A main transmission device of a large-tonnage servo press and its optimization method

Abstract

The present invention relates to a main transmission device for a large-tonnage servo press and an optimization method thereof, belonging to the technical field of forging equipment, wherein the device includes a pressure output slider and at least two groups of composite force-amplifying mechanisms connected to the pressure output slider, wherein: each group of composite force-amplifying mechanisms includes a driving slider, an upper connecting rod, a triangular elbow link, and a lower connecting rod, wherein one end of the upper connecting rod is hinged to the driving slider, and the other end is hinged to the first corner end of the triangular elbow link; one end of the lower connecting rod is hinged to the second corner end of the triangular elbow link, and the other end is hinged to the pressure output slider; the third corner end of the triangular elbow link is hinged to a fixing device; the driving slider is connected to a servo motor so as to slide under the drive of the servo motor. The present application can solve the problem of limited tonnage and table size of existing presses.

Description

Technical Field

[0001] The present invention relates to the technical field of forging equipment design, and in particular to a main transmission device of a large-tonnage servo press and an optimization method thereof. Background Art

[0002] With the rapid development of my country's automotive, high-speed rail, aerospace, and other industries, the demand for high-performance forgings continues to increase, placing higher demands on forging equipment. Traditional forging equipment is no longer able to meet the processing requirements of high-lightweight materials such as ultra-high-strength steel, high-strength aluminum alloys, and titanium alloys. Servo presses, with their high precision, high flexibility, high efficiency, low noise, and energy saving, have become the forging equipment of choice.

[0003] Servo presses are developing toward larger tonnage, more flexible forming curves, more pronounced force multiplication, and more diverse drive methods. However, this development is constrained by the research and development of servo motors, servo control technology, and the kinematic characteristics of the main drive mechanism. The kinematic characteristics of the press's active drive mechanism play a crucial role. As a key component of a servo press, the kinematic characteristics of the main drive mechanism directly impact the press's forming performance and service life. A high-performance servo press active drive mechanism not only meets the demands of the stamping process but also reduces the load on the servo motor and the difficulty of servo control.

[0004] Chinese patent CN109732967A discloses a two-motor driven double-elbow large-tonnage AC servo press with adjustable die height. The invention is driven by two servo motors placed on the top and has a good force-increasing effect. However, the servo motors placed on the top have a vertical height that is too large compared to horizontally opposed distribution, and there may be a problem of horizontal unbalanced load on the slider. The use of a synchronous belt as a transmission mechanism makes it difficult to simultaneously transmit large motor power and high belt speed, which limits its application in servo press products with larger tonnage. Chinese invention patent CN106273605A proposes a method for optimizing the transmission mechanism of a toggle servo press. After optimization, this method reduces the load of the servo motor, but the optimization target is relatively single, and the sensitivity of the design variables is still unknown. In addition, when optimizing the mechanism, each rod is regarded as a rigid body, and the actual optimization effect is not good.

[0005] Currently, the tonnage of servo presses has reached 2500 tons. Further increasing the servo motor power will lead to a surge in costs and easily cause uneven deformation load distribution. It is necessary to provide a main drive device for a large-tonnage servo press and further optimize the design method to address the problems of limited press tonnage and table size, thereby improving the press's forming capacity. Summary of the Invention

[0006] In view of this, it is necessary to provide a main transmission device of a large-tonnage servo press and an optimization method thereof to solve the problem of limited tonnage and table size of existing presses.

[0007] In order to solve the above problems, the present invention provides a main transmission device of a large-tonnage servo press, comprising a pressure output slider and at least two groups of composite force amplification mechanisms connected to the pressure output slider, wherein: each group of the composite force amplification mechanisms comprises a driving slider, an upper connecting rod, a triangular elbow rod and a lower connecting rod, wherein one end of the upper connecting rod is hinged to the driving slider, and the other end is hinged to the first angular end of the triangular elbow rod; one end of the lower connecting rod is hinged to the second angular end of the triangular elbow rod, and the other end is hinged to the pressure output slider; the third triangular end of the triangular elbow rod is hinged to a fixing device; the driving slider is connected to a servo motor so as to slide under the drive of the servo motor.

[0008] In a possible implementation, the triangular toggle lever is composed of three connecting rods hinged to each other.

[0009] In a possible implementation, at least one of the triangular elbow link, the upper connecting rod, and the lower connecting rod is a hollow structure whose thickness is proportional to the load-bearing capacity.

[0010] In a possible implementation, there are two groups of compound force amplifying mechanisms, and the two groups of compound force amplifying mechanisms are symmetrically arranged at the upper end of the pressure output slider.

[0011] In a possible implementation, the third triangular end of the triangular elbow is fixed inside the area formed by the pressure output slider and the driving slider.

[0012] In a possible implementation, it also includes a gear mechanism and a ball screw mechanism provided on the gear mechanism. The driving slider is connected to the ball screw mechanism, and the servo motor drives the gear mechanism to rotate, and then the ball screw mechanism on the gear mechanism drives the driving slider to slide in the horizontal direction.

[0013] The present invention also provides an optimization method for the above-mentioned large-tonnage servo press main transmission device, including: S1: establishing a parametric model of the press transmission mechanism based on the geometric structure of the servo press transmission device; S2: making the rods flexible, using the pressure output slider and the driving slider as rigid elements, and then optimizing the parametric model of the press transmission mechanism to obtain a rigid-flexible coupling model of the press transmission mechanism; S3: taking the rod lengths of the upper connecting rod, the triangular elbow rod and the lower connecting rod as design variables, and constructing multiple optimization targets, taking the design variables as individuals in the population, and using a hierarchical genetic algorithm to iteratively optimize the multiple optimization targets in sequence to obtain the optimal rod length combination, and inputting the optimal rod length combination into the rigid-flexible coupling model of the press transmission mechanism for simulation analysis to achieve the optimization of the servo press main transmission device.

[0014] In a possible implementation, step S3 further includes obtaining the sensitivity of each design variable to each optimization objective, and treating a design variable with a sensitivity less than a preset threshold as a constant.

[0015] In one possible implementation, the optimization objectives include at least two of the following: maximizing the force multiplication ratio at the nominal force generation point, minimizing the speed at the nominal force generation point, or minimizing the acceleration at the nominal force generation point; and a hierarchical genetic algorithm is used to perform iterative optimization on multiple optimization objectives in sequence, specifically: taking the values ​​of each design variable as the initial population, screening and iterating through the constraints, maximizing the force multiplication ratio, minimizing the speed, and minimizing the acceleration in sequence, retaining the populations that meet the conditions, and using the genetic algorithm to select, cross over, and mutate the populations that do not meet the conditions to generate a new generation of populations, which are screened and iterated again to obtain the global optimal solution of multiple optimization objectives, that is, the optimal rod length.

[0016] In a possible implementation, the step S2 of making the rod flexible is as follows: making the rod flexible if the elasticity is greater than a preset threshold.

[0017] The beneficial effects of the present invention are:

[0018] This application designs multiple sets of composite force-amplifying mechanisms, which correspond to multiple servo motors, thereby realizing the decentralization of driving force, avoiding the problem of power limitation of a single servo motor, and improving the output pressure of the press. Furthermore, the composite force-amplifying mechanism selects a triangular elbow link to replace the ordinary elbow link mechanism, and combines the multi-link and triangular elbow link as the force-amplifying mechanism of the press transmission mechanism, thereby reducing the maximum torque of the servo motor by about 8%, and thereby converting more force into the pressure of the press. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic structural diagram of an embodiment of a main transmission device for a large-tonnage servo press provided by the present invention;

[0020] Figure 2 A schematic diagram of the motion of the main transmission device of the large-tonnage servo press provided by the present invention;

[0021] Figure 3 A schematic diagram of the motion analysis of the main transmission device of the large-tonnage servo press provided by the present invention;

[0022] Figure 4 This is a schematic diagram of the simulation of the rigid-flexible coupling model of the dual-servo driven main transmission mechanism of the large-tonnage press designed by the present invention;

[0023] Figure 5 for Figure 4 Schematic diagram of kinematic analysis results;

[0024] Figure 6This is a flow chart of the hierarchical genetic algorithm of the present invention;

[0025] Figure 7 This is a comparison diagram of the slider displacement curves before and after the multi-objective optimization of the main transmission mechanism of the press according to the present invention;

[0026] Figure 8 This is a comparison diagram of the slider speed curves before and after the multi-objective optimization of the main transmission mechanism of the press;

[0027] Figure 9 This is a comparison diagram of the slider acceleration curves before and after the multi-objective optimization of the main transmission mechanism of the press according to the present invention;

[0028] Figure 10 This is a comparison diagram of the force amplification ratio versus slider displacement curves before and after the multi-objective optimization of the main transmission mechanism of the press according to the present invention. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0030] A specific embodiment of the present invention discloses a main transmission device of a large-tonnage servo press, such as Figure 1 and Figure 2 As shown, it includes a pressure output slider 100 and at least two sets of composite force amplification mechanisms 200 connected to the pressure output slider 100, wherein:

[0031] Each group of the composite force-amplifying mechanism 200 includes a driving slider 210, an upper connecting rod 220, a triangular elbow rod 230 and a lower connecting rod 240, wherein one end of the upper connecting rod 220 is hinged to the driving slider 210, and the other end is hinged to the first corner end of the triangular elbow rod 230; one end of the lower connecting rod 240 is hinged to the second corner end of the triangular elbow rod 230, and the other end is hinged to the pressure output slider 100; the third triangular end of the triangular elbow rod 230 is hinged to a fixing device; the driving slider 210 is connected to the servo motor 300 so as to slide under the drive of the servo motor 300.

[0032] In a further preferred embodiment, the triangular toggle link 230 is composed of three mutually hinged links, namely a first link 231, a second link 232, and a third link 233. The first link 231 and the third link 233 are hinged to form the first corner end of the triangular toggle link 230, the third link 233 and the second link 232 are hinged to form the second corner end of the triangular toggle link 230, and the first link 231 and the second link 232 form the third corner end of the triangular toggle link 230. When the triangular toggle link 230 mechanism of the present application replaces a conventional toggle link mechanism, the servo motor torque can be reduced by approximately 8%, thereby converting more force into pressure. In particular, when multiple triangular toggle links 230 are operating simultaneously, a more significant force-amplifying effect can be achieved.

[0033] In a further preferred embodiment, the connecting rod in the triangular elbow rod 230 is designed to imitate the design of biological bone joints, wherein the connecting rod is a hollow structure with a thickness proportional to the load-bearing capacity, which can ensure lightweighting while meeting the stiffness requirements.

[0034] At least two sets of composite force amplification mechanisms 200 correspond to at least two sets of triangular elbow rods 230, and the third ends of at least two sets of triangular elbow rods 230 are fixed inside the area formed by the pressure output slider 100 and the driving slider 210, thereby realizing the upward and downward movement of the pressure output slider 100.

[0035] In a further preferred solution, the connecting rods of the upper connecting rod 220 and / or the lower connecting rod 240 are hollow structures whose thickness is proportional to the load-bearing capacity.

[0036] In a further preferred embodiment, the main transmission device of the large-tonnage servo press further includes a gear mechanism 400 and a ball screw mechanism 500 disposed on the gear mechanism 400. The gear mechanism 400 includes a first gear 410 and a second gear 420 that mesh with each other. The servo motor 300 is connected to the first gear 410, and the ball screw mechanism 500 is axially fixed to the second gear 420. The servo motor 300 then drives the first gear 410 to rotate, which in turn drives the second gear 420 to rotate, thereby driving the ball screw mechanism 500 to rotate.

[0037] The driving slider 210 is sleeved on the ball screw mechanism 500 and can move horizontally driven by the ball screw mechanism 500 to convert the rotational motion into linear motion.

[0038] A second aspect of the present application provides an optimization method for the main transmission device of the large-tonnage servo press, including the following steps S1 to S3.

[0039] The following embodiments of this application illustrate a force amplification mechanism using two groups of compound force amplification mechanisms 200. These two groups of compound force amplification mechanisms 200 are symmetrically arranged at the upper end of the pressure output slider 100. Therefore, this embodiment utilizes horizontally opposed dual servo motors 300 as the power source, a gear mechanism 400 as the reduction mechanism, and a ball screw mechanism 500 to convert rotational motion into linear motion. Together with a multi-link and symmetrical triangular toggle lever, the force amplification mechanism achieves a nominal pressure of up to 3000T, and the surface dimensions of the pressure output slider 100 can reach 4500×2500mm.

[0040] S1: A parametric model of the servo press transmission mechanism is established based on the geometric structure of the servo press transmission device.

[0041] In this embodiment, since the main transmission device of the dual-servo driven press is symmetrical on both sides and has the same motion laws on both sides, when performing kinematic analysis, studying the motion law of one side can represent the motion law of the entire main transmission mechanism.

[0042] See Figure 3 In this embodiment, points O, A, and B are the third triangular end, first corner end, and second corner end of the triangular elbow 230, respectively. That is, O is the hinge point between the first link 231 and the second link 232, A is the hinge point between the first link 231 and the third link 233, and B is the hinge point between the second link 232 and the third link 233. C represents the center of mass of the pressure output slider 100, D represents the center of mass of the driving slider 210, and E represents the hinge point between the lower link 240 and the pressure output slider 100. For convenience of description, represents the first connecting rod 231, represents the second connecting rod 232, represents the third connecting rod 233, Indicates upper connecting rod 220, Indicates the lower connecting rod 240, represents the distance between point O and point D, represents the distance between C and D, Respectively represent rods corner.

[0043] The kinematic chain of the main transmission mechanism of the press is as follows: the driving slider 210 performs horizontal linear motion as the input of the main transmission mechanism, and then transmits the power to the Then the triangular elbow rod 230 is driven to rotate by the rotating pair, and then the triangular elbow rod 230 is driven to rotate by the rotating pair. Rotate, and finally drive the pressure output slider 100 to move vertically through the rotating pair to complete the processing work.

[0044] According to the structural characteristics of the main transmission mechanism of the press, three closed vector polygons OAB, OAD and DABC can be found. From this, the following equation can be obtained:

[0045] (1)

[0046] in, They are The corresponding rod length.

[0047] Using Euler's formula to expand it, we get:

[0048] (2)

[0049] Since the driving slider 210 performs horizontal linear motion and the pressure output slider 100 performs vertical motion, then:

[0050] (3)

[0051] in, and They represent the ordinate of the driving slider 210 and the abscissa of the pressure output slider 100, respectively. They are design parameters and are known quantities. In the above equations (1) to (3), and 6 components are known, 、 、 、 、 、 、 and There are 8 unknown components. The 8 equations in the simultaneous equations (2) and (3) have a unique solution. The solution is:

[0052] (4)

[0053] in:

[0054] (5)

[0055] Thus, the displacement equation S of the pressure output slider 100 can be solved. The velocity equation V of the pressure output slider 100 can be obtained by taking the derivative of the equation group (2) with respect to time t. The acceleration equation of the slider can be obtained by taking the second derivative of the equation group (2) with respect to time. a 0. The expression is as follows:

[0056] (6)

[0057] See Figure 4In ADAMS, the lengths of each member of the main transmission structure are parameterized as design variables. The geometric relationships between the design variables, derived from the above formula, are used to establish parameterized points. This foundation is used to construct a parametric model of the press's main transmission mechanism, connecting the various components using kinematic pairs. This parametric model automatically generates new active mechanism models as the design variables change.

[0058] S2: Evaluate the elasticity of the upper connecting rod, the triangular elbow rod, and the lower connecting rod, make the rods with elastic deformation greater than a preset threshold flexible, use the pressure output slider and the driving slider as rigid elements, and then optimize the parametric model of the press transmission mechanism to obtain a rigid-flexible coupling model of the press transmission mechanism.

[0059] The elasticity of the upper link, triangular elbow link, and lower link can be evaluated, and the rods with elastic deformation greater than a preset threshold can be made flexible.

[0060] Please refer to Figure 5 Utilizing the flexibility tools in ADAMS, the press's main transmission mechanism was made flexible. The drive and pressure output sliders in the press's main transmission mechanism have large cross-sectional dimensions and relatively small relative displacements. Therefore, to simplify the simulation model, the drive and pressure output sliders were treated as rigid bodies during the rigid-flexible coupling simulation, while the remaining members were made flexible. Specifically, the upper connecting rod, triangular elbow, and lower connecting rod of the press's main transmission mechanism were made flexible, with the material defined as 40Cr. The finite element mesh size was set to 40mm, and the number of segments was set to 8. This yielded the kinematic analysis results.

[0061] S3: The rod lengths of the upper connecting rod, the triangular elbow rod, and the lower connecting rod are used as design variables, and multiple optimization objectives are constructed. The design variables are used as individuals in the population. A hierarchical genetic algorithm is used to iteratively optimize the multiple optimization objectives in sequence to obtain the optimal rod length combination. The optimal rod length combination is input into the rigid-flexible coupling model of the press transmission mechanism for simulation analysis.

[0062] S31: Select design variables

[0063] The main factor affecting the displacement, speed and acceleration of the pressure output slide of the main transmission machine of the press is the length of each rod. Therefore, the length of the upper connecting rod, the triangular elbow rod and the lower connecting rod is taken as the optimization target. Therefore, there are 10 design variables in this embodiment, namely, the rod length, the length of the upper connecting rod, the triangular elbow rod and the lower connecting rod. Length , and symmetrical members Length The main transmission mechanism of the press designed in this application is a symmetrical structure. In order to ensure the same movement at both ends of the symmetry, the length of the rods at both ends should be the same, that is, 、 、 、 、 , thus the 10 design variables are simplified to 5, that is, the design variable X for the multi-objective optimization design of the main transmission mechanism of the dual servo drive press is:

[0064]

[0065] S32: Constructing multiple optimization objectives

[0066] A. Power amplification ratio

[0067] The force amplification ratio of the press main transmission mechanism at the nominal force generation point is taken as the first optimization target of the multi-objective optimization of the press main transmission mechanism. The corresponding objective function expression is:

[0068] (7)

[0069] Where, T is the forming force of the press, is the maximum driving force of the driving slider.

[0070] B. Speed ​​of pressure output slider

[0071] The minimum absolute value of the speed of the press output slider at the nominal force generation point is taken as the second optimization goal of the multi-objective optimization of the press main transmission mechanism. The corresponding objective function expression is:

[0072] (8)

[0073] in, is the displacement of the pressure output slider, t For time, h is the location of the point where the nominal force occurs.

[0074] C. Acceleration of the pressure output slider

[0075] The acceleration at the point where the nominal force of the press is generated is taken as the third optimization objective of the multi-objective optimization of the main transmission mechanism of the press. The corresponding objective function expression is:

[0076] (9)

[0077] Therefore, the objective function of the multi-objective optimization is to minimize the speed and acceleration at the nominal force generation point and maximize the force multiplication ratio.

[0078] In a further preferred solution, it also includes performing sensitivity analysis on the design variables.

[0079] When selecting design variables, the degree of influence of each design variable on each objective function can be analyzed. That is, a sensitivity analysis of the design variables on each objective function can be performed to find design variables with a low impact on each objective function. When the genetic algorithm is finally used to optimize the main transmission mechanism for multiple objectives, the design variables with low sensitivity can be treated as constants. This can reduce the number of design variables, simplify the optimization model, and improve optimization efficiency and accuracy. The sensitivity analysis of the design variables in this embodiment is shown in Table 1 below.

[0080] Table 1: Sensitivity of design variables to optimization objectives

[0081]

[0082] It can be seen from the results in Table 1 above that in this embodiment, the design variables 、 、 The sensitivity of the three optimization objective functions is very high. When optimizing the multi-objective optimization of the main transmission mechanism of the press, it cannot be treated as a constant. The design variables and The sensitivity of the three optimization objective functions is low. When optimizing the multi-objective optimization of the main transmission mechanism of the press, they are treated as constants. Therefore, the five design variables Simplified to three design variables .

[0083] S33: Constructing Constraints

[0084] A. Geometric Constraints

[0085] Since the main transmission mechanism of the press has requirements on the size of the occupied space, and the size of each rod should not be too long, according to the design requirements, the length range of each rod is:

[0086] (10)

[0087] B. Performance constraints

[0088] Triangular toggle angle constraint: According to the working characteristics of the triangular toggle mechanism, the two sides of the triangular toggle and Angle exist When the dynamic performance of the triangular elbow is better, the main transmission mechanism of the press should meet the following conditions:

[0089] (11)

[0090] The triangular toggle has constraints. According to the characteristics of the triangular toggle structure, when the angle between the triangular toggle and the lower link is 180°, the force amplification ratio of the triangular toggle mechanism is the largest. Therefore, the main transmission mechanism of the press should meet the following requirements:

[0091] (12)

[0092] Slider stroke constraint: According to the design requirements, the dual servo drive press designed in this invention has a drive slide stroke of S = 400 mm. During the optimization process, the design variables will also cause changes in the drive slide. If the change is too large, it will violate the design requirements. Therefore, the following constraints are imposed on the drive slide stroke:

[0093] (13)

[0094] S34: Use a hierarchical genetic algorithm to iteratively optimize and solve multiple optimization objectives.

[0095] Taking the design variables as individuals in the population, the values ​​of each design variable constitute the initial population and are divided according to their fitness. It is judged whether the fitness of the individual meets the constraints. If not, selection, crossover or mutation is performed to generate a new generation population, and the fitness calculation is performed again. If it is satisfied, it is judged whether the force increase ratio optimization goal is met. If not, selection, crossover or mutation is performed to generate the second generation population, and the fitness calculation is performed again. If it is satisfied, it is judged whether the speed optimization goal is met. If not, selection, crossover or mutation is performed to generate the third generation population, and the fitness calculation is performed again. If it is satisfied, it is judged whether the acceleration optimization goal is met. If not, selection, crossover or mutation is performed to generate the fourth generation population, and the fitness calculation is performed again. If it is satisfied, the global optimal solution of multi-objective optimization is obtained, that is, the optimal rod length combination, so that the optimal rod length combination simultaneously meets the constraints and the optimization goals of maximizing the force increase ratio at the nominal force generation point, minimizing the speed at the nominal force generation point, and minimizing the acceleration at the nominal force generation point, thereby completing the multi-objective optimization of the main transmission mechanism of the press.

[0096] The changes in rod lengths before and after optimization are shown in Table 2. The obtained rod length combination is imported into the rigid-flexible coupling model to simulate the kinematics and dynamics of the optimized main transmission mechanism. The obtained kinematic comparison analysis curve and force ratio curve are shown in Table 2. Figures 7-10 shown.

[0097] Table 2: Changes in rod length before and after optimization

[0098]

[0099] After multi-objective optimization of the press's main transmission mechanism, the force multiplication ratio at the nominal force generation point increased by 5.1%, the absolute value of the velocity at the nominal force generation point decreased by 14.7%, and the acceleration at the nominal force generation point decreased by 21.7%. The optimization results met the optimization constraints and the requirements of the objective function, resulting in superior performance of the press's main transmission mechanism.

[0100] In this embodiment, the triangular toggle mechanism, modeled after biological skeletal joints, employs a variable-thickness hollow structure with ball joints at both ends to optimize stiffness distribution and achieve lightweighting. The highly sensitive rods L1, L2, and L5 are designed with a gradually varying thickness as the load is applied to increase structural stiffness and ensure smooth force transmission under heavy loads. Weak joints in the press's main transmission mechanism are locally strengthened through surface coating and induction hardening to prevent damage at these joints due to excessive localized stress.

[0101] Compared with the prior art, the optimization design method of the servo-driven main transmission mechanism of a large-tonnage press provided by the present invention adopts a multi-link-triangular elbow-bar composite force-amplifying mechanism driven by multiple groups of servo motors, so that the designed servo-driven press has the characteristics of large tonnage, effectively increases the table surface of the servo-driven press, and is suitable for the production and manufacturing of super-large components or multiple parts with one mold; in addition, it also has the advantages of fast feeding, slow forming, fast return, and smooth operation. In addition, the symmetrical triangular elbow-bar mechanism imitates the biological bone joints and adopts a variable thickness hollow structure to optimize the stiffness distribution to achieve lightweight weight reduction. The dynamic simulation of the main transmission mechanism is improved by using a rigid-flexible coupling method, and the elastic deformation of the components is taken into account, making the results more reliable. At the same time, a hierarchical genetic algorithm combining a hierarchical sequence method and a genetic algorithm is used to solve the optimization model, which solves the problems of the traditional genetic algorithm being difficult to converge, having poor local search capabilities, and having low optimization accuracy, and obtains a global optimal solution that meets the conditions.

[0102] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, such as a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0103] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for optimizing the main transmission device of a large-tonnage servo press, characterized in that: include: S1: Establish a parametric model of the transmission mechanism of a large-tonnage servo press based on its geometric structure; S2: performing flexibility processing on the rods in the parametric model of the press transmission mechanism, performing stiffness processing on the pressure output slider and the driving slider, and then optimizing the parametric model of the press transmission mechanism to obtain a rigid-flexible coupling model of the press transmission mechanism; S3: The lengths of the upper connecting rod, the triangular elbow link, and the lower connecting rod are used as design variables, and multiple optimization objectives are constructed. The design variables are used as individuals in a population, and a hierarchical genetic algorithm is used to iteratively optimize the multiple optimization objectives in sequence to obtain an optimal rod length combination. The optimal rod length combination is input into the rigid-flexible coupling model of the press transmission mechanism for simulation analysis to achieve optimization of the main transmission device of the large-tonnage servo press; The large-tonnage servo press transmission device comprises a pressure output slider (100) and at least two sets of composite force amplification mechanisms (200) connected to the pressure output slider (100), wherein: Each group of the composite force-amplifying mechanism (200) comprises a driving slider (210), an upper connecting rod (220), a triangular elbow rod (230), and a lower connecting rod (240), wherein one end of the upper connecting rod (220) is hinged to the driving slider (210), and the other end is hinged to the first corner end of the triangular elbow rod (230); one end of the lower connecting rod (240) is hinged to the second corner end of the triangular elbow rod (230), and the other end is hinged to the pressure output slider (100); the third corner end of the triangular elbow rod (230) is hinged to a fixing device; and the driving slider (210) is connected to a servo motor (300) so as to slide under the drive of the servo motor (300).

2. The optimization method for the main transmission device of a large-tonnage servo press according to claim 1, characterized in that: The triangular elbow link (230) is composed of three connecting rods hinged to each other.

3. The optimization method for the main transmission device of a large-tonnage servo press according to claim 2, characterized in that: At least one of the triangular elbow rod (230), the upper connecting rod (220), and the lower connecting rod (240) is a hollow structure whose thickness is proportional to the load-bearing capacity.

4. The optimization method of the main transmission device of a large-tonnage servo press according to claim 1 is characterized in that: There are two groups of compound force amplifying mechanisms (200), and the two groups of compound force amplifying mechanisms (200) are symmetrically arranged at the upper end of the pressure output slider (100).

5. The optimization method for the main transmission device of a large-tonnage servo press according to claim 1 or 4, characterized in that: The third triangular end of the triangular elbow (230) is fixed inside the area formed by the pressure output slider (100) and the driving slider (210).

6. The optimization method for the main transmission device of a large-tonnage servo press according to claim 1, characterized in that: The invention also includes a gear mechanism (400) and a ball screw mechanism (500) provided on the gear mechanism, wherein the driving slider (210) is connected to the ball screw mechanism (500), and the servo motor (300) drives the gear mechanism (400) to rotate, and then the ball screw mechanism (500) on the gear mechanism (400) drives the driving slider (210) to slide in the horizontal direction.

7. The optimization method of the main transmission device of a large-tonnage servo press according to claim 1, characterized in that: Step S3 also includes obtaining the sensitivity of each design variable to each optimization objective, and treating the design variables with a sensitivity less than a preset threshold as constants.

8. The method for optimizing the main transmission device of a large-tonnage servo press according to claim 1, characterized in that: The optimization objectives include at least two of the following: maximizing the force multiplication ratio at the nominal force generation point, minimizing the speed at the nominal force generation point, or minimizing the acceleration at the nominal force generation point; and iteratively optimizing the multiple optimization objectives sequentially using a hierarchical genetic algorithm, specifically: Taking the values ​​of each design variable as the initial population, the constraints, maximum force multiplication ratio, minimum speed and minimum acceleration are sequentially screened and iterated. The populations that meet the conditions are retained, and the populations that do not meet the conditions are selected, crossed and mutated using genetic algorithms to generate a new generation of populations, which are screened and iterated again to obtain the global optimal solution of multiple optimization objectives, that is, the optimal rod length combination.

9. The method for optimizing the main transmission device of a large-tonnage servo press according to claim 8, characterized in that: The step S2 of making the rod members flexible is to make the rod members whose elasticity is greater than a preset threshold flexible.

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