A suspension system of a forging manipulator and a stability and lightweight coupling optimization method thereof

Abstract

The present application belongs to the technical field of forging manipulator, and particularly relates to a suspension system of a forging manipulator and a stability and lightweight coupling optimization method thereof, which comprises the following steps: establishing a mapping relationship between input displacement of a buffer cylinder, a leveling cylinder and an inclined cylinder and output displacement of a clamp end; constructing a stability index k; selecting structural parameters of the suspension system as design variables, taking weight of the suspension system and the stability index k as optimization objectives, and taking stress of the suspension system not exceeding allowable stress as a constraint condition; constructing a stability and lightweight coupling optimization model by using a second-order polynomial response surface method, and obtaining optimal design parameter combination by solving; and performing structural optimization on the suspension system of the forging manipulator; by establishing a mapping relationship between input displacement of the buffer cylinder, the leveling cylinder or the inclined cylinder and output displacement of the clamp end, and constructing a stability and lightweight coupling optimization model, the present application realizes collaborative optimization of stability and lightweight of the suspension system.

Description

Technical Field

[0001] This invention belongs to the field of forging manipulator technology, specifically relating to a suspension system for a forging manipulator and its stability and lightweight coupling optimization method. Background Technology

[0002] As forging manipulators develop towards larger size, higher precision, and higher stability, existing research on suspension systems still has certain limitations: On the one hand, most studies focus on kinematic, dynamic, or control performance analysis, paying insufficient attention to the intrinsic coupling relationship between the structural weight of the suspension system and its motion stability. Lightweight design often takes structural strength or stiffness as a single objective, lacking a systematic assessment of its impact on stability. On the other hand, under buffer conditions, the correlation between the hydraulic cylinder input displacement and the clamp end output response has not been fully described, making it difficult to provide effective evaluation indicators for stability. Summary of the Invention

[0003] The purpose of this invention is to provide a suspension system for a forging manipulator and a method for optimizing its stability and lightweight design. Starting from the actual working conditions of the suspension system, this invention comprehensively considers the structural geometric parameters, stress characteristics, and multi-motion synergy mechanism of the suspension system. It establishes a mapping relationship between the input displacement of the buffer cylinder, lifting cylinder, or tilting cylinder and the output displacement of the clamp end, and constructs a stability and lightweight coupling optimization model to achieve synergistic optimization of the suspension system's stability and lightweight design.

[0004] The technical solution of this invention is: a method for optimizing the coupling of stability and lightweight design of the suspension system of a forging manipulator, comprising the following steps:

[0005] S1. Establish a kinematic model of the suspension system based on its structure. The suspension system includes a front lateral pivot, a rear lateral pivot, a lifting rod, and a clamp. Analyze the horizontal lifting motion, buffering motion, and tilting motion of the clamp in the suspension system, and establish the mapping relationship between the input displacement of the horizontal lifting cylinder, the buffering cylinder, and the tilting cylinder and the output displacement of the clamp end.

[0006] S2. Based on the buffered motion condition, a stability index k is constructed. The stability index k is defined as the ratio of the change in displacement at the end of the clamp to the change in the input displacement of the buffer cylinder under the buffered motion condition. The stability index k satisfies:

[0007] ;

[0008] in, This represents the change in displacement of the clamp tip in the buffer direction. The input displacement change is used to buffer the hydraulic cylinder;

[0009] S3. Select the structural parameters of the suspension system as design variables, take the weight and stability index k of the suspension system as optimization objectives, and take the stress of the suspension system not exceeding the allowable stress as a constraint condition.

[0010] S4. Based on the optimization objective and constraints, determine the range of variation for the design variables;

[0011] S5. Based on the relationship between the design variables, optimization objectives and constraints, a stability and lightweight coupled optimization model is constructed using the second-order polynomial response surface method, and the optimal combination of design parameters that satisfies the stress constraint conditions is obtained by solving the stability and lightweight coupled optimization model.

[0012] S6. Optimize the suspension system of the forging manipulator according to the optimal design parameter combination to reduce the weight of the suspension system and improve the motion stability of the suspension system under buffer motion conditions.

[0013] Preferably, in step S1, a planar coordinate system of the suspension system is established, and the closed vector equations of the lifting cylinder, buffer cylinder and tilting cylinder are established according to the closed vectors. The kinematic mapping relationship between the input displacement of the lifting cylinder, buffer cylinder and tilting cylinder and the output displacement of the clamp end is established respectively.

[0014] Preferably, in step S3, the lifting boom is divided into a first variable boom and a second variable boom. The first variable boom is the boom segment between the connection point of the lifting boom and the front shift shaft and the connection point of the lifting boom and the buffer cylinder; the second variable boom is the boom segment between the connection point of the lifting boom and the front shift shaft and the connection point of the lifting boom and the clamp.

[0015] Preferably, in step S3, the design variables include the length of the first variable rod, the length of the second variable rod, the diameter of the front shift shaft, and the diameter of the rear shift shaft; the lengths of the first and second variable rods are used to adjust the motion stability of the suspension system under buffer motion conditions, and the diameters of the front and rear shift shafts are used to adjust the weight and stress distribution of the suspension system.

[0016] Preferably, in step S5, the second-order polynomial response surface method is to use experimental design method to obtain sample data between the design variables and the stress, weight and stability index k of the suspension system, and to fit the sample data to obtain the stress response model between the design variables and the suspension system stress, the weight response model between the design variables and the suspension system weight, and the stability response model between the design variables and the stability index k.

[0017] The stress response model between the design variables and the suspension system stress is as follows:

[0018] ;

[0019] In the formula: These are the stress values ​​for the suspension system; a1, a2, a3, a4, a5, a6, a7, a8, a9, a 10 a 11 a 12 a 13 a 14 a 15 All are coefficients of a second-order polynomial; l EJ The length of the first variable rod; l EN The length of the second variable rod; The diameter of the front rotating shaft. The diameter of the rear-side rotating shaft;

[0020] The weight response model between the design variables and the weight of the suspension system is as follows:

[0021] ;

[0022] In the formula, Y2 is the weight of the suspension system; b1, b2, b3, b4, b5, and b6 are all coefficients of a second-order polynomial; d C d is the diameter of the front rotating shaft; D The diameter of the rear-side rotating shaft;

[0023] The stability response model between the design variable and the stability index k is as follows:

[0024] ;

[0025] In the formula, Y3 is the stability index k of the suspension system; c1, c2, c3, c4, c5, and c6 are all coefficients of a second-order polynomial; l EJ The length of the first variable rod; l EN The length of the second variable rod.

[0026] Preferably, by performing finite element simulation analysis on the suspension system, stress values ​​under different combinations of design variables are obtained, and these values, along with the weight value and stability index k, are used to construct the stability and lightweight coupled optimization model. The stability and lightweight coupled optimization model is as follows:

[0027] ;

[0028] In the formula: This represents the minimum weight of the suspension system. Let k be the minimum value of the stability index k of the suspension system. The length of the first variable rod, The length of the second variable rod, The diameter of the front rotating shaft. Y1 is the diameter of the rear-side pivot shaft; Y1 is the stress value of the suspension system as a constraint condition; and σ is the allowable stress value of the suspension system. , , , To design the lower limit value of the variable, This is the lower limit of the length of the second variable rod. This is the lower limit of the length of the first variable rod. This is the lower limit of the diameter of the front-side shift shaft. This is the lower limit of the diameter of the rear-side shift shaft; , , , To design the upper limit value of variables, This is the upper limit of the length of the second variable rod. This is the upper limit of the length of the first variable rod. This is the upper limit of the diameter of the front-side pivot shaft. This is the upper limit of the diameter of the rear-side shift shaft.

[0029] This invention also provides a suspension system for a forging manipulator. The suspension system adopts a parallel linkage suspension structure and is positioned between two wall plates of the forging manipulator. A first connecting rod is connected to the middle of the two wall plates, and a second connecting rod is connected to the bottom of the two wall plates. The suspension system includes a front bracket and a rear bracket, which are connected by a support member. The front bracket and the rear bracket are respectively mounted on the wall plates of the forging manipulator via front bracket pins and rear bracket pins. A front lateral movement component is provided on one side of the front bracket. The front lateral movement component includes, but is not limited to, a front lateral movement pivot. A lifting rod is rotatably connected to the front lateral movement pivot, and a clamp support block is connected to the lifting rod. The clamp support block is rotatably connected to the bottom of the lifting boom, and a horizontally set clamp is connected to the clamp support block; a buffer cylinder is rotatably connected to the lifting boom, and a horizontal buffer rod is rotatably connected to one end of the buffer cylinder, which is installed on the first connecting rod; a leveling cylinder is rotatably connected to the bottom of the front bracket, the leveling cylinder is tilted, and one end of the leveling cylinder is rotatably connected to the second connecting rod; a rear side shifting component is connected to one side of the rear bracket, the rear side shifting component including but not limited to a rear side shifting shaft, the rear side shifting shaft is connected to a tilting cylinder through a rotating bracket, the tilting cylinder is located between the rear bracket and the front bracket, and a connector is rotatably connected to the bottom of the tilting cylinder, the connector being connected to the end of the clamp;

[0030] When the suspension system is in a horizontal lifting motion, the horizontal lifting cylinder extends or retracts, pushing the front bracket to rotate around its pivot pin. The front bracket then drives the lifting boom to move up and down via the front transfer shaft. The front bracket, through the support component, drives the rear bracket to rotate around its pivot pin. The rear bracket, through the rear transfer shaft, drives the tilting cylinder, which neither extends nor retracts. The tilting cylinder drives the connecting component at its bottom to move up and down. Both the connecting component and the lifting boom move up and down, causing the clamps to perform a horizontal lifting motion. Simultaneously, as the lifting boom moves up and down, it drives the buffer cylinder to rotate and extend or retract. The overall trajectory of the clamps' horizontal lifting motion is a vertical movement.

[0031] When the suspension system is in the buffering motion condition, the buffer cylinder extends or retracts, and the buffer cylinder pushes the lifting rod to rotate around the front shifting shaft. The leveling cylinder does not operate, and the lifting rod directly drives the clamp to perform the buffering motion. While the lifting rod rotates and drives the clamp to move, the end of the clamp drives the connecting piece to move. The connecting piece drives the tilting cylinder to rotate around the rear shifting shaft. The tilting cylinder does not extend or retract, and the overall movement trajectory of the clamp's buffering motion is horizontal.

[0032] When the suspension system is in a tilting motion, the tilting cylinder extends or retracts, pushing the connecting part to rotate. The end of the connecting part connected to the tilting cylinder moves down or up, and the end of the connecting part connected to the clamp rotates up or down, causing the clamp support block outside the clamp to rotate around its connection with the lifting rod. The clamp then tilts, while the leveling cylinder and buffer cylinder do not operate. The overall trajectory of the clamp's tilting motion is the up-and-down swing of one end of the clamp.

[0033] The beneficial effects of this invention are as follows: By using the stability index k, a quantitative mapping between the input displacement of the lifting cylinder, buffer cylinder, or tilting cylinder and the output displacement of the clamp end is established; by selecting the structural parameters of the suspension system as design variables, and taking the suspension system weight and stability index k as response targets, combined with stress constraint conditions, a coupled optimization model of stability and lightweighting is established. Using this model, multi-factor analysis and fitting are performed, thereby achieving a significant reduction in the weight of the suspension system and a simultaneous improvement in stability while meeting strength requirements. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a simplified structural diagram of the suspension system of the present invention;

[0036] Figure 2 This is a schematic diagram of the kinematic model of the suspension system of the present invention;

[0037] Figure 3 This is a schematic diagram of the suspension system of the present invention from another angle;

[0038] Figure 4 This is a schematic diagram of the forging manipulator of the present invention;

[0039] Figure 5 This is a schematic diagram of the installation state of the suspension system of the present invention.

[0040] In the diagram: front bracket 1, front bracket pin 11, front side shifting shaft 12; rear bracket 2, rear bracket pin 21, rear side shifting shaft 22, rotating bracket 23; lifting rod 3; buffer cylinder 4, horizontal buffer rod 41; lifting cylinder 5; tilting cylinder 6, connecting piece 61; clamp 7, clamp support block 71; wall panel 8, support piece 81, first connecting rod 82, second connecting rod 83. Detailed Implementation

[0041] The technical solutions of the embodiments 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] like Figure 1-5As shown, a suspension system for a forging manipulator is disclosed. The suspension system adopts a parallel linkage suspension structure and is located between two wall plates 8 of the forging manipulator. A first connecting rod 82 is connected to the middle of the two wall plates 8, and a second connecting rod 83 is connected to the bottom of the two wall plates 8. The suspension system includes a front bracket 1 and a rear bracket 2, which are connected by a support member 81. The front bracket 1 and the rear bracket 2 are respectively mounted on the wall plates 8 of the forging manipulator via a front bracket pin 11 and a rear bracket pin 21. A front side shifting component is provided on one side of the front bracket 1. The front side shifting component includes, but is not limited to, a front side shifting pivot 12. A lifting rod 3 is rotatably connected to the front side shifting pivot 12, and a clamp support block 71 is connected to the lifting rod 3. The clamp support block 71 and the... The bottom of the lifting boom 3 is rotatably connected to a clamp 7 horizontally mounted on the clamp support block 71; a buffer cylinder 4 is rotatably connected to the lifting boom 3, and a horizontal buffer rod 41 is rotatably connected to one end of the buffer cylinder 4, which is mounted on the first connecting rod 82; a leveling cylinder 5 is rotatably connected to the bottom of the front bracket 1, which is inclined and one end is rotatably connected to the second connecting rod 83; a rear side shifting component is connected to one side of the rear bracket 2, which includes, but is not limited to, a rear side shifting shaft 22, and a tilting cylinder 6 is rotatably connected to the rear bracket 2 and the front bracket 1 via a rotating bracket 23. The tilting cylinder 6 is located between the rear bracket 2 and the front bracket 1, and a connector 61 is rotatably connected to the bottom of the tilting cylinder 6, which is connected to the end of the clamp 7.

[0044] Specifically in this embodiment, such as Figure 1As shown, point A is the rear bracket pin 21, point B is the front bracket pin 11, point C is the connection point between the support member 81 and the rear bracket 2, point D is the connection point between the support member 81 and the front bracket 1, point E is the connection point between the front side shifting shaft 12 and the lifting rod 3, point N is the connection point between the lifting rod 3 and the clamp support block 71, point J is the connection point between the lifting rod 3 and the buffer cylinder 4, point K is the connection point between the buffer cylinder 4 and the horizontal buffer rod 41, point I is the connection point between the front bracket 1 and the leveling cylinder 5, point L is the connection point between the leveling cylinder 5 and the second connecting rod 83, point H is the connection point between the rear side shifting shaft 22 and the rotating bracket 23, and point M is the connection point between the tilting cylinder 6 and the connecting member 61. It should be noted that the bottom end of the lifting rod 3 is connected to the clamp support... Block 71 is rotatably connected, and clamp 7 is located inside clamp support block 71. That is, with point N as the position of the end of clamp 7, the connection point between connector 61 and clamp 7 is also at point N. The clamp 7 holds the forging and moves it. The movement trajectory of clamp 7 and the forging it holds is the same during the movement of the suspension system. In addition, the tilting cylinder 6 is connected to the rear shift shaft 22 through the rotating bracket 23, and the clamp 7 is connected to the lifting rod 3 through clamp support block 71. In the process of force analysis of the suspension system in this embodiment, the rotating bracket 23 and the tilting cylinder 6 are regarded as a whole. That is, point H can also represent the connection point between the rear shift shaft 22 and the tilting cylinder 6. At the same time, clamp 7 and clamp support block 71 are regarded as a whole. That is, point N can also represent the connection point between the lifting rod 3 and the end of clamp 7.

[0045] To more intuitively illustrate the motion principle of this embodiment, vector KJ represents the buffer cylinder 4, vector IL represents the lifting cylinder 5, vector HM represents the tilting cylinder 6, and vector MN represents the connecting piece 61. The lifting rod 3 is divided into a first variable rod and a second variable rod. The upper part of the lifting rod 3 is taken as the first variable rod. The first variable rod is the segment between the connection point E between the lifting rod 3 and the front shift shaft 12 and the connection point J between the lifting rod 3 and the buffer cylinder 4. Figure 1 The vector EJ in the figure represents the first variable rod; the second variable rod is the rod segment between point E, the connection point between the lifting boom 3 and the front shift shaft 12, and point N, the connection point between the lifting boom 3 and the end of the clamp 7, i.e., using... Figure 1 The vector EN in the vector represents the second variable rod.

[0046] Based on the above embodiments, when the suspension system is in a horizontal lifting motion, the horizontal lifting cylinder 5 extends or retracts, pushing the front bracket 1 to rotate around the front bracket pin 11. The front bracket 1 drives the lifting rod 3 to move up and down via the front transfer shaft 12. The front bracket 1 drives the rear bracket 2 to rotate around the rear bracket pin 21 via the support member 81. The rear bracket 2 drives the tilting cylinder 6 to move up and down via the rear transfer shaft 22. The tilting cylinder 6 does not extend or retract, but drives the connecting member 61 at its bottom to move up and down. Both the connecting member 61 and the lifting rod 3 move up and down. The lifting rod 3 and the connecting member 61 drive the clamp 7 to perform a horizontal lifting motion. While the lifting rod 3 moves up and down, it drives the buffer cylinder 4 to rotate and extend or retract. The overall trajectory of the clamp 7's horizontal lifting motion is a vertical movement. Figure 1 As shown, the length of vector LI changes, causing the front bracket 1 to rotate around point B, which in turn causes vector EN to move, thereby causing point N, representing the end of clamp 7, to move.

[0047] When the suspension system is in a buffering motion condition, the buffer cylinder 4 extends or retracts, pushing the lifting rod 3 to rotate around the front shift shaft 12. The leveling cylinder 5 does not operate, and the lifting rod 3 directly drives the clamp 7 to perform buffering motion. Simultaneously, as the lifting rod 3 rotates and moves the clamp 7, the end of the clamp 7 moves the connecting piece 61, which in turn moves the tilting cylinder 6 around the rear shift shaft 22. The tilting cylinder 6 neither extends nor retracts, and the overall trajectory of the clamp 7's buffering motion is horizontal. Figure 1 As shown, the length of vector KJ changes, causing vector EN, representing the lifting boom 3, to rotate around point E, thereby causing point N, representing the end of the clamp, to move.

[0048] When the suspension system is in a tilting motion condition, the tilting cylinder 6 extends or retracts, pushing the connecting piece 61 to rotate. The end of the connecting piece 61 connected to the tilting cylinder 6 moves down or up, and the end of the connecting piece 61 connected to the clamp 7 rotates up or down, causing the clamp support block 71 outside the clamp 7 to rotate around its connection with the lifting rod 3. The clamp 7 then tilts, while the leveling cylinder 5 and the buffer cylinder 4 do not operate. The overall trajectory of the clamp 7's tilting motion is the up-and-down swing of one end of the clamp 7. Figure 1 As shown, the length of vector HM changes, causing vector MN, representing connector 61, to rotate around point N, while point N, representing the end of clamp 7, does not move.

[0049] In this embodiment, a method for optimizing the coupling of stability and lightweight design of a forging manipulator's suspension system includes the following steps:

[0050] S1. Establish a kinematic model of the forging manipulator suspension system, analyze the lifting, buffering, and tilting motions of the suspension system, and establish the mapping relationship between the input displacement of the lifting cylinder 5, buffer cylinder 4, or tilting cylinder 6 and the output displacement of the clamp 7. Specifically, in this embodiment, the kinematic model of the forging manipulator suspension system is a three-dimensional model established in simulation software, such as... Figure 2 As shown.

[0051] Specifically, in step S1, a plane coordinate system of the suspension system is established, and the closed vector equations of the lifting cylinder 5, the buffer cylinder 4, and the tilting cylinder 6 are established based on the closed vectors. The kinematic mapping relationship between the input displacement of the lifting cylinder 5, the buffer cylinder 4, and the tilting cylinder 6 and the output displacement of the clamp 7 is established respectively.

[0052] When the suspension system is in a horizontal lifting motion, the horizontal lifting cylinder 5 inputs displacement, and the clamp 7 clamps the forging to achieve lifting motion. At the same time, the end of the clamp 7 displaces in the horizontal lifting direction. The displacement of the end of clamp 7 in the horizontal lifting direction has changed. The displacement of the connection point E between the front transfer shaft 12 and the lifting rod 3 is consistent and can be expressed as:

[0053] (Formula 1)

[0054] In the formula, l BE The length of vector BE; for Figure 1 The angle corresponding to the mid-vector BE is the swing angle of the front bracket 1 when the front bracket 1 is in a horizontal lifting motion.

[0055] When the suspension system is in a buffered motion state, clamp 7 holds the forging and achieves horizontal movement, and the displacement of the end of clamp 7 in the buffer direction... The change occurs, the buffer cylinder 4 has an input displacement, which in turn pushes the lifting boom 3 to rotate around point E, the connection point between it and the front transfer shaft 12, and the displacement of the end of the clamp 7 in the buffer direction. The displacement of point J, the connection point between lifting boom 3 and buffer cylinder 4, is consistent with the following:

[0056] (Formula 2)

[0057] In the formula, l EN This is the length of vector EN, which is the length of the second variable rod; for Figure 1 The angle corresponding to the middle vector EN is the swing angle of the second variable rod when the front bracket 1 is in a buffered motion.

[0058] When the suspension system is in a tilting motion, the tilting cylinder 6 inputs displacement, and the clamp holds the forging to achieve pitching motion. At the same time, the end of the clamp 7 displaces in the tilting direction. The change occurs; the displacement of the end of clamp 7 in the tilt direction... The displacement of point N, which is consistent with the connection point between lifting boom 3 and clamp 7, can be expressed as follows:

[0059] (Formula 3)

[0060] In the formula, The swing angle of the end of clamp 7 when the suspension system is in a tilted motion state; it should be noted that this is due to the displacement of the end of clamp 7 in the tilt direction. Swing angle at the end of clamp 7 Equal, in Figure 1 Swing angle at the end of the middle clamp 7 Displacement of the end of clamp 7 in the tilt direction Represented by the same arc.

[0061] like Figure 1 As shown in the figure, θ1 is the argument of vector BE; θ2 is the argument of vector BI; θ3 is the argument of vector EN; θ4 is the argument of vector KJ; θ5 is the argument of vector AH; θ6 is the argument of vector HM; θ7 is the argument of vector KB; θ8 is the argument of vector LI; θ9 is the argument of vector LB. 10 Let θ be the argument of vector MN. 11 Let AB be the argument corresponding to vector AB. In this embodiment, a rectangular coordinate system is established with point B as the origin, the horizontal direction to the right as the X-axis, and the vertical direction upward as the Y-axis. The initial lengths of the lifting cylinder 5, the buffer cylinder 4, and the tilting cylinder 6 are respectively represented as q. 10 q 20 q 30 Meanwhile, the changes in input displacement of the lifting cylinder 5, the buffer cylinder 4, and the tilting cylinder 6 are represented as q1, q2, and q3, respectively. The vectors and phase angles of the suspension system are recorded as shown in Table 1.

[0062]

[0063] In this embodiment, by analyzing the horizontal lifting motion, the buffering motion, and the tilting motion respectively, it is determined that the suspension system is a coupled motion in the horizontal lifting motion state and a decoupled motion in the buffering motion state and the tilting motion state. Based on the motion relationship in the buffering motion state, a stability index k is established.

[0064] Specifically, based on the closed vector, a motion coupling analysis is performed on the suspension system, where:

[0065] Analyzing the lifting motion of the suspension system, the closed vector equation of the lifting cylinder 5 can be obtained in the closed vector LBI as follows:

[0066] (Formula 4)

[0067] Analyzing the damping motion of the suspension system, the closed vector equation for the damping cylinder 4 can be obtained in the closed vector KBEJ as follows:

[0068] (Formula 5)

[0069] Analyzing the tilting motion of the suspension system, the closed vector equation for tilting cylinder 6 can be obtained in the closed vector ABENMH as follows:

[0070] (Formula 6)

[0071] Represent the three vector equations above using complex vector equations:

[0072] (Formula 7)

[0073] (Formula 8)

[0074] (Formula 9)

[0075] In the formula, i is the imaginary unit; e is the natural constant; l LB θ9 is the length of vector LB, and θ9 is the argument of vector LB; BI θ2 is the length of vector BI, θ8 is the argument of vector BI, and θ9 is the argument of vector LI. KB θ7 is the length of vector KB, and θ7 is the argument of vector KB; BE Let θ1 be the length of vector BE, and θ1 be the argument of vector BE; JE The length of vector JE; l AH θ5 is the length of vector AH, θ6 is the argument of vector AH, and θ7 is the argument of vector HM. MN Let θ be the length of vector MN. 10 l is the argument corresponding to vector MN; AB Let θ be the length of vector AB. 11 l is the argument corresponding to vector AB; EN Let θ be the length of vector EN, and θ3 be the argument of vector EN. Vector JE and vector EN are on the same straight line, and θ3 can also be the argument of vector JE.

[0076] Euler's formula Substituting the above three formulas into the analysis, we obtain the following formula:

[0077] (Formula 10)

[0078] In the formula, l KB θ7 is the length of vector KB; θ7 is the argument of vector KB; l BE θ1 is the length of vector BE; θ2 is the argument of vector BE; q2 is the change in input displacement of buffer cylinder 4; q 20 θ4 is the initial length of the buffer cylinder 4; θ4 is the argument of vector KJ; l JE θ is the length of vector JE; θ3 is the argument of vector JE.

[0079] Simplifying the three complex vector equations (Formulas 7, 8, and 9) yields the following formulas for the input displacement changes of the lifting cylinder 5, the buffer cylinder 4, and the tilting cylinder 6:

[0080] (Formula 11)

[0081] (Formula 12)

[0082] (Formula 13)

[0083] In the formula, q1 is the change in input displacement of the lifting cylinder 5; l LB θ9 is the length of vector LB; θ9 is the argument of vector LB; l BI θ2 is the length of vector BI; θ2 is the argument of vector BI; q 10 q1 represents the initial length of the lifting cylinder 5; q2 represents the input displacement change of the buffer cylinder 4; l KB θ7 is the length of vector KB; θ7 is the argument of vector KB; l BE θ1 is the length of vector BE; θ1 is the argument of vector BE; l JE θ is the length of vector JE; θ3 is the argument of vector EN. In this embodiment, vector JE and vector EN are on the same straight line, and θ3 can also be used as the argument of vector JE; q 20 q3 is the initial length of the buffer cylinder 4; q3 is the input displacement change of the tilting cylinder 6; l AB θ is the length of vector AB; 11 l is the argument corresponding to vector AB; EN The length of vector EN; l AH θ5 is the length of vector AH; θ5 is the argument of vector AH; l MN θ is the length of vector MN; 10 q is the argument corresponding to vector MN;30 This is the initial length of the tilting cylinder 6.

[0084] When the suspension system is in a horizontal lifting motion, the displacement of the end of clamp 7 in the horizontal lifting direction is T. a At this time, the forging held by the end of the clamp 7 remains horizontal, that is, the argument angle θ3 corresponding to the vector EN and the argument angle θ7 corresponding to the vector KB are constant, and the tilting cylinder 6 does not input displacement, so the change in input displacement q3 of the tilting cylinder 6 is 0.

[0085] exist Figure 1 From this, we can obtain the known relation: From the above formula, we can obtain:

[0086] (Formula 14) It should be noted that Formula 14 is derived based on the suspension system being in a state of horizontal lifting motion; Substituting into formula 11, with The change in input displacement of the lifting cylinder 5 is the independent variable. The change in input displacement of the buffer cylinder 4 Taking [the variable] as the dependent variable, and simplifying Formula 11 and Formula 12, we obtain Formula 14; specifically: In Formula 11, the length of vector LB, the length of vector BI, and the initial length of the lifting cylinder 5 are... All are known and unchanging, and the argument of vector LB is also known. It is also fixed and unchanging; therefore, in formula 14... It is the change in input displacement of the lifting cylinder 5. Argument corresponding to vector BE Functional dependency relationship between them; In Formula 12, the lengths of vector KB, BE, and JE, and the initial length of buffer cylinder 4 are... All of these are known and unchanging; at the same time, the forging held by the end of clamp 7 remains horizontal, i.e., the argument corresponding to vector KB. Argument corresponding to vector JE It also remains unchanged; therefore, in formula 14... It is the change in input displacement of the buffer cylinder 4. Argument corresponding to vector BE The functional dependency relationship between them.

[0087] Analysis shows that the displacement of the end of clamp 7 in the horizontal lifting direction The input displacement change q1 of the lifting cylinder 5 and the input displacement change q2 of the buffer cylinder 4 are respectively related to... The derivative relationship is:

[0088] (Formula 15)

[0089] (Formula 16)

[0090] When the suspension system is in a buffered motion state, the displacement change of the end of the clamp 7 in the buffer direction is as follows: At this time, the lifting cylinder 5 and the tilting cylinder 6 neither extend nor shorten, and the change in input displacement of the lifting cylinder 5 and the tilting cylinder 6 is 0. Therefore:

[0091] (Formula 17)

[0092] According to Differentiating formula 17 above, we obtain the following formula:

[0093] (Formula 18)

[0094] When the suspension system is in a tilting motion, the displacement change of the tilting end of the clamp in the tilting direction is as follows: At this time, the buffer cylinder 4 and the lifting cylinder 5 neither extend nor shorten, and the change in input displacement of the buffer cylinder 4 and the lifting cylinder 5 is 0. Therefore:

[0095] (Formula 19)

[0096] According to Differentiating formula 19 above, we obtain the following formula:

[0097] (Formula 20)

[0098] In summary, the relationship between the input displacement of the lifting cylinder 5, the buffer cylinder 4, and the tilting cylinder 6 and the input displacement at the end of the clamp 7 can be obtained as follows:

[0099] (Formula 21)

[0100] Analyzing the above matrix, the first row has two elements, indicating that in the state of horizontal lifting motion, both the horizontal lifting cylinder 5 and the buffer cylinder 4 have displacement changes, which is a coupled motion. The second and third rows each have only one element, indicating that in the states of tilting motion and buffering motion, the suspension system of the forging manipulator is in a decoupled state.

[0101] S2. Based on the working condition of buffered motion, a stability index k is constructed to characterize the displacement amplification effect during the transmission of the input displacement of the buffer cylinder 4 to the end displacement of the clamp 7. The stability index k is defined as the ratio of the change in the end displacement of the clamp 7 to the change in the input displacement of the buffer cylinder 4 under the working condition of buffered motion.

[0102] Specifically, in step S2, the stability index k satisfies:

[0103] (Formula 22)

[0104] in, This represents the displacement change of the end of clamp 7 in the buffer direction. The displacement change is input to the buffer cylinder 4.

[0105] Based on the above implementation, the stability index k and and related, And with l EN Therefore, the stability index k is not an empirical parameter, but is determined by the geometry and mechanical characteristics of the suspension system, especially the length parameter l of the second variable link. EN The input displacement of the buffer cylinder 4 directly affects the amplification of the displacement of the clamp 7 end, thus significantly affecting the stability index k. Especially under the condition of buffering motion, the input displacement of the buffer cylinder 4 is not only used to absorb the forging impact load in the forging manipulator and the inertial force during operation, but its displacement change is also transmitted to the end of the clamp 7, thus affecting the instantaneous displacement response of the clamp 7 end. Therefore, the relationship between the input displacement of the buffer cylinder 4 and the output displacement of the clamp 7 end is an important basis for measuring the motion stability of the suspension system. In summary, the stability index k is constructed as the relationship between the input displacement of the buffer cylinder 4 and the output displacement of the clamp 7 end. The stability index k is not only an evaluation index of the motion stability relationship of the suspension system, but also provides a quantitative basis for the establishment of the subsequent stability and lightweight coupling optimization model.

[0106] Furthermore, from a physical perspective, the stability index k essentially reflects the sensitivity of the suspension system to external disturbances under buffer conditions. When the value of the stability index k is relatively small, it indicates that a small input displacement of the buffer cylinder 4 can effectively absorb the impact load in the forging manipulator, and the displacement change at the end of the clamp 7 is relatively smooth, indicating that the system has good stability. Conversely, if the value of the stability index k is relatively large, it indicates that the buffer cylinder 4 needs a large displacement change to maintain stability, the suspension system is more sensitive to external disturbances, and the stability is relatively poor.

[0107] S3. Select the structural parameters of the suspension system as design variables, take the weight and stability index k of the suspension system as optimization objectives, and take the stress of the suspension system not exceeding the allowable stress as a constraint condition.

[0108] It should be noted that the forging manipulator proposed in this embodiment is a certain model of forging manipulator that clamps 200T bars. The structural parameters of the suspension system of this forging manipulator are shown in Table 2:

[0109]

[0110] In the suspension system used in this embodiment, the diameter of the front transfer shaft 12 is 600mm, the diameter of the rear transfer shaft 22 is 500mm, the weight of the entire suspension system is 260523kg, and the value of the stability index k is 0.7048.

[0111] Specifically, in step S3, the design variables include the length of the first variable rod, the length of the second variable rod, the diameter of the front shift shaft 12, and the diameter of the rear shift shaft 22; the lengths of the first and second variable rods are used to adjust the motion stability of the suspension system under buffering conditions, and the diameters of the front shift shaft 12 and the rear shift shaft 22 are used to adjust the weight and stress distribution of the suspension system; Figure 1 In the vector EJ, the first variable rod is represented, and the length of the first variable rod is the same as the length of the vector EJ. EJ ;by Figure 1 The vector EN in the vector represents the second variable rod, and the length of the second variable rod is the same as the length of the vector EN. EN .

[0112] To link stability with lightweight design, the length l of the first variable rod is... EJ The length l of the second variable rod EN As design variables, and based on actual engineering experience, the front transfer shaft 12 and the rear transfer shaft 22 have a significant impact on the weight of the suspension system. Therefore, the diameters of the front transfer shaft 12 and the rear transfer shaft 22 in the suspension system are used as design variables.

[0113] S4. Based on the optimization objective and constraints, determine the range of variation for the design variables.

[0114] It should be noted that the length l of the first variable rod EJ The range of variation is 1383mm-1998mm, if l EJ When the diameter exceeds 1998mm, it is impossible to guarantee that clamp 7 will be in a horizontal position, and at the same time... ENThe same principle applies to determining the limits; however, when determining the diameters of the front transfer shaft 12 and the rear transfer shaft 22, in order to reasonably determine the range of variation of the design variables, it is first necessary to significantly change one of the independent variables so that the result exceeds the material yield limit in certain situations, thereby finding the boundary conditions and finally clarifying the range of variation of each variable; based on the above, the range of variation of the design variables of the suspension system of the forging manipulator is determined as shown in Table 3:

[0115]

[0116] S5. Based on the relationship between the design variables, optimization objectives and constraints, a stability and lightweight coupled optimization model is constructed using the second-order polynomial response surface method, and the optimal combination of design parameters that satisfies the stress constraint conditions is obtained by solving the stability and lightweight coupled optimization model.

[0117] Specifically, in step S5, the second-order polynomial response surface method uses experimental design to obtain sample data between the design variables and the suspension system stress, weight, and stability index k, and fits the sample data to obtain the stress response model between the design variables and the suspension system stress, the weight response model between the design variables and the suspension system weight, and the stability response model between the design variables and the stability index k.

[0118] Specifically, in this embodiment, the stability response model is essentially a mathematical model that fits the data using approximation methods, constrained by fitting accuracy and prediction accuracy. Mathematically, it can be achieved through fitting and interpolation. In engineering optimization, the relationship between variables and responses is often unknown. Regardless of the relationship between variables and responses, a second-order polynomial can establish a response surface model, thereby fitting analytical expressions for the input displacement of the buffer cylinder 4, the lifting cylinder 5, or the tilting cylinder 6, and the output displacement at the end of the clamp 7. This embodiment uses the second-order polynomial response surface method, taking the length of the first variable rod, the length of the second variable rod, the diameter of the front shift shaft 12, and the diameter of the rear shift shaft 22 as variables x, and the optimization objective and constraints as responses y. The relationship between variables x and responses y is expressed as follows:

[0119] (Formula 23)

[0120] In the formula: The term is the intercept; m is the range of variables. The first-order main effect coefficient; These are the second-order main effect coefficients; The coefficients of the interaction terms; For the error term; x i For any design variable, x j To divide x iAny design variable other than [the one mentioned above].

[0121] First, select the length l of the first variable rod. EJ The length l of the second variable rod EN The diameters of the front and rear transfer shafts 12 and 22 are used as design variables; the minimum weight of the suspension system and the minimum value of the stability index k are used as objective functions, and the allowable stress of the suspension system is used as a constraint condition. In this embodiment, the Box-Behnken experimental design method is used for the experiment. The advantages of this experimental design method are: it can construct a high-order response surface with only a small number of sample points, and it requires fewer experiments, can simultaneously evaluate the influence of multiple factors, and has higher accuracy in the response regression equation. The Box-Behnken experimental design method is used to test 25 sets of data. The set of data with the smallest suspension system weight and stability index k value is selected, and four more experiments are conducted using the design variables of this set of data. The 29 sets of experimental data shown in Table 4 are obtained.

[0122]

[0123] Subsequently, ANSYS Workbench was used to perform transient analysis on the stress, weight, and stability index k values ​​of each set of data to obtain the optimal design parameter combination. In this optimal design parameter combination, the length l of the first variable rod is... EJ The length l of the first variable rod is 1690.5 mm. EN The diameter of the front transfer shaft 12 is 600mm, the diameter of the rear transfer shaft 22 is 500mm, the stress value of the suspension system is 285.48MPa, the weight of the suspension system is 240390kg, and the stability index k of the suspension system is 0.6052. The boundary conditions during the test include applying a pressure of 16MPa to the buffer cylinder 4, the lifting cylinder 5, and the tilting cylinder 6, respectively, applying a fixed support to the bottom surface, and applying a long-range force of 4480000N at 2036.2mm on the x-axis.

[0124] By analyzing the experimental results in Table 4 using response surface methodology software, the length l of the first variable rod can be obtained. EJ The length l of the second variable rod EN The stress response model relating the diameter of the front transfer shaft 12, the diameter of the rear transfer shaft 22, and the stress in the suspension system is as follows:

[0125] (Formula 24)

[0126] In the formula: This refers to the stress value of the suspension system; EJ The length of vector EJ, i.e., the length of the first variable rod; lEN This is the length of vector EN, which is the length of the second variable rod; The diameter of the front rotating shaft 12, The diameter of the rear-side rotating shaft 22.

[0127] In the optimization analysis of the suspension system, the stress magnitude of the suspension system is the result of the combined effect of multiple factors, and the objective function and design variables do not exhibit a linear relationship. Based on the experimental data obtained from the Design-Expert software, the response surface of the input parameters to the output parameters was plotted using the Origin software.

[0128] Analyzing the test results in Table 4, we can also obtain the weight response model between the diameters of the front and rear transfer shafts 12 and the weight of the suspension system:

[0129] (Formula 25)

[0130] In the formula, Y2 is the weight of the suspension system; E, E+005, and E-017 are all in scientific notation, where E represents a power of 10. represent , represent ;d C The diameter of the front transfer shaft 12; d D The diameter of the rear-side rotating shaft 22.

[0131] At the same time, the length l of the first variable rod can also be obtained. EJ The length l of the second variable rod EN Stability response model with stability index k:

[0132] (Formula 26)

[0133] In the formula, Y3 is the suspension system stability index k; E, E-004, E-005, E-007, and E-008 are all scientific notation, where E represents a power of 10. represent , represent , represent , and Represent and ;l EJ The length of vector EJ, i.e., the length of the first variable rod; l EN The length of vector EN is the length of the second variable rod.

[0134] Analysis of variance was performed on the stress response model, weight response model, and stability response model using 29 sets of experimental data. The results show the variance of the stress values ​​in the suspension system: =0.9012; Variance of suspension system weight: =0.999; Variance of suspension system stability index k: =0.9888; , , The values ​​are all close to 1, indicating that the stress response model, weight response model, and stability response model all have good fitting effects and can be used to predict and optimize the structure of the suspension system.

[0135] This embodiment uses finite element simulation analysis of the suspension system to obtain stress values ​​under different combinations of design variables. These stress values, along with weight values ​​and the stability index k, are used to construct a coupled optimization model for stability and lightweighting. Based on the three elements of optimization design—design variables, constraints, and optimization objectives—a coupled optimization model for stability and lightweighting is established.

[0136] (Formula 27)

[0137] In the formula: This represents the minimum weight of the suspension system. Let k be the minimum value of the stability index k of the suspension system. Let the length of the first variable rod be _____. The length of the second variable rod, The diameter of the front rotating shaft 12, Y1 is the diameter of the rear-side transfer shaft 22; Y1 is the stress of the suspension system as a constraint condition; and σ is the allowable stress value of the suspension system. , , , To design the lower limit value of the variable, specifically in this embodiment, This is the lower limit of the length of the second variable rod. This is the lower limit of the length of the first variable rod. This is the lower limit of the diameter of the front-side shift shaft 12. This is the lower limit of the diameter of the rear-side transfer shaft 22; , , , To design an upper limit value for the variable, specifically in this embodiment, This is the upper limit of the length of the second variable rod. This is the upper limit of the length of the first variable rod. This is the upper limit of the diameter of the front-side transfer shaft 12. This is the upper limit of the diameter of the rear-side transfer shaft 22.

[0138] In summary, this embodiment constructs a kinematic model of the suspension system of the forging manipulator, and based on the force analysis of each link in the suspension system, extracts the length l of the first variable link, a key parameter of the suspension system under the buffer condition. EJ The length l of the second variable rod EN The diameters of the front and rear shifting shafts 12 and 22 are determined. Further analysis of the kinematic mapping equations between the input displacement of the buffer cylinder 4, the lifting cylinder 5, or the tilting cylinder 6 and the output displacement at the end of the clamp 7 is conducted. The coupling and decoupling of multiple motions involving the lifting cylinder 5, the tilting cylinder 6, and the buffer cylinder 4 are analyzed, yielding the length l of the first variable rod, a key parameter. EJ The length l of the second variable rod EN The stability of the suspension system under buffered motion conditions is affected, and a stability index k is proposed. A coupled optimization model of stability and lightweighting is established, and the Box-Behnken experimental design method is selected to optimize the key parameters. With the weight of the suspension system and the stability index k as the optimization objectives and stress constraints as the limit, the value of the stability index k of the suspension system after optimization is reduced from 0.7048 to 0.6052, a reduction of 14.1%. The weight of the suspension system after optimization is 240390 kg. Under the stress condition, compared with the suspension system with a weight of 260523 kg used in the simulation test before optimization, the weight of the suspension system is reduced by 7.728%, and the stability is also improved, achieving the dual optimization purpose. It should be noted that the optimization of the suspension system weight in this embodiment mainly focuses on reducing the weight of the front bracket 1, the rear bracket 2, and the lifting rod 3.

[0139] In this embodiment, by analyzing the 29 sets of experimental data in Table 4, a stability and lightweight coupled optimization model is obtained. The stability and lightweight coupled optimization model is used to solve the suspension system with different structural parameters to obtain the optimal combination of design parameters for each suspension system under stress constraint conditions.

[0140] S6. Optimize the suspension system of the forging manipulator according to the optimal design parameter combination to reduce the weight of the suspension system and improve its motion stability under buffered motion conditions.

[0141] Based on the above embodiments, a stability and lightweight coupled optimization model is obtained through steps S1 to S5, and the optimal combination of design parameters, namely the length l of the first variable rod, is derived based on the stability and lightweight coupled optimization model. EJ The length l of the second variable rod EN The four optimal design parameters—the diameter of the front transfer shaft 12 and the diameter of the rear transfer shaft 22—are used to optimize the suspension system of the forging manipulator, thereby reducing the weight of the suspension system.

[0142] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for optimizing the coupling of stability and lightweight design of the suspension system of a forging manipulator, characterized in that, Includes the following steps: S1. Establish a kinematic model of the suspension system based on its structure. The suspension system includes a front lateral pivot, a rear lateral pivot, a lifting rod, and a clamp. Analyze the horizontal lifting motion, buffering motion, and tilting motion of the clamp in the suspension system, and establish the mapping relationship between the input displacement of the horizontal lifting cylinder, the buffering cylinder, and the tilting cylinder and the output displacement of the clamp end. S2. Based on the buffered motion condition, a stability index k is constructed. The stability index k is defined as the ratio of the change in displacement at the end of the clamp to the change in the input displacement of the buffer cylinder under the buffered motion condition. The stability index k satisfies: ； in, This represents the change in displacement of the clamp tip in the buffer direction. The input displacement change is used to buffer the hydraulic cylinder; S3. Select the structural parameters of the suspension system as design variables, take the weight and stability index k of the suspension system as optimization objectives, and take the stress of the suspension system not exceeding the allowable stress as a constraint condition. S4. Based on the optimization objective and constraints, determine the range of variation for the design variables; S5. Based on the relationship between the design variables, optimization objectives and constraints, a stability and lightweight coupled optimization model is constructed using the second-order polynomial response surface method, and the optimal combination of design parameters that satisfies the stress constraint conditions is obtained by solving the stability and lightweight coupled optimization model. S6. Optimize the suspension system of the forging manipulator according to the optimal design parameter combination to reduce the weight of the suspension system and improve the motion stability of the suspension system under buffer motion conditions.

2. The method for optimizing the coupling of stability and lightweight design of the suspension system of a forging manipulator according to claim 1, characterized in that, In step S1, a plane coordinate system of the suspension system is established, and the closed vector equations of the lifting cylinder, buffer cylinder and tilting cylinder are established according to the closed vector. The kinematic mapping relationship between the input displacement of the lifting cylinder, buffer cylinder and tilting cylinder and the output displacement of the clamp end is established respectively.

3. The method for optimizing the coupling of stability and lightweight design of the suspension system of a forging manipulator according to claim 2, characterized in that, In step S3, the lifting boom is divided into a first variable boom and a second variable boom. The first variable boom is the boom segment between the connection point of the lifting boom and the front shift shaft and the connection point of the lifting boom and the buffer cylinder. The second variable boom is the boom segment between the connection point of the lifting boom and the front shift shaft and the connection point of the lifting boom and the clamp.

4. The method for optimizing the coupling of stability and lightweight design of the suspension system of a forging manipulator according to claim 3, characterized in that, In step S3, the design variables include the length of the first variable rod, the length of the second variable rod, the diameter of the front shift shaft, and the diameter of the rear shift shaft. The lengths of the first and second variable rods are used to adjust the motion stability of the suspension system under buffer motion conditions, and the diameters of the front and rear shift shafts are used to adjust the weight and stress distribution of the suspension system.

5. The method for optimizing the coupling of stability and lightweight design of the suspension system of a forging manipulator according to claim 4, characterized in that, In step S5, the second-order polynomial response surface method is to use experimental design method to obtain sample data between design variables and the stress, weight and stability index k of the suspension system, and to fit the sample data to obtain the stress response model between design variables and the stress of the suspension system, the weight response model between design variables and the weight of the suspension system, and the stability response model between design variables and the stability index k. The stress response model between the design variables and the suspension system stress is as follows: ； In the formula: These are the stress values ​​for the suspension system; a1, a2, a3, a4, a5, a6, a7, a8, a9, a 10 a 11 a 12 a 13 a 14 a 15 All are coefficients of a second-order polynomial; l EJ The length of the first variable rod; l EN The length of the second variable rod; The diameter of the front rotating shaft. The diameter of the rear-side rotating shaft; The weight response model between the design variables and the weight of the suspension system is as follows: ； In the formula, Y2 is the weight of the suspension system; b1, b2, b3, b4, b5, and b6 are all coefficients of a second-order polynomial; d C d is the diameter of the front rotating shaft. D The diameter of the rear-side rotating shaft; The stability response model between the design variable and the stability index k is as follows: ； In the formula, Y3 is the stability index k of the suspension system; c1, c2, c3, c4, c5, and c6 are all coefficients of a second-order polynomial; l EJ The length of the first variable rod; l EN The length of the second variable rod.

6. The method for optimizing the coupling of stability and lightweight design of the suspension system of a forging manipulator according to claim 5, characterized in that, By performing finite element simulation analysis on the suspension system, stress values ​​under different combinations of design variables were obtained. These values, along with the weight value and stability index k, were used to construct the stability-lightweight coupled optimization model. The stability-lightweight coupled optimization model is as follows: ； In the formula: This represents the minimum weight of the suspension system. Let k be the minimum value of the stability index k of the suspension system. The length of the first variable rod, The length of the second variable rod, The diameter of the front rotating shaft. Y1 is the diameter of the rear-side pivot shaft; Y1 is the stress value of the suspension system as a constraint condition; σ is the allowable stress value of the suspension system. , , , To design the lower limit value of the variable, This is the lower limit of the length of the second variable rod. This is the lower limit of the length of the first variable rod. This is the lower limit of the diameter of the front-side shift shaft. This is the lower limit of the diameter of the rear-side shift shaft; , , , To design the upper limit value of the variable, This is the upper limit of the length of the second variable rod. This is the upper limit of the length of the first variable rod. This is the upper limit of the diameter of the front-side pivot shaft. This is the upper limit of the diameter of the rear-side shift shaft.

7. A suspension system for a forging manipulator, characterized in that, The method for optimizing the stability and lightweight coupling of the suspension system of a forging manipulator according to any one of claims 1-6 describes a suspension system with a parallel linkage suspension structure. The suspension system is positioned between two wall plates of the forging manipulator, with a first connecting rod connected to the middle of the two wall plates and a second connecting rod connected to the bottom of the two wall plates. The suspension system includes a front bracket and a rear bracket, connected by a support member. The front bracket and rear bracket are respectively mounted on the wall plates of the forging manipulator via front bracket pins and rear bracket pins. A front lateral shifting component is provided on one side of the front bracket, including but not limited to a front lateral shifting shaft. A lifting rod is rotatably connected to the front lateral shifting shaft. A clamp support block is connected to the lifting boom, and the clamp support block is rotatably connected to the bottom of the lifting boom. A horizontally set clamp is connected to the clamp support block. A buffer cylinder is rotatably connected to the lifting boom, and a horizontal buffer rod is rotatably connected to one end of the buffer cylinder. The horizontal buffer rod is installed on the first connecting rod. A leveling cylinder is rotatably connected to the bottom of the front bracket. The leveling cylinder is tilted, and one end of the leveling cylinder is rotatably connected to the second connecting rod. A rear side shifting component is connected to one side of the rear bracket. The rear side shifting component includes, but is not limited to, a rear side shifting pivot. The rear side shifting pivot is connected to a tilting cylinder through a rotating bracket. The tilting cylinder is located between the rear bracket and the front bracket. A connector is rotatably connected to the bottom end of the tilting cylinder. The connector is connected to the end of the clamp. When the suspension system is in a horizontal lifting motion, the horizontal lifting cylinder extends or retracts, pushing the front bracket to rotate around its pivot pin. The front bracket then drives the lifting boom to move up and down via the front transfer shaft. The front bracket, through the support component, drives the rear bracket to rotate around its pivot pin. The rear bracket, through the rear transfer shaft, drives the tilting cylinder, which neither extends nor retracts. The tilting cylinder drives the connecting component at its bottom to move up and down. Both the connecting component and the lifting boom move up and down, causing the clamps to perform a horizontal lifting motion. Simultaneously, as the lifting boom moves up and down, it drives the buffer cylinder to rotate and extend or retract. The overall trajectory of the clamps' horizontal lifting motion is a vertical movement. When the suspension system is in the buffering motion condition, the buffer cylinder extends or retracts, and the buffer cylinder pushes the lifting rod to rotate around the front shifting shaft. The leveling cylinder does not operate, and the lifting rod directly drives the clamp to perform the buffering motion. While the lifting rod rotates and drives the clamp to move, the end of the clamp drives the connecting piece to move. The connecting piece drives the tilting cylinder to rotate around the rear shifting shaft. The tilting cylinder does not extend or retract, and the overall movement trajectory of the clamp's buffering motion is horizontal. When the suspension system is in a tilting motion, the tilting cylinder extends or retracts, pushing the connecting part to rotate. The end of the connecting part connected to the tilting cylinder moves down or up, and the end of the connecting part connected to the clamp rotates up or down, causing the clamp support block outside the clamp to rotate around its connection with the lifting rod. The clamp then tilts, while the leveling cylinder and buffer cylinder do not operate. The overall trajectory of the clamp's tilting motion is the up-and-down swing of one end of the clamp.

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