Sewing machine, needle bar crank of sewing machine and design method of needle bar crank
By adjusting the center-of-gravity parameters of the needle bar crank in dynamic simulation software, the vibration and noise problems of the sewing machine needle bar crank were solved, realizing a high-efficiency and low-cost design for the sewing machine and improving motion accuracy and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-19
- Publication Date
- 2026-04-14
AI Technical Summary
The sewing machine needle crank generates a large periodic inertial force during high-speed operation, which causes machine vibration and noise, and reduces motion accuracy and stability.
By building a dynamic model of the needle crank in dynamic simulation software, adjusting the parameters of the simulated center of mass, calculating the inertial force, and selecting the parameter conditions that meet the set conditions, the needle crank is designed.
Quickly design the optimal needle bar crank to reduce vibration and noise, improve the motion accuracy and smoothness of the sewing machine, simplify the design process and reduce costs.
Smart Images
Figure CN121859460A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of sewing machine technology, and in particular to a sewing machine, a sewing machine needle crank, and a design method thereof. Background Technology
[0002] A sewing machine is a machine that uses one or more sewing threads to create one or more stitches on fabric, allowing one or more layers of fabric to interweave or sew together. The needle bar crank mechanism is one of the core transmission mechanisms of a sewing machine. Its core function is to convert the rotary motion output by the motor (spindle rotation) into the reciprocating linear motion of the needle bar, and, in conjunction with other mechanisms (such as the shuttle and feed mechanism), to achieve thread piercing, thread guide, and stitch formation. It is the key actuator for the sewing machine to complete the sewing action.
[0003] During the high-speed operation of the needle bar crank mechanism in a sewing machine, a large periodic inertial force is generated, which in turn causes strong vibration and noise in the machine, exacerbates fatigue failure and wear of machine parts, and reduces the motion accuracy and stability of the needle bar crank mechanism. Therefore, how to design the needle bar crank to balance the periodic inertial force of the needle bar crank and thus improve the vibration and noise of the sewing machine is an urgent problem to be solved. Summary of the Invention
[0004] This application provides a sewing machine, a needle bar crank for the sewing machine, and a design method thereof, which improves the vibration and noise of the sewing machine.
[0005] In a first aspect, embodiments of this application provide a method for designing the needle bar crank of a sewing machine, including: A dynamic model of the needle crank was built in a dynamic simulation software, and the simulated center of mass of the needle crank was established. Multiple sets of parameter scenarios are set, and the simulated center of mass is adjusted in the dynamic simulation software according to the multiple sets of parameter scenarios. The inertial force of the pin crank on the front bearing housing under different parameter scenarios is calculated. The parameter scenarios include the size parameters, position parameters, and mass parameters of the simulated center of mass. Select the inertial force that meets the set conditions from the inertial force of the needle bar crank on the front bearing housing under different parameter conditions, and design the needle bar crank according to the parameter conditions corresponding to the inertial force.
[0006] Furthermore, the step of building a dynamic model of the needle crank in the dynamic simulation software and establishing the simulated center of mass of the needle crank includes: Build a dynamic model of the needle crank in dynamic simulation software, and create a solid on the needle crank; The solid density of the needle bar crank is set within a set range, and the mass of the solid is set to be consistent with the mass of the needle bar crank. The entity is used as a simulated center of mass of the needle crank.
[0007] Furthermore, the construction of the dynamic model of the needle crank in the dynamic simulation software includes: In the dynamic simulation software, start the motion example analysis mode, establish the kinematic pair of the needle bar crank, and complete the modeling of the needle bar crank.
[0008] Furthermore, the setting of multiple sets of parameters involves adjusting the simulated center of mass in the dynamic simulation software using these multiple sets of parameters, and calculating the inertial force of the needle crank on the front bearing housing under different parameter conditions, including: Multiple sets of parameter scenarios are set, and the dynamic simulation software uses each of the multiple sets of parameter scenarios as input parameters to obtain multiple sets of output results corresponding to the multiple sets of parameter scenarios. The output results include the inertial force of the needle crank on the front bearing housing.
[0009] Furthermore, the inertial force of the needle bar crank on the front bearing housing includes the Y-axis inertial force and the Z-axis inertial force.
[0010] Furthermore, the setting conditions include: the difference between the Y-direction inertial force and the Z-direction inertial force of the needle bar crank on the front bearing housing is minimized.
[0011] Furthermore, the selection of the inertial force satisfying the set conditions from the inertial forces of the needle bar crank on the front bearing housing under different parameter conditions includes: A graph is created to represent the Y-axis and Z-axis inertial forces of the needle bar crank on the front bearing housing under different parameter conditions. The horizontal axis of the graph represents the sequence number of each parameter condition, and the vertical axis represents the Y-axis and Z-axis inertial forces determined according to each parameter condition. Connect the inertial forces in the Y direction on the graph to form the first curve, and connect the inertial forces in the Z direction to form the second curve; Select the intersection point of the first curve and the second curve, and take the Y-direction inertial force and Z-direction inertial force corresponding to the intersection point as the inertial force that satisfies the set conditions.
[0012] Furthermore, the design of the needle crank based on the parameters corresponding to the inertial force includes: In the parameter cases corresponding to the Y-direction inertial force and Z-direction inertial force that meet the set conditions, the size parameters, position parameters and mass parameters of the simulated centroid are used as the centroid parameters that distinguish the needle bar. The needle crank is designed based on the stated center of mass parameters.
[0013] Secondly, embodiments of this application provide a needle bar crank for a sewing machine, wherein the needle bar crank is prepared using the design method described in the first aspect.
[0014] Thirdly, embodiments of this application provide a sewing machine including the needle bar crank as described in the second aspect.
[0015] By using the above technical solution, the parameters of the center of mass of the needle bar crank are simulated and adjusted using dynamic simulation software. The parameter conditions that make the inertial force of the needle bar crank mechanism meet the set conditions are selected. Based on these parameter conditions, the optimal needle bar crank can be designed quickly, thereby reducing and improving the vibration and noise of the sewing machine during operation, and improving the motion accuracy and stability of the sewing machine.
[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description
[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0018] Figure 1 The diagram shown is a partial structural schematic of a sewing machine according to an exemplary embodiment of this application.
[0019] Figure 2 The diagram shown is a flowchart illustrating the needle crank design method of an exemplary embodiment of this application.
[0020] Figure 3 The diagram shown is a modeling schematic of the needle crank of a sewing machine according to an exemplary embodiment of this application.
[0021] Figure 4 The diagram shown is a flowchart illustrating a needle crank design method according to another exemplary embodiment of this application.
[0022] Figure 5 The diagram shown is a flowchart illustrating a needle crank design method according to another exemplary embodiment of this application.
[0023] Figure 6 The diagram shown illustrates the selection of parameters for a needle crank design method according to another exemplary embodiment of this application. Detailed Implementation
[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0025] This application provides a sewing machine, a needle bar crank for the sewing machine, and a design method thereof. The sewing machine, the needle bar crank for the sewing machine, and the design method thereof are described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementations can be combined with each other.
[0026] See Figure 1 As shown, a sewing machine typically includes a main shaft 40, a needle bar 30, a needle bar crank 10, and a front bearing housing 20. The needle bar crank 10 is connected to the main shaft 40 via the front bearing housing 20, and the needle bar 30 is connected to the needle bar crank 10 via a connecting rod 50. The main shaft 40 can be connected to a drive motor, which drives the main shaft 40 to rotate, causing the needle bar crank 10 to rotate as well. The needle bar crank 10, through the connecting rod 50, drives the needle bar 30 to reciprocate linearly up and down. It can be understood that the needle bar crank converts the rotational motion output by the motor (main shaft rotation) into the reciprocating linear motion of the needle bar.
[0027] During the high-speed operation of the needle bar crank mechanism in a sewing machine, a large periodic inertial force is generated, leading to strong vibration and noise in the machine, accelerating fatigue failure and wear of machine parts, and reducing the motion accuracy and stability of the needle bar crank mechanism. The inertial force can be balanced by adjusting the mass and center of gravity position of the needle bar crank. Traditional methods, such as manually adjusting the shape of the needle bar crank, are inefficient and rarely yield optimal results. Alternatively, methods using co-simulation design with software like ISight and Hyperworks are complex, require high skill levels, and are expensive.
[0028] See Figure 2 As shown, this application embodiment provides a design method for the needle bar crank of a sewing machine, including steps S1-S3: Step S1: Build a dynamic model of the needle crank 10 in the dynamic simulation software and establish the simulated center of mass of the needle crank 10. For example... Figure 3 As shown, the actual center of mass of the needle crank 10 is point A, the simulated center of mass is point B, and the geometric center is point O.
[0029] Step S2: Set multiple sets of parameter scenarios, adjust the simulated center of mass in the dynamic simulation software according to the multiple sets of parameter scenarios, and calculate the inertial force of the pin crank 10 on the front bearing seat 20 under different parameter scenarios. The parameter scenarios include the size parameters, position parameters, and mass parameters of the simulated center of mass.
[0030] Step S3: Select an inertial force that meets the set conditions from the inertial forces of the needle bar crank 10 on the front bearing seat 20 under different parameter conditions, and design the needle bar crank 10 according to the parameter conditions corresponding to the inertial force. It can be understood that the smaller the inertial force of the needle bar crank 10 on the front bearing seat 20, the smaller the vibration generated.
[0031] Through the above technical solution, the parameters of the center of mass of the needle bar crank 10 are simulated and adjusted by dynamic simulation software. The parameter conditions that make the inertial force of the needle bar crank 10 mechanism meet the set conditions are selected. Based on these parameter conditions, the optimal needle bar crank 10 can be designed quickly, thereby reducing and improving the vibration and noise of the sewing machine during operation, and improving the motion accuracy and stability of the sewing machine.
[0032] See Figure 4 As shown, in some optional embodiments, step S1, which involves building a dynamic model of the needle crank 10 in the dynamic simulation software and establishing the simulated center of mass of the needle crank 10, includes steps S11-S13: Step S11: Build a dynamic model of the needle crank 10 in the dynamic simulation software, and create a solid on the needle crank 10. In this embodiment, SolidWorks can be used as the dynamic simulation software. The dynamic model of the sewing machine's needle crank can be built in SolidWorks Motion. Alternatively, the dynamic module of other dynamic simulation software can be used, as long as it can model the needle crank.
[0033] Step S12: Set the solid density of the needle crank 10 to a set range, and set the mass of the solid to be consistent with the mass of the needle crank 10. In this embodiment, the solid density of the needle crank is set to be extremely small to facilitate the simulation of the center of mass position.
[0034] Step S13: Use the solid entity as the simulated center of mass of the needle crank 10. Optionally, the solid entity can be a cylindrical solid to simulate the actual center of mass of the needle crank, or a solid entity of other shapes can be used to simulate the actual center of mass of the needle crank, as long as it can simulate the actual center of mass of the needle crank.
[0035] It should be noted that, taking a cylindrical solid as an example, the dimensional parameter in the aforementioned parameter case can be the radius, and the positional parameter can be an angular parameter, such as... Figure 2 The angle α shown in the figure is the angle between the line connecting the actual centroid A and the geometric center O of the needle crank and the line connecting the simulated centroid B and the geometric center O.
[0036] In some optional implementations, step S1, which involves building a dynamic model of the needle crank 10 in the dynamic simulation software, may include: starting the motion simulation analysis mode in the dynamic simulation software, establishing the kinematic pair of the needle crank 10, that is, setting the front bearing seat 20, the main shaft 40 and the drive motor on the needle crank 10, and completing the modeling of the needle crank 10.
[0037] In some optional implementations, step S2, setting multiple sets of parameter scenarios and adjusting the simulated center of mass in the dynamic simulation software using these multiple sets of parameter scenarios to calculate the inertial force of the needle crank 10 on the front bearing housing 20 under different parameter scenarios, may include: setting multiple sets of parameter scenarios, using each of these multiple sets of parameter scenarios as input parameters in the dynamic simulation software, and obtaining multiple sets of output results corresponding to the multiple sets of parameter scenarios. The output results include the inertial force of the needle crank 10 on the front bearing housing 20. Optionally, each output result can be saved as a CSV file. It is understood that the smaller the inertial force of the needle crank 10 on the front bearing housing 20, the smaller the vibration generated.
[0038] Optionally, such as Figure 1 As shown, the inertial force of the needle crank 10 on the front bearing housing 20 includes the Y-axis inertial force and the Z-axis inertial force. Taking SolidWorks as the dynamic simulation software, the input parameters for each parameter case can be entered into SolidWorks Motion, and then the inertial force of the needle crank 10 on the front bearing housing 20, including the Y-axis inertial force and the Z-axis inertial force, can be calculated separately under different parameter cases.
[0039] The set conditions may include minimizing the difference between the Y-axis and Z-axis inertial forces of the needle bar crank 10 on the front bearing housing 20. This ensures a more balanced force between the needle bar crank 10 and the front bearing housing 20 in both directions, resulting in less vibration.
[0040] See Figure 5 As shown, in some optional embodiments, step S3, which involves selecting the inertial force that satisfies the set conditions from the inertial forces of the needle crank 10 on the front bearing housing 20 under different parameter conditions, includes steps S31-S33: Step S31, as follows Figure 6 As shown, a graph is created to represent the Y-axis inertial force and Z-axis inertial force of the needle crank 10 to the front bearing housing 20 under different parameter conditions. The horizontal axis of the graph represents the sequence number of each parameter condition, and the vertical axis represents the Y-axis inertial force and Z-axis inertial force determined according to each parameter condition.
[0041] Step S32: Connect the Y-axis inertial forces on the graph to form the first curve, and connect the Z-axis inertial forces to form the second curve, as shown below. Figure 6 As shown, the first curve formed by the connection of each Y-direction inertial force is the blue curve, and the second curve formed by the connection of each Z-direction inertial force is the orange curve.
[0042] Step S33: Select the intersection point of the first curve and the second curve, and take the Y-direction inertial force and Z-direction inertial force corresponding to the intersection point as the inertial force that satisfies the set conditions, that is, the Y-direction inertial force and Z-direction inertial force corresponding to parameter case 4.
[0043] Understandably, by using charting methods to select from multiple parameter scenarios involving Y-axis and Z-axis inertial forces, the optimal needle bar crank center of mass position and mass can be found where both Y-axis and Z-axis inertial forces are relatively balanced (the intersection of X-axis and Y-axis inertial forces in the figure). Thus, by calculating the inertial forces of the needle bar crank, the optimal center of mass position and mass of the needle bar crank under the condition of minimum inertial force can be found, thereby improving the vibration and noise of the sewing machine.
[0044] In some optional embodiments, step S3, designing the needle crank 10 according to the parameter cases corresponding to the inertial force, includes: using the size parameters, position parameters, and mass parameters of the simulated center of mass in the parameter cases corresponding to the Y-axis and Z-axis inertial forces that satisfy the set conditions as the center of mass parameters that distinguish the needle crank. The needle crank 10 is then designed based on these center of mass parameters. That is, by designing the external dimensions of the needle crank according to the optimal size parameters, position parameters, and mass parameters of the center of mass obtained through the above steps, the optimal needle crank can be obtained.
[0045] The following section uses SolidWorks as an example to describe in detail the design method of the needle crank of the sewing machine in this application.
[0046] First, a dynamic model of the sewing machine's needle crank is built in Solidworks Motion to establish the kinematic pair of the needle crank.
[0047] Then, an additional cylindrical solid is created on the needle bar crank. The density of the needle bar crank solid is set to be extremely small, and the mass of the cylindrical solid is set to be the same as the mass of the needle bar crank. In this way, the cylindrical solid can be used to replace the actual center of mass of the needle bar crank.
[0048] Then, using the design example function of SolidWorks Motion, multiple sets of parameter scenarios are set, that is, the size parameters, position parameters, and mass parameters of the cylindrical solid are set. In this way, a series of positions (i.e., simulated centroid positions) and masses of the cylindrical solid can be simulated.
[0049] Using multiple sets of parameter scenarios as input parameters for the needle bar crank, the Y-axis and Z-axis inertial forces of the needle bar crank on the front bearing housing under different parameter scenarios are calculated in Solid Works Motion (motion simulation module), as shown in Table 1 below.
[0050] Table 1 Combination Figure 6 As shown, the Y-axis and Z-axis inertial forces of the obtained multiple cases are selected. The case where the Y-axis and Z-axis inertial forces are relatively balanced is the optimal position and mass of the needle bar crank. In this embodiment, the case corresponding to the intersection of the X-axis and Y-axis inertial forces is used as the optimal parameter, which can make the force of the needle bar crank on the front bearing seat more balanced in both directions and generate less vibration.
[0051] Finally, by designing the external dimensions of the needle crank based on the selected optimal parameters of the centroid and mass, the optimal needle crank can be obtained.
[0052] Compared to traditional methods that involve manually adjusting the shape of the needle bar and crank, which are inefficient and difficult to achieve optimal results, or methods that use iSight+Hyperworks for co-simulation design, which are complex to operate, require high skill levels, and are expensive due to the high cost of the software, this approach offers a more efficient and cost-effective solution.
[0053] This application uses SolidWorks as the dynamic simulation software to simulate and adjust the parameters of the center of mass of the needle bar crank, selecting the parameter conditions that allow the inertial force of the needle bar crank mechanism to meet the set conditions. Based on these parameter conditions, the optimal needle bar crank can be designed quickly, thereby reducing and improving the vibration and noise during sewing machine operation, and improving the motion accuracy and stability of the sewing machine. Compared with traditional methods, this simplifies the design process of the needle bar crank, allowing the optimal needle bar crank to be designed using a single software, resulting in high efficiency and low cost.
[0054] This application also provides a needle bar crank for a sewing machine, which is manufactured using the design method described above. By simulating and adjusting the parameters of the center of mass of the needle bar crank using dynamic simulation software, the parameter conditions that allow the inertial force of the needle bar crank mechanism to meet the set conditions are selected. Based on these parameter conditions, an optimal needle bar crank can be quickly designed, thereby reducing and improving the vibration and noise during the operation of the sewing machine, and improving the motion accuracy and stability of the sewing machine.
[0055] This application provides a sewing machine including a needle bar crank prepared using the above-described design method. By simulating and adjusting the parameters of the center of mass of the needle bar crank using dynamic simulation software, the parameter conditions that allow the inertial force of the needle bar crank mechanism to meet the set conditions are selected. Based on these parameter conditions, an optimal needle bar crank can be quickly designed, thereby reducing and improving the vibration and noise of the sewing machine during operation, and improving the motion accuracy and stability of the sewing machine.
[0056] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.
Claims
1. A design method for the needle bar crank of a sewing machine, characterized in that, include: A dynamic model of the needle crank was built in the dynamic simulation software, and the simulated center of mass of the needle crank was established. Multiple sets of parameter scenarios are set, and the simulated center of mass is adjusted in the dynamic simulation software according to the multiple sets of parameter scenarios. The inertial force of the pin crank on the front bearing housing under different parameter scenarios is calculated. The parameter scenarios include the size parameters, position parameters, and mass parameters of the simulated center of mass. Select the inertial force that meets the set conditions from the inertial force of the needle bar crank on the front bearing housing under different parameter conditions, and design the needle bar crank according to the parameter conditions corresponding to the inertial force.
2. The design method for the needle bar crank of a sewing machine according to claim 1, characterized in that, The process of building a dynamic model of the needle crank in dynamic simulation software and establishing the simulated center of mass of the needle crank includes: Build a dynamic model of the needle crank in dynamic simulation software, and create a solid on the needle crank; The solid density of the needle bar crank is set within a set range, and the mass of the solid is set to be consistent with the mass of the needle bar crank. The entity is used as a simulated center of mass of the needle crank.
3. The design method for the needle bar crank of a sewing machine according to claim 1 or 2, characterized in that, The process of building a dynamic model of the needle crank in dynamic simulation software includes: In the dynamic simulation software, start the motion example analysis mode, establish the kinematic pair of the needle bar crank, and complete the modeling of the needle bar crank.
4. The design method of the needle bar crank of the sewing machine according to claim 1, characterized in that, The process involves setting multiple sets of parameters, adjusting the simulated center of mass in the dynamic simulation software according to these multiple sets of parameters, and calculating the inertial force of the needle crank on the front bearing housing under different parameter conditions, including: Multiple sets of parameter scenarios are set, and the dynamic simulation software uses each of the multiple sets of parameter scenarios as input parameters to obtain multiple sets of output results corresponding to the multiple sets of parameter scenarios. The output results include the inertial force of the needle crank on the front bearing housing.
5. The design method for the needle bar crank of a sewing machine according to claim 1 or 4, characterized in that, The inertial force of the needle bar crank on the front bearing housing includes the Y-axis inertial force and the Z-axis inertial force.
6. The design method for the needle bar crank of a sewing machine according to claim 5, characterized in that, The set conditions include: the difference between the Y-axis inertial force and the Z-axis inertial force of the needle bar crank on the front bearing housing is minimized.
7. The design method for the needle bar crank of a sewing machine according to claim 6, characterized in that, The selection of the inertial force that meets the set conditions from the inertial forces of the needle bar crank on the front bearing housing under different parameter conditions includes: A graph is created to represent the Y-axis and Z-axis inertial forces of the needle bar crank on the front bearing housing under different parameter conditions. The horizontal axis of the graph represents the sequence number of each parameter condition, and the vertical axis represents the Y-axis and Z-axis inertial forces determined according to each parameter condition. Connect the inertial forces in the Y direction on the graph to form the first curve, and connect the inertial forces in the Z direction to form the second curve; Select the intersection point of the first curve and the second curve, and take the Y-direction inertial force and Z-direction inertial force corresponding to the intersection point as the inertial force that satisfies the set conditions.
8. The design method for the needle bar crank of a sewing machine according to claim 7, characterized in that, The design of the needle crank based on the parameters corresponding to the inertial force includes: In the parameter cases corresponding to the Y-direction inertial force and Z-direction inertial force that meet the set conditions, the size parameters, position parameters and mass parameters of the simulated centroid are used as the centroid parameters that distinguish the needle bar. The needle crank is designed based on the stated center of mass parameters.
9. A needle bar crank for a sewing machine, characterized in that, The needle crank is prepared using the design method described in any one of claims 1-8.
10. A sewing machine, characterized in that, Includes the needle crank as described in claim 9.