Four-bar mechanism design method and system based on multiple heald frames

Abstract

The invention provides a four-bar mechanism design method and system based on multiple heald frames, and relates to the technical field of four-bar transmission mechanisms, and the method comprises the following steps: determining design requirements of a heald frame four-bar mechanism based on opening process requirements; designing a crank rotation center of the heald frame four-bar mechanism; performing normalization modeling on the heald frame four-bar mechanism in combination with a crank rotation center; determining the optimal ratio of the length of the rack to the length of the crank, and calculating rod piece parameters of the heald frame four-rod mechanism; establishing a rectangular plane coordinate system according to the rod piece parameters; in the rectangular plane coordinate system, determining a crank rotation center position of the heald frame four-bar mechanism and a rocker swing angle arc midpoint position; fitting a lifting heald arm adjusting arc, and calculating an error swing angle of the fitted arc; and constraining the heald frame four-bar mechanism according to the bar parameters, the rotation center position of the crank, the swing angle arc midpoint position of the rocker and the error swing angle so as to complete the design of the heald frame four-bar mechanism. According to the invention, high-precision opening adjustment is realized, and the manufacturing cost of the shedding blade is reduced.

Description

Technical Field

[0001] This invention relates to the field of four-bar linkage technology, and in particular to a design method and system for a four-bar linkage based on a multi-piece heddle frame. Background Technology

[0002] The main function of electronic multi-arm shedding mechanisms in the textile process is to drive the heald frames up and down, so that the warp yarns passing through the heald frames form a clear shed, which is then used in conjunction with weft insertion and beat-up mechanisms to complete the weaving of the fabric. With the gradual development of servo motors, electronic multi-arm shedding mechanisms, where each heald frame is driven by an individual servo motor, are becoming increasingly widely used in the textile industry because the motor motion pattern of each heald frame can be designed to set the vertical rest angle of the heald frames to meet the needs of different fabrics.

[0003] For independently driven electronic multi-arm opening mechanisms, in order to unify the design of the lifting blades used for different heald frames and reduce manufacturing costs, the design of the lifting arms in the lifting blades corresponding to different heald frames should be the same. Since the dimensions of the four-bar linkages of different heald frames are different, it is necessary to design the four-bar linkage of each heald frame in order to ensure that multiple heald frames sharing the same lifting arm can meet the opening process requirements before and after the opening amount adjustment.

[0004] However, in existing multi-heal frame designs, the poor coordination of movement between heald frames and the unreasonable arrangement of crank rotation centers cause interference and conflict between the rods of different heald frames, thus affecting the accuracy of heald frame opening adjustment and the uniformity of yarn tension. Inconsistent up-and-down strokes may occur during heald frame opening adjustment, resulting in unstable opening size and movement of the heald frame at different opening amounts, affecting yarn tension and fabric quality during weaving. For multiple heald frames sharing the same heald lifting arm, existing designs often cannot ensure that the midpoint of the heald lifting arm swing angle arc of each heald frame is on the same arc line during opening adjustment, which may lead to errors during adjustment and thus affect the opening accuracy of each heald frame. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a four-bar linkage design method based on multi-heal frames. This method can solve the problems in existing multi-heal frame designs, such as poor motion coordination between heald frames, unreasonable arrangement of crank rotation centers, mutual interference and conflict between the links of different heald frames, which affects the accuracy of heald shedding adjustment and the uniformity of yarn tension. Inconsistent up and down strokes may occur during heald shedding adjustment, resulting in unstable heald shedding size and movement at different shedding amounts, affecting yarn tension and fabric quality during weaving. For multiple heald frames sharing the same heald lifting arm, existing designs often cannot ensure that the midpoint of the heald lifting arm swing angle arc of each heald frame is on the same arc line during heald shedding adjustment, which may lead to errors during adjustment and thus affect the accuracy of the heald shedding of each heald frame.

[0006] A first aspect of this invention proposes a design method for a four-bar linkage based on a multi-piece heald frame, comprising:

[0007] S1: Based on the requirements of the opening process, the design requirements of the heald frame four-bar linkage are determined, wherein the heald frame four-bar linkage includes: crank, rocker, connecting rod and frame;

[0008] S2: Based on the design requirements, using a four-bar linkage design method with known crank length and rocker swing angle, the crank rotation center of the heald frame four-bar linkage is designed.

[0009] S3: Based on the crank rotation center, perform normalized modeling of the heald frame four-bar linkage to determine the mathematical model of the heald frame four-bar linkage;

[0010] S4: Based on the mathematical model, analyze the optimal ratio between the frame length and the crank length, and calculate the link parameters of the heald frame four-bar linkage according to the optimal ratio;

[0011] S5: Based on the link parameters, establish a Cartesian coordinate system for the four-bar linkage of the helical frame;

[0012] S6: In the plane rectangular coordinate system, determine the position of the crank rotation center and the position of the midpoint of the rocker arm swing angle arc of the four-bar linkage;

[0013] S7: Based on the position of the crank rotation center and the position of the midpoint of the rocker arm swing arc, fit the adjustment arc of the heddle arm and calculate the error swing angle of the fitted arc;

[0014] S8: Based on the link parameters, the crank rotation center position, the midpoint position of the rocker arm swing arc, and the error swing angle, constrain the heald frame four-bar linkage to complete the design of the heald frame four-bar linkage.

[0015] A second aspect of the present invention provides a four-bar linkage design system based on a multi-chip truss frame, comprising: a processor and a memory;

[0016] The memory stores programs or instructions that can run on the processor, which, when executed by the processor, implement the steps of the four-bar linkage design method based on a multi-piece heald frame as described in the first aspect.

[0017] In a fourth aspect of the present invention, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the four-bar linkage design method based on a multi-piece heald frame as described in the first aspect.

[0018] The beneficial effects of the technical solutions provided by the embodiments of the present invention include at least the following:

[0019] In this embodiment of the invention, by designing the crank rotation center of the four-bar linkage without quick-return characteristics, it is ensured that the rocker's motion does not undergo abrupt changes or instability, achieving a smooth adjustment effect. This avoids conflicts caused by mutual interference between links and ensures that multiple heald frames operate in a coordinated manner within the same system. A normalized model of the four-bar linkage is established based on the crank rotation center, clarifying the relationship between the rocker length and the crank angle. This ensures that the rocker does not exhibit quick-return characteristics during the adjustment of the opening amount, guaranteeing smooth motion of each heald frame under different opening amounts. By determining the optimal ratio between the frame length and the crank length and calculating the link parameters, the motion of the four-bar linkage becomes more precise. To ensure that the opening amount of each heald frame is consistent and accurate under different opening amounts, a Cartesian coordinate system is established, and the position of the crank rotation center is determined in this coordinate system. This further optimizes the accuracy and consistency of the opening amount adjustment. By determining the position of the crank rotation center and the position of the midpoint of the rocker arm swing angle arc, it is ensured that the midpoint of the heald lifting arm swing angle arc of each heald frame is located on the same arc line, avoiding the inconsistency problem in the existing design. By fitting the rocker arm swing angle arc, an arc line with small error is obtained as the adjustment arc of the heald lifting arm, making the adjustment arc of each heald frame accurate and consistent, thereby achieving high-precision opening amount adjustment and reducing the manufacturing cost of the heald lifting blade. Attached Figure Description

[0020] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0021] Figure 1This is a flowchart illustrating a design method for a four-bar linkage based on a multi-piece heald frame provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of a 3D model of the electronic opening mechanism provided in an embodiment of the present invention;

[0023] Figure 3 This is a simplified diagram of a single-piece heald frame structure provided in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the adjustment arc of the lifting arm provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the distribution of the midpoint of the swing angle arc provided in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the crank angle with two openings in the heald frame provided in an embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of a four-bar linkage design provided in an embodiment of the present invention;

[0028] Figure 8 This is a schematic diagram showing the relationship between the opening amount of the heald frame and the swing angle of the heald lifting arm provided in an embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram of the crank angle model provided in an embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram illustrating the calculation of the crank rotation center and the midpoint of the swing angle arc provided in an embodiment of the present invention;

[0031] Figure 11 This is a diagram showing the variation of the extreme position angle and crank angle provided in an embodiment of the present invention;

[0032] Figure 12 This is a schematic diagram showing the position of the rotation center of the heddle frame crank and the midpoint of the swing angle arc provided in an embodiment of the present invention;

[0033] Figure 13 This is a schematic diagram of the adjustment arc error swing angle provided in an embodiment of the present invention;

[0034] Figure 14 This is a schematic diagram of a four-bar linkage design system based on a multi-piece heald frame provided in an embodiment of the present invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0036] The following description, in conjunction with the accompanying drawings, details the design method of a four-bar linkage based on a multi-piece heald frame provided by the present invention through specific embodiments and application scenarios.

[0037] Reference manual attached Figure 1 The diagram shows a flowchart of a four-bar linkage design method based on a multi-piece heald frame provided by an embodiment of the present invention.

[0038] Reference manual attached Figure 2 The diagram shows a 3D model of the electronic opening mechanism provided in an embodiment of the present invention.

[0039] Reference manual attached Figure 3 The diagram shows a simplified schematic of a single-piece frame structure provided in an embodiment of the present invention.

[0040] like Figure 3 As shown in the figure, 1 is the crank, 2 is the connecting rod, 3 and 6 are the heald blades, the blade arm O2B in the heald blade 3 is the heald arm, 4 and 7 are the heald frame connecting rods, 5 is the blade connecting rod, and 8 is the heald frame.

[0041] Reference manual attached Figure 4 The diagram shows a schematic of the adjustment arc of the lifting arm provided in an embodiment of the present invention.

[0042] like Figure 4 As shown, the midpoint of the swing angle arc of the heddle frame lifting arm should be on the adjustment arc under different opening amounts. This will make the upper and lower swing angles of the cutter arm O2C the same as the swing of the heddle frame lifting arm, so that the upper and lower strokes of the heddle frame about the heddle level position are the same.

[0043] Reference manual attached Figure 5 The diagram shows the distribution of the midpoint of the swing angle arc provided in an embodiment of the present invention;

[0044] like Figure 5As shown, for a four-bar linkage, the midpoints of the rocker's swing angle arcs at different rocker lengths are approximately distributed on an arc centered on the crank's rotation center and with the connecting rod length as the radius. Since it's impossible to make the midpoints of the heald arm's swing angle arcs for each heald frame at different opening sizes lie on a single arc, the design of the four-bar linkage for each heald frame must ensure that the arc segments distributed at the midpoints of the swing angle arcs corresponding to different opening sizes of each heald frame approximately coincide. This ensures that the midpoints of the rocker's swing angle arcs for each heald frame at different opening sizes are approximately on a single arc. Then, by fitting all the midpoints of the swing angle arcs, a smaller error arc is obtained as the adjustment arc for the heald arm.

[0045] Reference manual attached Figure 6 The diagram shows a schematic of the crank angle with two openings in the heald frame provided in an embodiment of the present invention.

[0046] like Figure 6 As shown, to facilitate the design of the motor motion curve, the crank angle corresponding to the two openings of the heald frame should be 180°. This requires the extreme position angle θ of the four-bar linkage to be 0° and the crank angles β1 = β2 = 90°. β1 and β2 are the angles between the crank positions corresponding to the rocker arm at the left extreme position (corresponding to the highest displacement of the heald frame) and the two crank positions corresponding to the rocker arm at the middle position of the swing angle (corresponding to the heald flat position), respectively. Upper shedding refers to the upper opening motion, Lower shedding refers to the lower opening motion, and The shedding position refers to the heald flat position (i.e., the symmetrical middle position of the opening).

[0047] This invention provides a method for designing a four-bar linkage based on a multi-piece heald frame, which may include the following steps:

[0048] S1: Based on the requirements of the opening process, determine the design requirements of the heald frame four-bar linkage, which includes: crank, rocker arm, connecting rod and frame.

[0049] The heald frame, in a loom, is the component used to control the warp yarn shedding, ensuring the smooth passage of the shuttle. A four-bar linkage is a mechanism composed of four links (crank, rocker, connecting rod, and frame), used to convert input rotational motion into complex planar motion trajectories. The crank is one of the links in the four-bar linkage, typically driving the movement of other parts through rotation. The rocker is another link in the four-bar linkage, connected to the crank, controlling the up-and-down movement of the heald frame. The connecting rod connects the crank and the rocker, used to transmit motion. The frame is the fixed part of the four-bar linkage, supporting and connecting the other links.

[0050] It should be noted that by clarifying the design requirements of the four-bar linkage mechanism of the heald frame based on the requirements of the opening process, it is ensured that the four-bar linkage mechanism can accurately adjust the opening amount in actual application to meet the requirements of different fabrics. This avoids problems such as inconsistent movement or insufficient control precision caused by improper mechanism design, making the opening amount adjustment of each heald frame accurate and reliable, and having high consistency in the coordinated work of multiple heald frames, thereby improving the overall weaving efficiency and quality.

[0051] In one possible implementation, the design requirements specifically include:

[0052] (1) The crank rotation centers of the frame are spaced at a predetermined distance along their axes, and the crank rotation centers are arranged in a stepped manner.

[0053] (2) The midpoint of the heddle frame under different opening amounts should be on the heddle arm adjustment arc.

[0054] (3) To facilitate adjustment, the adjustment arc of the lifting arm is designed as a circular arc.

[0055] (4) The same heddle-lifting blades are used for the heddle frames.

[0056] (5) The midpoint of the lifting arm swing angle arc of each heald frame under different opening amounts should be on the same arc line.

[0057] (6) The opening amount can be adjusted by adjusting the length of the rocker arm in the four-bar linkage and adjusting the rocker arm's swing angle.

[0058] (7) The extreme position angle, the first crank angle and the second crank angle of the four-bar linkage under different opening amounts respectively reach the corresponding preset angles.

[0059] Reference manual attached Figure 7 The diagram shows a schematic design of a four-bar linkage provided in an embodiment of the present invention.

[0060] like Figure 7 As shown, O1 is the rotation center of the crank, O2 is the rotation center of the rocker arm, c0 represents the initial length of the rocker arm, ψ0 is the swing angle without quick-return characteristics, γ is the angle between the rocker arm and the horizontal direction, b is the length of the connecting rod, and d is the length of the frame. B0 is the fitted position of the midpoint of the rocker arm swing angle arc under different opening amounts, and B1 and B2 are the endpoints of the rocker arm at its extreme positions. This figure demonstrates how, by rationally arranging the parameters of the four-bar linkage, the motion trajectories of each heald frame are coordinated under different opening amounts, satisfying the design goals of no quick-return characteristics and adjustment accuracy.

[0061] Reference manual attached Figure 8 The diagram illustrates the relationship between the opening amount of the heald frame and the swing angle of the heald lifting arm according to an embodiment of the present invention.

[0062] like Figure 8 O2 is the rotation center of the heddle arm, L is the length of the cutter arm O2C, ψ is the swing angle of the heddle arm, and h is the opening amount of the heddle frame. Point E represents the middle of the heddle frame, E1 and E2 are the endpoints of the heddle frame at the maximum and minimum opening positions, respectively, and C1 and C2 are the linkage connection points of the heddle arm in the corresponding states. This diagram visually illustrates the correspondence between the opening amount h and the swing angle ψ, providing a basis for establishing a mathematical model between the opening amount and the mechanism parameters, thereby guiding the optimized design of the four-bar linkage.

[0063] S2: Based on the design requirements, using a four-bar linkage design method with known crank length and rocker swing angle, design the crank rotation center of the four-bar linkage.

[0064] Among them, the no-quick-return characteristic means that the four-bar linkage oscillates smoothly without sharp rotation during movement, ensuring stable operation of the mechanism. The crank rotation center refers to the point of rotation where the crank is fixed to one end of the frame. It is the starting center of the four-bar linkage's motion, and its position determines the overall motion characteristics and spatial arrangement of the machine.

[0065] It should be noted that by combining the non-quick-return characteristic and scientifically determining the crank rotation center position, it is possible to effectively avoid sudden changes or violent shaking during the operation of the mechanism, thereby significantly improving the stability and adjustment accuracy of the heald frame movement, and providing a precise basis for subsequent mechanism size calculation and spatial layout.

[0066] In one possible implementation, S2 specifically includes:

[0067] S201: Calculate the range of heald arm swing angles corresponding to all openings in the heald frame:

[0068]

[0069] Where ψ represents the swing angle of the heddle arm, h represents the opening amount, and L represents the length of the cutter arm of the four-bar linkage of the heddle frame.

[0070] The opening amount refers to the width at which the warp yarns separate vertically during weaving, representing the crucial space for the shuttle to pass through the fabric and form weft yarn interlacing. The heddle arm connects the four-bar linkage to the heddle frame; its swinging motion drives the heddle frame up and down, achieving the opening. The swing angle range refers to the minimum to maximum swing angle of the heddle arm corresponding to different opening amounts, reflecting the motion limits of the heddle frame.

[0071] Specifically, by calculating the range of heddle arm swing angles corresponding to different shedding amounts, precise control of the heddle frame's up and down stroke can be achieved, ensuring that the shedding adjustment range meets weaving requirements.

[0072] S202: Within the range of the heddle arm swing angle, select a swing angle value as the swing angle that satisfies the no-quick-return characteristic, and determine the crank length.

[0073] S203: Calculate the rocker arm length that satisfies the no-quick-return characteristic based on the crank length and swing angle:

[0074]

[0075] Where c0 represents the rocker arm length when the no-quick-return characteristic is satisfied, a represents the crank length, and ψ0 represents the swing angle when the no-quick-return characteristic is satisfied.

[0076] S204: Determine the limit position of the rocker arm's swing angle by combining the crank length and the rocker arm length.

[0077] Among them, the extreme angle position refers to the leftmost and rightmost extreme angle positions that the joystick can reach during its entire movement, which are the boundary states of the frame's up and down movement.

[0078] It should be noted that by combining the lengths of the crank and the rocker arm, the maximum swing angle range that the rocker arm may reach during movement is accurately determined, thereby providing boundary references for the maximum opening and minimum closing position of the heald frame, ensuring that the mechanism operates without conflict and that the motion trajectory is reasonable, and improving the reliability and adjustment accuracy of the system.

[0079] S205: Design the crank rotation center based on the extreme position of the swing angle.

[0080] Specifically, based on the extreme position of the swing angle, the position of the crank rotation center is rationally designed so that the four-bar linkage has good motion coordination and spatial adaptability throughout the opening process, effectively avoiding mechanism interference and improving the stability of the heald frame operation and the flexibility of the structural layout.

[0081] In this invention, the rocker arm rotation center is set to O2, and the angle γ between the right limit position of the rocker arm swing angle and the horizontal direction is determined. B1 and B2 are the two endpoints of the rocker arm at its left and right limit positions. The crank rotation center is selected for each heddle frame at different positions on the extension line of B1B2. The distance from the crank rotation center selected at different positions on the extension line of B1B2 to the midpoint B0 of B1B2 is equal to the connecting rod length b of the corresponding mechanism. Therefore, the circles of each heddle frame with the crank rotation center as the center and the connecting rod length as the radius approximately coincide at B0.

[0082] Furthermore, since ψ0 is within the swing angle range of the heald arm, the length adjustment range of the rocker arm is around c0. Therefore, the arc segment at B0 is the arc segment where the midpoint of the swing angle arc of the rocker arm is distributed under different opening amounts of each heald frame.

[0083] In one possible implementation, after S2, the following is also included:

[0084] Determine the frame length based on the crank rotation center.

[0085] Determine the link length based on the frame length:

[0086]

[0087] Where b represents the link length and d represents the frame length.

[0088] It should be noted that by deriving the frame length from the determined crank rotation center position and further calculating the connecting rod length, the geometric parameters of the four-bar linkage can be coordinated and matched, thereby achieving a reasonable spatial layout of the components of the mechanism, improving the overall structural stability and motion accuracy, and avoiding mechanism interference and abnormal motion.

[0089] Reference manual attached Figure 9 The diagram shows a mathematical model provided in an embodiment of the present invention.

[0090] like Figure 9 As shown, O1 is the rotation center of the crank, O2 is the rotation center of the rocker arm, and a, b, c, and d represent the lengths of the crank, connecting rod, rocker arm, and frame, respectively. The rotation trajectory circle of the crank is drawn with O1 as the center and a as the radius. β1 and β2 represent the angles between the crank at its left and right extreme positions and its intermediate position, respectively, and θ is the extreme position angle. By constructing this model, the motion boundaries and angular parameters of the four-bar linkage under different opening amounts can be clearly defined, providing a theoretical basis for optimizing structural design and motor control.

[0091] S3: Based on the crank rotation center, normalize the model of the four-bar linkage and determine its mathematical model.

[0092] It should be noted that by normalizing the model to unify the structural parameters of the four-bar linkage into a dimensionless form, and by combining the determined crank rotation center to establish a mathematical model, the influence of different parameters on the motion characteristics of the mechanism can be analyzed, thereby improving the versatility of the design and the efficiency of comparative analysis, and providing a theoretical basis for subsequent parameter optimization and mechanism behavior prediction.

[0093] In one possible implementation, S3 specifically includes:

[0094] S301: Set the crank length to unit length.

[0095] S302: Combining crank length and geometric relationships, establish mathematical models for extreme position angles, first crank angle, and second crank angle.

[0096] Specifically, by combining the crank length with geometric relationships, a mathematical model is established for the extreme position angle θ, the first crank angle β1, and the second crank angle β2. This model can accurately describe the key motion characteristics of the four-bar linkage, providing a rigorous mathematical basis for analyzing the opening symmetry, determining whether the no-quick-return characteristic is met, and optimizing the mechanism's structural parameters, thereby improving the scientific nature of the design and the precision of the control.

[0097] In one possible implementation, the mathematical model is as follows:

[0098]

[0099] Where θ represents the extreme position angle, β1 represents the first crank angle, β2 represents the second crank angle, a represents the crank length, b represents the connecting rod length, c represents the rocker length, d represents the frame length, B represents the midpoint of the rocker swing angle arc, O1 represents the crank rotation center, and O2 represents the rocker rotation center.

[0100] S4: Based on the mathematical model, analyze the optimal ratio between the frame length and the crank length, and calculate the link parameters of the heald frame four-bar linkage according to the optimal ratio.

[0101] It should be noted that by analyzing mathematical models to determine the optimal ratio between the frame and crank lengths, and calculating the parameters of each link in the four-bar linkage, the optimal matching of structural dimensions and motion performance can be achieved. This ensures the stability, accuracy, and symmetry of the heald frame during the adjustment of the opening amount, thereby improving the efficiency and reliability of the overall weaving system.

[0102] In one possible implementation, S4 specifically includes:

[0103] S401: Select multiple heald frame four-bar linkages with different ratios between frame length and crank length.

[0104] S402: Determine the rocker length adjustment range for each heald frame four-bar linkage to satisfy the opening amount of all heald frames:

[0105]

[0106] Where κ represents the rocker arm angle.

[0107] S403: Analyze the changes in the extreme position angle, first crank angle, and second crank angle of each four-bar linkage within the rocker arm length adjustment range.

[0108] Specifically, by analyzing the variation patterns of the extreme position angle, first crank angle, and second crank angle of different four-bar linkages within the rocker length adjustment range, the influence of the frame length to crank length ratio on the motion performance of the mechanism is evaluated. This helps to select the optimal structural parameters, making the crank angle closer to the ideal value, thereby improving the symmetry of the opening action and the accuracy of motor control, and optimizing the overall operation effect of the mechanism.

[0109] S404: Based on the analysis results, determine the optimal ratio between the frame length and the crank length.

[0110] S405: Calculate the link parameters of the four-bar linkage based on the optimal ratio.

[0111] S5: Based on the link parameters, establish a Cartesian coordinate system for the four-bar linkage.

[0112] It should be noted that establishing a Cartesian coordinate system for the four-bar linkage based on the determined link parameters can accurately describe the geometric position and relative relationship of each component in space, which facilitates subsequent motion trajectory analysis, structural interference verification and arc fitting calculation, improves the visualization and calculation accuracy of the mechanism design, and enhances the intuitiveness and accuracy of parameter adjustment.

[0113] Reference manual attached Figure 10 The diagram illustrates the calculation of the crank rotation center and the midpoint of the swing angle arc provided in an embodiment of the present invention.

[0114] like Figure 10 With O2 as the center of rotation of the rocker arm, O1 as the center of rotation of the crank arm, c as the length of the rocker arm, b as the length of the connecting rod, d as the length of the frame, ψ0 as the reference swing angle, and γ as the angle between the right limit swing angle and the horizontal direction. and These represent the current and initial angular positions, respectively. B0 is the midpoint of the swing angle arc, B1 and B3 are the endpoints of the joystick in the limit state of the opening amount, and B1′ and B2′ are the corresponding points in other positions. By accurately calculating the positional relationship of these points in the Cartesian coordinate system (X and Y axes), the motion trajectories of multiple heald frames can be coordinated and consistent, a reasonable adjustment arc can be fitted, and the adjustment accuracy and opening synchronization of the mechanism can be improved.

[0115] Reference manual attached Figure 11 The diagram shows the variation of the extreme position angle and crank rotation angle provided in the embodiment of the present invention.

[0116] like Figure 11 As shown in the figure, the left figure illustrates how the extreme position angle θ changes with the increase of the rocker arm length c under different frame lengths (d1, d2, d3). θ decreases rapidly under condition d1, while the change is gradual under conditions d2 and d3. In the right figure, the solid line represents the first crank angle β1, and the dashed line represents the second crank angle β2. It can be seen that β1 and β2 deviate to varying degrees with the change of c at each d value, but overall remain close to 90°. This figure is used to analyze the influence of frame length and rocker arm length on the motion performance of the mechanism, providing theoretical support for selecting the optimal parameter combination and achieving a near-ideal motion state (θ≈0, β1, β2≈90°).

[0117] Reference manual attached Figure 12 The diagram shows the position of the rotation center of the heddle frame crank and the midpoint of the swing angle arc provided in the embodiment of the present invention.

[0118] like Figure 12 Different symbols are used to show the position of the center of rotation of the heddle frame crank and the midpoint of the swing angle arc.

[0119] S6: In a Cartesian coordinate system, determine the position of the crank rotation center and the position of the midpoint of the rocker arm swing arc of the four-bar linkage.

[0120] The crank rotation center position refers to the fixed point around which the crank rotates in a four-bar linkage, determining the starting position and geometric relationship of the entire mechanism's motion. The rocker arm swing arc midpoint position refers to the geometric midpoint of the rocker arm's swing path during adjustment, reflecting its motion symmetry and adjustment center.

[0121] It should be noted that, in the established Cartesian coordinate system, accurately determining the position of the crank rotation center and the midpoint of the rocker arm swing arc of the four-bar linkage of the heald frame can realize the spatial collaborative design between multiple heald frames, ensure the consistency of the motion trajectory distribution of each rocker arm, provide basic data for the fitting and error analysis of the subsequent adjustment arc, and improve the rationality of the structural layout and the synchronous accuracy of the opening adjustment.

[0122] In one possible implementation, the calculation method for the crank rotation center position and the midpoint position of the rocker arm swing angle arc is as follows:

[0123]

[0124] Where x0 and y0 represent the coordinates of the crank rotation center, This represents the angle between the joystick and the positive x-axis when the joystick is at the midpoint of its swing angle. The x-axis represents the angle between the frame and the positive x-axis, and x and y represent the coordinates of the midpoint of the rocker arm's swing angle arc.

[0125] Reference manual attached Figure 13 The diagram shows a schematic of the adjustment arc error swing angle provided in an embodiment of the present invention.

[0126] like Figure 13 As shown, O2 is the center of rotation of the rocker arm, B1 and B2 are the endpoints of the rocker arm's extreme positions, B is the midpoint of the actual swing arc, B′ is the corresponding point on the fitted arc, and δ is the error swing angle. This figure illustrates the deviation that exists in the fitting process of the adjustment arc and introduces the error swing angle δ as an indicator to measure the fitting accuracy. Through this figure, the degree of deviation between the fitted arc and the actual motion path can be quantitatively evaluated, providing an effective basis for optimizing the adjustment trajectory of the heald arm and improving the consistency and adjustment accuracy of the multi-hedron frame opening.

[0127] S7: Based on the position of the crank rotation center and the position of the midpoint of the rocker arm swing arc, fit the adjustment arc of the heel arm and calculate the error swing angle of the fitted arc.

[0128] The heddle arm adjustment arc is an approximate arc obtained by fitting the midpoints of multiple rocker arm swing angle arcs, used to guide the adjustment trajectory of the heddle arm with different opening amounts. The error swing angle refers to the angular deviation between the midpoint of the actual swing angle arc and the fitted arc, used to evaluate the fitting accuracy.

[0129] It should be noted that by fitting the midpoints of multiple rocker arm swing angle arcs to generate a unified adjustment arc and calculating the fitting error swing angle, the consistency of the motion trajectory of different heald frames during the adjustment process can be effectively evaluated, the design of the heald lifting arm slider path can be optimized, thereby improving the synchronization accuracy and the stability of the opening adjustment when multiple heald frames share the adjustment mechanism.

[0130] S8: Based on the link parameters, the crank rotation center position, the midpoint position of the rocker arm swing arc, and the error swing angle, constrain the four-bar linkage of the heald frame to complete the design of the four-bar linkage of the heald frame.

[0131] It should be noted that by comprehensively considering key factors such as link parameters, crank rotation center position, rocker swing arc midpoint position, and error swing angle, multi-dimensional constraints and optimizations are applied to the four-bar linkage of the heald frame. This enables consistency of motion between heald frames and effective avoidance of structural interference while meeting the opening adjustment accuracy requirements, thereby achieving a stable, reliable, and high-precision mechanism design.

[0132] The beneficial effects of the technical solutions provided by the embodiments of the present invention include at least the following:

[0133] In this embodiment of the invention, by designing the crank rotation center of the four-bar linkage without quick-return characteristics, it is ensured that the rocker's motion does not undergo abrupt changes or instability, achieving a smooth adjustment effect. This avoids conflicts caused by mutual interference between links and ensures that multiple heald frames operate in a coordinated manner within the same system. A normalized model of the four-bar linkage is established based on the crank rotation center, clarifying the relationship between the rocker length and the crank angle. This ensures that the rocker does not exhibit quick-return characteristics during the adjustment of the opening amount, guaranteeing smooth motion of each heald frame under different opening amounts. By determining the optimal ratio between the frame length and the crank length and calculating the link parameters, the motion of the four-bar linkage becomes more precise. To ensure that the opening amount of each heald frame is consistent and accurate under different opening amounts, a Cartesian coordinate system is established, and the position of the crank rotation center is determined in this coordinate system. This further optimizes the accuracy and consistency of the opening amount adjustment. By determining the position of the crank rotation center and the position of the midpoint of the rocker arm swing angle arc, it is ensured that the midpoint of the heald lifting arm swing angle arc of each heald frame is located on the same arc line, avoiding the inconsistency problem in the existing design. By fitting the rocker arm swing angle arc, an arc line with small error is obtained as the adjustment arc of the heald lifting arm, making the adjustment arc of each heald frame accurate and consistent, thereby achieving high-precision opening amount adjustment and reducing the manufacturing cost of the heald lifting blade.

[0134] Reference manual attached Figure 14The diagram shows a structural schematic of a four-bar linkage design system based on a multi-piece heald frame provided by an embodiment of the present invention.

[0135] This invention provides a four-bar linkage design system 20 based on a multi-piece truss frame, comprising: a processor 201 and a memory 202;

[0136] The memory 202 stores programs or instructions that can run on the processor 201. When the program or instructions are executed by the processor 201, they implement the steps of the above-described four-bar linkage design method based on a multi-piece heddle frame and achieve the same technical effect. To avoid repetition, the present invention will not elaborate further.

[0137] It should be understood that the processor 201 in this embodiment of the invention may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0138] It should also be understood that the memory 202 in the embodiments of the present invention can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDR SDRAM), enhanced synchronous DRAM (ESDRAM), synchronous linked DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0139] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0140] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0141] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0142] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0143] In the several embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0144] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0145] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0146] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0147] This invention provides a readable storage medium comprising: storing a program or instructions on the readable storage medium, wherein when the program or instructions are executed by a processor, the program or instructions implement the steps of the above-described four-bar linkage design method based on a multi-piece set frame, and can achieve the same technical effect. To avoid repetition, this invention will not elaborate further.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for a four-bar linkage based on a multi-piece heald frame, characterized in that, include: S1: Based on the requirements of the opening process, the design requirements of the heald frame four-bar linkage are determined, wherein the heald frame four-bar linkage includes: crank, rocker, connecting rod and frame; S2: Based on the design requirements, using a four-bar linkage design method with known crank length and rocker swing angle, the crank rotation center of the heald frame four-bar linkage is designed. S3: Based on the crank rotation center, perform normalized modeling of the heald frame four-bar linkage to determine the mathematical model of the heald frame four-bar linkage; S4: Based on the mathematical model, analyze the optimal ratio between the frame length and the crank length, and calculate the link parameters of the heald frame four-bar linkage according to the optimal ratio; S5: Based on the link parameters, establish a Cartesian coordinate system for the four-bar linkage of the helical frame; S6: In the plane rectangular coordinate system, determine the position of the crank rotation center and the position of the midpoint of the rocker arm swing angle arc of the four-bar linkage; S7: Based on the crank rotation center position and the midpoint position of the rocker arm swing angle arc, fit the heddle arm adjustment arc and calculate the error swing angle of the fitted arc; S8: Based on the link parameters, the crank rotation center position, the midpoint position of the rocker arm swing arc, and the error swing angle, constrain the heald frame four-bar linkage to complete the design of the heald frame four-bar linkage.

2. The design method for a four-bar linkage based on a multi-piece heald frame according to claim 1, characterized in that, The design requirements specifically include: (1) The crank rotation centers of the frame are spaced at a predetermined distance along their axes, and the crank rotation centers are arranged in a stepped manner. (2) The midpoint of the heddle frame under different opening amounts should be on the heddle arm adjustment arc; (3) To facilitate adjustment, the adjustment arc of the lifting arm is designed as a circular arc; (4) The same heddle frame is used; (5) The midpoints of the lifting arm swing angle arcs of each heald frame under different opening amounts should be on the same arc line; (6) The opening amount can be adjusted by adjusting the length of the rocker arm in the four-bar linkage and adjusting the rocker arm's swing angle. (7) The extreme position angle, the first crank angle and the second crank angle of the four-bar linkage under different opening amounts respectively reach the corresponding preset angles.

3. The design method for a four-bar linkage based on a multi-piece heald frame according to claim 1, characterized in that, S2 specifically includes: S201: Calculate the range of heald arm swing angles corresponding to all openings in the heald frame: Where ψ represents the swing angle of the heddle arm, h represents the opening amount, and L represents the length of the cutter arm of the four-bar linkage of the heddle frame; S202: Within the range of the lifting arm swing angle, select a swing angle value as the swing angle that satisfies the no-quick-return characteristic, and determine the crank length; S203: Based on the crank length and swing angle, calculate the rocker arm length that satisfies the no-quick-return characteristic: Where c0 represents the rocker arm length when the no-quick-return characteristic is satisfied, a represents the crank length, and ψ0 represents the swing angle when the no-quick-return characteristic is satisfied; S204: Determine the limit position of the rocker arm's swing angle by combining the crank length and the rocker arm length; S205: Design the crank rotation center based on the swing angle limit position.

4. The design method for a four-bar linkage based on a multi-piece heald frame according to claim 3, characterized in that, Following S2, it also includes: Determine the frame length based on the crank rotation center; Determine the link length based on the frame length: Where b represents the link length and d represents the frame length.

5. The design method for a four-bar linkage based on a multi-piece heald frame according to claim 1, characterized in that, S3 specifically includes: S301: Set the crank length to a unit length; S302: Based on the crank length and geometric relationship, establish the mathematical model regarding the extreme position angle, the first crank angle, and the second crank angle.

6. The design method for a four-bar linkage based on a multi-piece heald frame according to claim 5, characterized in that, The mathematical model is specifically as follows: Where θ represents the extreme position angle, β1 represents the first crank angle, β2 represents the second crank angle, a represents the crank length, b represents the connecting rod length, c represents the rocker length, d represents the frame length, B represents the midpoint of the rocker swing angle arc, O1 represents the crank rotation center, and O2 represents the rocker rotation center.

7. The design method for a four-bar linkage based on a multi-piece heald frame according to claim 1, characterized in that, S4 specifically includes: S401: Select multiple heald frame four-bar linkages with different ratios between the frame length and the crank length; S402: Determine the rocker length adjustment range of each of the four-bar linkages of the heald frame to satisfy all heald frame opening amounts: Where κ represents the rocker arm angle. S403: Analyze the changes in the extreme position angle, the first crank angle, and the second crank angle of each of the four-bar linkages of the helical frame within the range of the rocker arm length adjustment; S404: Based on the analysis results, determine the optimal ratio between the frame length and the crank length; S405: Calculate the link parameters of the four-bar linkage based on the optimal ratio.

8. The design method for a four-bar linkage based on a multi-piece heald frame according to claim 1, characterized in that, The specific calculation methods for the crank rotation center position and the midpoint position of the rocker arm swing angle arc are as follows: Where x0 and y0 represent the coordinates of the crank rotation center, This represents the angle between the joystick and the positive x-axis when the joystick is at the midpoint of its swing angle. The x-axis represents the angle between the frame and the positive x-axis, and x and y represent the coordinates of the midpoint of the rocker arm's swing angle arc.

9. A four-bar linkage design system based on a multi-piece heald frame, characterized in that, include: Processor and memory; The memory stores programs or instructions that can run on the processor, which, when executed by the processor, implement the steps of the four-bar linkage design method based on a multi-piece heald frame as described in any one of claims 1 to 8.

10. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the four-bar linkage design method based on a multi-piece heald frame as described in any one of claims 1 to 8.

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