Cam drive for a presser foot and embroidery machine

Abstract

This application discloses a cam drive device for a presser foot and an embroidery machine, relating to the field of embroidery equipment technology, and solves the problems of complex structure and inconvenient assembly of existing cam drive devices for presser feet. The cam drive device includes a presser foot drive cam mounted on the main shaft, a first transmission component, and a second transmission component. The presser foot drive cam has an inner cam surface and an outer cam surface on its axial sides, respectively. The first transmission component has a first rotating part, a first roller, and a second rotating fulcrum, with the first rotating part rotatably engaging with the first rotating fulcrum. The second transmission component has a second rotating part and a second roller, with the second rotating part rotatably engaging with the second rotating fulcrum. The first roller and the outer cam surface roll in cooperation to lower the presser foot; the second roller and the inner cam surface roll in cooperation to raise the presser foot.

Description

Technical Field

[0001] This application belongs to the technical field of embroidery equipment, specifically relating to embroidery machines. Background Technology

[0002] In the field of embroidery machine technology, the presser foot is driven in two ways: one is combined with the needle bar movement, in which the needle bar drives the presser foot to reciprocate up and down; the other is an independent presser foot, which is driven by an independent power source to reciprocate up and down. The reciprocating up and down movements of the independent presser foot and the needle bar do not interfere with each other.

[0003] Referring to Chinese patent application CN207958712U, a presser foot cam transmission mechanism and an embroidery machine are disclosed. The presser foot cam is a single cam structure with a cam ring groove that cooperates with a bearing or roller. The stroke of the presser foot rising and falling is not precise enough. In addition, the material is nylon. Under high-speed operation, the cam wears faster and the bearing or roller that cooperates with the cam is easily damaged.

[0004] Referring to Chinese patent application CN117802708 A, an independent presser foot drive device is disclosed, including a main shaft, a first cam and a second cam disposed on the main shaft, an independent presser foot, a first transmission member having a first rotation fulcrum, and a presser foot drive block that can be raised and lowered; the first transmission member and the presser foot drive block are directly or indirectly movably connected; the first transmission member has a first roller and a second roller; the rolling engagement between the outer cam surface of the first roller and the first cam causes the presser foot drive block to drive the independent presser foot to complete the upward stroke, and the rolling engagement between the outer cam surfaces of the second roller and the second cam causes the presser foot drive block to drive the independent presser foot to complete the downward stroke. Since both the first and second cams are external cams, an elastic element is connected between the first and second transmission components to achieve rolling engagement between the first and second rollers and their external cam surfaces. During installation, the first and second transmission components can be rotated relative to each other by a certain angle, causing the elastic element to deform. After assembly, the elastic element allows the first and second transmission components to rotate relative to each other, thus causing the first and second rollers to respectively engage with the external cam surfaces of the first and second cams. However, this increases the number of components in the transmission structure and also increases assembly difficulty. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the technical problem to be solved in this application is to provide a cam drive device for a presser foot and an embroidery machine, thereby solving the problems of complex structure and inconvenient assembly of existing cam drive devices for presser feet.

[0006] To solve the above-mentioned technical problems, this application adopts the following technical solution: First, a cam drive device for a presser foot is provided for driving the presser foot to rise or fall, characterized in that the cam drive device includes a main shaft and: The pressure foot drive cam is mounted on the spindle, and the pressure foot drive cam has an inner cam surface and an outer cam surface; A first transmission component is provided with a first rotating part, a first roller, and a second rotating fulcrum, wherein the first rotating part is rotatably engaged with the fixedly provided first rotating fulcrum. The second transmission component is provided with a second rotating part and a second roller; The first roller and the outer cam surface roll into each other, causing the first transmission component to rotate around the first pivot point in the first direction, thereby driving the pressure foot to descend; The second roller and the inner cam surface roll into each other, and the second transmission component rotates with the second pivot point through the second rotating part, so that the first transmission component rotates around the first pivot point in the second direction, thereby driving the pressure foot to rise.

[0007] Preferably, the inner cam surface and the outer cam surface are respectively located on both sides of the axial direction of the presser foot drive cam; and / or, the first roller is a first bearing and the second roller is a second bearing.

[0008] Preferably, the diameter of the first bearing is larger than that of the second bearing; and / or, the first bearing and the second bearing are deep groove ball bearings.

[0009] Preferably, it further includes a third transmission component hinged to the first transmission component, the presser foot is connected to a presser foot driver, the presser foot driver is slidably mounted on a vertically arranged guide shaft, and the third transmission component is hinged to the presser foot driver so that the presser foot can be driven to rise or fall by the presser foot driver.

[0010] Preferably, the first transmission component includes a first connecting rod, a first rotating part is disposed at a first end of the first connecting rod, a second rotating fulcrum is disposed at the middle of the first connecting rod, a first roller is disposed between the first rotating part and the second rotating fulcrum, and a third rotating part is disposed at a second end of the first connecting rod, the third rotating part being hinged to the third transmission component.

[0011] Preferably, the first connecting rod has a protrusion that protrudes outward from the cam surface, and the first roller is mounted on the protrusion.

[0012] Preferably, the first rotating part is a first connecting rod bearing; and / or, the third transmission component includes a third connecting rod, with a second connecting rod bearing provided at each end of the third connecting rod.

[0013] Preferably, the first pivot point includes a first pivot pin and a pin seat, the first pivot pin is disposed on the pin seat, and the pin seat is fixed to the side wall of the machine head housing.

[0014] Preferably, the pin seat is provided with a protruding post that protrudes into the inner side of the housing, the first fulcrum pin is installed on the protruding post, and the side wall of the head housing is provided with a groove to avoid the protruding post.

[0015] In addition, this application also provides an embroidery machine, including the aforementioned cam drive device for a presser foot.

[0016] The present application adopts the above technical solution and has the following technical effects: The presser foot drive cam has an inner cam surface and an outer cam surface, and the presser foot can be driven for both the rising and falling strokes with only one cam. Because the transmission functions of the inner and outer cam surfaces are clearly defined: the outer cam surface + first roller corresponds to the presser foot falling stroke, and the inner cam surface + second roller corresponds to the presser foot rising stroke, the two core strokes of the presser foot are precisely matched one-to-one with the hyperboloid cam surface and rollers. The transmission logic is clearer, the division of labor among transmission components is more defined, and the rising / falling action of the presser foot is more direct, reducing the likelihood of stroke interference. By using the rolling contact between the first / second roller and the outer / inner cam surface, the sliding friction is converted into rolling friction, significantly reducing the wear of the cam surface and transmission components, and extending the service life of the device. Simultaneously, the precise contact between the roller and the cam surface enables precise mechanical control of the presser foot's rising / falling stroke, avoiding stroke deviation.

[0017] The intermediate transmission structure downstream of the presser foot-driven cam drive includes a first transmission component and a second transmission component. The first roller engages with the outer cam surface, driving the first transmission component to rotate in a first direction (presser foot down). The second roller engages with the inner cam surface, driving the second transmission component to rotate, and through a second pivot point, links the first transmission component to rotate in a second direction (presser foot up). Both rotations occur around the same pivot point, resulting in fewer components, a significantly reduced number of hinge points, and a simplified structure.

[0018] The design employs a single presser foot-driven cam that integrates inner and outer double cam surfaces. Compared to the traditional design with two independent cams, this simplifies assembly at the core component level. Only one cam needs to be coaxially mounted on the spindle to complete the assembly of the core transmission component. Compared to dual cams, which require separate positioning, installation, and coaxiality calibration, this reduces one cam assembly step and avoids the assembly and adjustment issues caused by axial spacing and coaxiality deviations. The inner and outer cam surfaces are integrally formed structures of the cam body, and their relative position and contour accuracy are determined during the machining stage. No additional adjustment of the mating relationship between the two working surfaces is required during assembly, eliminating the need for alignment and adjustment of the cam working surfaces. Direct clamping ensures the mating accuracy of subsequent transmission components.

[0019] These features and advantages of this application will be disclosed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description

[0020] The following description, in conjunction with the accompanying drawings, further illustrates this application: Figure 1 This is an exploded view of the head structure of the embroidery machine in this application (needle bar frame not shown). Figure 2 This is a schematic diagram of the assembly structure of the embroidery machine head in this application (needle bar frame not shown); Figure 3 This is a schematic diagram of the cam drive device of this application in the state of driving the pressure foot descending; Figure 4 This is a schematic diagram of the cam drive device of this application in the state of driving the pressure foot rising; Figure 5 This is an exploded structural diagram of the cam drive device of this application; Figure 6 This is a schematic diagram of the presser foot driven cam in this application. Figure 1 ; Figure 7 This is a schematic diagram of the presser foot driven cam in this application. Figure 2 ; Figure 8 This is a schematic diagram of the structure of the first transmission component in this application; Figure 9 This is a schematic diagram of the structure of the second transmission component in this application; Figure 10 This is a schematic diagram of the structure of the third transmission component in this application; Figure 11 This is a schematic diagram of the structure of the first rotational fulcrum; Figure 12 This is a schematic diagram of the installation structure of the first rotation fulcrum; Figure 13 This is a front view of the cam drive device of this application; Figure 14 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 1 ; Figure 15 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 2 ; Figure 16 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 1 ; Figure 17 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 2 ; Reference numerals: Cam drive device 100, first transmission component 110, first rotating part 111, first roller 112, second rotating fulcrum 113, third rotating part 114, protrusion 115, second transmission component 120, second roller 121, second rotating part 122, third transmission component 130, second connecting rod bearing 131, connecting rod pin 132, pressure foot drive cam 140, inner cam surface 141, outer cam surface 142, clamping part 143, shaft Hole 144, fixed bushing 145, fixed screw hole 1451, fixed screw 1452, locking bushing 146, expansion joint 1461, clamp 147, first rotating fulcrum 150, first fulcrum pin 151, pin seat 152, protrusion 153, fixed screw 154, presser foot driver 160, machine head housing 200, first rotating fulcrum mounting part 210, groove 211, fixed hole 212, guide shaft 220, needle bar drive device 230. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of this application and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of this application.

[0022] Those skilled in the art will understand that, without conflict, the features in the following embodiments and implementations can be combined with each other.

[0023] The terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the application. For example, terms such as "upper," "lower," "front," "rear," and "lateral," which indicate orientation or positional relationship, are based solely on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing the application and simplifying the description. They do not indicate or imply that the device / component referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the application.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0027] As shown in Figures 1 to 17, the embroidery machine has at least one machine head, which includes a machine head housing 200 and a needle bar frame located on the front side of the machine head housing 200. A transverse slide rail mechanism is provided between the needle bar frame and the machine head housing 200. When changing colors, the needle bar frame slides laterally along the transverse slide rail mechanism. In this embodiment, the relative direction between the needle bar frame and the machine head housing 200 is defined as the front-back direction, and the direction of movement of the needle bar frame is defined as the transverse direction, or the left-right direction. The embroidery machine has a main shaft that extends laterally and passes through each machine head housing 200. The main shaft serves as a power source to drive the needle bars on the needle bar frame to perform reciprocating lifting and lowering movements, so that the embroidery needles at the bottom of the needle bars can embroider on the embroidery fabric. A needle bar drive device 230 is provided between the main shaft and the needle bars, which can adopt a conventional cam linkage mechanism in the prior art. The presser foot is slidably mounted on the needle bar and connected to the presser foot driver 160, and is driven by the presser foot driver 160. A vertically mounted guide shaft 220 is provided on the head housing 200, and the presser foot driver 160 is slidably mounted on the guide shaft 220.

[0028] This embodiment uses a cam drive device 100 to drive the pressure foot to rise or fall, which includes a conventional spindle and: The presser foot drive cam 140 is mounted on the spindle. The presser foot drive cam 140 has an inner cam surface 141 and an outer cam surface 142. For example, the inner cam surface 141 and the outer cam surface 142 are located on the axial sides or radial sides of the presser foot drive cam 140, respectively, that is, the outer cam surface surrounds the radial outer side of the inner cam surface. The first transmission component 110 is provided with a first rotating part 111, a first roller 112 and a second rotating fulcrum 113, and the first rotating part 111 is rotatably engaged with the fixedly provided first rotating fulcrum 150. The second transmission member 120 is provided with a second rotating part 122 and a second roller 121, and the second rotating part 122 is rotatably engaged with the second rotating fulcrum 113. The third transmission component 130 is hinged to the first transmission component 110 and to the presser foot. The hinge to the presser foot can be either a direct hinge to the presser foot or a hinge to a component connected to the presser foot. In this configuration, the first roller 112 and the outer cam surface 142 roll into each other, causing the first transmission member 110 to rotate around the first rotation fulcrum 150 in a first direction, thereby causing the third transmission member 130 to drive the pressure foot to descend. The second roller 121 and the inner cam surface 141 roll into each other, and the second transmission member 120 rotates around the first rotation fulcrum 113 via the second rotating part 122, causing the first transmission member 110 to rotate around the first rotation fulcrum 150 in a second direction, thereby causing the third transmission member 130 to drive the pressure foot to rise. Here, the first and second directions can be considered as opposite directions; for example, if the first direction is clockwise, then the second direction is counterclockwise. Ultimately, the end of the third transmission member 130 that is relatively far from the connection to the first transmission member 110 can drive the pressure foot to rise or fall.

[0029] In this embodiment, the inner cam surface 141 and the outer cam surface 142 are respectively located on both axial sides of the presser foot drive cam. By placing the inner and outer cam surfaces on the axial sides of the presser foot drive cam, compared to placing the two cam surfaces on both radial sides, motion interference between the cam working surface and the transmission components can be avoided, resulting in a more compact structure. Simultaneously, it facilitates the synchronous driving of two sets of transmission components by a single cam, simplifying the overall structure. The axial arrangement makes the cam mass distribution more uniform, easier to achieve dynamic balance, and results in less vibration and smoother operation during high-speed rotation. Furthermore, it simplifies machining and assembly, helps ensure the relative positional accuracy between the two cam surfaces, and makes the transmission control of the presser foot's rise and fall more precise and reliable.

[0030] The third transmission component 130 can be directly connected to the presser foot driver 160. The third transmission component 130 drives the presser foot to rise or fall through the presser foot driver 160. Since the presser foot driver 160 is slidably mounted on the guide shaft 220, and the presser foot is slidably mounted on the needle bar, the lifting and lowering action of the presser foot can achieve directional and precise sliding, which is suitable for the high-speed, high-precision, and high-reliability operation requirements of embroidery machine equipment.

[0031] Alternatively, the cam drive device 100 can be located on the left side inside the head housing 200, and the needle bar drive device 230 can be located on the right side. The inner cam surface 141 and the outer cam surface 142 are respectively located on the left and right sides of the presser foot drive cam 140. The first rotating part 111 and the first roller 112 are located on the right side of the presser foot drive cam 140, while the second transmission member 120 and its second roller 121 are located on the left side of the presser foot drive cam 140, thus achieving efficient utilization of the lateral space inside the head housing 200.

[0032] like Figure 6 As shown, in one embodiment, a clamping part 143 is provided on the right side of the center of the presser foot drive cam 140, and the clamping part 143 is integrally formed with the presser foot drive cam 140. A shaft hole 144 is provided at the center of the presser foot drive cam 140, and part of the shaft hole 144 is located within the clamping part 143. The shaft hole 144 mates with the main shaft and is clamped and fixed by the clamping part 143. Figure 16 and Figure 17 As shown, in one embodiment, a fixed bushing 145 is provided on the right side of the center of the presser foot drive cam 140. The fixed bushing 145 is integrally formed with the presser foot drive cam 140, and the inner hole of the fixed bushing is part of the shaft hole. The fixed bushing 145 is provided with at least one fixing screw hole 1451, for example, two fixing screw holes 1451, and a fixing screw 1452 is connected to it. The fixing screw 1452 is locked and fixed to the spindle. Figure 16 and Figure 17 As shown, in one embodiment, a locking bushing 146 is provided on the right side of the center of the presser foot drive cam 140. The locking bushing 146 is integrally formed with the presser foot drive cam 140. The inner hole of the locking bushing is part of the shaft hole. The locking bushing has expansion joints 1461 distributed circumferentially. The outer side of the locking bushing is provided with a separate clamp 147, which locks and fixes the locking bushing 146 to the main shaft.

[0033] In this embodiment, the cam drive device 100 designates the two axial sides of the presser foot drive cam 140 as inner and outer cam surfaces, enabling the presser foot to move in both upward and downward strokes with a single cam. By clearly defining the transmission functions of the inner and outer cam surfaces—outer cam surface 142 + first roller 112 corresponding to the presser foot's downward stroke, and inner cam surface 141 + second roller 121 corresponding to the presser foot's upward stroke—the two core strokes of the presser foot are precisely matched one-to-one with the cam hyperboloid and rollers. This results in a clearer transmission logic, well-defined division of labor among the transmission components, and a more direct response to the presser foot's upward / downward movements, minimizing stroke interference. The use of the first roller 112 / second roller 121 in rolling contact with the outer and inner cam surfaces transforms sliding friction into rolling friction, significantly reducing wear on the cam surface and transmission components, and extending the device's lifespan. Simultaneously, the precise contact between the rollers and the cam surface ensures precise mechanical control of the presser foot's upward / downward strokes, preventing stroke deviations.

[0034] The intermediate transmission structure downstream of the presser foot drive cam 140 is simplified into a three-piece core structure consisting of a first transmission component 110, a second transmission component 120, and a third transmission component 130. The power transmission path is: presser foot drive cam 140 → first transmission component 110 / second transmission component 120 → third transmission component 130 → presser foot driver 160 → presser foot. The first roller 112, in conjunction with the outer cam surface 142, drives the first transmission component 110 to rotate in the first direction (presser foot down). The second roller 121, in conjunction with the inner cam surface 141, drives the second transmission component 120 to rotate, and through the second rotation fulcrum 113, the first transmission component 110 rotates in the second direction (presser foot up). Both rotations occur around the same fulcrum, and the third transmission component drives the presser foot's lifting and lowering motion, achieving directional and offset-free control of the presser foot's lifting and lowering motion. Due to the fewer components, the number of hinge points is significantly reduced. Power is directly transmitted from the cam to the presser foot driver 160 via the three-stage transmission components, reducing power loss caused by multiple hinge points and improving overall transmission efficiency. A single presser foot drive cam 140 is adopted, and inner and outer double cam surfaces are integrated on both sides of its axis, replacing the design of two independent cams in the traditional technology, thus simplifying assembly from the core component level.

[0035] The assembly of the core transmission component can be completed by simply installing one cam coaxially onto the spindle. Compared with double cams, which require separate positioning, installation, and coaxiality calibration, this reduces one cam assembly process and avoids the assembly and adjustment caused by axial spacing and coaxiality deviations of double cams. The inner and outer cam surfaces are integrally formed structures of the cam body, and their relative position and contour accuracy are determined during the machining stage. There is no need to adjust the fit relationship between the two working surfaces during assembly. There is no need for the alignment and adjustment of the cam working surfaces. Direct clamping can ensure the fit accuracy of subsequent transmission components. Furthermore, the connections between the first transmission component 110 and the first rotating fulcrum 150, between the first transmission component 110, the second transmission component 120, and the third transmission component 130, and between the third transmission component 130 and the pressure foot driver 160, are all rotatable. A fully articulated connection design can be adopted, allowing for simple split-type connection operations and detachable assembly processes. This makes assembly operations faster and process connections more flexible, while improving the assembly qualification rate. Standardized articulated pairs enhance component interchangeability, and point-type connections are suitable for confined assembly spaces. This meets the assembly needs of industrial mass production while also ensuring ease of assembly for later maintenance. Therefore, assembly is convenient, and after assembly, only a simple trial run is required to ensure the accuracy of the pressure foot lifting stroke, eliminating the need for lengthy trial runs, adjustments, and calibrations, significantly shortening the cycle from assembly to finished product.

[0036] like Figure 6 and Figure 7As shown, to design the inner cam surface 141 and the outer cam surface 142, the presser foot drive cam 140 has an inner cam groove and an outer cam boss on its axial sides, respectively. The inner cam surface 141 is a curved working surface formed by the inner wall of the inner cam groove in the presser foot drive cam 140, which mates with the second roller 121. This inner wall is the core transmission surface of the inner cam groove, and its curved profile is designed according to the stroke law of the presser foot's lifting and lowering. Through rolling contact with the second roller 121, it transmits the power of the cam rotation to drive the presser foot to complete the corresponding stroke action. The outer cam surface 142 is a curved working surface formed by the outer wall of the outer cam boss in the presser foot drive cam 140, which mates with the first roller 112. This outer wall is the core transmission surface of the boss, and its curved profile is also designed according to the stroke requirements of the presser foot's lifting and lowering. It forms a conjugate fit with the inner cam surface 141, and through rolling contact with the first roller 112, it collaboratively achieves the complete power transmission for the presser foot's lifting and lowering. The inner cam surface 141 and the outer cam surface 142 are two conjugate curved working surfaces on the presser foot drive cam 140. The inner cam surface is responsible for driving the presser foot upwards, while the outer cam surface is responsible for driving the presser foot downwards. They are matched, connected, and do not conflict with each other in terms of timing, stroke, and speed, together forming a complete, continuous, and coordinated lifting and lowering cycle of the presser foot. The inner cam surface 141 and the outer cam surface 142 are formed based on the inner cam groove and outer cam boss structure of the cam, respectively. Through precise cooperation with different transmission components, they drive the presser foot to complete different strokes of upward and downward movement, jointly achieving continuous and precise control of the presser foot lifting and lowering action. It can be understood that the inner cam surface 141 and the outer cam surface 142 can also both be formed from the inner wall of the cam groove.

[0037] The first roller 112 and the second roller 121 can be elastic rollers, such as rollers with an outer ring made of elastic polyurethane material. In some embodiments, the first roller 112 is a first bearing and the second roller 121 is a second bearing. Preferably, the first and second bearings are deep groove ball bearings, but other bearings can also be used. Bearings are industrial standard parts, and their dimensional accuracy and rotational coaxiality are much higher than those of customized roller structures. By setting the first and second rollers as bearings, the contact gap between the first bearing and the outer cam surface 142, and between the second bearing and the inner cam surface 141, is more uniform, ensuring precise synchronization between the presser foot's downward / upward stroke and the cam rotation, thus improving the precision of the embroidery process. Since bearings are general-purpose standardized industrial parts, their procurement cost is much lower than that of customized rollers. Moreover, during later maintenance, if the bearings are worn or malfunction, they can be directly disassembled and replaced with standard bearings of the same model, making maintenance more convenient and significantly reducing operating costs.

[0038] Because the first bearing is less constrained by space, its diameter is larger than that of the second bearing. The presser foot descent is the core working stroke of the embroidery operation. During descent, it directly presses against the embroidery fabric, overcoming the elastic resistance of the fabric and the preload of the presser foot spring. Simultaneously, it drives the presser foot driver 160 to descend synchronously. The radial pressure and friction of the outer cam surface 142 on the first bearing are much greater than those during the upward stroke. The larger diameter first bearing offers several advantages: firstly, it provides a larger contact area, dispersing the contact stress between the cam surface and the bearing, preventing cam surface crushing and bearing outer ring wear caused by localized stress concentration; secondly, it enhances the bearing's radial load-bearing capacity, adapting to the large load of the descent stroke and preventing bearing failures such as rolling element breakage and inner ring deformation due to overload; thirdly, the rotational inertia of the larger diameter bearing is better suited to the rapid movement requirements of the presser foot descent, ensuring precise synchronization with the cam rotation and preventing problems such as jamming during the descent stroke and insufficient fabric pressing. Of course, depending on the needs, the diameter of the first bearing can also be smaller than or equal to that of the second bearing.

[0039] In some embodiments, the pressure foot drive cam 140 is provided with weight reduction holes. It is understood that the weight reduction holes follow the design principle of "opening holes in non-stressed areas and retaining them in the core stress areas." The connection between the cam and the spindle, and the force transmission areas of the inner / outer cam surfaces, maintain a complete solid structure. Weight reduction holes are only opened on the end face of the cam and in non-fitting edge areas. For example, they can extend through both axial sides of the pressure foot drive cam 140, with partial openings on the outer cam boss, and at a considerable distance from the outer cam surface 142. Providing weight reduction holes can reduce the rotational inertia of the cam, improve the motion response speed and stability of the pressure foot drive, and also reduce the power load on the spindle and drive motor, achieving energy saving and consumption reduction.

[0040] like Figure 8As shown, the first transmission member 110 includes a first connecting rod, and a first rotating part 111 is disposed at the first end of the first connecting rod. The first rotating part 111 can be a first connecting rod bearing and is connected to a first fulcrum pin 151 on the first rotating fulcrum 150. The second rotating fulcrum 113 is disposed in the middle of the first connecting rod and is provided with a pin. The first roller 112 is disposed between the first rotating part 111 and the second rotating fulcrum 113. The second end of the first connecting rod is provided with a third rotating part 114, which is hinged to the third transmission member 130. The second transmission member 120 is disposed on the left side of the first transmission member 110, the second rotating fulcrum 113 is correspondingly disposed on the left side of the first transmission member 110, and the third transmission member 130 is disposed on the right side of the first transmission member 110. The segmented layout of the first rotating part 111, the second rotating fulcrum 113, the first roller 112, and the third rotating part 114 located at the first end, middle, both sides of the middle section, and the second end of the connecting rod is to achieve cooperation with the first rotating fulcrum 150, the second transmission component 120, the pressure foot drive cam 140, and the third transmission component 130.

[0041] Furthermore, the first connecting rod is provided with a protrusion 115 protruding outward from the cam surface 142. The first roller 112 is mounted on the protrusion 115. In the lateral projection of the first transmission member 110, the centers of the first rotating part 111, the second rotating fulcrum 113, and the third rotating part 114 are on the same straight line, while the first roller 112 deviates outward from this straight line, so that a certain gap space is formed between the main body of the first transmission member 110 and the outer cam surface 142. The outer cam surface 142 is formed by the outer wall of the cam boss. The boss is a structure in which the cam body protrudes outward. The first roller 112 needs to actively conform to the cam boss to achieve rolling contact with the outer cam surface 142. Therefore, the protrusion 115 protruding outward from the cam surface 142 is provided on the first connecting rod to allow the first roller 112 to have the space to conform to the outer cam surface 142, avoiding obstruction by the connecting rod body or interference with the boss structure, and ensuring a gapless fit between the roller and the outer cam surface 142.

[0042] In order to match the design of the first link, such as Figure 9 As shown, the second transmission component 120 includes a second connecting rod, a second roller 121 at the first end, and a second rotating part 122 at the second end. The second rotating part 122 can be a clamp-type pin hole, connected to a pin on the second rotating fulcrum 113. Figure 10As shown, the third transmission component 130 includes a third connecting rod, with a second connecting rod bearing 131 at each end of the third connecting rod, which is hinged to the first transmission component 110 and the pressure foot driver 160, respectively. The second connecting rod bearing 131 includes an integrally formed connecting rod pin 132 as the bearing inner ring, thus eliminating the need for a separate bearing inner ring. Correspondingly, the third rotating part 114 and the pressure foot driver 160 can be provided with clamp-type pin holes to hinge with the connecting rod pin 132 of the second connecting rod bearing 131.

[0043] The three-piece core structure of the aforementioned first transmission component 110, second transmission component 120, and third transmission component 130 adopts a conventional linkage mechanism, which is combined through hinges, simplifying the structure and facilitating assembly. The design of the first and second connecting rod bearings 131 ensures transmission accuracy. Moreover, due to rolling friction, the coefficient of friction (typically 0.01~0.05) is much lower than that of sliding friction (typically 0.1~0.3), directly reducing frictional resistance at the source, reducing wear on metal surfaces, lowering the wear rate of components, and extending service life.

[0044] like Figure 11 and Figure 12 As shown, in some embodiments, the first pivot point 150 includes a first pivot pin 151 and a pin seat 152, the first pivot pin 151 is disposed on the pin seat 152, and the pin seat 152 is fixed to the side wall of the head housing 200.

[0045] Specifically, taking the cam drive device 100 located on the left side of the head housing 200 as an example, the pin seat 152 is fixed to the left side wall of the head housing 200. The pin seat 152 has a protruding post 153 protruding towards the inside of the housing. The first fulcrum pin 151 is installed on the protruding post 153, that is, the protruding post 153 protrudes to the right, and the first fulcrum pin 151 extends to the right. The protruding post 153 is cylindrical, and it has a flat structure facing the pressure foot drive cam, which can form a clearance space to avoid the pressure foot drive cam in a limited space. The side wall of the head housing 200 is provided with a first rotating fulcrum mounting part 210, including a groove 211 for avoiding the protruding post 153 and a fixing hole 212. The pin seat 152 is connected to the fixing hole 212 by a fixing screw 154, thereby fixing the pin seat 152 to the side wall of the head housing 200. The internal space of the machine head is extremely valuable. Fixing the pin seat 152 to the side wall of the machine head housing 200 makes full use of the side wall space, eliminating the need to reserve additional installation space for the rotation fulcrum inside the machine head housing 200, thus maximizing the utilization rate of the internal space of the machine head housing 200. The design of the protrusion 153 is to place the first fulcrum pin 151 on the right side of the pressure foot drive cam 140, so as to cooperate with the first rotating part 111. The protrusion 153 is a precisely oriented protrusion structure. Its protrusion height and radial dimension are shaped according to the internal space of the machine head, and it only extends the necessary length at the required position, avoiding excessive protrusion of the protrusion 153 that would occupy space.

[0046] The above description is merely a specific embodiment of the application, but the scope of protection of the application is not limited thereto. Those skilled in the art should understand that this application includes, but is not limited to, the content described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the application will be included within the scope of the claims.

Claims

1. A cam driving device of a presser foot for driving the presser foot to be raised or lowered, characterized by, The cam drive device includes a main shaft and: The pressure foot drive cam is mounted on the spindle, and the pressure foot drive cam has an inner cam surface and an outer cam surface; A first transmission component is provided with a first rotating part, a first roller, and a second rotating fulcrum, wherein the first rotating part is rotatably engaged with the fixedly provided first rotating fulcrum. The second transmission component is provided with a second rotating part and a second roller; The first roller and the outer cam surface roll into each other, causing the first transmission component to rotate around the first pivot point in the first direction, thereby driving the pressure foot to descend; The second roller and the inner cam surface roll into each other, and the second transmission component rotates with the second pivot point through the second rotating part, so that the first transmission component rotates around the first pivot point in the second direction, thereby driving the pressure foot to rise.

2. The cam drive device for a presser foot according to claim 1, characterized in that, The inner cam surface and the outer cam surface are respectively located on both sides of the axial direction of the presser foot drive cam; and / or, the first roller is a first bearing and the second roller is a second bearing.

3. The cam drive device for a presser foot according to claim 2, characterized in that, The diameter of the first bearing is larger than that of the second bearing; and / or, the first bearing and the second bearing are deep groove ball bearings.

4. The cam drive device for a presser foot according to claim 1, characterized in that, It also includes a third transmission component hinged to the first transmission component. The presser foot is connected to a presser foot driver. The presser foot driver is slidably mounted on a vertically arranged guide shaft. The third transmission component is hinged to the presser foot driver so that the presser foot can be driven to rise or fall by the presser foot driver.

5. The cam drive device for a presser foot according to claim 4, characterized in that, The first transmission component includes a first connecting rod, a first rotating part is disposed at the first end of the first connecting rod, a second rotating fulcrum is disposed at the middle of the first connecting rod, a first roller is disposed between the first rotating part and the second rotating fulcrum, and a third rotating part is disposed at the second end of the first connecting rod, the third rotating part being hinged to the third transmission component.

6. The cam drive device for a presser foot according to claim 5, characterized in that, The first connecting rod has a protrusion that protrudes outward from the cam surface, and the first roller is mounted on the protrusion.

7. The cam drive device for a presser foot according to claim 4, characterized in that, The first rotating part is a first connecting rod bearing; and / or, the third transmission component includes a third connecting rod, and a second connecting rod bearing is provided at each end of the third connecting rod, which is respectively hinged to the first transmission component and the pressure foot driver.

8. The cam drive device for a presser foot according to claim 1, characterized in that, The first pivot point includes a first pivot pin and a pin seat. The first pivot pin is disposed on the pin seat, and the pin seat is fixed to the side wall of the machine head housing.

9. A cam drive device for a presser foot according to claim 8, characterized in that, The pin seat is provided with a protruding post that protrudes into the inner side of the housing. The first fulcrum pin is installed on the protruding post. The side wall of the head housing is provided with a groove to avoid the protruding post.

10. An embroidery machine, characterized in that, The invention includes a cam drive device for a presser foot as described in any one of claims 1 to 9.

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