transmission assembly to rotate and then drives the presser foot assembly to perform the presser foot lifting and pressing action. During the operation of the cam-driven crank assembly, the crank assembly's lever arm gradually increases, causing the crank assembly to drive the presser foot lifter lever to move up and down, thereby pulling or pushing the transmission assembly to rotate, and the transmission assembly drives the presser foot assembly to perform the presser foot lifting action.

[0057] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0058] The present application provides a presser foot lift height adjustment mechanism 10, which is used in a sewing machine to control the presser foot lift height of the presser foot assembly 20 of the sewing machine. The mechanism mainly includes a transmission assembly 11, a drive device 12, and a crank lever assembly 13. The transmission assembly 11 is connected to the presser foot assembly 20, the crank lever assembly 13 is connected to the transmission assembly 11, and the drive device 12 is connected to the crank lever assembly 13. The drive device 12 provides a bidirectional rotational driving force to the crank lever assembly 13, so that the crank lever assembly 13 drives the transmission assembly 11 to rotate, and the transmission assembly 11 in turn drives the presser foot assembly 20 to lift and press.

[0059] Specifically, the crank lever assembly 13 includes: a cam 131, a crank assembly 132 and a presser foot lifting rod 133. The cam 131 is fixed to the driving end of the driving device 12, and the two can be connected by a locking member such as a screw. The crank assembly 132 is fixed to an external device with its rotating portion 1326, such as Figure 1The crank assembly 132 is shown as being fixedly mounted on the front cover of the drive device 12 via a locking member. However, it can also be mounted on other structures, and this document does not limit this. The crank assembly 132 is rotatably connected to the presser foot lifter 133 via a first eccentric portion located on one side of the rotating portion 1326. The crank assembly 132 is also connected to the cam 131 via a second eccentric portion located on the other side of the rotating portion 1326. It should be noted that both the first and second eccentric portions herein rotate about the axis of the rotating portion 1326, achieving balanced motion according to a preset lever ratio.

[0060] The cam 131 under rotational motion acts on the second eccentric part of the crank assembly 132. The lever arm of the crank assembly 132 gradually increases during the rotation. Since the torque applied by the driving device 12 remains unchanged, the torque of the crank assembly 132 gradually increases. The crank assembly 132 drives the presser foot lifting rod 133 to rotate during the rotation, thereby amplifying the driving torque acting on the presser foot lifting rod 133. The presser foot lifting rod 133 drives the transmission assembly 11 to rotate and then drives the presser foot assembly 20 to perform the lifting and pressing action.

[0061] The crank lever assembly 13 in this application can amplify the output torque of the driving device 12 by designing the crank lever assembly 13, and optimize the driving curve of the cam 131, such as Figure 5 and Figure 6 As shown, since the torque arm is always maintained on the circumference D during the automatic presser foot lifting process, the torsion force remains unchanged when the output torque of the driving device 12 is the same. However, due to the rotation of the crank assembly 132, the value of the force arm of the crank assembly 132 will gradually increase, so that the force of the crank assembly 132 driving the presser foot lifting rod 133 gradually increases, thereby increasing the force of the crank assembly 132 driving the presser foot lifting rod 133. Therefore, a stepper motor with lower power can be used under the same presser foot pressure, which can reduce the energy consumption of the driving device 12. In addition, since the present application adopts the crank lever assembly 13, compared with the complex transmission structure on the market, its structure is simple, the movement is smooth, and low noise or even no noise can be achieved.

[0062] The distance between the center of the second eccentric portion and the center of the rotating portion 1326 is greater than the distance between the center of the first eccentric portion and the center of the rotating portion 1326. The lengths of the two can be set according to a certain ratio to improve transmission efficiency and achieve efficient transmission.

[0063] Optionally, the cam 131 includes a centrally located rotating portion 1311 and a flange portion 1312 disposed on the outer edge of the rotating portion. The flange portion 1312 can be integrally formed or connected separately, preferably integrally formed to ensure strength. The rotating portion 1311 is a cylindrical structure that can rotate about its rotation center. The flange portion 1312 is provided with an initial contour surface 1313, a pushing contour surface 1314, and a retaining contour surface 1315. The initial contour surface 1313, the pushing contour surface 1314, and the retaining contour surface 1315 are smoothly connected in sequence.

[0064] The initial contour surface 1313 can be Figure 6 The concave profile surface shown in the figure can also be a convex profile surface or a plane, ensuring that the adjacent rotating parts 1311 are smoothly connected to the pushing profile surface 1314 of the cam 131. The pushing profile surface 1314 is convex and can push the cam 131 to rotate to a preset angle. Through the transmission of the cam 131, the crank assembly 132, the presser foot lifting rod 133 and the transmission assembly 11, the presser foot assembly 20 is finally lifted and pressed to the maximum height. The maintaining profile surface 1315 is also convex and acts on the cam 131. The cam 131, the crank assembly 132, the presser foot lifting rod 133 and the transmission assembly 11 are sequentially transmitted to maintain the maximum lifting height.

[0065] In other words, the initial contour surface 1313 is set at the initial action position corresponding to the bearing 1322. During the rotation of the cam 131, the contour surface 1314 can accelerate the outward push of the bearing 1322, thereby lifting and pressing the presser foot assembly 20 to the maximum height. The maintaining contour surface 1315 is used to achieve the maintenance of the maximum lifting height.

[0066] Combine Figure 8 It can be seen that within the angle range a in the figure, as the lifting and pressing angle changes, the lifting and pressing height of the presser foot assembly 20 gradually changes. For example, as the lifting and pressing angle increases, the lifting and pressing height gradually increases, and the lifting and pressing height is positively correlated with the lifting and pressing angle. For example, when the lifting and pressing angle is 0°, the corresponding lifting and pressing height is 0mm, when the lifting and pressing angle is 50°, the corresponding lifting and pressing height is 5mm, and when the lifting and pressing angle is 65°, the lifting and pressing height is 8mm. When the presser foot lifting stroke angle reaches the maximum angle a, the presser foot reaches the maximum height, and then the maximum height is maintained within the angle b range.

[0067] It should be noted that the specific values ​​of the lifting and pressing angle and lifting and pressing height can be set according to actual needs.

[0068] In a preferred embodiment, the presser foot lifting rod 133 includes an upper vertical rod 1331, a connecting rod 1332 and a lower vertical rod 1333, wherein the upper vertical rod 1331 is generally vertically distributed, the lower vertical rod 1333 is arranged on the lower outer side of the upper vertical rod 1331 and is generally vertically distributed, and a connecting rod 1332 is connected between the upper vertical rod 1331 and the lower vertical rod 1333, and the connecting rod 1332 is obliquely connected to the upper and lower vertical rods 1333 to avoid the rotating crank assembly 132.

[0069] The upper end of the upper vertical rod 1331 is rotatably connected to the connecting end of the presser foot lifting link 114 of the transmission assembly 11, and the lower end of the lower vertical rod 1333 is rotatably connected to the first eccentric portion of the crank assembly 132. The rotational connection described herein can be, but is not limited to, a shaft connection, a bolt, a nut connection, etc.

[0070] The presser foot lifting rod 133 pulls or pushes the rotation of the presser foot lifting connecting rod 114 in the transmission assembly 11 during rotation, thereby driving the presser foot assembly 20 to lift and press. The presser foot lifting rod 133 has high movement efficiency, simple structure, convenient processing and low cost.

[0071] Preferably, the crank assembly 132 includes a presser foot lift crank 1321, a bearing 1322, a first locking member 1323, a center locking member 1324, and a second locking member 1325. The presser foot lift crank includes the above-mentioned rotating portion 1326, a first crank rod 1329, a first eccentric portion 1327, a second crank rod 1330, and a second eccentric portion 1328. The rotating portion 1326 rotates around its central axis, and the rotating portion 1326 radially extends horizontally to form the first crank rod 1329. The first eccentric portion 1327 is provided at one end of the first crank rod 1329 away from the rotating portion 1326. The second crank rod 1330 is formed by radially extending upward from the rotating portion 1326, and the second eccentric portion 1328 is provided at one end of the second crank rod 1330 away from the rotating portion 1326. Figure 7 .

[0072] The center of the rotating portion of the presser foot lifter crank 1321 is provided with a rotating center hole. A first connecting hole is provided on one side of the rotating center hole, corresponding to the center of the first eccentric portion. A second connecting hole is provided on the other side of the rotating center hole, corresponding to the center of the second eccentric portion 1328. The axes of the three holes are parallel. The center locking member 1324 passes through the rotating center hole of the presser foot lifter crank 1321 and is locked to an external device, thereby forming the aforementioned rotating portion 1326. The first locking member 1323 passes through the presser foot lifter rod 133 and the first connecting hole and is locked, forming the aforementioned first eccentric portion 1327. The second locking member 1325 passes through the bearing 1322 and the second connecting hole and is locked, forming the aforementioned second eccentric portion 1328.

[0073] like Figure 4As shown, the center locking member 1324 passes through the rotation center hole of the rotating part and is locked on the front cover of the driving device 12. Like this, the cam 131 drives the presser foot lifting crank 1321 to rotate around the central axis during rotation, thereby driving the presser foot lifting rod 133 to move with a set lever ratio.

[0074] Specifically, if Figure 4 As shown. The rotating center hole of the presser foot lift crank 1321 is fixed to the front cover of the drive device 12 by an axial screw and a gasket, and the other end is connected to the presser foot lift connecting rod 114 by an axial screw, a gasket and a nut, and the third end is connected to the gasket and the bearing 1322 by an axial screw and a nut. The first locking member 1323 composed of the axial screw, the gasket and the nut and the center locking member 1324 composed of the axial screw and the gasket are distributed on the outside of the presser foot lift crank 1321 (that is, the side away from the drive device 12), and the second locking member 1325 composed of the axial screw and the nut is distributed on the inside of the presser foot lift crank 1321 (that is, the side close to the drive device 12). This can reduce the occupied space and make the installation structure more compact.

[0075] The presser foot lift crank 1321 is generally L-shaped, and the angle between the first crank rod 1329 and the second crank rod 1330 is greater than 90 degrees to provide greater rotational torque and improve rotational efficiency. It should be noted that the angle between the first crank rod 1329 and the second crank rod 1330 can be, but is not limited to, an obtuse angle, and can also be, for example, a right angle or an acute angle.

[0076] The driving device 12 includes a driving motor, such as Figure 1 and Figure 3 As shown, the driving motor is fixedly mounted on the housing 2 of the sewing machine by screws etc. A cam 131 is fixedly mounted on the motor shaft of the driving motor. The cam 131 can be fixed on the motor shaft by screws or indirectly mounted on the motor shaft by components such as adapters.

[0077] The crank lever assembly 13 and the driving device 12 are coaxially arranged, which has high transmission efficiency and saves installation space.

[0078] The driving motor in the present application can be but is not limited to a stepper motor. Through the cooperation of the cam 131 and the presser foot lifting crank 1321, as the presser foot height increases, the utilization efficiency of the motor output torque increases. Therefore, under the same presser foot pressure, a smaller power motor can be used to meet the requirements, thereby reducing the motor power requirements and reducing energy consumption.

[0079] refer to Figure 4The transmission assembly 11 mainly includes: a presser foot shaft 111, a presser foot sleeve 112, a return spring 113, a presser foot connecting rod 114, a locking crank 115 and a presser foot arm 116. The presser foot sleeve 112 is installed inside the presser foot sleeve 112, and the presser foot sleeve 112 is installed on the housing 2. The return spring 113 is sleeved on the presser foot sleeve 112. The presser foot lifting connecting rod 114 is sleeved on the presser foot sleeve 112 and is axially fixed by the locking crank 115 and the presser foot sleeve 112. It can rotate radially along the presser foot sleeve 112. The locking crank 115 is locked to the presser foot shaft 111 by a screw and rotates as the presser foot shaft 111 rotates. At the same time, the locking crank stopper 1151 cooperates with the presser foot lifting connecting rod stopper 1141 in a certain rotation direction. When rotating in the opposite direction of the rotation direction, the locking crank stopper 1151 moves away from the presser foot lifting connecting rod stopper 1141.

[0080] When the motor shaft rotates, it drives the cam 131, the presser foot lifting crank 1321, the presser foot lifting rod 133, the presser foot lifting connecting rod 114, the locking crank 115, the presser foot shaft 111 and the presser foot arm 116 to rotate, driving the presser foot assembly 20 to rotate around the axis of the presser foot shaft 111, thereby performing the up and down lifting and pressing actions.

[0081] For example, when the presser foot lifting rod 133 moves downward, it drives the locking crank 115 to rotate counterclockwise, and the locking crank 115 drives the presser foot shaft 111 to rotate counterclockwise, drives the presser foot arm 116 to rotate counterclockwise, and lifts the presser foot assembly 20. Conversely, the presser foot assembly 20 is pressed down.

[0082] In addition, the present application also provides a presser foot lifting mechanism 1, which mainly includes a presser foot assembly 20, a presser foot lifting height adjustment mechanism 10 and a clamping mechanism 30, wherein the presser foot lifting height adjustment mechanism 10 is connected to the presser foot assembly 20 and is used to control the lifting and pressing height of the presser foot assembly 20. The presser foot lifting height adjustment mechanism 10 is specifically the presser foot lifting height adjustment mechanism 10 mentioned above, and the specific structure can be seen above. Its implementation principle and technical effect are similar, and this embodiment will not be repeated here.

[0083] The clamping mechanism 30 is used to press the presser foot assembly 20 downward, ensuring that it remains in contact with the working surface of the needle plate 4. Specifically, the clamping mechanism 30 comprises a pressure rod sleeve 301, a pressure-adjusting screw assembly 302, a pressure-foot spring 303, and a pressure-foot rod 304. The pressure-foot sleeve 301 is secured to the housing 2 with screws, and the pressure-adjusting screw assembly 302 is threadedly connected to the pressure-foot sleeve 301. One end of the pressure-foot spring 303 rests on the adjustment screw assembly, while the other end rests on the pressure-foot rod 304 assembly. The pressure-foot rod 304 assembly is connected to the presser foot arm 116 via a pressure-foot rod support block 305. The elastic force of the pressure-foot spring 303 ensures that the presser foot assembly 20 remains facing downward, in contact with the needle plate 4.

[0084] Since the presser foot lifting height adjusting mechanism 10 is provided, the presser foot lifting mechanism 1 has at least the same technical effect as the presser foot lifting height adjusting mechanism 10 .

[0085] In addition, the present application also provides a sewing machine, such as Figures 1 to 3 As shown, it mainly includes a housing 2 and a needle plate 4 installed on the housing 2, and also includes: a presser foot lifting mechanism 1 and an electronic control system 3. Among them, the presser foot lifting mechanism 1 is arranged above the needle plate 4. The presser foot lifting mechanism 1 is specifically the presser foot lifting mechanism 1 mentioned above, which will not be repeated here.

[0086] The electronic control system 3 is communicatively connected to the presser foot lifting mechanism 1 and is used to control the presser foot lifting action of the presser foot lifting mechanism 1. The drive device 12 is connected to the electronic control system 3 via wires to transmit signals, and the drive device 12 operates according to the signal instructions of the electronic control system 3. Specifically, a transmitting sensor is provided on the housing 2, and a receiving sensor is provided on the needle plate 4. The number of receiving sensors can be one, two, or more. The transmitting sensor and the receiving sensor are both connected to the electronic control system 3 via wires to achieve signal transmission. By receiving the sensor signal timing, the electronic control system 3 drives the motor shaft to rotate counterclockwise, driving the cam 131. The cam 131 drives the bearing 1322, which in turn drives the presser foot lifting crank 1321 to move counterclockwise. The presser foot lifting crank 1321 drives the presser foot lifting rod 133, and the presser foot lifting rod 133 then drives the presser foot lifting connecting rod 114 to rotate, ultimately achieving presser foot lifting.

[0087] The sewing machine provided by the present application has smooth movement, low energy consumption, and low noise.

[0088] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. It is not limited to the precise structure described above and illustrated in the drawings, and various modifications and variations may be made without departing from the scope of the invention. The scope of the invention is limited solely by the appended claims.

Claims

1. A presser foot height adjustment mechanism, characterized in that: include: a driving device for drivably connecting to the crank lever assembly and providing a rotational driving force to the crank lever assembly; a crank lever assembly connected to the drive device for transmitting the rotational driving force to the transmission assembly; A transmission assembly, fixedly connected to the presser foot assembly and transmission-connected to the crank lever assembly, the transmission assembly being used to connect to the presser foot assembly, and the transmission assembly being configured to drive the presser foot assembly to perform a presser foot lifting action under the action of a rotational driving force; The crank lever assembly includes: a cam, a crank assembly and a presser foot lifting connecting rod, the cam is fixedly arranged on the driving end of the driving device, the crank assembly is fixedly connected to an external device through a rotating part, and the first eccentric part and the second eccentric part on the crank assembly located on both sides of the rotating part are respectively rotatably connected to the presser foot lifting rod and the cam are transmission-connected, the cam under the rotating motion acts on the second eccentric part so that the crank assembly amplifies the driving torque acting on the presser foot lifting rod during rotation, and the presser foot lifting rod drives the transmission assembly to rotate and then drives the presser foot assembly to perform the lifting and pressing action.

2. The presser foot lift height adjustment mechanism according to claim 1, characterized in that: A distance between a center of the second eccentric portion and a center of the rotating portion is greater than a distance between a center of the first eccentric portion and a center of the rotating portion.

3. The presser foot lift height adjustment mechanism according to claim 1 or 2, characterized in that: The crank assembly includes a presser foot lift crank, a bearing, a first locking member, a center locking member and a second locking member; The presser foot lifting crank comprises the rotating portion, a first crank rod radially extending horizontally from the rotating portion, the first eccentric portion provided at an end portion of the first crank rod, a second crank rod radially extending upward from the rotating portion, and a second eccentric portion provided at an end portion of the second crank rod; The rotating part is provided with a rotating center hole, the first eccentric part is provided with a first connecting hole, and the second eccentric part is provided with a second connecting hole. The rotating center hole and the center locking piece passing through the rotating center hole constitute the rotating part, the first connecting hole, the first locking piece passing through the presser foot lifting rod and the first connecting hole constitute the first eccentric part, and the second connecting hole, the bearing and the second locking piece passing through the bearing and the second connecting hole constitute the second eccentric part.

4. The presser foot lift height adjustment mechanism according to claim 3, characterized in that: An included angle between the first crank rod and the second crank rod is greater than 90 degrees.

5. The presser foot lift height adjustment mechanism according to claim 4, characterized in that: The first locking piece and the central locking piece are distributed on the outside of the presser foot lifting crank, and the second locking piece is distributed on the inside of the presser foot lifting crank.

6. The presser foot lift height adjustment mechanism according to claim 3, characterized in that: The cam includes a rotating portion provided at the center and a flange portion provided on the outer edge surface of the rotating portion; The flange portion is provided with an initial contour surface, an outwardly convex pushing contour surface and an outwardly convex retaining contour surface. The initial contour surface is set at the initial action position with the bearing. The pushing contour surface is used to accelerate the outward pushing of the bearing so that the presser foot assembly is lifted and pressed to the maximum height. The retaining contour surface is used to achieve the maintenance of the maximum lifting height. The initial contour surface, the pushing contour surface and the retaining contour surface are smoothly connected in sequence.

7. The presser foot lift height adjustment mechanism according to claim 3, characterized in that: The presser foot lifting rod comprises an upper vertical rod, a lower vertical rod and a connecting rod; The upper end portion of the upper vertical rod is rotatably connected to the connecting end of the presser foot lifting connecting rod of the transmission assembly, the lower vertical rod is arranged on the lower outer side of the upper vertical rod, and the lower end portion of the lower vertical rod is rotatably connected to the first eccentric portion of the crank assembly, and the connecting rod obliquely connects the upper vertical rod and the lower vertical rod to avoid the rotating presser foot lifting crank.

8. The presser foot lift height adjustment mechanism according to claim 1, characterized in that: The driving device includes a driving motor, which is fixed on the housing of the sewing machine. The cam is fixedly sleeved on the motor shaft of the driving motor.

9. A presser foot lifting mechanism, characterized in that: include: Presser foot assembly; a presser foot lift height adjustment mechanism connected to the presser foot assembly and used to control the presser foot lift height of the presser foot assembly, wherein the presser foot lift height adjustment mechanism is the presser foot lift height adjustment mechanism according to any one of claims 1 to 8; The clamping mechanism is used to press down the transmission assembly in the presser foot height adjustment mechanism so that the presser foot assembly is always in contact with the working surface of the needle plate.

10. A sewing machine, characterized in that: The invention comprises a housing and a needle plate mounted on the housing, and further comprises: A presser foot lifting mechanism, wherein the presser foot lifting mechanism is the presser foot lifting mechanism according to claim 9; The electric control system is communicatively connected to the presser foot lifting mechanism and is used to control the presser foot lifting action of the presser foot lifting mechanism.

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